KR20110043461A - Bar type light emitting device, method of manufacturing the same, backlight, illumination device and display device - Google Patents

Abstract

PURPOSE: A rod-shaped light emitting device, a manufacturing method thereof, a backlight, a lighting device, and a display device are provided to implement high luminous efficiency by including a second conductive type semiconductor layer. CONSTITUTION: A rod-shaped first conductive semiconductor core(11) is provided. A second conductive semiconductor layer(12) covers the rod-shaped first conductive semiconductor core. A part of the outer surface of the semiconductor core is exposed. A cap layer covers the end of the semiconductor core and is made of materials with larger electric resistance than the resistance of the semiconductor layer.

Description

BAR TYPE LIGHT EMITTING DEVICE, METHOD OF MANUFACTURING THE SAME, BACKLIGHT, ILLUMINATION DEVICE AND DISPLAY DEVICE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rod-shaped light emitting device, a method for manufacturing a rod-shaped light emitting device, a backlight, a lighting device, and a display device.

Conventionally, as a light emitting element having a rod-like structure, there is a nano-order size in which a heterostructure is formed of a rod-shaped core portion made of a compound semiconductor and a cylindrical shell portion made of a compound semiconductor surrounding the core portion (for example, Japanese Patent Laid-Open Patent Publication). 2008-235443). In this light emitting element, the core portion itself becomes an active layer, and electrons and holes injected from the outer circumferential surface recombine within the core portion to emit light.

A rod-shaped light emitting device having a core part consisting of an n-type semiconductor and a shell part consisting of a p-type semiconductor using the same manufacturing method as the above light emitting device, wherein electrons and holes recombine and emit light at a pn junction between the outer peripheral surface of the core part and the inner peripheral surface of the shell part. When the device is manufactured, there is a problem that connection between the core part and the electrode is difficult because the core part is exposed only at both end faces.

In addition, as a method of manufacturing a rod-shaped structure light emitting device, after forming a flat first polar layer on the substrate, a plurality of nanoscale rods corresponding to the active layer emitting light on the first polar layer are formed, and further, the rod surrounds the rod. Is to form a second polar layer (see, for example, Japanese Patent Laid-Open No. 2006-332650). This rod-shaped light emitting device emits light from a plurality of rods which are active layers.

However, since the rod-shaped structured light emitting device is used on a substrate provided with a plurality of rods of a nanoscale, there is a problem in that the degree of freedom in mounting to the device is low because it is restricted by the substrate when assembled to a lighting device or a display device.

In addition, the light emitting device having the rod-shaped light emitting device has a problem in that the light extraction efficiency is lowered because most of the light is radiated laterally and absorbed by adjacent rods when a plurality of rods are placed on the substrate. . In addition, in the rod structure light emitting device, since a plurality of rods are placed on a substrate, there is a problem that the heat radiation efficiency is poor.

Japanese Patent Publication No. 2008-235443 Japanese Patent Publication No. 2006-332650

Accordingly, an object of the present invention is to provide a fine rod-shaped light emitting element and a rod-shaped light emitting element having a high luminous efficiency which can be easily connected to electrodes with a simple configuration.

Another object of the present invention is to provide a backlight, a lighting device, and a display device that can be made thinner and lighter, and have high luminous efficiency and power saving by using the rod-shaped light emitting device.

Moreover, the subject of this invention is providing the manufacturing method of the fine rod structure light emitting element with high degree of freedom of mounting to an apparatus, and the manufacturing method of the display apparatus provided with the rod structure light emitting element.

Another object of the present invention is to provide a light emitting device having high light extraction efficiency and good heat dissipation.

Another object of the present invention is to provide a backlight, a lighting device, and a display device having high luminous efficiency and good heat-saving heat dissipation by using the light emitting device.

The rod-shaped structure light emitting device according to the first aspect of the present invention,

A rod-shaped first conductive semiconductor core,

And a second conductive semiconductor layer formed to cover the semiconductor core,

An outer peripheral surface of a part of the semiconductor core is exposed.

According to the above configuration, the second conductive semiconductor layer is formed to cover the rod-shaped first conductive semiconductor core and to expose the outer circumferential surface of a portion of the semiconductor core, thereby forming a fine rod-shaped micro- or nano-order size. Even in the structured light emitting element, the exposed portion of the semiconductor core can be connected to one electrode and the other electrode can be connected to the portion of the semiconductor layer covering the semiconductor core. The rod-shaped structure light emitting device connects one electrode to the exposed portion of the semiconductor core and the other electrode to the semiconductor layer so that recombination of electrons and holes occurs at the pn junction between the outer circumferential surface of the semiconductor core and the inner circumferential surface of the semiconductor layer. The light is emitted from the pn junction by flowing a current between the electrodes. In this rod-shaped structure light emitting device, light is emitted from the entire circumference of the semiconductor core covered with the semiconductor layer, so that the light emitting area is widened, so that the light emitting efficiency is high. Therefore, a fine rod-shaped light emitting device having a high luminous efficiency that can be easily connected to electrodes with a simple configuration can be realized. Since the rod-shaped light emitting element is not integral with the substrate, it has a high degree of freedom in mounting to the device.

Here, the fine rod-shaped light emitting device is, for example, a micro order size having a diameter of 1 μm and a length of 10 μm, or a nano order size having at least a diameter of less than 1 μm in diameter or length. In addition, the rod-shaped structured light emitting device can reduce the amount of semiconductor used, and it is possible to reduce the thickness and weight of the device using the light emitting device, and to realize a high luminous efficiency and power saving backlight, lighting device and display device, and the like. Can be.

In one embodiment, the outer peripheral surface of the one end side of the said semiconductor core is exposed.

In one embodiment, the end surface of the other end side of the said semiconductor core is covered with the said semiconductor layer.

In one embodiment, the thickness of the semiconductor layer is thicker in the axial direction of the portion covering the end surface of the other end side of the semiconductor core than the thickness in the radial direction of the portion covering the outer circumferential surface of the semiconductor core.

In one embodiment, the outer circumferential surface of the exposed region of the semiconductor core substantially coincides with the extended surface of the outermost circumferential surface of the region covered with the semiconductor layer.

In one embodiment, a quantum well layer is formed between the semiconductor core and the semiconductor layer.

In one embodiment,

While the outer peripheral surface of one end side of the semiconductor core is exposed,

An end surface of the other end side of the semiconductor core is covered by the semiconductor layer,

A quantum well layer formed between the semiconductor core and the semiconductor layer,

The quantum well layer is thicker in the axial direction of the portion covering the end surface of the other end side of the semiconductor core than the thickness in the radial direction of the portion covering the outer circumferential surface of the semiconductor core.

In one embodiment, a transparent electrode is formed to cover the semiconductor layer.

In one embodiment,

The semiconductor core is made of an n-type semiconductor,

The semiconductor layer is made of a p-type semiconductor,

The transparent electrode is formed to cover approximately the entirety of the semiconductor layer.

Moreover, in the manufacturing method of the rod-shaped structure light emitting element which concerns on 2nd aspect of this invention,

A catalyst metal layer forming step of forming an island-shaped catalyst metal layer on a first conductive substrate,

A semiconductor for forming a rod-shaped first conductive semiconductor core by crystal-growing a first conductive semiconductor from an interface between the island-shaped catalyst metal layer and the substrate on the substrate on which the island-shaped catalyst metal layer is formed. Core forming process,

A second covering the surface of the semiconductor core by crystal growth from an outer circumferential surface of the semiconductor core and an interface between the island-shaped catalyst metal layer and the semiconductor core while the island-like catalyst metal layer is held at the tip of the semiconductor core A semiconductor layer forming step of forming a conductive semiconductor layer,

An exposure step of exposing an outer circumferential surface of the semiconductor core on the substrate side;

And a separating step of separating the semiconductor core including the exposed portion exposed in the exposing step from the substrate.

Here, the "first conductivity type substrate" may be a substrate made of a first conductivity type semiconductor, or may be one in which a first conductivity type semiconductor film is formed on the surface of the underlying substrate.

According to the above constitution, after the island-shaped catalyst metal layer is formed on the substrate of the first conductivity type, the semiconductor of the first conductivity type is formed from the interface between the island-type catalyst metal layer and the substrate on the substrate on which the island-type catalyst metal layer is formed. By crystal growth, a rod-shaped first conductive semiconductor core is formed. Thereafter, in the state where the island-like catalyst metal layer is held at the tip of the semiconductor core, the second conductivity type covers the surface of the semiconductor core by crystal growth from the outer circumferential surface of the semiconductor core and the interface between the island-shaped catalyst metal layer and the semiconductor core. A semiconductor layer is formed. At this time, since the crystal growth from the interface between the catalyst metal layer and the semiconductor core is promoted more than the outer circumferential surface of the semiconductor core, the axis of the portion covering the end surface of the other end side of the semiconductor core is larger than the thickness in the radial direction of the portion covering the outer circumferential surface of the semiconductor core. The thickness of the direction becomes thicker.

Then, after exposing the substrate-side outer peripheral surface of the semiconductor core, the semiconductor core including the exposed portion is separated from the substrate by vibrating the substrate by, for example, ultrasonic waves or by using a cutting tool. The rod-shaped structure light emitting device separated from the substrate in this way connects one electrode to the exposed portion of the semiconductor core and the other electrode to the semiconductor layer, thereby connecting the electrons at the pn junction between the outer circumferential surface of the semiconductor core and the inner circumferential surface of the semiconductor layer. Light is emitted from the pn junction by flowing a current between the electrodes to cause recombination of the holes.

Crystal growth is promoted by the catalyst metal layer by forming a second conductive semiconductor layer so as to cover the surface of the semiconductor core while the island-like catalyst metal layer is maintained at the tip of the semiconductor core without removing the island-like catalyst metal layer. Therefore, it is possible to easily form a semiconductor layer whose thickness in the axial direction of the portion covering the end surface of the other end side of the semiconductor core is larger than the thickness in the radial direction of the portion covering the outer circumferential surface of the semiconductor core.

In this manner, a fine rod-shaped structure light emitting device having a high degree of freedom in mounting to an apparatus can be manufactured. Here, the fine rod-shaped light emitting device is, for example, a micro order size having a diameter of 1 μm and a length of 10 μm, or a nano order size having at least a diameter of less than 1 μm in diameter or length. In addition, the rod-shaped structured light emitting device can reduce the amount of semiconductor used, and it is possible to reduce the thickness and weight of the device using the light emitting device and to emit light from the entire circumference of the semiconductor core covered with the semiconductor layer. Since the light emitting area is wider, a high luminous efficiency and a power saving backlight, lighting device, display device, and the like can be realized.

Moreover, in the manufacturing method of the rod-shaped structure light emitting element which concerns on 3rd aspect of this invention,

A catalyst metal layer forming step of forming an island-shaped catalyst metal layer on a first conductive substrate,

A semiconductor core forming step of forming a rod-shaped first conductive semiconductor core by crystal-growing a first conductive semiconductor from an interface between the island-shaped catalyst metal layer and the substrate on the substrate on which the island-shaped catalyst metal layer is formed. and,

A quantum well covering the surface of the semiconductor core by crystal growth from an outer circumferential surface of the semiconductor core and an interface between the island-shaped catalyst metal layer and the semiconductor core while the island-like catalyst metal layer is held at the tip of the semiconductor core. A quantum well layer forming process of forming a layer,

A semiconductor layer forming step of forming a second conductive semiconductor layer covering the surface of the quantum well layer;

An exposure step of exposing an outer circumferential surface of the semiconductor core on the substrate side;

And a separating step of separating the semiconductor core including the exposed portion exposed in the exposing step from the substrate.

According to the above constitution, after the island-shaped catalyst metal layer is formed on the substrate of the first conductivity type, the semiconductor of the first conductivity type is formed from the interface between the island-type catalyst metal layer and the substrate on the substrate on which the island-type catalyst metal layer is formed. By crystal growth, a rod-shaped first conductive semiconductor core is formed. Thereafter, the quantum well layer covering the surface of the semiconductor core by crystal growth from the interface between the outer circumferential surface of the semiconductor core and the island-shaped catalyst metal layer and the semiconductor core while the island-like catalyst metal layer is held at the tip of the semiconductor core. Form. At this time, crystal growth from the interface between the catalyst metal layer and the semiconductor core is promoted more than the outer circumferential surface of the semiconductor core, so that the quantum well layer covers the end surface of the other end side of the semiconductor core rather than the thickness of the radial direction of the portion covering the outer circumferential surface of the semiconductor core. The thickness in the axial direction becomes thicker.

Subsequently, a second conductive semiconductor layer covering the surface of the quantum well layer is formed, and the outer peripheral surface of the substrate side of the semiconductor core is exposed. After exposing the substrate-side outer circumferential surface of the semiconductor core, the semiconductor core including the exposed portion is separated from the substrate by vibrating the substrate by, for example, ultrasonic waves or by using a cutting tool. The rod-shaped structure light emitting device separated from the substrate in this way connects one electrode to the exposed portion of the semiconductor core and the other electrode to the semiconductor layer, thereby connecting the electrons at the pn junction between the outer circumferential surface of the semiconductor core and the inner circumferential surface of the semiconductor layer. Light is emitted from the pn junction by flowing a current between the electrodes to cause recombination of the holes.

Crystal growth is promoted by the catalyst metal layer by forming a quantum well layer so as to cover the surface of the semiconductor core while the island-like catalyst metal layer is maintained at the tip of the semiconductor core without removing the island-like catalyst metal layer. A quantum well layer having a larger thickness in the axial direction of the portion covering the end surface on the other end side of the semiconductor core than the thickness in the radial direction of the portion covering the outer circumferential surface can be easily formed.

In this manner, the fine rod-shaped structure light emitting device having a high degree of freedom in mounting to the device can be manufactured by the manufacturing method according to the second and third aspects. Here, the fine rod-shaped light emitting device is, for example, a micro order size having a diameter of 1 μm and a length of 10 μm, or a nano order size having at least a diameter of less than 1 μm in diameter or length. In addition, the rod-shaped structured light emitting device can reduce the amount of semiconductor used, and it is possible to reduce the thickness and weight of the device using the light emitting device and to emit light from the entire circumference of the semiconductor core covered with the semiconductor layer. Since the light emitting area is wider, a high luminous efficiency and a power saving backlight, lighting device, display device, and the like can be realized.

The rod-shaped structure light emitting device according to the fourth aspect of the present invention,

A rod-shaped first conductive semiconductor core,

A cap layer covering one end surface of the semiconductor core,

A second conductive semiconductor layer covering an outer circumferential surface of a portion other than the exposed portion of the semiconductor core so as to be an exposed portion without covering a portion opposite to the portion of the semiconductor core covered with the cap layer,

The cap layer is made of a material having a larger electrical resistance than the semiconductor layer.

According to the said structure, while covering one end surface of the rod-shaped 1st conductivity type semiconductor core with a cap layer, it exposes a semiconductor core so that it may become an exposed part, without covering the part on the opposite side to the part of the semiconductor core covered with the cap layer. By covering the outer circumferential surface of the portions other than the portions with the second conductive semiconductor layer, even when the micro rod size or the nano rod size is a fine rod-shaped structure light emitting device, the exposed portion of the semiconductor core is connected to one electrode to cover the semiconductor core. The other electrode can be connected to the portion of the semiconductor layer. The rod-shaped structure light emitting device reconnects electrons and holes at an interface (pn junction) between an outer peripheral surface of the semiconductor core and an inner peripheral surface of the semiconductor layer by connecting one electrode to an exposed portion of the semiconductor core and the other electrode to the semiconductor layer. By causing a current to flow between the electrodes, light is emitted from the interface (pn junction) between the outer circumferential surface of the semiconductor core and the inner circumferential surface of the semiconductor layer. In this rod-shaped structure light emitting device, light is emitted from the entire side surface of the semiconductor core covered with the semiconductor layer, so that the light emitting area is widened, so that the light emitting efficiency is high. Further, a quantum well layer may be formed between the outer circumferential surface of the semiconductor core and the inner circumferential surface of the semiconductor layer.

In addition, the cap layer made of a material having a higher electrical resistance than the semiconductor layer covers one end surface of the semiconductor core so that no current flows through the cap layer between the electrode and the semiconductor core connected to the cap layer side of the semiconductor core, while the resistance is higher than that of the cap layer. Through this low semiconductor layer, current flows between the electrode and the outer peripheral surface side of the semiconductor core. As a result, current concentration to the end face of the side where the cap layer of the semiconductor core is provided is suppressed, so that light emission is not concentrated on the end face of the semiconductor core, and the light extraction efficiency from the side surface of the semiconductor core is improved.

Therefore, a fine rod-shaped light emitting device having a simple structure and high light emission efficiency capable of easily connecting electrodes can be realized. Since the rod-shaped light emitting element is not integral with the substrate, it has a high degree of freedom in mounting to the device.

In one embodiment, the outer peripheral surface of the semiconductor core except the exposed portion and the outer peripheral surface of the cap layer are covered by the continuous semiconductor layer.

In one embodiment, the cap layer is made of an insulating material.

In one embodiment, the cap layer is made of an intrinsic semiconductor.

In one embodiment, the cap layer is made of a semiconductor of a first conductivity type.

In one embodiment, the cap layer is made of a semiconductor of the second conductivity type.

In one embodiment, a quantum well layer is formed between the end surface of the semiconductor core and the cap layer.

In one embodiment, a quantum well layer is formed between the outer circumferential surface of the semiconductor core and the semiconductor layer.

In one embodiment, the outer circumferential surface of the semiconductor core except the exposed portion and the outer circumferential surface of the cap layer are covered by the continuous quantum well layer.

In one embodiment, a conductive layer having a lower resistance than the semiconductor layer is formed to cover the semiconductor layer.

In one embodiment, a first electrode is connected to the exposed portion on one end side of the semiconductor core, and a second electrode is connected to the semiconductor layer on the other end side where the cap layer of the semiconductor core is provided.

In one embodiment, a first electrode is connected to the exposed portion on one end side of the semiconductor core, and a second electrode is provided on at least the conductive layer of the semiconductor layer or the conductive layer on the other end side where the cap layer of the semiconductor core is provided. Connected.

In one embodiment, the diameter of the said semiconductor core is 500 nm or more and 100 micrometers or less.

In the light emitting device according to the fifth aspect of the present invention,

Any one of the rod-shaped structure light emitting elements,

The board | substrate with which the said rod-shaped structure light emitting element was mounted so that the longitudinal direction of the said rod-shaped structure light emitting element may become parallel to a mounting surface,

Electrodes are formed on the substrate at predetermined intervals,

On the other end side of the rod-shaped structured light-emitting device, the exposed portion on one end side of the semiconductor core is connected to the other electrode on the substrate, and the cap layer of the semiconductor core is provided on the other electrode on the substrate. The semiconductor layer is connected.

According to the above configuration, in the rod-shaped structured light emitting device mounted on the substrate so that the longitudinal direction thereof becomes parallel to the mounting surface, the heat generated in the rod-shaped structured light emitting device is transferred from the semiconductor layer since the outer peripheral surface of the semiconductor layer is in contact with the mounting surface of the substrate. It is possible to radiate heat efficiently. Therefore, a light emitting device having high luminous efficiency and good heat dissipation can be realized. Further, in the above light emitting device, since the rod-shaped structure light emitting element is laid sideways on the substrate, the thickness including the substrate can be reduced. In the above light emitting device, for example, the amount of a semiconductor to be used by using a micro rod size of 1 μm in diameter and 10 μm in length or a fine rod-shaped structure light emitting element having a nano order size of at least one of diameters or lengths is less than 1 μm. By using the light emitting device, a backlight, a lighting device, a display device, and the like, which can be made thinner and lighter, can be realized.

In the light emitting device according to the sixth aspect of the present invention,

The rod-shaped structure light emitting device in which a conductive layer having a lower resistance than the semiconductor layer is formed to cover the semiconductor layer;

The board | substrate with which the said rod-shaped structure light emitting element was mounted so that the longitudinal direction of the said rod-shaped structure light emitting element may become parallel to a mounting surface,

Electrodes are formed on the substrate at predetermined intervals,

The exposed portion on one end side of the semiconductor core of the rod-shaped structure light emitting device is connected to one of the electrodes on the substrate,

The said conductive layer of the other end side in which the said cap layer of the said semiconductor core was provided is connected to the said other electrode on the said board | substrate, It is characterized by the above-mentioned.

According to the above configuration, in the rod-shaped structured light emitting device mounted on the substrate so that the longitudinal direction thereof becomes parallel to the mounting surface, heat generated in the rod-shaped structured light emitting device is transferred from the conductive layer to the substrate since the outer circumferential surface of the conductive layer contacts the mounting surface of the substrate. It is possible to radiate heat efficiently. Therefore, a light emitting device having high luminous efficiency and good heat dissipation can be realized. Further, in the above light emitting device, since the rod-shaped structure light emitting element is laid sideways on the substrate, the thickness including the substrate can be reduced. In the above light emitting device, for example, the amount of a semiconductor to be used by using a micro rod size of 1 μm in diameter and 10 μm in length or a fine rod-shaped structure light emitting element having a nano order size of at least one of diameters or lengths is less than 1 μm. By using the light emitting device, a backlight, a lighting device, a display device, and the like, which can be made thinner and lighter, can be realized.

In one embodiment, a second conductive layer having a lower resistance than the semiconductor layer is formed on the conductive layer of the rod-shaped light emitting device and on the substrate side.

In one embodiment, a metal part is formed between the said electrodes on the said board | substrate and below the said rod-shaped structure light emitting element.

In one embodiment, the metal portions are formed on the substrate for each of the rod-shaped structure light emitting elements, and the metal portions of the rod-shaped structure light emitting elements adjacent to each other are electrically insulated.

Moreover, in the manufacturing method of the light emitting device by 7th aspect of this invention,

As the manufacturing method of the light-emitting device provided with any one of said rod-shaped structure light emitting elements,

A substrate creation step of creating an insulating substrate on which an array region of two or more electrodes to which independent potentials are applied is formed;

A coating step of applying a liquid including the rod-shaped structure light emitting device having a nano order size or micro order size on the insulating substrate,

The independent voltage is applied to each of the two or more electrodes, thereby arranging the rod-shaped structure light emitting element at a position defined by the two or more electrodes.

According to the said structure, the insulating substrate in which the array area | region formed by the unit of two or more electrodes provided with independent electric potentials each is formed is created, and the said rod-shaped structure light emitting element of nano order size or micro order size is included on this insulating substrate. Apply the liquid. Thereafter, independent voltages are applied to at least the two electrodes, respectively, to arrange the fine rod-shaped structure light emitting elements at positions defined by the two or more electrodes. Thereby, the rod-shaped structure light emitting element can be easily arranged on a predetermined substrate.

In addition, in the method of manufacturing the light emitting device, by using only a fine rod-shaped light emitting device, the amount of semiconductor used can be reduced, and the light emitting device can be made thinner and lighter. In addition, since the rod-shaped light emitting device emits light from the entire side surface of the semiconductor core covered with the semiconductor layer, the light emitting area is widened, thereby achieving a light emitting device having high luminous efficiency and power saving.

The rod-shaped structure light emitting device according to the eighth aspect of the present invention,

A rod-shaped first conductive semiconductor core,

And a second conductive semiconductor layer covering a portion other than the exposed portion of the semiconductor core so as to be an exposed portion without covering a portion on one end side of the semiconductor core,

A stepped portion is formed between the outer circumferential surface of the exposed portion not covered with the semiconductor layer of the semiconductor core and the outer circumferential surface of the covered portion covered with the semiconductor layer of the semiconductor core.

According to the above configuration, the microorder size is covered by covering the coating portions other than the exposed portions of the semiconductor core with the second conductive semiconductor layer so as to be exposed portions without covering the portions on one end side of the rod-shaped first conductive semiconductor core. Even in the case of a fine rod-shaped structure light emitting device having a nano order size, the exposed portion of the semiconductor core can be connected to one electrode and the other electrode can be connected to the semiconductor layer covering the coating portion of the semiconductor core. The rod-shaped structure light emitting device reconnects electrons and holes at an interface (pn junction) between an outer peripheral surface of the semiconductor core and an inner peripheral surface of the semiconductor layer by connecting one electrode to an exposed portion of the semiconductor core and the other electrode to the semiconductor layer. By causing a current to flow between the electrodes, light is emitted from the interface (pn junction) between the outer circumferential surface of the semiconductor core and the inner circumferential surface of the semiconductor layer. In this rod-shaped structure light emitting device, light is emitted from the entire side surface of the semiconductor core covered with the semiconductor layer, so that the light emitting area is widened, so that the light emitting efficiency is high. Further, a quantum well layer may be formed between the outer circumferential surface of the semiconductor core and the inner circumferential surface of the semiconductor layer.

Therefore, a fine rod-shaped light emitting device having a high luminous efficiency that can be easily connected to electrodes with a simple configuration can be realized. Since the rod-shaped light emitting element is not integral with the substrate, it has a high degree of freedom in mounting to the device.

Further, by forming a step between the outer circumferential surface of the exposed portion not covered with the semiconductor layer of the semiconductor core and the outer circumferential surface of the coated portion covered with the semiconductor layer of the semiconductor core, the outer circumferential surface of the exposed portion of the semiconductor core coincides with the outer circumferential surface of the coated portion. As compared with the case where there is no step, the position of the end surface of the semiconductor layer is determined by the stepped portion formed at the boundary between the exposed portion of the semiconductor core and the semiconductor layer, whereby the deviation of the boundary position can be suppressed at the time of manufacture. Here, the exposed portion of the semiconductor core may be a smaller diameter or a larger diameter than the coated portion. In addition, the distance between the outer circumferential surface of the exposed portion of the semiconductor core and the semiconductor layer can be increased by the stepped portion. Therefore, when the electrode is connected to the exposed portion of the semiconductor core, short circuit or leakage current between the electrode and the semiconductor layer can be suppressed. Can be. In addition, since light tends to be drawn out from the stepped portion formed at the boundary between the outer circumferential surface of the exposed portion of the semiconductor core and the outer circumferential surface of the covering portion, the light extraction efficiency is improved. In addition, when the diameter of the exposed portion is larger than the covering portion of the semiconductor core, the contact surface with the electrode connected to the exposed portion of the semiconductor core is taken large, so that the contact resistance can be lowered.

Here, the fine rod-shaped light emitting device is, for example, a micro order size having a diameter of 1 μm and a length of 10 μm, or a nano order size having at least a diameter of less than 1 μm in diameter or length. In addition, the rod-shaped structured light emitting device can reduce the amount of semiconductors used, and it is possible to reduce the thickness and weight of the device using the light emitting device, and to provide high luminous efficiency, power saving light emitting device, backlight, lighting device and display device. Etc. can be realized.

In one embodiment, the outer peripheral length of the cross section orthogonal to the longitudinal direction of the exposed portion of the semiconductor core is shorter than the outer peripheral length of the cross section orthogonal to the longitudinal direction of the coating portion of the semiconductor core.

In one embodiment, the cross section orthogonal to the longitudinal direction of the said coating part of the said semiconductor core is polygonal shape.

In one embodiment, the shape of the cross section orthogonal to the longitudinal direction of the said exposed part of the said semiconductor core differs from the shape of the cross section orthogonal to the longitudinal direction of the said coating part of the said semiconductor core.

In one embodiment, the cross section orthogonal to the longitudinal direction of the exposed portion of the semiconductor core is substantially circular.

In one embodiment, the rod-shaped structure light emitting element is formed to cover the stepped portion of the semiconductor core and the end surface of the semiconductor layer on the side of the stepped portion, and to cover the stepped side of the exposed portion of the semiconductor core. An insulating layer is provided.

In one embodiment, the rod-shaped structure light emitting element is formed to cover the semiconductor layer and includes a conductive layer made of a material having a lower electrical resistance than the semiconductor layer.

In one embodiment, the rod-shaped structure light emitting device includes a quantum well layer formed between the semiconductor core and the semiconductor layer.

In one embodiment, the rod-shaped structure light emitting device has a cap layer formed to cover an end surface on the opposite side of the exposed portion of the semiconductor core, and the cap layer is made of a material having a higher electrical resistance than the semiconductor layer.

In one embodiment, the diameter of the said semiconductor core is 500 nm or more and 100 micrometers or less.

In the light emitting device according to the ninth aspect of the present invention,

Any one of the rod-shaped structure light emitting elements,

The board | substrate with which the said rod-shaped structure light emitting element was mounted so that the longitudinal direction of the said rod-shaped structure light emitting element may become parallel to a mounting surface,

Electrodes are formed on the substrate at predetermined intervals,

The exposed portion on one end side of the semiconductor core of the rod-shaped light emitting element is connected to one electrode on the substrate, and the semiconductor layer on the other end side of the semiconductor core is connected to the other electrode on the substrate. It is characterized by being connected.

According to the above configuration, in the rod-shaped structured light emitting device mounted on the substrate so that the longitudinal direction thereof becomes parallel to the mounting surface, the heat generated in the rod-shaped structured light emitting device is transferred from the semiconductor layer since the outer peripheral surface of the semiconductor layer is in contact with the mounting surface of the substrate. It is possible to radiate heat efficiently. Therefore, a light emitting device having high luminous efficiency and good heat dissipation can be realized. Further, in the above light emitting device, since the rod-shaped structure light emitting element is laid sideways on the substrate, the thickness including the substrate can be reduced. In the above light emitting device, for example, the amount of a semiconductor to be used by using a micro rod size of 1 μm in diameter and 10 μm in length or a fine rod-shaped structure light emitting element having a nano order size of at least one of diameters or lengths is less than 1 μm. By using the light emitting device, a backlight, a lighting device, a display device, and the like, which can be made thinner and lighter, can be realized.

In the light emitting device according to the tenth aspect of the present invention,

A rod-shaped structure light emitting device having a conductive layer formed to cover the semiconductor layer;

The board | substrate with which the said rod-shaped structure light emitting element was mounted so that the longitudinal direction of the said rod-shaped structure light emitting element may become parallel to a mounting surface,

Electrodes are formed on the substrate at predetermined intervals,

The exposed portion on one end side of the semiconductor core of the rod-shaped light emitting element is connected to one electrode on the substrate, and the conductive layer on the other end side of the semiconductor core is connected to the other electrode on the substrate. It is characterized by being connected.

According to the above embodiment, in the rod-shaped structure light emitting element mounted on the substrate so that the longitudinal direction thereof becomes parallel to the mounting surface, the heat generated in the rod-shaped structure light emitting element is transferred from the conductive layer because the outer circumferential surface of the conductive layer and the mounting surface of the substrate are in contact with each other. It is possible to radiate heat efficiently to the substrate. Therefore, a light emitting device having high luminous efficiency and good heat dissipation can be realized. Further, in the above light emitting device, since the rod-shaped structure light emitting element is laid sideways on the substrate, the thickness including the substrate can be reduced. In the above light emitting device, for example, the amount of a semiconductor to be used by using a micro rod size of 1 μm in diameter and 10 μm in length or a fine rod-shaped structure light emitting element having a nano order size of at least one of diameters or lengths is less than 1 μm. By using the light emitting device, a backlight, a lighting device, a display device, and the like, which can be made thinner and lighter, can be realized.

In one embodiment, the light emitting device includes a second conductive layer formed of a material having a lower electrical resistance than the semiconductor layer and formed on the substrate side of the rod-shaped structure light emitting element.

In one embodiment, the light emitting device includes a metal portion formed between the electrodes on the substrate and below the rod-shaped structure light emitting element.

In one embodiment, the metal portions are formed on the substrate for each of the rod-shaped structure light emitting elements, and the metal portions of the rod-shaped structure light emitting elements adjacent to each other are electrically insulated.

Moreover, in the manufacturing method of the light emitting device by 11th aspect of this invention,

As the manufacturing method of the light-emitting device provided with any one of said rod-shaped structure light emitting elements,

A substrate creation step of creating an insulating substrate on which an array region of two or more electrodes to which independent potentials are applied is formed;

A coating step of applying a liquid including the rod-shaped structure light emitting device having a nano order size or micro order size on the insulating substrate,

And an array step of arranging the rod-shaped structure light emitting elements at positions defined by the two or more electrodes by applying the independent voltages to the two or more electrodes, respectively.

According to the said structure, the insulating substrate in which the array area | region formed by the unit of two or more electrodes provided with independent electric potentials each is formed is created, and the said rod-shaped structure light emitting element of nano order size or micro order size is included on this insulating substrate. Apply the liquid. Thereafter, independent voltages are applied to at least the two electrodes, respectively, to arrange the fine rod-shaped structure light emitting elements at positions defined by the two or more electrodes. Thereby, the rod-shaped structure light emitting element can be easily arranged on a predetermined substrate.

In addition, in the method of manufacturing the light emitting device, by using only a fine rod-shaped light emitting device, the amount of semiconductor used can be reduced, and the light emitting device can be made thinner and lighter. In addition, since the rod-shaped light emitting device emits light from the entire side surface of the semiconductor core covered with the semiconductor layer, the light emitting area is widened, thereby achieving a light emitting device having high luminous efficiency and power saving.

In addition, the backlight according to the twelfth aspect of the present invention includes the rod-shaped light emitting device of any one of the first, fourth, and eighth aspects.

According to the above structure, by using the rod-shaped structure light emitting device, it is possible to realize a thinner, lighter weight, high luminous efficiency and a power saving backlight.

In addition, the lighting apparatus according to the thirteenth aspect of the present invention includes the rod-shaped structure light emitting device of any one of the first, fourth, and eighth aspects.

According to the above structure, by using the rod-shaped structure light emitting element, it is possible to realize a lighting device that can be made thinner and lighter, and has high luminous efficiency and power saving.

In addition, the display device according to the fourteenth aspect of the present invention includes the rod-shaped structure light emitting device of any one of the first, fourth, and eighth aspects.

According to the above configuration, by using the rod-shaped structure light emitting device, it is possible to realize a display device that can be thinned and light in weight, and has high luminous efficiency and power saving.

The manufacturing method of the rod-shaped structure light emitting device according to the fifteenth aspect of the present invention,

A semiconductor core forming step of forming a rod-shaped first conductive semiconductor core on a substrate,

A semiconductor layer forming step of forming a cylindrical second conductive semiconductor layer covering a surface of the semiconductor core;

A separation step of separating the semiconductor core having the cylindrical second conductive semiconductor layer formed in the semiconductor layer forming step from the substrate;

And an exposure step of exposing a part of the outer circumferential surface of the semiconductor core after the semiconductor layer forming step and before the separation step or after the separation step.

According to the said structure, after forming a rod-shaped 1st conductivity type semiconductor core on a board | substrate, a cylindrical 2nd conductivity type semiconductor layer is formed so that the surface of a semiconductor core may be covered. Here, the end surface on the opposite side to the substrate of the semiconductor core may be covered with a semiconductor layer or may be exposed. Then, after exposing a part of the outer circumferential surface of the semiconductor core, the semiconductor core including the exposed portion is separated from the substrate, for example by vibrating the substrate by ultrasonic waves or by using a cutting tool. Alternatively, after the semiconductor core having the semiconductor layer is separated from the substrate by vibrating the substrate by, for example, ultrasonic waves or by using a cutting tool, a portion of the outer peripheral surface of the semiconductor core is exposed. The rod-shaped structure light emitting device separated from the substrate in this way connects one electrode to the exposed portion of the semiconductor core and the other electrode to the semiconductor layer, thereby connecting the electrons at the pn junction between the outer circumferential surface of the semiconductor core and the inner circumferential surface of the semiconductor layer. Light is emitted from the pn junction by flowing a current between the electrodes to cause recombination of the holes. In this way, a fine rod-shaped structure light emitting device having a high degree of freedom in mounting to an apparatus can be manufactured. Here, the fine rod-shaped light emitting device is, for example, a micro order size having a diameter of 1 μm and a length of 10 μm, or a nano order size having at least a diameter of less than 1 μm in diameter or length. In addition, the rod-shaped structured light emitting device can reduce the amount of semiconductor used, and it is possible to reduce the thickness and weight of the device using the light emitting device and to emit light from the entire circumference of the semiconductor core covered with the semiconductor layer. Since the light emitting area is wider, a high luminous efficiency and a power saving backlight, lighting device, display device, and the like can be realized.

In one embodiment, in the semiconductor layer forming step, the tubular agent covering the surface of the semiconductor core in a state of covering a part of the outer circumferential surface of the semiconductor core with a material that inhibits formation of the second conductive semiconductor layer. A portion of the outer circumferential surface of the semiconductor core is exposed by forming a biconductive semiconductor layer and removing a substance that inhibits formation of the second conductive semiconductor layer in the exposing step.

In one embodiment, the substrate is made of the semiconductor of the first conductivity type, and the exposing step covers the surface of the semiconductor core in the semiconductor layer of the second conductivity type after the semiconductor layer forming step and before the separation step. A portion of the outer circumferential surface of the semiconductor core is exposed by etching to remove a region except the portion and a portion of the thickness direction of the upper region of the substrate corresponding to the region by etching.

In one embodiment, the exposing step is performed by the second conductive type in a state in which the semiconductor core having the second conductive type semiconductor layer separated from the substrate by the separating step is arranged at a predetermined position on an insulating substrate. A part of the outer circumferential surface of the semiconductor core having the semiconductor layer is exposed.

In one embodiment, in the exposure step, the outer peripheral surface of the substrate side of the semiconductor core is exposed, and in the semiconductor layer forming step, the end surface of the side opposite to the substrate of the semiconductor core is covered with the semiconductor layer. .

In one embodiment, the semiconductor core covered with the semiconductor layer is separated from the substrate using ultrasonic waves in the separation step.

In one embodiment, the semiconductor core is mechanically separated from the substrate using a cutting tool in the separation step.

In one embodiment, the said semiconductor core and the said semiconductor layer consist of a semiconductor which uses GaN as a base material, and dry etching is used in the said exposure process.

In one embodiment, in the exposure step, the outer circumferential surface of the semiconductor core is exposed to be continuous with the outer circumferential surface of the semiconductor layer without a step.

In one embodiment, in the exposure step, the outer circumferential surface of the region covered with the semiconductor layer of the semiconductor core and the outer circumferential surface of the exposed region of the semiconductor core are continuous.

Moreover, in the manufacturing method of the display apparatus by 16th aspect of this invention,

As a manufacturing method of a display device provided with the rod-shaped structure light emitting element manufactured by the manufacturing method of any one of said rod-shaped structure light emitting elements,

A substrate creation step of creating an insulating substrate on which an array region of two or more electrodes to which independent potentials are applied is formed;

A coating step of applying a liquid including the rod-shaped structure light emitting device having a nano order size or micro order size on the insulating substrate,

And an array step of arranging the rod-shaped structure light emitting elements at positions defined by the two or more electrodes by applying the independent voltages to the two or more electrodes, respectively.

According to the said structure, the insulating substrate in which the array area | region formed by the unit of two or more electrodes provided with independent electric potentials each is formed is created, and the said rod-shaped structure light emitting element of nano order size or micro order size is included on this insulating substrate. Apply the liquid. Thereafter, independent voltages are applied to at least the two electrodes, respectively, to arrange the fine rod-shaped structure light emitting elements at positions defined by the two or more electrodes. Thereby, the rod-shaped structure light emitting element can be easily arranged on a predetermined substrate.

In addition, in the method of manufacturing the display device, by using only a fine rod-shaped light emitting device, it is possible to reduce the amount of semiconductor used and to manufacture a display device that can be thinner and lighter. In addition, the rod-shaped structure light emitting device emits light from the entire circumference of the semiconductor core covered with the semiconductor layer, thereby widening the light emitting area, thereby realizing a display device having high luminous efficiency and power saving.

The manufacturing method of the rod-shaped structure light emitting device according to the seventeenth aspect of the present invention,

An insulator formation step of forming an insulator having a through hole on the substrate;

A semiconductor core forming step of forming a rod-shaped first conductive semiconductor core so as to protrude from the through hole on the surface of the substrate overlapping the through hole;

A semiconductor layer forming step of forming a second conductive semiconductor layer so as to cover the semiconductor core protruding from the through hole;

An insulator etching step of etching the insulator so that a part of the insulator remains on at least a portion of the outer circumference not covered with the semiconductor layer of the semiconductor core, covered by the semiconductor layer of the semiconductor core;

In the said semiconductor core, the said semiconductor layer, and the said insulator etching process, the isolation | separation process of separating the rod-shaped structure light emitting element which has a part of the said insulator which remain on the said board | substrate from the said board | substrate is provided.

Here, the first conductivity type means p-type or n-type. The second conductivity type means n type when the first conductivity type is p type and p type when n type.

According to the said structure, after forming the insulator which has a through-hole on the said board | substrate, the rod-shaped 1st conductivity type semiconductor core is formed so that it may protrude from a through-hole on the surface of the board | substrate exposed from the through-hole.

Subsequently, the second conductive semiconductor layer is formed so as to cover the semiconductor core protruding from the through hole, and at least near the outer circumferential surface covered with the semiconductor layer of the semiconductor core among the outer circumferential surfaces not covered with the semiconductor layer of the semiconductor core. The insulator is etched so that a portion of the insulator remains on the portion of. As a result, the second conductive semiconductor layer can cover one end side (the side opposite to the substrate side) of the semiconductor core, and can cover at least the part of the other end side (substrate side) of the semiconductor core with a part of the insulator.

Then, the rod-shaped structured light emitting element having the semiconductor core, the semiconductor layer, and a part of the insulator remaining on the substrate is separated from the substrate, for example by vibrating the substrate by ultrasonic waves or by using a cutting tool.

In this way, since the rod-shaped light emitting device is separated from the substrate, the degree of freedom in mounting the rod-shaped light emitting device to the device is increased, so that a fine rod-shaped light emitting device having a high degree of freedom in mounting to the device can be manufactured.

Here, the fine rod-shaped light emitting device is, for example, a size that falls within the range of 10 nm to 5 µm, and a length falls within the range of 100 nm to 200 µm, and more preferably from 100 nm to 2 µm in diameter. It is an element of the size which falls in the range of and whose length falls in the range from 1 micrometer to 50 micrometers.

Further, since the rod-shaped first conductive semiconductor core is formed on the surface of the substrate overlapping the through hole, the rod-shaped first conductive semiconductor core can be uniformly made thick.

In addition, since the substrate is separated from the rod-shaped light emitting device, it is not necessary to use the substrate when emitting the rod-shaped light emitting device. Therefore, the choice of the board | substrate used at the time of light emission of the said rod-shaped structure light emitting element increases, and the freedom of the form of the apparatus which should mount the rod-shaped structure light emitting element becomes high.

When the rod-shaped structure light emitting device is separated from the substrate, the semiconductor is formed by a boundary (undesired point) between a region covered with the second conductive semiconductor layer and a region not covered with the second conductive semiconductor layer. The location where the core is likely to be bent is reinforced by the insulator remaining on the semiconductor core. Therefore, the rod-shaped structure light emitting element is easily cut out from the desired location, that is, the source of the semiconductor core. Therefore, even if a plurality of rod-shaped light emitting elements are manufactured, the length of the plurality of rod-shaped light emitting elements can be uniformly obtained.

In addition, since the substrate used for forming the rod-shaped light emitting device can be reused in manufacturing the rod-shaped light emitting device after separating the rod-shaped light emitting device, the manufacturing cost can be reduced.

In addition, since the rod-shaped light emitting device can be made finer and the amount of semiconductor used can be reduced, the device to which the rod-shaped light emitting device is to be mounted can be made thinner and lighter, thereby reducing the load on the environment.

In addition, according to the above-described manufacturing method, an insulator can cover a portion near the outer circumferential surface covered with the semiconductor layer on at least one end side of the semiconductor core among the outer circumferential surfaces not covered with the semiconductor layer on the other end side of the semiconductor core. have. The rod-shaped structure light emitting device is formed by connecting an electrode on the first conductive side to a portion not covered with an insulator on the other end side of the semiconductor core and connecting an electrode on the second conductive side to the semiconductor layer to flow current between the electrodes. Emits light.

In addition, according to the above-described manufacturing method, since the one end side of the semiconductor core can be covered with the second conductive semiconductor layer, the light emitting area can be increased to increase the amount of emitted light, and the light emitting efficiency can be improved.

In addition, according to the above-described manufacturing method, an insulator can cover a portion near the outer circumferential surface covered with the semiconductor layer on at least one end side of the semiconductor core among the outer circumferential surfaces not covered with the semiconductor layer on the other end side of the semiconductor core. Therefore, the short circuit of the electrode of the 1st conductive side can be prevented.

The manufacturing method of the rod-shaped structure light emitting device according to the eighteenth aspect of the present invention,

A base layer forming step of forming a base layer made of a first conductive semiconductor on a substrate,

An insulator formation step of forming an insulator having a through hole on the base layer;

A semiconductor core forming step of forming a rod-shaped first conductive semiconductor core so as to protrude from the through hole on the surface of the base layer overlapping the through hole;

A semiconductor layer forming step of forming a second conductive semiconductor layer so as to cover the semiconductor core protruding from the through hole;

At the end of the substrate side of the semiconductor core so that a part of the insulator remains on at least a portion of the outer circumferential surface not covered with the semiconductor layer of the semiconductor core, covered by the semiconductor layer of the semiconductor core. An etching step of etching the insulator and the underlayer so that a part of the underlayer continues in succession;

A rod-shaped structure light emitting element having the semiconductor core, the semiconductor layer, a part of the insulator remaining on the substrate in the etching process, and a part of the base layer remaining on the substrate in the etching process, is formed from the substrate. A separation process for separating is provided.

Here, the first conductivity type means p-type or n-type. The second conductivity type means n type when the first conductivity type is p type and p type when n type.

According to the said structure, after forming the underlayer which consists of a semiconductor of a 1st conductivity type on the said board | substrate, and forming the insulator which has a through hole on the underlayer, on the surface of the underlayer exposed from the through hole, The rod-shaped first conductive semiconductor core is formed so as to protrude from the through hole.

Subsequently, the second conductive semiconductor layer is formed so as to cover the semiconductor core protruding from the through hole, and at least near the outer circumferential surface covered with the semiconductor layer of the semiconductor core among the outer circumferential surfaces not covered with the semiconductor layer of the semiconductor core. The insulator and the underlayer are etched so that a part of the insulator remains on the portion of the semiconductor core, and a part of the underlayer which continues at the end of the substrate side of the semiconductor core remains. As a result, the second conductive semiconductor layer can cover one end side (the side opposite to the substrate side) of the semiconductor core, and can cover at least the part of the other end side (substrate side) of the semiconductor core with a part of the insulator. In addition, an outer circumferential surface of a part of the underlayer may be exposed.

Subsequently, a rod-shaped structure light emitting device having the semiconductor core, the semiconductor layer, a part of the insulator remaining on the substrate, and a part of the underlayer remaining on the substrate, for example, by vibrating the substrate by ultrasonic or using a cutting tool Separate from the substrate. Thereby, the axial end surface (end surface which contacted the board | substrate) on the opposite side to the semiconductor core side of the said base layer can be exposed.

In this way, since the rod-shaped light emitting device is separated from the substrate, the degree of freedom in mounting the rod-shaped light emitting device to the device is increased, so that a fine rod-shaped light emitting device having a high degree of freedom in mounting to the device can be manufactured.

Here, the fine rod-shaped light emitting device is, for example, a size that falls within the range of 10 nm to 5 µm, and a length falls within the range of 100 nm to 200 µm, and more preferably from 100 nm to 2 µm in diameter. It is an element of the size which falls in the range of and whose length falls in the range from 1 micrometer to 50 micrometers.

Further, since the rod-shaped first conductive semiconductor core is formed on the surface of the substrate overlapping the through hole, the rod-shaped first conductive semiconductor core can be uniformly made thick.

In addition, since the substrate is separated from the rod-shaped light emitting device, it is not necessary to use the substrate when the rod-shaped light emitting device emits light. Therefore, the choice of the board | substrate used at the time of light emission of the said rod-shaped structure light emitting element increases, and the freedom of the form of the apparatus which should mount the rod-shaped structure light emitting element becomes high.

When the rod-shaped structure light emitting device is separated from the substrate, the semiconductor is formed by a boundary (undesired point) between a region covered with the second conductive semiconductor layer and a region not covered with the second conductive semiconductor layer. The location where the core is likely to be bent is reinforced by the insulator remaining on the semiconductor core. Therefore, the rod-shaped structure light emitting element is easily cut out from the desired location, that is, the source of the semiconductor core. Therefore, even if a plurality of rod-shaped light emitting elements are manufactured, the length of the plurality of rod-shaped light emitting elements can be uniformly obtained.

In addition, since the substrate used to form the rod-shaped light emitting device can be reused in the manufacture of the rod-shaped light emitting device after separating the rod-shaped light emitting device, the manufacturing cost can be reduced.

In addition, since the rod-shaped light emitting device can be made finer and the amount of semiconductor used can be reduced, the device to which the rod-shaped light emitting device is to be mounted can be made thinner and lighter, thereby reducing the load on the environment.

Moreover, by the manufacturing method mentioned above, the axial end surface and the peripheral surface of a base layer on the opposite side to the semiconductor core side of a base layer can be exposed. The rod-shaped light emitting device emits light when an electrode on the first conductive side is connected to at least one of the end surface and the circumferential surface, and an electrode on the second conductive side is connected to the semiconductor layer to flow a current between the electrodes.

In addition, according to the above-described manufacturing method, since the one end side of the semiconductor core can be covered with the second conductive semiconductor layer, the light emitting area can be increased to increase the amount of emitted light, and the light emitting efficiency can be improved.

In addition, according to the above-described manufacturing method, an insulator can cover a portion near the outer circumferential surface covered with the semiconductor layer on at least one end side of the semiconductor core among the outer circumferential surfaces not covered with the semiconductor layer on the other end side of the semiconductor core. Therefore, the short circuit of the electrode of the 1st conductive side can be prevented.

In one embodiment, a quantum well layer is formed between the semiconductor core and the semiconductor layer.

The rod-shaped structure light emitting device according to the nineteenth aspect of the present invention,

A rod-shaped first conductive semiconductor core,

A second conductive semiconductor layer covering one end side of the semiconductor core;

And an insulator covering at least a portion of the outer circumferential surface of the semiconductor core that is covered by the semiconductor layer of the semiconductor core, among the outer circumferential surfaces that are not covered by the semiconductor layer.

Here, the first conductivity type means p-type or n-type. The second conductivity type means n type when the first conductivity type is p type and p type when n type.

According to the said structure, at least the semiconductor layer of the semiconductor core of the rod-shaped 1st conductive semiconductor core, the 2nd conductive semiconductor layer which covers the one end side of a semiconductor core, and the outer peripheral surface not covered with the semiconductor layer of the semiconductor core Since the insulator which covers the part of the vicinity of the outer peripheral surface covered with this is provided, it can manufacture by the manufacturing method of the rod-shaped structure light emitting element of this invention.

In addition, the rod-shaped structure light emitting device is formed by connecting an electrode on the first conductive side to a portion not covered with an insulator on the other end side of the semiconductor core and connecting an electrode on the second conductive side to the semiconductor layer to flow current between the electrodes. Emits light. At this time, since the second conductive semiconductor layer covers one end side of the semiconductor core, the light emitting region is widened. Therefore, the light emission amount can be increased and the light emission efficiency can be improved.

Further, even when the rod-shaped structure light emitting device is fine, at least an end surface in the axial direction is exposed among the end portions on the other end side of the semiconductor core, so that the electrode on the first conductive side can be easily connected to this end surface.

Moreover, the insulator which covers the part of the outer peripheral surface vicinity covered with the semiconductor layer of the semiconductor core at least among the outer peripheral surfaces which are not covered by the semiconductor layer of the said semiconductor core is equipped with the electrode of a 1st conductive side short-circuited with the electrode of a 2nd conductive side. Since it becomes difficult to form, formation of the electrode of a 1st conductive side and the electrode of a 2nd conductive side becomes easy.

Here, the fine rod-shaped light emitting device is a size in which the rod-shaped light emitting device falls within a range of, for example, a diameter of 10 nm to 5 m, and a length falls within a range of 100 nm to 200 m, more preferably a diameter. It means that it has a size which falls in the range from 100 nm to 2 micrometers, and whose length falls in the range from 1 micrometer to 50 micrometers.

The rod-shaped structure light emitting device according to the twentieth aspect of the present invention,

A rod-shaped first conductive semiconductor core,

A second conductive semiconductor layer covering one end side of the semiconductor core;

An insulator covering at least a portion of an outer circumferential surface of the semiconductor core that is covered by the semiconductor layer of the semiconductor core, among the outer circumferential surfaces that are not covered by the semiconductor layer;

And a base layer of a first conductivity type connected to the other end of the semiconductor core,

An axial end face on the side opposite to the semiconductor core side of the underlayer and the peripheral surface of the underlayer are exposed.

Here, the first conductivity type means p-type or n-type. The second conductivity type means n type when the first conductivity type is p type and p type when n type.

According to the said structure, at least the semiconductor layer of the semiconductor core of the rod-shaped 1st conductive semiconductor core, the 2nd conductive semiconductor layer which covers the one end side of a semiconductor core, and the outer peripheral surface not covered with the semiconductor layer of the semiconductor core And an insulator covering a portion near the outer circumferential surface covered with a film, and an underlayer of a first conductivity type connected to the other end of the semiconductor core, the axial end surface on the side opposite to the semiconductor core side of the underlayer and the circumferential surface of the underlayer. Since it is exposed, it can manufacture with the manufacturing method of the rod-shaped structure light emitting element of this invention.

For example, the electrode of the 1st conductive side is connected to at least one of the axial end surface on the opposite side to the semiconductor core side of the said base layer, and the circumferential surface of the base layer, and the electrode of the 2nd conductive side is connected to a semiconductor layer, and between electrodes The rod-shaped light emitting device emits light when a current is sent. At this time, since the second conductive semiconductor layer covers one end side of the semiconductor core, the light emitting region is widened. Therefore, the light emission amount can be increased and the light emission efficiency can be improved.

Further, even when the rod-shaped structure light emitting device is fine, the first conductive side is exposed to at least one of the axial end surface and the circumferential surface of the base layer because the end surface and the circumferential surface of the base layer opposite to the semiconductor core side of the base layer are exposed. Can be easily connected.

Moreover, the insulator which covers the part of the outer peripheral surface vicinity covered with the semiconductor layer of the semiconductor core at least among the outer peripheral surfaces which are not covered by the semiconductor layer of the said semiconductor core is equipped with the electrode of a 1st conductive side short-circuited with the electrode of a 2nd conductive side. Since it becomes difficult to form, formation of the electrode of a 1st conductive side and the electrode of a 2nd conductive side becomes easy.

Here, the fine structure of a rod-shaped structure light emitting element is, for example, a size that falls within a range of 10 nm to 5 µm and a length falls within a range of 100 nm to 200 µm, more preferably, a diameter ranges from 100 nm to 2 µm. It means to have a size that falls within the range up to 탆 and the length falls within the range from 1 탆 to 50 탆.

A backlight according to a twenty-first aspect of the present invention includes the rod-shaped structure light emitting device according to the nineteenth or twentieth aspect of the present invention.

According to the said structure, since the rod-shaped structure light emitting element is provided, a backlight with high luminous efficiency and power saving can be realized.

A lighting apparatus according to a twenty-second aspect of the present invention is provided with a rod-shaped structure light emitting element according to the nineteenth or twentieth aspect of the present invention.

According to the said structure, since the rod-shaped structure light emitting element is provided, the lighting device with high luminous efficiency and power saving can be realized.

A display device according to a twenty-third aspect of the present invention is provided with a rod-shaped structure light emitting element according to the nineteenth or twentieth aspect of the present invention.

According to the said structure, since the rod-shaped structure light emitting element is provided, a display device with high luminous efficiency and power saving can be realized.

In order to solve the said subject, the light-emitting device by 24th aspect of this invention,

A rod-shaped structure light emitting device having a rod-shaped first conductive semiconductor core and a second conductive semiconductor layer formed to cover the semiconductor core, and having an outer peripheral surface of a portion of the semiconductor core exposed;

A substrate on which the rod-shaped light emitting device is mounted is provided so that the longitudinal direction of the rod-shaped light emitting device is parallel to the mounting surface.

According to the said structure, the rod-shaped structure light emitting element which has a rod-shaped 1st conductivity type semiconductor core and the 2nd conductivity type semiconductor layer formed so that the semiconductor core may be covered, and the outer peripheral surface of a part of a semiconductor core was exposed is formed in the rod shape. It mounts on a board | substrate so that the longitudinal direction of a structure light emitting element may become parallel to the mounting surface of a board | substrate. The rod-shaped structure light emitting device connects one electrode to the exposed portion of the semiconductor core and the other electrode to the semiconductor layer so that recombination of electrons and holes occurs at the pn junction between the outer circumferential surface of the semiconductor core and the inner circumferential surface of the semiconductor layer. By flowing a current between the electrodes, light is emitted from the pn junction, i.e., the entire circumference of the semiconductor core. As a result, the rod-shaped structure light emitting device has a high light emission efficiency because the light emitting area is widened. In addition, the rod-shaped light emitting device mounted on the substrate such that the longitudinal direction of the rod-shaped light emitting device is parallel to the mounting surface of the substrate is formed in the rod-shaped light emitting device because the outer circumferential surface of the semiconductor layer is in contact with the mounting surface of the substrate. The heat can be efficiently radiated from the semiconductor layer to the substrate. Therefore, a light emitting device having high luminous efficiency and good heat dissipation can be realized. Further, in the above light emitting device, since the rod-shaped structure light emitting element is laid sideways on the substrate, the thickness including the substrate can be reduced. In the above light emitting device, for example, a semiconductor having a micro rod size having a diameter of 1 μm and a length of 10 μm or a fine rod-shaped structure light emitting element having a nano order size of at least one of diameters or lengths of less than 1 μm is used. The amount can be reduced, and the light emitting device can be used to realize a backlight, a lighting device, a display device, and the like, which can be made thinner and lighter.

In one embodiment, the outer peripheral surface of the one end side of the said semiconductor core is exposed.

In one embodiment, the end surface of the other end side of the said semiconductor core is covered with the said semiconductor layer.

In one embodiment, the outer circumferential surface of the exposed region of the semiconductor core substantially coincides with the extended surface of the outermost circumferential surface of the region covered with the semiconductor layer.

In one embodiment, the outer peripheral surface of the area | region covered with the said semiconductor layer of the said semiconductor core and the outer peripheral surface of the exposed area | region of the said semiconductor core are continuous.

In one embodiment, a quantum well layer is formed between the semiconductor core and the semiconductor layer of the rod-shaped light emitting device.

In one embodiment, a transparent electrode is formed to cover the semiconductor layer of the rod-shaped structure light emitting device.

In the light emitting device of one embodiment, a metal layer is formed on the transparent electrode of the rod-shaped light emitting device and on the substrate side.

In one embodiment,

The rod-shaped structure light emitting device has an exposed portion where the outer peripheral surface of one end is exposed,

Electrodes are formed on the substrate at predetermined intervals,

The exposed portion at one end of the rod-shaped light emitting element is connected to the one electrode on the substrate, and the semiconductor layer at the other end of the rod-shaped light emitting element is connected to the other electrode on the substrate. Become,

A metal part is formed between the electrodes on the substrate and below the rod-shaped structure light emitting device.

The twenty-fifth aspect of the present invention is further provided with the light-emitting device of the twenty-fourth aspect.

According to the above structure, a backlight having high luminous efficiency and good power saving heat dissipation can be realized by using the light emitting device. In addition, by using a fine rod-shaped structure light emitting element in the light emitting device, the amount of semiconductor used can be reduced, and thickness and weight can be realized.

A lighting device according to a twenty-sixth aspect of the present invention is further provided with a light emitting device according to the twenty-fourth aspect.

According to the above constitution, by using the light emitting device, it is possible to realize a lighting device having high luminous efficiency and good power saving heat dissipation. In addition, by using a fine rod-shaped structure light emitting element in the light emitting device, the amount of semiconductor used can be reduced, and thickness and weight can be realized.

In addition, the display device according to the twenty-seventh aspect of the present invention includes the light emitting device according to the twenty-fourth aspect.

According to the above structure, by using the light emitting device, a display device having high luminous efficiency and good heat-saving heat dissipation can be realized. In addition, by using a fine rod-shaped structure light emitting element in the light emitting device, the amount of semiconductor used can be reduced, and thickness and weight can be realized.

The invention will be more fully understood from the following detailed description and the accompanying drawings. The accompanying drawings are for illustrative purposes only and do not limit the invention.

1 is a perspective view of a rod-shaped structure light emitting device according to a first embodiment of the present invention.
It is a perspective view of the rod-shaped structure light emitting element of 2nd Embodiment of this invention.
It is a perspective view of the rod-shaped structure light emitting element of 3rd Embodiment of this invention.
4 is a perspective view of a rod-shaped structure light emitting device according to a fourth embodiment of the present invention.
5 is a cross-sectional view of the rod-shaped structure light emitting device.
6 is a cross-sectional view for explaining electrode connection of the rod-shaped structure light emitting device.
Fig. 7 is a perspective view of a rod-shaped rod-shaped structure light emitting element having another hexagonal cross section.
Fig. 8 is a perspective view of a rod-shaped rod-shaped light emitting device having another hexagonal cross section.
Fig. 9 is a perspective view of a rod-shaped rod-shaped light emitting device having another hexagonal cross section.
Fig. 10 is a perspective view of a rod-shaped rod-shaped light emitting device having another hexagonal cross section.
It is sectional drawing of the rod-shaped structure light emitting element of 5th Embodiment of this invention.
It is a cross-sectional schematic diagram of the principal part of the rod-shaped structure light emitting element.
It is a cross-sectional schematic diagram of the principal part of the rod-shaped structure light emitting element of a comparative example.
It is sectional drawing of the rod-shaped structure light emitting element of 6th Embodiment of this invention.
15 is a schematic sectional view of a main portion of the rod-shaped light emitting device.
It is a cross-sectional schematic diagram of the principal part of the rod-shaped structure light emitting element of a comparative example.
17A is a flowchart of the method of manufacturing the rod-shaped structure light emitting device according to the seventh embodiment of the present invention.
17B is a flowchart of the method of manufacturing a rod-shaped structure light emitting device, continued from FIG. 17A.
17C is a flowchart of the method of manufacturing the rod-shaped structure light emitting device, continued from FIG. 17B.
17D is a flowchart of the method of manufacturing the rod-shaped structure light emitting device subsequent to FIG. 17C.
17E is a flowchart of the method of manufacturing the rod-shaped structure light emitting device subsequent to FIG. 17D.
18A is a flowchart of a method of manufacturing a rod-shaped structure light emitting device according to an eighth embodiment of the present invention.
18B is a flowchart of the method of manufacturing the rod-shaped structure light emitting device, continued from FIG. 18A.
18C is a flowchart of a method of manufacturing a rod-shaped structure light emitting device subsequent to FIG. 18B.
18D is a flowchart of the method of manufacturing the rod-shaped structure light emitting device, continued from FIG. 18C.
18E is a flowchart of a method of manufacturing a rod-shaped structure light emitting device subsequent to FIG. 18D.
It is process drawing of the manufacturing method of the rod-shaped structure light emitting element of 9th Embodiment of this invention.
19B is a flowchart of a method of manufacturing a rod-shaped structure light emitting device subsequent to FIG. 19A.
19C is a flowchart of a method of manufacturing a rod-shaped structure light emitting device subsequent to FIG. 19B.
19D is a flowchart of a method of manufacturing a rod-shaped structure light emitting device subsequent to FIG. 19C.
19E is a flowchart of a method of manufacturing a rod-shaped structure light emitting device subsequent to FIG. 19D.
20 is a cross-sectional view of a rod-shaped structure light emitting device of a tenth embodiment of the present invention.
It is a cross-sectional schematic diagram of the principal part of the rod-shaped structure light emitting element of a comparative example.
It is a cross-sectional schematic diagram of the principal part of the rod-shaped structure light emitting element of the tenth embodiment.
It is sectional drawing of the principal part of the 1st modified example of the rod-shaped structure light emitting element of said 10th embodiment.
It is sectional drawing of the principal part of the 2nd modified example of the rod-shaped structure light emitting element of said 10th embodiment.
It is sectional drawing of the principal part of the 3rd modified example of the rod-shaped structure light emitting element of 10th embodiment.
It is a cross-sectional schematic diagram of the principal part of the rod-shaped structure light emitting element of the modification which does not cover the outer peripheral surface of a cap layer.
25 is a schematic sectional view of a main portion of a rod-shaped structure light emitting device of another modification, in which the semiconductor layer does not cover the outer circumferential surface of the cap layer.
It is sectional drawing of the rod-shaped structure light emitting element of 11th Embodiment of this invention.
It is sectional drawing of the rod-shaped structure light emitting element of 12th Embodiment of this invention.
28 is a schematic sectional view of a main portion of the rod-shaped light emitting device.
It is sectional drawing of the principal part of the 1st modified example of the rod-shaped structure light emitting element of said 12th embodiment.
It is sectional drawing of the principal part of the 2nd modified example of the rod-shaped structure light emitting element of the twelfth embodiment.
It is sectional drawing of the principal part of the 3rd modified example of the rod-shaped structure light emitting element of the twelfth embodiment.
30 is a schematic sectional view of a main portion of a rod-shaped structure light emitting device of a modification in which the outer circumferential surface of the cap layer is not covered with the quantum well layer and the semiconductor layer.
31 is a schematic sectional view of a main portion of a rod-shaped structure light emitting device according to another modification in which the outer circumferential surface of the cap layer is not covered with the quantum well layer and the semiconductor layer.
32 is a cross-sectional view of a rod-shaped structure light emitting device of a thirteenth embodiment of the present invention.
It is a cross-sectional schematic diagram of the principal part of the rod-shaped structure light emitting element.
34 is a cross-sectional view for explaining electrode connection of the rod-shaped structure light emitting device.
It is a perspective view of the light emitting device provided with the rod-shaped structure light emitting element of 14th Embodiment of this invention.
Fig. 36 is a side view of a light emitting device including a rod-shaped structure light emitting element according to a fifteenth embodiment of the present invention.
37 is a cross-sectional view of the light emitting device.
38 is a perspective view of a light emitting device of a sixteenth embodiment of the present invention;
Fig. 39 is a plan view of a main portion in which the adjacent rod-shaped light emitting elements are in the reverse state in the above light emitting device.
40A is a flowchart of the method of manufacturing the rod-shaped structure light emitting device of the seventeenth embodiment of the present invention.
40B is a flowchart of the method of manufacturing a rod-shaped structure light emitting device, continued from FIG. 40A.
40C is a flowchart of the method of manufacturing a rod-shaped structure light emitting device subsequent to FIG. 40B.
40D is a flowchart of the method of manufacturing the rod-shaped structure light emitting device subsequent to FIG. 40C.
41A is a flowchart of the method of manufacturing the rod-shaped structure light emitting device of the eighteenth embodiment of the present invention.
41B is a flowchart of the method of manufacturing the rod-shaped structure light emitting device subsequent to FIG. 41A.
41C is a flowchart of the method of manufacturing a rod-shaped structure light emitting device subsequent to FIG. 41B.
41D is a flowchart of the method of manufacturing the rod-shaped structure light emitting device subsequent to FIG. 41C.
41E is a flowchart of the method of manufacturing the rod-shaped structure light emitting device subsequent to FIG. 41D.
42A is a flowchart of the method of manufacturing the rod-shaped structure light emitting device of the nineteenth embodiment of the present invention.
42B is a flowchart of the method of manufacturing the rod-shaped structure light emitting device subsequent to FIG. 42A.
42C is a flowchart of the method of manufacturing the rod-shaped structure light emitting device subsequent to FIG. 42B.
FIG. 42D is a flowchart of the method of manufacturing the rod-shaped structure light emitting device subsequent to FIG. 42C. FIG.
42E is a flowchart of the method of manufacturing the rod-shaped structure light emitting device subsequent to FIG. 42D.
Fig. 43 is a perspective view of the rod-shaped structure light emitting device of the twentieth embodiment of the present invention.
44 is a cross-sectional view of the rod-shaped structure light emitting device.
It is a cross-sectional schematic diagram of the principal part of the rod-shaped structure light emitting element of a comparative example.
It is a cross-sectional schematic diagram of the principal part of the rod-shaped structure light emitting element of the twentieth embodiment.
Fig. 47 is a cross-sectional view of relevant parts of a modification of the rod-shaped structure light emitting device of the twentieth embodiment.
It is sectional drawing of the principal part for demonstrating the electrode connection of the exposed part of the semiconductor core of the rod-shaped structure light emitting element.
Fig. 49 is a perspective view of the rod-shaped structure light emitting device of the twenty-first embodiment of the present invention.
It is a cross-sectional schematic diagram of the principal part of the rod-shaped structure light emitting element of the twenty-first embodiment.
It is a cross-sectional schematic diagram of the exposed part of the semiconductor core of the rod-shaped structure light emitting element of the twentieth embodiment.
It is a cross-sectional schematic diagram of the exposed part of the semiconductor core of the rod-shaped structure light emitting element of the twenty-first embodiment.
51C is a schematic sectional view of an exposed portion of a semiconductor core of a rod-shaped structure light emitting device of a modification.
Fig. 52 is a perspective view of a rod-shaped structure light emitting device of a twenty second embodiment of the present invention.
It is a cross-sectional schematic diagram of the 1st modified example of the rod-shaped structure light emitting element of the 22nd embodiment.
It is a cross-sectional schematic diagram of the 2nd modified example of the rod-shaped structure light emitting element of the 22nd embodiment.
Fig. 55 is a cross-sectional view of a rod-shaped structure light emitting device of a twenty third embodiment of the present invention.
Fig. 56 is a perspective view of the rod-shaped structure light emitting device.
Fig. 57 is a cross sectional view of the rod-shaped structure light emitting device of the twenty-fourth embodiment of the present invention.
Fig. 58 is a perspective view of the rod-shaped structure light emitting device.
Fig. 59 is a perspective view of a rod-shaped structure light emitting device of a 25th embodiment of the present invention.
Fig. 60 is a perspective view of a rod-shaped structure light emitting device of a twenty sixth embodiment of the present invention.
Fig. 61 is a cross-sectional view of the rod-shaped structure light emitting device of the 27th embodiment of the present invention.
Fig. 62 is a schematic cross-sectional view of relevant parts of the rod-shaped structure light emitting device of the 27th embodiment.
Fig. 63 is a perspective view of a light emitting device including a rod-shaped structure light emitting element according to a twenty eighth embodiment of the present invention.
64 is a side view of a light emitting device including a rod-shaped structure light emitting element according to a twenty-ninth embodiment of the present invention.
65 is a cross-sectional view of the light emitting device.
66 is a perspective view of a light emitting device of a thirtieth embodiment of the present invention;
Fig. 67 is a plan view of a main portion in which the adjacent rod-shaped structure light emitting elements are in the reverse state in the above light emitting device.
68A is a flowchart of the method of manufacturing the rod-shaped structure light emitting device of the thirty-first embodiment of the present invention.
68B is a flowchart of the method of manufacturing the rod-shaped structure light emitting device subsequent to FIG. 68A.
68C is a flowchart of the method of manufacturing a rod-shaped structure light emitting device subsequent to FIG. 68B.
68D is a flowchart of the method of manufacturing the rod-shaped structure light emitting device subsequent to FIG. 68C.
68E is a flowchart of the method of manufacturing a rod-shaped structure light emitting device subsequent to FIG. 68D.
69A is a flowchart of the manufacturing method of the rod-shaped structure light emitting device of the thirty-second embodiment of the present invention.
69B is a flowchart of the method of manufacturing a rod-shaped structure light emitting device subsequent to FIG. 69A.
69C is a flowchart of the method of manufacturing a rod-shaped structure light emitting device subsequent to FIG. 69B.
69D is a flowchart of the method of manufacturing a rod-shaped structure light emitting device subsequent to FIG. 69C.
69E is a flowchart of the method of manufacturing the rod-shaped structure light emitting device subsequent to FIG. 69D.
70A is a flowchart of the method of manufacturing the rod-shaped structure light emitting device of the 33rd embodiment of the present invention.
70B is a flowchart of the method of manufacturing the rod-shaped structure light emitting device subsequent to FIG. 70A.
70C is a flowchart of the method of manufacturing the rod-shaped structure light emitting device subsequent to FIG. 70B.
70D is a flowchart of the method of manufacturing the rod-shaped structure light emitting device subsequent to FIG. 70C.
71A is a flowchart of the method of manufacturing the rod-shaped structure light emitting device of the 34th embodiment of the present invention.
71B is a flowchart of the method of manufacturing a rod-shaped structure light emitting device subsequent to FIG. 71A.
71C is a flowchart of the method of manufacturing the rod-shaped structure light emitting device subsequent to FIG. 71B.
71D is a flowchart of the method of manufacturing the rod-shaped structure light emitting device subsequent to FIG. 71C.
Fig. 72 is a flowchart of the manufacturing method of the rod-shaped structure light emitting device of the 35th embodiment of the present invention.
73 is a flowchart of the method of manufacturing a rod-shaped structure light emitting device continued from FIG. 72.
74 is a flowchart of the method of manufacturing a rod-shaped structure light emitting device subsequent to FIG. 73.
75 is a flowchart of a method of manufacturing a rod-shaped structure light emitting device subsequent to FIG. 74.
76 is a flowchart of the method of manufacturing a rod-shaped structure light emitting device subsequent to FIG. 75.
77 is a flowchart of the method of manufacturing the rod-shaped structure light emitting device subsequent to FIG. 76.
78 is a flowchart of the method of manufacturing a rod-shaped structure light emitting device subsequent to FIG. 77.
79 is a flowchart of the method of manufacturing a rod-shaped structure light emitting device subsequent to FIG. 78.
80 is a flowchart of the method of manufacturing a rod-shaped structure light emitting device continued from FIG. 79.
81 is a flowchart of the method of manufacturing a rod-shaped structure light emitting device subsequent to FIG. 80.
82 is a flowchart of the method of manufacturing a rod-shaped structure light emitting device subsequent to FIG. 81.
83 is a flowchart of the method of manufacturing the rod-shaped structure light emitting device subsequent to FIG. 82.
84 is a flowchart of the method of manufacturing a rod-shaped structure light emitting device subsequent to FIG. 83.
85 is a flowchart of the method of manufacturing a rod-shaped structure light emitting device subsequent to FIG. 84.
86 is a flowchart of the method of manufacturing a rod-shaped structure light emitting device subsequent to FIG. 85.
87A is a plan view illustrating a process of the method of manufacturing a display device using the rod-shaped structure light emitting element shown in FIG. 86.
FIG. 87B is a cross-sectional view of the display device as viewed from line F27B-F27B in FIG. 87A.
87C is a cross-sectional view of the display device as viewed from a line F27C-F27C in FIG. 87A.
87D is a cross-sectional view of the display device as viewed from the line F27D-F27D in FIG. 87A.
88A is a plan view illustrating a process of the method of manufacturing the display device subsequent to FIGS. 87A to 87D.
88B is a cross-sectional view of the display device as seen from a line F28B-F28B in FIG. 88A.
88C is a cross-sectional view of the display device as viewed from a line F28C to F28C in FIG. 88A.
88D is a cross-sectional view of the display device as viewed from a line F28D-F28D in FIG. 88A.
89A is a plan view illustrating a process of the method of manufacturing the display device subsequent to FIGS. 88A to 88D.
89B is a cross-sectional view of the display device as viewed from the lines F29B-F29B in FIG. 89A.
89C is a cross-sectional view of the display device as viewed from a line F29C-F29C in FIG. 89A.
FIG. 89D is a cross-sectional view of the display device as viewed from the line F29D-F29D in FIG. 89A.
90A is a plan view illustrating a process of the method of manufacturing the display device subsequent to FIGS. 89A to 89D.
90B is a cross-sectional view of the display device as viewed from a line F30B-F30B in FIG. 90A.
90C is a cross-sectional view of the display device as viewed from a line F30C-F30C in FIG. 90A.
90D is a cross-sectional view of the display device as viewed from a line F30D-F30D in FIG. 90A.
91A is a plan view illustrating a process of the method of manufacturing the display device subsequent to FIGS. 90A to 90D.
FIG. 91B is a cross-sectional view of the display device as viewed from the lines F31B-F31B in FIG. 91A.
FIG. 91C is a cross-sectional view of the display device as viewed from a line F31C-F31C in FIG. 91A.
FIG. 91D is a cross-sectional view of the display device as viewed from a line F31D-F31D in FIG. 91A.
92A is a plan view illustrating a process of the method of manufacturing the display device subsequent to FIGS. 91A to 91D.
FIG. 92B is a cross-sectional view of the display device as viewed from the lines F32B-F32B in FIG. 92A.
FIG. 92C is a cross-sectional view of the display device as seen from a line F32C-E32C in FIG. 92A.
FIG. 92D is a cross-sectional view of the display device as viewed from the lines F32D-F32D in FIG. 92A.
93A is a plan view illustrating a process of the method of manufacturing the display device subsequent to FIGS. 92A to 92D.
FIG. 93B is a cross-sectional view of the display device as viewed from a line F33B-F33B in FIG. 93A.
FIG. 93C is a cross-sectional view of the display device as viewed from a line F33C-F33C in FIG. 93A.
FIG. 93D is a cross-sectional view of the display device as viewed from the line F33D-F33D in FIG. 93A.
94A is a plan view illustrating a process of the method of manufacturing the display device subsequent to FIGS. 93A to 93D.
94B is a cross-sectional view of the display device as viewed from a line F34B-F34B in FIG. 94A.
94C is a cross-sectional view of the display device as viewed from a line F34C-F34C in FIG. 94A.
94D is a cross-sectional view of the display device as viewed from a line F34D-F34D in FIG. 94A.
It is a schematic cross section of the rod-shaped structure light emitting element of the 36th embodiment of the present invention.
96A is a flowchart of the method of manufacturing the rod-shaped structure light emitting device of the 36th embodiment.
96B is a flowchart of the method of manufacturing the rod-shaped structure light emitting device of the 36th embodiment.
96C is a flowchart of the method of manufacturing the rod-shaped structure light emitting device of the 36th embodiment.
FIG. 96D is a process chart of the manufacturing method of the rod-shaped structure light emitting device of the 36th embodiment. FIG.
96E is a flowchart of the method of manufacturing the rod-shaped structure light emitting device of the 36th embodiment.
96F is a flowchart of the method of manufacturing the rod-shaped structure light emitting device of the 36th embodiment.
FIG. 96G is a flowchart of the method of manufacturing the rod-shaped structure light emitting device of the 36th embodiment. FIG.
FIG. 96H is a flowchart of the method of manufacturing the rod-shaped structure light emitting device of the 36th embodiment. FIG.
Fig. 96I is a process chart of the manufacturing method of the rod-shaped structure light emitting device of the 36th embodiment.
96J is a flowchart of the method of manufacturing the rod-shaped structure light emitting device of the 36th embodiment.
FIG. 96K is a flowchart of the method of manufacturing the rod-shaped structure light emitting device of the 36th embodiment. FIG.
FIG. 97: is a schematic cross section of the rod-shaped structure light emitting element of 37th Embodiment of this invention.
98A is a flowchart of the method of manufacturing the rod-shaped structure light emitting device of the 37th embodiment.
98B is a flowchart of the method of manufacturing the rod-shaped structure light emitting device of the 37th embodiment.
98C is a flowchart of the method of manufacturing the rod-shaped structure light emitting device of the 37th embodiment.
FIG. 98D is a flowchart of the manufacturing method of the rod-shaped structure light emitting device of the 37th embodiment. FIG.
FIG. 98E is a flowchart of the manufacturing method of the rod-shaped structure light emitting device of the 37th embodiment. FIG.
98F is a flowchart of the method of manufacturing the rod-shaped structure light emitting device of the 37th embodiment.
FIG. 98G is a flowchart of the method of manufacturing the rod-shaped structure light emitting device of the 37th embodiment. FIG.
98H is a flowchart of the method of manufacturing the rod-shaped structure light emitting device of the 37th embodiment.
98I is a flowchart of the method of manufacturing the rod-shaped structure light emitting device of the 37th embodiment.
98J is a process chart of the manufacturing method of the rod-shaped structure light emitting device of the 37th embodiment.
It is process drawing of the manufacturing method of the rod-shaped structure light emitting element of the 37th embodiment.
98L is a flowchart of the method of manufacturing the rod-shaped structure light emitting device of the 37th embodiment.
98m is a flowchart of the method of manufacturing the rod-shaped structure light emitting device of the 37th embodiment.
It is a top view of the insulated substrate used for the backlight, the illuminating device, and the display apparatus provided with the rod-shaped structure light emitting element of 38th Embodiment of this invention.
FIG. 100: is a schematic cross section seen by the arrow 100-100 of FIG.
FIG. 101 is a view for explaining the principle of arranging the rod-shaped structure light emitting elements according to the third embodiment. FIG.
FIG. 102 is a view for explaining a potential applied to an electrode when the rod-shaped structure light emitting elements according to the third embodiment are arranged. FIG.
Fig. 103 is a plan view of an insulating substrate on which the rod-shaped structure light emitting elements of the third embodiment are arranged.
104 is a plan view of the display device.
105 is a circuit diagram of essential parts of a display unit of the display device;
Fig. 106 is a perspective view of a light emitting device of the 39th embodiment of the present invention.
107 is a perspective view of a light emitting device of a 40th embodiment of the present invention.
108 is a perspective view of a light emitting device of a forty-first embodiment of the present invention.
109 is a perspective view of a light emitting device of a 42nd embodiment of the present invention;
110 is a side view of the light-emitting device of the 43rd embodiment of the present invention.
111 is a side view of a light emitting device of a forty-fourth embodiment of the present invention;
112 is a cross-sectional view of the light emitting device.
113 is a sectional view of another example of the above light emitting device.
114 is a sectional view of another example of the above light emitting device.
Fig. 115 is a side view of the light emitting device of the 45th embodiment of the present invention.
116 is a perspective view of the light emitting device.
117 is a plan view of an insulating substrate of a light emitting device used for a backlight, a lighting device, and a display device;
FIG. 118 is a schematic sectional view seen from the line 118-118 of FIG. 117.
119 is a view for explaining the principle of arranging the rod-shaped structure light emitting elements.
It is a figure explaining the potential applied to an electrode when arranging the rod-shaped structure light emitting elements.
121 is a plan view of an insulating substrate on which the rod-shaped light emitting elements are arranged.
122 is a plan view of the display device.
123 is a circuit diagram of main parts of a display unit of the display device;
124 is a plan view of a light emitting device of a forty-sixth embodiment of the present invention;
125 is a perspective view of the light emitting device.
126 is a plan view of a main portion in which the adjacent rod-shaped light emitting elements are in a reverse state in the above light emitting device;

EMBODIMENT OF THE INVENTION Hereinafter, the rod-shaped structure light emitting element of this invention, the manufacturing method of a rod-shaped structure light emitting element, a backlight, an illuminating device, and a display device are demonstrated in detail by embodiment of illustration. In this embodiment, the first conductivity type is n-type and the second conductivity type is p-type, but the first conductivity type may be p-type and the second conductivity type may be n-type.

[First Embodiment]

1: shows the perspective view of the rod-shaped structure light emitting element of 1st Embodiment of this invention. As shown in FIG. 1, the rod-shaped structure light emitting device of the first embodiment is formed so as to cover a portion of the semiconductor core 11 and the semiconductor core 11 made of rod-shaped n-type GaN having a substantially circular cross section. A semiconductor layer 12 made of p-type GaN is provided. The semiconductor core 11 is provided with an exposed portion 11a through which an outer circumferential surface of one end side is exposed. In addition, the end surface of the other end side of the semiconductor core 11 is covered with the semiconductor layer 12.

The rod-shaped structure light emitting device is manufactured as follows.

First, a mask having growth holes is formed on a substrate made of n-type GaN. As the mask, a material that can be selectively etched into the semiconductor core 11 and the semiconductor layer 12, such as silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ), is used. Formation of a growth hole can use the well-known lithography method and the dry etching method used for a normal semiconductor process.

Subsequently, n-type GaN is crystal-grown on a substrate exposed by a growth hole of a mask using a MOCVD (Metal Organic Chemical Vapor Deposition) device to form a rod-shaped semiconductor core 11. The temperature of the MOCVD apparatus is set at about 950 ° C., trimethylgallium (TMG) and ammonia (NH ₃ ) are used as growth gases, silane (SiH ₃ ) is used for n-type impurity supply, and hydrogen (H _{3 is used} as a carrier gas. ), An n-type GaN semiconductor core containing Si as an impurity can be grown. At this time, the diameter of the growing semiconductor core 11 can be determined by the diameter of the growth hole of the mask.

Subsequently, a semiconductor layer made of p-type GaN is formed on the entire surface of the substrate so as to cover the rod-shaped semiconductor core 11. The temperature of the MOCVD apparatus was set to about 960 ° C, and trimethylgallium (TMG) and ammonia (NH ₃ ) were used as the growth gases, and biscyclopentadienyl magnesium (Cp ₂ Mg) was used to supply p-type impurities. P-type GaN can be grown as an impurity.

Subsequently, the lift-off removes the area | region except the part which covers a semiconductor core, and mask, and exposes the board | substrate side outer peripheral surface of the rod-shaped semiconductor core 11, and forms the exposed part 11a. In this state, the end surface of the side opposite to the substrate of the semiconductor core 11 is covered by the semiconductor layer 12. When the mask is made of silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ )), by using a solution containing hydrofluoric acid (HF), the semiconductor core and the portion of the semiconductor layer covering the semiconductor core are easily affected. The mask can be etched without any knowledge, and the semiconductor layer (region except for the portion of the semiconductor layer covering the semiconductor core) on the mask can be removed by lift-off together with the mask. In this embodiment, the length of the exposed portion 11a of the semiconductor core 11 is determined by the film thickness of the removed mask. Although the lift-off was used in the exposure process of this embodiment, you may expose a part of semiconductor core by etching.

Subsequently, the source close to the substrate side of the semiconductor core 11 standing up on the substrate is bent by immersing the substrate in an isopropyl alcohol (IPA) aqueous solution and vibrating the substrate along the substrate plane using ultrasonic waves (for example, several tens of microseconds). Stress is applied to the semiconductor core 11 covered with the semiconductor layer 12 so that the semiconductor core 11 covered with the semiconductor layer 12 is separated from the substrate.

In this way, a fine rod-shaped structure light emitting element separated from the substrate made of n-type GaN can be manufactured.

In the rod-shaped light emitting device, the semiconductor layer 12 crystal grows outward from the outer circumferential surface of the semiconductor core 11 in the radial direction outward, the growth distance in the radial direction is short, and the defect is avoided outward so that the semiconductor has fewer crystal defects. The semiconductor core 11 may be covered by the layer 12. Therefore, a rod-shaped structure light emitting device having good characteristics can be realized.

According to the rod-shaped structure light emitting device having the above structure, the semiconductor layer 12 made of p-type GaN so as to cover the semiconductor core 11 made of the rod-shaped n-type GaN and to expose the outer peripheral surface of a part of the semiconductor core 11 is exposed. By forming the semiconductor layer 12, the exposed semiconductor layer 11 of the semiconductor core 11 is connected to the n-side electrode and covers the semiconductor core 11, even in the case of a fine rod-shaped light emitting device having a micro order size or a nano order size. The p-side electrode can be connected to the portion of. In the rod-shaped structure light emitting device, the n-side electrode is connected to the exposed portion 11a of the semiconductor core 11 and the p-side electrode is connected to the semiconductor layer 12 so that the outer circumferential surface of the semiconductor core 11 and the semiconductor layer 12 are connected. Light is emitted from the pn junction by flowing a current from the p-side electrode to the n-side electrode so that recombination of electrons and holes occurs at the pn junction of the inner circumferential surface of. In the rod-shaped light emitting device, light is emitted from the entire circumference of the semiconductor core 11 covered with the semiconductor layer 12, so that the light emitting area is widened, so that the light emitting efficiency is high. Therefore, a fine rod-shaped light emitting device having a high luminous efficiency that can be easily connected to electrodes with a simple configuration can be realized. In addition, since the rod-shaped structure light emitting device is not integral with the substrate, the degree of freedom in mounting to the device is high.

Here, the fine rod-shaped light emitting device is, for example, a micro-order size having a diameter of 1 µm and a length of 10 µm to 30 µm, or a nano-order size having at least a diameter of less than 1 µm in diameter or length. In addition, the rod-shaped structured light emitting device can reduce the amount of semiconductor used, and it is possible to reduce the thickness and weight of the device using the light emitting device, and to realize a high luminous efficiency and a power saving backlight, lighting device, display device, and the like. Can be.

In addition, one electrode is exposed to the exposed portion 11a of the outer circumferential surface of the one end side of the semiconductor core 11 by exposing the outer circumferential surface of the one end side of the semiconductor core 11 about 1 µm to 5 µm, for example. It is possible to connect the electrodes to the semiconductor layer 12 on the other end side of the semiconductor core 11, and to connect the electrodes by separating the electrodes at both ends, and to connect the electrodes to the semiconductor layer 12 and the semiconductor core 11. The short-circuited portion of the exposed portion of the can be easily prevented.

In addition, the part of the semiconductor layer 12 which covers the end surface of the side opposite to the exposed part 11a of the semiconductor core 11 by covering the end surface of the other end side of the said semiconductor core 11 with the semiconductor layer 12 is shown. The p-side electrode can be easily connected to the semiconductor core 11 without shorting it. As a result, the electrodes can be easily connected to both ends of the fine rod-shaped light emitting device.

In addition, since the outer circumferential surface of the region covered by the semiconductor layer 12 of the semiconductor core 11 and the outer circumferential surface of the exposed region of the semiconductor core 11 are continuous, the exposed region of the semiconductor core 11 becomes the semiconductor layer 12. Since it is thinner than the outer diameter of, the exposed region of the semiconductor core 11 formed so as to stand on the substrate in the manufacturing process is easily folded on the substrate side, thereby facilitating manufacture.

[2nd Embodiment]

2 is a perspective view of a rod-shaped structure light emitting device according to a second embodiment of the present invention. As shown in FIG. 2, the rod-shaped structure light emitting device of the second embodiment is formed so as to cover a portion of the semiconductor core 21 and the semiconductor core 21 made of rod-shaped n-type GaN having a substantially circular cross section. A quantum well layer 22 made of p-type InGaN and a semiconductor layer 23 made of p-type GaN formed to cover the quantum well layer 22 are provided. The semiconductor core 21 is provided with an exposed portion 21a through which an outer circumferential surface of one end thereof is exposed. The end surface of the other end side of the semiconductor core 21 is covered with the quantum well layer 22 and the semiconductor layer 23.

In the rod-shaped structure light emitting device of the second embodiment, like the rod-shaped structure light emitting device of the first embodiment, the rod-shaped semiconductor core is grown by growing n-type GaN on a substrate made of n-type GaN using a MOCVD apparatus. 21 is formed.

The rod-shaped structure light emitting element of the second embodiment has the same effect as the rod-shaped structure light emitting element of the first embodiment.

In addition, by forming the quantum well layer 22 between the semiconductor core 21 and the semiconductor layer 23, the luminous efficiency may be further improved by the quantum confinement effect of the quantum well layer 22. After growing the semiconductor core of n-type GaN as described above in the MOCVD apparatus, the set temperature was changed from 600 ° C. to 800 ° C. according to the emission wavelength, nitrogen (N ₂ ) in the carrier gas, TMG and NH in the growth gas. By supplying ₃ , trimethylindium (TMI), the InGaN quantum well layer 22 can be formed on the n-type GaN semiconductor core 21. Thereafter, the set temperature is 960 ° C, and as described above, TMG and NH ₃ are used as growth gases, and Cp ₂ Mg is used for p-type impurity supply, thereby making the semiconductor layer 23 made of p-type GaN. Can be formed. In addition, the quantum well layer may have a p-type AlGaN layer as an electron block layer between the InGaN layer and the p-type GaN layer, and a multi-quantum well structure in which GaN barrier layers and InGaN quantum well layers are alternately stacked. Also good.

[Third Embodiment]

3 is a perspective view of a rod-shaped structure light emitting device according to a third embodiment of the present invention. As shown in FIG. 3, the rod-shaped structure light emitting device of this third embodiment is formed so as to cover a portion of the semiconductor core 11 and a semiconductor core 11 made of rod-shaped n-type GaN having a substantially circular cross section. A semiconductor layer 12 made of p-type GaN and a transparent electrode 13 formed to cover the semiconductor layer 12 are provided. The semiconductor core 11 is provided with an exposed portion 11a through which an outer circumferential surface of one end side is exposed. In addition, the end surface of the other end side of the semiconductor core 11 is covered with the semiconductor layer 12 and the transparent electrode 13. The transparent electrode 13 is formed of ITO (tin-added indium oxide) having a thickness of 200 nm. ITO film formation can use a vapor deposition method or a sputtering method. After the ITO film is formed, the heat resistance is performed at 500 ° C. to 600 ° C. to reduce the contact resistance of the semiconductor layer 12 made of p-type GaN and the transparent electrode 13 made of ITO. In addition, a transparent electrode is not limited to this, For example, the laminated metal film of Ag / Ni of thickness 5nm, etc. may be used. Vapor deposition or sputtering can be used for the film formation. In order to lower the resistance of the electrode layer, a laminated metal film of Ag / Ni may be laminated on the ITO film.

In the rod-shaped structure light emitting device of the third embodiment, like the rod-shaped structure light emitting device of the first embodiment, a rod-shaped semiconductor core is formed by growing n-type GaN on a substrate made of n-type GaN using a MOCVD apparatus. (11) is formed.

The rod-shaped structure light emitting element of the third embodiment has the same effect as the rod-shaped structure light emitting element of the first embodiment.

In addition, by forming the transparent electrode 13 to cover approximately the entirety of the semiconductor layer 12, the semiconductor layer 12 is connected to the electrode through the transparent electrode 13, so that current concentrates and biases the electrode connection portion. Without this, a wide current path can be formed to emit the entire device, thereby further improving luminous efficiency. Particularly, in the structure of the semiconductor core composed of the n-type semiconductor and the semiconductor layer composed of the p-type semiconductor, the semiconductor layer composed of the p-type semiconductor has a high resistance due to difficulty in increasing the impurity concentration, but the entire element is formed by forming a wide current path by the transparent electrode. Can be emitted to further improve luminous efficiency.

[Fourth Embodiment]

4 is a perspective view of a rod-shaped structure light emitting device according to a fourth embodiment of the present invention. As shown in FIG. 4, the rod-shaped structure light emitting device of this fourth embodiment is formed so as to cover a portion of the semiconductor core 21 and the semiconductor core 21 made of rod-shaped n-type GaN having a substantially circular cross section. A quantum well layer 22 made of p-type InGaN, a semiconductor layer 23 made of p-type GaN formed to cover the quantum well layer 22, and a transparent electrode 24 formed to cover the semiconductor layer 23. ). The semiconductor core 21 is provided with an exposed portion 21a through which an outer circumferential surface of one end thereof is exposed. 5, the end surface of the other end side of the semiconductor core 21 is covered with the quantum well layer 22, the semiconductor layer 23, and the transparent electrode 24. Thereby, by connecting an electrode (or wiring) to the end of the transparent electrode 24 opposite to the exposed portion 21a of the semiconductor core 21, the short circuit of the electrode and the semiconductor core 21 can be easily prevented. In addition, since the electrode (or wiring) connected to the transparent electrode 24 can be made thicker or larger in cross-sectional area, heat can be efficiently dissipated through the electrode (or wiring).

In addition, in the rod-shaped structure light emitting device, as shown in FIG. 6, the n-side electrode 25 is connected to the exposed portion 21a of the semiconductor core 21, and the p-side is connected to the transparent electrode 24 on the other end side. The electrode 26 is connected. Since the p-side electrode 26 is connected to the end of the transparent electrode 24, the area for blocking the light emitting region with the electrode can be minimized, and the light extraction efficiency can be improved.

In the rod-shaped structure light emitting device of the fourth embodiment, like the rod-shaped light emitting device of the first embodiment, n-type GaN is crystal-grown on a substrate made of n-type GaN using a MOCVD apparatus to form rod-shaped semiconductor cores. 21 is formed.

The rod-shaped structure light emitting element of the fourth embodiment has the same effect as the rod-shaped structure light emitting element of the second embodiment.

In addition, by forming the transparent electrode 24 so as to cover substantially the entirety of the semiconductor layer 23, the semiconductor layer 23 is connected to the p-side electrode 26 through the transparent electrode 24 to the electrode connection portion. It is possible to form a wide current path to emit light of the whole element without concentrating the current to concentrate, thereby further improving luminous efficiency. Particularly, in the structure of the semiconductor core composed of the n-type semiconductor and the semiconductor layer composed of the p-type semiconductor, the semiconductor layer composed of the p-type semiconductor has a high resistance due to difficulty in increasing the impurity concentration, but the entire element is formed by forming a wide current path by the transparent electrode. Can be emitted to further improve luminous efficiency.

In the first to fourth embodiments, n-type GaN doped with Si and p-type GaN doped with Mg are used, but impurities doped into GaN are not limited thereto. Ge may be used in the n-type, and Zn may be used in the p-type.

Further, in the first to fourth embodiments, the rod-shaped structure light emitting device in which the semiconductor layer or the quantum well layer is coated on the rod-shaped semiconductor cores 11 and 21 having a substantially circular cross section has been described. You may apply this invention to the rod-shaped structure light emitting element which coat | covered the semiconductor layer, the quantum well layer, etc. on the rod-shaped semiconductor core which is another polygon. The n-type GaN becomes hexagonal crystal growth, and grows in a c-axis direction perpendicular to the substrate surface to obtain a substantially hexagonal columnar semiconductor core. Although depending on growth conditions such as growth direction and growth temperature, when the diameter of the semiconductor core to be grown is small, about tens of nanometers to several hundreds of nanometers, the cross-section tends to be nearly circular in shape, and the diameter is about 0.5 μm. If the thickness is increased to several micrometers, the cross section may be easily grown in a hexagon.

For example, as shown in FIG. 7, the semiconductor core 31 which consists of rod-shaped n-type GaN of a substantially hexagonal cross section, and the semiconductor layer 32 which consists of p-type GaN formed so that a part of the said semiconductor core 31 may be covered may be formed. Equipped. The semiconductor core 31 is provided with an exposed portion 31a through which an outer circumferential surface of one end thereof is exposed. In addition, the end surface of the other end side of the semiconductor core 31 is covered with the semiconductor layer 32.

8, the semiconductor core 41 which consists of rod-shaped n-type GaN of a substantially hexagonal cross section, the quantum well layer 42 formed so that a part of the said semiconductor core 41 may be covered, and the said quantum well A semiconductor layer 43 made of p-type GaN formed to cover the layer 42 is provided. The semiconductor core 41 is provided with an exposed portion 41a through which an outer peripheral surface of one end is exposed. The end surface of the other end side of the semiconductor core 41 is covered with the quantum well layer 42 and the semiconductor layer 43.

In addition, as shown in Fig. 9, a semiconductor core 31 composed of a rod-shaped n-type GaN having a substantially circular cross section, and a semiconductor layer 32 composed of a p-type GaN formed so as to cover a part of the semiconductor core 31; And a transparent electrode 33 made of ITO formed to cover the semiconductor layer 32. The semiconductor core 31 is provided with an exposed portion 31a through which an outer circumferential surface of one end thereof is exposed. The end face of the other end side of the semiconductor core 31 is covered with the semiconductor layer 32 and the transparent electrode 33.

10, the quantum well layer 42 which consists of the semiconductor core 41 which consists of rod-shaped n-type GaN which has a substantially circular cross section, and the p-type InGaN formed so that a part of the said semiconductor core 41 may be covered is shown. And a semiconductor layer 43 made of p-type GaN formed to cover the quantum well layer 42 and a transparent electrode 44 made of ITO formed to cover the semiconductor layer 43. The semiconductor core 41 is provided with an exposed portion 41a through which an outer peripheral surface of one end is exposed. As shown in FIG. 5, the end surface of the other end side of the semiconductor core 41 is covered with the quantum well layer 42, the semiconductor layer 43, and the transparent electrode 44.

[Fifth Embodiment]

Fig. 11 is a sectional view of a rod-shaped structure light emitting device of a fifth embodiment of the present invention. As shown in FIG. 11, the rod-shaped structure light emitting device of the fifth embodiment is formed so as to cover a portion of the semiconductor core 51 and the semiconductor core 51 made of rod-shaped n-type GaN having a substantially circular cross section. A semiconductor layer 52 made of p-type GaN is provided. The semiconductor core 51 is provided with an exposed portion 51a through which an outer circumferential surface of one end thereof is exposed. The end surface of the other end side of the semiconductor core 51 is covered with the semiconductor layer 52.

The thickness of the semiconductor layer 52 in the axial direction of the portion 52a covering the end surface of the other end side of the semiconductor core 51 is thicker than the thickness in the radial direction of the portion 52b covering the outer circumferential surface of the semiconductor core 51. Formed.

FIG. 12: is a cross-sectional schematic diagram of the principal part of the said rod-shaped structure light emitting element, Comprising: A semiconductor core (rather than the thickness T1 of radial direction of the part 52b which covers the outer peripheral surface of the semiconductor core 51 in the semiconductor layer 52) The thickness T2 of the axial direction of the part 52a which covers the end surface of the other end side of 51 is thick.

As a result, the electrode 53 connected to the semiconductor layer 52 side covering the end surface of the other end side of the semiconductor core 51 can be connected to the semiconductor layer 52 without overlapping the semiconductor core 51. The extraction efficiency of the light of the whole side surface of the semiconductor core 51 can be improved. Alternatively, the overlap amount can be reduced even when the electrode 53 connected to the semiconductor layer 52 side covering the end surface of the other end side of the semiconductor core 51 overlaps with the semiconductor core 51, so that the light extraction efficiency can be improved. Can be improved. In addition, the semiconductor layer 52 has an axial direction of the portion 52a that covers the end surface of the other end side of the semiconductor core 51 than the thickness T1 in the radial direction of the portion 52b that covers the outer circumferential surface of the semiconductor core 51. Since the thickness T2 is thick, the resistance of the portion 52a of the semiconductor layer 52 covering the end surface of the other end side of the semiconductor core 51 becomes high, so that light emission does not concentrate on the other end side of the semiconductor core 51 and thus the semiconductor The light emission of the side region of the core 51 can be enhanced, and the leakage current in the portion 52a of the semiconductor layer 52 covering the end surface of the other end side of the semiconductor core 51 can be suppressed.

On the other hand, as shown, for example, in the cross-sectional schematic diagram of the principal part of the rod-shaped structure light emitting element of the comparative example of FIG. 13, the semiconductor layer 1052 has a radial direction of a portion 1052b covering the outer circumferential surface of the semiconductor core 1051. When the thickness T11 and the thickness T12 in the axial direction of the portion 1052a covering the end surface on the other end side of the semiconductor core 1051 are approximately the same thickness, light emission concentrates on the other end side of the semiconductor core 1051. There is a possibility that light emission in the side region of the semiconductor core 1051 is lowered or a leakage current is generated in the portion 1052a of the semiconductor layer 1052 covering the end surface of the other end side of the semiconductor core 1051. In addition, since the electrode 1053 greatly overlaps the semiconductor core 1051, light extraction efficiency is lowered.

The rod-shaped structure light emitting element of the fifth embodiment has the same effect as the rod-shaped structure light emitting element of the first embodiment.

[Sixth Embodiment]

14 is a sectional view of a rod-shaped structure light emitting device of a sixth embodiment of the present invention. As shown in FIG. 2, the rod-shaped structure light emitting device of the sixth embodiment is formed so as to cover a portion of the semiconductor core 61 and the semiconductor core 61 made of rod-shaped n-type GaN having a substantially circular cross section. A quantum well layer 62 made of p-type InGaN and a semiconductor layer 63 made of p-type GaN formed to cover the quantum well layer 62 are provided. The semiconductor core 61 has an exposed portion 61a through which an outer circumferential surface of one end side thereof is exposed. The end surface of the other end side of the semiconductor core 61 is covered with the quantum well layer 62 and the semiconductor layer 63.

The quantum well layer 62 is thicker in the axial direction of the portion 62a covering the end surface of the other end side of the semiconductor core 61 than the thickness in the radial direction of the portion 62b covering the outer circumferential surface of the semiconductor core 61. It is formed to

FIG. 15 is a schematic cross-sectional view of the main portion of the rod-shaped light emitting device, and is larger than the thickness T21 in the radial direction of the portion 62b of the quantum well layer 62 that covers the outer circumferential surface of the semiconductor core 61. The thickness T22 of the axial direction of the part 62a which covers the end surface of the other end side of 61 is thick.

Thereby, the electrode 64 connected to the semiconductor layer 63 side which covers the end surface of the other end side of the semiconductor core 61 can be connected to the semiconductor layer 63, without overlapping with the semiconductor core 61, and a semiconductor The extraction efficiency of the light of the whole side surface of the core 61 can be improved. Alternatively, the overlap amount can be reduced even when the electrode 64 connected to the semiconductor layer 63 side covering the end surface of the other end side of the semiconductor core 61 overlaps with the semiconductor core 61, so that the light extraction efficiency can be reduced. Can be improved. In addition, the quantum well layer 62 has an axis of the portion 62a that covers the end surface of the other end side of the semiconductor core 61 rather than the thickness T21 in the radial direction of the portion 62b that covers the outer circumferential surface of the semiconductor core 61. Since the thickness T22 in the direction is thick, the electric field concentration generated at the corner portion of the other end side of the semiconductor core 61 can be alleviated, the breakdown voltage can be improved, and the life of the light emitting device can be improved. The leakage current in the part 62a of the quantum well layer 62 which covers the end surface of the other end side of () can be suppressed.

On the other hand, for example, as shown in the cross-sectional schematic diagram of the main portion of the rod-shaped structure light emitting device of the comparative example of FIG. 16, the radial direction of the portion 1062b of the quantum well layer 1062 covering the outer circumferential surface of the semiconductor core 1061. Corner portion on the other end side of the semiconductor core 61 when the thickness T31 of the semiconductor core 1051 and the thickness T32 in the axial direction of the portion 1052a covering the end surface on the other end side of the semiconductor core 1051 are substantially the same thickness. There is a possibility that electric field concentration may cause the breakdown voltage to drop, or a leakage current may be generated in the part 1062a of the quantum well layer 1062 covering the end surface of the other end side of the semiconductor core 1061. In addition, since the electrode 1064 greatly overlaps the semiconductor core 1061, light extraction efficiency is lowered.

The rod-shaped structure light emitting element of the sixth embodiment has the same effect as the rod-shaped structure light emitting element of the first embodiment.

[Seventh Embodiment]

17A to 17E show process drawings of a method for manufacturing a rod-shaped structure light emitting device according to a seventh embodiment of the present invention. In this embodiment, n-type GaN doped with Si and p-type GaN doped with Mg are used, but impurities doped in GaN are not limited thereto.

First, as shown in FIG. 17A, an island-shaped catalyst metal layer 75 is formed on a substrate 70 made of n-type GaN (catalyst metal layer forming step). As the catalyst metal layer, materials such as Ni, Fe, Au, etc., which are obtained by dissolving them in compound semiconductor materials such as Ga, N, In, and Al, and impurity materials such as Si and Mg, and which are difficult to form compounds with themselves are used. Can be. Formation of an island pattern is performed by forming a catalyst metal layer on the substrate 70 with a thickness of about 100 nm to 300 nm, and then forming an island in an island shape having a diameter of about 1 μm to grow a semiconductor core by lithography and dry etching. Leave and pattern.

Next, as shown in FIG. 17B, the island-shaped catalyst metal layer 75 is formed on a substrate 70 on which the island-shaped catalyst metal layer 75 is formed by using a MOCVD (Metal Organic Chemical Vapor Deposition) device. N-type GaN is crystal-grown from the interface between the substrate and the substrate 70 to form a semiconductor core 71 made of rod-shaped n-type GaN (semiconductor core forming step). The growth temperature is set at about 800 ° C., trimethylgallium (TMG) and ammonia (NH ₃ ) are used as growth gases, silane (SiH ₄ ) is used for n-type impurity supply, and hydrogen (H ₂ ) is used as a carrier gas. By supplying, the n-type GaN semiconductor core 71 made of Si can be grown. Here, the n-type GaN becomes hexagonal crystal growth, and a hexagonal pillar-shaped semiconductor core is obtained by growing with the c-axis direction perpendicular to the surface of the substrate 70.

Next, as shown in FIG. 17C, the outer circumferential surface of the semiconductor core 71 and the catalyst metal layer 75 and the semiconductor core 71 are held in a state where the island-like catalyst metal layer 75 is held at the tip of the semiconductor core 71. Crystal growth from the interface forms a semiconductor layer 72 made of p-type GaN covering the surface of the semiconductor core 71 (semiconductor layer forming step). In this semiconductor layer formation step, the formation temperature is set to about 900 ° C., and trimethylgallium (TMG) and ammonia (NH ₃ ) are used as growth gases, and biscyclopentadienyl magnesium (Cp ₂ Mg) is used for p-type impurity supply. As a result, p-type GaN containing magnesium (Mg) as an impurity can be grown.

Next, as shown in FIG. 17D, the outer peripheral surface of the substrate 70 of the semiconductor core 71 is exposed by dry etching (exposure step). At this time, the island-shaped catalyst metal layer 75 is removed and a part of the upper end of the semiconductor core 71 is removed, but the radial direction of the portion 72b of the semiconductor layer 72 covering the outer circumferential surface of the semiconductor core 71 is removed. The thickness in the axial direction of the portion 72a covering the end surface of the other end side of the semiconductor core 71 is thicker than the thickness of. In this exposure process, SiCl ₄ can be easily etched with GaN by using SiCl ₄ for RIE (reactive ion etching) of dry etching.

Subsequently, in the separation step, the semiconductor core is placed on the substrate 70 by immersing the substrate in an isopropyl alcohol (IPA) aqueous solution and vibrating the substrate 70 along the substrate plane using ultrasonic waves (for example, several tens of microseconds). A stress acts on the semiconductor core 71 covered with the semiconductor layer 72 so that the source close to the substrate 70 side of the 71 is bent, and as shown in FIG. 17E, the semiconductor covered with the semiconductor layer 72. The core 71 is separated from the substrate 70.

In this way, a fine rod-shaped light emitting device separated from the substrate 70 can be manufactured. In this seventh embodiment, the rod-shaped structure light emitting element has a diameter of 1 μm and a length of 10 μm (the length of the rod-shaped structure light emitting element is shortened in FIGS. 17A to 17E to make the drawing easy to see).

In addition, the rod-shaped structure light emitting device is a semiconductor having fewer crystal defects because the semiconductor layer 72 crystal grows radially outward from the outer circumferential surface of the semiconductor core 71, the growth distance in the radial direction is short, and defects are avoided outward. The layer 72 may cover the semiconductor core 71. Therefore, a rod-shaped structure light emitting device having good characteristics can be realized.

In this manner, in the rod-shaped structure light emitting device separated from the substrate 70, one electrode is connected to the exposed portion 71a of the semiconductor core 71, and the other electrode is connected to the semiconductor layer 72 so that the semiconductor core ( Light is emitted from the pn junction by flowing a current between the electrodes so that recombination of electrons and holes occurs at the pn junction between the outer circumferential surface of 71 and the inner circumferential surface of the semiconductor layer 72.

P covering the surface of the semiconductor core 71 in a state where the island-like catalyst metal layer 75 is held at the tip of the semiconductor core 71 without removing the island-like catalyst metal layer 75 in the semiconductor layer forming step. Forming the semiconductor layer 72 of the type promotes crystal growth from the interface between the catalyst metal layer 75 and the semiconductor core 71 rather than the outer circumferential surface of the semiconductor core 71, so that a portion 72b covering the outer circumferential surface of the semiconductor core 71 is formed. It is possible to easily form the semiconductor layer 72 whose thickness in the axial direction of the portion 72a that covers the end surface of the other end side of the semiconductor core 71 is greater than the thickness in the radial direction.

According to the method for producing a rod-shaped structure light emitting device, it is possible to manufacture a fine rod-shaped structure light emitting device having a high degree of freedom in mounting to an apparatus. Here, the fine rod-shaped light emitting device is, for example, a micro order size having a diameter of 1 μm and a length of 10 μm, or a nano order size having at least a diameter of less than 1 μm in diameter or length. In addition, the rod-shaped structured light emitting device can reduce the amount of semiconductor used, and it is possible to reduce the thickness and weight of the device using the light emitting device and to emit light from the entire circumference of the semiconductor core covered with the semiconductor layer. Since the light emitting area is wider, a high luminous efficiency and a power saving backlight, lighting device, display device, and the like can be realized.

In addition, the semiconductor core is formed while the island-like catalyst metal layer 75 is held at the tip of the semiconductor core 71 without removing the island-like catalyst metal layer 75 before the semiconductor layer forming step of forming the semiconductor layer 72. A quantum well layer may be formed so as to cover the surface of (71). Thereby, the quantum well layer which is thicker in the axial direction of the part which covers the end surface of the other end side of a semiconductor core than the thickness of the radial direction of the part which covers the outer peripheral surface of a semiconductor core can be formed easily.

The rod-shaped structure light emitting element of the seventh embodiment has the same effect as the rod-shaped structure light emitting element of the fifth embodiment.

Moreover, the thickness of the axial direction of the part 72a which covers the end surface of the other end side of the semiconductor core 71 rather than the thickness of the radial direction of the part 72b which covers the outer peripheral surface of the semiconductor core 71 in the said semiconductor layer 72. Of the semiconductor layer 72 without thickening the electrode connecting to the semiconductor layer 72 side covering the end surface of the other end side of the semiconductor core 71 to the position of the end surface of the other end side of the semiconductor core 71 Since it can connect only to 72a), the extraction efficiency of the light of the whole side surface of the semiconductor core 71 can be improved. In addition, the thickness of the semiconductor layer 72 in the axial direction of the portion 72a covering the end surface of the other end side of the semiconductor core 71 is greater than the thickness in the radial direction of the portion 72b covering the outer circumferential surface of the semiconductor core 71. Since it is thick, the resistance of the part 72a of the semiconductor layer 72 which covers the end surface of the other end side of the semiconductor core 71 becomes high, and light emission does not concentrate on the other end side of the semiconductor core 71, but the side surface of the semiconductor core 71 The light emission of the region can be enhanced, and the leakage current in the portion 72a of the semiconductor layer 72 covering the end surface of the other end side of the semiconductor core 71 can be suppressed.

[Eighth Embodiment]

18A to 18D show process drawings of a method for manufacturing a rod-shaped structure light emitting device according to an eighth embodiment of the present invention. In this embodiment, n-type GaN doped with Si and p-type GaN doped with Mg are used, but impurities doped in GaN are not limited thereto.

First, as shown in FIG. 18A, a semiconductor film 84 made of n-type GaN is formed on a base substrate 80, and an island-shaped catalyst metal layer 85 is formed on the semiconductor film 84 ( Catalytic metal layer forming process). As the catalyst metal layer, materials such as Ni, Fe, Au, etc., which are obtained by dissolving them in compound semiconductor materials such as Ga, N, In, and Al, and impurity materials such as Si and Mg, and which are difficult to form compounds with themselves are used. Can be. The island-shaped pattern is formed by forming a catalyst metal layer on the semiconductor film 84 in a thickness of about 100 nm to 300 nm, and then forming an island-shaped island having a diameter of about 1 μm to grow the semiconductor core by lithography and dry etching. And pattern it.

Next, as shown in FIG. 18B, n is used from the interface between the island-shaped catalyst metal layer 85 and the semiconductor film 84 using the MOCVD apparatus on the semiconductor film 84 on which the island-shaped catalyst metal layer 85 is formed. Crystal growth of GaN of a type | mold forms the semiconductor core 81 which consists of rod-shaped n-type GaN (semiconductor core formation process). The growth temperature is set at about 800 ° C., trimethylgallium (TMG) and ammonia (NH ₃ ) are used as growth gases, silane (SiH ₄ ) is used for n-type impurity supply, and hydrogen (H ₂ ) is used as a carrier gas. By supplying, the n-type GaN semiconductor core 81 made of Si can be grown. Here, the n-type GaN becomes hexagonal crystal growth, and a hexagonal pillar-shaped semiconductor core is obtained by growing in a c-axis direction perpendicular to the surface of the semiconductor film 84.

Next, as shown in FIG. 18C, the outer circumferential surface of the semiconductor core 81 and the catalyst metal layer 85 and the semiconductor core 81 of the semiconductor core 81 are held in the state where the island-shaped catalyst metal layer 85 is held at the tip of the semiconductor core 81. The p-type semiconductor layer 82 covering the surface of the semiconductor core 81 is formed by crystal growth from the interface (semiconductor core forming step). In this semiconductor layer formation step, the formation temperature is set to about 900 ° C., and trimethylgallium (TMG) and ammonia (NH ₃ ) are used as growth gases, and biscyclopentadienyl magnesium (Cp ₂ Mg) is used for p-type impurity supply. As a result, p-type GaN containing magnesium (Mg) as an impurity can be grown.

18D, the surface of the base substrate 80 and the outer peripheral surface of the base substrate 80 of the semiconductor core 81 are exposed by dry etching (exposure process). At this time, the island-shaped catalyst metal layer 85 is removed and a part of the upper end of the semiconductor core 81 is removed, but the radial direction of the portion 82b of the semiconductor layer 82 covering the outer circumferential surface of the semiconductor core 81 is removed. The thickness in the axial direction of the portion 82a covering the end surface of the other end side of the semiconductor core 81 is thicker than the thickness of. In this exposure step, by using SiCl ₄ for the RIE of dry etching, etching can be easily performed with anisotropy in GaN.

Subsequently, in the separation step, the semiconductor is immersed in an isopropyl alcohol (IPA) aqueous solution, and is mounted on the underlying substrate 80 by vibrating the underlying substrate 80 along the substrate plane using ultrasonic waves (for example, several tens of microseconds). A stress acts on the semiconductor core 81 covered with the semiconductor layer 82 so that the source close to the base substrate 80 side of the core 81 is bent, and as shown in FIG. 18E, the semiconductor layer 82 is transferred to the semiconductor layer 82. The covered semiconductor core 81 is separated from the underlying substrate 80.

In this way, a fine rod-shaped light emitting device separated from the base substrate 80 can be manufactured. In this eighth embodiment, the rod-shaped light emitting device has a diameter of 1 占 퐉 and a length of 10 占 퐉 (the length of the rod-shaped light emitting device is shortened in FIGS. 18A to 18E to make the drawing easier to see).

In addition, the rod-shaped structure light emitting device is a semiconductor having fewer crystal defects because the semiconductor layer 82 crystal grows radially outward from the outer circumferential surface of the semiconductor core 81, the growth distance in the radial direction is short and defects are avoided outward. The semiconductor core 81 may be covered by the layer 82. Therefore, a rod-shaped structure light emitting device having good characteristics can be realized.

In this manner, in the rod-shaped structure light emitting device separated from the base substrate 80, one electrode is connected to the exposed portion 81a of the semiconductor core 81, and the other electrode is connected to the semiconductor layer 82, thereby providing a semiconductor core. Light is emitted from the pn junction by flowing a current between the electrodes such that electrons and holes are recombined at the pn junction between the outer circumferential surface of 81 and the inner circumferential surface of the semiconductor layer 82.

P covering the surface of the semiconductor core 81 while the island-like catalyst metal layer 85 is held at the tip of the semiconductor core 81 without removing the island-like catalyst metal layer 85 in the semiconductor layer forming step. Formation of the semiconductor layer 82 promotes crystal growth from the interface between the catalyst metal layer 85 and the semiconductor core 81 rather than the outer circumferential surface of the semiconductor core 81, so that the portion 82b covering the outer circumferential surface of the semiconductor core 81 is formed. It is possible to easily form the semiconductor layer 82 whose thickness in the axial direction of the portion 82a covering the end surface of the other end side of the semiconductor core 81 is larger than the thickness in the radial direction of the cross section.

According to the method for producing a rod-shaped structure light emitting device, it is possible to manufacture a fine rod-shaped structure light emitting device having a high degree of freedom in mounting to an apparatus. Here, the fine rod-shaped light emitting device is, for example, a micro order size having a diameter of 1 μm and a length of 10 μm, or a nano order size having at least a diameter of less than 1 μm in diameter or length. In addition, the rod-shaped structured light emitting device can reduce the amount of semiconductor used, and it is possible to reduce the thickness and weight of the device using the light emitting device and to emit light from the entire circumference of the semiconductor core covered with the semiconductor layer. Since the light emitting area is wider, a high luminous efficiency and a power saving backlight, lighting device, display device, and the like can be realized.

In addition, since the outer circumferential surface of the semiconductor layer 82 and the outer circumferential surface of the exposed portion 81a of the semiconductor core 81 are continuous without a step, the fine rod-shaped structure light emitting element after separation is axially mounted on the insulating substrate on which the electrode is formed. When mounting so that the directions become parallel, there is no step between the outer circumferential surface of the semiconductor layer 82 and the outer circumferential surface of the exposed portion 81a of the semiconductor core 81, so that the exposed portion 81a and the electrode of the semiconductor core 81 are secured. And it can be easily connected.

In addition, the semiconductor core is formed while the island-like catalyst metal layer 85 is held at the tip of the semiconductor core 81 without removing the island-like catalyst metal layer 85 before the semiconductor layer forming step of forming the semiconductor layer 82. A quantum well layer may be formed so as to cover the surface of (81). Thereby, the quantum well layer which is thicker in the axial direction of the part which covers the end surface of the other end side of a semiconductor core than the thickness of the radial direction of the part which covers the outer peripheral surface of a semiconductor core can be formed easily.

The rod-shaped structure light emitting element of the eighth embodiment has the same effect as the rod-shaped structure light emitting element of the fifth embodiment.

Moreover, the thickness of the axial direction of the part 82a which covers the end surface of the other end side of the semiconductor core 81 rather than the thickness of the radial direction of the part 82b which covers the outer peripheral surface of the semiconductor core 81 in the said semiconductor layer 82 The thickness of the semiconductor layer 82 without overlapping the electrode connected to the semiconductor layer 82 side covering the end surface of the other end side of the semiconductor core 81 to the position of the end surface of the other end side of the semiconductor core 81 Since it can connect only to 82a, the extraction efficiency of the light of the whole side surface of the semiconductor core 81 can be improved. In addition, the thickness of the semiconductor layer 82 in the axial direction of the portion 82a covering the end surface of the other end side of the semiconductor core 81 is larger than the thickness in the radial direction of the portion 82b covering the outer circumferential surface of the semiconductor core 81. Since it is thick, the resistance of the portion 82a of the semiconductor layer 82 covering the end surface of the other end side of the semiconductor core 81 becomes high, so that light emission does not concentrate on the other end side of the semiconductor core 81 so that the side surface of the semiconductor core 81 The light emission of the region can be enhanced and the leakage current in the portion 82a of the semiconductor layer 82 covering the end surface of the other end side of the semiconductor core 81 can be suppressed.

[Ninth Embodiment]

19A to 19E show process drawings of a method for manufacturing a rod-shaped structure light emitting device according to a ninth embodiment of the present invention. In this embodiment, n-type GaN doped with Si and p-type GaN doped with Mg are used, but impurities doped in GaN are not limited thereto.

First, as shown in FIG. 19A, a mask 94 having growth holes 94a is formed on a substrate 90 made of n-type GaN. As the mask 94, a material that can be selectively etched against a semiconductor core and a semiconductor layer, such as silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ), may be used. Formation of the growth hole 94a can use the well-known lithography method and the dry etching method used for a normal semiconductor process. At this time, the diameter of the growing semiconductor core depends on the size of the growth hole 94a of the mask 94.

Subsequently, an island-shaped catalyst metal layer 95 is formed on the substrate 90 exposed by the growth hole 94a of the mask 94 (catalyst metal layer forming step). As the catalyst metal layer, materials such as Ni, Fe, Au, etc., which are obtained by dissolving them in compound semiconductor materials such as Ga, N, In, and Al, and impurity materials such as Si and Mg, and which are difficult to form compounds with themselves are used. Can be. The island-like catalyst metal layer 95 on the substrate 90 exposed to the growth holes 94a masks a resist (not shown) used when the growth holes 94a are formed by lithography and dry etching. 94), a catalyst metal layer is formed on the resist and the substrate 90 by a thickness of about 100 nm to 300 nm, and is removed by removing the catalyst metal layer on the resist with the resist by a lift-off method.

Subsequently, as shown in Fig. 19B, the MO-type device is used on the substrate 90 on which the island-shaped catalyst metal layer 95 is formed, and is n-type from the interface between the island-shaped catalyst metal layer 95 and the substrate 90. Crystal growth of GaN forms a semiconductor core 91 made of rod-shaped n-type GaN (semiconductor core forming step). The growth temperature is set at about 800 ° C., trimethylgallium (TMG) and ammonia (NH ₃ ) are used as growth gases, silane (SiH ₄ ) is used for n-type impurity supply, and hydrogen (H ₂ ) is used as a carrier gas. By supplying, the n-type GaN semiconductor core 91 made of Si can be grown. Here, the n-type GaN becomes hexagonal crystal growth, and a hexagonal pillar-shaped semiconductor core is obtained by growing with the c-axis direction perpendicular to the surface of the substrate 90.

Subsequently, as shown in FIG. 19C, the outer circumferential surface of the semiconductor core 91 and the catalyst metal layer 95 and the catalyst metal layer 95 are held in a state where the island-like catalyst metal layer 95 is held at the tip of the semiconductor core 91. The p-type semiconductor layer 92 covering the surface of the semiconductor core 91 is formed by crystal growth from the interface (semiconductor layer forming step). In this semiconductor layer formation step, the formation temperature is set to about 900 ° C., and trimethylgallium (TMG) and ammonia (NH ₃ ) are used as growth gases, and biscyclopentadienyl magnesium (Cp ₂ Mg) is used for p-type impurity supply. As a result, p-type GaN containing magnesium (Mg) as an impurity can be grown.

Subsequently, as shown in FIG. 19D, in the exposure step, the rod-like semiconductor is removed by removing the region and mask 94 (shown in FIG. 19C) except for the portion covering the semiconductor core 91 of the semiconductor layer 92 by etching. An exposed portion 91a is formed by exposing the outer circumferential surface of the core 91 on the substrate 90 side. In this state, the island-shaped catalyst metal layer 95 is removed and a part of the upper end of the semiconductor core 91 is removed, but the diameter of the portion 92b of the semiconductor layer 92 covering the outer circumferential surface of the semiconductor core 91 is removed. The thickness in the axial direction of the portion 92a covering the end surface of the other end side of the semiconductor core 91 is thicker than the thickness in the direction.

When the mask is made of silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ), using a solution containing hydrofluoric acid (HF) does not easily affect the semiconductor core and the portion of the semiconductor layer covering the semiconductor core. The mask can be etched without etching, and the semiconductor layer (region except the portion of the semiconductor layer covering the semiconductor core) on the mask can be removed by lift-off together with the mask. In the exposure step of this embodiment, the mask can be easily etched by dry etching using CF ₄ or XeF ₂ without affecting the semiconductor core and the portion of the semiconductor layer covering the semiconductor core, and the semiconductor layer on the mask together with the mask ( Region except for a portion of the semiconductor layer covering the semiconductor core) can be removed.

Subsequently, in the separation step, the semiconductor core is placed on the substrate 90 by immersing the substrate in an isopropyl alcohol (IPA) aqueous solution and vibrating the substrate 90 along the substrate plane using ultrasonic waves (for example, several tens of microseconds). A stress acts on the semiconductor core 91 covered with the semiconductor layer 92 so that the source close to the substrate 90 side of the 91 is bent, and as shown in FIG. 19E, the semiconductor covered with the semiconductor layer 92. Core 91 is separated from substrate 90.

In this way, a fine rod-shaped light emitting device separated from the substrate 90 can be manufactured. In this eighth embodiment, the rod-shaped light emitting device has a diameter of 1 占 퐉 and a length of 10 占 퐉 (the length of the bar-shaped light emitting device is shortened in FIGS. 19A to 19E to make the drawing easy to see).

In addition, the rod-shaped structure light emitting device is a semiconductor having fewer crystal defects because the semiconductor layer 92 crystal grows radially outward from the outer circumferential surface of the semiconductor core 91, the growth distance in the radial direction is short, and defects are avoided outward. The layer 92 can cover the semiconductor core 91. Therefore, a rod-shaped structure light emitting device having good characteristics can be realized.

In this manner, in the rod-shaped structure light emitting device separated from the substrate 90, one electrode is connected to the exposed portion 91a of the semiconductor core 91, and the other electrode is connected to the semiconductor layer 92 so that the semiconductor core ( Light is emitted from the pn junction by flowing a current between the electrodes so that recombination of electrons and holes occurs at the pn junction between the outer circumferential surface of 91 and the inner circumferential surface of the semiconductor layer 92.

P covering the surface of the semiconductor core 91 in a state where the island-like catalyst metal layer 95 is held at the tip of the semiconductor core 91 without removing the island-like catalyst metal layer 95 in the semiconductor layer forming step. Formation of the semiconductor layer 92 promotes crystal growth from the interface between the catalyst metal layer 95 and the semiconductor core 91 rather than the outer circumferential surface of the semiconductor core 91, so that a portion 92b covering the outer circumferential surface of the semiconductor core 91 is provided. It is possible to easily form the semiconductor layer 92 whose thickness in the axial direction of the portion 92a covering the end surface of the other end side of the semiconductor core 91 is larger than the thickness in the radial direction.

According to the method for producing a rod-shaped structure light emitting device, it is possible to manufacture a fine rod-shaped structure light emitting device having a high degree of freedom in mounting to an apparatus. Here, the fine rod-shaped light emitting device is, for example, a micro order size having a diameter of 1 μm and a length of 10 μm, or a nano order size having at least a diameter of less than 1 μm in diameter or length. In addition, the rod-shaped structured light emitting device can reduce the amount of semiconductor used, and it is possible to reduce the thickness and weight of the device using the light emitting device and to emit light from the entire circumference of the semiconductor core covered with the semiconductor layer. Since the light emitting area is wider, a high luminous efficiency and a power saving backlight, lighting device, display device, and the like can be realized.

In addition, the semiconductor core is formed in a state where the island-like catalyst metal layer 95 is held at the tip of the semiconductor core 91 without removing the island-like catalyst metal layer 95 before the semiconductor layer forming step of forming the semiconductor layer 92. You may form a quantum well layer so that the surface of (91) may be covered. Thereby, the quantum well layer which is thicker in the axial direction of the part which covers the end surface of the other end side of a semiconductor core than the thickness of the radial direction of the part which covers the outer peripheral surface of a semiconductor core can be formed easily.

The rod-shaped structure light emitting element of the ninth embodiment has the same effect as the rod-shaped structure light emitting element of the fifth embodiment.

Moreover, the thickness of the axial direction of the part 92a which covers the end surface of the other end side of the semiconductor core 91 rather than the thickness of the radial direction of the part 92b which covers the outer peripheral surface of the semiconductor core 91 in the said semiconductor layer 92 The thickness of the semiconductor core 91 is connected to the semiconductor layer 92 without overlapping the electrode connected to the semiconductor layer 92 side covering the end surface of the other end side of the semiconductor core 91 to the position of the end surface of the other end side of the semiconductor core 91. Therefore, the extraction efficiency of the light of the whole side surface of the semiconductor core 91 can be improved. In addition, the thickness of the semiconductor layer 92 in the axial direction of the portion 92a covering the end surface of the other end side of the semiconductor core 91 is greater than the thickness in the radial direction of the portion 92b covering the outer circumferential surface of the semiconductor core 91. Since it is thick, the resistance of the portion 92a of the semiconductor layer 92 covering the end surface of the other end side of the semiconductor core 91 becomes high, so that light emission does not concentrate on the other end side of the semiconductor core 91 so that the side surface of the semiconductor core 91 The light emission of the region can be enhanced, and the leakage current in the portion 92a of the semiconductor layer 92 covering the end surface of the other end side of the semiconductor core 91 can be suppressed.

In the first to fourth embodiments, a rod-shaped structure light emitting device having exposed portions 11, 21, 31, and 41 having exposed outer peripheral surfaces of one end side of the semiconductor cores 11, 21, 31, and 41 has been described. The present invention is not limited to this, and may have exposed portions in which the outer peripheral surfaces of both ends of the semiconductor core are exposed, or may have exposed portions in which the outer peripheral surfaces of the central portion of the semiconductor core are exposed.

In the first to ninth embodiments, a semiconductor based on GaN is used as the semiconductor core and the semiconductor layer, but light emission using a semiconductor based on GaAs, AlGaAs, GaAsP, InGaN, AlGaN, GaP, ZnSe, AlGaInP, etc. You may apply this invention to an element. In addition, although the semiconductor core is n-type and the semiconductor layer is p-type, you may apply this invention to the rod-shaped structure light emitting element whose electroconductive type is the opposite. Moreover, although the rod-shaped structure light emitting element which has a hexagonal pillar-shaped semiconductor core was demonstrated, it is not limited to this, The cross-section may be circular or oval rod-shaped, and the cross-section is rod-shaped semiconductor which is another polygonal shape, such as a triangle. You may apply this invention to the rod-shaped structure light emitting element which has a core.

In addition, in the said 1st-9th embodiment, although the diameter of the rod-shaped structure light emitting element was set to 1 micrometer, and it was set as the micro order size of 10 micrometers-30 micrometers in length, at least the diameter or length of the nano order size of less than 1 micrometer is used. An element may be sufficient. The diameter of the semiconductor core of the rod-shaped structure light emitting device is preferably 500 nm or more and 50 μm or less, and the variation in the diameter of the semiconductor core can be suppressed as compared with the rod-shaped structure light emitting device of several tens of nm to several hundred nm. The deviation of the luminescence properties can be reduced and the yield can be improved.

In the first to fourth and seventh to ninth embodiments, the semiconductor core is grown by using a MOCVD apparatus, but the semiconductor core may be formed using another crystal growth apparatus such as an MBE (molecular beam epitaxial) apparatus. . In addition, although the semiconductor core is crystal-grown on the substrate using a mask having growth holes, the semiconductor core may be crystal-grown from the metal species by disposing a metal species on the substrate.

In addition, in the said 1st-4th, 7th-9th embodiment, although the semiconductor core covered with the semiconductor layer was isolate | separated from the board | substrate using ultrasonic wave, it is not limited to this, The semiconductor core was removed from a board | substrate using a cutting tool. You may isolate by bending mechanically. In this case, a plurality of fine rod-shaped structure light emitting elements provided on the substrate can be separated in a short time by a simple method.

[Tenth Embodiment]

20 is a sectional view of a rod-shaped structure light emitting device of a tenth embodiment of the present invention.

As shown in FIG. 20, the rod-shaped structure light emitting element A of the tenth embodiment has a semiconductor core 111 made of rod-shaped n-type GaN having a substantially hexagonal cross section and one of the semiconductor cores 111. An exposed portion 111a of the semiconductor core 111 so as to be an exposed portion 111a without covering the cap layer 112 covering the end surface and a portion opposite to the portion of the semiconductor core 111 covered with the cap layer 112. The semiconductor layer 113 which consists of p-type GaN which covers the outer peripheral surface of other parts is provided. The outer circumferential surface of the semiconductor core 111 and the outer circumferential surface of the cap layer 112 are covered by the continuous semiconductor layer 113.

The cap layer 112 is a material having a higher electrical resistance than the semiconductor layer 113, for example, an insulating material, an intrinsic GaN, n-type GaN having a low impurity concentration, and a semiconductor. A p-type GaN or the like having a different conductivity type than that of the layer 113 and low impurity concentration is used.

According to the rod-shaped structure light emitting element A having the above configuration, the semiconductor layer 111 of one end of the semiconductor core 111 made of rod-shaped n-type GaN is covered with the cap layer 112 and the semiconductor is covered with the cap layer 112. The semiconductor layer 113 made of p-type GaN has an outer circumferential surface of a portion other than the exposed portion 111a of the semiconductor core 111 so as to be an exposed portion 111a without covering the portion opposite to the portion of the core 111. Part of the semiconductor layer 113 which covers the semiconductor core 111 by connecting the exposed part 111a of the semiconductor core 111 to the n-side electrode, even if it is the fine rod-shaped structure light emitting element of a micro order size or nano order size by covering. The p-side electrode can be connected to the. The rod-shaped structure light emitting device A connects the n-side electrode to the exposed portion 111a of the semiconductor core 111 and the p-side electrode to the semiconductor layer 113 to transfer current from the p-side electrode to the n side electrode. By flowing, recombination of electrons and holes occurs at an interface (pn junction) between the outer circumferential surface of the semiconductor core 111 and the inner circumferential surface of the semiconductor layer 113 to emit light. In the rod-shaped structure light emitting device A, since light is emitted from the entire side surface of the semiconductor core 111 covered with the semiconductor layer 113, the light emitting area is widened, so that the light emitting efficiency is high.

Therefore, a fine rod-shaped structure light emitting element A having a high luminous efficiency that can be easily connected to an electrode with a simple configuration can be realized. Further, since the rod-shaped structure light emitting device A is not integral with the substrate, the degree of freedom in mounting to the device is high.

Here, the fine rod-shaped light emitting device is, for example, a micro-order size having a diameter of 1 µm and a length of 10 µm to 30 µm, or a nano-order size having at least a diameter of less than 1 µm in diameter or length. In addition, the rod-shaped structured light emitting device can reduce the amount of semiconductors used, and it is possible to reduce the thickness and weight of the device using the light emitting device, and to provide high luminous efficiency, power saving light emitting device, backlight, lighting device and display device. Etc. can be realized.

In addition, one n-side electrode is connected to the exposed portion 111a of the outer circumferential surface of the one end side of the semiconductor core 111 by exposing the outer circumferential surface of the one end side of the semiconductor core 111, for example, about 1 μm to 5 μm. The p-side electrode can be connected to the semiconductor layer 113 on the other end side of the semiconductor core 111, and the electrodes can be connected by separating the electrodes at both ends, and the p-side electrode and the semiconductor core connected to the semiconductor layer 113 ( Shorting of the exposed portion 111a of the 111 can be easily prevented.

In addition, since one end surface of the semiconductor core 111 is covered by the cap layer 112, the semiconductor layer 113 is covered with a portion of the semiconductor layer 113 that covers the outer circumferential surface on the side opposite to the exposed portion 111a of the semiconductor core 111. The p-side electrode can be easily connected without shorting the core 111. Thereby, an electrode can be easily connected to the both ends of the fine rod-shaped structure light emitting element A. FIG.

Fig. 21 shows a cross-sectional schematic diagram of the main parts of the rod-shaped light emitting device of Comparative Example, and is not a rod-shaped light emitting device of the present invention. The rod-shaped light emitting element of FIG. 21 differs from the rod-shaped light emitting element A shown in FIG. 20 of the tenth embodiment in that there is no cap layer covering one end surface of the semiconductor core 1011, and the semiconductor layer 1013. ) Covers the outer circumferential surface and the end surface of the semiconductor core 1011.

As shown in FIG. 21, when the p-side electrode 1014 is connected to the semiconductor layer 1013 on the end face side of the semiconductor core 1011, the cross-sectional area of the semiconductor layer 1013 covering the end face side of the semiconductor core 1011. The resistance of this large film thickness direction (resistance viewed from the p-side electrode 1014 side) becomes small, while the cross-sectional area of the semiconductor layer 1013 covering the outer circumferential surface of the semiconductor core 1011 is small in the longitudinal direction (p-side electrode 1014). The resistance of the resistance viewed from the side) increases. For this reason, the electric current to the end surface of the semiconductor core 1011 is concentrated, and light emission is concentrated on the end surface of the semiconductor core 1011, and light is not efficiently emitted from the whole side surface of the semiconductor core 1011.

On the other hand, as shown in the cross-sectional schematic diagram of FIG. 22, in the rod-shaped structure light emitting device shown in FIG. 20 of the tenth embodiment, the cap layer 112 made of a material having a larger electrical resistance than the semiconductor layer 113 is a semiconductor core. By covering the one end surface of the semiconductor core 111 of the (111) through the cap layer 112 between the p-side electrode 14 and the semiconductor core 111 connected to the cap layer 112 side of the semiconductor core 111 While the current does not flow, current flows between the p-side electrode 14 and the outer peripheral surface side of the semiconductor core 111 through the semiconductor layer 113 having a lower resistance than the cap layer 112. This suppresses the concentration of current to the end face of the side where the cap layer 112 of the semiconductor core 111 is provided, so that light emission is not concentrated on the end face of the semiconductor core 111, and from the side surface of the semiconductor core 111. The extraction efficiency of light is improved.

23A to 23C show cross-sectional views of principal parts of first to third modified examples of the rod-shaped structure light emitting device according to the tenth embodiment. In FIGS. 23A to 23C, the shape of the semiconductor layer 113 is different from that of FIG. 20, but the same reference numerals are assigned to the same components as those in FIG. 20.

In the rod-shaped structure light emitting device of the present invention, as shown in the first modification of FIG. 23A, the semiconductor layer 113 is formed so as to cover a part of the semiconductor core 111 side of the outer peripheral surface of the cap layer 112. As shown in the second modification of FIG. 23B, the semiconductor layer 113 is formed so as to cover the entire outer circumferential surface of the cap layer 112 and protrude beyond the end surface of the cap layer 112, thereby exposing the end surface of the cap layer 112. It may be. In the rod-shaped structure light emitting device of the present invention, as shown in the third modification of FIG. 23C, the semiconductor layer 113 is formed so as to cover the entire outer circumferential surface of the cap layer 112 and the end surface of the cap layer 112. You may also do it.

24 and 25 show the cross-sectional schematic diagrams of the main parts of the rod-shaped structure light emitting device according to the modification in which the semiconductor layer does not cover the outer circumferential surface of the cap layer. 24 and 25, 1021 and 1031 are semiconductor cores, 1022 and 1032 are cap layers, 1023 and 1033 are semiconductor layers, and 1024 and 1034 are p-side electrodes, and the material of each part is the rod-shaped light emitting structure of the tenth embodiment. The same material as the element is used.

In the rod-shaped structure light emitting device of the modification shown in FIG. 24, since the semiconductor layer 1023 covers only a small area in the vicinity of the semiconductor core 1021 of the outer circumferential surface of the cap layer 132, a current path is formed in this portion so that this current path is formed. There is a possibility that a leakage current flows between the p-side electrode 1024 and the semiconductor core 1021 through.

In addition, in the rod-shaped structure light emitting device of the modification shown in FIG. 25, the semiconductor layer 1033 does not cover the outer circumferential surface of the cap layer 1032, but the current comes into contact with the end surface of the semiconductor layer 1033 and the end surface of the cap layer 1032. There is a fear that a path is formed so that a leakage current flows between the p-side electrode 1034 and the semiconductor core 1031 through this current path.

On the other hand, according to the rod-shaped structure light emitting element A shown in FIG. 20 of the tenth embodiment, the semiconductor layer in which the outer circumferential surface of the semiconductor core 111 except the exposed portion 111a and the outer circumferential surface of the cap layer 112 are continuous. By covering by 113, the leakage current between the p-side electrode 14 and the semiconductor core 111 connected to the cap layer 112 side of the semiconductor core 111 can be suppressed.

In addition, in the rod-shaped structure light emitting device A, the capping layer 112 of the semiconductor core 111 is completely insulated from the electrode by the capping layer 112 by using an insulating material for the capping layer 112. In addition to suppressing light emission from the end face of the side on which this is provided, the occurrence of leakage current between the semiconductor core 111 and the electrode can be suppressed in the vicinity of the end face of the semiconductor core 111.

In addition, even when intrinsic semiconductor is used for the cap layer 112 in the rod-shaped structure light emitting device A, since the semiconductor core 111 is completely insulated from the electrode by the cap layer 112, the cap layer of the semiconductor core 111 is used. In addition to suppressing light emission from the end face on the side where the 112 is provided, the occurrence of leakage current between the semiconductor core 111 and the electrode can be suppressed in the vicinity of the end face of the semiconductor core 111. For example, when GaN is used as an intrinsic semiconductor, it actually becomes an n-type containing impurities, but since the impurity concentration is low and high resistance, almost no current flows to the cap layer 112 side. It is possible to apply between 111 and the semiconductor layer 113 covering the outer circumferential surface thereof.

Also, in the rod-shaped structure light emitting device A, when the same n-type semiconductor as the semiconductor core 111 is used for the cap layer 112, the cap layer 112 is higher in resistance than the semiconductor layer 113. While suppressing light emission from the end face of the side where the cap layer 112 of the (111) is provided, the occurrence of leakage current between the semiconductor core 111 and the electrode can be suppressed in the vicinity of the end face of the semiconductor core 111. have.

In the rod-shaped light emitting device A, when the same p-type semiconductor as the semiconductor layer 113 is used for the cap layer 112, the light emitting surface is formed on the end surface of the semiconductor core 111 on which the cap layer 112 is provided. Since the light emitting area is formed, the light emitting area can be increased. In addition, since the cap layer 112 has a higher resistance than the semiconductor layer, the current flowing to the end surface of the cap layer 112 side of the semiconductor core 111 is small and sufficient voltage is applied between the semiconductor core 111 and the semiconductor layer 113 covering the outer circumferential surface thereof. It becomes possible to apply to.

In addition, in the tenth embodiment, the rod-shaped structure light emitting device in which the semiconductor layer is coated on the rod-shaped semiconductor core 111 having a substantially hexagonal cross section has been described. You may apply this invention to the rod-shaped structure light emitting element which coat | covered the well layer etc. The n-type GaN becomes hexagonal crystal growth, and grows in a c-axis direction perpendicular to the substrate surface to obtain a substantially hexagonal columnar semiconductor core. Depending on growth conditions such as growth direction and growth temperature, when the diameter of the semiconductor core to be grown is small, about tens of nm to hundreds of nm, the cross-section tends to be almost circular in shape, and the diameter is about 0.5 μm. If the thickness is increased to several micrometers, the cross section may be easily grown in a hexagon.

[Eleventh Embodiment]

Fig. 26 is a sectional view of a rod-shaped structure light emitting device of an eleventh embodiment of the present invention. The rod-shaped structure light emitting element of this eleventh embodiment has the same structure as the rod-shaped structure light emitting element of the tenth embodiment except for the quantum well layer.

As shown in FIG. 26, the rod-shaped structure light emitting element B of the eleventh embodiment includes a semiconductor core 121 made of rod-shaped n-type GaN having a substantially hexagonal cross section and one of the semiconductor cores 121. A quantum well layer 125 made of p-type InGaN covering an end surface, a cap layer 122 covering an outer circumferential surface of the quantum well layer 125, and a portion of the semiconductor core 121 covered with the cap layer 122. The semiconductor layer 123 which consists of p-type GaN which covers the outer peripheral surface of parts other than the exposed part 121a of the semiconductor core 121 is provided so that it may become the exposed part 121a without covering the part on the opposite side. The outer circumferential surface of the semiconductor core 121 and the outer circumferential surface of the cap layer 122 are covered by the continuous semiconductor layer 123.

The rod-shaped structure light emitting element of the eleventh embodiment has the same effect as the rod-shaped structure light emitting element of the tenth embodiment.

In the rod-shaped light emitting device of the eleventh embodiment, a quantum well layer 125 made of p-type InGaN is formed between the end surface of the semiconductor core 121 and the cap layer 122 to form the quantum well layer 125. By the quantum confinement effect, the luminous efficiency at the interface between the end surface of the semiconductor core 121 and the cap layer 122 can be improved.

The quantum well layer may be a multi-quantum well structure in which a GaN barrier layer and an InGaN quantum well layer are alternately stacked.

[Twelfth Embodiment]

27 is a sectional view of a rod-shaped structure light emitting device of a twelfth embodiment of the present invention.

As shown in FIG. 27, the rod-shaped structure light emitting element C of the twelfth embodiment includes a semiconductor core 131 made of rod-shaped n-type GaN having a substantially hexagonal cross section and one of the semiconductor cores 131. An exposed portion 131a of the semiconductor core 131 so as to be an exposed portion 131a without covering a cap layer 132 covering an end surface and a portion opposite to a portion of the semiconductor core 131 covered with the cap layer 132. A quantum well layer 133 made of p-type InGaN covering the outer circumferential surface of the other portion and a semiconductor layer 34 made of p-type GaN covering the outer circumferential surface of the quantum well layer 133 are provided. The outer circumferential surface of the semiconductor core 131 and the outer circumferential surface of the cap layer 132 are covered by the continuous quantum well layer 133 and the semiconductor layer 134.

The cap layer 132 is a material having a higher electrical resistance than the semiconductor layer 134. For example, an insulating material, an intrinsic GaN, and an n-type GaN semiconductor layer 134 having a low impurity concentration and the same conductivity type as the semiconductor layer 134. P-type GaN with a different conductivity type and low impurity concentration is used.

FIG. 28 is a sectional view of a main portion of the rod-shaped structure light emitting element C. As shown in FIG. 28, in the rod-shaped structure light emitting element C of the twelfth embodiment, the electrical resistance is higher than that of the semiconductor layer 134. The cap layer 132 made of this large material covers one end surface of the semiconductor core 131 so that the p-side electrode 135 connected to the cap layer 132 side of the semiconductor core 131 and the semiconductor core 131 are formed. While the current does not flow through the cap layer 132, the current flows between the p-side electrode 135 and the outer circumferential surface side of the semiconductor core 131 through the semiconductor layer 134 having a lower resistance than the cap layer 132. . This suppresses the concentration of current to the end surface of the side where the cap layer 132 of the semiconductor core 131 is provided, so that the light emission is not concentrated on the end surface of the semiconductor core 131, and from the side surface of the semiconductor core 131. The extraction efficiency of light is improved.

As shown in FIG. 28, in the case where the semiconductor layer 134 is not covered to the end surface of the cap layer 132, the semiconductor core (from the p-side electrode 135 in the planar direction of the quantum well layer 133). Although the leakage current to 131 is expected to be generated, the leakage current is sufficiently large because the resistance of the quantum well layer 133 is small (film thickness is small and the distance from the p-side electrode 135 to the semiconductor core 131 is sufficiently long). Is very small and sufficient voltage can be applied between the semiconductor core 131 and the semiconductor layer 134.

Here, in the quantum well layer 133, the distance from the p-side electrode 135 to the semiconductor core 131 corresponds to approximately 1 μm to 5 μm in length, for example, of the cap layer 132.

The rod-shaped structure light emitting element of the twelfth embodiment has the same effect as the rod-shaped structure light emitting element of the tenth embodiment.

29A to 29C show cross-sectional views of principal parts of first to third modified examples of the rod-shaped structure light emitting device according to the twelfth embodiment. In FIGS. 29A to 29C, the shapes of the quantum well layer 133 and the semiconductor layer 134 are different from those in FIG. 27, but the same reference numerals are assigned to the same components as those in FIG. 27.

In the rod-shaped structure light emitting device of the present invention, as shown in the first modification of FIG. 29A, the quantum well layer 133 and the semiconductor layer (so as to cover a part of the semiconductor core 131 side of the outer circumferential surface of the cap layer 132) 134 may be formed, and as shown in the second modification of FIG. 29B, the quantum well layer 133 and the semiconductor layer (2) cover the entire outer circumferential surface of the cap layer 132 and protrude beyond the end surface of the cap layer 132. 134 may be formed so that the end surface of the cap layer 132 may be exposed. In addition, in the rod-shaped light emitting device of the present invention, as shown in the third modification of FIG. 29C, the quantum well layer 133 and the quantum well layer 133 are covered to cover the entire outer circumferential surface of the cap layer 132 and the end surface of the cap layer 132. The semiconductor layer 134 may be formed.

30 and 31 show schematic cross-sectional views of the main parts of the rod-shaped structure light emitting device according to the modification in which the outer circumferential surface of the cap layer is not covered with the quantum well layer and the semiconductor layer.

30 and 31, 1041 and 1151 are semiconductor cores, 1042 and 1152 are cap layers, 1043 and 1153 are quantum well layers, 1044 and 1154 are semiconductor layers, and 1045 and 1155 are p-side electrodes. The same material as the rod-shaped structure light emitting device of the twelfth embodiment is used.

In the rod-shaped structure light emitting device of the modification shown in FIG. 30, the quantum well layer 1043 and the semiconductor layer 1044 cover only a small region near the semiconductor core 1041 of the outer circumferential surface of the cap layer 1042. There is a fear that a path is formed so that a leakage current flows between the p-side electrode 1045 and the semiconductor core 1041 through this current path.

Also, in the rod-shaped structure light emitting device of the modification shown in FIG. 31, the semiconductor layer 1154 does not cover the outer circumferential surface of the cap layer 1152, and the current comes into contact with the end surface of the semiconductor layer 1154 and the end surface of the cap layer 1152. There is a fear that a path is formed so that a leakage current flows between the p-side electrode 1155 and the semiconductor core 1151 through this current path.

On the other hand, according to the rod-shaped structure light emitting element shown in FIG. 27 of the twelfth embodiment, the semiconductor layer 134 is formed by continuously connecting the outer circumferential surface of the semiconductor core 131 except the exposed portion 131a and the outer circumferential surface of the cap layer 132. By covering by this, the leakage current from the p-side electrode 135 connected to the cap layer 132 side of the semiconductor core 151 to the semiconductor core 131 can be suppressed.

In addition, in the rod-shaped light emitting device of the eleventh embodiment, the quantum well layer 133 is formed between the outer circumferential surface of the semiconductor core 131 and the semiconductor layer 134 to effect the quantum confinement of the quantum well layer 133. As a result, the luminous efficiency at the interface between the outer circumferential surface of the semiconductor core 131 and the semiconductor layer 134 can be improved.

The quantum well layer may be a multi-quantum well structure in which a GaN barrier layer and an InGaN quantum well layer are alternately stacked.

In addition, according to the rod-shaped structure light emitting device, the semiconductor core 131 is covered by a continuous quantum well layer 133 covering the outer circumferential surface of the semiconductor core 131 except the exposed portion 131a and the outer circumferential surface of the cap layer 132. The leakage current between the electrode connected to the cap layer 132 side and the semiconductor core 131 can be suppressed.

[Thirteenth Embodiment]

32 is a sectional view of a rod-shaped structure light emitting device of a thirteenth embodiment of the present invention. The rod-shaped structure light emitting element of this thirteenth embodiment has the same configuration as the rod-shaped structure light emitting element of the twelfth embodiment except for the conductive layer.

As shown in FIG. 32, the rod-shaped structure light emitting device D of the thirteenth embodiment includes a semiconductor core 141 made of rod-shaped n-type GaN having a substantially hexagonal cross section and one of the semiconductor cores 141. An exposed portion 141a of the semiconductor core 141 so as to be an exposed portion 141a without covering the cap layer 142 covering the end surface and a portion opposite to the portion of the semiconductor core 141 covered with the cap layer 142. A quantum well layer 143 made of p-type InGaN covering the outer circumferential surface of the other portion, a semiconductor layer 144 made of p-type GaN covering the outer circumferential surface of the quantum well layer 143, and the semiconductor layer 144 A conductive layer 145 covering the outer circumferential surface is provided. The outer circumferential surface of the semiconductor core 141 and the outer circumferential surface of the cap layer 142 are covered by the continuous quantum well layer 143 and the semiconductor layer 144.

The conductive layer 145 is formed of ITO (tin-added indium oxide) having a thickness of 200 nm. The deposition of this ITO can be carried out by vapor deposition or sputtering. After the ITO film is formed, the heat treatment is performed at 500 ° C. to 600 ° C. to lower the contact resistance of the semiconductor layer 144 made of p-type GaN and the conductive layer 145 made of ITO. The conductive layer 145 is not limited to this, and a translucent laminated metal film of Ag / Ni or Au / Ni having a thickness of 5 nm may be used, for example. A vapor deposition method or a sputtering method can be used for film formation of this laminated metal film. Further, in order to lower the resistance of the conductive layer, a laminated metal film of Ag / Ni or Au / Ni may be laminated on the ITO film.

FIG. 33: is a cross-sectional schematic diagram of the principal part of the said rod-shaped structure light emitting element D. As shown in FIG. 33, in the rod-shaped structure light emitting element D of this 13th Embodiment, it is more electric than the semiconductor layer 144. FIG. The cap layer 142 made of a material having a high resistance covers one end surface of the semiconductor core 141 so that the p-side electrode 146 connected to the cap layer 142 side of the semiconductor core 141 is connected to the semiconductor core 141. In order to prevent current from flowing through the cap layer 142, the outer peripheral surface side of the p-side electrode 146 and the semiconductor core 141 through the conductive layer 145 and the semiconductor layer 144 having lower resistance than the cap layer 142. Allow current to flow between them. This suppresses the concentration of current to the end face of the side where the cap layer 142 of the semiconductor core 141 is provided, and thus the light emission is not concentrated on the end face of the semiconductor core 141. The extraction efficiency of light is improved.

The rod-shaped structure light emitting element of the thirteenth embodiment has the same effect as the rod-shaped structure light emitting element of the tenth embodiment.

In addition, according to the rod-shaped light emitting device, the semiconductor layer 144 is connected to the electrode through the conductive layer 145 having a lower resistance than the semiconductor layer 144 so that the current is concentrated and concentrated in the electrode connection portion. By forming a current path, the entire surface of the side surface of the semiconductor core 141 can be efficiently emitted, and the luminous efficiency is further improved.

34, the n-side electrode 147 as an example of the first electrode is connected to the exposed portion 141a of the semiconductor core 141, and as shown in FIG. The p-side electrode 148 as an example of the second electrode is connected to the side where the cap layer 142 is provided.

In FIG. 34, since one end surface of the semiconductor core 141 is not exposed by the cap layer 142, the semiconductor core 141 and the p-side electrode 148 through the semiconductor layer 144 and the conductive layer 145 at the end thereof. ) Can facilitate electrical connection. Thereby, the area which the p-side electrode 148 blocks among the whole side surfaces of the semiconductor core 141 covered with the semiconductor layer 144 and the conductive layer 145 can be minimized, and light extraction efficiency can be improved. . In addition, the concentration of current to the end surface of the side where the cap layer 142 of the semiconductor core 141 is provided is suppressed, so that light emission is not concentrated on the end surface of the semiconductor core, and the light extraction efficiency from the side surface of the semiconductor core 141 is improved. do.

In addition, the semiconductor core 141 and the p-side electrode 148 may be electrically connected only at the end portion of the semiconductor core 141 at the cap layer 142 side through the conductive layer 145.

[14th Embodiment]

35 is a perspective view showing a light emitting device including a rod-shaped structure light emitting element according to a fourteenth embodiment of the present invention. In this fourteenth embodiment, a rod-shaped light emitting device having the same structure as that of the rod-shaped light emitting device C of the twelfth embodiment is used. In addition, any of the rod-shaped structure light emitting elements of the first, eleventh, and thirteenth embodiments may be used for the rod-shaped structure light emitting elements.

As shown in FIG. 35, the light emitting device of the fourteenth embodiment includes an insulating substrate 100 having metal electrodes 101 and 102 formed on a mounting surface thereof, and an insulating substrate 100 having a longitudinal direction on the insulating substrate 100. The rod-shaped structure light emitting element E mounted so as to be parallel to the mounting surface of the device is provided.

The rod-shaped structure light emitting device E includes a semiconductor core 151 made of rod-shaped n-type GaN having a substantially hexagonal cross section, a cap layer (not shown) covering one end surface of the semiconductor core 151, and the cap layer. P-type InGaN covering the outer circumferential surface of portions other than the exposed portion 151a of the semiconductor core 151 so as to be the exposed portion 151a without covering the portion opposite to the portion of the semiconductor core 151 covered with 152. And a semiconductor layer 154 made of p-type GaN covering the outer circumferential surface of the quantum well layer 153. The semiconductor core 151 has an exposed portion 151a through which an outer circumferential surface of one end thereof is exposed. The end surface of the cap layer on the other end side of the semiconductor core 151 is exposed without being covered with the quantum well layer 153 and the semiconductor layer 154.

As shown in FIG. 35, while connecting the exposed part 151a of the one end side of the rod-shaped structure light emitting element E to the metal electrode 101, the semiconductor layer of the other end side of the rod-shaped structure light emitting element E 154 is connected to the metal electrode 102.

Here, the rod-shaped light emitting device E is the liquid droplet of the gap between the substrate surface and the gap between the rod-shaped light emitting device during evaporation of the IPA aqueous solution in the arrangement method of the rod-shaped light emitting device according to the 38th embodiment described later. The center portion is bent and contacted on the insulating substrate 100 by a stiction generated when it is reduced.

According to the light emitting device of the fourteenth embodiment, the rod-shaped structure light emitting device E mounted on the insulating substrate 100 so that the longitudinal direction thereof is parallel to the mounting surface is the outer peripheral surface of the semiconductor layer 154 and the insulating substrate 100. Since the mounting surface of the contact surface is in contact with each other, heat generated in the rod-shaped structure light emitting device E can be efficiently radiated from the semiconductor layer 154 to the insulating substrate 100. Therefore, a light emitting device having high luminous efficiency and good heat dissipation can be realized. In addition, in the rod-shaped structure light emitting device in which the conductive layer is formed to cover the semiconductor layer, the effect is similarly obtained by contacting the outer circumferential surface of the conductive layer and the mounting surface of the insulating substrate.

In the light emitting device, since the rod-shaped structure light emitting device E is laid on the insulating substrate 100 sideways, the thickness including the insulating substrate 100 can be reduced. In the above light emitting device, for example, a micro rod size having a diameter of 1 μm and a length of 10 μm or a fine rod-shaped structure light emitting element E having a nano order size of at least one of diameters or lengths of less than 1 μm is used. The amount of semiconductor can be reduced, and a backlight, an illumination device, a display device, and the like, which can be made thinner and lighter, can be realized using this light emitting device.

[Fifteenth Embodiment]

36 is a side view of a light emitting device including a rod-shaped structure light emitting device according to a fifteenth embodiment of the present invention.

As shown in FIG. 36, the light emitting device of the fifteenth embodiment is a rod-shaped package in which the longitudinal direction is parallel to the mounting surface of the insulating substrate 100 on the insulating substrate 100 and the insulating substrate 100. The structural light emitting element F is provided.

The rod-shaped structure light emitting device F has a semiconductor core 161 made of a rod-shaped n-type GaN having a substantially hexagonal cross section, and a cap layer 162 covering one end surface of the semiconductor core 151 (shown in FIG. 37). ) And an outer circumferential surface of a portion other than the exposed portion 161a of the semiconductor core 161 so as to be an exposed portion 161a without covering the portion opposite to the portion of the semiconductor core 161 covered with the cap layer 162. A quantum well layer 163 made of p-type InGaN, a semiconductor layer 164 made of p-type GaN covering the outer circumferential surface of the quantum well layer 163, and a conductive layer covering the outer circumferential surface of the semiconductor layer 164 ( 165). The semiconductor core 161 is provided with an exposed portion 161a through which an outer circumferential surface of one end thereof is exposed. A metal layer 166 is formed on the conductive layer 165 as an example of the second conductive layer on the insulating substrate 100 side. The metal layer 166 covers about half of the lower side of the outer circumferential surface of the conductive layer 165. The conductive layer 165 is formed of ITO. The conductive layer is not limited to this, and a translucent laminated metal film of Ag / Ni or Au / Ni having a thickness of 5 nm may be used, for example. A vapor deposition method or a sputtering method can be used for film formation of this laminated metal film. In addition, in order to lower the resistance of the conductive layer, a laminated metal film of Ag / Ni or Au / Ni may be laminated on the 1TO film. The metal layer 166 is not limited to Al, and Cu, W, Ag, Au, or the like may be used.

As shown in FIG. 37, the light emitting device of the fifteenth embodiment has an insulating substrate 100 having metal electrodes 101 and 102 formed on a mounting surface thereof, and an insulating substrate 100 having a longitudinal direction on the insulating substrate 100. The rod-shaped structure light emitting element F mounted so as to be parallel to the mounting surface thereof is provided.

The exposed portion 161a on one end side of the rod-shaped light emitting device F is connected to the metal electrode 101 by an adhesive portion 103 such as a conductive adhesive, and the other of the rod-shaped light emitting device F is connected. The short side metal layer 166 is connected to the metal electrode 102 by adhesion | attachment part 104, such as a conductive adhesive.

Here, the rod-shaped light emitting device F is formed by evaporation of droplets of the gap between the substrate surface and the gap between the bar-shaped light emitting device during evaporation of the IPA aqueous solution in the method of arranging the rod-shaped light emitting device according to the 38th embodiment described later. The center portion is bent and contacted on the insulating substrate 100 by the stiction generated when it is reduced.

According to the light emitting device of the fifteenth embodiment, as an example of the second conductive layer having a lower resistance than the semiconductor layer 164 on the conductive layer 165 of the rod-shaped structure light emitting element F and on the insulating substrate 100 side. Since the metal layer 166 is formed, the conductive layer 165 covering the outer circumferential surface of the semiconductor core 161 is also present on the side opposite to the insulating substrate 100 of the rod-shaped structured light emitting device F without the metal layer 166. It is possible to reduce the resistance by the metal layer 166 without sacrificing the ease of the current flowing through the high resistance semiconductor layer 164. In addition, since the material having low transmittance is not used in the conductive layer 165 covering the outer circumferential surface of the semiconductor core 161, a material having low transmittance is not used, but a material having lower resistance than the transmittance is not included in the metal layer 166. Preferred conductive materials can be used. In addition, in the rod-shaped structure light emitting device F mounted on the insulating substrate 100 so that the longitudinal direction thereof is parallel to the mounting surface, since the metal layer 166 is in contact with the mounting surface of the insulating substrate 100, the rod-shaped structure light emitting device Heat generated in (F) can be efficiently radiated to the insulating substrate 100 through the metal layer 166.

[16th Embodiment]

38 is a perspective view showing a light emitting device including a rod-shaped structure light emitting element according to a sixteenth embodiment of the present invention. In the sixteenth embodiment, a rod-shaped structure light emitting element having the same structure as that of the rod-shaped structure light emitting element (C) of the twelfth embodiment is used. In addition, any of the rod-shaped light emitting elements of the tenth, eleventh and thirteenth embodiments may be used for the rod-shaped light emitting elements.

As shown in FIG. 38, the light emitting device of the sixteenth embodiment has an insulating substrate 200 having metal electrodes 201 and 202 formed on a mounting surface thereof, and an insulating substrate 200 having a longitudinal direction on the insulating substrate 200. The rod-shaped structure light emitting element G is mounted so as to be parallel to the mounting surface. The insulating substrate 200 is provided with a third metal electrode 203 as an example of the metal portion between the metal electrodes 201 and 202 on the insulating substrate 200 and also under the rod-shaped structure light emitting device G. 38 shows only a part of the metal electrodes 201, 202, 203.

The rod-shaped structure light emitting device G includes a semiconductor core 171 made of rod-shaped n-type GaN having a substantially hexagonal cross section, a cap layer (not shown) covering one end surface of the semiconductor core 171, and the cap layer. A quantum well made of a p-type InGaN covering an outer circumferential surface of a portion other than the exposed portion 171a of the semiconductor core 171 so as not to cover the portion opposite to the portion of the semiconductor core 171 covered with the exposed portion 171a. A layer 173 and a semiconductor layer 174 made of p-type GaN covering the outer circumferential surface of the quantum well layer 173. The semiconductor core 171 has an exposed portion 171a through which an outer circumferential surface of one end thereof is exposed. The end face of the cap layer on the other end side of the semiconductor core 171 is exposed without being covered with the quantum well layer 173 and the semiconductor layer 174.

According to the light emitting device of the sixteenth embodiment, the metal electrodes 203 are formed between the electrodes 201 and 202 on the insulating substrate 200 and also below the rod-shaped structure light emitting element G, so that both ends are connected to the metal electrodes 201 and 202. Since the center side of the connected rod-shaped light emitting device G is supported by being brought into contact with the surface of the metal electrode 203, the rod-shaped light emitting device G of both supports is supported by the metal electrode 203 without bending. In addition, heat generated in the rod-shaped structure light emitting device G may be efficiently radiated from the semiconductor layer 174 to the insulating substrate 200 through the metal electrode 203.

As shown in FIG. 39, the metal electrode 201 and the metal electrode 202 are each formed from opposing positions of the bases 201a and 202a and the bases 201a and 202a which are substantially parallel to each other at a predetermined interval. It has a plurality of electrode portions 201b and 202b extending between the bases 201a and 202a. One rod-shaped structure light emitting element G is arranged in the electrode portion 201b of the metal electrode 201 and the electrode portion 202b of the metal electrode 202 opposite to it. Between the electrode portion 201b of the metal electrode 201 and the electrode portion 202b of the metal electrode 202 opposite to it, a butterfly-shaped third metal electrode 203 having a narrow central portion is formed on the insulating substrate 200. To form.

The third metal electrodes 203 adjacent to each other are electrically separated from each other, and as shown in FIG. 39, even when the directions of the rod-shaped structure light emitting elements G adjacent to each other are reversed, the metal electrodes 203 through the metal electrodes 203. Short circuit between the 201 and the metal electrode 202 can be prevented.

[17th Embodiment]

40A to 40D are process charts showing the manufacturing method of the rod-shaped structure light emitting device according to the seventeenth embodiment of the present invention. In this embodiment, n-type GaN doped with Si and p-type GaN doped with Mg are used, but impurities doped in GaN are not limited thereto.

First, as shown in FIG. 40A, a mask (not shown) having growth holes is formed on a substrate 300 made of n-type GaN. As the mask, a material capable of selectively etching the semiconductor core and the semiconductor layer, such as silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ), may be used. Formation of a growth hole can use the well-known lithography method and the dry etching method used for a normal semiconductor process. At this time, the diameter of the growing semiconductor core depends on the size of the growth holes of the mask.

Subsequently, in the semiconductor core forming step, n-type GaN is crystal-grown by using a MOCVD (Metal Organic Chemical Vapor Deposition) device on the substrate 300 exposed by the growth hole of the mask to form a rod-shaped semiconductor core. 301 is formed. The growth temperature is set at about 950 ° C., trimethylgallium (TMG) and ammonia (NH ₃ ) are used as growth gases, silane (SiH ₄ ) is used for n-type impurity supply, and hydrogen (H ₂ ) is used as a carrier gas. By supplying, the n-type GaN semiconductor core 301 made of Si as an impurity can be grown. Here, the n-type GaN becomes hexagonal crystal growth, and a hexagonal pillar-shaped semiconductor core is obtained by growing with the c-axis direction perpendicular to the surface of the substrate 300.

Then, after the semiconductor core formation step, as a growth gas, and using TMG and NH _3, by using Cp ₂ Mg to for the p-type dopant supply to form a cap layer 302 made of p-type GaN on the semiconductor core (301) . The cap layer 302 adjusts the impurity concentration to a low concentration by the gas supply ratio, thereby making the electrical resistance larger than that of the subsequently formed semiconductor layer.

40B, in the quantum well layer and the semiconductor layer forming step, a quantum well layer made of p-type InGaN on the entire surface of the substrate 300 so as to cover the rod-shaped semiconductor core 301 and the cap layer 302 ( 303 is formed, and the semiconductor layer 304 is formed on the entire surface of the substrate 300. After growing the semiconductor core of n-type GaN as described above in the MOCVD apparatus, the set temperature was changed from 600 ° C. to 800 ° C. according to the emission wavelength, nitrogen (N ₂ ) in the carrier gas, TMG and NH in the growth gas. By supplying ₃ , trimethylindium (TMI), the InGaN quantum well layer 303 can be formed on the n-type GaN semiconductor core 301 and on the cap layer 302. Thereafter, the set temperature is 960 ° C, and as described above, TMG and NH ₃ are used as growth gases, and Cp ₂ Mg is used for p-type impurity supply, thereby making the semiconductor layer 304 made of p-type GaN. Can be formed.

The quantum well layer may also include a p-type AlGaN layer as an electron block layer between the InGaN layer and the p-type GaN layer. In addition, a multi-quantum well structure may be formed by alternately stacking a GaN barrier layer and an InGaN quantum well layer.

Next, as shown in FIG. 40C, in the exposure step, the region except for the portion covering the semiconductor core 301 of the quantum well layer 303 and the semiconductor layer 304 is removed by dry etching to form a rod-shaped semiconductor core 301. The exposed portion 301a is formed by exposing the outer circumferential surface of the substrate 300 side of the substrate 300, and a portion of the upper side of the cap layer 302 is also etched to expose the end surface of the cap layer 302a. In this case, by using SiCl ₄ for RIE of dry etching, etching can be easily performed with anisotropy in GaN.

Here, the outer circumferential surface of the semiconductor layer 304a and the outer circumferential surface of the exposed portion 301a of the semiconductor core 301 are continuous without a step (exposed portion of the outer circumferential surface of the quantum well layer 303a and exposed portion of the semiconductor core 301). 301a) has no step. Thus, when the fine rod-shaped structure light emitting element after separation is mounted on the insulating substrate on which the electrode is formed so that the axial direction is parallel to the substrate plane, the outer peripheral surface of the semiconductor layer 304a and the exposed portion of the semiconductor core 301 are separated. Since there is no step between the outer circumferential surface of 301a, the exposed portion 301a of the semiconductor core 301 and the electrode can be reliably and easily connected.

In the method for manufacturing a rod-shaped structure light emitting device according to the seventeenth embodiment, the cap layer 302 can be continuously grown on the semiconductor core 301 by changing the impurity gas, so that the cap layer 302 can be easily formed.

In addition, since the cap layer 302 is formed in the front-end | tip of the semiconductor core 301 at the time of engraving the board | substrate 300 in the exposure process shown in FIG. 40C, the upper end of the semiconductor core 301 is not exposed.

Subsequently, in the separation step, the semiconductor core is placed on the substrate 300 by immersing the substrate in an isopropyl alcohol (IPA) aqueous solution and vibrating the substrate 300 along the substrate plane using ultrasonic waves (for example, several tens of microseconds). Stress is applied to the semiconductor core 301 covered with the quantum well layer 303a and the semiconductor layer 304a so that the source close to the substrate 300 side of the 301 is bent, and as shown in FIG. 40D, the quantum well The semiconductor core 301 covered with the layer 303a and the semiconductor layer 304a is separated from the substrate 300.

In this way, the fine rod-shaped structure light emitting device H separated from the substrate 300 can be manufactured. In the seventeenth embodiment, the diameter of the rod-shaped structure light emitting element H is set to 1 μm and the length is 10 μm. [The length of the rod-shaped structure light emitting element H is shown in FIGS. 40A to 40D to make the drawing easy to see. Short.].

According to the manufacturing method of the rod-shaped structure light emitting element of the seventeenth embodiment, it is possible to realize the fine rod-shaped structure light emitting element H having a high luminous efficiency which can be easily connected to the electrode with a simple configuration.

Here, the fine rod-shaped light emitting device is, for example, a micro-order size having a diameter of 1 µm and a length of 10 µm to 30 µm, or a nano-order size having at least a diameter of less than 1 µm in diameter or length. In addition, the rod-shaped structured light emitting device can reduce the amount of semiconductors used, and it is possible to reduce the thickness and weight of the device using the light emitting device, and to provide high luminous efficiency, power saving light emitting device, backlight, lighting device and display device. Etc. can be realized.

In addition, according to the manufacturing method, the rod-shaped structure light emitting element H is not integral with the substrate, and the fine rod-shaped structure light emitting element H having high degree of freedom in mounting to the device can be manufactured. In addition, the rod-shaped structured light emitting device H can reduce the amount of semiconductors used, and it is possible to reduce the thickness and weight of the device using the light emitting device, and to provide light from the entire circumference of the semiconductor core covered with the semiconductor layer. Since the light emitting area is widened by emitting the light, the light emitting device, the backlight, the lighting device, the display device, and the like having high luminous efficiency and power saving can be realized.

[18th Embodiment]

41A to 41E are process charts showing the manufacturing method of the rod-shaped structure light emitting device according to the eighteenth embodiment of the present invention. In this embodiment, n-type GaN doped with Si and p-type GaN doped with Mg are used, but impurities doped in GaN are not limited thereto.

First, as shown in FIG. 41A, a mask 410 having growth holes 429A is formed on a substrate 400 made of n-type GaN. As the mask, a material capable of selectively etching the semiconductor core and the semiconductor layer, such as silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ), may be used. Formation of a growth hole can use the well-known lithography method and the dry etching method used for a normal semiconductor process. At this time, the diameter of the growing semiconductor core depends on the size of the growth holes 429A of the mask 410.

41B, n-type GaN is crystal-grown on the board | substrate 400 exposed by the growth hole 429A of the mask 410 in a semiconductor core formation process using a MOCVD apparatus, and rod-shaped semiconductor is carried out. The core 401 is formed. The growth temperature is set at about 950 ° C., trimethylgallium (TMG) and ammonia (NH ₃ ) are used as growth gases, silane (SiH ₄ ) is used for n-type impurity supply, and hydrogen (H ₂ ) is used as a carrier gas. By supplying, the n-type GaN semiconductor core 401 made of Si can be grown. Here, the n-type GaN becomes hexagonal crystal growth, and a hexagonal rod-shaped semiconductor core is obtained by growing in a c-axis direction perpendicular to the surface of the substrate 400.

Then, by using Cp ₂ Mg in the semiconductor core formation step Subsequently, using TMG and NH ₃ as a growth _gas, the p-type impurity supplied to the semiconductor core (401) forming a cap layer 402 made of p-type GaN . The cap layer 402 increases the electrical resistance than the semiconductor layer subsequently formed by adjusting the impurity concentration to a low concentration by the gas supply ratio.

Subsequently, as shown in FIG. 41C, in the quantum well layer and the semiconductor layer forming step, a quantum well layer made of p-type InGaN on the entire surface of the substrate 400 so as to cover the rod-shaped semiconductor core 401 and the cap layer 402 ( 403 is formed and a semiconductor layer 404 is formed over the entire surface of the substrate 400. After the n-type GaN semiconductor core 401 is grown in the MOCVD apparatus as described above, the set temperature is changed from 600 ° C. to 800 ° C. according to the emission wavelength, and nitrogen (N ₂ ) and carrier gas are added to the carrier gas. The InGaN quantum well layer 403 can be formed on the n-type GaN semiconductor core 401 by supplying TMG, NH ₃ and trimethylindium (TMI). Then, the semiconductor layer 125 made of p-type GaN by using Cp ₂ Mg in for using TMG and NH _3, and the p-type impurity provided as a growth gas, as a set temperature to 960 ℃ and above Can be formed.

The quantum well layer may also include a p-type AlGaN layer as an electron block layer between the InGaN layer and the p-type GaN layer. In addition, a multi-quantum well structure may be formed by alternately stacking a GaN barrier layer and an InGaN quantum well layer.

Subsequently, as shown in FIG. 41D, the area | region except the part which covers the semiconductor core 401 of the quantum well layer 403 and the semiconductor layer 404 by etching in an exposure process, and the mask 410 (shown in FIG. 41C) are shown. ) Is removed to expose the outer peripheral surface of the rod-shaped semiconductor core 401 on the substrate 400 side to form the exposed portion 401a. In this state, the end surface of the semiconductor core 401 opposite to the substrate 400 is covered by the quantum well layer 403a and the semiconductor layer 404a. When the mask is made of silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ), using a solution containing hydrofluoric acid (HF) does not easily affect the semiconductor core and the portion of the semiconductor layer covering the semiconductor core. The mask can be etched without removal, and the region except for the portion of the semiconductor layer covering the semiconductor core with the mask can be removed by lift off. In the exposure step of this embodiment, the mask can be easily etched without affecting the semiconductor core and the portion of the semiconductor layer covering the semiconductor core by dry etching using CF ₄ or XeF ₂ , and the semiconductor covering the semiconductor core together with the mask. The area except the part of the layer can be removed.

In the exposure step shown in FIG. 41D, even if the quantum well layer 403 and the semiconductor layer 404 on the tip side of the semiconductor core 401 are removed by etching, the cap layer 402 is formed, so that the semiconductor core 401 is formed. The top of is not exposed.

Subsequently, in the separation step, the semiconductor core is placed on the substrate 400 by immersing the substrate in an isopropyl alcohol (IPA) aqueous solution and vibrating the substrate 400 along the substrate plane using ultrasonic waves (for example, several tens of microseconds). Stress is applied to the semiconductor core 401 covered with the quantum well layer 403a and the semiconductor layer 404a so that the source close to the substrate 400 side of the 401 is bent, and as shown in FIG. 41E, the quantum well The semiconductor core 401 covered with the layer 403a and the semiconductor layer 404a is separated from the substrate 400.

In this way, the fine rod-shaped structure light emitting device I separated from the substrate 400 can be manufactured. In the eighteenth embodiment, the diameter of the rod-shaped structure light emitting element I is set to 1 μm and the length is 10 μm. [Fig. 41A to Fig. 41E, the length of the rod-shaped structure light emitting element I is made easy to see the drawing. Short.].

According to the manufacturing method of the rod-shaped structure light emitting device, it is possible to manufacture the fine rod-shaped structure light emitting device (I) having a high degree of freedom in mounting to the device. In addition, the rod-shaped structured light emitting device can reduce the amount of semiconductor used, and it is possible to reduce the thickness and weight of the device using the light emitting device, and to emit light from the entire circumference of the semiconductor core 401, thereby emitting light. As a result, the light emitting device, the backlight, the lighting device, the display device, and the like having high luminous efficiency and power saving can be realized.

[19th Embodiment]

42A to 42E are process charts showing the manufacturing method of the rod-shaped structure light emitting device according to the nineteenth embodiment of the present invention. In this embodiment, n-type GaN doped with Si and p-type GaN doped with Mg are used, but impurities doped in GaN are not limited thereto.

First, as shown in FIG. 42A, a semiconductor film 510 made of n-type GaN is formed on a base substrate 500, and a mask (not shown) having growth holes is formed on the semiconductor film 510. . As the mask, a material capable of selectively etching the semiconductor core and the semiconductor layer, such as silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ), may be used. Formation of a growth hole can use the well-known lithography method and the dry etching method used for a normal semiconductor process. At this time, the diameter of the growing semiconductor core depends on the size of the growth holes of the mask.

Next, in the semiconductor core forming step, n-type GaN is crystal-grown on the semiconductor film 510 exposed by the growth hole of the mask using a MOCVD apparatus to form a rod-shaped semiconductor core 501. The growth temperature is set at about 950 ° C., trimethylgallium (TMG) and ammonia (NH ₃ ) are used as growth gases, silane (SiH ₄ ) is used for n-type impurity supply, and hydrogen (H ₂ ) is used as a carrier gas. By supplying, the n-type GaN semiconductor core 501 made of Si can be grown. Here, the n-type GaN becomes hexagonal crystal growth, and a hexagonal pillar-shaped semiconductor core is obtained by growing in a c-axis direction perpendicular to the surface of the underlying substrate 500.

Then, after the semiconductor core formation step, as a growth gas, and using TMG and NH _3, by using Cp ₂ Mg to for the p-type dopant supply to form a cap layer 502 made of p-type GaN on the semiconductor core (501) . The cap layer 502 adjusts the impurity concentration to a low concentration by the gas supply ratio, thereby making the electrical resistance larger than that of the subsequently formed semiconductor layer. The cap layer 502 is not limited to p-type GaN, but may be another insulating material.

Subsequently, as shown in FIG. 42B, in the quantum well layer and the semiconductor layer forming step, a quantum well layer made of p-type InGaN on the entire surface of the substrate 500 so as to cover the rod-shaped semiconductor core 501 and the cap layer 502. 503 is formed, and a semiconductor layer 504 is formed over the entire surface of the base substrate 500. After growing the n-type GaN semiconductor core 501 in the MOCVD apparatus as described above, the set temperature is changed from 600 ° C. to 800 ° C. according to the emission wavelength, and nitrogen (N ₂ ) to the carrier gas and to the growth gas are changed. The InGaN quantum well layer 503 can be formed on the n-type GaN semiconductor core 501 by supplying TMG, NH ₃ and trimethylindium (TMI). Then, also the temperature of a 960 ℃ and, as described above, the semiconductor layer 504 made of p-type GaN by using Cp ₂ Mg in for using TMG and NH _3, and the p-type impurity provided as a growth gas set Can be formed.

The quantum well layer may also include a p-type AlGaN layer as an electron block layer between the InGaN layer and the p-type GaN layer. In addition, a multi-quantum well structure may be formed by alternately stacking a GaN barrier layer and an InGaN quantum well layer.

Next, as shown in FIG. 42C, in the exposure step, the region except for the portion covering the semiconductor core 501 of the quantum well layer 503 and the semiconductor layer 504 is removed by dry etching to form a rod-shaped semiconductor core 501. The exposed portion 501a is formed by exposing the outer circumferential surface of the base substrate 500 side of the substrate), and a part of the upper side of the cap layer 502 is also etched to expose the end surface of the cap layer 502a. In this case, by using SiCl ₄ for RIE of dry etching, etching can be easily performed with anisotropy in GaN.

Here, the outer circumferential surface of the semiconductor layer 504a and the outer circumferential surface of the exposed portion 501a of the semiconductor core 501 are continuous without a step (exposed portion of the outer circumferential surface of the quantum well layer 503a and exposed portion of the semiconductor core 501). 501a) has no step. Thereby, when mounting the fine rod-shaped structure light emitting element after separation so that the axial direction may become parallel to a board | substrate plane on the insulating substrate in which the electrode was formed, the outer peripheral surface of the semiconductor layer 504a and the exposed part of the semiconductor core 501 will be made. Since there is no step between the outer circumferential surfaces of 501a, the exposed portion 501a of the semiconductor core 501 and the electrode can be reliably and easily connected.

In the method for manufacturing a rod-shaped structure light emitting device according to the nineteenth embodiment, the cap layer 502 can be continuously grown on the semiconductor core 501 by changing the impurity gas, so that the cap layer 502 can be easily formed.

In addition, since the cap layer 502 is formed at the tip of the semiconductor core 501 when the underlying substrate 500 is etched in the exposure step shown in FIG. 42C, the upper end of the semiconductor core 501 is not exposed. .

Subsequently, as shown in FIG. 42D, the underlying substrate 500 is isotropically etched into the lower side of the semiconductor core 501, and the diameter of the tip of the convex portion 500a formed on the underlying substrate 500 is changed to the semiconductor core 501. Thinner than).

Subsequently, in the separation step, the convex portion 500a of the underlying substrate 500 is immersed in an isopropyl alcohol (IPA) aqueous solution, and the substrate 500 is vibrated along the substrate plane using ultrasonic waves (for example, several tens of microseconds). A stress acts on the quantum well layer 503a and the semiconductor core 501 covered with the semiconductor layer 504a so as to bend the semiconductor core 501 to be placed on the top, and as shown in FIG. 42E, the quantum well layer The semiconductor core 501 covered with the 503a and the semiconductor layer 504a is separated from the substrate 500.

In this way, the fine rod-shaped structure light emitting device J separated from the base substrate 500 can be manufactured. In the nineteenth embodiment, the diameter of the rod-shaped structure light emitting element J is set to 1 μm and the length is 10 μm. [Fig. 42A to Fig. 42E, the length of the rod-shaped structure light emitting element J is made easy to see the drawing. Short.].

According to the manufacturing method of the rod-shaped structure light emitting element of the said 19th embodiment, the fine rod-shaped structure light emitting element J with high light emission efficiency which can be easily connected to an electrode by a simple structure can be implement | achieved.

Moreover, according to the manufacturing method of the rod-shaped structure light emitting element, the fine rod-shaped structure light emitting element J with high degree of freedom of mounting to an apparatus can be manufactured. In addition, the rod-shaped structure light emitting device J can reduce the amount of semiconductors to be used, and it is possible to reduce the thickness and weight of the device using the light emitting device, and to provide light from the entire circumference of the semiconductor core covered with the semiconductor layer. Since the light emitting area is widened by emitting the light, the light emitting device, the backlight, the lighting device, the display device, and the like having high luminous efficiency and power saving can be realized.

In addition, according to the method of manufacturing the rod-shaped light emitting device, when the semiconductor core 501 is separated from the substrate 500, the folding position is stable and a rod-shaped light emitting device having a more uniform length can be formed.

In the tenth to nineteenth embodiments, a semiconductor based on GaN is used for the semiconductor core, the cap layer, and the semiconductor layer, but the semiconductor based on GaAs, AlGaAs, GaAsP, InGaN, AlGaN, Ga P, ZnSe, AlGaInP, etc. You may apply this invention to the light emitting element which used. In addition, although the semiconductor core is n-type and the semiconductor layer is p-type, you may apply this invention to the rod-shaped structure light emitting element whose electroconductive type is the opposite. Moreover, although the rod-shaped structure light emitting element which has a hexagonal pillar-shaped semiconductor core was demonstrated, it is not limited to this, The cross-section may be circular or oval rod-shaped, and the cross-section is rod-shaped semiconductor which is another polygonal shape, such as a triangle. You may apply this invention to the rod-shaped structure light emitting element which has a core.

In the tenth to nineteenth embodiments, the rod-shaped structure light emitting device had a diameter of 1 µm and a micro order size of 10 µm to 30 µm in length, but at least the diameter or length of the nano order size of less than 1 µm. An element may be sufficient. The diameter of the semiconductor core of the rod-shaped structure light emitting device is preferably 500 nm or more and 100 μm or less, and the variation in the diameter of the semiconductor core can be suppressed as compared to the rod-shaped structure light emitting device of several tens of nm to several hundred nm. The deviation of the luminescence properties can be reduced and the yield can be improved.

Further, in the seventeenth to nineteenth embodiments, the semiconductor cores 301, 401, 501 and the cap layers 302, 402, 502 were grown by using a MOCVD device, but the semiconductor core and the cap layer were formed by using another crystal growth device such as a molecular beam epitaxial (MBE) device. May be formed. In addition, although the semiconductor core is crystal-grown on the substrate using a mask having growth holes, the semiconductor core may be crystal-grown from the metal species by disposing a metal species on the substrate.

In the seventeenth to nineteenth embodiments, the semiconductor cores 301, 401, and 501 are separated from the substrate by using ultrasonic waves. However, the semiconductor cores 301, 401, and 501 are separated from the substrate by using a cutting tool. In this case, a plurality of fine rod-shaped structure light emitting elements provided on the substrate can be separated in a short time by a simple method.

[20th Embodiment]

Fig. 43 shows a perspective view of a rod-shaped structure light emitting element of the twentieth embodiment of the present invention, and Fig. 44 shows a cross-sectional view of the rod-shaped structure light emitting element.

As shown in Figs. 43 and 44, the rod-shaped structure light emitting element A2 of the twentieth embodiment includes a semiconductor core 211 made of rod-shaped n-type GaN having a substantially circular cross section, and the semiconductor core 211. Is provided with a semiconductor layer 212 made of p-type GaN that covers the cover portion 211b other than the exposed portion 211a of the semiconductor core 211 so as to be the exposed portion 211a without covering the one end side portion of the semiconductor substrate 211. . The semiconductor core 211 forms the stepped portion 211c between the outer circumferential surface of the exposed portion 211a and the outer circumferential surface of the coated portion 211b with the exposed portion 211a having a diameter smaller than that of the coated portion 211b. The end surface of the other end side of the semiconductor core 211 is covered by the semiconductor layer 212.

The rod-shaped structure light emitting device A2 is manufactured as follows.

First, a mask having growth holes is formed on a substrate made of n-type GaN. As the mask, a material capable of selectively etching the semiconductor core 211 and the semiconductor layer 212, such as silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ), is used. Formation of a growth hole can use the well-known lithography method and the dry etching method used for a normal semiconductor process.

A catalyst metal layer is then formed on the substrate exposed by the growth holes in the mask. The catalyst metal layer has a catalyst metal layer of 200 on the substrate exposed from the resist and the growth holes (on the exposed areas of the growth holes) with the resist used to form the growth holes on the mask by the lithography method and the dry etching method. It deposits about nm-400 nm, and is formed by removing the catalyst metal layer on a resist with the said resist by the lift-off method. As the catalyst metal layer, materials such as Ni, Fe, Au, etc. which are obtained by dissolving these in a compound semiconductor material such as Ga, N, In, Al, and impurities such as Si, Mg, and which do not form a compound with itself can be used. .

Subsequently, a rod-shaped semiconductor core is formed by crystal-growing n-type GaN from the interface between the catalyst metal layer and the substrate using a MOCVD (Metal 0rganic Chemical Vapor Deposition) device on the substrate on which the catalyst metal layer is formed in the growth hole of the mask. Form 211. The temperature of the MOCVD apparatus is set at about 950 ° C., trimethylgallium (TMG) and ammonia (NH ₃ ) are used as growth gases, silane (SiH ₃ ) is used for n-type impurity supply, and hydrogen (H _{3 is used} as a carrier gas. ), An n-type GaN semiconductor core containing Si as an impurity can be grown. At this time, the diameter of the growing semiconductor core 211 is determined by the inner diameter of the growth hole because the diameter of the catalyst metal layer is not wider than the inner diameter of the growth hole in the growth hole of the mask, but the growing semiconductor core 211 After the height exceeds the height (depth of the growth hole) of the mask, it can be determined by the diameter of the catalyst metal layer that aggregates in an island shape. Therefore, when the catalyst metal layer is formed with the above film thickness, since the height of the growing semiconductor core 211 exceeds the height of the mask (depth of the growth hole), it is aggregated in an island shape with a diameter larger than that of the growth hole. The coating portion 211b of the semiconductor core 211 may be grown to a diameter larger than the diameter of the exposed portion 211a of the semiconductor core 211.

Subsequently, a semiconductor layer made of p-type GaN is formed on the entire surface of the substrate so as to cover the rod-shaped semiconductor core 211 while the island-like catalyst metal layer is held at the tip of the semiconductor core 211. The temperature of the MOCVD apparatus was set to about 960 ° C, and trimethylgallium (TMG) and ammonia (NH ₃ ) were used as the growth gases, and biscyclopentadienyl magnesium (Cp ₂ Mg) was used to supply p-type impurities. P-type GaN can be grown as an impurity.

Subsequently, the island-like catalyst metal layer is removed, and a portion of the semiconductor layer except for the portion covering the semiconductor core is removed by removing the island, and the outer peripheral surface of the rod-shaped semiconductor core 211 is exposed to expose the exposed portion. Form. In this state, the end surface on the side opposite to the substrate of the semiconductor core 211 is covered by the semiconductor layer 212, and the exposed portion 211a having a smaller diameter than the covering portion 211b of the semiconductor core 211 is provided. Is formed.

When the mask is made of silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ), by using a solution containing hydrofluoric acid (HF), the semiconductor core and the portion of the semiconductor layer covering the semiconductor core are easily affected. The mask can be etched without giving, and the area except the portion of the semiconductor layer covering the semiconductor core on the mask with the mask can be removed by lift off. In this embodiment, the length of the exposed portion 211a of the semiconductor core 211 is determined by the film thickness of the removed mask. Although the lift-off was used in the exposure process of this embodiment, you may expose a part of semiconductor core by etching.

Subsequently, the source close to the substrate side of the semiconductor core 211, which is erected on the substrate by immersing the substrate in an isopropyl alcohol (IPA) aqueous solution and vibrating the substrate along the substrate plane using ultrasonic waves (for example, several tens of microseconds), is bent. Stress is applied to the semiconductor core 211 covered by the semiconductor layer 212 so that the semiconductor core 211 covered by the semiconductor layer 212 is separated from the substrate.

In this way, a fine rod-shaped structure light emitting element separated from the substrate made of n-type GaN can be manufactured.

In addition, although the said semiconductor core was isolate | separated from the board | substrate using ultrasonic wave, it is not limited to this, You may isolate | separate by mechanically bending a semiconductor core from a board | substrate using a cutting tool. In this case, a plurality of fine rod-shaped structure light emitting elements provided on the substrate can be separated in a short time by a simple method.

In addition, the rod-shaped structure light emitting device is a semiconductor having fewer crystal defects because the semiconductor layer 212 crystal grows radially outward from the outer circumferential surface of the semiconductor core 211, the growth distance in the radial direction is short and defects are avoided outward. The semiconductor core 211 may be covered by the layer 212. Therefore, a rod-shaped structure light emitting device having good characteristics can be realized.

According to the rod-shaped structure light emitting element A2 having the above structure, the exposed portion 211a of the semiconductor core 211 is formed so as to be an exposed portion 211a without covering a portion of one end side of the rod-shaped n-type semiconductor core 211. The covering portion 211b of the semiconductor core 211 is covered by the p-type semiconductor layer 212 so that the exposed portion 211a of the semiconductor core 211 can be exposed to the n-side electrode. The p-side electrode can be connected to a portion of the semiconductor layer 212 that is connected to and covers the semiconductor core 211. The rod-shaped structure light emitting element A2 connects the n-side electrode to the exposed portion 211a of the semiconductor core 211 and the p-side electrode to the semiconductor layer 212 to transfer current from the p-side electrode to the n-side electrode. By flowing, recombination of electrons and holes occurs at an interface (pn junction) between the outer circumferential surface of the semiconductor core 211 and the inner circumferential surface of the semiconductor layer 212, thereby emitting light. In the rod-shaped structure light emitting device A2, light is emitted from the entire side surface of the semiconductor core 211 covered with the semiconductor layer 212, so that the light emitting area is widened, so that the light emitting efficiency is high.

Therefore, a fine rod-shaped structure light emitting element A2 having a high luminous efficiency which can be easily connected to electrodes with a simple configuration can be realized. Further, since the rod-shaped structure light emitting element A2 is not integral with the substrate, the degree of freedom in mounting to the device is high.

Here, the fine rod-shaped light emitting device is, for example, a micro-order size having a diameter of 1 µm and a length of 10 µm to 30 µm, or a nano-order size having at least a diameter of less than 1 µm in diameter or length. In addition, the rod-shaped structured light emitting device can reduce the amount of semiconductors used, and it is possible to reduce the thickness and weight of the device using the light emitting device, and to provide high luminous efficiency, power saving light emitting device, backlight, lighting device and display device. Etc. can be realized.

In addition, one n-side electrode is connected to the exposed portion 211a of the outer circumferential surface of one end of the semiconductor core 211 by exposing the outer circumferential surface of the one end of the semiconductor core 211 to about 1 μm to 5 μm, for example. The p-side electrode can be connected to the semiconductor layer 212 on the other end side of the semiconductor core 211, and the electrodes can be connected by separating the electrodes at both ends, and the p-side electrode and the semiconductor connected to the semiconductor layer 212 can be connected. The short-circuiting of the exposed part 211a of the core 211 can be prevented.

45 is a sectional schematic diagram of principal parts of a rod-shaped light emitting device of Comparative Example, and is not a rod-shaped light emitting device of the present invention. The rod-shaped structure light emitting element of FIG. 45 differs from the rod-shaped structure light emitting element A2 shown in FIGS. 43 and 44 of the twentieth embodiment in that the outer circumferential surface of the exposed portion of the semiconductor core 1211 and the semiconductor core 1211 are different. There is no step between the covered portions covered by the semiconductor layer 1212.

In the rod-shaped structure light emitting device, when the n-side electrode is connected to the exposed portion of the semiconductor core 1211, there is no stepped portion, so that the distance L between the n-side electrode 1213 and the end surface of the semiconductor layer 1212 is close to the n-side. There is a possibility that a short circuit or a leakage current is generated between the electrode 1213 and the semiconductor layer 1212. In this rod-shaped light emitting device, as shown in FIG. 45, light having a large incident angle from the inside of the semiconductor core 1211 to the outer circumferential surface of the exposed portion is hardly reflected in the semiconductor core 1211 and drawn out to the outside.

On the other hand, as shown in the cross-sectional schematic diagram of FIG. 46, in the rod-shaped structure light emitting elements shown in FIGS. 43 and 44 of the twentieth embodiment, as shown in FIG. 46, the semiconductor layer of the semiconductor core 211 ( The semiconductor core 211 is exposed by forming a stepped portion 211c between the outer circumferential surface of the exposed portion 211a not covered with 212 and the outer circumferential surface of the coated portion covered with the semiconductor layer 212 of the semiconductor core 211. The stepped portion formed at the boundary between the exposed portion 211a of the semiconductor core 211 and the semiconductor layer 212 as compared with the comparative example of FIG. 45 where the outer circumferential surface of the portion 211a and the outer circumferential surface of the covering portion 211b do not have a step. The position of the end surface of the semiconductor layer 212 is determined by (211c), and the deviation of the boundary position at the time of manufacture can be suppressed. As shown in the comparative example of FIG. 45, when the outer circumferential surface of the exposed portion of the semiconductor core and the outer circumferential surface of the coated portion do not coincide with each other, there is a possibility that a gap is formed between the inner wall of the growth hole of the mask and the semiconductor core during growth of the semiconductor core. When the semiconductor layer is subsequently formed, the semiconductor layer is also formed in the gap region between the inner wall of the growth hole of the mask and the semiconductor core, and the boundary between the exposed part of the semiconductor core defined at the position of the upper surface of the mask and the covering part is disturbed. There is a case. On the other hand, when there is a step | step in the outer peripheral surface of the exposed part of a semiconductor core, and the outer peripheral surface of a coating | coating part like the 20th embodiment shown in FIG. 46, a diameter larger than the inner diameter of a growth hole after exceeding the height of a mask at the time of manufacture In order to grow the semiconductor core, the semiconductor core grows so as to close the gap even if a gap is formed between the inner wall of the mask growth hole and the semiconductor core. Can be prevented. In FIG. 46, even if the distance between the n-side electrode 213 and the end surface of the semiconductor layer 212 in the longitudinal direction is the same, only the step portion 211c is widened in the radial direction.

In addition, an outer circumferential surface of the exposed portion 211a of the semiconductor core 211 and a semiconductor layer are formed by a stepped portion 211c formed between the outer circumferential surface of the exposed portion 211a of the semiconductor core 211 and the outer circumferential surface of the covering portion 211b. Since the distance of 212 can be extended, when the n-side electrode is connected to the exposed part 211a of the semiconductor core 211, the generation of a short circuit or leakage current between the n-side electrode and the semiconductor layer 212 can be suppressed. have. In addition, since light is easily drawn out from the stepped portion 211c formed at the boundary between the outer circumferential surface of the exposed portion 211a of the semiconductor core 211 and the outer circumferential surface of the covering portion 211b, the light extraction efficiency is improved.

Fig. 47 is a sectional view showing the main parts of a modification of the rod-shaped structure light emitting device of the twentieth embodiment.

In the rod-shaped light emitting device of this modified example, the semiconductor core 215 has a stepped portion between the outer circumferential surface of the exposed portion 215a and the outer circumferential surface of the coated portion 215b with the exposed portion 215a having a larger diameter than the covered portion 215b. 215c is formed. The n-side electrode 217 is connected to the exposed portion 215a of the semiconductor core 215.

As shown in FIG. 47, the step portion 215c is formed at the boundary between the outer circumferential surface of the exposed portion 215a of the semiconductor core 215 and the outer circumferential surface of the covering portion 215b, so that the light extraction efficiency to the outside is improved. In addition, since the diameter of the exposed portion 215a is larger than the covering portion 215b of the semiconductor core 215, the contact surface with the n-side electrode 217 connected to the exposed portion 215a of the semiconductor core 215 is larger. Is taken to lower the contact resistance.

Further, according to the rod-shaped structure light emitting element A2 of the twentieth embodiment, the exposed portion 211a of the semiconductor core 211 is larger than the outer circumferential length of the cross section orthogonal to the longitudinal direction of the covering portion 211b of the semiconductor core 211. Is formed so as to stand on the substrate in the manufacturing process by shortening the outer circumferential length of the cross section orthogonal to the longitudinal direction of i.e., that is, the exposed portion 211a is smaller in diameter than the covering portion 211b of the semiconductor core 211. By forming the exposed part 211a of the semiconductor core 211 at the board | substrate side, the semiconductor core 211 becomes easy to be folded and manufacture becomes easy. As described above, the semiconductor core 211 is separated from the substrate by vibrating by ultrasonic waves in IPA, but the exposed portion 211a of the semiconductor core 211 is thinned to facilitate separation.

In addition, the exposed portion 211a of the semiconductor core 211 becomes the low side (high side of the semiconductor layer 212 side) by the stepped portion 211c, so that the outer circumferential surface of the exposed portion 211a of the semiconductor core 211 is formed. Since the distance between the semiconductor layer 212 and the semiconductor layer 212 can be increased, when the n-side electrode is connected to the exposed portion 211a of the semiconductor core 211, the occurrence of a short circuit or leakage current between the n-side electrode and the semiconductor layer 212 is prevented. It can be suppressed.

The cross sections of each of the exposed portion 211a and the covering portion 211b of the semiconductor core 211 are not limited to a circular shape, and may be a cross-sectional shape of another polygon such as a hexagon, or a semiconductor core. The cross-sectional shape different from an exposed part may be sufficient as it, and if the exposed part 211a is smaller in diameter than the covered part 211b of the semiconductor core 211, it will have the same effect.

In addition, since the cross section orthogonal to the longitudinal direction of the exposed part 211a of the said semiconductor core 211 is substantially circular shape, the shape of the mask pattern used at the time of the growth of the semiconductor core 211 in a manufacturing process may be circular. The manufacturing process can be facilitated because the alignment of the mask is not limited by the alignment of the mask in alignment with the crystal orientation in the planar direction of the substrate, and the alignment precision for aligning the orientation is unnecessary.

Fig. 48 is a sectional view of the main portion for explaining the electrode connection of the exposed portion of the semiconductor core of the rod-shaped structure light emitting element A2, and the rod-shaped structure light emitting element A2 is arranged so that the longitudinal direction thereof is parallel to the mounting surface. In addition to being mounted on the substrate 210, the exposed portion 211a of the semiconductor core 211 is connected to the n-side electrode 14 formed on the substrate 210.

As shown in FIG. 48, in the coating part 211b covered by the semiconductor layer 212 of the semiconductor core 211, the outer side of the exposed part 211a of the semiconductor core 211 rather than the outer shape of the semiconductor layer 212 is shown. Since the size becomes small, when the rod-shaped structure light emitting element is mounted on the substrate 210 so that the longitudinal direction thereof is parallel to the substrate plane, the outer peripheral surface of the semiconductor layer 212 is easily brought into contact with the substrate 210, so that the heat dissipation efficiency is improved. do. That is, since the exposed portion 211a of the semiconductor core 211 is thin, it is deformed and connected to the n-side electrode 14 well, and the covering portion 211b covered by the semiconductor layer 212 of the semiconductor core 211 is covered. Since it can be in close contact with the substrate 210 without being deformed, it is excellent in heat dissipation. On the other hand, when the outer circumferential surface of the exposed portion 211a of the semiconductor core 211 and the outer circumferential surface of the covering portion 211b covered by the semiconductor layer 212 coincide, or the outer shape of the exposed portion 211a of the semiconductor core 211 When larger than the outer shape of the covering portion 211b covered by the semiconductor layer 212, the exposed portion 211a of the semiconductor core 211 is difficult to deform. Therefore, when the exposed portion 211a of the semiconductor core 211 is connected to the n-side electrode 14, the covering portion 211b covered by the semiconductor layer 212 of the semiconductor core 211 is deformed to form the substrate 210. ), The heat dissipation is deteriorated.

In the twentieth embodiment, the rod-shaped structure light emitting device A2 is described in which the semiconductor layer 212 is covered with a rod-shaped semiconductor core 211 having a substantially circular cross section. For example, a rod-shaped rod of a hexagon or another polygon is described. You may apply this invention to the rod-shaped structure light emitting element which coat | covered a semiconductor layer, a quantum well layer, etc. to a semiconductor core. The n-type GaN becomes hexagonal crystal growth, and grows in a c-axis direction perpendicular to the substrate surface to obtain a substantially hexagonal columnar semiconductor core. Depending on growth conditions such as growth direction and growth temperature, when the diameter of the semiconductor core to be grown is small, about tens of nm to hundreds of nm, the cross-section tends to be almost circular in shape, and the diameter is about 0.5 μm. If the thickness is increased to several micrometers, the cross section may be easily grown in a hexagon.

[21st Embodiment]

Fig. 49 shows a perspective view of the rod-shaped structure light emitting device of the twenty-first embodiment of the present invention.

As shown in FIG. 49, the rod-shaped structure light emitting element B2 of the twenty-first embodiment has a semiconductor core 221 made of rod-shaped n-type GaN having a substantially hexagonal cross section, and one end of the semiconductor core 221. The semiconductor layer 222 which consists of p-type GaN which covers the covering part 221b other than the exposed part 221a of the semiconductor core 221 so that it may become the exposed part 221a is not provided. The semiconductor core 221 forms the stepped portion 221c between the outer circumferential surface of the exposed portion 221a and the outer circumferential surface of the coated portion 221b with the exposed portion 221a having a diameter smaller than that of the coated portion 221b. The end surface of the other end side of the semiconductor core 221 is covered by the semiconductor layer 222.

The rod-shaped structure light emitting element B2 is manufactured by the same method as the rod-shaped structure light emitting element A2 of the twentieth embodiment.

FIG. 50 shows a schematic cross-sectional view of the main parts of the rod-shaped structure light emitting device of the twenty-first embodiment, and in FIG. 50, 223 is an n-side electrode.

The rod-shaped structure light emitting element B2 of the twenty-first embodiment has the same effect as the rod-shaped structure light emitting element A2 of the twentieth embodiment.

According to the rod-shaped structure light emitting element B2 of the twenty-first embodiment, the cross section orthogonal to the longitudinal direction of the covering portion 221b of the semiconductor core 221 has a hexagonal shape so that the rod-shaped structure light emitting element is formed on the substrate. When mounting so that a longitudinal direction may become parallel with a plane, even if it is any outer peripheral surface of a semiconductor layer, a contact surface with a board | substrate will be easy to be obtained, and the heat radiation efficiency to a board | substrate will improve. Therefore, it can suppress that the element temperature at the time of light emission rises and light emission efficiency falls.

51A shows a cross-sectional schematic diagram of an exposed portion of a semiconductor core of rod-shaped structure light emitting element A2 of the twentieth embodiment, and FIG. 51B shows a semiconductor core of the rod-shaped structure light emitting element B2 of the twenty-first embodiment. The schematic diagram of the exposed part is shown.

51C shows a cross-sectional schematic diagram of an exposed portion of a semiconductor core of a rod-shaped structure light emitting element of the modification, and is perpendicular to the longitudinal direction of the exposed portion 224a of the semiconductor core 224 in the rod-shaped structure light emitting element of this modification. The cross section is made into an equilateral triangle.

In this way, the polygonal cross section (for example, a regular hexagon shown in FIG. 51B and an equilateral triangle shown in FIG. 51C) can improve light extraction efficiency in a cross section orthogonal to the longitudinal direction of the exposed portion of the semiconductor core. The reason for this is that the cross section of the exposed portion of the semiconductor core is more easily emitted to the outside of the polygon with fewer vertices.

[22nd Embodiment]

52 is a perspective view of a rod-shaped structure light emitting device of a twenty-second embodiment of the present invention.

As shown in FIG. 52, the rod-shaped structure light emitting element C2 of the twenty-second embodiment does not cover a semiconductor core 231 made of rod-shaped n-type GaN and a portion of one end side of the semiconductor core 231. The semiconductor layer 232 which consists of p-type GaN which covers the covering part 231b other than the exposed part 231a of the semiconductor core 231 so that it may become the exposed part 231a is provided. The exposed portion 231a of the semiconductor core 231 has a substantially rectangular cross section perpendicular to the longitudinal direction, and the covering portion 231b of the semiconductor core 231 has a substantially hexagonal cross section perpendicular to the longitudinal direction. A stepped portion 231c is formed between the outer circumferential surface of the exposed portion 231a of the semiconductor core 231 and the outer circumferential surface of the covering portion 231b. The end surface of the other end side of the semiconductor core 231 is covered by the semiconductor layer 232.

The rod-shaped structure light emitting element C2 is manufactured by the same method as the rod-shaped structure light emitting element A2 of the twentieth embodiment except for the covering portion of the semiconductor core. Here, as for the shape of the exposed portion 231a of the semiconductor core 231, as described above, the diameter of the semiconductor core 231 growing in the diameter and shape of the growth hole until the height of the growth hole of the mask is exceeded. And the shape is determined, and the diameter of the catalyst metal layer that aggregates in an island shape after the height of the growing semiconductor core 231 exceeds the height of the mask is determined. In the twenty-second embodiment, a rectangular growth hole is used.

The rod-shaped structure light emitting element C2 of the twenty-second embodiment has the same effect as the rod-shaped structure light emitting element A2 of the twentieth embodiment.

Fig. 53 shows a cross-sectional schematic diagram of the first modification of the rod-shaped structure light emitting device of the twenty-second embodiment. In this first modification, the exposed portion 1231a of the semiconductor core 1231 has a substantially circular cross section perpendicular to the longitudinal direction, and the covering portion 1231b of the semiconductor core 1231 has a substantially hexagonal cross section perpendicular to the longitudinal direction. to be. The cross-sectional shape of the exposed portion 1231a of the semiconductor core 1231 is larger than the cross-sectional shape of the covering portion 1231b. A step portion 1231c is formed between the outer circumferential surface of the exposed portion 1231a of the semiconductor core 1231 and the outer circumferential surface of the covering portion 1231b.

Fig. 54 shows a cross-sectional schematic diagram of a second modification of the rod-shaped structure light emitting device of the twenty-second embodiment. In this second modification, the cross section orthogonal to the longitudinal direction of the exposed portion 1241a is almost circular, and the cross section orthogonal to the longitudinal direction of the covering portion 1241b is almost hexagonal. The outer peripheral length of the cross section orthogonal to the longitudinal direction of the exposed portion 1241a of the semiconductor core 1241 is shorter than the outer peripheral length of the cross section orthogonal to the longitudinal direction of the covering portion 1241b of the semiconductor core 1241. That is, the cross-sectional shape of the exposed part 1231a of the said semiconductor core 1231 is smaller than the cross-sectional shape of the coating part 1231b. A step portion 1241c is formed between the outer circumferential surface of the exposed portion 1241a of the semiconductor core 1241 and the outer circumferential surface of the covering portion 1241b.

Thus, in the rod-shaped structure light emitting device shown in FIGS. 52 to 54, the shape of the cross section orthogonal to the longitudinal direction of the exposed portions 231a, 1231a and 1241a of the semiconductor cores 231, 1231 and 1241 and the semiconductor core 231 is shown. The outer circumferential surface and the outer peripheral surface of the exposed portions 231a, 1231a and 1241a of the semiconductor cores 231, 1231 and 1241 are different due to the different shape of the cross section orthogonal to the longitudinal direction of the coated portions 231b, 1231b and 1241b of the .1231 and 1241b. The stepped portions 231c, 1231c, 1241c are formed at the boundary of the outer circumferential surface of the portions 231b, 1231b, 1241b, and the light extraction efficiency to the outside is improved.

In addition, the exposed portions 231a, 1231a, 1241a and the semiconductor layers 232, 1232 of the semiconductor cores 231, 1231, 1241 and the semiconductor layers 232, 1232 compare to the case where the outer peripheral surface of the exposed portion of the semiconductor core and the outer peripheral surface of the coated portion do not have a step difference. The positions of the end faces of the semiconductor layers 232, 1232 and 1242 are determined by the stepped portions 231c, 1231c and 1241c formed at the boundary of 1242 so that the deviation of the boundary position at the time of manufacture can be suppressed. If the outer circumferential surface of the exposed portion of the semiconductor core coincides with the outer circumferential surface of the coated portion and there is no step, there is a fear that a gap is formed between the inner wall of the growth hole of the mask and the semiconductor core during the growth of the semiconductor core. Although the semiconductor layer is also formed in the gap region of the growth hole inner wall of the mask and the semiconductor core when performing the process, the boundary between the exposed portion of the semiconductor core and the covering portion may be disturbed at the position of the upper surface of the mask, but the semiconductor core is exposed. If there is a step between the outer circumferential surface of the portion and the outer circumferential surface of the coating portion, the gap is formed between the inner wall of the growth hole of the mask and the semiconductor core because the semiconductor core is grown at a diameter larger than the inner diameter of the growth hole after the height of the mask is exceeded in manufacturing. Although the semiconductor core grows so as to close the gap even though it is formed, The semiconductor layer can be prevented from being formed in the gap region of the growth mask hole inner wall and the semiconductor core.

[23rd Embodiment]

55 is a sectional view showing a rod-shaped structure light emitting device according to a twenty-third embodiment of the present invention, and FIG. 56 shows a perspective view of the rod-shaped structure light emitting device.

As shown in FIGS. 55 and 56, the rod-shaped structure light emitting device D2 of the twenty-third embodiment includes a semiconductor core 241 made of rod-shaped n-type GaN having a substantially hexagonal cross section, and the semiconductor core 241. Is provided with a semiconductor layer 242 made of p-type GaN that covers the covering portion 241b other than the exposed portion 241a of the semiconductor core 241 so as to be the exposed portion 241a without covering the portion on one end side thereof. . The semiconductor core 241 forms the stepped portion 241c between the outer circumferential surface of the exposed portion 241a and the outer circumferential surface of the coated portion 241b with the exposed portion 241a having a diameter smaller than that of the coated portion 241b. In addition, the end surface of the other end side of the semiconductor core 241 is covered by the semiconductor layer 242.

The stepped portion 241c of the semiconductor core 241 and the stepped portion 241a of the exposed portion 241a of the semiconductor core 241 are covered to cover the end surface of the semiconductor layer 242 on the side of the stepped portion 241c. The insulating layer 243 is formed so that the 241c side may be covered. The n-side electrode 244 is connected to the exposed portion 241a of the semiconductor core 241.

The rod-shaped structure light emitting element D2 is manufactured by the same method as the rod-shaped structure light emitting element A2 of the twentieth embodiment except for the covering portion of the semiconductor core. Here, the stepped portion 241c of the semiconductor core 241 and the end surface of the semiconductor layer 242 on the side of the stepped portion 241c are covered, and the stepped portion 241 of the exposed portion 241a of the semiconductor core 241 is covered. For the formation of the insulating layer 243 covering the side of 241c, in the manufacturing process of the rod-shaped structure light emitting device A2 of the twentieth embodiment, the region and the mask except for the portion of the semiconductor layer covering the semiconductor core are lifted off. Instead of the removal, first, anisotropic dry etching is performed, and the mask and the region except for the portion covering the semiconductor core in the semiconductor layer are etched. The mask can be partially left as an insulating layer by performing etching by switching to isotropic dry etching in the step of etching the mask to the middle.

When the mask is made of silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ )), an anisotropic dry etching is performed using a chlorine-based gas such as SiCl ₄ or a fluorine-based gas such as CF ₄ or CHF ₃ . (Reactive Ion Etching) can be used, and can be etched by using a plasma of a gas containing CF ₄ for isotropic dry etching. In this embodiment, the length of the insulating layer 243 is determined by the film thickness of the mask removed by dry etching. In the anisotropic dry etching process, etching is performed while using a gas containing SiCl ₄ and forming a protective film of the reaction product on the sidewall of the mask. The process which made the outer peripheral surface and the outer peripheral surface of the insulating layer 243 substantially match can be performed.

The rod-shaped structure light emitting element D2 of the twenty-third embodiment has the same effect as the rod-shaped structure light emitting element A2 of the twentieth embodiment.

In the rod-shaped structure light emitting device D2, the insulating layer 243 may insulate the outer circumferential surface of the exposed portion 241a of the semiconductor core 241 with the insulating layer 243. When the n-side electrode 244 is connected to the exposed portion 241a, the occurrence of a short circuit or leakage current between the n-side electrode 244 and the semiconductor layer 242 can be reliably suppressed.

[24th Embodiment]

Fig. 57 is a sectional view of a rod-shaped structure light emitting element of the twenty-fourth embodiment of the present invention, and Fig. 58 is a perspective view of the rod-shaped structure light emitting element.

57 and 58, the rod-shaped structure light emitting element E2 of the twenty-fourth embodiment includes a semiconductor core 251 made of rod-shaped n-type GaN having a substantially hexagonal cross section, and the semiconductor core 251. Is provided with a semiconductor layer 252 made of p-type GaN that covers the covering portion 251b other than the exposed portion 251a of the semiconductor core 251 so as to be the exposed portion 251a without covering the portion on one end side thereof. .

The exposed portion 251a of the semiconductor core 251 is connected to the small diameter portion 251a-1 on the side of the stepped portion 251c having a diameter smaller than that of the covering portion 251b and the small diameter portion 251a-1. It has a larger diameter than the portion 251b and has a large diameter portion 251a-2 having the same outer diameter as the semiconductor layer 252. The semiconductor core 251 has a stepped portion between the outer circumferential surface of the exposed portion 251a and the outer circumferential surface of the coated portion 251b by making the small diameter portion 251a-1 of the exposed portion 251a smaller than the covering portion 251b. 251c is formed. In addition, the end surface of the other end side of the semiconductor core 251 is covered by the semiconductor layer 252.

The small diameter portion 251a of the exposed portion 251a of the semiconductor core 251 may be covered to cover the stepped portion 251c of the semiconductor core 251 and the end surface of the semiconductor layer 252 on the side of the stepped portion 251c. The insulating layer 253 is formed to cover the 251a-1) side. The n-side electrode 254 is connected to the large diameter portion 251a-2 of the exposed portion 251a of the semiconductor core 251.

The rod-shaped structure light emitting element E2 is manufactured by the same method as the rod-shaped structure light emitting element A2 of the twentieth embodiment except for the covering portion of the semiconductor core. In the rod-shaped structure light emitting element E2, the small diameter portion 251a-1 on the side of the stepped portion 251c having a smaller diameter than the covering portion 251b is connected to the small diameter portion 251a-1, and the covering portion 251b is connected to the small diameter portion 251a-1. ), The shape of the exposed portion 251a of the semiconductor core 251 having a larger diameter than the semiconductor layer 252 and the same diameter as the semiconductor layer 252, and the stepped portion 251c of the semiconductor core 251. ) And the insulating layer 253 covering the end surface of the semiconductor layer 252 on the side of the stepped portion 251c and covering the small diameter portion 251a-1 side of the exposed portion 251a of the semiconductor core 251. In the manufacturing process of the rod-shaped structure light emitting element A2 of the twentieth embodiment, anisotropic dry etching is performed instead of the step of removing the mask and the region excluding the portion of the semiconductor layer covering the semiconductor core by lift-off, and the semiconductor layer It can form by etching to the area | region except the part which covers the semiconductor core 251 among these, and a mask and then a board | substrate.

The rod-shaped structure light emitting element E2 of the twenty-fourth embodiment has the same effect as the rod-shaped structure light emitting element A2 of the twentieth embodiment.

In addition, in the rod-shaped structure light emitting device E2, the semiconductor core 251 so as to cover the stepped portion 251c of the semiconductor core 251 and the end surface of the semiconductor layer 252 on the side of the stepped portion 251c. The insulating layer 253 is formed to cover the stepped portion 251c side of the exposed portion 251a of the insulating layer 253 between the outer circumferential surface of the exposed portion 251a of the semiconductor core 251 and the semiconductor layer 252. Insulated by the n-side electrode 254 and the semiconductor layer 252 when the n-side electrode 254 is connected to the exposed portion 251a of the semiconductor core 251. It can be restrained reliably.

In addition, since the diameter of the large diameter portion 251a-2 of the exposed portion 251a is larger than that of the covering portion 251b of the semiconductor core 251, the n-side electrode connected to the exposed portion 251a of the semiconductor core 251. The contact surface with 254 can be taken large to lower the contact resistance.

[25th Embodiment]

Fig. 59 is a sectional view of a rod-shaped structure light emitting device of a 25th embodiment of the present invention.

As shown in FIG. 59, the rod-shaped structure light emitting element F2 of the twenty-fifth embodiment does not cover the semiconductor core 261 made of the rod-shaped n-type GaN and the portion at one end side of the semiconductor core 261. A semiconductor layer 262 made of p-type GaN covering the coating portion 261b other than the exposed portion 261a of the semiconductor core 261 so as to be the exposed portion 261a, and formed so as to cover the semiconductor layer 262. And a conductive layer 263 made of a material having a lower electrical resistance than the semiconductor layer 262.

The exposed portion 261a of the semiconductor core 261 has a substantially circular cross section perpendicular to the longitudinal direction, and the covering portion 261b of the semiconductor core 261 has a substantially hexagonal cross section perpendicular to the longitudinal direction. The semiconductor core 261 has a step portion 261c formed between the outer circumferential surface of the exposed portion 261a and the outer circumferential surface of the coated portion 261b with the exposed portion 261a having a diameter smaller than that of the coated portion 261b. The end surface of the other end side of the semiconductor core 261 is covered with the semiconductor layer 262.

The conductive layer 263 is formed of ITO (tin-added indium oxide) having a thickness of 200 nm. The deposition of this ITO can be carried out by vapor deposition or sputtering. After the ITO film is formed, the heat treatment is performed at 500 ° C. to 600 ° C. to lower the contact resistance of the semiconductor layer 262 made of p-type GaN and the conductive layer 263 made of ITO. The conductive layer 263 is not limited to this, and a translucent laminated metal film of Ag / Ni or Au / Ni having a thickness of 5 nm may be used, for example. A vapor deposition method or a sputtering method can be used for film formation of this laminated metal film. Further, in order to lower the resistance of the conductive layer, a laminated metal film of Ag / Ni or Au / Ni may be laminated on the ITO film.

The rod-shaped structure light emitting element F2 is manufactured by the same method as the rod-shaped structure light emitting element A2 of the twentieth embodiment. After the rod-shaped structure light emitting device F2 forms the semiconductor layer 262 covering the semiconductor core 261 after the removal of the catalyst metal layer, and further forms the ITO film as a conductive layer to cover the semiconductor layer 262, Anisotropic dry etching removes the region of the ITO film except for the portion covering the semiconductor layer 262, and then, similarly to the twentieth embodiment, except for the portion of the semiconductor layer covering the semiconductor core 261 by lift-off. It can form by removing an area | region and a mask.

In addition, the rod-shaped structure light emitting element F2 of the 25th embodiment has the same effect as the rod-shaped structure light emitting element A2 of the twentieth embodiment.

According to the rod-shaped structure light emitting element F2 of the twenty-fifth embodiment, the cross-section orthogonal to the longitudinal direction of the covering portion 261a of the semiconductor core 261 has a hexagonal shape, thereby forming the rod-shaped structure light emitting element on the substrate. When mounting so that a longitudinal direction may become parallel with a plane, even if it is any outer peripheral surface of a semiconductor layer, a contact surface with a board | substrate will be easy to be obtained, and the heat radiation efficiency to a board | substrate will improve. Therefore, it can suppress that the element temperature at the time of light emission rises and light emission efficiency falls.

In addition, the shape of the cross section orthogonal to the longitudinal direction of the exposed portion 261a of the semiconductor core 261 differs from the shape of the cross section orthogonal to the longitudinal direction of the covering portion 261b of the semiconductor core 261. Since the stepped portion 261c is formed at the boundary between the outer circumferential surface of the exposed portion 261a of the exposed portion 261a and the outer circumferential surface of the covering portion 261b, the light extraction efficiency to the outside is improved.

In addition, by connecting the semiconductor layer 262 to the p-side electrode through the conductive layer 263 made of a material having a lower electrical resistance than the semiconductor layer 262, a wide current path can be achieved without concentrating current on the electrode connection portion. Can be formed so that the whole side surface of the semiconductor core 261 can be efficiently emitted, and the luminous efficiency is further improved.

[26th Embodiment]

Fig. 60 is a sectional view of the rod-shaped structure light emitting device of the 26th embodiment of the present invention.

As shown in FIG. 60, the rod-shaped structure light emitting element G2 of the 26th embodiment does not cover the semiconductor core 271 made of rod-shaped n-type GaN and the portion on one end side of the semiconductor core 271. A quantum well layer 272 made of p-type InGaN covering portions other than the exposed portion 271a of the semiconductor core 271 so as to be the exposed portion 271a, and a p-type covering the outer circumferential surface of the quantum well layer 272 A semiconductor layer 273 made of GaN and a conductive layer 274 made of a material having a lower electrical resistance than the semiconductor layer 273 are formed to cover the semiconductor layer 273.

The exposed portion 271a of the semiconductor core 271 has a substantially circular cross section perpendicular to the longitudinal direction, and the covering portion 271b of the semiconductor core 271 has a substantially hexagonal cross section perpendicular to the longitudinal direction. The semiconductor core 271 has a step portion 271c formed between the outer circumferential surface of the exposed portion 271a and the outer circumferential surface of the coated portion 271b with the exposed portion 271a having a diameter smaller than that of the coated portion 271b. The end surface of the other end side of the semiconductor core 271 is covered with the semiconductor layer 272.

The conductive layer 274 is formed of ITO (tin-added indium oxide) having a thickness of 200 nm. The deposition of this ITO can be carried out by vapor deposition or sputtering. After the ITO film is formed, the heat treatment is performed at 500 ° C. to 600 ° C. to lower the contact resistance of the semiconductor layer 272 made of p-type GaN and the conductive layer 274 made of ITO. The conductive layer 274 is not limited to this, and a translucent laminated metal film of Ag / Ni or Au / Ni having a thickness of 5 nm may be used, for example. A vapor deposition method or a sputtering method can be used for film formation of this laminated metal film. Further, in order to lower the resistance of the conductive layer, a laminated metal film of Ag / Ni or Au / Ni may be laminated on the ITO film.

The rod-shaped structure light emitting element G2 is manufactured by the same method as the rod-shaped structure light emitting element A2 of the twentieth embodiment. The rod-shaped structure light emitting device G2 forms a quantum well layer 272 and a semiconductor layer 273 covering the semiconductor core 271 after the removal of the catalyst metal layer, and also covers the semiconductor layer 273 in the ITO film. After forming an ITO film as a conductive layer, and removing the area | region except the part which covers the semiconductor layer 272 by anisotropic dry etching, similarly to 20th Embodiment, the semiconductor of a quantum well layer and a semiconductor layer is lifted off by lift-off. It can form by removing the mask and the area | region except the part which covers a core.

In addition, the rod-shaped structure light emitting element G2 of the 26th embodiment has the same effect as the rod-shaped structure light emitting element A2 of the twentieth embodiment.

According to the rod-shaped structure light emitting element G2 of the twenty-sixth embodiment, the cross-section orthogonal to the longitudinal direction of the covering portion 271a of the semiconductor core 271 has a hexagonal shape, thereby forming the rod-shaped structure light emitting element on the substrate. When mounting so that a longitudinal direction may become parallel with a plane, even if it is any outer peripheral surface of a semiconductor layer, a contact surface with a board | substrate will be easy to be obtained, and the heat radiation efficiency to a board | substrate will improve. Therefore, it can suppress that the element temperature at the time of light emission rises and light emission efficiency falls.

The shape of the cross section orthogonal to the longitudinal direction of the exposed portion 271a of the semiconductor core 271 differs from the shape of the cross section orthogonal to the longitudinal direction of the covering portion 271b of the semiconductor core 271. Since the stepped portion 271c is formed at the boundary between the outer circumferential surface of the exposed portion 271a of 271 and the outer circumferential surface of the covering portion 271b, the light extraction efficiency to the outside is improved.

In addition, by connecting the semiconductor layer 273 to the p-side electrode through the conductive layer 274 made of a material having a lower electrical resistance than the semiconductor layer 273, a wide current path can be achieved without concentration of current in the electrode connection portion. Can be formed so that the whole side surface of the semiconductor core 271 can be efficiently emitted, and the luminous efficiency is further improved.

In addition, the quantum well layer 272 is formed between the outer circumferential surface of the covering portion 271b of the semiconductor core 271 and the semiconductor layer 273 to improve the luminous efficiency by the quantum confinement effect of the quantum well layer 272. Can be.

The quantum well layer may be a multi-quantum well structure in which a GaN barrier layer and an InGaN quantum well layer are alternately stacked.

[27th Embodiment]

Fig. 61 is a sectional view of the rod-shaped structure light emitting device of the 27th embodiment of the present invention. The rod-shaped structure light emitting element of the twenty-seventh embodiment has the same structure as the rod-shaped structure light emitting element of the 26th embodiment except for the cap layer.

As shown in FIG. 61, the rod-shaped structure light emitting element H2 of the twenty-seventh embodiment includes a semiconductor core 281 made of rod-shaped n-type GaN having a substantially hexagonal cross section, and one of the semiconductor cores 281. An exposed portion 281a of the semiconductor core 281 so as to be an exposed portion 281a without covering a cap layer 282 covering the end surface of the cap layer 282 and a portion opposite to the portion of the semiconductor core 281 covered with the cap layer 282. A quantum well layer 283 made of p-type InGaN covering the outer circumferential surface of the coating portion 281b other than the?), A semiconductor layer 284 made of p-type GaN covering the outer circumferential surface of the quantum well layer 283, and the semiconductor The conductive layer 285 which covers the outer peripheral surface of the layer 284 is provided.

The semiconductor core 281 forms the stepped portion 281c between the outer circumferential surface of the exposed portion 281a and the outer circumferential surface of the coated portion 281b with the exposed portion 281a having a diameter smaller than that of the coated portion 281b. The outer circumferential surface of the semiconductor core 281 and the outer circumferential surface of the cap layer 282 are covered with a continuous quantum well layer 283 and a semiconductor layer 284.

The conductive layer 285 is formed of ITO (tin-added indium oxide) having a thickness of 200 nm. The deposition of this ITO can be carried out by vapor deposition or sputtering. After the ITO film is formed, the heat treatment is performed at 500 ° C. to 600 ° C. to lower the contact resistance of the semiconductor layer 284 made of p-type GaN and the conductive layer 285 made of ITO. The conductive layer 285 is not limited to this, and a translucent laminated metal film of Ag / Ni or Au / Ni having a thickness of 5 nm may be used, for example. A vapor deposition method or a sputtering method can be used for film formation of this laminated metal film. Further, in order to lower the resistance of the conductive layer, a laminated metal film of Ag / Ni or Au / Ni may be laminated on the ITO film.

FIG. 62: is a cross-sectional schematic diagram of the principal part of the said rod-shaped structure light emitting element H2, and as shown in FIG. 62, in the rod-shaped structure light emitting element H2 of 27th Embodiment, it is more electric than the semiconductor layer 284. FIG. The cap layer 282 made of a material having a high resistance covers one end surface of the semiconductor core 281 so that the p-side electrode 286 and the semiconductor core 281 connected to the cap layer 282 side of the semiconductor core 281 are covered. While the current does not flow through the cap layer 282, the outer peripheral surface side of the p-side electrode 286 and the semiconductor core 281 through the conductive layer 285 and the semiconductor layer 284 having lower resistance than the cap layer 282. Allow current to flow between them. This suppresses the concentration of current to the end surface of the side where the cap layer 282 of the semiconductor core 281 is provided, so that light emission is not concentrated on the end surface of the semiconductor core 281 and from the side surface of the semiconductor core 281. The extraction efficiency of light is improved.

The rod-shaped structure light emitting element H2 of the twenty-seventh embodiment has the same effect as the rod-shaped structure light emitting element of the twenty-sixth embodiment.

In addition, the rod-shaped structure light emitting device connects an n-side electrode (not shown) to the exposed portion 281a of the semiconductor core 281 and the p-side electrode 286 on the side where the cap layer 282 of the semiconductor core 281 is provided. ), The end surface of one side of the semiconductor core 281 is not exposed by the cap layer 282, so that the semiconductor core 281 and the p-side electrode are formed through the semiconductor layer 284 and the conductive layer 285 at the end thereof. Electrical connection of 286 can be facilitated. Thereby, the area which the p-side electrode 286 blocks among the whole side surfaces of the semiconductor core 281 covered with the semiconductor layer 284 and the conductive layer 285 can be minimized, and light extraction efficiency can be improved. . Further, the concentration of current to the end surface of the side where the cap layer 282 of the semiconductor core 281 is provided is suppressed, so that light emission is not concentrated on the end surface of the semiconductor core and the light extraction efficiency from the side surface of the semiconductor core 281 is improved. do.

In addition, only the conductive layer 285 and the p-side electrode 286 may be electrically connected to the cap layer 282 at the end portion of the semiconductor core 281 on the cap layer 282 side.

[28th Embodiment]

FIG. 63: shows the perspective view of the light emitting device provided with the rod-shaped structure light emitting element of 28th Embodiment of this invention.

As shown in FIG. 63, the light emitting device of the twenty-eighth embodiment includes an insulating substrate 290 having metal electrodes 298 and 299 formed on a mounting surface thereof, and an insulating substrate 290 having a longitudinal direction on the insulating substrate 290. The rod-shaped structure light emitting element 12 mounted so as to be parallel to the mounting surface thereof is provided.

The rod-shaped structure light emitting element I2 is a semiconductor core 291 made of a rod-shaped n-type GaN and a semiconductor core 291 so as to be an exposed portion 291a without covering a portion of one end side of the semiconductor core 291. The semiconductor layer 292 which consists of p-type GaN which covers the cover part 291b other than the exposed part 291a of this is provided.

The exposed portion 291a of the semiconductor core 291 has a substantially circular cross section perpendicular to the longitudinal direction, and the covering portion 291b of the semiconductor core 291 has a substantially hexagonal cross section perpendicular to the longitudinal direction. A stepped portion 291c is formed between the outer circumferential surface of the exposed portion 291a and the outer circumferential surface of the coated portion 291b with the exposed portion 291a of the semiconductor core 291 having a diameter smaller than that of the coated portion 291b.

As shown in FIG. 63, the exposed portion 291a of one end side of the rod-shaped structure light emitting element I2 is connected to the metal electrode 298, and the semiconductor layer on the other end side of the rod-shaped structure light emitting element I2. 292 is connected to the metal electrode 299.

Here, the rod-shaped light emitting element I2 is formed by evaporation of droplets of the gap between the substrate surface and the gap between the rod-shaped light emitting element during evaporation of the aqueous IPA solution in the arrangement method of the rod-shaped light emitting element of the 38th embodiment described later. The center portion is bent and contacted on the insulating substrate 290 by the stiction generated when it is reduced.

According to the light emitting device of the twenty-eighth embodiment, the rod-shaped structure light emitting element I2 mounted on the insulating substrate 290 so that the longitudinal direction thereof is parallel to the mounting surface is formed by the outer peripheral surface of the semiconductor layer 292 and the insulating substrate 290. Since the mounting surface is in contact with each other, heat generated in the rod-shaped structure light emitting device I2 can be efficiently radiated from the semiconductor layer 292 to the insulating substrate 290. Therefore, a light emitting device having high luminous efficiency and good heat dissipation can be realized. Moreover, also in the rod-shaped structure light emitting device in which the conductive layer is formed to cover the semiconductor layer, the effect is similarly obtained when the outer circumferential surface of the conductive layer and the mounting surface of the insulating substrate are in contact with each other.

In addition, in the light emitting device, since the rod-shaped structure light emitting device I2 is disposed on the insulating substrate 290 to the side, the thickness including the insulating substrate 290 can be reduced. In the above light emitting device, for example, a micro rod size of 1 μm in diameter and 10 μm in length or a fine rod-shaped structure light emitting element I2 having a nano order size of at least one of diameters or lengths of less than 1 μm is used. The amount of semiconductor can be reduced, and a backlight, an illumination device, a display device, and the like, which can be made thinner and lighter, can be realized using this light emitting device.

Further, in the twenty-eighth embodiment, any of the rod-shaped structure light emitting elements of the twentieth to twenty-eighth embodiments may be used for the rod-shaped structure light emitting element.

[29th Embodiment]

64 is a side view of a light emitting device including a rod-shaped structure light emitting element according to a twenty-ninth embodiment of the present invention.

As shown in FIG. 64, the light emitting device of the twenty-ninth embodiment is a rod-shaped package in which the longitudinal direction is parallel to the mounting surface of the insulating substrate 600 on the insulating substrate 600 and the insulating substrate 600. The structure light emitting element J2 is provided.

The rod-shaped structure light emitting element J2 includes a semiconductor core 601 made of rod-shaped n-type GaN, a cap layer 602 (shown in FIG. 65) covering one end surface of the semiconductor core 251, and the cap layer. Covering the outer circumferential surface of the covering portion 601b other than the exposed portion 601a of the semiconductor core 601 so as to be the exposed portion 601a without covering the portion opposite to the portion of the semiconductor core 601 covered with 602. A quantum well layer 603 made of p-type InGaN, a semiconductor layer 604 made of p-type GaN covering the outer circumferential surface of the quantum well layer 603, and a conductive layer 605 covering the outer circumferential surface of the semiconductor layer 604. ).

The exposed portion 601a of the semiconductor core 601 has a substantially circular cross section perpendicular to the longitudinal direction, and the covering portion 601b of the semiconductor core 601 has a substantially hexagonal cross section perpendicular to the longitudinal direction. The stepped portion 601c is formed between the outer circumferential surface of the exposed portion 601a and the outer circumferential surface of the coated portion 601b by making the exposed portion 601a of the semiconductor core 601 smaller than the coated portion 601b.

A metal layer 606 is formed on the conductive layer 605 as an example of the second conductive layer on the insulating substrate 600 side. The metal layer 606 covers approximately half of the lower side of the outer circumferential surface of the conductive layer 605. The conductive layer 605 is formed of ITO. The conductive layer is not limited to this, and a translucent laminated metal film of Ag / Ni or Au / Ni having a thickness of 5 nm may be used, for example. A vapor deposition method or a sputtering method can be used for film formation of this laminated metal film. Further, in order to lower the resistance of the conductive layer, a laminated metal film of Ag / Ni or Au / Ni may be laminated on the ITO film. The metal layer 606 is not limited to Al, and Cu, W, Ag, Au, or the like may be used.

As shown in FIG. 65, the light emitting device of the twenty-ninth embodiment includes an insulating substrate 600 having metal electrodes 607 and 608 formed on a mounting surface thereof, and an insulating substrate 600 having a longitudinal direction on the insulating substrate 600. The rod-shaped structure light emitting element J2 is mounted so as to be parallel to the mounting surface of the device.

The exposed portion 601a on one end side of the rod-shaped structure light emitting element J2 is connected to the metal electrode 607 by an adhesive portion 109A such as a conductive adhesive, and the other portion of the rod-shaped structure light emitting element J2 is connected. The metal layer 606 on the short side is connected to the metal electrode 608 by an adhesive portion 609B such as a conductive adhesive.

Here, the rod-shaped light emitting device J2 is formed by evaporation of droplets of the gap between the substrate surface and the gap between the rod-shaped light emitting device during evaporation of the IPA aqueous solution in the arrangement method of the rod-shaped light emitting device according to the twelfth embodiment. The center portion is bent and contacted on the insulating substrate 600 by the stiction generated when it is reduced.

According to the light emitting device of the twenty-ninth embodiment, the second conductive layer is formed of a material having a lower electrical resistance than the semiconductor layer 604 on the conductive layer 605 of the rod-shaped structure light emitting element J2 and on the insulating substrate 600 side. By forming the metal layer 606 as an example, the conductive layer 605 covering the outer circumferential surface of the semiconductor core 601 also on the side opposite to the insulating substrate 600 of the rod-shaped structure light emitting device J2 without the metal layer 606. As a result, the resistance can be reduced by the metal layer 606 without sacrificing the ease of current flow through the high-resistance semiconductor layer 604. In addition, since the material having low transmittance is not used for the conductive layer 605 covering the outer circumferential surface of the semiconductor core 601, a material having low transmittance is not used, but a material having low resistance cannot be used, but the metal layer 606 has a lower resistance than transmittance. Preferred conductive materials can be used. In addition, in the rod-shaped structure light emitting device J2 mounted on the insulating substrate 600 so that the longitudinal direction thereof is parallel to the mounting surface, since the metal layer 606 contacts the mounting surface of the insulating substrate 600, the rod-shaped structure light emitting device ( Heat generated by J2) may be efficiently radiated to the insulating substrate 600 through the metal layer 606.

[30th Embodiment]

66 is a perspective view of a light emitting device of a thirtieth embodiment of the present invention. In this thirtieth embodiment, a rod-shaped structure light emitting element having the same structure as that of the rod-shaped structure light emitting element B2 of the twenty-first embodiment is used. In addition, any of the rod-shaped light emitting elements of the twentieth, twenty-second to twenty-ninth embodiments may be used for the rod-shaped light emitting elements.

As shown in FIG. 66, the light emitting device of the thirtieth embodiment has an insulating substrate 700 having metal electrodes 701 and 702 formed on a mounting surface thereof, and an insulating substrate 700 having a longitudinal direction on the insulating substrate 700. The rod-shaped structure light emitting element K2 is mounted so as to be parallel to the mounting surface. In the insulating substrate 700, a third metal electrode 703 as an example of the metal portion is formed between the metal electrodes 701 and 702 on the insulating substrate 700 and under the rod-shaped structure light emitting element K2. 66 shows only a part of the metal electrodes 701, 702, and 703.

The rod-shaped structure light emitting element K2 has a semiconductor core 611 made of a rod-shaped n-type GaN having a substantially hexagonal cross section, and an exposed portion 611a without covering a portion opposite to the portion of the semiconductor core 611. The semiconductor layer 612 which consists of p-type GaN which covers the outer peripheral surface of the coating part 611b other than the exposed part 611a of the semiconductor core 611 so that it may be set to this is provided. The semiconductor core 611 has a stepped portion 611c between the outer circumferential surface of the exposed portion 611a and the outer circumferential surface of the coated portion 611b with the exposed portion 611a having a smaller diameter than the covered portion 611b. The end surface of the other end side of the semiconductor core 611 is covered with the semiconductor layer 612.

According to the light emitting device of the thirtieth embodiment, both ends are connected to the metal electrodes 701 and 702 by forming the metal electrode 703 between the electrodes 701 and 702 on the insulating substrate 700 and also under the rod-shaped structure light emitting element K2. Since the center side of the rod-shaped light emitting element K2 is supported by being brought into contact with the surface of the metal electrode 703, the rod-shaped structured light emitting element K2 of both supports is supported by the metal electrode 703 without bending, Heat generated in the rod-shaped structure light emitting device K2 can be efficiently radiated from the semiconductor layer 612 to the insulating substrate 700 through the metal electrode 703.

As shown in FIG. 67, each of the metal electrode 701 and the metal electrode 702 is formed from opposing positions of the bases 701a and 702a and the bases 701a and 702a which are substantially parallel to each other at predetermined intervals. It has a plurality of electrode portions 701b and 702b extending between the bases 701a and 702a. One rod-shaped structure light emitting element K2 is arranged in the electrode portion 701b of the metal electrode 701 and the electrode portion 702b of the metal electrode 702 facing it. A butterfly-shaped third metal electrode 703 having a narrow central portion is formed between the electrode portion 701b of the metal electrode 701 and the electrode portion 702b of the metal electrode 702 opposite to the insulating substrate 700. To form.

The third metal electrodes 703 that are adjacent to each other are electrically separated from each other, and as shown in FIG. 67, even when the directions of the rod-shaped structure light emitting elements K2 that are adjacent to each other are reversed, the metal electrodes are passed through the metal electrodes 703. The short circuit of 701 and the metal electrode 702 can be prevented.

In the twentieth to thirtieth embodiments, a semiconductor based on GaN is used for the semiconductor core, the cap layer, and the semiconductor layer, but a semiconductor based on GaAs, AlGaAs, GaAsP, InGaN, AlGaN, Ga P, ZnSe, AlGaInP You may apply this invention to the light emitting element which used. In addition, although the semiconductor core is n-type and the semiconductor layer is p-type, you may apply this invention to the rod-shaped structure light emitting element whose electroconductive type is the opposite. Moreover, although the rod-shaped structure light emitting element which has a round or hexagonal rod-shaped semiconductor core was demonstrated, it is not limited to this, The cross-section may be an elliptic rod shape, and the cross section is a rod-shaped semiconductor of other polygonal shapes, such as a triangle. You may apply this invention to the rod-shaped structure light emitting element which has a core.

In addition, in the 20th to 30th embodiments, the rod-shaped structure light emitting device has a diameter of 1 µm and a micro order size of 10 µm to 30 µm in length, but at least the diameter or length of the nano order size of less than 1 µm. An element may be sufficient. The diameter of the semiconductor core of the rod-shaped structure light emitting device is preferably 500 nm or more and 100 μm or less, and the variation in the diameter of the semiconductor core can be suppressed as compared to the rod-shaped structure light emitting device of several tens of nm to several hundred nm. The deviation of the luminescence properties can be reduced and the yield can be improved.

In the twentieth to thirtieth embodiments, the semiconductor core and the cap layer are grown using a MOCVD apparatus, but the semiconductor core and the cap layer may be formed using another crystal growth apparatus such as a molecular beam epitaxial (MBE) apparatus. . In addition, although the semiconductor core is crystal-grown on the substrate using a mask having growth holes, the semiconductor core may be crystal-grown from the metal species by disposing a metal species on the substrate.

[31st Embodiment]

68A to 68E are process charts showing the manufacturing method of the rod-shaped structure light emitting device according to the thirty-first embodiment of the present invention. In this embodiment, n-type GaN doped with Si and p-type GaN doped with Mg are used, but impurities doped in GaN are not limited thereto.

First, as shown in Fig. 68A, a mask 812 having a growth hole 812a is formed on a substrate 811 made of n-type GaN. The mask 812 is made of a material that inhibits the formation of the semiconductor layer 814, and covers the part of the outer circumferential surface of the semiconductor core 813, which is a portion to be exposed, and then removes the mask 812 after the semiconductor layer forming process. A part of the outer circumferential surface of 813 can be easily exposed. Herein, a material capable of selectively etching the semiconductor core and the semiconductor layer, such as silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ), is used as a material that inhibits the formation of the semiconductor layer 814. The substance to inhibit is not limited to this, What is necessary is just to select suitably according to the composition of a semiconductor layer. Formation of a growth hole can use the well-known lithography method and the dry etching method used for a normal semiconductor process. At this time, the diameter of the growing semiconductor core depends on the size of the growth holes of the mask.

Next, as shown in FIG. 68B, a MOCVD (Metal Organic Chemical Vapor Deposition) device is placed on the substrate 811 exposed by the growth holes 812a of the mask 812 in the semiconductor core forming step. The n-type GaN is crystal-grown to form a rod-shaped semiconductor core 813. The growth temperature is set at about 950 ° C., trimethylgallium (TMG) and ammonia (NH ₃ ) are used as growth gases, silane (SiH ₄ ) is used for n-type impurity supply, and hydrogen (H ₂ ) is used as a carrier gas. By supplying, it is possible to grow an n-type GaN semiconductor core with Si as an impurity. Here, the n-type GaN becomes hexagonal crystal growth, and a hexagonal pillar-shaped semiconductor core is obtained by growing with the c-axis direction perpendicular to the surface of the substrate 811.

Subsequently, as shown in FIG. 68C, in the semiconductor layer forming step, a semiconductor layer 814 is formed in which the entire surface of the substrate 811 is made of p-type GaN so as to cover the rod-shaped semiconductor core 813. The formation temperature is set to about 960 ° C, and magnesium (Mg) is obtained by using trimethylgallium (TMG) and ammonia (NH ₃ ) as growth gases, and biscyclopentadienyl magnesium (Cp ₂ Mg) for supplying p-type impurities. It is possible to grow p-type GaN as an impurity.

Subsequently, as shown in FIG. 68D, in the exposure step, the mask 812 is removed by removing the region except for the portion of the semiconductor layer 814 that covers the semiconductor core 813 by the lift-off to remove the rod-shaped semiconductor core 813. An exposed portion 813a is formed by exposing the outer peripheral surface of the substrate side to the substrate 811 side. In this state, the end surface on the side opposite to the substrate 811 of the semiconductor core 813 is covered by the semiconductor layer 814a. When the mask is made of silicon oxide (SiO ₂ ), by using a solution containing hydrofluoric acid (HF), the mask can be easily etched without affecting the semiconductor core and the portion of the semiconductor layer covering the semiconductor core. In addition, the area | region except the part of the semiconductor layer which covers a semiconductor core can be removed by lift-off. Although the lift-off was used in the exposure process of this embodiment, you may expose a part of semiconductor core by etching. In the case of dry etching, by using CF ₄ or XeF ₂ , the mask can be easily etched without affecting the semiconductor core and the portion of the semiconductor layer covering the semiconductor core, except for the portion of the semiconductor layer covering the semiconductor core with the mask. The area can be removed.

Subsequently, in the separation step, the semiconductor core is placed on the substrate 811 by immersing the substrate in an isopropyl alcohol (IPA) aqueous solution and vibrating the substrate 811 along the substrate plane using ultrasonic waves (for example, several tens of microseconds). Stress is applied to the semiconductor core 813 covered with the semiconductor layer 814a so that the source close to the substrate 811 side of the 813 is bent, and as shown in FIG. 68E, the semiconductor covered with the semiconductor layer 814a. Core 813 is separated from substrate 811.

In this way, a fine rod-shaped structure light emitting element 810 separated from the substrate 811 can be manufactured. In the thirty-first embodiment, the rod-shaped structure light emitting element 810 has a diameter of 1 μm and a length of 10 μm.

The rod-shaped structure light emitting element 810 is connected from the p-type semiconductor layer 814a by connecting one electrode to the exposed portion 813a of the semiconductor core 813 and the other electrode to the semiconductor layer 814a. By flowing a current through the n-type semiconductor core 813, electrons and holes are recombined at the pn junction of the outer circumferential surface of the n-type semiconductor core 813 and the inner circumferential surface of the p-type semiconductor layer 814a to emit light. Since light is emitted from the entire circumference of the semiconductor core 813 covered with the semiconductor layer 814a, the light emitting area is widened, so that high light emitting efficiency is obtained.

According to the manufacturing method of the rod-shaped structure light emitting element of the above-mentioned structure, the fine rod-shaped structure light emitting element 810 which has high degree of freedom of mounting to an apparatus can be manufactured. In addition, since the rod-shaped structure light emitting device is used as a microstructure separated from the substrate, the amount of semiconductor used can be reduced, and the thickness and weight of the device using the light emitting device can be reduced and the semiconductor layer 814a can be used. Since light is emitted from the entire circumference of the covered semiconductor core 813, the light emitting area is widened, and thus a backlight, a lighting device, a display device, and the like having high luminous efficiency can be realized.

In the exposure step of exposing a part of the outer circumferential surface of the semiconductor core 813, the outer circumferential surface of the semiconductor core 813 on the substrate 811 side is exposed, and the semiconductor core 813 is formed in the semiconductor layer forming step. By covering the end surface on the side opposite to the substrate 811 with the semiconductor layer 814, the exposed portion 813a on the substrate 811 side of the semiconductor core 813 is connected to the n-side electrode and the The p-side electrode can be connected to the portion of the semiconductor layer 814a that covers the side opposite to the substrate 811 of the semiconductor core 813 by covering the end surface on the side opposite to the substrate 811. Can be. As a result, the electrodes can be easily connected to both ends of the fine rod-shaped light emitting device.

In addition, in the separation step, a source close to the substrate 811 side of the semiconductor core 813 standing on the substrate 811 is bent by vibrating the substrate 811 along the substrate 811 plane using ultrasonic waves. Stress is applied to the semiconductor core 813 covered with the semiconductor layer 814a so that the semiconductor core 813 covered with the semiconductor layer 814a is separated from the substrate 811. Therefore, a plurality of fine rod-shaped structure light emitting elements provided on the substrate 811 can be easily separated by a simple method.

In the separation step, the semiconductor core 813 may be mechanically separated from the substrate 811 using a cutting tool. A source close to the substrate 811 side of the semiconductor core 813, which is installed on the substrate 811 by using a cutting tool, is bent, and stress is applied to the semiconductor core 813 covered with the semiconductor layer 814a. In operation, the semiconductor core 813 covered with the semiconductor layer 814a is separated from the substrate 811. In this case, a plurality of fine rod-shaped structure light emitting elements provided on the substrate 811 can be separated in a short time by a simple method.

In the exposure step, dry etching may be used, and part of the outer circumferential surface of the semiconductor core 813 made of a semiconductor containing GaN as a base material can be easily exposed. Since the semiconductor using GaN as a base material is difficult to wet-etch, when the semiconductor core 813 and the semiconductor layer 814a are made of a semiconductor containing GaN as the base material, the semiconductor wafer 813 may be subjected to dry etching before the separation process. Exposing part is particularly effective in realizing a fine rod-shaped light emitting device which is easy to mount. In addition, when the semiconductor core 813 covered with the semiconductor layer 814a is separated from the substrate 811 without an exposure step of exposing a part of the outer circumferential surface of the semiconductor core 813, a fine rod-shaped structure light emitting device is manufactured. After arranging the fine rod-shaped light emitting elements on the insulating substrate 811, a part of the outer circumferential surface of the semiconductor core 813 can be easily exposed for electrode connection using dry etching.

In the exposure step, the outer peripheral surface of the region covered with the semiconductor layer 814a of the semiconductor core 813 and the outer peripheral surface of the exposed region of the semiconductor core 813 are continuous so that the exposed region of the semiconductor core 813 is thinned. Therefore, it is easy to bend at the side of the board | substrate 811 of the exposed area | region of the semiconductor core 813 in the said separation process, and separation becomes easy.

In addition, in the rod-shaped light emitting device manufactured by the method of manufacturing the rod-shaped light emitting device, the semiconductor layer 814a crystal grows radially outward from the outer peripheral surface of the semiconductor core 813, and the growth distance in the radial direction is short. In addition, since the defect is avoided outwardly, the semiconductor core 813 can be covered by the semiconductor layer 814a having fewer crystal defects. Therefore, a rod-shaped structure light emitting device having good characteristics can be realized.

[32th Embodiment]

69A to 69E are process drawings showing a method for manufacturing a rod-shaped structure light emitting device according to a thirty-second embodiment of the present invention. The rod-shaped structure light emitting element of the thirty-second embodiment has the same structure as the rod-shaped structure light emitting element of the thirty-first embodiment except for the quantum well layer.

First, as shown in FIG. 69A, a mask 822 having growth holes 822a is formed on a substrate 821 made of n-type GaN. As the mask, a material capable of selectively etching the semiconductor core and the semiconductor layer, such as silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ), may be used. Formation of a growth hole can use the well-known lithography method and the dry etching method used for a normal semiconductor process. At this time, the diameter of the growing semiconductor core depends on the size of the growth holes of the mask.

69B, n-type GaN is crystal-grown on the board | substrate 821 exposed by the growth hole 822a of the mask 822 in a semiconductor core formation process using MOCVD apparatus, and rod-shaped semiconductor is carried out. The core 23 is formed. The growth temperature is set at about 950 ° C., trimethylgallium (TMG) and ammonia (NH ₃ ) are used as growth gases, silane (SiH ₄ ) is used for n-type impurity supply, and hydrogen (H ₂ ) is used as a carrier gas. By supplying, it is possible to grow an n-type GaN semiconductor core with Si as an impurity. Here, n-type GaN becomes hexagonal crystal growth, and a hexagonal rod-shaped semiconductor core is obtained by growing in a c-axis direction perpendicular to the surface of the substrate 821.

Next, as shown in FIG. 69C, in the quantum well layer and the semiconductor layer forming step, a quantum well layer 824 made of p-type InGaN is formed on the entire surface of the substrate 821 so as to cover the rod-shaped semiconductor core 823. The semiconductor layer 825 is formed over the entire surface of the substrate 821. After growing the semiconductor core of n-type GaN as described above in the MOCVD apparatus, the set temperature was changed from 600 ° C. to 800 ° C. according to the emission wavelength, nitrogen (N ₂ ) in the carrier gas, TMG and NH in the growth gas. By supplying ₃ , trimethylindium (TMI), the InGaN quantum well layer 824 can be formed on the semiconductor core 21 of n-type GaN. Then, also the temperature of a 960 ℃, and as described above, a semiconductor layer 825 made of p-type GaN by using Cp ₂ Mg in for using TMG and NH _3, and the p-type impurity provided as a growth gas set Can be formed. The quantum well layer may also include a p-type AlGaN layer as an electron block layer between the InGaN layer and the p-type GaN layer. In addition, a multi-quantum well structure may be formed by alternately stacking a GaN barrier layer and an InGaN quantum well layer.

Subsequently, as shown in FIG. 69D, in the exposure step, the rod-shaped region and mask 822 are removed by lifting off the portions except for the portions covering the semiconductor core 823 of the quantum well layer 824 and the semiconductor layer 825. An exposed portion 823a is formed by exposing the outer peripheral surface of the substrate side to the substrate 821 side of the upper semiconductor core 823. In this state, the end surface on the side opposite to the substrate 821 of the semiconductor core 823 is covered by the quantum well layer 824a and the semiconductor layer 825a. When the mask is made of silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ), using a solution containing hydrofluoric acid (HF) does not easily affect the semiconductor core and the portion of the semiconductor layer covering the semiconductor core. The mask can be etched without removal, and the region except for the portion of the semiconductor layer covering the semiconductor core with the mask can be removed by lift off. Although the lift-off was used in the exposure process of this embodiment, you may expose a part of semiconductor core by etching. In the case of dry etching, by using CF ₄ or XeF ₂ , the mask can be easily etched without affecting the semiconductor core and the portion of the semiconductor layer covering the semiconductor core, except for the portion of the semiconductor layer covering the semiconductor core with the mask. The area can be removed.

Subsequently, in the separation step, the semiconductor core is placed on the substrate 821 by immersing the substrate in an isopropyl alcohol (IPA) aqueous solution, and vibrating the substrate 821 along the substrate plane using ultrasonic waves (for example, several tens of microseconds). Stress is applied to the semiconductor core 823 covered with the quantum well layer 824 and the semiconductor layer 825a so that the source close to the substrate 821 side of the 823 is bent, as shown in FIG. 69E. The semiconductor core 823 covered with the layer 824 and the semiconductor layer 825a is separated from the substrate 821.

In this way, the fine rod-shaped structure light emitting element 820 separated from the substrate 821 can be manufactured. In the thirty-second embodiment, the rod-shaped structure light emitting element 820 has a diameter of 1 μm and a length of 10 μm.

The rod-shaped structure light emitting device 820 is connected to the n-side electrode to the exposed portion 823a of the semiconductor core 823, and the p-side electrode is connected to the semiconductor layer 825a to form n from the p-type semiconductor layer 825a. By flowing a current through the semiconductor core 823 of the type, recombination of electrons and holes occurs in the quantum well layer 824a to emit light. Since light is emitted from the entire circumference of the semiconductor core 823 covered with the semiconductor layer 825a, the light emitting area is widened, so that high light emitting efficiency is obtained.

According to the manufacturing method of the rod-shaped structure light emitting element of the above-mentioned structure, the fine rod-shaped structure light emitting element 820 which has high degree of freedom of mounting to an apparatus can be manufactured. In addition, the rod-shaped structure light emitting device can reduce the amount of semiconductor used, can reduce the thickness and weight of the device using the light emitting device, and emit light from the entire circumference of the semiconductor core 823 to emit light. As a result, the light emitting efficiency and the power-saving backlight, lighting device and display device can be realized.

The manufacturing method of the rod-shaped structure light emitting element of the thirty-second embodiment has the same effect as the manufacturing method of the rod-shaped structure light emitting element of the thirty-first embodiment.

In addition, the quantum well layer 824a has a quantum confinement effect of the quantum well layer 824a by emitting light by recombination of electrons and holes in the quantum well layer 824a formed between the n-type semiconductor core 823 and the p-type semiconductor layer 825a. As a result, the luminous efficiency can be made higher than in the thirty first embodiment.

[33rd Embodiment]

70A to 70D are process charts showing the manufacturing method of the rod-shaped structure light emitting device according to the 33rd embodiment of the present invention. The rod-shaped structure light emitting element of the thirty-third embodiment has the same structure as the rod-shaped structure light emitting element of the thirty-first embodiment except for the exposed portion of the semiconductor core.

First, as shown in FIG. 70A, in the semiconductor core forming step, n-type GaN is crystal grown on the n-type GaN substrate 831 to form a rod-shaped semiconductor core 833. The semiconductor core 833 is formed in the same manner as in the thirty first embodiment, and the mask is deleted.

Next, as shown in FIG. 70B, in the semiconductor layer forming step, a semiconductor layer 834 including p-type GaN is formed on the entire surface of the substrate 831 so as to cover the rod-shaped semiconductor core 833.

Next, as shown to FIG. 70C, the board | substrate 831 side of the rod-shaped semiconductor core 833 is removed by removing the area | region except the part of the semiconductor layer 834 which covers the semiconductor core 833 by dry etching in an exposure process. The outer peripheral surface is exposed to form an exposed portion 833a. In this case, by using SiCl ₄ for dry etching RIE (Reactive Ion Etching), GaN can be easily etched with anisotropy. In this state, the end surface on the side opposite to the substrate 831 of the semiconductor core 833 is exposed by dry etching.

Here, the outer circumferential surface of the semiconductor layer 834a and the outer circumferential surface of the exposed portion 833a of the semiconductor core 833 are continuous without a step. Thereby, when mounting the fine rod-shaped structure light emitting element after separation so that the axial direction may become parallel to a board | substrate plane on the insulating substrate in which the electrode was formed, the outer peripheral surface of the semiconductor layer 834a and the exposed part of the semiconductor core 833 may be carried out. Since there is no step between the outer circumferential surfaces of the 833a, the exposed portion 833a of the semiconductor core 833 and the electrode can be reliably and easily connected.

Subsequently, in the separation step, the semiconductor core is placed on the substrate 831 by immersing the substrate in an isopropyl alcohol (IPA) aqueous solution and vibrating the substrate 831 along the substrate plane using ultrasonic waves (for example, several tens of microseconds). A stress acts on the semiconductor core 833 covered with the semiconductor layer 834a so that the source close to the substrate 831 side of the 833 is bent, and as shown in FIG. 70D, the semiconductor covered with the semiconductor layer 834a. Core 833 is separated from substrate 831.

In this way, the fine rod-shaped structure light emitting device 830 separated from the substrate 831 can be manufactured. In the thirty-third embodiment, the rod-shaped structure light emitting element 830 has a diameter of 1 μm and a length of 10 μm.

The rod-shaped structure light emitting device 830 connects the n-side electrode to the exposed portion 833a of the semiconductor core 833, and the p-side electrode to the semiconductor layer 834a, thereby connecting the n-type electrode from the p-type semiconductor layer 834a. By flowing a current through the semiconductor core 833 of the type, recombination of electrons and holes occurs at the pn junction between the outer peripheral surface of the n-type semiconductor core 833 and the inner peripheral surface of the p-type semiconductor layer 834a, thereby emitting light. Since light is emitted from the entire circumference of the semiconductor core 833 covered with the semiconductor layer 834a, the light emitting area is widened, so that high light emitting efficiency is obtained.

According to the manufacturing method of the rod-shaped structure light emitting element of the above structure, the fine rod-shaped structure light emitting element 830 which has high degree of freedom of mounting to an apparatus can be manufactured. In addition, the rod-shaped structured light emitting device can reduce the amount of semiconductor used, and it is possible to reduce the thickness and weight of the device using the light emitting device and to emit light from the entire circumference of the semiconductor core covered with the semiconductor layer. Since the light emitting area is wider, a high luminous efficiency and a power saving backlight, lighting device, display device, and the like can be realized.

The manufacturing method of the rod-shaped structure light emitting element of the thirty-third embodiment has the same effect as the manufacturing method of the rod-shaped structure light emitting element of the thirty-first embodiment.

As shown in FIG. 70C, the region excluding the portion of the semiconductor layer 834 that covers the surface of the semiconductor core 833 after the semiconductor layer forming process and before the separation process, and the n-type GaN substrate 831 corresponding to the region. A part of the outer circumferential surface of the semiconductor core 833 is exposed by etching to remove a part of the thickness direction of the upper region of the upper region of the upper region of the semiconductor layer 833a so that the step between the exposed portion 833a of the outer circumferential surface of the semiconductor layer 834a and the outer peripheral surface of the semiconductor core 833 Can be avoided. This ensures that the exposed portion 833a and the electrode of the semiconductor core 833 are reliably mounted when the minute rod structure light emitting element after separation is mounted on the insulating substrate on which the electrode is formed so that the axial direction becomes parallel to the substrate plane. In addition, it is possible to easily connect.

[34th Embodiment]

71A to 71D are process charts showing the manufacturing method of the rod-shaped structure light emitting device of the 34th embodiment of the present invention. The rod-shaped structure light emitting element of the thirty-fourth embodiment has the same structure as the rod-shaped structure light emitting element of the thirty-second embodiment except for the exposed portion of the semiconductor core.

First, as shown in FIG. 71A, in the semiconductor core forming step, n-type GaN is grown on the n-type GaN substrate 841 to form a rod-shaped semiconductor core 843. The semiconductor core 843 is formed in the same manner as in the thirty first embodiment, and the mask is removed.

As shown in FIG. 71B, in the quantum well layer and semiconductor layer forming step, a quantum well layer 844 made of p-type InGaN is formed on the entire surface of the substrate 841 so as to cover the rod-shaped semiconductor core 843. The semiconductor layer 845 is formed over the entire surface of the substrate 841. The quantum well layer may have a multi-quantum well structure in which a barrier layer and a quantum well layer are laminated.

Next, as shown in FIG. 71C, in the exposure step, the region except for the portions excluding the portions covering the quantum well layer 844 and the semiconductor core 843 of the semiconductor layer 845 by dry etching is removed to form a rod-shaped semiconductor core 843. The exposed portion 843a is formed by exposing the outer circumferential surface of the substrate 841 side to the substrate 841 side. In this case, by using SiCl ₄ for RIE of dry etching, etching can be easily performed with anisotropy in GaN. In this state, the end surface on the side opposite to the substrate 841 of the semiconductor core 843 is exposed by dry etching.

Here, the outer circumferential surface of the semiconductor layer 845a and the outer circumferential surface of the exposed portion 843a of the semiconductor core 843 are continuous without a step (exposed portion of the outer circumferential surface of the quantum well layer 844a and exposed portion of the semiconductor core 843). (843a) also has no step. As a result, when the fine rod-shaped structure light emitting element after separation is mounted on the insulating substrate on which the electrode is formed so that the axial direction is parallel to the substrate plane, the outer peripheral surface of the semiconductor layer 845a and the exposed portion of the semiconductor core 843 are separated. Since there is no step between the outer circumferential surfaces of 843a, the exposed portion 843a of the semiconductor core 843 and the electrode can be reliably and easily connected.

Subsequently, in the separation step, the semiconductor core is immersed on the substrate 841 by immersing the substrate in an isopropyl alcohol (IPA) aqueous solution and vibrating the substrate 841 along the substrate plane using ultrasonic waves (for example, several tens of microseconds). A stress acts on the semiconductor core 843 covered with the semiconductor layer 845a so that the source close to the substrate 841 side of the 843 is bent, and as shown in FIG. 71D, the semiconductor covered with the semiconductor layer 845a. Core 843 is separated from substrate 841.

In this way, the fine rod-shaped structure light emitting element 840 separated from the substrate 841 can be manufactured. In the thirty-fourth embodiment, the rod-shaped structure light emitting element 840 has a diameter of 1 μm and a length of 10 μm.

The rod-shaped structure light emitting device 840 connects the n-side electrode to the exposed portion 843a of the semiconductor core 843, and the p-side electrode to the semiconductor layer 845a to connect the n-type electrode to the p-type semiconductor layer 845a. By flowing an electric current through the semiconductor core 843 of the type, recombination of electrons and holes occurs in the quantum well layer 844a to emit light. Since light is emitted from the entire circumference of the semiconductor core 843 covered with the semiconductor layer 845a, the light emitting area is widened, so that high light emitting efficiency is obtained.

According to the manufacturing method of the rod-shaped structure light emitting element of the above structure, the fine rod-shaped structure light emitting element 840 with high degree of freedom of mounting to an apparatus can be manufactured. In addition, the rod-shaped structured light emitting device can reduce the amount of semiconductor used, and it is possible to reduce the thickness and weight of the device using the light emitting device and to emit light from the entire circumference of the semiconductor core covered with the semiconductor layer. Since the light emitting area is wider, a high luminous efficiency and a power saving backlight, lighting device, display device, and the like can be realized.

The manufacturing method of the rod-shaped structure light emitting element of the thirty-fourth embodiment has the same effect as the manufacturing method of the rod-shaped structure light emitting element of the thirty-first embodiment.

In addition, in the quantum well layer 844a formed between the n-type semiconductor core 843 and the p-type semiconductor layer 845a, recombination of electrons and holes occurs to emit light, thereby causing quantum confinement effects of the quantum well layer 844a. As a result, the luminous efficiency can be made higher than in the thirty-third embodiment.

As shown in FIG. 71C, a region excluding the portion of the quantum well layer 844 and the semiconductor layer 845 that covers the surface of the semiconductor core 843 after the semiconductor layer formation process and before the separation process, and the region corresponding thereto. A part of the outer circumferential surface of the semiconductor core 843 is exposed by etching to remove a part of the thickness direction of the upper region of the n-type GaN substrate 841, thereby exposing the outer circumferential surface of the semiconductor layer 844a and the outer circumferential surface of the semiconductor core 843. There may be no step between the portions 843a. This ensures that the exposed portion 843a and the electrode of the semiconductor core 843 are securely mounted when the fine rod-shaped structure light emitting element after separation is mounted on the insulating substrate on which the electrode is formed so that the axial direction is parallel to the substrate plane. In addition, it is possible to easily connect.

[35th Embodiment]

72-94 is process drawing which shows the manufacturing method of the rod-shaped structure light emitting element of 35th Embodiment of this invention. In the thirty-fifth embodiment, n-type GaN doped with Si and p-type GaN doped with Mg are used, but impurities doped in GaN are not limited thereto.

First, the surface of the board | substrate 911 shown in FIG. 72 is cleaned. As the substrate, a substrate capable of growing GaN such as Si, SiC, sapphire or the like can be used.

73, a growth mask layer (hereinafter referred to as a mask) 912 is formed on the substrate 911. As the mask, a material which can be selectively etched against a semiconductor core such as silicon oxide (SiO ₂ ) and the semiconductor layer can be used.

74, the hole 920a is formed by patterning in the resist 920 apply | coated on the board | substrate 911 using the well-known lithographic method used for a normal semiconductor process.

75, the growth hole 912a is formed in the mask 912 using the hole 920a of the patterned resist 920. Then, as shown in FIG. Formation of a growth hole can use the dry etching method.

Next, as shown in FIG. 76, the catalyst metal 913 for semiconductor core growth is formed into a film. As the catalyst metal, a material that promotes the growth of the semiconductor of the semiconductor core, such as Ni, Fe, or Au, can be used.

Next, as shown in FIG. 77, the area | region and the resist 920 of the catalyst metal 913 formed into the film | membrane other than the growth hole 912a (shown in FIG. 75) are removed. Although lift-off is used here, you may use the lithographic method and the etching.

At this time, the diameter of the growing semiconductor core depends on the size of the growth holes of the mask and the volume of the catalyst metal.

Next, as shown in FIG. 78, MOCVD (Metal Organic Chemical Vapor Deposition) organic metal on the board | substrate 911 in the growth hole 912a of the mask layer 912 which has a catalyst metal 913 in a semiconductor core formation process. Vapor phase growth) The n-type GaN is crystal grown using a device to form a rod-shaped semiconductor core 914. The growth temperature is set at about 950 ° C., trimethylgallium (TMG) and ammonia (NH ₃ ) are used as growth gases, silane (SiH ₄ ) is used for n-type impurity supply, and hydrogen (H ₂ ) is used as a carrier gas. By supplying, it is possible to grow an n-type GaN semiconductor core with Si as an impurity. Here, the n-type GaN is grown with the c-axis direction perpendicular to the surface of the substrate 911 to obtain a semiconductor core having most of a nonpolar plane or a semipolar plane.

Next, as shown in FIG. 79, the quantum well layer 915 which consists of p-type InGaN is formed in the whole surface of the board | substrate 911 so that the rod-shaped semiconductor core 914 may be covered in a quantum well layer and a semiconductor layer formation process. In addition, the semiconductor layer 916 is formed on the entire surface of the substrate 911. After growing the semiconductor core of n-type GaN as described above in the MOCVD apparatus, the set temperature was changed from 600 ° C. to 800 ° C. according to the emission wavelength, nitrogen (N ₂ ) in the carrier gas, TMG and NH in the growth gas. _The InGaN quantum well layer 915 can be formed on the semiconductor core 914 of n-type GaN by supplying ₃ , trimethyl indium (TMI). Then, also the temperature of a 960 ℃ and, as described above, the semiconductor layer 916 made of p-type GaN by using Cp ₂ Mg in for using TMG and NH _3, and the p-type impurity provided as a growth gas set Can be formed. The quantum well layer may also include a p-type AlGaN layer as an electron block layer between the InGaN layer and the p-type GaN layer. In addition, a multi-quantum well structure may be formed by alternately stacking a GaN barrier layer and an InGaN quantum well layer.

Next, as shown in FIG. 80, after the catalyst metal 913 (shown in FIG. 79) is removed by wet etching, the conductive film 917 is formed on the surface of the semiconductor layer 916 as shown in FIG. .

Next, as shown in FIG. 82, the front end part 917b (shown in FIG. 81) except the cylindrical part 917a among the conductive films 917 by anisotropic dry etching (RIE), and the board | substrate side part 917c (FIG. Removed).

83, the area | region except the part which covers the semiconductor core 914 of the semiconductor layer 916 and the quantum well layer 915 is removed by dry etching. In FIG. 83, the semiconductor core 914 is covered with the quantum well layer 915a, the semiconductor layer 916a, and the conductive film 917a.

84, the mask 912 (shown in FIG. 83) is removed by wet etching. When the mask is made of silicon oxide (SiO ₂ ), by using a solution containing hydrofluoric acid (HF), the mask can be easily etched without affecting the semiconductor core and the portion of the semiconductor layer covering the semiconductor core.

Next, as shown in FIG. 85, the board | substrate 911 is etched by dry etching. In this case, by using CF ₄ or XeF ₂ , the substrate 911 can be easily etched without affecting the semiconductor core and the portion of the semiconductor layer covering the semiconductor core. Thereby, the convex part 911a is formed in the board | substrate 911 directly under the semiconductor core 914. As shown in FIG.

Subsequently, in the separation step, the semiconductor core is placed on the substrate 911 by immersing the substrate in an isopropyl alcohol (IPA) aqueous solution and vibrating the substrate 911 along the substrate plane using ultrasonic waves (for example, several tens of microseconds). Stress is applied to the semiconductor core 914 covered with the quantum well layer 915a, the semiconductor layer 916a, and the conductive film 917a so that the source close to the substrate 911 side of the 914 is bent. As shown, the semiconductor core 914 covered with the conductive film 917a, the semiconductor layer 916a, and the quantum well layer 915a is separated from the substrate 911.

In this way, the fine rod-shaped structure light emitting element 918 separated from the substrate 911 can be manufactured. In the thirty-fifth embodiment, the rod-shaped structure light emitting element 918 has a diameter of 1.5 m and a length of 25 m. In addition, the cross section of the rod-shaped structure light emitting element 918 has an equilateral triangle shape as shown in FIGS. 87C and 87D described later.

Subsequently, the rod-shaped structure light emitting element 918 manufactured by the rod-shaped structure light emitting element manufacturing method is arranged on an insulating substrate. Arrangement of this rod-shaped structure light emitting element 918 is performed using the manufacturing method of the display apparatus of 38th Embodiment mentioned later, and it demonstrates below according to FIG. 87A-94D. In addition, in FIGS. 87A-94D, the same structural part as the rod-shaped structure light emitting element 918 shown in FIG. 86 has the same reference numeral.

In addition, although the cross section of this rod-shaped structure light emitting element 918 was made into an equilateral triangle shape, the cross-sectional shape of the rod-shaped structure light emitting element is not limited to this, and the cross section may be hexagonal, circular or elliptic rod-shaped, You may apply this invention to the manufacturing method of the rod-shaped structure light emitting element which has another polygonal rod-shaped semiconductor core.

87A is a plan view showing a step of a method of manufacturing a display device using the rod-shaped structure light emitting element 918 shown in FIG. 86, and FIG. 87B is a sectional view of the display device as seen from a line F27B-F27B in FIG. 87A, and FIG. 87A is a cross-sectional view of the display device seen from the line F27C-F27C in FIG. 87A, and FIG. 87D is a cross-sectional view of the display device as viewed from the line F27D-F27D in FIG. 87A.

First, as shown in FIGS. 87A to 87D, after the rod-shaped structure light emitting device 918 is arranged on an insulating substrate 930 on which an array region of two or more electrodes to which independent potentials are applied is formed, Washing is performed. The method of arranging the rod-shaped structure light emitting element 918 in a predetermined direction on the insulating substrate 930 in a predetermined direction is described in detail in the fifth embodiment, and detailed description thereof is omitted here.

As shown in FIG. 87B, metal electrodes 931 and 932 are formed on the surface of the insulating substrate 930 at predetermined intervals, and an insulating film 133 is formed to cover the metal electrodes 931 and 932. The insulating substrate 930 is a substrate having a silicon oxide film formed on an insulator such as glass, ceramic, aluminum oxide, resin, or a semiconductor surface such as silicon, and having an insulating surface. When using a glass substrate, it is preferable to form the base insulating film, such as a silicon oxide film and a silicon nitride film, on the surface. In addition, there may be no insulating film covering the metal electrode.

The metal electrodes 931 and 932 are formed in a desired electrode shape using a printing technique. Further, the metal film and the photoconductor film may be laminated uniformly, and the desired electrode pattern may be exposed and etched to form.

Here, portions having a length of 3 μm at both ends of the rod-shaped structure light emitting element 918 overlap the metal electrodes 931 and 932, respectively.

Although omitted in FIGS. 87A to 87D, pads are formed in the metal electrodes 931 and 932 so that a potential is applied from the outside. In FIGS. 87A-87D, although the arrangement area which arranges rod-shaped structure light emitting element is arrange | positioned, you may arrange | position arbitrary number.

In addition, although the rod-shaped structure light emitting element 918 is arranged to span the two metal electrodes 931 and 932 on the insulating substrate 930, there are two kinds of randomness in the direction as described later. Directions in which the rod-shaped structure light emitting element 918 and the rod-shaped structure light emitting element 918 are reversed left and right shown in Figs. 87A to 87D (both are indistinguishable in the light emitting element 918 of the 35th embodiment). ]to be. In the manufacturing method of the display device of the thirty-eighth embodiment, since the two directions cannot be determined intentionally, the two directions appear with a probability of 50% each.

88A is a plan view illustrating a process of the method of manufacturing the display device subsequent to FIGS. 87A to 87D, FIG. 88B is a cross-sectional view of the display device as seen from a line F28B-F28B in FIG. 88A, and FIG. 88C is an F28C- view in FIG. 88A. 88D is a cross-sectional view of the display device seen from the line F28D-F28D in FIG. 88A.

88A to 88D, after applying the resist 940 onto the insulating substrate 930, patterning is performed by lithography, and one end (left end in FIG. 88A) of the rod-shaped structure light emitting device 918 is shown. Expose

89A is a plan view showing a step of the method of manufacturing the display device subsequent to FIGS. 88A to 88D, FIG. 89B is a cross-sectional view of the display device as viewed from a line F29B-F29B in FIG. 89A, and FIG. 89C is a view of FIG. 89A. Sectional drawing of the display device seen from the line F29C-F29C, FIG. 89D is sectional drawing of the display device seen from the line F29D-F29D of FIG. 89A.

89A to 89D, after the conductive film 917a is removed by wet etching using the patterned resist 940, a portion of the semiconductor layer 916a and the quantum well layer 915a are dried by dry etching. To obtain the exposed portion 914a of the semiconductor core 914. In this manner, the semiconductor core 914 on one side of the rod-shaped structure light emitting element 918 can be exposed.

As described above, when arranging the rod-shaped structure light emitting device 918 on the insulating substrate 930 in FIGS. 87A to 87D, two directions may be taken. Here, two directions occur because the directions in which the left and right sides of the rod-shaped structure light emitting element 918 are changed in FIG. 87A to 87D are distinguished from each other. First of all, since the rod-shaped structure light emitting element 918 is symmetrical even if the left and right sides are reversed, the rod-shaped structure light emitting elements of the thirty-first to thirty-fourth embodiments can be distinguished, for example, when such a change is made. In the manufacturing method of the rod-shaped structure light emitting element of the thirty-fifth embodiment, after the rod-shaped structure light emitting element 918 is arranged on the insulating substrate 930 (FIG. 87), the semiconductor 914 of the rod-shaped structure light emitting element 918 is arranged. The exposure process (FIG. 89) exposing a part of the outer circumferential surface of the C-type cross section is performed, so that the rod-shaped structure light emitting element 918 arranged on the insulating substrate 930 no matter in which direction the rod-shaped structure light emitting element 918 is arranged. A portion of the outer circumferential surface of the semiconductor core 914 on the predetermined side of the s can be exposed. Therefore, when arranging the rod-shaped structure light emitting element 918 on the insulating substrate 930, it is not necessary to arrange the direction in alignment. The rod-shaped structure light emitting element 918 is a diode having an anode electrode and a cathode electrode, and it is important to align the directions thereof, and according to this thirty-fifth embodiment, the process of aligning such directions becomes unnecessary, so that the process can be simplified. have.

Next, FIG. 90A is a plan view showing the process of the manufacturing method of the display device following FIG. 89A to FIG. 89D, FIG. 90B is a sectional view of the display device as seen from the line F30B-F30B in FIG. 90A, and FIG. 90C is the F30C- in FIG. 90A. FIG. 90D is a cross-sectional view of the display device as seen from the line F30D-F30D in FIG. 90A. 91A is a plan view illustrating a process of the method of manufacturing the display device subsequent to FIGS. 90A to 90D, FIG. 91B is a cross-sectional view of the display device as viewed from a line F31B-F31B in FIG. 91A, and FIG. 91C is an F31C- view in FIG. 91A. FIG. 91D is a cross-sectional view of the display device as seen from the line F31D-F31D in FIG. 91A.

90A to 90D, an insulating film 941 made of SiO ₂ is formed on the insulating substrate 930, and thereafter, as shown in FIGS. 91A to 91D, the insulating film 941 made of SiO ₂ is formed. Is etched by dry etching. At this time, the quantum well layer 915a and the semiconductor layer 916a between the semiconductor core 914 and the insulating substrate 930 are not exposed without removing all of the insulating film 941 made of SiO ₂ , and the insulating film 941 is not exposed. Is surrounded by SiO ₂ and etched to expose the exposed region 914a of the semiconductor core 914 (see FIG. 91C).

Next, FIG. 92A is a plan view showing a process of the method of manufacturing the display device subsequent to FIGS. 91A to 91D, FIG. 92B is a cross-sectional view of the display device as viewed from the line F32B-F32B in FIG. 92A, and FIG. 92C is an F32C- view in FIG. 92A. FIG. 92D is a cross-sectional view of the display device as seen from the line F32D-E32D in FIG. 92A.

After peeling the resist 940 used for the said etching, as shown in FIGS. 92A-92D, after apply | coating the resist 942 again, patterning is performed by the lithographic method and the end of the rod-shaped structure light emitting element 918 is carried out. The exposed region 914a of the semiconductor core 914 is exposed, and the conductive film 917a is exposed at the other end of the rod-shaped structured light emitting device 918.

Next, FIG. 93A is a plan view showing a process of the method of manufacturing the display device following FIG. 92A to FIG. 92D, FIG. 93B is a cross-sectional view of the display device as viewed from the line F33B-F33B in FIG. 93A, and FIG. 93C is an F33C- view in FIG. 93A. FIG. 93D is a cross-sectional view of the display device as seen from the line F33D-F33D in FIG. 93A. 94A is a plan view illustrating a process of the method of manufacturing the display device subsequent to FIGS. 93A to 93D, FIG. 94B is a cross-sectional view of the display device as seen from a line F34B-F34B in FIG. 94A, and FIG. 94C is an F34C- view in FIG. 94A. FIG. 94D is a cross-sectional view of the display device as viewed from the line F34D-F34D in FIG. 94A.

93A to 93D, a metal layer 943 is formed by depositing a metal by a vapor deposition method or a sputtering method, and then lift-off is performed as shown in FIGS. 94A to 94D.

As a result, the rod-shaped structure light emitting device 918 connects one electrode 943A to the exposed portion 914a of the semiconductor core 914 and connects the other electrode 943B to the conductive film 917a. An outer circumferential surface of the n-type semiconductor core 914 and an inner circumferential side of the p-type semiconductor layer 916a by flowing a current from the p-type semiconductor layer 916a through the conductive film 917a to the n-type semiconductor core 914. Recombination of electrons and holes occurs at the pn junction of, resulting in light emission. Since light is emitted from the entire circumference of the semiconductor core 914 covered with the semiconductor layer 916a, the light emitting area is widened, so that high light emission efficiency is obtained.

In the thirty-fifth embodiment, by using ITO (indium tin oxide) for the conductive film 917a formed on the semiconductor layer 916a, the semiconductor layer is connected to the electrode through the transparent conductive film, so that the current is concentrated in the electrode connection portion. It is possible to form a wide current path to emit the whole device without biasing, thereby further improving luminous efficiency. The conductive film is not limited to this, and a laminated metal film of Ag / Ni having a thickness of 5 nm may be used, for example.

According to the manufacturing method of the rod-shaped structure light emitting element of the above structure, the fine rod-shaped structure light emitting element 918 which has high degree of freedom of mounting to an apparatus can be manufactured. In addition, since the rod-shaped structure light emitting device 918 is used as a microstructure separated from the substrate, it is possible to reduce the amount of semiconductor used, and to reduce the thickness and weight of the device using the light emitting device, and to provide a semiconductor layer ( Since light is emitted from the entire circumference of the semiconductor core 914 covered by 916a, the light emitting area is widened, and thus, a backlight, a lighting device, a display device, and the like, which have high luminous efficiency and can be realized.

In addition, since the exposure step is performed later than the separation step, the process until the rod-shaped structure light emitting element 918 is separated from the substrate is small, so that the rod-shaped structure light emitting element 918 can be produced with high yield.

In the semiconductor layer forming step, a part of the outer circumferential surface of the semiconductor core 914, which is a portion to be exposed by a mask 912 made of a material that inhibits the formation of the semiconductor layer 916, is covered and then the mask ( By removing 912, a portion of the outer circumferential surface of the semiconductor core 914 can be easily exposed. Here, a material capable of selectively etching a semiconductor core such as silicon oxide (SiO ₂ ) and a semiconductor layer as a material that inhibits the formation of the semiconductor layer 916 is used, but a material that inhibits the formation of the semiconductor layer is not limited thereto. It may be appropriately selected depending on the composition of the semiconductor layer.

In addition, in the separation step, a source close to the substrate 911 side of the semiconductor core 914 which is installed on the substrate 911 by vibrating the substrate 911 along the plane of the substrate 911 using ultrasonic waves is bent. Stress is applied to the semiconductor core 914 covered with the semiconductor layer 916a so that the semiconductor core 914 covered with the semiconductor layer 916a is separated from the substrate 911. Therefore, a plurality of minute rod-shaped light emitting elements 918 provided on the substrate 911 can be easily separated by a simple method.

In the separation step, the semiconductor core 914 may be mechanically separated from the substrate 911 using a cutting tool. A source close to the substrate 911 side of the semiconductor core 914 that is installed on the substrate 911 by using a cutting tool is bent, and stress is applied to the semiconductor core 914 covered by the semiconductor layer 916a. In operation, the semiconductor core 914 covered with the semiconductor layer 916a is separated from the substrate 911. In this case, a plurality of fine rod-shaped light emitting elements 918 provided on the substrate 911 can be separated in a short time by a simple method.

In addition, since the rod-shaped structure light emitting element 918 is almost symmetrical with respect to a straight line passing through the midpoint in the longitudinal direction and perpendicular to the longitudinal direction, the arrangement is easier. As a result, the high yield can be more reliably performed.

Further, the rod-shaped structure light emitting element 918 is arranged in an exposure process in which a portion of the outer circumferential surface of the semiconductor core 914 is exposed after the rod-shaped structure light emitting element 918 is arranged on an array substrate (insulating substrate 930). Is a structure substantially symmetric in the longitudinal direction, and the outer peripheral surface of one end of the semiconductor core 914 can be exposed by removing the quantum well layer 915a, the semiconductor layer 916a, and the conductive film 917a at a desired place. It is not necessary to arrange and arrange the polarities of the two rod-shaped light emitting elements (light emitting diodes), and the process of aligning the polarity (direction) of the plural rod-shaped light emitting elements (light emitting diodes) is unnecessary at the time of manufacture. It can be simplified. In addition, there is no need to provide a mark on the rod-shaped structured light emitting element in order to identify the polarity (direction) of the rod-shaped structured light emitting element (light emitting diode), and the rod-shaped structured light emitting element does not need to have a special shape for polarity identification. do. Therefore, the manufacturing process of a rod-shaped structure light emitting element can be simplified, and manufacturing cost can also be suppressed. In addition, when the size of the light emitting diode is small or the number of light emitting diodes is large, the manufacturing process can be significantly simplified as compared with arranging the light emitting diodes with polarity aligned.

Further, after the exposure step, the exposed portion 914a of the semiconductor core 914 is connected to the n-side electrode, and the other end of the semiconductor core 914 is covered with a quantum well layer, a semiconductor layer, and a conductive film, thereby forming a portion of the conductive film. The p-side electrode can be connected to the. As a result, the electrodes can be easily connected to both ends of the fine rod-shaped light emitting device.

In addition, in the rod-shaped light emitting device manufactured by the method of manufacturing the rod-shaped light emitting device, the semiconductor layer 916 crystal grows radially outward from the outer peripheral surface of the semiconductor core 914, and the growth distance in the radial direction is short. In addition, since the defect is avoided outwardly, the semiconductor core 914 can be covered by the semiconductor layer 916 having fewer crystal defects. Therefore, a rod-shaped structure light emitting device having good characteristics can be realized.

In the thirty-first to thirty-fifth embodiments, a GaN-based semiconductor was used for the substrates 811 to 841, the semiconductor cores 813 to 843, 914, and the semiconductor layers 814a, 825a, 834a, 845a, and 916a, but GaAs and AlGaAs were used. The present invention may be applied to a light emitting element using a semiconductor having GaAsP, InGaN, AlGaN, GaP, ZnSe, AlGaInP, or the like as a base material. Moreover, although the board | substrate and the semiconductor core are n-type and the semiconductor layer was p-type, you may apply this invention to the manufacturing method of the rod-shaped structure light emitting element whose electroconductive type is the opposite. Moreover, although the manufacturing method of the rod-shaped structure light emitting element which has a hexagonal pillar shape and a triangular pillar-shaped semiconductor core was demonstrated, it is not limited to this, The cross-section may be round shape or an elliptical rod shape, and the cross section may be a triangle shape, etc. You may apply this invention to the manufacturing method of the rod-shaped structure light emitting element which has the rod-shaped semiconductor core which is another polygonal shape.

In the first to thirty-fifth embodiments, the rod-shaped structure light emitting device had a diameter of 1 μm or 1.5 μm and a micro order size of 10 μm to 30 μm in length, but at least the diameter or length of the nanoparticles was less than 1 μm. It may be an element of an order size. The diameter of the semiconductor core of the rod-shaped structure light emitting device is preferably 500 nm or more and 50 μm or less, and the variation in the diameter of the semiconductor core can be suppressed as compared with the rod-shaped structure light emitting device of several tens of nm to several hundred nm. The deviation of the luminescence properties can be reduced and the yield can be improved.

In the first to thirty-fifth embodiments, the semiconductor cores 813, 823, 833, 843, 914 are grown by using a MOCVD apparatus, but the semiconductor core may be formed by using another crystal growth apparatus such as a molecular beam epitaxial (MBE) apparatus. In the first to thirty-fourth embodiments, the semiconductor core was crystal-grown on the substrate by using a mask having growth holes. The crystal may be grown.

In the 31st to 35th embodiments, the semiconductor cores 813 to 843 and 914 covered with the semiconductor layers 814a, 825a, 834a, 845a, and 916a are separated from the substrates 811 to 841 and 911 using ultrasonic waves. It is not limited to this, You may mechanically bend and isolate a semiconductor core from a board | substrate using a cutting tool. In this case, a plurality of fine rod-shaped structure light emitting elements provided on the substrate can be separated in a short time by a simple method.

In the thirty-first to thirty-fifth embodiments, a transparent electrode made of ITO (tin-added indium oxide) may be formed on the semiconductor layers 814a, 825a, 834a, 845a, and 916a. As a result, by connecting the semiconductor layer to the electrode through the transparent electrode, a wide current path can be formed to emit the entire element without concentrating and biasing the current in the electrode connection portion, thereby further improving the luminous efficiency. In addition, a transparent electrode is not limited to this, For example, the laminated metal film of Ag / Ni of thickness 5nm, etc. may be used.

In the thirty-fifth embodiment, although the potential difference is applied to the two metal electrodes 931 and 932 formed on the surface of the insulating substrate 930, the rod-shaped structure light emitting device 918 is arranged between the metal electrodes 931 and 932. It is not limited, You may form a 3rd electrode between two electrodes formed in the surface of an insulated substrate, and apply a voltage independent to three electrodes, and arrange | position a rod-shaped structure light emitting element at the position prescribed | regulated by an electrode.

In addition, although the display apparatus provided with the rod-shaped structure light emitting element was demonstrated in the said 35th Embodiment, it is not limited to this, The rod-shaped structure light emitting element manufactured by the manufacturing method of the rod-shaped structure light emitting element of this invention is described. You may apply to other apparatuses, such as a backlight and a lighting apparatus.

Moreover, the manufacturing method of the rod-shaped structure light emitting element of this invention,

A semiconductor core forming step of forming a rod-shaped first conductive semiconductor core on a substrate,

A semiconductor layer forming step of forming a cylindrical second conductive semiconductor layer covering a surface of the semiconductor core;

An exposure step of exposing a portion of an outer circumferential surface of the semiconductor core;

And a separating step of separating the semiconductor core including the exposed portion exposed in the exposing step from the substrate.

According to the said structure, after forming a rod-shaped 1st conductivity type semiconductor core on a board | substrate, a cylindrical 2nd conductivity type semiconductor layer is formed so that the surface of a semiconductor core may be covered. Here, the end surface on the opposite side to the substrate of the semiconductor core may be covered with a semiconductor layer or may be exposed. Then, after exposing a part of the outer circumferential surface of the semiconductor core, the semiconductor core including the exposed portion is separated from the substrate, for example by vibrating the substrate by ultrasonic waves or by using a cutting tool. The rod-shaped structure light emitting device separated from the substrate in this way connects one electrode to the exposed portion of the semiconductor core and the other electrode to the semiconductor layer, thereby connecting the electrons at the pn junction between the outer circumferential surface of the semiconductor core and the inner circumferential surface of the semiconductor layer. Light is emitted from the pn junction by flowing a current between the electrodes to cause recombination of the holes. In this way, a fine rod-shaped structure light emitting device having a high degree of freedom in mounting to an apparatus can be manufactured. Here, the fine rod-shaped light emitting device is, for example, a micro order size having a diameter of 1 μm and a length of 10 μm, or a nano order size having at least a diameter of less than 1 μm in diameter or length. In addition, the rod-shaped structured light emitting device can reduce the amount of semiconductor used, and it is possible to reduce the thickness and weight of the device using the light emitting device and to emit light from the entire circumference of the semiconductor core covered with the semiconductor layer. Since the light emitting area is wider, a high luminous efficiency and a power saving backlight, lighting device, display device, and the like can be realized.

Moreover, in the manufacturing method of the rod-shaped structure light emitting element of one embodiment,

In the exposure step, the outer peripheral surface of the substrate side of the semiconductor core is exposed,

In the semiconductor layer forming step, the end surface on the side opposite to the substrate of the semiconductor core is covered with the semiconductor layer.

According to the said embodiment, in the said exposure process, while exposing the outer peripheral surface of the board | substrate side of a semiconductor core, and covering the end surface of the side opposite to the board | substrate of a semiconductor core in the said semiconductor layer formation process with a semiconductor layer, The other electrode is connected to a part of the semiconductor layer which covers the side opposite to the substrate of the semiconductor core by connecting the exposed portion on the substrate side to one electrode and the end face of the side opposite to the substrate of the semiconductor core is covered with the semiconductor layer. Can be connected. As a result, the electrodes can be easily connected to both ends of the fine rod-shaped light emitting device.

Moreover, in the manufacturing method of the rod-shaped structure light emitting element of one embodiment,

In the separation step, the semiconductor core covered with the semiconductor layer is separated from the substrate using ultrasonic waves.

According to the said embodiment, in the said separation process, the semiconductor core covered with the semiconductor layer is isolate | separated from a board | substrate using an ultrasonic wave. For example, by vibrating the substrate along the substrate plane using ultrasonic waves, stress acts so that a source close to the substrate side of the semiconductor core placed on the substrate is bent so that the semiconductor core covered with the semiconductor layer is separated from the substrate. Therefore, a plurality of fine rod-shaped structure light emitting elements provided on the substrate can be easily separated by a simple method.

Moreover, in the manufacturing method of the rod-shaped structure light emitting element of one embodiment,

In the separation step, the semiconductor core is mechanically separated from the substrate using a cutting tool.

According to the said embodiment, in the said separation process, the semiconductor core is mechanically isolate | separated from a board | substrate using a cutting tool, and can isolate | separate the fine several rod-shaped light emitting element provided on the board | substrate by a simple method in a short time.

Moreover, in the manufacturing method of the rod-shaped structure light emitting element of one embodiment,

The semiconductor core and the semiconductor layer is made of a semiconductor based on GaN,

Dry etching is used in the exposure step.

According to the said embodiment, a part of the outer peripheral surface of the semiconductor core which consists of a semiconductor which uses GaN as a base material can be easily exposed by using dry etching in the said exposure process. Since a semiconductor based on GaN is difficult to wet etch, when the semiconductor core and the semiconductor layer are made of a semiconductor based on GaN, it is easy to mount a part of the outer peripheral surface of the semiconductor core by dry etching in advance before the separation process. It is especially effective in realizing a fine rod-shaped light emitting device.

Moreover, in the manufacturing method of the rod-shaped structure light emitting element of one embodiment,

In the exposing step, the outer circumferential surface of the semiconductor core is exposed to be continuous with the outer circumferential surface of the semiconductor layer without a step.

According to the said embodiment, in the said exposure process, after exposing the outer peripheral surface of a semiconductor core so that it may be continued with the outer peripheral surface of a semiconductor layer without a step, the fine rod-shaped structure light emitting element after separation will be axially oriented with respect to the board | substrate plane on the insulating substrate in which an electrode was formed. When mounted in parallel, there is no step between the outer circumferential surface of the semiconductor layer and the exposed portion of the outer circumferential surface of the semiconductor core, so that the exposed portion of the semiconductor core and the electrode can be reliably and easily connected.

Moreover, in the manufacturing method of the rod-shaped structure light emitting element of one embodiment,

In the exposure step, the outer circumferential surface of the region covered with the semiconductor layer of the semiconductor core and the outer circumferential surface of the exposed region of the semiconductor core are continuous.

According to the said embodiment, in the said exposure process, since the outer peripheral surface of the area | region covered with the semiconductor layer of the semiconductor core and the outer peripheral surface of the exposed area | region of the semiconductor core are made continuous, the exposed area | region of a semiconductor core becomes thin, so that a semiconductor core in the said separation process is carried out. It becomes easy to bend at the board | substrate side of the exposed area | region of the, and separation becomes easy.

Moreover, in the manufacturing method of the display apparatus of this invention,

As a manufacturing method of a display device provided with the rod-shaped structure light emitting element manufactured by the manufacturing method of any one of said rod-shaped structure light emitting elements,

A substrate creation step of creating an insulating substrate on which an array region of two or more electrodes to which independent potentials are applied is formed;

A coating step of applying a liquid including the rod-shaped structure light emitting device having a nano order size or micro order size on the insulating substrate,

And an array step of arranging the rod-shaped structure light emitting elements at positions defined by the two or more electrodes by applying the independent voltages to the two or more electrodes, respectively.

According to the said structure, the insulating substrate in which the array area | region formed by the unit of two or more electrodes provided with independent electric potentials each is formed is created, and the said rod-shaped structure light emitting element of nano order size or micro order size is included on this insulating substrate. Apply the liquid. Thereafter, independent voltages are applied to at least the two electrodes, respectively, to arrange the fine rod-shaped structure light emitting elements at positions defined by the two or more electrodes. Thereby, the rod-shaped structure light emitting element can be easily arranged on a predetermined substrate.

In addition, in the method of manufacturing the display device, by using only a fine rod-shaped light emitting device, it is possible to reduce the amount of semiconductor used and to manufacture a display device that can be thinner and lighter. In addition, the rod-shaped structure light emitting device emits light from the entire circumference of the semiconductor core covered with the semiconductor layer, thereby widening the light emitting area, thereby realizing a display device having high luminous efficiency and power saving.

[36th Embodiment]

FIG. 95: is a schematic cross section of the rod structure light emitting element 2001 of 36th Embodiment of this invention.

The rod-shaped structure light emitting device 2001 includes a semiconductor core 2011 made of rod-shaped n-type GaN (gallium nitride) having a substantially circular cross section, and a p covering the outer circumferential surface and the axial end surface of one end side of the semiconductor core 2011. A quantum well layer 2012 made of a type InGaN, a semiconductor layer 2013 made of a p-type GaN covering the quantum well layer 2012, and SiO ₂ covering an outer circumferential surface of an end portion at the other end of the semiconductor core 2011 ( An insulator 2014 made of silicon oxide) or Si ₃ N ₄ (silicon nitride). The semiconductor core 2011 is an example of the first conductive semiconductor layer, the quantum well layer 2012 is an example of the quantum well layer, and the semiconductor layer 2013 is an example of the second conductive semiconductor layer.

The outer peripheral surface of the other end side of the semiconductor core 2011 is covered with the insulator 2014, but the axial end surface 2011a of the other end side of the semiconductor core 2011 is not covered with the insulator 2014 and exposed. Here, the insulator 2014 covers the entire outer peripheral surface of the other end side of the semiconductor core 2011. In addition, instead of the insulator 2014, as shown by the dashed-dotted line in FIG. 95, the one end side of the semiconductor core 2011 among the outer peripheral surfaces which is not covered with the semiconductor layer 2013 in the other end side of the semiconductor core 2011 is shown. Insulator 2014 'covering only a portion near the outer circumferential surface covered with the semiconductor layer 2013 may be formed.

In addition, the semiconductor core 2011 is doped with Si as a donor impurity, while the quantum well layer 2012 and the semiconductor layer 2013 are doped with Mg as an acceptor impurity. Silver is not limited to Si, and acceptor impurities are not limited to Mg.

In addition, a conductive film 2015 made of polysilicon or ITO (indium tin oxide) is formed on the outer circumferential surface of the semiconductor layer 2013. This conductive film 2015 is a film that transmits light from the quantum well layer 2012. The outer circumferential surface of the conductive film 2015 may be formed so as to be continuous with the outer circumferential surface of the insulator 2014 without generating a step. That is, the outer peripheral surface of the conductive film 2015 may be flush with the outer peripheral surface of the insulator 2014.

Hereinafter, the manufacturing method of the rod-shaped structure light emitting device 2001 will be described with reference to FIGS. 96A to 96K.

First, as shown in FIG. 96A, a substrate 2101 made of n-type GaN is prepared. The substrate 2101 may be subjected to substrate cleaning such as detergent or pure water, or substrate processing such as marking, as necessary.

96B, after forming the mask layer 2014A which consists of an insulator on the board | substrate 2101, using the well-known lithographic method and the dry etching method, as shown in FIG. 96C, the board | substrate 2101 is shown. The mask layer 2014B which has the growth hole 2016 is formed on it (insulator formation process). In addition, the growth hole 2016 is an example of a through hole, and the mask layer 2014B is an example of an insulator.

More specifically, after the resist is applied to the surface of the mask layer 2014A, the resist pattern 2017 is formed by exposing and developing. Using this resist pattern 2017 as a mask, dry etching is performed until a part of the surface of the substrate 2101 is exposed. In this way, the mask layer 2014B having the growth holes 2016 is formed on the substrate 2101. In this case, a material that can be selectively etched with respect to the material of the quantum well layer 2012, such as SiO ₂ or silicon nitride (Si ₃ N ₄ ), is used as the material of the mask layers 2014A and 2014B.

Subsequently, a catalyst metal of Ni or Fe is deposited, and as shown in FIG. 96D, an island-shaped catalyst metal portion 2018 made of Ni or Fe is formed on the surface of the substrate 2101 exposed from the growth holes 2016. Is formed (catalyst part forming step). As a result, the catalyst metal layer 19 made of Ni or Fe is formed on the resist pattern 2017. In addition, the volume of the catalyst metal portion 2018 is increased to the extent that the cross-sectional shape of the catalyst metal portion 2018 becomes almost rectangular.

Subsequently, as shown in FIG. 96E, the catalyst metal layer 19 is lifted off by removing the resist pattern 2017, and then washed with pure water, for example.

Subsequently, as shown in FIG. 96F, MOCVD (Metal Organic Chemical) on the surface of the substrate 2101 on which the island-shaped catalyst metal portion 2018 is formed, that is, on the surface of the substrate 2101 overlapping the growth hole 2016. Vapor Deposition: A rod-shaped semiconductor core made of n-type GaN (2011A) by crystal-growing n-type GaN from the interface between the island-shaped catalytic metal part 2018 and the substrate 2101 using an organic metal vapor phase growth device. Is formed (semiconductor core forming step). At this time, the growth temperature is set at about 800 ° C., TMG (trimethylgallium) and NH ₃ (ammonia) are used as the growth gas, and SiH ₄ (silane) is supplied to the n-type impurity supply, and as a carrier gas, By supplying H ₂ , an n-type GaN semiconductor core 2011A using Si as a donor impurity can be grown.

Subsequently, crystal growth from the outer circumferential surface of the semiconductor core 2011A while the island-shaped catalyst metal portion 2018 is held at one end of the semiconductor core 2011A, and the catalyst metal portion 2018 and the semiconductor core 2011 As shown in FIG. 96G, the quantum well layer 2012A made of p-type InGaN and the semiconductor layer 2013A made of p-type GaN are formed by the crystal growth from the interface of (Semiconductor Layer Forming Step). At this time, the growth temperature is set within the range of 750 ° C to 800 ° C, and TMG, NH ₃ and TMI (trimethylindium) are used as growth gases, and Cp ₂ Mg (biscyclopentadienyl magnesium is used for p-type impurity supply). ), And by supplying H ₂ as a carrier gas, p-type InGaN containing Mg as an impurity can be grown. And, setting the growth temperature of about 900 ℃, and using TMG and NH ₃ as a growth _gas, and supplies the Cp ₂ Mg to for the p-type impurity supplied, also, to the Mg by supplying H ₂ as a carrier gas with an impurity P-type GaN can be grown. In addition, the quantum well layer 2012A and the semiconductor layer 2013A are formed to cover the semiconductor core 2011 protruding from the growth hole 2016. The structure of the quantum well layer 2012A may be a single quantum well structure having one well layer, or may be a multi-quantum well structure having a plurality of well layers.

Subsequently, as shown in FIG. 96H, the island-shaped catalyst metal portion 2018 is selectively removed by wet etching at one end of the semiconductor core 2011A, and then washed with pure water, for example. The island-shaped catalyst metal part 2018 may be removed by dry ion etching (reactive ion etching). At this time, by using SiCl ₄ for RIE, etching with GaN can be easily performed.

Subsequently, after annealing for activating the p-type GaN, as shown in FIG. 96I, a conductive film 2015A made of polysilicon or ITO is formed on the semiconductor layer 2013A, and further subjected to annealing to form a semiconductor layer ( The resistance between 2013A) and the conductive film 2015A is lowered.

Subsequently, the conductive film 2015A, the semiconductor layer 2013A, the quantum well layer 2012A, and the mask layer 2014B are sequentially anisotropically etched, and as shown in FIG. 96J, on one side of the semiconductor core 2011. The quantum well layer 2012, the semiconductor layer 2013, and the conductive film 2015 are left, while the insulator 2014 is left on the other end side of the semiconductor core 2011 (insulator etching step). At this time, a part of the semiconductor layer 2013A and the conductive film 2015A is removed, but in the quantum well layer 2012A and the semiconductor layer 2013A, the semiconductor core is larger than the thickness in the radial direction of the portion covering the outer circumferential surface of the semiconductor core 2011. Since the thickness in the axial direction of the portion covering the axial end face on one end side of the 2011 side becomes thick, the axial end face on the one end side of the semiconductor core 2011 is difficult to be exposed. In addition, when anisotropically etching the conductive film 2015A, the semiconductor layer 2013A, the quantum well layer 2012A, and the mask layer 2014B sequentially, by reducing the anisotropy when etching the mask layer 2014B, As indicated by the dashed-dotted line in FIG. 96J, the semiconductor layer 2013 is covered on one end side of the semiconductor core 2011 among the outer peripheral surfaces of the semiconductor core 2011 that are not covered by the semiconductor layer 2013 on the other end side. An insulator 2014 'covering only a portion near the outer circumferential surface may be formed. Insulators 2014 and 2014 'are part of the mask layer 2014B remaining on the substrate 2101. In addition, although one rod structure light emitting element 2001 is shown in FIG. 96J, a plurality of rod structure light emitting elements 2001 are formed.

Subsequently, the semiconductor core 2011 is immersed on the substrate 2101 by immersing the substrate 2101 in an IPA (isopropyl alcohol) aqueous solution and vibrating the substrate 2101 along the substrate plane using, for example, several tens of ultrasonic waves. The stress is applied to the semiconductor core 2011 and the insulator 2014 so that a source close to the substrate 2101 side of the substrate is bent, and as shown in FIG. 96K, the semiconductor core 2011 is separated from the substrate 2101 ( Separation process).

In this manner, a plurality of fine rod-shaped structure light emitting devices 2001 separated from the substrate 2101 can be manufactured. Here, the fine rod-shaped light emitting device is, for example, a size that falls within a range of 10 nm to 5 µm, and a length falls within a range of 100 nm to 200 µm, and more preferably a diameter ranges from 100 nm to 2 µm. It is an element of the size which falls in the range of up to, and whose length falls in the range from 1 micrometer to 50 micrometers.

According to the manufacturing method of the rod-shaped light emitting device having the above structure, since the fine rod-shaped light emitting device 2001 is separated from the substrate 2101, the degree of freedom of mounting the fine rod-shaped light emitting device 2001 to the device can be increased. have.

Further, since the rod-shaped first conductive semiconductor core is formed on the surface of the substrate 2101 overlapping the substrate 2101, the rod-shaped first conductive type semiconductor core can be uniformly formed.

In addition, since the substrate 2101 is separated from the fine rod-shaped light emitting device 2001, the substrate 2101 may not be used when the fine rod-shaped light emitting device 2001 emits light. Therefore, the choice of the substrate used at the time of light emission of the fine rod-shaped light emitting device 2001 increases, and the degree of freedom of the form of the device in which the fine rod-shaped light emitting device 2001 is to be mounted can be increased.

In the separation step, the semiconductor core is bent so that the source close to the substrate 2101 side of the semiconductor core 2011 standing on the substrate 2101 is bent by vibrating the substrate 2101 along the substrate plane using ultrasonic waves. Stress is applied to the 2011 and the insulator 2014 to separate the semiconductor core 2011 and the insulator 2014 from the substrate 2101. Therefore, the plurality of fine rod-shaped structure light emitting elements 2001 provided on the substrate 2101 can be easily separated by a simple method.

If the rod-shaped structure light emitting device 2001 is not provided with the insulator 2014, the stress is concentrated in a location where a step is formed on the outer circumferential surface of the semiconductor core 2011, so that the semiconductor core 2011 is near this location. It becomes easy to bend. In the case where the semiconductor core 2011 is bent at the location, device defects occur. Therefore, since the rod-shaped structure light emitting device 2001 includes an insulator 2014, and the insulator 2014 covers the outer circumferential surface near the location of the semiconductor core 2011, the semiconductor core 2011 is bent near the location. Can be prevented. As a result, even if a plurality of fine rod-shaped light emitting elements 2001 are manufactured, the length of the plurality of fine rod-shaped light emitting elements 2001 can be uniform. In addition, as shown in FIG. 95, the insulator 2014 completely covers the entire outer circumferential surface of the other end side of the semiconductor core 2011 so that the semiconductor core 2011 is prevented from bending at the time of separation as compared to the insulator 2014 '. As a result, the length of the plurality of fine rod-shaped structure light emitting elements 2001 can be reliably uniformly.

In addition, the substrate 2101 can be reused in the manufacture of the fine rod-shaped light emitting device 2001 after the fine rod-shaped light emitting device 2001 is separated, thereby reducing the manufacturing cost.

In addition, since the rod-shaped structure light emitting device 2001 is fine, the amount of semiconductor used can be reduced. Therefore, the device to which the rod-shaped structure light emitting device 2001 is to be mounted can be made thinner and lighter, and the load on the environment can be reduced.

In addition, in the catalyst portion forming step, the volume of the island-shaped catalyst metal portion 2018 formed in the growth hole 2016 is increased so that the cross-sectional shape of the catalyst metal portion 2018 becomes substantially rectangular, thereby forming the next semiconductor core. In the process, the diameter of the portion outside the growth hole 2016 of the rod-shaped semiconductor core 2011A is larger than the diameter of the portion in the growth hole 2016 of the rod-shaped semiconductor core 2011A. Therefore, a wide light emitting area can be obtained by making pn junction large.

Further, in the semiconductor forming step, a quantum well made of p-type InGaN is formed while the island-like catalyst metal portion 2018 is held at one end of the semiconductor core 2011A without removing the island-shaped catalyst metal portion 2018. Since the semiconductor layer 2013A formed of the layer 2012A and the p-type GaN is formed, crystal growth from the interface between the catalyst metal portion 2018 and the semiconductor core 2011 is promoted rather than crystal growth from the outer circumferential surface of the semiconductor core 2011A. do. That is, the rate of crystal growth from the interface between the catalyst metal portion 2018 and the semiconductor core 2011 is 10 to 100 times the rate of crystal growth from the outer circumferential surface of the semiconductor core 2011A. Accordingly, the axial direction of the portion of the quantum well layer 2012A and the semiconductor layer 2013A that covers the axial end surface of one end side of the semiconductor core 2011 rather than the thickness of the radial direction of the portion of the semiconductor core 2011 that covers the outer circumferential surface thereof. The thickness of can be easily thickened. As a result, since the axial end surface of the one end side of the semiconductor core 2011 is hard to be exposed, the p-side electrode can be prevented from being connected to the axial end surface of the one end side of the n-type semiconductor core 2011.

In addition, in the fine rod-shaped light emitting device 2001 manufactured by the method for manufacturing the rod-shaped light emitting device, the n-side electrode is formed on the axial end surface 2011a of the semiconductor core 2011 that is not covered with the insulator 2014. The p-side electrode is connected to the conductive film 2015 or the surface of the semiconductor layer 2013 exposed from the conductive film 2015, and the n-type semiconductor core 2011 is connected from the p-type semiconductor layer 2013. The flow of the furnace current causes recombination of electrons and holes in the quantum well layer 2012 to emit light. At this time, since the quantum well layer 2012 and the semiconductor layer 2013 are formed to cover the entire circumferential surface and the axial end surface of one end side of the semiconductor core 2011, light is emitted from almost all of the quantum well layer 2012. It is emitted and the light emitting area is widened. Therefore, the light emission amount can be increased and the light emission efficiency can be improved.

In addition, since the light emitting efficiency of the rod-shaped structure light emitting device 2001 can be improved, the light emitting efficiency and the power-saving backlight, lighting device, and display device can be realized by using the rod-shaped structure light emitting device 2001.

In addition, by forming the quantum well layer 2012 between the semiconductor core 2011 and the semiconductor layer 2013, the amount of light emission can be increased by the quantum confinement effect of the quantum well layer 2012 and the light emission efficiency is higher. can do.

In addition, since the axial end surface 2011a of the semiconductor core 2011 is exposed, the n-side electrode can be easily connected to the axial end surface 2011a.

Further, an insulator (a portion of the outer circumferential surface that is not covered with the semiconductor layer 2013 on the other end side of the semiconductor core 2011 near the outer circumferential surface covered with the semiconductor layer 2013 on one end side of the semiconductor core 2011 is insulated ( 2014), it is difficult for the n-side electrode to be short-circuited with the p-side electrode, so that the formation of the n-side electrode and the p-side electrode is easy. That is, even if the p-side electrode to be connected to the semiconductor layer 2013 is formed near the step of the outer circumferential surface of the semiconductor core 2011, the p-side electrode is prevented from contacting the semiconductor core 2011, so the n-side electrode and the p-side electrode Is easy to form. This effect is also obtained when the insulator 2014 'is formed instead of the insulator 2014.

In addition, in the fine rod-shaped light emitting device 2001 manufactured by the method of manufacturing the rod-shaped light emitting device, the quantum well layer 2012A and the semiconductor layer 2013A are radially outward from the outer circumferential surface of the semiconductor core 2011A. Crystals grow, the growth distance in the radial direction is short, and defects are avoided outwardly. Therefore, since the one end side of the semiconductor core 2011 can be covered by the quantum well layer 2012 and the semiconductor layer 2013 having few crystal defects, the characteristics of the fine rod-shaped structure light emitting device 2001 can be improved.

In addition, when the rod-shaped light emitting device 2001 is disposed on the substrate so that the axial direction of the rod-shaped light emitting device 2001 is parallel to the surface of the substrate, the outer circumferential surface of the conductive film 2015 is the insulator 2014. It is formed so as to be continuous with the outer circumferential surface of the rod-shaped structure light emitting device 2001 to prevent damage, and the rod-shaped structure light emitting device 2001 is inclined with respect to the surface of the substrate to become unstable Can be prevented.

Further, since the rod-shaped light emitting device 2001 is prevented from being inclined with respect to the surface of the substrate, the contact area of the rod-shaped light emitting device 2001 with respect to the surface of the substrate is increased, so that the rod-shaped light emitting device 2001 ( Heat of 2001) easily diffuses into the substrate.

[37th Embodiment]

FIG. 97: is a schematic cross section of the rod-shaped structure light emitting element 2002 of 37th Embodiment of this invention.

The rod-shaped structure light emitting device 2002 has a semiconductor core 2021 made of a rod-shaped n-type GaN (gallium nitride) having a substantially circular cross section, and a p covering the outer circumferential surface and the axial end surface of one end side of the semiconductor core 2021. A quantum well layer 2022 made of type InGaN, a semiconductor layer 2023 made of p-type GaN covering the quantum well layer 2022, and SiO ₂ (silicon oxide) covering an outer circumferential surface of the other end side of the semiconductor core 2021. ) Or an insulator 2024 made of Si ₃ N ₄ (silicon nitride), and a base layer 2030 connected to the other end of the semiconductor core 2021. The semiconductor core 2021 is an example of a first conductive semiconductor layer, the quantum well layer 2022 is an example of a quantum well layer, and the semiconductor layer 2023 is an example of a second conductive semiconductor layer, and an underlayer ( 2030 is an example of the underlayer of a 1st conductivity type.

The surface of the semiconductor core 2021 is covered with a quantum well layer 2022 or an insulator 2024. Here, the insulator 2024 covers the entire outer peripheral surface of the other end side of the semiconductor core 2021. In addition, instead of the insulator 2024, as shown by the dashed-dotted line in FIG. 97, the one end side of the semiconductor core 2021 among the outer peripheral surfaces which is not covered with the semiconductor layer 2023 on the other end side of the semiconductor core 2021. Insulator 2024 'covering only a portion near the outer circumferential surface covered with the semiconductor layer 2023 may be formed.

The axial end surface 2030a on the side opposite to the semiconductor core 2021 side of the base layer 2030 is exposed without being covered with the insulator 2024. In addition, the circumferential surface 2030b of the base layer 2030 is also not exposed by the insulator 2024 and is exposed.

The semiconductor core 2021 is doped with Si as a donor impurity, while the quantum well layer 2022 and the semiconductor layer 2023 are doped with Mg as an acceptor impurity, but the donor impurity is not limited to Si. Also, acceptor impurities are not limited to Mg.

Furthermore, a conductive film 2025 made of polysilicon or ITO (indium tin oxide) is formed on the outer circumferential surface of the semiconductor layer 2023. The conductive film 2025 is a film that transmits light from the quantum well layer 2022. The outer circumferential surface of the conductive film 2025 may be formed so as to be continuous with the outer circumferential surface of the insulator 2024 without generating a step. In other words, the outer circumferential surface of the conductive film 2025 may be flush with the outer circumferential surface of the insulator 2024.

Hereinafter, the manufacturing method of the said rod-shaped structure light emitting element 2002 is demonstrated using FIGS. 98A-98M.

First, as shown in FIG. 98A, the board | substrate 2201 which consists of Si, for example is prepared. The substrate 2201 may be subjected to substrate cleaning with detergent or pure water, or substrate processing such as marking, if necessary.

Next, as shown in FIG. 98B, the base layer 2030A which consists of n type GaN is formed on the board | substrate 2201 using a MOCVD apparatus (base layer formation process). At this time, set to about a growth temperature of 950 ℃, and using TMG and NH ₃ as a growth _gas, and supplying the SiH ₄ in the for the n-type impurity supplying Further, Si a donor impurity by supplying H ₂ as a carrier gas The underlying layer 2030A of n-type GaN can be grown.

Subsequently, as shown in FIG. 98C, after forming the mask layer 2024A which consists of an insulator on the board | substrate 2201, using a well-known lithography method and a dry etching method, as shown in FIG. 98D, the board | substrate 2201 is shown. A mask layer 2024B having growth holes 2026 is formed on the surface (insulator formation step). The growth hole 2026 is an example of a through hole, and the mask layer 2024B is an example of an insulator.

More specifically, after the resist is applied to the surface of the mask layer 2024A, the resist pattern 2027 is formed by performing exposure and development. Using this resist pattern 2027 as a mask, dry etching is performed until a part of the surface of the underlying layer 2030A is exposed. In this manner, a mask layer 2024B having growth holes 2026 is formed on the underlayer 2030A. In this case, a material that can be selectively etched with respect to the material of the quantum well layer 2022, such as SiO ₂ or silicon nitride (Si ₃ N ₄ ), is used as the material of the mask layers 2024A and 2024B.

Subsequently, a catalyst metal of Ni or Fe is deposited, and as shown in FIG. 98E, an island-shaped catalyst metal portion 2028 made of Ni or Fe is formed on the surface of the underlying layer 2030A exposed from the growth holes 2026. ) Is formed (catalyst part forming step). As a result, a catalyst metal layer 2029 made of Ni or Fe is formed on the resist pattern 2027. In addition, the volume of the catalyst metal portion 2028 is made large so that the cross-sectional shape of the catalyst metal portion 2028 becomes almost rectangular.

Subsequently, as shown in FIG. 98F, after removing the resist pattern 2027, the catalyst metal layer 2029 is lifted off, and then washed with pure water, for example.

Subsequently, as shown in FIG. 98G, the MOCVD apparatus on the surface of the underlayer 2030A on which the island-shaped catalyst metal portion 2028 is formed, that is, on the surface of the underlayer 2030A overlapping the growth hole 2026. Crystal growth of n-type GaN from the interface between the island-shaped catalyst metal portion 2028 and the underlying layer 2030A by using the N-type GaN to form a rod-shaped semiconductor core 2021A (semiconductor core forming step ). At this time, setting the growth temperature of about 800 ℃, and using TMG and NH ₃ as a growth _gas, and supplying the SiH ₄ to for the n-type dopant supply, and also, the Si by supplying H ₂ as a carrier gas to a donor impurity One n-type GaN semiconductor core 2021A can be grown.

Next, crystal growth from the outer circumferential surface of the semiconductor core 2021A while the island-shaped catalyst metal portion 2028 is held at one end of the semiconductor core 2021A, and the catalyst metal portion 2028 and the semiconductor core 2021 As shown in FIG. 98H, the crystal growth from the interface of the semiconductor layer forms a quantum well layer 2022A made of p-type InGaN and a semiconductor layer 2023A made of p-type GaN (semiconductor layer forming step). At this time, the growth temperature is set within the range of 750 ° C to 800 ° C, TMG, NH ₃ and TMI are used as the growth gas, Cp ₂ Mg is supplied to the p-type impurity supply, and H _{2 is used} as a carrier gas. The p-type InGaN containing Mg as an impurity can be grown by supplying. And, setting the growth temperature of about 900 ℃, and using TMG and NH ₃ as a growth _gas, and supplies the Cp ₂ Mg to for the p-type impurity supplied, also, to the Mg by supplying H ₂ as a carrier gas with an impurity P-type GaN can be grown. In addition, the quantum well layer 2022A and the semiconductor layer 2023A are formed to cover the semiconductor core 2021 protruding from the growth hole 2026. The structure of the quantum well layer 2022A may be a single quantum well structure having one well layer or a multi-quantum well structure having a plurality of well layers.

Subsequently, as shown in FIG. 98I, the island-like catalyst metal portion 2028 is selectively removed at one end of the semiconductor core 2021A by wet etching, and then washed with pure water, for example. The island-shaped catalyst metal portion 2028 may be removed by dry etching RIE. At this time, by using SiCl ₄ for RIE, etching with GaN can be easily performed.

Subsequently, after annealing for activating the p-type GaN, as shown in FIG. 98J, a conductive film 2025A made of polysilicon or ITO is formed on the semiconductor layer 2023A, and annealing is performed to perform the semiconductor layer ( The resistance between 2023A and the conductive film 2025A is lowered.

Subsequently, the conductive film 2025A, the semiconductor layer 2023A, the quantum well layer 2022A, and the mask layer 2024B are sequentially anisotropically etched, and as shown in FIG. 98K, one end side of the semiconductor core 2021 is provided. The quantum well layer 2022, the semiconductor layer 2023, and the conductive film 2025 are left, while the insulator 2024 is left on the other end side of the semiconductor core 2021 (insulator etching step). At this time, a part of the semiconductor layer 2023A and the conductive film 2025A is removed, but in the quantum well layer 2022A and the semiconductor layer 2023A, the semiconductor core is larger than the thickness in the radial direction of the portion covering the outer circumferential surface of the semiconductor core 2021. Since the thickness in the axial direction of the portion covering the axial end face on one end side of the 2021 is thick, the axial end face on the one end side of the semiconductor core 2021 is difficult to be exposed. In addition, when anisotropically etching the conductive film 2025A, the semiconductor layer 2023A, the quantum well layer 2022A, and the mask layer 2024B sequentially, by reducing the anisotropy when etching the mask layer 2024B, As indicated by the dashed-dotted line in FIG. 98K, the semiconductor layer 2023 is covered on one end side of the semiconductor core 2021 among the outer circumferential surfaces of the semiconductor core 2021 that are not covered by the semiconductor layer 2023 on the other end side. An insulator 2024 'covering only a portion near the outer circumferential surface can be formed. Insulators 2024 and 2024 'are part of the mask layer 2024B remaining on the substrate 2201. In addition, although one rod structure light emitting element 2002 is shown in FIG. 98K, a plurality of rod structure light emitting elements 2002 are formed. In addition, the said insulator etching process is an example of an etching process.

Subsequently, RIE is performed on the base layer 2030A to form a base layer 2030 connected to the other end of the semiconductor core 2021 as shown in FIG. 98L (base layer etching step). In addition, the said base layer etching process is an example of an etching process.

Subsequently, the substrate 2201 of the semiconductor core 2021 is immersed on the substrate 2201 by immersing the substrate 2201 in an IPA aqueous solution and vibrating the substrate 2201 along the substrate plane using, for example, several tens of ultrasonic waves. Stress is applied to the semiconductor core 2021 and the insulator 2024 so that the source close to the side is bent, and as shown in FIG. 98M, the base layer 2030 is separated from the substrate 2201 (separation step).

In this way, a plurality of fine rod-shaped structure light emitting elements 2002 separated from the substrate 2201 can be manufactured. Here, the fine rod-shaped light emitting device is, for example, a size that falls within the range of 10 nm to 5 µm, and a length falls within the range of 100 nm to 200 µm, and more preferably from 100 nm to 2 µm in diameter. It is an element of the size which falls in the range of and whose length falls in the range from 1 micrometer to 50 micrometers.

According to the method for manufacturing a rod-shaped light emitting device having the above structure, since the fine rod-shaped light emitting device 2002 is separated from the substrate 2201, the degree of freedom of mounting the fine rod-shaped light emitting device 2002 to the device can be increased. .

In addition, since the rod-shaped first conductive semiconductor core is formed on the surface of the substrate 2201 overlapping the substrate 2201 so as to protrude from the substrate 2201, the thickness of the semiconductor core can be uniform.

In addition, since the substrate 2201 is separated from the fine rod structure light emitting device 2002, the substrate 2201 may not be used when the fine rod structure light emitting device 2002 emits light. That is, connection of the electrode to the board | substrate 2201 becomes unnecessary. Therefore, the choice of the substrate used for the light emission of the fine rod-shaped light emitting device 2002 increases, so that the degree of freedom in the form of the device in which the fine rod-shaped light emitting device 2002 is to be mounted can be increased.

In addition, in the separation step, the semiconductor core is bent so that a source close to the substrate 2201 side of the semiconductor core 2021 installed on the substrate 2201 is oscillated by vibrating the substrate 2201 along the substrate plane using ultrasonic waves. Stress acts on the 2021 and the insulator 2024 to separate the semiconductor core 2021 and the insulator 2024 from the substrate 2201. Therefore, the plurality of fine rod-shaped structure light emitting elements 2002 provided on the substrate 2201 can be easily separated by a simple method.

If the rod-shaped structure light emitting device 2002 does not include the insulator 2024, stress is concentrated at a location where a step is formed on the outer circumferential surface of the semiconductor core 2021 so that the semiconductor core 2021 is located near this location. It becomes easy to bend. In the case where the semiconductor core 2021 is bent at the location, device defects occur. Accordingly, the rod-shaped structure light emitting device 2002 includes an insulator 2024, and the insulator 2024 covers an outer circumferential surface near the location of the semiconductor core 2021 so that the semiconductor core 2021 is bent near the location. Can be prevented. As a result, even if a plurality of fine rod-shaped light emitting elements 2002 are manufactured, the lengths of the plurality of fine rod-shaped light emitting elements 2002 can be uniformized. As shown in FIG. 97, the insulator 2024 completely covers the entire outer circumferential surface of the other end side of the semiconductor core 2021, thereby preventing the semiconductor core 2021 from being bent along the way as compared with the insulator 2024 ′. As a result, the length of the plurality of fine rod-shaped structure light emitting elements 2002 can be reliably uniformly.

In addition, since the substrate 2201 is separated from the fine rod-shaped light emitting device 2002, the substrate 2201 can be reused in manufacturing the fine rod-shaped light emitting device 2002, thereby reducing manufacturing costs.

In addition, since the rod-shaped structure light emitting device 2002 is minute, the amount of semiconductor used can be reduced. Therefore, the device to which the rod-shaped structure light emitting element 2002 is to be mounted can be made thinner and lighter, and the load on the environment can be reduced.

Further, in the catalyst portion forming step, the volume of the island-shaped catalyst metal portion 2028 formed in the growth hole 2026 is increased so that the cross-sectional shape of the catalyst metal portion 2028 becomes almost rectangular, thereby forming the next semiconductor core. In the process, the diameter of the portion outside the growth hole 2026 of the rod-shaped semiconductor core 2021A is larger than the diameter of the portion in the growth hole 2026 of the rod-shaped semiconductor core 2021A. Therefore, a wide light emitting area can be obtained by making pn junction large.

In the semiconductor core forming step, since the semiconductor core 2021A made of n-type GaN is grown on the base layer 2030A made of n-type GaN, the semiconductor core 2021A can be easily crystal-grown. The variation of the initial crystal growth of the semiconductor core 2021A can be reduced.

Further, in the semiconductor forming step, a quantum well made of p-type InGaN in a state where the island-shaped catalyst metal portion 2028 is held at one end of the semiconductor core 2021A without removing the island-shaped catalyst metal portion 2028. Since the semiconductor layer 2023A made of the layer 2022A and the p-type GaN is formed, crystal growth from the interface between the catalyst metal portion 2028 and the semiconductor core 2021 is promoted rather than crystal growth from the outer circumferential surface of the semiconductor core 2021A. do. That is, the rate of crystal growth from the interface between the catalyst metal portion 2028 and the semiconductor core 2021 becomes 10 times to 100 times the rate of crystal growth from the outer circumferential surface of the semiconductor core 2021A. Accordingly, the axial direction of the portion of the quantum well layer 2022A and the semiconductor layer 2023A that covers the axial end surface of one end side of the semiconductor core 2021 rather than the thickness in the radial direction of the portion covering the outer circumferential surface of the semiconductor core 2021. The thickness of can be easily thickened. As a result, since the axial end surface of the one end side of the semiconductor core 2021 is hard to be exposed, the p-side electrode can be prevented from being connected to the axial end surface of the one end side of the n-type semiconductor core 2021.

In addition, in the fine rod-shaped light emitting device 2002 manufactured by the method of manufacturing the rod-shaped light emitting device, the axial end surface 2030a and the insulator 2024 of the base layer 2030 not covered with the insulator 2024 are provided. N-side electrode is connected to at least one of the circumferential surfaces 2030b of the base layer 2030 that are not covered with C), and the surface of the conductive layer 2025 or the semiconductor layer 2023 exposed from the conductive layer 2025 is exposed. By connecting the p-side electrode to the n-type semiconductor core 2021 from the p-type semiconductor layer 2023, electrons and holes are recombined in the quantum well layer 2022 to emit light. At this time, since the quantum well layer 2022 and the semiconductor layer 2023 are formed to cover the entire circumferential surface and the axial end surface of one end side of the semiconductor core 2021, light is emitted from almost all of the quantum well layer 2022. It is emitted and the light emitting area is widened. Therefore, the light emission amount can be increased and the light emission efficiency can be improved.

In addition, since the light emitting efficiency of the rod-shaped structure light emitting device 2002 can be improved, the light emitting efficiency and the power saving backlight, lighting device, and display device can be realized by using the rod-shaped structure light emitting device 2002.

In addition, by forming the quantum well layer 2022 between the semiconductor core 2021 and the semiconductor layer 2023, the light emission amount can be increased by the quantum confinement effect of the quantum well layer 2022 and the light emission efficiency is higher. can do.

In addition, since the axial end surface 2030a and the circumferential surface 2030b of the base layer 2030 are exposed, the n-side electrode can be easily connected to at least one of the axial end surface 2030a and the circumferential surface 2030b. have.

Further, an insulator (a portion of the outer peripheral surface not covered with the semiconductor layer 2023 on the other end side of the semiconductor core 2021 near the outer peripheral surface covered with the semiconductor layer 2023 on one end side of the semiconductor core 2021) is used. 2024), the n-side electrode is less likely to be short-circuited with the p-side electrode, so that the formation of the n-side electrode and the p-side electrode is easy. That is, even if the p-side electrode to be connected to the semiconductor layer 2023 is formed near the step of the outer circumferential surface of the semiconductor core 2021, the p-side electrode can be prevented from contacting the semiconductor core 2021, so that the n-side electrode and p Formation of the side electrode is easy. This effect is obtained even when the insulator 2024 'is formed instead of the insulator 2024.

Further, in the fine rod-shaped light emitting device 2002 manufactured by the method of manufacturing the rod-shaped light emitting device, the quantum well layer 2022A and the semiconductor layer 2023A are radially outward from the outer circumferential surface of the semiconductor core 2021A. Crystals grow, the growth distance in the radial direction is short, and defects are avoided outwardly. Therefore, since the one end side of the semiconductor core 2021 can be covered with the quantum well layer 2022 and the semiconductor layer 2023 with few crystal defects, the characteristic of the fine rod-shaped structure light emitting device 2002 can be improved.

In addition, when the rod-shaped structure light emitting element 2002 is disposed on the substrate so that the axial direction of the rod-shaped structure light emitting element 2002 is parallel to the surface of the substrate, the outer circumferential surface of the conductive film 2025 is the insulator 2024. It is formed to be continuous without generating a step and the outer peripheral surface of the bar structure light emitting device 2002 can be prevented, and the bar structure light emitting device 2002 is inclined with respect to the surface of the substrate becomes unstable Can be prevented.

Further, since the rod-shaped light emitting device 2002 is prevented from being inclined with respect to the surface of the substrate, the contact area of the rod-shaped light emitting device 2002 with respect to the surface of the substrate is increased so that the rod-shaped light emitting device 2002 ( Heat of 2002) tends to diffuse into the substrate.

In the first and thirty-seventh embodiments, a fine rod-shaped structure light emitting device may be manufactured using a semiconductor based on GaAs, AlGaAs, GaAsP, InGaN, AlGaN, GaP, ZnSe, AlGaInP, or the like.

In the 36th and 37th embodiments, the n-type semiconductor cores 2011 and 2021, the p-type quantum well layers 2012 and 2022, the p-type semiconductor layers 2013 and 2023 and the n-type base layer 2030 are provided. ), A p-type semiconductor core, an n-type quantum well layer, an n-type semiconductor layer, and a p-type base layer may be used. That is, you may reverse the conductivity type in the said 36th, 37th embodiment.

In the thirty-sixth and thirty-seventh embodiments, the diameters of the semiconductor cores 2011 and 2021 are 300 nm or more and 50 µm or less, compared with those of the semiconductor cores of several tens of nm to several hundred nm in diameter. Can be suppressed and the light emission area, i.e., the light emission characteristic can be reduced, and the yield can be improved.

In the thirty-sixth and thirty-seventth embodiments, a rod-shaped light emitting device in which quantum well layers 2012 and 2022 and semiconductor layers 2013 and 2023 are coated on one end of rod-shaped semiconductor cores 2011 and 2021 having a substantially circular cross section. Although (2001, 2002) has been described, for example, a rod-shaped structure light emitting device in which a quantum well layer, a semiconductor layer or the like is coated on one end of a rod-shaped semiconductor core that is almost elliptical in cross section, or another polygon such as a hexagon in cross section. You may apply this invention to the rod-shaped structure light emitting element which coat | covered the quantum well layer, the semiconductor layer, etc. on one end side of the semiconductor core of the phase. The n-type GaN becomes hexagonal crystal growth, and grows in a c-axis direction perpendicular to the substrate surface to obtain a substantially hexagonal columnar semiconductor core. Although depending on growth conditions such as growth direction and growth temperature, when the diameters of the growth holes 2016 and 2026 are as small as several tens of nm to several hundred nm, there is a tendency that semiconductor cores having a nearly circular cross section are easily formed. When the diameters of the growth holes 2016 and 2026 are large from about 0.5 mu m to several mu m, there is a tendency that semiconductor cores having a substantially hexagonal cross section are formed.

In the thirty-sixth and thirty-seventth embodiments, the semiconductor cores 2011 and 2021 having one end diameter larger than the diameter of the other end are formed, but the diameter of the one end may be the same as the diameter of the other end. Such a semiconductor core can be easily formed by reducing the volume of the island-shaped catalyst metal portion formed in the growth hole 2016 so that the cross-sectional shape of the catalyst metal portion becomes almost semicircle.

In the thirty-sixth and thirty-seventh embodiments, the quantum well layers 2012A and 2022A made of p-type InGaN and p are formed while the island-shaped catalyst metal portions 2018 and 2028 are held at one end of the semiconductor cores 2011A and 2021A. Although the semiconductor layers 2013A and 2023A made of type GaN are formed, only the semiconductor layers may be formed. In other words, the quantum well layers 2012A and 2022A may not be formed.

In the 36th and 37th embodiments, the outer circumferential surfaces of the conductive films 2015 and 2025 are formed to be continuous with the outer circumferential surfaces of the insulators 2014 and 2024 without generating a step, but the conductive films 2015 and 25 are not formed. Thus, the outer circumferential surface of the semiconductor layer may be formed so as to be continuous with the outer circumferential surfaces of the insulators 2014 and 2024 without generating a step.

In the thirty-sixth and thirty-seventh embodiments, the semiconductor cores 2011A and 2021A, the quantum well layers 2012A and 2022A, and the semiconductor layers 2013A and 2023A are formed using the catalyst metal portions 2018 and 2028, respectively. The semiconductor core, the quantum well layer, and the semiconductor layer may be formed without using the portions 2018 and 2028.

In the case where the semiconductor core, the quantum well layer and the semiconductor layer are formed without using the catalytic metal parts 2018 and 28, the axial well of the quantum well layer and the semiconductor layer covers the axial end surface of one end side of the semiconductor core. The thickness becomes almost equal to the thickness in the radial direction of the portion covering the outer circumferential surface of the semiconductor core. For this reason, in the insulator etching process, the axial end surface of the one end side of the semiconductor core is easily exposed, but the axial end surface of the one end side of the semiconductor core may be exposed.

In the separation process of the said 36th, 37th embodiment, you may mechanically isolate the semiconductor core 2011 from the board | substrate 2101 using a cutting tool. This cutting tool is used to cause a source close to the substrate 2101 side of the semiconductor core 2011 to be installed on the substrate 2101 to be bent, and to stress the semiconductor core 2011 covered with the semiconductor layer 2013. As a result, the semiconductor core 2011 covered with the semiconductor layer 2013 is separated from the substrate 2101. In this case, a plurality of fine rod-shaped structure light emitting elements provided on the substrate 2101 can be separated in a short time by a simple method.

In the insulator etching processes of the thirty-sixth and thirty-seventth embodiments, the conductive film 2015A is etched by etching the mask layer 2014B so that a part of the mask layers 2014B and 2024B remain around the end of the other end side of the semiconductor core 2011. 2025A), semiconductor layers 2013A and 2023A, and quantum well layers 2012A and 2022A may be lifted off at the same time.

In the 36th and 37th embodiments, other crystal growth apparatuses such as MBE (molecular beam epitaxial) apparatus may be used instead of the MOCVD apparatus.

[38th Embodiment]

Next, the backlight, the illumination device, and the display device provided with the rod-shaped structure light emitting device according to the 38th embodiment of the present invention will be described. In the thirty-eighth embodiment, the rod-shaped structure light emitting device according to any one of the first to thirty-seventh embodiments or a modification thereof is arranged on an insulating substrate. The arrangement of the rod-shaped structure light emitting device is described in Japanese Patent Application No. 2007-102848 (Japanese Unexamined Patent Application Publication No. 2008-260073), and includes a substrate, an integrated circuit device, and an arrangement method of a fine structure. Display element ”.

FIG. 99 is a plan view of an insulating substrate used in the backlight, the lighting device, and the display device of the 38th embodiment of the present invention. As shown in FIG. 99, metal electrodes 2351 and 2352 are formed on the surface of the insulating substrate 2350. The insulating substrate 2350 is a substrate having an insulating surface by forming a silicon oxide film on an insulator such as glass, ceramic, aluminum oxide, resin, or a semiconductor surface such as silicon. When using a glass substrate, it is preferable to form the base insulating film, such as a silicon oxide film and a silicon nitride film, on the surface.

The metal electrodes 2351 and 2352 are formed in a desired electrode shape using a printing technique. Further, the metal film and the photoconductor film may be laminated uniformly, and the desired electrode pattern may be exposed and etched to form.

Although omitted in FIG. 99, pads are formed in the metal electrodes 2351 and 2352 so that a potential is applied from the outside. The rod-shaped structure light emitting element is arranged in a portion (array region) in which the metal electrodes 2351 and 2352 oppose each other. In FIG. 99, although 2 x 2 array area | regions which arrange | position a rod-shaped structure light emitting element are arrange | positioned, you may arrange | position arbitrary numbers.

It is a schematic cross section seen from the 100-100 line of FIG.

First, as shown in FIG. 100, the isopropyl alcohol (IPA) 361 containing the rod-shaped structure light emitting element 2360 is apply | coated thinly on the insulating substrate 2350. FIG. In addition to IPA 361, ethylene glycol, propylene glycol, methanol, ethanol, acetone, or a mixture thereof may be used. Alternatively, the IPA 361 may use a liquid, water, or the like composed of other organic materials. In addition, the rod-shaped structure light emitting element 2360 is the rod-shaped structure light emitting element according to any one of the first to thirty-seventh embodiments, or a modification thereof.

However, if a large current flows between the metal electrodes 2351 and 2352 through the liquid, the desired voltage difference cannot be applied between the metal electrodes 2351 and 2352. In such a case, an insulating film of about 10 nm to 30 nm may be coated on the entire surface of the insulating substrate 2350 so as to cover the metal electrodes 2351 and 2352.

The thickness of applying the IPA 361 including the rod-shaped light emitting device 2360 is a liquid so that the rod-shaped light emitting device 2360 may be arranged in the next process of arranging the rod-shaped light emitting device 2360. Among them, the rod-shaped structure light emitting device 2360 can move. Therefore, the thickness which apply | coats IPA 361 is more than the thickness of the rod-shaped structure light emitting element 2360, and is several micrometers-several mm, for example. If the thickness to be applied is too thin, the rod-shaped structure light emitting device 2360 is difficult to move, and if too thick, the time for drying the liquid becomes long. The amount of the rod-shaped structure light emitting element 2360 is preferably 1 × 10 ⁴ / cm 3 to 1 × 10 ⁷ / cm 3 with respect to the amount of IPA.

In order to apply the IPA 361 including the rod-shaped light emitting element 2360, a frame is formed around the outer circumference of the metal electrode on which the rod-shaped light emitting element 2360 is arranged, and the rod-shaped light emitting element is formed in the frame. IPA 361 including 2360 may be filled to a desired thickness. However, when the IPA 361 including the rod-shaped structure light emitting device 2360 has a viscosity, it can be applied to a desired thickness without requiring a frame.

 IPA, ethylene glycol, propylene glycol,… Or a mixture thereof, or a liquid composed of other organic substances, or a liquid such as water, the lower the viscosity is preferable for the arrangement process of the rod-shaped structure light emitting element 2360, and the one more likely to be evaporated by heating is preferable. .

Subsequently, a potential difference is provided between the metal electrodes 2351 and 2352. In this thirty-eighth embodiment, a potential difference of 1 V was appropriate. Although the potential difference between the metal electrodes 2351 and 2352 can be applied to 0.1 to 10 V, the arrangement of the rod-shaped structure light emitting elements 2360 becomes worse at 0.1 V or less, and insulation between the metal electrodes starts to become a problem at 10 V or more. Therefore, 1-5V is preferable and it is preferable to set it as about 1V further.

FIG. 101 illustrates a principle of arranging the rod-shaped structure light emitting device 2360 on the metal electrodes 2351 and 2352. As shown in FIG. 101, when the potential V _L is applied to the metal electrode 2351 and the potential V _R (V _L <V _R ) is applied to the metal electrode 2352, the metal electrode 2351 is negatively charged. Is induced and an electrostatic charge is induced at the metal electrode 2352. When the rod-shaped light emitting element 2360 approaches, electrostatic charges are induced on the side of the rod-shaped light emitting element 2360 close to the metal electrode 2351, and negative charges are induced on the side close to the metal electrode 2352. do. The charge is induced in the rod-shaped structure light emitting device 2360 by electrostatic induction. That is, the rod-shaped structure light emitting device 2360 placed in the electric field is caused by charge being induced on the surface until the internal electric field becomes zero. As a result, attractive force is applied between each electrode and the rod-shaped structure light emitting element 2360 by electrostatic force, and the rod-shaped structure light emitting element 2360 follows the electric line of force generated between the metal electrodes 2351 and 2352. In addition, since the charges induced in the rod-shaped light emitting elements 2360 are substantially the same, they are regularly arranged in a constant direction at substantially equal intervals due to the repulsive force caused by the charges. However, for example, in the rod-shaped structure light emitting element 2001 shown in FIG. 95 of the 36th embodiment, the direction of the axial end surface 2011a is not constant but becomes random (rod-shaped structure light emitting element of another embodiment or modification). The same is true for).

As described above, the rod-shaped structure light emitting device 2360 generates electric charges in the rod-shaped structure light emitting device 2360 by an external electric field generated between the metal electrodes 2351 and 2352, and the metal electrode ( Since the rod-shaped structured light emitting device 2360 is adsorbed to the 2351 and 2352, the rod-shaped structured light emitting device 2360 needs to be a size movable in the liquid. Therefore, the size of the rod-shaped structure light emitting element 2360 is changed by the amount of coating (thickness) of the liquid. If the amount of liquid is applied, the rod-shaped structure light emitting device 2360 should be of nano order size. However, if the amount of liquid is applied, it may be of micro order size.

When the rod-shaped structure light emitting device 2360 is electrically neutral but positively or negatively charged, the rod-shaped structure light emitting device 2360 may have a rod shape by only providing a static potential difference DC between the metal electrodes 2351 and 2352. The structural light emitting elements 2360 cannot be arranged stably. For example, when the rod-shaped structure light emitting element 2360 is properly charged positively as a net, the attraction force with the metal electrode 2352 in which the electrostatic charge is induced becomes relatively weak. Therefore, the arrangement of the rod-shaped structure light emitting elements 2360 becomes a non-object.

In such a case, as shown in FIG. 102, it is preferable to apply an AC voltage between the metal electrodes 2351 and 2352. In FIG. 102, a reference potential is applied to the metal electrode 2352, and an AC voltage having an amplitude (V _PPL / 2) is applied to the metal electrode 2351. As a result, even when the rod-shaped structure light emitting device 2360 is charged, the array can be held as an object. In this case, the frequency of the alternating voltage applied to the metal electrode 2352 is preferably 10 Hz to 1 MHz, most preferably 50 Hz to 1 Hz, and more preferably the arrangement is stable. The AC voltage applied between the metal electrodes 2351 and 2352 is not limited to the sine wave, but may be periodically varied, such as square waves, triangle waves, and sawtooth waves. In addition, it was preferable to set V _{PPL to} about 1V.

Subsequently, after arranging the rod-shaped structure light emitting elements 2360 on the metal electrodes 2351 and 2352, the insulating substrate 2350 is heated to evaporate and dry the liquid, and the rod-shaped structure light emitting elements 2360 are made of metal. It is fixed by being arranged at equal intervals along the electric line of force between the electrodes (2351, 2352).

103 is a plan view of an insulating substrate 2350 in which the rod-shaped structure light emitting elements 2360 are arranged. By using the insulating substrate 2350 on which the rod-shaped structure light emitting elements 2360 are arranged for a backlight such as a liquid crystal display device, the backlight can be made thinner and lighter, and the light emitting efficiency is high and power saving can be realized. In addition, by using the insulating substrate 2350 in which the rod-shaped structure light emitting elements 2360 are arranged as a lighting device, the lighting device can be made thinner and lighter, and the light emitting efficiency is high and power saving can be realized.

104 is a plan view of a display device using an insulating substrate on which the rod-shaped structure light emitting elements 2360 are arranged. As shown in FIG. 104, the display device 2300 includes a display portion 2301, a logic circuit portion 2302, a logic circuit portion 2303, a logic circuit portion 2304, and a logic circuit portion 2305 on the insulating substrate 2310. It becomes the structure to say. In the display portion 2301, a rod-shaped structure light emitting element 2360 is arranged in pixels arranged in a matrix.

FIG. 105 shows a circuit diagram of the main portion of the display portion 2301 of the display device 2300, and as shown in FIG. 105, the display portion 2301 of the display device 2300 crosses a plurality of scan signal lines ( GL (only one is shown in FIG. 105) and a plurality of data signal lines SL (only one is shown in FIG. 105), and two adjacent scanning signal lines GL and two adjacent data signal lines ( Pixels are arranged in a matrix at the portion surrounded by SL). This pixel includes a switching element Q1 having a gate connected to the scan signal line GL and a source connected to the data signal line SL, a switching element Q2 having a gate connected to the drain of the switching element Q1, A pixel capacitor C having one end connected to the gate of the switching element Q2, and a plurality of light emitting diodes D1 to Dn (rod-shaped light emitting element 2360) driven by the switching element Q2. Have

The polarities of pn of the rod-shaped structure light emitting device 2360 are not aligned to one side but are randomly arranged. For this reason, at the time of driving, it is driven by an alternating voltage, and the rod-shaped structure light emitting elements 2360 having different polarities alternately emit light.

In addition, according to the method for manufacturing the display device, an insulating substrate 2350 having an array region in which two electrodes 2351 and 2352 are provided with independent potentials, respectively, is formed, and on the insulating substrate 2350. The liquid including the rod-shaped structure light emitting device 2360 of nano order size or micro order size is coated. Thereafter, independent voltages are applied to the two electrodes 2351 and 2352 to arrange the fine rod-shaped structure light emitting elements 2360 at positions defined by the two electrodes 2351 and 2352. Thereby, the rod-shaped structure light emitting device 2360 can be easily arranged on the predetermined insulating substrate 2350.

In addition, in the method of manufacturing the display device, the amount of semiconductors used can be reduced, and the display device can be manufactured thinner and lighter. In addition, the rod-shaped structure light emitting device 2360 can emit light from the entire circumference of the semiconductor core covered with the semiconductor layer, thereby widening the light emitting area, thereby realizing a display device having high luminous efficiency and power saving.

In the thirty-eighth embodiment, although the potential difference is applied to the two metal electrodes 2351 and 2352 formed on the surface of the insulating substrate 2350, the rod-shaped structure light emitting device 2360 is arranged between the metal electrodes 2351 and 2352. It is not limited to this, You may form a 3rd electrode between two electrodes formed in the surface of an insulated substrate, apply an independent voltage to each of 3 electrodes, and arrange | position a rod-shaped structure light emitting element at the position prescribed | regulated by an electrode.

In the thirty-eighth embodiment, the display device including the rod-shaped structure light emitting element has been described, but the present invention is not limited thereto, and the rod-shaped structure light emitting element manufactured by the method for manufacturing the rod-shaped structure light emitting element of the present invention may be a backlight or the like. You may apply to other apparatuses, such as a lighting apparatus.

[39th Embodiment]

106 is a perspective view of a light emitting device of a 39th embodiment of the present invention. As shown in FIG. 106, the light-emitting device of this 39th Embodiment is rod-shaped mounted on the insulating board 316 and the insulating board 316 so that the longitudinal direction may be parallel to the mounting surface of the insulating board 316. FIG. The structure light emitting element 310 is provided. The rod-shaped structure light emitting device 310 includes a semiconductor core 311 formed of a rod-shaped n-type GaN having a substantially hexagonal cross section, and a semiconductor layer 312 formed of a p-type GaN formed to cover a portion of the semiconductor core 311. Has The semiconductor core 311 is formed with an exposed portion 311a through which an outer circumferential surface of one end thereof is exposed. The end surface of the other end side of the semiconductor core 311 is covered with the semiconductor layer 312.

The rod-shaped structured light emitting device 310 mounted on the insulating substrate 316 may have an outer circumferential surface of the semiconductor layer 312 so that the rod-shaped structured light emitting device 310 may have a longitudinal direction parallel to the mounting surface of the insulating substrate 316. Since the mounting surface of the insulating substrate 316 is in contact with each other, heat generated in the rod-shaped structure light emitting device 310 can be efficiently radiated from the semiconductor layer 312 to the insulating substrate 316. Therefore, even if plural arrangements are made, it is difficult to be absorbed by the adjacent rod-shaped light emitting elements, and a light emitting device having high light extraction efficiency and good heat dissipation can be realized as compared with the conventionally installed prior art. In the light emitting device, since the rod-shaped structure light emitting device 310 is laid on the insulating substrate 316 to the side, the thickness including the insulating substrate 316 can be reduced.

The rod-shaped structure light emitting device 310 is manufactured as follows.

First, a mask having growth holes is formed on a substrate made of n-type GaN. As the mask, a material capable of selectively etching the semiconductor core 311 and the semiconductor layer 312, such as silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ), is used. Formation of a growth hole can use the well-known lithography method and the dry etching method used for a normal semiconductor process.

Subsequently, n-type GaN is crystal-grown on a substrate exposed by a growth hole of a mask using a MOCVD (Metal 0rganic Chemical Vapor Deposition) device to form a rod-shaped semiconductor core 311. The temperature of the MOCVD apparatus is set to about 950 ° C., trimethylgallium (TMG) and ammonia (NH ₃ ) are used as growth gases, silane (SiH ₃ ) is used for n-type impurity supply, and hydrogen (H ₂ ) is used as a carrier gas. ), An n-type GaN semiconductor core containing Si as an impurity can be grown. In this case, the diameter of the growing semiconductor core 311 may be determined by the diameter of the growth hole of the mask. The grown n-type GaN becomes hexagonal crystal growth, and a hexagonal pillar-shaped semiconductor core is obtained by growing with the c-axis direction perpendicular to the substrate surface.

Subsequently, a semiconductor layer made of p-type GaN is formed on the entire surface of the substrate so as to cover the rod-shaped semiconductor core 311. The temperature of the MOCVD apparatus was set to about 960 ° C, and trimethylgallium (TMG) and ammonia (NH ₃ ) were used as the growth gases, and biscyclopentadienyl magnesium (Cp ₂ Mg) was used to supply p-type impurities. P-type GaN can be grown as an impurity.

Subsequently, a region except for the portion of the semiconductor layer covering the semiconductor core and the mask are removed by lift-off, thereby exposing the substrate-side outer peripheral surface of the rod-shaped semiconductor core 311 to form the exposed portion 311a. In this state, the end surface of the side opposite to the substrate of the semiconductor core 311 is covered by the semiconductor layer 312. When the mask is made of silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ), using a solution containing hydrofluoric acid (HF) does not easily affect the semiconductor core and the portion of the semiconductor layer covering the semiconductor core. The mask can be etched without removal, and the region except for the portion of the semiconductor layer covering the semiconductor core on the mask with the mask can be removed by lift off. In this embodiment, the length of the exposed portion 311a of the semiconductor core 311 is determined by the film thickness of the removed mask. Although the lift-off was used in the exposure process of this embodiment, you may expose a part of semiconductor core by etching.

Subsequently, the source close to the substrate side of the semiconductor core 311, which is erected on the substrate by immersing the substrate in an isopropyl alcohol (IPA) aqueous solution and vibrating the substrate along the substrate plane using ultrasonic waves (for example, several tens of microseconds), is bent. Stress is applied to the semiconductor core 311 covered by the semiconductor layer 312 so that the semiconductor core 311 covered by the semiconductor layer 312 is separated from the substrate.

In this way, a fine rod-shaped structure light emitting element separated from the substrate made of n-type GaN can be manufactured. Since the rod-shaped structure light emitting device separated from the substrate made of n-type GaN is obtained in a dispersed state in the IPA aqueous solution, the dispersion is applied to the mounting surface of the insulating substrate 316 and dried to the mounting surface of the insulating substrate 316. Can be arranged to be parallel.

In the rod-shaped light emitting device, the semiconductor layer 312 crystal grows outward from the outer circumferential surface of the semiconductor core 311 in the radial direction outward, the growth distance in the radial direction is short, and the defect is avoided outward so that the semiconductor has fewer crystal defects. The semiconductor core 311 may be covered by the layer 312. Therefore, a rod-shaped structure light emitting device having good characteristics can be realized.

According to the rod-shaped structure light emitting device having the above structure, the semiconductor layer 312 made of p-type GaN so as to cover the semiconductor core 311 made of the rod-shaped n-type GaN and to expose the outer peripheral surface of a part of the semiconductor core 311. By forming the semiconductor layer 312, the exposed portion 311a of the semiconductor core 311 is connected to the n-side electrode and covers the semiconductor core 311, even in the case of a micro rod size or a nano rod-shaped fine rod-shaped structure light emitting device. The p-side electrode can be connected to the portion of. In the rod-shaped structure light emitting device, the n-side electrode is connected to the exposed portion 311a of the semiconductor core 311 and the p-side electrode is connected to the semiconductor layer 312 so that the outer peripheral surface and the semiconductor layer 312 of the semiconductor core 311 are connected. Light is emitted from the pn junction by flowing a current from the p-side electrode to the n-side electrode so that recombination of electrons and holes occurs at the pn junction of the inner circumferential surface of. In this rod-shaped light emitting device, light is emitted from the entire circumference of the semiconductor core 311 covered with the semiconductor layer 312, so that the light emitting area is widened, so that the light emitting efficiency is high. Therefore, a fine rod-shaped light emitting device having a high luminous efficiency that can be easily connected to electrodes with a simple configuration can be realized. In addition, since the rod-shaped structure light emitting device is not integral with the substrate, the degree of freedom in mounting to the device is high.

Here, the fine rod-shaped light emitting device is, for example, a micro order size having a diameter of 1 µm and a length of 20 µm, or a nano order size having at least a diameter of less than 1 µm in diameter or length. In addition, the rod-shaped structure light emitting device can reduce the amount of semiconductor used, and can realize a backlight, an illumination device, a display device, and the like, which can reduce the thickness and weight of the device using the light emitting device.

In addition, since the outer circumferential surface of the region covered by the semiconductor layer 312 of the semiconductor core 311 and the outer circumferential surface of the exposed region of the semiconductor core 311 are continuous, the exposed region of the semiconductor core 311 becomes the semiconductor layer 312. Since the taper is thinner than the outer diameter of the wafer, it is easy to bend at the substrate side of the exposed region of the semiconductor core 311 formed so as to stand on the substrate in the manufacturing process, thereby facilitating manufacture.

In addition, since the outer peripheral surface of one end side of the semiconductor core 311 is exposed to, for example, about 5 μm, the semiconductor core 311 can be easily used by using a known semiconductor process having ordinary processing accuracy such as a lift-off method or a nanoimprint method. It is possible to connect one electrode (wiring) to the exposed part 311a of the outer peripheral surface of one end side of the () side, and to connect the electrode (wiring) to the semiconductor layer 312 on the other end side of the semiconductor core 311, and both ends The electrodes can be separated and connected to each other, and the short circuit between the electrodes connected to the semiconductor layer 312 and the exposed portions of the semiconductor core 311 can be easily prevented.

In addition, the portion of the semiconductor layer 312 covering the end surface of the side opposite to the exposed portion 311a of the semiconductor core 311 by covering the end surface of the other end side of the semiconductor core 311 with the semiconductor layer 312. The electrode can be easily connected to the semiconductor core 311 without being short-circuited. As a result, the electrodes can be easily connected to both ends of the fine rod-shaped light emitting device.

In addition, since the outer circumferential surface of the region covered by the semiconductor layer 312 of the semiconductor core 311 and the outer circumferential surface of the exposed region of the semiconductor core 311 are continuous, the exposed region of the semiconductor core 311 becomes the semiconductor layer 312. Since the taper is thinner than the outer diameter of the wafer, it is easy to bend at the substrate side of the exposed region of the semiconductor core 311 formed so as to stand on the substrate in the manufacturing process, thereby facilitating manufacture.

[40th Embodiment]

107 has shown the perspective view of the light-emitting device of 40th Embodiment of this invention. As shown in FIG. 107, the light-emitting device of this 40th Embodiment is rod-shaped mounted on the insulating board 326 and the insulating board 326 so that the longitudinal direction may be parallel to the mounting surface of the insulating board 326. As shown in FIG. The structure light emitting element 320 is provided. The rod-shaped structure light emitting device 320 is a quantum well layer including a semiconductor core 321 made of rod-shaped n-type GaN having a substantially hexagonal cross section, and a p-type InGaN formed to cover a portion of the semiconductor core 321. 322 and a semiconductor layer 323 made of p-type GaN formed to cover the quantum well layer 322. The semiconductor core 321 is formed with an exposed portion 321a through which an outer circumferential surface of one end thereof is exposed. The end surface of the other end side of the semiconductor core 321 is covered with the quantum well layer 322 and the semiconductor layer 323.

In the light-emitting device of the forty-fifth embodiment, like the rod-shaped structure light-emitting device of the light-emitting device of the thirty-ninth embodiment, a rod-shaped semiconductor core is formed by growing n-type GaN on a substrate made of n-type GaN using a MOCVD device. 321 is formed.

The light emitting device of the forty embodiment has the same effect as the light emitting device of the forty ninth embodiment.

In addition, by forming the quantum well layer 322 between the semiconductor core 321 and the semiconductor layer 323, the light emission efficiency may be further improved by the quantum confinement effect of the quantum well layer 322. After growing the semiconductor core 321 of n-type GaN as described above in the MOCVD apparatus, the set temperature is changed from 600 ° C. to 800 ° C. according to the emission wavelength, nitrogen (N ₂ ) in the carrier gas and TMG in the growth gas. And InGaN quantum well layer 322 on n-type GaN semiconductor core 321 by supplying NH ₃ , trimethylindium (TMI). Then, also the temperature of a 960 ℃ and, as described above, the semiconductor layer 323 made of p-type GaN by using Cp ₂ Mg in for using TMG and NH _3, and the p-type impurity provided as a growth gas set Can be formed. The quantum well layer may have a p-type AlGaN layer as an electron block layer between the InGaN layer and the p-type GaN layer, or may have a multi-quantum well structure in which a GaN barrier layer and an InGaN quantum well layer are laminated. .

[41th Embodiment]

108 is a perspective view of a light emitting device of a forty-first embodiment of the present invention. As shown in FIG. 108, the light emitting device of the forty-first embodiment is a rod-shaped package in which the longitudinal direction is parallel to the mounting surface of the insulating substrate 336 on the insulating substrate 336 and the insulating substrate 336. The structure light emitting element 330 is provided. The rod-shaped structure light emitting device 330 includes a semiconductor core 331 made of rod-shaped n-type GaN having a substantially hexagonal cross section and a p-type GaN formed to cover a portion of the semiconductor core 331. ) And a transparent electrode 333 formed to cover the semiconductor layer 332. The semiconductor core 331 has an exposed portion 331a through which an outer circumferential surface of one end thereof is exposed. The end surface of the other end side of the semiconductor core 331 is covered with the semiconductor layer 332 and the transparent electrode 333. The transparent electrode 333 is formed of ITO (tin-added indium oxide) having a thickness of 200 nm. After the MOCVD apparatus is formed up to the semiconductor layer 332 made of p-type GaN, ITO is formed so as to cover the semiconductor layer 332 by moving from the MOCVD apparatus to the deposition apparatus or the sputtering apparatus for each substrate made of n-type GaN. After the formation of the ITO film, the heat treatment is performed at 500 ° C to 600 ° C to reduce the resistance between the semiconductor layer 332 made of p-type GaN and the transparent electrode 333 made of ITO. In addition, a transparent electrode is not limited to this, For example, the laminated metal film of Ag / Ni of thickness 5nm, etc. may be used. The deposition method or the sputtering method can be used for film formation of the Ag / Ni laminated metal film. In order to lower the resistance of the electrode layer, after forming 1TO, a laminated metal film of Ag / Ni may be laminated.

By connecting an electrode (or wiring) to the end of the transparent electrode 334 opposite to the exposed portion 331a of the semiconductor core 331, the short circuit between the electrode and the semiconductor core 331 can be easily prevented. In addition, since the electrode (or wiring) connected to the transparent electrode 334 can be thickened, heat can be efficiently radiated through the electrode (or wiring).

In addition, the rod-shaped structure light emitting device 330 connects an n-side electrode (not shown) to the exposed portion 331a of the semiconductor core 331, and a p-side electrode (not shown) to the transparent electrode 334 on the other end side. Is connected. Since the p-side electrode is connected to the end of the transparent electrode 334, the area for blocking the light emitting region with the electrode can be minimized, and the light extraction efficiency can be improved.

In the rod-shaped structure light emitting element of the forty-first embodiment, like the rod-shaped structure light emitting element of the light-emitting device of the forty-ninth embodiment, by using a MOCVD apparatus, n-type GaN is crystal-grown on a substrate made of n-type GaN and rod-shaped; The semiconductor core 331 is formed.

The light emitting device of the forty-first embodiment has the same effect as the light emitting device of the forty-ninth embodiment.

In addition, the transparent electrode 333 is formed to cover the semiconductor layer 332 so that the semiconductor layer 332 is connected to the electrode through the transparent electrode 333 so that the current is not concentrated and biased in the electrode connection portion. A wide current path can be formed to make the entire device emit light, further improving luminous efficiency. In particular, in the configuration of the semiconductor core composed of the n-type semiconductor and the semiconductor layer composed of the p-type semiconductor, the semiconductor layer composed of the p-type semiconductor is difficult to increase the impurity concentration and the resistance is large, so that current is easily concentrated in the electrode connection portion. As a result, a wide current path can be formed to emit the entire element, thereby further improving the luminous efficiency.

[42th Embodiment]

109 has shown the perspective view of the light-emitting device of 42nd Embodiment of this invention. As shown in FIG. 109, the light-emitting device of this 42nd Embodiment is rod-shaped mounted on the insulating board 346 and the insulating board 346 so that the longitudinal direction may become parallel to the mounting surface of the insulating board 346. The structure light emitting element 340 is provided. The rod-shaped structure light emitting device 340 includes a semiconductor core 341 made of a rod-shaped n-type GaN having a substantially hexagonal cross section, and a quantum well layer made of a p-type InGaN formed to cover a portion of the semiconductor core 341 ( 342, a semiconductor layer 343 made of p-type GaN formed to cover the quantum well layer 342, and a transparent electrode 344 formed to cover the semiconductor layer 343. The semiconductor core 341 is formed with an exposed portion 341a through which an outer circumferential surface of one end thereof is exposed. The end surface of the other end side of the semiconductor core 341 is covered with the quantum well layer 342, the semiconductor layer 343, and the transparent electrode 344. The transparent electrode 343 is formed of ITO (tin-added indium oxide). In addition, a transparent electrode is not limited to this, For example, the laminated metal film of Ag / Ni of thickness 5nm, etc. may be used.

By connecting an electrode (or wiring) to the end of the transparent electrode 344 opposite to the exposed portion 341a of the semiconductor core 341, the electrode can be easily prevented from shorting with the semiconductor core 341 side. In addition, since the electrode (or wiring) connected to the transparent electrode 344 can be made thicker or larger in cross-sectional area, heat can be efficiently dissipated through the electrode (or wiring).

In addition, the rod-shaped structure light emitting device 340 connects an n-side electrode (not shown) to the exposed portion 341a of the semiconductor core 341, and a p-side electrode (not shown) to the transparent electrode 344 on the other end side. Is connected. Since the p-side electrode is connected to the end of the transparent electrode, the area for blocking the light emitting region with the electrode can be minimized, and the light extraction efficiency can be improved.

In the rod-shaped structure light emitting device of the forty-second embodiment, like the rod-shaped structure light emitting device of the light-emitting device of the forty-ninth embodiment, the rod-shaped GaN crystal is grown on a substrate made of n-type GaN by using a MOCVD apparatus. The semiconductor core 321 is formed.

The light emitting device of the forty-second embodiment has the same effect as the light emitting device of the forty-fourth embodiment.

In addition, by forming the transparent electrode 344 to cover the semiconductor layer 343, the semiconductor layer 343 is connected to the p-side electrode through the transparent electrode 344 so that the current is concentrated and concentrated in the electrode connection portion. Without this, a wide current path can be formed to make the entire device emit light, further improving luminous efficiency. In particular, in the configuration of the semiconductor core composed of the n-type semiconductor and the semiconductor layer composed of the p-type semiconductor, the semiconductor layer composed of the p-type semiconductor is difficult to increase the impurity concentration and the resistance is large, so that current is easily concentrated in the electrode connection portion. As a result, a wide current path can be formed to emit the entire element, thereby further improving the luminous efficiency.

[43th Embodiment]

110 is a side view of the light-emitting device of the 43rd embodiment of the present invention. As shown in FIG. 110, the light-emitting device of the forty-third embodiment is a rod-shaped package in which the longitudinal direction is parallel to the mounting surface of the insulating substrate 356 on the insulating substrate 356 and the insulating substrate 356. The structure light emitting element 350 is provided. The rod-shaped structure light emitting device 350 includes a semiconductor core 351 made of rod-shaped n-type GaN having a substantially hexagonal cross section and a p-type GaN formed to cover a portion of the semiconductor core 351. ) And a transparent electrode 353 formed to cover the semiconductor layer 352. The semiconductor core 351 has an exposed portion 351a through which an outer circumferential surface of one end side thereof is exposed. A metal layer 354 made of A1 is formed on the transparent electrode 353 and on the insulating substrate 356 side. The metal layer 354 covers approximately half of the lower side of the outer circumferential surface of the transparent electrode 353. The end surface of the other end side of the semiconductor core 351 is covered with the semiconductor layer 352 and the transparent electrode 353. The transparent electrode 353 is formed of ITO. In addition, a transparent electrode is not limited to this, For example, the laminated metal film of Ag / Ni of thickness 5nm, etc. may be used. The metal layer 354 is not limited to Al, and Cu, W, Ag, Au, or the like may be used. In the rod-shaped structure light emitting device of the forty-third embodiment, like the rod-shaped structure light emitting device of the light-emitting device of the forty-fifth embodiment, the rod-shaped GaN crystal is grown on a substrate made of n-type GaN using a MOCVD apparatus. Forming a semiconductor core 351 on the semiconductor substrate, forming a semiconductor layer 352 made of p-type GaN in the MOCVD apparatus, and then moving to a vapor deposition apparatus to cover the semiconductor layer 352; ). After heat-processing at 500 degreeC-600 degreeC after film-forming of an ITO film | membrane, it moves to a vapor deposition apparatus and forms Al into a film so that the transparent electrode 353 may be covered. Next, similarly to the thirty-ninth embodiment, the semiconductor layer, the transparent electrode, the Al layer, and the mask covering the semiconductor core are removed by lift-off, and a portion of the semiconductor core 351 is exposed, and then ultrasonic waves are used. Thus, the rod-shaped structure light emitting device is separated from the substrate made of n-type GaN. And the longitudinal direction of the rod-shaped structure light emitting element is arranged in parallel on the mounting surface of the insulating substrate 356. In addition, approximately half of the lower side of the outer peripheral surface of the transparent electrode 353 is etched back by etching back a portion of the metal layer made of Al that is not on the insulating substrate 356 side by anisotropic dry etching. A covering metal layer 354 may be formed. The etch back of the metal layer which consists of Al can use the well-known Al dry etching method used for a semiconductor process.

The light emitting device of the forty-third embodiment has the same effects as the light emitting device of the forty-first embodiment.

The light emitted from the rod-shaped structure light emitting device 350 toward the insulating substrate 356 by the metal layer 354 formed on the insulating substrate 356 and on the transparent electrode 353 is reflected by the metal layer 354. Withdrawal efficiency is improved.

[44th Embodiment]

111 is a side view of the light emitting device of the forty-fourth embodiment of the present invention. As shown in FIG. 111, the light-emitting device of this 44th Embodiment is rod-shaped mounted on the insulating board 366 and the insulating board 366 so that the longitudinal direction may be parallel to the mounting surface of the insulating board 366. FIG. The structure light emitting element 360 is provided. The rod-shaped structure light emitting device 360 includes a semiconductor core 361 made of a rod-shaped n-type GaN having a substantially hexagonal cross section, and a quantum well layer made of a p-type InGaN formed to cover a portion of the semiconductor core 361 ( 362, a semiconductor layer 363 made of p-type GaN formed to cover the quantum well layer 362, and a transparent electrode 364 formed to cover the semiconductor layer 363. The semiconductor core 361 is formed with an exposed portion 361a exposing the outer peripheral surface of one end. A metal layer 365 made of Al is formed on the transparent electrode 364 and on the insulating substrate 366 side. The metal layer 365 covers approximately half of the lower side of the outer circumferential surface of the transparent electrode 364. The transparent electrode 364 is formed of ITO. In addition, a transparent electrode is not limited to this, For example, the laminated metal film of Ag / Ni of thickness 5nm, etc. may be used. In addition, the metal layer 365 is not limited to Al, Cu, W, Ag, Au or the like may be used.

112 shows a cross-sectional view of the light emitting device, and an end surface of the other end side of the semiconductor core 361 is covered with a quantum well layer 362, a semiconductor layer 363, and a transparent electrode 364.

The light emitting device of the forty-fourth embodiment has the same effect as the light emitting device of the forty-second embodiment.

The light emitted from the rod-shaped structure light emitting device 360 to the insulating substrate 366 by the metal layer 365 formed on the transparent electrode 364 and on the insulating substrate 366 is reflected by the metal layer 365. Withdrawal efficiency is improved.

In the 39th to 44th embodiments, n-type GaN doped with Si and p-type GaN doped with Mg are used, but impurities doped into GaN are not limited thereto. Ge may be used in the n-type, and Zn may be used in the p-type.

In addition, although the rod-shaped structure light emitting element which has the rod-shaped semiconductor core whose cross section is substantially hexagon was demonstrated in the said 39th-44th embodiment, it is not limited to this, The cross-section may be circular or elliptical rod shape, You may apply this invention to the rod-shaped structure light emitting element which has the rod-shaped semiconductor core whose cross section is another polygonal shape, such as a triangle. Although depending on growth conditions such as growth direction and growth temperature, when the diameter of the semiconductor core to be grown is small, about tens of nanometers to several hundreds of nanometers, the cross-section tends to be nearly circular in shape, and the diameter is about 0.5 μm. If the thickness is increased to several micrometers, the cross section may be easily grown in a hexagon.

For example, as shown in FIG. 113, the rod-shaped structure light emitting element 370 is formed so as to cover a part of the semiconductor core 371 made of a rod-shaped n-type GaN having a substantially circular cross section and a part of the semiconductor core 371. A semiconductor layer 372 made of type GaN and a transparent electrode 373 formed to cover the semiconductor layer 372 are provided. The semiconductor core 371 has an exposed portion 371a exposing an outer circumferential surface of one end thereof. A metal layer 374 made of Al is formed on the transparent electrode 373 and on the substrate 376 side. The end surface of the other end side of the semiconductor core 371 is covered with the semiconductor layer 372 and the transparent electrode 373.

As shown in FIG. 114, the rod-shaped structure light emitting element 380 is formed so as to cover a portion of the semiconductor core 381 made of a rod-shaped n-type GaN having a substantially circular cross section and a part of the semiconductor core 381. A quantum well layer 382 made of type InGaN, a semiconductor layer 383 made of p-type GaN formed to cover the quantum well layer 382, and a transparent electrode 384 formed to cover the semiconductor layer 383. Equipped with. The semiconductor core 381 is formed with an exposed portion 381a through which an outer circumferential surface of one end thereof is exposed. A metal layer 385 made of Al is formed on the transparent electrode 384 and on the substrate 386 side. The end surface on the other end side of the semiconductor core 381 is covered with the quantum well layer 382, the semiconductor layer 383, and the transparent electrode 384.

[45th Embodiment]

115 is a side view of the light emitting device of the 45th embodiment of the present invention, and 116 is a perspective view of the light emitting device. In this 45th embodiment, any one of the rod-shaped structure light emitting elements of the light emitting device of the first to 44th embodiments is used. In FIG. 116, the rod-shaped structure light emitting element of the same structure as the rod-shaped structure light emitting element of the light-emitting device of 40th Embodiment is shown.

115 and 116, the light emitting device of the forty-fifth embodiment has an insulating substrate 450 having metal electrodes 451 and 452 formed on the mounting surface thereof, and an insulating substrate having a longitudinal direction on the insulating substrate 450. The rod-shaped structure light emitting element 460 mounted so as to be parallel to the mounting surface of the 450 is provided.

As shown in FIG. 116, the rod-shaped structure light emitting element 460 is formed to cover a portion of the semiconductor core 471 and a semiconductor core 471 made of rod-shaped n-type GaN having a substantially hexagonal cross section. A quantum well layer 472 made of type InGaN and a semiconductor layer 473 made of p-type GaN formed to cover the quantum well layer 472. The semiconductor core 471 has an exposed portion 1371a exposing an outer circumferential surface of one end thereof. The end surface on the other end side of the semiconductor core 471 is covered with the quantum well layer 472 and the semiconductor layer 473.

115 and 116, the exposed portion 1371a on one end side of the rod-shaped structure light emitting element 460 is connected to the metal electrode 451, and the semiconductor layer on the other end side of the rod-shaped structure light emitting element 460. 473 is connected to the metal electrode 452. Here, the rod-shaped structure light emitting device 460 is insulated from the substrate 450 by bending a central portion due to a stiction generated when droplets of the gap between the surface of the substrate and the rod-shaped structure light emitting device are reduced by evaporation when the IPA aqueous solution is dried. ) Contact.

Next, the backlight, the lighting device, and the display device provided with the light emitting device in which the rod-shaped structure light emitting device 460 is arranged on the insulating substrate 450 will be described. The arrangement of the rod-shaped structure light emitting element 460 is described in Japanese Patent Application No. 2007-102848 (Japanese Patent Application Laid-Open No. 2008-260073), in which the arrangement of the microstructure and the substrate and the integrated structure Circuit device and display element ”.

117 is a plan view of an insulating substrate of a light emitting device used for the backlight, the lighting device, and the display device of the 45th embodiment. As illustrated in FIG. 117, metal electrodes 451 and 452 are formed on the surface of the insulating substrate 450. The insulating substrate 450 is a substrate having a silicon oxide film formed on an insulator such as glass, ceramic, aluminum oxide, resin, or a semiconductor surface such as silicon, and having an insulating surface. When using a glass substrate, it is preferable to form the base insulating film, such as a silicon oxide film and a silicon nitride film, on the surface.

The metal electrodes 451 and 452 are formed in a desired electrode shape by using a printing technique. Further, the metal film and the photoconductor film may be laminated uniformly, and the desired electrode pattern may be exposed and etched to form.

Although omitted in FIG. 117, pads are formed on the metal electrodes 451 and 452 so that a potential is applied from the outside. The rod-shaped structure light emitting elements are arranged in portions (array regions) in which the metal electrodes 451 and 452 face each other. In FIG. 117, although 2x2 array area | region which arranges rod-shaped structure light emitting element is arranged, you may arrange | position arbitrary number.

FIG. 118 is a schematic sectional view seen from the line 118-118 of FIG. 117.

First, as shown in FIG. 118, the isopropyl alcohol (IPA) 161 containing the rod-shaped structure light emitting element 460 is apply | coated thinly on the insulating board 450. FIG. In addition to the IPA 161, ethylene glycol, propylene glycol, methanol, ethanol, acetone, or a mixture thereof may be used. Alternatively, the IPA 161 may use a liquid, water, or the like composed of other organic materials.

However, if a large current flows between the metal electrodes 451 and 452 through the liquid, a desired voltage difference cannot be applied between the metal electrodes 451 and 452. In such a case, an insulating film of about 10 nm to 30 nm may be coated on the entire surface of the insulating substrate 450 so as to cover the metal electrodes 451 and 452.

The thickness of applying the IPA 161 including the rod-shaped structure light emitting element 460 is in the liquid so that the rod-shaped structure light emitting element 460 can be arranged in the next process of arranging the rod-shaped structure light emitting element 460. The rod-shaped structure light emitting device 460 can move. Therefore, the thickness which apply | coats IPA 161 is more than the thickness of the rod-shaped structure light emitting element 460, and is several micrometers-several mm, for example. If the thickness to be applied is too thin, the rod-shaped structure light emitting element 460 becomes difficult to move, and if it is too thick, the time for drying the liquid becomes long. The amount of the rod-shaped structure light emitting element 460 is preferably 1 × 10 ⁴ / cm 3 to 1 × 10 ⁷ / cm 3 with respect to the amount of IPA.

In order to apply the IPA 161 including the rod-shaped light emitting element 460, a frame is formed around the outer circumference of the metal electrode on which the rod-shaped light emitting element 460 is arranged, and the rod-shaped light emitting element ( The IPA 161 including 460 may be charged to a desired thickness. However, when the IPA 161 including the rod-shaped light emitting element 460 has a viscosity, it is possible to apply it to a desired thickness without requiring a frame.

IPA, ethylene glycol, propylene glycol,… Or a mixture thereof, or a liquid composed of other organic substances, or a liquid such as water, the lower the viscosity is preferable for the arrangement process of the rod-shaped structure light emitting element 460, and the one more easily evaporated by heating is preferable. .

Subsequently, a potential difference is provided between the metal electrodes 451 and 452. In the 43rd embodiment, it is appropriate to set the potential difference of 1V. Although the potential difference between the metal electrodes 451 and 452 can be applied at 0.1 to 10 V, the arrangement of the rod-shaped structure light emitting device 460 becomes worse at 0.1 V or less, and the insulation between the metal electrodes starts to become a problem at 10 V or more. Therefore, 1-5V is preferable and it is preferable to set it as about 1V further.

119 illustrates the principle of arranging the rod-shaped structure light emitting device 460 on the metal electrodes 451 and 452. As shown in FIG. 119, when the potential V _L is applied to the metal electrode 451 and the potential V _R (V _L <V _R ) is applied to the metal electrode 452, the metal electrode 451 is charged negatively. Is induced and electrostatic charge is induced at the metal electrode 452. When the rod-shaped light emitting element 460 approaches, electrostatic charges are induced on the side of the rod-shaped light emitting element 460 close to the metal electrode 451, and negative charges are induced on the side close to the metal electrode 452. do. The charge is induced in the rod-shaped structure light emitting element 460 by electrostatic induction. That is, the rod-shaped structure light emitting device 460 raised in the electric field is caused by charge being induced on the surface until the internal electric field becomes zero. As a result, an attractive force is applied between each electrode and the rod-shaped structure light emitting element 460 by the electrostatic force, and the rod-shaped structure light emitting element 460 follows the electric line of force generated between the metal electrodes 451 and 452, and Since the charges induced in the shape structure light emitting device 460 are almost the same, they are regularly arranged in a constant direction at substantially equal intervals due to the repulsive force caused by the charges. However, for example, in the rod-shaped structure light emitting device shown in FIG. 106 of the 39th embodiment, the direction of the exposed portion 311a side of the semiconductor core 311 covered with the semiconductor layer 312 is not constant but becomes random ( The same applies to the rod-shaped structure light emitting device of the other embodiment).

As described above, the rod-shaped structure light emitting element 460 generates charges to the rod-shaped structure light emitting element 460 by an external electric field generated between the metal electrodes 451 and 452, and the metal electrodes 451 and 452 are attracted by the attraction force. Since the rod-shaped structured light emitting element 460 is adsorbed onto it, the rod-shaped structured light emitting element 460 needs to be a size movable in the liquid. Therefore, the size of the rod-shaped structure light emitting element 460 is changed by the application amount (thickness) of the liquid. If the amount of liquid is applied, the rod-shaped structure light emitting device 460 should be of nano order size. However, if the amount of liquid is applied, it may be of micro order size.

When the rod-shaped structured light emitting device 460 is electrically neutral but positively or negatively charged, the rod-shaped structured light emitting device 460 may be formed by only providing a static potential difference (DC) between the metal electrodes 451 and 452. Can't arrange stably. For example, when the rod-shaped structure light emitting element 460 is positively charged as a net, the attraction force with the metal electrode 452 where the electrostatic charge is induced is relatively weak. Therefore, the arrangement of the rod-shaped structure light emitting element 460 becomes a non-object.

In such a case, as shown in FIG. 120, it is preferable to apply an AC voltage between the metal electrodes 451 and 452. In FIG. 120, a reference potential is applied to the metal electrode 451, and an AC voltage having an amplitude (V _PPL / 2) is applied to the metal electrode 452. As a result, even when the rod-shaped structure light emitting device 460 is charged, the array can be maintained as an object. In this case, the frequency of the alternating voltage applied to the metal electrode 452 is preferably 10 Hz to 1 MHz, and more preferably 50 Hz to 1 Hz, with the most stable arrangement. The AC voltage applied between the metal electrodes 451 and 452 is not limited to the sine wave, but may be periodically varied, such as square waves, triangle waves, and sawtooth waves. In addition, it was preferable to set V _{PPL to} about 1V.

Subsequently, after arranging the rod-shaped structure light emitting elements 460 on the metal electrodes 451 and 452, the liquid is evaporated and dried by heating the insulating substrate 450, and the rod-shaped structure light emitting elements 460 are made of the metal electrodes 451 and 452. Arrange them at equal intervals along the electric field lines between them.

According to the method of manufacturing the above light emitting device, an insulating substrate 450 having an array region formed of two electrodes 451 and 452 each having independent potentials is formed, and a nano order size or the like is formed on the insulating substrate 450. The liquid including the rod-shaped structure light emitting element 460 of the micro order size is coated. Thereafter, independent voltages are applied to the two electrodes 451 and 452 to arrange the fine rod-shaped structure light emitting elements 460 at positions defined by the two electrodes 451 and 452. Thereby, the rod-shaped structure light emitting element 460 can be easily arranged on the predetermined insulating substrate 450.

In addition, the method of manufacturing the light emitting device can reduce the amount of semiconductor used, and can manufacture a light emitting device that can be thinner and lighter. In addition, since the rod-shaped structure light emitting device 460 emits light from the entire circumference of the semiconductor core covered with the semiconductor layer, the light emitting region is widened, thereby realizing a light emitting device having high luminous efficiency and good power saving heat dissipation.

121 is a plan view of an insulating substrate 450 in which the rod-shaped structure light emitting elements 460 are arranged. By using the insulating substrate 450 on which the rod-shaped structure light emitting elements 460 are arranged for a backlight such as a liquid crystal display device, the backlight can be made thinner and lighter, and the backlight having high luminous efficiency and power saving heat dissipation can be realized. In addition, by using the insulating substrate 450 in which the rod-shaped structure light emitting elements 460 are arranged as a lighting device, it is possible to realize a lighting device that can be made thinner and lighter, and has high luminous efficiency and good power-saving heat dissipation.

122 shows a plan view of a display device having a light emitting device using an insulating substrate on which the rod-shaped structure light emitting elements 460 are arranged. As shown in FIG. 122, the display device 3300 includes a display portion 3301, a logic circuit portion 3302, a logic circuit portion 3303, a logic circuit portion 3304, and a logic circuit portion 3305 on the insulating substrate 3310. It becomes the structure to say. In the display portion 3301, a rod-shaped structure light emitting element 260 is arranged in pixels arranged in a matrix.

FIG. 123 shows a circuit diagram of the main portion of the display portion 3301 of the display device 3300. The display portion 3301 of the display device 3300 includes a plurality of scan signal lines (crossed over each other) as shown in FIG. GL (only one is shown in FIG. 123) and a plurality of data signal lines SL (only one is shown in FIG. 123), and two adjacent scanning signal lines GL and two adjacent data signal lines ( Pixels are arranged in a matrix at the portion surrounded by SL). This pixel includes a switching element Q1 having a gate connected to the scan signal line GL and a source connected to the data signal line SL, a switching element Q2 having a gate connected to the drain of the switching element Q1, The pixel capacitor C having one end connected to the gate of the switching element Q2, and the plurality of light emitting diodes D1 to Dn (rod-shaped light emitting element 460) driven by the switching element Q2. Have

The polarities of pn of the rod-shaped structure light emitting element 460 are not aligned to one side but are randomly arranged. For this reason, at the time of driving, it is driven by an alternating voltage, and the rod-shaped structure light emitting elements 460 of different polarities alternately emit light.

[46th Embodiment]

FIG. 124 is a side view of the light emitting device of the forty-sixth embodiment of the present invention, and FIG. 125 is a perspective view of the light emitting device. In this 46th embodiment, any one of the rod-shaped structure light emitting elements of the light emitting device of the 39th to 45th embodiments is used. 125, the rod-shaped structure light emitting element of the same structure as the rod-shaped structure light emitting element of the light-emitting device of 40th Embodiment is shown.

As shown in FIGS. 124 and 125, the light emitting device of the forty-fifth embodiment has an insulating substrate 450 having metal electrodes 461 and 462 formed on the mounting surface thereof, and an insulating substrate having a longitudinal direction on the insulating substrate 450. The rod-shaped structure light emitting element 460 mounted so as to be parallel to the mounting surface of the 450 is provided. The insulating substrate 450 is provided with a third metal electrode 463 as an example of the metal portion between the metal electrodes 461 and 462 on the insulating substrate 450 and under the rod-shaped structure light emitting element 460. 125 shows only a part of the metal electrodes 461, 462, and 463.

As shown in FIG. 125, the rod-shaped structure light emitting device 460 is formed so as to cover a portion of the semiconductor core 471 made of a rod-shaped n-type GaN having a substantially hexagonal cross section and a portion of the semiconductor core 471. A quantum well layer 472 made of type InGaN and a semiconductor layer 473 made of p-type GaN formed to cover the quantum well layer 472. The semiconductor core 471 has an exposed portion 1371a exposing an outer circumferential surface of one end thereof. The end surface on the other end side of the semiconductor core 471 is covered with the quantum well layer 472 and the semiconductor layer 473.

As shown in FIGS. 124 and 125, the exposed portion 1372a on one end side of the rod-shaped structure light emitting element 460 is connected to the metal electrode 461, and the semiconductor on the other end side of the rod-shaped structure light emitting element 460 is provided. The layer 473 is connected to the metal electrode 462. Here, the center part of the rod-shaped structure light emitting element 460 is connected to the metal electrode 463.

In addition, both ends of the rod-shaped structure light emitting device 460 are connected between the metal electrodes 461 and 462 formed at predetermined intervals on the insulating substrate 450, and the bars between the metal electrodes 461 and 462 on the insulating substrate 450 are also connected. Since the metal part is formed under the shape-structure light emitting element 460, the center side of the rod-shaped structure light emitting element 460 connected to the metal electrodes 461 and 462 is supported by contacting the surface of the third metal electrode 463. The rod-shaped structure light emitting element 460 of both supports is supported by the metal electrode 463 without bending, and heat generated by the rod-shaped structure light emitting element 460 is transferred from the semiconductor layer 473 to the metal electrode 463. Through the insulating substrate 450 can be efficiently radiated heat.

As shown in FIG. 126, each of the metal electrode 461 and the metal electrode 462 has the bases 461a and 462a which are substantially parallel to each other at predetermined intervals from the opposing positions of the bases 461a and 462a. It has a plurality of electrode portions 461b and 462b extending between the bases 461a and 462a. One rod-shaped structure light emitting element 460 is arranged in the electrode portion 461b of the metal electrode 461 and the electrode portion 462b of the metal electrode 462 facing it. Between the electrode portion 461b of the metal electrode 461 and the electrode portion 462b of the metal electrode 462 facing it, a butterfly-shaped third metal electrode 463 having a narrow central portion is formed on the insulating substrate 450. To form.

The third metal electrodes 463 adjacent to each other are electrically separated from each other, and as shown in FIG. 126, even when the directions of the rod-shaped structure light emitting elements 460 adjacent to each other are reversed, the metal electrodes are passed through the metal electrodes 463. The short circuit of the 461 and the metal electrode 462 can be prevented.

In the 39th to 46th embodiments, exposed portions 311a, 321a, 331a, 341a, and 351a in which outer peripheral surfaces of one end of the semiconductor cores 311, 321, 331, 341, 351, 361, 371, 381, and 471 are exposed. Although the rod-shaped structure light emitting device having 361a, 371a, 381a, and 471a has been described, the present invention is not limited to this, and may have an exposed portion where the outer peripheral surfaces of both ends of the semiconductor core are exposed. The outer peripheral surface may have an exposed part.

In the 39 th to 46 th embodiments, the semiconductor cores 311, 321, 331, 341, 351, 361, 371, 381, 471 and the semiconductor layers 312, 323, 332, 343, 352, 363, 372, 383 and 473), the present invention may be applied to a light emitting device using a semiconductor composed of GaAs, AlGaAs, GaAsP, InGaN, AlGaN, GaP, ZnSe, AlGaInP or the like. In addition, although the semiconductor core is n-type and the semiconductor layer is p-type, you may apply this invention to the rod-shaped structure light emitting element whose electroconductive type is the opposite.

In addition, in the 39th to 42nd embodiments, the rod-shaped structure light emitting device has a diameter of 1 µm and a micro order size of 20 µm in length, but at least a diameter or length of the nanoorder device having a diameter of less than 1 µm may be used. good. The diameter of the semiconductor core of the rod-shaped light emitting device is preferably 500 nm or more and 50 μm or less, and the variation in the diameter of the semiconductor core can be suppressed as compared with the rod-shaped light emitting device having a diameter of the semiconductor core of several tens of nm to several hundred nm. It is possible to reduce the variation in the light emitting area, that is, the light emitting characteristics, and improve the yield.

In the 39 th to 46 th embodiments, the semiconductor cores 311, 321, 331, 341, 351, 361, 371, 381, 471 are grown by using a MOCVD apparatus. However, the semiconductor core may be formed using another crystal growth apparatus such as a molecular beam epitaxial (MBE) apparatus. In addition, although the semiconductor core is crystal-grown on the substrate using a mask having growth holes, the semiconductor core may be crystal-grown from the metal species by disposing a metal species on the substrate.

In addition, the rod-shaped structure light emitting devices 310, 320, 330, 340, 350, 360, 370, 380, and 460 of the 39th to 46th embodiments have semiconductor layers 312, 323, 332, 343, 352, and 363. Semiconductor cores 311, 321, 331, 341, 351, 361, 371, 381, and 471 covered with, 372, 383, and 473 were separated from the substrate using ultrasonic waves, but not limited thereto. The semiconductor core may be separated from the substrate by mechanical bending. In this case, a plurality of fine rod-shaped structure light emitting elements provided on the substrate can be separated in a short time by a simple method.

Further, in the forty-fifth embodiment, the rod-shaped structure light emitting device 460 is arranged between the metal electrodes 451 and 452 by applying a potential difference to the two metal electrodes 451 and 452 formed on the surface of the insulating substrate 450. It is not limited, The 3rd electrode like 46th Embodiment is formed between two electrodes formed in the surface of an insulated substrate, and independent voltage is applied to each of the 3 electrodes, and a rod-shaped light emitting element is placed at a position defined by the electrode. You may arrange.

In addition, although the back light, the lighting device, and the display device provided with the light emitting device were described in the forty-fifth embodiment, the present invention is not limited thereto, and may be applied to other devices.

As mentioned above, although embodiment of this invention was described, it is clear that this may be variously changed. Such changes should not be regarded as deviating from the spirit and scope of the present invention, and obvious changes to those skilled in the art are intended to be included within the scope of the claims that follow.

Claims (20)

A rod-shaped first conductive semiconductor core; And
And a second conductive semiconductor layer formed to cover the semiconductor core:
An outer circumferential surface of a portion of the semiconductor core is exposed, wherein the rod-shaped structure light emitting device. A catalyst metal layer forming step of forming an island-shaped catalyst metal layer on a first conductivity type substrate;
A semiconductor core forming step of forming a rod-shaped first conductive semiconductor core by crystal-growing a first conductive semiconductor from an interface between the island-shaped catalyst metal layer and the substrate on the substrate on which the island-shaped catalyst metal layer is formed. ;
A second covering the surface of the semiconductor core by crystal growth from an outer circumferential surface of the semiconductor core and an interface between the island-shaped catalyst metal layer and the semiconductor core while the island-like catalyst metal layer is held at the tip of the semiconductor core A semiconductor layer forming step of forming a conductive semiconductor layer;
An exposure step of exposing an outer peripheral surface of the semiconductor core on the substrate side; And
And a separation step of separating the semiconductor core including the exposed portion exposed in the exposure step from the substrate. A catalyst metal layer forming step of forming an island-shaped catalyst metal layer on a first conductivity type substrate;
A semiconductor core forming step of forming a rod-shaped first conductive semiconductor core by crystal-growing a first conductive semiconductor from an interface between the island-shaped catalyst metal layer and the substrate on the substrate on which the island-shaped catalyst metal layer is formed. ;
A quantum well covering the surface of the semiconductor core by crystal growth from an outer circumferential surface of the semiconductor core and an interface between the island-shaped catalyst metal layer and the semiconductor core while the island-like catalyst metal layer is held at the tip of the semiconductor core. A quantum well layer forming process of forming a layer;
A semiconductor layer forming step of forming a second conductive semiconductor layer covering the surface of the quantum well layer;
An exposure step of exposing an outer peripheral surface of the semiconductor core on the substrate side; And
And a separation step of separating the semiconductor core including the exposed portion exposed in the exposure step from the substrate. A rod-shaped first conductive semiconductor core;
A cap layer covering one end surface of the semiconductor core; And
And a second conductive semiconductor layer covering an outer circumferential surface of a portion other than the exposed portion of the semiconductor core so as to be an exposed portion without covering the portion opposite to the portion of the semiconductor core covered with the cap layer:
The cap layer is a rod-shaped structure light emitting device, characterized in that made of a material having a larger electrical resistance than the semiconductor layer. The method of claim 4, wherein
A rod-shaped structure light emitting device comprising a conductive layer having a lower resistance than the semiconductor layer so as to cover the semiconductor layer. The rod-shaped structure light emitting device according to claim 4 or 5; And
And a substrate on which the rod-shaped light emitting device is mounted such that a longitudinal direction of the rod-shaped light emitting device is parallel to a mounting surface:
Electrodes are formed on the substrate at predetermined intervals;
On the other end side of the rod-shaped structured light emitting device, the exposed portion on one end side of the semiconductor core is connected to the electrode on the substrate, and the cap layer of the semiconductor core is provided on the other electrode on the substrate. The semiconductor device is connected, The light emitting device characterized by the above-mentioned. The rod-shaped structure light emitting device according to claim 5; And
And a substrate on which the rod-shaped light emitting device is mounted such that a longitudinal direction of the rod-shaped light emitting device is parallel to a mounting surface:
Electrodes are formed on the substrate at predetermined intervals;
The exposed portion on one end of the semiconductor core of the rod-shaped structure light emitting element is connected to one of the electrodes on the substrate;
The said light-emitting device of the other end in which the said cap layer of the said semiconductor core was provided to the said other electrode on the said board | substrate is connected. As a manufacturing method of the light-emitting device provided with the rod-shaped structure light emitting element of any one of Claims 4, 5, or 7.
A substrate creation step of creating an insulating substrate on which an array region of two or more electrodes to which independent potentials are applied is formed;
A coating step of applying a liquid including the rod-shaped structure light emitting device having a nano order size or micro order size on the insulating substrate; And
And a step of arranging the rod-shaped structure light emitting elements at positions defined by the two or more electrodes by applying the independent voltages to the two or more electrodes, respectively. A rod-shaped first conductive semiconductor core; And
And a second conductive semiconductor layer covering a portion other than the exposed portion of the semiconductor core so as to be an exposed portion without covering a portion on one end side of the semiconductor core:
And a stepped portion is formed between the outer circumferential surface of the exposed portion not covered with the semiconductor layer of the semiconductor core and the outer circumferential surface of the covered portion covered with the semiconductor layer of the semiconductor core. The method of claim 9,
A rod-shaped structure light emitting device comprising a conductive layer formed to cover the semiconductor layer and made of a material having a lower electrical resistance than the semiconductor layer. The rod-shaped structure light emitting device according to claim 9 or 10; And
And a substrate on which the rod-shaped light emitting device is mounted such that a longitudinal direction of the rod-shaped light emitting device is parallel to a mounting surface:
Electrodes are formed on the substrate at predetermined intervals;
The exposed portion on one end side of the semiconductor core of the rod-shaped light emitting element is connected to one electrode on the substrate, and the semiconductor layer on the other end side of the semiconductor core is connected to the other electrode on the substrate. A light emitting device, characterized in that connected. The rod-shaped structure light emitting device according to claim 10; And
And a substrate on which the rod-shaped light emitting device is mounted such that a longitudinal direction of the rod-shaped light emitting device is parallel to a mounting surface:
Electrodes are formed on the substrate at predetermined intervals;
The exposed portion on one end side of the semiconductor core of the rod-shaped light emitting element is connected to one electrode on the substrate, and the conductive layer on the other end side of the semiconductor core is connected to the other electrode on the substrate. A light emitting device, characterized in that connected. A manufacturing method of a light emitting device comprising the rod-shaped light emitting device according to claim 9 or 10.
A substrate creation step of creating an insulating substrate on which an array region of two or more electrodes to which independent potentials are applied is formed;
A coating step of applying a liquid including the rod-shaped structure light emitting device having a nano order size or micro order size on the insulating substrate; And
And a step of arranging the rod-shaped structure light emitting elements at positions defined by the two or more electrodes by applying the independent voltages to the two or more electrodes, respectively. A semiconductor core forming step of forming a rod-shaped first conductive semiconductor core on a substrate;
A semiconductor layer forming step of forming a cylindrical second conductive semiconductor layer covering a surface of the semiconductor core;
A separation step of separating the semiconductor core having the cylindrical second conductive semiconductor layer formed in the semiconductor layer forming step from the substrate; And
And an exposure step of exposing a part of an outer circumferential surface of the semiconductor core after the semiconductor layer forming step and before the separation step or after the separation step. As a manufacturing method of the display apparatus provided with the rod-shaped structure light emitting element manufactured by the manufacturing method of the rod-shaped structure light emitting element of Claim 14.
A substrate creation step of creating an insulating substrate on which an array region of two or more electrodes to which independent potentials are applied is formed;
A coating step of applying a liquid including the rod-shaped structure light emitting device having a nano order size or micro order size on the insulating substrate; And
And an arrangement step of applying the independent voltages to the two or more electrodes, respectively, to arrange the rod-shaped structure light emitting elements at the positions defined by the two or more electrodes. An insulator formation step of forming an insulator having a through hole on the substrate;
A semiconductor core forming step of forming a rod-shaped first conductive semiconductor core so as to protrude from the through hole on the surface of the substrate overlapping the through hole;
A semiconductor layer forming step of forming a second conductive semiconductor layer so as to cover the semiconductor core protruding from the through hole;
An insulator etching step of etching the insulator so that a part of the insulator remains on at least a portion of the outer circumference not covered with the semiconductor layer of the semiconductor core, covered by the semiconductor layer of the semiconductor core; And
And a separation step of separating the rod-shaped structure light emitting element having a portion of the insulator remaining on the substrate in the semiconductor core, the semiconductor layer, and the insulator etching step from the substrate. Method of manufacturing the device. A base layer forming step of forming a base layer made of a first conductive semiconductor on the substrate;
An insulator formation step of forming an insulator having a through hole on the base layer;
A semiconductor core forming step of forming a rod-shaped first conductive semiconductor core so as to protrude from the through hole on the surface of the base layer overlapping the through hole;
A semiconductor layer forming step of forming a second conductive semiconductor layer so as to cover the semiconductor core protruding from the through hole;
At the end of the substrate side of the semiconductor core so that a part of the insulator remains on at least a portion of the outer circumferential surface not covered with the semiconductor layer of the semiconductor core, covered by the semiconductor layer of the semiconductor core. An etching step of etching the insulator and the underlayer so that a portion of the underlayer continues in succession; And
A rod-shaped structure light emitting element having the semiconductor core, the semiconductor layer, a part of the insulator remaining on the substrate in the etching process, and a part of the base layer remaining on the substrate in the etching process, is formed from the substrate. A method of manufacturing a rod-shaped structure light emitting device, comprising a separation step of separating. A rod-shaped first conductive semiconductor core;
A second conductive semiconductor layer covering one end side of the semiconductor core; And
And an insulator covering at least a portion of the outer circumferential surface of the semiconductor core covered with the semiconductor layer of the semiconductor core, among the outer circumferential surfaces not covered with the semiconductor layer. A rod-shaped first conductive semiconductor core;
A second conductive semiconductor layer covering one end side of the semiconductor core;
An insulator covering at least a portion of an outer circumferential surface of the semiconductor core that is covered by the semiconductor layer of the semiconductor core, among the outer circumferential surfaces of the semiconductor core that are not covered by the semiconductor layer; And
And a base layer of a first conductivity type connected to the other end of the semiconductor core:
An axial end surface on the side opposite to the semiconductor core side of the base layer and a circumferential surface of the base layer are exposed. A rod-shaped structure light emitting device having a rod-shaped first conductive semiconductor core and a second conductive semiconductor layer formed to cover the semiconductor core, and having an outer peripheral surface of a portion of the semiconductor core exposed; And
And a substrate on which the rod-shaped light emitting element is mounted so that the longitudinal direction of the rod-shaped light emitting element is parallel to the mounting surface.

Images