JP2011119586A - Rod-like structure light emitting element, backlight, lighting system, and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a minute rod-like light emitting element which can extract light efficiently. <P>SOLUTION: The rod-like structure light emitting element includes a rod-like body 1. The body 1 includes a first semiconductor part 2 formed of n-type GaN, and a second semiconductor part 3 being in contact with the first semiconductor part 2 and formed of p-type GaN. A boundary surface of the first semiconductor part 2 and the second semiconductor part 3 is a light emitting surface 4. Projections and recesses are formed on axial one end surface 5 of the body 1. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rod-shaped structure light emitting element, a backlight, a lighting device, and a display device.

  Conventionally, as a rod-shaped structure light emitting element, there is one disclosed in JP 2008-34482 A (Patent Document 1). The light emitting device includes a substrate and a rod-shaped GaN nanocolumn formed on the substrate. This GaN nanocolumn extends in a direction perpendicular to the upper surface of the substrate (surface on the GaN nanocolumn side). The GaN nanocolumn is composed of an n-type GaN layer, a light emitting layer, and a p-type GaN layer arranged in the vertical direction.

  However, the conventional bar-structure light emitting element has a problem that light emitted from the light emitting layer is confined in the GaN nanocolumn, and thus light cannot be efficiently extracted from the GaN nanocolumn.

JP 2008-34482 A

  Therefore, an object of the present invention is to provide a fine bar-shaped light emitting element that can efficiently extract light.

In order to solve the above problems, the rod-shaped structure light emitting device of the present invention is
It has a body that extends like a rod and generates light inside,
At least one of a concave portion and a convex portion is formed on the end face in the axial direction of the main body.

  According to the above configuration, even in a micro-order size or nano-order size fine rod-shaped structure light emitting element, at least one of a concave portion and a convex portion is formed on the axial end surface of the main body. The light that occurs inside and reaches the end face without going outside due to the waveguide effect passes through the end face and efficiently goes out of the main body.

  Therefore, it is possible to realize a fine rod-shaped structure light emitting element that can extract light efficiently.

  If the end face in the axial direction of the main body is flat, the light generated inside the main body is reflected by the side face of the main body and the end face in the axial direction of the main body, so that the extraction efficiency is lowered.

  Here, the fine rod-shaped structure light emitting element is, for example, an element having a diameter of 10 nm to 5 μm, more preferably a size of 100 nm to 2 μm and a length of 100 nm to 200 μm, more preferably 1 μm to 50 μm.

  Moreover, the rod-shaped structure light emitting element can realize a backlight, a lighting device, a display device, and the like with high luminous efficiency and power saving.

In the rod-shaped structure light emitting device of one embodiment,
The main body is disposed on the surface of the substrate, and the axial direction of the main body is substantially parallel to the surface of the substrate.

  According to the embodiment, the main body is disposed on the surface of the substrate, and the axial direction of the main body is substantially parallel to the surface of the substrate, so that the thickness can be reduced.

In the rod-shaped structure light emitting device of one embodiment,
The size of the concave portion or the convex portion is 1/10 or more of the wavelength of the light.

  According to the embodiment, since the size of the concave portion or the convex portion is 1/10 or more of the wavelength of the light generated inside the main body, the reflection of the light at the end surface where the concave portion or the convex portion is formed. Can be reduced.

In the rod-shaped structure light emitting device of one embodiment,
The size of the concave portion or the convex portion is 1/5 or more of the wavelength of the light.

  According to the embodiment, since the size of the concave portion or the convex portion is 1/5 or more of the wavelength of the light generated inside the main body, the reflection of the light at the end surface where the concave portion or the convex portion is formed. Can be further reduced.

In the rod-shaped structure light emitting device of one embodiment,
The material of the convex part is different from the material of other parts of the main body.

  According to the above embodiment, since the material of the convex portion is different from the material of other parts of the main body, the convex portion is formed on the end surface in the axial direction of the main body without scraping the main body or damaging the main body. Thus, reflection at the end face can be reduced.

In the rod-shaped structure light emitting device of one embodiment,
The main body
A first conductivity type semiconductor;
And a second conductivity type semiconductor arranged in the axial direction of the main body with respect to the first conductivity type semiconductor.

  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 the first conductivity type is N type.

  According to the embodiment, since the second conductive semiconductor is aligned in the axial direction of the main body with respect to the first conductive semiconductor, the length in the direction orthogonal to the axial direction can be reduced.

In the rod-shaped structure light emitting device of one embodiment,
A quantum well layer is formed between the first conductive semiconductor and the second conductive semiconductor.

  According to the embodiment, since the quantum well layer is formed between the first conductivity type semiconductor and the second conductivity type semiconductor, the light emission efficiency can be further increased by the quantum confinement effect of the quantum well layer. .

In the rod-shaped structure light emitting device of one embodiment,
The main body
A first conductivity type semiconductor;
And a second conductivity type semiconductor that covers at least a part of the first conductivity type semiconductor concentrically.

  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 the first conductivity type is N type.

  According to the embodiment, the second conductivity type semiconductor covers at least a part of the first conductivity type semiconductor concentrically, so that the light emission area can be increased.

In the rod-shaped structure light emitting device of one embodiment,
A quantum well layer is formed between the first conductive semiconductor and the second conductive semiconductor.

  According to the embodiment, since the quantum well layer is formed between the first conductivity type semiconductor and the second conductivity type semiconductor, the light emission efficiency can be further increased by the quantum confinement effect of the quantum well layer. .

The backlight of the present invention is
The rod-shaped structure light emitting device of the present invention is provided.

  According to the said structure, since the said rod-shaped structure light emitting element is provided, the light emission efficiency is high and a power-saving backlight is realizable.

The lighting device of the present invention is
The rod-shaped structure light emitting device of the present invention is provided.

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

The display device of the present invention includes:
The rod-shaped structure light emitting device of the present invention is provided.

  According to the said structure, since the said rod-shaped structure light emitting element is provided, the display apparatus with high luminous efficiency and power saving is realizable.

  The rod-shaped structure light emitting device of the present invention is generated inside the main body because at least a concave portion or a convex portion is formed on the end surface in the axial direction of the main body even if it is a minute size such as a micro order size or a nano order size. The light passes through the end face and goes out of the main body efficiently.

  Therefore, it is possible to realize a fine rod-shaped structure light emitting element that can extract light efficiently.

  Since the backlight of the present invention includes the rod-shaped structure light emitting element, the light emission efficiency can be increased and the power saving backlight can be obtained.

  Since the illuminating device of the present invention includes the rod-shaped structure light emitting element, the illuminating efficiency can be increased and a power saving illuminating device can be obtained.

  Since the display device of the present invention includes the rod-shaped structure light emitting element, the light emission efficiency can be increased and a power saving display device can be obtained.

FIG. 1 is a schematic cross-sectional view of a rod-shaped structure light emitting device according to a first embodiment of the present invention. FIG. 2A is a process diagram of the method for manufacturing the rod-shaped structure light emitting device of the first embodiment. FIG. 2B is a process diagram of the manufacturing method of the rod-shaped structure light emitting element next to FIG. 2A. FIG. 2C is a process diagram of the manufacturing method of the rod-shaped structure light emitting element next to FIG. 2B. FIG. 2D is a process diagram of the manufacturing method of the rod-shaped structure light emitting device next to FIG. 2C. FIG. 2E is a process diagram of the manufacturing method of the rod-shaped structure light emitting element next to FIG. 2D. FIG. 3 is a schematic cross-sectional view of a bar-shaped structure light emitting device of a comparative example. FIG. 4A is a schematic cross-sectional view of the rod-shaped structure light emitting element and the insulating substrate of the first embodiment. FIG. 4B is a schematic cross-sectional view of the rod-shaped structure light emitting element and the insulating substrate of the first embodiment. FIG. 5 is a graph showing the relationship between the size of the concavities and convexities on the one end surface in the axial direction of the main body and the reflectance of the one end surface in the axial direction of the main body. FIG. 6 is a schematic cross-sectional view of a rod-shaped structure light emitting element and an insulating substrate according to a modification of the first embodiment. FIG. 7 is a schematic cross-sectional view of a rod-shaped structure light emitting element and an insulating substrate according to another modification of the first embodiment. FIG. 8 is a schematic cross-sectional view of a rod-shaped structure light emitting device according to a second embodiment of the present invention. FIG. 9A is a process diagram of the method for manufacturing the rod-shaped structure light emitting device of the second embodiment. FIG. 9B is a process diagram of the manufacturing method of the rod-shaped structure light emitting element next to FIG. 9A. FIG. 9C is a process diagram of the manufacturing method of the rod-shaped structure light emitting element next to FIG. 9B. FIG. 9D is a process diagram of the manufacturing method of the rod-shaped structure light emitting element next to FIG. 9C. FIG. 9E is a process diagram of the manufacturing method of the rod-shaped structure light emitting element next to FIG. 9D. FIG. 10A is a schematic cross-sectional view of the rod-shaped structure light emitting element and the insulating substrate of the second embodiment. FIG. 10B is a schematic cross-sectional view of the rod-shaped structure light emitting element and the insulating substrate of the second embodiment. FIG. 11 is a schematic cross-sectional view of a rod-shaped structure light emitting device according to a third embodiment of the present invention. FIG. 12A is a process diagram of the method for manufacturing the rod-shaped structure light emitting device of the third embodiment. FIG. 12B is a process diagram of the manufacturing method of the rod-shaped structure light emitting element next to FIG. 12A. FIG. 12C is a process diagram of the manufacturing method of the rod-shaped structure light emitting element next to FIG. 12B. FIG. 12D is a process diagram of the manufacturing method of the rod-shaped structure light emitting element next to FIG. 12C. FIG. 12E is a process diagram of the manufacturing method of the rod-shaped structure light emitting element next to FIG. 12D. FIG. 13A is a schematic cross-sectional view of the rod-shaped structure light emitting element and the insulating substrate of the third embodiment. FIG. 13B is a schematic cross-sectional view of the rod-shaped structure light emitting element and the insulating substrate of the third embodiment. FIG. 14 is a schematic cross-sectional view of a rod-shaped structure light emitting device according to a fourth embodiment of the present invention. FIG. 15A is a process diagram of the method for manufacturing the rod-shaped structure light emitting device of the fourth embodiment. FIG. 15B is a process diagram of the manufacturing method of the rod-shaped structure light emitting element next to FIG. 15A. FIG. 15C is a process diagram of the manufacturing method of the next rod-shaped structure light emitting element of FIG. 15B. FIG. 15D is a process drawing of the manufacturing method of the rod-shaped structure light emitting element next to FIG. 15C. FIG. 15E is a process diagram of the manufacturing method of the rod-shaped structure light emitting element next to FIG. 15D. FIG. 16A is a schematic cross-sectional view of the rod-shaped structure light emitting element and the insulating substrate of the fourth embodiment. FIG. 16B is a schematic cross-sectional view of the rod-shaped structure light emitting element and the insulating substrate of the fourth embodiment. FIG. 17 is a plan view of an insulating substrate used in a backlight, a lighting device, and a display device including a bar-shaped light emitting element according to a fifth embodiment of the present invention. 18 is a schematic cross-sectional view taken along line XVIII-XVIII in FIG. FIG. 19 is a view for explaining the principle of arranging the bar-shaped structured light emitting elements of the fifth embodiment. FIG. 20 is a diagram for explaining the potential applied to the electrodes when arranging the rod-like structure light emitting elements of the fifth embodiment. FIG. 21 is a plan view of an insulating substrate on which the rod-like structure light emitting elements of the fifth embodiment are arranged. FIG. 22 is a plan view of the display device. FIG. 23 is a circuit diagram of a main part of the display unit of the display device. FIG. 24A is a process diagram of a method for manufacturing an apparatus including a rod-shaped structure light emitting element according to a modification of the first and second embodiments. FIG. 24B is a process diagram of a method for manufacturing the next apparatus of FIG. 24A. FIG. 24C is a process diagram of a method for manufacturing the next apparatus of FIG. 24B. FIG. 24D is a process diagram of a method for manufacturing the next apparatus of FIG. 24C. FIG. 24E is a process diagram of a method for manufacturing the next apparatus of FIG. 24D. FIG. 24F is a process diagram of a method for manufacturing the next apparatus of FIG. 24E. FIG. 24G is a process diagram of a method for manufacturing the next apparatus of FIG. 24F. FIG. 24H is a process diagram of a method for manufacturing the next apparatus of FIG. 24G. FIG. 24I is a process diagram of a method for manufacturing the next apparatus of FIG. 24H. FIG. 24J is a process diagram of a method for manufacturing the next apparatus of FIG. 24I. FIG. 25A is a process diagram of a method for manufacturing an apparatus including a rod-shaped structure light emitting element according to a modification of the first to fourth embodiments. FIG. 25B is a process diagram of a method for manufacturing the next apparatus of FIG. 25A. FIG. 25C is a process diagram of a method for manufacturing the next apparatus of FIG. 25B. FIG. 25D is a process diagram of a method for manufacturing the next apparatus of FIG. 25C. FIG. 25E is a process diagram of a method for manufacturing the next apparatus of FIG. 25D. FIG. 25F is a process diagram of a method for manufacturing the next apparatus of FIG. 25E. FIG. 25G is a process diagram of a method for manufacturing the next apparatus of FIG. 25F. FIG. 25H is a process diagram of a method for manufacturing the next apparatus of FIG. 25G. FIG. 25I is a process diagram of a method for manufacturing the next apparatus of FIG. 25H. FIG. 25J is a process diagram of a method for manufacturing the next apparatus of FIG. 25I. FIG. 25K is a process diagram of a method for manufacturing the next apparatus of FIG. 25J.

  Hereinafter, the rod-shaped structure light emitting element, backlight, illumination device and display device of the present invention will be described in detail with reference to the illustrated embodiments.

[First Embodiment]
FIG. 1 is a schematic cross-sectional view of a rod-shaped structure light emitting device according to a first embodiment of the present invention.

  The rod-shaped structure light emitting element of the first embodiment includes a rod-shaped main body 1 having a substantially circular cross section. The main body 1 has a first semiconductor part 2 made of n-type GaN and a second semiconductor part 3 made of p-type GaN in contact with the first semiconductor part 2. A boundary surface with the second semiconductor unit 3 is a light emitting surface 4. Further, an unevenness is formed on one end face 5 in the axial direction of the main body 1. On the other hand, the other end surface 6 of the main body 1 in the axial direction is a substantially flat surface. Further, the outer peripheral surface of the first semiconductor unit 2 is smoothly continuous with the outer peripheral surface of the second semiconductor unit 3. That is, the outer peripheral surface of the first semiconductor unit 2 is substantially flush with the outer peripheral surface of the second semiconductor unit 3. The second semiconductor part 3 is formed so as to be aligned in the axial direction of the main body 1 with respect to the first semiconductor part 2. The first semiconductor unit 2 is an example of a first conductivity type semiconductor, and the second semiconductor unit 3 is an example of a second conductivity type semiconductor. Further, the outer peripheral surface of the first semiconductor unit 2 may be formed to have a step with respect to the outer peripheral surface of the second semiconductor unit 3.

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

First, as shown in FIG. 2A, a mask 12 having a plurality of growth holes 13, 13,... (Only two are shown in FIG. 2A) is formed on a substrate 11 made of n-type GaN. The mask 12 is made of a material that can be selectively etched with respect to the first semiconductor portion 2 and the second semiconductor portion 3 such as silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ). For the formation of the growth holes 13, 13,..., Known lithography methods and dry etching methods used in ordinary semiconductor processes can be used.

Next, crystal growth of n-type GaN is performed on the substrate 11 exposed by the growth holes 13, 13,... Of the mask 12 by using a MOCVD (Metal Organic Chemical Vapor Deposition) apparatus. As shown in FIG. 2B, the first semiconductor portion 2 is formed in each growth hole 13. More specifically, the temperature of the MOCVD apparatus is set to about 950 ° C., trimethyl gallium (TMG) and ammonia (NH ₃ ) are used as growth gases, silane (SiH ₃ ) is supplied for supplying n-type impurities, and carrier gas As a result, hydrogen (H ₃ ) is supplied to grow the first semiconductor portion 2 made of n-type GaN with Si as an impurity. At this time, the first semiconductor portion 2 is grown to almost half the depth of the growth hole 13 of the mask 12. The diameter of the first semiconductor part 2 can be determined by the diameter of the growth hole 13 of the mask 12.

Next, a second semiconductor portion 3A made of p-type GaN is formed on each of the first semiconductor portions 2 described above. More specifically, the temperature of the MOCVD apparatus is set to about 960 ° C., trimethylgallium (TMG) and ammonia (NH ₃ ) are used as growth gases, and biscyclopentadienylmagnesium (Cp ₂ Mg) is used to supply p-type impurities. By using it, p-type GaN having magnesium (Mg) as an impurity can be grown.

  Next, as shown in FIG. 2C, a plurality of fine particles 14 are formed on the mask 12 and the second semiconductor portion 3A. The diameter of the fine particles 14 is about several tens of nm. Further, as the material of the fine particles 14, for example, gold can be used.

  Next, dry etching is performed to form irregularities (a rough surface, a jagged surface) on one end surface 5 in the axial direction of the rod-shaped main body 1 as shown in FIG. 2D. At this time, irregularities are also formed on the surface of the mask 12a.

Next, all of the mask 12a is removed, leaving only a plurality of main bodies 1, 1,... (Two shown in FIG. 2E) on the substrate 11, as shown in FIG. When the mask 12a is made of silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ), the first semiconductor unit 2 and the second semiconductor unit 3 are used by using a solution containing hydrofluoric acid (HF). The mask 12 can be easily etched without affecting the above.

  It should be noted that the rod-shaped main body may be grown without using the mask 12 having the growth holes 13, 13,. In that case, particles of catalyst metal (for example, Ni) are dispersed on the substrate, and a rod-like wire is grown under the catalyst metal by MOCVD. After the growth of the rod-shaped wire, an InN dot having a diameter of several tens of nm is formed on one end surface in the axial direction of the rod-shaped wire by SK (Stranski-Krastanov) growth, and further dry etching is performed to Concavities and convexities are formed on one end surface in the direction.

  Next, after the substrate 11 is immersed in an isopropyl alcohol (IPA) aqueous solution, the substrate 11 is vibrated along the plane of the substrate using ultrasonic waves (for example, several tens of kHz). As a result, stress is applied to the main bodies 1, 1,... So that the bases near the board 11 side of the main bodies 1, 1,. 11 is separated.

  In this way, a fine rod-shaped structure light emitting element separated from the substrate 11 made of n-type GaN can be manufactured.

  According to the rod-shaped structure light emitting element having the above configuration, the light emitted from the light emitting surface 4 travels toward the one end surface 5 in the axial direction of the main body 1 by the waveguiding effect, as indicated by an arrow in FIG. Since the one end surface 5 is formed with irregularities, light from the light emitting surface 4 passes through the one end surface 5 in the axial direction of the main body 1 even in a micro rod-sized or nano-order size light emitting element. Passes and goes out of the main body 1 efficiently.

  Therefore, it is possible to realize a fine rod-shaped structure light emitting element that can extract light efficiently. Since this rod-shaped structure light emitting element is separated from the substrate 11 and is not integrated with the substrate 11, the degree of freedom of mounting on the apparatus is high.

  FIG. 3 is a schematic cross-sectional view of a bar-shaped structure light emitting device of a comparative example.

  The bar-shaped structure light emitting element of the comparative example has the same configuration as the bar-shaped structure light emitting element of the first embodiment, except that the end face 55 in the axial direction of the main body 51 is a flat surface. That is, the main body 51 has a second semiconductor portion 53 having a shape different from that of the second semiconductor portion 3.

  According to such a rod-shaped structure light emitting device of the comparative example, the light emitted from the light emitting surface 54 is directed to the one end surface 55 in the axial direction of the main body 51 by the waveguiding effect as shown by the arrow in FIG. Since the one end surface 55 is a flat surface, the light from the light emitting surface 54 is reflected by the one end surface 5 in the axial direction of the main body 1, and the light from the light emitting surface 54 is confined in the main body 51.

  Here, the fine rod-shaped structure light emitting element is, for example, a micro-order size having a diameter of 1 μm and a length of 10 μm, but is not limited to this size, and the diameter is 10 nm to 5 μm, more preferably 100 nm to 2 μm. You may manufacture a fine rod-shaped structure light emitting element. The length of this fine rod-shaped structure light emitting element is 100 nm to 200 μm, more preferably 1 μm to 50 μm.

  Moreover, the rod-shaped structure light emitting element can realize a backlight, a lighting device, a display device, and the like with high luminous efficiency and power saving.

  Moreover, when taking out light from the rod-shaped structure light emitting element of this 1st Embodiment, as shown to FIG. 4A, the main body 1 is arrange | positioned on the surface of the insulating substrate 21, for example. At this time, the main body 1 is arranged so that the axial direction of the main body 1 is substantially parallel to the surface of the insulating substrate 21. The insulating substrate 21 is an example of a substrate.

  Next, as shown in FIG. 4B, the n-side contact metal 22 is connected to the first semiconductor portion 2 and the p-side contact metal 23 is connected to the second semiconductor portion 3 by, for example, vapor deposition or sputtering to emit light. Light is emitted from the light emitting surface 4 by passing a current from the p-side contact metal 23 to the n-side contact metal 22 so that recombination of electrons and holes occurs on the surface 4 (see FIG. 1).

  Thus, since the axial direction of the main body 1 is substantially parallel to the surface of the insulating substrate 21, the thickness can be reduced.

  FIG. 5 shows the change in the ratio of the size of the concavities and convexities of the end face 5 in the axial direction of the main body 1 to the wavelength of the light from the light emitting surface 4 and the axial direction of the main body 1 with respect to the end face 55 in the axial direction of the main body 51. It is a graph which shows the relationship with the change of the ratio of the reflectance of the end surface 5. FIG. In FIG. 5, the reflectance (with unevenness) is the reflectance of the one end surface 5 in the axial direction of the main body 1, and the reflectance (without unevenness) is the reflectance of the one end surface 55 in the axial direction of the main body 51. Further, the size of the unevenness is the size of deviation from the average value of one end face 5 of the main body 1. That is, the size of the unevenness refers to the mean square roughness obtained by the square root of the value obtained by averaging the squares of deviations from the mean line of the roughness curve to the measurement curve on one end face 5 of the main body 1.

  As is clear from FIG. 5, when the ratio of the size of the unevenness of the end surface 5 in the axial direction of the main body 1 to the wavelength of light from the light emitting surface 4 is 0.1 or more, the axial direction of the main body 1 is This is desirable because the reflection of the light at the end face 5 becomes very small.

  Further, when the ratio of the size of the unevenness of the one end surface 5 in the axial direction of the main body 1 to the wavelength of light from the light emitting surface 4 is 0.2 or more, the light on the one end surface 5 in the axial direction of the main body 1 This is more desirable because almost no reflection of the light is lost.

  As a rod-shaped structure light emitting element of a modified example of the first embodiment, there is one provided with a rod-shaped main body 61 having a substantially circular cross section shown in FIG. The main body 61 has a first semiconductor part 62 made of n-type GaN, a second semiconductor part 63 made of p-type GaN, and a quantum well layer 67 made of p-type InGaN. Further, an unevenness is formed on one end surface 65 of the main body 61 in the axial direction. On the other hand, the other end surface 66 in the axial direction of the main body 61 is a substantially flat surface. Further, the outer peripheral surface of the first semiconductor unit 62 is smoothly continuous with the outer peripheral surface of the second semiconductor unit 63. That is, the outer peripheral surface of the first semiconductor unit 62 is substantially flush with the outer peripheral surface of the second semiconductor unit 63. The second semiconductor part 63 is formed so as to be aligned with the first semiconductor part 62 in the axial direction of the main body 61. A quantum well layer 67 is disposed between the first semiconductor unit 62 and the second semiconductor unit 63. The first semiconductor unit 62 is an example of a first conductivity type semiconductor, the second semiconductor unit 63 is an example of a second conductivity type semiconductor, and the quantum well layer 67 is an example of a quantum well layer. Further, the outer peripheral surface of the first semiconductor portion 62 may be formed to have a step with respect to the outer peripheral surface of the second semiconductor portion 63.

  Thus, by arranging the quantum well layer 67 between the first semiconductor portion 62 and the second semiconductor portion 63, the light emission efficiency can be further improved by the quantum confinement effect of the quantum well layer 67.

  When light is extracted from the rod-shaped structure light emitting element including the main body 61, for example, the main body 1 is arranged on the surface of the insulating substrate 21 so that the axial direction of the main body 1 is substantially parallel to the surface of the insulating substrate 21. The n-side contact metal 22 is connected to the first semiconductor portion 62 and the p-side contact metal 23 is connected to the second semiconductor portion 63 by vapor deposition or sputtering, and electrons are emitted from the light emitting surface 4. A current may be passed from the p-side contact metal 23 to the n-side contact metal 22 so that hole recombination occurs.

Further, in the rod-shaped structure light emitting device including the main body 61, after forming the first semiconductor portion 62 in the same manner as the first semiconductor portion 2, trimethylgallium (TMG), ammonia (NH ₃ ) and trimethylindium (In) are used as growth gases. (CH ₃ ) ₃ ) is formed using biscyclopentadienylmagnesium (Cp ₂ Mg) for supplying p-type impurities, and then the quantum well layer 67 is formed. If 63 is formed, it can be manufactured.

  As another example of the rod-shaped structure light emitting element of the first embodiment, there is one having a rod-shaped main body 71 having a substantially circular cross section shown in FIG. The main body 71 has a first semiconductor part 72 made of n-type GaN and a second semiconductor part 73 made of p-type GaN. Further, an unevenness is formed on one end surface 75 of the main body 71 in the axial direction. On the other hand, the other end surface 76 of the main body 71 in the axial direction is a substantially flat surface. Further, the outer peripheral surface of the first semiconductor unit 72 is smoothly continuous with the outer peripheral surface of the second semiconductor unit 73. That is, the outer peripheral surface of the first semiconductor unit 72 is substantially flush with the outer peripheral surface of the second semiconductor unit 73. The second semiconductor portion 73 is formed so as to cover the outer peripheral surface on the one end surface 75 side of the first semiconductor portion 72. That is, the second semiconductor portion 73 partially covers the end portion on the one end face 75 side of the first semiconductor portion 72 in a concentric axis shape. Further, the end face in the axial direction on the one end face 75 side of the first semiconductor part 72 is completely covered with the second semiconductor part 73. The first semiconductor unit 72 is an example of a first conductivity type semiconductor, and the second semiconductor unit 73 is an example of a second conductivity type semiconductor. Further, the outer peripheral surface of the first semiconductor portion 72 may be formed to have a step with respect to the outer peripheral surface of the second semiconductor portion 73.

  Thus, since the second semiconductor portion 73 is formed so as to cover the one end surface 75 side of the first semiconductor portion 72, the contact area between the first semiconductor portion 72 and the second semiconductor portion 73 increases, and the light emission area. Can be greatly increased.

  When light is extracted from the rod-shaped structure light emitting element including the main body 71, for example, the main body 71 is arranged on the surface of the insulating substrate 21 so that the axial direction of the main body 71 is substantially parallel to the surface of the insulating substrate 21. And the n-side contact metal 22 is connected to the first semiconductor part 72 and the p-side contact metal 23 is connected to the second semiconductor part 73 by vapor deposition or sputtering, and electrons are emitted from the light emitting surface 4. A current may be passed from the p-side contact metal 23 to the n-side contact metal 22 so that hole recombination occurs.

  In the method of manufacturing the rod-shaped structure light emitting device including the main body 71, first, after forming rod-shaped n-type GaN on the substrate, the diameter of the tip of the n-type GaN is reduced by etching, so that the first semiconductor A portion 72 is formed. And after forming p-type GaN so that the front-end | tip part of the 1st semiconductor part 72 may be covered, on this p-type GaN, the diameter about tens of nanometers is formed, Furthermore, dry etching is performed, A second semiconductor portion 73 is formed.

  In addition, as a method for manufacturing a rod-shaped structure light emitting device including a main body such as the main body 71, after forming an n-type GaN film on a substrate, particles of catalyst metal (for example, Ni) are dispersed on the substrate, and MOCVD is performed. A rod-shaped n-type GaN wire is grown under the catalyst metal. After the growth of the n-type GaN wire, a p-type GaN film is grown on the upper surface (one axial end surface) and side surfaces of the n-type GaN wire and on the n-type GaN film by MOCVD. Then, InN dots having a diameter of several tens of nm are formed on the surface of the p-type GaN film by SK growth, and further, dry etching is performed to form irregularities on the surface of the p-type GaN film.

[Second Embodiment]
FIG. 8 is a schematic cross-sectional view of a rod-shaped structure light emitting device according to a second embodiment of the present invention.

  The rod-shaped structure light emitting device of the second embodiment includes a rod-shaped main body 201 having a substantially circular cross section. The main body 201 includes a first semiconductor portion 202 made of n-type GaAs and a second semiconductor portion 203 made of p-type GaAs in contact with the first semiconductor portion 202. A boundary surface with the second semiconductor unit 203 is a light emitting surface 204. A convex portion 208 is formed on one end surface 205 of the main body 201 in the axial direction. On the other hand, the other end surface 206 in the axial direction of the main body 201 is a substantially flat surface. Further, the outer peripheral surface of the first semiconductor unit 202 is smoothly continuous with the outer peripheral surface of the second semiconductor unit 203. That is, the outer peripheral surface of the first semiconductor unit 202 is substantially flush with the outer peripheral surface of the second semiconductor unit 203. The second semiconductor unit 203 is formed so as to be aligned with the first semiconductor unit 202 in the axial direction of the main body 201. The first semiconductor unit 202 is an example of a first conductivity type semiconductor, and the second semiconductor unit 203 is an example of a second conductivity type semiconductor. Further, the outer peripheral surface of the first semiconductor unit 202 may be formed to have a step with respect to the outer peripheral surface of the second semiconductor unit 203.

  The convex portion 208 is a part of the second semiconductor portion 203 and is made of p-type GaAs. The height H1 of the convex portion 208 is set to 1/10 or more of the wavelength of light emitted from the light emitting surface 204. The height H1 of the convex portion 208 may be set to 1/5 or more of the wavelength of light emitted from the light emitting surface 204.

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

First, as shown in FIG. 9A, a mask 212 having a plurality of growth holes 213, 213,... (Only two are shown in FIG. 9A) is formed on a substrate 211 made of n-type GaAs. The mask 212 is made of a material that can be selectively etched with respect to the first semiconductor portion 202 and the second semiconductor portion 203 such as silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ). The growth holes 213, 213,... Can be formed by a known lithography method and dry etching method used in a normal semiconductor process.

Next, an n-type GaAs crystal is grown on the substrate 211 exposed by the growth holes 213, 213,... Of the mask 212 by using an MOCVD apparatus, and as shown in FIG. The first semiconductor part 202 is formed. More specifically, the temperature of the MOVPE apparatus is set to about 750 ° C., trimethylgallium (TMG) and AsH ₃ are used as growth gases, and Si is used as an impurity by supplying silane (SiH ₃ ) as an n-type impurity. A first semiconductor portion 202 made of n-type GaAs is grown. At this time, the first semiconductor portion 202 is grown to almost half the depth of the growth hole 213 of the mask 212. Further, the diameter of the first semiconductor part 202 can be determined by the diameter of the growth hole 213 of the mask 212.

Next, a second semiconductor portion 203A made of p-type GaAs is formed on each of the first semiconductor portions 202. More specifically, the temperature of the MOVPE apparatus is set to about 750 ° C., trimethyl gallium (TMG) and AsH ₃ are used as growth gases, and TMZn is used as a p-type impurity supply to make zinc (Zn) an impurity. P-type GaAs can be grown.

Next, a part of the mask 212 is removed, and as shown in FIG. 9C, the end of the second semiconductor unit 203 opposite to the substrate 211 is exposed from the mask 212a. When the mask 212a is made of silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ), a solution containing hydrofluoric acid (HF) is used, whereby the first semiconductor portion 202 and the second semiconductor portion 203A. A part of the mask 212 can be easily etched without affecting the above.

  Next, for example, isotropic etching is performed on the end portion of the second semiconductor portion 203 opposite to the substrate 211 side to form a convex portion 208 as shown in FIG. 9D. This isotropic etching can be performed using, for example, a mixed solution of sulfuric acid, hydrogen peroxide solution, and water.

Next, the entire mask 212a is removed, and only a plurality of main bodies 201, 201,... (Two shown in FIG. 9E) are left on the substrate 211 as shown in FIG. When the mask 212a is made of silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ), a solution containing hydrofluoric acid (HF) is used, whereby the first semiconductor portion 202 and the second semiconductor portion 203 are used. The mask 212 can be easily etched without affecting the above.

  Next, after the substrate 211 is immersed in an isopropyl alcohol (IPA) aqueous solution, the substrate 211 is vibrated along the substrate plane using ultrasonic waves (for example, several tens of kHz). As a result, stress is applied to the main bodies 201, 201,... So that the bases close to the substrate 211 side of the main bodies 201, 201,. 211 is separated.

  In this way, a fine rod-shaped light emitting element separated from the substrate 211 made of n-type GaAs can be manufactured.

  According to the rod-shaped structure light emitting element having the above configuration, the light emitted from the light emitting surface 204 travels toward the one end surface 205 in the axial direction of the main body 201 by the waveguiding effect. Since the convex portion 208 is formed on the one end face 205, the light from the light emitting face 204 is axially one end face of the main body 201 even in a micro rod-sized or nano-order sized light emitting element. Passes 205 and goes out of the main body 201 efficiently.

  Therefore, it is possible to realize a fine rod-shaped structure light emitting element that can extract light efficiently. Since this rod-shaped structure light emitting element is not integrated with the substrate, the degree of freedom of mounting on the device is high.

  If the one end surface 205 of the main body 201 in the axial direction is flat, the light from the light emitting surface 204 is reflected by the one end surface 205, so that almost no light is emitted outside the main body 201.

  Here, the fine rod-shaped structure light emitting element is, for example, a micro-order size having a diameter of 1 μm and a length of 10 μm, but is not limited to this size, and the diameter is 10 nm to 5 μm, more preferably 100 nm to 2 μm. You may manufacture a fine rod-shaped structure light emitting element. The length of this fine rod-shaped structure light emitting element is 100 nm to 200 μm, more preferably 1 μm to 50 μm.

  In addition, since the height H1 of the convex portion 208 is 1/10 or more of the wavelength of the light emitted from the light emitting surface 204, the reflection of the light at the one end surface 205 where the convex portion 208 is formed is extremely reduced. Can do.

  Further, when light is extracted from the rod-shaped structure light emitting device of the second embodiment, for example, as shown in FIG. 10A, the main body 201 is disposed on the surface of the insulating substrate 221. At this time, the main body 201 is arranged so that the axial direction of the main body 201 is substantially parallel to the surface of the insulating substrate 221. Note that the insulating substrate 221 is an example of a substrate.

  Next, as shown in FIG. 10B, the n-side contact metal 222 is connected to the first semiconductor portion 202 and the p-side contact metal 223 is connected to the second semiconductor portion 203 by, for example, vapor deposition or sputtering, and light emission is performed. Light is emitted from the light emitting surface 204 by passing a current from the p-side contact metal 223 to the n-side contact metal 222 so that recombination of electrons and holes occurs on the surface 204.

  Thus, since the axial direction of the main body 201 is substantially parallel to the surface of the insulating substrate 221, the thickness can be reduced.

  In the second embodiment, the fine rod-shaped structure light emitting device is manufactured so that the p-type GaAs is aligned in the axial direction with respect to the n-type GaAs. However, a part of the p-type GaAs is radially aligned with respect to the n-type GaAs. You may manufacture a fine rod-shaped structure light emitting element so that it may rank.

[Third Embodiment]
FIG. 11 is a schematic cross-sectional view of a rod-shaped structure light emitting device according to a third embodiment of the present invention.

  The rod-shaped structure light emitting device of the third embodiment includes a rod-shaped main body 301 having a substantially circular cross section. The main body 301 includes a first semiconductor portion 302 made of p-type GaN and a second semiconductor portion 303 made of n-type GaN that contacts the first semiconductor portion 302. A boundary surface with the second semiconductor unit 303 is a light emitting surface 304. A recess 309 is formed on one end surface 305 in the axial direction of the main body 301. On the other hand, the other end surface 306 in the axial direction of the main body 301 is a substantially flat surface. In addition, the outer peripheral surface of the first semiconductor unit 302 is smoothly continuous with the outer peripheral surface of the second semiconductor unit 303. That is, the outer peripheral surface of the first semiconductor unit 302 is substantially flush with the outer peripheral surface of the second semiconductor unit 303. The second semiconductor portion 303 is formed so as to be aligned with the first semiconductor portion 302 in the axial direction of the main body 301. The first semiconductor unit 302 is an example of a first conductivity type semiconductor, and the second semiconductor unit 303 is an example of a second conductivity type semiconductor. Further, the outer peripheral surface of the first semiconductor unit 302 may be formed to have a step with respect to the outer peripheral surface of the second semiconductor unit 303.

  The depth D of the recess 309 is set to 1/10 or more of the wavelength of light emitted from the light emitting surface 304. The depth D of the recess 309 may be set to 1/5 or more of the wavelength of light emitted from the light emitting surface 304.

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

First, as shown in FIG. 12A, a mask 312 having a plurality of growth holes 313, 313,... (Only two are shown in FIG. 12A) is formed on a substrate 311 made of sapphire. The mask 312 is made of a material that can be selectively etched with respect to the first semiconductor portion 302 and the second semiconductor portion 303 such as silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ). The growth holes 313, 313,... Can be formed by a known lithography method and dry etching method used in a normal semiconductor process.

Next, an n-type GaN crystal is grown on the substrate 311 exposed by the growth holes 313, 313,... Of the mask 312 using an MOCVD apparatus, and the growth holes 313 are formed in each growth hole 313 as shown in FIG. A second semiconductor portion 303A is formed. More specifically, the temperature of the MOCVD apparatus is set to about 950 ° C., trimethyl gallium (TMG) and ammonia (NH ₃ ) are used as growth gases, silane (SiH ₃ ) is supplied for supplying n-type impurities, and carrier gas As a result, hydrogen (H ₃ ) is supplied to grow the second semiconductor portion 303A made of n-type GaN with Si as an impurity. At this time, the second semiconductor portion 303A is grown to almost half the depth of the growth hole 313 of the mask 312. Further, the diameter of the second semiconductor portion 303A can be determined by the diameter of the growth hole 313 of the mask 312.

Next, the first semiconductor portion 302 made of p-type GaN is formed on each of the second semiconductor portions 303A. More specifically, the temperature of the MOCVD apparatus is set to about 960 ° C., trimethylgallium (TMG) and ammonia (NH ₃ ) are used as growth gases, and biscyclopentadienylmagnesium (Cp ₂ Mg) is used to supply p-type impurities. By using it, p-type GaN having magnesium (Mg) as an impurity can be grown.

Next, the entire mask 312 is removed to obtain the state shown in FIG. 12C. In the case where the mask 312a is made of silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ), the first semiconductor portion 302 and the second semiconductor portion 303A are used by using a solution containing hydrofluoric acid (HF). The entire mask 312 can be easily etched without affecting the above.

  Next, for example, isotropic etching is performed on the substrate 311 to obtain a substrate 311a shown in FIG. 12D. The substrate 311a has a connection portion having a diameter smaller than that of the second semiconductor portion 303A, and the second semiconductor portion 303A is connected to the connection portion.

  Next, after the substrate 311a is immersed in an aqueous isopropyl alcohol (IPA) solution, the substrate 311 is vibrated along the substrate plane using ultrasonic waves (for example, several tens of kHz). As a result, stress acts on the base of the second semiconductor parts 303A, 303A,... Near the substrate 311a side, leaving a part of each of the second semiconductor parts 303A, 303A,. The remaining portions of the second semiconductor portions 303A, 303A,... Are separated from the substrate 311a. That is, as shown in FIG. 12E, a plurality of main bodies 301, 301,... (Only two are shown in FIG. 12E) are separated from the substrate 311a.

  In this way, a fine rod-shaped structure light emitting element separated from the substrate 311 made of n-type GaN can be manufactured.

  According to the rod-shaped structure light emitting element having the above configuration, the light emitted from the light emitting surface 304 is directed toward the one end surface 305 in the axial direction of the main body 301 by the waveguiding effect. Since the concave portion 309 is formed on the one end surface 305, the light from the light emitting surface 304 is transmitted to one end surface in the axial direction of the main body 301 even in a micro rod-sized or nano-order light emitting element. Passing through 305, it goes out of the main body 301 efficiently.

  Therefore, it is possible to realize a fine rod-shaped structure light emitting element that can extract light efficiently. Since this rod-shaped structure light emitting element is not integrated with the substrate, the degree of freedom of mounting on the device is high.

  If the one end surface 305 in the axial direction of the main body 301 is flat, the light from the light emitting surface 304 is reflected by the one end surface 305, so that almost no light is emitted outside the main body 301.

  Here, the fine rod-shaped structure light emitting element is, for example, a micro-order size having a diameter of 1 μm and a length of 10 μm, but is not limited to this size, and the diameter is 10 nm to 5 μm, more preferably 100 nm to 2 μm. You may manufacture a fine rod-shaped structure light emitting element. The length of this fine rod-shaped structure light emitting element is 100 nm to 200 μm, more preferably 1 μm to 50 μm.

  In addition, since the depth D of the concave portion 309 is 1/10 or more of the wavelength of light emitted from the light emitting surface 304, the reflection of the light at the one end surface 305 where the concave portion 309 is formed can be greatly reduced. .

  When light is extracted from the rod-shaped structure light emitting device of the third embodiment, for example, a main body 301 is disposed on the surface of an insulating substrate 321 as shown in FIG. 13A. At this time, the main body 301 is arranged so that the axial direction of the main body 301 is substantially parallel to the surface of the insulating substrate 321. Note that the insulating substrate 321 is an example of a substrate.

  Next, as shown in FIG. 13B, the n-side contact metal 322 is connected to the second semiconductor portion 303 and the p-side contact metal 323 is connected to the first semiconductor portion 302 by, for example, vapor deposition or sputtering, to emit light. Light is emitted from the light emitting surface 304 by passing a current from the p-side contact metal 323 to the n-side contact metal 322 so that recombination of electrons and holes occurs on the surface 304.

  Thus, since the axial direction of the main body 301 is substantially parallel to the surface of the insulating substrate 321, the thickness can be reduced.

[Fourth Embodiment]
FIG. 14 is a schematic cross-sectional view of a rod-shaped structure light emitting device according to a fourth embodiment of the present invention.

  The rod-shaped structure light emitting device of this embodiment includes a rod-shaped main body 401 having a substantially circular cross section. The main body 401 includes a first semiconductor portion 402 made of p-type GaN and a second semiconductor portion 403 made of n-type GaN in contact with the first semiconductor portion 402. A boundary surface with the second semiconductor unit 403 is a light emitting surface 404. A convex portion 408 is formed on one end surface 405 in the axial direction of the main body 401. On the other hand, the other end surface 406 in the axial direction of the main body 401 is a substantially flat surface. In addition, the outer peripheral surface of the first semiconductor unit 402 is smoothly continuous with the outer peripheral surface of the second semiconductor unit 403. That is, the outer peripheral surface of the first semiconductor unit 402 is substantially flush with the outer peripheral surface of the second semiconductor unit 403. The second semiconductor unit 403 is formed so as to be aligned with the first semiconductor unit 402 in the axial direction of the main body 401. The first semiconductor unit 402 is an example of a first conductivity type semiconductor, and the second semiconductor unit 403 is an example of a second conductivity type semiconductor. Further, the outer peripheral surface of the first semiconductor unit 402 may be formed to have a step with respect to the outer peripheral surface of the second semiconductor unit 403.

  The convex portion 408 is made of Si. The height H2 of the convex portion 408 is set to 1/10 or more of the wavelength of light emitted from the light emitting surface 404. The height H2 of the convex portion 408 may be set to 1/5 or more of the wavelength of light emitted from the light emitting surface 404.

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

First, as shown in FIG. 15A, a mask 412 having a plurality of growth holes 413, 413,... (Only two are shown in FIG. 15A) is formed on a substrate 411 made of Si. A material that can be selectively etched with respect to the first semiconductor portion 402 and the second semiconductor portion 403 such as silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ) is used for the mask 412. The growth holes 413, 413,... Can be formed by a known lithography method and dry etching method used in a normal semiconductor process.

Next, an n-type GaN crystal is grown on the substrate 411 exposed by the growth holes 413, 413,... Of the mask 412 by using an MOCVD apparatus, and as shown in FIG. A second semiconductor portion 403 is formed. More specifically, the temperature of the MOCVD apparatus is set to about 950 ° C., trimethyl gallium (TMG) and ammonia (NH ₃ ) are used as growth gases, silane (SiH ₃ ) is supplied for supplying n-type impurities, and carrier gas As a result, hydrogen (H ₃ ) is supplied to grow the second semiconductor portion 403 made of n-type GaN with Si as an impurity. At this time, the second semiconductor portion 403 is grown to almost half the depth of the growth hole 413 of the mask 412. Further, the diameter of the second semiconductor part 403 can be determined by the diameter of the growth hole 413 of the mask 412.

Next, a first semiconductor portion 402 made of p-type GaN is formed on each second semiconductor portion 403. More specifically, the temperature of the MOCVD apparatus is set to about 960 ° C., trimethylgallium (TMG) and ammonia (NH ₃ ) are used as growth gases, and biscyclopentadienylmagnesium (Cp ₂ Mg) is used to supply p-type impurities. By using it, p-type GaN having magnesium (Mg) as an impurity can be grown.

Next, the entire mask 412 is removed to obtain the state shown in FIG. 15C. In the case where the mask 412a is made of silicon oxide (SiO ₂ ) or silicon nitride (Si ₃ N ₄ ), the first semiconductor portion 402 and the second semiconductor portion 403A are used by using a solution containing hydrofluoric acid (HF). The entire mask 412 can be easily etched without affecting the above.

  Next, for example, isotropic etching is performed on the substrate 411 to obtain a substrate 411a shown in FIG. 15D. The substrate 411a has a connection portion having a diameter smaller than that of the second semiconductor portion 403, and the second semiconductor portion 403 is connected to the connection portion.

  Next, after immersing the substrate 411a in an isopropyl alcohol (IPA) aqueous solution, the substrate 411 is vibrated along the substrate plane using ultrasonic waves (for example, several tens of kHz). As a result, stress is applied to the connection portion of the substrate 411a, and most of the connection portion is separated from the substrate 411a together with the second semiconductor portion 403. That is, as shown in FIG. 15E, a plurality of main bodies 401, 401,... (Only two are shown in FIG. 15E) are separated from the substrate 411a.

  In this way, a fine rod-shaped structure light emitting device separated from the substrate 411 made of n-type GaN can be manufactured.

  According to the rod-shaped structure light emitting element having the above configuration, the light emitted from the light emitting surface 404 is directed to the one end surface 405 in the axial direction of the main body 401 by the waveguiding effect. Since the convex portion 408 is formed on the one end surface 405, the light from the light emitting surface 404 is axially one end surface of the main body 401 even in a micro rod-sized or nano-order sized light emitting element. Passes through 405 and goes out of the main body 401 efficiently.

  Therefore, it is possible to realize a fine rod-shaped structure light emitting element that can extract light efficiently. Since this rod-shaped structure light emitting element is not integrated with the substrate, the degree of freedom of mounting on the device is high.

  If the one end surface 405 in the axial direction of the main body 401 is flat, light from the light emitting surface 404 is reflected by the one end surface 405, so that almost no light is emitted outside the main body 401.

  Here, the fine rod-shaped structure light emitting element is, for example, a micro-order size having a diameter of 1 μm and a length of 10 μm, but is not limited to this size, and the diameter is 10 nm to 5 μm, more preferably 100 nm to 2 μm. You may manufacture a fine rod-shaped structure light emitting element. The length of this fine rod-shaped structure light emitting element is 100 nm to 200 μm, more preferably 1 μm to 50 μm.

  In addition, since the height H1 of the convex portion 408 is 1/10 or more of the wavelength of light emitted from the light emitting surface 404, the reflection of the light at the one end surface 405 where the convex portion 408 is formed is extremely reduced. Can do.

  In addition, since the material of the convex portion 408 is different from the material of the second semiconductor portion 403, the convex portion 408 is formed on one end surface 405 in the axial direction of the main body 401 without scraping the main body 401 or damaging the main body 401. Thus, reflection at the one end face 405 can be reduced.

  Further, when light is extracted from the rod-shaped structure light emitting element of the present embodiment, for example, as shown in FIG. 16A, the main body 401 is disposed on the surface of the insulating substrate 421. At this time, the main body 401 is arranged so that the axial direction of the main body 401 is substantially parallel to the surface of the insulating substrate 421. Note that the insulating substrate 421 is an example of a substrate.

  Next, as shown in FIG. 16B, the p-side contact metal 423 is connected to the first semiconductor portion 402 and the n-side contact metal 422 is connected to the second semiconductor portion 403 by, for example, vapor deposition or sputtering, and light emission is performed. Light is emitted from the light emitting surface 404 by flowing a current from the p-side contact metal 423 to the n-side contact metal 422 so that recombination of electrons and holes occurs on the surface 404.

  Thus, since the axial direction of the main body 401 is substantially parallel to the surface of the insulating substrate 421, the thickness can be reduced.

[Fifth Embodiment]
Next, the backlight, the illuminating device, and the display apparatus provided with the rod-shaped structure light emitting element of the fifth embodiment of the present invention will be described. In the fifth embodiment, the rod-shaped structure light emitting elements described in the first to fourth embodiments are arranged on an insulating substrate. The arrangement of the rod-shaped structure light-emitting elements is the same as that disclosed in Japanese Patent Application No. 2007-102848 (Japanese Patent Application Laid-Open No. 2008-260073), “Microstructure Arrangement Method, Substrate Arranged with Fine Structure, and Integrated Circuit Device” And display device ".

  FIG. 23 is a plan view of an insulating substrate used in the backlight, the illumination device, and the display device of the fifth embodiment. As shown in FIG. 23, metal electrodes 551 and 552 are formed on the surface of the insulating substrate 550. The insulating substrate 550 is an insulating material such as glass, ceramic, aluminum oxide, resin, or a substrate in which a silicon oxide film is formed on a semiconductor surface such as silicon and the surface is insulative. When a glass substrate is used, it is desirable to form a base insulating film such as a silicon oxide film or a silicon nitride film on the surface.

  The metal electrodes 551 and 552 are formed in a desired electrode shape using a printing technique. The metal film and the photosensitive film may be uniformly laminated, and a desired electrode pattern may be exposed and etched.

  Although not shown in FIG. 23, pads are formed on the metal electrodes 551 and 552 so that a potential can be applied from the outside. A rod-shaped structure light emitting element is arranged in a portion (array region) where the metal electrodes 551 and 552 face each other. In FIG. 23, 2 × 2 arrangement regions for arranging the rod-shaped structure light emitting elements are arranged, but any number may be arranged.

  18 is a schematic cross-sectional view taken along line XVIII-XVIII in FIG.

  First, as shown in FIG. 18, isopropyl alcohol (IPA) 561 including a rod-shaped structure light emitting element 560 is thinly applied on an insulating substrate 550. In addition to IPA 561, ethylene glycol, propylene glycol, methanol, ethanol, acetone, or a mixture thereof may be used. Alternatively, the IPA 561 can use a liquid made of another organic material, water, or the like.

  However, if a large current flows between the metal electrodes 551 and 552 through the liquid, a desired voltage difference cannot be applied between the metal electrodes 551 and 552. In such a case, the entire surface of the insulating substrate 550 may be coated with an insulating film of about 10 nm to 30 nm so as to cover the metal electrodes 551 and 552.

The thickness of applying the IPA 561 including the rod-shaped structure light emitting device 560 is such that the rod-shaped structure light emitting device 560 can move in the liquid so that the rod-shaped structure light emitting device 560 can be arranged in the next step of arranging the rod-shaped structure light emitting device 560. Is the thickness. Therefore, the thickness of applying the IPA 561 is equal to or greater than the thickness of the rod-shaped structure light emitting element 560, and is, for example, several μm to several mm. If the applied thickness is too thin, the rod-like structure light emitting element 560 is difficult to move, and if it is too thick, the time for drying the liquid becomes long. Further, the amount of the rod-shaped structure light emitting element 560 is preferably 1 × 10 ⁴ pieces / cm ³ to 1 × 10 ⁷ pieces / cm ³ with respect to the amount of IPA.

  In order to apply the IPA 561 including the rod-shaped structure light emitting element 560, a frame is formed on the outer periphery of the metal electrode on which the rod-shaped structure light emitting element 560 is arranged, and the IPA 561 including the rod-shaped structure light emitting element 560 is formed in the frame with a desired thickness. You may fill so that it may become. However, when the IPA 561 including the rod-like structure light emitting element 560 has viscosity, it can be applied to a desired thickness without the need for a frame.

  A liquid made of IPA, ethylene glycol, propylene glycol,..., Or a mixture thereof, or other organic substances, or a liquid such as water is desirable for the arrangement process of the rod-shaped structure light emitting device 560 to have a low viscosity. It is desirable that it evaporates easily when heated.

  Next, a potential difference is applied between the metal electrodes 551 and 552. In the fifth embodiment, it is appropriate to set the potential difference to 1V. The potential difference between the metal electrodes 551 and 552 can be 0.1 to 10 V. However, if the voltage difference is 0.1 V or less, the arrangement of the rod-like structure light emitting elements 560 is poor, and if it is 10 V or more, insulation between the metal electrodes becomes a problem. start. Therefore, it is preferably 1 to 5V, and more preferably about 1V.

FIG. 19 shows the principle in which the rod-shaped structure light emitting elements 560 are arranged on the metal electrodes 551 and 552. As shown in FIG. 19, when a potential V _L is applied to the metal electrode 551 and a potential V _R (V _L <V _R ) is applied to the metal electrode 552, a negative charge is induced in the metal electrode 551, and the metal electrode 552 A positive charge is induced in. When the rod-shaped structure light emitting element 560 approaches the positive electrode, a positive charge is induced on the side close to the metal electrode 551 and a negative charge is induced on the side close to the metal electrode 552. The charge is induced in the rod-like structure light emitting element 560 due to electrostatic induction. That is, the rod-shaped structure light emitting element 560 placed in the electric field is caused by the charge being induced on the surface until the internal electric field becomes zero. As a result, an attractive force is generated between each electrode and the bar-shaped structure light emitting element 560 by an electrostatic force, and the bar-shaped structure light emitting element 560 follows the electric lines of force generated between the metal electrodes 551 and 552, and each bar-shaped structure light emitting element 560. Since the charges induced in the are substantially equal, the repulsive force caused by the charges causes the charges to be regularly arranged in a fixed direction at almost equal intervals. However, for example, in the rod-shaped structure light emitting element shown in FIG. 1 of the first embodiment, the direction of the one end surface 5 on which the irregularities are formed is not constant, but is random (modified example of the first embodiment and other implementations). The same applies to the rod-shaped structure light emitting device of the form).

  As described above, the rod-like structure light emitting device 560 generates electric charges in the rod-like structure light emitting device 560 by the external electric field generated between the metal electrodes 551 and 552, and the metal electrodes 551 and 552 cause the rod-like structure light emitting device by attractive force. Since 560 is adsorbed, the size of the rod-shaped structure light emitting element 560 needs to be a size that can be moved in the liquid. Therefore, the size of the rod-shaped structure light emitting element 560 varies depending on the application amount (thickness) of the liquid. When the amount of applied liquid is small, the rod-like structure light emitting element 560 must have a nano-order size, but when the amount of applied liquid is large, it may be a micro-order size.

  When the rod-shaped structure light emitting element 560 is not electrically neutral but is charged positively or negatively, the rod-shaped structure light emitting element 560 is simply given a static potential difference (DC) between the metal electrodes 551 and 552. Cannot be stably arranged. For example, when the rod-shaped structure light emitting element 560 is positively charged as a net, the attractive force with the metal electrode 552 in which the positive charge is induced becomes relatively weak. Therefore, the arrangement of the rod-shaped structure light emitting elements 560 is not targeted.

In such a case, it is preferable to apply an AC voltage between the metal electrodes 551 and 552 as shown in FIG. In Figure 20, the reference potential to the metal electrodes 552, the metal electrode 551 is applied an AC voltage of amplitude _{V PPL} / 2. By doing so, even when the rod-shaped structure light emitting element 560 is charged, the arrangement can be kept as a target. In this case, the frequency of the AC voltage applied to the metal electrode 552 is preferably 10 Hz to 1 MHz, and more preferably 50 Hz to 1 kHz because the arrangement is most stable. Furthermore, the AC voltage applied between the metal electrodes 551 and 552 is not limited to a sine wave, but may be any voltage that varies periodically, such as a rectangular wave, a triangular wave, and a sawtooth wave. Note that V _PPL was preferably about 1V.

  Next, after arranging the rod-shaped structure light-emitting elements 560 on the metal electrodes 551 and 552, the insulating substrate 550 is heated to evaporate the liquid and dry, so that the rod-shaped structure light-emitting elements 560 are connected to the metal electrodes 551. , 552 are arranged at equal intervals along the electric lines of force between them and fixed.

  FIG. 21 is a plan view of an insulating substrate 550 on which the rod-shaped structure light emitting elements 560 are arranged. By using the insulating substrate 550 in which the rod-like structure light emitting elements 560 are arranged for a backlight of a liquid crystal display device or the like, it is possible to realize a backlight that can be reduced in thickness and weight, has high luminous efficiency, and saves power. it can. In addition, by using the insulating substrate 550 on which the rod-shaped structure light emitting elements 560 are arranged as a lighting device, it is possible to realize a lighting device that can be reduced in thickness and weight and has high luminous efficiency and power saving.

  FIG. 22 is a plan view of a display device using an insulating substrate on which the rod-shaped structure light emitting elements 560 are arranged. As shown in FIG. 22, the display device 500 includes a display portion 501, a logic circuit portion 502, a logic circuit portion 503, a logic circuit portion 504, and a logic circuit portion 505 on an insulating substrate 510. In the display portion 501, rod-shaped structure light emitting elements 560 are arranged in pixels arranged in a matrix.

  FIG. 23 shows a circuit diagram of a main part of the display unit 501 of the display device 500. The display unit 501 of the display device 500 has a plurality of scanning signal lines GL (see FIG. 23) intersecting each other as shown in FIG. 23, only one line is shown) and a plurality of data signal lines SL (only one line is shown in FIG. 23), and two adjacent scanning signal lines GL and two adjacent data signal lines SL are provided. Pixels are arranged in a matrix in a portion surrounded by. This pixel has a switching element Q1 having a gate connected to the scanning 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, and the switching element Q2. And a plurality of light emitting diodes D1 to Dn (rod-shaped structure light emitting element 560) driven by the switching element Q2.

  The pn polarities of the rod-shaped structure light emitting elements 560 are not aligned on one side, but are randomly arranged. For this reason, it is driven by an alternating voltage during driving, and the bar-shaped structured light emitting elements 560 having different polarities emit light alternately.

  In addition, according to the method for manufacturing the display device, the insulating substrate 550 in which the array region having the units of two electrodes 551 and 552 to which independent potentials are respectively applied is formed, and the insulating substrate 550 is formed on the insulating substrate 550. A liquid including the nano-order size or micro-order size rod-shaped structure light emitting element 560 is applied. Thereafter, independent voltages are applied to the two electrodes 551 and 552, respectively, so that the fine rod-shaped light emitting elements 560 are arranged at positions defined by the two electrodes 551 and 552. Thereby, the rod-shaped structure light emitting element 560 can be easily arranged on the predetermined insulating substrate 550.

  Moreover, in the manufacturing method of the display device, it is possible to manufacture a display device that can reduce the amount of semiconductor to be used and can be reduced in thickness and weight. In addition, the light emitting element 560 has a light emitting region that is widened by emitting light from the entire circumference of the semiconductor core covered with the semiconductor layer, so that a display device with high luminous efficiency and power saving can be realized. .

  In the first, third, and fourth embodiments, the first semiconductor portions 2, 62, 72, 302, and 402 and the second semiconductor portions 3, 63, 73, 303, and 403 are made of GaN as a base material. However, the present invention may be applied to a light emitting element using a semiconductor whose base material is GaAs, AlGaAs, GaAsP, InGaN, AlGaN, GaP, ZnSe, AlGaInP, or the like. Further, the present invention may be applied to a rod-shaped structure light emitting device in which the conductivity type of the first semiconductor portion is n-type and the conductivity type of the second semiconductor portion is p-type, and the conductivity type of the first semiconductor portion is p-type. The present invention may be applied to a rod-shaped structure light emitting device in which the conductivity type of the second semiconductor portion is n-type.

  In the first to fourth embodiments, the rod-shaped structure light emitting device including the main bodies 1, 61, 71, 201, 301, 401 having a substantially circular cross section has been described. However, the present invention is not limited thereto, and the rod shape of the present invention is used. The cross section of the main body of the structured light emitting element may be an ellipse or another polygonal shape such as a triangle.

  In the first to fourth embodiments, the diameter of the main body 1, 61, 71, 201, 301, 401 is preferably 500 nm or more and 50 μm or less, and the rod-shaped structure light emitting device including the main body having a diameter of several tens nm to several hundreds nm. As compared with the above, variation in diameter of the main bodies 1, 61, 71, 201, 301, 401 can be suppressed, variation in light emission area, that is, light emission characteristics can be reduced, and yield can be improved.

  In the first to fourth embodiments, the main bodies 1, 61, 71, 201, 301, 401 are similar to the axial end faces 5, 65, 75, 205, 305, 405. A concave portion or a convex portion may also be formed on the other end surface in the axial direction of 71, 201, 301, 401. That is, a rod-shaped structure light-emitting element including a main body having recesses or protrusions formed on both end faces in the axial direction may be used as the rod-shaped structure light-emitting element according to an embodiment of the present invention.

  In the manufacturing methods of the first to fourth embodiments, other crystal growth apparatuses such as an MBE (molecular beam epitaxial) apparatus may be used instead of the MOCVD apparatus. In addition, the first and second semiconductor parts were crystal-grown on the substrate using a mask having a growth hole. However, a metal seed was placed on the substrate, and the first and second semiconductor parts were grown from the metal seed. You may let them.

  Moreover, in the said 1st-4th embodiment, although the 1st, 2nd semiconductor part was cut off from the board | substrate using the ultrasonic wave, it is not restricted to this, The 1st, 2nd semiconductor part is used using a cutting tool. May be separated from the substrate by mechanical bending. In this case, a plurality of fine rod-shaped light emitting elements provided on the substrate can be separated in a short time by a simple method.

  In the fifth embodiment, a potential difference is given to the two metal electrodes 551 and 552 formed on the surface of the insulating substrate 550, and the rod-shaped structure light emitting elements 560 are arranged between the metal electrodes 551 and 552. Not limited to this, a third electrode is formed between two electrodes formed on the surface of the insulating substrate, and an independent voltage is applied to each of the three electrodes. You may arrange in the position.

  In the fifth embodiment, the display device including the rod-shaped structure light-emitting element has been described. However, the display device 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 You may apply to other apparatuses, such as an illuminating device.

  Further, in the second embodiment, a semiconductor using GaAs as a base material is used for the first semiconductor unit 202 and the second semiconductor unit 203, but AlGaAs, GaAsP, InGaN, AlGaN, GaP, ZnSe, AlGaInP, GaN, etc. The present invention may be applied to a light-emitting element using a semiconductor whose base material is. Further, the present invention may be applied to a rod-shaped structure light emitting device in which the conductivity type of the first semiconductor portion is n-type and the conductivity type of the second semiconductor portion is p-type, and the conductivity type of the first semiconductor portion is p-type. The present invention may be applied to a rod-shaped structure light emitting device in which the conductivity type of the second semiconductor portion is n-type.

  In the first and second embodiments, after separating the fine rod-shaped light emitting elements from the substrates 11 and 211, the axial directions of the main bodies 1, 61, 71 and 201 are arranged on the surfaces of the substrates 21 and 221. The fine bar-shaped light-emitting elements are arranged so as to be parallel to 221, and the n-side contact metal 22 and the p-side contact metal 23 are formed, but the fine bar-shaped light-emitting elements are separated from the substrates 11 and 211. Instead, a contact metal may be formed.

  Hereinafter, an example in the case where the contact metal is formed without separating the fine rod-shaped structure light emitting element from the substrate will be described.

  First, as shown in FIG. 24A, a substrate 1011 made of Si is prepared. If necessary, the substrate 1011 may be cleaned with a cleaning agent or pure water, or may be subjected to substrate processing such as marking.

  Next, ion implantation is performed on the substrate 1011 to form a base layer 1131 made of n-type Si on the surface portion of the substrate 1111 as shown in FIG. 24B.

  Next, as shown in FIG. 24C, a mask 1112 having a plurality of growth holes 1113, 1113,... (Only one is shown in FIG. 24C) is formed on the base layer 1131. As a material of the mask 1112, an insulator that can be selectively etched with respect to a second semiconductor portion 1103 </ b> A described later is used. The growth holes 1113, 1113,... Can be formed by a known lithography method and dry etching method used in a normal semiconductor process.

Next, an n-type GaN crystal is grown on the underlying layer 1131 exposed by the growth holes 1113, 1113,... Of the mask 1112 by using a MOCVD apparatus, and as shown in FIG. First semiconductor portion 1102 is formed. More specifically, the temperature of the MOCVD apparatus is set to about 950 ° C., trimethyl gallium (TMG) and ammonia (NH ₃ ) are used as growth gases, silane (SiH ₃ ) is supplied for supplying n-type impurities, and carrier gas As a result, hydrogen (H ₃ ) is supplied to grow the first semiconductor portion 1102 made of n-type GaN with Si as an impurity. The diameter of the first semiconductor portion 1102 can be determined by the diameter of the growth hole 1113 of the mask 1112.

Next, a second semiconductor portion 1103A made of p-type GaN is formed on each of the first semiconductor portions 1102. More specifically, the temperature of the MOCVD apparatus is set to about 960 ° C., trimethylgallium (TMG) and ammonia (NH ₃ ) are used as growth gases, and biscyclopentadienylmagnesium (Cp ₂ Mg) is used to supply p-type impurities. By using it, p-type GaN having magnesium (Mg) as an impurity can be grown.

  Next, planarization is performed by CMP (Chemical Mechanical Polishing) to make the surface of the mask 1112a substantially flush with the surface of the second semiconductor portion 1103A as shown in FIG. 24E.

  Next, as shown in FIG. 24F, a plurality of fine particles 1114 are formed on the mask 1112 and the second semiconductor portion 1103A. The diameter of the fine particles 1114 is about several tens of nanometers. For example, gold can be used as the material of the fine particles 1114.

  Next, dry etching is performed to form second semiconductor portions 1103 made of p-type GaN on each first semiconductor portion 1102 as shown in FIG. 24G. As a result, a plurality of fine rod-shaped structure light emitting elements that are not separated from the substrate 1111 are obtained. A rod-shaped main body 1101 having a substantially circular cross section of the fine rod-shaped structure light emitting element includes a first semiconductor portion 1102 and a second semiconductor portion 1103. The axial direction of the main body 1101 is substantially perpendicular to the surface of the substrate 1111. One concave portion is formed on one end surface 1105 in the axial direction of the main body 1101. Further, irregularities are formed on the surface of the mask 1112b. Note that unevenness may be formed on one end surface 1105 in the axial direction of the main body 1101. The first semiconductor unit 1102 is an example of a first conductivity type semiconductor, and the second semiconductor unit 1103 is an example of a second conductivity type semiconductor.

  Next, the surface portion of the mask 1112b is removed by wet etching, and the second semiconductor portion 1103 protrudes from the surface of the mask 1112c as shown in FIG. 24H. At this time, almost the entire outer peripheral surface of the second semiconductor portion 1103 is exposed. On the other hand, the outer peripheral surface of the first semiconductor unit 1102 is covered with the mask 1112c and part of it is not exposed.

  Next, as shown in FIG. 24I, a p-side contact metal 1132 is formed so as to cover the second semiconductor portion 1103 by vapor deposition or sputtering.

  Next, a part of the p-side contact metal 1132 is removed to obtain a p-side contact metal 1132a connected to the outer peripheral surface of the two semiconductor portions 1103 as shown in FIG. 24J. At this time, one end surface 1105 in the axial direction of the main body 1101 is not covered with the p-side contact metal 1132a and is exposed.

  Finally, although not shown, a part of the surface of the base layer 1131 is exposed and an n-side contact metal is connected to a part of this surface.

  By passing a current from the p-side contact metal 1132a thus formed to the n-side contact metal, light is emitted from the light emitting surface 1104. Then, light from the light emitting surface 1104 passes through one end surface 1105 in the axial direction of the main body 1101 and efficiently exits the main body 1101.

  Therefore, light can be extracted efficiently even with the fine rod-shaped structure light-emitting element erected on the substrate 1111.

  In the first to fourth embodiments, at least one of one end surface in the axial direction of the main body and the other end surface in the axial direction of the main body is formed of an electrode, and at least one of a concave portion and a convex portion is formed in the electrode. You may make it do. In this case, the electrode constitutes a part of the main body.

  Hereinafter, an example in which one end surface in the axial direction of the main body included in the fine rod-shaped structure light emitting element is formed of an electrode, and unevenness is formed on the electrode will be described.

  First, as shown in FIG. 25A, a substrate 2011 made of Si is prepared. If necessary, the substrate 2011 may be cleaned with a cleaning agent or pure water, or may be subjected to substrate processing such as marking.

  Next, ion implantation is performed on the substrate 2011 to form a base layer 2131 made of n-type Si on the surface portion of the substrate 2111 as shown in FIG. 25B.

  Next, as shown in FIG. 25C, a mask 2112 having a plurality of growth holes 2113, 2113,... (Only one is shown in FIG. 25C) is formed on the base layer 2131. As a material of the mask 2112, an insulator that can be selectively etched with respect to the base layer 2131 and a first semiconductor portion 2102 to be described later is used. The growth holes 2113, 2113,... Can be formed by a known lithography method and dry etching method used in a normal semiconductor process.

Next, an n-type GaN crystal is grown on the base layer 2131 exposed by the growth holes 2113, 2113,... Of the mask 2112 by using a MOCVD apparatus, and as shown in FIG. First semiconductor portion 2102 is formed. More specifically, the temperature of the MOCVD apparatus is set to about 950 ° C., trimethyl gallium (TMG) and ammonia (NH ₃ ) are used as growth gases, silane (SiH ₃ ) is supplied for supplying n-type impurities, and carrier gas As a result, hydrogen (H ₃ ) is supplied to grow the first semiconductor portion 2102 made of n-type GaN with Si as an impurity. The diameter of the first semiconductor portion 2102 can be determined by the diameter of the growth hole 2113 of the mask 2112.

  Next, the mask 2112 is selectively removed to expose the outer peripheral surface of the first semiconductor portion 2102 as shown in FIG. 25E.

Next, as shown in FIG. 25F, a second semiconductor portion 2103 made of p-type GaN is grown so as to cover the first semiconductor portion 2102. More specifically, the temperature of the MOCVD apparatus is set to about 960 ° C., trimethylgallium (TMG) and ammonia (NH ₃ ) are used as growth gases, and biscyclopentadienylmagnesium (Cp ₂ Mg) is used to supply p-type impurities. By using it, p-type GaN having magnesium (Mg) as an impurity can be grown.

  Next, as shown in FIG. 25G, a p-side contact metal 2132 made of ITO (tin-added indium oxide) is formed on the second semiconductor portion 2103. As a result, the second semiconductor portion 2103 is covered with the p-side contact metal 2132.

  Next, as shown in FIG. 25H, an insulating layer 2133 made of an oxide film is formed on the p-side contact metal 2132.

  Next, planarization is performed by CMP so that the surface of the insulating layer 2133a is substantially flush with the surface of the p-side contact metal 2132 as shown in FIG. 25I.

  Next, as illustrated in FIG. 25J, a plurality of fine particles 2114 are formed over the insulating layer 2133a and the p-side contact metal 2132. The diameter of the fine particles 2114 is about several tens of nanometers. As a material of the fine particles 2114, for example, gold can be used.

  Next, dry etching is performed to form irregularities on the surfaces of the insulating layer 2133a and the p-side contact metal 2132 as shown in FIG. 25K. Thereby, a plurality of fine rod-shaped structure light emitting elements formed integrally with the substrate 2111 are obtained. A rod-shaped main body 2101 having a substantially circular cross section of the fine rod-shaped structure light emitting element is composed of a first semiconductor portion 2102, a portion of the second semiconductor portion 2103, and a portion of the p-side contact metal 2132. The axial direction of the main body 2101 is substantially perpendicular to the surface of the substrate 2111. An unevenness is formed on one end surface 2105 in the axial direction of the main body 2101. Note that one concave portion or one convex portion may be formed on one end surface 2105 in the axial direction of the main body 2101. The first semiconductor portion 2102 is an example of a first conductivity type semiconductor, and the second semiconductor portion 2103 is an example of a second conductivity type semiconductor.

  Finally, although not shown, a part of the surface of the base layer 2131 is exposed and an n-side contact metal is connected to a part of this surface.

  By passing a current from the p-side contact metal 2132a formed in this way to the n-side contact metal, light is emitted from the light emitting surface 2104. Then, the light from the light emitting surface 2104 passes through one end surface 2105 in the axial direction of the main body 2101 and efficiently goes out of the main body 2101.

  Although specific embodiments of the present invention have been described, the present invention is not limited to the first to fifth embodiments, and can be implemented with various modifications within the scope of the present invention.

1, 61, 71, 201, 301, 401, 1101, 2101 Main body 2, 62, 72, 202, 302, 402, 1102, 2102 First semiconductor part 3, 63, 73, 203, 303, 403, 1103, 2103 Second semiconductor portion 5, 65, 75, 205, 305, 405, 1105, 2105 One end face in the axial direction 208, 408 Convex portion 309 Concavity H1, H2 Height D Depth 21, 221, 321, 421 Insulating substrate 500 Display device 560 Bar-shaped structure light emitting element

Claims (12)

It has a body that extends like a rod and generates light inside,
At least one of a recessed part and a convex part is formed in the end surface of the said main body in the axial direction, The rod-shaped structure light emitting element characterized by the above-mentioned. In the rod-shaped structure light emitting device according to claim 1,
The rod-shaped structure light emitting device, wherein the main body is disposed on a surface of a substrate, and an axial direction of the main body is substantially parallel to the surface of the substrate. The rod-shaped structure light emitting device according to claim 1 or 2,
The size of the concave portion or the convex portion is 1/10 or more of the wavelength of the light. In the rod-shaped structure light emitting device according to claim 3,
The size of the concave portion or the convex portion is 1/5 or more of the wavelength of the light. In the rod-shaped structure light emitting element according to any one of claims 1 to 4,
The material of the convex part is different from the material of the other part of the main body. In the rod-shaped structure light emitting element according to any one of claims 1 to 5,
The main body
A first conductivity type semiconductor;
A rod-shaped structure light emitting device having a second conductivity type semiconductor arranged in the axial direction of the main body with respect to the first conductivity type semiconductor. The rod-shaped structure light emitting device according to claim 6,
A rod-shaped structure light emitting device, wherein a quantum well layer is formed between the first conductive semiconductor and the second conductive semiconductor. In the rod-shaped structure light emitting element according to any one of claims 1 to 5,
The main body
A first conductivity type semiconductor;
A rod-shaped structure light emitting device comprising: a second conductivity type semiconductor concentrically covering at least a part of the first conductivity type semiconductor. The rod-shaped structure light emitting device according to claim 8,
A rod-shaped structure light emitting device, wherein a quantum well layer is formed between the first conductive semiconductor and the second conductive semiconductor.   A backlight comprising the rod-shaped structure light emitting device according to claim 1.   An illuminating device comprising the rod-shaped structure light emitting element according to any one of claims 1 to 9.   A display device comprising the rod-shaped structure light emitting element according to claim 1.

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