JP2004336078A - Display device and semiconductor light emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device that has a structure suited for multi-color without largely increasing manufacturing steps, and a semiconductor light emitting device. <P>SOLUTION: The display device has a plurality of semiconductor light emitting devices 11R, 11B, and 11G arranged in it, and these semiconductor light emitting devices 11R, 11B, and 11G are formed together with dummy devices 12R, 13B, and 14G. Further, each of these semiconductor light emitting devices 11R, 11B, and 11G is grown in a selective way, so that one conductive layer is formed in a self-adjusting way on a plane that has grown an inclined plane. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a display device using a semiconductor light emitting device, and more particularly to a display device and a semiconductor light emitting device formed using a wurtzite type compound semiconductor layer such as a GaN-based semiconductor layer.

  As a semiconductor light emitting device, a low-temperature buffer layer and an n-side contact layer made of Si-doped GaN are formed on the entire surface of a sapphire substrate, and an n-side clad layer made of Si-doped GaN and a Si-doped layer are formed thereon. An element in which an active layer made of InGaN, a p-side cladding layer made of Mg-doped AlGaN, a p-side contact layer made of Mg-doped GaN, and the like are known. Commercially available products having such a structure, blue and green light emitting diodes (Light Emitting Diode) including 450 nm to 530 nm and semiconductor lasers are mass-produced.

  Further, when growing gallium nitride, a sapphire substrate is often used. However, due to lattice mismatch between the sapphire substrate and the gallium nitride to be grown, high-density dislocations may be present in the crystal. For this reason, the technique of forming a low-temperature buffer layer on a substrate is one means for suppressing defects generated in a crystal to be grown, and Japanese Patent Application Laid-Open No. 10-312971 discloses a technique for reducing crystal defects. It combines selective lateral crystal growth (ELO: epitaxial lateral overgrowth). Furthermore, in the method for manufacturing a semiconductor light emitting device described in JP-A-10-312971, threading dislocations extending perpendicular to the main surface of the substrate are laterally bent by a facet structure formed in a growth region during manufacturing. It is described that crystal defects can be reduced by making it impossible to extend as it is.

  In addition, an image display device can be configured by configuring each pixel by combining light-emitting diodes or semiconductor lasers of each color of blue, green, and red, and arranging each pixel in a matrix and driving independently. In addition, the light-emitting elements of blue, green, and red can emit light simultaneously to be used as a white light-emitting device or a lighting device. In particular, a light-emitting element using a nitride semiconductor has a band gap energy of about 1.9 eV to about 6.2 eV, and a full-color display can be realized with one material. .

  Conventionally, as a technique for forming a multicolor light-emitting element on the same substrate, a plurality of active layers having different band gap energies are laminated according to the emission wavelength, and the other electrode is made common while using the same electrode on the substrate side. There is known an element in which is formed separately for each color, and an element having a structure in which each step on a substrate surface formed in a step-like shape for taking out an electrode corresponds to each color. However, in such an element in which a plurality of pn junctions are stacked, the light-emitting element may operate like a thyristor in the same element. As described above, there is also known an element in which a groove is formed for each stepped portion to separate each color.

Further, in the light emitting device disclosed in Japanese Patent Application Laid-Open No. 9-98881, an InGaN layer is formed on an alumina substrate via an AlN buffer layer for multicolor light emission, and a part of the InGaN layer is formed of AlGaN. Is doped to emit blue light, and the other part is doped with P to emit red light, and the non-doped region of the InGaN layer is multicolored as a green light emitting region.

  First, in order to reduce threading dislocations from the substrate, in a technique for performing selective crystal growth in the lateral direction and a crystal growth method for forming a facet structure in a growth region, threading dislocations from the substrate are laterally oriented by a facet structure portion or the like. And the number of crystal defects can be greatly reduced. However, in order to form a light emitting region such as an active layer after that, a selective crystal growth in the lateral direction is sufficiently performed or a facet structure is buried. The problem is that the time required for the process becomes longer.

  In addition, in the case of a semiconductor light emitting device which has achieved multi-color as described above, the manufacturing process is complicated, the light emitting device cannot be formed with high accuracy, and the crystallinity is deteriorated. I can't get it. That is, in a device in which a groove is formed for each stepped portion for each color and separated for each color, a plurality of anisotropic etchings are required to isolate the regions of each active layer. The crystallinity of the substrate or the semiconductor layer may be degraded by dry etching, and it is difficult to maintain good crystallinity.

Further, when etching is performed a plurality of times, the number of steps such as mask alignment and etching also increases accordingly. In a light emitting element in which a single active layer formed on a substrate is selectively doped with an impurity, a margin for forming an opening in a mask layer is required. It is necessary to keep a sufficient distance between the color regions, it is difficult to form a minute light emitting element, and the number of steps increases due to selective doping.

  On the other hand, a method of forming a nitride-based semiconductor such as GaN in a pyramid shape by selective growth is known as a method of forming an element in a fine region. In particular, a method of forming a hexagonal pyramid-shaped nitride-based semiconductor by selective growth is known. As a method for forming a light emitting device, for example, there is a method described in "Spatial control of InGaN luminescence by MOCVD selective epitaxy" D. Kapolnek et al., Journal of Crystal Growth 189/190 (1998) 83-86. In the selective growth described in this document, a plurality of nitride-based semiconductor light-emitting devices made of GaN / InGaN having a small hexagonal pyramid shape can be formed. In the process disclosed in the above document, it is described that the emission wavelength is controlled in accordance with a spatial factor. However, specific means for manufacturing light-emitting elements of different emission colors for multicoloring, and configuring an image display device by arranging elements of different emission colors, for example, elements of red, green, and blue emission colors. Is not listed.

  In view of the above technical problems, an object of the present invention is to provide a display device and a semiconductor light emitting element having a structure suitable for multicoloring without increasing the number of manufacturing steps.

  The display device of the present invention is characterized in that the semiconductor light-emitting element constituting the display device is formed together with a dummy element for determining an emission wavelength. The dummy elements are illustratively disposed around each of the semiconductor light emitting elements, are formed by the same manufacturing process, or can be configured to change the emission wavelength according to the distance between the semiconductor light emitting elements. .

  According to still another display device of the present invention, at least two types of semiconductor light emitting elements having different emission wavelengths are formed on the same substrate by the same crystal growth layer, and the electrode on the substrate side is a common electrode. It is characterized by. By forming at least two types of light-emitting elements on the same base with the same crystal growth layer, elements with different emission wavelengths can be formed on the same base by the same crystal growth process. In order to make the emission wavelengths different between the semiconductor light emitting elements, for example, the positional relationship between the semiconductor light emitting elements and the dummy elements or the shape of the semiconductor light emitting elements can be selected.

  Still another display device according to the present invention is characterized in that an inter-device region between a plurality of semiconductor light-emitting devices arranged on a base has a light transmitting region. This light transmitting region is a region through which light from the rear surface can be transmitted. By forming such a light transmitting region, even when a display device in which the substrates are overlapped with each other is formed, the light transmitting region is formed on the rear substrate side. Light from the semiconductor light emitting element can be led out to the front side through the light transmitting region.

  Further, the semiconductor light emitting device of the present invention is characterized by being formed around a dummy device having the same structure. By forming such a dummy element around the semiconductor light-emitting element, the emission wavelength can be changed while having the same structure, and multi-color display can be performed when a display device is configured using a plurality of light-emitting elements. .

  As described above, according to the display device of the present invention, since the emission wavelength is controlled by the dummy element, elements having a plurality of emission wavelengths can be formed in the same manufacturing process on the same base. In addition, a large-screen, high-resolution, full-color display device can be realized by arranging and forming elements on different substrates for each emission wavelength and overlapping the substrates in the light irradiation direction.

  The display device according to the present invention is configured by arranging a plurality of semiconductor light emitting elements on a base, and is formed together with a dummy element for setting an emission wavelength, and each of the semiconductor light emitting elements is selectively grown. It has a structure in which at least the periphery is formed on a surface on which an inclined surface that is formed and is inclined with respect to the main surface of the base is grown, and one conductive layer is formed in a self-aligned manner on the surface on which the inclined surface is grown. It is characterized by being performed.

First, each semiconductor light-emitting element that constitutes the display device of the present invention will be described. First, the substrate used for the configuration of the semiconductor light emitting device is not particularly limited as long as it can form a wurtzite compound semiconductor layer, and various substrates can be used. For example, sapphire (including Al ₂ O ₃ , A-plane, R-plane, and C-plane), SiC (including 6H, 4H, and 3C), GaN, Si, ZnS, A substrate made of ZnO, AlN, LiMgO, LiGaO ₂ , GaAs, MgAl ₂ O ₄ , InAlGaN, or the like, preferably a hexagonal substrate or a cubic substrate made of these materials, and more preferably a hexagonal substrate It is a substrate. For example, in the case of using a sapphire substrate, a sapphire substrate having a C-plane as a main surface, which is widely used when growing a gallium nitride (GaN) -based compound semiconductor material, can be used. In this case, the C plane as the main surface of the substrate includes a plane orientation inclined in the range of 5 to 6 degrees. A semiconductor substrate formed on a silicon substrate widely used in the manufacture of semiconductor devices may have a structure having an inclined surface.

A compound semiconductor layer can be formed on the main surface of the substrate. This compound semiconductor layer is preferably a wurtzite compound semiconductor because a facet structure is formed in a later step. Further, as the compound semiconductor layer, a nitride semiconductor having a wurtzite crystal structure, a BeMgZnCdS-based compound semiconductor, a BeMgZnCdO-based compound semiconductor, or the like is preferable. As the crystal layer composed of a nitride semiconductor, for example, a group III compound semiconductor can be used, and further, a gallium nitride (GaN) compound semiconductor, an aluminum nitride (AlN) compound semiconductor, and an indium nitride (InN) compound semiconductor Indium gallium nitride (InGaN) -based compound semiconductors and aluminum gallium nitride (AlGaN) -based compound semiconductors can be preferably formed, and gallium nitride-based compound semiconductors are particularly preferable. As an example, an undoped GaN layer may be formed on a sapphire substrate, and then a Si-doped GaN layer may be formed. In the present invention, InGaN, AlGaN, GaN, and the like do not necessarily refer to a nitride semiconductor consisting of only a ternary mixed crystal and only a binary mixed crystal. For example, in InGaN, a trace amount within a range that does not change the action of InGaN. It is needless to say that the present invention includes Al and other impurities. The plane substantially equivalent to the S plane includes a plane orientation inclined at 5 to 6 degrees with respect to the S plane. Here, in this specification, a nitride refers to a compound in which B, Al, Ga, In, and Ta are group III and N is included in group V, and is an impurity within 1% or 1 × 10 ²⁰ cm ³ or less of the whole. In some cases.

  As a method for growing the compound semiconductor layer, various vapor phase growth methods can be mentioned, for example, vapor phase growth methods such as metalorganic compound vapor phase growth method (MOCVD (MOVPE) method) and molecular beam epitaxy method (MBE method). A growth method or a hydride vapor phase epitaxy method (HVPE method) can be used. Among them, according to the MOVPE method, a material having good crystallinity can be obtained quickly. In the MOVPE method, TMG (trimethylgallium) and TEG (triethylgallium) are used as a Ga source, TMA (trimethylaluminum) and TEA (triethylaluminum) are used as an Al source, and TMI (trimethylindium) and TEI (triethylindium) are used as an In source. ) Are often used, and a gas such as ammonia or hydrazine is used as a nitrogen source. As an impurity source, a gas such as silane gas for Si, germane gas for Ge, Cp2Mg (cyclopentadienyl magnesium) for Mg, and DEZ (diethyl zinc) for Zn is used. In the MOVPE method, these gases are supplied to the surface of the substrate heated to, for example, 600 ° C. or more, and the gases are decomposed, whereby the InAlGaN-based compound semiconductor can be epitaxially grown.

  In the semiconductor light emitting device of the present invention, since a facet structure having an inclined surface inclined with respect to the main surface of the base is formed by crystal growth, a mask or a step is formed on the surface of the compound semiconductor layer underlying the crystal growth. It is formed. The mask is a growth inhibition film formed directly on the main surface of the base or on a buffer layer or other layers formed on the base. For example, a mask material made of an insulating film such as a silicon oxide film or a silicon nitride film is used. You. In the case of forming a facet structure using a step, a crystal plane appearing on the substrate, for example, a crystal plane perpendicular to the main surface of the substrate is grown at a different growth rate from a crystal plane parallel to the main surface of the other substrate. As a result, a facet structure can be formed. The step can be formed by photolithography and anisotropic etching after forming a compound semiconductor layer over the entire surface, and a mask material such as a silicon oxide layer or a silicon nitride layer may be used. The shape of the mask or the step is not particularly limited as long as it can be a facet structure having an inclined surface inclined with respect to the main surface of the substrate. , Triangular, pentagonal or hexagonal. The shape of the step refers to a planar shape of a part having a height difference. It shall include both of them. The region where the step is formed may be the entire surface of the compound semiconductor layer or only a part thereof. Further, steps having different shapes may be formed in combination.

  After such a selective growth mask or the like is formed, a crystal growth layer having a facet structure having an inclined surface is formed by selective crystal growth. The crystal growth can be performed by the same method as the method for forming the compound semiconductor layer described above. Specifically, examples of the growth method include various vapor phase growth methods. A growth method or a hydride vapor phase epitaxy method (HVPE method) can be used.

  In the semiconductor light emitting device according to the present invention, when a crystal growth layer having a facet structure is formed by crystal growth, the S plane and the {11-22} plane or the {11-22} plane or these planes are inclined with respect to the main surface of the base. It is desirable that each surface has a surface selected from substantially equivalent surfaces. For example, when the main surface of the base is the C-plane, the S-plane or a plane substantially equivalent to the S-plane can be easily formed. The S plane is a stable plane that can be seen when selectively grown on the C + plane, is a relatively easy to obtain plane, and has a hexagonal plane index of (1-101). Similar to the C + plane and the C− plane existing on the C plane, the S plane has the S + plane and the S− plane. However, in this specification, unless otherwise specified, the S + plane is on the C + plane GaN. The surface is growing, and this is described as the S surface. The S + plane is a stable plane for the S plane. The plane index of the C + plane is (0001).

  In the case of forming a crystal layer using a gallium nitride-based compound semiconductor on the S plane, the number of bonds from Ga to N on the S plane is 2 or 3, which is the second largest after the C-plane. Here, since the C- plane cannot be obtained on the C + plane, the number of bonds on the S plane is the largest. For example, when a nitride is grown on a sapphire substrate having a C + plane as a main surface, the surface of the wurtzite-type nitride generally becomes a C + plane, but the S plane is formed stably by using selective growth. In the plane parallel to the C + plane, an N bond, which tends to detach easily, is bonded with one bond from Ga, while on the inclined S plane, it is bonded with at least one bond. Will be. Therefore, the V / III ratio is effectively increased, which is advantageous for improving the crystallinity of the laminated structure. Further, when the crystal is grown in a direction different from that of the substrate, dislocations extending upward from the substrate may be bent, which is advantageous in reducing defects.

  The inclined facet structure of the crystal growth layer can be controlled by the shape of the mask, the growth conditions during crystal growth, and the step shape. For example, assuming that a step portion extending in a stripe shape is formed on the surface of the gallium nitride-based semiconductor layer, if the longitudinal direction of the stripe is the (11-20) direction, the S plane is an inclined surface. The facet structure is formed such that the cross section of a plane perpendicular to the longitudinal direction of the stripe has an inverted V shape. Here, since the shape of the step is not limited to the stripe shape, the inverted V-shaped cross section of the crystal growth layer appears in various shapes. The shape of the crystal growth layer is, for example, a stripe, a rectangle, a circle, a triangle, or a hexagon. The crystal growth layer is grown reflecting the shape of the step, and the extending direction of the end of the step is set substantially perpendicular to the (1-100) direction or substantially perpendicular to the (11-20) direction. A speed difference between the lateral growth and the vertical growth is obtained, and a facet structure is obtained.

  In the crystal growth layer having such a facet structure, a first conductivity type clad layer, an active layer, and a second conductivity type clad layer are stacked in a region extending in parallel with the inclined plane. In an experiment performed by the present inventors on a nitride semiconductor, the grown facet structure was observed by using cathodoluminescence. Is shown to be higher. In particular, the growth temperature of the InGaN active layer is, for example, 700 to 800 ° C. At this temperature, the decomposition efficiency of ammonia is low, and more N species are required. In addition, when the surface was viewed by AFM, a step suitable for InGaN incorporation was observed with uniform steps. In addition, the growth surface of the Mg-doped layer generally has a poor surface condition at the AFM level, but it has been found that the Mg-doped layer grows in a good surface condition due to the growth of the S-plane, and that the doping conditions are considerably different. . Further, when microphotoluminescence mapping is performed, measurement can be performed with a resolution of about 0.5-1 μm. However, in the ordinary method grown on the C + plane, unevenness of about 1 μm pitch exists, and the selective growth is difficult. A uniform result was obtained for the sample having the S surface. Also, the flatness of the slope as viewed by SEM is smoother than the C + plane.

  In the first conductivity type cladding layer, the active layer, and the second conductivity type cladding layer formed in a region extending in parallel with the inclined surface, the first conductivity type is p-type or n-type, and the second conductivity type is Is the opposite conductivity type. For example, when the crystal layer forming the S plane is formed of a silicon-doped gallium nitride compound semiconductor layer, the n-type cladding layer is formed of a silicon-doped gallium nitride compound semiconductor layer, and an InGaN layer is formed thereon. And a magnesium-doped gallium nitride-based compound semiconductor layer is further formed thereon as a p-type cladding layer to form a double hetero structure. It is also possible to adopt a structure in which an InGaN layer as an active layer is sandwiched between AlGaN layers, or a structure in which an AlGaN layer is formed only on one side. The active layer can be constituted by a single bulk active layer. However, a quantum well such as a single quantum well (SQW) structure, a double quantum well (DQW) structure, and a multiple quantum well (MQW) structure can be used. It may have a structure. In the quantum well structure, a barrier layer is used in combination for separating the quantum wells as necessary. When the active layer is an InGaN layer, the structure is easy to manufacture, especially in the manufacturing process, and the light emitting characteristics of the device can be improved. Furthermore, this InGaN layer is particularly easy to crystallize and grows in crystallinity particularly when grown on the S-plane, which has a structure in which nitrogen atoms are not easily desorbed, so that luminous efficiency can be increased. It should be noted that the nitride semiconductor has an n-type property due to nitrogen vacancies formed in the crystal even when it is non-doped. However, by doping a donor impurity such as Si, Ge, or Se during crystal growth, the carrier concentration can be reduced. It can be a preferred n-type. The nitride semiconductor can be made p-type by doping the crystal with an acceptor impurity such as Mg, Zn, C, Be, Ca, or Ba. In order to obtain a p-layer having a high carrier concentration, It is preferable to perform annealing at 400 ° C. or higher in an inert gas atmosphere such as nitrogen or argon after doping with an acceptor impurity, and there is also a method of activating by electron beam irradiation, etc. There is also a way to convert.

  The first conductive type clad layer, the active layer, and the second conductive type clad layer extend in a plane parallel to the inclined plane. If the crystal is continuously grown where the surface is formed, it can be easily performed. The first conductivity type cladding layer can be made of the same material and of the same conductivity type as the crystal layer constituting the S plane, and is formed while continuously adjusting the concentration after forming the crystal layer constituting the S plane. Alternatively, as another example, a structure in which a part of the crystal layer constituting the S plane functions as a first conductivity type cladding layer may be used.

  Electrodes are directly or indirectly connected to the first conductivity type clad layer and the second conductivity type clad layer sandwiching the active layer. Each electrode is formed for each element, but one of the p-electrode and the n-electrode can be shared. In order to reduce the contact resistance, a contact layer may be formed, and then an electrode may be formed on the contact layer. Generally, each electrode is formed by depositing a multi-layered metal film by vapor deposition or the like, but can be finely processed by lift-off or the like using photolithography in order to classify each element. Each electrode may be formed on one surface of the selective crystal growth layer or the substrate, or electrodes may be formed on both sides to wire the electrodes at a higher density. The independently driven electrodes may be formed by finely processing the same material, but it is also possible to use a different electrode material for each region.

  In the semiconductor light emitting device according to the present invention, luminous efficiency can be enhanced by utilizing the good crystallinity of the inclined surface formed by crystal growth. In particular, when a group III nitride-based semiconductor is used and a current is injected only to the S-plane having good crystallinity, the S-plane has good incorporation of In and good crystallinity, so that the luminous efficiency can be increased. Further, in order to achieve multicolor using an InGaN active layer, it is necessary to sufficiently capture In as a crystal, and it is possible to enhance luminous efficiency by utilizing good crystallinity of the S-plane, and to improve multicolor. This is a desirable structure for light emission. That is, only one N bond, which is considered to be easily desorbed from Ga as long as it grows on the C + plane, comes out from Ga, and the effective V / III ratio is as long as it grows using ammonia with low decomposition efficiency. Cannot be made large, and many contrivances are required to achieve high quality crystal growth. However, in the growth on the S-plane, N bonds are connected to Ga by two or three bonds, so that N tends to be hardly desorbed, and the effective V / III ratio is considered to be high. Can be This is not limited to the S-plane growth, but the growth of the growth without the C + plane can all be said to lead to higher quality because the number of bonds from Ga to N tends to increase in all growths other than the C + plane. . In addition, the amount of In incorporated into the crystal becomes substantially large. When the amount of In taken in is increased in this way, the bandgap energy is controlled by the amount of In taken, so that it is suitable for multicoloring.

  In one example of the semiconductor light-emitting device according to the present invention, the semiconductor light-emitting device has an element structure in which at least the periphery is surrounded by an inclined surface of a facet structure formed by selective growth, and one conductive layer is formed on a surface on which the inclined surface is grown. It is formed in a self-aligned manner. That is, since the periphery of the element is surrounded by the inclined surface of the facet structure, the conductive layer is formed in a shape inclined with respect to the main surface of the base, but the conductive layer is formed at the mask or step used for selective growth. Ends, and the conductive layer of each individual element is formed in conformity only with the inclined surface. For example, in an element structure in which a first conductivity type clad layer, an active layer, and a second conductivity type clad layer are sequentially formed from the base side, one conductive layer in which the second conductivity type clad layer is formed in a self-aligned manner is used. Constitute. Therefore, it is not necessary to separate one conductive layer by etching or the like for each element, so that elements can be arranged at a high density.

  In the semiconductor light emitting device according to the present invention, it is possible to control the emission wavelength by disposing a required dummy element as described later, but at least one of the composition and the thickness of the active layer between the light emitting regions. Can be set differently. That is, only the composition of the active layer may be different, only the thickness of the active layer may be different, or both the composition and the thickness of the active layer may be different. These methods of changing the composition and thickness of the active layer can be used in combination with a dummy element as described later, or may be caused by the dummy element. The layer composition of the semiconductor light emitting device can be changed by changing the mixed crystal ratio of the ternary mixed crystal and the binary mixed crystal constituting the active layer in the same active layer. In this case, by increasing the amount of In contained in the active layer, a semiconductor light emitting device having a longer wavelength can be formed. For example, in the crystal growth of an InGaN layer, the migration length of InGaN, particularly In, is estimated to be about 1 to 2 μm at about 700 ° C., which is almost optimal for the crystal growth of an InGaN layer having a relatively large In composition. This is because InGaN deposited on the mask grows only about 1 to 2 μm from the selectively grown portion. From this, it is considered that the migration length of In is as large as above. Since the migration length of In or the like in InGaN from the mask portion to the growth portion is relatively short, the composition of In or the InGaN in the surface is relatively short. The thickness may be different.

  Further, in an example of the semiconductor light emitting device according to the present invention, it is possible to control the layout of the dummy device as described later, but as another method for changing the emission wavelength, the shape of the mask opening for selective growth is changed. Thus, the shape of the light emitting element can be changed, and the emission wavelength can be changed accordingly. For example, a semiconductor light emitting device having a second light emission wavelength different from the first light emission wavelength in the form of a band or stripe is formed in parallel with the formation of the semiconductor light emitting device having the first light emission wavelength by selectively growing from a circular or regular hexagonal opening. May be formed. These methods of changing the shape of the mask opening for selective growth can be used in combination with a dummy element as described later. As an example, when a facet structure having an S-plane inclined surface is formed by selective growth after forming a stripe-shaped mask, the light-emitting region formed on the inclined surface has a long wavelength and is formed on the C-plane. The light emitting region can have a short wavelength. The reverse is also possible depending on the growth conditions.

  In particular, in one example of the semiconductor light emitting device according to the present invention, a dummy element can be formed together with the semiconductor light emitting device. The dummy element is an element formed on the same base by substantially the same manufacturing method, and is disposed around the semiconductor light emitting element to set a spacing factor of the semiconductor light emitting element. As described above, when a semiconductor light emitting device made of a hexagonal pyramid-shaped nitride semiconductor is formed by selective growth, for example, "Spatial control of InGaN luminescence by MOCVD selective epitaxy" D. Kapolnek et al., Journal of Crystal As described in Growth 189/190 (1998) 83-86, since the emission wavelength is controlled according to the space factor, it is necessary to positively and reliably control the emission wavelength by disposing a dummy element. Can be.

  Here, the dummy element will be further described. A layout in which a plurality of pyramid-shaped dummy elements are arranged at equal intervals around the semiconductor light emitting element to emit light, or a closed loop shape surrounding the periphery around the semiconductor light emitting element to emit light Such a layout may be used, a combination of a long rectangular or arc-shaped dummy element and a hexagonal pyramid-shaped dummy element or a multi-circle array may be used, and the layout is not limited thereto. Other element shapes and layouts that can control the space factor may be used. The number of semiconductor light-emitting elements disposed adjacent to the dummy element is not limited to one, and a layout in which a plurality of semiconductor light-emitting elements are present collectively may be used. The layer structure does not need to be strictly identical between the dummy element and the semiconductor light emitting element that emits light, and the thickness, composition material, impurity concentration, etc. of each layer may be identical or may be different. good. Further, a layer or an impurity may be added only to the dummy element. The space factor may be controlled by forming a layer at a height different from that of the semiconductor light emitting element by a method such as forming a step on the substrate only at the dummy element. When the structure of the dummy element matches the structure of the semiconductor light emitting element to emit light, there is an advantage that the semiconductor element can be manufactured in the same process. The distance between the dummy element and the semiconductor light emitting element that emits light is one of the space factors, and the emission wavelength can be controlled by controlling the distance. Further, the shape of the semiconductor light emitting element itself can be used for controlling the emission wavelength as described above.

  For example, when the arrangement of the dummy elements is changed to form a red light-emitting semiconductor light-emitting element, a blue light-emitting semiconductor light-emitting element, and a green light-emitting semiconductor light-emitting element, over a slightly larger size (for example, a diameter of 40 μm). When a semiconductor light emitting element and a dummy element are formed around the semiconductor light emitting element, the semiconductor light emitting element can emit red light, and the dummy light emitting element is formed around the semiconductor light emitting element and the surrounding area over a slightly smaller size (for example, a diameter of 20 μm). In this case, the semiconductor light emitting element is capable of emitting green light, and if a dummy element is arranged in a slightly larger size for red light emission, but the shape of the semiconductor light emitting element in the center is made into an elongated rectangular shape, blue light emission is possible. It becomes.

  Next, the display device of the present invention will be described. The display device according to the present invention has a structure in which a plurality of semiconductor light-emitting elements are arranged. In particular, semiconductor light-emitting elements having different emission wavelengths can be arranged on the same substrate (substrate) to achieve multicolor. A light emitting element can be provided on each substrate (substrate) for each emission wavelength, and the substrates can be overlapped to achieve multicolor.

  When arranging semiconductor light emitting elements of different emission wavelengths on the same substrate to achieve multicolor, it is difficult to form semiconductor light emitting elements of three colors on the same substrate. In order to manufacture a semiconductor device, semiconductor light-emitting elements grown on separate substrates for each color are arranged and mounted in a matrix on another substrate. Further, even if the semiconductor light emitting elements of three colors can be manufactured on the same substrate by using the above method, the substrate on which each semiconductor light emitting element is grown is only about 5 inches at the maximum. It is necessary to mount a plurality of semiconductor light emitting elements on another substrate in order to use the same.

  Generally, it is very difficult to mount a semiconductor light emitting element at a high density while maintaining a precise positional relationship. This is because, for example, misalignment is likely to occur due to the influence of heat generated when a previously mounted element is mounted later when an adjacent element is mounted. As the distance between the light-emitting elements is reduced to realize a high-resolution image display device, the problem of the displacement is more likely to occur. In addition, semiconductor light-emitting elements of each color tend to have a nonuniform finished height. The uneven height may cause a defect in a process such as photolithography for providing wiring for supplying power to the semiconductor light emitting device.

  Therefore, for example, when a full-color image display device is configured by aligning red light-emitting elements, blue light-emitting elements, and green light-emitting elements as semiconductor light-emitting elements, only a substrate on which only red light-emitting elements are arranged and only a blue light-emitting element are used. A full-color image is obtained by overlapping the arrayed substrate and the substrate on which only the green light emitting elements are arrayed in the light irradiation direction, and allowing the light from the light emitting elements located on the back surface to pass through the light transmission area. Can be displayed. At this time, it is preferable that the semiconductor light emitting elements have a structure in which they do not overlap in the light irradiation direction, and even if wirings for supplying power or signals to the semiconductor light emitting elements overlap in the light irradiation direction. good. When the semiconductor light emitting elements overlap in the irradiation direction, the emission colors are mixed and a desired image cannot be formed. Therefore, it is preferable that the semiconductor light emitting elements have a structure that does not overlap in the light irradiation direction. The inter-device region between the plurality of semiconductor light emitting devices may have a light transmission region of at least 1 μm or more. If the distance is less than 1 μm, the outgoing light from the semiconductor light emitting element formed on the back side substrate is out of the light transmitting region in consideration of the distance between the substrates and the spread of the beam among the overlapping substrates. This is because the light is reflected and the illuminance is reduced. In addition, when a metal thin film is used as a wiring material to reduce resistance, it is conceivable that light does not pass through the wiring portion. However, wiring for supplying power or a signal to the semiconductor light emitting element may be in the light irradiation direction. In the case of the overlapping structure, the regions that do not transmit light are overlapped with each other, so that the light transmittance can be maintained satisfactorily, and the degree of freedom of element arrangement can be increased. That is, a region that does not transmit light between the superposed substrates can be effectively used as a space for disposing various circuit units such as a driver (driving element), and contributes to miniaturization and high integration of the entire device. . In addition, by arranging the semiconductor light emitting elements on separate substrates for each color and superimposing them, a three-dimensional arrangement is possible, the distance between the elements at the time of manufacturing is widened, and a display device with high resolution is manufactured. In this case, the problem of misalignment hardly occurs. Furthermore, by arranging each element on a separate substrate for each color, a defect in a process such as wiring in a subsequent process that occurs due to unevenness in the finished height of the semiconductor light emitting element for each color, Can be avoided.

  The light transmitting region as described above is, for example, when a semiconductor light emitting element is grown on a sapphire substrate, transferred to a light transmitting substrate such as a glass substrate or a transparent plastic substrate, or a sapphire substrate or other growth substrate, Alternatively, a silicon substrate or the like may be thinly polished or ground to improve the light transmittance of the substrate itself, or an opening for light transmission or a thin portion may be formed by etching or the like. Further, a lens and other optical members may be interposed between the substrates. The lens and other optical members may also serve as spacers between the substrates.

  When transferring onto a substrate such as a glass substrate or a transparent plastic substrate, or when thinly polishing or grinding a sapphire substrate or other substrates, the rigidity of the substrate itself tends to be lost, but the flexibility of the substrate itself is reversed. Thus, problems such as cracks and warpage that may occur during heat treatment can be easily solved.

  In addition, the display device of the present invention can be used as a white or mixed-color lighting device by arranging a plurality of semiconductor light-emitting elements having three primary colors or two or more colors and injecting the same current into each light-emitting region. Also available. In addition, the display device is not limited to one having each color of red, blue, and green, and may be a display device having light-emitting elements of two or more colors.

  As a method for driving the display device according to the present invention, the same dot-sequential or line-sequential method as that of the active matrix liquid crystal display device can be used. The semiconductor light emitting device may have a different device structure when the emission wavelength is different. For example, a gallium nitride-based double heterostructure multilayer crystal grown on a sapphire substrate for blue and green light emitting diodes can be used, and aluminum gallium arsenide grown on a gallium arsenide substrate for red light emitting diodes or An indium aluminum gallium phosphide-based double heterostructure multilayer crystal can be used. The light-emitting diode constitutes a pixel composed of a set of three light-emitting elements having different wavelengths, but the set of different wavelengths is not limited to red, green, and blue, and may be a set of other colors. The semiconductor light emitting device is not limited to a light emitting diode, but may be a semiconductor laser having a required resonator.

  Hereinafter, the present invention will be described in more detail with reference to each embodiment. The semiconductor light emitting device of the present invention can be modified and changed without departing from the gist thereof, and the present invention is not limited to the following embodiments.

[First Embodiment]
The display device according to the present embodiment will be described with reference to FIGS. The display device according to the present embodiment is a display device having a structure in which one pixel structure including three semiconductor light emitting elements emitting red, blue, and green light is arranged in a matrix. Each pixel is arranged side by side.

  FIG. 1 is a plan view showing the structure of one pixel portion of the display device. As shown in FIG. 1, a red light emitting diode 11R, a blue light emitting diode 11B, and a green light emitting diode 11G are provided on a sapphire substrate 10 in both a vertical direction (V direction in the drawing) and a horizontal direction (H direction in the drawing). They are arranged diagonally out of alignment. Each of these light emitting diodes 11R, 11B, and 11G is configured by forming a first conductivity type clad layer, an active layer, and a second conductivity type clad layer on a GaN-based nitride semiconductor layer. Formed on the sapphire substrate 10 in the same step. Each of the light emitting diodes 11R, 11B, and 11G is a pyramid having a substantially hexagonal pyramid shape, and the light irradiation direction is a direction from the front side to the back side in FIG.

  Dummy elements 12R are formed in the six directions around the red light emitting diode 11R and in the hexagonal corners, respectively, and the red light emitting diode 11R is located at the center of the six dummy elements 12R. The magnesium-doped GaN layer of the red light emitting diode 11R is connected to a substantially rectangular p-electrode 15, and the p-electrode 15 is integrally formed or connected to a thin strip-shaped wiring layer 18 extending in the horizontal direction. I have. Similarly, dummy elements 13B are respectively formed in regions around the blue light emitting diode 11B in the six directions around the corners of the flat hexagon in which one pair of opposing sides is formed longer than the other sides, The blue light emitting diode 11B is located at the center of the six dummy elements 13B. The blue light emitting diode 11B has a band-like element shape compared to the other red light emitting diodes 11R and green light emitting diodes 11G. The magnesium-doped GaN layer of the blue light emitting diode 11B is connected to a substantially rectangular p-electrode 16, and this p-electrode 16 is formed integrally with a thin strip-shaped wiring layer 19 extending in the horizontal direction or electrically connected to the p-electrode 16. It is connected. Similarly, dummy elements 14G are respectively formed in the six directions around the green light emitting diode 11G and at the corners of the hexagon, and the green light emitting diode 11G is located at the center of the six dummy elements 14G. . The magnesium-doped GaN layer of the green light emitting diode 11G is connected to a substantially rectangular p-electrode 17, and this p-electrode 17 is formed integrally with or electrically connected to a thin strip-shaped wiring layer 20 extending in the horizontal direction. It is connected.

  Here, the dummy elements 12R, 13B, and 14G will be described in detail. These dummy elements 12R, 13B, and 14G include the light emitting diodes 11R, 11B for setting the spatial factor of each of the light emitting diodes 11R, 11B, and 11G. , 11G. Since the emission wavelength is controlled according to the space factor, by arranging these dummy elements 12R, 13B, and 14G around each of the light emitting diodes 11R, 11B, and 11G, the emission wavelength is positively and reliably set. Can be controlled. FIG. 2 shows a mask for selective growth for each emission color, and a pattern of light emitting diodes and dummy elements formed by crystal growth. The upper side of FIG. 2 is a mask for selective growth, and the lower side is a growth mask. 3 shows a pattern of a light emitting diode and a dummy element.

  First, in the red mask shown in FIG. 2 (R), a selective growth mask opening 25R for a light emitting diode is formed at the center, and dummy elements are provided in regions surrounding the hexagonal corners in six directions. Opening 26R is formed. The diameter of the opening 26R and the opening 25R can be, for example, about 0.1 μm to 10 μm, and the shape may be a polygon such as a substantially hexagon, a circle, an ellipse, or the like. The distance between the opening 26R for forming the dummy element and the opening 25R of the red light emitting diode 11R can be, for example, about 20 μm. Therefore, the size of the hexagon formed by the six openings 26R is It can be about 40 μm. By selectively growing using the openings 25R and 26R of the mask for red light emission, hexagonal pyramid-shaped light emitting diodes 11R and dummy elements 12R are formed at the positions of these openings 25R and 26R by selective growth.

  In the blue mask shown in FIG. 2B, a selective growth mask opening 25B for the light emitting diode is formed in a substantially rectangular pattern at the center, and corresponds to a flat hexagonal corner in six directions around the mask. An opening 27B for a dummy element is formed in each region. The diameter of the opening 27B can be, for example, about 0.1 μm to 10 μm, like the diameter of the opening 26R and the opening 25R. The size of the substantially rectangular opening 25B can be, for example, about 2 to 10 times the diameter of the opening 25R. The distance between the opening 27B for forming the dummy element and the opening 25B of the blue light emitting diode 11B can be, for example, about 20 μm as the respective distance from the end of the rectangular opening 25B, Therefore, the size in the longitudinal direction of the flat hexagon formed by the six openings 27B can be set to a size obtained by adding the size in the longitudinal direction of the openings 25B to about 40 μm. By selectively growing using the openings 25B and 27B of the blue light emitting mask, the hexagonal pyramid light emitting diode 11B and the dummy element 13B are formed at the positions of these openings 25B and 27B by selective growth.

  In the green mask shown in FIG. 2 (G), a selective growth mask opening 25G for the light emitting diode is formed at the center, and the area surrounding the hexagonal corner in six directions around the mask is provided for each dummy element. An opening 28G is formed. The diameter of the opening 28G and the opening 25G can be, for example, about 0.1 μm to 10 μm, and the shape may be a polygon such as a substantially hexagon, a circle, an ellipse, or the like. The distance between the opening 28G for forming the dummy element and the opening 25G of the green light emitting diode 11G can be, for example, about 10 μm. Therefore, the size of the hexagon formed by the six openings 28G is It can be about 20 μm. By performing selective growth using the openings 25G and 28G of the mask for green light emission, hexagonal pyramid light emitting diodes 11G and dummy elements 14G are formed at the positions of the openings 25G and 28G by selective growth.

  The light emitting diodes 11R, 11B, and 11G have different emission wavelengths from the setting of the space factor by the dummy elements 12R, 13B, and 14G. The red light emitting diode 11R emits light having a wavelength of about 620 nm with an energy gap of about 2.2 eV, for example. The blue light emitting diode 11B emits light having a wavelength of about 470 nm, for example, having an energy gap of about 2.7 eV. The green light emitting diode 11G emits light having a wavelength of about 520 nm with an energy gap of about 2.5 eV, for example. In this embodiment, each light emitting diode controls elements having the same layer structure formed on the same sapphire substrate 10 so that the emission wavelengths are different depending on the dummy elements 12R, 13B, and 14G. For example, a configuration may be adopted in which one or two of the three wavelengths have a different layer structure, and only a part of the light emitting diodes is provided with the dummy element.

  Next, the structure of the light emitting diode and the structure of the wiring portion will be described with reference to FIGS. FIG. 3 is a cross-sectional view taken along the line III-III of FIG. The red light-emitting diode 11R has the same layer structure as the blue light-emitting diode 11B and the green light-emitting diode 11G, except for the part (for example, impurity concentration, crystal structure, and the like) whose wavelength is controlled by the dummy elements 12R, 13B, and 14G. . As shown in FIG. 3, the red light-emitting diode 11R is a GaN-based light-emitting diode, and its structure is such that an AlN buffer layer, a silicon-doped GaN-based semiconductor layer, etc. A base growth layer 32 is formed, and a hexagonal pyramid-shaped GaN layer 35 selectively grown thereon is formed thereon. The hexagonal pyramid-shaped GaN layer 35 is a layer selectively grown through an opening 34 formed in a selection mask 33 made of a silicon oxide film formed on the base growth layer 32. The opening 34 corresponds to the opening 25R of the mask in FIG. The hexagonal pyramid-shaped GaN layer 35 is formed inside the opening 34 opening the selection mask 33 by MOCVD or the like.

  This GaN layer 35 is a pyramid-shaped growth layer covered with an S plane (1-101 plane) when the main surface of the sapphire substrate used at the time of growth is a C plane, and is made of silicon to be n-type. Is a doped region. In the GaN layer 35, crystal growth occurs from the inside of the opening 34 by the selection mask 33, and one conductive layer is formed in a self-aligned manner on the surface on which the S-plane, which is the inclined surface, is grown. At this time, the GaN layer 35 grows in a self-aligned manner so as to terminate on the selection mask 33 made of the insulating film used for the selective growth.

  The S-plane portion, which is the inclined surface of the GaN layer 35, functions as a double heterostructure clad. An InGaN layer 36 as an active layer is formed so as to cover the GaN layer 35, and a magnesium-doped GaN layer 37 is formed outside the InGaN layer 36. This magnesium-doped GaN layer 37 also functions as a clad. The magnesium-doped GaN layer 37 is extended at an end around the element so as to terminate on a selection mask 33 made of an insulating film. The magnesium-doped GaN layer 37 is self-aligned on the selection mask 33. grow up. Therefore, in order to configure the display device, the GaN layer 35 serving as a cladding layer, the InGaN layer 36 serving as an active layer, and the magnesium-doped GaN layer 37 serving as a cladding layer need not be separated from each other. The light emitting element can be arranged in a self-aligned position at the position where the opening is formed. Here, the thickness of the InGaN layer 36 as an active layer is, for example, about 3 nm, and the thickness of the magnesium-doped GaN layer 37 can be, for example, about 20 nm.

  The p-electrode 15 is formed on such a light emitting diode. The p-electrode 15 is formed by depositing a metal material such as Ni / Pt / Au or Ni (Pd) / Pt / Au formed on the magnesium-doped GaN layer 37. As an example of the layer structure of the p-electrode 15, Ni is about 1 nm, Pt is about 10 nm, and Au is about 100 nm. This p-electrode 15 is connected to a wiring layer 18 extending in the horizontal direction.

  The n-electrode on the side facing the p-electrode 15 is a common electrode. As shown in FIG. 4, the n-electrode 23 is a metal such as Ti / Al / Pt / Au at the opening 22 where the selection mask 33 is opened. It is formed by evaporating a material. The n-electrode 23 is connected to the underlying growth layer 32 and is electrically connected to the first conductivity type cladding layer of the hexagonal pyramid-shaped GaN layer 35 selectively grown on the underlying growth layer 32. Further, the n-electrode 23 is connected to the wiring layer 21 extending in the vertical direction on the surface side, and receives supply of a current to be supplied to the light-emitting diode.

  The display device of the present embodiment having the above-described structure has a structure in which at least the periphery of the element is surrounded by the surface on which the inclined surface is grown, and the display device is formed on the selection mask 33 such as an insulating film used for the selective growth. A GaN layer 35 serving as a cladding layer, an InGaN layer 36 serving as an active layer, a magnesium-doped GaN layer 37 serving as a cladding layer, and the like are formed in a self-aligned manner as a conductive layer having a structure terminated by the above. For this reason, element separation is not required or easy at the time of electrode formation, and an increase in the number of steps for manufacturing a display device can be suppressed. Further, in the display device of the present embodiment, a display device of multicolor emission can be manufactured from the function of controlling the emission wavelength of the dummy elements 12R, 13B, and 14G. Multicolor light emission can be achieved simply by changing the arrangement pattern of the dummy elements of the selection mask. Therefore, the manufacturing process can be greatly simplified as compared with the case where the light emitting elements formed by different manufacturing methods are combined, and a display device excellent in positional accuracy can be manufactured.

[Second embodiment]
The display device of the present embodiment will be described with reference to FIG. The display device of the present embodiment is a device having a structure in which three semiconductor light-emitting elements that emit red, blue, and green light are formed on three sapphire substrates 41, 42, and 43 for each light-emitting color, and are bonded together. is there. In FIG. 5, a sapphire substrate 41 is a substrate for green color formation on which a green light emitting diode 51G is formed, a sapphire substrate 42 is a substrate for blue color formation on which a blue light emitting diode 51B is formed, and a sapphire substrate 43 is This is a red-colored substrate on which red light-emitting diodes 51R are formed.

  Although only one element is shown on each of the sapphire substrates 41, 42, and 43 in FIG. 5, a plurality of light-emitting diodes are arranged in a matrix, respectively. It has a structure in which one pixel structure composed of three semiconductor light emitting elements emitting red, blue, and green light is arranged in a matrix in which horizontal and vertical directions are arranged. Each of the light emitting diodes 51R, 51B, and 51G is configured by forming a first conductivity type cladding layer, an active layer, and a second conductivity type cladding layer on a GaN-based nitride semiconductor layer. , 51B, and 51G are pyramid-shaped with a substantially hexagonal pyramid shape, and the light irradiation direction is the direction of the arrow h in FIG.

  On the sapphire substrate 43, dummy elements 63 are formed in regions around the red light emitting diodes 51R in the six directions and at the corners of the hexagon, and the red light emitting diodes 51R are located at the centers of the six dummy elements 63. are doing. The GaN layer on the surface side of the red light-emitting diode 51R is connected to a substantially rectangular p-electrode 66, and the p-electrode 66 is integrally formed or connected to a thin strip-shaped wiring layer 57 extending in the horizontal direction. I have. Similarly, dummy regions are provided on the sapphire substrate 42 in the six directions around the blue light-emitting diode 51B, where the pair of opposing sides is a flat hexagonal corner formed longer than the other sides. An element 62 is formed, and the blue light emitting diode 51B is located at the center of the six dummy elements 62. The blue light emitting diode 51B has a band-like element shape compared to the other red light emitting diodes 51R and green light emitting diodes 51G. The GaN layer on the surface side of the blue light emitting diode 51B is connected to a substantially rectangular p-electrode 65, and the p-electrode 65 is formed integrally with a thin strip-shaped wiring layer 56 extending in the horizontal direction or electrically connected thereto. It is connected. Similarly, on the sapphire substrate 41, dummy elements 61 are formed in regions around the green light emitting diode 11G in six directions and at the corners of the hexagon, and the green light emitting diode 51G is formed of six dummy elements 61. Centrally located. The front surface of the green light emitting diode 51G is connected to a substantially rectangular p-electrode 64, and the p-electrode 64 is formed integrally with or electrically connected to a thin strip-shaped wiring layer 55 extending in the horizontal direction. I have. Here, the structure and function of the dummy elements 63, 62 and 61 are substantially the same as the structure and function of the dummy elements 12R, 13B and 14G used in the display device of the first embodiment. Here, the description is omitted for simplicity.

  In the display device of the present embodiment, three sapphire substrates 41, 42, and 43 for monochromatic light emission are stacked in order to achieve multicolor. Therefore, the sapphire substrates 41, 42, and 43 themselves need to transmit light. For example, at least two substrates 42, 43 on the emission side in the light irradiation direction of the laminated substrates are light emitting elements on another substrate. Transmits the light emitted by. The sapphire substrates 41, 42, and 43 generally have good light transmittance and can transmit light from the light emitting diodes. In order to improve the light transmittance of the sapphire substrates 41, 42, and 43, the back surface of the sapphire substrate may be thinned by grinding or polishing, or an opening for light transmission may be formed by etching or the like. . Further, the substrate is not limited to a sapphire substrate, and other substrates can be used. For example, a GaAs substrate is used to form a red light-emitting diode, and blue and green light-emitting diodes are formed on a sapphire substrate. Alternatively, the three substrates or the two substrates requiring light transmission may be plastic substrates or glass substrates, and light-emitting diodes may be transferred onto these plastic substrates or glass substrates. .

  In a case where the substrates are overlapped with each other, light is extracted from the element so as to pass through the substrates. Therefore, when the substrates are overlapped with each other, the light emitting elements are prevented from overlapping in the light irradiation direction, and the size of at least 1 μm or more is set in the inter-element region between the plurality of semiconductor light emitting elements arranged on the base. Is formed so that light from the light emitting element of the substrate on the back side is transmitted. As described above, the sapphire substrates 41, 42, and 43 have a function of transmitting light, and can easily emit light from the diode on the back side by increasing the distance between the elements of the diode.

  The wiring layers 52, 53, and 54 for supplying current are formed so as not to overlap with the light emitting diodes, respectively, and in particular, the wiring layers 52, 53, and 54 of the three sapphire substrates 41, 42, and 43, respectively. Are located at the same position, wiring becomes easy when a common potential is applied. Further, since the wiring layers 52, 53, and 54 are metal thin films and have a light-shielding property, if the combined occupation area of the wiring layers 52, 53, and 54 is widened, the degree of freedom in the layout of the light emitting diodes is reduced. However, by setting the wiring layers 52, 53, and 54 of the sapphire substrates 41, 42, and 43 at the same position, the degree of freedom in designing the layout of the light emitting diodes can be increased.

[Third Embodiment]
The display device according to the present embodiment will be described with reference to FIGS. As in the first embodiment, the display device of the present embodiment is a display device having a structure in which one pixel structure including three semiconductor light emitting elements that emit red, blue, and green light is arranged in a matrix. Each pixel is arranged in a vertical direction and a horizontal direction of the display unit.

  FIG. 6 is a plan view showing the structure of one pixel portion of the display device. As shown in FIG. 6, a red light emitting diode 71R, a blue light emitting diode 71B, and a green light emitting diode 71G are provided on a sapphire substrate 70 in both a vertical direction (V direction in the figure) and a horizontal direction (H direction in the figure). It is arranged diagonally shifted. Each of these light emitting diodes 71R, 71B, and 71G is configured by forming a first conductivity type cladding layer, an active layer, and a second conductivity type cladding layer on a GaN-based nitride semiconductor layer. Of the sapphire substrate 70 in the same process. Each of the light emitting diodes 71R, 71B, and 71G has a substantially hexagonal pyramid pyramid shape, and the light irradiation direction is from the front side to the back side in FIG.

  A dummy element 72R extending in the shape of a hexagonal side is formed around the red light emitting diode 71R, and the red light emitting diode 71R is located at the center of the dummy element 72R extending in the form of a hexagonal side. ing. The magnesium-doped GaN layer of the red light emitting diode 71R is connected to a substantially rectangular p-electrode 75, and the p-electrode 75 is integrally formed or connected to a thin strip-shaped wiring layer 78 extending in the horizontal direction. I have. Similarly, around the blue light emitting diode 71B, dummy elements 73B are formed, each of which extends in the shape of a flat hexagonal side in which a pair of opposing sides is formed longer than the other sides, and emits blue light. The diode 71B is located at the center of the dummy element 73B extending in the shape of a flat hexagonal side. The blue light emitting diode 71B has a band-like element shape compared to the other red light emitting diodes 71R and green light emitting diodes 71G. The magnesium-doped GaN layer of the blue light-emitting diode 71B is connected to a substantially rectangular p-electrode 76, and the p-electrode 76 is formed integrally with or electrically connected to a thin strip-shaped wiring layer 79 extending in the horizontal direction. It is connected. Similarly, a dummy element 74G extending in the shape of a hexagonal side is formed around the green light emitting diode 71G, and the green light emitting diode 71G is located at the center of the dummy element 74G extending in the form of the hexagonal side. It is located in. The magnesium-doped GaN layer of the green light-emitting diode 71G is connected to a substantially rectangular p-electrode 77, and the p-electrode 77 is formed integrally with or electrically connected to a thin strip-shaped wiring layer 80 extending in the horizontal direction. It is connected.

  Here, the dummy elements 72R, 73B, and 74G will be described in detail. These dummy elements 72R, 73B, and 74G are arranged around the light emitting diodes 71R, 71B, and 71G to set the space factor of the light emitting diodes 71R, 71B, and 71G. It is arranged in. Since the emission wavelength is controlled in accordance with the space factor, by arranging these dummy elements 72R, 73B, 74G around the respective light emitting diodes 71R, 71B, 71G, the emission wavelength is positively and reliably set. Can be controlled. FIG. 7 shows a mask for selective growth for each emission color, and a pattern of light emitting diodes and dummy elements formed by crystal growth. The upper side of FIG. 7 is a mask for selective growth, and the lower side is a growth mask. 3 shows a pattern of a light emitting diode and a dummy element.

  First, in the red mask shown by (R) in FIG. 7, a selective growth mask opening 85R for a light emitting diode is formed at the center, and a dummy element opening extending in the shape of a hexagonal side is formed around the opening 85R. A portion 86R is formed. The diameter of the opening 85R can be, for example, about 0.1 μm to 10 μm, and the shape may be a polygon such as a substantially hexagon, a circle, an ellipse, or the like. The distance between the opening 86R for forming the dummy element and the opening 85R of the red light emitting diode 11R can be, for example, about 20 μm. Therefore, the size of the hexagon formed by the opening 86R is about 40 μm. It can be. By selectively growing using the openings 85R and 86R of the red light emitting mask, the selective growth is performed at the positions of these openings 85R and 86R, and the hexagonal pyramid-shaped light emitting diode 71R and the hexagonal sides are formed. The dummy element 72R thus formed is formed. The light emitting diode 71R located at the center is protected by the dummy element 72R.

  In the blue mask shown in FIG. 7 (B), a selective growth mask opening 85B for the light emitting diode is formed in a substantially rectangular pattern at the center, and extends in the shape of a flat hexagonal side around the opening. An opening 87B for a dummy element is formed. The size of the substantially rectangular opening 85B can be, for example, about 2 to 10 times the diameter of the opening 85R. The distance between the opening 87B for forming the dummy element and the opening 85B of the blue light emitting diode 11B can be, for example, about 20 μm as the distance from the end of the rectangular opening 85B, For this reason, the longitudinal size of the flat hexagon formed by the openings 87B extending in the shape of the flat hexagonal sides may be approximately 40 μm plus the longitudinal size of the openings 85B. it can. By performing selective growth using the openings 85B and 87B of the mask for blue light emission, hexagonal pyramid-shaped light emitting diodes 71B and dummy elements 73B are formed at the positions of these openings 85B and 87B by selective growth.

  In the green mask shown in FIG. 7G, a selective growth mask opening 85G for a light emitting diode is formed at the center, and a dummy element opening 88G extending in the shape of a hexagonal side is formed around the mask 85G. Is formed. The diameter of the opening 85G can be, for example, about 0.1 μm to 10 μm, and the shape thereof can be a polygon such as a substantially hexagon, a circle, an ellipse, or the like. The distance between the opening 88G for forming the dummy element and the opening 85G of the green light emitting diode 11G can be, for example, about 10 μm, and therefore, the opening 88G extending in the shape of a hexagonal side. The size of the hexagon formed by is about 20 μm. By performing selective growth using the openings 85G and 88G of the mask for green light emission, hexagonal pyramid-shaped light emitting diodes 71G and dummy elements 74G are formed at the positions of the openings 85G and 88G by selective growth.

  The light emitting diodes 71R, 71B, and 71G also have different emission wavelengths by the dummy elements 72R, 73B, and 74G, similarly to the setting of the space factor by the dummy elements 12R, 13B, and 14G. In this embodiment, each light emitting diode controls elements having the same layer structure formed on the same sapphire substrate 70 so that the light emitting wavelengths are different depending on the dummy elements 72R, 73B, and 74G. For example, a configuration may be adopted in which one or two of the three wavelengths have a different layer structure, and only a part of the light emitting diodes is provided with the dummy element.

  Next, the structure of the light emitting diode and the structure of the wiring portion will be described with reference to FIGS. FIG. 8 is a sectional view taken along the line VIII-VIII in FIG. 6, and shows a structural section of the red light emitting diode 71R. The red light-emitting diode 71R has the same layer structure as the blue light-emitting diode 71B and the green light-emitting diode 71G, except for a portion (for example, impurity concentration, crystal structure, and the like) whose wavelength is controlled by the dummy elements 72R, 73B, and 74G. . As shown in FIG. 8, the red light-emitting diode 71R is a GaN-based light-emitting diode, and its structure is such that an AlN buffer layer, a silicon-doped GaN-based semiconductor layer, etc. An underlying growth layer 92 is formed, and a hexagonal pyramid-shaped GaN layer 95 selectively grown thereon is formed thereon. The hexagonal pyramid-shaped GaN layer 95 is a layer selectively grown through an opening 94 formed in a selection mask 93 made of a silicon oxide film formed on a base growth layer 92. The opening 94 corresponds to the opening 25R of the mask in FIG. The hexagonal pyramid-shaped GaN layer 95 is formed by an MOCVD method or the like inside the opening 94 that opens the selection mask 93.

  This GaN layer 95 is a pyramid-shaped growth layer covered with an S-plane (1-101 plane) when the main surface of the sapphire substrate used at the time of growth is a C-plane. Is a doped region. In the GaN layer 95, crystal growth occurs from the inside of the opening 94 by the selection mask 93, and one conductive layer is formed in a self-aligned manner on the plane on which the S plane, which is the inclined plane, is grown. At this time, the GaN layer 95 grows in a self-aligned manner so as to terminate on the selection mask 93 made of the insulating film used for the selective growth. The S-plane portion, which is the inclined surface of the GaN layer 95, functions as a double heterostructure cladding. An InGaN layer 96 serving as an active layer is formed so as to cover the GaN layer 95, and a magnesium-doped GaN layer 97 is formed outside the InGaN layer 96. This magnesium-doped GaN layer 97 also functions as a clad. The magnesium-doped GaN layer 97 is extended at an end around the element so as to terminate on a selection mask 93 made of an insulating film. The magnesium-doped GaN layer 97 is self-aligned on the selection mask 93. grow up. Therefore, in order to configure the display device, the GaN layer 95 serving as the cladding layer, the InGaN layer 96 serving as the active layer, and the magnesium-doped GaN layer 97 serving as the cladding layer do not need to be separated from each other. The light emitting element can be arranged in a self-aligned position at the position where the opening is formed. Here, the thickness of the InGaN layer 96 serving as the active layer is, for example, about 3 nm, and the thickness of the GaN layer 97 doped with magnesium can be, for example, about 20 nm.

  A p-electrode 75 is formed in such a light emitting diode. The p-electrode 75 is formed by depositing a metal material such as Ni / Pt / Au or Ni (Pd) / Pt / Au formed on the magnesium-doped GaN layer 97. As an example of the layer structure of the p-electrode 75, Ni is about 1 nm, Pt is about 10 nm, and Au is about 100 nm. This p-electrode 75 is connected to a wiring layer 78 extending in the horizontal direction.

  The n-electrode on the side facing the p-electrode 15 is a common electrode. As shown in FIG. 9, the n-electrode 83 is a metal such as Ti / Al / Pt / Au at the opening 82 where the selection mask 93 is opened. It is formed by evaporating a material. The n-electrode 83 is connected to the underlying growth layer 92 and is electrically connected to the first conductivity type cladding layer of the hexagonal pyramid-shaped GaN layer 95 selectively grown on the underlying growth layer 92. Further, the n-electrode 83 is connected to a wiring layer 81 extending in the vertical direction on the surface side, and receives supply of a current to be supplied to the light-emitting diode.

  The display device according to the present embodiment having the above-described structure has a structure in which at least the periphery of the element is surrounded by the surface on which the inclined surface is grown, and is formed on the selection mask 93 such as an insulating film used for the selective growth. A GaN layer 95 serving as a cladding layer, an InGaN layer 96 serving as an active layer, a magnesium-doped GaN layer 97 serving as a cladding layer, and the like are formed in a self-aligned manner as a conductive layer having a structure ending in. For this reason, element separation is not required or easy at the time of electrode formation, and an increase in the number of steps for manufacturing a display device can be suppressed. Further, in the display device of the present embodiment, a display device of multicolor light emission can be manufactured from the function of controlling the emission wavelength of the dummy elements 72R, 73B, 74G extended linearly, and the same sapphire substrate 70 In the same manufacturing process, multicolor light emission can be achieved by simply changing the arrangement pattern of the dummy elements of the selection mask. Therefore, the manufacturing process can be greatly simplified as compared with the case where the light emitting elements formed by different manufacturing methods are combined, and a display device excellent in positional accuracy can be manufactured.

[Fourth embodiment]
The display device according to the present embodiment will be described with reference to FIGS. The display device according to the present embodiment is a device having a structure in which three semiconductor light-emitting elements for emitting red, blue, and green light are formed on three sapphire substrates 100R, 100B, and 100G for each of the light-emitting colors and bonded together. It is.

  FIG. 10 is a plan view showing a state in which three sapphire substrates 100R, 100B, and 100G are stacked and viewed from above. The blue light emitting diode 101, the green light emitting diode 111, and the red light emitting diode 121 are each formed by forming a first conductivity type clad layer, an active layer, and a second conductivity type clad layer on a GaN-based nitride semiconductor layer. It has a substantially pyramid-like pyramid shape by selective growth. The structure of these light emitting diodes 101, 111, and 121 is substantially the same as the structure of the light emitting diode 11R of the above-described first embodiment. In order to make the emission wavelengths blue, green, and red, indium in the active layer is used. The doping amount and the like are controlled.

  11 to 13 are plan views of the respective sapphire substrates 100B, 100G, and 100R. FIG. 11 is a plan view of the sapphire substrate 100B on which the blue light emitting diode 101 is formed, and FIG. FIG. 13 is a plan view of the sapphire substrate 100R on which the red light emitting diode 121 is formed. As shown in FIG. 11, the blue light emitting diodes 101 are arranged in a matrix on a sapphire substrate 100B, and a plurality of horizontal wirings 102 are formed as wiring layers extending in the horizontal direction. The vertical wiring 103 is formed to extend. The horizontal wiring 102 is connected to the p electrode of each blue light emitting diode 101. The n-electrode 114 of each blue light emitting diode 101 is formed in the opening of the selection mask and is connected to the vertical wiring 103. Although one n-electrode 114 is provided for one blue light-emitting diode 101, it can be shared as in the above-described embodiment.

  Next, the green light emitting diodes 111 are arranged in a matrix as shown in FIG. 12, and a plurality of horizontal wirings 112 are formed as wiring layers extending in the horizontal direction, and the green light emitting diodes 111 extend in a direction perpendicular to these. Thus, the vertical wiring 113 is formed. Here, the arrangement pitch of the green light emitting diodes 111 is the same as the arrangement pitch of the blue light emitting diodes 101 described above, but has a structure shifted by one element in the vertical direction in the figure. The horizontal wiring 112 is connected to the p electrode of each green light emitting diode 111. Further, the n-electrode 114 of each green light emitting diode 111 is formed in the opening of the selection mask and is connected to the vertical wiring 113. Although one n-electrode 114 is provided for one green light-emitting diode 111, it can be shared as in the above-described embodiment.

  Similarly, the red light emitting diodes 121 are arranged in a matrix as shown in FIG. 13, and a plurality of horizontal wirings 112 are formed as wiring layers extending in the horizontal direction, and the red light emitting diodes 121 extend in a direction perpendicular to these. Thus, a vertical wiring 113 is formed. Here, the arrangement pitch of the red light-emitting diodes 121 is the same as the arrangement pitch of the blue light-emitting diodes 101 described above, but has a structure shifted from the green light-emitting diode 111 by one element in the vertical direction in the figure. The horizontal wiring 122 is connected to the p electrode of each red light emitting diode 121. Further, the n-electrode 124 of each red light-emitting diode 121 is formed in the opening of the selection mask and is connected to the vertical wiring 123. Although one n-electrode 124 is provided for one red light-emitting diode 121, it can be shared similarly to the above-described embodiment.

  Here, the vertical wiring 103 of the sapphire substrate 100B on which the blue light emitting diode 101 is formed, the vertical wiring 113 of the sapphire substrate 100G on which the green light emitting diode 111 is formed, and the vertical wiring 123 of the sapphire substrate 100R on which the red light emitting diode 121 is formed. Are formed so as to occupy the same horizontal position. Similarly, the n-electrode 104 on the sapphire substrate 100B, the n-electrode 114 on the sapphire substrate 100G, and the n-electrode 124 on the sapphire substrate 100R are formed so as to occupy the same horizontal and vertical positions. . Since the vertical wirings 103, 113 and 123 and the n-electrode are formed so as to overlap with each other, the wiring becomes easy when a common potential is applied. By setting each wiring layer at the same position, the degree of freedom in designing the layout of the light emitting diode can be increased.

  Next, the structure of the light emitting diode and the structure of the wiring portion will be described with reference to FIGS. FIG. 14 is a cross-sectional view taken along the line XIV-XIV of FIG. The blue light-emitting diode 101 is a GaN-based light-emitting diode, and its structure is such that a base growth layer 132 having an AlN buffer layer, a silicon-doped GaN-based semiconductor layer, and the like on a sapphire substrate 100B having a C + plane as a main surface. A GaN layer 135 having a hexagonal pyramid shape formed and selectively grown thereon is formed thereon. The hexagonal pyramid-shaped GaN layer 135 is a layer selectively grown through an opening 134 formed in a selection mask 133 made of a silicon oxide film formed on a base growth layer 132. The opening 134 corresponds to the opening 25R of the mask in FIG. The hexagonal pyramid-shaped GaN layer 135 is formed by an MOCVD method or the like inside the opening 134 that opens the selection mask 133.

  This GaN layer 135 is a pyramid-shaped growth layer covered with an S-plane (1-101 plane) when the main surface of the sapphire substrate used at the time of growth is a C-plane. Is a doped region. In the GaN layer 135, crystal growth occurs from the inside of the opening 134 by the selection mask 133, and one conductive layer is formed in a self-aligned manner on the surface on which the S-plane, which is the inclined surface, is grown. At this time, the GaN layer 135 grows in a self-aligned manner so as to terminate on the selection mask 133 made of the insulating film used for the selective growth. The S-plane portion, which is the inclined surface of the GaN layer 135, functions as a double heterostructure clad. An InGaN layer 136 as an active layer is formed so as to cover the GaN layer 135, and a magnesium-doped GaN layer 137 is formed outside the InGaN layer 136. This magnesium-doped GaN layer 137 also functions as a clad. The magnesium-doped GaN layer 137 extends so as to terminate on the selection mask 133 made of an insulating film at an edge around the element, and the magnesium-doped GaN layer 137 is self-aligned on the selection mask 133. grow up. Therefore, in order to configure the display device, the GaN layer 135 serving as a cladding layer, the InGaN layer 136 serving as an active layer, and the magnesium-doped GaN layer 137 serving as a cladding layer do not need to be separated from each other. The light emitting element can be arranged in a self-aligned position at the position where the opening is formed. Here, the thickness of the InGaN layer 136 as the active layer is, for example, about 3 nm, and the thickness of the magnesium-doped GaN layer 137 can be, for example, about 20 nm.

  A p-electrode 138 is formed in such a light emitting diode. The p-electrode 138 is formed by depositing a metal material such as Ni / Pt / Au or Ni (Pd) / Pt / Au formed on the magnesium-doped GaN layer 137. As an example of the layer structure of the p-electrode 138, Ni is about 1 nm, Pt is about 10 nm, and Au is about 100 nm. This p-electrode 138 is connected to the wiring layer 102 extending in the horizontal direction.

  The n-electrode on the side opposite to the p-electrode 138 is a common electrode. As shown in FIG. It is formed by evaporating a material. The n-electrode 104 is connected to the base growth layer 132 and is electrically connected to the first conductivity type cladding layer of the hexagonal pyramid-shaped GaN layer 135 selectively grown on the base growth layer 132. The n-electrode 104 is connected to the wiring layer 103 extending in the vertical direction on the surface side, and receives supply of a current to be supplied to the light-emitting diode.

  The display device according to the present embodiment having the above-described structure has a structure in which at least the periphery of the element is surrounded by the surface on which the inclined surface is grown, and is formed on the selection mask 133 such as an insulating film used for the selective growth. A GaN layer 135 serving as a cladding layer, an InGaN layer 136 serving as an active layer, a magnesium-doped GaN layer 137 serving as a cladding layer, and the like are formed in a self-aligned manner as a conductive layer having a structure terminated at the end. For this reason, element separation is not required or easy at the time of electrode formation, and an increase in the number of steps for manufacturing a display device can be suppressed. Furthermore, in the display device of the present embodiment, a display device having excellent positional accuracy is manufactured.

[Fifth Embodiment]
Hereinafter, the display device of the present embodiment will be described with reference to FIGS. The display device of this embodiment has a structure in which three light-emitting diodes emitting red, blue, and green light are arranged on three substrates for each light-emitting color, and the substrates are stacked. Note that the present embodiment focuses on the laminated structure of the substrates and the method of transferring elements (light emitting diodes) to each substrate.

  First, a method of arranging light emitting diodes in the display device of the present embodiment and a configuration of the display device will be described. FIG. 16 is an exploded perspective view schematically showing a pixel array of the display device of the present invention when the light-emitting diodes 211, 212, and 213 of three colors are transferred to different substrates and the respective substrates are superimposed. FIG. 17 is a cross-sectional view illustrating the configuration of the display device in that case. Red, green, and blue light-emitting diodes (resin-formed chips) 211, 212, and 213 are mounted on substrates 214, 215, and 216, respectively. The light emitting diodes on each substrate are not in the form of a simple matrix at equal intervals on the left and right, but are in the form of a plurality of rows, and each row is arranged in parallel with an interval of at least two rows. A light transmissive region is formed between each row, and the row of light emitting diodes on the substrate located in front is one row so that light from the light emitting diodes on the substrate arranged rearward (back side) in the light irradiation direction is transmitted. It is arranged by shifting. In the figure, the substrates are stacked in the order of a blue light emitting diode substrate 216, a green light emitting diode substrate 215, and a red light emitting diode substrate 214 from the back side of the display device, and a black filter and a full-surface protection substrate 217 are arranged on the front surface thereof. Since each of the pixel images 211A, 212A, and 213A is constituted by a light emitting diode of three colors as one unit (part A surrounded by a broken line in FIG. 16), a certain degree of positional relationship between the substrates is required. Therefore, an alignment mark 222 is provided on each of the substrates 214, 215, and 216, and a process such as a position adjustment is interposed in a manufacturing process, thereby preventing a displacement. The arrangement of the light-emitting diodes on each substrate is different from the arrangement in which the three colors of blue, green, and red are adjacently formed on the black filter to form light-emitting diodes of the color corresponding to the substrate. What is necessary is just to make it the structure which thinned out the light-emitting diode of two colors, and does not need to be the row shape as shown in figure.

  As shown in FIG. 17, a spacer 219 for maintaining a space between the substrates can be provided between the black filter 217 and the substrates 214, 215, and 216. The substrates 214, 215, and 216 are fixed to each other using, for example, an ultraviolet-curable (UV resin or the like) adhesive 221 or 223. In FIG. 17, for example, a space through which light does not pass, such as a back side of the light emitting elements 211 and 212 (a portion surrounded by a broken line B in FIG. 17), can be used as a space for disposing various members such as a driver (drive circuit).

  Further, a lens and other optical members may be interposed between the substrates. FIG. 18 illustrates an example in which a condenser lens is provided. Here, condensing lenses 220 are provided on the substrates 212 and 213 on which the green and blue light emitting diodes are mounted in order to prevent a decrease in transmittance (illuminance) due to reflection or divergence by the substrates 211 and 212 on the front surface. The lens and other optical members may also serve as spacers between the substrates. To reduce the transmittance due to the reflection or divergence of light transmitted through the front substrate due to the superposition, an optical component such as a diffraction grating may be arranged without using the condenser lens 220.

  From the front protective substrate 217 provided with the black filter, three-color pixels 211A to 213A corresponding to the three-color light-emitting diodes 211 to 213 are projected, and color display can be performed. The black filter may be provided on the substrate without being disposed on the front protective substrate.

  Generally, when manufacturing an image display device using light emitting diodes, it is necessary to arrange the light emitting diodes apart from each other. In this embodiment mode, the light emitting diodes on each substrate are not arranged in a simple matrix at equal intervals on the left and right, but in a plurality of rows, and each row is arranged in parallel with an interval of at least two rows. Although there are various methods for this arrangement, a two-step enlargement transfer method will be described here as an example. In the two-step enlargement transfer method, first, an element formed on the first substrate with a high degree of integration is transferred to a temporary holding member so as to be separated from a state where the elements are arranged on the first substrate. Then, a two-stage enlarged transfer is performed in which the element held by the temporary holding member is further separated and transferred onto the second substrate. In this embodiment, the transfer is performed in two stages, but the transfer may be performed in three stages or more stages depending on the degree of enlargement in which the elements are spaced apart.

  FIG. 19 is a diagram showing the basic steps of the two-step enlargement transfer method. First, an element 202 such as a light emitting element is densely formed on a first substrate 200 shown in FIG. By forming the elements densely, the number of elements generated per substrate can be increased, and the product cost can be reduced. The first substrate 200 is a substrate on which various elements can be formed, such as a semiconductor wafer, a glass substrate, a quartz glass substrate, a sapphire substrate, and a plastic substrate. Each element 202 is formed directly on the first substrate 200. Alternatively, an array of elements formed on another substrate may be used.

  Next, as shown in FIG. 19B, each element 202 is transferred from the first substrate 200 to a temporary holding member 201 indicated by a broken line in the figure, and each element 202 is held on this temporary holding member 201. Is done. Here, adjacent elements 202 are separated and arranged in a matrix as shown in the figure. That is, the elements 202 are transferred so as to extend the space between the elements in the x direction, but are also transferred so as to expand the space between the elements in the y direction perpendicular to the x direction. In general, the distance to be separated at this time is not particularly limited, and may be, for example, a distance in consideration of formation of a resin portion and formation of an electrode pad in a subsequent step. When the image is transferred from the first substrate 200 onto the temporary holding member 201, all the elements on the first substrate 200 can be separated and transferred. In this case, the size of the temporary holding member 201 only needs to be equal to or larger than the number obtained by multiplying the number of the elements 202 arranged in a matrix (in each of the x direction and the y direction) by the separated distance. In addition, it is also possible that some elements on the first substrate 200 are transferred onto the temporary holding member 201 while being separated from each other.

  After such a first transfer step, as shown in FIG. 19C, since the elements 202 existing on the temporary holding member 201 are separated from each other, resin The coating and the formation of the electrode pads are performed. The resin coating around the element is formed to facilitate the formation of the electrode pad and to facilitate the handling in the next second transfer step. Since the electrode pads are formed after the second transfer step following the final wiring, as described later, the electrode pads are formed to have a relatively large size so that a wiring failure does not occur. The electrode pads are not shown in FIG. The resin forming chip 204 is formed by covering the periphery of each element 202 with the resin 203. The element 202 is located substantially at the center of the resin-formed chip 204 on a plane, but may be located at a position deviated to one side or a corner.

  Next, as shown in FIG. 19D, a second transfer step is performed. In the second transfer step, the elements 202 arranged in a matrix on the temporary holding member 201 are transferred onto the second substrate 205 so as to be further apart from each other with the resin forming chip 204. Also in the second transfer step, the adjacent elements 202 are separated from each other with the resin forming chip 204, and are arranged in a matrix as shown in the drawing. That is, the elements 202 are transferred so as to extend the space between the elements in the x direction, but are also transferred so as to expand the space between the elements in the y direction perpendicular to the x direction. Assuming that the position of the element arranged in the second transfer step is a position corresponding to the pixel of the final product such as an image display device, approximately an integral multiple of the pitch between the original elements 202 is arranged in the second transfer step. This is the pitch of the element 202. Here, assuming that the enlargement ratio of the pitch separated from the first substrate 200 by the temporary holding member 201 is n, and the enlargement ratio of the pitch separated from the temporary holding member 201 by the second substrate 205 is m, approximately an integral multiple. Is represented by E = n × m.

  Wiring is applied to each element 202 separated from the second substrate 205 together with the resin forming chip 204. At this time, wiring is performed by using the previously formed electrode pads and the like while minimizing poor connection. For example, when the element 202 is a light-emitting element such as a light-emitting diode, the wiring includes wiring to a p-electrode and an n-electrode.

In the two-stage enlarged transfer method shown in FIG. 19, an electrode pad can be formed using the space separated after the first transfer, and wiring is provided after the second transfer. Wiring is performed by using the formed electrode pads and the like while minimizing poor connection. Therefore, the yield of the image display device can be improved. Further, in the two-stage enlargement transfer method of the present example, the steps for separating the distance between the elements are two steps, and by performing such a plurality of steps of enlargement transfer for separating the distance between the elements, the transfer count is actually increased. Will be reduced. That is, for example, here, the enlargement rate of the pitch separated from the first substrate 200 on the temporary holding member 201 is set to 2 (n = 2), and the expansion of the separated pitch on the second substrate 205 from the temporary holding member 201 is set. Assuming that the magnification is 2 (m = 2), if it is attempted to transfer to the area enlarged by one transfer, the final enlargement ratio is 4 × 2 × 2, and the transfer of the square 16 times, that is, the first substrate Is required to be performed 16 times, but in the two-step enlargement transfer method of this example, the number of alignments is four times the square of the enlargement rate 2 in the first transfer step and the enlargement rate 2 in the second transfer step. That is, a total of eight times, which is simply a sum of four squares, is sufficient. That is, when the same transfer magnification is intended, since (n + m) ² = n ² +2 nm + m ² , the number of transfers can be reduced by 2 nm without fail. Accordingly, the number of times of the manufacturing process can be reduced by the number of times and costs, which is advantageous particularly when the enlargement ratio is large.

  In the second transfer step, the element (light emitting diode) 202 is handled as a resin-formed chip 204 and is transferred from the temporary holding member 201 to the second substrate 205, respectively. This will be described with reference to FIG. The resin-formed chip 230 has a structure in which the periphery of the light-emitting element 231 that is spaced apart is fixed with a resin 232, and such a resin-formed chip 230 transfers the light-emitting element 231 from the temporary holding member to the second substrate. It can be used when transferring. The main surface of the resin-formed chip 230 has a substantially square shape on a substantially flat plate. The shape of the resin-formed chip 230 is a shape formed by solidifying the resin 232. Specifically, an uncured resin is applied to the entire surface so as to include each light emitting element 231, and after curing, the edge of the edge is hardened. This is a shape obtained by cutting a portion by dicing or the like.

  Electrode pads 233 and 234 are formed on the front side and the back side of the substantially flat resin 232, respectively. The electrode pads 233 and 234 are formed by forming a conductive layer such as a metal layer or a polycrystalline silicon layer which is a material of the electrode pads 233 and 234 on the entire surface, and patterning into a required electrode shape by a photolithography technique. Is done. These electrode pads 233 and 234 are formed so as to be connected to the p-electrode and the n-electrode of the light emitting element 231 respectively. If necessary, via holes are formed in the resin 232. The reason why the positions of the electrode pads 233 and 234 are shifted on the flat plate is to prevent the contacts from being overlapped even when a contact is taken from the upper side at the time of final wiring formation. The shape of the electrode pads 233 and 234 is not limited to a square, but may be another shape.

  By configuring such a resin forming chip 230, the periphery of the light emitting element 231 is covered with the resin 232 and the electrode pads 233 and 234 can be formed with high accuracy by flattening, and the electrode pad 233 is formed in a wider area than the light emitting element 231. , 234 can be extended, and when the transfer in the next second transfer step is advanced by the suction jig, the handling becomes easy. As will be described later, since the wiring is performed after the second transfer step in which the final wiring is performed, wiring using the relatively large-sized electrode pads 233 and 234 prevents wiring failures.

  Next, a specific method of manufacturing an image display device to which a method of arranging light emitting elements by a two-stage enlargement transfer method is applied will be described. As the light emitting element, for example, a GaN-based light emitting diode is used. First, as shown in FIG. 22, a plurality of light emitting diodes 252 are formed on the main surface of the first substrate 251 in a dense state. The size of the light emitting diode 252 can be minute, for example, about 20 μm on each side. As a constituent material of the first substrate 251, a material having a high transmittance with respect to the wavelength of the laser irradiated to the light emitting diode 252, such as a sapphire substrate, is used. Although the light emitting diode 252 is formed up to the p-electrode and the like, the final wiring is not yet formed, and a groove 252g for element isolation is formed, and the individual light emitting diodes 252 can be separated. The formation of the groove 252g is performed by, for example, reactive ion etching.

  Next, the light emitting diodes 252 on the first substrate 251 are transferred onto the first temporary holding member 253. Here, as an example of the first temporary holding member 253, a glass substrate, a quartz glass substrate, a plastic substrate, or the like can be used. In this example, a quartz glass substrate was used. Further, on the surface of the first temporary holding member 253, a release layer 254 functioning as a release layer is formed. For the release layer 254, a fluorine coat, a silicon resin, a water-soluble adhesive (for example, polyvinyl alcohol: PVA), polyimide, or the like can be used. Here, polyimide is used.

  At the time of the transfer, as shown in FIG. One temporary holding member 253 is overlaid. In this state, as shown in FIG. 23, the adhesive 255 is irradiated with ultraviolet light (UV) from the back surface side of the first temporary holding member 253, and is cured. The first temporary holding member 253 is a quartz glass substrate, and the ultraviolet light passes through the first temporary holding member 253 to quickly cure the adhesive 255.

  At this time, since the first temporary holding member 253 is supported by the light emitting diode 252, the distance between the first substrate 251 and the first temporary holding member 253 is determined by the height of the light emitting diode 252. Will be. As shown in FIG. 23, if the adhesive 255 is cured in a state where the first temporary holding member 253 is overlapped so as to be supported by the light emitting diode 252, the thickness t of the adhesive 255 becomes equal to the first substrate. This is regulated by the distance between the first temporary holding member 253 and the height of the light emitting diode 252. That is, the light emitting diode 252 on the first substrate 251 serves as a spacer, and an adhesive layer having a constant thickness is formed between the first substrate 251 and the first temporary holding member 253. . As described above, in the above-described method, the thickness of the adhesive layer is determined by the height of the light emitting diode 252, so that it is possible to form an adhesive layer having a constant thickness without strictly controlling the pressure.

  After the adhesive 255 is cured, as shown in FIG. 24, a laser is irradiated to the light emitting diode 252 from the back surface of the first substrate 251 and the light emitting diode 252 is separated from the first substrate 251 using laser ablation. . Since the GaN-based light emitting diode 252 is decomposed into metallic Ga and nitrogen at the interface with sapphire, it can be relatively easily separated. An excimer laser, a harmonic YAG laser, or the like is used as a laser for irradiation. By the separation using the laser ablation, the light emitting diode 252 is separated at the interface of the first substrate 251 and is transferred onto the temporary holding member 253 in a state embedded in the adhesive 255.

FIG. 25 shows a state where the first substrate 251 has been removed by the peeling. At this time, the GaN-based light-emitting diode has been separated from the first substrate 251 made of a sapphire substrate by a laser, and Ga256 has been deposited on the separated surface. Therefore, wet etching is performed with an aqueous NaOH solution or diluted nitric acid to remove Ga256 as shown in FIG. Further, as shown in FIG. 27, the surface is cleaned by oxygen plasma (O ₂ plasma), the adhesive 255 is cut by dicing grooves 257 by dicing, and the light emitting diodes 252 are diced. Perform In the dicing process, dicing using a normal blade is performed, and when a narrow notch of 20 μm or less is required, processing using a laser using the above laser is performed. Although the cut width depends on the size of the light emitting diode 252 covered with the adhesive 255 in the pixel of the image display device, as an example, a groove is formed by an excimer laser to form a chip shape.

  In order to selectively separate the light emitting diodes 252, first, as shown in FIG. 28, a thermoplastic adhesive 258 is applied on the cleaned light emitting diodes 252, and a second temporary holding member 259 is stacked thereon. Like the first temporary holding member 253, a glass substrate, a quartz glass substrate, a plastic substrate, or the like can be used for the second temporary holding member 259. In this example, a quartz glass substrate was used. Also, a release layer 260 made of polyimide or the like is formed on the surface of the second temporary holding member 259.

  Next, as shown in FIG. 29, a laser is irradiated from the back side of the first temporary holding member 253 only to a position corresponding to the light emitting diode 252a to be transferred, and the light emitting diode 252a is first irradiated by laser ablation. From the temporary holding member 253. At the same time, a visible or infrared laser beam is applied to the position corresponding to the light-emitting diode 252a to be transferred from the back side of the second temporary holding member 259, and the thermoplastic adhesive 258 in this portion is once applied. Melt and cure. Thereafter, when the second temporary holding member 259 is peeled off from the first temporary holding member 253, as shown in FIG. 30, only the light emitting diode 252a to be transferred is selectively separated, and the second temporary holding member 259 is separated as shown in FIG. The image is transferred onto the temporary holding member 259.

  After the above selective separation, as shown in FIG. 31, a resin is applied so as to cover the transferred light emitting diode 252, and a resin layer 261 is formed. Further, as shown in FIG. 32, the thickness of the resin layer 261 is reduced by oxygen plasma or the like, and as shown in FIG. 33, a via hole 262 is formed at a position corresponding to the light emitting diode 252 by laser irradiation. For forming the via hole 262, an excimer laser, a harmonic YAG laser, a carbon dioxide laser, or the like can be used. At this time, the diameter of the via hole 262 is, for example, about 3 to 7 μm.

  Next, an anode electrode pad 263 connected to the p-electrode of the light emitting diode 252 via the via hole 262 is formed. The anode electrode pad 263 is formed of, for example, Ni / Pt / Au. FIG. 34 shows a state in which the light emitting diode 252 is transferred to the second temporary holding member 259, the via hole 262 on the anode electrode (p electrode) side is formed, and then the anode electrode pad 263 is formed.

  After the formation of the anode-side electrode pad 263, transfer to the third temporary holding member 264 is performed to form the cathode-side electrode on the opposite surface. The third temporary holding member 264 is also made of, for example, quartz glass. At the time of transfer, as shown in FIG. 35, an adhesive 265 is applied on the light emitting diode 252 on which the anode electrode pad 263 is formed, and further on the resin layer 261, and a third temporary holding member 264 is attached thereon. Combine. In this state, when the laser is irradiated from the back surface side of the second temporary holding member 259, the second temporary holding member 259 made of quartz glass and the polyimide formed on the second temporary holding member 259 are irradiated. The separation by laser ablation occurs at the interface of the separation layer 260, and the light emitting diode 252 and the resin layer 261 formed on the separation layer 260 are transferred onto the third temporary holding member 264. FIG. 36 shows a state where the second temporary holding member 259 is separated.

In forming the cathode side electrode, after the above-described transfer step, the release layer 260 and the extra resin layer 261 are removed by O ₂ plasma treatment shown in FIG. 37, and the contact semiconductor layer (n-electrode) of the light emitting diode 252 is formed. To expose. In a state where the light emitting diode 252 is held by the adhesive 265 of the temporary holding member 264, the back surface of the light emitting diode 252 is on the n-electrode side (cathode electrode side), and an electrode pad 266 is formed as shown in FIG. Then, the electrode pad 266 is electrically connected to the back surface of the light emitting diode 252.

  After that, the electrode pad 266 is patterned. At this time, the electrode pad on the cathode side can be, for example, about 60 μm square. As the electrode pad 266, a material such as a transparent electrode (ITO, ZnO-based) or Ti / Al / Pt / Au is used. In the case of a transparent electrode, light emission is not blocked even if the back surface of the light emitting diode 252 is largely covered, so that patterning accuracy is coarse, a large electrode can be formed, and the patterning process is facilitated.

  Next, the light emitting diodes 252 fixed by the resin layer 261 and the adhesive 265 are individually cut out to obtain the resin-formed chips. The cutting may be performed by, for example, laser dicing. FIG. 39 shows a cutting process by laser dicing. The laser dicing is performed by irradiating a laser line beam, and cuts the resin layer 261 and the adhesive 265 until the third temporary holding member 264 is exposed. By this laser dicing, each light-emitting diode 252 is cut out as a resin-formed chip of a predetermined size, and the process proceeds to a mounting process described later.

  In the mounting step, the light emitting diode 252 (resin-forming chip) is peeled off from the third temporary holding member 264 by a combination of mechanical means (element suction by vacuum suction) and laser ablation. FIG. 40 is a diagram showing that the light emitting diodes 252 arranged on the third temporary holding member 264 are picked up by the suction device 267. At this time, the suction holes 268 are opened in a matrix at the pixel pitch of the image display device so that a large number of the light emitting diodes 252 can be collectively sucked. The opening diameter at this time is, for example, about 100 μm in diameter and is opened in a matrix with a pitch of 600 μm, so that about 300 pieces can be sucked at a time. At this time, the member of the suction hole 268 is, for example, a member manufactured by Ni electroforming or a hole formed by etching a metal plate such as SUS. By controlling the suction chamber 269 to a negative pressure, the light emitting diode 252 can be sucked. At this stage, the light emitting diode 252 is covered with the resin layer 261 and the upper surface thereof is substantially flattened. For this reason, selective adsorption by the adsorption device 267 can be easily advanced.

  Note that the suction device 267 is provided with an element position deviation prevention means so that the light emitting diode 252 (resin forming chip) can be stably held at a fixed position when the element is suctioned by vacuum suction. Is preferred. FIG. 41 shows an example of the suction device 267 provided with the element displacement prevention means 270. In this example, the element position deviation prevention means 270 is formed as a positioning pin that comes into contact with the peripheral surface of the resin-formed chip, and this is used as a positioning pin (specifically, the resin layer 261 cut by laser dicing). (The cut surface of the light emitting diode 252), the suction device 267 and the resin forming chip (that is, the light emitting diode 252) are accurately aligned with each other. The cut surface of the resin layer 261 cut by the laser dicing has a taper of about 5 ° to 10 °, not a perfect vertical plane. Therefore, if a similar taper is provided to the positioning pin (element displacement prevention means 260), even if there is a slight displacement between the suction device 267 and the light emitting diode 252, it is quickly corrected. .

  When the light emitting diode 252 is peeled off, the element suction by the suction device 267 and the peeling of the resin-formed chip by laser ablation are combined so that the peeling proceeds smoothly. Laser ablation is performed by irradiating a laser from the back surface side of the third temporary holding member 264. Due to this laser ablation, separation occurs at the interface between the third temporary holding member 264 and the adhesive 265.

  FIG. 42 is a diagram showing a state where the light emitting diode 252 is transferred to the second substrate 271. The second substrate 271 is a wiring substrate having a wiring layer 272, and the adhesive layer 273 is applied to the second substrate 271 in advance when the light emitting diode 252 is mounted, and the adhesive layer 273 on the lower surface of the light emitting diode 252. Is cured, and the light emitting diodes 252 can be fixedly arranged on the second substrate 271. At the time of this mounting, the suction chamber 269 of the suction device 267 is in a high pressure state, and the connection state by suction between the suction device 267 and the light emitting diode 252 is released. The adhesive layer 273 can be made of a UV curable adhesive, a thermosetting adhesive, a thermoplastic adhesive, or the like. The position where the light-emitting diodes 252 are arranged on the second substrate 271 is apart from the arrangement on the temporary holding member 264. Energy for curing the resin of the adhesive layer 273 is supplied from the back surface of the second substrate 271. In the case of a UV-curable adhesive, only the lower surface of the light-emitting diode 252 is cured by infrared irradiation or the like in the case of a thermosetting adhesive by a UV irradiation device, and in the case of a thermoplastic adhesive, the adhesive is irradiated by infrared or laser. Is melted and bonded.

  FIG. 43 is a diagram illustrating a process of arranging the light emitting diodes 274 of other colors on the second substrate 271. When the mounting device 267 used in FIG. 40 or FIG. 41 is used as it is and the mounting position on the second substrate 271 is simply shifted to the position of the color, the pixel of a plurality of colors is kept at a constant pixel pitch. Can be formed. Here, the light emitting diode 252 and the light emitting diode 274 do not necessarily have to have the same shape. In FIG. 43, the red light-emitting diode 274 has a planar structure without a hexagonal pyramid GaN layer and is different in shape from the other light-emitting diodes 252, but at this stage, the light-emitting diodes 252 and 274 are already formed of resin. The chip is covered with the resin layer 261 and the adhesive 265 as a forming chip, and the same handling is realized despite the difference in element structure.

  Next, as shown in FIG. 44, an insulating layer 275 is formed to cover the resin-formed chip including the light emitting diodes 252 and 274. As the insulating layer 275, a transparent epoxy adhesive, a UV curable adhesive, polyimide, or the like can be used. After forming the insulating layer 275, a wiring forming step is performed. FIG. 45 is a diagram showing a wiring forming step. Openings 276, 277, 278, 279, 280, 281 are formed in the insulating layer 275, and wirings 282, 283 connecting the anode and cathode electrode pads of the light emitting diodes 252, 274 and the wiring layer 272 of the second substrate 271 are formed. FIG. The openings formed at this time, ie, the via holes, can be enlarged because the area of the electrode pads of the light emitting diodes 252 and 274 is increased, and the positional accuracy of the via holes is coarser than that of the via holes formed directly in each light emitting diode. Can be formed. For example, the via hole at this time can have a diameter of about 20 μm for an electrode pad of about 60 μm square. In addition, there are three types of via hole depths, one that connects to the wiring board, one that connects to the anode electrode, and one that connects to the cathode electrode. The depth of the via hole is controlled by the number of laser pulses, and the optimum depth is opened. .

  Thereafter, as shown in FIG. 46, a protective layer 285 is formed, a black mask 286 is formed, and the panel of the image display device is completed. The protective layer 285 at this time is the same as the insulating layer 275 of FIG. 40, and a material such as a transparent epoxy adhesive can be used. This protective layer 285 is cured by heating and completely covers the wiring. Thereafter, a driver panel is manufactured by connecting a driver IC from the wiring at the end of the panel.

  In the arrangement method of the light emitting elements as described above, the distance between the elements is already increased at the time when the light emitting diodes 252 are held by the temporary holding members 259 and 264, and the size of the light emitting elements is relatively increased by using the widened interval. Electrode pads 263, 266, etc. can be provided. Since wiring using the relatively large electrode pads 263 and 266 is performed, wiring can be easily formed even when the size of the final device is significantly larger than the element size. In the light emitting element arranging method of this example, the periphery of the light emitting diode 252 is covered with the cured resin layer 261 so that the electrode pads 263 and 266 can be formed with high accuracy by flattening, and the electrode pads 263 can be formed in a wider area than the element. , 266 can be extended, and when the transfer in the next second transfer step is advanced by the suction jig, the handling becomes easy.

  In the above-described embodiment, a display device in which red, blue, and green light-emitting diodes are combined is described as a display device. However, a diode having another emission wavelength can be used. The display device may emit four or more colors of light, and the light emitting element is not limited to the light emitting diode, but may be a semiconductor laser or a combination of a laser and an LED. That is, a dummy element that enables wavelength control can be formed in the semiconductor laser. Of course, the purpose of forming the dummy element is not limited to the control of the wavelength, but may be the purpose of protecting the element. In addition, the order of lamination of the substrates on which the semiconductor light-emitting diodes of each color are mounted can be changed.

FIG. 2 is a plan view showing an element layout for one pixel of the display device according to the first embodiment of the present invention. FIG. 3 is a plan view showing a pattern (upper side) of a selection mask of each light emitting diode and a plane pattern (lower side) of an element of the display device according to the first embodiment of the present invention. FIG. 3 is a cross-sectional view taken along the line III-III of FIG. 1 and is a cross-sectional view of the red light-emitting diode of the display device according to the first embodiment of the present invention. FIG. 4 is a cross-sectional view of the red light-emitting diode of the display device according to the first embodiment of the present invention, which is a cross-section taken along line IV-IV of FIG. 1. FIG. 9 is an exploded perspective view schematically illustrating one pixel portion of the display device according to the second embodiment of the present invention. FIG. 14 is a plan view illustrating an element layout for one pixel of a display device according to a third embodiment of the present invention. It is a top view showing a pattern (upper side) of a selection mask of each light emitting diode and a plane pattern (lower side) of an element of a light emitting diode of a display device of a third embodiment of the present invention. FIG. 7 is a cross-sectional view taken along a line VIII-VIII of FIG. 6 and is a cross-sectional view of a red light-emitting diode of a display device according to a third embodiment of the present invention. FIG. 13 is a cross-sectional view taken along line IX-IX of FIG. 6 and is a cross-sectional view of a red light emitting diode of the display device according to the third embodiment of the present invention. It is a top view showing the element layout for one pixel of the display of a 4th embodiment of the present invention. It is a top view showing the layout of the blue light emitting diode of the display of a 4th embodiment of the present invention. It is a top view showing the layout of the green light emitting diode of the display of a 4th embodiment of the present invention. It is a top view showing the layout of the red light emitting diode of the display of a 4th embodiment of the present invention. FIG. 12 is a cross-sectional view taken along line XIV-XIV of FIG. 11 and is a cross-sectional view of the blue light emitting diode of the display device according to the fourth embodiment of the present invention. FIG. 12 is a cross-sectional view taken along line XV-XV of FIG. 11, which is a cross-sectional view of the blue light emitting diode of the display device according to the fourth embodiment of the present invention. FIG. 3 is an exploded perspective view schematically showing a pixel arrangement of a display device of the present invention when light-emitting diodes of three colors are mounted on separate substrates and the respective substrates are superimposed. FIG. 3 is a cross-sectional view schematically showing a display device of the present invention when light-emitting diodes of three colors are mounted on separate substrates and the substrates are superimposed. FIG. 46 is a cross-sectional view showing a case where a condenser lens is provided in the display device shown in FIG. 45. FIG. 14 is a schematic diagram illustrating basic steps of a two-step enlargement transfer method used in a fifth embodiment of the present invention. It is a schematic perspective view of a resin formation chip. It is a schematic plan view of a resin-formed chip. It is an outline sectional view showing the joining process of the 1st member for temporary holding. It is a schematic sectional drawing which shows a UV adhesive hardening process. It is a schematic sectional drawing which shows a laser ablation process. It is a schematic sectional drawing which shows the isolation | separation process of a 1st board | substrate. It is a schematic sectional drawing which shows a Ga removal process. It is a schematic sectional drawing which shows an element isolation groove formation process. It is a schematic sectional drawing which shows the joining process of the 2nd member for temporary holding. FIG. 4 is a schematic sectional view showing a selective laser ablation and UV exposure process. FIG. 4 is a schematic cross-sectional view showing a light emitting diode selective separation step. It is a schematic sectional drawing which shows the embedding process with resin. It is a schematic sectional drawing which shows a resin layer thickness reduction process. It is a schematic sectional drawing which shows a via formation process. It is a schematic sectional drawing which shows an anode side electrode pad formation process. It is a schematic sectional drawing which shows a laser ablation process. It is an outline sectional view showing a separation process of the 2nd member for temporary holding. It is a schematic sectional drawing which shows a contact semiconductor layer exposure process. It is a schematic sectional drawing which shows a cathode side electrode pad formation process. It is a schematic sectional drawing which shows a laser dicing process. It is a schematic sectional drawing which shows the selective pick-up process by an adsorption | suction apparatus. It is a schematic sectional drawing which shows an example of the adsorption device provided with the element displacement prevention means. It is a schematic sectional drawing which shows the transfer process to a 2nd board | substrate. It is a schematic sectional drawing which shows the transfer process of another light emitting diode. It is a schematic sectional drawing which shows an insulating layer formation process. FIG. 4 is a schematic cross-sectional view illustrating a wiring forming step. It is a schematic sectional drawing which shows a protective layer and a black mask formation process.

Explanation of reference numerals

11R, 51R, 71R, 121, 211 Red light emitting diodes 11B, 51B, 71B, 101, 213 Blue light emitting diodes 11G, 51G, 71G, 111, 212 Green light emitting diodes 12R, 13B, 14G, 61, 62, 63, 72R, 73B, 74G Dummy element 10, 41, 42, 43, 70, 100B, 100G, 100R Sapphire substrate 202, 231 element (light emitting diode)
203, 232 Resin 204, 230 Resin forming chip 219 Spacer 220 Condensing lens 233, 234 Electrode pad 261 Resin layer 263, 266 Electrode pad

Claims (23)

A display device, wherein the semiconductor light emitting element is formed together with a dummy element for determining an emission wavelength. The display device according to claim 1, wherein the dummy elements are arranged around each of the semiconductor light emitting elements. The display device according to claim 1, wherein an emission wavelength is changed according to a distance between the dummy element and the semiconductor light emitting element. The display device according to claim 1, wherein an emission wavelength is changed according to a shape of the semiconductor light emitting element. The display device according to claim 1, wherein the semiconductor light emitting element is configured using a nitride semiconductor. The display device according to claim 1, wherein the nitride-based semiconductor is a GaN-based semiconductor. 2. The display device according to claim 1, wherein the semiconductor light emitting device is formed on a sapphire substrate or a silicon substrate. A display device, wherein at least two types of semiconductor light emitting elements having different emission wavelengths are formed on the same substrate by the same crystal growth layer, and the electrode on the substrate side is a common electrode. The display device according to claim 8, wherein the emission wavelengths are different from each other depending on at least one of a positional relationship between the semiconductor light emitting element and the dummy element and a shape of the semiconductor light emitting element. A display device, wherein a light transmitting region is formed in a region between devices between a plurality of semiconductor light emitting devices arranged on a base. 11. The display device according to claim 10, wherein a plurality of monochromatic semiconductor light emitting elements are provided on the base, and the bases are stacked in a light irradiation direction. The display device according to claim 11, wherein a wiring connected to the semiconductor light emitting element has a structure in which the wiring overlaps in the light irradiation direction. The display device according to claim 11, wherein the semiconductor light emitting elements have a structure that does not overlap in the light irradiation direction. 14. The display device according to claim 13, wherein a circuit unit is disposed in a space between the bases and formed on a rear side of the semiconductor light emitting element in a light irradiation direction. The display device according to claim 14, wherein the circuit unit includes a driving circuit. 14. The display device according to claim 13, wherein in the light irradiation direction, an optical element is provided on a substrate disposed in front corresponding to a semiconductor light emitting element on a substrate disposed behind. The display device according to claim 15, wherein the optical element is a lens. A semiconductor light emitting device comprising a dummy element having the same structure formed around the dummy element. 19. The semiconductor light emitting device according to claim 18, wherein an emission wavelength is changed according to a distance from the dummy device. 19. The semiconductor light emitting device according to claim 18, wherein an emission wavelength can be changed according to a shape. 19. The semiconductor light emitting device according to claim 18, wherein the semiconductor light emitting device is configured using a nitride-based semiconductor. 22. The semiconductor light emitting device according to claim 21, wherein said nitride semiconductor is a GaN semiconductor. 19. The semiconductor light emitting device according to claim 18, wherein the semiconductor light emitting device is formed on a sapphire substrate or a silicon substrate together with the dummy device.