JP2020013811A - Light-emitting element manufacturing method and light-emitting element - Google Patents

Abstract

To provide a micro LED capable of being collectively transferred to a wiring substrate and having a small warpage of the substrate, and a method of manufacturing the same.SOLUTION: On both surfaces of the semiconductor substrate 1, a SiC layer 2 for etching stop and for improving the crystallinity of a GaN epitaxial layer, a GaN buffer layer 3 for improving the crystallinity of the GaN epitaxial layer, a p-type GaN epitaxial layer 4, which is a GaN epitaxial layer, a quantum well layer 5, and an n-type GaN epitaxial layer 6 are formed.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a method for manufacturing a light-emitting element and a light-emitting element, and more specifically, a method for manufacturing a light-emitting element using collective transfer of a light-emitting element for each substrate or block, and a light-emitting element manufactured thereby It is about.

  Currently, liquid crystal display devices and organic light emitting diodes are used as display devices.

As a display device, an LED is currently widely used in the field of lighting. In recent years, a micro LED has been developed and has begun to be used as a display device.

JP 2018-10309A

  In a conventional micro LED, in order to improve the crystallinity of the LED, a very thick GaN buffer layer is first formed on the surface of the Si substrate as 5 to 10 μm, and a GaN epitaxial layer is formed thereon. A method of manufacturing an LED has been adopted. For this reason, the wafer is greatly warped due to the stress of the GaN buffer layer and the GaN epitaxial layer formed on the surface, and as a result, it is not possible to obtain a pattern in which the size and position accuracy of the micro LED are uniform, and the micro LED is wired. It was difficult to transfer them all at once to the substrate.

Further, as shown in Patent Literature 1, in the conventional technology, since a micro LED chip is transferred to a display substrate one chip at a time, a very large amount of work time is required, and the number of chips is large. Therefore, it has not been possible to make the alignment of all chips exactly the same.

  Therefore, the problem to be solved by the present invention is to provide a method for manufacturing a light-emitting element, in which the warpage of a semiconductor substrate in a photolithography step of the light-emitting element is minimized, and a micro LED chip for each semiconductor substrate or for each block. This is to realize batch transfer.

The method for manufacturing a light emitting device according to claim 1 of the present application
Forming a SiC layer and a GaN buffer layer on both surfaces of the semiconductor substrate in this order to reduce the warpage of the semiconductor substrate;
Forming a GaN epitaxial layer on the surface of the semiconductor substrate;
Forming a blue micro LED on the SiC layer and the GaN buffer layer on the surface of the semiconductor substrate;
Grinding the GaN buffer layer on the back surface of the semiconductor substrate, the SiC layer and the semiconductor substrate,
A step of transferring the micro LED to a display wiring substrate for each semiconductor substrate or each block,
Removing the remaining portion of the semiconductor substrate and the SiC layer and the GaN buffer layer on the surface of the semiconductor substrate in a state of being transferred to the display wiring substrate;
Forming an interlayer insulating layer between the blue micro LED patterns,
Forming a transparent conductive layer pattern on the exposed back surface of the blue micro LED,
The object is achieved by providing a method for manufacturing a light emitting device, comprising a step of forming a red fluorescent layer pattern, a green fluorescent layer pattern, and a transparent insulating layer pattern on the transparent conductive layer pattern.

  The method for manufacturing a light emitting device according to claim 1, wherein only a blue micro LED is formed on the surface of a semiconductor substrate, and then a red fluorescent layer pattern, a green fluorescent layer pattern, and a transparent insulating layer are respectively formed on the blue micro LED. A pattern is formed, and a red light emitting element, a green light emitting element, and a blue light emitting element are formed, and a light emitting element in which the red light emitting element, the green light emitting element, and the blue light emitting element are combined is completed. Here, the light emitting element, the red fluorescent layer pattern, the green fluorescent layer pattern, or the insulating layer pattern is formed on the blue micro LED, respectively, the formed red light emitting element, the green light emitting element, The blue light emitting device is a set. Then, a semiconductor substrate is prepared as shown in FIG. 1, and as shown in FIG. 2, an SiC layer for etching stop and for improving the crystallinity of the GaN epitaxial layer and a crystal of the GaN epitaxial layer are formed on both surfaces of the semiconductor substrate. A GaN buffer layer for improving the performance is formed. The reason why the SiC layer and the GaN buffer layer are formed on both surfaces of the semiconductor substrate is to reduce the warpage of the semiconductor substrate. When a p-type GaN layer as a GaN epitaxial layer, a quantum well layer, and an n-type GaN layer are formed on the surface of the semiconductor substrate as shown in FIG. 3, and the blue micro LED is manufactured as shown in FIG. In addition, since the SiC layer and the thick GaN buffer layer also exist on the back surface, warpage of the semiconductor substrate can be reduced. This solves the problem that the semiconductor substrate cannot be completely and flatly attracted to the exposure stage due to the large warpage of the semiconductor substrate in the photolithography process for forming the micro LED pattern as in the related art. Size and position accuracy can be formed with good control. Conventionally, since the GaN buffer layer and the GaN epitaxial layer are formed only on the surface of the semiconductor substrate, the wafer is largely warped. Therefore, even if the semiconductor substrate is forcibly adsorbed on the exposure stage, the warpage of the semiconductor substrate remains, and the micro LED There is a disadvantage that the accuracy of the pattern and position is not always uniform. For the above reasons, it has been conventionally difficult to align the micro LEDs in batch transfer for each semiconductor substrate or block. In the present invention, as shown in FIG. 5, after the blue micro LED pattern is formed, the stress on the front surface is released, but the stress due to the layer formed on the back surface remains. Therefore, as shown in FIGS. 6 and 7, the GaN buffer layer, the SiC layer, and the semiconductor substrate on the back surface of the semiconductor substrate are ground to release stress on the back surface. Further, the reason why the semiconductor substrate is ground is to make it easier to cut out a block including the blue micro LED. Then, as shown in FIG. 24, the blue micro LED is cut out for each block of the semiconductor substrate. Thereafter, as shown in FIG. 25, the block of the semiconductor substrate is inverted, a display wiring substrate is prepared as shown in FIG. 27, and the display wiring substrate is aligned with the display wiring substrate as shown in FIG. Electrodes to be joined together. FIG. 29 shows a state where the semiconductor substrate block provided with the blue micro LED is transferred to a display wiring substrate. As shown in FIG. 30, after the step of transferring the blue micro LED of each semiconductor block to the display wiring substrate, the entire transferred structure is covered with a resist layer or an insulating layer except for the back surface of the semiconductor substrate. Then, as shown in FIG. 31, the remaining portion of the semiconductor substrate and the SiC layer and the GaN buffer layer on the surface of the semiconductor substrate which are not necessary for the display device are removed by plasma etching and wet etching. Thereafter, as shown in FIG. 32, an interlayer insulating layer is formed between the blue micro LED patterns. Thereafter, a transparent conductive layer pattern is formed on the back surface of the blue micro LED exposed as shown in FIG. 33, and a red fluorescent layer pattern and a green fluorescent layer are formed on the transparent conductive layer pattern as shown in FIG. A display including a light emitting element including a red light emitting element, a green light emitting element, and a blue light emitting element by forming a pattern and a transparent insulating layer pattern, removing the interlayer insulating film on the extraction electrode as shown in FIG. The device can be completed.

  In this way, by using a substrate with less warpage, a blue micro LED is formed with high precision in the photolithography process, and the transfer efficiency is improved by collectively transferring the semiconductor substrate or block to the display wiring substrate. After the improvement, the display device can be completed. A voltage is applied between the lower electrode and the upper transparent electrode of the light emitting element including the red light emitting element, the green light emitting element, and the blue light emitting element, and the light emitting element including the red light emitting element, the green light emitting element, and the blue light emitting element. Can be adjusted to emit light of a desired color as a display device. Note that the fluorescent layer is formed on a blue LED and is widely used for emitting red and green light, and has an advantage that a light emitting element including a red light emitting element, a green light emitting element, and a blue light emitting element can be easily formed. .

The method for manufacturing a light emitting device according to claim 2 of the present application
Forming a SiC layer, a GaN buffer layer and a GaN epitaxial layer on both surfaces of the semiconductor substrate in this order, thereby reducing the warpage of the semiconductor substrate;
Forming a blue micro LED on the SiC layer and the GaN buffer layer on the surface of the semiconductor substrate;
Grinding the GaN epitaxial layer on the back surface of the semiconductor substrate, the GaN buffer layer, the SiC layer, and the semiconductor substrate;
A step of transferring the micro LED to a display wiring substrate for each semiconductor substrate or each block,
Removing the remaining portion of the semiconductor substrate and the SiC layer and the GaN buffer layer on the surface of the semiconductor substrate in a state of being transferred to the display wiring substrate;
Forming an interlayer insulating layer between the blue micro LED patterns,
Forming a transparent conductive layer pattern on the exposed back surface of the blue micro LED,
The above object is achieved by providing a method for manufacturing a light emitting device, comprising a step of forming a red fluorescent layer pattern, a green fluorescent layer pattern, and a transparent insulating layer pattern on the transparent conductive layer pattern.

  The method for manufacturing a light emitting device according to claim 2 of the present application includes forming only a blue micro LED on the surface of a semiconductor substrate, and then forming a red fluorescent layer pattern, a green fluorescent layer pattern, and a transparent insulating layer on the blue micro LED, respectively. A pattern is formed, and a red light emitting element, a green light emitting element, and a blue light emitting element are formed, and a light emitting element in which the red light emitting element, the green light emitting element, and the blue light emitting element are combined is completed. Here, the light emitting element, the red fluorescent layer pattern, the green fluorescent layer pattern, or the insulating layer pattern is formed on a blue micro LED, respectively, the formed red light emitting element, the green light emitting element, and It is a set of blue light emitting elements. Then, as shown in FIG. 1, the semiconductor substrate is prepared, and as shown in FIG. 8, an SiC layer for etching stop and for improving the crystallinity of the GaN epitaxial layer and a GaN epitaxial layer are formed on both surfaces of the semiconductor substrate. A GaN buffer layer for improving crystallinity, a p-type GaN layer as a GaN epitaxial layer, a quantum well layer, and an n-type GaN layer are formed. The reason for forming the SiC layer, the GaN buffer layer, and the GaN epitaxial layer on both surfaces of the semiconductor substrate is to reduce the warpage of the semiconductor substrate. As shown in FIG. 9, when manufacturing the blue micro LED, since the SiC layer, the thick GaN buffer layer, and the GaN epitaxial layer also exist on the back surface, the warpage of the semiconductor substrate can be reduced. As a result, it is possible to solve the problem that the semiconductor substrate cannot be completely and flatly attracted to the exposure stage due to the large warpage of the semiconductor substrate in the photolithography process for forming the micro LED pattern as in the related art. The size and positional accuracy of the pattern can be formed with good control. Conventionally, since the GaN buffer layer and the GaN epitaxial layer are formed only on the surface of the semiconductor substrate, the wafer is largely warped. Therefore, even if the semiconductor substrate is forcibly adsorbed on the exposure stage, the warpage of the semiconductor substrate remains, and the micro LED There is a disadvantage that the accuracy of the pattern and position is not always uniform. For the above reasons, it has been conventionally difficult to align the micro LEDs in batch transfer for each semiconductor substrate or block. In the present invention, as shown in FIG. 10, after the blue micro LED pattern is formed, the stress on the front surface is released, but the stress due to the layer formed on the back surface remains. Therefore, as shown in FIGS. 11 and 12, the GaN epitaxial layer, the GaN buffer layer, the SiC layer, and the semiconductor substrate on the back surface of the semiconductor substrate are ground to release stress on the back surface. Further, the reason why the semiconductor substrate is ground is to make it easier to cut out a block including the blue micro LED. Then, as shown in FIG. 24, the blue micro LED is cut out for each block of the semiconductor substrate. Thereafter, as shown in FIG. 25, the block of the semiconductor substrate is inverted, a display wiring substrate is prepared as shown in FIG. 27, and the display wiring substrate is aligned with the display wiring substrate as shown in FIG. Electrodes to be joined together. FIG. 29 shows a state where the semiconductor substrate block provided with the blue micro LED is transferred to the display wiring substrate. As shown in FIG. 30, after the step of transferring the blue micro LEDs of each semiconductor block to the display wiring substrate, the entire transferred structure is covered with a resist layer or an insulating layer except for the back surface of the semiconductor substrate. Then, as shown in FIG. 31, the remaining portion of the semiconductor substrate and the SiC layer and the GaN buffer layer on the surface of the semiconductor substrate which are not necessary for the display device are removed by plasma etching and wet etching. Thereafter, as shown in FIG. 32, an interlayer insulating layer is formed between the blue micro LED patterns. Thereafter, a transparent conductive layer pattern is formed on the back surface of the blue micro LED exposed as shown in FIG. 33, and a red fluorescent layer pattern and a green fluorescent layer are formed on the transparent conductive layer pattern as shown in FIG. A display including a light emitting element including a red light emitting element, a green light emitting element, and a blue light emitting element by forming a pattern and a transparent insulating layer pattern, removing the interlayer insulating film on the extraction electrode as shown in FIG. The device can be completed.

  In this way, by using a substrate with less warpage, a blue micro LED is formed with high precision in the photolithography process, and the transfer efficiency is improved by collectively transferring the semiconductor substrate or block to the display wiring substrate. After the improvement, the display device can be completed. A voltage is applied between the lower electrode and the upper transparent electrode of the light emitting element including the red light emitting element, the green light emitting element, and the blue light emitting element, and the light emitting element including the red light emitting element, the green light emitting element, and the blue light emitting element. Can be adjusted to emit light of a desired color as a display device. Note that the fluorescent layer is formed on a blue LED and is widely used for emitting red and green light, and has an advantage that a light emitting element including a red light emitting element, a green light emitting element, and a blue light emitting element can be easily formed. .

The method of manufacturing a light emitting device according to claim 3 of the present application
Forming a GaN layer buffer on both surfaces of the semiconductor substrate to reduce the warpage of the semiconductor substrate;
Forming a GaN epitaxial layer on the surface of the semiconductor substrate,
Forming a blue micro LED on the GaN buffer layer on the surface of the semiconductor substrate;
Grinding the GaN buffer layer and the semiconductor substrate on the back surface of the semiconductor substrate,
Transferring the blue micro LED to a display wiring board for each semiconductor substrate or block;
Removing the remaining portion of the semiconductor substrate and the GaN layer on the surface of the semiconductor substrate while being transferred to the display wiring substrate;
Forming an interlayer insulating layer between the blue micro LED patterns,
The object is achieved by providing a method for manufacturing a light emitting device, comprising a step of forming a red fluorescent layer pattern, a green fluorescent layer pattern, and a transparent insulating layer pattern on the transparent conductive layer pattern.

  The method of manufacturing a light emitting device according to claim 3, wherein only a blue micro LED is formed on the surface of the semiconductor substrate, and then a red fluorescent layer pattern, a green fluorescent layer pattern, and a transparent insulating layer are respectively formed on the blue micro LED. A pattern is formed, and a red light emitting element, a green light emitting element, and a blue light emitting element are formed, and a light emitting element in which the red light emitting element, the green light emitting element, and the blue light emitting element are combined is completed. Here, the light emitting element, the red fluorescent layer pattern, the green fluorescent layer pattern, and the insulating layer pattern are respectively formed on the blue micro LED, the formed red light emitting element, the green light emitting element, The blue light emitting device is a set. Then, a semiconductor substrate is prepared as shown in FIG. 1, and a GaN buffer layer for improving the crystallinity of the GaN epitaxial layer is formed on both surfaces of the semiconductor substrate as shown in FIG. The reason why the GaN buffer layers are formed on both surfaces of the semiconductor substrate is to reduce the warpage of the semiconductor substrate. A p-type GaN layer as the GaN epitaxial layer, a quantum well layer, and an n-type GaN layer are formed on the surface of the semiconductor substrate as shown in FIG. 14, and the blue micro LED is manufactured as shown in FIG. In this case, since the thick GaN buffer layer also exists on the back surface, the warpage of the semiconductor substrate can be reduced. As a result, it is possible to solve the problem that the semiconductor substrate cannot be completely and flatly attracted to the exposure stage due to the large warpage of the semiconductor substrate in the photolithography process for forming the micro LED pattern as in the related art. The size and positional accuracy of the pattern can be formed with good control. Conventionally, since the GaN buffer layer and the GaN epitaxial layer are formed only on the surface of the semiconductor substrate, the wafer is largely warped. Therefore, even if the semiconductor substrate is forcibly adsorbed on the exposure stage, the warpage of the semiconductor substrate remains, and the micro LED There is a disadvantage that the accuracy of the pattern and position is not always uniform. For the above reasons, it has been conventionally difficult to align the micro LEDs in batch transfer for each semiconductor substrate or block. In the present invention, as shown in FIG. 16, after the blue micro LED pattern is formed, the stress on the front surface is released, but the stress due to the layer formed on the back surface remains. Therefore, as shown in FIGS. 17 and 18, the GaN buffer layer on the back surface of the semiconductor substrate and the semiconductor substrate are ground to release stress on the back surface. Further, the reason why the semiconductor substrate is ground is to make it easier to cut out a block including the blue micro LED. Then, as shown in FIG. 24, the blue micro LED is cut out for each block of the semiconductor substrate. Thereafter, as shown in FIG. 26, the block of the semiconductor substrate is inverted, a display wiring board is prepared as shown in FIG. 27, and the display wiring board is aligned with the display wiring board as shown in FIG. Electrodes to be joined together. FIG. 29 shows a state where the semiconductor substrate block provided with the blue micro LED is transferred to the display wiring substrate. As shown in FIG. 30, after the step of transferring the blue micro LED of each semiconductor block to the display wiring substrate, the entire transferred structure is covered with a resist layer or an insulating layer except for the back surface of the semiconductor substrate. Then, as shown in FIG. 31, the remaining portion of the semiconductor substrate and the GaN buffer layer on the surface of the semiconductor substrate which are not necessary for the display device are removed by plasma etching and wet etching. Thereafter, as shown in FIG. 32, an interlayer insulating layer is formed between the blue micro LED patterns. Thereafter, a transparent conductive layer pattern is formed on the exposed back surface of the blue micro LED as shown in FIG. 33, and a red fluorescent layer pattern and a green fluorescent layer pattern are formed on the transparent conductive layer pattern as shown in FIG. And a transparent insulating layer pattern, and the interlayer insulating film on the lead-out electrode is removed as shown in FIG. 35, and a display device provided with a red light emitting element, a green light emitting element, and a blue light emitting element Can be completed.

  In this way, by using a substrate with less warpage, a blue micro LED is formed with high precision in the photolithography process, and the transfer efficiency is improved by collectively transferring the semiconductor substrate or block to the display wiring substrate. After the improvement, the display device can be completed. A voltage is applied between the lower electrode and the upper transparent electrode of the light emitting element including the red light emitting element, the green light emitting element, and the blue light emitting element, and the light emitting element including the red light emitting element, the green light emitting element, and the blue light emitting element. Can be adjusted to emit light of a desired color as a display device. Note that the fluorescent layer is formed on a blue LED and is widely used for emitting red and green light, and has an advantage that a light emitting element including a red light emitting element, a green light emitting element, and a blue light emitting element can be easily formed. .

The method for manufacturing a light emitting device according to claim 4 of the present application
Forming a GaN layer buffer and a GaN epitaxial layer on both surfaces of the semiconductor substrate in this order to reduce the warpage of the semiconductor substrate;
Forming a blue micro LED on the GaN buffer layer on the surface of the semiconductor substrate;
Grinding the GaN epitaxial layer on the back surface of the semiconductor substrate, a GaN buffer layer, and the semiconductor substrate;
Transferring the blue micro LED to a display wiring board for each semiconductor substrate or block;
Removing the remaining portion of the semiconductor substrate in a state transferred to the display wiring substrate and the GaN buffer layer on the surface of the semiconductor substrate;
Forming an interlayer insulating layer between the blue micro LED patterns,
Forming a transparent conductive layer pattern on the exposed back surface of the blue micro LED,
The above object is achieved by providing a method for manufacturing a light emitting device comprising a step of forming a red fluorescent layer pattern, a green fluorescent layer pattern, and a transparent insulating layer pattern on the transparent conductive layer pattern.

  The method of manufacturing a light emitting device according to claim 4, wherein only a blue micro LED is formed on the surface of the semiconductor substrate, and then a red fluorescent layer pattern, a green fluorescent layer pattern, and a transparent insulating layer are respectively formed on the blue micro LED. A pattern is formed, and a red light emitting element, a green light emitting element, and a blue light emitting element are formed, and a light emitting element in which the red light emitting element, the green light emitting element, and the blue light emitting element are combined is completed. Here, the light emitting element, the red fluorescent layer pattern, the green fluorescent layer pattern, or the insulating layer pattern is formed on the blue micro LED, respectively, the formed red light emitting element, the green light emitting element, The blue light emitting device is a set. Then, a semiconductor substrate is prepared as shown in FIG. 1, and as shown in FIG. 19, a GaN buffer layer for improving the crystallinity of the GaN epitaxial layer and a p-type GaN A layer, a quantum well layer, and an n-type GaN layer. The reason why the GaN buffer layer and the GaN epitaxial layer are formed on both surfaces of the semiconductor substrate is to reduce the warpage of the semiconductor substrate. As shown in FIG. 20, when manufacturing the blue micro LED, since the thick GaN buffer layer and the GaN epitaxial layer also exist on the back surface, the warpage of the semiconductor substrate can be reduced. As a result, it is possible to solve the problem that the semiconductor substrate cannot be completely and flatly attracted to the exposure stage due to the large warpage of the semiconductor substrate in the photolithography process for forming the micro LED pattern as in the related art. The size and positional accuracy of the pattern can be formed with good control. Conventionally, since the GaN buffer layer and the GaN epitaxial layer are formed only on the surface of the semiconductor substrate, the wafer is largely warped. Therefore, even if the semiconductor substrate is forcibly adsorbed on the exposure stage, the warpage of the semiconductor substrate remains, and the micro LED There is a disadvantage that the accuracy of the pattern and position is not always uniform. For the above reasons, it has been conventionally difficult to align the micro LEDs in batch transfer for each semiconductor substrate or block. In the present invention, as shown in FIG. 21, after the blue micro LED pattern is formed, the stress on the front surface is released, but the stress due to the layer formed on the back surface remains. Therefore, as shown in FIGS. 22 and 23, the GaN epitaxial layer, the GaN buffer layer, and the semiconductor substrate on the back surface of the semiconductor substrate are ground to release the stress on the back surface. Further, the reason why the semiconductor substrate is ground is to make it easier to cut out a block including the blue micro LED. Then, as shown in FIG. 24, the blue micro LED is cut out for each block of the semiconductor substrate. Thereafter, as shown in FIG. 26, the block of the semiconductor substrate is inverted, a display wiring board is prepared as shown in FIG. 27, and the display wiring board is aligned with the display wiring board as shown in FIG. Electrodes to be joined together. FIG. 29 shows a state in which the semiconductor substrate block provided with the blue micro LEDs is transferred to the display wiring substrate. As shown in FIG. 30, after the step of transferring the blue micro LED of each semiconductor block to the display wiring substrate, the entire transferred structure is covered with a resist layer or an insulating layer except for the back surface of the semiconductor substrate. Then, as shown in FIG. 31, the remaining portion of the semiconductor substrate and the GaN buffer layer on the surface of the semiconductor substrate which are not necessary for the display device are removed by plasma etching and wet etching. Thereafter, as shown in FIG. 32, an interlayer insulating layer is formed between the blue micro LED patterns. Thereafter, a transparent conductive layer pattern is formed on the exposed back surface of the blue micro LED as shown in FIG. 33, and a red fluorescent layer pattern and a green fluorescent layer pattern are formed on the transparent conductive layer pattern as shown in FIG. And a transparent insulating layer pattern, and the interlayer insulating film on the lead-out electrode is removed as shown in FIG. 35, and a display device provided with a red light emitting element, a green light emitting element, and a blue light emitting element Can be completed.

  In this way, by using a substrate with less warpage, a blue micro LED is formed with high precision in the photolithography process, and the transfer efficiency is improved by collectively transferring the semiconductor substrate or block to the display wiring substrate. After the improvement, the display device can be completed. A voltage is applied between the lower electrode and the upper transparent electrode of the light emitting element including the red light emitting element, the green light emitting element, and the blue light emitting element, and the light emitting element including the red light emitting element, the green light emitting element, and the blue light emitting element. Can be adjusted to emit light of a desired color as a display device. Note that the fluorescent layer is formed on a blue LED and is widely used for emitting red and green light, and has an advantage that a light emitting element including a red light emitting element, a green light emitting element, and a blue light emitting element can be easily formed. .

The method for manufacturing a light emitting device according to claim 5 of the present application is
The object is achieved by providing the method for manufacturing a light emitting device according to any one of claims 1 to 4, wherein the semiconductor substrate is a Si substrate.

  Since a Si substrate is widely used in a semiconductor process, a photolithography step, a grinding step, a transfer step, and an etching step used in a light emitting element process can be easily performed, and a light emitting element can be easily formed.

The method for manufacturing a light emitting device according to claim 6 of the present application
The object is achieved by providing the method for manufacturing a light emitting device according to any one of claims 1 to 4, wherein the semiconductor substrate is a sapphire substrate.

  Since the sapphire substrate is widely used in the LED process, the photolithography step, the grinding step, the transfer step, and the etching step used in the process of the light emitting element can be easily performed, and the light emitting element can be easily formed.

The method for manufacturing a light emitting device according to claim 7 of the present application
5. The method according to claim 1, wherein the display wiring substrate includes a wiring structure that enables red, green, and blue light emission to be independently controlled. 6. The above problem has been solved.

  The display wiring board can independently control the red, green, and blue light-emitting elements, so that the color display device can be operated.

The light emitting device according to claim 8 of the present application is:
The above object is achieved by providing a light emitting device manufactured by the method for manufacturing a light emitting device according to any one of claims 1 to 4.

  The light emitting device according to claim 8 of the present application performs the process according to any one of claims 1 to 4, and is a red light emitting device using a blue micro LED, a green light emitting device, and a blue light emitting device. A large number of sets can be provided, their emission intensity can be adjusted, and a color display device can be operated.

  According to the present invention, a SiC layer and a GaN buffer layer, a SiC layer and a GaN buffer layer and a GaN epitaxial layer, a GaN buffer layer, a GaN buffer layer and a GaN epitaxial layer are formed on both surfaces of a semiconductor substrate, respectively. Since the warpage of the light emitting device can be reduced, the size of the light emitting device and the position of the light emitting device in the semiconductor substrate in the photolithography process can be formed with high precision by eliminating the adsorption obstacle in the manufacturing process of the light emitting device.

  Next, the semiconductor substrate having the light-emitting element is cut into a square and a rectangular block. Since the dimensions and the position of the light-emitting element are accurate, the block including the light-emitting element can be easily aligned with the display wiring board. By being able to collectively transfer the micro LEDs to the display wiring board every time, the working time can be greatly reduced as compared with the method of transferring the micro LEDs one by one.

  And, by transferring the red, green, and blue light emitting elements using the blue micro LED to the display wiring board, the red, green, and blue light emitting elements using the blue micro LED that can emit any color are included. A display device can be realized.

Further, by simply combining a plurality of blocks having light-emitting elements including red, green, and blue light-emitting elements, a display device including light-emitting elements including red, green, and blue light-emitting elements on a large substrate can be easily formed. There are advantages that can be realized. The display device including the light emitting element can be used for automobiles, aircraft, robots, IOTs, communication devices, health appliances, security appliances, and the like.

4 shows a step of preparing a Si substrate. The state after the step of forming a SiC layer and a GaN buffer layer on both surfaces of a Si substrate to form a blue micro LED is shown. This figure shows a state after a process of forming a SiC layer and a GaN buffer layer on both surfaces of a Si substrate and then forming a GaN epitaxial layer only on the surface to form a blue micro LED. 5 shows a step of forming a resist pattern on a GaN epitaxial layer on the surface of a Si substrate to form a blue micro LED. The dotted line indicates the area where the blue micro LED is formed. The state after the step of forming the blue micro LED on the surface of the Si substrate is shown. 3 shows a step of grinding the GaN buffer layer, the SiC layer, and the Si substrate on the back surface after the step of forming the blue micro LED on the surface of the Si substrate. The area surrounded by the dotted line is the area to be ground. The state after the step of grinding the GaN buffer layer, SiC layer, and Si on the back surface to form a blue micro LED is shown. The state after the step of forming a SiC layer, a GaN buffer layer, and a GaN epitaxial layer on both surfaces of a Si substrate to form a blue micro LED is shown. 5 shows a step of forming a resist pattern on a GaN epitaxial layer on the surface of a Si substrate to form a blue micro LED. The dotted line indicates the area where the blue micro LED is formed. The state after the step of forming the blue micro LED on the surface of the Si substrate is shown. After the step of forming the blue micro LED on the surface of the Si substrate, a step of grinding the GaN epitaxial layer, GaN buffer layer, SiC layer, and Si substrate on the back surface is shown. The area surrounded by the dotted line is the area to be ground. The state after the step of grinding the GaN epitaxial layer, GaN buffer layer, SiC layer, and Si on the back surface is shown. The state after the step of forming a GaN buffer layer on both surfaces of a Si substrate to form a blue micro LED is shown. This figure shows a state after forming a GaN buffer layer on both surfaces of a Si substrate and then forming a GaN epitaxial layer only on the surface in order to form a blue micro LED. 5 shows a step of forming a resist pattern on a GaN epitaxial layer on the surface of a Si substrate to form a blue micro LED. The dotted line indicates the area where the blue micro LED is formed. The state after the step of forming the blue micro LED on the surface of the Si substrate is shown. After the step of forming the blue micro LED on the surface of the Si substrate, a step of grinding the GaN buffer layer on the back surface and the Si substrate is shown. The area surrounded by the dotted line is the area to be ground. The state after the step of grinding the GaN buffer layer on the back surface and Si is shown. The state after the step of forming a GaN buffer layer and a GaN epitaxial layer on both surfaces of a Si substrate to form a blue micro LED is shown. 5 shows a step of forming a resist pattern on a GaN epitaxial layer on the surface of a Si substrate to form a blue micro LED. Dotted lines indicate regions where micro LEDs are formed. The state after the step of forming the blue micro LED on the surface of the Si substrate is shown. After the step of forming the blue micro LED on the surface of the Si substrate, the step of grinding the GaN epitaxial layer, the GaN buffer layer, and the Si substrate on the back surface is shown. The area surrounded by the dotted line is the area to be ground. The state after the step of grinding the GaN epitaxial layer, GaN buffer layer, and Si on the back surface is shown. The process which cuts the Si substrate in which the blue micro LED was formed into a rectangular block is shown. 5 shows a step of inverting a block having a SiC layer and forming a blue micro LED on the surface of a Si substrate in order to join the block to a display wiring substrate. A step of inverting a block having no SiC layer and having a blue micro LED formed on the surface of a Si substrate for bonding to a display wiring substrate is shown. 4 shows a step of preparing a display wiring substrate. The process of aligning the blue micro LED on the Si substrate with the display wiring substrate and transferring the Si substrate block including the micro LED to the display wiring substrate is shown. The state after the step of bonding the Si substrate block on which the blue micro LED is formed and the display wiring substrate of the micro LED is shown. After bonding the Si substrate block on which the red, green, and blue display micro LEDs are formed and the display wiring substrate of the micro LED, the state after the step of forming a resist film or the like other than on the back surface of the Si substrate block is shown. Show. After the step of bonding the Si substrate block on which the blue micro LED is formed and the display wiring substrate of the micro LED, the Si substrate is dry-etched and wet-etched, and the SiC layer and the GaN buffer layer or the GaN buffer layer are dry-etched and wet-etched. This shows the state after the step of performing the above. The state after the step of forming an interlayer insulating film between the micro LED having a structure in which the Si substrate block on which the blue micro LED is formed and the micro LED for a display wiring board are joined is shown. After bonding the Si substrate block on which the blue micro LED is formed and the wiring substrate for display of the micro LED, forming an interlayer insulating film between the micro LEDs, and then forming a transparent electrode and a transparent wiring on the blue micro LED The state of is shown. A red fluorescent layer pattern, a green fluorescent layer pattern, and a transparent insulating layer pattern are formed on a transparent electrode and a transparent wiring on a blue micro LED, and a light emitting element including a red light emitting element, a green light emitting element, and a blue light emitting element 2 shows the state after the step of forming. The state after the step of forming the light emitting element including the red light emitting element, the green light emitting element, and the blue light emitting element and then removing the interlayer insulating film on the extraction electrode is shown.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each of the drawings, the same portions are denoted by the same reference numerals.
(Embodiment 1)

  In this embodiment, instead of forming red, green, and blue LEDs, a blue micro LED 13 is formed, a transparent electrode wiring 48 is formed thereon, and a red fluorescent layer 51 pattern and a green fluorescent layer are formed thereon. 52, and a transparent insulating layer pattern 53 are formed to form a red light emitting element 61, a green light emitting element 62, and a blue light emitting element 63, respectively. , And a large number of light-emitting elements, each of which is a set of blue light-emitting elements 63, are developed on the substrate 1 so as to function as a color display device.

  As shown in FIG. 1, a semiconductor substrate 1 is prepared, and as shown in FIG. 2, a 50-200 nm SiC layer 2 is formed on both surfaces of the semiconductor substrate 1 by a low-pressure CVD method (not shown). A GaN buffer layer 3 of 10 to 10 μm is formed, and a p-type GaN layer 4 of 0.3 to 2 μm and quantum well layers 5 and 0.3 of 10 to 100 nm are formed on the surface of the semiconductor substrate 1 as shown in FIG. A step of epitaxially growing an n-type GaN layer 6 having a thickness of about 2 μm to form a structure in which the semiconductor substrate 1 has less warpage before forming a blue micro LED will be described. The reason why the epitaxial layer is formed on the surface of the semiconductor substrate 1 is to consider the use of a commercially available epitaxial device.

In FIG. 4, an electrode layer 7 is further formed on the n-type epitaxial layer 6, and a resist pattern 8 for forming a blue micro LED is formed thereon. FIG. 5 shows a step of forming the blue micro LED 13 on the surface of the semiconductor substrate 1. Each micro LED includes a p-type GaN layer 4 of 0.3 to 2 μm, a quantum well layer 5 of 10 to 100 nm, an n-type GaN layer 6 of 0.3 to 2 μm, and an electrode layer 7 of 500 to 2 μm. It has become. The adjustment of the In concentration in the quantum well layer may be performed by selective ion implantation or by selective epitaxial growth. In this manner, a large number of sets of micro LEDs, each set of three blue micro LEDs, are developed on the semiconductor substrate 1.

FIG. 6 shows a step of grinding the back surface of the GaN buffer layer 3, the SiC layer 2, and the back surface of the conductive substrate 1 with a grinder to reduce the remaining thickness of the semiconductor substrate 1 to 50 to 300 μm. The dotted line is the part to be ground. FIG. 7 shows the back surface of the GaN buffer layer 3, the SiC layer 2, and the back surface of the conductive substrate 1 ground by a grinder, and the remaining thickness of the semiconductor substrate 1 is ground to a thickness of 50 to 300 μm. The state of is shown.

FIG. 24 shows a step of cutting the semiconductor substrate 1 having the blue micro LEDs 13 into blocks 30 in order to transfer the semiconductor substrate 1 to the display wiring substrate 40.

FIG. 25 shows a step of inverting the semiconductor substrate 1 provided with the blue micro LEDs 13 to transfer the semiconductor substrate 1 to the display wiring substrate 40.

FIG. 27 shows a display wiring board 40 having a wiring for driving the blue micro LED 13. The display wiring board includes a red light emitting element embedded wiring 41, a green light emitting element embedded wiring 42, and a blue light emitting element. The device includes an embedded wiring 43, a contact electrode for a red light emitting element 44, a contact electrode for a green light emitting element 45, a contact electrode for a blue light emitting element 46, and an extraction electrode 47.

  FIG. 28 shows a transfer step of aligning the block 30 of the semiconductor substrate 1 provided with the blue micro LED 13 with the display wiring substrate 40 and joining the corresponding electrodes of both substrates. A conductive adhesive or solder (not shown) is formed on the electrode surface on the surface of the display wiring substrate 40. Here, as indicated by the dashed line arrow, one of the three sets of blue micro LEDs 13 and the contact electrode 44 for the red light emitting element, the other of the set of three blue micro LEDs 13 and the green light emitting element contact electrode 45, Another one of the set of three blue micro LEDs 13 is joined to the blue light emitting element contact electrode 46 after being aligned.

FIG. 29 shows a state after the step of joining the block 30 of the semiconductor substrate 1 and the display wiring substrate 40.

FIG. 30 shows a step of applying a block other than the bonded block 30 of the semiconductor substrate 1 and the block 30 of the semiconductor substrate 1 having the structure of the display wiring board 40 with a resist (or an organic material or an insulating layer) 21. When etching 30, other parts are protected so that a wet etching solution or ions or radicals for plasma etching do not enter inside. Here, the resist 21 covering the block 30 of the semiconductor substrate 1 is exposed to ultraviolet light, developed, and exposed.
When plasma etching is used, portions other than the block of the semiconductor substrate 1 are covered with an insulating layer, for example, an SOG film.

  FIG. 31 shows a state after the step of selectively wet etching the semiconductor substrate 1 with TMAH or TMAH + ammonium persulfate, removing the SiC layer 2 and the buffer layer 3 on the front side by plasma etching, and removing the peripheral resist layer 21. Indicates the status. When performing selective dry etching by SF6, the SOG film is removed after the etching.

  FIG. 32 shows a state after the step of forming the interlayer insulating layer 22 between the patterns of the blue micro LEDs 13.

FIG. 33 shows a state after the step of forming the transparent electrode wiring 48 on the surface of the blue micro LED 13. The transparent electrode wiring 48 may be formed directly using photolithography on the display device having the blue micro LED 13 shown in FIG. 32, or the electrode wiring structure 48 may be formed on another transparent substrate (not shown) in advance. Alternatively, this transparent substrate may be bonded to a display device. Normally, the electrode wiring structure 48 is used as the ground, but the present invention is not limited to this.

  In FIG. 34, a red fluorescent layer pattern, a green fluorescent layer pattern, and an insulating layer pattern that emits blue light as they are are formed on the transparent electrode wiring, and a red light emitting element 61, a green light emitting element 62, and a blue light emitting element are formed. This shows the state after the step of forming 63.

FIG. 35 shows a state after the step of removing the interlayer insulating layer above the extraction electrode 47 and connecting to a power supply (not shown).

The display device including the red light emitting element 61, the green light emitting element 62, and the light emitting element including the blue light emitting element obtained in this manner is connected to the red light emitting element embedded wiring 41 of the display wiring board 40 and the green light emitting element. A voltage is applied between the transparent wiring 48 on the surface of the light emitting element composed of the embedded wiring 42 for blue light emitting element, the embedded wiring 43 for blue light emitting element, the red light emitting element 61, the green light emitting element 62, and the blue light emitting element. To function as a display device that generates various luminescent colors.
(Embodiment 2)

  In this embodiment, instead of forming red, green, and blue LEDs, a blue micro LED 13 is formed, a transparent electrode wiring 48 is formed thereon, and a red fluorescent layer 51 pattern and a green fluorescent layer are formed thereon. 52, and a transparent insulating layer pattern 53 are formed to form a red light emitting element 61, a green light emitting element 62, and a blue light emitting element 63, respectively. , And a large number of light-emitting elements, each of which is a set of blue light-emitting elements 63, are developed on the substrate 1 so as to function as a color display device.

  As shown in FIG. 1, a semiconductor substrate 1 is prepared, and as shown in FIG. 8, a 50-200 nm SiC layer 2 is formed on both surfaces of the semiconductor substrate 1 by a low-pressure CVD method (not shown). A GaN buffer layer 3 of 10 to 10 μm is formed, and a p-type GaN layer 4 of 0.3 to 2 μm, a quantum well layer 5 of 10 to 100 nm, and an n-type GaN layer 6 of 0.3 to 2 μm are epitaxially grown. A step of forming a structure in which the warpage of the semiconductor substrate 1 is reduced before forming an LED will be described.

In FIG. 9, an electrode layer 7 is further formed on the n-type epitaxial layer 6, and a resist pattern 8 for forming a micro LED is formed thereon. FIG. 10 shows a step of forming the blue micro LED 13 on the surface of the semiconductor substrate 1. Each micro LED includes a p-type GaN layer 4 of 0.3 to 2 μm, a quantum well layer 5 of 10 to 100 nm, an n-type GaN layer 6 of 0.3 to 2 μm, and an electrode layer 11 of 500 to 2 μm. It has become. The In concentration of the quantum well layer may be adjusted by selective ion implantation or by selective epitaxial growth. In this manner, a large number of sets of micro LEDs, each set of three blue micro LEDs, are developed on the semiconductor substrate 1.

FIG. 11 shows that the back surface of the n-type GaN layer 6, the quantum well layer 5, the p-type GaN layer 4, the GaN buffer layer 3, the SiC layer 2, and the back surface of the semiconductor substrate 1 are ground by a grinder, The step of setting the remaining thickness of one substrate to 50 to 300 μm will be described. The dotted line is the part to be ground. FIG. 12 shows that the back surface of the n-type GaN layer 6, the quantum well layer 5, the p-type GaN layer 4, the GaN buffer layer 3, the SiC layer 2, and the back surface of the semiconductor substrate 1 are ground by a grinder, 1 shows a state after the step of grinding until the thickness of No. 1 reaches a thickness of 50 to 300 μm.

FIG. 24 shows a step of cutting the semiconductor substrate 1 having the blue micro LEDs 13 into blocks 30 in order to transfer the semiconductor substrate 1 to the display wiring substrate 40.

FIG. 25 shows a step of inverting the semiconductor substrate 1 provided with the blue micro LEDs 13 to transfer the semiconductor substrate 1 to the display wiring substrate 40.

FIG. 27 shows a display wiring board 40 having wiring for driving a blue micro LED. In the display wiring board, a red light emitting element embedded wiring 41, a green light emitting element embedded wiring 42, and a blue light emitting element are provided. The device includes an embedded wiring 43, a contact electrode for a red light emitting element 44, a contact electrode for a green light emitting element 45, a contact electrode for a blue light emitting element 46, and an extraction electrode 47.

  FIG. 28 shows a transfer step of aligning the block 30 of the semiconductor substrate 1 provided with the blue micro LED with the display wiring substrate 40 and joining the corresponding electrodes of both substrates. A conductive adhesive or solder (not shown) is formed on the electrode surface on the surface of the display wiring substrate 40. Here, as indicated by the dashed line arrow, one of the three sets of blue micro LEDs 13 and the contact electrode 44 for the red light emitting element, the other of the set of three blue micro LEDs 13 and the green light emitting element contact electrode 45, Another one of the set of three blue micro LEDs 13 is joined to the blue light emitting element contact electrode 46 after being aligned.

FIG. 29 shows a state after the step of joining the block 30 of the semiconductor substrate 1 and the display wiring substrate 40.

FIG. 30 shows a step of applying a block other than the bonded block 30 of the semiconductor substrate 1 and the block 30 of the semiconductor substrate 1 having the structure of the display wiring board 40 with a resist (or an organic material or an insulating layer) 21. When etching 30, other parts are protected so that a wet etching solution or ions or radicals for plasma etching do not enter inside. Here, the resist 21 covering the block 30 of the semiconductor substrate 1 is exposed to ultraviolet light, developed, and exposed.
When plasma etching is used, portions other than the block of the semiconductor substrate 1 are covered with an insulating layer, for example, an SOG film.

  FIG. 31 shows a state after the step of selectively wet etching the semiconductor substrate 1 with TMAH or TMAH + ammonium persulfate, removing the SiC layer 2 and the buffer layer 3 on the front side by plasma etching, and removing the peripheral resist layer 21. Indicates the status. When performing selective dry etching by SF6, the SOG film is removed after the etching.

  FIG. 32 shows a state after the step of forming the interlayer insulating layer 22 between the patterns of the blue micro LEDs 13.

FIG. 33 shows a state after the step of forming the transparent electrode wiring 48 on the surface of the blue micro LED 13. The transparent electrode wiring 48 may be formed directly using photolithography on the display device having the blue micro LED 13 shown in FIG. 32, or the electrode wiring structure 48 may be formed on another transparent substrate (not shown) in advance. Alternatively, this transparent substrate may be bonded to a display device. Normally, the electrode wiring structure 48 is used as the ground, but the present invention is not limited to this.

  In FIG. 34, a red fluorescent layer pattern, a green fluorescent layer pattern, and an insulating layer pattern that emits blue light as they are are formed on the transparent electrode wiring, and a red light emitting element 61, a green light emitting element 62, and a blue light emitting element are formed. This shows the state after the step of forming 63.

FIG. 35 shows a state after the step of removing the interlayer insulating layer above the extraction electrode 47 and connecting to a power supply (not shown).

The display device including the red light emitting element 61, the green light emitting element 62, and the light emitting element including the blue light emitting element obtained as described above is connected to the red light emitting element embedded wiring 41 of the display wiring board 12 by the green light emitting element. A voltage is applied between the element embedded wiring 42 and the blue light emitting element embedded wiring 43, the transparent electrode 48 on the surface of the light emitting element composed of the red light emitting element 61, the green light emitting element 62, and the blue light emitting element. By combining these, the display device functions as a display device that generates various luminescent colors.
(Embodiment 3)

In this embodiment, instead of forming red, green, and blue LEDs, a blue micro LED 13 is formed, a transparent electrode wiring 48 is formed thereon, and a red fluorescent layer 51 pattern and a green fluorescent layer are formed thereon. 52, and a transparent insulating layer pattern 53 are formed to form a red light emitting element 61, a green light emitting element 62, and a blue light emitting element 63, respectively. , And a large number of light-emitting elements, each of which is a set of blue light-emitting elements 63, are developed on the substrate 1 so as to function as a color display device.

  A semiconductor substrate 1 is prepared as shown in FIG. 1, and a GaN buffer layer 3 of 3 to 10 μm is formed on both surfaces of the semiconductor substrate 1 by a low pressure CVD method (not shown) as shown in FIG. As shown in FIG. 1, a p-type GaN layer 4 of 0.3 to 2 μm, a quantum well layer 5 of 10 to 100 nm, and an n-type GaN layer 6 of 0.3 to 2 μm are epitaxially grown on the surface of the semiconductor substrate 1 to obtain a blue color. A step of forming a structure in which the warpage of the semiconductor substrate 1 is reduced before forming a micro LED will be described. The reason why the epitaxial layer is formed on the surface of the semiconductor substrate 1 is to consider the use of a commercially available epitaxial device.

In FIG. 15, an electrode layer 7 is further formed on the n-type epitaxial layer 6, and a resist pattern 8 for forming a blue micro LED is formed thereon. FIG. 16 shows a step of forming the blue micro LED 13 on the surface of the semiconductor substrate 1. The blue micro LED has a structure including a p-type GaN layer 4 of 0.3 to 2 μm, a quantum well layer 5 of 10 to 100 nm, an n-type GaN layer 6 of 0.3 to 2 μm, and an electrode layer 7 of 500 to 2 μm. It has become. The adjustment of the In concentration in the quantum well layer may be performed by selective ion implantation or by selective epitaxial growth. In this manner, a large number of sets of micro LEDs, each set of three blue micro LEDs, are developed on the semiconductor substrate 1.

FIG. 17 shows a process in which the GaN buffer layer 3 on the back surface and the back surface of the semiconductor substrate 1 are ground by a grinder to reduce the remaining thickness of the semiconductor substrate 1 substrate to 50 to 300 μm. The dotted line is the part to be ground. FIG. 18 shows a state after the step of grinding the back surface of the GaN buffer layer 3 and the back surface of the semiconductor substrate 1 with a grinder to grind the semiconductor substrate 1 to a thickness of 50 to 300 μm.

FIG. 24 shows a step of cutting the semiconductor substrate 1 having the blue micro LEDs 13 into blocks 30 in order to transfer the semiconductor substrate 1 to the display wiring substrate 40.

FIG. 26 shows a step of inverting the semiconductor substrate 1 provided with the blue micro LEDs 13 to transfer the semiconductor substrate 1 to the display wiring substrate 40.

FIG. 27 shows a display wiring board 40 having a wiring for driving the blue micro LED 13. The display wiring board includes a red light emitting element embedded wiring 41, a green light emitting element embedded wiring 42, and a blue light emitting element. The device includes an embedded wiring 43, a contact electrode for a red light emitting element 44, a contact electrode for a green light emitting element 45, a contact electrode for a blue light emitting element 46, and an extraction electrode 47.

  FIG. 28 shows a transfer step of aligning the block 30 of the semiconductor substrate 1 provided with the blue micro LED 13 with the display wiring substrate 40 and joining the corresponding electrodes of both substrates. A conductive adhesive or solder (not shown) is formed on the electrode surface on the surface of the display wiring substrate 40. Here, as indicated by the dashed line arrow, one of the three sets of blue micro LEDs 13 and the contact electrode 44 for the red light emitting element, the other of the set of three blue micro LEDs 13 and the green light emitting element contact electrode 45, Another one of the set of three blue micro LEDs 13 is joined to the blue light emitting element contact electrode 46 after being aligned.

FIG. 29 shows a state after the step of joining the block 30 of the semiconductor substrate 1 and the display wiring substrate 40.

FIG. 30 shows a step of applying a block other than the bonded block 30 of the semiconductor substrate 1 and the block 30 of the semiconductor substrate 1 having the structure of the display wiring board 40 with a resist (or an organic material or an insulating layer) 21. When etching 30, other parts are protected so that a wet etching solution or ions or radicals for plasma etching do not enter inside. Here, the resist 21 covering the block 30 of the semiconductor substrate 1 is exposed to ultraviolet light, developed, and exposed.
When plasma etching is used, portions other than the block of the semiconductor substrate 1 are covered with an insulating layer, for example, an SOG film.

FIG. 31 shows a state after the step of selectively wet etching the semiconductor substrate 1 with TMAH or TMAH + ammonium persulfate, removing the buffer layer 3 on the front side by plasma etching, and removing the peripheral resist layer 21.
When performing selective dry etching by SF6, the SOG film is removed after the etching.

  FIG. 32 shows a state after the step of forming the interlayer insulating layer 22 between the patterns of the blue micro LED.

FIG. 33 shows a state after the step of forming the transparent electrode wiring 48 on the surface of the blue micro LED 13. The transparent electrode wiring 48 may be formed directly on the display device including the blue micro LED shown in FIG. 32 by using photolithography, or the electrode wiring structure 48 may be formed on another transparent substrate (not shown) in advance. Alternatively, this transparent substrate may be bonded to a display device. Normally, the electrode wiring structure 48 is used as the ground, but the present invention is not limited to this.

  In FIG. 34, a red fluorescent layer pattern, a green fluorescent layer pattern, and an insulating layer pattern that emits blue light as they are are formed on the transparent electrode wiring, and a red light emitting element 61, a green light emitting element 62, and a blue light emitting element are formed. This shows the state after the step of forming 63.

FIG. 35 shows a state after the step of removing the interlayer insulating layer above the extraction electrode 47 and connecting to a power supply (not shown).

The display device using the three color light-emitting elements including the red light-emitting element 61, the green light-emitting element 62, and the blue light-emitting element thus obtained is connected to the red light-emitting element embedded wiring 41 of the display wiring board 12 A voltage is applied between the green light emitting element embedded wiring 42 and the blue light emitting element embedded wiring 43, and the transparent electrode 48 on the surface of the light emitting element composed of the red light emitting element 61, the green light emitting element 62, and the blue light emitting element; The display device functions as a display device that generates various luminescent colors by combining the magnitudes of the voltages.
(Embodiment 4)

  In this embodiment, instead of forming red, green, and blue LEDs, a blue micro LED 13 is formed, a transparent electrode wiring 48 is formed thereon, and a red fluorescent layer 51 pattern and a green fluorescent layer are formed thereon. 52, and a transparent insulating layer pattern 53 are formed to form a red light emitting element 61, a green light emitting element 62, and a blue light emitting element 63, respectively. , And a large number of light-emitting elements, each of which is a set of blue light-emitting elements 63, are developed on the substrate 1 to function as a color display device.

  As shown in FIG. 1, a semiconductor substrate 1 is prepared, and as shown in FIG. 19, a GaN buffer layer 3 of 3 to 10 μm is formed on both surfaces of the semiconductor substrate 1 by a low-pressure CVD method (not shown). A structure in which a p-type GaN layer 4 of 3 to 2 μm, a quantum well layer 5 of 10 to 100 nm, and an n-type GaN layer 6 of 0.3 to 2 μm are epitaxially grown to reduce the warpage of the semiconductor substrate 1 before forming a micro LED. Is shown.

In FIG. 20, an electrode layer 7 is further formed on the n-type epitaxial layer 6, and a resist pattern 8 for forming a blue micro LED is formed thereon. FIG. 21 shows a step of forming the blue micro LED 13 on the surface of the semiconductor substrate 1. The blue micro LED has a structure including a p-type GaN layer 4 of 0.3 to 2 μm, a quantum well layer 5 of 10 to 100 nm, an n-type GaN layer 6 of 0.3 to 2 μm, and an electrode layer 7 of 500 to 2 μm. It has become. The adjustment of the In concentration in the quantum well layer may be performed by selective ion implantation or by selective epitaxial growth. In this manner, a large number of sets of micro LEDs, each set of three blue micro LEDs, are developed on the semiconductor substrate 1.

FIG. 22 shows that the back surface of the n-type GaN layer 6, the quantum well layer 5, the p-type GaN layer 4, the GaN buffer layer 3, and the back surface of the semiconductor substrate 1 are ground by a grinder, The step of setting the thickness to 50 to 300 μm is shown. The dotted line is the part to be ground. FIG. 23 shows that the back surface of the n-type GaN layer 6, the quantum well layer 5, the p-type GaN layer 4, the GaN buffer layer 3, and the back surface of the semiconductor substrate 1 are ground by a grinder, so that the semiconductor substrate 1 is 50 to 300 μm thick. This shows the state after the step of grinding to a thickness.

FIG. 24 shows a step of cutting the semiconductor substrate 1 having the blue micro LEDs 13 into blocks 30 in order to transfer the semiconductor substrate 1 to the display wiring substrate 40.

FIG. 26 shows a step of inverting the semiconductor substrate 1 provided with the blue micro LEDs 13 to transfer the semiconductor substrate 1 to the display wiring substrate 40.

FIG. 27 shows a display wiring board 40 having a wiring for driving the blue micro LED 13. The display wiring board includes a red light emitting element embedded wiring 41, a green light emitting element embedded wiring 42, and a blue light emitting element. The device includes an embedded wiring 43, a contact electrode for a red light emitting element 44, a contact electrode for a green light emitting element 45, a contact electrode for a blue light emitting element 46, and an extraction electrode 47.

  FIG. 28 shows a transfer step of aligning the block 30 of the semiconductor substrate 1 provided with the blue micro LED 13 with the display wiring substrate 40 and joining the corresponding electrodes of both substrates. A conductive adhesive or solder (not shown) is formed on the electrode surface on the surface of the display wiring substrate 40. Here, as indicated by the dashed line arrow, one of the three sets of blue micro LEDs 13 and the contact electrode 44 for the red light emitting element, the other of the set of three blue micro LEDs 13 and the green light emitting element contact electrode 45, Another one of the set of three blue micro LEDs 13 is joined to the blue light emitting element contact electrode 46 after being aligned.

FIG. 29 shows a state after the step of joining the block 30 of the semiconductor substrate 1 and the display wiring substrate 40.

FIG. 30 shows a step of applying a block other than the bonded block 30 of the semiconductor substrate 1 and the block 30 of the semiconductor substrate 1 having the structure of the display wiring board 40 with a resist (or an organic material or an insulating layer) 21. When etching 30, other parts are protected so that a wet etching solution or ions or radicals for plasma etching do not enter inside. Here, the resist 21 covering the block 30 of the semiconductor substrate 1 is exposed to ultraviolet light, developed, and exposed.
When plasma etching is used, portions other than the block of the semiconductor substrate 1 are covered with an insulating layer, for example, an SOG film.

  FIG. 31 shows a state after the step of selectively wet etching the semiconductor substrate 1 with TMAH or TMAH + ammonium persulfate, removing the buffer layer 3 on the front side by plasma etching, and removing the peripheral resist layer 21. When performing selective dry etching by SF6, the SOG film is removed after the etching.

  FIG. 32 shows a state after the step of forming the interlayer insulating layer 22 between the patterns of the blue micro LEDs 13.

FIG. 33 shows a state after the step of forming the transparent electrode wiring 48 on the surface of the blue micro LED 13. The transparent electrode wiring 48 may be formed directly on the display device including the blue micro LED shown in FIG. 32 by using photolithography, or the electrode wiring structure 48 may be formed on another transparent substrate (not shown) in advance. Alternatively, this transparent substrate may be bonded to a display device. Normally, the electrode wiring structure 48 is used as the ground, but the present invention is not limited to this.

  In FIG. 34, a red fluorescent layer pattern, a green fluorescent layer pattern, and an insulating layer pattern that emits blue light as they are are formed on the transparent electrode wiring, and a red light emitting element 61, a green light emitting element 62, and a blue light emitting element are formed. This shows the state after the step of forming 63.

FIG. 35 shows a state after the step of removing the interlayer insulating layer above the extraction electrode 47 and connecting to a power supply (not shown).

The display device including the red light emitting element 61, the green light emitting element 62, and the light emitting element including the blue light emitting element obtained as described above is connected to the red light emitting element embedded wiring 41 of the display wiring board 12 by the green light emitting element. A voltage is applied between the element embedded wiring 42 and the blue light emitting element embedded wiring 43, the color light emitting element 61, the green light emitting element 62, and the transparent electrode 48 on the surface of the light emitting element including the blue light emitting element. By combining these, the display device functions as a display device that generates various luminescent colors.
(Example 1)

  As shown in FIG. 1, a semiconductor substrate 1 is prepared, and as shown in FIG. 3, a 100 nm SiC layer 2 is formed on both surfaces of the semiconductor substrate 1 by a low pressure CVD method (not shown), and a 7 μm GaN layer is formed thereon. A buffer layer 3 is formed, and as shown in FIG. 4, a 0.7 μm p-type GaN layer 4, a 50 nm quantum well layer 5, and a 0.7 μm n-type GaN layer 6 are formed on the surface of the semiconductor substrate 1. The state after the step of epitaxially growing and forming a structure in which the warpage of the Si substrate 1 is reduced before the formation of the blue micro LED 13 is shown.

In FIG. 4, an electrode layer 7 is further formed on the n-type epitaxial layer 6, and a resist pattern 8 for forming a micro LED is formed thereon. FIG. 5 shows a state after the step of forming the blue micro LED 13 on the surface of the semiconductor substrate 1. The blue micro LED has a structure including a 0.7 μm p-type GaN layer 4, a 50 nm quantum well layer 5, a 0.7 μm n-type GaN layer 6 and a 1 μm electrode layer 7. The In concentration of the quantum well layer was adjusted by epitaxial growth. In this manner, a large number of sets of micro LEDs each including three blue micro LEDs 13 were developed on the Si substrate 1.

FIG. 6 shows a process in which the back surface of the GaN buffer layer 3, the SiC layer 2, and the back surface of the conductive substrate 1 are ground by a grinder to make the remaining thickness of the substrate 250 μm. The dotted line is the ground portion. FIG. 7 shows a state after the step of grinding the back surface of the GaN buffer layer 3, the SiC layer 2, and the back surface of the Si substrate 1 by a grinder, and grinding the remaining thickness of the Si substrate to a thickness of 250 μm. Show.

FIG. 24 shows a process in which the Si substrate 1 having the blue micro LEDs 13 is cut into blocks 30 in order to transfer the Si substrate 1 to the display wiring substrate 40.

FIG. 25 shows a reversed process for transferring the Si substrate 1 provided with the blue micro LED 13 to the display wiring substrate 40.

FIG. 27 shows a display wiring board 40 having a wiring for driving the blue micro LED 13. The display wiring board includes a red light emitting element embedded wiring 41, a green light emitting element embedded wiring 42, and a blue light emitting element. The device includes an embedded wiring 43, a contact electrode for a red light emitting element 44, a contact electrode for a green light emitting element 45, a contact electrode for a blue light emitting element 46, and an extraction electrode 47.

  FIG. 28 shows a transfer step in which the block 30 of the Si substrate 1 provided with the blue micro LED 13 is aligned with the display wiring substrate 40 and the corresponding electrodes of both substrates are joined. A conductive adhesive (not shown) is formed on the electrode surface on the display wiring substrate 40. Here, as indicated by the dashed line arrow, one of the three sets of blue micro LEDs 13 and the contact electrode 44 for the red light emitting element, the other of the set of three blue micro LEDs 13 and the green light emitting element contact electrode 45, Another one of the set of three blue micro LEDs 13 was joined to the blue light emitting element contact electrode 46 after being aligned.

FIG. 29 shows a state after the step of bonding the block 30 of the Si substrate 1 and the display wiring substrate 40.

FIG. 30 shows a process in which the block 30 of the bonded Si substrate 1 and the block 30 of the Si substrate 1 having the structure of the display wiring substrate 40 are coated with the resist 21, and when the block 30 of the semiconductor substrate 1 is etched, Was protected so that a wet etching solution or ions or radicals for plasma etching did not enter inside. Here, the resist 21 covering the block 30 of the semiconductor substrate 1 was exposed to ultraviolet light and developed to be exposed.

  FIG. 31 shows that the Si substrate 1 is wet-etched with an etching solution in which 2% by weight of ammonium persulfate is added to 25% by weight of tetramethylammonium hydroxide solution (TMAH), and the SiC layer 2 and the buffer layer 3 on the surface side are CF4 The state after the step of removing by the plasma etching and removing the peripheral resist layer 21 is also shown.

  FIG. 32 shows a state after the step of forming the interlayer insulating layer 22 between the patterns of the blue micro LEDs 13.

FIG. 33 shows a state after the step of forming the transparent electrode wiring 48 on the surface of the blue micro LED 13. As the transparent electrode wiring 48, photolithography was directly used for a display device including the blue micro LED 13 shown in FIG. This electrode wiring structure 48 was used as ground.

  In FIG. 34, on the transparent electrode wiring, a red fluorescent layer 51 pattern, a green fluorescent layer 52 pattern, and an insulating layer 53 pattern for emitting blue light as it is are formed, and a red light emitting element 61, a green light emitting element 62, and The state after the step of forming the blue light emitting element 63 is shown.

FIG. 35 shows a state after the step of removing the interlayer insulating layer above the extraction electrode 47 and preparing for connection to a power supply (not shown).

The red light-emitting element embedded wiring 41 of the display wiring board 12 of the display device using the light-emitting element including the red light-emitting element 61, the green light-emitting element 62, and the blue light-emitting element thus obtained, and the green light-emitting element A voltage is applied between the transparent wiring 48 on the surface of the light emitting element composed of the embedded wiring 42 for blue light emitting element, the embedded wiring 43 for blue light emitting element, the red light emitting element 61, the green light emitting element 62, and the blue light emitting element. By combining the above, they functioned as a display device for generating various luminescent colors.
(Example 2)

  As shown in FIG. 1, a Si substrate 1 is prepared, and as shown in FIG. 8, a 100 nm SiC layer 2 is formed on both surfaces of the Si substrate 1 by a low pressure CVD method (not shown), and a 7 μm GaN is formed thereon. A buffer layer 3 is formed, and a 0.7 μm p-type GaN layer 4, a 50 nm quantum well layer 5, and a 0.7 μm n-type GaN layer 6 are epitaxially grown. 4 shows a step of forming a structure with reduced warpage.

In FIG. 9, an electrode layer 7 is further formed on the n-type epitaxial layer 6, and a resist pattern 8 is formed thereon for forming a blue micro LED. FIG. 10 shows a step of forming the blue micro LED 13 on the surface of the Si substrate 1. The blue micro LED 13 has a structure including a 0.7 μm p-type GaN layer 4, a 50 nm quantum well layer 5, a 0.7 μm n-type GaN layer 6 and a 1 μm electrode layer 11. The In concentration of the quantum well layer was adjusted by epitaxial growth. In this manner, a large number of sets of micro LEDs each including three blue micro LEDs 13 were developed on the Si substrate 1.

FIG. 11 shows that the back surface of the n-type GaN layer 6, the quantum well layer 5, the p-type GaN layer 4, the GaN buffer layer 3, the SiC layer 2, and the back surface of the conductive substrate 1 are ground by a grinder, 1 shows a process in which the remaining thickness of No. 1 was set to 250 μm. The dotted line is the ground portion. FIG. 12 shows that the back surface of the n-type GaN layer 6, the quantum well layer 5, the p-type GaN layer 4, the GaN buffer layer 3, the SiC layer 2, and the back surface of the conductive substrate 1 are ground by a grinder, The state after the step of grinding the remaining thickness of No. 1 to a thickness of 250 μm is shown.

FIG. 24 shows a process in which the Si substrate 1 having the blue micro LEDs 13 is cut into blocks 30 in order to transfer the Si substrate 1 to the display wiring substrate 40.

FIG. 25 shows a reversed process for transferring the Si substrate 1 provided with the blue micro LED 13 to the display wiring substrate 40.

FIG. 27 shows a display wiring board 40 having a wiring for driving the blue micro LED 13. The display wiring board includes a red light emitting element embedded wiring 41, a green light emitting element embedded wiring 42, and a blue light emitting element. The device includes an embedded wiring 43, a contact electrode for a red light emitting element 44, a contact electrode for a green light emitting element 45, a contact electrode for a blue light emitting element 46, and an extraction electrode 47.

  FIG. 28 shows a transfer step in which the block 30 of the semiconductor substrate 1 provided with the blue micro LED 13 is aligned with the display wiring substrate 40 and the corresponding electrodes of both substrates are joined. A conductive adhesive (not shown) is formed on the electrode surface on the display wiring substrate 40. Here, as indicated by the dashed line arrow, one of the three sets of blue micro LEDs 13 and the contact electrode 44 for the red light emitting element, the other of the set of three blue micro LEDs 13 and the green light emitting element contact electrode 45, Another one of the set of three blue micro LEDs 13 was joined to the blue light emitting element contact electrode 46 after being aligned.

FIG. 29 shows a state after the step of bonding the block 30 of the semiconductor substrate 1 and the display wiring substrate 40.

FIG. 30 shows a process in which the block 30 of the bonded Si substrate 1 and the block 30 of the Si substrate 1 having the structure of the display wiring substrate 40 are coated with the resist 21, and when the block 30 of the semiconductor substrate 1 is etched, Was protected so that a wet etching solution or ions or radicals for plasma etching did not enter inside. Here, the resist 21 covering the block 30 of the semiconductor substrate 1 was exposed to ultraviolet light and developed to be exposed.

  FIG. 31 shows that the Si substrate 1 is wet-etched with an etching solution in which 2% by weight of ammonium persulfate is added to 25% by weight of tetramethylammonium hydroxide solution (TMAH), and the SiC layer 2 and the buffer layer 3 on the surface side are CF4 The state after the step of removing by the plasma etching and removing the peripheral resist layer 21 is also shown.

  FIG. 32 shows a state after the step of forming the interlayer insulating layer 22 between the patterns of the blue micro LEDs 13.

FIG. 33 shows a state after the step of forming the transparent electrode wiring 48 on the surface of the blue micro LED 13. The transparent electrode wiring 48 was formed by directly using photolithography on a display device including the blue micro LED shown in FIG. This electrode wiring structure 48 was used as ground.

  In FIG. 34, on the transparent electrode wiring, a red fluorescent layer 51 pattern, a green fluorescent layer 52 pattern, and an insulating layer 53 pattern for emitting blue light as it is are formed, and a red light emitting element 61, a green light emitting element 62, and The state after the step of forming the blue light emitting element 63 is shown.

FIG. 35 shows a step in which the interlayer insulating layer on the extraction electrode 47 is removed and preparations for connection to a power supply (not shown) are made.

The red light emitting element embedded wiring 41 of the display wiring board 12 of the display device including the light emitting element including the red light emitting element 61, the green light emitting element 62, and the blue light emitting element thus obtained, and the green light emitting element A voltage is applied between the transparent wiring 48 on the surface of the light emitting element composed of the embedded wiring 42 for blue light emitting element, the embedded wiring 43 for blue light emitting element, the red light emitting element 61, the green light emitting element 62, and the blue light emitting element. Were combined to function as a display device for generating various luminescent colors.
(Example 3)

  As shown in FIG. 1, a Si substrate 1 is prepared, and as shown in FIG. 13, a 7 μm GaN buffer layer 3 is formed on both surfaces of the semiconductor substrate 1 by a low-pressure CVD method (not shown), and as shown in FIG. As described above, a 0.7 μm p-type GaN layer 4, a 50 nm quantum well layer 5, and a 0.7 μm n-type GaN layer 6 are epitaxially grown on the surface of the Si substrate 1, and the semiconductor substrate is formed before the blue micro LED 13 is formed. 1 shows a step of forming a structure in which the warpage is reduced.

In FIG. 15, an electrode layer 7 is further formed on the n-type epitaxial layer 6, and a resist pattern 8 for forming a micro LED is formed thereon. FIG. 16 shows a step of forming the blue micro LED 13 on the surface of the Si substrate 1. The blue micro LED has a structure including a 0.7 μm p-type GaN layer 4, a 50 nm quantum well layer 5, a 0.7 μm n-type GaN layer 6, and a 1 μm electrode layer 11. The In concentration of the quantum well layer was adjusted by epitaxial growth. In this way, a large number of sets of micro LEDs each including three blue micro LEDs were developed on the semiconductor substrate 1.

FIG. 17 shows a step of grinding the back surface of the GaN buffer layer 3 and the back surface of the conductive substrate 1 with a grinder to make the remaining thickness of the Si substrate 1 250 μm. The dotted line is the ground portion. FIG. 18 shows a state after the step of grinding the back surface of the GaN buffer layer 3 and the back surface of the Si substrate 1 by a grinder and grinding the remaining thickness of the Si substrate 1 to a thickness of 250 μm.

FIG. 24 shows a process in which the semiconductor substrate 1 having the blue micro LEDs 13 is cut into blocks 30 in order to transfer the semiconductor substrate 1 to the display wiring substrate 40.

FIG. 26 shows a reversed process for transferring the semiconductor substrate 1 provided with the blue micro LEDs 13 to the display wiring substrate 40.

FIG. 27 shows a display wiring board 40 having a wiring for driving the blue micro LED 13. The display wiring board includes a red light emitting element embedded wiring 41, a green light emitting element embedded wiring 42, and a blue light emitting element. The device includes an embedded wiring 43, a contact electrode for a red light emitting element 44, a contact electrode for a green light emitting element 45, a contact electrode for a blue light emitting element 46, and an extraction electrode 47.

  FIG. 28 shows a transfer step in which the block 30 of the semiconductor substrate 1 provided with the blue micro LED 13 is aligned with the display wiring substrate 40 and the corresponding electrodes of both substrates are joined. Solder (not shown) is formed on the electrode surface on the surface of the display wiring substrate 40. Here, as indicated by the dashed line arrow, one of the three sets of blue micro LEDs 13 and the contact electrode 44 for the red light emitting element, the other of the set of three blue micro LEDs 13 and the green light emitting element contact electrode 45, Another one of the set of three blue micro LEDs 13 was joined to the blue light emitting element contact electrode 46 after being aligned.

FIG. 29 shows a state after the step of bonding the block 30 of the semiconductor substrate 1 and the display wiring substrate 40.

FIG. 30 shows a process in which the block 30 of the bonded Si substrate 1 and the block 30 of the Si substrate 1 having the structure of the display wiring substrate 40 are coated with the resist 21, and when the block 30 of the semiconductor substrate 1 is etched, Was protected so that a wet etching solution or ions or radicals for plasma etching did not enter inside. Here, the resist 21 covering the block 30 of the semiconductor substrate 1 was exposed to ultraviolet light and developed to be exposed.

  FIG. 31 shows that the Si substrate 1 is wet-etched with an etching solution obtained by adding 2% by weight of ammonium persulfate to 25% by weight of tetramethylammonium hydroxide solution (TMAH), and the buffer layer 3 on the front side is subjected to plasma etching of CF4. The state after the step of removing the peripheral resist layer 21 and removing the peripheral resist layer 21 is shown.

  FIG. 32 shows a state after the step of forming the interlayer insulating layer 22 between the patterns of the blue micro LEDs 13.

FIG. 33 shows a state after the step of forming the transparent electrode wiring 48 on the surface of the blue micro LED 13. The transparent electrode wiring 48 was formed by directly using photolithography on a display device including the blue micro LED shown in FIG. This electrode wiring structure 48 was used as ground.

  In FIG. 34, a red fluorescent layer pattern 51, a green fluorescent layer pattern 52, and an insulating layer pattern 53 that emits blue light as it is formed on the transparent electrode wiring, and a red light emitting element 61, a green light emitting element 62, and The state after the step of forming the blue light emitting element 63 is shown.

FIG. 35 shows a step in which the interlayer insulating layer on the extraction electrode 47 is removed and preparations for connection to a power supply (not shown) are made.

The red light emitting element 61, the green light emitting element 62, and the red light emitting element embedded wiring 41 of the display wiring substrate 12 of the display device using the three color light emitting elements including the blue light emitting element, A voltage is applied between the green light emitting element embedded wiring 42 and the blue light emitting element embedded wiring 43, the red light emitting element 61, the green light emitting element 62, and the transparent electrode 48 on the surface of the blue light emitting element to reduce the magnitude of the voltage. In combination, they functioned as a display device for generating various luminescent colors.
(Example 4)

  As shown in FIG. 1, a Si substrate 1 is prepared. As shown in FIG. 19, a 7 μm GaN buffer layer 3 is formed on both surfaces of the semiconductor substrate 1 by a low-pressure CVD method (not shown). A step of epitaxially growing a p-type GaN layer 4, a quantum well layer 5 of 50 nm, and an n-type GaN layer 6 of 0.7 μm to form a structure in which the warpage of the Si substrate 1 is reduced before forming a micro LED is shown.

In FIG. 20, an electrode layer 7 is further formed on the n-type epitaxial layer 6, and a resist pattern 8 for forming a micro LED is formed thereon. FIG. 21 shows a step of forming the blue micro LED 13 on the surface of the Si substrate 1. The blue micro LED has a structure including a 0.7 μm p-type GaN layer 4, a 50 nm quantum well layer 5, a 0.7 μm n-type GaN layer 6 and a 1 μm electrode layer 7. The In concentration of the quantum well layer was adjusted by epitaxial growth. In this way, a large number of sets of micro LEDs each including three blue micro LEDs were developed on the semiconductor substrate 1.

FIG. 22 shows that the back surface of the n-type GaN layer 6, the quantum well layer 5, the p-type GaN layer 4, the GaN buffer layer 3, and the back surface of the conductive substrate 1 are ground by a grinder to reduce the remaining thickness of the substrate to 250 μm. Are shown. The dotted line is the ground portion. FIG. 23 shows that the back surface of the n-type GaN layer 6, the quantum well layer 5, the p-type GaN layer 4, the GaN buffer layer 3, and the back surface of the Si substrate 1 are ground by a grinder, and the remaining thickness of the Si substrate 1 is reduced. This shows the state after the step of grinding to a thickness of 250 μm.

FIG. 24 shows a process in which the semiconductor substrate 1 having the blue micro LEDs 13 is cut into blocks 30 in order to transfer the semiconductor substrate 1 to the display wiring substrate 40.

FIG. 26 shows a reversed process for transferring the semiconductor substrate 1 provided with the blue micro LEDs 13 to the display wiring substrate 40.

FIG. 27 shows a display wiring board 40 having a wiring for driving the blue micro LED 13. The display wiring board includes a red light emitting element embedded wiring 41, a green light emitting element embedded wiring 42, and a blue light emitting element. The device includes an embedded wiring 43, a contact electrode for a red light emitting element 44, a contact electrode for a green light emitting element 45, a contact electrode for a blue light emitting element 46, and an extraction electrode 47.

  FIG. 28 shows a transfer step in which the block 30 of the semiconductor substrate 1 provided with the blue micro LED 13 is aligned with the display wiring substrate 40 and the corresponding electrodes of both substrates are joined. Solder (not shown) is formed on the electrode surface on the surface of the display wiring substrate 40. Here, as indicated by the dashed line arrow, one of the three sets of blue micro LEDs 13 and the contact electrode 44 for the red light emitting element, the other of the set of three blue micro LEDs 13 and the green light emitting element contact electrode 45, Another one of the set of three blue micro LEDs 13 was joined to the blue light emitting element contact electrode 46 after being aligned.

FIG. 29 shows a state after the step of bonding the block 30 of the Si substrate 1 and the display wiring substrate 40.

FIG. 30 shows a process in which the block 30 of the bonded Si substrate 1 and the block 30 of the Si substrate 1 having the structure of the display wiring substrate 40 are coated with the resist 21, and when the block 30 of the semiconductor substrate 1 is etched, Was protected so that a wet etching solution or ions or radicals for plasma etching did not enter inside. Here, the resist 21 covering the block 30 of the semiconductor substrate 1 was exposed to ultraviolet light and developed to be exposed.

  FIG. 31 shows that the Si substrate 1 is wet-etched with an etching solution obtained by adding 2% by weight of ammonium persulfate to 25% by weight of tetramethylammonium hydroxide solution (TMAH), and the buffer layer 3 on the front side is subjected to plasma etching of CF4. The state after the step of removing the peripheral resist layer 21 and removing the peripheral resist layer 21 is shown.

  FIG. 32 shows a state after the step of forming the interlayer insulating layer 22 between the patterns of the blue micro LEDs 13.

FIG. 33 shows a state after the step of forming the transparent electrode wiring 48 on the surface of the blue micro LED 13. The transparent electrode wiring 48 was formed by directly using photolithography on a display device including the blue micro LED shown in FIG. This electrode wiring structure 48 was used as ground.

  In FIG. 34, a red fluorescent layer pattern 51, a green fluorescent layer pattern 52, and an insulating layer pattern 53 that emits blue light as it is formed on the transparent electrode wiring, and a red light emitting element 61, a green light emitting element 62, and The state after the step of forming the blue light emitting element 63 is shown.

FIG. 35 shows a step in which the interlayer insulating layer on the extraction electrode 47 is removed and preparations for connection to a power supply (not shown) are made.

  The red light emitting element embedded wiring 41 of the display wiring board 12 of the display device including the light emitting element including the red light emitting element 61, the green light emitting element 62, and the blue light emitting element thus obtained, and the green light emitting element A voltage is applied between the embedded wiring 42 for embedded light and the embedded wiring 43 for blue light emitting element, the red light emitting element 61, the green light emitting element 62, and the transparent electrode 48 on the surface of the blue light emitting element, and the magnitude of the voltage is combined. It was made to function as a display device for generating various emission colors.

1 semiconductor substrate (Si wafer) or insulator substrate (sapphire wafer)
2 SiC layer (or crystal layer having a lattice constant close to that of GaN)
3 GaN buffer layer (or semiconductor buffer layer)
4 p-type GaN epitaxial layer 5 quantum well layer 6 n-type GaN epitaxial layer 7 electrode layer 8 resist pattern
13. Blue micro LED
21 Resist layer or insulating layer 22 Insulating layer 30 Semiconductor substrate rectangular block (Si rectangular block) or sapphire rectangular block)
Reference Signs List 40 Display wiring board 41 Red light emitting element embedded wiring 42 Green light emitting element embedded wiring 43 Blue light emitting element embedded wiring 44 Red light emitting element contact electrode 45 Green light emitting element contact electrode 46 Blue light emitting element contact electrode 47 Leader electrode 48 Transparent electrode wiring 51 Red fluorescent layer pattern 52 Green fluorescent layer pattern 53 Transparent insulating layer pattern 61 Red light emitting element 62 Green light emitting element 63 Blue light emitting element

Claims (8)

Forming a SiC layer and a GaN buffer layer on both surfaces of the semiconductor substrate in this order to reduce the warpage of the semiconductor substrate;
Forming a GaN epitaxial layer on the surface of the semiconductor substrate;
Forming a blue micro LED on the SiC layer and the GaN buffer layer on the surface of the semiconductor substrate;
Grinding the GaN buffer layer on the back surface of the semiconductor substrate, the SiC layer and the semiconductor substrate,
A step of transferring the micro LED to a display wiring substrate for each semiconductor substrate or each block,
Removing the remaining portion of the semiconductor substrate and the SiC layer and the GaN buffer layer on the surface of the semiconductor substrate in a state transferred to the display wiring substrate;
Forming an interlayer insulating layer between the blue micro LED patterns,
Forming a transparent conductive layer pattern on the exposed back surface of the blue micro LED,
Forming a red fluorescent layer pattern, a green fluorescent layer pattern, and a transparent insulating layer pattern on the transparent conductive layer pattern. Forming a SiC layer, a GaN buffer layer and a GaN epitaxial layer on both surfaces of the semiconductor substrate in this order, thereby reducing the warpage of the semiconductor substrate;
Forming a blue micro LED on the SiC layer and the GaN buffer layer on the surface of the semiconductor substrate;
Grinding the GaN epitaxial layer on the back surface of the semiconductor substrate, the GaN buffer layer, the SiC layer, and the semiconductor substrate;
A step of transferring the micro LED to a display wiring substrate for each semiconductor substrate or each block,
Removing the remaining portion of the semiconductor substrate and the SiC layer and the GaN buffer layer on the surface of the semiconductor substrate in a state of being transferred to the display wiring substrate;
Forming an interlayer insulating layer between the blue micro LED patterns,
Forming a transparent conductive layer pattern on the exposed back surface of the blue micro LED,
Forming a red fluorescent layer pattern, a green fluorescent layer pattern, and a transparent insulating layer pattern on the transparent conductive layer pattern. Forming a GaN layer buffer on both surfaces of the semiconductor substrate to reduce the warpage of the semiconductor substrate;
Forming a GaN epitaxial layer on the surface of the semiconductor substrate,
Forming a blue micro LED on the GaN buffer layer on the surface of the semiconductor substrate;
Grinding the GaN buffer layer and the semiconductor substrate on the back surface of the semiconductor substrate,
Transferring the blue micro LED to a display wiring board for each semiconductor substrate or block;
Removing the remaining portion of the semiconductor substrate and the GaN layer on the surface of the semiconductor substrate in a state of being transferred to the display wiring substrate;
Forming an interlayer insulating layer between the blue micro LED patterns,
Forming a red fluorescent layer pattern, a green fluorescent layer pattern, and a transparent insulating layer pattern on the transparent conductive layer pattern. Forming a GaN layer buffer and a GaN epitaxial layer on both surfaces of the semiconductor substrate in this order to reduce the warpage of the semiconductor substrate;
Forming a blue micro LED on the GaN buffer layer on the surface of the semiconductor substrate;
Grinding the GaN epitaxial layer on the back surface of the semiconductor substrate, the GaN buffer layer, and the semiconductor substrate;
Transferring the blue micro LED to a display wiring board for each semiconductor substrate or block;
Removing the remaining portion of the semiconductor substrate and the GaN buffer layer on the surface of the semiconductor substrate in a state of being transferred to the display wiring substrate;
Forming an interlayer insulating layer between the blue micro LED patterns,
Forming a transparent conductive layer pattern on the exposed back surface of the blue micro LED,
Forming a red fluorescent layer pattern, a green fluorescent layer pattern, and a transparent insulating layer pattern on the transparent conductive layer pattern.   The method for manufacturing a light emitting device according to claim 1, wherein the semiconductor substrate is a Si substrate.   The method for manufacturing a light-emitting device according to claim 1, wherein the semiconductor substrate is a sapphire substrate.   The method for manufacturing a light emitting device according to claim 1, wherein the display wiring substrate includes a wiring structure that enables independent control of red, green, and blue light emission.   A light-emitting device manufactured by the method for manufacturing a light-emitting device according to claim 1.

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