JP2022079897A - Light emitting device, projector, and method for manufacturing light emitting device - Google Patents

Abstract

To provide a light emitting device with high reliability.SOLUTION: A light emitting device 100 comprises: a substrate 10; a columnar part group 25 that is provided on the substrate 10 and composed of a plurality of columnar parts; a structure 21 that is provided on the substrate 10 and surrounds the columnar part group 25; a first insulating part 18 that is provided between the columnar part group and the structure; and a second insulating part 23 that surrounds the outside of the structure. The columnar parts each have a first semiconductor layer 15, a first light emitting layer 16, and a second semiconductor layer 17 different in conductivity type from the first semiconductor layer. The structure has a third semiconductor layer 15a having the same conductivity type as that of the first semiconductor layer, a second light emitting layer 16a, and a fourth semiconductor layer 17a different in conductivity type from the third semiconductor layer.SELECTED DRAWING: Figure 2

Description

The present invention relates to a light emitting device, a projector provided with the light emitting device, and a method for manufacturing the light emitting device.

Semiconductor lasers are expected as next-generation light sources with high brightness. In particular, semiconductor lasers having nanostructures called nanocolumns, nanowires, nanorods, nanopillars, etc. are expected to be able to realize a light emitting device that can obtain high-power light emission at a narrow radiation angle due to the effect of photonic crystals.

For example, Patent Document 1 discloses a solid-state light emitting device having a plurality of nanocolumns. According to the document (FIG. 2), an n-type GaN nanocolumn layer and a light emitting layer are formed on a silicon substrate by an RF-MBE (radio frequency molecular beam epitaxy) device, and a p-type GaN contact layer is epitaxially grown while expanding the nanocolumn diameter. By letting them grow, nanocolumns that stand at a constant pitch are formed. Then, a translucent p-side electrode is formed on the nanocolumn. It is presumed that a nanoscale space is provided between the forested nanocolumns.

Japanese Unexamined Patent Publication No. 2010-135859

However, the technique of Patent Document 1 has a problem that the reliability of the light emitting device is poor because there is a space between the standing nanocolumns. For example, when wet etching is used when forming the p-side electrode, the chemical solution infiltrates the space between the nanocolumns from the side surface, and the electrode in the place where the embedding is insufficient is etched, resulting in poor increase in contact resistance. In addition, there is a risk that leakage defects may occur due to conductive foreign matter being caught between the nanocolumns. On the other hand, although it is possible to form the p-side electrode by dry etching, there is a risk that the semiconductor layer of the nanocolumn will be damaged by plasma charging.

The light emitting device according to the present application includes a substrate, a columnar portion group provided on the substrate and composed of a plurality of columnar portions, a structure provided on the substrate and surrounding the columnar portion group, and the columnar portion group and the structure. A first insulating portion provided between the body and a second insulating portion surrounding the outside of the structure is provided, and the columnar portion may emit light from the first conductive type first semiconductor layer. It has a possible first light emitting layer and a second conductive type second semiconductor layer different from the first conductive type, and the structure emits light with the first conductive type third semiconductor layer. It has a second light emitting layer capable of being capable, and a fourth semiconductor layer of the second conductive type.

The method for manufacturing a light emitting device according to the present application includes a step of crystallizing a columnar portion group composed of a plurality of columnar portions and a structure surrounding the columnar portion group on a substrate, and the columnar portion group and the structure. It includes a step of forming an insulating film to cover, a step of forming a first insulating portion between the columnar portion group and the structure, and a step of forming a second insulating portion surrounding the outside of the structure. In the process of growing the crystal, each of the plurality of columnar portions has a first conductive type first semiconductor layer, a first light emitting layer capable of emitting light, and a first conductive type different from the first conductive type. The two conductive type second semiconductor layer is crystal-grown, and the structure has the first conductive type third semiconductor layer, a second light emitting layer capable of emitting light, and the second conductive type. In the step of crystal-growing the fourth semiconductor layer and forming the first insulating portion, the insulating film located in the region between the columnar portion group and the structure in a plan view is etched to obtain the said insulating film. In the step of forming the first insulating portion and forming the second insulating portion, the second insulating portion is formed by etching the insulating film located in the outer region of the structure in the plan view. ..

Further, the projector according to the present application includes the above-mentioned light emitting device.

The plan view of the light emitting device which concerns on Embodiment 1. FIG. Sectional drawing of a light emitting device. The flowchart which shows the manufacturing method of a light emitting device. The process diagram which shows the product aspect in a manufacturing process. The process diagram which shows the product aspect in a manufacturing process. The process diagram which shows the product aspect in a manufacturing process. The process diagram which shows the product aspect in a manufacturing process. The process diagram which shows the product aspect in a manufacturing process. The process diagram which shows the product aspect in a manufacturing process. The process diagram which shows the product aspect in a manufacturing process. The process diagram which shows the product aspect in a manufacturing process. The schematic block diagram of the projector which concerns on Embodiment 2.

Embodiment 1
*** Outline configuration of light emitting device ***
FIG. 1 is a plan view of a light emitting device according to the present embodiment. FIG. 2 is a cross-sectional view of the light emitting device in the bb cross section of FIG.
First, the schematic configuration of the light emitting device 100 of the present embodiment will be described with reference to FIGS. 1 and 2. The light emitting device 100 is a semiconductor laser light source provided with a plurality of nanocolumns which are fine columnar crystal structures that combine electrons and holes in a semiconductor to emit light. When actually used as a light source, it is often used as a surface light source of an aggregate in which a plurality of light emitting devices 100 are regularly arranged.

In each figure including FIGS. 1 and 2, the XYZ axes are attached as coordinate axes orthogonal to each other, the direction pointed by each arrow is the plus direction, and the direction opposite to the plus direction is the minus direction. In FIG. 1, the direction of the n connection terminal portion 29 is the X plus direction with the light emitting region 5 as the center. The Z plus direction is also referred to as an upper direction, and the Z minus direction is also referred to as a lower direction. Viewing from the Z plus direction is also called a plan view.

As shown in FIG. 2, the light emitting device 100 has a configuration in which a columnar portion group 25 composed of a plurality of columnar portions 20 is provided on the substrate 10.
The substrate 10 is a substrate, and a sapphire substrate is used as a suitable example. The sapphire substrate is not limited to the sapphire substrate, and a GaN substrate, a Si substrate, a glass substrate, or the like may be used. A buffer layer 11 is formed on the surface of the substrate 10. The buffer layer 11 is a Si-doped n-type GaN layer as a suitable example. Since the buffer layer 11 is a part of the substrate 10, the buffer layer 11 may be regarded as the substrate 10 including the buffer layer 11. That is, the substrate including the buffer layer 11 may be regarded as a substrate which is a substrate 10.

Further, a reflective layer may be provided between the substrate 10 and the buffer layer 11 or on the bottom surface of the substrate 10. The reflective layer is a DBR (Distributed Bragg Reflector) layer. Since the reflective layer can reflect the light emitted from the light emitting layer 16 toward the substrate 10, the efficiency of light utilization can be improved. Further, a strain relaxation layer 11b may be provided between the substrate 10 and the buffer layer 11. The strain relaxation layer is made of, for example, AlN or GaN. When a GaN substrate is used as the substrate 10, the strain relaxation layer 11b may not be provided.

The columnar portion 20 is a nanocolumn formed on the buffer layer 11, and is composed of a first semiconductor layer 15, a light emitting layer 16 as a first light emitting layer, and a second semiconductor layer 17. Specifically, the columnar portion 20 is a columnar structure in which the first semiconductor layer 15, the light emitting layer 16, and the second semiconductor layer 17 are laminated in this order on the buffer layer 11. In a preferred example, the height of the columnar portion 20 is about 1000 nm. The dimensions are an example and can be changed as appropriate according to the design specifications such as the required brightness. The columnar portion 20 is also called a nanowire, a nanorod, or a nanopillar. The first semiconductor layer 15 projects from the buffer layer 11 along the stacking direction. That is, the first semiconductor layer 15 projects from the substrate 10 along the stacking direction. The stacking direction referred to here is the direction in which the first semiconductor layer 15 and the light emitting layer 16 are laminated. In this embodiment, it coincides with the normal direction of the substrate which is the substrate 10.

The first semiconductor layer 15 is an n-type semiconductor layer. In a preferred example, the first semiconductor layer 15 is an n-type GaN layer doped with Si. That is, the first conductive type of the first semiconductor layer 15 is n type.
In a preferred example, the light emitting layer 16 has a multiple quantum well structure in which a quantum well structure composed of an i-type GaN layer not doped with impurities and an i-type InGaN layer are overlapped. The light emitting layer 16 can emit light by injecting a current or being irradiated with excitation light. The light emitting layer 16 emits light when a current is injected from the p-side electrode 19 described later.
The second semiconductor layer 17 is a p-type semiconductor layer having a different conductive type from the first semiconductor layer 15. In a preferred example, the second semiconductor layer 17 is a p-type GaN layer doped with Mg. That is, the second conductive type of the second semiconductor layer 17 is a p type, which is different from the first conductive type. The first semiconductor layer 15 and the second semiconductor layer 17 also have a function as a clad layer for confining light in the light emitting layer 16. Further, the upper portion (end surface) of the columnar portion 20 made of the second semiconductor layer 17 has an obtuse-angled weight shape at the top. The shape of the top may have a flat portion depending on the growth conditions.

Further, the columnar portion 20 is not limited to the configuration in which the first semiconductor layer 15, the light emitting layer 16, and the second semiconductor layer 17 are laminated in this order from the substrate 10 side, and may be in the opposite stacking order. For example, the second semiconductor layer 17, the light emitting layer 16, and the first semiconductor layer 15 may be laminated in this order on the substrate 10. In this case, the current is injected from the substrate 10 side. Further, the first conductive type may be p type, and in this case, the second conductive type may be n type.

As shown in FIG. 1, the portion where light is emitted from the columnar portion group 25 is defined as the light emitting region 5. The light emitting region 5 has a substantially circular shape in a plane, and a plurality of columnar portions 20 are regularly arranged in the circular shape. One columnar portion 20 has a substantially regular hexagon in a plane. The planar shape is not limited to a hexagon, but may be another polygon or a circle.
The plurality of columnar portions 20 are arranged in a hexagonal pattern at a constant pitch. The arrangement mode is not limited to the hexagonal pattern, and may be regular. For example, it may be in a grid shape, a triangular grid shape, a square grid shape, or the like.
Further, there is a gap between the adjacent columnar portions 20, and the gap is filled by the first insulating portion 18.

In a plan view, the columnar portion group 25 is surrounded by a ring-shaped structure 21. The structure 21 has an annular shape, and concentrically surrounds the columnar portion group 25 arranged in the light emitting region 5 having a substantially circular shape. Then, as shown in FIG. 2, a first insulating portion 18 is provided between the columnar portion group 25 and the structure 21. In a preferred example, the first insulating portion 18 is made of silicon oxide. Any insulating material may be used, and for example, silicon nitride or polyimide may be used. The distance between the columnar portion group 25 and the structure 21 is preferably wider than the distance (gap) between the columnar portions 20 adjacent to each other.

In cross-sectional view, the structure 21 has a configuration in which the third semiconductor layer 15a, the light emitting layer 16a as the second light emitting layer, and the fourth semiconductor layer 17a are laminated in this order. The third semiconductor layer 15a is a semiconductor layer having the same conductive type as the first semiconductor layer 15, and in a preferred example, it is formed in the same process as the first semiconductor layer 15. Since the structure 21 is a part that does not contribute to light emission, the part names are different even if the parts are formed in the same step.
Similarly, the light emitting layer 16a is a semiconductor layer having the same composition as the light emitting layer 16, and the fourth semiconductor layer 17a is a semiconductor layer having the same composition as the second semiconductor layer 17. The light emitting layer 16a can emit light by injecting a current or irradiating with excitation light. In the present embodiment, since no current is injected into the light emitting layer 16a, light emission due to the current being injected does not occur in the light emitting layer 16a. Therefore, the third semiconductor layer 15a has a different conductive type from the fourth semiconductor layer 17a. The height of the structure 21 is higher than or equal to that of the columnar portion 20. Further, the height of the first insulating portion 18 is equal to the height of the structure 21. However, the height is not limited to this, and the height of the first insulating portion may be equal to or higher than the height of the columnar portion 20. Alternatively, the height of the first insulating portion may be between the height of the structure 21 and the height of the columnar portion 20. The height of the first insulating portion 18 referred to here is the maximum height of the first insulating portion 18.

In cross-sectional view, the outside of the structure 21 is surrounded by the second insulating portion 23. The second insulating portion 23 is a sidewall, which is provided on the outer wall of the annular structure 21, and is formed so as to become thicker from the upper side to the lower side of the wall. In a preferred example, the second insulating portion 23 is made of the same material as the first insulating portion 18.

A p-side electrode 19 is provided so as to cover the tops of the plurality of columnar portions 20. The p-side electrode 19 is a translucent electrode composed of a plurality of metal thin film layers in a preferred example. The p-side electrode 19 is an electrode that covers the columnar portion group 25 and injects a current into the second semiconductor layer 17 of the columnar portion 20. In other words, the p-side electrode 19 is not connected to the structure 21, and the p-side electrode 19 and the structure 21 are electrically separated from each other.
An insulating layer 22 is provided around the second insulating portion 23. The insulating layer 22 is an insulating protective layer that opens the light emitting region 5 at the top of the columnar portion group 25 and covers the upper portion of the structure 21 and the periphery of the second insulating portion 23. In a preferred example, the insulating layer 22 is made of silicon oxide. Any insulating material may be used, and for example, silicon nitride or polyimide may be used.

The electrode layer 24 is provided so as to cover a part of the p-side electrode 19 and the insulating layer 22. The electrode layer 24 is a transparent electrode layer, and ITO (Indium Tin Oxide) is used as a suitable example. The electrode layer 24 is electrically connected to the p-side electrode 19. Further, the laminated structure up to the electrode layer 24 including the columnar portion group 25 and the structure 21 is referred to as a laminated body 30.
The p-side wiring 26 is provided on the upper layer of the electrode layer 24. The p-side wiring 26 is a metal wiring pattern that opens substantially the same region as the inner circumference of the structure 21 including the light emitting region 5 and covers the laminated body 30. The p-side wiring 26 is provided with a p-connection terminal portion 28 to which drive power is supplied. The p-connection terminal portion 28 may be provided at a position overlapping the adjacent first insulating portion 18 or the second insulating portion 23. Further, it can be provided on the p-side electrode having no structure on the right (+ X direction) side of the insulating portion 23.

The n-side wiring 27 is provided in the + X direction of the laminated body 30. The n-side wiring 27 has the same metal wiring pattern as the p-side wiring 26, and is formed in a portion where the buffer layer 11 of the substrate 10 is slightly dug down. The n-side wiring 27 is a pattern along the right side of the substrate 10. The n-side wiring 27 is provided with an n-connection terminal portion 29 to which drive power is supplied.
The p-connection terminal portion 28 and the n-connection terminal portion 29 are power input terminals, and for example, a bonding wire is connected and a drive signal for driving light emission is input.

*** Manufacturing method and configuration of light emitting device ***
FIG. 3 is a flowchart showing a method of manufacturing a light emitting device. 4 to 11 are process diagrams showing product aspects in the manufacturing process. Here, a method and a configuration of a light emitting device will be described with reference to FIGS. 3 and 4 to 11 as appropriate.
The light emitting device 100 is basically a CVD (Chemical Vapor Deposition) method, an ALD (Atomic layer deposition) method, a photolithography method (patterning), a sputtering method, a vapor deposition method (vacuum vapor deposition method), an etching method, and a CMP (Chemical). It can be manufactured by a method used in a known semiconductor process such as a mechanical planarization method or a combination thereof. Hereinafter, a suitable manufacturing method will be mainly described, but other manufacturing methods may be used as long as an equivalent structure can be formed and the functions and characteristics of the structure can be satisfied.

In step S1, the substrate 10 is prepared prior to the formation of the nanocolumn. Specifically, as shown in FIG. 4, the buffer layer 11 is epitaxially grown on the substrate 10. As a method for epitaxial growth, for example, a MOCVD (Metal Organic Chemical Vapor Deposition) method, an MBE (Molecular Beam Epitaxy) method, or the like is used.
Next, a selection mask 12 which is a hard mask for partitioning the formation region of the columnar portion 20 is formed on the buffer layer 11. The selection mask 12 uses Ti in a preferred example. As shown in FIG. 4, the selection mask 12 has an opening portion that corresponds to a plurality of columnar portions 20 and a portion that becomes a structure 21. The selection mask 12 is formed, for example, by forming a film by a sputtering method and then performing patterning.

In step S2, a plurality of columnar portions 20 and a structure 21 are formed. Specifically, the first semiconductor layer 15, the light emitting layer 16, and the second semiconductor layer 17 are epitaxially grown on the buffer layer 11 in the opening corresponding to the columnar portion 20 of the selection mask 12 in this order. In parallel, a third semiconductor layer 15a, a light emitting layer 16a, and a fourth semiconductor layer 17a are formed in the opening corresponding to the structure 21. In a preferred example, the epitaxial growth method is crystal growth using the MBE method. When MBO is used, the height of the crystal is equal or higher in a place where the area of the opening is wide, although it depends on the growth conditions, so that the height of the structure 21 is equal or higher than that of the columnar portion 20.
As a result, as shown in FIG. 4, a columnar portion group 25 composed of a plurality of columnar portions 20 and a structure 21 which is higher or equivalent to the columnar portion group 25 and surrounds the columnar portion group 25 are formed. .. The thickness of the columnar portion 20 and the shape of the top can be changed by adjusting the growth conditions.

In step S3, the first insulating portion 18 that fills the space between the columnar portions 20 and the space between the columnar portion group 25 and the structure 21 is formed. First, the SOG (Spin on Glass) method is used to form a glass body layer 48 that covers the columnar portion group 25 and the structure 21. Specifically, as shown in FIG. 5, an SOG liquid containing silicon dioxide is applied to the entire surface of the substrate 10 by a spin coating method, and then heat-cured to form a glass body layer 48. The SOG liquid corresponds to a liquid insulator. Further, before applying SOG, silicon dioxide may be laminated on the side wall of the columnar portion group 25 and the structure 21 by several nm by the ALD method. Next, the glass body layer 48 is subjected to wet etching to expose the second semiconductor layer 17 on the head of the columnar portion 20 that stands in a forest. Specifically, the entire surface of the glass body layer 48 is etched with an aqueous hydrogen fluoride solution until the second semiconductor layer 17 of the columnar portion 20 is exposed. As a result, as shown in FIG. 6, the second semiconductor layer 17 of the columnar portion 20 is exposed, and the first insulating portion 18 is formed between the columnar portions 20 and between the columnar portion group 25 and the structure 21. Will be done. In the present embodiment, the columnar portion group 25 and the glass body layer 48 covering the structure 21 are formed in step S3, but the present invention is not limited to this, and the columnar portion group is formed between steps S2 and S3. 25. It may have a step of forming a glass body layer 48 as an insulating film covering the structure 21. In this case, in step S3, the glass body layer 48 formed in the step of forming the glass body layer 48 is subjected to wet etching to expose the second semiconductor layer 17 on the head of the columnar portion 20 that stands in a forest. Further, the glass body layer 48 corresponds to an insulating film.

In step S4, the p-side electrode 19 is formed on the upper surface of the plurality of columnar portions 20. In a preferred example, the p-side electrode 19 is an ITO single film. The p-side electrode may have low contact resistance and translucency, and may use a thin film Pd of several nm or a metal laminated film in which Ni is in contact with the columnar portion 20. First, an ITO layer is formed on the entire surface including the columnar portion group 25 and the structure 21 by using a vapor deposition method or a sputtering method. As a result, as shown in FIG. 6, the metal layer 49 is formed on the entire surface including the columnar portion group 25 and the structure 21.

Next, as shown in FIG. 6, a resist 65 is formed on the portion of the p-side electrode 19 that becomes the light emitting region 5. Then, the p-side electrode 19 is formed on the upper surface of the plurality of columnar portions 20 by performing wet etching on the metal layer 49 using the resist 65 as a mask. In the conventional configuration in which there is a space between the columnar portions 20 that stand up, when wet etching is performed, the chemical solution infiltrates into the space between the columnar portions 20 that stand up, and the electrodes in the places where the embedding is insufficient are etched. There is a risk that the contact resistance will not increase due to the contact resistance, or that a leak will occur due to the conductive foreign matter being caught between the nanocolumns. However, according to the present embodiment, the first insulating portion 18 is in the space. Since it is filled with, wet etching can be performed without any problem. Further, it is not necessary to use dry etching, which may damage the semiconductor layer of the columnar portion 20 due to plasma charging.

In step S5, the second insulating portion 23 is formed. First, as shown in FIG. 7, the p-side electrode 19 is covered to form a resist 66 having substantially the same size as the outer circumference of the structure 21. Then, by performing wet etching using the resist 66 as a mask, the glass body layer 48 remaining on the buffer layer 11 and a part of the glass body layer 48 around the structure 21 are removed, and the structure 21 is removed. A second insulating portion 23 is formed so as to surround the side surface of the.

In step S6, the insulating layer 22 is formed. First, as shown in FIG. 8, an insulating layer 42 made of silicon dioxide that covers the entire surface including the p-side electrode 19, the structure 21, and the second insulating portion 23 is formed. In a preferred example, a plasma CVD method is used for film formation.
Then, the resist 67 is formed on the insulating layer 42. In the resist 67, the region where the n-side wiring 27 is provided is an opening. Next, the insulating layer 22 is formed by performing wet etching using the resist 67 as a mask. It is preferable to use an aqueous hydrogen fluoride solution for wet etching.

Subsequently, as shown in FIG. 9, dry etching is performed using the insulating layer 22 as a mask. As the etching gas, it is preferable to use a mixed gas of chlorine and nitrogen gas.
As a result, the surface of the buffer layer 11 is dug down in the region where the n-side wiring 27 is provided. According to the experimental results of the inventors, it has been confirmed that when the columnar portion 20 is formed, an unnecessary semiconductor layer is secondarily grown on the selection mask 12. By performing dry etching, this unnecessary semiconductor layer can also be removed.
If there is no unnecessary semiconductor layer, only the selective film needs to be removed, so wet etching may be used.

Next, as shown in FIG. 10, a resist 68 covering the insulating layer 22 is formed. The portion of the resist 68 that overlaps with the p-side electrode 19 is an opening. Then, the p-side electrode 19 is exposed by performing wet etching using the resist 68 as a mask.

In step S7, a translucent electrode layer 24 is formed on the p-side electrode 19 and over the insulating layer 22. Specifically, by forming an ITO layer on the entire surface by a thin film deposition method or a sputtering method and then performing patterning including wet etching, as shown in FIG. 11, the p-side electrode 19 and a part of the insulating layer 22 are partially formed. The electrode layer 24 that covers the surface is formed. By the steps up to this point, the laminated body 30 up to the electrode layer 24 including the columnar portion group 25 and the structure 21 is formed.

In step S8, the p-side wiring 26 and the n-side wiring 27 are formed. The p-side wiring 26 and the n-side wiring 27 are formed by forming a metal layer on the entire surface by a thin-film deposition method and then performing patterning including dry etching. In a preferred example, the p-side wiring 26 and the n-side wiring 27 have a three-layer structure of a Cr layer, a Ni layer, and an Au layer. The configuration is not limited to this, and any laminated configuration may be used as long as it is an ohmic contact.
As a result, the light emitting device 100 shown in FIGS. 1 and 2 is formed.

As described above, according to the light emitting device 100 of the present embodiment, the following effects can be obtained.
The light emitting device 100 includes a substrate 10, a columnar portion group 25 provided on the substrate 10 and composed of a plurality of columnar portions 20, a structure 21 provided on the substrate 10 and surrounding the columnar portion group 25, and a columnar portion group 25. A first insulating portion 18 provided between the structure 21 and a second insulating portion 23 surrounding the outside of the structure 21 are provided, and the columnar portion 20 includes a first semiconductor layer 15, a light emitting layer 16, and a first. The structure 21 has a semiconductor layer 15 and a second semiconductor layer 17 having a different conductive type, and the structure 21 has a third semiconductor layer 15a, a light emitting layer 16a, and a third semiconductor layer 15a having the same conductive type as the first semiconductor layer 15. It has a fourth semiconductor layer 17a having a different conductive type. In other words, the columnar portion 20 includes a first conductive type first semiconductor layer 15, a first light emitting layer 16 capable of emitting light, and a second conductive type second semiconductor layer different from the first conductive type. The structure 21 has a first conductive type third semiconductor layer 15a, a second light emitting layer 16a capable of emitting light, and a second conductive type fourth semiconductor layer 17a. ..

According to this configuration, since the columnar portion group 25 is surrounded by the structure 21, when the first insulating portion 18 is formed by the SOG method, the space between the adjacent columnar portions 20 is surely filled with the insulator. can do.
Therefore, since there is a space between the columnar portions 20 that stand up, when wet etching is performed, the chemical solution infiltrates into the space between the columnar portions 20 that stand up, and the contact resistance rises poorly and conductive foreign matter is mixed in the space. Unlike the conventional configuration in which there is a risk of leak defects due to this, according to the present embodiment, since the space is filled with the first insulating portion 18, wet etching is used to emit light with good quality. The device 100 can be manufactured. Further, it is not necessary to use dry etching, which may damage the semiconductor layer of the columnar portion 20 due to plasma charging. In other words, in each process, the light emitting device 100 can be manufactured with high quality and good yield because it can be manufactured by using the most suitable manufacturing method among a plurality of manufacturing methods including wet etching. can.
Therefore, it is possible to provide a highly reliable light emitting device 100.

Further, it further has a translucent p-side electrode 19 that covers the columnar portion group 25 and injects a current into the second semiconductor layer 17 of the columnar portion 20, and the p-side electrode 19 and the structure 21 are electrically separated. Has been done.

According to this, since the structure 21 that does not contribute to light emission is configured so that no current is supplied, there is no concern about the occurrence of leakage current, and the reliability is high.

Further, the p-side electrode 19 is provided with a p-connection terminal portion 28 to which driving power is supplied, and the p-connection terminal portion 28 is a structure 21, a first insulating portion 18, or a second insulating portion in a plan view. It is provided at a position overlapping with 23.

For example, when the p-connection terminal portion 28 is provided on a place where an unnecessary semiconductor layer is generated, the insulating layer 22 does not have a predetermined film thickness due to the shape of the unnecessary semiconductor layer, and a leakage current is generated. There is a concern. According to the above, since the p connection terminal portion 28 is provided on the electrically separated structure 21, the first insulating portion 18, or the second insulating portion 23, the connection reliability is excellent. ..

Further, the height of the structure 21 is higher than that of the columnar portion 20.
If the height of the structure 21 is low when the first insulating portion 18 is formed by the SOG method, the SOG liquid will flow out and it will be difficult to fill the columnar portion group 25.
According to this, since the SOG liquid can be stored inside the annular structure 21 which is higher than the columnar portion 20, the SOG liquid can be surely filled between the columnar portions 20 standing in the forest.

Further, the first insulating portion 18 is formed by filling the inside of the structure 21 surrounding the columnar portion group 25 with a liquid insulator and then heating the structure 21.
According to this, since the SOG liquid can be stored inside the annular structure 21 which is higher than the columnar portion 20, the SOG liquid can be surely filled between the columnar portions 20 standing in the forest.

Further, the method for manufacturing the light emitting device 100 includes a step of crystallizing a columnar portion group 25 composed of a plurality of columnar portions 20 and a structure 21 surrounding the columnar portion group 25 on the substrate 10, and the columnar portion group 25 and the columnar portion group 25. A step of forming an insulating film covering the structure 21, a step of forming a first insulating portion 18 between the columnar portion group 25 and the structure 21, and a step of forming a second insulating portion 23 surrounding the outside of the structure 21. In the step of growing a crystal, the first conductive type first semiconductor layer 15, the first light emitting layer 16 capable of emitting light, and the first light emitting layer 16 of each of the plurality of columnar portions 20 are provided. A second semiconductor layer 17 of a second conductive type different from the first conductive type is crystal-grown, and the third semiconductor layer 15a of the first conductive type of the structure 21, a second light emitting layer 16a capable of emitting light, and a second light emitting layer 16a of the structure 21 are formed. In the step of crystal-growing the second conductive type fourth semiconductor layer 17a to form the first insulating portion 18, the insulating film located in the region between the columnar portion group 25 and the structure 21 in a plan view is etched. By doing so, in the step of forming the first insulating portion 18 and forming the second insulating portion 23, the insulating film located in the outer region of the structure 21 in the plan view is etched to form the second insulating portion 23. To form.

According to this manufacturing method, since the columnar portion group 25 is surrounded by the structure 21, when the first insulating portion 18 is formed by the SOG method, the insulator is surely placed in the space between the adjacent columnar portions 20. Can be filled.
Therefore, since there is a space between the columnar portions 20 that stand up, when wet etching is performed, the chemical solution infiltrates into the space between the columnar portions 20 that stand up, and the contact resistance rises poorly and conductive foreign matter is mixed in the space. Unlike the conventional configuration in which there is a risk of leak defects due to this, according to this manufacturing method, since the space is filled with the first insulating portion 18, wet etching is used to emit light with good quality. The device 100 can be manufactured. Further, it is not necessary to use dry etching, which may damage the semiconductor layer of the columnar portion 20 due to plasma charging. In other words, in each process, the light emitting device 100 can be manufactured with high quality and good yield because it can be manufactured by using the most suitable manufacturing method among a plurality of manufacturing methods including wet etching. can.

Embodiment 2
*** Overview of the projector ***
FIG. 12 is a schematic configuration diagram of a projector according to the present embodiment.
Here, the projector 200 of the present embodiment will be described with reference to FIG.

The projector 200 includes a housing (not shown) and a red light source 110R, a green light source 110G, and a blue light source 110B that emit red light, green light, and blue light, respectively, which are provided in the housing.
The red light source 110R, the green light source 110G, and the blue light source 110B use a surface light source as an aggregate in which a plurality of light emitting devices 100 of the first embodiment are regularly arranged.

The projector 200 further includes a first optical element 50R, a second optical element 50G, a third optical element 50B, a first optical modulation device 55R, and a second optical modulation device 55G, which are provided in the housing. , A third optical modulation device 55B, and a projection device 70.
The first light modulation device 55R, the second light modulation device 55G, and the third light modulation device 55B are, for example, transmissive liquid crystal light bulbs. The projection device 70 is, for example, a projection lens.

The light emitted from the red light source 110R is incident on the first optical element 50R. The light emitted from the red light source 110R is collected by the first optical element 50R. The first optical element 50R may have a function other than focusing. The same applies to the second optical element 50G and the third optical element 50B, which will be described later.

The light collected by the first optical element 50R is incident on the first light modulator 55R. The first optical modulation device 55R modulates the incident light according to the image information. Then, the projection device 70 magnifies the image formed by the first light modulation device 55R and projects it on the screen 3.

The light emitted from the green light source 110G is incident on the second optical element 50G. The light emitted from the green light source 110G is collected by the second optical element 50G.

The light collected by the second optical element 50G is incident on the second light modulator 55G. The second light modulation device 55G modulates the incident light according to the image information. Then, the projection device 70 magnifies the image formed by the second light modulation device 55G and projects it on the screen 3.

The light emitted from the blue light source 110B is incident on the third optical element 50B. The light emitted from the blue light source 110B is collected by the third optical element 50B. The light collected by the third optical element 50B is incident on the third light modulator 55B. The third light modulation device 55B modulates the incident light according to the image information. Then, the projection device 70 magnifies the image formed by the third light modulation device 55B and projects it on the screen 3.

Further, the projector 200 includes a cross dichroic prism 60 that synthesizes the light emitted from the first light modulation device 55R, the second light modulation device 55G, and the third light modulation device 55B and guides the light emitted to the projection device 70.

The three colored lights modulated by the first light modulation device 55R, the second light modulation device 55G, and the third light modulation device 55B are incident on the cross dichroic prism 60. The cross dichroic prism 60 is formed by laminating four right-angled prisms, and a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are arranged on the inner surface thereof. Three colored lights are combined by these dielectric multilayer films to form light representing a color image. Then, the combined light is projected onto the screen 3 by the projection device 70, and an enlarged image is displayed.

The red light source 110R, the green light source 110G, and the blue light source 110B control the light emitting device 100 as a pixel of an image according to the image information, so that the first light modulation device 55R, the second light modulation device 55G, and the second light light source 110B are controlled. 3 The image may be directly formed without using the optical modulation device 55B. Then, the projection device 70 may magnify and project the image formed by the red light source 110R, the green light source 110G, and the blue light source 110B onto the screen 3.

As described above, the projector 200 uses a highly reliable light emitting device 100 as a light source. Therefore, it is possible to provide a highly reliable projector 200.

Further, in the above example, although a transmissive liquid crystal light bulb is used as the light modulation device, a light bulb other than the liquid crystal may be used, or a reflective light bulb may be used. Examples of such a light bulb include a reflective liquid crystal light bulb and a digital micromirror device. Further, the configuration of the projection device is appropriately changed depending on the type of the light bulb used.

Further, it may be applied to a light source device of a scanning type image display device that displays an image of a desired size on a display surface by scanning the light from the light source on a screen.

*** Other applications of light emitting devices ***
The light emitting device 100 according to the above-described embodiment can be used in addition to the projector. For applications other than projectors, for example, a light emitting device 100 may be used as a display panel, such as a micro LED (Light Emitting Diode). Specifically, the light emitting device 100 is miniaturized and regularly spread on a flat surface to form a display panel. For example, a light emitting device 100 having a size of several tens of μm per pixel is used. As a method of miniaturization, the individual columnar portions 20 may be miniaturized, or the number of columnar portions 20 in the columnar portion group 25 may be reduced.
Further, the light emitting device 100 may be used not only as a display panel but also as a light source for indoor / outdoor lighting, display backlights, laser printers, scanners, in-vehicle lights, sensing devices using light, communication devices, and the like. ..

3 ... screen, 5 ... light emitting region, 10 ... substrate, 11 ... buffer layer, 11b ... strain relaxation layer, 12 ... selection mask, 15 ... first semiconductor layer, 15a ... third semiconductor layer, 16 ... light emitting layer, 16a ... Light emitting layer, 17 ... 2nd semiconductor layer, 17a ... 4th semiconductor layer, 18 ... 1st insulating part, 19 ... p side electrode, 20 ... columnar part, 21 ... structure, 22 ... insulating layer, 23 ... second insulating Unit, 24 ... electrode layer, 25 ... columnar part group, 26 ... p side wiring, 27 ... n side wiring, 28 ... p connection terminal part, 29 ... n connection terminal part, 30 ... laminate, 42 ... insulating layer, 48 ... glass body layer, 50B ... third optical element, 50G ... second optical element, 50R ... first optical element, 55B ... third optical modulator, 55G ... second optical modulator, 55R ... first optical modulator, ... 60 ... Cross optic prism, 65-68 ... Resist, 70 ... Projector, 100 ... Light emitting device, 110B ... Blue light source, 110G ... Green light source, 110R ... Red light source, 200 ... Projector.

Claims (11)

With the substrate
A group of columnar portions provided on the substrate and composed of a plurality of columnar portions,
A structure provided on the substrate and surrounding the columnar portions,
A first insulating portion provided between the columnar portion group and the structure,
A second insulating portion that surrounds the outside of the structure is provided.
The columnar part is
The first conductive type first semiconductor layer and
The first light emitting layer capable of emitting light and
It has a second semiconductor layer of a second conductive type different from the first conductive type, and has.
The structure is
The first conductive type third semiconductor layer and
A second light emitting layer capable of emitting light,
It has the second conductive type fourth semiconductor layer.
Light emitting device. Further having a translucent electrode covering the columnar portion and injecting an electric current into the second semiconductor layer of the columnar portion.
The electrode and the structure are electrically separated.
The light emitting device according to claim 1. The electrode is provided with a connection terminal portion to which drive power is supplied.
In a plan view, the connection terminal portion is provided at a position overlapping the structure, the first insulating portion, or the second insulating portion.
The light emitting device according to claim 2. The height of the structure is higher than that of the columnar portion.
The light emitting device according to any one of claims 1 to 3. The height of the first insulating portion is equal to or higher than the height of the columnar portion.
The light emitting device according to claim 4. A projector provided with the light emitting device according to any one of claims 1 to 5. A step of crystal-grow a columnar portion group composed of a plurality of columnar portions and a structure surrounding the columnar portion group on the substrate.
A step of forming an insulating film covering the columnar portions and the structure, and
A step of forming a first insulating portion between the columnar portion group and the structure,
It has a step of forming a second insulating portion that surrounds the outside of the structure.
In the process of crystal growth,
Each of the plurality of columnar portions has a first conductive type first semiconductor layer, a first light emitting layer capable of emitting light, and a second conductive type second semiconductor layer different from the first conductive type. Crystal growth,
The first conductive type third semiconductor layer, the second light emitting layer capable of emitting light, and the second conductive type fourth semiconductor layer of the structure are crystal-grown.
In the step of forming the first insulating portion, the first insulating portion is formed by etching the insulating film located in the region between the columnar portion group and the structure in a plan view.
A method for manufacturing a light emitting device, which forms the second insulating portion by etching the insulating film located in the outer region of the structure in the plan view in the step of forming the second insulating portion. After the step of forming the first insulating portion, a step of forming a translucent electrode covering the columnar portion group is further included.
In the step of forming the electrode,
The electrode and the columnar portion group are electrically connected, and the
Electrically separating the electrode and the structure,
The method for manufacturing a light emitting device according to claim 7. Further, the electrode is further provided with a step of forming a connection terminal portion to which driving power is supplied.
In the step of forming the connection terminal portion, the connection terminal portion is provided at a position where it overlaps with the structure, the first insulating portion, or the second insulating portion in the plan view.
The method for manufacturing a light emitting device according to claim 8. In the crystal growth step, the structure is grown higher than the columnar portion.
The method for manufacturing a light emitting device according to any one of claims 7 to 9. In the step of forming the insulating film, the insulating film is formed by applying a liquid insulator to the columnar portions and the structure and then heating the liquid insulator.
The method for manufacturing a light emitting device according to any one of claims 7 to 10.

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