Light-emitting device, projector, and display

Abstract

To provide a light-emitting device capable of reducing a possibility for a leak current to flow between a first columnar part and a wire.SOLUTION: The present invention relates to a light-emitting device comprising: a substrate; a plurality of first columnar parts provided in the substrate; a plurality of second columnar parts provided in the substrate and enclosing the plurality of first columnar parts in a view in a normal direction of the substrate; a first semiconductor layer connected to the plurality of first columnar parts; an insulation layer covering the first semiconductor layer and the plurality of second columnar parts; and a wire electrically connected with the first semiconductor layer. Each of the plurality of first columnar parts and each of the plurality of second columnar parts include an n-type second semiconductor layer, a p-type third semiconductor layer and a u-type fourth semiconductor layer. The fourth semiconductor layer in each of the plurality of first columnar part is injected with current and emit light. Current is not injected to the fourth semiconductor layer in each of the plurality of second columnar parts. The wire is overlapped with at least one of the plurality of second columnar parts in the view in the normal direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a light-emitting device, a projector, and a display. [Background technology]

[0002] Semiconductor lasers are expected to be the next generation of high-brightness light sources. In particular, semiconductor lasers that incorporate nanocolumns are expected to be able to emit high-power light with a narrow beam angle due to the photonic crystal effect of the nanocolumns.

[0003] For example, Patent Document 1 describes a method for manufacturing a light-emitting device, which includes the steps of growing nanowires, forming an encapsulation layer to cover the free ends of the nanowires, forming a second electrode on the encapsulation layer, masking the second electrode, and etching the unmasked second electrode, the encapsulation layer, and the nanowires to separate basic light-emitting regions. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2013-502715 Summary of the Invention [Problem to be solved by the invention]

[0005] In the light-emitting device described above, when wiring connecting to the second electrode is routed, an insulating layer is formed to cover the basic light-emitting region to prevent contact between the wiring and the nanowires in the basic light-emitting region. However, in Patent Document 1, there are areas between adjacent basic light-emitting regions where the nanowires have been removed, resulting in a step between the areas and the basic light-emitting region. When a step occurs, the insulating layer does not adhere well, causing leakage current to flow between the wiring and the nanowires in the basic light-emitting region. [Means for solving the problem]

[0006] One aspect of the light emitting device according to the present invention is A substrate; a plurality of first columnar portions provided on the substrate; a plurality of second columnar sections provided on the substrate and surrounding the plurality of first columnar sections when viewed in a normal direction of the substrate; a first semiconductor layer provided on the opposite side of the plurality of first columnar sections from the substrate and connected to the plurality of first columnar sections; an insulating layer covering the first semiconductor layer and the plurality of second columnar sections; a wiring provided on the insulating layer opposite the substrate and electrically connected to the first semiconductor layer; and Each of the plurality of first columnar portions and each of the plurality of second columnar portions are an n-type second semiconductor layer; a p-type third semiconductor layer; a u-type fourth semiconductor layer provided between the second semiconductor layer and the third semiconductor layer; and the fourth semiconductor layer in each of the plurality of first columnar sections emits light when a current is injected into it; no current is injected into the fourth semiconductor layer in each of the plurality of second columnar sections, When viewed from the normal direction, the wiring overlaps with at least one of the plurality of second columnar portions. are.

[0007] One aspect of the projector according to the present invention is The light emitting device has one aspect.

[0008] One aspect of the display according to the present invention is The light emitting device has one aspect. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a plan view schematically showing a light emitting device according to a first embodiment. [Figure 2]FIG. 1 is a cross-sectional view schematically showing a light emitting device according to a first embodiment. [Figure 3] FIG. 1 is a cross-sectional view schematically showing a light emitting device according to a first embodiment. [Figure 4] FIG. 1 is a cross-sectional view schematically showing a light emitting device according to a first embodiment. [Figure 5] 3A to 3C are cross-sectional views schematically showing the manufacturing process of the light emitting device according to the first embodiment. [Figure 6] 3A to 3C are cross-sectional views schematically showing the manufacturing process of the light emitting device according to the first embodiment. [Figure 7] FIG. 1 is a plan view schematically showing a light emitting device according to a first reference example. [Figure 8] FIG. 1 is a cross-sectional view schematically showing a light emitting device according to a first reference example. [Figure 9] FIG. 10 is a plan view schematically showing a light emitting device according to a second embodiment. [Figure 10] FIG. 10 is a cross-sectional view schematically showing a light emitting device according to a second embodiment. [Figure 11] FIG. 10 is a cross-sectional view schematically showing a light emitting device according to a second embodiment. [Figure 12] FIG. 10 is a cross-sectional view schematically showing a light emitting device according to a second reference example. [Figure 13] FIG. 10 is a plan view schematically showing a light emitting device according to a third embodiment. [Figure 14] FIG. 10 is a cross-sectional view schematically showing a light emitting device according to a third embodiment. [Figure 15] FIG. 10 is a diagram schematically showing a projector according to a fourth embodiment. [Figure 16] FIG. 10 is a plan view schematically showing a display according to a fifth embodiment. [Figure 17] FIG. 10 is a cross-sectional view schematically showing a display according to a fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Preferred embodiments of the present invention will be described in detail below with reference to the drawings. Note that the embodiments described below do not unduly limit the content of the present invention as defined in the claims. Furthermore, not all of the configurations described below are necessarily essential components of the present invention.

[0011] 1. First embodiment 1.1. Light-emitting device First, the light emitting device according to the first embodiment will be described with reference to the drawings. FIG. 1 is a plan view schematically showing the light emitting device 100 according to the first embodiment. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1, schematically showing the light emitting device 100 according to the first embodiment. FIG. 3 is a cross-sectional view schematically showing the light emitting device 100 according to the first embodiment, and is an enlarged view of region A1 in FIG. 2. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 1, schematically showing the light emitting device 100 according to the first embodiment. Note that in FIGS. 1 to 4, an X-axis, a Y-axis, and a Z-axis are shown as three mutually orthogonal axes.

[0012] As shown in Figures 1 to 4, the light emitting device 100 includes, for example, a substrate 10, a laminate 20, a first semiconductor layer 40, a first electrode 50, a second electrode 52, an insulating layer 60, a first wiring 70, a second wiring 72, and a pad 80.

[0013] The substrate 10 is, for example, a Si substrate, a GaN substrate, a sapphire substrate, or a SiC substrate.

[0014] The stacked body 20 is provided on the substrate 10. In the illustrated example, the stacked body 20 is provided on the substrate 10. The stacked body 20 has, for example, a buffer layer 22 and a plurality of columnar sections 30. The columnar sections 30 have an n-type second semiconductor layer (hereinafter also referred to as an "n-type semiconductor layer 32"), a p-type third semiconductor layer (hereinafter also referred to as a "p-type semiconductor layer 36"), and a u-type fourth semiconductor layer (hereinafter also referred to as a "u-type semiconductor layer 34"). For convenience, FIG. 2 illustrates the columnar section 30 in a simplified manner. Furthermore, FIG. 3 omits illustration of components other than the columnar section 30, the first semiconductor layer 40, and the second electrode 52.

[0015] In this specification, in the stacking direction of the laminate 20 (hereinafter also simply referred to as the "stacking direction"), when the u-type semiconductor layer 34 is used as a reference, the direction from the u-type semiconductor layer 34 toward the p-type semiconductor layer 36 is referred to as the "upper" direction, and the direction from the u-type semiconductor layer 34 toward the n-type semiconductor layer 32 is referred to as the "lower" direction. A direction perpendicular to the stacking direction is also referred to as an "in-plane direction." The "stacking direction of the laminate 20" refers to the stacking direction of the n-type semiconductor layer 32 and the u-type semiconductor layer 34, and is the direction of the normal N to the substrate 10. In the illustrated example, the stacking direction is the Z-axis direction.

[0016] The buffer layer 22 is provided on the substrate 10. The buffer layer 22 is, for example, an n-type GaN layer doped with Si. Although not shown, a mask layer for growing the columnar section 30 is provided on the buffer layer 22. The mask layer is, for example, a silicon oxide layer, a titanium layer, a titanium oxide layer, an aluminum oxide layer, or the like.

[0017] The columnar portion 30 is provided on the buffer layer 22. The columnar portion 30 has a columnar shape that protrudes upward from the buffer layer 22. In other words, the columnar portion 30 protrudes upward from the substrate 10 via the buffer layer 22. The columnar portion 30 is also called, for example, a nanocolumn, a nanowire, a nanorod, or a nanopillar. The planar shape of the columnar portion 30 is, for example, a polygon such as a hexagon, or a circle.

[0018] The diameter of the columnar section 30 is, for example, 50 nm or more and 500 nm or less. By setting the diameter of the columnar section 30 to 500 nm or less, a u-type semiconductor layer 34 with high-quality crystals can be obtained, and strain inherent in the u-type semiconductor layer 34 can be reduced. This allows light generated in the u-type semiconductor layer 34 to be amplified with high efficiency.

[0019] The "diameter of the columnar portion" refers to the diameter when the planar shape of the columnar portion 30 is circular, and refers to the diameter of the smallest encompassing circle when the planar shape of the columnar portion 30 is not circular. For example, when the planar shape of the columnar portion 30 is polygonal, the diameter of the columnar portion 30 refers to the diameter of the smallest circle that includes the polygon inside, and when the planar shape of the columnar portion 30 is elliptical, the diameter of the smallest circle that includes the ellipse inside.

[0020] A plurality of columnar sections 30 are provided. The interval between adjacent columnar sections 30 is, for example, 1 nm or more and 500 nm or less. The plurality of columnar sections 30 are arranged in a predetermined direction at a predetermined pitch when viewed from the stacking direction. The plurality of columnar sections 30 are arranged, for example, in a triangular lattice pattern or a square lattice pattern. The plurality of columnar sections 30 can exhibit the effect of a photonic crystal.

[0021] The "pitch of the columnar portions" refers to the distance between the centers of adjacent columnar portions 30 along a predetermined direction. When the planar shape of the columnar portions 30 is a circle, the "center of the columnar portion" refers to the center of the circle. When the planar shape of the columnar portions 30 is not a circle, the "center of the columnar portion" refers to the center of the smallest encompassing circle. For example, when the planar shape of the columnar portions 30 is a polygon, the center of the smallest circle that contains the polygon within itself. When the planar shape of the columnar portions 30 is an ellipse, the center of the smallest circle that contains the ellipse within itself.

[0022] The n-type semiconductor layer 32 of the columnar section 30 is provided on the buffer layer 22. The layer 32 is provided between the substrate 10 and the u-type semiconductor layer 34. The n-type semiconductor layer 32 is, for example, an n-type GaN layer doped with Si.

[0023] The u-type semiconductor layer 34 of the columnar section 30 is provided on the n-type semiconductor layer 32. The u-type semiconductor layer 34 is provided between the n-type semiconductor layer 32 and the p-type semiconductor layer 36. The u-type semiconductor layer 34 is an undoped semiconductor layer that is not intentionally doped with impurities. The u-type semiconductor layer 34 may be an i-type semiconductor layer made of an intrinsic semiconductor. The u-type semiconductor layer 34 has, for example, a well layer and a barrier layer. The well layer is, for example, an InGaN layer. The barrier layer is, for example, a GaN layer. The u-type semiconductor layer 34 has an MQW (Multiple Quantum Well) structure composed of the well layer and the barrier layer.

[0024] There is no particular limitation on the number of well layers and barrier layers that constitute the u-type semiconductor layer 34. For example, only one well layer may be provided, in which case the u-type semiconductor layer 34 has an SQW (Single Quantum Well) structure.

[0025] The p-type semiconductor layer 36 of the columnar section 30 is provided on the u-type semiconductor layer 34. The p-type semiconductor layer 36 is, for example, a p-type GaN layer doped with Mg.

[0026] Of the multiple columnar sections 30, the first columnar section 30a is a columnar section that emits light when a current is injected. Of the multiple columnar sections 30, the second columnar section 30b is a columnar section that is not injected with a current. A plurality of first columnar sections 30a are provided. A plurality of second columnar sections 30b are provided. The multiple first columnar sections 30a and the multiple second columnar sections 30b are provided on the substrate 10. In the example shown in FIG. 2, the multiple first columnar sections 30a and the multiple second columnar sections 30b are provided on the substrate 10 via a buffer layer 22. The buffer layer 22 has, for example, a first region 24 in which the multiple first columnar sections 30a are provided and a second region 26 in which the multiple second columnar sections 30b are provided. The first region 24 and the second region 26 are on the upper surface of the buffer layer 22 and are in contact with each other. When viewed from the stacking direction, the second region 26 surrounds the first region 24. When viewed from the stacking direction, the multiple second columnar sections 30b surround the multiple first columnar sections 30a.

[0027] In the example shown in Fig. 3, the multiple second columnar sections 30b are provided contiguous with the multiple first columnar sections 30a. That is, the distance between the second columnar section 30b1 and the first columnar section 30a1 is the same as the distance between the second columnar section 30b1 and the second columnar section 30b2. The second columnar section 30b1 is a columnar section adjacent to the first columnar section 30a1. The first columnar section 30a1 is the outermost columnar section of the multiple first columnar sections 30a. The second columnar section 30b2 is a columnar section adjacent to the second columnar section 30b1.

[0028] The diameter of the first columnar section 30a and the diameter of the second columnar section 30b are, for example, the same. The pitch of the multiple first columnar sections 30a and the pitch of the multiple second columnar sections 30b are, for example, the same. The height of the first columnar section 30a and the height of the second columnar section 30b are, for example, the same. Note that the "height of the columnar section" refers to the size of the columnar section 30 in the stacking direction.

[0029] Each of the multiple first columnar sections 30a and each of the multiple second columnar sections 30b has an n-type semiconductor layer 32, a u-type semiconductor layer , and a p-type semiconductor layer .

[0030] The u-type semiconductor layer 34 in each of the multiple first columnar sections 30a emits light when a current is injected by the first electrode 50 and the second electrode 52. The u-type semiconductor layer 34 of the first columnar section 30a is a light-emitting layer that generates light.

[0031] No current is injected into the u-type semiconductor layer 34 in each of the multiple second columnar sections 30b. Therefore, the u-type semiconductor layer 34 of the second columnar section 30b does not emit light. In the example shown in Figure 3, the p-type semiconductor layer 36 of the second columnar section 30b is electrically isolated from the second electrode 52.

[0032] In the light-emitting device 100, a p-i-n diode is formed by the p-type semiconductor layer 36 of the first columnar section 30a, the u-type semiconductor layer 34 of the first columnar section 30a, and the n-type semiconductor layer 32 of the first columnar section 30a. In the light-emitting device 100, when a forward bias voltage of the p-i-n diode is applied between the first electrode 50 and the second electrode 52, current is injected into the u-type semiconductor layer 34 of the first columnar section 30a, causing recombination of electrons and holes in the u-type semiconductor layer 34 of the first columnar section 30a. This recombination generates light. Light generated in the u-type semiconductor layer 34 of the first columnar section 30a propagates in the in-plane direction and forms a standing wave due to the photonic crystal effect of the multiple first columnar sections 30a. The light then receives gain in the u-type semiconductor layer 34 of the first columnar section 30a and undergoes laser oscillation. The light emitting device 100 then emits the +1st order diffracted light and the −1st order diffracted light as laser light in the stacking direction.

[0033] Although not shown, a reflective layer may be provided between the substrate 10 and the buffer layer 22 or below the substrate 10. The reflective layer is, for example, a DBR (Distributed Bragg Reflector) layer. The reflective layer can reflect light generated in the u-type semiconductor layer 34 of the first columnar section 30a, and the light emitting device 100 can emit light only from the second electrode 52 side.

[0034] The first semiconductor layer 40 is provided on the side of the multiple first columnar sections 30a opposite to the substrate 10 side. The first semiconductor layer 40 is provided on the multiple first columnar sections 30a. The first semiconductor layer 40 is provided between the multiple first columnar sections 30a and the second electrode 52. The first semiconductor layer 40 is connected to the multiple first columnar sections 30a. The thickness of the first semiconductor layer 40 is, for example, several tens of nanometers. The first semiconductor layer 40 has the same conductivity type as the semiconductor layer in contact with the first columnar section 30a. In the example shown in FIG. 1, the first semiconductor layer 40 is in contact with the p-type semiconductor layer 36 of the first columnar section 30a. The first semiconductor layer 40 is, for example, a p-type GaN layer doped with Mg. In the example shown in FIG. 1, the planar shape of the first semiconductor layer 40 is circular.

[0035] As shown in FIG. 4, the first electrode 50 is provided on the buffer layer 22. The buffer layer 22 may be in ohmic contact with the first electrode 50. The first electrode 50 is electrically connected to the n-type semiconductor layer 32 of the first columnar section 30a. In the example shown in the figure, the first electrode 50 is electrically connected to the n-type semiconductor layer 32 of the first columnar section 30a via the buffer layer 22. The first electrode 50 is one of the electrodes used to inject current into the u-type semiconductor layer 34 of the first columnar section 30a. The first electrode 50 may be, for example, a layer formed by laminating a Cr layer, a Ni layer, and an Au layer in this order from the buffer layer 22 side.

[0036] 2 and 3, the second electrode 52 is provided on the side of the first semiconductor layer 40 opposite the substrate 10. The second electrode 52 is provided on the first semiconductor layer 40. The second electrode 52 is provided between the first semiconductor layer 40 and the second wiring 72. The first semiconductor layer 40 may be in ohmic contact with the second electrode 52.

[0037] As shown in FIG. 1, the second electrode 52 completely overlaps the first semiconductor layer 40 when viewed from the stacking direction. That is, when viewed from the stacking direction, the second electrode 52 does not have a portion that does not overlap with the first semiconductor layer 40, and the first semiconductor layer 40 does not have a portion that does not overlap with the second electrode 52. In the example shown, the second electrode 52 has a circular planar shape. The second electrode 52 is electrically connected to the p-type semiconductor layer 36 of the first columnar section 30a. In the example shown, the second electrode 52 is electrically connected to the p-type semiconductor layer 36 of the first columnar section 30a via the first semiconductor layer 40. The second electrode 52 injects a current into the u-type semiconductor layer 34 of the first columnar section 30a. The second electrode 52 is the other electrode for introducing light. The second electrode 52 is made of, for example, ITO (Indium Tin Oxide) or ZnO.

[0038] The second electrode 52, the first electrode 50, the first semiconductor layer 40, the multiple first columnar sections 30a, and the buffer layer 22 constitute, for example, a light-emitting element 102. The light-emitting element 102 is a semiconductor laser. For example, multiple light-emitting elements 102 are provided. In the example shown in FIG. 1, four light-emitting elements 102 are provided, but the number is not particularly limited. The multiple light-emitting elements 102 are arranged in a matrix in the X-axis direction and the Y-axis direction, for example. The buffer layer 22 is a layer common to the multiple light-emitting elements 102. The first electrode 50 is an electrode common to the multiple light-emitting elements 102. Multiple second columnar sections 30b are provided between adjacent light-emitting elements 102. When viewed from the stacking direction, the multiple second columnar sections 30b surround the light-emitting element 102.

[0039] 2, the insulating layer 60 covers the first semiconductor layer 40 and the multiple second columnar sections 30b. In the illustrated example, the insulating layer 60 covers the first semiconductor layer 40 via the second electrode 52. The insulating layer 60 is provided on the multiple second columnar sections 30b, the first electrode 50, and the second electrode 52. The insulating layer 60 is, for example, a silicon oxide layer or a silicon nitride layer.

[0040] As shown in Fig. 4, a first contact hole 62 is provided in the insulating layer 60. When viewed from the stacking direction, the first contact hole 62 overlaps with the first electrode 50. When viewed from the stacking direction, a second contact hole 64 is provided in the insulating layer 60. When viewed from the stacking direction, the second contact hole 64 overlaps with the second electrode 52.

[0041] 4, the first wiring 70 is provided on the first electrode 50 and the insulating layer 60. The first wiring 70 is connected to the first electrode 50 via a first contact hole 62 provided in the insulating layer 60. The first wiring 70 may be, for example, a Cu layer, an Al layer, or an Au layer.

[0042] As shown in FIG. 2 , the second wiring 72 is provided on the insulating layer 60 on the opposite side to the substrate 10. The second wiring 72 is provided on the second electrode 52 and on the insulating layer 60. The second wiring 72 is connected to the second electrode 52 via a second contact hole 64 provided in the insulating layer 60. The second wiring 72 is electrically connected to the first semiconductor layer 40. In the example shown in the figure, the second wiring 72 is electrically connected to the first semiconductor layer 40 via the second electrode 52. A plurality of second wirings 72 are provided corresponding to the plurality of light-emitting elements 102.

[0043] The second wiring 72 has, for example, a first layer 74 and a second layer 76. The first layer 74 is provided on the upper surface of the second electrode 52, on the side surface of the insulating layer 60 that defines the second contact hole 64, and on the upper surface of the insulating layer 60. In the example shown in FIG. 1 , the first layer 74 has a circular planar shape. The first layer 74 is made of, for example, ITO or ZnO. The second layer 76 is provided on the upper surface of the insulating layer 60. The second layer 76 connects the first layer 74 and the pad 80. The second layer 76 has a substantially rectangular planar shape. The second layer 76 is made of, for example, a Cu layer, an Al layer, or an Au layer.

[0044] The second wiring 72 overlaps with at least one of the multiple second columnar sections 30b when viewed from the stacking direction. In the example shown, the second layer 76 of the second wiring 72 overlaps with the multiple second columnar sections 30b when viewed from the stacking direction. The second layer 76 of the second wiring 72 overlaps with the second region 26 when viewed from the stacking direction.

[0045] The pad 80 is provided on the insulating layer 60. The pad 80 may include, for example, a wire (not shown). Ear bonding is connected. The planar shape of the pad 80 is rectangular. The size of the pad 80 in the Y-axis direction is larger than the size of the second layer 76 in the Y-axis direction. A plurality of pads 80 are provided corresponding to the plurality of light-emitting elements 102. The material of the pad 80 is, for example, the same as that of the second layer 76.

[0046] Although the above description has been given of the case where the u-type semiconductor layer 34 of the first columnar section 30a is InGaN-based, various material systems that can emit light when a current is injected can be used for the u-type semiconductor layer 34 of the first columnar section 30a, depending on the wavelength of the emitted light. For example, semiconductor materials such as AlGaN-based, AlGaAs-based, InGaAs-based, InGaAsP-based, InP-based, GaP-based, and AlGaP-based materials can be used.

[0047] Furthermore, the light emitting element 102 is not limited to a laser, but may be an LED (Light Emitting Diode).

[0048] 1.2. Light-emitting device manufacturing method Next, a method for manufacturing the light emitting device 100 according to the first embodiment will be described with reference to the drawings. Figures 5 and 6 are cross-sectional views that schematically show the manufacturing process of the light emitting device 100 according to the first embodiment.

[0049] 5, a buffer layer 22 is epitaxially grown on a substrate 10. Examples of methods for epitaxial growth include MOCVD (Metal Organic Chemical Vapor Deposition) and MBE (Molecular Beam Epitaxy).

[0050] Next, a mask layer (not shown) is formed on the buffer layer 22. The mask layer is formed by film formation using, for example, electron beam evaporation or sputtering, and patterning. The patterning is performed by, for example, electron beam lithography and dry etching.

[0051] Next, using the mask layer as a mask, an n-type semiconductor layer 32, a u-type semiconductor layer 34, and a p-type semiconductor layer 36 are epitaxially grown in this order on the buffer layer 22. Examples of methods for epitaxial growth include MOCVD and MBE. This process allows the formation of multiple columnar sections 30.

[0052] As shown in Fig. 6, a first semiconductor layer 40 is formed on the multiple first columnar sections 30a. Specifically, the first semiconductor layer 40 is epitaxially grown. Examples of methods for epitaxially growing the first semiconductor layer 40 include MOCVD and MBE. The growth of the first semiconductor layer 40 is performed under conditions that make it easier for the layer to spread laterally than the growth of the columnar sections 30.

[0053] Next, the second electrode 52 is formed on the first semiconductor layer 40. The second electrode 52 is formed by, for example, film formation using a sputtering method or a vacuum deposition method, and patterning. The patterning is performed by, for example, photolithography and etching. By this etching, the second electrode 52 and the first semiconductor layer 40 can be etched at the same time.

[0054] As shown in FIG. 4, a first electrode 50 is formed on the buffer layer 22. The first electrode 50 is formed by film formation using, for example, a sputtering method or a vacuum deposition method, and patterning. The patterning is performed by, for example, photolithography and etching. This process can form a plurality of light-emitting elements 102. The order of the process of forming the first electrode 50 and the process of forming the second electrode 52 is not particularly limited.

[0055] As shown in FIGS. 2 and 4, a plurality of second columnar sections 30b, a first electrode 50, and a second electrode An insulating layer 60 is formed to cover the electrode 52. The insulating layer 60 is formed by, for example, a CVD (Chemical Vapor Deposition) method or a spin coating method.

[0056] Next, the insulating layer 60 is patterned to form a first contact hole 62 and a second contact hole 64. The patterning is performed by, for example, photolithography and etching.

[0057] 2, a first layer 74 is formed on the second electrode 52. Next, a second layer 76 and a pad 80 are formed on the insulating layer 60. The first layer 74, the second layer 76, and the pad 80 are formed by, for example, sputtering or vacuum deposition. This process allows the second wiring 72 having the first layer 74 and the second layer 76 to be formed.

[0058] 1, a first wiring 70 is formed to connect to the first electrode 50. The first wiring 70 is formed by, for example, a sputtering method or a vacuum deposition method. The order of the step of forming the first wiring 70 and the step of forming the second wiring 72 is not particularly limited.

[0059] Through the above steps, the light emitting device 100 can be manufactured.

[0060] 1.3. Effects In the light emitting device 100, the multiple second columnar sections 30b surround the multiple first columnar sections 30a when viewed from the stacking direction, so the step where the insulating layer 60 is provided can be reduced. Therefore, in the light emitting device 100, the adhesion of the insulating layer 60 can be improved. This reduces the possibility of contact between the first columnar section 30a and the second wiring 72. As a result, it reduces the possibility of leakage current flowing between the first columnar section 30a and the second wiring 72. Furthermore, it reduces the possibility of the second wiring 72 being disconnected.

[0061] Furthermore, in the light emitting device 100, each of the multiple first columnar sections 30a and each of the multiple second columnar sections 30b has an n-type semiconductor layer 32, a u-type semiconductor layer 34, and a p-type semiconductor layer 36. Therefore, in the light emitting device 100, the difference in height between the first columnar section 30a and the second columnar section 30b can be made smaller than when, for example, the second columnar section does not have a p-type semiconductor layer. This makes it possible to reduce the step in the portion where the insulating layer 60 is provided.

[0062] Here, Fig. 7 is a plan view schematically showing the light emitting device 1000 according to the first reference example, and Fig. 8 is a cross-sectional view taken along line VIII-VIII in Fig. 7, schematically showing the light emitting device 1000 according to the first reference example.

[0063] In the manufacturing method of the light emitting device 1000, after growing the multiple columnar portions 1030, the columnar portions 1030 other than those connected to the first semiconductor layer 1040 are etched. This causes a step between the region where the multiple columnar portions 1030 are provided and the region where no columnar portions 1030 are provided. This step also causes a step in the insulating layer 1060. The step portion 1062 of the insulating layer 1060 is likely to be thinner than other portions and is prone to damage such as cracks due to stress. This makes it easier for leakage current to flow between the second wiring 1072 connected to the second electrode 1052 and the columnar portions 1030.

[0064] Furthermore, in the method for manufacturing the light emitting device 1000, etching residues 1031 may be generated when etching the columnar section 1030. If etching residues 1031 are generated, leakage current may flow between the second wiring 1072 and the etching residues 1031, which may result in light emission from unintended locations.

[0065] As described above, the light emitting device 100 has a plurality of second columnar sections 30b that do not emit light and surround a plurality of first columnar sections 30a when viewed in the stacking direction, and therefore can solve the above problem.

[0066] The light emitting device 100 has a second electrode 52 provided on the side of the first semiconductor layer 40 opposite the substrate 10, and the second wiring 72 is connected to the second electrode 52 via a second contact hole 64 provided in the insulating layer 60. Therefore, in the light emitting device 100, it is possible to prevent the electrode material from seeping in between adjacent first columnar portions, compared to when the second electrode is provided directly on multiple first columnar portions. Furthermore, it is possible to improve the flatness of the second electrode 52.

[0067] In the light emitting device 100, the second electrode 52 completely overlaps the first semiconductor layer 40 when viewed in the stacking direction. Therefore, in the light emitting device 100, etching of the first semiconductor layer 40 and etching of the second electrode 52 can be performed simultaneously in the same process. This allows for shortening of the manufacturing process. Note that etching of the first semiconductor layer 40 and etching of the second electrode 52 may be performed in separate processes.

[0068] 2. Second embodiment 2.1. Light-emitting device Next, a light emitting device according to a second embodiment will be described with reference to the drawings. FIG. 9 is a plan view schematically showing a light emitting device 200 according to the second embodiment. FIG. 10 is a cross-sectional view taken along line XX in FIG. 9, which schematically shows the light emitting device 200 according to the second embodiment. FIG. 11 is a cross-sectional view schematically showing the light emitting device 200 according to the second embodiment, and is an enlarged view of region A2 in FIG. 10. For convenience, FIG. 10 illustrates a simplified view of the columnar section 30. Furthermore, FIG. 11 omits illustration of components other than the columnar section 30, the insulating layer 60, and the fifth semiconductor layer 90.

[0069] Hereinafter, in the light emitting device 200 according to the second embodiment, components having the same functions as those of the light emitting device 100 according to the first embodiment described above will be denoted by the same reference numerals, and detailed description thereof will be omitted. This also applies to the light emitting device according to the third embodiment described below.

[0070] As shown in FIGS. 9 to 11, the light emitting device 200 differs from the light emitting device 100 described above in that a fifth semiconductor layer 90 is provided.

[0071] As shown in FIGS. 10 and 11, the fifth semiconductor layer 90 is provided on the side of the multiple second columnar sections 30b opposite the substrate 10. The fifth semiconductor layer 90 is provided on the multiple second columnar sections 30b. The fifth semiconductor layer 90 is provided between the multiple second columnar sections 30b and the insulating layer 60. The fifth semiconductor layer 90 is connected to the multiple second columnar sections 30b.

[0072] The fifth semiconductor layer 90 is electrically isolated from the first semiconductor layer 40. In the illustrated example, the fifth semiconductor layer 90 is separated from the first semiconductor layer 40. When viewed from the stacking direction, the fifth semiconductor layer 90 surrounds the first semiconductor layer 40. The fifth semiconductor layer 90 is electrically isolated from the second electrode 52. The thickness of the fifth semiconductor layer 90 is, for example, the same as the thickness of the first semiconductor layer 40. The material of the fifth semiconductor layer 90 is, for example, the same as that of the first semiconductor layer 40.

[0073] 2.2. Light-emitting device manufacturing method Next, a method for manufacturing the light emitting device 200 according to the second embodiment will be described with reference to the drawings. The method for manufacturing the light emitting device 200 includes the steps of: forming a first semiconductor layer 40 and a fifth semiconductor layer 41; Except for the fact that the conductive layer 90 is formed in the same process as the conductive layer 90, the manufacturing method is basically the same as the manufacturing method for the light emitting device 100 described above. Therefore, detailed description thereof will be omitted.

[0074] 2.3. Effects The light emitting device 200 has a fifth semiconductor layer 90 that is provided on the side of the plurality of second columnar sections 30b opposite the substrate 10 and connected to the plurality of second columnar sections 30b, and the fifth semiconductor layer 90 is electrically isolated from the first semiconductor layer 40. Therefore, in the light emitting device 200, the flatness of the upper surface of the insulating layer 60 can be improved. This can further reduce the possibility of disconnection of the second wiring 72.

[0075] 12, the insulating layer 2060 may get into the gaps between adjacent second columnar sections 2030b, forming recesses 2062 on the upper surface of the insulating layer 2060. This may reduce the flatness of the upper surface of the insulating layer 2060. Note that FIG. 12 is a cross-sectional view schematically showing a light emitting device 2000 according to a second reference example.

[0076] In the light emitting device 200, the thickness of the fifth semiconductor layer 90 is the same as the thickness of the first semiconductor layer 40, and the thickness of the fifth semiconductor layer 90 is the same as the thickness of the first semiconductor layer 40. Therefore, in the light emitting device 200, for example, the first semiconductor layer 40 and the fifth semiconductor layer 90 can be formed in the same process. This allows the manufacturing process to be shortened.

[0077] 3. Third embodiment 3.1. Light-emitting device Next, a light emitting device according to a third embodiment will be described with reference to the drawings. Fig. 13 is a plan view schematically showing a light emitting device 300 according to the third embodiment. Fig. 14 is a cross-sectional view schematically showing the light emitting device 300 according to the third embodiment. For convenience, Fig. 13 omits illustration of components other than the first semiconductor layer 40 and the second electrode 52. Fig. 14 also shows a simplified illustration of the columnar section 30.

[0078] In the light emitting device 100 described above, as shown in FIGS. 1 and 2, the second electrode 52 completely overlaps the first semiconductor layer 40 when viewed in the stacking direction.

[0079] 13 and 14, in the light emitting device 300, the second electrode 52 is provided inside the outer edge 42 of the first semiconductor layer 40 when viewed in the stacking direction. The second electrode 52 does not overlap with the outer edge 42.

[0080] 3.2. Light-emitting device manufacturing method Next, a description will be given of a method for manufacturing the light emitting device 300 according to the third embodiment. The method for manufacturing the light emitting device 300 is basically the same as the method for manufacturing the light emitting device 100 described above. Therefore, a detailed description thereof will be omitted.

[0081] 3.3. Effects In the light emitting device 300, the second electrode 52 is provided inside the outer edge 42 of the first semiconductor layer 40 when viewed from the stacking direction, and does not overlap with the outer edge 42. Therefore, in the light emitting device 300, there can be more leeway in the precision of the manufacturing process compared to, for example, a case where the second electrode is formed so as to completely overlap with the first semiconductor layer when viewed from the stacking direction.

[0082] 4. Fourth embodiment Next, a projector according to a fourth embodiment will be described with reference to the drawings. Fig. 15 is a diagram schematically showing a projector 800 according to the fourth embodiment.

[0083] The projector 800 includes, for example, a light emitting device 100 as a light source.

[0084] Projector 800 has a housing (not shown) and red light source 100R, green light source 100G, and blue light source 100B that are provided in the housing and emit red light, green light, and blue light, respectively. For convenience, red light source 100R, green light source 100G, and blue light source 100B are simplified in FIG. 15.

[0085] The projector 800 further includes, within the housing, a first optical element 802R, a second optical element 802G, a third optical element 802B, a first light modulation device 804R, a second light modulation device 804G, a third light modulation device 804B, and a projection device 808. The first light modulation device 804R, the second light modulation device 804G, and the third light modulation device 804B are, for example, transmissive liquid crystal light valves. The projection device 808 is, for example, a projection lens.

[0086] Light emitted from red light source 100R is incident on first optical element 802R. The light emitted from red light source 100R is collected by first optical element 802R. Note that first optical element 802R may have a function other than collecting light. The same applies to second optical element 802G and third optical element 802B, which will be described later.

[0087] The light collected by the first optical element 802R is incident on the first light modulation device 804R. The first light modulation device 804R modulates the incident light in accordance with image information. The projection device 808 then enlarges the image formed by the first light modulation device 804R and projects it onto a screen 810.

[0088] The light emitted from green light source 100G is incident on second optical element 802G. The light emitted from green light source 100G is collected by second optical element 802G.

[0089] The light collected by the second optical element 802G is incident on the second light modulation device 804G. The second light modulation device 804G modulates the incident light in accordance with image information. The projection device 808 then enlarges the image formed by the second light modulation device 804G and projects it onto the screen 810.

[0090] The light emitted from blue light source 100B is incident on third optical element 802B. The light emitted from blue light source 100B is collected by third optical element 802B.

[0091] The light collected by the third optical element 802B enters the third light modulation device 804B. The third light modulation device 804B modulates the incident light in accordance with image information. The projection device 808 then enlarges the image formed by the third light modulation device 804B and projects it onto the screen 810.

[0092] The projector 800 may also have a cross dichroic prism 806 that combines the light emitted from the first light modulation device 804R, the second light modulation device 804G, and the third light modulation device 804B and guides the combined light to the projection device 808.

[0093] The three colored lights modulated by the first light modulation device 804R, the second light modulation device 804G, and the third light modulation device 804B enter a cross dichroic prism 806. The cross dichroic prism 806 is formed by bonding four right-angle prisms together, and a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are disposed on its inner surface. These dielectric multilayer films combine the three colored lights to form light that represents a color image. The combined light is then projected onto a screen 810 by a projection device 808, The enlarged image is displayed.

[0094] Note that red light source 100R, green light source 100G, and blue light source 100B may directly form an image without using first light modulation device 804R, second light modulation device 804G, and third light modulation device 804B, by controlling light emitting device 100 as pixels of the image in accordance with image information. Then, projection device 808 may enlarge and project the image formed by red light source 100R, green light source 100G, and blue light source 100B onto screen 810.

[0095] In the above example, a transmissive liquid crystal light valve is used as the light modulation device, but a light valve other than a liquid crystal light valve or a reflective light valve may also be used. Examples of such light valves include a reflective liquid crystal light valve and a digital micromirror device. The configuration of the projection device can be changed as appropriate depending on the type of light valve used.

[0096] The light source can also be applied to a light source device of a scanning type image display device having a scanning means which is an image forming device that displays an image of a desired size on a display surface by scanning light from the light source on a screen.

[0097] 5. Fifth embodiment Next, a display according to a fifth embodiment will be described with reference to the drawings. Fig. 16 is a plan view schematically showing a display 900 according to the fifth embodiment. Fig. 17 is a cross-sectional view schematically showing the display 900 according to the fifth embodiment. For convenience, Fig. 16 illustrates an X-axis and a Y-axis as two axes that are orthogonal to each other.

[0098] The display 900 includes, for example, a light emitting device 100 as a light source.

[0099] The display 900 is a display device that displays images. Images include images that display only text information. The display 900 is a self-luminous display. As shown in FIGS. 16 and 17 , the display 900 has a circuit board 910, a lens array 920, and a heat sink 930.

[0100] A drive circuit for driving the light emitting device 100 is mounted on the circuit board 910. The drive circuit is, for example, a circuit including a CMOS (Complementary Metal Oxide Semiconductor). The drive circuit drives the light emitting device 100 based on, for example, input image information. Although not shown, a light-transmitting substrate for protecting the circuit board 910 is disposed on the circuit board 910.

[0101] The circuit board 910 has a display area 912 , a data line driving circuit 914 , a scanning line driving circuit 916 , and a control circuit 918 .

[0102] The display area 912 is made up of a plurality of pixels P. In the illustrated example, the pixels P are arranged along the X-axis and Y-axis.

[0103] Although not shown, a plurality of scanning lines and a plurality of data lines are provided on the circuit board 910. For example, the scanning lines extend along the X axis, and the data lines extend along the Y axis. The scanning lines are connected to a scanning line driving circuit 916. The data lines are connected to a data line driving circuit 914. Pixels P are provided at intersections of the scanning lines and the data lines.

[0104] One pixel P includes, for example, one light emitting device 100, one lens 922, and a The pixel circuit includes a switching transistor that functions as a switch for the pixel P, the gate of the switching transistor being connected to a scan line, and either the source or the drain being connected to a data line.

[0105] The data line driving circuit 914 and the scanning line driving circuit 916 are circuits that control the driving of the light emitting devices 100 that constitute the pixels P. The control circuit 918 controls the display of images.

[0106] Image data is supplied from a higher-level circuit to the control circuit 918. The control circuit 918 supplies various signals based on the image data to the data line driving circuit 914 and the scanning line driving circuit 916.

[0107] When the scanning line driving circuit 916 activates a scanning signal to select a scanning line, the switching transistor of the selected pixel P is turned on. At this time, the data line driving circuit 914 supplies a data signal from the data line to the selected pixel P, causing the light emitting device 100 of the selected pixel P to emit light in accordance with the data signal.

[0108] The lens array 920 has a plurality of lenses 922. For example, one lens 922 is provided for each light emitting device 100. Light emitted from the light emitting device 100 is incident on one lens 922.

[0109] The heat sink 930 is in contact with the circuit board 910. The material of the heat sink 930 is, for example, a metal such as copper or aluminum. The heat sink 930 dissipates heat generated by the light emitting device 100.

[0110] The light-emitting devices according to the above-described embodiments can be used for purposes other than projectors and displays. Examples of uses other than projectors and displays include indoor and outdoor lighting, laser printers, scanners, in-vehicle lights, light-using sensing devices, communication devices, and other light sources. Furthermore, the light-emitting devices according to the above-described embodiments can be used as display devices for head-mounted displays.

[0111] The above-described embodiment and modifications are merely examples, and the present invention is not limited to these. For example, the embodiments and modifications can be combined as appropriate.

[0112] The present invention includes configurations that are substantially the same as the configurations described in the embodiments, for example, configurations with the same functions, methods, and results, or configurations with the same purpose and effects. The present invention also includes configurations that replace non-essential parts of the configurations described in the embodiments. The present invention also includes configurations that achieve the same effects or purposes as the configurations described in the embodiments. The present invention also includes configurations that add publicly known technology to the configurations described in the embodiments.

[0113] The following can be derived from the above-described embodiment and modifications.

[0114] One aspect of the light emitting device is A substrate; a plurality of first columnar portions provided on the substrate; a plurality of second columnar sections provided on the substrate and surrounding the plurality of first columnar sections when viewed in a normal direction of the substrate; a first semiconductor layer provided on the opposite side of the plurality of first columnar sections from the substrate and connected to the plurality of first columnar sections; an insulating layer covering the first semiconductor layer and the plurality of second columnar sections; a wiring provided on the insulating layer opposite the substrate and electrically connected to the first semiconductor layer; and Each of the plurality of first columnar portions and each of the plurality of second columnar portions are an n-type second semiconductor layer; a p-type third semiconductor layer; a u-type fourth semiconductor layer provided between the second semiconductor layer and the third semiconductor layer; and the fourth semiconductor layer in each of the plurality of first columnar sections emits light when a current is injected into it; no current is injected into the fourth semiconductor layer in each of the plurality of second columnar sections, When viewed from the normal direction, the wiring overlaps with at least one of the second columnar portions.

[0115] This light emitting device can reduce the possibility of leakage current flowing between the first columnar section and the wiring.

[0116] In one embodiment of the light emitting device, a fifth semiconductor layer provided on the opposite side of the second columnar sections from the substrate and connected to the second columnar sections, The fifth semiconductor layer may be electrically isolated from the first semiconductor layer.

[0117] According to this light emitting device, the flatness of the upper surface of the insulating layer can be improved.

[0118] In one embodiment of the light emitting device, the thickness of the fifth semiconductor layer is the same as the thickness of the first semiconductor layer; The material of the fifth semiconductor layer may be the same as the material of the first semiconductor layer.

[0119] According to this light emitting device, for example, the first semiconductor layer and the fifth semiconductor layer can be formed in the same process.

[0120] In one embodiment of the light emitting device, an electrode provided on the side of the first semiconductor layer opposite to the substrate; The wiring may be connected to the electrode through a contact hole provided in the insulating layer.

[0121] This light emitting device can prevent the electrode material from entering between adjacent first columnar sections.

[0122] In one embodiment of the light emitting device, When viewed from the normal direction, the electrode may completely overlap the first semiconductor layer.

[0123] According to this light emitting device, the first semiconductor layer and the electrodes can be etched together in the same process.

[0124] In one embodiment of the light emitting device, When viewed from the normal direction, the electrode may be provided inside the outer edge of the first semiconductor layer and may not overlap the outer edge.

[0125] This light emitting device allows for a margin of accuracy in the manufacturing process.

[0126] One aspect of the projector is The light emitting device has one aspect.

[0127] One embodiment of the display is The light emitting device has one aspect. [Explanation of symbols]

[0128] 10...substrate, 20...laminated body, 22...buffer layer, 24...first region, 26...second region, 30...columnar portion, 30a, 30a1...first columnar portion, 30b, 30b1, 30b2...second columnar portion, 32...n-type semiconductor layer, 34...u-type semiconductor layer, 36...p-type semiconductor layer, 40...first semiconductor layer, 42...outer edge, 50...first electrode, 52...second electrode, 60...insulating layer, 62...first contact hole, 64...second contact hole, 70...first wiring, 72...second wiring, 74...first layer, 76...second layer, 80...pad, 90...fifth semiconductor layer, 100...light-emitting device, 102...light-emitting element, 200, 300...light-emitting device, 800...projector, 802R...first optical element, 802G...second optical element, 802B... Third optical element, 804R...first optical modulation device, 804G...second optical modulation device, 804B...third optical modulation device, 806...cross dichroic prism, 808...projection device, 810...screen, 900...display, 910...circuit board, 912...display area, 914...data line driving circuit, 916...scanning line driving circuit, 918...control circuit, 920...lens array, 922...lens, 930...heat sink, 1000...light-emitting device, 1030...columnar portion, 1031...etching residue, 1040...first semiconductor layer, 1052...second electrode, 1060...insulating layer, 1062...step portion, 1072...second wiring, 2000...light-emitting device, 2030b...second columnar portion, 2060...insulating layer, 2062...recess

Claims

1. A substrate; a plurality of first columnar portions provided on the substrate; a plurality of second columnar sections provided on the substrate and surrounding the plurality of first columnar sections when viewed in a normal direction of the substrate; a first semiconductor layer provided on the opposite side of the plurality of first columnar sections from the substrate and connected to the plurality of first columnar sections; an insulating layer covering the first semiconductor layer and the plurality of second columnar sections; a wiring provided on the insulating layer opposite to the substrate and electrically connected to the first semiconductor layer; and the plurality of second columnar portions are provided contiguously with the plurality of first columnar portions, Each of the plurality of first columnar portions and each of the plurality of second columnar portions are an n-type second semiconductor layer; a p-type third semiconductor layer; a u-type fourth semiconductor layer provided between the second semiconductor layer and the third semiconductor layer; and the fourth semiconductor layer in each of the plurality of first columnar sections emits light when a current is injected into it; no current is injected into the fourth semiconductor layer in each of the second columnar sections, When viewed from the normal direction, the wiring overlaps with at least one of the plurality of second columnar portions, a distance between an outermost first columnar portion of the plurality of first columnar portions and a second columnar portion of the plurality of second columnar portions adjacent to the outermost first columnar portion is the same as a distance between adjacent second columnar portions of the plurality of second columnar portions, a fifth semiconductor layer provided on the opposite side of the second columnar sections from the substrate and connected to the second columnar sections; The fifth semiconductor layer is electrically isolated from the first semiconductor layer.

2. In claim 1, the thickness of the fifth semiconductor layer is the same as the thickness of the first semiconductor layer; A light emitting device, wherein the material of the fifth semiconductor layer is the same as the material of the first semiconductor layer.

3. In claim 1 or 2, an electrode provided on the first semiconductor layer on the opposite side to the substrate; The wiring is connected to the electrode via a contact hole provided in the insulating layer.

4. In claim 3, The light-emitting device, wherein the electrode completely overlaps the first semiconductor layer when viewed from the normal direction.

5. In claim 3, When viewed from the normal direction, the electrode is provided inside the outer edge of the first semiconductor layer and does not overlap the outer edge.

6. A projector comprising the light emitting device according to claim 1 .

7. A display comprising a light-emitting device according to any one of claims 1 to 5.

Images