Light emitting device and method for producing light emitting device

Abstract

A light emitting device according to one embodiment of the present disclosure is provided with: a plurality of light emitting elements that are two-dimensionally arranged; and a plurality of wavelength conversion layers that are disposed one by one on the light emission side of the plurality of light emitting elements so as to respectively face the light emitting elements. Each light emitting element has a multilayer body which sequentially includes a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer in this order toward the wavelength conversion layer side. In each light emitting element, the second conductivity type semiconductor layer is provided with a recess or an incision, and the entirety or a part of the corresponding wavelength conversion layer is housed in the recess or the incision.

Description

Light emitting device and method for manufacturing the same

[0001] The present disclosure relates to a light emitting device and a method for manufacturing the same.

[0002] Various micro light-emitting elements have been proposed so far (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2020-86461

[0004] However, in light emitting devices including micro light emitting elements, there is a demand for improving the light extraction efficiency. It is desirable to provide a light emitting device capable of improving the light extraction efficiency and a method for manufacturing the same.

[0005] A light emitting device according to an embodiment of the present disclosure includes a plurality of light emitting elements arranged two-dimensionally, and a plurality of wavelength conversion layers stacked one on each of the light emitting elements on the light emission side of the light emitting elements and facing the light emitting elements. Each light emitting element has a stacked body including, in order toward the wavelength conversion layer, a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer. In each light emitting element, the second conductivity type semiconductor layer has a recess or cutout portion, and the recess or cutout portion accommodates all or part of the corresponding wavelength conversion layer.

[0006] In the light-emitting device according to an embodiment of the present disclosure, the second conductivity-type semiconductor layer of each light-emitting element has a recess or cutout, and the recess or cutout accommodates all or part of the corresponding wavelength conversion layer. For example, by providing an isolation structure between the light-emitting elements that separates the light-emitting elements, the isolation structure can also serve as an isolation structure that separates the wavelength conversion layers. Furthermore, by providing the isolation structure between the light-emitting elements, light emitted from the light-emitting elements can be incident on the wavelength conversion layer without being blocked by the isolation structure.

[0007] A method for manufacturing a light emitting device according to an embodiment of the present disclosure includes the following three steps: (A) forming a plurality of light emitting elements, each including a second conductivity type semiconductor layer, an active layer, and a first conductivity type semiconductor layer in this order from the semiconductor substrate side, on a semiconductor substrate, and then forming a wiring layer electrically connected to each of the light emitting elements to form a light emitting substrate; (B) bonding a support substrate to the wiring layer of the light emitting substrate, and then removing the semiconductor substrate; and (C) etching the second conductivity type semiconductor layer of each light emitting element to form recesses or cutouts in the second conductivity type semiconductor layer, and then forming a wavelength conversion layer to fill each recess or cutout.

[0008] In a method for manufacturing a light-emitting device according to an embodiment of the present disclosure, the second conductivity type semiconductor layer of each light-emitting element is etched to form recesses or cutouts in the second conductivity type semiconductor layer, and then a wavelength conversion layer is formed to fill each recess or cutout. For example, by providing an isolation structure between light-emitting elements that separates the light-emitting elements, this isolation structure can also serve as an isolation structure separating the wavelength conversion layers. Furthermore, by providing this isolation structure between the light-emitting elements, light emitted from the light-emitting elements can be incident on the wavelength conversion layer without being blocked by the isolation structure.

[0009] FIG. 1 is a diagram illustrating an example cross-sectional configuration of a light-emitting device according to an embodiment of the present disclosure. FIG. 2 is a diagram illustrating an example cross-sectional configuration of the light-emitting element of FIG. 1 and its vicinity. FIG. 3 is a diagram illustrating an example cross-sectional configuration taken along line A-A of FIG. 2. FIG. 4 is a diagram illustrating an example cross-sectional configuration taken along line B-B of FIG. 2. FIG. 3 is a diagram illustrating a modified cross-sectional configuration taken along line A-A of FIG. 2. FIG. 4 is a diagram illustrating a modified cross-sectional configuration taken along line B-B of FIG. 2. FIG. 7 is a diagram illustrating a modified cross-sectional configuration of FIG. 4. FIG. 8 is a diagram illustrating a modified cross-sectional configuration of FIG. 6. FIG. 9A is a diagram illustrating an example cross-sectional configuration for explaining an example of a manufacturing process of the light-emitting device of FIG. 1. FIG. 9B is a diagram illustrating an example cross-sectional configuration at a step subsequent to FIG. 9A. FIG. 9C is a diagram illustrating an example cross-sectional configuration at a step subsequent to FIG. 9B. FIG. 9D is a diagram illustrating an example cross-sectional configuration at a step subsequent to FIG. 9C. FIG. 9E is a diagram illustrating an example cross-sectional configuration at a step subsequent to FIG. 9D. FIG. 9F is a diagram illustrating an example cross-sectional configuration at a step subsequent to FIG. 9E. FIG. 9G is a diagram illustrating an example of a cross-sectional configuration at a step subsequent to FIG. 9F. FIG. 9H is a diagram illustrating an example of a cross-sectional configuration at a step subsequent to FIG. 9G. FIG. 9I is a diagram illustrating an example of a cross-sectional configuration at a step subsequent to FIG. 9H. FIG. 9J is a diagram illustrating an example of a cross-sectional configuration at a step subsequent to FIG. 9I. FIG. 9K is a diagram illustrating an example of a cross-sectional configuration at a step subsequent to FIG. 9J. FIG. 10 is a diagram illustrating a modified cross-sectional configuration of the light-emitting device of FIG. 1. FIG. 11 is a diagram illustrating an example of a cross-sectional configuration of the light-emitting element of FIG. 10 and its vicinity. FIG. 12 is a diagram illustrating a modified cross-sectional configuration of FIG. 11. FIG. 13 is a diagram illustrating a modified cross-sectional configuration of FIG. 12. FIG. 14 is a diagram illustrating a modified cross-sectional configuration of FIG. 13. FIG. 15 is a diagram illustrating a modified cross-sectional configuration of FIG. 2. FIG. 16 is a diagram illustrating a modified cross-sectional configuration of FIG. 11. FIG. 17 is a diagram illustrating a modified cross-sectional configuration of FIG. 2. FIG. 18 is a diagram illustrating a modified cross-sectional configuration of FIG. 2. FIG. 19 is a diagram illustrating a modified cross-sectional configuration of FIG. 2. Fig. 20 is a diagram showing a modified example of the cross-sectional configuration of Fig. 2. Fig. 21 is a diagram showing a modified example of the cross-sectional configuration of Fig. 2. Fig. 22 is a diagram showing a modified example of the cross-sectional configuration of Fig. 2. Fig. 23 is a diagram showing a modified example of the cross-sectional configuration of Fig. 10. Fig. 24 is a diagram showing an example of the cross-sectional configuration of the light-emitting element of Fig. 23 and its vicinity. Fig. 25 is a diagram showing a modified example of the cross-sectional configuration of Fig. 24.FIG. 26 is a diagram showing a modified example of the cross-sectional configuration of FIG. 2. FIG. 27 is a diagram showing a modified example of the cross-sectional configuration of FIG. 2. FIG. 28 is a diagram showing a modified example of the cross-sectional configuration of FIG. 2. FIG. 29 is a diagram showing a modified example of the cross-sectional configuration of FIG. 2. FIG. 30 is a diagram showing a modified example of the cross-sectional configuration of FIG. 2. FIG. 31 is a diagram showing a modified example of the cross-sectional configuration of FIG. 2. FIG. 32 is a diagram showing a modified example of the cross-sectional configuration of FIG. 10. FIG. 33 is a diagram showing an example of the cross-sectional configuration of the light-emitting element of FIG. 32 and its vicinity. FIG. 34 is a diagram showing an example of the cross-sectional configuration taken along line A-A of FIG. 33. FIG. 35 is a diagram showing an example of the cross-sectional configuration taken along line B-B of FIG. 33. FIG. 36 is a diagram showing a modified example of the cross-sectional configuration taken along line A-A of FIG. 23. FIG. 37 is a diagram showing a modified example of the cross-sectional configuration taken along line B-B of FIG. 33. FIG. 38 is a diagram showing a modified example of the cross-sectional configuration of FIG. 35. FIG. 39 is a diagram showing a modified example of the cross-sectional configuration of FIG. 37. Fig. 40A is a diagram showing an example of a cross-sectional configuration for explaining an example of a manufacturing process for the light-emitting device of Fig. 32. Fig. 40B is a diagram showing an example of a cross-sectional configuration in a process subsequent to Fig. 40A. Fig. 40C is a diagram showing an example of a cross-sectional configuration in a process subsequent to Fig. 40B. Fig. 41 is a diagram showing a modified example of the cross-sectional configuration of Fig. 32. Fig. 42 is a diagram showing an example of a horizontal cross-sectional configuration of the light-emitting device of Fig. 41. Fig. 43 is a diagram showing an example of a cross-sectional configuration of a dummy pixel of the light-emitting device of Fig. 41. Fig. 44 is a diagram showing a modified example of the cross-sectional configuration of Fig. 2. Fig. 45 is a diagram showing a modified example of the cross-sectional configuration of Fig. 33.

[0010] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.

[0011] Furthermore, in this specification and drawings, multiple components having substantially the same or similar functional configurations may be distinguished by adding different numbers after the same reference numeral. However, if there is no need to particularly distinguish between multiple components having substantially the same or similar functional configurations, only the same reference numeral will be used. Furthermore, similar components in different embodiments may be distinguished by adding different letters after the same reference numeral. However, if there is no need to particularly distinguish between similar components, only the same reference numeral will be used.

[0012] In addition, the drawings referred to in the following description are intended to facilitate the description and understanding of one embodiment of the present disclosure, and for clarity, the shapes, dimensions, ratios, etc. shown in the drawings may differ from the actual shapes, dimensions, ratios, etc. Furthermore, the light-emitting devices shown in the drawings may be appropriately modified in design taking into account the following description and known technologies. In addition, in descriptions using cross-sectional views of the light-emitting device, the vertical direction of the stacked structure of the light-emitting device corresponds to the relative direction when the incident surface on which light is incident on the light-emitting device is set as the top, and may differ from the vertical direction according to the actual gravitational acceleration.

[0013] Furthermore, in the following explanation, expressions relating to size and shape do not only mean values ​​identical to mathematically defined numerical values ​​or geometrically defined shapes, but also include shapes that have industrially acceptable differences in the manufacturing process of the light-emitting device or shapes similar to those shapes.

[0014] Furthermore, in the following description of the circuit configuration, unless otherwise specified, "connection" means electrical connection between multiple elements. In addition, in the following description, "connection" includes not only direct and electrical connection between multiple elements, but also indirect and electrical connection via other elements.

[0015] The description will be given in the following order: 1. Embodiment (Light-emitting device) 1-1. Configuration of light-emitting device (FIGS. 1 to 8) 1-2. Manufacturing method of light-emitting device (FIGS. 9A to 9K) 1-3. Actions and effects 2. Modifications (Light-emitting device) 2-1. Modification A (FIGS. 10 and 11) 2-2. Modification B (FIG. 12) 2-3. Modification C (FIGS. 13 and 14) 2-4. Modification D (FIGS. 15 and 16) 2-5. Modification E (FIGS. 17 to 19) 2-6. Modification F (FIG. 20) 2-7. Modification G (FIG. 21) 2-8. Modification H (FIG. 22) 2-9. Modification I (FIGS. 23 to 25) 2-10. Modification J (FIG. 26) 2-11. Modification K (FIG. 27) 2-12. Modification L (Figs. 28 to 30) 2-13. Modification M (Fig. 31) 2-14. Modification N (Figs. 32 to 40C) 2-15. Modification O (Figs. 41 to 43) 2-16. Modification P (Figs. 44 and 45)

[0016] <1. Embodiment> [Configuration] A light emitting device 1 according to an embodiment of the present disclosure will be described. FIG. 1 illustrates an example cross-sectional configuration of the light emitting device 1 according to an embodiment of the present disclosure. FIG. 2 illustrates an enlarged cross-sectional configuration of a portion of the light emitting device 1 shown in FIG. 1 (a light emitting element 21 described below and its vicinity). FIGS. 3 and 5 illustrate an example cross-sectional configuration taken along line A-A in FIG. 2. In FIG. 3, an insulating layer 22, a reflective layer 23, and an insulating layer 25 described below are omitted. FIGS. 4 and 6 illustrate an example cross-sectional configuration taken along line B-B in FIG. 2.

[0017] (1-1. Configuration of the Light-Emitting Device) The light-emitting device 1 includes a display section 100A in which a plurality of pixels (for example, red pixels Pr, green pixels Pg, and blue pixels Pb) are arranged in a two-dimensional array, and a frame section 100B provided around the display section 100A. The red pixels Pr, green pixels Pg, and blue pixels Pb form a color pixel Pcolor (FIG. 3). Hereinafter, the red pixels Pr, green pixels Pg, and blue pixels Pb will be collectively referred to as pixel P as appropriate.

[0018] The light-emitting device 1 has, for example, a light-emitting section 10 stacked on a drive substrate 40. The outermost surface of the light-emitting section 10 is a light-emitting surface S1. A plurality of pixels P (Pr, Pg, Pb) are arranged in a two-dimensional array in a planar view. When each pixel P has a rectangular shape in a planar view, the plurality of pixels P may be arranged in a matrix, for example, as shown in FIGS. 3 and 4. When each pixel P has a hexagonal shape in a planar view, the plurality of pixels P may be arranged in a honeycomb pattern, for example, as shown in FIGS. 5 and 6. In this specification, the term "planar view" refers to a plane having a normal to the stacking direction of the light-emitting device 1, viewed from the stacking direction of the light-emitting device 1.

[0019] First, the light emitting unit 10 will be described.

[0020] The light-emitting section 10 has a laminated structure in which a light-emitting layer 20 having a light-emitting surface S1 and a wiring layer 30 arranged on the surface of the light-emitting layer 20 opposite the light-emitting surface S1 are stacked together.

[0021] The light-emitting layer 20 has a plurality of light-emitting elements 21 arranged two-dimensionally. The light-emitting element 21 corresponds to a specific example of a "light-emitting element" according to an embodiment of the present disclosure. The plurality of light-emitting elements 21 are provided for each pixel P. The light-emitting element 21 is a solid-state light-emitting element that emits light in a predetermined wavelength band toward the light-emitting surface S1, such as an LED (light-emitting diode). The light-emitting element 21 refers to an element cut from a wafer used for crystal growth, and is not a packaged type covered with molded resin or the like. The light-emitting element 21 has a size of, for example, 5 μm to 100 μm, and is a so-called micro-LED. The plurality of light-emitting elements 21 are provided separately from each other. Note that the plurality of light-emitting elements 21 may be provided in a common semiconductor layer (e.g., a part of the n-type compound semiconductor layer 111 described below).

[0022] 2 , the light-emitting element 21 has a stacked body including, in order toward the light-emitting surface S1 side (the wavelength conversion layer 26 side described later), an electrode layer 114, a p-type compound semiconductor layer 113, an active layer 112, and an n-type compound semiconductor layer 111. The p-type compound semiconductor layer 113 corresponds to a specific example of a "first conductivity type semiconductor layer" according to an embodiment of the present disclosure. The active layer 112 corresponds to a specific example of an "active layer" according to an embodiment of the present disclosure. The n-type compound semiconductor layer 111 corresponds to a specific example of a "second conductivity type semiconductor layer" according to an embodiment of the present disclosure.

[0023] The light-emitting element 21 is a mesa-shaped light-emitting element having a p-type compound semiconductor layer 113 side (specifically, the electrode layer 114) at its top. Hereinafter, the mesa-shaped portion of the light-emitting element 21 will be referred to as the mesa portion 21B. The light-emitting element 21 (mesa portion 21B) is configured to emit emitted light in the upward direction in the drawing (toward the wavelength conversion layer 26 described below) by light reflection by the adjacent reflective layer 23. For example, as shown in FIGS. 1 and 2 , the top of the mesa portion 21B faces downward in the drawing (i.e., toward the drive substrate 40). For example, the mesa portion 21B has a forward tapered side surface relative to the light-emitting surface S1. The angle of the side surface of the mesa portion 21B is, for example, 45° or more and less than 90°. Note that the side surface of the mesa portion 21B may be perpendicular to the light-emitting surface S1.

[0024] The light-emitting element 21 (n-type compound semiconductor layer 111, active layer 112, and p-type compound semiconductor layer 113) is, for example, a GaN-based compound semiconductor. Examples of GaN-based compound semiconductors include GaN, AlGaN, InGaN, and AlInGaN. The active layer 112 is capable of emitting light in the blue region with an emission wavelength of 430 nm or more and 500 nm or less. The active layer 112 may be capable of emitting light in the ultraviolet region with an emission wavelength of 350 nm or more and 430 nm or less. The active layer 112 has, for example, a bulk structure, a single quantum well structure, or a quantum well structure.

[0025] The light-emitting layer 20 has an electrode layer 114 and plugs 21a and 21b for each pixel (Pr, Pg, Pb). The electrode layer 114 is disposed on the top of the mesa portion 21B. The electrode layer 114 is in contact with the p-type compound semiconductor layer 113 and is electrically connected to the p-type compound semiconductor layer 113. The plug 21a is a contact plug disposed opposite the electrode layer 114. One end of the plug 21a is in contact with the electrode layer 114. The plug 21a is electrically connected to the electrode layer 114 and is electrically connected to the p-type compound semiconductor layer 113 via the electrode layer 114. The other end of the plug 21a is in contact with an extraction electrode 33 (described below). The plug 21a is electrically connected to the extraction electrode 33 and is electrically connected to the drive substrate 40 via the extraction electrode 33. The electrode layer 114 is a transparent conductive layer that is transparent to the light emitted from the light-emitting element 21.

[0026] A step is provided on the side surface of the mesa portion 21B, exposing a flat surface 21D of the p-type compound semiconductor layer 113. The plug 21b is a contact plug arranged at a position facing the flat surface 21D. One end of the plug 21b contacts the flat surface 21D (n-type compound semiconductor layer 111). The plug 21b is electrically connected to the flat surface 21D (n-type compound semiconductor layer 111). The other end of the plug 21b contacts an extraction electrode 35, which will be described later. The plug 21b is electrically connected to the extraction electrode 35, and is electrically connected to the drive substrate 40 via the extraction electrode 35.

[0027] The electrode layer 114 is made of, for example, an indium-based transparent conductive material, a tin-based transparent conductive material, or a zinc-based transparent conductive material. Examples of the indium-based transparent conductive material include indium-tin oxide (ITO, Indium Tin Oxide, Sn-doped In ２ O ３ , including crystalline ITO and amorphous ITO), indium zinc oxide (IZO), indium gallium oxide (IGO), indium-doped gallium zinc oxide (IGZO, In-GaZnO ４ ), IFO (F-doped In ２ O３ ), ITiO (Ti-doped In ２ O ３ ), InSn, or InSnZnO. Examples of tin-based transparent conductive materials include tin oxide (SnO ２ ), ATO (Sb-doped SnO ２ ), FTO (F-doped SnO ２ ) and the like. Examples of zinc-based transparent conductive materials include zinc oxide (including ZnO, Al-doped ZnO (AZO), and B-doped ZnO), gallium-doped zinc oxide (GZO), and AlMgZnO (aluminum oxide and magnesium oxide-doped zinc oxide). The electrode layer 114 may be, for example, a single layer made of the above-mentioned material, or may be a laminated film selected from the above-mentioned materials. The electrode layer 114 may be, for example, made of a metal material.

[0028] The plugs 21a and 21b are embedded in an insulating layer 22 along with the light-emitting element 21. The plugs 21a and 21b are formed, for example, by columnar metal members formed to fill trenches formed in the insulating layer 22. The insulating layer 22 is formed, for example, by silicon oxide (SiO) or silicon nitride (SiN). The plugs 21a and 21b are formed, for example, by a metal or metal compound containing Ti, W, Al, Ni, Ta, Cu, Ag, or Au as a main component. The plugs 21a and 21b are formed, for example, by chemical vapor deposition (CVD) or atomic layer deposition (ALD). The plugs 21a and 21b may be, for example, a single layer formed of the above-mentioned materials or a stacked film formed of materials selected from the above-mentioned materials.

[0029] The light-emitting layer 20 further includes a reflective layer 23 at a location facing the plurality of light-emitting elements 21. The reflective layer 23 is continuously formed from a portion of the top of the mesa portion 21B facing a portion not in contact with the plug 21a to a portion facing a side surface of the mesa portion 21B. The reflective layer 23 is continuously formed from a portion of the top of the mesa portion 21B facing a portion not in contact with the plug 21a to a portion of the side surface of the mesa portion 21B facing a side surface of a wavelength conversion layer 26 (described later). The reflective layer 23 is formed to cover the mesa portion 21B from a portion of the top of the mesa portion 21B not in contact with the plug 21a to the side surface of the mesa portion 21B. The reflective layer 23 is, for example, an electrically floating layer that is not in contact with the light-emitting element 21 (the n-type compound semiconductor layer 111, the active layer 112, the p-type compound semiconductor layer 113, and the electrode layer 114) and the plugs 21a and 21b.

[0030] The reflective layer 23 is made of a material having a reflectance higher than that of the electrode layer 114 (reflectance for the wavelength of light emitted from the light emitting element 21). The reflective layer 23 is made of a metal or metal compound containing, for example, Ag, Al, Ti, W, Ni, Ta, Cu, or Au as a main component. An insulating layer 24 is provided between the reflective layer 23 and the electrode layer 114. The insulating layer 24 is a layer for electrically isolating the reflective layer 23 and the electrode layer 114 from each other. The insulating layer 24 is made of, for example, silicon oxide (SiO), silicon nitride (SiN), or the like.

[0031] The light-emitting layer 20 further includes a plurality of wavelength conversion layers 26R, 26G, and 26B arranged two-dimensionally. Hereinafter, the wavelength conversion layers 26R, 26G, and 26B will be collectively referred to as wavelength conversion layer 26, as appropriate. The wavelength conversion layer 26 corresponds to a specific example of a "wavelength conversion layer" according to an embodiment of the present disclosure. Each of the plurality of wavelength conversion layers 26 is provided for each pixel P. A pixel P is formed by the light-emitting elements 21 and the wavelength conversion layers 26 facing each other. The plurality of wavelength conversion layers 26 are stacked one by one on the light-emitting sides of the plurality of light-emitting elements 21, facing each light-emitting element 21. In each light-emitting element 21, a recess 21A is provided in the n-type compound semiconductor layer 111. The recess 21A is provided at the bottom of the mesa portion 21B. The recess 21A accommodates all or part of the corresponding wavelength conversion layer 26.

[0032] The wavelength conversion layers 26 are provided one for each pixel P, one at a position facing each light-emitting element 21. A region including the wavelength conversion layer 26R and the light-emitting element 21 that overlap each other in a planar view is a red pixel Pr. Similarly, a region including the wavelength conversion layer 26G and the light-emitting element 21 that overlap each other in a planar view is a green pixel Pg, and a region including the wavelength conversion layer 26B and the light-emitting element 21 that overlap each other in a planar view is a blue pixel Pb.

[0033] The plurality of wavelength conversion layers 26 are capable of converting light emitted from the plurality of light-emitting elements 21 into desired wavelengths (e.g., red (R), green (G), blue (B)) and emitting the light. Specifically, the red pixel Pr is provided with a wavelength conversion layer 26R that converts light emitted from the light-emitting elements 21 into light of a red band (red light), the green pixel Pg is provided with a wavelength conversion layer 26G that converts light emitted from the light-emitting elements 21 into light of a green band (green light), and the blue pixel Pb is provided with a wavelength conversion layer 26B that converts light emitted from the light-emitting elements 21 into light of a blue band (blue light).

[0034] Each wavelength conversion layer 26 can be formed using quantum dots corresponding to each color. Specifically, when red light is to be obtained, the quantum dots can be selected from, for example, InP, GaInP, InAsP, CdSe, CdZnSe, CdTeSe, or CdTe. When green light is to be obtained, the quantum dots can be selected from, for example, InP, GaInP, ZnSeTe, ZnTe, CdSe, CdZnSe, CdS, or CdSeS. When blue light is to be obtained, the quantum dots can be selected from, for example, ZnSe, ZnTe, ZnSeTe, CdSe, CdZnSe, CdS, CdZnS, or CdSeS. Note that when blue light is emitted from the light-emitting element 21 as described above, the wavelength conversion layer 26B may be formed from a light-transmitting resin layer.

[0035] The reflective layer 23 is a sheet-like layer provided across each pixel P. Parts of the reflective layer 23 are provided at the boundaries between two adjacent pixels P, specifically, at the boundary between the red pixel Pr and the green pixel Pg, the boundary between the green pixel Pg and the blue pixel Pb, and the boundary between the blue pixel Pb and the red pixel Pr. That is, parts of the reflective layer 23 are provided in the region between two adjacent light-emitting elements 21 and in the region between two adjacent wavelength conversion layers 26. Therefore, the reflective layer 23 has an isolation structure 23A at the boundary between two adjacent pixels P that physically and optically isolates each pixel P.

[0036] The separation structure 23A can suppress color mixing due to light leakage between pixels P. The separation structure 23A has, for example, a lattice structure as shown in FIG. 4 . The separation structure 23A may have, for example, a honeycomb structure as shown in FIG. 6 . The end of the separation structure 23A on the light-emitting surface S1 side (hereinafter simply referred to as the "end of the separation structure 23A") is in contact with, for example, the insulating layer 25. The separation structure 23A narrows toward the light-emitting surface S1 and has a light-reflecting surface that is inversely tapered with respect to the light-emitting surface S1. The separation structure 23A and the insulating layers 24 and 25, in their peripheral portions, serve as margins for printing multiple wavelength conversion layers 26 for each color during the manufacturing process. The separation structure 23A may have, for example, a dot-like structure in which the lattice structure is finely divided, as shown in FIG. 7 . Furthermore, the separation structure 23A may be, for example, a dot-shaped structure in which a honeycomb structure is finely divided, as shown in FIG.

[0037] The light-emitting layer 20 further includes an insulating layer 25 between the inner surface of the recess 21A and the wavelength conversion layer 26, the insulating layer 25 being in contact with the inner surface of the recess 21A and the wavelength conversion layer 26. The insulating layer 25 is a layer for protecting the surface of the n-type compound semiconductor layer 111 (the inner surface of the recess 21A) during the manufacturing process. The insulating layer 25 is formed of, for example, SiO, SiN, SiON, TiO, AlO, TaO, SiOC, or SiOCN.

[0038] The light-emitting layer 20 further includes protective layers 27 and 29 and a light-shielding layer 28 on the light-emitting surface S1 side. The protective layers 27 and 29 are intended to protect the surface of the light-emitting device 1 and are formed of, for example, silicon oxide (SiO) or silicon nitride (SiN). The protective layer 27 is in contact with, for example, the surfaces of the wavelength conversion layer 26 and the insulating layer 25. The protective layer 29 is provided, for example, to cover the light-shielding layer 28, and the surface of the protective layer 29 constitutes the light-emitting surface S1 of the light-emitting layer 20. A wavelength selection layer may be provided within the protective layer 29, spanning the red pixel Pr and the green pixel Pg. The wavelength selection layer selectively reflects, for example, light in the blue wavelength band (blue light), thereby improving the color purity of the red light and green light extracted from the red pixel Pr and the green pixel Pg, respectively.

[0039] The light-shielding layer 28 is provided between the protective layer 27 and the protective layer 29. The light-shielding layer 28 has a through-hole 28a for each pixel and a protrusion 28b protruding toward the isolation structure 23A at the boundary between adjacent pixels. The light-shielding layer 28 is made of, for example, a metal or a metal compound mainly composed of Ag, Al, Ti, W, Ni, Ta, Cu, or Au. The light-shielding layer 28 may be, for example, a single layer made of the above-mentioned material or a laminate film selected from the above-mentioned materials. The light-shielding layer 28 may have an anti-reflection layer on its surface facing the on-chip lens layer 51 (described later). Examples of the anti-reflection layer include a transparent inorganic layer (e.g., a layer made of TiN, W, TaN, etc.) having a refractive index different from that of the on-chip lens layer 51, or a light-absorbing resin layer (e.g., a resin layer containing carbon).

[0040] The through-hole 28a has an opening diameter that functions as a pinhole. The opening diameter of the through-hole 28a is, for example, equal to or larger than the focused diameter (spot diameter) of each lens in the on-chip lens layer 51 described below, but smaller than the diameter of each lens in the on-chip lens layer 51. The opening diameter of the through-hole 28a is, for example, larger than 10 nm and smaller than 100 μm. The through-hole 28a has, for example, a circular shape in a plan view.

[0041] The protrusions 28b, together with the isolation structure 23A, are capable of suppressing color mixing due to light leakage between pixels P. The protrusions 28b have a lattice structure, for example, as shown in Fig. 4. The protrusions 28b may also have a honeycomb structure, for example, as shown in Fig. 6.

[0042] The light-emitting unit 10 has an on-chip lens layer 51 on the protective layer 29. The on-chip lens layer 51 is provided, for example, so as to cover the entire surfaces of the display unit 100A and the frame unit 100B. The on-chip lens layer 51 has a plurality of lenses, one for each pixel P. The on-chip lens layer 51 is made of a light-transmitting material, and is formed, for example, of a single-layer film made of any of silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiCN), etc., or a stacked film made of two or more of these materials.

[0043] The wiring layer 30 is disposed between the light-emitting layer 20 (plurality of light-emitting elements 21) and the drive substrate 40. The wiring layer 30 includes an interlayer insulating film 31 and wiring 32 provided in the interlayer insulating film 31. The wiring layer 30 further includes, for each pixel, lead electrodes 33 and 35 that are exposed on the surface of the interlayer insulating film 31 facing the light-emitting elements 21. The lead electrode 33 is connected to the plug 21a. The lead electrode 35 is connected to the plug 21b.

[0044] The wiring layer 30 further includes pad electrodes 34, 36 exposed on the surface of the interlayer insulating film 31 facing the drive substrate 40, and a wiring layer 39 exposed on the surface of the interlayer insulating film 31 facing the light-emitting element 21. The wiring layer 30 includes the pad electrodes 34, 36 for each pixel P. The wiring 32 includes, for example, a wiring connecting the lead electrode 33 and the pad electrode 34 for each pixel P, and a wiring connecting the lead electrode 35 and the pad electrode 36 for each pixel P. The wiring 32 further includes, for example, a wiring connecting the wiring layer 39 and the lead electrode 35. The wiring 32, the wiring layer 39, and the pad electrodes 34, 36 are made of, for example, Cu. The lead electrodes 33, 35 are made of, for example, a metal or metal compound mainly composed of Ti, W, Al, Ni, Ta, Cu, Ag, or Au.

[0045] In the frame portion 100B, the wiring layer 30 has an electrode layer 37 exposed on the surface of the interlayer insulating film 31 facing the drive substrate 40, and a pad electrode 38 exposed on the surface of the interlayer insulating film 31 facing the light-emitting element 21. The wiring 32 has, for example, a wiring that connects the electrode layer 37 and the pad electrode 38. The pad electrode 38 is electrically connected to the drive circuit 42 of the drive substrate 40. As a result, the electrode layer 37 is electrically connected to the drive circuit 42 of the drive substrate 40 via the wiring 32 and the pad electrode 38.

[0046] The light-emitting layer 20 has an opening H1 in the frame portion 100B that penetrates the protective layer 29, the light-shielding layer 28, the protective layer 27, and the insulating layer 22 and reaches the electrode layer 37. The light-emitting layer 20 further has an opening H2 in the frame portion 100B that penetrates the protective layer 29, the light-shielding layer 28, the protective layer 27, and the insulating layer 22 and reaches the wiring layer 39. The light-emitting layer 20 has an extraction electrode 52 that is electrically connected to the electrode layer 37 exposed at the bottom of the opening H1 in the frame portion 100B. The light-emitting layer 20 has an extraction electrode 53 that is electrically connected to the wiring layer 39 exposed at the bottom of the opening H2 in the frame portion 100B.

[0047] Next, the drive substrate 40 will be described.

[0048] The drive substrate 40 is provided with a drive circuit 42 that drives the plurality of light-emitting elements 21 arranged in the display unit 100A, etc. The drive substrate 40 is disposed in a position facing the plurality of wavelength conversion layers 26 with the plurality of light-emitting elements 21 interposed therebetween. The drive substrate 40 has a support substrate 41 made of, for example, silicon (Si), and a wiring layer 43 provided on the support substrate 41. The wiring layer 43 is provided with an interlayer insulating film 44, vertical wiring 45 embedded in the interlayer insulating film 44, and pad electrodes 46, 47, and 48.

[0049] The vertical wiring 45 includes wiring that electrically connects the pad electrode 46 and the drive circuit 42, wiring that electrically connects the pad electrode 47 and the drive circuit 42, and wiring that electrically connects the pad electrode 48 and the drive circuit 42. The pad electrode 46 is exposed on the surface of the interlayer insulating film 44 that faces the wiring layer 30, and is joined to the pad electrode 34. The pad electrode 47 is exposed on the surface of the interlayer insulating film 44 that faces the wiring layer 30, and is joined to the pad electrode 36. The pad electrode 48 is exposed on the surface of the interlayer insulating film 44 that faces the wiring layer 30, and is joined to the pad electrode 38.

[0050] The interlayer insulating film 44 is made of, for example, silicon oxide (SiO) or silicon nitride (SiN). The vertical wiring 45 includes, for example, vias. The vertical wiring 45 is made of, for example, Cu, Al, W, Ag, or an alloy thereof. The pad electrodes 46, 47, and 48 are made of, for example, Cu.

[0051] (1-2. Manufacturing Method of Light-Emitting Device) Next, a manufacturing method of the light-emitting device 1 will be described. Fig. 9A shows an example of a cross-sectional configuration for explaining an example of a manufacturing process of the light-emitting device 1. Figs. 9B to 9K show examples of cross-sectional configurations in steps subsequent to Fig. 9A.

[0052] In order to manufacture the light emitting device 1, for example, a compound semiconductor is formed in one step on the SOI substrate 120 by an epitaxial crystal growth method such as MOCVD (Metal Organic Chemical Vapor Deposition). In this case, the raw materials for the compound semiconductor include, for example, methyl-based organometallic gases such as trimethylaluminum (TMAl), trimethylgallium (TMGa), and trimethylindium (TMIn), and phosphine (PH ３ ) gas and arsine (AsH ３ ) gas is used, and the source of the donor impurity is, for example, disilane (Si ２ H ６ ) is used, and the raw material of the acceptor impurity is, for example, carbon tetrabromide (CBr ４ ) is used.

[0053] First, an n-type compound semiconductor layer 111, an active layer 112, and a p-type compound semiconductor layer 113 are formed on an SOI substrate 120 by epitaxial crystal growth, such as MOCVD (Modular Organic Chemical Vapor Deposition). Next, an electrode layer 114 is formed by, for example, CVD (Chemical Vapor Deposition) or ALD (Atomic Layer Deposition) (FIG. 9A). Next, the electrode layer 114, the p-type compound semiconductor layer 113, the active layer 112, and the n-type compound semiconductor layer 111 are selectively etched by, for example, RIE (Reactive Ion Etching). This results in multiple light-emitting elements 21 having a mesa shape (mesa portion 21B) (FIG. 9B). At this time, the multiple light-emitting elements 21 are separated from one another by, for example, etching down to the SOI substrate 120.

[0054] Next, an insulating layer 24, a reflective layer 23, and an insulating layer 22 are formed by, for example, CVD or ALD to cover the plurality of light-emitting elements 21 ( FIG. 9C ). Next, a trench 22A reaching the flat surface 21D and a trench 22B reaching the top 21C are formed in the insulating layer 22 by, for example, wet etching. Subsequently, plugs 21a and 21b are formed by filling the trenches 22A and 22B with a metal material by, for example, CVD or ALD ( FIG. 9C ). This results in a light-emitting layer 20′ on the SOI substrate 120. Next, a wiring layer 30 is formed on the insulating layer 22 ( FIG. 9D ). At this time, each light-emitting element 21 included in the light-emitting layer 20′ is electrically connected to the wiring layer 30. This results in a light-emitting substrate 110 in which the light-emitting layer 20′ and the wiring layer 30 are stacked on the SOI substrate 120 ( FIG. 9D ).

[0055] Next, the light emitting substrate 110 is bonded to the drive substrate 40 with the wiring layer 30 facing the drive substrate 40 (FIGS. 9E and 9F). Next, the Si substrate (semiconductor substrate) and the SiO ２ The layer (oxide film) is removed ( FIG. 9G ). This exposes the Si layer 121 of the SOI substrate 120 ( FIG. 9G ). Next, after removing the Si layer 121 by, for example, wet etching, the n-type compound semiconductor layer 111 of each light-emitting element 21 is etched by, for example, RIE, to form a recess 21A in the n-type compound semiconductor layer 111 ( FIG. 9H ). At this time, the n-type compound semiconductor layer 111 is exposed on the inner surface of the recess 21A.

[0056] Next, an insulating layer 25 is formed in contact with the inner surface of each recess 21A so as to fit along the inner surface of each recess 21A ( FIG. 9I ). Subsequently, for example, using a printing method, ink serving as the raw material for the wavelength conversion layer 26R is ejected into a specific recess 21A, ink serving as the raw material for the wavelength conversion layer 26G is ejected into a specific recess 21A, and ink serving as the raw material for the wavelength conversion layer 26B is ejected into a specific recess 21A. This forms the wavelength conversion layers 26R, 26G, and 26B so as to fill each recess 21A ( FIG. 9J ). Next, for example, a protective layer 27, a light-shielding layer 28, and a protective layer 29 are formed on the surface including the wavelength conversion layers 26R, 26G, and 26B by CVD or ALD ( FIG. 9K ). After that, lead electrodes 52 and 53 are formed on the frame portion 100B, and then an on-chip lens layer 51 is formed on at least the display portion 100A. In this manner, the light-emitting device 1 is manufactured.

[0057] (1-3. Actions and Effects) Next, the effects of the light emitting device 1 will be described.

[0058] A light-emitting device including a micro-light-emitting element is disclosed in, for example, Patent Document 1. In the invention described in Patent Document 1, a micro-light-emitting element and a wavelength conversion layer that converts the wavelength of light emitted from the micro-light-emitting element are provided for each pixel, and an isolation structure that isolates each pixel is provided between the micro-light-emitting elements and between the wavelength conversion layers.

[0059] In the invention described in Patent Document 1, if the separation structure (hereinafter referred to as the "first separation structure") between wavelength conversion layers is larger than the separation structure (hereinafter referred to as the "second separation structure") between micro light-emitting elements, the light emitted from the micro light-emitting elements is blocked by the first separation structure, making it difficult for the light to reach the wavelength conversion layer. As a result, the light extraction efficiency may decrease. Furthermore, because the first separation structure and the second separation structure are formed in separate processes, the proportion of the light emitted from the micro light-emitting elements that is blocked by the first separation structure is likely to vary from product to product due to processing variations. As a result, the light extraction efficiency may vary from product to product.

[0060] On the other hand, in this embodiment, a recess 21A is provided in the n-type compound semiconductor layer 111 of each light-emitting element 21, and the recess 21A accommodates all or part of the corresponding wavelength conversion layer 26. As a result, for example, by providing an isolation structure 23A between the light-emitting elements 21 to separate the light-emitting elements 21, the isolation structure 23A can also serve as an isolation structure to separate the wavelength conversion layers 26. Furthermore, by providing the isolation structure 23A between the light-emitting elements 21, light emitted from the light-emitting elements 21 can be incident on the wavelength conversion layer 26 without being blocked by the isolation structure 23A. As a result, it is possible to suppress a decrease in light extraction efficiency and product-to-product variation caused by the isolation structure 23A.

[0061] In this embodiment, each light-emitting element 21 has a mesa shape, and a recess 21A is provided at the bottom of the mesa shape. This allows the overall height of the light-emitting element 21 and the wavelength conversion layer 26 to be lower than, for example, when a wavelength conversion layer is formed on the light-emitting element without providing a recess in the light-emitting element. As a result, the height of the isolation structure 23A can also be lowered, and the isolation grooves (grooves between the light-emitting elements 21) for forming the isolation structure 23A can be made shallower. This reduces the difficulty of the manufacturing process.

[0062] In this embodiment, the reflective layer 23 is provided so as to extend continuously from a portion facing the top 21C of the mesa portion 21B to a portion of the side surface of the mesa portion 21B facing the side surface of the wavelength conversion layer 26. In this case, the portion of the reflective layer 23 provided at the boundary between two adjacent pixels P is provided in the region between two adjacent light-emitting elements 21 and in the region between two adjacent wavelength conversion layers 26. In other words, a portion of the reflective layer 23 not only functions as an isolation structure separating the light-emitting elements 21 but also as an isolation structure separating the wavelength conversion layers 26. As a result, it is not necessary to provide a separate isolation structure separating the wavelength conversion layers 26 (hereinafter referred to as a "first isolation structure") and a separate isolation structure separating the light-emitting elements 21 (hereinafter referred to as a "second isolation structure"). Therefore, the light emitted from the light-emitting element 21 is not blocked by the first separation structure, and the proportion of the light emitted from the light-emitting element 21 that is blocked by the first separation structure does not vary from product to product due to processing variations. From the above, in this embodiment, it is possible to suppress a decrease in light extraction efficiency and variations from product to product that are caused by the separation structure.

[0063] In this embodiment, the on-chip lens layer 51 includes a plurality of lenses, one for each pixel (Pr, Pg, Pb), and the light-shielding layer 28 includes a plurality of through-holes 28a, one for each pixel (Pr, Pg, Pb). In this case, the light-shielding layer 28 is provided with protrusions 28b that protrude toward the reflective layer 23 (separation structure 23A) at the boundary portions of the pixels (Pr, Pg, Pb). This, together with the separation structure 23A, can suppress color mixing due to light leaking between the pixels (Pr, Pg, Pb).

[0064] In this embodiment, the n-type compound semiconductor layer 111 of each light-emitting element 21 is etched to form recesses 21A in the n-type compound semiconductor layer 111, and then the wavelength conversion layer 26 is formed to fill each recess 21A. As a result, for example, by providing an isolation structure 23A between the light-emitting elements 21 to separate the light-emitting elements 21, the isolation structure 23A can also serve as an isolation structure to separate the wavelength conversion layers 26. Furthermore, by providing the isolation structure 23A between the light-emitting elements 21, light emitted from the light-emitting elements 21 can be incident on the wavelength conversion layer 26 without being blocked by the isolation structure 23A. As a result, it is possible to suppress a decrease in light extraction efficiency and product-to-product variation due to the isolation structure 23A.

[0065] In the present embodiment, the insulating layer 25 is formed in contact with the inner surface of each recess 21A so as to fit along the inner surface of each recess 21A, and then the wavelength conversion layer 26 is formed to fill each recess 21A. This allows the surface of the n-type compound semiconductor layer 111 (the inner surface of the recess 21A) to be protected by the insulating layer 25 during the manufacturing process.

[0066] In this embodiment, the reflective layer 23 is formed continuously from a portion facing the top 21C of the mesa portion 21B to a portion of the side surface of the mesa portion 21B facing the side surface of the wavelength conversion layer 26. In this case, the portion of the reflective layer 23 provided at the boundary between two adjacent pixels P is provided in the region between two adjacent light-emitting elements 21 and in the region between two adjacent wavelength conversion layers 26. That is, a portion of the reflective layer 23 not only functions as an isolation structure separating the light-emitting elements 21, but also as an isolation structure separating the wavelength conversion layers 26. As a result, it is not necessary to separately provide a first isolation structure separating the wavelength conversion layers 26 and a second isolation structure separating the light-emitting elements 21. Therefore, the light emitted from the light-emitting elements 21 is not blocked by the first isolation structure, and the proportion of the light emitted from the light-emitting elements 21 that is blocked by the first isolation structure does not vary from product to product due to processing variations. As described above, in this embodiment, it is possible to suppress the decrease in light extraction efficiency and the variation between products caused by the separation structure.

[0067] 2. Modifications Modifications of the light emitting device 1 according to the above embodiment will be described below.

[0068] (2-1. Modification A) FIG. 10 shows a modification of the cross-sectional configuration of the light-emitting device 1 according to the above embodiment. FIG. 11 shows an example of the cross-sectional configuration of the light-emitting element 21 of FIG. 10 and its vicinity. In the above embodiment, for example, as shown in FIGS. 10 and 11, the flat surface 21D of the n-type compound semiconductor layer 111 may be exposed on the side surface of the mesa portion 21B. In this case, the reflective layer 23 may be a metal wiring layer in contact with the flat surface 21D. This makes it possible to omit the plug 21b and the extraction electrode 35, thereby facilitating the miniaturization of each pixel P.

[0069] Furthermore, in this modification, since the reflective layer 23 is electrically connected to the n-type compound semiconductor layer 111, for example, by providing a plug 54 connecting the reflective layer 23 and the wiring layer 39 in the frame portion 100B, a predetermined voltage (e.g., a reference voltage) can be supplied to the n-type compound semiconductor layer 111 of each light-emitting element 21 via the extraction electrode 53, the wiring layer 39, and the reflective layer 23. The plug 54 is, for example, composed of a columnar metal member formed to fill a trench formed in the insulating layer 22. The plug 54 is, for example, composed of a metal or metal compound containing Ti, W, Al, Ni, Ta, Cu, Ag, or Au as a main component. The plug 54 is formed, for example, by CVD or ALD. The plug 54 may be, for example, a single layer composed of the above-mentioned material, or a laminate film selected from the above-mentioned materials.

[0070] (2-2. Modification B) Fig. 12 shows a modification of the cross-sectional configuration of Fig. 11. In the above modification A, for example, as shown in Fig. 12, a side surface 21E of the n-type compound semiconductor layer 111 may be exposed on the side surface of the mesa portion 21B, instead of the flat surface 21D. In this case, the reflective layer 23 may be a metal wiring layer in contact with the side surface 21E. This makes it possible to omit the plug 21b and the extraction electrode 35, thereby facilitating miniaturization of each pixel P.

[0071] (2-3. Modification C) FIG. 13 shows a modification of the cross-sectional configuration of FIG. 12 . In the above modification B, the recess 21A and the mesa portion 21B may be formed so that their respective center lines L1 and L2 in the stacking direction overlap each other in a vertical cross-sectional view, as shown in FIG. 13 , for example. The center line L1 is the center line of the recess 21A in the stacking direction. The center line L2 is the center line of the mesa portion 21B in the stacking direction. This allows light emitted from the light emitting element 21 to be more efficiently incident on the wavelength conversion layer 26. In this case, if the center lines L1 and L2 are positioned so as to pass through the through hole 28a, the radiation angle dependency of the optical characteristics of the light that has passed through the through hole 28a can be reduced.

[0072] In this modification C, for example, the side surface of the mesa portion 21B may have no steps and may be a smoothly inclined surface, as shown in Fig. 14. Even in this case, the same effect as described above can be obtained.

[0073] (2-4. Modification D) FIG. 15 shows a modification of the cross-sectional configuration of FIG. 2. FIG. 16 shows a modification of the cross-sectional configuration of FIG. 11. In the above-described embodiment and modification A, the n-type compound semiconductor layer 111 may be, for example, a laminate having an n-type semiconductor layer 111A on which a flat surface 21D is formed and an undoped semiconductor layer 111B provided in contact with the n-type compound semiconductor layer 11A. The undoped semiconductor layer 111B has a recess 21A, and the wavelength conversion layer 26 is in contact with the undoped semiconductor layer 111B. The undoped semiconductor layer 111B is made of, for example, undoped GaN, undoped AlGaN, undoped AlN, or undoped AlInGaN.

[0074] In this case, the portions of the light emitting element 21 that are not required as current paths are made up of the undoped semiconductor layer 111B, so that current leakage to adjacent pixels can be reduced.

[0075] (2-5. Modification E) Fig. 17 shows a modification of the cross-sectional configuration of Fig. 2. Fig. 18 shows a modification of the cross-sectional configuration of Fig. 2. Fig. 19 shows a modification of the cross-sectional configuration of Fig. 2.

[0076] In the above-described embodiment and its modified examples, for example, as shown in FIG. 17 , an asperity 21F may be formed on the bottom surface of the recess 21A, and an asperity 26-1 may be formed on the wavelength conversion layer 26 along the asperity 21F. The asperity 21F corresponds to a specific example of a "first asperity" according to an embodiment of the present disclosure. The asperity 26-1 corresponds to a specific example of a "second asperity" according to an embodiment of the present disclosure. The asperity 21F may be formed, for example, by performing dry etching such as RIE on the bottom surface of the recess 21A. By forming such asperities 21F and 26-1, the proportion of light traveling from the n-type compound semiconductor layer 111 to the wavelength conversion layer 26 that is totally reflected at the interface of the wavelength conversion layer 26 on the n-type compound semiconductor layer 111 side can be reduced. As a result, the light extraction efficiency can be improved.

[0077] In the above-described embodiment and its modified examples, for example, as shown in FIG. 18 , the recess 21A may have an asperity 21G formed on the bottom surface thereof, and the insulating layer 25 may have an asperity 25-1 formed along the asperity 21G. In this case, the wavelength conversion layer 26 may not have an asperity along the asperity 21F. The asperity 21G corresponds to a specific example of a "first asperity" according to an embodiment of the present disclosure. The asperity 25-1 corresponds to a specific example of a "third asperity" according to an embodiment of the present disclosure. The asperity 21G may be formed, for example, by wet etching the bottom surface of the recess 21A using an etchant such as KOH. The formation of such asperities 21G and 25-1 can reduce the proportion of light traveling from the n-type compound semiconductor layer 111 to the wavelength conversion layer 26 that is totally reflected at the interface of the wavelength conversion layer 26 on the n-type compound semiconductor layer 111 side. As a result, the light extraction efficiency can be improved.

[0078] In the above-described embodiment and its modified examples, for example, as shown in FIG. 19 , the insulating layer 25 may have an asperity 25A formed on the surface thereof facing the wavelength conversion layer 26, and the wavelength conversion layer 26 may have an asperity 26-2 formed along the asperity 25A. The asperity 25A corresponds to a specific example of a "fourth asperity" according to an embodiment of the present disclosure. The asperity 26-2 corresponds to a specific example of a "fifth asperity" according to an embodiment of the present disclosure. The asperity 25A may be formed, for example, by wet etching the surface of the insulating layer 25 facing the wavelength conversion layer 26. The formation of such asperities 25A and 26-2 can reduce the proportion of light traveling from the n-type compound semiconductor layer 111 to the wavelength conversion layer 26 that is totally reflected at the interface of the wavelength conversion layer 26 facing the n-type compound semiconductor layer 111. As a result, the light extraction efficiency can be improved.

[0079] (2-6. Modification F) FIG. 20 shows a modification of the cross-sectional configuration of FIG. 2. In the above-described embodiment and its modifications, the insulating layer 25 may be formed of a multilayer film in which two adjacent layers have different refractive indices, as shown in FIG. 20, for example. When the electrode layer 114 is formed of a metal material, a multilayer film is used as the insulating layer 25, and a cavity is formed by this multilayer film and the electrode layer 114. This allows light of a specific wavelength to be incident on the wavelength conversion layer 26, improving the conversion efficiency of the wavelength conversion layer 26. As a result, the light extraction efficiency can be improved.

[0080] (2-7. Modification G) Figure 21 shows a modification of the cross-sectional configuration of Figure 2. In the above embodiment and its modifications, for example, as shown in Figure 21, the insulating layer 25 may be omitted, and the inner surface of the recess 21A and the wavelength conversion layer 26 may be in contact with each other. Even in this case, as in the above embodiment, it is possible to suppress the reduction in light extraction efficiency and product-to-product variation caused by the separation structure 23A.

[0081] (2-8. Variation H) Fig. 22 shows a variation of the cross-sectional configuration of Fig. 2. In the above embodiment and its variations, the protrusion 28b may be in contact with the reflective layer 23 (separation structure 23A), for example, as shown in Fig. 22. In this case, the protrusion 28b and the separation structure 23A can suppress color mixing due to light leaking between pixels P.

[0082] (2-9. Modification I) FIG. 23 shows a modification of the cross-sectional configuration of FIG. 10. FIG. 24 shows an example of the cross-sectional configuration of the light-emitting element 21 of FIG. 23 and its vicinity. In the above modification H, for example, as shown in FIGS. 23 and 24, the flat surface 21D of the n-type compound semiconductor layer 111 may be exposed on the side surface of the mesa portion 21B. In this case, the reflective layer 23 may be a metal wiring layer in contact with the flat surface 21D. This makes it possible to omit the plug 21b and the extraction electrode 35, thereby facilitating the miniaturization of each pixel P.

[0083] In this modification, the light-shielding layer 28 is electrically connected to the n-type compound semiconductor layer 111 via the reflective layer 23, and therefore, for example, by providing the frame portion 100B with an extraction electrode 57 in contact with the wiring layer 39, a predetermined voltage (for example, a reference voltage) can be supplied to the n-type compound semiconductor layer 111 of each light-emitting element 21 via the extraction electrode 53, the wiring layer 39, the extraction electrode 57, the light-shielding layer 28, and the reflective layer 23. The extraction electrode 57 is electrically connected to the wiring layer 39 via, for example, an opening H3 that penetrates the insulating layer 22.

[0084] In this modification, the recess 21A and the mesa portion 21B may be formed such that their center lines L1 and L2 in the stacking direction overlap each other in a vertical cross-sectional view, as shown in FIG. 25 . The center line L1 is the center line of the recess 21A in the stacking direction. The center line L2 is the center line of the mesa portion 21B in the stacking direction. This allows light emitted from the light emitting element 21 to be more efficiently incident on the wavelength conversion layer 26. In this case, if the center lines L1 and L2 are positioned so as to pass through the through hole 28a, the radiation angle dependency of the optical characteristics of the light that has passed through the through hole 28a can be reduced.

[0085] 25, the side surface of the mesa portion 21B may have no steps and may be a smoothly inclined surface. Even in this case, the same effect as described above can be obtained.

[0086] (2-10. Modification J) Fig. 26 shows a modification of the cross-sectional configuration of Fig. 2. In the above embodiment and its modifications, the light-emitting layer 20 may have an organic DBR (Distributed Bragg Reflector) layer 55 between the light-shielding layer 28 and the on-chip lens layer 51, for example, as shown in Fig. 26.

[0087] The organic DBR layer 55 is made of, for example, a multilayer organic film in which two adjacent layers have different refractive indices. The film thickness of each layer included in the multilayer organic film is, for example, ¼ of the wavelength of light emitted from the wavelength conversion layer 26. When the electrode layer 114 is made of a metal material, a cavity is formed by the organic DBR layer 55 and the electrode layer 114. This allows light of a specific wavelength to be incident on the wavelength conversion layer 26, improving the conversion efficiency of the wavelength conversion layer 26. As a result, the light extraction efficiency can be improved.

[0088] (2-11. Modification K) Fig. 27 shows a modification of the cross-sectional configuration of Fig. 2. In the above embodiment and its modifications, the reflective layer 23 may be formed of, for example, a resin layer having light reflectivity or a dielectric multilayer reflective layer having light reflectivity, as shown in Fig. 27. Even in this case, the isolation structure 23A can be formed by the reflective layer 23.

[0089] (2-12. Modification L) FIGS. 28, 29, and 30 show a modification of the cross-sectional configuration of FIG. 2. In the above embodiment and its modifications, for example, as shown in FIG. 28, the sidewall portion of the recess 21A provided in the n-type compound semiconductor layer 111 may be made shallow by etching. Also, in the above embodiment and its modifications, for example, as shown in FIG. 29, the sidewall portion of the recess 21A provided in the n-type compound semiconductor layer 111 may be eliminated by etching. Also, in the above embodiment and its modifications, for example, as shown in FIG. 30, the sidewall portion of the recess 21A provided in the n-type compound semiconductor layer 111 may be partially cut out.

[0090] In this case, the wavelength conversion layer 26 is formed to fill the recess formed by the recess 21A and the insulating layer 24 exposed by etching the sidewall portion of the recess 21A. Even in this case, as in the above embodiment and its modified example, the wavelength conversion layers 26 are separated from each other by the separation structure 23A formed by the reflective layer 23. Furthermore, because this separation structure 23A is provided between the light-emitting elements 21, light emitted from the light-emitting elements 21 can be incident on the wavelength conversion layer 26 without being blocked by this separation structure 23A. As a result, it is possible to suppress a decrease in light extraction efficiency and product-to-product variation caused by the separation structure 23A.

[0091] (2-13. Modification M) Fig. 31 shows a modification of the cross-sectional configuration of Fig. 2. In the above embodiment and its modifications, for example, as shown in Fig. 31, only a part of the wavelength conversion layer 26 may be provided in the area surrounded by the recess 21A.

[0092] In this case, the portion of the wavelength conversion layer 26 that extends beyond the region surrounded by the recess 21A is provided within the region surrounded by the separation structure 23A in a planar view, as shown in FIG. 31 . Even in this case, as in the above-described embodiment and its modified examples, the wavelength conversion layers 26 are separated from each other by the separation structure 23A formed by the reflective layer 23 and the protrusion 28b of the light-shielding layer 28. Furthermore, since the separation structure 23A is provided between the light-emitting elements 21, light emitted from the light-emitting elements 21 can be incident on the wavelength conversion layer 26 without being blocked by the separation structure 23A. Furthermore, the light emitted from the light-emitting elements 21 is not blocked by the protrusion 28b, preventing it from reaching the wavelength conversion layer 26. Therefore, it is possible to suppress a decrease in light extraction efficiency and product-to-product variation caused by the separation structure 23A and the protrusion 28b.

[0093] (2-14. Variation N) Fig. 32 shows a variation of the cross-sectional configuration of Fig. 1. Fig. 33 shows an enlarged cross-sectional configuration example of a part (light-emitting element 21 and its vicinity) of light-emitting device 1 shown in Fig. 32. Fig. 34 shows a cross-sectional configuration example taken along line A-A in Fig. 33. In Fig. 34, insulating layer 22, reflective layer 23, and insulating layer 25 are omitted. Fig. 35 shows a cross-sectional configuration example taken along line B-B in Fig. 33.

[0094] In the above-described embodiment and its modified examples, for example, as shown in FIGS. 32 to 35 , a conductive layer 56 may be provided instead of the insulating layer 25. The conductive layer 56 is provided between the inner surface of the recess 21A of the n-type compound semiconductor layer 111 and the wavelength conversion layer 26, and is in contact with the inner surface of the recess 21A and the wavelength conversion layer 26. The conductive layer 56 is in contact with the protrusion 28b of the light-shielding layer 28 and is electrically connected to the light-shielding layer 28. The conductive layer 56 is made of a metal or metal compound containing, for example, Ag, Al, Ti, W, Ni, Ta, Cu, or Au as a main component. Therefore, the conductive layer 56 is a metal wiring layer in contact with the n-type compound semiconductor layer 111 and the light-shielding layer 28.

[0095] In this modification, the plurality of pixels P are arranged in a two-dimensional array in a planar view. When each pixel P has a square shape in a planar view, the plurality of pixels P are arranged in a matrix, for example, as shown in Figures 34 and 35. When each pixel P has a hexagonal shape in a planar view, the plurality of pixels P may be arranged in a honeycomb shape, for example, as shown in Figures 36 and 37.

[0096] In this modification, the separation structure 23A has, for example, a lattice structure as shown in Fig. 35. The separation structure 23A may have, for example, a honeycomb structure as shown in Fig. 37. The separation structure 23A may have, for example, a dot-like structure in which a lattice structure is finely divided as shown in Fig. 38. The separation structure 23A may also have, for example, a dot-like structure in which a honeycomb structure is finely divided as shown in Fig. 39.

[0097] [Manufacturing Method] Next, a manufacturing method of the light emitting device 1 according to this modified example will be described. Fig. 40A shows an example of a cross-sectional configuration for explaining an example of a manufacturing process of the light emitting device 1 according to this modified example. Fig. 40A shows an example of a cross-sectional configuration in a step subsequent to Fig. 9H. Figs. 40B and 40C show examples of a cross-sectional configuration in a step subsequent to Fig. 40A.

[0098] First, as shown in FIG. 9H, recesses 21A are formed in the n-type compound semiconductor layer 111, and the n-type compound semiconductor layer 111 is exposed on the inner surface of the recesses 21A. Next, as shown in FIG. 40A, a conductive layer 56 is formed by, for example, CVD or ALD, so as to conform to the inner surface of each recess 21A and contact the inner surface of each recess 21A (FIG. 40A). Next, for example, using a printing method, ink serving as the raw material for the wavelength conversion layer 26R is ejected into a specific recess 21A, ink serving as the raw material for the wavelength conversion layer 26G is ejected into a specific recess 21A, and ink serving as the raw material for the wavelength conversion layer 26B is ejected into a specific recess 21A. This forms the wavelength conversion layers 26R, 26G, and 26B so as to fill each recess 21A (FIG. 40B). Next, for example, an opening H3 is formed through the insulating layer 22 by etching, and the wiring layer 39 is exposed at the bottom of the opening H3 (FIG. 40C). Next, an extraction electrode 57 in contact with the wiring layer 39 is formed in the opening H3 and on the surface of the insulating layer 22 by CVD or ALD, and then a protective layer 27, a light-shielding layer 28, and a protective layer 29 are formed on the surface including the extraction electrode 57 and the wavelength conversion layers 26R, 26G, and 26B ( FIG. 40C ). At this time, the light-shielding layer 28 is formed so as to be in contact with the extraction electrode 57. Thereafter, extraction electrodes 52 and 53 are formed on the frame unit 100B, and then an on-chip lens layer 51 is formed on at least the display unit 100A. In this manner, the light-emitting device 1 according to this modification is manufactured.

[0099] In this modification, the conductive layer 56 is provided between the inner surface of the recess 21A of the n-type compound semiconductor layer 111 and the wavelength conversion layer 26, and is in contact with the inner surface of the recess 21A and the wavelength conversion layer 26. Furthermore, the conductive layer 56 is a metal wiring layer in contact with the light-shielding layer 28. This makes it possible to omit the plug 21b and the extraction electrode 35, thereby facilitating miniaturization of each pixel P.

[0100] Furthermore, in this modification, the light-shielding layer 28 is electrically connected to the n-type compound semiconductor layer 111 via the conductive layer 56. Therefore, for example, by providing the frame portion 100B with an extraction electrode 57 that contacts the wiring layer 39, a predetermined voltage (e.g., a reference voltage) can be supplied to the n-type compound semiconductor layer 111 of each light-emitting element 21 via the extraction electrode 53, the wiring layer 39, the extraction electrode 57, the light-shielding layer 28, and the conductive layer 56.

[0101] In this modification, the recess 21A and the mesa portion 21B may be formed such that their center lines L1 and L2 in the stacking direction overlap each other in a vertical cross-sectional view, as shown in FIG. 33 . The center line L1 is the center line of the recess 21A in the stacking direction. The center line L2 is the center line of the mesa portion 21B in the stacking direction. This allows light emitted from the light-emitting element 21 to be more efficiently incident on the wavelength conversion layer 26. In this case, if the center lines L1 and L2 are positioned so as to pass through the through hole 28a, the radiation angle dependency of the optical characteristics of the light that has passed through the through hole 28a can be reduced.

[0102] (2-15. Modification O) Fig. 41 shows a modification of the cross-sectional configuration of Fig. 1. Figs. 42 and 43 show enlarged cross-sectional configuration examples of a portion of the light-emitting device 1 shown in Fig. 41. Fig. 42 shows an example of the horizontal cross-sectional configuration of a portion corresponding to line A-A in Fig. 2 in pixel P of the light-emitting device 1 shown in Fig. 41. Fig. 43 shows an example of the vertical cross-sectional configuration of dummy pixel Pd of the light-emitting device 1 shown in Fig. 41.

[0103] The light-emitting device 1 according to this modification corresponds to the light-emitting device 1 according to the modification N, further comprising one dummy pixel Pd for each color pixel Pcolor, as shown in FIG. 41 . In this modification, the color pixel Pcolor is configured with a red pixel Pr, a green pixel Pg, a blue pixel Pb, and a dummy pixel Pd, as shown in FIG. 42 . In the dummy pixel Pd, the light-emitting element 21 and the wavelength conversion layer 26 are omitted, and an opening H5 is provided in the insulating layer 22, reaching the wiring layer 58. Furthermore, a conductive layer 56 is provided on the inner surface of the opening H5 and on the surface of the insulating layer 22, and is in contact with the wiring layer 58 via the opening H5. The wiring layer 58 is connected to the plug 21a and electrically connected to the drive substrate 40 via the plug 21a and the extraction electrode 33.

[0104] In this modification, the n-type compound semiconductor layer 111 of the light-emitting element 21 of each pixel P is electrically connected to the drive substrate 40 via the dummy pixel Pd. This makes it possible to omit the plug 21b and the extraction electrode 35, thereby facilitating miniaturization of each pixel P.

[0105] (2-16. Modification P) FIG. 44 shows a modification of the cross-sectional configuration of FIG. 2. FIG. 45 shows a modification of the cross-sectional configuration of FIG. 33. In the above-described embodiment and its modifications, the wavelength conversion layer 26 may have a recess 26-3 at a location facing the through-hole 28a. The recess 26-3 acts as a condenser lens for light traveling from the wavelength conversion layer 26 toward the through-hole 28a via the recess 26-3. By providing the recess 26-3 on the surface of the wavelength conversion layer 26 in this way, the position of the through-hole 28a can be brought closer to the surface of the wavelength conversion layer 26. This allows the thickness of each pixel P to be thin, thereby enabling the light-emitting device 1 to be miniaturized.

[0106] The present disclosure has been described above by way of embodiments and their modified examples, but the present disclosure is not limited to the above embodiments, and various modifications are possible. Note that the effects described in this specification are merely examples. The effects of the present disclosure are not limited to the effects described in this specification. The present disclosure may have effects other than those described in this specification.

[0107] For example, in the above-described embodiment and its modified examples, the light-emitting element 21 may be made of an InP-based compound semiconductor. Examples of InP-based compound semiconductors include InP, GaInP, and AlGaInP. Also, for example, in the above-described embodiment and its modified examples, the light-emitting element 21 may be made of a GaP-based compound semiconductor.

[0108] Furthermore, for example, in the above-described embodiment and its modified examples, color filter layers may be provided instead of the wavelength conversion layers 26R, 26G, and 26B. The color filter layers are configured to absorb specific wavelengths contained in the light emitted from the light emitting elements 21, and in a broad sense, can be considered a type of wavelength conversion layer.

[0109] Furthermore, for example, in the above-described embodiment and its modified examples, the light emitting element 21 may be capable of emitting light in the green region or the red region.

[0110] The present disclosure may also be configured as follows: (1) A light-emitting device comprising: a plurality of light-emitting elements arranged two-dimensionally; and a plurality of wavelength conversion layers stacked one on the light-emitting side of the plurality of light-emitting elements and facing each of the light-emitting elements, wherein each of the light-emitting elements has a stacked body including a first conductivity-type semiconductor layer, an active layer, and a second conductivity-type semiconductor layer, in that order toward the wavelength conversion layer, and wherein the second conductivity-type semiconductor layer in each of the light-emitting elements has a recess or cutout portion, and the recess or cutout portion accommodates all or part of the corresponding wavelength conversion layer. (2) The light-emitting device described in (1), wherein the stacked body has a mesa shape with the first conductivity-type semiconductor layer side as its apex, and the recess or cutout portion is provided at the bottom of the mesa shape. (3) The light-emitting device described in (2), further comprising a reflective layer continuously formed from a portion facing the apex of the mesa shape to a portion of a side surface of the mesa shape facing the side surface of the wavelength conversion layer. (4) The light-emitting device according to (3), wherein a step is provided on a side surface of the mesa shape, exposing a flat surface of the second conductivity type semiconductor layer, and the reflective layer is a metal wiring layer in contact with the flat surface. (5) The light-emitting device according to any one of (1) to (4), wherein the second conductivity type semiconductor layer includes a conductive semiconductor layer having the flat surface formed thereon, and an undoped semiconductor layer in contact with the conductive semiconductor layer and having the recess or the notch provided thereon. (6) The light-emitting device according to (3), wherein a side surface of the second conductivity type semiconductor layer is exposed on a side surface of the mesa shape, and the reflective layer is a metal wiring layer in contact with the side surface of the second conductivity type semiconductor layer. (7) The light-emitting device according to (3), wherein the entire or part of the wavelength conversion layer is accommodated in the recess, and the recess and the mesa shape are formed so that center lines in the stacking directions of each overlap each other in a vertical cross-sectional view. (8) The light-emitting device according to any one of (1) to (7), wherein a first irregularity is formed on a bottom surface of the recess, and a second irregularity is formed on the wavelength conversion layer along the first irregularity.(9) The light-emitting device according to any one of claims 1 to 8, wherein the inner surface of the recess and the wavelength conversion layer are in contact with each other. (10) The light-emitting device according to any one of claims 1 to 7, further comprising an insulating layer provided between the inner surface of the recess and the wavelength conversion layer. (11) The light-emitting device according to (10), wherein a first unevenness is formed on the bottom surface of the recess, and a third unevenness is formed in the insulating layer along the first unevenness. (12) The light-emitting device according to (10), wherein a fourth unevenness is formed in the insulating layer, and a fifth unevenness is formed in the wavelength conversion layer along the fourth unevenness. (13) The light-emitting device according to (10), wherein the insulating layer is composed of a multilayer film in which two layers in contact with each other have different refractive indices. (14) The light-emitting device according to any one of (1) to (7), further comprising a conductive layer provided between the inner surface of the recess and the wavelength conversion layer, and in contact with the inner surface of the recess and the wavelength conversion layer. (15) The light-emitting device according to any one of (1) to (14), comprising: a plurality of lenses arranged at positions facing the plurality of light-emitting elements across the plurality of wavelength conversion layers, one for each pixel when pixels are formed by the opposing light-emitting elements and the wavelength conversion layers; and a light-shielding layer arranged between the plurality of lenses and the plurality of wavelength conversion layers, the light-shielding layer having a through-hole for each pixel and one or more protrusions protruding toward the reflective layer at boundaries between adjacent pixels. (16) The light-emitting device according to (15), further comprising a conductive layer provided between an inner surface of the recess and the wavelength conversion layer, the conductive layer being in contact with the inner surface of the recess and the wavelength conversion layer. (17) The light-emitting device according to (16), the conductive layer being in contact with the protrusion, and the light-shielding layer being a metal wiring layer electrically connected to the second conductivity-type semiconductor layer via the conductive layer. (18) The light-emitting device according to (15), in which the wavelength conversion layer has a recess at a position facing the through-hole.(19) A method for manufacturing a light emitting device, comprising: forming a plurality of light emitting elements on a semiconductor substrate, each including a second conductivity type semiconductor layer, an active layer, and a first conductivity type semiconductor layer in this order from the semiconductor substrate side, and then forming a wiring layer electrically connected to each of the light emitting elements to form a light emitting substrate; bonding a support substrate to the wiring layer of the light emitting substrate and then removing the semiconductor substrate; etching the second conductivity type semiconductor layer of each of the light emitting elements to form recesses or notches in the second conductivity type semiconductor layer, and then forming a wavelength conversion layer to fill each of the recesses or notches. (20) The method for manufacturing a light emitting device according to (19), comprising forming an insulating layer or a conductive layer in contact with an inner surface of each of the recesses or notches so as to follow the inner surface of each of the recesses or notches, and then forming the wavelength conversion layer to fill each of the recesses or notches. (21) The method for manufacturing a light-emitting device according to (19) or (20), comprising forming the plurality of light-emitting elements in a mesa shape with the first conductivity type semiconductor layer side as a top on the semiconductor substrate, forming a reflective layer that is continuous from a portion facing the top of the mesa shape to a portion of a side surface of the mesa shape that faces a side surface of the wavelength conversion layer, and further forming the wiring layer to form the light-emitting substrate.

[0111] This application claims priority based on Japanese Patent Application No. 2023-139471, filed on August 30, 2023, in the Japan Patent Office, the entire contents of which are incorporated herein by reference.

[0112] Those skilled in the art will recognize that various modifications, combinations, subcombinations, and variations may occur depending on design requirements and other factors, and are intended to be within the scope of the appended claims and their equivalents.

Claims

1. A light emitting device comprising: a plurality of light emitting elements arranged in a two-dimensional manner; and a plurality of wavelength conversion layers stacked one by one on the light emission side of the plurality of light emitting elements and facing each of the light emitting elements, wherein each of the light emitting elements has a stacked body including, in order toward the wavelength conversion layer, a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer, wherein each of the light emitting elements has a recess or cutout portion in the second conductivity type semiconductor layer, and the recess or cutout portion accommodates all or a part of the corresponding wavelength conversion layer.

2. The light emitting device according to claim 1, wherein the laminate has a mesa shape with the first conductive type semiconductor layer side as a top, and the recess or the notch is provided at the bottom of the mesa shape.

3. The light emitting device according to claim 2, further comprising a reflective layer formed continuously from a portion facing the top of the mesa shape to a portion of a side surface of the mesa shape facing a side surface of the wavelength conversion layer.

4. The light-emitting device according to claim 3, wherein a step is provided on a side surface of the mesa shape to expose a flat surface of the second conductive type semiconductor layer, and the reflective layer is a metal wiring layer in contact with the flat surface.

5. The light-emitting device according to claim 1, wherein the second conductive type semiconductor layer comprises a conductive semiconductor layer on which the flat surface is formed, and an undoped semiconductor layer provided in contact with the conductive semiconductor layer and having the recess or notch.

6. The light emitting device according to claim 3, wherein a side surface of the second conductive type semiconductor layer is exposed to a side surface of the mesa shape, and the reflective layer is a metal wiring layer in contact with the side surface of the second conductive type semiconductor layer.

7. The light emitting device according to claim 3, wherein the entirety or a part of the wavelength conversion layer is accommodated in the recess, and the recess and the mesa shape are formed so that their center lines in the stacking direction overlap each other in a vertical cross-sectional view.

8. The light emitting device according to claim 1, wherein a first unevenness is formed on a bottom surface of the recess, and a second unevenness is formed on the wavelength conversion layer in accordance with the first unevenness.

9. The light emitting device according to claim 1, wherein the inner surface of the recess and the wavelength conversion layer are in contact with each other.

10. The light emitting device according to claim 1, further comprising an insulating layer provided between the inner surface of the recess and the wavelength conversion layer.

11. The light emitting device according to claim 10, wherein a first unevenness is formed on a bottom surface of the recess, and a third unevenness is formed on the insulating layer in accordance with the first unevenness.

12. The light emitting device according to claim 10, wherein a fourth irregularity is formed on the insulating layer, and a fifth irregularity is formed along the fourth irregularity on the wavelength conversion layer.

13. The light emitting device according to claim 10, wherein the insulating layer is made of a multi-layer film in which two adjacent layers have mutually different refractive indices.

14. The light emitting device according to claim 1, further comprising a conductive layer provided between the inner surface of the recess and the wavelength conversion layer and in contact with the inner surface of the recess and the wavelength conversion layer.

15. The light-emitting device according to claim 1, comprising: a plurality of lenses, which are arranged at positions facing the plurality of light-emitting elements with the plurality of wavelength conversion layers between them, and which are arranged one for each pixel when pixels are formed by the light-emitting elements and the wavelength conversion layers facing each other; and a light-shielding layer, which is arranged between the plurality of lenses and the plurality of wavelength conversion layers, and which has a through-hole for each pixel and has one or more protrusions protruding towards the reflective layer at the boundary between adjacent pixels.

16. The light emitting device according to claim 15, further comprising a conductive layer provided between the inner surface of the recess and the wavelength conversion layer and in contact with the inner surface of the recess and the wavelength conversion layer.

17. The light-emitting device according to claim 16, wherein the conductive layer is in contact with the protrusion, and the light-shielding layer is a metal wiring layer electrically connected to the second conductive type semiconductor layer via the conductive layer.

18. The light emitting device according to claim 15, wherein the wavelength conversion layer has a recess in a position facing the through hole.

19. A method for manufacturing a light emitting device, comprising: forming a plurality of light emitting elements on a semiconductor substrate, the light emitting elements including a second conductivity type semiconductor layer, an active layer, and a first conductivity type semiconductor layer in that order from the semiconductor substrate side, and then forming a wiring layer electrically connected to each of the light emitting elements to form a light emitting substrate; bonding a support substrate to the wiring layer of the light emitting substrate, and then removing the semiconductor substrate; and etching the second conductivity type semiconductor layer of each of the light emitting elements to form recesses or cutouts in the second conductivity type semiconductor layer, and then forming a wavelength conversion layer so as to fill each of the recesses or cutouts.

20. A method for manufacturing a light emitting device as described in claim 19, comprising forming an insulating layer or conductive layer in contact with the inner surface of each of the recesses or each of the cutouts so as to fit along the inner surface of each of the recesses or each of the cutouts, and then forming the wavelength conversion layer so as to fill each of the recesses or each of the cutouts.

21. A method for manufacturing a light-emitting device as described in claim 19, comprising forming the plurality of light-emitting elements in a mesa shape with the first conductivity type semiconductor layer side as an apex on the semiconductor substrate, forming a reflective layer that is continuous from a portion facing the apex of the mesa shape to a portion of a side surface of the mesa shape that faces a side surface of the wavelength conversion layer, and further forming the wiring layer to form the light-emitting substrate.

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