Light emitting device and image display device

Abstract

A light-emitting device according to one embodiment of the present disclosure is provided with a drive substrate; a compound semiconductor layer having a first surface opposite to the drive substrate and a second surface on the opposite side of the first surface, and in which a first-conductivity-type layer, an active layer, and a second-conductivity-type layer are sequentially stacked from the drive substrate side; a first separation groove formed from the first surface side and separating the first-conductivity-type layer and the active layer for each pixel; a second separation groove formed from the second surface side at a position opposite to the first separation groove and separating a part of the second-conductivity-type layer for each pixel; and a first metal film provided along the side surface and the bottom surface of the second separation groove and having light reflectivity.

Description

Technical Field

[0001] This disclosure relates to light-emitting devices and image display devices including light-emitting devices. Background Technology

[0002] For example, Patent Document 1 discloses that crosstalk can be suppressed by providing light reflection trenches on the surface of a semiconductor layer between adjacent light-emitting parts in a semiconductor light-emitting device for a headlight.

[0003] Reference List

[0004] Patent documents

[0005] PTL 1: Japanese Patent Application Publication No. 2015-156431 Summary of the Invention

[0006] In addition, regarding light-emitting devices including micro LEDs (light-emitting diodes), it is desirable to reduce the pitch size and suppress crosstalk.

[0007] It is desirable to provide a light-emitting device that can reduce the pitch size and suppress crosstalk, and an image display device including the light-emitting device.

[0008] The light-emitting device according to an embodiment of the present disclosure includes a driving substrate, a compound semiconductor layer, a first separation trench, a second separation trench, and a first metal film. The compound semiconductor layer includes a first surface opposite to the driving substrate and a second surface located on the opposite side of the first surface. The compound semiconductor layer includes a first conductivity layer, an active layer, and a second conductivity layer stacked sequentially from the driving substrate side. The first separation trench is disposed from the first surface side and separates the first conductivity layer and the active layer for each pixel. The second separation trench is disposed from the second surface side at a position opposite to the first separation trench. The second separation trench separates a portion of the second conductivity layer for each pixel. The first metal film is disposed along the side and bottom surfaces of the second separation trench and has light reflectivity.

[0009] The image display device according to the embodiments of the present disclosure includes a light-emitting device, and includes the light-emitting device described above according to the embodiments of the present disclosure as a light-emitting device.

[0010] In each of the light-emitting device according to an embodiment of the present disclosure and the image display device according to an embodiment of the present disclosure: a first separation trench is formed from a first surface side of the compound semiconductor layer opposite to the driving substrate; a second separation trench is provided from a second surface side of the compound semiconductor layer opposite to the first surface side; and a light-reflective metal film is provided along the side and bottom surfaces of the second separation trench. This reduces stray light, light leakage to adjacent pixels, etc. Attached Figure Description

[0011] [Figure 1 ] Figure 1 This is a schematic cross-sectional view showing a construction example of a light-emitting device according to an embodiment of the present disclosure.

[0012] [ Figure 2 ] Figure 2 It is shown Figure 1 A schematic diagram illustrating an example of the overall planar structure of the light-emitting device.

[0013] [ Figure 3 ] Figure 3 It is magnification Figure 2 A schematic diagram of a portion of the planar structure of the light-emitting device shown.

[0014] [ Figure 4 ] Figure 4 It is magnified Figure 1 A schematic diagram of a portion of the cross-sectional structure of the light-emitting part.

[0015] [ Figure 5A ] Figure 5A It is shown Figure 1 A schematic cross-sectional view of an example of the manufacturing process of the light-emitting device shown.

[0016] [ Figure 5B ] Figure 5B It is shown Figure 5A A schematic cross-sectional view of the process following the first process.

[0017] [ Figure 5C ] Figure 5C It is shown Figure 5B A schematic cross-sectional view of the process following the first process.

[0018] [ Figure 5D ] Figure 5D It is shown Figure 5C A schematic cross-sectional view of the process following the first process.

[0019] [ Figure 5E ] Figure 5E It is shown Figure 5D A schematic cross-sectional view of the process following the first process.

[0020] [ Figure 5F ] Figure 5F It is shown Figure 5E A schematic cross-sectional view of the process following the first process.

[0021] [ Figure 5G ] Figure 5G It is shown Figure 5F A schematic cross-sectional view of the process following the first process.

[0022] [ Figure 5H ] Figure 5H It is shown Figure 5G A schematic cross-sectional view of the process following the first process.

[0023] [ Figure 5I ] Figure 5I It is shown Figure 5H A schematic cross-sectional view of the process following the first process.

[0024] [ Figure 6A ] Figure 6A It is shown Figure 5I A schematic cross-sectional view of the process following the first process.

[0025] [ Figure 6B ] Figure 6B It is shown Figure 6A A schematic cross-sectional view of the process following the first process.

[0026] [ Figure 6C ] Figure 6C It is shown Figure 6B A schematic cross-sectional view of the process following the first process.

[0027] [ Figure 6D ] Figure 6D It is shown Figure 6C A schematic cross-sectional view of the process following the first process.

[0028] [ Figure 6E ] Figure 6E It is shown Figure 6D A schematic cross-sectional view of the process following the first process.

[0029] [ Figure 6F ] Figure 6F It is shown Figure 6E A schematic cross-sectional view of the process following the first process.

[0030] [ Figure 6G ] Figure 6G It is shown Figure 6F A schematic cross-sectional view of the process following the first process.

[0031] [ Figure 6H ] Figure 6H It is shown Figure 6G A schematic cross-sectional view of the process following the first process.

[0032] [ Figure 6I ] Figure 6I It shows that following Figure 6H A schematic cross-sectional view of the process.

[0033] [ Figure 6J ] Figure 6J It is shown Figure 6I A schematic cross-sectional view of the process following the first process.

[0034] [ Figure 6K ] Figure 6K It is shown Figure 6J A schematic cross-sectional view of the process following the first process.

[0035] [ Figure 6L ] Figure 6L It is shown Figure 6K A schematic cross-sectional view of the process following the first process.

[0036] [ Figure 6M ] Figure 6M It is shown Figure 6L A schematic cross-sectional view of the process following the first process.

[0037] [ Figure 6N ] Figure 6N It is shown Figure 6M A schematic cross-sectional view of the process following the first process.

[0038] [ Figure 6O ] Figure 6O It is shown Figure 6N A schematic cross-sectional view of the process following the first process.

[0039] [ Figure 6P ] Figure 6P It is shown Figure 6O A schematic cross-sectional view of the process following the first process.

[0040] [ Figure 6Q ] Figure 6Q It is shown Figure 6P A schematic cross-sectional view of the process following the first process.

[0041] [ Figure 6R ] Figure 6R It is shown Figure 6Q A schematic cross-sectional view of the process following the first process.

[0042] [ Figure 6S ] Figure 6S It is shown Figure 6R A schematic cross-sectional view of the process following the first process.

[0043] [ Figure 6T ] Figure 6T It is shown Figure 6S A schematic cross-sectional view of the process following the first process.

[0044] [ Figure 7 ] Figure 7 This is a schematic cross-sectional view showing a construction example of a conventional light-emitting device.

[0045] [ Figure 8 ] Figure 8 This is a schematic cross-sectional view of a variation of this disclosure, Example 1.

[0046] [ Figure 9 ] Figure 9 This is a schematic cross-sectional view of a variation of this disclosure, Example 2.

[0047] [ Figure 10 ] Figure 10 This is a schematic cross-sectional view of variation 3 of this disclosure.

[0048] [ Figure 11 ] Figure 11 This is a schematic cross-sectional view of variation 4 of this disclosure.

[0049] [ Figure 12 ] Figure 12 This is a schematic cross-sectional view of variation 5 of this disclosure.

[0050] [ Figure 13 ] Figure 13 This is a schematic cross-sectional view of variation 6 of this disclosure.

[0051] [ Figure 14 ] Figure 14 This is a schematic cross-sectional view of variation 7 of this disclosure.

[0052] [ Figure 15 ] Figure 15 This is a schematic cross-sectional view of variation 8 of this disclosure.

[0053] [ Figure 16 ] Figure 16 This is a schematic cross-sectional view of variation 9 of this disclosure.

[0054] [ Figure 17 ] Figure 17 This is a schematic cross-sectional view of a variation of this disclosure, Example 10.

[0055] [ Figure 18 ] Figure 18 This is a schematic diagram illustrating an example of the planar layout of the metal film and pad electrodes of the light-emitting device according to the present disclosure.

[0056] [ Figure 19 ] Figure 19 This is a schematic diagram illustrating another example of the planar layout of the metal film and pad electrodes of the light-emitting device according to the present disclosure.

[0057] [ Figure 20 ] Figure 20 This is a schematic diagram illustrating another example of the planar layout of the metal film and pad electrodes of the light-emitting device according to the present disclosure.

[0058] [ Figure 21 ] Figure 21 This is a schematic diagram illustrating an example of the planar layout of the metal film of the light-emitting device according to the present disclosure.

[0059] [ Figure 22 ] Figure 22 This is a schematic diagram illustrating another example of the planar layout of the metal film of the light-emitting device according to the present disclosure.

[0060] [ Figure 23 ] Figure 23 This is a perspective view showing a construction example of an image display device according to an application example of the present disclosure.

[0061] [ Figure 24 ] Figure 24 It is shown Figure 23 The diagram shows an example of the wiring layout of an image display device.

[0062] [ Figure 25 ] Figure 25 This is a perspective view showing a construction example of an image display device according to an application example of the present disclosure.

[0063] [ Figure 26 ] Figure 26 It is shown Figure 25 The diagram shows a three-dimensional view of the structure of the mounting substrate.

[0064] [ Figure 27 ] Figure 27 It is shown Figure 26 The diagram shows a three-dimensional view of the structure of the unit substrate.

[0065] [ Figure 28 ] Figure 28 This is a diagram illustrating an example of an image display device according to an application example of the present disclosure. Detailed Implementation

[0066] In the following, one embodiment of the present disclosure is described in detail with reference to the accompanying drawings. Specific embodiments of the present disclosure are described below, and the present disclosure is not limited to these embodiments. Furthermore, the present disclosure is not limited to, for example, the arrangement, dimensions, aspect ratios, etc., of the components shown in each drawing. It should be noted that the description is given in the following order.

[0067] 1. Embodiment (Example of a light-emitting device in which a light-reflecting film is provided on the side and bottom surfaces of a trench provided on the light-emitting surface side of a compound semiconductor layer)

[0068] 1-1. Structure of the light-emitting device

[0069] 1-2. Manufacturing method of light-emitting device

[0070] 1-3. Functions and Effects

[0071] 2. Variations

[0072] 2-1. Variation Example 1 (Another example of a light-emitting device)

[0073] 2-2. Variation Example 2 (Another example of a light-emitting device)

[0074] 2-3. Variation Example 3 (Another example of a light-emitting device)

[0075] 2-4. Variation Example 4 (Another example of a light-emitting device)

[0076] 2-5. Variation 5 (Another example of a light-emitting device)

[0077] 2-6. Variation 6 (Another example of a light-emitting device)

[0078] 2-7. Variation 7 (Another example of a light-emitting device)

[0079] 2-8. Variation 8 (Another example of a light-emitting device)

[0080] 2-9. Variation 9 (Another example of a light-emitting device)

[0081] 2-10. Variation 10 (Another example of a light-emitting device)

[0082] 2-11. Variation 11 (Another example of a light-emitting device)

[0083] 2-12. Variation 12 (Another example of a light-emitting device)

[0084] 3. Application Examples (Examples of Image Display Devices)

[0085] <1. Implementation Method>

[0086] Figure 1 An example of the cross-sectional structure of a light-emitting device (light-emitting device 1) according to an embodiment of the present disclosure is shown schematically. Figure 2 Schematic illustration Figure 1 An example of the overall planar construction of the light-emitting device 1 shown. The light-emitting device 1 is advantageously suited for image display devices known as LED displays (e.g., described later). Figure 23 The image display device 100 shown.

[0087] [1-1. Structure of the light-emitting device]

[0088] The light-emitting device 1 includes: a display section 100A, wherein a plurality of pixels (e.g., red pixel Pr, green pixel Pg, and blue pixel Pb) are arranged in a two-dimensional array; and a frame section 100B disposed around the display section 100A. The light-emitting device 1 includes, for example, a light-emitting section 10 and a wavelength conversion section 20, which are sequentially stacked in the display section 100A on the surface 30S1 side of a driving substrate 30 including a front surface (surface 30S1) and a rear surface (surface 30S2) opposite to each other. The light-emitting section 10 includes a compound semiconductor layer 11.

[0089] The light-emitting device 1 includes a compound semiconductor layer 11, which includes a surface 11S1 opposite to the driving substrate 30 and a surface 11S2 on the opposite side of the surface 11S1. It also includes a first conductivity layer 111, an active layer 112, and a second conductivity layer 113 stacked sequentially from the driving substrate 30 side. The light-emitting device 1 has a trench 11U1 formed from the surface 11S1 side, which separates the first conductivity layer 111 and the active layer 112 for each pixel (e.g., red pixel Pr, green pixel Pg, blue pixel Pb). In the light-emitting device 1, a trench 11U2 is provided from the surface 11S2 side at a position opposite to the trench 11U1, which separates a portion of the second conductivity layer 113 for each pixel (e.g., red pixel Pr, green pixel Pg, blue pixel Pb). The light-emitting device 1 includes a light-reflective metal film 114 disposed along the side and bottom surfaces of the trench 11U2.

[0090] Here, surface 11S1 corresponds to a specific example of a "first surface" in one embodiment of this disclosure, and surface 11S2 corresponds to a specific example of a "second surface" in one embodiment of this disclosure. Trench 11U1 corresponds to a specific example of a "first separation trench" in one embodiment of this disclosure, and trench 11U2 corresponds to a specific example of a "second separation trench" in one embodiment of this disclosure. Metal film 114 corresponds to a specific example of a "first metal film" in one embodiment of this disclosure.

[0091] As described above, the light-emitting portion 10 includes a plurality of pixels (e.g., red pixel Pr, green pixel Pg, and blue pixel Pb) arranged in a two-dimensional array in the display portion 100A. Specifically, the plurality of pixels each have a generally hexagonal planar shape and are arranged, for example, in a honeycomb pattern, such as... Figure 3As shown. Electrode layer 121, insulating layer 122, protective layer 123, metal film 124, and embedding layer 125 are disposed on the surface 11S1 side of compound semiconductor layer 11. Electrode layer 121 and insulating layer 122 are disposed for each pixel. Protective layer 123 and metal film 124 are continuous between pixels. Embedding layer 125 allows pixels to be embedded therein. In addition, plug 13, insulating layer 15, and insulating layer 16 are disposed sequentially on the surface 11S1 side. Plug 13 is disposed for each pixel. Insulating layer 15 includes pad portion 14A, pad electrode 14B1, and pad electrode 14B2. Insulating layer 16 includes pad portion 17 that electrically and physically connects the light-emitting part 10 and the driving substrate 30 to each other.

[0092] The compound semiconductor layer 11 is a solid-state light-emitting element that emits light of a predetermined wavelength band from its surface 11S1. For example, the compound semiconductor layer 11 is an LED chip. An LED chip refers to an LED chip in its state of being cut from a wafer used for crystal growth, and does not refer to an LED chip encapsulated with, for example, molding resin. For example, an LED chip has a size greater than or equal to 5 μm and less than or equal to 100 μm, and is a so-called micro LED.

[0093] The compound semiconductor layer 11 includes a surface 11S1 opposite to the driving substrate 30 and a surface 11S2 on the opposite side of surface 11S1, and includes a first conductivity layer 111, an active layer 112, and a second conductivity layer 113 stacked sequentially from the driving substrate 30 side. An undoped layer 115 and a buffer layer 116 are stacked sequentially on the second conductivity layer 113. The undoped layer 115 corresponds to a specific example of an "undoped semiconductor layer" in one embodiment of the present disclosure, and the buffer layer 116 corresponds to a specific example of a "buffer layer" in one embodiment of the present disclosure.

[0094] The first conductivity layer 111 comprises, for example, an n-type GaN-based semiconductor material. The active layer 112 has, for example, a multi-quantum-well structure with alternating stacks of InGaN and GaN. The active layer 112 has a light-emitting region. For example, light in the blue light band greater than or equal to 430 nm and less than or equal to 500 nm can be extracted from the active layer 112. For example, light with a wavelength corresponding to the ultraviolet region (ultraviolet light) can be extracted from the active layer 112. The second conductivity layer 113 comprises, for example, a p-type GaN-based semiconductor material.

[0095] Figure 4 Enlarged and schematically shown Figure 1 A partial cross-section of the light-emitting part 10 of the light-emitting device 1 shown.

[0096] Trench 11U1 is formed from the surface 11S1 side, and a first conductive layer 111 and an active layer 112 are separated for each pixel (e.g., red pixel Pr, green pixel Pg, and blue pixel Pb). For example, the width W1 of the bottom surface of trench 11U1 is greater than the width W2 of the bottom surface of trench 11U2, and the angle (θ1) formed by the side surface and bottom surface of trench 11U1 is greater than a positive cone shape of 90 degrees. In trench 11U1, a protective layer 123 is configured to cover the side surface and bottom surface of trench 11U1. In addition, in trench 11U1, a metal film 124 is formed on the protective layer 123 in the same manner as the protective layer 123.

[0097] Trench 11U2 is disposed from the surface 11S2 side at a position opposite to trench 11U1, and for each pixel (e.g., red pixel Pr, green pixel Pg, and blue pixel Pb), a portion of undoped layer 115, buffer layer 116, and second conductivity layer 113 are separated. That is, the second conductivity layer 113 is continuous between pixels. For example, the sides of trench 11U2 are inclined. Specifically, trench 11U2 has, for example, a positive cone shape with an angle (θ1) greater than 90 degrees formed by the sides and bottom of trench 11U2. In trench 11U2, metal film 114 is disposed on the sides and bottom of trench 11U2. This allows light emitted from active layer 112 in an inclined direction (emitted light L) to be reflected by metal film 114, and thus reduces light entering wavelength conversion layers 23 (e.g., red wavelength conversion layer 23R, green wavelength conversion layer 23G, or blue wavelength conversion layer 23B) disposed in adjacent pixels. In addition, the trench 11U2 is filled with a planarization layer 21, which will be described later.

[0098] The metal film 114 is disposed along the sides and bottom of the groove 11U2. For example... Figure 3 As shown in the top view, a metal film 114 is disposed on the entire display unit 100A, and has an opening 114H for each pixel (e.g., red pixel Pr, green pixel Pg, and blue pixel Pb). The surface 11S2 of the compound semiconductor layer 11 is exposed in the opening 114H. This allows light emitted from the active layer 112 to be extracted to the light emitting surface S1 side. Furthermore, the metal film 114 extends to the frame portion 100B and is connected to a pad electrode 14B1 exposed at the bottom of the opening H1 (described later). The pad electrode 14B1 is electrically connected to the driving substrate 30. That is, the metal film 114 also serves as wiring to electrically connect the driving substrate 30 and the second conductivity layer 113 to each other. The metal film 114 comprises a light-reflective metallic material. Examples of light-reflective metallic materials include aluminum (Al) and silver (Ag). For example, aluminum (Al), silver (Ag), or both are used to form the metal film 114.

[0099] An undoped layer 115 is disposed on the second conductivity layer 113 and includes, for example, an undoped GaN-based semiconductor material.

[0100] A buffer layer 116 is disposed on the undoped layer 115 and includes, for example, a GaN-based semiconductor material grown at low temperature.

[0101] The electrode layer 121 is configured to contact the surface 11S1 of the compound semiconductor layer 11. The electrode layer 121 is in ohmic contact with the first conductivity layer 111 and is formed, for example, using a multilayer film of nickel (Ni) and gold (Au) (Ni / Au), a transparent conductive material such as ITO, etc.

[0102] An insulating layer 122 is disposed on the side of the electrode layer 121 opposite to the surface of the electrode layer 121 that contacts the surface 11S1. The insulating layer 122 is formed using, for example, silicon oxide (SiO) or silicon nitride (SiN).

[0103] The protective layer 123 is continuously disposed along the side and bottom surfaces of the trench 11U1 and the surface of the insulating layer 122 opposite to the drive substrate 30, and extends to the frame portion 100B. The protective layer 123 is formed using, for example, silicon oxide (SiO) or silicon nitride (SiN).

[0104] The metal film 124 comprises a light-reflective metallic material disposed along the sides and bottom of the trench 11U1. The metal film 124 comprises, for example, aluminum (Al), silver (Ag), or both. Here, the metal film 124 corresponds to a specific example of a "second metal film" in one embodiment of this disclosure.

[0105] The embedding layer 125 is configured to planarize the surface of the light-emitting portion 10 opposite to the driving substrate 30. The embedding layer 125 is formed using, for example, silicon oxide (SiO) or silicon nitride (SiN).

[0106] The plug 13 is configured to apply, for example, an anode voltage to a first conductive layer 111 separated by trench 11U1 for each pixel. The plug 13 is formed using, for example, copper (Cu), aluminum (Al), tungsten (W), silver (Ag), or any alloy thereof.

[0107] The insulating layer 15 includes a plurality of pad portions 14A and vias in the display portion 100A. Each pad portion 14A and via is provided for a corresponding pixel (e.g., red pixel Pr, green pixel Pg, and blue pixel Pb). For example, the pad portions 14A and vias are formed using copper (Cu), aluminum (Al), tungsten (W), silver (Ag), or any alloy thereof.

[0108] Furthermore, pad electrodes 14B1, 14B2, and vias are disposed in the insulating layer 15 within the frame portion 100B. Pad electrode 14B1 serves as a cathode terminal configured to apply a cathode voltage to the second conductive layer 113. Pad electrode 14B2 serves as an external connection terminal configured to connect the light-emitting device 1 to an external source. Each of pad electrodes 14B1 and 14B2 is formed using, for example, copper (Cu), aluminum (Al), tungsten (W), silver (Ag), or any alloy thereof.

[0109] The insulating layer 15 includes, for example, silicon oxide (SiO) and silicon nitride (SiN).

[0110] Furthermore, an insulating layer 16 and pad portions 17 embedded in the insulating layer 16 are provided on the driving substrate 30 side of the insulating layer 15. The insulating layer 16 forms a bonding surface for bonding the driving substrate 30. The insulating layer 16 includes, for example, silicon oxide (SiO) or silicon nitride (SiN). The pad portions 17 are formed, for example, using copper (Cu).

[0111] A wavelength conversion unit 20 is disposed on the light emitting surface S1 side of the light-emitting unit 10. The wavelength conversion unit 20 includes a planarization layer 21, a partition layer 22, and a wavelength conversion layer 23. The partition layer 22 has an opening 22H for each pixel (e.g., red pixel Pr, green pixel Pg, and blue pixel Pb). The wavelength conversion layer 23 is disposed within the opening 22H. Furthermore, a reflective film 24 is disposed between the partition layer 22 and the wavelength conversion layer 23. Additionally, a protective layer 25 is disposed on the light emitting surface S1 side of the wavelength conversion layer 23, and a light reflective film 26 and a light absorption film 27 are disposed within the protective layer 25. Furthermore, an on-chip lens layer 28 is disposed on the protective layer 25.

[0112] The planarization layer 21 is configured to planarize the surface of the compound semiconductor layer 11 on the surface 11S1 side. The planarization layer 21 includes, for example, silicon oxide (SiO), silicon nitride (SiN), etc.

[0113] The partition layer 22 is configured to suppress color mixing caused by light leakage between adjacent pixels, including red pixel Pr, green pixel Pg, and blue pixel Pb. The partition layer 22, like the pixels (e.g., red pixel Pr, green pixel Pg, blue pixel Pb), has, for example, a honeycomb structure. Specifically, like the metal film 114, each of the plurality of pixels (red pixel Pr, green pixel Pg, blue pixel Pb) arranged in an array has a generally hexagonal opening 22H (e.g., see reference 114). Figure 6QIn the cross-sectional view, the opening 22H has an inclined surface with an angle of less than 90° relative to the surface 20S2 of the wavelength conversion section 20 on the side opposite to the surface 20S1. That is, in the cross-sectional view, the partition layer 22 has a positive cone shape between adjacent red pixels Pr, green pixels Pg, and blue pixels Pb. The partition layer 22 is preferably formed using a material with high thermal conductivity and high electrical conductivity. The partition layer 22 is formed using a metallic material such as copper (Cu), aluminum (Al), gold (Au), nickel (Ni), or platinum (Pt).

[0114] A wavelength conversion layer 23 is disposed above the surface 11S2 of the compound semiconductor layer 11 and converts light emitted from the active layer 112, which is separated through the trench 11U1 for each pixel (e.g., red pixel Pr, green pixel Pg, and blue pixel Pb), into light of a predetermined wavelength band (e.g., red (R), green (G), or blue (B)). Specifically, the red pixel Pr is provided with a red wavelength conversion layer 23R, which converts light emitted from the active layer 112 into light within the red band (red light); the green pixel Pg is provided with a green wavelength conversion layer 23G, which converts light emitted from the active layer 112 into light within the green band (green light); and the blue pixel Pb is provided with a blue wavelength conversion layer 23B, which converts light emitted from the active layer 112 into light within the blue band (blue light).

[0115] Each of the wavelength conversion layers 23R, 23G, and 23B can be formed using quantum dots, for example, corresponding to each color. Specifically, when obtaining red light, the quantum dots can be selected from, for example, InP, GaInP, InAsP, CdSe, CdZnSe, CdTeSe, CdTe, etc. When obtaining green light, the quantum dots can be selected from, for example, InP, GaInP, ZnSeTe, ZnTe, CdSe, CdZnSe, CdS, CdSeS, etc. When obtaining blue light, the quantum dots can be selected from, for example, ZnSe, ZnTe, ZnSeTe, CdSe, CdZnSe, CdS, CdZnS, CdSeS, etc.

[0116] It should be noted that, in the case where blue light is emitted from the active layer 112 as described above, the blue wavelength conversion layer 23B may include a light-transmitting resin layer. That is, the blue pixel Pb may be provided with a light-transmitting resin layer as the wavelength conversion layer 23B, and the light in the blue pixel Pb has a wavelength band that is substantially the same as the wavelength band of the light emitted from the active layer 112. Wavelength conversion layers 23R and 23G, respectively, comprising the aforementioned quantum dots, are provided in the red pixel Pr and green pixel Pg, which have wavelength bands different from the wavelength band of the light emitted from the active layer 112.

[0117] Here, the blue pixel Pb corresponds to a specific example of a "first pixel" in one embodiment of this disclosure. The red pixel Pr and the green pixel Pg both correspond to a specific example of a "second pixel" in one embodiment of this disclosure. Wavelength conversion layers 23R and 23G both correspond to a specific example of a "wavelength conversion layer disposed in the first pixel" in one embodiment of this disclosure, and the quantum dot corresponds to a specific example of a "color conversion material" in one embodiment of this disclosure. Wavelength conversion layer 23B corresponds to a specific example of a "wavelength conversion layer disposed in the second pixel" in one embodiment of this disclosure.

[0118] The reflective film 24 is configured to allow light of each color emitted from the active layer 112 and converted in one of the corresponding wavelength conversion layers 23R, 23G, and 23B to be effectively extracted from the surface 22S1 of the wavelength conversion layer 23. The reflective film 24 is disposed on the side of the opening 22H. The reflective film 24 is formed of a metallic material with light reflectivity. Examples of metallic layers included in the reflective film 24 include metals with high reflectivity in the visible light region. Examples of specific materials include silver (Ag), aluminum (Al), copper (Cu), gold (Au), platinum (Pt), rhodium (Rh), and alloys thereof.

[0119] It should be noted that if the partition layer 22 is formed using a metallic material with the aforementioned light reflectivity, it is not necessarily necessary to install a reflective film 24.

[0120] The protective layer 25 is configured to protect the surface of the light-emitting device 1 and is formed using, for example, silicon oxide (SiO) or silicon nitride (SiN).

[0121] A light-reflecting film 26 is disposed within the protective layer 25, spanning the red pixel Pr and the green pixel Pg. The light-reflecting film 26 selectively reflects light of a predetermined wavelength band. For example, the light-reflecting film 26 selectively reflects blue light (blue light) and is disposed above wavelength conversion layers 23R and 23G respectively disposed in the red pixel Pr and the green pixel Pg. This improves the color purity of the red and green light extracted from the red pixel Pr and the green pixel Pg, respectively. The light-reflecting film 26 is, for example, a DBR (Distributed Bragg reflector).

[0122] The light-absorbing film 27 selectively absorbs light of a predetermined wavelength band and is disposed, for example, on the light-reflecting film 26 in the protective layer 25. For example, the light-absorbing film 27 selectively absorbs light in the blue light band (blue light) and is disposed, for example, above the wavelength conversion layers 23R and 23G disposed in the red pixel Pr and green pixel Pg, respectively. As a result, the color purity of the red light and green light extracted from the red pixel Pr and green pixel Pg, respectively, is improved. The light-absorbing film 27 is, for example, a color filter.

[0123] An on-chip lens layer 28 is disposed above the protective layer 25. The on-chip lens layer 28 includes a light-transmitting material and includes, for example, a single-layer film of one of silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiCN), etc., or a stacked film including two or more of them. Here, the on-chip lens layer 28 corresponds to a specific example of a "lens" in one embodiment of this disclosure.

[0124] The frame portion 100B has an opening H1 extending through the embedded layer 125 and the protective layer 123 and reaching the pad electrode 14B1. A metal film 114 extending from the display portion 100A is disposed on the side and bottom surfaces of the opening H1. Therefore, the second conductive layer 113 and the driving substrate 30 are electrically connected to each other.

[0125] In addition, the frame portion 100B has an opening H2 that extends through the on-chip lens layer 28, the protective layer 25, the partition layer 22, the planarization layer 21, the embedding layer 125 and the protective layer 123, and reaches the pad electrode 14B2.

[0126] The driving substrate 30 is provided with driving circuitry for controlling the driving of multiple pixels arranged in the display unit 100A. The driving substrate 30 includes, for example, a support substrate 31, an interlayer insulating layer 32, an insulating layer 33, and pad portions 34. The support substrate 31 is made of silicon (Si). The interlayer insulating layer 32 is disposed on the support substrate 31 and includes multiple wiring layers (e.g., wiring layers M1, M2, M3, M4, and M5) and vias electrically connecting the wiring layers to each other. The insulating layer 33 forms a bonding surface connecting to the light-emitting unit 10. The pad portions 34 are embedded in the insulating layer 33.

[0127] For example, silicon oxide (SiO), silicon nitride (SiN), etc. are used to form an interlayer insulating layer 32.

[0128] Wiring layers M1, M2, M3, M4, and M5, as well as vias electrically connecting the wiring layers, are formed using materials such as copper (Cu), aluminum (Al), tungsten (W), silver (Ag), and any alloys thereof. Insulating layer 33 includes, for example, silicon oxide (SiO) and silicon nitride (SiN). Pad portion 35 is formed, for example, using copper (Cu).

[0129] [1-2. Manufacturing method of light-emitting device]

[0130] For example, the light-emitting device 1 according to this embodiment can be manufactured as follows. Figures 5A to 5I as well as Figure 6A Figures 6 through 6U show examples of the manufacturing process of the light-emitting device 1.

[0131] First, such as Figure 5AAs shown, a compound semiconductor layer 11 is formed on a growth substrate 41, such as a silicon substrate, for example, by epitaxial crystal growth using methods such as metal-organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE). Then, an electrode layer 121 and an insulating layer 122 are formed on the compound semiconductor layer 11, for example, by chemical vapor deposition (CVD). Next, the surface of the insulating layer 122 is planarized, for example, by chemical mechanical polishing (CMP).

[0132] Next, as Figure 5B As shown, for example, the insulating layer 122, electrode layer 121, and compound semiconductor layer 11 are etched and patterned using photolithography. Next, as... Figure 5C As shown, the growth substrate 41 is transferred onto a support substrate 51, such as a silicon substrate, to allow the insulating layer 122 to face the support substrate 51, after which the growth substrate 41 is diced into individual wafers. Next, as... Figure 5D As shown, the monolithized growth substrate 41 is bonded to the support substrate 52 to allow the insulating layer 122 to face the support substrate 52.

[0133] Next, as Figure 5E As shown, for example, the growth substrate 41 is removed by laser lift-off. Then, as... Figure 5F As shown, for example, a silicon nitride film is formed on the upper surface of the compound semiconductor layer 11, the side surface of the compound semiconductor layer 11, the side surface of the electrode layer 121, and the side surface of the insulating layer 122, and then an embedding layer 125 is formed on the support substrate 52.

[0134] Next, as Figure 5G As shown, the embedded layer 125 is planarized, and then the ends of the supporting substrate 52 are trimmed. Next, as... Figure 5H As shown, the embedded layer 125 is bonded to the support substrate 53, for example, via plasma bonding. Then, as... Figure 5I As shown, the support substrate 52 is peeled off. Refer to the following... Figure 5I The enlarged portion of box X shown in the diagram is explained.

[0135] First, such as Figure 6A As shown, for example, the insulating layer 122 and the electrode layer 121 are etched and patterned using photolithography. Then, as... Figure 6B As shown, for example, a trench 11U1 is formed by using photolithography to separate the first conductive layer 111 from the active layer 112.

[0136] Next, as Figure 6C As shown, for example, a SiN film is deposited along the upper surface of the insulating layer 122 and the sides and bottom of the trench 11U1 using an atomic layer deposition (ALD) method to form a protective layer 123. Next, as... Figure 6DAs shown, for example, a metal film 124 is formed using a CVD method, and then an opening 124H is formed for each pixel. Then, as... Figure 6E As shown, for example, an embedding layer 125 is formed by a CVD method, in which the trench 11U1 is embedded again and the surface is planarized.

[0137] Next, as Figure 6F As shown, an insulating layer 15 is formed, in which plugs 13 for each pixel and a plurality of pad portions 14A are embedded, and pad electrodes 14B1 and pad electrodes 14B2 are embedded. Next, as... Figure 6G As shown, the film thickness of insulating layer 15 is increased, and insulating layer 16 is formed on insulating layer 15. Then, as... Figure 6H As shown, trim the ends.

[0138] Next, as Figure 6I As shown, openings 16H extending through insulating layers 16 and 15 are formed on each pad portion 14A, pad electrode 14B1, and pad electrode 14B2. Next, as... Figure 6J As shown, the opening 16H is filled with, for example, Cu to form a plurality of pad portions 17. Next, as... Figure 6K As shown, for example, the surfaces of the insulating layer 16 and the plurality of pad portions 17 are polished by CMP to planarize the bonding surfaces of the connecting drive substrate 30, and then the plurality of pad portions 34 and the plurality of pad portions 17 of the separately formed drive substrate 30 are bonded to each other by Cu-Cu bonding.

[0139] Next, as Figure 6L As shown, the support substrate 53 is peeled off. Next, as... Figure 6M As shown, for example, the embedded layer 125 is polished by CMP to expose the compound semiconductor layer 11. Then, as... Figure 6N As shown, for example, a hard mask HM is patterned on the surfaces of the compound semiconductor layer 11 and the embedding layer 125 using photolithography. Then, as... Figure 6O As shown, for example, a trench 11U2 is formed by using photolithography to separate a portion of the undoped layer 115, the buffer layer 116, and the second conductivity layer 113. Then, an opening H1 leading to the pad electrode 14B1 is formed in the frame portion 100B through a similar process.

[0140] Next, as Figure 6P As shown, the hard mask HM is removed, and then a metal film 114 is formed on all surfaces of the compound semiconductor layer 11 and the embedded layer 125, including the side and bottom surfaces of the trench 11U2 and the side and bottom surfaces of the opening H1, for example, by a CVD method. Next, the metal film 114 is patterned to form an opening 114H on the surface 11S2 of the compound semiconductor layer 11.

[0141] Next, as Figure 6Q As shown, for example, a planarization layer 21 and a partition layer 22 are formed sequentially using a CVD method, and then, for example, an opening 22H is formed in the partition layer 22 at the top of each pixel using a photolithography technique. Next, as... Figure 6R As shown, for example, an Al film is formed on the upper surface of the partition layer 22 and the side and bottom surfaces of the opening 22H by a CVD method. Then, the Al film formed on the upper surface of the partition layer 22 and the bottom surface of the opening 22H is removed by etching back, and a reflective film 24 is formed on the side surface of the opening 22H.

[0142] Next, as Figure 6S As shown, wavelength conversion layers 23 (23R, 23G, or 23B) for each color are formed in the opening 22H, for example, by a coating method such as inkjet printing. Then, as... Figure 6T As shown, a protective layer 25, including a light-reflecting film 26 and a light-absorbing film 27, is formed on the partition layer 22 and the wavelength conversion layer 23, and then an on-chip lens layer 28 is bonded to it. This completes the process. Figure 1 The light-emitting device 1 shown.

[0143] [1-3. Functions and Effects]

[0144] In the light-emitting device 1 according to an embodiment of the present disclosure, trenches 11U1 and 11U2 are formed on both surfaces of a compound semiconductor layer 11 having a pair of opposing surfaces (surface 11S1 and surface 11S2) and having a first conductivity layer 111, an active layer 112, a second conductivity layer 113, an undoped semiconductor layer 115, and a buffer layer 116 stacked sequentially from the surface 11S1 side. The trenches 11U1 and 11U2 are positioned opposite each other, and a light-reflective metal film 114 is provided on the side and bottom surfaces of the trench 11U2, which is formed from the surface 11S2 side, which serves as the light extraction surface. This reduces stray light, light leakage, etc. Therefore, crosstalk between adjacent pixels (e.g., red pixel Pr, green pixel Pg, blue pixel Pb) can be suppressed.

[0145] Furthermore, in the light-emitting device 1, a metal film 118 is disposed on the side and bottom surfaces of the trench 11SU1 provided from the surface 11S1 side of the compound semiconductor layer 11. As a result, stray light or leakage light from adjacent pixels is reflected by the trenches 11U1 and 11U2. Therefore, crosstalk between adjacent pixels (e.g., red pixel Pr, green pixel Pg, blue pixel Pb) can be further suppressed.

[0146] Figure 7An example of a typical cross-sectional structure of a light-emitting device 1000 is schematically shown. In the light-emitting device 1000, for example, on the light-emitting surface side of a plurality of light-emitting elements 1100 arranged in a two-dimensional array, an electrode layer 1117 and an insulating layer 1118 are sequentially and continuously disposed on the plurality of light-emitting elements 1100. The electrode layer 1117 contains, for example, ITO. The insulating layer 1118 has an opening 1118H, and the electrode layer 1117 and the lead-out electrode 1119 are connected to each other through the opening 1118H. Therefore, in the light-emitting device 1000, a cathode voltage is applied to the second conductive layer 1113 of the light-emitting element 1100 through the lead-out electrode 1119 and the electrode layer 1117.

[0147] Conversely, in the light-emitting device 1 according to this embodiment, a metal film 114 disposed along the side and bottom surfaces of the trench 11U2 extending from the surface 11S2 side of the compound semiconductor layer 11 to the second conductive layer 113 serves as wiring to electrically connect the second conductive layer 113 and the driving substrate 30 to each other and to apply a cathode voltage to the second conductive layer 113. Compared to the light-emitting device 1000 which applies a cathode voltage to the second conductive layer 1113 via an electrode layer 1117 comprising a transparent conductive material such as ITO having relatively high resistance, this allows for a reduction in ohmic drop.

[0148] In addition, Figure 7 In the light-emitting device 1000 shown, as described above, an electrode layer 1117 for applying a cathode voltage is disposed on the second conductivity layer 1113. Therefore, in the light-emitting device 1000, after removing the growth substrate, it is necessary to reduce the film thickness of the compound semiconductor layer until the second conductivity layer 1113 is exposed.

[0149] Conversely, in the light-emitting device 1 according to this embodiment, a metal film 114, serving as wiring for applying a cathode voltage, is also provided along the side and bottom surfaces of the trench 11U2 extending from the surface 11S2 side of the compound semiconductor layer 11 to the second conductivity layer 113, as described above. This eliminates the need to reduce the film thickness of the compound semiconductor layer 11 after removing the growth substrate 41. Specifically, the process of removing the undoped layer 115 and the buffer layer 116 becomes unnecessary. Therefore, the manufacturing process can be simplified. Furthermore, the in-plane uniformity of the surface 11S1 side of the compound semiconductor layer 11 can be improved.

[0150] Next, variations 1 to 12 and application examples of this disclosure will be described. Furthermore, the descriptions of structural elements corresponding to the light-emitting device 1 in the above embodiments will be omitted.

[0151] <2. Variations>

[0152] [2-1. Variation Example 1]

[0153] Figure 8 An example of the cross-sectional structure of a light-emitting device (light-emitting device 1A) according to a variation of this disclosure is shown schematically.

[0154] The light-emitting device 1A corresponds to the light-emitting device 1 according to the above embodiment, wherein the undoped layer 115 and the buffer layer 116 stacked on the second conductivity layer 113 are removed. Otherwise, the light-emitting device 1A has a structure that is substantially the same as that of the light-emitting device 1 according to the above embodiment.

[0155] The light-emitting device 1A can be manufactured using a method similar to that of the light-emitting device 1, up to the process of bonding the monolithized growth substrate 41 to the support substrate 52 to allow the insulating layer 122 to face the support substrate 52. In the light-emitting device 1A, after removing the growth substrate 41, the thickness of the compound semiconductor layer 11 is reduced, for example, by grinding and polishing, until the second conductivity layer 113 is exposed. Then, the light-emitting device 1A can be manufactured using a method similar to that of the light-emitting device 1.

[0156] In the light-emitting device 1A according to this modification, the undoped layer 115 and the buffer layer 116 stacked on the second conductivity layer 113 are removed. Therefore, the trench 11U2A formed from the surface 11S2 side of the compound semiconductor layer 11 separates only a portion of the second conductivity layer 113. Therefore, compared to the case where the undoped layer 115, the buffer layer 116, and a portion of the second conductivity layer 113 are separated as in the above embodiment, a trench 11U2A with a smaller size can be formed. Therefore, the pitch size and height of the light-emitting device can be reduced.

[0157] [2-2. Variation Example 2]

[0158] Figure 9 An example of the cross-sectional structure of a light-emitting device (light-emitting device 1B) according to a variation 2 of this disclosure is shown schematically.

[0159] In the light-emitting device 1B according to this modified example, as in modified example 1, the undoped layer 115 and the buffer layer 116 are removed. Furthermore, in the light-emitting device 1B according to this modified example, the groove 11U2 provided at the outer end of the display section 100A is omitted in the above embodiments, etc. Apart from these points, the light-emitting device 1B has a structure substantially the same as that of the light-emitting device 1 according to the above embodiment.

[0160] In the light-emitting device 1B according to this modification, the undoped layer 115 and the buffer layer 116 stacked on the second conductivity layer 113 are removed, and the second conductivity layer 113 extends from the outer edge of the display portion 100A to the frame portion 100B without forming the trench 11U2. Similarly, with this configuration, the light-emitting device 1B can achieve effects similar to those described in the above-described embodiment and modification 1.

[0161] [2-3. Variation Example 3]

[0162] Figure 10 An example of the cross-sectional structure of a light-emitting device (light-emitting device 1C) according to a variation 3 of this disclosure is shown schematically.

[0163] In the light-emitting device 1C, the groove 11U2 is filled with a metal film 114A. Apart from this, the light-emitting device 1C has a structure that is substantially the same as that of the light-emitting device 1 according to the above embodiment.

[0164] The metal film 114A is configured to fill the trench 11U2 and contains a light-reflective metallic material. Examples of light-reflective metallic materials include aluminum (Al), silver (Ag), etc. For example, aluminum (Al), silver (Ag), or both are used to form the metal film 114A.

[0165] In the light-emitting device 1C according to this modification, the trench 11U2 is filled with a metal film 114A. Therefore, compared with the case where only the thin metal film 114 is used to cover the sides and bottom of the trench 11U2, crosstalk between adjacent pixels (e.g., red pixel Pr, green pixel Pg, blue pixel Pb) can be further suppressed.

[0166] [2-4. Variation Example 4]

[0167] Figure 11 An example of the cross-sectional structure of a light-emitting device (light-emitting device 1D) according to a variation 4 of this disclosure is shown schematically.

[0168] In the light-emitting device 1D, an embedding layer 125 is inserted between the compound semiconductor layer 11 and the metal film 114 at the end of the compound semiconductor layer 11 extending in the frame portion 100B. Apart from this, the light-emitting device 1D has a structure that is substantially the same as that of the light-emitting device 1 of the above embodiment.

[0169] With this construction, the light-emitting device 1D can achieve an effect similar to that of the light-emitting device 1 according to the above embodiment.

[0170] [2-5. Variation Example 5]

[0171] Figure 12An example of the cross-sectional structure of a light-emitting device according to a variation 5 of this disclosure is shown schematically (light-emitting device 1E).

[0172] The above-described embodiment has referenced an example in which a metal film 114 is disposed in the frame portion 100B and continuously disposed to the opening H1, in which the pad electrode 14B1 serving as the cathode electrode is exposed at the bottom; however, this is not limiting. In the light-emitting device 1E according to this modified example, an opening H3 is provided that reaches the compound semiconductor layer 11 extending in the frame portion 100B. The metal film 114B is continuously disposed along the side and bottom surfaces of the opening H3 and the side and bottom surfaces of the opening H1 to electrically connect the second conductivity layer 113 and the driving substrate 30 to each other. Apart from this, the light-emitting device 1E has a substantially the same structure as the light-emitting device 1 of the above-described embodiment.

[0173] The metal film 114B electrically connects the driving substrate 30 and the second conductive layer 113 to each other. The metal film 114B is formed using materials such as aluminum copper (AlCu), copper (Cu), titanium (Ti), titanium nitride (TiN), tantalum (Ta), tantalum nitride (TaN), tungsten (W), and cobalt (Co).

[0174] In the light-emitting device 1E according to this modification, the connection with the pad electrode 14B1 exposed at the bottom of the opening H1 is achieved by a metal film 114B, which is different from the metal film 114. This increases the freedom to select the material of the metal film 114 for suppressing crosstalk and the material of the metal film 114B for electrically connecting the second conductivity layer 113 and the driving substrate 30 to each other.

[0175] [2-6. Variation Example 6]

[0176] Figure 13 An example of the cross-sectional structure of a light-emitting device (light-emitting device 1F) according to a variation 6 of this disclosure is shown schematically.

[0177] The above embodiment has referenced an example in which a metal film 114 disposed on the surface 11S2 side of the compound semiconductor layer 11 extends from the display portion 100A to the bottom of the opening H1 of the exposed pad electrode 14B1, and the second conductivity layer 113 is electrically connected to the driving substrate 30 through the metal film 114; however, this is not limiting. In the light-emitting device 1F according to this modified example, the second conductivity layer 113 and the driving substrate 30 are electrically connected to each other from the surface 11S1 side of the compound semiconductor layer 11. Specifically, the first conductivity layer 111 and the active layer are removed in the frame portion 100B to expose the second conductivity layer 113 on the surface 11S1 side. The plug 18 is connected to the second conductivity layer 113 exposed on the surface 11S2 side. The second conductivity layer 113 and the driving substrate 30 are thus electrically connected to each other. Apart from this, the light-emitting device 1E has a structure that is substantially the same as that of the light-emitting device 1 of the above embodiment.

[0178] In the light-emitting device 1F according to this modified example, the second conductive layer 113 and the driving substrate 30 are electrically connected to each other from the surface 11S1 side opposite to the surface 11S2 serving as the light extraction surface of the compound semiconductor layer 11 via a plug 18. Therefore, in addition to the effects of the above-described embodiment, the manufacturing process can be simplified by integrally forming the plug on the anode side and the cathode side.

[0179] [2-7. Variation Example 7]

[0180] Figure 14 An example of the cross-sectional structure of a light-emitting device (light-emitting device 1G) according to a variation 7 of this disclosure is shown schematically.

[0181] The embodiments have been described above with reference to an example in which the surface 11S2 of the compound semiconductor layer 11 is flat; however, this is not limiting. In the light-emitting device 1G according to this modification, the surface 11S2 of the compound semiconductor layer 11, which serves as the light emitting surface, is provided with an uneven structure. For example, as Figure 6O As shown, after forming the trench 11U2, an uneven structure is formed on the surface 11S2 of the compound semiconductor layer 11 during the process of removing the hard mask HM. Alternatively, the unevenness of the surface 11S2 of the compound semiconductor layer 11 can be formed by performing a surface treatment separately. Apart from this, the light-emitting device 1E has a substantially the same structure as the light-emitting device 1 of the above embodiment.

[0182] In the light-emitting device 1G according to this modified example, the surface 11S2 of the compound semiconductor layer 11, which serves as the light emitting surface, has an uneven shape. Therefore, in addition to the effects of the above-described embodiments, the light extraction efficiency can be improved.

[0183] [2-8. Variation Example 8]

[0184] Figure 15 An example of the cross-sectional structure of a light-emitting device (light-emitting device 1H) according to a variation 8 of this disclosure is shown schematically.

[0185] The light-emitting device 1H according to this modification has an opening H4 that extends through the on-sheet lens layer 28, the protective layer 25, and the partition layer 22 at a position corresponding to the opening H1, and separates a portion of the planarization layer 21. Apart from this, the light-emitting device 1H has a substantially the same structure as the light-emitting device 1 of the above embodiment.

[0186] [2-9. Variation Example 9]

[0187] Figure 16 This is an enlarged schematic diagram showing a portion of a planar structure example of a light-emitting device (light-emitting device 1I) according to a variation 9 of this disclosure.

[0188] In the above embodiments, an example was described where the planar shape of multiple pixels (e.g., red pixel Pr, green pixel Pg, and blue pixel Pb) is approximately hexagonal and arranged in a honeycomb pattern; however, this is not limiting. In the light-emitting device 1I of this modified example, multiple pixels (e.g., red pixel Pr, green pixel Pg, and blue pixel Pb) are formed into a approximately square planar shape and arranged in a grid pattern. Apart from this, the light-emitting device 1I has a structure substantially the same as that of the light-emitting device 1 of the above embodiments.

[0189] With this construction, the light-emitting device 1J can achieve an effect similar to that of the light-emitting device 1 according to the above embodiment.

[0190] [2-10. Variation Example 10]

[0191] Figure 17 This is an enlarged schematic diagram showing a portion of a planar structure example of a light-emitting device (light-emitting device 1J) according to a variation 10 of this disclosure.

[0192] In the above embodiments, an example was described where multiple pixels (e.g., red pixel Pr, green pixel Pg, and blue pixel Pb) are in a generally hexagonal planar shape and arranged in a honeycomb pattern; however, this is not limiting. In the light-emitting device 1J of this modified example, multiple pixels (e.g., red pixel Pr, green pixel Pg, and blue pixel Pb) are in a generally rhomboid planar shape and arranged in a matrix. Furthermore, the light-emitting device 1B has a structure substantially the same as that of the light-emitting device 1 according to the above embodiments.

[0193] Similarly, with this construction, the light-emitting device 1J can achieve an effect similar to that of the light-emitting device 1 according to the above embodiment.

[0194] [2-11. Variation Example 11]

[0195] Figures 18 to 20 Examples of planar layouts of the metal film 114, pad electrode 14B1, and pad electrode 14B2 in the light-emitting device (e.g., light-emitting device 1) of this disclosure are shown schematically.

[0196] For example, such as Figure 18 As shown, pad electrodes 14B1 and 14B2 can be arranged side-by-side along one side of the frame portion 100B, which has a rectangular shape. For example, as Figure 19 As shown, pad electrodes 14B1 and 14B2 can be arranged, for example, such that pad electrode 14B1 is arranged along the short side of the frame portion 100B having a rectangular shape, and pad electrode 14B2 is arranged along its long side. For example, as... Figure 20 As shown, pad electrode 14B1 and pad electrode 14B2 can be arranged, for example, such that pad electrode 14B1 is arranged along the long side of the frame portion 100B having a rectangular shape and pad electrode 14B2 is arranged along its short side.

[0197] [2-12. Variation Example 12]

[0198] Figure 21 and Figure 22 This is a schematic diagram showing an example of the planar layout of the metal film 114B in a light-emitting device (e.g., light-emitting device 1E) of the present disclosure.

[0199] For example, such as Figure 21 As shown, the metal film 114B can be partially configured to connect the side of the metal film 114 near the pad electrode 14B1 to the pad electrode 14B1. For example, as Figure 22 As shown, the metal film 114B can be formed in a frame shape to surround the grid-shaped metal film 114 disposed in the display section 100A.

[0200] <3. Application Examples>

[0201] (Application Example 1)

[0202] Figure 23 This is a perspective view illustrating a schematic structural example of an image display device (image display device 100). The image display device 100 is a so-called LED display and includes light-emitting devices (e.g., light-emitting device 1) of this disclosure as display pixels. For example, as... Figure 23 As shown, the image display device 100 includes a display panel 120 and a control circuit 140 for driving the display panel 120.

[0203] The display panel 120 includes a mounting substrate 120A and a counter substrate 120B that overlap each other. The surface of the counter substrate 120B serves as an image display surface. The counter substrate 120B has a display area (display portion 100A) in its middle portion and includes a frame portion 100B around the display area. The frame portion 100B is a non-display area.

[0204] Figure 24 An example of wiring layout is shown in the area corresponding to the display unit 100A on the surface of the mounting substrate 120A on the side of the opposing substrate 120B. For example, Figure 24 As shown, in the area corresponding to the display unit 100A on the surface of the mounting substrate 120A, a plurality of data lines 134 are arranged to extend in a predetermined direction and side-by-side at a predetermined spacing. Furthermore, in the area corresponding to the display unit 100A on the surface of the mounting substrate 120A, for example, a plurality of scan lines 135 are arranged to extend in a direction intersecting (e.g., orthogonal) to the data lines 134 and side-by-side at a predetermined spacing. The data lines 134 and the scan lines 135 are, for example, made of a conductive material such as Cu.

[0205] Scan wiring 135 is disposed, for example, on the uppermost layer, or on an insulating layer (not shown) on the surface of the substrate. It should be noted that the substrate of mounting substrate 120A may include, for example, a silicon substrate, a resin substrate, etc., and the insulating layer on the substrate may include, for example, SiN, SiO, aluminum oxide (AlO), or a resin material. Meanwhile, data wiring 134 is disposed in a layer different from the uppermost layer including scan wiring 135 (e.g., a layer below the uppermost layer), and is disposed, for example, in an insulating layer on the substrate.

[0206] The area near the intersection of data wiring 134 and scan wiring 135 is used as a display pixel 136. Multiple display pixels 136 are arranged in a matrix in the display unit 100A. For example, each display pixel 136 may include any one of the color pixels Pr, Pg, and Pb of the light-emitting device 1.

[0207] For example, the light-emitting device 1 has a pair of terminal electrodes arranged according to color pixels Pr, Pg, and Pb, or it has terminal electrodes shared with color pixels Pr, Pg, and Pb and other terminal electrodes arranged according to color pixels Pr, Pg, and Pb. Furthermore, one terminal electrode is electrically connected to the data wiring 134, and the other terminal electrode is electrically connected to the scan wiring 135. For example, one terminal electrode is electrically connected to a pad electrode 134B located at the front end of a branch 134A on the data wiring 134. Additionally, for example, the other terminal electrode is electrically connected to a pad electrode 135B located at the front end of a branch 135A on the scan wiring 135.

[0208] For example, such as Figure 24 As shown, each of the pad electrodes 134B and 135B is disposed in the uppermost layer, and is disposed, for example, at the portion where each light-emitting device 1 is mounted. Here, the pad electrodes 134B and 135B are made of a conductive material such as Au (gold).

[0209] The mounting substrate 120A is also provided with, for example, a plurality of pillars (not shown), which define the interval between the mounting substrate 120A and the opposing substrate 120B. The pillars may be provided in the area opposite to the display section 100A, or in the area opposite to the frame section 100B.

[0210] The opposing substrate 120B includes, for example, a glass substrate or a resin substrate. The surface of the opposing substrate 120B on the side of the light-emitting device 1 can be flat, but is preferably roughened. The roughened surface can be provided over the entire area opposite to the display unit 100A, or it can be provided only in the area opposite to the display pixel 136. The roughened surface has fine irregularities that allow light emitted from the color pixels Pr, Pg, and Pb to be incident on the roughened surface. The irregularities of the roughened surface can be manufactured, for example, by sandblasting or dry etching.

[0211] Control circuitry 140 is configured to drive each display pixel 136 (each light-emitting device 1) based on an image signal. For example, control circuitry 140 includes a data driver and a scan driver. The data driver drives data wiring 134 coupled to the display pixel 136. The scan driver drives scan wiring 135 coupled to the display pixel 136. For example, as... Figure 23 As shown, the control circuit 140 is separately disposed from the display panel 120 and can be connected to the mounting substrate 120A via wiring, or can be mounted on the mounting substrate 120A.

[0212] (Application Example 2)

[0213] Figure 25 This is a perspective view showing another construction example (image display device 200) of an image display device including a light-emitting device (e.g., light-emitting device 1) of the present disclosure. Image display device 200 is a so-called tiled display that includes multiple light-emitting devices using LEDs as a light source. Image display device 200, for example, is... Figure 25 As shown, it includes a display panel 220 and a control circuit 240 for driving the display panel 220.

[0214] The display panel 220 includes a mounting substrate 220A and a counter substrate 220B that overlap each other. The surface of the counter substrate 220B serves as an image display surface. The counter substrate 220B includes a display area in the middle portion and includes a frame portion surrounding the display area. The frame portion is a non-display area. The counter substrates 220B are arranged, for example, at predetermined intervals at positions opposite to the mounting substrate 220A. It should be noted that the counter substrate 220B may contact the upper surface of the mounting substrate 220A.

[0215] Figure 26 An example of the construction of mounting substrate 220A is schematically shown. For example, as... Figure 26 As shown, the mounting substrate 220A includes a plurality of unit substrates 250 arranged in a tile-like pattern. It should be noted that, although... Figure 26 An example of mounting substrate 220A including nine unit substrates 250 is shown, but the number of unit substrates 250 may be more than ten or less.

[0216] Figure 27 An example of the construction of a unit substrate 250 is schematically shown. The unit substrate 250 includes, for example, a plurality of light-emitting devices 1 arranged in a tile-like pattern and a support substrate 260 supporting each light-emitting device 1. Each unit substrate 250 also includes a control substrate (not shown). The support substrate 260 includes, for example, a metal frame (metal plate), a wiring substrate, etc. When the support substrate 260 includes a wiring substrate, the support substrate 260 can also be used as a control substrate. In this case, the support substrate 260, the control substrate, or both are electrically connected to each light-emitting device 1.

[0217] (Application Example 3)

[0218] Figure 28 The appearance of the transparent display 300 is shown. For example, the transparent display 300 includes a display unit 310, an operation unit 311, and a housing 312. The display unit 310 includes a light-emitting device of this disclosure (e.g., light-emitting device 1). The transparent display 300 is configured to display images, text information, etc., while allowing the background of the display unit 310 to be transparent.

[0219] In the transparent display 300, the mounting substrate includes a light-transmitting substrate. Each electrode disposed in the light-emitting device 1 contains the same light-transmitting conductive material as the mounting substrate. Alternatively, reducing the width or thickness of the wiring allows for a structure where each electrode is not visually discernible. Furthermore, for example, the transparent display 300 can perform a black display by overlapping a liquid crystal layer including driving circuitry, and can switch between a transparent state and a black display state by controlling the light distribution direction of the liquid crystal.

[0220] Although the present technology has been described above with reference to embodiments, variations 1 to 11 and application examples, the present technology is not limited to the above embodiments and can be modified in various ways. For example, the above embodiments have referenced examples where the light emitted from the compound semiconductor layer 11 is blue light or ultraviolet light; however, this is not limiting. For example, the light-emitting device 1 may include a light-emitting element that emits two or more types of light (such as a combination of blue light and green light or a combination of ultraviolet light and green light).

[0221] Furthermore, in the above embodiments, each component included in the light-emitting device 1, etc., has been specifically described; however, it is not necessary to include all components, and any other components may also be included.

[0222] Furthermore, any two or more of the above variations 1 to 11 can be combined with each other.

[0223] It should be noted that the effects described herein are merely illustrative and not limiting, and any other effects may be achieved.

[0224] This disclosure can have any of the following configurations. According to this disclosure having any of the following configurations, a light-reflective metal film is provided on the side and bottom surfaces of a trench disposed from a second surface side serving as a light extraction surface of a compound semiconductor layer included in the light-emitting portion. This reduces stray light, light leakage to adjacent pixels, etc. Therefore, crosstalk can be suppressed.

[0225] (1) A light-emitting device, comprising: Drive substrate; The compound semiconductor layer includes a first surface opposite to the driving substrate and a second surface located on the opposite side of the first surface. The compound semiconductor layer includes a first conductivity layer, an active layer and a second conductivity layer stacked sequentially from the driving substrate side. A first separation trench is formed from the first surface side and separates the first conductive layer and the active layer for each pixel; A second separation trench is disposed on the second surface side at a position opposite to the first separation trench, and the second separation trench separates a portion of the second conductive layer for each pixel; and A first metal film is disposed along the sides and bottom of the second separation trench and has light reflectivity.

[0226] (2) According to the light-emitting device of (1) above, the first metal film is also used as wiring to electrically connect the driving substrate and the second conductive layer to each other.

[0227] (3) The light-emitting device according to (1) or (2) above further includes: The second metal film, wherein The second metal film comprises a light-reflective metal material disposed along the sides and bottom of the first separation trench.

[0228] (4) The light-emitting device according to any one of (1) to (3) above, wherein the first metal film comprises aluminum, silver or both aluminum and silver.

[0229] (5) The light-emitting device according to (3) above, wherein the second metal film comprises aluminum, silver or both aluminum and silver.

[0230] (6) A light-emitting device according to any one of (1) to (5) above, wherein, The compound semiconductor layer also includes an undoped semiconductor layer and a buffer layer, and An undoped semiconductor layer and a buffer layer are stacked sequentially on the second conductivity layer.

[0231] (7) The light-emitting device according to any one of (1) to (6) above, wherein the first separation groove is filled with a first metal film.

[0232] (8) The light-emitting device according to any one of (1) to (7) above, wherein the width of the bottom surface of the first separation groove is greater than the width of the bottom surface of the second separation groove.

[0233] (9) The light-emitting device according to any one of (1) to (8) above, wherein the side of the second separation groove is inclined at an angle of less than 90 degrees.

[0234] (10) The light-emitting device according to any one of (1) to (9) above, wherein the second conductive layer is continuous between pixels.

[0235] (11) The light-emitting device according to any one of (1) to (10) above further includes

[0236] Wavelength conversion layer, in which, A wavelength conversion layer is disposed above the second surface of the compound semiconductor layer, and the wavelength conversion layer converts light emitted from the active layer into light within a predetermined wavelength band.

[0237] (12) The light-emitting device according to (11) above, wherein the wavelength conversion layer includes a color conversion material.

[0238] (13) The light-emitting device according to (11) or (12) above, wherein, The pixel includes a first pixel and a second pixel, wherein light with a wavelength band substantially the same as the wavelength band of the light emitted from the active layer is extracted from the first pixel, and light with a wavelength band different from the wavelength band of the light emitted from the active layer is extracted from the second pixel. The wavelength conversion layer disposed in the first pixel contains a light-transmitting resin, and The wavelength conversion layer set in the second pixel contains color conversion material.

[0239] (14) The light-emitting device according to any one of (11) to (13) above further includes: A light-reflecting film selectively reflects light of a predetermined wavelength band, wherein... The pixel includes a first pixel and a second pixel, wherein light with a wavelength band substantially the same as the wavelength band of the light emitted from the active layer is extracted from the first pixel, and light with a wavelength band different from the wavelength band of the light emitted from the active layer is extracted from the second pixel. The light-reflecting film is positioned above the wavelength conversion layer set in the second pixel.

[0240] (15) The light-emitting device according to any one of (11) to (14) above further includes: A light-absorbing film selectively absorbs light of a predetermined wavelength band, wherein... The pixel includes a first pixel and a second pixel, wherein light with a wavelength band substantially the same as the wavelength band of the light emitted from the active layer is extracted from the first pixel, and light with a wavelength band different from the wavelength band of the light emitted from the active layer is extracted from the second pixel. The light absorption film is disposed above the wavelength conversion layer in the second pixel.

[0241] (16) The light-emitting device according to any one of (1) to (15) above further includes: Lens, among which, The lens is positioned above the second surface of the compound semiconductor layer.

[0242] (17) An image display device, comprising: Light-emitting device, wherein The light-emitting device includes: Drive substrate, The compound semiconductor layer includes a first surface opposite to the driving substrate and a second surface located on the opposite side of the first surface. The compound semiconductor layer includes a first conductivity layer, an active layer, and a second conductivity layer stacked sequentially from the driving substrate side. A first separation trench is formed from the first surface side and separates the first conductivity layer and the active layer for each pixel. A second separation trench is disposed on the second surface side at a position opposite to the first separation trench. This second separation trench separates a portion of the second conductive layer for each pixel. A first metal film is disposed along the sides and bottom of the second separation trench and has light reflectivity.

[0243] This application claims priority to Japanese Patent Application No. JP2023-215130, filed with the Japan Patent Office on December 20, 2023, the entire contents of which are incorporated herein by reference.

[0244] Those skilled in the art will understand that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors, as long as they are within the scope of the appended claims or their equivalents.

Claims

1. A light-emitting device, comprising: Drive substrate; The compound semiconductor layer includes a first surface opposite to the driving substrate and a second surface located on the opposite side of the first surface. The compound semiconductor layer includes a first conductivity layer, an active layer and a second conductivity layer stacked sequentially from the driving substrate side. A first separation trench is formed from the first surface side and separates the first conductive layer and the active layer for each pixel; A second separation trench is disposed from the second surface side at a position opposite to the first separation trench, and the second separation trench separates a portion of the second conductive layer for each pixel; as well as A first metal film is disposed along the side and bottom surfaces of the second separation trench and has light reflectivity.

2. The light-emitting device according to claim 1, wherein, The first metal film also serves as wiring to electrically connect the driving substrate and the second conductive layer to each other.

3. The light-emitting device according to claim 1, further comprising: The second metal film, wherein, The second metal film comprises a light-reflective metal material disposed along the sides and bottom of the first separation trench.

4. The light-emitting device according to claim 1, wherein, The first metal film comprises aluminum, silver, or both aluminum and silver.

5. The light-emitting device according to claim 3, wherein, The second metal film comprises aluminum, silver, or both aluminum and silver.

6. The light-emitting device according to claim 1, wherein, The compound semiconductor layer further includes an undoped semiconductor layer and a buffer layer, and The undoped semiconductor layer and the buffer layer are stacked sequentially on the second conductivity layer.

7. The light-emitting device according to claim 1, wherein, The first separation trench is filled with the first metal membrane.

8. The light-emitting device according to claim 1, wherein, The width of the bottom surface of the first separation trench is greater than the width of the bottom surface of the second separation trench.

9. The light-emitting device according to claim 1, wherein, The sides of the second separation groove are inclined at an angle of less than 90 degrees.

10. The light-emitting device according to claim 1, wherein, The second conductive layer is continuous between the pixels.

11. The light-emitting device according to claim 1, further comprising: Wavelength conversion layer, in which, The wavelength conversion layer is disposed above the second surface of the compound semiconductor layer, and the wavelength conversion layer converts light emitted from the active layer into light within a predetermined wavelength band.

12. The light-emitting device according to claim 11, wherein, The wavelength conversion layer includes a color conversion material.

13. The light-emitting device according to claim 11, wherein, The pixel includes a first pixel and a second pixel, wherein light with a wavelength band substantially the same as the wavelength band of the light emitted from the active layer is extracted from the first pixel, and light with a wavelength band different from the wavelength band of the light emitted from the active layer is extracted from the second pixel. The wavelength conversion layer disposed in the first pixel comprises a light-transmitting resin, and The wavelength conversion layer disposed in the second pixel contains a color conversion material.

14. The light-emitting device according to claim 11, further comprising: A light-reflecting film selectively reflects light of a predetermined wavelength band, wherein... The pixel includes a first pixel and a second pixel, wherein light with a wavelength band substantially the same as the wavelength band of the light emitted from the active layer is extracted from the first pixel, and light with a wavelength band different from the wavelength band of the light emitted from the active layer is extracted from the second pixel. The light-reflecting film is disposed above the wavelength conversion layer disposed in the second pixel.

15. The light-emitting device according to claim 11, further comprising: A light-absorbing film selectively absorbs light of a predetermined wavelength band, wherein... The pixel includes a first pixel and a second pixel, wherein light with a wavelength band substantially the same as the wavelength band of the light emitted from the active layer is extracted from the first pixel, and light with a wavelength band different from the wavelength band of the light emitted from the active layer is extracted from the second pixel. The light-absorbing film is disposed above the wavelength conversion layer disposed in the second pixel.

16. The light-emitting device according to claim 1, further comprising: Lens, among which, The lens is disposed above the second surface of the compound semiconductor layer.

17. An image display device, comprising: Light-emitting device, wherein The light-emitting device includes: Drive substrate, The compound semiconductor layer includes a first surface opposite to the driving substrate and a second surface located on the opposite side of the first surface. The compound semiconductor layer includes a first conductivity layer, an active layer, and a second conductivity layer sequentially stacked from the driving substrate side. A first separation trench is formed from the first surface side and separates the first conductive layer and the active layer for each pixel. A second separation trench is disposed on the second surface side at a position opposite to the first separation trench. The second separation trench separates a portion of the second conductive layer for each pixel. A first metal film is disposed along the side and bottom surfaces of the second separation trench and has light reflectivity.

Images