Light-emitting element, light-emitting device, and image display apparatus

Abstract

A light-emitting element according to one embodiment of the present disclosure comprises: a compound semiconductor layer that has a first surface serving as a light emission surface and a second surface on the side opposite to the first surface, and that includes an active layer which emits light; a first electrode that is provided to cover the first surface of the compound semiconductor layer; a second electrode that is provided on the second surface side of the compound semiconductor layer; a first contact part that penetrates the active layer and is electrically connected to the first electrode; and a second contact part that is electrically connected to the second electrode.

Description

Light-emitting element, light-emitting device, and image display device 【0001】 This disclosure relates to a light-emitting element, a light-emitting device equipped with the light-emitting element, and an image display device. 【0002】 To date, image display elements have been proposed in which, for example, multiple micro-light-emitting elements provided within a pixel region are connected to a P-connection region outside the pixel region via a common P-electrode (see, for example, Patent Document 1). 【0003】 Japanese Patent Publication No. 2021-019015 【0004】 By the way, in light-emitting devices that use multiple micro-LEDs (Light Emitting Diodes), uniformity of light intensity is required. 【0005】 A light-emitting element as one embodiment of the present disclosure comprises a compound semiconductor layer having a first surface that serves as a light-emitting surface and a second surface opposite to the first surface, and including a light-emitting active layer; a first electrode provided so as to cover the first surface of the compound semiconductor layer; a second electrode provided on the second surface side of the compound semiconductor layer; a first contact portion that penetrates the active layer and is electrically connected to the first electrode; and a second contact portion that is electrically connected to the second electrode. 【0006】 A light-emitting device as one embodiment of the present disclosure comprises a plurality of light-emitting elements, wherein the plurality of light-emitting elements include the light-emitting elements of the above embodiment of the present disclosure. 【0007】 An image display device as one embodiment of the present disclosure is equipped with a light-emitting element, and as the light-emitting element, it has the light-emitting element of the present disclosure described above. 【0008】 In a light-emitting element as one embodiment of the present disclosure, a light-emitting device as one embodiment of the present disclosure, and an image display device as one embodiment of the present disclosure, the first contact portion is provided inside a compound semiconductor layer, so that in a light-emitting device equipped with a plurality of such light-emitting elements, the distance between the first contact electrode and the light-emitting element becomes uniform. 【0009】Figure 1 is a schematic cross-sectional view showing an example of the configuration of a light-emitting device equipped with a plurality of light-emitting elements according to the first embodiment of the present disclosure. Figure 2 is a schematic plan view showing an example of the configuration of the light-emitting device shown in Figure 1. Figure 3A is a schematic cross-sectional view illustrating an example of the manufacturing process of the light-emitting element shown in Figure 1. Figure 3B is a schematic cross-sectional view showing the process following Figure 3A. Figure 3C is a schematic cross-sectional view showing the process following Figure 3B. Figure 3D is a schematic cross-sectional view showing the process following Figure 3C. Figure 3E is a schematic cross-sectional view showing the process following Figure 3D. Figure 3F is a schematic cross-sectional view showing the process following Figure 3E. Figure 3G is a schematic cross-sectional view showing the process following Figure 3F. Figure 4A is a schematic cross-sectional view showing an example of the configuration of a light-emitting element according to Modification 1 of the present disclosure. Figure 4B is a schematic cross-sectional view showing another example of the configuration of a light-emitting element according to Modification 1 of the present disclosure. Figure 5 is a schematic cross-sectional view showing an example of the configuration of a light-emitting element according to Modification 2 of the present disclosure. Figure 6A is a schematic cross-sectional view showing an example of the configuration of a light-emitting element according to Modification 3 of the present disclosure. Figure 6B is a schematic plan view showing an example of the configuration of a light-emitting device according to Modification 3 of the present disclosure. Figure 7 is a schematic cross-sectional view showing an example of the configuration of a light-emitting element according to the second embodiment of the present disclosure. Figure 8A is a schematic cross-sectional view illustrating an example of the manufacturing process of the light-emitting element shown in Figure 7. Figure 8B is a schematic cross-sectional view showing the process following Figure 8A. Figure 8C is a schematic cross-sectional view showing the process following Figure 8B. Figure 9A is a schematic cross-sectional view showing an example of a method for manufacturing a light-emitting element according to Modification 4 of the present disclosure. Figure 9B is a schematic cross-sectional view showing the process following Figure 9A. Figure 9C is a schematic cross-sectional view showing the process following Figure 9B. Figure 10A is a schematic cross-sectional view showing an example of a method for manufacturing a light-emitting element according to Modification 5 of the present disclosure. Figure 10B is a schematic cross-sectional view showing the process following Figure 10A. Figure 11 is a schematic cross-sectional view showing an example of the configuration of a light-emitting element according to Modification 6 of the present disclosure. Figure 12A is a front view showing an example of the appearance of a digital still camera as an application example of the present disclosure. Figure 12B is a rear view showing an example of the appearance of the digital still camera shown in Figure 12A. Figure 13A is a perspective view showing the appearance of an example of a head-mounted display as an application of the present disclosure. Figure 13B is a perspective view showing the appearance of another example of a head-mounted display as an application of the present disclosure. Figure 14 is a perspective view showing an example of the appearance of a television apparatus as an application of the present disclosure.Figure 15 is a schematic cross-sectional view showing an example of the configuration of a light-emitting device equipped with multiple light-emitting elements according to a third embodiment of the present disclosure. Figure 16 is a schematic plan view showing an example of the configuration of the light-emitting device shown in Figure 15. Figure 17 is a schematic cross-sectional view showing an example of the configuration of a light-emitting device equipped with multiple light-emitting elements according to Modification 7 of the present disclosure. Figure 17 is a schematic cross-sectional view showing another example of the configuration of a light-emitting device equipped with multiple light-emitting elements according to Modification 7 of the present disclosure. Figure 19 is a schematic cross-sectional view showing an example of the configuration of a light-emitting device equipped with multiple light-emitting elements according to Modification 8 of the present disclosure. Figure 20 is a schematic plan view showing an example of the configuration of the light-emitting device shown in Figure 19. Figure 21 is a schematic cross-sectional view showing an example of the configuration of a light-emitting device equipped with multiple light-emitting elements according to Modification 9 of the present disclosure. Figure 22 is a schematic cross-sectional view showing an example of the configuration of a light-emitting device equipped with multiple light-emitting elements according to Modification 10 of the present disclosure. Figure 23 is a schematic cross-sectional view showing an example of the configuration of a light-emitting element according to a fourth embodiment of the present disclosure. Figure 24 is a schematic cross-sectional view showing an example of the configuration of a light-emitting element according to Modification 11 of the present disclosure. Figure 25 is a schematic cross-sectional view showing an example of the configuration of a light-emitting element according to Modification 12 of the present disclosure. 【0010】Hereinafter, one embodiment of the present disclosure will be described in detail with reference to the drawings. The following description is a specific example of the present disclosure, and the present disclosure is not limited to the following embodiments. Furthermore, the present disclosure is not limited to the arrangement, dimensions, dimensional ratios, etc., of each component shown in each figure. The order of description is as follows: 1. First Embodiment (Example in which a first contact portion is provided in the compound semiconductor layer of the light-emitting element) 1-1. Configuration of the light-emitting element 1-2. Method for manufacturing the light-emitting element 1-3. Operation and effects 2. Modifications of the First Embodiment 2-1. Modification 1 (Another example of a light-emitting element) 2-2. Modification 2 (Another example of a light-emitting element) 2-3. Modification 3 (Another example of a light-emitting element) 3. Second Embodiment (Example in which a hydrogen-absorbing metal film is provided covering the compound semiconductor layer of the light-emitting element) 3-1. Configuration of the light-emitting element 3-2. Method for manufacturing the light-emitting element 3-3. Operation and effects 4. Modifications of the Second Embodiment 4-1. Modification 4 (Another example of a method for manufacturing the light-emitting element) 4-2. Modification 5 (Another example of a method for manufacturing a light-emitting element) 4-3. Modification 6 (Another example of a light-emitting element) 5. Third Embodiment (An example in which a light-shielding structure is provided between adjacent light-emitting elements) 5-1. Configuration of the light-emitting device 5-2. Operation and effects 6. Modifications of the Third Embodiment 6-1. Modification 7 (Another example of a light-emitting device) 6-2. Modification 8 (Another example of a light-emitting device) 6-3. Modification 9 (Another example of a light-shielding structure) 6-4. Modification 10 (Another example of a light-shielding structure) 7. Fourth Embodiment (An example in which a metal diffusion prevention layer is provided to cover the compound semiconductor layer of the light-emitting element) 7-1. Configuration of the light-emitting device 7-2. Operation and effects 8. Modifications of the Fourth Embodiment 8-1. Modification 11 (Another example of the configuration of a light-emitting element) 8-2. Modification 12 (Another example of the configuration of a light-emitting element) 9. Application examples 【0011】 <1. First Embodiment> Figure 1 schematically shows an example of a cross-sectional configuration of a light-emitting device 1 equipped with a plurality of light-emitting elements 10 according to the first embodiment of the present disclosure. Figure 2 schematically shows an example of a planar configuration of the light-emitting device 1 shown in Figure 1. Figure 2 shows the planar configuration of the light-emitting device 1 as viewed from the first surface 11S1 side of the compound semiconductor layer 11, which will be described later. 【0012】 In the light-emitting device 1, multiple light-emitting elements 10 are arranged in a two-dimensional array in the XY plane. The light-emitting device 1 is suitably applicable to image display devices known as LED displays (for example, the electronic viewfinder 1124 of a digital still camera 1120, see Figure 12B). 【0013】 [1-1. Configuration of Light-Emitting Devices] 【0014】 The light-emitting element 10 is provided with a compound semiconductor layer 11, a first electrode 12, a second electrode 13, a first contact portion 14, a second contact portion 15, a protective film 16, an insulating layer 171, and an insulating layer 172. 【0015】 The light-emitting element 10 is a solid-state light-emitting element that emits light in a predetermined wavelength band from its upper surface, and is, for example, an LED chip. An LED chip refers to an LED that has been cut from a wafer used for crystal growth, and is not a package type covered with molded resin or the like. The LED chip is, for example, 100 μm or less in size, and is what is known as a microLED. 【0016】 The compound semiconductor layer 11 has, for example, a mesa shape. The mesa size of the compound semiconductor layer 11 is, for example, 1.2 μm or more and 3 μm or less. The side walls of the compound semiconductor layer 11 are inclined at an angle of less than 90° with respect to the XY plane, for example. That is, the compound semiconductor layer 11 has, for example, a forward taper shape. 【0017】 The compound semiconductor layer 11 has a first surface 11S1 which is the light-emitting surface and a second surface 11S2 opposite to the first surface 11S1. The compound semiconductor layer 11 includes, for example, a first conductivity type layer 111, an active layer 112, and a second conductivity type layer 113 in order from the second surface side in the Z-axis direction, which is the thickness direction perpendicular to the XY plane. The compound semiconductor layer 11 has a thickness of, for example, 1 μm or more and 3 μm or less. 【0018】The first conductivity layer 111 is formed of, for example, an n-type GaN-based semiconductor material. The active layer 112 has a multiple quantum well structure in which, for example, InGaN and GaN are alternately stacked, and has light-emitting regions within the layer. Light in the blue band, for example, between 430 nm and 500 nm, is extracted from the active layer 112. Light with wavelengths corresponding to the ultraviolet region (ultraviolet light) may also be extracted from the active layer 112. The second conductivity layer 113 is formed of, for example, a p-type GaN-based semiconductor material. 【0019】 The first electrode 12 is provided so as to cover the first surface 11S1 of the compound semiconductor layer 11. The first electrode 12 is formed from a transparent electrode material such as indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO), or titanium oxide (TiO). 【0020】 The second electrode 13 is provided on the second surface 11S2 side of the compound semiconductor layer 11. The second electrode 13 includes, in order from the compound semiconductor layer 11 side, an electrode layer 131 and a light reflection layer 132. 【0021】 The electrode layer 131 is in ohmic contact with, for example, the first conductivity type layer 111. The electrode layer 131 is formed using, for example, a transparent conductive material such as a multilayer film of nickel (Ni) and gold (Au) (Ni / Au) or ITO. The electrode layer 131 may also be composed of a metal such as titanium (Ti), titanium nitride (TiN), tantalum nitride (TaN), aluminum (Al), silver (Ag), or a multilayer film of these materials. 【0022】 The light-reflecting layer 132 is provided between the compound semiconductor layer 11 and the insulating layer 172. The light-reflecting layer 132 is formed using a light-reflecting metal, dielectric material, or a multilayer film made by stacking these materials. Examples of metals used in the light-reflecting layer 132 include titanium (Ti), aluminum (Al), and silver (Ag). 【0023】The first contact portion 14 has a pad portion 14P and a via 14V. The first contact portion 14 is provided on the second surface 11S2 side of the compound semiconductor layer 11, penetrates the active layer 112, and is electrically connected to the first electrode 12. The via 14V penetrates the insulating layer 172, the second electrode 13, the first conductivity type layer 111, and the second conductivity type layer 113. The via 14V includes, for example, at least one of indium tin oxide (ITO), indium oxide (InO), indium zinc oxide (IZO), indium-gallium-zinc oxide (IGZO), titanium (Ti), titanium nitride (TiN), and tungsten (W). The diameter of the via 14V is, for example, 100 nm to 300 nm. The pad portion 14P is formed using, for example, copper (Cu), aluminum (Al), tungsten (W), silver (Ag), or alloys thereof. 【0024】 The second contact portion 15 has a pad portion 15P and a via 15V. Similar to the first contact portion 14, the second contact portion 15 is provided on the second surface 11S2 side of the compound semiconductor layer 11 and is electrically connected to the second electrode 13. The via 15V penetrates the insulating layer 172 and the light reflective layer 132. The via 15V includes, for example, at least one of indium tin oxide (ITO), indium oxide (InO), indium zinc oxide (IZO), indium-gallium-zinc oxide (IGZO), titanium (Ti), titanium nitride (TiN), and tungsten (W). The diameter of the via 15V is, for example, 100 nm to 300 nm. The pad portion 15P is formed using, for example, copper (Cu), aluminum (Al), tungsten (W), silver (Ag), or alloys thereof. 【0025】 The vias 14V and 15V are arranged parallel to the X-axis in a plan view, as shown in Figure 2, for example. In the light-emitting device 1 equipped with multiple light-emitting elements 10, the distance between the via 14V of the first contact portion 14 and the via 15V of the second contact portion 15 of each of the multiple light-emitting elements 10 is approximately the same. 【0026】The protective film 16 is provided so as to cover the sidewall of the compound semiconductor layer 11. Furthermore, the protective film 16 extends along the surface of the insulating layer 172 that is in contact with the second electrode 13. The protective film 16 protects the surfaces of the compound semiconductor layer 11 and the insulating layer 172 during the manufacturing process of the light-emitting element 10. The protective film 16 is made of, for example, aluminum oxide (Al ２ O ３ It is formed using ) etc. 【0027】 The insulating layer 171 covers the first electrode 12 and the protective film 16, and is provided to fill the space between adjacent light-emitting elements 10. The insulating layer 171 is intended to flatten the light-emitting surface of the light-emitting elements 10. The insulating layer 171 is formed using, for example, silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiON), and titanium oxide (TiO). 【0028】 The insulating layer 172 is provided to fill the space between the second electrode 13 and the first contact portion 14, and between the second electrode 13 and the second contact portion 15. The insulating layer 172 is intended to flatten the surface of the light-emitting element 10 that is opposite to the light-emitting side. The insulating layer 172 is formed of, for example, silicon oxide (SiO) or silicon nitride (SiN). 【0029】 [1-2. Method for Manufacturing a Light-Emitting Device] The light-emitting device 10 of the first embodiment of this disclosure can be manufactured, for example, as follows. Figures 3A to 3G show an example of the manufacturing process for the light-emitting device 10. 【0030】 First, an insulating layer 172 is formed on the surface of the insulating layer 171 that is in contact with the protective film 16, in which the compound semiconductor layer 11, the first electrode 12, the second electrode 13, and the protective film 16 are embedded. 【0031】 Next, as shown in Figure 3A, an opening H1 is formed that penetrates the insulating layer 172, the second electrode 13, and the compound semiconductor layer 11, and exposes the first electrode 12 at its bottom surface. At this time, the opening H1 is made of, for example, chlorine (Cl ２ ) contains silicon tetrachloride (SiCl ４ It is formed by reactive ion etching (RIE) using a gas to which ) is added. 【0032】 Subsequently, as shown in FIG. 3B, a spacer 173 is formed in the aperture H1 using, for example, silicon oxide by an atomic layer deposition method (ALD). 【0033】 Next, as shown in FIG. 3C, the bottom of the spacer 173 is etched, for example, by RIE to expose the first electrode 12. 【0034】 Subsequently, as shown in FIG. 3D, a via 14V is formed that contacts the exposed first electrode 12 and fills the aperture H1. At this time, the via 14V is formed, for example, by an ALD method or a chemical vapor deposition method (CVD). 【0035】 Next, as shown in FIG. 3E, an aperture H2 is formed, for example, by RIE that penetrates the insulating layer 172 and the light reflecting layer 132 of the second electrode 13 and exposes the electrode layer 131. 【0036】 Subsequently, as shown in FIG. 3F, a via 15V is formed that contacts the electrode layer 131 exposed on the bottom surface of the aperture H2 and fills the aperture H2. At this time, the via 15V is formed, for example, by an ALD method or a CVD method. 【0037】 Subsequently, as shown in FIG. 3G, pad portions 14P and 15P are formed on the via 14V and the via 15V, respectively. Thus, the light emitting element 10 shown in FIG. 1 is completed. 【0038】 [1-3. Operation and Effect] The light emitting element 10 of the first embodiment has a first surface 11S1 that serves as a light emitting surface and a second surface 11S2 on the opposite side of the first surface, and includes a compound semiconductor layer 11 including an active layer 112 that emits light, a first electrode 12 provided so as to cover the first surface 11S1, and a second electrode 13 provided on the second surface 11S2 side. The light emitting element 10 further includes a first contact portion 14 that penetrates the active layer 112 from the second surface 11S2 side of the compound semiconductor layer 11 and is electrically connected to the first electrode 12, and a second contact portion 15 that is electrically connected to the second electrode 13. By providing the first contact portion 14 inside the compound semiconductor layer 11, the distances between the first contact portion 14 and the light emitting elements 10 in the light emitting device 1 including a plurality of light emitting elements 10 become uniform. Hereinafter, this will be described. 【0039】 As mentioned above, in typical light-emitting devices, a common electrode is provided on the light-emitting surface side that is shared by multiple light-emitting elements arranged within the pixel area. The common electrode is electrically connected to one or more contact electrodes provided outside the pixel area, and a voltage is applied to the multiple light-emitting elements via this contact electrode and the common electrode. Therefore, the distances between the contact electrodes and each of the multiple light-emitting elements are different, and the non-uniformity of the light emission intensity within the pixel area due to the voltage drop caused by the IR drop is a problem. 【0040】 As a solution to the above problem, a light-emitting device can be provided in which a contact electrode is provided for each light-emitting element and electrically connected from the light-emitting surface side. However, in this light-emitting device, the light-emitting area is reduced by the area of ​​the contact electrode, so the light-emitting intensity per unit area decreases. 【0041】 Therefore, in the light-emitting element 10 of the first embodiment, as described above, the first contact portion 14, which is connected to the first electrode 12 provided on the first surface 11S1 of the compound semiconductor layer 11 that serves as the light-emitting surface, is provided within the compound semiconductor layer 11. This makes it possible to maintain the light emission intensity per unit area. Furthermore, in a light-emitting device 1 equipped with multiple light-emitting elements 10, the voltage drop can be suppressed by providing a first contact portion 14 for each light-emitting element 10, thus solving the above problem. 【0042】 As described above, the light-emitting element 10 of the first embodiment makes it possible to provide a light-emitting device 1 in which the light-emitting intensity is uniform within the plane. 【0043】 Furthermore, the light-emitting element 10 of the first embodiment can be mounted at a higher density compared to when a contact electrode is provided externally for each light-emitting element, by providing a first contact portion 14 inside the compound semiconductor layer 11. 【0044】 Furthermore, in the manufacturing method of the light-emitting element 10 of the first embodiment, in the step of etching the compound semiconductor layer 11 by RIE, chlorine (Cl ２ ) contains silicon tetrachloride (SiCl ４A gas to which ) was added was used. This makes it possible to suppress the generation of residue, such as GaN, that occurs when the compound semiconductor layer 11 is etched. This makes it possible to reduce damage to the active layer 112. 【0045】 <2. Modifications> Next, modifications 1 to 3 of the first embodiment of the present disclosure will be described. The same reference numerals are used for the components corresponding to the light-emitting device 1 of the first embodiment, and their descriptions are omitted. 【0046】 [2-1. Modification 1] Figure 4A schematically shows an example of the cross-sectional configuration of a light-emitting element (light-emitting element 10A-1) according to Modification 1 of the present disclosure. Figure 4B schematically shows another example of the cross-sectional configuration of a light-emitting element (light-emitting element 10A-2) according to Modification 1 of the present disclosure. 【0047】 In the first embodiment described above, an example was shown in which the sidewall of the compound semiconductor layer 11 is inclined at an angle of less than 90° with respect to the XY plane, but the present disclosure is not limited thereto. In the modified light-emitting element 10A-1, for example as shown in Figure 4A, the sidewall of the compound semiconductor layer 11a-1 may be inclined at an angle of 90° with respect to the XY plane. In the modified light-emitting element 10A-2, for example as shown in Figure 4B, the sidewall of the compound semiconductor layer 11a-2 may be inclined at an angle greater than 90° with respect to the XY plane. That is, the compound semiconductor layer 11a-2 may have, for example, an inverse tapered shape. 【0048】 Except for the points mentioned above, the configurations of the light-emitting elements 10A-1 and 10A-2 are substantially the same as the configuration of the light-emitting element 10 in the first embodiment described above. Even with such a configuration, the light-emitting elements 10A-1 and 10A-2 can obtain the same effects as in the first embodiment described above. 【0049】 [2-2. Modification 2] Figure 5 schematically shows an example of the cross-sectional configuration of a light-emitting element (light-emitting element 10B) according to Modification 2 of the present disclosure. 【0050】In the first embodiment described above, an example was shown in which the via 14V penetrates the electrode layer 131 of the second electrode 13, but the disclosure is not limited thereto. In this modified light-emitting element 10B, the area of ​​the electrode layer 131b of the second electrode 13 is reduced, and the first electrode 12 and the via 14V are connected without penetrating the electrode layer 131b. In other words, in this modified light-emitting element 10B, the area of ​​the electrode layer 131b of the second electrode 13b is smaller than the area of ​​the first electrode 12. Furthermore, the first contact portion 14 is connected to the first electrode 12 in a region that does not overlap with the electrode layer 131b of the second electrode 13b in the Z-axis direction. This prevents the electrode layer 131b from interfering with the first contact portion 14. 【0051】 Except for the points mentioned above, the configuration of the light-emitting element 10B is substantially the same as the configuration of the light-emitting element 10 in the first embodiment. Even with this configuration, the light-emitting element 10B can obtain the same effects as in the first embodiment. 【0052】 [2-3. Modification 3] Figure 6A schematically shows an example of the cross-sectional configuration of a light-emitting element (light-emitting element 10C) according to Modification 3 of the present disclosure. Figure 6B schematically shows an example of the planar configuration of a light-emitting device (light-emitting device 1C) according to Modification 3 of the present disclosure. Figure 6B shows the planar configuration of the light-emitting device 1C as viewed from the second surface 11S2 side of the compound semiconductor layer 11c. 【0053】 In the first embodiment described above, the first contact portion 14 is shown to penetrate the inside surrounded by the side walls of the active layer 112, but the disclosure is not limited thereto. In the modified light-emitting element 10C, the first contact portion 14 may penetrate at least a portion of the side walls of the compound semiconductor layer 11c, which includes the active layer 112c. In the modified light-emitting element 10C of this third embodiment, the area of ​​the active layer 112c that is etched is smaller than the area of ​​the active layer 112 of the light-emitting element 10 in the first embodiment. This makes it possible to suppress damage to the active layer 112c caused by the etching process. 【0054】In a light-emitting device 1C that has multiple light-emitting elements 10C, as shown in Figure 6B, four light-emitting elements 10C arranged in a 2x2 grid may share the via 14Vc of the first contact portion 14. 【0055】 Except for the points mentioned above, the configuration of the light-emitting element 10C is substantially the same as the configuration of the light-emitting element 10 in the first embodiment. Even with this configuration, the light-emitting element 10C can obtain the same effects as in the first embodiment. 【0056】 <3. Second Embodiment> Figure 7 schematically shows an example of the cross-sectional configuration of a light-emitting element 20 according to the second embodiment of the present disclosure. The light-emitting device 2 equipped with the light-emitting element 20 is suitably applicable to an image display device called a so-called LED display (for example, an electronic viewfinder 1124 of a digital still camera 1120, see Figure 12B). 【0057】 [3-1. Structure of the light-emitting element] The light-emitting element 20 is provided with a compound semiconductor layer 21, a first electrode 22, a second electrode 23, a first contact portion 24, a second contact portion 25, an insulating film 26, an insulating layer 271, an insulating layer 272, an insulating layer 273, a contact layer 28, and a wiring layer 29. Here, the insulating film 26 corresponds to the "first insulating film" as an embodiment of the present disclosure. The insulating layer 273 corresponds to the "second insulating film" as an embodiment of the present disclosure. 【0058】 The light-emitting element 20 is a solid-state light-emitting element that emits light in a predetermined wavelength band from its upper surface, and is, for example, an LED chip. An LED chip refers to an LED that has been cut from a wafer used for crystal growth, and is not a package type covered with molded resin or the like. The LED chip is, for example, 100 μm or less in size, and is what is known as a microLED. 【0059】The compound semiconductor layer 21 has, for example, a mesa shape. The compound semiconductor layer 21 has a first surface 21S1 which is the light emission surface and a second surface 21S2 opposite to the first surface 21S1. In the Z-axis direction, which is the thickness direction perpendicular to the XY plane, the compound semiconductor layer 21 includes, for example, a first conductivity type layer 211, an active layer 212, and a second conductivity type layer 213 in order from the second surface side. 【0060】 The first conductivity layer 211 is formed of, for example, an n-type GaN-based semiconductor material. The active layer 212 has a multiple quantum well structure in which, for example, InGaN and GaN are alternately stacked, and has light-emitting regions within the layer. Light in the blue band, for example, between 430 nm and 500 nm, is extracted from the active layer 212. Light with wavelengths corresponding to the ultraviolet region (ultraviolet light) may also be extracted from the active layer 212. The second conductivity layer 213 is formed of, for example, a p-type GaN-based semiconductor material. 【0061】 The first electrode 22 is provided so as to cover the first surface 21S1 of the compound semiconductor layer 21. The first electrode 22 is formed from a transparent electrode material such as ITO, indium zinc oxide (IZO), tin oxide (SnO), or TiO. 【0062】 The second electrode 23 is provided on the second surface side of the compound semiconductor layer 11. The second electrode 23 includes, in order from the compound semiconductor layer 21 side, an electrode layer 231 and a light reflection layer 232. 【0063】 The electrode layer 231 is in ohmic contact with, for example, the first conductivity type layer 211. The electrode layer 231 is formed using, for example, a transparent conductive material such as a multilayer film of nickel (Ni) and gold (Au) (Ni / Au) or ITO. The electrode layer 231 may also be composed of metals such as Ti, TiN, TaN, Al, Ag, or a multilayer film of these materials. 【0064】 The light-reflecting layer 232 is provided between the compound semiconductor layer 21 and the insulating layer 271. The light-reflecting layer 232 is formed using a light-reflecting metal, dielectric material, or a multilayer film made by stacking these materials. Examples of metals used in the light-reflecting layer 132 include titanium (Ti), aluminum (Al), and silver (Ag). 【0065】 The first contact portion 24 has a pad portion 24P and a via 24V. The first contact portion 14 is for electrically connecting the contact layer 28 and the wiring layer 29. The pad portion 24P and the via 24V are formed using, for example, copper (Cu), aluminum (Al), tungsten (W), silver (Ag), or alloys thereof. 【0066】 The second contact portion 25 has a pad portion 25P and a via 25V. The second contact portion 25 penetrates the light reflection layer 232 and is electrically connected to the electrode layer 231. The pad portion 25P and the via 25V are formed using, for example, copper (Cu), aluminum (Al), tungsten (W), silver (Ag), or alloys thereof. 【0067】 The insulating film 26 is provided so as to cover the first surface 21S1 and the side walls of the compound semiconductor layer 21. Furthermore, the insulating film 26 extends along the surface of the insulating layer 271 that is in contact with the second electrode 23. The insulating film 26 contains an oxide of a metal that has hydrogen storage properties. The insulating film 26 contains a metal oxide with a larger band gap than the semiconductor material constituting the compound semiconductor layer 21. The oxide formation enthalpy of the metal oxide contained in the insulating film 26 is smaller than the oxide formation enthalpy of the insulating layer 273. The insulating film 26 is, for example, made of zirconium oxide (ZrO2). ２ ), magnesium oxide (MgO ２ It is formed using ) etc. 【0068】 The insulating layer 271 has a first contact portion 24, a second contact portion 25, a contact layer 28, and a wiring layer 29 embedded within it. The insulating layer 271 is for flattening the surface of the light-emitting element 20 that is opposite to the light-emitting side. The insulating layer 271 is formed of, for example, silicon oxide (SiO) or silicon nitride (SiN). 【0069】 The insulating layer 272 is provided between the first electrode 22 and the insulating film 26. The insulating layer 272 is formed using, for example, silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiON), and titanium oxide (TiO). 【0070】The insulating layer 273 is provided so as to cover the insulating film 26. The insulating layer 273 is formed using, for example, silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiON), titanium oxide (TiO), or the like. 【0071】 [3-2. Method for manufacturing a light-emitting element] The light-emitting element 20 of the second embodiment of the present disclosure can be manufactured, for example, as follows. FIGS. 8A to 8C illustrate an example of the manufacturing process of the light-emitting element 20. 【0072】 First, an insulating layer 271 in which the first contact portion 24, the second contact portion 25, the contact layer 28, and the wiring layer 29 are embedded is prepared. Subsequently, the second electrode 23, the compound semiconductor layer 21, the first electrode 22, and the insulating layer 272 are sequentially laminated at a position on the insulating layer 271 that contacts the second contact portion 25. 【0073】 Next, as shown in FIG. 8A, the second electrode 23, the compound semiconductor layer 21, the first electrode 22, and the insulating layer 272 are formed into a mesa shape by, for example, dry etching. 【0074】 Subsequently, as shown in FIG. 8B, a metal film 261 having hydrogen storage properties is formed to cover the upper surface and side walls of the formed mesa shape and the upper surface of the insulating layer 271. The metal film 261 is formed using, for example, zirconium (Zr) or magnesium (Mg). 【0075】 Next, the metal film 261 is annealed, for example, in a nitrogen (N ２ ) gas atmosphere. By this treatment, the metal film 261 is reduced and hydrogen in the compound semiconductor layer 11 is absorbed by the metal film 261. Subsequently, as shown in FIG. 8C, an insulating layer 273 is formed so as to cover the metal film 261. As a result, the metal film 261 is oxidized to form the insulating film 26. Thus, the light-emitting element 20 shown in FIG. 7 is completed. 【0076】[3-3. Function and Effects] The light-emitting element 20 of the second embodiment is provided with an insulating film 26 containing a hydrogen-storing metal oxide that covers the first surface 21S1 and side walls of the compound semiconductor layer 21. In the manufacturing process of the light-emitting element 20, hydrogen that has entered the compound semiconductor layer 21 is absorbed by forming a hydrogen-storing metal film 261. This will be explained below. 【0077】 In typical light-emitting devices, hydrogen can penetrate the compound semiconductor layer during processes such as dry etching during mesa processing or when a protective film is deposited. A challenge in typical light-emitting devices is the deactivation of the compound semiconductor layer due to the bonding of this hydrogen with impurities added to the compound semiconductor layer. 【0078】 Therefore, in the light-emitting element 20 of the second embodiment, as described above, a metal film 261 having hydrogen-absorbing properties is formed around the compound semiconductor layer during the manufacturing process, so that hydrogen that enters the compound semiconductor layer 21 is absorbed by the metal film 261. This makes it possible to suppress the deactivation of the compound semiconductor layer 21 due to hydrogen intrusion. 【0079】 <4. Modifications> Next, modifications 4 to 6 of the second embodiment of the present disclosure will be described. The same reference numerals are used for the components corresponding to the light-emitting element 20 of the second embodiment, and their descriptions are omitted. 【0080】 [4-1. Modification 4] Figures 9A to 9C schematically show an example of the manufacturing process of a light-emitting element (light-emitting element 20A) according to Modification 4 of the present disclosure. 【0081】 In the second embodiment described above, an example was shown in which a hydrogen-storing metal film 261 is formed to cover a mesa-shaped compound semiconductor layer 21 during the manufacturing process, but the disclosure is not limited thereto. 【0082】In the manufacturing method of the light-emitting element 20A of this modified example, for example as shown in Figure 9A, after processing the compound semiconductor layer 21 into a mesa shape, an insulating film 26 containing an oxide of a hydrogen-absorbing metal may be formed to cover the first surface 21S1 and side walls of the compound semiconductor layer 21. Subsequently, the insulating film 26 is coated with, for example, nitrogen (N ２ ) Annealing is performed under a gas atmosphere. In this process, as shown in Figure 9B, the insulating film 26 is reduced to form a metal film 261, and hydrogen that has entered the compound semiconductor layer 11 is absorbed by the metal film 261. Next, oxygen is supplied to the metal film 261 to form the insulating film 26. Subsequently, as shown in Figure 9C, an insulating layer 273 is formed to cover the insulating film 26. With the above steps, the light-emitting element 20A is completed. 【0083】 Even in the light-emitting element 20A that has undergone the manufacturing process described above, the light-emitting element 20A can obtain the same effects as in the second embodiment described above. 【0084】 [4-2. Modification 5] Figures 10A and 10B schematically represent an example of the manufacturing process of a light-emitting element (light-emitting element 20B) according to Modification 5 of the present disclosure. 【0085】 In the second embodiment described above, an example was shown in which an insulating film 26 containing a hydrogen-storing metal oxide is provided to cover the first surface 21S1 and side walls of the compound semiconductor layer 21, but the disclosure is not limited thereto. In this modified example, the light-emitting element 20B is provided with a protective film 262 that covers the mesa-shaped top surface and side walls. The protective film 262 is made of, for example, silicon oxide (SiO), silicon nitride (SiN), and aluminum oxide (Al ２ O ３ ) includes at least one of the following. 【0086】 In this modified example, the light-emitting element 20B has a metal film 261 made of nitrogen (N ２ Up to the stage of annealing under gas, it can be manufactured in the same way as the light-emitting element 20. In the light-emitting element 20B, nitrogen (N ２The metal film 261 that has absorbed hydrogen that has penetrated into the compound semiconductor layer 11 by annealing in a gas atmosphere is removed, for example, by wet etching. Next, as shown in Figure 10A, a protective film 262 is formed to cover the top surface and side walls of the mesa shape and the top surface of the insulating layer 271. Then, as shown in Figure 10B, an insulating layer 273 is formed to cover the protective film 262. With these steps, the light-emitting element 20B is completed. 【0087】 Furthermore, the light-emitting element 20B of this modified example is manufactured in the same way as the light-emitting element 20A of modified example 4, by using an insulating film 26 made of, for example, nitrogen (N ２ The insulating film 26 may be removed after annealing in a gas atmosphere, for example, by wet etching. The subsequent manufacturing method is the same as the process described above. 【0088】 Except for the points mentioned above, the configuration of the light-emitting element 20B is substantially the same as the configuration of the light-emitting element 20 in the second embodiment. Even with this configuration, the light-emitting element 20B can obtain the same effects as in the second embodiment. 【0089】 [4-3. Modification 6] Figure 11 schematically shows an example of the cross-sectional configuration of a light-emitting element (light-emitting element 10D) according to Modification 6 of the present disclosure. The same reference numerals are used for the components corresponding to the light-emitting element 10 of the first embodiment described above, and their descriptions are omitted. 【0090】 The light-emitting element 10D of this modified example is a combination of the light-emitting element 10 of the first embodiment and the second embodiment. In the first embodiment, an example was shown in which a protective film 16 formed using aluminum oxide or the like is provided, but this disclosure is not limited thereto. 【0091】 In the modified light-emitting element 10D, a protective film 16d is provided so as to cover the sidewall of the compound semiconductor layer 11. The protective film 16d contains an oxide of a metal that has hydrogen storage properties. The protective film 16d contains a metal oxide with a band gap larger than that of the semiconductor material constituting the compound semiconductor layer 11. The oxide formation enthalpy of the metal oxide contained in the protective film 16d is smaller than the oxide formation enthalpy of the insulating layer 172. The protective film 16d is, for example, zirconium oxide (ZrO ２), magnesium oxide (MgO ２ It is formed using ) etc. 【0092】 Except for the points mentioned above, the configuration of the light-emitting element 10D is substantially the same as the configuration of the light-emitting element 10 in the first embodiment. In this way, by providing a protective film 16d containing an oxide of a hydrogen-storing metal so as to cover the side wall of the compound semiconductor layer 11 constituting the light-emitting element 10 in the first embodiment, it is possible to suppress the deactivation of the compound semiconductor layer 11 in addition to the effects of the first embodiment. 【0093】 <5. Third Embodiment> Figure 15 schematically shows an example of a cross-sectional configuration of a light-emitting device 2 equipped with a light-emitting element 30 according to the third embodiment of the present disclosure. Figure 16 schematically shows an example of a planar configuration of the light-emitting device 2 shown in Figure 15. Figure 16 shows the planar configuration of the light-emitting device 2 as seen from the first surface 11S1 side of the compound semiconductor layer 11, which will be described later. 【0094】 [5-1. Configuration of the Light-Emitting Device] In the light-emitting device 2, a plurality of light-emitting elements 30 are arranged in a two-dimensional array in the XY plane. The light-emitting device 2 is suitably applicable to image display devices known as LED displays (for example, the electronic viewfinder 1124 of a digital still camera 1120, see Figure 12B). 【0095】 The light-emitting element 30 has the same configuration as the light-emitting element 10 of the first embodiment described above. Specifically, the light-emitting element 30 is provided with a compound semiconductor layer 11, a first electrode 12, a second electrode 13, a first contact portion 14, a second contact portion 15, a protective film 16, an insulating layer 171, and an insulating layer 172. The sidewall of the compound semiconductor layer 11 is at an angle of 90° with respect to the XY plane, similar to the first modification described above. 【0096】 In the light-emitting device 2, a light-shielding structure 17 is provided between adjacent light-emitting elements 30. The light-shielding structure 17 corresponds to a "light-shielding structure" as one aspect of the present disclosure. 【0097】The light-shielding structure 17 is intended to suppress color mixing between adjacent light-emitting elements 30. The light-shielding structure 17 extends between a plurality of light-emitting elements 30 arranged in a two-dimensional array, as shown in Figure 16, for example, and is provided in a grid pattern in a plan view. Preferably, the light-shielding structure 17 protrudes upward (in the light extraction direction) above the first surface 11S1 of the light-emitting element 30, as shown in Figure 15, for example. This further suppresses color mixing between adjacent light-emitting elements 30. Furthermore, it allows for efficient extraction of light upward from the light-emitting elements 30. 【0098】 The light-shielding structure 17 is formed using a metallic material. Specifically, the light-shielding structure 17 can be formed using at least one of the following materials: aluminum (Al), tungsten (W), titanium (Ti), copper (Cu), tantalum (Ta), cobalt (Co), nickel (Ni), molybdenum (Mo), ruthenium (Ru), and iridium (Ir). 【0099】 [5-2. Function and Effects] The light-emitting device 2 of the third embodiment has a light-shielding structure 17 provided between adjacent light-emitting elements 30. This makes it possible to suppress color mixing between adjacent light-emitting elements 30. 【0100】 As described above, the light-emitting device 2 of the third embodiment makes it possible to reduce the decrease in resolution when multiple light-emitting elements 30 are mounted at a high density, in addition to the effects of the first embodiment. 【0101】 <6. Modifications> Next, modifications 7 to 10 of the third embodiment of the present disclosure will be described. The same reference numerals are used for the components corresponding to the light-emitting device 2 of the third embodiment, and their descriptions are omitted. 【0102】 [6-1. Modification 7] Figure 17 schematically shows an example of the cross-sectional configuration of the light-emitting device 2A according to Modification 7 of the present disclosure. Figure 18 schematically shows another example of the cross-sectional configuration of the light-emitting device 2A according to Modification 7 of the present disclosure. 【0103】In the third embodiment described above, an example was shown in which the sidewall of the compound semiconductor layer 11 is at an angle of 90° with respect to the XY plane, but the disclosure is not limited thereto. The sidewall of the compound semiconductor layer 11 may be inclined at an angle greater than 90° with respect to the XY plane, for example, as in the light-emitting device 2A shown in Figure 17. That is, the compound semiconductor layer 11 may have, for example, an inverse tapered shape. Alternatively, the sidewall of the compound semiconductor layer 11 may be inclined at an angle less than 90° with respect to the XY plane, for example, as in the light-emitting device 2A shown in Figure 18. That is, the compound semiconductor layer 11 may have, for example, a forward tapered shape. 【0104】 Except for the points mentioned above, the configuration of the light-emitting device 2A is substantially the same as the configuration of the light-emitting device 2 in the third embodiment described above. Even with this configuration, the light-emitting device 2A can obtain the same effects as in the third embodiment described above. 【0105】 [6-2. Modification 8] Figure 19 schematically shows an example of the cross-sectional configuration of the light-emitting device 2B according to Modification 8 of the present disclosure. Figure 20 schematically shows an example of the planar configuration of the light-emitting device 2B shown in Figure 19. Note that Figure 19 shows the planar configuration of the light-emitting device 2B as seen from the first surface 11S1 side of the compound semiconductor layer 11, which will be described later. 【0106】 In this modified light-emitting device 2B, a light-shielding structure 17 provided between adjacent light-emitting elements 30 is connected to the first electrode 12. The light-shielding structure 17 consists of a vertical section 17A and a horizontal section 17B. The vertical section 17A is provided between adjacent light-emitting elements 30. The horizontal section 17B is provided on the vertical section 17A and extends onto the first surface 11S1 of the light-emitting element 10. In other words, multiple light-emitting elements 10 arranged in a two-dimensional array are electrically connected to each other by the horizontal section 17B extending onto the first surface 11S1 of each light-emitting element 10. 【0107】 Except for the points mentioned above, the configuration of the light-emitting device 2B is substantially the same as the configuration of the light-emitting device 2 in the third embodiment described above. 【0108】Thus, in the light-emitting device 2B of this disclosure, a part of the light-shielding structure 17 (horizontal portion 17B) provided between adjacent light-emitting elements 30 is extended onto the first surface 11S1 of the light-emitting element 10, so that the number of vias 14V can be reduced, for example, as shown in Figure 20. As a result, the light-emitting device 2B can increase the light-emitting area compared to the light-emitting device 1 of the first embodiment described above. 【0109】 [6-3. Modification 9] Figure 21 schematically shows an example of the cross-sectional configuration of the light-emitting device 2C according to Modification 9 of the present disclosure. 【0110】 In the third embodiment described above, an example was shown in which a light-shielding structure 17 formed using a metallic material is provided between adjacent light-emitting elements 30, but the disclosure is not limited thereto. The light-shielding structure may be composed of an air gap G, for example, as shown in Figure 21. Alternatively, the light-shielding structure may be formed using a material with a lower refractive index than the surrounding material (for example, an insulating layer 171 embedded between adjacent light-emitting elements). 【0111】 Except for the points mentioned above, the configuration of the light-emitting device 2C is substantially the same as the configuration of the light-emitting device 2 in the third embodiment described above. 【0112】 As described above, in the light-emitting device 2C of this disclosure, a light-shielding structure (reflective structure) is provided between adjacent light-emitting elements 30, utilizing the difference in refractive index with the surrounding material. Even with this configuration, the light-emitting device 2C can obtain the same effects as the third embodiment described above. 【0113】 [6-4. Modification 10] Figure 22 schematically shows an example of the cross-sectional configuration of the light-emitting device 2D according to Modification 10 of the present disclosure. 【0114】In this modified light-emitting device 2D, dummy wiring 191 is provided within an insulating layer 172 that is provided to fill the space between the second electrode 13 and the first contact portion 14 of each of the multiple light-emitting elements 10 arranged in a two-dimensional array, and between the second electrode 13 and the second contact portion 15. The dummy wiring 191 is intended to prevent light emitted from the side opposite to the light-emitting side of the light-emitting element 10 from leaking to, for example, the drive substrate. The dummy wiring 191 is not connected to anything and is provided to cover the gap with, for example, the pad portions 14P and 15P in a plan view. The dummy wiring 191 can be formed using, for example, copper (Cu), aluminum (Al), tungsten (W), silver (Ag), or alloys thereof. 【0115】 Although Figure 22 shows an example in which a dummy wiring 191 is provided within the insulating layer 172, this disclosure is not limited to this. The dummy wiring 191 may be provided in the same layer as, for example, the pad portions 14P and 15P. 【0116】 Except for the points mentioned above, the configuration of the light-emitting device 2D is substantially the same as the configuration of the light-emitting device 2 in the third embodiment described above. Even with this configuration, the light-emitting device 2D can obtain the same effects as in the third embodiment described above. 【0117】 <7. Fourth Embodiment> Figure 23 schematically shows an example of a cross-sectional configuration of a light-emitting element 40 according to the fourth embodiment of the present disclosure. The light-emitting device equipped with the light-emitting element 40 is suitably applicable to an image display device called a so-called LED display (for example, an electronic viewfinder 1124 of a digital still camera 1120, see Figure 12B). 【0118】[7-1. Configuration of the Light-Emitting Device] The light-emitting device 40 has a configuration similar to, for example, the light-emitting device 20B of Modification 5 of the second embodiment described above. Specifically, the light-emitting device 40 is provided with a compound semiconductor layer 21, a first electrode 22, a second electrode 23, a first contact portion 24, a second contact portion 25, a protective film 262, an insulating layer 271, an insulating layer 272, an insulating layer 273, a contact layer 28, and a wiring layer 29. The light-emitting device 40 of this disclosure is further provided with a diffusion prevention layer 263 between the compound semiconductor layer 21 and the protective film 262 that covers the first surface 21S1 and the side wall of the compound semiconductor layer 21. Here, the diffusion prevention layer 263 corresponds to the "first layer" as one aspect of this disclosure. The protective film 262 corresponds to the "second layer" as one aspect of this disclosure. 【0119】 The protective film 262 contains an oxide of a metal that has hydrogen storage properties. Specifically, the protective film 262 is formed using, for example, aluminum oxide (AlO). In addition, the protective film 262 may be formed using oxides such as hafnium oxide (HfO), zirconium oxide (ZrO), and silicon oxide (SiO). 【0120】 The diffusion prevention layer 263 is intended to prevent the diffusion of metal atoms and oxygen atoms at the interface between the compound semiconductor layer 21 and the oxide film (e.g., protective film 262) in a configuration where the compound semiconductor layer 21 and the oxide film (e.g., protective film 262) are in direct contact, as in the modified example 5 described above. The diffusion prevention layer 263 is provided so as to cover the first surface 21S1 and the side walls of the compound semiconductor layer 21. Furthermore, the diffusion prevention layer 263 extends along the surface of the insulating layer 271 that is in contact with the second electrode 23. 【0121】 The diffusion prevention layer 263 is preferably formed using a nitride from the viewpoint of heat resistance, oxidation resistance, and diffusion prevention of metal atoms. Specifically, the diffusion prevention layer 263 is preferably formed using a nitride with a diffusion coefficient of metal atoms contained in the protective film 262 of 1.00E-06m. ２It can be formed using nitrides with a capacitance of 0 / s or less. Examples of such nitrides include aluminum nitride (AlN), gallium nitride (GaN), silicon nitride (SiN), boron nitride (BN), titanium nitride (TiN), and tantalum nitride (TaN). The diffusion prevention layer 263 preferably has a thickness of 20 μm or more. This prevents metal atoms and oxygen atoms from the protective film 262 from diffusing into the compound semiconductor layer 21 when current is applied. ｘ Formation is suppressed. 【0122】 In the light-emitting element 40, a common electrode 291 and an insulating layer 274 are further provided on the insulating layer 273. 【0123】 In a light-emitting device where multiple light-emitting elements are arranged in a two-dimensional array, the common electrode 291 is used to apply a voltage to the first electrode 22 of each of the multiple light-emitting elements 40. The common electrode 291 is connected to the first electrode 22 via an opening H3 that penetrates the diffusion prevention layer 263, protective film 262, and insulating layer 273 formed on each light-emitting element 40. The common electrode 291 is further connected to the contact layer 28 via a part of the insulating layer 271, as well as via an opening H4 that penetrates the diffusion prevention layer 263, protective film 262, and insulating layer 273. 【0124】 The common electrode 291, like the first electrode 22, is formed from a transparent electrode material such as ITO, indium zinc oxide (IZO), tin oxide (SnO), or TiO. The contact layer 28 has a laminated structure of, for example, a metal layer 281 and a base layer 282. The metal layer 281 is formed using, for example, aluminum (Al), silver (Ag), tantalum (Ta), titanium (Ti), tungsten (W), molybdenum (Mo), copper (Cu), gold (Ag), platinum (Pt), palladium (Pd), nickel (Ni), and alloys mainly composed of these materials. The base layer 282 is formed using, for example, titanium (Ti), tantalum (Ta), tungsten (W), cobalt (Co), or molybdenum (Mo), or alloys, nitrides, oxides, or carbides thereof. 【0125】[7-2. Function and Effects] The light-emitting element 40 of the fourth embodiment has a diffusion prevention layer 263 provided between the compound semiconductor layer 21 and the protective film 262 that covers the first surface 21S1 and the side wall of the compound semiconductor layer 21. As a result, GaO generated when current is applied ｘ Formation is suppressed. 【0126】 As described above, the light-emitting element 40 of the fourth embodiment has the effect of the second embodiment, in addition to GaO ｘ This makes it possible to reduce the decrease in luminous efficiency caused by the formation of [unclear]. 【0127】 <8. Modifications> Next, modifications 11 and 12 of the fourth embodiment of the present disclosure will be described. The same reference numerals are used for the components corresponding to the light-emitting element 40 of the fourth embodiment, and their descriptions are omitted. 【0128】 [8-1. Modification 11] Figure 24 schematically shows an example of the cross-sectional configuration of the light-emitting element 40A according to Modification 11 of the present disclosure. 【0129】 In the fourth embodiment described above, an example was shown in which the diffusion prevention layer 263 and the protective film 262 extend from the side wall of the compound semiconductor layer 21 to the surface in contact with the first surface 21S1 of the compound semiconductor layer 21 and the second electrode 23 of the insulating layer 271, but the disclosure is not limited thereto. In this modified light-emitting element 40A, the diffusion prevention layer 263 is selectively provided on the side wall of the compound semiconductor layer 21, and the protective film 262 extends only to the side wall of the compound semiconductor layer 21 and the surface in contact with the second electrode 23 of the insulating layer 271. 【0130】 Except for the points mentioned above, the configuration of the light-emitting element 40A is substantially the same as the configuration of the light-emitting element 40 in the fourth embodiment described above. Even with this configuration, the light-emitting element 40A can obtain the same effects as in the fourth embodiment described above. 【0131】 [8-2. Modification 12] Figure 25 schematically shows an example of the cross-sectional configuration of the light-emitting element 40B according to Modification 12 of the present disclosure. 【0132】In the fourth embodiment described above, an example was shown in which the diffusion prevention layer 263 is formed using a nitride, but the disclosure is not limited thereto. In this modified example, the light-emitting element 40B has a diffusion prevention layer 263 formed by voids G. 【0133】 Furthermore, if the diffusion prevention layer is formed by air gaps G, although not shown in the figures, a spacer is formed between the surface of the insulating layer 271 that is in contact with the second electrode 23 and the protective film 262 to maintain the air gaps G. 【0134】 Except for the points mentioned above, the configuration of the light-emitting element 40B is substantially the same as the configuration of the light-emitting element 40 in the fourth embodiment. Even with this configuration, the light-emitting element 40B can obtain the same effects as in the fourth embodiment. 【0135】 <9. Application Examples> (Application Example 1) Figure 12A is a front view showing an example of the external appearance of a digital still camera (electronic device) 1120. Figure 12B is a rear view showing an example of the external appearance of a digital still camera 1120. The digital still camera 1120 is a single-lens reflex type with interchangeable lenses. The digital still camera 1120 has an interchangeable shooting lens unit (interchangeable lens) 1121 located approximately in the center of the front of the camera body 1122, and a grip portion 1123 for the photographer to hold on the left side of the front. 【0136】 A monitor 1126 is located slightly to the left of the center of the back of the camera body 1122. An electronic viewfinder (eyepiece) 1124 is located above the monitor 1126. The photographer can determine the composition by looking through the electronic viewfinder 1124 and viewing the light image of the subject guided by the photographic lens unit 1121. The electronic viewfinder 1124 is equipped with a light-emitting device 1. 【0137】(Application Example 2) The light-emitting device of this disclosure (for example, light-emitting device 1) is also applicable to a head-mounted display (hereinafter referred to as HMD). The head-mounted display 1130A can be used for VR (Virtual Reality), AR (Augmented Reality), MR (Mixed Reality), or SR (Substantial Reality), etc. 【0138】 Figure 13A is a perspective view showing the external appearance of a head-mounted display (electronic device) 1130A. The head-mounted display 1130A has, for example, a glasses-shaped display unit 1132 with ear hooks 1131 on both sides for attachment to the user's head. The display unit 1132 is equipped with a light-emitting device 1. 【0139】 Figure 13B is a perspective view showing the appearance of another head-mounted display (electronic device). The head-mounted display is a smart glasses 1130B that displays various information on eyeglasses 1133. The smart glasses 1130B comprises a main body, an arm 1135, and a lens barrel 1136. The main body 1134 is connected to the arm 1135. The main body 1134 is detachable from the eyeglasses 1133. The main body 1134 contains a control board and a display unit for controlling the operation of the smart glasses 1130B. The main body 1134 and the lens barrel 1136 are connected to each other via the arm 1135. The lens barrel 1136 emits image light emitted from the main body 1134 via the arm 1135 towards the lens 1137 of the eyeglasses 1133. This image light enters the human eye through the lens 1137. As shown in Figure 13B, the wearer of the smart glasses 1130B can see not only the surrounding environment but also various information emitted from the lens barrel 1136, just like with regular glasses. The main body 1134 is equipped with a light-emitting device 1. 【0140】 (Application Example 3) Figure 14 is a perspective view showing an example of the appearance of a television device (electronic device) 1140. This television device 1140 has, for example, a video display screen section 1141 including a front panel 1142 and a filter glass 1143. The video display screen section 1141 is equipped with a light-emitting device 1. 【0141】 The present technology has been described above with reference to the first to fourth embodiments, modifications 1 to 12, and application examples. However, the present technology is not limited to the above embodiments, and various modifications are possible. For example, the above embodiments show examples in which the light emitted from the light-emitting element 10 is blue light or ultraviolet light, but the technology is not limited to these. For example, the light-emitting device 1 can also use a light-emitting element that emits two or more types of light, such as blue light and green light, or ultraviolet light and green light. 【0142】 Furthermore, although the above embodiments have described the components constituting the light-emitting device 1, etc., it is not necessary to include all components, and other components may also be included. 【0143】 Furthermore, the effects described herein are merely examples and are not limited to those described; other effects may also occur. 【0144】The present technology can also take the following configurations. According to the present technology with the following configurations, the first contact portion is provided inside the compound semiconductor layer, so that the distances between the first contact electrode and the light-emitting elements become uniform in a light-emitting device equipped with a plurality of such light-emitting elements. This makes it possible to provide a light-emitting device with uniform light emission intensity in plane. (1) A light-emitting element comprising: a compound semiconductor layer having a first surface which is a light-emitting surface and a second surface opposite to the first surface, and including an active layer that emits light; a first electrode provided so as to cover the first surface of the compound semiconductor layer; a second electrode provided on the side of the second surface of the compound semiconductor layer; a first contact portion that penetrates the active layer and is electrically connected to the first electrode; and a second contact portion that is electrically connected to the second electrode. (2) The light-emitting element according to (1) above, wherein the first contact portion penetrates at least a part of the side wall of the active layer. (3) The light-emitting element according to (1) or (2) above, wherein the area of ​​the second electrode is smaller than the area of ​​the first electrode. (4) The light-emitting element according to (3) above, wherein the first contact portion is connected to the first electrode in a region that does not overlap with the second electrode in a first direction. (5) The light-emitting element according to any one of (1) to (4) above, wherein the first contact portion comprises at least one of indium tin oxide, indium oxide, indium zinc oxide, indium-gallium-zinc oxide, titanium, titanium nitride, and tungsten. (6) The light-emitting element according to any one of (1) to (5) above, wherein the diameter of the first contact portion is 100 nm or more and 300 nm or less. (7) The light-emitting element according to any one of (1) to (6) above, wherein the compound semiconductor layer comprises a first conductivity type layer, the active layer, and a second conductivity type layer in order from the second surface side. (8) The light-emitting element according to (7) above, wherein the first conductivity type layer is formed of an n-type GaN-based semiconductor material, and the second conductivity type layer is formed of a p-type GaN-based semiconductor material. (9) The light-emitting element according to any one of (1) to (8) above, further comprising an insulating film that covers the first surface and sidewall of the compound semiconductor layer and contains an oxide of a metal having hydrogen storage properties.(10) The light-emitting element according to (9) above, wherein the insulating film comprises a metal oxide having a band gap larger than that of the semiconductor material constituting the compound semiconductor layer. (11) The light-emitting element according to (9) or (10) above, wherein the insulating film comprises an oxide of zirconium and magnesium. (12) The light-emitting element according to any one of (1) to (11) above, further comprising a protective film covering the first surface and sidewall of the compound semiconductor layer. (13) The light-emitting element according to (12) above, wherein the protective film comprises at least one of silicon oxide, silicon nitride, and aluminum oxide. (14) The light-emitting element according to (12) or (13) above, wherein the oxide formation enthalpy of the metal oxide contained in the insulating film is smaller than the oxide formation enthalpy of the protective film. (15) The light-emitting element according to claim 1, further comprising an insulating film having a multilayer structure that covers at least a portion of the first surface and sidewall of the compound semiconductor layer, wherein the insulating film comprises, in order from a position close to the compound semiconductor layer, a first layer formed of a nitride and a second layer formed of an oxide. (16) The light-emitting element according to claim 15, wherein the first layer has a film thickness of 20 μm or more. (17) The first layer has a diffusion coefficient of metal atoms contained in the compound semiconductor layer of 1.00E-06 m. ２(18) The light-emitting element according to claim 15, wherein the first layer is formed of a nitride with a time interval of 0 / s or less. (19) The light-emitting element according to claim 15, wherein the second layer comprises an oxide. (20) The light-emitting element according to claim 15, wherein the insulating film is selectively provided on the side wall of the compound semiconductor layer. (21) A light-emitting device comprising a plurality of light-emitting elements, each of which comprises: a compound semiconductor layer having a first surface that is a light-emitting surface and a second surface opposite to the first surface, and including an active layer that emits light; a first electrode provided so as to cover the first surface of the compound semiconductor layer; a second electrode provided on the second surface side of the compound semiconductor layer; a first contact portion that penetrates the active layer and is electrically connected to the first electrode; and a second contact portion that is electrically connected to the second electrode. (22) The light-emitting device according to (21), wherein the plurality of light-emitting elements are arranged in a two-dimensional array, and further comprising a light-shielding structure between adjacent light-emitting elements. (23) The light-emitting device according to (22) above, wherein the light-shielding structure is formed using a metallic material. (24) The light-emitting device according to (22) or (23) above, wherein the light-shielding structure comprises at least one of aluminum, tungsten, titanium, copper, tantalum, cobalt, nickel, molybdenum, ruthenium, and iridium. (25) The light-emitting device according to any one of (22) to (24) above, wherein the light-shielding structure is connected to the first electrode. (26) The light-emitting device according to any one of (22) to (25) above, wherein the light-shielding structure is formed of a material with a lower refractive index than the void or the surrounding member. (27) An image display device comprising a light-emitting element, the light-emitting element having a first surface which is a light-emitting surface and a second surface opposite to the first surface, and a compound semiconductor layer including a light-emitting active layer, a first electrode provided so as to cover the first surface of the compound semiconductor layer, a second electrode provided on the second surface side of the compound semiconductor layer, a first contact portion that penetrates the active layer and is electrically connected to the first electrode, and a second contact portion that is electrically connected to the second electrode.(28) The image display device according to (27) above, comprising a plurality of the light-emitting elements, wherein the distance between the first contact portion and the second contact portion of each of the plurality of light-emitting elements is substantially the same. (29) The image display device according to (27) or (28) above, comprising a plurality of light-emitting elements, wherein the plurality of light-emitting elements share a first contact portion that penetrates at least a portion of the sidewall of each of the active layer. (30) A light-emitting element comprising a compound semiconductor layer having a first surface that becomes a light-emitting surface, and an insulating film covering the first surface and sidewall of the compound semiconductor layer and containing an oxide of a metal having hydrogen-absorbing properties. (31) An image display device comprising a light-emitting element, wherein the light-emitting element comprises a compound semiconductor layer having a first surface that becomes a light-emitting surface, and an insulating film covering the first surface and sidewall of the compound semiconductor layer and containing an oxide of a metal having hydrogen-absorbing properties. (32) A method for manufacturing a light-emitting element, comprising forming a compound semiconductor layer, forming a metal film covering the first surface and sidewall of the compound semiconductor layer and having hydrogen-absorbing properties, and oxidizing the metal film to form an insulating film. (33) A method for manufacturing a light-emitting element, comprising forming a compound semiconductor layer and forming an insulating film that covers the first surface and side walls of the compound semiconductor layer and contains an oxide of a metal having hydrogen storage properties. 【0145】 This application claims priority based on Japanese Patent Application No. 2024-216546, filed with the Japan Patent Office on 11 December 2024, and all contents of that application are incorporated herein by reference. 【0146】 Those skilled in the art will understand that various modifications, combinations, subcombinations, and changes can be conceived depending on design requirements and other factors, and that these fall within the scope of the attached claims and their equivalents.

Claims

1. A light-emitting element comprising: a compound semiconductor layer having a first surface that serves as a light-emitting surface and a second surface opposite to the first surface, and including an active layer that emits light; a first electrode provided so as to cover the first surface of the compound semiconductor layer; a second electrode provided on the second surface side of the compound semiconductor layer; a first contact portion that penetrates the active layer and is electrically connected to the first electrode; and a second contact portion that is electrically connected to the second electrode.

2. The light-emitting element according to claim 1, wherein the first contact portion penetrates at least a portion of the side wall of the active layer.

3. The light-emitting element according to claim 1, wherein the area of ​​the second electrode is smaller than the area of ​​the first electrode.

4. The light-emitting element according to claim 3, wherein the first contact portion is connected to the first electrode in a region that does not overlap with the second electrode in a first direction.

5. The light-emitting element according to claim 1, wherein the first contact portion comprises at least one of indium tin oxide, indium oxide, indium zinc oxide, indium-gallium-zinc oxide, titanium, titanium nitride, and tungsten.

6. The light-emitting element according to claim 1, wherein the diameter of the first contact portion is 100 nm or more and 300 nm or less.

7. The light-emitting element according to claim 1, wherein the compound semiconductor layer comprises a first conductivity type layer, the active layer, and the second conductivity type layer in order from the second surface side.

8. The light-emitting element according to claim 7, wherein the first conductivity type layer is formed of an n-type GaN-based semiconductor material, and the second conductivity type layer is formed of a p-type GaN-based semiconductor material.

9. The light-emitting element according to claim 1, further comprising an insulating film that covers the first surface and sidewall of the compound semiconductor layer and contains an oxide of a metal having hydrogen storage properties.

10. The light-emitting element according to claim 9, wherein the insulating film includes a metal oxide with a band gap larger than that of the semiconductor material constituting the compound semiconductor layer.

11. The light-emitting element according to claim 9, wherein the insulating film comprises an oxide of zirconium and magnesium.

12. The light-emitting element according to claim 9, further comprising a protective film covering the first surface and sidewall of the compound semiconductor layer.

13. The light-emitting element according to claim 12, wherein the protective film comprises at least one of silicon oxide, silicon nitride, and aluminum oxide.

14. The light-emitting element according to claim 12, wherein the enthalpy of oxide formation of the metal oxide contained in the insulating film is smaller than the enthalpy of oxide formation of the protective film.

15. The light-emitting element according to claim 1, further comprising an insulating film having a multilayer structure that covers at least a portion of the first surface and sidewall of the compound semiconductor layer, wherein the insulating film comprises, in order from a position close to the compound semiconductor layer, a first layer formed of a nitride and a second layer formed of an oxide.

16. The light-emitting element according to claim 15, wherein the first layer has a film thickness of 20 μm or more.

17. The first layer has a diffusion coefficient of 1.00E-06m of metal atoms contained in the second layer. ２ The light-emitting element according to claim 15, which is formed by the nitride with a coefficient of / s or less.

18. The light-emitting element according to claim 15, wherein the first layer is formed by a void.

19. The light-emitting element according to claim 15, wherein the insulating film is selectively provided on the sidewall of the compound semiconductor layer.

20. A light-emitting device comprising a plurality of light-emitting elements, each of which has a first surface that serves as a light-emitting surface and a second surface opposite to the first surface, and includes a compound semiconductor layer containing a light-emitting active layer, a first electrode provided so as to cover the first surface of the compound semiconductor layer, a second electrode provided on the second surface side of the compound semiconductor layer, a first contact portion that penetrates the active layer and is electrically connected to the first electrode, and a second contact portion that is electrically connected to the second electrode.

21. The light-emitting device according to claim 20, wherein the plurality of light-emitting elements are arranged in a two-dimensional array, and further comprising a light-shielding structure between adjacent light-emitting elements.

22. The light-emitting device according to claim 21, wherein the light-shielding structure is formed using a metal material.

23. The light-emitting device according to claim 21, wherein the light-shielding structure comprises at least one of aluminum, tungsten, titanium, copper, tantalum, cobalt, nickel, molybdenum, ruthenium, and iridium.

24. The light-emitting device according to claim 21, wherein the light-shielding structure is connected to the first electrode.

25. The light-emitting device according to claim 21, wherein the light-shielding structure is formed of a material having a lower refractive index than the void or the surrounding member.

26. An image display device comprising a light-emitting element, the light-emitting element having a first surface that is a light-emitting surface and a second surface opposite to the first surface, and a compound semiconductor layer including a light-emitting active layer, a first electrode provided so as to cover the first surface of the compound semiconductor layer, a second electrode provided on the second surface side of the compound semiconductor layer, a first contact portion that penetrates the active layer and is electrically connected to the first electrode, and a second contact portion that is electrically connected to the second electrode.

27. The image display device according to claim 26, wherein the plurality of light-emitting elements are provided, and the distance between the first contact portion and the second contact portion of each of the plurality of light-emitting elements is substantially the same.

28. The image display device according to claim 26, comprising a plurality of light-emitting elements, wherein the plurality of light-emitting elements share the first contact portion that penetrates at least a portion of the side wall of each of the active layers.

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