Light-emitting element

Abstract

Provided is a light-emitting element configured so that, when individually controlling the light emission of a plurality of light-emitting parts, it is possible to reduce the extraction of light emitted by the light-emitting parts from regions other than a region above the light-emitting parts that emit light. 　This light-emitting element comprises: a semiconductor structure including an n-side semiconductor layer and a plurality of light-emitting parts, the n-side semiconductor layer having a first surface, a plurality of second surfaces positioned on the side opposite the first surface, and a third surface positioned on the side opposite the first surface, and the plurality of light-emitting parts each having an active layer and a p-side semiconductor layer disposed on the second surface, wherein the third surface is positioned between the plurality of light-emitting parts in plan view and is exposed from the active layer and the p-side semiconductor layer; an n-side electrode disposed on the third surface; and p-side electrodes disposed on each of the p-side semiconductor layers of the plurality of light-emitting parts and electrically connected to the p-side semiconductor layers. In plan view: the first surface has a first region and a second region having an arithmetic average roughness smaller than that of the first region; the first region overlaps the second surface; and the second region overlaps the third surface.

Description

Light-emitting element

[0001] The present invention relates to a light-emitting device.

[0002] For example, Patent Document 1 discloses a configuration in which a groove is formed in a semiconductor laminate that extends from the second semiconductor layer side through the second semiconductor layer and active region to reach the first semiconductor layer, and multiple segments divided by the groove can be made to emit light individually.

[0003] Special table 2016-513876 publication

[0004] The present invention aims to provide a light-emitting element that can reduce the amount of light emitted by a light-emitting element being extracted from areas other than the area on the light-emitting element that is the target of light emission when the light emission of multiple light-emitting elements is controlled individually.

[0005] According to one aspect of the present invention, a light-emitting element is a semiconductor structure including: an n-side semiconductor layer having a first surface, a plurality of second surfaces located opposite the first surface, and a third surface located opposite the first surface; and a plurality of light-emitting units each having an active layer and a p-side semiconductor layer arranged on each of the plurality of second surfaces, wherein the third surface is located between the plurality of light-emitting units in a plan view and is exposed from the active layer and the p-side semiconductor layer; an n-side electrode arranged on the third surface and electrically connected to the n-side semiconductor layer; and a p-side electrode arranged on each of the p-side semiconductor layers of the plurality of light-emitting units and electrically connected to the p-side semiconductor layer, wherein, in a plan view, the first surface has a first region and a second region having an arithmetic mean roughness smaller than that of the first region, and the first region overlaps the second surface, and the second region overlaps the third surface.

[0006] According to the present invention, it is possible to provide a light-emitting element that can reduce the amount of light emitted by the light-emitting elements being extracted from areas other than the area on the light-emitting element that is the target of light emission when the light-emitting elements are individually controlled to emit light.

[0007] 5A is a schematic plan view of a light-emitting element according to an embodiment. FIG. 5B is a schematic plan view of a light-emitting element according to an embodiment. FIG. 5C is a schematic plan view of a light-emitting element according to an embodiment. FIG. 5C is a schematic cross-sectional view taken along line III-III in FIG. 1. FIG. 5A is a schematic plan view of a light-emitting element according to a first modified example of the embodiment. FIG. 5C is a schematic cross-sectional view of a light-emitting element according to a second modified example of the embodiment. FIG. 5C is a schematic cross-sectional view of a light-emitting element according to a third modified example of the embodiment. FIG. 5B is a schematic cross-sectional view taken along line VB-VB in FIG. 5A. FIG. 5C is a schematic cross-sectional view of a light-emitting element according to an embodiment. FIG. 5C is a schematic cross-sectional view of a light-emitting element according to an embodiment. FIG. 5C is a schematic cross-sectional view of a light-emitting element according to an embodiment. FIG. 5C is a schematic cross-sectional view of a light-emitting element according to an embodiment. FIG. 5C is a schematic cross-sectional view illustrating one step of a manufacturing method for a light-emitting element according to an embodiment. FIG. 5D is a schematic cross-sectional view illustrating one step of a manufacturing method for a light-emitting element according to an embodiment. FIG. 5E is a schematic plan view illustrating one step of a manufacturing method for a light-emitting element according to an embodiment. FIG. 5F is a schematic cross-sectional view taken along line VP-VP of FIG. 5O. FIG. 5G is a schematic cross-sectional view illustrating one step of a manufacturing method for a light-emitting element according to an embodiment. FIG. 5G is a schematic cross-sectional view illustrating one step of a manufacturing method for a light-emitting element according to an embodiment.

[0008] Hereinafter, embodiments will be described with reference to the drawings. The dimensions, materials, shapes, relative positions, and the like of components described in the embodiments are not intended to be limiting unless otherwise specified, and are merely illustrative examples. The sizes and positional relationships of components shown in each drawing may be exaggerated for clarity. In the following description, the same names and symbols indicate the same or similar components, and detailed descriptions will be omitted as appropriate. Cross-sectional views may also be shown as end views showing only the cut surface.

[0009] In the following description, terms indicating specific directions or positions (e.g., "above," "below," and other terms including these terms) may be used. However, these terms are used merely to facilitate understanding of relative directions or positions in the referenced drawings. As long as the relative direction or position relationship indicated by terms such as "above" and "below" in the referenced drawings is the same, the arrangement in drawings other than those disclosed herein, actual products, etc., does not have to be the same as in the referenced drawings. In this specification, the positional relationship expressed as "above (or below)" includes, for example, when two components are assumed to exist, a case in which the two components are in contact with each other, and a case in which the two components are not in contact with each other and one component is located above (or below) the other component. Furthermore, unless otherwise specified, a component covering a target to be covered includes a case in which the component is in contact with the target to be covered directly and a case in which the component is not in contact with the target to be covered indirectly. In this specification, "planar view" means observing the light-emitting element 1 from the first surface 11A side or the second surface 11B side of the semiconductor structure 10.

[0010] In the drawings shown below, directions may be indicated by the X-axis, Y-axis, and Z-axis. The X-axis, Y-axis, and Z-axis are perpendicular to each other. For example, in this specification, the direction along the X-axis is referred to as the first direction X, the direction along the Y-axis is referred to as the second direction Y, and the direction along the Z-axis is referred to as the third direction Z.

[0011] A light-emitting element 1 according to an embodiment will be described with reference to Figures 1 to 3. The light-emitting element 1 according to the embodiment includes a semiconductor structure 10, an n-side electrode 21, and a p-side electrode 22. Each component will be described below.

[0012] [Semiconductor Structure 10] The semiconductor structure 10 is made of a nitride semiconductor. In this specification, the term "nitride semiconductor" refers to, for example, In ｘ Al ｙ Ga １－ｘ－ｙ The term "nitride semiconductor" includes all semiconductors with compositions in which the composition ratios x and y in the chemical formula N (0≦x≦1, 0≦y≦1, x+y≦1) are varied within their respective ranges. Furthermore, in the above chemical formula, those that further contain a Group V element other than N (nitrogen) and those that further contain various elements added to control various physical properties such as conductivity type are also included in the term "nitride semiconductor."

[0013] As shown in FIG. 3 , the semiconductor structure 10 includes an n-side semiconductor layer 11. The n-side semiconductor layer 11 includes a semiconductor layer containing n-type impurities. The n-side semiconductor layer 11 includes a first surface 11A, a plurality of second surfaces 11B, and a third surface 11C. The second surface 11B and the third surface 11C are located on opposite sides of the first surface 11A in the third direction Z. The shape of the first surface 11A in plan view can be, for example, a quadrangular shape such as a square or a rectangle. The shape of the first surface 11A in plan view can also be a substantially square or rectangular shape with at least one corner chamfered. When the shape of the first surface 11A in plan view is square, the length of one side of the first surface 11A can be, for example, 5 μm to 200 μm, preferably 10 μm to 100 μm. The thickness of the n-side semiconductor layer 11 can be, for example, 1 μm to 6 μm. The thickness of the n-side semiconductor layer 11 is the maximum thickness of the n-side semiconductor layer 11 in the third direction Z.

[0014] The semiconductor structure 10 has a plurality of light-emitting portions 100, each having an active layer 12 and a p-side semiconductor layer 13 arranged on each of a plurality of second surfaces 11B. The active layer 12 is located between the second surface 11B of the n-side semiconductor layer 11 and the p-side semiconductor layer 13 in the third direction Z. The p-side semiconductor layer 13 includes a semiconductor layer containing p-type impurities. The active layer 12 is a light-emitting layer that emits light and has, for example, an MQW (Multiple Quantum Well) structure including multiple barrier layers and multiple well layers. The active layer 12 emits light having, for example, a peak wavelength of 210 nm or more and 580 nm or less. The semiconductor structure 10 also has a side surface 10C. The side surface 10C connects the first surface 11A of the n-side semiconductor layer 11 to a fourth surface 13A of the p-side semiconductor layer 13, which is located on the opposite side of the active layer 12.

[0015] 2A, the third surface 11C of the n-side semiconductor layer 11 is located between the plurality of light emitting sections 100 in a plan view. As shown in Fig. 3, the third surface 11C is exposed from the active layer 12 and the p-side semiconductor layer 13.

[0016] The p-side electrode 22, which will be described later, is electrically connected to each of the light-emitting units 100 and functions as an anode electrode that supplies current to the light-emitting units 100. The n-side electrode 21, which will be described later and is disposed on the third surface 11C, functions as a cathode electrode common to the light-emitting units 100. By supplying current to the p-side electrode 22 corresponding to the light-emitting unit 100 to be emitted, the light emission of the multiple light-emitting units 100 can be individually controlled. For a given area of ​​the light-emitting element 1 in a planar view, using one n-side electrode 21 electrically connected to each of the multiple light-emitting units 100 can reduce the area of ​​the third surface 11C in a planar view compared to a light-emitting element having multiple n-side electrodes 21 electrically connected to each of the multiple light-emitting units 100. In other words, by reducing the area where the n-side electrode 21 is disposed in a planar view, the area of ​​the light-emitting unit 100 in a planar view can be increased, thereby improving the luminance of the light-emitting element 1.

[0017] As shown in FIG. 1 , in a plan view, the first surface 11A of the n-side semiconductor layer 11 has a plurality of first regions 11A1 and one second region 11A2. In a plan view, the second region 11A2 is located between the plurality of first regions 11A1. The total area of ​​the plurality of first regions 11A1 is larger than the area of ​​the second region 11A2. Light emitted by the active layer 12 is extracted to the outside of the semiconductor structure 10 mainly from the first region 11A1. The arithmetic mean roughness of the second region 11A2 is smaller than that of the first region 11A1. Conversely, the arithmetic mean roughness of the first region 11A1 is larger than that of the second region 11A2. This can improve the light extraction efficiency from the first region 11A1. The first region 11A1 is a region that has been roughened by dry etching or wet etching, as described below, and the second region 11A2 is a region that has not been roughened by such a roughening treatment. For example, the arithmetic mean roughness of the first region 11A1 is 100 nm or more and 1000 nm or less, and the arithmetic mean roughness of the second region 11A2 is 50 nm or less.

[0018] In a plan view, the first region 11A1 overlaps the second surface 11B. A light emitting unit 100 having an active layer 12 is disposed on the second surface 11B. Therefore, in a plan view, the first region 11A1 overlaps the light emitting unit 100. As a result, light emitted by the active layer 12 is efficiently extracted from the first region 11A1.

[0019] In a plan view, the second region 11A2 overlaps the third surface 11C. In the third direction Z, the portion of the semiconductor structure 10 between the third surface 11C and the second region 11A2 does not include the light emitting unit 100. Therefore, the amount of light extracted from the second region 11A2 is less than the amount of light extracted from the first region 11A1. Furthermore, by making the arithmetic mean roughness of the second region 11A2 smaller than that of the first region 11A1, light emitted from the active layer 12 can be more easily totally reflected in the second region 11A2. For example, assume that light emission control is performed in which one light emitting unit 100C of the two light emitting units 100 in FIG. 3 is activated and the other light emitting unit 100B is not activated. In this case, the light emitted by one light emitting unit 100C is totally reflected in the second region 11A2, reducing the amount of light extracted from the first region 11A1 on the second region 11A2 and the other light emitting unit 100B. Therefore, when the light emission of the plurality of light-emitting units 100 is individually controlled, it is possible to reduce the amount of light emitted by the light-emitting units 100 being extracted from anywhere other than the first region 11A1 on the light-emitting unit 100 that is the light-emitting target. By increasing the difference in brightness between the light-emitting unit 100 that is the light-emitting target and the light-emitting unit that is not the light-emitting target, it is possible to accentuate the contrast between light and dark.

[0020] In a plan view, the second region 11A2 may not overlap the second surface 11B. In this case, the area where the first region 11A1 overlaps the second surface 11B in a plan view can be relatively increased, thereby improving the luminance of the light-emitting element 1.

[0021] In a plan view, a part of the second region 11A2 may overlap with the second surface 11B. In this case, the light emitted by the light-emitting unit 100 is more likely to be totally reflected by the second region 11A2, which reduces the amount of light extracted from regions other than the first region 11A1 on the light-emitting unit 100 that is emitting light.

[0022] 1 to 3, the semiconductor structure 10 has four light-emitting sections 100. As shown in FIG. 1, the four light-emitting sections 100 include a first light-emitting section 100A, a second light-emitting section 100B, a third light-emitting section 100C, and a fourth light-emitting section 100D. The second light-emitting section 100B is adjacent to the first light-emitting section 100A in the first direction X. The third light-emitting section 100C is adjacent to the first light-emitting section 100A in the second direction Y. The fourth light-emitting section 100D is adjacent to the third light-emitting section 100C in the first direction X and adjacent to the second light-emitting section 100B in the second direction Y.

[0023] In a plan view, the first region 11A1 overlaps the first light-emitting unit 100A, the second light-emitting unit 100B, the third light-emitting unit 100C, and the fourth light-emitting unit 100D. The shape of the first region 11A1 in a plan view can be, for example, a quadrilateral shape such as a square or a rectangle. Note that the shape of the first surface 11A in a plan view may be a substantially square or a substantially rectangular shape with at least one corner chamfered. When the shape of the first region 11A1 in a plan view is a square, the length of one side of the first region 11A1 can be, for example, 10 μm or more and 70 μm or less, preferably 15 μm or more and 50 μm or less.

[0024] In a plan view, the second region 11A2 is located between the first light-emitting unit 100A and the second light-emitting unit 100B, between the first light-emitting unit 100A and the third light-emitting unit 100C, between the third light-emitting unit 100C and the fourth light-emitting unit 100D, and between the second light-emitting unit 100B and the fourth light-emitting unit 100D. The second region 11A2 is also located in a central portion including the center of the light-emitting element 1 in a plan view. The second region 11A2 is located in the central portion of the light-emitting element 1, between the first light-emitting unit 100A and the fourth light-emitting unit 100D, and between the second light-emitting unit 100B and the third light-emitting unit 100C.

[0025] 2A , in a plan view, the third surface 11C is located between the first light-emitting unit 100A and the second light-emitting unit 100B, between the first light-emitting unit 100A and the third light-emitting unit 100C, between the third light-emitting unit 100C and the fourth light-emitting unit 100D, and between the second light-emitting unit 100B and the fourth light-emitting unit 100D. The third surface 11C is located in the center of the light-emitting element 1 in a plan view. The third surface 11C is located in the center of the light-emitting element 1, between the first light-emitting unit 100A and the fourth light-emitting unit 100D, and between the second light-emitting unit 100B and the third light-emitting unit 100C. In a plan view, the width of the third surface 11C located between adjacent light-emitting units 100 can be 2 μm or more and 10 μm or less.

[0026] The first surface 11A of the n-side semiconductor layer 11 may further include a third region 11A3. As shown in FIG. 1 , the third region 11A3 continuously surrounds the first region 11A1 and the second region 11A2 in a planar view. In a planar view, the third region 11A3 overlaps the second surface 11B. The arithmetic mean roughness of the third region 11A3 is smaller than that of the first region 11A1 and is approximately the same as that of the second region 11A2. The third region 11A3 does not necessarily have to be provided. When the third region 11A3 is not provided, the region where the third region 11A3 is provided in FIG. 1 may be the first region 11A1.

[0027] Other configurations of the light-emitting element 1 will be described below.

[0028] [n-Side Electrode 21] The n-side electrode 21 is disposed on the third surface 11C and is electrically connected to the n-side semiconductor layer 11. As shown in FIG. 2A , one n-side electrode 21 is disposed in the center of the light-emitting element 1 in a plan view. This reduces the variation in the distance between each of the light-emitting portions 100A to 100D and the n-side electrode 21, thereby reducing the variation in luminance of each of the light-emitting portions 100A to 100D. The n-side electrode 21 can be, for example, a single metal layer containing Ti, Rh, Au, Pt, Al, Ag, or Ru, or a laminated structure containing at least two of these metal layers.

[0029] [Transparent Electrode 31] As shown in FIG. 3 , the transparent electrode 31 is disposed below the fourth surface 13A of the p-side semiconductor layer 13 of each of the light-emitting sections 100, and is electrically connected to the p-side semiconductor layer 13. In a plan view, the transparent electrode 31 is disposed in a region overlapping with the light-emitting section 100. The transmittance of the transparent electrode 31 for the peak wavelength of light emitted by the active layer 12 is, for example, 70% or more, preferably 90% or more. The transparent electrode 31 is conductive and has the function of diffusing the current supplied through the p-side electrode 22 in the plane direction of the p-side semiconductor layer 13. Examples of materials for the transparent electrode 31 include ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), ZnO, and In. ２ O ３ etc. can be used.

[0030] [P-Side Electrode 22] As shown in FIG. 3, the p-side electrode 22 is disposed below the translucent electrode 31 and is electrically connected to the translucent electrode 31. The p-side electrode 22 is electrically connected to the p-side semiconductor layer 13 via the translucent electrode 31. As shown in FIG. 2A, the p-side electrodes 22 corresponding to the four light-emitting units 100A to 100D are disposed near the four corners of the first surface 11A, which is rectangular in plan view. In plan view, the distances between the n-side electrode 21 and the p-side electrodes 22 disposed on the four light-emitting units 100A to 100D are approximately the same. This reduces the variation in the distance between the n-side electrode 21 and each p-side electrode 22, thereby reducing the variation in brightness among the light-emitting units 100A to 100D. The p-side electrode 22 can be a single metal layer made of the same material as the n-side electrode 21, or a layered structure including at least two of these metal layers.

[0031] 3, the light-emitting element 1 may further include a light-reflective member 32 disposed on the second region 11A2, thereby reducing light extraction from the second region 11A2.

[0032] The light reflecting member 32 may be, for example, a dielectric multilayer film. Alternatively, the light reflecting member 32 may be, for example, a metal film containing aluminum or silver. By using a dielectric multilayer film as the light reflecting member 32, it is possible to reduce light absorption in the light reflecting member 32 compared to when a metal film is used. Alternatively, the light reflecting member 32 may be, for example, a film made of SiO ２ Alternatively, an insulating film made of an insulating material such as SiN or SiON may be used. The interface between this insulating film and the second region 11A2 can reflect light emitted from the active layer 12. The light-reflecting member 32 may also be disposed on the third region 11A3. The thickness of the light-reflecting member 32 is smaller than the thickness of the protective film 51 described below. The thickness of the light-reflecting member 32 can be, for example, 10 nm or more and 2000 nm or less, preferably 50 nm or more and 1500 nm or less.

[0033] The light emitting element 1 may further include an insulating member 33 , a metal member 34 , an insulating film 41 , an n-side conductive member 61 , a p-side conductive member 62 , and a protective film 51 .

[0034] [Insulating member 33] The insulating member 33 covers at least the fourth surface 13A side of the p-side semiconductor layer 13. The insulating member 33 also covers the third surface 11C. For example, a dielectric multilayer film can be used as the insulating member 33. Light traveling from the active layer 12 toward the p-side semiconductor layer 13 can be reflected toward the first region 11A1 by the insulating member 33. This can improve the light extraction efficiency from the first region 11A1.

[0035] The insulating member 33 can further cover the side surfaces of the light-emitting unit 100. This increases the amount of light reflected toward the first region 11A1, thereby further improving the light extraction efficiency from the first region 11A1.

[0036] As shown in FIG. 3, the insulating member 33 has a first opening 33 a located below the n-side electrode 21 and a second opening 33 b located below the p-side electrode 22 .

[0037] 3, the metal member 34 is disposed below the insulating member 33. The metal member 34 is disposed in contact with the insulating member 33 and the insulating film 41, and is located between the insulating member 33 and the insulating film 41. Light transmitted through the insulating member 33 is reflected by the metal member 34 toward the first region 11A1, thereby improving the light extraction efficiency. The metal member 34 can be, for example, a single metal layer containing Al or Ti, or a laminated structure containing these metal layers.

[0038] [Insulating Film 41] The insulating film 41 covers the insulating member 33 and the metal member 34. The insulating film 41 also covers the side surface 10C of the semiconductor structure 10. The insulating film 41 may be, for example, a film made of SiO ２ 2A , the insulating film 41 may be made of an insulating material such as SiO 2 , SiN, or SiON. The insulating film 41 has a third opening 41 a and a fourth opening 41 b. As shown in FIG. 2A , the third opening 41 a is located inside the first opening 33 a of the insulating member 33, and the fourth opening 41 b is located inside the second opening 33 b of the insulating member 33.

[0039] [n-Side Conductive Member 61] As shown in FIG. 3 , the n-side conductive member 61 is disposed below the insulating film 41. A portion of the n-side conductive member 61 is disposed in contact with the insulating film 41. The n-side conductive member 61 is electrically connected to the n-side electrode 21 through the third opening 41 a and the first opening 33 a. The n-side conductive member 61 may be, for example, a single metal layer containing Ti, Rh, Au, Pt, Ru, or Al, or a laminated structure containing at least two of these metal layers. As shown in FIG. 2A , the n-side conductive member 61 is disposed in the center of the light-emitting element 1 in a planar view. The n-side conductive member 61 has a substantially rectangular shape in a planar view.

[0040] [P-Side Conductive Member 62] As shown in FIG. 3, the p-side conductive member 62 is disposed below the insulating film 41. A portion of the p-side conductive member 62 is disposed in contact with the insulating film 41. The p-side conductive member 62 is electrically connected to the p-side electrode 22 at the fourth opening 41b and the second opening 33b. The p-side conductive member 62 can be a single metal layer made of the same material as the n-side conductive member 61, or a laminated structure including at least two of these metal layers. As shown in FIG. 2A, four p-side conductive members 62 corresponding to the four light emitting units 100A to 100D are disposed overlapping the p-side electrode 22 in a plan view. The p-side conductive member 62 has a substantially rectangular shape in a plan view.

[0041] 3, the protective film 51 covers the first surface 11A. The protective film 51 directly covers the first region 11A1. The protective film 51 covers the second region 11A2 and the third region 11A3 via the light-reflective member 32. The transmittance of the protective film 51 for the peak wavelength of light emitted by the active layer 12 is, for example, 70% or more, and preferably 90% or more. The protective film 51 may be made of, for example, SiO ２ , SiN, or SiON. The thickness of the protective film 51 can be set to, for example, 200 nm or more and 3000 nm or less.

[0042] FIG. 2B shows another example of the shape of the n-side conductive member 61 and the p-side conductive member 62 in a plan view.

[0043] The n-side conductive member 61 is disposed in the center of the light emitting element in a plan view. The n-side conductive member 61 has a square shape in a plan view. In a plan view, the corners of the n-side conductive member 61 are disposed so as to overlap the third surface 11C.

[0044] Four p-side conductive members 62 corresponding to the four light emitting portions 100A to 100D are arranged overlapping the p-side electrodes 22 located near the four corners of the light emitting element in a plan view. Each p-side conductive member 62 extends along the first direction X and the second direction Y.

[0045] FIG. 4A is a schematic bottom view of a light-emitting element according to a first modified example of the embodiment.

[0046] The light-emitting element shown in FIG. 4A has two light-emitting portions 100 arranged in the second direction Y in a plan view, one n-side electrode 21, and two p-side electrodes 22. In a plan view, a third surface 11C is located between the two light-emitting portions 100. The n-side electrode 21 is disposed on the third surface 11C. Two p-side electrodes 22 are disposed near both ends of the light-emitting element in the second direction Y. In the second direction Y, the n-side electrode 21 is located between the two p-side electrodes 22. In the light-emitting element shown in FIG. 4A , as in the above-described embodiment, when the light emission of the multiple light-emitting portions 100 is individually controlled, extraction of light emitted by the light-emitting portions 100 from areas other than the first region 11A1 on the light-emitting portion 100, which is the target of light emission, can be reduced. Furthermore, by using one n-side electrode 21 electrically connected to each of the multiple light-emitting portions 100, the area of ​​the third surface 11C in a plan view can be reduced, as described above, and the area of ​​the light-emitting portion 100 in a plan view can be increased.

[0047] In a plan view, the n-side conductive member 61 overlaps the n-side electrode 21, and the two p-side conductive members 62 each overlap the p-side electrode 22. In the second direction Y, the n-side conductive member 61 is located between the two p-side conductive members 62.

[0048] FIG. 4B is a schematic bottom view of the light-emitting device according to the second modified example of the embodiment.

[0049] 4B has six light-emitting portions 100 aligned in the first direction X and the second direction Y in a plan view. Two light-emitting portions 100 are aligned in the first direction X, and three light-emitting portions 100 are aligned in the second direction Y. The light-emitting element shown in FIG. 4B also has one n-side electrode 21 and six p-side electrodes 22 corresponding to the six light-emitting portions 100.

[0050] In a plan view, a third surface 11C is located between each of the light-emitting units 100. An n-side electrode 21 is disposed on the third surface 11C in the center of the light-emitting element in a plan view. As with the above-described embodiment, in the light-emitting element shown in FIG. 4B , when the light emission of the plurality of light-emitting units 100 is individually controlled, it is possible to reduce the extraction of light emitted by the light-emitting units 100 from areas other than the first region 11A1 on the light-emitting unit 100 that is the light-emitting target. Furthermore, by using one n-side electrode 21 electrically connected to each of the plurality of light-emitting units 100, the area of ​​the third surface 11C in a plan view can be reduced, and the area of ​​the light-emitting unit 100 in a plan view can be increased, as described above.

[0051] Of the six p-side electrodes 22, four p-side electrodes 22 are disposed near the corners of the light-emitting element in a plan view. In the first direction X, the n-side electrode 21 is disposed between the other two p-side electrodes 22.

[0052] In plan view, the n-side conductive member 61 overlaps the n-side electrode 21 , and the six p-side conductive members 62 each overlap the p-side electrode 22 .

[0053] FIG. 4C is a schematic bottom view of the light-emitting device according to the third modified example of the embodiment.

[0054] 4B , the light-emitting element shown in Fig. 4C has, in a plan view, six light-emitting portions 100 arranged in the first direction X and the second direction Y. In addition, the light-emitting element shown in Fig. 4C has three n-side electrodes 21 and six p-side electrodes 22 corresponding to the six light-emitting portions 100.

[0055] Each of the three n-side electrodes 21 is located between two light-emitting units 100 adjacent to each other in the first direction X. The three n-side electrodes 21 are aligned in the second direction Y. By increasing the number of n-side electrodes 21, the variation in current density distribution in each light-emitting unit 100 can be reduced compared to the light-emitting element shown in FIG. 4B in which only one n-side electrode 21 is arranged. This reduces the variation in luminance distribution of the light-emitting element. The n-side conductive member 61 is arranged extending in the second direction Y so as to overlap with the three n-side electrodes 21 aligned in the second direction Y. In the light-emitting element shown in FIG. 4C , as in the above-described embodiment, when the light emission of the multiple light-emitting units 100 is individually controlled, extraction of light emitted by the light-emitting units 100 from areas other than the first region 11A1 on the light-emitting unit 100 that is the light-emitting target can be reduced.

[0056] The light emitting element of the embodiment may have two or more light emitting portions, and may have three light emitting portions, five light emitting portions, or seven or more light emitting portions.

[0057] A light emitting device having a plurality of light emitting units 100 can be produced by arranging a plurality of n-side conductive members 61 and p-side conductive members 62 of the light emitting elements of the embodiment on a mounting substrate having a plurality of wiring units arranged on the upper surface thereof so that the n-side conductive members 61 and p-side conductive members 62 are electrically connected to the respective wiring units. The light emitting units 100 of the light emitting elements 1 mounted on the light emitting device can each be individually controlled for light emission. The light emitting device has, for example, 10,000 to 30,000 light emitting elements 1. The light emitting device has, for example, 20,000 to 150,000 light emitting units 100.

[0058] Next, a method for manufacturing the light-emitting element 1 shown in FIGS. 1 to 3 will be described with reference to FIGS. 5A to 5S. The method for manufacturing the light-emitting element 1 can include the steps described below. Note that although FIGS. 5A to 5S illustrate steps for forming one light-emitting element 1, multiple light-emitting elements 1 may be formed on the first substrate 201. When multiple light-emitting elements 1 are formed on the first substrate 201, the regions in which the multiple light-emitting elements 1 are formed are aligned in the first direction X and the second direction Y. When multiple light-emitting elements 1 are formed on the first substrate 201, the multiple light-emitting elements 1 are separated into multiple light-emitting elements 1 by removing the n-side semiconductor layer 11 in the step of separating the semiconductor structure 10, which will be described later.

[0059] 5A and 5B, the method for manufacturing the light-emitting element 1 includes the steps of preparing a semiconductor structure 10 having a first surface 11A, a second surface 11B, and a third surface 11C. The semiconductor structure 10 has a plurality of light-emitting portions 100 separated by the third surface 11C.

[0060] In the step of preparing the semiconductor structure 10, the semiconductor structure 10 is formed on a first substrate 201. For example, the semiconductor structure 10 can be formed by sequentially forming an n-side semiconductor layer 11, an active layer 12, and a p-side semiconductor layer 13 on the first substrate 201 by MOCVD (Metal Organic Chemical Vapor Deposition). The first substrate 201 can be, for example, sapphire or spinel (MgAl) having one of the C-plane, R-plane, and A-plane as its principal surface. ２ O ４ Alternatively, the first substrate 201 may be a conductive substrate such as SiC (including 6H, 4H, and 3C), ZnS, ZnO, GaAs, or Si.

[0061] In the process of preparing the semiconductor structure 10, a portion of the p-side semiconductor layer 13, a portion of the active layer 12, and a portion of the n-side semiconductor layer 11 are removed to expose a portion of the n-side semiconductor layer 11, thereby forming a third surface 11C. The third surface 11C extends in the first direction X and the second direction Y so as to reach the outer edge of the region where the light-emitting element 1 is formed in plan view. When a plurality of light-emitting elements 1 are formed on the first substrate 201, the third surface 11C is continuous between the regions where adjacent light-emitting elements 1 are formed. The p-side semiconductor layer 13, the active layer 12, and the n-side semiconductor layer 11 can be removed by, for example, RIE (Reactive Ion Etching).

[0062] 5C and 5D , the method for manufacturing the light-emitting element 1 includes a step of forming a translucent electrode 31 on the fourth surface 13A of the p-side semiconductor layer 13, which is located on the opposite side to the active layer 12. The translucent electrode 31 can be formed by a method such as a sputtering method or a vapor deposition method.

[0063] 5E , the manufacturing method of the light-emitting element 1 may include a step of forming the n-side electrode 21 on the third surface 11C and the p-side electrode 22 on the translucent electrode 31. The n-side electrode 21 and the p-side electrode 22 may be formed by, for example, a sputtering method, a vapor deposition method, a CVD (Chemical Vapor Deposition) method, or the like.

[0064] 5F , the manufacturing method of the light-emitting element 1 may include a step of forming an insulating member 33. The insulating member 33 covers the third surface 11C, the fourth surface 13A, the side surfaces of the light-emitting unit 100, the translucent electrode 31, the n-side electrode 21, and the p-side electrode 22. The insulating member 33 may be formed by a method such as sputtering, vapor deposition, CVD, or atomic layer deposition (ALD).

[0065] 5G, the manufacturing method of the light-emitting element 1 may include a step of forming a groove 300 in the semiconductor structure 10. For example, the semiconductor structure 10 is etched from the p-side semiconductor layer 13 side by RIE to form the groove 300. The groove 300 does not reach the first surface 11A. The n-side semiconductor layer 11 is left between the groove 300 and the first substrate 201.

[0066] 5H, the manufacturing method of the light-emitting element 1 may include a step of forming a metal member 34 on the insulating member 33. The metal member 34 may be formed by a method such as a sputtering method, a vapor deposition method, or a CVD method.

[0067] 5I, the manufacturing method of the light-emitting element 1 may include a step of forming a first opening 33a and a second opening 33b in the insulating member 33. The n-side electrode 21 is exposed from the insulating member 33 in the first opening 33a, and the p-side electrode 22 is exposed from the insulating member 33 in the second opening 33b. The first opening 33a and the second opening 33b may be formed by, for example, an RIE method.

[0068] As shown in FIG. 5J, the manufacturing method of the light-emitting element 1 may include a step of covering the structure on the first substrate 201 shown in FIG. 5I with an insulating film 41. The insulating film 41 is formed in the groove 300. The insulating film 41 can be formed by, for example, a sputtering method, a vapor deposition method, a CVD method, or an ALD method. A third opening 41a and a fourth opening 41b are formed in the insulating film 41 by, for example, an RIE method. The third opening 41a is formed in a region overlapping with the first opening 33a of the insulating member 33. The fourth opening 41b is formed in a region overlapping with the second opening 33b of the insulating member 33.

[0069] 5K, the manufacturing method of the light-emitting element 1 may include a step of forming an n-side conductive member 61 and a p-side conductive member 62 on the insulating film 41. The n-side conductive member 61 is electrically connected to the n-side electrode 21 at the third opening 41a and the first opening 33a, and the p-side conductive member 62 is electrically connected to the p-side electrode 22 at the fourth opening 41b and the second opening 33b. The n-side conductive member 61 and the p-side conductive member 62 may be formed by, for example, a sputtering method or a vapor deposition method.

[0070] As shown in FIG. 5L , the manufacturing method of the light-emitting element 1 may include a step of bonding the semiconductor structure 10 and the second substrate 202 via a resin member 210. For example, the resin member 210 is formed so as to cover the insulating film 41, the n-side conductive member 61, and the p-side conductive member 62. The second substrate 202 is then placed on the resin member 210, and the second substrate 202 is pressed against the first substrate 201, thereby bonding the semiconductor structure 10 and the second substrate 202 via the resin member 210. The second substrate 202 may be made of the same material as the first substrate 201. The resin member 210 covers the n-side conductive member 61, the p-side conductive member 62, and the insulating film 41, and fills the groove 300. The resin member 210 may be made of, for example, an epoxy resin, an acrylic resin, or a polyimide resin.

[0071] The method for manufacturing the light-emitting element 1 may include a step of removing the first substrate 201 to expose the first surface 11A of the n-side semiconductor layer 11, after the step of bonding the semiconductor structure 10 and the second substrate 202. The first substrate 201 may be removed by, for example, a laser lift-off (LLO) method, grinding, polishing, etching, or the like.

[0072] The manufacturing method of the light-emitting element 1 can include a step of removing a portion of the n-side semiconductor layer 11 from the first surface 11A side and separating the semiconductor structure 10 into a plurality of parts. At this time, the n-side semiconductor layer 11 is removed so as to reach the surface of the n-side semiconductor layer 11 that defined the bottom of the groove 300. As a result, as shown in FIG. 5N , the semiconductor structure 10 is separated into a plurality of parts separated by the groove 300. In addition, the upper surface 210A of the resin member 210 is exposed at the position of the groove 300. The n-side semiconductor layer 11 can be removed by etching, for example, by a chemical mechanical polishing (CMP) method or an RIE method.

[0073] 5O and 5P, the manufacturing method of the light-emitting element 1 may include a step of forming a light-reflective member 32 on the first surface 11A and on the upper surface 210A of the resin member 210. For example, after the light-reflective member 32 is formed over the entire surface of the first surface 11A by a sputtering method or a CVD method, openings 32a are formed by an RIE method using a resist mask in areas that will be roughened in a step described below.

[0074] 5Q, the manufacturing method of the light-emitting element 1 may include a step of roughening the first region 11A1 of the first surface 11A that is exposed from the light-reflective member 32. For example, the first region 11A1 is roughened by wet etching using an alkaline solution such as TMAH (tetramethylammonium hydroxide) or by RIE using a gas containing chlorine.

[0075] 5R, the manufacturing method of the light-emitting element 1 can include a step of covering the first surface 11A with a protective film 51. The protective film 51 is formed on the first surface 11A so as to cover the light-reflecting member 32. The protective film 51 can be formed by a sputtering method or a CVD method. Thereafter, the light-reflecting member 32 and the protective film 51 located on the upper surface 210A of the resin member 210 are removed to expose the upper surface 210A of the resin member 210.

[0076] The manufacturing method of the light-emitting element 1 can include a step of removing the resin member 210 from the upper surface 210A side of the resin member 210. The resin member 210 can be removed by, for example, etching. As a result, as shown in FIG. 5S, the resin member 210 remains between the second substrate 202 and the semiconductor structure 10, and the light-emitting element 1 is supported on the second substrate 202 via the resin member 210. When a plurality of light-emitting elements 1 are arranged on the second substrate 202, the light-emitting elements 1 are obtained in which adjacent light-emitting elements are separated by a space.

[0077] For example, by irradiating the resin member 210 with laser light from the second substrate 202 side, the resin member 210 between the second substrate 202 and the semiconductor structure 10 is removed, and the light-emitting element 1 can be separated from the second substrate 202.

[0078] Embodiments of the present invention can include the following light emitting devices.

[0079] [Item 1] A semiconductor structure including an n-side semiconductor layer having a first surface, a plurality of second surfaces opposite the first surface, and a third surface opposite the first surface, and a plurality of light emitting units each having an active layer and a p-side semiconductor layer disposed on each of the plurality of second surfaces, wherein the third surface is located between the plurality of light emitting units in a plan view and is exposed from the active layer and the p-side semiconductor layer, an n-side electrode disposed on the third surface and electrically connected to the n-side semiconductor layer, and a p-side electrode disposed on each of the p-side semiconductor layers of the plurality of light emitting units and electrically connected to the p-side semiconductor layer, wherein, in a plan view, the first surface has a first region and a second region having a smaller arithmetic mean roughness than the first region, and the first region overlaps the second surface, and the second region overlaps the third surface. [Item 2] The light emitting device according to item 1, wherein, in a plan view, the second region does not overlap the second surface. [Item 3] The light-emitting element according to item 1, wherein a part of the second region overlaps with the second surface in a plan view. [Item 4] The light-emitting element according to any one of items 1 to 3, further comprising a light-reflecting member disposed on the two regions. [Item 5] The semiconductor structure has four of the light emitting portions, the four light emitting portions including a first light emitting portion, a second light emitting portion adjacent to the first light emitting portion in a first direction, a third light emitting portion adjacent to the first light emitting portion in a second direction orthogonal to the first direction, and a fourth light emitting portion adjacent to the third light emitting portion in the first direction and adjacent to the second light emitting portion in the second direction, the first region overlaps the first light emitting portion, the second light emitting portion, the third light emitting portion, and the fourth light emitting portion in a planar view, and the second region is located between the first light emitting portion and the second light emitting portion, between the first light emitting portion and the third light emitting portion, between the third light emitting portion and the fourth light emitting portion, and between the second light emitting portion and the fourth light emitting portion in a planar view. [Item 6] The light emitting element according to any one of Items 1 to 5, wherein, in a planar view, a width of the third surface is 2 μm or more and 10 μm or less.

[0080] The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. All forms that can be implemented by a person skilled in the art through appropriate design modifications based on the above-described embodiments of the present invention also fall within the scope of the present invention as long as they include the gist of the present invention. In addition, a person skilled in the art may come up with various modifications and alterations within the scope of the concept of the present invention, and these modifications and alterations also fall within the scope of the present invention.

[0081] REFERENCE SIGNS LIST 1...light-emitting element, 10...semiconductor structure, 10C...side surface, 11...n-side semiconductor layer, 11A...first surface, 11A1...first region, 11A2...second region, 11A3...third region, 11B...second surface, 11C...third surface, 12...active layer, 13...p-side semiconductor layer, 13A...fourth surface, 21...n-side electrode, 22...p-side electrode, 31...transparent electrode, 32...light-reflective member, 33...insulating member, 34...metal member, 41...insulating film, 51...protective film, 61...n-side conductive member, 62...p-side conductive member, 100...light-emitting portion, 100A...first light-emitting portion, 100B...second light-emitting portion, 100C...third light-emitting portion, 100D...fourth light-emitting portion, 201...first substrate, 202...second substrate, 210...resin member

Claims

1. A semiconductor structure having an n-side semiconductor layer having a first surface, a plurality of second surfaces opposite to the first surface, and a third surface opposite to the first surface, and a plurality of light emitting units having an active layer and a p-side semiconductor layer arranged on each of the plurality of second surfaces, wherein the third surface is located between the plurality of light emitting units in a plan view and is exposed from the active layer and the p-side semiconductor layer; an n-side electrode arranged on the third surface and electrically connected to the n-side semiconductor layer; and a p-side electrode arranged on each of the p-side semiconductor layers of the plurality of light emitting units and electrically connected to the p-side semiconductor layer, wherein in a plan view, the first surface has a first region and a second region having an arithmetic mean roughness smaller than that of the first region, the first region overlapping the second surface, and the second region overlapping the third surface.

2. The light-emitting element according to claim 1, wherein the second region does not overlap the second surface in a plan view.

3. The light-emitting element according to claim 1, wherein a portion of the second region overlaps with the second surface in a plan view.

4. The light-emitting element according to any one of claims 1 to 3, further comprising a light-reflecting member disposed on said two regions.

5. The light-emitting element according to any one of claims 1 to 3, wherein the semiconductor structure has four of the light-emitting sections, the four light-emitting sections being a first light-emitting section, a second light-emitting section adjacent to the first light-emitting section in a first direction, a third light-emitting section adjacent to the first light-emitting section in a second direction perpendicular to the first direction, and a fourth light-emitting section adjacent to the third light-emitting section in the first direction and adjacent to the second light-emitting section in the second direction, wherein in a planar view, the first region overlaps the first light-emitting section, the second light-emitting section, the third light-emitting section, and the fourth light-emitting section, and wherein in a planar view, the second region is located between the first light-emitting section and the second light-emitting section, between the first light-emitting section and the third light-emitting section, between the third light-emitting section and the fourth light-emitting section, and between the second light-emitting section and the fourth light-emitting section.

6. The light-emitting element according to any one of claims 1 to 3, wherein the width of the third surface in a plan view is not less than 2 µm and not more than 10 µm.

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