Light-emitting device

Abstract

To provide a light-emitting device capable of reducing nonuniformity of current density distribution.SOLUTION: A light-emitting device comprises: a semiconductor structure; a translucent conductive film which is disposed on a second semiconductor layer; a translucent insulation film which is disposed on the translucent conductive film and includes a plurality of first openings; and a light reflectance conductive film which is disposed on the translucent insulation film and in contact with the translucent conductive film in the first openings. In a planar view, each of a plurality of extending parts of a first semiconductor layer includes an end which is positioned closest to a second outer peripheral part. In the planar view, the translucent conductive film includes a plurality of outer edges opposed to the ends of the plurality of extending parts in a second direction. In the planar view, the plurality of first openings pass an outer edge closest to the second outer peripheral part in the plurality of outer edges of the translucent conductive film, is not positioned between a first straight line extending in a first direction and a first outer peripheral part and is positioned between the first straight line and the second outer peripheral part.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] For example, Patent Document 1 discloses a configuration in which a plurality of n-dot electrodes are arranged along the long side of a light-emitting element having a rectangular shape in a plan view. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-143682 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a light emitting element capable of reducing unevenness in current density distribution. [Means for solving the problem]

[0005] According to one aspect of the present invention, a light-emitting element is a semiconductor structure including a first semiconductor layer having a first region and a second region located inside the first region in a plan view, an active layer disposed on the second region, and a second semiconductor layer disposed on the active layer, wherein the first region has a first outer periphery and a second outer periphery extending in a first direction, a third outer periphery and a fourth outer periphery extending in a second direction perpendicular to the first direction, and a plurality of extensions extending from the first outer periphery in the second direction and spaced apart from each other in the first direction. The semiconductor structure includes a semiconductor structure in which the length in the first direction of the first outer periphery and the second outer periphery is longer than the length in the second direction of the third outer periphery and the fourth outer periphery, a translucent conductive film disposed on the second semiconductor layer, a translucent insulating film disposed on the translucent conductive film and having a plurality of first openings located above the translucent conductive film, a light-reflective conductive film disposed on the translucent insulating film and in contact with the translucent conductive film at the first openings, a first electrode layer in contact with the extensions, and a second electrode layer in contact with the light-reflective conductive film. In a plan view, each of the plurality of extensions has an end located closest to the second outer periphery. In a plan view, the translucent conductive film has a plurality of outer edges that face each of the ends of the plurality of extensions in the second direction and are spaced apart from each other in the first direction. In a planar view, the multiple first openings pass through the outer edge of the multiple outer edges of the translucent conductive film that is closest to the second outer periphery, and are not located between a first straight line extending in the first direction and the first outer periphery, but are located between the first straight line and the second outer periphery. Effect of the Invention

[0006] According to the present invention, it is possible to provide a light emitting element capable of reducing unevenness in the current density distribution. [Brief description of the drawings]

[0007] [Figure 1] FIG. 2 is a schematic plan view of a light emitting element according to the embodiment. [Figure 2A] 2 is an enlarged plan view of a region in FIG. 1 where a second external electrode layer is arranged. [Figure 2B]2 is an enlarged plan view of a region in FIG. 1 where a first external electrode layer is arranged. [Diagram 3] FIG. 2 is a schematic cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is an enlarged cross-sectional view of a portion of FIG. [Figure 5A] 13 is a measurement image of the emission intensity distribution of the light-emitting element of the first comparative example. [Figure 5B] 13 is a measurement image of the emission intensity distribution of the light-emitting element of the second comparative example. [Figure 6A] 4 is a measurement image of the emission intensity distribution of the light-emitting element of the first embodiment. [Figure 6B] 13 is a measurement image of the emission intensity distribution of the light-emitting element of the second embodiment. [Figure 7] FIG. 2 is a schematic plan view of a light-emitting element according to Comparative Example 1. [Figure 8] FIG. 11 is a schematic plan view of a light-emitting element according to Comparative Example 2. [Figure 9] 1 is a schematic plan view of a light-emitting element according to a first embodiment. [Figure 10] FIG. 13 is a schematic plan view of a light-emitting device according to a modified example of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, the embodiments will be described with reference to the drawings. In each drawing, the same components are given the same reference numerals. Since each drawing is a schematic illustration of the embodiment, the scale, interval, or positional relationship of each component may be exaggerated, or some components may not be shown. In addition, as a cross-sectional view, an end view showing only a cut surface may be shown. In addition, in the cross-sectional view, the cross section of the semiconductor structure is not hatched in order to make the boundaries of each layer of the semiconductor structure easier to see.

[0009] In the following description, components having substantially the same functions are indicated by common reference symbols, and descriptions may be omitted. In addition, terms indicating a specific direction or position (for example, "upper", "lower", and other terms including these terms) may be used. However, these terms are merely used for the purpose of making the relative direction or position in the referenced drawings easier to understand. As long as the relationship of the relative direction or position by terms such as "upper" and "lower" in the referenced drawings is the same, the arrangement in drawings other than the present disclosure, in actual products, etc., may not be the same as that in the referenced drawings. In this specification, the positional relationship expressed as "upper" includes cases where the members are in contact with the object to be covered and cases where the members are not in contact but are located above. In addition, in this specification, unless otherwise specified, the member covering the object to be covered includes cases where the member is in contact with the object to be covered and directly covers the object to be covered, and cases where the member is not in contact with the object to be covered and indirectly covers the object to be covered.

[0010] In the figures shown below, a first direction X, a second direction Y, and a third direction Z are shown, which are perpendicular to each other. In the description of this specification, the arrow direction of the third direction Z is the upward direction, and the direction opposite to the arrow direction of the third direction Z is the downward direction. In addition, a "straight line extending in the first direction X" is a straight line that is substantially parallel to the first direction X in a plan view, and also includes a straight line that is deviated from the first direction X by 3° or less. Similarly, a "straight line extending in the second direction Y" is a straight line that is substantially parallel to the second direction Y in a plan view, and also includes a straight line that is deviated from the second direction Y by 3° or less.

[0011] A light-emitting element 1A of the embodiment will be described with reference to Fig. 1 to Fig. 4. The light-emitting element 1A of the embodiment includes a semiconductor structure 100, a light-transmitting conductive film 40, a light-transmitting insulating film 50, a light-reflective conductive film 60, a first electrode layer 70, and a second electrode layer 80. Each component will be described below.

[0012] [Semiconductor structure] As shown in Fig. 3 and Fig. 4, the semiconductor structure 100 includes a first semiconductor layer 10, an active layer 20, and a second semiconductor layer 30. The semiconductor structure 100 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 It includes all semiconductors with compositions in which the composition ratios x and y are changed within the respective ranges in the chemical formula N (0≦x≦1, 0≦y≦1, x+y≦1). In addition, in the above chemical formula, those that further contain Group V elements other than N (nitrogen) and those that further contain various elements added to control various physical properties such as the conductivity type are also included in the "nitride semiconductor".

[0013] The first semiconductor layer 10 includes a semiconductor layer containing n-type impurities. The first semiconductor layer 10 includes a first region 11 and a second region 12 located inside the first region 11 in a plan view, as shown in FIG.

[0014] The first region 11 is exposed from the active layer 20 and the second semiconductor layer 30. The first region 11 has a first outer peripheral portion 11A, a second outer peripheral portion 11B, a third outer peripheral portion 11C, and a fourth outer peripheral portion 11D. The first outer peripheral portion 11A and the second outer peripheral portion 11B extend in a first direction X. The third outer peripheral portion 11C and the fourth outer peripheral portion 11D extend in a second direction Y. The length of each of the first outer peripheral portion 11A and the second outer peripheral portion 11B in the first direction X is longer than the length of each of the third outer peripheral portion 11C and the fourth outer peripheral portion 11D in the second direction Y. In a plan view, the first outer peripheral portion 11A, the second outer peripheral portion 11B, the third outer peripheral portion 11C, and the fourth outer peripheral portion 11D continuously surround the second region 12.

[0015] The first region 11 further has a plurality of extension portions 11E. The plurality of extension portions 11E extend in the second direction Y from the first outer peripheral portion 11A toward the second outer peripheral portion 11B. The plurality of extension portions 11E are located apart from each other in the first direction X. For example, FIG. 1 shows three extension portions 11E located apart from each other in the first direction X. The number of extension portions 11E may be two, or may be four or more. The extension portions 11E extend only from the first outer peripheral portion 11A, and do not extend from the second outer peripheral portion 11B, the third outer peripheral portion 11C, and the fourth outer peripheral portion 11D.

[0016] In plan view, each of the multiple extension portions 11E has an end portion 11Ea located closest to the second outer periphery 11B. In plan view, the end portion 11Ea of the extension portion 11E is located closer to the first outer periphery 11A than the bisector that divides the light-emitting element 1A in the second direction Y.

[0017] 3 and 4, the active layer 20 is disposed on the second region 12 of the first semiconductor layer 10. The active layer 20 is a light-emitting layer that emits light, and can have, for example, an MQW (Multiple Quantum Well) structure including a plurality of barrier layers and a plurality of well layers.

[0018] The second semiconductor layer 30 is disposed on the active layer 20. The second semiconductor layer 30 has a semiconductor layer containing p-type impurities.

[0019] The first semiconductor layer 10 has a first surface 10a and a second surface 10b located on the opposite side to the first surface 10a in the third direction Z. The second surface 10b has the above-mentioned first region 11 and second region 12. Light emitted by the active layer 20 is extracted to the outside of the semiconductor structure 100 mainly from the first surface 10a.

[0020] The light-emitting element 1A may include a substrate 200 that supports the semiconductor structure 100. The semiconductor structure 100 is disposed on the substrate 200 such that the first semiconductor layer 10 is located on the substrate 200 side in the third direction Z. A first surface 10a of the first semiconductor layer 10 is in contact with the substrate 200. The material of the substrate 200 may be, for example, sapphire, spinel, GaN, SiC, ZnS, ZnO, GaAs, or Si. The light-emitting element 1A may not include the substrate 200.

[0021] [Transparent conductive film] 3 and 4, the translucent conductive film 40 is disposed on the second semiconductor layer 30. The translucent conductive film 40 is in contact with the second semiconductor layer 30 and is electrically connected to the second semiconductor layer 30. The translucent conductive film 40 is located above the second region 12 of the first semiconductor layer 10, and is not located above the first region 11 in which the active layer 20 and the second semiconductor layer 30 are not disposed.

[0022] The translucent conductive film 40 is translucent to the light emitted by the active layer 20. The translucent conductive film 40 has a transmittance of, for example, 60% or more for the peak wavelength of the light emitted by the active layer 20. This can reduce the absorption of light in the translucent conductive film 40. Furthermore, the translucent conductive film 40 can diffuse the current supplied from the second electrode layer 80 in the surface direction of the second semiconductor layer 30. This can reduce unevenness in the current density distribution. The translucent conductive film 40 can be made of, for example, ITO (Indium Tin Oxide), ZnO (Zinc Oxide), In2O3 (Indium Oxide), or the like.

[0023] 1 to 2B, in a plan view, the translucent conductive film 40 has multiple outer edges 40a that face the ends 11Ea of the multiple extension portions 11E of the first semiconductor layer 10 in the second direction Y. The multiple outer edges 40a are located apart from each other in the first direction X. In a plan view, the outer edges 40a of the translucent conductive film 40 are located apart from the ends 11Ea of the extension portions 11E in the second direction Y.

[0024] [Transparent insulation film] 3 and 4, the translucent insulating film 50 is disposed on the translucent conductive film 40. The translucent insulating film 50 has a plurality of first openings 50a located above the translucent conductive film 40. In the first openings 50a, the translucent conductive film 40 is exposed from the translucent insulating film 50 without being covered by the translucent insulating film 50.

[0025] A part of the light emitted from the active layer 20 toward the second semiconductor layer 30 can be directed toward the first surface 10a of the first semiconductor layer 10, which is the main light extraction surface, by total reflection at the interface between the translucent insulating film 50 and the translucent conductive film 40. As the translucent insulating film 50, for example, a single layer film of a silicon oxide film can be used. Alternatively, as the translucent insulating film 50, a dielectric multilayer film can be used.

[0026] [Light-reflective conductive film] 3 and 4, the light-reflective conductive film 60 is disposed on the light-transmitting insulating film 50. The light-reflective conductive film 60 contacts the light-transmitting conductive film 40 at a first opening 50a of the light-transmitting insulating film 50. The light-reflective conductive film 60 is electrically connected to the light-transmitting conductive film 40 at the first opening 50a.

[0027] Of the light emitted from the active layer 20 toward the second semiconductor layer 30, light that does not satisfy the total reflection condition at the interface between the light-transmitting insulating film 50 and the light-transmitting conductive film 40 can be transmitted through the light-transmitting insulating film 50 and reflected toward the first surface 10a by the light-reflective conductive film 60. The reflectance of the light-reflective conductive film 60 with respect to the peak wavelength of the light emitted by the active layer 20 is, for example, 60% or more. The light-reflective conductive film 60 preferably contains, for example, silver or aluminum. The light-reflective conductive film 60 may also contain nickel, titanium, platinum, or the like. The light-reflective conductive film 60 may have a single-layer structure or a laminated structure in which a plurality of metal films are laminated.

[0028] [First electrode layer] 3, the first electrode layer 70 contacts the extending portion 11E of the first semiconductor layer 10. The first electrode layer 70 is electrically connected to the first semiconductor layer 10 via the extending portion 11E. Examples of materials that can be used for the first electrode layer 70 include titanium, platinum, gold, aluminum, and copper. The first electrode layer 70 may have a single-layer structure, or may have a laminated structure in which a plurality of metal films are laminated.

[0029] The number of first openings 50a in the light-transmitting insulating film 50 is greater than the number of extending portions 11E of the first semiconductor layer 10. In other words, the number of portions where the light-reflective conductive film 60 and the light-transmitting conductive film 40 contact each other is greater than the number of portions where the first electrode layer 70 and the first semiconductor layer 10 contact each other.

[0030] [Second electrode layer] The second electrode layer 80 is in contact with the light-reflective conductive film 60. The second electrode layer 80 is electrically connected to the second semiconductor layer 30 via the light-reflective conductive film 60 and the light-transmitting conductive film 40. As a material for the second electrode layer 80, for example, the same material as the material for the first electrode layer 70 can be used. The second electrode layer 80 may have a single-layer structure, or may have a layered structure in which a plurality of metal films are layered.

[0031] When a forward voltage is applied between the first electrode layer 70 and the second electrode layer 80 so that the potential of the second electrode layer 80 is higher than the potential of the first electrode layer 70, a current flows from the second electrode layer 80 to the first electrode layer 70 through the light-reflective conductive film 60, the light-transmitting conductive film 40, and the semiconductor structure 100. When a current is supplied to the active layer 20, the active layer 20 emits light.

[0032] 1 to 2B, in plan view, a straight line passing through the outer edge 40a closest to the second outer periphery 11B of the first semiconductor layer 10 among the multiple outer edges 40a of the translucent conductive film 40 and extending in the first direction X is defined as a first straight line L1. When the positions of all the outer edges 40a in the second direction Y are the same, a straight line passing through any one of the outer edges 40a and extending in the first direction X is defined as the first straight line L1. A part of the first straight line L1 overlaps with the outer edge 40a of the translucent conductive film 40 closest to the second outer periphery 11B in plan view.

[0033] In a plan view, the first openings 50a of the light-transmitting insulating film 50 are not located between the first straight line L1 and the first outer periphery 11A, but between the first straight line L1 and the second outer periphery 11B. In a plan view, the first openings 50a are located in a first partial region 12A surrounded by the first straight line L1, the second outer periphery 11B, the third outer periphery 11C, and the fourth outer periphery 11D in the second region 12. The first openings 50a are not located in a second partial region 12B surrounded by the first straight line L1, the first outer periphery 11A, the third outer periphery 11C, and the fourth outer periphery 11D in the second region 12. The end 11Ea of the extension 11E is located in the second partial region 12B. The area of ​​the first partial region 12A is larger than the area of ​​the second partial region 12B.

[0034] The first opening 50a serves as a current inflow portion for the semiconductor structure 100, and the extending portion 11E serves as a current outflow portion for the semiconductor structure 100. Of the multiple first openings 50a, current tends to concentrate in the first openings 50a that are relatively closer to the extending portion 11E in a plan view.

[0035] 7 and 8, the first opening 50a is also located between the first straight line L1 and the first outer periphery 11A. In such a comparative example, current tends to concentrate in the semiconductor structure 100 below the first opening 50a close to the extension 11E in the region between the first straight line L1 and the first outer periphery 11A. The emission intensity becomes relatively high in the portion where the current is concentrated in the region including the active layer 20 and the second semiconductor layer 30 of the semiconductor structure 100, which may cause unevenness in the emission intensity distribution of the light emitting element.

[0036] According to this embodiment, since the first opening 50a is not positioned between the first straight line L1 and the first outer periphery 11A, it is possible to reduce current concentration in the semiconductor structure 100 below the first opening 50a close to the extension 11E compared to the comparative example, and to reduce unevenness in the current density distribution in the semiconductor structure 100. This reduces unevenness in the emission intensity distribution of the light emitting element 1A. In addition, it is possible to make the semiconductor structure 100 below the first opening 50a close to the extension 11E less susceptible to deterioration or destruction due to heat.

[0037] Furthermore, according to this embodiment, in the region between the first straight line L1 and the first outer periphery 11A where the emission intensity is likely to be high, the first opening 50a is not disposed, and the translucent insulating film 50 contacts the translucent conductive film 40. Therefore, light with high emission intensity is totally reflected at the interface between the translucent insulating film 50 and the translucent conductive film 40, and the brightness of the light extracted from the first surface 10a can be increased.

[0038] 2A and 2B, a line passing through the outer edge 40a of the translucent conductive film 40 closest to the second outer periphery 11B and extending in the second direction Y is defined as a second line L2. In addition, in plan view, a line extending in the first direction X near the first line L1 is defined as a third line L3. In plan view, the third line L3 is located between the first line L1 and the second outer periphery 11B. The distance between the third line L3 and the first line L1 in the second direction Y is shorter than the distance between the third line L3 and the second outer periphery 11B in both directions Y.

[0039] Also, the lines extending in the first direction X at a position farther from the first line L1 in the second direction Y than the third line L3 are defined as the fourth line L4 and the fifth line L5. In the second direction Y, the third line L3 is located closer to the first outer periphery 11A than the fourth line L4 and the fifth line L5. In the second direction Y, the fourth line L4 is located closer to the second outer periphery 11B than the third line L3 and the fifth line L5. In the second direction Y, the fifth line L5 is located between the third line L3 and the fourth line L4.

[0040] In a plan view, the multiple first openings 50a are positioned on a third straight line L3, the multiple first openings 50a are positioned on a fourth straight line L4, and the multiple first openings 50a are positioned on a fifth straight line L5.

[0041] The third straight line L3 is closer to the extending portion 11E in the second direction Y than the fourth straight line L4 and the fifth straight line L5. When the first opening 50a closest to the extending portion 11E in a plan view among the multiple first openings 50a is located on such a third straight line L3, a current is likely to concentrate in the semiconductor structure 100 below the first opening 50a.

[0042] Therefore, among the multiple first openings 50a, the first opening 50a1 closest to the extension portion 11E in plan view is preferably located on the second straight line L2 (excluding the intersection of the second straight line L2 and the third straight line L3). This can reduce current concentration in the semiconductor structure 100 below the first opening 50a1 closest to the extension portion 11E, and reduce unevenness in the current density distribution, compared to when the first opening 50a closest to the extension portion 11E in plan view is located on the third straight line L3. In the example shown in Figures 2A and 2B, the first opening 50a1 closest to the extension portion 11E in plan view is located on the fifth straight line L5.

[0043] 3, the light-transmitting insulating film 50 is also disposed on the first region 11 of the first semiconductor layer 10. The light-transmitting insulating film 50 covers the upper surfaces of the first outer peripheral portion 11A, the second outer peripheral portion 11B, the third outer peripheral portion 11C, and the fourth outer peripheral portion 11D.

[0044] The translucent insulating film 50 has a second opening 50b located above the extending portion 11E. The translucent insulating film 50 has a plurality of second openings 50b corresponding to the plurality of extending portions 11E. The first electrode layer 70 contacts the extending portion 11E at the second openings 50b.

[0045] In a configuration in which the first opening 50a1 closest to the extension 11E is located on the second straight line L2 in a plan view, the width of the second opening 50b in the first direction X is preferably larger than the width of the second opening 50b in the second direction Y. As shown in FIG. 1 to FIG. 2B, the shape of the second opening 50b is an ellipse elongated in the first direction X in a plan view. Alternatively, the shape of the second opening 50b may be a rectangle elongated in the first direction X in a plan view. In a plan view, the first opening 50a1 located on the second straight line L2 and closest to the extension 11E faces the long side of the second opening 50b having the above shape. This can reduce current concentration in the semiconductor structure 100 below the first opening 50a1 closest to the extension 11E compared to a case in which the first opening 50a1 closest to the extension 11E faces a corner of the second opening 50b.

[0046] As described above, the second opening 50b that is long in the first direction X is easier to reduce the angle between the side surface of the light-transmitting insulating film 50 that defines the second opening 50b and the lower surface of the light-transmitting insulating film 50, compared to the second opening 50b that is circular or square in plan view. This makes it easier to increase the thickness of the light-reflective conductive film 60 that covers the side surface of the light-transmitting insulating film 50, and improves the reliability of the light-reflective conductive film 60. According to this embodiment, the angle between the side surface of the light-transmitting insulating film 50 that defines the second opening 50b and the lower surface of the light-transmitting insulating film 50 can be, for example, 20° or more and 40° or more.

[0047] Of the multiple first openings 50a arranged on the third line L3, which is closer to the extension portion 11E in the second direction Y than the fourth line L4 and the fifth line L5, it is preferable that there are multiple first openings 50a2 closest to the extension portion 11E in a planar view. The shortest distances between the multiple first openings 50a2 and the extension portion 11E in a planar view are substantially equidistant. This can reduce current concentration in the semiconductor structure 100 below one first opening 50a2. Note that "substantially equidistant" means that the difference in distance is within 3 μm.

[0048] 3, the first electrode layer 70 includes a first internal electrode layer 71 and a first external electrode layer 72, and the second electrode layer 80 includes a second internal electrode layer 81 and a second external electrode layer 82. As shown in Fig. 1, the first external electrode layer 72 and the second external electrode layer 82 are located apart in the first direction X across a bisector that divides the light emitting element 1A in two equal parts in the first direction X in a plan view. The first external electrode layer 72 and the second external electrode layer 82 are electrically connected, for example, via a conductive member such as solder, to a wiring member of a wiring board on which the light emitting element 1A is mounted.

[0049] The first internal electrode layer 71 is disposed above the second region 12 of the first semiconductor layer 10, in other words, in a region in the semiconductor structure 100 where the first semiconductor layer 10, the active layer 20, and the second semiconductor layer 30 are stacked. The first internal electrode layer 71 is also disposed on the extension portion 11E of the first region 11 of the first semiconductor layer 10, and is in contact with the extension portion 11E. The first external electrode layer 72 is disposed on the first internal electrode layer 71, and is in contact with the first internal electrode layer 71. The first external electrode layer 72 is electrically connected to the first semiconductor layer 10 via the first internal electrode layer 71.

[0050] The second internal electrode layer 81 is disposed above the second region 12 of the first semiconductor layer 10, but is not disposed above the first region 11. The second internal electrode layer 81 is in contact with the light-reflective conductive film 60. The second external electrode layer 82 is disposed on the second internal electrode layer 81, and in contact with the second internal electrode layer 81. The second external electrode layer 82 is electrically connected to the second semiconductor layer 30 via the second internal electrode layer 81, the light-reflective conductive film 60, and the light-transmitting conductive film 40.

[0051] As shown in Fig. 1, among the multiple first openings 50a of the light-transmitting insulating film 50, the number of the first openings 50a overlapping the first external electrode layer 72 and the second external electrode layer 82 in a plan view is preferably greater than the number of the first openings 50a not overlapping the first external electrode layer 72 and the second external electrode layer 82. This makes it easier to dissipate heat accompanying light emission from the active layer 20 to a wiring board or the like on which the light-emitting element 1A is mounted, via the light-transmitting conductive film 40, the light-reflecting conductive film 60 in contact with the light-transmitting conductive film 40 at the first openings 50a, the first electrode layer 70, and the second electrode layer 80. The first internal electrode layer 71 is not in contact with the light-reflecting conductive film 60, but is disposed on the light-reflecting conductive film 60 via an insulating film described later, and heat is transferred from the light-reflecting conductive film 60 to the first internal electrode layer 71 via the insulating film.

[0052] In particular, since the temperature is likely to become high in an area close to the extending portion 11E where the emission intensity is likely to be high, it is preferable that all of the first openings 50a located on the third straight line L3 close to the extending portion 11E among the multiple first openings 50a overlap with the first external electrode layer 72 or the second external electrode layer 82 in a plan view. This makes it easier to effectively dissipate heat associated with the emission of light from the active layer 20.

[0053] In order to efficiently transfer heat associated with the light emission of the active layer 20 to the first internal electrode layer 71 or the second internal electrode layer 81 made of a metal material having a higher thermal conductivity than the insulating film, it is preferable that the multiple first openings 50a are not located in the region 300 between the first internal electrode layer 71 and the second internal electrode layer 81 in a planar view.

[0054] At the corners of the light emitting element 1A in plan view, light emitted from the active layer 20 toward the first surface 10a or side surface of the first semiconductor layer 10 is likely to be reflected by the first surface 10a or the side surface and return into the semiconductor structure 100.

[0055] Therefore, as shown in FIG. 2A, in a plan view, the first opening 50a located at the end on the third outer periphery 11C side among the multiple first openings 50a located on the third straight line L3, and the first opening 50a located at the end on the third outer periphery 11C side among the multiple first openings 50a located on the fourth straight line L4 are preferably located farther away from the third outer periphery 11C in the first direction X than the first opening 50a located at the end on the third outer periphery 11C side among the multiple first openings 50a located on the fifth straight line L5. In other words, in a plan view, the first opening 50a is not located near the two corners on the third outer periphery 11C side. This allows the return light reflected at the two corners on the third outer periphery 11C side to be totally reflected at the interface between the translucent insulating film 50 and the translucent conductive film 40, thereby increasing the brightness of the light extracted from the first surface 10a.

[0056] Similarly, as shown in FIG. 2B, in plan view, the first opening 50a located at the end on the fourth outer periphery 11D side among the multiple first openings 50a located on the third straight line L3, and the first opening 50a located at the end on the fourth outer periphery 11D side among the multiple first openings 50a located on the fourth straight line L4 are preferably located farther away from the fourth outer periphery 11D in the first direction X than the first opening 50a located at the end on the fourth outer periphery 11D side among the multiple first openings 50a located on the fifth straight line L5. In other words, in plan view, the first opening 50a is not located near the two corners on the fourth outer periphery 11D side. This allows the return light reflected at the two corners on the fourth outer periphery 11D side to be totally reflected at the interface between the translucent insulating film 50 and the translucent conductive film 40, thereby increasing the brightness of the light extracted from the first surface 10a.

[0057] 3 and 4, the light emitting element 1A may further include an insulating film 90 disposed on the first internal electrode layer 71 and the second internal electrode layer 81. For example, the insulating film 90 may have a first insulating film 91 and a second insulating film 92. As the first insulating film 91 and the second insulating film 92, for example, a silicon oxide film may be used.

[0058] The first insulating film 91 is disposed on the light-transmitting insulating film 50 and the light-reflective conductive film 60. The first insulating film 91 has a fifth opening 91a located above the light-reflective conductive film 60. The second internal electrode layer 81 contacts the light-reflective conductive film 60 at the fifth opening 91a of the first insulating film 91.

[0059] The first insulating film 91 is located above the extending portion 11E and has a sixth opening 91b that is continuous with the second opening 50b of the light-transmitting insulating film 50. The first internal electrode layer 71 contacts the extending portion 11E at the sixth opening 91b of the first insulating film 91 and the second opening 50b of the light-transmitting insulating film 50.

[0060] The first insulating film 91 is disposed in the third direction Z between the light-reflective conductive film 60 and the second internal electrode layer 81 and between the light-reflective conductive film 60 and the first internal electrode layer 71.

[0061] The second insulating film 92 is disposed on the first insulating film 91, on the first internal electrode layer 71, and on the second internal electrode layer 81. The second insulating film 92 is disposed in a region 300 between the first internal electrode layer 71 and the second internal electrode layer 81 in a plan view.

[0062] The second insulating film 92 has a third opening 92a located above the first internal electrode layer 71. The first external electrode layer 72 is disposed on the second insulating film 92, and contacts the first internal electrode layer 71 at the third opening 92a.

[0063] The second insulating film 92 has a fourth opening 92b located above the second internal electrode layer 81. The second external electrode layer 82 is disposed on the second insulating film 92, and contacts the second internal electrode layer 81 at the fourth opening 92b.

[0064] As shown in FIG. 4, the upper surface of the light-reflecting conductive film 60 located above the first opening 50a of the light-transmitting insulating film 50 is more likely to be recessed than the upper surface of the light-reflecting conductive film 60 located on the light-transmitting insulating film 50 where the first opening 50a is not located. The insulating film 90 laminated on the light-reflecting conductive film 60 is also more likely to be recessed at a position above the recess of the light-reflecting conductive film 60. Therefore, when the multiple first openings 50a of the light-transmitting insulating film 50 overlap the outer edge of the third opening 92a and the outer edge of the fourth opening 92b of the second insulating film 92 in a plan view, the side surface of the second insulating film 92 that defines the third opening 92a and the fourth opening 92b is easily distorted so as to be recessed. When the side surface of the second insulating film 92 is distorted, the second insulating film 92 is more likely to crack due to thermal stress.

[0065] Therefore, in a plan view, it is preferable that the multiple first openings 50a of the light-transmitting insulating film 50 do not overlap with the outer edge of the third opening 92a and the outer edge of the fourth opening 92b of the second insulating film 92. This makes it possible to prevent cracks from occurring in the second insulating film 92.

[0066] Next, the results of measuring the emission intensity distribution for the example and the comparative example will be described.

[0067] FIG. 5A is a measured image of the emission intensity distribution of the light-emitting element 2A of the first comparative example shown in FIG.

[0068] FIG. 5B is a measurement image of the emission intensity distribution of the light-emitting element 2B of the second comparative example shown in FIG.

[0069] The light emitting element 2A of the first comparative example shown in Fig. 7 and the light emitting element 2B of the second comparative example shown in Fig. 8 are different from the light emitting element 1A of the embodiment described above in that the first opening 50a is also located between the first straight line L1 and the first outer peripheral portion 11A in plan view. Note that in the light emitting element 2A of the first comparative example and the light emitting element 2B of the second comparative example, the shapes and numbers of the fifth opening 91a of the first insulating film 91 and the fourth opening 92b of the second insulating film 92 in plan view are different from those of the light emitting element 1A of the embodiment, but their designs have almost no effect on reducing unevenness in the emission intensity distribution.

[0070] FIG. 6A is a measurement image of the emission intensity distribution for the light-emitting element 1B of the first embodiment shown in FIG.

[0071] 9, the first opening 50a is not located between the first straight line L1 and the first outer periphery 11A in plan view, similar to the light emitting element 1A of the embodiment. Note that in the light emitting element 1B of the first embodiment, the shapes and the number of the fifth opening 91a of the first insulating film 91 and the fourth opening 92b of the second insulating film 92 in plan view are different from those of the light emitting element 1A of the embodiment.

[0072] FIG. 6B is a measured image of the emission intensity distribution of the light-emitting element 1A of the second embodiment having the configuration shown in FIGS. 1 to 4 and described above.

[0073] 5A to 6A are images showing the emission intensity distribution of the light-emitting element when a current of 70 mA is applied. FIG. 6B is an image showing the emission intensity distribution of the light-emitting element when a current of 20 mA is applied. In each of FIGS. 5A to 6B, the emission intensity distribution is expressed in grayscale. The higher the luminance in the grayscale, the stronger the emission intensity.

[0074] 5A to 6B, the light-emitting element 1B of the first embodiment and the light-emitting element 1A of the second embodiment have reduced unevenness in emission intensity distribution compared to the light-emitting element 2A of the first comparative example and the light-emitting element 2B of the second comparative example. Since the emission intensity distribution is strongly correlated with the current density distribution, it can be said that the light-emitting element 1B of the first embodiment and the light-emitting element 1A of the second embodiment can reduce unevenness in current density distribution compared to the light-emitting element 2A of the first comparative example and the light-emitting element 2B of the second comparative example.

[0075] FIG. 10 is a schematic plan view of a light-emitting element 1C according to a modified example of the embodiment.

[0076] The light emitting element 1C shown in FIG. 10 has a larger number of first openings 50a arranged around the extending portion 11E than the light emitting element 1A shown in FIG. 1, which makes it easier to reduce unevenness in the current density distribution.

[0077] Embodiments of the present invention may include the following light emitting devices.

[0078] [Section 1] A semiconductor structure including a first semiconductor layer having, in a plan view, a first region and a second region located inside the first region, an active layer disposed on the second region, and a second semiconductor layer disposed on the active layer, wherein the first region has a first outer periphery and a second outer periphery extending in a first direction, a third outer periphery and a fourth outer periphery extending in a second direction perpendicular to the first direction, and a plurality of extension portions extending from the first outer periphery in the second direction and positioned apart from each other in the first direction, and a length in the first direction of the first outer periphery and the second outer periphery is longer than a length in the second direction of the third outer periphery and the fourth outer periphery; a transparent conductive film disposed on the second semiconductor layer; a transparent insulating film disposed on the transparent conductive film and having a plurality of first openings positioned above the transparent conductive film; a light-reflecting conductive film disposed on the light-transmitting insulating film and in contact with the light-transmitting conductive film at the first opening; A first electrode layer in contact with the extension portion; a second electrode layer in contact with the light-reflective conductive film; Equipped with In a plan view, each of the plurality of extension portions has an end portion located closest to the second outer circumferential portion, the translucent conductive film has a plurality of outer edges that face the ends of the plurality of extension portions in the second direction and are spaced apart from each other in the first direction in a plan view; A light-emitting element in which, when viewed in a planar view, the multiple first openings pass through the outer edge of the multiple outer edges of the translucent conductive film that is closest to the second outer periphery, and are not located between a first line extending in the first direction and the first outer periphery, but are located between the first line and the second outer periphery. [Section 2] Item 2. The light-emitting element according to item 1, wherein, among the plurality of first openings, the first opening closest to the extension portion in a planar view is positioned on a second straight line that passes through an outer edge of the translucent conductive film closest to the second outer periphery and extends in the second direction. [Section 3] the light-transmitting insulating film is also disposed on the first region of the first semiconductor layer and has a second opening located above the extension portion; the first electrode layer is in contact with the extension portion at the second opening, 3. The light-emitting device according to item 2, wherein the width of the second opening in the first direction is larger than the width of the second opening in the second direction. [Section 4] the first electrode layer includes a first internal electrode layer in contact with the extension portion, and a first external electrode layer disposed on the first internal electrode layer and in contact with the first internal electrode layer, the second electrode layer includes a second internal electrode layer in contact with the light-reflective conductive film, and a second external electrode layer disposed on the second internal electrode layer and in contact with the second internal electrode layer; The light-emitting element according to any one of items 1 to 3, wherein, among the plurality of first openings, the number of the first openings that overlap the first external electrode layer and the second external electrode layer in a planar view is greater than the number of the first openings that do not overlap the first external electrode layer and the second external electrode layer. [Section 5] In a plan view, the first openings include a plurality of the first openings positioned on a third straight line extending in the first direction and a plurality of the first openings positioned on a fourth straight line extending in the first direction, the third straight line being positioned closer to the first outer periphery in the second direction than the fourth straight line; 5. The light emitting device according to item 4, wherein all of the plurality of first openings positioned on the third straight line overlap the first external electrode layer or the second external electrode layer in a plan view. [Section 6] the first electrode layer includes a first internal electrode layer in contact with the extension portion, and a first external electrode layer disposed on the first internal electrode layer and in contact with the first internal electrode layer, the second electrode layer includes a second internal electrode layer in contact with the light-reflective conductive film, and a second external electrode layer disposed on the second internal electrode layer and in contact with the second internal electrode layer; 6. The light emitting device according to any one of items 1 to 5, wherein in a plan view, the plurality of first openings are not positioned between the first internal electrode layer and the second internal electrode layer. [Section 7] In a plan view, the first openings include a plurality of first openings positioned on a third straight line extending in the first direction, a plurality of first openings positioned on a fourth straight line extending in the first direction, and a plurality of first openings positioned on a fifth straight line extending in the first direction, In the second direction, the third straight line is located closer to the first outer periphery than the fourth straight line and the fifth straight line, the fourth straight line is located closer to the second outer periphery than the third straight line and the fifth straight line, and the fifth straight line is located between the third straight line and the fourth straight line, In a plan view, a first opening located at an end on the third outer periphery side among the plurality of first openings located on the third straight line, and a first opening located at an end on the third outer periphery side among the plurality of first openings located on the fourth straight line are located farther away from the third outer periphery in the first direction than a first opening located at an end on the third outer periphery side among the plurality of first openings located on the fifth straight line, The light-emitting element according to any one of items 1 to 6, wherein, in a planar view, a first opening located at an end on the fourth outer periphery side among the multiple first openings located on the third straight line, and a first opening located at an end on the fourth outer periphery side among the multiple first openings located on the fourth straight line, are positioned farther away from the fourth outer periphery in the first direction than a first opening located at an end on the fourth outer periphery side among the multiple first openings located on the fifth straight line. [Section 8] the first electrode layer includes a first internal electrode layer in contact with the extension portion, the second electrode layer includes a second internal electrode layer in contact with the light-reflective conductive film, The light emitting element further includes an insulating film disposed on the first internal electrode layer and the second internal electrode layer, the insulating film having a third opening and a fourth opening, the first electrode layer further includes a first external electrode layer disposed on the insulating film and in contact with the first internal electrode layer in the third opening; the second electrode layer further includes a second external electrode layer disposed on the insulating film and in contact with the second internal electrode layer in the fourth opening; 8. The light emitting device according to any one of items 1 to 7, wherein the first openings do not overlap with an outer edge of the third opening and an outer edge of the fourth opening in a plan view.

[0079] The above describes the embodiments of the present invention 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 belong to the scope of the present invention as long as they include the gist of the present invention. In addition, within the scope of the concept of the present invention, a person skilled in the art may come up with various modified examples and examples of modifications, and these modified examples and examples of modifications also belong to the scope of the present invention. [Explanation of symbols]

[0080] Reference Signs: 1A to 1C...light-emitting element, 10...first semiconductor layer, 10a...first surface, 10b...second surface, 11...first region, 11A...first outer periphery, 11B...second outer periphery, 11C...third outer periphery, 11D...fourth outer periphery, 11E...extension, 11Ea...end of extension, 12...second region, 12A...first partial region, 12B...second partial region, 20...active layer, 30...second semiconductor layer, 40...light-transmitting conductive film, 40a...outer edge of light-transmitting conductive film, 50...light-transmitting insulating film, 50a...first opening, 50 b...second opening, 60...light-reflective conductive film, 70...first electrode layer, 71...first internal electrode layer, 72...first external electrode layer, 80...second electrode layer, 81...second internal electrode layer, 82...second external electrode layer, 90...insulating film, 91...first insulating film, 91a...fifth opening, 91b...sixth opening, 92...second insulating film, 92a...third opening, 92b...fourth opening, 100...semiconductor structure, 200...substrate, L1...first straight line, L2...second straight line, L3...third straight line, L4...fourth straight line, L5...fifth straight line

Claims

1. A semiconductor structure including a first semiconductor layer having, in a plan view, a first region and a second region located inside the first region, an active layer disposed on the second region, and a second semiconductor layer disposed on the active layer, wherein the first region has a first outer periphery and a second outer periphery extending in a first direction, a third outer periphery and a fourth outer periphery extending in a second direction perpendicular to the first direction, and a plurality of extension portions extending from the first outer periphery in the second direction and positioned apart from each other in the first direction, and a length in the first direction of the first outer periphery and the second outer periphery is longer than a length in the second direction of the third outer periphery and the fourth outer periphery; a transparent conductive film disposed on the second semiconductor layer; a transparent insulating film disposed on the transparent conductive film and having a plurality of first openings positioned above the transparent conductive film; a light-reflecting conductive film disposed on the light-transmitting insulating film and in contact with the light-transmitting conductive film at the first opening; A first electrode layer in contact with the extension portion; a second electrode layer in contact with the light-reflective conductive film; Equipped with In a plan view, each of the plurality of extension portions has an end portion located closest to the second outer circumferential portion, the translucent conductive film has a plurality of outer edges that face the ends of the plurality of extension portions in the second direction and are spaced apart from each other in the first direction in a plan view; A light-emitting element, in which, when viewed in a planar view, the multiple first openings pass through the outer edge among the multiple outer edges of the translucent conductive film that is closest to the second outer periphery, and are not located between a first straight line extending in the first direction and the first outer periphery, but are located between the first straight line and the second outer periphery.

2. 2. The light-emitting element according to claim 1, wherein among the plurality of first openings, the first opening closest to the extension portion in a planar view is located on a second straight line that passes through an outer edge of the translucent conductive film closest to the second outer periphery and extends in the second direction.

3. the light-transmitting insulating film is also disposed on the first region of the first semiconductor layer and has a second opening located above the extension portion; the first electrode layer is in contact with the extension portion at the second opening, The light-emitting element according to claim 2 , wherein a width of the second opening in the first direction is larger than a width of the second opening in the second direction.

4. the first electrode layer includes a first internal electrode layer in contact with the extension portion, and a first external electrode layer disposed on the first internal electrode layer and in contact with the first internal electrode layer, the second electrode layer includes a second internal electrode layer in contact with the light-reflective conductive film, and a second external electrode layer disposed on the second internal electrode layer and in contact with the second internal electrode layer; A light-emitting element as described in any one of claims 1 to 3, wherein, among the plurality of first openings, the number of the first openings that overlap the first external electrode layer and the second external electrode layer in a planar view is greater than the number of the first openings that do not overlap the first external electrode layer and the second external electrode layer.

5. In a plan view, the first openings include a plurality of the first openings positioned on a third straight line extending in the first direction and a plurality of the first openings positioned on a fourth straight line extending in the first direction, the third straight line being positioned closer to the first outer periphery in the second direction than the fourth straight line; The light-emitting element according to claim 4 , wherein all of the plurality of first openings positioned on the third straight line overlap the first external electrode layer or the second external electrode layer in a plan view.

6. the first electrode layer includes a first internal electrode layer in contact with the extension portion, and a first external electrode layer disposed on the first internal electrode layer and in contact with the first internal electrode layer, the second electrode layer includes a second internal electrode layer in contact with the light-reflective conductive film, and a second external electrode layer disposed on the second internal electrode layer and in contact with the second internal electrode layer; 4. The light-emitting element according to claim 1, wherein in a plan view, the plurality of first openings are not positioned between the first internal electrode layer and the second internal electrode layer.

7. In a plan view, the first openings include a plurality of first openings positioned on a third straight line extending in the first direction, a plurality of first openings positioned on a fourth straight line extending in the first direction, and a plurality of first openings positioned on a fifth straight line extending in the first direction, In the second direction, the third straight line is located closer to the first outer periphery than the fourth straight line and the fifth straight line, the fourth straight line is located closer to the second outer periphery than the third straight line and the fifth straight line, and the fifth straight line is located between the third straight line and the fourth straight line, In a plan view, a first opening located at an end on the third outer periphery side among the plurality of first openings located on the third straight line, and a first opening located at an end on the third outer periphery side among the plurality of first openings located on the fourth straight line are located farther away from the third outer periphery in the first direction than a first opening located at an end on the third outer periphery side among the plurality of first openings located on the fifth straight line, A light-emitting element as described in any one of claims 1 to 3, wherein, in a planar view, a first opening located at the end on the fourth outer periphery side among the multiple first openings located on the third straight line, and a first opening located at the end on the fourth outer periphery side among the multiple first openings located on the fourth straight line, are located farther away from the fourth outer periphery in the first direction than a first opening located at the end on the fourth outer periphery side among the multiple first openings located on the fifth straight line.

8. the first electrode layer includes a first internal electrode layer in contact with the extension portion, the second electrode layer includes a second internal electrode layer in contact with the light-reflective conductive film, The light emitting element further includes an insulating film disposed on the first internal electrode layer and the second internal electrode layer, the insulating film having a third opening and a fourth opening, the first electrode layer further includes a first external electrode layer disposed on the insulating film and in contact with the first internal electrode layer in the third opening; the second electrode layer further includes a second external electrode layer disposed on the insulating film and in contact with the second internal electrode layer in the fourth opening; 4. The light-emitting element according to claim 1, wherein the first openings do not overlap with an outer edge of the third opening and an outer edge of the fourth opening in a plan view.

Images