Light-emitting element

Abstract

Provided is a light-emitting element capable of reducing unevenness in current density distribution. The light-emitting element includes a semiconductor structure, 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, and a light-reflective conductive film disposed on the translucent insulating film and in contact with the translucent conductive film in the first openings. In a plan view, each of the plurality of extending and protruding portions of the first semiconductor layer has an end portion located closest to the second outer peripheral portion side. In a plan view, the translucent conductive film has a plurality of outer edges that face the end portions of the plurality of extending and protruding portions in the second direction, respectively. In a plan view, the plurality of first openings are not located between a first straight line and the first outer peripheral portion, the first straight line extending in the first direction and passing through the outer edge closest to the second outer peripheral portion among the plurality of outer edges of the translucent conductive film, but between the first straight line and the second outer peripheral portion.

Description

Technical Field

[0001] The present invention relates to a light emitting element. Background Art

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

[0003] Prior art literature

[0004] Japanese Patent Application Publication No. 2016-143682 Summary of the invention

[0005] Problems to be solved by the invention

[0006] An object of the present invention is to provide a light emitting element capable of reducing uneven current density distribution.

[0007] Means for solving problems

[0008] According to one embodiment of the present invention, a light-emitting element comprises: a semiconductor structure, which, when viewed from above, comprises a first semiconductor layer, an active layer, and a second semiconductor layer, wherein the first semiconductor layer comprises a first region and a second region located inside the first region, the active layer is arranged on the second region, the second semiconductor layer is arranged on the active layer, the first region comprises a first peripheral portion and a second peripheral portion extending along a first direction, a third peripheral portion and a fourth peripheral portion extending along a second direction orthogonal to the first direction, and a plurality of peripheral portions extending from the first peripheral portion in the second direction and mutually extending in the first direction. A plurality of extended protrusions disposed separately, wherein the lengths of the first peripheral portion and the second peripheral portion in the first direction are longer than the lengths of the third peripheral portion and the fourth peripheral portion in the second direction; a light-transmitting conductive film disposed on the second semiconductor layer; a light-transmitting insulating film disposed on the light-transmitting conductive film and having a plurality of first openings located above the light-transmitting conductive film; a light-reflecting conductive film disposed on the light-transmitting insulating film and in contact with the light-transmitting conductive film in the first openings; a first electrode layer in contact with the extended protrusions; and a second electrode layer in contact with the light-reflecting conductive film. In a plan view, the plurality of extended protrusions each have an end portion located closest to the second peripheral portion. In a plan view, the light-transmitting conductive film has a plurality of outer edges, which are respectively opposed to the ends of the plurality of extended protrusions in the second direction and are disposed separately from each other in the first direction. When viewed from above, the multiple first openings are not located between a first straight line extending along the first direction and the first peripheral portion, which is the outer edge closest to the second peripheral portion among the multiple outer edges of the translucent conductive film, but are located between the first straight line and the second peripheral portion.

[0009] Effects of the Invention

[0010] According to the present invention, a light emitting element capable of reducing unevenness in current density distribution is provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic top view of a light emitting element according to an embodiment.

[0012] Figure 2A yes Figure 1 An enlarged top view of the region where the second external electrode layer is arranged.

[0013] Figure 2B yes Figure 1 An enlarged top view of the region where the first external electrode layer is arranged.

[0014] Figure 3 yes Figure 1 Schematic cross-sectional view along line III-III.

[0015] Figure 4 yes Figure 3 An enlarged cross-sectional view of a portion of.

[0016] Figure 5A This is a measurement image of the emission intensity distribution of the light emitting element of the first comparative example.

[0017] Figure 5B This is a measurement image of the emission intensity distribution of the light emitting element of the second comparative example.

[0018] Fig. 6A This is a measurement image of the emission intensity distribution of the light emitting element of the first example.

[0019] Figure 6B This is a measurement image of the emission intensity distribution of the light emitting element of the second example.

[0020] Figure 7 This is a schematic top view of the light emitting element of Comparative Example 1.

[0021] Figure 8 This is a schematic top view of the light emitting element of Comparative Example 2.

[0022] Fig. 9 This is a schematic top view of the light emitting element of Example 1.

[0023] Fig.10 It is a schematic top view of a light emitting element according to a modification example of the embodiment.

[0024] Description of Reference Numerals

[0025] 1A to 1C…light emitting element, 10…first semiconductor layer, 10a…first surface, 10b…second surface, 11…first region, 11A…first peripheral portion, 11B…second peripheral portion, 11C…third peripheral portion, 11D…fourth peripheral portion, 11E…extended protrusion, 11Ea…end portion of the extended protrusion, 12…second region, 12A…first partial region, 12B…second partial region, 20…active layer, 30…second semiconductor layer, 40…transparent conductive film, 40a…outer edge of the transparent conductive film, 50…transparent insulating film, 50a…first opening, 50b…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 DETAILED DESCRIPTION

[0026] The following describes the implementation mode with reference to the accompanying drawings. In each of the drawings, the same structure is marked with the same figure mark. It should be noted that each of the drawings schematically represents the implementation mode, and therefore the proportions, spacings or positional relationships of the components may be exaggerated, or a part of the components may be omitted. In addition, as a cross-sectional view, an end view that only shows the cross section is sometimes shown. In addition, in the cross-sectional view, in order to facilitate the identification of the boundaries between the layers of the semiconductor structure, the cross section of the semiconductor structure is not drawn with a section line.

[0027] In the following description, structural elements having substantially the same function are sometimes indicated by common reference figures, and the description is omitted. In addition, terms indicating specific directions or positions (such as "upper", "lower" and another term including them) are sometimes used. However, these terms are intended only to make it easy to distinguish the relative directions or positions in the referenced figures. If the relative directions or positional relationships indicated by the terms "upper", "lower" and the like in the referenced figures are the same, then the configurations in the drawings outside the present disclosure, actual products, etc. may not be the same as those in the referenced figures. The positional relationship of "upper" in this specification includes the situation of contact, and also includes the situation of being located above although not in contact. In addition, in this specification, unless otherwise stated, a component covering a covered object includes a situation where the component is in contact with the covered object and directly covers the covered object and a situation where the component does not contact the covered object but indirectly covers the covered object.

[0028] In the following figures, a first direction X, a second direction Y, and a third direction Z that are orthogonal to each other are shown. In the description of this specification, the arrow direction of the third direction Z is upward, and the direction on the side opposite to the arrow direction of the third direction Z is downward. In addition, "a straight line extending in the first direction X" means a straight line substantially parallel to the first direction X when viewed from above, and a straight line that deviates from the first direction X within a range of 3° is also included in the "straight line extending in the first direction X". Similarly, "a straight line extending in the second direction Y" means a straight line substantially parallel to the second direction Y when viewed from above, and a straight line that deviates from the second direction Y within a range of 3° is also included in the "straight line extending in the second direction Y".

[0029] Reference Figure 1 to Figure 4 , a light emitting element 1A according to an embodiment is described. The light emitting element 1A according to 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 structure is described below.

[0030] [Semiconductor structure]

[0031] like Figure 3 as well as Figure 4 As shown, 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 composed of a nitride semiconductor. In this specification, "nitride semiconductor" includes, for example, In x Al y Ga 1-x-y In the chemical formula of N (0≤x≤1, 0≤y≤1, x+y≤1), all semiconductors of compositions whose composition ratios x and y vary within various ranges. In addition, in the above chemical formula, components including Group V elements other than N (nitrogen) and components of various elements added to control various physical properties such as conductivity are all included in the "nitride semiconductor".

[0032] The first semiconductor layer 10 has a semiconductor layer including n-type impurities. Figure 1 As shown, in a plan view, there is a first area 11 and a second area 12 located inside the first area 11 .

[0033] The first region 11 is exposed from the active layer 20 and the second semiconductor layer 30. The first region 11 has a first peripheral portion 11A, a second peripheral portion 11B, a third peripheral portion 11C, and a fourth peripheral portion 11D. The first peripheral portion 11A and the second peripheral portion 11B extend along the first direction X. The third peripheral portion 11C and the fourth peripheral portion 11D extend along the second direction Y. The length of each of the first peripheral portion 11A and the second peripheral portion 11B in the first direction X is longer than the length of each of the third peripheral portion 11C and the fourth peripheral portion 11D in the second direction Y. In a plan view, the first peripheral portion 11A, the second peripheral portion 11B, the third peripheral portion 11C, and the fourth peripheral portion 11D continuously surround the second region 12.

[0034] The first region 11 further includes a plurality of extended protrusions 11E. The plurality of extended protrusions 11E extend from the first peripheral portion 11A toward the second peripheral portion 11B along the second direction Y. The plurality of extended protrusions 11E are disposed apart from each other in the first direction X. For example, Figure 1 , three extending protrusions 11E are shown, which are separated from each other in the first direction X. There may be two extending protrusions 11E, or four or more extending protrusions 11E. The extending protrusions 11E extend only from the first peripheral portion 11A, and do not extend from the second peripheral portion 11B, the third peripheral portion 11C, and the fourth peripheral portion 11D.

[0035] Each of the plurality of extensions 11E has an end 11Ea located closest to the second peripheral portion 11B in plan view. The end 11Ea of the extension 11E is located closer to the first peripheral portion 11A than a bisecting line that bisects the light emitting element 1A in the second direction Y in plan view.

[0036] like Figure 3 as well as Figure 4 As shown, 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 generates light, and can have an MQW (Multiple Quantumwell) structure including, for example, a plurality of barrier layers and a plurality of well layers.

[0037] The second semiconductor layer 30 is disposed on the active layer 20. The second semiconductor layer 30 has a semiconductor layer including p-type impurities.

[0038] The first semiconductor layer 10 has a first surface 10a and a second surface 10b located opposite to the first surface 10a in the third direction Z. The second surface 10b has the first region 11 and the second region 12. Light generated by the active layer 20 is mainly extracted to the outside of the semiconductor structure 100 from the first surface 10a.

[0039] The light emitting element 1A may also include a substrate 200 that supports the semiconductor structure 100. The semiconductor structure 100 is disposed on the substrate 200 so that the first semiconductor layer 10 is located on the substrate 200 side in the third direction Z. The first surface 10a of the first semiconductor layer 10 is in contact with the substrate 200. As a material for the substrate 200, for example, sapphire, spinel, GaN, SiC, ZnS, ZnO, GaAs or Si can be used. The light emitting element 1A may not include the substrate 200.

[0040] [Light-transmitting conductive film]

[0041] like Figure 3 as well as Figure 4 As shown, the light-transmitting conductive film 40 is disposed on the second semiconductor layer 30. The light-transmitting conductive film 40 is in contact with the second semiconductor layer 30 and is electrically connected to the second semiconductor layer 30. The light-transmitting 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 where the active layer 20 and the second semiconductor layer 30 are not disposed.

[0042] The light-transmitting conductive film 40 is light-transmitting with respect to the light generated by the active layer 20. The transmittance of the light-transmitting conductive film 40 with respect to the peak wavelength of the light generated by the active layer 20 is, for example, 60% or more. Thus, the absorption of light in the light-transmitting conductive film 40 can be reduced. In addition, the light-transmitting conductive film 40 can diffuse the current supplied from the second electrode layer 80 in the surface direction of the second semiconductor layer 30. Thus, the unevenness of the current density distribution can be reduced. As the material of the light-transmitting conductive film 40, for example, ITO (Indium Tin Oxide), ZnO (Zinc Oxide), In 2 O 3 (Indium Oxide), etc.

[0043] like Figure 1 to Figure 2B As shown, in a plan view, the light-transmitting conductive film 40 has a plurality of outer edges 40a at the end portions 11Ea of the plurality of extended protrusions 11E of the first semiconductor layer 10, respectively, which are opposed in the second direction Y. The plurality of outer edges 40a are separately arranged in the first direction X. The outer edges 40a of the light-transmitting conductive film 40 are separately arranged in the second direction Y from the end portions 11Ea of the extended protrusions 11E in a plan view.

[0044] [Light-transmitting insulating film]

[0045] like Figure 3 as well as Figure 4As shown, the light-transmitting insulating film 50 is disposed on the light-transmitting conductive film 40. The light-transmitting insulating film 50 has a plurality of first openings 50a located above the light-transmitting conductive film 40. In the first openings 50a, the light-transmitting conductive film 40 is not covered by the light-transmitting insulating film 50 but is exposed from the light-transmitting insulating film 50.

[0046] By total reflection at the interface between the light-transmitting insulating film 50 and the light-transmitting conductive film 40, a portion of the light radiated from the active layer 20 to the second semiconductor layer 30 side can be emitted to the main light extraction surface, that is, the first surface 10a side of the first semiconductor layer 10. As the light-transmitting insulating film 50, for example, a single-layer film of a silicon oxide film can be used. Alternatively, as the light-transmitting insulating film 50, a dielectric multilayer film can be used.

[0047] [Light-reflective conductive film]

[0048] like Figure 3 as well as Figure 4 As shown, the light reflective conductive film 60 is disposed on the light transmissive insulating film 50. The light reflective conductive film 60 is in contact with the light transmissive conductive film 40 at the first opening 50a of the light transmissive insulating film 50. The light reflective conductive film 60 is electrically connected to the light transmissive conductive film 40 at the first opening 50a.

[0049] 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 pass through the light-transmitting insulating film 50 and be reflected toward the first surface 10a side at the light-reflective conductive film 60. The reflectivity of the light-reflective conductive film 60 relative to the peak wavelength of the light generated by the active layer 20 is, for example, 60% or more. The light-reflective conductive film 60 preferably includes, for example, silver or aluminum. The light-reflective conductive film 60 may also include nickel, titanium, platinum, or the like. The light-reflective conductive film 60 may be a single-layer structure or a stacked structure in which a plurality of metal films are stacked.

[0050] [First electrode layer]

[0051] like Figure 3 As shown, the first electrode layer 70 is in contact with the extended protrusion 11E of the first semiconductor layer 10. The first electrode layer 70 is electrically connected to the first semiconductor layer 10 via the extended protrusion 11E. As the material of the first electrode layer 70, for example, titanium, platinum, gold, aluminum, copper, etc. can be used. The first electrode layer 70 can also be a single-layer structure or a stacked structure in which a plurality of metal films are stacked.

[0052] The number of first openings 50a of the transparent 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 transparent conductive film 40 are in contact is greater than the number of portions where the first electrode layer 70 and the first semiconductor layer 10 are in contact.

[0053] [Second electrode layer]

[0054] 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 transmissive conductive film 40. As a material for the second electrode layer 80, for example, the same material as that of the first electrode layer 70 can be used. The second electrode layer 80 may have a single-layer structure or a stacked structure in which a plurality of metal films are stacked.

[0055] When a forward voltage is applied between the first electrode layer 70 and the second electrode layer 80 in such a manner that the potential of the second electrode layer 80 is higher than the potential of the first electrode layer 70, current flows from the second electrode layer 80 to the first electrode layer 70 via the light-reflective conductive film 60, the light-transmitting conductive film 40, and the semiconductor structure 100. By supplying current to the active layer 20, the active layer 20 emits light.

[0056] like Figure 1 to Figure 2B As shown, in a plan view, a straight line passing through the outer edge 40a of the plurality of outer edges 40a of the light-transmitting conductive film 40, which is closest to the second outer peripheral portion 11B of the first semiconductor layer 10, and extending in the first direction X is defined as the 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 portion of the first straight line L1 overlaps with the outer edge 40a of the light-transmitting conductive film 40 which is closest to the second outer peripheral portion 11B in a plan view.

[0057] In a plan view, the plurality of first openings 50a of the light-transmitting insulating film 50 are not located between the first straight line L1 and the first peripheral portion 11A, but are located between the first straight line L1 and the second peripheral portion 11B. In a plan view, the first openings 50a are located in the first partial region 12A surrounded by the first straight line L1, the second peripheral portion 11B, the third peripheral portion 11C, and the fourth peripheral portion 11D in the second region 12. The first openings 50a are not located in the second partial region 12B surrounded by the first straight line L1, the first peripheral portion 11A, the third peripheral portion 11C, and the fourth peripheral portion 11D in the second region 12. The end 11Ea of the extended protrusion 11E is located in the second partial region 12B. The area of ​​the first partial region 12A is wider than the area 12B of the second partial region.

[0058] The first opening 50a serves as an inflow portion for current into the semiconductor structure 100, and the extension 11E serves as an outflow portion for current from the semiconductor structure 100. Among the plurality of first openings 50a, current tends to concentrate at the first opening 50a relatively close to the extension 11E in plan view.

[0059] Reference Figure 7 as well as Figure 8 In the comparative example described later, the first opening 50a is also located between the first straight line L1 and the first peripheral portion 11A. In this comparative example, the current is easily concentrated in the semiconductor structure 100 below the first opening 50a near the extended protrusion 11E in the region between the first straight line L1 and the first peripheral portion 11A. In the region including the active layer 20 and the second semiconductor layer 30 of the semiconductor structure 100, the portion where the current is concentrated has a relatively high luminous intensity, which may cause uneven luminous intensity distribution of the light-emitting element.

[0060] According to the present embodiment, by making the first opening 50a not located between the first straight line L1 and the first outer peripheral portion 11A, the concentration of current on the semiconductor structure 100 below the first opening 50a close to the extended protrusion 11E can be reduced compared to the comparative example, and the unevenness of the current density distribution in the semiconductor structure 100 can be reduced. As a result, the unevenness of the light emission intensity distribution of the light emitting element 1A can be reduced. In addition, the semiconductor structure 100 below the first opening 50a close to the extended protrusion 11E is less likely to be deteriorated or destroyed by heat.

[0061] In addition, according to the present embodiment, in the region where the luminous intensity is likely to be high between the first straight line L1 and the first peripheral portion 11A, the first opening 50a is not arranged, so that the light-transmitting insulating film 50 is in contact with the light-transmitting conductive film 40. Therefore, light with high luminous intensity can be totally reflected at the interface between the light-transmitting insulating film 50 and the light-transmitting conductive film 40, and the brightness of the light taken out from the first surface 10a can be increased.

[0062] like Figure 2A as well as Figure 2B As shown in FIG. 1 , a straight line passing through the outer edge 40a of the light-transmitting conductive film 40 closest to the second peripheral portion 11B and extending in the second direction Y is referred to as the second straight line L2. In addition, a straight line near the first straight line L1 and extending in the first direction X is referred to as the third straight line L3 when viewed from above. When viewed from above, the third straight line L3 is located between the first straight line L1 and the second peripheral portion 11B. The distance between the third straight line L3 and the first straight line L1 in the second direction Y is shorter than the distance between the third straight line L3 and the second peripheral portion 11B in the second direction Y.

[0063] In addition, the straight lines extending in the first direction X at a position separated from the first straight line L1 in the second direction Y by the third straight line L3 are referred to as the fourth straight line L4 and the fifth straight line L5. In the second direction Y, the third straight line L3 is located closer to the first outer peripheral portion 11A than the fourth straight line L4 and the fifth straight line L5. In the second direction Y, the fourth straight line L4 is located closer to the second outer peripheral portion 11B than the third straight line L3 and the fifth straight line L5. In the second direction Y, the fifth straight line L5 is located between the third straight line L3 and the fourth straight line L4.

[0064] In a plan view, the plurality of first openings 50 a are located on the third straight line L3 , the plurality of first openings 50 a are located on the fourth straight line L4 , and the plurality of first openings 50 a are located on the fifth straight line L5 .

[0065] The third straight line L3 is closer to the extension portion 11E than the fourth straight line L4 and the fifth straight line L5 in the second direction Y. When the first opening 50a closest to the extension portion 11E in a plan view among the plurality of first openings 50a is located on the third straight line L3 as described above, current is easily concentrated in the semiconductor structure 100 below the first opening 50a.

[0066] Therefore, among the plurality of first openings 50a, the first opening 50a1 closest to the extension protrusion 11E when viewed from above is preferably located on the second straight line L2 (it should be noted that this excludes the intersection of the second straight line L2 and the third straight line L3). Thus, compared with the case where the first opening 50a closest to the extension protrusion 11E when viewed from above is located on the third straight line L3, the concentration of current on the semiconductor structure 100 below the first opening 50a1 closest to the extension protrusion 11E can be reduced, and the unevenness of the current density distribution can be reduced. Figure 2A as well as Figure 2B In the illustrated example, the first opening 50a1 closest to the extending protrusion 11E is located on the fifth straight line L5 in a plan view.

[0067] like Figure 3 As shown, 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 peripheral portion 11A, the second peripheral portion 11B, the third peripheral portion 11C, and the fourth peripheral portion 11D.

[0068] The light-transmitting insulating film 50 has a second opening 50b located above the extension 11E. The light-transmitting insulating film 50 has a plurality of second openings 50b corresponding to the plurality of extensions 11E. The first electrode layer 70 is in contact with the extension 11E at the second opening 50b.

[0069] In a structure where the first opening 50a1 closest to the extended protrusion 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 greater than the width of the second opening 50b in the second direction Y. Figure 1 to Figure 2B As shown, when viewed from above, the shape of the second opening 50b is an oval shape that is long in the first direction X. Alternatively, when viewed from above, the shape of the second opening 50b may also be a rectangular shape that is long in the first direction X. When viewed from above, the first opening 50a1 located on the second straight line L2 and closest to the extended protrusion 11E is opposite to the long side of the second opening 50b of the above shape. Thus, compared with the case where the first opening 50a1 closest to the extended protrusion 11E is opposite to the corner of the second opening 50b, the concentration of current on the semiconductor structure 100 below the first opening 50a1 closest to the extended protrusion 11E can be reduced.

[0070] As described above, the second opening 50b that is long in the first direction X can easily reduce the angle between the side surface of the light-transmitting insulating film 50 defining the second opening 50b and the lower surface of the light-transmitting insulating film 50, compared with the second opening 50b that is circular or square in plan view. As a result, it is easy to increase the film thickness of the light-reflective conductive film 60 covering the side surface of the light-transmitting insulating film 50, and the reliability of the light-reflective conductive film 60 can be improved. According to the present embodiment, the angle between the side surface of the light-transmitting insulating film 50 defining 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.

[0071] Among the plurality of first openings 50a arranged on the third straight line L3 closer to the extension protrusion 11E in the second direction Y than the fourth straight line L4 and the fifth straight line L5, the first opening 50a2 closest to the extension protrusion 11E when viewed from above is preferably a plurality. The shortest distance between each of these plurality of first openings 50a2 and the extension protrusion 11E when viewed from above is substantially the same distance. Thus, the current concentration in the semiconductor structure 100 below one first opening 50a2 can be reduced. It should be noted that "substantially the same distance" means that the difference in distance is within 3 μm.

[0072] like Figure 3 As shown, the first electrode layer 70 can include a first internal electrode layer 71 and a first external electrode layer 72, and the second electrode layer 80 can include a second internal electrode layer 81 and a second external electrode layer 82. Figure 1 As shown, the first external electrode layer 72 and the second external electrode layer 82 are arranged to separate the light emitting element 1A in the first direction X across a bisecting line that bisects the light emitting element 1A in the first direction X when viewed from above. The first external electrode layer 72 and the second external electrode layer 82 are electrically connected to a wiring member of a wiring substrate on which the light emitting element 1A is mounted, for example, via a conductive member such as solder.

[0073] The first internal electrode layer 71 is arranged above the second region 12 of the first semiconductor layer 10, in other words, the 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 arranged in the extended protrusion 11E of the first region 11 of the first semiconductor layer 10, and is in contact with the extended protrusion 11E. The first external electrode layer 72 is arranged 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.

[0074] 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 transmissive conductive film 40.

[0075] like Figure 1 As shown, among the plurality of 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 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 in a plan view. Thus, the heat accompanying the light emission of the active layer 20 can be dissipated to a wiring substrate or the like on which the light-emitting element 1A is mounted via the light-transmitting conductive film 40, the light-reflective conductive film 60 in contact with the light-transmitting conductive film 40 in 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-reflective conductive film 60, but is disposed on the light-reflective conductive film 60 via an insulating film described later, and heat is transferred from the light-reflective conductive film 60 to the first internal electrode layer 71 via the insulating film.

[0076] In particular, since the temperature is likely to be high in the region where the light emission intensity is likely to be enhanced near the extended protrusion 11E, even among the plurality of first openings 50a, all of the plurality of first openings 50a located on the third straight line L3 near the extended protrusion 11E are preferably overlapped on the first external electrode layer 72 or the second external electrode layer 82 in a plan view. Thus, the heat accompanying the light emission of the active layer 20 can be effectively dissipated.

[0077] Preferably, when viewed from above, the multiple first openings 50a are not located in the area 300 between the first internal electrode layer 71 and the second internal electrode layer 81, so that the heat accompanying the light emission of the active layer 20 can be effectively transferred to the first internal electrode layer 71 or the second internal electrode layer 81 composed of a metal material with higher thermal conductivity than the insulating film.

[0078] At the corners of the light emitting element 1A in plan view, light radiated from the active layer 20 toward the first surface 10 a or side surfaces of the first semiconductor layer 10 is easily reflected by the first surface 10 a or side surfaces and returns into the semiconductor structure 100 .

[0079] Therefore, if Figure 2A As shown, when viewed from above, the first opening 50a at the end portion located on the third peripheral portion 11C side among the plurality of first openings 50a located on the third straight line L3 and the first opening 50a at the end portion located on the third peripheral portion 11C side among the plurality of first openings 50a located on the fourth straight line L4 are preferably arranged to be further separated from the third peripheral portion 11C along the first direction X than the first opening 50a at the end portion located on the third peripheral portion 11C side among the plurality of first openings 50a located on the fifth straight line L5. In other words, when viewed from above, the first opening 50a is not located near the two corner portions on the third peripheral portion 11C side. Thus, the return light reflected by the two corner portions on the third peripheral portion 11C side is totally reflected at the interface between the light-transmitting insulating film 50 and the light-transmitting conductive film 40, and the brightness of the light taken out from the first surface 10a can be increased.

[0080] Likewise, if Figure 2B As shown, when viewed from above, the first opening 50a at the end portion located on the fourth peripheral portion 11D side among the plurality of first openings 50a located on the third straight line L3 and the first opening 50a at the end portion located on the fourth peripheral portion 11D side among the plurality of first openings 50a located on the fourth straight line L4 are preferably arranged to be further separated from the fourth peripheral portion 11D along the first direction X than the first opening 50a at the end portion located on the fourth peripheral portion 11D side among the plurality of first openings 50a located on the fifth straight line L5. In other words, when viewed from above, the first opening 50a is not located near the two corner portions on the fourth peripheral portion 11D side. As a result, the return light reflected by the two corner portions on the fourth peripheral portion 11D side is totally reflected at the interface between the light-transmitting insulating film 50 and the light-transmitting conductive film 40, and the brightness of the light taken out from the first surface 10a can be increased.

[0081] like Figure 3 as well as Figure 4As shown, 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 include 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, silicon oxide films may be used.

[0082] 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 is in contact with the light-reflective conductive film 60 at the fifth opening 91a of the first insulating film 91.

[0083] The first insulating film 91 has a sixth opening 91b located above the extension 11E and continuous with the second opening 50b of the translucent insulating film 50. The first internal electrode layer 71 is in contact with the extension 11E in the sixth opening 91b of the first insulating film 91 and the second opening 50b of the translucent insulating film 50.

[0084] The first insulating film 91 is arranged 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 .

[0085] The second insulating film 92 is arranged on the first insulating film 91, the first internal electrode layer 71, and the second internal electrode layer 81. The second insulating film 92 is arranged in a region 300 between the first internal electrode layer 71 and the second internal electrode layer 81 in a plan view.

[0086] 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 is in contact with the first internal electrode layer 71 in the third opening 92a.

[0087] 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 is in contact with the second internal electrode layer 81 in the fourth opening 92b.

[0088] like Figure 4As shown, the upper surface of the light-reflective conductive film 60 located above the first opening 50a of the light-transmitting insulating film 50 is easily recessed compared to the upper surface of the light-reflective conductive film 60 located on the light-transmitting insulating film 50 without the first opening 50a. In the insulating film 90 stacked on the light-reflective conductive film 60, the position above the recess of the light-reflective conductive film 60 is easily recessed. Therefore, when the plurality of first openings 50a of the light-transmitting insulating film 50 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 in a plan view, the side surface of the second insulating film 92 that determines the third opening 92a and the fourth opening 92b is deformed in a manner that is easy to be recessed. When the side surface of the second insulating film 92 is deformed, the second insulating film 92 is easily cracked due to thermal stress.

[0089] Therefore, in a plan view, the plurality of first openings 50a of the light-transmitting insulating film 50 preferably do not overlap with the outer edges of the third openings 92a and the fourth openings 92b of the second insulating film 92. This makes it difficult for cracks to form in the second insulating film 92.

[0090] Next, the results of measuring the emission intensity distribution of Examples and Comparative Examples will be described.

[0091] Figure 5A About Figure 7 1 is a measurement image of the emission intensity distribution of the light emitting element 2A of the first comparative example.

[0092] Figure 5B About Figure 8 1 is a measurement image of the emission intensity distribution of the light emitting element 2B of the second comparative example.

[0093] Figure 7 The light emitting element 2A of the first comparative example shown and Figure 8 The light emitting element 2B of the second comparative example shown is different from the light emitting element 1A of the above-mentioned embodiment in that the first opening 50a is also located between the first straight line L1 and the first peripheral portion 11A in a plan view. It should be noted that in the light emitting element 2A of the first comparative example and the light emitting element 2B of the second comparative example, the shape and number of the fifth opening 91a of the first insulating film 91 and the fourth opening 92b of the second insulating film 92 in a plan view are different from those of the light emitting element 1A of the embodiment, but these designs have almost no effect on reducing the unevenness of the light emitting intensity distribution.

[0094] Fig. 6A About Fig. 9 FIG. 1 is a measurement image of the emission intensity distribution of the light emitting element 1B according to the first embodiment.

[0095] Fig. 9The light emitting element 1B of the first embodiment shown is similar to the light emitting element 1A of the embodiment, and the first opening 50a is not located between the first straight line L1 and the first peripheral portion 11A in a plan view. It should be noted that the shape and number of the fifth opening 91a of the first insulating film 91 and the fourth opening 92b of the second insulating film 92 in a plan view in the light emitting element 1B of the first embodiment are different from those of the light emitting element 1A of the embodiment.

[0096] Figure 6B It is about having Figure 1 to Figure 4 FIG. 1 is a measurement image of the emission intensity distribution of the light emitting element 1A of the second embodiment having the above-described configuration.

[0097] Figures 5A to 6A This is a measurement image of the emission intensity distribution of the light emitting element when a current of 70 mA was passed. Figure 6B This is a measurement image of the luminous intensity distribution of the light-emitting element when a current of 20 mA is flowing. Figure 5A to Figure 6B In each figure, the luminous intensity distribution is represented by grayscale. In this grayscale, the higher the brightness, the stronger the luminous intensity.

[0098] according to Figure 5A to Figure 6B The results shown in the figure show that the light emitting element 1B of the first embodiment and the light emitting element 1A of the second embodiment have less unevenness in the luminous intensity distribution than the light emitting element 2A of the first comparative example and the light emitting element 2B of the second comparative example. Since the luminous 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 the unevenness in the current density distribution compared with the light emitting element 2A of the first comparative example and the light emitting element 2B of the second comparative example.

[0099] Fig.10 It is a schematic plan view of a light emitting element 1C according to a modification of the embodiment.

[0100] according to Fig.10 The light emitting element 1C shown in FIG. Figure 1 Compared with the light emitting element 1A shown, the number of the first openings 50 a arranged around the extending protrusion 11E is greater, and therefore the unevenness of the current density distribution can be more easily reduced.

[0101] The embodiments of the present invention are described above with reference to specific examples. However, the present invention is not limited to these specific examples. Based on the above-mentioned embodiments of the present invention, all the ways obtained by those skilled in the art through appropriate design changes are within 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, various variations and modifications can be thought of by those skilled in the art, and these variations and modifications are within the scope of the present invention.

Claims

1. A light emitting element, comprising: A semiconductor structure, which, when viewed from above, comprises a first semiconductor layer, an active layer and a second semiconductor layer, wherein the first semiconductor layer comprises a first region and a second region located inside the first region, the active layer is arranged on the second region, and the second semiconductor layer is arranged on the active layer, the first region comprises a first peripheral portion and a second peripheral portion extending along a first direction, a third peripheral portion and a fourth peripheral portion extending along a second direction orthogonal to the first direction, and a plurality of extending protrusions extending from the first peripheral portion along the second direction and being arranged apart from each other in the first direction, wherein the lengths of the first peripheral portion and the second peripheral portion in the first direction are longer than the lengths of the third peripheral portion and the fourth peripheral portion in the second direction; a light-transmitting conductive film disposed on the second semiconductor layer; a light-transmitting insulating film disposed on the light-transmitting conductive film and having a plurality of first openings located above the light-transmitting conductive film; a light-reflective conductive film disposed on the light-transmitting insulating film and in contact with the light-transmitting conductive film in the first opening; a first electrode layer connected to the extended protrusion; a second electrode layer in contact with the light-reflective conductive film; In a plan view, each of the plurality of extending protrusions has an end portion located closest to the second outer peripheral portion. The light-transmitting conductive film has a plurality of outer edges in a plan view, the plurality of outer edges are respectively opposed to the end portions of the plurality of extending protrusions in the second direction and are disposed apart from each other in the first direction. When viewed from above, the multiple first openings are not located between a first straight line extending along the first direction and the first peripheral portion, which is the outer edge closest to the second peripheral portion among the multiple outer edges of the translucent conductive film, but are located between the first straight line and the second peripheral portion.

2. The light emitting element according to claim 1, Among the plurality of first openings, a first opening closest to the extending protrusion in a plan view is located on a second straight line that passes through an outer edge of the light-transmitting conductive film closest to the second outer peripheral portion and extends in the second direction.

3. The light-emitting element according to claim 2, The light-transmitting insulating film is further disposed on the first region of the first semiconductor layer and has a second opening located above the extending protrusion. The first electrode layer is in contact with the extended protrusion in the second opening, A width of the second opening in the first direction is greater than a width of the second opening in the second direction.

4. The light-emitting element according to any one of claims 1 to 3, The first electrode layer comprises: a first internal electrode layer connected to the extended protrusion; 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; a second external electrode layer disposed on the second internal electrode layer and in contact with the second internal electrode layer; Among the plurality of first openings, the number of the first openings overlapping the first external electrode layer and the second external electrode layer is greater than the number of the first openings not overlapping the first external electrode layer and the second external electrode layer in a plan view.

5. The light emitting element according to claim 4, In a plan view, the plurality of first openings include: a plurality of first openings located on a third straight line extending along the first direction; a plurality of first openings located on a fourth straight line extending along the first direction; the third straight line is located closer to the first peripheral portion in the second direction than the fourth straight line, All of the plurality of first openings located on the third straight line overlap with the first external electrode layer or the second external electrode layer in a plan view.

6. The light-emitting element according to any one of claims 1 to 3, The first electrode layer comprises: a first internal electrode layer connected to the extended protrusion; 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; a second external electrode layer disposed on the second internal electrode layer and in contact with the second internal electrode layer; In a plan view, the plurality of first openings are not located between the first internal electrode layer and the second internal electrode layer.

7. The light-emitting element according to any one of claims 1 to 3, When viewed from above, the plurality of first openings include: a plurality of first openings located on a third straight line extending along the first direction; a plurality of the first openings located on a fourth straight line extending along the first direction; a plurality of the first openings located on a fifth straight line extending along 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, the first opening at the end portion located on the third outer peripheral portion side among the plurality of first openings located on the third straight line and the first opening at the end portion located on the third outer peripheral portion side among the plurality of first openings located on the fourth straight line are disposed apart from the third outer peripheral portion along the first direction compared to the first opening at the end portion located on the third outer peripheral portion side among the plurality of first openings located on the fifth straight line, When viewed from above, the first opening at the end located on the fourth peripheral portion side among the plurality of first openings located on the third straight line and the first opening at the end located on the fourth peripheral portion side among the plurality of first openings located on the fourth straight line are separated from the fourth peripheral portion along the first direction compared to the first opening at the end located on the fourth peripheral portion side among the plurality of first openings located on the fifth straight line.

8. The light-emitting element according to any one of claims 1 to 3, The first electrode layer includes a first internal electrode layer connected to the extended protrusion, 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 and 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 connected to 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 connected to the second internal electrode layer in the fourth opening. In a plan view, the plurality of first openings do not overlap with outer edges of the third opening and outer edges of the fourth opening.

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