Light-emitting element

Abstract

The present invention provides a light-emitting element that can reduce current concentration around the n-pad electrode while also reducing the increase in forward voltage. [Solution] The light-emitting element comprises a substrate, a semiconductor structure, an n electrode, a p electrode, an n pad electrode, and a p pad electrode. The n electrode has first to third n electrode regions. The p electrode has first to third p electrode regions. The first region of the n-type semiconductor layer of the semiconductor structure has a first portion located between the first n electrode region and the third p electrode region, a second portion located between the second n electrode region and the third p electrode region, a third portion located between the first p electrode region and the third n electrode region, and a fourth portion located between the second p electrode region and the third n electrode region. The first and second portions have a first groove that is recessed downwards. The third portion does not have a first groove.

Description

Technical Field

[0001] Embodiments relate to light-emitting elements.

Background Art

[0002] In a light-emitting element, current concentration may occur around an n-pad electrode. As a means to solve this, by arranging a groove in the semiconductor structure around the n-pad electrode, it is conceivable to lengthen the current path (that is, make it difficult for current to flow) around the n-pad electrode. However, if a groove is arranged so as to surround the n electrode, there is a risk that the forward voltage will increase.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of embodiments is to provide a light-emitting element capable of reducing current concentration around an n-pad electrode while reducing an increase in forward voltage.

Means for Solving the Problems

[0005] A light-emitting element according to one embodiment of the present invention comprises a substrate, a semiconductor structure, an n electrode, a p electrode, an n pad electrode, and a p pad electrode. The substrate has a first edge and a second edge. The first edge extends in a first direction when viewed from above. The second edge is parallel to the first edge. The semiconductor structure has an n-type semiconductor layer, an active layer, and a p-type semiconductor layer. The n-type semiconductor layer is disposed on the substrate. The n-type semiconductor layer has a first region and a second region when viewed from above. The active layer is disposed on the second region. The p-type semiconductor layer is disposed on the active layer. The n electrode is disposed on the first region. The p electrode is disposed on the p-type semiconductor layer. The n pad electrode is disposed on the n electrode. The n pad electrode is positioned closer to the first edge than to the second edge when viewed from above. The p pad electrode is disposed on the p electrode. The p-pad electrode is positioned closer to the second side than the first side when viewed from above. The n-electrode has a first n-electrode region, a second n-electrode region, and a third n-electrode region. The first n-electrode region extends in the first direction and overlaps with the n-pad electrode when viewed from above. The second n-electrode region extends from the first n-electrode region in the second direction and overlaps with the n-pad electrode when viewed from above. The second direction is perpendicular to the first direction. The third n-electrode region extends from the second n-electrode region in the second direction when viewed from above and does not overlap with the n-pad electrode. The p-electrode has a first p-electrode region, a second p-electrode region, and a third p-electrode region. The first p-electrode region extends in the first direction and overlaps with the p-pad electrode when viewed from above. The second p-electrode region extends from the first p-electrode region in the second direction and overlaps with the p-pad electrode when viewed from above. The third p electrode region extends from the second p electrode region in the second direction in a top view and does not overlap with the p pad electrode. The second p electrode region is aligned with the third n electrode region in the first direction. The third p electrode region is aligned with the second n electrode region in the first direction. The first region has a first part, a second part, a third part, and a fourth part. The first part is located between the first n electrode region and the third p electrode region in a top view.The second portion is located between the second n electrode region and the third p electrode region in a top view. The third portion is located between the first p electrode region and the third n electrode region in a top view. The fourth portion is located between the second p electrode region and the third n electrode region in a top view. The first and second portions are provided with a first groove that is recessed downwards. The third portion does not have the first groove.

[0006] A light-emitting element according to one embodiment of the present invention comprises a substrate, a semiconductor structure, an n electrode, a p electrode, an n pad electrode, and a p pad electrode. The substrate has a first edge and a second edge. The first edge extends in a first direction when viewed from above. The second edge is parallel to the first edge. The semiconductor structure has an n-type semiconductor layer, an active layer, and a p-type semiconductor layer. The n-type semiconductor layer is disposed on the substrate. The n-type semiconductor layer has a first region and a second region when viewed from above. The active layer is disposed on the second region. The p-type semiconductor layer is disposed on the active layer. The n electrode is disposed on the first region. The p electrode is disposed on the p-type semiconductor layer. The n pad electrode is disposed on the n electrode. The n pad electrode is positioned closer to the first edge than to the second edge when viewed from above. The p pad electrode is disposed on the p electrode. The p-pad electrode is positioned closer to the second side than the first side when viewed from above. The n-electrode has a first n-electrode region, a second n-electrode region, and a third n-electrode region. The first n-electrode region extends in the first direction and overlaps with the n-pad electrode when viewed from above. The second n-electrode region extends from the first n-electrode region in the second direction and overlaps with the n-pad electrode when viewed from above. The second direction is perpendicular to the first direction. The third n-electrode region extends from the second n-electrode region in the second direction when viewed from above and does not overlap with the n-pad electrode. The p-electrode has a first p-electrode region, a second p-electrode region, and a third p-electrode region. The first p-electrode region extends in the first direction and overlaps with the p-pad electrode when viewed from above. The second p-electrode region extends from the first p-electrode region in the second direction and overlaps with the p-pad electrode when viewed from above. The third p electrode region extends from the second p electrode region in the second direction in a top view and does not overlap with the p pad electrode. The second p electrode region is aligned with the third n electrode region in the first direction. The third p electrode region is aligned with the second n electrode region in the first direction. The first region has a first part, a second part, a third part, and a fourth part. The first part is located between the first n electrode region and the third p electrode region in a top view.The second portion is located between the second n electrode region and the third p electrode region in a top view. The third portion is located between the first p electrode region and the third n electrode region in a top view. The fourth portion is located between the second p electrode region and the third n electrode region in a top view. The first and second portions are provided with a first groove that is recessed downwards. At least one of the third and fourth portions is provided with a second groove that is recessed downwards. The depth of the second groove is less than the depth of the first groove.

[0007] A light-emitting element according to one embodiment of the present invention comprises a substrate, a semiconductor structure, an n electrode, a p electrode, an n pad electrode, and a p pad electrode. The substrate has a first edge and a second edge. The first edge extends in a first direction when viewed from above. The second edge is parallel to the first edge. The semiconductor structure has an n-type semiconductor layer, an active layer, and a p-type semiconductor layer. The n-type semiconductor layer is disposed on the substrate. The n-type semiconductor layer has a first region and a second region when viewed from above. The active layer is disposed on the second region. The p-type semiconductor layer is disposed on the active layer. The n electrode is disposed on the first region. The p electrode is disposed on the p-type semiconductor layer. The n pad electrode is disposed on the n electrode. The n pad electrode is positioned closer to the first edge than to the second edge when viewed from above. The p pad electrode is disposed on the p electrode. The p-pad electrode is positioned closer to the second side than the first side when viewed from above. The n-electrode has a first n-electrode region, a second n-electrode region, and a third n-electrode region. The first n-electrode region extends in the first direction and overlaps with the n-pad electrode when viewed from above. The second n-electrode region extends from the first n-electrode region in the second direction and overlaps with the n-pad electrode when viewed from above. The second direction is perpendicular to the first direction. The third n-electrode region extends from the second n-electrode region in the second direction when viewed from above and does not overlap with the n-pad electrode. The p-electrode has a first p-electrode region, a second p-electrode region, and a third p-electrode region. The first p-electrode region extends in the first direction and overlaps with the p-pad electrode when viewed from above. The second p-electrode region extends from the first p-electrode region in the second direction and overlaps with the p-pad electrode when viewed from above. The third p electrode region extends from the second p electrode region in the second direction in a top view and does not overlap with the p pad electrode. The second p electrode region is aligned with the third n electrode region in the first direction. The third p electrode region is aligned with the second n electrode region in the first direction. The first region has a first part, a second part, a third part, and a fourth part. The first part is located between the first n electrode region and the third p electrode region in a top view.The second portion is located between the second n electrode region and the third p electrode region in a top view. The third portion is located between the first p electrode region and the third n electrode region in a top view. The fourth portion is located between the second p electrode region and the third n electrode region in a top view. The first portion and the second portion are provided with a first groove that is recessed downwards. At least one of the third portion and the fourth portion is provided with a second groove that is recessed downwards. The width of the second groove in the first direction is smaller than the width of the first groove in the first direction. [Effects of the Invention]

[0008] According to one embodiment of the present invention, it is possible to realize a light-emitting element that can reduce current concentration around the n-pad electrodes while also reducing the increase in forward voltage. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic plan view showing a light-emitting element according to the first embodiment. [Figure 2] This is a schematic cross-sectional view showing a light-emitting element according to the first embodiment. [Figure 3] This is a schematic cross-sectional view showing a light-emitting element according to the first embodiment. [Figure 4] This is a schematic cross-sectional view showing a light-emitting element according to the first embodiment. [Figure 5] This is a schematic plan view showing a light-emitting element according to a first modified example of the first embodiment. [Figure 6] This is a schematic cross-sectional view showing a light-emitting element according to a first modified example of the first embodiment. [Figure 7] This is a schematic cross-sectional view showing a light-emitting element according to a first modified example of the first embodiment. [Figure 8] This is a schematic cross-sectional view showing a light-emitting element according to a first modified example of the first embodiment. [Figure 9] This is a schematic plan view showing a light-emitting element according to a second modified example of the first embodiment. [Figure 10]It is a plan view schematically showing a light-emitting element according to a third modification of the first embodiment. [Figure 11] It is a plan view schematically showing a light-emitting element according to a fourth modification of the first embodiment. [Figure 12] It is a plan view schematically showing a light-emitting element according to the second embodiment. [Figure 13] It is a cross-sectional view schematically showing a light-emitting element according to the second embodiment. [Figure 14] It is a cross-sectional view schematically showing a light-emitting element according to the second embodiment. [Figure 15] It is a cross-sectional view schematically showing a light-emitting element according to the second embodiment. [Figure 16] It is a plan view schematically showing a light-emitting element according to a first modification of the second embodiment. [Figure 17] It is a plan view schematically showing a light-emitting element according to a second modification of the second embodiment. [Figure 18] It is a plan view schematically showing a light-emitting element according to a third modification of the second embodiment. [Figure 19] It is a plan view schematically showing a light-emitting element according to a fourth modification of the second embodiment. [Figure 20] It is a plan view schematically showing a light-emitting element according to a fifth modification of the second embodiment. [Figure 21] It is a plan view schematically showing a light-emitting element according to the third embodiment. [Figure 22] It is a cross-sectional view schematically showing a light-emitting element according to the third embodiment. [Figure 23] It is a cross-sectional view schematically showing a light-emitting element according to the third embodiment. [Figure 24] It is a cross-sectional view schematically showing a light-emitting element according to the third embodiment. [Figure 25] It is a cross-sectional view schematically showing a light-emitting element according to a fifth modification of the first embodiment.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, each embodiment of the present invention will be described with reference to the drawings. Drawings are schematic or conceptual, and the relationships between the thickness and width of each part, as well as the ratios of the sizes of different parts, are not necessarily identical to those of reality. Even when representing the same part, the dimensions and ratios may differ between drawings. In this specification and the figures, elements similar to those already described are denoted by the same reference numerals, and detailed explanations are omitted as appropriate. In addition, in some cases, end views showing only the cross-section are shown as cross-sectional views.

[0011] Furthermore, in order to make the explanation easier to understand, the arrangement and configuration of each part will be described using the XYZ Cartesian coordinate system. The X, Y, and Z axes are mutually orthogonal. The direction in which the X axis extends will be referred to as the "X direction," the direction in which the Y axis extends as the "Y direction," and the direction in which the Z axis extends as the "Z direction." Also, in order to make the explanation easier to understand, the direction of the arrow in the Z direction will be referred to as upward, and the opposite direction as downward, but these directions are unrelated to the direction of gravity. Viewing from above downwards will be referred to as the "top view." The length in the Z direction will be referred to as the "thickness." Furthermore, in each of the following embodiments, the first direction will be the Y direction, and the second direction will be the X direction. Furthermore, a diagram of the light-emitting element observed from a top view will be referred to as the "plan view."

[0012] <First Embodiment> Figure 1 is a schematic plan view showing a light-emitting element according to the first embodiment. Figures 2 to 4 are schematic cross-sectional views showing a light-emitting element according to the first embodiment. Figure 2 is a cross-sectional view taken along the line II-II shown in Figure 1. Figure 3 is a cross-sectional view taken along the line III-III shown in Figure 1. Figure 4 is a cross-sectional view taken along the line IV-IV shown in Figure 1.

[0013] As shown in Figures 1 to 4, the light-emitting element 100 according to the first embodiment comprises a substrate 10, a semiconductor structure 20, an n electrode 30, a p electrode 40, an n pad electrode 50, and a p pad electrode 60.

[0014] (substrate) The substrate 10 is located at the bottom of the light-emitting element 100. The top and bottom surfaces of the substrate 10 are generally parallel to the XY plane. The substrate 10 has a first side 10a and a second side 10b. The first side 10a extends in the first direction (Y direction) when viewed from above. The second side 10b is parallel to the first side 10a when viewed from above. In the light-emitting element 100, the shape of the substrate 10 when viewed from above is rectangular. The substrate 10 has a first side 10a and a second side 10b that are parallel to each other when viewed from above, and a third side 10c and a fourth side 10d that connect the first side 10a and the second side 10b and are parallel to each other. The third side 10c and the fourth side 10d extend in the second direction (X direction) when viewed from above. If the shape of the substrate 10 when viewed from above is rectangular, the length of one side of the substrate 10 is, for example, 500 μm or more and 2000 μm or less. The shape of the substrate 10 when viewed from above may be any shape having a first side 10a and a second side 10b, and may be a polygon other than a rectangle, for example.

[0015] The substrate 10 includes, for example, sapphire. The thickness of the substrate 10 is, for example, 50 μm or more and 1000 μm or less, preferably 100 μm or more and 800 μm or less, and more preferably 300 μm or more and 800 μm or less.

[0016] (Semiconductor structure) The semiconductor structure 20 is placed on the substrate 10. The semiconductor structure 20 is in contact with the upper surface of the substrate 10. The semiconductor structure 20 has an n-type semiconductor layer 21, an active layer 22, and a p-type semiconductor layer 23. The n-type semiconductor layer 21 has a first region 21a and a second region 21b when viewed from above. The active layer 22 is placed on the second region 21b of the n-type semiconductor layer 21. The active layer 22 is in contact with the second region 21b. The p-type semiconductor layer 23 is placed on the active layer 22. The p-type semiconductor layer 23 is in contact with the active layer 22. The active layer 22 and the p-type semiconductor layer 23 are not placed on the first region 21a. The upper and lower surfaces of the n-type semiconductor layer 21, the active layer 22, and the p-type semiconductor layer 23 are planes that are approximately parallel to the XY plane, respectively.

[0017] The semiconductor structure 20 is made of a nitride semiconductor. In this specification, "nitride semiconductor" means, for example, In x Al y Ga 1-x-y The term "nitride semiconductor" includes semiconductors of all compositions obtained by varying the composition ratios x and y within the respective ranges in the chemical formula N(0≦x≦1,0≦y≦1,x+y≦1). Furthermore, the term "nitride semiconductor" also includes semiconductors that further include group V elements other than N (nitrogen) in the above chemical formula, and semiconductors that further include various elements added to control various physical properties such as conductivity. The n-type semiconductor layer 21 includes a semiconductor containing n-type impurities. Examples of n-type impurities in the n-type semiconductor layer 21 are silicon (Si) and phosphorus (P). The p-type semiconductor layer 23 includes a semiconductor layer containing p-type impurities. Examples of p-type impurities in the p-type semiconductor layer 23 are magnesium (Mg) and zinc (Zn). The semiconductor structure 20 emits, for example, violet or ultraviolet light. The peak wavelength of the light emitted by the semiconductor structure 20 is, for example, 250 nm to 410 nm. The thickness of the semiconductor structure 20 is, for example, 5 μm to 10 μm.

[0018] (n electrode) The n-electrode 30 is positioned on a first region 21a of the n-type semiconductor layer 21. The n-electrode 30 is in contact with the first region 21a. The upper and lower surfaces of the n-electrode 30 are planes that are approximately parallel to the XY plane, respectively. The n-electrode 30 has a first n-electrode region 30a, a second n-electrode region 30b, and a third n-electrode region 30c. The first n-electrode region 30a extends in a first direction (Y direction) when viewed from above. The first n-electrode region 30a overlaps with the n-pad electrode 50 when viewed from above. The second n-electrode region 30b extends from the first n-electrode region 30a in a second direction (X direction) when viewed from above. The second direction is perpendicular to the first direction. The second n-electrode region 30b overlaps with the n-pad electrode 50 when viewed from above. The third n electrode region 30c extends from the second n electrode region 30b in the second direction (X direction) when viewed from above. The third n electrode region 30c does not overlap with the n pad electrode 50 when viewed from above.

[0019] In the light-emitting element 100, the n electrode 30 has one first n electrode region 30a, five second n electrode regions 30b, and five third n electrode regions 30c. Each third n electrode region 30c extends in a second direction (X direction) from a different second n electrode region 30b. In the light-emitting element 100, the n electrode 30 has five second n electrode regions 30b. The number of second n electrode regions 30b is the same as the number of third n electrode regions 30c. In this embodiment, an example is shown where there are multiple second n electrode regions 30b and third n electrode regions 30c, but the number of second n electrode regions 30b and third n electrode regions 30c may be one.

[0020] The n electrode 30 includes, for example, one or more materials selected from the group consisting of titanium (Ti), nickel (Ni), aluminum silicon alloy (AlSi), tantalum (Ta), rhodium (Rh), and ruthenium (Ru). The thickness of the n electrode 30 is, for example, 0.1 μm or more and 2 μm or less.

[0021] (p electrode) The p electrode 40 is positioned on the p-type semiconductor layer 23. The p electrode 40 is in contact with the p-type semiconductor layer 23. The upper and lower surfaces of the p electrode 40 are planes that are approximately parallel to the XY plane, respectively. The p electrode 40 has a first p electrode region 40a, a second p electrode region 40b, and a third p electrode region 40c. The first p electrode region 40a extends in a first direction (Y direction) when viewed from above. The first p electrode region 40a overlaps with the p pad electrode 60 when viewed from above. The second p electrode region 40b extends from the first p electrode region 40a in a second direction (X direction) when viewed from above. The second p electrode region 40b overlaps with the p pad electrode 60 when viewed from above. The third p electrode region 40c extends from the second p electrode region 40b in a second direction (X direction) when viewed from above. The third p electrode region 40c does not overlap with the p pad electrode 60 when viewed from above.

[0022] In the light-emitting element 100, the p electrode 40 has one first p electrode region 40a, four second p electrode regions 40b, and four third p electrode regions 40c. Each third p electrode region 40c extends in a second direction (X direction) from a different second p electrode region 40b. The number of second p electrode regions 40b is the same as the number of third p electrode regions 40c. In this embodiment, an example is shown where there are multiple second p electrode regions 40b and third p electrode regions 40c, but the number of second p electrode regions 40b and third p electrode regions 40c may be one.

[0023] In the light-emitting element 100, the p electrode 40 further has two fourth p electrode regions 40d. The fourth p electrode regions 40d extend from the first p electrode region 40a in a second direction (X direction) when viewed from above. The fourth p electrode regions 40d do not overlap with the p pad electrode 60 when viewed from above. The four second p electrode regions 40b and the four third p electrode regions 40c are located between the two fourth p electrode regions 40d in a first direction (Y direction). The number of fourth p electrode regions 40d may be one. The fourth p electrode regions 40d may be omitted.

[0024] The second p electrode region 40b is aligned with the third n electrode region 30c in the first direction (Y direction). The second p electrode region 40b is located between two adjacent third n electrode regions 30c in the first direction (Y direction). The third n electrode region 30c is located between two adjacent second p electrode regions 40b in the first direction (Y direction). The third p electrode region 40c is aligned with the second n electrode region 30b in the first direction (Y direction). The third p electrode region 40c is located between two adjacent second n electrode regions 30b in the first direction (Y direction). The second n electrode region 30b is located between two adjacent third p electrode regions 40c in the first direction (Y direction). The first n electrode region 30a is aligned with the third p electrode region 40c in the second direction (X direction). The first p-electrode region 40a is aligned with the third n-electrode region 30c in the second direction (X direction).

[0025] The p electrode 40 includes, for example, one or more materials selected from the group consisting of rhodium (Rh), ruthenium (Ru), titanium (Ti), nickel (Ni), and gold (Au). The thickness of the p electrode 40 is, for example, 0.1 μm or more and 1 μm or less. The reflectance of the p electrode 40 at the peak wavelength of light emitted by the semiconductor structure 20 is higher than the reflectance of the n electrode 30 at the peak wavelength of light emitted by the semiconductor structure 20.

[0026] (n-pad electrodes) The n-pad electrode 50 is positioned on top of the n-electrode 30. The n-pad electrode 50 is in contact with the n-electrode 30. The top and bottom surfaces of the n-pad electrode 50 are planes that are approximately parallel to the XY plane. In a top view, the n-pad electrode 50 is positioned closer to the first side 10a than to the second side 10b. In other words, in a top view, the distance between the n-pad electrode 50 and the first side 10a is shorter than the distance between the n-pad electrode 50 and the second side 10b.

[0027] The n-pad electrode 50 has a first n-pad electrode region 50a and a second n-pad electrode region 50b. The first n-pad electrode region 50a extends in a first direction (Y direction) when viewed from above. The second n-pad electrode region 50b extends from the first n-pad electrode region 50a in a second direction (X direction) when viewed from above.

[0028] In the light-emitting element 100, the n-pad electrode 50 has one first n-pad electrode region 50a and five second n-pad electrode regions 50b. The first n-pad electrode region 30a overlaps with the first n-pad electrode region 50a when viewed from above. The second n-pad electrode region 30b overlaps with the second n-pad electrode region 50b when viewed from above. The number of second n-pad electrode regions 50b is the same as the number of second n-pad electrode regions 30b.

[0029] The n-pad electrode 50 includes, for example, one or more materials selected from the group consisting of Ti, platinum (Pt), Ni, and Au. The thickness of the n-pad electrode 50 is, for example, 0.3 μm or more and 1 μm or less.

[0030] (p-pad electrode) The p-pad electrode 60 is positioned on top of the p-electrode 40. The p-pad electrode 60 is in contact with the p-electrode 40. The top and bottom surfaces of the p-pad electrode 60 are planes that are approximately parallel to the XY plane. In a top view, the p-pad electrode 60 is positioned closer to the second side 10b than to the first side 10a. In other words, in a top view, the distance between the p-pad electrode 60 and the second side 10b is shorter than the distance between the p-pad electrode 60 and the first side 10a.

[0031] The p-pad electrode 60 has a first p-pad electrode region 60a and a second p-pad electrode region 60b. The first p-pad electrode region 60a extends in a first direction (Y direction) when viewed from above. The second p-pad electrode region 60b extends from the first p-pad electrode region 60a in a second direction (X direction) when viewed from above.

[0032] In the light-emitting element 100, the p-pad electrode 60 has one first p-pad electrode region 60a and four second p-pad electrode regions 60b. The first p-pad electrode region 40a overlaps with the first p-pad electrode region 60a when viewed from above. The second p-pad electrode region 40b overlaps with the second p-pad electrode region 60b when viewed from above. The number of second p-pad electrode regions 60b is the same as the number of second p-pad electrode regions 40b.

[0033] The p-pad electrode 60 includes, for example, one or more materials selected from the group consisting of Ti, Pt, Ni, and Au. The thickness of the p-pad electrode 60 is, for example, 0.3 μm or more and 1 μm or less.

[0034] (protective film) The light-emitting element 100 further comprises a protective film 70. The protective film 70 is optional. The protective film 70 is placed on the substrate 10, the semiconductor structure 20, the n electrode 30, and the p electrode 40. A portion of the n pad electrode 50 is placed on the protective film 70. A portion of the p pad electrode 60 is placed on the protective film 70. The protective film 70 is in contact with the substrate 10, the semiconductor structure 20, the n electrode 30, the p electrode 40, the n pad electrode 50, and the p pad electrode 60.

[0035] The protective film 70 includes, for example, one or more selected from the group consisting of silicon oxide, silicon nitride, and silicon oxynitride. The thickness of the protective film 70 is, for example, 0.5 μm or more and 2 μm or less.

[0036] The first region 21a of the n-type semiconductor layer 21 has a first portion 21a1, a second portion 21a2, a third portion 21a3, and a fourth portion 21a4. The first portion 21a1 is located between the first n-electrode region 30a and the third p-electrode region 40c in a top view. The second portion 21a2 is located between the second n-electrode region 30b and the third p-electrode region 40c in a top view. The third portion 21a3 is located between the first p-electrode region 40a and the third n-electrode region 30c in a top view. The fourth portion 21a4 is located between the second p-electrode region 40b and the third n-electrode region 30c in a top view.

[0037] In the light-emitting element 100, the first region 21a further comprises a fifth portion 21a5. In a top view, the fifth portion 21a5 is located between the third n electrode region 30c and the third p electrode region 40c.

[0038] In the light-emitting element 100, the first region 21a further comprises a sixth portion 21a6 and a seventh portion 21a7. The sixth portion 21a6 is located between the second n electrode region 30b and the fourth p electrode region 40d in a top view. The seventh portion 21a7 is located between the third n electrode region 30c and the fourth p electrode region 40d in a top view.

[0039] In the light-emitting element 100, the first region 21a further has an outer peripheral portion 21ax. The outer peripheral portion 21ax is located between the first n electrode region 30a and the first side 10a when viewed from above. The first region 21a does not necessarily have to have the outer peripheral portion 21ax.

[0040] In the light-emitting element 100, the first groove 25a is provided in the first portion 21a1 and the second portion 21a2. In the light-emitting element 100, the first groove 25a is not provided in the third portion 21a3. The first groove 25a is recessed downwards.

[0041] More specifically, in the light-emitting element 100, the first groove 25a is arranged in the first portion 21a1, the second portion 21a2, the fifth portion 21a5, the sixth portion 21a6, part of the seventh portion 21a7, and part of the outer peripheral portion 21ax. In the light-emitting element 100, the first groove 25a is not arranged in the third portion 21a3, the fourth portion 21a4, and part of the seventh portion 21a7.

[0042] As shown in Figure 3, in the light-emitting element 100, the depth D25a of the first groove 25a is smaller than the thickness T21a2 of the second portion 21a2. In other words, in the light-emitting element 100, the lower end of the first groove 25a does not reach the upper surface of the substrate 10. The depth D25a is, for example, 0.5 μm or more and 3 μm or less. The thickness T21a2 is, for example, 3 μm or more and 10 μm or less. Here, the thickness T21a2 of the second portion 21a2 is the maximum thickness of the second portion 21a2.

[0043] In the light-emitting element 100, the width W25a of the first groove 25a in the first direction (Y direction) is, for example, 3% to 25%, preferably 5% to 15%, of the width W21a2 of the second portion 21a2 in the first direction (Y direction). The width W25a is, for example, 1 μm to 20 μm, preferably 2 μm to 10 μm, and more preferably 2 μm to 5 μm. The width W21a2 is, for example, 10 μm to 100 μm.

[0044] As shown in Figure 1, in the light-emitting element 100, the width W30c of the third n electrode region 30c in the first direction (Y direction) is smaller than the width W40c of the third p electrode region 40c in the first direction (Y direction). The width W30c is, for example, 20 μm or more and 80 μm or less, preferably about 40 μm. The width W40c is, for example, 30 μm or more and 120 μm or less, preferably about 60 μm.

[0045] (First embodiment, first modified example) Figure 5 is a schematic plan view showing a light-emitting element according to a first modified example of the first embodiment. Figures 6 to 8 are schematic cross-sectional views showing a light-emitting element according to a first modified example of the first embodiment. Figure 6 is a cross-sectional view taken along the line VI-VI shown in Figure 5. Figure 7 is a cross-sectional view taken along the line VII-VII shown in Figure 5. Figure 8 is a cross-sectional view taken along the line VIII-VIII shown in Figure 5.

[0046] As shown in Figures 5 to 8, the light-emitting element 100A according to the first modified example of the first embodiment is substantially the same as the light-emitting element 100 according to the first embodiment, except that the cross-sectional shape of the first groove 25a is different.

[0047] In the light-emitting element 100A, the depth D25a of the first groove 25a is the same as the thickness T21a2 of the second portion 21a2. In other words, in the light-emitting element 100A, the lower end of the first groove 25a reaches the upper surface of the substrate 10.

[0048] (Second modified example of the first embodiment) Figure 9 is a schematic plan view showing a light-emitting element according to a second modified example of the first embodiment. As shown in Figure 9, the light-emitting element 100B according to the second modification of the first embodiment is substantially the same as the light-emitting element 100 according to the first embodiment, except that the arrangement of the first groove 25a is different.

[0049] In the light-emitting element 100B, the first groove 25a is arranged in the first portion 21a1, the second portion 21a2, the fourth portion 21a4, the fifth portion 21a5, the sixth portion 21a6, the seventh portion 21a7, and the outer peripheral portion 21ax. In the light-emitting element 100B, the first groove 25a is not arranged in the third portion 21a3.

[0050] (Third modified example of the first embodiment) Figure 10 is a schematic plan view showing a light-emitting element according to a third modified example of the first embodiment. As shown in Figure 10, the light-emitting element 100C according to the third modification of the first embodiment is substantially the same as the light-emitting element 100 according to the first embodiment, except that the arrangement of the first groove 25a is different.

[0051] In the light-emitting element 100C, the first groove 25a is provided in the first portion 21a1, the second portion 21a2, the sixth portion 21a6, and the outer peripheral portion 21ax. In the light-emitting element 100C, the first groove 25a is not provided in the third portion 21a3, the fourth portion 21a4, the fifth portion 21a5, and the seventh portion 21a7.

[0052] (Fourth modified example of the first embodiment) Figure 11 is a schematic plan view showing a light-emitting element according to a fourth modified example of the first embodiment. As shown in Figure 11, the light-emitting element 100D according to the fourth modification of the first embodiment is substantially the same as the light-emitting element 100 according to the first embodiment, except that the arrangement of the first groove 25a is different.

[0053] In the light-emitting element 100D, the first groove 25a is located in the first portion 21a1, the second portion 21a2, the fifth portion 21a5, the sixth portion 21a6, and part of the seventh portion 21a7. In the light-emitting element 100D, the first groove 25a is not located in the third portion 21a3, the fourth portion 21a4, part of the seventh portion 21a7, and the outer peripheral portion 21ax.

[0054] (Most modified example of the first embodiment) Figure 25 is a schematic cross-sectional view showing a light-emitting element according to a fifth modified example of the first embodiment. As shown in Figure 25, the light-emitting element 100E according to the fifth modification of the first embodiment is substantially the same as the light-emitting element 100 according to the first embodiment, except that the arrangement of the first groove 25a is different.

[0055] In the light-emitting element 100E, the distance D1 between the first groove 25a and the p electrode 40 is shorter than the distance D2 between the first groove 25a and the n electrode 30. Thus, in a cross-sectional view, it is preferable that the distance D1 between the first groove 25a and the p electrode 40 is shorter than the distance D2 between the first groove 25a and the n electrode 30. By positioning the first groove 25a closer to the active layer 22 than the n electrode 30, the light from the active layer 22 is less likely to be directed towards the n electrode 30 by the first groove 25a, thereby reducing light absorption by the n electrode 30 and improving output.

[0056] <Second Embodiment> Figure 12 is a schematic plan view showing a light-emitting element according to the second embodiment. Figures 13 to 15 are schematic cross-sectional views showing the light-emitting element according to the second embodiment. Figure 13 is a cross-sectional view taken along the line XIII-XIII shown in Figure 12. Figure 14 is a cross-sectional view taken along the line XIV-XIV shown in Figure 12. Figure 15 is a cross-sectional view taken along the XV-XV line shown in Figure 12.

[0057] As shown in Figures 12 to 15, the light-emitting element 200 according to the second embodiment is substantially the same as the light-emitting element 100 according to the first embodiment, except that a second groove 25b is arranged in addition to the first groove 25a.

[0058] In the light-emitting element 200, a first groove 25a is provided in the first portion 21a1 and the second portion 21a2. In the light-emitting element 200, a second groove 25b is provided in at least one of the third portion 21a3 and the fourth portion 21a4. The first groove 25a and the second groove 25b are each recessed downwards.

[0059] More specifically, in the light-emitting element 200, the first groove 25a is located in the first portion 21a1, the second portion 21a2, the fifth portion 21a5, the sixth portion 21a6, part of the seventh portion 21a7, and the outer peripheral portion 21ax. In the light-emitting element 200, the second groove 25b is located in the third portion 21a3, the fourth portion 21a4, and part of the seventh portion 21a7. In a top view, the first groove 25a and the second groove 25b are continuous.

[0060] In the light-emitting element 200, the depth D25b of the second groove 25b is smaller than the depth D25a of the first groove 25a. In the light-emitting element 200, the depth D25a of the first groove 25a is the same as the thickness T21a2 of the second portion 21a2. That is, in the light-emitting element 200, the lower end of the first groove 25a reaches the upper surface of the substrate 10. In the light-emitting element 200, the depth D25b of the second groove 25b is smaller than the thickness T21a2 of the second portion 21a2. That is, in the light-emitting element 200, the lower end of the second groove 25b does not reach the upper surface of the substrate 10. The depth D25a of the first groove 25a may be smaller than the thickness T21a2 of the second portion 21a2. That is, the lower end of the first groove 25a does not have to reach the upper surface of the substrate 10. The depth D25a is, for example, 3 μm or more and 10 μm or less. The depth D25b is, for example, between 0.5 μm and 3 μm. The thickness T21a2 is, for example, between 3 μm and 10 μm.

[0061] In the light-emitting element 200, the width W25b of the second groove 25b in the first direction (Y direction) is the same as the width W25a of the first groove 25a in the first direction (Y direction). The width W25a of the first groove 25a in the first direction (Y direction) is, for example, 3% to 25%, preferably 5% to 15%, of the width W21a2 of the second portion 21a2 in the first direction (Y direction). The width W25b of the second groove 25b in the first direction (Y direction) is, for example, 3% to 25%, preferably 5% to 15%, of the width W21a4 of the fourth portion 21a4 in the first direction (Y direction). The widths W25a and W25b are, for example, 1 μm to 20 μm, preferably 2 μm to 10 μm, and more preferably 2 μm to 5 μm. The widths W21a2 and W21a4 are, for example, 10 μm or more and 100 μm or less.

[0062] In the light-emitting element 200, the width W30c of the third n electrode region 30c in the first direction (Y direction) is smaller than the width W40c of the third p electrode region 40c in the first direction (Y direction). The width W30c is, for example, 20 μm or more and 80 μm or less, preferably about 40 μm. The width W40c is, for example, 30 μm or more and 120 μm or less, preferably about 60 μm.

[0063] (First modified example of the second embodiment) Figure 16 is a schematic plan view showing a light-emitting element according to the first modified example of the second embodiment. As shown in Figure 16, the light-emitting element 200A according to the first modified example of the second embodiment is substantially the same as the light-emitting element 200 according to the second embodiment, except that the arrangement of the first groove 25a and the second groove 25b is different.

[0064] In the light-emitting element 200A, the first groove 25a is arranged throughout the first portion 21a1, the second portion 21a2, the fourth portion 21a4, the fifth portion 21a5, the sixth portion 21a6, the seventh portion 21a7, and the outer peripheral portion 21ax. In the light-emitting element 200A, the second groove 25b is arranged in the third portion 21a3.

[0065] (Second modified example of the second embodiment) Figure 17 is a schematic plan view showing a light-emitting element according to a second modified example of the second embodiment. As shown in Figure 17, the light-emitting element 200B according to the second modified example of the second embodiment is substantially the same as the light-emitting element 200 according to the second embodiment, except that the arrangement of the first groove 25a and the second groove 25b is different.

[0066] In the light-emitting element 200B, the first groove 25a is located in the first portion 21a1, the second portion 21a2, the sixth portion 21a6, and the outer peripheral portion 21ax. In the light-emitting element 200B, the second groove 25b is located in the third portion 21a3, the fourth portion 21a4, the fifth portion 21a5, and the seventh portion 21a7.

[0067] (Third modified example of the second embodiment) Figure 18 is a schematic plan view showing a light-emitting element according to a third modified example of the second embodiment. As shown in Figure 18, the light-emitting element 200C according to the third modified example of the second embodiment is substantially the same as the light-emitting element 200 according to the second embodiment, except that the arrangement of the first groove 25a and the second groove 25b is different.

[0068] In the light-emitting element 200C, the first groove 25a is located in the first portion 21a1, the second portion 21a2, the fifth portion 21a5, the sixth portion 21a6, part of the seventh portion 21a7, and the outer peripheral portion 21ax. In the light-emitting element 200C, the second groove 25b is located in the fourth portion 21a4 and part of the seventh portion 21a7. In the light-emitting element 200C, neither the first groove 25a nor the second groove 25b is located in the third portion 21a3.

[0069] (Fourth modified example of the second embodiment) Figure 19 is a schematic plan view showing a light-emitting element according to a fourth modified example of the second embodiment. As shown in Figure 19, the light-emitting element 200D according to the fourth modification of the second embodiment is substantially the same as the light-emitting element 200 according to the second embodiment, except that the arrangement of the first groove 25a and the second groove 25b is different.

[0070] In the light-emitting element 200D, the first groove 25a is located in the first portion 21a1, the second portion 21a2, the sixth portion 21a6, and the outer peripheral portion 21ax. In the light-emitting element 200D, the second groove 25b is located in the fourth portion 21a4, the fifth portion 21a5, and the seventh portion 21a7. In the light-emitting element 200D, neither the first groove 25a nor the second groove 25b is located in the third portion 21a3.

[0071] (Fifth modified example of the second embodiment) Figure 20 is a schematic plan view showing a light-emitting element according to a fifth modified example of the second embodiment. As shown in Figure 20, the light-emitting element 200E according to the first modified example of the second embodiment is substantially the same as the light-emitting element 200 according to the second embodiment, except that the arrangement of the first groove 25a and the second groove 25b is different.

[0072] In the light-emitting element 200E, the first groove 25a is located in part of the first portion 21a1, the second portion 21a2, the fifth portion 21a5, the sixth portion 21a6, and the seventh portion 21a7. In the light-emitting element 200E, the second groove 25b is located in part of the third portion 21a3, the fourth portion 21a4, and the seventh portion 21a7. In the light-emitting element 200E, neither the first groove 25a nor the second groove 25b is located in the outer peripheral portion 21ax. However, in the light-emitting element 200E, the second groove 25b may be located in the outer peripheral portion 21ax.

[0073] <Third Embodiment> Figure 21 is a schematic plan view showing a light-emitting element according to the third embodiment. Figures 22 to 24 are schematic cross-sectional views showing a light-emitting element according to the third embodiment. Figure 22 is a cross-sectional view taken along the line XXII-XXII shown in Figure 21. Figure 23 is a cross-sectional view taken along the line XXIII-XXIII shown in Figure 21. Figure 24 is a cross-sectional view taken along the line XXIV-XXIV shown in Figure 21.

[0074] As shown in Figures 21 to 24, the light-emitting element 300 according to the third embodiment is substantially the same as the light-emitting element 100 according to the first embodiment, except that a second groove 25b is arranged in addition to the first groove 25a.

[0075] In the light-emitting element 300, a first groove 25a is provided in the first portion 21a1 and the second portion 21a2. In the light-emitting element 300, a second groove 25b is provided in at least one of the third portion 21a3 and the fourth portion 21a4. The first groove 25a and the second groove 25b are each recessed downwards.

[0076] More specifically, in the light-emitting element 300, the first groove 25a is located in the first portion 21a1, the second portion 21a2, the fifth portion 21a5, the sixth portion 21a6, part of the seventh portion 21a7, and the outer peripheral portion 21ax. In the light-emitting element 300, the second groove 25b is located in the third portion 21a3, the fourth portion 21a4, and part of the seventh portion 21a7. In the light-emitting element 300 according to the third embodiment, the first groove 25a and the second groove 25b may be located in the positions of the first to fifth modified examples of the second embodiment described above.

[0077] In the light-emitting element 300, the depth D25b of the second groove 25b is the same as the depth D25a of the first groove 25a. In the light-emitting element 300, the depths D25a of the first groove 25a and the second groove 25b are smaller than the thickness T21a2 of the second portion 21a2. In other words, in the light-emitting element 300, the lower ends of the first groove 25a and the second groove 25b do not reach the upper surface of the substrate 10. The depths D25a of the first groove 25a and the second groove 25b may be the same as the thickness T21a2 of the second portion 21a2. In other words, the lower ends of the first groove 25a and the second groove 25b may reach the upper surface of the substrate 10. The depths D25a and D25b are, for example, 0.5 μm or more and 3 μm or less. The thickness T21a2 is, for example, between 3 μm and 10 μm.

[0078] In the light-emitting element 300, the width W25b of the second groove 25b in the first direction (Y direction) is smaller than the width W25a of the first groove 25a in the first direction (Y direction). The width W25a of the first groove 25a in the first direction (Y direction) is, for example, 3% to 25%, preferably 5% to 15%, of the width W21a1 of the second portion 21a2 in the first direction (Y direction). The width W25b of the second groove 25b in the first direction (Y direction) is, for example, 3% to 25%, preferably 5% to 15%, of the width W21a4 of the fourth portion 21a4 in the first direction (Y direction). The widths W25a and W25b are, for example, 1 μm to 20 μm, preferably 2 μm to 10 μm, and more preferably 2 μm to 5 μm. The widths W21a2 and W21a4 are, for example, 10 μm or more and 100 μm or less.

[0079] In the light-emitting element 300, the width W30c of the third n electrode region 30c in the first direction (Y direction) is smaller than the width W40c of the third p electrode region 40c in the first direction (Y direction). The width W30c is, for example, 20 μm or more and 80 μm or less, preferably about 40 μm. The width W40c is, for example, 30 μm or more and 120 μm or less, preferably about 60 μm.

[0080] The effects and benefits of the light-emitting elements according to the first to third embodiments will be described below. In light-emitting elements, current concentration may occur around the n-pad electrodes, potentially reducing the reliability of the light-emitting element. One possible solution is to lengthen the current path around the n-pad electrodes by placing grooves in the semiconductor structure surrounding the n-pad electrodes (i.e., making it more difficult for current to flow). However, placing grooves to surround the entire n-electrode may increase the forward voltage.

[0081] In contrast, in the light-emitting element according to the first embodiment, the first groove 25a is arranged in the first portion 21a1 and the second portion 21a2, but the first groove 25a is not arranged in the third portion 21a3. This reduces current concentration around the n-pad electrode 50 while also reducing the increase in forward voltage. Furthermore, the first groove 25a makes it difficult for light from the active layer 22 to be directed towards the n-electrode 30, thereby reducing light absorption by the n-electrode 30 and improving output.

[0082] In the light-emitting element according to the second embodiment, the first groove 25a is provided in the first portion 21a1 and the second portion 21a2, and the second groove 25b, which is shallower than the first groove 25a, is provided in at least one of the third portion 21a3 and the fourth portion 21a4. This reduces current concentration around the n-pad electrode 50 while also reducing the increase in forward voltage. Furthermore, the first groove 25a makes it difficult for light from the active layer 22 to be directed toward the n-electrode 30, thereby reducing light absorption by the n-electrode 30 and improving output.

[0083] In the light-emitting element according to the third embodiment, the first groove 25a is provided in the first portion 21a1 and the second portion 21a2, and the second groove 25b, which is narrower than the first groove 25a, is provided in at least one of the third portion 21a3 and the fourth portion 21a4. This reduces current concentration around the n-pad electrode 50 while also reducing the increase in forward voltage. Furthermore, the first groove 25a makes it difficult for light from the active layer 22 to be directed toward the n-electrode 30, thereby reducing light absorption by the n-electrode 30 and improving output.

[0084] In the light-emitting element according to the first embodiment, by arranging the first groove 25a in the fourth portion 21a4, current concentration around the n-pad electrode 50 can be further reduced compared to the case where the first groove 25a is arranged in the fourth portion 21a4.

[0085] In the light-emitting element according to the first embodiment, the absence of the first groove 25a in the fourth portion 21a4 reduces the increase in forward voltage compared to the case where the first groove 25a is placed in the fourth portion 21a4.

[0086] In the light-emitting element according to the second and third embodiments, the second groove 25b is arranged in the fourth portion 21a4, and the first groove 25a and the second groove 25b are not arranged in the third portion 21a3, thereby reducing the increase in forward voltage.

[0087] In the light-emitting element according to the second and third embodiments, the second groove 25b is arranged in the third portion 21a3 and the first groove 25a is arranged in the fourth portion 21a4, which reduces the increase in forward voltage compared to the case where the first groove 25a is arranged in both the third portion 21a3 and the fourth portion 21a4.

[0088] In the light-emitting element according to the second and third embodiments, the arrangement of the second groove 25b in the third portion 21a3 and the fourth portion 21a4 reduces the increase in forward voltage compared to the case where the first groove 25a is arranged in the third portion 21a3 and the fourth portion 21a4. Furthermore, compared to the case where the first groove 25a and the second groove 25b are not arranged in the third portion 21a3 and the fourth portion 21a4, light absorption by the n electrode 30 is reduced and the output can be improved.

[0089] In the light-emitting element according to the first to third embodiments, the arrangement of the first groove 25a in the fifth portion 21a5 further reduces current concentration around the n-pad electrode 50. Furthermore, compared to the case where the first groove 25a and the second groove 25b are not arranged in the fifth portion 21a5, light absorption by the n-electrode 30 is reduced and the output can be improved.

[0090] In the light-emitting element according to the first to third embodiments, the absence of the first groove 25a in the fifth portion 21a5 reduces the increase in forward voltage compared to the case where the first groove 25a is arranged in the fifth portion 21a5.

[0091] In the light-emitting element according to the second and third embodiments, the arrangement of the second groove 25b in the fifth portion 21a5 reduces the increase in forward voltage compared to the case where the first groove 25a is arranged in the fifth portion 21a5. Furthermore, compared to the case where neither the first groove 25a nor the second groove 25b is arranged in the fifth portion 21a5, light absorption by the n electrode 30 is reduced, and the output can be improved.

[0092] In the light-emitting element according to the first to third embodiments, the arrangement of the first groove 25a in the outer peripheral portion 21ax reduces light absorption by the n electrode 30 and improves output compared to the case where the first groove 25a is not arranged in the outer peripheral portion 21ax.

[0093] In the light-emitting element according to the first to third embodiments, since the first groove 25a is not arranged in the outer peripheral portion 21ax, more of the n-type semiconductor layer 21 can be left compared to the case where the first groove 25a is arranged in the outer peripheral portion 21ax, thus reducing the increase in forward voltage.

[0094] In the light-emitting element according to the first to third embodiments, the width W25a of the first groove 25a is 3% to 25% of the width W21a2 of the second portion 21a2, thereby reducing the amount of n-type semiconductor layer 21 remaining and lowering the forward voltage, as well as reducing light absorption by the n electrode 30 and improving the output.

[0095] In the light-emitting elements according to the first to third embodiments, since the depth D25a of the first groove 25a is smaller than the thickness T21a2 of the second portion 21a2, more of the n-type semiconductor layer 21 can be left compared to the case where the depth D25a is the same as the thickness T21a2, thus reducing the increase in forward voltage.

[0096] In the light-emitting element according to the first to third embodiments, the depth D25a of the first groove 25a is the same as the thickness T21a2 of the second portion 21a2, thereby reducing light absorption by the n electrode 30 and improving output.

[0097] In the light-emitting element according to the first to third embodiments, the width W30c of the thirdn electrode region 30c is smaller than the width W40c of the thirdp electrode region 40c, thereby reducing light absorption by the thirdn electrode region 30c and improving output.

[0098] The grooves may consist only of linear grooves, only of dashed lines, or a mixture of linear and dashed lines. Furthermore, grooves may be arranged along two or more lines.

[0099] <Example 1 and Reference Examples 1-3> Light-emitting elements of Example 1 and Reference Examples 1-3 were fabricated from a single wafer. For Example 1 and Reference Examples 1-3, the forward voltage Vf and output voltage Po were measured when a current of 350 mA was applied to the light-emitting elements. Furthermore, the brightness distribution of the light-emitting elements in Example 1 and Reference Examples 1-3 was observed from above to determine whether there were any areas of current concentration around the n-pad electrodes. The results are shown in Table 1.

[0100] (Example 1) The light-emitting element of Example 1 corresponds to the light-emitting element 100B according to the second modified example of the first embodiment shown in Figure 9. In the light-emitting element of Example 1, the first groove 25a is arranged in the first portion 21a1, the second portion 21a2, the fourth portion 21a4, the fifth portion 21a5, the sixth portion 21a6, the seventh portion 21a7, and the outer peripheral portion 21ax shown in Figure 9, but the first groove 25a is not arranged in the third portion 21a3. In other words, in the light-emitting element of Example 1, the first groove 25a is arranged in the part of the periphery of the n electrode 30 other than the third portion 21a3.

[0101] (Reference example 1) In the light-emitting element of Reference Example 1, the first groove 25a is not located in any of the first part 21a1, second part 21a2, third part 21a3, fourth part 21a4, fifth part 21a5, sixth part 21a6, seventh part 21a7, or outer peripheral part 21ax shown in Figure 9. In other words, in the light-emitting element of Reference Example 1, the first groove 25a is not located around the n electrode 30.

[0102] (Reference example 2) In the light-emitting element of Reference Example 2, the first groove 25a is provided in all of the first part 21a1, second part 21a2, third part 21a3, fourth part 21a4, fifth part 21a5, sixth part 21a6, seventh part 21a7, and outer peripheral part 21ax shown in Figure 9. In other words, in the light-emitting element of Reference Example 2, the first groove 25a is provided in all parts around the n electrode 30.

[0103] (Reference example 3) In the light-emitting element of Reference Example 3, the first groove 25a is located in the second portion 21a2, the third portion 21a3, the fourth portion 21a4, the fifth portion 21a5, the sixth portion 21a6, the seventh portion 21a7, and the outer peripheral portion 21ax, as shown in Figure 9, but the first groove 25a is not located in the first portion 21a1. In other words, in the light-emitting element of Reference Example 3, the first groove 25a is located in the area around the n electrode 30, excluding the first portion 21a1.

[0104] In Example 1 and Reference Examples 1-3, the shape of the substrate 10 when viewed from above is a square with sides of 1000 μm. Also, in Example 1 and Reference Examples 2 and 3, the width W25a of the first groove 25a is 9 μm, and the depth D25a of the first groove 25a is 2 μm. Also, in Example 1 and Reference Examples 1-3, the width W21a2 of the second portion 21a2 is approximately 22 μm, and the thickness T21a2 of the second portion 21a2 is approximately 6 μm.

[0105] [Table 1]

[0106] As shown in Table 1, in the light-emitting element of Reference Example 1, the first groove 25a is not positioned around the n electrode 30, so although the forward voltage Vf is low, the output Po is low and there are areas where current concentration occurs. In contrast, in the light-emitting element of Reference Example 2, the first groove 25a is positioned around the entire area of ​​the n electrode 30, so although the output Po is high and there are no areas where current concentration occurs, the forward voltage Vf is high. In the light-emitting element of Reference Example 3, the first groove 25a is positioned around the n electrode 30 in areas other than the first portion 21a1, so although the forward voltage Vf is not high, the output Po is also not high, and there are areas where current concentration occurs around the n pad electrode. In contrast, in the light-emitting element of Example 1, the first groove 25a is positioned around the n electrode 30 in areas other than the third portion 21a3, so the forward voltage Vf is not high, the output Po is high, and there are no areas where current concentration occurs around the n pad electrode. In other words, the light-emitting element of Example 1 is considered to be more reliable than the light-emitting elements of Reference Examples 1 to 3.

[0107] <Examples 2-7 and Reference Example 4> Light-emitting elements for Examples 2-7 and Reference Example 4 were fabricated from a single wafer different from the wafer used to produce Examples 1 and Reference Examples 1-3. The forward voltage Vf and output Po were measured for the light-emitting elements of Examples 2-7 and Reference Example 4 when a current of 350 mA was applied to the light-emitting elements. The results are shown in Table 2. Examples 2-7 show the changes in forward voltage Vf and output Po when the ratio of the width of the first groove 25a to the width of the second portion 21a2 W21a2 is changed.

[0108] (Examples 2-7) The light-emitting elements of Examples 2 to 7 correspond to the light-emitting element 100B according to the second modified example of the first embodiment shown in Figure 9. In the light-emitting elements of Examples 2 to 7, the first groove 25a is arranged in the first portion 21a1, the second portion 21a2, the fourth portion 21a4, the fifth portion 21a5, the sixth portion 21a6, the seventh portion 21a7, and the outer peripheral portion 21ax shown in Figure 9, but the first groove 25a is not arranged in the third portion 21a3. In other words, in the light-emitting elements of Examples 2 to 7, the first groove 25a is arranged in the part of the periphery of the n electrode 30 other than the third portion 21a3.

[0109] (Reference example 4) In the light-emitting element of Reference Example 4, the first groove 25a is not located in any of the first part 21a1, second part 21a2, third part 21a3, fourth part 21a4, fifth part 21a5, sixth part 21a6, seventh part 21a7, or outer peripheral part 21ax shown in Figure 9. In other words, in the light-emitting element of Reference Example 4, the first groove 25a is not located around the n electrode 30.

[0110] In Examples 2-7 and Reference Example 4, the top view of the substrate 10 shows a square shape with sides of 1000 μm. Also, in Examples 2-7, as shown in Table 2, the width W25a of the first groove 25a is 1.5-9.5 μm, and the depth D25a of the first groove 25a is 2 μm. Also, in Examples 2-7 and Reference Example 4, the width W21a2 of the second portion 21a2 is approximately 22 μm, and the thickness T21a2 of the second portion 21a2 is approximately 6 μm. Also, in Examples 2-7, as shown in Table 2, the ratio of the width 25a of the first groove 25a to the width W21a2 of the second portion 21a2 is 6.82-43.18%.

[0111] [Table 2]

[0112] As shown in Table 2, in the light-emitting element of Reference Example 4, the first groove 25a is not arranged around the n electrode 30, so although the forward voltage Vf was low, the output Po was also low. In contrast, in the light-emitting elements of Examples 2 to 7, the first groove 25a is arranged around the n electrode 30 in parts other than the third part 21a3, so the forward voltage Vf was not high, but the output Po was high. In other words, the light-emitting elements of Examples 2 to 7 are considered to be more reliable than the light-emitting element of Reference Example 4. Furthermore, it was suggested that in the light-emitting elements of Examples 2 to 7, the forward voltage Vf increases as the ratio of the width 25a of the first groove 25a to the width W21a2 of the second part 21a2 increases. It was also suggested that if the width W25a of the first groove 25a is between 5% and 25% of the width W21a2 of the second part 21a2, the output Po can be increased while reducing the increase in the forward voltage Vf.

[0113] From the above, it is suggested that, according to the embodiment, it is possible to reduce current concentration around the n-pad electrode while also reducing the increase in forward voltage.

[0114] The embodiment may include the following configurations.

[0115] (Composition 1) A substrate having a first side extending in a first direction in a top view, and a second side parallel to the first side, A semiconductor structure comprising: an n-type semiconductor layer disposed on the substrate and having a first region and a second region when viewed from above; an active layer disposed on the second region; and a p-type semiconductor layer disposed on the active layer. An n electrode placed on the first region, A p electrode disposed on the aforementioned p-type semiconductor layer, An n-pad electrode is placed on the n-electrode and positioned closer to the first side than the second side when viewed from above, A p-pad electrode is placed on the p-electrode and positioned closer to the second side than the first side when viewed from above, Equipped with, The n electrode is, In a top view, a first n electrode region extending in the first direction and overlapping with the n pad electrode, In a top view, a second n-electrode region extends from the first n-electrode region in a second direction perpendicular to the first direction and overlaps with the n-pad electrode, In a top view, a third n electrode region extends from the second n electrode region in the second direction and does not overlap with the n pad electrode, It has, The p electrode is, In a top view, a first p-electrode region extending in the first direction and overlapping with the p-pad electrode, In a top view, a second p electrode region extends from the first p electrode region in the second direction and overlaps with the p pad electrode, In a top view, a third p electrode region extends from the second p electrode region in the second direction and does not overlap with the p pad electrode, It has, The 2p electrode region is aligned with the 3n electrode region in the first direction, The 3p electrode region is aligned with the 2n electrode region in the first direction, The first region is, A first portion located between the first n electrode region and the third p electrode region in a top view, A second portion located between the 2n electrode region and the 3p electrode region in a top view, A third portion located between the first p electrode region and the third n electrode region in a top view, A fourth portion located between the 2p electrode region and the 3n electrode region in a top view, It has, The first and second portions are provided with a first groove that is recessed downwards. The third portion is a light-emitting element in which the first groove is not provided. (Configuration 2) A substrate having a first side extending in a first direction in a top view, and a second side parallel to the first side, A semiconductor structure comprising: an n-type semiconductor layer disposed on the substrate and having a first region and a second region when viewed from above; an active layer disposed on the second region; and a p-type semiconductor layer disposed on the active layer. An n electrode placed on the first region, A p electrode disposed on the aforementioned p-type semiconductor layer, An n-pad electrode is placed on the n-electrode and positioned closer to the first side than the second side when viewed from above, A p-pad electrode is placed on the p-electrode and positioned closer to the second side than the first side when viewed from above, Equipped with, The n electrode is, In a top view, a first n electrode region extending in the first direction and overlapping with the n pad electrode, In a top view, a second n-electrode region extends from the first n-electrode region in a second direction perpendicular to the first direction and overlaps with the n-pad electrode, In a top view, a third n electrode region extends from the second n electrode region in the second direction and does not overlap with the n pad electrode, It has, The p electrode is, In a top view, a first p-electrode region extending in the first direction and overlapping with the p-pad electrode, In a top view, a second p electrode region extends from the first p electrode region in the second direction and overlaps with the p pad electrode, In a top view, a third p electrode region extends from the second p electrode region in the second direction and does not overlap with the p pad electrode, It has, The 2p electrode region is aligned with the 3n electrode region in the first direction, The 3p electrode region is aligned with the 2n electrode region in the first direction, The first region is, A first portion located between the first n electrode region and the third p electrode region in a top view, A second portion located between the 2n electrode region and the 3p electrode region in a top view, A third portion located between the first p electrode region and the third n electrode region in a top view, A fourth portion located between the 2p electrode region and the 3n electrode region in a top view, It has, The first and second portions are provided with a first groove that is recessed downwards. At least one of the third and fourth portions is provided with a second groove that is recessed downwards, A light-emitting element in which the depth of the second groove is smaller than the depth of the first groove. (Composition 3) A substrate having a first side extending in a first direction in a top view, and a second side parallel to the first side, A semiconductor structure comprising: an n-type semiconductor layer disposed on the substrate and having a first region and a second region when viewed from above; an active layer disposed on the second region; and a p-type semiconductor layer disposed on the active layer. An n electrode placed on the first region, A p electrode disposed on the aforementioned p-type semiconductor layer, An n-pad electrode is placed on the n-electrode and positioned closer to the first side than the second side when viewed from above, A p-pad electrode is placed on the p-electrode and positioned closer to the second side than the first side when viewed from above, Equipped with, The n electrode is, In a top view, a first n electrode region extending in the first direction and overlapping with the n pad electrode, In a top view, a second n-electrode region extends from the first n-electrode region in a second direction perpendicular to the first direction and overlaps with the n-pad electrode, In a top view, a third n electrode region extends from the second n electrode region in the second direction and does not overlap with the n pad electrode, It has, The p electrode is, In a top view, a first p-electrode region extending in the first direction and overlapping with the p-pad electrode, In a top view, a second p electrode region extends from the first p electrode region in the second direction and overlaps with the p pad electrode, In a top view, a third p electrode region extends from the second p electrode region in the second direction and does not overlap with the p pad electrode, It has, The 2p electrode region is aligned with the 3n electrode region in the first direction, The 3p electrode region is aligned with the 2n electrode region in the first direction, The first region is, A first portion located between the first n electrode region and the third p electrode region in a top view, A second portion located between the 2n electrode region and the 3p electrode region in a top view, A third portion located between the first p electrode region and the third n electrode region in a top view, A fourth portion located between the 2p electrode region and the 3n electrode region in a top view, It has, The first and second portions are provided with a first groove that is recessed downwards. At least one of the third and fourth portions is provided with a second groove that is recessed downwards, A light-emitting element wherein the width of the second groove in the first direction is smaller than the width of the first groove in the first direction. (Composition 4) The light-emitting element according to configuration 1, wherein the first groove is disposed in the fourth portion. (Composition 5) The light-emitting element according to configuration 1, wherein the fourth portion does not have the first groove portion. (Composition 6) The fourth portion is provided with the second groove, The light-emitting element according to configuration 2 or 3, wherein the third portion does not have the first groove and the second groove. (Composition 7) The third portion is provided with the second groove, The light-emitting element according to configuration 2 or 3, wherein the first groove is disposed in the fourth portion. (Composition 8) The light-emitting element according to configuration 2 or 3, wherein the second groove is disposed in the third and fourth portions. (Composition 9) The first region further has a fifth portion located between the third n electrode region and the third p electrode region in a top view, The light-emitting element according to any one of configurations 1 to 8, wherein the fifth portion is provided with the first groove. (Composition 10) The first region further has a fifth portion located between the third n electrode region and the third p electrode region in a top view, The light-emitting element according to any one of configurations 1 to 8, wherein the fifth portion does not have the first groove portion. (Composition 11) The first region further has a fifth portion located between the third n electrode region and the third p electrode region in a top view, The light-emitting element according to any one of configurations 2, 3, 6 to 8, wherein the second groove is located in the fifth portion. (Composition 12) The first region further has an outer peripheral portion located between the first n electrode region and the first edge in a top view, The light-emitting element according to any one of configurations 1 to 11, wherein the first groove is arranged on the outer peripheral portion. (Composition 13) The first region further has an outer peripheral portion located between the first n electrode region and the first edge in a top view, The light-emitting element according to any one of configurations 1 to 11, wherein the first groove is not disposed on the outer peripheral portion. (Composition 14) A light-emitting element according to any one of configurations 1 to 13, wherein the width of the first groove in the first direction is 3% or more and 25% or less of the width of the second portion in the first direction. (Composition 15) A light-emitting element according to any one of configurations 1 to 14, wherein the depth of the first groove is smaller than the thickness of the second portion. (Composition 16) A light-emitting element according to any one of configurations 1 to 14, wherein the depth of the first groove is the same as the thickness of the second portion. (Composition 17) A light-emitting element according to any one of configurations 1 to 16, wherein the width of the third n electrode region in the first direction is smaller than the width of the third p electrode region in the first direction. (Composition 18) A light-emitting element according to any one of configurations 1 to 17, wherein the distance between the first groove and the p electrode is shorter than the distance between the first groove and the n electrode.

[0116] As described above, according to the embodiment, it is possible to provide a light-emitting element that can reduce current concentration around the n-pad electrode while also reducing the increase in forward voltage.

[0117] The embodiments described above are examples of the present invention, and the present invention is not limited to these embodiments. For example, the present invention is also included in the embodiments described above in which some components or processes are added, deleted, or modified. Furthermore, the embodiments described above can be implemented in combination with each other. [Explanation of Symbols]

[0118] 10: Circuit board 10a: First side 10b: Second side 10c: Third side 10d: Fourth side 20: Semiconductor Structures 21: n-type semiconductor layer 21a: First area 21a1: Part 1 21a2:Second part 21a3: 3rd part 21a4: 4th part 21a5: 5th part 21a6: Part 6 21a7: Part 7 21ax: Outer part 21b:Second area 22:Active layer 23: p-type semiconductor layer 25a: First groove 25b: Second groove 30:n electrode 30a: 1st n electrode area 30b: 2nd n electrode area 30c: 3rd n electrode area 40:p electrode 40a: 1st p electrode area 40b: 2nd p electrode area 40c: 3rd p electrode area 40d: 4th p electrode area 50:n pad electrode 50a: First n-pad electrode region 50b: Second n-pad electrode region 60: p-pad electrode 60a: First p pad electrode area 60b: Second p pad electrode area 70:Protective film 100, 100A~100E, 200, 200A~200E, 300: Light-emitting element

Claims

1. A substrate having a first side extending in a first direction in a top view, and a second side parallel to the first side, A semiconductor structure comprising: an n-type semiconductor layer disposed on the substrate and having a first region and a second region in a top view; an active layer disposed on the second region; and a p-type semiconductor layer disposed on the active layer. n electrodes placed on the first region, A p electrode disposed on the p-type semiconductor layer, An n-pad electrode is placed on the n-electrode and positioned closer to the first side than the second side when viewed from above, A p-pad electrode is placed on the p-electrode and positioned closer to the second side than the first side when viewed from above, Equipped with, The n electrode is, In a top view, a first n electrode region extending in the first direction and overlapping with the n pad electrode, In a top view, a second n-electrode region extends from the first n-electrode region in a second direction perpendicular to the first direction and overlaps with the n-pad electrode, In a top view, a third n electrode region extends from the second n electrode region in the second direction and does not overlap with the n pad electrode, It has, The p electrode is, In a top view, a first p-electrode region extending in the first direction and overlapping with the p-pad electrode, In a top view, a second p-electrode region extends from the first p-electrode region in the second direction and overlaps with the p-pad electrode, In a top view, a third p electrode region extends from the second p electrode region in the second direction and does not overlap with the p pad electrode, It has, The 2p electrode region is aligned with the 3n electrode region in the first direction, The 3p electrode region is aligned with the 2n electrode region in the first direction, The first region is, A first portion located between the first n electrode region and the third p electrode region in a top view, A second portion located between the 2n electrode region and the 3p electrode region in a top view, A third portion located between the first p electrode region and the third n electrode region in a top view, A fourth portion located between the 2p electrode region and the 3n electrode region in a top view, It has, The first and second portions are provided with a first groove that is recessed downwards. The third portion is a light-emitting element in which the first groove is not provided.

2. A substrate having a first side extending in a first direction in a top view, and a second side parallel to the first side, A semiconductor structure comprising: an n-type semiconductor layer disposed on the substrate and having a first region and a second region in a top view; an active layer disposed on the second region; and a p-type semiconductor layer disposed on the active layer. n electrodes placed on the first region, A p electrode disposed on the p-type semiconductor layer, An n-pad electrode is placed on the n-electrode and positioned closer to the first side than the second side when viewed from above, A p-pad electrode is placed on the p-electrode and positioned closer to the second side than the first side when viewed from above, Equipped with, The n electrode is, In a top view, a first n electrode region extending in the first direction and overlapping with the n pad electrode, In a top view, a second n-electrode region extends from the first n-electrode region in a second direction perpendicular to the first direction and overlaps with the n-pad electrode, In a top view, a third n electrode region extends from the second n electrode region in the second direction and does not overlap with the n pad electrode, It has, The p electrode is, In a top view, a first p-electrode region extending in the first direction and overlapping with the p-pad electrode, In a top view, a second p-electrode region extends from the first p-electrode region in the second direction and overlaps with the p-pad electrode, In a top view, a third p electrode region extends from the second p electrode region in the second direction and does not overlap with the p pad electrode, It has, The 2p electrode region is aligned with the 3n electrode region in the first direction, The 3p electrode region is aligned with the 2n electrode region in the first direction, The first region is, A first portion located between the first n electrode region and the third p electrode region in a top view, A second portion located between the 2n electrode region and the 3p electrode region in a top view, A third portion located between the first p electrode region and the third n electrode region in a top view, A fourth portion located between the 2p electrode region and the 3n electrode region in a top view, It has, The first and second portions are provided with a first groove that is recessed downwards. At least one of the third and fourth portions is provided with a second groove that is recessed downwards. A light-emitting element in which the depth of the second groove is smaller than the depth of the first groove.

3. A substrate having a first side extending in a first direction in a top view, and a second side parallel to the first side, A semiconductor structure comprising: an n-type semiconductor layer disposed on the substrate and having a first region and a second region in a top view; an active layer disposed on the second region; and a p-type semiconductor layer disposed on the active layer. n electrodes placed on the first region, A p electrode disposed on the p-type semiconductor layer, An n-pad electrode is placed on the n-electrode and positioned closer to the first side than the second side when viewed from above, A p-pad electrode is placed on the p-electrode and positioned closer to the second side than the first side when viewed from above, Equipped with, The n electrode is, In a top view, a first n electrode region extending in the first direction and overlapping with the n pad electrode, In a top view, a second n-electrode region extends from the first n-electrode region in a second direction perpendicular to the first direction and overlaps with the n-pad electrode, In a top view, a third n electrode region extends from the second n electrode region in the second direction and does not overlap with the n pad electrode, It has, The p electrode is, In a top view, a first p-electrode region extending in the first direction and overlapping with the p-pad electrode, In a top view, a second p-electrode region extends from the first p-electrode region in the second direction and overlaps with the p-pad electrode, In a top view, a third p electrode region extends from the second p electrode region in the second direction and does not overlap with the p pad electrode, It has, The 2p electrode region is aligned with the 3n electrode region in the first direction, The 3p electrode region is aligned with the 2n electrode region in the first direction, The first region is, A first portion located between the first n electrode region and the third p electrode region in a top view, A second portion located between the 2n electrode region and the 3p electrode region in a top view, A third portion located between the first p electrode region and the third n electrode region in a top view, A fourth portion located between the 2p electrode region and the 3n electrode region in a top view, It has, The first and second portions are provided with a first groove that is recessed downwards. At least one of the third and fourth portions is provided with a second groove that is recessed downwards. A light-emitting element wherein the width of the second groove in the first direction is smaller than the width of the first groove in the first direction.

4. The light-emitting element according to claim 1, wherein the first groove is disposed in the fourth portion.

5. The light-emitting element according to claim 1, wherein the fourth portion does not have the first groove portion.

6. The second groove is located in the fourth portion. The light-emitting element according to claim 2 or 3, wherein the third portion does not have the first groove and the second groove.

7. The third portion is provided with the second groove, The light-emitting element according to claim 2 or 3, wherein the first groove is disposed in the fourth portion.

8. The light-emitting element according to claim 2 or 3, wherein the second groove is disposed in the third and fourth portions.

9. The first region further has a fifth portion located between the third n electrode region and the third p electrode region in a top view, The light-emitting element according to any one of claims 1 to 3, wherein the first groove is disposed in the fifth portion.

10. The first region further has a fifth portion located between the third n electrode region and the third p electrode region in a top view, The light-emitting element according to any one of claims 1 to 3, wherein the fifth portion does not have the first groove portion.

11. The first region further has a fifth portion located between the third n electrode region and the third p electrode region in a top view, The light-emitting element according to claim 2 or 3, wherein the second groove is disposed in the fifth portion.

12. The first region further has an outer peripheral portion located between the first n electrode region and the first edge in a top view, The light-emitting element according to any one of claims 1 to 3, wherein the first groove is arranged on the outer peripheral portion.

13. The first region further has an outer peripheral portion located between the first n electrode region and the first edge in a top view, The light-emitting element according to any one of claims 1 to 3, wherein the first groove is not disposed on the outer peripheral portion.

14. The light-emitting element according to any one of claims 1 to 3, wherein the width of the first groove in the first direction is 3% or more and 25% or less of the width of the second portion in the first direction.

15. The light-emitting element according to any one of claims 1 to 3, wherein the depth of the first groove is smaller than the thickness of the second portion.

16. The light-emitting element according to any one of claims 1 to 3, wherein the depth of the first groove is the same as the thickness of the second portion.

17. The light-emitting element according to any one of claims 1 to 3, wherein the width of the third n electrode region in the first direction is smaller than the width of the third p electrode region in the first direction.

18. The light-emitting element according to any one of claims 1 to 3, wherein the distance between the first groove and the p electrode is shorter than the distance between the first groove and the n electrode.

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