Light emitting element and method for manufacturing light emitting element

Abstract

Provided is a light-emitting element and a method for manufacturing a light-emitting element, which can improve light extraction efficiency. A first-conductivity-type semiconductor layer is a nitride semiconductor layer containing Al and Ga, and has a first layer and a second layer. The Al composition ratio of the first layer is lower than that of the second layer. The first-conductivity-type semiconductor layer has a first region in which a second-conductivity-type semiconductor layer and an active layer are stacked, and a second region in which the second-conductivity-type semiconductor layer and the active layer are exposed and connected to a first conductive member. The thickness of the first layer provided in the first region is thinner than that of the first layer provided in the second region, or the first layer is not provided in the first region.

Description

Technical Field

[0001] This invention relates to light-emitting elements and methods for manufacturing light-emitting elements. Background Technology

[0002] Patent Document 1 discloses a technique for improving light extraction efficiency by partially thinning the thickness of a semiconductor layer disposed on the light extraction surface side of the active layer in a semiconductor stack of a light-emitting element.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2013-084878 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] One embodiment of the present invention aims to provide a light-emitting element that can improve light extraction efficiency and a method for manufacturing the light-emitting element.

[0008] Technical solutions for solving technical problems

[0009] According to one aspect of the present invention, a light-emitting element comprises: a semiconductor stack having a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer; a first conductive member electrically connected to the first conductive semiconductor layer; and a second conductive member electrically connected to the second conductive semiconductor layer. The first conductive semiconductor layer is a nitride semiconductor layer comprising Al and Ga, having a first layer and a second layer, wherein the Al content ratio of the first layer is lower than that of the second layer. The first conductive semiconductor layer has a first region where the second conductive semiconductor layer and the active layer are stacked, and a second region exposed from the second conductive semiconductor layer and the active layer and connected to the first conductive member. The thickness of the first layer disposed in the first region is thinner than the thickness of the first layer disposed in the second region, or the first layer is not disposed in the first region.

[0010] According to one aspect of the present invention, a method for manufacturing a light-emitting element includes: forming a semiconductor layer stack on a substrate comprising a first conductive semiconductor layer, an active layer disposed on the first conductive semiconductor layer, and a second conductive semiconductor layer disposed on the active layer, wherein the first conductive semiconductor layer is a nitride semiconductor layer comprising Al and Ga, having a first layer disposed on the substrate and a second layer disposed on the first layer, the Al content ratio of the first layer being lower than the Al content ratio of the second layer; removing a portion of the second conductive semiconductor layer and a portion of the active layer, exposing a portion of the first conductive semiconductor layer from the second conductive semiconductor layer and the active layer, wherein... The steps include: forming a first region remaining without removing the second conductive semiconductor layer and the active layer, and a second region comprising a portion of the first conductive semiconductor layer exposed from the second conductive semiconductor layer and the active layer; removing the substrate after forming the first region and the second region to expose the surface of the first layer of the first conductive semiconductor layer; and removing at least a portion of the first layer disposed in the first region after exposing the surface of the first layer, leaving a first layer thicker than the first layer disposed in the first region remaining in the second region, or exposing the second layer disposed in the first region from the first layer.

[0011] The effects of the invention

[0012] According to one embodiment of the present invention, a light-emitting element capable of improving light extraction efficiency and a method for manufacturing the light-emitting element can be provided. Attached Figure Description

[0013] Figure 1 This is a schematic top view showing a portion of the structure of the light-emitting element according to the first embodiment of the present invention.

[0014] Figure 2 yes Figure 1 A schematic cross-sectional view of line II-II.

[0015] Figure 3 This is an enlarged schematic cross-sectional view of a portion of the semiconductor stack in the light-emitting element according to the first embodiment of the present invention.

[0016] Figure 4 This is a schematic cross-sectional view illustrating one step of the manufacturing method of the light-emitting element according to the first embodiment of the present invention.

[0017] Figure 5 This is a schematic cross-sectional view illustrating one step of the manufacturing method of the light-emitting element according to the first embodiment of the present invention.

[0018] Figure 6 This is a schematic cross-sectional view illustrating one step of the manufacturing method of the light-emitting element according to the first embodiment of the present invention.

[0019] Figure 7 This is a schematic cross-sectional view illustrating one step of the manufacturing method of the light-emitting element according to the first embodiment of the present invention.

[0020] Figure 8 This is a schematic cross-sectional view illustrating one step of the manufacturing method of the light-emitting element according to the first embodiment of the present invention.

[0021] Figure 9 This is a schematic cross-sectional view illustrating one step of the manufacturing method of the light-emitting element according to the first embodiment of the present invention.

[0022] Figure 10 This is a schematic cross-sectional view illustrating one step of the manufacturing method of the light-emitting element according to the first embodiment of the present invention.

[0023] Figure 11 This is a schematic cross-sectional view illustrating examples of other steps in the manufacturing method of the light-emitting element according to the first embodiment of the present invention.

[0024] Figure 12 Is Figure 11 A schematic cross-sectional view of the light-emitting element obtained in the process shown.

[0025] Figure 13 This is a schematic cross-sectional view of the light-emitting element according to the second embodiment of the present invention.

[0026] Figure 14 This is a schematic cross-sectional view of the light-emitting element according to the third embodiment of the present invention.

[0027] Figure 15 This is a schematic cross-sectional view of the light-emitting element of a modified example of the first embodiment.

[0028] Figure 16 This is a schematic cross-sectional view showing one step of a method for manufacturing a light-emitting element according to another variation of the first embodiment.

[0029] Figure 17 This is a schematic cross-sectional view showing one step of a method for manufacturing a light-emitting element according to another variation of the first embodiment.

[0030] Figure 18 This is a schematic cross-sectional view showing one step of a method for manufacturing a light-emitting element according to another variation of the first embodiment.

[0031] Figure 19 This is a schematic cross-sectional view of a light-emitting element in another variation of the first embodiment. Detailed Implementation

[0032] The embodiments will now be described with reference to the accompanying drawings. It should be noted that the same reference numerals are used to label the same structures in each drawing.

[0033] [First Implementation Method]

[0034] Figure 1 This is a schematic top view showing a portion of the structure of the light-emitting element 1 according to the first embodiment of the present invention. Figure 2 It only means Figure 1 A schematic cross-sectional view of the end face at line II-II.

[0035] The light-emitting element 1 has a support substrate 100 and a semiconductor laminate 20 disposed on the support substrate 100.

[0036] Figure 3 It is a schematic cross-sectional view of an enlarged portion of the semiconductor stack 20.

[0037] The semiconductor stack 20 has a first conductive semiconductor layer 10, a second conductive semiconductor layer 15, and an active layer 14. The active layer 14 is disposed between the first conductive semiconductor layer 10 and the second conductive semiconductor layer 15 and is a light-emitting layer. For example, the peak wavelength of the light from the active layer 14 is below 400 nm, specifically above 210 nm and below 400 nm, more specifically above 300 nm and below 400 nm. For example, the active layer 14 emits ultraviolet light. It should be noted that because the thickness of the active layer 14 is thinner than the thickness of the first conductive semiconductor layer 10 and the second conductive semiconductor layer 15, therefore... Figure 2 The middle part is represented by lines. Furthermore, Figures 4 to 13 as well as Figures 15-19 Similarly, the active layer 14 is represented by lines.

[0038] The first conductivity semiconductor layer 10, the second conductivity semiconductor layer 15, and the active layer 14 are composed of nitride semiconductor layers. The nitride semiconductor contains In... x Al y Ga 1－x－y A semiconductor with the chemical formula N (0≤x≤1, 0≤y≤1, x+y≤1) containing all components in which the composition ratios of x and y vary within their respective ranges. The first conductive semiconductor layer 10 is a nitride semiconductor layer containing Al and Ga, such as an AlGaN layer. The first conductive semiconductor layer 10 is, for example, an n-type semiconductor layer. The first conductive semiconductor layer 10 contains, for example, Si as an n-type impurity. The second conductive semiconductor layer 15 is, for example, a p-type semiconductor layer. The second conductive semiconductor layer 15 contains, for example, Mg as a p-type impurity.

[0039] The first conductivity semiconductor layer 10 has a first layer 11 and a second layer 12. The first layer 11 and the second layer 12 are, for example, AlGaN layers. The Al content ratio of the first layer 11 is lower than that of the second layer 12. For example, the Al content ratio of the first layer 11 is 1% or more and 3% or less. The Al content ratio of the second layer 12 is 3% or more and 5% or less. The difference between the Al content ratio of the first layer 11 and the Al content ratio of the second layer 12 is preferably 1% or more and 4% or less. For example, the Al content ratio of the first layer 11 is 3%, and the Al content ratio of the second layer 12 is 5%.

[0040] The first conductive semiconductor layer 10 has a first region a1 and a second region a2. The first region a1 and the second region a2 each have a second layer 12. An active layer 14 and a second conductive semiconductor layer 15 are stacked on the second layer 12 in the first region a1. The active layer 14 and the second conductive semiconductor layer 15 are sequentially stacked on the side of the second layer 12 in the first region a1 on the side of the support substrate 100.

[0041] In the first region a1, the first layer 11 is not provided. On the first surface 12a opposite to the support substrate 100 in the second layer 12 of the first region a1, the first layer 11 is not provided; the first surface 12a is exposed from the first layer 11. The first surface 12a serves as the primary light extraction surface. In the top view, the first region a1 is the region where the first surface 12a is provided. In the cross-sectional view, the first region a1 is the region in the first conductive semiconductor layer 10 located directly below the first surface 12a.

[0042] In the second layer 12 of the second region a2, the first layer 11 is stacked, but the active layer 14 and the second conductive semiconductor layer 15 are not stacked. The second surface (second surface) 12b of the second layer 12 in the second region a2 on the support substrate 100 side exposes from the second conductive semiconductor layer 15 and the active layer 14. The second surface 12b functions as a contact surface with the first conductive member 40, which will be described later. In the top view, the second region a2 is the region where the second surface 12b is disposed. In the cross-sectional view, the second region a2 is the region in the first conductive semiconductor layer 10 directly above the second surface 12b.

[0043] like Figure 1 As shown, in the top view, multiple second regions a2 are arranged in an island-like pattern, each second region a2 being surrounded by a first region a1. In the top view, the area of ​​the first region a1 is larger than the total area of ​​the multiple second regions a2.

[0044] exist Figure 3In the example shown, a third region a3 exists between the first region a1 and the second region a2, comprising a first layer 11, a second layer 12, an active layer 14, and a second conductive semiconductor layer 15. The third region a3 is located between the first region a1 and the second region a2 and includes at least the first layer 11 and the second layer 12. Alternatively, the active layer 14 and the second conductive semiconductor layer 15 in the third region a3 can be removed, and the first region a1 and the second region a2 can be continuous.

[0045] In the second region a2, the first layer 11 and the second layer 12 are stacked. In the first region a1, the first layer 11 is not set, but the second layer 12 is set. Figure 2 In the example shown, the thickness of the first conductive semiconductor layer 10 in the first region a1 is thinner than the thickness of the first conductive semiconductor layer 10 in the second region a2. The thickness of the first conductive semiconductor layer 10 in the first region a1 or the second region a2 refers to the maximum thickness of the first conductive semiconductor layer 10 in the first region a1 or the second region a2.

[0046] Preferably, the thickness of the second layer 12 disposed in the second region a2 is thinner than the thickness of the first layer 11 disposed in the second region a2. For example, it is preferable that the thickness of the second layer 12 disposed in the second region a2 is 80% or less of the thickness of the first layer 11 disposed in the second region a2, and more preferably 70% or less. Preferably, the thickness of the first layer 11 disposed in the second region a2 is, for example, 0.3 μm or more and 3 μm or less, and more preferably 1 μm or more and 2.5 μm or less. For example, it is preferable that the thickness of the second layer 12 disposed in the second region a2 is, for example, 0.3 μm or more and 1.5 μm or less, and more preferably 0.5 μm or more and 1.2 μm or less. It should be noted that, as... Figure 15 As shown, the thickness of the first layer 11 can be the same as the thickness of the second layer 12. Here, the thickness of the first layer 11 set in the second region a2 refers to the maximum thickness of the first layer 11 set in the second region a2. Similarly, the thickness of the second layer 12 set in the second region a2 refers to the maximum thickness of the second layer 12 set in the second region a2.

[0047] The first layer 11 of the second region a2 has a third surface 11a on the opposite side of the surface on which the second layer 12 is stacked. A height difference is formed between the first surface 12a of the second layer 12 of the first region a1 and the third surface 11a of the first layer 11 of the second region a2. Figure 1 As shown, in the top view, the outer edge of the third surface 11a is located between the n-side conductive portion 40a of the first conductive component 40 and the outer edge of the reflective electrode 30.

[0048] The first surface 12a of the second layer 12 in the first region a1 is roughened to form an uneven surface. The third surface 11a of the first layer 11 in the second region a2 is also roughened to form an uneven surface. The size of the uneven surface of the first surface 12a and the size of the uneven surface of the third surface 11a are smaller than the size of the height difference between the first surface 12a and the third surface 11a.

[0049] The first surface 12a has a concave-convex shape comprising a plurality of first protrusions 10a. The third surface 11a has a concave-convex shape comprising a plurality of second protrusions 10b. The arithmetic mean height of the first protrusions 10a is greater than the arithmetic mean height of the second protrusions 10b. The first protrusions 10a and the second protrusions 10b are, for example, formed in a conical shape. The first protrusions 10a and the second protrusions 10b are in... Figure 3 In the sectional view, the height of the first protrusion 10a and the height of the second protrusion 10b are represented by a triangle.

[0050] like Figure 2 As shown, a first layer 11 and a second layer 12 are stacked on the outer periphery of the first conductive semiconductor layer 10. In this outer periphery, the second layer 12 does not have an active layer 14 and a second conductive semiconductor layer 15 stacked, thus forming a fourth surface 12c exposed from the active layer 14 and the second conductive semiconductor layer 15. The fourth surface 12c... Figure 1 In the top view shown, the region encloses the area where the first region a1 and the second region a2 are formed. The surface of the first layer 11, i.e., the fifth surface 11b, of the outer periphery of the first conductive semiconductor layer 10 is also roughened, and a plurality of second protrusions 10b are formed on the fifth surface 11b. The arithmetic mean height of the first protrusions 10a formed in the first region a1 is higher than the arithmetic mean height of the second protrusions 10b formed on the fifth surface 11b of the outer periphery of the first conductive semiconductor layer 10.

[0051] The light-emitting element 1 further comprises a first conductive component 40, a second conductive component 50, a third conductive component 60, a reflective electrode 30, a first electrode plate 71, a second electrode plate 72, and a first insulating film 81 to a fourth insulating film 84.

[0052] A reflective electrode 30 is provided on the surface of the second conductive semiconductor layer 15 (the side opposite to the surface where the active layer 14 is stacked). The reflective electrode 30 is in contact with and electrically connected to the surface of the second conductive semiconductor layer 15. Preferably, the reflective electrode 30 has high reflectivity relative to light emitted from the active layer 14. The reflective electrode 30 is, for example, a metal layer containing Ag. Here, high reflectivity of the reflective electrode 30 relative to light emitted from the active layer 14 means that the reflective electrode 30 has a reflectivity of 70% or more, preferably 80% or more, relative to the wavelength of light from the active layer 14.

[0053] The surface of the second conductive semiconductor layer 15 also has an area where the reflective electrode 30 is not disposed. This area is covered by the first insulating film 81. Furthermore, the first insulating film 81 also covers a portion of the reflective electrode 30. The first insulating film 81 is, for example, a silicon nitride film or a silicon oxide film.

[0054] The second insulating film 82 covers the first insulating film 81. The second insulating film 82 also covers the fourth surface 12c of the first conductive semiconductor layer 10, the side surface of the active layer 14, and the side surface of the second conductive semiconductor layer 15. The second insulating film 82 is, for example, a silicon oxide film.

[0055] A second conductive member 50 is provided on the surface of the second insulating film 82. The second conductive member 50 is, for example, a metal layer comprising at least one of Al and Cu. The second conductive member 50 has a p-side conductive portion 50a.

[0056] The reflective electrode 30 has a surface exposed from the first insulating film 81 and the second insulating film 82, and the p-side conductive portion 50a of the second conductive member 50 is in contact with this surface. The second conductive member 50 is electrically connected to the second conductive semiconductor layer 15 stacked in the first region a1 via the p-side conductive portion 50a and the reflective electrode 30.

[0057] The third insulating film 83 covers the second conductive component 50. The third insulating film 83 is, for example, a silicon oxide film.

[0058] A first conductive component 40 is provided on the surface of the third insulating film 83. The first conductive component 40 is, for example, a metal layer comprising at least one of Al and Cu. The first conductive component 40 has an n-side conductive portion 40a.

[0059] A portion of the second surface 12b of the second layer 12 in the second region a2 is covered by a second insulating film 82. The second surface 12b is, for example, circular in a top view, with a first insulating film 81 disposed on its outer periphery. The portion including the center of the second surface 12b protrudes from the first insulating film 81 and contacts the n-side conductive portion 40a of the first conductive member 40. The first conductive member 40 is electrically connected to the first conductive semiconductor layer 10 via the n-side conductive portion 40a.

[0060] A third insulating film 83 is provided between the first conductive component 40 and the second conductive component 50, and the first conductive component 40 and the second conductive component 50 are separated by the third insulating film 83.

[0061] like Figure 1 As shown, the support substrate 100 is formed as a square in the top view. A first electrode 71 and a second electrode 72 are disposed at opposite corners of the support substrate 100. In the top view, the semiconductor laminate 20 is formed as an approximately square with the first electrode 71 and the second electrode 72 disposed thereon, lacking the opposite corners.

[0062] like Figure 2 As shown, the first conductive member 40 has an electrode connection portion 40b located below the first electrode 71. A third conductive member 60 is provided on the electrode connection portion 40b. The third conductive member 60 can be formed, for example, using the same material and the same process as the second conductive member 50. The third conductive member 60 is formed as an island separate from the second conductive member 50. The first electrode 71 is provided on the third conductive member 60. The first electrode 71 is electrically connected to the first conductive member 40 via the third conductive member 60.

[0063] The second conductive component 50 has an electrode connection portion 50b located below the second electrode 72. The second electrode 72 is provided on the electrode connection portion 50b and is electrically connected to the second conductive component 50.

[0064] The first electrode 71 and the second electrode 72, for example, contain at least one metallic material selected from the group consisting of Ti, Pt and Au.

[0065] The first conductive component 40 is bonded to the support substrate 100 via a bonding layer 101. The bonding layer 101 is, for example, a metal layer containing a soldering material such as Sn. The support substrate 100 is, for example, a silicon substrate.

[0066] The upper surface and side surfaces of the semiconductor stack 20 are covered by a fourth insulating film 84. The upper surface of the semiconductor stack 20 includes a first surface 12a of the second layer 12 in the first region a1, a third surface 11a of the first layer 11 in the second region a2, and a fifth surface 11b of the first layer 11 in the outer periphery. The fourth insulating film 84 is, for example, a silicon oxide film.

[0067] Undulations are also formed on the surface of the fourth insulating film 84, which covers the irregularities including the plurality of first protrusions 10a formed on the first surface 12a of the first region a1. Undulations are also formed on the surface of the fourth insulating film 84, which covers the irregularities including the plurality of second protrusions 10b formed on the third surface 11a of the second region a2. Undulations are also formed on the surface of the fourth insulating film 84, which covers the irregularities including the plurality of second protrusions 10b on the fifth surface 11b of the first layer 11 of the outer periphery of the first conductive semiconductor layer 10.

[0068] The arithmetic mean height of the plurality of protrusions formed on the surface of the fourth insulating film 84 in the first region a1 is higher than the arithmetic mean height of the plurality of protrusions formed on the surface of the fourth insulating film 84 in the second region a2. Furthermore, the arithmetic mean height of the plurality of protrusions formed on the surface of the fourth insulating film 84 in the first region a1 is higher than the arithmetic mean height of the plurality of protrusions formed on the surface of the fourth insulating film 84 at the outer periphery of the first conductive semiconductor layer 10. By forming protrusions with a height higher than the arithmetic mean height on the surface of the fourth insulating film 84 in the first region a1, where the active layer 14 is stacked and which makes a significant contribution to light extraction efficiency, light extraction efficiency can be improved.

[0069] Light emitted from the active layer 14 propagates through the first conductive semiconductor layer 10 and is extracted from the outside of the semiconductor stack 20. Since the Al content of the second layer 12 in the first conductive semiconductor layer 10 is higher than that of the first layer 11, the light absorption rate of the second layer 12 is lower than that of the first layer 11. Especially when emitting relatively short wavelength light with a peak wavelength below 400 nm from the active layer 14, using AlGaN with a high Al content in the first conductive semiconductor layer 10 can suppress the light absorption of the first conductive semiconductor layer 10 more effectively than using GaN. The light absorption in the first region a1 where the active layer 14 is stacked has a greater impact on the light extraction efficiency of the semiconductor stack 20 compared to the light absorption in the second region a2 where the active layer 14 is not stacked. Therefore, by not providing a first layer 11 in the first region a1 with a higher light absorption rate than the second layer 12, the light extraction efficiency can be improved to a level higher than when the first layer 11 is provided in the first region a1.

[0070] Furthermore, since the first layer 11 is not provided in the first region a1, the thickness of the first conductive semiconductor layer 10 in the first region a1 is thinner than the thickness of the first conductive semiconductor layer 10 in the second region a2. By thinning the first conductive semiconductor layer 10 in the first region a1, which has a significant impact on light extraction efficiency, light absorption in the first region a1 can be suppressed, thereby improving the light extraction efficiency.

[0071] In the second region a2, the first conductive member 40 is connected to the first conductive semiconductor layer 10 and is provided with a current-conducting portion relative to the first conductive semiconductor layer 10. In this second region a2, by providing not only the second layer 12 but also a first layer 11 with an Al content lower than that of the second layer 12, the forward voltage (driving voltage) Vf can be reduced compared to the case where the first layer 11 is not provided in the second region a2, and current concentration in the second region a2 can be suppressed. Furthermore, by making the thickness of the first conductive semiconductor layer 10 in the second region a2 greater than the thickness of the first conductive semiconductor layer 10 in the first region a1, the resistance of the second region a2 can be reduced, thereby reducing Vf.

[0072] As the Al content of the nitride semiconductor layer, which includes Al and Ga, increases, the crack initiation rate in the nitride semiconductor layer tends to increase. Furthermore, as the thickness of the nitride semiconductor layer, which includes Al and Ga, increases, the crack initiation rate in the nitride semiconductor layer tends to increase. According to this embodiment, by forming the second layer 12, whose Al content is higher than that of the first layer 11, to be thinner than the thickness of the first layer 11, the occurrence of cracks in the first conductive semiconductor layer 10 can be suppressed.

[0073] To suppress light absorption in the first region a1, reduce Vf in the second region a2, and suppress crack formation in the first conductive semiconductor layer 10, the Al content of the first conductive semiconductor layer 10 is preferably 1% or more and 5% or less. Furthermore, the thickness of the second layer 12 in the second region a2 is preferably thinner than the thickness of the first layer 11 in the second region a2. For example, the thickness of the second layer 12 in the second region a2 is preferably 80% or less of the thickness of the first layer 11 in the second region a2. By making the thickness of the second layer 12 in the second region a2 thinner than the thickness of the first layer 11 in the second region a2, crack formation in the first conductive semiconductor layer 10 can be suppressed, and Vf in the second region a2 can be reduced.

[0074] Since some of the light extracted from the first region a1 may be absorbed by the first layer 11 disposed in the second region a2, it is preferable to separate the distance between the first region a1 and the second region a2 to suppress light absorption. On the other hand, if the distance between the first region a1 and the second region a2 is too large, the top-view area of ​​the second region a2 may become smaller, and current concentration in the second region a2 may occur. According to this embodiment, in the top view, the outer edge of the third surface 11a is located between the outer edge of the n-side conductive portion 40a of the first conductive member 40 and the outer edge of the reflective electrode 30. As a result, light absorption by the first layer 11 disposed in the second region a2 can be suppressed, and current concentration in the second region a2 can be suppressed.

[0075] The first conductive member 40 can be electrically connected to the fourth surface 12c of the second layer 12 in the outer periphery of the first conductive semiconductor layer 10. In this case, by providing not only the second layer 12 but also a first layer 11 with a lower Al content than the second layer 12 in the outer periphery of the first conductive semiconductor layer 10, Vf can be reduced compared to the case where the first layer 11 is not provided in the outer periphery. Furthermore, the occurrence of cracks in the outer periphery can be suppressed.

[0076] Next, refer to Figures 4 to 11 The manufacturing method of the light-emitting element 1 according to the first embodiment of the present invention will be described.

[0077] like Figure 4 As shown, a bottom layer 201 comprising an undoped GaN layer is grown on a substrate 200, for example. The thickness of the bottom layer 201 is, for example, 6 μm or more and 8 μm or less. Furthermore, a semiconductor stack 20 is formed via the bottom layer 201. The substrate 200 is a substrate for growing a nitride semiconductor layer, for example, a sapphire substrate. Before growing the bottom layer 201 on the substrate 200, a buffer layer, for example, composed of AlGaN or AlN, may be formed.

[0078] The semiconductor stack 20 includes a first conductive semiconductor layer 10, an active layer 14, and a second conductive semiconductor layer 15. The first conductive semiconductor layer 10 includes a first layer 11 and a second layer 12. The first layer 11, the second layer 12, the active layer 14, and the second conductive semiconductor layer 15 are epitaxially grown sequentially on the bottom layer 201. The semiconductor layers included in the semiconductor stack 20 can be formed using methods such as MOCVD (metal-organic chemical vapor deposition).

[0079] As previously described, the first conductive semiconductor layer 10 is a nitride semiconductor layer comprising Al and Ga, and the Al content of the first layer 11 is lower than that of the second layer 12. For example, the Al content of the first layer 11 is 3%, and the Al content of the second layer 12 is 5%.

[0080] In the process of forming the semiconductor stack 20, it is preferable that the thickness of the first layer 11 is, for example, 0.3 μm or more and 3 μm or less, and more preferably 1 μm or more and 2.5 μm or less. For example, it is preferable that the thickness of the second layer 12 is, for example, 0.3 μm or more and 1.5 μm or less, and more preferably 0.5 μm or more and 1.2 μm or less. For example, the thickness of the first layer 11 is 2 μm and the thickness of the second layer 12 is 1 μm. By making the thickness of the second layer 12, which has a higher Al content than the first layer 11, thinner than the thickness of the first layer 11, the occurrence of cracks generated during the growth of the first conductive semiconductor layer 10 can be suppressed.

[0081] After the semiconductor stack 20 is formed, as Figure 5 As shown, a portion of the second conductive semiconductor layer 15 and a portion of the active layer 14 are removed. For example, a portion of the second conductive semiconductor layer 15 and a portion of the active layer 14 are removed by the Reactive Ion Etching (RIE) method. By removing a portion of the second conductive semiconductor layer 15 and a portion of the active layer 14, a portion of the second layer 12 of the first conductive semiconductor layer 10 is exposed from the second conductive semiconductor layer 15 and the active layer 14.

[0082] The first region a1 is located in the portion where the second conductive semiconductor layer 15 and the active layer 14 are not removed and remain. The second region a2 is located in a portion of the second layer 12 exposed from the second conductive semiconductor layer 15 and the active layer 14 (the second surface 12b that becomes a conductive portion relative to the first conductive semiconductor layer 10).

[0083] Subsequently, with the semiconductor laminate 20 formed on the substrate 200, refer to Figure 2 The aforementioned reflective electrode 30, first insulating film 81, second insulating film 82, second conductive component 50, third conductive component 60, third insulating film 83, and first conductive component 40 are formed. The reflective electrode 30, first insulating film 81, second insulating film 82, second conductive component 50, third conductive component 60, third insulating film 83, and first conductive component 40 can be formed, for example, using sputtering, vapor deposition, or other methods. It should be noted that the second conductive component 50 and the third conductive component 60 can be formed through the same process. The p-side conductive portion 50a of the second conductive component 50 contacts the reflective electrode 30, and the n-side conductive portion 40a of the first conductive component 40 contacts the second surface 12b of the first conductive semiconductor layer 10.

[0084] After that, as Figure 6 As shown, the first conductive component 40 is bonded to the support substrate 100 via the bonding layer 101. It should be noted that... Figure 6 The relationship between superior and subordinate Figure 5 Conversely, when supported on substrate 200, semiconductor laminate 20 is bonded to support substrate 100.

[0085] After bonding the semiconductor laminate 20 to the support substrate 100, the substrate 200 is removed, and the bottom layer 201 is also removed. Thus, as... Figure 7 As shown, the surface of the first layer 11 of the first conductive semiconductor layer 10 is exposed.

[0086] like Figure 8 As shown, a mask 91 is formed on the exposed surface of the first layer 11 to selectively remove the first conductive semiconductor layer 10, for example, by means of a re-extraction (RIE) method. No mask 91 is formed on the first layer 11 in a first region a1 on which the active layer 14 and the second conductive semiconductor layer 15 are stacked. The first layer 11 in this first region a1 is removed, exposing the second layer 12. In this example, the entire first layer 11 in the first region a1 is removed.

[0087] The first layer 11 of the second region a2, including the second surface 12b connected to the n-side conductive portion 40a of the first conductive component 40, is covered by the mask 91 and is not removed. The second layer 12 and the first layer 11, which is thicker than the second layer 12 and has a lower Al content compared to the second layer 12, remain in the second region a2.

[0088] The mask 91 is also disposed in the region of the first conductive semiconductor layer 10 that is located on the outer side compared to the first region a1, so the first layer 11 in the region on the outer side compared to the first region a1 is not removed and remains.

[0089] After selectively removing the first layer 11, the mask 91 is removed. After removing the mask 91, as... Figure 9 As shown, the first layer 11 and the second layer 12 are removed from the region located outside the first region a1. In a portion of the region located outside the first region a1, the stacked portion of the first layer 11 and the second layer 12 remains as the outer periphery of the first conductive semiconductor layer 10. In the region located outside this outer periphery, the second insulating film 82 is exposed from the first layer 11 and the second layer 12.

[0090] Through the above procedures, such as Figure 9 As shown, in the first region a1, the surface of the second layer 12 is exposed as the first surface 12a; in the second region a2, the surface of the first layer 11 is exposed as the third surface 11a; and in the outer periphery, the surface of the first layer 11 is exposed as the fifth surface 11b. These surfaces are then roughened. For example, TMAH (tetramethylammonium hydroxide) is used to roughen their surfaces. Preferably, the thickness of the first layer 11 after the roughening process is, for example, 0.3 μm or more and 3 μm or less, more preferably 1 μm or more and 2.5 μm or less. Furthermore, preferably, the thickness of the second layer 12 after the roughening process is, for example, 0.3 μm or more and 1.5 μm or less, more preferably 0.5 μm or more and 1.2 μm or less.

[0091] like Figure 10 As shown, a plurality of first protrusions 10a are formed on the first surface 12a of the second layer 12 in the first region a1, and a plurality of second protrusions 10b are formed on the third surface 11a of the first layer 11 in the second region a2 and the fifth surface 11b of the first layer 11 in the outer periphery.

[0092] In wet etching using TMAH with nitride semiconductor layers containing Al and Ga, a higher Al content results in a higher etching rate but also tends to increase surface roughness. Since the Al content of the second layer 12 is higher than that of the first layer 11, the arithmetic mean height of the first protrusion 10a formed on the first surface 12a of the second layer 12 is also higher than the arithmetic mean height of the second protrusion 10b formed on the third surface 11a and the fifth surface 11b of the first layer 11. By increasing the height of the first protrusion 10a on the first surface 12a of the first region a1, where the active layer 14 is stacked and which contributes significantly to light extraction efficiency, the light extraction efficiency can be improved.

[0093] On the other hand, since the Al content of the first layer 11 is lower than that of the second layer 12, there is a tendency for the etching rate of the first layer 11 in wet etching to be lower than that of the second layer 12. By suppressing the amount of etching on the third surface 11a of the second region a2, the reduction in the film thickness of the first layer 11 in the second region a2 can be suppressed. Since the Al content of the first layer 11 is lower than that of the second layer 12, by suppressing the reduction in the film thickness of the first layer 11 in the second region a2 connected to the n-side conductive portion 40a of the first conductive member 40, the forward voltage (driving voltage) Vf can be reduced as described above.

[0094] After roughening the surface of the first conductive semiconductor layer 10, a fourth insulating film 84 is formed covering the first conductive semiconductor layer 10 and the second insulating film 82. Then, a portion of the second insulating film 82 and a portion of the fourth insulating film 84, located in the region outer of the first conductive semiconductor layer 10, are removed. Thus, as... Figure 2 As shown, a portion of the second conductive member 50 is exposed from the second insulating film 82 as an electrode connection portion 50b, and a second electrode 72 is formed on the electrode connection portion 50b. Furthermore, a portion of the third conductive member 60 is exposed from the second insulating film 8, and a first electrode 71 is formed on the third conductive member 60.

[0095] In the foregoing Figure 8 In the process shown, after the first layer 11 of the first region a1 is removed by using a mask 91 to expose the first surface 12a of the second layer 12 of the first region a1 from the first layer 11, and the third surface 11a of the first layer 11 of the second region a2 is covered by the mask 91 in this state, the first surface 12a of the second layer 12 of the first region a1 can be roughened by etching, for example, the first surface 12a of the second layer 12 of the first region a1 by TMAH.

[0096] like Figure 11As shown, by roughening the surface of the first layer 11 of the second region a2 while the third surface 11a is covered by a mask 91, a plurality of first protrusions 10a are formed on the first surface 12a of the second layer 12 of the first region a1, and no unevenness is formed on the third surface 11a of the first layer 11 of the second region a2 covered by the mask 91. The mask 91 used in the removal process of the first layer 11 of the first region a1 can also be used in the roughening of the first surface 12a of the second layer 12 of the first region a1, thus simplifying the process. Furthermore, by using such a process for roughening, as Figure 12 As shown, the third surface 11a of the first layer 11 in the second region a2 is not etched and remains as a flat surface. Therefore, the first layer 11 in the second region a2 can be made into a thicker film, which can reduce Vf.

[0097] [Second Implementation]

[0098] Figure 13 This is a schematic cross-sectional view of the light-emitting element according to the second embodiment of the present invention. The light-emitting element of the second embodiment, in addition to the matters described below, possesses... Figure 2 The structure is the same as the first embodiment shown. In the following description, only the differences from the first embodiment will be described in principle.

[0099] In this embodiment, the first conductive semiconductor layer 10 further comprises a third layer 13 in addition to the first layer 11 and the second layer 12. The third layer 13 is also a nitride semiconductor layer containing Al and Ga, such as an AlGaN layer. The Al content ratio of the second layer 12 is higher than that of the first layer 11, and the Al content ratio of the third layer 13 is higher than that of the second layer 12. Preferably, the difference between the Al content ratio of the first layer 11 and the Al content ratio of the second layer 12 is 1% or more and 4% or less. Preferably, the difference between the Al content ratio of the second layer 12 and the Al content ratio of the third layer 13 is greater than 0% and less than 4%. For example, the Al content ratio of the first layer 11 is 3%, the Al content ratio of the second layer 12 is 4%, and the Al content ratio of the third layer 13 is 5%. From the viewpoint of suppressing light absorption of the first conductive semiconductor layer 10, it is preferable that the difference between the Al content ratio of the first layer 11 and the Al content ratio of the second layer 12 is 2% or more. For example, the Al content of the first layer 11 is 3%, the Al content of the second layer 12 is 5%, and the Al content of the third layer 13 is 6%.

[0100] In this embodiment, for example, a first layer 11, a second layer 12, and a third layer 13 are sequentially formed on a substrate 200 via a bottom layer 201. An active layer 14 is formed on the third layer 13, and a second conductive semiconductor layer 15 is formed on the active layer 14.

[0101] Instead of providing a first layer 11 in the first region a1, a second layer 12 with a higher Al content compared to the first layer 11 and a third layer 13 with a higher Al content compared to the second layer 12 are provided. By not providing a first layer 11 in the first region a1, which has a lower Al content and higher light absorption rate compared to the second layer 12 and the third layer 13, the light extraction efficiency can be improved compared to the case where a first layer 11 is provided in the first region a1. Furthermore, by providing a third layer 13, which has a higher Al content and lower light absorption rate compared to the second layer 12, closer to the active layer 14 than the second layer 12, the light absorption in the first region a1 can be further suppressed.

[0102] Furthermore, since the first layer 11 is not provided in the first region a1, the thickness of the first conductive semiconductor layer 10 in the first region a1 is thinner than the thickness of the first conductive semiconductor layer 10 in the second region a2. By thinning the first conductive semiconductor layer 10 in the first region a1, which has a significant impact on light extraction efficiency, light absorption in the first region a1 can be suppressed, thereby improving the light extraction efficiency.

[0103] A first layer 11, a second layer 12, and a third layer 13 are stacked in the second region a2. An active layer 14 and a second conductive semiconductor layer 15 are not stacked in the second region a2. The sixth surface 13a of the third layer 13 in the second region a2, on the side of the support substrate 100, is exposed from the second conductive semiconductor layer 15 and the active layer 14. The n-side conductive portion 40a of the first conductive member 40 is in contact with the sixth surface 13a.

[0104] By also providing a first layer 11 with a lower Al content ratio than the second layer 12 and the third layer 13 in the second region a2, the forward voltage (driving voltage) Vf can be reduced compared to the case where the first layer 11 is not provided in the second region a2, and current concentration in the second region a2 can be suppressed. In addition, by making the thickness of the first conductive semiconductor layer 10 in the second region a2 greater than the thickness of the first conductive semiconductor layer 10 in the first region a1, the resistance of the second region a2 and Vf can be reduced.

[0105] [Third Implementation Method]

[0106] Figure 14 This is a schematic cross-sectional view of the light-emitting element according to the third embodiment of the present invention. Figure 14 With the above Figure 3 Similarly, this is a schematic cross-sectional view of an enlarged portion of the semiconductor stack 20.

[0107] According to the third embodiment, a portion 11c of the first layer 11 is provided in the first region a1. The thickness of the portion 11c of the first layer 11 provided in the first region a1 is thinner than the thickness of the second layer 12 provided in the first region a1, and also thinner than the thickness of the first layer 11 provided in the second region a2. The thickness of the portion 11c of the first layer 11 provided in the first region a1 refers to the maximum thickness of the portion 11c of the first layer 11 provided in the first region a1.

[0108] In the third embodiment, as described above Figure 7 In the illustrated process, after exposing the surface of the first layer 11, not all of the first layer 11 disposed in the first region a1 is removed, but only a portion of the first layer 11 disposed in the first region a1 is removed. Furthermore, a first layer 11 that is thicker than the first layer 11 disposed in the first region a1 remains in the second region a2. In the process of removing a portion of the first layer 11, not all of the first layer 11 disposed in the first region a1 is removed, but a first layer 11 and a second layer 12 that are thinner than the second region a2 remain in the first region a1. Then, the first region a1 and the second region a2 are roughened, for example, by TMAH etching.

[0109] exist Figure 14 In the example shown, a portion 11c of the first layer 11 is disposed on top of a cone-shaped first protrusion 10a disposed on the surface of the second layer 12 in the first region a1. The thickness of the portion 11c of the first layer 11 is less than the height of the first protrusion 10a of the second layer 12. In the third embodiment, the first protrusion 10a is located at... Figure 14 In the cross-sectional view, it is represented by a trapezoid, and the height of the first protrusion 10a represents the height of the trapezoid. A portion 11c of the first layer 11 is... Figure 14 In the cross-sectional view, it is represented by a triangle, and the thickness of a portion 11c of the first layer 11 represents the height of the triangle.

[0110] Compared with the second layer 12, the first layer 11 has a lower Al content and a higher light absorption rate. By limiting the first layer 11 in the first region a1 to a portion 11c that is thinner than the second layer 12 and thinner than the first layer 11 in the second region a2, the light absorption of the first layer 11 in the first region a1 can hardly affect the light extraction efficiency.

[0111] Next, refer to Figures 16-18 The manufacturing method of the light-emitting element in other variations of the first embodiment will be described. It should be noted that this variation can also be applied to the second and third embodiments.

[0112] Reference Figure 4 After forming the semiconductor stack 20 on the substrate 200 as described above, as Figure 16As shown, a process can be performed to modify a portion of the surface of the second conductive semiconductor layer 15. In Figure 16 In the following figures, the surface of the region indicated by the dotted lines of the second conductive semiconductor layer 15 is improved. For example, a mask 500 is formed on a portion of the surface of the second conductive semiconductor layer 15 located on the first region a1 of the aforementioned first conductive semiconductor layer 10. Furthermore, for example, the surface of the second conductive semiconductor layer 15 exposed from the mask 500 is subjected to plasma treatment in an atmosphere containing oxygen.

[0113] The surface of the second conductive semiconductor layer 15, in its modified form, has a higher resistance compared to the surface of the unmodified second conductive semiconductor layer 15. Specifically, a low-resistance portion (unmodified portion) 15a and a high-resistance portion (modified portion) 15b, which has a higher resistivity than the low-resistance portion 15a, are formed on the surface of the second conductive semiconductor layer 15.

[0114] After that, as Figure 17 As shown, a reflective electrode 30 is formed on the surface of the second conductive semiconductor layer 15, covering both the low-resistance portion 15a and the high-resistance portion 15b. The reflective electrode 30 contacts the entire surface of the low-resistance portion 15a. The reflective electrode 30 contacts a portion of the high-resistance portion 15b. The area of ​​the reflective electrode 30 in contact with the low-resistance portion 15a is larger than the area of ​​the reflective electrode 30 in contact with the high-resistance portion 15b. After the reflective electrode 30 is formed, a first insulating film 81 is formed to cover the reflective electrode 30 and the surface of the second conductive semiconductor layer 15.

[0115] After that, as Figure 18 As shown, a portion of the first insulating film 81, a portion of the second conductive semiconductor layer 15, and a portion of the active layer 14 are removed. As a result, a portion of the second layer 12 of the first conductive semiconductor layer 10 is exposed from the second conductive semiconductor layer 15 and the active layer 14. The surface of the remaining second conductive semiconductor layer 15, which is not removed, includes a low-resistance portion 15a and a high-resistance portion 15b.

[0116] Then, continuing from the above. Figure 6 The subsequent processes can obtain Figure 19The light-emitting element is shown. A low-resistance portion 15a and a high-resistance portion 15b are included on the surface of a second conductive semiconductor layer 15 stacked in a first region a1 of the first conductive semiconductor layer 10. The high-resistance portion 15b includes a high-resistance portion 15bc located near a second region a2 compared to the low-resistance portion 15a. Furthermore, the high-resistance portion 15b includes a high-resistance portion 15ba located near the outer periphery of the first conductive semiconductor layer 10 compared to the low-resistance portion 15a. The current density of the high-resistance portion 15b is lower than that of the low-resistance portion 15a, and the active layer 14 in the region where the high-resistance portion 15b is located emits light more strongly than the active layer 14 in the region where the low-resistance portion 15a is located.

[0117] In the first conductive semiconductor layer 10, by positioning the high-resistivity portion 15b close to the second region 11a and the outer periphery of the first layer 11, which has a higher light absorption rate than the second layer 12, the light emission in the region near the first layer 11 can be reduced, and the light absorption of the first layer 11 can be suppressed. Since the reflective electrode 30 is also in contact with the high-resistivity portion 15b, the area of ​​the reflective electrode 30 can be maintained, and the light absorption of the first layer 11 can be suppressed, thereby improving the light extraction efficiency.

[0118] exist Figure 19 In the cross-section, the width of the contact between the reflective electrode 30 and the high-resistance portion 15b is preferably 3 μm or more and 25 μm or less, and more preferably 5 μm or more and 20 μm or less.

[0119] exist Figure 19 In the cross-section, it is preferable that the width of the high-resistance portion 15ba located on the side near the outer periphery of the first conductive semiconductor layer 10 is greater than the width of the high-resistance portion 15bc located on the side near the second region a2. By making the width of the high-resistance portion ba on the outer periphery side, which is arranged over a larger area than the second region a2, greater than the width of the high-resistance portion 15bc, the light absorption suppression effect of the first layer 11 can be improved.

[0120] The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. All embodiments implemented by those skilled in the art based on the above-described embodiments of the present invention with appropriate design modifications, as long as they contain the spirit of the present invention, fall within the scope of the present invention. Furthermore, within the scope of the concept of the present invention, those skilled in the art can conceive of various modifications and alterations, which also fall within the scope of the present invention.

[0121] Explanation of reference numerals in the attached figures

[0122] 1…Light-emitting element, 10…First conductive semiconductor layer, 10a…First protrusion, 10b…Second protrusion, 11…First layer, 11a…Third surface, 11b…Fifth surface, 12…Second layer, 12a…First surface, 12b…Second surface, 12c…Fourth surface, 13…Third layer, 13a…Sixth surface, 14…Active layer, 15…Second conductive semiconductor layer, 20…Semiconductor laminate, 30…Reflective electrode, 40…First conductive component, 50…Second conductive component, 60…Third conductive component, 71…First electrode plate, 72…Second electrode plate, 81…First insulating film, 82…Second insulating film, 83…Third insulating film, 84…Fourth insulating film, 100…Support substrate, 101…Bonding layer, 200…Substrate, a1…First region, a2…Second region.

Claims

1. A light-emitting element, characterized in that, have: A semiconductor stack having a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer; A first conductive component is electrically connected to the first conductive semiconductor layer; The second conductive component is electrically connected to the second conductive semiconductor layer; The first conductivity semiconductor layer is a nitride semiconductor layer containing Al and Ga, having a first layer and a second layer, wherein the Al content of the first layer is lower than the Al content of the second layer. The first conductive semiconductor layer has a first region in which the second conductive semiconductor layer and the active layer are stacked, and a second region exposed from the second conductive semiconductor layer and the active layer and connected to the first conductive component. The thickness of the first layer in the first region is thinner than the thickness of the first layer in the second region, or the first layer is not provided in the first region. The surface of the first layer in the second region is formed as a flat surface, and a plurality of first protrusions are formed on the surface of the second layer in the first region.

2. The light-emitting element according to claim 1, The thickness of the second layer disposed in the second region is thinner than the thickness of the first layer disposed in the second region.

3. The light-emitting element according to claim 1 or 2, The thickness of the second layer disposed in the second region is less than 80% of the thickness of the first layer disposed in the second region.

4. The light-emitting element according to claim 1 or 2, The peak wavelength of light in the active layer is below 400 nm.

5. The light-emitting element according to claim 1 or 2, The second conductive component is connected to the second conductive semiconductor layer stacked in the first region.

6. A method for manufacturing a light-emitting element, characterized in that, have: The process of forming a semiconductor stack including a first conductive semiconductor layer, an active layer disposed on the first conductive semiconductor layer, and a second conductive semiconductor layer disposed on the active layer on a substrate, wherein the first conductive semiconductor layer is a nitride semiconductor layer containing Al and Ga, and has a first layer disposed on the substrate and a second layer disposed on the first layer, wherein the Al content ratio of the first layer is lower than the Al content ratio of the second layer. The process of removing a portion of the second conductive semiconductor layer and a portion of the active layer, exposing a portion of the first conductive semiconductor layer from the second conductive semiconductor layer and the active layer, forming a first region remaining in the first conductive semiconductor layer without removing the second conductive semiconductor layer and the active layer, and a second region containing the portion of the first conductive semiconductor layer exposed from the second conductive semiconductor layer and the active layer; The process of removing the substrate after the first region and the second region have been formed, thereby exposing the surface of the first layer of the first conductive semiconductor layer. The process of removing at least a portion of the first layer disposed in the first region after exposing the surface of the first layer, leaving a first layer that is thicker than the first layer disposed in the first region in the second region, or exposing the second layer disposed in the first region from the first layer; The process of forming a flat surface on the surface of the first layer in the second region and forming a plurality of first protrusions on the surface of the second layer in the first region.

7. The method for manufacturing a light-emitting element according to claim 6, The process further includes forming a plurality of first protrusions on the surface of the second layer in the first region after removing at least a portion of the first layer disposed in the first region. In the process of removing at least a portion of the first layer disposed in the first region, while the surface of the first layer in the second region is covered by a mask, at least a portion of the first layer in the first region is removed. Using the mask, the first region is etched to form a plurality of the first protrusions.

8. The method for manufacturing the light-emitting element according to claim 6 or 7, In the process of forming the semiconductor stack, the second layer is formed to be thinner than the first layer.

9. The method for manufacturing a light-emitting element according to claim 6 or 7, In the process of forming the semiconductor stack, the thickness of the second layer is made to be less than 50% of the thickness of the first layer.

10. The method for manufacturing the light-emitting element according to claim 6 or 7, The peak wavelength of the light from the active layer is below 400 nm.

11. The method for manufacturing a light-emitting element according to claim 6 or 7, comprising: The process of forming a low-resistivity portion and a high-resistivity portion that is higher than the low-resistivity portion and located near the second region compared to the low-resistivity portion on the surface of a second conductive semiconductor layer on the first region of the first conductive semiconductor layer; The process of forming electrodes on the surface of the second conductive semiconductor layer in such a way that the area in contact with the low-resistance portion is larger than the area in contact with the high-resistance portion.

12. The method for manufacturing a light-emitting element according to claim 11, The high-resistivity portion is formed by plasma treatment of the surface of the second conductive semiconductor layer.

Images