Semiconductor light-emitting element

Abstract

The semiconductor light-emitting element includes: a semiconductor layer made of a compound semiconductor; and an n-side electrode disposed on the semiconductor layer, having a power supply portion and an extension portion extending from the power supply portion; the width of the power supply portion is larger than the width of the extension portion; the n-side electrode has an n-side electrode layer disposed on the semiconductor layer side and an n-side wiring layer disposed above the n-side electrode layer; the n-side electrode layer has a first metal layer disposed in the power supply portion and a second metal layer disposed on the extension portion side of the first metal layer and directly connected to the first metal layer; the first metal layer and the second metal layer are ohmic-connected to the semiconductor layer; the conductivity of the first metal layer is higher than the conductivity of the second metal layer; the n-side wiring layer is continuously disposed on the first metal layer and the second metal layer.

Description

Field of the Invention

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

[0002] Semiconductor light-emitting elements such as LEDs (Light Emitting Diodes) are used as light sources for various devices such as for lighting or for displays. Among various light sources, in the field of relatively large light output, for example, LEDs are used as light sources for in-vehicle lighting devices such as DRL (Daytime Running Lights) and HL (Head Lamp).

[0003] A semiconductor light-emitting element includes, for example, an active layer (light-emitting layer), semiconductor layers on both sides of the active layer, and electrodes. An electrode has an electrode layer in ohmic contact with the semiconductor layer and a wiring layer laminated on the electrode layer. In a plan view, an electrode is sometimes formed to have a portion where the width varies. In this case, portions where the width varies are formed in the electrode layer and the wiring layer constituting the electrode, respectively.

[0004] However, if there is a portion where the width of the electrode varies, in the portion where the width of the electrode becomes narrow, the current density in the electrode layer locally increases, and electromigration (EM) may occur and the electrode layer may deteriorate.

[0005] Conventionally, in order to suppress electromigration in the portion where the current density increases, a technique has been proposed in which the electrode layer is truncated in the portion where the current density increases and an insulating layer is provided in the portion where the electrode layer is truncated (for example, Patent Document 1).

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2014-22413 Summary of the Invention

[0009] Problems to be Solved by the Invention

[0010] However, in the technique disclosed in Patent Document 1, although electromigration can be suppressed, there is a problem that the driving voltage increases.

[0011] The present invention has been made to solve such problems, and an object thereof is to provide a semiconductor light-emitting element capable of suppressing an increase in driving voltage and suppressing electromigration.

[0012] Means for Solving the Problems

[0013] One aspect of the semiconductor light-emitting device of the present invention includes: a semiconductor layer made of a compound semiconductor; and an electrode disposed on the semiconductor layer, having a power supply portion and an extension portion extending from the power supply portion; the width of the power supply portion is larger than the width of the extension portion; the electrode has an electrode layer disposed on the semiconductor layer side and a wiring layer disposed on the electrode layer; the electrode layer has a first metal layer disposed in the power supply portion and a second metal layer disposed on the extension portion side with respect to the first metal layer and directly connected to the first metal layer; the first metal layer and the second metal layer are ohmic-connected to the semiconductor layer; the conductivity of the first metal layer is higher than the conductivity of the second metal layer; the wiring layer is continuously disposed on the first metal layer and the second metal layer.

[0014] Advantages of the Invention

[0015] According to the present invention, an increase in the driving voltage can be suppressed and electromigration can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a diagram showing the structure of the semiconductor light-emitting device of Embodiment 1.

[0017] Figure 2A It is a diagram showing the step of preparing a substrate in the manufacturing method of the semiconductor light-emitting device of Embodiment 1.

[0018] Figure 2B It is a diagram showing the step of forming a semiconductor layer stack structure in the manufacturing method of the semiconductor light-emitting device of Embodiment 1.

[0019] Figure 2C It is a diagram showing the step of etching the semiconductor layer stack structure in the manufacturing method of the semiconductor light-emitting device of Embodiment 1.

[0020] Figure 2D It is a diagram showing the step of forming an insulating film in the manufacturing method of the semiconductor light-emitting device of Embodiment 1.

[0021] Figure 2E It is a diagram showing the step of forming a p-side electrode in the manufacturing method of the semiconductor light-emitting device of Embodiment 1.

[0022] Figure 2F It is a diagram showing the steps of forming the first metal layer and the third metal layer in the n-side electrode layer of the n-side electrode in the manufacturing method of the semiconductor light-emitting device of Embodiment 1.

[0023] Figure 2G It is a diagram showing the step of forming the second metal layer in the n-side electrode layer of the n-side electrode in the manufacturing method of the semiconductor light-emitting device of Embodiment 1.

[0024] Figure 2H This is a diagram showing the process of forming the n-side wiring layer of the n-side electrode in the manufacturing method of the semiconductor light-emitting element of Embodiment 1.

[0025] Figure 3 This is a diagram showing the structure around the n-side electrode of the semiconductor light-emitting element of Comparative Example 1 and the current density of the n-side electrode layer of the n-side electrode in the lateral direction (the extending direction of the extending portion).

[0026] Figure 4 This is a diagram showing the structure around the n-side electrode of the semiconductor light-emitting element of Comparative Example 2 and the current density of the n-side electrode layer of the n-side electrode in the lateral direction (the extending direction of the extending portion).

[0027] Figure 5 This is a diagram showing the structure around the n-side electrode of the semiconductor light-emitting element of Embodiment 1 and the current density of the n-side electrode layer of the n-side electrode in the lateral direction (the extending direction of the extending portion).

[0028] Figure 6 This is a diagram showing a modified example of the n-side electrode layer in the n-side electrode of the semiconductor light-emitting element of Embodiment 1.

[0029] Figure 7 This is a diagram showing another modified example of the n-side electrode layer in the n-side electrode of the semiconductor light-emitting element of Embodiment 1.

[0030] Figure 8 This is a diagram showing still another modified example of the n-side electrode layer in the n-side electrode of the semiconductor light-emitting element of Embodiment 1.

[0031] Figure 9 This is a diagram showing the relationship between the distance from the position of the width change (width change position) of the n-side electrode in the extending direction of the extending portion and the current density in the n-side electrode layer of the n-side electrode of the semiconductor light-emitting element of Embodiment 1.

[0032] Figure 10 This is a diagram showing the desired range for setting the second metal layer in each change of the n-side electrode layer of the n-side electrode of the semiconductor light-emitting element of Embodiment 1.

[0033] Figure 11 This is a diagram showing the structure of the semiconductor light-emitting element of Modified Example 1 of Embodiment 1.

[0034] Figure 12 This is a diagram showing another structure of the semiconductor light-emitting element of Modified Example 1 of Embodiment 1.

[0035] Figure 13It is a diagram showing the structure of a semiconductor light-emitting device according to Modification 2 of Embodiment 1.

[0036] Figure 14 It is a diagram showing another structure of a semiconductor light-emitting device according to Modification 2 of Embodiment 1.

[0037] Figure 15 It is a diagram showing the structure of a semiconductor light-emitting device according to Modification 3 of Embodiment 1.

[0038] Figure 16 It is a diagram showing another structure of a semiconductor light-emitting device according to Modification 3 of Embodiment 1.

[0039] Figure 17 It is a diagram showing yet another structure of a semiconductor light-emitting device according to Modification 3 of Embodiment 1.

[0040] Figure 18 It is a diagram showing the structure of a semiconductor light-emitting device according to Modification 4 of Embodiment 1.

[0041] Figure 19 It is a diagram showing another structure of a semiconductor light-emitting device according to Modification 4 of Embodiment 1.

[0042] Figure 20 It is a diagram showing yet another structure of a semiconductor light-emitting device according to Modification 4 of Embodiment 1.

[0043] Figure 21 It is a diagram showing the structure of a semiconductor light-emitting device according to Modification 5 of Embodiment 1.

[0044] Figure 22 It is a diagram showing the structure of a semiconductor light-emitting device according to Embodiment 2.

[0045] Figure 23 It is a diagram showing the structure of a semiconductor light-emitting device according to Modification 1 of Embodiment 2.

[0046] Figure 24 It is a diagram showing the structure of a semiconductor light-emitting device according to Modification 2 of Embodiment 2.

[0047] Figure 25 It is a diagram showing another structure of a semiconductor light-emitting device according to Modification 2 of Embodiment 2.

[0048] Figure 26 It is a diagram showing yet another structure of a semiconductor light-emitting device according to Modification 2 of Embodiment 2.

[0049] Figure 27 It is a diagram showing the structure of a semiconductor light-emitting device according to Modification 3 of Embodiment 2. Detailed implementation mode

[0050] (Embodiment)

[0051] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, all the embodiments described below represent a specific example of the present invention. Therefore, the numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of the constituent elements, and the processes and the order of the processes shown in the following embodiments are given as examples and are not intended to limit the present invention.

[0052] In addition, each drawing is a schematic diagram and is not necessarily strictly drawn. Therefore, the scales and the like are not necessarily the same in each drawing. In addition, in each drawing, the same reference numerals are given to substantially the same structures, and repeated descriptions are omitted or simplified.

[0053] (Embodiment 1)

[0054] [Semiconductor light-emitting element]

[0055] First, use Figure 1 to explain the structure of the semiconductor light-emitting element 1 of Embodiment 1. In Figure 1 , (a) is a plan view of the semiconductor light-emitting element 1 of Embodiment 1, (b) is a vertical cross-sectional view of the semiconductor light-emitting element 1 taken along line A-A of (a), and (c) is a horizontal cross-sectional view of the semiconductor light-emitting element 1 taken along line B-B of (b). In addition, in Figure 1 , in order to easily understand the positional relationship of each component, shading is appropriately applied to the plan view of (a). The same applies to the following drawings.

[0056] As Figure 1 shown, the semiconductor light-emitting element 1 of Embodiment 1 has a semiconductor stack structure 10 and an n-side electrode 20 and a p-side electrode 30 provided on the n side of the semiconductor stack structure 10. In the present embodiment, the semiconductor light-emitting element 1 is a light-emitting diode (LED) chip having a single-sided electrode structure in which both the n-side electrode 20 and the p-side electrode 30 are formed on one side.

[0057] The semiconductor stack structure 10 has a substrate 11, an n-type semiconductor layer 12 (first conductivity type semiconductor layer), an active layer 13 serving as a light-emitting layer, and a p-type semiconductor layer 14 (second conductivity type semiconductor layer). The n-type semiconductor layer 12, the active layer 13, and the p-type semiconductor layer 14 are a semiconductor stack formed on the substrate 11. Specifically, the n-type semiconductor layer 12, the active layer 13, and the p-type semiconductor layer 14 are stacked on the substrate 11 in this order.

[0058] The n-type semiconductor layer 12, the active layer 13, and the p-type semiconductor layer 14 are made of a compound semiconductor. In the present embodiment, the n-type semiconductor layer 12, the active layer 13, and the p-type semiconductor layer 14 are made of a III-V group compound semiconductor such as GaN.

[0059] The n-side electrode 20 is the first electrode and is disposed on the n-type semiconductor layer 12. Specifically, the n-side electrode 20 is formed in an exposed region where the n-type semiconductor layer 12 is locally exposed by removing a part of the p-type semiconductor layer 14 and the active layer 13. On the other hand, the p-side electrode 30 is the second electrode and is disposed on the p-type semiconductor layer 14.

[0060] In the present embodiment, an insulating film 40 is formed on the semiconductor stack structure 10. Further, the n-side electrode 20 is formed on the n-type semiconductor layer 12 exposed from the opening of the insulating film 40, and the p-side electrode 30 is formed on the p-type semiconductor layer 14 exposed from the opening of the insulating film 40. In addition, the insulating film 40 is, for example, an oxide film made of SiO2 or the like.

[0061] The n-side electrode 20 has an n-side electrode layer 21 disposed on the n-type semiconductor layer 12 side and an n-side wiring layer 22 disposed on the n-side electrode layer 21. Specifically, the n-side electrode layer 21 is stacked on the n-type semiconductor layer 12, and the n-side wiring layer 22 is stacked on the n-side electrode layer 21. In addition, the n-type semiconductor layer 12 is in contact with the n-side electrode layer 21, and further, the n-side electrode layer 21 is in contact with the n-side wiring layer 22. In the present embodiment, the n-side electrode layer 21 and the n-side wiring layer 22 have the same shape in a top view.

[0062] The n-side electrode 20 has a power supply portion E1 and an extension portion E2 extending from the power supply portion E1. The power supply portion E1 is a portion of the n-side electrode 20 that is connected to the power supply terminal 100. That is, electrons are supplied to the power supply portion E1. The power supply terminal 100 is, for example, a bump or a wire. The extension portion E2 distributes the electrons supplied to the power supply portion E1 to the n-type semiconductor layer 12. In the present embodiment, in a direction orthogonal to the extending direction of the extension portion E2, the width of the power supply portion E1 is larger than the width of the extension portion E2. That is, the width of the extension portion E2 is smaller than the width of the power supply portion E1. Thus, the n-side electrode 20 has a portion with a width change. That is, the n-side electrode layer 21 and the n-side wiring layer 22 each have a portion with a width change.

[0063] The n-side electrode layer 21 has a first metal layer 21a disposed in the power supply portion E1 and a second metal layer 21b disposed on the extension portion E2 side with respect to the first metal layer 21a. In the present embodiment, the second metal layer 21b is directly connected to the first metal layer 21a. The first metal layer 21a and the second metal layer 21b are made of a metal material.

[0064] The n-side electrode layer 21 also has a third metal layer 21c in the extension portion E2. The third metal layer 21c is made of a metal material. The third metal layer 21c is located on the side of the second metal layer 21b opposite to the first metal layer 21a side. Thus, the second metal layer 21b is located between the first metal layer 21a and the third metal layer 21c in the extending direction of the extension portion E2. That is, the n-side electrode layer 21 is truncated into the first metal layer 21a and the third metal layer 21c in the extending direction of the extension portion E2, and the second metal layer 21b is provided in the truncated portion. In the present embodiment, the third metal layer 21c is directly connected to the second metal layer 21b.

[0065] The second metal layer 21b is disposed at least near the position where the width of the n-side electrode layer 21 changes in the extending direction of the extension portion E2. In the present embodiment, the second metal layer 21b straddles the position where the width of the n-side electrode layer 21 changes. That is, the second metal layer 21b is formed in both the power supply portion E1 and the extension portion E2.

[0066] The first metal layer 21a, the second metal layer 21b, and the third metal layer 21c are each in contact with the n-type semiconductor layer 12. Specifically, the first metal layer 21a, the second metal layer 21b, and the third metal layer 21c are ohmically connected to the n-type semiconductor layer 12.

[0067] The conductivity of the first metal layer 21a is higher than that of the second metal layer 21b. In addition, the conductivity of the third metal layer 21c is higher than that of the second metal layer 21b. Furthermore, the first metal layer 21a, the second metal layer 21b, and the third metal layer 21c are preferably made of a metal material having light reflectivity in order to reflect the light generated by the active layer 13. In the present embodiment, the first metal layer 21a and the third metal layer 21c are formed of the same material.

[0068] The first metal layer 21a and the third metal layer 21c can be made of, for example, aluminum (Al) or an alloy containing aluminum. In the present embodiment, the first metal layer 21a and the third metal layer 21c are made of aluminum.

[0069] The second metal layer 21b having a conductivity lower than that of the first metal layer 21a and the third metal layer 21c can be made of, for example, at least one metal material selected from titanium (Ti), tungsten (W), and chromium (Cr) or an alloy containing these at least one metal material. In the present embodiment, the second metal layer 21b is made of titanium.

[0070] In addition, the n-side wiring layer 22 laminated on the n-side electrode layer 21 is continuously disposed on the first metal layer 21a, the second metal layer 21b, and the third metal layer 21c of the n-side electrode layer 21. That is, the n-side wiring layer 22 is continuously formed in the power supply portion E1 and the extension portion E2.

[0071] At a portion of the n-side wiring layer 22 corresponding to the power supply unit E1, a power supply terminal 100 is connected. By supplying electrons from the power supply unit E1 of the n-side wiring layer 22, current flows from the power supply unit E1 of the n-side electrode 20 to the extension portion E2 and is distributed to the entire regions of the power supply unit E1 and the extension portion E2 of the n-side electrode 20.

[0072] The n-side wiring layer 22 is made of a metal material. The wiring resistance value of the n-side wiring layer 22 is preferably smaller than the wiring resistance value of the n-side electrode layer 21. That is, the n-side wiring layer 22 is preferably made of a metal material having a wiring resistance value lower than the average wiring resistance value of the n-side electrode layer 21 composed of the first metal layer 21a, the second metal layer 21b, and the third metal layer 21c. In particular, in the extension portion E2, the wiring resistance value of the n-side wiring layer 22 is preferably smaller than the wiring resistance value (average wiring resistance value) of the n-side electrode layer 21 in the extension portion E2. The n-side wiring layer 22 can be made of, for example, at least one metal material selected from copper (Cu), silver (Ag), and gold (Au), or an alloy containing at least one of these metal materials.

[0073] The p-side electrode 30 has a p-side electrode layer 31 disposed on the p-type semiconductor layer 14 side and a p-side wiring layer 32 disposed on the p-side electrode layer 31. In the present embodiment, the p-side electrode 30 has a p-side diffusion barrier layer 33 in order to suppress the mutual diffusion of the metal material constituting the p-side electrode layer 31 and the metal material constituting the p-side wiring layer 32. The p-side diffusion barrier layer 33 is disposed between the p-side electrode layer 31 and the p-side wiring layer 32.

[0074] The p-side electrode layer 31 is stacked on the p-type semiconductor layer 14, the p-side diffusion barrier layer 33 is stacked on the p-side electrode layer 31, and the p-side wiring layer 32 is stacked on the p-side diffusion barrier layer 33. In addition, the p-side electrode layer 31, the p-side diffusion barrier layer 33, and the p-side wiring layer 32 have the same shape in plan view.

[0075] The p-side electrode layer 31 is in contact with the p-type semiconductor layer 14. Specifically, the p-side electrode layer 31 is ohmically connected to the p-type semiconductor layer 14.

[0076] In the present embodiment, the p-side electrode layer 31 and the p-side wiring layer 32 are made of a metal material. The p-side electrode layer 31 is preferably made of a metal material having light reflectivity in order to reflect the light generated by the active layer 13.

[0077] The p-side electrode layer 31 can be made of, for example, at least one metal material selected from aluminum (Al), silver (Ag), and rhodium (Rh), or an alloy containing at least one of these metal materials. In the present embodiment, the p-side electrode layer 31 is made of silver.

[0078] Furthermore, the p-side wiring layer 32 is made of, for example, gold (Au), and the p-side diffusion barrier layer 33 is made of, for example, titanium (Ti).

[0079] In the semiconductor light emitting element 1 configured as described above, light is generated in the active layer 13 by applying a predetermined driving voltage to the n-side electrode 20 and the p-side electrode 30. The light generated in the active layer 13 is extracted from the substrate 11 side instead of the p-side electrode 30 side. In other words, the light extraction direction of the semiconductor light emitting element 1 is Figure 1 below the paper.

[0080] [Method for manufacturing semiconductor light-emitting element]

[0081] Next, use Figures 2A - 2H A method for manufacturing the semiconductor light emitting element 1 according to the first embodiment will be described. Figures 2A - 2H These are diagrams for explaining a method for manufacturing the semiconductor light emitting element 1 according to the first embodiment.

[0082] First, if Figure 2A As shown, a substrate 11 is prepared. In this embodiment, the substrate 11 is a light-transmitting substrate made of a semiconductor, and a wafer made of GaN (GaN substrate) is used.

[0083] Then, if Figure 2B As shown, an n-type semiconductor layer 12 , an active layer 13 , and a p-type semiconductor layer 14 are sequentially stacked on a substrate 11 by metal organic vapor phase epitaxy (MOVPE), thereby forming a semiconductor stacked structure 10 .

[0084] In this embodiment, n-type semiconductor layer 12 is an n-type nitride semiconductor layer (e.g., a GaN layer), active layer 13 is a nitride semiconductor light-emitting layer, and p-type semiconductor layer 14 is a p-type nitride semiconductor layer. The nitride semiconductor light-emitting layer constituting active layer 13 contains at least Ga and N, and optionally contains an appropriate amount of In to achieve the desired emission wavelength. In this embodiment, active layer 13 is an InGaN layer, and the In composition ratio is set to achieve a peak emission wavelength of 450 nm.

[0085] Then, if Figure 2C As shown, in the semiconductor stacked structure 10, the p-type semiconductor layer 14, the active layer 13, and a portion of the n-type semiconductor layer 12 are removed by dry etching, thereby exposing a portion of the n-type semiconductor layer 12 from the p-type semiconductor layer 14 and the active layer 13. Thus, an exposed region can be formed in a portion of the n-type semiconductor layer 12.

[0086] Then, if Figure 2DAs shown, an insulating film 40 is formed over the entire upper surface of a semiconductor laminate structure 10 including an exposed region of an n-type semiconductor layer 12. In the present embodiment, an oxide film made of SiO2 is formed as the insulating film 40.

[0087] Then, although not shown, a resist is coated over the insulating film 40, and an opening is formed in the resist at a position corresponding to the p-type semiconductor layer 14 by photolithography. The insulating film 40 within the opening of the resist is removed by etching with hydrofluoric acid. Thereby, the p-type semiconductor layer 14 is exposed.

[0088] Next, as Figure 2E shown, a p-side electrode 30 is formed within the exposed region of the p-type semiconductor layer 14. Specifically, using an EB evaporation method, a metal film that becomes a p-side electrode layer 31, a p-side diffusion barrier layer 33, and a p-side wiring layer 32 is sequentially formed to form a metal laminate film. The resist and the excess metal laminate film are removed by a resist lift-off method, thereby forming the p-side electrode 30 within the exposed region of the p-type semiconductor layer 14 after removing the insulating film 40. Thereby, a p-side electrode composed of a laminate structure of a p-side electrode layer 31, a p-side diffusion barrier layer 33, and a p-side wiring layer 32 can be formed.

[0089] In the present embodiment, an Ag layer (film thickness 0.2 μm) that becomes the p-side electrode layer 31, a Ti layer (film thickness 0.7 μm) that becomes the p-side diffusion barrier layer 33, and an Au layer (film thickness 1.0 μm) that becomes the p-side wiring layer 32 are sequentially formed from the side closer to the p-type semiconductor layer 14 toward the away direction. In addition, the film formation method of the metal film that becomes the p-side electrode layer 31, the p-side diffusion barrier layer 33, and the p-side wiring layer 32 is not limited to the EB evaporation method, and may also be a sputtering method.

[0090] In addition, the p-side electrode 30 may be formed to be separated from the insulating film 40. That is, the p-side electrode layer 31 and the insulating film 40 may also be separated. In this case, the p-type semiconductor layer 14 is exposed from between the p-side electrode 30 and the insulating film 40.

[0091] Then, although not shown, a resist is coated so as to cover the whole, and an opening is formed in the resist at a position corresponding to the n-type semiconductor layer 12 by photolithography. The insulating film 40 within the opening of the resist is removed by etching with hydrofluoric acid. Thereby, the n-type semiconductor layer 12 is exposed.

[0092] Next, as Figure 2FAs shown, a first metal layer 21a and a third metal layer 21c are formed in a part of the exposed area of the n-type semiconductor layer 12. Specifically, using an EB evaporation method, a first metal film that becomes the first metal layer 21a and the third metal layer 21c is formed, and the resist and the excess first metal film are removed by a resist stripping method, so that the separated first metal layer 21a and the third metal layer 21c are formed in the exposed area of the n-type semiconductor layer 12 after the insulating film 40 is removed. Thus, the first metal layer 21a and the third metal layer 21c made of the same material are formed in contact with the n-type semiconductor layer 12. In addition, the first metal layer 21a and the third metal layer 21c are not formed in the part after the first metal film is removed, and the n-type semiconductor layer 12 is exposed again.

[0093] The first metal layer 21a and the third metal layer 21c directly laminated on the n-type semiconductor layer 12 preferably are made of a metal material containing Al or the like because they function as an ohmic contact layer for the n-type semiconductor layer 12 and as a reflective layer for reflecting light. In the present embodiment, an Al layer (film thickness: 0.3 μm) is formed as the first metal layer 21a and the third metal layer 21c. In addition, the film forming method of the first metal film that becomes the first metal layer 21a and the third metal layer 21c is not limited to the EB evaporation method, and may also be a sputtering method.

[0094] In addition, the first metal layer 21a and the third metal layer 21c may be formed separated from the insulating film 40. That is, the first metal layer 21a and the third metal layer 21c may each be separated from the insulating film 40. In this case, the n-type semiconductor layer 12 is exposed from between the first metal layer 21a and the third metal layer 21c and the insulating film 40.

[0095] Next, as Figure 2G shown, a second metal layer 21b is formed in the exposed area of the n-type semiconductor layer 12 between the first metal layer 21a and the third metal layer 21c. Specifically, a resist is coated so as to cover the whole, an opening is formed in the resist at a position corresponding to the second metal layer 21b by photolithography, a second metal film that becomes the second metal layer 21b is formed using an EB evaporation method, and the resist and the excess second metal film are removed by a resist stripping method, so that the second metal layer 21b is formed in the exposed area where the n-type semiconductor layer 12 is exposed. Thus, the second metal layer 21b buried between the first metal layer 21a and the third metal layer 21c and in contact with the n-type semiconductor layer 12 is formed.

[0096] The second metal layer 21b directly stacked on the n-type semiconductor layer 12 functions as an ohmic contact layer for the n-type semiconductor layer 12 and also functions as a reflective layer for reflecting light. Further, the second metal layer 21b is preferably made of a metal material having higher electromigration tolerance than the first metal layer 21a and the third metal layer 21c and lower conductivity than the first metal layer 21a and the third metal layer 21c. Therefore, as the metal material constituting the second metal layer 21b, for example, Ti, W, Cr, etc. can be used. In the present embodiment, a Ti layer (film thickness 0.3 μm) is formed as the second metal layer 21b. In addition, the film formation method of the second metal film that becomes the second metal layer 21b is not limited to the EB evaporation method, and may also be the sputtering method.

[0097] In this way, by forming the second metal layer 21b between the first metal layer 21a and the third metal layer 21c, an n-side electrode layer 21 composed of the first metal layer 21a, the second metal layer 21b, and the third metal layer 21c can be formed.

[0098] Next, as shown in Figure 2H , an n-side wiring layer 22 is formed on the n-side electrode layer 21. Specifically, a resist is coated so as to cover the whole, openings are formed in the resist at positions corresponding to the n-side electrode layer 21 by photolithography, a third metal film that becomes the n-side wiring layer 22 is formed using the EB evaporation method, and the resist and the excess third metal film are removed by the resist stripping method, thereby forming the n-side wiring layer 22 on the n-side electrode layer 21. That is, within the range of the first metal layer 21a, the second metal layer 21b, and the third metal layer 21c, the n-side wiring layer 22 is formed on the first metal layer 21a, the second metal layer 21b, and the third metal layer 21c.

[0099] The n-side wiring layer 22 stacked on the n-side electrode layer 21 is preferably made of a metal material having higher electromigration tolerance than the n-side electrode layer 21 and a lower average wiring resistance value than the n-side electrode layer 21. Therefore, as the metal material constituting the n-side wiring layer 22, for example, Au, Cu, Ag, etc. can be used. In the present embodiment, an Au layer (film thickness 1.0 μm) is formed as the n-side wiring layer 22. In addition, the film formation method of the third metal film that becomes the n-side wiring layer 22 is not limited to the EB evaporation method, and may also be the sputtering method.

[0100] In this way, by forming the n-side wiring layer 22 on the n-side electrode layer 21, an n-side electrode 20 having a stacked structure of the n-side electrode layer 21 and the n-side wiring layer 22 can be formed.

[0101] As described above, the semiconductor light-emitting element 1 of the present embodiment shown in Figure 1 can be manufactured.

[0102] [Function and effect, etc.]

[0103] Next, use Figures 3 - 5 The effects of the semiconductor light emitting element 1 of this embodiment will be described.

[0104] Figure 3 (a) is a vertical cross-sectional view showing the structure of the n-side electrode 20X and its surroundings of the semiconductor light emitting element 1X of Comparative Example 1. Figure 3 (b) is Figure 3 (a) is a horizontal cross-sectional view of the n-side electrode layer 21X of the n-side electrode 20X taken along line BB. Figure 3 (c) is a graph showing the current density of the n-side electrode layer 21X of the n-side electrode 20X in the lateral direction (the extending direction of the extending portion).

[0105] Figure 4 (a) is a vertical cross-sectional view showing the structure of the n-side electrode 20Y and the surrounding area of the semiconductor light emitting element 1Y of Comparative Example 2. Figure 4 (b) is Figure 4 (a) is a horizontal cross-sectional view of the n-side electrode layer 21Y of the n-side electrode 20Y taken along line BB. Figure 4 (c) is a graph showing the current density of the n-side electrode layer 21Y of the n-side electrode 20Y in the lateral direction (the extending direction of the extending portion).

[0106] Figure 5 (a) is a vertical cross-sectional view showing the structure of the semiconductor light emitting element 1 in the first embodiment and its surroundings of the n-side electrode 20. Figure 5 (b) is Figure 5 (a) is a horizontal cross-sectional view of the n-side electrode layer 21 of the n-side electrode 20 taken along line BB. Figure 5 (c) is a graph showing the current density of the n-side electrode layer 21 of the n-side electrode 20 in the lateral direction (the extending direction of the extending portion).

[0107] in addition, Figure 3 (a) Figure 4 (a) and Figure 5 The arrows shown in (a) represent the flow of electrons.

[0108] like Figure 3 As shown in (a) and (b), the n-side electrode 20X in the semiconductor light-emitting element 1X of Comparative Example 1 has an n-side electrode layer 21X formed on the n-type semiconductor layer 12 on the substrate 11, and an n-side wiring layer 22X formed on the n-side electrode layer 21X.

[0109] In a plan view, the n-side electrode 20X has a portion with a varying width. Specifically, the n-side electrode 20X has a power supply portion E1 and an extension portion E2 that extends from the power supply portion E1 and has a width smaller than that of the power supply portion E1. That is, the n-side electrode 20X (the n-side electrode layer 21X and the n-side wiring layer 22X) has a portion with a varying width.

[0110] In the semiconductor light-emitting element 1X of Comparative Example 1 configured as described above, as Figure 3 shown in (c) of, in the portion with the varying width of the n-side electrode 20X, there is a case where the current density of the n-side electrode layer 21X locally increases and exceeds the critical value of electromigration (EM). As a result, electromigration may occur in the portion with the varying width of the n-side electrode 20X, and the n-side electrode layer 21X may deteriorate.

[0111] Therefore, in order to suppress electromigration in the portion with the varying width of the n-side electrode 20X, the structure of the semiconductor light-emitting element 1Y of Comparative Example 2 was studied.

[0112] As Figure 4 shown in (a) of and Figure 4 shown in (b) of, the n-side electrode 20Y in the semiconductor light-emitting element 1Y of Comparative Example 2, similar to the semiconductor light-emitting element 1X of Comparative Example 1, has an n-side electrode layer 21Y formed on the n-type semiconductor layer 12 on the substrate 11 and an n-side wiring layer 22Y formed on the n-side electrode layer 21Y.

[0113] In addition, in the semiconductor light-emitting element 1Y of Comparative Example 2, similar to the semiconductor light-emitting element 1X of Comparative Example 1, the width of the n-side electrode 20Y varies. Specifically, the n-side electrode 20Y has a power supply portion E1 and an extension portion E2 that extends from the power supply portion E1 and has a width smaller than that of the power supply portion E1. That is, the n-side electrode 20Y (the n-side electrode layer 21Y and the n-side wiring layer 22Y) has a portion with a varying width.

[0114] On the other hand, in the semiconductor light-emitting element 1Y of Comparative Example 2, different from the semiconductor light-emitting element 1X of Comparative Example 1, in the portion with the varying width of the n-side electrode 20Y, the n-side electrode layer 21Y is truncated, and an insulating layer 50Y is provided in the truncated portion of the n-side electrode layer 21Y. That is, the n-side electrode 20Y has two separated n-side electrode layers 21Y and an insulating layer 50Y buried between the two n-side electrode layers 21Y.

[0115] In the n-side electrode 20Y of the semiconductor light-emitting element 1Y of Comparative Example 2 configured as described above, as Figure 4 shown in (c) of, in the portion where the insulating layer 50Y is provided, the current density of the n-side electrode layer 21Y can be made zero. Thus, electromigration in the portion with the varying width of the n-side electrode 20Y can be suppressed.

[0116] However, in the semiconductor light-emitting device 1Y of Comparative Example 2 shown below, as shown in Figure 4 (a) of [], the ohmic contact area between the n-side electrode 20Y and the n-type semiconductor layer 12 decreases, and the driving voltage increases. Figure 4 On the other hand, in the semiconductor light-emitting device 1 of the present embodiment, as shown in

[0117] (a) and (b) of [], the n-side electrode 20 has an n-side electrode layer 21 and an n-side wiring layer 22 disposed above the n-side electrode layer 21. The n-side electrode layer 21 has a first metal layer 21a disposed in the power supply portion E1, and a second metal layer 21b disposed on the side of the extension portion E2 with respect to the first metal layer 21a and having a lower conductivity than the first metal layer 21a. Figure 5 In the n-side electrode 20 configured as described above, as shown in

[0118] (a) of [], in the portion where the second metal layer 21b is provided, a part of the lateral current flowing in the n-side electrode layer 21 can be bypassed to the n-side wiring layer 22. Thus, as shown in Figure 5 (c) of [], in the portion where the second metal layer 21b is provided, the lateral current density of the n-side electrode layer 21 can be made smaller. Therefore, in the portion where the width of the n-side electrode 20 changes, the portion where the current density exceeds the critical value of electromigration can be eliminated. In addition, by using the second metal layer 21b having conductivity instead of an insulating layer, a portion where the current density is zero is not generated in the n-side electrode layer 21. Therefore, in the semiconductor light-emitting device 1 of the present embodiment, compared with the semiconductor light-emitting device 1Y of Comparative Example 2 shown in Figure 5 (), the ohmic contact area between the n-side electrode 20 and the n-type semiconductor layer 12 can be increased. Thus, an increase in the driving voltage can be suppressed. Figure 4 As described above, according to the semiconductor light-emitting device 1 of the present embodiment, even if the n-side electrode 20 has a portion where the width changes, an increase in the driving voltage can be suppressed and electromigration can be suppressed.

[0119] In addition, in the semiconductor light-emitting device 1 of the present embodiment, the first metal layer 21a and the third metal layer 21c are made of aluminum having a high light reflectivity, and only the second metal layer 21b having a low reflectivity is made of titanium in the portion where the current density becomes high. Thereby, a decrease in the average reflectivity of the n-side electrode layer 22 can be suppressed, and thus a decrease in the light extraction efficiency can be suppressed.

[0120] Furthermore, in the semiconductor light-emitting device 1 of the present embodiment, in the extension portion E2 of the n-side electrode 20, the wiring resistance value of the n-side wiring layer 22 is smaller than the wiring resistance value (average wiring resistance value) of the n-side electrode layer 21 in the extension portion E2.

[0121]

[0122] ​With this structure, when the n-side electrode layer 21 and the n-side wiring layer 22 are set up as a parallel circuit, compared with the n-side electrode layer 21, electrons supplied from the power supply unit E1 to the n-side electrode 20 toward the extension part E2 can flow through the n-side wiring layer 22 more easily. That is, the amount of current bypass flowing into the n-side wiring layer 22 can be increased. Therefore, electromigration can be suppressed more effectively.

[0123] In addition, in the case where the width of the n-side electrode 20 changes abruptly as in the semiconductor light-emitting element 1 of the present embodiment, the position where the width of the n-side electrode 20 changes is clear. While in the case where the width of the n-side electrode 20 changes smoothly as shown in Figure 6 , the position where the width of the n-side electrode 20 changes is the position where the differential value (dL / dx) of the width L of the n-side electrode layer 21 corresponding to the position x in the direction from the power supply unit E1 to the extension part E2 is extremely small.

[0124] On the other hand, as shown in (b) of Figure 5 , in the case where the width of the n-side electrode 20 changes abruptly, the differential value (dL / dx) of the width L of the n-side electrode layer 21 corresponding to the position x in the direction from the power supply unit E1 to the extension part E2 is discontinuous.

[0125] Therefore, the second metal layer 21b of the n-side electrode layer 21 in the n-side electrode 20 is preferably arranged in the area including the position where the differential value of the width L of the n-side electrode layer 21 corresponding to the position x in the direction from the power supply unit E1 to the extension part E2 is extremely small, or the area including the position where the above differential value is discontinuous.

[0126] In addition, in the case where at least a part of the second metal layer 21b of the n-side electrode layer 21 in the n-side electrode 20 is arranged in the power supply unit E1 as shown in (a) to (c) of Figure 7 , in the area of the power supply unit E1 where the second metal layer 21b is arranged, the maximum width W of the second metal layer 21b 21b is preferably the maximum width W of the power supply unit E1 E1 below and larger than the maximum width W of the extension part E2 E2 .

[0127] In addition, in the case where at least a part of the second metal layer 21b of the n-side electrode layer 21 in the n-side electrode 20 is arranged in the extension part E2 as shown in (a) to (c) of Figure 8 , in the area of the extension part E2 where the second metal layer 21b is arranged, the maximum width W of the second metal layer 21b 21b is preferably the maximum width W of the extension part E2 E2 below and smaller than the maximum width W of the power supply unit E1 E1 .

[0128] Here, as Figure 3 shown, when the width of the n-side electrode 20X changes discontinuously, the current density is highest on the extension E2 side of the width change position. Therefore, as Figure 5 shown, by providing the second metal layer 21b in the region including the width change position, in the region of the n-side electrode 20 where the second metal layer 21b is disposed, a part of the current bypasses to the upper n-side wiring layer 22, so that the peak value of the current density in the lateral direction (extension direction) in the n-side electrode 20 can be reduced. On the contrary, when the second metal layer 21b is disposed on the extension E2 side at a position immediately adjacent to the extension of the width change position (for example, at a distance within 10 μm from the width change position) without including the width change position, regardless of its area, the n-side electrode 20 cannot reduce the lateral current density near the width change position to a desired value. In addition, at a position on the opposite side of the width change position in the extension direction, even if the second metal layer 21b is not disposed, the width of the n-side electrode 20 becomes wider and the current density decreases, so it is not necessary to dispose the second metal layer 21b farther than the position on the extension direction side of the width change position.

[0129] Figure 9 is a graph showing the maximum current density of the n-side electrode at each measurement position of the extension E2 when the semiconductor light-emitting element 1 with a side length of 0.5 mm is driven by 1 A. The n-side electrode is as Figure 1 (a) shown, the power supply part E1 is disposed along the outer periphery of the semiconductor light-emitting element 1, and the extension E2 is disposed so as to extend from the power supply part E1 toward the central part of the semiconductor light-emitting element 1. The n-side electrode is made of aluminum with a film thickness of 1.2 μm, the width of the extension E2 is set to 50 μm, the measurement position in the extension E2 is changed, and the maximum current density at each location is obtained. As Figure 9 shown, the maximum lateral current density in the range of a distance of 100 μm from the width change position exceeds the value (1×10 5 [A / cm 2 ) at which aluminum electromigration is considered likely to occur. Thus, by disposing the second metal layer 21b made of titanium from the width change position to a position 100 μm in the extension direction, the maximum lateral current density can be made below the value at which electromigration occurs. In actual use, as long as the maximum current density in the range where electromigration does not occur is suppressed, the configuration range of the second metal layer 21b can also be appropriately set according to conditions such as the structure of the semiconductor light-emitting element 1, the material constituting the n-side electrode 20, or the width of the extension E2.

[0130] In addition, here, as Figure 6As shown, when the width of the n-side electrode 20 changes smoothly, the position where the width changes is defined as the position where the differential value (dL / dx) of the width L of the n-side electrode layer 21 corresponding to the position x in the direction from the power supply unit E1 toward the extension unit E2 is extremely small. Here, when the width of the extension unit E2 is a constant value, the current density is the highest at the place closest to the power supply unit E1 side in the region with a constant width. Therefore, by providing the second metal layer 21b in the region including the portion with the highest current density on the extension unit E2 side compared to the width change position based on the differential, the peak current density in the lateral direction can be reduced. In this case, it is not necessary to always arrange the second metal layer 21b at the width change position as in the case where the width of the n-side electrode 20 changes discontinuously. In addition, at the width change position, compared with the position where the maximum current density occurs, the electrode width becomes wider, and the current density decreases due to the effect of the widened electrode width. Therefore, at the position on the opposite side of the extension direction compared to the width change position, it is not necessary to arrange the second metal layer 21b much farther than at the position on the extension direction side compared to the width change position. In actual use, since it is only necessary to suppress the maximum current density within the range where electromigration does not occur, the arrangement range of the second metal layer 21b can also be appropriately set according to conditions such as the structure of the semiconductor light-emitting element 1, the material constituting the n-side electrode 20, and the width of the extension unit E2.

[0131] In addition, when the width of the extension unit E2 gradually changes, the position where the current density becomes high changes depending on the shape.

[0132] Based on the above, the second metal layer 21b is preferably arranged within 100 μm from the width change position toward the extension direction.

[0133] Here, as shown in (a) and (b) of Figure 10 , the second metal layer 21b can be provided on both the power supply unit E1 and the extension unit E2. In this case, the second metal layer 21b can be arranged in a region exceeding 100 μm in the extension direction with the position x0 where the width of the n-side electrode layer 21 changes as a reference as shown in (a) of Figure 10 , or can be arranged only in a region within 100 μm in the extension direction with the position x0 where the width of the n-side electrode layer 21 changes as a reference as shown in (b) of Figure 10 .

[0134] In addition, as shown in (c) and (d) of Figure 10 , the second metal layer 21b can also be provided only on the extension unit E2. In this case, the second metal layer 21b can be arranged only in a region within 100 μm in the extension direction with the position x0 where the width of the n-side electrode layer 21 changes as a reference as shown in (c) of Figure 10 , or can be arranged as shown in (d) of Figure 10As shown in (d), a region exceeding 100 μm is provided in the extending direction with the position x0 where the width of the n-side electrode layer 21 changes as a reference.

[0135] (Modification 1 of Embodiment 1)

[0136] Next, Figure 11 The semiconductor light-emitting element 1A of Modification 1 of Embodiment 1 will be described. In Figure 11 , (a) is a plan view of the semiconductor light-emitting element 1A of Modification 1 of Embodiment 1, (b) is a vertical cross-sectional view of the semiconductor light-emitting element 1A taken along line A-A of (a), and (c) is a horizontal cross-sectional view of the semiconductor light-emitting element 1A taken along line B-B of (b).

[0137] The semiconductor light-emitting element 1A of this modification has a different structure of the n-side electrode 20A compared to the semiconductor light-emitting element 1 of the above Embodiment 1.

[0138] Specifically, as Figure 11 shown in (b) and (c), the n-side electrode 20A of the semiconductor light-emitting element 1A of this modification, similar to the n-side electrode 20 of the semiconductor light-emitting element 1 of the above Embodiment 1, has an n-side electrode layer 21A and an n-side wiring layer 22A. However, the n-side electrode layer 21A of the n-side electrode 20A in the semiconductor light-emitting element 1A of this modification further has a fourth metal layer 21d and a fifth metal layer 21e in addition to the first metal layer 21a, the second metal layer 21b, and the third metal layer 21c.

[0139] In this modification as well, the n-side electrode 20A has a power supply portion E1 and an extending portion E2. The fourth metal layer 21d is located on the side opposite to the second metal layer 21b side of the third metal layer 21c in the extending portion E2. The fourth metal layer 21d is directly connected to the third metal layer 21c. In this modification, the fourth metal layer 21d is formed of the same material as the second metal layer 21b. Specifically, the fourth metal layer 21d is made of titanium, similar to the second metal layer 21b.

[0140] Furthermore, the fifth metal layer 21e is located on the side opposite to the third metal layer 21c side of the fourth metal layer 21d in the extending portion E2. The fifth metal layer 21e is directly connected to the fourth metal layer 21d. In this modification, the fifth metal layer 21e is formed of the same material as the first metal layer 21a. Specifically, the fifth metal layer 21e is made of aluminum, similar to the first metal layer 21a and the third metal layer 21c.

[0141] The fourth metal layer 21d and the fifth metal layer 21e are in contact with the n-type semiconductor layer 12, similar to the first metal layer 21a, the second metal layer 21b, and the third metal layer 21c. Specifically, the fourth metal layer 21d and the fifth metal layer 21e are ohmically connected to the n-type semiconductor layer 12.

[0142] In addition, in the n-side electrode 20A of this modified example, there are multiple positions where the width changes (width change positions). Therefore, multiple width change positions are provided in each of the n-side electrode layer 21A and the n-side wiring layer 22A.

[0143] Specifically, in the n-side electrode 20A of this modified example, similar to the n-side electrode 20 of the above-described Embodiment 1, the boundary portion between the power supply portion E1 and the extension portion E2 becomes a width change position, and a width change position is provided in a part of the extension portion E2. That is, the width of the n-side electrode 20A of this modified example changes in two stages, and there are two width change positions in the n-side electrode 20A.

[0144] In this modified example, in the extension portion E2 of the n-side electrode 20A, the width changes in a stepped manner such that the width becomes narrower toward the front end in the extending direction of the extension portion E2. And the fourth metal layer 21d of the n-side electrode layer 21A is provided near this width change position of the extension portion E2.

[0145] As described above, according to the semiconductor light-emitting element 1A of this modified example, similar to the semiconductor light-emitting element 1 of the above-described Embodiment 1, the n-side electrode 20A has an n-side electrode layer 21A and an n-side wiring layer 22A disposed above the n-side electrode layer 21A. The n-side electrode layer 21A has a first metal layer 21a disposed in the power supply portion E1, and a second metal layer 21b disposed on the side of the extension portion E2 with respect to the first metal layer 21a and having a lower conductivity than the first metal layer 21a.

[0146] With this structure, even if there is a portion where the width changes in the n-side electrode 20A, an increase in the driving voltage can be suppressed and electromigration can be suppressed. In addition, a decrease in the light extraction efficiency can be suppressed.

[0147] And, in the n-side electrode 20A of the semiconductor light-emitting element 1A of this modified example, there are multiple width change positions with respect to the current path direction, and a metal layer having a lower conductivity than the first metal layer 21a is provided at each width change position of the n-side electrode layer 21A. Specifically, the second metal layer 21b is provided at one of the two width change positions of the n-side electrode layer 21A, and the fourth metal layer 21d is provided at the other of the two width change positions of the n-side electrode layer 21A. With this structure, even if there are multiple width change positions in the n-side electrode 20A and there are multiple portions where the current density becomes high, an increase in the driving voltage can be suppressed and electromigration can be effectively suppressed.

[0148] Further, in the extension portion E2 of the n-side electrode 20A in this modified example, a portion with a varying width is provided as a portion where the current density of the n-side electrode layer 21A increases, and a fourth metal layer 21d is provided in the portion with the varying width in the extension portion E2 of the n-side electrode layer 21A, but it is not limited thereto. For example, the portion where the current density of the n-side electrode layer 21A increases may also be a bent portion provided in the extension portion E2 of the n-side electrode 20A. In the bent portion, the power lines become denser and the current density becomes higher. When a bent portion is provided in the extension portion E2 of the n-side electrode layer 21A, it is only necessary to provide the fourth metal layer 21d near the bent portion.

[0149] In addition, in the semiconductor light-emitting element 1A of this modified example, a width change position exists in a part of the extension portion E2 of the n-side electrode layer 21A of the n-side electrode 20A, but it is not limited thereto. It may also be as Figure 12 shown, where there is no width change position in the extension portion E2 of the n-side electrode layer 21A.

[0150] (Modified Example 2 of Embodiment 1)

[0151] Next, Figure 13 the semiconductor light-emitting element 1B of Modified Example 2 of Embodiment 1 will be described. In Figure 13 , (a) is a plan view of the semiconductor light-emitting element 1B of Modified Example 2 of Embodiment 1, (b) is a vertical cross-sectional view of the semiconductor light-emitting element 1B taken along line A-A of (a), and (c) is a horizontal cross-sectional view of the semiconductor light-emitting element 1B taken along line B-B of (b).

[0152] The semiconductor light-emitting element 1B of this modified example has a different shape of the n-side electrode 20B compared to the semiconductor light-emitting element 1 of the above-described Embodiment 1.

[0153] Specifically, as shown in (c) of Figure 13 , the extension portion E2 of the n-side electrode 20B of this modified example has a portion on the side opposite to the power supply portion E1 side with a width smaller than that on the power supply portion E1 side. Therefore, the n-side electrode layer 21B and the n-side wiring layer 22B in the extension portion E2 each have a portion on the side opposite to the power supply portion E1 side with a width smaller than that on the power supply portion E1 side.

[0154] In this modified example, the extension portion E2 of the n-side electrode 20B has a shape in which the width gradually narrows toward the front end in the extending direction of the extension portion E2. Specifically, the extension portion E2 of the n-side electrode 20B is a tapered shape that tapers toward the front end in the extending direction of the extension portion E2. Therefore, the n-side electrode layer 21B and the n-side wiring layer 22B are each in a tapered shape that tapers toward the front end in the extending direction of the extension portion E2. More specifically, in the portion of the extension portion E2 of the second metal layer 21b and the third metal layer 21c, the n-side electrode layer 21B forms a tapered shape of a substantially isosceles triangle.

[0155] As described above, in the semiconductor light-emitting element 1B of this modified example, similar to the semiconductor light-emitting element 1 of the above-described Embodiment 1, the n-side electrode 20B includes an n-side electrode layer 21B and an n-side wiring layer 22B disposed on the n-side electrode layer 21B. The n-side electrode layer 21B includes a first metal layer 21a disposed in the power supply portion E1, and a second metal layer 21b disposed on the side of the extension portion E2 with respect to the first metal layer 21a and having a lower conductivity than the first metal layer 21a.

[0156] Accordingly, even if a portion with a width change is provided in the n-side electrode 20B, an increase in the driving voltage can be suppressed and electromigration can be suppressed. In addition, a decrease in the light extraction efficiency can be suppressed.

[0157] Moreover, in the semiconductor light-emitting element 1B of this modified example, the extension portion E2 of the n-side electrode 20B has a portion on the side opposite to the power supply portion E1 side with a width smaller than the width on the power supply portion E1 side.

[0158] With this structure, the area of the n-side electrode 20B can be reduced, so the area of the p-side electrode 30 (i.e., the light-emitting area) can be increased. Thereby, the light output of the semiconductor light-emitting element 1B can be increased. In this case, in the extension portion E2 of the n-side electrode 20B, the amount of current becomes smaller as it approaches the front end. Therefore, even if the width of the side of the extension portion E2 opposite to the power supply portion E1 side (front end side) is reduced as in this modified example, the current density does not increase much, so the occurrence of electromigration can be suppressed. That is, preferably, the front end of the extension portion E2 of the n-side electrode 20B is tapered to such an extent that the current density does not exceed the critical value of electromigration, thereby reducing the area of the n-side electrode 20 and increasing the area of the p-side electrode 30. Thus, according to the semiconductor light-emitting element 1B of this modified example, the suppression effect of electromigration can be maintained and the light output of the semiconductor light-emitting element 1B can be increased.

[0159] In addition, in Figure 13 the illustrated semiconductor light-emitting element 1B, the entire extension portion E2 has a tapered shape with a tapered front end, but it is not limited thereto. For example, as Figure 14 illustrated, a part of the extension portion E2 (in Figure 14The third metal layer 21c) in the middle is tapered with a pointed tip.

[0160] (Modification Example 3 of Embodiment 1)

[0161] Next, use Figure 15 The semiconductor light-emitting element 1C of Modification Example 3 of Embodiment 1 will be described. In Figure 15 , (a) is a plan view of the semiconductor light-emitting element 1C of Modification Example 3 of Embodiment 1, (b) is a vertical cross-sectional view of the semiconductor light-emitting element 1C taken along line A-A of (a), and (c) is a horizontal cross-sectional view of the semiconductor light-emitting element 1C taken along line B-B of (b).

[0162] The semiconductor light-emitting element 1C of this modification has a different structure of the n-side electrode 20C compared to the semiconductor light-emitting element 1 of the above Embodiment 1.

[0163] Specifically, as shown in (a) and (c) of Figure 15 , the n-side electrode 20C of the semiconductor light-emitting element 1C of this modification is the same as the n-side electrode 20 of the semiconductor light-emitting element 1 of the above Embodiment 1, having an n-side electrode layer 21C and an n-side wiring layer 22C. However, the n-side electrode layer 21C of the n-side electrode 20C in the semiconductor light-emitting element 1C of this modification further has a fourth metal layer 21d and a fifth metal layer 21e in addition to the first metal layer 21a, the second metal layer 21b, and the third metal layer 21c.

[0164] In addition, in this modification, the n-side electrode 20C also has a power supply portion E1 and an extension portion E2. However, the n-side electrode 20C of this modification has a branch portion DP on the side opposite to the power supply portion E1 side in the extension portion E2. Specifically, in the extension portion E2, it branches into two branch electrodes by the branch portion DP. By providing the branch portion DP in the n-side electrode 20C, it is possible to efficiently supply power to the entire semiconductor light-emitting element 1C with a smaller electrode area. Also, in this modification, the width of the electrode (branch electrode) after branching by the branch portion DP is smaller than the width of the electrode where the branching by the branch portion DP occurs.

[0165] The fourth metal layer 21d is located on the side opposite to the second metal layer 21b side of the third metal layer 21c in the extension portion E2. The fourth metal layer 21d is disposed in the branch portion DP. In addition, the fourth metal layer 21d is directly connected to the third metal layer 21c. In this modification, the fourth metal layer 21d is formed of the same material as the second metal layer 21b. Specifically, the fourth metal layer 21d is made of titanium, the same as the second metal layer 21b.

[0166] In addition, in the extension portion E2, the fifth metal layer 21e is located on the side of the fourth metal layer 21d opposite to the side of the third metal layer 21c. The fifth metal layer 21e is disposed on the branch electrode after branching at the branch portion DP. The fifth metal layer 21e is directly connected to the fourth metal layer 21d. In this modification, the fifth metal layer 21e is formed of the same material as the first metal layer 21a. Specifically, the fifth metal layer 21e, like the first metal layer 21a and the third metal layer 21c, is made of aluminum.

[0167] Similar to the first metal layer 21a, the second metal layer 21b, and the third metal layer 21c, the fourth metal layer 21d and the fifth metal layer 21e are in contact with the n-type semiconductor layer 12. Specifically, the fourth metal layer 21d and the fifth metal layer 21e are ohmic-connected to the n-type semiconductor layer 12.

[0168] As described above, similar to the semiconductor light-emitting element 1 of the above-described Embodiment 1, in the semiconductor light-emitting element 1C according to this modification, the n-side electrode 20C has an n-side electrode layer 21C and an n-side wiring layer 22C disposed on the n-side electrode layer 21C. The n-side electrode layer 21C has a first metal layer 21a disposed in the power supply portion E1, and a second metal layer 21b disposed on the side of the extension portion E2 with respect to the first metal layer 21a and having a lower conductivity than the first metal layer 21a.

[0169] With this structure, even if there is a portion with a width change in the n-side electrode 20C, an increase in the driving voltage can be suppressed and electromigration can be suppressed. In addition, a decrease in the light extraction efficiency can be suppressed.

[0170] Moreover, the n-side electrode 20C of the semiconductor light-emitting element 1C according to this modification has a branch portion DP on the side opposite to the power supply portion E1 side in the extension portion E2. At the portion of the n-side electrode 20C where the branch portion DP is provided, the current density of the n-side electrode layer 21C becomes large. For example, if the sum of the widths of a plurality of electrodes (branch electrodes) after branching at the branch portion DP is smaller than the width of the electrode before branching, the current density at the branch portion DP becomes large.

[0171] Therefore, in the n-side electrode 20C of the semiconductor light-emitting element 1C according to this modification, the fourth metal layer 21d is disposed at the branch portion DP of the n-side electrode layer 21C.

[0172] With this structure, even if there is a branch portion DP in the n-side electrode 20C, an increase in the driving voltage can be suppressed and electromigration can be effectively suppressed.

[0173] In addition, the extension portion E2 of the n-side electrode 20C in this modification is provided with a branch portion DP that branches in a Y shape, but is not limited thereto. For example, the branch portion DP may be provided in the extension portion E2 of the n-side electrode 20C in a T-shaped branching manner. In this case, even if the sum of the electrode widths before and after branching is equal, since the branch portion is a bent portion, the power lines become dense in the branch portion and the current density increases. Therefore, even if the branch portion DP is provided in the extension portion E2 of the n-side electrode 20C in a T-shaped branching manner, electromigration can be effectively suppressed by providing the fourth metal layer 21d in the branch portion DP of the n-side electrode layer 21C.

[0174] In addition, preferably, at least a part of the fourth metal layer 21d provided in the branch portion DP exists within a region of ±100 μm in the branch direction with respect to the center of the branch portion DP.

[0175] In addition, in the semiconductor light-emitting element 1C of this modification, the fourth metal layer 21d is provided in the branch portion DP of the n-side electrode layer 21C, but is not limited thereto. For example, in the case where, as shown in Figure 16 the n-side electrode layer 21C does not have the fourth metal layer 21d and the fifth metal layer 21e and has only the first metal layer 21a, the second metal layer 21b, and the third metal layer 21c, the second metal layer 21b may be provided in the branch portion DP of the n-side electrode layer 21C.

[0176] In addition, in the n-side electrode 20C of the semiconductor light-emitting element 1C of this modification, one extension portion E2 extends from the power supply portion E1, but is not limited thereto. For example, as shown in Figure 17 a plurality (four in Figure 17 ) of extension portions E2 may extend from the power supply portion E1. In this case, preferably, the fourth metal layer 21d is provided in the branch portion DP of each of the plurality of extension portions E2 in the n-side electrode layer 21C. In addition, the fourth metal layer 21d may not be provided in all the branch portions DP of the plurality of extension portions E2. In this case, preferably, at least a part of the second metal layer 21b exists within a region of ±100 μm in the branch direction with respect to the center of the branch portion DP.

[0177] (Modification 4 of Embodiment 1)

[0178] Next, the semiconductor light-emitting element 1D of Modification 4 of Embodiment 1 will be described using Figure 18 . In Figure 18 , (a) is a plan view of the semiconductor light-emitting element 1D of Modification 4 of Embodiment 1, (b) is a vertical cross-sectional view of the semiconductor light-emitting element 1D taken along line A-A of (a), and (c) is a horizontal cross-sectional view of the semiconductor light-emitting element 1D taken along line B-B of (b).

[0179] In the semiconductor light-emitting element 1D of this modification example, the structure of the n-side electrode 20D is different from that of the semiconductor light-emitting element 1 of the above-described Embodiment 1.

[0180] Specifically, as Figure 18 shown in (b) of, in the n-side electrode 20D of the semiconductor light-emitting element 1D of this modification example, an n-side diffusion barrier layer 23 is further provided in the n-side electrode 20 of the semiconductor light-emitting element 1 of the above-described Embodiment 1. That is, the n-side electrode 20D in this modification example has an n-side diffusion barrier layer 23 in addition to the n-side electrode layer 21 and the n-side wiring layer 22.

[0181] The n-side diffusion barrier layer 23 is disposed between the n-side electrode layer 21 and the n-side wiring layer 22. In this modification example, the n-side diffusion barrier layer 23 is in contact with the n-side electrode layer 21 and the n-side wiring layer 22, respectively, but is not limited thereto. The n-side diffusion barrier layer 23 suppresses the mutual diffusion of the metal material constituting the n-side electrode layer 21 and the metal material constituting the n-side wiring layer 22. For example, the n-side diffusion barrier layer 23 suppresses the mutual diffusion of aluminum contained in the n-side electrode layer 21 and gold contained in the n-side wiring layer 22.

[0182] The n-side diffusion barrier layer 23 can be formed of at least one metal material selected from titanium (Ti), molybdenum (Mo), chromium (Cr), platinum (Pt), nickel (Ni), and tungsten (W), or an alloy containing these at least one metal material.

[0183] As an example, when the first metal layer 21a and the third metal layer 21c of the n-side electrode layer 21 are Al layers (film thickness: 0.3 μm), the second metal layer 21b of the n-side electrode layer 21 is a Ti layer (film thickness: 0.3 μm), and the n-side wiring layer 22 is an Au layer (film thickness: 1.0 μm), the n-side diffusion barrier layer 23 is a Mo layer (film thickness: 0.375 μm) formed of molybdenum.

[0184] As described above, according to the semiconductor light-emitting element 1D of this modification example, similar to the semiconductor light-emitting element 1 of the above-described Embodiment 1, the n-side electrode 20D has an n-side electrode layer 21 and an n-side wiring layer 22 disposed on the n-side electrode layer 21. The n-side electrode layer 21 has a first metal layer 21a disposed in the power supply portion E1, and a second metal layer 21b disposed on the side of the extension portion E2 with respect to the first metal layer 21a and having a lower conductivity than the first metal layer 21a.

[0185] With this structure, even when there is a portion with a width change in the n-side electrode 20D, an increase in the driving voltage can be suppressed and electromigration can be suppressed. In addition, a decrease in the light extraction efficiency can be suppressed.

[0186] In addition, the n-side electrode 20D in the semiconductor light-emitting element 1D of this modification example has an n-side diffusion barrier layer 23 between the n-side electrode layer 21 and the n-side wiring layer 22.

[0187] With this structure, the mutual diffusion of the metal material constituting the n-side electrode layer 21 and the metal material constituting the n-side wiring layer 22 can be suppressed by the n-side diffusion barrier layer 23. Therefore, a semiconductor light-emitting element 1D with excellent long-term reliability can be realized.

[0188] In addition, in the semiconductor light-emitting element 1D of this modification example, the n-side diffusion barrier layer 23 and the n-side electrode layer 21 are made of different materials, but this is not limited thereto. For example, the n-side diffusion barrier layer 23 may also be made of the same material as the second metal layer 21b of the n-side electrode layer 21. In this case, the second metal layer 21b of the n-side electrode layer 21 and the n-side diffusion barrier layer 23 can be integrated, and like Figure 19 the n-side electrode 20E of the semiconductor light-emitting element 1E shown, the second metal layer 21b of the n-side electrode layer 21E functions as the n-side diffusion barrier layer. In Figure 19 the semiconductor light-emitting element 1E shown, the second metal layer 21b of the n-side electrode layer 21E is a Ti layer.

[0189] Figure 19 The n-side electrode 20E of the semiconductor light-emitting element 1E shown can be formed by separately depositing a Ti layer that becomes the second metal layer 21b of the n-side electrode layer 21E and a Ti layer that becomes the n-side diffusion barrier layer on the n-side electrode layer 21E. For example, the first metal layer 21a, the third metal layer 21c (e.g., an Al layer), and the second metal layer 21b (e.g., a Ti layer) are deposited to form the n-side electrode layer 21E, and then, on the n-side electrode layer 21E, an n-side diffusion barrier layer (e.g., a Ti layer) of the same material as the second metal layer 21b is deposited by EB evaporation or sputtering, etc., and formed into a specified shape by photolithography.

[0190] In addition, the Ti layer that becomes the second metal layer 21b of the n-side electrode layer 21E and the Ti layer that becomes the n-side diffusion barrier layer on the n-side electrode layer 21E may be deposited simultaneously instead of separately. For example, the first metal layer 21a and the third metal layer 21c (e.g., an Al layer) are deposited in an island shape, and then, the island-shaped first metal layer 21a and the third metal layer 21c are covered and a second metal layer 21b (e.g., a Ti layer) that becomes the n-side diffusion barrier layer is deposited by EB evaporation or sputtering, etc., and formed into a specified shape by photolithography. Thus, Figure 20The n-side electrode 20F of the semiconductor light-emitting element 1F as shown. That is, the second metal layer 21b of the n-side electrode layer 21F and the n-side wiring layer 22, which also function as the n-side diffusion barrier layer, are recessed between the separated first metal layer 21a and third metal layer 21c. Thus, by integrally forming the second metal layer 21b of the n-side electrode layer 21F and the diffusion barrier layer simultaneously, the manufacturing process can be reduced.

[0191] (Modification 5 of Embodiment 1)

[0192] Next, use Figure 21 The semiconductor light-emitting element 1G of Modification 5 of Embodiment 1 will be described. In Figure 21 , (a) is a plan view of the semiconductor light-emitting element 1G of Modification 5 of Embodiment 1, (b) is a vertical cross-sectional view of the semiconductor light-emitting element 1G taken along line A-A of (a), (c) is a horizontal cross-sectional view of the semiconductor light-emitting element 1G taken along line B-B of (b), (d) is a vertical cross-sectional view of the semiconductor light-emitting element 1G taken along line C-C of (a), and (e) is a horizontal cross-sectional view of the semiconductor light-emitting element 1G taken along line D-D of (d).

[0193] The structure of the p-side electrode 30G of the semiconductor light-emitting element 1G of this modification is different from that of the semiconductor light-emitting element 1 of Embodiment 1 described above.

[0194] Specifically, the p-side electrode 30 of the semiconductor light-emitting element 1 of Embodiment 1 described above is disposed on the p-type GaN layer. In contrast, as shown in (a), (d), and (e) of Figure 21 , the p-side electrode 30G of the semiconductor light-emitting element 1G of this modification is disposed on the oxide semiconductor layer 34.

[0195] The oxide semiconductor layer 34 is disposed on the p-type semiconductor layer 14. In this modification, the oxide semiconductor layer 34 is in contact with the p-type semiconductor layer 14.

[0196] The oxide semiconductor layer 34 is composed of a compound semiconductor. As the oxide semiconductor layer 34, for example, a transparent conductive film made of indium tin oxide (ITO; Indium Tin Oxide), indium zinc oxide (IZO; Indium Zinc Oxide), zinc oxide (ZnO; Zinc Oxide), or InGaZnO x (IGZO) and other transparent metal oxides can be used. Thus, the light generated by the active layer 13 can pass through the oxide semiconductor layer 34 and be extracted to the outside. That is, the light generated by the active layer 13 is extracted from the p-side electrode 30G side instead of from the substrate 11 side. In this case, the light extraction direction of the semiconductor light-emitting element 1G is Figure 21Above the plane of the paper. Additionally, in this modified example, the oxide semiconductor layer 34 is an ITO film made of ITO.

[0197] Furthermore, the oxide semiconductor layer 34 may also include a thin ohmic contact layer at the interface with the p-type semiconductor layer 14. For example, by including a single element selected from Ni, Pd, Pt, Cr, Mn, Ta, Cu, and Fe or an alloy containing one of them in the oxide semiconductor layer 34 on the side in contact with the p-type semiconductor layer 14, the contact resistance value of the ohmic contact can be reduced.

[0198] In this modified example, the p-side electrode 30G has the same structure as the n-side electrode 20, and includes a p-side electrode layer 31G disposed on the p-type semiconductor layer 14 side and a p-side wiring layer 32 disposed on the p-side electrode layer 31G. Specifically, the p-side electrode layer 31G is stacked on the oxide semiconductor layer 34, and the p-side wiring layer 32 is stacked on the p-side electrode layer 31G. Additionally, the p-side electrode layer 31G and the p-side wiring layer 32 have the same shape in plan view.

[0199] Similar to the n-side electrode 20, the p-side electrode 30G has a power supply portion E1 and an extension portion E2 extending from the power supply portion E1. The power supply portion E1 is the part of the p-side electrode 30G that connects to the power supply terminal 100. In the p-side electrode 30G, in the direction orthogonal to the extending direction of the extension portion E2, the width of the power supply portion E1 is larger than the width of the extension portion E2. That is, in the p-side electrode 30G, the width of the extension portion E2 is smaller than the width of the power supply portion E1. Thus, the p-side electrode 30G has a portion with a width change. That is, the p-side electrode layer 31G and the p-side wiring layer 32 each have a portion with a width change.

[0200] The p-side electrode layer 31G has a first metal layer 31a disposed in the power supply portion E1 and a second metal layer 31b disposed on the side closer to the extension portion E2 than the first metal layer 31a. In this modified example, the second metal layer 31b is directly connected to the first metal layer 31a. The first metal layer 31a and the second metal layer 31b are made of a metal material.

[0201] The p-side electrode layer 31G also has a third metal layer 31c in the extension portion E2. The third metal layer 31c is made of a metal material. The third metal layer 31c is located on the side of the second metal layer 31b opposite to the first metal layer 31a side. Thus, the second metal layer 31b is located between the first metal layer 31a and the third metal layer 31c in the extending direction of the extension portion E2. That is, the p-side electrode layer 31G is truncated into the first metal layer 31a and the third metal layer 31c in the extending direction of the extension portion E2, and the second metal layer 31b is provided in the truncated portion. In this modified example, the third metal layer 31c is directly connected to the second metal layer 31b.

[0202] The second metal layer 31b is disposed at least in the extending direction of the extending portion E2 near the position where the width of the p-side electrode layer 31 changes. In this modification, the second metal layer 31b straddles the position where the width of the p-side electrode layer 31G changes. That is, the second metal layer 31b is formed on both the power supply portion E1 and the extending portion E2.

[0203] In the p-side electrode 30G, the first metal layer 31a, the second metal layer 31b, and the third metal layer 31c are each in contact with the oxide semiconductor layer 34. Therefore, the first metal layer 31a, the second metal layer 31b, and the third metal layer 31c are preferably made of a material that functions as an ohmic contact layer for the oxide semiconductor layer 34.

[0204] In addition, the conductivity of the first metal layer 31a is higher than that of the second metal layer 31b. In addition, the conductivity of the third metal layer 31c is higher than that of the second metal layer 31b. In this modification, the first metal layer 31a and the third metal layer 31c are formed of the same material.

[0205] The first metal layer 31a and the third metal layer 31c can be made of, for example, at least one metal material selected from Al and Ag or an alloy containing these at least one metal material. In this modification, the first metal layer 31a and the third metal layer 31c are made of aluminum.

[0206] The second metal layer 31b having a lower conductivity than the first metal layer 31a and the third metal layer 31c can be made of, for example, at least one metal material selected from Ti, W, and Cr or an alloy containing these at least one metal material. In this modification, the second metal layer 31b is made of titanium.

[0207] In addition, the p-side wiring layer 32 laminated on the p-side electrode layer 31G is continuously disposed on the first metal layer 31a, the second metal layer 31b, and the third metal layer 31c of the p-side electrode layer 31G. That is, the p-side wiring layer 32 is continuously formed in the power supply portion E1 and the extending portion E2. A power supply terminal 100 is connected to a portion of the p-side wiring layer 32 corresponding to the power supply portion E1.

[0208] The p-side wiring layer 32 is made of a metal material. The wiring resistance value of the p-side wiring layer 32 is preferably smaller than that of the p-side electrode layer 31G. That is, the p-side wiring layer 32 is preferably made of a metal material having a wiring resistance value lower than the average wiring resistance value of the p-side electrode layer 31G composed of the first metal layer 31a, the second metal layer 31b, and the third metal layer 31c. In particular, in the extension portion E2, the wiring resistance value of the p-side wiring layer 32 is preferably smaller than the wiring resistance value (average wiring resistance value) of the p-side electrode layer 31G in the extension portion E2. The p-side wiring layer 32 can be composed of, for example, at least one metal material selected from Cu, Ag, Au, or an alloy containing these at least one metal material.

[0209] The p-side electrode 30G configured in this way has the same structure as the n-side electrode 20, so it can be formed by the same method as the n-side electrode 20 of the semiconductor light-emitting element 1 in the above-described Embodiment 1. As an example, the p-side electrode 30G is formed on the ITO layer (film thickness: 0.2 μm) of the oxide semiconductor layer 34. The first metal layer 31a and the third metal layer 31c of the p-side electrode layer 31G are Al layers (film thickness: 0.3 μm), the second metal layer 31b of the p-side electrode layer 31G is a Ti layer (film thickness: 0.3 μm), and the p-side wiring layer 32 is an Au layer (film thickness: 1.0 μm).

[0210] As described above, in the semiconductor light-emitting element 1G according to this modification example, similar to the semiconductor light-emitting element 1 in the above-described Embodiment 1, the n-side electrode 20 has an n-side electrode layer 21 and an n-side wiring layer 22 disposed above the n-side electrode layer 21. The n-side electrode layer 21 has a first metal layer 21a disposed in the power supply portion E1, and a second metal layer 21b disposed on the extension portion E2 side with respect to the first metal layer 21a and having a lower conductivity than the first metal layer 21a.

[0211] With this structure, even if there is a portion with a width change in the n-side electrode 20, an increase in the driving voltage can be suppressed and electromigration can be suppressed. In addition, a decrease in the light extraction efficiency can be suppressed.

[0212] Furthermore, in the semiconductor light-emitting element 1G according to this modification example, the p-side electrode 30G has a p-side electrode layer 31G and a p-side wiring layer 32 disposed above the p-side electrode layer 31G. The p-side electrode layer 31G has a first metal layer 31a disposed in the power supply portion E1, and a second metal layer 31b disposed on the extension portion E2 side with respect to the first metal layer 31a and having a lower conductivity than the first metal layer 31a.

[0213] With this structure, even if there is a portion with a width change in the p-side electrode 30G, an increase in the driving voltage can be suppressed and electromigration can be suppressed.

[0214] In addition, in the semiconductor light-emitting element 1G of this modification, the p-side electrode 30G does not have a p-side diffusion barrier layer, but the p-side electrode 30G may also have a p-side diffusion barrier layer 33 in the same manner as the semiconductor light-emitting element 1 of the above-described Embodiment 1. In this case, the p-side diffusion barrier layer is disposed between the p-side electrode layer 31G and the p-side wiring layer 32.

[0215] Furthermore, in the semiconductor light-emitting element 1G of this modification, the structure of the n-side electrode 20 in Modifications 1 to 5 of the above-described Embodiment 1 may be applied to the p-side electrode 30G.

[0216] (Embodiment 2)

[0217] Next, Figure 22 the semiconductor light-emitting element 1H of Embodiment 2 will be described. In Figure 22 , (a) is a plan view of the semiconductor light-emitting element 1H of Embodiment 2, (b) is a vertical cross-sectional view of the semiconductor light-emitting element 1H taken along line A-A of (a), and (c) is a horizontal cross-sectional view of the semiconductor light-emitting element 1H taken along line B-B of (b).

[0218] The semiconductor light-emitting element 1H of the present embodiment is different in the structure of the n-side electrode 20H from the semiconductor light-emitting element 1 of the above-described Embodiment 1.

[0219] Specifically, in the semiconductor light-emitting element 1 of the above-described Embodiment 1, the n-side electrode layer 21 of the n-side electrode 20 has a first metal layer 21a, a second metal layer 21b, and a third metal layer 21c. However, in the semiconductor light-emitting element 1H of the present embodiment, as shown in (b) and (c) of Figure 22 , the n-side electrode layer 21H of the n-side electrode 20H does not have the third metal layer 21c and is composed of only the first metal layer 21a and the second metal layer 21b. In the present embodiment, the second metal layer 21b of the n-side electrode layer 21H is formed over the entire range of the extension portion E2.

[0220] As described above, according to the semiconductor light-emitting element 1H of the present embodiment, similar to the semiconductor light-emitting element 1 of the above-described Embodiment 1, the n-side electrode 20H has an n-side electrode layer 21H and an n-side wiring layer 22 disposed above the n-side electrode layer 21H. The n-side electrode layer 21H has a first metal layer 21a disposed in the power supply portion E1, and a second metal layer 21b disposed on the side of the extension portion E2 with respect to the first metal layer 21a and having a lower conductivity than the first metal layer 21a.

[0221] With this structure, even if there is a portion where the width changes in the n-side electrode 20H, an increase in the driving voltage can be suppressed and electromigration can be suppressed. In addition, a decrease in the light extraction efficiency can be suppressed.

[0222] (Modification Example 1 of Embodiment 2)

[0223] Next, Figure 23 the semiconductor light-emitting element 1I of Modification Example 1 of Embodiment 2 will be described. In Figure 23 , (a) is a plan view of the semiconductor light-emitting element 1I of Embodiment 2, (b) is a vertical cross-sectional view of the semiconductor light-emitting element 1I taken along line A-A of (a), and (c) is a horizontal cross-sectional view of the semiconductor light-emitting element 1I taken along line B-B of (b).

[0224] The semiconductor light-emitting element 1I of this modification has a different structure of the n-side electrode 20I compared to the semiconductor light-emitting element 1H of the above-described Embodiment 2.

[0225] Specifically, as shown in (c) of Figure 23 , similar to the semiconductor light-emitting element 1B of Modification Example 2 of the above-described Embodiment 1, the extension portion E2 of the n-side electrode 20I of this modification has a portion on the side opposite to the power supply portion E1 side with a width smaller than the width on the power supply portion E1 side. Thus, the n-side electrode layer 21I and the n-side wiring layer 22I in the extension portion E2 each have a portion on the side opposite to the power supply portion E1 side with a width smaller than the width on the power supply portion E1 side.

[0226] In this modification, the extension portion E2 of the n-side electrode 20I is shaped such that the width gradually narrows toward the front end in the extending direction of the extension portion E2. Specifically, the extension portion E2 of the n-side electrode 20I is a tapered shape that tapers toward the front end in the extending direction of the extension portion E2. Thus, the n-side electrode layer 21I and the n-side wiring layer 22I each become a tapered shape that tapers toward the front end in the extending direction of the extension portion E2. More specifically, in the n-side electrode layer 21I, the portion of the extension portion E2 of the second metal layer 21b is a tapered shape of a substantially isosceles triangle.

[0227] As described above, in the semiconductor light-emitting element 1I of this modification, similar to the semiconductor light-emitting element 1H of the above-described Embodiment 2, the n-side electrode 20I has an n-side electrode layer 21I and an n-side wiring layer 22I disposed on the n-side electrode layer 21I. The n-side electrode layer 21I has a first metal layer 21a disposed in the power supply portion E1 and a second metal layer 21b disposed on the side of the extension portion E2 with respect to the first metal layer 21a and having a lower conductivity than the first metal layer 21a.

[0228] Thereby, even if there is a portion with a width change in the n-side electrode 20I, an increase in the driving voltage can be suppressed and electromigration can be suppressed. In addition, a decrease in the light extraction efficiency can be suppressed.

[0229] Also, in the semiconductor light-emitting element 1I of this modification, similar to the semiconductor light-emitting element 1B of the second modification of the above-described Embodiment 1, the extending portion E2 of the n-side electrode 20I has a portion on the side opposite to the power supply portion E1 side with a width smaller than the width on the power supply portion E1 side.

[0230] With this structure, the same effects as those of the semiconductor light-emitting element 1B of the second modification of the above-described Embodiment 1 are achieved. That is, since the area of the n-side electrode 20I can be reduced and the area of the p-side electrode 30 (i.e., the light-emitting area) can be increased, the effect of suppressing electromigration can be maintained and the light output of the semiconductor light-emitting element 1I can be improved. Further, in this case, since the amount of current becomes smaller as it approaches the front end in the extending portion E2 of the n-side electrode 20B, even if the width of the side (front end side) of the extending portion E2 opposite to the power supply portion E1 side is reduced as in this modification, the current density does not increase much, so the occurrence of electromigration can be suppressed.

[0231] (Second modification of Embodiment 2)

[0232] Next, Figure 24 the semiconductor light-emitting element 1J of the second modification of Embodiment 2 will be described. In Figure 24 , (a) is a plan view of the semiconductor light-emitting element 1J of the second modification of Embodiment 2, (b) is a vertical cross-sectional view of the semiconductor light-emitting element 1J taken along line A - A of (a), and (c) is a horizontal cross-sectional view of the semiconductor light-emitting element 1J taken along line B - B of (b).

[0233] The semiconductor light-emitting element 1J of this modification has a different structure of the n-side electrode 20J from the semiconductor light-emitting element 1H of the above-described Embodiment 2.

[0234] Specifically, as shown in (b) of Figure 24 , for the n-side electrode 20J of the semiconductor light-emitting element 1J of this modification, an n-side diffusion barrier layer 23 is further provided in the n-side electrode 20H of the semiconductor light-emitting element 1H of the above-described Embodiment 2. That is, the n-side electrode 20J of this modification, similar to the semiconductor light-emitting element 1D of the fourth modification of the above-described Embodiment 1, has, in addition to the n-side electrode layer 21H and the n-side wiring layer 22, an n-side diffusion barrier layer 23 disposed between the n-side electrode layer 21H and the n-side wiring layer 22.

[0235] As described above, the semiconductor light-emitting element 1J according to this modification is the same as the semiconductor light-emitting element 1H of the above-described Embodiment 2. The n-side electrode 20J has an n-side electrode layer 21H and an n-side wiring layer 22 disposed on the n-side electrode layer 21H. The n-side electrode layer 21H has a first metal layer 21a disposed in the power supply portion E1, and a second metal layer 21b disposed on the extension portion E2 side with respect to the first metal layer 21a and having a lower conductivity than the first metal layer 21a.

[0236] With this structure, even if there is a portion with a width change in the n-side electrode 20J, an increase in the driving voltage can be suppressed and electromigration can be suppressed. In addition, a decrease in the light extraction efficiency can be suppressed.

[0237] In addition, the n-side electrode 20J in the semiconductor light-emitting element 1J of this modification has an n-side diffusion barrier layer 23 between the n-side electrode layer 21H and the n-side wiring layer 22.

[0238] With this structure, the same effect as that of the semiconductor light-emitting element 1D of the modification 4 of the above-described Embodiment 1 is achieved. That is, the mutual diffusion of the metal material constituting the n-side electrode layer 21H and the metal material constituting the n-side wiring layer 22 can be suppressed by the n-side diffusion barrier layer 23. Therefore, a semiconductor light-emitting element 1J with excellent long-term reliability can be realized.

[0239] In addition, in the semiconductor light-emitting element 1J of this modification, the n-side diffusion barrier layer 23 and the n-side electrode layer 21H are made of different materials, but it is not limited thereto. For example, the n-side diffusion barrier layer 23 may be made of the same material as the second metal layer 21b of the n-side electrode layer 21H. In this case, similar to Figure 19 the semiconductor light-emitting element 1E shown, the second metal layer 21b of the n-side electrode layer 21H and the n-side diffusion barrier layer 23 can be integrated to form Figure 25 the semiconductor light-emitting element 1K as shown. That is, similar to Figure 25 the n-side electrode 20K of the semiconductor light-emitting element 1K shown, the second metal layer 21b of the n-side electrode layer 21K can function as the n-side diffusion barrier layer.

[0240] Figure 25 The n-side electrode 20K of the semiconductor light-emitting element 1K shown can be formed by separately depositing a Ti layer that becomes the second metal layer 21b of the n-side electrode layer 21K and a Ti layer that becomes the n-side diffusion barrier layer on the n-side electrode layer 21K, but they can also be deposited simultaneously. For example, the first metal layer 21a (e.g., an Al layer) is formed, and then, the second metal layer 21b (e.g., a Ti layer) that becomes the n-side diffusion barrier layer is deposited by covering the first metal layer 21a by EB evaporation or sputtering, and is formed into a specified shape by photolithography. Thus, Figure 26The n-side electrode 20L of the semiconductor light-emitting element 1L as shown. That is, the second metal layer 21b of the n-side electrode layer 21L that also functions as an n-side diffusion barrier layer and the n-side wiring layer 22 are each recessed in the extension portion E2.

[0241] (Modification Example 3 of Embodiment 2)

[0242] Next, Figure 27 The semiconductor light-emitting element 1M of Modification Example 3 of Embodiment 2 will be described. In Figure 27 , (a) is a plan view of the semiconductor light-emitting element 1M of Modification Example 3 of Embodiment 2, (b) is a vertical cross-sectional view of the semiconductor light-emitting element 1M taken along line A-A of (a), and (c) is a horizontal cross-sectional view of the semiconductor light-emitting element 1M taken along line B-B of (b).

[0243] The semiconductor light-emitting element 1M of this modification example has a different structure of the p-side electrode 30M compared to Figure 21 the semiconductor light-emitting element 1G of Modification Example 5 of the above-described Embodiment 1 as shown.

[0244] Specifically, in the semiconductor light-emitting element 1G of Modification Example 5 of Embodiment 1, the p-side electrode layer 31G of the p-side electrode 30G has a first metal layer 31a, a second metal layer 31b, and a third metal layer 31c, but in the semiconductor light-emitting element 1M of this modification example, as Figure 27 shown in (b) and (c) of, the p-side electrode layer 31M of the p-side electrode 30M does not have the third metal layer 31c and is composed only of the first metal layer 31a and the second metal layer 31b. In this modification example, the second metal layer 31b of the p-side electrode layer 31M is formed throughout the extension portion E2.

[0245] As described above, according to the semiconductor light-emitting element 1M of this modification example, similar to the semiconductor light-emitting element 1 of Embodiment 1, the n-side electrode 20 has an n-side electrode layer 21 and an n-side wiring layer 22 disposed above the n-side electrode layer 21. The n-side electrode layer 21 has a first metal layer 21a disposed in the power supply portion E1 and a second metal layer 21b disposed on the side of the extension portion E2 with respect to the first metal layer 21a and having a lower conductivity than the first metal layer 21a.

[0246] With this structure, even if there is a portion with a width change in the n-side electrode 20, an increase in the driving voltage can be suppressed and electromigration can be suppressed. In addition, a decrease in the light extraction efficiency can be suppressed.

[0247] Furthermore, in the semiconductor light-emitting device 1M according to this modification example, the p-side electrode 30M includes a p-side electrode layer 31M and a p-side wiring layer 32 disposed on the p-side electrode layer 31M. The p-side electrode layer 31M includes a first metal layer 31a disposed in the power supply portion E1, and a second metal layer 31b disposed on the side of the extension portion E2 with respect to the first metal layer 31a and having a lower conductivity than the first metal layer 31a.

[0248] With this structure, even if there is a portion with a width change in the p-side electrode 30M, an increase in the driving voltage can be suppressed and electromigration can be suppressed.

[0249] In addition, in the semiconductor light-emitting device 1M according to this modification example, the p-side electrode 30M does not have a p-side diffusion barrier layer, but the p-side electrode 30M may also have a p-side diffusion barrier layer 33 in the same manner as the semiconductor light-emitting device 1 of the above-described Embodiment 1. In this case, the p-side diffusion barrier layer is disposed between the p-side electrode layer 31M and the p-side wiring layer 32.

[0250] (Other modification examples)

[0251] As described above, the semiconductor light-emitting device of the present invention has been described based on Embodiment 1, 2, and their modification examples, but the present invention is not limited to the above-described Embodiment 1, 2, and their modification examples.

[0252] For example, forms obtained by applying various modifications conceivable by those skilled in the art to the above-described Embodiment 1, 2, and their modification examples, or forms achieved by arbitrarily combining the constituent elements and functions of the above-described Embodiment 1, 2, and their modification examples within the scope not departing from the gist of the present invention are also included in the present invention.

[0253] As an example, the structure of the n-side electrode 20A of the semiconductor light-emitting device 1A of Modification Example 1 of the above-described Embodiment 1 can also be applied to the n-side electrode 20H of the semiconductor light-emitting device 1H of Embodiment 2. In addition, the structure of the n-side electrode 20C of the semiconductor light-emitting device 1C of Modification Example 3 of the above-described Embodiment 1 can also be applied to the n-side electrode 20H of the semiconductor light-emitting device 1H of Embodiment 2.

[0254] Industrial applicability

[0255] The semiconductor light-emitting device of the present invention is useful as a light source for various devices such as for lighting or for displays.

[0256] Explanation of reference numerals

[0257] 1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L, 1M, 1X, 1Y Semiconductor light-emitting device

[0258] 10 Semiconductor laminate structure

[0259] 11 Substrate

[0260] 12 n-type semiconductor layer

[0261] 13 Active layer

[0262] 14 p-type semiconductor layer

[0263] 20, 20A, 20B, 20C, 20D, 20E, 20F, 20H, 20I, 20J, 20K, 20L, 20X, 20Y n-side electrode

[0264] 21, 21A, 21B, 21C, 21E, 21F, 21H, 21I, 21K, 21L n-side electrode layer

[0265] 21a, 31a First metal layer

[0266] 21b, 31b Second metal layer

[0267] 21c, 31c Third metal layer

[0268] 21d Fourth metal layer

[0269] 21e Fifth metal layer

[0270] 22, 22A, 22B, 22C, 22I n-side wiring layer

[0271] 23 n-side diffusion barrier layer

[0272] 30, 30G, 30M p-side electrode

[0273] 31, 31G, 31M p-side electrode layer

[0274] 32 p-side wiring layer

[0275] 33 p-side diffusion barrier layer

[0276] 34 Oxide semiconductor layer

[0277] 40 Insulating film

[0278] 100 Power supply terminal

[0279] E1 Power supply unit

[0280] E2 Extension part

Claims

1. A semiconductor light-emitting element, characterized in that: It includes: A semiconductor layer composed of a compound semiconductor; and An electrode disposed on the semiconductor layer, having a power supply portion and an extension portion extending from the power supply portion; The width of the power supply portion is larger than the width of the extension portion; The electrode has an electrode layer disposed on the semiconductor layer side and a wiring layer disposed above the electrode layer; The electrode layer has a first metal layer disposed in the power supply portion, and a second metal layer disposed on the extension portion side with respect to the first metal layer and directly connected to the first metal layer; The first metal layer and the second metal layer are ohmic-connected to the semiconductor layer; The conductivity of the first metal layer is higher than the conductivity of the second metal layer; The wiring layer is continuously disposed on the first metal layer and the second metal layer.

2. The semiconductor light-emitting element according to claim 1, characterized in that: The second metal layer is disposed in the power supply portion; In the region of the power supply portion where the second metal layer is disposed, the maximum width of the second metal layer is less than or equal to the maximum width of the power supply portion and larger than the maximum width of the extension portion.

3. The semiconductor light-emitting element according to claim 1 or 2, characterized in that: The second metal layer is disposed in the extension portion; In the region of the extension portion where the second metal layer is disposed, the maximum width of the second metal layer is less than or equal to the maximum width of the extension portion and smaller than the maximum width of the power supply portion.

4. The semiconductor light-emitting element according to claim 1 or 2, characterized in that: The second metal layer is disposed in the following region, that is: a region including a position where the differential value of the width of the electrode layer corresponding to the position in the direction from the power supply portion to the extension portion is extremely small, or a region including a position where the differential value is discontinuous.

5. The semiconductor light-emitting element according to claim 1 or 2, characterized in that: A third metal layer is disposed in the extension portion, and the third metal layer is located on the side opposite to the first metal layer side of the second metal layer and is directly connected to the second metal layer; The first metal layer and the third metal layer are formed of the same material.

6. The semiconductor light-emitting element according to claim 5, characterized in that: A fourth metal layer is disposed in the extension portion, and the fourth metal layer is located on the side opposite to the second metal layer side of the third metal layer and is directly connected to the third metal layer; The second metal layer and the fourth metal layer are formed of the same material.

7. The semiconductor light-emitting element according to claim 6, characterized in that: The second metal layer and the fourth metal layer are separated from each other.

8. The semiconductor light-emitting element according to claim 6 or 7, characterized in that: The electrode has a branch portion on the side of the extension portion opposite to the power supply portion side; The fourth metal layer is disposed in the branch portion.

9. The semiconductor light-emitting element according to claim 1 or 2, characterized in that: The electrode has a branch portion on the side of the extension portion opposite to the power supply portion side; The second metal layer is disposed in the branch portion.

10. The semiconductor light-emitting element according to claim 1 or 2, wherein: the extension portion has a part on the side opposite to the power supply portion side with a width smaller than the width of the power supply portion side.

11. The semiconductor light-emitting element according to claim 10, wherein: the width of the extension portion changes such that the width narrows stepwise toward the front end in the extending direction of the extension portion.

12. The semiconductor light-emitting element according to claim 10, wherein: the width of the extension portion gradually narrows toward the front end in the extending direction of the extension portion.

13. The semiconductor light-emitting element according to claim 1 or 2, wherein: a diffusion barrier layer is provided between the electrode layer and the wiring layer.

14. The semiconductor light-emitting element according to claim 13, wherein: the diffusion barrier layer is made of the same material as the second metal layer.

15. The semiconductor light-emitting element according to claim 1 or 2, wherein: in the extension portion, the wiring resistance value of the wiring layer is smaller than the wiring resistance value of the electrode layer.

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