JP2005045038A - Nitride semiconductor light emitting element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress an absorption of light of a light emitting element and to improve a light extraction efficiency of the light emitting element. <P>SOLUTION: The nitride semiconductor light emitting element has a p-type nitride semiconductor layer having a p-electrode, and a n-type nitride semiconductor layer having an n-electrode. The p-type nitride semiconductor layer comprises at least a first layer 10a-1 having a transparent conductive film for transmitting a part of light from the nitride semiconductor light emitting element, and a second layer 10a-2 for covering at least a part of the transparent conductive film and for reflecting a transmitted light from the transparent conductive film. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a gallium nitride-based compound semiconductor device, and particularly to an electrode that is excellent in reflectivity and that can obtain good ohmic contact with a p-type semiconductor layer.

  Conventionally, in a semiconductor light emitting device in which p-type and n-type semiconductor layers are stacked on a translucent substrate and a p-side electrode and an n-side electrode are provided on the same surface, light is emitted from the translucent substrate side. For this purpose, a metal material having high reflectivity is provided on the p-side electrode or the n-side electrode (see, for example, Patent Document 1).

JP 2001-127343 A.

  However, at the interface between the p-type semiconductor layer or the n-type semiconductor layer and the metal material having high reflectivity, part of the light that is emitted from the light-emitting element is absorbed by the metal material, and thus the light extraction efficiency of the light-emitting element is improved. Is hindering.

  Therefore, an object of the present invention is to suppress light absorption in a light emitting element and improve light extraction efficiency of the light emitting element.

  In order to achieve the above object, a nitride semiconductor light emitting device according to the present invention includes a p-type nitride semiconductor layer having a p-electrode and an n-type nitride semiconductor layer having an n-electrode. The p-type nitride semiconductor layer includes a first layer made of a transparent conductive film that transmits a part of light from the nitride semiconductor light-emitting element, and at least a part of the transparent conductive film and covers the transparent conductive film. And at least a second layer that reflects light transmitted from the film.

  The first layer may further have a pad portion. The second layer may further have a pad portion.

  The first layer is made of an oxide containing at least one element selected from the group consisting of zinc (Zn), indium (In), tin (Sn), and magnesium (Mg).

  The second layer is selected from the group consisting of aluminum (Al), titanium (Ti), platinum (Pt), rhodium (Rh), silver (Ag), palladium (Pd), and iridium (Ir). It contains a metal, alloy or oxide containing at least one element.

  The film thickness of the first layer is from 100 to 10,000 mm. The film thickness of the second layer is 200 to 10,000 mm.

  In the nitride semiconductor light emitting device, the material of the p-side electrode or the n-side electrode is made of a metal material having a high reflectance with respect to light that is going to be emitted from the light emitting device, thereby suppressing light absorption. Light extraction efficiency can be improved.

As each semiconductor layer constituting the LED according to the present invention, various nitride semiconductors can be used. Specifically, In _X Al _Y Ga _1- XYN (0 ≦ X, 0 ≦ Y, X + Y ≦) is formed on the substrate by metal organic vapor phase epitaxy (MOCVD), hydride vapor phase epitaxy (HVPE), or the like. A semiconductor in which a plurality of semiconductors such as 1) are formed is preferably used. In addition, the layer structure includes a homo structure having a MIS junction, a PIN junction or a PN junction, a hetero structure, or a double hetero structure. Each layer may have a superlattice structure, or may have a single quantum well structure or a multiple quantum well structure in which an active layer is formed in a thin film in which a quantum effect is generated. In addition, the formation of the p electrode and the n electrode of the nitride semiconductor light emitting device according to the present invention is performed by a normal method such as vapor deposition or sputtering of the material constituting the electrode with respect to the p type nitride semiconductor layer and the n type nitride semiconductor layer. It can be performed by vapor deposition. Alternatively, different film formation methods such as vapor deposition and sputtering can be used.

  The LED is generally formed by growing each semiconductor layer on a specific substrate, but when an insulating substrate such as sapphire is used as the substrate and the insulating substrate is not finally removed, Normally, both the p electrode and the n electrode are formed on the same surface side on the semiconductor layer. In this case, it is possible to take out the emitted light from the semiconductor layer side with the face-up mounting, i.e., the semiconductor layer side arranged on the viewing side, or the face-down mounting, i.e., arrange the substrate side on the viewing side, It is also possible to take out from the substrate side. Of course, it is also possible to mount the face up or face down after finally removing the substrate. In addition, a board | substrate is not limited to sapphire, For example, well-known members, such as a spinel, SiC, GaN, GaAs, can be used. Further, by using a conductive substrate such as SiC, GaN, or GaAs as the substrate, the p electrode and the n electrode can be arranged to face each other.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiment described below exemplifies an LED for embodying the technical idea of the present invention, and does not specify the LED of the present invention as follows. Further, the size and positional relationship of the members shown in each drawing may be exaggerated for clarity of explanation.

(Embodiment 1)
The LED of the present embodiment will be described based on FIGS. The LED of the present embodiment is an LED in which a p electrode and an n electrode are arranged on the same surface side as shown in the figure. FIG. 2 is a schematic view of the LED of the present embodiment as viewed from the electrode arrangement surface side. FIG. 1 is a schematic cross-sectional view showing the layer structure of the LED according to the present embodiment, and shows a cross section taken along line XX in FIG.

  As shown in FIG. 1, the LED of the present embodiment has, for example, a GaN buffer layer 2, a non-doped GaN layer 3, a Si-doped GaN layer 4 serving as an n-type contact layer, and an n-type cladding layer on a sapphire substrate 1. The Si-doped GaN layer 5, the InGaN layer 6 serving as an active layer, the Mg-doped AlGaN layer 7 serving as a p-type cladding layer, and the Mg-doped GaN layer 8 serving as a p-type contact layer have a layered structure. Further, the Mg-doped GaN layer 8, the Mg-doped AlGaN layer 7, the InGaN layer 6, the Si-doped GaN layer 5, and the Si-doped GaN layer 4 are partially removed by etching or the like, and an n electrode is formed on the exposed surface of the Si-doped GaN layer 4. 9 is formed, and a p-electrode 10 is provided on substantially the entire upper surface of the Mg-doped GaN layer 8. In this embodiment, the n-type nitride semiconductor described in the claims corresponds to the Si-doped GaN layer 4 serving as the n-type contact layer, and the p-type nitride semiconductor serves as the p-type contact layer. This corresponds to the GaN layer 8.

  In the present embodiment, the p-electrode 10 is provided separately from the light reflecting portion 10a that reflects light from the LED (hereinafter also referred to as “p light reflecting portion”) and the light reflecting portion 10a. A pad portion 10b (hereinafter referred to as a “p pad portion”) to which a conductive member is connected in order to be finally connected to the external lead electrode. The p-light reflecting portion 10a includes, in order from the p-type contact layer 8 side, a second layer having a reflectance higher than that of the first layer 10a-1 and the first layer 10a-1 at the dominant wavelength of light from the LED. And at least the layer 10a-2. Here, the first layer 10a-1 has a refractive index lower than that of the p-type contact layer 8, so that a part of the light from the p-type contact layer 8 is totally reflected and other light is transmitted. Further, the second layer 10a-2 having a higher reflectance than the first layer 10a-1 is configured to totally reflect the light transmitted through the first layer 10a-1.

Next, a specific material constituting the p light reflecting portion 10a will be described. The first layer 10a-1 is made of a transparent conductive film that transmits at least part of light from the light emitting element. For example, the first layer 10a-1 is an oxide containing at least one element selected from the group consisting of zinc, indium, tin, and magnesium. More specifically, an oxide of Zn, In, Sn, Mg, etc. represented by ZnO, In ₂ O ₃ , SnO ₂ , ITO (complex oxide of In and Sn), MgO, etc. It consists of a transparent conductive film with low resistance. Furthermore, the first layer 10a-1 is preferably laminated on the p-type contact layer 8 via a metal such as Ni or Co or an oxide thereof. By configuring in this way, the first layer 10a-1 is more easily in ohmic contact with the p-type contact layer 8. The second layer 10a-2 is made of at least one selected from a metal, an alloy, or an oxide that covers at least a part of the transparent conductive film and reflects transmitted light from the transparent conductive film. For example, the second layer 10a-2 is a layer containing a metal, an alloy, or an oxide containing at least one element selected from the group consisting of aluminum, titanium, platinum, rhodium, silver, palladium, and iridium. The p pad portion 10b is composed of at least a first layer 10b-1 and a second layer 10b-2 in order from the p-type contact layer 8 side. Here, the second layer 10b-2 preferably has a higher reflectance than the first layer 10b-1 at the main wavelength of light from the light emitting element.

  In the present embodiment, the n-electrode 9 includes at least a first layer 9-1 and a second layer 9-2 in order from the n-type contact layer 4 side. The material constituting the first layer of the n-electrode is not particularly limited, but Ti, V, Cr, Mn, Co, Zn, Nb, Mo, Ru, Ta, Re, W, Ni, Mg, Zr At least one of In, Sn, and ITO can be preferably used. Among these, considering comprehensively the adhesion to the n-type contact layer 4, contact resistance, and light transmittance, Ti, Nb, ITO, more preferably Ti, Nb, and more preferably Ti can be suitably used. .

  Further, the material constituting the first layer 10b-1 in the p pad portion 10b is not particularly limited, but Ti, V, Cr, Mn, and the like as in the first layer 9-1 of the n-electrode. At least one of Co, Zn, Nb, Mo, Ru, Ta, Re, W, Ni, Mg, Zr, In, Sn, and ITO can be suitably used. Among these, considering comprehensively the adhesiveness and light transmittance with the p-light reflecting portion 10a, Ti, Nb, ITO, more preferably Ti, Nb, and more preferably Ti can be suitably used.

  The second layer 9-2 of the n-electrode 9 and the second layer 10a-2 of the p-electrode 10 reflect the light transmitted through the first layer and are lower together with the first layer. A material that provides contact resistance is selected. The main purpose of the second layer is to reflect light, and the thickness of the second layer varies depending on the material, but can be 100 mm or more, more preferably 150 mm or more. Further, the upper limit of the film thickness is preferably 10,000 mm or less in consideration of production efficiency. The material constituting the second layer is not particularly limited, but a metal, an alloy containing at least one element selected from the group consisting of Ag, Rh, Al, Ti, Pt, Pd, and Ir, Or an oxide can be used conveniently. Among these, Rh, Al, and Ag are particularly preferable in view of the adhesiveness with the first layer, contact resistance (particularly, n electrode), and light reflectivity. Further, since diffusion of Al may cause a problem such as migration of Ag, Rh is most preferable in consideration of reliability.

  In the LED of the present embodiment, both the n electrode 9 and the p pad portion 10b have the same configuration. With this configuration, the n electrode and the p pad portion can reflect light to improve the light extraction efficiency, and the n electrode and the p pad portion can be formed at the same time, thus simplifying the manufacturing process. Can be realized.

  Further, the p-pad portion 10b basically does not need to consider contact resistance (ohmic contact) with the p-type contact layer 8 (the first layer 10a-1 of the p-light reflecting portion 10a is a p-type contact layer). 8 is in ohmic contact with each other, so there is not much difference in contact resistance even if the p-pad portion 10b is changed). Is preferable as a result.

  Here, both the n-electrode 9 and the p-pad portion 10b are configured to include the first layer and the second layer as described above, but at least one includes the first layer and the second layer. With the configuration, the effect of the present invention can be obtained. Of course, it goes without saying that the effect can be maximized by configuring both the n-electrode and the p-pad portion as described above, as in this embodiment.

  Moreover, although the p pad part in this Embodiment was set as the structure provided in the 2nd layer 10a-2 of the p light reflection part 10a, this invention is not limited to this, For example, p pad part 10b and p light The second layer 10a-2 of the reflecting part 10a and the first layer 10a-1 of the p light reflecting part 10a are arranged at different positions, so that the p pad part 10b is replaced with the p light reflecting part 10a. Instead of being provided on the second layer 10a-2, it may be provided directly on the first layer 10a-1 of the p-light reflecting portion 10a.

(Embodiment 2)
The LED of the present embodiment will be described based on FIGS. The LED of the present embodiment is the same as the LED of the first embodiment except that the p-electrode differs from the LED of the first embodiment in the following points. FIG. 4 is a schematic view of the LED of the present embodiment as viewed from the electrode arrangement surface side. FIG. 3 is a schematic cross-sectional view showing the layer structure of the LED of the present embodiment, and represents a cross section taken along the line XX of FIG.

  In the LED of the present embodiment, both the p-light reflecting portion 10 a and the p-pad portion 10 b are in contact with the p-type contact layer 8. Specifically, the p-light reflecting portion 10 a has an opening that exposes the p-type contact layer 8, and the p-pad portion 10 b is in contact with the p-type contact layer 8 on the exposed surface of the opening. In addition, the dotted line in FIG. 4 shows this opening part.

  With this configuration, even if the adhesiveness between the p-type contact layer 8 and the p-light reflecting portion 10a is weak and / or the adhesiveness of the p-pad portion 10b is weak with respect to the p-light reflecting portion 10a. However, since the p-pad portion 10b can be directly arranged on the p-type contact layer 8, peeling of the p-pad portion 10b can be greatly reduced as compared with the case where the p-pad portion 10b is provided on the p-light reflecting portion 10a. Can do. That is, in the present embodiment, the adhesion between the p pad portion 10b and the p-type contact layer 8 is the same as the adhesion between the p light reflection portion 10a and the p type contact layer 8, or the p pad portion 10b and the p light reflection portion. This configuration is particularly effective when it is stronger than at least one of the adhesiveness with 10a.

  In the present embodiment, the p light reflecting portion 10a has an opening that exposes the p-type contact layer 8. However, the present invention is not limited to this, and, for example, the p pad portion 10b and the p light reflecting portion 10a. Since the light reflecting portion 10a and the p-type contact layer 8 are arranged at different positions, the p pad portion 10b is directly provided on the p-type contact layer 8 instead of being provided on the p light reflecting portion 10a. It may be provided.

  Examples according to the present invention will be described in detail below. Needless to say, the present invention is not limited to the following examples.

  The LED of this embodiment will be described with reference to FIGS. The semiconductor stacked structure of this example is the same as that of the first embodiment. FIG. 1 is a schematic cross-sectional view in the XX direction of FIG. 2, and FIG. 2 is a schematic top view of the LED in this example as viewed from the electrode arrangement surface.

  W is used for the first layer of the n electrode 9 and the p pad portion 10b provided in the LED of this embodiment, Pt is used for the second layer, and W (200 （) as a whole of the n electrode and the p pad portion 10b. / Pt (2000 cm) / Au (5000 cm). In this specification, “W / Pt / Au” indicates that layers are stacked from the semiconductor side in the order of description of the element symbols. In the n-electrode 9, W / Pt / Au is 9-1 in FIG. 9-2 and 9-3, and in the p pad portion 10b, W / Pt / Au corresponds to 10b-1, 10b-2 and 10b-3 in FIG. The p-light reflecting portion 10a in the present embodiment is made of ITO (2000 （) as the first layer 10a-1 and Al (2000Å) as the second layer 10a-2. Here, at the interface between the p-type contact layer 8 (refractive index is 2.50) and the first layer 10a-1 ITO (refractive index is 2.12), a part of light emission is totally reflected. It is configured.

  In the above configuration, Pt is used as a barrier layer for reducing the diffusion of W into Au or Au into W, and Au in the final layer is for making it easy to connect the Au wire. Thus, by using a material having a relatively high melting point, diffusion of the members before and after that can be effectively reduced.

  With the configuration of this embodiment, most of the light traveling from the p-type contact layer 8 to the p-electrode is totally reflected at the interface between ITO and Al, and part of the light transmitted through the ITO is also totally reflected by Al. The Therefore, the light extraction efficiency of the light emitting element can be improved as compared with the light emitting element in which Al is directly provided on the p-type contact layer 8.

  The LED of the present embodiment will be described based on FIGS. The LED of this example is configured in the same manner as the LED of Example 1 except for the following points. FIG. 3 is a schematic cross-sectional view in the XX direction of FIG. 4, and FIG. 4 is a schematic top view of the LED in this example as viewed from the electrode arrangement surface.

  That is, ITO (2000 ス ズ), which is indium tin oxide, is used as the first layer 10a-1 of the p-light reflecting portion 10a, and Al (2000Å) is used as the second layer 10a-2. Further, Ti (60 Å) / Rh (200 Å) / Pt (2000 Å) / Au (5000 Å) is used as the n electrode 9 and the p pad portion 10b.

  Ti takes into consideration the adhesion to the member directly below (n-type contact layer 4 in the case of n electrode, light reflecting portion 10a in the case of p electrode), contact resistance (particularly in the case of n electrode), translucency, etc. select. The main reason for selecting Rh is that it has good reflectivity for light with a wavelength of 370 to 500 nm using a nitride semiconductor as an active layer, as well as adhesion to Ti and contact resistance. Further, Pt is used as a barrier layer for reducing diffusion of Rh into Au or Au into Rh, and Au in the final layer is for making it easy to connect Au wires.

  In addition, it is thought that Rh functions as a barrier layer for reducing diffusion of Au or Pt alone or in combination with Pt. By using a plurality of materials having a relatively high melting point in this way, diffusion of members before and after that can be effectively reduced. Incidentally, the melting point of Ti is 1667 ° C., the melting point of Rh is 1960 ° C., the melting point of Pt is 1769 ° C., and the melting point of Au is 1064 ° C. It should be noted that Ti / Rh / Au can be used without using Pt, although the function of preventing diffusion of Au is somewhat reduced.

  When Rh, which is the second layer, is directly formed on the n-type contact layer 4 without using Ti as the first layer, the reflectivity for light of 370 to 550 nm is greatly improved, but the n-type contact layer The contact resistance with 4 becomes large and does not function sufficiently as an LED. Further, when Ti is made 300 mm or more, not only the reflectance for light of 370 to 550 nm is lowered, but also the contact resistance with the n-type contact layer 4 is increased. Based on such experimental results, the inventor of the present application has a Ti film thickness of 10 to 300 mm, preferably 20 to 200 mm, more preferably 30 to 120 mm, and even more preferably 40 to 80 mm in the Ti / Rh system. It was found that the contact resistance with the n-type contact layer 4 and the light reflectivity can be both achieved by setting the thickness to 50 to 70 mm more preferably.

  By using ITO for the light reflecting portion of the p-electrode, the light extraction efficiency can be greatly improved as compared with the prior art. Also, ohmic contact can be easily obtained by providing ITO on the p-type contact layer 8 via Ni or NiO. By comprising in this way, the light from LED can be taken out effectively, ensuring the ohmic characteristic of the p-type contact layer 8 and p electrode.

  However, ITO has poor adhesion to the p-pad portion 10b made of metal. For this reason, if the p-pad portion 10b is directly provided on the ITO, peeling may occur later. This embodiment is effective in such a case, and the ITO that is the p-light reflecting portion 10a has an opening through which the p-type contact layer 8 is exposed. Further, the p pad portion 10b is configured to be in direct contact with the first layer 10a-1, the second layer 10a-2, and the p-type contact layer 8 of the p light reflecting portion 10a at the opening. . That is, the adhesive force between the p pad portion 10b and the p-type contact layer 8 is the adhesive force between the p pad portion 10b and the p light reflecting portion 10a and / or the adhesive force between the p light reflecting portion 10a and the p type contact layer 8. It is characterized by being stronger. Further, the p-light reflecting portion 10a and the p-pad portion 10b are provided in contact with each other so as to overlap in the vicinity of the opening, thereby effectively injecting current.

  In this configuration, the ohmic contact is basically not provided immediately below the contact surface between the p pad portion 10b and the p-type contact layer 8, so that current does not flow easily in that region, but the light immediately below the p pad portion 10b is not easily light. There is no profit. Rather, the current can be expanded while reducing the peeling of the p-pad portion 10b, which is preferable as a result.

  In the configuration of the present embodiment, the p pad portion 10b is in direct contact with the p-type contact layer 8 without passing through the p light reflecting portion 10a, so that the p pad portion 10b can be prevented from peeling off. Of course, by adopting the configuration as in this embodiment, it is possible to prevent the p-pad portion 10b from being peeled even in the case of the p-pad portion 10b in another embodiment such as W / Pt / Au. preferable.

  In the present embodiment, the p light reflecting portion 10a has been described using ITO, which is Ni and indium tin oxide, but it is also possible to use a single ITO.

  FIG. 5 is a schematic top view of a light emitting device using the semiconductor light emitting element according to the present invention, and FIG. 6 is a schematic cross-sectional view in the diagonal direction in FIG. Hereinafter, a semiconductor light emitting element and a light emitting device according to this example will be described in detail with reference to the drawings.

For example, SiO ₂ is formed as an insulating material 501 on the mount substrate 500 with good heat dissipation, and a first metal film 502 and a second metal film 503 such as Al or an alloy containing Al are formed thereon. The first metal film is formed so as to be surrounded by the second metal film. Two or more nitride semiconductor light emitting devices 601 in which an n-electrode 602 and a p-electrode 603 are formed on the same plane side are connected to the second metal film so that the n-electrode 602 is in contact with the first metal film 502. Form to connect. Here, the electrode connected to the first metal film 502 may be the p-electrode 603, and the electrode connected to the second metal film 503 may be the n-electrode 602. That is, a plurality of nitride semiconductor light emitting elements may be in contact with one metal film with the same conductivity type. The first metal film 502 and the second metal film 503 are not required to be in contact with each other. As illustrated in FIG. 5, the first metal film 502 is square and the second metal film 503 is In the case of a shape spaced apart from the square first metal film at equal intervals, or a shape in which the first metal film is circular and the second metal film is spaced from the circular first metal film at equal intervals It may be the case.

  Further, the first metal film 502 and the n-electrode 602, and the second metal film 503 and the p-electrode 603 are joined by a eutectic alloy 505 containing at least Au and Sn formed at 350 ° C. The eutectic alloy is formed to have a thickness of 5 μm or less so as not to go around the side surface of the nitride semiconductor element.

  In a state where the plurality of nitride semiconductor light emitting elements are connected to the first metal film and the second metal film, the nitride semiconductor light emitting device is obtained by further injecting a resin 504 to obtain a nitride semiconductor light emitting device.

  As described above, by forming a plurality of nitride semiconductor light-emitting elements on the mount substrate face-down, a plurality of nitride semiconductor light-emitting elements can be mounted at an equipotential, and nitride semiconductors can be mounted rather than mounting face-up. The light emitting device can be reduced in size. Further, by using a eutectic alloy for bonding, a relatively large light emitting area can be obtained even if the size is reduced. Further, by adjusting the film thicknesses of the first metal film and the second metal film, the light emitting surface of the element can be easily made horizontal or inclined from the horizontal.

FIG. 1 is a schematic cross-sectional view according to one embodiment of the present invention. FIG. 2 is a schematic top view according to one embodiment of the present invention. FIG. 3 is a schematic cross-sectional view according to one embodiment of the present invention. FIG. 4 is a schematic top view according to one embodiment of the present invention. FIG. 5 is a schematic top view according to one embodiment of the present invention. FIG. 6 is a schematic cross-sectional view according to one embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Sapphire substrate 2 ... GaN buffer layer 3 ... Non-doped GaN layer 4 ... Si-doped GaN layer 5 serving as an n-type contact layer 5 ... Si-doped GaN layer 6 serving as an n-type cladding layer ..InGaN layer 7 as an active layer ... Mg doped AlGaN layer 8 as a p-type cladding ... Mg doped GaN layer 9, 602 ... n electrode 9-1 ... n as a p-type contact layer The first layer 9-2 of the electrode ... The second layer 9-3 of the n electrode ... The third layer 9-4 of the n electrode ... The fourth layer 10, 603 of the n electrode P electrode 10a... P light reflecting portion 10a-1... P light reflecting portion first layer 10a-2... P light reflecting portion second layer 10b. DESCRIPTION OF SYMBOLS 1 ... 1st layer 10b-2 of p pad part ... 2nd layer 10b-3 ... p pad part of p pad part Third layer 10b-4 ... p pad fourth layer 500 ... mount substrate 501 ... insulating material 502 ... first metal film 503 ... second metal film 504: Resin 505: Eutectic alloy

Claims (8)

In a nitride semiconductor light emitting device having a p-type nitride semiconductor layer having a p-electrode and an n-type nitride semiconductor layer having an n-electrode,
The p-type nitride semiconductor layer includes a first layer made of a transparent conductive film that transmits a part of light from the nitride semiconductor light-emitting element, and covers at least a part of the transparent conductive film. And a second layer that reflects the transmitted light from the nitride semiconductor light-emitting element. The nitride semiconductor light emitting element according to claim 1, wherein the first layer further has a pad portion. The nitride semiconductor light emitting element according to claim 1, wherein the second layer further has a pad portion. The nitride semiconductor light emitting element according to claim 2, wherein the pad electrode is further provided for the p-type nitride semiconductor layer. The first layer is made of an oxide containing at least one element selected from the group consisting of zinc (Zn), indium (In), tin (Sn), and magnesium (Mg). 5. The nitride semiconductor light emitting device according to 1 to 4. The second layer is at least one selected from the group consisting of aluminum (Al), titanium (Ti), platinum (Pt), rhodium (Rh), silver (Ag), palladium (Pd), and iridium (Ir). The nitride semiconductor light emitting device according to claim 1, comprising a metal, an alloy, or an oxide containing any of the above elements. 7. The nitride semiconductor light emitting device according to claim 1, wherein the first layer has a thickness of 100 to 10,000 mm. 8. The nitride semiconductor light-emitting element according to claim 1, wherein the second layer has a thickness of 200 to 10,000 mm.

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