JP2012156555A - Nitride semiconductor light emitting element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nitride semiconductor light emitting element which improves the light extraction efficiency.SOLUTION: A nitride semiconductor light emitting element includes a first n-type nitride semiconductor layer, a light emitting layer, a p-type nitride semiconductor layer, and a second n-type nitride semiconductor layer in this order. The nitride semiconductor light emitting element has an electrode formed by a transparent conductive film formed on the second n-type nitride semiconductor layer and a current inhibition portion formed by forming an insulation layer at a recessed portion, formed on a surface of the second n-type nitride semiconductor layer and having a depth that reaches at least the light emitting layer side surface of the first n-type nitride semiconductor layer, so as to cover a bottom surface and a side surface of the recessed portion.

Description

  The present invention relates to a nitride semiconductor light emitting device, and more particularly to a nitride semiconductor light emitting device with improved light extraction efficiency.

  Nitride semiconductor light-emitting elements have attracted attention as illumination light sources, white light-emitting diode excitation light sources, and the like. A nitride semiconductor light-emitting device generally has a structure in which a light-emitting layer is sandwiched between an n-type nitride semiconductor layer and a p-type nitride semiconductor layer, and electrons and holes are recombined in the light-emitting layer. Light emission occurs.

  FIG. 9 is a schematic cross-sectional view of a conventional nitride semiconductor light emitting device described in Patent Document 1. In the nitride semiconductor light emitting device shown in FIG. 9, a stacked body made of nitride semiconductor layers is formed on a substrate 901. The stacked body includes a first n-type nitride semiconductor layer 902, an active layer 903, a p-type nitride semiconductor layer 904, and a second n-type nitride semiconductor layer 905 in this order from the substrate 901 side. In the second n-type nitride semiconductor layer 905, a p-side electrode 906 for injecting holes into the p-type nitride semiconductor layer 904 is formed, and in the first n-type nitride semiconductor layer 902, n A side electrode 907 is formed.

  Here, for example, a metal such as Al is used for the p-side electrode 906. However, if a metal is used for the p-side electrode material, the electrode absorbs light because of the opaqueness, and the light extraction efficiency decreases. There was a problem to do.

JP 2006-135311 A

  The present invention has been made to solve the above-mentioned problems, and an object thereof is to provide a nitride semiconductor light emitting device with improved light extraction efficiency.

The present invention includes the following.
[1] A nitride semiconductor light-emitting device including a first n-type nitride semiconductor layer, a light-emitting layer, a p-type nitride semiconductor layer, and a second n-type nitride semiconductor layer in this order,
An electrode made of a transparent conductive film formed on the second n-type nitride semiconductor layer;
A concave portion formed on the surface of the second n-type nitride semiconductor layer and having a depth reaching at least the light emitting layer side surface of the first n-type nitride semiconductor layer covers the bottom surface and the side surface of the concave portion. A current blocking portion formed by forming an insulating layer on
A nitride semiconductor light emitting device having:

  [2] The nitride semiconductor light-emitting element according to [1], wherein the electrode made of the transparent conductive film is formed on a partial surface of the second n-type nitride semiconductor layer.

  [3] The nitride semiconductor light emitting device according to [2], wherein the electrode made of the transparent conductive film has a single or a plurality of line shapes or a network shape.

  [4] The nitride semiconductor light emitting device according to any one of [1] to [3], wherein the electrode made of the transparent conductive film is formed by a sputtering method.

  [5] In any one of [1] to [4], at least a part of the surface of the second n-type nitride semiconductor layer on the side where the electrode made of the transparent conductive film is formed has an uneven shape. The nitride semiconductor light emitting device described.

  [6] The nitride semiconductor light-emitting element according to any one of [1] to [5], further including a pad electrode for wire bonding connected to the electrode made of the transparent conductive film.

  [7] The nitride semiconductor light emitting element according to [6], wherein the pad electrode is formed on the current blocking portion.

  ADVANTAGE OF THE INVENTION According to this invention, the nitride semiconductor light-emitting device with improved light extraction efficiency compared with the past is provided.

It is the schematic which shows a preferable example of the nitride semiconductor light-emitting device of this invention. It is a top view which shows the resist mask for recessed part formation. It is a schematic sectional drawing of the nitride semiconductor light-emitting device in the middle of manufacture after a recessed part formation. Is a top view showing a SiO ₂ resist mask etch. It is a schematic sectional drawing of the nitride semiconductor light-emitting device in the middle of manufacture after insulating layer formation. It is a top view which shows the resist mask for electrode formation which consists of a transparent conductive film. It is a schematic sectional drawing of the nitride semiconductor light-emitting device in the middle of manufacture after electrode formation which consists of a transparent conductive film. It is a schematic sectional drawing which shows another preferable example of the nitride semiconductor light-emitting device of this invention. It is a schematic sectional drawing of the conventional nitride semiconductor light-emitting device.

  1A and 1B are schematic views showing a preferred example of the nitride semiconductor light emitting device of the present invention. FIG. 1A is a top view and FIG. 1B is a cross-sectional view. The nitride semiconductor light emitting device shown in FIG. 1 includes a first n-type nitride semiconductor layer 102, a light emitting layer 103, a p-type nitride semiconductor layer 104, and a second n-type nitride semiconductor layer 105 on a substrate 101. In this order. In addition, an electrode 106 made of a transparent conductive film is provided on part of the second n-type nitride semiconductor layer 105. Further, the second n-type nitride semiconductor layer 105 is formed with a recess having a depth reaching the first n-type nitride semiconductor layer 102, and the insulating layer covers the bottom and side surfaces of the recess. 109 is formed. The nitride semiconductor light emitting device has a pad electrode 107 connected to the electrode 106 made of a transparent conductive film on the recess, and a pad electrode 108 on the first n-type nitride semiconductor layer 102. .

  In the present invention, the electrode formed on the second n-type nitride semiconductor layer 105 is not a metal thick film electrode but an electrode made of a transparent conductive film. When an opaque metal is used for the electrode, light is absorbed. However, by using a transparent conductive film, light absorption by the electrode can be suppressed, and thereby light extraction efficiency can be improved.

  Here, the thickness of the electrode made of the transparent conductive film is preferably 10 to 1000 nm, and more preferably 50 to 500 nm. If the thickness is less than 10 nm, current diffusion tends to be insufficient, and if it exceeds 1000 nm, the transmittance of the transparent conductive film tends to deteriorate. Examples of the electrode material include ITO (indium-tin oxide), tin oxide, indium oxide, zinc oxide, gallium oxide, IZO (indium oxide, zinc oxide), AZO (zinc oxide, aluminum oxide), GZO (zinc oxide, Gallium oxide).

  In the present invention, the electrode 106 made of a transparent conductive film is preferably formed on a part of the surface of the second n-type nitride semiconductor layer 105. This is because even when a transparent conductive film is used, it is not completely transparent and absorbs light of, for example, about 5 to 10%, so that it is preferable to make the electrode formation region smaller. Thereby, the light absorption by an electrode can be suppressed more. The electrode 106 made of a transparent conductive film preferably has a shape made up of a plurality of lines, as shown in FIG. Also with this configuration, the electrode formation region can be reduced. The shape of the electrode 106 made of a transparent conductive film is not limited to the shape shown in FIG. 1A, and may be, for example, a shape made of a single line or a mesh shape. When the electrode has a plurality of lines or a mesh shape, the distance between the lines and the mesh gap distance are not particularly limited, but the current can be sufficiently diffused in the second n-type nitride semiconductor layer 105. It is preferable that the distance be a short distance. As will be described later, the second n-type nitride semiconductor layer 105 has a function as a current diffusion layer, but since it does not have a higher current diffusion capability than a metal, the current diffusion distance is limited. Therefore, when the distance between the lines and the gap distance between the meshes are large, there is a possibility that current spreading cannot be achieved sufficiently. For example, in the case of the line shape shown in FIG. 1A, the distance between the lines can be about 5 to 100 μm. By using a line-like or mesh-like electrode, light can be directly extracted from a gap that does not have an electrode without using an electrode.

  The electrode 106 made of a transparent conductive film is preferably formed by sputtering. By forming using a sputtering method, the transparency of the electrode can be further increased. In addition, since the contact resistance between the second n-type nitride semiconductor layer and the transparent conductive film can be lowered, the voltage can be reduced.

  The nitride semiconductor light emitting device of the present invention has a second n-type nitride semiconductor layer 105 on the p-type nitride semiconductor layer 104. The second n-type nitride semiconductor layer 105 functions as a current diffusion layer. When an electrode is provided directly on the p-type nitride semiconductor layer, current diffusion does not occur in the p-type nitride semiconductor layer, and thus it is necessary to form an electrode over the entire region to emit light. In this case, even when a transparent electrode is used as the electrode, the electrode is formed on the entire surface, so that the light extraction efficiency tends to decrease. By providing the n-type nitride semiconductor layer, current diffusion occurs in the n-type nitride semiconductor layer, so that it is not necessary to provide an electrode on the entire surface. This makes it possible to directly extract light from a region where no electrode is formed.

  The second n-type nitride semiconductor layer 105 is not particularly limited, and for example, an n-type GaN layer, an n-type InGaN layer, an n-type AlGaN layer, or a stacked structure in which a plurality of these are combined can be used. The thickness of the second n-type nitride semiconductor layer 105 can be set to, for example, 10 to 3000 nm, and preferably 10 to 1000 nm.

  It is preferable that at least a part of the surface of the second n-type nitride semiconductor layer 105 on the side where the electrode 106 made of a transparent conductive film is formed has an uneven shape. Since the nitride semiconductor layer has a high refractive index, it may be reflected at the interface with air or resin used for the package due to light refraction, and light generated in the light emitting layer may return to the inside of the device. When light returns to the inside of the element, the light is absorbed again by the light emitting layer, and light loss occurs. By forming irregularities on the surface of the second n-type nitride semiconductor layer 105, it is possible to suppress light from returning to the inside of the element due to refraction, thereby improving light extraction efficiency.

  In the present invention, it is preferable to have a current blocking portion like the nitride semiconductor light emitting device shown in FIG. By providing the current blocking portion, the light emission efficiency can be improved. For example, the current blocking unit removes a part of the second n-type nitride semiconductor layer 105, and forms at least a second p-type nitride semiconductor layer 104 on the surface of the second n-type nitride semiconductor layer 105. It can be formed by providing a recess having a depth reaching the surface of the n-type nitride semiconductor layer 105 side. As described above, since the second n-type nitride semiconductor layer 105 functions as a current diffusion layer, no current is diffused in the region where the second n-type nitride semiconductor layer 105 is removed, and light emission does not occur. Further, a part of the second n-type nitride semiconductor layer 105 and the p-type nitride semiconductor layer 104 is removed to provide a recessed part where the p-type layer is exposed, and an n-type electrode such as a transparent conductive film is formed in the recessed part. By doing so, since the contact resistance between the p-type nitride semiconductor layer 104 and the transparent conductive film is very high, it can function as a current blocking portion. In this case, when the transparent conductive film is formed by sputtering, the portion where the transparent conductive film is in contact with the second n-type nitride semiconductor layer has low contact resistance, and the portion where the transparent conductive film is in contact with the p-type nitride semiconductor layer is sputtered. Since the resistance is increased by this plasma, it works as a better current blocking portion.

  Alternatively, as shown in FIG. 1, the current blocking portion has a depth reaching at least the surface of the first n-type nitride semiconductor layer 102 on the light-emitting layer 103 side on the surface of the second n-type nitride semiconductor layer 105. The insulating layer 109 may be formed so as to cover the bottom surface and the side surface of the recess. According to the current blocking portion having such a configuration, since the light emitting layer capable of absorbing light is removed, the light extraction efficiency can be further improved. Examples of the insulating layer 109 include silicon oxide, aluminum oxide, titanium oxide, silicon nitride, and aluminum nitride. Moreover, the thickness of the insulating layer 109 can be 10-1000 nm, for example.

  In the nitride semiconductor light emitting device of the present invention, as shown in FIG. 1, it is preferable that pad electrodes 107 and 108 for wire bonding are formed in order to maintain wire bonding performance. One pad electrode 107 is connected to an electrode 106 made of a transparent conductive film, and the pad electrode 107 and the electrode 106 made of a transparent conductive film are preferably in contact with each other. As a result, a current is efficiently supplied from the pad electrode 107 to the electrode 106 made of a transparent conductive film. As the pad electrode, a conventionally known material can be used. For example, a laminated body or alloy of Ti and Al, a laminated body or alloy of Hf and Al, or the like can be used.

  The pad electrode 107 is preferably formed on the current blocking portion. Since the pad electrode is usually opaque, if light is emitted immediately below it, the light is absorbed by the pad electrode, causing a loss of light, which causes a decrease in light extraction efficiency. By providing the pad electrode on the current blocking portion, light is not absorbed by the pad electrode, and the light extraction efficiency can be improved.

  As the substrate 101, the first n-type nitride semiconductor layer 102, the light emitting layer 103, and the p-type nitride semiconductor layer 104, any conventionally known appropriate material can be used.

  As described above, in the nitride semiconductor light-emitting device of the present invention, the uppermost layer of the laminate composed of the nitride semiconductor layers is the second n-type nitride semiconductor layer, and the second n-type nitride semiconductor layer is formed on the second n-type nitride semiconductor layer. It is characterized in that an electrode made of a transparent conductive film is formed. Even when an electrode is formed on a part of the surface of the second n-type nitride semiconductor layer by using the second n-type nitride semiconductor layer as the uppermost layer of the stacked body, the second n-type nitride is used. Since current spreads in the semiconductor layer, light can be emitted from the entire surface, and light emission efficiency can be improved.

  Furthermore, according to the present invention, an electrode made of a transparent conductive film can be formed only on a part of the surface of the second n-type nitride semiconductor layer, so that light absorption by the electrode can be reduced. This can suppress a decrease in luminous efficiency. On the other hand, in the conventional light emitting device in which the uppermost layer of the laminate composed of the nitride semiconductor layers is a p-type nitride semiconductor layer, the current does not spread in the p-type nitride semiconductor layer, so that the electrode is p-type nitrided. It must be formed on the entire surface of the physical semiconductor layer, and the light emission efficiency is greatly reduced due to light absorption by the electrodes.

  The structure in which the pad electrode is formed on a part of the surface of the p-type nitride semiconductor layer is conventionally known. In such a structure, the current does not spread in the p-type nitride semiconductor layer, and the pad electrode is opaque. Since light is absorbed, the light extraction efficiency is low. On the other hand, according to the nitride semiconductor light emitting device of the present invention, since the electrode made of the transparent conductive film can be formed in, for example, a line shape or a network shape, from the region where the transparent conductive film is not formed, from the light emitting layer Light can be extracted directly, and light absorption by the electrode is also suppressed, and the light extraction efficiency is excellent.

  In addition, as described above, in the nitride semiconductor light emitting device of the present invention, an uneven shape is preferably imparted to the electrode forming side surface of the second n-type nitride semiconductor layer. By providing such a concavo-convex shape on the surface of the second n-type nitride semiconductor layer, multiple reflection of light inside the semiconductor layer can be suppressed or prevented, so that the light extraction efficiency can be further improved. . In the present invention, the thickness of the second n-type nitride semiconductor layer can be, for example, 10 to 3000 nm, and preferably 10 to 1000 nm. When unevenness is imparted to the surface of the second n-type nitride semiconductor layer, the thickness of the second n-type nitride semiconductor layer is desirably 300 nm or more. Even in the case where the second n-type nitride semiconductor layer is formed with a thickness of 300 nm or more, the second n-type nitride semiconductor layer has a low resistance, so that a voltage rise hardly occurs. On the other hand, in the conventional light emitting device in which the uppermost layer of the laminate composed of nitride semiconductor layers is a p-type nitride semiconductor layer, the p-type nitride semiconductor layer has a high resistance, and the voltage increases when the film thickness is large. In order to bring about an increase, the film thickness is usually about 200 nm or less. When the thickness of the p-type nitride semiconductor layer is reduced to about 200 nm or less, it is difficult to give the uneven shape to the surface of the p-type nitride semiconductor layer.

  Here, Japanese Unexamined Patent Application Publication No. 2006-13500 discloses a light-emitting element in which a concavo-convex shape is provided on the surface of a p-type nitride semiconductor layer. However, in such a structure, a region where the bottom surface of the concave portion reaches the light emitting layer is generated, and a leakage defect may occur. In the light-emitting element, since the uppermost layer of the stacked body made of nitride semiconductor layers is a p-type nitride semiconductor layer, an electrode must be formed on the entire surface of the p-type nitride semiconductor layer as described above. However, when an electrode is formed on a p-type nitride semiconductor layer having a concavo-convex shape, the area of the formed electrode is larger than when the p-type nitride semiconductor layer has a flat surface. The amount of light absorbed by the electrode is further increased.

  Further, as an element structure for improving light extraction efficiency, a structure in which a sapphire substrate surface is provided with an uneven shape and a nitride semiconductor layer is formed thereon has been known. This structure is a structure in which irregular reflection of light is caused at the interface between the sapphire substrate and the nitride semiconductor layer, a large amount of light is extracted to the sapphire substrate side, and light is extracted from the side surface of the sapphire substrate. However, in the light-emitting element having such a structure, when the paste material for die-bonding the sapphire substrate is a material that easily absorbs light, the light emitted to the sapphire substrate side is absorbed by the paste material on the back surface of the substrate to emit light. There is a problem that efficiency decreases. On the other hand, in the nitride semiconductor light emitting device of the present invention, since the light extraction efficiency on the device surface side (the side opposite to the substrate) is very high, it is not necessary to provide unevenness on the substrate surface and extract light from the side surface of the substrate. . Then, according to the nitride semiconductor light emitting device of the present invention in which the device surface side is the light extraction surface, and the surface of the second n-type nitride semiconductor layer is provided with an uneven shape, the light is reflected at the interface between the substrate and the nitride semiconductor layer. Then, since the bounced light is well extracted outside through the uneven surface formed on the surface of the second n-type nitride semiconductor layer, extremely high light extraction efficiency can be obtained. Furthermore, in the nitride semiconductor light emitting device of the present invention in which the device surface side is the light extraction surface, there is no particular limitation on the paste material for die-bonding the substrate, and therefore, it is appropriately selected from materials having good thermal conductivity. It is possible.

  As described above, in the present invention, the electrode made of a transparent conductive film is preferably formed by sputtering. A lower resistance electrode can be formed by forming a transparent conductive film on the second n-type nitride semiconductor layer by sputtering. This is because i) the n-type nitride semiconductor layer is not adversely affected by plasma, and ii) according to the electrode formation method by sputtering, the electrode material atoms arrive at the semiconductor layer with high energy, so that the adhesion is higher. This is because the contact resistance is further reduced, iii) sputtering can form a denser and higher crystallinity film than vapor deposition, and therefore the sheet resistance of the transparent conductive film can be lowered.

  On the other hand, in the conventional light emitting device in which the uppermost layer of the laminate composed of nitride semiconductor layers is a p-type nitride semiconductor layer, when a transparent conductive film is to be formed on the p-type nitride semiconductor layer, Depending on the forming method, the resistance becomes high. For example, when a transparent conductive film is formed by sputtering, the surface of the p-type nitride semiconductor layer is exposed to plasma in the sputtering apparatus, resulting in a problem that the surface becomes high resistance and voltage increases. Resulting in.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these.

<Example 1>
The nitride semiconductor light emitting device shown in FIG. 1 was fabricated according to the following procedure. First, on a substrate 101 that is a sapphire substrate, a buffer layer (50 nm thick) made of Al _r Ga _1-r N (0 ≦ r ≦ 1), and a first n-type nitride semiconductor layer 102 that is an n-type GaN layer. (5 μm thickness), a light emitting layer 103 (100 nm thickness) including a barrier layer made of GaN and a well layer made of In _q Ga _1-q N (0 <q <1), a p-type AlGaN layer (30 nm thickness) and a p-type A p-type nitride semiconductor layer 104 made of a GaN layer (thickness of 200 nm) and a second n-type nitride semiconductor layer 105 (thickness of 0.2 μm) which is an n-type GaN layer were grown in this order.

Next, after forming a resist mask 201 having a shape as shown in FIG. 2, a recess having a depth to the extent that the first n-type nitride semiconductor layer 102 is exposed by dry etching using the resist mask is formed. Formed (mesa etching). FIG. 3 shows a schematic cross-sectional view of the nitride semiconductor light emitting device in the middle of manufacturing after the formation of the recess. Next, after forming a SiO ₂ layer with a thickness of 1 μm on the entire surface, a resist mask 301 having a shape as shown in FIG. 4 is formed, and a portion of the SiO ₂ layer where the resist mask 301 is not formed is etched. Removed. Thereby, the insulating layer 109 was formed. FIG. 5 shows a schematic cross-sectional view of the nitride semiconductor light-emitting element in the middle of manufacture after the insulating layer is formed. Thereafter, the resist mask 301 was removed.

  Next, after forming an ITO layer having a thickness of 200 nm on the entire surface by sputtering, a resist mask 601 having a shape as shown in FIG. 6 is formed, and etching is performed on a portion of the ITO where the resist mask 601 is not formed. Was removed. Thereby, an electrode 106 made of a transparent conductive film was formed. FIG. 7 shows a schematic cross-sectional view of a nitride semiconductor light-emitting element that is being manufactured after forming an electrode made of a transparent conductive film. Thereafter, the resist mask 601 was removed. Finally, after forming a resist mask for forming a pad electrode, Ti / Al / Ti / Al is vapor-deposited and lift-off is performed to form pad electrodes 107 and 108. The nitride semiconductor light emitting shown in FIG. An element was obtained.

  When the luminous efficiency of the obtained light emitting device was measured, the light extraction efficiency was improved by about 20% compared to the light emitting device having 0.5 μm thick Al instead of the ITO film as the electrode and having no current blocking portion. did.

<Example 2>
The nitride semiconductor light emitting device shown in FIG. 8 was fabricated according to the following procedure. First, in the same manner as in Example 1, a buffer layer (50 nm thick) made of Al _r Ga _1-r N (0 ≦ r ≦ 1) and a first n-type GaN layer are formed on a substrate 801 that is a sapphire substrate. An n-type nitride semiconductor layer 802 (5 μm thick), a light emitting layer 803 (100 nm thick) including a barrier layer made of GaN and a well layer made of In _q Ga _1-q N (0 <q <1), p-type AlGaN A p-type nitride semiconductor layer 804 including a layer (30 nm thickness) and a p-type GaN layer (200 nm thickness), and a second n-type nitride semiconductor layer 805 (0.2 μm thickness) which is an n-type GaN layer in this order. Grown up.

Next, after a resist mask 201 having a shape as shown in FIG. 2 is formed, the p-type nitride semiconductor layer 804 is etched halfway by dry etching using the resist mask. A recess having a depth to expose 804 was formed (see FIG. 8). The exposed surface of the p-type nitride semiconductor layer 804 has a high resistance due to the influence of plasma during dry etching. Therefore, even if an electrode or a pad electrode is formed from a transparent conductive film thereon, no current is injected from the exposed p-type nitride semiconductor layer 804. There is no need to form _two layers. Therefore, after the formation of the recess, the same steps as in Example 1 were performed except that the step of forming the SiO ₂ layer was omitted, and the nitride semiconductor light emitting device shown in FIG. 8 was fabricated.

  When the luminous efficiency of the obtained light emitting device was measured, the light extraction efficiency was improved by about 20% compared to the light emitting device having 0.5 μm thick Al instead of the ITO film as the electrode and having no current blocking portion. did. Further, in the nitride semiconductor light emitting device of this example, the current blocking portion is formed of a recess having a depth reaching the p-type nitride semiconductor layer 804 formed on the surface of the second n-type nitride semiconductor layer 805. Since the insulating layer is not provided, productivity is improved.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  101, 801 Substrate, 102, 802 First n-type nitride semiconductor layer, 103, 803 Light emitting layer, 104, 804 P-type nitride semiconductor layer, 105, 805 Second n-type nitride semiconductor layer, 106, 806 Electrode made of transparent conductive film, 107, 108, 807 pad electrode, 109 insulating layer.

Claims (7)

A nitride semiconductor light-emitting device including a first n-type nitride semiconductor layer, a light-emitting layer, a p-type nitride semiconductor layer, and a second n-type nitride semiconductor layer in this order,
An electrode made of a transparent conductive film formed on the second n-type nitride semiconductor layer;
A concave portion formed on the surface of the second n-type nitride semiconductor layer and having a depth reaching at least the light emitting layer side surface of the first n-type nitride semiconductor layer covers the bottom surface and the side surface of the concave portion. A current blocking portion formed by forming an insulating layer on
A nitride semiconductor light emitting device having:   2. The nitride semiconductor light-emitting element according to claim 1, wherein the electrode made of the transparent conductive film is formed on a part of the surface of the second n-type nitride semiconductor layer.   The nitride semiconductor light-emitting device according to claim 2, wherein the electrode made of the transparent conductive film has a single or a plurality of line shapes or a mesh shape.   The nitride semiconductor light-emitting element according to claim 1, wherein the electrode made of the transparent conductive film is formed by a sputtering method.   5. The nitride semiconductor according to claim 1, wherein at least a part of a surface of the second n-type nitride semiconductor layer on the side where the electrode made of the transparent conductive film is formed has an uneven shape. Light emitting element.   The nitride semiconductor light-emitting element according to claim 1, further comprising a wire bonding pad electrode connected to the electrode made of the transparent conductive film.   The nitride semiconductor light emitting device according to claim 6, wherein the pad electrode is formed on the current blocking portion.

Images