JP2002164575A - Nitride semiconductor light emitting device - Google Patents

Abstract

(57) [Problem] To provide a light emitting diode which can be used for a color laser printer, virtual reality, or the like and has a small spot size and can emit light in a single mode. SOLUTION: In a light-emitting diode having a p-type gallium nitride-based compound semiconductor layer on an active layer made of a gallium nitride-based compound semiconductor layer, the light-emitting diode has an opening for partially opening the upper surface of the p-layer. An insulating film was formed so as to cover the p-layer, and a transparent electrode which was in ohmic contact with the p-layer through the opening was formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a nitride semiconductor (I).
_{n x Al y Ga 1-xy} N, 0 ≦ x, 0 ≦ y, x + y ≦ 1)
In particular, the present invention relates to a nitride semiconductor light emitting device that can be used as a minute light source.

[0002]

2. Description of the Related Art In recent years, nitride semiconductor light emitting diodes (light emitting elements) capable of emitting blue or green light have been put to practical use as light sources for large displays and the like. However,
When these light-emitting diodes put to practical use for large displays are used, for example, as a small light source for virtual reality or the like, the spread of light is large and the characteristics are not sufficiently satisfactory.

Therefore, as a minute light source, an edge-emitting type light emitting diode which emits light from an end face has been studied. This edge-emitting light-emitting diode usually has a basic structure similar to that of a semiconductor laser device in which a light-emitting layer is sandwiched between p-type and n-type semiconductor layers having a wide band gap. Then, AlGaN
/ GaN / InGaN separated confinement heterostructure (SC
H) is used. Furthermore, in this edge-emitting light-emitting diode, the light-emitting layer is formed in a stripe shape, and light is emitted from the light-emitting layer exposed on the end face of the stripe shape, thereby enabling light emission with a small spot size. I have to.

[0004]

However, although the conventional edge-emitting light emitting diode can obtain light with a small spot size, the conventional edge-emitting light emitting diode is not only an end face of the light emitting layer but also an n-type semiconductor laminated on the substrate side with respect to the light emitting layer. Since light is emitted also from the end face of the layer, multi-mode light emission is caused, and there is a problem that a single spot having a sufficiently good near field cannot be obtained. For this reason, since the light emission of the conventional edge-emitting light emitting diode is not in a single mode, it cannot be used as a minute light source in the field of optical information processing or the like that requires single mode light.

Accordingly, an object of the present invention is to provide a light emitting diode which can be used in a color laser printer, virtual reality, or the like and has a small spot size and can emit light in a single mode.

[0006]

In order to achieve the above object, a nitride semiconductor light emitting device according to the present invention comprises a p-type gallium nitride compound semiconductor layer on an active layer comprising a gallium nitride compound semiconductor layer. An insulating film having an opening for partially opening the upper surface of the p layer is formed so as to cover the p layer, and the p layer is formed through the opening. And a transparent electrode in ohmic contact with the transparent electrode is formed. The nitride semiconductor light emitting device according to the present invention thus configured can concentrate current into the active layer located immediately below the opening through the transparent electrode, and thereby, Light can be emitted only from the active layer immediately below the portion, and the emitted light can be emitted, through the opening, into light having a spot diameter corresponding to the shape of the opening. Further, in the nitride semiconductor light-emitting device according to the present invention, light emitted from the active layer immediately below the opening propagates through the p-layer in the thickness direction and is output to the outside. p
The propagation distance in the layer can be extremely short, and single mode light emission is possible.

Further, in the nitride semiconductor light emitting device according to the present invention, it is preferable that an opaque film for blocking light is further formed on the insulating film.

[0008] In the nitride semiconductor light emitting device according to the present invention, it is preferable that a protrusion is formed in a part of the p layer, and the opening is formed so as to open the upper surface of the protrusion. Thus, the current can be more concentratedly injected into the active layer immediately below the opening, and the emitted light can be more concentrated and emitted, so that the emission output can be further increased.

In the nitride semiconductor light emitting device according to the present invention, a p-pad electrode connected to the transparent electrode may be formed on the insulating film or on the light-impermeable film.

Further, in the nitride semiconductor light emitting device according to the present invention, the active layer and the p layer formed on the active layer may be formed of an n-type gallium nitride-based compound semiconductor layer formed on a substrate. An n-electrode that is in ohmic contact with the n-layer may be formed on the n-layer excluding a part thereof, and in this case, the n-electrode may be formed so as to emit light uniformly. The electrode is preferably formed so as to surround the transparent electrode.

Further, in the nitride semiconductor light emitting device according to the present invention, it is preferable that a reflection film is formed on the lower surface of the substrate, so that emitted light can be output more effectively. .

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A light emitting diode for a micro light source according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of the light emitting diode of the present embodiment, and FIG. 2 is a sectional view taken along line AA ′ of FIG. The light emitting diode of the present embodiment includes an n layer 101 formed of one or more gallium nitride based compound semiconductor layers formed on a substrate 1 with a buffer layer 2 interposed therebetween,
A light emitting diode having an active layer 7 formed on a layer 101 and a p-layer 102 made of one or more gallium nitride-based compound semiconductor layers, characterized by the following configuration.

That is, in the light emitting diode of the present embodiment, the opening 10 for opening a part of the upper surface of the p-layer 102 is provided.
An insulating film 10 having a is formed so as to substantially cover the p layer 102. Then, the transparent electrode 21 which is in ohmic contact with the p-layer 102 through the opening 10a formed in the insulating film 10 is formed. With such a configuration, in the light emitting device of the present embodiment, current can be injected from the transparent electrode 21 to the active layer 7 located immediately below the opening 10a through the opening 10a. Light can be emitted only in the active layer immediately below the opening 10a into which the current is injected and in the vicinity thereof. Further, in the light emitting diode of the present embodiment, the transparent electrode 2 is used as a p-side ohmic electrode that makes ohmic contact with the p layer 102 through the opening 10a.
Since 1 is used, light emitted in the active layer immediately below the opening 10a and in the vicinity thereof can be emitted through the transparent electrode 21.

Here, in the present invention, the diameter of the opening 10a can be arbitrarily set in accordance with the required spot diameter.
Preferably, it is set to 0.5 μm or more and 20 μm or less.

As described above, in the light emitting device of the present embodiment, the current is injected to a part of the active layer 7 by the insulating film 10 having the opening 10a, and the active layer and the active layer immediately below the opening 10a are formed. Since light emitted in the vicinity is emitted through the opening 10a, light having a spot size corresponding to the shape of the opening 10a can be emitted. Also,
In a conventional edge-emitting light emitting diode, for example, light emitted at a position distant from the end face of the active layer is guided and emitted so as to spread the active layer in the plane, so that single-mode light is emitted. Although it is difficult to obtain, in the light emitting element of the present embodiment, the light emitted from the active layer 7 is emitted in the thickness direction of the p layer 102, so that the light emitted from the active layer 7 is The light is emitted to the outside without being guided substantially inside, and single-mode light can be obtained.

In the light emitting diode of the present embodiment, as a more preferable form, as shown in FIG.
02, a columnar projection 30 is formed, and the projection 3
The opening 10a is formed so as to open the upper surface of the projection 0, and the transparent electrode 21 is formed so as to make ohmic contact with the upper surface of the projection 30. Thereby, as compared with the case where the protrusion 30 is not formed, the active layer 7 just below the opening 10a is formed.
Current can be more concentratedly injected into a part of the light, and the emitted light can be more concentrated and emitted.
The light emission output can be further increased. In the present embodiment, the p-layer 102 is composed of the p-side multilayer film layer 8 and the p-type contact layer 9, and the projection 30 is formed around the p-layer 1.
02 is formed by etching partway through the p-side multilayer film layer 8.

Further, in the light-emitting diode of the present embodiment, as a more preferred embodiment, an opaque film 11 for blocking light is further formed on the insulating film 10 so that the emitted light can be emitted from portions other than the opening 10a. Prevents leakage from parts. Further, in the light emitting diode of the present embodiment, as a more preferable embodiment, a reflection film 12 is formed on the lower surface of the substrate 1 so that emitted light can be more efficiently output through the opening 10a. I have.

Next, a detailed configuration of the light emitting diode of the present embodiment and a method of manufacturing the same will be described. In this manufacturing method, for example, on the C surface of the substrate 1 made of sapphire,
The buffer layer 2 is grown, and the undoped GaN layer 3 is grown on the buffer layer 2. This buffer layer 2 is a buffer layer between the substrate 1 made of a material different from the gallium nitride-based compound semiconductor and the gallium nitride-based compound semiconductor, and is preferably grown at a relatively low temperature at which a good buffering effect is obtained. It is formed using GaN. The undoped GaN layer 3 is formed to grow an n-type or p-type gallium nitride-based compound semiconductor layer grown thereon with good crystallinity, and is usually grown at a higher temperature than the buffer layer 2. .

Next, an n-type contact layer 4 is grown on the undoped GaN layer 3. This n-type contact layer 4
Is a layer for forming an n-electrode, and is preferably formed of Si-doped GaN in order to obtain good ohmic contact with the n-electrode. Then, an n-side cladding layer is grown on the n-type contact layer 4. In a preferred embodiment of the light emitting diode of the present embodiment, an n-side first multilayer film layer 5 composed of three layers of an undoped GaN layer, a Si-doped GaN layer, and an undoped GaN layer can improve electrostatic withstand voltage. Is used to form the n-side cladding layer.

Next, in the light emitting device of the present embodiment, as a preferred mode, an undoped GaN layer and an undoped In
An n-side second multilayer film layer 6 which is a multilayer film having a super lattice structure composed of a GaN layer is grown. Then, an active layer 7 made of a gallium nitride-based compound semiconductor is grown on the n-side second multilayer film layer 6. The active layer 7 is made of an InGaN layer or InGaN
It is preferable to comprise a layer, more preferably,
It is preferable to have a single or multiple quantum well structure including an InGaN well layer. In the case of a single or multiple quantum well structure including an InGaN well layer, the barrier layer can be made of InGaN or GaN having a smaller In ratio than the well layer.

Next, a p-side cladding layer is grown on the active layer 7. In a preferred embodiment of the light emitting diode of the present embodiment, the p-side cladding layer is constituted by a p-side multilayer film layer 8 having a superlattice structure composed of a Mg-doped p-type AlGaN layer and a Mg-doped InGaN layer. ing. Subsequently, a p-type contact layer 8 made of p-type GaN doped with Mg is grown.

After each semiconductor layer is grown as described above,
The etching is performed until the n-side contact layer 4 is exposed (partially in the n-side contact layer 4) except for a part including a light emitting portion (hereinafter, referred to as a pn laminated portion). Here, in the light emitting element of the present embodiment, as shown in FIG.
The laminated portion includes a columnar light emitting portion and a p-pad electrode forming portion in which the light emitting portion is connected to one corner. Note that the light emitting portion is not limited to the columnar shape, and may be, for example, a rectangular column shape. However, the position where the light emitting portion is formed is preferably substantially at the center of the substrate as shown in FIG.

Subsequently, the portions other than the convex portions 30 in the light emitting portion are etched to the middle of the p-side multilayer film layer 8 so that the columnar convex portions 30 are formed in the light emitting portion. Next, the insulating film 10 is formed so as to cover the entire pn laminated portion except for the upper surface of the protrusion 30, and the light-impermeable film 11 is formed on the insulating film 10. Here, the insulating film 10 can be used as long as it is an electric insulating material, for example, ZrO ₂ , SiO ₂ , Si
N, Al ₂ O ₃ , AlN, Ta ₂ O ₅ , Nb ₂ O ₅ , Hf
It can be formed using various materials such as O ₂ and TiO ₂ , and its thickness is preferably set in the range of 50 to 5000 °.

The light-impermeable film 11 can be used as long as it does not transmit light, but is preferably Rh, RhO, N
i, Cr, RuO, a metal such as Cu, or a metal oxide thereof, is used, and the film thickness is preferably 50 to 1000
The angle is set in the range of Å, more preferably in the range of 200 to 1000Å.

Next, a transparent electrode 21 which is in ohmic contact with the upper surface of the projection 30 is formed. The transparent electrode 21 is made of Au, P, which is a material capable of making ohmic contact with the p-type nitride semiconductor layer.
t, Ni, Al, W, In, Cu, Ag, Ir, Pd,
Metals such as Rh, Ti, Co, Sn, Pb or their 2
More than one kind of alloys or their metal oxides can be constituted as a single layer or a multilayer, and their film thickness is 0.0
A transparent electrode is obtained by adjusting the thickness to 01 to 1 μm. The following materials (1) to (5) are preferably used as the transparent electrode 21. (1) Ni (80Å) / Au (40-160Å) (2) Pd (40Å) / Au (40Å) (3) Pd (30Å) / Pt (30Å) / Au (20Å) (4) Ni (20〜) 80Å) / ITO (100-2000Å) (5) Ni (20-80Å) / Au (10-50Å) / ITO (100-
2000Å)

Next, an n-electrode 23 in ohmic contact with the n-type contact layer 4 is formed on the n-type contact layer 4 at a distance from the pn laminated portion. Here, it is preferable that the n-electrode 23 is formed so as to surround at least the light-emitting portion, whereby the resistance between the transparent electrode 21 and the n-electrode can be reduced, and the luminous efficiency can be increased. In addition, by forming the n-electrode 23 around the light emitting portion, it is possible to inject a current almost uniformly into the light emitting portion of the active layer, thereby enabling uniform light emission. Further, the n-electrode 23 is not particularly limited as long as it is an electrode material that can make ohmic contact with the n-type contact layer 4. For example, Ti, Al, Ni, Au, W, V
At least one metal material selected from the group consisting of Ti / Al, W / Al / W / Au, W
/ Al / W / Pt / Au. Further, the film thickness of the n-electrode 23 is preferably 2000 to 5 mm.
It is set in the range of μm, more preferably in the range of 5000 ° to 1.5 μm.

Next, as shown in FIG.
Is formed on the light-impermeable film 11, and an n-pad electrode 24 is formed on a part of the n-electrode 23. As the p and n pad electrodes, wires and p
(n) There is no particular limitation as long as it has good adhesiveness to the electrode, but preferably, a two-layer structure of a first layer // third layer selected from the following materials, or a first layer / second layer / The third layer has a three-layer structure. (1) First layer: at least one selected from Ni, Cu, Rh, and Ru. (2) Second layer: at least one selected from Ti, W, Pt, Ta, and Mo. (3) Third layer Eye: Au. More preferably, Ni / Ti / Au, Ni / Au, Cu
/ Pt / Au, Ni / Pt / Au, and the film thickness is 1
Set to 000 ° to 3 μm.

In the light emitting device of the embodiment configured as described above, the current can be injected to a part of the active layer 7 by the insulating film 10 having the opening 10a. Since light can be emitted only in the active layer immediately below the opening 10a and in the vicinity thereof, light can be emitted efficiently. Further, since the light emitted in the restricted area is emitted through the opening 10a, it is possible to emit single mode light having a spot size corresponding to the shape of the opening 10a.

Modified example. Hereinafter, modified examples according to the present invention will be described. FIG. 3 is a cross-sectional view showing a configuration of a light emitting diode according to a modification according to the present invention. The light emitting diode of this modified example is different from the light emitting diode of the embodiment in that the p layer 1
The configuration is the same as that of the light emitting diode of the embodiment, except that the light emitting diode is configured without forming the convex portion 30 on 02. In the light emitting diode of the modified example configured as described above,
Since the current can be injected into a part of the active layer 7 by the insulating film 10 having the opening 10a, the light can be efficiently emitted, and the light emitted in the limited area can be opened. Since the light is emitted through the portion 10a,
A single-mode light having a spot size corresponding to the shape of the opening 10a can be emitted.

[0030]

Embodiments of the present invention will be described below. The present invention is not limited to the following embodiments. Embodiment 1 FIG. (Substrate 1) A substrate made of sapphire (C-plane) is MOVP
The substrate is set in the reaction vessel of E, and while flowing hydrogen, the temperature of the substrate is increased to 1050 ° C. to clean the substrate.

(Buffer Layer 2) Subsequently, the substrate temperature is set to 51
The temperature was lowered to 0 ° C., and hydrogen was used as a carrier gas, and ammonia and TMG (trimethylgallium) were used as source gases.
A buffer layer 2 made of GaN is grown thereon with a thickness of about 200 Å. (Undoped GaN layer 3) After growth of buffer layer 2, TMG
Only stop and raise the temperature to 1050 ° C. 105
When the temperature reaches 0 ° C., the undoped GaN layer 3 is grown to a thickness of 1 μm using TMG and ammonia gas as the source gas.

(N-type contact layer 4) Subsequently, at 1050 ° C.
Similarly, an n-type contact layer made of GaN doped with 4.5 × 10 ¹⁸ / cm ^{3 of} Si is grown to a thickness of 3 μm using TMG as a source gas, ammonia gas, and silane gas as an impurity gas. (N-side first multilayer film layer 5) Then, only the silane gas is stopped and 1
At 050 ° C., an undoped GaN layer is grown to a thickness of 3000 Å using TMG and ammonia gas, and then silane gas is added at the same temperature to add Si to 4.5.
A × 10 ¹⁸ / cm ³ doped GaN layer is grown to a thickness of 300 Å, followed by stopping only silane gas, and growing an undoped GaN layer to a thickness of 50 Å at the same temperature to form a total of three layers. Film thickness 3350
The angstrom n-side first multilayer film layer 5 is grown.

(N-side second multilayer film layer 6) Next, at the same temperature, a second nitride semiconductor layer made of undoped GaN is grown at 40 Å, and then the temperature is set to 800 ° C., and TMG, TMI Then, a first nitride semiconductor layer made of undoped InGaN is grown to 20 angstroms using ammonia. Repeat these operations,
Of a superlattice structure formed by alternately laminating 10 layers of nitride semiconductor layer + first nitride semiconductor layer in this order, and finally growing a second nitride semiconductor layer of GaN by 40 Å. The n-side second multilayer film layer 6
It is grown to a thickness of 40 angstroms.

(Active Layer 7) Next, a barrier layer made of undoped GaN is grown to a thickness of 250 Å, and then the temperature is set to 800 ° C. to form a well layer made of undoped InGaN using TMG, TMI and ammonia. It is grown to a thickness of 30 angstroms. Then, the barrier layers are formed in the order of barrier + well + barrier + well.
The active layer 7 having a multiple quantum well structure with a total thickness of 1650 Å is grown by alternately stacking the layers and five well layers.

(P-side multilayer film layer 8) Next, at a temperature of 1050 ° C.
Using TMG, TMA, ammonia, Cp ₂ Mg (cyclopentadienyl magnesium), and adding Mg to 1 × 10 ²⁰
/ Cm ³ -doped p-type AlGaN third nitride semiconductor layer is grown to a thickness of 40 Å, then the temperature is set to 800 ° C., and TMG, TMI, ammonia, Cp ₂ Mg and Mg A fourth nitride semiconductor layer made of InGaN doped with × 10 ²⁰ / cm ³ is grown to a thickness of 25 Å. These operations are repeated, and five layers are alternately stacked in the order of the third nitride semiconductor layer + the fourth nitride semiconductor layer, and finally, the third nitride semiconductor layer is grown to a thickness of 40 Å. A p-type multilayer clad layer 8 composed of a multilayer film having a superlattice structure is grown to a thickness of 365 angstroms.

(P-type contact layer 9) Subsequently, at 1050 ° C.
And using TMG, ammonia, and Cp2Mg,
A p-type contact layer 8 made of p-type GaN doped with × 10 ²⁰ / cm ³ is grown to a thickness of 700 Å. After completion of the reaction, the temperature is lowered to room temperature, and the wafer is annealed at 700 ° C. in a reaction vessel in a nitrogen atmosphere to further reduce the resistance of the p-type layer.

Next, as shown in FIG. 1, etching is performed until the n-side contact layer 4 is exposed while leaving the pn laminated portion.
Subsequently, in order to form the columnar convex portion 30, a portion other than the convex portion 30 in the pn laminated portion is etched halfway of the p-side multilayer film layer 8. Here, in the first embodiment, the diameter of the columnar projection 30 is set to 4 μm. (Insulating Film 10, Opaque Film 11) Next, an insulating film 10 made of ZrO ₂ having an opening 10a on the upper surface of the convex portion 30 and covering the entire pn laminated portion except for the upper surface of the convex portion 30. 10
Then, an opaque film 11 made of Rh is formed on the insulating film 10 to a thickness of 1000 mm.

Next, the transparent electrode 2 made of Ni (80 °) / Au (150 °) and in ohmic contact with the upper surface of the projection 30 is formed.
Form one. Subsequently, W / A is formed on the n-type contact layer 4.
An n-electrode 23 having a four-layer structure of 1 / W / Pt / Au and in ohmic contact with the n-type contact layer 4 is formed.

Next, as shown in FIG.
Is formed on the light-impermeable film 11, and an n-pad electrode 24 is formed on a part of the n-electrode 23. Here, the p pad electrode and the n pad electrode are Ni (1
000Å) / Ti (1000Å) / Au (8000Å). Finally, a reflective film made of Al is formed on the lower surface of the substrate to a thickness of 3000 ° by sputtering.

The light emitting diode of Example 1 manufactured as described above emitted single mode light with a spot diameter of 4 μm and a light emission output of 200 μW under a forward current of 0.5 mA.

Embodiment 2 FIG. The light emitting diode according to the second embodiment of the present invention is different from the light emitting diode according to the first embodiment in that the p-layer 102 is not provided with a protrusion.
Otherwise, the configuration is the same as in the first embodiment. In the light emitting diode of the second embodiment, the opening 10a formed in the insulating film 10 has a diameter of 4 μm as in the first embodiment. That is, the light emitting diode of the second embodiment is different from that of FIG.
It is configured as shown in FIG. The light emitting diode of Example 2 configured as described above emitted single mode light with a spot diameter of 4 μm and a light emission output of 150 μW under a forward current of 0.5 mA.

Hereinafter, in Example 2, when the diameter of the light emitting portion (opening 10a) is sequentially changed, p
Table 1 shows current values and light emission outputs when a voltage of 3 V was applied between the electrode and the n-electrode as Examples 3 to 5. Table 1 In Table 1, the light emitting diode shown as a comparative example was evaluated by forming a transparent electrode on almost the entire surface of the p-type contact layer without forming the insulating film 10.
As is clear from Table 1, the light emission output per unit area is substantially the same, and the area of the light emitting portion and the light emission output are almost proportional.

As described above in detail with reference to the embodiments and the examples, the light emitting diode according to the present invention is obtained by injecting a current by restricting a part of the active layer by the insulating film 10 having the opening 10a. Then, a part of the injected active layer emits light, and the emitted light is output through a transparent electrode formed in the opening. Thereby, the diameter (shape) of the opening
Can output a single-mode light having a spot diameter corresponding to. Therefore, by setting the diameter (shape) of the opening corresponding to the required spot diameter, it is possible to output single-mode light having a desired spot diameter.

[0044]

As described above in detail, in the nitride semiconductor light emitting device according to the present invention, the insulating film having an opening for partially opening the upper surface of the p-layer covers the p-layer. And the transparent electrode that is in ohmic contact with the p-layer through the opening is formed, so that the current is concentrated into the active layer located immediately below the opening through the transparent electrode. Can be emitted only in the active layer immediately below the opening, and the emitted light is transmitted through the opening to a single mode light having a spot diameter corresponding to the shape of the opening. Can be emitted. Therefore, according to the present invention, it is possible to provide a light-emitting diode having a small spot size and capable of emitting light in a single mode, and this light-emitting diode can be used for a color laser printer, virtual reality, and the like.

[Brief description of the drawings]

FIG. 1 is a plan view showing a configuration of a light emitting diode according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line A-A 'of FIG.

FIG. 3 is a cross-sectional view illustrating a configuration of a light emitting diode according to a modification of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... board | substrate, 2 ... buffer layer, 3 ... undoped GaN layer, 4 ... n-type contact layer, 5 ... n side 1st multilayer film layer, 6 ... n side 2nd multilayer film layer, 7 ... active layer, 8 ... p Side multilayer film layer, 9: p-type contact layer, 10: insulating film, 10a: opening, 11: light-impermeable film, 12: reflective film, 30: convex portion, 21: transparent electrode, 22: p pad electrode 23 ... n electrodes, 24 ... n pad electrodes.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4M104 AA04 AA09 BB02 BB04 BB05 BB06 BB07 BB08 BB09 BB13 BB14 BB18 CC01 FF13 GG04 5F041 AA14 CA05 CA12 CA34 CA40 CA57 CA65 CA74 CA82 CA83 CA84 CA88 CA92 CB13 CB16

Claims (7)

[Claims] 1. A light emitting diode comprising a p-type gallium nitride-based compound semiconductor layer and a p-layer formed on an active layer made of a gallium nitride-based compound semiconductor layer, wherein an opening for partially opening an upper surface of the p-layer is provided. A nitride semiconductor light-emitting device, wherein an insulating film having the following formula is formed so as to cover the p-layer, and a transparent electrode that is in ohmic contact with the p-layer through the opening is formed. 2. The nitride semiconductor light emitting device according to claim 1, further comprising an opaque film for blocking light, formed on said insulating film. 3. The nitride semiconductor light emitting device according to claim 1, wherein a projection is formed in a part of said p layer, and said opening is formed so as to open an upper surface of said projection. 4. The nitride according to claim 1, wherein a p-pad electrode connected to the transparent electrode is formed on the insulating film or on the light-impermeable film. Object semiconductor light emitting device. 5. The active layer and a p-layer formed on the active layer are provided on a part of an n-layer made of an n-type gallium nitride-based compound semiconductor layer formed on a substrate, and The nitride semiconductor light-emitting device according to claim 1, wherein an n-electrode in ohmic contact with the n-layer is formed on the n-layer excluding the portion. 6. The nitride semiconductor light emitting device according to claim 5, wherein said n-electrode is formed so as to surround said transparent electrode. 7. The nitride semiconductor light emitting device according to claim 5, wherein a reflection film is formed on a lower surface of said substrate.