JP3207773B2 - Compound semiconductor light emitting device and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a compound semiconductor light emitting device for extracting light from a compound semiconductor layer, and more particularly to a compound semiconductor light emitting device using a transparent electrode and a method for manufacturing the same.

[0002]

2. Description of the Related Art Semiconductor light emitting devices have been actively developed for some time, but it has been very difficult to emit light having a high light emission intensity such as blue or green. So recently,
A light-emitting element using a GaN-based compound semiconductor material such as GaN, InGaN, and GaAlN is a blue light-emitting diode (L
ED) and laser diodes (LD).

In this GaN-based compound semiconductor light emitting device, a compound semiconductor layer is grown on a sapphire substrate. Since the sapphire substrate is an insulating substrate, an electrode cannot be provided on the substrate side unlike a light emitting element using GaAs or the like. Therefore, it is necessary to form both the P-side electrode and the N-side electrode on the compound semiconductor growth layer side. Furthermore, since the sapphire substrate has a light-transmitting property with respect to the emission wavelength, the sapphire substrate is often mounted with the electrode side down and light is extracted from the sapphire substrate side.

FIG. 12 is a sectional structural view of a conventional GaN-based compound semiconductor light emitting device. On the sapphire substrate 1,
The electrodes 9, 17 are facing down. Sapphire substrate 1
Below the GaN buffer layer 3, the n-type GaN layer 5, the p-type G
The aN layer 7 has grown. An N-side electrode 9 is formed on the n-type GaN layer 5, which is exposed by partially removing the p-type GaN layer 7, and a P-side electrode 17 is formed on the p-type GaN layer 7. The P-side electrode 17 and the N-side electrode 9 are mounted on a lead frame 53 with a conductive adhesive material 55 such as a silver paste.

In a GaN-based compound semiconductor light-emitting device having such a structure, as shown in FIG.
A current flows from the aN layer 7 to the N-side electrode 9 and the n-type Ga
Light emitted at the junction between the N layer 5 and the p-type GaN layer 7 is extracted through the sapphire substrate 1.

On the other hand, GaAs, AlGaAs, AlGa
Light emitting devices using a GaAs compound semiconductor material such as InP are also widely used as red or green light emitting diodes. This GaAs-based compound semiconductor light emitting device is composed of GaAs
A plurality of AlGaInP layers are stacked on an s substrate, and one of a P-side electrode and an N-side electrode is placed on the AlGaInP layer side.
The other is formed on the back surface of the GaAs substrate.

In order to extract light emitted from the active layer from the AlGaInP layer side without being blocked by the electrodes, a current diffusion layer for diffusing current and injecting the current into the active layer is provided.

FIG. 13 is a sectional view of a conventional GaAs compound semiconductor light emitting device. On an n-type GaAs substrate 31, an n-type GaAs buffer layer 33 and an n-type AlGaInP
Clad layer 35, AlGaInP active layer 37, p-type Al
A GaInP cladding layer 39, a p-type AlGaAs current diffusion layer 57, and a p-type GaAs contact layer 43 are grown. A p-side electrode 49 is formed on the p-type GaAs contact layer 43.
However, an N-side electrode 51 is formed on the back surface of the n-type GaAs substrate 31.

In the GaAs compound semiconductor light emitting device having such a structure, the current flowing from the P-side electrode 49 is p-type A type.
AlGaInP diffused by the lGaAs current diffusion layer 57
The AlGaInP active layer 37 is injected into the active
Light emitted at the junction surface with the AlGaInP cladding layer 39 is extracted from the P-side electrode 49 side.

[0010]

However, FIG.
In the conventional GaN-based compound semiconductor light-emitting device shown in (1), the conductive adhesive material 55 easily spreads between the lead frames 53 and the pn junction 59, and a failure due to a short between electrodes or a short between junctions has occurred. In order to avoid this, it is conceivable to increase the element size and widen the interval between the lead frames 53. However, there is a disadvantage that the number of elements that can be obtained from one wafer decreases and the production cost increases. In addition, there is a problem that mass mounting is lacking because the mounting position accuracy between the lead frame 53 and the element requires high accuracy.

On the other hand, in the conventional GaAs compound semiconductor light emitting device shown in FIG. 13, if the thickness of the p-type AlGaAs current diffusion layer 57 is insufficient, the current is not sufficiently diffused.
Current is injected only into the AlGaInP active layer 37 immediately below the P-side electrode 49, and the emitted light is blocked by the P-side electrode 49 and cannot be sufficiently extracted. If current spreading is insufficient,
Uniform light emission is not obtained, external quantum efficiency is significantly reduced,
There is a drawback that sufficient light emission power cannot be obtained. In order to prevent this, the thickness of the p-type AlGaAs current diffusion layer 57 needs to be increased, so that there is a problem that the productivity cost is increased.

Further, as a conventional example, Japanese Patent Application Laid-Open No. 7-1310
Although a combination of a metal transparent conductive film exhibiting ohmic junction characteristics and a transparent conductive film having a maximum transmittance in the vicinity of the light wavelength as in the case of 70 has also been proposed, it requires mesa etching and protects the pn junction protection. Is insufficient and unreliable.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a compound semiconductor light emitting device which has a low production cost, is suitable for mass production, and has sufficient light emission power, and its production. Is to provide a way.

[0014]

Means for Solving the Problems To achieve the above object, a first aspect of the present invention is a compound semiconductor light emitting device for extracting light from a GaN-based compound semiconductor layer, comprising a sapphire substrate, A first conductivity type GaN layer grown on a sapphire substrate, a second conductivity type GaN layer grown on the first conductivity type GaN layer, and insulated from the second conductivity type GaN layer; A first electrode formed on the second conductive type GaN layer, an insulating film formed in a partial region on the second conductive type GaN layer, and a first electrode formed on a region other than the insulating film forming region on the second conductive type GaN layer The second conductivity type GaN
A metal thin film electrode containing a dopant of the same conductivity type as the layer, a transparent electrode formed on the metal thin film electrode, and a second electrode formed on the insulating film and in contact with at least a part of the transparent electrode.
And an electrode.

A second aspect of the present invention is a method of manufacturing a compound semiconductor light emitting device for extracting light from a GaN-based compound semiconductor layer, comprising the steps of: growing a first conductivity type GaN layer on a sapphire substrate; Growing a second conductivity type GaN layer on the conductivity type GaN layer, forming a first electrode insulated from the second conductivity type GaN layer on the first conductivity type GaN layer, Forming an insulating film in a partial region on the second conductivity type GaN layer, and forming the second conductivity type GaN on a region other than the insulating film formation region on the second conductivity type GaN layer.
Forming a metal thin film electrode containing the same conductivity type dopant as the layer, forming a transparent electrode on the metal thin film electrode, and forming a second electrode in contact with at least a part of the transparent electrode on the insulating film. Forming step.

According to the first and second aspects, it is not necessary to extract light from the sapphire substrate side, and light can be extracted from the GaN layer side on which the electrodes are formed. Since both the first and second electrodes can be formed on the GaN layer side, the mounting position can be easily adjusted and the productivity can be improved. Since the insulating film is provided under the second electrode, light emission does not occur immediately below the second electrode, and an impact on the second electrode at the time of wire bonding is reduced, thereby greatly improving the element yield.

A third feature of the present invention is a compound semiconductor light emitting device for extracting light from a GaN-based compound semiconductor layer,
A sapphire substrate, and a first substrate grown on the sapphire substrate.
A conductive type GaN layer, a second conductive type GaN layer having a semi-insulating layer grown on the first conductive type GaN layer, and insulated from the second conductive type GaN layer, on the first conductive type GaN layer. A metal thin-film electrode formed on a layer other than the semi-insulating layer of the second conductivity type GaN layer and containing a dopant of the same conductivity type as the second conductivity type GaN layer; A transparent electrode formed on the thin-film electrode;
a second electrode formed on the semi-insulating layer of the aN layer and in contact with at least a part of the transparent electrode.

A feature of the fourth invention is a method of manufacturing a compound semiconductor light emitting device for extracting light from a GaN-based compound semiconductor layer, wherein a step of growing a first conductivity type GaN layer on a sapphire substrate, Growing a second conductivity type GaN layer having a semi-insulating layer on the conductivity type GaN layer, and forming a first electrode insulated from the second conductivity type GaN layer on the first conductivity type GaN layer; Forming a metal thin film electrode containing the same conductivity type dopant as the second conductivity type GaN layer on a layer other than the semi-insulating layer of the second conductivity type GaN layer; and forming a transparent electrode on the metal thin film electrode. Forming and forming a second electrode in contact with at least a part of the transparent electrode on the semi-insulating layer of the second conductivity type GaN layer.

According to the third and fourth inventions, the region under the second electrode of the second conductivity type GaN layer is a semi-insulating layer.
Since there is no need to form an insulating film on the second conductivity type GaN layer, productivity is improved. Below the second electrode is GaN of the second conductivity type
Since the layer is a semi-insulating layer, current is efficiently injected into the second conductivity type GaN layer via the transparent electrode and the metal thin film electrode, and sufficient light emission is possible.

According to a fifth aspect of the present invention, there is provided a compound semiconductor light emitting device for extracting light from a GaAs-based compound semiconductor layer, comprising: a first conductivity type GaAs substrate;
A plurality of AlGaInP layers stacked on a substrate, and a second conductivity type Ga formed on the uppermost layer of these AlGaInP layers.
An As layer, an insulating film formed in a partial region on the second conductivity type GaAs layer, and the second conductive film formed in a region other than the insulating film forming region on the second conductivity type GaAs layer. A metal thin-film electrode containing the same conductivity type dopant as the type GaAs layer, a transparent electrode formed on the metal thin-film electrode, a first electrode formed on the insulating film and in contact with at least a part of the transparent electrode, A second electrode formed on the back surface of the GaAs substrate of the first conductivity type.

A sixth feature of the present invention is a method of manufacturing a compound semiconductor light emitting device for extracting light from a GaAs compound semiconductor layer, wherein a plurality of layers of Al are formed on a first conductivity type GaAs substrate.
A step of stacking a GaInP layer;
Forming a second conductivity type GaAs layer on the uppermost layer of the P layer, forming an insulating film in a partial region on the second conductivity type GaAs layer, and forming the insulating film on the second conductivity type GaAs layer; Forming a metal thin-film electrode containing a dopant of the same conductivity type as the second conductivity-type GaAs layer in a region other than the film-forming region; and forming a transparent electrode on the metal thin-film electrode;
Forming a first electrode in contact with at least a part of the transparent electrode on the insulating film;
Forming a second electrode on the back surface of the substrate.

According to the fifth and sixth aspects of the present invention, since a thick current spreading layer is not required, productivity is improved and cost is reduced. Since there is an insulating film under the first electrode, current does not flow directly under the first electrode, and the second film passes through the transparent electrode and the metal thin film electrode.
It is efficiently injected into the conductive GaN layer. Therefore, the first
High-luminance light emission is possible except under the electrode.

A feature of the seventh invention is that in the fifth and sixth inventions, the insulating film is a first conductivity type AlGaInP film or a first conductivity type GaAs film.

According to the seventh aspect, GaAs of the second conductivity type is used.
On the layer, a first conductivity type AlGaI which is pn reverse junction with the layer
Since an nP film or a GaAs film is formed, productivity is improved by a similar manufacturing method.

According to an eighth aspect of the present invention, in the first to seventh aspects, the metal thin film electrodes are arranged in a plurality of islands.

According to the eighth aspect, since the metal thin-film electrodes can be dispersed and arranged in an island shape instead of a plate shape, the current flowing through the transparent electrode can be efficiently dispersed to the GaAs layer of the second conductivity type. can do.

[0027]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 are sectional structural views showing a method for manufacturing a GaN-based compound semiconductor light emitting device according to the first embodiment of the present invention.

First, a GaN buffer layer 3, an n-type GaN layer 5, and a p-type GaN layer 7 containing Mg as a p-type dopant are grown on a sapphire substrate 1 (FIG. 1).
(A)). Next, the p-type GaN layer 7 is patterned and etched by the PEP method to expose the n-type GaN layer 5. Further, patterning is performed using the PEP method, and Ti / Au or the like is vapor-deposited on the exposed n-type GaN layer 5,
An N-side electrode 9 insulated from the type GaN layer 7 is formed by a lift-off method. 700 ° C to make ohmic electrode
For 20 minutes (FIG. 1B).

Thereafter, an SiO ₂ film 11 serving as an insulating film is formed by a thermal CVD method (FIG. 2A). The SiO ₂ film 11 is patterned by the PEP method, leaving a partial region. In a region on the p-type GaN layer 7 where the SiO ₂ film 11 is not formed, a Mg / Ni
= 1 nm / 2 nm is deposited. Next, a 100 nm thick ITO (Indium Tin Oxide) transparent electrode 15 is formed by an RF sputtering method, and then lift-off is performed to form a metal thin film electrode 13 containing Mg which is the same p-type dopant as the p-type GaN layer 7. You. Metal thin film electrode 13 and p-type G
Annealing is performed at 500 ° C. for 10 minutes in order to improve the adhesion and ohmic properties with the aN layer 7 (FIG. 2).
(B)).

Further, patterning and etching are performed by the PEP method, and a P-side electrode 1 for a bonding pad in contact with a part of the ITO transparent electrode 15 is formed on the SiO ₂ film 11.
7 is formed of Ti / Au or the like. At this time, the SiO ₂ film 11 covering the N-side electrode 9 is also removed at the same time, and a metal such as Ti / Au is overcoated (FIG. 3).

As described above, in the first embodiment, the SiO ₂ film 11 serving as an insulating film is formed in a partial region on the p-type GaN layer 7 containing Mg as a p-type dopant. Further, a metal thin-film electrode 13 containing Mg, which is the same p-type dopant as the p-type GaN layer 7, and an ITO transparent electrode 15 are formed in a region on the p-type GaN layer 7 where the SiO ₂ film 11 is not formed. Have been. On the SiO ₂ film 11,
A bonding pad P-side electrode 17 that is in contact with a part of the ITO transparent electrode 15 is formed.

Since the ITO transparent electrode 15 contains Sn which is an n-type impurity, it cannot be generally formed on the p-type GaN layer 7. In the present invention, the p-type GaN layer 7 and the metal thin-film electrode 13 containing Mg, which is relatively easy to obtain ohmic, are formed with a thickness of 2 nm, which has a transmittance of 70% for emitted light. Further, in order to further reduce the sheet resistance of the metal thin film electrode 13, an ITO transparent electrode 15 having a thickness of 100 nm is formed.

Therefore, the operation of the metal thin film electrode 13 containing Mg can be easily performed without sacrificing ohmic properties.
The O transparent electrode 15 can be formed. Further, since the bonding pad P-side electrode 17 is formed in contact with a part of the ITO transparent electrode 15, the metal thin film electrode 13 containing Mg which is easily peeled can have sufficient strength for bonding.

As shown in FIG. 3, according to the GaN-based compound semiconductor light emitting device of the present invention, there is no need to extract light from the sapphire substrate 1 side, unlike the conventional case shown in FIG. Light emitted from the bonding surface between the p-type GaN layer 5 and the p-type GaN layer 7 can be extracted from the GaN layer side where the electrodes 9 and 17 are formed.

As a result, as shown in FIG. 4, the compound semiconductor light emitting device is mounted on the cup-type lead frame 19 and wire-bonded to the N-side electrode 9 to connect the P-side electrode 17 for the bonding pad and the P-side electrode terminal 21 to each other. The light collecting property can be improved by wire bonding.

The bonding pad P-side electrode 17
Is not formed directly on the ITO transparent electrode 15, but is formed on the SiO ₂ film 11 serving as an insulating film so as to be in contact with a part of the ITO transparent electrode 15. As a result, the current is diffused through the P-side ITO transparent electrode 15 and efficiently injected into the p-type GaN layer 7 through the metal thin-film electrode 13, and the impact at the time of wire bonding is alleviated and the element yield is reduced. Significantly improved.

Since the N-side electrode 9 and the P-side electrode 17 can be provided on the same surface of the n-type GaN layer 5, the mounting position can be easily adjusted and the productivity can be improved. Furthermore, IT
Annealing in the state where the O transparent electrode 15 is formed lowers the controllability of the metal film thickness in the electrode process, in which the metal thin film electrode 13 evaporates again and disappears or becomes thinner due to the annealing. Accordingly, deterioration of the IV characteristics of the light emitting element can be avoided.

The SiO ₂ film 11 and the metal thin film electrode 1
3, ITO transparent electrode 15, and P for bonding pad
The structure of the side electrode 17 is not limited to the structure shown in FIG.
As shown in (A) and (B), a structure in which the bonding pad P-side electrode 17 is in contact with both the metal thin film electrode 13 and the ITO transparent electrode 15 may be used.
What is necessary is just to touch a part of No. 5. FIG.
As shown in (C), a partial region layer of the p-type GaN layer 7 is made into a semi-insulating layer 23 (shaded portion in the figure), and a bonding pad P-side electrode 17 is formed on the semi-insulating layer 23. It is a good thing. According to this, since it is not necessary to form the SiO ₂ film 11, productivity is improved.

Further, the shape of the metal thin film electrodes 13 does not necessarily have to be plate-like, and may be arranged in a plurality of islands, for example, as shown in FIG. By disposing the metal thin-film electrodes 13 in a plurality of islands in this manner, the current flowing through the ITO transparent electrode 15 can be efficiently dispersed to the p-type GaN layer 7.

Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. 7 to 9 are sectional structural views showing a method for manufacturing a GaAs-based compound semiconductor light emitting device according to the second embodiment of the present invention.

First, an n-type G substrate is placed on an n-type GaAs substrate 31.
aAs buffer layer 33, n-type AlGaInP cladding layer 35, AlGaInP active layer 37, p-type AlGaInP
A cladding layer 39 and a p-type GaAs contact layer 41 containing Zn which is a p-type dopant are sequentially laminated (FIG. 7).
(A)). A current block layer 43 of n-type AlGaInP or n-type GaAs is formed in a partial region on the p-type GaAs contact layer 41 (FIG. 7B).

Next, a metal thin-film electrode 45 containing Zn, which is the same p-type dopant as the p-type GaAs contact layer 41, is formed in a region on the p-type GaAs contact layer 41 where the current blocking layer 43 is not formed. AuZn = 5 nm, 4
Formed by sintering at 30 ° C. for 15 minutes (FIG. 8)
(A)). Further, an ITO transparent electrode 47 is formed on the current block layer 43 and the metal thin film electrode 45 (FIG. 8).
(B)).

Finally, the ITO on the current block layer 43
After the transparent electrode 47 is removed by etching, a P-side electrode 49 that is in contact with a part of the ITO transparent electrode 47 is formed.
An N-side electrode 51 is formed on the back surface of the n-type GaAs substrate 31 (FIG. 9).

As described above, in the second embodiment, the P-side electrode 4
9, a current blocking layer 43 of n-type AlGaInP or n-type GaAs, which is a pn reverse junction with this, is formed.
The current is prevented from flowing just below the side electrode 49.
Further, since the P-side electrode 49 is in contact with a part of the ITO transparent electrode 47, as shown in FIG.
And is efficiently injected into the AlGaInP active layer 37. As a result, uniform light emission can be obtained and the emitted light can be efficiently extracted at the joint surface between the AlGaInP active layer 37 and the p-type AlGaInP cladding layer 39.

Further, since the current block layer 43 is formed of a GaAs-based compound semiconductor, it can be formed by a similar manufacturing method and has a thick p-type AlGaAs shown in FIG.
Since the s current diffusion layer 57 is unnecessary, the productivity is improved,
Lower costs.

The structures of the current blocking layer 43, the metal thin-film electrode 45, the ITO transparent electrode 47, and the P-side electrode 49 are not limited to the structure shown in FIG. 9, but are shown in FIGS.
As shown in FIG.
The structure may be in contact with both of the transparent electrodes 47, and it is sufficient that the structure is in contact with at least a part of the ITO transparent electrode 47.

The current blocking layer 43 is made of n-type AlG
It does not need to be aInP or n-type GaAs.
It may be formed of an insulating film such as O ₂ . In this case, a structure as shown in FIGS. Further, the shape of the metal thin film electrodes 45 does not necessarily have to be a plate shape, and may be arranged in a plurality of island shapes as shown in FIG. 6 as described in the first embodiment.

FIG. 11 is a graph comparing the IV characteristics and the light output characteristics of the GaN-based compound semiconductor light emitting device of the present invention described above and the conventional one. In the figure, the dotted line indicates the present invention and the conventional IV characteristic, the solid line indicates the light output characteristic of the present invention, and the one-dot chain line indicates the conventional light output characteristic. The forward voltage with respect to a current of 20 mA is 3.8 V in the present invention and the conventional, and the conventional optical output is about 70 μW in the related art. In contrast, the present invention has a good characteristic of 100 μW. Variations in IV characteristics and optical output within the wafer surface were extremely small, and the element yield was 90% or more.

In the first and second embodiments, GaN
Although described as a layer, the present invention is not limited to this.
xGayAlzN layer: x + y + z = 1, 0 ≦ x, y, z
It may be ≦ 1. Further, Ni or AuZn is used as a material of the metal thin film electrodes 13 and 45, and I or AuZn is used as a material of the transparent electrodes 15 and 47.
Although TO (Indium Tin Oxide) was used, the invention is not limited to this. For example, the metal thin-film electrodes 13 and 45 may be made of a material containing a dopant for the p-type GaN layer 7 or the p-type GaAs contact layer 41, such as AuBe, AuMg, or AuGe. In addition, the transparent electrode 15,
In order to improve the adhesion to 47, metal thin film electrodes 13 and 4
5 may have a multilayer structure of Ni, AuZn, Ti / AuZn or the like.

Further, a sinter for using the metal thin film electrodes 13 and 45 as ohmic electrodes is provided by the metal thin film electrodes 13 and 4.
5 may be formed, or the ITO transparent electrodes 15 and
47 may be performed after the formation.

[0051]

As described above, according to the compound semiconductor light emitting device and the method of manufacturing the same of the present invention, a metal thin film electrode containing a dopant of the same conductivity type is formed on a compound semiconductor layer, and a transparent thin film formed thereon is formed. Since an electrode in contact with at least a part of the electrode is formed, a compound semiconductor light-emitting element which is low in production cost and suitable for mass productivity can be provided. Also,
An insulating film or the like is provided under the transparent electrode so that current does not flow directly under the transparent electrode, so that current can flow efficiently to the light emitting surface, so that light with sufficient emission power can be extracted.

[Brief description of the drawings]

FIG. 1 is a sectional structural view showing a manufacturing method according to a first embodiment of the present invention.

FIG. 2 is a sectional structural view following FIG. 1;

FIG. 3 is a sectional structural view of the GaN-based compound semiconductor light emitting device following FIG. 2;

FIG. 4 is a sectional view in which the light emitting device of the first embodiment is installed on a cup-type lead frame 21;

FIG. 5 is a sectional structural view showing another structure around a P-side electrode according to the first embodiment.

FIG. 6 is a perspective view showing another shape of the metal thin film electrode.

FIG. 7 is a sectional structural view showing a manufacturing method according to a second embodiment of the present invention.

FIG. 8 is a sectional structural view following FIG. 7;

FIG. 9 is a sectional structural view of the GaAs compound semiconductor light emitting device following FIG. 8;

FIG. 10 is a sectional structural view showing another structure around a P-side electrode according to the second embodiment.

FIG. 11 is a graph comparing an IV characteristic and a light output characteristic of the present invention with a conventional one.

FIG. 12 is a sectional structural view of a conventional GaN-based compound semiconductor light emitting device.

FIG. 13 is a sectional structural view of a conventional GaAs compound semiconductor light emitting device.

[Explanation of symbols]

Reference Signs List 1 sapphire substrate 3 GaN buffer layer 5 n-type GaN layer 7 p-type GaN layer 9 N-side electrode 11 SiO ₂ film 13 metal thin-film electrode 15 ITO transparent electrode 17 P-side electrode for bonding pad 19 Cup-type lead frame 21 P-side electrode terminal Reference Signs List 23 semi-insulating layer 31 n-type GaAs substrate 33 n-type GaAs buffer layer 35 n-type AlGaInP clad layer 37 AlGaInP active layer 39 p-type AlGaInP clad layer 41 p-type GaAs contact layer 43 current block layer 45 metal thin film electrode 47 ITO transparent electrode 49 P-side electrode 51 N-side electrode

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-8-125224 (JP, A) JP-A-8-250768 (JP, A) JP-A-8-250769 (JP, A) JP-A-9-205 129933 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 33/00

Claims (8)

(57) [Claims] 1. A compound semiconductor light emitting device for extracting light from a GaN-based compound semiconductor layer, comprising: a sapphire substrate; and a first conductivity type InxGay grown on the sapphire substrate.
AlzN layer (x + y + z = 1, 0 ≦ x, y, z ≦ 1)
And a second conductivity type InxG grown on the first conductivity type GaN layer.
ayAlzN layer (x + y + z = 1, 0 ≦ x, y, z ≦
1) and the second conductivity type GaN layer is insulated from the first conductivity type GaN layer.
xGayAlzN layer (x + y + z = 1, 0 ≦ x, y, z
≦ 1), a first electrode formed on the second conductive type InxGayAlzN layer (x + y + z =
An insulating film formed in a partial region above (1, 0 ≦ x, y, z ≦ 1); and the second conductivity type InxGayAlzN layer (x + y + z =
1,0 ≦ x, y, z ≦ 1), the second conductivity type InxGayAl formed in a region other than the insulating film formation region.
a metal thin-film electrode containing the same conductivity type dopant as the zN layer (x + y + z = 1, 0 ≦ x, y, z ≦ 1); a transparent electrode formed on the metal thin-film electrode; A compound semiconductor light-emitting device, comprising: a second electrode in contact with at least a part of the transparent electrode. 2. A method of manufacturing a compound semiconductor light emitting device for extracting light from a GaN-based compound semiconductor layer, comprising: a first conductivity type InxGayAlzN layer (x + y + z = 1, 0 ≦ x, y, z ≦ 1) on a sapphire substrate. Growing the first conductivity type InxGayAlzN layer (x + y + z =
Growing a second conductivity type GaN layer on (1,0 ≦ x, y, z ≦ 1); and forming the first conductivity type InxGayAlzN layer (x + y + z =
Forming a first electrode insulated from the second conductivity type GaN layer on (1,0 ≦ x, y, z ≦ 1); and forming the second conductivity type InxGayAlzN layer (x + y + z =
Forming an insulating film in a partial region on (1, 0 ≦ x, y, z ≦ 1); and forming the second conductivity type InxGayAlzN layer (x + y + z =
1,0 ≦ x, y, z ≦ 1), in a region other than the insulating film formation region, the second conductivity type InxGayAlzN layer (x
+ Y + z = 1, 0 ≦ x, y, z ≦ 1), forming a metal thin-film electrode containing the same conductivity type dopant, forming a transparent electrode on the metal thin-film electrode, Forming a second electrode that is in contact with at least a part of the transparent electrode. 3. A compound semiconductor light emitting device for extracting light from a GaN-based compound semiconductor layer, comprising: a sapphire substrate; and a first conductivity type InxGay grown on the sapphire substrate.
AlzN layer (x + y + z = 1, 0 ≦ x, y, z ≦ 1)
And the first conductivity type InxGayAlzN layer (x + y + z =
1,0 ≦ x, y, z ≦ 1) and a second conductivity type InxGayAlzN layer having a semi-insulating layer (x + y + z =
1,0 ≦ x, y, z ≦ 1) and the second conductivity type InxGayAlzN layer (x + y + z =
1,0 ≦ x, y, z ≦ 1), and the first conductivity type InxGayAlzN layer (x + y + z = 1,0 ≦ x,
y, z ≦ 1) and a second conductivity type InxGayAlzN layer (x + y + z =
The second conductivity type InxGayAlzN layer (x +) formed on a layer other than the semi-insulating layer of 1,0 ≦ x, y, z ≦ 1)
y + z = 1, 0 ≦ x, y, z ≦ 1), a metal thin film electrode containing the same conductivity type dopant, a transparent electrode formed on the metal thin film electrode, and the second conductivity type InxGayAlzN layer (x + y + z =
A compound semiconductor light emitting device comprising: a second electrode formed on a semi-insulating layer (1, 0 ≦ x, y, z ≦ 1) and in contact with at least a part of the transparent electrode. 4. A method of manufacturing a compound semiconductor light emitting device for extracting light from a GaN-based compound semiconductor layer, comprising: a first conductivity type InxGayAlzN layer (x + y + z = 1, 0 ≦ x, y, z ≦ 1) on a sapphire substrate. Growing the first conductivity type InxGayAlzN layer (x + y + z =
A second conductivity type InxGayAlzN layer having a semi-insulating layer on (1,0 ≦ x, y, z ≦ 1) (x + y + z = 1,0 ≦
(x, y, z ≦ 1); and the first conductivity type InxGayAlzN layer (x + y + z = 1).
1,0 ≦ x, y, z ≦ 1) on the second conductivity type InxG
ayAlzN layer (x + y + z = 1, 0 ≦ x, y, z ≦
1) forming a first electrode that is insulated from the second conductivity type InxGayAlzN layer (x + y + z =
On the layers other than the semi-insulating layer of (1,0 ≦ x, y, z ≦ 1), the second conductivity type InxGayAlzN layer (x + y + z =
1,0 ≦ x, y, z ≦ 1) forming a metal thin film electrode containing a dopant of the same conductivity type as above, forming a transparent electrode on the metal thin film electrode, and forming the second conductivity type InxGayAlzN layer ( x + y + z =
Forming a second electrode in contact with at least a part of the transparent electrode on a semi-insulating layer (1, 0 ≦ x, y, z ≦ 1). Method. 5. A compound semiconductor light emitting device for extracting light from a GaAs-based compound semiconductor layer, comprising: a first conductivity type GaAs substrate; and a plurality of layers of AlG laminated on the first conductivity type GaAs substrate.
an aInP layer; a second conductivity type GaAs layer formed on the uppermost layer of the AlGaInP layer; an insulating film formed in a partial region on the second conductivity type GaAs layer; A metal thin-film electrode including a dopant of the same conductivity type as that of the GaAs layer of the second conductivity type formed in a region other than the insulating film forming region; a transparent electrode formed on the metal thin-film electrode; And a second electrode formed on the back surface of the GaAs substrate of the first conductivity type, wherein the first electrode is in contact with at least a part of the transparent electrode. 6. A method for manufacturing a compound semiconductor light emitting device for extracting light from a GaAs-based compound semiconductor layer, comprising: stacking a plurality of AlGaInP layers on a GaAs substrate of a first conductivity type; GaAs of the second conductivity type
Forming a layer; forming an insulating film in a partial region on the second conductivity type GaAs layer; forming the second conductive type GaAs layer in a region other than the insulating film forming region on the second conductivity type GaAs layer. A step of forming a metal thin-film electrode containing the same conductivity type dopant as the conductive GaAs layer; a step of forming a transparent electrode on the metal thin-film electrode; and a step of contacting at least a part of the transparent electrode on the insulating film. A method for manufacturing a compound semiconductor light emitting device, comprising: forming one electrode; and forming a second electrode on the back surface of the GaAs substrate of the first conductivity type. 7. The method according to claim 1, wherein the insulating film is formed of a first conductivity type AlGaIn.
7. The compound semiconductor light-emitting device according to claim 5, wherein the film is a P film or a GaAs film of the first conductivity type. 8. The compound semiconductor light emitting device according to claim 1, wherein said metal thin film electrodes are arranged in a plurality of islands.