JPH11135827A - Light-emitting element and manufacture therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a decline of emitted light intensity when an Al mixed crystal ratio (x) is reduced. SOLUTION: A semiconductor substrate 1, for which an (n)-type Alx Ga1-x As layer 1a of (x)=0.15 is formed on a surface, is prepared (a), and a diffusion mask film (insulation film) 2 provided with an opening part 2a is formed on it (b). Then, a diffusion source film 3, containing Zn to be (p)-type impurities is formed on it, and an annealing cap film 4 is formed on it (c). Then, Zn is diffused from the diffusion source film 3 to the (n)-type layer 1a at the opening part 2a by a diffusion anneal processing, and a (p)-type Alx Ga1-x As area 5 is formed. Thereafter, the diffusion source film 3 and the annealing cap film 4 are removed, and a (p)-side electrode in contact with the (p)-type region 5 is provided. The (p)-side electrode is brought into ohmic contact with the (p)-type region 5 since (x) is small, the (p)-type region of high density is formed, since a GaAs contact layer is not provided on a substrate surface as before, and thus a current is spread and the declined in the emitted light intensity is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for a light source of a print head of an electrophotographic printer and the like.
a light emitting element having a pn junction composed of an l _x Ga _1-x As (mixed crystal of aluminum and gallium arsenide) layer and a second conductivity type Al _x Ga _1-x As region, and a first conductivity type Al _x
The second conductivity type Al _x Ga is diffused into the Ga _1-x As layer by a diffusion method.
_{The present} invention relates to a method for manufacturing a light emitting element forming a _1-x As region.

[0002]

2. Description of the Related Art As a light emitting device having a pn junction of Al _x Ga _{1 -x} As, for example, there is a light emitting device shown in FIG. 7 and a light emitting device disclosed in JP-A-3-27578. The light emitting device shown in FIG. 7 has an n-type GaAs substrate 1b, an n-type Al _x Ga _1-x As layer 1a epitaxially formed thereon, and a semi-insulating (non-doped) or n _- type epitaxially formed thereon. Type GaAs contact layer 10
1a, GaAs contact layer 101a and n-type Al
p-type GaAs contact region 105a and p-type Al _x Ga _{1-x As} 105 formed in _x Ga _1-x As layer 1a
and a semiconductor substrate 101 having a p-type semiconductor region 105 of b. Further, the insulating film 2 having the opening 2a and the p-type GaAs contact region 105a are
P-side electrode 106 connected to n _- type Al _x Ga _1-x As region 105b and n-type Al _x G through n-type GaAs substrate 1b
and an n-side electrode 7 connected to the a _1-x As layer 101a.

The light emitting device shown in FIG. 7 is an n-type GaAs substrate 1b.
An insulating film 2 serving as a diffusion mask film is formed on a semiconductor substrate 101 on which an n-type Al _x Ga _{1 -x} As layer 1a and a GaAs contact layer 101a are formed, and a p-type impurity of zinc is formed on the diffusion mask film. A diffusion source film containing (Zn) is formed, and Zn is solid-phase-diffused from the diffusion source film into the semiconductor substrate 101 in the opening 2a in the opening 2a by annealing.
By forming a p-type semiconductor region 105 in the contact layer 101a and the n-type Al _x Ga _{1 -x} As layer 1a, A
It is obtained by forming a pn junction of l _x Ga _1-x As. A plurality of p-type semiconductor layers 105 separated from each other are formed in an array on the n-type Al _x Ga _{1 -x} As layer 1a, and the p-side electrodes 6 are individually provided for each of the p-type semiconductor layers 105. Some light emitting elements are provided, and such a light emitting element is particularly called a light emitting element array.

FIG. 8 is a cross-sectional view of a light emitting element array disclosed in Japanese Patent Application Laid-Open No. Hei 3-27578, which shows an example in which a carrier barrier layer and a light absorbing layer are provided under a light emitting layer with a hetero structure. Here, two light emitting elements are illustrated for simplification of the description. 8, an n-GaAs absorption layer 114, an n-AlAs
The carrier barrier layer 116 and the n-Al _0.2 Ga _0.8 As light emitting layer 118 (in this case, the light emission wavelength is about 720 [n
m]), the p-Al _0.5 Ga _0.5 As window layer 120 and the p ⁺ -GaAs contact layer 122 are formed by MOCVD (Me
(tal-Organic Chemical Vapor Deposition) method. And the n-electrode 126 is n-GaAs
On the substrate 110, a p-electrode 124 is deposited on the p ⁺ -GaAs contact layer 122, a p-electrode 124 is formed using photolithography and chemical etching, and a mesa shape to be a light emitting region is formed. A film 128 is coated and an ohmic contact is formed between the p-electrode 124 and the n-electrode 126 by heat treatment.

[0005] As in this example, the window layer 12 has a heterostructure or the like so as to be transparent to the emission wavelength of the light emitting layer.
When an Al mixed crystal ratio of 0 is set, for example, it becomes 0.5 or the like. When the Al mixed crystal ratio increases, Al is easily oxidized. Therefore, the p ⁺ -GaAs contact layer 122 is formed on the p-Al _0.5 Ga _0.5 As window layer 120 as a protective film. Therefore, p electrode 124 is in contact with p ⁺ -GaAs contact layer 122.

[0006]

However, in the light emitting device shown in FIG. 7, when the desired emission wavelength is long and the Al mixed crystal ratio x is small, for example, the desired emission wavelength is 760.
When the Al mixed crystal ratio x is about 0.15, the diffusion of Zn is blocked by the GaAs contact layer 101a, and the diffusion in the depth direction becomes difficult to enter.
The Zn concentration on the surface of the p-type semiconductor region 105, that is, the surface of the p-type GaAs contact region 105a, cannot be increased, so that current flows only directly below the p-side electrode 6, and the light emission intensity becomes weak. There was a problem.

The present invention solves such a conventional problem. When the Al mixed crystal ratio x is reduced (x <
(When 0.3) is intended to prevent a decrease in the emission intensity.

[0008]

In order to achieve the above object, a light emitting device according to the present invention comprises a first conductivity type Al _x Ga _{1 -x.}
A semiconductor substrate having a second conductivity type Al _x Ga _{1 -x} As region joined to an As layer and the first conductivity type Al _x Ga _{1 -x} As layer; and a second conductivity type Al _x Ga _{1 -x} As. A second conductive side electrode connected to the region, wherein the second conductive side electrode is in contact with the second conductive type Al _x Ga _{1 -x} As region.

Further, the method for manufacturing a light emitting device of the present invention comprises:
The second conductivity type impurity is diffused from the surface of the semiconductor substrate having the conductivity type Al _x Ga _{1 -x} As layer into the substrate, whereby the second conductivity type impurity is diffused into the first conductivity type Al _x Ga _{1 -x} As layer. Al _x Ga in the manufacturing method of the light emitting elements forming the _1-x as region, providing a semiconductor substrate having a first conductivity type Al _x Ga _1-x as layer on the surface, the first conductivity type Al _x Forming a diffusion source film containing the impurity on the Ga _1-x As layer, and diffusing the impurity directly from the diffusion source film into the first conductivity type Al _x Ga _1-x As layer by annealing. Forming a second conductivity type Al _x Ga _{1 -x} As region.

[0010]

1A and 1B are diagrams showing a structure of a light emitting device according to an embodiment of the present invention, wherein FIG. 1A is a top view, and FIG. 1B is a cross-sectional view taken along line AA 'in FIG. It is. The light emitting device shown in FIG. 1 includes an n-type GaAs substrate 1b, an n-type Al _x Ga _{1- x} As layer 1a epitaxially formed thereon,
p-type Al _x formed on n-type Al _x Ga _1-x As layer 1a
And a semiconductor substrate 1 having a Ga _{1- x} As region 5. Further, it includes an insulating film 2, a p-side electrode 6, and an n-side electrode 7.

The n-type impurity doped in the n-type Al _x Ga _{1 -x} As layer 1a and the n-type GaAs substrate 1b is, for example, silicon (Si). n-type Al _x Ga _1-x As
Here, the Al mixed crystal ratio x of the layer 1a is set to x = 0.15. When the Al mixed crystal ratio x = 0.15, the light emission of the light emitting element shown in FIG. 1 is red light having a wavelength of about 760 [nm]. The n-type Al _x Ga _{1 -x} As layer 1a is a semiconductor substrate 1
Is formed on the surface. The insulating film 2 is formed on the semiconductor substrate 1 and has an opening 2a for exposing the surface of the p-type Al _x Ga _{1 -x} As region 5.

The p-type Al _x Ga _{1 -x} As region 5 is formed by opening the p _- type Al _x Ga _{1 -x} As layer _{1 a} from the opening 2 a of the insulating film 2.
It is selectively formed in the n-type Al _x Ga _{1 -x} As layer _{1 a} under the opening 2 a by solid-phase diffusion of the type impurity, and is formed on the surface of the semiconductor substrate 1. Here, the p-type impurity is Zn. The p-side electrode 6 is in contact with the p-type Al _x Ga _1-x As region 5 at the opening 2a. Here, the p-side electrode 6 is Al. The n-side electrode 7 is formed on the back surface of the semiconductor substrate 1,
contact the n-type GaAs substrate 1b, it is connected to the n-type Al _x Ga _1-x As layer through the n-type GaAs substrate 1b.

The light-emitting device of the present invention shown in FIG. 1 does not have a conventional p-type GaAs contact region, but has a semiconductor substrate 1 having an n-type Al _x Ga _{1 -x} As layer 1a on the surface.
Is used to form a p-type Al _x Ga _{1 -x} As region 5 by solid-phase diffusion of Zn directly into the n-type Al _x Ga _{1 -x} As layer 1 a, and to form the p-type Al _x Ga _{1 -x} As P in region 5
It is characterized in that the side electrodes 6 are brought into contact. When the Al mixed crystal ratio x is small (x <0.3), p
Even if the GaAs contact region is not provided, the p-type Al _x
Al in the Ga _1-x As region 5 is not oxidized, and the p-side electrode 6 is
It is possible to make ohmic contact with the type Al _x Ga _{1 -x} As region 5.

FIG. 2 shows a part of a manufacturing process of a light emitting device according to the present invention, in which an n-type Al _x Ga ₁ -xAs layer 1 a is formed on a p-type Al _x G
FIG. 3 is a diagram illustrating a solid-phase diffusion step of forming an a _1-x As region 5; First, as shown in FIG. 2A, on an n-type GaAs substrate 1b, an n-type Al _x Ga having an Al mixed crystal ratio x = 0.15 is formed.
A semiconductor substrate 1 on which a _1-x As layer 1a is epitaxially grown is prepared. The thickness of the n-type Al _x Ga _{1 -x} As layer 1a is, for example, about 3 [μm].

Next, as shown in FIG. 2B, the n-type Al _x
An insulating film (diffusion mask film) 2 is formed on the Ga _1-x As layer 1a, and an opening 2a is formed in the insulating film 2. As the diffusion mask film 2, aluminum oxide (Al ₂ O) is used here.
₃ ) Use a membrane. The Al ₂ O ₃ film is made of n-type Al _x Ga _1-x
Good adhesion to As layer 1a and n-type A
Since it is close to that of the l _x Ga _1-x As layer 1a, it is possible to reduce the stress applied to the n-type Al _x Ga _1-x As layer 1a during diffusion annealing. The Al ₂ O ₃ film is formed to a thickness of, for example, about 2000 [Å] by an RF sputtering method or the like. Opening 2a is formed by n-type Al _x Ga _1-x As layer 1a of p-type Al _x Ga _1-x As regions 5 and made plans known photolithography on a region of and an etching method.

Next, as shown in FIG. 2C, a diffusion source film 3 containing a p-type impurity is formed on the semiconductor substrate 1 on which the diffusion mask film 2 has been formed. The diffusion source film 3 has a thermal expansion coefficient of n
Type Al _x Ga _1-x desirably As layer 1a is a close film, a p-type impurity in this case as this film Z
A ZnO—SiO ₂ film containing n (a mixed film of zinc oxide (ΖnO) and silicon dioxide (SiO ₂ )) is used. ZnO-
The SiO ₂ film is formed by sputtering, for example, to about 350
The film is formed to a thickness of [Å]. Subsequently, an annealing cap film 4 is formed on the diffusion source film 3. Annealed cap film 4
Efficiently converts Zn from the diffusion source film 3 into n-type Al _x Ga _{1 -x} A.
It is provided to diffuse into the s layer 1a. The annealing cap film 4 has a thermal expansion coefficient of n-type Al _x Ga _{1 -x} As layer 1
It is desirable that the film be close to a, and such a film includes an Al ₂ O ₃ film or an aluminum nitride (AlN) film. Here, an AlN film is used as the annealing cap film 4. The AlN film is formed, for example, by about 1
The film is formed to a thickness of 000 [Å].

Next, as shown in FIG. 2 (d), the diffusion annealing treatment is performed to
Zn is diffused into the Al _x Ga _{1 -x} As layer
An l _x Ga _1-x As region 5 is formed. In the diffusion annealing treatment, the semiconductor substrate 1 is placed in an open tube annealing furnace made of, for example, quartz, and the semiconductor substrate 1 is heated while flowing nitrogen into the open tube annealing furnace. For example, by annealing at about 650 [° C.] for about 1 hour, the n-type Al _x Ga _{1 -x} As layer 1
Zn is diffused from the surface a. For example, in this case, 200
In the [μm] square opening, the diffusion depth Xj, that is, the depth of the p-type Al _x Ga ₁ -xAs region 5 is about 2.2 [μm]. At this time, the n-type Al _x Ga _{1 -x} As layer 1a
Al ₂ O ₃ with good adhesion to aluminum
By using the diffusion mask film 2 made of a film, the n-type Al _x Ga _{1 -x} A
Zn can be selectively diffused favorably in the s layer 1a.

The solid phase diffusion step of the present invention shown in FIG. 2, the surface of a semiconductor substrate 1 is an n-type Al _x Ga _1-x As layer 1a, on the n-type Al _x Ga _1-x As layer 1a The diffusion source film 3 is brought into close contact with Zn, and Zn is directly transferred from the diffusion source film 3 to the n-type Al _x G
By diffusing into the a _{1 -x} As layer 1 a, a high concentration p-type semiconductor region, that is, p-type Al _x is formed on the surface of the semiconductor substrate 1.
It is characterized in that a Ga _1-x As region is formed.

As described above, the n-type Al _x Ga _{1 -x} As layer 1 a
P-type Al _x Ga _{1 -x} As region 5 by solid phase diffusion of Zn
Is formed. Thereafter, the diffusion source film 3 and the annealing cap film 4 are removed by a known etching method, and the p-type Al _x Ga _{1 -x} As region 5 is formed in the opening 2a of the insulating film 2.
A p-side electrode 6 is formed on the surface of the semiconductor substrate 1 to make contact with the n-type GaAs substrate 1b.
The side electrode 7 is formed on the back surface of the semiconductor substrate 1. p-side electrode 6
For example, Al is used, and as the n-side electrode 7, for example, a gold (Au) alloy is used.

FIG. 3 shows a semiconductor substrate 1 of the light emitting device of the present invention.
It is a figure which shows the Zn concentration profile from the substrate surface (refer FIG. 1) and the semiconductor substrate 101 (refer FIG. 7) of the conventional light emitting element. As for the materials and thicknesses of the diffusion mask film, the diffusion source film, and the annealing cap film, the dimensions of the opening, the annealing temperature, and the annealing time, the conditions described in FIG. From Figure 3, the surface is an n-type Al _x Ga _1-x As layer 1a, the semiconductor substrate 1 of the light emitting device of the present invention that the n-type Al _x Ga _1-x As layer 1a directly Zn was solid-phase diffusion It can be seen that Zn is more easily diffused into the semiconductor substrate than the semiconductor substrate 101 of the conventional light emitting element provided with the GaAs contact layer 101a on the surface, the Zn concentration on the substrate surface is higher, and the Zn can be diffused deeper. GaAs as before
When diffusing Zn into the s contact layer 101a,
Although the diffusion of Zn is blocked by the GaAs contact layer, the Zn is directly diffused into the n-type Al _x Ga _1-x As layer 1a without providing the GaAs contact layer as in the present invention, so that Zn is highly concentrated. Can be diffused.

FIG. 4 is a diagram showing current-emission intensity characteristics of the light emitting device of the present invention (FIG. 1) and the conventional light emitting device (FIG. 7). FIG. 4 shows that the p-type Al _x Ga _{1 -x} As region 5
The light emitting device of the present invention in which the side electrode 6 is in contact with the p-side electrode 10 is formed on the p-type GaAs contact layer 105a.
It can be seen that the luminous intensity is higher than that of the conventional light emitting element in which No. 6 is contacted. P-type Al _x Ga of the light emitting device of the present invention
_{Since the 1-x} As region 5 has a high Zn concentration on the surface and the current spreads not only in the contact region with the p-side electrode 6 but also in the periphery thereof, the light emission intensity can be increased.

As described above, according to the embodiment of the present invention,
Using a semiconductor substrate 1 whose surface is an n-type Al _x Ga _{1 -x} As layer 1 a, Zn is directly solid-phase diffused into the n-type Al _x Ga _{1 -x} As layer 1 a, and a high concentration The p-type Al _x Ga _1-x As region 5 is formed and the p-type Al _x G
By bringing the p-side electrode 6 into contact with the a _1-x As region 5, it is possible to prevent a decrease in emission intensity even when the Al mixed crystal ratio x is small (x <0.3).

The light emitting device of the present invention is not limited to the structure shown in FIG. FIG. 5 is a sectional view showing a structure of another light emitting device according to the embodiment of the present invention. FIG. 5 (a)
In FIG. 1, the n-type GaAs substrate 1 is provided with an n-type electrode 7 on the front surface of the semiconductor substrate 1 instead of the rear surface.
The contact is made not to b but to the n-type Al _x Ga _{1 -x} As layer 1a.

FIG. 5B shows an n-type A in FIG.
The l _x Ga _1-x As layer 1a has a plurality of p
Type Al _x Ga _{1 -x} As regions 5 are formed in an array, that is, in a row at a predetermined pitch, and each p-type Al _x Ga
_This is a light emitting element array in which p-side electrodes 6 are individually provided in _1-x As regions 5. In the solid phase diffusion step of the light emitting element array, a plurality of openings 2a are formed in the diffusion mask film 2 in an array. If the solid phase diffusion process described in FIG. 2 is used, Zn can be selectively diffused favorably, so that a high-density light emitting element array corresponding to an electrophotographic printer having a dot density of 1200 [dpi] can be manufactured, for example. 12
In the light emitting element array corresponding to 00 [dpi], the p-type Al _x Ga _{1 -x} As region 5 serving as a light emitting portion is about 21 μm.
m] intervals. The n-side electrode 7 may be provided on the surface of the semiconductor substrate 1 as shown in FIG.

Further, the semiconductor substrate used for the light emitting device of the present invention is not limited to the structure shown in FIG. FIG.
FIG. 3 is a cross-sectional view showing a structure of another semiconductor substrate used in the embodiment of the present invention. Semiconductor substrate 2 shown in FIG.
1 is not n-type but semi-insulating (non-doped) GaAs
The n-type Al _x Ga _1-x As layer 1a is obtained by epitaxial growth on the substrate 21b. The semiconductor substrate 21 of FIG. 6A can be used for the light emitting element array of FIG. 5B in which the light emitting element and the n-side electrode 7 of FIG. 5A are provided on the surface of the semiconductor substrate. The semiconductor substrate 1 shown in FIG. 1 and the semiconductor substrate 21 shown in FIG. 6A are formed by forming another semiconductor epitaxial layer (for example, n) on the GaAs substrate 1b or 21b.
N-type Al _x Ga _{1 -x} As layer 1a via a p-type GaAs epitaxial layer and a non-doped GaAs epitaxial layer)
May be formed.

The semiconductor substrate 22 shown in FIG.
A semi-insulating semiconductor layer 22b made of, for example, a GaAs layer is epitaxially grown on an n-type or high-resistance (non-doped) silicon (Si) substrate 22c, and an n-type Al _x Ga _{1-x is} formed on the semi-insulating semiconductor layer 22b. This is obtained by epitaxially growing the As layer 1a. The semiconductor substrate 22 shown in FIG. 6B can be used for a light emitting element and a light emitting element array having a structure in which the n-side electrode 7 is provided on the surface of a semiconductor substrate. The semiconductor substrate having the Si substrate 22c instead of the GaAs substrate can be obtained at a low price, the wafer can be made large in diameter, and the flatness of the wafer is high and it is hard to be broken. There are advantages such as that the production cost can be reduced, the processing accuracy of the light emitting element can be increased, a light emitting element array having a long size can be manufactured, and the like.

[0027]

As described above, according to the present invention, a semiconductor substrate having a surface of a first conductivity type Al _x Ga _{1 -x} As layer is used, and the first conductivity type Al _x Ga _{1 -x} As layer is used. the second conductivity type impurity directly cause solid phase diffusing the high concentration second conductivity-type Al _x Ga _{1- x} As region is formed on the surface of the semiconductor substrate, the second conductivity type Al _x Ga _1-x As region In addition, direct contact of the second conductive side electrode with the second conductive side electrode has an effect that a decrease in emission intensity can be prevented even when the Al mixed crystal ratio x is small (x <0.3).

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a structure of a light emitting element according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a manufacturing process of the light emitting device according to the embodiment of the present invention.

FIG. 3 is a diagram showing Zn concentration profiles from the surface of a semiconductor substrate in a light emitting device of the present invention and a conventional light emitting device.

FIG. 4 is a diagram showing current-emission intensity characteristics of a light-emitting element of the present invention and a conventional light-emitting element.

FIG. 5 is a diagram illustrating a structure of another light emitting element according to an embodiment of the present invention.

FIG. 6 is a sectional view showing the structure of another semiconductor substrate used in the embodiment of the present invention.

FIG. 7 is a cross-sectional view illustrating a structure of a conventional light emitting device.

FIG. 8 is a cross-sectional view illustrating a structure of a conventional light emitting device using a hetero structure.

[Explanation of symbols]

1,21,22 semiconductor substrate, 1a, n-type Al _x G
a _1-x As layer, 1bn-type GaAs substrate, 2 insulating film (diffusion mask film), 2a opening, 3 diffusion source film,
4 Annealed cap film, 5 p-type Al _x Ga _1-x A
s region, 6 p-side electrode, 7 n-side electrode, 21 b semi-insulating GaAs substrate, 22 b semi-insulating semiconductor layer, 2
2c Si substrate.

Continuing from the front page (72) Inventor Takaatsu Shimizu 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd.

Claims (18)

[Claims] A first conductive type Al _x Ga _{1 -x} As layer and a second conductive type Al _x Ga _{1 -x} As layer.
A semiconductor substrate having a conductive type Al _x Ga _{1 -x} As region; and a second substrate connected to the second conductive type Al _x Ga _{1 -x} As region.
A conductive side electrode, wherein the second conductive side electrode is the second conductive type Al _x Ga _1-x
A light-emitting element which is in contact with an As region. 2. The value of the Al mixed crystal ratio x is 0 <x <0.
3. The light emitting device according to claim 1, wherein Wherein said second conductivity type Al _x Ga _1-x As region, the first by diffusing the second conductivity type impurity
Emitting device according to claim 1, characterized in that formed on the conductive type Al _x Ga _1-x As layer. 4. The light emitting device according to claim 3, wherein said Al _x Ga _{1 -x} As layer is n-type, and said impurity is Zn. 5. The semiconductor device according to claim 1, wherein said first conductivity type is Al _x Ga _{1 -x.}
An insulating film having an opening is provided on the As layer, and the second conductivity type Al _x Ga _1-x As region is selectively formed in the first conductivity type Al _x Ga _1-x As layer below the opening. The light emitting device according to claim 3, wherein the light emitting device is formed. 6. A plurality of the second conductivity type Al _x Ga _{1 -x} As regions are formed in the first conductivity type Al _x Ga _{1 -x} As layer in an array form separated from each other. The two conductive side electrodes are each of the second conductive type Al _x G
4. The light emitting device according to claim 3, wherein the light emitting device is provided individually in the a _1-x As region. 7. The semiconductor device according to claim 1, wherein the semiconductor substrate is a first conductive type or semi-insulating GaAs substrate, and the first conductive type Al
light emitting device according to claim 3, wherein a is obtained by forming an epitaxial layer containing an _x Ga _1-x As layer. 8. The semiconductor device according to claim 1, wherein the semiconductor substrate is a first conductivity type or high resistance Si substrate, and the first conductivity type Al _x Ga _{1 -x} A
The light emitting device according to claim 3, wherein an epitaxial layer including an s layer is formed. 9. The first conductivity type Al _x Ga _{1 -x} A by diffusing a second conductivity type impurity into the substrate from the surface of the semiconductor substrate having the first conductivity type Al _x Ga _{1 -x} As layer.
In a method for manufacturing a light emitting device in which a second conductivity type Al _x Ga _{1 -x} As region is formed in an s layer, a step of preparing a semiconductor substrate having the first conductivity type Al _x Ga _{1 -x} As layer on a surface; Forming a diffusion source film containing the impurity on the first conductivity type Al _x Ga ₁ -xAs layer; and annealing the impurity directly from the first conductivity type Al _x Ga by annealing treatment. Diffusion into _1-x As layer, second
Forming a conductive type Al _x Ga _{1 -x} As region. 10. The value of the Al mixed crystal ratio x is 0 <x <
The method for manufacturing a light emitting device according to claim 9, wherein the value is 0.3. 11. The method according to claim 1, wherein the diffusion source film is formed of Z which is the impurity.
The method for manufacturing a light emitting device according to claim 9, wherein the method is a ZnO—SiO ₂ film containing n. 12. Before the step of forming a diffusion source film,
Forming a diffusion mask film having an opening on the first conductivity type Al _x Ga _{1 -x} As layer, wherein the step of forming a diffusion source film comprises the step of forming the diffusion mask film; Forming the diffusion source film on a semiconductor substrate; and performing the annealing process by removing the impurity from the diffusion source film in the opening at the first conductivity type Al _x Ga _{1 -x} A in the opening.
s layer and selectively diffused into the second conductivity type Al _x Ga
10. The method for manufacturing a light emitting device according to claim 9, wherein a _1-x As region is formed. 13. The method according to claim 13, wherein the diffusion mask film has a plurality of openings arranged in an array, and wherein the annealing is performed using the first conductivity type Al _x Ga.
_{In the 1-x} As layer, a plurality of second conductivity type Al separated from each other are provided.
method of fabricating a light emitting device according to claim 12, characterized in that to form the _x Ga _1-x As region. 14. The method according to claim 12, wherein the diffusion mask film is an Al ₂ O ₃ film. 15. The method according to claim 9, further comprising a step of forming an annealing cap film on the diffusion source film before the annealing step. 16. The method according to claim 16, further comprising: after the annealing, removing the diffusion source film; and forming the second conductivity type Al _x Ga _{1 -x} As region on the semiconductor substrate from which the diffusion source film has been removed. 10. A method for manufacturing a light emitting device according to claim 9, further comprising the step of forming a second conductive side electrode to be contacted. 17. The method according to claim 17, wherein the semiconductor substrate is a first conductivity type or semi-insulating GaAs substrate, and the surface is the first conductivity type A.
method of manufacturing a light emitting device according to claim 9, wherein a is obtained by forming an epitaxial layer is a l _x Ga _1-x As layer. 18. The semiconductor device according to claim 1, wherein the semiconductor substrate is a first conductivity type or high resistance Si substrate, and the surface is the first conductivity type Al _x G.
The method for manufacturing a light emitting device according to claim 9, wherein an epitaxial layer which is an a1 _- xAs layer is formed.