JP3219969B2 - Light emitting diode manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting diode and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, when manufacturing a light emitting diode, impurities are generally diffused into a semiconductor substrate to form a PN junction. At that time, Al ₂ O ₃ film, SiO ₂ film, SiN
A film such as a film is mainly used as a diffusion mask. An example of a method of forming a PN junction by diffusing impurities into a semiconductor substrate is disclosed in Japanese Patent Application Laid-Open No. 62-139320. According to the impurity diffusion method disclosed in this document, a diffusion mask having a diffusion window and a diffusion source film are sequentially formed on a GaAs substrate. afterwards,
Zn supplied from the diffusion source film is selectively diffused into the substrate through the diffusion window. An impurity diffusion region is formed in the substrate by the diffusion of Zn. In this case, as a diffusion mask,
A mixed film of Al ₂ O ₃ and SiO ₂ is used.

In general, the diffusion source film is etched away using a hydrofluoric acid (HF) etchant after the diffusion is completed, and the diffusion mask is left on the substrate as an interlayer insulating film. However, these diffusion masks do not have corrosion resistance to HF-based etchants. Therefore, after removing the diffusion source film, a new interlayer insulating film may be formed on the diffusion mask.

Thereafter, an aluminum electrode or an aluminum alloy electrode is formed in a region from the interlayer insulating film to the upper surface of the impurity diffusion region.

[0005]

However, when an aluminum electrode or an aluminum alloy electrode is formed in a predetermined region, the aluminum film or the aluminum alloy film is patterned using hot phosphoric acid or the like. Therefore, when the interlayer insulating film does not have corrosion resistance to hot phosphoric acid, the interlayer insulating film is etched and damaged, and there is a problem that the electric characteristics of the light emitting diode deteriorate. Further, even when the interlayer insulating film has corrosion resistance to hot phosphoric acid, a similar problem occurs when the interlayer insulating film has already been damaged.

Therefore, there has been a demand for a light emitting diode having good electrical characteristics and a method for manufacturing the same, which has solved the above problems.

Further, it is desirable that a diffusion mask provided below the interlayer insulating film has corrosion resistance to an HF-based etchant.

[0008]

[0009]

According to a first method of manufacturing a light emitting diode of the present invention, an impurity is selected in a compound semiconductor from a diffusion source film through a compound semiconductor substrate of a first conductivity type and a diffusion mask. A diffusion region of the second conductivity type formed by selective diffusion, an interlayer insulating film provided above the compound semiconductor substrate, and an electrode formed from the surface of the diffusion region to the surface of the interlayer insulating film. In the method for manufacturing a light emitting diode, a diffusion mask having a diffusion window for exposing an impurity diffusion scheduled region is formed on a compound semiconductor substrate by a film having corrosion resistance to a first etchant capable of etching a diffusion source film. Forming a diffusion source film and an annealing cap film sequentially on the diffusion mask, and then diffusing impurities from the diffusion source film into the compound semiconductor substrate by heat treatment. Forming a diffusion region by removing the anneal cap film, and then removing the diffusion source film using a first etchant; and then, on the diffusion mask and on the diffusion region exposed from the diffusion window. Forming an interlayer insulating film with a film having corrosion resistance to a diffusion mask and a second etchant capable of etching an electrode, and then diffusing from the upper surface of the diffusion mask through the side surface of the diffusion mask on the side of the diffusion window. A step of etching and removing the interlayer insulating film so as to leave at least an interlayer insulating film portion of the region where the electrode is to be provided to reach the upper surface of the region, and thereafter, an electrode mounting plan on the remaining interlayer insulating film portion and on the diffusion region After forming the electrode film in the region, the electrode film is removed using a second etchant so that the electrode film in the region where the electrode is to be provided remains. By, characterized in that it comprises a step of forming an electrode. .

In this first manufacturing method, the diffusion mask is A
1N film, and the diffusion source film is a ZnO film or ZnO / Si
An O ₂ mixed film, an interlayer insulating film is a SiN film, SiO ₂
Film, PSG film, BSG film, ZnO film and ZnO / Si
It is preferable that the film be a film containing one or more types of O ₂ mixed films, and that the electrode be an aluminum film or an aluminum alloy film.

According to the second method of manufacturing a light-emitting diode of the present invention, a step of forming a diffusion mask having a diffusion window exposing a region where impurities are to be diffused is formed on a compound semiconductor substrate of the first conductivity type. , And then to the planned area
After sequentially forming a diffusion source film made of a ZnO film or a ZnO / SiO ₂ mixed film, and an annealing cap film, Zn is diffused from the diffusion source film into the compound semiconductor substrate by heat treatment to form a diffusion region of the second conductivity type. Forming an annealing cap film and a diffusion source so that at least a diffusion source film portion of a region where an electrode is to be provided from the upper surface of the diffusion mask to the upper surface of the diffusion region through the side surface of the diffusion mask on the diffusion window side is left. A step of removing the film by etching, and thereafter, a step of forming an aluminum film or an aluminum alloy film on the remaining diffusion source film portion, the remaining annealing cap film portion and the diffusion region, and then, , Aluminum film or aluminum alloy film so that the aluminum film or aluminum alloy film remains Removed by etching, characterized in that it comprises a step of forming an aluminum electrode or aluminum alloy electrode.

According to the third method of manufacturing a light emitting diode of the present invention, a diffusion source film containing an impurity of the second conductivity type is formed in the impurity diffusion region on the compound semiconductor substrate of the first conductivity type. And then forming an annealing cap film so as to cover the diffusion source film, and then diffusing impurities from the diffusion source film into the compound semiconductor substrate by heat treatment to form a second
A step of forming a conductive type diffusion region, and thereafter, a SiN film, a SiO ₂ film, and a PS covering the diffusion source film on the upper side of the diffusion source film.
Forming an interlayer insulating film composed of at least one film selected from a G film, a BSG film, a ZnO film, and a ZnO / SiO ₂ mixed film, and thereafter, from the upper surface of the interlayer insulating film to the interlayer insulating film; Each layer from the diffusion source film provided above the diffusion region to the interlayer insulating film is removed by etching so that at least a region where an electrode is to be provided, which reaches the upper surface of the diffusion region via the side surface of each layer up to the diffusion source film, remains. Process and
Thereafter, a step of forming an aluminum film or an aluminum alloy film in a region from the remaining interlayer insulating film portion to the diffusion region, and thereafter, the aluminum film portion or the aluminum alloy film portion of the electrode disposition region is left. Forming an aluminum electrode or an aluminum alloy electrode by etching away the aluminum film or the aluminum alloy film.

[0013]

According to the light emitting diode manufacturing method of the present invention described above, the second conductivity type impurity supplied from the diffusion source film is selectively diffused into the first conductivity type compound semiconductor substrate to form the second conductivity type impurity. A mold diffusion region is formed. In this case, in the first and second methods, the impurity supplied from the diffusion source film is selectively diffused into the substrate through the diffusion window provided in the diffusion mask. In the third method, the impurity supplied from the diffusion source film is selectively diffused into the substrate, but without using a diffusion mask.

In the first method, after the diffusion region is formed, an interlayer insulating film is formed on the diffusion mask and on the diffusion region exposed from the diffusion window, and the interlayer insulating film is formed so that at least the region where the electrode is to be provided remains. The insulating film is removed by etching. Then, an electrode, desirably, an aluminum electrode or an aluminum alloy electrode is provided in a region where the electrode is to be provided.
In this case, the interlayer insulating film is a SiN film, a SiO ₂ film, a PSG film.
It is desirable that the film be made of at least one film selected from a film, a BSG film, a ZnO film and a ZnO / SiO ₂ mixed film.

In the second method, after forming the diffusion region, the annealing cap film and the diffusion source film are removed by etching so that at least the diffusion source film portion in the region where the electrode is to be provided remains. Then, an aluminum electrode or an aluminum alloy electrode is provided in a region where the electrode is to be provided.

In the third method, after forming the diffusion region, an interlayer insulating film covering the diffusion source film is formed above the diffusion source film, and the diffusion region is formed such that at least the region where the electrode is to be provided is left. Each layer from the diffusion source film provided on the upper side to the interlayer insulating film is removed by etching. Then, an aluminum electrode or an aluminum alloy electrode is provided in a region where the electrode is to be provided. In this case, the interlayer insulating film is a SiN film, SiO
₂ film, PSG film, BSG film, ZnO film and ZnO / S
It is made of at least one film selected from iO ₂ mixed films.

In the first to third methods of manufacturing a light emitting diode, when an aluminum electrode or an aluminum alloy electrode is provided in a region where an electrode is to be provided, the aluminum film or the aluminum alloy film is etched. When etching aluminum film or aluminum alloy film,
Use hot phosphoric acid.

In the first method for manufacturing a light emitting diode, an aluminum electrode or an aluminum alloy electrode is provided on an interlayer insulating film having corrosion resistance to hot phosphoric acid. Therefore, no damage occurs to the interlayer insulating film when the aluminum film or the aluminum film is etched.

Also in the second method, an aluminum electrode or an aluminum alloy electrode is provided on the diffusion source film having corrosion resistance to hot phosphoric acid. Therefore, when etching the aluminum film or the aluminum alloy film, the diffusion source film functioning as an interlayer insulating film is not damaged.

Also in the third method, an aluminum electrode or an aluminum alloy electrode is provided on each layer from the diffusion source film provided above the diffusion region to the interlayer insulating film, which has corrosion resistance to hot phosphoric acid. Therefore, when etching the aluminum film or aluminum alloy film,
Each layer from the diffusion source film functioning as an interlayer insulating film to the interlayer insulating film is not damaged.

Further, in the light emitting diode manufactured by the first to third manufacturing methods, no damage occurs to the interlayer insulating film when the aluminum electrode or the aluminum alloy electrode is formed. Therefore, the electric characteristics of the light emitting diode are good.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. In these drawings, each component merely schematically shows the shape, size, and positional relationship of each component to the extent that the present invention can be understood. Also,
In the drawings used for the description, the same constituent components are denoted by the same reference numerals. Further, numerical conditions such as a material to be used, a forming method and a film thickness described in the following description are merely preferred examples of the present invention. Therefore, it should be understood that the invention is not limited to only these conditions.

1. First Embodiment FIGS. 1A to 1C, FIGS. 2A to 2C, and FIG.
FIG. 4 is a process diagram showing a state of a structure that can be obtained in a main process in a manufacturing process of the light emitting diode of the embodiment by a cross-sectional view (a cutaway view). In these figures, a manufacturing process for one element of the light emitting diode constituting the light emitting diode array is shown. In the following description, a light emitting diode and a method for manufacturing the same will be described together.

In the case of manufacturing a light emitting diode, first, a diffusion mask 13 having a diffusion window 13a for exposing a region where impurities are to be diffused is formed on a compound semiconductor substrate 11 of a first conductivity type (here, n-type) (FIG. 1). FIG. 1 (A)).

First, in the first embodiment, for example, n
GaAs _1-x P _x (0 ≦ x ≦ 0.4) epitaxial substrate (n-type compound semiconductor substrate 11)
A 2000 nm thick AlN film is formed.

Thereafter, the AlN film is patterned using a known lithography technique to form a diffusion mask 13 having a diffusion window 13a. When patterning the AlN film, a resist film patterned into a predetermined shape is used as a mask, and hot phosphoric acid is used for etching.

Next, a second conductivity type (here, p-type) impurity is diffused into the compound semiconductor substrate 11 to form a second conductivity type diffusion region 15 (FIG. 1B).

First, in the first embodiment, the upper surface of the diffusion mask 13, the side surface of the diffusion mask 13 exposed to the diffusion window 13a, and the surface of the substrate 11 exposed from the opening 13a (namely, the diffusion expected region) are covered. As described above, the diffusion source film 1
7. An annealing cap film 19 is sequentially formed. As the diffusion source film 17, for example, Z having a thickness of 200 to 2000 Å
A mixed film of nO and SiO ₂ (hereinafter referred to as ZnO / SiO ₂
It may be called a mixed film. ) Is used. Here, Z
n is an impurity that determines the second conductivity type. The ZnO / SiO ₂ mixed film is formed by sputtering a target made of a mixture of ZnO and SiO ₂ . Further, as the annealing cap film 19, for example, 2
An AlN film having a thickness of 00 to 2000 ° is used. And
This AlN film is formed by sputtering. Note that a ZnO film or the like may be used as the diffusion source film 17.

Thereafter, in the first embodiment, for example, a heat treatment is performed in a nitrogen atmosphere at 700 ° C. for one hour,
Zn is diffused into the n-type compound semiconductor substrate 11, the diffusion depth is about 1.0 μm, and the Zn concentration is 5 × 10 ¹⁹ to
A p-type diffusion region 13 of about 1 × 10 ²⁰ cm ⁻³ is formed. In this case, a desired diffusion depth can be set depending on the temperature and time for the heat treatment.

Next, on the diffusion mask 13 and the diffusion window 13
An interlayer insulating film 21 is formed on the diffusion region 15 exposed from a (FIG. 1C and FIG. 2A).

First, in the first embodiment, the annealing cap film 19 and the diffusion source film 17 are entirely removed (FIG. 1).
(C)). For removing the annealing cap film 19 made of an AlN film and the diffusion source film 17 made of a ZnO / SiO ₂ mixed film, buffered hydrofluoric acid which is a hot phosphoric acid or hydrofluoric acid (HF) -based etchant is used. The AlN film serving as the diffusion mask 13 used in the first embodiment has corrosion resistance to an HF-based etchant. Therefore, no damage occurs to the diffusion mask 13 when removing the diffusion source film 17.

Thereafter, the upper surface of the diffusion mask 13 and the diffusion window 1
Side of diffusion mask 13 exposed to 3a and diffusion window 13
Surface of substrate 11 exposed from a (ie, diffusion region)
Is formed so as to cover (FIG. 2A).
As the interlayer insulating film 21, for example, S
An iN film is used. And this SiN film is plasma CV
Formed by Method D. The SiN film has corrosion resistance to hot phosphoric acid used for patterning an aluminum film or an aluminum alloy film in a later step. As the interlayer insulating film 21, a SiO ₂ film, a PSG film (phosphorus (P))
Containing SiO ₂ film), BSG film (SiO containing boron (B))
₂ ), a film having corrosion resistance to hot phosphoric acid, such as a ZnO film or a ZnO / SiO ₂ mixed film.

Next, the diffusion window 1 is placed on the upper surface of the diffusion mask 13.
The interlayer insulating film 21 is removed by etching so that at least the portion of the interlayer insulating film in the region where the electrode is to be provided, which reaches the upper surface of the diffusion region 15 through the side surface of the diffusion mask 13 on the 3a side, remains (FIG. 2B).

In the first embodiment, the interlayer insulating film 21 made of a SiN film is etched by using a known lithography technique. At this time, a resist film patterned into a predetermined shape is used as a mask, and CF ₄ gas and O ₂
Dry etching is performed using a mixed gas with a gas. More specifically, the interlayer insulating film 21 is formed so as to leave the entire surface of the diffusion mask, that is, the upper surface of the diffusion mask 13 and the portion of the interlayer insulating film formed on the side surface of the diffusion mask 13 exposed to the diffusion window 13a. Is removed by etching. The diffusion region 15 is exposed from the opening 21b of the etched interlayer insulating film 21a. In this case, the diffusion mask 13 is covered with the etched interlayer insulating film 21a even after the etching of the interlayer insulating film 21. Therefore, the diffusion mask 13 is completely protected from hot phosphoric acid used when patterning the aluminum film or the aluminum alloy film.

Next, a p-side electrode film 23 is formed on the etched interlayer insulating film 21a and on the diffusion region 15 exposed from the opening 21b (FIG. 2C).

In the first embodiment, the upper surface of the etched interlayer insulating film 21a, the etched interlayer insulating film 21a exposed in the opening 21b, and the surface of the substrate 11 exposed from the opening 21b (that is, the diffusion region) are covered. Like p
The side electrode film 23 is formed (FIG. 2C). p-side electrode film 2
As 3, for example, an aluminum film having a thickness of 1 μm is used. This aluminum film is formed by an electron beam evaporation method. Note that an aluminum alloy film may be used as the p-side electrode film 23.

Next, the p-side electrode film 23 is removed by etching so as to leave the p-side electrode film portion in the region where the electrodes are to be provided, thereby forming an aluminum electrode or an aluminum alloy electrode serving as the p-side electrode 23a. (FIG. 3).

In the first embodiment, the p-side electrode film 2 made of an aluminum film is formed by using a well-known lithography technique.
3 is etched to form an aluminum electrode which is the p-side electrode 23a. At this time, a resist film patterned into a predetermined shape is used as a mask, and hot phosphoric acid is used for etching. More specifically, an aluminum film portion extending from the upper surface of the etched interlayer insulating film 21a to the surface (that is, the diffusion region) of the substrate 11 exposed from the opening 21b via the etched interlayer insulating film 21a exposed to the opening 21b. The aluminum film is removed by etching so as to remain. In this case, the SiN film used as the interlayer insulating film 21 has corrosion resistance to hot phosphoric acid. Therefore, when etching the aluminum film, no damage occurs to the etched interlayer insulating film 21a.

Thereafter, after polishing the back surface of the substrate 11, a gold (Au) alloy electrode as the n-side electrode 25 is formed (FIG. 3).
Thus, a light emitting diode array was manufactured.

As described above, when an aluminum electrode or an aluminum alloy electrode is provided in a region where an electrode is to be provided, the aluminum film or the aluminum alloy film is etched. When etching an aluminum film or an aluminum alloy film, hot phosphoric acid is used. In this case, an aluminum electrode or an aluminum alloy electrode is provided on an interlayer insulating film having corrosion resistance to hot phosphoric acid. Therefore, when the aluminum film or the aluminum alloy film is etched, the interlayer insulating film is not damaged, and the short circuit between the aluminum electrode or the aluminum alloy electrode and the substrate portion other than the diffusion region can be prevented.

In the light emitting diode manufactured by such a manufacturing method, no damage occurs to the interlayer insulating film when forming the aluminum electrode or the aluminum alloy electrode. Therefore, the electric characteristics of the light emitting diode are good. In addition, since the film other than the wiring is not damaged, the appearance is improved.

2. Second Embodiment FIGS. 4A and 4B are process diagrams showing a state of a structure that can be obtained in a main process in a manufacturing process of a light emitting diode according to a second embodiment by a cross-sectional view (a cutaway view). It is.
In these figures, a manufacturing process for one element of the light emitting diode constituting the light emitting diode array is shown. In the following description, a light emitting diode and a method for manufacturing the same will be described together.

When manufacturing a light emitting diode, first, as in the case of the first embodiment, AlN having a diffusion window 13a is used.
A diffusion mask 13 made of a film, a diffusion source film 17 made of a ZnO / SiO ₂ mixed film, and an annealing cap film 19 made of an AlN film are formed. Then, by performing heat treatment, Zn as an impurity is diffused from the diffusion source film 17 to the GaAs, which is the first conductivity type (here, n type) compound semiconductor substrate 11.
s _1-x P _x (0 ≦ x ≦ 0.4) Diffusion region 15 of the second conductivity type (here, p-type) diffused into the epitaxial substrate.
(See FIGS. 1A and 1B). The diffusion mask 13 is covered with the etched diffusion source film 17a even after the etching of the annealing cap film 19 and the diffusion source film 17 in a later step. For this reason, an Al ₂ O ₃ film having no corrosion resistance to the HF-based etchant may be used as the diffusion mask. Further, a ZnO film can be used as the diffusion source film 17.

Next, from the upper surface of the diffusion mask 13, the diffusion window 1
The annealing cap film 19 and the diffusion source film 17 are removed by etching so that at least the diffusion source film portion in the region where the electrode is to be provided, which reaches the upper surface of the diffusion region 15 via the side surface of the diffusion mask 13 on the 3a side, is left (FIG. A)).

In the second embodiment, an annealing cap film 19 made of an AlN film and a diffusion source film 1 made of a ZnO / SiO ₂ mixed film are formed by using a known lithography technique.
7 is etched. At this time, a resist film patterned into a predetermined shape is used as a mask. And
Hot phosphoric acid is used for etching the annealing cap film 19, and buffered hydrofluoric acid is used for etching the diffusion source film 17. More specifically, the diffusion mask 1
Then, the annealing cap film 19 and the diffusion source film 17 are etched so that the diffusion source film portion formed on the entire surface of the diffusion mask 13 and on the side surface of the diffusion mask 13 exposed to the diffusion window is left. Remove. The diffusion region 15 is exposed from the opening 27 formed by the etched diffusion source film 17a and the etched cap film 19a. In this case, the etched cap film 1
9a remains on the upper surface of the etched diffusion source film 17a. Thus, the diffusion mask 13 is covered with the etched diffusion source film 17a even after the etching of the annealing cap film 19 and the diffusion source film 17. In this case, the ZnO / SiO ₂ mixed film as the diffusion source film 17 has corrosion resistance to hot phosphoric acid used when patterning the aluminum film or the aluminum alloy film. Therefore, the diffusion mask 13 is completely protected from hot phosphoric acid.

Next, as in the first embodiment, the p-side electrode film 23 is formed on the etched diffusion source film 17a, the etched cap film 19a, and the diffusion region 15 exposed from the opening 27. . In the second embodiment, the upper surface of the etched cap film 19a, the side surface of the etched diffusion source film 17a exposed in the opening 27, and the surface of the substrate 11 exposed from the opening 27 (that is, the diffusion region) are covered. The p-side electrode film 23 is formed. In the second embodiment, the etched diffusion source film 17a and the etched cap film 19a function as an interlayer insulating film.

Next, as in the first embodiment, the p-side electrode film 23 is etched to form the p-side electrode 23a, and then the n-side electrode 25 is formed.
(B)). Thus, a light emitting diode array was manufactured.

When a light emitting diode is manufactured as described above, the same effects as in the case of the first embodiment can be obtained.

3. Third Embodiment FIGS. 5 (A) to 5 (C) and FIGS. 6 (A) to 6 (C) are cross-sectional views showing the state of a structure that can be taken in the main steps of the manufacturing process of the light emitting diode of the third embodiment. However, FIG. In these figures, a manufacturing process for one element of the light emitting diode constituting the light emitting diode array is shown. In the following description, a light emitting diode and a method for manufacturing the same will be described together.

In manufacturing a light emitting diode, first, a second conductivity type (here, p-type) is formed in a region where impurity is to be diffused on a compound semiconductor substrate 11 of the first conductivity type (here, n-type).
5 is formed (FIG. 5).
(A)).

First, in the third embodiment, for example, n
GaAs _1-x P _x (0 ≦ x ≦ 0.4) epitaxial substrate (n-type compound semiconductor substrate 11)
A ZnO / SiO ₂ mixed film having a thickness of 200 to 2000 ° is formed.

Then, using a known lithography technique, the ZnO / SiO ₂ mixed film is patterned to leave a portion of the ZnO / SiO ₂ mixed film in a diffusion expected region to form a diffusion source film 17. When patterning a ZnO / SiO ₂ mixed film, a resist film patterned into a predetermined shape is used as a mask, and buffered hydrofluoric acid is used for etching. Note that a ZnO film or the like may be used as the diffusion source film 17.

Next, after forming an annealing cap film 19 so as to cover the diffusion source film 17, impurities are diffused from the diffusion source film into the compound semiconductor substrate 11 by heat treatment to form a second conductivity type (here, p-type). (FIG. 5)
(B)).

First, in the third embodiment, the diffusion source film 1
An annealing cap film 19 is formed so as to cover the upper surface of the substrate 7, the side surface of the diffusion source film 17, and the surface of the substrate 11 (that is, the region where no diffusion source film exists). As the annealing cap film 19, for example, Al having a thickness of 200~2000Å
An N film is used. The Al ₂ O ₃ film may be used from the viewpoint that the thermal expansion coefficient is similar to that of the substrate 11. In the case of the AlN film and Al ₂ O ₃ , the diffusion (out-diffusion) of Ga into the annealing cap film 19, which is considered to be a cause of abnormal diffusion of Zn in the lateral direction, can be suppressed.

Thereafter, as in the first embodiment, Zn is diffused into the n-type compound semiconductor substrate 11 by heat treatment to form a p-type diffusion region 13.

Next, the diffusion source film 1 is placed on the upper side of the diffusion source film 17.
7 is formed (FIG. 5C).

First, in the third embodiment, the entire surface of the annealing cap film 19 is removed. Hot phosphoric acid is used to remove the annealing cap film 19 made of the AlN film. The annealing cap film 19 does not necessarily need to be removed.

Thereafter, the upper surface of the diffusion source film 17 and the diffusion source film 1
An interlayer insulating film 21 is formed so as to cover the side surface 7 and the surface of the substrate 11 (that is, a region where no diffusion source film exists). As the interlayer insulating film 21, an SiN film having a thickness of, for example, 1000 ° is used as in the first embodiment. This SiN film is formed by a plasma CVD method. SiN
The film has corrosion resistance to hot phosphoric acid used for patterning an aluminum film or an aluminum alloy film in a later step. The interlayer insulating film 21 is made of SiO ₂
Film, PSG film, BSG film, ZnO film, ZnO / SiO ₂
A film having corrosion resistance to hot phosphoric acid such as a mixed film may be used.

Next, the diffusion region 15 is formed such that at least a region where an electrode is to be provided from the upper surface of the interlayer insulation film to the upper surface of the diffusion region 15 through the side surface of each layer from the interlayer insulation film to the diffusion source film remains. Each layer from the diffusion source film 17 provided on the upper side to the interlayer insulating film 21 is removed by etching (FIG. 6).
(A)).

In the third embodiment, the interlayer insulating film 21 made of a SiN film and the diffusion source film 17 made of a ZnO / SiO ₂ mixed film are etched by using a known lithography technique. At this time, a resist film patterned into a predetermined shape is used as a mask. The interlayer insulating film 21 is dry-etched using a mixture of CF ₄ gas and O ₂ gas, and the diffusion source film 17 is etched using buffered hydrofluoric acid. More specifically, the interlayer insulating film 21 and the diffusion source film 17 are etched such that the diffusion region 15 is exposed from the opening 29 formed by the etched diffusion source film 17a and the etched interlayer insulating film 21a. Then, the etched interlayer insulating film 21
A region from the upper surface of a to the upper surface of the diffusion region 15 via the side surfaces of the etched interlayer insulating film 21a and the etched diffusion source film 17a remains around the opening 29.
The size of the opening 29 is smaller than the diffusion region 15.
That is, when a cross section in a certain direction is taken, the width of the opening 29 is smaller than the width of the diffusion region 15. In this case, the ZnO / SiO ₂ mixed film as the diffusion source film 17 and the SiN film as the interlayer insulating film 21 have corrosion resistance to hot phosphoric acid used when patterning the aluminum film or the aluminum alloy film.

Next, as in the first embodiment, a p-side electrode film 23 is formed in a region from the etched interlayer insulating film 21a to the diffusion region 15 exposed to the opening 29. In the second embodiment, the etched interlayer insulating film 2
1a, the side surface of the etched interlayer insulating film 21a exposed in the opening 29, the side surface of the etched diffusion source film 17a exposed in the opening 29, and the surface of the substrate 11 exposed from the opening 29 (that is, the diffusion region). P to cover
The side electrode film 23 is formed. In the third embodiment, the etched diffusion source film 17a and the etched interlayer insulating film 21a function as an interlayer insulating film.

Next, as in the first embodiment, the p-side electrode film 23 is etched to form the p-side electrode 23a, and then the n-side electrode 25 is formed.
(B)). Thus, a light emitting diode array was manufactured.

When a light emitting diode is manufactured as described above, the same effects as in the first embodiment can be obtained.

It is clear that the present invention is not limited to the embodiments described above. For example, in these embodiments, a GaAsP epitaxial substrate is used as a substrate. However, for example, a GaAlAs substrate, a GaP substrate, a GaAsInP substrate, or the like may be used. Further, a p-type substrate may be used as the substrate.

[0065]

As is apparent from the above description, according to the first to third methods for manufacturing a light emitting diode of the present invention, when an aluminum electrode or an aluminum alloy electrode is provided in a region where an electrode is to be provided, an aluminum film is formed. Alternatively, the aluminum film is etched. When etching the aluminum film or the aluminum film, hot phosphoric acid is used.

In the first method for manufacturing a light emitting diode, an aluminum electrode or an aluminum alloy electrode is provided on an interlayer insulating film having corrosion resistance to hot phosphoric acid. Therefore, when the aluminum film or the aluminum alloy film is etched, the interlayer insulating film is not damaged, and the short circuit between the aluminum electrode or the aluminum alloy electrode and the substrate portion other than the diffusion region can be prevented.

Also in the second method, an aluminum electrode or an aluminum alloy electrode is provided on the diffusion source film having corrosion resistance to hot phosphoric acid. Therefore, when the aluminum film or the aluminum film is etched, the diffusion source film functioning as an interlayer insulating film is not damaged, and the aluminum electrode or the aluminum alloy electrode is formed on the substrate other than the diffusion region as in the first method. It is possible to prevent a short circuit with the part.

Also in the third method, an aluminum electrode or an aluminum alloy electrode is provided on each layer from the diffusion source film provided above the diffusion region to the interlayer insulating film, which has corrosion resistance to hot phosphoric acid. Therefore, when etching the aluminum film or aluminum alloy film,
Each layer from the diffusion source film functioning as an interlayer insulating film to the interlayer insulating film is not damaged, and similarly to the first method, it is possible to prevent the aluminum electrode or the aluminum alloy electrode from being short-circuited with the substrate portion other than the diffusion region. Can be prevented.

Further, in the light emitting diode manufactured by the first to third manufacturing methods, no damage occurs to the interlayer insulating film when the aluminum electrode or the aluminum alloy electrode is formed. Therefore, the electric characteristics of the light emitting diode are good.

[Brief description of the drawings]

FIGS. 1A to 1C are manufacturing process diagrams of a light emitting diode of a first embodiment.

FIGS. 2A to 2C are manufacturing process diagrams of the light-emitting diode of the first embodiment following FIG.

FIG. 3 is a manufacturing process diagram of the light-emitting diode of the first embodiment, following FIG. 2;

FIGS. 4A and 4B are manufacturing process diagrams of a light emitting diode of a second embodiment.

FIGS. 5A to 5C are manufacturing process diagrams of the light emitting diode of the third embodiment.

FIGS. 6A to 6C are manufacturing process diagrams of the light-emitting diode of the third embodiment, following FIG.

[Explanation of symbols]

 11: Compound semiconductor substrate 13: Diffusion mask 13a: Diffusion window 15: Diffusion region 17: Diffusion source film 17a: Etched diffusion source film 19: Annealed cap film 19a: Etched cap film 21: Interlayer insulating film 21a: Etched interlayer Insulating films 21b, 27, 29: opening 23: p-side electrode film 23a: p-side electrode 25: n-side electrode

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-56967 (JP, A) JP-A-7-15034 (JP, A) JP-A-62-16573 (JP, A) JP-A 53-569 74360 (JP, A) JP-A-62-139320 (JP, A) JP-A-62-60053 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 33/00

Claims (4)

(57) [Claims] A first conductivity type compound semiconductor substrate; a second conductivity type diffusion region formed by selectively diffusing impurities from the diffusion source film into the compound semiconductor via a diffusion mask; A method for manufacturing a light-emitting diode, comprising: an interlayer insulating film provided on an upper side of the compound semiconductor substrate; and an electrode formed from a surface of the diffusion region to a surface of the interlayer insulating film. Forming the diffusion mask having a diffusion window exposing the impurity diffusion scheduled region with a film having corrosion resistance to a first etchant capable of etching the diffusion source film; and forming the diffusion mask on the diffusion mask. After sequentially forming a diffusion source film and an annealing cap film, by diffusing impurities from the diffusion source film into the compound semiconductor substrate by heat treatment, Forming a serial diffusion region, then to remove the said annealing cap film,
Removing the diffusion source film using the first etchant; and then etching the diffusion mask and the electrode on the diffusion mask and on the diffusion region exposed from the diffusion window. Forming the interlayer insulating film with a film having corrosion resistance to an etchant; and thereafter, arranging electrodes from the upper surface of the diffusion mask to the upper surface of the diffusion region via the side surface of the diffusion mask on the side of the diffusion window. Etching and removing the interlayer insulating film so that at least the interlayer insulating film portion of the region remains; After the formation, the electrode film is removed using the second etchant so that the electrode film in the region where the electrode is to be provided is left. More, the manufacturing method of light-emitting diodes, which comprises a step of forming the electrode. 2. The method according to claim 1, wherein the diffusion mask is an AlN film, the diffusion source film is a ZnO film or a ZnO / SiO ₂ mixed film, and the interlayer insulating film is a SiN film, a SiO ₂ film, a PSG film,
1 of BSG film, ZnO film and ZnO / SiO ₂ mixed film
The method for manufacturing a light emitting diode according to claim 1, wherein the electrode is a film including at least one kind, and the electrode is an aluminum film or an aluminum alloy film. 3. A step of forming a diffusion mask having a diffusion window exposing a diffusion region of an impurity on a compound semiconductor substrate of the first conductivity type, and thereafter, a ZnO film or a ZnO /
Forming a diffusion source film composed of a SiO ₂ mixed film and an annealing cap film sequentially, and then diffusing Zn from the diffusion source film into the compound semiconductor substrate by heat treatment to form a diffusion region of the second conductivity type; Then, the annealing cap film and the annealing cap film so that at least the diffusion source film portion of the electrode arrangement planned region extending from the upper surface of the diffusion mask to the upper surface of the diffusion region through the side surface of the diffusion mask on the side of the diffusion window is left. Etching the diffusion source film; thereafter, forming an aluminum film or an aluminum alloy film on the remaining diffusion source film portion, on the remaining annealing cap film portion and on the diffusion region; The aluminum film or aluminum alloy portion of the area to be set is left so that the aluminum film portion or aluminum alloy film portion remains. The Miniumu alloy film is removed by etching, a method of manufacturing a light emitting diode which comprises a step of forming an aluminum electrode or aluminum alloy electrode. 4. A step of forming a diffusion source film containing an impurity of the second conductivity type in an impurity diffusion region on the compound semiconductor substrate of the first conductivity type, and thereafter annealing to cover the diffusion source film. After forming the cap film, a step of diffusing the impurities from the diffusion source film into the compound semiconductor substrate by heat treatment to form a diffusion region of the second conductivity type, and then, on the upper side of the diffusion source film, S covering the diffusion source film
forming an interlayer insulating film composed of at least one film selected from an iN film, a SiO ₂ film, a PSG film, a BSG film, a ZnO film, and a ZnO / SiO ₂ mixed film; The diffusion region provided above the diffusion region so that at least the region where an electrode is to be provided from the upper surface to the upper surface of the diffusion region through the side surface of each layer from the interlayer insulating film to the diffusion source film remains at least. A step of etching and removing each layer from a source film to the interlayer insulating film; and thereafter, a step of forming an aluminum film or an aluminum alloy film in a region from the remaining interlayer insulating film portion to the diffusion region, The aluminum film or the aluminum alloy film is etched so as to leave the aluminum film portion or the aluminum alloy film portion in the electrode arrangement region. Forming an aluminum electrode or an aluminum alloy electrode by removing the ring.