JPS5918855B2 - 3-Method for forming selective impurity diffusion regions in V group compound semiconductors - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides the following method: ■--A mask for impurity diffusion is attached on a group V compound semiconductor, and the mask for diffusion of impurities is used as a mask.
- Performing selective impurity diffusion treatment on the V group compound semiconductor, ■ - Into the V group compound semiconductor from its main surface side,
The present invention relates to an improvement in a method for forming a selective impurity diffusion region in a ①-V group compound semiconductor for forming an impurity diffusion region.

Such a method of selectively forming an impurity diffusion region in a -V group compound semiconductor is applied, for example, to a method of manufacturing a current confinement type double heterojunction semiconductor light emitting device, as described below with reference to FIGS. ing.

That is, as shown in FIG. 1A, on an N-type substrate 1 made of GaAs, AlXGa, -xAs (where 0<X<1
) N-type confinement layer 2 consisting of Ga-As or AlyG
An active layer 3 made of al-yAs (where Y≦x≦10,25), a P-type confinement layer 4 made of AIXGa1×xAs, and an N-type electrode attachment layer 5 made of GaAs are formed in that order. As shown in FIG. 1B, a layer T made of a mask material for impurity diffusion is applied on the upper surface of the laminate 6 which has been obtained in advance. Next, as shown in FIG. 1C, a stripe-shaped window 8 is formed in this layer T by photolithography, and an impurity diffusion mask 9 is formed from the layer T.
form.

Next, using this impurity diffusion mask 9 as a mask, a P-type impurity diffusion process is performed to form a confinement layer 4 into the laminate 6 from the upper surface side, as shown in FIG. 1D. A striped P with a depth of
A type impurity diffusion region 11 is formed.

Next, as shown in FIG. 1E, the impurity diffusion mask 9 is removed.

Thereafter, as shown in FIG. 1F, the confinement layer 2 of the substrate 1 is
Electrodes 11 and 12 are respectively attached to the side opposite to the confinement layer 4 side and the side of the electrode attachment layer 5 opposite to the confinement layer 4 side.

As described above, a current confinement type double heterojunction semiconductor light emitting device having one purpose is manufactured.

By the way, in the above-described conventional method for manufacturing a current confinement type double heterojunction semiconductor light emitting device, the impurity diffusion mask 9 used to obtain the P-type impurity diffusion region 10 is
However, it was usually composed of oxides such as silicon dioxide and silicon monoxide, or nitrides such as trisilicon tetranitride.

However, as a result of various experiments conducted by the present inventors, it has been found that when the impurity diffusion mask 9 is made of the above-mentioned oxide, oxygen constituting the oxide invades into the stack 6 during the impurity diffusion process. However, it has been found that this causes defects in the layer into which oxygen is introduced.

Further, although it is undeniable that crystal distortion is imparted to the laminate 6 because the impurity diffusion mask 9 is attached on the laminate 6, when the impurity diffusion mask 9 is made of oxide, It has also been found that crystal strain occurs within the laminate 6, which cannot be ignored.

Furthermore, it has been found that even when the impurity diffusion mask 9 is made of the above-mentioned nitride, the above-mentioned crystal strain occurs in the stacked body 6 in a non-negligible manner. On the other hand, the present inventors believe that if oxygen is included in the impurities during the impurity diffusion process, the oxygen will be included in the impurity diffusion region 10, and furthermore, the oxygen thus included will be absorbed into the stack. In any case, defects will occur in the stacked body 6.
If oxygen is included in the laminate 6, it means that the laminate 6 has a defect. However, if it is removed, the above-mentioned defects will not occur.
It took me a while to remember that. In addition, based on this idea, the present inventors have conducted various experiments and found that when the impurity diffusion mask 9 is made of aluminum metal, it is easily oxidized. As a result, it has been confirmed that oxygen contained in impurities and oxygen contained in the laminate 6 can be effectively removed.

Furthermore, as a result of various experiments conducted by the present inventors, when an impurity diffusion mask made of aluminum metal is used as the impurity diffusion mask 9, since it is not an oxide, oxygen is not absorbed into the stacked body 6 during the impurity diffusion process. Therefore, the above-mentioned defects that occur when the impurity diffusion mask 9 is made of oxide do not occur, and even though it is undeniable that crystal strain is imparted to the laminate 6, the impurity diffusion does not occur. We have come to the conclusion that as a result of the above, the distortion is significantly reduced and can be ignored compared to when the mask 9 is made of oxide or nitride.

Furthermore, as a result of various experiments conducted by the present inventors, it has been found that an impurity diffusion mask made of aluminum metal is applied to perform selective impurity diffusion processing on a semiconductor, and impurity diffusion regions are selectively formed within the semiconductor. In this case, it has been confirmed that, as long as the semiconductor is a -V group compound semiconductor, the advantages of the above-mentioned impurity diffusion mask made of aluminum metal can be obtained.

Therefore, the present inventors have proposed the invention described in the claims as an invention according to the present invention.

Next, an example in which the present invention is applied to the method for manufacturing the current confinement type double heterojunction semiconductor light emitting device described above with reference to FIG. 1 will be described as follows.

That is, as shown in FIG. 1B, a layer 7 made of a masking material for impurity diffusion is attached on the upper surface of the laminate 6 obtained in advance as shown in FIG. 1A, and as a masking material for impurity diffusion, Therefore, as shown in FIG. 1C, an impurity diffusion mask 9 made of aluminum metal is obtained.

Then, using this impurity diffusion mask 9 made of aluminum metal, a P-type impurity diffusion process is performed to form a P-type impurity diffusion region 10 as shown in FIG. 1D.

Next, as shown in FIG. 1E, the impurity diffusion mask 9 is removed.

Thereafter, as shown in FIG. 1F, electrodes 11 and 12 are attached to obtain the desired current confinement type double heterojunction semiconductor light emitting device.

According to the method for manufacturing the current confinement type double heterojunction semiconductor light emitting device according to the present invention, the impurity diffusion region 10 is formed in the stacked body 6 by oxygen, as is clear from the above. It has the feature that it can be easily formed without causing any underlying defects or crystal distortion due to the use of an impurity diffusion mask.

In the above description, if the manufacturing method of the current confinement type double heterojunction semiconductor light emitting device shown in FIG. 1 to which the present invention is applied includes the step of removing the impurity diffusion mask 9 (FIG. 1E) I talked about this.

However, although a detailed explanation will be omitted, in the manufacturing method described above in FIG. In addition, it is also possible to obtain a structure in which the impurity diffusion mask 9 is left and the electrode 12 is ohmicly connected to the impurity diffusion region 10 through the window 8 of the impurity diffusion mask 9.

Further, although detailed explanation is omitted, as the laminate 6, the N
A laminate in which the P-type electrode attachment layer 5 is replaced with a P-type electrode attachment layer is used, and an impurity that terminates the impurity diffusion region 10 in the P-type electrode attachment layer by impurity diffusion treatment is used. As shown in FIG.
is P type, and the impurity diffusion region 10 is the electrode attachment layer 5.
As in the case of FIG. 2, the impurity diffusion mask 9 is left on the stacked body 6 having a structure where the circuit is terminated within the impurity diffusion region 10, so that the electrode 12 is ohmicly connected to the impurity diffusion region 10. It is also possible to obtain a configuration with

Further, in the above description, the present invention has been applied to the case of manufacturing an electric field confinement type double heterojunction semiconductor light emitting device. It will be clear that the invention can be applied when forming

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the sequential steps of an example of a method for manufacturing a current confinement type double heterojunction semiconductor light emitting device to which the method of forming a selective impurity diffusion region in a -V group compound semiconductor according to the present invention is applied. be. FIGS. 2 and 3 are cross-sectional views showing examples of current confinement type double heterojunction semiconductor light emitting devices obtained by applying the present invention, respectively. 1...Substrate, 2,
4...Confinement layer, 3...Active layer, 5.
... layer for electrode attachment, 6 ... laminate, 7 ...
... Layer of mask material for impurity diffusion, 8 ... Window, 9 ... Mask for impurity diffusion, 10 ...
- Impurity diffusion region, 11, 12... electrode.

Claims (1)

[Claims] 1. An impurity diffusion mask is attached on the III-V group compound semiconductor, and the above III-
Selection into a III-V compound semiconductor in which an impurity diffusion region is selectively formed in the III-V compound semiconductor from its main surface side by performing selective impurity diffusion treatment on the V group compound semiconductor. In the impurity diffusion region formation method,
III- characterized in that an impurity diffusion mask made of aluminum metal is used as the impurity diffusion mask.
A method for forming a selective impurity diffusion region in a group V compound semiconductor.