JPS63140520A - Heteroepitaxy method of gaas on different type substrate - Google Patents

Abstract

PURPOSE:To make GaAs with very few dislocation grow on a different type substrate by heteroepitaxy by doping the GaAs with an impurity at the time of epitaxy. CONSTITUTION:An Si substrate is used as a substrate. In is employed as a dopant and added to GaAs with a concentration of about 5X10<19>cm<-3>. As a dislocation caused by a stress is difficult to be introduced into the GaAs by adding In with the concentration of about 5X10<19>cm<-3>, when the GaAs is made to grow by heteroepitaxy on the Si substrate which has a lattice constant and a thermal expansion coefficient different from those of the GaAs, a crystal in which very few dislocations are induced even if a stress is created can be obtained. It is to be noted that the substrate can be made of other materials such as Ge. Also, if a donor impurity such as S or Si is employed, the same effect can be obtained. The impurity concentration of 5X10<18>cm<-3> or higher is effective.

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention is applicable to GaA on heterogeneous substrates such as 81 substrates.
The present invention relates to a g-heteroepitaxy method, and in particular to a method capable of achieving low dislocations in GaAs crystals.

[Conventional technology]

The figure is, for example, Applied F. Physics Letter No. 45.
Volume (Appl, Phys, Lett, Vol, 45)
(1984) P.

1107 is a cross-sectional transmission micrograph of additive-free GaAII formed heteroepitaxially on the 81 substrate by the conventional technique shown in FIG.

In this photo, dislocations occur from the interface between GaAs and Sl.
The figure shows the propagation into the inside of the GaA layer. This dislocation occurs because stress is generated because GaAs and 81 have different lattice constants and coefficients of thermal expansion.

[Problems that the invention attempts to solve]

In this way, when undoped GaAs is heteroepitaxially grown on a foreign substrate, the substrate and GaAs generally have different lattice constants and coefficients of thermal expansion, and stress is generated. Since this phenomenon easily occurs, there is a problem in that the resulting crystal contains a large number of dislocations.

This invention was made to solve the above-mentioned problems, and aims to provide a method for heteroepitaxial growth of GaAs1 on a heterogeneous substrate with fewer dislocations.

[Means for solving the four points between]

Bottle - The alloepitaxy method for GaAs on a heterogeneous substrate according to the present invention is to add impurities when growing GaAs heteroepitaxially on a heterogeneous substrate.

[Effect]

GaAs i on a heterogeneous substrate grown using this method, doping with impurities makes it difficult for dislocations to occur in response to stress.
This results in a low dislocation density.

[Embodiments of the invention]

Hereinafter, a weaving example of the present invention will be explained.

A 31 substrate was used as the substrate, and In was used as the added impurity.
5 x 10” am-!54Jj on GaAs using
Add degree A.

By adding about 5 x 10"am" of In to GaAs, dislocations are less likely to be introduced due to stress, so when GaAs is heteroepitaxially grown on an 81 substrate having a different lattice constant and coefficient of thermal expansion than GaAs, Even if stress occurs, a crystal with few dislocations can be obtained.

In addition, although the 81 substrate was used as the substrate in the above-mentioned ceramic example, other materials such as Go may be used as the substrate. Further, in the above embodiment, isoelectronic In was used as the impurity, but the same effect can be obtained by using S, Si, etc. as the donor impurity. The impurity concentration is 5 x 1010
1aa' or more is effective.

〔Effect of the invention〕

As described above, according to this method, the addition of impurities gives GaAs a property that makes it difficult to introduce dislocations under stress, and GaAs grown on a foreign substrate can have low dislocations. effective.

[Brief explanation of the drawing]

The figure is a cross-sectional transmission micrograph of additive-free GaAs grown heteroepitaxially on an 81 substrate using the conventional technique.

Claims (1)

[Claims] A method for heteroepitaxially growing GaAs on a substrate other than GaAs, characterized in that impurities are added to the growth layer when GaAs is heteroepitaxially grown on a substrate other than GaAs.