Method of making a compound semiconductor device

Abstract

A process for epitaxially growing a compound semiconductor layer containing at least arsenic on a single crystal silicon substrate, which prevents the silicon impurity from intruding said compound semiconductor layer. The process comprises supplying one of the starting material gas, ASH.sub.3, into the reaction furnace to effect growth, but in such a manner that the AsH.sub.3 gas is pyrolyzed in advance to thereby supply arsenic alone either in an atomic or a molecular state. The GaAs layer is thus epitaxially grown on a single crystal silicon substrate in the crystal growing chamber, i.e., the reaction furnace in the apparatus, under an atmosphere comprising atomic or molecular arsenic at a temperature in the range of from 400.degree. to 650.degree. C. and at a vacuum degree of about 0.1 Pa. By thus epitaxially growing GaAs layer under an atmosphere comprising atomic or molecular arsenic, the intrusion of silicon impurity into the GaAs layer during its growth can be effectively prevented. Furthermore, an undoped GaAs layer, a p-GaAs layer, and an n-GaAs layer in this order can be deposited on the silicon substrate consecutively by using carbon (C) as a p-type dopant which can be supplied from trimethylgallium, thereby realizing a steep step-like junction at the n-GaAs/p-GaAs interface.