GaAs single crystal and preparation thereof

摘要

A GaAs single crystal is disclosed containing at least one impurity selected from the group consisting of In, Al, C and S, in which fluctuation of the concentration of the impurity is less that 20% throughout the crystal from which wafers having uniform characteristics can be produced, and which may be prepared by a process comprising, at a high temperature and under high pressure, pulling up the single crystal from a raw material melt containing simple substances Ga and As or GaAs compound as well as at least one impurity while controlling the concentration of As so as to keep a distribution coefficient of the impurity in GaAs within 1+/-0.1.