Reactions of Gallium with Quartz and with Water Vapor, with Implications in the Synthesis of Gallium Arsenide

Abstract

The reaction of gallium with quartz to produce gallium suboxide, , and silicon is shown by equilibrium calculations to be a mechanism by which gallium arsenide can become contaminated with silicon, and possibly oxygen, when synthesized in quartz systems. The contamination of gallium arsenide with silicon by this reaction is governed by the rate at which the gallium suboxide vapor is removed. The silicon content commonly observed in (up to a few ppm) can be accounted for by this mechanism. Suggestions for minimizing the attack are given. The apparent transport of in a system containing traces of water vapor can be explained by reaction of water with gallium in the hot zone to form and hydrogen, which react with arsenic in the cold zone to produce and regenerate the water.