Analysis of the Main Factors Influencing the Thickness Uniformity of VPE GaAs Thin Layers

It is shown that the homogeneity in thickness of a large area GaAs thin layer obtained by VPE is a function of the composition of the gaseous phase, its homogeneity and the hydrodynamics of its flow in the vicinity of the substrate. The influence of each of these factors has been investigated. Modifications have consequently been introduced into the low temp. growth technique using AsCl3/H2 /GaAs which lead to very uniform layers with a pinch-off voltage variation of plus/minus 5% for FET.13 refs.--AA