Chemical vapour transport reactions of III-V compound semiconductors

The chemical vapour transport reactions of some Group III-V semiconductors with hydrogen halides have been studied hy a modified entrainment method. Enthalpies and entropies for the transport reactions in the systems: indium arsenide-hydrogen bromide, indium arsenide-hydrogen chloride and gallium arsenide-hydrogen bromide were calculated. The effect of surface kinetics on the rate of transport of gallium arsenide by hydrogen bromide gas was investigated. Binary diffusion coefficients for hydrogen bromide and hydrogen chloride gases in hydrogen have been obtained by a study of the transport of indium in hydrogen bromide or hydrogen chloride under limiting equilibrium conditions. Using literature results for the temperature dependence of the vapour pressure of zinc, the binary diffusion coefficients of zinc atoms in helium and in argon over the temperature range 850 - 1120 K were determined. A modified entrainment method apparatus was used to monitor the evaporation of zinc in the inert gas.