Process for growing gallium phosphide and gallium arsenide crystals from a ga o and hydrogen vapor mixture

摘要

A crystal of gallium phosphide or gallium arsenide or a mixture thereof is grown on a crystalline semi-conductor substrate by a process comprising passing over the substrate a gas stream consisting of hydrogen containing from 10-4 to 1 atmosphere of water vapour, Ga2O and P or As or both, optionally an impurity vapour and optionally an inert diluent gas, the gas stream temperature being at least 700 DEG C., and the substrate being maintained at a temperature below the lowest saturation temperature of the vapour constituents of the gas stream. Examples relate to forming the initial gas mixture by passing H2/H2O over S and over GaP; by passing H2/H2O over GaAs; by passing H2/H2O over GaP; by passing CO2/H2 over GaP; by passing H2 over P2O5 and over Ga; by passing H2 over ZnO and over GaP; by passing H2/H2O over GaAs and then over GaP. Other source materials referred to are gallium oxide; arsenic oxide, elemental arsenic or phosphorus, metal arsenides or phosphides. Substrate materials are GaP, GaAs, Mg-doped GaP.