Electronic GaAs-on-silicon material for advanced high-speed optoelectronic devices

A new technology for the heteroepitaxial growth of GaAs films on silicon substrates is developed. The process utilizes a combined close-spaced vapor transport (CSVT) and liquid-phase epitaxy (LPE) technique. A thin film of GaAs is grown directly on silicon by a close-spaced vapor transport reaction using water vapor as the transport agent. This initial layer is used to seed the subsequent growth of additional layers of GaAs or AlGaAs by LPE. Selective modes of growth on oxide-masked silicon substrates were optimized. Stable light-emitting diodes were fabricated in GaAs-on-silicon material. The process is being scaled for 3-inch diameter substrates.