Characterization ofGaAs-AlGaAs Heterostructures Grown on Si by MOCVD

High quality, 2" diameter, MO-CVD GaAs-on-Si wafers grown by direct deposition of 4 um GaAs layers onto Si substrates oriented 2 off (100) - (110). The surfaces were near-specular and the minority carrier lifetime in the GaAs was comparable in both magnitude and uniformity to bulk GaAs of the same doping density. RBS revealed a stoichiometric near-surface region with crystallinity identical to bulk material. However the backscattering yield rose more rapidly near the GaAs-Si interface indicating an increasing level of disorder.