Very low dislocation density GaAs on Si using superlattices grown by MOCVD

Abstract

GaAs was grown on Si substrates by metalorganic chemical vapor deposition using GaAs/GaAsP strained layer superlattice (SLS) intermediate layers. The dislocation density decreases at the interface between the GaAs and the SLS, hence for maximum effect GaAs was grown on Si using three SLSs separated by GaAs layers. A low etch pit density GaAs-on-Si of the order of 10 5 cm -2 was obtained by using an intermediate layer of GaAs/GaAsP SLSs, an AlAs/GaAs superlattice and thermal-cycle annealing.