EFFECTS OF INGAAS GAAS STRAINED-LAYER SUPERLATTICES IN OPTIMIZED MOLECULAR-BEAM-EPITAXY GAAS AN SI WITH SI BUFFER LAYERS/

The effectiveness of In0.10Ga0.90As/GaAs strained-layer superlattices (SLSs) as barriers for the threading dislocation propagation, in molec ular-beam-epitaxy GaAs-on-Si structures with Si buffer layers, has bee n investigated. It is shown that the interaction of threading dislocat ions with the strain field of SLSs is effective in limiting their prop agation. The interaction is stronger as the total thickness of In0.10G a0.90As (i.e., SLS periods) is increased. SLSs with thinner individual layers resulted in a lower dislocation density and a better structura l quality at the GaAs/Si interface. (C) 1994 American Institute of Phy sics.