IN-SITU RELAXED SI1-XGEX EPITAXIAL LAYERS WITH LOW THREADING DISLOCATION DENSITIES GROWN ON COMPLIANT SI-ON-INSULATOR SUBSTRATES

High quality relaxed Si0.6Ge0.4 films as thick as 1.0 mu m have been a chieved as grown on silicon-on-insulator (SOI) substrates with 200 Ang strom Si(100)-oriented compliant substrates. This represents the thick est relaxed layers grown by this technique. A greater than five order of magnitude reduction in threading dislocation density was achieved b y compliant growth compared to growth on unmodified Si(100) substrates . Additionally, for the first time (to the best of our knowledge) we s how that it is not necessary to separate the growth and relaxation pro cesses, and relaxation during growth is governed by the nature of the compliant substrate structure that causes dislocations to terminate at the unique crystalline-amorphous SiO2 interface. Results indicate tha t utilizing SOI as a compliant substrate which is effective in produci ng high quality Si1-xGex films can be extended to other films, where f ilm relaxation (via dislocation nucleation and growth) cannot be conve niently separated,from the synthesis method (e.g., SiC). (C) 1998 Amer ican Vacuum Society.