Patterned silicon substrate-silicon germanium, thin film composite structure and preparation methods and application thereof

Abstract

The present invention provides a patterned silicon substrate-silicon germanium thin film composite structure comprising a silicon substrate having a patterned structure, a silicon germanium buffer layer positioned on the silicon substrate, a silicon germanium/silicon superlattice layer positioned on the silicon germanium buffer layer and a silicon germanium thin film layer positioned on the silicon germanium/silicon superlattice layer, wherein the silicon germanium/silicon superlattice layer comprises silicon germanium layers and silicon layers which are grown alternately. The present invention also provides a preparation method of the patterned silicon substrate-silicon germanium thin film composite structure of the present invention. The present invention also provides an application of the patterned silicon substrate-silicon germanium thin film composite structure of the present invention in strained silicon devices. The patterned silicon substrate-silicon germanium thin film composite structure provided by the present invention has low threading dislocation density and low surface roughness. A strained silicon device fabricated based on the silicon germanium thin film layer can effectively reduce the scattering of defects to carriers, thereby improving carrier mobility.

Dependencies are inferred from the claim text.