Ge/Si superlatices grown on thin relaxed GeSi alloy buffer with Ge islanding buried layer

A thin Ge islanding film inserted between SiGe buffer layer and Si substrate may greatly reduce the necessary buffer thickness to 100-200 nm maintaining the same good crystal quality. A very favorite property of Ge4/Si6 short-period superlattices successively grown on the 150 nm GeSi alloy buffers with 1 nm Ge islanding layer inserted shows that the Ge island method is valid.