Patent ID: 6649492
Filing Date: 2003-11-18
Classification: H01L

Abstract:
A method for fabricating a strained Si based layer comprising the steps of:growing epitaxially a SiGe layer on a substrate, wherein creating a varying Ge concentration in the thickness direction of said SiGe layer, said Ge concentration having a first value at the interface with said substrate and having a second value at full thickness of said SiGe layer, said second value of Ge concentration being larger than said first value of Ge concentration, furthermore said SiGe layer imbedding a Ge overshoot zone, wherein said Ge overshoot zone having a third value of Ge concentration, said third value being larger than said second value; depositing epitaxially said Si based layer onto said SiGe layer; and transferring said strained Si based layer onto a second substrate.