Method of forming a field effect transistor having a stressed channel region

摘要

A semiconductor structure comprises a transistor element formed in a substrate. A stressed layer is formed over the transistor element. The stressed layer has a predetermined compressive intrinsic stress having an absolute value of about 1 GPa or more. Due to this high intrinsic stress, the stressed layer exerts considerable elastic forces to the channel region of the transistor element. Thus, compressive stress is created in the channel region. The compressive stress leads to an increase of the mobility of holes in the channel region.