Method for fabricating strained-silicon cmos transistors

Abstract

A semiconductor substrate having a first active region and a second active region for fabricating a first transistor and a second transistor is provided. A first gate structure and a second gate structure are formed on the first active region and the second active region and a first spacer is formed surrounding the first gate structure and the second gate structure. A source/drain region for the first transistor and the second transistor is formed. The first spacer is removed from the first gate structure and the second gate structure and a cap layer is disposed on the first transistor and the second transistor and the cap layer covering the second transistor is removed thereafter. An etching process is performed to form a recess in the substrate surrounding the second gate structure. An epitaxial layer is formed in the recess and the cap layer is removed from the first transistor.