Method for fabricating CMOS transistor

摘要

A method for fabricating MOS transistor includes the steps of: overlapping a second stress layer on an etching stop layer and a first stress layer at a boundary region of the substrate; forming a dielectric layer on the first stress layer and the second stress layer; performing a first etching process to partially remove the dielectric layer for exposing a portion of the second stress layer at the boundary region; performing a second etching process to partially remove the exposed portion of the second stress layer for exposing the etching stop layer; performing a third etching process to partially remove the exposed portion of the etching stop layer for exposing the first stress layer at the boundary region; and performing a fourth etching process partially remove the exposed portion of the first stress layer.