Method and structure for forming self-aligned, dual stress liner for CMOS devices

摘要

A method for forming a self-aligned, dual stress liner for a CMOS device includes forming a first type stress layer over a first polarity type device and a second polarity type device, and forming a sacrificial layer over the first type nitride layer. Portions of the first type stress layer and the sacrificial layer over the second polarity type device are patterned and removed. A second type stress layer is formed over the second polarity type device, and over remaining portions of the sacrificial layer over the first polarity type device in a manner such that the second type stress layer is formed at a greater thickness over horizontal surfaces than over sidewall surfaces. Portions of the second type stress liner on sidewall surfaces are removed, and portions of the second type stress liner over the first polarity type device are removed.