US Patent 7642147 Methods for removing sidewall spacers

A method for removing sidewall spacers. The method includes: (a) forming a gate stack on a substrate; after (a), (b) forming dielectric spacers on sidewalls of the gate stack; after (b), (c) forming a dielectric sacrificial layer over the substrate and on the gate stack where the substrate and the gate stack are not covered by the spacers; and after (c), (d) removing the sacrificial layer and the spacers in a etch process by etching the sacrificial layer until the spacers are exposed and thereafter simultaneously etching the sacrificial layer and the spacers until the sacrificial layer and the spacers are removed. Methods for spacer removal from PFETs when a stress layer is formed over the NFETs are also disclosed.