Patent ID: 7291550

Claim:
A method of forming a contact opening; comprising the steps of: a) providing a gate structure over a substrate; the gate structure having gate structure sidewalls; b) forming a nitride liner over said gate structure and said substrate; the nitride liner having sidewalls; c) providing a dielectric layer over the nitride liner; d) forming a contact photoresist pattern over the dielectric layer; e) performing a contact opening etch by etching the dielectric layer to form a contact opening and a residual spacer; said contact opening exposes portions of said nitride liner over said gate structure sidewalls and over said substrate adjacent to said gate structure; said residual spacer is over the sidewalls of said nitride liner; f) striping said contact photoresist pattern; g) performing a plasma treatment comprising gases containing fluorine, nitrogen and hydrogen to deposit a by-products layer over said residual spacer and said dielectric layer; and h) removing said by-products layer and said residual spacer.