Patent ID: 6436841
Filing Date: 2002-08-20
Classification: H01L

Abstract:
A method of forming a borderless contact, comprising the steps of:providing a substrate having an exposed conductive structure; forming an oxynitride etch stop layer over the substrate and the exposed conductive structure; forming an oxide dielectric layer over the oxynitride etch stop layer; etching the oxide dielectric layer with an etch process wherein the oxide dielectric layer is etched at a greater rate than oxynitride etch stop layer to form a contact hole therein exposing a portion of the oxynitride etch stop layer over at least a portion of the exposed conductive structure; the etch process not etching the oxynitride etch stop layer and including: a fluorine containing gas CxFy selected from the group consisting of C4F8, C5F8, C4F6, C3F8 and C3F6; an inert gas selected from the group consisting of Ar, He and Ne; and an oxidant selected from the group consisting of CO, O2 and CO plus O2; wherein the etch process is conducted at the following parameters: a total pressure of from about 1 to 1000 mTorr; top and bottom RF power of each from about 500 to 5000 watts; a reactor temperature of from about âˆ’30 to 60Â° C.; a CxFy gas flow of from about 5 to 50 sccm; a CO gas flow of from about 50 to 1000 sccm; an O2 gas flow of from about 2 to 50 sccm; an Ar gas flow of from about 50 to 1000 sccm; and an He gas flow of from about 50 to 1000 sccm;removing the exposed portion of the oxynitride etch stop layer over at least a portion of the conductive structure; and forming a borderless contact within the contact hole; the borderless contact in electrical connection with at least a portion of the conductive structure.