Patent ID: 6323121
Filing Date: 2001-11-27
Classification: H01L

Abstract:
A method for patterning and cleaning a via opening comprising:(a) providing a wafer having an etch stop over a metal pattern and an insulative layer over said etch stop;(b) patterning a photoresist mask on said insulative layer to define a via opening;(c) anisotropically etching said insulative layer to said etch stop thereby forming a via opening;(d) ashing said wafer in a plasma containing oxygen and nitrogen;(e) after step (d) and without breaking vacuum, removing said etch stop at the base of said via opening by plasma etching in an etchant gas plasma containing fluorocarbons whereby a polymeric residue is formed by attack of said etchant gas plasma on said metal pattern which is exposed by said etching; and(f) after step (e) and without breaking vacuum, subjecting said wafer to a hydrogen plasma treatment thereby removing said polymeric residue.