Patent ID: 6451703
Filing Date: 2002-09-17
Classification: H01L

Abstract:
A method for etching an oxide layer with increased selectivity to photoresist, comprising the steps of:providing a magnetically enhanced plasma etch reactor chamber having a pedestal electrode supporting a substrate having said oxide layer to be etched; flowing into said chamber an etching gas mixture comprising (a) hexafluorobutadiene, (b) oxygen, and (c) a chemically inactive carrier gas selected from the group consisting of argon and xenon and containing essentially no carbon monoxide; applying a magnetic field substantially parallel to said pedestal electrode; and applying RF electrical power to said pedestal electrode to provide the only significant power to excite said etching gas mixture into a plasma to thereby etch a hole into said oxide layer defined by a patterned photomask comprising photoresist overlying said oxide layer with an etching selectivity to a facet of said photoresist of at least 5:1.