Patent ID: 6372634
Filing Date: 2002-04-16
Classification: H01L

Abstract:
A method of forming openings within a material across a semiconductor topography on a wafer, comprising:exposing portions of an upper surface of said material through photoresist openings of a photoresist layer arranged upon said material; etching the exposed portions with an etchant mixture comprising a first etchant of the formula CxHyFz (where x&gE;2, y&gE;1 and z&gE;2) and a second etchant other than the first etchant to form said openings within the material under conditions providing at least 95% of said openings has a lateral dimension that varies across the wafer by less than a critical variation; and forming a carbon containing residue to a greater extent upon sidewall surfaces of photoresist openings proximate edges of the wafer than upon sidewall surfaces of photoresist openings proximate a center of the wafer.