Patent ID: 6140024
Filing Date: 2000-10-31
Classification: H01L

Abstract:
A low temperature method of forming an opening through an oxide layer down to a silicon wafer surface without exposing the silicon wafer surface to contamination from photoresist stripping subsequent to completion of said opening to said wafer surface, said method comprising the steps of:providing a silicon wafer having a surface containing a region of oxide on said surface;exposing said region of oxide to a nitrogen ion containing plasma to form a nitrided layer on said region of oxide;providing and patterning photoresist over said nitrided layer;then etching said nitrided layer in accordance with the pattern of said photoresist on said nitrided layer with an etchant selective to the nitride relative to the oxide;then removing all of said photoresist; andthen etching said oxide down to the silicon beneath said oxide using said nitrided layer as a mask.