Patent ID: 6184119
Filing Date: 2001-02-06
Classification: H01L

Abstract:
A method for forming a contact hole to a silicided semiconductor contact in an interlayer oxide layer and a nitride etch stop layer on a semiconductor wafer during semiconductor manufacturing, comprising:plasma etching a portion of the interlayer oxide layer in a predetermined configuration to form a first portion of the contact hole using a first high etch selective chemistry selective for the interlayer oxide layer relative to the nitride etch stop layer; said first high etch selective chemistry utilizing a fluorocarbon plasma having a high carbon to fluorine ratio whereby polymerization occurs forming a polymer over said first portion of the contact hole wherein said plasma etching said first portion uses a plasma with a gas mixture of C.sub.4 F.sub.8 /CF.sub.4 /CO/Ar where the C.sub.4 F.sub.8 /CF.sub.4 ratio is about 0.85;removing said polymer from said first portion of the contact hole in the interlayer oxide layer; andplasma etching a portion of the nitride etch stop layer in said predetermined configuration to form a second portion of the contact hole open to said contact using a second high etch selective chemistry selective for the nitride etch stop layer relative to the silicided semiconductor contact.