Patent ID: 6140218
Filing Date: 2000-10-31
Classification: H01L

Abstract:
A method for fabricating a T-shaped hard mask/conductive pattern profile comprising the steps of:a) providing a substrate having thereover a conductive layer; said conductive layer comprising a polysilicon layer with an overlying tungsten silicide layer;b) forming a hard mask layer on said conductive layer; said hard mask layer comprising silicon oxynitride;c) patterning said hard mask layer to form a hard mask pattern having a hard mask pattern width; andd) etching said conductive layer to form a conductive pattern having a conductive pattern width which is smaller than said hard mask pattern width using a Cl.sub.2 and He--O.sub.2 chemistry without a Br-containing gas to etch said tungsten silicide layer and using a Cl.sub.2, HBr, and He--O.sub.2 chemistry to etch said polysilicon layer; thereby increasing a self-aligned contact window and improving a self-aligned contact isolation.