Patent ID: 6497993
Filing Date: 2002-12-24
Classification: H01L

Abstract:
A method of forming a contact hole opening in a composite dielectric layer on a semiconductor substrate, comprising the steps of:providing a conductive region on said semiconductor substrate; forming a composite dielectric layer on said conductive region with said composite dielectric layer comprised of an underlying first insulator layer, a dielectric layer located on said underlying first insulator layer, and an overlying hard mask insulator layer located on said dielectric layer; forming a photoresist shape on said overlying hard mask insulator layer with an opening in said photoresist shape exposing a portion of the top surface of said overlying hard mask insulator layer; performing a first dry etch procedure in a dry etching chamber using said photoresist shape as an etch mask, forming an opening in said overlying hard mask insulator layer; removing said photoresist shape in situ in said dry etching chamber; performing a second dry etch procedure in said dry etching chamber, using said opening in said overlying hard mask insulator layer as an etch mask, forming an opening in said dielectric layer, and resulting in thinning of said hard mask insulator layer; and performing a third dry etch procedure in said dry etching chamber using thinned, overlying hard mask insulator layer as an etch mask, forming an opening in said underlying insulator layer, and completely removing said thinned overlying hard mask insulator layer, resulting in formation of said contact hole opening in said dielectric layer and in said underlying insulator layer, exposing said portion of top surface of said conductive region.