Patent ID: 6458710
Filing Date: 2002-10-01
Classification: H01L

Abstract:
A method of forming a contact hole opening in an insulator layer, and in a top portion of an underlying conductive region, comprising the steps of:providing a conductive region in, or on, a substrate; depositing said insulator layer; forming a photoresist shape on said insulator layer, with an opening in said photoresist shape exposing a portion of a top surface of said insulator layer; performing a first dry etch procedure, using said photoresist shape as an etch mask, to form a tapered opening in a first portion of said insulator layer; performing a second dry etch procedure, using said photoresist shape as an etch mask, to form a straight walled opening in a bottom portion of said insulator layer; performing a third dry etch procedure, using said photoresist shape as an etch mask, to form a straight walled opening in a top portion of said conductive region, resulting in a polymer layer formed on the exposed surfaces of said tapered opening, and on the exposed surfaces of the straight walled openings; removing said photoresist shape and of said polymer layer, forming an oxide layer on the exposed surfaces of said conductive region; and performing a wet etch procedure to; remove said oxide layer from the top surface of said conductive region, to laterally etch said insulator layer exposed in tapered and straight walled openings, and to remove a portion of the top surface of said insulator layer, resulting in said contact hole opening comprised of a laterally recessed tapered opening in a top portion of a thinned insulator layer, a laterally recessed straight walled opening located in a bottom portion of said thinned insulator layer, and said straight walled opening located in a top portion of said conductive region.