Patent ID: 6258678
Filing Date: 2001-07-10
Classification: H01L

Abstract:
A method of forming a self-aligned contact, (SAC), opening, in a composite insulator layer, exposing an active device region in a semiconductor substrate, comprising the steps of:forming gate structures on an underlying gate insulator layer;forming lightly doped source/drain regions in areas of said semiconductor substrate not covered by said gate structures;performing an anneal cycle resulting in formation of a thin silicon oxide layer on the sides of a polysilicon component of said gate structures;forming insulator spacers on the sides of said gate structures;forming heavily doped source/drain regions in areas of said semiconductor substrate not covered by said gate structures or by said insulator spacers;forming said composite insulator layer on said active device region, and the top surface of said gate structures;performing a dry etching procedure to selectively define a first portion of said SAC opening, in a third insulator layer, of said composite insulator layer, with said dry etching procedure forming polymer material on the top surface of said second insulator layer, and with polymer material allowing said dry etching procedure to terminate at said top surface of said second insulator layer;performing a first wet etch procedure, to selectively remove polymer material from the top surface of said second insulator, of said composite insulator layer;selectively removing the portion of said second insulator layer, exposed in said first portion of said SAC opening, creating said SAC opening;performing a second wet etch procedure to remove portions of a first insulator layer, exposed in said SAC opening; exposed the top surface of said active device region, located between said gate structures; andforming a self-aligned contact structure, in said SAC opening.