Patent ID: 6444566
Filing Date: 2002-09-03
Classification: H01L

Abstract:
A process for forming a borderless contact to a contacting area on a silicon surface, comprising the sequential steps of:depositing a buffer layer of silicon oxynitride over said silicon surface, including said contacting area; depositing a layer of silicon nitride on said layer of silicon oxynitride; depositing a dielectric layer on said layer of silicon nitride; patterning and etching said dielectric layer to form a via hole, having a first bottom, that extends as far as said layer of silicon nitride; selectively removing all silicon nitride from the first bottom of the via hole, thereby forming a second bottom; selectively removing all silicon oxynitride from the second bottom of the via hole, thereby exposing the contacting area; and filling the via hole with a metal plug that contacts the contacting area.