Patent ID: 6093632
Filing Date: 2000-07-25
Classification: H01L

Abstract:
A method of fabricating a metal structure, on a semiconductor substrate, with the metal structure featuring a wide, metal shape, on underlying, narrow metal shape, comprising the steps of:providing a first metal interconnect structure, located in an opening in a first insulator layer;depositing a first silicon nitride layer, a second insulator layer, and a second silicon nitride layer, on the top surface of said first metal interconnect structure, and on the top surface of said first insulator layer;patterning of said second silicon nitride layer, to form silicon nitride islands, with narrow spaces between said silicon nitride islands, exposing a portion of the top surface of underlying, said second insulator layer;depositing a third insulator layer;forming a photoresist shape, on said third insulator layer, featuring a wide opening in said photoresist shape, exposing a portion of the top surface of said third insulator layer;performing a selective, first dry etching procedure, using said wide opening, in said photoresist shape as a mask, to create a wide diameter opening, in said third insulator layer, exposing a portion of said silicon nitride islands, and exposing a narrow space, located between said silicon nitride islands, then continuing said selective, first dry etching procedure, to create a narrow diameter opening in said second insulator layer, using portions of said silicon nitride islands, exposed in said wide diameter opening, as a mask, to create a narrow diameter opening in said second insulator layer, exposing a portion of said first silicon nitride layer, located at the bottom of said narrow diameter opening;performing a selective, second dry etching procedure, to remove portion of said first silicon nitride layer, located at the bottom of said narrow diameter opening, exposing a portion of the top surface of said first metal interconnect structure, and removing portions of said silicon nitride islands, exposed in said wide diameter opening; andforming said metal structure, comprised of said wide metal shape, located in said wide diameter opening, and comprised of said narrow metal, located in said narrow diameter opening, with said narrow metal shape, overlying and contacting, the portion of said first metal interconnect structure, exposed at the bottom of said narrow diameter opening.