Patent ID: 6103455
Filing Date: 2000-08-15
Classification: H01L

Abstract:
A method of forming a deep contact plug comprising the steps of:a) forming a dielectric layer over a semiconductor structure; said dielectric layer having a top surface; said semiconductor structure is a semiconductor wafer; said semiconductor structure having a doped region therein;b) forming a hard mask layer over said dielectric layer;c) said hard mask layer composed of a material selected from the group consisting of polysilicon, and silicon nitride;d) forming a contact photoresist layer having a contact photoresist opening over said doped region;e) etching said hard mask layer through said contact photoresist opening to form a contact hard mask opening through said hard mask layer exposing said dielectric layer;f) etching said dielectric layer using said contact photoresist layer and said hard mask layer as an etch mask forming a contact hole in said dielectric layer exposing said semiconductor structure;g) removing said contact photoresist layer;h) forming a metal layer over said hard mask layer and filling said contact hole;i) etching back using a plasma etch process said metal layer forming a plug filling said contact hole; and said plug having a plug top surface; said plug top surface is above said top surface of said dielectric layer; andj) removing said hard mask layer.