Patent ID: 6136695
Filing Date: 2000-10-24
Classification: H01L

Abstract:
A method for forming a self aligned contact, comprising the steps of:a. providing a semiconductor structure, having a conductive structure thereon and having a contact area adjacent to said conductive structure;b. forming a dielectric layer over said semiconductor structure and said conductive structure;c. forming a top hard mask layer over said dielectric layer;d. forming a contact opening in said top hard mask and said dielectric layer over said contact area; said contact opening opening having sidewalls;e. forming a first lining dielectric layer on said sidewalls of said contact opening, on said top hard mask layer and on said contact area;f. forming a second lining dielectric layer on said first lining dielectric layer;g. forming a third lining dielectric layer over said second lining dielectric layer wherein said first and third lining dielectric layer material is different than said second lining dielectric layer material;h. anisotropically etching said third lining dielectric layer to form a second contact opening in said third lining dielectric layer over said contact area and to form spacers over said sidewalls of said contact opening;i. anisotropically etching said second lining dielectric layer and said first lining dielectric layer; thereby exposing said contact area of said semiconductor structure and said top hard mask layer;j. removing said spacers; andk. forming a contact layer composed of polysilicon on said second lining dielectric layer, said top hard mask layer, and said contact area of said semiconductor structure.