Patent ID: 6458689
Filing Date: 2002-10-01
Classification: H01L,Y10S

Abstract:
A method of forming an oxide dielectric Anti-Reflection Coating DARC coating for a contact or via opening; comprising the steps of:a) forming dielectric layer over a semiconductor structure; said dielectric layer is comprised of Hydrogen-Silsesquioxane spin-on-glass; b) chemical-mechanical polishing said dielectric layer whereby said chemical-mechanical polish creates microscratches in said dielectric layer; said microscratches have a depth form 300 to 500 Ã¥; c) forming an protective DARC layer composed of oxide over said dielectric layer; said protective DARC layer formed using a plasma enhanced chemical vapor deposition process; said protective DARC layer filling in said microscratches in said dielectric layer; said protective DARC layer has a thickness of between about 500 and 900 Ã¥; d) forming a photoresist layer over said protective DARC layer; said photoresist layer has a thickness of between about 6000 Ã¥ and 1 &mgr;m; said photoresist layer is a DUV photoresist; e) exposing, and developing said photoresist layer to create a first resist opening; said photoresist layer is exposed using I-line DUV light with a wavelength between 245 and 264 nm; f) etching said protective DARC layer and said dielectric layer through said first resist opening to form a first opening; said first opening is a dual damascene opening; said first resist opening having an open dimension between about 0.2 and 0.4 &mgr;m; g) removing said photoresist layer; h) forming a conductive layer over said protective DARC layer and filling said first opening; and i) chemical-mechanical polishing said conductive layer to remove said conductive layer from over said protective DARC layer and to form an interconnect filling said first opening; said protective DARC layer is used as a CMP stop whereby said protective layer prevents microscratches in said dielectric layer.