Patent ID: 6033963
Filing Date: 2000-03-07
Classification: H01L

Abstract:
A method for forming a metal gate using a replacement gate process with a selective tungsten deposition comprising the steps of:a. forming a dummy gate oxide layer on a substrate structure;b. forming a dummy gate electrode layer on said dummy gate oxide layer; said dummy gate electrode layer being composed of polysilicon;c. patterning said dummy gate electrode layer and said dummy gate oxide layer to form a dummy gate having sidewalls;d. implanting impurity ions into said substrate structure using said dummy gate as an implant mask;e. forming spacers on said sidewalls of said dummy gate; said spacers being composed of silicon dioxide or silicon oxynitride;f. implanting impurity ions into said substrate structure using said dummy gate and said spacers as an implant mask and performing a rapid thermal anneal to form source and drain regions;g. forming a selective tungsten layer on said dummy gate electrode and on said source and drain regions;h. forming a blanket dielectric layer over said dummy gate and said substrate structure;i. planarizing said blanket dielectric layer using a chemical mechanical polishing process and stopping on said tungsten layer;j. removing said tungsten layer overlying said dummy gate and said dummy gate; thereby forming a gate opening;k. forming a gate oxide layer on said substrate structure in said gate opening;l. forming a gate electrode layer over said gate oxide layer; said gate electrode layer being composed of a metal selected from the group comprising titanium, tungsten, or aluminum; andm. planarizing said gate electrode layer stopping on said blanket dielectric layer thereby forming a metal gate.