Dry etchback of interconnect contacts

摘要

A method and structure for a composite stud contact interface with a decreased contact resistance and improved reliability. A selective dry etch is used which comprises a fluorine containing gas. The contact resistance is reduced by partially dry-etching back the tungsten contact after or during the M1 RIE process. The recessed contact is then subsequently metalized during the M1 liner/plating process. The tungsten contact height is reduced after it has been fully formed.