Method for forming a barrier metal film with conformal step coverage in a semiconductor integrated circuit

摘要

A method for forming a barrier metal film with conformal step coverage in a semiconductor integrated circuit includes forming a photoresist plug in a barrier metal lined contact or via hole. The barrier metal film has an overhang that narrows the opening to the contact or via hole. The barrier metal film is then etched using a fluorine based plasma etch process to remove the overhang. The photoresist plug is then removed using a oxygen based plasma etch process. The contact or via hole is then filled with tungsten to form a tungsten plug.