CVD process for copper interconnection

Abstract

A complete optimisation of a Cu-MOCVD process was performed in an industrial cluster tool fitted for 200 mm silicon wafers. Blanket Cu layer deposition rate over 200 nm/min was achieved using liquid Cu(hfac)vtms precursor with a direct liquid injection system. The major issues concerning the process integration for fabrication of Cu interconnects capped by a thin TiN-MOCVD barrier layer in a dual damascene architecture were successfully addressed. Void free filling of aggressive line and via structures was performed at high deposition rate. Good adhesion between the Cu metallisation and the TiN barrier required for Cu Chemical Mechanical Polishing was obtained using a post Copper deposition thermal treatment.