Barrier metal free copper damascene interconnection technology using atmospheric copper reflow and nitrogen doping in SiOF film

This paper describes a barrier metal free copper damascene interconnection technology using atmospheric copper reflow and nitrogen doping in SiOF films for improvement of RC delay. Formation of a thin barrier layer for copper on the surface of SiOF film was achieved by NH/sub 3/ plasma treatment. Barrier metal free copper damascene interconnects having a resistivity of 1.8/spl plusmn/0.03 /spl mu//spl Omega//spl middot/cm, lower than that of Cu/TiN structures, were successfully fabricated without peeling-off failures. By use of this structure, a 25% reduction for Tpd in a 0.18 /spl mu/m CMOS technology, compared with that of the Cu/TiN structure, was confirmed by SPICE simulation.