MOS device, having a metal-barrier metal-silicon gate structure, is produced by forming and processing a polysilicon gate electrode before forming a metal gate electrode

摘要

MOS device production, comprising forming and processing a polysilicon gate electrode (55a) before forming a metal gate electrode (73), is new. A MOS device production process comprises (a) successively forming a first insulating layer (53), a semiconductor layer and a second insulating layer on a semiconductor substrate (50); (b) selectively removing the semiconductor layer and the second insulating layer to form a first gate electrode (55a) and an associated cap insulation film; (c) forming a lightly doped second conductivity type impurity region (63) on the substrate (50) at each side of the first gate electrode (55a); (d) forming a sidewall spacer layer (65) on each side surface of the first gate electrode (55a) and associated cap insulation film; (e) forming a heavily doped second conductivity type impurity region (67) on the substrate (50) at each side of the sidewall spacer layers (65); (f) removing the cap insulation film to expose the top surface of the first gate electrode (55a); and (g) successively forming a barrier metal film (71), a second gate electrode (73) and an associated cap insulation film (75) on the first gate electrode (55a).