Patent ID: 6908847

Claim:
A method of manufacturing a semiconductor device, comprising the steps of: forming a first interlayer insulating film over a semiconductor substrate; forming a wiring trench in said first interlayer insulating film; forming a first barrier metal layer over side walls and a bottom surface of said wiring trench; forming a wiring layer by forming a first conductor layer over said first barrier metal layer so as to embed said wiring trench with said first conductor layer; forming a capping barrier metal film over a surface of said first conductor layer; forming a second interlayer insulating film over said first interlayer insulating film; forming a connecting hole in said second interlayer insulating film, said connecting hole being formed so as to expose at least a part of said capping barrier metal film; forming a second barrier metal layer over side walls and a bottom surface of said connecting hole; and forming a plug by forming a second conductor layer over said second barrier metal layer so as to embed said connecting hole with said second conductor layer, wherein said capping barrier metal film is removed in said step of forming said connecting hole, and is removed only at an overlapping portion of said connecting hole with said wiring trench in the step of forming said connecting hole, and wherein the method further comprises at least one of the steps of: heat treating, in an atmosphere containing hydrogen or ammonia, the surface of said first conductor layer exposed after the step of forming said connecting hole; generating plasma in an atmosphere containing either one of hydrogen or ammonia and a rare gas, and irradiating said surface of said first conductor layer that is exposed, with the plasma; and sputter etching with a rare gas, said surface of said first conductor layer exposed.