Patent 7968947 was granted and assigned to NEC Corporation on June, 2011 by the United States Patent and Trademark Office.
This invention provides a semiconductor device that can prevent a deviation of work function by adopting a gate electrode having a uniform composition and exhibits excellent operating characteristics by virtue of effective control of a Vth. The semiconductor device is characterized by comprising a PMOS transistor, an NMOS transistor, a gate insulating film comprising an Hf-containing insulating film with high permittivity, a line electrode comprising a silicide region (A) and a silicide region (B), one of the silicide regions (A) and (B) comprising a silicide (a) of a metal M, which serves as a diffusing species in a silicidation reaction, the other silicide region comprising a silicide layer (C) in contact with a gate insulating film, the silicide layer (C) comprising a silicide (b) of a metal M, which has a smaller atom composition ratio of the metal M than the silicide (a), and a dopant which can substantially prevent diffusion of the metal M in the silicide (b).