Patent ID: 7816244

Claim:
A method for fabricating a semiconductor device, the method comprising the steps of: forming an n-transistor including a first gate insulating film and a first gate electrode made of silicon and a p-transistor including a second gate insulating film and a second gate electrode made of silicon, on a semiconductor region; selectively forming a first metal film and a second metal film on the first gate electrode and the second gate electrode, respectively, such that the first metal film and the second metal film have different areas; and performing a heat treatment on the first gate electrode and the second gate electrode on which the first metal film and the second metal film have been formed, thereby fully siliciding each of the first gate electrode and the second gate electrode, wherein in the step of selectively forming the first and second metal films, if a metal constituting the second metal film has a work function larger than a Fermi level in potential energy of electrons of silicon, the second metal film is formed to have an area larger than that of the first metal film whereas if the metal constituting the second metal film has a work function smaller than the Fermi level of silicon, the second metal film is formed to have an area smaller than that of the first metal film.