Complementary MOS field effect transistor with tunnel effect means

Claim 1

A complementary MOS field effect transistor having a dual gate structure, comprising: a semiconductor substrate; an n well and a p well formed in said semiconductor substrate; an n channel MOSFET formed in said p well and having a first gate electrode; and a p channel MOSFET formed in said n well and having a second gate electrode, wherein said first gate electrode includes a first silicon film which is formed on said p well with a gate insulating film therebetween and to which impurities of a first conductivity type have been implanted, a first silicon oxide film formed on said first silicon film, and a first conductive film of metal or metal silicide formed on said first silicon oxide film, said second gate electrode includes a second silicon film which is formed on said n well with a gate insulating film therebetween and to which impurities of a second conductivity type have been implanted, a second silicon oxide film formed on said second silicon film, and a second conductive film of metal or metal silicide formed on said second silicon oxide film, said first silicon oxide film has a sufficiently small thickness so that a potential can be transmitted from said first conductive film to said first silicon film by means of a tunnel effect, and said second silicon oxide film has a sufficiently small thickness so that a potential can be transmitted from said second conductive film to said second silicon film by means of a tunnel effect, wherein each of said first and second silicon oxide films has a thickness of at most 30 Å.