Patent ID: 7968933

Claim:
A nonvolatile semiconductor memory device comprising: a tunnel insulating film which is formed on a surface of a semiconductor substrate; a floating gate electrode which is formed on the tunnel insulating film, at least an interface region which the floating gate electrode defines on a side opposite to that of the substrate, being made of n-type Si or metal-based conductive material; a first insulating-material film which is formed on the floating gate electrode and which has a first barrier height; a second insulating-material film which is formed on the first insulating-material film and which is made of high-permittivity material, the high-permittivity material being oxide, nitride or oxynitride containing at least one element selected from the group consisting of Al, Hf, La, Y, Ce, Ti, Zr, and Ta, the second insulating-material film having a second barrier height smaller than that of the first insulating-material film; a third insulating-material film which is formed on the second insulating-material film and which has a third barrier height greater than that of the second insulating-material film; a control gate electrode which is formed on the third insulating-material film, at least an interface region which the control gate electrode defines on a side of the third insulating-material film, being made of a p-type semiconductor containing at least one of Si and Ge; and an n-type source/drain region formed in the surface of the semiconductor substrate.