A nonvolatile semiconductor memory device includes a tunnel insulating
film, a floating gate electrode, an inter-electrode insulating film, and
a control gate electrode. The tunnel insulating film is formed on a
selected part of a surface of a semiconductor substrate. The floating
gate electrode is formed on the tunnel insulating film. At least that
interface region of the floating gate electrode, which is opposite to the
substrate, is made of n-type Si or metal-based conductive material. The
inter-electrode insulating film is formed on the floating gate electrode
and made of high-permittivity material. The control gate electrode is
formed on the inter-electrode insulating film. At least that interface
region of the control gate electrode, which is on the side of the
inter-electrode insulating film, is made of a p-type semiconductor layer
containing at least one of Si and Ge.