PURPOSE: To enhance the density of a semiconductor memory device by forming a reverse conductive type diffused layer to a semiconductor substrate under a dielectric film on the lower surface of a charge storage electrode, and electrically setting the diffused layer and a capacitor electrode provided on the dielectric film on the upper surface of a charge storage electrode to the same potential.

CONSTITUTION: An element separating region 22 and an element separating and diffused layer 23 are formed on a semiconductor substrate 21. After a gate insulating film 25 is then formed,a gate electrode 24 is formed. Then, N-type diffused layers 26, 36, 37 are formed by an ion implanting method, and the surface of the electrode 24 is coated with an insulating film. Then, the gate insulating film on the layer 37 is removed, and a contacting region 27 of a charge storage electrode and an N-type diffused layer 37 is formed. Subsequently, to form a charge storage electrode 28, a polycrystalline silicon film is accumulated, phosphorus is doped therewith to provide electric conductivity, a 2-layer insulating film 30 of an oxide film and a silicon nitride film is formed on the surface, and the desired pattern is formed. Then, the entirety is oxidized, etched, and a capacitor electrode 31 is then formed.