Patent ID: 7316955

Claim:
A method of fabricating a flash memory device, comprising the steps of: (a) forming tunnel oxide films, a first polysilicon layer and a sacrificial film on a semiconductor substrate defines an active region and a field region; (b) etching the sacrificial film, the first polysilicon layer, the tunnel oxide films and the semiconductor substrate of the field region to form trenches, and forming isolation films within the trenches; (c) removing the sacrificial film to expose upper sides of the isolation films; (d) forming insulating sidewalls on the sides of the exposed isolation films; (e) filling the portions from which the sacrificial film is removed with a second polysilicon layer; (f) removing the isolation films and the insulating sidewalls to expose the second polysilicon layer; and (g) sequentially forming an interlayer dielectric film and a control gate on the entire surface.