Patent ID: 7125769

Claim:
A method of fabricating a flash memory device, comprising the steps of: forming a screen oxide film and a pad nitride film on a semiconductor substrate; etching the pad nitride film, the screen oxide film and the semiconductor substrate to form trenches; forming sidewall oxide films on the surface of the semiconductor substrate in which the trenches are formed, and regrowing the screen oxide film in such a way to have a predetermined thickness; reducing a thickness of the sidewall oxide films; forming a liner nitride film on the entire surface including the trenches; forming element isolation films within the trenches; removing the liner nitride film and the pad nitride film to expose the element isolation films that are projected upwardly from the semiconductor substrate; etching the entire surface so that the screen oxide film is removed, thereby reducing the width of the element isolation films, which are exposed due to the removal of the pad nitride film; and forming floating gates with tunnel dielectric films being interspersed between neighboring element isolation films.