Patent ID: 7189618

Claim:
A method of manufacturing a transistor of a semiconductor device, the method comprising: forming a tunnel oxide film on a semiconductor substrate; stacking a floating gate, a dielectric film, a control gate and a capping film on the tunnel oxide film and patterning the floating gate, the dielectric film, the control gate and the capping film to form a stack type gate, wherein the floating gate is partially patterned so that a predetermined thickness remains; forming first spacers on sidewalls of the capping film, the control gate, the dielectric film and the floating gate; etching the remaining floating gate using the capping film and the first spacer as an etch mask; growing an oxide film on the tunnel oxide film and at the side of the floating gate to form a thermal oxide film that is infiltrated into the bottom of the floating gate at a given depth; removing the tunnel oxide film at the bottom of the thermal oxide film and the thermal oxide film; forming gaps of a predetermined shape between a gate oxide film formed at the side and bottom of the floating gate and a gate oxide film formed on the semiconductor substrate, while growing a gate oxide film at the side and bottom of the exposed floating gate and on the semiconductor substrate; depositing a nitride film on the semiconductor substrate on which the gate oxide films are grown to form floating nitride films to bury the gaps; and forming second spacers on sidewalls of the first spacers, the gate oxide film and the floating nitride film.