Patent ID: 7037784
Filing Date: 2006-05-02
Classification: H01L

Abstract:
1. A method of forming a floating gate electrode of a flash memory device, comprising the steps of: forming a first silicon film for floating gate electrode and a pad nitride film on a semiconductor substrate, and patterning the pad nitride film, the first silicon film and a predetermined region of the semiconductor substrate to define trenches; forming buried insulation films in the defined trenches, and then performing a polishing process until the pad nitride film is exposed, thereby completing a process of forming isolation films; removing the patterned pad nitride film, and forming second silicon films for floating gate electrodes in the regions from which the pad nitride films are removed; and forming patterns for forming cylinder-shaped floating gate electrodes on the second silicon films, and performing an etch process on the second silicon films using the patterns as etch masks to form the cylinder-shaped floating gate electrode patterns on the first silicon films for floating gate electrodes.