Patent ID: 6372576
Filing Date: 2002-04-16
Classification: H01L

Abstract:
A method of manufacturing a floating gate in a flash memory device, comprising the steps of:providing a semiconductor substrate that comprises a first portion that is covered with a field oxide film and a second portion that is not covered with the field oxide film; forming a tunnel oxide film on the second portion of the semiconductor substrate that is not covered with the field oxide film; forming a polysilicon film on the tunnel oxide film and the field oxide film; forming a first PSG film on the polysilicon film; patterning the first PSG film to form a sidewall of the first PSG film; forming a second PSG film on an entire structure; blanket-etching the second PSG film, thus forming a spacer at the sidewall of the first PSG film; etching said polysilicon film and said tunnel oxide film by means of etching process, using said first PSG film and the spacer as a mask; and removing said first PSG film and the spacer.