Patent ID: 7416942
Filing Date: 2008-08-26
Classification: C09G,H01L

Abstract:
1. A method for manufacturing a semiconductor device comprising: successively forming a first silicon film and a mask film above a semiconductor substrate through a gate insulating film; forming a plurality of trenches in the first silicon film and in the mask film to a depth to reach the semiconductor substrate; depositing a silicon oxide film to fill the plurality of trenches with the silicon oxide film; removing the mask film to expose the first silicon film existing between neighboring silicon oxide films buried in the plurality of trenches; selectively growing a second silicon film on the first silicon film; polishing the second silicon film using an alkaline slurry exhibiting a pH of 13 or less and containing abrasive grains and a cationic surfactant to planarize the second silicon film, thereby obtaining a floating gate electrode film comprising the first silicon film and the second silicon film; forming an interelectrode insulating film on the floating gate electrode film and on the silicon oxide film; and forming a control gate electrode film on the interelectrode insulating film.