Patent ID: 7214580
Filing Date: 2007-05-08
Classification: H01L

Abstract:
1. A method of manufacturing a semiconductor device comprising: forming a lower gate insulating film on a semiconductor substrate; forming a floating gate material film on the lower gate insulating film; patterning the floating gate material film, the lower gate insulating film and the semiconductor substrate to form first and second pattern regions partitioned by a trench; forming a lower insulating film having a first depression in the trench; forming an upper insulating film on the lower insulating film to fill the first depression with the upper insulating film; etching the upper insulating film at an etching rate higher than an etching rate of the lower insulating film to form a second depression corresponding to the first depression in the lower insulating film; forming an upper gate insulating film on the patterned floating gate material films included in the first and second pattern regions; and forming a control gate material film on the upper gate insulating film and in the second depression.