Patent ID: 8212306
Filing Date: 2012-07-03
Classification: H01L

Abstract:
1. A semiconductor storage device comprising: a semiconductor substrate; a plurality of first insulating films formed on the semiconductor substrate with predetermined spacing therebetween; an element isolation region formed between the first insulating films in a first direction; a floating gate electrode comprising a first charge accumulation film formed on the first insulating film, a second charge accumulation film formed on the first charge accumulation film and having a width in a second direction orthogonal to the first direction smaller than the width of the first charge accumulation film, and a third charge accumulation film formed on the second charge accumulation film and having the width in the second direction larger than the width of the second charge accumulation film; a second insulating film formed on the second charge accumulation film and between the second charge accumulation film and the element isolation region; a third insulating film formed on the floating gate electrode and the element isolation region along the second direction; and a control gate electrode formed on the third insulating film.