Patent ID: 6741501
Filing Date: 2004-05-25
Classification: G11C,H01L

Abstract:
A nonvolatile semiconductor memory device having a plurality of memory cells, wherein each of said plurality of memory cells comprises:(a) a first semiconductor region in a semiconductor substrate; (b) a second semiconductor region in said first semiconductor region; (c) a third semiconductor region in said first semiconductor region; (d) a first insulator film disposed on a part of said first semiconductor region which is between said second semiconductor region and said third semiconductor region and disposed close to said second semiconductor region; (e) a second insulator film disposed on said first semiconductor region which is between said first insulator film and said third semiconductor region; (f) a first gate disposed on said first insulator film; (g) a third insulator film disposed on said first gate; (h) a second gate disposed on said third insulator film; and (i) a third gate disposed on said second insulator film, wherein the thickness of said first insulator film is greater than that of said second insulator film.