Patent ID: 8952439
Filing Date: 2015-02-10
Classification: H01L

Abstract:
1. A nonvolatile semiconductor storage device, comprising: a semiconductor substrate having an element isolation groove; a plurality of memory cells, each including a first gate electrode having a charge storage layer, an interelectrode insulating film, and a control electrode, the first gate electrode being on the semiconductor substrate via a tunnel insulating film, and the interelectrode insulating film being between the charge storage layer and the control electrode; and an insulating film in the element isolation groove, the insulating film having an upper surface that is lower than an upper surface of the semiconductor substrate, wherein the interelectrode insulating film and the control electrode of the first gate electrode are over the insulating film, and the interelectrode insulating film includes a first portion directly on the insulating film and a second portion over the charge storage layer that is separated from the charge storage layer by a cavity.