Patent Number: 7,709,883

Title: Nonvolatile semiconductor memory device

Abstract: An object is to provide a nonvolatile semiconductor memory device which is excellent in a writing property and a charge retention property. In addition, another object is to provide a nonvolatile semiconductor memory device capable of reducing writing voltage. A nonvolatile semiconductor memory device includes a semiconductor layer or a semiconductor substrate including a channel formation region between a pair of impurity regions that are formed apart from each other, and a first insulating layer, a plurality of layers formed of different nitride compounds, a second insulating layer, and a control gate that are formed in a position which is over the semiconductor layer or the semiconductor substrate and overlaps with the channel formation region.

Inventors: Takano; Tamae (Atsugi, JP), Tokuda; Atsushi (Isehera, JP), Tajima; Ryota (Atsugi, JP), Yamazaki; Shunpei (Setagaya, JP)

Assignee: Semiconductor Energy Laboratory Co., Ltd

International Classification: H01L 29/788 (20060101)

Expiration Date: 5/04/12018