摘要 |
A semiconductor device includes a semiconductor region, a tunnel insulating film formed on a surface of the semiconductor region, a charge-storage insulating film formed on a surface of the tunnel insulating film and containing silicon and nitrogen, a block insulating film formed on a surface of the charge-storage insulating film, and a control gate electrode formed on a surface of the block insulating film, wherein the tunnel insulating film has a first insulating film formed on the surface of the semiconductor region and containing silicon and oxygen, a second insulating film formed on a surface of the first insulating film, and a third insulating film formed on a surface of the second insulating film and containing silicon and oxygen, and a charge trap state in the second insulating film has a lower density than that in the charge-storage insulating film. |