Abstract: In one embodiment, a semiconductor device includes a semiconductor substrate including device regions which extend in a first direction and are adjacent to one another in a second direction perpendicular to the first direction, and isolation regions disposed between the device regions. The device further includes a gate insulator disposed on a device region, a charge storing layer disposed on the gate insulator, and a hafnium containing film disposed on the charge storing layer, a width of the hafnium containing film in the second direction being larger than a width of at least one of a lower face of the charge storing layer, the gate insulator, and an upper face of the device region in the second direction.