Semiconductor device having upper layer portion of semiconductor substrate divided into a plurality of active areas

摘要

A semiconductor memory device includes: a semiconductor substrate; a plurality of element isolation insulators disposed in parts of an upper layer portion of the semiconductor substrate and dividing the upper layer portion into a plurality of active areas extended in one direction; tunnel insulating films provided on the active areas: charge storage members provided on the tunnel insulating films; and control gate electrodes provided on the charge storage members. A width of a middle portion of one of the active areas in the up-to-down direction being smaller than a width of a portion of the active areas upper of the middle portion and a width of a portion of the active areas below the middle portion.