In one embodiment, the semiconductor memory device includes a semiconductor substrate having projecting portions, a tunnel insulation layer formed over at least one of the projecting semiconductor substrate portions, and a floating gate structure disposed over the tunnel insulation layer. An upper portion of the floating gate structure is wider than a lower portion of the floating gate structure, and the lower portion of the floating gate structure has a width less than a width of the tunnel insulating layer. First insulation layer portions are formed in the semiconductor substrate and project from the semiconductor substrate such that the floating gate structure is disposed between the projecting first insulation layer portions. A dielectric layer is formed over the first insulation layer portions and the floating gate structure, and a control gate is formed over the dielectric layer.