A process for producing a semiconductor memory device comprises the steps of: (a) forming a floating gate on a semiconductor substrate having a dielectric film; (b) forming a side wall spacer comprising an insulating film on a side wall of the floating gate; (c) forming a groove by etching the semiconductor substrate using the side wall spacer as a mask; and (d) forming a low concentration impurity layer from one side wall to a bottom surface of the groove by an oblique ion implantation to the semiconductor substrate thus resulting, and forming a high concentration impurity layer from the other side wall to the bottom surface of the groove by in inverse oblique ion implantation.