A method for fabricating a semiconductor device includes the steps of providing a semiconductor substrate; forming a tunnel dielectric on the semiconductor substrate; forming a floating gate on the tunnel dielectric; forming an insulation layer conformally disposed on the top surface and the sidewall surface of the floating gate; forming a control gate disposed on the insulation layer and the floating gate; and forming a spacer continuously distributed on the sidewall surfaces of the floating gate and the control gate, where the spacer overlaps portions of the top surface of the floating gate.