A method for fabricating memory device includes the steps of: providing a substrate; forming a tunnel oxide layer on the substrate; forming a first gate layer on the tunnel oxide layer; forming a negative capacitance (NC) insulating layer on the first gate layer; and forming a second gate layer on the NC insulating layer. Preferably, the second gate layer further includes a work function metal layer on the NC insulating layer and a low resistance metal layer on the work function metal layer.