A semiconductor device is provided. The semiconductor device includes a substrate, an electrode stack disposed on the substrate, the electrode stack including an interlayer insulation layer and a gate electrode structure that are alternately stacked in a direction perpendicular to the substrate, a trench penetrating the electrode stack to expose sidewall surfaces of the interlayer insulation layer and the gate electrode structure, a gate dielectric layer disposed along a sidewall surface of the trench, the gate dielectric layer including a ferroelectric portion and a non-ferroelectric portion, and a channel layer disposed to adjacent to the gate dielectric layer. The ferroelectric portion is in contact with the gate electrode structure, and the non-ferroelectric portion is in contact with the interlayer insulation layer.