Semiconductor memory device and method of manufacturing the same

A semiconductor device and a method of manufacturing the same are provided. The semiconductor device includes insulation layers and gate electrodes alternately stacked on a substrate, a vertical channel vertically passing through the insulation layers and the gate electrodes, and a threshold voltage controlling insulation layer, a tunnel insulation layer and a charge storage layer disposed between the vertical channel and the gate electrodes, wherein the threshold voltage controlling insulation layer is disposed between the charge storage layer and the vertical channel and including a material configured to suppress an inversion layer from being formed in the vertical channel.