According to example embodiments of inventive concepts, a semiconductor device includes: a substrate, and a stacked structure including interlayer insulating layers and gate electrodes alternately stacked on the substrate. The stacked structure defines a through-hole over the substrate. The gate electrodes each include a first portion between the through-hole and a second portion of the gate electrodes. A channel pattern may be in the through-hole. A tunneling layer may surround the channel pattern. A charge trap layer may surround the tunneling layer, and protective patterns may surround the first portions of the gate electrodes. The protective patterns may be between the first portions of the gate electrodes and the charge trap layer.