Provided are a semiconductor device and a method of manufacturing the semiconductor device. The semiconductor device includes a charge storage pattern formed on a substrate; a dielectric pattern formed on the charge storage pattern; a first conductive pattern including silicon doped with a first impurity of a first concentration, the first conductive pattern being disposed on the dielectric pattern; and a second conductive pattern including metal silicide doped with a second impurity of a second concentration, the second conductive pattern being disposed on the first conductive pattern. The first concentration may be higher than the second concentration.