Semiconductor device and electronic system the same

Abstract

A semiconductor device includes a lower level layer including a peripheral circuit; and an upper level layer provided on the lower level layer, the upper level layer including a vertically-extended memory cell string, wherein the lower level layer includes a first substrate; a device isolation layer defining a first active region of the first substrate; and a first gate structure including a first gate insulating pattern, a first conductive pattern, a first metal pattern, and a first capping pattern, which are sequentially stacked on the first active region, wherein the first conductive pattern comprises a doped semiconductor material, and the device isolation layer covers a first side surface of the first conductive pattern, and the first metal pattern includes a first body portion on the first conductive pattern.