Integrated circuit device and electronic system including the same

Abstract

An integrated circuit device includes a plurality of conductive lines extending on a semiconductor substrate in a horizontal direction and overlapping each other in a vertical direction, a plurality of insulating layers alternating with the plurality of conductive lines and extending in the horizontal direction, and a channel structure extending through the plurality of conductive lines and the plurality of insulating layers. The channel structure includes a core insulating layer, a resistance change layer on a side wall and a bottom surface of the core insulating layer, a channel layer on an outside wall of the resistance change layer, and a pad pattern on a top surface of the core insulating layer. A topmost surface of the resistance change layer is in contact with the core insulating layer and is spaced apart from a bottommost surface of the pad pattern.