Integrated circuit device and electronic system including the same

An integrated circuit device comprising:

• a semiconductor substrate including a cell region and a connection region adjacent to the cell region;
• a gate stack extending in a first direction and a second direction, including a plurality of conductive lines and a plurality of insulating layers, and having a stepped structure in the connection region, the first and second directions being parallel to a main surface of the semiconductor substrate and crossing each other, the plurality of conductive lines and the plurality of insulating layers being alternately stacked in a third direction that is perpendicular to the main surface of the semiconductor substrate;
• a channel structure in the cell region and extending through the gate stack in the third direction;
• and
• a plurality of contact plugs in the connection region and in contact with respective end portions of the plurality of conductive lines,
• wherein 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, a dielectric layer on an outside wall of the channel layer, and a pad pattern on a top surface of the core insulating layer, and
• 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.

An electronic system comprising:

• a main board;
• an integrated circuit device on the main board;
• and
• a controller on the main board and electrically connected to the integrated circuit device,
• wherein the 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,
• wherein 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, and
• 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.