Semiconductor devices and data storage systems including the same

Abstract

A semiconductor device includes a lower structure, stack structure including gate electrodes stacked and spaced apart from each other on a first region of the lower structure and extending in a staircase shape on a second region of the lower structure, and interlayer insulating layers alternately stacked with the gate electrodes, channel structures penetrating through the gate electrodes on the first region, and isolation structures penetrating through the gate electrodes spaced apart from each other. Each channel structure a channel bent portion between first and second channel structures. Each isolation structure includes a first isolation bent portion between first and second isolation structures and a second isolation bent portion between second and third isolation structures. A width of an upper surface of the second isolation structure is narrower than a width of a lower surface of the third isolation structure.