SEMICONDUCTOR DEVICE AND ELECTRONIC SYSTEM INCLUDING THE SAME

A semiconductor device includes a first semiconductor structure including a first substrate and circuit devices; and a second semiconductor structure including a second substrate on the first semiconductor structure and having a first region and a second region, gate electrodes in the first region and stacked in a first direction, and extending in the second region by different lengths in a second direction, channel structures extending by penetrating through the gate electrodes, separation regions penetrating through the gate electrodes, extending in the second direction, spaced apart from each other in a third direction, and defining a center block region and an edge block region, and substrate insulating layers in the second substrate between the separation regions in the second region. A width of the substrate insulating layers in the third direction is greater in the edge block region than in the center block region.