Semiconductor devices and data storage systems including the same

Abstract

A semiconductor device includes a first substrate, circuit elements, lower interconnection lines, a second substrate, gate electrodes stacked on the second substrate to be spaced apart from each other in a first direction and forming first and second stack structures, channel structures penetrating through the gate electrodes, and first and second contact plugs penetrating through the first and second stack structures, respectively, and connected to the gate electrodes. The first stack structure has first pad areas in which the gate electrodes extend further than upper gate electrodes, respectively, and are connected to the first contact plugs, respectively. The second stack structure has second pad areas in which the gate electrodes extend further than upper gate electrodes, respectively, and are connected to the second contact plugs, respectively. The first and second pad areas are offset in relation to each other so as not to overlap each other in the first direction.