SEMICONDUCTOR DEVICES AND DATA STORAGE SYSTEMS INCLUDING THE SAME

Semiconductor device includes a substrate, gate electrodes stacked and spaced apart from each other in a first direction perpendicular to an upper surface of the substrate, separation regions penetrating the gate electrodes, extending in a second direction perpendicular to the first direction, and spaced apart from each other in a third direction perpendicular to the first direction and the second direction, channel structures arranged in columns in the third direction and rows in the second direction and penetrating the gate electrodes between the separation regions, and bit lines extending in the third direction on the channel structures. The channel structures include a first group of channel structures repeatedly arranged and including three columns arranged with a first pitch and a second pitch smaller than the first pitch in order, and the bit lines are arranged with at least one pitch smaller than the second pitch in the second direction.