SEMICONDUCTOR DEVICES AND DATA STORAGE SYSTEMS INCLUDING THE SAME

A semiconductor device includes a first semiconductor structure including circuit elements on a first substrate, a lower interconnection structure on the circuit elements, and a lower bonding structure on the lower interconnection structure; and a second semiconductor structure including a second substrate on the first semiconductor structure, separation insulating patterns separating the second substrate, and disposed to be spaced apart from each other, gate electrodes stacked to be spaced apart from each other, separation regions passing through the gate electrodes, and disposed to be spaced apart from each other, channel structures passing through the gate electrodes, an upper interconnection structure below the gate electrodes, and an upper bonding structure bonded to the lower bonding structure, wherein the separation insulating patterns include first separation insulating patterns on the separation regions, and second separation insulating patterns between the channel structures and passing through the second substrate.