Patent attributes
A semiconductor device includes a substrate, a first gate structure including first gate electrodes that are vertically stacked on the substrate, first channels penetrating the first gate structure to contact the substrate, a second gate structure including a channel connection layer on the first gate structure and second gate electrodes on the channel connection layer, second channels penetrating the second gate structure to contact the first channels, respectively, and separation regions penetrating the second gate structure and the first gate structure and extending in a first direction. The second gate electrodes are vertically stacked on the channel connection layer. The channel connection layer is between the separation regions and has at least one sidewall that is spaced apart from sidewalls of the separation regions.