US Patent 9214569 Memory device

According to example embodiments, a memory device includes a substrate, a channel region on the substrate, a plurality of gate electrode layers stacked on each other on the substrate, and a plurality of contact plugs. The gate electrode layers are adjacent to the channel region and extend in one direction to define a pad region. The gate electrode layers include first and second gate electrode layers. The contact plugs are connected to the gate electrode layers in the pad region. At least one of the contact plugs is electrically insulated from the from the first gate electrode layer and electrically connected to the second gate electrode layer by penetrating through the first gate electrode layer.