SEMICONDUCTOR DEVICE AND DATA STORAGE SYSTEM INCLUDING THE SAME

A semiconductor device and a data storage system including the same are provided. The semiconductor device includes a first substrate structure including a substrate, a circuit element, and a first bonding metal layer, and a second substrate structure disposed directly on the first substrate structure. The second base structure includes a plate layer including a conductive material, a gate electrode stacked under the plate layer, a channel structure passing through the gate electrode and each including a channel layer, a separation region passing through the gate electrode and extending in the first direction and the second direction, and a source contact in the plate layer and disposed on the separation region. The source contact extends in a second direction. The second bonding metal layer of the second base structure is connected to the first bonding metal layer. The plate layer is in direct contact with the lateral side surface of the source contact and the upper end of the channel layer of each channel s