Three-dimensional semiconductor memory device and electronic system including the same

Abstract

A three-dimensional semiconductor devices including a substrate, a stack structure including gate electrodes on the substrate and string selection electrodes spaced apart from each other on the gate electrodes, a first separation structure running in a first direction across the stack structure and being between the string selection electrodes, vertical channel structures penetrating the stack structure, and bit lines connected to the vertical channel structures and extending in a second direction may be provided. A first subset of the vertical channel structures is connected in common to one of the bit lines. The vertical channel structures of the first subset may be adjacent to each other in the second direction across the first separation structure. Each of the string selection electrodes may surround each of the vertical channel structures of the first subset.