Semiconductor memory device and method of fabricating the same

A semiconductor memory device comprising:

• a plurality of stack gate structures disposed on a substrate, each of the stack gate structures including insulating layers and gate electrodes that are alternately and repeatedly stacked on the substrate, and the stack gate structures being spaced apart from each other in a first direction;
• a plurality of vertical channel structures penetrating each of the stack gate structures;
• a source plug line disposed between the plurality of stack gate structures, the source plug line including a conductive material and extending in a second direction intersecting the first direction;
• and
• a common source region being in contact with the source plug line and disposed in the substrate,
• wherein the common source region comprises a first dopant region and a second dopant region that are alternately formed along the second direction,
• wherein the first dopant region has a first height and the second dopant region has a second height, and
• wherein the first height is greater than the second height.

A semiconductor memory device comprising:

• a plurality of vertical channel structures disposed on a substrate and extending in a direction vertical to the substrate;
• a plurality of stack gate structures surrounding the vertical channel structures and including gate electrodes stacked in the direction vertical to the substrate, the stack gate structures being spaced apart from each other in a first direction parallel to the substrate;
• and
• a common source region formed in the substrate and including a plurality of protruding regions that are formed along a second direction intersecting the first direction between the stack gate structures,
• wherein each of the protruding regions has a first width in the second direction, and
• wherein the protruding regions are spaced apart from each other by a first distance greater than the first width.