Semiconductor memory devices

A semiconductor memory device, comprising:

• a stack structure on a substrate, the stack structure including a ground select line and word lines stacked on the ground select line;
• and
• a vertical channel on the substrate and penetrating the stack structure,
• wherein the ground select line comprises:
• a first mask pattern;
• a first barrier pattern extending onto top and bottom surfaces of the first mask pattern from between the vertical channel and the first mask pattern;
• and
• a first metal pattern between the first mask pattern and the first barrier pattern.

A semiconductor memory device, comprising:

• a stack structure on a substrate, the stack structure including a ground select line and word lines stacked the ground select line;
• and
• a vertical channel on the substrate and penetrating the stack structure,
• wherein the ground select line comprises:
• a mask pattern;
• and
• a first metal pattern extending onto top and bottom surfaces of the mask pattern from between the vertical channel and the mask pattern,
• wherein each of the word lines comprises:
• a second metal pattern;
• and
• a barrier pattern extending onto top and bottom surfaces of the second metal pattern from between the vertical channel and the second metal pattern,
• wherein the first and second metal patterns have the same material.