Semiconductor memory device

A semiconductor memory device, comprising:

• a cell array portion disposed on a peripheral circuit portion, wherein:
• the cell array portion includes:
• first conductive lines, which extend in a first direction and are spaced apart from each other in a second direction crossing the first direction;
• second conductive lines, which are provided on the first conductive lines and extend in the second direction and are spaced apart from each other in the first direction;
• and
• memory cells respectively disposed between the first conductive lines and the second conductive lines,
• the peripheral circuit portion includes:
• first selection transistors, which are disposed on a substrate and are connected to the first conductive lines;
• and
• second selection transistors, which are disposed on the substrate and are connected to the second conductive lines,
• each of the first selection transistors has a first gate width, and
• each of the second selection transistors has a second gate width that is different from the first gate width.

A semiconductor memory device, comprising:

• first conductive lines provided on a substrate and extending in a first direction;
• second conductive lines provided on the first conductive lines and extending in a second direction crossing the first direction;
• third conductive lines provided on the second conductive lines and extending in the first direction;
• fourth conductive lines provided on the third conductive lines and extending in the second direction;
• and
• first, second, third, and fourth selection regions, which are provided on the substrate and are connected to the first to fourth conductive lines, respectively, wherein:
• the first selection region and the third selection region are spaced apart from each other in the first direction,
• the second selection region and the fourth selection region are spaced apart from each other in the second direction and have a shape elongated in the first direction, and
• an area of the first selection region is different from an area of the third selection region, or an area of the second selection region is different from an area of the fourth selection region.