Semiconductor memory devices and methods for fabricating the same

A semiconductor memory device comprising:

• a conductive line extending in a first direction, on a substrate;
• an interlayer insulation film that includes a cell trench extending in a second direction intersecting the first direction, on the substrate;
• a first gate electrode and a second gate electrode that are spaced apart from each other in the first direction and each extend in the second direction, inside the cell trench;
• a separation trench that overlaps the conductive line and extends in the second direction to separate the first gate electrode and the second gate electrode;
• a channel layer that extends along the first gate electrode and the second gate electrode and through the separation trench to electrically connect to the conductive line;
• and
• a gate insulation layer interposed between the first gate electrode and the channel layer, and between the second gate electrode and the channel layer.

A semiconductor memory device comprising:

• a bit line extending in a first direction on a substrate;
• a first interlayer insulation film that includes a cell trench extending in a second direction intersecting the first direction, on the substrate;
• a first word line and a second word line that are spaced apart from each other in the first direction and each extend in the second direction, inside the cell trench;
• a channel layer that is inside the cell trench, is electrically connected to the bit line, and includes an oxide semiconductor material, on the first word line and the second word line;
• a gate insulation layer interposed between the first word line and the channel layer, and between the second word line and the channel layer;
• a first capacitor structure electrically connected to a first end of the channel layer adjacent to the first word line;
• and
• a second capacitor structure electrically connected to an opposite, second end of the channel layer adjacent to the second word line.