SEMICONDUCTOR MEMORY DEVICES

A semiconductor memory device including a transistor body extending in a first horizontal direction and including a first source/drain region, a single-crystal channel layer, and a second source/drain region sequentially arranged in the first horizontal direction, a gate electrode layer extending in a second horizontal direction orthogonal to the first horizontal direction and covering upper and lower surfaces of the single-crystal channel layer, a bit line connected to the first source/drain region, extending in a vertical direction, and having a first width in the second horizontal direction, a spacer covering upper and lower surfaces of the first source/drain region and having a second width greater than the first width, and a cell capacitor on a side opposite to the bit line with respect to the transistor body in the first horizontal direction and including lower and upper electrode layers and a capacitor dielectric layer therebetween may be provided.