Semiconductor memory devices

A semiconductor memory device including a substrate; a semiconductor pattern extending in a first horizontal direction on the substrate; bit lines extending in a second horizontal direction on the substrate perpendicular to the first horizontal direction, the bit lines being at a first end of the semiconductor pattern; word lines extending in a vertical direction on the substrate at a side of the semiconductor pattern; a capacitor structure on a second end of the semiconductor pattern opposite to the first end in the first horizontal direction, the capacitor structure including a lower electrode connected to the semiconductor pattern, an upper electrode spaced apart from the lower electrode, and a capacitor dielectric layer between the lower electrode and the upper electrode; and a capacitor contact layer between the second end of the semiconductor pattern and the lower electrode and including a pair of convex surfaces in contact with the semiconductor pattern.