A semiconductor device includes: a substrate including a cell area and an interface area; a gate electrode disposed in the substrate within the cell area and extending in a first direction; a plurality of bit lines intersecting the gate electrode and extending in a second direction intersecting the first direction, wherein the plurality of bit lines includes a plurality of first bit lines and a plurality of second bit lines alternately disposed in the first direction; edge spacers disposed within the interface area and contacting the plurality of second bit lines; and edge insulating layers disposed between the edge spacers and contacting the plurality of first bit lines, wherein at least a portion of each of the edge insulating layers is disposed within the interface area.