SEMICONDUCTOR DEVICE

A semiconductor device includes a substrate, a bit line extending on the substrate in a first direction, first and second active patterns on the bit line, a back-gate electrode between the first and second active patterns and extending across the bit line and in a second direction that is perpendicular to the first direction, a first word line extending in the second direction at one side of the first active pattern, a second word line extending in the second direction at the other side of the second active pattern, and a contact pattern connected to each of the first and second active patterns, wherein the contact pattern sequentially includes an epitaxial growth layer, a doped polysilicon layer, and a silicide layer.