A transistor includes: a gate structure disposed on a substrate, and including a gate insulation layer and a gate electrode; a first impurity region disposed at an upper portion of a substrate and adjacent to a first sidewall of the gate structure; a second impurity region disposed at an upper portion of the substrate and adjacent to a second sidewall opposite to the first sidewall of the gate structure; and a first threshold voltage controlling line spaced apart from the substrate, wherein the first threshold voltage controlling line faces at least a portion of the first impurity region, wherein the first threshold voltage controlling line includes a conductive material, and wherein the first threshold voltage controlling line extends in a direction that crosses a direction in which the first impurity region extends.