A semiconductor device includes a first substrate including at least one first well region and first impurity regions on portions of the substrate and a bias voltage plate on a surface of the substrate. A semiconductor device may be of a three dimensional stack structure, and in example embodiments, the semiconductor device may further include a through contact plug substantially perpendicularly penetrating at least one substrate and at least one bias voltage plate. Therefore, a design margin of a semiconductor device may be enhanced and a bias voltage may be provided reliably.