A transmission gate structure includes first and second PMOS transistors in a first active area and first and second NMOS transistors in a second active area. The first and second PMOS transistors include first and second gate structure, the first NMOS transistor includes a third gate structure coupled to the second gate structure, and the second NMOS transistor includes a fourth gate structure coupled to the first gate structure. A first metal zero segment overlies the first active area, a second metal zero segment is offset from the first metal zero segment by an offset distance, a third metal zero segment is offset from the second metal zero segment by the offset distance, and a fourth metal zero segment is offset from the third metal zero segment by the offset distance and overlies the second active area.