A semiconductor structure includes a symmetric metal-oxide-semiconductor (MOS) transistor comprising a first and a second asymmetric MOS transistor. The first asymmetric MOS transistor includes a first gate electrode, and a first source and a first drain adjacent the first gate electrode. The second asymmetric MOS transistor includes a second gate electrode, and a second source and a second drain adjacent the second gate electrode. The first gate electrode is connected to the second gate electrode, wherein only one of the first source and the first drain is connected to only one of the respective second source and the second drain.