In some embodiments, a semiconductor device is provided. The semiconductor device includes a semiconductor substrate having a first semiconductor material layer separated from a second semiconductor material layer by an insulating layer. A source region and a drain region are disposed in the first semiconductor material layer and spaced apart. A gate electrode is disposed over the first semiconductor material layer between the source region and the drain region. A first doped region having a first doping type is disposed in the second semiconductor material layer, where the gate electrode directly overlies the first doped region. A second doped region having a second doping type different than the first doping type is disposed in the second semiconductor material layer, where the second doped region extends beneath the first doped region and contacts opposing sides of the first doped region.