A method is provided for fabricating a semiconductor on insulator (SOI) device. The method includes, in one embodiment, providing a monocrystalline silicon substrate having a monocrystalline silicon layer overlying the substrate and separated therefrom by a dielectric layer. A gate electrode material is deposited and patterned to form a gate electrode and a spacer. Impurity determining dopant ions are implanted into the monocrystalline silicon layer using the gate electrode as an ion implant mask to form spaced apart source and drain regions in the monocrystalline silicon layer and into the monocrystalline silicon substrate using the spacer as an ion implant mask to form spaced apart device regions in the monocrystalline substrate. Electrical contacts are then formed that contact the spaced apart device regions.