Abstract: A MOS integrated circuit device fabricated utilizing high energy, high current implanting of ions through a layer of oxide to form heavily doped source and drain regions which are self-aligned with a polysilicon gate. A thick portion of the oxide layer adjacent to the polysilicon gate prevents heavy doping in the substrate next to the gate. The oxide layer is removed and a lightly doped drain (LDD) implant forms an LDD region which is self-aligned with the gate. Using this method the source/drain and LDD implants are performed using only a single mask and etch operation, rather than two mask and etch operations which are necessary using a conventional process.