Vertical multi-RESURF MOSFETs exhibiting record low specific resistance

For the first time, experimental results are presented of vertical RESURF MOSFETs in which the alternating pn-junctions in the drift region are formed by a combination of a trench etch and vapor phase doping (VPD) process. Such a process allows very small pitch sizes, offering unprecedentedly low specific resistance. A reverse breakdown voltage of 165 V is obtained for devices with a 10 /spl mu/m drift region doped at 5/spl times/10/sup 15/ cm/sup -3/, with a corresponding specific resistance of 208 m/spl Omega//spl middot/mm/sup 2/ (V/sub g/=10 V). These are the first MOSFETs to break the 1D silicon limit below 200 V, with a specific resistance 30% below current state-of-the-art devices.