20mΩcm>sup/sup

600V class superjunction (SJ) MOSFETs fabricated by deep-trench etching and epitaxial growth method are numerically and experimentally investigated. By applying a p-type ion implantation to its termination region, a breakdown voltage (VB) of the fabricated SJ-MOSFETs successfully increased by 150V. The fabricated SJ-MOSFET shows an extremely small specific on-resistance (RonA) of 19.8mOmegacm2at the breakdown voltage of 658V. This characteristic is lower than any other reported trench-filling type devices in the same voltage class