Ultra low on-resistance Super 3D MOSFET under 300 V breakdown voltage

For the range of under 300 V breakdown voltage, we have already proposed a new structural power MOSFET that we call Super 3D MOSFET. At 70 V breakdown voltage, the simulated total specific on-resistance was 19 mohm.mm/sup 2/, and below the R/sub on/ Si limit. In this work, we present the structural design for the breakdown voltage, taking the electric field concentration into consideration at its 3-dimensional corner. Furthermore, we present the experimental results for an actual prototype fabrication. The on-resistance and breakdown voltage are respectively 27 mohm.mm/sup 2/ and 49 V. This on-resistance is reduced drastically in comparison with the conventional trench-gated MOSFET.