Breakthrough of on-resistance Si limit by Super 3D MOSFET under 100V breakdown voltage

Under 100V breakdown voltage, a new device structure is required for the purpose of reducing on-resistance and for high reliability. In this study, it was demonstrated that the Si limit of on-resistance was broken by Super 3D MOSFET structure in an actual prototype fabrication. This Super 3D MOSFET has a wide current path in the depth direction without enlarging its surface area. Its on-resistance was 16.4 m¿·mm2 at the breakdown voltage of 58V. This on-resistance was below the Si limit and the lowest result ever reported. Moreover, it was clarified that the UIS (unclamped inductive switching) endurance of this device was 3.08 J/cm2 with 3 mm × 3 mm size chip and this result was 1.5 times stronger than that of conventional structure. This Super 3D structure was fabricated by simplified trench filling epitaxial process and high aspect ratio trench etching process. The Super 3D MOSFET is very attractive for automotive motor drive use.