4.3 mΩcm2, 1100 V4H-SiC implantation and epitaxial MOSFET

The channel mobility in the SiC MOSFET degrades on the rough surface of the p-well formed by ion implantation. Recently, we have developed a double-epitaxial MOSFET (DEMOSFET), in which the p-well comprises two stacked epitaxially grown p-type layers and an n-type region between the p-wells is formed by ion implantation. This device exhibited a low on-resistance of 8.5 m Omega cm(2) with a blocking voltage of 600 V. In this study, to further improve the performance, we newly developed a device structure named implantation and epitaxial MOSFET (IEMOSFET). In this device, the p-well is formed by selective high-concentration p(+) implantation followed by low-concentration p(-) epitaxial growth. The fabricated IEMOSFET with a buried channel exhibited superior characteristics to the DEMOSFET. The extremely low specific on-resistance of 4.3 m Omega cm(2) was achieved with a blocking voltage of 1100 V. This value is the lowest in the normally-off SiC MOSFETs.