4.3mΩcm², 1100V normally-off IEMOSFET on SiC

Abstract

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 stacked two epitaxially grown p-type layers and n-type region between the p-wells is formed by ion implantation. This device exhibited a low on-resistance of 8.5mΩcm² with a blocking voltage of 600V. 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 and following low-concentration p-epitaxial growth. Fabricated IEMOSFET with a buried channel exhibited superior characteristics than DEMOSFET. The extremely low specific on-resistance of 4.3mΩcm² was achieved with a blocking voltage of 1100V.