A superior 15 kV SiC MOSFET with current spreading layer for high-frequency applications

Abstract

In this study, we developed a superior 15 kV silicon carbide (SiC) metal-oxide-semiconductor field-effect transistor (MOSFET) with a current spreading layer (CSL) implanted with nitrogen ions. This MOSFET was developed for high-frequency applications. The CSL and junction field-effect transistor (JFET) regions were optimized using device simulations to reduce reverse transfer capacitance without increasing on-resistance. A SiC MOSFET with a CSL and a die with a size of 5 mm × 5 mm was fabricated. We simultaneously obtained a specific on-resistance of 191 mΩ cm2, a blocking voltage of 15.0 kV, and a reverse transfer capacitance of 0.75 pF for a narrow JFET width of 1.2 μm. In addition, threshold voltage shifts were kept within ±0.1 V for 1000 h at a gate voltage of −15 V and at a temperature of 200 °C.