A novel double-recessed 4H-SiC MESFET using scattering the electric field for high power and RF applications

Abstract

In this paper, we present the unique features exhibited by a novel double-recessed 4H-SiC Metal–Semiconductor Field Effect Transistor (MESFET) in which the channel consists of a floating metal region (FMR-MESFET). The key idea in this work is to scatter the electric field lines and modify the ionization mechanism. The floating metal region allows more electrons participate in carrying current, so the optimized results show that the breakdown voltage (VBR) and the drain saturation current (IDsat) increase about 54% and 22% compared with a conventional double recessed MESFET (CDR-MESFET), respectively. Therefore the maximum output power density (Pmax) improved by factor 3.38 in comparisons with conventional one. Also, the cut-off frequency (fT) of 15GHz and the maximum oscillation frequency (fMax) of 135GHz for 4H-SiC FMR-MESFET is obtained compared to 13GHz and 120GHz for that of the CDR-MESFET and the minimum figure noise (Fmin) decreased as a result of reducing gate–drain and gate–source capacitances by about 42% and 40%, respectively. Therefore, the FMR-MESFET has superior RF frequency and high electrical performances.