A Novel 600V Lateral RESURF 4H-SiC MESFET with Sloped Field Plate for High Power and High Frequency Applications

Abstract

Silicon carbide $(SiC)$ possesses a high breakdown field of $4\times 10^{6}V/cm$, high saturated electron drift velocity of $2\times 10^{7}cm/s$ and excellent thermal conductivity of 4.9 $W/cm\cdot K$ attributing from its wide bandgap. These characteristics make this material attractive for incorporating new approaches in device design such as the RESURF (Reduced Surface Field) technology, which is an innovative method for designing lateral high-voltage, low on-resistance devices. We have demonstrated a 600V Lateral RESURF 4H-SiC MESFET with sloped passivation which shows significantly higher power density as opposed to conventional RF GaAs devices and silicon LDMOS transistors. A sloped field plate structure is utilized to drain, source, and gate electrodes to reduce the surface electric field and significantly improve breakdown voltage up to 560V without sacrificing forward on-resistance.