High Temperature Characterisation of 4H-SiC VJFET

Abstract

4H-SiC depletion mode (normally-on) VJFETs were fabricated and characterised at temperatures up to 377 °C. The device current density at drain voltage of 50 V drops down from 54 A/cm2 at room temperature to around 42 A/cm2 at 377 °C which is a 20 % reduction in drain current density. This drop in drain currents is much lower than previously reported values of a 30 % drop in JFETs at high temperatures. The average temperature coefficient of the threshold voltage was found to be -1.36 mV/°C which is smaller than for most Si FETs. We have found that these devices have shown good I-V characteristics upto 377 °C along with being able to retain its characteristics on being retested at room temperature.