Fast Switching (41 MHz), 2.5 mΩ-cm2, high current 4H-SiC VJFETs for high power and high temperature applications

In this work we have demonstrated the operation of 600-V class 4H-SiC vertical-channel junction field-effect transistors (VJFETs) with 6.6-ns rise time, 7.6-ns fall time, 4.8-ns turn-on and 5.4-ns turn-off delay time at 2.5 A drain current (I-DS), which corresponds to a maximum switching frequency of 41 MHz - the fastest ever reported switching of SiC JFETs to our knowledge. At I-DS of 12 A, a 19.1 MHz maximum switching frequency has been also achieved. Specific on-resistance (Rsp-on) in the linear region is 2.5 m Omega center dot cm(2) at V-GS of 3 V. The drain current density is greater than 14 10 A/cm(2) at 9 V drain voltage. High-temperature operation of the 4H-SiC VJFETs has also been investigated at temperatures from 25 degrees C to 225 degrees C. Changes in the on-resistance with temperature are in the range of 0.90 similar to 1.33%/degrees C at zero gate bias and I-DS of 50 mA. The threshold voltage becomes more negative with a negative shift of 0.096 similar to 0.105%/degrees C with increasing temperature.