Fabrication and Initial Characterization of 600 V 4H-SiC RESURF-type JFETs

A RESURF-type JFET is a suitable structure as a lateral switching device with a breakdown voltage of above 600 V for an inverter module which drives motors of an electric or hybrid automobile. In this study, 600 V RESURF-type JFETs were fabricated to investigate the operation and characteristics. The drift region between the drain and the source areas has a double RESURF structure to reduce the on-resistance. At first, small devices were fabricated. The width and length of the channel are 200 μm and 10 μm, respectively. The distance between the drain and the gate areas, which is the drift length, is 15 μm. The saturation current normally-off device is about 0.6 mA at a gate voltage of 3 V. The specific on-resistance is about 160mΩcm2. The maximum breakdown voltage is 720 V. Next, large ones were fabricated. The width of the channel is 80 mm. The saturation current normally-on device is about 0.5 A at a gate voltage of 2 V. The specific on-resistance is about 200mΩcm2. The maximum breakdown voltage is 250 V.