High temperature operation of alpha -silicon carbide buried-gate junction field-effect transistors

The high temperature operation of alpha -SiC buried-gate junction field-effect transistors is reported. Devices fabricated with a 4 mu m gate length have a maximum transconductance of 17 mS/mm and a maximum drain saturation current of 450 mA/mm at room temperature. The devices are completely pinched off at a gate voltage of -40 V. Devices with a gate length of 39 mu m have a transconductance of 5.4 mS/mm at room temperature which decreases to 1.7 mS/mm at 400 degrees C. This decrease in transconductance is due to the reduction of mobility with increasing temperature. The values of transconductances at room temperature and at elevated temperatures are the highest reported for alpha -SiC JFETs.