Thermal cycling study of SiC BGJFETs

A thermal cycling study of 6H-SiC buried gate JFETs (BGJFETs) was conducted. These n-channel depletion mode (normally on) BGJFETs employed a buried p-n junction as the gate and mesa-epitaxial structures with 6H-SiC(0001) substrates and p- and n-epilayers. The gate contact metal, Ni-Al, was ohmic to the buried gate layer. A large number of devices (more than one hundred) were tested to study the trend of the device behavior at high temperatures. After constant temperature tests, thermal-cycling was done on the good devices.