Study of a novel two mesas termination SiC Schottky barrier diode

A SiC Schottky barrier diode (SBD) with a novel junction termination structure including two mesas and one P+ guard ring was proposed and demonstrated. Under reverse bias, charge will be attracted to the position of guard ring instead of concentrating at the edge of Schottky junction due to the existence of the first mesa. In addition, the second mesa will further cause the high electronic field expanding vertically, thus optimizing the electronic field region distribution. The dependence of peak electric field on mesa dimensions and guard ring are studied systematically. It was found that the peak electric field was greatly affected by the first mesa height and the guard ring concentration, while there was no obvious variation tendency between the peak electric field and the first mesa width as well as the guard ring depth. Moreover, the thickness of SiC epi-layer can be used adequately and the area of SiC epl-layer can also be reduced for fabricating the same level devices.