Investigation of Static and Dynamic Behavior of Silicon Carbide Semi-Super-Junction Structure in Schottky Barrier Diodes

The static and dynamic characteristics of 650 V class silicon carbide (SiC) semi-super-junction diodes (SJ-SBDs) with pure Schottky contacts, excluding ohmic contacts and MPS structures, were compared with those of a conventional SBD and the body diode in a MOSFET. The SJ-SBDs exhibited lower on-resistance, particularly at high temperatures, and higher avalanche breakdown voltage compared with the conventional SBD. Additionally, higher impurity concentrations in the drift layer were found to decrease the on-resistance of the SJ-SBDs and suppress the increase in resistance at high temperatures. Dynamic characteristics were investigated using a chopper circuit, revealing no significant differences between the SJ-SBDs and conventional SBD at high temperature. The SJ-SBDs exhibited smaller recovery loss compared with the body diode at high temperatures. These findings confirm that SJ structures with Schottky contacts are effective in reducing device losses at both room temperature and high temperature. Therefore, the semi-SJ structure is considered a promising candidate for enabling high-temperature operation in medium-voltage devices.