Silicon Carbide bipolar power devices - potentials and limits

Abstract

ABSTRACTBipolar devices made with SiC offer 20–50X lower switching losses as compared to conventional semiconductors, and a comparable on-state voltage drop at sufficiently high current densities. To exploit the tremendous advantages offered by SiC for bipolar power devices, it is important to understand the relevant voltage/current range, fundamental limits and technological challenges in order to develop this technology commercially. The opportunity of operating a device at a high current density (>300 A/cm2) to increase total current with reasonable yield, the poor reliability of MOS at high temperatures, and the relatively low channel mobilities obtained in 4H-SiC MOSFETs may make certain bipolar devices more attractive even as low as 1700 V. The total power loss in various bipolar devices is analyzed and compared to fundamental operational limits in order to find the applicability of various devices to advanced applications.