1 Introduction

Thyristors made with Silicon Carbide (SiC) demonstrate great performance advantages over those made with Si or GaAs because of SiC's higher breakdown electric field, carrier saturation velocities and thermal conductivity than either Si or GaAs. A high breakdown electric field allows the design of SiC thyristors with thinner and higher doped base layers than identically rated Si or GaAs thyristors. Such devices show fast switching and low residual voltage drop at very high current densities. A high thermal conductivity should allow higher current density operation of SiC thyristor. The higher bandgap of SiC results in extremely high intrinsic temperature of about 1920 K (for 4H-SiC) for an extrinsic doping of 10 ¹⁶ cm ^-3. Another advantage of high bandgap is negligible leakage currents up to 500-550K. Based on the above arguments SiC thyristors could find use in ultra high-voltage and high current applications with critical constrains on the size, weight, and elevated temperature characteristics of the power unit, such as motor controls for heavy electric vehicles and electric railways.

The...