9 kV, 1 cm×1 cm SiC super gto technology development for pulse power

Abstract

Power devices made on Silicon Carbide (SiC) are expected to offer significant advantages over silicon due to the unique material properties. With the continuing improvement in both material quality (defect density and carrier lifetime) and SiC device fabrication process, SiC power devices are increasingly fabricated with higher blocking rating and larger die size. This paper describes the benefits of using SiC Gate Turn-Off thyristors (GTO) in power electronics, especially for pulse power applications, reviews the development history and the current state of the art, and outlines the future perspective for developing large area GTOs with high blocking voltage of ≫ 10 kV. Experimental results for the state-of-the-art 9 kV, 1 cm2 SiC GTOs are presented. Static and dynamic characteristics are described. A forward drop of 3.7 V at 100 A (100 A/cm2) is measured at 25°C. A slight positive temperature coefficient of the forward drop is present at 300 A/cm2 indicating the possibility of paralleling multiple devices for higher current capability. The device exhibits extremely low leakage currents at high temperatures. The turn-on delay is found to be a strong function of the gate current, cathode-anode current and voltage. A peak current of 12.8 kA conducted with a pulse width of 17.4 µs indicating the superiority of the SiC GTOs for pulse power applications.