3000V, 25A pulse power asymmetrical highly interdigitated SiC Thyristors

A 3000 V, 25 A asymmetrical Silicon Carbide (SiC) Thyristor for pulse power applications is described here. It was fabricated on ultra low micropipe density 4H-SiC wafers. The device design, fabrication, wafer testing, packaging, static and dynamic characteristics are presented. The devices´ chip area is 4 mm × 4 mm, the yield after screening for blocking voltage, leakage current, forward drop, and latching is over 80%, a very high yield by the standards of SiC power devices. The chips are packaged in a 200°C capable, low profile, surface mount package with a low junction to case thermal resistance. The chips were tested both on-wafer and as packaged parts and exhibit very low leakage current (less than 1 ¿A at 3000 V and 25°C, less than 10 ¿A at 3000 V and 150°C), low forward drop at 25 A (4.55 V at 25A). Several devices were packaged and subsequently tested over several days under high current with no forward voltage degradation observed. While the devices were designed for 3 kV blocking voltage, the actual packaged parts had a breakdown voltage >3.5 kV. Pulse tests were performed to determine the devices´ maximum pulse current, di/dt, and dv/dt performance.