Analysis of a New 15-kV SiC n-GTO under Pulsed Power Applications

Silicon carbide (SiC) gate turn-off thyristors (GTOs) are an appropriate option for increased power density and thermal dissipating capabilities in pulsed power and power electronics applications due to their enhanced material characteristics. For the transition of silicon (Si)power devices to SiC, it is imperative to evaluate the long-term reliability of newly developed SiC devices. The testbed for this experiment consists of a pulse forming network (PFN) () that subjects the device under test (DUT) a 15-kV SiC n-type (n-doped epi layer) GTO, up to a current level of 1.0 kA with a pulse width of 120 μs, The static electrical characteristics of the device, such as the forward I- V curve, forward gate conduction, and forward hold-off were taken between testing. Scanning electron microscope (SEM) imaging was used to find physical evidence of degradation on the device. The DUT was subjected to 20,000 high-current density pulses, at which point it exhibited no major changes in blocking capability.