Narrow and wide pulse evaluation of silicon carbide SGTO modules

Silicon carbide Super-gate turn-off thyristors (SGTOs) are currently being pursued by the Army as a substitution for present silicon-based, pulsed-power switches. The solid-state modules discussed in this paper were designed and fabricated by Silicon Power and Cree, packaged by Arkansas Power Electronics, and evaluated at the Army Research Laboratory. The module consisted of four SiC GTO die that were packaged implementing Thinpak technology. The die size for each switch in the module was 7.76 mm × 7.76 mm with a total active area of 2.4 cm². Several modules were delivered to the Army Research Lab for pulse switching evaluations. The device characteristics examined from the pulse evaluation were maximum peak current capability, 1000-pulse reliability switching, action, current rise time rate, and current sharing within the module. An update on the module´s performance since the pulse work presented at the 2010 Power Modulator Conference is highlighted in this paper. The repetitive wide-pulse switching of the SiC module resulted in a peak current pulse of 5 kA, which corresponds to an action (I²t) of 1.3 × 10⁴ A²s. The narrow-pulse evaluation of the SGTO module utilized a pulse forming network with low inductance to obtain very high rate of current rise (dI/dt). The narrow-pulse performance obtained for the SiC module was a peak current pulse of 8 kA with a base pulse-width of 170 μs, which corresponds to an action rate of 5.0 × 10³ A²s and a dI/dt of 720 A/μs. This paper also highlights the comparison of the pulse output characteristics of the SiC module to a Si SGTO with similar mesa area.