The investigation of the electro-thermal characteristics of a GTO thyristor at turn off using SILVACO ATLAS

An electro-thermal simulation model of a GTO thyristor operating in a pulse-power circuit is documented. The principle goal of this investigation was to examine an apparent current interruption derating advantage of the GTO at low frequency by tracking the generation, transfer, and dissipation of energy within the GTO structure and establishing a clear understanding of the localized heating phenomenon that results in ultimate device failure. Using a SPICE circuit model coupled with a SILVACO ATLAS¿ physical model, a novel energy tracking methodology was used to confirm that the dominant mechanism for thermal energy generation was joule heating. The analysis further distinguished whether that location of joule heating was dominated by high current density or high electric field values. The results of this work suggest that it might be possible to predict the device lifetime by using this simulation approach to establish hot spot temperatures that form during turn off.