A study on GTO turn-off failure mechanism—A time- and temperature-dependent 1-D model analysis

A 1-D model is presented for use in analyzing the GTO thyristor turn-off process, including the conduction region squeezing effects as well as the current due to temperature variation, i.e., thermal diffusion and the current due to bandgap variation with temperature change. The model simulates current-voltage characteristics for the current concentrated area, where the current density increases almost linearly with the anode voltage. It is found that the nonuniformity in the p-base sheet resistance is a significant cause for the current concentration because of the enhanced current due to the excess carrier removal from the highly injected n-base. The model also predicts the limitation to the anode voltage imposed on the device before the current is completely turned off.