Thyristor element with short turn-off time and method for producing such

Abstract

A fast switching thyristor having a shorted emitter structure in which, in order to shorten the turn-off time, the charge carrier lifetime is set to be low by means of recombination centers. The charge carrier lifetime in at least the control base zone of the thyristor is set initially to be homogeneous and low corresponding to a desired firing resistance underneath the emitter zone with respect to the voltage rise of the returning forward voltage in the thyristor after every recovery process, and the charge carrier lifetime is set to be low compared to the homogeneous setting in the partial region of the control base zone extending from below the control electrode substantially to the portion of the edge of the emitter zone which faces the control electrode but without contacting the edge of the emitter zone. If the thyristor is of the amplifying gate type having a shorted auxiliary emitter structure, then the charge carrier lifetime in the region between the main and auxiliary emitter zones is less than the charge carrier lifetime in the region between the auxiliary emitter zone and control electrode which in turn is less than the homogeneously set charge carrier lifetime in the bulk or volume of the device. Additionally, the density of the shorting channels in the edge region of the auxiliary emitter zone facing the control electrode is greater than in the remainder of this zone and than in the main emitter zone.