Lateral current flow in thyristors with partially shorted cathodes—I: Two-terminal operation

Abstract

The influence of a partial short in the cathode of a thyristor on current flow in the high-impedance region is investigated in the first of a two-part paper, primarily for two-terminal operation. First, this short is simulated by a resistance R connected between gate and cathode and included in the equations governing current flow. Secondly, an effective current gain, modified by a shorting dot ( SD), is calculated showing, not only current but also geometrical dependence. Thirdly, the lateral current flow in the gated p-region is calculated, for two-terminal operation, from a digital computer solution of a non-linear differential equation—which in principle applies for both two- and three-terminal operation—yielding the current flow into the SD. Some speculations on the influence of gold doping on this lateral current flow are offered and are reconciled with measured differences.