Subthreshold characteristics of electrostatically switched transistors and thyristors. II. Deep in-plane gate

Abstract

A rigorous analytic theory is developed for the blocking state of electrostatically switched thyristors and transistors. The problems of the potential distribution in the base, the barrier height for electrons, and the current-voltage characteristic in the subthreshold region are solved in quadratures by conformal mapping for electrostatically switched transistors and thyristors with an arbitrary configuration of an in-plane gate in contact with the source. It is shown that the subthreshold current-voltage characteristics of electrostatically switched transistors and thyristors have a universal form independent of the gate configuration. As an example, a study is made of a quasielliptical in-plane gate that corresponds to the configurations of most real devices. Simple formulas are obtained in limiting cases for the blocking coefficient and the parameters of the current-voltage characteristic as functions of the geometric parameters of the electrostatically switched transistor or thyristor, the base doping, and the gate potential.