Statistical Modeling of Semiconductor Devices for the Tree Environment

The modeling of semiconductor devices for use with circuit analysis computer codes is a very important endeavor. The accuracy of the model ultimately will determine the accuracy of the analysis and its relation to actual circuit operation. The transistor model used in the Autonetics Transient Radiation Analysis by Computer (TRAC) code is discussed. Particular emphasis is placed on the simulation of radiation-induced photocurrent in the p-n junctions. The photocurrent generator is first derived for a single junction. The result is then extended to the transistor model by appropriately combining two junctions which interact. The interaction is accomplished by including a current transport factor at each junction, as in the Ebers and Molll) formulation. The photocurrents are then examined in terms of defining equations which lead to the criterion for measuring the photocurrent parameters which, in turn, are related to the conventionally defined primary photocurrents in the devices.