INVESTIGATION INTO THE EFFECT OF AUGER RECOMBINATION ON CHARGE-CARRIER TRANSPORT AND STATIC CHARACTERISTICS OF SILICON MULTILAYER STRUCTURES

A new model for charge carrier transport through a silicon multilayer structure at high current density is presented. This model accounts fo r a number of nonlinear physical phenomena (electron-hole scattering, Auger recombination, high doping effects) which become of significance at high current density. The injected charge carrier distribution in the lightly doped layer of the structure at high current density was i nvestigated on the basis of this model and previously predicted phenom enon of injected carrier saturation is confirmed. The dependence of in jected carrier limiting density on the electrophysical parameters of t he silicon structure was investigated. Within the framework of the sug gested model the current-voltage characteristics of a p(+)-n-n(+) stru cture was studied. It is demonstrated that injected carrier saturation phenomenon results in linear current-voltage characteristics at high current densities. A characteristic ratio (W/L)(C) (where W is the wid th of the n-base layer and L is the ambipolar diffusion length of char ge carriers in the n-base layer) was found to divide the diode structu res into two groups. In the first group with W/L < (W/L)(C) the recomb ination of injected carriers in the n-base layer at high current densi ty is provided by Auger processes only and therefore the current-volta ge characteristics does not depend on lifetime tau, conditioned by the Shockley-Read-Hall recombination processes. The second group of struc tures with W/L > (W/L)(C) retains a dependence on tau at all current d ensities. Experimental data presented in the last section of the artic le confirm the results of device modeling. (C) 1997 Elsevier Science L td.