Characteristics of an epitaxial Schottky barrier diode for all levels of injection

Abstract

The effect of the minority carrier recombination on injection ratio and charge storage time of an epitaxial Schottky barrier (SB) diode has been presented. The dependence of injection ratio and storage time on the minority carrier reflecting properties of the epitaxial-substrate interface is also studied when the drift region of a SB diode is fully invaded by the minority carriers. The study shows that at a relatively low current density, the conductivity modulated region partially occupies the drift region and the charge stored within the injection region cannot be neglected. In the present work, this region is considered for the first time in studying the characteristics of the SB diode. Analytical expressions for the diode forward current, minority carrier injection ratio and storage time parameters are obtained; and the derived expressions are applicable for all levels of injection. In the previous works, to model the complete range of injection level in the SB diode, empirical formulas were introduced to combine the high-level injection model with the traditional low-level current–voltage equations.