Nonlinear analysis of minority carrier storage time of a uniformly doped Schottky Barrier Diode

Abstract

Minority carrier charge storage time of a uniformly doped Schottky Barrier Diode (SBD) is studied here. When barrier height is low, SBD acts as a majority carrier device. But for a high barrier SBD both majority and minority carrier currents contribute to total current. In the past, a number of research works on uniformly doped SBD have been done but in this work an analytical expression for minority carrier charge profile for a high barrier SBD is derived in a new approach. Both drift and diffusion components of majority and minority carrier currents are considered. Neglecting recombination in the epitaxial layer, a second order nonlinear differential equation is solved to obtain for all level of injections. Once minority carrier charge profile is known, stored excess minority carrier charge, storage time and injection ratio are obtained. Present work represents that minority carrier charge profile, minority carrier charge storage time and injection ratio depend on bias voltage, doping density, effective surface recombination velocity and device length.