Modeling and simulation of non-ideal characteristics of vertical Mo/diamond Schottky barrier diode based on MIS model

Abstract

Modeling and simulation of non-ideal characteristics of a vertical Mo/diamond Schottky barrier diode (n = 7.677 and Schottky barrier height= 0.8554 at 298 K) were performed in finite element software. Diode's measured forward and reverse bias I V  characteristics at different temperature were presented and analyzed based on Metal-Interfacial layer-Semiconductor (MIS) model with interface states charges to explain the high ideality factor and Fermi level pinning at the Schottky metal-diamond interface. Current transport through the interfacial layer was simulated with Non-local tunneling model with Wentzel-Kramers-Brillouin (WKB) approximation. By combining characterization results and numerous simulations, we determined the values of unknown parameters (related to interfacial layer and energy distribution profile of the interface states charges) to best fit the forward and reverse bias I V T   characteristics simultaneously. Good fittings to the experimental data validate the use of MIS model. The best fitting was obtained with acceptor traps concentration of 1.3x10 13 to 2.7x10 13 eV-1 cm-2. From reverse bias simulations, it was found that high electric field occurs inside the interfacial layer, especially at the corner of Schottky contact (~11.8 MV/cm). To avoid premature breakdown and realize true potential of diamond material, special attention on the metal-diamond interface must be paid.