Modeling the diode characteristics of boron nitride/silicon carbide heterojunctions

Abstract

In this work, we investigate metal–amorphous semiconductor–semiconductor diodes made up of boron nitride/silicon carbide (BN/SiC) heterojunctions. We show that a general conduction model can be applied to this system to explain the measured current-voltage diode characteristics. The conduction model is based on a serial arrangement of a voltage dependent Frenkel–Poole resistance and an ideal Schottky diode. This model is refined to reflect the presence of an amorphous interface layer with thicknesses of about 7(2) nm between BN films and SiC substrates obtained from high resolution cross-section transmission electron microscopy measurements. We demonstrate that this results in an extended Frenkel–Poole and ideal diode model leading to an almost perfect agreement with the measured I-V characteristics of BN/SiC heterojunctions.