Intersection of 4H-SiC Schottky diodes I–V curves due to temperature dependent series resistance

Abstract

We theoretically and experimentally analyzed the non-obvious intersections of Schottky diode I–V curves measured at different temperatures caused by increasing the series resistance of the diode with increasing temperature. We considered a homogeneous diode and an inhomogeneous diode with two ways of influencing the I–V curve by the series resistance. In each case we developed a numerical method that enabled anticipation of the I–V intersection point. We studied the Ni/Au/4H-SiC diode for which such an intersection was measured. For homogeneous diodes and temperature interval 300–400 K we found a voltage dispersion of intersection points of only ∼0.002 V, which is in accordance with experimental observations and suppositions in the literature that the curves intersect at almost the same I–V point. Even for an inhomogeneous diode with a common series resistance we obtained a dispersion of the intersection voltage of only ∼0.02 V which is hardly discernible by the common visualization of the I–V curves. The largest dispersion of intersection points was obtained for an inhomogeneous diode composed of non-interacting diode patches.