Numerical Analysis of Thermal Sensitivity Characteristics by Pinch-Off Model in Inhomogeneous Schottky Barrier Diodes

Abstract

We have inspected the numerical simulation and the experimental voltage-temperature (V-T) traces of the Pt/epitaxy n-Si/n(+)Si/Au Schottky barrier diode (SBD) as a thermal sensing element, using the modified TE equation by Tung. The experimental V-T data for the thermal sensitivity have been directly measured from 10 K to 320 K with steps of 2.0 K under some forward bias current levels. It has been seen that the experimental V-T traces consist of two linear regions with different slope, which have been ascribed to the barrier inhomogeneity. A striking result of the present work is to show whether the presence of two linear regions and the non-linearity at low temperatures in the V-T curves of thermal diode may be due to barrier inhomogeneity. By accounting for the patch parameters such as the number of patches and standard deviation, sigma, the fits with Tung's model to experimental V-T curves have shown that the presence of nano-sized patches with different barrier heights in SBDs is one of the main causes of undesirable anomalies in the change of thermal sensitivity. It has been seen from fits to the experimental V-T curves that the total effective patch area and the number of patches in the high-temperature region have higher values than those in the low-temperature region. The findings strongly emphasize that the barrier inhomogeneities are the limiting factor when analyzing the thermal sensitivity of the SBDs.