A comparative study of Schottky barrier heights and charge transport mechanisms in 3C, 4H, and 6H silicon carbide polytypes

Abstract

This study undertakes a comparative analysis of Schottky diodes using three prominent SiC polytypes (3C, 4H, and 6H). The comparison involves meticulous calculations of the Schottky barrier resulting from the metal/SiC interface for each polytype assessed in both practical and theoretical scenarios. Specifically, the barrier height (ΦB) is systematically plotted against the metal work function (ΦM) across a range of metal work functions from 3.65 to 5.65 eV. Furthermore, the investigation extends to the saturation currents of three distinct charge transport models for each SiC polytype: thermionic current (TE), thermionic field emission, and field emission. Initial analyses plot saturation currents as a function of concentration within a temperature range of 100–500 K. Subsequent examinations plot saturation currents as a function of temperature across a concentration gradient from 1014 to 1020 cm−3. The comparison between the activation energy and thermal energy at standard room temperature (T = 300 K) yielded results consistent with theoretical predictions, affirming the robustness and applicability of each model within its dominant range.