Analysis of tunneling probability in heavily doped 4H-SiC Schottky barrier diodes based on complex band structure considering barrier potential

Abstract

The tunneling probability in heavily doped 4H-SiC Schottky barrier diodes (SBDs) is analyzed based on the empirical pseudopotential method (EPM). A method of calculating the tunneling probability within the Wentzel-Kramers-Brillouin (WKB) approximation using the EPM electronic states of bulk 4H-SiC has been reported. In the present study, to investigate the validity of this method, the tunneling probability is calculated by connecting the incident, transmitted, and reflected wavefunctions considering the barrier potential of a SBD instead of using the WKB approximation. Comparing the calculated results with and without the WKB approximation, the difference is found to be rather small. This suggests that we can safely use the WKB approximation with the bulk electronic states, which are obtained without considering the barrier potential, when calculating the tunneling current in the heavily doped 4H-SiC SBDs.