Fin-channel orientation dependence of forward conduction in kV-class Ga2O3 trench Schottky barrier diodes

Abstract

Ga2O3 vertical trench Schottky barrier diodes with four different fin-channel orientations are realized on (001) substrates and compared. Fin-channels along the [010] direction with (100)-like sidewalls result in the highest forward current, while other channel orientations all lead to a shallow turn-on behavior and much lower forward current, indicative of severe sidewall depletion attributed to negative interface charges. The comparison indicates that the interface charge density is the smallest on the (100)-like surfaces. The breakdown voltage of the diodes with 1-μm fin width is around 2.4 kV, with no apparent dependence on the channel orientation.