Establishing the cause of poor device quality in Schottky barrier diodes fabricated on bulk n ‐type 6H‐SiC

Abstract

Conventional room temperature electrical evaluatory measurements conducted on Schottky barrier diodes fabricated on bulk n-type 6H-SiC reveal poor ideality values (degrading with time), an absence of hysteresis effects as examined via room temperature bi-directional capacitance-voltage (C-V) measurements, inconsistencies associated with barrier height determination via current-voltage and C-V techniques, and high values of reverse leakage current (improving with time). The measure of thermally dependent barrier lowering associated with these devices is shown to be well in excess of predicted values coupled to the influence of band gap narrowing. Results of calculations undertaken in a preliminary attempt to account for poor device quality are reported. These are in keeping with deep level transient spectroscopy results reported elsewhere where diode behaviour has been coupled to the presence of a band of interface states arising from the annealing procedure employed for diode fabrication.