The Role of Near-Interface Traps in Modulating the Barrier Height of SiC Schottky Diodes

The role of traps in the operation of Schottky barrier diodes is poorly understood. To explore this, SiC Schottky barrier diodes with a high density of near-interface traps were intentionally fabricated. By applying forward current stress, we demonstrate that the barrier height can be changed by changing the occupancy of the traps. The response time of these traps extends from seconds to hundreds of seconds. We also show that these traps can subsequently be emptied by thermal emission or by tunneling. The results are inconsistent with the existence of an interfacial oxide layer, which shows that the traps are distributed in both energy and lateral depth and, consequently, clarifies their role in creating the Schottky barrier.