IrO 2 Schottky contact on <i>n</i>-type 4H-SiC

A thermally stable IrO2 Schottky contact on n-type 4H-SiC was achieved by annealing an Ir contact under O2 ambient. The IrO2 contact exhibited a high Schottky barrier height of 2.22 eV and low reverse leakage current. Little degradation in Schottky barrier height was observed even after annealing at 450 °C for 24 h under atmospheric air. The oxidation annealing transformed the Ir layer into IrO2, resulting in the increase in the work function of the contact layer. Simultaneously, Si atoms diffused out, leaving the Si vacancy below the contact. These played a role in forming a thermally stable Schottky contact with a high Schottky barrier height.