Reduction of leakage current of 4H-SIC pin diodes after UV light exposure

A substantial reduction of the leakage current in 4H-SiC pin diodes is observed after <10 eV UV irradiation in air. The high energy UV is believed to remove carbon clusters from the SiC surface. Comparison of leakage current in 4H-SiC pin diodes after different surface treatments, including reactive ion etching, exposure to two different sources of UV light and different forms of chemical cleaning, is presented. Exposure to 4.9 eV UV light in nitrogen atmosphere enhances the leakage by one order of magnitude