Schottky barrier diode fabricated on oxygen-terminated diamond using a selective growth approach

A Schottky barrier diode (SBD) fabricated on oxygen-terminated diamond using a selective growth approach is demonstrated. Patterned tungsten (W) film was used as the mask, and ohmic contact was formed between W and diamond during the selective growth process. After growth, the selective epitaxial diamond surface was treated by UV-ozone to achieve oxygen termination. Then, Zr/Ni/Au Schottky electrode was patterned on the selective grown diamond surface. The I-V characteristics indicate that the SBD is p-type, and a rectification ratio of more than 5 orders of magnitude at ±20 V at room temperature is observed. The acceptor might be introduced by W incorporated into diamond during selective growth process, and its concentration was determined to be 2.7 × 10¹⁴ cm^{− 3} from C^{− 2}-V curve. The reverse breakdown voltage of the SBD is 1316 V, corresponding to a breakdown electrical field of 6.3 MV/cm. The reverse current-voltage characteristics show that the UV ozone treatment can favorably suppress reverse leakage current.