The influence of high energy proton bombardment on the electrical and defect properties of single-crystal ZnO

We report on the electrical and defect characterization of Au Schottky diod es formed on single-crystal ZnO, before and after irradiating with high-ene rgy (1.8 MeV) protons. Prior to bombardment we observed that several electr on traps (E1-E4), with energies between 0.10 and 0.57 eV below the conducti on band, are present in the ZnO. High-energy proton bombardment introduces two electron traps (Ep1 and Ep2), with extremely low introduction rates (et a) of 2.4 and 1.9 cm(-1), respectively. Schottky barrier properties such as the reverse leakage current deteriorated from I x 10(-9) A for an unirradi ated diode to 1 X 10(-6) A after bombarding it with a dose of 4.2 x 10(14) cm(-2) protons. Compared to GaN we found that ZnO is remarkably resistant t o high-energy proton bombardment.