Dynamics of modification of Ni/n-GaN Schottky barrier diodes irradiated at low temperature by 200 MeV Ag14+ ions

Abstract

Ni/GaN Schottky barrier diodes were irradiated with 200 MeV Ag ions up to fluence of 1 × 1011 ions/cm2 at the substrate temperature of 80 K. Post-irradiation current-voltage measurements showed that the ideality factor, n increased and the reverse leakage current, IR decreased with increase in fluence. But Schottky barrier height, φb increased only marginally with increase in ion fluence. In situ resistivity measurements showed orders of magnitude increase in resistivity of GaN epitaxial film with irradiation fluence. Cross-sectional transmission electron microscopy images revealed the presence of defect clusters in bulk GaN after irradiation. © 2014 AIP Publishing LLC.