Effect of the geometric shape of nanostructures formed on Cu oxide thin films by the stress-induced migration on electrical characteristics

Electrical characteristics of Cu oxide thin films with different nanostructures were investigated for gas sensor applications. Nanowires and hillocks were formed on the Cu oxide thin films by the stress-induced migration, and the current-voltage characteristics of these films were measured. They showed a combination of ohmic and space-charge-limited conduction. The sheet resistance calculated from the voltage range of ohmic conduction changed in a wide range from 2.1 x 10(3) to 1.4 x 10(7) Omega/sq. Despite the different nanostructures on the films, the sheet resistance was proportional to their volume. Moreover, the temperature dependence of the current-voltage characteristics of the film was examined. The results indicated that the geometric shape of nanostructures on the Cu oxide thin film has a significant effect on electrical characteristics. (C) 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.