Nb concentration dependent nanoscale electrical transport properties of granular Ti < inf > 1-x < /inf > Nb < inf > x < /inf > N thin films

Abstract

Granular Ti1-xNbxN thin films, 0 ≤ x ≤ 0.77, were deposited on borosilicate glass substrates by RF magnetron sputtering. Conductive-atomic force microscopy (C-AFM) was employed to study the local electrical transport properties of Ti1-xNbxN thin films. Topography images reveal that the grain size in the films increased from 30 to 90 nm, as x increased from 0 to 0.77. For a constant applied voltage of 1 V, the local leakage current in Ti1-xNbxN films increased with an increase in x value. The measured current is in the order of nA and its flow is filamentary in nature. Current-voltage characteristics measured at different locations on each current image revealed that the local resistance drastically decreased with an increase in Nb concentration. Electron-grain boundary scattering and the presence of native oxide states are responsible for the increase in the local electrical resistance of the films. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.