Nb concentration dependent nanoscale electrical transport properties of granular Ti_1−x Nb _x 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.