Ternary nitride TiZrN films with nano-crystalline grains of 2-10 nm in size and similar to90 muOmega cm in resistivity were successfully prepared as a material applicable to a thin diffusion barrier of low electrical resistivity. In the Cu/TiZrN/Si contact system, a TiZrN film with similar to10 nm thickness is the barrier adequate to suppress the extremely small quantity of Cu penetration into the Si substrate upon annealing at 600 degreesC for 1 h without significant structural change and solid-phase reaction. The observed stable nano-crystalline structure and chemically inert characteristic of TiZrN were the dominant features for the successful demonstration of high performance barrier properties of thin TiZrN films. (C) 2003 Elsevier Science B.V. All rights reserved.