Material characterization and nanohardness measurement of nanostructured Ta-Si-N film

This paper presents a study of the relation between the process, composition and nanohardness of the nanostructured Ta-Si-N films that have been applied in an IC diffusion barrier or mechanical coating. Ta-Si-N films are reactively cosputtered by individual Ta and Si targets in a N-2/Ar gas. They are characterized by Rutherford Backscattering Spectroscopy (RBS), grazing incident-angle X-ray difftactometer (GIAXRD) and nanoindenter for the composition, structure and nanohardness analysis, respectively. Increasing Si target power or decreasing Ta target power will produce higher Si/Ta composition ratio in Ta-Si-N films with higher amorphous content as well as smaller nanocrystalline grains. The nanohardness of Ta-Si-N films measured by nanoindentation is between 13.5 and 16.4 GPa. Increasing N-2 flow reduces the nanohardness while the grain size of Ta-Si-N film increases slightly. However, increasing Si composition reduces both grain size and nanohardness of Ta-Si-N films. (C) 2004 Elsevier B.V. All rights reserved.