Characterisation and properties of magnetron sputtered nanoscale bi-layered Ni/Ti thin films and effect of annealing

摘要

Single-bi-layer of Ni-Ti thin film was deposited using DC and RF magnetron sputtering technique by layer-wise deposition of Ni and Ti on Si(100) substrate in the order of Ni as the bottom layer and Ti as the top layer. The deposition of these amorphous as-deposited thin films was followed by annealing at 300 degrees C, 400 degrees C, 500 degrees C, and 600 degrees C temperature with 1-h annealing time for each to achieve crystalline thin films. This paper describes the fabrication processes and the novel characterization techniques of the as-deposited as well as the annealed thin films. Microstructures were analysed using FESEM and HRTEM. Nano-indentation and AFM were carried out to characterize the mechanical properties and surface profiles of the films. It was found that, for the annealing temperatures of 300 degrees C to 600 degrees C, the increase in annealing temperature resulted in gradual increase in atomic-cluster coarsening with improved ad-atom mobility. Phase analyses, performed by GIXRD, showed the development of silicide phases and intermetallic compounds. Cross-sectional micrographs exhibited the inter-diffusion between the two-layer constituents, especially at higher temperatures, which resulted either in amorphization or in crystallization after annealing at temperatures above 400 degrees C. Copyright (c) 2015 John Wiley & Sons, Ltd.