Influence of chromium buffer layer on Cr/ta-C composite films

Cr buffer layers of six different thicknesses (100, 200, 300, 400, 500 and 600 nm) were respectively deposited on silicon substrate so as to constitute a series of Cr implantation layer/Cr buffer layer/tetrahedral amorphous carbon (ta-C) films. Analysis by SEM suggests that the implantation of Cr layer favourably improves the interfacial transition between ta-C film and Si substrate. X-ray diffraction detection reveals that the difference in thickness of Cr buffer layer does not significantly influence the crystalline structure. Raman result shows that the ductility of Cr buffer layer favours to remit stress of the ta-C film. Increase in Cr buffer layer thickness results in the reduction of nanohardness value. However, its elastic modulus and adhesion exhibit an initial increase followed by a decreasing fluctuation. Result of the study shows the accomplishment of superior mechanical properties for the ta-C film with 200 nm thick Cr buffer layer. © 2013 Institute of Materials, Minerals and Mining.