Characterization of Ti-B-C-N films deposited by dc magnetron sputtering of bicomponent Ti/B4C target


I. M. Frantsevich Institute for Problems of Materials Science of the NAS of Ukraine, Omeliana Pritsaka str.,3, Kyiv, 03142, Ukraine
Journal of Superhard Materials, 2015, Т.37, #1


Quaternary Ti-B-C-N films have been deposited onto Si (100) substrates by dc magnetron sputtering of bi-component Ti/B4C target in an Ar/N2 gas mixture with different amounts of nitrogen in the mixture (from 0 to 50%). The X-ray diffraction, X-ray photoelectron spectroscopy, indentation, and scratch tests have been employed to characterize the films. The films have been found to have the nano-composite structure composed of Ti/TiB nanocrystallites (nc) solely when sputtered in argon or of nanoc-rystallite nc-TiN/nc-TiBx /nc-TiOx phases embedded into an amorphous a-C/a-CN/a-BN/a-BC matrix when nitrogen is added to the gas mixture. The latter structure is specific of all the films deposited with nitrogen irrespective of the nitrogen amount in the gas mixture. It has been found that the Knoop hardness of films first increased with added nitrogen reaching maximum value of 33 GPa at 25% N2 in the gas mixture, and then decreased. The friction coefficient of films changed little with the added nitrogen, while with 25% N2 exhibited the lowest value. The Ti-B-C-N films showed increased adhesion strength on silicon compared with Ti-B-C coatings