Microstructure and hydrogen impermeability of titanium nitride thin films deposited by direct current reactive magnetron sputtering

摘要

This work investigated microstructure and hydrogen impermeability of titanium nitride (TiNx) thin films deposited on tantalum substrate by direct current reactive magnetron sputtering. The influence of N-2 flow rate and cathode current on grain size, crystal orientation and chemical state of the films was studied. It is found that when N2 flow rate increases from 5 to 10 and 15 sccm (standard cubic centimeter per minute) while cathode current remains at 0.5 A, the grain size and atomic ratio of N/Ti (represented by x in TiNx) decrease, and the strongest diffraction peak transforms from (111) to (200) plane. On the other hand, when cathode current decreases from 1.5 to 1 and 0.5 A while N2 flow rate remains at 15 sccm, almost the same trends are found except for the crystal orientation. Furthermore, the hydrogen impermeability of the TiN films had been measured by electrochemical technique and its dependence on crystal orientation was discussed. TiN film with (111) texture is found to present better hydrogen impermeability than that with (200) texture. (C) 2016 Elsevier B.V. All rights reserved.