Annealing Effect on the Microstructure and Mechanical Properties of a Thin Titanium Nitride Film

Titanium nitride (TiN) films were deposited by the D.C. magnetron sputtering process on a SUS 304 steel substrate. The effect of postdeposition annealing on the microstructure and mechanical properties of thin TiN films was studied in detail using atomic force microscopy, a potentiostat and nano-indentation tests. The TiN films were annealed at temperatures ranging from 100 to 300A degrees C. Surface roughnesses of TiN films estimated by atomic force microscopy decreased from 3.83 to 2.43 nm as the annealing temperatures increased from 100 to 300A degrees C. The corrosion rates of the films measured by a potentionstat in a 0.5-molar H2SO4 solution decreased from 8.57 center dot 10(-2) to 4.59 center dot 10(-2) mmPY as the annealing temperatures increased from 100 to 300A degrees C. An increase in corrosion resistance was attributed to an increase in hardness and a modulus of the film with the annealing temperature. Atomic force microscopy images of the film revealed fine-grained morphology for TiN films annealed at higher temperature. Experimental results show that the mechanical properties of TiN films could be significantly improved by annealing. The control of the annealing process was proved to be critical for the improvement of TiN film properties.