Microstructure and chemical state of Ti1-xYxN film deposited by reactive magnetron sputtering

A feasibility of using Ti1-xYxN as a hard coating material was investigated. Coatings were made on a Si(100) surface as well as on a steel surface using a dual-target rf-dc reactive magnetron sputtering method with the range of Y varying from x = 0 to x = 0.16. By x-ray diffraction analysis, it was found that all the coated films were of a single phase with a NaCl structure, with their lattice parameters increasing with Y content. A transmission electron microscopy analysis of the coated him revealed fine columnar grains in the samples containing high NY. This was attributed to Y atoms of low surface mobility and a strong bonding tendency with oxygen. The Y atoms promote the rate of heterogeneous nucleation by easily forming fine oxide particles at the substrate surface. From x-ray photoelectron spectroscopy analysis, it was learned that the binding energies of Y 3 d(5/2) and N 1 s in YN bonding were 157.8 and 397.5 eV, respectively. The optimum combination of microhardness and adhesion strength was obtained in Ti0.928Y0.072N film. In an oxidation resistance test at 800 degreesC, the TiN films with high Y content performed better than pure TiN film. The oxide scale in this case consisted of rutile TiO2, anatase TiO2, and Y2Ti2O7, in which Y 3d(5/2) and O Is had binding energies of 158.7 and 530.8 eV, respectively. Overall, the present study suggests a good feasibility of utilizing Y in TIN hard coating material. (C) 2000 American Vacuum Society. [S0734-2101(00)04906-X].