X-ray photoelectron spectroscopy analyses of titanium oxynitride films prepared by magnetron sputtering using air/Ar mixtures

X-ray photoelectron spectroscopy (XPS) has been employed to investigate titanium oxynitride (TiNxOy) films prepared by d.c. magnetron sputtering using air/Ar mixtures, which allows one to perform the deposition at a high base pressure (1.3 × 10− 2 Pa) and can reduce substantially the processing time. XPS analyses revealed that all the prepared TiNxOy films comprised Ti–N, Ti–N–O, and Ti–O chemical states. When the air/Ar ratio was below 0.3, nitrogen-rich TiNxOy films were obtained. As the air/Ar ratio was above 0.4, oxygen-rich TiNxOy films were formed. XPS depth profile analyses were also performed in selected specimens. It has been found that at relatively low air/Ar ratios, such as 0.5, the oxygen content of the films increased toward the film/substrate interface and when the air/Ar ratio was higher, TiNxOy films with large oxygen content with uniform concentrations were then formed.