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

摘要

X-ray photoelectron spectroscopy (XPS) has been employed to investigate titanium oxynitride (TiN_xO_y) 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 TiN_xO_y films comprised Ti-N, Ti-N-O, and Ti-O chemical states. When the air/Ar ratio was below 0.3, nitrogen-rich TiN_xO_y films were obtained. As the air/Ar ratio was above 0.4, oxygen-rich TiN_xO_y 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, TiN_xO_y films with large oxygen content with uniform concentrations were then formed.