Structure and hardness of quaternary TiZrSiN thin films deposited by reactive magnetron co-sputtering

• Phase formation upon Si addition in magnetron sputtered TiZrN films is investigated.
• Films evolve from cubic solid solution to nanocomposite with increase of Si content at 600 °C.
• Amorphous films were obtained at 270 °C at higher Si content due to N-deficiency.
• The maximum hardness values (26–29 GPa) are observed for nanocomposite films.

The addition of Si into (Ti,Zr)N films is considered to be perspective for their hardness enhancement as well as improvement of oxidation and wear resistance. In the present work, the influence of the silicon content and deposition temperature (270 and 600 °C) on the structural and mechanical properties of magnetron sputtered TiZrSiN films is investigated. The elemental composition was determined by Rutherford backscattering and wavelength dispersive X-ray spectrometry methods, the structure and phase formation were analyzed by transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. Depending on Si content, x, and deposition temperature, Ts, (Ti,Zr)1 − xSixNy films were formed in the following states: i) single-phase, cubic (Ti,Zr)N solid solution, ii) dual-phase nanocomposite consisting of nanograins of c-(Ti,Zr)N solid solution surrounded by an amorphous SiNz phase, iii) amorphous phase. Higher deposition temperature (Ts = 600 °C) promotes the formation of nanocomposite structure and reduces the intrinsic compressive stress. The maximum hardness values (26–29 GPa) are observed when Si content is in the range 0.07 ≤ x ≤ 0.15 for both deposition temperatures.