The main objective of this work is the preparation of decorative zirconium oxynitride, ZrOxNy, thin films by dc reactive magnetron sputtering. Film properties were analyzed as a function of the reactive gas flow and were correlated with the observed structural changes. Measurements showed a systematic decrease in the deposition rate with the increase of the reactive gas flow and revealed three distinct modes: (i) a metallic mode, (ii) a transition mode (subdivided into three zones), and (iii) an oxide mode. The measurements of target potential were also consistent with these changes, revealing a systematic increase from 314to337V. Structural characterization uncovered different behaviors within each of the different zones, with a strong dependence of film texture on the oxygen content. These structural changes were also confirmed by resistivity measurements, whose values ranged from 250to400μΩcm for low gas flows and up to 106μΩcm for the highest flow rates. Color measurements in the films revealed a change from bright yellow at low reactive gas flows to red brownish at intermediate flows and dark blue for the films prepared at the highest flows. Hardness measurements gave higher values for the region where larger grain sizes were found, showing that the grain growth hardening effect is one of the main parameters that can help explain the observed behavior. Also the peak intensity ratio and the residual stress states were found to be important factors for explaining this behavior.

The main purpose of this work consists on the preparation of single layered zirconium oxynitride, ZrN x O y , thin films, deposited by rf reactive magnetron sputtering. The depositions were carried out by varying the process parameters such as substrate bias voltage and flow rate of the reactive gases. Independently of O content, the samples prepared with oxygen fractions revealed crystalline structures basically constituted by face centred cubic ZrN grains. Atomic force microscopy (AFM) observation showed lower values of surface roughness for low oxygen fractions and a second region where roughness grows significantly, corresponding to the highest oxygen fractions. Ion bombardment promoted a continuous smoothing of the surface up to a bias voltage of À66 V. At a bias voltage of À75 V, roughening is again observed. The small increase of film hardness in low oxygen fractions ZrN x O y films was attributed to lattice distortions occurring as a result of the possible oxygen incorporation within the ZrN lattice and also grain size reduction. Residual stresses appeared to be an important parameter to explain the observed behaviour, namely in the group of samples prepared with variation in the bias voltage. Regarding colour variations, it was observed a clear dependence of the obtained colorations with oxygen fraction.

No abstract

No abstract

Raman spectroscopy has been used as a local probe to characterize the structural evolution of magnetron-sputtered decorative zirconium oxynitride ZrO x N y films which result from an increase of reactive gas flow in the deposition The lines shapes, the frequency position and widths of the Raman bands show a systematic change as a function of the reactive gas flow (a mixture of both oxygen and nitrogen). The as-deposited zirconium nitride film presents a Raman spectrum with the typical broadened bands, due to the disorder induced by N vacancies. The recorded Raman spectrum of the zirconium oxide film is typical of the monoclinic phase of ZrO 2 , which is shown also by X-ray diffraction. Raman spectra of zirconium oxynitride thin films present changes, which are found to be closely related with the oxygen content in films and the subsequent structural changes.