Synthesis Of TiN Thin Film Via Reduction-Nitridation Reaction Based On Nohydrolysis Sol-Gel Method

TiN thin films with high hardness, good electrical conductivity ando pticalproperties, and biocompatibility, have been widely used in mechanical, electronics andmedicine fields. When TiN thin films were synthesized based on hydrolysis sol-gelmethod, titanium alkoxide as raw material had high hydrolytic reactivity and itshydrolytic product had low reactivity activity. In this sudy, TiO2thin films weresynthesized by the nonhydrolytic sol-gel method which had higher reactivity activitynonhydrolytic product. And then TiN thin films were synthesized reduction-nitridationreaction based on nonhydrolytic sol-gel method.Firstly, the carbon thermal reduction-nitridation process of TiO2/PVP gelsynthesized via the hydrolytic sol-gel and nonhydrolytic sol-gel method, respectively,was studied by DTA-TG, XRD and SEM. The results show that the transformation ofanatase to rutile was delayed, the intermediate crystal grain was refined and had higherreduction-nitridation activity, as the nonhydrolytic method was used. So that the TiN thinfilm with higher purity and good crystallinity was synthesized by reduction-nitridationreaction based on this method.Then, the influence of precursor solution on the microstructure, optical andmechanical properties of TiN films were studied. Increasing PVP molecular weight, TiNcrystal grain size increased, grain boundary decreased, and its visible light transmittanceincreased. The dosage of PVP increased appropriately, TiN films thickness increased, thecrack of TiN films decreased. And it became more uniform density with the dosage ofsolvent increasing. TiN films had good near infrared reflectance and high microhardness.Secondly, the influence of carbon thermal reduction-nitridation process on the TiNfilms were also studied. When temperature was1300℃, soaking time was5h, nitrogenflux was30-40ml/min, higher purity TiN thin films with perfect crystal grain could besynthesized. Its near infrared reflectivity was closed to70%, and the microhardness of thesubstrate coated TiN films was high to1000kg/mm2.