Structural and hydrophilic properties of TiN films prepared by ultrasonic atomization assisted spray method under low temperature

An ultrasonic assisted spraying method was proposed to prepare TiN films in friendly conditions. The particle size effects of the nano-TiN suspensions upon the film structure, morphology, and optical properties were investigated. The results show that the larger particles (170 nm) form a porous structure, while the smaller ones (60 nm) form a dense structure. Both the films display good thermal stability under 700 °C vacuum annealing. The dense film shows a metal-like behavior of abnormal dispersion in the range over 550 nm, and the annealing process increases the carrier concentration by presenting the red shift of the plasma absorption. The water contact angles of porous films are about 0° and 153° respectively, before and after the annealing process. Such a variation could be attributed to the emerging of TiNOx that reduces the surface activity. The above-stated results demonstrate a promising potential to prepare TiN films by ultrasonic spray method and their applications as super hydrophilic or hydrophobic coatings by control annealing process.