Atmospheric-pressure plasma deposition of SiOx films for super-hydrophobic application

In this study, we investigate the chemical properties and surface morphology of super-hydrophobic (SH) films deposited by self-assembled RF atmospheric-pressure plasma (APP) deposition system. The O2/HMDSN (hexamethyldisilazane) and Ar serve as the deposition precursor and ionization gas, respectively. The effects of process parameters, including the oxygen flow rate and the nozzle-to-sample distance on the characteristics of SiOx films measured by FTIR, XPS, SEM and AFM are also discussed. It was found that the higher deposition rate was obtained at higher oxygen flow rate conditions. Consequently, the smooth surface was transformed into a rough surface with many particles when the nozzle-to-sample distance was decreased from 20 mm to 10 mm. The SH films (contact angle over 150° and sliding angle below 5°) were obtained when the nozzle-to-sample distance was 10 mm. A simplified deposition mechanism is proposed to explain the effect of process parameters on the films that are formed.