High-rate HMDSO-based coatings in open air using atmospheric-pressure plasma jet

This work deals with the high-rate and dust-free formation of carbon-containing silicon oxide (SiOC) coatings in open air without substrate heating using an atmospheric-pressure (AP) plasma jet. The AP plasma was excited by a 13.56-MHz radio frequency (RF) power. Hexamethyldisiloxane and oxygen (O2) were used as the source gases. By optimizing the O2 flow rate and RF power, SiOC films were readily fabricated at deposition rates higher than 100 nm/s without suffering from particulate contaminations of the film surface. Additionally, an inorganic SiO2-like film exhibiting O/Si atomic ratio of approximately 2 was obtained at a deposition rate of ~ 13 nm/s, the value of which is still greater than those obtained in other AP plasma sources. Further systematic studies are needed to see if good-quality inorganic SiO2-like films can be obtained with higher rates.