RF plasma deposition of SiO2-like films: plasma phase diagnostics and gas barrier film properties optimisation

Hexamethyldisiloxane/oxygen fed radiofrequency glow discharges have been utilised for the deposition onto polyethyleneterephtalate of transparent silicon dioxide-like films with barrier properties to oxygen. The complexity of such plasma phases and the increasing interest shown for the industrial deposition process of barrier films have led the authors to investigate Fourier transform infrared absorption spectroscopy as a plasma technique for better understanding of the deposition mechanism and the development of a process control useful for scaling up. The above mentioned technique has shown its potential in the correlation of plasma phase chemistry with the barrier properties of the SiOx coated polymer, especially when very good performances are required (OTR≤3 cm3/m2 day atm).