Smooth and Self‐Similar SiO2‐like Films on Polymers Synthesized in Roll‐to‐Roll Atmospheric Pressure‐PECVD for Gas Diffusion Barrier Applications

SiO2‐like layers deposited by means of the developed atmospheric pressure glow‐like DBD assisted CVD technology exhibit remarkable film properties, reported for the first time. The films synthesized in a roll‐to‐roll mode on polymeric webs, are as smooth as the substrate, irrespectively of the precursors (TEOS or HMDSO) and reactive gases (N2 or air) employed. Detailed AFM investigation on film morphology, surface roughness and auto correlation length (ξ) show that they are negligibly influenced with thickness and are similar to that of the polymeric substrate, indicating the self‐similar growth of the SiO2‐like layers in AP‐PECVD. The films are uniform with no defects or particle being incorporated during the deposition process. The produced single layers on polymeric substrate show excellent gas barrier performances towards O2 and H2O permeation (OTR: <5 × 10−3 cm3·m−2·day−1 and WVTR: <5 × 10−3 g·m−2·day−1). magnified image