Hollow-cathode activated PECVD for the high-rate deposition of permeation barrier films

• Published in: Surface & coatings technology 2017-03, Vol.314, p.155-159
• Main Authors: Top, Michiel, Schönfeld, Steffen, Fahlteich, John, Bunk, Sebastian, Kühnel, Thomas, Straach, Steffen, De Hosson, Jeff T.
• Format: Article
• Language: English
• Subjects: ArcPECVD; High rate deposition; Hollow cathode; PECVD; WVTR; XRay reflectivity
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2016.09.003

This paper shows a study on the variation of the flow ratio between oxygen and Hexamethyldisiloxane (HMDSO) in a hollow cathode arc PECVD process. Dynamic deposition rates were measured between 300 and 500nm∗m/min. The deposited plasma polymer films were analyzed using visible light spectroscopy, X-ray photo-electron spectroscopy (XPS), X-ray reflectivity (XRR), Fourier-transformed infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and water vapor transmission rate (WVTR) measurements. The deposited samples were compared to a reactively sputtered SiO2 thin film. By increasing the oxygen to HMDSO flow ratio, the chemical, density and optical properties of the coating approached the sputtered SiO2 film. However the permeation barrier of the SiO2 film only shows a slight improvement over that of the bare PET substrate. The organic coating with high power and low oxygen flow, which was deposited with a deposition rate of 450nm∗m/min, approached the barrier of the sputtered SiO2 thin film with a WVTR of 0.16g/(m²day). •A hollow cathode arc discharge is used for high rate deposition of SiOxCyHz layers.•Plasma polymers reduced the water permeation 50× compared to the PET substrate.•The thin film density of the plasma polymers on flexible substrates was measured.•The O2 to HMDSO ratio can be used to control the chemical composition of thin film.