Application of droplet-free metal ion source to formation of gas barrier thin films

This paper reports on application of droplet-free aluminum ion sources for formation of gas barrier coating of PTFE polymer sheets. Addition of oxygen to the ion source was also made in order to obtain transparent coating films of alumina. Optimized conditions on the oxygen addition allowed the transparent almina films to be formed without a significant decrease in deposition rate. Square-wave-modulated bias voltages were also applied to the sheet with the film in order to control the incident ion bombarding energy, and was much effective for improvement of gas barrier performance. However such a bias effect was obtained only under a discharge condition that the aluminum ions were efficiently produced. The alumina films had less bias effect than the aluminum films. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)