In situ spectroellipsometric analysis of plasma treatments of polymers for the adhesion improvement of silica thin films

Plasma enhanced chemical vapour deposition (PECVD) is increasingly used for the fabrication of functional coatings on polymeric substrates. Frequently a preliminary plasma treatment is used to increase the adherence of the deposited films. In this paper we use spectroscopic phase modulated in-situ ellipsometry from the UV to the infrared range to investigate the influence of plasma pretreatments of polycarbonate and polypropylene substrates. UV-visible ellipsometry is found to be a valuable tool for studying polymer etching and degradation processes, whereas infrared ellipsometry, due to its high surface sensitivity, is particularly usefull in studying the surface functionalisation under reactive plasmas.