SiO2 protective coatings on plastic optics deposited with plasma-IAD

Plasma ion assisted deposition (plasma-IAD) was used to deposit SiO2 coatings on polycarbonate and on silicon. To study the influence of ion bombardment during the deposition process the bias voltage as an equivalent for ion energy war varied. At a definite bias valur surface microtopography is changed abruptly. Coatings deposited at higher bias voltages show a stable chemical composition and therefore constant optical properties can be expected. It was also found that the barrier effect of coatings against moisture uptake, measured for polycarbonate substrates, increases with bias voltage.