Heavy-ion ERDA and spectroscopic ellipsometry characterization of a SiOC:H layered structure as functional coating on polymeric lenses

In order to improve the optical and mechanical performance of plastic ophthalmic lenses the use of surface coatings is necessary. However, the application of such coatings can be limited by bad adhesion to the substrate. One way to overcome this drawback is the use of a layered structure consisting in an adherent layer, an abrasion resistant hard layer and an antireflective (AR) multilayer (ML) stack. In this work we study the preparation of SiOxCy:H layered coatings to increase the mechanical durability of polymeric substrates and to accommodate gradually an external dielectric SiO2/TiO2 AR-ML. The coatings were grown by plasma assisted chemical vapor deposition (PACVD) using a mixture of hexamethyldisiloxane (HMDSO) and O2. The possibility of producing the whole layered stack by adjusting the HMDSO:O2 ratio was checked by analyzing the resulting elemental profiles obtained from ERDA. Finally, the optical properties of the different layers have been studied by spectroscopic ellipsometry in order to corroborate the adequate optical performance of the complete coating.