Characterization of hydrophobic thin films prepared using a cold cathode ion source and plasma deposition

摘要

Hydrophobic coatings are usually applied to optical components in order to prevent wetting, fog accumulation, and in order to keep them clean. Traditionally, hydrophobic catings are fabricatied by a spin or dip process, but hydrophobic materials may also be evaporated in an optical coating chamber as a final layer in the process. Denton Vacuum Inc. has been working of developing an in-chamber plasma process to deposit hydrophobic films using a cold cathode ion source, while a oasma polymerization process has been investigated at the Ecole Polytechnique. In the proesent work we characterize the structure and properties of such flurocarbon hydrophobic layers using a multitechnique approach, comrpising contact angle goniometry, X-ray photoelectron spectros-copy, and atomic foce microscopy. e point out the importance of surface heterogeneity on the contact angle hysteresis, and we evaluate surface aging using an accelerated test.