Ion bombardment characteristics during the growth of optical films using a cold cathode in source

摘要

In the present work, the energy and flux of impinging ions are evaluaged in the context of ion-assisted depositon of optical films and ion-induced midification of polymer surfaces for improved adhesion. The experiments wer performed in a vacuum system equipped with a broad beam cold cathode ion source. The ion energy distribution functions were measured using a multigrid retarding field analyzer for discharges excited in different gases such as O_2, Ar, and N_2. The ion beam characteristics, namely the maximum ion energy, the mean ion energy, and the ion flux, were correlated with the properties of Ta_2O_5 and TiO_2 layers deposited by e-beam evaporation assisted by an oxygen ion beam. These different materials were anallyzed spectroscopic ellipsometry, spectrophotometry, and profilometry. Their optical and mechanical behavior, such as refractive indes and stress, are correlated with the evolution of the film microstructure.