Low temperature deposition of TiO2 films with high refractive indices by oxygen-radical beam-assisted evaporation combined with ion beam

摘要

The effect of simultaneous irradiation of an oxygen-(O-IB), an argon-(Ar-IB), a krypton-(Kr-IB), and a xenon-(Xe-IB) ion beam on an oxygen-radical beam-assisted evaporation (O-RBAE) was studied to deposit titanium oxide films with high refractive indices at a low substrate temperature. In O-RBAE, the oxygen-radical beam (O-RB) was irradiated to completely oxidize titanium (Ti), which was simultaneously evaporated onto glass substrate. In addition to O-RB, IB was simultaneously irradiated to deposit dense films. The refractive indices (n), the extinction coefficients (k), and the morphology of the films deposited by O-RBAE with IB (O-RBAE/IB) were compared with those of the films deposited only by O-RBAE. O-IB and Ar-IB irradiation made the deposited films denser. Particularly, in O-RBAE/O-IB, the maximum n-value of the films markedly increased from 2.37 to 2.51, compared with O-RBAE. Then the morphology of the films changed from columnar-like structure to a homogeneous one. As compared with O-IB irradiation, however, the heavier Ar-, Kr-, and Xe-IB irradiation with more ion energy made the deposited films more porous rather than denser. This proved that O-RBAE/O-IB was effective for depositing the titanium oxide films with high refractive indices at a low substrate temperature. (C) 2002 Elsevier Science Ltd. All rights reserved. [References: 14]