High rate deposition of TiO 2 and SiO 2 films by radical beam assisted deposition (RBAD)

Abstract

Radical beam assisted deposition (RBAD) is an advanced and attractive technique compared with the conventional vacuum evaporation process. In this study, TiO 2 and SiO 2 films were deposited from Ti and Si metals onto glass substrate by RBAD. Atomic oxygen radicals were produced by a beam source using a RF plasma tube. The atomic oxygen radical beam flux (AORBF) density could be achieved to be more than 1×10 15 (atom cm −2 s −1). The refractive indices n of the TiO 2 films were higher than 2.35, and the extinction coefficients k were lower than 3×10 −3 at the deposition rate of 1.8 nm s −1 when the AORBF density was 8.4×10 15 (atom cm −2 s −1). For the SiO 2 film, n was 1.48, and k was lower than 1.5×10 −3 at the deposition rate of 2.4 nm s −1. Moreover, n of the TiO 2 films could be increased to 2.50 by adding an ion beam flux to the radical beam flux. From these results, it is confirmed that TiO 2 and SiO 2 films deposited by RBAD have good optical properties even at higher deposition rates.