Application Of Ion Beam Technology In Ultra-low Loss Films

The ultra-low loss films is widely used in optical instruments. Ion beam technology has been developed from traditional vacuum deposition,and overcomed the shortcoming of traditional vacuum deposition and low cost. Now, it plays an more and more important role in the deposition of the thin films, and has been applyed to all respects of films deposition. So, it has very good application prospects to study the influence of ion beam aided deposition on loss of films.In this paper, based on matrix of monolayer, the theory formula of absorption loss and scattering loss were gotten when the incidence of light wave was 0°, utilizing Fresnel formula. The monolayer films was deposited with different ion aided parameters, and the influence of ion beam parameter(ion energy and ion beam flux density) on loss of those films was studied.The result shows that the refraction index of HfO₂,SiO₂,Ta₂O₅ increases with the increasing of ion energy and ion beam flux density, the extinction coefficient of HfO₂,SiO₂ appears reciprocating up and down with the increasing of ion energy and ion beam flux density, it means that the absorption loss changs repeately. The analysis of films surface shows that the roughness of surface reduces with the increasing of ion energy and ion beam flux density, but the chang is slight. Compared with the traditional heat evaporation technology, the loss of films reduces greatly after using the ion beam technology, high-quality films may be gotten in low ion energy and high ion beam flux density. Compared with experimental result of HfO₂, the refraction index and extinction coefficient of SiO₂ films are not sensitive to the change of the ion energy and ion beam flux density, because of difference of the material itself, so it is right to deposite different materials with different suitable ion energy and ion beam flux density, and it should be treated with a certain discrimination. XRD shows that HfO₂,SiO₂,Ta₂O₅ have typical amorphous noncrystalline structure.Known from XPS that the composition of HfO₂,SiO₂ is very close to the theory value.Based on monolayer, 1064nm anti-reflection double-layers was designed and deposited, the analysis on its loss had verified the right of analysing on loss of the monolayer.