Optical thin film formation by oxygen cluster ion beam assisted depositions

Abstract

O 2 gas cluster ion beam (O 2 -GCIB) assisted depositions were employed to deposit high quality dielectric films (Ta 2 O 5 , Nb 2 O 5 and SiO 2 ). The optimum irradiation energy and ion current density for Ta 2 O 5 films were 5 to 9 keV and 0.5μA/cm 2 , respectively. The Ta 2 O 5 /SiO 2 films deposited with O 2 -GCIB irradiation showed very uniform and dense structures without columnar or porous structures. Due to the significant surface roughness improvement effect of GCIB, the surface roughness decreased even though the films were deposited on a rough surface. The Nb 2 O 5 /SiO 2 interference filter deposited with O 2 -GCIB assisted deposition was very stable and there was no shift of wavelength before and after environmental tests. © 2003 Elsevier B.V. All rights reserved.