Optical thin film formation by oxygen cluster ion beam assisted depositions

O2 gas cluster ion beam (O2-GCIB) assisted depositions were employed to deposit high quality dielectric films (Ta2O5, Nb2O5 and SiO2). The optimum irradiation energy and ion current density for Ta2O5 films were 5 to 9 keVand 0.5 mA/cm2, respectively. The Ta2O5/SiO2 films deposited with O2-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 Nb2O5/SiO2 interference filter deposited with O2-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