AVS 49th International Symposium
    Thin Films Monday Sessions
       Session TF-MoM

Paper TF-MoM6
Optical Thin Film Formation by Oxygen Gas Cluster Ion Beam Assisted Depositions

Monday, November 4, 2002, 10:00 am, Room C-101

Session: Optical Thin Films
Presenter: N. Toyoda, Himeji Institute of Technology, Japan
Authors: N. Toyoda, Himeji Institute of Technology, Japan
I. Yamada, Himeji Institute of Technology, Japan
Correspondent: Click to Email
High-quality Ta@sub 2@O@sub 5@/SiO@sub 2@ and Nb@sub 2@O@sub 5@/SiO@sub 2@ were deposited with oxygen gas cluster ion assisted deposition at low-temperature for optical filters. As one cluster ion has thousands of O@sub 2@ molecules, equivalently low-energy ion irradiations are realized at several keV of total acceleration energy. Due to the dense energy deposition of cluster ions, high-temperature and high-pressure conditions are realized at the impacted area, which enables to deposit high quality thin films without heating the substrate. Also, GCIB shows significant surface smoothing effects, which realizes very flat surface and interfaces for multi-layered structures. In this study, O@sub 2@-GCIB was applied to form high quality optical films. With gas cluster ion assisted deposition, high refractive index and very smooth surface of Ta@sub 2@O@sub 5@ films were deposited. The optimum cluster ion energy and cluster ion current density for Ta@sub 2@O@sub 5@ films were found to be 7keV and 0.5uA/cm@super 2@, respectively. The structure of film was very uniform and no porous or columnar structures were observed. The surface or interfaces of Ta@sub 2@O@sub 5@/SiO@sub 2@ films were also very flat by surface smoothing effect of cluster ion beams. Very smooth surface can be realized even though the bottom surface was rough. There was no wavelength shift of filters after environmental tests, which indicates that dense oxide films were formed at low-temperature with O@sub 2@ cluster ion assisted deposition.