AVS 50th International Symposium
    Thin Films Wednesday Sessions
       Session TF-WeM

Paper TF-WeM2
Smooth Optical Thin Film Formation by Oxygen Cluster Ion Beam Assisted Depositions

Wednesday, November 5, 2003, 8:40 am, Room 329

Session: Optical Thin Films and Photovoltaics I
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
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 uniform amorphous structures were observed with cross-sectional SEM. 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. Even though the deposited surface was rough (average roughness 1.5nm), the surface roughness of the deposited Ta@sub 2@O@sub 5@ film was improved to 0.7nm. As there is strong surface smoothing effect with O@sub 2@ cluster ion beam assisted deposition at low substrate temperature, it is appropriate to form multi-layered optical filters.