| 摘要 |
PROBLEM TO BE SOLVED: To smoothly use an optical thin film for a plastic lens, etc., without requiring high temperature treatment by forming the magnesium oxide fluoride based optical thin film on a plastic base material with spattering instead of heating the base material. SOLUTION: A magnesium oxide fluoride based optical thin film is formed on a plastic base material with spattering instead of heating the base material. As the optical thin film has a molecular refraction changed (a bond angle reduced), the change of a molecular volume due to oxygen ions during spattering is restricted, thus to provide the refraction factor equivalent to that of a MGF2 vapor deposition thin film. If Si concentration in the thin film is low, the rate of SiOx is lower than that if the Si concentration is too high and the bonding rate of Si-F2 becomes high, so that the Si concentration in inorganic compound can be preferably 3-10 wt.% to improve the standing stability of optical characteristics of the optical thin film. |
