| 摘要 |
PROBLEM TO BE SOLVED: To easily manufacture a transparent base material covered with thin films, by providing the covering of one or more thin films on the surface of the transparent base material and allowing the covering to include at least one film A containing an aluminum fluoride or an aluminum oxide fluoride. SOLUTION: A surface of a glass base material 1 is covered with superposed components 6 consisting of four films wherein thin films 2, 4 having a high refractive index an thin films 3, 5 having a low refractive index are alternately arranged. The superposed components 6 include at least one film A containing an aluminum fluoride or an aluminum oxide fluoride Alx Oy Fz (wherein y>=0). The aluminum fluoride or the aluminum oxide fluoride can be built up in the form of a thin film by employing the cathode sputtering supported arbitrarily in a magnetic field. Further, the film A having the formula Alx Oy Fz is obtained from an aluminum target in the presence of oxygen and CF4 . Furthermore, the films 2, 3, 4 are obtained from a tin target, a doped silicon target, and a niobium target, respectively, in the presence of oxygen. |
