| 摘要 |
PROBLEM TO BE SOLVED: To form an optical thin film of relatively uniform thickness using evaporation sources as small in number as possible in forming an optical thin film on a substrate having a curved surface. SOLUTION: Each substrate 18 is supported by a substrate holder 16 opposite to evaporation sources 12a and 12b arranged on a bottom part of a vacuum chamber 10. The substrate holder is rotatable around a first axis Ca passing through a center of the substrate holder, and each substrate is revolved in the plane orthogonal to the first axis around the first axis. Each substrate is rotatable around a second axis Cb parallel to the first axis and passing through the center of each substrate. A throttling plate 14 is provided between the substrate and the evaporation sources, and provided with openings 20a and 20b to control the angle in the diffusion direction of evaporated particles 22. One opening is circular, while the other is of the shape in which two circles are connected by one rectangle. The angle in the diffusion direction of the evaporated particles to be diffused from a specified evaporation source is controlled so that the distribution 26 of the evaporated particles in the plane including the locus 24 of revolution of the substrate is lapped on the locus of revolution at two positions 30a and 30b separate from each other. |
