| 摘要 |
PURPOSE:To make the thickness of the optical film deposited by evaporation on a substrate surface uniform by regulating the disturbance in the vapor flow generated by a butterfly type shutter by means of a side plate corresponding to the shutter. CONSTITUTION:The vapor source 9 of a vacuum evaporator is positioned to face the irradiation position of an electron beam 2 by the rotation of a crucible 8 and is heated. The thickness of the optical thin film to be deposited by evaporation on a substrate 3 is controlled by the opening and closing of a shutter 5. A desired film 41 is formed on the substrate 3 by repeating the operation of closing the shutter 5 after the formation of the desired thin film, rotating the crucible 8, and depositing the next vapor source 10 or the like by evaporation superposedly thereon. Part of the vapor flow is reflected by the shutter 5 and is deposited on the substrate surface on a far side; on the other hand, the vapor flow that advances in the direction of a side plate 11 is also deposited on the substrate surface near the shutter 5 as its advance direction is changed by the plate 11; therefore, both flows are offset, and the optical thin film formed by the vapor deposition has the thin concentrical shape wherein the central part on the surface of the substrate 3 is thick and the thickness is decreased uniformly and smoothly toward four sides. |
