ARTICLE COATED WITH OPTICAL MULTILAYERED FILM

摘要

PURPOSE:To coat a large-area base body with films by DC sputtering to a uniform film thickness by using the silicate of aluminum to form layers consisting of a low-refractive index material and using a metal oxide which has a specific refractive index in a visible region to form layers consisting of a high-refractive index material. CONSTITUTION:The layers 2 consisting of the silicate of the aluminum which form the optical multilayered films have the refractive index as low as 1.54 to 1.62 and, therefore, the layers exhibit a light interference effect as the layers of the low refractive index to impart optical functions to the transparent base body 3 when these layers are laminated with the layers 1 consisting of the high-refractive index material having >=2.0 refractive index. The silicide target of the aluminum decreases the formation of an electric layer by oxidation of the surface and maintains the target surface at an electrical conductivity at the time of coating the silicate film of the aluminum by DC sputtering in the reduced pressure atmosphere contg. oxygen. The base body 3 of the large area is coated with the films 2 consisting of the silicate of the aluminum stably over a long period of time by the DC sputtering in this way.