| 摘要 |
PURPOSE:To obtain prescribed film thickness with high accuracy in controlling of the optical film thickness of vapor deposited thin films by passing monochromatic light through the thin films during vapor deposition of the thin films and measuring the inverse proportional value of transmittance. CONSTITUTION:An evaporating source material 3 placed on the inner side of an opening/closing device 2 is heated in a vacuum vessel 1. Monochromatic light is projected from a light projector 6 to the substrate 5 to be deposited in a circular cover 4 and the light passed through the substrate 5 is fed to a measuring mechanism 7. The incident light in the mechanism 7 is passed through a photodetecting part 8 and is intensified with an amplifier 9. The ratio between the amplitude which is the inverse number of the transmittance of the monochromatic incident light and the constant amplitude determined by the refractive index of the evaporating source material is determined with constant power sources 10, 10' and calculators 11, 11', then the outputs which are equal to the square of the sine of optical phase angles and change periodically with an increase in optical film thickness are drawn by a recorder 12. The vapor deposition is suspended by the device 2 upon attaining of the required optical film thickness, whereby the thin films are formed to the prescribed film thickness with high accuracy. |
