| 摘要 |
PURPOSE:To prevent dispersion of a formed film thickness by a method wherein the time taken to form film is controlled by comparing light intensity before incidence to a reaction vessel with respective light intensity passing through the reaction vessel before or after light absorption raw gas is introduced to the reaction vessel. CONSTITUTION:Laser beam 2 injected from light source 1 comes into a reaction vessel 3 from an irradiation aperture 4 installed to the reaction vessel 3, then gets out again through an irradiation aperture 5. The laser beam intensity before incidence to the vessel 3 is detected by an optical sensor 7 through a mirror 6 and the laser beam intensity injected from the vessel 3 detected by an optical sensor 8, then both said intensities are compared. Fixed quantity of raw gas is supplied to the vessel 3 from an intake vent 9 and is evacuated from an exhaust vent 10. The detective signal of the optical sensors 7, 8 are introduced to a forming film time setting device 14 and said device 14 controls generation time of the laser light source 1. Thereby, film thickness control can be performed easily and dispersion of film thickness can be decreased. |
