| 摘要 |
PURPOSE:To prevent a reacting velocity from decreasing by mounting a light guide tube having a light transmitting window at the end on a vacuum reaction vessel, and allowing inert gas to flow from the vicinity of the window into the tube, thereby completely preventing the fog of the window. CONSTITUTION:A light guide tube 8 is mounted on the upper position of a substrate 5 in a vacuum reaction vessel 1. A window 12 of a light transmitting plate (e.g., a melted quartz plate) is provided at the end of the tube 8, and an inert gas guide tube 9 is mounted near the window 2. Reaction gas flows from the tube 3 into the vessel 1 at depositing time, and inert gas simultaneously flows from the tube 9 through the tube 8 to the vessel 1 to stop invading reactive product into the tube 8 due to the flow of the inert gas, thereby eliminating the adherence (accumulation) of the product on the window 2. |
