| 摘要 |
PURPOSE:To prevent the cloudiness of a window for light transmission when the light is irradiated by providing a reaction tube of double tube structure consisting of an outer tube which has the window which can be transmitted by the light at part of a tube wall and a straight inner tube inserted in the outer tube having a hole which can be passed by the light at part of the tube wall. CONSTITUTION:An excimer laser 9 is irradiated perpendicularly on the surface of a GaAs substrate transmitted via a window 2. Trimethylgallium and arsine, raw material gases, are optically decomposed by the light of wavelength 193nm and metal gallium or metal arsenic is deposited. The raw material gas, however, is not leaked via a hole 4 for light transmission from the inside of an inner tube 3, no raw material gas exists near the window 2 so the window 2 is not clouded by the deposition of the metal gallium or the metal arsenic. The inner tube 3 in front and in the rear of a susceptor has a straight structure and the raw material gas flows in layers so the raw material gas required for the manu facture of a very thin film can be changed rapidly.
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