| 摘要 |
PURPOSE:To continuously obtain a thin film having any desired thickness in a CVD method employing an ultraviolet ray, by preventing the deposition of a semiconductor film which prevents the transmission of light on a light-introducing window. CONSTITUTION:A low-pressure mercury lamp 5 is placed at the focal point of a reflecting mirror 8 so as to project an ultraviolet ray 6 into a reflection chamber 2 through a quartz window 4 located at the focal point of a cylindrical lens 7. A pulse beam 10 is emitted from an Nd:YAG laser 9 to irradiate the window 4. The laser beam is oscillated with a selected energy per pulse, beam diameter and repetition frequency. A material gas 3 employed is silane mixed with Hg. According to this constitution, the rise in temperature of the window by the irradiation with the laser beam is suppressed, and any Si deposition is melted and evaporated to prevent the lowering in transmittance of the ultraviolet ray. In addition, the laser beam conditions are selected such that silane is photochemically decomposed. Accordingly, an Si thin film having any desired thickness can be continuously deposited on a substrate 1. |
