| 摘要 |
PURPOSE:To remove crystal of sublimable substance stuck on a laser light transmitting window and to effectively perform irradiation of laser light by providing a heating means to the laser light transmitting window in a vapor growth apparatus (chemical vapor deposition) wherein the sublimable substance is made to a material. CONSTITUTION:A photomask 1 provided to a reaction vessel 2 is positioned so that a laser light 11 can be irradiated on the chipped defective positions of the photomask 1 through a transmitting window 7 by means of a lens 10. Sublimable bis(benzene) chromium (BBC) 4 is heated with a heater 3 and sublimated as a raw material of chemical vapor deposition gas for Cr deposition which is a pattern material of the photomask 1 and introduced into the inside of the reaction vessel 2 through a valve 5 and a Cr film is deposited in the chipped defective positions by pyrolytically decomposing BBC. In this case, sublimated crystal of BBC is stuck on the inside of the cooled transmitting window 7 and thereby the transmittance of laser light is reduced. The crystal of BBC stuck on the transmitting window 7 is sublimated and removed by heating the transmitting window 7 with a heating wire, heated air or an infrared lamp or providing a coating which heats the window by absorbing slightly laser light to the transmitting window in order to prevent it. |
