CONTINUOUS CVD THIN FILM FORMING DEVICE

PURPOSE:To prevent sticking of pulverized foreign matter particles onto the thin film of a wafer with a continuous CVD thin film forming device by providing a suction duct for suspended particles and a cleaning gas supply duct for air curtain in proximity to the discharge duct of said device. CONSTITUTION:The wafer 12 is placed via hot tray 11 on an endless belt 13 heated by a heater 10 and is heated and transferred in an arrow direction by the endless belt 13. A gaseous mixture composed of SiH4 and O2 is blown by clean gaseous N2 as a carrier gas onto the surface of the wafer 12 from an injector 14 consisting of many slits 21 to form the thin insulating film of SiO2 on the surface of the wafer 12 by the CVD method. The suspended particles of SiO or SiO2 are generated as the foreign matter in the outlet A of the exhaust gas duct 15 of such CVD device in the conveying direction of the wafer 12 and therefore, the gas such as air cleaned by passing the same through a filter 19 is blown from a duct 18 to form the air curtain so that the foreign matter is sucked into the suction duct 16 formed of a partition plate 17 without being released to the outside. The sticking of the foreign matter onto the insulating film on the wafer 12 and the deterioration in quality thereof are thus prevented.