| 摘要 |
PURPOSE:To reduce the variation in displacement caused by the influence coming from outside as well as to suppress the irregularity in thickness by a method wherein, when an insulating film or an epitaxial layer is going to be formed by performing a vapor-phase growing method, the amount of evacuation of air coming out from one end of a furnace core tube is automatically controlled at a constant volume. CONSTITUTION:A sensor 11 to be used for detection of displacement is attached to an exhaust duct 8', and the sensor 11 is connected to a controller 12. The controller 12 feeds back to a driving part 13 the signal corresponding to the component of deviation between the set value and the value detected by the sensor 11, and the displacement is maintained constantly by automatically regulating the damper 7'. Accordingly, the displacement of the duct 8' can be maintained constantly for the variation of exhaust condition of the main duct 14 caused by the other ducts 15 and 16. As a result, the thickness of the film to be grown on a semiconductor substrate can be maintained constantly. |
