| 摘要 |
PURPOSE:To provide the inflow of the outside air in a carry-in-out process by mounting a detachable external reaction tube and an internal reaction tube carried into and carried out of the external reaction tube together with a wafer boat to a furnace body and supplying the internal reaction tube with an inert gas. CONSTITUTION:An outlflow hole 45 is closed, and an internal reaction tube 18 is supplied with an inert gas. Air in the internal reaction tube 18 is pushed out to the outside from a lower-end opening 19 by the difference of specific gravity with the supply of the gas, and wafers 20 in the internal reaction tube are isolated from air at the time when the gas is filled. The gas is supplied again during lowering into an external reaction tube 16 together with a wafer boat 22 of the internal reaction tube 18 filled with the gas, and the excessively fed gas flows out into the external reaction tube from the lower-end opening 19 for the internal reaction tube. The gas flowing out to the outside from an upper-end opening 15 forms a kind of a gas shower, and prevents the inflow of air to the external reaction tube 16.
|
