Patent ID: 8211802

Claim:
A method of cleaning an apparatus that is used in a semiconductor device manufacturing process, comprising: introducing a substrate into a reaction tube: processing the substrate by supplying a plurality of reaction gases to the reaction tube through a plurality of holes provided at a nozzle extending in a longitudinal direction of the reaction tube; transferring the processed substrate out of the reaction tube; setting a pressure in the reaction tube to a base pressure; thereafter increasing the pressure in the reaction tube by supplying cleaning gas at a first flow rate through the plurality of holes with exhaustion of the reaction tube being substantially stopped; thereafter containing the cleaning gas in the reaction tube by supplying the cleaning gas at a second flow rate that is smaller than the first flow rate through the plurality of holes with the exhaustion of the reaction tube being substantially stopped; thereafter exhausting the reaction tube with the supply of the cleaning gas being stopped, wherein after repeating at least two cycles of the introducing, the processing and the transferring, at least two cycles of the setting, the increasing, the containing and the exhausting are repeated to remove reaction by-product deposited in the reaction tube.