| 摘要 |
PROBLEM TO BE SOLVED: To prevent the metallic contamination of a substance layer deposited on a semiconductor wafer in a reactor by monitoring the flow rate of a purge gas supplied through a line and adjusting valves so that all flows of the gas can be directed to the reactor, and then, regulating the flow rate so as to reduce the amount of oxygen. SOLUTION: In order to deflect a resulted gas of reaction from a seal plate 28 and a gas ring, a purge gas is continuously made to flow through a vapor- deposition cycle. The presence of oxygen and steam in a barrel reactor is monitored and the flow rate of the purge gas in one or more of purge lines 34-40 is regulated by operating bellows weighting valves 44A-44D so that the amounts of oxygen and steam existing in the barrel reactor can be minimized. Especially, the oxygen and steam which are apt to stay in the space between the seal plate 28 and gas ring are purged by increasing the flow rate of the gas supplied through the seal plate purge gas line 40. |
