摘要 |
A film forming apparatus includes a chamber in which a thin film is formed on a semiconductor wafer by supplying a process gas, the interior of which is then cleaned by a cleaning gas, while the gas in the chamber is exhausted by a vacuum system. The vacuum system includes a main vacuum line connected to a vacuum port of the chamber, a high-vacuum pump arranged on an upstream side of the main vacuum line, a coarse control vacuum pump arranged on a downstream side of the main vacuum line, a bypass line which is connected to the main vacuum line so as to bypass the high-vacuum pump and has a first connection portion connected between the vacuum port and the high-vacuum pump and a second connection portion connected between the high-vacuum pump and the coarse control vacuum pump, a trap arranged on the bypass line, heater arranged between the first connection portion and the trap for heating gas flowing from the first connection portion to the trap, and valves for selectively opening/closing the main vacuum line and the bypass line to allow the gas in the chamber to flow through one of the lines.
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