| 摘要 |
PURPOSE: A backside gas supply system in a plasma treater is provided to check whether or not gas is stably supplied by detecting flow rate of gas exhausted and improve uniformity of wafer treating process by stopping backside gas supply system in case of unstable gas supply. CONSTITUTION: A backside gas supply system in a plasma treater comprises a gas supply conduit (235) which is connected to a gas supply source (230), and connected to a plurality of gas supply holes (225) for guiding the gas to lower part of a wafer (210), a unit pressure controller (240) which is arranged on the gas supply conduit (235) for controlling flow rate, a first manometer (250) which is installed on the gas supply conduit (235) for measuring flow rate of gas supplied, an exhaust gas conduit (270) which is divided from the gas supply conduit (235), and through which exhaust gas is exhausted, a pump (P) which is connected to the exhaust gas conduit (270) for sucking in gas, a second and a third manometers (272,274) which are installed in the exhaust gas conduit (270) for measuring flow rate of exhaust gas, and a controller (260) which sends feedback signal to the unit pressure controller (240) by calculating pressure difference from values measured from the exhaust gas conduit (270) and the second and third manometers (272,274).
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