| 摘要 |
An apparatus for controlling wafer temperature in a plasma etcher during a plasma-on state and a method for using such apparatus are disclosed. In the apparatus, an additional temperature sensor for sensing the wafer backside temperature and a second flow control valve of a mass flow controller are utilized such that the second flow control valve may be opened to increase the flow of cooling gas through the wafer backside when a temperature rise is detected by the temperature sensor. When the wafer temperature detected is too high, i.e., higher than 65° C., the second flow control valve is opened to increase the flow of helium cooling gas from a nominal rate of 13 sccm by at least 50%. When the temperature of the wafer detected is below 65° C., the flow of the helium cooling gas can be reduced by closing the second flow control valve.
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