ELECTROSTATIC DECHUCKING METHOD AND APPARATUS FOR DIELECTRIC WORKPIECE IN VACUUM PROCESSOR

摘要

PROBLEM TO BE SOLVED: To provide a new improved method and a new improved apparatus for chucking and dechucking a workpiece electrostatically in a vacuum plasma processor. SOLUTION: A glass workpiece 32 processed in a vacuum plasma processing chamber 10 is dechucked by gradually reducing the chucking voltage during processing while maintaining the voltage high enough to clamp the workpiece. The chucking voltage during processing is controlled in response to chucking force and flow rate of a heat transfer fluid flowing to the chuck. A reverse polarity voltage applied to the chuck at the end of processing assists in dechucking. The workpiece temperature is maintained at a high value at the end of processing. A peak current flowing through the chuck during workpiece lifting from the chuck controls the amplitude and/or duration of the reverse polarity voltage during the next dechucking operation. An inert plasma in the chamber 10 removes a residual charge from the workpiece 32 after workpiece lifting from the chuck 30. COPYRIGHT: (C)2010,JPO&INPIT