Nixon Peabody LLP
System and method of sensing and removing residual charge from a processed wafer
Systems and methods for removing residual charge from a processed wafer are described. Removal of residual charge eliminates de-chucking failure that may break or damage the wafer. Residual charge is removed by applying a reverse polarity discharging DC voltage to an electrode embedded in an electrostatic chuck (ESC) supporting the wafer, and providing an outlet to the residual charge to ground via a lift pin assembly. Lift pin assembly is kept at the same potential with respect to a pedestal of the ESC to avoid sparking during the application of RF power to generate plasma. A residual charge sensor is included to sense and measure the amount of residual charge, so that the parameters of the reverse polarity discharging voltage can be adjusted in a subsequent de-chucking operation.
Advanced Micro-Fabrication Equipment, Inc. Asia
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inventional inventional inventional
Tuqiang Ruoxin Ye Jinyuan Liang
Ni Du Wang Chen Ouyang