| 摘要 |
This invention relates to electrostatic clamping and associated clamps. A particular method is described of clamping a wafer, during the process that creates asymmetric stress in the wafer, to an electrostatic chuck having a concave portion in its clamping surface characterized in that the wafer is initially clamped around its periphery in a generally flat orientation and then is bowed into the concavity as the asymmetric stress is created in the wafer. It is particularly preferred that the degree of concavity of the chuck is such as to maintain a gas seal between the wafer and the chuck sufficient to allow backside cooling of the water.
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