| 摘要 |
Electrostatic wafer chucks are disclosed for use in holding a substrate (e.g., semiconductor wafer) during processing of the substrate in a vacuum chamber or other reduced-pressure environment. A representative wafer chuck provides improved control of the vacuum level in the vacuum environment while providing a mechanism (lift pins) for raising and lowering the substrate relative to the chuck. 1. The chuck body defines a wafer-mounting surface that contacts the under-surface of the substrate. The chuck body defines a gap between the under-surface of the substrate and the chuck for conducting a heat-transfer gas, and multiple feed-through holes extending through the chuck body. Surrounding each feed-through hole is at least a first protrusion configured to separate the respective feed-through hole from the gap. A respective lift pin in each feed-through hole extends from the chuck body across the gap to the under-surface of the substrate. The lift pins can move relative to the chuck body to lift the substrate relative to the wafer-mounting surface. The protrusions surrounding the feed-through holes prevent passage of heat-transfer gas through the feed-through holes.
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