| 摘要 |
<p>PROBLEM TO BE SOLVED: To surely hold by vacuum suction even a substrate having a warp larger than a prescribed value for vacuum suction. SOLUTION: A substrate chuck 1 comprises a disc-like chuck body 2, a ring-like outer rim 4 provided along the outer circumference of the chuck body 2, a ring-like inner rim 3 provided on the inside of the outer rim 4, a vacuum passage 6 for evacuating the chuck body 2 and an inner enclosed space 7, and orifices 51-54 connecting the inner enclosed space 7 and an outer enclosed space 8. When air is sucked from the vacuum passage 6, the inner rim 3 touches an wafer substrate 31 to form the inner enclosed space 7 which is evacuated. Subsequently, air is sucked from the outer enclosed space 8 through the orifices 51-54 and the outer rim 4 touches the wafer substrate 31 which is thereby sucked to the chuck body 2.</p> |
