| 摘要 |
A method and apparatus for retaining or clamping a substrate 22, such as a wafer, on a surface of a substrate support structure 23 uses a liquid 64 applied to the support surface that comprises a plurality of contact elements 27. The liquid 64 is first applied to fully cover the elements (figs 7a-c) and trapped gas (62) may be allowed to escape. Then the substrate is placed onto the liquid layer (7d-e). Finally, some of the liquid 64 is withdrawn 65,67 so that the substrate rests on the plurality of contact elements and is held by means of a capillary clamping force exerted by the thin liquid layer. The wafer may be released by adding more liquid to the layer to cause the wafer to float above the contacts 27. Figures 11 a-d shows a mechanism for lowering the wafer at angle alpha, preferably between 5 and 10 degrees, between the liquid and wafer. The liquid may be water. |
