摘要 |
Wafer chucks and related substrate-holding devices are disclosed for use in holding the substrate while any of various processes are being performed on the substrate. For example, the devices are useful for holding a semiconductor wafer during microlithography performed on the wafer, especially in a vacuum environment. The wafer chucks can include devices for confirming that the substrate is adhered completely and properly to the "adhesion surface" of the wafer chuck before commencing flow of a heat-transfer gas to the wafer chuck. Such status-confirming devices can be, e.g., height gauges or electrical contacts that measure an electrical property that changes with changes in contact pressure of the contacts against the substrate. The wafer chucks can include devices that compensate for faulty adhesion of the substrate to the wafer chuck, such as devices that change pressures in ducts that supply and remove heat-transfer gas from a channel(s) located in the adhesion surface of the wafer chuck, so as to compensate for increased leak rates of heat-transfer gas into the environment surrounding the wafer chuck.
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