Apparatus and method for controlling wafer temperature

摘要

An apparatus and method which is particularly suitable for maintaining a wafer at an optimum temperature for the alignment and exposure step during photolithography. The apparatus includes a cooling plate having at least one cooling channel. A coolant is continually circulated through the cooling channel to cool the cooling plate and the wafer resting thereon prior to transfer of the wafer to a wafer stage in a stepper, for example. The cooling plate may be mounted on an OF table inside the stepper and include a central opening for receiving the wafer-engaging shaft of the OF table. The cooling plate maintains all regions of the wafer at substantially the same temperature as the wafer stage in the stepper prior to transfer of the wafer to the wafer stage.