| 摘要 |
PURPOSE: A wafer stage chuck is provided to prevent local defocus due to contamination and obtain uniform flatness on all regions of a stage by forming a vacuum absorption layer on a wafer loading surface. CONSTITUTION: A wafer stage chuck(50) is formed with a stage shaft(54) and a stage. The stage(52) is supported by the stage chuck(54). The stage(52) is used for supporting a loaded wafer. A stepped portion is formed between a circumference and an inside of the circumference of the stage(52). The stepped portion is about 2 to 3mm. A surface of the inside of the circumference is lower than the surface of the circumference. A vacuum absorption layer(56) is formed on the circumference in order to prevent separation of the wafer from the wafer stage chuck(50). Accordingly, the wafer is not contacted with the surface of the inside of the circumference whereas the wafer is contacted with the surface of the circumference.
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