| 摘要 |
PROBLEM TO BE SOLVED: To provide a projection aligner in which a disposition of a length measuring sensor is facilitated and a positioning accuracy of a stag is improved. SOLUTION: The projection aligner includes a Z position length measuring mechanism 17 for measuring a height position (Z position) on a surface of a reticle or a wafer. The mechanism 17 has the length measuring sensors 19 such as three electrostatic capacity sensors or the like. The sensors 19 are disposed in such a manner that a detecting point 23 is disposed on a part out of an exposure field 21 surrounding an exposure field 21 on a wafer 13. A restriction of the sensor is eliminated by disposing a measuring position out of the exposure field, and hence the disposition is facilitated. Thus, the height of the reticle or the wafer can be accurately measured. COPYRIGHT: (C)2004,JPO
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