| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a simple dust detecting system for a semiconductor aligner, which can detect presence or absence of dust on a substrate holding means or a substrate and detect a dust presence position and can localizedly clean the aligner on the basis of its detected result. SOLUTION: Such a flat plate made of having a predetermined flatness and allowing light permission therethrough as an optical flat 1 is contacted with a substrate holding means 2, so that a laser beam oscillated and emitted in and from a laser light source 4 is illuminated toward the substrate holding means 2. When a dust 3 is deposited on the substrate holding means 2, this causes generation of a gap between the optical flat 1 and substrate holding means 2, whereby an operator can observe interference fringes. The interference fringes are detected by a photoelectric converting element 6, displayed on a monitor 7, and processed by an image processor 8 to thereby judge a dust presence position. On the basis of its detected result, a dust removing means is moved to the dust presence position to clean the position localizedly and positively.</p> |
