| 摘要 |
<p>PURPOSE:To identify and correct minute defects and foreign objects highly efficiently, by emitting the light which is directed to a substrate on which a pattern is formed, and utilizing the signal obtained by sensing the light reflected from the illuminated portion. CONSTITUTION:A light source 4 emits a low-power beam 3 from the side of a Cr film, against the photomask on a substrate 1 on which a pattern 2 comprising a Cr film is formed. A light source 6 is arranged to emit a correcting laser beam 5 to the same position illuminated by the beam 3 at the back side of the substrate 1. Photosensors 7 are arranged at the vicinity of the beam 3 so that they are directed toward the illuminated portion. The outputs of the photosensors 7 control 8 the operation of the light source 6 for the correcting laser. If the beam 3 illuminates a defect 9, the output of an OR gate OG is a zero. If a foreign object 10 is illuminated, scattered lights enter the photosensor 7, and the output of the gate OG becomes a 1. Thus, the defects and foreign objects can be identified, the light source 6 is operated depending on the output of the OR gate, thereby the defects are automatically corrected and the number of the foreign objects can be counted.</p> |
