| 摘要 |
PURPOSE:To remove the biting of dust between a substrate and a base plane, to reduce the lowering of resolution due to reflection from the base plane and to facilitate cleaning by forming a large number of spheres, a base supporting the spheres and a vacuum sealing member and a vacuum suction port around the base to a substrate suction base. CONSTITUTION:The upper ends of a large number of steel balls 27 arranged onto a base 22 are bonded onto the base 22 with adhesives 28 having the high absorptivity of beams so as to be precisely brought into contact with a plane 23, a vacuum suction port 24 is communicated with spaces around the balls 27 by vertical holes 30, and the flatness of the plane 23 constituted of the steel balls 27 and the upper surface of a vacuum sealing member 29 extends over 1mum or less. When a substrate 21 is placed onto the plane 23 and the vacuum suction port 24 is sucked by a vacuum pump, the substrate 21 is pushed by atmospheric pressure and pressed onto the plane 23, and the inflow of air from the periphery of the substrate is removed approximately. Accordingly, the probability of biting of dust is reduced, the deterioration of resolution due to reflected beams from a substrate suction base is diminished, and cleaning is also facilitated. |
