| 摘要 |
PURPOSE:To detect a position of an alignment mark highly accurately while unnecessary noise light is eliminated by correcting an adjustable allowance based on an uneven shape on a resist surface in the vicinity of the alignment mark on a wafer surface by using Moire fringes obtained by two grating patterns different in pitch. CONSTITUTION:Grating patterns G1, G2 different in pitch from each other in a conjugation relation with a wafer W through an optical system are arranged so that their grating directions coincide with an alignment direction, while the pattern G1 is illuminated by a lighting system. Accordingly a light flux from the pattern G1 is incident to an alignment mark face Wa on the wafer surface perpendicularly to the wafer W surface on a plane parallel to a grating direction of the pattern G1 and slantly with a predetermined angle in a plane perpendicular to the grating direction of the pattern G1 to form an image of the pattern G1. The image is projected onto the pattern G2 surface, a signal from an image sensing device 110 is used to calculate a surface of a resist on the alignment mark Wa region by an arithmetic means and relative alignment of the wafer W and the image sending device 110 is performed. |
