Patent ID: 6285439
Filing Date: 2001-09-04
Classification: G03F

Abstract:
A position detecting method comprising the steps of:disposing a member with an exposure surface to be exposed and an exposure mask in proximity with each other, with a gap being set between the exposure surface and the exposure mask, the member having an alignment mark formed on the exposure surface, the alignment mark having edges or apexes for scattering incident light, the exposure mask having a mask mark formed on a surface thereof, the mask mark having edges or apexes for scattering incident light; anddetecting a relative position of the member and the exposure mask by applying illumination light to the edges or apexes of the alignment and mask marks, by focussing light scattered from the alignment and mask marks on a light reception plane, and by observing images on the light reception plane, whereby a light flux scattered from one of the alignment and mask marks is attenuated or light fluxes scattered from both of the alignment and mask marks are attenuated differently, so that a light intensity of an image formed by the light flux scattered from the alignment mark and focussed on the light reception plane becomes near to a light intensity of an image formed by the light flux scattered from the mask mark and focussed on the light reception plane.