Patent ID: 6049373
Filing Date: 2000-04-11
Classification: G03F

Abstract:
A position detection method comprising the steps of:disposing a wafer having an exposure surface and an exposure mask, with a gap being set between the exposure surface and the exposure mask, the wafer having a wafer mark formed on the exposure surface, the wafer mark having edges for scattering incident light, each edge having a curved portion whose image vertically projected upon a plane in parallel to the exposure surface has a curved shape, the exposure mask having a mask mark formed on a surface thereof, the mask mark having edges for scattering incident light, each edge having a curved portion whose image vertically projected upon a plane in parallel to the surface of the exposure mask has a curved shape; anddetecting a relative position of the wafer and the exposure mask by applying illumination light to the curved portions of the edges of the wafer and mask marks and by observing, along a direction oblique to the exposure surface, light scattered from the curved portions.