Patent ID: 6490026
Filing Date: 2002-12-03
Classification: G03B,G03F

Abstract:
A method for aligning an object to be processed with a predetermined target article, said method being executed by a system which includes a pre-aligner for preliminarily positioning said object before conveying it into a processing area, and a stage for supporting said object from the underside thereof, said method comprising the following processes:a first process for conveying said object to said pre-aligner to mount it thereon, operating said pre-aligner to rotate said object in a first direction by a predetermined number of degrees with respect to a reference direction, and positioning said object in such a rotated state; a second process for conveying said object to said stage to mount it thereon and detecting positional data with respect to said object in such rotated state; a third process for again conveying said object to said pre-aligner to mount it thereon, operating said pre-aligner to rotate said object in a second direction by approximately said predetermined number of degrees with respect to the reference direction, said second direction being opposite said first direction, and positioning said object in such a rotated state; a fourth process for again conveying said object to said stage to mount it thereon and detecting further positional data with respect to said object in such a rotated state; a fifth process for calculating a positional correction factor for said object by making use of the positional data detected in the second and fourth processes; and a sixth process for finally conveying said object to said pre-aligner to mount it thereon, and operating said pre-aligner to rotate said object so that said object is directed in the reference direction.