Automatic holographic wafer positioning system and method

摘要: System and method for automatic alignment of workpieces such as semiconductor wafers a photomask subsequent image exposure. Alignment is based on the transparency to infrared light opaqueness thereto patterns fabricated in wafer. A holographic optical system generates Fourier transformed transmitted through wafer cross-correlates with complex spatial filter generate recognition spots having spot displacements corresponding waferfilter nonalignment. The an error signal used control position.