| 摘要 |
PROBLEM TO BE SOLVED: To provide a wafer alignment apparatus having reduced tilt sensitivity related to tilt of optical markers on a wafer. SOLUTION: A substrate alignment system comprises a light source generating incoming light beams IB and IB2, which fall on a substrate composed of gratings positioned so as to generate at least one diffraction order, and optical equipment 1 which forms an image according to at least one diffraction order with a sensor device DET. The system is equipped with an aperture means TA, having apertures PH1 and PH2 at predetermined positions to pass structure-diffracted beams DB1 and DB2, the structure-diffracted beams DB1 and DB2 have diffracted beam diameters BD1 and BD2 on the faces of the apertures PH1 and PH2, respectively; and the diffracted beam diameters BD1 and BD2 are greater than the diameters of the apertures PH1 and PH2, respectively. COPYRIGHT: (C)2004,JPO&NCIPI |
