JPH0612754B

PURPOSE:To contrive to enhance stabilization and precision of positioning of a wafer and a mask at a projection exposure device by a method wherein a beam splitter, a continuous spectrum light source, a chromatic aberration compensating lens, and a pattern detection unit are provided to an exposure optical system using monochromatic light. CONSTITUTION:White light emitted from a pattern detecting light source 20 for positioning is projected to a wafer 12 through a half mirror 19, a dichroic mirror 17, and a projective lens 16, passed through the reverse travel, chromatic aberration is corrected according to lenses 18, and a pattern on the wafer is recognized according to a detection unit 21. The transferring mechanism 14 of a table 13 is controlled 22 conforming to recognition, and the wafer and a mask 11 are positioned. Then the mask 11 is illuminated according to a monochromatic exposure light source 15, and a mask pattern is projected on the wafer according to the lenses 16 utilizing reflection of a mirror 17. Because white light is used when positioning is performed, unstability of detection according to the interference of a resist thin film on the wafer is checked, pattern detection attaching importance to an optic axis (attaching importance to a chip) can be also attained, and precision of positioning is enhanced. Moreover, because the lenses 16, 18 are arranged on the optical axis, precision of pattern detection is elevated.