| 摘要 |
PROBLEM TO BE SOLVED: To position a reticle and a wafer accurately for a short time by applying a flux of incident light to a photosensitive pattern which is formed on an object coated with a photoreceptor and detecting change in the flux of incident light according to signals from a light reception means so as to obtain the position information on the photosensitive pattern. SOLUTION: A light source unit 301 as a means to emit a light flux which is provided with a light source 3011 and a polarization element 3012, applies an outgoing light 305 as a flux of incident light to the surfaces of a resist and a wafer and allows it to be reflected thereon, thereby changing the phase difference and amplitude ratio of P and S polarization elements in the synthetic light flux according to double-refractive index caused by the resist pattern on a wafer 103. Then, the change in light flux is detected by a detector 3021 through a turningλ/4 plate 3024 and an analyzer 3021, and the phase difference and amplitude are obtained from the phase information including amplitude, d.c. element and sine wave, so that the position information on deviation of alignment can be obtained. |
