| 摘要 |
PROBLEM TO BE SOLVED: To exclude the influence of the distribution of reflectance by correcting the position information of an inspected surface obtained from a position detecting system, on the basis of the detection information from an optical characteristic detecting system. SOLUTION: A projecting optical system 140 is arranged in the optical path of light flux L2, L3 in front of an AOM 130, and a wafer W is placed in the position being conjugate to the AOM 130 with respect to the optical system 140. The two light flux L2 and L3 cause interference through the optical system 140 on the wafer W and form fringes of alternate line and space bands. Further, an imaging optical system 150 is arranged on the opposite side of the projecting optical system 140 with regard to the optical axis of a projecting optical system PL, and an array sensor 170 is arranged in the position being conjugate to the wafer W with regard to the optical system 150. The image of the frings on the surface of the wafer W is formed on the sensor 170. The lateral dislocation of fringes is measured from the information by means of the array sensor 170, and the position of the wafer in the vertical direction is measured. |
