| 摘要 |
PROBLEM TO BE SOLVED: To detect the alignment offset between first and second marks formed on a substrate by generating interference fringes, the amplitude distribution of which has a prescribed period in the detecting direction, and, at the same time, relatively scanning the fringes and a positional deviation detecting mark in the detecting direction. SOLUTION: A registration measuring instrument 100 is provided with a wafer table 10 which moves in two-dimensional directions X-Y while the table 10 holds a substrate composed of a wafer 7 and lighting optical systems 1-6 which cause interference fringes by projecting a pair of coherent beams Lm and Lp upon a registration measuring mark which is formed on the wafer 7 as an alignment offset detecting mark at a prescribed angles. The instrument 100 is also provided with light receiving optical systems 6, 5, and 15-17 which receive diffracted light and perform photoelectric conversion on the light when the beams Lm and Lp are made incident to the systems 6, 5, and 15-17 and a main controller 18 which calculates the alignment offset of first and second marks constituting the registration measuring mark in the detecting direction based on photoelectric signals and a prescribed reference signal from the light receiving optical systems 6, 5, and 15-17. |
