| 摘要 |
PURPOSE:To easily obtain the best focus images of each wavelength at the same position on the occasion of detecting the positioning marks on a material to be developed using a plurality of single color lights in different wavelengths by inserting a color aberration compensation lens into the light path between a projection lens and detector. CONSTITUTION:As the positioning mark focused through the compensation lenses 68, 70, an image of e-line indicated by a solid line and an image of d-line indicated by a broken line, for example, are focused on the same position, namely on a detection slit 20. The light focusing the positioning mark on this detection slit 20 is paralleled by the collimeters 64, 66, and focues again on the slits 60, 62 and then detected by the pattern detectors 56, 58. The X, Y coordinates of the positioning marks 12X, 12Y on a semiconductor wafer 10 are obtained by a laser measuring length part 32. The coordinates X, Y of the positioning marks 12X, 12Y are obtained for two chips on the semiconductor wafer 10, relative error between semiconductor wafer 10 reticle 16 is detected and such relative error is compensated by controlling a movable part 26. |
