| 摘要 |
<p>PURPOSE:To eliminate the effects of interference of the thin film on a photosensitive substrate when the image of alignment mark on the photosensitive substrate is detected through the intermediary of a projection optical system having color aberration. CONSTITUTION:An alignment light of the prescribed wave range is grown by having the light emitted from a light source 10 passes through a dichroic filler 8, and the alignment light is made to irradiate on the wafer mark WM on the wafer W through the intermediary of a projection optical system 1. The alignment light reflected from the wafer mark WM is received by an objective lens, optical axis is inclined, through the intermediary of the projection optical system 1, and the wafer mark WM is image-formed by the light sent from the objective lens 2 on the detection surface of a detection element 5 through the intermediary of a cylindrical lens 3 and an image-forming lens 4. The difference between a magnification color aberration and an on-axis color abberation is converted to the on-axis color abberration by the inclination of optical axis, the on-axis color abberation is corrected by the objective lens 2, and the image- formation surface R1 and the detection surface of the detection element 5 are arranged in a nonparallel relation.</p> |
