| 摘要 |
PURPOSE:To make an alignment with high precision feasible by a method wherein bar marks are arranged on at least three corresponding positions on two surfaces while the relative positions of bar marks on the corresponding positions of respective surfaces are optically detected to make the alignment by means of moving one surface according to the results of detection. CONSTITUTION:An inspection optical system 15 arranged over an alignment mark projects the light of a light source 12 on an object lens 14 through a halfmirror 13 to irradiate a mask alignment mark 3 under a mask 1 and a wafer alignment mark 6 on a wafer 2 from the object lens 14. The reflected light of said light is projected on a CCD 9 above-positioned with the bars of alignment marks 3, 6 arranged perpendicular to the scanning direction through the intermediary of the object lens 14 and the halfmirror 13 to detect the alignment marks 3, 6. Then the time interval omega1 between the wave form centers of detection signals 16 of mask alignment mark 3 and the other detection signals 17 of wafer alignment mark 6 or the distance between corresponding marks are measured. Finally the alignment is made by means of moving at least one of these two marks according to the results of measurement. |
