| 摘要 |
PURPOSE:To obtain high accuracy on positioning by previously forming a desired number of positioning patterns at the intersections of scribing lines shaped to a wafer when the wafer placed on a stage is positioned to projecting laser beams. CONSTITUTION:When a semiconductor wafer 1 is placed on a wafer stage 19 and positioned to laser beams from a laser light source 10, positioning patterns are formed to the wafer 1. The positioning patterns are not shaped around the wafer 1 at that time, and positioning patterns 5a, 5b consisting of a desired number of fine irregularities are formed previously to the inner surface of the wafer 1 in the intersections of longitudinal and lateral scribing lines 3 shaped to the wafer 1. According to such constitution, laser beams are projected to the wafer 1 on the stage 19 through a mask 16 on a mask stage 17, reflected beams from a half mirror 14 fitted on its midway of laser beams are received by a photoelectric conversion element 21, and several stage 17 and 19 is turned by an output from the element 21 by using driving devices 24 and 23. |
