| 摘要 |
PURPOSE:To improve the productivity of a laser working apparatus which performs a predetermined work by applying a laser beam to the specific position of a workpiece by employing a laser source which emits a laser beam with a variable wavelength. CONSTITUTION:The shutter S of a laser source A is opened and a long wavelength laser beam L is selected and applied to a wafer 2 through a laser output controller 3, a half mirror 4 and further a beam positioner 5. At that time, a part of the laser beam L is detected by an incident luminous power detector 12 and, at the same time, the laser beam L reflected by the wafer 2 is detected by a reflected luminous power detector 13. Then an alignment controller 11 detects an alignment mark by factors such as the variation of the reflectance of the laser beam L to perform the alignment. Then, when the shutter S is closed, the shutter S2 of the source A is opened and a laser beam L2, which has a wavelength shorter than the laser beam L used for the alignment, is selected and applied. With this constitution, the improvement of the alignment accuracy and a wider work margin can be obtained simultaneously and the yield in a bit saving work can be improved. |
