LASER BEAM MACHINE

摘要

PROBLEM TO BE SOLVED: To make it possible to easily and rapidly remove by optical abration a thin film formed on the alignment mark by projecting the laser beam emitted form laser beam source through the irradiation optical system. SOLUTION: The laser beam of <=400nm wave length emitted from a laser beam source 2, after adjusted its light quantity by a light quantity controlling part 3, is adjusted a numerical aperture by a variable aperture diaphragm 4. The laser beam, transmitted through the variable aperture diaphragm 4, is reflected by a dichroic mirror 5 and made incident to an irradiation lense system 8. The irradiation lense system 8 converges the incident laser beam on a fixed region of a wafer 9. Resultantly, a polyimide film on an alignment mark of the wafer 9 is removed by the optical abration effect.