| 摘要 |
A laser beam is radiated from a laser source. The laser beam radiated from the laser source is converged at a converging point inside of a work member to form cracks at the converging point and in its nearby area, by making a cross section of the laser beam at the converging point have a shape long in a first direction perpendicular to an optical axis of the laser beam. Markers easy to increase contrast can be formed in the work member. <IMAGE> |
