| 摘要 |
PROBLEM TO BE SOLVED: To provide a laser irradiation device capable of suppressing deterioration of focus accuracy that is caused by position deviation between a measurement position recognized by a system controller and an actually measured position.SOLUTION: A surface height measuring apparatus is relatively moved along a measurement line set on the surface of an object to be processed and is moved in a reverse direction on an adjacent measurement line to actually measure the surface height of the object to be processed before laser irradiation, and the actually measured surface height is memorized. A plurality of actually measured surface heights in the vicinity of a laser irradiation position are read out, and the surface height of the laser irradiation position is calculated based on a plurality of these actually measured surface heights. Actually measured surface heights on a plurality of measurement lines near the laser irradiation position are included in a plurality of the actually measured surface heights. On measurement lines adjacent to each other, position deviation between the measurement position recognized by the system controller and the actually measured position is reversed. Since the surface of the object to be processed can be considered a plane, if the position deviation is reversed, errors caused by position deviation is offset when calculating the surface height. Thereby, deterioration of focus accuracy can be suppressed. |
