Processing study of laser marking on Si wafer

In order to identify and trace the single silicon wafer, which improved quality control and assists in process improvement, laser marking of silicon wafers had been an industrial standard in semiconductor industry. The traditional laser making had the depth 5-20um and a significant amount of debris. In this paper, the topography quality and the depth the size of the dot were investigated by adjusting laser pulse energy, laser pulse numbers . The results showed that the depth of the dot increases proportionally with laser irradiation energy while there were significant differences in the topography of the dot with different interaction time of laser irradiation. A free-debris laser dot marking process with the depth less than 2um, the height of bump less than 0.6um, the range of diameter of dots from 20um to 100um was achieved.