Excimer Laser Micro-texturing on Silicon Wafer Using Mask Projection Technique

In the current study, an attempt has been made to study the use of KrF excimer laser to fabricate micro-pillars (50 µm × 50 µm) over a large area on a silicon wafer surface. A parametric study has been performed to optimize the processing parameters such as pulse energy (400 mJ–600 mJ) and the number of pulses (260–300) for obtaining the desired machined feature. The ablation performance was reported better at pulse energy 600 mJ with 300 pulses at a predetermined frequency of 30 Hz. A numerical study using COMSOL Multiphysics software was also performed to understand the ablation process of silicon with a nanosecond laser, and the obtained result was compared with the experimental result, which was found to be in agreement with each other. Furthermore, a thorough study on mask profile was carried out to achieve the final feature on Si wafer in minimum machining time.