High-speed and crack-free micromachining with GHz-burst femtosecond laser of fused silica and silicon carbide

Femtosecond laser micromachining with GHz-burst has rapidly emerged as a transformative method for precisely drilling and cutting transparent materials and various substrates used in semiconductor manufacturing. It combines sub-micron resolution with reduced thermal damage, enabling controlled energy delivery and improved material response. In this work, we demonstrate the optimisation of laser dicing and percussion drilling processes without post-processing steps to produce high-quality, crack-free vias in fused silica and free form dicing in 4H silicon carbide (SiC) using a new compact femtosecond laser platform with GHz FULL modulation, intra-burst repetition rates, customizable burst shaping, and real-time control over burst parameters, crucial for adapting to diverse material properties used in industry. Our experimental results confirm that precise GHz-burst control enables crack-free, reproducible holes with excellent dimensional accuracy and increased drilling throughput (60 ms/hole in 1 mm glass and below 10 ms/hole in 500 μm-thick SiC wafer). Moreover, the GHz-burst allows precise and reproducible free-form SiC dicing at a scan speed of 100 mm/s. Experiments were conducted at the Lithium Lasers Innovation Application Laboratory using the FEMTOFLASH 100 laser.