High-speed drilling of glass and silicon carbide using femtosecond fibre laser

Femtosecond laser is a powerful tool for fabrication of microstructures in various substrates used in electronics manufacturing. We demonstrate the optimisation of the percussion drilling process for creating high-quality vias in glass and a wide bandgap semiconductor 4H-SiC. Remarkably, our results show excellent performance of repetitive single pulse drilling in glass with possibility to obtain high aspect ratio through glass via (TGV) with minimized taper and shiny walls. We show the influence of pulse repetition rate, pulse energy and pulse duration on the drilling process. On the other hand, superior performance 4H-SiC drilling was obtained using MHz bursts of pulses with the duration below 270 fs. The burst mode is an enabling factor for defect-free processing of 4H-SiC and boosting the drilling throughput. We demonstrate how tuning the burst length allows for increasing the throughput without compromising the spatial resolution and quality of the microstructures. Drilling of Si and 4H-SiC with full laser power of 30 W at 100 kHz repetition rate will be demonstrated. Experiments were performed at Fluence Ultrafast Laser Application Laboratory using Jasper X1 femtosecond fiber laser operating at 1030 nm.