Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5129049 | Procedia Manufacturing | 2016 | 15 Pages |
Femtosecond laser ablation of gold thin film on the front and backside of silicon substrate is investigated, with backside ablation being the focus and front side ablation for comparison. The experiments are performed using 100 fs pulses delivered through an ultrafast laser source combined with an OPA for wavelength conversion at 1300Â nm. We create a single shot ablation matrix by varying focus position and pulse energy. The laser beam is characterized using an IR imaging technique at both the front and backside of the substrate. It is found that the pulse profile experiences little distortion after passing though the 1Â mm silicon substrate, despite the high pulse energy used. However, a comparison of the front and back ablation site indicates significant attenuation of pulse energy due to nonlinear absorption. Two types of damage happen depending on laser fluence: ablation and burst. Burst damage is confirmed with finite element simulation.