The Experimental and Modeling Study of Femtosecond Laser-Ablated Silicon Surface

Abstract

In this study, monocrystalline silicon was ablated by a single 1030 nm femtosecond laser pulse. Variable laser fluence (0.16–3.06 J/cm2) was used, and two ablation thresholds (0.8 and 1.67 J/cm2) were determined experimentally. A two-temperature model was established based on the dynamic optical model, the carrier density model, and the phase explosion model for comparison with experimental results. The melting (0.25 J/cm2) and vaporization (0.80 J/cm2) thresholds were determined when the lattice temperature reached melting and boiling points, so as to overcome the latent heat. Finally, the ablation depth was calculated using the phase explosion model, and the ablation threshold was 1.5 J/cm2. The comparisons show that the proposed model can predict the ablation depth obtained by a single femtosecond laser pulse.

Keywords

• femtosecond laser
• silicon
• melting threshold
• ablation threshold
• phase explosion