Mechanism study of femtosecond laser-induced periodic surface structures on single-crystal silicon: Insights from two-temperature model and self-organization

作者：Zhaoxu Li, Shi Bai, H. Chen, Mingyang Han, Xiao Yang, Koji Sugioka · 发表于：Journal of Laser Applications · 年份：2025 · DOI：10.2351/7.0001786 · 被引用次数：5 · 研究领域：Laser Material Processing Techniques、Force Microscopy Techniques and Applications、Silicon Nanostructures and Photoluminescence

The formation of laser-induced periodic surface structures (LIPSS) is characterized by the periodic spatial modulation of laser energy on a target surface, transient changes in the optical response, and surface melting or ablation. Based on the short interaction time between femtosecond laser pulses and materials, we investigate the mechanism behind the formation of LIPSS on single-crystal Si via numerical simulations. A two-dimensional physical model is developed, which is combined with the Drude model to predict the dynamic optical properties and thermal response of single-crystal Si under femtosecond laser irradiation. The transient equilibrium processes of carrier density, electron temperature, and lattice temperature are analyzed, with a focus on the relationships between temperature field, laser fluence, and melting/ablation threshold. The calculated LIPSS periods, derived from correlations between optical properties and surface morphology, showed excellent agreement with the experimental results. Notably, “ring-like” HSFL structures exhibit a distinct formation mechanism compared to conventional linear LIPSS; while linear LIPSS primarily arise from interference between incident laser light and surface plasmon polaritons, “ring-like” HSFL structures are governed by self-organization-driven surface instabilities, involving melt flow and reorganization effects. This study provides new insights into the self-organization pathways of LIPSS morphology under femtosecond laser...