Dynamics of the laser-induced nanostructuring of thin metal layers: experiment and theory

作者：Lorenz P^*; Kloeppel M; Smausz T; Csizmadia T; Ehrhardt M; Zimmer K; Hopp B

来源：Materials Research Express, 2015, 2(2): 026501.

DOI：10.1088/2053-1591/2/2/026501

• excimer laser
• nanostructuring
• metal layer
• simulation
• droplet formation

Nanostructures are of increasing importance in manifold application fields such as electronics, optics and beyond. However, the fast and cost-effective production of nanostructures is a big technological challenge for laser machining. One promising approach is laser irradiation of thin metal layers, which allows the fabrication of metal nanostructures induced by a melting and transformation process. The influence of laser parameters (laser fluence, laser pulse number) on the morphology of the nano-patterned film and the dynamics of the nanostructure formation during excimer laser irradiation of a 20 nm chromium film on fused silica were studied. The dynamics of nanopatterning, comprising hole and droplet formation, were investigated by time-dependent reflection and transmission measurements as well as time-dependent optical microscopy. The resulting patterns were investigated by optical and scanning electron microscopy (SEM). However, for an optimization of this process a better understanding of the underlying physical phenomena is necessary. Therefore, experimental data of laser-induced nanopatterning were compared with results of physical simulations that consider the heat equation (laser-solid interaction including melting and evaporation) and the Navier-Stokes equation (transformation processes of the molten phase). The simulations, making use of laser fluence-dependent effective material parameters (surface tension and viscosity), are in good agreement with the experimental results.

• 出版日期2015-2