Single-pulse excimer laser nanostructuring of silicon: A heat transfer problem and surface morphology

• DOI: 10.1063/1.2910196
• Publication Date: 2008-05-07T14:59:35Z
• Authors: Julia Eizenkop; Ivan Avrutsky; Daniel G. Georgiev; Vipin Chaudchary
• Keywords: 0103 physical sciences; 01 natural sciences

We present computer modeling along with experimental data on the formation of sharp conical tips silicon-based three-layer structures that consist a single-crystal Si layer 1 μm silica bulk substrate. The upper layers thicknesses in range 0.8−4.1 were irradiated by single pulses from KrF excimer laser focused onto spot several micrometers diameter. simulation includes two-dimensional time-dependent heat transfer and phase transformations films result irradiation (the Stefan problem). After pulse, molten material self-cools resolidifies, forming structure, height which can exceed depending conditions. also performed simulations for experiments involving single-pulse silicon, reported other groups. discuss conditions under different types (cones versus hollows) emerge. confirm correlation between presence lateral resolidification condition after pulse solidified surface.