Deeply sub-wavelength laser nanopatterning of Si surface in dielectric fluids: Manipulation by surface plasmon resonance

• Published in: Applied surface science Vol. 519; p. 146204
• Main Authors: Kudryashov, Sergey I., Nastulyavichus, Alena A., Saraeva, Irina N., Rudenko, Andrey A., Zayarny, Dmitry A., Ionin, Andrey A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 30.07.2020
• Subjects: Femtosecond laser ablation; Si nanoripples; Wet filament-mediated nanopatterning; Femtosecond laser ablation; Wet filament-mediated nanopatterning; Si nanoripples
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2020.146204

[Display omitted] •Deep sub-wavelength surface nanopatterning of silicon immersed in liquids was performed by femtosecond laser pulses.•The ultimately small nanoripples were generated via interference of counter-propagating surface plasmons.•Wavenumbers of surface plasmons are predicted and shown to scale by squared refraction index of contact dielectric fluids.•Wavenumbers of surface plasmon-polaritons are predicted to scale by refraction index of contact dielectric fluids.•Si nanoripples, femtosecond laser ablation, wet filament-mediated nanopatterning. Deep sub-wavelength, large-scale surface nanopatterning of silicon (Si) wafers immersed in water or carbon disulfide, in the form of ultrafine nanoripples was performed by multi-shot 1030-nm femtosecond laser exposures. Our simulations indicate the key role of surface plasmons, with their extreme wavenumbers tunable versus the dielectric permittivity of the contact dielectric fluids. The factors of the squared optical refraction index of fluids, excitation and interference of counter-propagating surface plasmons were revealed to provide in both these fluids the ultimately small (~100 nm) periods of the nanoripples. The realized advanced wet laser nanopatterning of Si surfaces, unattainable via dry laser processing, paves the way toward nanoscale laser lithography.