Femtosecond laser-induced damage threshold incubation in SrTiO3 thin films

Autor(es)

Paula, Kelly T. ; Clabel, H. Jose L. ; Vieira, Eduardo V. M. ; Mastelaro, Valmor R. ; Vollet-Filho, Jose Dirceu ; Mendonca, Cleber R.

• Tipo de documento: Artigo Científico
• Fonte: Applied Surface Science; v. 680, p. 10-pg., 2025-01-30.

Resumo

This study delved into the microfabrication process on SrTiO3 thin films using femtosecond laser pulses, focusing on characterizing ablation behavior and elucidating on incubation parameters. A combination of microscopy techniques and systematic analysis of laser-material interactions provided insights into the features and fundamental processes governing the laser-induced modification of SrTiO3 thin films. The cutting profile morphology indicated high-resolution material removal, with line widths ranging from 0.6 to 1.6 mu m, depending on number of pulses and energy. The study revealed a low incubation parameter for SrTiO3 thin films, quantified as (0.03 +/- 0.01), indicating that a considerable number of pulses is required to cause damage to the material. Additionally, threshold energies for damage were determined to be 17.9 nJ for 20,000 pulses and 35.2 nJ for a single pulse. AFM analysis showed that the depth of the micromachined lines increased from approximately 80 nm to 315 nm with higher pulse energies, confirming substantial material removal. The Keldysh parameter provides insights into ionization mechanisms under femtosecond-laser irradiation, highlighting the dominance of tunneling ionization. Using higher pulse energies, the center of the microstructures exhibited significantly reduced Raman signals, correlating with substantial material removal, which was confirmed by atomic force microscopy. EDS analyses indicated that the elemental composition of the irradiated regions closely resembled the stoichiometric composition of SrTiO3, while the center of the microstructures showed significant oxygen levels but lacked titanium and strontium, consistent with the findings from AFM and Raman microscopy. (AU)

• Processo FAPESP: 18/11283-7 - Fotônica não linear: espectroscopia e processamento avançado de materiais
• Beneficiário: Cleber Renato Mendonça
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 21/11484-5 - Geração de segundo harmônico e espalhamento hiper-Rayleigh em titanato de bário para aplicações fotônicas
• Beneficiário: José Luis Clabel Huamán
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado