Highly Regular LIPSS on Thin Molybdenum Films: Optimization and Generic Criteria.

Area of Science:

• Materials Science
• Nanotechnology
• Laser Physics

Background:

• Laser-induced periodic surface structures (LIPSS) offer unique surface properties.
• Fabricating highly regular LIPSS (HR-LIPSS) over large areas is challenging.
• Understanding material-laser interactions is key for controlled nanostructuring.

Purpose of the Study:

• To determine optimal laser irradiation conditions for large-area HR-LIPSS fabrication.
• To investigate the influence of laser parameters on LIPSS regularity.
• To analyze the underlying physical mechanisms of HR-LIPSS formation on Mo films.

Main Methods:

• Systematic experimental study using a 1030 nm, 1.4 ps pulsed laser.
• Scanning electron microscopy (SEM) for structural analysis.
• Dispersion of LIPSS orientation angle (DLOA) as a regularity criterion.
• Theoretical analysis of film heating and surface plasmon polariton excitation.

Main Results:

• Identified favorable laser fluence and beam scanning overlaps for HR-LIPSS.
• Achieved DLOA values below 10 degrees, indicating high regularity.
• Provided insights into film heating and potential surface plasmon excitation.
• Discussed the possible role of film dewetting in the process.

Conclusions:

• Optimal laser parameters were established for reproducible, large-area HR-LIPSS fabrication on Mo films.
• The study contributes to the understanding of nanostructure formation via laser-matter interaction.
• Findings are relevant for applications requiring precisely structured surfaces.