Formation of ordered arrays of Si and GaAs nanostructures by single-shot laser irradiation in near-field at the solid/liquid interface

We report a comprehensive study of a laser initiated liquid assisted technique to pattern Si and GaAs substrates. Silica colloidal particles masks, sizes 3 μ m and 700 nm, were formed on the substrates and three laser wavelengths: 355 nm/532 nm at 8 ps laser pulse duration and 800 nm at 70 fs laser pulse duration were used. The laser processing was assisted by liquid precursors, namely methanol and carbon tetrachloride. The regular structures develop from holes to bumps and nanorings, depending on the laser power and the size of the colloidal particle mask. Silica colloidal particles act both as a template mask and also based on the liquid-tuned optical field enhancement that shows near field enhancement effects. The patterns are defined by the liquid chemical composition and no influence of the pulse duration (ps or fs) was observed on their design. (papers)