Modeling and experimental verification of plasmas induced by high-power nanosecond laser-aluminum interactions in air

Solution-based adaptive parallel patterning by laser-induced local plasmonic surface defunctionalization

Adaptive mass fabrication method based on laser-induced plasmonic local surface defunctionalization was suggested to realize solution-based high resolution self-patterning on transparent substrate in parallel. After non-patterned functional monolayer was locally deactivated by laser-induced metallic plasma species, various micro/nano metal structures could be simultaneously fabricated by the parallel self-selective deposition of metal nanoparticles on a specific region. This method makes the eco-friendly and cost-effective production of high resolution pattern possible. Moreover, it can respond to design change actively due to the broad controllable range and easy change of key patterning specifications such as a resolution (subwavelength~100 μm), thickness (100 nm~6 μm), type (dot and line), and shape.

Temporal and spatial evolution of Si atoms in plasmas produced by a nanosecond laser ablating silicon carbide crystals

Optical emission spectroscopy (OES) was used to study the evolution behavior of the neutral Si atoms in the plasma produced by nanosecond pulsed-laser beam irradiating on SiC crystal targets. The OES measurements indicated that the electron temperature and density in the plasma had maximum values around a region about 2mm from the target surface. Based on the temporal and spatial evolution of the spectral line at 633.19 nm originating from excited Si atoms, it was found that these Si atoms have short decay times and long range spatial distribution in vacuum. At the initial growth stage of SiC thin films using pulsed-laser deposition (PLD) technique, these Si atoms were found possibly to arrive at the Si substrate to form defects near the SiC/Si interface. By comparing the OES result measured in vacuum and that measured in ambient air, it was deduced that by properly adjusting the background gas species and pressure, the quality of the films prepared by PLD technique may be improved.