Proceedings Article | 22 February 2011
Proc. SPIE. 7920, Laser Applications in Microelectronic and Optoelectronic Manufacturing (LAMOM) XVI
KEYWORDS: Gold, Metamaterials, Thin films, Beam splitters, Femtosecond phenomena, Laser irradiation, Sapphire, Thin film deposition, Liquids, Phase shifts
Interfering femtosecond laser can induce periodic induction of energy on a thin film deposited on a substrate, and
periodic thermal process is induced. This results in liquid motion of target, such as melting, inflation, flow and shrink,
and then it freezes due to temperature fall by thermal radiation and conduction. The resultant structures are nanobump,
nano-whisker, nano-waterdrop, nano-crown, and the shapes can be controlled by laser fluence, thin film thickness,
substrate material, etc.. The size of some structures is smaller than 10 nm in curvature radius, and the aspect ratio is over
20. In addition, duplicated structure of two shapes, or double density structures can be generated in a single shot of laser
irradiation by controlling the phase shift and power ratio between interfering beams. In the case of duplicated structure,
the density of nano-structures is doubled, and two different nano-structures appear alternately. These structures will be
useful in nanotechnology, especially in meta-material technology.
