Fabrication of Gold Nanostructures by SPM lithography
Sheng-Pin Hsu1*, Jhih-Wei Chen1, Yen-Chin Huang1, Yi-Chun Chen1
1Department of Physics, National Cheng Kung University, Tainan, Taiwan
* presenting author:Sheng-Pin Hsu, email:a0919853816@hotmail.com

Localized surface plasma (LSP) is the phenomenon that nanoparticles excited by electromagnetic wave on metal surface, leading to charge oscillation and exhibiting many interesting physical properties. Because LSP is confined by nanoparticles, it can be used to obtain sub-wavelength optical measurement and be treated as a high spatial resolution sensor of electric field. However, the arrangement of metallic nanoparticles on substrate affects the behavior of LSP. Thus, the ability to reliably control the nanostructures of metal particles on surface has been the top concern in our research. With atomic force microscopy (AFM) probe carving on polymethylmethacrylate (PMMA) thin film, we can make different pattern of gold nanoparticles and nanowire. Lithography parameters, including tip force and scanning direction, were controlled systematically to carve holes and grooves on PMMA. This process was followed by the deposition of gold film using E-beam evaporator on the surface of the substrate. After lifting off PMMA, gold nanoparticles and nanowires with ordered arrangement were examined by scanning electronic microscopy (SEM). The optical images showing LSP scattering were then investigated to realize the electric field distribution of the gold nanostructures.

Keywords: Surface Probe Microscopy, Nanostructure Lithography