Simulation of surface plasmon nanolithography using tapered structure

A localized surface plasmon nanolithography (LSPN) technique using tapered structure is proposed and demonstrated to produce patterns with sub-wavelength feature size. The special masks with periodic taper tips are employed to excite surface plasmon polaritons (SPPs) on the illuminated side, and the SPP waves propagate toward the tips along the taper surface, which causes most of energy accumulation at the tips and gives rise to high local field enhancement in a nearfield region around the tips. Highly efficient nanolithography with sub-50nm feature size has been demonstrated by using the FDTD simulation results at different tip widths, at the same time, the variation of tip angel has been proved to have great influence on transmission efficiency, and also affects the line width.