Nanolithography with a NSOM tip: Part I-numerical simulations

Abstract

Due to its ability of recording images of surfaces with sub-wavelength resolution, near-field scanning optical lithography (NSOL) provides a prospective solution for nanolithography. A variety of different photolithography processes at the nanoscale have been realized. However, the development of polymerization at optical near field is yet an unexplored area to researchers. In this paper, we report a series of computerized simulations to investigate some basic phenomena in NSOL. In this work, we introduce a cylindrical model to represent the metal-coated NSOM tip illuminated by a Gaussian beam. Using numerical method to solve the Maxwell equations to determine light intensity distribution, we applied the result of intensity profile for the first time to study the induced photo-polymerization from reaction kinetic equations of continuum media. We then studied the dependence of curing height and curing radius upon exposure time, with the optimized aperture size and tip sample distance. It has been demonstrated in this work the feasibility of nanolithography with NSOM tip, which would provide a new pathway to nanofabrication.