Ion beam lithograpy using a nano-aperture

Abstract

A high aspect ratio nano-aperture mask was used to perform sub-micrometre lithography with MeV ions. Such a mask can localise ion placement in ion machining or doping, including the fabrication of high aspect ratio structures from ion beam damaged regions by subsequent etching. Ion scattering and straggling is the main limiting factor for the transmission with respect to transmitted energy, lateral intensity and angular intensity distribution of the ions. These limits are investigated by a 3D Monte Carlo modelling program based on the SRIM code; simulation of 1.5 MeV He incident on nano-scale apertures of various diameters indicates that the masking is highly effective. The simulation result..