Scanning probe lithography on InAs substrate

In this study, we focus our interest on patterning a conventional electron beam resist by electron field emission exposure using Atomic Force Microscope (AFM). We have fabricated 50-140 nm deep structures in InAs with the resolution less than 100 nm through 20 nm thick PMMA resist that was exposed. According to our knowledge, electron field emission exposure of resist has already been performed on gold, silicon but never on InAs substrate. Compared with other semiconductors, InAs has the Fermi level pinned in the conduction band leading to the superior electric property even for nanometer scale structures. Using electron field emission exposure technique, structures deeper than 100 nm can be performed that is enough to release suspended free structures after chemical etching, being ideal for nanowire and NanoElectroMechanical Systems (NEMS). In the following, we will describe the experimental set-up and results of fabrication.