Electric-field and Mechanical Vibration-assisted Atomic Force Microscope (AFM)-based Nanopatterning

Abstract

Atomic force microscope (AFM)-based nanopatterning is a cost-effective set of techniques to fabricate nanostructures with arbitrary shapes. However, existing AFM-based nanopatterning approaches have limitations in the patterning resolution and efficiency. Minimum feature size and nanopatterning performance in the mechanical force-induced process are limited by the radius and sharpness of the AFM tip. Electric-field-assisted atomic force microscope (E-AFM) nanolithography can fabricate nanopatterns with features smaller than the tip radius, but it is very challenging to find the appropriate input parameter window because the applicable tip bias range for success nanopatterning in E-AFM process is typically very small. Moreover, the small tip bias range often varies due to the variations in the tip geometry, tip radius, and tip conductive coating thickness, which causes difficult nanopatterning implementation. In this paper, we demonstrate a novel electric-field and mechanical vibration-assisted AFM-based nanofabrication approach, which enables high-resolution (sub-10 nm towards sub-5nm) and high-efficiency nanopatterning processes. The integration of in-plane vibration with the electric field increases the patterning speed, broadens the selectable ranges of applied voltages, and reduces the minimum tip bias required for nanopatterning as compared with E-AFM process, which significantly increases the versatility and capability of AFM-based nanopatterning and effectively avoids the tip damage.