A Monte Carlo Simulator for Non-contact Mode Atomic Force Microscopy

Nanolithography using Non-Contact Mode Atomic Force Microscopy (NCM-AFM) is a promising method for the manufacture of nanometer sized devices. Compact models which suggest nanopatterned oxide dots with Gaussian or Lorentzian profiles are implemented in a Monte Carlo simulator in a level set environment. An alternative to compact models is explored with a physics based Monte Carlo model, where the AFM tip is treated as a point charge and the silicon wafer as an infinite conducting plane. The strength of the generated electric field creates oxyions which accelerate towards the silicon surface and cause oxide growth and surface deformations. A physics based model is presented, generating an oxide dot based on the induced surface charge density. Comparisons to empirical models suggest that a Lorentzian profile is better suited to describe surface deformations when compared to the Gaussian profile.