The Analysis on the Offset Error of cross-section Contour by Using the Simulated Measurement Model of Atomic Force Microscopy

Abstract

Under the foundation of molecular mechanics, this paper uses two-body potential energy function to construct a simulated nano-scale measurement model of the constant force mode of contact mode atomic force microscopy (AFM). The simulation is operated in such a way that when the probe tip runs across the sample surface, Morse potential energy is employed to calculate the force of sample atoms borne by the atoms at the probe tip. After calculation, the equivalent force on the cantilever of probe and the force-bearing rotation of the cantilever of probe can be acquired. At the measurement point, when the force-bearing rotation reaches the fixed rotation, the scanning height of this model can be obtained. By scanning in proper order, the scan curve of the simulated model can be acquired. This paper investigates the error of deviated distance incurred when the probe of different tip radii is scanning and measuring the cross-section of nano-scale standard sample, and analyzes how the appearance of the tip round and the tip edge oblique angle of the probe affect the deviated distance. The investigation of the error analysis is referential in compensating the error of AFM measurement in future, and can further enhance the accuracy of AFM scanning and measurement.