The error analysis of cross-section curve with contact mode atomic force microscopy simulation measurement by using trapezoidal cantilever based on molecular mechanics

Abstract

Based on the molecular mechanics, this paper uses the two-body potential energy function to construct a trapezoidal cantilever nano-scale simulation measurement model of contact mode atomic force microscopy (AFM) under the constant force mode to simulate the measurement the nano-scale standard stair-step sample. This paper investigates the offset distance error occurred during scanning the cross-section curve of the standard step sample. The two probes employed in this study are of different cantilever geometry and probe material (V-shaped Si3N4 cantilever and trapezoidal Si cantilever), but have the same tip radius of 3.65 nm. It is found that the probe tip radius and the tip edge oblique angle of the probe influenced the cross-section curve during simulation measurement. Therefore, the factor influencing this cross-section curve appearance is mainly the geometry form of the probe. It can be observed that the cross-section curve under simulation measurement by using the trapezoidal Si cantilever is closer to the cross-section curve of nano-scale standard sample than under simulation measurement by using the V-shaped Si3N4 cantilever. It can be known that the probe material can influence the cross-section curve under simulated measurement. The investigation of the error analysis is referential in compensating the error of AFM measurement in the future, and can be used to further enhance the accuracy of AFM scanning and measurement.