An automatic compensation method on compression effect and surface elasticity measurement based on the deflection signal of AFM

Abstract

Atomic force microscope (AFM), as an important instrument in micro/nano operation, has been widely used to measure sample’s height information. However, the so called compression effect, due to force aroused from the contact of AFM tip with a sample surface, would result in imprecision of the surface’s height measurement, i.e., the measured height is lower than expected. Up to now, there is not any effective and rapid method to attenuate this kind of measurement error. Thus, in this paper, an algorithm to obtain high accurate height measurement is proposed. Firstly, the concept of force curve is used to analyze the basic principle of the compression effect. Secondly, an automatic compensation method by fusing the height signal and the deflection signal is proposed. The proposed algorithm can also be used to obtain a surface elasticity image. Finally, in order to validate the proposed method, two experiments are conducted with respect to mutli-wall nano-carbon tubes on a silicon substrate and graphemes on a mica substrate.