A height error compensation method based on contact mode AFM

Abstract

Nowadays, atomic force microscope(AFM) has become an important tool in micro/nano research, and its height image even has been taken as an indispensable approach to understand characters of micro/nano samples. However, some preceding researches have shown that the height image scanned by AFM appears to be lower than expected sometime because of the compression force of the tip, and some arguments have also been proposed to try to explain this phenomenon. But until now, there is not a method analyzing it systematically and quantificationally, let alone compensate this error in the height image. Therefore, in this paper, a new error compensation method is proposed. First, since the force curve of AFM has become an effective method to research the elasticity, through analysis on the force curve of different kinds of materials, the error source of the height image is proved in theory based on contact mode AFM. Subsequently an error compensation method based on information fusion and parameters identification is proposed. Finally, extensively experiments are conducted with respect to the height measurement of nano carbon tube. This method not only has an integrated foundation in theory analysis, but also has calculated the error firstly in the height image of AFM numerically, and the results of experiments show its validity and correctness.