Dynamics and control of Atomic Force Microscopy

Abstract

The technique of Atomic Force Microscopy (AFM) is one of the major inventions of the twentieth century which substantially contributed to our understanding of the nanoscale world. In contrast to other microscopy techniques, the AFM does not operate based on the electromagnetic waves, but nano-mechanical interactions between the sample surface and a sharp probe. Therefore, its resolution is not fundamentally limited to the diffraction limit of light, but the sharpness of the probe tip which can be as small as a few atoms. The images and data obtained by AFM have had crucial importance for the scientists in the fields of biology, material science, and experimental physics. However, AFM experiments have always involved some challenges. Particularly, the limited imaging speed, and the probability of damaging the samples hinder scientists from extracting the necessary information on the samples. Besides its applications as a research tool, the AFM could potentially solve some of the challenges in semiconductor industry as a metrology and inspection tool, however, the aforementioned limitations are even more restrictive for any industrial use. Therefore, it is imperative to develop apparatus and methods which can increase the speed and reliability of AFM. In this thesis, we try to understand the physics of AFM and contribute to its development towards a potential industrial and clinical tool, from the perspective of dynamics and control of its cantilever.