An atomic force microscope for the study of the effects of tip–sample interactions on dimensional metrology

Abstract

An atomic force microscope (AFM) has been developed for studying interactions between the AFM tip and the sample. Such interactions need to be taken into account when making quantitative measurements. The microscope reported here has both the conventional beam deflection system and a fibre optical interferometer for measuring the movement of the cantilever. Both can be simultaneously used so as to not only servo control the tip movements, but also detect residual movement of the cantilever. Additionally, a high-resolution homodyne differential optical interferometer is used to measure the vertical displacement between the cantilever holder and the sample, thereby providing traceability for vertical height measurements. The instrument is compatible with an x-ray interferometer, thereby facilitating high resolution one-dimensional scans in the X-direction whose metrology is based on the silicon d220 lattice spacing (0.192 nm). This paper concentrates on the first stage of the instrument's development and presents some preliminary results validating the instrument's performance and showing its potential.

Displacement Measurement

“…Fibre sensing and delivery has been used by some surface topography measuring instruments [93], and fibre sensors are used to measure the displacement of atomic force microscope cantilevers [94].…”

Morphological Dilation as Fractal Scaling in Roughness Measurement

“…white noise. If touching points are correlated relative to points far separated the PSD will be considerable at subordinate wavelengths and small short wavelengths [15] [16].…”

Characterization of Fiber-Forming Peptides and Proteins by Means of Atomic Force Microscopy

“…It follows that the sample topography is also going to affect the imaging resolution, as regions which are inaccessible by the probe will not be visible. Furthermore, tip-sample interactions, such as long-range repulsive forces or sample deformation can also change the apparent features observed [84]. Such artifacts can be minimized by a judicious choice of probe (Section 1.1.3), and true surface features can be calculated by deconvolution algorithms.…”