| Summary: | There is a large number of measurement techniques that is used for a surface inspection and a
characterization of different types of materials. One of these techniques is a contact potential
difference (CPD) scanning technique. In this project a non-vibrating contact potential difference
(nvCPD) method is utilized to measure a work function and a topographical structure of a sample
surface. A sample is mounted on a spindle that rotates at high speed. A nvCPD sensor detects
work-function variations during movement above the sample surface. There are certain factors that
create difficulties during the measurement process. A nonplanar sample surface, the spindle wobble
and an incline of a mounted sample impede the safe (without impacting the surface) scanning at a
close distance. The goal of this thesis was to implement a height sensor as a feedback device to
dynamically control and adjust a CPD sensor flying height. Since a CPD signal is inversely
proportional to the flying height, minimization of this height will enhance the signal magnitude, the
signal-to-noise ratio and the resolution of measurements.
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