Manufacturing an STM: Design, Assembly, and Preliminary Results
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Authors
Thom, Trevor
Issue Date
2025
Type
Thesis
Language
en_US
Keywords
Alternative Title
Abstract
The ability to view molecules and solids at the atomic level enables the characteri-zation of materials with atomic precision. Scanning tunneling microscopy (STM) is
a powerful way to create topographic images on the atomic scale. To image surfaces,
the STM utilizes the quantum mechanical tunneling of electrons flowing through a
vacuum barrier between a sample surface and an atomically sharp probe. Piezoelec-
tric actuators control the motion of the tip and sample. A feedback loop maintains
the tunneling current constant by controlling the central piezo, while the data ac-
quisition unit records changes in the vertical tip-sample distance. In the Beetle-type
STM constructed at the University of Nevada, Reno, raster scanning is performed by
bending three outer piezoelectric actuators such that the sample translates tangent
to the circumference of the sample holder. The piezo board controls the motion of the
piezoelectric actuators by applying precise voltages to their electrodes. An ultra-high
vacuum chamber and comprehensive vibration isolation system effectively isolate the
system from outside interference. Plasmonic probes are electrochemically etched and
ion beam-polished to reach atomic sharpness. An analysis of the STM experimental
systems is performed and the construction of the instrument is described. The anal-
ysis and description create an understanding of the necessary systems for STM to
operate. A detailed instruction on the creation of plasmonic probes is included. Dur-
ing the work on this thesis, I designed and machined several components, performed
electronics analysis, helped construction, prepared samples for analysis, and worked
to achieve molecular resolution. This thesis will serve as a manual for those joining
the Lee group to better understand how the systems they use came together.