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<div class="csl-entry">Silvano de Sousa, J. (2009). <i>Scanning probe capacitance measurements on GaAs and Si with Schottky and MOS junctions</i> [Diploma Thesis, Technische Universität Wien]. reposiTUm. https://resolver.obvsg.at/urn:nbn:at:at-ubtuw:1-29368</div>
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This Work consists of Scanning Probe Capacitance measurements made with an Atomic Force Microscope (AFM) tip as an electrode in contact with two different materials. In the first part we used a Gallium Arsenide wafer as sample composed with layers of different doping concentrations previously defined by simulating capacitance curves. These capacitance measurements were performed with Schottky and MOS junctions. The second part consists of measurements performed on a Silicon based solar cell.<br />We have also measured the capacitance of the same GaAs wafer in the same conditions on a large scale set up (device) which is well understood and easier to describe from the point of view of the Poisson's equation solution and these measurements were used for a comparison with the AFM measurements. Except by the surface impurities (such as oxides and water films) that can influence the capacitance curve behavior in the AFM, in the Schottky case, no significant differences between the AFM and the device measurements were found. On the other hand, in the MOS case, the capacitance curve behavior is completely different in both set ups (AFM and device). In the large scale set up, at 1kHz, no low frequency behavior is presented. On the other way around, the capacitance curve measured with the AFM tip presents a low frequency characteristic for measurements performed with frequencies up to 20kHz. The believed reason for this unexpected behavior is the spherical symmetry of the electrical field produced by the AFM tip, the high density of minorities right below the oxide/wafer interface due to the surface states of GaAs and the charges contained in the oxide that help attracting the minorities carriers to the surface. The cutoff frequency for this low frequency behavior of the capacitance has been estimated to be 3,85 kHz and the results of these measurements in the GaAs-MOS capacitor in the AFM will be submitted for publication in specialized scientific journals.<br />In the second part of this work, in chapter 5, we performed capacitance measurements along a Si p-n junction and, observing the change of behavior of the capacitance curves that go from high (while the tip was set in the p-type neutral bulk) to low frequency (as the tip approaches the space charge region of the junction), we were able to determine that the electrons diffused from the n-type approximately 288nm inside of the p-type Si (space charge region). From those measurements, we could also estimate the doping profiles of each Si type.
en
dc.language
English
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dc.language.iso
en
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dc.rights.uri
http://rightsstatements.org/vocab/InC/1.0/
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dc.subject
Rastersondenmikroskopie
de
dc.subject
GaAS
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dc.subject
Halbleiter
de
dc.subject
MOS
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dc.subject
Schottky
de
dc.subject
Nanotechnologie
de
dc.subject
AFM
de
dc.subject
Si
de
dc.subject
p-n junction
de
dc.subject
Scanning probe capacitance
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dc.subject
GaAS
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dc.subject
semiconductor
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dc.subject
MOS
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dc.subject
Schottky
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dc.subject
Nanotechnologie
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dc.subject
AFM
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dc.subject
Si
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dc.subject
p-n junction
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dc.title
Scanning probe capacitance measurements on GaAs and Si with Schottky and MOS junctions
en
dc.type
Thesis
en
dc.type
Hochschulschrift
de
dc.rights.license
In Copyright
en
dc.rights.license
Urheberrechtsschutz
de
dc.contributor.affiliation
TU Wien, Österreich
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dc.rights.holder
Jonathan Silvano de Sousa
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tuw.version
vor
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tuw.thesisinformation
Technische Universität Wien
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dc.contributor.assistant
Smoliner, Jürgen
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tuw.publication.orgunit
E138 - Institut für Festkörperphysik
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dc.type.qualificationlevel
Diploma
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dc.identifier.libraryid
AC05041172
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dc.description.numberOfPages
88
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dc.identifier.urn
urn:nbn:at:at-ubtuw:1-29368
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dc.thesistype
Diplomarbeit
de
dc.thesistype
Diploma Thesis
en
dc.rights.identifier
In Copyright
en
dc.rights.identifier
Urheberrechtsschutz
de
tuw.advisor.orcid
0000-0002-7096-6092
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item.fulltext
with Fulltext
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item.cerifentitytype
Publications
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item.mimetype
application/pdf
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item.openairecristype
http://purl.org/coar/resource_type/c_bdcc
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item.languageiso639-1
en
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item.openaccessfulltext
Open Access
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item.openairetype
master thesis
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item.grantfulltext
open
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crisitem.author.dept
E362 - Institut für Festkörperelektronik
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crisitem.author.parentorg
E350 - Fakultät für Elektrotechnik und Informationstechnik