% IMPORTANT: The following is UTF-8 encoded. This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.
@PHDTHESIS{Kindelmann:897474,
author = {Kindelmann, Moritz},
title = {{F}ield assisted sintering of yttria ceramics for plasma
etching applications},
volume = {553},
school = {RWTH Aachen},
type = {Dissertation},
address = {Jülich},
publisher = {Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag},
reportid = {FZJ-2021-03807},
isbn = {978-3-95806-579-6},
series = {Schriften des Forschungszentrums Jülich. Reihe Energie
$\&$ Umwelt / Energy $\&$ Environment},
pages = {VI, 122, XXX S.},
year = {2021},
note = {RWTH Aachen, Diss., 2021},
abstract = {Advanced ceramics materials like yttrium oxide
(Y$_{2}$O$_{3}$) are of high interest for critical
manufacturing processes in the semiconductor industry due to
their high chemical stability in contact with fluorine based
etching plasmas. However, until now Y$_{2}$O$_{3}$ gets
primarily applied as a functional coating deposited by
thermal spray or aerosol deposition technique due to
complications associated with the manufacturing of bulk
ceramic components. Yttria exhibits a low sinterability when
conventionally processed and fabricating large scale samples
with high performance concerning chemical purity and
relative density is a challenging task. Complex processing
routes using conventional or vacuum sintering and an
additional post-compaction step by hot isostatic pressing
are necessary to achieve relative densities which are
matching the requirements of the semiconductor industry.
These major drawbacks have prevented the application of bulk
Y$_{2}$O$_{3}$ components in state of the art semiconductor
manufacturing devices. Therefore, in this work, field
assisted sintering technique /spark plasma sintering
(FAST/SPS) is investigated as a straight forward processing
technique which enables to consolidate high performance,
dense ceramic components in a single processing step. In two
separate parts, applied and fundamental research questions
are going to be addressed. The first part of this work
focuses on evaluating the direct processability of
commercial powders, solving challenges during the upscaling
of sample sizes, processing of complex shaped components as
well as characterizing the impact of rare earth doping on
sintering and grain growth. Upscaling of ceramic samples is
generally hindered by the formation of thermal
inhomogeneities in the tool setup. Therefore the application
of carbon fibre reinforced carbon spacers and their optimal
position in the FAST/SPS tool was investigated by coupling
experiments and simulations. Furthermore, graphite powder
bed assisted FAST/SPS was applied to study the possibilities
of sintering multiple complex shaped Y$_{2}$O$_{3}$ samples
in one step. Lastly, the influence of rare earth doping with
La$^{3+}$ and Gd$^{3+}$ on sintering and grain growth of
Y$_{2}$O$_{3}$ during FAST/SPS processing was studied
thoroughly. The segregation of La$^{3+}$ decelerated both
sintering and grain boundary kinetics through a solute drage
ffect, effectively preventing pore detachment at high
sintering temperatures and leading to enhanced densification
in the final stage of sintering. [...]},
cin = {IEK-1 / ER-C-2},
cid = {I:(DE-Juel1)IEK-1-20101013 / I:(DE-Juel1)ER-C-2-20170209},
pnm = {899 - ohne Topic (POF4-899)},
pid = {G:(DE-HGF)POF4-899},
typ = {PUB:(DE-HGF)3 / PUB:(DE-HGF)11},
url = {https://juser.fz-juelich.de/record/897474},
}