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@PHDTHESIS{Stern:1044497,
      author       = {Stern, Christian},
      title        = {{R}eactive {F}ield {A}ssisted {S}intering of {N}ovel {R}are
                      {E}arth {G}arnets for {P}lasma {E}tching {A}pplications},
      volume       = {667},
      school       = {RWTH Aachen University},
      type         = {Dissertation},
      address      = {Jülich},
      publisher    = {Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag},
      reportid     = {FZJ-2025-03234},
      isbn         = {978-3-95806-833-9},
      series       = {Schriften des Forschungszentrums Jülich Reihe Energie $\&$
                      Umwelt / Energy $\&$ Environment},
      pages        = {VII, 109, XXVIII},
      year         = {2025},
      note         = {Keine Open Access Freigabe!; Dissertation, RWTH Aachen
                      University, 2025},
      abstract     = {Over the last decades, semiconductor manufacturing
                      processes have seen significant advancements. Due to their
                      high resistance to fluorine-based etching plasmas, advanced
                      structural ceramics, such as yttrium aluminum garnet (YAG),
                      are commonly used as inner wall materials in plasma etching
                      devices. However, driven by the ongoing refinement of the
                      manufacturing process and the increasing complexity of
                      plasma gas compositions, there is a growing need for
                      alternative materials that offer enhanced plasma etch
                      resistance. To address this, the following work investigates
                      lanthanoid garnets beyond YAG as alternative inner wall
                      materials for the application in fluorine-based etching
                      plasmas. It is hypothesized that substituting the Y3+ ion in
                      the garnet crystal with heavier ions can enhance overall
                      plasma etch resistance. The study first investigates the
                      effect of fully substituting Y3+ with the lanthanoids Er3+,
                      Yb3+, and Lu3+, on the plasma etch resistance. Additionally,
                      the impact of partially substituting the yttrium ion with
                      Yb3+ and Lu3+ was studied. Samples were processed using the
                      reactive field-assisted sintering technology/ spark plasma
                      sintering (FAST/SPS) of the respective oxides. This
                      innovative approach allows for near net shape consolidation
                      close to theoretical density in a single process step with
                      short processing times. The plasma etch resistance of the
                      ceramic samples was tested in a systematic etching study.
                      Specimens were exposed to fluorine-based etching plasmas
                      (Ar/CF4/O2). By adjusting main process parameters such as
                      bias voltage and process pressure, the corrosiveness of the
                      plasma was varied from weak to aggressive. Depending on the
                      plasma conditions, the erosion was either more chemically or
                      physically driven. The subsequent characterization procedure
                      was adapted according to the dominating erosion mechanisms.
                      To achieve a fundamental understanding of the erosion
                      process in weak plasma, a correlative approach for assessing
                      critical parameters of the induced chemical gradient in
                      etched samples was developed. Using this procedure, a
                      reduced plasma penetration was found in rare earth garnets
                      compared to YAG. However, in aggressive plasma conditions,
                      YAG outperformed lanthanoid garnets, even though a minor
                      effect of the heavier dopant ions was evident. By
                      investigating both application-oriented and fundamental
                      aspects, this work builds a solid basis for the
                      target-oriented application of alternative garnets in
                      semiconductor manufacturing processes.},
      cin          = {IMD-2},
      cid          = {I:(DE-Juel1)IMD-2-20101013},
      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/1044497},
}