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@PHDTHESIS{Tnnesmann:37449,
      author       = {Tönnesmann, Andreas},
      title        = {{U}ntersuchung von pseudomorphen
                      {I}n{G}a{A}s/{I}n{A}l{A}s/{I}n{P} {H}igh {E}lectron
                      {M}obility {T}ransistoren im {H}inblick auf kryogene
                      {A}nwendungen},
      volume       = {4043},
      issn         = {0944-2952},
      school       = {Techn. Hochsch. Aachen},
      type         = {Dr. (FH)},
      address      = {Jülich},
      publisher    = {Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag},
      reportid     = {PreJuSER-37449, Juel-4043},
      series       = {Berichte des Forschungszentrums Jülich},
      pages        = {II, 119 p.},
      year         = {2003},
      note         = {Record converted from VDB: 12.11.2012; Aachen, Techn.
                      Hochsch., Diss., 2003},
      abstract     = {A wide variety of new data communication applications
                      demand ever-increasing transmission capacities. The
                      InGaAs/InAlAs/InP layer stack based High Electron Mobility
                      Transistor (HEMT) is currently regarded as the most
                      promising active device in communication systems as it has
                      the highest cut-off frequencies of all transistor types. Due
                      to reduced phonon scattering of the charge carriers, the
                      HEMT is expected to exhibit even better noise and high
                      frequency characteristics for operations at cryogenic
                      temperatures, for instance in mixers or oscillators located
                      in satellites or ground based systems with appropriate
                      cooling equipment. This work focuses an the reduction of
                      access resistances and the fabrication of very short gate
                      lengths as the biggest technological challenges realizing
                      highest cut-off frequencies at any temperature. In addition,
                      the reproducibility and robustness of the implemented gate
                      technologies are fundamental criteria for applications. In
                      comparison to other transistor designs, the InAlAs/InGaAs
                      HEMTs are stronger affected by undesirable, partly material
                      dependent, short channel effects like early breakdown, high
                      gate currents, impact ionization, the kink effect, and a
                      shift in the threshold voltage. Measurements at liquid
                      nitrogen temperature an transistors produced in this work
                      provide further insight into the poorly understood
                      interrelationship between these effects. At liquid nitrogen
                      temperature, the cut-off frequency of 180 GHz and the
                      maximum oscillation frequency of 300 GHz of short channel
                      transistors at room temperature increase by 20 $\%$ and 30
                      $\%,$ respectively, while the breakdown voltage remains at
                      high values above 8 V.},
      cin          = {ISG-1},
      cid          = {I:(DE-Juel1)VDB41},
      pnm          = {Materialien, Prozesse und Bauelemente für die Mikro- und
                      Nanoelektronik},
      pid          = {G:(DE-Juel1)FUEK252},
      typ          = {PUB:(DE-HGF)11 / PUB:(DE-HGF)3},
      url          = {https://juser.fz-juelich.de/record/37449},
}