Browsing by Author "Johnson, BC"

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Boron enhanced H diffusion in amorphous Si formed by in implantation
    (Cambridge University Press, 2008-03-25) Johnson, BC; Atanacio, AJ; Prince, KE; McCallum, JC
    Boron enhanced H diffusion in amorphous Si (a-Si) layers formed by ion implantation is observed using secondary ion mass spectroscopy (SIMS). Constant concentrations of B were achieved using multiple energy B implantations into thick a-Si layers. The evolution of single H implanted profiles centered on the uniformly B-implanted regions was studied for partial anneals at temperatures in the range 380 – 640 °C. Boron enhanced diffusion is observed and the enhanced diffusion coefficient shows trends with temperature typically associated with a Fermi level shifting dependence. A modified form of the generalized Fermi level shifting model is considered in light of these results. © Materials Research Society 2008
  • No Thumbnail Available
    Item
    dLow temperature of formation of nickel germanide by reaction of nickel and crystalline germanium
    (Springer Nature, 2014-12) Algahtani, F; Leech, PW; Reeves, GK; Holland, AS; Blackford, MG; Thorogood, GJ; McCallum, JC; Johnson, BC
    The formation of nickel germanide has been examined over a range of low temperatures (200-400 °C) in an attempt to minimize the thermal budget for the process. Cross-sectional Transmission Electron Microscopy (TEM) was used to determine the texture of the germanide layer and the morphology and constituent composition of the Ge/NiGe interface. The onset and completion of reaction between Ni and Ge were identified by means of a heated stage in combination with in-situ x-ray diffraction (XRD) measurements. The stages of reaction were also monitored using measurements of sheet resistance of the germanides by the Van der Pauw technique. The results have shown that the minimum temperature for the initiation of reaction of Ni and Ge to form NiGe was 225 °C. However, an annealing temperature > 275 °C was necessary for the extensive (and practical) formation of NiGe. Between 200 and 300 °C, the duration of annealing required for the formation of NiGe was significantly longer than at higher temperatures. The stoichiometry of the germanide was very close to NiGe (1:1) as determined using energy dispersive spectroscopy (EDS).
  • No Thumbnail Available
    Item
    Intrinsic and boron-enhanced hydrogen diffusion in amorphous silicon formed by ion implantation
    (American Institute of Physics, 2009-09-10) Johnson, BC; McCallum, JC; Atanacio, AJ; Prince, KE
    The concentration dependence of H diffusion in amorphous Si (a-Si) formed by ion implantation is reported for implanted H profiles. An empirical relationship is proposed which relates the diffusion coefficient to the H concentration valid up to 0.3 at. %. B-enhanced H diffusion is observed and shows trends with temperature typically associated with a Fermi level shifting dependence. A modified form of the generalized Fermi level shifting model is applied to these data. The Department of Electronic Materials Engineering at the Australian National University is acknowledged for providing access to ion implanting facilities. This work was supported by grants from the Australian Research Council and the Australian Institute of Nuclear Science and Engineering (Award No. AINGRA08035). © 2009 American Institute of Physics