ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
A single-grid ultra-high-vacuum-compatible ion source was used to provide accelerated In+-dopant beams during Si(100) growth by molecular-beam epitaxy. Indium incorporation probabilities σ, determined by secondary ion mass spectrometry, in films grown at Ts=800 °C were too low to be measured for thermal In (σIn was 〈3×10−5 at Ts〉550 °C) . However, for accelerated In+ doping, σIn+ at 800 °C ranged from 0.03 to ∼1 for In+ acceleration energies EIn+ between 50 and 400 eV. Temperature-dependent Hall-effect and resistivity measurements were carried out on In+-doped Si films grown at Ts =800 °C with EIn+=200 eV . Indium was incorporated substitutionally into electrically active sites over a concentration ranging from 2×1015−2×1018 cm−3, which extends well above reported equilibrium solid-solubility limits. The acceptor-level ionization energy was 156 meV, consistent with previously published results for In-doped bulk Si. Room-temperature hole mobilities μ were in good agreement with the best reported data for B-doped bulk Si and were higher than previously reported values for annealed In-implanted Si. Temperature-dependent (77–400 K) mobilities μ(T) were well described by theoretical calculations, with no adjustable parameters, including lattice, ionized-impurity, neutral-impurity, and hole-hole scattering. Lattice scattering was found to dominate, although ionized-impurity scattering was still significant, at temperatures above ∼150 K where μ varied approximately as T−2.2 . Neutral-impurity scattering dominated at lower temperatures. Plan-view and cross-sectional transmission electron microscopy observations showed no indications of dislocations or other extended defects. Considering the entire set of results, there was no evidence of residual ion-bombardment-induced lattice damage.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.343062
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