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https://hdl.handle.net/2115/50245

Local structures of isovalent and heterovalent dilute impurities in Si crystal probed by fluorescence x-ray absorption fine structure

英語

semiconductor doping

1997-11-15

American Institute of Physics

Journal of Applied Physics

82(10)

4810-4815

Local structures of dilute isovalent and heterovalent impurity atoms in Si crystal (Si:X, X=Ga, Ge, As) have been studied by fluorescence x-ray absorption fine structure. The distortion of local lattice around the impurity atoms was evaluated from the Si-X bond length determined by extended x-ray absorption fine structure. The results demonstrate that the local lattice deformation is strongly dependent on the electronic configuration of impurity atoms, i.e., we find an anomalous expansion (0.09±0.01Å) along the [111] direction for donor (As) atoms but much smaller magnitude (0.03±0.01Å) for isovalent (Ge) atoms and acceptor (Ga) atoms. The results suggest that the local lattice distortions are strongly affected by the Coulomb interactions between the localized charge, which piles up to screen the ion core and the bond charge, and the ion-core repulsion. Absence of anomaly in case of negatively charged Ga atoms suggests that the former mechanism is a dominant factor for anomalous lattice expansion.

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Copyright 1997 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in J. Appl. Phys. 82, 4810 (1997) and may be found at https://dx.doi.org/10.1063/1.366340

0021-8979