Abstract
The total energies and structures of a number of Be-induced defects in Si are investigated using ab-initio local density calculations. Our primary results are: 1) The geometry of the isoelectronic center is found to correspond to a {xc[111]} substitutionalinterstitial pair (SIP); 2) The low energy defect spectrum includes large Be complexes containing at least one substitutional atom; and 3) Simple bonding rules exist for the stability of the different types of bonds in the material. Thus the Si-Be bond is found to be stable for all defect configurations while the Be-Be bond is metastable.
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This measurement is attributed to John E. Baker in reference 2.
Roger K. Crouch, James B. Robertson and T.E. GlimerJr, Physical Review B, 5, 3111 (1971).
D. Labrie, T. Timusk and M.L. Thewalt, Phys. Rev. Lett. 52, 81 (1984).
M.O. Henry, E.C. Lightowlers, N. Killoran, D.J. Dunstan and B.C. Cavenett, J. Phys. C: Solid State Physics, 14, L255 (1981).
M.L.W. Thewalt, S.P. Watkins, U.O. Ziemelis, E.C. Lightowlers and M.O. Henry, Solid State Comm. 44, 573 (1982).
N. Killoran, D.J. Dunstan, M.O. Henry, E.C. Lightowlers and B.C. Cavenett, J.Phys C: Solid State Phys, 15, 6067 (1982).
M.O. Henry, Keith A. Moloney, J. Treacy, F.J. Mulligan and E.C. Lightowlers, J. Phys. C: Solid State Phys. 17, 6245 (1984).
Gordon Davies and Martin Henry, private communication.
J.B. Robertson and R.K. Franks, Solid State Communications, 6, 825 (1968).
M. Kleverman and H.G. Grimmeiss, Semicond. Sci. Technol. 1, 45 (1986).
Sverre Froyen and Alex Zunger, Phys. Rev. B 34, 7451 (1986).
Eugen Tarnow, S.B. Zhang, K.J. Chang and D.J. Chadi, Phys. Rev. B, to be published.
Gordon Davies, J. Phys. C. 17, 6331 (1984).
{The local mode frequencies for the isolated defects were obtained by assuming that the surrounding Si atoms do not move appreciably. This is justifyable since the Be atom is lighter than the Si atom by a factor of 3. The Be atoms then moved in a tetrahedrally symmetric potential and the frequencies reported are associated with the lowest eigenmode. We performed a test calculation for the substitutional defect allowing one of the Si atoms to move. We found that this changed the local mode frequency by 20 cm-1}.
{Again we approximated the surrounding lattice to be stationary. This should be a good approximation for the antisymmetric state (the effective mass is low), but worse for the symmetric state which has a high effective mass}.
{These estimates were calculated as follows: The upper bound of 0.8 eV was calculated assuming that the atomic coordinates in the configurations in between the local minima were simple linear interpolations. Thus the Si atoms were frozen and the Be atom was not allowed its most favorable path. Then we recalculated the energy barrier by allowing full relaxations of all the surrounding Si atoms. This adiabatics' energy was found to be 0.4 eV and is too low, because the movement of the Be atom is not a fully adiabatic process}.
J.J. van Kooten, G.A. Weller, and C.A.J. Ammerlaan, Phys. Rev. B 30, 4564 (1984); J. J. van Kooten, Ph.D. Thesis, Amsterdam (1987) and A. Chantre and D. Bois, Phys. Rev. B31, 7979 (1985).
For a theoretical treatment see Matthias Scheffler, Festkörperprobleme 29, 231 (1989).
Acknowledgement
This work was supported in part by the Office of Naval Research through Contract No. N00014-82-C-0244
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Tarnow, E., Zhang, S.B., Chang, K.J. et al. Peculiar Do** Behavior of Si:Be.. MRS Online Proceedings Library 209, 119–124 (1990). https://doi.org/10.1557/PROC-209-119
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DOI: https://doi.org/10.1557/PROC-209-119