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Picosecond Photocarrier Lifetimes in Ion-Irradiated Amorphous and Crystalline Silicon

Published online by Cambridge University Press:  28 February 2011

P. A. Stolk
Affiliation:
FOM-Institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ Amsterdam, the Netherlands
L. Calcagnile
Affiliation:
FOM-Institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ Amsterdam, the Netherlands
S. Roorda
Affiliation:
FOM-Institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ Amsterdam, the Netherlands
H. B. van Linden
Affiliation:
FOM-Institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ Amsterdam, the Netherlands
Van den Heuvell
Affiliation:
FOM-Institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ Amsterdam, the Netherlands
F. W. Saris
Affiliation:
FOM-Institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ Amsterdam, the Netherlands
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Abstract

Crystalline silicon (c-Si) and structurally relaxed amorphous silicon (a-Si) were implanted with 1 MeV Si+ at liquid nitrogen temperature. The photocarrier lifetime τ in the implanted samples was determined with sub-picosecond resolution through pump-probe reflectivity measurements. At low damage levels (i.e. <1014 ions/cm2), τ decreases with increasing ion dose in both materials, indicating a build up of trapping and recombination centers. The dominant centers in c-Si appear to be related to simple defects. The generation rate of electrically active defects is found to be the same in relaxed a-Si and c-Si, which suggests that the structural defects formed in a-Si strongly resemble the simple defects in c-Si. For ion doses > 1014 /cm2, τ saturates at a level of 0.8 ps for both materials. Strikingly, the saturation sets in far below the dose needed to amorphize (>1015 /cm2). The defect density in a-Si at saturation is estimated to be ≈1.6 at.%.

Type
Research Article
Copyright
Copyright © Materials Research Society 1992

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References

REFERENCES

1 Roorda, S., Sinke, W.C., Poate, J.M., Jacobson, D.C., Dierker, S., Dennis, B.S., Eaglesham, D.J., Spaepen, F., and Fuoss, P., Phys. Rev. B44. 3702(1991).Google Scholar
2 Stolk, P.A., Roorda, S., Calcagnile, L., Sinke, W.C., van Linden van den Heuvell, H.B., and Saris, F.W., Mat. Res. Soc. Symp. Proc. 205 (1991).Google Scholar
3 Stolk, P.A., Calcagnile, L., Roorda, S., Sinke, W.C., Berntsen, A.J.M., and van der Weg, W.F., Appl. Phys. Lett, (in press).Google Scholar
4 Roorda, S., Poate, J.M., Jacobson, D.C., Eaglesham, D.J., Dennis, B.S., Dierker, S., Sinke, W.C., and Spaepen, F., Solid State Commun. 75, 197 (1990).Google Scholar
5 The peak carrier density strongly depends on the absorption depth of 2 eV photons in the material, which ranges from ≈2(μm for unimplanted c-Si to ≈70 nm for as-implanted a-Si, from Fried, M., Lohner, T., Vizkelethy, G., Jároli, E., Mezey, G., and Gyuali, J., Nucl. Instrum. Methods B15, 422 (1986). However, for all samples the estimated peak carrier density is below 2×1018/cm3.Google Scholar
6 Doany, F.E., Grischkowsky, D., and Chi, C.-C., Appl. Phys. Lett. 50, 460 (1987).CrossRefGoogle Scholar
7 Because of the large absorption depth in lightly damaged c-Si (≈2 μm), carriers might be generated beyond the damage region of the implant. However, since τ in the unimplanted substrate is expected to be large (»1 ns), the observed transient in the pump-probe measurements fully reflects the carrier decay in the implanted region.Google Scholar
8 Tsu, R., Hernandez, J.G., and Pollak, F.H., Solid State Commun. 54, 447 (1985).Google Scholar
9 Calcagnile, L., Stolk, P.A., and Saris, F.W. (unpublished).Google Scholar
10 Esser, A., Kütt, W., Strahnen, M., Maidorn, G., and Kurz, H., Appl. Surf. Sci. 46, 446 (1990).CrossRefGoogle Scholar
11 Pantelides, S. T., Rev. Mod. Phys. 50, 797 (1978).Google Scholar
12 Street, R.A., Philos. Mag. B49, L15 (1984).Google Scholar
13 Johnson, A.M., Auston, D.H., Smith, P.R., Bean, J.C., Harbison, J.P., and Adams, A.C., Phys. Rev. B23, 6816 (1981).Google Scholar
14 Vardeny, Z., Strait, J., and Tauc, J., Appl. Phys. Lett. 42, 580 (1983).CrossRefGoogle Scholar
15 Fauchet, P.M., Hulin, D., Migus, A., Antonetti, A., Kolodzey, J., and Wagner, S., Phys. Rev. Lett. 57, 2438 (1986).Google Scholar
16 Chu, W.-K., Mayer, J. W., Nicolet, M.-A., Backscattering Spectrometry (Academic Press, New York, 1978), p. 239 ff.Google Scholar
17 Biersack, J.P. and Haggmark, L.J., Nucl. Instr. Meth. 174, 257 (1980).Google Scholar
18 Sigmund, P., Appl. Phys. Lett. 14, 114 (1969).Google Scholar
19 Baude, P.F., Tamagawa, T., and Polla, D.L., Appl. Phys. Lett. 57, 2579 (1990).Google Scholar
20 Coffa, S., Poate, J.M., Jacobson, D.C., and Polman, A., Appl. Phys. Lett. 58, 2916 (1991).Google Scholar
21 Spitzer, W.G., Hubler, G.K., and Kennedy, T.A., Nucl. Instrum. Methods 209/210, 309 (1983).Google Scholar