Hostname: page-component-76fb5796d-2lccl Total loading time: 0 Render date: 2024-04-26T08:19:09.760Z Has data issue: false hasContentIssue false
  • English
  • Français

In-Situ Measurements of Islanding and Strain Relaxation of Ge/Si(111)

Published online by Cambridge University Press:  10 February 2011

P. W. Deelman ,
L. J. Schowalter  and
T. Thundat
P. W. Deelman
Affiliation:
Rensselaer Polytechnic Institute, Troy, NY 12180 {pdeelman, schowalt}@unix.cie.rpi.edu
L. J. Schowalter
Affiliation:
Rensselaer Polytechnic Institute, Troy, NY 12180 {pdeelman, schowalt}@unix.cie.rpi.edu
T. Thundat
Affiliation:
Oak Ridge National Laboratory, Oak Ridge, TN 37831ugt@ORNL.GOV
Get access

Abstract

We have measured strain relaxation and islanding in Ge films grown by molecular beam epitaxy on Si(111) at substrate temperatures between 450°C and 700°C in real time with reflection high energy electron diffraction (RHEED). At 450°C, we observe an oscillation of the surface lattice parameter for the first three bilayers (BL), followed by a sharp 2D–3D growth mode transition, when transmission diffraction features appear in RHEED. The surface lattice parameter then begins to relax at an initial rate of about 0.5%/BL. The mechanisms of island growth and strain relaxation change with growth temperature. At 500°C the surface lattice parameter begins to relax after only 1BL; at 550°C relaxation begins immediately. However, 3D spots do not appear until after 3.5BL at either temperature. The initial rate of strain relaxation decreases with increasing temperature until, at 700°C (when 3D spots never appear), it is only 0.04%/BL. This behavior may be explained by a temperature-dependent roughness length scale, as well as by differences in dislocation nucleation at low and high temperatures. At low temperature, atomic force microscope images show the development of small (1000Å), faceted islands with aspect ratios (height/width) on the order of 0.07. The formation of well-defined facets is inhibited at higher temperatures. At 700°C, islands grow very large (lμm) from the outset, with aspect ratios less than 0.015. These islands cannot thicken much, because dislocations can glide in easily at their edges. The islands grow laterally quickly, and the strain in the “new” islands is not substantially less than that in the “old.” At 700°C, 28% of the Ge/Si misfit strain may be relieved by diffusion.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 441: Thin Films – Structure and Morphology , 1996 , 373
Copyright
Copyright © Materials Research Society 1997

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

[1] Hammar, M., LeGoues, F.K., Tersoff, J., Reuter, M.C., and Tromp, R.M., Surf Sci., 349, p. 129 (1996).Google Scholar
[2] LeGoues, F.K., Hammar, M., Reuter, M.C., and Tromp, R.M, Surf. Sci., 349, p. 249 (1996).Google Scholar
[3] Sakamoto, T., Sakamoto, K., Miki, K., Okumura, H., Yoshida, S., and Tokumoto, H. in Kinetics of Ordering and Growth At Surfaces, edited by Lagally, M.G., (Plenum Press, 1990).Google Scholar
[4] Hida, , Tamagawa, , Ueba, , and Tatsuyama, , J. Appl. Phys., 67, p. 7274 (1990).Google Scholar
[5] Ichimura, M., Usami, A., Wakahara, A., and Sasaki, A., J. Appl. Phys., 77, p. 5144 (1995).Google Scholar
[6] Schell-Sorokin, A.J. and Tromp, R.M., Surf. Sci., 319, p. 110 (1994).Google Scholar
[7] Williams, et at. Phys. Rev. B, 43, p. 5001 (1991).Google Scholar
[8] Macdonald, J.E., Thornton, J.M.C., Williams, A.A., Ashu, P., Matthai, C.C., Vegt, H.A. van der, and Vlieg, E., Scanning Microscopy, 7, p. 497 (1993).Google Scholar
[9] Gossmann, H.-J., Bean, J.C., Feldman, L.C., McRae, E.G., and Robinson, I.K., Phys. Rev. Lett., 55, p. 1106 (1985).Google Scholar
[10] Matthews, J.W. and Blakeslee, A.E., J. Cryst. Growth, 27, p. 118 (1974).Google Scholar
[11] Matthews, J.W. and Blakeslee, A.E., J. Cryst. Growth, 32, p. 265 (1974).Google Scholar
[12] Whaley, and Cohen, , Appl. Phys. Lett., 57, p. 144 (1990).Google Scholar
[13] Massies, J. and Grandjean, N., Phys. Rev. Lett., 71, p. 1411 (1993).Google Scholar
[14] Srolovitz, D.J., Acta. Metall., 37 p. 621 (1989).Google Scholar
[15] Yang, W.H. and Srolovitz, D.J., Phys. Rev. Lett., 71 p. 1593 (1993).Google Scholar
[16] Mullins, W.W., J. Appl. Phys., 28 p. 333 (1957).Google Scholar
[17] Tersoff, J. and LeGoues, F.K., Phys. Rev. Lett., 72 p. 3570 (1994).Google Scholar
[18] Baribeau, J.-M., J. Cryst. Growth, 157 p. 52 (1995).Google Scholar
[19] Cullis, A.G., Robbins, D.J., Barnett, S.J., and Pidduck, A.J., J. Vac. Sci. Technol., A12 p. 1924 (1994).Google Scholar
[20] Jesson, D.E., Pennycook, S.J., Baribeau, J.-M., and Houghton, D.C., Phys. Rev. Lett., 71, p. 1744 (1993).Google Scholar
[21] Cullis, A.G., Pidduck, A.J., and Emeny, M.T., Phys. Rev. Lett., 75 p. 2368 (1995).Google Scholar
[22] Persans, P.D., Deelman, P.W., Stokes, K.L., Schowalter, L.J., Byrne, A., and Thundat, T., submitted to Appl. Phys. Lett. Google Scholar
[23] Deelman, P.W., Schowalter, L.J., and Thundat, T., Mat. Res. Soc. Symp. Proc., 399 p. 295 (1996).Google Scholar