J. Phys. I France
Volume 4, Numéro 9, September 1994
Page(s) 1309 - 1324
DOI: 10.1051/jp1:1994190
J. Phys. I France 4 (1994) 1309-1324

Influence of kinetic roughening on the epitaxial growth of silicon

J. Chevrier, A. Cruz, N. Pinto, I. Berbezier and J. Derrien

CRMC2 CNRS, Campus de Luminy, case 913, 13288 Marseille Cedex 09, France

(Received 11 February 1994, revised 17 May 1994, accepted 7 June 1994)

The low temperature homoepitaxial growth of silicon has been probed in situ by Reflection High Energy Electron Diffraction (RHEED) in a Molecular Beam Epitaxy (MBE) chamber in the temperature range 250  $^{\circ}$C-400  $^{\circ}$C. The continuous change in the RHEED patterns during the growth of thick films (several hundred angstroms) shows the progressive appearance of a surface roughness during and after the decay of RHEED oscillations. This is a clear evidence for kinetic roughening in the case of silicon epitaxial growth ai low temperatures on the Si(l 11) face. The surface width, $\alpha$, measured as the film thickness, h, is increased, can be described by $\alpha (h, T) \sim Ah~{\rm exp} (E_f/kT)$ with $E_f \sim 0.65$ eV. This is in marked difference with the kinetic roughening behavior measured during the growth of a metal like iron by means of the same RHEED technique (see Chevrier et al., Europhys. Lett. 8 (1991) 737). Furthermore, an extrapolation of this behavior to epitaxial growths at higher temperatures ( $T \sim 600~^{\circ}$C-800  $^{\circ}$C) suggests an effective influence of kinetic roughening in the determination of growth temperatures generally used for silicon MBE (i.e. the empirical usual growth temperatures $T_{\rm cpi} \sim 650~^{\circ}$C). During growth at substrate temperatures between 250  $^{\circ}$C and 400  $^{\circ}$C, the nucleation of misoriented silicon islands takes place following the occurrence of kinetic roughening at the surface. In this range of temperatures, this suggests that the loss of epitaxy occurs on a rough surface through the proliferation of defects and of misoriented crystals.

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