A Monte Carlo investigation of growth and characterization of heteroepitaxial thin films N. Fazouan a, ⁎, E. Atmani b , M. Djafari Rouhani c,d , A. Esteve c,d a Laboratoire de Physique et de Mécanique des Matériaux, Faculté des Sciences et Techniques, B.P. 523, 23000 Béni Mellal, Morocco b Laboratoire de la matière condensée, Faculté des Sciences et Techniques, B.P. 146, 20650, Mohammedia, Morocco c CNRS; LAAS; 7 avenue du colonel Roche, F-31077 Toulouse, France d Université de Toulouse; UPS, INSA, INP, ISAE; LAAS; F-31077 Toulouse, France abstract article info Available online 24 February 2009 Keywords: Kinetic Monte Carlo simulation Heteroepitaxial growth Roughness RHEED Photoemission Dislocations We investigate the growth of mismatched thin films by a kinetic Monte Carlo computer simulation and including a local photoemission model with reflection high-energy electron diffraction (RHEED) intensity for comparison. The strain is introduced through an elastic energy term based on a valence force field approximation. We describe an atomistic mechanism for dislocation nucleation during first stage of GaSb/ GaAs (001) growth and in situ variations of photoemission current (PE) and RHEED intensity are reported. We have shown the formation of grooves corresponding to (111) facets, a precursor to the formation of misfit defects. The surface roughening and facetting by creation of grooves explain the absence of photoemission and RHEED oscillations in accordance with experimental observations [J.J. Zinck and D.H. Chow, J. Cryst. Growth,175/176 (1997) 323, J.J. Zinck and D.H Chow, Appl. Phys. Lett. 66 (1995) 3524]. © 2009 Elsevier B.V. All rights reserved. 1. Introduction The heteroepitaxial growth of lattice mismatched materials has been extensively investigated during recent years, both on theoretical and experimental grounds. The reason is that large strain energies develop in the layer from the first stages of the growth. The relaxation of the strain energy combined with the kinetics of atomic motions on the surface then leads to the various morphologies observed experimentally. An atomistic understanding of the processes control- ling the quality of the interface formed under MBE growth conditions is of extreme importance. The Solid On Solid model [3], was the guideline for the first simulations during the past decades. In an effort to develop this approach, Madhukar and Ghaisas [4] have introduced, in the eighties, the essential features by introducing atomic surface reactivity and studying the influence of the local configurations on the growth rate incorporation. The simulations presented in this paper differ from the previous models in two very important aspects. The first involves the interactions between atoms in interstitial sites, considered as intermediate configurations for interlayer migrations, leading to the faceting behaviour. The second aspect takes into account the deformation of structures and their effects: strains generated at the interface, their relaxation and the creation of point defects. The interesting example presented here is the GaSb/GaAs (001) growth presenting a large lattice mismatch of 8% and characterized by large island formation [5] with the presence of stacking faults associated with dislocations [5,6] in most of them. To study in situ, the dynamic MBE growth of GaSb on GaAs, we have used our theoretical model of photoemission oscillations (PE) [7,8] and reflection high-energy electron diffraction (RHEED) intensity. Experimentally, the effect of lattice mismatch parameter on the oscillations of photoemission current was studied by Zinck and Chow [1] in the case of the quantum well AlSb/GaSb/AlSb deposited on (001) GaAs and InAs substrates. As seen on Fig. 1 , the oscillations of photoemission current are absent during growth of the quantum well on GaAs substrate (Fig. 1a), but quite clear during growth on InAs substrate (Fig. 1b). The authors also showed a roughness front profile of films deposited on GaAs compared with those deposited on InAs substrate. These observations are attributed to the presence of dislocations and of defects in the interface between GaSb and GaAs due to the important mismatch between GaSb and GaAs (8%) compared with that between GaSb and InAs that is of 1%. The purpose of this paper is to display the effect of lattice mismatch parameter on the oscillations of photoemission current and to study the first stage of GaSb/GaAs (001) growth to describe the Thin Solid Films 517 (2009) 6260–6263 ⁎ Corresponding author. Tel.: +212 23 48 5122; fax: +212 23 48 52 01. E-mail addresses: fazouan@yahoo.fr, nfazouan@fstbm.ac.ma (N. Fazouan). 0040-6090/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.tsf.2009.02.097 Contents lists available at ScienceDirect Thin Solid Films journal homepage: www.elsevier.com/locate/tsf