Strained semiconductor structures: simulation of the first stages of the growth

• Published in: Surface science Vol. 276; no. 1; pp. 109 - 121
• Main Authors: Rouhani, M.Djafari, Gué, A.M., Sahlaoui, M., Estève, D.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.10.1992; Amsterdam Elsevier Science; New York, NY
• Subjects: Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Physics; Solid surfaces and solid-solid interfaces; Surface and interface dynamics and vibrations; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Cadmium Tellurides; Crystal growth; Gallium Arsenides; Monte Carlo method; Semiconductor materials; Strain energy; Mismatch lattice; Force field; Epitaxial film; Experimental study; Inorganic compound
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/0039-6028(92)90700-G

Atomic scale simulation of heteroepitaxial growth has been performed and results of its initial stages reported. The simulation is based on a Monte Carlo technique and uses the valence force field approximation to express the stress energy. The strain is determined by energy minimization, and the stress is assumed to enhance atomic motions on the substrate. The case of CdTe/GaAs with 14% lattice mismatch has been particularly studied. It is shown that strain and stress are mainly confined within the cluster boundaries. By extrapolating the results, critical thicknesses for the defect formation have been evaluated and compared with experimental data. Moreover, simulations show the formation of extended defects by diffusion and accumulation of point defects. Finally, at high lattice mismatches, it is observed that a deposited layer on a (100) oriented substrate has a strong and temperature dependent tendency to grow in (111) direction.