MBE growth conditions for Si island formation on Ge (001) substrates

• Published in: Thin solid films 2008-11, Vol.517 (1), p.62-64
• Main Authors: Pachinger, D., Lichtenberger, H., Chen, G., Stangl, J., Hesser, G., Schäffler, F.
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Growth kinetics; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Molecular, atomic, ion, and chemical beam epitaxy; Ordered islands; Physics; Self-assembled; Solid-fluid interfaces; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Theory and models of film growth; Thin film structure and morphology; Wetting
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2008.08.152

The epitaxial growth conditions for silicon on germanium substrates were investigated as a function of growth temperature and epilayer thickness. 3D Stranski–Krastanow growth was observed in a temperature range from 400 to 750 °C, although strong alloying with the substrate occurred for the highest temperatures. At a lower growth temperature alloying is reduced. For the growth at 550 °C island formation takes place only after a wetting layer thickness of about 14 monolayers. With decreasing temperature the wetting layer thickness shifts to lower Si coverages. Nevertheless, the equilibrium critical thickness for dislocation formation in the wetting layer is reached for temperatures down to 450 °C. Partial ordering of the islands along oriented lines could be seen at higher Si coverages, which is most likely caused by ordering along misfit dislocation segments.