Misfit Dislocations in Epitaxial Heterostructures: Mechanisms of Generation and Multiplication

Computer simulation of the vacancy defects interaction with shuffle dislocation in silicon

“…The high vacancy concentration in LT-Si may lead to an intensive vacancy migration from the LT-Si buffer layers into the SiGe epitaxial layers [26,27]. According to the results obtained in this work and the concept proposed by Kasper et al [12], the vacancies in SiGe layers, most of which are assumed to have a configuration of divacancies, may cause dislocations to climb.…”

Misfit stress relaxation in composite nanoparticles

“…4(a) can be used for estimating the critical thickness h cr of the shell, such as for h < h cr , the misfit dislocation loop is not energetically favorable, while for h > h cr , it is. The critical thickness of an epitaxial film is one of basic parameters used in characterization of planar epitaxial heterostructures (Beanland et al, 1996;Fitzgerald, 1991;Freund & Suresh, 2003;Gutkin et al, 1993;Jain et al, 1990Jain et al, , 1997Matthews, 1979;Van der Merwe, 1991;Vdovin, 1999;Vladimirov et al, 1988).…”

“…For example, the misfit strain, which is a special type of residual strains caused by the difference in lattice parameters of crystals in contact, changes the energy gap in semiconductor nanoparticles (quantum dots) embedded in epitaxial layers (Andreev & O'Reilly, 2000;Bimberg, Grundmann, & Ledentsov, 1996;Peng et al, 2005), thus modifying the electronic and optical properties of light-emitting devices (injection lasers and light-emitting diodes) on quantum dots. On the other hand, the residual strains and stresses in CNPs can relax through generation of various defects, in particular, misfit dislocations as is the case with planar heteroepitaxial structures (Beanland, Dunstan, & Goodhew, 1996;Fitzgerald, 1991;Freund & Suresh, 2003;Gutkin, Kolesnikova, & Romanov, 1993;Jain, Willis, & Bullough, 1990;Jain, Harker, & Cowley, 1997;Matthews, 1979;Van der Merwe, 1991;Vdovin, 1999), nanoislands on substrates (Chen et al, 1996;Gatti, Marzegalli, Zinovyev, Montalenti, & Miglio, 2008;Liu, Ross, & Schwarz, 2000;Ovid'ko & Sheinerman, 2006;Wang et al, 2011;Zou, Liao, Cockayne, & Jiang, 2002), quantum dots Chaldyshev, Bert, Kolesnikova, & Romanov, 2009;Kolesnikova & Romanov, 2004a, 2004bKolesnikova, Romanov, & Chaldyshev, 2007;Ovid'ko & Sheinerman, 2006) and wires (Gosling & Willis, 1995;Gutkin, Ovid'ko, & Sheinerman, 2003;Ovid'ko & Sheinerman, 2006) in epitaxial layers, core-shell (Aifantis, Kolesnikova, & Romanov, 2007;Gutkin, Ovid'ko, & Sheinerman, 2000;Goldthorpe, Marshall, & McIntyre, 2008;Kavanagh, 2010;Sheinerman & Gutkin, 2001;Ovid'ko & Sheinerman, 2006…”

Strain relaxation of GeSi/Si(001) heterostructures grown by low-temperature molecular-beam epitaxy

“…40,41 The density of such centers is usually insufficient for a complete plastic relaxation of the stressed film, and the mechanisms of secondary generation (multiplication) of misfit dislocations 38,39 start to operate when the film reaches a certain critical thickness.…”