Crystallographic tilting of heteroepitaxial layers

Ayers, J. E.; Ghandhi, S. K.; Schowalter, L. J.

doi:10.1016/0022-0248(91)90077-i

Cited by 196 publications

(72 citation statements)

References 20 publications

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“…Research on tilt relaxation for strained layers on off-cut growth surfaces has been reported by a number of authors. 15,16 Assuming a pre-existing network of threading dislocations in the epitaxial layer, glide-limited tilt relaxation models have been developed to predict the amount of tilt relaxation that will occur in a mismatched off-cut film. Tilt relaxation on off-cut surfaces has been predicted to be maximized for growth conditions that maximize dislocation glide along the available asymmetric slip systems, namely high growth temperatures and small relative mismatch strains.…”

Section: Resultsmentioning

confidence: 99%

CdZnTe graded buffer layers for HgCdTe/Si integration

Groenert

Markunas

2006

Journal of Elec Materi

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Section: Resultsmentioning

confidence: 99%

CdZnTe graded buffer layers for HgCdTe/Si integration

Groenert

Markunas

2006

Journal of Elec Materi

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“…In the previous section the first and second InP 1-y As y buffers were found to be nearly fully relaxed due to the efficient relief of the relative misfit strains of ∆ε misfit = +0.54% and +0.33% in these layers. As discussed in reference [13], layer tilt in non- FWHM 400 with respect to the group III and group V crystalline faces suggests that there is in fact an anisotropy in the overall densities/distibutions of α and β type dislocations which influences the crystalline structure in the active TPV layer. Open circuit voltage degradation in crystalline photovoltaic materials often results from a reduction in minority carrier lifetime due to the presence of electrically active crystalline defects.…”

Section: Reciprocal Space Mapping (Rsm)mentioning

confidence: 91%

Triple-axis X-ray Reciprocal Space Mapping of In(y)Ga(1-y)As Thermophotovoltaic Diodes Grown on (100) InP Substrates

Dashiell¹,

Ehsani²,

Sander³

et al. 2006

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“…where the film/substrate interface shows a low defect density, and only if competing mechanisms, such as misfit dislocations with inclined Burgers vectors, 7 do not dominate. Quantitative verification of the Nagai model has therefore remained elusive in oxide heteroepitaxy except for very thin films having a lattice parameter similar to that of the substrate (for example, 8 15 nm of SrRuO 3 on 4-miscut SrTiO 3 , resulting in a tilt of ~0.06).…”

Section: Main Textmentioning

confidence: 99%

Unit cell orientation of tetragonal-like BiFeO₃ thin films grown on highly miscut LaAlO₃ substrates

et al. 2013

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Synchrotron and lab-scale x-ray diffraction shows that tetragonal-like T'-BiFeO 3 films on miscut LaAlO 3 substrates ( < 5) exhibit (00l)-planes tilted away from those of the substrate as predicted by the "Nagai model" (except for miscut <0.2). Tilts as large as 1 are achieved even in 100 nm thick films, strikingly larger than those observed in other perovskites. We attribute this to the large c/a ratio and the high crystalline coherency of the T'-BiFeO 3 /LaAlO 3 interface. This coherency is possible through an observed "diagonal-on-diagonal" alignment. Interestingly, the substrate miscut does not influence the relative population of monoclinic domains. 2 Main textStrain engineering, i.e. the intentional modification of crystal structure, microstructure, and morphology of epitaxial thin films via the mismatch between the film's and the substrate's lattice parameter and symmetry, is a powerful tool to tune functional properties of materials. [1][2][3] Similarly, the presence of step edges on the substrate surface resulting from substrate miscut can also have a large impact on the microstructure of thin films, for example by breaking the four-fold surface symmetry of a (001)-oriented cubic substrate. Thus, for a film consisting of unit cells having a non-square in-plane lattice, the degeneracy between different in-plane film-substrate alignments may be lifted in an approach referred to as domain engineering. 4,5 Furthermore, a surface step locally results in a three-dimensional clamping of the film material instead of the biaxial stress experienced elsewhere. As a consequence of the resulting non-uniform strain in the out-of-plane direction, the (00l) planes of the film may become tilted with respect to those of the substrate. For the case of Ga x In 1-x As on GaAs, Nagai demonstrated 6 that simple geometrical arguments explain the observed tilting of the film planes by an angle  when grown on a substrate having a miscut angle , as shown in Fig. 1. In this simple model, the film out-of-plane lattice parameter is constrained to match the substrate at each step edge and then gradually relaxes to its unstrained value across the flat surface terrace. In fact, with out-of-plane lattice parameters for the film and substrate, c F and c S respectively, one expects tan / tan = (c F -c S )/c S , and thus a negative (positive) tilt if c F > c S (c F < c S ).Observing a tilt corresponding to this "Nagai model" is possible only in a system where the clamping in three dimensions is strong, i.e. where the film/substrate interface shows a low defect density, and only if competing mechanisms, such as misfit dislocations with inclined Burgers vectors, 7 do not dominate. Quantitative verification of the Nagai model has therefore remained elusive in oxide heteroepitaxy except for very thin films having a lattice parameter similar to that of the substrate (for example, 8 15 nm of SrRuO 3 on 4-miscut SrTiO 3 , resulting in a tilt of ~0.06). A much larger film/substrate tilt should be observed in a system with c F >> ...

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Crystallographic tilting of heteroepitaxial layers

Cited by 196 publications

References 20 publications

CdZnTe graded buffer layers for HgCdTe/Si integration

CdZnTe graded buffer layers for HgCdTe/Si integration

Triple-axis X-ray Reciprocal Space Mapping of In(y)Ga(1-y)As Thermophotovoltaic Diodes Grown on (100) InP Substrates

Unit cell orientation of tetragonal-like BiFeO₃ thin films grown on highly miscut LaAlO₃ substrates

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Crystallographic tilting of heteroepitaxial layers

Cited by 196 publications

References 20 publications

CdZnTe graded buffer layers for HgCdTe/Si integration

CdZnTe graded buffer layers for HgCdTe/Si integration

Triple-axis X-ray Reciprocal Space Mapping of In(y)Ga(1-y)As Thermophotovoltaic Diodes Grown on (100) InP Substrates

Unit cell orientation of tetragonal-like BiFeO3 thin films grown on highly miscut LaAlO3 substrates

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Unit cell orientation of tetragonal-like BiFeO₃ thin films grown on highly miscut LaAlO₃ substrates