Enhanced intermixing in Ge nanoprisms on groove-patterned Si(1 1 10) substrates

Chen, G.; Vastola, G.; Zhang, J. J.; Sanduijav, B.; Springholz, G.; Jantsch, W.; Schäffler, F.

doi:10.1063/1.3541788

Cited by 6 publications

(4 citation statements)

References 22 publications

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“…2 Among the latter, the (1 1 10) vicinal surface has recently attracted significant interest due to studies showing the self-assembly of (105) bounded one-dimensional nanoripples upon deposition of SiGe alloys on Si (1 1 10). [3][4][5][6] While the formation of similar ripples has been observed on stripe-patterned substrates, 7,8 deposition on unpatterned (1 1 10) substrates results in a uniform rippling across the entire substrate surface. 9 Hence, self-assembled ripples formed on (1 1 10) substrates can themselves be used as sub-lithographic templates for either the ordered nucleation of three-dimensional islands 10 or exploited as nanowires 11 with potentially appealing optoelectronic properties.…”

Section: Introductionmentioning

confidence: 90%

Stability of Ge on Si (1 1 10) surfaces and the role of dimer tilting

2012

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Using both density functional theory-local density approximation and Tersoff potentials, we calculate (1 1 10), (105), and (001) surface energies relevant to the self-assembly of Ge {105} ripples on Si (1 1 10) substrates. Surface energies are calculated as a function of Ge overlayer thickness and applied strain. Comparison of density functional theory (DFT) and Tersoff potential results reveals qualitative differences in the predicted dependence of surface energies on Ge overlayer thickness and the stability of the Ge on Si (1 1 10) surface relative to the Ge on Si (001) surface. DFT calculations show that γ (1110) Ge/Si is strongly influenced by the presence of tilted dimers, and provide an explanation for the differing stability predictions. Finally, a multiscale model including strain-and thickness-dependent γ Ge/Si is used to show that surface energy is a driving force for formation of Ge {105} ripples on Si (1 1 10), supporting recent experimental results of Ge-deposition-induced {105} faceting on Si (1 1 10).

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Section: Introductionmentioning

confidence: 90%

Stability of Ge on Si (1 1 10) surfaces and the role of dimer tilting

2012

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“…The oxide-covered substrate regions between the stencil sites did not exhibit any Ge accumulation, providing for excellent fidelity in the transfer of the stencil pattern. These factors could make this method attractive for the production of Si-Ge islands with a Ge-rich stoichiometry, which provides a counterpoint to other patterning methods that promote silicon intermixing [55].…”

Section: Discussionmentioning

confidence: 99%

Modified Stranski–Krastanov growth in Ge/Si heterostructures via nanostenciled pulsed laser deposition

et al. 2012

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The combination of nanostenciling with pulsed laser deposition (PLD) provides a flexible, fast approach for patterning the growth of Ge on Si. Within each stencilled site, the morphological evolution of the Ge structures with deposition follows a modified Stranski-Krastanov (SK) growth mode. By systematically varying the PLD parameters (laser repetition rate and number of pulses) on two different substrate orientations (111 and 100), we have observed corresponding changes in growth morphology, strain and elemental composition using scanning electron microscopy, atomic force microscopy and μ-Raman spectroscopy. The growth behaviour is well predicted within a classical SK scheme, although the Si(100) growth exhibits significant relaxation and ripening with increasing coverage. Other novel aspects of the growth include the increased thickness of the wetting layer and the kinetic control of Si/Ge intermixing via the PLD repetition rate.

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“…III B. In experiments the distribution of intermixed islands observed is typically nonhomogeneous [8,44,59,60], but it has been proven that the three-dimensional concentration profile obtained is the one minimizing the elastic energy [23,61,62].…”

Section: Alloys and Nonhomogeneous Concentrationmentioning

confidence: 99%

Interpolating function of the strain relief of epitaxial quantum dots via an alternative morphological descriptor

Scopece

2015

Phys. Rev. B

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Assessing the equilibrium morphologies of self-assembled heteroepitaxial quantum dots requires the estimation of their elastic (volumetric), surface, and edge energy contribution, all of them being shape dependent. Due to the size and multifaceted morphology of these islands, the estimation of the first term is typically a time-consuming or complicated task. A general rule to predict it from the sole morphologies would guarantee a precious advantage in this field. Here we present an interpolating function to fulfill this purpose for the prototypical systems of Ge/Si and InAs/GaAs. The trend is first extracted from a systematic analysis of realistic shapes observed on (001) substrates. It is then tested and corroborated for selected vicinal (tilted) substrates. Finally, the deviations due to intermixing and the underlying wetting layer are quantified. Of fundamental importance in this process is the identification of a morphological descriptor more accurate than the widely adopted aspect ratio, the limitations of which are discussed.

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Enhanced intermixing in Ge nanoprisms on groove-patterned Si(1 1 10) substrates

Cited by 6 publications

References 22 publications

Stability of Ge on Si (1 1 10) surfaces and the role of dimer tilting

Stability of Ge on Si (1 1 10) surfaces and the role of dimer tilting

Modified Stranski–Krastanov growth in Ge/Si heterostructures via nanostenciled pulsed laser deposition

Interpolating function of the strain relief of epitaxial quantum dots via an alternative morphological descriptor

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