Near-surface stresses in silicon(001)

Delph, T. J.

doi:10.1016/j.susc.2007.10.014

Cited by 8 publications

(7 citation statements)

References 18 publications

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“…Despite the differences between the atomistic approaches, the surface elastic constants for unreconstructed (100) Si films also match well with Miller and Shenoy’s constants . Moreover, the surface stress constants obtained for unreconstructed (100) Si surface are in a good agreement with the predictions of prior FE studies. − …”

Section: Resultssupporting

confidence: 73%

“…The variation of surface properties is obtained with the evolution of stress and elastic components along the film thickness tracked. In this respect, calculated surface properties can be compared to those of previous studies on unreconstructed and oxidized Si thin films. ,,,− The surface stress and surface elastic constants calculated for unreconstructed (100) and (110) Si surfaces are in perfect agreement with prior MD ,,, and DFT reports modeled via different interatomic potentials. Despite the differences between the atomistic approaches, the surface elastic constants for unreconstructed (100) Si films also match well with Miller and Shenoy’s constants .…”

Section: Resultssupporting

confidence: 60%

“…The reason behind the present spread of stiffness and strength values in the literature can mainly be traced back to the lack of a proper theoretical treatment of surface mechanics. Despite numerous atomistic, ,,− density functional theory (DFT), ,,, finite element (FE), − and experimental studies on Si surface constants, a consensus on surface stress profiles and subsequent calculation of constants for different crystalline orientations and surface conditions is still missing. To quantify Si NW surface stress components, f 11 and f 22 , and surface elastic constants, d 11 and d 22 , in both (100) and (110), Martin’s method can be applied to the thin film structures of Figure .…”

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Nanomechanical Modeling of the Bending Response of Silicon Nanowires

Zare Pakzad,

Nasr Esfahani,

Tasdemir

et al. 2023

ACS Appl. Nano Mater.

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Understanding the mechanical behavior of silicon nanowires is essential for the implementation of advanced nanoscale devices. Although bending tests are predominantly used for this purpose, their findings should be properly interpreted through modeling. Various modeling approaches tend to ignore parts of the effective parameter set involved in the rather complex bending response. This oversimplification is the main reason behind the spread of the modulus of elasticity and strength data in the literature. Addressing this challenge, a surface-based nanomechanical model is introduced in this study. The proposed model considers two important factors that have so far remained neglected despite their significance: (i) intrinsic stresses composed of the initial residual stress and surface-induced residual stress and (ii) anisotropic implementation of surface stress and elasticity. The modeling study is consolidated with molecular dynamics-based study of the native oxide surface through reactive force fields and a series of nanoscale characterization work through in situ three-point bending test and Raman spectroscopy. The treatment of the test data through a series of models with increasing complexity demonstrates a spread of 85 GPa for the modulus of elasticity and points to the origins of ambiguity regarding silicon nanowire properties, which are some of the most commonly employed nanoscale building blocks. A similar conclusion is reached for strength with variations of up to 3 GPa estimated by the aforementioned nanomechanical models. Precise consideration of the nanowire surface state is thus critical to comprehending the mechanical behavior of silicon nanowires accurately. Overall, this study highlights the need for a multiscale theoretical framework to fully understand the size-dependent mechanical behavior of silicon nanowires, with fortifying effects on the design and reliability assessment of future nanoelectromechanical systems.

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Section: Resultssupporting

confidence: 73%

Section: Resultssupporting

confidence: 60%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Nanomechanical Modeling of the Bending Response of Silicon Nanowires

Zare Pakzad,

Nasr Esfahani,

Tasdemir

et al. 2023

ACS Appl. Nano Mater.

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“…In recent articles, Delph [45] and, separately, Chen [35] derived thermomechanical expressions following Hardy's formalism but assuming a three-body potential. Subsequent to that work, Delph [46] utilized similar expressions to evaluate surface stress distribution for reconstructed Si surfaces. In that work, the effect of a surface step on stress was quantitatively analyzed.…”

Section: Calculating Stress In Atomic Simulationsmentioning

confidence: 99%

Reconsideration of Continuum Thermomechanical Quantities in Atomic Scale Simulations

Webb

Zimmerman

Seel

2008

Mathematics and Mechanics of Solids

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As motivation builds to consider mechanics of nanometer scale objects, it is increasingly advantageous to implement models with finer resolution than standard continuum approaches. For such exercises to prove fruitful, these models must be able to quantify continuum thermomechanical quantities; furthermore, it may be necessary to do so on a sub-system level in order to assess gradients or distributions in a given property. Herein we review the calculation of stress, heat flux, and temperature in atomic scale numerical simulations such as the molecular dynamics method.

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“…Despite numerous studies employing atomistic [43,46,[57][58][59], DFT [44,[60][61][62], finite element [63][64][65][66][67], and experimental [68] approaches to investigate the surface con-stants of Si, a consensus regarding surface stress profiles and the subsequent calculation of constants for different crystalline orientations and surface conditions is lacking. A recent study has provided insights into the surface constants of unreconstructed and oxidized Si thin films offering valuable analysis regarding the surface properties of crystalline Si with different surface states [12].…”

Section: A Surface Properties Of Simentioning

confidence: 99%