The Role of Native Oxide on the Mechanical Behavior of Silicon Nanowires

Nanomechanical Modeling of the Bending Response of Silicon Nanowires

“…19,20,35 Similar reduction in the ultimate strength is estimated to be up to 20%. 19,20,35 (ii) Appropriate interatomic potentials for atomistic simulations of surface stress and surface elasticity have to be introduced. 19,35,39 In this regard, surface stress is defined as the reversible work per unit area needed to elastically stretch a pre-existing surface.…”

“…34 Atomistic simulations also exhibit a reduction in the modulus of elasticity of Si NWs to be as much as 40% due to native oxide surface condition while compared to the pristine surface state. 19,20,35 Similar reduction in the ultimate strength is estimated to be up to 20%. 19,20,35 (ii) Appropriate interatomic potentials for atomistic simulations of surface stress and surface elasticity have to be introduced.…”

“…21,23,27−33 The lack of such a sound modeling approach is in fact reflected by a series of conflicting observations including broad range of estimations for elastic and strength properties 1,12 and significant differences between experimental and computational findings. 1,12,18,19,19,20,34,35 Models usually suffer from a poor description of surfacerelated phenomena 18,20,36 and inconsistent use of constitutive surface models as well as nonlinear elasticity. 1,18,36 In this context, an effective model should involve the implementation of the following three sets of parameters:…”

“…(i) Native oxide, essentially amorphous silicon dioxide (aSiO 2 ), is an indispensable part of the Si NW surface 19,20,34,35 and thus affects the NW structure by introducing defects or other interfaces. 37,38 Although usually overlooked, a recent study has revealed tensile intrinsic stresses in Si NWs upon native oxide formation under ambient conditions.…”

“…19,20,35 (ii) Appropriate interatomic potentials for atomistic simulations of surface stress and surface elasticity have to be introduced. 19,35,39 In this regard, surface stress is defined as the reversible work per unit area needed to elastically stretch a pre-existing surface. 20,39 Surface elastic constants represent the variation in bulk elastic constants due to the formation of a surface.…”