Thermally Activated Reorientation of Di-interstitial Defects in Silicon

Kim, Jeongnim; Kirchhoff, F.; Aulbur, Wilfried G.; Wilkins, John W.; Khan, F. S.; Kresse, Georg

doi:10.1103/physrevlett.83.1990

Cited by 58 publications

(57 citation statements)

References 16 publications

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“…[4][5][6][14][15][16][17][18][19][20][21][22] These studies have employed a broad range of theory to describe interatomic interactions, ranging from empirical potentials, 4,14,15 to tight binding, [16][17][18] to electronic density-functional theory ͑DFT͒. 5,6,[20][21][22][23] While there are some discrepancies between the various studies regarding the precise values and ordering of the predicted formation energies, some general conclusions can be drawn. First, it is clear that on a per-interstitial basis, and in the limit of infinite size, the formation energy of all ͕111͖ planar defects is lower than either ͕100͖ or ͕113͖ defects.…”

Section: Formation Thermodynamics For Self-interstitial Clusters-prevmentioning

confidence: 99%

Detailed microscopic analysis of self-interstitial aggregation in silicon. II. Thermodynamic analysis of single clusters

2010

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We analyze results generated by large-scale molecular-dynamics simulations of self-interstitial clusters in crystalline silicon using a recently developed computational method for probing the thermodynamics of defects in solids. In this approach, the potential-energy landscape is sampled with lengthy moleculardynamics simulations and repeated energy minimizations in order to build distribution functions that quantitatively describe the formation thermodynamics of a particular defect cluster. Using this method, a comprehensive picture for interstitial aggregation is proposed. In particular, we find that both vibrational and configuration entropic factors play important roles in determining self-interstitial cluster morphology. In addition to the expected role of temperature, we also find that applied (hydrostatic) pressure and the commensurate lattice strain greatly influence the resulting aggregation pathways. Interestingly, the effect of pressure appears to manifest not by altering the thermodynamics of individual defect configurations but rather by changing the overall energy landscape associated with the defect. These effects appear to be general and are predicted using multiple, well-tested, empirical interatomic potentials for silicon. Our results suggest that internal stress environments within a silicon wafer (e.g., created by ion implantation) could have profound effects on the observed selfinterstitial cluster morphology. We analyze results generated by large-scale molecular-dynamics simulations of self-interstitial clusters in crystalline silicon using a recently developed computational method for probing the thermodynamics of defects in solids. In this approach, the potential-energy landscape is sampled with lengthy molecular-dynamics simulations and repeated energy minimizations in order to build distribution functions that quantitatively describe the formation thermodynamics of a particular defect cluster. Using this method, a comprehensive picture for interstitial aggregation is proposed. In particular, we find that both vibrational and configuration entropic factors play important roles in determining self-interstitial cluster morphology. In addition to the expected role of temperature, we also find that applied ͑hydrostatic͒ pressure and the commensurate lattice strain greatly influence the resulting aggregation pathways. Interestingly, the effect of pressure appears to manifest not by altering the thermodynamics of individual defect configurations but rather by changing the overall energy landscape associated with the defect. These effects appear to be general and are predicted using multiple, well-tested, empirical interatomic potentials for silicon. Our results suggest that internal stress environments within a silicon wafer ͑e.g., created by ion implantation͒ could have profound effects on the observed selfinterstitial cluster morphology. Disciplines Biochemical and Biomolecular Engineering | Chemical Engineering | Engineering

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Section: Formation Thermodynamics For Self-interstitial Clusters-prevmentioning

confidence: 99%

Detailed microscopic analysis of self-interstitial aggregation in silicon. II. Thermodynamic analysis of single clusters

2010

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“…On the other hand, positively charged states might lower the diffusion barrier of the I 2 a by about 0.1 eV. 8 However, the charged states will not change the conclusion that the di-interstitial I 2 a can diffuse along all possible ͗111͘ directions with translation/rotation and reorientation steps.…”

Section: Discussionmentioning

confidence: 99%

“…Based on density-functional calculations, Kim et al 8 proposed a structure, I 2 a , for the di-interstitial defect in silicon and related its C 1h symmetry and the estimated 0.5 eV diffusion barrier to the experimental results for the P6 center. Moreover, Kim's results indicate that the I 2 a diffuses via a reorientation mechanism.…”

Section: Introductionmentioning

confidence: 99%

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Diffusion mechanisms for silicon di-interstitials

Hennig

Wilkins

2006

Phys. Rev. B

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Tight-binding molecular dynamics and density-functional simulations on silicon seeded with a di-interstitial reveal its detailed diffusion mechanisms. The lowest-energy di-interstitial performs a translation/rotation diffusion-step with a barrier of 0.3 eV and a prefactor of 11 THz followed by a reorientation diffusion step with a 90 meV barrier and a 2300 THz prefactor. The intermediate reorientation steps allow di-interstitials to diffuse isotropically along all possible ͗111͘ bond directions in the diamond lattice. The dominating diffusion barrier of 0.3 eV is not inconsistent with the experimental value of 0.6± 0.2 eV. In addition, this lowest energy di-interstitial may diffuse to neighboring sites through an intermediate structure which is the bound state of two single interstitials. The process in which migrating single interstitials combine into a di-interstitial is exothermic with almost zero energy barrier.

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“…The most recent calculations using first principles density methods employing Gaussian orbitals (Eberlein et al, 2001) or tight-binding molecular dynamics simulations (Cogoni et al, 2005;Kim et al, 1999;Posselt et al, 2005;Richie et al, 2004) point to a structure consisting of a center atom I 0 and dumbbell atoms I 1 À I 2 as shown in Fig. 22-K in which three atoms share the regular lattice site located at the origin of the axis, and the dumbbell is aligned parallel to the [110] direction.…”

Section: The Di-interstitialmentioning

confidence: 99%