First principles modelling of (100) H‐induced platelets in silicon

Abstract

We investigate possible structures of hydrogen-induced platelets in the (100) crystallographic plane in silicon using ab initio methods. We consider the structures of Si(100) external surfaces - the 2×1-reconstructed monohydride and the 1×1-reconstructed dihydride - as possible structures of hydrogen-induced platelets. We find that the 1×1 reconstructed dihydride-terminated structure has the lowest formation energy per hydrogen atom. Addition of H2 molecules to platelets makes the formation energies of platelets lower. We discuss the vacancy-based model of (100) platelet structures and compare the energies of (100) platelets with platelets in the (111) plane in silicon. Energies of hydrogen-induced platelets in (100) and (111) planes are found to be very similar. Therefore, we conclude that the preferred crystallographic orientation of platelets is not caused by thermodynamic stability but by kinetic reasons: wafer surface orientation and diffusion of hydrogen to platelets. © 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Nanoscale organization by elastic interactions between H and He platelets in Si

“…The curves representing the barrier of energy as a function of depth in the substrate for the formation energy of the three considered orientations of platelet are plotted in Fig. 2(b) by considering similar self-formation energies 19 for {111} and {001}-type orientations. According to this scenario, the nucleation of (001)-platelets would be preferentially observed all along the implanted layer.…”

Atomically Smooth Stress-Corrosion Cleavage of a Hydrogen-Implanted Crystal

“…In our implementation, a mobile and chemically active QM region, described by the density functional tight binding Hamiltonian [20], is seamlessly embedded into a larger system described by the Stillinger-Weber interatomic potential [21]. Consistent with experimental [4,5,22,23] and previous theoretical [24,25] studies, our platelet models are composed of two facing 10-nm-wide dihydride-terminated internal (100) Si surfaces obtained by either replacing an array of Si-Si bonds with Si-H=H-Si bonds [7,25,26] or substituting Si atoms from a (100) layer with terminating H atoms [24,27,28]. Each platelet is embedded in a bulk silicon matrix, leading to model system sizes of up to 35 000 atoms [Figs.…”

Evolution of implantation induced damage under further ion irradiation: Influence of damage type

“…Zhang and Jackson 74 found that the half-stacking fault structure was the lowest energy structure among them, though this platelet can be only built up with the presence of preexisting defects, such as vacancies or interstitials introduced by ion implantation. Martsinovich et al 75,76 investigated the effect of shear and dilation on energies of these platelet structures and concluded that the half stacking fault involving shear of the silicon lattice is stable at low dilations, and the structure with pairs of Si-H bonds in the shuffle plane and with H 2 molecules, which is stable at large dilation in either ͑111͒ or ͑100͒ platelets. For either of the above proposed platelet structures existing in hydrogen implanted Si, the shear of the silicon lattice and the effect of lattice dilation normal to platelets will be accompanied by atomic reconstruction of the Si atoms located at the core of the platelet.…”