Theoretical study of dislocation nucleation from simple surface defects in semiconductors

Julien Godet (1) , Laurent Pizzagalli (1) , Sandrine Brochard (1) , Pierre Beauchamp (1)

1 LMP [Poitiers] - Laboratoire de métallurgie physique

Large-scale atomistic calculations, using empirical potentials for modeling semiconductors, have been performed on a stressed system with linear surface defects like steps. Although the elastic limits of systems with surface defects remain close to the theoretical strength, the results show that these defects weaken the atomic structure, initializing plastic deformations, in particular dislocations. The character of the dislocation nucleated can be predicted considering both the resolved shear stress related to the applied stress orientation and the Peierls stress. At low temperature, only glide events in the shuffle set planes are observed. Then they progressively disappear and are replaced by amorphization/melting zones at a temperature higher than 900 K.

Domains: Materials Science [cond-mat.mtrl-sci]; Other [cond-mat.other]

Julien Godet, Laurent Pizzagalli, Sandrine Brochard, Pierre Beauchamp. Theoretical study of dislocation nucleation from simple surface defects in semiconductors. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2004, 70 (5), pp.054109. ⟨10.1103/PhysRevB.70.054109⟩. ⟨hal-00170983⟩