INTERACTION BETWEEN THE 30° PARTIAL DISLOCATION AND HEX-VACANCY IN SILICON

The molecular dynamics (MD) method is used to investigate the interaction between the 30 degrees partial dislocation and hex-vacancy (V-6) in Si. The interaction processes are described in detail and compared with the prior results of mono-vacancy (V-1) and divacancy (V-2). It is found that dislocations are pinned by V-6 when the shear stresses are smaller than a definite critical value T-c. It illustrates that the encountered two segments beside vacant sites parallel each other or annihilate. Moreover, it is shown that the critical shear stress T-c is mainly determined by both the migration barrier of kink and the volume of vacancy. Although V-6 cannot make dislocations move faster due to the present small models, it may lower the dislocation density in certain conditions due to the pinning effect.