MOLECULAR DYNAMICS SIMULATION OF THE INTERACTION BETWEEN 30o PARTIAL DISLOCATION AND MONOVACANCY IN Si

Dislocation and monovacancy (V₁) are the fundamental defects in Si. The interaction between them is concerned with the electronic and optical properties of electronic devices. In this paper, the interactions of 30^o partial dislocation with V₁ in Si were investigated by the molecular dynamics simulation method based on the Stillinger–Weber (SW) potential. The simulations were conducted under different temperature and shear stress conditions. The results show that 30^o partial dislocation is pinned when dislocation encounters the V₁ under the conditions that shear stress is relatively low and the temperature is kept constant. When the shear stress increases to a critical value, the dislocation can overcome the pin and the V₁ is left in the crystal. As the temperature increases, the critical shear stress decreases approximately as a linear function. Moreover, the values of the critical shear stress corresponding to different dislocation kinks also show that the abilites of kinks to overcome the pin are determinded by the migration barriers of kinks. In comparison of the locations of dislocation core in two models with and without V₁, it is found that the V₁ can make the 30^o partial dislocation move faster once the dislocation glides away from the V_{1 .}