Molecular Dynamics Simulation Of The 30 Degrees Dislocation In Silicon Crystal

In recent years, with the development of science and technology, particularly in the field of electronic technology, Si semiconductor increasingly harsh demands, in order to obtain a suitable quality of the materials we need. Molecular beam extention growth technology has received increasing attention .Si and Ge and SiGe heterojunction has wide research because of the wider use of the structure. So we try to understand the microscopic mechanism by molecular dynamics simulation methods,this is very meaningful.With the in-depth study of low-temperature Si buffer layer technology , the method for understanding the mechanism we know have been deepening. Through establishment various dislocations and vacancy defects and shortcomings of Reconstruction atomic arrangement configurations, then use molecular simulation methods to research the individual movements and their interactions, We found that 30 degrees dislocation movement is the key of the dislocation movement of SiGe heterojunction structure. The main content of this paper is through the method that establishment the model of 30 degrees dislocation of the atomic configuration, then impose the stress to 30 degrees dislocation , so we can obtain some sports properties of 30 degrees dislocation by computer simulation. We found that the movement of 30 degrees dislocation move with the kink pair through the research of dislocation movement in the course of atomic arrangement of the configuration change.We calculate the velocity and energy of right and left kink of 30 degrees dislocation using molecular dynamics method and NEB method. We achieve that the migration energy of LK is higher than RK and RK movement speed faster than LK. However, as the migration energy of both LK and RK are high, so their movements are very slow. When the pressure and temperature exceeds a certain value, RK and LK are decomposed, and that accelerate the movement of dislocations. In the LC and RC speed simulation, we found that the migration energy of RC is far lower than LC, and the velocity of RC is also much faster than LC. This also explains that the decomposition of RC and RD is expedite the movement speed, But the velocity of LK is accelerated by the appearance of the kink pair.