Influence of the ab-initio calculation parameters on prediction of energy of point defects in silicon

Point defects play a key role in many microelectronics technologies. Knowledge of the properties of point defects and characteristics of their behavior during ion-beam synthesis of microstructures for use in silicon devices allows one to optimize the conditions of their production, improve their quality and the electronic properties. In this situation, of valuable help in studying the properties of point defects is numerical modeling, especially with the use of quantum mechanical methods based on density functional theory approach. The paper describes a systematic study of the effect of various quantum–mechanical simulation approximations on the calculated energy parameters of defects as applied to simple point defects in silicon. We demonstrate that the choice of the form of the exchange–correlation functional has the strongest effect on the predicted defect formation energy, whereas the variation of the other considered approximations is of secondary importance for simulation predictions.