Structure, Energetics, and Thermal Stability of Nitrogen-Vacancy-Related Defects in Nitrogen Doped Silicon

Abstract

The electronic structure, formation energy, and thermal stability of nitrogen-vacancy related complexes in silicon have been investigated using density functional theory and semi-empirical Hartree-Fock calculations. The calculated energies of formation in the ground state showed that was not stable, whereas when formed from was the most stable, followed by and formed from a divacancy. The calculated free energy changes of the considered chemical reactions confirmed the low stability of compared to The latter can form during crystal growth from whereas reactions between and divacancy can also occur upon wafer heating. At low nitrogen concentration cm−3), only about 10% of vacancy concentration was converted into while at a high nitrogen concentration cm−3) about 75% of vacancies are trapped by nitrogen. appeared to create a potential well of −2.4 eV for oxygen and about −0.3 eV for vacancies, suggesting that the stable is a nucleus for oxygen precipitation while it is a weak trapping center for vacancies. © 2003 The Electrochemical Society. All rights reserved.