First-principles study of the segregation of boron dopants near the interface between crystalline Si and amorphous SiO2

Abstract

We investigate the stability of boron dopants near the interface between crystalline Si and amorphous SiO2 through first-principles density functional calculations. An interstitial B is found to be more stable in amorphous SiO2 than in Si, so that B dopants tend to segregate to the interface. When defects exist in amorphous SiO2, the stability of B is greatly enhanced, especially around Si floating bond defects, while it is not significantly affected near Si–Si dimers, which are formed by O-vacancy defects.