On the origin of nitrogen-induced retardation of boron diffusion in amorphous silica

The effect of N incorporation on B diffusion in amorphous Si O2 is presented based on spin-polarized density functional theory calculations. Our results show that N incorporation leads to the decrease of O vacancy concentration, which is largely responsible for the retarded B diffusion by reducing diffusion mediators such as E′ and S centers. We also determine the ground state structure of the BN complex, along with possible formation routes. The direct BN bonding interaction appears to only slightly increase the activation energy of B diffusion.