TY - JOUR
T1 - Diffusion-reaction mechanisms of nitriding species in SiO2
AU - Orellana, W.
AU - Da Silva, Antônio J.R.
AU - Fazzio, A.
N1 - Funding Information:
This work was supported by FAPESP and CNPq. We also would like to thank CENAPAD-SP for computer time.
PY - 2004/9
Y1 - 2004/9
N2 - We study using first-principles total-energy calculations, diffusion-reaction processes involved in the thermal nitridation of SiO 2. We consider NO, NH, N2, and atomic N in different charge states as the nitriding species in α-quartz. Our results show that none of neutral species react with the SiO2 network remaining at interstitial sites. Therefore, they are likely to diffuse through the oxide, incorporating nitrogen at near-interface (Si-SiO2) regions. Whereas, charged species are trapped by the network, nitriding bulk SiO2. For the diffusing species, we find that NH and atomic N show increasing diffusivities with temperatures, whereas for NO and N2 they are relatively constant. This result agrees well with the finding of higher N concentrations at the Si-SiO2 interface obtained by thermal processing of SiO2 in NH3 as compared with those obtained in N2O. Finally, we discuss spin-dependent incorporation reaction mechanisms of NH and atomic N with the SiO2 network.
AB - We study using first-principles total-energy calculations, diffusion-reaction processes involved in the thermal nitridation of SiO 2. We consider NO, NH, N2, and atomic N in different charge states as the nitriding species in α-quartz. Our results show that none of neutral species react with the SiO2 network remaining at interstitial sites. Therefore, they are likely to diffuse through the oxide, incorporating nitrogen at near-interface (Si-SiO2) regions. Whereas, charged species are trapped by the network, nitriding bulk SiO2. For the diffusing species, we find that NH and atomic N show increasing diffusivities with temperatures, whereas for NO and N2 they are relatively constant. This result agrees well with the finding of higher N concentrations at the Si-SiO2 interface obtained by thermal processing of SiO2 in NH3 as compared with those obtained in N2O. Finally, we discuss spin-dependent incorporation reaction mechanisms of NH and atomic N with the SiO2 network.
UR - http://www.scopus.com/inward/record.url?scp=19744381290&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.70.125206
DO - 10.1103/PhysRevB.70.125206
M3 - Article
AN - SCOPUS:19744381290
SN - 0163-1829
VL - 70
SP - 125206-1-125206-7
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 12
M1 - 125206
ER -