A. Bongiorno et A. Pasquarello, Validity of the bond-energy picture for the energetics at Si-SiO2 interfaces, PHYS REV B, 62(24), 2000, pp. R16326-R16329
Using a first-principles approach, we assess the validity of a picture for
the energetics at Si-SiO2 interfaces based on bond energies complemented wi
th penalty energies for silicon atoms in intermediate oxidation states. By
total-energy calculations on cluster models, we demonstrate that such penal
ty energies only depend on the composition of the first-neighbor shell of t
he silicon atoms and can thus be taken as additive contributions to the tot
al energy. Considering oxygen incorporation processes in Si-SiO2 interface
models, we show that variations in the interface energy result from suboxid
e and strain contributions of comparable magnitude. Hence, simplified schem
es for the energetics at Si-SiO2 interfaces should account for both contrib
utions with similar accuracy.