Varying internal parameters in the thermal silicon oxidation

Key parameters of the Arrhenius relation governing the oxide growth during the thermal oxidation of silicon have been found to depend on oxide thickness. The activation energy (Ea) has been found to decrease from 2.22 to 1.87 eV with increasing oxide thickness from 6.5 to 13 nm, whereas the reference formation rate R0 of silicon oxide decreases from 24.5 to 20.6 pm/s in the same thickness interval. The combination of these findings gives a linear course of the logarithm of reference rate vs. activation energy. In other words, the reference rate of oxide formation obeys an exponential dependence on activation energy. Calculations give the relation R0 [pm/s] = 0.916 exp. (11.05 Ea), with Ea in eV. The results have been obtained by a four-step-program.