Nitrous oxide gas phase chemistry during silicon oxynitride film growth

N₂O gas phase chemistry has been examined as it relates to the problem of ultrathin film silicon oxynitridation for semiconductor devices. Computational and analytical kinetics studies are presented that demonstrate: (i) there are 5 main reactions in the decomposition of N₂O, (ii) the gas composition over a 1000K - 1400K temperature range is as follows: N₂ (65.3 - 59.3%); O₂ (32.0 - 25.7%), NO (2.7 - 15.0%), (iii) the N₂O decomposition obeys first-order kinetics, and the initial rate law for N₂O decomposition is R_init = 2k₁[N₂O] which rapidly changes to R_late = k₁[N₂O] as the reaction proceeds, (iv) the branching ratio for the two reactions: N₂O + O → 2NO and N₂O → O N₂ + O₂ lies between 0.1 and 0.5 (0.1 < α < 0.5) and varies with conditions, (v) the apparent activation energy for the decomposition of N₂O is 2.5 eV/molecule (2.4×10² kJ/mole), (vi) the rate law for NO formation is R = k₁[N₂O], and (vii) the apparent activation energy for the formation of NO is 2.4 eV/molecule (2.3×10² kJ/mole).