Nitrous oxide gas phase chemistry during silicon oxynitride film growth

摘要

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. N-2 (65.3 - 59.3%), O-2 (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 = 2k(1)[N2O] which rapidly changes to R-late = k(1)[N2O] as the reaction proceeds, (iv) the branching ratio for the two reactions: N2O + O --> 2NO and N2O + O --> N-2 + O-2 lies between 0.1 and 0.5 (0.1 < a < 0.5) and varies with conditions, (v) the apparent activation energy for the decomposition of N2O is 2.5 eV/molecule (2.4x10(2) kJ/mole), (vi) the rate law for NO formation is R = k(1)[N2O], and (vii) the apparent activation energy for the formation of NO is 2.4 eV/molecule (2.3x10(2) kJ/mole). [References: 40]