Kinetic Modeling of Ammonia Decomposition at CVD Conditions

Kinetic modeling has been used to study the decomposition chemistry of ammonia at a wide range of temperatures, pressures, concentrations, and carrier gases mimicking the conditions in chemical vapor deposition (CVD) of metal nitrides. The modeling show that only a small fraction of the ammonia molecules will decompose at most conditions studied. This suggests that the high NH3 to metal ratios often employed in CVD is due to the very low amount of reactive decomposition products rather than due to rapid decomposition of ammonia into stable dinitrogen and dihydrogen as suggested by purely thermodynamic models.