Département de chimie moléculaire

AlN growth by HTCVD (high temp. CVD) from AlCl3 and NH3 is currently a promising way to obtain thick, compact layers of AlN. This study focused on the development of a kinetic mechanism that models AlN growth with only 7 gas-phase reactions and 4 surface reactions. Ab initio estn. of the thermodn. data of the AlCl2NH2, AlClNH, AlCl(NH2)2, and Al(NH2)3 intermediates suspected to be involved in the gas-phase reactions is proposed. Only AlCl2NH2 is present in noticeable concns. under our exptl. conditions. Expts. made at different temps. and N/Al ratios, carried out in a cold wall HTCVD reactor, were used to validate the proposed model. Finally, the N/Al ratio in the gas phase was obsd. to play a key role in the AlN surface quality. Possible explanations of this influence and future expts. that will confirm this trend are discussed. [on SciFinder(R)]