Analysis of pulsed injection of precursors in AlN-MOVPE growth by computational fluid simulation

We report computational analysis of gas-phase states and main reaction pathways under AlN metalorganic vapor-phase epitaxy (MOVPE) by pulsed injection (PI) method of precursors. Interval times of 0–2 s were inserted between trimethylaluminum (Al(CH3); TMAl) and ammonia (NH3) supply phases to suppress parasitic reactions. In the cases of the interval time of 0 s, polymers and Al-N molecules were dominant species due to parasitic reaction, and the growth species was Al-N molecules generated by TMAl:NH3 pyrolysis. When an interval time was inserted between TMAl and NH3, mixing of TMAl and NH3 were suppressed. Al and NH2 generated from each precursor were dominant species. The main reaction pathway changed from TMAl:NH3 pyrolysis into TMAl pyrolysis with increasing the interval time. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)