Chemical vapour deposition of polycrystalline AlN films from AlCl3–NH3 mixtures.

Structure, optical spectra and biaxial stress of (0002) AlN epilayers grown on c‐sapphire by high‐temperature chemical vapor deposition

“…2d, the growth rate was 2 mm h À1 at 1100 8C, while it sharply reached 7.8 mm h À1 at 1200 8C and slowly rose to 10.6 mm h À1 at 1400 8C with a slight drop at 1500 8C. The slight change of growth rate from 1200 to 1500 8C was in accordance with a diffusion-limited reaction mechanism [27,28]. Therefore, the sharp decrease of growth rate at 1100 8C indicated that the reaction was governed by a surface-reaction-limited mechanism.…”

Theoretical determination of the favorable mechanism of the reaction between AlX and HX (X = Br, Cl, and F)

“…Figs. [5][6][7] show that the concerted mechanism occurs also in three stepwises: the first one corresponds to the formation of the intermediates HX-AlX-XH by a complexation reactions between the reactant AlX Theoretical determination of the favorable mechanism of the reaction between AlX and HX (X = Br, Cl, and F) and two HX molecules, with a release energy of 9.87, 12.31, and 47.19 kJ mol -1 when X = Br, Cl, and F respectively. The second step is an isomerisation of the intermediates HX-AlX-XH to AlX 3 -H 2 complexes through the TS3(X) transition states with a high activation barrier energies of 185.46 kJ mol -1 for X = Br, 218.67 kJ mol -1 for X = Cl, 198.78 kJ mol -1 for X = F. The unique imaginary frequency of transition states TS3(Br), TS3(Cl), and TS3(F) are 1482.3i, 1495.6i, and 1490.2i, respectively.…”

“…Among these important compounds, a considerable importance has been given to the chemistry of the donor-acceptor alane complexes because of their importance in chemical catalysis and elementary chemistry and also because of their structural richness and their potential to act as metal sources in chemical vapor deposition (CVD) processes [5][6][7][8]. Thus, the knowledge of their complexation energies and their stability would be very useful for a quantitative description of their reactivity, reaction mechanisms and also their applications.…”

Growth of thick-film AlN substrates by halide vapor transport epitaxy

“…The conventional approach to the growth of AlN by the HVPE process [5,6] is to separate the AlCl 3 and NH 3 flows until they reach the hot substrate to prevent adduct formation in advance of the substrate. In fact, the AlCl 3 and NH 3 molecules can form a monoamine adduct even at room temperature that dissociates at about 700 C. The AlCl 3 and NH 3 molecules can also form a long line of other adducts with structures from dimers to hexagons with increasing stability [7].…”