Investigations into the structure, reactivity, and AACVD of aluminium and gallium amidoenoate complexes

Amidoenoate (AME = {ethyl-3-(R-amido)but-2-enoate}) complexes of aluminium and gallium, of the type: [AlCl2(AME(R))] R = iPr (1-Al); [AlCl(AME(R))(2)] R = iPr (2-Al), Dip (3-Al); [GaCl2(AME(R))] R = iPr (1-Ga) and [GaCl(AME(R))(2)] R = iPr (2-Ga), Dip (3-Ga), have been synthesised (iPr = isopropyl, Dip = 2,6-diisopropylphenyl). The coordination chemistry of these complexes has been studied in relation to precursor suitability. Investigations into the reactivity of the aluminium and gallium amidoenoate complexes involved reactions with hydride sources including alkali metal hydride salts, alkylsilanes, and magnesium hydride species and magnesium(I) dimers. The isolation of alkyl metal amidoenoate precursors including an aluminium hydride amidoenoate, [AlH(AME(Dip))(2)] (4-Al) and dimethyl gallium amidoenoates [GaMe2(AME(Dip))] (4-Ga), [GaMe2(AME(iPr))] (5-Ga) concluded the synthetic studies. A selection of the isolated complexes were used as precursors for aerosol assisted chemical vapour deposition (AACVD) at 500 degrees C. Thin films of either amorphous Al2O3 or Ga2O3 were deposited and subsequently annealed at 1000 degrees C to improve the materials' crystallinity. The films were characterised by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), UV-visible (UV-vis) spectroscopy and energy dispersive X-ray analysis (EDXA).

Automated summary

The study synthesized and investigated the coordination chemistry of amidoenoate complexes of aluminium and gallium, exploring their suitability as precursors and isolating various alkyl metal amidoenoate precursors. These complexes were used for aerosol assisted chemical vapour deposition (AACVD) to deposit thin films of either amorphous Al2O3 or Ga2O3, which were subsequently annealed at 1000 degrees C for improved crystallinity. The films were characterized by various analytical techniques.