Gallium Hydride Complexes Stabilised by Multidentate Alkoxide Ligands: Precursors to Thin Films of Ga2O3 at Low Temperatures

The donor-functionalised alkoxides {Me3-xN(CH2CH2O)x} (Lx; x=1, 2) have been used to form gallium hydride complexes [{GaH2(L1)}2] and [{GaH(L2)}2] that are stable and isolable at room temperature. Along with a heteroleptic gallium tris(alkoxide) complex [Ga(L1)3] and the dimeric complex [{GaMe(L2)}2], these compounds have been used as single-source precursors for the deposition of Ga2O3 by aerosol-assisted chemical vapour deposition (AACVD) with toluene as solvent. The resulting films were mostly transparent, indicating low levels of carbon contamination, and they were also mainly amorphous. However, [Ga(L1)3] did contain visibly crystalline material deposited at a substrate temperature of 450 degrees C, by far the lowest ever observed for the CVD of gallium oxide.