Spectroscopic and structural studies on volatile gallium ?-diketonates as potential precursors for MOCVD

The complexes Ga(hfac)3 (Hhfac=hexafluoroacetylacetone) and Ga(dpm)3 (Hdpm=dipivaloylmethane) have been studied by solid and gas phase IR, mass spectrometry, 1H and 13C NMR, in order to prove their suitability as precursors for Ga2O3 deposition via metalorganic chemical vapor deposition (MOCVD). The crystal structure of Ga(hfac)3 was also determined. The complex crystallizes in the monoclinic space group P21/n with a=9.034(3), b=13.399(3), c=19.100(4) Å, ?=92.19(3)° for Z=4. The final R factor was 0.048. The Ga(III) ion exhibits a regular octahedral coordination with Ga?O bond distance of 1.954(5) Å (av. value). The X-ray, IR and MS studies showed the presence of identical monomeric species both in the solid and in the gas phase. Ga(hfac)3 was used in preliminary MOCVD experiments to grow Ga2O3 films.