Liliana Mîinea, Seigi Suh, Simon G. Bott, Jia-Rui Liu, Wei-Kan Chu and David M. Hoffman
Aluminium and gallium fluoroalkoxide complexes of formula M(ORf)3(HNMe2) [M=Al or Ga; Rf=CH(CF3)2, CMe2(CF3) or CMe(CF3)2] were prepared by reacting the corresponding metal dimethylamide complexes with fluorinated alcohols. The dimethylamine adducts reacted with 4-dimethylaminopyridine to give M(ORf)3(4-Me2Npy) [M=Al or Ga; Rf=CH(CF3)2, CMe2(CF3) or CMe(CF3)2]. Crystal structure analyses of Ga[OCH(CF3)2]3(4-Me2Npy), Ga[OCMe2(CF3)]3(4-Me2Npy) and Al[OCMe(CF3)2]3(4-Me2Npy) showed they have distorted tetrahedral geometries. Gallium oxide films were prepared from Ga[OCH(CF3)2]3(HNMe2) and air by low-pressure chemical vapor deposition at substrate temperatures of 250-450°C. Films deposited at 450
°C had a composition of Ga2O3.1 by backscattering analysis, an optical band gap of 4.9 eV, and were >90% transmittant in the 300-820 nm region.