Synthesis, Characterization, and Mass Transport Properties of a Self-Generating Single-Source Magnesium Precursor for MOCVD of MgF2 Films

The diglyme [CH3O(CH2CH2O)2CH3] adduct of the magnesium bis-hexafluoroacetyl-acetonato [Mg(hfa)2 •2H2O• 2diglyme] has been synthesized in a single-step reaction. It has been characterized by elemental analyses, IR spectroscopy, and 1H and 13C NMR. Single-crystal X-ray diffraction studies provide evidence of a mononuclear hexa-coordinated complex with an octahedral structure for the Mg(hfa)2 2H2O moiety and diglyme coordinated in the outer sphere (triclinic system, space group = P-1; a = 8.952(3) Å, b = 9.036(3) Å, c = 11.98(1) Å, alpha = 110.44(5)°, beta = 108.64(4)°, gamma = 97.06(3)°, Z = 1). The “thermal robustness” and mass transport properties of the adduct have been investigated by thermogravimetric analysis and chemical vapor deposition experiments. Thermal analysis data revealed high volatility and good thermal stability with a residue left lower than 1%. The Mg(hfa)2•2H2O•2diglyme has been successfully applied to the low-pressure metal-organic chemical vapor deposition (MOCVD) of MgF2 films. The good quality of the deposited films indicates that the adduct is a very attractive single-source precursor for deposition of MgF2 films.