Hafnium carbamates and ureates: new class of precursors for low-temperature growth of HfO2 thin films

Novel volatile compounds of hafnium, namely tetrakis-N,O-dialkylcarbamato hafnium(IV) [Hf(iPrNC(O)OiPr)4] (1) and tetrakis-N,N,N’-trialkylureato hafnium(IV) [Hf(iPrNC(O)N- (Me)Et)4] (2), have been synthesized through the simple insertion reaction of isopropyl isocyanate into hafnium isopropoxide and hafnium ethylmethylamide, respectively; based on the promising thermal properties, compound 1 has been evaluated as a precursor for metalorganic chemical vapor deposition (MOCVD) of HfO2 thin films, which resulted in the growth of stoichiometric and crystalline layers with a uniform morphology at temperature as low as 250 °C.