Chemical vapor deposition and characterization of hafnium oxide films

HfO2 layers were grown on silicon by metalorganic chemical vapor deposition using (C5H5)(2)Hf(CH3)(2), (C5H5)(2)Hf(N(C2H5)(2))(2) and Hf(dpm)(4) as volatile precursors and were characterized by IR, XP, ED-spectroscopy, X-ray diffraction, ellipsometry and electrophysical methods. The films were shown to consist of monoclinic HfO2 and to contain hafnium silicide and silicate at the HfO2/Si interface. The presence of hafnium silicide was attributed to oxygen deficiency induced by argon ion sputtering of the film during XPS analysis. Hafnium silicate was formed as a result of the reaction between hafnia and silicon oxides during annealing. Current-voltage and capacitance-voltage measurements on Al/HfO2/Si test structures were used to determine the dielectric permittivity and electrical resistivity of the films: k = 15-20, rho = 1015 Omega cm. (C) 2007 Elsevier Ltd. All rights reserved.