Compositional, structural and electronic characteristics of HfO2 and HfSiO dielectrics prepared by radio frequency magnetron sputtering

HfO2 and HfSiO films were prepared on Si substrates by using radio frequency magnetron sputtering (RFMS). Compositional, structural and electronic properties of the two films were investigated completely. X-ray photoelectron spectroscopy (XPS) spectra showed that the atom ratio of Hf to O was about 1:2 in the HfO2 film and the chemical composition of the HfSiO film was Hf37Si7O56. Grazing incidence X-ray diffraction (GI-XRD) patterns indicated crystallization in the HfO2 film after 400 °C annealing, but there is no detectable crystallization in the HfSiO film after 800 °C annealing. C–V measurements indicated that the dielectric constants for the HfO2 and HfSiO film were 20.3 and 17.3, respectively. The fixed charge densities were found to be 6.0 × 1012 cm−2 for the HfO2 film and 3.7 × 1012 cm−2 for the HfSiO film. I–V characteristics showed that the average leakage current densities were 2.4 μA/cm2 for the HfO2 film and 0.2 μA/cm2 for the HfSiO film at the gate bias of 1 V.