Metal-oxide-semiconductor (MOS) capacitors incorporating hafnium dioxide (HfO2) dielectrics were fabricated and investigated. In this work, the electrical and interfacial properties were characterized based on capacitance-voltage (C-V) and current - voltage (I-V) measurements. Thereafter the current conduction mechanism, electron effective mass (m*), mean density of interface traps per unit area and energy ((D) over bar (it)), energy distribution of interface traps density and near-interface oxide traps density (N-NIOT) were studied in details. The characterization reveals that the dominant conduction mechanism in the region of high temperature and high field is Schottky emission. The mean density of interface traps per unit area and energy is about 6.3 x 10(12) cm(2) eV(1) by using high-low frequency capacitance method. The maximum D-it is about 7.76 x 10(12) cm(2) eV(1) located at 0.27 eV above the valence band. (c) 2008 Elsevier B.V. All rights reserved.