Low leakage current transport and high breakdown strength of pulsed laser deposited HfO2/SiC metal-insulator-semiconductor device structures

Hafnium oxide (HfO2) thin films were deposited by the pulsed laser deposition (PLD) method on SiC substrates. The bandgap of HfO2 thin films was observed to be 5.8 eV. The chemical nature and stoichiometry of the films were analyzed by x-ray photoelectron spectroscopy (XPS). Metal-insulator-semiconductor (MIS) structures with Ni as a top electrode and TiN as a bottom electrode were fabricated to study the leakage current properties. The devices exhibited leakage current density of 50 nA/cm(2). The dielectric constant of these films is estimated to be in the range 17-24 from capacitance-voltage (C-V) measurements. The frequency dependence of the interface trapped charges is studied.