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/cm². 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. [ABSTRACT FROM AUTHOR]