Transparent polycrystalline monoclinic HfO₂ dielectrics prepared by plasma assisted pulsed laser deposition

The electrical properties of transparent polycrystalline monoclinic HfO₂ dielectrics prepared by plasma assisted pulsed laser deposition were studied. The capacitance-voltage and leakage current-voltage characteristics of the capacitors incorporating HfO₂ dielectrics were examined in terms of the structural, optical properties of the HfO₂ layers. The interfacial properties between the HfO₂ layer and the Si substrate were also examined. The HfO₂ layers showed excellent thermal stability both in the HfO₂ structure and in the HfO₂/Si interface. The capacitance-voltage characteristics showed improvements through thermal annealing with a slight increase of leakage current. With an equivalent oxide thickness of 4.7 nm, the 700 °C annealed HfO₂ dielectrics had a dielectric constant of 16.5 and leakage current densities of 9.8 × 10⁻⁸ and 9.2 × 10⁻⁷ A/cm² at dielectric fields of +0.75 and −0.75 MV/cm, respectively.