Transparent polycrystalline monoclinic HfO ₂ dielectrics prepared by plasma assisted pulsed laser deposition

The electrical properties of transparent polycrystalline monoclinic HfO ₂ dielectrics prepared by plasma assisted pulsed laser deposition were studied. The capacitance-voltage and leakage current-voltage characteristics of the capacitors incorporating HfO ₂ dielectrics were examined in terms of the structural, optical properties of the HfO ₂ layers. The interfacial properties between the HfO ₂ layer and the Si substrate were also examined. The HfO ₂ layers showed excellent thermal stability both in the HfO ₂ structure and in the HfO ₂/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 HfO ₂ dielectrics had a dielectric constant of 16.5 and leakage current densities of 9.8 10 ^-8 and 9.2 10 ^-7 A/cm ² at dielectric fields of 0.75 and -0.75 MV/cm, respectively.