Dielectric Properties and Flat-Band Voltages on Doped-HfO_2 Thin Films

摘要

The control of high-symmetry phases of HfO_2 can be achieved by cationic substitution for Hf. The electrical properties of HfO_2 cubic phase stabilized by addition of yttrium or magnesium are investigated. The introduction of moderate Y or Mg doping content (~10-15 at.%) in HfO_2 results in an enhancement of the dielectric constant. No degradation of the interface state density and leakage current is noticed. The flat-band voltage is shifted to positive voltages, similarly as it was observed for monoclinic and cubic pure HfO_2 thin films. This result confirms that the contribution of the SiO_2/high-K interface to the flat-band voltage depends on the structural high-K properties.