Amorphous lanthanide-doped TiOx dielectric films

Abstract

Addition of Nd, Tb, or Dy to amorphous Ti–O thin films is found to improve the dielectric properties of the films. Specifically, substitution of 10–30 at. % of the dopant for Ti is found to dramatically decrease the leakage current, increase the breakdown voltage, and yet retain the relatively high dielectric constant $\text{ε=50–110}$ in films 35 nm thick. The high-specific-capacitance $\mathrm{a-}{\mathrm{Ti}}_{\text{1−y}}{\mathrm{M}}_y{\mathrm{O}}_x$ films thus produced are suitable for incorporation into future Si integrated circuit technology, e.g., for storage capacitors in semiconductor memory circuits.