Amorphous lanthanide-doped TiOx dielectric films

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.