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 epsilon = 50-110 in films 35 nm thick. The high-specific-capacitance a-Ti1-yMyOx films thus produced are suitable for incorporation into future Si integrated circuit technology, e.g., for storage capacitors in semiconductor memory circuits. (C) 1999 American Institute of Physics. [S0003-6951(99)04120-0].