Er−doped HfO2 (Er∼15%) films are grown by atomic layer deposition on Si(100). The characteristics of the doped oxide are compared with those of HfO2. In Er−doped HfO2, the stabilization of the cubic structure, together with the effect of the high polarizability of Er3+, allow to obtain a dielectric constant of ∼33 after annealing at 900 °C. The insertion of Er within the metallic sublattice of HfO2 reduces the net density of fixed charges, due to the creation of oxygen vacancies. For similar equivalent oxide thickness, lower leakage currents are measured for Er−doped HfO2 than for HfO2.
3 May 2010
Volume: 96 Issue: 18 Pages: 182901
Applied Physics Letters