Dielectric properties of Er-doped HfO_2 (Er～15%) grown by atomic layer deposition for high-κ gate stacks

摘要

Er-doped HfO_2 (Er～15%) films are grown by atomic layer deposition on Si(100). The characteristics of the doped oxide are compared with those of HfO_2. In Er-doped HfO_2, the stabilization of the cubic structure, together with the effect of the high polarizability of Er~(3+), allow to obtain a dielectric constant of ～33 after annealing at 900℃. The insertion of Er within the metallic sublattice of HfO_2 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 HfO_2 than for HfO_2.