Ni doping significantly improves dielectric properties of La2O3 films

With rapid development of integrated circuits, a long-standing challenge is to seek new gate dielectrics to replace HfO2. Lanthanum oxide (La2O3) has earned more and more attention with its attractive performance. Rational doping is an extremely effective way to further improve its dielectric properties. In this work, Ni is first doped into La2O3 by reactive co-sputtering for a novel dielectric film. We demonstrate that proper amount of Ni (similar to 10.04%) doping can effectively improve the performance of La2O3, exhibiting desired microstructure, large band gap (5.7 eV), suitable band offsets (VB = 2.15 eV, CB = 2.43 eV) and excellent electrical properties (k = 22.08). Furthermore, we optimized the performance of Ni-doped La2O3 (LNO) films by altering annealing temperature. The results suggest that 600 degrees C is the most suitable annealing temperature for LNO films, leading to a lower leakage current density of 2.06 x 10(-4) A/cm(2). Our work provides a new insight to select the suitable element to modify rare earth oxides for next-generation gate dielectrics. (C) 2019 Elsevier B.V. All rights reserved.