Si Segregation into Pr2O3 and La2O3 high-k gate oxides

Pr and La oxide thin films were investigated in the context of their application as high-k dielectrics in complementary metal oxide technology. The films were deposited by molecular beam epitaxy on bare and TiN-covered Si(001). The influence of growth and post-deposition annealing on the composition and electrical parameters was studied. We observed Si penetration from bare Si(001) into the growing film. Based on the results of capacitance–voltage measurements and ab initio calculations, we conclude that Si is a source of defects responsible for leakage currents.