Electrical property of HfOxNy–HfO2–HfOxNy sandwich-stack films

Abstract The effects of HfO x N y on the electrical property of HfO x N y –HfO 2 –HfO x N y sandwich-stack (signed as SS) films were investigated. Excellent electrical performances were achieved in SS films, with a high dielectric constant of 16 and a low leakage current of ∼2 × 10 −8  A/cm 2 at 1 MV/cm. Schottky (SK) emission and Frenkel–Poole (PF) emission are found to be the dominant mechanisms for the current conduction behavior. After a long time stress, the flat-band voltage shift in the SS film is much smaller than that in a pure HfO x N y film indicating fewer charge traps existed in the SS film. Based on the experiments, the new SS structure is more favorable for the improvement of electrical performances than a pure HfO x N y or HfO 2 structure.