Influence of Rapid Thermal Annealing on the Structure and Electrical Properties of Ce-Doped HfO2 Gate Dielectric

Ce-doped HfO2 (HfCeO) films are prepared by radio-frequency magnetron sputtering. The influences of rapid thermal annealing on the structure and electrical properties of HfCeO films are investigated. The results show that the incorporation of Ce into HfO2 increases the crystallization temperature of HfO2, and the cubic phase of HfO2 can be stabilized by incorporating Ce into HfO2. After high temperature annealing, Hf 4f core level spectra shift to a higher energy, whereas O 1s core level spectra shift to a lower energy. With increasing annealing temperatures, the effective permittivity increases, whereas the flat-band voltage shift and effective oxide charge density decrease. Moreover, the leakage current density of the HfCeO films decreases initially, and then increases as the annealing temperature increases.