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.