Abstract
In this thesis, Metal-Insulator-Si (MIS) capacitors with CeO2, Sm2O3 and HfO2 gate dielectrics were fabricated and investigated. The CeO2, Sm2O3 and HfO2 gate dielectrics were deposited by RF magnetron sputtering and atomic layer chemical vapor deposition (ALD), respectively. The XRD analysis revealed that CeO2 thin films already were polycrystalline at as-deposited, TEM analysis revealed that an interface layer (IL) was formed between the high-κ film (CeO2) and Si substrate. The dominant conduction mechanism of Al/CeO2/p-Si structure at high temperature (>350K) is Schottky emission in low electric fields (0.36~1.56 MV/cm) and at high temperature (500K) is Poole-Frenkel emission in high electric fields (1.69~2.66 MV/cm). The dominant mechanism of Al/Sm2O3/p-Si structure at high electric fields (1.96~4 MV/cm) is Schottky emission. The dominant mechanism of Al/HfO2/p-Si structure at low electric fields (0.16~2.89 MV/cm) is Schottky emission. Experimental results showed that the barrier height of Al/CeO2 is 0.478 eV at 1.53 MV/cm, and that of Al/Sm2O3 is 0.362 eV at 3.1 MV/cm and that of Al/HfO2 is 0.278 eV at 1.6 MV/cm. The extracted Weibull slope for different temperatures (25℃, 85℃, 125℃) is found to be 6.5 in CeO2 thin film, 7.1 in Sm2O3 thin film and 3.3 in HfO2 thin film. The activation energy of CeO2 thin film calculated from the QBD63% plots was about 0.37 eV, and it was about 0.346 eV for Sm2O3 thin film, and 0.143 eV for HfO2 thin film.