| Summary: | 碩士 === 國立交通大學 === 電子研究所 === 99 === Amorphous silicon dioxide gate dielectric proffered many advantages in fabrication of MOSFET device,such as thermodynamically stable,high-quality Si/SiO2 interface and excellent electrical isolation properties.Therefore silicon dioxide has been applied popularly in the integrated circuit process technology in the past 40 years.In order to promote the performance of MOSFET device,ultrathin gate dielectric was needed.Oxide thickness would be less than 1.0 nm for 65 nm technology node,leading to high gate direct tunneling leakage current.Therefore,the scaling down of gate dielectric could not go on forever.High-κ gate dielectric could effectively reduced leakage current and maintained good device performance.Among many dielectric materials,HfO2 is the most promising material due to its high dielectric constant,relatively large band gap,and good thermal stability with Si.In this thesis, Al/Ti/HfO2/Si metal-insulator-semiconductor capacitors were used as control samples.The process which combined pre-deposition plasma fluorination and post-deposition plasma nitridation, we called it dual plasma treatment.This thesis reported current conduction mechanisms and reliability properties of HfO2 MIS capacitors with dual plasma treatment.It indicated that all samples with dual plasma treatment showed the promotion of capacitance density and reduction of leakage current.Dual plasma treatment could also greatly reduce the number of interface states and suppress the growth of interfacial layer.The current conduction mechanisms could be attributed to Schottky emission(SE),the Frenkel-Poole (FP)emission,and Fowler-Nordheim(FN) tunneling in different ranges of electric field.Schottky emission(SE) dominated in low to medium electric field(1.7-3.0MV/cm) and at high temperature(>348K),Frenkel-Poole(FP) emission dominated in medium to high electric field(4.0-6.0MV/cm) and Fowler-Nordheim(FN) tunneling dominated in electric field(>7MV/cm).
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