| Summary: | 碩士 === 國立虎尾科技大學 === 機械與機電工程研究所 === 98 === High-dielectric-constant (high-k) gate oxides with larger physical thickness while identical equivalent-oxide-thickness (EOT) have been widely used to supersede SiO2 for reducing gate leakage current in metal-oxide-semiconductor (MOS) devices. In this thesis, electrical and reliability characteristics of advanced MOS capacitors with various Ti- and Al-doped HfLaON dielectrics were demonstrated. Various Ti and TiAl concentrations in HfLaTiON and HfLaTiAlON dielectrics were achieved by co-sputter time of Ti, TiAl, and Hf2La2O7 targets. Modulated parameters include the co-sputter time of Ti, TiAl, and Hf2La2O7 targets, as well as post-deposition annealing (PDA). The compositions, crystalline properties, and energy band gap of HfLaTiON and HfLaTiAlON dielectrics were investigated by XPS, XRD, and UV/VIS/IR spectrophotometer, respectively. The results indicate that lower EOT of 0.17 nm and interface trap density (Dit) can be obtained by Ti-doped HfLaON dielectrics. The estimated Schottky barrier height during gate injection in Ta/HfLaTiON interface was around 0.8 eV. Also the results indicate that lower EOT of 0.093 nm and interface trap density (Dit) can be obtained by TiAl-doped HfLaON dielectrics. The estimated Schottky barrier height during gate injection in Ta/HfLaTiAlON interface was around 0.74 eV.
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