Abstract
Abstract In this thesis, the MOS-C devices with various high-k gate dielectrics and metal electrodes are characterized. It is found that high dielectric constants of Ta2O5 films in the stacked structures can be obtained. This may be due to no interfacial oxide layer formed or no inter-diffusion occurred with the buffer layers. Besides, the incorporation of nitrogen by the plasma N2O annealing may also increase the dielectric constants of Ta2O5 films. The single Ta2O5 film with TiN electrode is not as leaky as that with Al electrode. Accordingly, TiN is better than Al to be the electrode for Ta2O5. The result has demonstrated that the stacked structures successfully reduce the leakage current of Ta2O5 films by magnitude of several orders, especially for oxynitride than Si3N4 as the buffer layer. Plasma induced charging damage on high-k gate dielectrics has also been investigated. It is found that the gate leakage currents of antennas located on wafer center are apparently higher than those located on wafer edge. However, the antenna area effects are not as significant as the antenna periphery effects. In addition, damages induced by the plasma photoresist stripping process decrease as channel lengths shrink for oxynitride and Si3N4 gate dielectrics. Nevertheless, they increase as channel lengths shrink for various Ta2O5 gate dielectrics, which is unfavorable for various Ta2O5 gate dielectrics to scale down in the future.