TiN - (Al,Hf)O2 - TiN capacitors Fariz Zharfan https://tugraz.webex.com/tugraz/j.php?MTID=m9c976de95c5becedaa40d56140173497 11:15 - 12:15 Wednesday 09 October 2024 In this thesis, the effect of different Al$_2$O$_3$ doping (Al-doping) concentrations into HfO$_x$ metal-insulator-metal (MIM) capacitor in terms of its performance and reliability has been characterized. Both capacitance and leakage performance were measured using capacitance-voltage and current-voltage measurements respectively. Both measurements showed an agreeing results with previous studies. Furthermore, Arrhenius behavior was also observed with the breakdown voltage(V$_b$$_d$) at all different Al-doped HfO$_x$. This observation is consistent with findings in other studies, which have thoroughly investigated the impact of Al-doping on capacitance and leakage performance. Therefore, a significant part of this thesis was to study the Al-doping impact on HfO$_x$ dielectric in terms of its reliability such as the lifetime and degradation behavior of the dielectric.
\\The time-dependent dielectric breakdown (TDDB) analysis was performed to investigate its reliability by applying constant voltage stress (CVS) at various voltages and temperatures. Al-doping concentrations of 10\%, 17\%, and 20\% were tested, with results showing that higher Al-doping concentrations increased the lifetime of MIM capacitors at all temperatures. The power law acceleration model was found to accurately describe and predict the lifetime of Al-doped HfO$_x$ MIM capacitors. Additionally, the time-to-failure (TTF) and the acceleration factor from the power law acceleration model for all three Al-doped HfO$_x$ exhibited Arrhenius behavior, with higher Al doping concentrations resulting in increased activation energy.
\\Furthermore, the current behavior over time during CVS measurements revealed distinct degradation patterns. The 10\% Al-doped HfO$_x$ showed progressive degradation, while the 17\% and 20\% concentrations tend to experience sudden hard breakdowns. These changes in degradation behavior could significantly affect the performance and long-term reliability of MIM capacitors. Overall, these findings emphasize the role of Al-doping in optimizing the reliability of HfO$_x$ MIM capacitors, providing valuable insights for the development of more durable microelectronic devices.
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