Browsing by Author "Oates, Anthony S."

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An innovative understanding of metal-insulator-metal (MIM)-capacitor degradation under constant-current stress
(2007-09-01)
Hung, Chi-Chao
;
Oates, Anthony S.
;
Lin, Horng-Chih
;
Chang, Yu-En Percy
;
Wang, Jia-Lian
This paper provides a new understanding of metal-insulator-metal-capacitor-degradation behavior under a wide range of constant-current-stress conditions. It was found that capacitance degrades with stress, but the behavior of the degradation strongly depends on the stress-current density. At high stress levels, the capacitance increases logarithmically as the injection charge increases until dielectric breakdown occurs. At lower stress conditions, the degradation rate is proportional to the stress current and reverses after a certain period of time. A metal-insulator interlayer is observed using cross-sectional transmission-electron-microscopy micrographs, which possibly explains this reversal phenomenon.
Geometric Variability of Nanoscale Interconnects and Its Impact on the Time-Dependent Breakdown of Cu/Low-k Dielectrics
(2010-09-01)
Lee, Shou-Chung
;
Oates, Anthony S.
;
Chang, Kow-Ming
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Line edge roughness (LER) and via-line misalignment strongly impact the time-dependent breakdown of the low-k dielectrics used in nanometer IC technologies. In this paper, we investigate, theoretically and experimentally, the impact of the variability of geometry on breakdown. By considering the statistical distribution of thickness between adjacent conductors exhibiting LER, we show that the breakdown location is a function of voltage and occurs at the minimum dielectric thickness at high voltage, but moves to the median thickness at the low voltages. Using these concepts, we show that LER modifies the functional form of failure distributions, and leads to a systematic change in the Weibull beta with voltage. Accurate reliability analysis requires new reliability extrapolation methodologies to account for these effects. We show that the minimum dielectric thickness present on a test structure or on a circuit is readily determined from routine measurements of dielectric thickness between metal lines. We verify theoretical predictions using measurements of failure distributions of both via and line test structures. Finally, we have shown that LER can significantly modify the apparent field dependence of the failure time, leading to ambiguity in the interpretation of the experimentally determined field dependence.
New understanding of metal-insulator-metal (MIM) capacitor degradation behavior
(2007)
Hung, Chi-Chao
;
Oates, Anthony S.
;
Lin, H. C.
;
Chang, Percy
;
Wang, J. L.
This work provides an innovative understanding of MIM capacitor degradation behavior under a wide range of constant current stress (CCS) conditions. It was found that capacitance degrades with stress, but the behavior of the degradation strongly depends on the stress current density. At high stress levels, the capacitance increases logarithmically as the injection charge increases until dielectric breakdown occurs. At lower stress conditions, the degradation rate is proportional to the stress current, and reverses after a certain period of time. A metal-insulator interlayer is observed to explain this reversal phenomenon.