Investigation of NBTI Dynamic Behavior with Ultra-Fast Measurement

Negative Bias Temperature Instability is a major concern for CMOS reliability. Characterization and modeling of degradation induced by NBTI is hard task because it depends on many parameters like temperature, voltage, stress time as well as defaults defects creation and recovery process. In this paper a dedicated test structure is developed to characterize Vth at constant current during high frequency stress. The circuit enables to switch between NBTI stress and Vth measurement, for which the first acquisition can be performed in several mu s. The degradation behavior is investigated from DC condition toward 1 GHz range with alternative DC-AC stimuli through intensive NBTI characterization. Finally, the observed behavior and the underlying physics are discussed