Complex Random Telegraph Noise (RTN): What Do We Understand?

As the generally-accepted simple understanding, the random telegraph noise (RTN) induced by a single trap is explained by the “normal” two-state trap model, and the RTNs caused by two or more traps in one device are regarded as the independent superposition effect of these traps. While in real cases, both the above points cannot illustrate many complex RTN (cRTN) results in practice. In this paper, two categories of complex RTNs, which are induced by the metastable trap-states and the trap coupling effect, respectively, are investigated based on experimental results in detail. The RTN with metastable states are explained based on the observed “anomalous” RTN data. The physical mechanisms of the trap coupling effect on RTN amplitudes and time constants are studied based on experiments. The results are helpful for comprehensive understanding and modeling of RTN and switching traps, thus is useful for the accurate evaluation on the impacts of RTN on nanoscale CMOS devices and circuits.