Nanoscale CMOS Ring Oscillators for Statistical Characterization of Random Telegraph Noise

The Random Telegraph Noise (RTN) is one of the major reliability concerns in nanoscale CMOS technologies. In this paper, we discuss the characterization of RTN in 40 nm CMOS technology using Ring Oscillators (ROSCs). We used two different types of ROSCs to study the temporal and spectral characteristics of the RTN. With this work, we analyse the suitability of the two types of ROSC for on chip statistical analysis of the RTN amplitude strength and its frequency characteristics. Already the preliminary results, without complete statistical coverage show $\triangle$f/$f_{max}$ variations of up to 7.18% which maximize RTN observability. Further, the observed broad variations in normalized phase noise under varying power supply levels in the range of 0.5 V to 1 V indicate that also the bias dependence of RTN centers can be investigated using the ROSC technique.