New Insights into the Amplitude of Random Telegraph Noise in Nanoscale MOS Devices

Amplitude distribution of random telegraph noise (RTN) in nanoscale CMOS technology is an open question, with both lognormal and exponential distributions widely reported in literatures. In this paper, we experimentally clarified the underlying reasons for the first time, and revealed that the trap coupling effect is the missing role behind the divergent measured results of RTN amplitude statistics. Based on the proposed new method, “clean” RTN data with and without coupling are successfully characterized. It is found that, with increasing of the coupling strength, the apparent distribution changes from exponential-like to lognormal-like; while the exact form is actually the two-stage lognormal distribution, originating from two categories of traps (located above the channel percolation paths or not). The results are essential for understanding of oxide trap coupling and modeling of RTN and are thus helpful for resilient circuit design against RTN in the future.