“…It is rare to have a trap located just above this percolation path and such a trap will cause a large δVth and result in the long distribution tail [2], [6], [7], [24]. Modelling the long tail in the CDF is a tall order and three statistical distributions have been proposed: Exponential [3]- [6], [23], [25]- [29], Lognormal [1], [5]- [8], [30]- [32] and Gumbel [9]- [11]. The success of RTN modelling in term of yield prediction for a system, such as SRAM, requires an accurate statistical distribution tail [2], [5], [7], [30], [31].…”