Applicability of the Carrier Number Fluctuations Model for Random Telegraph Noise of Nanoscale MOSFETs Operating in Saturation

Random Telegraph Noise (RTN) amplitudes are analyzed for different drain-source voltage biases in bulk MOSFETs issued from a CMOS 40 nm technology. The study highlights the modulation of RTN amplitudes due to the responsible trap’s position along the channel from source to drain. We show that the carrier number fluctuation (CNF) model can still be very accurate, even in saturation region, for traps located around the middle of the channel, but either underestimates or overestimates the resulting current shift, when applied to traps near the drain or source regions. The results emphasize the need to take into consideration the possible RTN amplitude modulation in saturation for realistic modeling.