Evolution of low frequency noise and noise variability through CMOS bulk technology nodes

In this paper, we present a thorough investigation of low frequency noise (LFN) and statistical noise variability through CMOS bulk technologies manufactured in STMicroelectronics along the past 12 years. The experimental results are well interpreted by the carrier number (CNF) with correlated mobility (CMF) fluctuation model. This enabled us to plot the evolution with time and technology generation of the oxide trap density N
_t
, as a function of equivalent oxide thickness EOT. It appears that, with the device miniaturization, N
_t
, has increased from 2×10
¹⁶
/eV/cm
₃
up to 5-7×10
¹⁷
/eV/cm
₃
when passing from EOT=12nm for 250nm node to EOT=1.4nm for 28nm node for n-MOS. Despite this increase of the mean trap density N
_t
, the LFN statistical variability has surprisingly been well controlled and even improved in 28nm node, emphasizing the progress in process control in such advanced technologies.