Comparative Simulation Study of the Different Sources of Statistical Variability in Contemporary Floating-Gate Nonvolatile Memory

Sensitivity-based investigation of threshold voltage variability in 32-nm flash memory cells and MOSFETs

“…This step is based on the assumption that the effect of each source is sufficiently small that first-order linearization is applicable. Also in the case of the 32 nm Flash memory [3], the variance of the threshold voltage due to combined effect computed with 3D atomistic statistical simulations is shown to be very close to the sum of the variances due to individual effects, giving us confidence in the linear approximation.…”

“…In recent years, simulation studies of variability have typically relied on 3D atomistic statistical simulations, such as [3]. However, here we show that a recently proposed method based on TCADenabled sensitivity analysis [4][5], allows us to accurately compute the standard deviation of electrical quantities -such as the threshold voltage -with a reduction in computational cost of more than two orders of magnitude.…”

“…In the framework of the ENIAC Joint Undertaking MODERN project [6], we have considered a template device structure for a 32 nm CMOS flash memory cell, for which variability assessments based on threedimensional atomistic statistical simulations and the impedance field method have been published [3]. We analyse the impact of variability sources such as random dopant distribution (RDD) [7], line-edge roughness (LER), line-width roughness (LWR), [8][9] interface trapped charge (ITC) [10], oxide thickness fluctuations (OTF) [11].…”

Sample-to-Sample Variability and Bit Errors Induced by Total Dose in Advanced NAND Flash Memories

“…Fig. 12 shows how intrinsic variability in FG for SLC NAND cells is expected to increase as the technology is scaled down [15]. If is the number of electrons stored in a programmed cell, the dispersion in the retention time is expected to increase with as the feature size decreases.…”

Evidence for an atomistic-doping induced variability of the band-to-band leakage current of nanoscale device junctions

“…In addition to extrinsic sources due to process tolerances, new intrinsic variability sources have become important factors with the scaling of device dimensions to the sub-100 nm regime, greatly affecting the reproducibility of many of the device's electrical characteristics [1]. Clear experimental evidence of a statistical variability even for the leakage current of p-n junctions in MOSFET [2] has been recently reported, despite the fact that its main physical origin has not been clearly highlighted.…”