Degradation of floating-gate memory reliability by few electron phenomena

The purpose of this paper is to give a quantitative evaluation of the intrinsic reliability limits of floating-gate (FG) memories in the decananometer range due to the reduction of collective phenomena and to the dominance of single-electron stochastic behaviors. To this end, first, a model that quantitatively predicts the intrinsic dispersions of the memory retention time and programming window is proposed. Second, experimental results obtained on ultrascaled memory devices (with an active area as small as 30 nm times 30 nm) with either a continuous poly-Si FG or silicon nanocrystals will be shown and used to validate this model. Finally, extrapolations on the intrinsic reliability limits of future generations of Flash memories will be done