A single-electron analysis of NAND flash memory programming

Abstract

We present the first single-electron analysis of the program operation of NAND Flash arrays. The analysis leads, first of all, to a direct extraction not only of the average value but also of the statistical spread of the control-gate to floating-gate cell capacitance (Cpp). This allows, then, to assess the impact of Cpp variability, electron injection statistics and read noise on the distribution of the threshold-voltage shift coming from a programming pulse applied to the array cells. Finally, the electron leakage through the inter-gate dielectric along program is easily and directly quantified under real operating conditions.