Recent Advances in the Understanding of Random Telegraph Noise in 3-D NAND Flash memories

The transition from planar (2D) to three-dimensional (3D) arrays represented a turning point for the phenomenology of random telegraph noise (RTN) in NAND Flash technologies. The relevant changes in the cell structure and in the process integration at the basis of that transition, in fact, strongly impacted some major aspects of the physics responsible for RTN and for its dependence on the array working conditions. In this paper, we comprehensively discuss the recent advances in the exploration and in the understanding of such physics in 3D arrays. The discussion allows us to identify the most relevant details related to array operation, which must be addressed to mitigate the reliability issues arising from RTN, contributing to the attempt to prolong the successful evolutionary trends of 3D NAND Flash technologies.