Scaling limits of resistive memories

Abstract

This paper is intended to provide an expository, physics-based, framework for theestimation of the performance potential and physical scaling limits of resistive memory.The approach taken seeks to provide physical insights into those parameters and physicaleffects that define device performance and scaling properties. The mechanisms of resistiveswitching are based on atomic rearrangements in a material. The three model cases are: (1)formation of a continuous conductive path between two electrodes within an insulatingmatrix, (2) formation of a discontinuous path of conductive atoms between two electrodeswithin an insulating matrix and (3) rearrangement of charged defects/impurities near theinterface between the semiconductor matrix and an electrode, resulting in contactresistance changes. The authors argue that these three model mechanisms or theircombinations are representative of the operation of all known resistive memories.The central question addressed in this paper is: what is the smallest volume of matterneeded for resistive memory? The two related tasks explored in this paper are: (i)resistance changes due to addition or removal of a few atoms and (ii) stability of afew-atom system.