Emerging Nanoelectronic Devices

8Redox-based Resistive Memory

Stephan Menzel², Eike Linn¹, and Rainer Waser^1,2

¹Institute of Electronic Materials II, RWTH Aachen University, Germany

²Peter Grünberg Institut (PGI-7), Forschungszentrum Jülich, Germany

8.1 Introduction

Redox-based resistive memories (ReRAM) are a highly promising class of emerging memories [1]. ReRAM cells offer nonvolatile data storage in terms of at least two different resistances, a high resistive state (HRS) and a low resistive state (LRS). By applying appropriate voltage pulses one can switch between these resistance states. Intermediate states are feasible, too, enabling multilevel operation modes. ReRAM cells consist of a simple to fabricate Metal–Isolator–Metal (MIM) stack (see Figure 8.1), in which the insulator is an ion conductor at high fields and/or high temperature. These stacks enable 3D stackable crossbar array architectures. However, simple 1R array implementations suffer from the sneak path problem. Thus ReRAMs cells either require a two-terminal select device (1S1R or 1 CRS) in a passive crossbar architecture configuration, or a select transistor (1T1R) in an active memory matrix (Figure 8.1). The individual ReRAMs cells offer a high scaling potential below feature sizes of F < 10 nm, retention times >10 years, and excellent endurance properties (>10¹² cycles). In this chapter we will give an overview of the present knowledge of the physical switching mechanism, the modeling of ReRAMs and the state of the art of device performance. ...