Emerging Nanoelectronic Devices

5Phase Change Memory

Rakesh Jeyasingh, Ethan C. Ahn, S. Burc Eryilmaz, Scott Fong and H.-S. Philip Wong

Department of Electrical Engineering, Stanford University, USA

5.1 Introduction

In the late 1960s, Stanford Ovshinsky's (1922–2012) discovery of switching and phase change phenomena in chalcogenide materials [1] seeded new possibilities in data storage understanding/application. Initially, phase change chalcogenides impacted the optical disk market, enabling DVD and Blu-ray disks. Concomitantly, innovation in the materials and solid-state memory device research has led to Phase Change Memory (PCM) as one of the potential candidates for future nonvolatile memory technology [2]. The traditional memory hierarchy has a major bottleneck for improving the overall system performance due to increasing performance gap between the main memory and hard disk storage. PCM has the potential to combine DRAM-like features such as bit alteration, fast read and write, and good endurance and Flash-like features such as nonvolatility using a simple device structure. Thus introduction of PCM in the memory hierarchy would enable a seamless and versatile data exchange between the processor and storage [3]. PCM is also expected to be a highly scalable technology extending beyond the scaling limit of existing memory devices [4].

In this chapter, we focus on one of the mature emerging memory technologies – PCM – by summarizing the important material and device learning in recent years [5–8], with ...