Emerging Nanoelectronic Devices

4Spin Transfer Torque Random Access Memory

Jian-Ping Wang¹, Mahdi Jamali¹, Angeline Klemm¹, and Hao Meng²

¹University of Minnesota, USA

²Data Storage Institute, Singapore

4.1 Chapter Overview

Over the past years, there has been a significant effort in developing the next generation of nonvolatile memory (NVM) which would be used to replace or be integrated with current technologies. Semiconductor-based memory technologies such as SRAM and Flash are predicted to soon reach their fundamental limits in term of scaling [1]; therefore, an alternative technology capable of high areal density and low-power operation which can be embedded for memory applications is highly desirable. One potential NVM, Spin Transfer Torque Magnetic Random Access Memory (STT-RAM), emerged more than one decade ago and demonstrates the potential to replace most of today's semiconductor memory technologies [2]. It provides faster and more cost-effective solutions for future applications. In this chapter, STT-RAM technology development is reviewed.

Table 4.1 summarizes characteristics of different memory technologies [1]. It compares current state of the art technologies including DRAM, SRAM, and Flash memories, as well as other prototype technologies including STT-RAM, FeRAM, and PCM. STT-RAM utilizes magnetic materials for data storage, is a nonvolatile memory, and unlike DRAM, does not require periodic refreshing of stored information. This also enables instant-on capabilities. The endurance of Flash ...