The science and technology of magnetoresistive tunneling memory

Rapid advances in portable communication and computing systems are creating an increasing demand for nonvolatile random access memory that is both high-density and highspeed. Existing solid-state technologies are unable to provide all of the needed attributes in a single memory solution. Therefore, a number of different memories are currently being used to achieve the multiple functionality requirements, often compromising performance and adding cost to the system. A new technology, magnetoresistive random access memory (MRAM) based on magnetoresistive tunneling, has the potential to replace these memories in various systems with a single, universal solution. The key attributes of MRAM are nonvolatility, high-speed operation. and unlimited read and write endurance. This technology is enabled by the ability to deposit high-quality, nanometer scale tunneling barriers that display enhanced magnetoresistive response. In this article we describe several fundamental technical and scientific aspects of MRAM with emphasis on recent accomplishments that enabled our successful demonstration of a 256-Kb memory chip