Magnetoresistive random access memory using magnetic tunnel junctions

TLDR

MRAM merges spintronic devices with silicon microelectronics to deliver nonvolatility, unlimited read/write endurance, high speed, and competitive densities, with magnetic tunnel junctions offering large read signals and tunable resistance. The paper reviews recent progress in developing MTJ‑MRAM technology, describing its read, write, and CMOS‑integration operations that enabled a 1‑Mbit memory chip. The authors compare key memory attributes of MTJ‑MRAM to other memory technologies, detailing its operational characteristics and performance advantages.

Abstract

Magnetoresistive random access memory (MRAM) technology combines a spintronic device with standard silicon-based microelectronics to obtain a combination of attributes not found in any other memory technology. Key attributes of MRAM technology are nonvolatility and unlimited read and write endurance. Magnetic tunnel junction (MTJ) devices have several advantages over other magnetoresistive devices for use in MRAM cells, such as a large signal for the read operation and a resistance that can be tailored to the circuit. Due to these attributes, MTJ MRAM can operate at high speed and is expected to have competitive densities when commercialized. In this paper, we review our recent progress in the development of MTJ-MRAM technology. We describe how the memory operates, including significant aspects of reading, writing, and integration of the magnetic material with CMOS, which enabled our recent demonstration of a 1-Mbit memory chip. Important memory attributes are compared between MRAM and other memory technologies.