Recent developments in magnetic tunnel junction MRAM

TLDR

Switching characteristics of MTJ‑based MRAM are mainly governed by magnetic shape anisotropy arising from element boundaries. We summarize our progress on MRAM based on magnetic tunnel junctions. The study examines MRAM devices constructed from magnetic tunnel junctions. We demonstrated MTJ material with MR values above 40 % over 1–1000 kΩ/μm², showed that switching repeatability and hard‑axis selectability depend on shape and aspect ratio, and integrated MTJ memory into 0.6 μm CMOS achieving 14 ns read/program access times in a 256‑bit MRAM.

Abstract

We summarize our progress on Magnetoresistive Random Access Memory (MRAM) based on Magnetic Tunnel Junctions (MTJ). We have demonstrated MTJ material in the 1-1000 k/spl Omega/-/spl mu/m/sup 2/ range with MR values above 40%. The switching characteristics are mainly governed by the magnetic shape anisotropy that arises from the element boundaries. The switching repeatability, as well as hard axis selectability, are shown to be dependent on both shape and aspect ratio. MTJ memory elements were successfully integrated with 0.6 /spl mu/m CMOS technology, achieving read and program address access times of 14 ns in a 256/spl times/2 MRAM.