A 4-Mb toggle MRAM based on a novel bit and switching method

TLDR

A 4‑Mb MRAM with a novel magnetic bit cell and toggle switching mode is presented. The device was fabricated in a five‑level, 0.18‑µm CMOS process with a 1.55‑µm² bit cell that employs a balanced synthetic antiferromagnetic free layer and a phased write‑pulse sequence to achieve robust toggle switching. This switching mode greatly improves the operational performance of the MRAM compared to conventional MRAM.

Abstract

A 4-Mb magnetoresistive random access memory (MRAM) with a novel magnetic bit cell and toggle switching mode is presented. The circuit was designed in a five level metal, 0.18-/spl mu/m complementary metal-oxide-semiconductor process with a bit cell size of 1.55 /spl mu/m/sup 2/. The new bit cell uses a balanced synthetic antiferromagnetic free layer and a phased write pulse sequence to provide robust switching performance with immunity from half-select disturbs. This switching mode greatly improves the operational performance of the MRAM as compared to conventional MRAM. A detailed description of this 4-Mb toggle MRAM is presented.