High write selectivity and low power magnetic random access memory and method for fabricating the same

Abstract

A low-power magnetic random access memory (MRAM) with high write selectivity is provided. Write word lines and pillar write word lines covered with a magnetic material are disposed in an zigzag relation, solving the magnetic interference problem generated by cells adjacent to the pillar write word line in the magnetic RAM with the pillar write word line form. According to the disclosed structure, each of the cells has a smaller bit size and a lower write current. This effectively reduces the power consumption of the MRAM.

Description

[0001] This application is a Divisional of co-pending application Ser. No. 10 / 846,663 filed on May 14, 2004, and for which priority is claimed under 35 U.S.C. §120; and this application claims priority of Application No. 92136353 filed in Taiwan on Dec. 19, 2003 under 35 U.S.C. §119; the entire contents of all are hereby incorporated by reference.BACKGROUND OF THE INVENTION [0002] 1. Field of Invention [0003] The invention relates to a magnetic random access memory (MRAM) and, in particular, to an MRAM with high write selectivity and low power consumption. [0004] 2. Related Art [0005] Magnetic random access memory (MRAM) is nonvolatile memory. Using its magnetic resistance property to record information, it has the advantages of non-volatility, high densities, high access speeds, and anti-radiation. [0006] The basic operation principles of the MRAM are the same as storing data on a hard disk drive (HDD). Each bit of data is determined by its magnetization orientation to be either 0 ...

AI Technical Summary

Benefits of technology

"The invention is a magnetic random access memory (MRAM) with high write selectivity and low power consumption. It reduces the write current required by the MRAM, thereby reducing the power consumption during the write period. The invention also eliminates the magnetic interference problem of the write word lines on adjacent MTJ's, increasing the write selectivity of the MRAM. The disclosed structure includes a plurality of MTJ cells, bit lines, middle metal pillars, and PWWL's. The PWWL's provide the write current channel for the MTJ cell and are disposed in an interleaving fashion to reduce the write current required by the MRAM. The invention also adds a photo mask process after the PWWL process and uses a sidewall keeper to reduce the write current required by the MRAM and to confine the magnetic flux on the MTJ so that adjacent MTJ's are not affected by the magnetic field produced by the PWWL's."

Problems solved by technology

As memory devices are becoming smaller, the MRAM starts to encounter the electron migration problem because the write-in electrical current needed to change data approaches the current density limit that can be carried by a metal wire.

Nonetheless, this structure has a problem.

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