Abstract: A magnetoresistive device is provided with separate read and write architecture. In one embodiment, a magnetic tunnel junction (MTJ) has a nonmagnetic nonconductive barrier layer sandwiched between two ferromagnetic conducting layers. A first read line is coupled to a first ferromagnetic layer and a second read line is coupled to a second ferromagnetic layer such that a voltage difference between the two read lines will produce a current flowing perpendicularly through each layer of the MTJ. A first write line is separated from the first read line by a first insulator and a second write line is separated from the second read line by a second insulator.

Abstract: A shielding arrangement for protecting a circuit containing magnetically sensitive materials from external stray magnetic fields. A shield of a material having a relatively high permeability is formed over the magnetically sensitive materials using thin film deposition techniques. Alternatively, a planar shield is affixed directly to a surface of semiconductor die containing an integrated circuit structure.

Abstract: In a process of making a magnetoresistive memory device, a mask layout is produced by use of any suitable design tool. The mask layout is laid out in grids having a central grid forming a central section and grids forming bit end sections, and the grids of the bit end sections are rectangles. A mask is made by use of the mask layout, and the mask has stepped bit ends. The mask is used to make a magnetic storage layer having tapered bit ends, to make a magnetic sense layer having tapered bit ends, and to make a non-magnetic layer having tapered bit ends. The non-magnetic layer is between the magnetic sense layer and the magnetic storage layer.

Abstract: In a method of fabricating a giant magnetoresistive (GMR) device a plurality of magnetoresistive device layers is deposited on a first silicon nitride layer formed on a silicon oxide layer. An etch stop is formed on the magnetoresistive device layers, and a second layer of silicon nitride is formed on the etch stop. The magnetoresistive device layers are patterned to define a plurality of magnetic bits having sidewalls. The second silicon nitride layer is patterned to define electrical contact portions on the etch stop in each magnetic bit. The sidewalls of the magnetic bits are covered with a photoresist layer. A reactive ion etch (RIE) process is used to etch into the first silicon nitride and silicon oxide layers to expose electrical contacts. The photoresist layer and silicon nitride layers protect the magnetoresistive layers from exposure to oxygen during the etching into the silicon oxide layer.

Abstract: A giant magnetoresistive memory device includes a magnetic sense layer, a magnetic storage layer, a non-magnetic spacer layer between the magnetic sense layer and the magnetic storage layer, and an antiferromagnetic layer formed in proximity to the magnetic storage layer. The antiferromagnetic layer couples magnetically in a controlled manner to the magnetic storage layer such that the magnetic storage layer has uniform and/or directional magnetization. Additionally or alternatively, an antiferromagnetic layer may be formed in proximity to the magnetic sense layer. The antiferromagnetic layer in proximity to the magnetic sense layer couples magnetically in a controlled manner to the magnetic sense layer such that the magnetic sense layer has uniform and/or directional magnetization.

Abstract: A bias-adjusted giant magnetoresistive (GMR) device includes a ferromagnetic reference layer, which has a magnetization that remains relatively fixed when a range of magnetic fields is applied, and a ferromagnetic switching layer, which has a magnetization that can be changed by applying a relatively small magnetic field. In MRAM applications, the switching layer stores data in the form of the particular orientation of its magnetization relative to the magnetization of the reference layer. At least one of the reference and switching layers is split into at least two ferromagnetic layers separated by one or more layers of a nonmagnetic conductor, such that the hysteresis curve of resistance versus applied magnetic field is substantially symmetric about zero applied magnetic field.