Abstract: A method and system for providing a magnetic element that can be used in a magnetic memory is disclosed. The magnetic element includes pinned, nonmagnetic spacer, and free layers. The spacer layer resides between the pinned and free layers. The free layer can be switched using spin transfer when a write current is passed through the magnetic element. The magnetic element may also include a barrier layer, a second pinned layer. Alternatively, second pinned and second spacer layers and a second free layer magnetostatically coupled to the free layer are included. At least one free layer has a high perpendicular anisotropy. The high perpendicular anisotropy has a perpendicular anisotropy energy that is at least twenty and less than one hundred percent of the out-of-plane demagnetization energy.
Abstract: A tunnel barrier in proximity with a layer of a rare earth element-transition metal (RE-TM) alloy forms a device that passes negatively spin-polarized current. The rare earth element includes at least one element selected from the group consisting of Gd, Tb, Dy, Ho, Er, Tm, and Yb. The RE and TM have respective sub-network moments such that the absolute magnitude of the RE sub-network moment is greater than the absolute magnitude of the TM sub-network moment. An additional layer of magnetic material may be used in combination with the tunnel barrier and the RE-TM alloy layer to form a magnetic tunnel junction. Still other layers of tunnel barrier and magnetic material may be used in combination with the foregoing to form a flux-closed double tunnel junction device.
Type:
Grant
Filed:
April 23, 2007
Date of Patent:
May 12, 2009
Assignee:
International Business Machines Corporation
Inventors:
Christian Kaiser, Stuart Stephen Papworth Parkin
Abstract: An MTJ in an MRAM array or in a TMR read head is comprised of a capping layer with a lower inter-diffusion barrier layer, an intermediate oxygen gettering layer, and an upper metal layer that contacts a top conductor. The composite capping layer is especially useful with a moderate spin polarization free layer such as a NiFe layer with a Fe content of about 17.5 to 20 atomic %. The capping layer preferably has a Ru/Ta/Ru configuration in which the lower Ru layer is about 10 to 30 Angstroms thick and the Ta layer is about 30 Angstroms thick. As a result, a high dR/R of about 40% is achieved with low magnetostriction less than about 1.0 E?6 in an MTJ in an MRAM array. Best results are obtained with an AlOx tunnel barrier layer formed by an in-situ ROX process on an 8 to 10 Angstrom thick Al layer.
Type:
Grant
Filed:
June 15, 2004
Date of Patent:
November 11, 2008
Assignees:
Headway Technologies, Inc., Applied Spintronics, Inc.
Inventors:
Cheng T. Horng, Ru-Ying Tong, Liubo Hong, Min Li
Abstract: One embodiment of the present invention includes a an embodiment of the present invention includes a non-volatile current-switching magnetic memory element including a bottom electrode; a pinning layer formed on top of the bottom electrode; a fixed layer formed on top of the pinning layer; a tunnel layer formed on top of the pinning layer; a first free layer formed on top of the tunnel layer; a granular film layer formed on top of the free layer; a second free layer formed on top of the granular film layer; a cap layer formed on top of the second layer; and a top electrode formed on top of the cap layer.
Abstract: A method of producing a device with a ferroelectric crystal thin film on a first substrate including the steps of providing a ferroelectric crystal, of irradiating a first surface of the ferroelectric crystal with ions so that a damaged layer is created underneath the first surface, of bonding a block of material including the first substrate to the ferroelectric crystal to create a bonded element, wherein an interface is formed between the first surface and a second surface of the block, and of heating the bonded element and separating it at the damaged layer, so that a ferroelectric crystal layer remains supported by the first substrate. By this method, very thin films—down to thicknesses of a fraction of a micrometer—of ferroelectric crystals may be fabricated without jeopardizing the monocrystalline structure.
Abstract: The invention includes a method of forming a semiconductor construction, such as an MRAM construction. A block is formed over a semiconductor substrate. First and second layers are formed over the block, and over a region of the substrate proximate the block. The first and second layers are removed from over the block while leaving portions of the first and second layers over the region proximate the block. At least some of the first layer is removed from under the second layer to form a channel over the region proximate the block. A material, such as a soft magnetic material, is provided within the channel. The invention also includes semiconductor constructions.
Abstract: Magnetic materials and uses thereof are provided. In one aspect, a magnetic film is provided. The magnetic film comprises superparamagnetic particles on at least one surface thereof. The magnetic film may be patterned and may comprise a ferromagnetic material. The superparamagnetic particles may be coated with a non-magnetic polymer and/or embedded in a non-magnetic host material. The magnetic film may have increased damping and/or decreased coercivity.
Type:
Application
Filed:
April 20, 2007
Publication date:
September 27, 2007
Applicant:
International Business Machines Corporation
Inventors:
Snorri Ingvarsson, Philip Trouilloud, Shouheng Sun, Roger Koch, David Abraham
Abstract: A tunnel barrier in proximity with a layer of a rare earth element-transition metal (RE—TM) alloy forms a device that passes negatively spin-polarized current. The rare earth element includes at least one element selected from the group consisting of Gd, Tb, Dy, Ho, Er, Tm, and Yb. The RE and TM have respective sub-network moments such that the absolute magnitude of the RE sub-network moment is greater than the absolute magnitude of the TM sub-network moment. An additional layer of magnetic material may be used in combination with the tunnel barrier and the RE—TM alloy layer to form a magnetic tunnel junction. Still other layers of tunnel barrier and magnetic material may be used in combination with the foregoing to form a flux-closed double tunnel junction device.
Type:
Grant
Filed:
May 16, 2005
Date of Patent:
June 12, 2007
Assignee:
International Business Machines Corporation
Inventors:
Christian Kaiser, Stuart Stephen Papworth Parkin