Abstract: In one embodiment, the invention is a method and apparatus for fabricating sub-lithography data tracks for use in magnetic shift register memory devices. One embodiment of a memory device includes a first stack of dielectric material formed of a first dielectric material, a second stack of dielectric material surrounding the first stack of dielectric material and formed of at least a second dielectric material, and at least one data track for storing information, positioned between the first stack of dielectric material and the second stack of dielectric material, the data track having a high aspect ratio and a substantially rectangular cross section.

Abstract: Magnetic tunnel junctions are constructed from a MgO or Mg—ZnO tunnel barrier and amorphous magnetic layers in proximity with, and on respective sides of, the tunnel barrier. The amorphous magnetic layer preferably includes Co and at least one additional element selected to make the layer amorphous, such as boron. Magnetic tunnel junctions formed from the amorphous magnetic layers and the tunnel barrier have tunneling magnetoresistance values of up to 200% or more.

Abstract: A magnetic tunneling element is constructed from a MgO or Mg—ZnO tunnel barrier and an amorphous magnetic layer in proximity with the tunnel barrier. The amorphous magnetic layer includes Co and at least one additional element selected to make the layer amorphous. Magnetic tunnel junctions formed from the amorphous magnetic layer, the tunnel barrier, and an additional ferromagnetic layer have tunneling magnetoresistance values of up to 200% or more.

Abstract: MgO tunnel barriers are formed by depositing a thin layer of Mg on a suitable underlayer, and then directing oxygen and additional Mg towards the Mg layer. The oxygen reacts with the additional Mg and the Mg in the Mg layer to form a MgO tunnel barrier that enjoys excellent tunneling characteristics. The MgO tunnel barriers so formed may be used in magnetic tunnel junctions having tunneling magnetoresistance (TMR) values of greater than 100%. The highest TMR values are observed for junctions that have been annealed and that have a (100) crystallographic orientation.

Abstract: A magnetic memory element switchable by current injection includes a plurality of magnetic layers, at least one of the plurality of magnetic layers having a perpendicular magnetic anisotropy component and including a current-switchable magnetic moment, and at least one barrier layer formed adjacent to the plurality of magnetic layers (e.g., between two of the magnetic layers). The memory element has the switching threshold current and device impedance suitable for integration with complementary metal oxide semiconductor (CMOS) integrated circuits.

Abstract: ZnMg oxide tunnel barriers are grown which, when sandwiched between ferri- or ferromagnetic layers, form magnetic tunnel junctions exhibiting high tunneling magnetoresistance (TMR). The TMR may be increased by annealing the magnetic tunnel junctions. The zinc-magnesium oxide tunnel barriers may be incorporated into a variety of other devices, such as magnetic tunneling transistors and spin injector devices. The ZnMg oxide tunnel barriers are grown by first depositing a zinc and/or magnesium layer onto an underlying substrate in oxygen-poor (or oxygen-free) conditions, and subsequently depositing zinc and/or magnesium onto this layer in the presence of reactive oxygen.

Abstract: A magnetic memory element switchable by current injection includes a plurality of magnetic layers, at least one of the plurality of magnetic layers having a perpendicular magnetic anisotropy component and including a current-switchable magnetic moment, and at least one barrier layer formed adjacent to the plurality of magnetic layers (e.g., between two of the magnetic layers). The memory element has the switching threshold current and device impedance suitable for integration with complementary metal oxide semiconductor (CMOS) integrated circuits.

Abstract: MgO tunnel barriers are formed by depositing a thin layer of Mg on a suitable underlayer, and then directing oxygen and additional Mg towards the Mg layer. The oxygen reacts with the additional Mg and the Mg in the Mg layer to form a MgO tunnel barrier that enjoys excellent tunneling characteristics. The MgO tunnel barriers so formed may be used in magnetic tunnel junctions having tunneling magnetoresistance (TMR) values of greater than 100%. The highest TMR values are observed for junctions that have been annealed and that have a (100) crystallographic orientation.

Abstract: Magnetic tunnel junctions are disclosed that include ferromagnetic (or ferrimagnetic) materials and a bilayer tunnel barrier structure. The bilayer includes a crystalline material, such as MgO or Mg—ZnO, and Al2O3, which may be amorphous. If MgO is used, then it is preferably (100) oriented. The magnetic tunnel junctions so formed enjoy high tunneling magnetoresistance, e.g., greater than 100% at room temperature.

Abstract: A racetrack memory storage device moves domain walls along the racetrack in one direction only. The reading element can be positioned at one end of the racetrack (rather than in the middle of the racetrack). The domain walls are annihilated upon moving them across the reading element but their corresponding information is read into one or more memory devices (e.g., built-in CMOS circuits). The information can then be processed in circuits for computational needs and written back into the racetrack either in its original form (as it was read out of the racetrack) or in a different form after some computation, using a writing element positioned at the end of the racetrack opposite to the reading element. Such a racetrack can be built more simply and has greater reliability of operation than previous racetrack memory devices.

Abstract: A MgO tunnel barrier is sandwiched between semiconductor material on one side and a ferri- and/or ferromagnetic material on the other side to form a spintronic element. The semiconductor material may include GaAs, for example. The spintronic element may be used as a spin injection device by injecting charge carriers from the magnetic material into the MgO tunnel barrier and then into the semiconductor. Similarly, the spintronic element may be used as a detector or analyzer of spin-polarized charge carriers by flowing charge carriers from the surface of the semiconducting layer through the MgO tunnel barrier and into the (ferri- or ferro-) magnetic material, which then acts as a detector. The MgO tunnel barrier is preferably formed by forming a Mg layer on an underlayer (e.g., a ferromagnetic layer), and then directing additional Mg, in the presence of oxygen, towards the underlayer.

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.

Abstract: In one embodiment, the invention is a method and apparatus for fabricating sub-lithography data tracks for use in magnetic shift register memory devices. One embodiment of a memory device includes a first stack of dielectric material formed of a first dielectric material, a second stack of dielectric material surrounding the first stack of dielectric material and formed of at least a second dielectric material, and at least one data track for storing information, positioned between the first stack of dielectric material and the second stack of dielectric material, the data track having a high aspect ratio and a substantially rectangular cross section.

Abstract: Magnetic tunnel junctions are disclosed that include ferromagnetic (or ferrimagnetic) materials and a bilayer tunnel barrier structure. The bilayer includes a crystalline material, such as MgO or Mg—ZnO, and Al2O3, which may be amorphous. If MgO is used, then it is preferably (100) oriented. The magnetic tunnel junctions so formed enjoy high tunneling magnetoresistance, e.g., greater than 100% at room temperature.

Abstract: Magnetic tunnel junctions are disclosed that include ferromagnetic (or ferrimagnetic) materials and a bilayer tunnel barrier structure. The bilayer includes a crystalline material, such as MgO or Mg—ZnO, and Al2O3, which may be amorphous. If MgO is used, then it is preferably (100) oriented. The magnetic tunnel junctions so formed enjoy high tunneling magnetoresistance, e.g., greater than 100% at room temperature.

Abstract: Magnetic tunnel junctions are constructed from a MgO or Mg—ZnO tunnel barrier and amorphous magnetic layers in proximity with, and on respective sides of, the tunnel barrier. The amorphous magnetic layer preferably includes Co and at least one additional element selected to make the layer amorphous, such as boron. Magnetic tunnel junctions formed from the amorphous magnetic layers and the tunnel barrier have tunneling magnetoresistance values of up to 200% or more.

Abstract: Magnetic tunneling devices are formed from a first body centered cubic (bcc) magnetic layer and a second bcc magnetic layer. At least one spacer layer of bcc material between these magnetic layers exchange couples the first and second bcc magnetic layers. A tunnel barrier in proximity with the second magnetic layer permits spin-polarized current to pass between the tunnel barrier and the second layer; the tunnel barrier may be either MgO and Mg—ZnO. The first magnetic layer, the spacer layer, the second magnetic layer, and the tunnel barrier are all preferably (100) oriented. The MgO and Mg—ZnO tunnel barriers are prepared by first depositing a metallic layer on the second magnetic layer (e.g., a Mg layer), thereby substantially reducing the oxygen content in this magnetic layer, which improves the performance of the tunnel barriers.

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.

Abstract: A MgO tunnel barrier is sandwiched between semiconductor material on one side and a ferri- and/or ferromagnetic material on the other side to form a spintronic element. The semiconductor material may include GaAs, for example. The spintronic element may be used as a spin injection device by injecting charge carriers from the magnetic material into the MgO tunnel barrier and then into the semiconductor. Similarly, the spintronic element may be used as a detector or analyzer of spin-polarized charge carriers by flowing charge carriers from the surface of the semiconducting layer through the MgO tunnel barrier and into the (ferri- or ferro-) magnetic material, which then acts as a detector. The MgO tunnel barrier is preferably formed by forming a Mg layer on an underlayer (e.g., a ferromagnetic layer), and then directing additional Mg, in the presence of oxygen, towards the underlayer.

Abstract: ZnMg oxide tunnel barriers are grown which, when sandwiched between ferri- or ferromagnetic layers, form magnetic tunnel junctions exhibiting high tunneling magnetoresistance (TMR). The TMR may be increased by annealing the magnetic tunnel junctions. The zinc-magnesium oxide tunnel barriers may be incorporated into a variety of other devices, such as magnetic tunneling transistors and spin injector devices. The ZnMg oxide tunnel barriers are grown by first depositing a zinc and/or magnesium layer onto an underlying substrate in oxygen-poor (or oxygen-free) conditions, and subsequently depositing zinc and/or magnesium onto this layer in the presence of reactive oxygen.