Double spin filter tunnel junction
AssigneeInternational Business Machines Corporation
InventorDaniel C. Worledge
Life of this patent
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Abstract
A memory device that includes a first magnetic insulating tunnel barrier reference layer present on a first non-magnetic metal electrode, and a free magnetic metal layer present on the first magnetic insulating tunnel barrier reference layer. A second magnetic insulating tunnel barrier reference layer may be present on the free magnetic metal layer, and a second non-magnetic metal electrode may be present on the second magnetic insulating tunnel barrier. The first and second magnetic insulating tunnel barrier reference layers are arranged so that their magnetizations are aligned to be anti-parallel.
Claims19
A memory device comprising:
- a substrate;
- a first magnetic insulating tunnel barrier reference layer having a magnetic insulating material on the substrate, the magnetic insulating material exhibiting an insulating property at room-temperature;
- a second magnetic insulating tunnel barrier reference layer on the first magnetic insulating tunnel barrier reference layer, the first and second magnetic insulating tunnel barrier reference layers each having a magnetization with a direction perpendicular to a major surface of the substrate and a magnetic polarization of at least 50% to reduce switching current;
- and
- a free magnetic metal layer, having a thickness between 5 Å and 10 Å, disposed directly between the first magnetic insulating tunnel barrier reference layer and the second magnetic insulating tunnel barrier reference layer, wherein a magnetic polarization of the free magnetic metal layer switches at current densities between 106 A/cm2 and 107 A/cm2.
A spin torque transfer magnetic random access memory device comprising:
- a magnetic tunnel junction stack between a pair of electrodes, wherein the magnetic tunnel junction stack comprises:
- a free magnetic metal layer having a thickness between 5 Å and 10 Å;
- a first magnetic insulating tunnel barrier reference layer, formed from magnetic insulating material that includes a spinel or garnet crystal structure, directly on a first face of the free magnetic metal layer and on a substrate, wherein the first magnetic insulating tunnel barrier reference layer has a magnetization with a direction perpendicular to a major surface of the substrate and a magnetic polarization of at least 50% to reduce switching current, the magnetic insulating material exhibiting an insulating property at room-temperature, wherein a magnetic polarization of the free magnetic metal layer switches at current densities between 106 A/cm2 and 107 A/cm2.
A memory device comprising:
- a first magnetic insulating tunnel barrier reference layer having a magnetic insulating material that comprises cobalt iron oxide (CoFeOx) with a thickness of 100 Å or less, the magnetic insulating material exhibiting an insulating property at room-temperature and having a magnetization in a first direction between 50 emu/cm3 and 600 emu/cm3;
- a first, non-magnetic metal electrode in direct contact with the first magnetic insulating tunnel barrier reference layer;
- a second magnetic insulating tunnel barrier reference layer on the first magnetic insulating tunnel barrier reference layer, with a thickness of 100 Å or less, having a magnetization in a second direction, opposite the first direction, the first and second magnetic insulating tunnel barrier reference layers each having a magnetic polarization of at least 90% to reduce switching current;
- a second, non-magnetic metal electrode in direct contact with the second magnetic insulating tunnel barrier reference layer;
- a free magnetic metal layer, comprising cobalt iron boron (CoFeB) having a thickness between 5 Å and 10 Å, disposed directly between the first magnetic insulating tunnel barrier reference layer and the second magnetic insulating tunnel barrier reference layer, wherein a magnetic polarization of the free magnetic metal layer switches at current densities between 106 A/cm2 and 107 A/cm2.
Dependencies are inferred from the claim text.