Mg-Zn oxide tunnel barriers and method of formation
AssigneeInternational Business Machines Corporation
InventorStuart Stephen Papworth Parkin
Life of this patent
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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.
Claims22
A structure, comprising:
- a first magnetic layer including at least one material selected from the group consisting of ferromagnetic materials and ferrimagnetic materials;
- a magnesium-zinc oxide tunnel barrier;
- and
- a second magnetic layer including at least one material selected from the group consisting of ferromagnetic materials and ferrimagnetic materials, wherein the first magnetic layer, the tunnel barrier, and the second magnetic layer form a magnetic tunnel junction in which:
- i) the amount of any deleterious oxide in the magnetic tunnel junction is sufficiently low;
- and
- ii) the magnetic tunnel junction is sufficiently free of defects,
- that the tunnel magnetoresistance of the magnetic tunnel junction is greater than 50% at room temperature.
A structure, comprising:
- a first ferromagnetic layer that is bcc and substantially (100) oriented;
- a magnesium-zinc oxide tunnel barrier that is substantially (100) oriented;
- and
- a second ferromagnetic layer that is bcc and substantially (100) oriented, wherein the first ferromagnetic layer, the tunnel barrier, and the second ferromagnetic layer form a magnetic tunnel junction having a tunnel magnetoresistance greater than 50% at room temperature.
A structure, comprising:
- a first magnetic layer;
- a magnesium-zinc oxide tunnel barrier;
- and
- a second magnetic layer, wherein the first magnetic layer, the tunnel barrier, and the second magnetic layer are in proximity with each other and form a magnetic tunnel junction, thereby permitting spin-polarized current to pass through the structure, and in which:
- i) the amount of any deleterious oxide in the magnetic tunnel junction is sufficiently low;
- and
- ii) the magnetic tunnel junction is sufficiently free of defects,
- that the tunnel magnetoresistance of the magnetic tunnel junction is greater than 100% at room temperature.
A structure, comprising:
- a first magnetic layer;
- a magnesium-zinc oxide tunnel barrier;
- and
- a second magnetic layer, wherein the first magnetic layer, the tunnel barrier, and the second magnetic layer are in proximity with each other and form a magnetic tunnel junction having a tunnel magnetoresistance of greater than 70% at room temperature, wherein the magnesium-zinc oxide tunnel barrier includes material having the hexagonal wurtzite structure.
Dependencies are inferred from the claim text.