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US 11,152,048 B1Granted
Tunneling metamagnetic resistance memory device and methods of operating the same
AssigneeWestern Digital Technologies, Inc.
InventorsBhagwati Prasad, Alan Kalitsov
Life of this patent
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Abstract
A magnetoresistive memory device includes a first electrode, a second electrode, and a layer stack located between the first electrode and the second electrode. The layer stack may include a ferroelectric material layer and a metamagnetic tunnel junction containing a metamagnetic material layer, an insulating barrier layer, and a metallic material layer. Alternatively, the layer stack may include a multiferroic material layer, the metamagnetic material layer, the insulating barrier layer, and a reference magnetization layer.
Claims19
A magnetoresistive memory device, comprising:
- a first electrode;
- a second electrode;
- and
- a layer stack located between the first electrode and the second electrode, the layer stack comprising a multiferroic material layer and a metamagnetic tunnel junction, wherein the metamagnetic tunnel junction comprises:
- a metamagnetic material layer;
- a reference magnetization layer;
- and
- an insulating barrier layer between the reference magnetization layer and the metamagnetic material layer;
- and
- at least one feature comprising:
- (a) first feature wherein:
- the multiferroic material layer has a non-zero electric polarization that is coupled to a magnetization of the multiferroic material layer;
- the magnetization of the multiferroic material layer has a bistable configuration in which a first magnetization direction and a second magnetization direction are stable directions for the magnetization of the multiferroic material layer;
- and
- the second magnetization direction is antiparallel to the first magnetization direction;
- or
- (b) a second feature wherein the magnetic state of the metamagnetic material layer comprises a ferromagnetic state of the metamagnetic material layer, and the non-magnetic state of the metamagnetic material layer comprises a paramagnetic state or a diamagnetic state;
- or
- (c) a third feature further comprising a synthetic antiferromagnet structure comprising:
- the reference magnetization layer which comprises a soft ferromagnetic layer;
- a fixed magnetization layer that is spaced from the reference magnetization layer;
- and
- an antiferromagnetic coupling layer that antiferromagnetically couples a magnetization of reference magnetization layer to a magnetization of the fixed magnetization layer;
- or
- (d) a fourth feature further comprising a programming circuit that is configured:
- to apply a first programming pulse of a first polarity across the first electrode and the second electrode to program the metamagnetic material layer into the magnetic state;
- and
- to apply a second programming pulse of a second polarity that is an opposite of the first polarity across the first electrode and the second electrode to program the metamagnetic material layer into the non-magnetic state.
25 more elements
A magnetoresistive random access memory device, comprising:
- a two-dimensional array of instances of the magnetoresistive memory device comprising:
- a first electrode;
- a second electrode;
- and
- a layer stack located between the first electrode and the second electrode, the layer stack comprising a multiferroic material layer and a metamagnetic tunnel junction, wherein the metamagnetic tunnel junction comprises:
- a metamagnetic material layer;
- a reference magnetization layer;
- and
- an insulating barrier layer between the reference magnetization layer and the metamagnetic material layer;
- and
- word lines electrically connected to a respective subset of the first electrodes of the two-dimensional array;
- bit lines electrically connected to a respective subset of the second electrodes of the two-dimensional array;
- and
- a programming circuit connected to the bit lines and the word lines and configured to program the magnetoresistive memory device.
11 more elements
A method of operating a magnetoresistive memory device comprising:
- a first electrode;
- a second electrode;
- and
- a layer stack located between the first electrode and the second electrode, the layer stack comprising a multiferroic material layer and a metamagnetic tunnel junction, wherein the metamagnetic tunnel junction comprises:
- a metamagnetic material layer;
- a reference magnetization layer;
- and
- an insulating barrier layer between the reference magnetization layer and the metamagnetic material layer,
- the method comprising:
- applying a first polarity programming voltage to the first electrode relative to the second electrode in a first programming step to switch a state of the metamagnetic material layer from the non-magnetic state to the magnetic state;
- and
- applying a second polarity programming voltage having an opposite polarity of the first polarity programming voltage the first electrode relative to the second electrode in a second programming step to switch the state of the metamagnetic material layer from the magnetic state to the non-magnetic state.
9 more elements
Dependencies are inferred from the claim text.