Magneto-resistive memory cell structures with improved selectivity
AssigneeMicron Technology, Inc.
InventorsTheodore Zhu, Yong Lu, Anthony Arrott
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Abstract
A magneto-resistive memory comprising magneto-resistive memory cells is disclosed, comprising two pinned magnetic layers on one side of a free magnetic layer. The pinned magnetic layers are formed with anti-parallel magnetization orientations such that a net magnetic moment of the two layers is substantially zero. The influence of pinned magnetic layers on free magnetic layer magnetization orientations is substantially eliminated, allowing for increased predictability in switching behavior and increased write selectivity of memory cells.
Claims32
A magneto-resistive memory cell, comprising:
- a free magnetic layer;
- a non-magnetic interlayer, wherein the non-magnetic interlayer comprises a conductor and is in contact with the free magnetic layer;
- a pinned magnetic layer, wherein the pinned magnetic layer is in contact with the non-magnetic interlayer;
- and
- an additional pinned magnetic layer, wherein the pinned magnetic layer is between the free magnetic layer and the additional pinned magnetic layer and wherein a magnetization orientation of the pinned magnetic layer is substantially anti-parallel to a magnetization orientation of the additional pinned magnetic layer such that a magnitude of a net magnetic field from the pinned magnetic layer and the additional pinned magnetic layer is too small to substantially affect a magnetization orientation of the free magnetic layer.
A magneto-resistive memory cell in an integrated circuit, comprising:
- a free magnetic layer;
- and
- a pair of pinned magnetic layers on one side of the free magnetic layer, wherein a layer comprising ruthenium separates the two pinned magnetic layers forming the pair and wherein magnetization orientations of the two pinned magnetic layers are anti-parallel such that a first magnitude of an applied magnetic field for switching a magnetization orientation of the free magnetic layer in one direction is substantially equal to a second magnitude of an applied magnetic field for switching the magnetization orientation of the free magnetic layer in a substantially opposite direction.
A magneto-resistive memory comprising an array of magneto-resistive memory cells, each cell having substantially symmetrical switching field thresholds and comprising:
- a free magnetic layer;
- a non-magnetic interlayer on one side of the free magnetic layer, wherein the non-magnetic interlayer comprises a conductor and is in contact with the free magnetic layer;
- and
- a pair of pinned magnetic layers, wherein magnetization orientations of the pair of layers is anti-parallel such that a net magnetic moment of the pair of layers is substantially zero.
A method of constructing a magneto-resistive memory cell, comprising:
- selecting a ferromagnetic material for a first magnetic layer;
- selecting an additional ferromagnetic material for a second magnetic layer;
- selecting thicknesses for each of the first magnetic layer and the second magnetic layer such that a magnitude of a magnetic field of the first magnetic layer is substantially equal to a magnitude of a magnetic field of the second magnetic layer;
- forming a non-magnetic interlayer, wherein the non-magnetic interlayer comprises copper;
- forming the first magnetic layer;
- forming the second magnetic layer;
- forming a first fixed magnetic layer by applying a first magnetic field to fix a magnetization orientation of the first magnetic layer;
- and
- forming a second fixed magnetic layer by applying a second magnetic field to fix a magnetization orientation of the second magnetic layer in an opposite direction from the magnetization orientation of the first magnetic layer.
A method of constructing a magneto-resistive memory cell, comprising:
- forming a first magnetic layer;
- forming a non-magnetic interlayer, wherein the non-magnetic interlayer comprises a conductor;
- forming a second magnetic layer without forming another magnetic layer between the first magnetic layer and the second magnetic layer;
- forming a first fixed magnetic layer by applying a first magnetic field to fix a magnetization orientation of the first magnetic layer;
- and
- forming a second fixed magnetic layer by applying a second magnetic field to fix a magnetization orientation of the second magnetic layer in an opposite direction from the magnetization orientation of the first magnetic layer, wherein a set of ferromagnetic and antiferromagnetic coupling fields of the second fixed magnetic layer balance an additional set of ferromagnetic and antiferromagnetic coupling fields from the first fixed magnetic layer.
Dependencies are inferred from the claim text.