Everspin Technologies, Inc.

The present disclosure is drawn to, among other things, a storage device. The storage device may include a magnetic tunnel junction (MTJ)-based storage array and a communication interface. The MTJ-based storage array may be configured to be damaged by a shorting voltage based on detection of a tamper event.

A magnetoresistive stack may include a first electrically conductive material, a fixed region having a fixed magnetic state, a free region configured to have a first magnetic state and a second magnetic state, a dielectric layer disposed between the fixed region and the free region, a spacer region, and a cap layer disposed between the spacer region and the free region. The free region may include a layer of ferromagnetic material, an insertion layer, an iPMA layer, and/or a low saturation magnetization layer.

A magnetically free region of magnetoresistive device includes at least a first ferromagnetic region and a second ferromagnetic region separated by a non-magnetic insertion region. At least one of the first ferromagnetic region and the second ferromagnetic region may include at least a layer including boron and a non-boron magnetic material positioned proximate a boron-free ferromagnetic layer.

A method of fabricating a magnetoresistive bit from a magnetoresistive stack includes (a) etching through at least a portion of a thickness of the surface region to create a first set of exposed areas in the form of multiple strips extending in a first direction, and (b) etching through at least a portion of a thickness of the surface region to create a second set of exposed areas in the form of multiple strips extending in a second direction. The first set of exposed areas and the second set of exposed areas may have multiple areas that overlap. The method may also include, (c) after the etching in (a) and (b), etching through at least a portion of the thickness of the magnetoresistive stack through the first set and second set of exposed areas.

A method for programming a configuration bit including magnetic tunnel junctions (MTJs), including during a first phase: applying a first voltage to a first leg of MTJs and a third leg of MTJs to program or inhibit the MTJs of the first leg and the third leg, and applying a second voltage to a second leg of MTJs and a fourth leg of MTJs to program or inhibit the MTJs of the second leg and the fourth leg. During a second phase: applying the second voltage to the first leg of MTJs and the third leg of MTJs to program or inhibit the MTJs of the first leg and the third leg, and applying the first voltage to the second leg of MTJs and the fourth leg of MTJs to program or inhibit the MTJs of the second leg and the fourth leg.

1. The present disclosure is drawn to, among other things, a method for accessing memory using dual standby modes, the method including receiving a first standby mode indication selecting a first standby mode from a first standby mode or a second standby mode, configuring a read bias system to provide a read bias voltage and a write bias system to provide approximately no voltage, or any voltage outside the necessary range for write operation, based on the first standby mode, receiving a second standby mode indication selecting the second standby mode, and configuring the read bias system to provide at least the read bias voltage and the write bias system to provide a write bias voltage based on the second standby mode, the read bias voltage being lower than the write bias voltage.

A method of fabricating a magnetoresistive bit from a magnetoresistive stack includes etching through a first portion of the magnetoresistive stack using a first etch process to form one or more sidewalls. At least a portion of the sidewalls includes redeposited material after the etching. The method also includes modifying at least a portion of the redeposited material on the sidewalls, and etching through a second portion of the magnetoresistive stack after the modifying step. The magnetoresistive stack may include a first magnetic region, an intermediate region disposed over the first magnetic region, and a second magnetic region disposed over the intermediate region.

Aspects of the present disclosure are directed to magnetoresistive stacks including regions having increased height-to-diameter ratios. Exemplary magnetoresistive stacks (for example, used in a magnetic tunnel junction (MTJ) magnetoresistive device) of the present disclosure include one or more multilayer synthetic antiferromagnetic structures (SAFs) or synthetic ferromagnetic structures (SyFs) in order to promote stability of the SAF or SyF, e.g., for smaller-sized MTJs.

A memory includes a plurality of magnetoresistive devices, wherein each magnetoresistive device includes a fixed magnetic layer, a free magnetic layer, a tunnel barrier disposed between the fixed and free magnetic layers, and an insertion layer disposed below the free magnetic layer, wherein the fixed magnetic layer is formed above the free magnetic layer. The memory also includes a plurality of antiferromagnetic layers, wherein each antiferromagnetic layer is disposed above a seed layer. The memory further includes a spin-orbit-torque (SOT) channel, wherein the SOT channel is disposed between the plurality of magnetoresistive devices and the plurality of antiferromagnetic layers.

A method of fabricating a magnetoresistive bit from a magnetoresistive stack includes (a) etching through at least a portion of a thickness of the surface region to create a first set of exposed areas in the form of multiple strips extending in a first direction, and (b) etching through at least a portion of a thickness of the surface region to create a second set of exposed areas in the form of multiple strips extending in a second direction. The first set of exposed areas and the second set of exposed areas may have multiple areas that overlap. The method may also include, (c) after the etching in (a) and (b), etching through at least a portion of the thickness of the magnetoresistive stack through the first set and second set of exposed areas.