Multi-resistance mram
AssigneeSanDisk Technologies LLC
InventorsYOUNG-SUK CHOI, WON HO CHOI
Life of this patent
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Abstract
Apparatuses, systems, and methods are disclosed for magnetoresistive random access memory. A magnetic tunnel junction (MTJ) for storing data may include a reference layer. A free layer of an MTJ may be separated from a reference layer by a barrier layer. A free layer may be configured such that one or more resistance states for an MTJ correspond to one or more positions of a magnetic domain wall within the free layer. A domain stabilization layer may be coupled to a portion of a free layer, and may be configured to prevent migration of a domain wall into the portion of the free layer.
Claims26
An apparatus comprising:
- a magnetic tunnel junction (MTJ) for storing data, the magnetic tunnel junction comprising:
- a reference layer;
- a free layer separated from the reference layer by a barrier layer, the free layer configured such that one or more resistance states for the MTJ correspond to one or more positions of a magnetic domain wall within the free layer;
- and
- a domain stabilization layer coupled to a portion of the free layer, the domain stabilization layer configured to prevent migration of the domain wall into the portion of the free layer.
A system comprising:
- a neuromorphic computing die, the neuromorphic computing die comprising a plurality of artificial neurons and a synapse array of multi-state magnetic memory cells coupling the artificial neurons, wherein a multi-state magnetic memory cell comprises:
- a fixed layer;
- a magnetic storage layer separated from the fixed layer by a barrier layer, the magnetic storage layer configured such that one or more states for the multi-state magnetic memory cell correspond to one or more positions of a magnetic domain wall within the magnetic storage layer;
- and
- a domain stabilization layer coupled to a portion of the magnetic storage layer, the domain stabilization layer configured to provide a fixed magnetization for the portion of the magnetic storage layer.
An apparatus comprising:
- means for moving a magnetic domain wall in a free layer for a magnetic tunnel junction;
- means for preventing the magnetic domain wall from entering a portion of the free layer.
An apparatus comprising:
- a magnetoresistive random access memory (MRAM) die, the MRAM die comprising a plurality of memory cells, a memory cell comprising a fixed layer, a barrier layer, and a free layer, the barrier layer disposed between the fixed layer and the free layer, the free layer comprising:
- a wall extension region configured to provide a plurality of resistance states for the memory cell corresponding to positions of a magnetic domain wall within the wall extension region;
- and
- an end region configured to exclude the domain wall.
A method comprising:
- applying a first write current to a magnetic tunnel junction to move a magnetic domain wall to a pinning site in a wall extension region of a free layer of the magnetic tunnel junction;
- applying a second write current to the magnetic tunnel junction to move the domain wall from the pinning site to a boundary between the wall extension region and an end region of the free layer;
- applying a third write current to the magnetic tunnel junction to move the domain wall back to the pinning site.
Dependencies are inferred from the claim text.