Neuromorphic devices of heusler alloy based spin-transfer-torque magnetic tunnel junctions

A magnetic tunnel junction device, the device comprising:

• a substrate;
• a seed layer overlying the substrate;
• a nitride layer, overlying the seed layer;
• a templating layer, outward of the nitride layer, comprising a binary alloy having an alternating layer lattice structure, and having a thickness greater than 50 Angstroms;
• a magnetic layer overlying the templating layer, the magnetic layer comprising a Heusler compound and exhibiting perpendicular magnetic anisotropy (PMA);
• a tunnel barrier outward of the magnetic layer;
• and
• a magnetic layer outward of the tunnel barrier,
• wherein the device size is greater than 50 nm.

A hardware description language (HDL) design structure encoded on a machine-readable data storage medium, the HDL design structure comprising elements that when processed in a computer-aided design system generates a machine-executable representation of a neuromorphic computing array, wherein the (HDL design structure) comprises:

• a plurality of horizontal lines;
• a plurality of vertical lines intersecting the plurality of horizontal lines at a plurality of cell locations;
• and
• a plurality of magnetic tunnel junction cells located at each of the plurality of cell locations, each of the magnetic tunnel junction cells being electrically connected to a corresponding one of the horizontal lines and to a corresponding one of the vertical lines, each of the plurality of magnetic tunnel junction cells comprising:
• a substrate;
• a seed layer overlying the substrate;
• a nitride layer, overlying the seed layer;
• a templating layer, outward of the nitride layer, comprising a binary alloy having an alternating layer lattice structure, and having a thickness greater than 50 Angstroms;
• a magnetic layer overlying the templating layer, the magnetic layer comprising a Heusler compound and exhibiting perpendicular magnetic anisotropy (PMA);
• a tunnel barrier outward of the magnetic layer;
• a magnetic layer outward of the tunnel barrier;
• and
• a capping layer outward of the magnetic layer,
• wherein, without the use of an intervening transistor:
• the seed layer of each of the plurality of magnetic tunnel junction cells is coupled to the corresponding one of the horizontal lines and the capping layer is coupled to the corresponding one of the vertical lines;
• and
• the corresponding one of the horizontal lines and the corresponding one of the vertical lines are configured to supply electrical signals to each of the plurality of magnetic tunnel junction cells.

A method of training a neuromorphic computing array, comprising:

• providing a neuromorphic computing array, the array comprising:
• a plurality of horizontal lines;
• a plurality of vertical lines intersecting the plurality of horizontal lines at a plurality of cell locations;
• and
• a plurality of magnetic tunnel junction cells located at each of the plurality of cell locations, each of the magnetic tunnel junction cells being electrically connected to a corresponding one of the horizontal lines and to a corresponding one of the vertical lines, each of the plurality of magnetic tunnel junction cells comprising:
• a substrate;
• a seed layer overlying the substrate;
• a nitride layer, overlying the seed layer;
• a templating layer, outward of the nitride layer, comprising a binary alloy having an alternating layer lattice structure, and having a thickness greater than 50 Angstroms;
• a magnetic layer overlying the templating layer, the magnetic layer comprising a Heusler compound and exhibiting perpendicular magnetic anisotropy (PMA);
• a tunnel barrier outward of the magnetic layer;
• a magnetic layer outward of the tunnel barrier;
• and
• a capping layer outward of the magnetic layer,
• wherein, without the use of an intervening transistor, the seed layer of each of the plurality of magnetic tunnel junction cells is coupled to the corresponding one of the horizontal lines and the capping layer is coupled to the corresponding one of the vertical lines;
• simultaneously applying input voltage signals along the plurality of horizontal lines during a forward training pass;
• obtaining output current signals along the plurality of vertical lines during the forward training pass;
• and
• applying input voltage signals, corresponding to difference between the output current signals and predicted values, along the plurality of vertical lines during a backward training pass.

A method of forming a magnetic tunnel junction device, comprising:

• providing a substrate;
• forming a seed layer overlying the substrate;
• forming a nitride layer overlying the seed layer;
• providing a templating layer, outward of the nitride layer, and comprising a binary alloy having an alternating layer lattice structure, and having a thickness greater than 50 Angstroms;
• epitaxially growing a magnetic layer on the templating layer, the magnetic layer comprising a Heusler compound and exhibiting perpendicular magnetic anisotropy (PMA);
• forming a tunnel barrier outward of the magnetic layer;
• and
• forming a magnetic layer outward of the tunnel barrier,
• wherein the magnetic tunnel junction device size is greater than 50 nm.