Multi-level magnetic tunnel junction (MTJ) devices including mobile magnetic skyrmions or ferromagnetic domains

An apparatus comprising:

• first circuitry to switch a magnetization direction of a free magnet in a magnetic tunneling junction (MTJ) device by driving a first electrical current between a first and second electrode of the MTJ device;
• second circuitry to induce a first translation of a magnetic skyrmion or ferromagnetic domain within a magnetic material layer in the MTJ device toward the free magnet by driving a second electrical current between the first or second electrode and a third electrode of the MTJ device coupled to the magnetic material layer, and to induce a second translation of a magnetic skyrmion or ferromagnetic domain within the magnetic material layer away from the free magnet by driving a third electrical current between the first or second electrode and the third electrode;
• and
• third circuitry to detect one of a plurality of resistance states associated with a position of the magnetic skyrmion within the magnetic material relative to the free magnet.

A method of operating a memory device, the method comprising:

• switching a magnetization direction of a free magnet in a magnetic tunneling junction (MTJ) device by driving a first electrical current between a first and second electrode of the MTJ device;
• translating a magnetic skyrmion or magnetic domain over a length of a magnetic material of the MTJ device toward the free magnet with a second electrical current driven in a first direction between a third electrode coupled with the magnetic material and the first or second electrode;
• translating the magnetic skyrmion or magnetic domain over the length of the magnetic material away from the free magnet with a third electrical current driven in a second direction, opposite the first direction, between the third electrode and the first or second electrode;
• and
• detecting one of a plurality of resistance states of the memory device, wherein the resistance states are associated with an orientation of magnetization of the free magnet and a position of the magnetic skyrmion or magnetic domain within the magnetic material layer.

A method of fabricating a memory device, the method comprising:

• forming a first electrode;
• fabricating a booster coupled to the first electrode, the booster comprising a magnetic material layer and an interface layer;
• forming an MTJ stack coupled to the booster, the forming comprising:
• depositing a free magnet layer above the booster;
• depositing a tunnel barrier layer over the free magnet layer;
• depositing a fixed magnet layer over the tunnel barrier layer;
• depositing a spacer layer over the fixed magnet layer;
• forming a second electrode coupled to the spacer layer;
• and
• forming a third electrode coupled to the booster, wherein fabricating the booster further comprises patterning the magnetic material layer and the interface layer to have a first lateral length that is longer than a second lateral length of the MTJ stack by an amount at least equal to a lateral length of a magnetic skyrmion or ferromagnetic domain that is to be translated within the magnetic material over the first lateral length in response to an electrical current passed through the third electrode.