Engineered magnetic layer with improved perpendicular anisotropy using glassing agents for spintronic applications

A domain wall motion device, comprising:

• (a) a pinned magnetic layer having a first width;
• (b) a tunnel barrier contacting a top surface of the pinned layer;
• (c) a free layer having a width substantially larger than the first width, and forming a first interface with the tunnel barrier layer and a second interface with a perpendicular Hk enhancing layer formed on a surface of the free layer that is opposite a surface at the first interface, there is a first glassing agent concentration in a middle portion of the free layer and a second glassing agent concentration less than the first glassing agent concentration but greater than zero in portions of the free layer proximate to the first and second interfaces, and wherein domain walls extend vertically between first and second interfaces to establish magnetic domains including a switchable magnetic domain aligned above the pinned magnetic layer;
• (d) the perpendicular Hk enhancing layer;
• and
• (e) a capping layer that contacts a top surface of the perpendicular Hk enhancing layer, the domain wall motion device is electrically connected to a current/voltage source and to a readout device to enable read and write processes.

A method of forming a MTJ element exhibiting interfacial perpendicular anisotropy at a first interface between a free layer and an adjoining tunnel barrier layer and at a second interface between the free layer and an adjoining perpendicular Hk enhancing layer, comprising:

• (a) providing a pinned layer formed on a substrate;
• (b) forming a tunnel barrier layer on the pinned layer;
• (c) depositing a free layer having a bottom surface that forms a first interface with a top surface of said tunnel barrier, and having a top surface that forms a second interface with a subsequently deposited perpendicular Hk enhancing layer, the free layer comprises a first glassing agent concentration in a middle portion thereof that crystallizes at a first temperature, and a second glassing agent concentration less than the first concentration but greater than zero in top and bottom portions of the ferromagnetic layer proximate to the first and second interfaces such that the top and bottom portions crystallize at a second temperature less than the first temperature;
• (d) forming the perpendicular Hk enhancing layer on the free layer;
• (e) forming a capping layer that contacts a top surface of the perpendicular Hk enhancing layer;
• and
• (f) performing an anneal process.

A magnetic tunnel junction (MTJ) element including a ferromagnetic layer with at least two interfaces that produce interfacial perpendicular anisotropy, comprising:

• (a) a tunnel barrier layer;
• (b) the ferromagnetic layer that has a first interface with said tunnel barrier layer and a second interface with a perpendicular Hk enhancing layer formed on a surface of the ferromagnetic layer that is opposite a surface adjoining the tunnel barrier layer, the ferromagnetic layer comprises a first glassing agent (G) made of Si, Ta, P, Nb, Hf, Ti, Pd, Be, Cr, Zr, Cu, Os, V, or Mg, and a second glassing agent (B) wherein a first concentration of glassing agents (G+B) in a middle portion of the ferromagnetic layer is greater than a second concentration of glassing agents (G+B) in portions of the ferromagnetic layer proximate to the first and second interfaces;
• and
• (c) the perpendicular Hk enhancing layer.

A magnetic tunnel junction (MTJ) element including a ferromagnetic layer with at least two interfaces that produce interfacial perpendicular anisotropy, comprising:

• (a) a tunnel barrier layer;
• (b) the ferromagnetic layer that has a first interface with said tunnel barrier layer and a second interface with a perpendicular Hk enhancing layer formed on a surface of the ferromagnetic layer that is opposite a surface adjoining the tunnel barrier layer, the ferromagnetic layer has a magnetic alloy/G/magnetic alloy configuration wherein a glassing agent (G) made of Si, Ta, P, Nb, Hf, Ti, Pd, Be, Cr, Zr, Cu, Os, V, or Mg has a first concentration in the G layer and a second concentration less than the first concentration in the alloy portions of the ferromagnetic layer proximate to the first and second interfaces, the glassing agent is deposited as a single layer or as a laminate wherein each glassing agent layer is from 0.1 to 5 Angstroms thick;
• and
• (c) the perpendicular Hk enhancing layer.

A domain wall motion device, comprising:

• (a) a pinned magnetic layer having a first width;
• (b) a tunnel barrier contacting a top surface of the pinned layer;
• (c) a free layer having a magnetic alloy/G/magnetic alloy configuration and a width substantially larger than the first width, and forming a first interface with the tunnel barrier layer and a second interface with a perpendicular Hk enhancing layer formed on a surface of the free layer that is opposite a surface at the first interface, there is a glassing agent (G) made of Si, Ta, P, Nb, Hf, Ti, Pd, Be, Cr, Zr, Cu, Os, V, or Mg with a first concentration in the middle G layer and with a second concentration less than the first concentration in the magnetic alloy portions of the free layer proximate to the first and second interfaces, the glassing agent is deposited as a single layer or as a laminate wherein each glassing agent layer is from 0.1 to 5 Angstroms thick, and wherein domain walls extend vertically between first and second interfaces to establish magnetic domains including a switchable magnetic domain aligned above the pinned magnetic layer;
• (d) the perpendicular Hk enhancing layer;
• and
• (e) a capping layer that contacts a top surface of the perpendicular Hk enhancing layer, the domain wall motion device is electrically connected to a current/voltage source and to a readout device to enable read and write processes.

A method of forming a MTJ element exhibiting interfacial perpendicular anisotropy at a first interface between a ferromagnetic layer and an adjoining tunnel barrier layer and at a second interface between the ferromagnetic layer and an adjoining perpendicular Hk enhancing layer, comprising:

• (a) providing the tunnel barrier layer formed on a substrate;
• (b) depositing the ferromagnetic layer having a bottom surface that forms a first interface with a top surface of said tunnel barrier, and having a top surface that forms a second interface with a subsequently deposited perpendicular Hk enhancing layer, the ferromagnetic layer has a magnetic alloy/G/magnetic alloy configuration with a middle layer made of a glassing agent that is Si, Ta, P, Nb, Hf, Ti, Pd, Be, Cr, Zr, Cu, Os, V, or Mg with a first concentration that crystallizes at a first temperature, and wherein the magnetic alloy layers have a second glassing agent concentration less than the first concentration that crystallize at a second temperature less than the first temperature, and wherein the glassing agent (G) is deposited as a single layer or as a laminated configuration in which each glassing agent layer is from 0.1 to 5 Angstroms thick;
• (c) forming the perpendicular Hk enhancing layer on the ferromagnetic layer;
• and
• (d) performing an anneal process.