Abstract: A perpendicular magnetic tunnel junction is disclosed wherein a metal insertion (MIS) layer is formed within a free layer (FL), a partially oxidized Hk enhancing layer is on the FL, and a nitride capping layer having a buffer layer/nitride layer (NL) is on the Hk enhancing layer to provide an improved coercivity (Hc)/switching current (Jc) ratio for spintronic applications. Magnetoresistive ratio is maintained above 100%, resistance×area (RA) product is below 5 ohm/?m2, and thermal stability to 400° C. is realized. The FL comprises two or more sub-layers, and the MIS layer may be formed within at least one sub-layer or between sub-layers. The buffer layer is used to prevent oxygen diffusion to the NL, and nitrogen diffusion from the NL to the FL. FL thickness is from 11 Angstroms to 25 Angstroms while MIS layer thickness is preferably from 0.5 Angstroms to 4 Angstroms.

Abstract: A perpendicular magnetic tunnel junction is disclosed wherein first and second interfaces of a free layer (FL) with a first metal oxide (Hk enhancing layer) and second metal oxide (tunnel barrier), respectively, produce perpendicular magnetic anisotropy (PMA) to provide thermal stability to 400° C. Insertion of an oxidation control layer (OCL) such as Mg and a magnetic moment tuning layer (MMTL) like Mo or W enables FL thickness to be reduced below 10 Angstroms while providing sufficient PMA for a switching voltage substantially less than 500 mV at a 10 ns pulse width and 1 ppm defect rate. Magnetoresistive ratio is ?1, and resistance×area (RA) product is below 5 ohm-?m2. Embodiments are provided where MMTL and OCL materials interface with each other, or do not contact each other. Each of the MMTL and OCL materials may be deposited separately, or at least one is co-deposited with the FL.

Abstract: A magnetic element is disclosed wherein a composite seed layer such as TaN/Mg enhances perpendicular magnetic anisotropy (PMA) in an overlying magnetic layer that may be a reference layer, free layer, or dipole layer. The first seed layer is selected from one or more of Ta, Zr, Nb, TaN, ZrN, NbN, and Ru. The second seed layer is selected from one or more of Mg, Sr, Ti, Al, V, Hf, B, and Si. A growth promoting layer made of NiCr or an alloy thereof is inserted between the seed layer and magnetic layer. In some embodiments, a first composite seed layer/NiCr stack is formed below the reference layer, and a second composite seed layer/NiCr stack is formed between the free layer and a dipole layer. The magnetic element has thermal stability to at least 400° C.

Abstract: A perpendicularly magnetized magnetic tunnel junction (p-MTJ) is disclosed wherein a free layer (FL) has a first interface with a MgO tunnel barrier, a second interface with a Mo or W Hk enhancing layer, and is comprised of FexCoyBz wherein x is 66-80, y is 5-9, z is 15-28, and (x+y+z)=100 to simultaneously provide a magnetoresistive ratio >100%, resistance x area product <5 ohm/?m2, switching voltage <0.15V (direct current), and sufficient Hk to ensure thermal stability to 400° C. annealing. The FL may further comprise one or more M elements such as O or N to give (FexCoyBz)wM100-w where w is >90 atomic %. Alternatively, the FL is a trilayer with a FeB layer contacting MgO to induce Hk at the first interface, a middle FeCoB layer for enhanced magnetoresistive ratio, and a Fe or FeB layer adjoining the Hk enhancing layer to increase thermal stability.

Abstract: A ferromagnetic layer is capped with a metallic oxide (or nitride) layer that provides a perpendicular-to-plane magnetic anisotropy to the layer. The surface of the ferromagnetic layer is treated with a plasma to prevent diffusion of oxygen (or nitrogen) into the layer interior. An exemplary metallic oxide layer is formed as a layer of metallic Mg that is plasma treated to reduce its grain size and enhance the diffusivity of oxygen into its interior. Then the plasma treated Mg layer is naturally oxidized and, optionally, is again plasma treated to reduce its thickness and remove the oxygen rich upper surface.

Abstract: A magnetic device for magnetic random access memory (MRAM), spin torque MRAM, or spin torque oscillator technology is disclosed wherein a magnetic tunnel junction (MTJ) with a sidewall is formed between a bottom electrode and a top electrode. A passivation layer that is a single layer or multilayer comprising one of B, C, or Ge, or an alloy thereof wherein the B, C, and Ge content, respectively, is at least 10 atomic % is formed on the MTJ sidewall to protect the MTJ from reactive species during subsequent processing including deposition of a dielectric layer that electrically isolates the MTJ from adjacent MTJs, and during annealing steps around 400° C. in CMOS fabrication. The single layer is about 3 to 10 Angstroms thick and may be an oxide or nitride of B, C, or Ge. The passivation layer is preferably amorphous to prevent diffusion of reactive oxygen or nitrogen species.

Abstract: A magnetic element is disclosed wherein a composite seed layer such as TaN/Mg enhances perpendicular magnetic anisotropy (PMA) in an overlying magnetic layer that may be a reference layer, free layer, or dipole layer. The first seed layer is selected from one or more of Ta, Zr, Nb, TaN, ZrN, NbN, and Ru. The second seed layer is selected from one or more of Mg, Sr, Ti, Al, V, Hf, B, and Si. A growth promoting layer made of NiCr or an alloy thereof is inserted between the seed layer and magnetic layer. In some embodiments, a first composite seed layer/NiCr stack is formed below the reference layer, and a second composite seed layer/NiCr stack is formed between the free layer and a dipole layer. The magnetic element has thermal stability to at least 400° C.

Abstract: A perpendicularly magnetized magnetic tunnel junction (p-MTJ) is disclosed wherein a free layer (FL) has a first interface with a MgO tunnel barrier, a second interface with a Mo or W Hk enhancing layer, and is comprised of FexCoyBz wherein x is 66-80, y is 5-9, z is 15-28, and (x+y+z)=100 to simultaneously provide a magnetoresistive ratio >100%, resistance x area product <5 ohm/?m2, switching voltage <0.15 V (direct current), and sufficient Hk to ensure thermal stability to 400° C. annealing. The FL may further comprise one or more M elements such as O or N to give (FexCoyBz)wM100-w where w is >90 atomic %. Alternatively, the FL is a trilayer with a FeB layer contacting MgO to induce Hk at the first interface, a middle FeCoB layer for enhanced magnetoresistive ratio, and a Fe or FeB layer adjoining the Hk enhancing layer to increase thermal stability.

Abstract: A method of forming a MTJ with a tunnel barrier having a high tunneling magnetoresistance ratio, and low resistance x area value is disclosed. The method preserves perpendicular magnetic anisotropy in bottom and top magnetic layers that adjoin bottom and top surfaces of the tunnel barrier. A key feature is a passive oxidation step of a first Mg layer that is deposited on the bottom magnetic layer wherein a maximum oxygen pressure is 10-5 torr. A bottom portion of the first Mg layer remains unoxidized thereby protecting the bottom magnetic layer from substantial oxidation during subsequent oxidation and anneal processes that are employed to complete the fabrication of the tunnel barrier and MTJ. An uppermost Mg layer may be formed as the top layer in the tunnel barrier stack before a top magnetic layer is deposited.

Abstract: A synthetic antiferromagnetic structure for a spintronic device is disclosed and has an FL2/Co or Co alloy/antiferromagnetic coupling/Co or Co alloy/CoFeB configuration where FL2 is a ferromagnetic free layer with intrinsic PMA. Antiferromagnetic coupling is improved by inserting a Co or Co alloy dusting layer on top and bottom surfaces of the antiferromagnetic coupling layer. The FL2 layer may be a L10 ordered alloy, a rare earth-transition metal alloy, or an (A1/A2)n laminate where A1 is one of Co, CoFe, or an alloy thereof, and A2 is one of Pt, Pd, Rh, Ru, Ir, Mg, Mo, Os, Si, V, Ni, NiCo, and NiFe, or A1 is Fe and A2 is V. A method is also provided for forming the synthetic antiferromagnetic structure.

Abstract: A perpendicularly magnetized magnetic tunnel junction (p-MTJ) is disclosed wherein a boron containing free layer (FL) is subjected to a plasma treatment with inert gas, and a natural oxidation (NOX) process to form B2O3 before overlying layers are deposited. A metal layer such as Mg is deposited on the FL as a first step in forming a Hk enhancing layer that increases FL perpendicular magnetic anisotropy, or as a first step in forming a tunnel barrier layer on the FL. One or more anneal steps are essential in assisting B2O3 segregation from the free layer and thereby increasing the FL magnetic moment. A post-oxidation plasma treatment may also be used to partially remove B2O3 proximate to the FL top surface before the metal layer is deposited. Both plasma treatments use low power (<50 Watts) to remove a maximum of 2 Angstroms FL thickness.

Abstract: A ferromagnetic layer is capped with a metallic oxide (or nitride) layer that provides a perpendicular-to-plane magnetic anisotropy to the layer. The surface of the ferromagnetic layer is treated with a plasma to prevent diffusion of oxygen (or nitrogen) into the layer interior. An exemplary metallic oxide layer is formed as a layer of metallic Mg that is plasma treated to reduce its grain size and enhance the diffusivity of oxygen into its interior. Then the plasma treated Mg layer is naturally oxidized and, optionally, is again plasma treated to reduce its thickness and remove the oxygen rich upper surface.

Abstract: A magnetic device for magnetic random access memory (MRAM), spin torque MRAM, or spin torque oscillator technology is disclosed wherein a magnetic tunnel junction (MTJ) with a sidewall is formed between a bottom electrode and a top electrode. A passivation layer that is a single layer or multilayer comprising one of B, C, or Ge, or an alloy thereof wherein the B, C, and Ge content, respectively, is at least 10 atomic % is formed on the MTJ sidewall to protect the MTJ from reactive species during subsequent processing including deposition of a dielectric layer that electrically isolates the MTJ from adjacent MTJs, and during annealing steps around 400° C. in CMOS fabrication. The single layer is about 3 to 10 Angstroms thick and may be an oxide or nitride of B, C, or Ge. The passivation layer is preferably amorphous to prevent diffusion of reactive oxygen or nitrogen species.

Abstract: A perpendicularly magnetized magnetic tunnel junction (p-MTJ) is disclosed wherein a boron containing free layer (FL) is subjected to a plasma treatment with inert gas, and a natural oxidation (NOX) process to form B2O3 before overlying layers are deposited. A metal layer such as Mg is deposited on the FL as a first step in forming a Hk enhancing layer that increases FL perpendicular magnetic anisotropy, or as a first step in forming a tunnel barrier layer on the FL. One or more anneal steps are essential in assisting B2O3 segregation from the free layer and thereby increasing the FL magnetic moment. A post-oxidation plasma treatment may also be used to partially remove B2O3 proximate to the FL top surface before the metal layer is deposited. Both plasma treatments use low power (<50 Watts) to remove a maximum of 2 Angstroms FL thickness.

Abstract: A dual magnetic tunnel junction (DMTJ) is disclosed with a PL1/TB1/free layer/TB2/PL2/capping layer configuration wherein a first tunnel barrier (TB1) has a substantially lower resistance x area (RA1) product than RA2 for an overlying second tunnel barrier (TB2) to provide an acceptable net magnetoresistive ratio (DRR). Moreover, magnetizations in first and second pinned layers, PL1 and PL2, respectively, are aligned antiparallel to enable a lower critical switching current than when in a parallel alignment. An oxide capping layer having a RACAP is formed on PL2 to provide higher PL2 stability. The condition RA1<RA2 and RACAP<RA2 is achieved when TB1 and the oxide capping layer have one or both of a smaller thickness and a lower oxidation state than TB2, are comprised of conductive (metal) channels in a metal oxide or metal oxynitride matrix, or are comprised of a doped metal oxide or doped metal oxynitride layer.

Abstract: A magnetic tunnel junction (MTJ) is disclosed wherein a free layer (FL) interfaces with a first metal oxide (Mox) layer and second metal oxide (tunnel barrier) to produce perpendicular magnetic anisotropy (PMA) in the FL. In some embodiments, conductive metal channels made of a noble metal are formed in the Mox that is MgO to reduce parasitic resistance. In a second embodiment, a discontinuous MgO layer with a plurality of islands is formed as the Mox layer and a non-magnetic hard mask layer is deposited to fill spaces between adjacent islands and form shorting pathways through the Mox. In another embodiment, end portions between the sides of a center Mox portion and the MTJ sidewall are reduced to form shorting pathways by depositing a reducing metal layer on Mox sidewalls, or performing a reduction process with forming gas, H2, or a reducing species.

Abstract: A fabrication process for an STT MTJ MRAM device includes steps of cooling the device at individual or at multiple stages in its fabrication. The cooling process, which may be equally well applied during the fabrication of other multi-layered devices, is demonstrated to produce an operational device that is more resistant to adverse thermal effects during operation that would normally cause a similar device not so fabricated to lose stored data and otherwise fail to operate properly.

Abstract: A perpendicular magnetic tunnel junction is disclosed wherein first and second interfaces of a free layer (FL) with a first metal oxide (Hk enhancing layer) and second metal oxide (tunnel barrier), respectively, produce perpendicular magnetic anisotropy (PMA) to provide thermal stability to 400° C. Insertion of an oxidation control layer (OCL) such as Mg and a magnetic moment tuning layer (MMTL) like Mo or W enables FL thickness to be reduced below 10 Angstroms while providing sufficient PMA for a switching voltage substantially less than 500 mV at a 10 ns pulse width and 1 ppm defect rate. Magnetoresistive ratio is ?1, and resistance x area (RA) product is below 5 ohm-?m2. Embodiments are provided where MMTL and OCL materials interface with each other, or do not contact each other. Each of the MMTL and OCL materials may be deposited separately, or at least one is co-deposited with the FL.

Abstract: A perpendicular magnetic tunnel junction is disclosed wherein a metal insertion (MIS) layer is formed within a free layer (FL), a partially oxidized Hk enhancing layer is on the FL, and a nitride capping layer having a buffer layer/nitride layer (NL) is on the Hk enhancing layer to provide an improved coercivity (Hc)/switching current (Jc) ratio for spintronic applications. Magnetoresistive ratio is maintained above 100%, resistance×area (RA) product is below 5 ohm/?m2, and thermal stability to 400° C. is realized. The FL comprises two or more sub-layers, and the MIS layer may be formed within at least one sub-layer or between sub-layers. The buffer layer is used to prevent oxygen diffusion to the NL, and nitrogen diffusion from the NL to the FL. FL thickness is from 11 Angstroms to 25 Angstroms while MIS layer thickness is preferably from 0.5 Angstroms to 4 Angstroms.

Abstract: A synthetic antiferromagnetic structure for a spintronic device is disclosed and has an FL2/Co or Co alloy/antiferromagnetic coupling/Co or Co alloy/CoFeB configuration where FL2 is a ferromagnetic free layer with intrinsic PMA. Antiferromagnetic coupling is improved by inserting a Co or Co alloy dusting layer on top and bottom surfaces of the antiferromagnetic coupling layer. The FL2 layer may be a L10 ordered alloy, a rare earth-transition metal alloy, or an (A1/A2)n laminate where A1 is one of Co, CoFe, or an alloy thereof, and A2 is one of Pt, Pd, Rh, Ru, Ir, Mg, Mo, Os, Si, V, Ni, NiCo, and NiFe, or A1 is Fe and A2 is V. A method is also provided for forming the synthetic antiferromagnetic structure.