Abstract: A scanning ferromagnetic resonance (FMR) measurement system is disclosed with a radio frequency (RF) probe and one or two magnetic poles mounted on a holder plate and enable a perpendicular-to-plane or in-plane magnetic field, respectively, at test locations. While the RF probe tip contacts a magnetic film on a whole wafer under test (WUT), a plurality of microwave frequencies (fR) is sequentially transmitted through the probe tip. Simultaneously, a magnetic field (HR) is applied to the contacted region thereby causing a FMR condition in the magnetic film for each pair of (HR, fR) values. RF output signals are transmitted through or reflected from the magnetic film to a RF diode and converted to voltage signals which a controller uses to determine effective anisotropy field, linewidth, damping coefficient, and/or inhomogeneous broadening for a sub-mm area. The WUT is moved to preprogrammed locations to enable multiple FMR measurements at each test location.

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 magnetic tunnel junction (MTJ) is disclosed wherein a free layer (FL) interfaces with a metal oxide (Mox) layer and a tunnel barrier layer to produce interfacial perpendicular magnetic anisotropy (PMA). The Mox layer has a non-stoichiometric oxidation state to minimize parasitic resistance, and comprises a dopant to fill vacant lattice sites thereby blocking oxygen diffusion through the Mox layer to preserve interfacial PMA and high thermal stability at process temperatures up to 400° C. Various methods of forming the doped Mox layer include deposition of the M layer in a reactive environment of O2 and dopant species in gas form, exposing a metal oxide layer to dopant species in gas form, and ion implanting the dopant. In another embodiment, where the dopant is N, a metal nitride layer is formed on a metal oxide layer, and then an anneal step drives nitrogen into vacant sites in the metal oxide lattice.

Abstract: A magnetic tunnel junction is disclosed wherein the reference layer and free layer each comprise one layer having a boron content from 25 to 50 atomic %, and an adjoining second layer with a boron content from 1 to 20 atomic %. One of the first and second layers in each of the free layer and reference layer contacts the tunnel barrier. Each boron containing layer has a thickness of 1 to 10 Angstroms and may include one or more B layers and one or more Co, Fe, CoFe, or CoFeB layers. As a result, migration of non-magnetic metals along crystalline boundaries to the tunnel barrier is prevented, and the MTJ has a low defect count of around 10 ppm while maintaining an acceptable TMR ratio following annealing to temperatures of about 400° C. The boron containing layers are selected from CoB, FeB, CoFeB and alloys thereof including CoFeNiB.

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 ferromagnetic resonance (FMR) measurement system is disclosed with a plurality of “m” RF probes and one or more magnetic assemblies to enable a perpendicular-to-plane or in-plane magnetic field (Hap) to be applied simultaneously with a sequence of microwave frequencies (fR) at a plurality of “m” test locations on a magnetic film formed on a whole wafer under test (WUT). A FMR condition occurs in the magnetic film (stack of unpatterned layers or patterned structure) for each pair of (Hap, fR) values. RF input signals are distributed to the RF probes using RF power distribution or routing devices. RF output signals are transmitted through or reflected from the magnetic film to a plurality of “n” RF diodes where 1?n?m, and converted to voltage signals which a controller uses to determine effective anisotropy field, linewidth, damping coefficient, and/or inhomogeneous broadening at the predetermined test locations.

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 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 method includes receiving tester configuration data, test pattern data, and tester operation data; configuring a circuit for performing a designated test evaluation; generating a stimulus waveform; converting the stimulus waveform to an analog stimulus signal; transferring the analog stimulus signal to a first terminal of a MTJ DUT at reception of a trigger timing signal; generating time traces based on the trigger timing signal; generating a response signal at a second terminal of the MTJ DUT and across a termination resistor as the analog stimulus signal is transferred through the MTJ DUT; converting the response signal to a digitized response signal indicating its voltage amplitude; and performing the designated test evaluation and analysis function in the configurable circuit based on voltage amplitudes and time values of the stimulus waveform, the digitized response signal, and the timing traces.

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 MgO layer is formed using a process flow wherein a Mg layer is deposited at a temperature <200° C. on a substrate, and then an anneal between 200° C. and 900° C., and preferably from 200° C. and 400° C., is performed so that a Mg vapor pressure >10?6 Torr is reached and a substantial portion of the Mg layer sublimes and leaves a Mg monolayer. After an oxidation between ?223° C. and 900° C., a MgO monolayer is produced where the Mg:O ratio is exactly 1:1 thereby avoiding underoxidized or overoxidized states associated with film defects. The process flow may be repeated one or more times to yield a desired thickness and resistance×area value when the MgO is a tunnel barrier or Hk enhancing layer. Moreover, a doping element (M) may be added during Mg deposition to modify the conductivity and band structure in the resulting MgMO layer.

Abstract: A ferromagnetic resonance (FMR) measurement system is disclosed with a waveguide transmission line (WGTL) connected at both ends to a mounting plate having an opening through which the WGTL is suspended. While the WGTL bottom surface contacts a portion of magnetic film on a whole wafer, a plurality of microwave frequencies is sequentially transmitted through the WGTL. Simultaneously, a magnetic field is applied to the contacted region thereby causing a FMR condition in the magnetic film. After RF output is transmitted through or reflected from the WGTL to a RF detector and converted to a voltage signal, effective anisotropy field, linewidth, damping coefficient, and/or inhomogeneous broadening are determined based on magnetic field intensity, microwave frequency and voltage output. A plurality of measurements is performed by controllably moving the WGTL or wafer and repeating the simultaneous application of microwave frequencies and magnetic field at additional preprogrammed locations on the magnetic film.

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 method includes receiving tester configuration data, test pattern data, and tester operation data; configuring a circuit for performing a designated test evaluation; generating a stimulus waveform; converting the stimulus waveform to an analog stimulus signal; transferring the analog stimulus signal to a first terminal of a MTJ DUT at reception of a trigger timing signal; generating time traces based on the trigger timing signal; generating a response signal at a second terminal of the MTJ DUT and across a termination resistor as the analog stimulus signal is transferred through the MTJ DUT; converting the response signal to a digitized response signal indicating its voltage amplitude; and performing the designated test evaluation and analysis function in the configurable circuit based on voltage amplitudes and time values of the stimulus waveform, the digitized response signal, and the timing traces.

Abstract: A first pattern is formed on an MTJ stack as a first array of first parallel bands. A first ion beam etching is performed on the MTJ stack using the first pattern wherein a tilt between an ion beam source and the substrate is maintained such that a horizontal component of the ion beam is parallel to the first parallel bands and the substrate is not rotated. Thereafter, a second pattern is formed on the MTJ stack as a second array of parallel bands wherein the second parallel bands are perpendicular to the first parallel bands. A second ion beam etching is performed using the second pattern wherein a tilt between an ion beam source and the substrate is maintained such that a horizontal component of the ion beam is parallel to the second parallel bands and wherein the substrate is not rotated to complete formation of the MTJ structure.

Abstract: A magnetic tunnel junction (MTJ) is disclosed wherein a nitride diffusion barrier (NDB) has a L2/L1/NL or NL/L1/L2 configuration wherein NL is a metal nitride or metal oxynitride layer, L2 blocks oxygen diffusion from an adjoining Hk enhancing layer, and L1 prevents nitrogen diffusion from NL to the free layer (FL) thereby enhancing magnetoresistive ratio and FL thermal stability, and minimizing resistance x area product for the MTJ. NL is the uppermost layer in a bottom spin valve configuration, or is formed on a seed layer in a top spin valve configuration such that L2 and L1 are always between NL and the FL or pinned layer, respectively. In other embodiments, one or both of L1 and L2 are partially oxidized. Moreover, either L2 or L1 may be omitted when the other of L1 and L2 is partially oxidized. A spacer between the FL and L2 is optional.

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.