Patent Description:
Because of their potential for use in a variety of applications, research in magnetic memories is ongoing. Accordingly, what is needed is a method and system that may improve the performance of magnetic junctions.

<CIT> describes a magnetic junction usable in a magnetic device and a method for providing the magnetic junction. The magnetic junction includes a free layer, a pinned layer and nonmagnetic spacer layer between the free and pinned layers. At least one of the free and pinned layers includes at least one engineered Heusler structure having a first magnetic layer, a second magnetic layer and an amorphous layer between the magnetic layers. At least one of the first and second magnetic layer(s) is a Heusler layer. The first magnetic layer's perpendicular magnetic anisotropy energy (PMAE) exceeds is out-of-plane demagnetization energy. The second magnetic layer's PMAE exceeds its out-of-plane demagnetization energy. The free layer and/or the pinned layer has a PMAE greater than an out-of-plane demagnetization energy. The free layer is switchable between stable magnetic states when a write current is passed through the magnetic junction.

<CIT> discloses a spin transfer torque (STT) device, which is formed on an electrically conductive substrate and includes a ferromagnetic free layer near the substrate, a ferromagnetic polarizing layer and a nonmagnetic spacer layer between the free layer and the polarizing layer. A multilayer structure is located between the substrate and the free layer. The multilayer structure includes a metal or metal alloy seed layer for the free layer and an intermediate oxide layer below and in contact with the seed layer. The intermediate oxide layer reflects spin current from the free layer and thus reduces undesirable damping of the oscillation of the free layer's magnetization by the seed layer.

<CIT> describes devices that include a multi-layered structure that is non-magnetic at room temperature, and which comprises alternating layers of Co and at least one other element E (that is preferably Al; or Al alloyed with Ga, Ge, Sn or combinations thereof). The composition of this structure is represented by Co1-xEx, with x being in the range from <NUM> to <NUM>. The structure is in contact with a first magnetic layer that includes a Heusler compound. An MRAM element may be formed by overlying, in turn, the first magnetic layer with a tunnel barrier, and the tunnel barrier with a second magnetic layer (whose magnetic moment is switchable). Improved performance of the MRAM element may be obtained by placing an optional pinning layer between the first magnetic layer and the tunnel barrier.

Object of the invention is to provide an improved magnetic structure and a magnetic device including such a magnetic structure.

The object is attained by a magnetic structure according to claim <NUM> and a magnetic device according to claim <NUM>. Further developments are defined by the dependent claims.

The scope of the invention is limited only by the claims and the invention encompasses numerous alternatives and modifications within the definition of the claims.

The exemplary embodiments are described in the context of particular methods, layers, devices, magnetic junctions and magnetic memories having certain components. One of ordinary skill in the art will readily recognize that the present invention is consistent with the use of devices, magnetic junctions and magnetic memories having other and/or additional components and/or other features not inconsistent with the present invention. The method and system are also described in the context of current understanding of various physical phenomena. Consequently, one of ordinary skill in the art will readily recognize that theoretical explanations of the behavior of the method and system are made based upon this current understanding of these physical phenomena. However, the method and system described herein are not dependent upon a particular physical explanation. One of ordinary skill in the art will also readily recognize that the method and system are described in the context of a structure having a particular relationship to the substrate. However, one of ordinary skill in the art will readily recognize that the method and system are consistent with other structures. In addition, the method and system are described in the context of certain layers being synthetic and/or simple. However, one of ordinary skill in the art will readily recognize that the layers could have another structure. Furthermore, the method and system are described in the context of magnetic junctions and/or substructures having particular layers. However, one of ordinary skill in the art will readily recognize that magnetic junctions and/or substructures having additional and/or different layers not inconsistent with the method and system could also be used. Moreover, certain components are described as being magnetic, ferromagnetic, and ferrimagnetic. As used herein, the term magnetic could include ferromagnetic, ferrimagnetic and/or like structures. As used herein, "in-plane" is substantially within or parallel to the plane of one or more of the layers of a magnetic junction. Conversely, "perpendicular" and "perpendicular-to-plane" corresponds to a direction that is substantially perpendicular to one or more of the layers of the magnetic junction. The method and system are also described in the context of certain alloys. Unless otherwise specified, if specific concentrations of the alloy are not mentioned, any stoichiometry not inconsistent with the method and system may be used.

Magnetic tunneling junctions (MTJs) may be used in memories such as magnetic random access memories (MRAMs). MTJs may be programmable by a current driven in a current-perpendicular-to-plane (CPP) direction and used in a spin-transfer torque MRAM (STT-MRAM). Some MTJs utilize tunnel barriers formed from MgO as well as free and reference layers that include alloys of Co, Fe and B (termed "CoFeB" herein, without requiring a specific stoichiometry). The magnetic moments of the free and reference layers may be desired to be oriented perpendicular to the layer ("perpendicular-to-plane"). For magnetic layers having a perpendicular-to-plane magnetic moment, the perpendicular magnetic anisotropy (PMA) energy of the magnetic layer exceeds the out-of-plane demagnetization energy. However, the PMA of such a CoFeB layer arises from the interfaces between the CoFeB layer and the tunneling barrier layer and/or the underlayer on which the CoFeB layer is deposited. However, this means that such CoFeB layers may not be thermally stable if the device size is reduced to below approximately twenty nanometers in size. As such, Co-Fe-B layers may be unsuitable for use in more dense memory applications.

Magnetic materials that have a PMA arising from a volume effect and which may have a perpendicular-to-plane magnetic moment at small thicknesses include Heusler compounds. Heusler compounds may have the chemical formula X<NUM>YZ or X'X"YZ; where X, X', X", and Y may be transition metals or lanthanides (rare earth metals) and Z may be from a main group metal. Heusler compounds can have a structure of the type Cu<NUM>MnAl in which the elements are disposed on four interpenetrating face-centered cubic (fcc) lattices. Heusler compounds form a structure defined by the space group symmetry L2<NUM> (or D0<NUM> when they are tetragonally distorted). The properties of Heusler compounds are strongly dependent on the chemical ordering of the elements constituting the compounds. Many Heusler compounds are known to have a structure of the type Cu<NUM>MnAl. Some of these Heusler compounds are ferromagnetic or ferrimagnetic due to magnetic moments on the X and/or Y sites. Some parent Heusler compounds are cubic and exhibit weak or no significant magnetic anisotropy. However, the structure of some magnetic Heusler compounds is tetragonally distorted. Such a tetragonal Heusler compound has a crystal structure that is tetragonal instead of cubic. A tetragonal Heusler compound may also be magnetic. Due to the tetragonal distortion the magnetization exhibited by these compounds may be preferably aligned along the tetragonal axis. Thin films formed from such materials may exhibit PMA due to a magneto-crystalline anisotropy associated with their tetragonally distorted structure. For example, such tetragonal Heusler compounds include Mn<NUM>Z where Z = Ga, Ge, Sn, and Sb. Some such tetragonal Heusler compounds may be grown at smaller thicknesses and maintain their PMA. For example, with underlayers such as MnxN (where x is generally within range of <NUM> to <NUM>) and CoAl (usually nominally <NUM>:<NUM> composition ratio), some tetragonal Mn-containing Heusler compounds possessing PMA may be grown with smaller thicknesses. Similarly, magnetic L1<NUM> compounds containing Mn may be grown at smaller thicknesses. Such magnetic L1<NUM> compounds include MnSb alloys, MnAl alloys, MnSn alloys and MnGa alloys. Similarly tetragonal C38 phase of Mn containing compounds such as MnAlGe, MnGaGe, MnAlGa, MnGeIn, and MnGaSn, etc. which are ferromagnetic and low moment can also be used as free layer within MTJ device.

In addition to a large PMA, magnetic layers are also desired to have a low magnetic moment. A low magnetic moment allows for a lower switching current and a narrow switching pulse width (e.g. twenty nanoseconds and/or less). Heusler compounds may fulfill these criteria. For example, Heusler compounds grown on certain metallic underlayers, such as CoAl (e.g. B2 CoAl formed from alternating layers of Co and Al) may have a large PMA and a low magnetic moment. However, magnetic junctions employing such Heusler compounds may have a higher magnetic damping than desired. For example, in some cases, such Heusler compounds may have a magnetic damping on the order of that found in CoFeB. A high magnetic damping increases the switching current, which is undesirable. Consequently, a mechanism for decreasing the switching current of magnetic junctions while maintaining their PMA is desirable.

A magnetic structure, a magnetic device incorporating the magnetic structure and a method for providing the magnetic structure are described. The magnetic structure includes a magnetic layer, a templating structure and a resistive insertion layer. The magnetic layer includes a Heusler compound and has a perpendicular magnetic anisotropy energy exceeding an out-of-plane demagnetization energy. The templating structure has a crystal structure configured to template the resistive insertion layer and/or the Heusler compound. The magnetic layer is on the templating structure. The resistive insertion layer is configured to reduce magnetic damping for the Heusler compound and allow for templating of the Heusler compound.

In embodiments of the invention, the resistive insertion layer has a location selected from a first location, a second location, and a third location. The first location is between the templating structure and the magnetic layer. The second location is such that the templating structure is between the resistive insertion layer and the magnetic layer. The third location is on the magnetic layer such that the magnetic layer is between the templating structure and the resistive insertion layer.

For the resistive insertion layer being at the first location, the resistive insertion layer has a lattice mismatch of not more than ten percent for the Heusler compound. Thus, the resistive insertion layer at the first location is crystalline. For the resistive insertion layer having the first location, the resistive insertion layer may also have a (<NUM>) texture and a thickness of not more than <NUM> nanometers. In such embodiments, the Heusler compound may have a Heusler thickness of at least five nanometers. In such embodiments, the templating layer is configured to template at least the resistive insertion layer.

For the resistive insertion layer being at the second location, the resistive insertion layer has not more than ten percent lattice mismatch with the Heusler compound. Thus, the resistive insertion layer at the second location is crystalline. The templating structure has a thickness of not more than twenty Angstroms. In embodiments of the invention, the templating structure has a lattice mismatch with the Heusler compound of not more than ten percent and is configured to template the Heusler compound. In some embodiments, the templating structure has a thickness of at least one Angstrom and not more than twenty Angstroms. In some such embodiments, the templating structure has a thickness of not more than ten Angstroms. The thickness of the templating structure may be not more than five Angstroms. In some embodiments, the magnetic structure includes an additional templating structure. The resistive insertion layer is between the templating structure and the additional templating structure. The additional templating structure may be on and in physical contact with the MnxN-containing layer-seed layer.

For the resistive insertion layer having the third location, the magnetic structure may also include a tunneling barrier layer. The templating structure is on the tunneling barrier layer and the resistive insertion layer is further from a substrate than the magnetic layer. The templating structure is magnetic and may have the thickness of not more than twenty Angstroms. In some embodiments, the templating structure includes Coq(<NUM>-x)Alx, where x is less than <NUM>. In such embodiments, the templating structure is configured to template the Heusler compound. In some such embodiments, the thickness of the templating structure is not more than ten Angstroms. In some embodiments, a MnxN-containing layer (e.g. a seed layer) is included.

A magnetic device is also described. The magnetic device includes the magnetic structure as defined by claim <NUM>.

The resistive insertion layer has a location selected from a first location, a second location, and a third location analogous to the first, second and third locations for the magnetic structure. For the resistive insertion layer at the first location, the resistive insertion layer has a lattice mismatch of not more than ten percent for the Heusler compound. In such embodiments, the templating layer is configured to template at least the resistive insertion layer. In some such embodiments, the nonmagnetic spacer layer has a nonmagnetic spacer layer resistance, the resistive insertion layer has a (<NUM>) texture and a resistance of not more than twenty percent of the nonmagnetic spacer layer resistance. In some such embodiments, the resistive insertion layer has a resistance of not more than ten percent of the nonmagnetic spacer layer resistance. The Heusler compound may also have a Heusler thickness of at least five nanometers in such embodiments.

For the second location, the resistive insertion layer may have a lattice mismatch and the templating structure has a thickness of not more than twenty Angstroms. Thus, the resistive insertion layer is crystalline. In some such embodiments, the templating structure is at least one Angstrom and not more than ten Angstroms thick. In some embodiments, the thickness of the templating structure is not more than five Angstroms. The templating structure is also configured to template the Heusler compound. The magnetic device may also include an additional templating structure. The resistive insertion layer is between the templating structure and the additional templating structure. In such embodiments, the additional templating structure is thicker than the templating structure. The magnetic device may also include a seed layer on which the additional templating structure resides and shares an interface with. For example, the seed layer may include MnxN, where x is at least <NUM> and not more than <NUM>. In some such embodiments, x is at least <NUM> and not more than <NUM>.

For the third location, the resistive insertion layer is further from a substrate than the free layer. In some such embodiments, the nonmagnetic spacer layer is a tunneling barrier layer and the templating structure is on the tunneling barrier layer. In such embodiments, the templating structure may be magnetic and is configured to template the Heusler compound. The templating structure may have the thickness of not more than twenty Angstroms. In some embodiments, the templating structure includes Co(<NUM>-x)Alx, where x is less than <NUM> and the thickness is not more than ten Angstroms. The resistive insertion layer may be amorphous. For example, the amorphous resistive insertion layer may include one or more of amorphous Al-Oxide, Al-rich Mg-Al-Oxide, Ga-Oxide, Mg-Ga-Oxide, In-Zn-Oxide, and In-Ga-Zn-Oxide.

A method for providing a magnetic structure and/or magnetic device is also described. The method includes providing a templating structure having a crystal structure configured to template at least one of a resistive insertion layer and a Heusler compound. The method also includes providing, on the templating structure, a magnetic layer including the Heusler compound. The magnetic layer has a perpendicular magnetic anisotropy energy exceeding an out-of-plane demagnetization energy. A resistive insertion layer configured to reduce magnetic damping for the Heusler compound and allow for templating of the Heusler compound is also provided. In some examples, the method includes providing the resistive insertion layer at the first, second, and/or third location described above. For the resistive insertion layer being at the first location, the resistive insertion layer has a lattice mismatch of not more than ten percent for the Heusler compound. For the resistive insertion layer being at the second location, the resistive insertion layer may have a lattice mismatch and the templating structure has a thickness of not more than twenty Angstroms. For the resistive insertion layer being at the third location, the resistive insertion layer is further from a substrate than the magnetic layer.

<FIG> depicts embodiments of magnetic structures 100A, 100B, and 100C including Heusler compounds and having reduced magnetic damping. <FIG> are not to scale and additional layers (not shown) may be present in some embodiments. The magnetic structure 100A, 100B and/or 100C may be used in a variety of magnetic devices and, therefore, a variety of electronic devices. For example, the magnetic structure may be used in a magnetic junction such as a magnetic tunneling junction (MTJ) that may be included in a magnetic random access memory (MRAM).

Referring to <FIG>, magnetic structure 100A includes templating structure 110A, resistive insertion layer <NUM>, and magnetic layer <NUM>. Magnetic layer <NUM> includes a Heusler compound having a high perpendicular magnetic anisotropy (PMA). In some embodiments, magnetic layer <NUM> includes only Heusler compound(s). For example, magnetic layer <NUM> may be a layer consisting of a Heusler compound. In other embodiments, magnetic layer <NUM> may be a multilayer including one or more Heusler compounds and/or other materials. Magnetic layer <NUM>, and the Heusler compound(s) therein, each has a PMA energy that exceeds the out-of-plane demagnetization energy. Thus, magnetic moment <NUM> of magnetic layer <NUM> has stable states perpendicular to plane. One such stable state is shown in <FIG>. In some embodiments, magnetic layer <NUM> includes or consists of particular Mn-based Heusler compounds. For example, the Heusler compound(s) used may include or be composed of one or more of Mn<NUM>Ge, Mn<NUM>Al, Mn<NUM>Sb, Mn<NUM>Ga, Mn<NUM>Sn, Mn<NUM>In, and/or Mn<NUM>CoSn. Although these Heusler alloys are most likely to be stable in tetragonal phase (D0<NUM>), the formation of a distorted cubic phase having a high PMA is still possible if resistive insertion layer <NUM> has an in-plane lattice constant significantly larger than that of the magnetic layer <NUM>. This situation may occur for resistive insertion layer <NUM> including rock-salt oxide(s). In some embodiments, other high PMA Heusler compounds may be used. The Heusler compound, and thus magnetic layer <NUM>, are sufficiently thick that any issues due to the lattice mismatch with resistive insertion layer <NUM> may be resolved. For example, the Heusler compound of magnetic layer <NUM> may be at least five nanometers thick. In some embodiments, the Heusler compound of magnetic layer is at least one nanometer thick, but may be less than five nanometers thick. In some such embodiments, the Heusler compound is at least two nanometers thick. Other thicknesses may be possible.

Templating structure 110A is used to template resistive insertion layer <NUM>. Because resistive insertion layer <NUM> is used to template magnetic layer <NUM>, templating structure 110A may also be considered to template the Heusler compound of magnetic layer <NUM>. Thus, templating structure 110A is configured to have the appropriate structure (e.g. lattice constant, symmetry and/or texture) for growing or otherwise providing one or more layers on templating structure 110A. For example, templating structure <NUM> may have a (<NUM>) texture and a small lattice mismatch (e.g. not more than ten percent in some embodiments and not more than five percent in some such embodiments) with resistive insertion layer <NUM>. This allows resistive insertion layer <NUM> to be provided such that resistive insertion layer <NUM> can template the desired structure of the Heusler compound(s) of magnetic layer <NUM>. Templating structure 110A is a single layer in some embodiments. In other embodiments, templating structure 110A is a multilayer. Materials for templating structure 110A may include or consist of one or more of Ta, Ru, Fe, Ir, CoFeB, MgO, Ta-N, Ti-N, Mn-N, VN, Cu-N, Sc-N, CoSn, CoGe, NiAl, FeAl, CoAl (including B2 CoAl having alternating layers of Co and Al), RuAl, IrAl, Cr, and Cr-Ru. In some embodiments, templating structure 110A is at least five Angstroms and not more than six hundred Angstroms thick. In some embodiments, templating structure 110A is not more than three hundred Angstroms thick. In some such embodiments, templating structure 110A may be not more than ten Angstroms thick. In some embodiments, templating structure 110A may reside on and be in physical contact with (e.g. share an interface with) a seed layer (not shown) such as a MnxN seed layer (e.g. where x is at least <NUM> or <NUM> and not more than <NUM> or <NUM>). In some embodiments, such a seed layer may be at least five nanometers and not more than thirty nanometers thick.

Resistive insertion layer <NUM> is configured to reduce magnetic damping for the Heusler compound and allow for templating of the Heusler compound. Resistive insertion layer <NUM> may be a single layer in some embodiments. Other structures may be possible. Resistive insertion layer <NUM> is adjacent to magnetic layer <NUM>. In the embodiment shown, resistive insertion layer <NUM> shares an interface with magnetic layer <NUM>. Resistive insertion layer <NUM> may thus share an interface with the Heusler compound of magnetic layer <NUM>.

Thus, resistive insertion layer <NUM> is configured to have the appropriate structure (e.g. lattice constant, symmetry and/or texture) for growing or otherwise providing the Heusler compound(s) of magnetic layer <NUM> residing on resistive insertion layer <NUM>. Stated differently, resistive insertion layer <NUM> is configured to template the Heusler compound(s) of magnetic layer <NUM>. To template of the Heusler compound (e.g. provide the appropriate lattice constant, symmetry and/or orientation for growing the Heusler compound(s) having the desired structure), resistive insertion layer <NUM> may include one or more insulating and/or semiconducting compounds that have small in-plane lattice mismatch with the Heusler compound(s) of magnetic layer <NUM>. Thus, resistive insertion layer <NUM> is crystalline. In some embodiments, the lattice mismatch between the Heusler compound of magnetic layer <NUM> and resistive insertion layer is not more than ten percent (e.g. the in-plane lattice constant of resistive insertion layer <NUM> is within ten percent of the in-plane lattice constant for the Heusler compound of magnetic layer <NUM>). In some embodiments, the lattice mismatch between the Heusler compound of magnetic layer <NUM> and resistive insertion layer <NUM> is not more than eight percent. In some embodiments, the lattice mismatch between the Heusler compound of magnetic layer <NUM> and resistive insertion layer <NUM> is not more than five percent. Further, the symmetry of resistive insertion layer <NUM> sufficiently matches the desired symmetry of the Heusler compound(s) in magnetic layer <NUM>. The symmetry of resistive insertion layer <NUM> may be cubic for a Heusler compound having cubic symmetry. For example, resistive insertion layer <NUM> may be a cubic oxide, a cubic nitride, and/or a cubic semiconductor. Thus, the Heusler compound of magnetic layer <NUM> having a (<NUM>) orientation and the desired crystal structure may be provided on resistive insertion layer <NUM>. In some embodiments, resistive insertion layer <NUM> includes one or more of rock-salt oxides such as MgO, Mg-Al-Oxide, Mg-Ti-Oxide, Mg-Fe-Oxide, Mg-Zn-Oxide, and Mg-Mn-Oxide; spinel oxides such as MgAl<NUM>O<NUM>; perovskite oxides that may have the form ABO<NUM>, where A and B are cations of different sizes, such as CaTiO<NUM>, SrTiO<NUM>, BaTiO<NUM>, LaAlO<NUM>, BaSnO<NUM>; and halides such as NaCl and LiF; non-oxides (e.g. semiconductors) such as GaAs, ZnSe, and Cu(InxGa(<NUM>-x))Se<NUM>, and resistive nitrides such as AlN and ScN.

Although it is a resistive layer, the total resistance of resistive insertion layer <NUM> is desired to have a small effect on operation of a device employing magnetic structure 100A. Thus, the resistance of resistive insertion layer <NUM> is desired to be relatively small in comparison to other layer(s) of a device incorporating magnetic structure 100A. For example, in magnetic tunneling junctions (MTJs) in which magnetic structure 100A is incorporated, the resistance of resistive insertion layer <NUM> may be not more than twenty percent of the tunneling barrier resistance. In some such embodiments, the resistance of resistive insertion layer <NUM> is not more than ten percent of the tunneling barrier resistance. In some embodiments, the resistance of resistive insertion layer <NUM> may be not more than five percent of the tunneling barrier resistance. In some such embodiments, the resistance of resistive insertion layer <NUM> may be not more than two percent of the tunneling barrier resistance. The resistance area product of resistive insertion layer <NUM> is thus smaller than the resistance area product of the tunneling barrier layer. Consequently, the parasitic resistance due to resistive insertion layer <NUM> may be reduced. For similar reasons, resistive insertion layer <NUM> may be not more than <NUM> nanometers thick in some embodiments. In some embodiments, resistive insertion layer <NUM> is not more than <NUM> nanometer thick.

In the absence of resistive insertion layer <NUM>, magnetic layer <NUM> may have a high magnetic damping. For example, in spin transfer torque (STT) programming, a spin polarized current is driven through magnetic layer <NUM> to switch the state of magnetic moment <NUM>. Electrons in the spin polarized current transfer their angular momentum to magnetic layer <NUM>, causing magnetic moment <NUM> to switch directions to its other stable state (e.g. toward the bottom of the page in <FIG>). However, absent resistive insertion layer <NUM>, electrons from magnetic layer <NUM> may readily travel to templating structure 110A. These electrons share their (polarized) angular momentum with the nonmagnetic templating structure 110A. Magnetic damping occurs. As a result, the current required to switch magnetic moment <NUM> between stable states (e.g. the direction shown in <FIG> and one hundred and eighty degrees from this direction) using STT is greater than desired. Further, longer current pulses may be required in such a case.

The presence of resistive insertion layer <NUM> reduces magnetic damping. Resistive insertion layer <NUM> may reduce the movement of electrons between magnetic layer <NUM> and templating structure 110A. In the STT programming example above, a spin polarized current is still driven through magnetic layer <NUM>. Electrons in the spin polarized current still transfer their angular moment to magnetic layer <NUM>. However, the relatively higher resistance of resistive insertion layer <NUM> reduces or precludes the movement of electrons from magnetic layer <NUM> to templating structure 110A and/or other conductive structures. Thus, magnetic damping may be reduced. Magnetic layer <NUM> may be written using a smaller magnitude write current and/or a shorter current pulse width. Thus, performance of a device incorporating magnetic structure 100A may be improved.

Referring to <FIG>, magnetic structure 100B includes templating structure 110B, resistive insertion layer <NUM>, and magnetic layer <NUM>. Templating structure 110B, resistive insertion layer <NUM> and magnetic layer <NUM> of magnetic structure 100B are analogous to Templating structure 110A, resistive insertion layer <NUM> and magnetic layer <NUM>, respectively, of magnetic structure 100A depicted in <FIG>. However, templating structure 110B is between resistive insertion layer <NUM> and magnetic layer <NUM>. Thus, templating structure 110B is used to template magnetic layer <NUM>. In some embodiments, the composition and structure of templating structure 110B may differ from that of templating structure 110A.

Magnetic layer <NUM> of magnetic structure 100B depicted in <FIG> is analogous to magnetic layer <NUM> of magnetic structure 100A. Thus, magnetic layer <NUM> includes or consists of a Heusler compound having a high PMA and magnetic moment <NUM> that is stable perpendicular to plane. In some embodiments, magnetic layer <NUM> includes only Heusler compound(s). Because templating structure 110B may share an interface with magnetic layer <NUM>, and thus may share an interface with the Heusler compound contained therein, magnetic layer <NUM> may be better templated to the desired structure. Therefore, the Heusler compound(s) of magnetic layer <NUM> may be thinner. For example, the Heusler compound(s) (and thus magnetic layer <NUM>) may be less than five nanometers thick. In some embodiments, the Heusler compound(s) may be at least two nanometers thick and not more than five nanometers thick. In some embodiments, the Heusler compound(s) are not more than two nanometers thick and at least one nanometer thick in some embodiments. Other thicknesses may be possible.

Templating structure 110B is used to template the Heusler compound(s) of magnetic layer <NUM>. Templating structure 110B may, therefore, share an interface with magnetic layer <NUM> and the Heusler compound(s) therein. Further, templating structure 110B has a structure (e.g. lattice constant, symmetry, and/or orientation) that promote growth of the Heusler compound(s) for magnetic layer <NUM>. Templating structure 110B may have analogous structure, properties, and composition as for at least some embodiments of templating structure 110A. For example, templating layer 110B may include or be composed of any one or more of B2 binary alloys such as CoAl, CoGa, CoGe, CoSn, NiAl, FeAl, IrAl, RuAl, CuZn, and AgZn and/or other cubic-based ordered alloys (e.g. Ag-Mg) having a small (e.g. not more than ten percent and not more than five percent in some embodiments) in-plane lattice mismatch with the Heusler compound of magnetic layer <NUM>. In some embodiments, templating structure 110B has a small lattice mismatch with resistive insertion layer <NUM> on which templating structure 110B is situated. Templating structure 110B may be significantly thinner in magnetic structure 100B than templating structure 110A of magnetic structure 100A. In some embodiments, templating structure 110B of magnetic structure 100B is not more than twenty Angstroms thick. For example, templating structure 110B of magnetic structure 100B may be at least five Angstroms and not more than twenty Angstroms. In some such embodiments, templating structure 110B of magnetic structure 100B may be not more than ten Angstroms at least five Angstroms. Templating structure 110B of magnetic structure 100B may be not more than ten Angstroms at least one Angstrom. In some embodiments, templating structure 110B is at least one Angstrom and not more than five Angstroms.

Resistive insertion layer <NUM> is configured to reduce magnetic damping for the Heusler compound and allow for templating of the Heusler compound and templating structure 110B. Resistive insertion layer <NUM> of magnetic structure 100B is analogous to resistive insertion layer <NUM> of magnetic structure 100A. Thus, the structure and materials used for resistive insertion layer <NUM> of magnetic structure 100B are analogous to that of resistive insertion layer <NUM> of magnetic structure 100A. For example, resistive insertion layer <NUM> may include of MgO, Mg-Al-Oxide, Mg-Ti-Oxide, Mg-Fe-Oxide, Mg-Zn-Oxide, Mg-Mn-Oxide, MgAl<NUM>O<NUM>, CaTiO<NUM>, SrTiO<NUM>, BaTiO<NUM>, LaAlO<NUM>, BaSnO<NUM>, NaCl, LiF, GaAs, ZnSe, and/or Cu(InxGa<NUM>-x)Se<NUM>. The total resistance of resistive insertion layer <NUM> is desired to have a small effect on operation of a device employing magnetic structure 100B. Thus, the resistance and/or resistance-area product of resistive insertion layer <NUM> of magnetic structure 100B is analogous to that of resistive insertion layer <NUM> of magnetic structure 100A.

In some embodiments, resistive insertion layer <NUM> resides on an additional templating structure (not shown) that is analogous to templating structure 110B but may be thicker. In such cases, resistive insertion layer <NUM> may be viewed as being within a thicker templating structure. Such an additional templating layer may provide templating (e.g. (<NUM>) texture) for resistive insertion layer <NUM>. The additional templating layer may also provide templating for templating layer 110B and/or magnetic layer <NUM>. For example, such an additional templating layer may include Ta, Ru, Fe, Ir, CoFeB, MgO, Ta-N, Ti-N, Mn-N, VN, Cu-N, ScN, IrAl, CoGe, CoSn, NiAl, FeAl, CoAl, RuAl, Cr, and Cr-Ru. Magnetic layer <NUM> may, therefore, grow with a (<NUM>) orientation. An additional seed layer (not shown) may underlie and share an interface with the additional templating structure. For example, the seed layer (not shown) may be a MnxN seed layer (e.g. where x is at least <NUM> or <NUM> and not more than <NUM> or <NUM>).

The presence of resistive insertion layer <NUM> in magnetic structure 100B reduces magnetic damping. Resistive insertion layer <NUM> may reduce the movement of electrons between magnetic layer <NUM> and layers under resistive insertion layer <NUM>. Although electrons may still move between magnetic layer <NUM> and templating structure 110B of magnetic structure 100B, templating structure 110B is thin. Consequently, the amount of angular momentum imparted to templating structure 110B may be significantly reduced. Magnetic damping may thus be reduced. Consequently, magnetic layer <NUM> may be written using a smaller magnitude write current and/or a shorter current pulse width. Thus, performance of a device incorporating magnetic structure 100B may be improved.

<FIG> depicts magnetic structure 100C. Magnetic structure 100C includes templating structure 110C, resistive insertion layer <NUM>, and magnetic layer <NUM>. Templating structure 110C, resistive insertion layer <NUM> and magnetic layer <NUM> of magnetic structure 100C are analogous to those of magnetic structure(s) 100A and/or 100B. However, magnetic layer <NUM> is between templating structure 110C and resistive insertion layer <NUM>.

Magnetic layer <NUM> of magnetic structure 100C depicted in <FIG> is analogous to magnetic layer <NUM> of magnetic structure(s) 100A and/or 100B. Thus, magnetic layer <NUM> includes or consists of one or more Heusler compounds having a high PMA. Magnetic layer <NUM> also has magnetic moment <NUM> that is stable perpendicular to plane. Because templating structure 110C may share an interface with magnetic layer <NUM>, and thus may share an interface with the Heusler compound contained therein, magnetic layer <NUM> may be better templated to the desired structure. Therefore, the Heusler compound of magnetic layer <NUM> may be thinner. For example, the Heusler compound may be less than five nanometers thick. In some embodiments, the Heusler compound may be at least two nanometers thick. In some embodiments, the Heusler compound is not more than two nanometers thick. The Heusler compound is at least one nanometer thick in some embodiments. Other thicknesses may be possible.

Templating structure 110C is used to template the Heusler compound(s) of magnetic layer <NUM> and may share an interface with magnetic layer <NUM> and the Heusler compound(s) therein. However, in some embodiments, templating structure 110C might be omitted. When magnetic structure 100C is used in connection with a top free layer MTJ, magnetic layer <NUM> may be the free layer. In such embodiments, templating structure 110C resides on the tunneling barrier layer or other nonmagnetic spacer layer. In such embodiments, templating structure 110C may not only be thin, but also magnetic. In some embodiments, templating structure 110C is not more than twenty Angstroms thick. For example, templating structure 110C of magnetic structure 100C may be at least five Angstroms and not more than twenty Angstroms. In some such embodiments, the templating structure 110C of magnetic structure 100C may be not more than ten Angstroms. In some embodiments, templating structure 110C is at least one Angstrom and not more than five Angstroms. Templating structure 110C of magnetic structure 100C may be not more than ten Angstroms at least one Angstrom thick.

Templating structure 110C of magnetic structure 100C may also be magnetic. Use of a magnetic templating structure 110C may help preserve the magnetoresistance for the MTJ incorporating magnetic structure 100C. However, templating structure 110C is still desired to template the Heusler compound(s) of magnetic layer <NUM>. Thus, the crystal structure (e.g. in-plane lattice constant, symmetry and/or texture) of templating structure 110C is desired to be analogous to those described above, particularly templating structure 110B. For example, templating structure 110C may include or consist of Co(<NUM>-x)Alx, where x is less than <NUM>. Such an alloy is magnetic and may have the desired crystal structure for promoting growth of magnetic layer <NUM>.

Resistive insertion layer <NUM> of magnetic structure 100C is configured to reduce magnetic damping and is analogous to resistive insertion layer(s) <NUM> of magnetic structure(s) 100A and/or 100B. Thus, the structure and materials used for resistive insertion layer <NUM> of magnetic structure 100C are analogous to that of resistive insertion layer(s) <NUM> of magnetic structure(s) 100A and/or 100B. However, in some embodiments, resistive insertion layer <NUM> may be amorphous. This is because templating of magnetic layer <NUM> may be achieved by templating structure 110C. Thus, the materials used for resistive insertion layer <NUM> of magnetic structure 100C may also include any amorphous compounds that are semiconducting or insulating in nature. For example, Al-Oxide, Al-rich Mg-Al-Oxide, Ga-Oxide, Mg-Ga-Oxide, In-Zn-Oxide, and/or In-Ga-Zn-Oxide may be used. The total resistance of resistive insertion layer <NUM> is still desired to have a small effect on operation of a device employing magnetic structure 100C. Thus, the resistance and/or resistance-area product of resistive insertion layer <NUM> of magnetic structure 100C is analogous to that of resistive insertion layer(s) <NUM> of magnetic structure(s) 100A and/or 100B.

The presence of resistive insertion layer <NUM> in magnetic structure 100C reduces magnetic damping. Insertion layer <NUM> may reduce the movement of electrons between magnetic layer <NUM> and overlying layers. Magnetic damping may also be reduced. Consequently, magnetic layer <NUM> may be written using a smaller magnitude write current and/or a shorter current pulse width. Thus, performance of a device incorporating magnetic structure 100C may be improved.

As discussed above, magnetic structure(s) 100A, 100B and/or 100C may be incorporated in magnetic devices, such as magnetic junctions and magnetic memories using the magnetic junctions. Examples of such magnetic junctions are depicted in <FIG> and <FIG>.

<FIG> depict embodiments of magnetic devices 200A, 200B and 200C including Heusler compounds and having reduced magnetic damping. For clarity, <FIG> are not to scale. In the embodiments shown, magnetic devices 200A, 200B, and 200C are bottom free layer magnetic junctions. Thus, the free layer is closer to the substrate than the reference layer in such magnetic junctions. Magnetic devices 200A, 200B and/or 200C may be used in a variety of electronic devices, such as MRAMs. Although particular layers are shown, other and/or different structures may be included.

<FIG> depicts magnetic junction 200A residing on substrate <NUM>. Magnetic junction 200A includes templating structure 210A, resistive insertion layer <NUM>, free layer <NUM>, nonmagnetic spacer layer <NUM>, and reference layer <NUM>. Reference layer <NUM> and free layer <NUM> are magnetic, having magnetic moments <NUM> and <NUM>, respectively. In the embodiment shown, each of free layer <NUM> and reference layer <NUM> have a PMA anisotropy energy that exceeds the out-of-plane demagnetization energy. Consequently, magnetic moments <NUM> and <NUM> are shown as perpendicular to plane. Magnetic moment <NUM> of free layer <NUM> may be programmed to be in one of multiple stable states. Consequently, magnetic moment <NUM> is shown as dual headed arrow. Magnetic moment <NUM> of reference layer <NUM> is stable in the embodiment shown. Consequently, magnetic moment <NUM> is shown as a single arrow. Although shown in a particular direction (toward the bottom of the page), magnetic moment <NUM> may be stable in another direction (e.g. toward the top of the page). Magnetic junction 200A may also include optional polarization enhancement layer(s) (PEL(s)) having a high spin polarization. For example, a PEL might include Fe, CoFe and/or CoFeB. The PEL may be between reference layer <NUM> and nonmagnetic spacer layer <NUM> and/or between nonmagnetic spacer layer <NUM> and free layer <NUM>. Also shown are optional seed layer(s) <NUM> and optional capping layer(s) <NUM>. Capping layer <NUM> may include or be composed of any one or a combination of Ta, Ru, Mo, W, CoFeB, Pt, and metallic nitrides (e.g. Ta-N, Ti-N, Mo-N etc.). Seed layer <NUM> includes seed layer(s) used for providing templating structure 210A. For example, seed layer <NUM> may include a Ta layer on substrate <NUM>, a CoFeB layer on the Ta layer, and a seed layer such as MnxN (e.g. where <NUM> or <NUM> ≤ x ≤ <NUM> or <NUM>) used for templating structure 210A.

Nonmagnetic spacer layer <NUM> separates free layer <NUM> from reference layer <NUM>. In some embodiments, nonmagnetic spacer layer is a tunneling barrier layer, such as crystalline MgO. In some embodiments, nonmagnetic spacer layer <NUM> may be a conductive or other layer. A magnetoresistance depending upon the relative orientations of magnetic moments <NUM> and <NUM> is developed across nonmagnetic spacer layer <NUM>. For example, for magnetic junction 200A being an MTJ, a tunneling magnetoresistance across tunneling barrier layer <NUM> is high if magnetic moments <NUM> and <NUM> are antiparallel and low if magnetic moments <NUM> and <NUM> are parallel (this describes the case where both magnetic layers have positive spin polarization).

Reference layer magnetic moment <NUM> may be fixed by the magnetic properties of reference layer <NUM>. In the embodiment shown, for example, reference layer <NUM> has a stable magnetic moment <NUM> perpendicular-to-plane. In other embodiments, an optional pinning layer (not shown) may be used to fix the magnetization (not shown) of reference layer <NUM>. The optional pinning layer may be an AFM layer or multilayer that pins the magnetic moment <NUM> of reference layer <NUM> by an exchange-bias interaction. Although shown as a simple layer, reference layer <NUM> may be a synthetic layer. Reference layer <NUM> may thus contain or consist of a synthetic antiferromagnetic or synthetic ferrimagnetic structure. For example, reference layer <NUM> may include multiple magnetic layers separated by and antiferromagnetically coupled through nonmagnetic layer(s). For example, reference layer <NUM> may include two magnetic layers antiferromagnetically coupled through a nonmagnetic layer via the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction. Other multilayered structures can be used in or for reference layer <NUM>. For example, reference layer <NUM> may be or include a multilayered structure including or composed of a combination of ferromagnetic metals (e.g. CoFeB, Fe, Co, and/or CoFe), refractory metals (e.g. Ta, Mo, and/or W), exchange coupling metals (e.g. Ir, Ru, Rh, and/or Cr) and/or Co-based hard magnets (e.g. CoPt, Co/Pt, CoNi, Co/Ni, CoPd, Co/Pd). Reference layer <NUM> may contain synthetic antiferromagnetic or synthetic ferrimagnetic structure.

Reference layer <NUM> may also include one or more Heusler compounds. For example, reference layer <NUM> may be a multilayered structure including or composed of any one or more of perpendicularly magnetized Heusler alloys (e.g. Mn<NUM>Ge, Mn<NUM>Al, Mn<NUM>Sb, Mn<NUM>Ga, Mn<NUM>Sn, Mn<NUM>In, Mn<NUM>CoSn), L1<NUM> ordered alloys (e.g. FePt, FePd, MnAl, MnSb, MnGa, MnSn, MnGe), and exchange coupling metals (Ir, Ru, Rh, Cr, RuAl, IrAl). In such a case, Reference layer may use a seed layer. For example, the seed layer may include or consist of one of more of Ta, Ru, Fe, Ir, CoFeB, MgO, Ta-N, Ti-N, Mn-N, VN, Cu-N, ScN, IrAl, CoGe, CoSn, NiAl, FeAl, CoAl, RuAl, Cr, and Cr-Ru.

Free layer <NUM>, resistive insertion layer <NUM> and templating structure 210A are analogous to magnetic layer <NUM>, resistive insertion layer <NUM> and templating structure 110A, respectively, of magnetic structure 100A. Free layer <NUM> includes a Heusler compound having a high PMA. In some embodiments, free layer <NUM> includes only Heusler compound(s). Thus, the structure, composition, and properties of templating structure 210A, resistive insertion layer <NUM> and free layer <NUM> are analogous to those of templating structure 110A, resistive insertion layer <NUM>, and magnetic layer <NUM>, respectively.

Although it is a resistive layer, the total resistance of resistive insertion layer <NUM> is desired to have a small effect on operation of magnetic junction 200A. Thus, the resistance of resistive insertion layer <NUM> is desired to be relatively small in comparison to tunneling barrier layer <NUM>. For example, the resistance of resistive insertion layer <NUM> may be not more than ten percent of the tunneling barrier resistance. In some embodiments, the resistance of resistive insertion layer <NUM> may be not more than five percent of the resistance of tunneling barrier layer <NUM>. In some such embodiments, the resistance of resistive insertion layer <NUM> may be not more than two percent of the tunneling barrier resistance. The resistance area product of resistive insertion layer <NUM> is thus smaller than the resistance area product of tunneling barrier layer <NUM>. Consequently, the parasitic resistance due to resistive insertion layer <NUM> may be reduced.

The presence of resistive insertion layer <NUM> reduces magnetic damping for magnetic junction 200A. Insertion layer <NUM> may reduce the movement of electrons between free layer <NUM> and templating structure 210A. To program magnetic junction 200A using STT, a spin polarized current is driven through free layer <NUM>. For example, for a current driven from substrate <NUM> to capping layer <NUM>, electrons travel through reference layer <NUM> and become spin polarized in the direction of magnetic moment <NUM>. Electrons in the spin polarized current transfer their angular moment to free layer <NUM>. The relatively higher resistance of resistive insertion layer <NUM> reduced or precludes the movement of electrons from free layer <NUM> to templating structure 210A. Thus, magnetic damping may be reduced. Free layer <NUM> may be written using a smaller magnitude write current and/or a shorter current pulse width. Thus, performance of a magnetic junction 200A may be improved.

<FIG> depicts magnetic junction 200B residing on substrate <NUM>. Magnetic junction 200B includes resistive insertion layer <NUM>, free layer <NUM>, nonmagnetic spacer layer <NUM>, reference layer <NUM>, and capping layer <NUM> that are analogous to resistive insertion layer <NUM>, free layer <NUM>, nonmagnetic spacer layer <NUM> reference layer <NUM>, and capping layer <NUM> depicted in <FIG>, respectively. Further, resistive insertion layer <NUM>, templating structure 210B and free layer <NUM> are analogous to resistive insertion layer <NUM>, templating structure 110B and magnetic layer <NUM>, respectively, of magnetic structure 100B. For example, free layer <NUM> includes or is composed of Heusler compound(s) such as those in magnetic layer <NUM>. Similarly, templating structure 210B may be thin (e.g. not more than twenty Angstroms thick in some embodiments) and include any one or more of B2 binary alloys such as CoAl, CoGa, CoGe, CoSn, NiAl, FeAl, IrAl, RuAl, CuZn, and AgZn and/or other cubic-based ordered alloys (e.g. Ag-Mg) having a small (e.g. not more than ten percent and not more than five percent in some embodiments) in-plane lattice mismatch with the Heusler compound of free layer <NUM>. Resistive insertion layer <NUM> is configured to reduce magnetic damping for the Heusler compound and allow for templating of the Heusler compound and templating structure <NUM>. Further, the resistance of resistive insertion layer <NUM> is sufficiently low that the parasitic resistance due to resistive insertion layer <NUM> may not adversely affect operation of magnetic junction 200B. Optional seed layer <NUM> is used in templating insertion layer <NUM>. Optional seed layer <NUM> may include one or more of Ta, Ru, Fe, Ir, CoFeB, MgO, Ta-N, Ti-N, Mn-N, VN, Cu-N, Sc-N, CoSn, CoGe, NiAl, FeAl, CoAl, RuAl, IrAl, Cr, and Cr-Ru.

The presence of resistive insertion layer <NUM> reduces magnetic damping for magnetic junction 200B. Insertion layer <NUM> may reduce the movement of electrons from free layer <NUM> and templating structure 210B to seed layer <NUM> and other layers. Thus, magnetic damping may be reduced. Free layer <NUM> may be written using a smaller magnitude write current and/or a shorter current pulse width. Thus, performance of a magnetic junction 200B may be improved.

<FIG> depicts magnetic junction 200C residing on substrate <NUM>. Magnetic junction 200C includes resistive insertion layer <NUM>, free layer <NUM>, nonmagnetic spacer layer <NUM>, reference layer <NUM>, and capping layer <NUM> that are analogous to resistive insertion layer <NUM>, free layer <NUM>, nonmagnetic spacer layer <NUM> reference layer <NUM>, and capping layer <NUM> depicted in <FIG>, respectively. Free layer <NUM>, resistive insertion layer <NUM> and templating structure 210C are analogous to magnetic layer <NUM>, resistive insertion layer <NUM> and templating structure 100B. Resistive insertion layer <NUM>, templating structure 210C and free layer <NUM> are analogous to resistive insertion layer <NUM>, templating structure 210B and magnetic layer <NUM>.

Magnetic junction 200C also includes additional templating structure <NUM>. Additional templating structure <NUM> is analogous to templating structure 210C. Thus, additional templating structure <NUM> may include any one or more of B2 binary alloys such as CoAl, CoGa, CoGe, CoSn, NiAl, FeAl, IrAl, RuAl, CuZn, and AgZn and/or other cubic-based ordered alloys (e.g. Ag-Mg) having a small (e.g. not more than ten percent and not more than five percent in some embodiments) in-plane lattice mismatch with the Heusler compound of free layer <NUM>.

Resistive insertion layer <NUM> reduces magnetic damping for magnetic junction 200C. Insertion layer <NUM> may reduce the movement of electrons from free layer <NUM> and templating structure 210C to seed layer <NUM> and other layers. Thus, magnetic damping may be reduced. Free layer <NUM> may be written using a smaller magnitude write current and/or a shorter current pulse width. Thus, performance of a magnetic junction 200C may be improved.

<FIG> depict examples of magnetic devices 300A and 300B including Heusler compounds and having reduced magnetic damping. For clarity, <FIG> are not to scale. In the embodiments shown, magnetic devices 300A and 300B are top free layer magnetic junctions. Thus, the free layer is further from the substrate than the reference layer in such magnetic junctions. Magnetic devices 300A and/or 300B may be used in a variety of electronic devices, such as MRAMs. Although particular layers are shown, other and/or different structures may be included.

<FIG> depicts magnetic junction 300A residing on substrate <NUM>. Magnetic junction 300A includes resistive insertion layer <NUM>, free layer <NUM>, nonmagnetic spacer layer <NUM>, and reference layer <NUM>. Reference layer <NUM> and free layer <NUM> are magnetic, having magnetic moments <NUM> and <NUM>, respectively. In the embodiment shown, each of free layer <NUM> and reference layer <NUM> have a PMA anisotropy energy that exceeds the out-of-plane demagnetization energy. Consequently, magnetic moments <NUM> and <NUM> are shown as perpendicular to plane. Magnetic moment <NUM> of free layer <NUM> may be programmed to be in one of multiple stable states. Magnetic moment <NUM> is shown as dual headed arrow. Magnetic moment <NUM> of reference layer <NUM> is stable in the embodiment shown. Consequently, magnetic moment <NUM> is shown as a single arrow. Although shown in a particular direction (toward the top of the page), magnetic moment <NUM> may be stable in another direction (e.g. toward the bottom of the page). Magnetic junction 300A may also include optional polarization enhancement layer(s) (PEL(s)) having a high spin polarization. For example, a PEL might include Fe, CoFe and/or CoFeB. The PEL may be between reference layer <NUM> and nonmagnetic spacer layer <NUM> and/or between nonmagnetic spacer layer <NUM> and free layer <NUM>. Also shown are optional seed layer(s) <NUM> and optional capping layer(s) <NUM>. Optional capping layer <NUM> is analogous to optional capping layer <NUM>. Optional seed layer <NUM> is appropriate for forming reference layer <NUM>. For example, reference layer <NUM> may be a multilayered structure including or composed of a combination of ferromagnetic metals (e.g. CoFeB, Fe, Co, and/or CoFe), refractory metals (e.g. Ta, Mo, and/or W), exchange coupling metals (e.g. Ir, Ru, Rh, and/or Cr) and/or Co-based hard magnets (e.g. CoPt, Co/Pt, CoNi, Co/Ni, CoPd, Co/Pd). In some embodiments, reference layer <NUM> may contain synthetic antiferromagnetic or synthetic ferrimagnetic structure. In such a case, seed layer <NUM> may include or be composed of any one or more of a combination of Ta, Ru, Ir, Pt, CoFeB, and metallic nitrides (e.g. Ta-N, Ti-N, Mo-N, Cu-N and the like). In some such magnetic junctions, an additional nonmagnetic spacer layer and an additional reference layer may be interposed between free layer <NUM> and capping layer <NUM>. Thus, dual magnetic junctions may be formed.

Free layer <NUM> and resistive insertion layer <NUM> are analogous to magnetic layer <NUM> and resistive insertion layer <NUM> of magnetic structure 100C. However, a structure analogous to templating structure 110C has been omitted. Magnetic junction 300A thus has no templating structure for free layer <NUM> and is, therefore, outside the invention. The presence of resistive insertion layer <NUM> may reduce magnetic damping for magnetic junction 300A in a manner analogous to that described above.

Resistive insertion layer <NUM> may reduce the unwanted movement of electrons. To program magnetic junction 300A using STT, a spin polarized current is driven through free layer <NUM>. Electrons in the spin polarized current transfer their angular moment to free layer <NUM>. The relatively higher resistance of resistive insertion layer <NUM> reduced or precludes the movement of electrons from free layer <NUM>. Thus, magnetic damping may be reduced. Free layer <NUM> may be written using a smaller magnitude write current and/or a shorter current pulse width. Thus, performance of a magnetic junction 300A may be improved.

<FIG>, showing a device according to the invention, includes magnetic junction 300B that is analogous to magnetic junction 300A. Magnetic junction 300B includes resistive insertion layer <NUM>, free layer <NUM>, nonmagnetic spacer layer and reference layer <NUM> analogous to those used for magnetic junction 300A. However, magnetic junction 300B includes a templating structure 310B. Further, templating structure 310B may be magnetic. Free layer <NUM>, templating structure <NUM> and resistive insertion layer <NUM> are analogous to magnetic layer <NUM>, templating structure 110C and resistive insertion layer <NUM>. Thus, the structure, composition and performance of layers <NUM>, <NUM> and 310B are analogous to layers <NUM>, <NUM>, and 110C, respectively. For example, templating structure 310B may be thin, magnetic and include Co(<NUM>-x)Alx, where x is less than <NUM>.

The presence of resistive insertion layer <NUM> reduces magnetic damping for magnetic junction 300A. Insertion layer <NUM> may reduce the unwanted movement of electrons. Thus, magnetic damping may be reduced. Free layer <NUM> may be written using a smaller magnitude write current and/or a shorter current pulse width. Thus, performance of a magnetic junction 300B may be improved.

<FIG> is a flow chart depicting an embodiment of method <NUM> for fabricating magnetic structure which can be used for fabricating a magnetic structure according to the invention. For simplicity, some steps may be omitted, performed in another order, include substeps and/or combined. Although described in the context of single components, multiple components may be fabricated. For example, multiple magnetic structures may be fabricated. Further, the method <NUM> may start after other steps in forming a magnetic device including the magnetic structure have been performed. For simplicity, the method <NUM> is described in the context of the magnetic structures 100A, 100B and 100C. However, other magnetic structures may be formed.

A templating structure is provided, at <NUM>. For magnetic structures 100A and 100C, providing the templating structure is performed prior to formation of the magnetic and resistive insertion layers. For magnetic structure 100B, resistive insertion layer <NUM> is provided first. The templating structure formed at <NUM> is appropriate for the magnetic structure being fabricated. In some embodiments, <NUM> includes depositing or growing one or more layers of the templating structure. The layers may be deposited at a particular temperature range. For example, the templating structure may be deposited at a specific temperature or at a specific range of temperature. In some embodiments, the templating structure is provided within a range of temperatures including temperature(s) of not less than <NUM> and not more than <NUM>. Deposition methods may include but are not limited to PVD sputtering, pulse lased deposition, atomic layer deposition, ion-beam deposition, plasma enhanced chemical vapor deposition and/or other deposition mechanism(s). The fabrication of a layer may include annealing the layer. In-situ annealing (e.g. in vacuum or in any specific gas environment) may be performed right after deposition of any layer shown in each embodiment. Annealing may also occur later in fabrication (e.g. while the surface of the layer is exposed or after deposition of other layer(s)). The range of temperatures for in-situ annealing includes but may not be limited to at least <NUM> through not more than <NUM>.

A magnetic layer including one or more Heusler compounds is provided, at <NUM>. In some embodiments, such as when method <NUM> is used to form magnetic structure 100C, <NUM> is performed before formation of the resistive insertion layer. In other embodiments, such as for fabricating magnetic structure 100A or 100B, <NUM> is performed after <NUM> and formation of the resistive insertion layer. In some embodiments, <NUM> may be performed using the same techniques, temperature ranges and processes as described for <NUM>.

A resistive insertion layer is provided, at <NUM>. In some embodiments, such as for fabricating magnetic structure 100B, <NUM> is performed before formation of the templating structure and the magnetic layer including Heusler compound(s). In other embodiments, such as for fabricating magnetic structure 100A or 100C, <NUM> is performed later. If magnetic structure 100C is formed, <NUM> may include fabricating an amorphous resistive insertion layer. In some embodiments, <NUM> may be performed using the same techniques, temperature ranges and processes as described for <NUM>.

Thus, using method <NUM>, magnetic structures 100A, 100B, and/or 100C may be formed. Thus, the benefits described herein may be achieved. In particular, a high PMA (e.g. stable magnetic moment perpendicular to plane), high TMR may be achieved with reduced magnetic damping.

<FIG> is a flow chart depicting an embodiment of method <NUM> for fabricating magnetic device, such as magnetic junctions written using spin transfer torque and including a magnetic structure that can also be applied for fabricating a magnetic structure according to the invention. For simplicity, some steps may be omitted, performed in another order, include substeps and/or combined. Although described in the context of single components, multiple components may be fabricated. For example, multiple magnetic junctions may be formed. Further, the method <NUM> may start after other steps in forming a magnetic device have been performed.

A seed layer may optionally be provided, at <NUM>. In some embodiments, <NUM> provides the appropriate seed for the particular embodiment being fabricated. For example, in some embodiments, <NUM> includes providing a MnxN seed layer. <NUM> may also include fabricating an additional templating layer, such as templating structure <NUM> of magnetic device 200B.

A templating structure is provided, at <NUM>. In some embodiments, <NUM> is analogous to <NUM>. The layers may be deposited at a particular temperature range. For example, the templating structure may be deposited at a specific temperature or at a specific range of temperature. In some embodiments, the templating structure is provided within a range of temperatures including temperature(s) of not less than <NUM> and not more than <NUM>. Deposition methods may include but are not limited to PVD sputtering, pulse lased deposition, atomic layer deposition, ion-beam deposition, plasma enhanced chemical vapor deposition and/or other deposition mechanism(s). The fabrication of a layer may include annealing the layer. In-situ annealing (e.g. in vacuum or in any specific gas environment) may be performed right after deposition of any layer shown in each embodiment. Annealing may also occur later in fabrication (e.g. while the surface of the layer is exposed or after deposition of other layer(s)). The range of temperatures for in-situ annealing includes but may not be limited to at least <NUM> through not more than <NUM>.

A resistive insertion layer is provided, at <NUM>. In some embodiments, <NUM> is analogous to <NUM>. In some embodiments, such as for fabricating magnetic junction 200B, <NUM> is performed before formation of the templating structure and the magnetic layer including Heusler compound(s). In other embodiments, such as for fabricating magnetic junctions 200A or 300C, <NUM> is performed later. In some embodiments, <NUM> may be performed using the same techniques, temperature ranges and processes as described for <NUM>.

A free layer including one or more Heusler compounds is provided, at <NUM>. In some embodiments <NUM> is analogous to <NUM>. A nonmagnetic spacer layer, such as a tunneling barrier layer, and a reference layer are provided, at <NUM> and <NUM>, respectively.

Thus, using method <NUM>, magnetic devices 200A, 200B, 200C, 300A and/or 300B may be formed. Thus, the benefits described herein may be achieved. In particular, a high PMA (e.g. stable magnetic moment perpendicular to plane), high TMR may be achieved with reduced magnetic damping.

Claim 1:
A magnetic structure, comprising:
a magnetic layer (<NUM>; <NUM>; <NUM>) including a Heusler compound, the magnetic layer (<NUM>; <NUM>; <NUM>) having a perpendicular magnetic anisotropy energy exceeding an out-of-plane demagnetization energy;
further comprising
a resistive insertion layer (<NUM>; <NUM>; <NUM>) configured to reduce magnetic damping for the Heusler compound and allow for templating of the Heusler compound; and
a templating structure (110A; 110B; 110C; 210A; 210B; 210C; 310B) having a crystal structure configured to template at least one of the Heusler compound and the resistive insertion layer (<NUM>; <NUM>; <NUM>), the magnetic layer (<NUM>; <NUM>; <NUM>) residing on the templating structure (110A; 110B; 110C; 210A; 210B; 210C; 310B), characterised in that
wherein the resistive insertion layer (<NUM>; <NUM>; <NUM>) has a location selected from a first location, a second location, and a third location, the first location being between the templating structure (110A; 210A) and the magnetic layer (<NUM>; <NUM>), the second location being such that the templating structure (110B; 210B; 210C) is between the resistive insertion layer (<NUM>; <NUM>) and the magnetic layer (<NUM>; <NUM>); and the third location being on the magnetic layer (<NUM>) such that the magnetic layer (<NUM>) is between the templating structure (310B) and the resistive insertion layer (<NUM>);
wherein for the resistive insertion layer (<NUM>; <NUM>) being at the first location, the resistive insertion layer (<NUM>; <NUM>) has a lattice mismatch of not more than ten percent for the Heusler compound and is in direct contact with the templating structure (110A; 210A) and the magnetic layer (<NUM>; <NUM>);
wherein for the resistive insertion layer (<NUM>; <NUM>) being at the second location, the resistive insertion layer (<NUM>; <NUM>) has the lattice mismatch, and the templating structure (110B; 210B; 210C) has a thickness of not more than twenty Angstroms and is in direct contact with the resistive insertion layer (<NUM>; <NUM>) and the magnetic layer (<NUM>; <NUM>); and
wherein for the resistive insertion layer (<NUM>) being at the third location, the resistive insertion layer (<NUM>) is further from a substrate (<NUM>) than the magnetic layer (<NUM>), and the magnetic layer (<NUM>) is in direct contact with the templating structure (310B) and the resistive insertion layer (<NUM>).