JP6342113B2 - Method and system for providing a magnetic junction with improved characteristics - Google Patents

Description

Government Rights The present invention is based on Grant / Contract No. HR0011-09-C-0023 was made with the support of the US government. The US government has certain rights in the invention.

  Magnetic storage devices, in particular magnetic random access memory (MRAM), are of increasing interest due to their potential for fast read / write, excellent endurance, non-volatility, and low power consumption during operation. Collecting. The MRAM can store information using a magnetic material as an information recording medium. One type of MRAM is a spin transfer torque random access memory (STT-RAM). The STT-RAM utilizes a magnetic junction that is at least partially written by a current driven through the magnetic junction. A spin torque is applied to the magnetic moment in the magnetic junction by the spin polarization current driven through the magnetic junction. As a result, the layer having a magnetic moment that responds to the spin torque can be switched to a desired state.

  For example, FIG. 1 shows a conventional magnetic tunnel junction (MTJ) 10 that can be used in a conventional STT-RAM. This conventional MTJ 10 typically resides on the bottom contact 11 and uses a conventional seed layer 12, a conventional antiferromagnetic (AFM) layer 14, a conventional pinned layer 16, A conventional tunnel barrier layer 18, a conventional free layer 20 and a conventional capping layer 22 are included. Also shown in the figure is a top contact 24.

  Conventional contacts 11 and 24 are used to drive current in a current (CPP) direction perpendicular to the plane, that is, along the z-axis shown in FIG. A conventional seed layer 12 is typically utilized to assist in the growth of subsequent layers, such as the AFM layer 14, having the desired crystal structure. The conventional tunnel barrier layer 18 is nonmagnetic and is a thin insulator such as MgO.

  The conventional pinned layer 16 and the conventional free layer 20 are magnetic. The magnetization 17 of the conventional pinned layer 16 is usually fixed in a specific direction, that is, pinned by an exchange bias interaction with the AFM layer 14. Although shown as a simple (single) layer in the figure, the conventional pinned layer 16 may include multiple layers. For example, the conventional pinned layer 16 may be a synthetic antiferromagnetic (SAF) layer including a magnetic layer antiferromagnetically coupled through a thin conductive layer such as Ru. In such a SAF, a plurality of magnetic layers arranged alternately with thin layers of Ru can be used. In other embodiments, the coupling between the ends of the Ru layer may be ferromagnetic. Further, other versions of the conventional MTJ 10 may include an additional pinned layer (not shown) separated from the free layer 20 by an additional nonmagnetic barrier layer or conductive layer (not shown).

The conventional free layer 20 has a changeable magnetization 21. Although shown as a simple layer, the conventional free layer 20 may include multiple layers. For example, the conventional free layer 20 may be a synthetic layer including a magnetic layer antiferromagnetically or ferromagnetically coupled through a thin conductive layer such as Ru. Although shown as in-plane, the magnetization 21 of the conventional free layer 20 can have perpendicular anisotropy. Thus, the pinned layer 16 and the free layer 20 can have their magnetizations 17 and 21 oriented perpendicular to the plane of these layers, respectively.

  In order to switch the magnetization 21 of the conventional free layer 20, a current perpendicular to the plane (z direction) is driven. When sufficient current is driven from the top contact 24 to the bottom contact 11, the magnetization 21 of the conventional free layer 20 can be switched to be parallel to the magnetization 17 of the conventional pinned layer 16. When sufficient current is driven from the bottom contact 11 to the top contact 24, the magnetization 21 of the free layer can be switched to be antiparallel to the magnetization of the pinned layer 16. The differences in magnetic configuration correspond to different magnetoresistances, and thus correspond to different logic states (eg, logic “0” and logic “1”) of the conventional MTJ 10. Therefore, the state of the conventional MTJ can be determined by reading the tunneling magnetoresistance (TMR) of the conventional MTJ 10.

The conventional MTJ 10 can be written using spin transfer, can be read by perceiving the TMR of the junction, and can be used for STT-RAM, but there are drawbacks. For example, the signal from the conventional MTJ 10 may be smaller than the desired signal in some cases. In the case of a conventional MTJ 10 with perpendicularly oriented magnetizations 17 and 21, the TMR may in some cases be smaller than a conventional MTJ 10 with its magnetization in a plane. Therefore, in some cases, the signal from the conventional MTJ 10 may be smaller than the desired signal. In the case of a conventional MTJ 10 having magnetization oriented perpendicular to the plane, the vertical anisotropy of the conventional MTJ 10 may in some cases be less than the desired vertical anisotropy. Thus, a conventional MTJ 10 oriented at right angles may in some cases have lower thermal stability than desired. Also, the conventional MTJ 10 may exhibit attenuation greater than desired attenuation in some cases. Therefore, it is desirable that the performance of the memory using the conventional MTJ 10 is still improved.

  Therefore, there is a need for a method and system that can improve memory performance based on spin transfer torque. The methods and systems described herein address this need.

  A method and system for providing a magnetic junction that can be used in a magnetic device. The magnetic junction includes a pinned layer, a nonmagnetic spacer layer, a free layer, at least one insulating layer, and at least one magnetic insertion layer adjacent to the at least one insulating layer. The nonmagnetic spacer layer is located between the pinned layer and the free layer. At least one insulating layer is adjacent to at least one of the free layer and the pinned layer. The at least one magnetic insertion layer is adjacent to the at least one insulating layer. The magnetic junction is configured such that the free layer can be switched between a plurality of stable magnetic states when a write current flows through the magnetic junction.

It is a figure which shows the conventional magnetic joining. FIG. 3 illustrates an exemplary embodiment of a magnetic insertion layer adjacent to a MgO layer. FIG. 6 illustrates another exemplary embodiment of a magnetic insertion layer adjacent to a MgO layer. FIG. 3 illustrates an exemplary embodiment of a magnetic insertion layer adjacent to a MgO layer. FIG. 3 illustrates an exemplary embodiment of a magnetic junction that can be switched via spin transfer using a magnetic insertion layer. FIG. 6 illustrates another exemplary embodiment of a magnetic junction that can be switched via spin transfer using a magnetic insertion layer. FIG. 6 illustrates another exemplary embodiment of a magnetic junction that can be switched via spin transfer using a magnetic insertion layer. FIG. 6 illustrates another exemplary embodiment of a magnetic junction that can be switched via spin transfer using a magnetic insertion layer. FIG. 6 illustrates another exemplary embodiment of a magnetic junction that can be switched via spin transfer using a magnetic insertion layer. FIG. 6 illustrates another exemplary embodiment of a magnetic junction that can be switched via spin transfer using a magnetic insertion layer. FIG. 6 illustrates another exemplary embodiment of a magnetic junction that can be switched via spin transfer using a magnetic insertion layer. FIG. 6 illustrates another exemplary embodiment of a magnetic junction that can be switched via spin transfer using a magnetic insertion layer. FIG. 6 illustrates another exemplary embodiment of a magnetic junction that can be switched via spin transfer using a magnetic insertion layer. FIG. 6 illustrates another exemplary embodiment of a magnetic junction that can be switched via spin transfer using a magnetic insertion layer. FIG. 3 illustrates an exemplary embodiment of a method for manufacturing a magnetic junction including a magnetic substructure. FIG. 3 is a diagram illustrating an exemplary embodiment of a memory using magnetic junctions as storage elements of a storage cell.

  Exemplary embodiments relate to magnetic junctions that can be used in magnetic devices such as magnetic storage devices, and devices that use such magnetic junctions. The following description is provided to enable any person skilled in the art to make and use the invention and is provided in the context of a patent application and its requirements. Various modifications to the exemplary embodiments and general principles and features described herein will be readily apparent. These exemplary embodiments are primarily described with respect to particular methods and systems provided within particular implementations. However, these methods and systems are fully operational in other embodiments. Phrases such as “exemplary embodiment”, “one embodiment”, and “other embodiments” may represent the same or different embodiments, as well as multiple embodiments. These embodiments are described in terms of systems and / or devices having particular components. However, these systems and / or devices may include more or fewer components than those shown, and variations in the arrangement and types of these components without departing from the scope of the present invention. Can be added. These exemplary embodiments may also be described in the context of particular methods having particular steps. However, these methods and systems are fully operational for other methods having different steps and / or additional steps, and other methods having different order of steps consistent with these exemplary embodiments. Accordingly, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features described herein.

  A method and system for providing a magnetic junction and a magnetic storage device using the magnetic junction will be described. According to exemplary embodiments, methods and systems are provided for providing a magnetic junction that can be used in a magnetic device. The magnetic junction includes a pinned layer, a nonmagnetic spacer layer, a free layer, at least one MgO layer, and at least one magnetic insertion layer adjacent to the at least one MgO layer. The nonmagnetic spacer layer is located between the pinned layer and the free layer. The at least one MgO layer is adjacent to at least one of the free layer and the pinned layer. The at least one magnetic insertion layer is adjacent to the at least one MgO layer. The magnetic junction is configured such that the free layer can be switched between a plurality of stable magnetic states when a write current flows through the magnetic junction.

  Exemplary embodiments are described in the context of a particular magnetic junction and magnetic storage device having particular components. One skilled in the art will readily recognize that the present invention is consistent with the use of other components and / or additional components that are consistent with the present invention and / or magnetic junctions and magnetic storage devices having other features. These methods and systems are also described in the context of understanding currents in spin transfer phenomena, magnetic anisotropy and other physical phenomena. Thus, those skilled in the art will readily recognize that the theoretical explanation for the behavior of these methods and systems is based on this current understanding of spin transfer, magnetic anisotropy and other physical phenomena. However, these methods and systems described herein are not dependent on a specific physical description. Those skilled in the art will also readily recognize that these methods and systems are described in the context of a structure having a particular relationship to the substrate. However, those skilled in the art will readily recognize that these methods and systems are consistent with other structures. Moreover, these methods and systems are described in the context of a composite and / or simple specific layer. However, those skilled in the art will readily recognize that these layers may have other structures. Furthermore, these methods and systems are described in the context of magnetic junctions and / or substructures with particular layers. However, those skilled in the art will readily recognize that magnetic junctions and / or substructures having additional and / or different layers consistent with these methods and systems can also be used. Furthermore, certain components have been described as magnetic, ferromagnetic and ferrimagnetic. As used herein, the term magnetism can include ferromagnetic, ferrimagnetic or similar structures. Thus, as used herein, the term “magnetic” or “ferromagnetic” includes, but is not limited to, strong magnets and ferrimagnets. These methods and systems have also been described in the context of a single magnetic junction and substructure. However, those skilled in the art will readily recognize that these methods and systems are consistent with the use of magnetic storage devices having multiple magnetic junctions and using multiple substructures. Further, as used herein, “in plane” is substantially parallel to or in the plane of one or more of the layers of the magnetic junction. On the other hand, “right angle” corresponds to a direction substantially perpendicular to one or more of the layers of the magnetic junction.

  FIG. 2 illustrates one exemplary embodiment of a magnetic insertion layer 100 that can be used in a magnetic device, such as a magnetic tunnel junction (MTJ), spin valve or impact magnetoresistive structure, or some combination thereof. The magnetic device using the magnetic substructure 100 can be used for various applications. For example, the magnetic device, and thus the magnetic substructure, can be used in a magnetic storage device such as an STT-RAM. For clarity, FIG. 2 is not drawn to scale. The magnetic insertion layer 100 shown in the figure is adjacent to the MgO layer 120. In the embodiment shown in the figure, the MgO layer 120 is located on top of the magnetic insertion layer 100. However, in other embodiments, the magnetic insertion layer 100 can be grown on the MgO layer 120. Therefore, for the magnetic insertion layer 100 and the MgO layer 120, there is no specific relationship that must be assumed for the substrate. Furthermore, layer 120 is described as an MgO layer. However, in other embodiments, layer 120 can include at least one of aluminum oxide, tantalum oxide, ruthenium oxide, titanium oxide, and nickel oxide.

  The magnetic insertion layer 100 shown in FIG. 2 is at least one magnetic layer containing CoX, FeX and / or CoFeX, where X is a material containing B, Ge, Hf, Zr, Ti, Ta and Tb. Selected from the group. In some embodiments, the magnetic insertion layer 100 comprises CoX, FeX, and / or CoFeX. In some embodiments, the magnetic insertion layer 100 is formed of CoFeB. The magnetic insertion layer 100 is adjacent to the MgO layer 120. The MgO layer 120 may have a crystal structure and may have a preferable texture. In some embodiments, the magnetic insertion layer 100 is at least 3 angstroms and no greater than 2 nanometers. In some embodiments, the magnetic insertion layer 100 is made of a magnetic material but is preferably non-magnetic. In such embodiments, it may be desirable for the magnetic insertion layer 100 to be 5 nanometers or less, or a similar thickness, depending on the material used. The magnetic insertion layer 100 is magnetically dead when its thickness is so thin. Therefore, even if the magnetic insertion layer 100 is nonmagnetic, a magnetic material such as CoFeB can be used for the magnetic insertion layer. In other embodiments, thicker thicknesses can be used if the ferromagnetic insertion layer 100 is desirable or acceptable. When used for magnetic bonding, the magnetic insertion layer 100 exists outside the magnetoresistive region of the magnetic bonding. For example, in the case of MTJ, the magnetic insertion layer 100 does not exist between the free layer and the tunnel barrier layer or between the tunnel barrier layer and the pinned layer. Similarly, in the case of a double MTJ, the magnetic insertion layer 100 does not exist between the free layer and any of the two tunnel barrier layers, or the two pinned layers and the two tunnel barrier layers. There is no in between. Thus, the magnetic insertion layer 100 can be considered to be outside the sensory portion of the magnetic junction used with the magnetic insertion layer 100.

The magnetic insertion layer 100 can be used to adapt the characteristics of the magnetic junction in which the magnetic insertion layer 100 is used. For example, by combining the magnetic insertion layer 100 with the MgO layer 120 shown in FIG. 3, the MgO layer 120 having a smaller resistance area (RA) can be obtained. By using the magnetic insertion layer 100, other layers in the magnetic junction in which the magnetic insertion layer 100 is used can be affected. For example, the RA of a junction including a tunnel barrier layer (not shown in FIG. 2) between the pinned layer and the free layer can be reduced. In some embodiments, the RA of the combination of MgO layer 120, magnetic insertion layer 100 and junction (not shown) can be reduced by ½ or more. In some such embodiments, the junction RA can be reduced by 1/10 or more. This reduction in RA can improve the TMR of the magnetic junction. In some embodiments, the perpendicular anisotropy of other magnetic layers (not shown) in a magnetic junction using the magnetic insertion layer 100 can be improved. Therefore, spin transfer writing can be improved. It is also possible to make the magnetic junction thermally more stable using magnetization perpendicular to the plane. Therefore, the performance of the magnetic junction using the magnetic insertion layer 100 can be improved.

  Therefore, the characteristics of the magnetic device in which the magnetic insertion layer 100 is used can be configured as necessary. For example, the crystallization of the free layer is improved, and especially in the case of a tunnel junction with two barriers, the lattice matching with the tunnel junction is improved. Can be improved. Switching characteristics such as WER and data transfer rate can be improved in a magnetic device in which the magnetic substructure 100 is used.

  FIG. 3 illustrates one exemplary embodiment of a magnetic insertion layer 100 'that can be used in a magnetic device, such as an MTJ, spin valve, or impact magnetoresistive structure, or some combination thereof. The magnetic device in which the magnetic insertion layer 100 'is used can be used for various applications. For example, magnetic junctions, and thus magnetic insertion layers, can be used for magnetic storage devices such as STT-RAM. For clarity, FIG. 3 is not drawn to scale. This magnetic insertion layer 100 ′ is similar to the magnetic insertion layer 100. Similarly, the magnetic insertion layer 100 'shown in the figure includes an MgO layer 120'. Therefore, similar components are given similar labels. The magnetic insertion layer 100 'shown in the figure is adjacent to the MgO layer 120'. In the illustrated embodiment, the MgO layer 120 'is located on top of the magnetic insertion layer 100'. However, in other embodiments, the magnetic insertion layer 100 'can be grown on the MgO layer 120'. Therefore, for the magnetic insertion layer 100 'and the MgO layer 120', there is no specific relationship that must be assumed for the substrate. In the illustrated embodiment, layer 120 'is described as an MgO layer. However, in other embodiments, layer 120 'can include at least one of aluminum oxide, tantalum oxide, ruthenium oxide, titanium oxide, and nickel oxide.

  The magnetic insertion layer 100 ′ is used for magnetic bonding in the same manner as the magnetic insertion layer 100. Therefore, when used for magnetic bonding, the magnetic insertion layer 100 'exists outside the magnetoresistive region of the magnetic bonding. In other words, the magnetic insertion layer 100 'can be considered to be outside the sensory portion of the magnetic junction used with the magnetic insertion layer 100'.

  The magnetic insertion layer 100 ′ shown in FIG. 3 is a bimolecular layer including a magnetic layer 102 and an additional magnetic layer 104. The magnetic layer 102 includes CoX, FeX and / or CoFeX, where X is selected from a group of materials including B, Ge, Hf, Zr, Ti, Ta and Tb. In some embodiments, the magnetic layer 102 comprises CoX, FeX, and / or CoFeX. In some embodiments, the magnetic layer 102 is formed of CoFeB. Thus, the magnetic layer 102 can be considered similar to one embodiment of the magnetic insertion layer 100. The magnetic insertion layer 100 'is adjacent to the MgO layer 120'. In the illustrated embodiment, the magnetic layer 102 is adjacent to the MgO layer 120 ′ and located between the MgO layer 120 ′ and the additional magnetic layer 104. However, in other embodiments, the additional magnetic layer 104 can be present between the MgO layer 120 ′ and the magnetic layer 102. The additional magnetic layer 104 can include Co and / or Fe. In some embodiments, the magnetic layer 104 may comprise an Fe layer or a Co layer.

  In some embodiments, the magnetic insertion layer 100 'is at least 3 angstroms and no greater than 2 nanometers. In some embodiments, the magnetic insertion layer 100 'is made of a magnetic material but is preferably non-magnetic. In such an embodiment, the magnetic insertion layer 100 'may in some cases be 5 nanometers or less, or a similar thickness, relative to the material used. If the thickness of the magnetic insertion layer 100 ′ is so thin, it is magnetically dead. Thus, even if the magnetic insertion layer 100 ′ is non-magnetic, a magnetic material such as CoFeB can be used for the magnetic layer 102 and a magnetic material such as Co or Fe is used for the additional magnetic layer 104. can do. In other embodiments, thicker thicknesses can be used if the magnetic insertion layer 100 'is desirable or acceptable.

The magnetic insertion layer 100 ′ can be used to adapt the properties of the magnetic junction in which the magnetic insertion layer 100 ′ is used. Therefore, the magnetic insertion layer 100 ′ can share the advantages of the magnetic insertion layer 100. For example, a magnetic junction in which the magnetic insertion layer 100 ′ is used can enjoy small RA, improved TMR, greater perpendicular anisotropy, higher thermal stability, and / or other advantages. Therefore, it is possible to improve the performance of the magnetic junction using the magnetic insertion layer 100 ′.

  FIG. 4 illustrates an exemplary embodiment of a magnetic insertion layer 100 ″ that can be used in a magnetic device, such as an MTJ, spin valve, or impact magnetoresistive structure, or some combination thereof. The magnetic device in which 100 ″ is used can be used for various applications. For example, magnetic junctions, and thus magnetic insertion layers, can be used for magnetic storage devices such as STT-RAM. For clarity, FIG. 4 is not drawn to scale. This magnetic insertion layer 100 "is similar to the magnetic insertion layers 100 and 100 '. Similarly, the magnetic insertion layer 100" shown in the figure comprises an MgO layer 120 ". Similar labels are applied. The magnetic insertion layer 100 "shown in the figure is adjacent to the MgO layer 120". In the embodiment shown in the figure, the MgO layer 120 "is the magnetic insertion layer 100. However, in other embodiments, it is possible to grow a magnetic insertion layer 100 "on the MgO layer 120". Thus, with respect to the magnetic insertion layer 100 "and the MgO layer 120" There is no specific relationship that must be assumed for the substrate. In the illustrated embodiment, layer 120 "is described as an MgO layer. However, in other embodiments, layer 120 "can include at least one of aluminum oxide, tantalum oxide, ruthenium oxide, titanium oxide, and nickel oxide.

  The magnetic insertion layer 100 "is used in a magnetic junction in a manner similar to the magnetic insertion layers 100 and 100 '. Therefore, when used in a magnetic junction, the magnetic insertion layer 100" is a magnetoresistive region of the magnetic junction. Exists outside. In other words, the magnetic insertion layer 100 "can be considered to be outside the sensory part of the magnetic junction used with the magnetic insertion layer 100".

  The magnetic insertion layer 100 ″ shown in FIG. 4 is a multilayer that includes at least a first magnetic layer 102 ′, a nonmagnetic layer 106, and a second magnetic layer 108. In some embodiments, additional magnetic layers Layers (not shown) can be interleaved with additional non-magnetic layers (not shown) The first magnetic layer 102 'comprises CoX, FeX and / or CoFeX, where X is B, Ge , Hf, Zr, Ti, Ta and Tb.In some embodiments, the first magnetic layer 102 'is made of CoX, FeX and / or CoFeX. In this embodiment, the first magnetic layer 102 ′ is formed of CoFeB, and the second magnetic layer 108 includes CoY, FeY and / or CoFeY, where Y is B, Ge, Hf, Zr. , T In some embodiments, the second magnetic layer 108 is comprised of CoY, FeY and / or CoFeY.In some embodiments, the second magnetic layer 108 is selected from the group of materials including Ta, Tb. The first magnetic layer 102 'and the second magnetic layer 108 can each be considered similar to one embodiment of the magnetic insertion layer 100. The magnetic layer 108 is made of CoFeB. Layer 100 "is adjacent to MgO layer 120". In the illustrated embodiment, magnetic layer 102 'is adjacent to MgO layer 120 "and MgO layer 120" is coupled to the second magnetic layer. Located between the layers 108. However, in other embodiments, the second magnetic layer 108 may be present between the MgO layer 120 "and the magnetic layer 102 '. The nonmagnetic layer 106 shown in the figure is made of Ta. However, in other embodiments, other non-magnetic materials or additional non-magnetic materials can be used. For example, the nonmagnetic layer can include one or more of Ru, Cr, Ti, W, Ru, V, Hf, Zr, and Ta. In some embodiments, the nonmagnetic layer 106 may comprise at least one of Ru, Cr, Ti, W, Ru, V, Hf, Zr, and Ta.

  In some embodiments, the magnetic insertion layer 100 "is at least 3 angstroms and less than or equal to 2 nanometers. In some embodiments, the magnetic insertion layer 100" is made of a magnetic material but is non-magnetic. It is desirable to be magnetic. In such embodiments, each of the magnetic layers 102 'and 108 in the magnetic insertion layer 100 "may in some cases be 5 nanometers or less, or similar thickness, relative to the material used. These magnetic layers 102 'and 108 are each magnetically dead when their thickness is so thin. Therefore, even if the magnetic insertion layer 100 "is non-magnetic, magnetic materials such as CoFeB can be used. Can be used for the magnetic layers 102 ′ and 108. In other embodiments, thicker thicknesses can be used for either or both of these magnetic layers 102 'and 108 if a magnetic insertion layer 100' is desirable or acceptable. .

The magnetic insertion layer 100 "can be used to adapt the properties of the magnetic junction in which this magnetic insertion layer 100" is used. Thus, the magnetic insertion layer 100 "can share the advantages of the magnetic insertion layer 100 and / or 100 '. For example, the magnetic junction in which the magnetic insertion layer 100" is used has a smaller RA, improved TMR, and more. Greater vertical anisotropy, higher thermal stability and / or other benefits can be enjoyed. Therefore, the performance of the magnetic junction using the magnetic insertion layer 100 ″ can be improved.

  FIG. 5 illustrates one exemplary embodiment of a magnetic junction 200 that includes a magnetic insertion layer such as 100, 100 ′, and / or 100 ″. For clarity, FIG. 5 is not to scale. The magnetic junction 200 includes a MgO seed layer 204, a free layer 210, a nonmagnetic spacer layer 220, and a pinned layer 230. Although the orientation of layers 210, 220 and 230 is shown in the figure. This orientation can be changed in other embodiments, for example, the pinned layer 230 can be positioned closer to the bottom of the magnetic junction 200 (positioned closest to the substrate not shown in the figure). Also shown in the figure is an optional seed layer 202. A pinning layer (not shown) and a capping layer (not shown). In general, the pinning layer is used when the magnetic moment of the pinned layer 230 is in a plane, and the pinning layer is used when the magnetic moment of the pinned layer 230 is perpendicular to the plane. Such a pinning layer can be used to pin the magnetization (not shown) of the pinned layer 230. In some embodiments, the pinning layer is coupled to the pinned layer 230 by exchange bias interaction. It may be an AFM layer or multilayer that pins the magnetization (not shown), and this magnetic junction 200 may be in a plurality of stable magnetic states when a write current flows through it. Thus, the free layer 210 can be switched by using the spin transfer torque. Ri can be varied.

  The nonmagnetic spacer layer 220 may be a tunnel barrier layer, a conductor or other structure whose magnetoresistance is between the free layer 210 and the pinned layer 230. In some embodiments, the nonmagnetic spacer layer 220 is a crystalline MgO tunnel barrier layer. In such embodiments, the MgO seed layer 204 can be used to improve the TMR and other properties of the magnetic junction 200. It is assumed that the crystal structure of the tunnel barrier layer 220 is improved by the presence of the MgO seed layer.

Although shown as a simple layer in the figure, the free layer 210 and / or the pinned layer 230 can include multiple layers. For example, the free layer 210 and / or the pinned layer 230 may be a SAF including a magnetic layer that is antiferromagnetically or ferromagnetically coupled through a thin layer such as Ru. Such SAFs can use multiple magnetic layers interleaved with thin layers of Ru or other materials. Further, the free layer 210 and / or the pinned layer 230 may be another multilayer. Although the magnetization is not shown in FIG. 5, the free layer 210 and / or the pinned layer 230 can each have a perpendicular anisotropy energy that exceeds the out-of-plane demagnetization energy. Thus, the free layer 210 and / or the pinned layer 230 can each have its magnetic moment oriented perpendicular to the plane. In other embodiments, the magnetic moments of the free layer 210 and / or the pinned layer 230 are each in a plane. Other orientations of the magnetic moment of the free layer 210 and / or pinned layer 230 are possible.

Because the magnetic insertion layer 100, 100 ′ and / or 100 ″ is used, the magnetic junction 200 can share the advantages of the magnetic insertion layer 100, 100 ′ and / or 100 ″. Specifically, when the moments are oriented at right angles, the magnetic junction 200 can be thermally more stable, and the magnetic junction 200 has greater perpendicular anisotropy to the layers 210 and / or 230. Can reduce RA, and / or have improved TMR. As explained above, the magnetic insertion layer 100, 100 ′ and / or 100 ″ can reduce the RA of an adjacent MgO layer such as the MgO seed layer 204. The MgO seed layer relative to the total resistance of the magnetic junction 200. The contribution of the parasitic resistance of 204 can be reduced, so that the TMR due to the magnetic orientation of the free layer 210 and pinned layer 230 can be a larger portion of the total resistance of the magnetic junction 200. The TMR is effectively improved. Furthermore, the presence of the improved MgO seed layer 204, and hence the presence of the magnetic insertion layer 100/100 ′ / 100 ″, can reduce the RA of the MgO tunnel barrier layer 220. Therefore, the RA of the magnetic junction 200 can be further reduced. Therefore, the performance of the magnetic junction 200 can be improved.

  6 illustrates one exemplary embodiment of a magnetic junction 200 ′ that includes a magnetic insertion layer 100/100 ′ / 100 ″. For clarity, FIG. 6 is drawn to scale. This magnetic junction 200 'is similar to the magnetic junction 200. Therefore, similar layers are labeled with similar labels, which are free layers similar to layers 210, 220 and 230, respectively. 210 ', a non-magnetic spacer layer 220' and a pinned layer 230 ', although the figure shows layers 210', 220 'and 230' with a particular orientation, this orientation is altered in other embodiments. Also shown in the figure are the MgO seed layer 204 and the magnetic insertion layer 100/100 ′ / 100 ″. In some embodiments, an optional pinning layer (not shown) and / or an optional capping layer (not shown) can be included. The magnetic junction 200 'is also configured so that the free layer 210' can be switched between a plurality of stable magnetic states when a write current flows through the magnetic junction 200 '. Therefore, the free layer 210 'can be switched using the spin transfer torque.

  The nonmagnetic spacer layer 220 'may be a tunnel barrier layer, a conductor or other structure whose magnetoresistance is between the free layer 210' and the pinned layer 230 '. In some embodiments, the nonmagnetic spacer layer 220 'is a crystalline MgO tunnel barrier layer. In such embodiments, the MgO seed layer 204 'can be used to improve the TMR and other characteristics of the magnetic junction 200'. It is assumed that the presence of the MgO seed layer 204 'improves the crystal structure (structure and / or texture) of the tunnel barrier layer 220'.

Although shown as a simple layer in the figure, the free layer 210 'can include multiple layers as described above. The pinned layer 230 ′ is clearly shown to include a reference layer 232, a nonmagnetic layer 234 and a pinned layer 236. Accordingly, the pinned layer 230 ′ is SAF in this embodiment. Although the magnetization is not shown in FIG. 6, the free layer 210 ′ and / or the pinned layer 230 ′ can each have a perpendicular anisotropy energy that exceeds the out-of-plane demagnetization energy. Thus, the free layer 210 ′ and / or the pinned layer 230 ′ can each have its magnetic moment oriented perpendicular to the plane. In other embodiments, the magnetic moments of the free layer 210 ′ and / or the pinned layer 230 ′ are each in a plane. Other orientations of the magnetic moment of the free layer 210 'and / or pinned layer 230' are possible.

Since the magnetic insertion layer 100, 100 ′ and / or 100 ″ is used, the magnetic junction 200 ′ can share the advantages of the magnetic insertion layer 100, 100 ′ and / or 100 ″. In particular, when the moments are oriented at right angles, the magnetic junction 200 'can be thermally more stable and the magnetic junction 200' can be more perpendicular to the layers 210 'and / or 230'. Can have a low RA and / or have an improved TMR. Therefore, the performance of the magnetic junction 200 ′ can be improved.

  FIG. 7 illustrates an exemplary embodiment of a magnetic junction 200 "including a magnetic insertion layer 100, 100 '/ 100". For clarity, FIG. 7 is not drawn to scale. This magnetic junction 200 "is similar to the magnetic junction 200 and / or 200 '. Accordingly, similar layers are labeled with similar labels. The magnetic junction 200" has layers 210/210', 220, respectively. Includes a free layer 210 ", a non-magnetic spacer layer 220" and a pinned layer 230 "similar to / 220 'and 230/230'. The figures show layers 210", 220 "and 230" of specific orientation. However, this orientation can be changed in other embodiments. Also shown in the figure are the MgO seed layer 204 "and the magnetic insertion layer 100/100 '/ 100". In some embodiments, an optional pinning layer (not shown) and / or an optional capping layer (not shown) can be included. The magnetic junction 200 ″ is also configured to allow the free layer 210 ″ to be switched between a plurality of stable magnetic states when a write current flows through the magnetic junction 200 ″. Accordingly, the spin transfer torque. Can be used to switch the free layer 210 ".

  The non-magnetic spacer layer 220 "may be a tunnel barrier layer, conductor or other structure whose magnetoresistance is between the free layer 210" and the pinned layer 230 ". In some embodiments, the non-magnetic spacer layer 220" Layer 220 "is a crystalline MgO tunnel barrier layer. In such embodiments, the MgO seed layer 204 "can be used to improve the TMR and other properties of the magnetic junction 200". It is assumed that the presence of the MgO seed layer 204 "improves the crystal structure (structure and / or texture) of the tunnel barrier layer 220".

Although shown as a simple layer in the figure, the free layer 210 "and / or the pinned layer 230" may include multiple layers as described above. Although the magnetization is not shown in FIG. 7, the free layer 210 "and / or the pinned layer 230" can each have a perpendicular anisotropy energy that exceeds the out-of-plane demagnetization energy. Thus, each of the free layer 210 "and / or pinned layer 230" can have its magnetic moment oriented perpendicular to the plane. In other embodiments, the magnetic moments of free layer 210 "and / or pinned layer 230" are each in a plane. Other orientations of the magnetic moment of the free layer 210 "and / or pinned layer 230" are possible.

Since the magnetic insertion layer 100, 100 ′ and / or 100 ″ is used, the magnetic junction 200 ″ can share the advantages of the magnetic insertion layer 100, 100 ′ and / or 100 ″. When the moments are oriented at right angles, the magnetic junction 200 "can be thermally more stable and the magnetic junction 200" has a greater perpendicular anisotropy to the layers 210 "and / or 230". Can reduce RA, and / or have improved TMR, thus improving the performance of the magnetic junction 200 ".

  FIG. 8 shows an exemplary embodiment of a magnetic junction 200 ′ ″ including a magnetic insertion layer 100, 100 ′ / 100 ″. For clarity, FIG. 8 is drawn to scale. This magnetic junction 200 ′ ″ is similar to the magnetic junction 200, 200 ′ and / or 200 ″. Therefore, the same label is given to the same layer. The magnetic junction 200 ′ ″ includes a free layer 210 ′ ″ similar to the layers 210/210 ′ / 210 ″, 220/220 ′ / 220 ″ and 230/230 ′ / 230 ″, respectively, and a nonmagnetic spacer layer 220 ″. 'And pinned layer 230' ''. The figure shows specific orientation layers 210 '' ', 220' '' and 230 '' ', but this orientation may vary in other embodiments. Also shown in the figure are the MgO seed layer 204 ′ ″ and the magnetic insertion layer 100/100 ′ / 100 ″. In some embodiments, an optional pinning layer (not shown) and / or an optional capping layer (not shown) can be included. The magnetic junction 200 ′ ″ is also configured to allow the free layer 210 ′ ″ to switch between a plurality of stable magnetic states when a write current flows through the magnetic junction 200 ′ ″. Yes. Therefore, the free layer 210 ″ ″ can be switched using the spin transfer torque.

  The non-magnetic spacer layer 220 "" may be a tunnel barrier layer, a conductor or other structure whose magnetoresistance is between the free layer 210 "" and the pinned layer 230 "". In some embodiments, the non-magnetic spacer layer 220 '' 'is a crystalline MgO tunnel barrier layer. In such embodiments, the MgO seed layer 204 "" can be used to improve the TMR and other properties of the magnetic junction 200 "". It is assumed that the presence of the MgO seed layer 204 ″ ″ improves the crystal structure (structure and / or texture) of the tunnel barrier layer 220 ″ ″.

  Further, the magnetic junction 200 "" has a double structure. Accordingly, the magnetic junction 200 ″ ″ also includes an additional nonmagnetic spacer layer 240 and an additional pinned layer 250. The nonmagnetic spacer layer 240 may be similar to the nonmagnetic spacer layer 220 '' '. Therefore, the nonmagnetic spacer layer 240 may be a crystalline MgO tunnel barrier layer. In other embodiments, the non-magnetic spacer layer 240 may be different from the layer 220 '' '. Similarly, pinned layer 250 may be similar to pinned layer 230 ".

Although shown as simple layers in the figure, the free layer 210 '''and / or the pinned layers 230''' and 250 may include multiple layers as described above. Although the magnetization is not shown in FIG. 8, the free layer 210 ′ ″ and / or the pinned layers 230 ′ ″ and 250 can each have a perpendicular anisotropy energy that exceeds the out-of-plane demagnetization energy. . Thus, the free layer 210 ′ ″ and / or the pinned layers 230 ′ ″ and 250 can each have its magnetic moment oriented perpendicular to the plane. In other embodiments, the magnetic moments of the free layer 210 ′ ″ and / or the pinned layer 230 ′ ″ are each in a plane. Other orientations of the magnetic moment of the free layer 210 ′ ″ and / or the pinned layer 230 ′ ″ are possible.

Since the magnetic insertion layer 100, 100 ′ and / or 100 ″ is used, the magnetic junction 200 ′ ″ can share the advantages of the magnetic insertion layer 100, 100 ′ and / or 100 ″. In particular, when the moments are oriented at right angles, the magnetic junction 200 '''can be thermally more stable, and the magnetic junction 200''' can be made into layers 210 '''and / or 230'. Can have greater vertical anisotropy relative to '', RA can be reduced, and / or improved TMR. Therefore, the performance of the magnetic junction 200 ′ ″ can be improved.

  FIG. 9 illustrates an exemplary embodiment of a magnetic junction 300 that includes a magnetic insertion layer, such as 100, 100 ′, and / or 100 ″. For clarity, FIG. 9 is not to scale. Not shown, the magnetic junction 300 includes a free layer 310, a non-magnetic spacer layer 320, a pinned layer 330, and a MgO capping layer 304. Although the illustration shows layers 310, 320, and 330 in a particular orientation. This orientation can be changed in other embodiments, for example, the pinned layer 330 can be positioned closer to the bottom of the magnetic junction 300 (positioned closest to the substrate not shown in the figure). Also shown in the figure is an optional seed layer 302. A pinning layer (not shown) and an MgO seed layer (not shown) are used. Usually, the pinning layer is used when the magnetic moment of the pinned layer 330 is in a plane, and the pinning layer is not used when the magnetic moment of the pinned layer 330 is perpendicular to the plane. The pinning layer can be used to pin the magnetization (not shown) of the pinned layer 330. In some embodiments, the pinning layer can be magnetized (not shown) by the exchange bias interaction. The magnetic junction 300 also switches the free layer 310 between a plurality of stable magnetic states when a write current flows through the magnetic junction 300. Therefore, the free layer 310 can be switched using the spin transfer torque.

  The nonmagnetic spacer layer 320 may be a tunnel barrier layer, a conductor or other structure whose magnetoresistance is between the free layer 310 and the pinned layer 330. In some embodiments, the nonmagnetic spacer layer 320 is a crystalline MgO tunnel barrier layer. In such embodiments, the MgO capping layer 304 can be used to improve the TMR and other characteristics of the magnetic junction 300. Due to the presence of the MgO capping layer 304, the crystalline MgO tunnel barrier layer 320 is sensitive to the surrounding structures that can affect the deposition of the layer and the annealing of the magnetic junction 300, among other effects. It is assumed that the crystal structure (structure and / or texture) of the tunnel barrier layer 320 is improved.

Although shown as a simple layer in the figure, the free layer 310 and / or the pinned layer 330 can include multiple layers. For example, the free layer 310 and / or the pinned layer 330 may be a SAF including a magnetic layer that is antiferromagnetically or ferromagnetically coupled through a thin layer such as Ru. Such SAFs can use multiple magnetic layers interleaved with thin layers of Ru or other materials. Further, the free layer 310 and / or the pinned layer 330 may be another multilayer. Although the magnetization is not shown in FIG. 9, the free layer 310 and / or the pinned layer 330 can each have a perpendicular anisotropy energy that exceeds the out-of-plane demagnetization energy. Thus, the free layer 310 and / or the pinned layer 330 can each have its magnetic moment oriented perpendicular to the plane. In other embodiments, the magnetic moments of free layer 310 and / or pinned layer 330 are each in a plane. Other orientations of the magnetic moment of the free layer 310 and / or the pinned layer 330 are possible.

Since the magnetic insertion layer 100, 100 ′ and / or 100 ″ is used, the magnetic junction 300 can share the advantages of the magnetic insertion layer 100, 100 ′ and / or 100 ″. Specifically, when the moments are oriented at right angles, the magnetic junction 300 can be made more thermally stable and the magnetic junction 300 has a greater perpendicular anisotropy to the layers 310 and / or 330. Can reduce RA, and / or have improved TMR. As explained above, the magnetic insertion layer 100, 100 ′ and / or 100 ″ can reduce the RA of an adjacent MgO layer such as the MgO seed layer 304. The parasitic resistance of the MgO capping layer 304 is reduced. Therefore, the TMR of the magnetic junction 300 can be effectively improved. Furthermore, due to the presence of the improved MgO capping layer 304 and hence the magnetic insertion layer 100/100 ′ / 100 ″, the MgO tunnel barrier layer 320 can be improved. RA can be reduced. Therefore, the RA of the magnetic junction 300 can be further reduced. Therefore, the performance of the magnetic junction 300 can be improved.

  FIG. 10 illustrates an exemplary embodiment of a magnetic junction 300 ′ that includes a magnetic insertion layer 100/100 ′ / 100 ″. For clarity, FIG. 10 is drawn to scale. This magnetic junction 300 'is similar to the magnetic junction 300. Therefore, similar layers are labeled with similar labels, which are free layers similar to layers 310, 320 and 330, respectively. 310 ', a non-magnetic spacer layer 320' and a pinned layer 330 ', although the illustration shows layers 310', 320 'and 330' with a particular orientation, this orientation is altered in other embodiments. Also shown are MgO capping layer 304 'and magnetic insertion layer 100/100' / 100 ". In some embodiments, an optional pinning layer (not shown) and / or an optional MgO seed layer (not shown) can be included. The magnetic junction 300 'is also configured so that the free layer 310' can be switched between a plurality of stable magnetic states when a write current flows through the magnetic junction 300 '. Therefore, the free layer 310 ′ can be switched using the spin transfer torque.

  The nonmagnetic spacer layer 320 'may be a tunnel barrier layer, a conductor or other structure whose magnetoresistance is between the free layer 310' and the pinned layer 330 '. In some embodiments, the nonmagnetic spacer layer 320 'is a crystalline MgO tunnel barrier layer. In such embodiments, MgO capping layer 304 'can be used to improve TMR and other properties of magnetic junction 300'. The crystalline MgO tunnel barrier layer 320 ′ is sensitive to the surrounding structures that may affect the deposition of the layer and the annealing of the magnetic junction 300 ′, among others, so that the MgO capping layer 304 ′ is present. By doing so, it is assumed that the crystal structure (structure and / or texture) of the tunnel barrier layer 320 ′ is improved.

Although shown as simple layers in the figure, the free layer 310 ′ and / or pinned layer 330 ′ may include multiple layers as described above. Although magnetization is not shown in FIG. 10, the free layer 310 ′ and / or the pinned layer 330 ′ can each have a perpendicular anisotropy energy that exceeds the out-of-plane demagnetization energy. Thus, the free layer 310 ′ and / or the pinned layer 330 ′ can each have its magnetic moment oriented perpendicular to the plane. In other embodiments, the magnetic moments of the free layer 310 ′ and / or the pinned layer 330 ′ are each in a plane. Other orientations of the magnetic moment of the free layer 310 ′ and / or the pinned layer 330 ′ are possible.

Because the magnetic insertion layer 100, 100 ′ and / or 100 ″ is used, the magnetic junction 300 ′ can share the advantages of the magnetic insertion layer 100, 100 ′ and / or 100 ″. In particular, when the moments are oriented at right angles, the magnetic junction 300 ′ can be thermally more stable and the magnetic junction 300 ′ can be more perpendicular to the layers 310 ′ and / or 330 ′. Can have a low RA and / or have an improved TMR. Therefore, the performance of the magnetic junction 300 ′ can be improved.

  FIG. 11 illustrates an exemplary embodiment of a magnetic junction 300 ″ that includes a magnetic insertion layer 100/100 ′ / 100 ″. For clarity, FIG. 11 is not drawn to scale. This magnetic junction 300 "is similar to the magnetic junction 300 and / or 300 '. Accordingly, similar layers are labeled with similar labels. The magnetic junction 300" has layers 310/310', 320, respectively. Includes a free layer 310 ", a nonmagnetic spacer layer 320" and a pinned layer 330 "similar to / 320 'and 330/330'. The figure shows layers 310", 320 "and 330" of specific orientation. However, this orientation can be changed in other embodiments. Also shown are MgO capping layer 304 "and magnetic insertion layer 100/100 '/ 100". In some embodiments, an optional pinning layer (not shown) and / or an optional MgO seed layer (not shown) can be included. The magnetic junction 300 "is also configured so that the free layer 310" can be switched between a plurality of stable magnetic states when a write current flows through the magnetic junction 300 ". Can be used to switch the free layer 310 ".

  The non-magnetic spacer layer 320 "may be a tunnel barrier layer, conductor or other structure whose magnetoresistance is between the free layer 310" and the pinned layer 330 ". In some embodiments, the non-magnetic spacer layer Layer 320 "is a crystalline MgO tunnel barrier layer. As described above, in such embodiments, the MgO capping layer 304 "can be used to improve the TMR and other properties of the magnetic junction 300".

  Further, the magnetic junction 300 "has a double structure. Therefore, the magnetic junction 300" also includes an additional nonmagnetic spacer layer 340 and an additional pinned layer 350. The nonmagnetic spacer layer 340 may be similar to the nonmagnetic spacer layer 320 ″. Accordingly, the nonmagnetic spacer layer 340 may be a crystalline MgO tunnel barrier layer. In other embodiments, the nonmagnetic spacer layer 340 May be different from layer 320 ". Similarly, the pinned layer 350 may be similar to the pinned layer 330 ″.

Although shown as simple layers in the figure, free layer 310 "and / or pinned layers 330" and 350 can include multiple layers as described above. Although magnetization is not shown in FIG. 11, the free layer 310 ″ and / or the pinned layers 330 ″ and 350 can each have a perpendicular anisotropy energy that exceeds the out-of-plane demagnetization energy. Thus, the free layer 310 "and / or the pinned layers 330" and 350 can each have its magnetic moment oriented perpendicular to the plane. In other embodiments, the magnetic moments of the free layer 310 "and / or the pinned layer 330" are each in a plane. Other orientations of the magnetic moment of the free layer 310 "and / or the pinned layer 330" are possible.

Since the magnetic insertion layer 100, 100 ′ and / or 100 ″ is used, the magnetic junction 300 ″ can share the advantages of the magnetic insertion layer 100, 100 ′ and / or 100 ″. When the moments are oriented at right angles, the magnetic junction 300 "can be made more thermally stable and the magnetic junction 300" has a greater perpendicular anisotropy to the layers 310 "and / or 330". Can reduce RA, and / or have improved TMR, thus improving the performance of the magnetic junction 300 ".

  12 illustrates one exemplary embodiment of a magnetic junction 400 that includes two magnetic insertion layers, such as 100, 100 ′, and / or 100 ″. For clarity, FIG. 12 is to scale. The magnetic junction 400 includes a free layer 410, a non-magnetic spacer layer 420, a pinned layer 430 and a MgO seed layer 404 and a MgO capping layer 406. The layers 410, 420 and 420 in a particular orientation are shown in the figure. This orientation can be changed in other embodiments, for example, pinned layer 430 can be located closer to the bottom of magnetic junction 400 (shown in the figure). The figure also shows an optional seed layer 302. A pinning layer (not shown) is used. Usually, the pinning layer is used when the magnetic moment of the pinned layer 430 is in a plane, and the pinning layer is not used when the magnetic moment of the pinned layer 430 is perpendicular to the plane. Such a pinning layer can be used to pin the magnetization (not shown) of the pinned layer 430. In some embodiments, the pinning layer can be coupled to the magnetization (of the pinned layer 430 by exchange bias interaction). It may be an AFM layer or multi-layer that pins (not shown), and this magnetic junction 400 also includes a free layer 410 between a plurality of stable magnetic states when a write current flows through the magnetic junction 400. Therefore, the free layer 410 can be switched using the spin transfer torque. That.

  The nonmagnetic spacer layer 420 may be a tunnel barrier layer, a conductor or other structure whose magnetoresistance is between the free layer 410 and the pinned layer 430. In some embodiments, the nonmagnetic spacer layer 420 is a crystalline MgO tunnel barrier layer. In such embodiments, MgO seed layer 404 and MgO capping layer 406 can be used to improve TMR and other properties of magnetic junction 400. The crystalline MgO tunnel barrier layer 420 is sensitive to the surrounding structures that can affect the deposition of the layer and the annealing of the magnetic junction 400, among other actions, so the MgO seed layer 404 and the MgO capping layer 406 are sensitive. It is postulated that the presence of C improves the crystal structure (structure and / or texture) of the tunnel barrier layer 420.

Although shown as a simple layer in the figure, free layer 410 and / or pinned layer 430 may include multiple layers. For example, free layer 410 and / or pinned layer 430 may be a SAF that includes a magnetic layer that is antiferromagnetically or ferromagnetically coupled through a thin layer such as Ru. Such SAFs can use multiple magnetic layers interleaved with thin layers of Ru or other materials. Further, the free layer 410 and / or the pinned layer 430 may be another multilayer. Although magnetization is not shown in FIG. 12, the free layer 410 and / or pinned layer 430 can each have a perpendicular anisotropy energy that exceeds the out-of-plane demagnetization energy. Thus, free layer 410 and / or pinned layer 430 can each have its magnetic moment oriented perpendicular to the plane. In other embodiments, the magnetic moments of free layer 410 and / or pinned layer 430 are each in a plane. Other orientations of the magnetic moment of free layer 410 and / or pinned layer 430 are possible.

Two magnetic insertion layers 100/100 ′ / 100 ″ are used. These magnetic insertion layers 100/100 ′ / 100 ″ are adjacent to the MgO layers 404 and 406, respectively. Since two magnetic insertion layers 100, 100 ′ and / or 100 ″ are used, the magnetic junction 400 can share the advantages of the magnetic insertion layers 100, 100 ′ and / or 100 ″. Specifically, when the moments are oriented at right angles, the magnetic junction 400 can be thermally more stable and the magnetic junction 400 has a greater perpendicular anisotropy to the layers 410 and / or 430. Can reduce RA, and / or have improved TMR. As explained above, the magnetic insertion layer 100, 100 ′ and / or 100 ″ can reduce the RA of adjacent MgO layers, such as the MgO seed layer 404 and the MgO capping layer 406. The MgO seed layer 404 and Since the parasitic resistance of the MgO capping layer 406 is reduced, the TMR of the magnetic junction 400 can be effectively improved, and the presence of the improved MgO layers 404 and 406 further reduces the RA of the MgO tunnel barrier layer 420. Therefore, the MgO tunnel barrier layer can have its RA improved by the magnetic insertion layer 100/100 ′ / 100 ″. Therefore, the RA of the magnetic junction 400 can be further reduced. Therefore, the performance of the magnetic junction 400 can be improved.

  FIG. 13 shows an exemplary embodiment of a magnetic junction 400 ′ that includes two magnetic insertion layers 100/100 ′ / 100 ″. For clarity, FIG. 13 is drawn to scale. This magnetic junction 400 ′ is similar to the magnetic junction 400. Therefore, similar layers are labeled with similar labels, which are similar to layers 410, 420, and 430, respectively. It includes a free layer 410 ′, a non-magnetic spacer layer 420 ′, and a pinned layer 430 ′, although specific orientation layers 410 ′, 420 ′, and 430 ′ are shown in the figure, this orientation is another embodiment. In the figure, the MgO seed layer 404 ′, the MgO capping layer 406 ′, and the magnetic insertion layer 100/100 ′ / 100 ″ are shown. In some embodiments, an optional pinning layer (not shown) can be included. The magnetic junction 400 'is also configured so that the free layer 410' can be switched between a plurality of stable magnetic states when a write current flows through the magnetic junction 400 '. Therefore, the free layer 410 'can be switched using the spin transfer torque.

  The non-magnetic spacer layer 420 'may be a tunnel barrier layer, conductor or other structure whose magnetoresistance is between the free layer 410' and the pinned layer 430 '. In some embodiments, the non-magnetic spacer layer 420 'is a crystalline MgO tunnel barrier layer. In such embodiments, the MgO seed layer 404 'and the MgO capping layer 406' can be used to improve the TMR and other properties of the magnetic junction 400 '.

Although shown as a simple layer in the figure, the free layer 410 ′ and / or the pinned layer 430 ′ can include multiple layers as described above. Although the magnetization is not shown in FIG. 13, the free layer 410 ′ and / or the pinned layer 430 ′ can each have a perpendicular anisotropy energy that exceeds the out-of-plane demagnetization energy. Thus, the free layer 410 ′ and / or the pinned layer 430 ′ can each have its magnetic moment oriented perpendicular to the plane. In other embodiments, the magnetic moments of the free layer 410 ′ and / or the pinned layer 430 ′ are each in a plane. Other orientations of the magnetic moment of the free layer 410 ′ and / or pinned layer 430 ′ are possible.

Because the magnetic insertion layer 100, 100 ′ and / or 100 ″ is used, the magnetic junction 400 ′ can share the advantages of the magnetic insertion layer 100, 100 ′ and / or 100 ″. In particular, when the moments are oriented at right angles, the magnetic junction 400 ′ can be thermally more stable, and the magnetic junction 400 ′ can be more perpendicular to the layers 410 ′ and / or 430 ′. Can have a low RA and / or have an improved TMR. Therefore, the performance of the magnetic junction 400 ′ can be improved.

  FIG. 14 illustrates an exemplary embodiment of a magnetic junction 400 "that includes two magnetic insertion layers 100/100 '/ 100". For clarity, FIG. 14 is not drawn to scale. This magnetic junction 400 "is similar to the magnetic junction 400 and / or 400 '. Accordingly, similar layers are labeled with similar labels. The magnetic junction 400" has layers 410/410', 420, respectively. / 420 'and 430/430' similar to free layer 410 ", non-magnetic spacer layer 420" and pinned layer 430 ". The figure shows layers 410", 420 "and 430" of specific orientation. However, this orientation can be changed in other embodiments. Also shown are an MgO seed layer 404 ", an MgO capping layer 406" and an adjacent magnetic insertion layer 100/100 '/ 100 ". In some embodiments, an optional pinning layer (not shown) is shown. In addition, the magnetic junction 400 "is configured to switch the free layer 410" between a plurality of stable magnetic states when a write current flows through the magnetic junction 400 ". Has been. Therefore, the free layer 410 ″ can be switched using the spin transfer torque.

  The nonmagnetic spacer layer 420 "may be a tunnel barrier layer, conductor or other structure whose magnetoresistance is between the free layer 410" and the pinned layer 430 ". In some embodiments, the nonmagnetic spacer layer 420" Layer 420 "is a crystalline MgO tunnel barrier layer. As described above, in such embodiments, the MgO seed layer 404 "and MgO capping layer 406" can be used to improve the TMR and other properties of the magnetic junction 400 ".

  Furthermore, the magnetic junction 400 "has a double structure. Therefore, the magnetic junction 400" also includes an additional nonmagnetic spacer layer 440 and an additional pinned layer 450. The nonmagnetic spacer layer 440 may be similar to the nonmagnetic spacer layer 420 ″. Accordingly, the nonmagnetic spacer layer 440 may be a crystalline MgO tunnel barrier layer. In other embodiments, the nonmagnetic spacer layer 440 May be different from layer 420 ". Similarly, pinned layer 450 may be similar to pinned layer 430 ″.

Although shown as a simple layer in the figure, free layer 410 "and / or pinned layers 430" and 450 may include multiple layers as described above. Although the magnetization is not shown in FIG. 14, the free layer 410 "and / or pinned layers 430" and 450 can each have a perpendicular anisotropy energy that exceeds the out-of-plane demagnetization energy. Thus, the free layer 410 "and / or the pinned layers 430" and 450 can each have its magnetic moment oriented perpendicular to the plane. In other embodiments, the magnetic moments of free layer 410 "and / or pinned layer 430" are each in a plane. Other orientations of the magnetic moment of the free layer 410 "and / or pinned layer 430" are possible.

Since the magnetic insertion layer 100, 100 ′ and / or 100 ″ is used, the magnetic junction 400 ″ can share the advantages of the magnetic insertion layer 100, 100 ′ and / or 100 ″. When the moments are oriented at right angles, the magnetic junction 400 "can be made more thermally stable and the magnetic junction 400" has a greater perpendicular anisotropy to the layers 410 "and / or 430". Can reduce RA, and / or have an improved TMR, thus improving the performance of the magnetic junction 400 ".

  FIG. 15 illustrates one exemplary embodiment of a method 500 for manufacturing a magnetic substructure. For simplicity, some steps can be omitted, combined and / or interleaved. Method 500 is described in the context of magnetic junction 200. However, the method 500 can also be used for other magnetic junctions such as junctions 200 ′, 200 ″, 200 ′ ″, 300, 300 ′, 300 ″, 400, 400 ′, and / or 400 ″. Further, method 500 can be incorporated into the manufacture of magnetic storage devices, and thus method 500 can be used in the manufacture of STT-RAM or other magnetic storage devices, and method 500 can also include seed layer 202. And providing an optional pinning layer (not shown).

  Free layer 210 is provided via step 502. Step 502 can include depositing a free layer 210 of a desired material with a desired thickness. Further, step 502 can include providing a SAF. Nonmagnetic layer 220 is provided via step 504. Step 504 may include depositing a desired non-magnetic material, including but not limited to crystalline MgO. Further, in step 504, a desired thickness material can be deposited.

  A pinned layer 230 is provided via step 506. Step 506 can include depositing a pinned layer 230 of a desired material at a desired thickness. Further, step 506 can include providing a SAF. Through step 508, any additional layers such as layers 240 and 250 can optionally be provided. Through step 510, an optional MgO layer, such as layer 204, can be provided. Similarly, at step 510, MgO capping layers such as layers 304 and 406 can be provided. Thus, part of step 510 can be performed before step 502. The magnetic insertion layer 100/100 ′ / 100 ″ may be provided next to the MgO layer 204 via step 512. For the magnetic junction 200, the magnetic insertion layer 100/100 ′ / 100 ″ may be provided at step 502. Can be offered before. However, for magnetic bonding using an MgO capping layer, step 512 can include providing a magnetic insertion layer 100/100 ′ / 100 ″ after steps 508 and / or 510 are performed. 500 of the magnetic insertion layer 100/100 ′ / 100 ″ and the magnetic junction 200, 200 ′, 200 ″, 200 ′ ″, 300, 300 ′, 300 ″, 400, 400 ′ and / or 400 ″. Benefits can be achieved.

  In addition, the magnetic junctions 200, 200 ′, 200 ″, 200 ′ ″, 300, 300 ′, 300 ″, 400, 400 ′ and / or 400 ″ can be used in magnetic storage devices. One exemplary embodiment of one such magnetic storage device 600 is shown, which includes read / write column selection drivers 602 and 606 and a word line selection driver 604. Other Components Note that and / or different components can be provided, the storage area of the magnetic storage device 600 includes magnetic storage cells 610. Each magnetic storage cell includes at least one magnetic junction 612 and at least one selection device. 614. In some embodiments, the selection device 614 is a transistor. Magnetic junction 612, magnetic junctions 200, 200 ', 200', 200 '' ', 300, 300', 300 ', 400, 400' may include one or more of the and / or 400 ". Although one magnetic junction 612 is shown for each cell 610 in the figure, other numbers of magnetic junctions 612 can be provided for each cell in other embodiments.

Various magnetic insertion layers 100, 100 ′ and 100 ″, and magnetic junctions 200, 200 ′, 200 ″, 200 ′ ″, 300, 300 ′, 300 ″, 400, 400 ′ and / or 400 ″ have been disclosed. These magnetic insertion layers 100, 100 ′ and / or 100 ″ and various magnetic junctions 200, 200 ′, 200 ″, 200 ′ ″, 300, 300 ′, 300 ″, 400, 400 ′ and / or 400 ″ Note that various features can be combined. Thus, one or more of the advantages of magnetic junctions 200, 200 ′, 200 ″, 200 ′ ″, 300, 300 ′, 300 ″, 400, 400 ′ and / or 400 ″ can be achieved. For example, small RA, improved perpendicular anisotropy, higher thermal stability and / or greater TMR can be achieved.

  Thus, a method and system for providing a magnetic insertion layer, a magnetic junction, and a memory manufactured using the magnetic junction have been described. These methods and systems have been described in accordance with the exemplary embodiments shown in the figures, and there can be a number of variations to these embodiments, all of which are these methods and Those skilled in the art will readily recognize that they are within the spirit and scope of the system. Accordingly, many modifications may be made by one skilled in the art without departing from the spirit and scope of the appended claims.

10 Conventional magnetic tunnel junction (MTJ)
DESCRIPTION OF SYMBOLS 11 Bottom contact 12 Conventional seed layer 14 Conventional antiferromagnetic (AFM) layer 16 Conventional pinned layer 17 Magnetization 18 Conventional tunnel barrier layer 20 Conventional free layer 21 Changeable magnetization 22 Conventional capping layer 24 Top contact 100, 100 ', 100 "magnetic insertion layer (magnetic underlayer, ferromagnetic insertion layer)
102 magnetic layer 102 ′ first magnetic layer 104 additional magnetic layer 106, 234 nonmagnetic layer 108 second magnetic layer 120, 120 ′, 120 ″ MgO layer 200, 200 ′, 200 ″, 200 ′ ″, 300, 300 ′, 300 ″, 400, 400 ′, 400 ″, 612 Magnetic junction 202, 302 Seed layer 204, 204 ′, 204 ″, 204 ′ ″, 404, 404 ′, 404 ″ MgO seed layer 210, 210 ′, 210 ″, 210 ′ ″, 310, 310 ′, 310 ″, 410, 410 ′, 410 ″ Free layer 220, 220 ′, 220 ″, 220 ′ ″, 320, 320 ′, 320 ″, 420, 420 ′ , 420 "nonmagnetic spacer layer (tunnel barrier layer, nonmagnetic layer)
230, 230 ′, 230 ″, 230 ′ ″, 236, 330, 330 ′, 330 ″, 430, 430 ′, 430 ″ Pinned layer 232 Reference layer 240, 340, 440 Additional nonmagnetic spacer layer 250, 350, 450 Additional pinned layers 304, 304 ', 304 ", 406, 406', 406" MgO capping layer 500 Method for manufacturing magnetic substructure 600 Magnetic storage device 602, 606 Read / write column select driver 610 Magnetic storage cell 614 selection device

Claims (17)

A magnetic junction for use in a magnetic device,
A pinned layer,
A nonmagnetic spacer layer;
A free layer, wherein the nonmagnetic spacer layer is present between the pinned layer and the free layer;
A first insulating layer adjacent to the free layer ;
A second insulating layer adjacent to the pinned layer;
A first magnetic insert layer adjacent to the first insulating layer,
A second magnetic insertion layer adjacent to the second insulating layer;
With
Wherein the first insulating layer comprises a first MgO layer,
The second insulating layer comprises a second MgO layer;
The first MgO layer is a seed layer or a capping layer;
The first magnetic insertion layer and the second magnetic insertion layer include a magnetic layer made of at least one of CoX, FeX, and CoFeX, and X is B, Ge, Hf, Zr, Ti, Ta, and Selected from Tb,
A magnetic junction configured to switch the free layer between a plurality of stable magnetic states when a write current flows through the magnetic junction. The magnetic junction of claim 1, wherein the first magnetic insertion layer and / or the second magnetic insertion layer further comprises an additional magnetic layer. The magnetic junction of claim 2 , wherein the additional magnetic layer comprises at least one of Co and Fe. The first magnetic insertion layer and / or the second magnetic insertion layer further includes an additional magnetic layer composed of at least one of CoY, FeY, and CoFeY, where Y is B, Ge, Hf, Zr, The magnetic junction according to claim 1, which is selected from Ti, Ta, and Tb. The magnetic junction according to claim 1, wherein the second MgO layer is a seed layer adjacent to the pinned layer. The magnetic junction according to claim 1, wherein the second MgO layer is a capping layer adjacent to the pinned layer.   The magnetic junction of claim 1, wherein the free layer has a free layer perpendicular anisotropy greater than a free layer out-of-plane demagnetization energy. The magnetic junction according to claim 7 , wherein the pinned layer has a pinned layer perpendicular anisotropy greater than a pinned layer out-of-plane demagnetization energy. A plurality of magnetic memory cells, each of the plurality of magnetic memory cells including at least one magnetic junction, wherein the at least one magnetic junction is adjacent to a pinned layer, a nonmagnetic spacer layer, a free layer, and the free layer A first insulating layer, a second insulating layer adjacent to the pinned layer, a first magnetic insertion layer adjacent to the first insulating layer, and a second magnetic insertion layer adjacent to the second insulating layer The non-magnetic spacer layer is present between the pinned layer and the free layer , the first insulating layer is made of a first MgO layer, and the second insulating layer is made of a second MgO layer. It becomes the first MgO layer is a seed layer or a capping layer, the first magnetic insert layer and the second magnetic insert layer, CoX, FeX and magnetic layer of at least one of the CoFeX X is B, Ge, H , Zr, Ti, Ta and Tb, and the magnetic junction is configured to switch the free layer between a plurality of stable magnetic states when a write current flows through the magnetic junction. A plurality of magnetic storage cells,
A magnetic storage device comprising a plurality of bit lines. The magnetic storage device according to claim 9 , wherein the first magnetic insertion layer and / or the second magnetic insertion layer further includes an additional magnetic layer. The magnetic storage device according to claim 10 , wherein the additional magnetic layer includes at least one of Co and Fe. The first magnetic insertion layer and / or the second magnetic insertion layer further includes an additional magnetic layer composed of at least one of CoY, FeY, and CoFeY, where Y is B, Ge, Hf, Zr, The magnetic storage device according to claim 9 , wherein the magnetic storage device is selected from Ti, Ta, and Tb. The magnetic storage device according to claim 9 , wherein the second MgO layer is a seed layer adjacent to the pinned layer. The magnetic storage device according to claim 9 , wherein the second MgO layer is a capping layer adjacent to the pinned layer. The magnetic storage device according to claim 9 , wherein the free layer has a free layer perpendicular anisotropy greater than a free layer out-of-plane demagnetization energy. The magnetic storage device according to claim 9 , wherein the pinned layer has a pinned layer perpendicular anisotropy greater than a pinned layer out-of-plane demagnetization energy. A method for providing a magnetic junction for use in a magnetic device comprising:
Providing a pinned layer;
Providing a non-magnetic spacer layer;
Providing a free layer, wherein the non-magnetic spacer layer is present between the pinned layer and the free layer;
Providing a first MgO layer adjacent to the free layer ;
Providing a second MgO layer adjacent to the pinned layer;
Providing a first magnetic insert layer adjacent to said first MgO layer,
And a step of providing a second magnetic insert layer adjacent to the second MgO layer, before Symbol first MgO layer, a seed layer or a capping layer, the first magnetic insert layer and the second Two magnetic insertion layers include a magnetic layer made of at least one of CoX, FeX, and CoFeX, wherein X is selected from B, Ge, Hf, Zr, Ti, Ta, and Tb, and the magnetic junction includes: A method configured to allow the free layer to switch between a plurality of stable magnetic states when a write current flows through the magnetic junction.

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