A magnetic device and method for programming the magnetic device are described. The magnetic device includes a plurality of magnetic junctions and at least one spin-orbit interaction (SO) active layer having a plurality of sides and an axis. The SO active layer(s) carry a current in direction(s) substantially perpendicular to the plurality of sides along the axis. Each of the magnetic junction(s) is adjacent to the sides and substantially surrounds a portion of the SO active layer. Each magnetic junction includes a free layer, a reference layer and a nonmagnetic spacer layer between the pinned and free layers. The SO active layer(s) exert a SO torque on the free layer due to the current passing through the SO active layer(s). The free layer is switchable between stable magnetic states. The free layer may be written using the current and, in some aspects, another current driven through the magnetic junction.
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1. A magnetic device comprising:
at least one spin-orbit interaction (SO) active layer having a plurality of sides and an axis, the at least one SO active layer carrying a current in at least one direction substantially perpendicular to the plurality of sides along the axis; and
at least one magnetic junction, each of the at least one magnetic junction being adjacent to the plurality of sides, extending around the axis, and substantially surrounding a portion of the SO active layer, each of the at least one magnetic junction including a free layer, a reference layer and a nonmagnetic spacer layer, the nonmagnetic spacer layer being between the reference layer and the free layer;
a first line configured to drive a current through the SO active layer along the axis, the at least one SO active layer exerting a SO torque around the axis on the free layer due to the current passing through the at least one SO active layer along the axis, the free layer being switchable between a plurality of stable magnetic states; and
a second line configured to drive current through the at least one magnetic junction.
14. A method for writing to at least one magnetic junction of a magnetic device comprising:
driving, with a first line, a spin-orbit interaction (SO) write current through at least one SO active layer having a plurality of sides and an axis, the at least one SO active layer carrying the SO write current in at least one direction substantially perpendicular to the plurality of sides along the axis, the at least one magnetic junction, each of the at least one magnetic junction being adjacent to the plurality of sides, extending around the axis, and substantially surrounding a portion of the SO active layer, each of the at least one magnetic junction including at least a free layer, a reference layer and a nonmagnetic spacer layer, the nonmagnetic spacer layer being between the reference layer and the free layer, the at least one SO active layer exerting a SO torque along the axis on the free layer due to the SO write current passing through the at least one SO active layer along the axis; and
driving, with a second line, a spin transfer torque (STT) write current through the at least one magnetic junction.
13. A magnetic device comprising:
a plurality of spin-orbit interaction (SO) active layers, each of the plurality of SO active layers having a plurality of sides and an axis, each of the plurality of SO active layers carrying a current in at least one direction substantially perpendicular to the plurality of sides along the axis;
at least one magnetic junction coupled with each of the plurality of SO active layers, each of the at least one magnetic junction being adjacent to the plurality of sides extending around the axis, and substantially surrounding a portion each of the plurality of SO active layers, each of the at least one magnetic junction including a free layer, a reference layer and a barrier layer, the barrier layer being between the reference layer and the free layer;
a first line configured to drive a current through each of the plurality of SO active layers, each of the plurality of SO active layers exerting a SO torque along the axis on the free layer due to the current passing through each of the plurality of SO active layers along the axis, the free layer being switchable between a plurality of stable magnetic states, the plurality of stable magnetic states of the free layer being selected from a first stable axis along the at least one direction; a second stable state parallel to the plurality of sides and a radial direction substantially perpendicular to the plurality of sides; and
a plurality of lines coupled with the reference layer of the at least one magnetic junction, the plurality of lines being configured to drive current through the at least one magnetic junction.
0. 2. The magnetic device of
a reference layer; and
a nonmagnetic spacer layer, the nonmagnetic spacer layer being between the reference layer and the free layer.
3. The magnetic device of
a substrate, each of the at least one magnetic junction forming a nonzero angle with the substrate.
5. The magnetic device of
6. The magnetic device of
7. The magnetic device of
8. The magnetic device of
a selection device coupled with the at least one SO active layer.
9. The magnetic device of
11. The magnetic device of
12. The magnetic device of
at least one isolation device interleaved with the plurality of magnetic junctions.
0. 15. The method of
16. The method of claim 15 14 further comprising:
driving a the spin transfer torque (STT) write current through the at least one magnetic junction while the SO write current is driven through the SO active layer, a final magnetic state of the free layer being set by the STT write current.
17. The method of claim 15 14 further comprising:
driving a the spin transfer torque (STT) write current through the at least one magnetic junction after the SO write current starts to be driven through the SO active layer.
18. The method of claim 15 14 further comprising:
driving a the spin transfer torque (STT) write current through the at least one magnetic junction after the SO write current terminates.
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This and an axis. The SO active layer(s) carry a current in direction(s) substantially perpendicular to the plurality of sides along the axis. Each of the magnetic junction(s) is adjacent to the sides and substantially surrounds a portion of the SO active layer. Each magnetic junction includes a free layer, a reference layer and a nonmagnetic spacer layer between the pinned and free layers. The SO active layer(s) exert a SO torque on the free layer due to the current passing through the SO active layer(s). The free layer is switchable between stable magnetic states. The free layer may be written using the current and, in some aspects, another current driven through the magnetic junction.
The magnetic junction 110 includes a free layer 112, a nonmagnetic spacer layer 114 and a reference layer 116. The magnetic junction 110 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 the reference layer 116 and the nonmagnetic spacer layer 114 and/or between the nonmagnetic spacer layer 114 and the free layer. Contact, optional seed layer(s) and optional capping layer(s) may be present but are not shown for simplicity. An optional pinning layer (not shown) may be used to fix the magnetization (not shown) of the reference layer 116. The optional pinning layer may be an AFM layer or multilayer that pins the magnetization (not shown) of the reference layer 116 by an exchange-bias interaction. However, in other embodiments, the optional pinning layer may be omitted or another structure may be used. In other embodiments, discussed below, the reference layer 116 and nonmagnetic spacer layer 114 might be omitted.
Also not shown in
The reference layer 116 is magnetic and may be a multilayer. For example, the reference layer 116 may be a synthetic antiferromagnet (SAF) including multiple ferromagnetic layers interleaved with and sandwiching nonmagnetic layer(s) such as Ru. Other multilayers may be used in the reference layer 116. For example, the reference layer 116 may include or consist of one or more of CoFe, CoFeB, FeB, and/or CoPt. Note that as used herein CoFeB, FeB, CoB, CoPt and other materials listed denote alloys in which the stoichiometry is not indicated. For example, CoFeB may include (CoFe)1-xBx, where x is greater than or equal to zero and less than or equal to 0.5 as-deposited. For example, x may be at least 0.2 and not more than 0.4. Other materials and/or structures are possible for the reference layer 116. The magnetic moment of the reference layer 116 may take on various configurations that are discussed below.
The nonmagnetic NM spacer layer 114 is between reference layer 116 and the free layer 112. The nonmagnetic spacer layer 114 may be a tunneling barrier layer. For example, the nonmagnetic spacer layer 114 may include or consist of MgO, aluminum oxide and/or titanium oxide. The MgO layer may be crystalline and have a 200 orientation for enhanced tunneling magnetoresistance (TMR). In other embodiments, the nonmagnetic spacer layer 114 may be a different tunneling barrier layer, may be a conductive layer or may have another structure.
The free layer 112 is magnetic and may be a multilayer. The free layer 112 may be a SAF or other multilayer. For example, the free layer 112 may include or consist of one or more of CoFe, CoFeB and/or Fe. The magnetic moment of the free layer 112 may have various stable states that are discussed below. The free layer is adjacent to the sides of the SO active layer 130. In the embodiment shown, the sides of the SO active layer 130 are cylindrical and perpendicular to the x-y plane. The free layer 112 is substantially perpendicular to the x-y plane and cylindrical. In the embodiment shown in
The magnetic junction 110 is configured such that the free layer 112 is switchable between stable magnetic states using a write current which is passed through the SO active layer 130 along the axis of the SO active layer 130 (e.g. along the z axis/±z direction in
The SO active layer 130 is a layer that has a strong spin-orbit interaction and is used in switching the magnetic moment (not shown) of the free layer 112. For example, the SO active layer may include or consist of materials having a large SO angle with large spin-orbit coupling such as one or more of T, W, IrMn, or Pt, or a topological insulator, such as BiTe, BiSe, BiSb, and/or SbTe. Although termed a “layer”, in the embodiment shown in
As discussed above, the stable magnetic states of the free layer 112, as well as the reference layer 116, may take on various configurations.
The magnetic junction 110B includes free layer 112B, nonmagnetic spacer layer 114 and reference layer 1168 116B that are analogous to the free layer 112, nonmagnetic spacer layer 114 and reference layer 116, respectively. Consequently, the structure, function and materials used in the layers 112B, 114 and 1168 116B are analogous to those for the layers 112, 114 and 116. However, the magnetic moments 1138 113B and 1178 117B of the free layer 112B and reference layer 1168 116B, respectively, are explicitly shown. The reference layer magnetic moment 1178 117B circulates around the z-axis and, therefore, around the SO active layer 130. The free layer stable states also circulate around the z-axis. The magnetic device 1008 100B may have improved scalability, may use lower current densities for switching (e.g. less than 3 MA/cm2) and may be thermally stable, but may require larger switching times (e.g. greater than 10 nanoseconds).
The magnetic junction 110C includes free layer 112C, nonmagnetic spacer layer 114 and reference layer 116C that are analogous to the free layer 112, nonmagnetic spacer layer 114 and reference layer 116, respectively. Consequently, the structure, function and materials used in the layers 112C, 114 and 116C are analogous to those for the layers 112, 114 and 116. However, the magnetic moments 113C and 117C of the free layer 112C and reference layer 116C, respectively, are explicitly shown. The reference layer magnetic moment 117C is radial. In the embodiment shown, the moment 117C is toward the z-axis. In another embodiment, the moment 117C might be radial away from the z-axis. Similarly, the free layer stable states are also radial. The magnetic device 100C may deliver intermediate performance. For example, the magnetic device 100C have improved scalability, may use interfacial perpendicular magnetic anisotropy (I-PMA) for improved thermal stability, may use intermediate current densities (e.g. greater than 20 MA/cm2) and may have somewhat smaller switching times (e.g. <1 nanosecond), but may be less thermally stable.
Thus, three particular configurations of magnetic moments are shown in magnetic junctions 110A, 110B and 110C. In another embodiment, other configurations might be used.
Referring back to
In programming the magnetic junction 110, however, a write current is driven through the SO active layer 130 and substantially perpendicular to the sides of the SO active layer 130 adjacent to the free layer 112. In the embodiment shown, this is along the z axis. Based on the direction of current, spins polarized in opposite directions may drift to opposing sides of the SO active layer 130. Because the free layer 112 and magnetic junction 110 substantially surround the sides of the SO active layer 130, all of these polarized spins may be used in writing to the free layer 112. In some embodiments, the stable magnetic states of the free layer 112 are configured such that the SO torque due to these spins can switch the magnetic state of the free layer 112.
For example,
In contrast,
The magnetic devices 100, 100A, 100B and 100C may have improved performance. The free layer 112/112A/112B/112C may be programmed using SO torque and a current driven through the SO active layer 130. Because no STT write current is driven through the magnetic junction 110 for programming, damage to the magnetic junction 110 may be avoided. For example, breakdown of the tunneling barrier layer 114 may be circumvented. Even if an STT write current is driven through the magnetic junction 110/110A/110B/110C, the magnitude of the current may be smaller. Thus, damage to the magnetic junction 110/110A/110B/110C may be reduced or prevented. Moreover, the interface for the SO torque to act on the free layer 112/112A/112B/112C may be enhanced. As such, a smaller write current may be driven through the SO active layer 130 while still writing to the magnetic junction 110/110A/110B/110C. The configuration of the magnetic junction 110/110A/110B/110C and SO active layer 130 may be more scalable and switching time reduced. Writing may be primarily achieved using a current through the SO active layer, while reading performed using a current through the magnetic junction. As a result, read and write may be separately optimized.
The magnetic junction 110E includes free layer 112E, nonmagnetic spacer layer 114E and reference layer 116E that are analogous to the free layer 112, nonmagnetic spacer layer 114 and reference layer 116, respectively. Consequently, the structure, function and materials used in the layers 112E, 114E and 116E are analogous to those for the layers 112, 114 and 116. Similarly, the SO active layer 130E is analogous to the SO active layer 130. Consequently, the structure, function and materials used in the SO active layer 130E are analogous to those used in the SO active layer 130. The magnetic junction 110E and SO active layer 130E are square in footprint instead of circular. Thus, the magnetic device 100 is not limited to a circular footprint. In addition, an interlayer 118 is shown. This interlayer 118 resides between the SO active layer 130E and the free layer 112E. The layer 118 may be used to moderate (enhance and/or decrease) interaction between the free layer 112E and the SO active layer 130E. For example, the SO torque may be enhanced.
The magnetic junction 110F includes free layer 112F, nonmagnetic spacer layer 114F and reference layer 116F that are analogous to the free layer 112, nonmagnetic spacer layer 114 and reference layer 116, respectively. Consequently, the structure, function and materials used in the layers 112F, 114F and 116F are analogous to those for the layers 112, 114 and 116. Similarly, the SO active layer 130F is analogous to the SO active layer 130. Consequently, the structure, function and materials used in the SO active layer 130F are analogous to those used in the SO active layer 130. The magnetic junction 110E and SO active layer 130F are rectangular in footprint instead of circular. In addition, the magnetic junction 110F is shown as not completely surrounding the SO active layer 130F. Instead, aperture or slot 119 is present. However, as discussed above, in generally, it is desirable for the magnetic junction to surround the SO active layer in order to increase the area available for interaction via SO torque.
However, the line 131 includes both the SO active layer 130G and a core 132. The core 132 may have a lower conductivity/higher resistivity than the SO active layer 130G. For example, the core 132 may be formed of material(s) including but not limited to polysilicon, SiN and/or SiO.
The magnetic device 100G may share the benefits of the magnetic devices 100, 100A, 100B, 100C, 100D, 100E and/or 100F. In addition, the current may be preferentially carried through the SO active layer 130G, closer to the interface with the free layer 112. As a result, the SO active layer 130G and the line 131 may have improved efficiency in delivering SO torque to the free layer 112. Thus, performance of the magnetic device 100G may be further improved.
The magnetic junction 110H includes a free layer 112 that is analogous to the free layer 112 of the magnetic junction 110. Thus, the materials and configuration of the free layer 112 in the magnetic junction 110H is analogous to that in the magnetic junction 110. For example, the free layer 112 may be a SAF or other multilayer. The magnetic junction 110H may also include optional PEL(s) having a high spin polarization. Contact, optional seed layer(s) and optional capping layer(s) may be present but are not shown for simplicity. Although the free layer 112 is shown as adjoining the SO active layer 130, in other embodiments, a layer, such as interlayer 118, may be inserted between the sides of the SO active layer 130 and the free layer 112. Further, although shown as completely surrounding the sides of the SO active layer 130, in other embodiments, the free layer 112 may include an aperture or may terminate without completely surrounding the SO active layer 130.
Thus, the magnetic junction 100H includes a free layer 112. However, the nonmagnetic spacer layer 114 and a reference layer 116 of the magnetic junction 110 are omitted. Consequently, STT is not used in programming the free layer 112. In some embodiments, an external magnetic field may be used in addition to SO torque to write to the free layer 112. In addition, the magnetic junction 110H is read using a current driven along the z-axis through the SO active layer 130 that is insufficient to program the free layer 112.
For example,
Although specific magnetic devices 100, 100A, 100B, 100C, 100D, 100E, 100F, 100G and 100H and particular magnetic junctions 110, 110A, 110B, 110C, 110D, 110E, 110F, 110G and 110H have been described herein, one of ordinary skill in the art will recognize that one or more of the features described herein may be combined in manners not explicitly shown.
The memory 200A includes a substrate 202, lines 201 and 203 and memory cells 210A. Each memory cell 210A includes a selection transistor 220A, magnetic junction 212 and SO active layer 211. Although only one magnetic junction 212 per cell is shown, in other embodiments, additional magnetic junctions may be used. The SO active layer 211 is analogous to the SO active layer 130 and/or 130G/line 131. The magnetic junctions 212 are analogous to the magnetic junction(s) 110, 110A, 110B, 1100, 110D, 110E, 110F, 110G, 110H and/or another vertical magnetic junction. In addition, as can be seen by the orientation of the magnetic junctions 212 with respect to the substrate 202, the magnetic junctions 212 have interfaces (not shown) that may be substantially perpendicular to the substrate 202. The transistor 220A shown are planar transistors. In another embodiment, another selection device might be used. For example, an ovonic threshold selector (OTS) device might be used. In addition, also shown are lines 201 that may be used to drive current through the magnetic junction 212 for reading and/or writing. However, if a free layer only magnetic junction 100H is used, the lines 201 may be omitted. Because the magnetic memory 200A uses the magnetic junctions 212 and SO active layers 211, the magnetic memory 200A may enjoy the benefits described above.
The memory 200B includes a substrate 202, lines 201 and 203 and memory cells 210B. Each memory cell 210B includes a selection transistor 220B, magnetic junction 212 and SO active layer 211. Although only one magnetic junction 212 per cell is shown, in other embodiments, additional magnetic junctions may be used. The SO active layer 211 is analogous to the SO active layer 130 and/or 130G/line 131. The magnetic junctions 212 are analogous to the magnetic junction(s) 110, 110A, 110B, 1100, 110D, 110E, 110F, 110G, 110H and/or another vertical magnetic junction. In addition, as can be seen by the orientation of the magnetic junctions 212 with respect to the substrate 202, the magnetic junctions 212 have interfaces (not shown) that may be substantially perpendicular to the substrate 202. The transistor 220B shown are planar transistors. In another embodiment, another selection device including but not limited to an OTS selection device might be used. Also shown are lines 201 that may be used to drive current through the magnetic junction 212 for reading and/or writing. However, if a free layer only magnetic junction 100H is used, the lines 201 may be omitted.
Also shown in
The memory 200C includes a substrate 202, lines 201 and 203 and memory cells 210C. Each memory cell 210C includes a selection transistor 220C, magnetic junction 212 and SO active layer 211. An optional second selection device 230C is also shown. Although only one magnetic junction 212 per cell is shown, in other embodiments, additional magnetic junctions may be used. The SO active layer 211 is analogous to the SO active layer 130 and/or 130G/line 131. The magnetic junctions 212 are analogous to the magnetic junction(s) 110, 110A, 110B, 110C, 110D, 110E, 110F, 110G, 110H and/or another vertical magnetic junction. In addition, as can be seen by the orientation of the magnetic junctions 212 with respect to the substrate 202, the magnetic junctions 212 have interfaces (not shown) that may be substantially perpendicular to the substrate 202. Also shown are lines 201 that may be used to drive current through the magnetic junction 212 for reading and/or writing. However, if a free layer only magnetic junction 100H is used, the lines 201 may be omitted. The transistor 220C shown are vertical (three-dimensional) transistors instead of planar transistors.
Because the magnetic memory 200C uses the magnetic junctions 212 and SO active layers 211, the magnetic memory 200C may enjoy the benefits described above. In addition, if two selection devices 220C and 230C are used, the sneak path for current may be reduced or eliminated. As such, performance may be further improved. Further, the magnetic memory 200C may be more scalable because of the use of three dimensional transistors 220C. Thus, the magnetic memory 200C may have enhanced performance.
The magnetic memory 300A includes word lines 301, Vcc/Vdd/ground/read voltage lines 303, Vcc/Vdd/ground/floating lines 305, output lines 307 that may connect to a sense amplifier, magnetic junctions 312, SO active layers 311, selection transistor 320 and optional additional selection device 330A. The components 311, 312, 320 and (optionally) 330A form cells 310A. For simplicity only one cell is labeled. Each magnetic junction 312 is shown as connected to line 307. However, if a free layer only magnetic junction 100H is used this connection may be omitted.
Because the magnetic memory 300A uses the magnetic junctions 312 and SO active layers 311, the magnetic memory 300A may enjoy the benefits described above. In addition, if two selection devices 320 and 330A are used, the sneak path for current may be reduced or eliminated. As such, performance may be further improved. If the transistor 320 is a vertical transistor such as the transistor 220C, the magnetic memory 300A may be more scalable. Thus, the magnetic memory 300A may exhibit improved performance.
The magnetic memory 300B is analogous to the magnetic memory 300A. Consequently, the magnetic memory 300B includes word lines 301, Vcc/Vdd/ground/read voltage lines 303, Vcc/Vdd/ground/floating lines 305, output lines 307 that may connect to a sense amplifier, magnetic junctions 312, SO active layers 311 and selection transistor 320 that are analogous to components 301, 303, 305, 307, 312, 311 and 320, respectively. The components 311, 312, 320 and (optionally) 332B form cells 310B. For simplicity only one cell is labeled. Each magnetic junction 312 is shown as connected to line 307. However, if a free layer only magnetic junction 100H is used this connection may be omitted.
Each memory cell 310B may include an optional diode 332B. The diode 332B may be used to eliminate the sneak path. In lieu of a diode 332B, another configuration that functions as a diode may be used.
Because the magnetic memory 300B uses the magnetic junctions 312 and SO active layers 311, the magnetic memory 300B may enjoy the benefits described above. In addition, if the diodes 332B are used, the sneak path for current may be reduced or eliminated. As such, performance may be further improved. If the transistor 320 is a vertical transistor such as the transistor 220C, the magnetic memory 300B may be more scalable. Thus, the magnetic memory 300B may exhibit improved performance.
In some embodiments, the magnetic junctions 412 may be individually programmed using a combination of current driven through the SO active layers 411 (i.e. using SO torque) and a current driven through the magnetic junction (e.g. STT torque). Such embodiments include those in which the SO torque is collinear with the magnetization, such as the magnetic junction 1008. For example, a write current that is insufficient to write to the magnetic junction 412 alone may be driven through the SO active layer 411. Each magnetic junction 412 to be written may simultaneously have an STT current driven through it. For example, the STT current may be radial or simply in a particular direction that allows the STT current to pass through the interface(s) between the layers of the magnetic junction 412. The combination of the currents driven in the appropriate directions writes to the desired magnetic junctions 412. In some embodiments, an STT current driven in one direction through the magnetic junctions 412 to be switched aids in programming, while an STT current driven in the opposite direction through magnetic junctions 412 not to be switched prevents writing to such magnetic junctions from being programmed. In other embodiments, a current is driven through the SO active layer 411. A small STT current may be driven through the magnetic junctions 412 desired to be written, for example to select the final direction of magnetization after programming. In some embodiments, the magnetic moment of the free layer of each magnetic junction 412 may be stable radially, in a manner analogous to the magnetic junction 100C. A current driven through the SO active layer may destabilize the magnetic moments such that the free layer magnetic moments circulate around the SO active layer 411. The final direction of magnetization may be set by applying a small STT current to the magnetic junction(s) 412 desired to be programmed. When the currents are removed, the magnetic junctions 412 are programmed in the desired radial direction. In another embodiment, the magnetic moment of the free layer of each magnetic junction 412 is stable axially (along the axis of the cylinder shown in
At least one SO active layer 130 is provided, via step 502. Step 502 may include depositing and patterning the desired materials for each SO active layer 130. In some embodiments, step 502 includes forming the low conductivity core 132 and the SO active layer 130G on the core 132. Thus, a pillar may be formed in step 502. The interlay layer 118 may optionally be provided as part of step 502.
The magnetic junctions 110 may then be formed, via step 504. Step 504 may include blanket depositing the layers for the free layer 112, nonmagnetic spacer layer 114, reference layer 116 and any additional layers desired in the magnetic junction 110. Alternatively, the nonmagnetic spacer layer 114 and/or reference layer 114 might be omitted. Anneal(s) and/or other processing steps may also be performed. The magnetic junctions 110 may then be defined. For example, a planarization step may remove the portions of the magnetic junctions 110 connection layer 112, 114 and 116 and the SO active layer 130 physically exposed.
Fabrication may then be completed, via step 506. For example, isolation and/or selection devices may be formed. If magnetic devices 400A and/or 400B are to be fabricated, then subsequent SO active layers 130 and magnetic junctions 110 may be formed.
Using the method 500, the magnetic devices 100, 100A, 100B, 00C 100C, 100D, 100E, 100F, 100G, and/or analogous magnetic devices may be fabricated. As a result, the benefits of the magnetic devices 100, 100A, 100B, 00C 100C, 100D, 100E, 100F and/or 100G may be achieved.
The desired current is driven through the SO active layer 130/line 131, via step 512. Thus, the current is driven along the axis of the SO active layer 130/lienline 131 and substantially perpendicular parallel to the sides. In embodiments, in which the current through the SO torque is sufficient to program the device as desired, then the method 510 terminates.
However, in some embodiments, multiple currents are used to program a magnetic junction. Thus, an additional STT current may be driven, via step 512. In some embodiments, the STT current is driven through the magnetic junctions to be programmed. In such embodiments, the STT current is desired to assist in programming and/or select the final state of the free layer 112. In other embodiments, the STT current may be driven through magnetic junctions whether or not they are to be programmed. In such embodiments, the direction of the STT current provided in step 514 depends upon whether the magnetic junction 110 is to be programmed. If so, the STT current is driven in a direction that adds to the SO torque. If not, the STT current is driven in a direction such that the STT torque opposes the SO torque. In some embodiments, the current through the SO active layer 130 commence at substantially the same time as the STT current. In other embodiments, the current through the SO active layer is started first, and the STT current commences later. Similarly, in some embodiments, the current through the SO active layer 130 may be terminated before the STT current goes to zero. In other embodiments, the STT current may be terminated before the current through the SO active layer 130. In still other embodiments, the current through the SO active layer 130 and the STT current through the magnetic junction may be terminated at substantially the same time. However, in most embodiments, the current through the SO active layer 130 and the STT current overlap in time.
Thus, the magnetic junctions 110, 110A, 110B, 110C, 110D, 110E, 110F, 110G, 110H, 212, 312 and/or 412 may be programmed. As a result, the benefits of the magnetic device(s) 100, 100A, 100B, 100C, 100D, 100E, 100F, 100G, 100H, 200, 200B, 200C, 300A, 300B, 400A and/or 400B may be achieved.
A method and system for providing and using a magnetic junction and a memory fabricated using the magnetic junction has been described. The method and system have been described in accordance with the exemplary embodiments shown, and one of ordinary skill in the art will readily recognize that there could be variations to the embodiments, and any variations would be within the spirit and scope of the method and system. Accordingly, many modifications may be made by one of ordinary skill in the art without departing from the spirit and scope of the appended claims.
Nikitin, Vladimir, Apalkov, Dmytro
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