CN210110840U - Magnetic memory device - Google Patents
Magnetic memory device Download PDFInfo
- Publication number
- CN210110840U CN210110840U CN201921308124.0U CN201921308124U CN210110840U CN 210110840 U CN210110840 U CN 210110840U CN 201921308124 U CN201921308124 U CN 201921308124U CN 210110840 U CN210110840 U CN 210110840U
- Authority
- CN
- China
- Prior art keywords
- layer
- free layer
- magnetic
- channel isolation
- memory device
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Mram Or Spin Memory Techniques (AREA)
- Hall/Mr Elements (AREA)
Abstract
The utility model relates to the field of magnetic memories, in particular to a magnetic memory device, which comprises a fixed layer, a channel isolation layer and a free layer; the channel isolation layer is located between the pinned layer and the free layer; the non-magnetic layer is located on the free layer and is different from the free layer in material. The utility model discloses can effectively reduce the critical current that changes MTJ free layer magnetization direction, reduce the magnetic storage device volume.
Description
Technical Field
The utility model relates to a magnetic memory device field especially relates to a MTJ magnetic memory device.
Background
Magnetic memories are of great interest for faster write speeds, longer information retention, and potentially lower power performance than existing memories on the market.
The core device of the magnetic memory device is a Magnetic Tunnel Junction (MTJ), the MTJ is composed of a free layer, a fixed layer and a channel isolation layer between the free layer and the fixed layer, the free layer and the fixed layer are two layers of magnetic materials, the magnetization directions of the free layer and the fixed layer are the same or not, the resistance of the MTJ is determined, when the magnetization directions of the free layer and the fixed layer are parallel and opposite, the resistance of the MTJ is larger, and when the magnetization directions of the free layer and the fixed layer are parallel and the same, the resistance of the MTJ is smaller. By determining the magnitude of the MTJ resistance, the magnetic memory device can be used to read and write data.
Both industrial and consumer magnetic memories require smaller and smaller structures. For MTJ, the smaller the structure, the smaller the critical current (also called the lowest flipped magnetization direction current) required for the free layer; in the case where the free layer magnetic material is unchanged or is not improved much, how to reduce the critical current density becomes the key for the MTJ structure optimization.
SUMMERY OF THE UTILITY MODEL
The utility model discloses an improve the MTJ structure in the current STT-MRAM, arouse the supplementary free layer magnetization direction that changes of non-parallel atomic magnetic moment in the free layer through the peculiar structure to obviously reduce critical current.
The utility model provides a magnetic memory device, which comprises a fixed layer, a channel isolation layer and a free layer; the channel isolation layer is located between the pinned layer and the free layer; wherein the free layer has first and second opposing faces, the second face being distal from the channel spacer than the first face, the first face being non-parallel to the second face.
Preferably, the first face is a non-centrosymmetric face structure.
Preferably, the first surface is a curved surface structure
Preferably, the first face is a planar structure.
Preferably, the first face is in contact with the channel barrier layer.
Preferably, a non-magnetic thin film layer is provided between the first face and the channel isolation layer.
Preferably, the fixed layer and the free layer are at least one of CoFe, NiFe, CoFeB, CoFeCr, CoFePt, cofedd, CoFeTb, CoFeGd, or CoFeNi.
Preferably, the device further comprises a first electrode and a second electrode; the first electrode is located below the fixed layer and the second electrode is located above the free layer.
Preferably, a semiconductor device is further included, the semiconductor device being electrically connected to the fixed layer.
Preferably, the device further comprises a substrate located below the fixed layer.
Preferably, the non-magnetic structure is located in the free layer, and the non-magnetic structure is made of a different material from the free layer.
Preferably, the free layer has first and second opposing faces, the first face opposing the channel isolation layer, the nonmagnetic structure being located on the second face surface.
Preferably, the non-magnetic structure is a non-centrosymmetric structure.
Preferably, the non-magnetic structure is ring-shaped or band-shaped.
Preferably, the nonmagnetic structure penetrates the free layer.
Preferably, there are at least 2 of said non-magnetic structures.
Preferably, the non-magnetic structural material is at least one of magnesium, titanium, chromium, copper oxy/nitride.
Preferably, the free layer has first and second opposing faces, the first face opposing the channel isolation layer, with a non-magnetic thin film layer therebetween.
Preferably, the magnetic memory further comprises a nonmagnetic layer, and the nonmagnetic structure is positioned on the free layer.
The utility model provides a magnetic memory device improves through adopting the free layer curved surface, adding non-magnetic structure in the free layer and adding the structure of non-magnetic layer on the free layer, arouses the atomic magnetic moment that produces the non-parallelism in the free layer, and supplementary free layer magnetization direction overturns to can obviously reduce critical current, have the good effect that reduces the structure of MTJ.
Drawings
FIG. 1 is a schematic cross-sectional view of the structure of one embodiment of the magnetic memory device of the present invention;
FIG. 2 is a schematic cross-sectional view of the magnetic moment of an excited atom near the free layer curved surface;
FIG. 3 is a schematic cross-sectional view of another embodiment of the magnetic memory device of the present invention;
FIG. 4 is a schematic cross-sectional view of a nonmagnetic band exciting a magnetic moment of an atom in a free layer.
FIGS. 5A-5C are top views of the non-magnetic strip of section A-A' of FIG. 3.
Fig. 6 is a schematic cross-sectional view of another embodiment of the magnetic memory device of the present invention.
Detailed Description
The following describes in detail a specific embodiment of the magnetic memory device according to the present invention with reference to the accompanying drawings.
In the drawings, the dimensional ratios of layers and regions are not actual ratios for the convenience of description. When a layer (or film) is referred to as being "on" another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may also be present. In addition, when a layer is referred to as being "under" another layer, it can be directly under, and one or more intervening layers may also be present. In addition, when a layer is referred to as being between two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present. Like reference numerals refer to like elements throughout.
The present embodiment provides a magnetic memory device, as shown in fig. 1, a core device MTJ includes a pinned layer 41, a channel isolation layer 42, a free layer 43; the channel isolation layer 42 is located between the pinned layer 41 and the free layer 43; the free layer 43 has a first face (lower face) and a second face (upper face) that are opposite, the second face (upper face) being farther from the channel isolation layer 42 than the first face (lower face), that is, the first face (lower face) being opposite to the channel isolation layer 42, the first face (lower face) being non-parallel to the second face (upper face).
In the conventional STT-MRAM (free layer upper and lower surface parallel structure), when the free layer 43 is formed on the channel isolation layer 42, due to the reason that the stress caused by the cooling of the channel isolation layer 42, the tension caused by the temperature of the free layer 43, the material of the channel isolation layer 42 and the free layer 43 are different, and the like, an upper and lower blending structure may be locally formed on the interface, and the applicant finds that, during the read-write process, the upper and lower blending structure is beneficial to exciting a micro atomic magnetic moment (such as AMM shown in fig. 2) in the free layer 43, so as to assist the free layer 43 to change the magnetization direction, and reduce the critical current required by the free layer 43 to change the magnetization direction; however, at the same time, the up-and-down fused structure deteriorates the uniformity of the channel isolation layer 42, so that the lifetime of the channel isolation layer 42 is reduced. Therefore, how to excite in the free layer to form more atomic magnetic moments which are not parallel and take into account the service life of the channel isolation layer becomes the direction of the main research of the utility model.
Therefore, in the present embodiment, the free layer 43 has a first surface (lower surface) and a second surface (upper surface) that are not parallel, the thickness of the channel isolation layer 42 is uniform, and it is helpful to excite more atomic magnetic moments near the first surface (lower surface) of the free layer 43 to assist the free layer 43 to change the magnetization direction during the reading and writing processes, so as to reduce the critical current required for changing the magnetization direction of the free layer 43.
In another embodiment, the first (lower) face of the free layer 43 is a non-centrosymmetric structure. As shown in fig. 1, the first (lower) surface is a curved surface structure. When the structure is used for reading and writing, an atomic magnetic moment AMM (the direction of the shown magnetic moment is only schematic, and negative electron flow directions are different, so that atomic magnetic moments in different directions can be excited) as shown in FIG. 2 is easily formed in the free layer 43, wherein a small number of the atomic magnetic moments AMM0 which are horizontally parallel and a large number of the atomic magnetic moments AMM1 and AMM2 which are not horizontal are adopted, and a non-central symmetry plane structure is adopted, so that the unbalance of the quantity of AMM1 and AMM2 is facilitated, the sum of the atomic magnetic moment vectors is non-parallel, the magnetization direction of the free layer 43 is assisted to be changed, and the critical current required for changing the magnetization direction of the free layer 43.
In another embodiment, the first (lower) surface may be a planar structure (not shown), i.e., the cross-section of the free layer 43 is a wedge-shaped structure, which helps to excite more atomic magnetic moments near the first (lower) surface of the free layer 43 to assist the free layer 43 to change the magnetization direction, thereby reducing the critical current required to change the magnetization direction of the free layer 43.
In this embodiment, as shown in fig. 1 and fig. 2, the first surface (lower surface) of the free layer 43 is in contact with the channel isolation layer 42, and the channel isolation layer 42 is made of different materials by the free layer 43, so that the excitation of atomic magnetic moments in the first surface (lower surface) of the free layer 43 assists to change the magnetization direction of the free layer 43.
In another embodiment, in order to excite the atomic magnetic moments according to different materials, applicants dispose a non-magnetic thin film layer (not shown) between the first surface (lower surface) of the free layer 43 and the channel isolation layer 42, so that the excitation of more atomic magnetic moments in the first surface (lower surface) of the free layer 43 assists in changing the magnetization direction of the free layer 43.
Preferably, the non-magnetic thin film layer (not shown) is a discontinuous structure, and in order to allow for the lifetime of the channel isolation layer 42, the discontinuous non-magnetic thin film layer is embedded in the first (lower) surface of the free layer 43.
Preferably, the non-magnetic thin film layer (not shown) is a discontinuous structure that is a portion within the upper surface of channel isolation layer 42, and is formed by processing the upper surface of channel isolation layer 42 in order to allow for the lifetime of channel isolation layer 42.
In this embodiment, the fixed layer 41 and the free layer 43 are at least one of CoFe, NiFe, CoFeB, CoFeCr, CoFePt, cofespd, CoFeTb, CoFeGd, or CoFeNi, and it should be noted that the thickness of the fixed layer 41 is larger than that of the free layer 43.
In the present embodiment, as shown in fig. 1, the display device further includes a first electrode 3 and a second electrode 5; the first electrode 3 is located below the fixed layer 41, and the second electrode 5 is located above the free layer 43.
In the present embodiment, as shown in fig. 1, a semiconductor device (not shown) is further included, the semiconductor device (not shown) is disposed in the substrate 1, the substrate 1 is located below the fixed layer 41, and the semiconductor device is electrically connected to the fixed layer 41. The electrical connection is made through the first electrical conductor 200 in the first interlayer dielectric layer 20.
Preferably, the first electrical conductor 200 is a metal, such as at least one of titanium, tantalum, copper, aluminum, or tungsten; or a conductive metal nitride such as at least one of titanium nitride and tantalum nitride.
In the present embodiment, as shown in fig. 1, the second conductor 210 in the second interlayer dielectric layer 21 is connected to the second electrode 5, thereby electrically connecting the bit line (not shown) and the MTJ.
Preferably, the second conductor 210 is the same material as the first conductor, and will not be described herein.
In another embodiment, as shown in FIG. 3, comprises a fixed layer 41, a channel isolation layer 42, a free layer 43; the channel isolation layer 42 is located between the pinned layer 41 and the free layer 43; and nonmagnetic structures 61 and 62, the nonmagnetic structures 61 and 62 are located in the free layer 43, the nonmagnetic structures 61 and 62 are made of different materials from the free layer 43, so that more non-parallel atomic magnetic moments AMM are excited in the second surface (upper surface) of the free layer 43 as shown in fig. 4 (the directions of the magnetic moments are only shown schematically, and the directions of negative electrons are different, so that atomic magnetic moments in different directions are excited), and the magnetization direction of the free layer 43 is changed.
It should be noted that the non-magnetic structures 61 and 62 in fig. 3 are only schematic diagrams, and in the prior art, it is easier to form the non-magnetic structures 61 and 62 on the second surface (upper surface) of the free layer 43, and the non-magnetic structures 61 and 62 are easier to form pits due to etching the free layer 43, but it is not excluded that the non-magnetic structures are in the middle of the free layer (i.e., the embodiment where the free layer completely includes the non-magnetic structures 61 and 62).
It should also be noted that in the case of the non-magnetic structures 61 and 62 provided in the free layer 43, the free layer, the fixed layer and the channel isolation layer may adopt a stripe-shaped stack structure in the existing STT-MRAM technology, without using a form in which the first face (lower face) and the second face (upper face) of the free layer 43 are not parallel or the first face (lower face) adopts a curved surface as shown in fig. 3.
In the present embodiment, as shown in fig. 3 and 4, the nonmagnetic structures 61 and 62 are located in the second plane.
In the present embodiment, as shown in fig. 4, in order to form more non-parallel atomic magnetic moments in the second plane (upper surface), the non-magnetic structures 61 and 62 are each a non-centrosymmetric structure in a side cross section.
In the present embodiment, as shown in fig. 5A to 5C, the planar structure of the nonmagnetic structures 61 and 62 is a ring or a band due to the planar structure of the MTJ entity or the magnetic memory cell; of course, the band-shaped nonmagnetic structures 61 and 62 may be formed in the circular MTJ or magnetic memory cell top view structure, and the ring-shaped nonmagnetic structures 61 and 62 may be formed in the square MTJ or magnetic memory cell top view structure.
In another embodiment, the nonmagnetic structures 61 and 62 penetrate (not shown) the free layer 43, that is, the upper and lower surfaces of the nonmagnetic structures 61 and 62 are respectively connected to the second electrode 5 and the channel isolation layer 42, and in such a structure, not only the atomic magnetic moments are formed in the upper and lower surfaces of the free layer 43, but also the atomic magnetic moments are formed in the middle of the free layer 43, which helps to change the magnetization direction of the free layer 43, and thus the critical current required for changing the magnetization direction of the free layer 43 is greatly reduced.
In this embodiment, there are at least 2 nonmagnetic structures. The present embodiment is not limited thereto, and only one nonmagnetic structure may be provided in the case where the nonmagnetic structures 61 and 62 penetrate the free layer 43.
In the present embodiment, the non-magnetic materials 61 and 62 are at least one of magnesium, titanium, chromium, and copper oxy/nitride.
Similarly, in this embodiment, in order to excite the atomic magnetic moments according to different materials, applicants have disposed a non-magnetic thin film layer (not shown) between the first surface (lower surface) of the free layer 43 and the channel isolation layer 42, so that excitation in the first surface (lower surface) of the free layer 43 forms more atomic magnetic moments to assist in changing the magnetization direction of the free layer 43.
Preferably, the non-magnetic thin film layer (not shown) is a discontinuous structure, and in order to allow for the lifetime of the channel isolation layer 42, the discontinuous non-magnetic thin film layer is embedded in the first (lower) surface of the free layer 43.
Preferably, the non-magnetic thin film layer (not shown) is a discontinuous structure that is a portion within the upper surface of channel isolation layer 42, and is formed by processing the upper surface of channel isolation layer 42 in order to allow for the lifetime of channel isolation layer 42.
As shown in fig. 3, the semiconductor device (not shown), the substrate 1, the first conductor 200, the first interlayer dielectric layer 20, the first electrode 20, the second electrode 5, the second interlayer dielectric layer 21, the second electrode 210, and the bit line (not shown) and their connection relations are the same as those in fig. 1, and the applicant does not need to describe any further here.
In another embodiment, as shown in FIG. 6, a magnetic memory device includes a fixed layer 41, a channel isolation layer 42, a free layer 43; the channel isolation layer 42 is located between the pinned layer 41 and the free layer 43; and a nonmagnetic layer 6, wherein the nonmagnetic layer 6 is positioned on the free layer 43, and the nonmagnetic layer 6 is different from the material of the free layer 43, so that the excitation of the formed atomic magnetic moment in the second surface (upper surface) of the free layer 43 assists to change the magnetization direction of the free layer 43 and reduce the critical current for changing the magnetization direction of the free layer 43.
Note that in the case where the nonmagnetic layer 6 is provided on the free layer 43, the free layer, the fixed layer, and the channel isolation layer may adopt a stripe-shaped stack structure in the existing STT-MRAM technology, without using a form in which the first face (lower face) and the second face (upper face) of the free layer 43 are not parallel or the first face (lower face) adopts a curved face as shown in fig. 6. Of course, the critical current for changing the magnetization direction of the free layer 43 can be further reduced by using the form in which the first surface (lower surface) and the second surface (upper surface) of the free layer 43 are not parallel or the first surface (lower surface) is curved as shown in fig. 6.
It should be noted that in the case where the nonmagnetic layer 6 is provided on the free layer 43, it is not necessary to provide the nonmagnetic structures 61 and 62 shown in fig. 3 in the free layer, and of course, the effect of using the nonmagnetic structures 61 and 62 shown in fig. 3 is more significant.
Also, in this embodiment, in order to excite the atomic magnetic moments according to the different materials, applicants have disposed a non-magnetic thin film layer (not shown) between the first surface (lower surface) of the free layer 43 and the channel isolation layer 42, so that the excitation of more atomic magnetic moments in the first surface (lower surface) of the free layer 43 assists in changing the magnetization direction of the free layer 43.
Preferably, the non-magnetic thin film layer (not shown) is a discontinuous structure, and in order to allow for the lifetime of the channel isolation layer 42, the discontinuous non-magnetic thin film layer is embedded in the first (lower) surface of the free layer 43.
Preferably, the non-magnetic thin film layer (not shown) is a discontinuous structure that is a portion within the upper surface of channel isolation layer 42, and is formed by processing the upper surface of channel isolation layer 42 in order to allow for the lifetime of channel isolation layer 42.
In the present embodiment, the materials of the nonmagnetic layer 6 as shown in fig. 6, the nonmagnetic structures 61 and 62 and the nonmagnetic thin film layer (not shown) in fig. 3 may be the same, and are each at least one of magnesium, titanium, chromium, copper oxy/nitride.
In this embodiment, as shown in fig. 6, the semiconductor device (not shown), the substrate 1, the first conductor 200, the first interlayer dielectric layer 20, the first electrode 20, the second electrode 5, the second interlayer dielectric layer 21, the second electrode 210, and the bit line (not shown) and their connection relations are the same as those in fig. 1, and the applicant does not need to describe any further here.
The utility model provides a magnetic memory device improves through adopting the free layer curved surface, adding non-magnetic structure in the free layer and adding the structure of non-magnetic layer on the free layer, arouses the atomic magnetic moment that produces the non-parallelism in the free layer, and the supplementary free layer magnetization direction that changes obviously reduces critical current, has the good effect that reduces the structure of MTJ.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of improvements and decorations can be made without departing from the principle of the present invention, and these improvements and decorations should also be regarded as the protection scope of the present invention.
Claims (7)
1. A magnetic memory device includes
A fixed layer, a channel isolation layer, a free layer;
the channel isolation layer is located between the pinned layer and the free layer;
it is characterized in that the preparation method is characterized in that,
the non-magnetic layer is located on the free layer and is different from the free layer in material.
2. The magnetic memory device of claim 1, wherein the non-magnetic layer material is at least one of magnesium, titanium, chromium, copper oxy/nitride.
3. The magnetic memory device of claim 1, wherein the free layer has first and second opposing faces, the second face being further from the channel isolation layer than the first face, there being a non-magnetic thin film layer between the first face and the channel isolation layer.
4. The magnetic memory device of claim 1, wherein the fixed layer and the free layer are at least one of CoFe, NiFe, CoFeB, CoFeCr, CoFePt, cofewd, CoFeTb, CoFeGd, or CoFeNi.
5. The magnetic memory device of claim 1, further comprising a first electrode and a second electrode; the first electrode is located below the fixed layer and the second electrode is located above the free layer.
6. The magnetic memory device of claim 1, further comprising a semiconductor device electrically connected to the fixed layer.
7. The magnetic memory device of claim 1, further comprising a substrate located below the fixed layer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921308124.0U CN210110840U (en) | 2019-08-13 | 2019-08-13 | Magnetic memory device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921308124.0U CN210110840U (en) | 2019-08-13 | 2019-08-13 | Magnetic memory device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN210110840U true CN210110840U (en) | 2020-02-21 |
Family
ID=69567684
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201921308124.0U Active CN210110840U (en) | 2019-08-13 | 2019-08-13 | Magnetic memory device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN210110840U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110620175A (en) * | 2019-08-13 | 2019-12-27 | 上海新微技术研发中心有限公司 | Magnetic memory device |
-
2019
- 2019-08-13 CN CN201921308124.0U patent/CN210110840U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110620175A (en) * | 2019-08-13 | 2019-12-27 | 上海新微技术研发中心有限公司 | Magnetic memory device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| TWI455300B (en) | Stt-mram cell structures | |
| US7919826B2 (en) | Magnetoresistive element and manufacturing method thereof | |
| US6510078B2 (en) | Memory cell array and method for manufacturing it | |
| US7919794B2 (en) | Memory cell and method of forming a magnetic tunnel junction (MTJ) of a memory cell | |
| EP1793433B1 (en) | Spacer structure in MRAM cell and method of its fabrication | |
| JP5623507B2 (en) | Magnetic layered body having spin torque switching and having a layer for assisting switching of spin torque | |
| JP5283922B2 (en) | Magnetic memory | |
| US7727778B2 (en) | Magnetoresistive element and method of manufacturing the same | |
| US20100254182A1 (en) | Magnetic storage device | |
| EP1239489A1 (en) | Method for fabricating cladding layer in top conductor | |
| US8659939B2 (en) | Spin-torque memory with unidirectional write scheme | |
| JP2009512204A (en) | Magnetoresistive tunnel junction element and its application to MRAM | |
| KR20080070597A (en) | Magnetoresistive element and magnetic memory | |
| US11950514B2 (en) | Confined cell structures and methods of forming confined cell structures | |
| JP2008218829A (en) | Magnetoresistance element and manufacturing method thereof | |
| US7733611B2 (en) | Magnetoresistance effect element comprising nano-contact portion not more than a mean free path and magnetic head utilizing same | |
| CN210110839U (en) | Magnetic memory device | |
| CN210110840U (en) | Magnetic memory device | |
| CN210110841U (en) | Magnetic memory device | |
| JP2008294420A (en) | Magnetoresistive element, and manufacturing method thereof | |
| EP2786384B1 (en) | Spin transfer torque magnetic storage element with low write error rate | |
| CN110620175A (en) | Magnetic memory device | |
| CN117677277A (en) | Spin-orbit-torque memory cell, method for manufacturing same and magnetic random access memory | |
| KR100684893B1 (en) | Magnetic memory device and method of fabricating the same | |
| KR100763921B1 (en) | Magnetic random access memory device using current induced switching |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |