CN110120452A - Magnetic tunnel junction and magnetic RAM with it - Google Patents
Magnetic tunnel junction and magnetic RAM with it Download PDFInfo
- Publication number
- CN110120452A CN110120452A CN201810113910.9A CN201810113910A CN110120452A CN 110120452 A CN110120452 A CN 110120452A CN 201810113910 A CN201810113910 A CN 201810113910A CN 110120452 A CN110120452 A CN 110120452A
- Authority
- CN
- China
- Prior art keywords
- magnetosphere
- magnetic
- layer
- tunnel junction
- magnetic tunnel
- 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.)
- Pending
Links
- 230000005291 magnetic effect Effects 0.000 title claims abstract description 163
- 229910052751 metal Inorganic materials 0.000 claims abstract description 41
- 239000002184 metal Substances 0.000 claims abstract description 41
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 36
- 229910021389 graphene Inorganic materials 0.000 claims abstract description 35
- 239000011248 coating agent Substances 0.000 claims abstract description 31
- 238000000576 coating method Methods 0.000 claims abstract description 31
- 230000004888 barrier function Effects 0.000 claims abstract description 24
- 239000000463 material Substances 0.000 claims description 20
- 229910019236 CoFeB Inorganic materials 0.000 claims description 11
- 230000005389 magnetism Effects 0.000 claims description 5
- 229910052741 iridium Inorganic materials 0.000 claims description 4
- 229910052742 iron Inorganic materials 0.000 claims description 4
- 239000000203 mixture Substances 0.000 claims description 4
- 229910052759 nickel Inorganic materials 0.000 claims description 4
- 229910052763 palladium Inorganic materials 0.000 claims description 4
- 229910052707 ruthenium Inorganic materials 0.000 claims description 4
- 229910052715 tantalum Inorganic materials 0.000 claims description 4
- 229910052721 tungsten Inorganic materials 0.000 claims description 4
- 229910003321 CoFe Inorganic materials 0.000 claims description 3
- 239000000956 alloy Substances 0.000 claims description 3
- 229910045601 alloy Inorganic materials 0.000 claims description 3
- 230000008859 change Effects 0.000 claims description 2
- 230000005415 magnetization Effects 0.000 abstract description 11
- 238000005036 potential barrier Methods 0.000 abstract description 7
- 238000009987 spinning Methods 0.000 abstract description 6
- 230000005540 biological transmission Effects 0.000 abstract description 5
- 238000000034 method Methods 0.000 description 11
- 239000010408 film Substances 0.000 description 10
- 230000008021 deposition Effects 0.000 description 4
- 238000013019 agitation Methods 0.000 description 3
- 150000001336 alkenes Chemical class 0.000 description 3
- 230000008878 coupling Effects 0.000 description 3
- 238000010168 coupling process Methods 0.000 description 3
- 238000005859 coupling reaction Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 230000005294 ferromagnetic effect Effects 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 239000004575 stone Substances 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000014759 maintenance of location Effects 0.000 description 2
- 239000010409 thin film Substances 0.000 description 2
- 230000004913 activation Effects 0.000 description 1
- 230000005290 antiferromagnetic effect Effects 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 238000013500 data storage Methods 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 229910001385 heavy metal Inorganic materials 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000008439 repair process Effects 0.000 description 1
- 239000011435 rock Substances 0.000 description 1
- 238000005549 size reduction Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N50/00—Galvanomagnetic devices
- H10N50/10—Magnetoresistive devices
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N50/00—Galvanomagnetic devices
- H10N50/80—Constructional details
Landscapes
- Hall/Mr Elements (AREA)
- Mram Or Spin Memory Techniques (AREA)
Abstract
The present invention provides a kind of magnetic tunnel junction and with its magnetic RAM.The magnetic tunnel junction includes magnetic fixing layer, barrier layer and the synthetic free layer that sequence is stacked, wherein, synthetic free layer includes the first magnetosphere that sequence is stacked, second magnetosphere and graphene coating, graphene coating is located at side of second magnetosphere far from barrier layer, and the first magnetosphere has the vertical direction of magnetization with the second magnetosphere.Since graphene has the spinning current transmission range (micron order) of overlength much larger than 10 nanometer scales in common metal, also there is lower resistivity, to on the basis of the first magnetosphere and potential barrier bed boundary provide the first perpendicular magnetic anisotropy, the second magnetosphere is set to form the last the second perpendicular magnetic anisotropy with graphene coating, so that magnetic tunnel junction is still able to maintain excellent perpendicular magnetic anisotropy on the basis of total magnetic layer thickness is biggish.
Description
Technical field
The present invention relates to technical field of data storage, in particular to a kind of magnetic tunnel junction and with its magnetism
Random access memory.
Background technique
Magnetic tunnel junction (MTJ) is the device based on tunnel magnetoresistive (TMR) effect, usually by two layers of magnetosphere and between magnetic
Property layer among dielectric layer composition.First magnetic layer is orientated fixed (fixing layer), and the second magnetic layer orientation can lead to
It crosses magnetic field or electric current changes (free layer), and then two layers of magnetospheric direction of magnetization is made to be in parallel or anti-parallel state, correspondence is low
Resistance states and high-resistance state can be used to store information.
Spin transfer torque magnetic RAM (ST-MRAM) changes MTJ state using electric current, compared with conventional memory device
It is a kind of novel memory devices of great potential with very various advantages.The memory is in addition to, reading simple with circuit design
Outside the advantages that writing rate is fast and erasable infinitely, the sharpest edges relative to legacy memory such as DRAM are non-volatile (disconnected
Electric data are not lost).The magnetic direction of free layer (magnetic recording layer) can be manipulated by outfield (H) or write current (I).Work as freedom
When the layer direction of magnetization is parallel or antiparallel with fixing layer, data 0 or 1 can be respectively corresponded.
A Core Superiority of ST-MRAM is its non-volatile, that is, the data stored in ST-MRAM after powering off will not lose
It loses, this requires must have enough potential barriers in MTJ between binary states magnetic caused by hot activation effect is stopped to overturn.According to statistics
Probability, data hold time can be expressed as: τ=τ0Exp Δ=τ0exp(E/kBT), wherein τ0It is characterized the time；E is energy
Barrier height depends on anisotropy energy and free layer volume；Δ is the energy barrier height after reduction.In order to reach 10 years
Data hold time needs to meet Δ > 41.For the perpendicular magnetization material of present mainstream, Δ=HkAt/kBT, wherein HkFor
Effective perpendicular magnetic anisotropy, A and t are respectively the area and thickness of free layer in storage unit MTJ, and T is temperature, kBHereby for Bohr
Graceful constant.As memory cell size reduces, area A and size reduce at quadratic relationship, save to reach same data
Time needs to increase thickness and cannot reduce effective anisotropy energy.
However, vertical magnetism anisotropy mostlys come from interface, therefore, magnetic anisotropy increases with magnetic film thickness
And it reduces.By taking common perpendicular magnetic anisotropy material as an example (such as MgO | CFB | Ta), only in magnetosphere CFB thickness lower than about
Perpendicular magnetic anisotropy is just shown as when 1.5nm.
Increase and reduced magnetic anisotropy to improve with magnetic film thickness, it is thick increasing thin magnetic film (such as CFB)
While spending, generally require to introduce interface in thin magnetic film, for example, by using MgO | CFB (1~1.5nm) | Ta (0.2~0.5)
Nm | CFB (1~1.5nm) | Ta structure.(it is located at the Ta material between two layers of CFB by introducing relatively thin 20 ' of metal separating layer
Layer) obtain 10 ' of magnetosphere | 20 ' of metal separating layer | 10 ' structure (as shown in Figure 1) of magnetosphere, so that two layers in synthetic free layer
10 ' of magnetosphere shows as perpendicular magnetic anisotropy, and is for two layers ferromagnetic coupling, keeps direction consistent in switching process.The party
Method is able to maintain perpendicular magnetic anisotropy, but introduces non-magnetic metal layer in film and will affect damped coefficient and the spin polarization of material
Rate.
Further, 30 ' of top cover layer of heavy metal can also be used, to obtain 30 ' of top cover layer | magnetosphere
10 ' | 20 ' of metal separating layer | 10 ' structure (as shown in Figure 1) of magnetosphere is provided stronger by the Quantum geometrical phase of interface
Interface perpendicular magnetic anisotropy.However, the above method can generally dramatically increase damped coefficient, to increase write current, and then increase
It MRAM energy consumption and writes voltage and reduces to insert and write number.Top cover layer can also be formed using MgO, MgO coating mentions
For additional perpendicular magnetic anisotropy.However, this method will lead to resistance-area product (RA) increase, TMR is reduced, therefore MgO covers
Cap rock is needed using low resistance area technique.
Summary of the invention
The main purpose of the present invention is to provide a kind of magnetic tunnel junction and with its magnetic RAM, to solve
The problem of magnetic anisotropy of magnetic tunnel junction in the prior art increases with magnetic film thickness and is reduced.
To achieve the goals above, according to an aspect of the invention, there is provided a kind of magnetic tunnel junction, including sequential layer
Magnetic fixing layer, barrier layer and the synthetic free layer of folded setting, wherein synthetic free layer includes the first magnetic that sequence is stacked
Property layer, the second magnetosphere and graphene coating, graphene coating are located at side of second magnetosphere far from barrier layer, and
One magnetosphere has the vertical direction of magnetization with the second magnetosphere.
Further, the sum of the first magnetosphere and the second magnetospheric thickness are greater than 1.5nm.
Further, the first magnetospheric thickness is greater than 0.7nm.
Further, second is magnetospheric with a thickness of 0.2nm~1.5nm.
Further, forming the first magnetospheric material is CoFeB or CoFe.
Further, the alloy that the second magnetospheric material is selected from any one or more of composition of Co, Ni and Fe is formed.
Further, magnetic tunnel junction further include be set between the first magnetosphere and the second magnetosphere it is first non magnetic
Metal layer, preferably the first non-magnetic metal layer with a thickness of 0.2nm~1nm.
Further, any of the material of the first non-magnetic metal layer in Mo, Pt, Ta, Ir, W, Pd and Ru is formed
Kind.
Further, magnetic fixing layer includes the third magnetosphere being stacked, the second non-magnetic metal layer and artificial anti-
Ferromagnetic layer, and artificial inverse ferric magnetosphere is located at side of second non-magnetic metal layer far from barrier layer.
According to another aspect of the present invention, a kind of magnetic RAM, including magnetic tunnel junction, magnetic tunnel are provided
Become above-mentioned magnetic tunnel junction.
Apply the technical scheme of the present invention, provide it is a kind of including be sequentially stacked magnetic fixing layer, barrier layer and
The magnetic tunnel junction of synthetic free layer, since the synthetic free layer includes the first magnetosphere that sequence is stacked, second is magnetic
Layer and graphene coating, graphene coating are located at side of second magnetosphere far from barrier layer, and the first magnetosphere and the
Two magnetospheres have the vertical direction of magnetization, and graphene has the spinning current transmission range (micron order) of overlength much larger than common
10 nanometer scales in metal also have lower resistivity, hang down to provide first in the first magnetosphere and potential barrier bed boundary
On the basis of straight anisotropy, the second magnetosphere is set to form the last the second perpendicular magnetic anisotropy with graphene coating, in turn
So that magnetic tunnel junction is still able to maintain excellent perpendicular magnetic anisotropy on the basis of total magnetic layer thickness is biggish.
Detailed description of the invention
The Figure of description for constituting a part of the invention is used to provide further understanding of the present invention, and of the invention shows
Examples and descriptions thereof are used to explain the present invention for meaning property, does not constitute improper limitations of the present invention.In the accompanying drawings:
Fig. 1 shows provided a kind of the schematic diagram of the section structure of synthetic free layer in the prior art；
Fig. 2 shows a kind of the schematic diagram of the section structure of magnetic tunnel junction provided by embodiment of the present invention；
Fig. 3 shows the schematic diagram of the section structure of another kind magnetic tunnel junction provided by embodiment of the present invention.
Wherein, the above drawings include the following reference numerals:
10 ', magnetosphere；20 ', metal separating layer；30 ', top cover layer；10, magnetic fixing layer；20, barrier layer；30,
Synthetic free layer；310, the first magnetosphere；320, the second magnetosphere；330, graphene coating；340, the first nonmagnetic metal
Layer.
Specific embodiment
It should be noted that in the absence of conflict, the feature in embodiment and embodiment in the present invention can phase
Mutually combination.The present invention will be described in detail below with reference to the accompanying drawings and embodiments.
In order to enable those skilled in the art to better understand the solution of the present invention, below in conjunction in the embodiment of the present invention
Attached drawing, technical scheme in the embodiment of the invention is clearly and completely described, it is clear that described embodiment is only
The embodiment of a part of the invention, instead of all the embodiments.Based on the embodiments of the present invention, ordinary skill people
The model that the present invention protects all should belong in member's every other embodiment obtained without making creative work
It encloses.
It should be noted that description and claims of this specification and term " first " in above-mentioned attached drawing, "
Two " etc. be to be used to distinguish similar objects, without being used to describe a particular order or precedence order.It should be understood that using in this way
Data be interchangeable under appropriate circumstances, so as to the embodiment of the present invention described herein.In addition, term " includes " and " tool
Have " and their any deformation, it is intended that cover it is non-exclusive include, for example, containing a series of steps or units
Process, method, system, product or equipment those of are not necessarily limited to be clearly listed step or unit, but may include without clear
Other step or units listing to Chu or intrinsic for these process, methods, product or equipment.
As described in background technique, vertical magnetism anisotropy mostlys come from interface in the prior art, therefore,
Magnetic anisotropy increases with magnetic film thickness and is reduced.The present inventor studies regarding to the issue above, proposes
A kind of magnetic tunnel junction, as shown in Figures 2 and 3, including be sequentially stacked magnetic fixing layer 10, barrier layer 20 and it is compound from
By layer 30, wherein synthetic free layer 30 includes the first magnetosphere 310 that sequence is stacked, the second magnetosphere 320 and graphene
Coating 330, graphene coating 330 are located at the second side of the magnetosphere 320 far from barrier layer 20, and the first magnetosphere 310
There is the vertical direction of magnetization with the second magnetosphere 320.
Since synthetic free layer includes the first magnetosphere that sequence is stacked, the second magnetosphere in above-mentioned magnetic tunnel junction
With graphene coating, graphene coating is located at side of second magnetosphere far from barrier layer, and the first magnetosphere and second
Magnetosphere has the vertical direction of magnetization, and graphene has the spinning current transmission range (micron order) of overlength much larger than common gold
10 nanometer scales in category also have lower resistivity, thus vertical with the offer first of potential barrier bed boundary in the first magnetosphere
On the basis of anisotropy, the second magnetosphere is set to form the last the second perpendicular magnetic anisotropy with graphene coating, and then make
It obtains magnetic tunnel junction and is still able to maintain excellent perpendicular magnetic anisotropy on the basis of total magnetic layer thickness is biggish.
It is only thick in magnetosphere CFB for perpendicular magnetic anisotropy material commonly used in the prior art (such as MgO | CFB | Ta)
Perpendicular magnetic anisotropy is just shown as when degree is lower than about 1.5nm；And in above-mentioned magnetic tunnel junction of the invention, by the way that stone is arranged
Black alkene coating can make the sum of thickness of the first magnetosphere 310 and the second magnetosphere 320 be greater than 1.5nm, to make magnetic tunnel
Road knot can have excellent perpendicular magnetic anisotropy and biggish total magnetic layer thickness simultaneously.
In above-mentioned magnetic tunnel junction of the invention, it is preferable that the thickness of the first magnetosphere 310 be greater than 0.7nm, pass through by
The thickness limit of first magnetosphere 310 in above-mentioned preferred range, can be conducive to magnetospheric crystalline structure growth and
Its magnetic field orientating has biggish thermal stability for the thermal agitation of environment；And, it is preferable that the thickness of the second magnetosphere 320
Between 0.2nm to 1.5nm, by by the thickness limit of the second magnetosphere 320 in above-mentioned preferred range, can be advantageous
In magnetospheric crystalline structure growth and its magnetic field orientating is for the thermal agitation of environment has biggish thermal stability.
In above-mentioned magnetic tunnel junction of the invention, those skilled in the art can be according to the prior art to forming the first magnetic
Property layer 310 and the second magnetosphere 320 material carry out Rational choice, it is preferable that formed the first magnetosphere 310 material be
CoFeB or CoFe, the material for forming the second magnetosphere 320 are selected from the alloy of any one or more of composition of Co, Ni and Fe.By
It is non-strong Quantum geometrical phase material in above-mentioned material, to make the damped coefficient very little of free layer, also, uses above-mentioned material
Material can retain free layer structure MgO conventional in the prior art | CFB, to improve CFB crystallization by increasing CFB thickness
Quality, and then further promote magnetic tunnel magnetic resistance (TMR).
In a preferred embodiment, synthetic free layer 30 is by the first magnetosphere 310, the second magnetosphere 320 and stone
Black 330 sequential layer of alkene coating is stacked, as shown in Fig. 2, at this point, above-mentioned first magnetosphere 310 and above-mentioned second magnetosphere 320
Between directly contact form ferromagnetic coupling, it is vertical respectively to different that the first magnetosphere 310 with the interface of barrier layer 20 provides strong interface
Property, the interface of the second magnetosphere 320 and graphene coating 330 provides another strong interface perpendicular magnetic anisotropy, two contributions
Superposition, so that two layers of magnetosphere in synthetic free layer 30 is easy to vertically magnetize, still is able to have in MTJ size reduction
There is higher anisotropy energy, resists thermal agitation so as to guarantee enough energy barriers；Magnetic in synthetic free layer 30
Property material internal does not have nonmagnetic portion, so as to improve spin polarizability；Also, for traditional mtj structure, work as freedom
The direction of magnetization is unfavorable for improving the density of MRAM, and compound freedom of the invention along thin film planar when thickness degree is greater than 1.5nm
Layer 30 has above structure, can not only improve MRAM density, also advantageously improves tunnel magnetoresistive rate, reduces write current, simultaneously
With low write current and high data retention over time.
In another preferred embodiment.Magnetic tunnel junction further includes being set to the first magnetosphere 310 and the second magnetic
Property layer 320 between the first non-magnetic metal layer 340, at this point, synthetic free layer 30 include sequence be stacked it is first magnetic
The 310, first non-magnetic metal layer 340 of layer, the second magnetosphere 320 and graphene coating 330, as shown in Figure 3.First is non magnetic
The introducing of metal layer 340 can make the tool of synthetic free layer 30, and there are four film layer interfaces, respectively barrier layer 20 and the first magnetosphere
310 interface, the interface of the first magnetosphere 310 and the first non-magnetic metal layer 340, the first non-magnetic metal layer 340 and second
The interface of magnetosphere 320 and the interface of the second magnetosphere 320 and graphene coating 330, each interface can be formed compared with
Strong perpendicular magnetic anisotropy makes entire free layer have very strong perpendicular magnetic anisotropy, using above-mentioned synthetic free layer 30
MTJ size can be accomplished 10nm hereinafter, greatly improving MRAM capacity, when free layer thickness is more than 2nm or more by structure
Appoint and so keeps good perpendicular magnetic anisotropy and thermal stability.
In above-mentioned preferred embodiment, it is preferable that the thickness of the first non-magnetic metal layer 340 is between 0.2nm to 1nm
Between, by the way that the thickness limit of the first non-magnetic metal layer 340 in above-mentioned preferred range, is made the first non-magnetic metal layer
340 can be realized the interface to be formed and be contacted with upper and lower two magnetospheres, to form stronger perpendicular magnetic anisotropic, Er Qiexuan
Selecting above-mentioned thickness range will not cause to cause spinning current to intensify loss since the first non-magnetic metal layer 340 is too thick；And
And those skilled in the art can carry out Rational choice to above-mentioned first non-magnetic metal layer 340 according to the prior art, in order to make
Two layers of magnetosphere in synthetic free layer 30 can show good perpendicular magnetic anisotropy, it is preferable that it is non magnetic to form first
The material of metal layer 340 is selected from any one of Mo, Pt, Ta, Ir, W, Pd and Ru.
In above-mentioned magnetic tunnel junction of the invention, it is preferable that magnetic fixing layer 10 includes the third magnetism being stacked
Layer, the second non-magnetic metal layer and artificial inverse ferric magnetosphere, and artificial inverse ferric magnetosphere is located at the second non-magnetic metal layer far from potential barrier
The side of layer 20.I.e. above-mentioned magnetic fixing layer 10 is the composite construction of one layer of magnetosphere and artificial inverse ferric magnetosphere structure, centre by
One layer of nonmagnetic metal layer separates, and above-mentioned third magnetosphere can be CoFeB.
According to another aspect of the present invention, a kind of magnetic RAM is additionally provided, including above-mentioned magnetic tunnel junction.
Since the synthetic free layer includes the first magnetosphere that sequence is stacked, the second magnetosphere and graphene coating, graphene
Coating is located at side of first magnetosphere far from barrier layer, and the first magnetosphere has vertical magnetization side with the second magnetosphere
To there is graphene extra long distance to spin the spinning current transmission range (micron order) for dissipating overlength much larger than 10 in common metal
Nanometer scale also has lower resistivity, to provide the first perpendicular magnetic anisotropy in the first magnetosphere and potential barrier bed boundary
On the basis of, so that the second magnetosphere is formed the last the second perpendicular magnetic anisotropy with graphene coating, so that magnetic tunnel junction
It is still able to maintain excellent perpendicular magnetic anisotropy on the basis of total magnetic layer thickness is biggish, and then ensure that MRAM in small ruler
Data retention over time with higher still is able to when very little.
Magnetic tunnel junction provided by the invention is further illustrated below in conjunction with embodiment and comparative example.
Embodiment 1
Magnetic tunnel junction provided in this embodiment is as shown in Fig. 2, barrier layer 20 is MgO, one layer of deposition on barrier layer 20
CoFeB structure is as the first magnetosphere 310 in synthetic free layer 30, and thickness is between 1nm to 2.5nm；First is magnetic
One layer of Co of deposition is as the second magnetosphere 320 on layer 310, with a thickness of 0.5nm, deposits one layer of stone on the second magnetosphere 320
Black alkene is as graphene coating 330, with a thickness of 2nm.
Directly contact forms ferromagnetic coupling between Co and CoFeB；CoFeB | the interface MgO provides strong interface vertically respectively to different
Property, Co | graphene interface provides another strong interface perpendicular magnetic anisotropy；Two contribution superpositions, so that CoFeB | Co is magnetic easily
In vertically magnetizing, therefore, the introducing of graphene coating 330 makes 30 thickness of synthetic free layer reach 2nm or more still
Maintain effective perpendicular magnetic anisotropy energy, direction of magnetization vertical thin-film surface.
Embodiment 2
Magnetic tunnel junction provided in this embodiment is as shown in figure 3, barrier layer 20 is MgO, one layer of deposition on barrier layer 20
CoFeB structure is as the first magnetosphere 310 in synthetic free layer 30, and thickness is between 0.7nm to 2.5nm；First magnetic
Property layer 310 on one layer of nonmagnetic metal of deposition as the first non-magnetic metal layer 340, nonmagnetic metal can for Mo, Pt,
Ta, Ir, W, Pd and Ru etc., with a thickness of 0.2 between 1nm；One layer of Co, Ni or Fe are deposited on first non-magnetic metal layer 340
As the second magnetosphere 320,2nm is arrived with a thickness of 0.7；One layer of graphene is deposited on second magnetosphere 320 as graphene
Coating 330, with a thickness of 2nm.
The introducing of first non-magnetic metal layer 340, the second magnetosphere 320 and graphene coating 330, makes synthetic free layer
There are four film layer interfaces, the respectively interface MgO/CoFeB, CoFeB/ nonmagnetic metal interface, the nonmagnetic metal/interface Co for 30 tools
And Co/ graphite interface, each interface can form stronger perpendicular magnetic anisotropy, have entire free layer very strong
Perpendicular magnetic anisotropy surpasses so as to which MTJ size is accomplished 10nm hereinafter, greatly improving MRAM capacity in free layer thickness
Cross that 2nm or more is former so to keep good perpendicular magnetic anisotropy and thermal stability.
It can be seen from the above description that the above embodiments of the present invention realized the following chievements:
1, graphene coating is introduced, graphene has the spinning current transmission range (micron order) of overlength much larger than common
10 nanometer scales in metal also have lower resistivity, hang down to provide first in the first magnetosphere and potential barrier bed boundary
On the basis of straight anisotropy, the second magnetosphere is set to form the last the second perpendicular magnetic anisotropy with graphene coating, in turn
So that magnetic tunnel junction is still able to maintain excellent perpendicular magnetic anisotropy on the basis of total magnetic layer thickness is biggish；
2, the introducing of the first non-magnetic metal layer can make film layer interface there are four synthetic free layer tools, and each interface can
To form stronger perpendicular magnetic anisotropy, makes entire free layer that there is very strong perpendicular magnetic anisotropy, MTJ size can be done
To 10nm hereinafter, greatly improving MRAM capacity, being more than that 2nm or more is former in free layer thickness so keeps good vertical each
Anisotropy and thermal stability.
The foregoing is only a preferred embodiment of the present invention, is not intended to restrict the invention, for the skill of this field
For art personnel, the invention may be variously modified and varied.All within the spirits and principles of the present invention, made any to repair
Change, equivalent replacement, improvement etc., should all be included in the protection scope of the present invention.
Claims (10)
1. a kind of magnetic tunnel junction, which is characterized in that including be sequentially stacked magnetic fixing layer (10), barrier layer (20) and
Synthetic free layer (30), wherein the synthetic free layer (30) includes the first magnetosphere (310) for being stacked of sequence, and second
Magnetosphere (320) and graphene coating (330), it is remote that the graphene coating (330) is located at second magnetosphere (320)
Side from the barrier layer (20), and first magnetosphere (310) has vertical magnetic with second magnetosphere (320)
Change direction.
2. magnetic tunnel junction according to claim 1, which is characterized in that first magnetosphere (310) is magnetic with second
The sum of thickness of layer (320) is greater than 1.5nm.
3. magnetic tunnel junction according to claim 1 or 2, which is characterized in that the thickness of first magnetosphere (310) is big
In 0.7nm.
4. magnetic tunnel junction according to claim 1 or 2, which is characterized in that second magnetosphere (320) with a thickness of
0.2nm~1.5nm.
5. magnetic tunnel junction according to claim 1, which is characterized in that form the material of first magnetosphere (310)
For CoFeB or CoFe.
6. magnetic tunnel junction according to claim 1, which is characterized in that form the material of second magnetosphere (320)
Alloy selected from any one or more of composition of Co, Ni and Fe.
7. magnetic tunnel junction according to claim 1, which is characterized in that the magnetic tunnel junction further include be set to it is described
The first non-magnetic metal layer (340) between first magnetosphere (310) and second magnetosphere (320), preferably described first
Non-magnetic metal layer (340) with a thickness of 0.2nm~1nm.
8. magnetic tunnel junction according to claim 7, which is characterized in that form first non-magnetic metal layer (340)
Material be selected from any one of Mo, Pt, Ta, Ir, W, Pd and Ru.
9. magnetic tunnel junction according to claim 1, which is characterized in that the magnetism fixing layer (10) includes being stacked
Third magnetosphere, the second non-magnetic metal layer and artificial inverse ferric magnetosphere, and the artificial inverse ferric magnetosphere be located at it is described second non-
Side of the magnetic metallic layers far from the barrier layer (20).
10. a kind of magnetic RAM, including magnetic tunnel junction, which is characterized in that the magnetic tunnel becomes claim 1
To magnetic tunnel junction described in any one of 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810113910.9A CN110120452A (en) | 2018-02-05 | 2018-02-05 | Magnetic tunnel junction and magnetic RAM with it |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810113910.9A CN110120452A (en) | 2018-02-05 | 2018-02-05 | Magnetic tunnel junction and magnetic RAM with it |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110120452A true CN110120452A (en) | 2019-08-13 |
Family
ID=67519764
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810113910.9A Pending CN110120452A (en) | 2018-02-05 | 2018-02-05 | Magnetic tunnel junction and magnetic RAM with it |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110120452A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113725352A (en) * | 2021-07-16 | 2021-11-30 | 北京航空航天大学 | Magnetic tunnel junction film stack, magnetic memory and method for writing information |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20120205758A1 (en) * | 2011-02-11 | 2012-08-16 | Magic Technologies, Inc. | Magnetic element with improved out-of-plane anisotropy for spintronic applications |
| CN103907156A (en) * | 2011-09-22 | 2014-07-02 | 高通股份有限公司 | Thermally tolerant perpendicular magnetic anisotropy coupled elements for spin-transfer torque switching device |
| CN106663467A (en) * | 2014-07-01 | 2017-05-10 | 高通股份有限公司 | Synthetic antiferromagnet (SAF) coupled free layer for perpendicular magnetic tunnel junction (P-MTJ) |
-
2018
- 2018-02-05 CN CN201810113910.9A patent/CN110120452A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20120205758A1 (en) * | 2011-02-11 | 2012-08-16 | Magic Technologies, Inc. | Magnetic element with improved out-of-plane anisotropy for spintronic applications |
| CN103907156A (en) * | 2011-09-22 | 2014-07-02 | 高通股份有限公司 | Thermally tolerant perpendicular magnetic anisotropy coupled elements for spin-transfer torque switching device |
| CN106663467A (en) * | 2014-07-01 | 2017-05-10 | 高通股份有限公司 | Synthetic antiferromagnet (SAF) coupled free layer for perpendicular magnetic tunnel junction (P-MTJ) |
Non-Patent Citations (1)
| Title |
|---|
| HONGXIN YANG ET.AL: "Anatomy and Giant Enhancement of the Perpendicular Magnetic Anisotropy of Cobalt−Graphene Heterostructures", 《NANO LETTERS》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113725352A (en) * | 2021-07-16 | 2021-11-30 | 北京航空航天大学 | Magnetic tunnel junction film stack, magnetic memory and method for writing information |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108604632B (en) | Memory cell with magnetic tunnel junction and thermal stability enhancement layer | |
| EP2419933B1 (en) | Magnetic tunnel junction (mtj) and method for forming the same | |
| EP2523193B1 (en) | An improved high capacity low cost multi-state magnetic memory | |
| CN102176510B (en) | Magnetoresistance effect element and magnetoresistive random access memory using the same | |
| US7227773B1 (en) | Magnetic element utilizing spin-transfer and half-metals and an MRAM device using the magnetic element | |
| TWI556233B (en) | Method and system for providing hybrid magnetic tunneling junction elements with improved switching | |
| JP6038451B2 (en) | Method and system for providing a magnetic layer having an insertion layer for a spin transfer torque memory | |
| CN103151454B (en) | Memory element and storage device | |
| US6911710B2 (en) | Multi-bit magnetic memory cells | |
| US8710602B2 (en) | Method and system for providing magnetic junctions having improved characteristics | |
| CN107112415A (en) | Ultra thin vertical pinning Rotating fields for magnetic tunnel junction device | |
| US20130148418A1 (en) | Magnetoresistive device and a writing method for a magnetoresistive device | |
| CN104488102A (en) | Amorphous alloy spacer for perpendicular magnetic tunnel junction (MTJ)s | |
| WO2012128891A1 (en) | Magnetic tunnel junction with iron dusting layer between free layer and tunnel barrier | |
| CN103137855B (en) | Memory element and storage device | |
| US20130001717A1 (en) | Perpendicular mram with mtj including laminated magnetic layers | |
| WO2005048262A2 (en) | Mram architecture with a flux closed data storage layer | |
| CN103887425B (en) | Magnetic junction and magnetic memory and for providing the method for magnetic junction | |
| US20130108889A1 (en) | Magnetoresistance Device and Memory Device Including the Magnetoresistance Device | |
| JP7352930B2 (en) | Magnetic element, magnetic memory chip, magnetic storage device, and writing method for magnetic element | |
| US8565010B2 (en) | Magnetic random access memory with field compensating layer and multi-level cell | |
| CN110120452A (en) | Magnetic tunnel junction and magnetic RAM with it | |
| JP6342113B2 (en) | Method and system for providing a magnetic junction with improved characteristics | |
| WO2022087768A1 (en) | Magnetic tunnel junction, magnetoresistive random access memory, and electronic device | |
| WO2006129725A1 (en) | Mram |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20190813 |
|
| RJ01 | Rejection of invention patent application after publication |