JP2002042457A - Magnetic memory - Google Patents

Magnetic memory

Info

Publication number
JP2002042457A
JP2002042457A JP2000221409A JP2000221409A JP2002042457A JP 2002042457 A JP2002042457 A JP 2002042457A JP 2000221409 A JP2000221409 A JP 2000221409A JP 2000221409 A JP2000221409 A JP 2000221409A JP 2002042457 A JP2002042457 A JP 2002042457A
Authority
JP
Japan
Prior art keywords
magnetic
magnetic layer
information
magnetization
layer
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
Application number
JP2000221409A
Other languages
Japanese (ja)
Inventor
Makoto Mizukami
誠 水上
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Victor Company of Japan Ltd
Original Assignee
Victor Company of Japan Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Victor Company of Japan Ltd filed Critical Victor Company of Japan Ltd
Priority to JP2000221409A priority Critical patent/JP2002042457A/en
Publication of JP2002042457A publication Critical patent/JP2002042457A/en
Pending legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11CSTATIC STORES
    • G11C11/00Digital stores characterised by the use of particular electric or magnetic storage elements; Storage elements therefor
    • G11C11/56Digital stores characterised by the use of particular electric or magnetic storage elements; Storage elements therefor using storage elements with more than two stable states represented by steps, e.g. of voltage, current, phase, frequency
    • G11C11/5607Digital stores characterised by the use of particular electric or magnetic storage elements; Storage elements therefor using storage elements with more than two stable states represented by steps, e.g. of voltage, current, phase, frequency using magnetic storage elements
    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11CSTATIC STORES
    • G11C2211/00Indexing scheme relating to digital stores characterized by the use of particular electric or magnetic storage elements; Storage elements therefor
    • G11C2211/56Indexing scheme relating to G11C11/56 and sub-groups for features not covered by these groups
    • G11C2211/561Multilevel memory cell aspects
    • G11C2211/5615Multilevel magnetic memory cell using non-magnetic non-conducting interlayer, e.g. MTJ

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Hardware Design (AREA)
  • Mram Or Spin Memory Techniques (AREA)
  • Semiconductor Memories (AREA)
  • Hall/Mr Elements (AREA)

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic memory which is satisfactorily adaptive to high density by recording and reproducing multivalue information using a single memory cell. SOLUTION: Second magnetic layers 18 and 20 having higher coercive force Hc than a first magnetic layer 14 are provided. During an information recording, a ternary recording is conducted by the combination of the directions of magnetization of the layers 14, 18 and 20 (A to C). During an information reproducing, a pulse magnetic field which reverses its direction from the left to the right is applied to the magnetic memory by a word line 24 (D). The magnetic resistance condition varies in accordance with the magnetization directions of the layers 14, 18 and 20 (E to G), and thus logical values '0', '1' and '2' are discriminated.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【発明の属する技術分野】本発明は、磁気的に情報を記
憶する磁性メモリに関し、特にトンネル磁気抵抗効果を
利用した磁性メモリに関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic memory for magnetically storing information, and more particularly to a magnetic memory utilizing a tunnel magnetoresistance effect.

【0002】[0002]

【従来の技術】不揮発性メモリとしてフラッシュEEP
ROMなどがあるが、書き込み時間、読み出し時間の短
縮が重要な課題となっている。この課題に対して出力信
号が大きくとれ、高速読み出しが可能となる巨大磁気抵
抗効果を利用した磁性メモリが有効となる。この中でも
スピントンネル磁気抵抗効果を利用した磁性メモリは高
い磁気抵抗変化が得られることが知られている。
2. Description of the Related Art Flash EEP as a non-volatile memory
Although there are ROMs and the like, reduction of the writing time and the reading time is an important issue. To solve this problem, a magnetic memory utilizing a giant magnetoresistive effect capable of obtaining a large output signal and enabling high-speed reading becomes effective. Among them, it is known that a magnetic memory utilizing the spin tunnel magnetoresistance effect can obtain a high magnetoresistance change.

【0003】このスピントンネル磁気抵抗効果を利用し
た磁性メモリは、図3に示すように、保磁力(Hc)の
異なる2つの磁性膜を第一磁性層100/絶縁層102
/第二磁性層104の順に積層した構造となっている。
そして、このようなトンネル接合のトンネル抵抗が、両
磁性層の磁化方向の相対角度に依存して変化する現象を
利用してメモリ効果を得るようにしたものである。すな
わち、磁性層100,104の磁化が互いに逆方向を向
いているときは(反平行)トンネル抵抗は高くなり、磁
性層100,104の磁化が同一方向を向いているとき
は(平行)トンネル抵抗は小さくなる。
As shown in FIG. 3, a magnetic memory utilizing the spin tunneling magnetoresistance effect comprises two magnetic films having different coercive forces (Hc) formed of a first magnetic layer 100 / an insulating layer 102.
/ The second magnetic layer 104 is laminated in this order.
The memory effect is obtained by utilizing such a phenomenon that the tunnel resistance of the tunnel junction changes depending on the relative angle between the magnetization directions of the two magnetic layers. That is, when the magnetizations of the magnetic layers 100 and 104 are opposite to each other (antiparallel), the tunnel resistance is high, and when the magnetizations of the magnetic layers 100 and 104 are in the same direction, the (parallel) tunnel resistance is high. Becomes smaller.

【0004】例えば図3の例において、第一磁性層10
0を低保磁力とするとともに、第二磁性層104を高保
磁力とする。ワード線106に対する通電によって外部
磁界を発生させると、この外部磁界の方向によって両磁
性層100,104の磁化の方向が制御され、情報が記
録される。そして、同図に実線で示すように、ワード線
106による外部磁界によって両磁性層100,104
を右向きに磁化した場合を、情報の論理値「0」とす
る。逆に、同図に点線で示すように、ワード線106に
よる外部磁界によって両磁性層100,104を左向き
に磁化した場合を、情報の論理値「1」とする。
[0004] For example, in the example of FIG.
0 is a low coercive force, and the second magnetic layer 104 is a high coercive force. When an external magnetic field is generated by energizing the word line 106, the direction of the magnetization of the magnetic layers 100 and 104 is controlled by the direction of the external magnetic field, and information is recorded. Then, as shown by a solid line in FIG.
Is magnetized rightward, the logical value of the information is “0”. Conversely, as shown by the dotted line in FIG. 3, the case where both magnetic layers 100 and 104 are magnetized leftward by the external magnetic field generated by the word line 106 is defined as the logical value “1” of the information.

【0005】情報の再生は、低保磁力の第一磁性層10
0のみが磁化反転する程度の弱い再生用の磁界をワード
線106から発生させて行う。論理値「0」の情報が記
録されている場合(実線)には、右向き磁界(実線)を
印加しても変化は起こらない。しかし、論理値「1」の
情報が記録されている場合(点線)は、低保磁力の第一
磁性層100が右向き磁化反転を起こし、第一磁性層1
00と第二磁性層104の間で磁化の向きが逆方向とな
る。このため、磁気抵抗が高くなり、電流を印加してお
けば電圧変化として情報を読み出すことができる。こう
した原理で、情報の記録再生が行われる。
[0005] To reproduce information, the first magnetic layer 10 having a low coercive force is used.
This is performed by generating a weak read magnetic field from the word line 106 such that only 0 is the magnetization reversal. When the information of the logical value “0” is recorded (solid line), no change occurs even when a rightward magnetic field (solid line) is applied. However, when the information of the logical value “1” is recorded (dotted line), the first magnetic layer 100 having a low coercive force causes a rightward magnetization reversal, and the first magnetic layer 1
The direction of magnetization is opposite between 00 and the second magnetic layer 104. For this reason, the magnetoresistance increases, and information can be read as a voltage change if a current is applied. Recording and reproduction of information are performed based on such a principle.

【0006】[0006]

【発明が解決しようとする課題】しかしながら、以上の
ような従来技術には、一つのメモリセルで論理値の
「0」,「1」の2値,すなわち1ビットの情報しか記
録再生(書込み読出し)を行うことができない。今後の
高密度化の要求に応えるためには、メモリセル一つで1
ビットしか記録再生できないということでは不十分であ
る。本発明は、以上の点に着目したもので、一つのメモ
リセルで多値の情報の記録再生を行うことで、高密度化
に良好に対応することができる磁性メモリを提供するこ
とを、その目的とする。
However, in the above-described prior art, only one bit of information of two logical values "0" and "1", that is, information of one bit, is recorded / reproduced (written / read) in one memory cell. ) Can not do. To meet the demand for higher density in the future, one memory cell requires one
It is not enough that only bits can be recorded and reproduced. The present invention focuses on the above points, and provides a magnetic memory capable of coping with high density by performing recording and reproduction of multi-valued information in one memory cell. Aim.

【0007】[0007]

【課題を解決するための手段】前記目的を達成するた
め、本発明は、第一磁性層,絶縁層,第二磁性層の順に
積層されており、トンネル磁気抵抗効果を利用して情報
を記憶する磁性メモリであって、前記第二磁性層が、互
いに異なる保磁力を有する複数の領域を含むことを特徴
とする。主要な形態の一つによれば、前記第二磁性層の
保磁力が前記第一磁性層よりも大きいことを特徴とす
る。
According to the present invention, in order to achieve the above object, a first magnetic layer, an insulating layer, and a second magnetic layer are stacked in this order, and information is stored by utilizing a tunnel magnetoresistance effect. Wherein the second magnetic layer includes a plurality of regions having mutually different coercive forces. According to one of the main modes, a coercive force of the second magnetic layer is larger than that of the first magnetic layer.

【0008】[0008]

【発明の実施の形態】以下、本発明の実施の形態につい
て詳細に説明する。図1には、一実施形態の磁性メモリ
の構成が示されている。同図において、非磁性基板10
上には、まず電極12が形成される。この電極12上に
は、低保磁力の第一磁性層14,トンネル層16がその
順に積層形成され、このトンネル層16上に高保磁力の
第二磁性層18,20が形成されている。すなわち、こ
のように本実施形態では、第二磁性層が複数の領域に分
割形成されている。これら、磁性層14,18,20
は、それらの間で保磁力に差が生ずるように、例えばC
o基合金の組成や成膜条件を変化させることによってそ
れぞれ成膜されている。前記第二磁性層18,20上に
は、電極22が形成されている。更に、以上の積層体の
上部又は下部に、情報記録再生用のワード線24が配置
形成されている。
Embodiments of the present invention will be described below in detail. FIG. 1 shows a configuration of a magnetic memory according to one embodiment. In FIG.
First, the electrode 12 is formed. On the electrode 12, a first magnetic layer 14 having a low coercive force and a tunnel layer 16 are laminated in this order, and second magnetic layers 18 and 20 having a high coercive force are formed on the tunnel layer 16. That is, in this embodiment, the second magnetic layer is divided into a plurality of regions. These magnetic layers 14, 18, 20
Are, for example, C so that there is a difference in coercivity between them.
Films are formed by changing the composition of the o-based alloy and the film forming conditions. An electrode 22 is formed on the second magnetic layers 18 and 20. Further, a word line 24 for information recording / reproduction is arranged and formed on the upper or lower part of the above-mentioned laminate.

【0009】次に、図1に示した構成を持つ磁性メモリ
の製造過程について具体的に説明する。非磁性基板10
としては、例えばガラス基板を用いる。このガラス基板
上に、電極12として、例えば幅20μm,長さ100
μmの形状で、Crを0.02μm(200オングスト
ローム),次にCuを2μm,更にCrを0.02μm
(200オングストローム)の厚さにそれぞれ順に成膜
する。次に、この電極12上に、例えば幅20μm,長
さ40μmの形状で、第一磁性層14としてFeを0.
02μm(200オングストローム)の厚さに形成す
る。
Next, the manufacturing process of the magnetic memory having the configuration shown in FIG. 1 will be specifically described. Non-magnetic substrate 10
For example, a glass substrate is used. On this glass substrate, for example, a width of 20 μm and a length of 100
In a μm shape, Cr is 0.02 μm (200 Å), then Cu is 2 μm, and Cr is 0.02 μm.
(200 angstrom) in thickness. Next, on the electrode 12, for example, Fe having a width of 20 μm and a length of 40 μm was used as the first magnetic layer 14.
It is formed to a thickness of 02 μm (200 Å).

【0010】次に、この第一磁性層14上に、トンネル
層16としてAl23を厚さ0.002μm(20オン
グストローム)形成する。更に、このトンネル層16の
上に、例えば幅20μm,長さ20μmの形状で、第二
磁性層18としてFeCoを0.02μm(200オン
グストローム)の厚さに形成する。また、この第二磁性
層18の隣に、例えば幅20μm,長さ20μmの形状
で、第二磁性層20としてCoを0.02μm(200
オングストローム)の厚さに形成する。最後に、これら
第二磁性層18,20上に、電極22として、例えば幅
40μm,長さ100μmの形状で、Crを0.02μ
m(200オングストローム),Cuを2μm,更にC
rを0.02μm(200オングストローム)の厚さに
それぞれ順に積層する。このようにして、前記図1に示
した磁性メモリを得る。
Next, on the first magnetic layer 14, Al 2 O 3 is formed as a tunnel layer 16 to a thickness of 0.002 μm (20 angstroms). Further, on the tunnel layer 16, for example, FeCo is formed as a second magnetic layer 18 to have a thickness of 0.02 μm (200 Å) in a shape having a width of 20 μm and a length of 20 μm. Further, next to the second magnetic layer 18, for example, Co having a width of 20 μm and a length of 20 μm is formed of 0.02 μm (200 μm) as the second magnetic layer 20.
Angstroms). Finally, on the second magnetic layers 18 and 20, as the electrode 22, for example, a Cr having a width of 40 μm and a length of 100 μm is formed by adding 0.02 μm of Cr.
m (200 Å), Cu 2 μm, and C
r are sequentially laminated to a thickness of 0.02 μm (200 Å). Thus, the magnetic memory shown in FIG. 1 is obtained.

【0011】以上のようにして作製した磁性メモリは、
第一磁性層14の保磁力Hcが15(Oe)であり、第
二磁性層18の保磁力Hcが70(Oe)であり、第二
磁性層20の保磁力Hcが120(Oe)である。
The magnetic memory manufactured as described above is
The coercive force Hc of the first magnetic layer 14 is 15 (Oe), the coercive force Hc of the second magnetic layer 18 is 70 (Oe), and the coercive force Hc of the second magnetic layer 20 is 120 (Oe). .

【0012】次に、以上のように構成された実施形態の
作用を、図2も参照しながら説明する。まず、情報記録
時の作用から説明する。ワード線24に電流を流すと、
その電流に応じた磁界が周囲に発生する。ワード線24
に十分大きな電流を流し、右方向に全磁性層が飽和する
磁界(例えば150(Oe))を形成すると、図2
(A)に示すように、第一磁性層14,第二磁性層18
及び20は、全て右向きに磁化した状態となる。この状
態を論理値の「0」とする。この状態から左向きに磁界
を印加し、第二磁性層18の保磁力70(Oe)を越え
た値である80(Oe)となると、図2(B)に示すよ
うに、第一磁性層14と第二磁性層18が左向きに磁化
反転しており、第二磁性層20が右向きのままの状態と
なる。この状態を論理値の「1」とする。更に、左向き
に磁界を強め、第二磁性層20の保磁力120(Oe)
を越えた値である150(Oe)とすると、図2(C)
に示すように磁化は全て左向きとなる。この状態を論理
値の「2」とする。このようにして、3値記録が行われ
る。これらの3値の状態は、磁界を取り去った後もその
まま維持される。
Next, the operation of the embodiment configured as described above will be described with reference to FIG. First, the operation at the time of recording information will be described. When a current flows through the word line 24,
A magnetic field corresponding to the current is generated around. Word line 24
When a sufficiently large current is passed to generate a magnetic field (e.g., 150 (Oe)) that saturates the entire magnetic layer in the right direction, FIG.
As shown in (A), the first magnetic layer 14 and the second magnetic layer 18
And 20 are all magnetized rightward. This state is defined as a logical value “0”. From this state, a magnetic field is applied leftward, and when the coercive force of the second magnetic layer 18 becomes 80 (Oe), which exceeds the coercive force 70 (Oe), as shown in FIG. And the second magnetic layer 18 is reversing magnetization leftward, and the second magnetic layer 20 remains rightward. This state is defined as a logical value “1”. Further, the magnetic field is strengthened leftward, and the coercive force 120 (Oe) of the second magnetic layer 20 is increased.
Assuming that the value exceeds 150 (Oe), FIG.
As shown in the figure, the magnetizations are all directed leftward. This state is defined as a logical value “2”. In this way, ternary recording is performed. These ternary states are maintained even after the magnetic field is removed.

【0013】記録情報の論理値と各磁性層の磁化の向き
の関係を示すと、次の表1に示すようになる。
The relationship between the logical value of the recorded information and the direction of the magnetization of each magnetic layer is shown in Table 1 below.

【表1】 [Table 1]

【0014】次に、情報再生の作用について説明する。
記録されている情報を再生するときは、第一磁性層14
のみが磁化反転する程度の弱い再生用の磁界を、ワード
線24によって発生させる。具体的には、図2(D)に
示すように、ワード線24によって左向きから右向きへ
方向反転するパルス磁界を形成し、これを各磁性層1
4,18,20に印加する。
Next, the operation of information reproduction will be described.
When reproducing the recorded information, the first magnetic layer 14
The word line 24 generates a reproducing magnetic field weak enough to cause only the magnetization reversal. Specifically, as shown in FIG. 2D, a pulse magnetic field that reverses direction from left to right is formed by the word line 24, and this is applied to each magnetic layer 1.
4, 18, and 20.

【0015】まず、論理値「0」の情報が記録されてい
る場合、前記図2(A)及び前記表1に示したように、
磁性層14,18,20の磁化方向は全て右向きであ
る。この状態で、ワード線24から左向きのパルス磁界
が印加されると、該パルス磁界の強さは第一磁性層14
のみを磁化反転させることができる程度なので、第一磁
性層14の磁化方向のみが反転する。このため、第一磁
性層14と第二磁性層18,20の磁化の向きが互いに
逆向きとなり、磁気抵抗効果が生じて、メモリ素子の磁
気抵抗は高くなる。その後、印加パルス磁界が右向きと
なると(図2(D)参照)、第一磁性層14の磁化方向
が反転して再び右向きになり、第一磁性層14と第二磁
性層18,20の磁化の向きが同じ右向きとなり、その
抵抗値は低下する。つまり、磁気抵抗は、図2(E)に
示すようにパルス状に変化する。
First, when the information of the logical value "0" is recorded, as shown in FIG.
The magnetization directions of the magnetic layers 14, 18, and 20 are all rightward. In this state, when a leftward pulsed magnetic field is applied from the word line 24, the intensity of the pulsed magnetic field becomes
Only the magnetization direction of the first magnetic layer 14 is reversed because only the magnetization direction can be reversed. Therefore, the magnetization directions of the first magnetic layer 14 and the second magnetic layers 18 and 20 are opposite to each other, and a magnetoresistive effect occurs, and the magnetoresistance of the memory element increases. Thereafter, when the applied pulse magnetic field becomes rightward (see FIG. 2D), the magnetization direction of the first magnetic layer 14 is reversed and becomes rightward again, and the magnetization of the first magnetic layer 14 and the second magnetic layers 18 and 20 is changed. Becomes the same right direction, and the resistance value decreases. That is, the magnetic resistance changes in a pulse shape as shown in FIG.

【0016】次に、論理値「1」の情報が記録されてい
る場合、前記図2(B)及び前記表1に示したように、
第一磁性層14と第二磁性層20の磁化の向きが反対で
ある。このため、図2(D)に示す左向きのパルス磁界
が印加されると、第一磁性層14は左向きのままで、素
子の抵抗値が高い状態がそのまま維持される。そして、
パルス磁界が右方向に反転した瞬間に、第一磁性層14
の磁化方向が反転して右向きとなり、抵抗値は変化を起
こす。この変化は、第一磁性層14と第二磁性層20の
トンネル抵抗変化量が第一磁性層14と第二磁性層18
のトンネル磁性層変化量より大きければ抵抗値が高くな
るし、逆に小さければ抵抗値は低くなる。図2(B)は
抵抗値が小さくなる例である。従って、磁気抵抗は、図
2(F)に示すように変化する。
Next, when the information of the logical value "1" is recorded, as shown in FIG.
The magnetization directions of the first magnetic layer 14 and the second magnetic layer 20 are opposite. Therefore, when the leftward pulse magnetic field shown in FIG. 2D is applied, the first magnetic layer 14 remains leftward, and the state where the resistance value of the element is high is maintained as it is. And
At the moment when the pulse magnetic field is reversed to the right, the first magnetic layer 14
Is reversed to the right, and the resistance value changes. This change is caused by the change in tunnel resistance between the first magnetic layer 14 and the second magnetic layer 20.
If the change amount is larger than the change amount of the tunnel magnetic layer, the resistance value increases, and if the change amount is smaller, the resistance value decreases. FIG. 2B is an example in which the resistance value decreases. Therefore, the magnetic resistance changes as shown in FIG.

【0017】次に、論理値「2」の情報が記録されてい
る場合、前記図2(C)及び前記表1に示すように、磁
性層14,18,20の全てが左向きであって、抵抗値
が小さくなっている。この状態で同様に図2(D)のパ
ルス磁界が印加されると、右向きの磁界がかかった瞬間
に、第一磁性層14の磁化方向が反転して右向きとな
る。このため、第一磁性層14と、第二磁性層18,2
0の磁化の向きと互いに逆向きとなり、図2(G)に示
すように、磁気抵抗効果が生じて抵抗値が高くなる。
Next, when the information of the logical value "2" is recorded, as shown in FIG. 2C and Table 1, all of the magnetic layers 14, 18, and 20 are directed to the left. Resistance value is low. When the pulse magnetic field of FIG. 2D is similarly applied in this state, the moment the rightward magnetic field is applied, the magnetization direction of the first magnetic layer 14 is reversed and becomes rightward. For this reason, the first magnetic layer 14 and the second magnetic layers 18 and 2
The direction of magnetization is opposite to the direction of magnetization 0, and as shown in FIG. 2 (G), a magnetoresistance effect occurs and the resistance value increases.

【0018】以上のように記録時の各磁性層の磁化状態
によって再生時の抵抗値が変化する。このため、該抵抗
値の変化に基づいて記録状態を判別することが可能とな
る。つまり、パルス磁界を印加するときに生ずる磁性メ
モリの抵抗値の変化によって、各磁性層の磁化方向に対
応させた情報の論理値「0」,「1」,「2」を判別す
ることができ、3値の記録再生を実現することができ
る。
As described above, the resistance value during reproduction changes according to the magnetization state of each magnetic layer during recording. Therefore, it is possible to determine the recording state based on the change in the resistance value. That is, the logical values “0”, “1”, and “2” of the information corresponding to the magnetization direction of each magnetic layer can be determined based on the change in the resistance value of the magnetic memory caused when the pulse magnetic field is applied. And ternary recording / reproduction can be realized.

【0019】なお、本実施形態では3値情報の記録再生
を行う場合を例として説明したが、それに限定されるも
のではなく、第二磁性層を更に多数の領域に分割すると
ともに、各分割領域の保磁力Hcを独立した異なる値に
設定すれば、3値以上の多値化情報の記録再生も可能で
ある。また、各部の材料や膜厚など、上述した作用を奏
するように適宜設定してよい。また、各磁性層の磁化の
方向も一例であり、何ら上記実施形態に限定されるもの
ではない。
In this embodiment, the case where recording and reproduction of ternary information is performed has been described as an example. However, the present invention is not limited to this. If the coercive force Hc is set to different and independent values, it is possible to record and reproduce multi-valued information of three or more values. Further, the material and film thickness of each part may be appropriately set so as to exert the above-described effects. Further, the direction of magnetization of each magnetic layer is also an example, and is not limited to the above embodiment.

【0020】[0020]

【発明の効果】以上説明したように、本発明によれば、
第二磁性層を、互いに異なる保磁力を有する複数の領域
に分割することとしたので、一つのメモリセルで2値以
上の多値の情報の記録再生が可能となり、将来の情報の
高密度化に良好に対応できるという効果がある。
As described above, according to the present invention,
Since the second magnetic layer is divided into a plurality of regions having different coercive forces, it is possible to record and reproduce binary or multi-level information with one memory cell, and to increase the density of future information. Has the effect of being able to respond favorably.

【図面の簡単な説明】[Brief description of the drawings]

【図1】本発明の一実施形態の磁性メモリの積層構造を
示す図である。
FIG. 1 is a diagram showing a laminated structure of a magnetic memory according to an embodiment of the present invention.

【図2】前記実施形態における情報の記録再生の様子を
示す図である。
FIG. 2 is a diagram showing how information is recorded and reproduced in the embodiment.

【図3】磁性メモリに対する2値情報の記録再生の様子
を示す図である。
FIG. 3 is a diagram showing a state of recording and reproducing binary information with respect to a magnetic memory;

【符号の説明】[Explanation of symbols]

10…非磁性基板 12,22…電極 14…第一磁性層 16…トンネル層 18,20…第二磁性層 24…ワード線 DESCRIPTION OF SYMBOLS 10 ... Non-magnetic substrate 12, 22 ... Electrode 14 ... First magnetic layer 16 ... Tunnel layer 18, 20 ... Second magnetic layer 24 ... Word line

Claims (2)

【特許請求の範囲】[Claims] 【請求項1】 第一磁性層,絶縁層,第二磁性層の順に
積層されており、トンネル磁気抵抗効果を利用して情報
を記憶する磁性メモリであって、 前記第二磁性層が、互いに異なる保磁力を有する複数の
領域を含むことを特徴とする磁性メモリ。
1. A magnetic memory which stores information using a tunnel magnetoresistive effect and is laminated in the order of a first magnetic layer, an insulating layer, and a second magnetic layer, wherein the second magnetic layers are mutually stacked. A magnetic memory comprising a plurality of regions having different coercive forces.
【請求項2】 前記第二磁性層の保磁力が前記第一磁性
層よりも大きいことを特徴とする請求項1記載の磁性メ
モリ。
2. The magnetic memory according to claim 1, wherein the coercive force of the second magnetic layer is larger than that of the first magnetic layer.
JP2000221409A 2000-07-21 2000-07-21 Magnetic memory Pending JP2002042457A (en)

Priority Applications (1)

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Publication Number Publication Date
JP2002042457A true JP2002042457A (en) 2002-02-08

Family

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Family Applications (1)

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Country Status (1)

Country Link
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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004319786A (en) * 2003-04-16 2004-11-11 Sony Corp Magnetic storage element
WO2006000696A1 (en) * 2004-06-03 2006-01-05 Spintron Magnetic memory comprising several magnetizing modules
JP2007281334A (en) * 2006-04-11 2007-10-25 Fuji Electric Holdings Co Ltd Spin injection magnetism inverting element and its manufacturing method, and magnetic recording device using same
JP2012104818A (en) * 2010-11-11 2012-05-31 Seagate Technology Llc Memory cell, and method of operating memory cell
DE102012201789B4 (en) 2011-02-07 2018-07-12 Globalfoundries Inc. Non-volatile CMOS-compatible logic circuits and associated operating methods

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004319786A (en) * 2003-04-16 2004-11-11 Sony Corp Magnetic storage element
JP4543619B2 (en) * 2003-04-16 2010-09-15 ソニー株式会社 Magnetic memory element
WO2006000696A1 (en) * 2004-06-03 2006-01-05 Spintron Magnetic memory comprising several magnetizing modules
JP2007281334A (en) * 2006-04-11 2007-10-25 Fuji Electric Holdings Co Ltd Spin injection magnetism inverting element and its manufacturing method, and magnetic recording device using same
JP2012104818A (en) * 2010-11-11 2012-05-31 Seagate Technology Llc Memory cell, and method of operating memory cell
CN102543180A (en) * 2010-11-11 2012-07-04 希捷科技有限公司 Multi-bit magnetic memory with independently programmable free layer domains
DE102012201789B4 (en) 2011-02-07 2018-07-12 Globalfoundries Inc. Non-volatile CMOS-compatible logic circuits and associated operating methods

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