JP2003163330A - Magnetic memory - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive, solid magnetic memory having an ultra large capacity that can eliminate erroneous operation due to an interlayer cross-talk and at the same time can be integrated highly. <P>SOLUTION: The magnetic memory comprises a first magnetoresistive effect element (C2), first wiring (W1) extended onto it, a second magnetoresistive effect element (C1) that is provided on it, and second wiring (B1) extended in a direction for crossing the first wiring on it. The first and second magnetoresistive effect elements have a magnetic recording layer having nearly the same magnetization anisotropy. Then, at least one portion of the magnetized direction of the magnetic recording layers is inclined in a direction that is not parallel and not vertical to at least either of the first and second wires. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic memory, and more particularly, it has a structure in which memory arrays having a magnetoresistive effect element such as a ferromagnetic tunnel junction type are laminated, The present invention relates to a magnetic memory that suppresses write crosstalk.

[0002]

2. Description of the Related Art A magnetoresistive element using a magnetic film is
In addition to being used in magnetic heads and magnetic sensors, solid-state magnetic memory (magnetoresistive memory: MRAM
(Magnetic Random Access Memory)) has been proposed.

In recent years, in a sandwich structure film in which a single dielectric layer is inserted between two magnetic metal layers, a so-called "magnetoresistance effect element" is used as a magnetoresistive effect element in which a current is passed perpendicularly to the film surface and a tunnel current is used. "Tunneling Magneto-Resistance effect (TMR element)" has been proposed. In a ferromagnetic tunnel junction device, a magnetoresistance change rate of 20% or more has been obtained (J. Appl. Phys. 79, 4724 (1996)).
The possibility of application to MRAM has increased.

In this ferromagnetic tunnel junction element, a thin Al (aluminum) layer having a thickness of 0.6 nm to 2.0 nm is formed on a ferromagnetic electrode, and then the surface thereof is exposed to oxygen glow discharge or oxygen gas. , Al ₂ O ₃ to form a tunnel barrier layer.

Further, there has been proposed a ferromagnetic single tunnel junction having a structure in which an antiferromagnetic layer is provided on one ferromagnetic layer on one side of the ferromagnetic single tunnel junction, and one has a fixed magnetization layer ( JP-A-10-4227).

Further, a ferromagnetic tunnel junction through magnetic particles dispersed in a dielectric and a ferromagnetic double tunnel junction (continuous film) have been proposed (Phys. Rev. B56 (10), R5747 (1).
997), Journal of Applied Magnetics 23,4-2, (1999), Appl. Phys. Le
tt. 73 (19), 2829 (1998), Jpn. J. Appl. Phys. 39, L10
35 (2001)).

Also in these cases, the magnetoresistance change rate of 20 to 50% is obtained, and even if the voltage value applied to the ferromagnetic tunnel junction element is increased to obtain a desired output voltage value, the magnetic resistance is increased. Since the decrease in the rate of change in resistance is suppressed, there is a possibility of application to MRAM.

The magnetic recording element using the ferromagnetic single tunnel junction or the ferromagnetic double tunnel junction is non-volatile, and the writing / reading time is as short as 10 nanoseconds or less.
The number of rewrites has a potential of 10 ¹⁵ or more. In particular, in the magnetic recording element using the ferromagnetic double tunnel junction, as described above, even if the voltage value applied to the ferromagnetic tunnel junction element is increased to obtain the desired output voltage value, the magnetoresistance change rate decreases. Since it is suppressed, a large output voltage can be obtained, and the magnetic recording element exhibits favorable characteristics.

However, regarding the cell size of the memory,
When the 1Tr (transistor) -1TMR architecture (for example, disclosed in USP 5,734,605) is used, a semiconductor DRAM (Dynamic Random) is used.
There is a problem that the size cannot be reduced below Access Memory).

To solve this problem, the bit (bi
Diode type architecture (US) in which a TMR cell and a diode are connected in series between a t) line and a word line.
P5,640,343) or a simple matrix type architecture in which TMR cells are arranged between bit lines and word lines (DE 19744095, WO 99147).
60) is proposed.

Further, in these architectures, there is a problem of mutual interference between adjacent TMR cells at the time of writing. To solve this problem, TMR
There has been proposed a structure in which cells are arranged in parallelograms and arranged in such a manner that a major axis direction is alternately different between adjacent cells like a chessboard pattern (USP 6,005,800).

However, in order to increase the capacity of the magnetic memory, it is desirable to stack the memory arrays in layers in the vertical direction. In order to realize such a laminated structure, a structure that prevents crosstalk that occurs in the laminating direction during writing is required.

[0013]

As described above,
In order to make the MRAM larger in capacity than the semiconductor DRAM, it is not preferable to use the conventional 1Tr-1TMR architecture. That is, in order to realize an ultra-large capacity MRAM, a multi-layer architecture in which memory arrays are stacked by using an architecture in which the memory arrays can be stacked is desirable. However, in that case, there are further problems such as cell structure and crosstalk in the stacking direction.

The present invention has been made on the basis of the recognition of such a problem, and an object thereof is to provide an ultra-large-capacity solid-state magnetic memory which can be highly integrated while eliminating malfunction due to crosstalk between layers and is inexpensive. To provide.

In order to achieve the above object, a magnetic memory of the present invention comprises a first magnetoresistive effect element and a first magnetoresistive effect element extending over the first magnetoresistive effect element.
Wiring, a second magnetoresistive effect element provided on the first wiring, and a second magnetoresistive effect element extending on the second magnetoresistive effect element in a direction crossing the first wiring. Two wirings, and the first and second magnetoresistive effect elements each have a magnetic recording layer having magnetization anisotropy in substantially the same direction,
The magnetization of the magnetic recording layer of the second magnetoresistive effect element can be reversed by a magnetic field formed by passing a current through the first and second wirings, and the first and second magnetoresistive effects can be obtained. At least part of the magnetization direction of the magnetic recording layer of the element is inclined with respect to at least one of the first and second wirings.

According to the above structure, the action of the write magnetic field obtained by passing a current through the first wiring and the second wiring causes the first magnetoresistive effect element and the second magnetoresistive effect element to operate. It acts differently. As a result,
Write crosstalk between the upper and lower magnetoresistive elements can be eliminated.

In the present specification, the "intersecting direction" does not mean a state in which the first wiring and the second wiring intersect at one point, but they are in a twisted position, The state where they intersect when projected onto the film surface of the magnetoresistive effect element.

A second magnetic memory according to the present invention is a first memory array having a plurality of magnetoresistive elements arranged in a matrix, and a first memory array laminated on the first memory array to form a matrix. A second memory array having a plurality of magnetoresistive effect elements arranged in the first and second memory arrays, wherein each of the first and second memory arrays has a first memory element extending below the magnetoresistive effect element. And a second wiring extending in a direction intersecting the first wiring on the magnetoresistive effect element are provided, and by applying a current to the first and second wirings, The magnetic field formed allows the magnetization of the magnetic recording layers of the magnetoresistive effect element disposed between them to be reversible, and the magnetic recording layer of the magnetoresistive effect element in the first and second memory arrays is substantially Same direction Has a reduction anisotropy, at least part of the magnetization direction of the magnetic recording layer is characterized by being inclined with respect to at least one of said first and second wiring.

Also according to the above structure, the action of the write magnetic field obtained by passing a current through the first wiring and the second wiring acts on the first magnetoresistive effect element and the second magnetoresistive effect element. Acts differently. As a result, write crosstalk between the upper and lower magnetoresistive elements can be eliminated.

Further, in the above magnetic memory,
By making the second wiring provided in the first memory array and the first wiring provided in the second memory array in common, write crosstalk is prevented. The structure can be simplified while suppressing, and a higher degree of integration can be obtained.

In each of the first and second memory arrays, the plurality of magnetoresistive effect elements arranged in the matrix form have a magnetoresistive effect element having a magnetic recording layer formed in the first shape. And a magnetoresistive effect element having a magnetic recording layer formed in a second shape different from the first shape are alternately arranged, write crosstalk in the same memory array. Can be effectively suppressed.

Further, if the magnetic recording layer is formed asymmetrically with respect to the major axis of at least one of the first and second wirings, at least a part of the magnetization direction thereof is the above-mentioned. It can be tilted in a direction that is neither parallel nor perpendicular to at least one of the first and second wirings.

Alternatively, if the angle at which the first wiring and the second wiring intersect is other than 90 degrees,
At least a part of the magnetization direction of the magnetic recording layer can be inclined in a direction that is neither parallel nor perpendicular to at least one of the first and second wirings.

In the present specification, "the angle at which the first wiring and the second wiring intersect" means that the first wiring and the second wiring are with respect to the film surface of the magnetoresistive effect element. The intersection angle when projected.

The ratio L / D of the width D to the length L of the magnetic recording layer is larger than 1.2 and the length L thereof is L.
If uniaxial anisotropy along the direction of is given, a magnetic recording layer having stable magnetization anisotropy is obtained,
Writing and reading can be surely performed.

Further, if at least one of the first and second wirings has a coating layer made of a soft magnetic material on its side surface, the write magnetic field is prevented from leaking to the magnetoresistive element adjacent to the periphery. By suppressing the write crosstalk, the write crosstalk can be suppressed more effectively. A third magnetic memory of the present invention is a first memory array having a plurality of magnetoresistive elements arranged in a matrix, and is stacked on the first memory array and arranged in a matrix. A second memory array having a plurality of magnetoresistive effect elements, and each of the first and second memory arrays has a first wiring extending below the magnetoresistive effect element. A second wiring extending in a direction intersecting with the first wiring is provided on the magnetoresistive effect element, and is formed by applying a current to the first and second wirings. The magnetization of the magnetic recording layer of the magnetoresistive effect element arranged between them can be reversed by a magnetic field, and the second wiring provided in the first memory array and the second memory array are provided. Provided the first And lines, it is common, and wherein the coating layer made of a soft magnetic material on its side is provided. According to the above configuration, when writing is performed using the wiring common to the upper and lower memory arrays, the current magnetic field can be uniformly applied to the upper and lower magnetoresistive elements, and at the same time, these Crosstalk at the time of writing to the magnetoresistive effect elements adjacent to the upper and lower magnetoresistive effect elements can be effectively suppressed, which is an extremely advantageous configuration in the architecture of the multilayer structure.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic view showing a unit cell of a magnetic memory of the present invention in a simplified manner. FIG. 1 (a) shows its planar structure and FIG. 1 (b) shows its sectional structure.

First, looking at the plane configuration, as shown in FIG. 3A, the bit lines B and the word lines W are wired so as to intersect, and the magnetoresistive effect element C is provided at the intersection. ing. Then, as illustrated in FIG. 1B, such cell structures are vertically stacked.

As will be described in detail later, the bit lines B (B1 ...
Regarding B3), the connection relationship between the word lines W (W1, W2) and the magnetoresistive effect elements C (C1 to C4), various specific examples can be adopted. For example, two bit lines for writing and reading may be provided and connected to the magnetoresistive effect element. The word line may or may not be connected to the magnetoresistive effect element.

The magnetoresistive effect element C (C1 to C4) has a magnetic recording layer such as a TMR element. This magnetic recording layer has magnetization directions M1 and M2 that are substantially anti-parallel to each other. By associating these two types of magnetization directions with data of "0" and "1", recording and reading of binarized information are performed. Is possible. Note that these magnetization directions M1 and M2
As will be described later in detail, the edge domain is not necessarily linear and forms a different edge domain depending on the shape of the magnetoresistive effect element C.

Writing of information to the magnetoresistive effect element C (C1 to C4) is performed by the bit line B provided above and below the bit line B.
(B1 to B3) and the word line W (W1, W2) is performed by a magnetic field generated by passing a current. For example, when a current is applied to each of the bit line B1 and the word line W1, a current magnetic field is generated around them. The magnetic field obtained by combining these current magnetic fields reverses the magnetization of the magnetic recording layer of the magnetoresistive effect element C1 from M1 to M2 or from M2 to M1. In this way, the binarized information can be written.

At the time of this writing, in order to reverse the magnetization in a predetermined direction, a current pulse in a predetermined direction may be appropriately applied to both the bit line B and the word line W. By doing so, the amount of current per wire can be reduced and the cell can be selected as compared with the case where the magnetization reversal is caused by passing the current through only one of the bit line and the word line. . As a result, it is possible to provide a highly reliable magnetic memory with less wiring fatigue.

Further, as shown in FIG. 1B, by stacking the cell structures of the magnetic memory in the vertical direction, the degree of integration can be increased and a semiconductor DRAM or higher integration can be realized. You can

However, as can be seen from FIG. 1B, the magnetoresistive effect element C1 is formed above and below the word line W1 with the word line W1 interposed therebetween.
When C2 is laminated, so-called "write crosstalk" may occur between these magnetoresistive effect elements. For example, when writing is performed on the magnetoresistive effect element C1 by passing a current through the bit line B1 and the word line W1, the write magnetic field is also applied to the magnetoresistive effect element C2 adjacent to the lower side, and the recording is performed. The magnetization may be reversed.

On the other hand, according to the present invention, FIG.
As illustrated in (a), the magnetoresistive effect elements C1 and C2
The magnetic easy axis direction (M1, M2) of the magnetic recording layer is not parallel or perpendicular to at least one of the bit line and the word line. That is, the magnetization direction is inclined with respect to at least one of the bit line and the word line. At that time, C1 and C2 are inclined in the same direction.

By doing so, it is possible to prevent write crosstalk between the magnetoresistive effect elements C1 and C2 which are vertically stacked with the word line W1 interposed therebetween as illustrated in FIG. 1B.

2 and 3 are conceptual diagrams for explaining the operation of the present invention. That is, FIG. 2 is a schematic diagram showing a comparative example to which the present invention is not applied, and FIG. 3 is a schematic diagram illustrating the operation of a specific example of the present invention.

First, a comparative example will be described with reference to FIG. As shown in FIG. 2A, the direction of the magnetization M of the magnetic recording layer of the magnetoresistive effect element (MR element) is aligned in the direction parallel or perpendicular to both the bit line B and the word line W. In this case, the asteroid curve of the magnetic field required for reversing the magnetization M is as shown in FIG. Here, when the combined magnetic field Ht1 of the magnetic field Hb1 generated by applying the write current to the bit line B1 and the magnetic field Hw1 generated by applying the write current to the word line W1 exceeds the asteroid curve, the magnetoresistive effect is obtained. It is possible to reverse the magnetization M of the element.

However, in the case of the specific example shown in FIG. 2, the asteroid curve is formed line-symmetrically with respect to the bit line B1 and the word line W1. Therefore, when the magnetoresistive effect elements C1 and C2 are stacked above and below the word line W1 as illustrated in FIG. 1B, the write magnetic fields from the bit line B1 and the word line W1 generate the magnetoresistive effect elements. Equivalently acts on C1 and C2.

That is, a current is passed through the word line W1,
Magnetic field Hw1 applied to the upper magnetoresistive effect element C1
And the magnetic field H applied to the lower magnetoresistive element C2
It is opposite in direction to w2, but acts equivalently on the asteroid curve. Therefore, the magnetic field Hb1 from the bit line necessary for the magnetization reversal to occur in the upper magnetoresistive effect element C1 and the magnetic field Hb2 from the bit line necessary to cause the magnetization reversal in the lower magnetoresistive effect element C2. Are the same. As a result, when writing to the magnetoresistive effect element C1 on the upper side, there is generally a variation in the switching magnetic field of the element, so that there is a possibility that write crosstalk occurs on the magnetoresistive effect element C2 on the lower side. .

On the other hand, in the present invention, for example, as shown in FIG. 3A, the direction of the magnetization M is inclined with respect to the bit line B (or the word line W). In this case, the asteroid curve is formed to be inclined as shown in FIG. With this configuration, the magnetic field H applied to the magnetoresistive effect elements C1 and C2 above and below the word line W
w1 and the magnetic field Hw2 have the same magnitude in opposite directions,
A difference occurs in the magnetic field from the bit line required for the magnetization reversal, and the margin increases.

That is, the magnetic field Hb from the bit line necessary for reversing the magnetization of the upper magnetoresistive element C1.
In contrast to 1, the magnetic field Hb2 from the bit line required to reverse the magnetization of the lower magnetoresistive effect element C2 becomes large. As a result, the upper magnetoresistive element C1
Of the lower magnetoresistive effect element C2 when writing
The magnetization of is not reversed, and write crosstalk can be eliminated.

The same effect can be obtained when writing is performed on the lower magnetoresistive effect element C2. That is, when writing is performed in the lower magnetoresistive effect element C2, the magnetization reversal does not occur in the upper magnetoresistive effect element C1 in the write magnetic field, so that the write crosstalk can be eliminated.

At the time of writing these, in order to rotate and invert the magnetization in an advantageous direction in consideration of the inclination direction of the magnetization of the target magnetoresistive effect element, the current pulse applied to both the bit line and the word line is applied. The direction may be switched appropriately.

In the specific example shown in FIG. 3, the plane form of the magnetic recording layer of the magnetoresistive effect elements C1 and C2 is shown as a rectangle inclined with respect to the bit line B. It is not limited to

FIG. 4 is a schematic view showing another specific example of the plane form of the magnetic recording layer of the magnetoresistive effect element according to the present invention. That is, the magnetic recording layer of the magnetoresistive effect element has, for example, a shape in which a protrusion is added to one diagonal end of a rectangle as shown in FIG. A parallelogram, a rhombus as shown in FIG. 3C, an ellipse as shown in FIG. 3D, an edge-pointed type as shown in FIG. 2E, that is, both ends are tapered. It can have various shapes such as a curved shape.

Here, the magnetic recording layer is formed as shown in FIGS.
Alternatively, when patterning into the shape shown in (e),
In many cases, the corners are actually rounded, but the corners may be rounded as such.

Further, these asymmetrical shapes can be easily produced by making the pattern shape of the reticle used in photolithography asymmetrical. For example,
The magnetoresistive effect element having the shape illustrated in FIG. 4A can be manufactured by setting the pattern shape of the reticle as shown in FIG.

None of the shapes illustrated in FIG. 4 are line-symmetric with respect to the long axis of the bit line B. With such a shape, at least a part of the magnetization M is not parallel to the long axis of the bit line B but is inclined. As a result, as shown in FIG. 3, the asteroid curve is no longer line-symmetric with respect to the bit line or the word line, and the action of the magnetic field from the intermediate wiring on the upper and lower magnetoresistive elements is not equivalent. You can As a result, write crosstalk can be suppressed.

Further, the ratio L / D of the width D and the length L of the magnetic recording layer of the magnetoresistive effect element is preferably larger than 1.2, and the uniaxial anisotropy is in the direction of the length L. It is desirable that it is given. In addition, in FIG. 2 to FIG.
For simplicity, I drew the asteroid curve isotropically,
When the magnetic recording layer is elongated as described above, the asteroid curve has a flattened shape. However, also in this case, the same effects as those described above with reference to FIGS. 2 to 6 can be obtained.

In the specific examples described above with reference to FIGS. 2 to 5, the bit lines and the word lines are made orthogonal to each other, and the shape of the magnetic recording layer of the magnetoresistive element is provided so as to be asymmetric with respect to these. , Write crosstalk is suppressed.

However, the present invention is not limited to these specific examples, and in addition to this, for example, the bit lines and the word lines may be made to intersect with each other at an angle instead of being orthogonal to each other.

FIG. 6 is a schematic diagram for explaining a concrete example in which the bit lines and the word lines are inclined as described above. That is, FIG. 1A shows the planar configuration of the cell of the upper magnetoresistive effect element C1 shown in FIG. 1, and FIG. 1B is a schematic diagram showing the asteroid curve of the magnetic recording layer. . Further, FIG. 6C shows a planar configuration of a cell of the lower magnetoresistive effect element C2 shown in FIG. 1, and FIG. 6D is a schematic diagram showing an asteroid curve of the magnetic recording layer. is there. That is, FIG. 6 shows a specific example in which the word line W1 is inclined with respect to the direction of the magnetization M of the magnetoresistive effect element.

By doing so, FIGS. 6B and 6D are shown.
As shown in, the magnetic fields Hw1 and Hw from the word line W1
The w2s act in directions opposite to each other along the inclined direction with respect to the symmetry axis of the magnetization reversal asteroid curve.
As a result, a difference occurs between the magnetic fields Hb1 and Hb2 from the bit line required for the magnetization reversal.

That is, the magnetic field Hb1 from the bit line B1 required to invert the magnetization M of the upper magnetoresistive effect element C1 is as shown in FIG. 6B. On the other hand, the magnetic field H from the bit line B2 required to reverse the magnetization M of the lower magnetoresistive effect element C2.
b2 is as shown in FIG. 6D and is larger than Hb1.

That is, the combined magnetic field Ht1 for writing the upper magnetoresistive effect element C1 is smaller than the combined magnetic field Ht2 required for reversing the magnetization of the lower magnetoresistive effect element C2. As a result, when writing is performed on the magnetoresistive effect element C1 on the upper side, write crosstalk on the magnetoresistive effect element C2 on the lower side can be eliminated.

Although FIG. 6 illustrates the case where the bit lines are substantially perpendicular to the magnetization direction M of the magnetoresistive effect element and the word lines are inclined, the magnetization direction is opposite. The same action and effect can be obtained by wiring the word lines substantially in parallel to M and sloping the bit lines obliquely instead of vertically.

The basic structure of the memory cell according to the present invention has been described above with reference to FIGS.

Next, a magnetoresistive effect element that can be used in the magnetic memory of the present invention will be described. As the magnetoresistive effect element, an element having a TMR structure in which a first ferromagnetic layer, an insulating layer, and a second ferromagnetic layer are laminated, a first ferromagnetic layer, a nonmagnetic layer, and a second ferromagnetic layer. A device having a “spin valve structure” in which layers are stacked can be used.

In each case, the first ferromagnetic layer is caused to act as a "magnetization pinned layer (sometimes referred to as" pinned layer "etc.)" in which the magnetization direction is substantially fixed, and the second ferromagnetic layer is used. The ferromagnetic layer can be made to act as a "magnetic recording layer" whose magnetization direction is variable by applying a magnetic field from the outside.

As will be described later in detail, depending on the reading method, the first ferromagnetic layer is a “magnetization free layer (also referred to as a“ free layer ”) in which the magnetization direction is variable. The second ferromagnetic layer may be made to act as a “magnetic recording layer” for recording magnetization by applying a writing magnetic field from the outside.

In these magnetoresistive effect elements, as the ferromagnetic material that can be used as the magnetization pinned layer, for example, Fe (iron), Co (cobalt), Ni (nickel) or their alloys, or spin polarizability is used. High magnetite, CrO ₂ , RXMnO _3-y (where R is rare earth, X is Ca (calcium), Ba (barium), S
An oxide such as r (representing any of strontium) or a Heusler alloy such as NiMnSb (nickel-manganese-antimony) or PtMnSb (platinum-manganese-antimony) can be used.

The magnetization fixed layer made of these materials preferably has unidirectional anisotropy. The thickness is 0.
1 nm to 100 nm is preferable. Furthermore, the film thickness of this ferromagnetic layer needs to be such that superparamagnetism does not occur, and is more preferably 0.4 nm or more.

Further, it is desirable to add an antiferromagnetic film to the ferromagnetic layer used as the magnetization pinned layer to pin the magnetization. As such an antiferromagnetic film, Fe (iron) -Mn
(Manganese), Pt (platinum) -Mn (manganese), Pt
(Platinum) -Cr (Chromium) -Mn (Manganese), Ni
(Nickel) -Mn (manganese), Ir (iridium)
-Mn (manganese), NiO (nickel oxide), Fe ₂
Examples thereof include O ₃ (iron oxide).

Further, these magnetic materials include Ag (silver), C
u (copper), Au (gold), Al (aluminum), Mg
(Magnesium), Si (silicon), Bi (bismuth), Ta (tantalum), B (boron), C (carbon),
O (oxygen), N (nitrogen), Pd (palladium), Pt
(Platinum), Zr (zirconium), Ir (iridium), W (tungsten), Mo (molybdenum), Nb
By adding a non-magnetic element such as (niobium), it is possible to control the magnetic properties and various physical properties such as crystallinity, mechanical properties and chemical properties. On the other hand, a laminated film of a ferromagnetic layer and a nonmagnetic layer may be used as the magnetization fixed layer. For example, a three-layer structure of ferromagnetic layer / nonmagnetic layer / ferromagnetic layer can be used. In this case, it is desirable that antiferromagnetic interaction between layers be exerted on both ferromagnetic layers via the nonmagnetic layer.

More specifically, as a method of fixing the magnetic layer in one direction, Co (Co-Fe) / Ru (ruthenium) / Co (Co-Fe), Co (Co-Fe) / I
r (iridium) / Co (Co-Fe), Co (Co
It is desirable to use a laminated film having a three-layer structure such as —Fe) / Os (osnium) / Co (Co—Fe) as a magnetization fixed layer, and further provide an antiferromagnetic film adjacent thereto. In this case, the antiferromagnetic film also has the same structure as that of Fe as described above.
-Mn, Pt-Mn, Pt-Cr-Mn, Ni-Mn,
Ir-Mn, NiO, and _Fe 2 _{O 3} can be used. With this structure, the magnetization of the magnetization pinned layer is less likely to be affected by the current magnetic field from the bit line or word line, and the magnetization is firmly pinned. In addition, the stray field from the pinned layer can be reduced (or adjusted),
The magnetization shift of the magnetic recording layer (magnetic recording layer) can be adjusted by changing the film thickness of the two ferromagnetic layers forming the magnetization fixed layer.

On the other hand, the material of the magnetic recording layer (free layer) is, for example, Fe, like the magnetization pinned layer.
(Iron), Co (cobalt), Ni (nickel) or their alloys, magnetite with a large spin polarization, C
rO ₂ , RXMnO _3-y (where R is a rare earth, X is C
an oxide such as a (calcium), Ba (barium), or Sr (strontium)), or
NiMnSb (nickel, manganese, antimony), P
A Heusler alloy such as tMnSb (platinum manganese / antimony) can be used.

The ferromagnetic layer as a magnetic recording layer made of these materials preferably has uniaxial anisotropy in a direction substantially parallel to the film surface. The thickness is preferably 0.1 nm to 100 nm. Furthermore, the film thickness of this ferromagnetic layer must be such that superparamagnetism does not occur,
More preferably, it is 4 nm or more.

The magnetic recording layer may have a two-layer structure of soft magnetic layer / ferromagnetic layer or a three-layer structure of ferromagnetic layer / soft magnetic layer / ferromagnetic layer. By using a three-layer structure of ferromagnetic layer / nonmagnetic layer / ferromagnetic layer as the magnetic recording layer, the strength of the interaction between the layers of the ferromagnetic layer is controlled to control the cells of the magnetic recording layer, which is a memory cell. Even if the width is less than or equal to submicron, the more preferable effect that the power consumption of the current magnetic field is not increased can be obtained.

Also in the magnetization recording layer, these magnetic materials are
Ag (silver), Cu (copper), Au (gold), Al (aluminum), Mg (magnesium), Si (silicon), B
i (bismuth), Ta (tantalum), B (boron), C
(Carbon), O (oxygen), N (nitrogen), Pd (palladium), Pt (platinum), Zr (zirconium), Ir (iridium), W (tungsten), Mo (molybdenum), Nb (niobium), etc. By adding a non-magnetic element, magnetic properties can be adjusted, and various other physical properties such as crystallinity, mechanical properties, and chemical properties can be adjusted.

On the other hand, when a TMR element is used as the magnetoresistive effect element, Al ₂ O is used as the insulating layer (or dielectric layer) provided between the magnetization fixed layer and the magnetization recording layer.
₃ (aluminum oxide), SiO ₂ (silicon oxide),
MgO (magnesium oxide), AlN (aluminum nitride), Bi ₂ O ₃ (bismuth oxide), MgF ₂ (magnesium fluoride), CaF ₂ (calcium fluoride), Sr
TiO ₂ (titanium oxide / strontium), AlLaO
Various insulators (dielectrics) such as ₃ (lanthanum oxide aluminum) and Al—N—O (aluminum oxynitride) can be used.

These compounds do not have to be completely accurate in terms of stoichiometry, and oxygen, nitrogen, fluorine, etc. may be deficient or deficient. Further, the thickness of the insulating layer (dielectric layer) is preferably as thin as a tunnel current flows, and is practically preferably 10 nm or less.

Such a magnetoresistive effect element can be formed on a predetermined substrate by using ordinary thin film forming means such as various sputtering methods, vapor deposition methods and molecular beam epitaxial methods. In this case, the substrate is, for example, Si (silicon), SiO ₂ (silicon oxide), Al ₂ O ₃ (aluminum oxide), spinel, AlN (aluminum nitride).
Various substrates can be used.

On the substrate, Ta (tantalum), Ti (titanium), Pt (platinum), Pd (palladium), Au (gold), Ti (titanium) / Pt ( Platinum), Ta (tantalum) / Pt (platinum), Ti (titanium) / Pd (palladium), Ta (tantalum) / Pd (palladium), Cu (copper), Al (aluminum) -Cu (copper), Ru ( Ruthenium), Ir
A layer made of (iridium), Os (osmium), or the like may be provided.

The arrangement relationship between the magnetoresistive effect element and the bit line and the word line in the magnetic memory of the present invention has been described above.

Next, the cell structure of the magnetic memory of the present invention will be described with reference to specific examples. Magnetic memory for semiconductor DR
In order to make the capacity larger than that of AM, it is not preferable to use an architecture (1Tr-1MR architecture) using one transistor and one magnetoresistive element per cell. This is because it is difficult to stack memory arrays with this architecture.

That is, in order to realize an ultra-large-capacity memory, it is desirable to use an architecture capable of stacking memory arrays and to make them multi-layered.

FIG. 7 is a schematic diagram showing a first specific example of the architecture in which the memory arrays can be stacked. That is, the figure shows the cross-sectional structure of the memory array. In this architecture, the magnetoresistive element C is connected in parallel to the read / write bit line B. A read / write word line W is connected to the other end of each magnetoresistive element C via a diode D.

At the time of reading, the bit line B and the word line W connected to the target magnetoresistive effect element C are selected by the selection transistors STB and STW to select the sense amplifier S.
The current is detected by A.

At the time of writing, the bit line B and the word line W, which are also connected to the target magnetoresistive effect element C, are selected by the select transistors STB and STW,
Apply write current. At this time, writing can be performed by causing the writing magnetic field, which is a combination of the magnetic fields generated in the bit line B and the word line W, to direct the magnetization of the magnetic recording layer of the magnetoresistive effect element C in a predetermined direction.

The diode D has a role of blocking a bypass current flowing through another magnetoresistive effect element C wired in a matrix at the time of reading or writing.

FIG. 8 is a schematic diagram showing a state in which the memory arrays shown in FIG. 7 are stacked. In addition, in FIG.
For simplicity, only the bit line B, the magnetoresistive effect element C, the diode D, and the word line W are shown, and the other elements are omitted.

FIG. 8A shows a concrete example in which the memory arrays shown in FIG. 7 are vertically stacked as they are. That is, the memory array in each layer has the respective bit line B and word line. Then, for example, the word line W1 is used to read and write data only from the magnetoresistive effect element C1 connected thereto.

Here, the side wall and the lower surface of the word line are
It is preferably covered with a coating layer SM made of a soft magnetic material. This is to prevent the write magnetic field generated by the word line W from leaking toward the magnetoresistive effect element adjacent in the same layer and in the lower layer. In this way, write crosstalk can be prevented even more effectively.

Here, it is desirable that the coating layer SM is provided outside the magnetoresistive effect element C. By doing so, the write magnetic field from the word line W can be uniformly applied to the magnetoresistive effect element C.

Furthermore, by providing a similar covering layer SM on the side surface of the write bit line, it is possible to suppress crosstalk to the adjacent magnetoresistive effect element.

Here, for example, Cu (copper) is used as the material of the word line, and a magnetic amorphous material such as FeOx (iron oxide) or CoZnNb (cobalt zinc niobium) is used as the material of the coating layer SM around it. CoFeNi
Magnetic alloys such as (cobalt iron nickel), NiFe (nickel iron), and permalloy can be used.

On the other hand, FIG. 8B shows a specific example in which the word lines W are stacked so as to be shared by the upper and lower memory arrays. For example, the magnetoresistive effect element C1 of the first layer and the magnetoresistive effect element C2 of the second layer are connected to a common word line W1. If the word lines are shared in this way, the structure can be simplified, the degree of integration can be increased, and the manufacturing cost can be reduced.

Further, in this case, by covering the side wall of the word line with the soft magnetic coating layer SM, it is possible to suppress the leakage of the write magnetic field toward the surrounding magnetoresistive effect element, and to further effectively improve the write crosstalk. Can be prevented.

FIG. 9 is a schematic view illustrating the planar arrangement of the stacked memory array shown in FIG. That is, FIG.
8A and 8B show the arrangement of the magnetoresistive effect elements in each layer of the stacked memory array shown in FIGS. 8A and 8B.

In the case of the specific example shown in FIG. 9A, each magnetoresistive effect element has the same asymmetrical shape as that shown in FIG. 4A. And these magnetoresistive effect elements are arrange | positioned in the same direction between different layers. For example, in FIG. 9A, the magnetoresistive effect elements surrounded by circles are adjacent to each other in the vertical direction. By disposing the asymmetrical magnetoresistive elements in the same direction in the adjacent layers, that is, in the vertical direction, write crosstalk between the upper and lower magnetoresistive elements is prevented as described above with reference to FIG. be able to.

On the other hand, also in the case of the specific example shown in FIG. 9B, each magnetoresistive effect element is the same as that shown in FIG.
It has an asymmetric shape similar to that shown in FIG. However, when these directions are seen, they are alternately arranged in opposite directions in the same layer. That is, adjacent magnetoresistive effect elements in the same layer are arranged so that the asymmetrical directions are opposite to each other. With such an arrangement, the magnetic field effect acts oppositely between adjacent magnetoresistive effect elements, so that write crosstalk can be suppressed.

Further, when viewed between the layers, that is, when viewed in the vertical direction, the magnetoresistive effect elements are arranged so that the asymmetrical directions are the same. That is, FIG.
Also in (b), the magnetoresistive element surrounded by a circle is
Each of them is adjacent in the vertical direction. With such an arrangement, as described above with reference to FIG. 3, write crosstalk between the upper and lower magnetoresistive elements can be prevented.

On the other hand, the plane arrangement shown in FIG. 9 is merely an example, and for example, as the plane shape of the magnetoresistive effect element, various asymmetric shapes such as the shape exemplified in FIG. 4 can be given. . That is, at least a part of the magnetization direction of the magnetic recording layer may be neither parallel nor perpendicular to the bit line or the word line.

Furthermore, as illustrated in FIG. 6, the same effect can be obtained by arranging the bit lines and the word lines so as not to be vertical but at an angle.

Next, a second specific example of the architecture that can be adopted in the magnetic memory of the present invention will be described.

FIG. 10 is a schematic diagram showing a second specific example of the architecture in which the memory arrays can be stacked. That is, the figure shows the cross-sectional structure of the memory array.

In this architecture, a plurality of magnetoresistive effect elements C are connected in parallel between the read / write bit line Bw and the read bit line Br to form a "ladder type" structure. Further, the write word line W is arranged in the direction crossing the bit line in the vicinity of each magnetoresistive element C.

Writing to the magnetoresistive effect element is performed by combining a magnetic field generated by applying a write current to the read / write bit line Bw and a magnetic field generated by applying a write current to the write word line W. This can be done by acting on the magnetic recording layer of the magnetoresistive effect element.

On the other hand, at the time of reading, a voltage is applied between the bit lines Bw and Br. Then, a current flows through all the magnetoresistive effect elements connected in parallel between them. While detecting the total of this current by the sense amplifier SA, the word line W adjacent to the target magnetoresistive effect element is detected.
A write current is applied to the target to rewrite the magnetization of the magnetic recording layer of the target magnetoresistive effect element in a predetermined direction. The target magnetoresistive effect element can be read by detecting the current change at this time.

That is, if the magnetization direction of the magnetic recording layer before rewriting is the same as the magnetization direction after rewriting, the current detected by the sense amplifier SA does not change. But,
When the magnetization direction of the magnetic recording layer is reversed before and after rewriting, the current detected by the sense amplifier SA changes due to the magnetoresistive effect. In this way, the magnetization direction of the magnetic recording layer before rewriting, that is, the stored data can be read.

However, this method corresponds to so-called "destructive read" in which the stored data is changed at the time of read.

On the other hand, when the structure of the magnetoresistive effect element is a structure of magnetization free layer / insulating layer (nonmagnetic layer) / magnetic recording layer, so-called “nondestructive read” is performed.
Is possible. That is, when using the magnetoresistive element having this structure, the magnetization direction is recorded in the magnetic recording layer, and at the time of reading, by changing the magnetization direction of the magnetization free layer appropriately and comparing the sense currents, The magnetization direction of the magnetic recording layer can be read. However, in this case, it is necessary to design so that the magnetization switching field of the magnetic free layer is smaller than the magnetization switching field of the magnetic recording layer.

FIG. 11 is a schematic diagram showing a state in which the “ladder type” memory array shown in FIG. 10 is stacked. In addition,
In FIG. 8, for simplicity, the bit lines Bw and Bw
Only r, the magnetoresistive element C, and the word line W are shown, and the other elements are omitted.

FIG. 11A shows a specific example in which the memory arrays shown in FIG. 10 are vertically stacked as they are. That is, the memory array of each layer has the bit lines Bw,
It has Br and a word line W. Then, for example, the word line W1 is used for writing data only to the magnetoresistive effect element C1 connected thereto.

Also in this case, by covering the side wall and the lower surface of the word line W with the soft magnetic coating layer SM, the write magnetic field is prevented from leaking toward the magnetoresistive effect element adjacent in the same layer and in the lower layer. It is possible to prevent write crosstalk more effectively.

On the other hand, FIG. 11B shows a specific example in which the word lines W are stacked so as to be shared by the upper and lower memory arrays. For example, writing is performed by the common word line W1 in the magnetoresistive effect element C1 of the first layer and the magnetoresistive effect element C2 of the second layer. If the word lines are shared in this way, the structure can be simplified and the degree of integration can be increased.
Manufacturing costs can also be reduced.

Further, in this case, by covering the side wall of the word line with the soft magnetic coating layer SM, it is possible to suppress the leakage of the write magnetic field toward the surrounding magnetoresistive effect element, and to further effectively improve the write crosstalk. Can be prevented. The same applies to the bit line Bw.

In the case of the "ladder type" memory array shown in FIGS. 10 and 11, the plane arrangement can be the same as that shown in FIG. That is, as shown in FIG. 9A, by disposing asymmetrical magnetoresistive effect elements in adjacent layers, that is, in the same direction in the vertical direction, write crosstalk between the upper and lower magnetoresistive elements. Can be prevented.

Further, as shown in FIG. 9B, by arranging adjacent magnetoresistive effect elements in the same layer so that the directions of asymmetry are opposite to each other, the write crosstalk therebetween can be prevented. Can be suppressed.

Furthermore, as illustrated in FIG. 6, the same effect can be obtained by arranging the bit lines and the word lines so as not to be perpendicular but at an angle.

Next, the third concrete example of the architecture that can be adopted in the magnetic memory of the present invention will be explained.

FIG. 12 is a schematic diagram showing a third specific example of the architecture in which the memory arrays can be stacked. That is, the figure shows the cross-sectional structure of the memory array.

In this architecture, a plurality of magnetoresistive effect elements C are provided on the read / write bit line Bw.
Are connected in parallel, and read bit lines Br are connected in a matrix to the other ends of these magnetoresistive elements.

Further, a write word line W is arranged near the read bit line Br. For writing to the magnetoresistive element, a combined magnetic field of a magnetic field generated by applying a write current to the read / write bit line Bw and a magnetic field generated by applying a write current to the write word line W is used. This can be done by acting on the magnetic recording layer of the effect element.

On the other hand, at the time of reading, by selecting the bit lines Bw and Br by the selection transistors ST1 and ST2, a sense current can be passed through the target magnetoresistive effect element and detected by the sense amplifier SA. .

FIG. 13 is a schematic diagram showing a state in which the memory arrays shown in FIG. 12 are stacked. Also in FIG.
For simplicity, only the bit lines Bw and Br, the magnetoresistive effect element C, and the word line W are shown, and the other elements are omitted.

FIG. 13A shows a specific example in which the memory arrays shown in FIG. 12 are vertically stacked as they are. That is, the memory array of each layer has the bit lines Bw,
It has Br and a word line W. Then, for example, the word line W1 is used to write data only to the magnetoresistive effect element C1 adjacent to the word line W1.

Also in this case, by covering the side wall and the lower surface of the word line W with the soft magnetic coating layer SM, the write magnetic field is prevented from leaking toward the magnetoresistive effect element adjacent in the same layer and in the lower layer. It is possible to prevent write crosstalk more effectively.

On the other hand, FIG. 13B shows a specific example in which the word lines W are stacked so as to be shared by the upper and lower memory arrays. For example, writing is performed by the common word line W1 in the magnetoresistive effect element C1 of the first layer and the magnetoresistive effect element C2 of the second layer. If the word lines are shared in this way, the structure can be simplified and the degree of integration can be increased.
Manufacturing costs can also be reduced.

Further, in this case, by covering the side wall of the word line with the soft magnetic coating layer SM, it is possible to suppress the leakage of the write magnetic field toward the surrounding magnetoresistive effect element, and to further effectively improve the write crosstalk. Can be prevented. The same applies to the bit line Bw.

In the case of the memory array shown in FIGS. 12 and 13, the plane arrangement can be the same as that shown in FIG. That is, as shown in FIG. 9A, by disposing asymmetrical magnetoresistive effect elements in adjacent layers, that is, in the same direction in the vertical direction, write crosstalk between the upper and lower magnetoresistive elements. Can be prevented.

Further, as shown in FIG. 9B, by arranging the adjacent magnetoresistive effect elements in the same layer so that the directions of asymmetry are opposite to each other, the write crosstalk therebetween can be prevented. Can be suppressed.

Further, as illustrated in FIG. 6, the same effect can be obtained by arranging the bit lines and the word lines not at right angles but at a slant to intersect.

Next, a fourth specific example of the architecture that can be adopted in the magnetic memory of the present invention will be described.

FIG. 14 is a schematic diagram showing a fourth specific example of the architecture in which the memory arrays can be stacked. That is, the figure shows the cross-sectional structure of the memory array.

This architecture is shown in FIG. 12 and FIG.
It has a configuration similar to that illustrated in FIG. However, the difference is that the read bit line Br is connected to the magnetoresistive effect element C via a lead L, and the write word line W is provided immediately below the magnetoresistive effect element C. By doing so, the magnetoresistive effect element C and the word line W can be closer to each other than in the structure of FIG. As a result,
The write magnetic field from the word line W can be more effectively applied to the magnetoresistive effect element.

The operation of the memory array of this specific example is the same as that described above with reference to FIG. 12, and therefore its explanation is omitted.

FIG. 15 is a schematic diagram showing a state in which the memory arrays shown in FIG. 14 are stacked. Also in FIG.
For simplicity, only the bit lines Bw and Br, the magnetoresistive effect element C, the word line W, and the lead L are shown, and the other elements are omitted.

FIG. 15A shows a concrete example in which the memory array shown in FIG. 14 is vertically laminated as it is. That is, the memory array of each layer has the bit lines Bw,
It has Br and a word line W. Then, for example, the word line W1 is used to write data only to the magnetoresistive effect element C1 adjacent to the word line W1.

Also in this case, by covering the side wall and the lower surface of the word line W with the soft magnetic coating layer SM, the write magnetic field is prevented from leaking toward the magnetoresistive effect element adjacent in the same layer and in the lower layer. It is possible to prevent write crosstalk more effectively.

On the other hand, FIG. 15B shows a specific example in which the word line W and the bit line Br are stacked so as to be shared by the upper and lower memory arrays. For example, writing is performed by the common word line W1 in the magnetoresistive effect element C1 of the first layer and the magnetoresistive effect element C2 of the second layer. Further, these are read by the common bit line Br. If the word line and the bit line are shared in this way, the structure can be simplified, the degree of integration can be increased, and the manufacturing cost can be reduced.

Further, in this case, by covering the side wall of the word line with the soft magnetic coating layer SM, it is possible to suppress the leakage of the write magnetic field toward the surrounding magnetoresistive effect element, and to further effectively improve the write crosstalk. Can be prevented. The same applies to the bit line Bw.

In the case of the memory array shown in FIGS. 14 and 15, the plane arrangement can be the same as that shown in FIG. That is, as shown in FIG. 9A, by disposing asymmetrical magnetoresistive effect elements in adjacent layers, that is, in the same direction in the vertical direction, write crosstalk between the upper and lower magnetoresistive elements. Can be prevented.

Further, as shown in FIG. 9B, by arranging the adjacent magnetoresistive effect elements in the same layer so that the directions of asymmetry are opposite to each other, the write crosstalk therebetween can be prevented. Can be suppressed.

Further, as illustrated in FIG. 6, the same effect can be obtained by arranging the bit lines and the word lines not vertically but by inclining and intersecting each other.

[0136]

Embodiments of the present invention will be described in more detail below with reference to embodiments.

(First Embodiment) First, as a first embodiment of the present invention, based on the memory array of the simple matrix structure shown in FIG. 14, a memory array having 3 × 3 cells in two layers. A laminated magnetic memory was formed.

FIG. 16A is a sectional view of the magnetic memory manufactured in this embodiment, and FIG. 16B is a plan view of the memory arrays of the first and second layers thereof.

The structure of this magnetic memory will be described below in accordance with its manufacturing procedure.

On a substrate (not shown), a wiring layer of Al—Cu (5%) / Ta having a thickness of 1 μm is first formed as a lower layer bit line Bw1 by a sputtering method. Then, CMP (Chemical Mechanical Polishing) was performed to form a laminated structure film of the TMR element C1 having a ferromagnetic tunnel junction by a sputtering method. The material and layer thickness of each layer are Ta (5 nm) / Ru (3 n
m) / Ir-Mn (9 nm) / CoFe (3 nm) / R
u (1nm) / CoFe (3nm) / AlOx (1n
m) / CoFeNi (2 nm) / AlOx (1 nm) /
CoFe (3nm) / Ru (1nm) / CoFe (3n
m) / IrMn (9 nm) / Ta (9 nm) / Ru (3
0 nm).

Next, using the uppermost Ru layer as a hard mask, RIE (Reac
By etching the laminated structure film down to the lower AlOx layer by tive ion etching, an isolated pattern of the TMR element was produced. At this time, each TMR element was asymmetric as shown in FIG. 16B, and the TMR elements were patterned so that the asymmetrical directions were alternately arranged in the same layer.

Then, using an ion milling, Al--
The lower layer bit line Bw1 was formed by selectively etching the Cu (5%) / Ta wiring.

After that, SiOx is deposited as an insulator by a sputtering method and flattened by CMP, and then a lead L is formed.
The metal contact layers M1 and M2 as the bit line Bw1
The film was formed and patterned in the same manner as in. further,
SiOx was deposited on this and flattened by CMP.

After that, a Cu layer is formed by using a plating method and is patterned, whereby the word line W and the bit line B are formed.
r1 and Br2 were formed. After this, deposition of SiOx, C
By repeating steps such as planarization by MP, film formation, and patterning as appropriate, the metal contact layers M4, M5,
The TMR element C2 and the bit line Bw2 are sequentially formed, and
The magnetic memory shown in 6 was manufactured.

Separately from this, as a comparative example, TM
A magnetic memory using a rectangular TMR element in which the R element is line-symmetric with respect to the long axis direction of the bit line Bw was also manufactured.

The magnetic memories of the present invention and the comparative example are then introduced into a heat treatment furnace to which a magnetic field can be applied, and uniaxial anisotropy is applied to the magnetic recording layer of the TMR element and unidirectional anisotropy is applied to the magnetic pinned layer. Introduced respectively.

An experiment was conducted to examine the influence of write crosstalk in the magnetic memories of the present invention and comparative example thus manufactured. That is, by applying a current pulse of 100 nanoseconds to the wiring, writing “0” and “1” in order to the nine TMR elements C1 in the lower layer,
The nine TMR elements C2 in the upper layer were read out each time to examine the influence of crosstalk. Here, in the initial state of the TMR element C2, the magnetizations of the magnetization pinned layer and the magnetic recording layer were all aligned in parallel.

FIG. 17 is a graph showing the change of the average value of the outputs of the nine upper TMR elements C2. As can be seen from the figure, in the comparative example, the lower TMR element C1 is used.
When the number of times of writing to was increased, the read output (that is, the resistance value) of the upper TMR element C2 gradually changed. This is because crosstalk occurs in the TMR element C2 in the upper layer when writing is performed in the TMR element C1 in the lower layer.

On the other hand, according to the present invention, the T of the lower layer is
Even if the writing of the MR element C1 was repeated, the output of the TMR element C2 in the upper layer did not change, and it was verified that the write crosstalk was eliminated.

(Second Embodiment) Next, as a second embodiment of the present invention, a memory array having 3 × 3 cells based on the memory array of the “ladder type” structure shown in FIG. To form a magnetic memory in which two layers are laminated.

FIG. 18A is a sectional view of the magnetic memory manufactured in this embodiment, and FIG. 16B is a plan view of the memory arrays of the first and second layers thereof.

The structure of this magnetic memory will be described below in accordance with its manufacturing procedure.

On a substrate (not shown), a wiring layer of Al—Cu (5%) / Ta having a thickness of 1 μm is first formed as a lower layer bit line Bw1 by a sputtering method. Then, CMP (Chemical Mechanical Polishing) was performed to form a laminated structure film of the TMR element C1 having a ferromagnetic tunnel junction by a sputtering method.

The material and layer thickness of each layer are Ta (5 nm) / Ru (3 nm) / Pt—Mn (1
2 nm) / CoFe (3 nm) / Ru (1 nm) / Co
Fe (3 nm) / AlOx (1 nm) / CoFeNi
(2 nm) / Ru (1.5 nm) / CoFeNi (2n
m) / AlOx (1 nm) / CoFe (3 nm) / Ru
(1 nm) / CoFe (3 nm) / IrMn (9 nm)
/ Ta (9 nm) / Ru (30 nm).

Since the subsequent process is substantially the same as that described above with respect to the first embodiment, its description is omitted.

Separately from this, as a comparative example, TM
A magnetic memory using a rectangular TMR element in which the shape of the R element is line-symmetric with respect to the long axis direction of the bit line was also created.

The magnetic memories of the present invention and the comparative example are then introduced into a heat treatment furnace to which a magnetic field can be applied, and the magnetic recording layer of the TMR element is given uniaxial anisotropy and the magnetic pinned layer is given unidirectional anisotropy. Introduced respectively.

In the magnetic memories of the present invention and the comparative example thus manufactured, an experiment for examining the influence of write crosstalk was conducted as in the first embodiment. That is,
By passing a 100 nanosecond current pulse through the wire,
"0" and "1" were sequentially written in the lower nine TMR elements C1 and the upper nine TMR elements C2 were read each time to examine the influence of crosstalk. Here, also in the initial state of the TMR element C2, the magnetizations of the magnetization pinned layer and the magnetic recording layer were all aligned in parallel.

FIG. 19 is a graph showing changes in the average value of the outputs of the nine upper TMR elements C2. As can be seen from the figure, in the comparative example, the lower TMR element C1 is used.
When the number of times of writing to was increased, the read output of the upper TMR element C2 greatly increased. This is because when writing to the TMR element C1 in the lower layer, the TM in the upper layer is
This is because crosstalk occurs in the R element C2.

On the other hand, according to the present invention, the lower T
Even if the writing of the MR element C1 was repeated, the output of the TMR element C2 in the upper layer did not change, and it was verified that the write crosstalk was eliminated.

Heretofore, the embodiments of the present invention have been described with reference to specific examples. However, the present invention is not limited to these specific examples. For example, a ferromagnetic layer, an insulating film, an antiferromagnetic layer that constitutes a magnetoresistive effect element,
Specific materials such as the non-magnetic metal layer, the electrodes, and the like, the film thickness, shape, dimensions, and the like can be appropriately implemented by those skilled in the art to carry out the present invention in the same manner and obtain similar effects. Within the scope of the present invention.

Similarly, the structure, material, shape, and size of each element constituting the magnetic memory of the present invention can be appropriately selected by those skilled in the art to carry out the present invention in the same manner and obtain the same effect. Those that can be included are also included in the scope of the present invention.

Further, the present invention can be similarly applied to a magnetic head or a magnetic reproducing apparatus of a perpendicular magnetic recording system as well as a longitudinal magnetic recording system to obtain the same effect.

In addition, all magnetic memories that can be appropriately designed and modified by those skilled in the art based on the magnetic memories described above as the embodiments of the present invention also belong to the scope of the present invention.

[0165]

As described in detail above, according to the present invention,
In a magnetic memory in which memory arrays are stacked, the action of a write magnetic field obtained by passing a current through a first wiring and a second wiring in order to write to a target magnetoresistive effect element has an effect of a target magnetoresistive effect. The element and the upper and lower magnetoresistive elements adjacent to the element can be acted differently. As a result, write crosstalk between the upper and lower magnetoresistive elements can be eliminated.

That is, according to the present invention, it is possible to realize a highly integrated magnetic memory in which a plurality of memory arrays are stacked while suppressing write crosstalk, and the industrial merit is great.

[Brief description of drawings]

FIG. 1 is a schematic view showing a unit cell of a magnetic memory according to the present invention in a simplified manner. FIG.
(B) shows the cross-sectional structure.

FIG. 2 is a schematic diagram showing a comparative example to which the present invention is not applied.

FIG. 3 is a schematic diagram illustrating the operation of a specific example of the present invention.

FIG. 4 is a schematic diagram showing another specific example of the planar form of the magnetic recording layer of the magnetoresistive effect element according to the present invention.

FIG. 5 is a schematic diagram showing a pattern shape of a reticle for forming a magnetoresistive effect element having the shape illustrated in FIG. 4A.

FIG. 6 is a schematic diagram illustrating a specific example in which a bit line and a word line are inclined.

FIG. 7 is a schematic diagram showing a first specific example of an architecture capable of stacking memory arrays.

8 is a schematic view showing a state in which the memory arrays shown in FIG. 7 are stacked.

9 is a schematic view illustrating a planar arrangement of the stacked memory array shown in FIG.

FIG. 10 is a schematic diagram showing a second specific example of the architecture in which the memory arrays can be stacked.

FIG. 11 is a schematic view showing a state in which the “ladder type” memory array shown in FIG. 10 is stacked.

FIG. 12 is a schematic diagram showing a third specific example of the architecture in which the memory arrays can be stacked.

13 is a schematic diagram showing a state in which the memory arrays shown in FIG. 12 are stacked.

FIG. 14 is a schematic diagram showing a fourth specific example of the architecture in which the memory arrays can be stacked.

15 is a schematic diagram showing a state in which the memory arrays shown in FIG. 14 are stacked.

16A is a cross-sectional view of the magnetic memory manufactured in the first embodiment of the present invention, and FIG. 16B is a plan view of the memory arrays of the first and second layers thereof.

FIG. 17 is a graph showing changes in average value of outputs of nine upper TMR elements C2.

FIG. 18A is a sectional view of a magnetic memory manufactured in a second embodiment of the present invention, and FIG. 18B is a plan view of a memory array of the first and second layers thereof.

FIG. 19 is a graph showing changes in average value of outputs of nine upper TMR elements C2.

[Explanation of symbols]

B, B1 to B4 bit lines Br read bit line Bw write / read bit line C, C1-C4 magnetoresistive effect element D diode L lead L1, L2 metal contact layer SA sense amplifier SM coating layer ST, STb, STW selection transistor W, W1, W2 word line

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tatsuya Kishi             1st Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa             Inside the Toshiba Research and Development Center (72) Inventor Shigeki Takahashi             1st Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa             Inside the Toshiba Research and Development Center (72) Inventor Katsuya Nishiyama             1st Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa             Inside the Toshiba Research and Development Center F-term (reference) 5F083 FZ10 GA15 JA36 JA37 JA39                       JA60 KA01 KA05 LA03 PR03                       PR04 PR22 PR40

Claims (9)

[Claims] 1. A first magnetoresistive effect element, a first wiring extending on the first magnetoresistive effect element, and a second magnetic element provided on the first wiring. A resistance effect element; and a second wiring extending on the second magnetoresistance effect element in a direction intersecting with the first wiring, the first and second magnetoresistance effect elements Has a magnetic recording layer having magnetization anisotropy in substantially the same direction, and the first and second magnetic recording layers
The magnetization of the magnetic recording layer of the second magnetoresistive effect element is reversible by a magnetic field formed by passing a current through the wiring, and the magnetic recording layers of the first and second magnetoresistive effect elements are reversible. A magnetic memory, wherein at least a part of the magnetization direction is inclined with respect to at least one of the first and second wirings. 2. A first memory array having a plurality of magnetoresistive effect elements arranged in a matrix, and a plurality of magnetoresistive effect elements stacked on the first memory array and arranged in a matrix. A second memory array having: a first wiring extending below the magnetoresistive effect element and a magnetoresistive effect element of each of the first and second memory arrays; A second wiring extending above in a direction intersecting the first wiring, and arranged between them by a magnetic field formed by passing a current through the first and second wirings. The magnetization of the magnetic recording layer of the magnetoresistive effect element can be reversed, and the magnetic recording layers of the magnetoresistive effect element in the first and second memory arrays have magnetization anisotropies in substantially the same direction. , These magnetic notes Magnetic memory at least part of the magnetization direction of the layer is characterized by comprising inclined relative to at least one of said first and second wiring. 3. The second wiring provided in the first memory array and the first wiring provided in the second memory array are shared. The magnetic memory according to claim 2. 4. In each of the first and second memory arrays, the plurality of magnetoresistive effect elements arranged in the matrix form have a magnetic recording layer formed in the first shape. 4. The magnetic material according to claim 2, wherein the magnetic field effect layer and the magnetoresistive effect element having a magnetic recording layer formed in a second shape different from the first shape are alternately arranged. memory. 5. The magnetic recording layer is formed asymmetrically with respect to the major axis of at least one of the first and second wirings.
Magnetic memory described in 1. 6. The magnetic memory according to claim 1, wherein an angle at which the first wiring and the second wiring intersect each other is other than 90 degrees. 7. The magnetic recording layer has a ratio L / D of a width D to a length L of greater than 1.2, and is provided with uniaxial anisotropy along the direction of the length L. The magnetic memory according to any one of claims 1 to 6, characterized in that: 8. The magnetic device according to claim 1, wherein at least one of the first and second wirings has a coating layer made of a soft magnetic material on a side surface thereof. memory. 9. A first memory array having a plurality of magnetoresistive effect elements arranged in a matrix, and a plurality of magnetoresistive effect elements stacked on the first memory array and arranged in a matrix. A second memory array having: a first wiring extending below the magnetoresistive effect element and a magnetoresistive effect element of each of the first and second memory arrays; A second wiring extending above in a direction intersecting the first wiring, and arranged between them by a magnetic field formed by passing a current through the first and second wirings. The magnetization of the magnetic recording layer of the magnetoresistive effect element can be inverted, and the second wiring provided in the first memory array and the first wiring provided in the second memory array. Wiring is common And a magnetic memory, wherein a coating layer made of a soft magnetic material on its side is provided.