JP2007096074A - Magnetic memory - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic memory capable of decreasing a write current while suppressing miswriting. <P>SOLUTION: The magnetic memory includes a first wire 20, a second wire 30 in crossing with the first wire, and a magneto-resistance effect element 1. The magneto-resistance effect element includes a magnetization fixed layer 4 the direction of magnetization of which is fixed; and a magnetization free layer 2 including at least two or more magnetic layers 2<SB>1</SB>, 2<SB>2</SB>each of planar shape of which comprises a main body 2a the size in the axial direction of easy magnetization is longer than the size in the axial direction of hard magnetization and projections 2b provided in the axial direction of hard magnetization in the middle of the main body 2a, and a nonmagnetic layer 2<SB>3</SB>located between the magnetic layers 2<SB>1</SB>, 2<SB>2</SB>, and the direction of the magnetization of the magnetic layers of which varies with an external magnetic field. The magneto-resistance effect element is arranged in such a way that the direction of the axis of easy magnetization of the magnetization free layer is tilted with respect to the first and second wires, and a ratio of the length in the axial direction of hard magnetization to the length in the axial direction of easy magnetization in each of the magnetic layers of the magnetization free layer is greater than 1 and equal to or less than 1.5. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a magnetic memory having a magnetoresistive effect element in a memory cell.

  2. Description of the Related Art Recently, a magnetic random access memory (MRAM) using a tunnel magnetoresistance (TMR) effect has been proposed as a kind of semiconductor memory.

  In the memory cell of this MRAM, an MTJ (Magnetic Tunneling Junction) element, which is a kind of magnetoresistive effect element, is provided as an information storage element in an intersection region between a bit line and a word line. In this MRAM, when data is written, currents are supplied to the selected bit line and the selected word line, respectively, and the MTJ of the selected memory cell located in the intersection region of the selected bit line and the selected word line is generated by a combined magnetic field generated by these currents. Data is written to the element. On the other hand, when reading data, a read current is supplied to the MTJ element of the selected memory cell, and data “1” and “0” are read by the resistance change in the magnetization state of the MTJ element.

  In such an MRAM, when data is written, a write current magnetic field affects a memory cell in which only one of a selected bit line and a selected word line is selected, that is, a half-selected cell. For this reason, there may occur a problem that erroneous writing occurs in the half-selected cell. Avoiding this problem is considered one of the most important issues in MRAM development.

Therefore, as one of the solutions to the above problem, a toggle type MRAM using a recording layer having two magnetic layers antiferromagnetically coupled via a nonmagnetic layer has been proposed (for example, Patent Document 1). reference). However, this toggle type MRAM has a problem that the write current value becomes unrealistically large as a general-purpose memory.
US Pat. No. 6,545,906

  As described above, in the conventional MRAM, it is difficult to reduce the write current while suppressing erroneous writing.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a magnetic memory capable of reducing a write current while suppressing erroneous writing.

A magnetic memory according to one aspect of the present invention includes a first wiring, a second wiring that intersects the first wiring, and a magnetoresistor provided corresponding to an intersecting region of the first and second wirings. An effect element,
The magnetoresistive effect element is
A magnetization pinned layer in which the magnetization direction is fixed;
Each planar shape has at least two or more magnetic layers having a main body portion whose easy axis direction is longer than the hard axis direction and a projecting portion provided in the hard axis direction at the center of the main body portion; A non-magnetic layer provided between each magnetic layer, and a magnetization free layer in which the magnetization direction of the magnetic layer is variable by an external magnetic field,
The magnetoresistive effect element is arranged such that the direction of the easy magnetization axis of the magnetization free layer is inclined with respect to the first and second wirings,
Each of the magnetic layers of the magnetization free layer is characterized in that the ratio of the length in the easy axis direction to the length in the hard axis direction is greater than 1 and 1.5 or less.

  The inclination angle of the magnetization easy axis of the magnetization free layer with respect to the first and second wirings may be substantially 45 degrees.

  In addition, each of the magnetic layers of the magnetization free layer preferably has a ratio of the length in the easy axis direction to the hard axis direction in the range of 1 to 1.33.

  Each magnetic layer of the magnetization free layer may have a sharp junction between the main body portion and the protruding portion.

  The corners of each magnetic layer of the magnetization free layer may be rounded.

  In addition, each magnetic layer of the magnetization free layer may have a planar shape in which the length in the hard magnetization axis direction monotonously decreases from the center to the end.

  Note that the first and second wirings have a dimension in the width direction of the first or second wiring of the magnetoresistive effect element that is disposed to be inclined with respect to the first and second wirings. The width may be in the range of -10% to + 10%.

  According to the present invention, it is possible to reduce a write current while suppressing erroneous writing.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1A is a plan view of the magnetic memory cell according to the first embodiment of the present invention, and FIG. The magnetic memory of the present embodiment is a toggle type magnetic memory, and has a plurality of memory cells. Each memory cell includes a word line 20 and a bit line 30 substantially orthogonal to the word line 20. The magnetoresistive effect element 1 disposed in the intersecting region is provided. The magnetoresistive element 1, as shown in FIG. 2, has a non-magnetic metal layer 2 ₃ via the antiferromagnetically coupled magnetic layer 2 _1, 2 _2, the magnetization direction (magnetic moment in response to an external magnetic field ) Is a magnetic recording layer that changes, a magnetization fixed layer 4 in which the magnetization direction is fixed, a tunnel barrier layer 3 provided between the magnetization free layer 2 and the magnetization fixed layer 4, An antiferromagnetic layer 5 that fixes the magnetization direction of the magnetization pinned layer 4. The magnetoresistive element 1 is provided with the direction of magnetization of the magnetization pinned layer 4, close to the magnetization pinned layer 4, a tunnel conductance through the tunnel barrier by the relative angle between the magnetic layer 2 ₂ of the magnetization direction of the magnetization free layer 2 Changes. 2 has a single tunnel junction structure, it may be a magnetoresistive element 1 having a double tunnel junction structure as shown in FIG. The magnetoresistive effect element 1 having this double tunnel junction structure is provided with a tunnel barrier layer 6 on the side opposite to the tunnel barrier layer 3 of the magnetization free layer 2 of the magnetoresistive effect element of the single tunnel junction shown in FIG. A magnetization pinned layer 7 is provided on the side of the barrier layer 6 opposite to the magnetization free layer 2, and an antiferromagnetic layer 8 is provided on the side of the magnetization pinned layer 7 opposite to the tunnel barrier layer 6 to pin the magnetization direction of the magnetization pinned layer 7. It becomes the composition.

  Then, as shown in FIG. 4, the planar shape of the magnetization free layer 2 of the magnetoresistive effect element 1 has a main body portion 2a in which the easy axis direction is longer than the hard axis direction, and the magnetization arranged substantially at the center. And a protruding portion 2b protruding in the difficult axis direction. In the present embodiment, the ratio (= a / b) of the length a (= 540 nm) in the easy axis direction of the magnetization free layer 2 to the length b (= 360 nm) in the hard axis direction is 1.5. is there. In the present embodiment, the planar shape of each magnetic layer of the magnetization free layer 2 is configured such that the length in the hard axis direction monotonously decreases from the center to the end. The protrusion 2b may be symmetric with respect to the easy magnetization axis as shown in FIG. 4 or may be asymmetric. This is because in the toggle method, the rotation direction of the magnetic moment is limited to one direction, so even if the top and bottom are asymmetrical, the rotation of the magnetic moment changes from 0 to 1 even when the data changes from 1 to 0. But it is exactly the same. Further, the easy axis of magnetization of the magnetization free layer 2 of the magnetoresistive effect element 1 is arranged so as to form an angle of substantially 45 degrees with the word line 20 and the bit line 30 as shown in FIG.

The result of calculating the toggle-type writing of the magnetic memory according to the present embodiment using an LLG (Landau-Lifsiz-Gilbert) simulation will be described with reference to FIGS. Incidentally, magnetization free layer 2 of the upper and lower magnetic layer ₂ 1, _{2 2} of the thickness was 3 nm, the magnetic layer ₂ 1, ₂ is between ₂ non-magnetic layer _{2 3} The thickness of 2 nm, an antiferromagnetic coupling constant Assumed 0.02 erg / cm ² . In this simulation, the magnetic field was calculated using a static magnetic field simulator. 5 shows a write current pulse of the bit line 30 and the word line 20 used for writing. FIG. 6 shows one of the magnetization free layers 2 when the current pulse shown in FIG. (for example, in Figure 2, left) magnetic layer 2 _2-way shows the time variation of the normalized magnetic moment Mx of. The magnetic moment of the pinned layer 4 before passing current pulses directed to the right as shown in FIG. 2, the orientation of the magnetic moment of the magnetic layer 2 ₂ of the magnetization free layer 2 left in FIG. 2, i.e., the magnetization pinned layer the fourth magnetic moments are oriented to differ substantially 180 degrees, substantially the same orientation direction of the magnetic moment of the magnetic layer 2 ₁ is the right side in FIG. 2, i.e., the magnetic moment of the pinned layer 4 It has become. In this state, at time t _0, when an electric current is applied to the word line 20, the one direction of the magnetic moment of the magnetic layer 2 ₂ of the magnetization free layer 2 is reduced. That is, the orientation of the magnetic moment of the magnetic layer 2 ₂ begins to rotate. Then, the current flowing through the word line is reached at time t ₁ to a predetermined current value, maintaining the predetermined current value to the time t _2, the during the above one direction of the magnetic field and the magnetic layer 2 ₂ generated by this current the direction of the magnetic moment perpendicular are balanced, the one direction of the magnetic moment of the magnetic layer 2 ₂ is maintained at a constant value. That is, the rotation of the magnetic moment of the magnetic layer 2 ₂ stops. When the time t ₂ begins to conduct current to the bit line 30, the one direction of the magnetic moment of the magnetic layer 2 ₂ is even smaller, it begins to rotate again. This rotation until time t ₃ when the current flowing through the bit line 30 reaches a predetermined value, continues. And the one direction of the magnetic moment of the magnetic layer 2 ₂ between times t ₃ from time t ₂ 0, and the passes through the hard-axis direction. During the time t ₃ the time t _4, since the current flowing through the word line 20 and bit line 30 has a predetermined value, the magnetic field and the magnetic layer by the current flowing through the word line 20 and bit line 30 2 ₂ magnetic moment balancing, the one direction of the magnetic moment of the magnetic layer 2 ₂ is maintained at a constant value, the rotation of the magnetic moment of the magnetic layer 2 ₂ stops. And from time t ₄ to time t _5, although the current flowing through the bit line 30 remains at a predetermined value, when a current flowing through the word line 20 is decreased to 0 from a predetermined value, the magnetic layer 2 ₂ of the one-way the magnetic moment is reduced further, the magnetic moment of the magnetic layer 2 ₂ starts rotating again. Since the magnitude of the current of a predetermined value only from time t ₅ to the bit line 30 to time t ₆ is flowing, and the direction of the magnetic moment perpendicular to the one direction of the magnetic field and the magnetic layer 2 ₂ generated by this current balancing, the one direction of the magnetic moment of the magnetic layer 2 ₂ is maintained at a constant value, the rotation of the magnetic moment of the magnetic layer 2 ₂ stops. Period from the time t ₆ to time t _7, when a current flowing through the bit line 30 decreases to 0 from a predetermined value, the one direction of the magnetic moment of the magnetic layer 2 ₂ decreases further, the magnetic moment of the magnetic layer 2 ₂ rotation, the magnetic moment of the magnetic layer 2 ₂ immediately before time t ₀ and substantially 180 ° from the direction of the magnetic moment again. That is, the magnetic layer 2 ₂ of the magnetization direction immediately before time t ₀ will be inverted. In the above process, the magnetic layer 2 ₁ since antiferromagnetically coupled to the magnetic layer 2 _2, the magnetization direction of the magnetic layer 2 ₁ is rotated together with the magnetization direction of the magnetic layer 2 _2.

Thereafter, the flow again current pulses shown in FIG. 5 to the word line 20 and bit line 30, the one direction of the magnetic moment of the magnetic layer 2 ₂ to increase from -1 to +1, the magnetic moment of the magnetic layer 2 ₂ rotated, finally, a magnetic layer 2 ₂ of the magnetic moment substantially the same direction of the magnetic moment immediately before time t ₀ (see the right side of the graph in FIG. 6).

FIG. 7 shows a result of simulating whether or not the magnetic moment of the magnetization free layer is reversed by changing the magnitude of the current passed through the word line 20 and the bit line 30 in the present embodiment. Horizontal axis represents current I _B flowing through the bit line 30, it vertical axis represents the magnitude of the current flowing through the word lines I _W, the symbol "○" indicates that the inverted symbol "×" as not inverted Is shown. In this embodiment in which the ratio (= a / b) of the length a in the easy axis direction of the magnetization free layer 2 to the length b in the hard axis direction is 1.5, as can be seen from FIG. If the current passed through the word line 20 and the bit line 30 is 10 mA or more, the magnetic moment of the magnetization free layer 2 is reversed, and if it is less than 10 mA, it is not reversed. It can be seen that no reversal occurs even when a current is supplied to only one of the word line 20 and the bit line 30.

  Next, as shown in FIG. 8, when the planar shape of the magnetization free layer 2 is a rectangle, that is, when there is no protrusion in the hard axis direction, the same magnetic memory as in this embodiment is used as a comparative example. FIG. 9 shows a result of simulating whether or not the magnetic moment of the magnetization free layer is reversed by passing the current shown in FIG. 5 through the word line and the bit line as an example. The ratio (= a / b) of the length a (= 720 nm) of the long side of the planar shape of the magnetization free layer 2 shown in FIG. 8 to the length b (= 240 nm) of the short side is 3. As can be seen from FIG. 9, in this comparative example, if the current flowing through the word line 20 and the bit line 30 is 14 mA or more, the magnetic moment of the magnetization free layer 2 is reversed, and if it is 13 mA or less, it is not reversed.

  As described above, according to the present embodiment, the write current can be reduced. Further, since it is a toggle type magnetic memory, erroneous writing can be suppressed.

(Second Embodiment)
Next, a magnetic memory according to a second embodiment of the present invention will be described with reference to FIGS. The magnetic memory of this embodiment is the same as the magnetic memory of the first embodiment, except that the planar shape of the magnetization free layer 2 is the shape shown in FIG. That is, the planar shape of the magnetization free layer 2 includes a main body portion 2a in which the easy axis direction is longer than the hard axis direction, and a protruding portion 2b that protrudes in the hard axis direction and is disposed substantially at the center. The ratio (= a / b) of the length a (= 480 nm) in the easy axis direction to the length b (= 360 nm) in the hard axis direction is 1.33. The configuration is the same as that of the first embodiment except for the planar shape of the magnetization free layer 2.

In the present embodiment, (For example, in FIG. 2, left) direction magnetization of the free layer 2 of the magnetic layer 2 ₂ when two swirling flow to a word line and a bit line of a set of current pulses shown in FIG. 5 is normalized FIG. 11 shows the time change of the magnetic moment Mx. As can be seen from FIG. 11, as in the first embodiment, the magnetization moment of the magnetization free layer 2 is rotated 180 degrees by the first set of current pulses and further rotated 180 degrees by the next set of current pulses. And back.

Further, FIG. 12 shows the result of simulating whether or not the magnetic moment of the magnetization free layer is reversed by changing the magnitude of the current passed through the word line 20 and the bit line 30 in this embodiment. Horizontal axis represents current I _B flowing through the bit line 30, it vertical axis represents the magnitude of the current flowing through the word lines I _W, the symbol "○" indicates that the inverted symbol "×" as not inverted Is shown. The ratio of the length a in the easy axis direction to the length b in the hard axis direction (= a / b) is 1.33. In this embodiment, as shown in FIG. 12, the word line 20 and the bit If the current passed through the line 30 is 7 mA or more, the magnetic moment of the magnetization free layer 2 is reversed, and if it is smaller than 7 mA, it is not reversed. It can be seen that no reversal occurs even when a current is supplied to only one of the word line 20 and the bit line 30. As described above, even if a current is supplied to only one of the word line 20 and the bit line 30, the magnetic moment cannot be reversed and erroneous writing does not occur, so that a large write margin can be obtained. As a result of examining the magnetization pattern at the time of magnetization reversal, the magnetization reversal occurred simultaneously, and a complicated magnetic domain structure such as a C-type magnetic domain is not taken.

  As described above, the magnetic memory of this embodiment has a lower current for reversing the magnetic moment of the magnetization free layer than the magnetic memory of the first embodiment. Therefore, it is necessary to reverse the magnetic moment of the magnetization free layer when the ratio (= a / b) of the length a in the magnetization easy axis direction a and the length b in the magnetization difficult axis direction of the magnetization free layer 2 is changed. FIG. 13 shows the result of obtaining a simple current (reversal current) by simulation. As can be seen from FIG. 13, when the ratio a / b is greater than 1.33, the inversion current is also increased. In FIG. 13, the data with the ratio a / b of 3 is for the first embodiment, and the data with the ratio a / b of 3 is for the case where the planar shape of the magnetization free layer 2 is the rectangle shown in FIG. . Therefore, if the ratio a / b is greater than 1 and 1.5 or less, the inversion current, that is, the write current can be reduced. The ratio a / b is more preferably greater than 1 and less than or equal to 1.33.

  Next, in this embodiment, FIG. 14 shows the change of the inversion current when the wiring width of the word line 20 and the bit line 30 is changed without changing the size and shape of the magnetization free layer of the magnetoresistive effect element. In this embodiment, the reversal current is minimized when the wiring width of the word line 20 and the bit line 30 is 460 nm. A plan view at this time is shown in FIG. In other words, the magnetoresistive effect element is disposed at a substantially 45 ° inclination with respect to the word line 20 and the bit line 30. Further, the corner portions of the magnetoresistive element that are opposed to the diagonal direction substantially coincide with the side surfaces of the word line 20 and the bit line 30, and the magnetoresistive element is the word line 20 and the bit line 30. The reversal current is at a minimum when it is covered without excess or deficiency. In the present specification, the length between the corners opposed to the direction of the diagonal line of the main body part of the magnetoresistive effect element is referred to as the length of the diagonal line of the magnetoresistive effect element.

  In the toggle type magnetic memory, in order to reverse the magnetization (magnetic moment) of the magnetic layer of the magnetization free layer, the magnetization of each magnetic layer needs to move all at once. However, when the wiring width of the word line and the bit line becomes narrower than the length 460 nm of the diagonal line of the magnetoresistive effect element disposed substantially inclined by 45 degrees with respect to the word line 20 as shown in FIG. The magnetization of only a part of the layer tends to rotate preferentially, but since the magnetization of the magnetic layer needs to be rotated for reversal, the reversal current increases (see FIG. 14). Further, when the wiring width of the word line and the bit line becomes larger than the length of the diagonal line of the magnetoresistive effect element, 460 nm, the magnetization free layer 2 moves away from the magnetic field caused by the current flowing through the word line or the bit line, and therefore, the inversion current is also reduced. growing. From the above, if the width of the word line and the bit line is in the range of −10% to + 10% of the length of the diagonal line of the magnetoresistive element (460 nm (see FIG. 15 in this embodiment)), it is inverted. The current (write current) can be reduced.

  As described above, according to the second embodiment, it is possible to reduce the write current while suppressing erroneous writing.

  In each embodiment of the present invention, it is important to pattern the magnetization free layer into a desired shape. If an element having a size of about 0.1 μm is produced, photolithography can be used. If a photomask that takes the proximity effect into consideration in accordance with the wavelength to be used is prepared, the final exposed shape can be made desired.

In order to sharpen the joint between the protrusion and the main body, as shown in FIGS. 16A and 16B, a two-step method of patterning the mask in two steps is effective. That is, the main body 2 a is patterned using the first mask 51. Then, after selectively forming a thin side wall around the patterned main body, and then patterning the side wall using the second mask 52 to form a protruding portion, the crossing portion of both is very sharp. Become. At this time, it is important to select a material having a large selection ratio with respect to the hard mask for the stopper layer below the hard mask material. If processing is performed using RIE using Ta for etching the hard mask, Al for the stopper layer, and introducing the etching gas CF ₄ , a selection ratio of usually 10 or more can be obtained. Alternatively, a hard mask pattern made of Ta may be transferred to the main body, a resist pattern corresponding to the protruding portion may be provided on the stopper layer, and the stopper layer may be processed using the resist pattern and the hard mask.

  In each of the embodiments described above, the planar shape of the magnetic layer of the magnetization free layer may be such that the joint portion between the main body portion and the projecting portion is rounded outward or has a curved shape constricted inward. May be. Further, the planar shape of the magnetic layer of the magnetization free layer may be a cross shape. The corners of the magnetic layer of the magnetization free layer may be rounded.

  In each of the above embodiments, the planar shape of the magnetization pinned layer may be the same as or different from the planar shape of the magnetization free layer.

  In addition, the data of the magnetic memory of the above embodiment can be read by the method described in Patent Document 1 described in the background art.

  As described above, according to each embodiment of the present invention, it is possible to provide a toggle type magnetic memory capable of reducing a magnetic field necessary for magnetization reversal and reducing a magnetization reversal current. Therefore, in the magnetic memory according to each embodiment of the present invention, power consumption can be reduced and a wide write margin can be obtained.

The figure which shows the structure of the magnetic memory by 1st Embodiment of this invention. Sectional drawing which shows the structure of the magnetoresistive effect element used for each embodiment of this invention. Sectional drawing which shows the structure of the magnetoresistive effect element which has a structure of a tunnel double junction. The figure which shows the planar shape of the magnetization free layer of the magnetic memory by 1st Embodiment. The wave form diagram of the write current of the magnetic memory of 1st Embodiment. The figure which shows the time change of the one-way normalized magnetic moment Mx which comprises the magnetization free layer when the electric current shown in FIG. 5 is sent through the word line and bit line of 1st Embodiment. The figure which shows the result of having investigated whether the magnetic moment of the magnetization free layer at the time of changing the magnitude | size of the electric current added to the word line and bit line of the magnetic memory of 1st Embodiment is reversible. The figure which shows the planar shape of the magnetization free layer of the magnetic memory by the comparative example of 1st Embodiment. The figure which shows the result of having investigated whether the magnetic moment of the magnetization free layer at the time of changing the magnitude | size of the electric current added to the word line and bit line of the magnetic memory of a comparative example is reversible. The figure which shows the planar shape of the magnetization free layer of the magnetic memory by 2nd Embodiment of this invention. The figure which shows the time change of the unidirectional normalized magnetic moment Mx of one magnetic layer which comprises the magnetization free layer when the electric current shown in FIG. 5 is sent through the word line and bit line of 2nd Embodiment. The figure which shows the result of having investigated whether the magnetic moment of the magnetization free layer at the time of changing the magnitude | size of the electric current added to the word line and bit line of the magnetic memory of 2nd Embodiment is reversible. The figure which shows the change of a reversal current when changing the ratio of the length of the magnetization easy axis direction of a magnetization free layer, and the length of a magnetization difficult axis direction. The figure which shows the change of the inversion current at the time of changing the width of a word line and a bit line, without changing the size of a magnetoresistive effect element in 2nd Embodiment. The top view of the word line which has the optimal width | variety, and a magnetoresistive effect element in 2nd Embodiment. The figure explaining patterning of a magnetization free layer in 2nd Embodiment.

Explanation of symbols

1 Magnetoresistive element 2 Magnetization free layer (magnetic recording layer)
21, 22 Magnetic layer 23 Nonmagnetic layer 4 Magnetization pinned layer 5 Antiferromagnetic layer 20 Word line 30 Bit line

Claims (7)

A first wiring, a second wiring intersecting with the first wiring, and a magnetoresistive effect element provided corresponding to an intersection region of the first and second wirings,
The magnetoresistive effect element is
A magnetization pinned layer in which the magnetization direction is fixed;
Each planar shape has at least two or more magnetic layers having a main body portion whose easy axis direction is longer than the hard axis direction and a projecting portion provided in the hard axis direction at the center of the main body portion; A non-magnetic layer provided between each magnetic layer, and a magnetization free layer in which the magnetization direction of the magnetic layer is variable by an external magnetic field,
The magnetoresistive effect element is arranged such that the direction of the easy magnetization axis of the magnetization free layer is inclined with respect to the first and second wirings,
Each of the magnetic layers of the magnetization free layer is characterized in that the ratio of the length in the easy axis direction to the hard axis direction is greater than 1 and 1.5 or less.   2. The magnetic memory according to claim 1, wherein an inclination angle of the magnetization free axis direction of the magnetization free layer with respect to the first and second wirings is substantially 45 degrees.   3. The ratio of the length in the easy magnetization axis direction to the hard magnetization axis direction in each of the magnetic layers of the magnetization free layer is greater than 1 and less than or equal to 1.33. 3. Magnetic memory.   4. The magnetic memory according to claim 1, wherein each magnetic layer of the magnetization free layer has a sharp junction between the main body and the protrusion. 5.   5. The magnetic memory according to claim 1, wherein corners of the magnetic layers of the magnetization free layer are rounded.   6. The magnetism according to claim 1, wherein each magnetic layer of the magnetization free layer has a planar shape in which a length in a hard magnetization axis direction monotonously decreases from a central portion to an end portion. memory.   The width of the first and second wirings with respect to the dimension in the width direction of the first or second wiring of the magnetoresistive effect element arranged to be inclined with respect to the first and second wirings is The magnetic memory according to claim 1, wherein the magnetic memory is in a range of −10% to + 10%.

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