JP2003110165A - Magnetoresistance effect device, ferromagnetic substance memory, and information instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the characteristics of a memory layer such as the inversion of magnetization and the maintenance of the magnetization direction of the memory layer in a magnetoresistance effect device. SOLUTION: A memory magnetic layer 11 comprises a GdFe or GdFeCo alloy, so that a coercive force is set in an optimum manner with compositions of rare earth metal Gd and transition metals Fe, Co, and magnetization of the memory magnetic layer is made optimum with the composition of GdFe or GdFeCo and the film construction of the same. Further, a magnetoresistance effect device can be constructed with ease, in which an inverse magnetic field of the memory magnetic layer is reduced, and the direction of the magnetization is maintained stably by making the magnetization of a pin magnetic layer optimum with the aid of the composition and film construction of the pin magnetic layer 13 by constituting the pin magnetic layer 13 with a TbFe or TbFeCo alloy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetoresistive effect element for recording information by the direction of magnetization and reproducing it by a magnetoresistive effect, and a magnetic thin film memory using the same.

[0002]

2. Description of the Related Art A magnetoresistive effect element is also called a magnetic thin film memory element, and is a solid-state memory element having no moving part like a semiconductor memory. Moreover, there are advantages compared with semiconductor memory, such as that information is not lost even if the power is cut off, infinite rewriting is possible, and there is no risk of losing recorded contents even when radiation is incident. is there.

A ferromagnetic tunnel junction element, which is a magnetic thin film memory element utilizing the tunnel magnetoresistive effect, has a structure in which a tunnel barrier layer made of a thin insulator having a thickness of several nm is sandwiched between two ferromagnetic layers. To have. In a ferromagnetic tunnel junction element, when an external magnetic field is applied in the plane of the ferromagnetic layers with a constant current flowing between the two ferromagnetic layers, the resistance value changes according to the relative angle of magnetization of both ferromagnetic layers. The resistance effect phenomenon appears.

When the magnetization directions of the two ferromagnetic layers are parallel to each other, the resistance value of the ferromagnetic tunnel junction element becomes minimum. When the magnetization directions of the two ferromagnetic layers are antiparallel to each other, the resistance value of the ferromagnetic tunnel junction element becomes maximum.

If the two ferromagnetic layers have a difference in coercive force, parallel and anti-parallel states of magnetization can be realized according to the strength of the magnetic field. Information can be recorded by controlling the magnetization in parallel or antiparallel, and information can be reproduced by detecting the magnetization state by the change in resistance value.

In recent years, by using an Al surface oxide film for the tunnel barrier layer, a ferromagnetic tunnel junction element having a magnetoresistance change rate of nearly 20% has been obtained. Therefore, the possibility of applying the ferromagnetic tunnel junction element to a magnetic head or a magnetic memory is increasing.
As a representative example of the literature reporting such a large magnetoresistance change rate, “April 1996, Journal of Applied Physics, Vol. 79, 4724-4729.
Page (Journal of Applied Phys
ics, vol. 79, 4724-4729, 1
996). "

When the element size is reduced in order to increase the degree of integration of the magnetic thin film memory, the magnetoresistive effect element using the in-plane magnetized film has a magnetization direction of the ferromagnetic layer due to the influence of demagnetizing field or curling of magnetization at the end face. Cannot be recorded in a fixed direction, and information cannot be recorded.

In order to avoid this problem, if the shape of the ferromagnetic layer is made a rectangle long in the direction of the easy axis of magnetization, the size of the element cannot be reduced and the degree of integration cannot be increased.

Therefore, a ferromagnetic material that can maintain the magnetization direction constant even if the element size becomes small is disclosed in Japanese Patent Application Laid-Open No. 11-213650. There is a magnetic thin film memory using a ferromagnetic material having an axis, that is, a perpendicular magnetization film.

A magnetoresistive effect film using a perpendicularly magnetized film as described in Japanese Patent Application Laid-Open No. 11-213650 is shown in FIG.
As shown in (a), when the magnetization directions of the two ferromagnetic layers of the first ferromagnetic layer 51 and the second ferromagnetic layer 53 are the same direction (that is, parallel), the two ferromagnetic layers The resistance value is small. Further, as shown in FIG. 5B, if the magnetization directions of the two ferromagnetic layers are opposite to each other (that is, antiparallel), the resistance value between the two ferromagnetic layers is large.

The principle of a magnetoresistive film using a ferrimagnetic alloy of a rare earth metal and a transition metal as a perpendicular magnetization film will be described with reference to FIG.

In FIG. 6, the arrow in the white frame indicates the difference in magnetization between the rare earth element and the iron group element, that is, the net magnetization direction of the magnetic layer. Further, the solid arrow indicates the direction of magnetization of the iron group transition element. In the case of a ferrimagnetic film, the sublattice magnetization of each element is in the opposite direction.

Of these, the magnetism of the rare earth element is caused by 4f electrons. However, since these 4f electrons are deep inside the inner shell, they do not contribute much to electrical conduction. On the other hand, 3d electrons that contribute to the generation of magnetism of the iron group transition element are partly conduction electrons because they are close to the outer shell.

Therefore, the value of the magnetic resistance due to the difference in the direction of spin is easily influenced by the spin of the iron group transition element. Therefore, the spin direction due to the magnetic resistance can be seen by looking at the spin direction of the iron group element.
For example, as shown in FIG. 6A, when the magnetic moments of the iron group element are parallel between the first ferromagnetic layer 61 and the second ferromagnetic layer 63, the resistance is small, and FIG. ), The resistance is large when antiparallel.

In FIG. 6, the case where the net magnetization of each ferromagnetic layer and the magnetization of the iron group element are oriented in the same direction is the iron group element rich (TM rich). The ferromagnetic layer 61 may be rare earth element rich (RE rich), and the second ferromagnetic layer 63 may be TM rich, or may be the reverse configuration.

[0016]

In a magnetoresistive effect element made of an alloy material of these rare earth metals and transition metals and capable of reversing the magnetization of a memory magnetic layer by a magnetic field induced by a current flowing in a write line. It is desired to improve characteristics such as magnetization reversal of the memory layer and maintenance of the magnetization direction by applying an external magnetic field.

An object of the present invention is to improve characteristics such as magnetization reversal and maintenance of magnetization direction of a memory layer in a magnetoresistive effect element.

[0018]

In order to achieve the above object, the magnetoresistive effect element of the present invention comprises GdFe or Gd.
A memory magnetic layer made of a FeCo alloy and storing information according to the magnetization direction, and a memory magnetic layer made of TbFe or TbFeCo alloy, having a coercive force larger than that of the memory magnetic layer, and the magnetization direction of the memory magnetic layer changes even if the magnetization direction is changed. It has a pin magnetic layer that does not change and a non-magnetic insulating layer sandwiched between the memory magnetic layer and the pin magnetic layer.

Therefore, according to the present invention, by using GdFe or GdFeCo in the memory magnetic layer,
Small coercive force, rare earth metal Gd and transition metals Fe, Co
The coercive force is optimally set by the composition of GdF
The magnetization of the memory magnetic layer is optimized by the composition and film configuration of e or GdFeCo.

Further, according to the present invention, TbFe or TbFe having a coercive force larger than that of the material used for the memory magnetic layer is used.
TbFe or TbFeC using Co for the pin magnetic layer
By optimizing the magnetization of the pinned magnetic layer according to the composition of o and the film configuration, the magnetization direction of the pinned magnetic layer does not change under the memory driving conditions, and a magnetoresistive effect element with a small leakage magnetic field to the memory magnetic layer is easy. Can be configured to.

According to an aspect of the present invention, the memory magnetic layer has a thickness of 2 to 100 nm.

Therefore, the thickness of the memory magnetic layer is set to 2
By setting the thickness to ˜100 nm, it is possible to construct a magnetoresistive effect element having a small switching element magnetic field size in a practical range.

According to one aspect of the present invention, the pin magnetic layer has a thickness of 2 to 100 nm.

Therefore, the thickness of the pin magnetic layer is set to 2 to
By setting the thickness to 100 nm, a magnetoresistive effect element having a small element size can be formed.

Another magnetoresistive effect element of the present invention is GdF.
a magnetic memory layer made of e or GdFeCo alloy and storing information according to the magnetization direction, and TbFe or TbFe
A laminated film made of a Co alloy and a GdFe or GdFeCo alloy, having a coercive force larger than that of the memory magnetic layer,
It has a pinned magnetic layer whose magnetization direction does not change even when the magnetization direction of the memory magnetic layer is changed, and a non-magnetic insulating layer sandwiched between the memory magnetic layer and the pinned magnetic layer.

Therefore, TbFe or TbFeCo
Since the pinned magnetic layer is composed of the laminated film made of the alloy and the GdFe or GdFeCo alloy, the reversal magnetic field of the memory magnetic layer can be controlled to be further low.

According to one aspect of the present invention, the GdFe or GdFeCo alloy forming the pinned magnetic layer and TbF are used.
The e or TbFeCo alloy is magnetically coupled through a non-magnetic layer provided between them.

According to one aspect of the present invention, at least one of the memory magnetic layer and the pin magnetic layer is an amorphous film.

The ferromagnetic memory of the present invention has a plurality of magnetoresistive effect elements according to any one of the present invention, each magnetoresistive effect element, and an electric field effect connected to each of the magnetoresistive effect elements. A 1-bit memory cell is configured with the transistor.

Another ferromagnetic memory of the present invention has a plurality of magnetoresistive effect elements according to any one of the present invention, and is connected to each of the magnetoresistive effect elements and each of the magnetoresistive effect elements. The formed diode constitutes a 1-bit memory cell.

The information equipment of the present invention is any one of the present invention.
It has two ferromagnetic memories as built-in memory.

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view showing the structure of the magnetoresistive effect element of this embodiment. Referring to FIG. 1, the magnetoresistive effect element 10 of the present embodiment includes a memory magnetic layer 11, an insulating layer 12 and a pin magnetic layer 13.

The memory magnetic layer 11 has an optimum film thickness of GdF.
It is a layer of e or GdFeCo and has an easy axis of magnetization in the direction perpendicular to the film surface and records information by the direction of magnetization. Among ferrimagnetic materials having perpendicular magnetization characteristics, the GdFe or GdFeCo material has a relatively small coercive force, and the coercive force can be controlled by the composition of the rare earth metal Gd and the transition metals Fe and Co. Membrane memory magnetic layer 1
Suitable as 1. In addition, the amorphous state is preferable because the grain boundaries do not exist and the magnetization is easily oriented vertically. This can be created by appropriately selecting the conditions during film formation.

The insulating layer 12 is a thin layer of Al ₂ O ₃ ,
Allow tunnel current.

The pinned magnetic layer 13 is made of TbFe having an optimum film thickness.
Alternatively, it is a layer of TbFeCo and has a coercive force larger than that of the memory magnetic layer 11, and is controlled so that the magnetization direction does not change in a normal memory operating condition. As a ferrimagnetic material having a coercive force larger than that of the memory magnetic layer 11, TbFe or TbF is used.
By using the eCo material, the pinned magnetic layer 13 whose magnetization direction does not change under the driving conditions of the magnetic thin film memory can be easily obtained. In addition, the amorphous state is preferable because the grain boundaries do not exist and the magnetization is easily oriented vertically. This can be created by appropriately selecting the conditions during film formation.

The resistance value of the magnetoresistive effect element 10 depends on the film thickness of the thin insulating layer 12, and if the element size is reduced, the cross-sectional area of the element decreases and the element resistance increases. In order to maintain the operation time of the magnetoresistive effect element 10 even if the element size becomes small, it is necessary to further reduce the thickness of the insulating layer 12 according to the element size and suppress an increase in element resistance.

When the insulating layer 12 becomes thin, the magnetostatic coupling force between the ferromagnetic layers arranged above and below the insulating layer 12 becomes strong, and it becomes difficult to realize the antiparallel state of the magnetization. Therefore, the insulating layer 12 is thin. Also in this case, in order to realize the antiparallel state of the magnetization, the magnetization of the ferromagnetic layers, particularly the magnetization of the pinned magnetic layer 13 should be reduced in order to reduce the magnetostatic coupling force between the upper and lower ferromagnetic layers. Is preferred.

In the ferrimagnetic material, there is a compensating composition in which the magnetization becomes almost zero depending on the composition of the rare earth metal and the transition metal. Therefore, the magnetization can be set to the optimum size by selecting the composition. Further, since the magnetization is proportional to the volume of the magnetic substance, the magnetization can be adjusted by simply controlling the film thickness.

As the pinned magnetic layer 13 whose magnetization direction does not change, terbium (Tb) and transition metal (F) having a large coercive force are used.
e, Co) alloy is used. Pin magnetic layer 13
Requires that the magnetization direction does not change, and TbFe and TbFeCo having a coercive force of several kOe are suitable.

However, if the magnetization of the pinned magnetic layer 13 is large, as described above, the magnetostatic coupling between the pinned magnetic layer 13 and the memory magnetic 11 layer becomes strong, and the magnetic field required for the magnetization reversal of the memory magnetic layer 11 is increased. Therefore, it is desirable that the magnetization be small.

If the composition of terbium is a compensating composition,
It is possible to make the magnetization of the pinned magnetic layer 13 zero, but in reality, 19 at% to 27 at% near the compensation composition.
%, The magnetization per unit volume is 100 em
u / cm ³ or less, and further, the pin magnetic layer 13
Is adjusted within the range of 2 to 100 nm, the magnitude of magnetization of the pinned magnetic layer 13 is adjusted to be equal to or less than the coercive force of the memory magnetic layer 11.

On the other hand, when TbFe or TbFeCo is used as the compensating composition, the magnetization of Tb and the magnetization of Fe or FeCo are antagonized, and the magnetization reversal becomes difficult to occur. Therefore, when it is necessary to align the magnetization directions of the pinned magnetic layers 13 when used as a memory, a large magnetic field must be applied from the outside.

Therefore, by using a laminated film of GdFe or GdFeCo having a small magnetization and TbFe or TbFeCo having a magnetization of an appropriate size as the pinned magnetic layer 13, the leakage magnetic field to the memory magnetic layer 11 is reduced, It is possible to reduce the offset magnetic field of the memory magnetic layer 11 and set the magnitude of the external magnetic field required for initialization for aligning the magnetization direction of the pinned magnetic layer 13 in a fixed direction to an optimum value.

On the other hand, the memory magnetic layer 11 in which the magnetization is inverted under the driving conditions of the magnetic thin film memory preferably has a small coercive force of 100 (Oe) or less, and gadolinium (Gd).
And transition metal (Fe, Co) alloys are used. Also,
In order to invert the magnetization direction of the memory magnetic layer 11 by applying an external magnetic field and to maintain the magnetization direction stably, it is desirable that the memory magnetic layer 11 has an appropriate magnitude of magnetization, and the magnetization becomes zero in the operating temperature region. It is necessary that it does not match the compensation composition. In other words, the magnetization of the memory magnetic layer 11 is adjusted by controlling the composition of gadolinium (Gd) and the transition metal (Fe, Co) so as not to be the compensating composition and setting the thickness within the range of 2 to 100 nm.

Next, the operation of the magnetoresistive effect element 10 of the present invention will be described.

FIG. 2 shows a magnetoresistive effect element 1 of this embodiment.
FIG. 6 is a circuit configuration diagram for explaining an information recording operation in a magnetic thin film using 0. The magnetic thin film memory is also called a ferromagnetic memory.

Referring to FIG. 2, the ferromagnetic memory of the present embodiment has a write drive circuit 21 and a magnetoresistive effect element r.
11, r12, r13, r21, r22, r23, r3
1, r32, r33, field effect transistors t11, t
12, t13, t21, t22, t23, t31, t3
2, t33, Tw11, Tw12, Tw13, Tw1
4, Tw21, Tw22, Tw23, Tw24, Tw3
1, Tw32, Tw33, Tw34, Ts1, Ts2
Ts3, Tb11, Tb12, Tb21, Tb22, T
b31, Tb32, sense amplifiers SA1, SA2, SA
3, bit lines BL1, BL2, BL3, word line WL
1, WL2, WL3 and write lines WWL1, WWL
2 and WWL3.

Magnetoresistive effect elements r11, r12, r1
3, r21, r22, r23, r31, r32, r33
And field effect transistors t11, t12, t13, t
A memory cell array is composed of 21, t22, t23, t31, t32, and t33. A memory cell is composed of each magnetoresistive effect element and the corresponding field effect transistor.

Write lines WWL1, WWL2, WWL3
The bit lines BL1, BL2, BL3 are controlled, and information is written in a desired magnetoresistive effect element by the current flowing from the write drive circuit 21 to each wiring.

The word line WL1 is controlled, and the information recorded as the magnetization state in the selected magnetoresistive effect element is detected by the sense amplifier via the bit line.

Magnetoresistive elements r11, r12, r1
3, r21, r22, r23, r31, r32, r33
Is a thin aluminum oxide film having a thickness of 0.5 to 2 nm,
This structure is sandwiched between a GdFeCo memory magnetic layer, which is a ferrimagnetic material having an easy axis of magnetization in the vertical direction (thickness direction), and a TbFeCo pin magnetic layer.

Information is recorded as the magnetization direction of the memory magnetic layer. Since the magnetization direction of the memory magnetic layer is preserved unless an external magnetic field higher than the reversal magnetic field is applied, it operates as a non-volatile memory. For reading, the tunnel current value flowing through the aluminum oxide film is different depending on whether the magnetizations of the two magnetic layers are in the same direction (parallel) or in opposite directions (antiparallel). To do.

The field effect transistors t11, t12,
t13, t21, t22, t23, t31, t32, t
33 drain terminals and the corresponding magnetoresistive elements r11, r12, r13, r21, r22, r2
One terminal of 3, r31, r32, and r33 is connected.

Further, the field effect transistors t11, t
12, t13, t21, t22, t23, t31, t3
2, the gate terminals of t33 are corresponding word lines WL1, W
It is connected to L2 and WL3, and the source terminal is grounded. Further, the magnetoresistive effect elements r11, r12, r13,
The other terminals of r21, r22, r23, r31, r32, r33 are connected to the corresponding bit lines BL1, BL2, BL3.

Field effect transistors Tw11 and Tw1
2, Tw13, Tw14, Tw21, Tw22, Tw2
3, Tw24, Tw31, Tw32, Tw33, Tw3
Reference numeral 4 denotes a switching element, and when field-effect transistors (eg, Tw21 and Tw24) diagonally connected to the same write line are simultaneously turned on, a current flows in the corresponding write line (eg, WWL2), and A vertical magnetic field is applied to the magnetoresistive effect element adjacent to the write line. In FIG. 2, the field effect transistor Tw2
1, T24 and the write line WWL2 are indicated by thick lines.

Field effect transistors Tb11 and Tb1
2, Tb21, Tb22, Tb31, Tb32 are switching elements, and when field effect transistors (eg, Tb21 and Tb22) at both ends of the bit line are turned on at the same time, a current flows in the corresponding bit line (eg, BL2), An in-plane magnetic field is applied to the magnetoresistive effect element connected to the bit line.

The magnetization of the memory magnetic layer of the magnetoresistive effect element to which the perpendicular and in-plane magnetic fields are simultaneously applied becomes reversible, and the write operation is performed.

FIG. 3 shows a magnetoresistive effect element 1 of this embodiment.
FIG. 6 is a circuit configuration diagram for explaining an information reading operation in a ferromagnetic memory using 0. Referring to FIG. 3, it differs from FIG. 2 in that a read drive circuit 31 is shown.

Here, the operation for reading the information recorded in the magnetoresistive effect element r22 will be described as an example.

With a constant current flowing through the bit line BL2 by the read drive circuit 31 connected to the bit line BL2, a voltage is applied to the word line WL2, the field effect transistor T22 is turned on, and the potential of the bit line BL2 is turned on. To the sense amplifier SA2. With the sense amplifier SA2,
The input potential of the bit line BL2 is compared with the reference potential Ref.

Since the potential of the bit line BL2 changes depending on the resistance value of the magnetoresistive effect element r22, that is, information, the sense amplifier SA2 can detect information. If the potential of the bit line BL2 is high, the magnetization directions of the two magnetic layers forming the magnetoresistive effect element r22 are antiparallel to each other, and if the potential is low, they are parallel to each other.

Specific examples will be described. (Example 1) As a pinned magnetic layer in which the magnetization direction in the magnetoresistive effect element having an easy axis of magnetization in the direction perpendicular to the film surface is not changed, the composition of Tb is set to about 23% which is a compensation composition, and T
bFeCo was formed by sputtering. As a result, the magnetization per unit volume of the pinned magnetic layer was about 20 emu / cm ³ or less, although it varied somewhat depending on the film forming conditions.

Therefore, the film thickness of TbFeCo to be the pinned magnetic layer was set to 10 nm. A 1.5 nm thick Al ₂ O ₃ layer was formed as a tunnel insulating layer on this layer.

Next, as a memory magnetic layer, GdFeCo was sputter-deposited with a thickness of 20 nm with the composition of Gd being set to about 22% at which the transition metal magnetization was dominant over the compensation composition with zero magnetization. The magnetization per unit volume of the memory magnetic layer was in the range of about 20 emu / cm ³ or more and 50 emu / cm ³ or less, and stable magnetization reversal and memory retention were obtained.

The coercive force of the memory magnetic layer is 50 O
Since the leakage magnetic field from the pinned magnetic layer to the memory magnetic layer was 5 Oe or less, the influence of the leakage magnetic field on the characteristics was negligible.

Since good characteristics could be obtained by this composition and film structure, a memory cell was manufactured as an example using this structure.

FIG. 4 is a sectional view showing the structure of a memory cell manufactured as a specific example of the present invention. As shown in FIG. 4, on a p-type silicon substrate 41, a buried element isolation region 43 made of SiO ₂ , an n-type diffusion region 421 and a n-type diffusion region 421 serving as a drain and a source of a field effect transistor functioning as a switching element are formed. Diffusion area 4
20, a SiO ₂ gate insulating film 422, and a polysilicon gate electrode 423 were formed.

Further, electric power is supplied through the TiN local wiring 45.
One terminal is connected to the drain of the field effect transistor.
Read out made of Ti / AlSiCu / Ti
As described above, the other terminal is connected to the bit line 46.
Structure of TbFeCo / Al ₂O₃/ GdFeCo magnetic resistance
The anti-effect element 44 was formed.

The write wiring 47 is the magnetoresistive effect element 44.
Proximity to and slightly below.

By arranging the memory cells having the structure manufactured as described above in a matrix, a ferromagnetic memory as shown in FIGS. 2 and 3 can be constructed.

Here, as an example, a ferromagnetic memory having a memory cell in which a magnetoresistive effect element and a field effect transistor are connected is shown, but in the present invention, the magnetoresistive effect element and a diode are connected. The same is also effective in a ferromagnetic memory having a structure having a memory cell. (Embodiment 2) FIG. 7 is a sectional view showing the structure of a magnetoresistive effect element according to another embodiment of the present invention.

The magnetoresistive effect element of FIG. 7 has the pin magnetic layer 7
3 is a GdFeCo layer 731 and TbFeC with small magnetization.
It is composed of a stack of o layers 732. Specifically, Tb
The FeCo layer 732 supplements the composition of Tb so that the magnetization becomes zero.
Around 22%, where transition metal magnetization is superior to compensated composition
And the magnetization per unit volume is 20 to 50 emu / cm ³
Got On this approximately 10 nm TbFeCo layer 732,
The composition of Gd is 23% in the vicinity of the compensating composition. GdFeCo
The layer 731 was stacked to have a thickness of 10 nm. Furthermore, as in the first embodiment
Al to be the tunnel insulating layer 72₂O₃: 1.5nm, memo
GdFeCo having a Gd composition of about 22% to form the remagnetic layer 71:
10 nm was sequentially laminated.

The TbFeCo layer 732 forming the pinned magnetic layer 73 has a larger magnetic field than that of the first embodiment and therefore has a larger leakage magnetic field. However, the distance from the memory magnetic layer 71 is equal to the thickness of the GdFeCo layer 731 having a smaller magnetization. Since they were separated from each other, the leakage magnetic field from the pin magnetic layer 73 in the memory magnetic layer 71 was 5 Oe or less.

When the magnetoresistive effect element is used as a memory, in order to align the magnetization direction of the pinned magnetic layer in one direction, a magnetic field larger than the coercive force of the pinned magnetic layer is applied for initialization. When the pinned magnetic layer is made of ferrimagnetic material and its composition is set so that the magnetization of the rare earth and the magnetization of the transition metal are almost equal, that is, near the compensation composition where the net magnetization is almost zero, the pinned magnetic layer is exposed to an external magnetic field. Although it is difficult to align the magnetization directions, according to this configuration, the pinned layer 73
By making the TbFeCo layer 732 that composes a magnetic layer suitable for initialization, the initialization can be facilitated and stable magnetoresistive characteristics can be realized.

[0076]

Therefore, according to the present invention, GdFe
Alternatively, by using GdFeCo for the memory magnetic layer, the coercive force and magnetization of the memory magnetic layer are set to optimum values, and by using TbFe or TbFeCo for the pin magnetic layer, the coercive force and magnetization of the pin magnetic layer are optimized. By setting to 3, it is possible to easily configure a magnetoresistive effect element in which the memory magnetic layer has good magnetization reversal characteristics and which is excellent in maintaining the magnetization direction.

Further, the composition of the ferrimagnetic material constituting the memory magnetic layer is separated from the compensating composition, and the thickness is 2 to 100.
nm, and further, in order to control the magnitude of the magnetization of the pinned layer, the thickness is set to 2 to 100 nm, thereby reducing the leakage magnetic field to the memory layer and realizing a stable magnetoresistive effect element. it can.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the structure of a magnetoresistive effect element according to this embodiment.

FIG. 2 is a circuit configuration diagram for explaining an information recording operation in a magnetic thin film using the magnetoresistive effect element 10 of the present embodiment.

FIG. 3 is a circuit configuration diagram for explaining an information reading operation in a ferromagnetic memory using the magnetoresistive effect element 10 of the present embodiment.

FIG. 4 is a cross-sectional view showing the structure of a memory cell manufactured as a specific example of the present invention.

FIG. 5 is a diagram for explaining a magnetoresistive effect element having an easy axis of magnetization in the vertical direction.

FIG. 6 is a diagram for explaining a perpendicular magnetization magnetoresistive effect element formed of a ferrimagnetic material.

FIG. 7 is a cross-sectional view showing the structure of a magnetoresistive effect element of Example 2.

[Explanation of symbols]

10 magnetoresistive effect element 11 memory magnetic layer 12 insulating layer 13 pin magnetic layer 21 write drive circuit 31 read drive circuit 41 p-type silicon substrate 43 embedded element isolation region 420 n-type diffusion region 421 n-type diffusion region 422 SiO ₂ gate insulation Film 423 Polysilicon gate electrode 44 Magnetoresistive element 45 TiN local wiring 46 Bit line 47 Write line 71 Memory magnetic layer 72 Tunnel insulating layer 73 Pin magnetic layer 731 GdFeCo layer 732 TbFeCo layer r11, r12, r13, r21, r22, r23 , R
31, r32, r33 magnetoresistive effect elements t11, t12, t13, t21, t22, t23, t
31, t32, t33, Tw11, Tw12, Tw1
3, Tw14, Tw21, Tw22, Tw23, Tw2
4, Tw31, Tw32, Tw33, Tw34, Ts
1, Ts2, Ts3, Tb11, Tb12, Tb21,
Tb22, Tb31, Tb32 Field effect transistors SA1, SA2, SA3 Sense amplifiers BL1, BL2, BL3 Bit lines WL1, WL2, WL3 Word lines WWL1, WWL2, WWL3 Write lines

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G11C 11/15 H01F 10/32 H01F 10/32 H01L 43/10 H01L 27/105 27/10 447 43/10 G01R 33/06 RF terms (reference) 2G017 AD55 AD65 BA00 5E049 AA01 AA04 AA09 AC05 BA16 CB02 DB11 5F083 FZ10 GA09 GA30 JA32 JA36 JA39 JA60 LA03 LA12 LA16 PR22

Claims (8)

[Claims] 1. A memory magnetic layer made of a GdFe or GdFeCo alloy, which stores information depending on the magnetization direction, and a TbFe or TbFeCo alloy, having a coercive force larger than that of the memory magnetic layer and changing the magnetization direction of the memory magnetic layer. A magnetoresistive effect element having a pinned magnetic layer whose magnetization direction does not change even if it is made to exist, and a non-magnetic insulating layer sandwiched between the memory magnetic layer and the pinned magnetic layer. 2. The memory magnetic layer has a thickness of 2 to 100 n.
The magnetoresistive effect element according to claim 1, wherein the magnetoresistive effect element is m. 3. The thickness of the pin magnetic layer is 2 to 100 nm.
The magnetoresistive effect element according to claim 1 or 2, wherein 4. A memory magnetic layer made of a GdFe or GdFeCo alloy, which stores information by a magnetization direction, a TbFe or TbFeCo alloy, and a GdFe or Gd.
A pinned magnetic layer having a coercive force larger than that of the memory magnetic layer, the magnetization direction of which does not change even when the magnetization direction of the memory magnetic layer is changed; and the memory magnetic layer and the pin. A magnetoresistive effect element having a magnetic layer and a non-magnetic insulating layer sandwiched therebetween. 5. The GdFe or GdFeCo alloy constituting the pinned magnetic layer and the TbFe or TbFeCo alloy are magnetically coupled via a non-magnetic layer provided therebetween. Magnetoresistive effect element. 6. The magnetoresistive effect element according to claim 1, wherein at least one of the memory magnetic layer and the pin magnetic layer is an amorphous film. 7. A plurality of magnetoresistive effect elements according to any one of claims 1 to 6, each magnetoresistive effect element, and an electric field effect connected to each magnetoresistive effect element. A ferromagnetic memory in which a 1-bit memory cell is composed of a transistor or a diode. 8. An information device equipped with the ferromagnetic memory according to claim 6 as a built-in memory.