阅读说明：本技术 磁性存储器 (Magnetic memory ) 是由 上田善宽 麦可·阿尔诺·坎萨 于 2020-06-05 设计创作，主要内容包括：根据一个实施方式,本实施方式的磁性存储器具备：第1配线；第2配线；第1开关元件,设置在所述第1配线与所述第2配线之间；第1磁性部件,设置在所述第1开关元件与所述第2配线之间且沿着第1方向延伸；第3配线,设置在所述第1磁性部件与所述第2配线之间；第1磁阻元件,设置在所述第3配线与所述第2配线之间；以及第2开关元件,设置在所述第1磁阻元件与所述第2配线之间。(According to one embodiment, a magnetic memory of the present embodiment includes: 1 st wiring; a 2 nd wiring; a 1 st switching element provided between the 1 st wiring and the 2 nd wiring; a 1 st magnetic member provided between the 1 st switching element and the 2 nd wiring and extending in a 1 st direction; a 3 rd wiring provided between the 1 st magnetic member and the 2 nd wiring; a 1 st magnetoresistive element provided between the 3 rd wiring and the 2 nd wiring; and a 2 nd switching element provided between the 1 st magnetoresistive element and the 2 nd wiring.)

1. A magnetic memory includes:

1 st wiring;

a 2 nd wiring;

a 1 st switching element provided between the 1 st wiring and the 2 nd wiring;

a 1 st magnetic member provided between the 1 st switching element and the 2 nd wiring and extending in a 1 st direction;

a 3 rd wiring provided between the 1 st magnetic member and the 2 nd wiring;

a 1 st magnetoresistive element provided between the 3 rd wiring and the 2 nd wiring; and

and a 2 nd switching element provided between the 1 st magnetoresistive element and the 2 nd wiring.

2. The magnetic memory according to claim 1, wherein the 1 st switching element has a 1 st terminal and a 2 nd terminal, the 1 st terminal being electrically connected to the 1 st wiring,

the 1 st magnetic member has a 1 st end and a 2 nd end, the 1 st end is electrically connected to the 2 nd terminal, the 2 nd end is electrically connected to the 3 rd wiring,

the 1 st magnetoresistive element has a 3 rd terminal and a 4 th terminal, the 3 rd terminal is electrically connected to the 3 rd wiring,

the 2 nd switching element has a 5 th terminal and a 6 th terminal, the 5 th terminal is electrically connected to the 4 th terminal, and the 6 th terminal is electrically connected to the 2 nd wiring.

3. The magnetic memory according to claim 2, wherein the 2 nd end portion is electrically connected to one of the 2 opposite surfaces of the 3 rd wiring, and the 3 rd terminal is electrically connected to the other surface of the 3 rd wiring.

4. The magnetic memory according to claim 1, wherein the 1 st magnetic member has a 1 st end portion and a 2 nd end portion, the 1 st end portion being electrically connected to the 1 st wiring via the 1 st switching element, the 2 nd end portion being electrically connected to one of the 2 opposite surfaces of the 3 rd wiring,

one terminal of the 1 st magnetoresistive element is electrically connected to the other surface of the 3 rd wiring, and the other terminal is electrically connected to the 2 nd wiring via the 2 nd switching element.

5. The magnetic memory according to claim 1, wherein the 1 st wire and the 2 nd wire extend along a 2 nd direction intersecting the 1 st direction, and the 3 rd wire extends along a 3 rd direction intersecting the 1 st direction and the 2 nd direction.

6. The magnetic memory according to claim 1, wherein the 1 st magnetic member has a cylindrical shape.

7. The magnetic memory according to claim 6, wherein the 1 st magnetic member is any one of a circle, an ellipse, or a polygon in an outer peripheral shape of a cross section in a plane orthogonal to the 1 st direction.

8. The magnetic memory of claim 6, further provided with:

a 2 nd magnetic member having a 3 rd end portion and a 4 th end portion, the 3 rd end portion being electrically connected to the 1 st wiring via the 1 st switching element, the 4 th end portion being electrically connected to an inner surface of the 1 st magnetic member; and

and a 4 th wiring provided apart from the 2 nd magnetic member in a direction intersecting the 1 st direction.

9. The magnetic memory according to claim 2, wherein the 1 st magnetoresistive element includes a 1 st magnetic layer electrically connected to the 3 rd wiring, a 2 nd magnetic layer electrically connected to the 5 th terminal, and a nonmagnetic layer provided between the 1 st magnetic layer and the 2 nd magnetic layer.

10. The magnetic memory according to claim 1, further comprising a control circuit that supplies a current for displacing the magnetic wall of the 1 st magnetic member between the 1 st wire and the 3 rd wire, and supplies a read current between the 2 nd wire and the 3 rd wire.

11. A magnetic memory includes:

1 st wiring;

a 2 nd wiring;

a 1 st switching element provided between the 1 st wiring and the 2 nd wiring;

a 1 st magnetic member provided between the 1 st switching element and the 2 nd wiring;

a 3 rd wiring provided between the 1 st magnetic member and the 2 nd wiring;

a 1 st magnetoresistive element provided between the 3 rd wiring and the 2 nd wiring;

a 2 nd switching element provided between the 1 st magnetoresistive element and the 2 nd wiring; and

and a control circuit electrically connected to the 1 st wire, the 2 nd wire, and the 3 rd wire, wherein the control circuit applies a 1 st voltage to the 1 st wire, applies a 2 nd voltage different from the 1 st voltage to the 3 rd wire, applies a 3 rd voltage between the 1 st voltage and the 2 nd voltage to the 2 nd wire, displaces a magnetic wall of the 1 st magnetic member, applies a 4 th voltage to the 2 nd wire, applies a 5 th voltage different from the 4 th voltage to the 3 rd wire, applies a 6 th voltage between the 4 th voltage and the 5 th voltage to the 1 st wire, and reads information from the 1 st magnetoresistive element.

12. The magnetic memory of claim 11, further provided with:

a 4 th wiring adjacent to the 1 st wiring in a 1 st direction;

a 5 th wiring adjacent to the 2 nd wiring in the 1 st direction;

a 3 rd switching element provided between the 4 th wiring and the 5 th wiring;

a 2 nd magnetic member provided between the 3 rd switching element and the 5 th wiring;

a 2 nd magnetoresistive element provided between the 2 nd magnetic member and the 5 th wiring; and

a 4 th switching element provided between the 2 nd magnetoresistive element and the 5 th wiring;

the 3 rd wiring is provided between the 2 nd magnetic member and the 2 nd magnetoresistive element,

the control circuit applies the 3 rd voltage to the 4 th wiring and the 5 th wiring when the magnetic wall of the 1 st magnetic member is displaced, and applies the 6 th voltage to the 4 th wiring and the 5 th wiring when the information is read from the 1 st magnetoresistive element.

13. The magnetic memory according to claim 12, wherein the 1 st switching element has a 1 st terminal and a 2 nd terminal, the 1 st terminal being electrically connected to the 1 st wiring,

the 1 st magnetic member has a 1 st end and a 2 nd end, the 1 st end is electrically connected to the 2 nd terminal, the 2 nd end is electrically connected to the 3 rd wiring,

the 1 st magnetoresistive element has a 3 rd terminal and a 4 th terminal, the 3 rd terminal is electrically connected to the 3 rd wiring,

the 2 nd switching element has a 5 th terminal and a 6 th terminal, the 5 th terminal is electrically connected to the 4 th terminal, the 6 th terminal is electrically connected to the 2 nd wiring,

the 3 rd switching element has a 7 th terminal and an 8 th terminal, the 7 th terminal is electrically connected to the 4 th wiring,

the 2 nd magnetic member has a 3 rd end and a 4 th end, the 3 rd end is electrically connected to the 8 th terminal, the 4 th end is electrically connected to the 3 rd wiring,

the 2 nd magnetoresistive element has a 9 th terminal and a 10 th terminal, the 9 th terminal is electrically connected to the 3 rd wiring,

the 4 th switching element has an 11 th terminal and a 12 th terminal, the 11 th terminal is electrically connected to the 10 th terminal, and the 12 th terminal is electrically connected to the 5 th wiring.

14. The magnetic memory of claim 13 wherein the 1 st and 2 nd magnetic components extend along a 2 nd direction that intersects the 1 st direction.

15. The magnetic memory according to claim 14, wherein the 1 st magnetic member and the 2 nd magnetic member have a cylindrical shape.

16. The magnetic memory according to claim 14, wherein the 1 st wire, the 2 nd wire, the 4 th wire, and the 5 th wire extend along a 3 rd direction intersecting the 1 st direction and the 2 nd direction, the 3 rd wire extends along a direction intersecting the 2 nd direction and the 3 rd direction.

17. The magnetic memory according to claim 15, wherein the 1 st magnetic member and the 2 nd magnetic member are any one of a circle, an ellipse, or a polygon in an outer peripheral shape of a cross section in a plane orthogonal to the 2 nd direction.

18. The magnetic memory of claim 15, further provided with:

a 3 rd magnetic member having a 5 th end and a 6 th end, the 5 th end being electrically connected to the 2 nd terminal, the 6 th end being electrically connected to an inner surface of the 1 st end;

a 6 th wiring provided apart from the 3 rd magnetic member in a direction intersecting the 2 nd direction;

a 4 th magnetic member having a 7 th end portion and an 8 th end portion, the 7 th end portion being electrically connected to the 8 th terminal, the 8 th end portion being electrically connected to an inner surface of the 3 rd end portion; and

and a 7 th wiring provided apart from the 4 th magnetic member in a direction intersecting the 2 nd direction.

Technical Field

Embodiments of the present invention relate to a magnetic memory.

Background

A magnetic memory is known in which a magnetic wall of a magnetic member is moved (displaced) by applying a current to the magnetic member. The Magnetic memory includes a configuration in which a 1 st wire is electrically connected to one end of a Magnetic member, and a 2 nd wire is connected to the other end of the Magnetic member via a magnetoresistive element (e.g., a Magnetic Tunnel Junction (MTJ) element) and a switching element, and a displacement current for displacing a Magnetic wall of the Magnetic member flows between the 1 st wire and the 2 nd wire to move the Magnetic wall.

Disclosure of Invention

The magnetic memory of the present embodiment includes: 1 st wiring; a 2 nd wiring; a 1 st switching element provided between the 1 st wiring and the 2 nd wiring; a 1 st magnetic member provided between the 1 st switching element and the 2 nd wiring and extending in a 1 st direction; a 3 rd wiring provided between the 1 st magnetic member and the 2 nd wiring; a 1 st magnetoresistive element provided between the 3 rd wiring and the 2 nd wiring; and a 2 nd switching element provided between the 1 st magnetoresistive element and the 2 nd wiring.

Drawings

Fig. 1 is a schematic diagram showing a magnetic memory according to embodiment 1.

Fig. 2 is a schematic diagram showing a specific example of the magnetic memory according to embodiment 1.

Fig. 3 is a schematic diagram showing voltage conditions in the shift operation of the magnetic memory according to embodiment 1.

Fig. 4 is a schematic diagram showing voltage conditions in the shift operation of the magnetic memory according to embodiment 1.

Fig. 5 is a schematic diagram showing voltage conditions in the read operation of the magnetic memory according to embodiment 1.

Fig. 6 is a schematic diagram showing voltage conditions in the read operation of the magnetic memory according to embodiment 1.

Fig. 7A is a schematic diagram showing a magnetic memory of a comparative example.

Fig. 7B is a diagram showing an example of current distribution in the magnetic memory of the comparative example.

Fig. 8A is a schematic diagram showing the magnetic memory according to embodiment 1.

Fig. 8B is a diagram showing a current distribution in the shift operation of the magnetic memory according to embodiment 1.

Fig. 8C is a diagram showing a current distribution in the read operation of the magnetic memory according to embodiment 1.

Fig. 9 to 17 are sectional views showing the manufacturing steps of the manufacturing method of embodiment 2.

Detailed Description

The magnetic memory of the present embodiment includes: 1 st wiring; a 2 nd wiring; a 1 st switching element provided between the 1 st wiring and the 2 nd wiring; a 1 st magnetic member provided between the 1 st switching element and the 2 nd wiring and extending in a 1 st direction; a 3 rd wiring provided between the 1 st magnetic member and the 2 nd wiring; a 1 st magnetoresistive element provided between the 3 rd wiring and the 2 nd wiring; and a 2 nd switching element provided between the 1 st magnetoresistive element and the 2 nd wiring.

(embodiment 1)

Fig. 1 shows a magnetic memory according to embodiment 1. The magnetic memory according to embodiment 1 includes a plurality of (4 in fig. 1) memory cells 10 arranged in an array₁₁、10₁₂、10₂₁、10₂₂Bit line (1 st wiring) BL₁、BL₂And data line (2 nd wiring) DL₁、DL₂And source line (3 rd wiring) SL₁、SL₂And control circuits 101, 102, 103. Memory cell 10_ij(i, j is 1, 2) has 1 st to 3 rd terminals, and a 1 st terminal 11a_ijIs electrically connected to the data line DL_i2 nd terminal 11b_ijIs electrically connected to the bit line BL_iThe 3 rd terminal 11c_ijElectrically connected to the source line SL_j. In addition, data line DL₁、DL₂Source lines SL electrically connected to the control circuit 101₁、SL₂Bit line BL electrically connected to control circuit 102₁、BL₂Is electrically connected to the control circuit 103. In fig. 1, the data lines, the source lines, and the bit lines are controlled by 3 control circuits, but may be controlled by 1 control circuit.

In the present specification, the term "power" refers toThe term "connected to B" means that a and B may be directly connected or indirectly connected via a conductor. In fig. 1, the magnetic memory includes 4 memory cells, but when m and n are natural numbers, memory cells arranged in an m × n array may be provided. In this case, the magnetic memory includes m data lines DL₁～DL_mM bit lines BL₁～BL_mAnd n source lines SL₁～SL_n。

Each memory cell 10_ij(i, j is 1, 2) includes a magnetic member 12_ijMagneto-resistive element 14_ijA switching element 16 having 2 terminals_ijAnd a switching element 18 having 2 terminals_ij。

Magnetic component 12_ij(i, j ═ 1, 2) is composed of a perpendicular magnetic material extending in the z direction (vertical direction in fig. 1). Magnetic component 12_ij(i, j is 1, 2) has one end passing through the 3 rd terminal 11c_ijAnd is electrically connected to the source line SL_jAnd the other end via a switching element 18_ijIs electrically connected to the bit line BL_i. Further, preferably, the magnetic member 12_ijOne end of (i, j is 1, 2) via the 3 rd terminal 11c_ijAnd source line SL_jAre configured in a connected mode. Data line DL₁、DL₂And bit line BL₁、BL₂Extending along the x-direction (left-right direction in fig. 1), respectively, and source lines SL₁、SL₂Extending along a y-direction orthogonal to the z-direction and the x-direction, respectively.

Magnetoresistive element 14_ij(i, j is 1, 2) is to be written to the magnetic member 12_ijFor example, mtj (magnetic Tunnel junction) elements are used as the information (magnetization direction) readout elements. The magnetoresistive element 14 will be described below_ijThe MTJ element will be described as (i, j — 1, 2). MTJ element 14_ij(i, j is 1, 2) a 1 st terminal electrically connected to the source line SL_jThe 2 nd terminal is electrically connected to the switching element 16_ijA terminal of (2).

Switching element 16_ijThe other terminal of (i, j-1, 2) is connected to the 1 st terminal 11a_ijIs electrically connected toData line DL_iSwitching element 18_ijThe other terminal of (i, j-1, 2) is connected to the 2 nd terminal 11b_ijAnd is electrically connected to the bit line BL_i。

Next, referring to FIG. 2, memory cell 10 is described_ijThe detailed structure of (i, j ═ 1, 2) will be described. FIG. 2 is a view along the data line DL₁A cross-sectional view of the magnetic memory cut.

Magnetic component 12_ij(i, j is 1, 2) has, for example, a cylindrical shape extending in the z direction, and includes a 1 st end portion 12a_ijAnd 2 nd end portion 12b_ij. Magnetic component 12_ijThe cross section taken on the x-y plane (i, j ═ 1, 2) has, for example, a circular ring shape, but is not limited to this shape. The outer circumferential shape of the cross section may be a circle, an ellipse, or a polygon.

Magnetic component 12_ij(i, j ═ 1, 2) is composed of, for example, a multilayer film containing cobalt, nickel, or the like. As magnetic component 12_ijAs the material (i, j — 1, 2), an alloy containing an element selected from iron, cobalt, platinum, palladium, magnesium, and a rare earth element may be used in addition to cobalt and nickel.

Magnetic component 12_ij(i, j is 1, 2) includes a plurality of regions 12c arranged along the z direction_ijThese areas 12c_ijIs formed by arranging on a magnetic part 12_ijIs narrowed portion 12d of the outer surface of_ijAnd (5) separating. In addition, these regions 12c_ij(i, j ═ 1, 2) has at least 1 magnetic domain. Each magnetic member 12_ij(i, j is 1, 2) when it is opposite to the 1 st end 12a_ijAnd 2 nd end portion 12b_ijWhen a drive current (shift current) is supplied therebetween, the magnetic member 12_ijMoves in the z direction, and stops at the narrowed portion 12d in a state where no drive current is supplied_ij. Magnetic component 12_ij1 st end 12a of (i, j ═ 1, 2)_ijElectrically connected to the source line SL_ijPreferably, the source line SL_ijAre connected with each other.

MTJ element 14_ij(i, j is 1, 2) includes a free layer 14a whose magnetization direction is changeable_ijFixed layer 14b with fixed magnetization direction_ijAnd is provided in the free layer 14a_ijAnd the fixed layer 14b_ijNon-magnetic insulating layer (tunnel barrier layer) 14c therebetween_ij. The MTJ element 14_ijFree layer 14a of (i, j ═ 1, 2)_ijIs electrically connected to the magnetic member 12_ij1 st end portion 12a of_ijFixed layer 14b_ijIs electrically connected to the switching element 16_ijA terminal of (2). Further, it is preferable that the MTJ element 14_ijFree layer 14a of (i, j ═ 1, 2)_ijTo be connected with the source line SL_jAre configured in a connected mode. That is, it is preferable that the MTJ element 14_ijFree layer 14a of (i, j ═ 1, 2)_ijTo be connected with the source line SL_jAre disposed so as to be in contact with one surface (the lower surface in fig. 2). Switching element 16_ijThe other terminal of (i, j — 1, 2) is electrically connected to the data line DL_i. In addition, a magnetoresistive element in which a nonmagnetic insulating layer of an MTJ element is replaced with a nonmagnetic metal layer may be used instead of the MTJ element.

In addition, the magnetic member 12_ij2 nd end 12b of (i, j ═ 1, 2)_ijThrough to the 2 nd end 12b_ijA non-magnetic conductor 17 disposed so as to contact the inner surface thereof_ijAnd is electrically connected to the magnetic member 19_ijTo one end of (a). That is, the magnetic member 19_ijOne end of (i, j ═ 1, 2) to enter magnetic part 12_ij2 nd end portion 12b_ijIs arranged in an inner side manner. Magnetic part 19_ijIs electrically connected to the switching element 18 at the other end_ijA terminal of (2). Magnetic part 19_ij(i, j ═ 1, 2) is made of, for example, a soft magnetic material.

Switching element 18_ijThe other terminal of (i, j — 1, 2) is electrically connected to the bit line BL_i. In the magnetic part 19₁₁A field line (hereinafter, also referred to as fl (field line))20 is arranged on one side (left side in fig. 2) in the x-axis direction of the display panel₁On the other side (right side), a field line 20 is provided₂. In addition, in the magnetic member 19₁₂Is provided with field lines 20 at one side portion (left side in fig. 2) in the x-axis direction₂On the other side (right side), a field line 20 is provided₃. That is, field lines 20₂Is arranged on the magnetic member 19₁₁And a magnetic member 19₁₂In the meantime. Field wire 20₁、20₂、20₃Respectively extending in the y-direction.

Magnetic part 19₁₁、19₁₂As described in the writing method described below, information (magnetization direction) is written into the corresponding magnetic member 12 by a magnetic field generated when a writing current is applied to the field line_ij1 st end 12a of (i 1, j 1, 2)_ijAnd 2 nd end portion 12b_ijA drive current (shift current) is supplied therebetween, thereby the written information is moved to the magnetic member 12_ij1 st end portion 12a of_ij. At this time, by using the MTJ element 14_ijFree layer 14a of_ijDetecting the end 12a from the 1 st end_ijAnd (i 1, j 1, 2) to read out information.

Switching element 16_ij(i, j ═ 1, 2) and switching element 18_ijThe (i, j ═ 1, 2) may be a 2-terminal switching element, for example. When the voltage applied between the 2 terminals is equal to or less than the threshold value, the switching element 16_ij、18_ij(i, j ═ 1, 2) is in a "high resistance" state, e.g., electrically non-conducting. The switching element 16 in the case where the voltage applied between the 2 terminals exceeds the threshold value_ij，18_ij(i, j ═ 1, 2) is in a "low resistance" state, and is brought into an electrically conductive state, for example. Switching element 16_ij，18_ij(i, j ═ 1, 2) in the on state, the on state is maintained while a current of a value equal to or greater than the holding current continues to flow. Switching element 16_ij，18_ij(i, j ═ 1, 2) this function is exhibited regardless of the polarity of the voltage. The switching element 16_ij，18_ij(i, j ═ 1, 2) contains at least 1 or more chalcogen elements selected from the group consisting of Te, Se, and S. Alternatively, a chalcogenide compound which is a compound containing the chalcogen element may be contained. The switching element may contain at least 1 or more element selected from the group consisting of B, Al, Ga, In, C, Si, Ge, Sn, As, P, and Sb.

(action)

Next, the operation of the magnetic memory according to embodiment 1 will be described with reference to fig. 2 to 6.

(write action)

First, a write operation will be described. Pair memory cell 10₁₁The case of performing data writing will be described as an example. At the field line 20₁And 20₂The magnetic member 19 is controlled by passing mutually opposite currents and generating a magnetic field by the currents₁₁The magnetization of (2). Further, the magnetic member 19 is used₁₁Is magnetized via the conductor 17₁₁To control the nearest magnetic component 12₁₁End portion 12b of₁₁Area 12c of₁₁The information (magnetization direction) is written by the magnetization of (1). Further, at the field line 20₁～20₃The control of the flowing current may be performed by any one of the control circuits 101, 102, and 103 shown in fig. 1, or may be performed by another control circuit not shown.

Then, the switching element 18 is turned on using the control circuits 102 and 103₁₁In the on state, at bit line BL₁And source line SL₁A shift current is passed between the two regions to write into the region 12c₁₁To magnetic element 12 in turn₁₁End portion 12a of₁₁And (4) side movement.

In addition, during the shift operation, the source line SL will be aligned₁The voltage condition when the ground voltage Vss is applied is shown in FIG. 3, where the ground voltage Vss is applied to the source line SL₁The voltage conditions in the case of application of the negative voltage Vnn are shown in fig. 4. Fig. 3 and 4 show a case where the magnetic wall moves in the direction in which the current flows. In the case shown in FIG. 3, the bit line BL is controlled by the control circuit 103₁A shift voltage Vshift is applied to the source line SL by the control circuit 102₁Ground voltage Vss is applied. At this time, for the unconnected memory cell 10₁₁Of (2), e.g. bit line BL₂And source line SL₂Data line DL₁、DL₂An intermediate voltage Vmid between the shift voltage Vshift and the ground voltage Vss is applied. In the case shown in fig. 4, the control circuit 103 controls the bit line BL₁A shift voltage Vshift is applied to the source line SL by the control circuit 102₁Applying a negative voltage Vnn to an unconnected memory cell 10₁₁Is prepared fromLines, e.g. bit lines BL₂And source line SL₂Data line DL₁、DL₂Ground voltage Vss is applied by control circuits 101, 102, and 103. In either case, the shift current is from the bit line BL₁Via the switching element 18₁₁Magnetic member 19₁₁And an electric conductor 17₁₁Magnetic member 12₁₁Flows through the source line SL₁Not in the magnetic part 12₁₂Magnetic member 12₂₁Magnetic member 12₂₂Switching element 18₁₂、18₂₁、18₂₂And (4) circulating. In addition, the MTJ element 14 is not provided with₁₁、14₁₂、14₂₁、14₂₂Switching element 16₁₁、16₁₂、16₂₁、16₂₂And (4) circulating.

(read operation)

Next, the slave memory cell 10 is fetched₁₁The read operation will be described by taking the case of reading data as an example. First, the switching element 16 is controlled by the control circuit 101 and the control circuit 102₁₁Is in the on state. The control circuit 101 is used to control the source line SL₁The voltage condition when the ground voltage Vss is applied is shown in fig. 5, and the voltage condition is applied to the source line SL₁The voltage conditions in the case of application of the negative voltage Vnn are shown in fig. 6. In the case shown in fig. 5, the control circuit 101 is used to control the data lines DL₁A read voltage Vread is applied to the source line SL by the control circuit 102₁Ground voltage Vss is applied. At this time, the MTJ element 14 is not connected₁₁Of (2), e.g. bit line BL₁、BL₂And source line SL₂Data line DL₂An intermediate voltage Vmid between the read voltage Vread and the ground voltage Vss is applied by the control circuits 101, 102, and 103. In the case shown in fig. 6, the control circuit 101 controls the data lines DL₁A read voltage Vread is applied to the source line SL by the control circuit 102₁Applying a negative voltage Vnn to an unconnected memory cell 10₁₁Of (2), e.g. bit line BL₁、BL₂And source line SL₂Data line DL₂Ground voltage Vss is applied by control circuits 101, 102, and 103. In either case, readAll current flows from the data line DL₁Via the switching element 16₁₁MTJ element 14₁₁Flows through the source line SL₁Not in the MTJ element 14₁₂、14₂₁、14₂₂Switching element 16₁₂、16₂₁、16₂₂And (4) circulating. In addition, it is not different from the magnetic member 12₁₁、12₁₂、12₂₁、12₂₂Switching element 18₁₁、18₁₂、18₂₁、18₂₂And (4) circulating. Further, the MTJ element 14₁₁Responsive to a free layer from the nearest MTJ element 14₁₁Magnetic component 12₁₁Area 12c of₁₁Has a magnetization direction corresponding to the leakage magnetic field. Thus, the information read corresponds to the information stored in the nearest MTJ element 14₁₁Magnetic component 12₁₁Area 12c of₁₁The information of (1).

In the present embodiment, the case where the magnetic wall moves in the direction in which the current flows has been described, but the case where the magnetic wall moves in the direction opposite to the direction in which the current flows may be used. The moving direction of the magnetic wall can be controlled by the material of the magnetic member, the material or position of the conductive member laminated on the magnetic member, and the manufacturing conditions. When a conductive member is laminated on a magnetic member, for example, Pt, W, Ta, or the like can be used as a material of the conductive member, but the present invention is not limited to these. The movement of the magnetic wall can be controlled by utilizing the SOT (Spin Orbit Torque) effect based on the material of the conductive member.

As described above, in the magnetic memory according to the present embodiment, since the path of the shift current for moving the magnetic wall is separated from the read current path, erroneous shift due to the read current, that is, read disturb can be avoided. This can expand the operating range due to the current non-uniform distribution. The expansion of the operation range will be described with reference to the following comparative examples.

Comparative example

Next, fig. 7A shows a schematic diagram showing the structure of the magnetic memory of the comparative example, and fig. 7B shows a current distribution of the magnetic memory of the comparative example. As shown in fig. 7A, the magnetic memory of this comparative example includes a memory cell 10 in which a magnetic member 12, an MTJ element 14, and a switching element 16 are provided between 2 terminals 11a and 11 b. The MTJ element 14 has the following configuration: is disposed between the magnetic member 12 and the switching element 16, and the terminal 11a is electrically connected to the switching element 16, and the terminal 11b is electrically connected to the magnetic member 12.

In the magnetic memory of this comparative example, the read operation and the shift operation of the magnetic wall are performed by passing the read current Iread and the shift current Ishift between the terminal 11a and the terminal 11 b.

The magnetic memory thus constructed has a current distribution as shown in fig. 7B. The holding current Ihold of the switching element 16, that is, the current at which the switching element 16 maintains the ON state is set to be smaller than the read current Iread of the magnetic memory, the threshold current Ic for displacing the magnetic wall of the magnetic member 12 is larger than the read current Iread, and the displacement current Ishift for displacing the magnetic wall is larger than the threshold current Ic and smaller than the current Ibd for tunnel barrier destruction of the MTJ element 14. That is, in the magnetic memory of the comparative example, it is necessary to arrange the current distributions of the sense current Iread and the shift current Ishift between the holding current Ihold of the switching element 16 and the destruction current Ibd of the MTJ element.

In contrast, the magnetic memory according to the present embodiment has a configuration including 3 terminals as shown in fig. 8A. That is, the memory cell 10 is provided with the switching element 16, the MTJ element 14, the magnetic member 12, and the switching element 18 between the terminals 11a and 11b, and further with the terminal 11c between the MTJ element 14 and the magnetic member 12. In the magnetic memory shown in fig. 8A, the read operation is performed by passing a read current Iread between the terminal 11a and the terminal 11c, and the shift operation is performed by passing a shift current Ishift between the terminal 11b and the terminal 11 c.

In the magnetic memory shown in fig. 8A, since the path of the shift current is separated from the path of the sense current, the shift current Ishift has only to have the current distribution shown in fig. 8B, and the sense current Iread has only to have the current distribution shown in fig. 8C. That is, the shift current Ishift may be larger than the holding current Ihold of the switching element 18 and the shift threshold current Ic, and the sense current Iread may be larger than the holding current Ihold of the switching element 16 and smaller than the destruction current Ibd of the MTJ element 14. Therefore, the magnetic memory according to the present embodiment can have a wider operating range than the magnetic memory according to the comparative example.

As described above, according to the present embodiment, since the path of the shift current is separated from the path of the read current, the operation range can be expanded. In addition, the occurrence of a read disturb (read disturb) due to the read current can be suppressed. Since the shift current does not flow through the MTJ element, the influence of the resistance change (MR) of the MTJ element on the pulse shape of the shift current can be eliminated. Further, since the shift current does not flow through the MTJ element, the voltage stress of the MTJ element is eliminated, and the durability can be improved. Since the MTJ element and the magnetic member are not directly connected, the effective MR of the MTJ element can be increased. Since the operating range can be expanded, the sense current can be increased, and the on state of the switching element can be easily maintained.

(embodiment 2)

Next, embodiment 2 will be explained. Embodiment 2 is a method for manufacturing the magnetic memory according to embodiment 1, and the manufacturing steps thereof are shown in fig. 9 to 17.

First, a metal layer 300 made of, for example, alumina is formed on a silicon substrate 200, or a substrate 300 made of aluminum is attached to the silicon substrate 200 (fig. 9). Then, an anodic oxidation treatment is applied to the metal layer 300. The anodization is performed by using the metal layer 300 or the silicon substrate 200 as an anode and applying electricity to an electrolyte solution (for example, any one of sulfuric acid, oxalic acid, and phosphoric acid, or a mixture thereof). At this time, the metal layer (aluminum) is oxidized to become metal ions and dissolved. The metal ions are bonded to oxygen in the liquid to form metal oxide (alumina), and remain on the surface of the metal layer 300 to grow. At this time, dissolution and growth are performed simultaneously, and fine pores 302 surrounded by alumina are formed in the aluminum surface of the metal layer 300. In the fabrication of the hole 302, a 2 nd voltage different from the 1 st voltage applied in the fabrication of the hole is periodically applied. While the 2 nd voltage is applied, a portion 302a having a small dimension (diameter) in the x direction and the y direction shown in fig. 2 is formed. Further, the vicinity of the region where the hole 302 is formed is changed from aluminum to aluminum oxide 300A (fig. 10).

Then, as shown in fig. 11, a magnetic layer 304 is formed so as to cover the inner surface of the hole 302. The magnetic layer 304 becomes the magnetic component 12 shown in FIG. 2₁₁、12₁₂. Next, as shown in fig. 12, a nonmagnetic insulating film (e.g., a silicon oxide film) 306 is formed so as to leave the upper portion of the hole 302 and fill the hole 302.

Next, as shown in fig. 13, a nonmagnetic conductor layer 308 is formed so as to cover the side surface of the hole 302. The conductor layer 308 becomes the conductor layer 17 shown in FIG. 2₁₁、17₁₂. Then, a nonmagnetic insulating film (e.g., a silicon oxide film) 310 is formed so as to be buried in the hole 302 and cover the upper surface of the aluminum oxide 300A. An opening exposing the upper surface of the insulating film 306 and the inner surface of the conductor layer 308 is formed in the insulating film 310 by photolithography, and a magnetic member (for example, a soft magnetic member) 319 is embedded in the opening. The magnetic member 319 becomes the magnetic member 19 shown in fig. 2₁₁、19₁₂A part of (a). Then, on the insulating film 310, wiring 320 is formed₁、320₂、302₃. These wirings 320₁、320₂、302₃Respectively become field lines 20 as shown in fig. 2₁、20₂、20₃(FIG. 14).

Next, to cover the wiring 320₁、320₂、302₃A nonmagnetic insulating film (e.g., a silicon oxide film) 322 is formed (fig. 15). An opening exposing the upper surface of the magnetic member 319 is formed in the insulating film 322 by photolithography, and the opening is filled with a magnetic member (for example, a soft magnetic member) 324. Magnetic member 324 becomes magnetic member 19 shown in fig. 2₁₁、19₁₂The remaining portion of (a). Then, a nonmagnetic insulating film (e.g., a silicon oxide film) 332 is formed on the insulating film 322 so as to cover the magnetic member 324. An opening exposing the upper surface of the magnetic member 324 is formed in the insulating film 332 using a photolithography technique. Forming a switch by embedding in the openingComponent 330₁、330₂. These switching elements 330₁、330₂Becomes the switching element 18 shown in FIG. 2₁₁、18₁₂. Then, an electrically connected switching element 330 is formed on the insulating film 332₁、330₂Wiring 340 (fig. 15). The wiring 340 becomes a bit line BL shown in fig. 2₁. Then, a non-magnetic insulating film (e.g., a silicon oxide film), not shown, is formed so as to cover the wiring 340, and the insulating film is planarized by CMP (Chemical Mechanical Polishing) to expose the surface of the wiring 340.

Next, a CMOS (complementary metal oxide semiconductor) circuit including the control circuits 101, 102, 103, and the like shown in fig. 1 is formed on another substrate 400, and the substrate 400 on which the CMOS circuit is formed is turned over and bonded to the substrate on which the magnetic layer 304, the magnetic member 324, and the switching element 330 are formed as shown in fig. 16₁、330₂And wiring 340. That is, the surface of the substrate 400 on which the CMOS circuit and the like are formed is bonded to the surface on which the wiring 340 is formed. Further, the wirings 340 and 320 shown in fig. 16₁、320₂、320₃Is electrically connected to the CMOS circuit.

Next, the silicon substrate 200 is polished from the back side using, for example, CMP, so that the surface of the alumina 300A is exposed. At this time, the end of the magnetic layer 304 is also exposed. Then, a wiring 500 electrically connected to the magnetic layer 304 is formed on the surface exposed by the alumina₁、500₂. These wirings 500₁、500₂The source lines SL shown in FIG. 2₁、SL₂. Then, to cover the wiring 500₁、500₂In this embodiment, a nonmagnetic insulating film (e.g., a silicon oxide film) 502 is formed. For example, the insulating film 502 is planarized by CMP to form the wiring 500₁、500₂Is exposed. Forming wirings 500 electrically connected to the exposed surfaces₁、500₂MTJ element 516 of₁、516₂. MTJ element 516_i(i is 1, 2) includes a fixed layer 514 having a fixed magnetization direction, and is formed on the fixed layer 514 and the wiring 500_iAnd is magnetizedA free layer 510 with a variable direction, and a non-magnetic insulating layer (tunnel barrier layer) 512 formed between the fixed layer 514 and the free layer 510.

Next, as shown in FIG. 17, to cover the MTJ element 516₁、516₂A nonmagnetic insulating film (e.g., a silicon oxide film) 520 is formed. Then, the MTJ element 516 is formed on the insulating film 520 by photolithography₁、516₂Openings exposed in the upper surface of the fixed layer 514, and switching elements 524 electrically connected to the fixed layer 514 are formed in the openings₁、524₂. These switching elements 524₁、524₂Becomes the switching element 16 shown in FIG. 2₁₁、16₁₂. Then, an electrical connection to these switching elements 524 is formed₁、524₂Wiring 530. The wiring 530 becomes the data line DL shown in fig. 2₁. Then, a non-magnetic insulating film (e.g., a silicon oxide film), not shown, is formed so as to cover the wiring 530, and the insulating film is planarized by CMP. Furthermore, MTJ element 516₁、516₂And wiring 530 and wiring 500₁Wiring 500₂And the like are electrically connected to the CMOS circuit formed on the substrate 400 via a through hole buried in a fine hole (for example, the hole 302 shown in fig. 10) formed in the alumina 300A. The hole in which the through hole is embedded is a hole in which the magnetic layer 304 is not formed in the step shown in fig. 11. Further, a magnetic layer may be formed in the hole. The magnetic layer becomes a dummy magnetic layer.

As described above, the magnetic memory of embodiment 1 is manufactured.

In the memory cell of the magnetic memory manufactured by the embodiment 2, as described in the embodiment 1, since the path of the shift current for moving the magnetic wall is separated from the read current path, the erroneous shift by the read current, that is, the read disturb can be avoided. This can expand the operating range due to the current non-uniform distribution.

Several embodiments of the present invention have been described, but these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in other various manners, and various omissions, substitutions, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalent scope thereof.