JP2003318366A - Magnetic random access memory - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow a write magnetic field to efficiently work on a TMR element of an MRAM. <P>SOLUTION: Immediately under the TMR element 23, a write word line 20B is disposed. The write word line 20B is extended in an X direction, and side faces and the bottom face of the write word line 20B are covered with a yoke material 25B having high magnetic permeability. The yoke material 25B sinks below the top face of the write word line 20B. Immediately above the TMR element 23, a data selection line (read/write bit line) 24 is disposed. The data selection line 24 is extended in a Y direction which crosses the X direction. The top face of the data selection line 24 is covered with a yoke material 27 having high magnetic permeability. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides "1" by the tunneling magnetoresistive effect.
“0” -Magnetic random access memory (MRAM: Magn) that has a memory cell using a TMR element that stores information.
etic Random Access Memory).

[0002]

2. Description of the Related Art In recent years, many memories for storing information have been proposed based on a new principle. One of them is
Tunneling Magneto Resistive (hereinafter referred to as TMR) proposed by Roy Scheuerlein et.al. There is a memory utilizing the effect (for example, IS
SCC2000 Technical Digest p.128 `` A 10ns Read and Wr
ite Non-Volatile Memory Array Using a Magnetic Tun
nel Junction and FET Switch in each Cell ”).

The magnetic random access memory stores "1", "0" -information by the TMR element. As shown in FIG. 96, the TMR element has a structure in which an insulating layer (tunnel barrier) is sandwiched by two magnetic layers (ferromagnetic layers).
The information stored in the TMR element is determined by whether the spin directions of the two magnetic layers are parallel or antiparallel.

Here, as shown in FIG. 97, parallel means
The spin directions (magnetization directions) of the two magnetic layers are the same, and antiparallel means that the spin directions of the two magnetic layers are opposite (the direction of the arrow indicates the spin). Indicates the direction of.).

Usually, on one side of the two magnetic layers,
An antiferromagnetic layer is arranged. The antiferromagnetic layer is a member for easily rewriting information by fixing the spin direction of the magnetic layer on one side and changing only the spin direction of the other side.

The magnetic layer whose spin direction is fixed is called a fixed layer or pinned layer. A magnetic layer whose spin direction can be freely changed according to write data is called a free layer or a storage layer.

As shown in FIG. 97, when the spin directions of the two magnetic layers are parallel, the tunnel resistance of the insulating layer (tunnel barrier) sandwiched between these two magnetic layers is the lowest. This state is the "1" -state. Also, 2
When the spin directions of the two magnetic layers are antiparallel, the tunnel resistance of the insulating layer (tunnel barrier) sandwiched between these two magnetic layers is the highest. This state is the "0" -state.

Next, the principle of the write operation for the TMR element will be briefly described with reference to FIG.

The TMR element is a write word line and a data selection line (read / write bit line) which intersect each other.
It is located at the intersection with. Writing is accomplished by passing a current through the write word line and the data selection line and using the magnetic field created by the current flowing through both wirings to make the spin directions of the TMR element parallel or antiparallel.

For example, when the easy axis of magnetization of the TMR element is in the X direction, the write word line extends in the X direction, and the data selection line extends in the Y direction orthogonal to the X direction, the write word line is connected to the write word line during writing. , A current flowing in one direction and a current flowing in one direction or the other direction are supplied to the data selection line according to write data.

When a current flowing in one direction is passed through the data selection line, the spin directions of the TMR element are parallel ("1" -state). On the other hand, when a current flowing in the other direction is passed through the data selection line, the spin directions of the TMR element are antiparallel (“0” -state).

The mechanism of changing the spin direction of the TMR element is as follows.

As shown in the TMR curve of FIG. 99, the TMR
When a magnetic field Hx is applied in the long side (Easy-Axis) direction of the element,
The resistance value of the TMR element changes, for example, by about 17%.
This rate of change, that is, the ratio of the resistance values before and after the change is called the MR ratio.

The MR ratio changes depending on the properties of the magnetic layer. At present, a TMR element having an MR ratio of about 50% is also obtained.

The TMR element has a magnetic field H in the Easy-Axis direction.
A synthetic magnetic field of x and the magnetic field Hy in the Hard-Axis direction is applied.
As shown by the solid line in FIG. 100, the magnetic field H in the Hard-Axis direction
Depending on the magnitude of y, the magnitude of the magnetic field Hx in the Easy-Axis direction required to change the resistance value of the TMR element also changes. By utilizing this phenomenon, it is possible to write data only to the TMR element existing at the intersection of the selected write word line and the selected data selection line among the memory cells arranged in an array.

This situation will be further described with reference to the asteroid curve shown in FIG. The asteroid curve of the TMR element is, for example, as shown by the solid line in FIG. That is,
If the magnitude of the combined magnetic field of the magnetic field Hx in the Easy-Axis direction and the magnetic field Hy in the Hard-Axis direction is outside the asteroid curve (solid line) (for example, the position of the black circle), the spin direction of the magnetic layer is reversed. Can be made.

On the contrary, the magnetic field Hx in the Easy-Axis direction and the Hard-Ax
When the magnitude of the combined magnetic field with the magnetic field Hy in the is direction is inside the asteroid curve (solid line) (for example, the position of the white circle), the spin direction of the magnetic layer cannot be reversed.

Therefore, by changing the magnitude of the magnetic field Hx in the Easy-Axis direction and the magnitude of the magnetic field Hy in the Hard-Axis direction and changing the position of the magnitude of the synthetic magnetic field in the Hx-Hy plane, the data for the TMR element is changed. Can control the writing of.

The reading can be easily performed by passing a current through the selected TMR element and detecting the resistance value of the TMR element.

For example, a switch element is connected in series to the TMR element, and only the switch element connected to the selected read word line is turned on to form a current path. As a result, current flows only in the selected TMR element,
The data of the TMR element can be read.

[0021]

In the magnetic random access memory, as described above, the data write is generated by applying a write current to each of the write word line and the data selection line (read / write bit line). The combined magnetic field is applied to the TMR element.

Therefore, in order to write data efficiently, it is important to efficiently apply this combined magnetic field to the TMR element. If the combined magnetic field is efficiently applied to the TMR element, the reliability of the write operation can be improved, the write current can be reduced, and the power consumption can be reduced.

However, a device structure effective for causing the combined magnetic field generated by the write currents respectively flowing in the write word line and the data selection line to act on the TMR element efficiently has not been sufficiently studied. That is, it is necessary to consider such a device structure from the viewpoint of the manufacturing process, in which not only the synthetic magnetic field is effectively applied to the TMR element but also it can be easily manufactured.

The present invention has been made to solve such a problem, and an object thereof is to allow a synthetic magnetic field to efficiently act on a TMR element during a write operation in a magnetic random access memory. It is to propose a device structure and a manufacturing method thereof.

[0025]

Means for Solving the Problems (1) A magnetic random access memory according to the present invention is formed on a semiconductor substrate and has a memory cell for storing data by utilizing a magnetoresistive effect and a memory cell directly under the memory cell. A first write line which is arranged and extends in a first direction, a second write line which is arranged immediately above the memory cell and which extends in a second direction intersecting the first direction, and a side surface of the first write line. , The first
A first yoke material that is recessed below the upper surface of the write line.

The first yoke material covers only the side surface of the first write line. The first yoke material covers the lower surface of the first write line.

The magnetic random access memory of the present invention comprises:
A second yoke material covering a part of the surface of the second write line is further provided. The second yoke material covers the upper surface and the side surface of the second write line. The second yoke material is
Only the upper surface of the second write line is covered. The second
The yoke material covers only the side surface of the second write line.

One of the first and second write lines is electrically connected to the memory cell and also functions as a read bit line.

A magnetic random access memory according to the present invention is formed on a semiconductor substrate, stores a data by utilizing a magnetoresistive effect, and a memory cell, which is arranged immediately below the memory cell and extends in a first direction. 1 write line,
A second write line, which is arranged immediately above the memory cell and extends in a second direction intersecting the first direction, covers a side surface of the second write line, and is recessed above a lower surface of the second write line. And a first yoke material that is present.

The first yoke material covers only the side surface of the second write line. The first yoke material covers the upper surface of the second write line.

The magnetic random access memory of the present invention comprises:
A second yoke material that covers a part of the surface of the first write line is further provided. The second yoke material covers the lower surface and the side surface of the first write line. The second yoke material is
Only the lower surface of the first write line is covered. The second
The yoke material covers only the side surface of the first write line.

One of the first and second write lines is electrically connected to the memory cell and also functions as a read bit line.

A magnetic random access memory according to the present invention includes first and second memory cells stacked on a semiconductor substrate to store data by utilizing a magnetoresistive effect.
A first write line that is disposed between the first and second memory cells and extends in a first direction, and covers only a side surface of the first write line, and is recessed below an upper surface of the first write line; And a first yoke material that is recessed above the lower surface of the first write line.

The second memory cell is arranged above the first memory cell. The magnetic random access memory according to the present invention is arranged immediately below the first memory cell, is arranged immediately above the second write line extending in a second direction intersecting the first direction, and is arranged immediately above the second memory cell, And a third write line extending in the second direction.

The magnetic random access memory of the present invention comprises:
A second yoke material that covers only the side surface of the second write line and is recessed below the upper surface of the second write line, and covers only the side surface of the third write line, and the bottom surface of the third write line. And a third yoke member recessed in the upper part.

The first write line is connected to the first and second write lines.
It is far from the memory cell. The first write line is in contact with the first and second memory cells.

The magnetic random access memory according to the present invention includes a plurality of memory cells arranged on the upper side of a semiconductor substrate in a direction parallel to the surface of the semiconductor substrate and storing data by utilizing a magnetoresistive effect. A first write line shared by a plurality of memory cells and extending in a first direction;
A plurality of second write lines extending in a second direction intersecting the direction, and a side surface of the first write line only, and the plurality of memory cell sides of the first write line being closer to the plurality of memory cells than the plurality of memory cell sides. With respect to the first yoke material that is recessed on the opposite side, and only the side surfaces of the plurality of second write lines are covered, and the plurality of memory cell sides of the second write lines are closer to the plurality of memory cell sides than the plurality of memory cell side surfaces. On the other hand, the second yoke member is recessed on the opposite side.

The first write line is arranged immediately above the plurality of memory cells and is in contact with one end of the plurality of memory cells. The other ends of the plurality of memory cells are commonly connected. The plurality of second write lines are arranged immediately below the plurality of memory cells and are separated from the plurality of memory cells.

The first write line is arranged immediately above the plurality of memory cells and is separated from the plurality of memory cells. The plurality of second write lines are arranged immediately below the plurality of memory cells and are in contact with one ends of the plurality of memory cells. The other ends of the plurality of memory cells are commonly connected.

(2) In the method of manufacturing a magnetic random access memory according to the present invention, a step of forming an insulating layer on a semiconductor substrate, a step of forming a wiring groove in the insulating layer, and a bottom and side wall of the wiring groove A step of forming a yoke material on the portion,
A step of filling a conductive material in the wiring groove to form a write line; a step of etching a part of the yoke material to lower the yoke material below an upper surface of the write line; And a step of forming a TMR element immediately above.

The yoke material is formed on the insulating layer and on the bottom and side walls of the wiring groove by the CVD method, and then left on the bottom and side walls of the wiring groove by the CMP method.

After the conductive material is formed on the insulating layer and in the wiring groove by the CVD method, it is left only in the wiring groove by the CMP method.

A method of manufacturing a magnetic random access memory according to the present invention includes a step of forming an insulating layer on a semiconductor substrate, a step of forming a wiring groove in the insulating layer, and a yoke material only on a side wall portion of the wiring groove. And a step of forming a write line by filling the wiring groove with a conductive material,
The method includes the steps of etching a part of the yoke material to recess the yoke material below the upper surface of the write line, and forming a TMR element directly above the write line.

The yoke material is formed on the insulating layer and on the bottom and side walls of the wiring groove by the CVD method, and is then left only on the side wall portion of the wiring groove by the RIE method.

After the conductive material is formed on the insulating layer and in the wiring groove by the CVD method, it is left only in the wiring groove by the CMP method.

A method of manufacturing a magnetic random access memory according to the present invention comprises a step of forming a TMR element on a semiconductor substrate, a step of forming a first insulating layer on the TMR element, and a step of forming the first insulating layer on the TMR element. A step of forming a wiring groove in the first insulating layer; a step of forming a second insulating layer only on the side wall portion of the wiring groove; a step of filling the wiring groove with a conductive material to form a write line; A step of etching a part of the second insulating layer to leave the second insulating layer only near the lower surface of the write line; and forming a yoke material on the side wall of the wiring groove from which the second insulating layer is removed. And a process.

The yoke material is formed on the side wall of the wiring groove and also on the upper surface of the write line.

The yoke material is formed on the side wall of the wiring groove, the first insulating layer and the write line by the CVD method, and then left on the side wall of the wiring groove by the CMP method.

The yoke material is formed on the side wall of the wiring groove, the first insulating layer and the write line by the CVD method, and then left on the side wall of the wiring groove by the RIE method.

The yoke material is formed on the side wall of the wiring groove, the first insulating layer and the write line by the CVD method, and then formed on the side wall of the wiring groove and the write line by the RIE method. Can be left behind.

The etching amount of the second insulating layer is determined on the condition that the lower surface of the yoke material is arranged between the upper surface and the lower surface of the write line.

After the conductive material is formed on the insulating layer and in the wiring groove by the CVD method, it is left only in the wiring groove by the CMP method.

A method of manufacturing a magnetic random access memory according to the present invention comprises a step of forming a TMR element on a semiconductor substrate, a step of forming an insulating layer on the TMR element, and a step of forming an insulating layer on the TMR element. Forming a wiring groove; filling the wiring groove with a conductive material to form a write line; and etching a part of the insulating layer so that the insulating layer remains only near the lower surface of the write line. And a step of forming a yoke material on the side surface of the write line exposed by removing the insulating layer.

The yoke material is formed on the insulating layer and the upper surface and the side surface of the write line by the CVD method, and then left on only the side surface of the write line by the RIE method.

The etching amount of the insulating layer is determined under the condition that the lower surface of the yoke material is arranged between the upper surface and the lower surface of the write line.

After the conductive material is formed on the insulating layer and in the wiring groove by the CVD method, it is left only in the wiring groove by the CMP method.

[0057]

DETAILED DESCRIPTION OF THE INVENTION An example of a magnetic random access memory of the present invention will be described in detail below with reference to the drawings.

1. Reference Example 1 First, in explaining an example of the magnetic random access memory of the present invention, a device structure which is a premise thereof will be described.

This device structure is shown for the purpose of briefly explaining an example of the magnetic random access memory of the present invention, and the present invention is not limited to this device structure.

1 and 2 each show a device structure which is a premise of an example of the magnetic random access memory of the present invention.

A semiconductor substrate (eg, p-type silicon substrate,
STI (Shallow Tr
An element isolation insulating layer 12 having an ench Isolation structure is formed. The region surrounded by the element isolation insulating layer 12 is an element region where a read selection switch (eg, MOS transistor, diode, etc.) is formed.

In the device structure of FIG. 1, the read selection switch is composed of a MOS transistor (n-channel type MOS transistor). On the semiconductor substrate 11,
Gate insulating layer 13, gate electrode 14 and sidewall insulating layer 15
Is formed. The gate electrode 14 extends in the X direction and functions as a read word line for selecting a read cell (TMR element) during a read operation.

In the semiconductor substrate 11, a source region (eg, n-type diffusion layer) 16-S and a drain region (eg, n-type diffusion layer) 16-S.
n-type diffusion layer) 16-D is formed. The gate electrode (read word line) 14 is arranged on the channel region between the source region 16-S and the drain region 16-D.

In the device structure of FIG. 2, the read selection switch is composed of a diode. Semiconductor substrate 11
A cathode region (for example, n-type diffusion layer) 16a and an anode region (for example, p-type diffusion layer) 16b are formed therein.

One of the metal layers forming the first metal wiring layer functions as the intermediate layer 18A for vertically stacking a plurality of contact plugs, and the other one is the source line 1.
8B (for FIG. 1) or read word line 18B (for FIG. 2).
In the case of).

In the case of the device structure of FIG. 1, the intermediate layer 18A
Are electrically connected to the drain region 16-D of the read selection switch (MOS transistor) by the contact plug 17A. The source line 18B is electrically connected to the source region 16-S of the read selection switch by the contact plug 17B. The source line 18B extends in the X direction similarly to the gate electrode (read word line) 14.

In the case of the device structure of FIG. 2, the intermediate layer 18A
Are electrically connected to the anode region 16b of the read selection switch (diode) by the contact plug 17A. The read word line 18B is electrically connected to the cathode region 16a of the read selection switch by the contact plug 17B. Read word line 18B
Extends in the X direction.

One of the metal layers forming the second metal wiring layer functions as an intermediate layer 20A for vertically stacking a plurality of contact plugs, and the other one functions as a write word line 20B. . The intermediate layer 20A is electrically connected to the intermediate layer 18A by the contact plug 19. The write word line 20B extends in the X direction, for example.

One of the metal layers forming the third metal wiring layer functions as the lower electrode 22 of the TMR element 23. The lower electrode 22 is electrically connected to the intermediate layer 20A by the contact plug 21. The TMR element 23 is
It is mounted on the lower electrode 22. Here, the TMR element 23
Are arranged immediately above the write word line 20B and are formed in a rectangular shape (the easy axis of magnetization is in the X direction) long in the X direction.

One of the metal layers forming the fourth metal wiring layer is a data selection line (read / write bit line).
Function as 24. The data selection line 24 is electrically connected to the TMR element 23 and extends in the Y direction.

Regarding the structure of the TMR element 23,
There is no particular limitation. The structure shown in FIG. 96 may be used, or another structure may be used. Also, TMR
The element 23 may be a multi-value storage type capable of storing a plurality of bits of data.

The ferromagnetic layer of the TMR element 23 is not particularly limited, but for example, Fe, Co, Ni or their alloys, magnetite having a large spin polarization, CrO ₂ ,
RXMnO _3-y (R: rare earth, X: Ca, Ba, S
In addition to oxides such as r), Heusler alloys such as NiMnSb and PtMnSb can be used.

The ferromagnetic layer includes Ag, Cu, Au, Al,
Mg, Si, Bi, Ta, B, C, O, N, Pd, P
Even if a small amount of non-magnetic element such as t, Zr, Ir, W, Mo, Nb is contained, there is no problem as long as ferromagnetism is not lost.

If the ferromagnetic layer is too thin, it becomes superparamagnetic. Therefore, the thickness of the ferromagnetic layer needs to be at least such that superparamagnetism does not occur. Specifically, the thickness of the ferromagnetic layer is set to 0.1 nm or more, preferably 0.4 nm to 100 nm.

The diamagnetic layer of the TMR element 23 is, for example, Fe-Mn, Pt-Mn, Pt-Cr-Mn, Ni.
-Mn, Ir-Mn, NiO, or the like can be used _Fe 2 _{O 3.}

Insulating layer of TMR element 23 (tunnel barrier)
For example, Al ₂ O ₃ , SiO ₂ , MgO, A
1N, Bi ₂ O ₃ , MgF ₂ , CaF ₂ , SrTi
Dielectrics such as O ₂ and AlLaO ₃ can be used. These may have oxygen deficiency, nitrogen deficiency, fluorine deficiency or the like.

The thickness of the insulating layer (tunnel barrier) is preferably as thin as possible, but there is no particular limitation for realizing its function. However, in manufacturing, the thickness of the insulating layer is set to 10 nm or less.

2. Reference Example 2 Next, a device structure proposed for efficiently concentrating a magnetic field in a TMR element will be described with respect to the device structure of Reference Example 1.

3 to 6 show a device structure which is a premise of an example of the magnetic random access memory of the present invention. 3 and 5 are cross sections in the Y direction.
6 is a cross section in the X direction of the TMR element portion of FIG.
5 is a cross section of the TMR element portion in FIG. 5 in the X direction. The X direction and the Y direction are orthogonal to each other.

A semiconductor substrate (eg, p-type silicon substrate,
STI (Shallow Tr
An element isolation insulating layer 12 having an ench Isolation structure is formed. A region surrounded by the element isolation insulating layer 12 becomes an element region in which a read selection switch (eg, MOS transistor) is formed.

In the device structure of this example, the read selection switch is composed of a MOS transistor (n-channel type MOS transistor). On the semiconductor substrate 11,
Gate insulating layer 13, gate electrode 14 and sidewall insulating layer 15
Is formed. The gate electrode 14 extends in the X direction and functions as a read word line for selecting a read cell (TMR element) during a read operation.

In the semiconductor substrate 11, a source region (eg, n-type diffusion layer) 16-S and a drain region (eg, n-type diffusion layer) 16-S.
n-type diffusion layer) 16-D is formed. The gate electrode (read word line) 14 is arranged on the channel region between the source region 16-S and the drain region 16-D.

One of the metal layers forming the first metal wiring layer functions as the intermediate layer 18A for vertically stacking a plurality of contact plugs, and the other one is the source line 1.
It functions as 8B.

The intermediate layer 18A is a contact plug 17A.
Read selection switch (MOS transistor)
Is electrically connected to the drain region 16-D. The source line 18B is electrically connected to the source region 16-S of the read selection switch by the contact plug 17B. The source line 18B extends in the X direction, like the gate electrode (read word line) 14, for example.

One of the metal layers forming the second metal wiring layer functions as an intermediate layer 20A for vertically stacking a plurality of contact plugs, and the other one functions as a write word line 20B. . The intermediate layer 20A is electrically connected to the intermediate layer 18A by the contact plug 19. The write word line 20B extends in the X direction, like the gate electrode (read word line) 14, for example.

In the device structure of this example, the lower surface and the side surface of the intermediate layer 20A and the write word line 20B have a high magnetic permeability, that is, a yoke material.
It is covered with 25A and 25B. The yoke materials 25A and 25B used here are limited to those having conductivity.

Since the magnetic flux has a property of concentrating on a material having a high magnetic permeability, if a material having a high magnetic permeability is used as a pulling force of a magnetic force line, a write current flowing through the write word line 20B during a write operation causes The generated magnetic field Hy can be efficiently concentrated on the TMR element 23.

To achieve the object of the present application, the yoke material is
It is sufficient if it covers the lower surface and the side surface of the write word line 20B. However, in reality, the yoke material is the intermediate layer 2
It is also formed on the lower surface and side surface of 0A. This is the intermediate layer 20A as the second metal wiring layer and the write word line 20.
This is because B is formed at the same time.

One of the metal layers forming the third metal wiring layer functions as the lower electrode 22 of the TMR element 23. The lower electrode 22 is electrically connected to the intermediate layer 20A by the contact plug 21. The TMR element 23 is
It is mounted on the lower electrode 22. Here, the TMR element 23
Are arranged immediately above the write word line 20B and are formed in a rectangular shape (the easy axis of magnetization is in the X direction) long in the X direction.

One of the metal layers forming the fourth metal wiring layer is a data selection line (read / write bit line).
Function as 24. The data selection line 24 is electrically connected to the TMR element 23 and extends in the Y direction.

In the device structure of this example, the data selection line 2
The upper and side surfaces of 4 are made of a material having a high magnetic permeability, that is,
It is covered with the yoke members 26 and 27. The yoke members 26 and 27 used here can be made of a conductive material as shown in FIGS. 3 and 4, and also have an insulating property as shown in FIGS. It can also be composed of a material having

As described above, the magnetic flux has a property of being concentrated in a material having a high magnetic permeability. Therefore, if this material having a high magnetic permeability is used as a pulling force of the magnetic line of force, the data selection line 24 is operated during the write operation. The magnetic field Hx generated by the write current flowing in the TMR element 23 can be efficiently concentrated in the TMR element 23.

Regarding the structure of the TMR element 23,
There is no particular limitation. The structure shown in FIG. 96 may be used, or another structure may be used. Also, TMR
The element 23 may be a multi-value storage type capable of storing a plurality of bits of data.

In such a device structure, TM
Write word line 20B arranged directly under the R element 23
On the other hand, the yoke material 25B is formed on the lower surface and the side surface thereof. Further, with respect to the data selection line (read / write bit line) 24 arranged immediately above the TMR element 23, yoke materials 226 and 27 are formed on the upper and side surfaces thereof.

In this case, the write word line 20B and the yoke material 25B are formed by damascene process (damascene process).
It is convenient to adopt ss) to form. Conversely, the write word line 20B and the yoke material 25B are
It is practically impossible to adopt the IE process (Reactive Ion Etching process) so that the process becomes very complicated.

On the other hand, the data selection line 24 and the yoke material 2
6 and 27 may employ either the damascene process or the RIE process.

3. First Embodiment FIGS. 7 to 10 show a device structure according to a first embodiment of the magnetic random access memory of the present invention. 7 and 9 are cross sections in the Y direction, FIG. 8 is a cross section in the X direction of the TMR element part of FIG. 7, and FIG. 10 is a cross section of the TMR element part in FIG. 9 in the X direction. is there. The X direction and the Y direction are orthogonal to each other.

The device structure of this example is characterized in that the write word line 20B arranged immediately below the TMR element 23 is covered with a yoke material 25B on its lower surface and side surface.
Regarding the data selection line (read / write bit line) 24 arranged immediately above the R element 23, the upper and side surfaces thereof are covered with the yoke members 26 and 27.

Further, the yoke material 25B arranged on the side surface of the write word line 20B arranged directly below the TMR element 23 is characterized in that it has a structure depressed below the upper surface of the write line 20B.

A semiconductor substrate (eg, p-type silicon substrate,
STI (Shallow Tr
An element isolation insulating layer 12 having an ench Isolation structure is formed. The region surrounded by the element isolation insulating layer 12 becomes an element region where the read selection switch is formed.

In the device structure of this example, the read selection switch is composed of a MOS transistor (n-channel type MOS transistor). On the semiconductor substrate 11,
Gate insulating layer 13, gate electrode 14 and sidewall insulating layer 15
Is formed. The gate electrode 14 extends in the X direction and functions as a read word line for selecting a read cell (TMR element) during a read operation.

In the semiconductor substrate 11, a source region (eg, n-type diffusion layer) 16-S and a drain region (eg, n-type diffusion layer) 16-S.
n-type diffusion layer) 16-D is formed. The gate electrode (read word line) 14 is arranged on the channel region between the source region 16-S and the drain region 16-D.

One of the metal layers forming the first metal wiring layer functions as an intermediate layer 18A for vertically stacking a plurality of contact plugs, and the other one is the source line 1.
It functions as 8B.

The intermediate layer 18A is the contact plug 17A.
Read selection switch (MOS transistor)
Is electrically connected to the drain region 16-D. The source line 18B is electrically connected to the source region 16-S of the read selection switch by the contact plug 17B. The source line 18B extends in the X direction, like the gate electrode (read word line) 14, for example.

One of the metal layers forming the second metal wiring layer functions as an intermediate layer 20A for vertically stacking a plurality of contact plugs, and the other one functions as a write word line 20B. . The intermediate layer 20A is electrically connected to the intermediate layer 18A by the contact plug 19. The write word line 20B extends in the X direction, like the gate electrode (read word line) 14, for example.

In the device structure of this example, the lower surface and the side surface of the intermediate layer 20A and the write word line 20B have a material having a high magnetic permeability, that is, a yoke material.
It is covered with 25A and 25B. The yoke materials 25A and 25B used here are limited to those having conductivity.

Further, the yoke materials 25A and 25B arranged on the side surfaces of the intermediate layer 20A and the write word line 20B are recessed below the upper surfaces of the intermediate layer 20A and the write word line 20B. That is, the yoke material 25A,
Since 25B does not come too close to the TMR element 23, it is possible to reduce the possibility that the write word line 20B and the TMR element 23 are short-circuited.

Since the magnetic flux has a property of concentrating on a material having a high magnetic permeability, if a material having a high magnetic permeability is used as a pulling force of the magnetic force lines, it is possible to
The magnetic field Hy generated by the write current flowing in the write word line 20B can be efficiently concentrated in the TMR element 23.

To achieve the object of the present application, the yoke material is
It is sufficient if it covers the lower surface and the side surface of the write word line 20B. However, in reality, the yoke material is the intermediate layer 2
It is also formed on the lower surface and side surface of 0A. This is the intermediate layer 20A as the second metal wiring layer and the write word line 20.
This is because B is formed at the same time.

One of the metal layers forming the third metal wiring layer functions as the lower electrode 22 of the TMR element 23. The lower electrode 22 is electrically connected to the intermediate layer 20A by the contact plug 21. The TMR element 23 is
It is mounted on the lower electrode 22. Here, the TMR element 23
Are arranged immediately above the write word line 20B and are formed in a rectangular shape (the easy axis of magnetization is in the X direction) long in the X direction.

One of the metal layers forming the fourth metal wiring layer is a data selection line (read / write bit line).
Function as 24. The data selection line 24 is electrically connected to the TMR element 23 and extends in the Y direction.

In the device structure of this example, the data selection line 2
The upper and side surfaces of 4 are made of a material having a high magnetic permeability, that is,
It is covered with the yoke members 26 and 27. The yoke materials 26 and 27 used here can be made of a material having conductivity as shown in FIGS. 7 and 8, and also have insulating properties as shown in FIGS. 9 and 10. It can also be composed of a material having

As described above, since the magnetic flux has a property of being concentrated in a material having a high magnetic permeability, if this material having a high magnetic permeability is used as a pulling force of the lines of magnetic force, it is possible to select data during a write operation. The magnetic field Hx generated by the write current flowing through the line 24 can be efficiently concentrated on the TMR element 23.

Regarding the structure of the TMR element 23,
Not limited. The structure shown in FIG. 96 may be used, or another structure may be used. In addition, the TMR element 2
3 may be a multi-value storage type capable of storing a plurality of bits of data.

In such a device structure, TM
Write word line 20B arranged directly under the R element 23
On the other hand, the yoke material 25B is formed on the lower surface and the side surface thereof. Further, with respect to the data selection line (read / write bit line) 24 arranged immediately above the TMR element 23, yoke materials 26 and 27 are formed on the upper and side surfaces thereof. Further, the yoke material 25B on the side surface of the write word line 20B is recessed below the upper surface of the write word line 20B.

Therefore, the magnetic field generated by the write current flowing through the write word line 20B and the data selection line 24 can be efficiently applied to the TMR element 23.

Although the yoke materials 26 and 27 are formed on the upper surface and the side surface of the data selection line 24 in this example, the present invention is not limited to this, and the following may be adopted.

For example, the yoke material 27 may be formed only on the upper surface of the data selection line 24 as shown in FIGS. 11 to 14, or as shown in FIGS. The yoke material 26 may be formed only on the side surface thereof.

Further, the write word line 20B and the yoke material 25B are formed by damascene process.
) Is adopted and it is convenient to form. Conversely, the write word line 20B and the yoke material 25B are
It is practically impossible to adopt the IE process (Reactive Ion Etching process) so that the process becomes very complicated.

Further, the data selection line 24 and the yoke material 2
As for 6 and 27, either the damascene process or the RIE process may be adopted.

4. Second Embodiment FIGS. 19 to 22 show a device structure according to a second embodiment of the magnetic random access memory of the present invention. Note that FIG. 19 and FIG. 21 are cross sections in the Y direction, and FIG.
2 is a cross section in the X direction of the TMR element portion of FIG.
2 is a cross section in the X direction of the TMR element portion in FIG. X
The direction and the Y direction are orthogonal to each other.

The device structure of this example is characterized in that the write word line 20B arranged immediately below the TMR element 23 is covered with a yoke material 25B on the lower surface and the side surface thereof.
Regarding the data selection line (read / write bit line) 24 arranged immediately above the R element 23, the upper and side surfaces thereof are covered with the yoke members 26 and 27.

Further, the yoke material 26 arranged on the side surface of the data selection line 24 arranged right above the TMR element 23 is characterized in that it has a structure dented above the lower surface of the data selection line 24. .

A semiconductor substrate (for example, a p-type silicon substrate,
STI (Shallow Tr
An element isolation insulating layer 12 having an ench Isolation structure is formed. The region surrounded by the element isolation insulating layer 12 becomes an element region where the read selection switch is formed.

In the device structure of this example, the read selection switch is composed of a MOS transistor (n-channel type MOS transistor). On the semiconductor substrate 11,
Gate insulating layer 13, gate electrode 14 and sidewall insulating layer 15
Is formed. The gate electrode 14 extends in the X direction and functions as a read word line for selecting a read cell (TMR element) during a read operation.

In the semiconductor substrate 11, a source region (eg, n-type diffusion layer) 16-S and a drain region (eg, n-type diffusion layer) 16-S.
n-type diffusion layer) 16-D is formed. The gate electrode (read word line) 14 is arranged on the channel region between the source region 16-S and the drain region 16-D.

One of the metal layers forming the first metal wiring layer functions as the intermediate layer 18A for vertically stacking a plurality of contact plugs, and the other one is the source line 1.
It functions as 8B.

The intermediate layer 18A is the contact plug 17A.
Read selection switch (MOS transistor)
Is electrically connected to the drain region 16-D. The source line 18B is electrically connected to the source region 16-S of the read selection switch by the contact plug 17B. The source line 18B extends in the X direction, like the gate electrode (read word line) 14, for example.

One of the metal layers constituting the second metal wiring layer functions as an intermediate layer 20A for vertically stacking a plurality of contact plugs, and the other one functions as a write word line 20B. . The intermediate layer 20A is electrically connected to the intermediate layer 18A by the contact plug 19. The write word line 20B extends in the X direction, like the gate electrode (read word line) 14, for example.

In the device structure of this example, the lower surface and the side surface of the intermediate layer 20A and the write word line 20B are made of a material having a high magnetic permeability, that is, a yoke material.
It is covered with 25A and 25B. The yoke materials 25A and 25B used here are limited to those having conductivity.

Since the magnetic flux has a property of being concentrated in a material having a high magnetic permeability, if this material having a high magnetic permeability is used as a pulling force of the magnetic force lines, the writing operation is
The magnetic field Hy generated by the write current flowing in the write word line 20B can be efficiently concentrated in the TMR element 23.

To achieve the object of the present application, the yoke material is
It is sufficient if it covers the lower surface and the side surface of the write word line 20B. However, in reality, the yoke material is the intermediate layer 2
It is also formed on the lower surface and side surface of 0A. This is the intermediate layer 20A as the second metal wiring layer and the write word line 20.
This is because B is formed at the same time.

One of the metal layers forming the third metal wiring layer functions as the lower electrode 22 of the TMR element 23. The lower electrode 22 is electrically connected to the intermediate layer 20A by the contact plug 21. The TMR element 23 is
It is mounted on the lower electrode 22. Here, the TMR element 23
Are arranged immediately above the write word line 20B and are formed in a rectangular shape (the easy axis of magnetization is in the X direction) long in the X direction.

One of the metal layers forming the fourth metal wiring layer is a data selection line (read / write bit line).
Function as 24. The data selection line 24 is electrically connected to the TMR element 23 and extends in the Y direction.

In the device structure of this example, the data selection line 2
The upper and side surfaces of 4 are made of a material having a high magnetic permeability, that is,
It is covered with the yoke members 26 and 27. The yoke materials 26 and 27 used here can be made of a material having conductivity as shown in FIGS. 19 and 20, and also have insulating properties as shown in FIGS. 21 and 22. It can also be composed of a material having

The yoke material 26 arranged on the side surface of the data selection line 24 is recessed above the lower surface of the data selection line 24. That is, the yoke material 26 is TMR
It does not approach the element 23 too much.

As described above, the magnetic flux has a property of being concentrated in a material having a high magnetic permeability. Therefore, if this material having a high magnetic permeability is used as a pulling force of the magnetic lines of force, the data selection during the write operation is performed. The magnetic field Hx generated by the write current flowing through the line 24 can be efficiently concentrated on the TMR element 23.

Regarding the structure of the TMR element 23,
Not limited. The structure shown in FIG. 96 may be used, or another structure may be used. In addition, the TMR element 2
3 may be a multi-value storage type capable of storing a plurality of bits of data.

In such a device structure, TM
Write word line 20B arranged directly under the R element 23
On the other hand, the yoke material 25B is formed on the lower surface and the side surface thereof. Further, with respect to the data selection line (read / write bit line) 24 arranged immediately above the TMR element 23, yoke materials 26 and 27 are formed on the upper and side surfaces thereof. Further, the yoke material 26 on the side surface of the data selection line 24 is recessed above the lower surface of the data selection line 24.

Therefore, the magnetic field generated by the write current flowing through the write word line 20B and the data selection line 24 can be efficiently applied to the TMR element 23.

In this example, the write word line 20B
In contrast, although the yoke material 25B is formed on the lower surface and the side surface thereof, the present invention is not limited to this, and the following may be adopted.

For example, for the write word line 20B, the yoke material 25B may be formed only on the lower surface thereof as shown in FIGS. 23 to 26, or as shown in FIGS. 27 to 30. The yoke material 25B may be formed only on the side surface thereof.

In addition, the write word line 20B and the yoke material 25B are formed by the damascene process (damascene process).
) Is adopted and it is convenient to form. Conversely, the write word line 20B and the yoke material 25B are
It is practically impossible to adopt the IE process (Reactive Ion Etching process) so that the process becomes very complicated.

Further, the data selection line 24 and the yoke material 2
It is convenient to adopt the damascene process for forming 6 and 27. Conversely, the data selection line 24
It is practically impossible to form the yoke materials 26 and 27 by adopting the RIE process because the process becomes very complicated.

5. Third Embodiment FIGS. 31 to 34 show a device structure according to a third embodiment of the magnetic random access memory of the present invention. 31 and 33 are cross sections in the Y direction.
3 is a cross section in the X direction of the TMR element portion of FIG.
4 is a cross section in the X direction of the TMR element portion of FIG. X
The direction and the Y direction are orthogonal to each other.

The feature of the device structure of this example is that the write word line 20B arranged immediately below the TMR element 23 is covered with a yoke material 25B on the lower surface and the side surface thereof.
Regarding the data selection line (read / write bit line) 24 arranged immediately above the R element 23, the upper and side surfaces thereof are covered with the yoke members 26 and 27.

Further, with respect to the yoke material 25B arranged on the side surface of the write word line 20B arranged directly below the TMR element 23, the yoke material 25B has a structure depressed below the upper surface of the write line 20B, and the TMR element. The yoke material 26 disposed on the side surface of the data selection line 24 disposed directly above 23 is characterized in that it has a structure recessed above the lower surface of the data selection line 24.

A semiconductor substrate (eg, p-type silicon substrate,
STI (Shallow Tr
An element isolation insulating layer 12 having an ench Isolation structure is formed. The region surrounded by the element isolation insulating layer 12 becomes an element region where the read selection switch is formed.

In the device structure of this example, the read selection switch is composed of a MOS transistor (n-channel type MOS transistor). On the semiconductor substrate 11,
Gate insulating layer 13, gate electrode 14 and sidewall insulating layer 15
Is formed. The gate electrode 14 extends in the X direction and functions as a read word line for selecting a read cell (TMR element) during a read operation.

In the semiconductor substrate 11, a source region (eg, n-type diffusion layer) 16-S and a drain region (eg, n-type diffusion layer) 16-S.
n-type diffusion layer) 16-D is formed. The gate electrode (read word line) 14 is arranged on the channel region between the source region 16-S and the drain region 16-D.

One of the metal layers forming the first metal wiring layer functions as the intermediate layer 18A for vertically stacking a plurality of contact plugs, and the other one is the source line 1.
It functions as 8B.

The intermediate layer 18A is the contact plug 17A.
Read selection switch (MOS transistor)
Is electrically connected to the drain region 16-D. The source line 18B is electrically connected to the source region 16-S of the read selection switch by the contact plug 17B. The source line 18B extends in the X direction, like the gate electrode (read word line) 14, for example.

One of the metal layers constituting the second metal wiring layer functions as an intermediate layer 20A for vertically stacking a plurality of contact plugs, and the other one functions as a write word line 20B. . The intermediate layer 20A is electrically connected to the intermediate layer 18A by the contact plug 19. The write word line 20B extends in the X direction, like the gate electrode (read word line) 14, for example.

In the device structure of this example, the lower surface and the side surface of the intermediate layer 20A and the write word line 20B are made of a material having a high magnetic permeability, that is, a yoke material.
It is covered with 25A and 25B. The yoke materials 25A and 25B used here are limited to those having conductivity.

Further, the yoke materials 25A and 25B arranged on the side surfaces of the intermediate layer 20A and the write word line 20B are recessed below the upper surfaces of the intermediate layer 20A and the write word line 20B. That is, the yoke material 25A,
Since 25B does not come too close to the TMR element 23, it is possible to reduce the possibility that the write word line 20B and the TMR element 23 are short-circuited.

Since the magnetic flux has a property of concentrating on a material having a high magnetic permeability, if a material having a high magnetic permeability is used as a pulling force of the magnetic force lines, it is
The magnetic field Hy generated by the write current flowing in the write word line 20B can be efficiently concentrated in the TMR element 23.

To achieve the object of the present application, the yoke material is
It is sufficient if it covers the lower surface and the side surface of the write word line 20B. However, in reality, the yoke material is the intermediate layer 2
It is also formed on the lower surface and side surface of 0A. This is the intermediate layer 20A as the second metal wiring layer and the write word line 20.
This is because B is formed at the same time.

One of the metal layers forming the third metal wiring layer functions as the lower electrode 22 of the TMR element 23. The lower electrode 22 is electrically connected to the intermediate layer 20A by the contact plug 21. The TMR element 23 is
It is mounted on the lower electrode 22. Here, the TMR element 23
Are arranged immediately above the write word line 20B and are formed in a rectangular shape (the easy axis of magnetization is in the X direction) long in the X direction.

One of the metal layers forming the fourth metal wiring layer is a data selection line (read / write bit line).
Function as 24. The data selection line 24 is electrically connected to the TMR element 23 and extends in the Y direction.

In the device structure of this example, the data selection line 2
The upper and side surfaces of 4 are made of a material having a high magnetic permeability, that is,
It is covered with the yoke members 26 and 27. The yoke materials 26 and 27 used here can be made of a material having conductivity as shown in FIGS. 31 and 32, and can be made of insulating material as shown in FIGS. 33 and 34. It can also be composed of a material having

The yoke material 26 arranged on the side surface of the data selection line 24 is recessed above the lower surface of the data selection line 24. That is, the yoke material 26 is TMR
It does not approach the element 23 too much.

As described above, the magnetic flux has a property of being concentrated in a material having a high magnetic permeability. Therefore, if this material having a high magnetic permeability is used as a pulling force of the magnetic lines of force, the data selection during the write operation is performed. The magnetic field Hx generated by the write current flowing through the line 24 can be efficiently concentrated on the TMR element 23.

Regarding the structure of the TMR element 23,
Not limited. The structure shown in FIG. 96 may be used, or another structure may be used. In addition, the TMR element 2
3 may be a multi-value storage type capable of storing a plurality of bits of data.

In such a device structure, TM
Write word line 20B arranged directly under the R element 23
On the other hand, the yoke material 25B is formed on the lower surface and the side surface thereof. Further, with respect to the data selection line (read / write bit line) 24 arranged immediately above the TMR element 23, yoke materials 26 and 27 are formed on the upper and side surfaces thereof. Further, the yoke material 25B on the side surface of the write word line 20B is recessed below the upper surface of the write word line 20B, and the yoke material 26 on the side surface of the data selection line 24.
Regarding the data selection line 24, it is recessed above the lower surface of the data selection line 24.

Therefore, the magnetic field generated by the write current flowing in the write word line 20B and the data selection line 24 can be efficiently applied to the TMR element 23.

The write word line 20B and the yoke material 25B are damascene process (damascene process).
) Is adopted and it is convenient to form. Conversely, the write word line 20B and the yoke material 25B are
It is practically impossible to adopt the IE process (Reactive Ion Etching process) so that the process becomes very complicated.

Further, the data selection line 24 and the yoke material 2
It is convenient to adopt the damascene process for forming 6 and 27. Conversely, the data selection line 24
It is practically impossible to form the yoke materials 26 and 27 by adopting the RIE process because the process becomes very complicated.

6. Fourth Embodiment FIGS. 35 to 38 show a device structure according to a fourth embodiment of the magnetic random access memory of the present invention. Note that FIG. 35 and FIG. 37 are cross-sections in the Y direction.
3 is a cross section in the X direction of the TMR element portion of FIG.
8 is a cross section in the X direction of the TMR element portion of FIG. X
The direction and the Y direction are orthogonal to each other.

The feature of the device structure of this example is that the write word line 20B arranged directly below the TMR element 23 is covered with the yoke material 25B only on its side surface, and the data selection line arranged directly above the TMR element 23. Regarding the (read / write bit line) 24, the upper and side surfaces thereof are covered with the yoke members 26 and 27.

Further, the yoke material 25B arranged on the side surface of the write word line 20B arranged directly below the TMR element 23 is characterized in that it has a structure depressed below the upper surface of the write line 20B.

A semiconductor substrate (eg, p-type silicon substrate,
STI (Shallow Tr
An element isolation insulating layer 12 having an ench Isolation structure is formed. The region surrounded by the element isolation insulating layer 12 becomes an element region where the read selection switch is formed.

In the device structure of this example, the read selection switch is composed of a MOS transistor (n-channel type MOS transistor). On the semiconductor substrate 11,
Gate insulating layer 13, gate electrode 14 and sidewall insulating layer 15
Is formed. The gate electrode 14 extends in the X direction and functions as a read word line for selecting a read cell (TMR element) during a read operation.

In the semiconductor substrate 11, a source region (for example, n-type diffusion layer) 16-S and a drain region (for example, n-type diffusion layer) 16-S.
n-type diffusion layer) 16-D is formed. The gate electrode (read word line) 14 is arranged on the channel region between the source region 16-S and the drain region 16-D.

One of the metal layers forming the first metal wiring layer functions as the intermediate layer 18A for vertically stacking a plurality of contact plugs, and the other one is the source line 1.
It functions as 8B.

The intermediate layer 18A is the contact plug 17A.
Read selection switch (MOS transistor)
Is electrically connected to the drain region 16-D. The source line 18B is electrically connected to the source region 16-S of the read selection switch by the contact plug 17B. The source line 18B extends in the X direction, like the gate electrode (read word line) 14, for example.

One of the metal layers forming the second metal wiring layer functions as an intermediate layer 20A for vertically stacking a plurality of contact plugs, and the other one functions as a write word line 20B. . The intermediate layer 20A is electrically connected to the intermediate layer 18A by the contact plug 19. The write word line 20B extends in the X direction, like the gate electrode (read word line) 14, for example.

In the device structure of this example, the side surfaces of the intermediate layer 20A and the write word line 20B are made of a material having a high magnetic permeability, that is, a yoke material 25A,
It is covered by 25B. The yoke members 25A and 25B used here can be made of a conductive material, as shown in FIGS.
As shown in FIGS. 37 and 38, it may be made of an insulating material.

Further, the yoke materials 25A and 25B arranged on the side surfaces of the intermediate layer 20A and the write word line 20B are recessed below the upper surfaces of the intermediate layer 20A and the write word line 20B. That is, the yoke material 25A,
Since 25B does not come too close to the TMR element 23, it is possible to reduce the possibility that the write word line 20B and the TMR element 23 are short-circuited.

Since the magnetic flux has a property of being concentrated in a material having a high magnetic permeability, if a material having a high magnetic permeability is used as a pulling force of the magnetic force lines, it is possible to
The magnetic field Hy generated by the write current flowing in the write word line 20B can be efficiently concentrated in the TMR element 23.

To achieve the object of the present application, the yoke material is
It is sufficient if the side surface of the write word line 20B is covered. However, in reality, the yoke material is also formed on the side surface of the intermediate layer 20A. This is because the intermediate layer 20A as the second metal wiring layer and the write word line 20B are simultaneously formed.

One of the metal layers forming the third metal wiring layer functions as the lower electrode 22 of the TMR element 23. The lower electrode 22 is electrically connected to the intermediate layer 20A by the contact plug 21. The TMR element 23 is
It is mounted on the lower electrode 22. Here, the TMR element 23
Are arranged immediately above the write word line 20B and are formed in a rectangular shape (the easy axis of magnetization is in the X direction) long in the X direction.

One of the metal layers forming the fourth metal wiring layer is a data selection line (read / write bit line).
Function as 24. The data selection line 24 is electrically connected to the TMR element 23 and extends in the Y direction.

In the device structure of this example, the data selection line 2
The upper and side surfaces of 4 are made of a material having a high magnetic permeability, that is,
It is covered with the yoke members 26 and 27. The yoke members 26 and 27 used here can be made of a conductive material as shown in FIGS. 35 and 36, and can be made of an insulating material as shown in FIGS. 37 and 38. It can also be composed of a material having

Since the magnetic flux has the property of being concentrated in a material having a high magnetic permeability as described above, if this material having a high magnetic permeability is used as a pulling force of the magnetic force lines, the data selection during the write operation is performed. The magnetic field Hx generated by the write current flowing through the line 24 can be efficiently concentrated on the TMR element 23.

Regarding the structure of the TMR element 23,
Not limited. The structure shown in FIG. 96 may be used, or another structure may be used. In addition, the TMR element 2
3 may be a multi-value storage type capable of storing a plurality of bits of data.

In such a device structure, TM
Write word line 20B arranged directly under the R element 23
On the other hand, a yoke material 25B is formed on the side surface thereof.
Further, with respect to the data selection line (read / write bit line) 24 arranged immediately above the TMR element 23, yoke materials 26 and 27 are formed on the upper and side surfaces thereof. Further, the yoke material 25B on the side surface of the write word line 20B is recessed below the upper surface of the write word line 20B.

Therefore, the magnetic field generated by the write current flowing in the write word line 20B and the data selection line 24 can be efficiently applied to the TMR element 23.

In this example, the yoke members 26 and 27 are formed on the upper surface and the side surface of the data selection line 24, but the present invention is not limited to this, and the following may be adopted.

For example, for the data selection line 24, the yoke material 27 may be formed only on the upper surface thereof as shown in FIGS. 39 to 42, or as shown in FIGS. 43 to 46. The yoke material 26 may be formed only on the side surface thereof.

Further, the write word line 20B and the yoke material 25B are formed by the damascene process (damascene process).
) Is adopted and it is convenient to form. Conversely, the write word line 20B and the yoke material 25B are
It is practically impossible to adopt the IE process (Reactive Ion Etching process) so that the process becomes very complicated.

In addition, the data selection line 24 and the yoke material 2
As for 6 and 27, either the damascene process or the RIE process may be adopted.

7. Fifth Embodiment FIGS. 47 to 50 show a device structure according to a fifth embodiment of the magnetic random access memory of the present invention. 47 and 49 are cross sections in the Y direction.
5 is a cross section in the X direction of the TMR element portion of FIG.
0 is a cross section in the X direction of the TMR element portion in FIG. X
The direction and the Y direction are orthogonal to each other.

The feature of the device structure of this example is that the write word line 20B arranged immediately below the TMR element 23 is covered with the yoke material 25B on the lower surface and the side surface thereof.
Regarding the data selection line (read / write bit line) 24 arranged directly above the R element 23, only the side surface thereof is covered with the yoke material 26.

Further, the yoke material 26 arranged on the side surface of the data selection line 24 arranged right above the TMR element 23 is characterized in that it has a structure dented above the lower surface of the data selection line 24. .

A semiconductor substrate (eg, p-type silicon substrate,
STI (Shallow Tr
An element isolation insulating layer 12 having an ench Isolation structure is formed. The region surrounded by the element isolation insulating layer 12 becomes an element region where the read selection switch is formed.

In the device structure of this example, the read selection switch is composed of a MOS transistor (n-channel type MOS transistor). On the semiconductor substrate 11,
Gate insulating layer 13, gate electrode 14 and sidewall insulating layer 15
Is formed. The gate electrode 14 extends in the X direction and functions as a read word line for selecting a read cell (TMR element) during a read operation.

In the semiconductor substrate 11, a source region (for example, n-type diffusion layer) 16-S and a drain region (for example, n-type diffusion layer) 16-S.
n-type diffusion layer) 16-D is formed. The gate electrode (read word line) 14 is arranged on the channel region between the source region 16-S and the drain region 16-D.

One of the metal layers forming the first metal wiring layer functions as the intermediate layer 18A for vertically stacking a plurality of contact plugs, and the other one is the source line 1.
It functions as 8B.

The intermediate layer 18A is the contact plug 17A.
Read selection switch (MOS transistor)
Is electrically connected to the drain region 16-D. The source line 18B is electrically connected to the source region 16-S of the read selection switch by the contact plug 17B. The source line 18B extends in the X direction, like the gate electrode (read word line) 14, for example.

One of the metal layers forming the second metal wiring layer functions as an intermediate layer 20A for vertically stacking a plurality of contact plugs, and the other one functions as a write word line 20B. . The intermediate layer 20A is electrically connected to the intermediate layer 18A by the contact plug 19. The write word line 20B extends in the X direction, like the gate electrode (read word line) 14, for example.

In the device structure of this example, the lower surface and the side surface of the intermediate layer 20A and the write word line 20B are made of a material having a high magnetic permeability, that is, a yoke material.
It is covered with 25A and 25B. The yoke materials 25A and 25B used here are limited to those having conductivity.

Since the magnetic flux has a property of being concentrated on a material having a high magnetic permeability, if a material having a high magnetic permeability is used as a pulling force of the magnetic lines of force, a write operation is performed.
The magnetic field Hy generated by the write current flowing in the write word line 20B can be efficiently concentrated in the TMR element 23.

To achieve the object of the present application, the yoke material is
It is sufficient if it covers the lower surface and the side surface of the write word line 20B. However, in reality, the yoke material is the intermediate layer 2
It is also formed on the lower surface and side surface of 0A. This is the intermediate layer 20A as the second metal wiring layer and the write word line 20.
This is because B is formed at the same time.

One of the metal layers forming the third metal wiring layer functions as the lower electrode 22 of the TMR element 23. The lower electrode 22 is electrically connected to the intermediate layer 20A by the contact plug 21. The TMR element 23 is
It is mounted on the lower electrode 22. Here, the TMR element 23
Are arranged immediately above the write word line 20B and are formed in a rectangular shape (the easy axis of magnetization is in the X direction) long in the X direction.

One of the metal layers forming the fourth metal wiring layer is a data selection line (read / write bit line).
Function as 24. The data selection line 24 is electrically connected to the TMR element 23 and extends in the Y direction.

In the device structure of this example, the data selection line 2
The side surface of No. 4 is covered with a material having a high magnetic permeability, that is, a yoke material 26. Yoke material used here 2
As shown in FIG. 47 and FIG. 48, 6 can be made of a conductive material, and FIG.
Also, as shown in FIG. 50, it may be made of an insulating material.

Further, the yoke material 26 arranged on the side surface of the data selection line 24 is recessed above the lower surface of the data selection line 24. That is, the yoke material 26 is TMR
It does not approach the element 23 too much.

As described above, the magnetic flux has a property of being concentrated in a material having a high magnetic permeability. Therefore, if this material having a high magnetic permeability is used as a pulling force of the magnetic lines of force, the data selection is performed during the writing operation. The magnetic field Hx generated by the write current flowing through the line 24 can be efficiently concentrated on the TMR element 23.

Regarding the structure of the TMR element 23,
Not limited. The structure shown in FIG. 96 may be used, or another structure may be used. In addition, the TMR element 2
3 may be a multi-value storage type capable of storing a plurality of bits of data.

In such a device structure, TM
Write word line 20B arranged directly under the R element 23
On the other hand, the yoke material 25B is formed on the lower surface and the side surface thereof. Further, the yoke material 26 is formed only on the side surface of the data selection line (read / write bit line) 24 arranged immediately above the TMR element 23. Further, the yoke material 26 on the side surface of the data selection line 24 is recessed above the lower surface of the data selection line 24.

Therefore, the magnetic field generated by the write current flowing through the write word line 20B and the data selection line 24 can be efficiently applied to the TMR element 23.

In this example, the write word line 20B
In contrast, although the yoke material 25B is formed on the lower surface and the side surface thereof, the present invention is not limited to this, and the following may be adopted.

For example, for the write word line 20B, the yoke material 25B may be formed only on the lower surface thereof as shown in FIGS. 51 to 54, or as shown in FIGS. 55 to 58. The yoke material 25B may be formed only on the side surface thereof.

Further, the write word line 20B and the yoke material 25B are formed by the damascene process (damascene process).
) Is adopted and it is convenient to form. Conversely, the write word line 20B and the yoke material 25B are
It is practically impossible to adopt the IE process (Reactive Ion Etching process) so that the process becomes very complicated.

The data selection line 24 and the yoke material 26 are also included.
Also, it is convenient to adopt the damascene process. Conversely, it is practically impossible to form the data selection line 24 and the yoke material 26 by adopting the RIE process because the process becomes very complicated.

8. Sixth Embodiment FIGS. 59 to 62 show a device structure relating to a sixth embodiment of the magnetic random access memory of the present invention. 59 and 61 are cross-sections in the Y direction.
6 is a cross section in the X direction of the TMR element portion of FIG.
2 is a cross section in the X direction of the TMR element portion of FIG. X
The direction and the Y direction are orthogonal to each other.

The device structure of this example is characterized in that the write word line 20B arranged directly below the TMR element 23 is covered with the yoke material 25B only on its side surface and the data selection line arranged directly above the TMR element 23. Regarding the (read / write bit line) 24, only the side surface thereof is covered with the yoke material 26.

Further, with respect to the yoke material 25B arranged on the side surface of the write word line 20B arranged directly below the TMR element 23, it has a structure recessed below the upper surface of the write line 20B, and the TMR element. The yoke material 26 disposed on the side surface of the data selection line 24 disposed directly above 23 is characterized in that it has a structure recessed above the lower surface of the data selection line 24.

A semiconductor substrate (eg, p-type silicon substrate,
STI (Shallow Tr
An element isolation insulating layer 12 having an ench Isolation structure is formed. The region surrounded by the element isolation insulating layer 12 becomes an element region where the read selection switch is formed.

In the device structure of this example, the read selection switch is composed of a MOS transistor (n-channel type MOS transistor). On the semiconductor substrate 11,
Gate insulating layer 13, gate electrode 14 and sidewall insulating layer 15
Is formed. The gate electrode 14 extends in the X direction and functions as a read word line for selecting a read cell (TMR element) during a read operation.

In the semiconductor substrate 11, the source region (eg, n-type diffusion layer) 16-S and the drain region (eg, n-type diffusion layer) 16-S.
n-type diffusion layer) 16-D is formed. The gate electrode (read word line) 14 is arranged on the channel region between the source region 16-S and the drain region 16-D.

One of the metal layers constituting the first metal wiring layer functions as the intermediate layer 18A for vertically stacking a plurality of contact plugs, and the other one is the source line 1.
It functions as 8B.

The intermediate layer 18A is the contact plug 17A.
Read selection switch (MOS transistor)
Is electrically connected to the drain region 16-D. The source line 18B is electrically connected to the source region 16-S of the read selection switch by the contact plug 17B. The source line 18B extends in the X direction, like the gate electrode (read word line) 14, for example.

One of the metal layers forming the second metal wiring layer functions as an intermediate layer 20A for vertically stacking a plurality of contact plugs, and the other one functions as a write word line 20B. . The intermediate layer 20A is electrically connected to the intermediate layer 18A by the contact plug 19. The write word line 20B extends in the X direction, like the gate electrode (read word line) 14, for example.

In the device structure of this example, the side surfaces of the intermediate layer 20A and the write word line 20B are made of a material having a high magnetic permeability, that is, a yoke material 25A,
It is covered by 25B. The yoke members 25A and 25B used here can be made of a conductive material as shown in FIGS. 59 and 60, and
As shown in FIGS. 61 and 62, it may be made of an insulating material.

Further, the yoke members 25A and 25B arranged on the side surfaces of the intermediate layer 20A and the write word line 20B are recessed below the upper surfaces of the intermediate layer 20A and the write word line 20B. That is, the yoke material 25A,
Since 25B does not come too close to the TMR element 23, it is possible to reduce the possibility that the write word line 20B and the TMR element 23 are short-circuited.

Since the magnetic flux has a property of being concentrated in a material having a high magnetic permeability, if this material having a high magnetic permeability is used as a pulling force of the magnetic force lines, the writing operation is
The magnetic field Hy generated by the write current flowing in the write word line 20B can be efficiently concentrated in the TMR element 23.

To achieve the object of the present application, the yoke material is
It is sufficient if the side surface of the write word line 20B is covered. However, in reality, the yoke material is also formed on the side surface of the intermediate layer 20A. This is because the intermediate layer 20A as the second metal wiring layer and the write word line 20B are simultaneously formed.

One of the metal layers forming the third metal wiring layer functions as the lower electrode 22 of the TMR element 23. The lower electrode 22 is electrically connected to the intermediate layer 20A by the contact plug 21. The TMR element 23 is
It is mounted on the lower electrode 22. Here, the TMR element 23
Are arranged immediately above the write word line 20B and are formed in a rectangular shape (the easy axis of magnetization is in the X direction) long in the X direction.

One of the metal layers forming the fourth metal wiring layer is a data selection line (read / write bit line).
Function as 24. The data selection line 24 is electrically connected to the TMR element 23 and extends in the Y direction.

In the device structure of this example, the data selection line 2
The side surface of No. 4 is covered with a material having a high magnetic permeability, that is, a yoke material 26. Yoke material used here 2
As shown in FIGS. 59 and 60, 6 can be made of a conductive material, and FIG.
Further, as shown in FIG. 62, it may be made of an insulating material.

Further, the yoke material 26 arranged on the side surface of the data selection line 24 is recessed above the lower surface of the data selection line 24. That is, the yoke material 26 is TMR
It does not approach the element 23 too much.

Since the magnetic flux has the property of being concentrated in a material having a high magnetic permeability as described above, if a material having a high magnetic permeability is used as a pulling force of the magnetic lines of force, the data selection during the write operation is performed. The magnetic field Hx generated by the write current flowing through the line 24 can be efficiently concentrated on the TMR element 23.

Regarding the structure of the TMR element 23,
Not limited. The structure shown in FIG. 96 may be used, or another structure may be used. In addition, the TMR element 2
3 may be a multi-value storage type capable of storing a plurality of bits of data.

In such a device structure, TM
Write word line 20B arranged directly under the R element 23
On the other hand, the yoke material 25B is formed only on the side surface thereof. Further, for the data selection line (read / write bit line) 24 arranged immediately above the TMR element 23,
The yoke material 26 is formed only on the side surface. Further, the yoke material 25B on the side surface of the write word line 20B is recessed below the upper surface of the write word line 20B,
The yoke material 26 on the side surface of the data selection line 24 is recessed above the lower surface of the data selection line 24.

Therefore, the magnetic field generated by the write current flowing in the write word line 20B and the data selection line 24 can be efficiently applied to the TMR element 23.

The write word line 20B and the yoke material 25B are damascene process (damascene process).
) Is adopted and it is convenient to form. Conversely, the write word line 20B and the yoke material 25B are
It is practically impossible to adopt the IE process (Reactive Ion Etching process) so that the process becomes very complicated.

In addition, the data selection line 24 and the yoke material 26
Also, it is convenient to adopt the damascene process. Conversely, it is practically impossible to form the data selection line 24 and the yoke material 26 by adopting the RIE process because the process becomes very complicated.

9. Examples 7 to 12 Next, Examples 7 to 12 as improved examples of the device structure according to Examples 4 to 6 will be described.

The characteristics of the device structures of Examples 7 to 12 are that the TMR elements are stacked in a plurality of stages (Example 7).
-10) or when a plurality of TMR elements are arranged in the lateral direction (Examples 11 and 12), one TMR element shares one write line and the side surface of the write line has a high magnetic permeability. It is the point covered with the yoke material.

(1) Seventh Embodiment FIGS. 63 and 64 show the device structure of the magnetic random access memory according to the seventh embodiment of the present invention.

In the device structure of this example, the semiconductor substrate 11
Two TMR elements 23 are stacked on top of each other, and these two TMR elements 23 share one data selection line (read / write bit line) 24.

The data selection line 24 is arranged between the two TMR elements and extends in the Y direction. Also, one TM
The R element 23 is in contact with the lower surface of the data selection line 24, and the other one TMR element 23 is in contact with the upper surface of the data selection line 24. The side surface of the data selection line 24 is covered with a yoke material 26 having high magnetic permeability.

The yoke material 26 is recessed below the upper surface of the data selection line 24 and above the lower surface of the data selection line 24.

In the write operation, a write current flows through the data selection line 24. The magnetic field generated by this write current is efficiently applied to the TMR element 23 by the yoke material 26.

Directly below or above the TMR element 23 is a write word line 20B extending in the X direction orthogonal to the Y direction. The side surface of the write word line 20B is covered with a yoke material 25B having high magnetic permeability.

The yoke material 25B is used for the write word line 20.
Write word line 2 which is recessed below the upper surface of B
It is recessed above the lower surface of OB.

In the write operation, the write word line 2
A write current flows in 0B. The magnetic field generated by this write current is efficiently transferred to the T
It is applied to the MR element 23.

The yoke members 25B and 26 may be made of a conductive material as shown in FIG.
As shown in FIG. 4, it may be made of an insulating material.

(2) Eighth Embodiment FIGS. 65 and 66 show the device structure of the magnetic random access memory according to the eighth embodiment of the present invention.

In the device structure of this example, the semiconductor substrate 11
Four TMR elements 23 are stacked on top. Two of these TMR elements 23 are connected to one write word line 20B or one data selection line (read / read).
The write bit line) 24 is shared.

The data selection line 24 has two TMR elements 2
It is arranged between 3 and extends in the Y direction. Further, one TMR element 23 contacts the lower surface of the data selection line 24,
The other one TMR element 23 is in contact with the upper surface of the data selection line 24. The side surface of the data selection line 24 is covered with a yoke material 26 having high magnetic permeability.

The yoke material 26 is recessed below the upper surface of the data selection line 24 and above the lower surface of the data selection line 24.

In the write operation, a write current flows through the data selection line 24. The magnetic field generated by this write current is efficiently applied to the TMR element 23 by the yoke material 26.

Between the TMR element 23 in contact with the lower surface of the upper data selection line 24 and the TMR element 23 in contact with the upper surface of the lower data selection line 24, there is an X direction orthogonal to the Y direction. One extending write word line 20B is arranged. This write word line 20B is shared by these two TMR elements. The side surface of the write word line 20B is covered with a yoke material 25B having high magnetic permeability.

In addition, in the X direction, a portion directly above the TMR element 23 which is in contact with the upper surface of the upper data selection line 24 and a portion immediately below the TMR element 23 which is in contact with the lower surface of the lower data selection line 24 are respectively in the X direction. Write word line 20B extending
Are placed. The side surface of the write word line 20B is covered with a yoke material 25B having high magnetic permeability.

The yoke material 25B is used for the write word line 20.
Write word line 2 which is recessed below the upper surface of B
It is recessed above the lower surface of OB.

In the write operation, the write word line 2
A write current flows in 0B. The magnetic field generated by this write current is efficiently transferred to the T
It is applied to the MR element 23.

The yoke members 25B and 26 may be made of a conductive material as shown in FIG.
As shown in FIG. 6, it may be made of an insulating material.

(3) Ninth Embodiment FIGS. 67 to 70 show a device structure relating to a ninth embodiment of the magnetic random access memory of the present invention.

In the device structure of this example, the semiconductor substrate 11
Four TMR elements 23 connected in series are stacked on top of each other. One end of these TMR elements 23 connected in series is connected to the read selection switch RSW, and the other end is connected to the read bit line BL. These TMR
Two of the elements 23 are connected to one write word line 20.
B, or one write bit line 24 is shared.

The write bit line 24 is arranged between the two TMR elements 23 and extends in the Y direction. The side surface of the write bit line 24 has a yoke material 26 having a high magnetic permeability.
Are covered by. The yoke material 26 is recessed below the upper surface of the write bit line 24 and recessed above the lower surface of the write bit line 24.

In the write operation, the write bit line 2
A write current flows through 4. The magnetic field generated by the write current is efficiently transferred to the TMR by the yoke material 26.
It is applied to the element 23.

The write word line 20B has two TMRs.
It is arranged between the elements 23 and extends in the X direction orthogonal to the Y direction. The side surface of the write word line 20B is covered with a yoke material 25B having high magnetic permeability. The write word line 20B is arranged directly below or above the TMR element 23 and extends in the X direction. The side surface of the write word line 20B is covered with a yoke material 25B having high magnetic permeability.

The yoke material 25B is used for the write word line 20.
Write word line 2 which is recessed below the upper surface of B
It is recessed above the lower surface of OB.

In the write operation, the write word line 2
A write current flows in 0B. The magnetic field generated by this write current is efficiently transferred to the T
It is applied to the MR element 23.

The yoke members 25B and 26 may be made of a conductive material as shown in FIGS. 67 and 68, or may be made of an insulating material as shown in FIGS. 69 and 70. Good.

(4) Tenth Embodiment FIGS. 71 to 74 show the device structure of the magnetic random access memory according to the tenth embodiment of the present invention.

In the device structure of this example, the semiconductor substrate 11
Four TMR elements 23 connected in parallel are stacked on top of each other. One end of these TMR elements 23 connected in parallel is connected to the read selection switch RSW, and the other end is connected to the read bit line BL. These TMR
Two of the elements 23 are connected to one write word line 20.
B, or one write bit line 24 is shared.

The write bit line 24 is arranged between the two TMR elements 23 and extends in the Y direction. The side surface of the write bit line 24 has a yoke material 26 having a high magnetic permeability.
Are covered by. The yoke material 26 is recessed below the upper surface of the write bit line 24 and recessed above the lower surface of the write bit line 24.

In the write operation, the write bit line 2
A write current flows through 4. The magnetic field generated by the write current is efficiently transferred to the TMR by the yoke material 26.
It is applied to the element 23.

The write word line 20B has two TMRs.
It is arranged between the elements 23 and extends in the X direction orthogonal to the Y direction. The side surface of the write word line 20B is covered with a yoke material 25B having high magnetic permeability. The write word line 20B is arranged directly below or above the TMR element 23 and extends in the X direction. The side surface of the write word line 20B is covered with a yoke material 25B having high magnetic permeability.

The yoke material 25B is used for the write word line 20.
Write word line 2 which is recessed below the upper surface of B
It is recessed above the lower surface of OB.

At the time of write operation, write word line 2
A write current flows in 0B. The magnetic field generated by this write current is efficiently transferred to the T
It is applied to the MR element 23.

The yoke members 25B and 26 may be made of a conductive material as shown in FIGS. 71 and 72, or may be made of an insulating material as shown in FIGS. 73 and 74. Good.

(5) Embodiment 11 FIGS. 75 and 76 show the device structure relating to Embodiment 11 of the magnetic random access memory of the present invention.

In the device structure of this example, the semiconductor substrate 11
In the upper direction, lateral direction (direction parallel to the surface of the semiconductor substrate)
A plurality of (four in this example) TMR elements 23 are arranged in each. One ends of these TMR elements 23 are commonly connected to a read selection switch RSW, and the other ends are commonly connected to a data selection line (read / write bit line) 24. These TMR elements 23 share one data selection line (read / write bit line) 24.

The data selection line 24 has a plurality of TMR elements 2
It is arranged directly above 3 and extends in the Y direction. The side surface of the data selection line 24 is covered with a yoke material 26 having high magnetic permeability. The yoke material 26 is recessed above the lower surface of the data selection line 24. A write current flows through the data selection line 24 during a write operation. The magnetic field generated by this write current is efficiently applied to the TMR element 23 by the yoke material 26.

The write word line 20B is connected to the TMR element 2
It is arranged immediately below 3 and extends in the X direction orthogonal to the Y direction. The side surface of the write word line 20B is covered with a yoke material 25B having high magnetic permeability. York material 25
B is recessed below the upper surface of the write word line 20B.

At the time of write operation, write word line 2
A write current flows in 0B. The magnetic field generated by this write current is efficiently transferred to the T
It is applied to the MR element 23.

The yoke members 25B and 26 may be made of a conductive material as shown in FIG.
As shown in FIG. 6, it may be made of an insulating material.

(6) Twelfth Embodiment FIGS. 77 and 78 show the device structure of a magnetic random access memory according to the twelfth embodiment of the present invention.

In the device structure of this example, the semiconductor substrate 11
In the upper direction, lateral direction (direction parallel to the surface of the semiconductor substrate)
A plurality of (four in this example) TMR elements 23 are arranged in each. One ends of these TMR elements 23 are commonly connected to a read selection switch RSW, and the other ends are independently connected to a data selection line (read bit line / write word line) 20B.

The TMR elements 23 share one write bit line 24. Write bit line 24
Are arranged immediately above the plurality of TMR elements 23 and extend in the Y direction. The side surface of the write bit line 24 is covered with a yoke material 26 having a high magnetic permeability. York material 2
6 is recessed above the lower surface of the data selection line 24. A write current flows through the write bit line 24 during a write operation. The magnetic field generated by this write current is efficiently transferred to the TMR element 23 by the yoke material 26.
Applied to.

The data selection line 20B is arranged immediately below the TMR element 23 and extends in the X direction orthogonal to the Y direction. The side surface of the data selection line 20B is covered with a yoke material 25B having high magnetic permeability. The yoke material 25B is
It is recessed below the upper surface of the write word line 20B.

In the write operation, the data selection line 20B
Write current flows to. The magnetic field generated by this write current is efficiently transferred to the TMR by the yoke material 25B.
It is applied to the element 23.

The yoke members 25B and 26 may be made of a conductive material as shown in FIG.
As shown in FIG. 8, it may be made of an insulating material.

10. An example of a memory cell array structure (circuit structure) realized by the device structures according to the reference examples 1 and 2 and the embodiments 1 to 12 will be described.

FIG. 79 shows the main part of the memory cell array structure of the magnetic random access memory.

Since this cell array structure is premised on that the easy axis of magnetization of the TMR element is oriented in the Y direction, the direction of the write current flowing through the write word line changes according to the write data.

Control signals φ1, φ31, φ32, φ33
Are N-channel MOS transistors QN1, QN31,
By controlling ON / OFF of QN32 and QN33, data selection lines (read / write bit lines) BL1, BL2
It is determined whether or not a current is passed through BL3. Data selection line B
The current drive power supply 40 is connected to one end (on the N-channel MOS transistor QN1 side) of L1, BL2, BL3. The current drive power source 40 is configured by the data selection lines BL1 and BL.
2, the potential at one end of BL3 is set to Vy.

N-channel MOS transistor QN31,
QN32 and QN33 are data selection lines BL1, BL2,
It is connected between the other end of BL3 and the ground point Vss.

In the write operation, the control signal φ1
Becomes "H" level and control signals φ31 and φ3
One of 2 and φ33 becomes the “H” level. For example, when data is written to the TMR element of the memory cell MC1, as shown in the timing chart of FIG. 80, the control signals φ1 and φ31 are at the “H” level, so that a current flows through the data selection line BL1. Flowing. At this time, the control signals φ41, φ42, φ43 are at the “L” level.

Further, Vx1 is a current drive power supply potential for "1" -writing, and Vx2 is a current drive power supply potential for "0" -writing.

For example, at the time of "1" -writing, FIG.
As shown in, the control signals φ5 and φ11 are set to the “H” level. At this time, the control signals φ6 and φ12 are at “L” level. Therefore, a current flows in the write word line WWL1 from left to right (from the current drive power supply 41 to the ground point). Therefore, the memory cell MC arranged at the intersection of the data selection line BL1 and the write word line WWL1.
"1" -data is written in the TMR element of 1.

At the time of "0" -write, the control signals φ6 and φ11 are set to "H" level as shown in FIG. At this time, the control signals φ5 and φ12 are at “L” level. Therefore, a current flows through the write word line WWL1 from right to left (from the ground point Vss to the current drive power supply 42). Therefore, "0" -data is written in the TMR element of the memory cell MC1 arranged at the intersection of the data selection line BL1 and the write word line WWL1.

As described above, during the write operation, the control signal φ1 is used to supply the drive current to all the data selection lines, and the control signals φ31, φ32, φ33 are used.
Is used to select a data selection line through which a drive current flows. In this example, the direction of the drive current flowing through the data selection line is constant. The control signals φ5 and φ6 are used to control the direction of the current flowing through the write word line (corresponding to the write data), and the control signals φ11 and φ1.
2 is used to select a write word line through which a drive current flows.

In this example, in order to simplify the explanation, 3 × 2
It is assumed that the memory cell array of. Write word lines WWL1, WWL2 and data selection lines BL1, BL2
A memory cell (TMR element) is arranged at each intersection of BL3. Here, in order to read the data stored in the memory cell MC1, the control signals φ21, φ2
2, φ41, φ42, and φ43 are controlled as follows.

That is, during the read operation, the control signal φ21 applied to the read word line RWL1 is set to the “H” level, and the N channel MO connected to the read word line RWL1.
The S transistor is turned on. At this time, the control signal φ22 given to the other read word line RWL2 is “L”.
It is a level.

When the control signal φ41 is set to "H" level and the other control signals φ42 and φ43 are set to "L" level, the memory cell MC1 (N-channel MOS transistor and TMR element) and data selection from the read power supply 43. A drive current flows toward the ground point via the line BL1, the N-channel MOS transistor QN41 and the detection resistor Rs.

Therefore, the detection voltage Vo according to the data value of the memory cell MC1 is generated across the detection resistor Rs. This detection voltage Vo is, for example, sense amplifier S / A
Memory cell (TMR element)
The data of can be read.

11. Manufacturing Method Next, the manufacturing method of the main ones of the device structures according to Reference Examples 1 and 2 and Examples 1 to 12 will be described in detail.

(1) Method for Manufacturing Device Structure According to Example 3 First, as shown in FIG. 81, PEP (Photo Engraving)
Process) method, CVD (Chemical Vapor Deposition)
The element isolation insulating layer 12 having the STI structure is formed in the semiconductor substrate 11 by using a well-known method such as the CMP (Chemical Mechanical Polishing) method.

Further, a MOS transistor as a read selection switch is formed in the element region surrounded by the element isolation insulating layer 12.

The MOS transistor is formed by the CVD method or PEP.
Method and RIE (Reactive Ion Etching) method, gate insulating layer 13 and gate electrode (read word line) 14
After the formation of the source region, the source region 16-
It can be easily formed by forming the S and drain regions 16-D. In addition, on the side wall of the gate electrode 14,
The sidewall insulating layer 15 may be formed by the CVD method and the RIE method.

Thereafter, the insulating layer 28A which completely covers the MOS transistor is formed by the CVD method. Also, CM
The surface of the insulating layer 28A is flattened by using the P method. PE
Using the P method and the RIE method, the MOS is formed in the insulating layer 28A.
Contact holes reaching the source diffusion layer 16-S and the drain diffusion layer 16-D of the transistor are formed.

A barrier metal (for example, T) is formed on the insulating layer 28A and the inner surface of the contact hole by the sputtering method.
a (15 nm) and TaN (15 nm) stack) 51 is formed. Subsequently, a conductive material (for example, a conductive polysilicon film containing impurities, a metal film, etc.) that completely fills the contact hole is formed on the insulating layer 28A. Then, the conductive material and the barrier metal 51 are polished by the CMP method to form the contact plugs 17A and 17B.

The insulating layer 28B is formed on the insulating layer 28A by the CVD method. A wiring groove is formed in the insulating layer 28B by using the PEP method and the RIE method. A barrier metal (for example, a stack of Ta and TaN) 52 is formed on the insulating layer 28B and the inner surface of the wiring groove by the sputtering method. Subsequently, a conductive material (for example, a metal film of aluminum, copper, or the like) that completely fills the wiring groove is formed on the insulating layer 28B by the sputtering method. After that, the conductive material and the barrier metal 52 are polished by CMP to form the intermediate layer 18A and the source line 18B.

Subsequently, the insulating layer 28B is formed by the CVD method.
An insulating layer 28C is formed thereover. By using the PEP method and the RIE method, a via hole is formed in the insulating layer 28C.
e) is formed. A barrier metal (for example, T) is formed on the insulating layer 28C and on the inner surface of the via hole by the sputtering method.
A laminated layer 53 of Ta and TaN) 53 is formed. Subsequently, a conductive material (for example, a metal film such as aluminum or copper) that completely fills the via hole is formed on the insulating layer 28C by the sputtering method.
To form. After that, the conductive material and the barrier metal 53 are polished by the CMP method to form the via plug 19.

Next, as shown in FIG. 82, the insulating layer 29 is formed on the insulating layer 28C by the CVD method. PE
A wiring groove is formed in the insulating layer 29 by using the P method and the RIE method. Using a sputtering method, a yoke material (for example, NiF) having high magnetic permeability is formed on the insulating layer 29 and in the wiring groove.
e) Form 25 with a thickness of about 20 nm.

A barrier metal (eg, a barrier metal) is formed on the insulating layer 28C and on the inner surface of the via hole by the sputtering method.
A Ta / TaN stack) 54 is formed. Then, using a sputtering method, a conductive material that completely fills the wiring groove (for example,
Aluminum, copper, or their alloys (AlCu) etc.) 2
Form 0.

When the conductive material is made of copper (Cu), this conductive layer is formed of, for example, Cu of about 80 nm.
After forming the seed layer, a sufficiently thick (for example, about 800 nm) Cu layer may be stacked on the Cu seed layer by a plating method.

Thereafter, the conductive material 20 and the barrier metal 54 are polished by CMP to form the intermediate layer 20A and the write word line 20B (see FIG. 83).

In this example, as shown in FIG.
After leaving 0A and 20B only in the wiring groove, the yoke material 25 of FIG. 82 is polished by etching or CMP. The yoke materials 25A and 25B are polished under the condition that the upper surfaces thereof are arranged below the upper surface of the insulating layer 29 (or the upper surfaces of the conductive materials 20A and 20B). Through these steps, the yoke material 25B recessed below the upper surface of the write word line 20B is formed.

Next, as shown in FIG. 83, the insulating layer 30A is formed on the insulating layer 29 by the CVD method. PE
A via hole is formed in the insulating layer 30A by using the P method and the RIE method. A barrier metal (eg, a barrier metal) is formed on the insulating layer 30A and the inner surface of the via hole by a sputtering method.
TaN (10 nm)) 55 is formed. Subsequently, a conductive material (for example, a metal film such as tungsten) that completely fills the via hole is formed on the insulating layer 30A by the CVD method. After that, the conductive material and the barrier metal 55 are polished by the CMP method to form the via plug 21.

Here, the thickness of the insulating layer 30A (or the height of the via plug 21) is the same as that of the write word line 20B and TM.
The distance from the R element 23 is determined. Since the strength of the magnetic field decreases in inverse proportion to the distance, it is desirable to bring the TMR element as close as possible to the write word line 20B so that data can be rewritten with a small drive current. Therefore, the thickness of the insulating layer 30A is made as thin as possible.

The insulating layer 30B is formed on the insulating layer 30A by the CVD method. A wiring groove is formed in the insulating layer 30B by using the PEP method and the RIE method. A conductive material (for example, a metal film such as Ta) that completely fills the wiring groove is formed with a thickness of about 50 nm on the insulating layer 30B by the sputtering method. After that, the conductive material is polished by CMP, and the local interconnect line (lower electrode of the TMR element) 2
Form 2.

By using the sputtering method, for example, NiFe (about 5 nm) or I is formed on the local interconnect line 22.
rMn (about 12 nm), CoFe (about 3 nm), AlO
x (about 1.2 nm), CoFe (about 5 nm) and NiF
e (about 15 nm) are sequentially formed. After that, these laminated films are patterned to form the TMR element 23.

Further, by using the CVD method, the TMR element 23
After forming the insulating layer 30C covering the TMR element 23, the insulating layer 30C on the TMR element 23 is removed by, for example, the CMP method so that the insulating layer 30C covers only the side surface of the TMR element 23.

Next, as shown in FIG. 84, the insulating layer 31 is formed on the insulating layer 30C by the CVD method. PE
A wiring groove is formed in the insulating layer 31 on the TMR element 23 by using the P method and the RIE method.

The insulating layer 3 is formed by using the CVD method and the RIE method.
The insulating layer 5 different from the insulating layer 31 is formed on the side wall of the wiring groove 1.
Form 0. Thereafter, a barrier metal (for example, Ti (2) is formed on the insulation 31 and the inner surface of the wiring groove by a sputtering method.
5 nm) and TiN (25 nm) are stacked) 56. Subsequently, a conductive material (for example, AlCu (650 nm)) that completely fills the wiring groove is formed on the insulating layer 31 by the sputtering method. Then, by CMP, the conductive material and the barrier metal 5
6 is polished to form a data selection line (read / write bit line) 24.

Next, as shown in FIG. 85, only the insulating layer 50 is selectively etched by using an etching method such as the RIE method. The insulating layer 50 is left only near the lower surface of the data selection line 24. After that, using the CVD method,
A yoke material (for example, NiFe) 26 that fills the portion where the insulating layer 50 is removed is formed with a thickness of about 50 nm. The yoke material 26 is also formed on the data selection line 24 and the insulating layer 31.

Next, as shown in FIG. 86, the yoke material 26 is patterned by using the PEP method and the RIE method.
As a result, the yoke material 26 has a structure that covers the upper surface and the side surface of the data selection line 24 and is recessed above the lower surface of the data selection line 24.

Through the above steps, the magnetic random access memory according to the third embodiment (FIGS. 15 and 16) is completed.

In the manufacturing method of this example, the metal wiring 20
Although A, 20B, and 24 are formed by the damascene process, for example, the metal wiring 20 is formed by the RIE process.
It is also possible to form A, 20B and 24.

In addition, in the manufacturing method of this example, the yoke material 25
Although the barrier metal 54 is formed after forming A and 25B, instead of this, for example, the yoke materials 25A and 25B may be formed after forming the barrier metal 54.

(2) Method for Manufacturing Device Structure According to Example 6 First, as shown in FIG. 87, PEP (Photo Engraving)
Process) method, CVD (Chemical Vapor Deposition)
The element isolation insulating layer 12 having the STI structure is formed in the semiconductor substrate 11 by using a well-known method such as the CMP (Chemical Mechanical Polishing) method.

In addition, a MOS transistor as a read selection switch is formed in the element region surrounded by the element isolation insulating layer 12.

The MOS transistor is formed by the CVD method or PEP.
Method and RIE (Reactive Ion Etching) method, gate insulating layer 13 and gate electrode (read word line) 14
After the formation of the source region, the source region 16-
It can be easily formed by forming the S and drain regions 16-D. In addition, on the side wall of the gate electrode 14,
The sidewall insulating layer 15 may be formed by the CVD method and the RIE method.

Thereafter, the insulating layer 28A which completely covers the MOS transistor is formed by the CVD method. Also, CM
The surface of the insulating layer 28A is flattened by using the P method. PE
Using the P method and the RIE method, the MOS is formed in the insulating layer 28A.
Contact holes reaching the source diffusion layer 16-S and the drain diffusion layer 16-D of the transistor are formed.

A barrier metal (for example, T) is formed on the insulating layer 28A and the inner surface of the contact hole by the sputtering method.
a (15 nm) and TaN (15 nm) stack) 51 is formed. Subsequently, a conductive material (for example, a conductive polysilicon film containing impurities, a metal film, etc.) that completely fills the contact hole is formed on the insulating layer 28A. Then, the conductive material and the barrier metal 51 are polished by the CMP method to form the contact plugs 17A and 17B.

The insulating layer 28B is formed on the insulating layer 28A by the CVD method. A wiring groove is formed in the insulating layer 28B by using the PEP method and the RIE method. A barrier metal (for example, a stack of Ta and TaN) 52 is formed on the insulating layer 28B and the inner surface of the wiring groove by the sputtering method. Subsequently, a conductive material (for example, a metal film of aluminum, copper, or the like) that completely fills the wiring groove is formed on the insulating layer 28B by the sputtering method. After that, the conductive material and the barrier metal 52 are polished by CMP to form the intermediate layer 18A and the source line 18B.

Then, the insulating layer 28B is formed by using the CVD method.
An insulating layer 28C is formed thereover. By using the PEP method and the RIE method, a via hole is formed in the insulating layer 28C.
e) is formed. A barrier metal (for example, T) is formed on the insulating layer 28C and on the inner surface of the via hole by the sputtering method.
A laminated layer 53 of Ta and TaN) 53 is formed. Subsequently, a conductive material (for example, a metal film such as aluminum or copper) that completely fills the via hole is formed on the insulating layer 28C by the sputtering method.
To form. After that, the conductive material and the barrier metal 53 are polished by the CMP method to form the via plug 19.

Next, as shown in FIG. 88, the insulating layer 29 is formed on the insulating layer 28C by the CVD method. PE
A wiring groove is formed in the insulating layer 29 by using the P method and the RIE method. Using a sputtering method, a yoke material (for example, NiF) having high magnetic permeability is formed on the insulating layer 29 and in the wiring groove.
e) Form 25A and 25B with a thickness of about 20 nm.
After that, when the yoke materials 25A and 25B are etched by using the RIE method, the yoke materials 25A and 25B remain only on the side wall portion of the wiring groove.

A barrier metal (for example, a stack of Ta and TaN) 54 is formed on the insulating layer 29 and the inner surface of the wiring groove by the sputtering method. Then, using the sputtering method,
On the insulating layer 29, a conductive material (for example, a metal film such as aluminum or copper) 20 that completely fills the wiring groove is formed.
After that, the conductive material 20 and the barrier metal 5 are formed by CMP.
4 is polished, intermediate layer 20A and write word line 2
0B is formed (see FIG. 89).

Here, in this example, as shown in FIG.
After leaving the conductive materials 20A and 20B only in the wiring grooves, the yoke materials 25A and 25B are polished by etching or CMP. The yoke materials 25A and 25B are polished under the condition that the upper surfaces thereof are arranged below the upper surface of the insulating layer 29 (or the upper surfaces of the conductive materials 20A and 20B). Through these steps, the yoke material 25B recessed below the upper surface of the write word line 20B is formed.

Next, as shown in FIG. 89, the insulating layer 30A is formed on the insulating layer 29 by the CVD method. PE
A via hole is formed in the insulating layer 30A by using the P method and the RIE method. A barrier metal (eg, a barrier metal) is formed on the insulating layer 30A and the inner surface of the via hole by a sputtering method.
A Ta / TaN stack) 55 is formed. Continuous CVD
By the method, a conductive material (for example, a metal film such as tungsten) that completely fills the via hole is formed on the insulating layer 30A. After that, the conductive material and the barrier metal 55 are polished by the CMP method to form the via plug 21.

Here, the thickness of the insulating layer 30A (or the height of the via plug 21) is the same as that of the write word line 20B and TM.
The distance from the R element 23 is determined. Since the strength of the magnetic field decreases in inverse proportion to the distance, it is desirable to bring the TMR element as close as possible to the write word line 20B so that data can be rewritten with a small drive current. Therefore, the thickness of the insulating layer 30A is made as thin as possible.

The insulating layer 30B is formed on the insulating layer 30A by the CVD method. A wiring groove is formed in the insulating layer 30B by using the PEP method and the RIE method. A conductive material (for example, a metal film such as Ta) that completely fills the wiring groove is formed on the insulating layer 30B by a sputtering method. After this,
The conductive material is polished by CMP to form a local interconnect line (lower electrode of TMR element) 22.

By using the CVD method, for example, NiFe (about 5 nm), Ir is formed on the local interconnect line 22.
Mn (about 12 nm), CoFe (about 3 nm), AlOx
(About 1.2 nm), CoFe (about 5 nm) and NiFe
(About 15 nm) are sequentially formed. After that, these laminated films are patterned to form the TMR element 23.

Further, the TMR element 23 is formed by using the CVD method.
After forming the insulating layer 30C covering the TMR element 23, the insulating layer 30C on the TMR element 23 is removed by, for example, the CMP method so that the insulating layer 30C covers only the side surface of the TMR element 23.

Next, as shown in FIG. 90, the insulating layer 31 is formed on the insulating layer 30C by the CVD method. PE
A wiring groove is formed in the insulating layer 31 on the TMR element 23 by using the P method and the RIE method.

The insulating layer 3 is formed by using the CVD method and the RIE method.
The insulating layer 5 different from the insulating layer 31 is formed on the side wall of the wiring groove 1.
Form 0. After that, the insulating layer 31 is formed by the sputtering method.
A barrier metal (for example, Ti
(25 nm) and TiN (25 nm) lamination) 56 is formed. Subsequently, a conductive material (for example, AlCu (650 nm)) that completely fills the wiring groove is formed on the insulating layer 31 by the sputtering method. Then, by CMP, the conductive material and the barrier metal 5
6 is polished to form a data selection line (read / write bit line) 24.

Next, as shown in FIG. 91, only the insulating layer 50 is selectively etched by using an etching method such as RIE. The insulating layer 50 is left only near the lower surface of the data selection line 24. After that, using the CVD method,
The yoke material 2 that fills the part where the insulating layer 50 is removed
6 is formed. This yoke material 26 is used for the data selection line 24.
It is also formed on the top and the insulating layer 31.

Next, as shown in FIG. 92, the yoke material 26 is etched by the CMP method or the RIE method. As a result, the yoke material 26 on the data selection line 24 and the insulating layer 31 is removed, and the yoke material 26 is removed from the data selection line 2.
4 has a structure that covers only the side surface and is recessed above the lower surface of the data selection line 24.

Through the above steps, the magnetic random access memory according to the sixth embodiment (FIGS. 59 and 60) is completed.

In the manufacturing method of this example, the metal wiring 20
Although A, 20B, and 24 are formed by the damascene process, for example, the metal wiring 20 is formed by the RIE process.
It is also possible to form A, 20B and 24.

Further, in the manufacturing method of this example, the yoke material 25
Although the barrier metal 54 is formed after forming A and 25B, instead of this, for example, the yoke materials 25A and 25B may be formed after forming the barrier metal 54.

By the way, the yoke material 26 covering the side surface of the data selection line 24 can also be formed by the following method.

First, as shown in FIG. 93, the insulating layer 31 is formed on the insulating layer 30C by the CVD method. PE
A wiring groove is formed in the insulating layer 31 on the TMR element 23 by using the P method and the RIE method. After this, by the sputtering method,
A barrier metal (for example, a stack of Ti (25 nm) and TiN (25 nm)) 56 is formed on the insulating layer 31 and the inner surface of the wiring groove. Then, a conductive material (for example, AlCu (650n) which completely fills the wiring groove is formed on the insulating layer 31 by the sputtering method.
m)) is formed. Then, the conductive material and the barrier metal 56 are polished by CMP to form the data selection line (read / write bit line) 24.

Next, as shown in FIG. 94, only the insulating layer 31 is selectively etched by using an etching method such as RIE. The insulating layer 31 is left only near the lower surface of the data selection line 24.

Next, as shown in FIG. 95, a yoke material (for example, NiFe) 26 having a thickness of about 50 nm is formed on the insulating layer 31 and on the side surface and the upper surface of the data selection line 24 by the CVD method. To form. Then, by the RIE method,
When this yoke material 26 is etched, the data selection line 2
4, the yoke material 26 on the insulating layer 31 is removed, and the yoke material 26 has a structure that covers only the side surface of the data selection line 24 and is recessed above the lower surface of the data selection line 24.

Through the above steps, the magnetic random access memory according to the sixth embodiment (FIGS. 59 and 60) is completed.

12. In the other reference examples 1 and 2, the embodiments 1-6 and the description of the manufacturing method, one TMR element and one read selection switch (MOS transistor) constitute a memory cell, and a write word line and a data selection line (readout) are read. A magnetic random access memory having a / write bit line) has been described as an example.

However, the present invention is not of course limited to the magnetic random access memory having such a cell array structure, and, for example, as shown in Examples 7-12, includes those device structures. And is applicable to all magnetic random access memories.

For example, a magnetic random access memory having no read selection switch, a magnetic random access memory provided with a read bit line and a write bit separately, a magnetic random access memory having a plurality of bits stored in one TMR element, etc. Can also be applied to.

[0357]

As described above, according to the magnetic random access memory of the present invention, the yoke material having a high magnetic permeability is provided on a part of the surface of the write word line and the write bit line, and By recessing the yoke material on the side opposite to the TMR element side, the write word line and the T
The possibility of short-circuiting with the MR element can be reduced, and the combined magnetic field can efficiently act on the TMR element during the writing operation.

[Brief description of drawings]

FIG. 1 is a sectional view showing a reference example 1 of a magnetic random access memory according to the present invention.

FIG. 2 is a sectional view showing a reference example 1 of a magnetic random access memory according to the present invention.

FIG. 3 is a sectional view showing Reference Example 2 of the magnetic random access memory of the present invention.

FIG. 4 is a sectional view showing Reference Example 2 of the magnetic random access memory of the present invention.

FIG. 5 is a cross-sectional view showing a reference example 2 of the magnetic random access memory of the present invention.

FIG. 6 is a sectional view showing Reference Example 2 of the magnetic random access memory of the present invention.

FIG. 7 is a sectional view showing a magnetic random access memory according to a first embodiment of the present invention.

FIG. 8 is a sectional view showing a magnetic random access memory according to a first embodiment of the present invention.

FIG. 9 is a sectional view showing a magnetic random access memory according to a first embodiment of the present invention.

FIG. 10 is a sectional view showing a magnetic random access memory according to a first embodiment of the present invention.

FIG. 11 is a cross-sectional view showing a modified example of the first embodiment.

FIG. 12 is a cross-sectional view showing a modified example of the first embodiment.

FIG. 13 is a cross-sectional view showing a modified example of the first embodiment.

FIG. 14 is a sectional view showing a modified example of the first embodiment.

FIG. 15 is a sectional view showing a modification of the first embodiment.

FIG. 16 is a sectional view showing a modified example of the first embodiment.

FIG. 17 is a cross-sectional view showing a modified example of the first embodiment.

FIG. 18 is a cross-sectional view showing a modified example of the first embodiment.

FIG. 19 is a sectional view showing a magnetic random access memory according to a second embodiment of the present invention.

FIG. 20 is a sectional view showing Embodiment 2 of the magnetic random access memory of the present invention.

FIG. 21 is a sectional view showing Embodiment 2 of the magnetic random access memory of the present invention.

22 is a sectional view showing Embodiment 2 of the magnetic random access memory of the present invention. FIG.

FIG. 23 is a cross-sectional view showing a modified example of the second embodiment.

FIG. 24 is a sectional view showing a modification of the second embodiment.

FIG. 25 is a cross-sectional view showing a modified example of the second embodiment.

FIG. 26 is a sectional view showing a modified example of the second embodiment.

FIG. 27 is a cross-sectional view showing a modified example of the second embodiment.

FIG. 28 is a cross-sectional view showing a modified example of the second embodiment.

FIG. 29 is a cross-sectional view showing a modified example of the second embodiment.

FIG. 30 is a cross-sectional view showing a modified example of the second embodiment.

FIG. 31 is a sectional view showing Embodiment 3 of the magnetic random access memory of the present invention.

32 is a sectional view showing Embodiment 3 of the magnetic random access memory of the present invention. FIG.

FIG. 33 is a sectional view showing Embodiment 3 of the magnetic random access memory of the present invention.

FIG. 34 is a sectional view showing a magnetic random access memory according to a third embodiment of the present invention.

FIG. 35 is a sectional view showing Embodiment 4 of the magnetic random access memory of the present invention.

FIG. 36 is a sectional view showing a magnetic random access memory according to a fourth embodiment of the present invention.

FIG. 37 is a sectional view showing a magnetic random access memory according to a fourth embodiment of the present invention.

FIG. 38 is a sectional view showing Embodiment 4 of the magnetic random access memory of the present invention.

FIG. 39 is a sectional view showing a modified example of the fourth embodiment.

FIG. 40 is a sectional view showing a modification of the fourth embodiment.

FIG. 41 is a sectional view showing a modification of the fourth embodiment.

FIG. 42 is a sectional view showing a modification of the fourth embodiment.

FIG. 43 is a cross-sectional view showing a modified example of the fourth embodiment.

FIG. 44 is a sectional view showing a modification of the fourth embodiment.

FIG. 45 is a sectional view showing a modification of the fourth embodiment.

FIG. 46 is a sectional view showing a modification of the fourth embodiment.

FIG. 47 is a sectional view showing a magnetic random access memory according to a fifth embodiment of the present invention.

FIG. 48 is a sectional view showing a magnetic random access memory according to a fifth embodiment of the present invention.

FIG. 49 is a sectional view showing Embodiment 5 of the magnetic random access memory of the present invention.

50 is a sectional view showing Embodiment 5 of the magnetic random access memory of the present invention. FIG.

FIG. 51 is a sectional view showing a modification of the fifth embodiment.

FIG. 52 is a sectional view showing a modification of the fifth embodiment.

FIG. 53 is a sectional view showing a modification of the fifth embodiment.

FIG. 54 is a sectional view showing a modification of the fifth embodiment.

FIG. 55 is a sectional view showing a modification of the fifth embodiment.

FIG. 56 is a sectional view showing a modification of the fifth embodiment.

FIG. 57 is a sectional view showing a modification of the fifth embodiment.

FIG. 58 is a sectional view showing a modification of the fifth embodiment.

FIG. 59 is a sectional view showing Embodiment 6 of the magnetic random access memory of the present invention.

FIG. 60 is a sectional view showing Embodiment 6 of the magnetic random access memory of the present invention.

FIG. 61 is a sectional view showing a magnetic random access memory according to a sixth embodiment of the present invention.

FIG. 62 is a sectional view showing Embodiment 6 of the magnetic random access memory of the present invention.

63 is a sectional view showing Embodiment 7 of the magnetic random access memory of the present invention. FIG.

64 is a sectional view showing Embodiment 7 of the magnetic random access memory of the present invention. FIG.

FIG. 65 is a sectional view showing Embodiment 8 of the magnetic random access memory of the present invention.

FIG. 66 is a sectional view showing an eighth embodiment of the magnetic random access memory of the present invention.

FIG. 67 is a sectional view showing Embodiment 9 of the magnetic random access memory of the present invention.

68 is a sectional view showing Embodiment 9 of the magnetic random access memory of the present invention. FIG.

FIG. 69 is a sectional view showing Embodiment 9 of the magnetic random access memory of the present invention.

70 is a sectional view showing Embodiment 9 of the magnetic random access memory of the present invention. FIG.

71 is a sectional view showing Embodiment 10 of the magnetic random access memory of the present invention. FIG.

72 is a sectional view showing Embodiment 10 of the magnetic random access memory of the present invention. FIG.

73 is a sectional view showing Embodiment 10 of the magnetic random access memory of the present invention. FIG.

FIG. 74 is a sectional view showing Embodiment 10 of the magnetic random access memory of the present invention.

FIG. 75 is a sectional view showing Embodiment 11 of the magnetic random access memory of the present invention.

76 is a sectional view showing Embodiment 11 of the magnetic random access memory of the present invention. FIG.

77 is a sectional view showing Embodiment 12 of the magnetic random access memory of the present invention. FIG.

FIG. 78 is a sectional view showing Embodiment 12 of the magnetic random access memory of the present invention.

FIG. 79 is a circuit diagram showing a structural example of a cell array of the magnetic random access memory of the present invention.

80 is a diagram showing operating waveforms of the cell array of FIG. 79. FIG.

81 is a cross-sectional view showing a step in the device structure manufacturing method of Example 3. FIG.

82 is a cross-sectional view showing a step in the device structure manufacturing method of Example 3. FIG.

FIG. 83 is a cross-sectional view showing a step in the device structure manufacturing method of the third example.

84 is a cross-sectional view showing a step in the method of manufacturing the device structure according to Example 3. FIG.

85 is a cross-sectional view showing a step in the device structure manufacturing method of Example 3. FIG.

FIG. 86 is a cross-sectional view showing a step in the device structure manufacturing method of Example 3.

FIG. 87 is a cross-sectional view showing a step in the device structure manufacturing method of Example 6.

88 is a cross-sectional view showing a step in the device structure manufacturing method of Example 6. FIG.

FIG. 89 is a cross-sectional view showing a step in the device structure manufacturing method of Example 6.

FIG. 90 is a cross-sectional view showing a step in the device structure manufacturing method of Example 6.

FIG. 91 is a cross-sectional view showing a step in the device structure manufacturing method of Example 6.

FIG. 92 is a cross-sectional view showing a step in the device structure manufacturing method of Example 6.

FIG. 93 is a cross-sectional view showing a step in the device structure manufacturing method of Example 6.

FIG. 94 is a cross-sectional view showing a step in the device structure manufacturing method of Example 6.

FIG. 95 is a cross-sectional view showing a step in the device structure manufacturing method of Example 6.

FIG. 96 is a view showing a structural example of a TMR element.

FIG. 97 is a view showing two states of the TMR element.

FIG. 98 is a diagram showing a write operation principle of the magnetic random access memory.

FIG. 99 is a diagram showing a TMR curve.

FIG. 100 shows an asteroid curve.

[Explanation of symbols]

11: semiconductor substrate, 12: element isolation insulating layer, 13: gate insulating layer, 14: gate electrode (read word line), 15: side wall insulating layer, 16-S: source region, 16-D: drain region, 17A, 17B: contact plug, 18A, 20A: intermediate layer, 18B: source line (read word line), 19: 21 via plug, 20B: write word line, 22: lower electrode, 23: TMR element, 24: data selection line (reading/
Write bit line), 25, 25A, 25B, 26, 27: Yoke material, 28A to 28C, 29, 30A to 30C, 31, 50
: Insulating layer, 40, 41, 42: current drive power source, 43: read power source, 44: detection circuit

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] April 22, 2003 (2003.4.2)
2)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshiaki Saito             1st Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa             Inside the Toshiba Research and Development Center (72) Inventor Hiroaki Yasuda             1st Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa             Inside the Toshiba Research and Development Center (72) Inventor Tomomasa Ueda             1st Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa             Inside the Toshiba Research and Development Center (72) Inventor Minoru Amano             1st Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa             Inside the Toshiba Research and Development Center (72) Inventor Shigeki Takahashi             1st Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa             Inside the Toshiba Research and Development Center (72) Inventor Tatsuya Kishi             1st Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa             Inside the Toshiba Research and Development Center F-term (reference) 5F083 FZ10 JA02 JA32 JA36 JA37                       JA39 JA40 KA01 KA05 KA18                       LA03 LA04 LA05 MA05 MA06                       MA16 MA19 NA01 PR06 PR39                       PR40

Claims (46)

[Claims] 1. A memory cell formed on a semiconductor substrate for storing data by utilizing a magnetoresistive effect, a first write line arranged immediately below the memory cell and extending in a first direction, and the memory. The first cell is arranged directly above the cell.
A second write line extending in a second direction that intersects the first direction, and a first yoke member that covers a side surface of the first write line and is recessed below an upper surface of the first write line. And magnetic random access memory. 2. The magnetic random access memory according to claim 1, wherein the first yoke material covers only a side surface of the first write line. 3. The magnetic random access memory according to claim 1, wherein the first yoke material covers a lower surface of the first write line. 4. The magnetic random access memory according to claim 1, further comprising a second yoke material that covers a part of the surface of the second write line. 5. The magnetic random access memory according to claim 4, wherein the second yoke material covers an upper surface and a side surface of the second write line. 6. The magnetic random access memory according to claim 4, wherein the second yoke material covers only an upper surface of the second write line. 7. The magnetic random access memory according to claim 4, wherein the second yoke material covers only a side surface of the second write line. 8. One of the first and second write lines
2. The magnetic random access memory according to claim 1, wherein the magnetic random access memory is electrically connected to the memory cell and also functions as a read bit line. 9. A memory cell formed on a semiconductor substrate for storing data by utilizing a magnetoresistive effect, a first write line arranged immediately below the memory cell and extending in a first direction, and the memory. The first cell is arranged directly above the cell.
A second write line extending in a second direction intersecting the direction, and a first yoke member that covers a side surface of the second write line and is recessed above a lower surface of the second write line. And magnetic random access memory. 10. The first yoke material covers only a side surface of the second write line.
The magnetic random access memory described. 11. The magnetic random access memory according to claim 9, wherein the first yoke material covers an upper surface of the second write line. 12. The magnetic random access memory according to claim 9, further comprising a second yoke material that covers a part of the surface of the first write line. 13. The magnetic random access memory according to claim 12, wherein the second yoke material covers a lower surface and a side surface of the first write line. 14. The second yoke material covers only the lower surface of the first write line.
2. The magnetic random access memory according to 2. 15. The second yoke material covers only a side surface of the first write line.
2. The magnetic random access memory according to 2. 16. The magnetic random access device according to claim 9, wherein one of the first and second write lines is electrically connected to the memory cell and also functions as a read bit line. memory. 17. The first and second memory cells, which are stacked on a semiconductor substrate and store data by utilizing a magnetoresistive effect, are arranged between the first and second memory cells and have a first direction. And a first yoke material that covers only the side surface of the first write line and that is recessed below the upper surface of the first write line and recessed above the lower surface of the first write line. And a magnetic random access memory. 18. The first memory cell is disposed above the second memory cell.
7. The magnetic random access memory according to 7. 19. A second write line, which is arranged directly below the first memory cell and extends in a second direction intersecting the first direction, and a second write line which is arranged directly above the second memory cell and is arranged in the second direction. 19. The magnetic random access memory according to claim 18, further comprising a third write line extending. 20. The second yoke material, which covers only the side surface of the second write line and is recessed below the upper surface of the second write line, and the side surface of the third write line, and the third yoke material. 20. The magnetic random access memory according to claim 19, further comprising a third yoke member recessed above the lower surface of the write line. 21. The magnetic random access memory according to claim 17, wherein the first write line is separated from the first and second memory cells. 22. The magnetic random access memory according to claim 17, wherein the first write line is in contact with the first and second memory cells. 23. A plurality of memory cells, which are arranged side by side in a direction parallel to the surface of the semiconductor substrate on the semiconductor substrate to store data by utilizing a magnetoresistive effect, and shared by the plurality of memory cells. , A first extending in a first direction
A write line, a plurality of second write lines that are individually provided in the plurality of memory cells and extend in a second direction intersecting the first direction, and cover only side surfaces of the first write line, and the first write A first yoke member that is recessed on the side opposite to the plurality of memory cell sides with respect to the surface of the line on the side of the plurality of memory cells, and covers only side surfaces of the plurality of second write lines; 2. A magnetic random access memory, comprising: a second yoke material that is recessed on the side opposite to the plurality of memory cells from the surface on the side of the plurality of memory cells. 24. The magnetic random access memory according to claim 23, wherein the first write line is arranged immediately above the plurality of memory cells and is in contact with one end of the plurality of memory cells. 25. The magnetic random access memory according to claim 24, wherein the other ends of the plurality of memory cells are commonly connected. 26. The magnetic random access memory according to claim 23, wherein the plurality of second write lines are arranged immediately below the plurality of memory cells and are separated from the plurality of memory cells. 27. The magnetic random access memory according to claim 23, wherein the first write line is arranged immediately above the plurality of memory cells and is separated from the plurality of memory cells. 28. The magnetic random access device according to claim 23, wherein the plurality of second write lines are arranged immediately below the plurality of memory cells and are in contact with one ends of the plurality of memory cells. memory. 29. The magnetic random access memory according to claim 28, wherein the other ends of the plurality of memory cells are commonly connected. 30. A step of forming an insulating layer on a semiconductor substrate, a step of forming a wiring groove in the insulating layer, a step of forming a yoke material on a bottom portion and a side wall portion of the wiring groove, and the wiring groove. Filling a conductive material therein to form a write line; etching a part of the yoke material to lower the yoke material below an upper surface of the write line; and TMR directly above the write line. A method of manufacturing a magnetic random access memory, comprising the step of forming an element. 31. The yoke material is formed on the insulating layer and on the bottom and side walls of the wiring groove by a CVD method, and then left on the bottom and side walls of the wiring groove by a CMP method. 31. The method for manufacturing a magnetic random access memory according to claim 30, wherein 32. The conductive material is formed on the insulating layer and in the wiring groove by a CVD method, and is then left only in the wiring groove by a CMP method. A method of manufacturing a magnetic random access memory as described. 33. A step of forming an insulating layer on a semiconductor substrate, a step of forming a wiring groove in the insulating layer, a step of forming a yoke material only on a side wall portion of the wiring groove, and A step of forming a write line by filling a conductive material therewith, and a step of etching a part of the yoke material so that the yoke material is recessed below the upper surface of the write line.
And a step of forming a TMR element directly above the write line, the method of manufacturing a magnetic random access memory. 34. The yoke material is formed on the insulating layer and on the bottom portion and side wall portion of the wiring groove by a CVD method, and then left only on the side wall portion of the wiring groove by an RIE method. 34. The method of manufacturing a magnetic random access memory according to claim 33, wherein: 35. The conductive material is formed on the insulating layer and in the wiring groove by a CVD method, and then left only in the wiring groove by a CMP method. A method of manufacturing a magnetic random access memory as described. 36. A step of forming a TMR element on a semiconductor substrate, a step of forming a first insulating layer on the TMR element, and a step of forming a wiring groove in the first insulating layer on the TMR element. A step of forming a second insulating layer only on the side wall of the wiring groove, a step of filling the wiring groove with a conductive material to form a write line, and a step of etching a part of the second insulating layer. The method further comprises the step of leaving the second insulating layer only near the lower surface of the write line, and the step of forming a yoke material on the sidewall portion of the wiring groove from which the second insulating layer has been removed. Manufacturing method of magnetic random access memory. 37. The method of manufacturing a magnetic random access memory according to claim 36, wherein the yoke material is formed on a side wall portion of the wiring groove and at the same time formed on an upper surface of the write line. . 38. The yoke material is formed on the side wall of the wiring groove, the first insulating layer and the write line by a CVD method, and then left on the side wall of the wiring groove by a CMP method. 37. The method of manufacturing a magnetic random access memory according to claim 36, wherein: 39. The yoke material is formed on the side wall of the wiring groove, the first insulating layer and the write line by a CVD method, and then left on the side wall of the wiring groove by an RIE method. 37. The method of manufacturing a magnetic random access memory according to claim 36, wherein: 40. The yoke material is formed on the side wall of the wiring groove, the first insulating layer and the write line by a CVD method, and then the side wall of the wiring groove and the write is formed by an RIE method. 37. The method of manufacturing a magnetic random access memory according to claim 36, wherein the magnetic random access memory is left on the line. 41. The etching amount of the second insulating layer is determined on the condition that the lower surface of the yoke material is disposed between the upper surface and the lower surface of the write line. A method of manufacturing a magnetic random access memory as described. 42. The conductive material is formed on the insulating layer and in the wiring groove by a CVD method, and then left only in the wiring groove by a CMP method. A method of manufacturing a magnetic random access memory as described. 43. A step of forming a TMR element on a semiconductor substrate, a step of forming an insulating layer on the TMR element, a step of forming a wiring groove in the insulating layer on the TMR element, and the wiring. Forming a write line by filling a conductive material in the groove; etching a part of the insulating layer to leave the insulating layer only near the lower surface of the write line; and removing the insulating layer. And a step of forming a yoke material on the side surface of the write line exposed by the step of manufacturing the magnetic random access memory. 44. The yoke material is formed on the insulating layer and on the upper surface and the side surface of the write line by the CVD method, and is then left only on the side surface of the write line by the RIE method. The method for manufacturing a magnetic random access memory according to claim 43. 45. The etching amount of the insulating layer is determined on the condition that the lower surface of the yoke material is arranged between the upper surface and the lower surface of the write line. Manufacturing method of magnetic random access memory. 46. The conductive material is formed on the insulating layer and in the wiring groove by a CVD method, and then left only in the wiring groove by a CMP method. A method of manufacturing a magnetic random access memory as described.