Magnetoresistive memory storage element and magnetic random access memory device

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention presents a magnetoresistive memory element having a magnetic structure (hereinafter referred to as a TMR (Tunneling Magneto Resistive) element) and a magnetic random access memory device using the same (hereinafter abbreviated as MRAM = Magnetic Random Access Memory). It is about.

【0002】

[Conventional technology]

The MRAM is a memory device that utilizes the fact that the resistance value changes depending on the spin direction of the magnetic material when a current is passed through the magnetic material structure. A TMR element is used as an element that performs memory operation. One bit of the magnetic memory consists of this TMR element and one MOS transistor. FIG. 10 shows the structure of a conventional MRAM. In the figure, 100 is a TMR element, which has a sandwich structure in which a thin insulating layer 102 is sandwiched between the first magnetic material 101 and the second magnetic material 103. Reference numeral 150 denotes a semiconductor substrate (hereinafter referred to as a substrate), and an access transistor which is a MOS transistor is formed on the substrate 150, and 155 is a source / drain region thereof. 160 is a read word line that serves as a gate electrode of an access transistor, and 165 is a write word line. 170 is an electrode portion connecting one of the source / drain regions 155 and the first magnetic material 101, 175 is a laminated interlayer insulating film, and 180 is a bit wire. The first magnetic material 101 is a spin-free layer in which the spin direction is not fixed and is variable, and the second magnetic material 103 is a spin-fixed layer in which the spin is fixed in a predetermined direction. Since the structure has a long rectangle in the direction of the bit wire 180, the spin direction of the first magnetic body 101 is easily oriented in the length direction (bit wire direction) of the bit wire 180. The spin direction of the second magnetic body 103 is fixed in the bit line direction.

【0003】

In writing to the TMR element 100 in such a conventional MRAM, as shown in FIG. 11, a current is passed through the bit wire 180 and the write word wire 165, and the generated magnetic field is a first magnetic material having a spin free layer. This is done by determining the spin direction of 101. That is, data of "1" or "0" is written depending on the direction in which the direction is the same as or opposite to the spin direction of the second magnetic material 103. This writing requires a magnetic field of a certain amount or more, and is characterized in that it is performed only in the cell where the bit line 180 and the writing word line 165 intersect. On the other hand, for reading from the TMR element 100, a voltage is applied between the first magnetic body 101 and the second magnetic body 103, and a voltage is applied to the read word line 160 to turn on the access transistor for access. This is done by reading the current flowing into the transistor. When the spin direction of the first magnetic body 101 and the spin direction of the second magnetic body 103 are the same, the current flows well, but when the spin direction of the second magnetic body 103 is opposite, the current does not flow so much. The resistance value between 101 and the second magnetic material 103 is changed, the access transistor is turned on, and the magnitude of the current flowing from the bit wire 180 into the access transistor is determined.

【0004】

[Problems to be Solved by the Invention]

In the conventional magnetic random access memory device as described above, the write word line and the read word line are required separately, and the word line and the bit line are thinned because they form a TMR element in the intersecting region. Was difficult. Further, since the TMR element has a structure in which a flat plate-shaped magnetic material is laminated via an insulating layer, it is difficult to reduce the occupied area, and when it is miniaturized, the magnetic field strength required for spin inversion increases. Therefore, a stronger writing current is required, and the structure is not suitable for promoting miniaturization and integration.

【0005】

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a structure of a TMR element which can reduce a writing current and is suitable for miniaturization and integration. Another object of the present invention is to obtain a magnetic random access memory device provided with such a TMR element and promoted miniaturization and integration.

【0006】

[Means for solving problems]

The magnetic resistance storage element according to claim 1 according to the present invention has a cylindrical first magnetic material having a variable magnetization direction and one end open, and an insulating layer inside the cylinder of the first magnetic material. It is provided with a columnar second magnetic material whose magnetization direction is fixed in one circumferential direction, and a rotating magnetic field is generated by passing a tunnel current between the first and second magnetic materials. The magnetizing direction of the first magnetic material is set to one or the other circumferential direction, and the change in magnetic resistance due to the magnetizing direction of the first magnetic material with respect to the magnetizing direction of the second magnetic material is used as a binary signal. Is.

【0007】

The magnetic resistance storage element according to claim 2 according to the present invention has a variable magnetization direction, and is integrally composed of a columnar pattern and a cylindrical pattern arranged around the columnar pattern with one end open. 1 magnetic material and a cylinder formed in the cylindrical pattern of the first magnetic material around the columnar pattern via an insulating layer, the magnetization direction is fixed in one circumferential direction, and one end is open. It is provided with a second magnetic material in the shape of a magnet, and a rotating magnetic field is generated by passing a tunnel current between the first and second magnetic materials to change the magnetization direction of the first magnetic material in one or the other circumferential direction. Is set to, and the change in magnetic resistance due to the magnetization direction of the first magnetic material with respect to the magnetization direction of the second magnetic material is used as a binary signal.

【0008】

The magnetoresistive memory device according to claim 3 according to the present invention has a surface area increased by roughening the surfaces of the first magnetic material and the second magnetic material facing each other in claim 1 or 2. is there.

【0009】

In any one of claims 1 to 3, the reluctance storage element according to claim 4 according to the present invention has an insulating layer formed on the inner bottom of the cylinder of the magnetic material more than an insulating layer formed on the inner side wall of the cylinder. The film thickness is thick.

【0010】

The magnetic resistance storage element according to claim 5 according to the present invention is formed of a cylindrical magnetic material having a variable magnetization direction and open ends, and an insulating layer so as to penetrate the inside of the cylinder of the magnetic material. A columnar wiring layer is provided, and a rotating magnetic field is generated by passing a current through the wiring layer to set the magnetization direction of the magnetic material in one or the other circumferential direction, and the magnitude of the current flowing through the wiring layer is large or small. Is used to read out the magnetization direction of the magnetic material.

【0011】

The magnetic random access memory device according to claim 6 according to the present invention has a magnetic resistance storage element according to any one of claims 1 to 4, an access transistor, and an upper layer of the magnetic resistance storage element on a semiconductor substrate. One magnetic material of the reluctance storage element is connected to the common electrode, and the other is connected to the access transistor.

【0012】

The magnetic random access memory device according to claim 7 according to the present invention comprises a magnetic resistance storage element according to any one of claims 1 to 4, a diode forming a PN junction, and the magnetic resistance on a semiconductor substrate. It is provided with a common electrode formed on the upper layer of the storage element, and one magnetic material of the reluctance storage element is connected to the common electrode and the other is connected to the diode.

【0013】

The magnetic random access memory device according to claim 8 according to the present invention is a common electrode formed on a semiconductor substrate on a layer of the magnetoresistive storage element according to claim 5, an access transistor, and the magnetic resistance storage element. The columnar wiring layer of the magnetoresistive storage element is arranged in the vertical direction to form a wiring for connecting the common electrode and the access transistor.

【0014】

The magnetic random access memory device according to claim 9 according to the present invention is formed on a semiconductor substrate on a layer of the magnetic resistance storage element according to claim 5, a diode forming a PN junction, and the magnetic resistance storage element. The columnar wiring layer of the magnetoresistive memory element is arranged in the vertical direction to provide wiring for connecting the common electrode and the diode.

【0015】

The magnetic random access memory device according to claim 10 according to the present invention is the first conductive type well region formed on the semiconductor substrate and the magnetoresistive storage element formed in the well region according to claim 7 or 9. The diode is composed of the connected second conductive type diffusion layer.

【0016】

The magnetic random access memory device according to claim 11 according to the present invention uses the SOI substrate as the semiconductor substrate in claim 7 or 9, and the first and second conductive type diffusions formed on the SOI substrate are adjacent to each other. The layers make up the diode.

【0017】

The magnetic random access memory device according to claim 12 according to the present invention has the wiring layer formed on the semiconductor substrate and the magnetoresistive memory element connected via a connection hole in claim 7 or 9, and the inside of the connection hole. A diode is configured in the vertical direction.

【0018】

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1. Hereinafter, the TMR element and the MRAM according to the first embodiment of the present invention will be described. FIG. 1 shows a structure of a TMR element and an MRAM using the TMR element according to the first embodiment of the present invention, FIG. 1 (a) is a cross-sectional view showing the structure of the TMR element, and FIG. 1 (b) is FIG. 1 ( A) is a cross-sectional view taken along the line AA, and FIG. 1 (c) is a cross-sectional view showing the structure of the MRAM. The cross section shown in FIG. 1B is not limited to a square, but may be a rectangle, a circle, an ellipse, or the like. As shown in FIG. 1 (a), the spin free layer 1 as a first magnetic material whose spin direction is variable without being fixed is formed, for example, in a cylindrical shape with an open upper portion, and the spin free layer 1 is formed. A spin fixing layer 3 as a columnar second magnetic material is formed in the cylinder of the above via a thin insulating layer 2, and the TMR element 4 is formed. Note that 5 and 6 are electrode portions connected to the spin fixed layer 3 and the spin free layer 1, respectively.

【0019】

In the TMR element 4 configured as described above, the spin fixing layer 3 is subjected to measures such as applying a strong magnetic field in advance, and the spin direction is set to the circumferential direction of the columnar magnetic material as shown in FIG. 1 (b). Fix it to one side (arrow X). Then, by passing a relatively large tunnel current of, for example, several mA or more from the spin free layer 1 to the spin fixed layer 3 or from the spin fixed layer 3 to the spin free layer 1 through the insulating layer 2, the spin fixed layer 3 and the spin A rotating magnetic field is generated around the free layer 1, and by setting a spin in the circumferential direction (arrow Ya or arrow Yb) of the cylinder of the spin free layer 1, writing to the TMR element 4 is performed. The rotational direction in the circumferential direction is determined by whether a current flows from the spin free layer 1 to the spin fixed layer 3 or from the spin fixed layer 3 to the spin free layer 1. That is, data of "1" or "0" is written depending on whether the spin direction of the spin free layer 1 (arrow Ya or arrow Yb) is the same as or opposite to the spin direction of the spin fixed layer 3 (arrow X). On the other hand, reading from the TMR element 4 is performed by measuring the resistance value from the spin free layer 1 to the spin fixed layer 3 in a small current region where rewriting does not occur. That is, when the spin direction of the spin free layer 1 (arrow Ya or arrow Yb) is the same as the spin direction of the spin fixed layer 3 (arrow X), the current flows well, but when it is in the opposite direction, the current does not flow much. Using the feature, the spin direction of the spin free layer 1, which is the written information, is detected.

【0020】

Next, the structure of the MRAM using such a TMR element 4 will be described below. As shown in FIG. 1 (c), for example, on a P-type semiconductor substrate 7 (hereinafter referred to as substrate 7), an access transistor 10 composed of a source / drain region 8 and a word line 9 and a spin free layer 1 are insulated. A memory cell is composed of a TMR element 4 composed of a layer 2 and a spin fixing layer 3. Further, the word line 9 and the bit line 11 are formed in a fine linear pattern according to the cell size, and the spin free layer 1 of the TMR element 4 is connected to one of the source / drain regions 8 via the connection hole 6a. A bit wire 11 is connected to the other side of the source / drain region 8 via a connection hole 12. Further, 5a is a common electrode of a flat plate to which the spin fixing layer 3 of the TMR element 4 is connected, and is arranged on the upper layer of the TMR element 4 so as to cover the entire chip or a cell array blocked in several blocks. .. Reference numeral 13 denotes a laminated interlayer insulating film.

【0021】

Next, the operation of MRAM will be described. The potential of the common electrode 5a is set to half the value of the normal power supply voltage, and the potential of the bit wire 11 is set to the ground potential or the power supply potential. Here, when a voltage is applied to the word line 9 to turn on the access transistor 10, a current path of the common electrode 5a-TMR element 4-access transistor 10-bit line 11 is created, and the direction of the current is determined by the potential of the bit line 11. It is determined. Due to this current, a rotating magnetic field is generated around the TMR element 4, the spin directions in the cylindrical spin free layer 1 are aligned, and the spin direction is set in one of the circumferential directions (arrow Ya or arrow Yb). This completes the writing operation. Next, the read operation will be described. In reading, the potential of the bit line 11 is set to a voltage slightly higher or slightly lower than half the power supply voltage, and a voltage is applied to the word line 9 to turn on the access transistor 10, and the potential is half the power supply voltage. From the common electrode 5a set in, the magnitude of the current flowing in the current path of the TMR element 4-access transistor 10-bit wire 11 is determined. The current flowing at this time is a small current that does not cause rewriting, thereby detecting the spin direction of the spin free layer 1 of the TMR element 4.

【0022】

In the above read operation, the potential of the bit wire 11 is set to a voltage slightly higher or slightly lower than half of the power supply voltage, but the potential of the bit wire 11 is set to the ground potential or the power supply voltage level. It is also possible to turn on the access transistor 10 while keeping the potential of the word line 9 lower than usual, and use the channel resistance to adjust the current region so that rewriting does not occur.

【0023】

In this embodiment, the TMR element 4 is composed of a cylindrical spin free layer 1 and a columnar spin fixing layer 3 formed in the cylinder via a thin insulating layer 2, and the spin free layer 1 and spin are formed. A relatively large tunnel current is passed between the fixed layers 3 to generate a rotating magnetic field to set the spin direction of the spin free layer 1. Conventionally, since the TMR element has a structure in which a flat plate-shaped magnetic material is laminated via an insulating layer, the magnetic field generated at the time of writing cannot be effectively used. Therefore, the generated rotating magnetic field can be efficiently used, and the spin direction set in the spin free layer 1 is also the circumferential direction of the cylinder, so that the spins can be easily aligned. Therefore, the current required for writing can be reduced, and the writing operation is completed with a small writing current. Further, since the cylindrical TMR element 4 is arranged in the vertical direction, the occupied area can be reduced, and the TMR element 4 having a structure suitable for miniaturization and integration can be obtained. Further, in the MRAM using such a TMR element 4, the occupied area of the TMR element 4 is small, the word line 9 and the bit line 11 can be formed in a fine linear pattern, and the word line 9 is one. Since only one memory cell is required, miniaturization and integration can be significantly promoted.

【0024】

In this embodiment, the cylindrical TMR element 4 is arranged with the spin fixing layer 3 on the upper side to form an MRAM, but the cylindrical spin free layer 1 is arranged on the upper side with the lower part open to spin. The fixed layer 3 may be arranged on the lower side.

【0025】

Embodiment 2. Next, the TMR element according to Embodiment 2 of the present invention will be described. FIG. 2 is a cross-sectional view showing the structure of the TMR element 4 according to the second embodiment of the present invention. As shown in FIG. 2, the inner surface of the cylinder of the spin free layer 1 of the TMR element 4 shown in FIG. 1 is roughened by providing irregularities or the like, and similarly, the surface of the facing spin fixing layer 3 is also roughened. .. As a result, the surface areas of the spin free layer 1 and the spin fixed layer 3 facing each other can be increased, the resistance value of the TMR element 4 per unit area can be reduced, and the current at the time of reading can be increased. Therefore, the influence of noise can be reduced at the time of reading, and the reliability of measurement is improved.

【0026】

Embodiment 3. Next, the TMR element according to Embodiment 3 of the present invention will be described. FIG. 3 is a cross-sectional view showing the structure of the TMR element 4 according to the third embodiment of the present invention. As shown in FIG. 3, in the insulating layer 2 arranged in the cylinder, the thickness of the insulating layer 2a formed on the inner bottom of the cylinder is made larger than that of the other portion, that is, the insulating layer 2b formed on the inner side wall of the cylinder. Make it thicker. Therefore, it is possible to prevent the tunnel current from being concentrated on the inner bottom of the cylinder and making it difficult to obtain spin information at the time of reading. This embodiment is applied when the resistance value of the cylinder itself of the spin free layer 1 is high, suppresses the concentrated flow of the tunnel current in the direction of passing through the bottom of the cylinder, and the current passing through the inner side wall of the cylinder. That is, the current flowing through the cylinder itself of the spin free layer 1 is increased, and the spin direction of the spin free layer 1 is detected with high reliability.

【0027】

Embodiment 4. In the MRAM shown in the first embodiment, the access transistor 10 is formed, but a junction may be formed on the substrate 7 instead of the access transistor 10. FIG. 4 is a cross-sectional view showing the structure of the MRAM according to the fourth embodiment. As shown in the figure, P is formed in the N well 14 as a well region formed on the P-type substrate 7.⁺Forming the diffusion layer 15, this P⁺The diffusion layer 15 and the spin free layer 1 are connected via the connection hole 6a. Further, 5b is a linear pattern arranged on the upper layer of the TMR element 4, a bit wire as a common electrode to which the spin fixing layer 3 is connected, and 17 is an electrode formed in the N well 14 through the connection hole 18. It is a wiring layer. In addition, P⁺The PN junction between the diffusion layer 15 and the N well 14 acts as a diode 16. In this case, it is assumed that the N well 14 is formed so as to extend in the direction intersecting the bit line 5b, and P⁺The diffusion layer 15 is formed corresponding to each TMR element 4, and the electrode wiring layer 17 is connected to the N well 14 at one end of the memory array.

【0028】

Next, the operation will be described. To read to a specific memory cell, a small potential is applied between the bit line 5b and the N well 14 that intersect the cell, and the current is large or small in a small current region where rewriting does not occur. The resistance value is measured by In writing, when a current is passed from the bit wire 5b to the substrate 7, a larger current than that at the time of reading is used, and the current is performed in the same manner as at the time of reading. When passing current in the opposite direction, N well 14 and P⁺The avalanche breakdown is caused to exceed the joint pressure resistance between the diffusion layer 15 and the diffusion layer 15.

【0029】

In this embodiment, by eliminating the access transistor 10, the area required on the substrate 7 can be reduced, and the cell area can be further reduced.

【0030】

As shown in FIG. 5, when the SOI substrate 7a in which the silicon thin film is formed on the insulating layer is used as the semiconductor substrate, the well region is not required, and the P-type diffusion layer 15 and the N-type diffusion layer 19 are formed. The diode 16a can be formed adjacently. In this case, the diffusion layers 15 and 19 are formed corresponding to the TMR elements 4, the electrode wiring layer 17a is formed so as to extend in the direction intersecting the bit wire 5b, and the connection hole 18 is formed in the N-type diffusion layer 19. Connected via. Since the SOI substrate 7a is used in such an MRAM, it is easy to manufacture, further miniaturization and integration can be promoted, and the concentrations of the P-type diffusion layer 15 and the N-type diffusion layer 19 are adjusted. Therefore, it can be set so that avalanche breakdown is likely to occur, and the current at the time of writing can be easily reduced.

【0031】

Further, as shown in FIG. 6, a wiring layer 17b is formed on the insulating film 20 on the substrate 7 by extending in a direction intersecting with the bit wire 5b, and the spin free layer 1 of the TMR element 4 is formed through the connection hole 6b. By connecting to the wiring layer 17b and embedding, for example, N-type doped polysilicon 22 and P-type doped polysilicon 21 in the connection hole 6b, a PN junction is formed in the connection hole 6b. It may be formed to form a diode 16b. Further, when the diode 16b is formed in the connection hole 6b in this way, it may be formed on the SOI substrate 7a as shown in FIG. 7. In this case, the wiring layer 17c is formed on the SOI substrate 7a. It consists of layers.

【0032】

Embodiment 5. Next, the TMR element according to Embodiment 5 of the present invention will be described. FIG. 8 is a cross-sectional view showing the structure of the TMR element 4a according to the fifth embodiment of the present invention. In this embodiment, as shown in the figure, the TMR element 4a is configured by double-cylinders, and the columnar pattern and the cylindrical pattern around it are connected at the bottom to form a spin free layer 1a. Then, in the cylindrical pattern of the spin free layer 1a, a cylindrical spin fixing layer 3a is formed around the columnar pattern via the insulating layer 2. In the TMR element 4a configured as described above, the spin fixing layer 3a fixes the spin direction to one of the circumferential directions of the cylinder. Then, a rotating magnetic field is generated by passing a tunnel current from the spin free layer 1a to the spin fixed layer 3a or from the spin fixed layer 3a to the spin free layer 1a, thereby causing one or the other circumference of the spin free layer 1a. By setting the spin in the direction, writing to the TMR element 4a is performed. Further, reading from the TMR element 4a is performed by measuring the resistance value from the spin free layer 1a to the spin fixed layer 3a in a small current region where rewriting does not occur.

【0033】

In this embodiment, since the surface areas of the spin free layer 1a and the spin fixed layer 3a facing each other increase, the resistance value of the TMR element 4a per unit area can be reduced and the current at the time of reading can be increased. it can. Therefore, the influence of noise can be reduced at the time of reading, and the reliability of measurement is improved. In this embodiment, the TMR element 4a is configured by making the cylinder double, but a cylindrical structure having three or more layers is also possible.

【0034】

Embodiment 6. Next, the TMR element and MRAM according to Embodiment 6 of the present invention will be described. FIG. 9 shows the structure of the TMR element and the MRAM using the TMR element according to the sixth embodiment of the present invention, FIG. 9 (a) is a cross-sectional view showing the structure of the TMR element, and FIG. 9 (b) is FIG. 9 ( A) is a cross-sectional view taken along the line BB, and FIG. 9 (c) is a cross-sectional view showing the structure of the MRAM. The cross section shown in FIG. 9B is not limited to a square, but may be a rectangle, a circle, an ellipse, or the like. As shown in FIG. 9A, the spin free layer 23 as a magnetic material whose spin direction is variable without being fixed is formed in a cylindrical shape with both ends open, and the inside of the cylinder of the spin free layer 23 is formed. A columnar wiring layer 25 is formed via the insulating layer 24 so as to penetrate the TMR element 26. Note that 5 and 6 are electrode portions connected to the wiring layer 25 and the spin free layer 23, respectively.

【0035】

In the TMR element 26 configured as described above, by passing an electric current through the columnar wiring layer 25, as shown in FIG. 9B, a rotating magnetic field is generated around the wiring layer 25, whereby spin is free. Writing to the TMR element 26 is performed by setting the spin in the circumferential direction (arrow Ya or arrow Yb) of the cylinder of the layer 23. The rotational direction in the circumferential direction is determined by the direction of the current flowing through the wiring layer 25. On the other hand, when reading from the TMR element 26, a current is passed through the wiring layer 25 to measure the resistance value in the same manner as when writing, but when the current is passed in the direction in which the spin direction is reversed, the reading is destructive and energy is consumed. , The linear resistance of the magnetic material itself of the spin free layer 23 increases, and the resistance value increases. Utilizing this feature, the spin direction of the spin free layer 23, which is the written information, is detected. When reading is performed by passing a current in the direction in which the spin direction is reversed, since the spin direction has changed when the reading is completed, writing is performed again.

【0036】

Next, a case where the structure of the MRAM using such a TMR element 26 is provided with the access transistor 10 will be described as in the first embodiment. As shown in FIG. 9 (c), a memory cell is configured by the access transistor 10 and the TMR element 26 on the P-type substrate 7. The word line 9 and the bit line 11 are formed in a fine linear pattern according to the cell size. Further, the wiring layer 25 of the TMR element 26 is arranged in the vertical direction, and the lower portion is connected to one of the source / drain regions 8, and the bit wire 11 is connected to the other of the source / drain regions 8 via the connection hole 12. Be connected. Further, 5a is a common electrode of a flat plate arranged in the vertical direction of the TMR element 26 and connected to the upper part of the wiring layer 25, and is arranged so as to cover the entire chip or a cell array blocked in several blocks. .. Reference numeral 13 denotes a laminated interlayer insulating film.

【0037】

Next, the operation of MRAM will be described. The potential of the common electrode 5a is set to half the value of the normal power supply voltage, and the potential of the bit wire 11 is set to the ground potential or the power supply potential. Here, when a voltage is applied to the word line 9 to turn on the access transistor 10, a current path of the common electrode 5a-wiring layer 25-access transistor 10-bit line 11 is created, and the direction of the current is determined by the potential of the bit line 11. It is determined. The current flowing through the wiring layer 25 is monitored, and the spin direction is detected by the magnitude of the current. When a relatively large current flows, the spin direction of the spin free layer 23 does not change by reading. If it is difficult for the current to flow immediately after applying the voltage to the word line 9, energy is consumed to reversely align the pre-written spins, and the spin of the spin free layer 23 before applying the voltage to the word line 9 The direction is detected. In this case, since the spin direction changes, the potential of the bit wire 11 is reversed, a current in the reverse direction of the wiring layer 25 is passed, and writing is performed again.

【0038】

In this embodiment, a rotating magnetic field is generated around the wiring layer 25, and the spin is set in the circumferential direction of the cylinder of the spin free layer 23. Therefore, the generated rotating magnetic field can be efficiently used and the spins can be aligned. It's easy. Therefore, the current required for writing can be reduced, and the writing operation is completed with a small writing current. Further, since the cylindrical TMR element 26 is arranged in the vertical direction, the occupied area can be reduced, and the TMR element 26 having a structure suitable for miniaturization and integration can be obtained. Further, in the MRAM using such a TMR element 26, the occupied area of the TMR element 4 is small, the word line 9 and the bit line 11 can be formed in a fine linear pattern, and the word line 9 is one. Since only one memory cell is required, miniaturization and integration can be significantly promoted. Further, since the columnar wiring layer 25 is formed through the insulating layer 24 so as to penetrate the inside of the cylinder of the spin free layer 23 to form the TMR element 26, the structure of the TMR element 26 is further simplified, and the structure of the TMR element 26 is further simplified. The memory cell structure is simplified.

【0039】

In this embodiment, the MRAM provided with the access transistor 10 has been shown, but as shown in the fourth embodiment, a diode forming a PN junction may be provided, and further miniaturization and integration can be achieved. Can be promoted.

【0040】

[Effect of the invention]

The magnetic resistance storage element according to claim 1 according to the present invention has a cylindrical first magnetic material having a variable magnetization direction and one end open, and an insulating layer inside the cylinder of the first magnetic material. It is provided with a columnar second magnetic material whose magnetization direction is fixed in one circumferential direction, and a rotating magnetic field is generated by passing a tunnel current between the first and second magnetic materials. To set the magnetization direction of the first magnetic material to one or the other circumferential direction, and use the change in magnetic resistance due to the magnetization direction of the first magnetic material with respect to the magnetization direction of the second magnetic material as a binary signal. , The current value required for writing can be reduced, the occupied area can be reduced, and the structure of the magnetic resistance storage element suitable for miniaturization and integration can be provided.

【0041】

Further, the magnetic resistance storage element according to claim 2 according to the present invention is integrally composed of a columnar pattern and a cylindrical pattern arranged around the columnar pattern with one end open, with a variable magnetization direction. The first magnetic material and the cylindrical pattern of the first magnetic material were formed around the columnar pattern via an insulating layer, the magnetization direction was fixed in one circumferential direction, and one end was opened. It is provided with a cylindrical second magnetic material, and a rotating magnetic field is generated by passing a tunnel current between the first and second magnetic materials to rotate the magnetization direction of the first magnetic material in one or the other circumference. Since the direction is set and the change in magnetic resistance due to the magnetization direction of the first magnetic material with respect to the magnetization direction of the second magnetic material is used as a binary signal, the current value required for writing can be reduced and the current value required for reading can be reduced. The reliability of the magnetic resistance storage element can be improved, the occupied area can be reduced, and the structure of the magnetic resistance storage element suitable for miniaturization and integration can be provided.

【0042】

Further, in claim 1 or 2, the reluctance storage element according to claim 3 according to the present invention has a large surface area by roughening the surfaces of the first magnetic material and the second magnetic material facing each other. Noise during reading can be reduced and reliability is improved.

【0043】

Further, in the magnetic resistance storage element according to claim 4 according to the present invention, in any one of claims 1 to 3, the insulating layer formed on the inner bottom of the cylinder of the magnetic material is formed from the insulating layer formed on the inner side wall of the cylinder. However, since the film thickness is thick, the current is suppressed from concentrating on the inner bottom of the cylinder, and the reliability at the time of reading is improved.

【0044】

Further, the magnetic resistance storage element according to claim 5 according to the present invention has a cylindrical magnetic material having a variable magnetization direction and open ends, and an insulating layer so as to penetrate the inside of the cylinder of the magnetic material. A columnar wiring layer formed is provided, and a rotating magnetic field is generated by passing a current through the wiring layer to set the magnetization direction of the magnetic material in one or the other circumferential direction, and the current flowing through the wiring layer is set. Since the magnetizing direction of the magnetic material is read out in different sizes, the current value required for writing can be reduced, the occupied area can be reduced, and a simple structure of a magnetic resistance storage element suitable for miniaturization and integration can be provided.

【0045】

The magnetic random access memory device according to claim 6 according to the present invention comprises the magnetic resistance storage element according to any one of claims 1 to 4, the access transistor, and the magnetic resistance storage element on a semiconductor substrate. Since a common electrode formed on the upper layer is provided and one magnetic material of the magnetoresistive memory element is connected to the common electrode and the other is connected to the access transistor, miniaturization and integration of the magnetic random access memory device can be promoted. At the same time, the current value required for writing can be reduced.

【0046】

The magnetic random access memory device according to claim 7 according to the present invention includes the magnetic resistance storage element according to any one of claims 1 to 4, a diode forming a PN junction, and the magnetism on a semiconductor substrate. A common electrode formed on the upper layer of the resistance storage element is provided, and one magnetic material of the magnetic resistance storage element is connected to the common electrode and the other is connected to the diode. Therefore, the magnetic random access memory device is miniaturized and integrated. Can be further promoted, and the current value required for writing can be reduced.

【0047】

The magnetic random access memory device according to claim 8 according to the present invention is common to the magnetic resistance storage element according to claim 5, the access transistor, and the upper layer of the magnetic resistance storage element on the semiconductor substrate. Since an electrode is provided and a columnar wiring layer of the magnetoresistive memory element is arranged in the vertical direction to form a wiring for connecting the common electrode and the access transistor, miniaturization and integration of the magnetic random access memory device are promoted. At the same time, the current value required for writing can be reduced.

【0048】

The magnetic random access memory device according to claim 9 according to the present invention has the magnetic resistance storage element according to claim 5, the diode forming the PN junction, and the upper layer of the magnetic resistance storage element on the semiconductor substrate. Since the formed common electrode is provided and the columnar wiring layer of the magnetoresistive memory element is arranged in the vertical direction to form a wiring for connecting the common electrode and the diode, the magnetic random access memory device is miniaturized and integrated. It is possible to further promote the conversion and reduce the current value required for writing.

【0049】

The magnetic random access memory device according to claim 10 according to the present invention has the first conductive type well region formed on the semiconductor substrate and the magnetoresistive storage element formed in the well region according to claim 7 or 9. Since the diode is composed of the second conductive type diffusion layer connected to the above, a magnetic random access memory device capable of further promoting miniaturization and integration and reducing the current value required for writing can be surely obtained.

【0050】

The magnetic random access memory device according to claim 11 according to the present invention uses the SOI substrate as the semiconductor substrate in claim 7 or 9, and is of the first and second conductive types formed on the SOI substrate and adjacent to each other. Since the diode is composed of the diffusion layer, a magnetic random access memory device that can further promote miniaturization and integration and reduce the current value required for writing can be surely obtained.

【0051】

Further, in the magnetic random access memory device according to claim 12 according to the present invention, in claim 7 or 9, the wiring layer formed on the semiconductor substrate and the magnetoresistive memory element are connected via a connection hole, and the connection is made. Since the diode is configured in the hole in the vertical direction, a magnetic random access memory device that can further promote miniaturization and integration and reduce the current value required for writing can be surely obtained.

[Simple explanation of drawings]

[Figure 1]

It is sectional drawing which shows the structure of the TMR element and MRAM by Embodiment 1 of this invention.

[Figure 2]

It is sectional drawing which shows the structure of the TMR element by Embodiment 2 of this invention.

[Fig. 3]

It is sectional drawing which shows the structure of the TMR element by Embodiment 3 of this invention.

[Fig. 4]

It is sectional drawing which shows the structure of MRAM according to Embodiment 4 of this invention.

[Fig. 5]

It is sectional drawing which shows the structure of the modification of Embodiment 4 of this invention.

[Fig. 6]

It is sectional drawing which shows the structure of the modification of Embodiment 4 of this invention.

[Fig. 7]

It is sectional drawing which shows the structure of the modification of Embodiment 4 of this invention.

[Fig. 8]

It is sectional drawing which shows the structure of the TMR element by Embodiment 5 of this invention.

[Fig. 9]

It is sectional drawing which shows the structure of the TMR element and MRAM according to Embodiment 6 of this invention.

[Fig. 10]

It is sectional drawing which shows the structure of the conventional MRAM.

[Fig. 11]

It is a figure explaining the operation of the conventional MRAM.

[Explanation of symbols]

1,1a Spin free layer as first magnetic material, 2,2a, 2b insulating layer, 3,3a Spin fixed layer as second magnetic material, 4,4a TMR element as magnetic resistance storage element, 5a common Electrode, 5b Bit wire as common electrode, 7 Semiconductor substrate, 7a SOI substrate as semiconductor substrate, 10 access transistor, 14-well region, 15 diffusion layer, 16,16a, 16b diode, 17b, 17c wiring layer, 19 diffusion layer , 23 Spin free layer as first magnetic material, 24 Insulation layer, 25 Columnar wiring layer, 26 TMR element as magnetic resistance storage element, X, Ya, Yb Spin direction (magnetization direction).