Magnetic random access memory

Abstract

The invention provides a magnetic random access memory. The magnetic random access memory comprises a memory array which comprises a plurality of first memory units and a plurality of second memory units, the plurality of first memory units are distributed on the periphery of the plurality of second memory units, and each first memory unit and each second memory unit respectively comprise a first ferromagnetic layer, a tunneling barrier layer and a second ferromagnetic layer which are stacked in sequence, the first ferromagnetic layer is provided with a first surface, the second ferromagnetic layer is provided with a second surface, and the vertical distance between the first surface and the second surface in the first extension direction is a first height; the magnetic shielding structure comprises a magnetic shielding layer and / or at least one magnetic shielding column, the magnetic shielding layer is located on the side, away from the tunneling barrier layer, of the first ferromagnetic layer, the storage array has a projection on the magnetic shielding layer, each magnetic shielding column has a second height in the first extension direction, and the second height is larger than or equal to the first height; the magnetic shielding column surrounds the periphery of the plurality of first storage units.

Description

Technical Field

[0001] The present invention relates to the field of memory technology, and in particular to a magnetic random access memory. Background Art

[0002] Magnetoresistive Random-Access Memory (MRAM) and TMR magnetic sensors are chips based on MTJ as the basic unit, and are extremely sensitive to interference from external magnetic fields. Taking MRAM chips as an example, when the magnitude of the external magnetic field reaches 0.01 Tesla, the critical write voltage of MTJ will increase significantly, resulting in an increase in write errors of MRAM chips. Not only that, when the external magnetic field reaches 0.1 Tesla, the magnetic moment in MTJ will have a high probability of random flipping, which will completely destroy the non-volatile data retention capability of the MRAM chip. For TMR magnetic sensors, magnetic field disturbances perpendicular to the detection axis will increase the error of the sensor's output signal and affect the accuracy of sensor detection. Therefore, in order to improve the chip's anti-magnetic ability, under normal circumstances, chips based on MTJ as a unit should be configured with a structure with certain anti-magnetic properties, thereby improving the chip's reliability in a magnetic field environment.

[0003] At present, common magnetic shielding technologies are divided into two categories, one is to introduce anti-magnetic structure at the chip packaging level, and the other is to introduce anti-magnetic structure at the device micro-machining level. Among them, the advantage of chip-level anti-magnetic packaging at the chip packaging level is that the process is relatively simple and easy to popularize, but its processing steps include wire leads, welding and other processes, and the packaging form must be customized according to the actual size of the chip, and the cost of consumables is relatively high; the device-level anti-magnetic structure at the device micro-machining level is to wrap anti-magnetic materials near the MTJ bit through micro-machining means, and its processing consumables cost is low, and the processing process is not affected by the chip routing and actual specifications. Its disadvantage is that the process is relatively complicated, the processing precision is extremely high, and it is difficult to promote and use.

[0004] Therefore, there is an urgent need for a magnetic random access memory to at least solve the problem that the anti-magnetic structure of the current magnetic random access memory chip is difficult to process. Summary of the invention

[0005] The main purpose of the present invention is to provide a magnetic random access memory to solve the problem that the anti-magnetic structure of the magnetic random access memory in the prior art is difficult to process.

[0006] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a magnetic random access memory is provided, comprising: a storage array, comprising a plurality of first storage units and a plurality of second storage units, the plurality of first storage units are distributed at the periphery of the plurality of second storage units, and each of the first storage unit and each of the second storage units comprises a first ferromagnetic layer, a tunneling barrier layer and a second ferromagnetic layer stacked in sequence, wherein the first ferromagnetic layer has a first surface away from the tunneling barrier layer, the second ferromagnetic layer has a second surface away from the tunneling barrier layer, the vertical distance between the first surface and the second surface in a first extension direction is a first height, and the first extension direction is a direction from the first ferromagnetic layer to the second ferromagnetic layer; a magnetic shielding structure, comprising a magnetic shielding layer and / or at least one magnetic shielding column, the magnetic shielding layer is located on a first side, the first side is a side of the first ferromagnetic layer away from the tunneling barrier layer, the storage array has a projection on the magnetic shielding layer, each magnetic shielding column has a second height in the first extension direction, and the second height is greater than or equal to the first height, wherein, in the case where there is one magnetic shielding column, the magnetic shielding column surrounds the periphery of the plurality of first storage units, and in the case where there are multiple magnetic shielding columns, the multiple magnetic shielding columns are distributed at the periphery of the plurality of first storage units.

[0007] Furthermore, the magnetic shielding layer is arranged in contact with at least one magnetic shielding column.

[0008] Furthermore, a plurality of magnetic shielding columns are arranged at intervals, and each magnetic shielding column has a projection on the magnetic shielding layer.

[0009] Furthermore, multiple magnetic shielding columns are arranged at intervals, the projection of each magnetic shielding column on a preset horizontal plane is a first projection, the projection of the magnetic shielding layer on the preset horizontal plane is a third projection, one side of the first projection coincides with one side of the third projection, and the preset horizontal plane is a plane parallel to the first surface.

[0010] Furthermore, the shape of the first projection is L-shaped, the number of the first projections is 4, each first projection has a first side and a second side away from the storage array, and the extension lines of the 4 first sides and the extension lines of the 4 second sides form a rectangle.

[0011] Furthermore, the magnetic random access memory includes an array area having a storage array and a logic area adjacent to the array area, wherein the logic area has a bottom metal wiring layer and a conductive path sequentially stacked along a first extension direction, and the magnetic shielding layer is also located on the second side, which is the side of the conductive path away from the bottom metal wiring layer.

[0012] Furthermore, the magnetic shielding column has a relative top surface and bottom surface in the first extension direction, and the magnetic random access memory also includes: a bottom metal wiring layer, which is located on the side of each second ferromagnetic layer away from the tunneling barrier layer, and the surface of the bottom metal wiring layer away from the second ferromagnetic layer is a third surface, the distance between the top surface and the third surface is a first distance, the distance between the bottom surface and the first surface is a second distance, the first distance is equal to the second distance, and the first distance is greater than the first height.

[0013] Furthermore, the magnetic shielding column has a relative top surface and bottom surface in the first extension direction, and the magnetic random access memory also includes: a top metal wiring layer, located between the magnetic shielding layer and each first ferromagnetic layer, and the surface of the top metal wiring layer away from the first ferromagnetic layer is a fourth surface, the distance between the top surface and the fourth surface is a third distance, the distance between the bottom surface and the second surface is a fourth distance, the third distance is equal to the fourth distance, and the third distance is greater than the first height.

[0014] Furthermore, the material of the magnetic shielding structure is a soft magnetic material.

[0015] Furthermore, the material of the magnetic shielding layer is an insulating soft magnetic material, and the material of at least one magnetic shielding column is a metallic soft magnetic material.

[0016] The technical solution of the present invention is applied to provide a magnetic random access memory, which includes a storage array and a magnetic shielding structure, wherein the magnetic shielding structure includes a magnetic shielding layer and at least one magnetic shielding column. The storage array includes a plurality of first storage units and a plurality of second storage units, wherein the plurality of first storage units are distributed at the periphery of the plurality of second storage units, and each first storage unit and each second storage unit include a first ferromagnetic layer, a tunneling barrier layer, and a second ferromagnetic layer stacked in sequence, wherein each first storage unit and each second storage unit have a first height in the first extension direction, that is, the first height is the vertical distance between each first ferromagnetic layer and each corresponding second ferromagnetic layer, and the first extension direction is the direction from the first ferromagnetic layer to the second ferromagnetic layer. In one aspect, when the magnetic shielding structure includes at least one magnetic shielding column, due to the at least one magnetic The shielding column is located on one side of the plurality of first storage units away from the plurality of second storage units (that is, when there is one magnetic shielding column, the magnetic shielding column surrounds the periphery of the plurality of first storage units; when there are multiple magnetic shielding columns, the multiple magnetic shielding columns are distributed on the periphery of the plurality of first storage units), and at least one magnetic shielding column has a second height in the first extension direction, and the second height is greater than or equal to the first height, so that the at least one magnetic shielding column can shield the external magnetic field that interferes with the plurality of first storage units and the plurality of second storage units in the storage array. Therefore, the at least one magnetic shielding column in the present solution has the ability to shield external magnetic field interference, and since the at least one magnetic shielding column is only located at the magnetic random The outermost side of the storage array of the memory, therefore, compared with the magnetic shielding structure (antimagnetic structure) of the magnetic random access memory in the prior art, the size of the at least one magnetic shielding column can be larger, and can reach the micron level to the quasi-millimeter level, thereby significantly reducing the difficulty of processing the magnetic shielding structure (antimagnetic structure) of the magnetic random access memory; in addition, compared with the storage array of the magnetic random access memory in the prior art, the spacing between any two adjacent storage cells (the first storage cell and the adjacent first storage cell, the second storage cell and the adjacent second storage cell, and the first storage cell and the adjacent second storage cell) in the storage array of the magnetic random access memory can be smaller, which is beneficial to the magnetic random access memory. The storage density of the memory; on the other hand, when the above-mentioned magnetic shielding structure includes a magnetic shielding layer, since the magnetic shielding layer is located on the side of the first ferromagnetic layer of the multiple first storage units and the multiple second storage units away from the tunneling barrier layer, the size of the magnetic shielding layer is also relatively large, so that it not only has the ability to shield external magnetic field interference, but also can significantly reduce the processing difficulty of the magnetic shielding structure (antimagnetic structure) of the random access memory; on another hand, when the above-mentioned magnetic shielding structure includes a magnetic shielding layer and at least one magnetic shielding column at the same time, the above-mentioned magnetic shielding structure can form a full-range magnetic shielding function for the storage array of the magnetic random access memory, so that the random access memory has good electrical reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0018] Figure 1 A schematic cross-sectional structure diagram of a magnetic random access memory according to an embodiment of the present invention is shown;

[0019] Figure 2 A projection schematic diagram of an embodiment of a magnetic shielding structure in a magnetic random access memory according to an embodiment of the present invention is shown;

[0020] Figure 3 A projection schematic diagram of an embodiment of a magnetic shielding structure in a magnetic random access memory according to an embodiment of the present invention is shown;

[0021] Figure 4 A projection schematic diagram of an embodiment of a magnetic shielding structure in a magnetic random access memory according to an embodiment of the present invention is shown;

[0022] Figure 5 A projection schematic diagram of an embodiment of a magnetic shielding structure in a magnetic random access memory according to an embodiment of the present invention is shown;

[0023] Figure 6 A projection schematic diagram of an embodiment of a magnetic shielding structure in a magnetic random access memory according to an embodiment of the present invention is shown;

[0024] Figure 7 A projection schematic diagram of an embodiment of a magnetic shielding structure in a magnetic random access memory according to an embodiment of the present invention is shown;

[0025] Figure 8 A projection schematic diagram of an embodiment of a magnetic shielding structure in a magnetic random access memory according to an embodiment of the present invention is shown;

[0026] Fig. 9 A schematic cross-sectional structure diagram of a semiconductor substrate of a magnetic random access memory according to an embodiment of the present invention is shown;

[0027] Fig.10 Shown in Fig. 9 A schematic cross-sectional structure diagram of an insulating dielectric layer and a soft magnetic material formed on a semiconductor substrate shown;

[0028] Fig.11 Shows the etching Fig.10 A schematic diagram of the cross-sectional structure of the soft magnetic material shown;

[0029] Fig.12 Shown in Fig.11 A schematic cross-sectional structure diagram of an insulating dielectric layer formed on the structure shown;

[0030] Fig.13 Shown in Fig.12 A schematic diagram of a cross-sectional structure of a top connecting portion formed on the structure shown;

[0031] Fig.14 Shown in Fig.10 A schematic cross-sectional structure diagram of an insulating dielectric layer formed on the structure shown;

[0032] Fig.15 Shown in Fig.14 A schematic diagram of a cross-sectional structure of a top connecting portion formed on the structure shown;

[0033] Fig.16 A schematic cross-sectional structure diagram of another semiconductor substrate of a magnetic random access memory according to an embodiment of the present invention is shown;

[0034] Fig.17 Shown in Fig.16 A schematic cross-sectional structure diagram of an insulating dielectric layer and a soft magnetic material deposited on a semiconductor substrate shown;

[0035] Fig.18 Shows the etching Fig.17 A schematic diagram of the cross-sectional structure of the soft magnetic material shown;

[0036] Fig.19 Shown in Fig.18 A schematic diagram of a cross-sectional structure of a top connecting portion formed on the structure shown;

[0037] Fig. 20 Shown in Fig.17 A schematic cross-sectional structure diagram of a top connection portion formed on the structure shown.

[0038] The above drawings include the following reference numerals:

[0039] 10. Storage array; 20. First storage unit; 30. Second storage unit; 201. First ferromagnetic layer; 202. Tunneling barrier layer; 203. Second ferromagnetic layer; 40. Magnetic shielding layer; 50. Magnetic shielding column; 60. Conductive path; 70. Bottom metal wiring layer; 80. Top metal wiring layer; 90. Semiconductor substrate; 100. Soft magnetic material; 110. Diffusion barrier layer; 120. Top connection part. DETAILED DESCRIPTION

[0040] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0041] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0042] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so as to describe the embodiments of the present invention described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0043] As described in the background technology, the common magnetic shielding technologies are currently divided into two categories, one is to introduce anti-magnetic structures at the chip packaging level, and the other is to introduce anti-magnetic structures at the device micro-machining level. Among them, the advantage of chip-level anti-magnetic packaging at the chip packaging level is that the process is relatively simple and easy to popularize, but its processing steps include processes such as leads and welding, and the packaging form must be customized according to the actual size of the chip, and the cost of consumables is relatively high; the device-level anti-magnetic structure at the device micro-machining level is to wrap anti-magnetic materials near the MTJ bit by micro-machining means, and its processing consumables cost is low, and the processing flow is not affected by the chip routing and actual specifications. Its disadvantage is that the process is relatively complicated, the processing precision is extremely high, and it is difficult to promote and use. Therefore, in order to at least solve the problem of the difficulty of processing the anti-magnetic structure of the current magnetic random access memory chip, the applicant of this application has proposed a magnetic random access memory.

[0044] According to one aspect of the present application, a magnetic random access memory is provided, such as Figure 1As shown, the magnetic random access memory includes a storage array 10, including a plurality of first storage units 20 and a plurality of second storage units 30, wherein the plurality of first storage units 20 are distributed at the periphery of the plurality of second storage units 30, and each of the first storage units 20 and each of the second storage units 30 includes a first ferromagnetic layer 201, a tunneling barrier layer 202, and a second ferromagnetic layer 203 stacked in sequence, wherein the first ferromagnetic layer 201 has a first surface away from the tunneling barrier layer 202, the second ferromagnetic layer 203 has a second surface away from the tunneling barrier layer 202, the vertical distance between the first surface and the second surface in a first extension direction is a first height, and the first extension direction is the first ferromagnetic layer. Layer 201 points in the direction of the second ferromagnetic layer 203; a magnetic shielding structure, including a magnetic shielding layer 40 and / or at least one magnetic shielding column 50, the magnetic shielding layer 40 is located on a first side, the first side is a side of the first ferromagnetic layer 201 away from the tunneling barrier layer 202, the storage array 10 has a projection on the magnetic shielding layer 40, each magnetic shielding column 50 has a second height in the first extension direction, the second height is greater than or equal to the first height, wherein, in the case of one magnetic shielding column 50, the magnetic shielding column 50 surrounds the periphery of the plurality of first storage units 20, and in the case of multiple magnetic shielding columns 50, the plurality of magnetic shielding columns 50 are distributed on the periphery of the plurality of first storage units 20.

[0045] Optionally, the magnetic random access memory may further include a top metal wiring layer 80 and a bottom metal wiring layer 70, wherein the top metal wiring layer 80, the first ferromagnetic layer 201, the tunneling barrier layer 202, the second ferromagnetic layer 203 and the bottom metal wiring layer 70 are stacked.

[0046] Optionally, the thickness of the magnetic shielding layer 40 may be greater than or equal to 50 nm.

[0047] Specifically, the plurality of second storage units 30 may be arranged in an array, and exemplarily, the array may be n×m, wherein n and m may be equal to 1, or may be equal to k times of 2, k being greater than or equal to 1, and the number of n and m may be reasonably selected according to the actual needs of those skilled in the art, and generally, the number of n ranges from several thousand to several million. Further, since the storage array 10 of the magnetic random access memory also includes a plurality of first storage units 20, and the plurality of first storage units 20 are distributed on the periphery of the plurality of second storage units 30, exemplarily, in the case where the arrangement of the plurality of second storage units 30 is n×m, the number of the plurality of first storage units 20 may be k[2(n×m)+2], and k being greater than or equal to 1. Further, the storage array 10 includes the plurality of first storage units 20 and the plurality of second storage units 30, and in the case where the k is equal to 1 and the plurality of second storage units 30 are arranged in n×m, the storage array 10 is arranged in (n+1)×(m+1).

[0048] Specifically, each of the first storage units 20 and each of the second storage units 30 may be storage units having the same structure. Exemplarily, each of the first storage units 20 includes a first ferromagnetic layer 201, a tunneling barrier layer 202, and a second ferromagnetic layer 203 that are sequentially stacked, and each of the second storage units 30 also includes a first ferromagnetic layer 201, a tunneling barrier layer 202, and a second ferromagnetic layer 203 that are sequentially stacked, wherein, when a side surface of the first ferromagnetic layer 201 away from the tunneling barrier layer 202 and the second ferromagnetic layer 203 is taken as a first surface, and a side surface of the second ferromagnetic layer 203 away from the tunneling barrier layer 202 and the first ferromagnetic layer 201 is taken as a second surface, the height of each of the first storage units 20 and each of the second storage units 30 in the first extension direction is the vertical distance from the first surface to the second surface.

[0049] Specifically, the magnetic shielding structure in some embodiments of the present scheme may only include a magnetic shielding layer 40, the magnetic shielding structure in other embodiments of the present scheme may only include one magnetic shielding column 50, the magnetic shielding structure in still some embodiments of the present scheme may only include multiple magnetic shielding columns 50, the magnetic shielding structure in still some embodiments of the present scheme may include a magnetic shielding structure and a magnetic shielding column 50, or may include a magnetic shielding structure and multiple magnetic shielding columns 50. Further, the side of the first ferromagnetic layer 201 of each first storage unit 20 and each second storage unit 30 away from the tunneling barrier layer 202 is a first side. In some embodiments including a magnetic shielding layer 40, the magnetic shielding layer 40 is located on the first side. It can be understood that the magnetic shielding layer 40 is a continuous layer, so that the magnetic shielding layer 40 can be located on the side of the first ferromagnetic layer 201 of each first storage unit 20 away from the tunneling barrier layer 202 and on the side of the first ferromagnetic layer 201 of each second storage unit 30 away from the tunneling barrier layer 202, so that the storage array 10 has a projection on the magnetic shielding layer 40.

[0050] Furthermore, in some embodiments including the magnetic shielding column 50, the magnetic shielding column 50 has a second height in the first extension direction, and the second height may be greater than or equal to the first height, wherein when the second height is equal to the first height, one surface (top surface) of the magnetic shielding column 50 in the first extension direction is flush with the first surface, and the other surface (bottom surface) of the magnetic shielding column 50 in the first extension direction is flush with the second surface, so that the magnetic shielding column 50 can play a role in shielding the external magnetic field. Exemplarily, in the case where there is one magnetic shielding column 50, the magnetic shielding column 50 may be a semi-enclosed structure surrounding the periphery of multiple first storage units 20 of the storage array 10. Exemplarily, the vertical projection of the magnetic shielding column 50 on a preset horizontal plane (a surface parallel to the first surface) may include a first side, a second side, a third side, a fourth side and a fifth side, wherein one end of the first side is connected to one end of the second side at a right angle, the other end of the second side is connected to one end of the third side at a right angle, and the first side and the third side have the same extension direction, the other end of the third side is connected to one end of the fourth side at a right angle, and the second side and the fourth side have the same extension direction, the other end of the fourth side is connected to one end of the fifth side at a right angle, and the fifth side and the third side have the same extension direction, and the other end of the fifth side does not contact the other end of the first side. Exemplarily, in the case where there are multiple magnetic shielding columns 50, the multiple magnetic shielding columns 50 are arranged at intervals, and each first storage unit 20 located at the outermost side of the storage array 10 is provided with a magnetic shielding column 50 on the side away from each second storage unit 30, that is, the multiple magnetic shielding columns 50 are distributed on the periphery of the multiple first storage units 20.

[0051] Therefore, compared with the magnetic random access memory in the prior art, the magnetic random access memory of the present application, on the one hand, since the at least one magnetic shielding column 50 is located on the side of the multiple first storage units 20 away from the multiple second storage units 30, and the at least one magnetic shielding column 50 has a second height in the first extension direction, and the second height is greater than or equal to the first height, so that the at least one magnetic shielding column 50 can shield the external magnetic field that interferes with the multiple first storage units 20 and the multiple second storage units 30 in the storage array 10, so the at least one magnetic shielding column 50 in the present solution has the ability to shield external magnetic field interference, and since the at least one magnetic shielding column 50 is only located at the outermost side of the storage array 10 of the magnetic random access memory, the size of the at least one magnetic shielding column 50 of the present application can be larger, and can reach the micron level to the quasi-millimeter level, thereby significantly reducing the processing difficulty of the magnetic shielding structure (antimagnetic structure) of the magnetic random access memory; in addition, compared with the storage array 10 of the magnetic random access memory in the prior art, the storage array of the magnetic random access memory The spacing between any two adjacent storage units in 10 (the first storage unit 20 and the adjacent first storage unit 20, the second storage unit 30 and the adjacent second storage unit 30, and the first storage unit 20 and the adjacent second storage unit 30) can be smaller, which is beneficial to the storage density of the magnetic random access memory; on the other hand, when the above-mentioned magnetic shielding structure includes a magnetic shielding layer 40, since the magnetic shielding layer 40 is located on the side of the first ferromagnetic layer 201 of the multiple first storage units 20 and the multiple second storage units 30 away from the tunneling barrier layer 202, the size of the magnetic shielding layer 40 is also relatively large, so that it not only has the ability to shield external magnetic field interference, but also can significantly reduce the processing difficulty of the magnetic shielding structure (antimagnetic structure) of the random access memory; on the other hand, when the above-mentioned magnetic shielding structure includes both the magnetic shielding layer 40 and at least one magnetic shielding column 50, the above-mentioned magnetic shielding structure can form a full-range magnetic shielding function for the storage array 10 of the magnetic random access memory, so that the random access memory has good electrical reliability.

[0052] In some optional embodiments, such as Figure 1 As shown, the magnetic random access memory includes an array area having a storage array 10 and a logic area adjacent to the array area, wherein the logic area has a bottom metal wiring layer 70 and a conductive path 60 sequentially stacked along a first extension direction, and the magnetic shielding layer 40 is also located on the second side, which is the side of the conductive path 60 away from the bottom metal wiring layer 70.

[0053] Specifically, the array area not only has a storage array 10, but also has a magnetic shielding structure, which may include the magnetic shielding layer 40 and at least one magnetic shielding column 50. The arrangement of the magnetic shielding layer 40 and at least one magnetic shielding column 50 in this embodiment refers to any one of the arrangement methods in this application, and will not be repeated here. Further, in the above embodiment, in order to enable the magnetic random access memory to have a better shielding effect on the external magnetic field, the magnetic shielding layer 40 is also arranged on the side of the conductive path 60 of the logic area away from the bottom metal wiring layer 70. It can be understood that the upper surface of the conductive path 60 located in the logic area away from the bottom metal wiring layer 70 is used for electrical connection. Therefore, the upper surface of the conductive path 60 is not covered by the magnetic shielding layer 40. Exemplarily, the magnetic shielding layer 40 of the logic area and the magnetic shielding layer 40 in the array area are electrically connected continuous magnetic shielding layers 40, and the metal wiring in any of the above embodiments is used to interconnect the array area and the logic.

[0054] In some optional ways, such as Figure 1 As shown, the magnetic shielding column 50 has a relative top surface and bottom surface in the first extension direction, and the magnetic random access memory also includes: a bottom metal wiring layer 70, which is located on the side of each second ferromagnetic layer 203 away from the tunneling barrier layer 202, and the surface of the bottom metal wiring layer 70 away from the second ferromagnetic layer 203 is a third surface, the distance between the top surface and the third surface is a first distance, the distance between the bottom surface and the first surface is a second distance, the first distance is equal to the second distance, and the first distance is greater than the first height.

[0055] In the above embodiment, the second ferromagnetic layer 203 of each first storage unit 20 and each second storage unit 30 has the above-mentioned bottom metal wiring layer 70 on the side away from the tunneling barrier layer 202, and the bottom metal wiring layer 70 is electrically connected to the above-mentioned second ferromagnetic layer 203. The height of the above-mentioned magnetic shielding column 50 in the first extension direction is the second height, and the above-mentioned second height can be flush with the height extending from the first surface to the third surface (that is, the distance between the top surface and the third surface is the first distance, the distance between the bottom surface and the first surface is the second distance, and the first distance is equal to the second distance). Therefore, the height of the magnetic shielding column 50 is higher than the height of the first storage unit 20 and the second storage unit 30 in the storage array 10, so as to better shield the external magnetic field.

[0056] In some optional embodiments, such as Figure 1As shown, the magnetic shielding column 50 has a relative top surface and bottom surface in the first extension direction, and the magnetic random access memory also includes: a top metal wiring layer 80, located between the magnetic shielding layer 40 and each first ferromagnetic layer 201, and the surface of the top metal wiring layer 80 away from the first ferromagnetic layer 201 is a fourth surface, the distance between the top surface and the fourth surface is a third distance, the distance between the bottom surface and the second surface is a fourth distance, the third distance is equal to the fourth distance, and the third distance is greater than the first height.

[0057] Similarly, in the above-mentioned embodiment, the first ferromagnetic layer 201 of each first storage unit 20 and each second storage unit 30 has the above-mentioned top metal wiring layer 80 on the side away from the tunneling barrier layer 202, and the top metal wiring layer 80 is electrically connected to the above-mentioned first ferromagnetic layer 201, and the height of the above-mentioned magnetic shielding column 50 in the first extension direction is the second height, and the above-mentioned second height can be flush with the height extending from the fourth surface to the second surface (that is, the distance between the top surface and the fourth surface is the third distance, the distance between the bottom surface and the second surface is the fourth distance, and the third distance is equal to the fourth distance). Therefore, the height of the magnetic shielding column 50 is higher than the height of the first storage unit 20 and the second storage unit 30 in the storage array 10, so as to better shield the external magnetic field.

[0058] In some optional embodiments, when the magnetic shielding structure only includes the magnetic shielding layer 40, the vertical projection of the magnetic shielding layer 40 on the preset horizontal plane is as follows: Figure 2 As shown, the above-mentioned preset horizontal plane is a horizontal plane parallel to the first surface and the second surface.

[0059] In some optional embodiments, such as Figures 3 to 8 As shown, in order to achieve a better magnetic shielding effect for the magnetic random access memory, the magnetic shielding layer 40 is arranged in contact with at least one magnetic shielding column 50, so that the above-mentioned magnetic shielding structure has better sealing performance and can better shield the external magnetic field to prevent the external magnetic field from interfering with the magnetic random access memory.

[0060] Specifically, the magnetic shielding column 50 has a top surface and a bottom surface opposite to each other in the first extension direction. The magnetic shielding layer 40 may be located on a side of the first ferromagnetic layer of the storage array away from the tunneling barrier layer, and the magnetic shielding layer 40 may cover the top surface of the magnetic shielding column 50. Figure 3 , Figure 4 and Figure 5 or the magnetic shielding layer 40 may be in close contact with one side of the top surface of the magnetic shielding column 50, such as Figure 6 , Figure 7 and 8 or the magnetic shielding column 50 further has a side surface close to the first storage unit, the magnetic shielding layer 40 is disposed in close contact with the side surface, such as Figure 6 , Figure 7 and 8 As shown, the magnetic shielding column 50 can be one or a plurality of magnetic shielding columns 50 arranged at intervals.

[0061] In some optional embodiments, a plurality of magnetic shielding columns 50 are arranged at intervals, and each magnetic shielding column 50 has a projection on the magnetic shielding layer 40, such as Figure 3 , Figure 4 and Figure 5 Specifically, in the case where the magnetic shielding pillars 50 include a plurality of spaced-apart magnetic shielding pillars, since each magnetic shielding pillar 50 has a projection on the magnetic shielding layer 40 and the plurality of magnetic shielding pillars 50 are distributed on the periphery of the plurality of first storage units 20, the plurality of magnetic shielding pillars 50 and the storage array both have projections on the magnetic shielding layer 40.

[0062] Among them, the multiple first storage units in the above-mentioned embodiment can be distributed in an array, and the storage array has an inner side and an outer side. The inner side of the storage array refers to the side of the second storage unit away from the first storage unit, and correspondingly, the outer side of the storage array refers to the side of the first storage unit away from the second storage unit. In the above-mentioned embodiment, each magnetic shielding column 50 is set to have a projection on the magnetic shielding layer 40, that is, the magnetic shielding layer 40 completely covers the top surface of the magnetic shielding column 50 in the first extension direction, so that the magnetic shielding structure of the storage array has better sealing, thereby achieving the effect of shielding the external magnetic field, and because the magnetic shielding columns 50 are arranged at intervals, it is possible to have a first area between any two adjacent magnetic shielding columns 50, and the first area is used to set metal wiring.

[0063] In some optional embodiments, in order to achieve the effect of shielding the external magnetic field and save manufacturing costs, a plurality of magnetic shielding columns 50 are arranged at intervals, and the projection of each magnetic shielding column 50 on a preset horizontal plane is a first projection, and the projection of the magnetic shielding layer 40 on the preset horizontal plane is a second projection. One side of the first projection coincides with one side of the second projection, and the preset horizontal plane is a plane parallel to the first surface, such as Figure 6 , Figure 7 and 8 As shown. Specifically, in the case where the magnetic shielding columns 50 include a plurality of magnetic shielding columns 50 arranged at intervals, the projection of each magnetic shielding column 50 on the preset horizontal plane is a first projection, and the projection of the magnetic shielding layer 40 on the preset horizontal plane is a second projection, and since the plurality of magnetic shielding columns 50 are distributed on the periphery of the storage array, the projection of the storage array on the preset horizontal plane can be a third projection, and the third projection is located in the second projection, and one side of the first projection coincides with one side of the second projection. That is, in this embodiment, since the storage array is located in the magnetic shielding structure formed by the magnetic shielding columns 50 and the magnetic shielding layer 40, the magnetic shielding structure can achieve the function of shielding the external magnetic field, and since the area of ​​the magnetic shielding layer 40 is relatively small, a certain manufacturing cost can be saved.

[0064] In some optional embodiments, such as Figure 3 and Figure 6 As shown, the shape of the first projection is L-shaped, the number of the first projections is 4, each of the first projections has a first side and a second side away from the storage array, and the extension lines of the 4 first sides and the extension lines of the 4 second sides form a rectangle.

[0065] It is known that any one of the magnetic shielding columns 50 has a second height in the first extension direction, and it can be known from the present embodiment that since the shape of the first projection corresponding to the magnetic shielding column 50 is L-shaped, the first side and the second side of any one of the magnetic shielding columns 50 on the side away from the storage array constitute the above-mentioned L-shape. In one embodiment, the extension lines of the four first sides and the extension lines of the four second sides can first form a rectangle, and since the magnetic shielding column 50 can have a projection on the magnetic shielding layer 40, the above-mentioned first projection is located in the second projection of the magnetic shielding layer 40, such as Figure 3 In another embodiment, since the second projection of the magnetic shielding layer 40 can be a rectangle, when one side of the first projection can coincide with the four right-angled sides of the second projection, the extension lines of the four first sides and the extension lines of the four second sides form a rectangle, as shown in FIG. Figure 6 Therefore, any one of the magnetic shielding columns 50 can be used to shield the external magnetic field in two directions, and there is a certain interval between any two adjacent magnetic shielding columns 50, and the interval can be used to set metal wiring. Optionally, the interval between any two adjacent magnetic shielding columns 50 is equal.

[0066] In some optional embodiments, the material of the magnetic shielding structure is a soft magnetic material.

[0067] In the above-mentioned embodiments, since the soft magnetic material has a high magnetic permeability and a low coercive force, it can effectively absorb and disperse the magnetic field and reduce the interference of the magnetic field on the surrounding environment. Therefore, the magnetic shielding structure of the magnetic random access memory adopts a soft magnetic material, which can effectively shield the external magnetic field and reduce the interference of the external magnetic field on the magnetic random access memory. Optionally, the materials of the magnetic shielding layer and the magnetic shielding column in any of the above-mentioned embodiments can be soft magnetic materials, and the magnetic shielding layer can be a single soft magnetic material layer or a laminated structure of multiple soft magnetic materials. Exemplarily, the soft magnetic material can include a metal soft magnetic material and an insulating soft magnetic material. Wherein, in the case where the above-mentioned magnetic shielding layer is located on the first side and the second side at the same time, the material of the above-mentioned magnetic shielding layer can be an insulating material layer to prevent the magnetic random access memory from short-circuiting. Optionally, the above-mentioned metal soft magnetic material can include but is not limited to Ni, Fe and NiFe, etc., and the insulating soft magnetic material can include but is not limited to yttrium iron garnet (YttriumIron Garnet, YIG).

[0068] In some optional embodiments, the material of the magnetic shielding layer is an insulating soft magnetic material, and the material of at least one magnetic shielding column is a metallic soft magnetic material.

[0069] In the above embodiment, in order to prevent the magnetic shielding layer from contacting with metal wiring and causing a short circuit, the magnetic shielding layer is made of insulating soft magnetic material, and in order to reduce the processing difficulty of the magnetic shielding structure, when forming the magnetic shielding column, a metal soft magnetic material is used as the magnetic shielding column of the magnetic shielding structure.

[0070] According to another aspect of the present invention, the applicant of the present application also proposes a method for manufacturing a magnetic random access memory, specifically, a storage array can be first formed, and then a magnetic shielding structure can be formed, wherein the formed storage array can include multiple first storage units and multiple second storage units, the multiple first storage units are distributed on the periphery of the multiple second storage units, and each first storage unit and each second storage unit include a first ferromagnetic layer, a tunneling barrier layer and a second ferromagnetic layer stacked in sequence, and the first ferromagnetic layer has a first surface away from the tunneling barrier layer, the second ferromagnetic layer has a second surface away from the tunneling barrier layer, the vertical distance between the first surface and the second surface in the first extension direction is a first height, and the first extension direction is the direction from the first ferromagnetic layer to the second magnetic layer; the above-mentioned magnetic shielding structure formed may include a magnetic shielding layer and / or at least one magnetic shielding column, wherein at least one magnetic shielding column is located on a side of the multiple first storage units away from the multiple second storage units, and each magnetic shielding column has a second height in the first extension direction, the second height is greater than or equal to the first height, and the magnetic shielding layer is located on the first side, and the first side is the side of the first ferromagnetic layer away from the tunneling barrier layer.

[0071] Optionally, in the process of forming the above storage array, as Fig. 9 As shown, a semiconductor substrate 90 may be first manufactured, and the semiconductor substrate 90 may include a bottom metal wiring layer 70, a first storage unit 20, a second storage unit 30, and a top metal wiring layer 80. Each of the first storage unit 20 and the second storage unit 30 includes a first ferromagnetic layer 201, a tunneling barrier layer 202, and a second ferromagnetic layer 203 stacked in layers. Fig.10 As shown, an insulating material is deposited on the side of the top metal wiring layer 80 away from the bottom metal wiring layer 70, and the insulating material may include but is not limited to SiN and / or TEOS, etc., to form an insulating dielectric layer, and then a soft magnetic material 100 is deposited on the side of the insulating dielectric layer away from the top metal wiring layer 80 to form a magnetic shielding layer.

[0072] Further, the portion of the semiconductor substrate 90 having the first storage unit 20 and the second storage unit 30 may be an array region, and the portion without the first storage unit 20 and the second storage unit 30 may be a logic region, and the logic region is provided with a conductive path and a bottom metal wiring layer 70, and the magnetic shielding layer may be formed by depositing a soft magnetic material 100, wherein the soft magnetic material 100 may be located on a first side of the first ferromagnetic layer in the array region away from the second ferromagnetic layer, or may be located on a side of the conductive path in the logic region away from the bottom metal wiring layer 70. In some optional embodiments, such as Fig.11 As shown, the soft magnetic material 100 located in the logic area can be removed by etching process, and then Fig.12 As shown, an insulating dielectric layer is deposited on the side of the conductive path of the logic region away from the bottom metal wiring layer 70, and as shown Fig.13 As shown, the deposited insulating dielectric layer is still located on the upper surface of the magnetic shielding layer 40 in the array area, and then the diffusion barrier layer 110 is deposited again on the surface of the above-mentioned insulating dielectric layer, and the above-mentioned diffusion barrier layer 110 and the insulating dielectric layer are sequentially etched to form a through hole extending from the above-mentioned diffusion barrier layer 110 to the conductive path 60, and the through hole is filled to form a top connecting portion 120, and the remaining soft magnetic material 100 forms a magnetic shielding layer; in other optional embodiments, such as Fig.14 As shown, the soft magnetic material 100 located in the logic area can be retained, and then Fig.15 As shown, an insulating dielectric layer and a diffusion barrier layer 110 are sequentially deposited again on the side of the soft magnetic material 100 away from the insulating dielectric layer, and the diffusion barrier layer 110, the insulating dielectric layer, the soft magnetic material and the insulating dielectric layer are sequentially etched to form a top connecting portion 120 extending from the diffusion barrier layer 110 to the conductive path, and the remaining soft magnetic material forms a magnetic shielding layer 40.

[0073] In other optional embodiments, such as Fig.16 As shown, a semiconductor substrate 90 is provided, and in order to form a magnetic shielding column, an insulating dielectric layer can be deposited on the upper surface of the semiconductor substrate 90, and then the insulating dielectric layer and the semiconductor substrate 90 are sequentially etched to form a through hole extending from the upper surface to the lower surface of the semiconductor substrate 90, and the through hole is located on a side of a plurality of first storage cells 20 in the storage array away from a plurality of second storage cells 30, and each of the first storage cells 20 and the second storage cells 30 includes a first ferromagnetic layer 201, a tunneling barrier layer 202 and a second ferromagnetic layer 203 that are stacked, and then as shown Fig.17As shown, the soft magnetic material 100 is filled into the through hole to form the magnetic shielding column 50, and then the soft magnetic material 100 is deposited on the side of the insulating dielectric layer away from the top metal wiring layer 80. It can be understood that the soft magnetic material 100 can be located on the first side of the first ferromagnetic layer in the array area away from the second ferromagnetic layer, or on the side of the conductive path in the logic area away from the bottom metal wiring layer 70. In some optional embodiments, such as Fig.18 As shown in FIG. 1 , the soft magnetic material 100 on the side of the conductive path 60 in the logic area away from the bottom metal wiring layer 70 can be removed, and the remaining soft magnetic material 100 forms a magnetic shielding layer, and an insulating dielectric layer is deposited on the upper surface of the soft magnetic material 100, and the insulating dielectric layer is planarized, and then as shown in FIG. Fig.19 As shown, a diffusion barrier layer 110 is formed on the insulating dielectric layer, and the diffusion barrier layer 110 and the insulating dielectric layer are sequentially etched to form a through hole penetrating the diffusion barrier layer 110 to the conductive path 60, and the through hole is filled to form a top connecting portion 120; in other optional embodiments, as Fig. 20 As shown, the soft magnetic material 100 on the side of the conductive path 60 in the logic area away from the bottom metal wiring layer 70 can be retained, and an insulating dielectric layer is deposited on the soft magnetic material 100, and a diffusion barrier layer 110 is deposited on the insulating dielectric layer. The diffusion barrier layer 110 and the insulating dielectric layer are sequentially etched to form a through hole that penetrates the diffusion barrier layer 110 to the conductive path 60, and the through hole is filled to form a top connecting portion 120, and the remaining soft magnetic material 100 forms a magnetic shielding layer 40.

[0074] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0075] The magnetic random access memory comprises a storage array and a magnetic shielding structure, wherein the magnetic shielding structure comprises a magnetic shielding layer and at least one magnetic shielding column. Wherein, the storage array includes a plurality of first storage units and a plurality of second storage units, the plurality of first storage units are distributed on the periphery of the plurality of second storage units, and each first storage unit and each second storage unit include a first ferromagnetic layer, a tunneling barrier layer and a second ferromagnetic layer stacked in sequence, wherein each first storage unit and each second storage unit have a first height in a first extension direction, that is, the first height is the vertical distance between each first ferromagnetic layer and each corresponding second ferromagnetic layer, and the first extension direction is the direction in which the first ferromagnetic layer points to the second ferromagnetic layer. On the one hand, in the case where the magnetic shielding structure includes at least one magnetic shielding column, since the at least one magnetic shielding column is located on the side of the plurality of first storage units away from the plurality of second storage units, and the at least one magnetic shielding column has a second height in the first extension direction, and the second height is greater than or equal to the first height, the at least one magnetic shielding column can shield the external magnetic field that interferes with the plurality of first storage units and the plurality of second storage units in the storage array, so the at least one magnetic shielding column in this scheme has the ability to shield external magnetic field interference, and since the at least one magnetic shielding column is only located at the outermost side of the storage array of the magnetic random access memory, it is different from the magnetic shielding structure of the magnetic random access memory in the prior art. (anti-magnetic structure), the size of the at least one magnetic shielding column can be larger and can reach the micron level to the quasi-millimeter level, thereby significantly reducing the difficulty of processing the magnetic shielding structure (anti-magnetic structure) of the magnetic random access memory; in addition, compared with the storage array of the magnetic random access memory in the prior art, the distance between any two adjacent storage units (the first storage unit and the adjacent first storage unit, the second storage unit and the adjacent second storage unit, and the first storage unit and the adjacent second storage unit) in the storage array of the magnetic random access memory can be smaller, which is beneficial to the storage density of the magnetic random access memory; on the other hand, in the case where the magnetic shielding structure includes a magnetic shielding layer, since the magnetic shielding layer is located on the side of the first ferromagnetic layer of the multiple first storage units and the multiple second storage units away from the tunneling barrier layer, the size of the magnetic shielding layer is also larger, so that it not only has the ability to shield external magnetic field interference, but also can significantly reduce the difficulty of processing the magnetic shielding structure (anti-magnetic structure) of the random access memory; on the other hand, when the magnetic shielding structure includes both the magnetic shielding layer and at least one magnetic shielding column, the magnetic shielding structure can form a full range of magnetic shielding function for the storage array of the magnetic random access memory, so that the random access memory has good electrical reliability.

[0076] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A magnetic random access memory, characterized in that: include: A storage array, comprising a plurality of first storage units and a plurality of second storage units, wherein the plurality of first storage units are distributed at the periphery of the plurality of second storage units, and each of the first storage units and each of the second storage units comprises a first ferromagnetic layer, a tunneling barrier layer, and a second ferromagnetic layer stacked in sequence, wherein the first ferromagnetic layer has a first surface away from the tunneling barrier layer, the second ferromagnetic layer has a second surface away from the tunneling barrier layer, a vertical distance between the first surface and the second surface in a first extension direction is a first height, and the first extension direction is a direction from the first ferromagnetic layer to the second ferromagnetic layer; A magnetic shielding structure comprises a magnetic shielding layer and / or at least one magnetic shielding column, wherein the magnetic shielding layer is located on a first side, the first side being a side of the first ferromagnetic layer away from the tunneling barrier layer, the storage array having a projection on the magnetic shielding layer, each of the magnetic shielding columns having a second height in the first extension direction, the second height being greater than or equal to the first height, wherein when there is one magnetic shielding column, the magnetic shielding column surrounds the periphery of the plurality of first storage units, and when there are multiple magnetic shielding columns, the plurality of magnetic shielding columns are distributed on the periphery of the plurality of first storage units.

2. The magnetic random access memory according to claim 1, characterized in that: The magnetic shielding layer is disposed in contact with the at least one magnetic shielding column.

3. The magnetic random access memory according to claim 1 or 2, characterized in that: A plurality of magnetic shielding columns are arranged at intervals, and each of the magnetic shielding columns has a projection on the magnetic shielding layer.

4. The magnetic random access memory according to claim 1 or 2, characterized in that: The plurality of magnetic shielding columns are arranged at intervals, the projection of each magnetic shielding column on a preset horizontal plane is a first projection, the projection of the magnetic shielding layer on the preset horizontal plane is a second projection, one side of the first projection coincides with one side of the second projection, and the preset horizontal plane is a plane parallel to the first surface.

5. The magnetic random access memory according to claim 4, characterized in that: The shape of the first projection is L-shaped, the number of the first projections is 4, each of the first projections has a first side and a second side away from the storage array, and the extension lines of the four first sides and the extension lines of the four second sides form a rectangle.

6. The magnetic random access memory according to claim 1 or 2, characterized in that: The magnetic random access memory includes an array area having the storage array and a logic area adjacent to the array area, wherein the logic area has a bottom metal wiring layer and a conductive path sequentially stacked along the first extension direction, and the magnetic shielding layer is also located on the second side, which is the side of the conductive path away from the bottom metal wiring layer.

7. The magnetic random access memory according to claim 1 or 2, characterized in that: The magnetic shielding column has a top surface and a bottom surface opposite to each other in the first extension direction, and the magnetic random access memory further comprises: A bottom metal wiring layer is located on a side of each second ferromagnetic layer away from the tunneling barrier layer, and a surface of the bottom metal wiring layer away from the second ferromagnetic layer is a third surface, a distance between the top surface and the third surface is a first distance, a distance between the bottom surface and the first surface is a second distance, the first distance is equal to the second distance, and the first distance is greater than the first height.

8. The magnetic random access memory according to claim 1 or 2, characterized in that: The magnetic shielding column has a top surface and a bottom surface opposite to each other in the first extension direction, and the magnetic random access memory further comprises: A top metal wiring layer is located between the magnetic shielding layer and each of the first ferromagnetic layers, and the surface of the top metal wiring layer away from the first ferromagnetic layer is a fourth surface, the distance between the top surface and the fourth surface is a third distance, the distance between the bottom surface and the second surface is a fourth distance, the third distance is equal to the fourth distance, and the third distance is greater than the first height.

9. The magnetic random access memory according to claim 1 or 2, characterized in that: The material of the magnetic shielding structure is soft magnetic material.

10. The magnetic random access memory according to claim 7, characterized in that: The material of the magnetic shielding layer is an insulating soft magnetic material, and the material of the at least one magnetic shielding column is a metallic soft magnetic material.

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