A method and equipment for manufacturing a TMR sensor device

Abstract

This invention relates to the field of magnetic memory, and particularly to a method and apparatus for manufacturing a TMR sensor. The method involves placing a metal layer photomask in the correct position and using this photomask to create a bottom metal layer connected to a bottom pad. An MTJ element layer is then placed on the bottom metal layer. A top metal layer, connected to a top pad, is then created on the MTJ element layer using a reverse-positioned metal layer photomask, resulting in a device precursor. Connection windows are then created on the top and bottom pads of the device precursor to obtain the TMR sensor. This invention designs the patterns of the top and bottom metal layers to be identical but inverted. Using only one metal layer photomask, the top and bottom metal layers can be set at different rotation positions, reducing production costs and improving production efficiency.

Description

Technical Field

[0001] This invention relates to the field of magnetic memory, and in particular to a method and equipment for manufacturing a TMR sensor. Background Technology

[0002] TMR (tunneling magnetoresistance) sensors, as an emerging type of sensor, are widely used in consumer electronics, industrial electronics, and other fields. This sensor utilizes the tunneling magnetoresistance effect of a magnetic multilayer film to detect external magnetic fields. This is mainly manifested in the fact that the resistance of the magnetic multilayer film changes with the magnitude and angle of the magnetic field. Compared to the widely used Hall effect and AMR (anisotropic magnetoresistance) sensors, it has advantages such as high sensitivity, small size, low power consumption, and high resolution.

[0003] When developing TMR sensor devices, it is usually necessary to design single MTJs, multiple MTJs connected in series and parallel, as well as bridge circuit test structures to characterize and test the performance of MTJ thin films and devices.

[0004] A common TMR sensor MTT series structure consists of a top metal layer (TE), an MTT, and a bottom metal layer (BE) from top to bottom (e.g., Figure 1 The connection method is PAD→TE→MTJ→BE→MTJ→TE→…MTJ→BE→PAD. Among them, TE and BE are usually made of metal materials with low resistivity, which are used as connecting wires to connect the various MTJs in series and to the end pads (PADs). The sensor performance is measured by means of pins, bonding and other methods.

[0005] Currently, due to the increasingly complex structure of TMR sensors, the patterns of the top metal layer TE and the bottom metal layer BE are also becoming more complex. In actual production, this leads to increased production costs and reduced production efficiency for TMR sensor devices.

[0006] Therefore, how to simplify the production process and reduce production costs in the TMR production process is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0007] The purpose of this invention is to provide a method and equipment for manufacturing TMR sensor devices, so as to solve the problems of high production cost and complex process leading to low production efficiency of TMR sensor devices in the prior art.

[0008] To solve the above-mentioned technical problems, the present invention provides a method for manufacturing a TMR sensor device, comprising:

[0009] The metal layer photomask is positioned correctly, and a bottom metal layer connected to the bottom pad is fabricated using the correctly positioned metal layer photomask; the metal layer photomask includes multiple metal light-shielding units, and after photolithography etching, the metal light-shielding units are used to obtain the corresponding metal connection units on the metal layer;

[0010] An MTJ component layer is disposed on the bottom metal layer;

[0011] A top metal layer connected to the top pad is fabricated on the MTJ element layer using a reverse-positioned metal layer photomask to obtain the device precursor; the reverse position is the position of the metal photomask layer obtained by rotating the upright position by 180 degrees; the metal connection unit corresponding to the MTJ unit in the MTJ element layer in the top metal layer is misaligned with the metal connection unit corresponding to the bottom metal layer.

[0012] A connection window is opened on the top and bottom pads of the device precursor to obtain a TMR sensor device.

[0013] Optionally, in the method for producing the TMR sensor device, the step of opening connection windows on the top and bottom pads of the device precursor to obtain the TMR sensor device includes:

[0014] A protective dielectric layer is backfilled into the device precursor, the protective dielectric layer fills the voids in the top metal layer, and covers the bottom liner and the top liner;

[0015] A connecting window is made in the top liner and the bottom liner to penetrate the backfill protective layer, thus obtaining the TMR sensor device.

[0016] Optionally, in the method for manufacturing the TMR sensor, the step of opening a connection window penetrating the backfill protective layer on the top liner and the bottom liner includes:

[0017] A connection window penetrating the backfill protective layer is created on the top and bottom pads by photolithography etching.

[0018] Optionally, in the method for manufacturing the TMR sensor, the protective dielectric layer includes at least one of a silicon dioxide layer and a silicon nitride layer.

[0019] Optionally, in the manufacturing method of the TMR sensor device, the metal photomask includes only one strip-shaped metal light-shielding unit, one end of the metal connecting unit corresponding to the metal light-shielding unit is connected to the corresponding pad, and the other end is connected to the MTJ unit.

[0020] Optionally, in the method for manufacturing the TMR sensor device, the metal layer photomask includes an array region, a bridging region, and an electrical connection region;

[0021] The array area includes multiple metal light-shielding units arranged in an array, and the metal connecting units corresponding to the metal light-shielding units in the same row of the array area are connected in series with the corresponding MTJ units.

[0022] The bridging area is located on the first side of the array area, and the first side is perpendicular to the line connecting the bottom pad and the top pad.

[0023] The individual metal shading unit in the bridging area corresponds to the metal shading units in two adjacent rows in the array area;

[0024] The metal connection unit corresponding to the metal light-shielding unit in the electrical connection area is arranged in contact with the corresponding pad.

[0025] Optionally, in the method for manufacturing the TMR sensor device, the array region includes two rows of the metal light-shielding units;

[0026] The bridging area and the electrical connection area are integrally formed as a single piece of metal light-shielding unit.

[0027] Optionally, in the method for manufacturing the TMR sensor, the TMR sensor includes two top pads and two bottom pads;

[0028] The bottom pad and the top pad are respectively set to correspond to the four sides of the rectangular preset area, wherein two top pads correspond to one set of adjacent edges, and two bottom pads correspond to another set of adjacent edges;

[0029] The metal layer photomask is disposed within the rectangular preset area, and one row of the metal light-shielding units further includes a secondary pad connection area;

[0030] The secondary pad connection area is a single piece of metal light-shielding unit that is integrally formed, and the corresponding metal connection unit is set to contact the nearest pad.

[0031] A manufacturing apparatus for a TMR sensor device, the manufacturing apparatus for performing a manufacturing method for a TMR sensor device as described in any of the above descriptions;

[0032] The manufacturing equipment for the TMR sensor includes a photomask manipulation assembly for displacing and rotating the metal layer photomask.

[0033] Optionally, in the TMR sensor manufacturing equipment, the photomask operation assembly includes at least one of a robotic arm and a conveyor belt.

[0034] The present invention provides a method for manufacturing a TMR sensor device by placing a metal layer photomask in the correct position and fabricating a bottom metal layer connected to a bottom pad using the correct metal layer photomask; the metal layer photomask includes multiple metal light-shielding units, which are etched by photolithography to obtain corresponding metal connection units on the metal layer; an MTJ element layer is disposed on the bottom metal layer; a top metal layer connected to a top pad is fabricated on the MTJ element layer using a reverse-positioned metal layer photomask, resulting in a device precursor; the reverse-position refers to the position of the metal photomask layer obtained by rotating the correct position by 180 degrees; the metal connection units corresponding to the MTJ units in the MTJ element layer in the top metal layer are misaligned with the corresponding metal connection units in the bottom metal layer; connection windows are opened on the top and bottom pads of the device precursor to obtain the TMR sensor device.

[0035] This invention designs the patterns of the top and bottom metal layers to be identical but inverted, i.e., rotated and reversed images. This allows for the use of only one metal layer photomask, with different rotation positions for both the top and bottom metal layers, significantly reducing the number of photomasks required and thus lowering production costs. Furthermore, it eliminates the need to replace different metal layer photomasks during the production of the TMR sensor, simplifying the production process and further improving efficiency. This invention also provides a production device for a TMR sensor with the aforementioned advantages. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the structure of a common TMR sensor in the prior art;

[0038] Figure 2 A flowchart illustrating a specific embodiment of the manufacturing method for the TMR sensor device provided by the present invention;

[0039] Figures 3 to 14 This is a process flow diagram of a specific embodiment of the manufacturing method of the TMR sensor device provided by the present invention.

[0040] The figure includes: 110 - bottom metal layer, 120 - bottom pad, 210 - top metal layer, 220 - top pad, 310 - MTJ unit, A - metal connection unit corresponding to the array area, B - metal connection unit corresponding to the bridging area, and C - metal connection unit corresponding to the electrical connection area. Detailed Implementation

[0041] To enable those skilled in the art to better understand the present invention, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] The core of this invention is to provide a method for manufacturing a TMR sensor device, and a flowchart of one specific embodiment is shown below. Figure 2 As shown, this is referred to as Specific Implementation Method One, which includes:

[0043] S101: Position the metal layer photomask in the correct position, and fabricate the bottom metal layer 110 connected to the bottom pad 120 using the correct metal layer photomask; the metal layer photomask includes multiple metal light-shielding units, and after photolithography etching, the metal light-shielding units are used to obtain the corresponding metal connection units on the metal layer.

[0044] S102: An MTJ element layer is disposed on the bottom metal layer 110.

[0045] The MTJ element layer is composed of one or more MTJ units 310, and the MTJ unit 310 sequentially includes a reference layer, a dielectric layer and a free layer.

[0046] S103: A top metal layer 210 connected to the top pad 220 is fabricated on the MTJ element layer by a reverse-positioned metal layer photomask to obtain the device precursor; the reverse position is the position of the metal photomask layer obtained by rotating it 180 degrees in the upright position; the metal connection unit corresponding to the MTJ unit 310 in the top metal layer 210 and the metal connection unit corresponding to the bottom metal layer 110 in the MTJ element layer are misaligned.

[0047] The positive position and the reverse position are two positions of the metal layer photomask. In other words, the metal layer photomask in the positive position and the metal layer photomask in the reverse position are symmetrical about a certain point in space, which may be about the center point of the metal layer photomask. In this case, the bottom metal layer 110 and the top metal layer 210 are in the same position, but have undergone a 180-degree rotation. Of course, the symmetrical point may not be the center point of the metal layer photomask. In this case, after setting the bottom metal layer 110, setting the top metal layer 210 not only requires a 180-degree rotation, but also a displacement in a certain direction.

[0048] S104: A connection window is opened on the top pad 220 and the bottom pad 120 of the device precursor to obtain a TMR sensor device.

[0049] Furthermore, this step includes:

[0050] A1: The device precursor is backfilled with a protective dielectric layer, which fills the voids in the top metal layer 210 and covers the bottom pad 120 and the top pad 220.

[0051] The surface of the device precursor is a patterned top metal layer 210. The backfill protective medium fills the spaces between the separated metal connection units of the top metal layer 210. In this preferred embodiment, the protective medium layer can fill the gaps in the device precursor, making the structure of the device precursor more stable and avoiding unintended electrical connections. Furthermore, after the MTJ element layer is completed, the same material as the protective medium layer can still be filled between the MTJ element layers to ensure that the gaps between the individual MTJ units 310 in the MTJ element layer are filled.

[0052] A2: A connection window is made on the top liner 220 and the bottom liner 120 to penetrate the backfill protection layer, thereby obtaining a TMR sensor device.

[0053] Since the protective dielectric layer was covered on the surface of the device precursor in the aforementioned steps, the surfaces of the top pad 220 and the bottom pad 120 are also covered with the protective dielectric layer. In this step, part or all of the insulating protective dielectric layer on the surfaces of the two pads is removed to open the connection window, which facilitates subsequent pin piercing or encapsulation bonding tests.

[0054] Furthermore, the provision of a connection window penetrating the backfill protective layer on the top pad 220 and the bottom pad 120 includes:

[0055] A connection window penetrating the backfill protective layer is formed on the top liner 220 and the bottom liner 120 by photolithography etching.

[0056] In this preferred embodiment, the connection window is further defined as a window opened by a photolithography etching process. The photolithography etching process can remove the protective dielectric layer covering the patterned partial area of ​​the top pad 220 and the bottom pad 120, thereby achieving a very precise connection window opening to meet the needs of various application scenarios.

[0057] The protective dielectric layer includes at least one of a silicon dioxide layer and a silicon nitride layer. The silicon dioxide and silicon nitride have good insulation properties, are dense and stable, and have strong adhesion to TMR devices. Of course, other materials can also be used as the protective dielectric layer, and the choice can be made according to the actual situation; this application does not impose any limitations on this.

[0058] In one specific embodiment, the metal photomask includes only one strip-shaped metal light-shielding unit, one end of which is connected to the corresponding pad and the other end is connected to the MTJ unit 310.

[0059] For reference Figures 3 to 5 ,in Figure 3 , Figure 4 This is a schematic diagram of the structure of the top metal layer 210 and the bottom metal layer 110. Figure 5 This is a schematic diagram of the structure after the top metal layer 210 and the bottom metal layer 110 are stacked. In this specific embodiment, the TMR sensor is simply connected. The top metal layer 210 and the bottom metal layer 110 are strip-shaped metal layers. By rotating them 180 degrees, the bottom metal layer 110 and the top metal layer 210 are connected to the MTJ element layer in different directions. This specific embodiment can be considered as a test structure for a single MTJ unit 310.

[0060] In another specific embodiment, the metal layer photomask includes an array region, a bridging region, and an electrical connection region;

[0061] The array area includes multiple array-arranged metal light-shielding units, and the metal connecting units corresponding to the metal light-shielding units in the same row of the array area are connected in series with the corresponding MTJ units 310.

[0062] The bridging area is located on the first side of the array area, and the first side is perpendicular to the line connecting the bottom pad 120 and the top pad 220.

[0063] The individual metal shading unit in the bridging area corresponds to the metal shading units in two adjacent rows in the array area;

[0064] The metal connection unit corresponding to the metal light-shielding unit in the electrical connection area is arranged in contact with the corresponding pad.

[0065] For reference Figures 6 to 8 ,in Figure 6 , Figure 7 This is a schematic diagram of the structure of the top metal layer 210 and the bottom metal layer 110. Figure 8 This is a schematic diagram of the structure after the top metal layer 210 and the bottom metal layer 110 are stacked. The three areas mentioned above are enclosed in dashed boxes in the figure. In this specific embodiment, a series test structure of MTJ unit 310 of a large-scale array can be realized. Figure 7 The structure in the text shows that Figure 7 The structure described is a series connection test of the MTJ unit 310. Of course, in this specific embodiment, a parallel connection test can also be performed by changing the positional relationship between the bridging region and the electrical connection region. Furthermore, in the accompanying drawings of this invention, the area corresponding to the metal connection unit of the metal light-shielding unit in the array region is outlined with a dashed line and marked A; the area corresponding to the metal connection unit of the metal light-shielding unit in the bridging region is outlined with a dashed line and marked B; and the area corresponding to the metal connection unit of the metal light-shielding unit in the electrical connection region is outlined with a dashed line and marked C.

[0066] As another specific implementation, the array region includes two rows of the metal light-shielding units;

[0067] The bridging area and the electrical connection area are integrally formed as a single piece of metal light-shielding unit.

[0068] For reference Figures 9 to 11 ,in Figure 9 , Figure 10 This is a schematic diagram of the structure of the top metal layer 210 and the bottom metal layer 110. Figure 11 This is a schematic diagram of the structure after the top metal layer 210 and the bottom metal layer 110 are stacked. This specific embodiment is a series-parallel test structure of MTJ unit 310, which can be applied to the corresponding MTJ unit 310 test scenario. This specific embodiment further improves the versatility of the present invention.

[0069] In another specific embodiment, the TMR sensor includes two top pads 220 and two bottom pads 120;

[0070] The bottom pad 120 and the top pad 220 are respectively set to correspond to the four sides of the rectangular preset area, wherein two top pads 220 correspond to one set of adjacent edges, and two bottom pads 120 correspond to another set of adjacent edges;

[0071] The metal layer photomask is disposed within the rectangular preset area, and one row of the metal light-shielding units further includes a secondary pad connection area;

[0072] The secondary pad connection area is a single piece of metal light-shielding unit that is integrally formed, and the corresponding metal connection unit is set to contact the nearest pad.

[0073] For reference Figures 12 to 14 ,in Figure 12 , Figure 13 This is a schematic diagram of the structure of the top metal layer 210 and the bottom metal layer 110. Figure 14 This is a schematic diagram of the structure after the top metal layer 210 and the bottom metal layer 110 are stacked. This specific embodiment is a schematic diagram of the structure of the full-bridge TMR sensor, which further improves the versatility of the present invention.

[0074] The present invention provides a method for manufacturing a TMR sensor device by placing a metal layer photomask in the correct position and fabricating a bottom metal layer 110 connected to a bottom pad 120 using the correct-positioned metal layer photomask. The metal layer photomask includes multiple metal light-shielding units, which are etched by photolithography to obtain corresponding metal connection units on the metal layer. An MTJ element layer is disposed on the bottom metal layer 110. A top metal layer 210 connected to a top pad 220 is fabricated on the MTJ element layer using a reverse-positioned metal layer photomask, resulting in a device precursor. The reverse-position refers to the position of the metal photomask layer obtained by rotating the correct position by 180 degrees. The metal connection units corresponding to the MTJ units 310 in the MTJ element layer in the top metal layer 210 are misaligned with the corresponding metal connection units in the bottom metal layer 110. Connection windows are opened on the top pad 220 and the bottom pad 120 of the device precursor to obtain the TMR sensor device. This invention designs the patterns of the top metal layer 210 and the bottom metal layer 110 so that the patterns of the top metal layer 210 and the bottom metal layer 110 are the same, but the orientation is reversed, that is, they are rotated and inverted images of each other. In this way, only one metal layer photomask is needed to set the top metal layer 210 and the bottom metal layer 110 by different rotation positions, which greatly reduces the number of metal layer photomasks that need to be prepared, thereby reducing production costs. At the same time, in the production process of the TMR sensor device, the process of replacing different metal layer photomasks is eliminated, simplifying the production process and further improving production efficiency.

[0075] The present invention also provides a manufacturing apparatus for a TMR sensor device, referred to as Specific Embodiment Two, wherein the manufacturing apparatus for the TMR sensor device is used to perform the manufacturing method of the TMR sensor device as described in any of the above embodiments.

[0076] The manufacturing equipment for the TMR sensor includes a photomask manipulation assembly for displacing and rotating the metal layer photomask.

[0077] The manufacturing equipment for the TMR sensor in this specific embodiment is used to implement the manufacturing method for the TMR sensor described above. Therefore, the technology of the manufacturing equipment for the TMR sensor in this specific embodiment can be compared with the manufacturing method for the TMR sensor described above, and will not be elaborated further here.

[0078] In a preferred embodiment, the photomask manipulation assembly includes at least one of a robotic arm and a conveyor belt. The robotic arm can more flexibly adjust the position of the metal layer photomask and rotate it, while the conveyor belt occupies less space, which is more conducive to the miniaturization of the equipment and improves the integration of the equipment. It can be selected according to actual needs.

[0079] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section.

[0080] It should be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0081] The production method and equipment for the TMR sensor device provided by this invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make several improvements and modifications to this invention without departing from the principles of this invention, and these improvements and modifications also fall within the protection scope of the claims of this invention.

Claims

1. A method for manufacturing a TMR sensor device, characterized in that, include: The metal layer photomask is positioned correctly, and a bottom metal layer connected to the bottom pad is fabricated using the correctly positioned metal layer photomask; the metal layer photomask includes multiple metal light-shielding units, and after photolithography etching, the metal light-shielding units are used to obtain the corresponding metal connection units on the metal layer; An MTJ component layer is disposed on the bottom metal layer; A top metal layer connected to the top pad is fabricated on the MTJ element layer using a reverse-positioned metal layer photomask to obtain the device precursor; the reverse-position is the position of the metal layer photomask obtained by rotating the upright position by 180 degrees; the metal connection unit corresponding to the MTJ unit in the MTJ element layer in the top metal layer is misaligned with the metal connection unit corresponding to the bottom metal layer. A connection window is opened on the top and bottom pads of the device precursor to obtain a TMR sensor device.

2. The method for manufacturing a TMR sensor device as described in claim 1, characterized in that, The TMR sensor device is obtained by opening connection windows on the top and bottom pads of the device precursor. A protective dielectric layer is backfilled into the device precursor, the protective dielectric layer fills the voids in the top metal layer, and covers the bottom liner and the top liner; A connecting window is made in the top liner and the bottom liner to penetrate the backfill protective layer, thus obtaining the TMR sensor device.

3. The method for producing a TMR sensor device as described in claim 2, characterized in that, The method of creating a connection window that penetrates the backfill protective layer on the top liner and the bottom liner includes: A connection window penetrating the backfill protective layer is created on the top and bottom pads by photolithography etching.

4. The method for producing a TMR sensor device as described in claim 2, characterized in that, The protective dielectric layer includes at least one of a silicon dioxide layer and a silicon nitride layer.

5. The method for manufacturing a TMR sensor device as described in claim 1, characterized in that, The metal layer photomask includes only one strip-shaped metal light-shielding unit. One end of the metal connecting unit corresponding to the metal light-shielding unit is connected to the corresponding pad, and the other end is connected to the MTJ unit.

6. The method for manufacturing a TMR sensor device as described in claim 1, characterized in that, The metal layer photomask includes an array region, a bridging region, and an electrical connection region; The array area includes multiple metal light-shielding units arranged in an array, and the metal connecting units corresponding to the metal light-shielding units in the same row of the array area are connected in series with the corresponding MTJ units. The bridging area is located on the first side of the array area, and the first side is perpendicular to the line connecting the bottom pad and the top pad. The individual metal shading unit in the bridging area corresponds to the metal shading units in two adjacent rows in the array area; The metal connection unit corresponding to the metal light-shielding unit in the electrical connection area is arranged in contact with the corresponding pad.

7. The method for manufacturing a TMR sensor device as described in claim 6, characterized in that, The array region includes two rows of the metal light-shielding units; The bridging area and the electrical connection area are integrally formed as a single piece of metal light-shielding unit.

8. The method for manufacturing a TMR sensor device as described in claim 7, characterized in that, The TMR sensor includes two top pads and two bottom pads; The bottom pad and the top pad are respectively set to correspond to the four sides of the rectangular preset area, wherein two top pads correspond to one set of adjacent edges, and two bottom pads correspond to another set of adjacent edges; The metal layer photomask is disposed within the rectangular preset area, and one row of the metal light-shielding units further includes a secondary pad connection area; The secondary pad connection area is a single piece of metal light-shielding unit that is integrally formed, and the corresponding metal connection unit is set to contact the nearest pad.

9. A manufacturing apparatus for a TMR sensor device, characterized in that, The TMR sensor manufacturing equipment is used to perform the TMR sensor manufacturing method as described in any one of claims 1 to 8; The manufacturing equipment for the TMR sensor includes a photomask manipulation assembly for displacing and rotating the metal layer photomask.

10. The manufacturing equipment for the TMR sensor device as described in claim 9, characterized in that, The photomask operation assembly includes at least one of a robotic arm and a conveyor belt.

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