Production method and production equipment of TMR (Total Magnetic Resonance) sensing device

Abstract

The invention relates to the field of magnetic memories, in particular to a production method and production equipment of a TMR sensing device, and the method comprises the steps: placing a metal layer photomask in a normal position, and manufacturing a bottom metal layer connected with a bottom liner through the normal metal layer photomask; an MTJ element layer is arranged on the bottom metal layer; manufacturing a top metal layer connected with a top liner on the MTJ element layer through an inverted metal layer photomask to obtain a device precursor; connecting windows are formed in the top liner and the bottom liner of the device precursor, and the TMR sensing device is obtained. According to the invention, the patterns of the top metal layer and the bottom metal layer are designed, so that the patterns of the top metal layer and the bottom metal layer are the same, but the directions of the patterns are reversed, and the top metal layer and the bottom metal layer are respectively arranged by using only one metal layer photomask through different rotation positions, so that the production cost is reduced, and the production efficiency is improved. And the production efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of magnetic storage, and in particular to a production method and production equipment for a TMR sensor device. Background Art

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

[0003] When developing TMR sensor devices, it is usually necessary to design a single MTJ, multiple MTJs in series and parallel, and a bridge circuit test structure to characterize and test the MTJ film performance and device performance.

[0004] A common TMR sensor MTJ series structure consists of a top metal layer (TE), MTJ and a bottom metal layer (BE) from top to bottom (e.g. Figure 1 ), and 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 each MTJ in series and connect to the pads (PAD) at both ends. The sensor performance is measured by needle piercing, bonding, etc.

[0005] However, at present, as the structure of the TMR sensor becomes more and more complex, the patterns of the top metal layer TE and the bottom metal layer BE also tend to be complex. In actual production, this will lead to an increase in the production cost of the TMR sensor device and a decrease in the production efficiency.

[0006] Therefore, how to simplify the production process in the TMR production process and reduce production costs is an urgent problem to be solved by technical personnel in this field. Summary of the invention

[0007] The purpose of the present invention is to provide a production method and production equipment for a TMR sensor device, so as to solve the problem in the prior art that the production cost of the TMR sensor device is high and the process is relatively complex resulting in low production efficiency.

[0008] In order to solve the above technical problems, the present invention provides a method for producing a TMR sensor device, comprising:

[0009] The metal layer mask is placed in a positive position, and a bottom metal layer connected to the bottom pad is made through the metal layer mask in the positive position; the metal layer mask includes a plurality of metal shading units, and the metal shading units are photoetched to obtain metal connection units on the corresponding metal layer;

[0010] Disposing an MTJ element layer on the bottom metal layer;

[0011] A top metal layer connected to a top pad is produced on the MTJ element layer by a reversed metal layer mask to obtain a device precursor; the reversed position is the position of the metal mask layer obtained by rotating the normal position by 180 degrees; the metal connection unit corresponding to the MTJ unit in the MTJ element layer in the top metal layer is staggered with the metal connection unit corresponding to the bottom metal layer;

[0012] Connecting windows are opened on the top pad and the bottom pad 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 pad and the bottom pad of the device precursor to obtain the TMR sensor device comprises:

[0014] Backfilling the device precursor with a protective dielectric layer, wherein the protective dielectric layer fills the gap in the top metal layer and covers the bottom pad and the top pad;

[0015] A connection window penetrating through the backfill protection layer is opened on the top pad and the bottom pad to obtain a TMR sensor device.

[0016] Optionally, in the method for producing the TMR sensor device, the step of opening connection windows penetrating the backfill protection layer on the top pad and the bottom pad comprises:

[0017] By photolithography and etching, connection windows penetrating the backfill protection layer are opened on the top pad and the bottom pad.

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

[0019] Optionally, in the production method of the TMR sensor device, the metal mask includes only one strip-shaped metal shading unit, and a metal connecting unit corresponding to the metal shading unit is connected to a corresponding pad at one end and connected to the MTJ unit at the other end.

[0020] Optionally, in the production method of the TMR sensor device, the metal layer mask includes an array area, a bridge area and an electrical connection area;

[0021] The array area includes a plurality of metal shading units arranged in an array, and the metal connection units corresponding to the metal shading units in the same row in the array area are connected in series to the corresponding MTJ units;

[0022] The bridge area is located at a first side edge of the array area, and the first side edge is perpendicular to a line connecting the bottom pad and the top pad;

[0023] The single metal shading unit in the bridge 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 producing the TMR sensor device, the array area includes two rows of the metal shading units;

[0026] The bridging area and the electrical connection area are an integrally formed metal shading unit.

[0027] Optionally, in the production method of the TMR sensor device, the TMR sensor device includes two top pads and two bottom pads;

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

[0029] The metal layer mask is arranged in 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 an integrally formed whole metal light shielding unit, and the corresponding metal connection unit is arranged in contact with the closest pad.

[0031] A production device for a TMR sensor device, wherein the production device for a TMR sensor device is used to perform any of the above-mentioned production methods for a TMR sensor device;

[0032] The production equipment of the TMR sensor device includes a mask operation component for displacing and rotating the metal layer mask.

[0033] Optionally, in the production equipment of the TMR sensor device, the mask operation component includes at least one of a robotic arm and a conveyor belt.

[0034] The production method of the TMR sensor device provided by the present invention comprises the following steps: placing a metal layer mask in a positive position, and making a bottom metal layer connected to a bottom pad by using the positive metal layer mask; the metal layer mask comprises a plurality of metal shading units, and the metal shading units are photoetched to obtain metal connection units on the corresponding metal layer; an MTJ element layer is arranged on the bottom metal layer; a top metal layer connected to a top pad is made on the MTJ element layer by using an inverse metal layer mask to obtain a device precursor; the inverse position is the position of the metal mask layer obtained by rotating the positive position by 180 degrees; the metal connection units corresponding to the MTJ units in the MTJ element layer in the top metal layer and the metal connection units corresponding to the bottom metal layer are arranged in a staggered manner; and connection windows are opened on the top pad and the bottom pad of the device precursor to obtain the TMR sensor device.

[0035] The present invention designs the patterns of the top metal layer and the bottom metal layer so that the patterns of the top metal layer and the bottom metal layer are the same but inverted in direction, that is, they are rotated and inverted images of each other. In this way, only one metal layer mask can be used to set the top metal layer and the bottom metal layer respectively through different rotation positions, which greatly reduces the number of metal layer masks that need to be prepared, thereby reducing production costs. At the same time, in the production process of the TMR sensor device, the replacement process of different metal layer masks is eliminated, the production process is simplified, and the production efficiency is further improved. The present invention also provides a production device for a TMR sensor device with the above-mentioned beneficial effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

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

[0038] Figure 2 A schematic flow chart of a specific implementation method of the production method of the TMR sensor device provided by the present invention;

[0039] Figures 3 to 14 A process flow chart of a specific implementation of the method for producing a TMR sensor device provided by the present invention.

[0040] In the figure, it 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 bridge area, C-metal connection unit corresponding to the electrical connection area. DETAILED DESCRIPTION

[0041] In order to enable those skilled in the art to better understand the scheme of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0042] The core of the present invention is to provide a method for producing a TMR sensor device, a flow chart of a specific implementation method thereof is shown as follows: Figure 2 As shown, it is called specific implementation mode 1, including:

[0043] S101: placing the metal layer mask in a correct position, and making a bottom metal layer 110 connected to the bottom pad 120 through the correct metal layer mask; the metal layer mask includes a plurality of metal shading units, and the metal shading units are photoetched to obtain metal connection units on the corresponding metal layer.

[0044] S102 : Disposing an MTJ element layer 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 includes a reference layer, a dielectric layer, and a free layer in sequence.

[0046] S103: A top metal layer 210 connected to the top pad 220 is produced on the MTJ element layer by an inverse metal layer mask to obtain a device precursor; the inverse position is the position of the metal mask layer obtained by rotating the positive position by 180 degrees; the MTJ unit 310 in the MTJ element layer has a corresponding metal connection unit in the top metal layer 210 and a corresponding metal connection unit in the bottom metal layer 110 staggered.

[0047] The positive position and the inverse position are two positions of the metal layer mask. In other words, the metal layer mask at the positive position and the metal layer mask at the inverse position are symmetrical about a certain point in space, and may be symmetrical about the center point of the metal layer mask. At this time, the bottom metal layer 110 and the top metal layer 210 are set in the same position, but have been rotated 180 degrees. Of course, the symmetry point may not be the center point of the metal layer mask. At this time, after setting the bottom metal layer 110, setting the top metal layer 210 not only requires a rotation of 180 degrees, but also requires a displacement in a certain direction.

[0048] S104: opening connection windows 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: backfilling the device precursor with a protective dielectric layer, wherein the protective dielectric layer fills the gaps 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, and the backfill protection medium is filled between the metal connection units separated by the top metal layer 210. In this preferred embodiment, the protective medium layer can be used to fill the gaps in the device precursor, making the structure of the device precursor more stable and avoiding electrical connections outside the design. In addition, 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 MTJ units 310 in the MTJ element layer are filled.

[0052] A2: A connection window penetrating through the backfill protection layer is opened on the top pad 220 and the bottom pad 120 to obtain a TMR sensor device.

[0053] Since the protective dielectric layer is covered on the surface of the device precursor in the previous step, the surface of the top pad 220 and the surface of 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 for subsequent needle insertion or packaging bonding testing.

[0054] Furthermore, the connection windows penetrating the backfill protection layer are opened on the top liner 220 and the bottom liner 120, including:

[0055] By photolithography and etching, connection windows penetrating the backfill protection layer are opened on the top pad 220 and the bottom pad 120 .

[0056] In the present preferred embodiment, the connection window is further defined as a window opened by a photolithography and etching process. The photolithography and 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 usage scenarios.

[0057] The protective dielectric layer includes at least one of a silicon dioxide layer and a silicon nitride layer. The silicon dioxide and the silicon nitride have good insulation performance, are dense and stable in nature, and have strong bonding with the TMR device. Of course, other materials can also be selected as the protective dielectric layer, which can be selected according to actual conditions, and this application does not limit it here.

[0058] In a specific implementation, the metal mask includes only one strip-shaped metal shading unit, and one end of the metal connecting unit corresponding to the metal shading unit 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 is a schematic diagram of the structure of the top metal layer 210 and the bottom metal layer 110, Figure 5 It is a schematic diagram of the structure after the top metal layer 210 and the bottom metal layer 110 are stacked. In this specific implementation, it is a simple connection method of the TMR sensor device. The top metal layer 210 and the bottom metal layer 110 are a strip-shaped metal layer. By rotating 180 degrees, the bottom metal layer 110 and the top metal layer 210 are respectively connected to the MTJ element layer in different directions. This specific implementation can be considered as a test structure of a single MTJ unit 310.

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

[0061] The array region includes a plurality of metal shading units arranged in an array, and the metal connection units corresponding to the metal shading units in the same row in the array region are connected in series to the corresponding MTJ units 310;

[0062] The bridge area is located at a first side edge of the array area, and the first side edge is perpendicular to a line connecting the bottom pad 120 and the top pad 220;

[0063] The single metal shading unit in the bridge 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 is a schematic diagram of the structure of the top metal layer 210 and the bottom metal layer 110, Figure 8 2 is a schematic diagram of the structure after the top metal layer 210 and the bottom metal layer 110 are stacked. In the figure, the three regions are framed by dotted lines. In this specific implementation, a series test structure of the MTJ unit 310 of a large-scale array can be realized. Figure 7 It can be seen from the structure that Figure 7 The structure in the figure is a series test of the MTJ unit 310. Of course, this specific embodiment can also perform a parallel test by changing the positional relationship between the bridge area and the electrical connection area. In addition, in the drawings of the present invention, the area corresponding to the metal connection unit corresponding to the metal shading unit in the array area is framed by a dotted line and marked A, the area corresponding to the metal connection unit corresponding to the metal shading unit in the bridge area is framed by a dotted line and marked B, and the area corresponding to the metal connection unit corresponding to the metal shading unit in the electrical connection area is framed by a dotted line and marked C.

[0066] As another specific implementation, the array area includes two rows of the metal shading units;

[0067] The bridging area and the electrical connection area are an integrally formed metal shading unit.

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

[0069] As another specific implementation, the TMR sensor device includes two top pads 220 and two bottom pads 120;

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

[0071] The metal layer mask is arranged in 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 an integrally formed whole metal shading unit, and the corresponding metal connection unit is arranged in contact with the closest pad.

[0073] For reference Figure 12 to Figure 14 ,in Fig.12 , Fig.13 is a schematic diagram of the structure of the top metal layer 210 and the bottom metal layer 110, Fig.14 2 is a schematic diagram of the structure after the top metal layer 210 and the bottom metal layer 110 are stacked. This specific implementation is a schematic diagram of the structure of the TMR sensor full-bridge structure, which further improves the versatility of the present invention.

[0074] The production method of the TMR sensor device provided by the present invention comprises the following steps: placing a metal layer mask in a positive position, and making a bottom metal layer 110 connected to a bottom pad 120 through the positive metal layer mask; the metal layer mask comprises a plurality of metal shading units, and the metal shading units are photoetched to obtain metal connection units on the corresponding metal layer; an MTJ element layer is arranged on the bottom metal layer 110; a top metal layer 210 connected to a top pad 220 is made on the MTJ element layer through an inverse metal layer mask to obtain a device precursor; the inverse position is the position of the metal mask layer obtained by rotating the positive 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 staggered with the metal connection units corresponding to the bottom metal layer 110; and connection windows are opened on the top pad 220 and the bottom pad 120 of the device precursor to obtain a TMR sensor device. The present 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 inverted in direction, that is, they are rotated and inverted images of each other. In this way, only one metal layer mask is used, and the top metal layer 210 and the bottom metal layer 110 are respectively set through different rotation positions, which greatly reduces the number of metal layer masks that need to be prepared, thereby reducing production costs. At the same time, in the production process of the TMR sensor device, the replacement process of different metal layer masks is eliminated, which simplifies the production process and further improves production efficiency.

[0075] The present invention also provides a TMR sensor device production device, which is referred to as specific implementation mode 2. The TMR sensor device production device is used to perform any of the above-mentioned TMR sensor device production methods;

[0076] The production equipment of the TMR sensor device includes a mask operation component for displacing and rotating the metal layer mask.

[0077] The production equipment of the TMR sensor device in this specific embodiment is used to implement the production method of the TMR sensor device in the foregoing text. Therefore, the technology of the production equipment of the TMR sensor device in this specific embodiment can be compared with the production method of the TMR sensor device in the foregoing text, and the present invention will not be elaborated here.

[0078] As a preferred embodiment, the mask operation assembly includes at least one of a mechanical arm and a conveyor belt. The mechanical arm can more flexibly adjust the position of the metal layer mask and rotate the metal layer mask, and the conveyor belt occupies less space, which is more conducive to the miniaturization of the equipment and improves the integration of the equipment. The selection can be made according to actual needs.

[0079] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0080] It should be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0081] The above is a detailed introduction to the production method and production equipment of the TMR sensor device provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, the present invention can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A method for producing a TMR sensor device, characterized in that: include: The metal layer mask is placed in a positive position, and a bottom metal layer connected to the bottom pad is made through the metal layer mask in the positive position; the metal layer mask includes a plurality of metal shading units, and the metal shading units are photoetched to obtain metal connection units on the corresponding metal layer; Disposing an MTJ element layer on the bottom metal layer; A top metal layer connected to a top pad is produced on the MTJ element layer by a reversed metal layer mask to obtain a device precursor; the reversed position is the position of the metal mask layer obtained by rotating the normal position by 180 degrees; the metal connection unit corresponding to the MTJ unit in the MTJ element layer in the top metal layer is staggered with the metal connection unit corresponding to the bottom metal layer; Connecting windows are opened on the top pad and the bottom pad of the device precursor to obtain a TMR sensor device.

2. The method for producing a TMR sensor device according to claim 1, wherein: The step of opening a connection window on the top pad and the bottom pad of the device precursor to obtain a TMR sensor device comprises: Backfilling the device precursor with a protective dielectric layer, wherein the protective dielectric layer fills the gap in the top metal layer and covers the bottom pad and the top pad; A connection window penetrating through the backfill protection layer is opened on the top pad and the bottom pad to obtain a TMR sensor device.

3. The method for producing a TMR sensor device according to claim 2, wherein: The connecting window penetrating the backfill protective layer is opened on the top liner and the bottom liner, comprising: By photolithography and etching, connection windows penetrating the backfill protection layer are opened on the top pad and the bottom pad.

4. The method for producing a TMR sensor device according to claim 2, wherein: The protective dielectric layer includes at least one of a silicon dioxide layer and a silicon nitride layer.

5. The method for producing a TMR sensor device according to claim 1, wherein: The metal mask only includes a strip-shaped metal light-shielding unit, and a metal connecting unit corresponding to the metal light-shielding unit is connected to a corresponding pad at one end and connected to the MTJ unit at the other end.

6. The method for producing a TMR sensor device according to claim 1, wherein: The metal layer mask includes an array area, a bridge area and an electrical connection area; The array area includes a plurality of metal shading units arranged in an array, and the metal connection units corresponding to the metal shading units in the same row in the array area are connected in series to the corresponding MTJ units; The bridge area is located at a first side edge of the array area, and the first side edge is perpendicular to a line connecting the bottom pad and the top pad; The single metal shading unit in the bridge 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 producing a TMR sensor device according to claim 6, wherein: The array area includes two rows of metal light-shielding units; The bridging area and the electrical connection area are an integrally formed metal shading unit.

8. The method for producing a TMR sensor device according to claim 7, wherein: The TMR sensor device includes two top pads and two bottom pads; The bottom pad and the top pad are respectively arranged corresponding to the four sides of the rectangular preset area, wherein the two top pads correspond to one set of adjacent sides, and the two bottom pads correspond to the other set of adjacent sides; The metal layer mask is arranged in 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 an integrally formed whole metal light shielding unit, and the corresponding metal connection unit is arranged in contact with the closest pad.

9. A production device for a TMR sensor device, characterized in that: The TMR sensor device production equipment is used to perform the TMR sensor device production method according to any one of claims 1 to 8; The production equipment of the TMR sensor device includes a mask operation component for displacing and rotating the metal layer mask.

10. The production equipment of the TMR sensor device according to 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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