Write head, write head device, write head manufacturing method and magnetizing method

Abstract

The present application relates to a write head, a write head device, a write head manufacturing method and a magnetizing method. The write head comprises: a second wafer, comprising a silicon body, and a first oxide layer and a second oxide layer which are located on the upper surface and the lower surface of the silicon body, respectively; and a magnetic pole array penetrating through the silicon body, and having a magnetic pole writing end located above the second oxide layer and directly facing one Z-bridge arm, and a magnetic pole supporting end surrounded by the first oxide layer, the magnetic pole array being a hard magnetic pole array, and having a magnetic moment in a +Z-direction or a -Z-direction; or the magnetic pole array being a soft magnetic pole array surrounded by a primary coil, and direct current passing through the primary coil and generating a magnetic moment in the +Z-direction or -Z-direction in the soft magnetic pole, wherein during writing, the magnetic pole writing end generates in a pinning layer of the Z-bridge arm a direct-current writing magnetic field comprising a Z-direction component, so that the magnetic moment of the pinning layer turns to the direction of the direct-current writing magnetic field comprising the Z-direction component. The present invention has the advantages of simple structure, high writing efficiency, low price and the like.

Description

A write head, a write head device, a write head manufacturing method, and a magnetizing method Technical Field

[0001] The present application relates to the technical field of magnetic sensors, and in particular to a write head, a write head device, a write head manufacturing method, and a magnetizing method. Background Art

[0002] MTJ magnetic tunnel junction magnetoresistive sensors typically have a push-pull structure, including two push magnetoresistive sensing unit arrays and pull magnetoresistive sensing unit arrays encapsulated in a single chip with opposite magnetic sensitivity directions. For X-axis or Y-axis magnetoresistive sensors, the antiferromagnetic layer magnetic field annealing method is used to determine the magnetic field sensitivity direction of the magnetic tunnel junction. That is, the entire wafer is placed in a magnetic field annealing furnace. All magnetoresistive sensing units on the entire wafer have the same +X magnetic field sensitivity direction. The wafer is then sliced ​​into die. Using the flip-die method, which rotates the +X die, the +Y bridge arm is rotated 90°, the -X bridge arm is rotated 180°, and the -Y bridge arm is rotated 270°, thus obtaining an X-axis push-pull magnetoresistive sensor and a Y-axis push-pull magnetoresistive sensor. However, the biggest problem with this method is that due to the rotation method, there is an error in the relative position arrangement between the die, which affects the accuracy of the sensor.

[0003] To solve this problem, a laser annealing method was proposed. A laser spot is used to heat a single magnetoresistive sensor unit, and magnetic fields in the +X, -X, +Y, -Y, +Z, and -Z directions are applied simultaneously. This allows X, Y, and Z-axis magnetoresistive sensors to be obtained on a single grain, eliminating errors caused by sensor position alignment.

[0004] However, when the laser spot heats the magnetoresistive sensor unit, the laser power needs to be adjusted to ensure that the heating temperature is not too high, thereby causing ablation of the magnetic tunnel junction; on the other hand, the magnetic field generating device acts on the entire wafer range, and a large current needs to be passed through the magnetic field generating device, so the magnetic field generating device needs to be equipped with a cooling device, which has a very high production cost; on the other hand, the laser spot needs to scan all the magnetic tunnel junction units on the wafer one by one, and the scanning time is too long.

[0005] Z-axis magnetoresistive sensors are typically implemented using an X-axis magnetoresistive sensing unit and a flux concentrator. The flux concentrator alters the magnetic circuit so that the Z-magnetic field generates an X-component magnetic field near the X-axis magnetoresistive sensor. However, because the flux concentrator is made of soft magnetic material and electroplated, it inherently exhibits magnetic hysteresis and has uneven thickness distribution. This can affect the repeatability and performance errors of the Z-axis sensor.

[0006] On the other hand, by utilizing the perpendicular anisotropy (PMA) existing at the interface of magnetic transition metal / oxide, such as CoFeB / MgO, a perpendicular anisotropic tunnel junction stack structure of the magnetic metal / oxide / magnetic metal double interface can be formed, and perpendicular anisotropic magnetic material layers are formed on both sides of the oxide. By controlling the oxide magnetic metal and thickness, one side is the reference layer and the other layer is the free layer, and a Z-axis magnetoresistance sensor can be formed.

[0007] Similarly, to form a push-pull Z-axis magnetoresistive sensor, it is necessary to form +Z and -Z axis magnetic tunnel junction arrays in the reference layer in order to obtain both +Z and -Z axis magnetic tunnel junction arrays on one crystal grain.

[0008] A simple, fast, and efficient Z-axis magnetoresistive sensor reference layer magnetic moment writing unit is needed to improve the writing efficiency of the Z-axis magnetoresistive sensor on the wafer.

[0009] Summary of the Invention

[0010] The purpose of this application is to provide a write head, a write head device, a write head manufacturing method and a magnetizing method, which can improve the writing efficiency of a Z-axis magnetoresistive sensor.

[0011] In a first aspect, an embodiment of the present application provides a write head for writing the magnetic moment of the pinned layer of the Z-axis magnetoresistive sensing unit array corresponding to the Z bridge arm on the first wafer of the Z-axis magnetoresistive sensor, wherein the Z bridge arm includes a +Z bridge arm and / or a -Z bridge arm, and the write head and the first soft magnetic shielding layer are respectively located above and below the first wafer; the write head includes: a second wafer including a silicon body and a first oxide layer and a second oxide layer respectively located on the upper surface and the lower surface of the silicon body; and a magnetic pole array penetrating the silicon body, wherein the magnetic pole write end of the magnetic pole array is located above the second oxide layer, and Facing one of the Z bridge arms; the pole support end of the magnetic pole array is surrounded by the first oxide layer; the magnetic pole array is a hard magnetic pole array, and the magnetic moment of the hard magnetic pole is in the +Z direction or -Z direction; or, the magnetic pole array is a soft magnetic pole array surrounded by a primary coil, and a DC current passes through the primary coil and generates a +Z direction or -Z direction magnetic moment in the soft magnetic pole; wherein, during writing, the pole writing end generates a DC writing magnetic field containing a Z-direction component in the pinning layer of the Z bridge arm, thereby causing the magnetic moment of the pinning layer to turn to the direction of the DC writing magnetic field of the Z-direction component.

[0012] In one embodiment, a microwave coil array is included, and any microwave coil surrounds at least one magnetic pole; wherein, during writing, a microwave current passes through the microwave coil to generate a microwave magnetic field in the pinned layer of the Z bridge arm.

[0013] In one embodiment, the silicon body is a Si(100)-plane silicon body.

[0014] In one embodiment, the first oxide layer and the second oxide layer are both silicon oxide layers.

[0015] In one embodiment, the cross-section of the magnetic poles in the magnetic pole array is circular or rectangular.

[0016] In one embodiment, the magnetic pole write end is covered by the second oxide layer, or a write air gap surrounded by the second oxide layer is provided at the magnetic pole write end.

[0017] In one embodiment, a primary coil array consisting of the primary coils is located above the first oxide layer.

[0018] In one embodiment, a second soft magnetic shielding layer is further included; the second soft magnetic shielding layer is located above the first oxide layer, the magnetic pole support end of the hard magnetic pole or the magnetic pole support end of the soft magnetic pole and the primary coil.

[0019] In one embodiment, a third soft magnetic shielding layer is further included; the third soft magnetic shielding layer is located below the second oxide layer and surrounds the magnetic pole writing end.

[0020] In one embodiment, it further includes a heating coil array; the heating coil surrounds the magnetic pole writing end and maintains a set gap with the magnetic pole, and any of the magnetic poles is surrounded by a heating coil; the microwave coil surrounds at least one of the magnetic poles and its corresponding heating coil.

[0021] In a second aspect, an embodiment of the present application provides a write head device, comprising: the write head according to the above-mentioned first aspect or any possible implementation manner of the first aspect, and a first soft magnetic shielding layer.

[0022] In a third aspect, an embodiment of the present application provides a method for manufacturing a write head, which is used to manufacture the write head in the first aspect or any possible implementation of the first aspect, including:

[0023] Step 1:

[0024] The method comprises: 1) selecting a second wafer; 2) using a photoresist as a mask to form a SiO2 etching window on the surface of the first oxide layer, and using a photoresist as a protective layer on the surface of the second oxide layer; 3) using BHF to etch the SiO2 to form a Si etching window; 4) removing the photoresist;

[0025] Alternatively, the method includes: 1) selecting a second wafer; 2) using a photoresist as a mask to form a first SiO2 etching window on the surface of the first oxide layer, and forming a second SiO2 etching window on the surface of the second oxide layer; 3) using BHF to etch SiO2 to form a Si etching window on the first oxide layer, and forming a write air gap at the magnetic pole write end on the surface of the second oxide layer; 4) removing the photoresist;

[0026] Step 2:

[0027] The method comprises: using SiO2 as a mask, clamping a second wafer with a fixture, exposing the first oxide layer to a KOH solution, isolating the second oxide layer from the KOH solution, etching Si in an 80°C water bath until the silicon body is penetrated and the second oxide layer is reached, thereby forming a magnetic pole pit;

[0028] Alternatively, the method includes: etching the silicon body using a DRIE technique until the second oxide layer is formed to form a magnetic pole pit;

[0029] Step 3:

[0030] A thick film magnetic pole is prepared by an airflow sputtering method, comprising: 1) sputtering a seed layer on the surface of the first oxide layer and the magnetic pole pit; 2) sputtering a soft magnetic thick film or a hard magnetic thick film by an airflow sputtering method until the magnetic pole pit is filled; 3) using a photoresist as a mask protection layer to protect the magnetic pole layer and form a window for etching the remaining magnetic pole layers; 4) wet etching the excess magnetic pole thick film until the seed layer is exposed; 5) removing the photoresist to obtain a soft magnetic pole array or a hard magnetic pole array filled in the magnetic pole pit;

[0031] Alternatively, the method comprises: 1) sputtering a seed layer on the surface of the first oxide layer and the magnetic pole pit; 2) using a photoresist as a sacrificial layer and adopting an airflow sputtering method to sputter a soft magnetic thick film or a hard magnetic thick film until the magnetic pole pit is filled; 3) removing the photoresist and removing excess magnetic pole thick film to obtain a soft magnetic pole array or a hard magnetic pole array filled in the magnetic pole pit;

[0032] Alternatively, a thick film magnetic pole is prepared by electroplating, comprising: 1) sputtering a seed layer on the surface of the first oxide layer and the magnetic pole pit; 2) electroforming a magnetic pole layer using a photoresist as a mask until the magnetic pole pit is filled; 3) removing the photoresist to obtain a soft magnetic pole array or a hard magnetic pole array filled in the magnetic pole pit;

[0033] Step 4:

[0034] When the magnetic pole array is a hard magnetic pole array, the method includes: 1) sputtering a second soft magnetic shielding layer; 2) sputtering a seed layer on the surface of the second oxide layer; 3) electroforming a third soft magnetic shielding layer, a heating coil, and a microwave coil using a photoresist as a mask; 4) removing the photoresist; and 5) removing the seed layer.

[0035] When the magnetic pole array is a soft magnetic pole array, the method includes: 1) electroforming an original coil using photoresist as a mask; 2) removing the photoresist; 3) removing the seed layer; 4) sputtering an insulating layer on the original coil using photoresist as a sacrificial layer; 5) removing the photoresist and sputtering the seed layer; 6) sputtering a second soft magnetic shielding layer; 7) sputtering a seed layer on the surface of the second oxide layer; 8) electroforming a third soft magnetic shielding layer, a heating coil and a microwave coil using photoresist as a mask; 9) removing the photoresist; and 10) removing the seed layer.

[0036] In a fourth aspect, an embodiment of the present application provides a magnetizing method for magnetizing the hard magnetic pole array in the write head provided in the first aspect or any embodiment of the first aspect, comprising:

[0037] Any hard magnetic pole is connected to the magnetizing magnetic circuit through an upper soft magnetic flux guide plate located above the magnetic pole support end and a lower soft magnetic flux guide plate located below the magnetic pole writing end. Two or more adjacent hard magnetic poles with the same magnetic moment direction are connected in parallel, and two or more adjacent hard magnetic poles with opposite magnetic moment directions are connected in series. The hard magnetic poles are interconnected in series and parallel to form a two-port magnetic circuit, and the two ports of the two-port magnetic circuit are respectively connected to the two ends of the soft magnetic yoke, and together with the soft magnetic yoke, form a closed magnetic circuit. A magnetizing coil is wound on the soft magnetic yoke, and the magnetizing coil generates a magnetizing magnetic field in the soft magnetic yoke, and generates upward and downward magnetizing magnetic fields in the hard magnetic pole with an upward magnetic moment and the hard magnetic pole with a downward magnetic moment respectively through the upper soft magnetic flux guide plate and the lower soft magnetic flux guide plate. The magnetizing coil is connected to a magnetizing power supply.

[0038] In a fifth aspect, an embodiment of the present application provides a magnetizing method for magnetizing the hard magnetic pole array in the write head provided in the first aspect or any embodiment of the first aspect, comprising:

[0039] The pole writing end and the pole supporting end of one or more adjacent hard magnetic poles with the same magnetic moment are respectively located in the middle of the magnetized air gap with two planes of the soft magnetic yoke. The magnetizing coil is wound on the soft magnetic yoke. The magnetizing coil generates a magnetizing magnetic field in the soft magnetic yoke. The magnetizing coil is connected to a magnetizing power supply. The magnetizing yoke moves on the surface of the second wafer to realize the magnetization of all the hard magnetic poles. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0041] FIG1 is a front view of a DC hard magnetic write head of a first structure provided in an embodiment of the present application;

[0042] FIG2 is a front view of a DC hard magnetic write head of a second structure provided in an embodiment of the present application;

[0043] FIG3 is a bottom view of a DC hard magnetic write head of a second structure provided in an embodiment of the present application;

[0044] FIG4 is a top view of a DC hard magnetic write head of a second structure provided in an embodiment of the present application;

[0045] FIG5 is a front view of a DC hard magnetic write head of a third structure provided in an embodiment of the present application;

[0046] FIG6 is a front view of a DC hard magnetic write head of a fourth structure provided in an embodiment of the present application;

[0047] FIG7 is a front view of a DC hard magnetic write head of a fifth structure provided in an embodiment of the present application;

[0048] FIG8 is a bottom view of a DC hard magnetic write head of a fifth structure provided in an embodiment of the present application;

[0049] FIG9 is a front view of a microwave hard magnetic write head of a first structure provided in an embodiment of the present application;

[0050] FIG10 is a bottom view of a microwave hard magnetic write head of a first structure provided in an embodiment of the present application;

[0051] FIG11 is a front view of a microwave hard magnetic write head of a second structure provided in an embodiment of the present application;

[0052] FIG12 is a front view of a microwave hard magnetic write head of a third structure provided in an embodiment of the present application;

[0053] FIG13 is a bottom view of a microwave hard magnetic write head of a third structure provided in an embodiment of the present application;

[0054] FIG14 is a front view of a microwave hard magnetic write head having a fourth structure provided in an embodiment of the present application;

[0055] FIG15 is a bottom view of a microwave hard magnetic write head having a fourth structure provided in an embodiment of the present application;

[0056] FIG16 is a front view of a DC soft magnetic write head of a first structure provided in an embodiment of the present application;

[0057] FIG17 is a front view of a DC soft magnetic write head of a second structure provided in an embodiment of the present application;

[0058] FIG18 is a front view of a DC soft magnetic write head with a third structure provided in an embodiment of the present application;

[0059] FIG19 is a front view of a DC soft magnetic write head of a fourth structure provided in an embodiment of the present application;

[0060] FIG20 is a front view of a microwave soft magnetic write head of a first structure provided in an embodiment of the present application;

[0061] FIG21 is a front view of a microwave soft magnetic write head of a second structure provided in an embodiment of the present application;

[0062] FIG22 is a front view of a microwave soft magnetic write head having a third structure provided in an embodiment of the present application;

[0063] FIG23 is a front view of a microwave soft magnetic write head having a fourth structure provided in an embodiment of the present application;

[0064] FIG24 is a schematic diagram of the first processing step in the method for preparing a write head according to an embodiment of the present application;

[0065] FIG25 is a schematic diagram of an alternative processing step for the first step in the method for preparing a write head according to an embodiment of the present application;

[0066] FIG26 is a schematic diagram of the second step of the method for preparing a write head according to an embodiment of the present application;

[0067] FIG27 is a schematic diagram of an alternative processing scheme for the second step in the method for preparing a write head according to an embodiment of the present application;

[0068] FIG28 is a schematic diagram of another alternative processing step of the second step in the method for preparing a write head according to an embodiment of the present application;

[0069] FIG29 is a schematic diagram of the third step of manufacturing a hard magnetic write head in the method for manufacturing a write head according to an embodiment of the present application;

[0070] FIG30 is a schematic diagram of the third step of manufacturing a soft magnetic write head in the method for manufacturing a write head according to an embodiment of the present application;

[0071] FIG31 is a schematic diagram of the magnetization steps of the first hard magnetic write head magnetization method according to an embodiment of the present application;

[0072] FIG32 is a schematic diagram of the magnetization steps of the second hard magnetic write head magnetization method in an embodiment of the present application. DETAILED DESCRIPTION

[0073] The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings in the embodiments of the present application.

[0074] It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and should not be understood as indicating or implying relative importance.

[0075] First, an embodiment of the present application provides a write head, which is used to write the magnetic moment of the pinned layer of the Z-axis magnetoresistive sensing unit array corresponding to the Z bridge arm on the first wafer of the Z-axis magnetoresistive sensor, wherein the Z bridge arm includes a +Z bridge arm and / or a -Z bridge arm, and the write head and the first soft magnetic shielding layer are respectively located above and below the first wafer.

[0076] The above-mentioned write head includes:

[0077] The second wafer includes a silicon body and a first oxide layer and a second oxide layer respectively located on the upper surface and the lower surface of the silicon body;

[0078] and a magnetic pole array penetrating the silicon body, wherein a magnetic pole writing end of the magnetic pole array is located above the second oxide layer and directly faces a Z bridge arm; a magnetic pole supporting end of the magnetic pole array is surrounded by the first oxide layer; the magnetic pole array is a hard magnetic pole array, and the magnetic moment of the hard magnetic pole is in the +Z direction or the -Z direction; or the magnetic pole array is a soft magnetic pole array surrounded by a primary coil, and a direct current passes through the primary coil and generates a +Z direction or -Z direction magnetic moment in the soft magnetic pole;

[0079] During writing, the magnetic pole writing end generates a DC writing magnetic field including a Z-direction component in the pinned layer of the Z bridge arm, thereby causing the magnetic moment of the pinned layer to turn to the direction of the DC writing magnetic field of the Z-direction component.

[0080] Optionally, the write head may be implemented in a variety of ways, including but not limited to the following:

[0081] Structure 1: The write head is a DC hard magnetic write head, and its structure is shown in FIG1 . The DC hard magnetic write head 1 (11) of the first structure includes:

[0082] The second wafer 2 includes a silicon body 20 and a first oxide layer 21 and a second oxide layer 22 located on the upper and lower surfaces of the silicon body 20 respectively;

[0083] The hard magnetic pole array 3 penetrating the silicon body 20 includes: hard magnetic poles 30 and 31 with magnetic moments in the +Z direction, and hard magnetic poles 32 and 33 with magnetic moments in the -Z direction; the pole writing end 24 of any hard magnetic pole is located on the side of the second oxide layer 22, and the pole supporting end 25 of any hard magnetic pole is located on the side of the first oxide layer 21.

[0084] Among them, the pole writing end 24 of the hard magnetic pole array 3 is facing the Z bridge arm array 6 located on the first wafer 5 in the Z-axis magnetoresistive sensor, such as the pole writing end 24 of the hard magnetic pole 33 is facing the Z bridge arm 63, the pole writing end 24 of the hard magnetic pole 32 is facing the Z bridge arm 62, the pole writing end 24 of the hard magnetic pole 31 is facing the Z bridge arm 61, and the pole writing end 24 of the hard magnetic pole 30 is facing the Z bridge arm 60.

[0085] The first soft magnetic shielding layer 4 is located below the first wafer 5. The first soft magnetic shielding layer 4 is the key to whether the hard magnetic write head can work normally. A magnetic circuit can be formed between the hard magnetic poles 30~33 and the first soft magnetic shielding layer 4, thereby generating a suitable Z write magnetic field in the corresponding Z bridge arms 60~63.

[0086] Structure 2: The write head is a DC hard magnetic write head of another structure, as shown in FIG2 . In the DC hard magnetic write head 1 (12) of the second structure, the magnetic pole write ends 24 of the hard magnetic poles 30 to 33 of the write head 1 (12) are all surrounded by the second oxide layer 22, that is, there is a write air gap 23 on the second oxide layer 22, which can also be called a write window. The advantage of providing the write air gap 23 is that during the write operation, due to the presence of the write air gap 23, it is convenient to align and position the hard magnetic poles 30 to 33 with the Z bridge arms 60 to 63 with the help of an alignment microscope.

[0087] Of course, it is understandable that the aforementioned structure 1 eliminates the SiO2 micromachining required to create an air gap. Although it lacks a write air gap 23, since the second oxide layer 22 is typically several microns thick and transparent, alignment can still be performed using equipment such as an alignment microscope, though careful identification is required. Furthermore, the second oxide layer 22 in structure 1, which lacks a write air gap 23, also serves to protect the magnetic pole write end 24.

[0088] It should be noted that the above structures 1 and 2 are the two most basic implementations of a DC hard magnetic write head. In practical applications, these two structures can be interchangeable. The other structures described below are improvements based on the above structures 1 and 2.

[0089] FIG3 is a bottom view of the second write head structure shown in FIG2 . It can be seen that FIG2 is actually a cross-sectional view of the write head structure in FIG3 taken along the AA direction. Furthermore, it can be understood that, in addition to the hard magnetic poles 30 to 33 shown in FIG2 , there are also hard magnetic poles 30(0) to 33(0) on the second oxide layer 22 in the structure shown in FIG2 .

[0090] FIG4 is a top view of the second write head structure shown in FIG2 . It can be seen that FIG2 is actually a cross-sectional view of the write head structure in FIG4 taken along the BB direction. Furthermore, it can be understood that, in addition to the hard magnetic poles 30 to 33 shown in FIG2 , hard magnetic poles 30(0) to 33(0) are also present on the first oxide layer 21 in the structure shown in FIG2 .

[0091] Since Si etching uses wet etching, there is anisotropy in the etching rate. In the embodiment of the present application, it is assumed that the etching starts from the first oxide layer 21 and etches toward the second oxide layer 22. In this case, the size of the magnetic pole support end 25 will be larger than the size of the magnetic pole writing end 24, and the hard magnetic pole array 3 will have a taper structure. In addition, the hard magnetic pole can also have a rectangular cross-section. The silicon body 20 in the second wafer 2 is usually a Si (100) silicon body.

[0092] Structure 3: The write head is a DC hard magnetic write head of another structure, and its structure is shown in FIG5 . The DC hard magnetic write head 1 (13) of the third structure is improved on the basis of the write head 1 (11) shown in FIG1 (i.e., the above-mentioned structure 1).

[0093] Compared with the write head 1 (11) of the first structure, the DC hard magnetic write head 1 (13) of the third structure further includes: a second soft magnetic shielding layer 7 located above the first oxide layer 21 and the magnetic pole support end 25 of the hard magnetic pole array 3.

[0094] The effect of the second soft magnetic shielding layer 7 is that it helps to enhance the writing magnetic field of the pole writing end 24 of the hard magnetic pole array 3 by forming a closed magnetic circuit at the pole support end 25 of the hard magnetic pole array 3, and at the same time can also shield the external magnetic field interference from the pole support end 25.

[0095] Structure 4: The write head is a DC hard magnetic write head of another structure, and its structure is shown in FIG6 . The DC hard magnetic write head 1 (14) of the fourth structure is improved on the basis of the write head 1 (13) shown in FIG5 (ie, the above-mentioned structure 3).

[0096] Compared with the DC hard magnetic write head 1 (13) of the third structure, the DC hard magnetic write head 1 (14) of the fourth structure further includes: a third soft magnetic shielding layer 9 located below the second oxide layer 22, and the third soft magnetic shielding layer 9 surrounds the magnetic pole write end 24 of the hard magnetic pole array 3, forming a write window 26 on the third soft magnetic shielding layer 9.

[0097] The purpose of setting the third soft magnetic shielding layer 9 is to spatially limit the magnetic field generated by the magnetic pole writing end 24 of the hard magnetic pole array 3, to ensure that the writing magnetic field is only within the spatial range of the corresponding Z bridge arm array, so as not to interfere with the writing operation of the adjacent Z bridge arm, thereby improving the spatial resolution of the writing magnetic field.

[0098] Structure 5: The write head is a DC hard magnetic write head of another structure, and its structure is shown in Figures 7 and 8. The DC hard magnetic write head 1 (15) of the fifth structure is improved on the basis of the write head 1 (14) shown in Figure 6 (i.e., the above-mentioned structure 4).

[0099] FIG8 is a bottom view of the write head structure 5 shown in FIG7 . It can be seen that FIG7 is actually a cross-sectional view of the write head structure in FIG8 taken along the EE direction.

[0100] Compared with the DC hard magnetic write head 1 (14) of the fourth structure, the DC hard magnetic write head 1 (15) of the fifth structure further includes: a heating coil array 100 located below the second oxide layer 22 and surrounding the write window 26, and any hard magnetic pole corresponds to a heating coil. As can be seen from the top view shown in Figure 8, the corresponding relationship between the heating coils and the hard magnetic poles can be: the hard magnetic pole 30 corresponds to the heating coil 10, the hard magnetic pole 30 (0) corresponds to the heating coil 10 (0), the hard magnetic pole 31 corresponds to the heating coil 11, the hard magnetic pole 31 (0) corresponds to the heating coil 11 (0), the hard magnetic pole 32 corresponds to the heating coil 12, the hard magnetic pole 32 (0) corresponds to the heating coil 12 (0), the hard magnetic pole 33 corresponds to the heating coil 13, and the hard magnetic pole 33 (0) corresponds to the heating coil 13 (0).

[0101] In addition, an isolation gap exists between the heating coil array 100 and the third soft magnetic shielding layer 9 .

[0102] The purpose of setting up the heating coil array 100 is to heat and increase the temperature of the Z bridge arm array 6 to the blocking temperature when the hard magnetic write head 1 (15) writes the pinned layer magnetic moment of the Z bridge arm array 6 located on the first wafer 4.

[0103] Structure 6: The write head is a microwave hard magnetic write head, and its structure is shown in Figures 9 and 10. The microwave hard magnetic write head 1 (21) of the first structure is improved on the basis of the DC hard magnetic write head 1 (12) shown in Figure 2 (that is, the above-mentioned structure 2).

[0104] FIG10 is a top view of the microwave hard magnetic write head of the first structure shown in FIG9 . It can be seen that FIG9 is actually a cross-sectional view of the write head structure in FIG10 taken along the CC direction.

[0105] Compared with the DC hard magnetic write head 1 (12) of the second structure (i.e., the above-mentioned structure 2), the microwave hard magnetic write head 1 (21) of the first structure further includes: a microwave coil array 40, and the microwave coil array 40 is located below the second oxide layer 22, and any microwave coil 41 or 42 surrounds at least one hard magnetic pole. For example, as shown in FIG10 , the microwave coil 41 surrounds the hard magnetic poles 30, 31, 30(0), and 31(0), and the microwave coil 42 surrounds the hard magnetic poles 32, 33, 32(0), and 33(0).

[0106] The purpose of setting up the microwave coil array 40 is: the hard magnetic pole array 3 generates a Z-direction DC magnetic field in the Z bridge arm array 6 located on the first wafer 5, assisted by the microwave magnetic field generated by the microwave coil array 40, thereby generating a precession (process) in the magnetic moment of the Z bridge arm, so that the magnetic moment writing process has a stable trajectory.

[0107] Structure seven, the write head is a microwave hard magnetic write head, and its structure is shown in FIG11 . The microwave hard magnetic write head 1 ( 22 ) of the second structure is improved on the basis of the microwave hard magnetic write head 1 ( 21 ) shown in FIG10 (ie, the above-mentioned structure six).

[0108] Compared with the microwave hard magnetic write head 1 (21) of the first structure, the microwave hard magnetic write head 1 (22) of the second structure further includes: a second soft magnetic shielding layer 7 located above the first oxide layer 21 and the magnetic pole support end 25 of the hard magnetic pole array 3.

[0109] Structure 8: The write head is a microwave hard magnetic write head, and its structure is shown in Figures 12 and 13. The microwave hard magnetic write head 1 (23) of the third structure is improved on the basis of the microwave hard magnetic write head 1 (22) shown in Figure 11.

[0110] FIG13 is a bottom view of the microwave hard magnetic write head of the third structure shown in FIG12. It can be seen that FIG12 is actually a cross-sectional view of the write head structure in FIG13 taken along the DD direction.

[0111] Compared with the microwave hard magnetic write head 1 (22) of the second structure (i.e., the above-mentioned structure seven), the microwave hard magnetic write head 1 (23) of the third structure further includes: a third soft magnetic shielding layer 9 located below the second oxide layer 22, and the third soft magnetic shielding layer 9 surrounds the magnetic pole write end 24 of the hard magnetic pole array 3 to produce a write window 26.

[0112] In addition, an isolation gap also exists between the third soft magnetic shielding layer 9 and the microwave coils 41 and 42 for electrical insulation.

[0113] It can be seen from the bottom view shown in Figure 13 that the air gaps between the microwave coil 42 and the hard magnetic poles 32, hard magnetic poles 33, hard magnetic poles 32(0) and hard magnetic poles 33(0) it surrounds, the air gaps between the microwave coil 41 and the hard magnetic poles 30, hard magnetic poles 31, hard magnetic poles 30(0) and hard magnetic poles 31(0) it surrounds, between the microwave coil 41 and the microwave coil 42, and outside the microwave coil 41 and the microwave coil 42, except for the electrical isolation air gap and the isolation air gap, are all covered by the third soft magnetic shielding layer 9.

[0114] Structure 9: The write head is a microwave hard magnetic write head, and its structure is shown in Figures 14 and 15. The microwave hard magnetic write head 1 (24) of the fourth structure is improved on the basis of the microwave hard magnetic write head 1 (23) shown in Figure 12.

[0115] FIG15 is a bottom view of the microwave hard magnetic write head of the fourth structure shown in FIG14 . It can be seen that FIG14 is actually a cross-sectional view of the write head structure in FIG15 taken along the FF direction.

[0116] Compared with the microwave hard magnetic write head 1 (23) of the third structure (i.e., the above-mentioned structure eight), the microwave hard magnetic write head 1 (24) of the fourth structure further includes: a heating coil array 100 located below the second oxide layer 22 and surrounding the writing window 26 of the magnetic pole write end 24 of the hard magnetic pole array 3.

[0117] In addition, there are also isolation gaps between the third soft magnetic shielding layer 9 and the microwave coils 41 and 42, and between the third soft magnetic shielding layer 9 and the heating coil array 100 for electrical insulation. As can be seen from the bottom view shown in FIG15 , except for the electrical isolation gaps, the microwave coil 42 and the heating coils 12, 13, 12(0), and 13(0) surrounded by it are all covered by the third soft magnetic shielding layer 9. The heating coils 12, 13, 12(0), and 13(0) respectively surround the writing windows corresponding to the hard magnetic poles 32, 33, 32(0), and 33(0). The microwave coil 41 and the heating coils 10, 11, 10(0), and 11(0) surrounding it are all covered by the third soft magnetic shielding layer 9, except for the electrical isolation gap. The heating coils 10, 11, 10(0), and 11(0) surround the writing windows corresponding to the hard magnetic poles 30, 31, 30(0), and 31(0), respectively. The microwave coils 41 and 42, as well as the microwave coils 41 and 42, are all covered by the third soft magnetic shielding layer 9, except for the electrical isolation gap and the isolation air gap.

[0118] Structure 10: The write head is a DC soft magnetic write head, and its structure is shown in FIG16 . The DC soft magnetic write head 1 (31) of the first structure includes:

[0119] The second wafer 2 includes a silicon body 20 and a first oxide layer 21 and a second oxide layer 22 located on the upper and lower surfaces of the silicon body 20 respectively;

[0120] a soft magnetic pole array 3 ′ penetrating the second wafer 2 ;

[0121] and a primary coil array 3 ( 0 ) located above the first oxide layer 21 .

[0122] The pole support end 25 of any soft magnetic pole array is surrounded by a primary coil, through which a direct current passes, and by changing the direction of the direct current, a +Z direction magnetic moment or a -Z direction magnetic moment is generated in the corresponding soft magnetic pole, so that a +Z direction or -Z direction writing magnetic field is finally generated in the corresponding Z bridge arm through the soft magnetic pole writing end 24. In the embodiment of the present application, the primary coil 33 surrounds the soft magnetic pole 30', and the primary coil 34 surrounds the soft magnetic pole 31', respectively generating a +Z direction magnetic moment in the Z bridge arms 60 and 61 located on the first wafer 5; the primary coil 35 surrounds the soft magnetic pole 32', and the primary coil 36 surrounds the soft magnetic pole 33', respectively generating a -Z direction magnetic moment in the Z bridge arms 62 and 63.

[0123] The first soft magnetic shielding layer 4 is located below the first wafer 5, ensuring that the primary coil array 3 (0) forms a magnetic circuit between the magnetic field generated by the soft magnetic write head array 3' and the first soft magnetic shielding layer 4, thereby generating a suitable Z write magnetic field in the corresponding Z bridge arm array 6.

[0124] Structure 11: The write head is a DC soft magnetic write head, and its structure is shown in FIG17 . The DC soft magnetic write head 1 ( 32 ) of the second structure is improved based on the DC soft magnetic write head 1 ( 31 ) of the first structure shown in FIG16 .

[0125] The difference between the DC soft magnetic write head 1 (32) of the second structure and the DC soft magnetic write head 1 (31) of the first structure shown in Figure 16 is that a write air gap 23 is provided on the second oxide layer 22 facing the magnetic pole write end 24 of the soft magnetic write head in the DC soft magnetic write head 1 (31) of the first structure, while the DC soft magnetic write head 1 (32) of the second structure does not have a write air gap.

[0126] Structure 12: The write head is a DC soft magnetic write head, and its structure is shown in FIG18 . The DC soft magnetic write head 1 ( 33 ) of the third structure is improved based on the DC soft magnetic write head 1 ( 32 ) of the second structure shown in FIG17 .

[0127] Compared with the DC soft magnetic write head 1 (32) of the second structure, the DC soft magnetic write head 1 (33) of the third structure further adds a second soft magnetic shielding layer 7 above the first oxide layer 21, the original coil array 3 (0) and the magnetic pole support end 25 of the soft magnetic pole array 3', and an insulating electrical isolation layer 8 is also provided to achieve electrical isolation between the original coil array 3 (0) and the second soft magnetic shielding layer 7; in addition, the DC soft magnetic write head 1 (33) of the third structure further adds a third soft magnetic shielding layer 9 below the second oxide layer 22, and the third soft magnetic shielding layer 9 surrounds the magnetic pole write end 24 of the soft magnetic pole array 3' and forms a write window 26.

[0128] It should be pointed out that the above content introduces the situation where the DC soft magnetic write head 1 (33) of the third structure includes both the second soft magnetic shielding layer 7 and the third soft magnetic shielding layer 9. However, when the above DC soft magnetic write head can separately include the second soft magnetic shielding layer 7 or the third soft magnetic shielding layer 9, the function of the DC soft magnetic write head can also be realized.

[0129] In addition, it can be understood that the above improvements can also be made on the basis of the DC soft magnetic write head 1 (31) of the first structure shown in FIG. 16 .

[0130] Structure 13: The write head is a DC soft magnetic write head, and its structure is shown in FIG19 . The DC soft magnetic write head 1 (34) of the fourth structure is improved based on the DC soft magnetic write head 1 (33) of the third structure shown in FIG18 .

[0131] Compared with the DC soft magnetic write head 1 (33) of the third structure, the DC soft magnetic write head 1 (34) of the fourth structure further includes a heating coil array 100, which surrounds the writing window 26 of the magnetic pole writing end 24 of the soft magnetic pole array 3' and forms an electrical insulation gap between the heating coil array 100 and the third soft magnetic shielding layer 9.

[0132] Structure 14: The write head is a microwave soft magnetic write head, and its structure is shown in FIG20 . The microwave soft magnetic write head 1 ( 41 ) of the first structure is improved on the basis of the DC soft magnetic write head 1 ( 31 ) of the first structure shown in FIG16 .

[0133] Compared with the DC soft magnetic write head 1 (31) of the first structure, the microwave soft magnetic write head 1 (41) of the first structure further includes a microwave coil array 40 arranged under the second oxide layer 22, and any microwave coil surrounds at least one soft magnetic pole. For example, the microwave coil 41 in Figure 20 surrounds the soft magnetic pole 30' and the soft magnetic pole 31', and the microwave coil 42 surrounds the soft magnetic pole 32' and the soft magnetic pole 33'.

[0134] Structure 15. The write head is a microwave soft magnetic write head, and its structure is shown in FIG21 . The microwave soft magnetic write head 1 ( 42 ) of the second structure is improved on the basis of the microwave soft magnetic write head 1 ( 41 ) of the first structure shown in FIG20 .

[0135] Compared with the microwave soft magnetic write head 1 (41) of the first structure, the microwave soft magnetic write head 1 (42) of the second structure further includes a second soft magnetic shielding layer 7 arranged above the original coil array 3 (0), the soft magnetic pole array 3' and the second oxide layer 21, and an insulating electrical isolation layer 8 is also arranged between the original coil array 3 (0) and the second soft magnetic shielding layer 7.

[0136] Structure 16: The write head is a microwave soft magnetic write head, and its structure is shown in FIG22 . The microwave soft magnetic write head 1 ( 43 ) of the third structure is improved on the basis of the microwave soft magnetic write head 1 ( 42 ) of the second structure shown in FIG21 .

[0137] Compared with the microwave soft magnetic write head 1 (42) of the second structure, the microwave soft magnetic write head 1 (43) of the third structure further includes a third soft magnetic shielding layer 9 arranged under the second oxide layer 22, and the third soft magnetic shielding layer 9 surrounds the writing window 26 of the magnetic pole writing end 24 of the soft magnetic pole array 3'. In addition, an electrical isolation gap is formed between the third soft magnetic shielding layer 9 and the microwave coil array 40.

[0138] Structure 17: The write head is a microwave soft magnetic write head, and its structure is shown in FIG23 . The microwave soft magnetic write head 1 ( 44 ) of the fourth structure is improved on the basis of the microwave soft magnetic write head 1 ( 43 ) of the third structure shown in FIG22 .

[0139] Compared with the microwave soft magnetic write head 1 (43) of the third structure, the microwave soft magnetic write head 1 (44) of the fourth structure further includes a heating coil array 100, which surrounds the writing window 26 of the magnetic pole writing end 24 of the soft magnetic pole array 3. In addition, an electrical isolation gap is formed between the third soft magnetic shielding layer 9 and the microwave coil array 40 and the heating coil array 100.

[0140] It can be understood that the first oxide layer 21 and the second oxide layer 22 in the above structure can both be silicon oxide layers.

[0141] Based on the same inventive concept, an embodiment of the present application also provides a write head device, which includes any write head introduced in the above content and a first soft magnetic shielding layer. The write head and the first soft magnetic shielding layer 4, and the setting method of the first soft magnetic shielding layer 4 have been described in detail in the above content and will not be repeated here.

[0142] The following is a detailed introduction to the manufacturing method of the write head disclosed in the embodiment of the present application.

[0143] It is understood that, as can be seen from the above description, the write heads in the embodiments of the present application may include different structures, and write heads with different structures may correspond to different preparation methods. Of course, write heads with the same structure may also correspond to different preparation methods. The preparation method of the write head can be adjusted according to the specific structure of the write head and different processing technologies. For example, the write head may include a write air gap or not, in which case it corresponds to different preparation methods.

[0144] The method for preparing the write head may include:

[0145] Step 1:

[0146] The method comprises: 1) selecting a second wafer; 2) using a photoresist as a mask to form a SiO2 etching window on the surface of the first oxide layer, and using a photoresist as a protective layer on the surface of the second oxide layer; 3) using BHF to etch the SiO2 to form a Si etching window; 4) removing the photoresist;

[0147] Alternatively, the method includes: 1) selecting a second wafer; 2) using a photoresist as a mask to form a first SiO2 etching window on the surface of the first oxide layer, and forming a second SiO2 etching window on the surface of the second oxide layer; 3) using BHF to etch SiO2 to form a Si etching window on the first oxide layer, and forming a write air gap at the magnetic pole write end on the surface of the second oxide layer; 4) removing the photoresist;

[0148] Step 2:

[0149] The method comprises: using SiO2 as a mask, clamping a second wafer with a fixture, exposing the first oxide layer to a KOH solution, isolating the second oxide layer from the KOH solution, etching Si in an 80°C water bath until the silicon body is penetrated and the second oxide layer is reached, thereby forming a magnetic pole pit;

[0150] Alternatively, the method includes: etching the silicon body using a DRIE technique until the second oxide layer is formed to form a magnetic pole pit;

[0151] Step 3:

[0152] A thick film magnetic pole is prepared by an airflow sputtering method, comprising: 1) sputtering a seed layer on the surface of the first oxide layer and the magnetic pole pit; 2) sputtering a soft magnetic thick film or a hard magnetic thick film by an airflow sputtering method until the magnetic pole pit is filled; 3) using a photoresist as a mask protection layer to protect the magnetic pole layer and form a window for etching the remaining magnetic pole layers; 4) wet etching the excess magnetic pole thick film until the seed layer is exposed; 5) removing the photoresist to obtain a soft magnetic pole array or a hard magnetic pole array filled in the magnetic pole pit;

[0153] Alternatively, the method comprises: 1) sputtering a seed layer on the surface of the first oxide layer and the magnetic pole pit; 2) using a photoresist as a sacrificial layer and adopting an airflow sputtering method to sputter a soft magnetic thick film or a hard magnetic thick film until the magnetic pole pit is filled; 3) removing the photoresist and removing excess magnetic pole thick film to obtain a soft magnetic pole array or a hard magnetic pole array filled in the magnetic pole pit;

[0154] Alternatively, a thick film magnetic pole is prepared by electroplating, comprising: 1) sputtering a seed layer on the surface of the first oxide layer and the magnetic pole pit; 2) electroforming a magnetic pole layer using a photoresist as a mask until the magnetic pole pit is filled; 3) removing the photoresist to obtain a soft magnetic pole array or a hard magnetic pole array filled in the magnetic pole pit;

[0155] Step 4:

[0156] When the magnetic pole array is a hard magnetic pole array, the method includes: 1) sputtering a second soft magnetic shielding layer; 2) sputtering a seed layer on the surface of the second oxide layer; 3) electroforming a third soft magnetic shielding layer, a heating coil, and a microwave coil using a photoresist as a mask; 4) removing the photoresist; and 5) removing the seed layer.

[0157] When the magnetic pole array is a soft magnetic pole array, the method includes: 1) electroforming an original coil using photoresist as a mask; 2) removing the photoresist; 3) removing the seed layer; 4) sputtering an insulating layer on the original coil using photoresist as a sacrificial layer; 5) removing the photoresist and sputtering the seed layer; 6) sputtering a second soft magnetic shielding layer; 7) sputtering a seed layer on the surface of the second oxide layer; 8) electroforming a third soft magnetic shielding layer, a heating coil and a microwave coil using photoresist as a mask; 9) removing the photoresist; and 10) removing the seed layer.

[0158] The following diagrams illustrate some methods for manufacturing a write head. The methods for manufacturing a write head include but are not limited to the following methods:

[0159] The first step is to process magnetic pole pits on the second wafer 2, as shown in FIG24 , including:

[0160] (a) selecting a second wafer 2 comprising a silicon body 20, a first oxide layer 21 and a second oxide layer 22;

[0161] (b) In the first oxide layer 21, a photoresist 70 is used as a mask to form a SiO2 etching window 71;

[0162] On the surface of the second oxide layer 22, a photoresist 70 (1) is used as a protective layer;

[0163] (c) Using BHF (buffered HF) to etch SiO2 to form a Si etching window;

[0164] (d) removing the photoresist;

[0165] (e) Using SiO2 as a mask, Si is etched in a KOH water bath until reaching the second oxide layer 22 to obtain the write head pit 73.

[0166] The steps shown in FIG. 25 are an alternative to the first step (i.e., machining magnetic pole pits on the second wafer 2) in the method for manufacturing a write head, and include:

[0167] (a) selecting a second wafer 2 comprising a silicon body 20, a first oxide layer 21 and a second oxide layer 22;

[0168] (b) using a photoresist 70 as a mask, forming a SiO2 etching window 71 on the surface of the first oxide layer 21, and forming a SiO2 etching window 71(0) on the surface of the second oxide layer 22;

[0169] (c) using BHF (buffered HF) to etch SiO2, forming a Si etching window 72 on the surface of the first oxide layer 21, and forming a write air gap 72 (0) on the SiO2 on the surface of the second oxide layer 22;

[0170] (d) removing the photoresist;

[0171] (e) Using SiO2 as a mask and a fixture, only the first oxide layer 21 is exposed in a KOH bath, and Si is etched until the wafer is etched through to obtain a write head pit 73 (0).

[0172] Step 2: Obtaining a soft magnetic pole array or a hard magnetic pole array, as shown in FIG26 , including:

[0173] (a) depositing a seed layer 74 to cover the magnetic pole pits and the surface of the first oxide layer;

[0174] (b) depositing a hard magnetic thick film or a soft magnetic thick film 75 until the magnetic pole pits are filled;

[0175] (c) using photoresist as a mask 76 to cover the pole support end, forming an etching window for etching the thick film at other locations;

[0176] (d) wet etching the thick film at the remaining locations 77 until the seed layer is exposed;

[0177] (e) Removing the photoresist to obtain a soft magnetic or hard magnetic pole array filled in the magnetic pole pits.

[0178] The steps shown in FIG. 27 are an alternative solution 1 for the second step (obtaining a soft magnetic pole array or a hard magnetic pole array) in the write head manufacturing method, including:

[0179] (a) depositing a seed layer 74 to cover the magnetic pole pits and the surface of the first oxide layer;

[0180] (b) using photoresist 80 as a sacrificial layer, depositing a hard magnetic thick film or a soft magnetic thick film 81 until the magnetic pole pit is filled;

[0181] (c) Removing the photoresist to obtain a soft magnetic or hard magnetic pole array filled in the magnetic pole pits.

[0182] The steps shown in FIG. 28 are a second alternative to the second step (obtaining a soft magnetic pole array or a hard magnetic pole array) in the write head manufacturing method, including:

[0183] (a) depositing a seed layer 74 to cover the magnetic pole pits and the surface of the first oxide layer;

[0184] (b) using photoresist 80(0) as a mask, electroforming a hard magnetic thick film or a soft magnetic thick film 81(0) until the magnetic pole pits are filled;

[0185] (c) Removing the photoresist to obtain a soft magnetic or hard magnetic pole array filled in the magnetic pole pits.

[0186] Step 3: Different processes are performed on the hard magnetic write head and the soft magnetic write head in the third step. FIG. 29 shows the third step in the manufacturing method of the hard magnetic write head, including:

[0187] (a) depositing a second soft magnetic shielding layer 7 to cover the hard magnetic pole support end and the first oxide layer;

[0188] (b) depositing a seed layer 90 on the surface of the second oxide layer;

[0189] (c) using a photoresist as a mask, electroforming a heating coil 70, a microwave coil 14, and a third soft magnetic shielding layer 9 on the seed layer;

[0190] (d) removing the photoresist;

[0191] (e) Remove the seed layer.

[0192] The steps shown in FIG30 are the third step in the method for manufacturing a soft magnetic write head, including:

[0193] (a) Electroforming the primary coil array 31-34 using photoresist 82 as a mask;

[0194] (b) removing the photoresist;

[0195] (c) removing the seed layer;

[0196] (d) Using photoresist 83 as a sacrificial layer, an insulating layer 8 is deposited to cover the primary coil array;

[0197] (e) removing the photoresist and sputtering the seed layer 84;

[0198] (f) depositing a second soft magnetic shielding layer 7;

[0199] (g) depositing a seed layer 85 on the surface of the second oxide layer;

[0200] (h) Using the photoresist 86 as a mask, electroforming the heating coil 11, the microwave coil 41 and the third soft magnetic shielding layer 9;

[0201] (i) removing photoresist;

[0202] (j) Remove the seed layer.

[0203] It should be pointed out that the third step of the hard magnetic write head and soft magnetic write head shown in Figures 29 and 30 includes all elements, including the required items such as the hard magnetic pole array, or one of the soft magnetic pole array and the original coil array, as well as the alternative items such as the second soft magnetic shielding layer, the third soft magnetic shielding layer, the heating coil, the microwave coil, etc. The alternative items can be unselected, or one, two, three, or all of them can be selected.

[0204] Since the hard magnetic pole array of the hard magnetic write head needs to be magnetized to write the required magnetic moment after being formed by micromachining technology, the embodiments of the present application provide two magnetization methods. Among them, the first magnetization method is used to magnetize the hard magnetic pole array in any of the above-mentioned write heads, including:

[0205] Any hard magnetic pole is connected to the magnetizing magnetic circuit through an upper soft magnetic flux guide plate located above the magnetic pole support end and a lower soft magnetic flux guide plate located below the magnetic pole writing end. Two or more adjacent hard magnetic poles with the same magnetic moment direction are connected in parallel, and two or more adjacent hard magnetic poles with opposite magnetic moment directions are connected in series. The hard magnetic poles are interconnected in series and parallel to form a two-port magnetic circuit, and the two ports of the two-port magnetic circuit are respectively connected to the two ends of the soft magnetic yoke, and together with the soft magnetic yoke, form a closed magnetic circuit. A magnetizing coil is wound on the soft magnetic yoke, and the magnetizing coil generates a magnetizing magnetic field in the soft magnetic yoke, and generates upward and downward magnetizing magnetic fields in the hard magnetic pole with an upward magnetic moment and the hard magnetic pole with a downward magnetic moment respectively through the upper soft magnetic flux guide plate and the lower soft magnetic flux guide plate. The magnetizing coil is connected to a magnetizing power supply.

[0206] A second magnetizing method, for magnetizing the hard magnetic pole array in any of the above-mentioned write heads, comprises:

[0207] The pole writing end and the pole supporting end of one or more adjacent hard magnetic poles with the same magnetic moment are respectively located in the middle of the magnetized air gap with two planes of the soft magnetic yoke. The magnetizing coil is wound on the soft magnetic yoke. The magnetizing coil generates a magnetizing magnetic field in the soft magnetic yoke. The magnetizing coil is connected to a magnetizing power supply. The magnetizing yoke moves on the surface of the second wafer to realize the magnetization of all the hard magnetic poles.

[0208] The following diagrams provide a detailed introduction to the two magnetization methods mentioned above:

[0209] The steps shown in FIG31 are steps corresponding to the first magnetization method described above. As shown in FIG31(a), the support end and the writing end of any hard magnetic pole 30 are connected to an upper flux guide 201(0) and a lower flux guide 202(0) respectively. As shown in FIG31(b), two or more hard magnetic poles with the same magnetic moment orientation, such as 30 and 31, which are adjacent in space, are connected in parallel, and are connected in parallel here by an upper flux guide 201(1) and a lower flux guide 202(1). As shown in FIG31(c), two adjacent hard magnetic moments with opposite magnetic moment orientations, such as 31 and 32, are connected in series, such as by a lower flux guide 202(2), an upper flux guide 201(2) and a lower flux guide 202(3), and an upper flux guide can only be connected to an upper flux guide, and a lower flux guide can only be connected to a lower flux guide. As shown in FIG31( d ), all or part of the hard magnetic pole array located on the second wafer 2, including hard magnetic poles with upward magnetic moment such as 30, 31, 34 and 35, and hard magnetic poles with downward magnetic moment such as 32, 33, 36 and 37, are interconnected in series and parallel form, such as an upper flux guide 201, a lower flux guide 202 and an upper flux guide 203 to form a two-port structure, and then connected to the two ends 200(0) and 200(1) of a soft magnetic flux yoke 200 to form a closed magnetic circuit structure. A magnetizing coil 300 is wound around the soft magnetic flux yoke 200 to generate a magnetic field in the soft magnetic flux yoke 200. An upward magnetic field is generated in all hard magnetic poles 30, 31, 34 and 35 with upward magnetic moment, and a downward magnetic field is generated in all hard magnetic poles with downward magnetic moment such as 32, 33, 36 and 37, thereby completing magnetization. The magnetizing coil 300 is connected to a power supply of the magnetizer.

[0210] The steps shown in FIG32 are steps corresponding to the second magnetizing method described above. The hard magnetic pole array on the second wafer 2 includes hard magnetic poles 30 and 31 with upward magnetic moment, and hard magnetic poles 34 and 35 with downward magnetic moment. At least one hard magnetic pole with the same magnetic moment orientation, such as 30 and 31, is placed in the magnetizing air gap formed by the two ends 301(0) and 301(1) of the soft magnetic magnetizing yoke 210. A magnetizing coil 301 is wound around the soft magnetic magnetizing yoke. The two ends of the magnetizing coil 301 are connected to each other. The end is connected to a magnetizing power supply to generate a magnetizing magnetic field in the soft magnetic magnetizing yoke 210 and a magnetizing magnetic field in the hard magnetic pole, completing the magnetizing process of the upward magnetic moment hard magnetic poles 30 and 31, and then moves along the surface 302 of the second wafer 2 to the next hard magnetic poles 32 and 33 with a downward magnetic moment, and realizes the change of the magnetizing magnetic field direction by changing the current direction in the magnetizing coil 301, completing the magnetization of the hard magnetic poles 32 and 33, until the magnetization of all hard magnetic poles on the entire second wafer 2 is completed.

[0211] The foregoing description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are readily apparent to those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A write head, characterized in that, Writing the pinned layer magnetic moment of the Z-axis magnetoresistive sensing unit array corresponding to the Z-bridge arm on the first wafer for the Z-axis magnetoresistive sensor, where the Z-bridge arm includes a +Z bridge arm and / or a -Z bridge arm, and the write head and the first soft magnetic shielding layer are respectively located above and below the first wafer; the write head includes: A second wafer, including a silicon body and a first oxide layer and a second oxide layer respectively located on the upper surface and the lower surface of the silicon body; And a magnetic pole array penetrating the silicon body, where the magnetic pole writing end of the magnetic pole array is located above the second oxide layer and faces one of the Z-bridge arms; the magnetic pole supporting end of the magnetic pole array is surrounded by the first oxide layer; the magnetic pole array is a hard magnetic pole array, and the magnetic moment of the hard magnetic pole is in the +Z direction or the -Z direction; or, the magnetic pole array is a soft magnetic pole array surrounded by a primary coil, and a direct current passes through the primary coil to generate a magnetic moment in the +Z direction or the -Z direction in the soft magnetic pole; Wherein, during writing, the magnetic pole writing end generates a direct current writing magnetic field including a Z-direction component in the pinned layer of the Z-bridge arm, so that the pinned layer magnetic moment turns to the direction of the direct current writing magnetic field of the Z-direction component.

2. The write head according to claim 1, wherein It further includes a microwave coil array, and any microwave coil surrounds at least one magnetic pole; wherein, during writing, a microwave current passes through the microwave coil to generate a microwave magnetic field in the pinned layer of the Z-bridge arm.

3. The write head according to claim 1, characterized in that, The silicon body is a Si(100) plane silicon body.

4. The write head according to claim 1, characterized in that, Both the first oxide layer and the second oxide layer are silicon oxide layers.

5. The write head according to claim 1, characterized in that, The cross-section of the magnetic poles in the magnetic pole array is circular or rectangular.

6. The write head according to claim 1, wherein, The magnetic pole writing end is covered by the second oxide layer, or a writing air gap surrounded by the second oxide layer is provided at the magnetic pole writing end.

7. The write head according to claim 1, characterized in that, The primary coil array composed of the primary coils is located above the first oxide layer.

8. The write head according to claim 1 or 2, characterized in that, It further includes a second soft magnetic shielding layer; the second soft magnetic shielding layer is located above the first oxide layer, the magnetic pole supporting end of the hard magnetic pole or the magnetic pole supporting end of the soft magnetic pole, and the primary coils.

9. The write head according to claim 1 or 2, characterized in that, It further includes a third soft magnetic shielding layer; the third soft magnetic shielding layer is located below the second oxide layer and surrounds the magnetic pole writing end.

10. The write head according to claim 2, characterized in that, It further includes a heating coil array; the heating coil surrounds the magnetic pole writing end and maintains a set gap with the magnetic pole, and each magnetic pole is surrounded by one heating coil; the microwave coil surrounds at least one of the magnetic poles and its corresponding heating coil.

11. A write head device, characterized in that, It includes the write head as described in any one of claims 1 to 10 and a first soft magnetic shielding layer.

12. A method for manufacturing a write head, characterized in that, For manufacturing the write head as described in claim 1, the method includes: Step one: Including: 1) Selecting a second wafer; 2) Using photoresist as a mask to form an etching window of SiO2 on the surface of the first oxide layer, and using photoresist as a protective layer on the surface of the second oxide layer; 3) Etching SiO2 with BHF to form a Si etching window; 4) Removing the photoresist; Or, including: 1) Selecting a second wafer; 2) Using photoresist as a mask to form The first etching window of SiO2 is formed on the surface of the second oxide layer to form the second etching window of SiO2; 3) Use BHF to etch SiO2 to form a Si etching window in the first oxide layer and form a write air gap for the magnetic pole writing end on the surface of the second oxide layer; 4) Remove the photoresist; Step 2: It includes: Using SiO2 as a mask, clamping the second wafer with a fixture so that the first oxide layer is exposed to the KOH solution, isolating the second oxide layer from the KOH solution, etching Si in an 80°C water bath until the silicon body is etched through and reaching the second oxide layer to form a magnetic pole pit; Or, it includes: Using DRIE technology to etch the silicon body until the second oxide layer to form a magnetic pole pit; Step 3: Prepare a thick film magnetic pole by gas flow sputtering method, including: 1) Sputter a seed layer on the surface of the first oxide layer and the magnetic pole pit; 2) Use gas flow sputtering method to sputter a soft magnetic thick film or a hard magnetic thick film until the magnetic pole pit is filled; 3) Use photoresist as a mask protection layer to protect the magnetic pole layer and form an etching window for the remaining magnetic pole layers; 4) Wet-etch the excess magnetic pole thick film until the seed layer is exposed; 5) Remove the photoresist to obtain a soft magnetic magnetic pole array or a hard magnetic magnetic pole array filled in the magnetic pole pit; Or, it includes: 1) Sputter a seed layer on the surface of the first oxide layer and the magnetic pole pit; 2) Use photoresist as a sacrificial layer and use gas flow sputtering method to sputter a soft magnetic thick film or a hard magnetic thick film until the magnetic pole pit is filled; 3) Remove the photoresist and remove the excess magnetic pole thick film to obtain a soft magnetic magnetic pole array or a hard magnetic magnetic pole array filled in the magnetic pole pit; Or, prepare a thick film magnetic pole by electroplating method, including: 1) Sputter a seed layer on the surface of the first oxide layer and the magnetic pole pit; 2) Use photoresist as a mask to electroform the magnetic pole layer until the magnetic pole pit is filled; 3) Remove the photoresist to obtain a soft magnetic magnetic pole array or a hard magnetic magnetic pole array filled in the magnetic pole pit; Step 4: When the magnetic pole array is a hard magnetic magnetic pole array, it includes: 1) Sputter a second soft magnetic shielding layer; 2) Sputter a seed layer on the surface of the second oxide layer; 3) Use photoresist as a mask to electroform a third soft magnetic shielding layer, a heating coil and a microwave coil; 4) Remove the photoresist; 5) Remove the seed layer; When the magnetic pole array is a soft magnetic magnetic pole array, it includes: 1) Use photoresist as a mask to electroform the original coil; 2) Remove the photoresist; 3) Remove the seed layer; 4) Use photoresist as a sacrificial layer and sputter an insulating layer on the original coil; 5) Remove the photoresist and sputter a seed layer; 6) Sputter a second soft magnetic shielding layer; 7) Sputter a seed layer on the surface of the second oxide layer; 8) Use photoresist as a mask to electroform a third soft magnetic shielding layer, a heating coil and a microwave coil; 9) Remove the photoresist; 10) Remove the seed layer.

13. A magnetization method, characterized in that, For magnetizing the hard magnetic magnetic pole array in the write head according to any one of claims 1 to 10, the method includes: Any hard magnetic pole is connected to the magnetizing magnetic circuit through an upper soft magnetic flux guiding plate located above the supporting end of the magnetic pole and a lower soft magnetic flux guiding plate located below the writing end of the magnetic pole. Two or more adjacent hard magnetic poles having the same magnetic moment direction are connected in parallel, and two or more adjacent hard magnetic poles having opposite magnetic moment directions are connected in series; the hard magnetic poles are interconnected in series and parallel to form a two-port magnetic circuit, and the two ports of the two-port magnetic circuit are respectively connected to both ends of the soft magnetic yoke, and together with the soft magnetic yoke form a closed magnetic circuit; a magnetizing coil is wound on the soft magnetic yoke, the magnetizing coil generates a magnetizing magnetic field in the soft magnetic yoke, and an upward and a downward magnetizing magnetic field are generated in the hard magnetic poles with upward magnetic moment and the hard magnetic poles with downward magnetic moment respectively through the upper soft magnetic flux guiding plate and the lower soft magnetic flux guiding plate; the magnetizing coil is connected to a magnetizing power supply.

14. A magnetization method, characterized in that, For magnetizing the hard magnetic pole array in the write head according to any one of claims 1 to 10, the method includes: The writing end and the supporting end of one or more adjacent hard magnetic poles having the same magnetic moment are respectively located in the middle of the magnetizing air gap with two planes of the soft magnetic yoke. A magnetizing coil is wound on the soft magnetic yoke, the magnetizing coil generates a magnetizing magnetic field in the soft magnetic yoke, the magnetizing coil is connected to a magnetizing power supply, and the magnetizing yoke moves on the surface of the second wafer to magnetize all the hard magnetic poles.

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