CN102841325A - Three-dimensional tunneling magnetic field sensor with bevel angle of 45 degrees and manufacturing method of sensor - Google Patents

Abstract

The invention belongs to the technical field of magnetic field detection, and in particular relates to a three-dimensional tunneling magnetic field sensor using a 45-degree oblique angle and a manufacturing method thereof. In the present invention, three tunnel giant magnetoresistance modules used for measuring different latitudes are placed on a groove or a boss structure with an inclination angle of 45 degrees to form a three-dimensional tunneling magnetic field sensor, so that the volume of the three-dimensional magnetic field sensor is reduced and the use The magnetoresistive sensing modules for measuring magnetic fields in different dimensions are more concentrated, so that the three-dimensional magnetic field sensors can be more flexibly used in navigation systems, magnetic field measurement systems, and devices for measuring various other physical quantities based on magnetic fields.

Description

A three-dimensional tunneling magnetic field sensor using a 45-degree oblique angle and its manufacturing method

technical field

The invention belongs to the technical field of magnetic field detection, and in particular relates to an oblique-angle three-dimensional tunneling magnetic field sensor and a manufacturing method thereof.

Background technique

In 1974, Slonczewski proposed that there is a tunnel giant magnetoresistance effect in the ferromagnetic layer/insulating layer/ferromagnetic layer structure. When the magnetization directions of the two ferromagnetic layers are parallel or antiparallel, the tunnel junction will have different resistance values. The principle of the spin tunneling effect produced by the ferromagnetic layer/insulating layer/ferromagnetic layer sandwich structure is that electrons tunnel through the potential barrier of the nonmagnetic layer to generate tunneling current. When the magnetization directions of the two ferromagnetic layers are parallel, the electrons of the majority spin subband in one ferromagnetic layer will enter the empty state of the majority subband of the other ferromagnetic layer, and the electrons of the minority spin subband will also go from one ferromagnetic layer to the empty state. The ferromagnetic layer enters the empty state of the minority subband of another ferromagnetic layer, and at this time, the probability of tunneling is high. When the magnetization directions of the two ferromagnetic layers are antiparallel, the spins of the electrons in the majority-spin subband in one ferromagnetic layer are parallel to the spins of the electrons in the minority-spin subband of the other ferromagnetic layer. , the electrons of the majority-spin subband in one ferromagnetic layer will enter the empty state of the minority sub-band of the other ferromagnetic layer, and the electrons of the minority-spin subband also enter the majority of the other ferromagnetic layer from one ferromagnetic layer In the empty state of the subband, the probability of tunneling is small. It can be seen that the tunnel conductance is related to the relative direction of the magnetization vectors of the two ferromagnetic layers.

At present, the main three-dimensional magnetic field sensor is usually spliced by a one-dimensional magnetic field sensing module and a two-dimensional magnetic field sensing module. Relatively large, the measured magnetic fields at different latitudes cannot be limited to a small range, which is not conducive to the development of measuring equipment in the direction of miniaturization and intensification.

Contents of the invention

The purpose of the present invention is to provide a three-dimensional magnetic field sensor structure based on the tunnel giant magnetoresistance effect and using a 45-degree oblique angle, which can reduce the volume of the three-dimensional magnetic field sensor, so as to facilitate the development of measuring equipment in the direction of miniaturization and intensification.

A three-dimensional tunneling magnetic field sensor using a 45-degree oblique angle provided by the present invention is mainly formed in a semiconductor substrate, and two opposite side walls are grooves with a 45-degree oblique angle to the surface of the semiconductor substrate. or boss structure;

A first tunnel giant magnetoresistive module is arranged on the first side wall of the groove or the boss;

Set the second tunnel giant magnetoresistive module on the first side wall of the groove or the boss, as shown in Figure 2 or Figure 4; or set the second tunnel at the bottom of the groove or the top of the boss Two tunnel giant magnetoresistance modules, as shown in Figure 1 or Figure 3;

A third tunnel giant magnetoresistive module is arranged on the second side wall of the groove or the boss;

The direction of the magnetic field measured by the second tunnel giant magnetoresistance module is perpendicular to the cross section of the groove or boss;

The directions of the magnetic field measured by the first tunnel giant magnetoresistance module and the third tunnel giant magnetoresistance module are parallel to the respective sidewall surfaces and are perpendicular to the magnetic field measured by the second tunnel giant magnetoresistance module direction.

The groove includes two sidewalls that are at an oblique angle of 45 degrees to the surface of the semiconductor substrate and a bottom wall that connects the two sidewalls and is parallel to the semiconductor substrate; A first tunnel giant magnetoresistance module is formed on the first side wall of the groove, a second tunnel giant magnetoresistance module is formed on the bottom wall of the groove, and a second tunnel giant magnetoresistance module is formed on the second sidewall of the groove A third tunnel giant magnetoresistance module is formed on it.

The groove is composed of two sidewalls that are at an oblique angle of 45 degrees to the surface of the semiconductor substrate; a first tunnel giant magnetoresistance module and a second tunnel giant magnetoresistance module are formed on the first sidewall of the groove. Two tunnel giant magnetoresistance modules, a third tunnel giant magnetoresistance module is formed on the second side wall of the groove.

The boss includes two sidewalls with an oblique angle of 45 degrees to the surface of the semiconductor substrate and a top wall connecting the two sidewalls; on the first sidewall of the boss A first tunnel giant magnetoresistance module is formed on the top wall of the boss, a second tunnel giant magnetoresistance module is formed on the top wall of the boss, and a third tunnel giant magnetoresistance module is formed on the second side wall of the boss. Magnetic resistance module.

The boss is composed of two sidewalls that are at an angle of 45 degrees to the surface of the semiconductor substrate; the first tunnel giant magnetoresistance module and the second tunnel giant magnetoresistance module are formed on the first sidewall of the boss. Two tunnel giant magnetoresistance modules, a third tunnel giant magnetoresistance module is formed on the second side wall of the boss.

The present invention also provides a method for manufacturing the above-mentioned three-dimensional tunneling magnetic field sensor using an oblique angle of 45 degrees. The specific steps are as follows:

Etching the semiconductor substrate by a wet etching method to form a groove or a boss structure with two opposite sidewalls at an oblique angle of 45 degrees to the surface of the semiconductor substrate;

Depositing a tunnel giant magnetoresistance material under the action of an external magnetic field and using a lift-off process to form a first tunnel giant magnetoresistance module on the first side wall of the formed groove or boss;

Deposit the tunnel giant magnetoresistance material under the action of an external magnetic field, and use the lift-off process to form the second sidewall on the first side wall of the formed groove or the boss, or on the bottom of the formed groove or the top of the boss. Tunnel giant magnetoresistance module;

The tunnel giant magnetoresistance material is deposited under the action of an external magnetic field, and a third tunnel giant magnetoresistance module is formed on the second side wall of the formed groove or boss by adopting a lift-off process.

in,

The two side walls formed by the groove structure are connected by a bottom wall parallel to the semiconductor substrate; under the action of an external magnetic field, a tunnel giant magnetoresistance material is deposited and a lift-off process is used on the first groove of the formed groove A first tunnel giant magnetoresistance module is formed on one side wall; a tunnel giant magnetoresistance material is deposited under the action of an external magnetic field, and a second tunnel giant magnetoresistance module is formed on the bottom wall of the formed groove by a lift-off process ; Deposit tunnel giant magnetoresistance material under the action of an external magnetic field and use a lift-off process to form a third tunnel giant magnetoresistance module on the second side wall of the formed groove.

The groove structure; depositing tunnel giant magnetoresistance material under the action of an external magnetic field and adopting a lift-off process to form a first tunnel giant magnetoresistance module on the first side wall of the formed groove; under the action of an external magnetic field Deposit the tunnel giant magnetoresistance material and use the lift-off process to form the second tunnel giant magnetoresistance module on the first side wall of the formed groove; deposit the tunnel giant magnetoresistance material under the action of an external magnetic field and use The lift-off process forms the third tunnel giant magnetoresistance module on the second sidewall of the formed groove.

The two side walls formed by the boss structure are connected by a top wall parallel to the semiconductor substrate; under the action of an external magnetic field, a tunnel giant magnetoresistive material is deposited, and a lift-off process is used on the first side of the formed boss. A first tunnel giant magnetoresistance module is formed on one side wall; a tunnel giant magnetoresistance material is deposited under the action of an external magnetic field, and a second tunnel giant magnetoresistance module is formed on the top wall of the formed boss by using a lift-off process ; Deposit tunnel giant magnetoresistance material under the action of an external magnetic field and use lift-off process to form a third tunnel giant magnetoresistance module on the second side wall of the formed boss.

The boss structure; depositing tunnel giant magnetoresistance material under the action of an external magnetic field and adopting a lift-off process to form a first tunnel giant magnetoresistance module on the first side wall of the formed boss; under the action of an applied magnetic field Next, deposit tunnel giant magnetoresistance material and use lift-off process to form a second tunnel giant magnetoresistance module on the first side wall of the formed boss; deposit tunnel giant magnetoresistance material under the action of an external magnetic field and adopt The lift-off process forms the third tunnel giant magnetoresistance module on the second side wall of the formed boss.

In the present invention, three tunnel giant magnetoresistance modules used for measuring different latitudes are placed on a groove or a boss structure with an inclination angle of 45 degrees to form a three-dimensional tunneling magnetic field sensor, so that the volume of the three-dimensional magnetic field sensor is reduced and the use The magnetoresistive sensing modules for measuring magnetic fields in different dimensions are more concentrated, so that the three-dimensional magnetic field sensors can be more flexibly used in navigation systems, magnetic field measurement systems, and devices for measuring various other physical quantities based on magnetic fields.

Description of drawings

Figures 1a, 2a, 3a and 4a are cross-sectional views of four embodiments of the three-dimensional tunneling magnetic field sensor provided by the present invention using a 45-degree oblique angle, and the x-y-z coordinate system in the figure is a standard coordinate system.

Figures 1b, 2b, 3b, and 4b are top views of the structures shown in Figures 1a, 2a, 3a, and 4a, respectively.

FIGS. 5 to 12 are process flow charts of embodiments of preparing the three-dimensional tunneling magnetic field sensors shown in FIGS. 1a, 2a, 3a, and 4a disclosed in the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. In the drawings, for the convenience of illustration, the thicknesses of layers and regions are enlarged or reduced, and the sizes shown do not represent actual sizes. Although these figures do not fully reflect the actual size of the device, they still completely reflect the mutual positions between the regions and the constituent structures, especially the upper-lower and adjacent relationships between the constituent structures.

Figures 1a, 2a, 3a, and 4a are cross-sectional views of four embodiments of the three-dimensional tunneling magnetic field sensor structure using a 45-degree oblique angle provided by the present invention, and Figures 1b, 2b, 3b, and 4b are Figures 1a, 2a, and 4b respectively. Top view of the 3D tunneling magnetic field sensor structure shown in 3a and 4a.

As shown in Fig. 1a, a groove is formed on the semiconductor substrate 12, and the groove includes two sidewalls forming an oblique angle of 45 degrees with the surface of the semiconductor substrate and a bottom wall connecting the two sidewalls. The first tunnel giant magnetoresistance module 1 and the third tunnel giant magnetoresistance module 3 are respectively located on the two side walls of the groove formed in the semiconductor substrate 12, and the second tunnel giant magnetoresistance module 2 is located on the bottom wall of the groove . The direction of the magnetic field measured by the second tunnel giant magnetoresistance module 2 is perpendicular to the cross section of the groove (the plane parallel to the paper surface in the figure is this cross section, the same below), the first tunnel giant magnetoresistance module 1 and the third The directions of the magnetic field measured by the tunnel giant magnetoresistance module 3 are parallel to the respective sidewall surfaces and are perpendicular to the direction of the magnetic field measured by the second tunnel giant magnetoresistance module 2 .

As shown in Fig. 2a, a groove is formed on the semiconductor substrate 12, and the groove is formed by two sidewalls which form an oblique angle of 45 degrees with the surface of the semiconductor substrate. The first tunnel giant magnetoresistance module 1 and the second tunnel giant magnetoresistance module 2 are located on the first side wall of the groove formed in the semiconductor substrate 12, and the third tunnel giant magnetoresistance module 3 is located on the second side wall of the groove. on a side wall. The direction of the magnetic field measured by the second tunnel giant magnetoresistance module 2 is perpendicular to the cross-section of the groove, and the directions of the magnetic fields measured by the first tunnel giant magnetoresistance module 1 and the third tunnel giant magnetoresistance module 3 are parallel to the respective grooves. The side wall surfaces are all perpendicular to the direction of the magnetic field measured by the second tunnel giant magnetoresistance module 2 .

As shown in FIG. 3 a , a boss is formed on the semiconductor substrate 12 , and the boss includes two sidewalls each forming an oblique angle of 45 degrees with the surface of the semiconductor substrate and a top wall connecting the two sidewalls. The first tunnel giant magnetoresistance module 1 and the third tunnel giant magnetoresistance module 3 are respectively located on the two side walls of the boss formed in the semiconductor substrate 12, and the second tunnel giant magnetoresistance module 2 is located on the top wall of the boss . The direction of the magnetic field measured by the second tunnel giant magnetoresistance module 2 is perpendicular to the cross-section of the boss, and the directions of the magnetic field measured by the first tunnel giant magnetoresistance module 1 and the third tunnel giant magnetoresistance module 3 are parallel to their respective The side wall surfaces are all perpendicular to the direction of the magnetic field measured by the second tunnel giant magnetoresistance module 2 .

As shown in Fig. 4a, a raised platform is formed on the semiconductor substrate 12, and the raised platform is composed of two sidewalls which form an oblique angle of 45 degrees with the surface of the semiconductor substrate. The first tunnel giant magnetoresistance module 1 and the second tunnel giant magnetoresistance module 2 are located on the first side wall of the boss formed in the semiconductor substrate 12, and the third tunnel giant magnetoresistance module 3 is located on the second side wall of the boss. on a side wall. The direction of the magnetic field measured by the second tunnel giant magnetoresistance module 2 is perpendicular to the cross-section of the boss, and the directions of the magnetic field measured by the first tunnel giant magnetoresistance module 1 and the third tunnel giant magnetoresistance module 3 are parallel to their respective The side wall surfaces are all perpendicular to the direction of the magnetic field measured by the second tunnel giant magnetoresistance module 2 .

In the four embodiments of the three-dimensional tunneling magnetic field sensor shown in Figures 1a, 2a, 3a, and 4a, the two sidewalls of the groove or the boss formed in the semiconductor substrate 12 are consistent with the original semiconductor substrate. The included angles formed by the surfaces are respectively α and β, and in the present invention α=β=45°.

Set the magnetic field values measured by the first tunnel giant magnetoresistance module 1 , the second tunnel giant magnetoresistance module 2 and the third tunnel giant magnetoresistance module 3 as X1 , X2 and X3 respectively. According to needs, set the x-axis, y-axis and z-axis of the standard coordinate system (identified in the upper right corner of Figure 1a, 2a, 3a, 4a respectively), where the x-axis and y-axis are parallel to the original semiconductor substrate surface, and the y-axis is perpendicular to the paper surface, and the z-axis is perpendicular to the surface of the original semiconductor substrate, then set the magnetic field values in the directions of the x-axis, y-axis and z-axis as x, y and z respectively, thus we can get The following formula:

y = X2;

X3*cos β –X1*cosα = x;

X3*sin β + X1*sin α = z.

Since α = β = 45°, we have:

y = x2;

cos(45)*(X3 –X1) = x;

sin(45)*(X3 + X1) = z.

The three-dimensional tunneling magnetic field sensor proposed by the present invention can limit the measured magnetic fields at different latitudes to a smaller range.

The three-dimensional tunneling magnetic field sensor proposed by the present invention can be manufactured by many methods, and what is described below is an embodiment of the manufacturing method of the three-dimensional tunneling magnetic field sensor structure as shown in Figures 1a, 2a, 3a, and 4a disclosed by the present invention , FIGS. 5-12 describe the process of a part of the integrated circuit composed of the structures shown in FIGS. 1a, 2a, 3a, and 4a disclosed by the present invention. Take silicon substrates as an example.

As shown in FIG. 5 , a silicon oxide film 201 is oxidized and grown on the surface of the provided silicon substrate 200 , and then a layer of photoresist 301 is deposited on the silicon oxide film 201 .

Next, mask, expose, and develop to form patterns, and etch away the silicon oxide film 201 that is not protected by photoresist to expose the surface of the silicon substrate 200, and then use wet etching to etch the exposed silicon. The required groove or boss structure is formed on the substrate 201 , and then the photoresist 301 is stripped off and the remaining silicon oxide film 201 is etched away.

Different structures can be obtained through the selection of photoresist patterns and the control of silicon etching conditions:

Fig. 6a is a groove structure formed in a silicon substrate for forming the three-dimensional tunneling magnetic field sensor shown in Fig. 1a.

Fig. 6b is a groove structure formed in a silicon substrate for forming the three-dimensional tunneling magnetic field sensor shown in Fig. 2a.

Fig. 6c is a boss structure formed in a silicon substrate for forming the three-dimensional tunneling magnetic field sensor shown in Fig. 3a.

Fig. 6d shows the boss structure required for forming the three-dimensional tunneling magnetic field sensor shown in Fig. 4a formed in the silicon substrate.

The sidewalls of the grooves or bosses shown in FIGS. 6a, 6b, 6c, and 6d are all beveled at 45 degrees.

Next, deposit a layer of photoresist 302 on the structures shown in Figures 6a, 6b, 6c, and 6d, and mask, expose, and develop to define the position of the first tunnel giant magnetoresistive module, as shown in Figures 7a, 7b, 7c, 7d.

Next, deposit the tunnel giant magnetoresistance material under the action of an external magnetic field, and use the lift-off process (the Lift-off process is to first apply glue and photolithography on the substrate, and then prepare a dielectric film. Where there is a place, the dielectric film is formed on the photoresist, and where there is no photoresist, the dielectric film is directly formed on the substrate. When using a solvent to remove the photoresist on the substrate, the unnecessary dielectric film will be With the dissolution of the photoresist, it falls off in the solvent, and the part of the dielectric film directly formed on the substrate remains to form a pattern.) Form the first tunnel giant magnetoresistive module (shown by the symbol 203), as shown in Figure 8a, 8b, 8c, 8d. The direction of the magnetic field measured by the first tunnel giant magnetoresistance module 203 is controlled by controlling the direction of the external magnetic field when depositing the tunnel giant magnetoresistance material.

Next, deposit a layer of photoresist 303 on the structures shown in Figures 8a, 8b, 8c, and 8d, and mask, expose, and develop to define the position of the second tunnel giant magnetoresistive module, as shown in Figures 9a, 9b, 9c, 9d.

Next, the tunnel giant magnetoresistance material is deposited under the action of an external magnetic field, and a second tunnel giant magnetoresistance module (shown by reference numeral 204 ) is formed by using a lift-off process, as shown in FIGS. 10 a , 10 b , 10 c , and 10 d. The direction of the magnetic field measured by the second tunnel giant magnetoresistance module 204 is controlled by controlling the direction of the external magnetic field when depositing the tunnel giant magnetoresistance material.

Next, deposit a layer of photoresist 304 on the structures shown in Figures 10a, 10b, 10c, and 10d, and mask, expose, and develop to define the position of the third tunnel giant magnetoresistive module, as shown in Figures 11a, 11b, 11c, 11d shown.

Next, the tunnel giant magnetoresistance material is deposited under the action of an external magnetic field, and a third tunnel giant magnetoresistance module (shown by reference numeral 205 ) is formed by using a lift-off process, as shown in FIGS. 12a , 12b , 12c , and 12d . The direction of the magnetic field measured by the tunnel giant magnetoresistance module 205 is controlled by controlling the direction of the external magnetic field when depositing the tunnel giant magnetoresistance material.

As mentioned above, many widely different embodiments can be constructed without departing from the spirit and scope of the present invention. It should be understood that the invention is not limited to the specific examples described in the specification, except as defined in the appended claims.

Claims (10)

1. A three-dimensional tunneling magnetic field sensor using a 45-degree oblique angle is characterized in that a groove or a boss structure is mainly formed in a semiconductor substrate, and two opposite side walls of the groove or the boss structure and the semiconductor substrate form a 45-degree oblique angle;

arranging a first tunnel giant magnetoresistance module on a first side wall of the groove or the boss;

arranging a second tunnel giant magnetoresistance module on the first side wall of the groove or the boss; or a second tunnel giant magnetoresistance module is arranged at the bottom of the groove or the top of the boss;

a third tunnel giant magnetoresistance module is arranged on the second side wall of the groove or the boss;

the direction of the magnetic field measured by the second tunnel giant magnetoresistance module is vertical to the cross section of the groove or the lug boss;

the directions of the magnetic fields measured by the first tunnel giant magnetoresistance module and the third tunnel giant magnetoresistance module are parallel to the side wall surfaces where the first tunnel giant magnetoresistance module and the third tunnel giant magnetoresistance module are respectively located and are perpendicular to the direction of the magnetic field measured by the second tunnel giant magnetoresistance module.

2. The three-dimensional tunneling magnetic field sensor according to claim 1, wherein the recess comprises two sidewalls each having an oblique angle of 45 degrees with respect to the surface of the semiconductor substrate and a bottom wall parallel to the semiconductor substrate connecting the two sidewalls;

a first tunnel giant magnetoresistance module is formed on a first sidewall of the recess,

a second tunnel giant magnetoresistance module is formed on the bottom wall of the groove,

and a third tunnel giant magnetoresistance module is formed on the second side wall of the groove.

3. The three-dimensional tunneling magnetic field sensor according to claim 1, wherein the trench is formed by two sidewalls each having an oblique angle of 45 degrees with respect to the surface of the semiconductor substrate;

a first tunnel giant magneto-resistance module and a second tunnel giant magneto-resistance module are formed on the first side wall of the groove,

and a third tunnel giant magnetoresistance module is formed on the second side wall of the groove.

4. The three-dimensional tunneling magnetic field sensor according to claim 1, wherein said mesa comprises two sidewalls each angled at 45 degrees from the surface of said semiconductor substrate and a top wall connecting said two sidewalls;

a first tunnel giant magnetoresistance module is formed on a first sidewall of the boss,

a second tunnel giant magnetoresistance module is formed on the top wall of the boss,

and a third tunnel giant magnetoresistance module is formed on the second side wall of the boss.

5. The three-dimensional tunneling magnetic field sensor according to claim 1, wherein the mesa is formed by two sidewalls each having an oblique angle of 45 degrees with respect to the surface of the semiconductor substrate;

a first tunnel giant magneto-resistance module and a second tunnel giant magneto-resistance module are formed on the first side wall of the boss,

and a third tunnel giant magnetoresistance module is formed on the second side wall of the boss.

6. A method for fabricating a three-dimensional tunneling magnetic field sensor using a 45 ° bevel according to claim 1, characterized by the following steps:

etching the semiconductor substrate by adopting a wet etching method to form a groove or boss structure with two opposite side walls which form an oblique angle of 45 degrees with the surface of the semiconductor substrate;

depositing a tunnel giant magnetoresistance material under the action of an external magnetic field and forming a first tunnel giant magnetoresistance module on the first side wall of the formed groove or boss by adopting a lift-off process;

depositing a tunnel giant magnetoresistance material under the action of an external magnetic field, and forming a second tunnel giant magnetoresistance module on the first side wall of the formed groove or boss, or on the bottom of the formed groove or the top of the boss by adopting a lift-off process;

and depositing tunnel giant magneto-resistance materials under the action of an external magnetic field, and forming a third tunnel giant magneto-resistance module on the second side wall of the formed groove or boss by using a lift-off process.

7. The method of claim 6, wherein in the groove structure,

the two side walls formed are connected by a bottom wall parallel to the semiconductor substrate;

depositing a tunnel giant magneto-resistance material under the action of an external magnetic field and forming a first tunnel giant magneto-resistance module on the first side wall of the formed groove by adopting a lift-off process;

depositing a tunnel giant magnetoresistance material under the action of an external magnetic field and forming a second tunnel giant magnetoresistance module on the bottom wall of the formed groove by adopting a lift-off process;

and depositing tunnel giant magneto-resistance materials under the action of an external magnetic field and forming a third tunnel giant magneto-resistance module on the second side wall of the formed groove by adopting a lift-off process.

8. The method of claim 6, wherein in the groove structure,

depositing a tunnel giant magneto-resistance material under the action of an external magnetic field and forming a first tunnel giant magneto-resistance module on the first side wall of the formed groove by adopting a lift-off process;

depositing a tunnel giant magneto-resistance material under the action of an external magnetic field and forming a second tunnel giant magneto-resistance module on the first side wall of the formed groove by adopting a lift-off process;

and depositing tunnel giant magneto-resistance materials under the action of an external magnetic field and forming a third tunnel giant magneto-resistance module on the second side wall of the formed groove by adopting a lift-off process.

9. The method of claim 6, wherein in the mesa structure,

the two side walls formed are connected by a top wall parallel to the semiconductor substrate;

depositing a tunnel giant magnetoresistance material under the action of an external magnetic field and forming a first tunnel giant magnetoresistance module on the first side wall of the formed boss by adopting a lift-off process;

depositing a tunnel giant magnetoresistance material under the action of an external magnetic field and forming a second tunnel giant magnetoresistance module on the top wall of the formed boss by adopting a lift-off process;

and depositing a tunnel giant magneto-resistance material under the action of an external magnetic field, and forming a third tunnel giant magneto-resistance module on the second side wall of the formed boss by adopting a lift-off process.

10. The method of claim 6, wherein in the mesa structure,

depositing a tunnel giant magnetoresistance material under the action of an external magnetic field and forming a first tunnel giant magnetoresistance module on the first side wall of the formed boss by adopting a lift-off process;

depositing a tunnel giant magnetoresistance material under the action of an external magnetic field and forming a second tunnel giant magnetoresistance module on the first side wall of the formed boss by adopting a lift-off process;

and depositing a tunnel giant magneto-resistance material under the action of an external magnetic field, and forming a third tunnel giant magneto-resistance module on the second side wall of the formed boss by adopting a lift-off process.

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