A magnetic sensor, its fabrication method, and an electronic device.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-03-22
- Publication Date
- 2026-08-14
AI Technical Summary
[0006]本发明提供一种磁性传感器、制备方法以及电子设备，以解决基于SOT效应的铁磁层偏置的功耗高的问题
[0047]本发明提供的磁性传感器，采用反铁磁层对所述铁磁层的磁化方向进行一次偏置，利用SOT效应层在所述第一电极与所述第二电极之间引入电流的情况下对所述铁磁层的磁化方向进行的二次偏置；一次偏置和二次偏置使得所述铁磁层的磁化方向与电流方向之间初始夹角的值达到一预设夹角值；在所述一次偏置的辅助下，利用SOT效应来实现二次偏置以达到预设夹角值的电流可以大大降低，从而所需消耗的功率降低，因而解决了单一的使用所述二次偏置达到所述预设夹角值时存在的高功耗问题。
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Figure CN114883481B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of sensors, and more particularly to a magnetic sensor, its fabrication method, and an electronic device. Background Technology
[0002] Magnetic sensors have wide applications in magnetic field detection, navigation, current detection, and non-destructive testing. Currently, based on different physical principles, magnetic sensors mainly include Hall magnetic sensors, anisotropic magnetoresistive sensors (AMR), giant magnetoresistive sensors (GMR), tunnel magnetoresistive sensors (TMR), and giant magneto-impedance sensors (GMI).
[0003] The aforementioned existing magnetic sensors cannot achieve a balance between the following three aspects: high sensing accuracy, simple manufacturing process, and simple operation. Hall sensors suffer from low accuracy, magnetoresistive sensors, such as anisotropic magnetoresistive sensors, giant magnetoresistive sensors, and tunneling joint magnetoresistive sensors, suffer from complex manufacturing processes and complex operation methods, and giant magneto-impedance sensors (GMI) suffer from complex operation.
[0004] For anisotropic magnetoresistive sensors, to achieve good sensitivity, the magnetization direction of the magnetic material in the sensing element should be biased at 45° to the current direction. Common biasing methods include soft adjacent layer (SAL), Barber electrodes, and current biasing based on the SOT (spin-orbit torque) effect. However, SOT-based biasing can lead to high power consumption due to current shunting, posing challenges to device development, manufacturing processes, and cost.
[0005] Therefore, developing a sensor that can both utilize the advantages of SOT effect bias and reduce SOT effect power consumption has become a key technical issue that needs to be addressed by those skilled in the art. Summary of the Invention
[0006] This invention provides a magnetic sensor, a fabrication method, and an electronic device to solve the problem of high power consumption in ferromagnetic layer biasing based on the SOT effect.
[0007] According to a first aspect of the present invention, a magnetic sensor is provided, comprising:
[0008] Substrate;
[0009] A functional thin film layer is formed on the substrate; and
[0010] The metal electrode includes a first electrode and a second electrode, wherein the first electrode covers a first end of the functional thin film layer and the second electrode covers a second end of the functional thin film layer; the first end and the second end are opposite ends along the horizontal direction of the functional thin film layer.
[0011] The functional thin film layer comprises: an antiferromagnetic layer, a ferromagnetic layer, and an SOT effect layer sequentially formed on the substrate in a direction away from the substrate; wherein:
[0012] The antiferromagnetic layer is used to bias the magnetization direction of the ferromagnetic layer once.
[0013] The SOT effect layer is used to perform a secondary bias on the magnetization direction of the ferromagnetic layer when a current is introduced between the first electrode and the second electrode.
[0014] The primary bias and the secondary bias are used to make the initial angle between the magnetization direction and the current direction of the ferromagnetic layer reach a preset angle value.
[0015] Optionally, the preset included angle value is 45°.
[0016] Optionally, the functional thin film layer further includes a transition layer formed between the substrate and the antiferromagnetic layer.
[0017] Optionally, the thickness of the antiferromagnetic layer is 1-40 nm.
[0018] Optionally, the material constituting the antiferromagnetic layer is FeMn or IrMn.
[0019] Optionally, the thickness of the ferromagnetic layer is 1-10 nm.
[0020] Optionally, the material constituting the ferromagnetic layer is NiFe.
[0021] Optionally, the thickness of the SOT effect layer is 1-10 nm.
[0022] Optionally, the material constituting the SOT effect layer is a heavy metal material or a topological insulating material that can generate a spin-orbit effect.
[0023] Optionally, the thickness of the metal electrode is 10-200 nm.
[0024] Optionally, the material constituting the metal electrode is copper or gold.
[0025] Optionally, the material of the transition layer is Ta.
[0026] According to a second aspect of the present invention, a method for fabricating a magnetic sensor is provided, for fabricating a magnetic sensor as described in any one of the first aspects of the present invention, the method comprising:
[0027] Provide one of the aforementioned substrates;
[0028] A patterned functional thin film layer is formed on the substrate; the functional thin film layer includes: an antiferromagnetic layer, a ferromagnetic layer, and a SOT effect layer sequentially formed on the substrate in a direction away from the substrate; and
[0029] The metal electrode is formed, the metal electrode including a first electrode and a second electrode, the first electrode covering a first end of the functional thin film layer, and the second electrode covering a second end of the functional thin film layer.
[0030] Optionally, a patterned functional thin film layer is formed on the substrate, specifically including:
[0031] A first photoresist coating is applied to the substrate surface, and the coated photoresist is patterned and developed for the first time to form a functional thin film layer cavity.
[0032] The functional thin film layer is deposited in the cavity of the functional thin film layer and on the surface of the photoresist after the first development.
[0033] The photoresist and the functional thin film layer deposited on the photoresist surface are stripped to form a patterned functional thin film layer.
[0034] Optionally, forming the metal electrode specifically includes:
[0035] A second photoresist coating is performed on the substrate and the patterned functional thin film layer, and the coated photoresist is patterned a second time and developed a second time. After the second development, a first electrode cavity and a second electrode cavity are formed.
[0036] Metal electrode material is deposited on the remaining photoresist surface after the second development and in the first electrode cavity and the second electrode cavity;
[0037] The photoresist and the metal electrode material on the surface of the photoresist are stripped off to form the first electrode and the second electrode.
[0038] Optionally, a patterned functional thin film layer is formed on the substrate, specifically including:
[0039] The functional thin film layer is deposited on the surface of the substrate;
[0040] A third photoresist coating is performed on the surface of the deposited functional thin film layer, and the coated photoresist is then patterned and developed a third time.
[0041] The photoresist retained after the third development is used as a mask to etch the deposited functional thin film layer, and the photoresist is removed to form the patterned functional thin film layer; the shape of the photoresist retained after the third development is adapted to the shape of the functional thin film layer.
[0042] Optionally, forming the metal electrode specifically includes:
[0043] Metal electrode material is deposited on the substrate and the patterned functional thin film layer;
[0044] A fourth photoresist coating is performed on the surface of the metal electrode material, and the coated photoresist is then patterned and developed a fourth time.
[0045] Using the photoresist remaining after the fourth development as a mask, the metal electrode material is etched to remove the photoresist and form the first electrode and the second electrode; the shape of the photoresist remaining after the fourth development is adapted to the shape of the first electrode and the second electrode.
[0046] According to a third aspect of the present invention, an electronic device is provided, comprising the magnetic sensor described in any of the first aspects of the present invention.
[0047] The magnetic sensor provided by this invention employs an antiferromagnetic layer to perform a primary bias on the magnetization direction of the ferromagnetic layer, and utilizes a SOT effect layer to perform a secondary bias on the magnetization direction of the ferromagnetic layer when a current is introduced between the first and second electrodes. The primary and secondary biases cause the initial angle between the magnetization direction of the ferromagnetic layer and the current direction to reach a preset angle value. With the assistance of the primary bias, the current required to achieve the preset angle value through the secondary bias using the SOT effect can be greatly reduced, thereby reducing the power consumption required. This solves the high power consumption problem that exists when using the secondary bias alone to achieve the preset angle value. Attached Figure Description
[0048] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0049] Figure 1 This is a schematic diagram of a magnetic sensor structure etched at different stages in one embodiment of the present invention. Figure 1 ;
[0050] Figure 2 This is a schematic flowchart of a method for preparing a magnetic sensor according to an embodiment of the present invention;
[0051] Figure 3 This is a schematic diagram of a magnetic sensor structure etched at different stages in one embodiment of the present invention. Figure 2 ;
[0052] Figure 4 This is a schematic diagram of a magnetic sensor structure etched at different stages in one embodiment of the present invention. Figure 3 ;
[0053] Figure 5 This is a schematic diagram of a magnetic sensor structure etched at different stages in one embodiment of the present invention. Figure 4 ;
[0054] Figure 6 This is a schematic diagram of a magnetic sensor structure etched at different stages in one embodiment of the present invention. Figure 5 ;
[0055] Figure 7 This is a schematic diagram of a magnetic sensor structure etched at different stages in one embodiment of the present invention. Figure 6 ;
[0056] Figure 8 This is a schematic diagram of a magnetic sensor structure etched at different stages in one embodiment of the present invention. Figure 7 ;
[0057] Figure 9 This is a schematic diagram of a magnetic sensor structure etched at different stages in one embodiment of the present invention. Figure 8 ;
[0058] Figure 10 This is a schematic diagram of a magnetic sensor structure etched at different stages in one embodiment of the present invention. Figure 9 ;
[0059] Figure 11 This is a schematic diagram of a magnetic sensor structure etched at different stages in one embodiment of the present invention. Figure 10 ;
[0060] Figure 12 This is a schematic diagram of a magnetic sensor structure etched at different stages in another embodiment of the present invention. Figure 1 ;
[0061] Figure 13 This is a schematic diagram of a magnetic sensor structure etched at different stages in another embodiment of the present invention. Figure 2 ;
[0062] Figure 14This is a schematic diagram of a magnetic sensor structure etched at different stages in another embodiment of the present invention. Figure 3 ;
[0063] Figure 15 This is a schematic diagram of a magnetic sensor structure etched at different stages in another embodiment of the present invention. Figure 4 ;
[0064] Figure 16 This is a schematic diagram of a magnetic sensor structure etched at different stages in another embodiment of the present invention. Figure 5 ;
[0065] Figure 17 This is a schematic diagram of a magnetic sensor structure etched at different stages in another embodiment of the present invention. Figure 6 ;
[0066] Figure 18 This is a schematic diagram of a magnetic sensor structure etched at different stages in another embodiment of the present invention. Figure 7 ;
[0067] Figure 19 This is a schematic diagram of a magnetic sensor structure etched at different stages in another embodiment of the present invention. Figure 8 ;
[0068] Figure 20 This is a schematic diagram of a magnetic sensor structure etched at different stages in another embodiment of the present invention. Figure 9 ;
[0069] Explanation of reference numerals in the attached figures:
[0070] 101-Substrate;
[0071] 102 - Functional thin film layer;
[0072] 1021-SOT effect layer;
[0073] 1022-Ferromagnetic layer;
[0074] 1023-Antiferromagnetic layer;
[0075] 103 - First electrode;
[0076] 104 - Second electrode;
[0077] 105 - Photoresist;
[0078] 106-Metallic electrode material. Detailed Implementation
[0079] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0080] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0081] Magnetic sensors have a wide range of applications in magnetic field detection, navigation, current detection, and non-destructive testing.
[0082] For anisotropic magnetoresistive sensors, to achieve good sensitivity, the magnetization direction of the magnetic material in the sensing element should be biased at 45° to the current direction. Common biasing methods include soft magnetic proximity layers, Barber electrodes, and current biasing based on the SOT effect. However, soft magnetic proximity layer biasing leads to high power consumption, while Barber electrodes pose challenges in device development, fabrication processes, and cost.
[0083] Therefore, the applicant found that the technical problem that magnetic sensors need to solve is how to both utilize the SOT effect for biasing and reduce the SOT effect power consumption.
[0084] In view of this, the present invention creatively proposes a method for biasing using an antiferromagnetic layer to assist the SOT effect; the magnetic sensor manufactured using the method proposed in this invention not only utilizes the SOT effect to achieve biasing, but also reduces power consumption; thus solving the problem of high power consumption in magnetization direction biasing.
[0085] The technical solution of the present invention will be described in detail below with reference to specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.
[0086] Please refer to Figure 1According to an embodiment of the present invention, a magnetic sensor is provided, comprising:
[0087] Substrate 101;
[0088] A functional thin film layer 102 is formed on the substrate 101; and
[0089] The metal electrode includes a first electrode 103 and a second electrode 104. The first electrode 103 covers a first end of the functional thin film layer 102, and the second electrode 104 covers a second end of the functional thin film layer 102. The first end and the second end are opposite ends along the horizontal direction of the functional thin film layer 102.
[0090] The functional thin film layer 102 includes an antiferromagnetic layer 1023, a ferromagnetic layer 1022, and an SOT effect layer 1021 sequentially formed on the substrate 101 in a direction away from the substrate 101.
[0091] Among them, non-conductive substrates can all be used as substrates 101, such as silicon oxide and other flexible substrates or thin films;
[0092] In one embodiment, the first electrode 103 is a positive electrode and the second electrode 104 is a negative electrode; in another embodiment, the first electrode 103 is a negative electrode and the second electrode 104 is a positive electrode; the first electrode 103 and the second electrode 104 are used to: after introducing current between the first electrode 103 and the second electrode 104, the magnetization direction of the ferromagnetic layer 1022 is biased.
[0093] Wherein: the antiferromagnetic layer 1023 is used to bias the magnetization direction of the ferromagnetic layer 1022. Specifically, based on the inherent characteristics of the antiferromagnetic layer 1023, the antiferromagnetic layer 1023 will "pin" the magnetic moment direction of its adjacent ferromagnetic layer 1022 through the magnetic exchange force, thereby causing the magnetization direction of the adjacent ferromagnetic layer 1022 to shift, forming a bias.
[0094] The SOT effect layer 1021 is used to perform a secondary bias on the magnetization direction of the ferromagnetic layer 1022 when a current is introduced between the first electrode 103 and the second electrode 104.
[0095] The antiferromagnetic layer 1023 is disposed between the substrate 101 and the ferromagnetic layer 1022, and contacts the ferromagnetic layer 1022. The SOT effect layer 1021 contacts the ferromagnetic layer 1022. First, the antiferromagnetic layer 1023 biases the magnetization direction of the ferromagnetic layer 1022. Second, when current is introduced between the first electrode 103 and the second electrode 104, the current passes through the SOT effect layer 1021 and generates the SOT effect, thus the SOT effect layer 1021 biases the ferromagnetic layer 1022 a second time. The SOT effect refers to the fact that when current is introduced between the first electrode 103 and the second electrode 104, the current passes through the SOT effect layer 1021, and under the action of the introduced current, the magnetization direction of the ferromagnetic layer 1022 in contact with the SOT effect layer 1021 will be biased, i.e., the aforementioned secondary bias.
[0096] The primary bias and the secondary bias are used to make the initial angle between the magnetization direction and the current direction of the ferromagnetic layer 1022 reach a preset angle value. The current direction refers to the direction of the current introduced between the first electrode 103 and the second electrode 104.
[0097] The preset included angle value is the bias angle formed by the combined effect of the secondary bias and the primary bias of the ferromagnetic layer 1022.
[0098] With the assistance of the primary bias, the current required to achieve the preset angle value by utilizing the SOT effect for secondary bias can be greatly reduced, thereby solving the high power consumption problem that exists when using the secondary bias alone to achieve the preset angle value.
[0099] In one embodiment, preferably, the preset included angle value is 45°.
[0100] Since the resistance of the magnetic sensor changes with the angle between the magnetization direction of the ferromagnetic layer 1022 and the current direction, when the preset angle value is 45° in the initial state, the resistance of the magnetic sensor reaches an ideal value, so that the magnetic sensor works in a good linear region, making the measurement more accurate.
[0101] The initial angle is the value of the angle between the magnetization direction of the ferromagnetic layer 1022 and the current direction when the magnetic sensor is in its initial state.
[0102] In one embodiment, the functional thin film layer 102 further includes a transition layer (not shown) formed between the substrate 101 and the antiferromagnetic layer 1023. In a specific embodiment, the material of the transition layer is Ta.
[0103] To ensure that the ferromagnetic layer 1022 reaches the preset included angle value due to the secondary bias and the primary bias, both the secondary bias and the primary bias need to achieve predetermined effects. Therefore, corresponding restrictions are placed on the parameters of the material of the antiferromagnetic layer 1023 that generates the primary bias. At the same time, corresponding restrictions are also placed on the parameters of the material of the SOT effect layer 1021 that generates the secondary bias and the material of the metal electrode, as detailed below:
[0104] The thicknesses are all thicknesses along the direction away from the substrate 101;
[0105] In one embodiment, the thickness of the antiferromagnetic layer 1023 is 1-40 nm.
[0106] In one embodiment, the material constituting the antiferromagnetic layer 1023 is FeMn or IrMn; of course, other types of materials can be used, and the present invention is not limited thereto.
[0107] In one embodiment, the thickness of the ferromagnetic layer 1022 is 1-10 nm.
[0108] In one embodiment, the material constituting the ferromagnetic layer 1022 is NiFe; of course, other types of materials can be used, and the present invention is not limited thereto.
[0109] In one embodiment, the thickness of the SOT effect layer 1021 is 1-10 nm.
[0110] In one embodiment, the material constituting the SOT effect layer 1021 is a heavy metal material or a topological insulating material that can generate a spin-orbit effect; of course, other types of materials can be used, and the present invention is not limited thereto.
[0111] In one embodiment, the thickness of the metal electrode is 10-200 nm.
[0112] In one embodiment, the material constituting the metal electrode is copper or gold; of course, other types of materials can be used, and the present invention is not limited thereto.
[0113] By selecting the parameters of each structural layer material mentioned above, a magnetic sensor product with precise measurement can be manufactured.
[0114] Furthermore, in other embodiments of the present invention, a method for fabricating a magnetic sensor is also provided, for fabricating the magnetic sensor described in any of the foregoing embodiments. Please refer to [reference needed]. Figure 2 ,like Figure 2 and combined Figure 1 As shown, the method includes:
[0115] S11: Provide a substrate 101;
[0116] In one specific embodiment, after providing the substrate 101, the method further includes cleaning the substrate to remove metal impurity particles and organic impurity particles on the substrate 101.
[0117] S12: A patterned functional thin film layer 102 is formed on the substrate 101; the functional thin film layer 102 includes: an antiferromagnetic layer 1023, a ferromagnetic layer 1022, and an SOT effect layer 1021 sequentially formed on the substrate 101 in a direction away from the substrate 101; and
[0118] S13: Form the metal electrode, which includes a first electrode 103 and a second electrode 104. The first electrode 103 covers a first end of the functional thin film layer 102, and the second electrode 104 covers a second end of the functional thin film layer 102.
[0119] The following specific embodiments will be used to illustrate the preparation method of the above-mentioned magnetic sensor.
[0120] In one embodiment, please refer to Figure 1-11 The method includes:
[0121] S11: Provide a substrate 101; clean the substrate to remove metal impurity particles and organic impurity particles on the substrate 101.
[0122] S12: Forming the patterned functional thin film layer 102 on the substrate 101; specifically, in this embodiment, S12 may specifically include:
[0123] S121: A first photoresist 105 is coated on the surface of the substrate 101. The device structure after photoresist coating is as follows: Figure 3 As shown; then the coated photoresist 105 is first developed, and the device structure after development is as follows. Figure 4 As shown; next, the developed photoresist is etched to form functional thin film layer cavities, and the etched device structure is as follows. Figure 5 As shown;
[0124] The process of first coating the substrate 101 with photoresist, and first patterning and first developing the coated photoresist 105 to form a functional thin film cavity can be carried out using the following photolithography techniques: such as step-by-step lithography, laser direct-write lithography, and electron beam lithography; of course, it should be understood that other types of photolithography techniques can also be used, and the present invention is not limited thereto.
[0125] The pattern of the photoresist 105 after the first patterning is adapted to the shape of the functional thin film cavity; the thin film cavity is formed after the first development removes part of the photoresist 105.
[0126] S122: The functional thin film layer 102 is deposited in the cavity of the functional thin film layer and on the surface of the photoresist 105 after the first development; the device structure after this step is as follows. Figure 6 As shown.
[0127] The functional thin film layer 102 includes an antiferromagnetic layer 1023, a ferromagnetic layer 1022, and an SOT effect layer 1021 formed sequentially along a direction away from the substrate 101.
[0128] S123: Strip the photoresist 105 and the functional thin film layer 102 deposited on the surface of the photoresist 105 to form a patterned functional thin film layer 102; the device structure after this step is as follows. Figure 7 As shown.
[0129] The patterned functional thin film layer 102 is formed in the cavity of the functional thin film layer, and the shape of the patterned functional thin film layer 102 is determined by the shape of the cavity of the functional thin film layer; the patterned functional thin film layer 102 is the final functional thin film layer 102 formed in the magnetic sensor.
[0130] S13: Forming the metal electrode, the metal electrode including a first electrode 103 and a second electrode 104, the first electrode 103 covering a first end of the functional thin film layer 102, and the second electrode 104 covering a second end of the functional thin film layer 102. In one embodiment, step 13 specifically includes:
[0131] S131: A second photoresist 105 is applied to the substrate 101 and the patterned functional thin film layer 102. The photoresist 105 covers the substrate 101 and surrounds the functional thin film layer 102. The device structure after photoresist application is shown in the figure. Figure 8 As shown; next, the coated photoresist 105 is patterned a second time and developed a second time. The device structure diagram after development is shown below. Figure 9 As shown; then the developed photoresist is etched to form the first electrode cavity and the second electrode cavity, and the device structure after etching is as follows. Figure 10 As shown.
[0132] The first electrode cavity and the second electrode cavity are surrounded by the remaining photoresist 105 after the second development and the patterned functional thin film layer 102 in step 12, respectively formed on the first side and the second side of the functional thin film layer, the first side and the second side corresponding to the first end and the second end of the aforementioned functional thin film layer.
[0133] S132: Deposit metal electrode material 106 on the surface of the remaining photoresist 105 after the second development, and in the first electrode cavity and the second electrode cavity; the device structure diagram after this step is as follows. Figure 11 As shown.
[0134] The metal electrode material 106 in the first electrode cavity and the second electrode cavity covers the first end and the second end of the functional thin film layer 102, and is spread all over the surface of the substrate 101 in the first electrode cavity and the second electrode cavity.
[0135] S133: Strip the photoresist 105 and the metal electrode material 106 on the surface of the photoresist 105 to form the first electrode 103 and the second electrode 104; the device structure diagram after this step is as follows. Figure 1 As shown.
[0136] The metal electrode material in the first electrode cavity constitutes the first electrode; the metal electrode material in the second electrode cavity constitutes the second electrode.
[0137] Please continue to refer to this. Figures 12-20 and combined Figure 1 and Figure 2 This invention provides a method for fabricating a magnetic sensor according to another specific embodiment. The method in this embodiment differs from the method in the foregoing embodiments in the formation of the patterned functional thin film layer and the metal electrode; other aspects are the same as in the foregoing embodiments and will not be repeated here. Specifically, forming the patterned functional thin film layer 102 on the substrate 101 includes:
[0138] The functional thin film layer 102 is deposited on the surface of the substrate 101;
[0139] A third photoresist 105 is first coated on the surface of the deposited functional thin film layer 102. The device structure after the third photoresist coating is as follows. Figure 12 As shown; next, the coated photoresist 105 undergoes a third patterning and a third development, and the device structure diagram after development is shown. Figure 13 As shown; then the developed photoresist is etched to form a patterned photoresist, and the etched device structure diagram is shown. Figure 14 As shown;
[0140] The functional thin film layer 102 is etched and deposited using patterned photoresist 105 as a mask. The device structure after etching is shown in the figure below. Figure 15 As shown; then the patterned photoresist 105 is removed to form the patterned functional thin film layer 102. The device structure diagram after this step is shown. Figure 16As shown. The shape of the patterned photoresist 105 is adapted to the shape of the functional thin film layer 102.
[0141] The formation of the metal electrode specifically includes:
[0142] Metal electrode material 106 is deposited on the substrate 101 and the patterned functional thin film layer 102. The device structure diagram after this step is shown below. Figure 17 As shown;
[0143] A fourth layer of photoresist 105 is applied to the surface of the metal electrode material 106, resulting in a device structure as shown below. Figure 18 As shown; next, the coated photoresist 105 undergoes a fourth patterning and fourth development, and the developed device is shown... Figure 19 As shown; then the developed photoresist is etched to form a patterned photoresist 105, as shown. Figure 20 As shown;
[0144] Using the patterned photoresist 105 as a mask, the metal electrode material 106 is etched to remove the photoresist 105, forming the first electrode 103 and the second electrode 104, as follows. Figure 1 As shown; the shape of the remaining photoresist 105 after the fourth development is adapted to the shape of the first electrode 103 and the second electrode 104.
[0145] Furthermore, in other embodiments of the present invention, an electronic device is also provided, including the aforementioned magnetic sensor.
[0146] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A magnetic sensor, characterized in that, include: Substrate; A functional thin film layer is formed on the substrate; as well as The metal electrode includes a first electrode and a second electrode, wherein the first electrode completely covers a first end of the functional thin film layer and the second electrode completely covers a second end of the functional thin film layer. The first end and the second end are opposite ends along the horizontal direction of the functional thin film layer; The functional thin film layer comprises: an antiferromagnetic layer, a ferromagnetic layer, and an SOT effect layer sequentially formed on the substrate in a direction away from the substrate; wherein: The antiferromagnetic layer is used to pin the magnetization direction of the ferromagnetic layer by magnetic exchange force to achieve a primary bias. The SOT effect layer is used to perform a secondary bias on the magnetization direction of the ferromagnetic layer when a current is introduced between the first electrode and the second electrode. The primary bias and the secondary bias are used to make the initial angle between the magnetization direction and the current direction of the ferromagnetic layer reach a preset angle value.
2. The magnetic sensor according to claim 1, characterized in that, The preset included angle value is 45°.
3. The magnetic sensor according to claim 1 or 2, characterized in that, The functional thin film layer further includes a transition layer formed between the substrate and the antiferromagnetic layer.
4. The magnetic sensor according to claim 3, characterized in that, The thickness of the antiferromagnetic layer is 1-40 nm.
5. The magnetic sensor according to claim 4, characterized in that, The material constituting the antiferromagnetic layer is FeMn or IrMn.
6. The magnetic sensor according to claim 3, characterized in that, The thickness of the ferromagnetic layer is 1-10 nm.
7. The magnetic sensor according to claim 6, characterized in that, The material constituting the ferromagnetic layer is NiFe.
8. The magnetic sensor according to claim 3, characterized in that, The thickness of the SOT effect layer is 1-10 nm.
9. The magnetic sensor according to claim 8, characterized in that, The material constituting the SOT effect layer is a heavy metal material or a topological insulating material that can generate a spin-orbit effect, wherein the heavy metal material includes at least one of Pt, Ta and W.
10. The magnetic sensor according to claim 3, characterized in that, The thickness of the metal electrode is 10-200 nm.
11. The magnetic sensor according to claim 10, characterized in that, The material constituting the metal electrode is copper or gold.
12. The magnetic sensor according to claim 3, characterized in that, The material of the transition layer is Ta.
13. A method for fabricating a magnetic sensor, used to fabricate the magnetic sensor as described in any one of claims 1-12, characterized in that, The method includes: Provide one of the aforementioned substrates; A patterned functional thin film layer is formed on the substrate; the functional thin film layer includes: an antiferromagnetic layer, a ferromagnetic layer, and a SOT effect layer sequentially formed on the substrate in a direction away from the substrate; and The metal electrode is formed, the metal electrode including a first electrode and a second electrode, the first electrode completely covering a first end of the functional thin film layer, and the second electrode completely covering a second end of the functional thin film layer.
14. The method for preparing a magnetic sensor according to claim 13, characterized in that, A patterned functional thin film layer is formed on the substrate, specifically including: A first photoresist coating is applied to the substrate surface, and the coated photoresist is patterned and developed for the first time to form a functional thin film layer cavity. The functional thin film layer is deposited in the cavity of the functional thin film layer and on the surface of the photoresist after the first development. The photoresist and the functional thin film layer deposited on the photoresist surface are stripped to form a patterned functional thin film layer.
15. The method for preparing a magnetic sensor according to claim 14, characterized in that, The formation of the metal electrode specifically includes: A second photoresist coating is performed on the substrate and the patterned functional thin film layer, and the coated photoresist is patterned a second time and developed a second time. After the second development, a first electrode cavity and a second electrode cavity are formed. Metal electrode material is deposited on the remaining photoresist surface after the second development and in the first electrode cavity and the second electrode cavity; The photoresist and the metal electrode material on the surface of the photoresist are stripped off to form the first electrode and the second electrode.
16. The method for preparing a magnetic sensor according to claim 13, characterized in that, Forming the patterned functional thin film layer on the substrate specifically includes: The functional thin film layer is deposited on the surface of the substrate; A third photoresist coating is performed on the surface of the deposited functional thin film layer, and the coated photoresist is then patterned and developed a third time. The photoresist retained after the third development is used as a mask to etch the deposited functional thin film layer, and the photoresist is removed to form the patterned functional thin film layer; the shape of the photoresist retained after the third development is adapted to the shape of the functional thin film layer.
17. The method for preparing a magnetic sensor according to claim 16, characterized in that, Forming the metal electrode specifically includes: Metal electrode material is deposited on the substrate and the patterned functional thin film layer; A fourth photoresist coating is performed on the surface of the metal electrode material, and the coated photoresist is then patterned and developed a fourth time. Using the photoresist remaining after the fourth development as a mask, the metal electrode material is etched to remove the photoresist and form the first electrode and the second electrode; the shape of the photoresist remaining after the fourth development is adapted to the shape of the first electrode and the second electrode.
18. An electronic device, characterized in that, Including the magnetic sensor as described in any one of claims 1-12.
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Electrically-controlled magnetic anisotropy magnetic random access memory based on topology spinning
CN113410379A