Magnetic detection device and decoding system

Abstract

There is provided a magnetic detection device provided with: a pixel array unit configured by arranging pixel units in an array, each pixel unit including a magnetoresistive element and a detection unit, or by arranging a basic array including a plurality of the pixel units arranged in an array, each pixel unit including a magnetoresistive element and a detection unit; wherein: each magnetoresistive element includes a fixed layer having a fixed magnetization direction, a non-magnetic layer provided on the fixed layer, and a storage layer provided on the non-magnetic layer, and the detection unit detects an external magnetic field based on a change in a resistance value of the magnetoresistive element.

Description

Technical Field

[0001] The present disclosure relates to a magnetic detection device and a decoding system. Background Art

[0002] Magnetic detection devices using principles such as the Hall effect and magnetoresistance effect are widely used due to their ease of use. However, when measuring biomagnetism related to brain activity, heart activity, etc., since the biomagnetism is weak, it is difficult to say that the sensitivity of commonly used magnetic detection devices is sufficient for these measurements. Therefore, in the measurement of biomagnetism related to brain activity, heart activity, etc., generally, a SQUID (superconducting quantum interference device) magnetic detection device utilizing the magnetic quantum effect is usually used.

[0003] However, in a SQUID magnetic detection device, since it is necessary to cool the SQUID magnetic detection device to a very low temperature, the size of the device increases and it is difficult to provide a simple structure. Therefore, there is a need for a magnetic detection device that can perform measurements with high precision with a simple structure. When measuring biomagnetism related to brain activity, heart activity, etc., it is desirable to perform measurements at multiple points on the head surface or chest surface rather than at a single point on the head surface or chest surface. Thus, in Patent Document 1 described below, a magnetocardiogram measurement device (magnetic detection device) is proposed, which can measure magnetocardiogram (magnetic field caused by a weak current generated when the myocardium expands and contracts to pump blood into the body) with higher precision by arranging a plurality of magnetoresistive elements in a matrix.

[0004] Citation List

[0005] Patent Document

[0006] Patent Document 1: JP 2020-156870 A Summary of the Invention

[0007] Technical Problem

[0008] In addition, in the magnetocardiogram measurement device (magnetic detection device) proposed in Patent Document 1 above, the input magnetic field (external magnetic field) in the uniaxial direction is measured by arranging magnetoresistive elements capable of measuring the input magnetic field in the uniaxial direction along the X-axis, Y-axis, and Z-axis, and the input magnetic field in the three-axis directions is measured. However, in the magnetocardiogram measurement device proposed in Patent Document 1, there are problems of unavoidable structural complexity and inconsistency between the magnetic field measured by the magnetoresistive element and the position of the axis.

[0009] Therefore, the present disclosure proposes a magnetic detection device and a decoding system that can measure the input magnetic field in multiple axial directions at matching positions in space and have a simpler structure at the same time.

[0010] Solution to the Problem

[0011] According to the present disclosure, a magnetic detection device including a pixel array unit is provided. The pixel array unit is configured in an array by pixel units each including a magnetoresistive element and a detection unit, or is configured in an array by a basic array including a plurality of the pixel units. In the magnetic detection device, the magnetoresistive element includes: a fixed layer having a fixed magnetization direction; a nonmagnetic layer provided on the fixed layer; and a storage layer provided on the nonmagnetic layer, and the detection unit detects an external magnetic field based on a change in a resistance value of the magnetoresistive element.

[0012] Furthermore, according to the present disclosure, a decoding system is provided, including: a magnetic detection device worn on a user; an encoder; and an arithmetic unit. In the decoding system, the magnetic detection device includes a pixel array unit configured in an array by pixel units each including a magnetoresistive element and a detection unit, or configured in an array by a basic array including a plurality of the pixel units, the magnetoresistive element includes: a fixed layer having a fixed magnetization direction; a nonmagnetic layer provided on the fixed layer; and a storage layer provided on the nonmagnetic layer, the detection unit detects an external magnetic field based on a change in a resistance value of the magnetoresistive element, the encoder obtains the external magnetic field from the magnetic detection device as input data and calculates a feature vector based on the input data, and the arithmetic unit outputs the idea of the user or gives a stimulus to the user based on the feature vector. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic diagram showing a schematic configuration example of a magnetoresistive element according to a first embodiment of the present invention.

[0014] Figure 2 is a schematic diagram showing a more detailed configuration example of a magnetoresistive element according to a first embodiment of the present disclosure.

[0015] Figure 3 is a schematic diagram showing another schematic configuration example of a magnetoresistive element according to a first embodiment of the present disclosure.

[0016] Figure 4 is a diagram showing the direction of an input magnetic field with respect to the storage layer according to a first embodiment of the present disclosure.

[0017] Figure 5 is a diagram showing the relationship between the direction of an input magnetic field and an output signal (residence time difference) in the case where an in-plane magnetization film is used for the storage layer according to a first embodiment of the present disclosure.

[0018] Figure 6 is a plan view showing a schematic configuration example of a magnetoresistive element according to a first embodiment of the present disclosure.

[0019] Figure 7 It is a plan view showing a schematic structural example of another magnetoresistive element according to a first embodiment of the present disclosure.

[0020] Figure 8 It is a plan view showing a schematic structural example of yet another magnetoresistive element according to a first embodiment of the present invention.

[0021] Figure 9 It is a plan view showing a schematic structural example of yet another magnetoresistive element according to a first embodiment of the present invention.

[0022] Figure 10 It is a plan view showing a schematic structural example of yet another magnetoresistive element according to a first embodiment of the present invention.

[0023] Figure 11 It is a plan layout view of a first example of a magnetoresistive element array according to a first embodiment of the present disclosure, which is an array example of magnetoresistive elements for detecting an input magnetic field on one axis (X-axis) in a plane.

[0024] Figure 12 It is a plan layout view of a second example of a magnetoresistive element array according to a first embodiment of the present invention, which is an array example of magnetoresistive elements for detecting an input magnetic field on one axis (Y-axis).

[0025] Figure 13 It is a plan layout view of a third example of an array of magnetoresistive elements according to a first embodiment of the present invention, which is an array example of magnetoresistive elements for detecting an input magnetic field on one axis (Z-axis).

[0026] Figure 14 It is a plan layout view of a fourth example of an array of magnetoresistive elements according to a first embodiment of the present invention, which is an array example of magnetoresistive elements for detecting input magnetic fields on two axes (X-axis and Y-axis) in a plane.

[0027] Figure 15 It is a plan layout view of a fifth example of an array of magnetoresistive elements according to a first embodiment of the present disclosure, which is an array example of magnetoresistive elements for detecting input magnetic fields on two axes (X-axis and Y-axis) in a plane.

[0028] Figure 16 It is a plan layout view of a sixth example of an array of magnetoresistive elements according to a first embodiment of the present invention, which is an array example of magnetoresistive elements for detecting input magnetic fields on three axes (X-axis, Y-axis, and X-axis).

[0029] Figure 17It is a plan layout view of a seventh example of an array of magnetoresistive elements according to a first embodiment of the present invention. This seventh example is an example of an array of magnetoresistive elements that detects an input magnetic field on three axes (X-axis, Y-axis, and X-axis).

[0030] Figure 18 It is a plan layout view of an eighth example of an array of magnetoresistive elements according to a first embodiment of the present disclosure. The eighth example is an example of an array of magnetoresistive elements that detects an input magnetic field on two axes (X-axis and X-axis).

[0031] Figure 19 It is a plan layout view of a ninth example of an array of magnetoresistive elements according to a first embodiment of the present invention. The ninth example is an example of an array of magnetoresistive elements that detects an input magnetic field on two axes (Y-axis and X-axis).

[0032] Figure 20 It is a plan layout view of a tenth example of an array of magnetoresistive elements according to a first embodiment of the present invention. This tenth example is an example of an array of magnetoresistive elements that detects an input magnetic field on three axes (X-axis, Y-axis, and X-axis).

[0033] Figure 21 It is a perspective view of an eleventh example of an array of magnetoresistive elements according to a first embodiment of the present invention. The eleventh example is an example of an array of magnetoresistive elements that detects an input magnetic field on three axes (X-axis, Y-axis, and X-axis).

[0034] Figure 22 It is a process cross-sectional view (part 1) showing an example of a method for manufacturing a magnetoresistive element according to a first embodiment of the present invention.

[0035] Figure 23 It is a process cross-sectional view (part 2) showing an example of a method for manufacturing a magnetoresistive element according to a first embodiment of the present invention.

[0036] Figure 24 It is a process cross-sectional view (part 3) showing an example of a method for manufacturing a magnetoresistive element according to a first embodiment of the present invention.

[0037] Figure 25 It is a process cross-sectional view (part 4) showing an example of a method for manufacturing a magnetoresistive element according to a first embodiment of the present invention.

[0038] Figure 26 It is a process cross-sectional view (part 5) explaining an example of a method for manufacturing a magnetoresistive element according to a first embodiment of the present invention.

[0039] Figure 27 It is a process cross-sectional view (part 6) showing an example of a method for manufacturing a magnetoresistive element according to a first embodiment of the present invention.

[0040] Figure 28It is a process cross-sectional view (part 7) showing an example of a method for manufacturing a magnetoresistive element according to a first embodiment of the present invention.

[0041] Figure 29 It is a process cross-sectional view (part 8) showing an example of a method for manufacturing a magnetoresistive element according to a first embodiment of the present invention.

[0042] Figure 30 It is a process cross-sectional view (part 9) illustrating an example of a method for manufacturing a magnetoresistive element according to a first embodiment of the present invention.

[0043] Figure 31 It is a process cross-sectional view (part 1) showing another example of a method for manufacturing a magnetoresistive element according to a first embodiment of the present invention.

[0044] Figure 32 It is a process cross-sectional view (part 2) showing another example of a method for manufacturing a magnetoresistive element according to a first embodiment of the present invention.

[0045] Figure 33 It is a process cross-sectional view (part 3) showing another example of a method for manufacturing a magnetoresistive element according to a first embodiment of the present invention.

[0046] Figure 34 It is a process cross-sectional view (part 4) showing another example of a method for manufacturing a magnetoresistive element according to a first embodiment of the present invention.

[0047] Figure 35 It is a process cross-sectional view (part 5) showing another example of a method for manufacturing a magnetoresistive element according to a first embodiment of the present invention.

[0048] Figure 36 It is a process cross-sectional view (part 6) showing another example of a method for manufacturing a magnetoresistive element according to a first embodiment of the present invention.

[0049] Figure 37 It is a process cross-sectional view (part 7) showing another example of a method for manufacturing a magnetoresistive element according to a first embodiment of the present invention.

[0050] Figure 38 It is a block diagram showing a schematic configuration example of a magnetic detection device according to a first embodiment of the present disclosure.

[0051] Figure 39 It is a block diagram showing a first example of a pixel unit array according to a first embodiment of the present disclosure.

[0052] Figure 40 It is a block diagram showing a second example of a pixel unit array according to a first embodiment of the present disclosure.

[0053] Figure 41It is a block diagram showing a third example of a pixel unit array according to the first embodiment of the present disclosure.

[0054] Figure 42 It is a block diagram showing a fourth example of a pixel unit array according to the first embodiment of the present disclosure.

[0055] Figure 43 It is a flowchart showing a first example of a write operation of a magnetic detection device according to the first embodiment of the present disclosure.

[0056] Figure 44 It is a timing diagram showing a first example of a write operation of a magnetic field measurement device according to the first embodiment of the present disclosure.

[0057] Figure 45 It is a flowchart showing a second example of a write operation of a magnetic field measurement device according to the first embodiment of the present disclosure.

[0058] Figure 46 It is a timing diagram showing a second example of a write operation of a magnetic field measurement device according to the first embodiment of the present disclosure.

[0059] Figure 47 It is a schematic diagram showing a first example of an output data format of a magnetic field measurement device according to the first embodiment of the present disclosure.

[0060] Figure 48 It is a schematic diagram showing a second example of an output data format of a magnetic field measurement device according to the first embodiment of the present disclosure.

[0061] Figure 49 It is a schematic diagram showing a third example of an output data format of a magnetic field measurement device according to the first embodiment of the present disclosure.

[0062] Figure 50 It is a diagram showing a first circuit configuration example of a pixel unit according to the first embodiment of the present disclosure.

[0063] Figure 51 It is a diagram showing a second circuit configuration example of a pixel unit according to the first embodiment of the present disclosure.

[0064] Figure 52 It is a diagram showing a third circuit configuration example of a pixel unit according to the first embodiment of the present disclosure.

[0065] Figure 53 It is a diagram showing a fourth circuit configuration example of a pixel unit according to the first embodiment of the present disclosure.

[0066] Figure 54 It is a diagram showing a fifth circuit configuration example of a pixel unit according to the first embodiment of the present disclosure.

[0067] Figure 55 is a diagram showing a sixth circuit configuration example of a pixel unit according to the first embodiment of the present disclosure.

[0068] Figure 56 is a diagram showing a first circuit configuration example of a digitizing device according to the first embodiment of the present disclosure.

[0069] Figure 57 is a diagram showing a second circuit configuration example of a digitizing device according to the first embodiment of the present disclosure.

[0070] Figure 58 is a diagram showing a third circuit configuration example of a digitizing device according to the first embodiment of the present disclosure.

[0071] Figure 59 is a diagram showing a fourth circuit configuration example of a digitizing device according to the first embodiment of the present disclosure.

[0072] Figure 60 is a diagram showing a fifth circuit configuration example of a digitizing device according to the first embodiment of the present disclosure.

[0073] Figure 61 is a diagram showing a sixth circuit configuration example of a digitizing device according to the first embodiment of the present disclosure.

[0074] Figure 62 is a diagram showing an operation example of a sixth circuit configuration example of a digitizing device according to the first embodiment of the present disclosure.

[0075] Figure 63 is a diagram showing a seventh circuit configuration example of a digitizing device according to the first embodiment of the present disclosure.

[0076] Figure 64 is a diagram showing a first configuration example of a decoding system according to the second embodiment of the present disclosure.

[0077] Figure 65 is a diagram showing a usage example of a first configuration of a decoding system according to the second embodiment of the present disclosure.

[0078] Figure 66 is a diagram showing a second configuration example of a decoding system according to the second embodiment of the present disclosure. DETAILED DESCRIPTION

[0079] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Note that in this specification and the accompanying drawings, components having substantially the same functional configuration are denoted by the same reference numerals and symbols, and redundant explanations of the components are thus omitted.

[0080] Note that the explanations are given in the following order.

[0081] 1. First Embodiment

[0082] 1.1 Configuration Example of Magnetoresistive Element

[0083] 1.2 Modified Example of Magnetoresistive Element

[0084] 1.3 Configuration Example of Array of Magnetoresistive Elements

[0085] 1.4 Example of Manufacturing Method

[0086] 1.5 Configuration Example of Magnetic Detection Device

[0087] 1.6 Operation Example of Magnetic Detection Device

[0088] 1.7 Output Data Format Example

[0089] 1.8 Circuit Configuration Example of Pixel Unit

[0090] 1.9 Example of Digitization Means

[0091] 2. Second Embodiment

[0092] 2.1 First Configuration Example of Decoding System

[0093] 2.2 Second Configuration Example of Decoding System

[0094] 3. Supplementary

[0095] <<1. First Embodiment>>

[0096] <1.1 Configuration Example of Magnetoresistive Element>

[0097] First, with reference to Figures 1 - 5 the magnetoresistive element 10 and the magnetic detection device 20 of the first embodiment of the present invention will be described in detail. Figure 1 is a schematic diagram showing a schematic configuration example of the magnetoresistive element 10 of this embodiment. Figure 2 is a schematic diagram showing a more detailed structural example of the magnetoresistive element 10 according to this embodiment. Figure 3 is a schematic diagram showing another schematic configuration example of the magnetoresistive element 10 according to this embodiment. In addition, Figure 4 is a diagram showing the direction of the input magnetic field with respect to the storage layer 13 according to this embodiment. Figure 5 is a diagram showing the relationship between the direction of the input magnetic field (external magnetic field) and the output signal (residence time difference) in the case where an in-plane magnetization film is used in the storage layer 13 according to this embodiment.

[0098] First, refer to Figure 1 the magnetoresistive element 10 of this embodiment will be described. AsFigure 1 As shown, the magnetoresistive element 10 includes, for example, a magnetization-fixed layer (fixed layer) 11 with a fixed magnetization direction, a storage layer 13 whose magnetization direction changes according to an input magnetic field, and a nonmagnetic layer 12 disposed between the magnetization-fixed layer 11 and the storage layer 13. Hereinafter, the layers of the magnetoresistive element 10 will be described.

[0099] The magnetization-fixed layer 11 can be a layer that fixes the magnetization direction by combining a ferromagnetic material (such as a cobalt-iron (CoFe) alloy) with an antiferromagnetic material (such as a platinum-manganese (PtMn) alloy or an iridium-manganese (IrMn) alloy). Alternatively, the magnetization-fixed layer 11 can be formed into a structure in which at least two ferromagnetic layers are laminated with an extremely thin ruthenium (Ru) layer, iridium (Ir) layer, etc. With this configuration, the magnetization direction of the magnetization-fixed layer 11 is fixed. In addition, with this configuration, since the ferromagnetic layers are coupled antiparallel to each other, the leakage magnetic field from the magnetization-fixed layer 11 can be reduced.

[0100] The storage layer 13 is formed of a magnetic material having weak magnetic anisotropy, such as a CoFe alloy, a nickel-iron (NiFe) alloy, or a cobalt-iron-boron (CoFeB) alloy, so as to be easily changed with respect to the input magnetic field.

[0101] The nonmagnetic layer 12 can be formed of an insulator such as aluminum oxide (Al 2 O 3 2) or magnesium oxide (MgO). By using such an insulator, current is fed in the direction perpendicular to the film surface, and a large resistance change can be caused in the magnetoresistive element 10 by the tunneling magnetoresistance (TMR) effect.

[0102] In addition, as Figure 1 shown, in the magnetoresistive element 10 according to the present embodiment, the easy axis of magnetic anisotropy (hereinafter, simply referred to as the easy axis) of the storage layer 13 is configured to be parallel to the magnetization direction of the magnetization-fixed layer 11. Then, when the easy axis of the storage layer 13 and the magnetization direction of the magnetization-fixed layer 11 are parallel, according to the direction and magnitude of the input magnetic field, the magnetization direction of the storage layer 13 is restricted to a state close to being parallel to the magnetization direction of the magnetization-fixed layer 11 (hereinafter, simply referred to as the parallel state) or a state close to being antiparallel to the magnetization direction (hereinafter, simply referred to as the antiparallel state). In addition, since the magnetization direction of the storage layer 13 is restricted to two states, the resistance of the magnetoresistive element 10 has two states (high resistance and low resistance).

[0103] Figure 2 and Figure 3 are schematic diagrams showing a more detailed structural example of the magnetoresistive element 10 of the present embodiment. In some cases, Figure 1The easy axis of the storage layer 13 shown in [Figure] is in the in-plane direction of the film, and in other cases, the easy axis of the storage layer 13 is in the direction perpendicular to the film surface. When the magnetization direction of the storage layer 13 is equal to the easy axis, the magnetization is stable. Specifically, Figure 2 is a diagram showing an example of the magnetoresistive element 210E, in which an in-plane magnetization film that is stable when the magnetization direction is in the film plane is used in the storage layer 213. Figure 2 The upper part of [Figure] shows a top view of the magnetoresistive element 210E, Figure 2 The lower part of [Figure] shows a longitudinal sectional view parallel to the major axis direction (the X direction in this example) of the magnetoresistive element 210E. On the other hand, Figure 3 is a diagram showing the magnetoresistive element 210C, in which a perpendicular magnetization film that is stable when the magnetization direction is perpendicular to the film surface (in this example, the Z direction) is used in the storage layer 218. Figure 3 The upper part of [Figure] shows a top view of the magnetoresistive element 210C, Figure 3 The lower part of [Figure] shows a perpendicular sectional view of the magnetoresistive element 210C. In Figure 2 and Figure 3 In the examples shown, as in Figure 1 although the magnetization directions of the storage layers 213 and 218 are variable according to the input magnetic field, the magnetization directions of the magnetization fixing layers 211 and 216 are fixed.

[0104] As Figure 2 shown, the upper surface shape of the magnetoresistive element 210E in which an in-plane magnetization film is used in the storage layer 213 has a line-symmetric shape, which has a longitudinal direction in the in-plane direction and has a straight line perpendicular to the longitudinal direction and passing through the center point as an axis. Figure 2 An example is shown in which the upper surface shape of the magnetoresistive element 210E is an elliptical shape having a major axis in the in-plane direction. In this case, the magnetization direction of the storage layer 213 easily points in the major axis direction. That is, it can be said that the longitudinal direction is the easy axis direction in which the magnetization direction of the storage layer 213 easily points. On the contrary, in Figure 2 In the example shown, the magnetization direction of the storage layer 213 is less likely to point in the short direction, and this direction is called the hard axis direction.

[0105] However, this embodiment is not limited thereto, and the upper surface shape of the magnetoresistive element 210E can be appropriately changed to a polygon having a length direction in the in-plane direction, such as a rectangle. The magnetization direction of the magnetization fixing layer 211 of the magnetoresistive element 210E is set in a direction parallel to the longitudinal direction. In addition, in Figure 2 In the embodiment shown, the nonmagnetic layer 212 is provided between the magnetization fixing layer 211 and the storage layer 213.

[0106] On the other hand, as Figure 3As shown, the upper surface shape of the magnetoresistive element 210C using the perpendicular magnetization film in the storage layer 218 has a point-symmetric shape centered on a central point and having no longitudinal direction in the in-plane direction. Figure 3 An example where the upper surface shape of the magnetoresistive element 210E is a circle having no major axis in the in-plane direction is illustrated. However, this embodiment is not limited thereto, and the upper surface shape of the magnetoresistive element 210E can be appropriately changed to a polygon having no length direction in the in-plane direction, such as a square or a regular hexagon. The magnetization direction of the magnetization fixing layer 216 of the magnetoresistive element 210C is set in a direction perpendicular to the formation surface of the layer. Further, in Figure 3 the embodiment shown, the nonmagnetic layer 217 is provided between the magnetization fixing layer 216 and the storage layer 218.

[0107] Return reference Figure 1 , and the magnetization direction of the storage layer 13 is explained in more detail. When the volume of the storage layer 13 is large, the magnetization of the storage layer 13 is stabilized in the parallel state or the antiparallel state. However, as the volume of the storage layer 13 decreases, the magnetization of the storage layer 13 transitions between the parallel state and the antiparallel state due to the influence of thermal fluctuations.

[0108] Here, the thermal stability index Δ of the state of the storage layer 13 0 uses the magnetic anisotropy energy K u , the volume V of the magnet, the temperature T, and the Boltzmann constant k B is represented by the following expression (1).

[0109] Δ 0 = K u V / k B T…(1)

[0110] Therefore, the inversion probability P that the magnetization direction of the storage layer 13 is inverted during the time t can be represented by the following expression (2). In Expression (2), τ 0 is the relaxation constant.

[0111] P = 1 - exp{-t / τ 0 ·exp(-Δ 0 )}…(2)

[0112] When an input magnetic field is applied to the magnetoresistive element 10, the thermal stability index Δ in the state (S + ) close to the input magnetic field direction + and the thermal stability index Δ in the state (S - ) far from the input magnetic field direction - are different from each other. Specifically, the thermal stability index Δ + in the state close to the input magnetic field direction (S +Greater than the thermal stability index Δ in a state far from the input magnetic field direction - (Δ + >Δ - ). That is, when an input magnetic field is applied to the magnetoresistive element 10, a difference appears between the thermal stability index Δ + and the thermal stability index Δ-. A difference appears between the reversal probability P from state S + to state S - and the reversal probability P from state S - to state S + . Therefore, a difference appears between the residence time of the magnetization of the storage layer 13 in state S + and the residence time of the magnetization of the storage layer 13 in state S - .

[0113] As a result of various studies, the present inventors uniquely found that by dividing the difference between the residence time in state S + and the residence time in state S - by the sum of the residence time in state S + and the residence time in state S - (hereinafter, in this specification, the value S is referred to as the "residence time difference"), the value S obtained can be represented by the following expression (3).

[0114] S = tanh(M s VB || / k B )…(3)

[0115] In the above expression (3), M s represents the saturation magnetization of the storage layer 13, and B || represents the easy-axis component of the input magnetic field B.

[0116] By using the above expression (3), by obtaining the residence time difference S, the component along the easy-axis direction can be detected only from an input magnetic field with any angle.

[0117] Figure 4 And Figure 5 show the relationship between the direction of the input magnetic field and the output signal (residence time difference) S in the case where the in-plane magnetization film is used in the storage layer 213. In Figure 4 and Figure 5 , A represents the case where the direction of the input magnetic field B is parallel to the easy axis, B represents the case where the direction of the input magnetic field B is inclined 60° with respect to the easy axis, and C represents the case where the direction of the input magnetic field B is inclined 90° with respect to the easy axis (i.e., perpendicular). As Figure 5As shown, in A where the direction of the input magnetic field B is equal to the easy axis, the change in the output signal S is the largest. In other words, the sensitivity is the highest. On the contrary, in C where the direction of the input magnetic field B is perpendicular to the easy axis (i.e., equal to the hard axis), the change in the output signal S is zero. In other words, the sensitivity is zero.

[0118] The magnetoresistive elements 210E and 210C configured to have such an easy axis have a directionality of sensitivity to the input magnetic field. Therefore, in the present embodiment, by combining magnetoresistive elements with different easy and hard axis directions, it is possible to detect not only the magnitude of the input magnetic field but also the direction of the input magnetic field.

[0119] <1.2 Variants of Magnetoresistive Elements>

[0120] Next, use Figures 6 - 10 to describe a variant of the magnetoresistive element of the present embodiment. Figures 6 to 10 is a top view showing a part of a variant of the magnetoresistive element of the present embodiment.

[0121] Figure 6 is a top view showing a planar configuration example of a magnetoresistive element (first magnetoresistive element) 210L in which the easy axis is parallel to the lateral direction (X direction) (first direction) in the magnetoresistive element 210E using an in-plane magnetization film having an easy axis in the in-plane direction in the storage layer 213. According to the magnetoresistive element 210L in which the easy and hard axes are parallel to the lateral direction (X direction), it is possible to detect the component in the X direction in the input magnetic field B with high sensitivity.

[0122] Figure 7 is a top view further showing a planar configuration example of a magnetoresistive element (second magnetoresistive element) 210V in which the easy axis in the magnetoresistive element 210E is parallel to the longitudinal direction (Y direction) (second direction). Using the magnetoresistive element 210V in which the easy axis is parallel to the longitudinal direction (Y direction), it is possible to detect the component in the Y direction in the input magnetic field B with high sensitivity.

[0123] Figure 8 is a top view further showing a planar configuration example of the magnetoresistive element 210NW, which is parallel to the easy axis and is inclined 135° counterclockwise with respect to the X direction in the magnetoresistive element 210E (hereinafter also referred to as the -XY direction or the left tilt direction). The magnetoresistive element NW is a variant for supplementing the magnetic field detection in the in-plane direction by the magnetoresistive element 210L and the magnetoresistive element 210V, and can detect the component in the left tilt direction in the input magnetic field B with high sensitivity.

[0124] Figure 9This is a top view showing a planar layout example of a magnetoresistive element 210NE that is parallel to the easy axis and inclined counterclockwise by 45° with respect to the X direction (hereinafter also referred to as the +XY direction or the right tilt direction) in the magnetoresistive element 210E. Similar to the magnetoresistive element NW, the magnetoresistive element NE is a modified example for supplementing the in-plane direction magnetic field detection of the magnetoresistive elements 210L and 210V, and can highly sensitively detect the component in the right tilt direction of the input magnetic field B.

[0125] Figure 10 This is a top view showing a planar layout example of a magnetoresistive element (third magnetoresistive element) 210C that uses a perpendicularly magnetized film having an easy axis in the vertical direction (Z direction) (third direction) in the storage layer 218. By using the magnetoresistive element 210C with the easy axis parallel to the vertical direction (Z direction), the component in the vertical direction (Z direction) of the input magnetic field B can be detected with high sensitivity.

[0126] In this embodiment, by appropriately combining the above magnetoresistive elements 210L, 210V, 210NW, 210NE, and 210C having different easy axis directions, the direction of the input magnetic field can be detected with high sensitivity.

[0127] In addition, this embodiment is not limited to Figures 6 to 10 the shown magnetoresistive elements. For example, magnetoresistive elements with the easy axis parallel to a direction inclined at an angle other than Figures 6 to 10 the shown angle can be used.

[0128] <1.3 Configuration Example of Array of Magnetoresistive Elements>

[0129] Next, with reference to Figures 11 - 21 an arrangement example of the magnetoresistive elements of this embodiment will be described. Figure 11 This is a planar layout diagram showing a first example of an array of magnetoresistive elements according to this embodiment, which is an array example of magnetoresistive elements for detecting an input magnetic field on one axis (X axis) in the detection plane. Figure 12 This is a planar layout diagram showing a second example of an array of magnetoresistive elements according to this embodiment, which is an array example of magnetoresistive elements for detecting an input magnetic field on one axis (Y axis). Figure 13 This is a planar layout diagram showing a third example of an array of magnetoresistive elements according to this embodiment, which is an array example of magnetoresistive elements for detecting an input magnetic field on one axis (Z axis). Figure 14 This is a planar layout diagram showing a fourth example of an array of magnetoresistive elements according to this embodiment, which is an array example of magnetoresistive elements for detecting an input magnetic field on two axes (X axis and Y axis) in the plane. Figure 15It is a plan view showing a fifth example of an array of magnetoresistive elements according to the present embodiment. The fifth example is an example of an array of magnetoresistive elements that detects input magnetic fields on two axes (X-axis and Y-axis) in a plane. Figure 16 It is a plan view showing a sixth example of an array of magnetoresistive elements according to the present embodiment. The sixth example is an example of an array of magnetoresistive elements that detects input magnetic fields on three axes (X-axis, Y-axis, and X-axis). Figure 17 It is a plan view showing a seventh example of an array of magnetoresistive elements according to the present embodiment. The seventh example is an example of an array of magnetoresistive elements that detects input magnetic fields on three axes (X-axis, Y-axis, and X-axis). Figure 18 It is a plan view showing an eighth example of an array of magnetoresistive elements according to the present embodiment. The eighth example is an example of an array of magnetoresistive elements that detects input magnetic fields on two axes (X-axis and X-axis). Figure 19 It is a plan view showing a ninth example of an array of magnetoresistive elements according to the present embodiment. The ninth example is an example of an array of magnetoresistive elements that detects input magnetic fields on two axes (Y-axis and X-axis). Figure 20 It is a plan view showing a tenth example of an array of magnetoresistive elements according to the present embodiment. The tenth example is an example of an array of magnetoresistive elements that detects input magnetic fields on three axes (X-axis, Y-axis, and X-axis). Figure 21 It is a perspective view showing an eleventh embodiment of the arrangement of magnetoresistive elements according to the present embodiment. The 11th embodiment is an example of the arrangement of magnetoresistive elements that detects input magnetic fields on 3 axes (X-axis, Y-axis, X-axis).

[0130] As described above, in the present embodiment, the direction and magnitude of the input magnetic field B are detected with high sensitivity by measuring the dwell time difference (output signal) S. However, in order for a significant dwell time difference to occur, it is necessary to have transitions from state S + to state S - and transitions from state S - to state S + occur at a specific frequency or more. Since these transitions occur probabilistically, there are large temporal fluctuations in the dwell time difference S. Therefore, in the present embodiment, in order to reliably perform the transitions and reduce the fluctuations, it is effective to increase the number of transitions per observation time, that is, to reduce Δ 0 In the present embodiment, for example, it is preferable to set the average inversion time to 10 milliseconds or less.

[0131] In addition, in the present embodiment, in order to suppress the influence of variations, it is sufficient to increase the number of magnetoresistive elements to an average state. For example, by serially or parallely arranging magnetoresistive elements, information related to the difference between the number of magnetoresistive elements in the parallel state and the number of magnetoresistive elements in the antiparallel state is measured, and as the resistance value of the aggregate of magnetoresistive elements, the influence of variations can be reduced. In addition, for example, by integrating the resistance value as an electrical signal over a predetermined time length, or passing the fluctuations through a low-pass filter circuit that removes high-frequency components, the influence of the fluctuations can also be reduced.

[0132] In the present embodiment, in the case of forming an aggregate of magnetoresistive elements, it may also be a structure in which a plurality of magnetoresistive elements are connected in series, a structure in which magnetoresistive elements are connected in parallel, or a structure that combines series connection and parallel connection.

[0133] Note that, in the following description, the Figures 11 - 20 only describes the magnetoresistive elements that constitute the array of magnetoresistive elements. However, the magnetoresistive elements are interconnected by wirings and circuits for detecting a magnetic field (not shown). Note that the details of these wirings and circuits are explained below.

[0134] Figure 11 is a plan layout diagram showing an array 221 of magnetoresistive elements according to the first example of the present embodiment. The array 221 is an example of an array of magnetoresistive elements for detecting an input magnetic field on the X-axis. As Figure 11 shown, in the first example, magnetoresistive elements 210L having high sensitivity to the magnetic field component in the X direction are arranged. As described above, by arranging the magnetoresistive elements 210L that detect the magnetic field component in the X direction with high sensitivity, the magnitude of the input magnetic field B in the X direction can be detected with high sensitivity.

[0135] Figure 12 is a plan layout diagram showing an array 222 of magnetoresistive elements according to the second example of the present embodiment. The array 222 is an example of an array of magnetoresistive elements for detecting an input magnetic field on the Y-axis. As Figure 12 shown, in the second example, magnetoresistive elements 210V having high sensitivity to the magnetic field component in the Y direction are arranged. As described above, by arranging the magnetoresistive elements 210V that detect the magnetic field component in the Y direction with high sensitivity, the magnitude of the input magnetic field B in the Y direction can be detected with high sensitivity.

[0136] Figure 13 is a plan layout diagram showing an array 223 of magnetoresistive elements according to the third example of the present embodiment. The array 223 is an example of an array of magnetoresistive elements for detecting an input magnetic field on the Z-axis. As Figure 13As shown, in the third example, magnetoresistive elements 210C that are highly sensitive to the magnetic field component in the Z direction are arranged. As described above, by providing magnetoresistive elements 210C that highly sensitively detect the magnetic field component in the Z direction, the magnitude of the input magnetic field B in the Z direction can be highly sensitively detected.

[0137] Figure 14 FIG. is a plan layout view of an array 224 of magnetoresistive elements according to a fourth example of the present embodiment. The array 224 is an example of an array of magnetoresistive elements that detect an input magnetic field on two axes (X-axis and Y-axis) in a plane. As Figure 14 shown, in the fourth embodiment, magnetoresistive elements 210L that are highly sensitive to the magnetic field component in the X direction and magnetoresistive elements 210V that are highly sensitive to the magnetic field component in the Y direction are alternately arranged in a checkerboard pattern. As described above, by arranging the magnetoresistive elements 210L and the magnetoresistive elements 210V without deviation, the magnitude and direction of the input magnetic field B in the in-plane direction can be highly sensitively detected. Note that in this example, the array pattern is not limited to the Figure 14 pattern shown in. In this example, as long as the magnetoresistive elements 210L, 210V are arranged evenly as a whole, the arrangement pattern can be appropriately changed, for example, the magnetoresistive elements 210L, 210V are arranged every other row or every other column.

[0138] Figure 15 FIG. is a plan layout view of an array 225 of magnetoresistive elements according to a fifth example of the present embodiment. The array 225 is an example of an array of magnetoresistive elements that detect an input magnetic field on two axes (X-axis and Y-axis) in a plane. As Figure 15 shown, in the fifth example, in addition to the magnetoresistive elements 210L and 210V, magnetoresistive elements 210NW that are highly sensitive to the magnetic field component in the -XY direction and magnetoresistive elements 210NE that are highly sensitive to the magnetic field component in the +XY direction are alternately arranged. As described above, by arranging the magnetoresistive elements 210L, 210V, 210NW, and 210NE without deviation, the magnitude and direction of the input magnetic field B in the in-plane direction can be detected with higher sensitivity. Note that in this example, the array pattern is not limited to the Figure 15 pattern shown in. In this example, as long as the magnetoresistive elements 210L, 210V, 210NW, 210NE are arranged evenly as a whole, the arrangement pattern can be appropriately changed, for example, the magnetoresistive elements 210L, 210V, 210NW, 210NE are arranged every other row or every other column.

[0139] Figure 16 FIG. is a plan layout view of an array 226 of magnetoresistive elements according to a sixth example of the present embodiment. The array 226 is an example of an array of magnetoresistive elements that detect an input magnetic field on three axes (X-axis, Y-axis, and Z-axis). As Figure 16As shown, in the sixth embodiment, based on the arrangement 224 of magnetoresistive elements in the fourth embodiment, in addition to the magnetoresistive elements 210L and 210V in the fourth embodiment, magnetoresistive elements 210C that are highly sensitive to the magnetic field component in the Z direction are alternately arranged. As described above, by arranging the magnetoresistive elements 210L and 210V that highly sensitively detect the magnetic field component in the in-plane direction without deviation and the magnetoresistive elements 210C that highly sensitively detect the magnetic field component in the Z direction, it is possible to highly sensitively detect the magnitude and direction of the input magnetic field B not only in the in-plane direction but also in the Z direction. It should be noted that in this example, the array pattern is not limited to Figure 16 the pattern shown therein. In this example, as long as the magnetoresistive elements 210L, 210V, and 210C are arranged equally as a whole, the arrangement pattern can be appropriately changed, for example, arranging the magnetoresistive elements 210L, 210V, and 210C every other row or every other column.

[0140] Figure 17 FIG. is a plan layout diagram showing an array 227 of magnetoresistive elements according to a seventh example of the present embodiment. The array 227 is an example of an array of magnetoresistive elements that detect an input magnetic field on three axes (X-axis, Y-axis, and Z-axis). As Figure 17 shown, in the seventh example, based on the array 225 of magnetoresistive elements according to the fifth example, in addition to the magnetoresistive elements 210L, 210V, 210NW, and 210NE according to the fifth example, magnetoresistive elements 210C that are highly sensitive to the magnetic field component in the Z direction are alternately arranged. As described above, by arranging the magnetoresistive elements 210L, 210V, 210NW, and 210NE that highly sensitively detect the magnetic field component in the in-plane direction without deviation and the magnetoresistive elements 210C that highly sensitively detect the magnetic field component in the Z direction, it is possible to detect the magnitude and direction of the input magnetic field B with higher sensitivity not only in the in-plane direction but also in the Z direction. It should be noted that in this example, the array pattern is not limited to the pattern shown in Figure 17 therein. In this example, as long as the magnetoresistive elements 210L, 210V, 210NW, 210NE, and 210C are arranged equally as a whole, the arrangement pattern can be appropriately changed, for example, arranging the magnetoresistive elements 210L, 210V, 210NW, 210NE, and 210C every other row or every other column.

[0141] In Figures 11 - 17 the arrangement of the magnetoresistive elements shown, the magnetoresistive elements are formed on the same layer of the semiconductor wafer. On the other hand, in Figures 18 - 20 therein, different types of magnetoresistive elements are formed on different layers of the semiconductor wafer.

[0142] Figure 18is a plan layout diagram showing an array 228 of magnetoresistive elements according to an eighth example of the present embodiment. The array 228 is an example of an array of magnetoresistive elements that detects an input magnetic field on two axes (X-axis and Z-axis) in a plane. As Figure 18 shown, in the eighth example, magnetoresistive elements 210C having high sensitivity to the magnetic field component in the Z direction are arranged in the first layer (in Figure 18 it, represented by a dashed line). In the second layer (in Figure 18 it, represented by a solid line), magnetoresistive elements 210L having high sensitivity to the magnetic field component in the X direction are arranged. As described above, by arranging the magnetoresistive elements 210L and 210C without deviation, the magnitude and direction of the input magnetic field B in the XZ plane can be detected with high sensitivity. Note that in this example, the lamination order of the first layer and the second layer can be opposite to the order shown in the figure.

[0143] Figure 19 is a plan layout diagram showing an array 229 of magnetoresistive elements according to a ninth example of the present embodiment. The array 229 is an example of an array of magnetoresistive elements that detects an input magnetic field on two axes (Y-axis and Z-axis) in a plane. As Figure 19 shown, in the ninth example, magnetoresistive elements 210C having high sensitivity to the magnetic field component in the Z direction are arranged in the first layer (in Figure 19 it, represented by a dashed line). In the second layer (in Figure 19 it, represented by a solid line), magnetoresistive elements 210V having high sensitivity to the magnetic field component in the Y direction are arranged. As described above, by arranging the magnetoresistive elements 210V and 210C without deviation, the magnitude and direction of the input magnetic field B in the YZ plane can be detected with high sensitivity. Note that in this example, the lamination order of the first layer and the second layer can be opposite to the order shown in the figure.

[0144] Figure 20 is a plan layout diagram showing an array 230 of magnetoresistive elements according to a tenth example of the present embodiment. The array 230 is an example of an array that detects an input magnetic field on three axes (X-axis, Y-axis, and Z-axis). As Figure 20 shown, in the tenth example, magnetoresistive elements 210C having high sensitivity to the magnetic field component in the Z direction are arranged in the first layer (in Figure 20 it, represented by a dashed line). In the second layer ( Figure 20Among them, in the magnetic resistance element 210L that has high sensitivity to the magnetic field component in the X direction and the magnetic resistance element 210V that has high sensitivity to the magnetic field component in the Y direction (represented by solid lines) are alternately arranged in a grid pattern. As described above, by arranging the magnetic resistance elements 210L and 210V that detect the magnetic field component in the in-plane direction with high sensitivity and the magnetic resistance element 210C that detects the magnetic field component in the Z direction with high sensitivity without deviation, it is possible to detect not only the magnitude but also the direction of the input magnetic field B in the in-plane direction and in the Z direction with high sensitivity. It should be noted that in this example, the array pattern of the second layer is not limited to Figure 20 the pattern shown in. In this example, as long as the magnetic resistance elements 210L and 210V are arranged equally as a whole, the arrangement pattern can be appropriately changed, for example, the magnetic resistance elements 210L and 210V can be arranged every other row or every other column. In this example, the lamination order of the first layer and the second layer can be the order opposite to the order shown in the figure.

[0145] In the present embodiment, by bonding Figures 11 - 20 the array of one or more magnetic resistance elements shown to another circuit board, the array of magnetic resistance elements can also be reconfigured.

[0146] For example, Figure 21 is a perspective view showing an array 231 of magnetic resistance elements according to the eleventh example of the present embodiment. The array 231 is an example of an array of magnetic resistance elements that detect an input magnetic field on three axes (X-axis, Y-axis, and Z-axis). As Figure 21 shown, in the eleventh example, the array 221 of magnetic resistance elements that detect the input magnetic field on the X-axis, the array 222 of magnetic resistance elements that detect the input magnetic field on the Y-axis, and the array 223 of magnetic resistance elements that detect the input magnetic field on the Z-axis are bonded to another circuit board to configure a new array 231 of magnetic resistance elements. In this way, it is possible to detect the magnitude and direction of the input magnetic field B with higher sensitivity on three axes (X-axis, Y-axis, and Z-axis). In addition, the arrangements of the magnetic resistance elements that detect the input magnetic fields on the X-axis, Y-axis, and Z-axis can be obtained from the same wafer or from different wafers. In addition, the array of magnetic resistance elements that detect the input magnetic field on the Y-axis can be obtained by rotating the array of magnetic resistance elements that detect the input magnetic field on the X-axis by 90 degrees.

[0147] Note that the present embodiment is not limited to an array of magnetic resistance elements having Figures 11 - 21 the form shown.

[0148] <1.4 Example of manufacturing method>

[0149] Next, an example of the manufacturing method of the magnetic resistance element of the present embodiment will be described.

[0150] In the above reference Figures 6 - 10In a modification of the described magnetoresistive element, all of the magnetoresistive elements 210L, 210V, 210NW, and 210NE (modifications of the magnetoresistive element 210E) can be formed and processed in the same process because an in-plane magnetization film is used in the storage layer 213. On the other hand, because a perpendicular magnetization film is used in the storage layer 218, the magnetoresistive element 210C cannot be formed in the same process as that used for the magnetoresistive element 210E and needs to be formed and processed in another process.

[0151] Then, when the magnetoresistive element 210E using an in-plane magnetization film in the storage layer 213 and the magnetoresistive element 210C using a perpendicular magnetization film in the storage layer 218 are formed in the same layer ( Figure 16 and Figure 17 ), and when the magnetoresistive element 210E and the magnetoresistive element 210C are formed in different layers ( Figure 18 、 Figure 19 and Figure 20 ), the magnetoresistive element can be manufactured using the method described below.

[0152] First, an example in which the magnetoresistive element 210E using an in-plane magnetization film in the storage layer 213 and the magnetoresistive element 210C using a perpendicular magnetization film in the storage layer 218 are formed in the same layer will be described. Figures 22 - 30 is a process cross-sectional view showing an example of a method for manufacturing the magnetoresistive element of the present embodiment.

[0153] In this manufacturing method, as Figure 22 shown, on the entire surface of a base substrate 40 including a peripheral circuit, a laminated film 250E in the magnetoresistive element 210E is formed, and in the laminated film 250E, a first layer 251 to be processed into a magnetization fixing layer 211, a second layer 252 to be processed into a nonmagnetic layer 212, and a third layer 253 to be processed into a storage layer 213 are laminated in order. Note that the third layer 253 can be an in-plane magnetization film.

[0154] Subsequently, as Figure 23 shown, for example, the laminated film 250E is processed into a mesa-shaped magnetoresistive element 210E using photolithography technology and etching technology. An upper electrode 214 is formed on the upper surface of the magnetoresistive element 10.

[0155] Subsequently, an insulating layer 241 is formed, for example, by CVD (chemical vapor deposition) method or sputtering method to embed a structure 255E including the magnetoresistive element 210E and the upper electrode 214. Subsequently, as Figure 24 shown, using, for example, photolithography technology and etching technology, a trench A21 for forming the magnetoresistive element 210C is formed in the formed insulating layer 241. Note that the upper surface of the insulating layer 241 can be planarized by, for example, CMP (chemical mechanical polishing).

[0156] Subsequently, as Figure 25 shown, on the magnetoresistive element 210C, a laminated film 250C in which a first layer 256 to be processed into the magnetization fixed layer 216, a second layer 257 to be processed into the nonmagnetic layer 217, and a third layer 258 to be processed into the storage layer 218 are sequentially laminated is formed on the base substrate 40 exposed in the trench A21. Note that the third layer 258 may be a perpendicularly magnetized film. The laminated film 250C formed on the insulating layer 241 can be removed by a lift-off method, CMP, or the like.

[0157] Subsequently, as Figure 26 shown, for example, a mask M21 is formed on the laminated film 250C using photolithography. The laminated film 250C exposed from the mask M21 is etched away using an etching technique such as RIE (reactive ion etching) to form a mesa-shaped magnetoresistive element 210C.

[0158] Subsequently, as Figure 27 shown, an upper electrode 219 is formed on the upper surface of the magnetoresistive element 210C using, for example, a lift-off method.

[0159] Subsequently, as Figure 28 shown, the trench A21 of the insulating layer 241 is filled, for example, using a CVD method or a sputtering method to form an insulating layer 242 covering the structure 255E including the magnetoresistive element 210E and the upper electrode 214 and the structure 255C including the magnetoresistive element 210C and the upper electrode 219. Note that the upper surface of the insulating layer 242 can be planarized by, for example, CMP.

[0160] Subsequently, as Figure 29 shown, an opening A22 for exposing a part of the upper surfaces of the corresponding upper electrodes 214 and 219 is formed using, for example, photolithography and etching techniques.

[0161] Subsequently, as Figure 30 shown, a wire 42 connected to the upper electrode 214 or 219 is embedded in the opening A22. Then, a wiring (not shown) connecting the wire 42 to the power supply voltage VDD is formed on the insulating layer 242, thereby manufacturing the magnetoresistive element of this embodiment.

[0162] Next, an example of a manufacturing method in the case where the magnetoresistive element 210E and the magnetoresistive element 210C are formed in different layers will be described. Figures 31 - 37 is a process cross-sectional view showing an example of the manufacturing method of the magnetoresistive element of this embodiment.

[0163] First, as in the above method, a structure 255E including the magnetoresistive element 210E and the upper electrode 214 is formed on the base substrate 40 including the peripheral circuit.

[0164] Subsequently, for example, an insulating layer 241 is formed using a CVD method or a sputtering method to embed a structure 255E including a magnetoresistive element 210E and an upper electrode 214. Subsequently, as Figure 31 shown, for example, using photolithography techniques and etching techniques, a trench A23 for exposing the lower electrode in the base substrate 40 is formed in the formed insulating layer 241. Note that the upper surface of the insulating layer 241 can be planarized by, for example, CMP.

[0165] Subsequently, as Figure 32 shown, a wiring 243 connected to the lower electrode of the base substrate 40 is embedded in the trench A23 of the insulating layer 241.

[0166] Subsequently, as Figure 33 shown, a laminated film 250C is formed on the insulating layer 241, in which a first layer 256 to be processed into a magnetization fixing layer 216, a second layer 257 to be processed into a non-magnetic layer 217, and a third layer 258 to be processed into a storage layer 218 in a magnetoresistive element 210C are laminated in this order. Note that the third layer 258 can be a perpendicular magnetization film.

[0167] Subsequently, a mask M23 is formed on the laminated film 250C using, for example, photolithography. The laminated film 250C exposed from the mask M23 is dug out using an ng technique such as RIE to form a mesa-shaped magnetoresistive element 210C. Subsequently, as Figure 34 shown, an upper electrode 219 is formed on the upper surface of the magnetoresistive element 210C using, for example, a lift-off method.

[0168] Subsequently, as Figure 35 shown, an insulating layer 244 is formed using a CVD method or a sputtering method to embed a structure 255C including a magnetoresistive element 210C and an upper electrode 219. Note that the upper surface of the insulating layer 244 can be planarized by, for example, CMP.

[0169] Subsequently, as Figure 36 shown, an opening A24 for exposing a part of the upper surfaces of the corresponding upper electrodes 214 and 219 is formed using, for example, photolithography techniques and etching techniques.

[0170] Subsequently, as Figure 37 shown, a wire 245 connected to the upper electrode 214 or 219 is embedded in the opening A24. Thereafter, a wiring (not shown) for connecting the wiring 245 to a power supply voltage VDD is formed on the insulating layer 244, thereby manufacturing a magnetoresistive element according to the present embodiment.

[0171] <1.5 Configuration Example of Magnetic Detection Device>

[0172] (Magnetic Detection Device)

[0173] Next, with reference toFigure 38 A structural example of the magnetic detection device according to the present embodiment will be described. Figure 38 It is a block diagram showing a schematic configuration example of the magnetic detection device according to the present embodiment.

[0174] As Figure 38 shown, the magnetic detection device 20 mainly includes a control unit 21, a vertical scanning unit (decoder) 22, a horizontal scanning unit (selector + interface) 23, and a pixel array (pixel array unit) 24.

[0175] The pixel array 24 is configured by pixel units 25 arranged in an array of M rows and N columns. Here, M and N are 1 or 2 or greater. The vertical scanning unit 22 is connected to row selection signal lines (LS) 26 extending in the row direction of the pixel array 24. The row selection signal lines 26 are wirings for one or more rows of the pixel array 24 and are connected to the corresponding pixel units 25 in the pixel array 24. The horizontal scanning unit 23 is connected to vertical signal lines (VSL) 27 extending in the column direction of the pixel array 24. The vertical signal lines 27 are one or more wirings for the columns of the pixel array 24 and are connected to the corresponding pixel units 25 in the pixel array 24. The horizontal scanning unit 23 is connected to a data output line (DL) 28 and outputs the detected magnetic field information as output data.

[0176] Input signals 30 of control signals, synchronization signals, and clock signals are input to the control unit 21. The format of the control signal can be a format such as 12C, I3C, SPI, or GPIO. The synchronization signal can be generated inside the control unit 21 instead of being input from the outside. Instead of being input from the outside, the clock signal can be generated internally by incorporating an oscillator in the control unit 21.

[0177] The control unit 21 controls the magnetic detection device 20 by outputting a row address to the vertical scanning unit 22, a column address to the horizontal scanning unit 23, and other necessary signals to the vertical scanning unit 22, the horizontal scanning unit 23, and the pixel unit 25 according to the input signal 30.

[0178] The decoder of the vertical scanning unit 22 vertically scans the pixel array 24 and sets only the row selection signal specified by the row address input from the control unit 21 to be enabled.

[0179] The selector of the horizontal scanning unit 23 horizontally scans the pixel array 24, selects a specific signal specified by the column address input from the control unit 21 among the vertical signals input in parallel from the pixel units 25, and provides the selected signal for output. The interface of the horizontal scanning unit 23 converts the signal selected by the selector of the horizontal scanning unit 23 into a predetermined format (serial, parallel, compromise, etc.) and outputs the converted signal to the data output line 28.

[0180] The data output line 28 of the magnetic detection device 20 is connected to an information processing device 29 such as a computer, a smart phone, and a dedicated electronic device, whereby a magnetic field-related image based on the measurement result of the magnetic detection device 20 can be displayed. In addition, the magnetic field-related image may be a magnetic field image generated from the data detected by the magnetic detection device 20, or may be an image after arbitrary transformation operation processing.

[0181] The basic array pattern 31 including the pixel unit 25 or a plurality of pixel units 25 (see Figure 39 ) includes a plurality of magnetoresistive elements 10, and the resistance value of the magnetoresistive element 10 changes according to the intensity and direction of the input magnetic field. As described above, the magnetoresistive element 10 has a hard axis in which the magnetization direction of the storage layer 13 is more likely to point than other directions and a hard axis in which the magnetization direction of the storage layer 13 is less likely to point than other directions. In the present embodiment, the easy axis directions of the magnetoresistive elements 10 included in the pixel unit 25 or the basic array pattern 31 are different from the easy axis directions of the magnetoresistive elements 10 included in the pixel unit 25 or the basic array pattern 31. Therefore, in the present embodiment, it is possible to detect the magnitudes of the input magnetic fields B in two or more axial directions with high sensitivity at spatially consistent positions.

[0182] Note that the basic array pattern 31 including the pixel unit 25 or a plurality of pixel units 25 (see Figure 39 ) may include different types of magnetoresistive elements 10 formed in different layers of the semiconductor wafer shown in Figures 18 - 20 .

[0183] In addition, the pixel unit 25 includes a reading circuit. The reading circuit outputs a reading signal to the vertical signal line 27 based on the enable setting of the row selection signal line 26. The pixel unit 25 may include a reading signal holding unit (not shown) for holding the reading signal. The pixel unit 25 may include a circuit configuration including a resistor, a comparator, a transistor, and a capacitor as a circuit for reading the change in the resistance value of the magnetoresistive element 10. In the present embodiment, by using the detection circuit, it is possible to measure the time (first residence time) when the magnetoresistive element 10 is in the parallel state and the time (second residence time) when the magnetoresistive element 10 is in the antiparallel state, that is, the time when the magnetoresistive element 10 is in the high-resistance state and the time when the magnetoresistive element 10 is in the low-resistance state, and calculate the difference between these times, that is, the residence time difference S. Then, in the present embodiment, according to the calculated residence time difference S, it is possible to detect only the component along the easy axis direction of the magnetoresistive element 10 determined by the magnetization direction of the magnetization fixing layer 11 of the magnetoresistive element 10 from the input magnetic field at any angle. In addition, in the present embodiment, since the pixel unit 25 is previously associated with the coordinate information indicating the position on the pixel array 24, the signal output from the pixel unit 25 can be associated with the coordinate information.

[0184] Therefore, in the present embodiment, the magnetic detection device 20 adopts the above structure and can output data related to the measurement result of the magnetic field in a specific direction in relation to the coordinate information. The information processing device 29 can display a magnetic field-related image.

[0185] In addition, in the present embodiment, when the pixel unit 25 includes a plurality of magnetoresistive elements 10 of the same type, the detection circuit can also calculate the input magnetic field based on the difference between the cumulative value of the time of the parallel state and the cumulative value of the time of the antiparallel state of each of the plurality of magnetoresistive elements 10.

[0186] Since the magnetization direction of the storage layer 13 is limited to two states, i.e., the parallel state and the antiparallel state, in the present embodiment, it is possible to measure at least one of the time when the magnetoresistive element 10 is in the parallel state and the time when the magnetoresistive element 10 is in the antiparallel state, and the residence time difference S can be calculated based on this time.

[0187] Furthermore, in the present embodiment, the structure of the magnetic detection device is not limited to Figure 38 the example shown.

[0188] (Array example)

[0189] Subsequently, with reference to Figures 39 - 42 the array example of the pixel units of the pixel array 24 will be described in detail. Figure 39 FIG. is a block diagram showing a first example of the pixel unit array according to the present embodiment.

[0190] Figure 40 FIG. is a block diagram showing a second example of the array of pixel units according to the present embodiment. Figure 41 FIG. is a block diagram showing a third example of the pixel unit array according to the present embodiment. Figure 42 FIG. is a block diagram showing a fourth example of the pixel unit array according to the present embodiment.

[0191] In addition, in the following description, the pixel unit 25 includes one magnetoresistive element 10, or a plurality of magnetoresistive elements 10 of the same type or different types that are recognized at a specified coordinate point of the pixel array 24 of the magnetic detection device 20.

[0192] Figure 39 FIG. is a diagram showing a first example of the array of pixel units according to the present embodiment. One pixel unit 25 includes an array of one type of magnetoresistive element 10. In the pixel array 24, the basic array pattern 31 formed by a plurality of pixel units 25 arranged in an array is further arranged in an array. That is, the basic array pattern 31 may include pixel units of a plurality of types of magnetoresistive element types grouped for each type of magnetoresistive element 10.

[0193] Specifically, inFigure 39 In the example shown, the lowermost left pixel unit 25A of the pixel array 24 includes the array 222 of the above-described magnetoresistive elements. The pixel unit 25B and the pixel unit 25C adjacent to the pixel unit 25A contain the array 221 of the above-described magnetoresistive elements. The pixel unit 25D adjacent to the pixel unit 25B and the pixel unit 25C includes the array 222 of the above-described magnetoresistive elements. As described above, in this example, the basic array pattern 31 is configured by an array of 2×2 pixel units. The remaining pixel units 25 include the array 221 of magnetoresistive elements or the array 222 of magnetoresistive elements obtained by repeating the basic array pattern 31. As described above, the arrangement 221 of magnetoresistive elements can detect the magnitude of the input magnetic field B in the X direction with high sensitivity, and the arrangement 222 of magnetoresistive elements can detect the magnitude of the input magnetic field B in the Y direction with high sensitivity. Therefore, Figure 39 the array of pixel units shown can achieve biaxial magnetic field detection.

[0194] Figure 40 is a diagram showing a second example of the array of pixel units according to the present embodiment. One pixel unit 25 includes an array of a type of magnetoresistive element 10. In the pixel array 24, the basic array pattern 31 formed by a plurality of pixel units 25 arranged in an array is further arranged in an array. That is, the basic array pattern 31 may include pixel units of a plurality of types of magnetoresistive element types grouped for each type of magnetoresistive element 10.

[0195] Specifically, in Figure 40 the example shown, the lowermost left pixel unit 25A of the pixel array 24 includes the array 223 of the above-described magnetoresistive elements, and the pixel unit 25B adjacent to the pixel unit 25A includes the array 222 of the above-described magnetoresistive elements. Other pixel units 25C adjacent to the pixel unit 25A include the array 221 of the above-described magnetoresistive elements, and the pixel unit 25B and the pixel unit 25D adjacent to the pixel unit 25C include the array 223 of the above-described magnetoresistive elements. As described above, in this example, the basic array pattern 31 is configured by an array of 2×2 pixel units. The remaining pixel units 25 include the array 221 of magnetoresistive elements, the array 222 of magnetoresistive elements, or the array 223 of magnetoresistive elements, where the basic array pattern 31 is repeated. As described above, the arrangement 221 of magnetoresistive elements can detect the magnitude of the input magnetic field B in the X direction with high sensitivity, and the arrangement 222 of magnetoresistive elements can detect the magnitude of the input magnetic field B in the Y direction with high sensitivity. In addition, the array 223 of magnetoresistive elements can detect the magnitude of the input magnetic field B in the Z direction with high sensitivity. Therefore, Figure 40 the pixel unit array shown in can achieve triaxial magnetic field detection.

[0196] Figure 41It is a diagram showing a third example of a pixel unit array according to the present embodiment. One pixel unit 25 includes an array of a kind of magnetoresistive element 10. In the pixel array 24, a basic array pattern 31 formed by a plurality of pixel units 25 arranged in an array is further arranged in an array. That is, the basic array pattern 31 may include pixel units of a plurality of kinds of magnetoresistive element kinds grouped for each kind of magnetoresistive element 10.

[0197] Specifically, in Figure 41 the example shown, the lowermost left pixel unit 25A of the pixel array 24 includes the above-described array 228 of magnetoresistive elements, and the pixel unit 25B and the pixel unit 25C adjacent to the pixel unit 25A include the above-described array 229 of magnetoresistive elements. The pixel unit 25D adjacent to the pixel unit 25B and the pixel unit 25C includes the above-described array 228 of magnetoresistive elements. As described above, in this example, the basic array pattern 31 is configured by an array of 2×2 pixel units. The remaining pixel units 25 include the array 228 of magnetoresistive elements or the array 229 of magnetoresistive elements obtained by repeating the basic array pattern 31. As described above, the arrangement 228 of magnetoresistive elements can highly sensitively detect the magnitude and direction of the input magnetic field B in the XZ plane direction, and the arrangement 229 of magnetoresistive elements can highly sensitively detect the magnitude of the input magnetic field B in the YZ plane direction. Therefore, Figure 41 the array of pixel units shown in can achieve three-axis magnetic field detection.

[0198] Figure 42 It is a diagram showing a fourth example of an array of pixel units according to the present embodiment. The pixel array 24 includes pixel units 25 each containing an array of one type of magnetoresistive element 10. In Figure 42 the example shown, the array 226 of magnetoresistive elements, the array 227 of magnetoresistive elements, the array 230 of magnetoresistive elements, and the array 231 of magnetoresistive elements can be selected as the array of magnetoresistive elements 10. When the array 226 of magnetoresistive elements is selected as the array of magnetoresistive elements, Figure 42 the array of pixel units shown can achieve two-axis magnetic field detection. When an array of magnetoresistive elements other than the array 226 is selected, Figure 42 the array of pixel units shown can achieve three-axis magnetic field detection. By adopting Figure 42 the array of pixel units shown, the magnetic detection device 20 can improve the resolution of the magnetic field-related image.

[0199] It should be noted that in the present embodiment, the array of pixel units of the pixel array 24 is not limited to Figures 39 - 42 the example shown in.

[0200] <1.6 Operation Example of Magnetic Detection Device>

[0201] Next, with reference toFigures 43 - 46 Describe the operation example of the magnetic detection device 20 of this embodiment.

[0202] Figure 43 and Figure 44 are respectively a flowchart and a timing diagram showing a first operation example of the magnetic detection device 20 according to this embodiment. This operation example is the same as the case where the magnetic field detection of the magnetoresistive element 10 is performed as needed at the scanning time described later. It should be noted that in the operation example, as Figure 44 shown, various control signals are generated using a clock signal set as a time reference, and a selection signal for selecting a row to be read is generated based on the control signal.

[0203] As Figure 43 shown, first, the power is turned on (step S101). When the power is turned on, power is supplied to the pixel unit 25, and the magnetoresistive element (MTJ) 10 included in the pixel unit 25 detects the input magnetic field, so the resistance value of the magnetoresistive element 10 changes (step S102). Then, according to the change in the resistance value of the magnetoresistive element 10, a read signal is generated using the read circuit included in the pixel unit 25 (step S103).

[0204] Subsequently, as Figure 43 shown, when the magnetic detection device 20 receives a synchronization signal (step S104), the read row is initialized and the counter R is set to 1 (step S105). Then, the head (H) indicating the read head is output (step S106). The row specified by the counter R is selected by the vertical scanning unit 22, and the selected row selection signal line 26 is enabled (step S107).

[0205] Subsequently, as Figure 44 shown, the read signal as the read result of the pixel unit 25 connected to the selected row selection signal line 26 is output to the vertical signals VSL_1 to VSL_N as the vertical signals V_R_1 to V_R_N (step S108). Here, R is the value of the counter R, and V_i_j is the read data of the pixel unit 25 in the i-th row and the j-th column.

[0206] Subsequently, as Figure 44 shown, the horizontal scanning unit 23 sequentially outputs the vertical signal V_R_C to the data line DL as the output data D_R_C based on the column counter C. Here, C is the value of the counter C, and D_i_j is the output data of the pixel unit 25 in the i-th row and the j-th column. At this time, the horizontal scanning unit 23 can convert the vertical signal into output data according to any conversion operation using the image output interface unit. By the horizontal scanning unit 23 scanning the column counter C, this data output is performed for all pixel units 25 connected to the selected row selection signal line 26 (step S109).

[0207] Subsequently, the counter R is incremented (step S110), and the value of the counter R is compared with the number of lines M (step S111). When R > M (step S111; YES), a footer indicating the end of reading is output, and the reading ends (step S112). When R ≤ M (step S111; NO), the process returns to the process in step S107 to read the next line.

[0208] As described above, the output data of all pixel units 25 is output. In addition, the method of generating the selection signal can also vary according to the control signal received by the magnetic detection device 20. For example, various modifications can be adopted, such as scanning only any one of the X-axis, Y-axis, and Z-axis, or scanning the X-axis, Y-axis, and Z-axis in sequence.

[0209] In Figure 43 and Figure 44 In the first operation example of the magnetic detection device 20 of the present embodiment shown, the read signals from the two-dimensionally arranged pixel units 25 are scanned based on the synchronization signal and output in association with the coordinate information. Therefore, the information processing device 29 can perform information processing, such as image display.

[0210] Figure 45 and Figure 46 are a flowchart and a time chart showing a second operation example of the magnetic detection device 20 according to the present embodiment. This operation example corresponds to the case where magnetic field detection of a plurality of pixel units is performed simultaneously at a predetermined timing. In Figure 45 In the flowchart of, it is assumed that the power is first turned on.

[0211] First, as Figure 45 shown, the magnetic detection device 20 receives a synchronization signal (step S201). Subsequently, the operations in step S202 and step S203 are performed. However, since the steps are the same as steps S102 and S103 in Figure 43 above, the explanation of the steps is omitted here. Next, the read signal generated in the pixel unit 25 is held in a read signal holding unit (not shown) included in the pixel unit 25 (step S204).

[0212] Subsequently, the operations in step S205 and step S206 are performed. However, since the steps are the same as steps S105 and S106 in Figure 43 above, the description of the steps is omitted here. Subsequently, the vertical scanning unit 22 selects the row specified by the counter R and enables the selected row selection signal line 26 (step S207).

[0213] As Figure 46As shown, the read signal held in the read signal holding unit of the pixel unit 25 connected to the selected row selection signal line 26 is output as vertical signals V_R_1 to V_R_N to the vertical signals VSL_1 to VSL_N (step S208). Here, R is the value of the counter R, and V_i_j is the read data of the pixel unit 25 at the i-th row and j-th column.

[0214] Subsequently, as Figure 46 shown, the horizontal scanning unit 23 sequentially outputs the vertical signal V_R_C to the data line DL as the output data D_R_C based on the column counter C. Here, C is the value of the counter C, and D_i_j is the output data of the pixel unit 25 at the i-th row and j-th column. At this time, the horizontal scanning unit 23 can convert the vertical signal into the output data according to any conversion operation using the image output interface unit. By scanning the column counter C by the horizontal scanning unit 23, this data output is performed for all the pixel units 25 connected to the selected row selection signal line 26 (step S209).

[0215] Subsequently, the counter R is incremented (step S210), and the value of the counter R is compared with the number of rows M (step S211). In the case where R > M (step S211; yes), a footer indicating the end of reading is output, and the reading ends (step S212). In the case where R ≤ M (step S211; no), in order to read the next row, the process returns to step S207.

[0216] As described above, the output data of all the pixel units 25 is output. In addition, the method of generating the selection signal can also be changed according to the control signal received by the magnetic detection device 20. For example, various modifications can be adopted, such as scanning only any one of the X-axis, Y-axis, and Z-axis, or scanning the X-axis, Y-axis, and Z-axis in sequence.

[0217] According to Figure 45 and Figure 46 shown, in the second operation example of the magnetic detection device 20 according to the present embodiment, in addition to the functions and effects of the above-described first operation example, it is also possible to ensure the simultaneity of the measured magnetic field by holding the read signals from the two-dimensionally arranged pixel units 25 according to the synchronization signal.

[0218] In addition, the present embodiment is not limited to Figures 43 - 46 the operation of the magnetic detection device 20 shown.

[0219] <1.7 Output Data Format Example>

[0220] Next, with reference to Figures 47 - 49 the output data format example of the magnetic detection device 20 of the present embodiment will be described. Figure 47This is an example of the first output data format of the magnetic detection device 20 of the present embodiment. Figure 48 This is an example of the second output data format of the magnetic detection device 20 of the present embodiment. Figure 49 This is an example of the third output data format of the magnetic detection device 20 according to the present embodiment. In Figures 47 - 49 , #R represents the number of rows, #C represents the number of rows, Bx represents the X-axis component of the magnetic field, By represents the Y-axis component of the magnetic field, and Bz represents the Z-axis component of the magnetic field.

[0221] Figure 47 This is an example of the first output data format of the magnetic detection device 20 of the present embodiment. In the first output data format example, three read operations are continuously performed to detect the three-axis magnetic field components. Therefore, the magnetic field measurement data of each axis can be sent to the information processing device 29.

[0222] Figure 48 This is an example of the second output data format of the magnetic detection device 20 of the present embodiment. Different from the example shown in Figure 47 , in the second output data format example, one read operation is performed to detect the three-axis magnetic field components. Therefore, the magnetic field measurement data of each axis can be sent to the information processing device 29.

[0223] Figure 49 Shows an example of the third output data format of the magnetic detection device 20 according to the present embodiment. Different from the examples shown in Figure 47 and Figure 48 , in the third output data format example, the three-axis magnetic field components are output together. Therefore, when performing simultaneous reading focusing on the X-axis, Y-axis, and Z-axis, since it is not necessary to accumulate data for one frame, memory hardware can be saved.

[0224] It should be noted that in the output data format example shown in Figures 47 - 49 , if the information processing device 29 permits omission, two or one of the line numbers #R and #C can be omitted.

[0225] It should be noted that the present embodiment is not limited to the output data format example shown in Figures 47 to 49 .

[0226] <Circuit configuration example of 1.8 pixel units>

[0227] Next, with reference to Figures 50 - 55 , a circuit configuration example of the pixel unit of the magnetic detection device 20 according to the present embodiment will be described. Figure 50 This is the first circuit configuration example of the pixel unit 25 according to the present embodiment. Figure 51 This is the second circuit configuration example of the pixel unit 25 according to the present embodiment. Figure 52is a third circuit configuration example of the pixel unit 25 according to the present embodiment. Figure 53 is a fourth circuit configuration example of the pixel unit 25 according to the present embodiment. Figure 54 is a fifth circuit configuration example of the pixel unit 25 according to the present embodiment. Figure 55 is a sixth circuit configuration example of the pixel unit 25 according to the present embodiment.

[0228] Figure 50 and Figure 51 are the first and second circuit configuration examples of the pixel unit 25 according to the present embodiment. In Figure 50 and Figure 51 of the pixel unit 25, all the magnetoresistive elements 10 are connected in parallel. Therefore, Figure 50 and Figure 51 the first circuit configuration example and the second circuit configuration example in are suitable when the array of the magnetoresistive elements 10 included in the pixel unit 25 includes one type of magnetoresistive element 10. In addition, in Figure 50 and Figure 51 of the pixel unit 25, the magnetoresistive elements 10 are shown as being connected in parallel. However, this circuit configuration is not limited thereto. For example, all the magnetoresistive elements 10 of the pixel unit 25 may be connected in series, or groups formed by connecting a plurality of magnetoresistive elements 10 in series may be connected in parallel. Then, the above detection circuit calculates the input magnetic field based on the resistance values of such arrangements of the magnetoresistive elements 10.

[0229] In Figure 50 , the magnetoresistive elements 10 connected in parallel and the bias device are connected in series to communicate the power supply voltage and the ground voltage. Here, as the bias mechanism, for example, a series resistor R4 can be used. In Figure 50 , the voltage (read signal) generated by the magnetoresistive elements 10 connected in parallel and the bias device is output to the vertical signal line 27 via the buffer B1 and the row selection switch SW1. In Figure 50 in the circuit configuration example of the pixel unit 25, a filter device (for example, a capacitor) F1 can be added. In Figure 50 , a buffer B1 is provided for driving the vertical signal line 27. Note that in this specification, the buffer B1 is a circuit configured to be able to drive a predetermined load and means a circuit having a gain of approximately 1.

[0230] According to Figure 50 in the circuit configuration example of the pixel unit 25, the read signal of the selected pixel unit 25 can be output. In Figure 50In the circuit configuration, even in the state before the filter device F1 is added, the filter is pseudo-constructed by the resistance of the magnetoresistive element 10 itself, the bias device (resistor R4), the parasitic capacitance of the wiring, and the input capacitance of the buffer B1. Therefore, the read signal is smoothed by such a pseudo-filter. In addition, by adding the filter device F1, the smoothing ability of the read signal can be further improved.

[0231] In Figure 51 in addition to Figure 50 the circuit of Figure 51 a reference voltage generation device is also provided. The reference voltage generation device has a bridge structure composed of resistors R1, R2, and R4. In addition, in

[0232] According to Figure 51 the circuit configuration example of the pixel unit 25 in

[0233] Figures 52 - 55 is the third to sixth circuit configuration examples of the pixel unit 25 according to the present embodiment. In Figures 52 - 55 the pixel unit 25 of Figures 52 - 55 the magnetoresistive element 10 is divided into a plurality of groups, and the magnetoresistive elements 10 belonging to each group are connected in parallel. Therefore,

[0234] In Figure 52 for each group of magnetoresistive elements 10, a circuit structure the same as that of Figure 50 is provided. However, a circuit structure the same as that shown in Figure 51 can also be provided for each group of magnetoresistive elements 10. In Figure 52 the number of row selection signal lines 26 provided is equal to the number of groups of the magnetoresistive elements 10. In this structure, the above detection circuit calculates the input magnetic field for each group according to the resistance value of the magnetoresistive element 10. Then, Figure the circuit structure of

[0235] According to ​The circuit structure example of the pixel unit 25 in [description] has the effect of partially stopping the magnetoresistive element 10 to reduce power consumption in the case of a pixel unit 25 including only the same type of magnetoresistive element 10. On the other hand, in the case of a pixel unit 25 including multiple types of magnetoresistive elements 10, according to ​ The circuit structure example of the pixel unit 25 can output magnetic field detection signals in each direction.

[0236] In ​ For each group of magnetoresistive elements 10, a circuit structure same as ​ is provided. However, a circuit structure same as that shown in ​ can also be provided for each group of magnetoresistive elements 10. Different from ​ , in ​ , a selection device including a magnetoresistive element selection switch SW2 connected to the magnetoresistive element 10 is provided before the buffer B1. In ​ , a row selection switch SW1 configured to be turned on based on the logical sum of multiple different row selection signals is provided between the buffer B1 and the vertical signal line 27.

[0237] According to the circuit configuration example of the pixel unit 25 in ​ , since the number of buffers B1 is one compared to the circuit configuration example of the pixel unit 25 in ​ , the circuit layout area and power consumption can be reduced.

[0238] In ​ , the circuit configuration is the same as that in ​ . However, in addition, a sampling hold (S / H) means that a SH1 for providing a hold signal for each group of magnetoresistive elements 10 and a sampling hold pre-read reset switch SW3 are provided, and the measurement timing can be determined externally. For each group of magnetoresistive elements 10, a sampling pulse for determining the measurement timing is given.

[0239] According to the circuit structure example of the pixel unit 25 in ​ , in each group of magnetoresistive elements 10, when the sampling pulses are the same, the simultaneity of measurement is ensured, and in each group of magnetoresistive elements 10, when the sampling pulses are different, there is an effect of being able to obtain time-series data. ​ The circuit configuration example of the pixel unit 25 has a function of holding read data, and thus is suitable for ​ and ​ the second operation example of the magnetic detection device 20 of the present embodiment shown.

[0240] In ​ , the circuit configuration is the same as that in ​The circuit configurations are the same. However, instead of setting the number of row selection signal lines 26 to be equal to the number of groups of magnetoresistive elements 10, the number of vertical signal lines 27 is set to be equal to the number of groups of magnetoresistive elements 10. Then, in ​ one vertical signal line 27 is connected to the magnetoresistive elements 10 of a predetermined part of a group of pixel units 25.

[0241] According to ​ the circuit structure example of the pixel unit 25 in, in the case of the pixel unit 25 having a plurality of types of magnetoresistive elements 10, there is an effect of being able to ensure the simultaneity of measurement and improving the speed by parallel reading.

[0242] In addition, in the present embodiment, the circuit structure of the pixel unit 25 of the magnetic detection device 20 is not limited to ​ the example shown.

[0243] <1.9 Digital Representation Example>

[0244] Next, with reference to ​ the circuit configuration example of the digital components of the present embodiment will be described. ​ is the first circuit configuration example of the digital device according to the present embodiment. ​ is the second circuit configuration example of the digital device according to the present embodiment. ​ is the third circuit configuration example of the digital device according to the present embodiment. ​ is the fourth circuit configuration example of the digital device according to the present embodiment. ​ is the fifth circuit configuration example of the digital device according to the present embodiment. ​ is the sixth circuit configuration example of the digital device according to the present embodiment. ​ is the operation example of the sixth circuit configuration example. In addition, ​ is the seventh circuit configuration example of the digital device according to the present embodiment.

[0245] ​ is the first circuit configuration example of the digital device according to the present embodiment. In ​ the horizontal scanning unit 23 includes an analog / digital converter (ADC) (conversion unit) 50. In the configuration example, after the horizontal scanning unit 23 selects one from a plurality of vertical signal lines 27, the analog signal of the vertical signal line 27 is converted into a digital signal (digital value) by the ADC 50 and output to the data output line 28 through the interface 51.

[0246] According to ​ the digital device, the pixel unit 25 can extract the output of the measured input magnetic field as a digital signal.

[0247] ​ is a second circuit configuration example of the digital device according to the present embodiment. In ​ , the horizontal scanning unit 23 includes analog / digital converters (ADCs) 50 equal in number to the plurality of vertical signal lines 27. In this configuration example, the analog signals transmitted from the pixel unit 25 via the plurality of vertical signal lines 27 are converted into digital signals in parallel by the plurality of ADCs 50, and are output to the data output line 28 via the interface 51 in sequence from the selected ones.

[0248] According to Figure 57 the digital device in, the frame rate of the output image is improved by the multi-parallelization of the ADCs 50.

[0249] Figure 58 is a third circuit configuration example of the digital device according to the present embodiment. In Figure 58 , the pixel unit 25 includes one ADC 50 and converts the analog read signal into a digital read signal in the pixel unit 25. Then, the converted signal is output to the vertical signal line 27 having a bus width corresponding to the resolution of the ADC 50.

[0250] Using Figure 58 the digital device in, since the long-distance wiring for the output of the pixel unit 25 can perform digital transmission, the noise superimposed in the analog signal transmission can be reduced.

[0251] Figure 59 is a fourth circuit configuration example of the digital device according to the present embodiment. In Figure 59 , the data holding units (latches) of the ADCs 50 are connected in the vertical direction to configure a shift register. Then, in the configuration example, the multiple bits of the multiple ADCs 50 are serially output to the vertical signal line 27 using a shift clock.

[0252] Using Figure 59 the digital device in, since the row selection signal line 26 is not required and the vertical signal can be 1 bit (since there can be one vertical signal line 27), the circuit layout area can be reduced.

[0253] In Figure 58 and Figure 59 the examples of, the differential configuration shown in Figure 51 is used. However, the single-phase configuration shown in Figure 50 can be used. As shown in Figures 52 to 55 , the magnetoresistive element 10 can also be divided into multiple groups. Moreover, in Figure 58 and Figure 59In the example, an ADC 50 can be set for each group, and after selecting a group, a read signal can be input or the read signal can be input to the ADC 50.

[0254] Figure 60 is a fifth circuit configuration example of the digital device according to the present embodiment. In Figure 60 , the digital device is configured by a counting unit including a counter 52 for one magnetoresistive element 10. The comparator 53 outputs the comparison result between the output of the magnetoresistive element 10, that is, the resistance value of the magnetoresistive element 10 and a reference resistance value. Here, for example, the comparator 53 outputs an enable signal only when the state of the magnetoresistive element 10 is in the parallel state. The counter 52 receives a clock signal as an input in addition to the output of the comparator 53. Then, the counter 52 counts the clock signal only when the output of the comparator 53 is enabled. In addition, in Figure 60 In the shown circuit configuration example, it is preferable not to provide the filter device F1 connected to the magnetoresistive element 10.

[0255] Using Figure 60 In the digital device in, since the state difference of the magnetoresistive element 10 can be directly measured by the clock signal and the counter, the noise superimposed on the analog signal can be further reduced.

[0256] Figure 61 is a sixth circuit configuration example of the digital device according to the present embodiment. In Figure 61 , the digital device is configured by a counting unit including two counters 52 for two magnetoresistive elements 10. In addition, in Figure 61 and Figure 62 In the example, when the states of the two magnetoresistive elements 10 are different, since the resistance values of the two magnetoresistive elements 10 cancel each other out, the voltage Vmtj caused by the resistance values of the two magnetoresistive elements 10 is Vmiddle. In addition, in Figure 61 In the shown example, the counter 52 is a circuit that counts when the two magnetoresistive elements 10 are in the same state. Note that in Figure 61 , the resistance values of the resistors R11, R12, R21, and R22 are set to satisfy V th1 >Vmiddle>V th2 .

[0257] Then, in this example, the two counters 52 output COUTH and COUTL. As the operation example of the sixth circuit configuration example in Figure 62As shown, when both magnetoresistive elements 10 are in the antiparallel state, the counter value of COUTH increases. In addition, when both magnetoresistive elements 10 are in the parallel state, the count value of COUTL increases. Therefore, the above-mentioned residence time difference S can be calculated using (COUTH - COUTL) / (COUTH + COUTL).

[0258] In addition, the above calculation can be performed either by the circuit of the magnetic detection device 20 or by an external processor after being output to the outside of the magnetic detection device 20.

[0259] Figure 63 is the seventh circuit configuration example of the digitizing device according to the present embodiment. In Figure 63 the digitizing device includes Figure 60 or Figure 61 a plurality of counting units shown in. Then, in this example, COUT1, COUT2,..., and COUTk are sequentially selected by internal selection signals 1 to k, and the accumulation result of the accumulator (ACC) 54 is output to the vertical signal line 27 based on the row selection signal.

[0260] In addition, in the present embodiment, the circuit structure of the digitizing unit is not limited to Figures 56 - 63 the example shown.

[0261] As described above, in the present embodiment, the easy axis direction of at least one magnetoresistive element 10 constituting the pixel unit 25 is made different from the easy axis direction of the other magnetoresistive elements 10 constituting the pixel unit 25. Alternatively, in the present embodiment, the easy axis direction of the magnetoresistive elements 10 of at least one pixel unit 25 included in the basic array pattern 31 is different from the easy axis direction of the magnetoresistive elements 10 of the other pixel units 25 included in the basic array pattern 31. In this way, according to the present embodiment, it is possible to detect the magnitude of the input magnetic field B in two or more axial directions with high sensitivity at spatially consistent positions. In addition, in the present embodiment, the pixel unit 25 and the basic array pattern 31 are arranged in an arrangement constituting the pixel array 24, so that a magnetic detection device 20 with spatial / temporal resolution and a simpler structure can be realized.

[0262] In addition, in the present embodiment, a plurality of magnetic detection devices 20 are provided, whereby it is possible to measure the magnetic field over a wider spatial range. For example, magnetocardiogram can be measured by arranging a plurality of magnetic detection devices 20 on a person's chest. Alternatively, magnetoencephalogram can be measured by arranging a plurality of magnetic detection devices 20 on a person's head.

[0263] <<2. Second Embodiment>>

[0264] <2.1 First Configuration Example of the Decoding System>

[0265] Subsequently, a decoding system for decoding the thoughts of a human or animal (referred to as a user) using the magnetic detection device 20 according to the first embodiment of the present disclosure explained above will be described. In this specification, the term "thoughts" includes the imagination, intention, recognition, judgment, etc. of a human or animal.

[0266] Figure 64 is a configuration example of a decoding system according to the second embodiment of the present disclosure. As Figure 64 shown, the decoding system 300 according to this embodiment includes a magnetoencephalographic sensor 310 that can measure the magnetoencephalogram of a human or animal using the magnetic detection device 20 according to the first embodiment. The decoding system 300 includes: a stimulation information output unit 320 that outputs information about the stimulation given to a human or animal; a biological information sensor 330 that acquires biological information about a human or animal; and an environmental information sensor 340 that outputs information about the environment around a human or animal. In addition, the decoding system 300 includes an encoder 350 and an arithmetic unit 360. The encoder 350 calculates a feature vector based on the input data that has been input, and the arithmetic unit 360 estimates information about the thoughts of a human or animal based on the feature vector.

[0267] The magnetoencephalographic sensor 310 can use the magnetic detection device 20 according to the first embodiment to measure the magnetoencephalogram of a human or animal. The magnetoencephalographic sensor 310 is worn on the head of a human or animal, measures the magnetoencephalogram, and inputs the measurement result to the encoder 350 described below as input data.

[0268] The stimulation information output unit 320 inputs information about the stimulation given to a human or animal (such as visual, auditory, and tactile stimulations) as input data to the encoder 350 described below. For example, the stimulation information output unit 320 can be a display device or an acoustic device viewed by a human or animal. In this case, the stimulation information output unit 320 inputs the image data or acoustic data to be output to the encoder 350. Alternatively, for example, for stimulation information about touch, taste, smell, hearing, etc., a human inputs subjective information about the touch on the object being touched by the human, the taste being tasted by the human, and the smell being smelled by the human to the stimulation information output unit 320. The stimulation information output unit 320 inputs the input information to the encoder 350.

[0269] The bioinformation sensor 330 may be an electromyography sensor, a heart rate sensor, a pulse sensor, a blood flow sensor, a blood pressure sensor, a respiration sensor, an electroencephalogram sensor, a sweat sensor, a skin temperature sensor, a skin conductivity sensor, etc., which are worn on a part of a human or animal body. The bioinformation sensor 330 may be a motion sensor that detects the motion and posture of a human or animal body. Specifically, the motion sensor unit includes an acceleration sensor, a gyroscope sensor, and a geomagnetic sensor. In addition, the bioinformation sensor 330 may be an imaging device that captures the facial expressions, gaze, or eye movements of a human or animal. Then, the bioinformation sensor 330 inputs the sensing data of the various sensors explained above into the encoder 350 explained below as input data.

[0270] The environmental information sensor 340 may include a position information sensor, such as a GPS (Global Positioning System) receiver that obtains the position information of a human or animal. The environmental information sensor 340 may include various other sensors, such as a sound collection microphone, an atmospheric pressure sensor, a temperature sensor, and a humidity sensor, in order to obtain environmental information indicating the state of the environment around a human or animal. Then, the environmental information sensor 340 inputs the sensing data through the above various sensors into the encoder 350 explained below as input data.

[0271] Note that the input data from the magnetoencephalogram sensor 310, the stimulation information output unit 320, the bioinformation sensor 330, and the environmental information sensor 340 may be time series data, and the format, etc. of the input data are not particularly limited.

[0272] The encoder 350 obtains input data from the magnetoencephalogram sensor 310, the stimulation information output unit 320, the bioinformation sensor 330, and the environmental information sensor 340, calculates eigenvalue (such as eigenvector) from the input data, and inputs the calculation result into the operation unit 360 explained below. For example, the encoder 350 may calculate the eigenvalue from the input data with reference to a model obtained in advance through machine learning, or may calculate the eigenvalue by performing statistical processing (average value, variance, normalization, etc.) on the input data. The encoder 350 may include a preprocessing unit that preprocesses the input data.

[0273] The operation unit 360 converts (decodes) the feature vector into the thoughts of a human or an animal. For example, the operation unit 360 may convert the feature vector or the like into an indicator indicating the thoughts of a human or an animal or the like with reference to a model (mathematical expression, etc.) obtained in advance by machine learning. For example, by inputting the feature vector obtained from the input data and the subjectivity of a human or the behavior of a human or an animal linked to the input data as input signals and training signals into a supervised learning device such as support vector regression or a deep neural network and causing the supervised learning device to perform machine learning, a model obtained in advance by machine learning can be obtained. It should be noted that such machine learning can be performed by incorporating the learning device into the Figure 64 configuration in

[0274] Figure 65 is an example of the use of the first configuration of the decoding system according to the present embodiment. As Figure 65 shown, a plurality of magnetoencephalography sensors 310 are worn on a person's head. The magnetoencephalography sensors 310 include a plurality of magnetic detection devices 20 according to the first embodiment, and may further include a plurality of biological information sensors 330 and environmental information sensors 340 as auxiliary sensors. Then, in the present embodiment, input data including at least one of the output of the magnetoencephalography sensors 310, the output from the stimulus information output unit 320, the output of the biological information sensors 330, and the output of the environmental information sensors is input to the encoder 350. The output from the stimulus information output unit 320 is information about a stimulus such as a visual, auditory, or tactile stimulus given to a person. The output of the biological information sensors 330 is biological information such as a person's heartbeat, blood flow, sweating, line of sight, and facial expression. The output from the environmental information sensors 340 includes information such as the sound around a person. Then, the input data is converted into a feature vector by the encoder 350. Further, the feature vector is converted into a person's thoughts by the operation unit 360. Note that, in the present embodiment, the input data includes at least the output of the magnetoencephalography sensors 310.

[0275] Since the decoding system 300 explained above can be used to estimate the thoughts of a human or an animal based on the magnetoencephalogram of the human or the animal, for example, an automatic control device (such as a robot) can be constructed that estimates a desire that is one of the thoughts of a human or an animal and operates according to the estimated request. Even when a human has impairments in skills (speech, hand movement, etc.) for communicating requests to the outside, such an automatic control device can operate according to the requests of the human. Therefore, the automatic control device can support human life.

[0276] Since the above-described decoding system 300 can be used to estimate the thoughts of a human or an animal based on the magnetoencephalogram of the human or the animal, for example, an emotion, which is one of the thoughts of a human, can be estimated by giving such a stimulus (e.g., an image or music). Then, based on this estimation, for example, a suggestion such as music that causes happiness can be appropriately recommended according to an individual.

[0277] <2.2 Second Configuration Example of the Decoding System>

[0278] The decoding system may be a decoding system that generates stimulus information to be given to a human or an animal. Figure 66 Another configuration example of the decoding system according to the second embodiment of the present disclosure is shown. In the configuration example, a decoding system that estimates the thoughts of a human or an animal using the magnetic detection device 20 according to the first embodiment of the present disclosure explained above and determines a stimulus to be given to the human based on the estimated thoughts is explained.

[0279] The decoding system 300 in the second configuration example is basically the same as the first configuration example described with reference to Figure 64 However, instead of estimating the thoughts of a human or an animal, it determines a stimulus (stimulus information) to be given to the human or the animal. The determined stimulus may be, for example, music, video, image, smell, feeling, dish, product (daily necessities, clothes, etc.), or a schedule suggestion given to the human or the animal.

[0280] The arithmetic unit 360 converts the feature vector into information (decodes) about the stimulus to be given to the human or the animal. For example, the arithmetic unit 360 can convert the feature vector or the like into information about the stimulus to the human or the animal by referring to a model (mathematical expression, etc.) obtained in advance by machine learning. For example, by inputting input data obtained when a specific stimulus (music, video, image, smell, dish, or product) is given as a training signal to a supervised learning device such as support vector regression or a deep neural network and causing the supervised learning device to perform machine learning, a model obtained in advance by machine learning can be obtained. It should be noted that such machine learning can be performed by incorporating the learning device into the Figure 66 configuration in.

[0281] For example, although the feeling of being stimulated comfortably varies depending on the individual or the animal, by using this configuration example, an appropriate stimulus that makes the individual or the animal feel comfortable can be determined. Therefore, by using the above-described decoding system 300, for example, a suggestion such as comfortable music can be appropriately recommended according to an individual. Although the appropriate stimulus that causes a behavioral change varies depending on the individual human or animal, by using this configuration example, an appropriate stimulus for the individual human or animal can be determined and the behavioral change can be effectively promoted.

[0282] Note that in the present embodiment, the brain magnetoelectric sensor 310 may be mounted on a wearable device such as an HMD (Head Mounted Display) or headphones worn on a person's head.

[0283] <<3.Supplement>>

[0284] The preferred embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the technical scope of the present disclosure is not limited to such examples. Obviously, a technician with ordinary knowledge in the technical field of the present disclosure can obtain various changes or corrections within the scope of the technical ideas described in the claims. It should be understood that these changes and corrections naturally belong to the technical scope of the present disclosure.

[0285] The effects described in this specification are merely illustrative or illustrative, and are not restrictive. That is, the technology according to the present disclosure can achieve other effects that are obvious to those skilled in the art from the description of this specification together with or instead of the effects described above.

[0286] It should be noted that the present technology can also adopt the following configurations.

[0287] (1) A magnetic detection device comprising:

[0288] A pixel array unit composed of a pixel unit including a magnetoresistive element and a detection unit, the pixel array unit is arranged in an array or is composed of a basic array including a plurality of pixel units arranged in an array, wherein

[0289] The magnetoresistive elements include:

[0290] The fixed layer has a fixed magnetization direction;

[0291] a non-magnetic layer disposed on the fixed layer; and

[0292] a storage layer disposed on the nonmagnetic layer, and

[0293] The detection unit detects an external magnetic field based on a change in a resistance value of the magnetoresistive element.

[0294] (2) The magnetic detection device according to (1), wherein:

[0295] The storage layer includes an easy axis in which the easy magnetization direction is more easily directed than other directions and a difficult axis in which the magnetization direction of the storage layer is less easily directed than other directions, and

[0296] Detection unit

[0297] outputting a detection result of an external magnetic field based on a change in the resistance value of the magnetoresistive element in a predetermined direction determined by the magnetization direction of a fixed layer of the magnetoresistive element of the pixel unit in linkage with coordinate information of a pixel array unit of the pixel unit corresponding to the detected magnetoresistive element, and

[0298] In a pixel unit or a basic array, the easy axis direction of at least one magnetoresistive element is different from that of other magnetoresistive elements.

[0299] (3) The magnetic detection device according to (1) or (2), wherein

[0300] the magnetoresistive element

[0301] outputs at least one of information on a first retention time for maintaining a state in which the magnetization direction of the storage layer is parallel to the magnetization direction of the fixed layer and information on a second retention time for maintaining a state in which the magnetization direction of the storage layer is antiparallel to the magnetization direction of the fixed layer to a detection unit, and

[0302] the detection unit

[0303] detects an external magnetic field based on a difference between the first retention time and the second retention time, the first retention time and the second retention time being specified based on at least one of the information on the first retention time and the information on the second retention time.

[0304] (4) The magnetic detection device according to any one of (1) to (3) further includes:

[0305] a control unit that controls the magnetic detection device;

[0306] a vertical scanning unit that vertically scans a pixel array unit according to the control of the control unit; and

[0307] a horizontal scanning unit that horizontally scans the pixel array unit according to the control of the control unit.

[0308] (5) The magnetic detection device according to (3), wherein

[0309] the pixel unit includes a plurality of magnetoresistive elements, and

[0310] the detection unit

[0311] detects an external magnetic field based on a difference between a cumulative value of the first retention time and a cumulative value of the second retention time in each magnetoresistive element.

[0312] (6) The magnetic detection device according to any one of (1) to (4), wherein

[0313] the pixel unit

[0314] includes an array of magnetoresistive elements, which includes a plurality of magnetoresistive elements connected in parallel and / or in series, and

[0315] the detection unit

[0316] detects an external magnetic field based on a resistance value of the array of magnetoresistive elements.

[0317] (7) The magnetic detection device according to any one of (1) to (4), wherein

[0318] The pixel unit includes a plurality of magnetoresistive elements, and

[0319] The detection unit divides the plurality of magnetoresistive elements included in the corresponding pixel unit into a plurality of groups, and detects an external magnetic field for each group.

[0320] (8) The magnetic detection device according to (4), wherein

[0321] The horizontal scanning unit converts the external magnetic field detected for each pixel unit into a digital value.

[0322] (9) The magnetic detection device according to any one of (1) to (7), wherein

[0323] The pixel unit further includes a conversion unit that converts the detected external magnetic field into a digital value.

[0324] (10) The magnetic detection device according to (2), wherein

[0325] In at least one magnetoresistive element, the length in the easy axis direction is longer than the length in the hard axis direction.

[0326] (11) The magnetic detection device according to (10), wherein

[0327] The planar shape of at least one magnetoresistive element is elliptical.

[0328] (12) The magnetic detection device according to any one of (1) to (11), wherein

[0329] The planar shape of at least one magnetoresistive element is circular.

[0330] (13) The magnetic detection device according to (2), wherein

[0331] The pixel unit includes:

[0332] A first magnetoresistive element whose easy axis direction is a first direction; and

[0333] A second magnetoresistive element, wherein the easy axis direction is a second direction that is 90° different from the first direction.

[0334] (14) The magnetic detection device according to (13), wherein

[0335] The pixel unit

[0336] Further includes a third magnetoresistive element, in which the easy axis direction is a third direction that is 90° different from each of the first direction and the second direction.

[0337] (15) The magnetic detection device according to (2), wherein,

[0338] The basic array includes:

[0339] A first pixel unit, including a first magnetoresistive element whose easy axis direction is a first direction; and

[0340] A second pixel unit, including a second magnetoresistive element, in which the direction of the easy axis is a second direction that is 90° different from the first direction.

[0341] (16) The magnetic detection device according to (15), wherein

[0342] The basic array

[0343] Further includes a third pixel unit, which includes a third magnetoresistive element, in which the direction of the easy axis is a third direction that is 90° different from each of the first direction and the second direction.

[0344] (17) The magnetic detection device according to (16), wherein,

[0345] The basic array further includes:

[0346] A fourth pixel unit, which includes a first magnetoresistive element and a third magnetoresistive element; and

[0347] A fifth pixel unit, including a second magnetoresistive element and a third magnetoresistive element.

[0348] (18) The magnetic detection device according to (16) or (17), wherein,

[0349] The basic array

[0350] Further includes a sixth pixel unit, which includes a first magnetoresistive element and a second magnetoresistive element.

[0351] (19) The magnetic detection device according to (18), wherein

[0352] The sixth pixel unit

[0353] Further includes a third magnetoresistive element.

[0354] (20) A decoding system, including: a magnetic detection device worn on a user; an encoder; an arithmetic unit, wherein,

[0355] The magnetic detection device

[0356] Includes a pixel array unit and a detection unit, the pixel array unit is composed of pixel units including magnetoresistive elements, the detection unit is arranged in an array or is composed of a basic array including multiple pixel units, and the basic array is arranged in an array,

[0357] The magnetoresistive element includes:

[0358] A fixed layer having a fixed magnetization direction;

[0359] A non-magnetic layer provided on the fixed layer; and

[0360] A storage layer disposed on the non-magnetic layer,

[0361] A detection unit detects an external magnetic field based on a change in the resistance value of the magnetoresistive element,

[0362] An encoder

[0363] Obtains the external magnetic field from the magnetic detection device as input data, and

[0364] Calculates a feature vector based on the input data, and

[0365] An arithmetic unit outputs the user's thoughts or gives a stimulus to the user based on the feature vector.

[0366] (21) The decoding system according to (20), wherein,

[0367] The magnetic detection device

[0368] Further includes a motion sensor for detecting the motion and posture of the user, and

[0369] Outputs the output of the motion sensor together with the external magnetic field to the encoder as input data, and

[0370] The encoder

[0371] Calculates a feature vector based on the output of the motion sensor.

[0372] (22) The decoding system according to (20) or (21), wherein,

[0373] The magnetic detection device

[0374] Further includes a biological information sensor for acquiring the biological information of the user, and

[0375] Outputs the output of the biological information sensor together with the external magnetic field as input data to the encoder, and

[0376] The encoder

[0377] Calculates a feature vector based on the output of the biological information sensor.

[0378] (23) The decoding system according to any one of (20) to (22), wherein,

[0379] The input data contains information about at least one of the auditory stimuli, visual stimuli, olfactory stimuli, taste stimuli, and tactile stimuli given to the user.

[0380] List of reference numerals

[0381] 10, 210C, 210E, 210L, 210NE, 210NW, 210V magnetoresistive element

[0382] 11, 211, 216 magnetization fixing layer

[0383] 12, 212, 217 non-magnetic layer

[0384] 13, 213, 218 storage layer

[0385] 20 magnetic detection device

[0386] 21 control unit

[0387] 22 vertical scanning unit

[0388] 23 horizontal scanning unit

[0389] 24 pixel array

[0390] 25, 25A, 25B, 25C, 25D pixel unit

[0391] 26 row selection signal line

[0392] 27 vertical signal line

[0393] 28 data output line

[0394] 29 information processing device

[0395] 30 input signal

[0396] 31 basic array pattern

[0397] 40 base substrate

[0398] 42, 243, 245 wire

[0399] 50 analog / digital converter

[0400] 51 interface

[0401] 52 counter

[0402] 53 comparator

[0403] 54 storage battery

[0404] 214, 219 upper electrode

[0405] 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231 array

[0406] 241, 242, 244 insulating layer

[0407] 250C, 250E laminated film

[0408] 251, 256 first layer

[0409] 252, 257 second layer

[0410] 253, 258 third layer

[0411] 255C, 255E structure

[0412] 300 decoding system

[0413] 310 magnetoencephalogram sensor

[0414] 320 stimulation information output unit

[0415] 330 biological information sensor

[0416] 340 environmental information sensor

[0417] 350 encoder

[0418] 360 operation unit

[0419] A21, A23 grooves

[0420] A22, A24 openings

[0421] B1 buffer

[0422] D1 differential amplifier circuit

[0423] F1 filter device

[0424] M21, M23 masks

[0425] R1, R2, R4, R11, R12, R21, R22 resistors

[0426] SH1 sample and hold unit

[0427] SW1 row selection switch

[0428] SW2 magnetoresistive selection switch

[0429] SW3 sample and hold pre-read reset switch.

Claims

1. A magnetic detection device, comprising: a pixel array unit configured by pixel units arranged in an array, the pixel units including magnetoresistive elements and detection units, or the pixel array unit being composed of a basic array including a plurality of the pixel units arranged in an array, wherein, the magnetoresistive element includes: a fixed layer having a fixed magnetization direction; a non-magnetic layer provided on the fixed layer; and a storage layer provided on the non-magnetic layer, and the detection unit detects an external magnetic field based on a change in the resistance value of the magnetoresistive element.

2. The magnetic detection device according to claim 1, wherein, the storage layer includes an easy axis in which the magnetization direction is more likely to point in one direction than in other directions and a hard axis in which the magnetization direction of the storage layer is less likely to point in one direction than in other directions, and the detection unit outputs a detection result of the external magnetic field in association with coordinate information of the pixel array unit of the pixel unit corresponding to the detected magnetoresistive element, the detection result being based on a change in the resistance value of the magnetoresistive element in a predetermined direction determined by the magnetization direction of the fixed layer of the magnetoresistive element of the pixel unit, and in the pixel unit or the basic array, the direction of the easy axis of at least one magnetoresistive element is different from the direction of the easy axis of other magnetoresistive elements.

3. The magnetic detection device according to claim 1, wherein, the magnetoresistive element outputs at least one of information on a first retention time for maintaining a state in which the magnetization direction of the storage layer is parallel to the magnetization direction of the fixed layer and information on a second retention time for maintaining a state in which the magnetization direction of the storage layer is antiparallel to the magnetization direction of the fixed layer to the detection unit, and the detection unit detects the external magnetic field based on a difference between the first retention time and the second retention time, the difference between the first retention time and the second retention time being specified based on at least one of the information on the first retention time and the information on the second retention time.

4. The magnetic detection device according to claim 1, wherein, it further includes: a control unit for controlling the magnetic detection device; a vertical scanning unit for vertically scanning the pixel array unit according to the control of the control unit; and a horizontal scanning unit for horizontally scanning the pixel array unit according to the control of the control unit.

5. The magnetic detection device according to claim 3, wherein, the pixel unit includes a plurality of the magnetoresistive elements, and the detection unit detects the external magnetic field based on a difference between a cumulative value of the first retention time of each magnetoresistive element and a cumulative value of the second retention time.

6. The magnetic detection device according to claim 1, wherein, the pixel unit includes an array of magnetoresistive elements, the array including a plurality of the magnetoresistive elements connected in parallel and / or in series, and the detection unit detects the external magnetic field based on the resistance value of the array of magnetoresistive elements.

7. The magnetic detection device according to claim 1, wherein, the pixel unit includes a plurality of the magnetoresistive elements, and The detection unit divides a plurality of the magnetoresistive elements included in the corresponding pixel unit into a plurality of groups, and detects the external magnetic field for each group.

8. The magnetic detection device according to claim 4, wherein, the horizontal scanning unit converts the external magnetic field detected for each pixel unit into a digital value.

9. The magnetic detection device according to claim 1, wherein, the pixel unit further includes a conversion unit that converts the detected external magnetic field into a digital value.

10. The magnetic detection device according to claim 2, wherein, in the at least one magnetoresistive element, the length in the direction of the easy axis is longer than the length in the direction of the hard axis.

11. The magnetic detection device according to claim 10, wherein, the planar shape of the at least one magnetoresistive element is an ellipse.

12. The magnetic detection device according to claim 1, wherein, the planar shape of at least one magnetoresistive element is a circle.

13. The magnetic detection device according to claim 2, wherein, the pixel unit includes: a first magnetoresistive element in which the direction of the easy axis is a first direction; and a second magnetoresistive element in which the direction of the easy axis is a second direction that is 90° different from the first direction.

14. The magnetic detection device according to claim 13, wherein, the pixel unit further includes a third magnetoresistive element in which the direction of the easy axis is a third direction that is 90° different from each of the first direction and the second direction.

15. The magnetic detection device according to claim 2, wherein, the basic array includes: a first pixel unit including a first magnetoresistive element in which the direction of the easy axis is a first direction; and a second pixel unit including a second magnetoresistive element in which the direction of the easy axis is a second direction that is 90° different from the first direction.

16. The magnetic detection device according to claim 15, wherein, the basic array further includes a third pixel unit including a third magnetoresistive element in which the direction of the easy axis is a third direction that is 90° different from each of the first direction and the second direction.

17. The magnetic detection device according to claim 16, wherein, the basic array further includes: a fourth pixel unit including the first magnetoresistive element and the third magnetoresistive element; and a fifth pixel unit including the second magnetoresistive element and the third magnetoresistive element.

18. The magnetic detection device according to claim 16, wherein, the basic array further includes a sixth pixel unit including the first magnetoresistive element and the second magnetoresistive element.

19. The magnetic detection device according to claim 18, wherein, the sixth pixel unit further includes the third magnetoresistive element.

20. A decoding system, comprising: a magnetic detection device worn on a user; an encoder; an arithmetic unit, wherein, the magnetic detection device A pixel array unit configured by pixel units arranged in an array, the pixel units including magnetoresistive elements and detection units, or the pixel array unit configured by a basic array including a plurality of pixel units arranged in an array, The magnetoresistive element includes: A fixed layer having a fixed magnetization direction; A non-magnetic layer provided on the fixed layer; and A storage layer provided on the non-magnetic layer, The detection unit detects an external magnetic field based on a change in the resistance value of the magnetoresistive element, The encoder Obtains the external magnetic field as input data from the magnetic detection device, and calculates a feature vector based on the input data, and The arithmetic unit outputs the user's thoughts or gives a stimulus to the user based on the feature vector.

21. The decoding system according to claim 20, wherein, The magnetic detection device Further includes a motion sensor for detecting the motion and posture of the user, and Outputs the output of the motion sensor together with the external magnetic field to the encoder as the input data, and The encoder Calculates the feature vector based on the output of the motion sensor.

22. The decoding system according to claim 20, wherein, The magnetic detection device Further includes a biometric information sensor for acquiring the biometric information of the user, and outputs the output of the biometric information sensor together with the external magnetic field to the encoder as the input data, and The encoder Calculates the feature vector based on the output of the biometric information sensor.

23. The decoding system according to claim 20, wherein, The input data includes information about at least one of an auditory stimulus, a visual stimulus, an olfactory stimulus, a taste stimulus, and a tactile stimulus given to the user.

Images