Magnetic property measuring apparatus

Abstract

To provide a magnetic property measuring apparatus capable of shortening measurement time.SOLUTION: A magnetic property measuring apparatus 1 comprises a first magnetic field generating unit that generates a gradient magnetic field that varies depending on the location, a second magnetic field generating unit that generates a time-variable high-frequency magnetic field, a first actuator that moves the second magnetic field generating unit, a mounting table on which a test object is placed, a second actuator that moves the mounting table, and a measuring unit that measures the magnetic property of the test object moving in the gradient magnetic field.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a magnetic property measuring device, for example, a magnetic property measuring device that inspects the magnetic properties of a magnetoresistive memory element at high speed and with high sensitivity.

Background Art

[0002] A semiconductor memory element called a magnetoresistive random access memory (MRAM) is a non-volatile memory having a magnetic tunnel junction (MTJ) as a component. In a semiconductor production line, it is important to improve the yield of magnetoresistive memory device production by early inspection of abnormalities in the magnetoresistive memory formed on a wafer before the completion of the magnetoresistive memory device (MRAM Device). For inspection before the completion of the magnetoresistive memory device, it is necessary to grasp not only the non-destructive appearance inspection by an optical microscope or an electron beam but also the magnetic properties.

[0003] As a means for high-speed measurement of magnetic properties, optical measurement using a magneto-optical effect called the magneto-optical Kerr effect (MOKE) is known. According to this method, an external magnetic field is applied to each magnetoresistive memory in a magnetoresistive memory device, and while changing the magnetic field strength, a magnetic hysteresis loop at the measurement point can be obtained from the amount of change in polarization in the reflected light. However, such optical measurement requires a measurement time of 10 to 30 seconds because an external magnetic field is applied to each measurement point to obtain a magnetic hysteresis loop.

[0004] Also, as described in Non-Patent Document 1, an analysis method called FMR (Ferromagnetic Resonance) is also known as a means for measuring magnetic properties. In this method, a magnetic field is generated from microwaves generated by an AC current in a static magnetic field of about 0 to 1 T. Then, this method obtains the frequency that causes ferromagnetic resonance of the precessing magnetization vector for each value of the static magnetic field. Thereby, this method can measure the anisotropic magnetic field Hk and the damping coefficient α, which are one of the important properties of the magnetic resistance memory.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Non-Patent Documents

[0006]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, since FMR uses a microwave magnetic field and a waveguide for the measurement target, it is necessary to sweep the static magnetic field and the frequency of the AC current for each measurement point. For this reason, there is a problem that the measurement time takes more than several minutes.

[0008] The present disclosure has been made to solve such problems, and an object thereof is to provide a magnetic property measuring apparatus capable of shortening the measurement time.

Means for Solving the Problems

[0009] A magnetic property measuring apparatus according to an embodiment includes a first magnetic field generating unit that generates an inclined magnetic field whose magnetic field varies depending on the location, a second magnetic field generating unit that generates a time-variable high-frequency magnetic field, a first actuator that moves the second magnetic field generating unit, a mounting table on which a test object is placed, a second actuator that moves the mounting table, and a measuring unit that measures the magnetic properties of the test object moving in the inclined magnetic field.

[0010] The magnetic property measuring apparatus further includes a light source that generates light, a polarizer that converts the generated light into linearly polarized light, an objective lens that forms an image of the light on the test object, an unpolarized beam splitter that separates the light, an analyzer that detects a rotation component in the linearly polarized light of the light, and a line sensor that acquires a scan image obtained by scanning the light on the test object, and may measure the magnetic properties and the polarization state of the light.

[0011] In the magnetic property measuring apparatus, before measuring the test object in the high-frequency magnetic field, a preliminary measurement for measuring the relationship between the frequency and the magnetic field characteristics in a predetermined position in advance, and a main measurement for measuring the magnetic properties with the frequency and the magnetic field to be measured may be performed.

[0012] In the magnetic property measuring device, a control unit for controlling the first magnetic field generating unit, the second magnetic field generating unit, the first actuator, and the second actuator is further provided. The control unit moves the second magnetic field generating unit by the first actuator, and while moving the mounting table by the second actuator, a first measurement mode of measuring the magnetic properties of the test object by the measurement unit, and a second measurement mode of measuring the magnetic properties of the test object by the measurement unit while moving the mounting table by the second actuator with the position of the second magnetic field generating unit fixed may be executed.

[0013] In the magnetic property measuring device, the control unit may further execute a mode of specifying the resonance frequency of the test object based on the magnetic properties of the test object measured in the first measurement mode, and in the second measurement mode, measure the magnetic properties of the test object at frequencies in a range including the resonance frequency.

[0014] In the magnetic property measuring device, the second magnetic field generating unit may include a slit in which an optical path between the objective lens and the test object is arranged.

[0015] In the magnetic property measuring device, the first magnetic field generating unit includes two or more magnet units, and the optical path between the objective lens and the test object may be arranged between the two or more magnet units.

[0016] In the magnetic property measuring device, the inclined magnetic field may be a static magnetic field.

[0017] In the magnetic property measuring device, the measurement of the magnetic properties may be performed under the atmosphere.

[0018] In the magnetic property measuring device, a temperature control unit for controlling the temperature of the test object may be further provided.

[0019] In the magnetic property measuring device, a third actuator for moving the first magnetic field generating unit may be further provided.

[0020] In the magnetic property measurement device, in the first measurement mode, the control unit may move the second magnetic field generation unit together with the test object with respect to the first magnetic field generation unit, and in the second measurement mode, move the test object with respect to the second magnetic field generation unit and the first magnetic field generation unit.

Effect of the Invention

[0021] According to the present disclosure, it is possible to provide a magnetic property measurement device capable of shortening the measurement time.

Brief Description of the Drawings

[0022]

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Mode for Carrying Out the Invention

[0023] (Embodiment 1) The magnetic property measurement apparatus according to Embodiment 1 will be described. FIG. 1 is a configuration diagram illustrating the magnetic property measurement apparatus 1 according to Embodiment 1. FIG. 2 is a configuration diagram illustrating the main part of the magnetic property measurement apparatus 1 according to Embodiment 1. FIG. 3 is a plan view illustrating the magnetic field generation unit 20 in the magnetic property measurement apparatus 1 according to Embodiment 1. FIG. 4 is a cross-sectional view illustrating the magnetic field generation unit 20 in the magnetic property measurement apparatus 1 according to Embodiment 1, showing the cross section taken along line IV-IV of FIG. 3.

[0024] As shown in FIGS. 1 to 4, the magnetic property measuring apparatus 1 includes apparatuses W1 to W3 related to the conveyance of the wafer WF to be measured, members B1 to B4 related to the base of the magnetic property measuring apparatus 1, a magnetic field generating unit 10, a magnetic field generating unit 20, an actuator A10, an actuator A20, a stage STG, a measuring unit MS, an optical system 30, a detector 40, an information processing unit 50, and a power supply and control unit 60. In addition to having a function of holding the wafer WF by a wafer chuck on the stage STG, a heater for controlling the temperature of the wafer WF may be disposed. The temperature control means is not limited to a heater, and a method of irradiating the surface of the wafer WF to be measured with a laser may also be used. The test specimen is, for example, a magnetoresistive memory element (MRAM element) formed on the wafer WF. For the sake of simplicity of explanation, the wafer WF may be referred to as a test specimen. The test specimen is not limited to the MRAM element formed on the wafer WF, and may be an MRAM element singulated into chips or the like.

[0025] The apparatuses W1 to W3 related to the conveyance of the wafer WF include a wafer transfer robot W1, a pre-wafer alignment apparatus W2, and a wafer supply cassette W3. The wafer transfer robot W1 transfers the wafer WF to be measured from the wafer supply cassette W3 into the magnetic property measuring apparatus 1. The pre-wafer alignment apparatus W2 corrects the rotation angle and shift of the wafer WF. The wafer WF is transferred to the stage STG of the magnetic property measuring apparatus 1 after being adjusted by the pre-wafer alignment apparatus W2.

[0026] The members B1 to B4 related to the base of the magnetic property measuring apparatus 1 include a granite base (Base) B1, an active vibration isolator (Isolator) B2, a wedge B3, and a dispersion plate B4. The granite base B1 serves as a base on which members such as the stage STG and the optical system 30 are disposed. The active vibration isolator B2 suppresses the vibration of the members on the granite base B1. The wedge B3 performs horizontal adjustment of the granite base B1 and the active vibration isolator B2. The dispersion plate B4 disperses the apparatus load on the floor.

[0027] The information processing unit 50 processes the information detected by the detector 40. The information processing unit 50 has a function of receiving images acquired by a TDI camera, a CCD camera, etc., and signals obtained by a measurement unit MS such as the microwave generator 23, and processing these images and signals.

[0028] The power supply and control unit 60 supplies power to the magnetic property measurement device 1 and controls each part of the magnetic property measurement device 1. For example, the control unit 60 controls the magnetic field generation unit 10, the magnetic field generation unit 20, the actuator A10, and the actuator A20. The magnetic property measurement device 1 may perform measurement of the magnetic properties of the wafer WF under the atmosphere. Further, the magnetic property measurement device 1 may further include a temperature control unit that controls the temperature of the wafer WF.

[0029] The stage STG mounts the wafer WF which is the test object. The stage STG may be called a mounting table. The stage STG has a stage surface ST1. The magnetic property measurement device 1 measures the magnetic properties of the MRAM element in the wafer WF mounted on the stage surface ST1 of the stage STG. The stage STG may have a wafer chuck for holding the wafer WF. The wafer WF is fixed on the stage surface ST1 by vacuum or static electricity by the wafer chuck.

[0030] An actuator A20 is attached to the stage STG. The actuator A20 moves the stage STG. The actuator A20 has, for example, XYZθ drive axes by a linear motor, a ball screw, a VCM, a piezo, etc. A measurement plane Z0 is introduced as a plane parallel to the stage surface ST1. For example, the measurement plane Z0 may include the upper surface of the wafer WF. Then, the wafer WF (MRAM element) fixed to the stage surface ST1 moves within a plane parallel to the measurement plane Z0. The positions of the wafer WF and the MRAM element may be measured by a laser interferometer 14. Thus, the actuator A20 moves the MRAM element fixed to the stage STG within a plane parallel to the stage surface ST1. For example, the actuator A20 linearly moves the MRAM element along one direction within a plane parallel to the measurement plane Z0.

[0031] Here, for the convenience of explaining the magnetic property measuring apparatus 1, an XYZ orthogonal coordinate axis system is introduced. The direction orthogonal to the measurement plane Z0 is defined as the Z-axis direction, and two orthogonal directions within the plane parallel to the measurement plane Z0 are defined as the X-axis direction and the Y-axis direction. The +Z-axis direction is called upward, and the -Z-axis direction is called downward. Note that upward and downward are for the convenience of explanation and do not indicate the direction in which the actual magnetic property measuring apparatus 1 is arranged.

[0032] As shown in FIG. 1, in this embodiment, the configuration of the XYZθ stage is shown, but a configuration using an rθ stage may also be used.

[0033] The magnetic field generating unit 10 generates an inclined magnetic field that varies depending on the location. The conventional inclined magnetic field was such that the coil magnetic field itself varied by changing the current value of the coil. The "inclined magnetic field that varies depending on the location" in this embodiment means, for example, an inclined magnetic field in which the static magnetic field strength varies depending on the location. More specifically, it means that a plurality of magnetic field generation sources having different magnetic field directions are arranged at different positions, and the magnetic field applied to the test object is varied by moving the test object within the magnetic field. The magnetic field generating unit 10 may be referred to as the first magnetic field generating unit 10 in some cases.

[0034] The magnetic field generation unit 10 is disposed above the stage STG. The magnetic field generation unit 10 includes a plurality of magnet units. The plurality of magnet units may include the electromagnets 11 and 12. Note that the plurality of magnet units are not limited to the electromagnets 11 and 12, and may include simple magnets. The plurality of electromagnets 11 and 12 are spaced apart in the X-axis direction. The plurality of electromagnets 11 and 12 may include two electromagnets 11 and 12 whose applied currents are independently controlled, or may include two electromagnets 11 and 12 whose applied currents are non-independently controlled. An optical path of incident light that has passed through the objective lens 34 for MOKE measurement and reflected light that has been reflected by the wafer WF may be disposed between the plurality of electromagnets 11 and 12. Thus, the optical path between the objective lens 34 and the wafer WF may be disposed between two or more magnet units. The magnetic field generation unit 10 may be disposed inside the frame 13. The magnetic property measurement apparatus 1 may further include an actuator A30 that moves the magnetic field generation unit 10.

[0035] FIG. 5 is a graph illustrating the magnetic field component in the Z-axis direction of magnetic field lines on the measurement plane Z0 in the magnetic property measurement apparatus 1 according to Embodiment 1. The horizontal axis represents the position in the X-axis direction on the measurement plane Z0, and the vertical axis represents the magnetic field component in the Z-axis direction of magnetic field lines on the measurement plane Z0. FIG. 5 shows the results (Calculated) and the measured results (Measured) of the magnetic field component in the Z-axis direction of magnetic field lines calculated under various conditions.

[0036] As shown in FIGS. 2 and 5, a plurality of electromagnets 11 and 12 generate an inclined magnetic field on the measurement surface Z0. The plurality of electromagnets 11 and 12 generate an inclined magnetic field in which the direction of the magnetic field component in the Z-axis direction orthogonal to the measurement surface Z0 changes from the -Z-axis direction to the +Z-axis direction depending on the position of the measurement surface Z0. Here, the -Z-axis direction is the opposite direction of the +Z-axis direction. Specifically, for example, the inclined magnetic field has a portion where the direction of the magnetic field changes from the -Z-axis direction to the +Z-axis direction as the position moves from the -X-axis direction side to the +X-axis direction side. The magnitude of the magnetic field decreases from the end on the -X-axis direction side toward the central portion and becomes 0 at the central portion. Also, the magnitude of the magnetic field increases from the central portion toward the end on the +X-axis direction side. In this way, the plurality of electromagnets 11 and 12 generate a magnetic field that is constant in time and varies depending on the location. Therefore, the inclined magnetic field may be a static magnetic field.

[0037] The magnetic field generation unit 20 generates a high-frequency magnetic field that is variable in time. For example, the magnetic field generation unit 20 generates a microwave magnetic field whose frequency changes with time. Specifically, the magnetic field generation unit 20 generates an alternating magnetic field (AC magnetic field) of 0 to 50 GHz. For example, the magnetic field generation unit 20 generates a microwave magnetic field used for FMR measurement. The magnetic field generation unit 20 may be referred to as the second magnetic field generation unit 20. The magnetic field generation unit 20 is disposed between the stage STG and the electromagnets 11 and 12. Specifically, the magnetic field generation unit 20 is disposed between the wafer WF placed on the stage STG and the electromagnets 11 and 12. The magnetic field generation unit 20 may be fixed below the frame 13. The magnetic field generation unit 20 may generate, for example, an AC magnetic field along the Y-axis direction.

[0038] As shown in FIGS. 3 and 4, the magnetic field generation unit 20 includes, for example, a plurality of electrical signal probes 21a and 21b, a base material 22, a microwave generator 23, and a height sensor 24. The electrical signal probes 21a, etc. may be simply referred to as probes. The plurality of electrical signal probes 21a and 21b are collectively referred to as the electrical signal probe 21. Note that the number of the electrical signal probes 21 is not limited to two, and may be one or three or more. As will be described later, the plurality of electrical signal probes 21 may be arranged in a staggered pattern.

[0039] The base material 22 supports the electrical signal probe 21. The base material 22 includes, for example, a dielectric such as glass and has a rectangular plate shape. The plate surface of the base material 22 faces upward and downward. A slit 25 penetrating from the upper plate surface to the lower plate surface is formed in the base material 22. The slit 25 is, for example, formed in a rectangular shape on the plate surface. The slit 25 may be used as an optical path for incident light transmitted through the objective lens 34 for MOKE measurement and reflected light reflected by the wafer WF. Thus, the magnetic field generation unit 20 includes the base material 22 having a structure with a hollow center. The magnetic field generation unit 20 includes a slit 25 arranged so that the optical path between the objective lens 34 and the wafer WF is conductive. Further, the slit 25 may have a function of avoiding interference between the laser light for the optical autofocus sensor and the electrical signal probe 21.

[0040] The electrical signal probes 21 are arranged on the +X-axis direction side and the -X-axis direction side of the slit 25 on the lower plate surface of the base material 22. For example, the electrical signal probe 21a is arranged on the -X-axis direction side of the slit 25 on the lower plate surface of the base material 22, and the electrical signal probe 21b is arranged on the +X-axis direction side of the slit 25 on the lower plate surface of the base material 22.

[0041] The microwave generator 23 generates, for example, an alternating magnetic field of 0 to 50 GHz and may be a vector network analyzer. The terminals connected to the microwave generator 23 are connected to the terminals on the +Y-axis direction side and the -Y-axis direction side of the electrical signal probe 21a by signal lines. Therefore, the electrical signal probe 21a is arranged so as to face in the Y-axis direction. Similarly, the electrical signal probe 21b is arranged so as to face in the Y-axis direction. Thus, the electrical signal probes 21 are arranged so as to face in the Y-axis direction orthogonal to the X-axis direction which is the scan direction of the wafer WF. When a high-frequency electric field is generated in the signal line, a magnetic field is generated. In FIG. 3, an example of generating an AC magnetic field by a cobra-type line is shown, but a coaxial line, a strip line, and a microstrip line may also be used.

[0042] The height sensor 24 senses the height from the measurement surface Z0 of the magnetic field generation unit 20. The height sensor 24 may be, for example, a capacitance type.

[0043] FIG. 6 is a configuration diagram illustrating the magnetic field generation unit 20a in a magnetic property measurement apparatus according to another example of Embodiment 1. As shown in FIG. 6, three or more electrical signal probes 21a to 21f arranged to face in the Y-axis direction may be arranged side by side in the X-axis direction or in a staggered pattern.

[0044] The actuator A10 moves the magnetic field generation unit 20. The actuator A10 is attached to, for example, the base material 22. The actuator A10 moves the magnetic field generation unit 20 in the X-axis direction, for example. The actuator A10 may be referred to as a first actuator. In contrast, the actuator A20 of the stage STG described above may be referred to as a second actuator.

[0045] The measurement unit MS measures the magnetic properties of the MRAM disposed on the wafer WF that moves in the inclined magnetic field. The measurement unit MS is disposed in the vicinity of the wafer WF. The measurement unit MS may be a vector network analyzer of the microwave generator 23.

[0046] As shown in FIG. 1, the magnetic property measurement apparatus 1 may include an optical system 30. Note that the magnetic property measurement apparatus 1 may not include the optical system 30. The magnetic property measurement apparatus 1 includes the optical system 30 when measuring magnetic properties using MOKE. Thereby, the magnetic property measurement apparatus 1 measures magnetic properties and also measures the polarization state of the reflected light reflected by the wafer WF. On the other hand, the magnetic property measurement apparatus 1 may not include the optical system 30 when measuring magnetic properties using FMR.

[0047] The optical system 30 may include an optical microscope. The optical microscope observes the surface of the wafer WF. The optical system 30 has a light source 31, a filter 32, a polarizer 33, an objective lens 34, an analyzer 35, a filter 36, an AF sensor 37 for obtaining the focus of the wafer WF, as well as several lenses P1 - P9 and several mirrors (Мirrоr) M1 - M4.

[0048] The light source 31 generates illumination light. The illumination light is, for example, laser light. The illumination light generated from the light source 31 passes through the filter 32. Thereby, the illumination light comes to include a predetermined wavelength band. The illumination light that has passed through the filter 32 is incident on the polarizer 33. The polarizer 33 converts the generated illumination light into linearly polarized light. The illumination light including linearly polarized light is reflected by the mirror M2 and condensed onto the wafer WF by the objective lens 34. Note that the mirror M2 is, for example, an unpolarized beam splitter that separates illumination light.

[0049] The objective lens 34 is for imaging the pattern on the wafer WF, and generally a non - magnetic one is selected. The objective lens 34 images the illumination light on the wafer WF. When the wafer WF includes a magnetoresistive memory element, the polarization angle of the linearly polarized light changes due to the magneto - optical Kerr effect. The reflected light reflected by the wafer WF passes through the objective lens 34 and is incident on the analyzer (Analyzer) 35. The analyzer 35 detects the change in the polarization angle of the linearly polarized light included in the reflected light. That is, the analyzer 35 detects the rotation component in the linearly polarized light of the reflected light. The analyzer 35 includes, for example, a photodetector. The reflected light that has passed through the analyzer 35 is incident on the detector 40 via the filter 36. The AF sensor 37 is a member for focusing on the surface of the wafer WF. The AF sensor 37 uses a semiconductor laser light source that is longer or shorter than the wavelengths of the illumination light and the reflected light used in the optical system 30.

[0050] Detector 40 acquires the pattern of the wafer WF. Detector 40 may have a plurality of line sensors L1 and L2, as well as a review monitor 42. The plurality of line sensors L1 and L2 are collectively referred to as line sensor 41. The number of line sensors 41 is not limited to two, and may be three or more. The plurality of line sensors 41 may include, for example, a TDI (Time Delay Integration) sensor. The line sensor 41 acquires a scanned image obtained by scanning illumination light on the wafer WF. The review monitor 42 may include a CCD (Charge-Coupled Device) sensor. The CCD sensor may be used for review. By inserting the mirror M3, the optical paths of the line sensors L1 and L2 and the review monitor 42 are switched.

[0051] FIG. 7 is a plan view illustrating the stage surface ST1 of the stage STG and the wafer WF in the magnetic property measurement apparatus 1 according to Embodiment 1. As shown in FIG. 7, the wafer WF is placed on the stage surface ST1. On the stage surface ST1, the wafer WF is aligned by moving in the X-axis direction and the Y-axis direction and rotating around the Z-axis. In addition, a standard position SP is provided on the stage surface ST1. The standard position SP may be referred to as a predetermined position or a standard point. A sample for preliminary measurement may be installed at the standard position SP. The sample for preliminary measurement may be, for example, a calibration chip.

[0052] Next, a magnetic property measurement method performed using the magnetic property measurement apparatus 1 of the present embodiment will be described. FIG. 8 is a flowchart illustrating the magnetic property measurement method using the magnetic property measurement apparatus 1 according to Embodiment 1. As shown in FIG. 8, the magnetic property measurement method of the present embodiment includes a standard position measurement (Flow I) as a preliminary measurement and a wafer scan (Flow II) as a main measurement. Thus, in the present embodiment, a preliminary measurement and a main measurement are performed. The preliminary measurement may be referred to as a first measurement mode. The main measurement may be referred to as a second measurement mode.

[0053] The preliminary measurement pre-measures the relationship between the characteristics of the frequency and the magnetic field for a sample for preliminary measurement placed at the standard position SP.

[0054] On the other hand, in this measurement, based on the relationship obtained from the preliminary measurement, after selecting a predetermined range of frequencies, the magnetic characteristics of the test object at the frequencies within the predetermined range are measured. For example, while fixing the position of the magnetic field generation unit 20, the magnetic characteristics of the wafer WF are measured by the measurement unit MS while moving the stage STG by the actuator A20. Specifically, the control unit 60 executes a first measurement mode for specifying the resonance frequency of the wafer WF based on the magnetic characteristics of the wafer WF measured by the preliminary measurement. Then, in this measurement, the control unit 60 measures the magnetic characteristics of the wafer WF at the frequencies within the range including the resonance frequency.

[0055] As shown in step S11 of FIG. 8, first, the wafer WF is placed on the magnetic characteristic measuring apparatus 1. Specifically, the wafer transfer robot W1 transfers the wafer WF to be inspected from the wafer supply cassette W3 to the inside of the magnetic characteristic measuring apparatus 1.

[0056] Next, as shown in step S12, the pre-wafer alignment apparatus W2 corrects the rotation angle and shift of the wafer WF. After being adjusted by the pre-wafer alignment apparatus W2, the wafer WF is transferred to the stage STG of the magnetic characteristic measuring apparatus 1.

[0057] Next, as shown in step S13, the wafer WF is aligned on the stage STG. For example, the alignment of the wafer WF is performed using the laser interferometer 14 and the actuator A20. Next, as shown in step S14, the stage STG is moved to the standard position SP. Specifically, in order to measure the sample on the standard position SP, the stage STG is moved so that the optical path falls on the sample. Next, as shown in step S15, a preliminary measurement is performed at the standard position SP.

[0058] Next, as shown in step S16, main measurement is performed by wafer scan. Next, as shown in step S17, post-measurement processing is performed. Then, as shown in step S18, the wafer WF is removed from the stage STG.

[0059] FIG. 9 is a flowchart illustrating a preliminary measurement in the magnetic property measurement method using the magnetic property measurement apparatus 1 according to Embodiment 1. FIG. 10 is a cross-sectional view illustrating the positional relationship among the wafer WF, the magnetic field generation unit 10, and the magnetic field generation unit 20 in the preliminary measurement in the magnetic property measurement method using the magnetic property measurement apparatus 1 according to Embodiment 1. FIG. 11 is a graph illustrating the magnetic properties acquired by the measurement unit MS in the preliminary measurement in the magnetic property measurement method using the magnetic property measurement apparatus 1 according to Embodiment 1, where the horizontal axis indicates the position corresponding to the inclined magnetic field, and the vertical axis indicates the frequency.

[0060] As shown in step S21 of FIG. 9, the stage STG is moved to a predetermined position below the magnetic field generation unit 10 that generates an inclined magnetic field. Specifically, the stage STG is moved to coordinates (X, Y) by the actuator A20 (H = 0). By this movement, alignment is performed between the sample placed at the standard position SP and the magnetic field generation unit 20.

[0061] Next, as shown in step S22, focus adjustment is performed between the sample placed at the standard position SP and the magnetic field generation unit 20 including the electrical signal probe 21. For example, as shown in FIG. 10, the sample SM and the magnetic field generation unit 20 move relative to the magnetic field generation unit 10. Specifically, in the first measurement mode, the control unit 60 moves the magnetic field generation unit 20 together with the sample SM relative to the magnetic field generation unit 10. Thereby, the minimum value Hlow to the maximum value Hup of the inclined magnetic field are applied to the sample SM.

[0062] Next, as shown in step S23, the frequency in the FMR measurement is swept. For example, the frequency is swept from 0 to the maximum value fmax. Thereby, magnetic properties as shown in FIG. 11 are acquired.

[0063] Next, as shown in step S24, it is determined whether the position in the X-axis direction is the maximum. When the position in the X-axis direction does not exceed the maximum position (in the case of No), steps S12 and S13 are continued. That is, the stage STG is moved by the actuator A20. Thereby, the minimum value Hlow to the maximum value Hup of the inclination magnetic field are applied to the sample SM disposed at the standard position SP.

[0064] In step S24, when the position in the X-axis direction exceeds the maximum position (in the case of Yes), as shown in step S25, the resonance frequency fres in each magnetic field is obtained. For example, the resonance frequency fres is obtained from the graph of FIG. 11. In this way, the relationship between the frequency and the magnetic field characteristics in the sample SM disposed at the standard position SP is measured in advance. Note that the resonance frequency fres is assumed to have a linear relationship with respect to the magnetic field.

[0065] FIG. 12 is a graph illustrating the resonance frequency fres in each magnetic field in the magnetic property measuring apparatus 1 according to Embodiment 1. The horizontal axis represents the frequency, and the vertical axis represents the absorption amount. As shown in FIG. 12, the frequencies before and after the resonance frequency fres, that is, the frequency (fres - fm) and the frequency (fres + fp), are selected. The frequency fm and the frequency fp may be selected according to the specifications of the magnetic property measuring apparatus 1. Also, a predetermined width of the peak of the resonance frequency fres is called the resonance frequency width Δfres. For example, the resonance frequency width Δfres may be the half-value width of the peak of the resonance frequency fres or the like.

[0066] FIG. 13 is a graph illustrating the relationship between the resonance frequency fres and the magnetic field in the magnetic property measuring apparatus 1 according to Embodiment 1. The horizontal axis represents the magnetic field, and the vertical axis represents the resonance frequency fres. The resonance frequency fres1 is shown in the case of the magnetic field H1, and the resonance frequency fres2 is shown in the case of the magnetic field H2. As shown in FIG. 13, the resonance frequency fres shows a linear relationship with respect to the magnetic field H.

[0067] FIG. 14 is a graph illustrating the relationship of the resonance frequency width Δfres with respect to a magnetic field in the magnetic property measurement apparatus 1 according to Embodiment 1. The horizontal axis represents the magnetic field, and the vertical axis represents the resonance frequency Δfres. The resonance frequency width Δfres1 is shown for the case of the magnetic field H1, and the resonance frequency width Δfres2 is shown for the case of the magnetic field H2. As shown in FIG. 14, the resonance frequency width Δfres shows a linear relationship with respect to the magnetic field H.

[0068] From FIGS. 13 and 14, for example, as described in Non-Patent Document 1, the anisotropic magnetic field Hk and the damping coefficient α can be obtained by using the Landau-Lifshitz-Gilbert Equation (referred to as the LLG equation). Non-Patent Document 1 will be described later.

[0069] FIG. 15 is a flowchart diagram illustrating this measurement in the magnetic property measurement method using the magnetic property measurement apparatus 1 according to Embodiment 1. FIG. 16 is a cross-sectional view illustrating the positional relationship of the wafer WF, the magnetic field generation unit 10, and the magnetic field generation unit 20 in this measurement in the magnetic property measurement method using the magnetic property measurement apparatus 1 according to Embodiment 1. FIG. 17 is a graph illustrating the magnetic properties acquired by the measurement unit MS in this measurement in the magnetic property measurement method using the magnetic property measurement apparatus 1 according to Embodiment 1. The horizontal axis represents the position corresponding to the inclined magnetic field, and the vertical axis represents the frequency.

[0070] As shown in step S31 of FIG. 15, the magnetic field generation unit 20 including the electrical signal probe 21 is moved to a predetermined position below the magnetic field generation unit 10 that generates an inclined magnetic field.

[0071] Next, as shown in step S32, the wafer WF is scanned in the X-axis direction from the initial position. For example, as shown in FIG. 16, the wafer WF moves relative to the magnetic field generation unit 10 and the magnetic field generation unit 20. The control unit 60 moves the wafer WF relative to the magnetic field generation unit 10 and the magnetic field generation unit 20 in the second measurement mode.

[0072] Next, as shown in step S33, real-time alignment is performed between the wafer WF and the electrical signal probe 21.

[0073] Next, as shown in step S34, the frequency in the FMR measurement is swept. For example, in this measurement, the frequency is swept from (fres2 - fm2) to (fres2 + fp2), and from (fres1 - fm1) to (fres1 + fp1). Thereby, magnetic characteristics as shown in FIG. 17 are obtained.

[0074] Next, as shown in step S35, an image by MOKE may be obtained using the optical system 30. The detector 40 such as TDI acquires the image by MOKE.

[0075] Next, as shown in step S36, it is determined whether the position in the X-axis direction is at the end on the +X-axis direction side or the -X-axis direction side in the X-axis direction of the wafer WF. When the position in the X-axis direction does not exceed the end (in the case of No), the position of the stage STG is moved by ΔX, and steps S33 to S35 are continued.

[0076] In step S36, when the position in the X-axis direction exceeds the end in the X-axis direction of the wafer WF (in the case of Yes), as shown in step S37, it is determined whether the position in the Y-axis direction is at the end on the +Y-axis direction side in the Y-axis direction of the wafer WF. In step S37, when the position in the Y-axis direction does not exceed the end (in the case of No), the position of the stage STG is moved to the next row, and steps S33 to S36 are continued.

[0077] In step S37, when the position in the Y-axis direction exceeds the end in the Y-axis direction of the wafer WF (in the case of Yes), the process is terminated.

[0078] FIG. 18 is a graph illustrating the resonance frequency fres in each magnetic field in the magnetic characteristic measurement device 1 according to Embodiment 1. The horizontal axis represents the frequency, and the vertical axis represents the absorption amount. As shown in FIG. 18, a signal Sig having the resonance frequency fres obtained by this measurement as a peakres From this, the resonance frequency width Δfres can be obtained. Therefore, in this measurement, by scanning the entire wafer WF, the anisotropic magnetic field Hk and the damping coefficient α of each MRAM element can be obtained. Specifically, for example, as described in Non-Patent Document 1, the anisotropic magnetic field Hk can be obtained from the FMR measurement signal in FIG. 18. Here, in Equation (1) of Non-Patent Document 1, the anisotropic magnetic field Hk is shown as Hk eff (anisotropy field), and in Equation (2), the damping coefficient α is shown as α (danping constant). Note that Equation (1) of Non-Patent Document 1 includes the Lande g factor, the permeability μ0 in vacuum, the Bohr magnet μ b , the Planck constant h, and the out-of-plane magnetic field μ0Hout. The graphs in FIGS. 1(b) and 1(c) of Non-Patent Document 1 are examples of the derivation of the anisotropic magnetic field Hk and the damping coefficient α.

[0079] FIG. 19 is a sequence diagram illustrating a method for measuring the magnetic characteristics of a die DIE included in a wafer WF according to Embodiment 1. The horizontal axis represents time, and from top to bottom, it shows the current of the electromagnet, the inspection swath, the moving direction (Direction) of the wafer WF, the inspection period (Die) of the die DIE, the image capture clock (LRC) of the TDI, and the sweep pulse (Signal Probe) from the frequency (fres - fm) to the frequency (fres + fp).

[0080] The wafer WF has rectangular spatially repetitive periodic MRAM elements called dies DIE formed thereon. Inside the MRAM element, a repetitive periodic storage region is formed in an array. During the measurement by the line sensor 41, the movement is such that an image is acquired in the forward direction while moving in the X-axis direction across a plurality of dies DIE as shown in FIG. 7. Once the image acquisition is completed, it moves in the Y-axis direction to the next measurement position and performs the inspection from the reverse direction of the X-axis. As shown in FIG. 7, when inspecting all the dies DIE of the wafer WF, the moving direction of the line sensor 41 is repeatedly alternated between the forward direction and the reverse direction. Then, the image is acquired without gaps including the filter processing and several pixels for scan correction.

[0081] For example, when the image capture clock LRC of TDI is 400 kHz and the sweep pulse is 10 GHz, the number of sweep pulses is (10 10 ) / (400 × 10 3 ) = 25000 pulses / LRC. In the example of FIG. 19, the number of sweep pulses is shown so as to fit within one clock of LRC, but the repetition period of the sweep pulses may be adjusted so as to fit within two or more clocks of LRC.

[0082] FIG. 20 is an image diagram illustrating regions S1 and S2 on the measurement surface Z0 detected by a plurality of line sensors L1 and L2 in the magnetic property measurement apparatus 1 according to Embodiment 1. As shown in FIG. 20, the plurality of line sensors L1 and L2 each detect regions S1 and S2 extending in the Y-axis direction. Regions S1 and S2 have lengths d1 and d2 in the X-axis direction and a length W in the Y-axis direction. Regions S1 and S2 are arranged side by side with a gap gap in the X-axis direction.

[0083] FIG. 21 is a graph illustrating the magnetic field component in the Z-axis direction on the measurement surface Z0 in the magnetic property measurement apparatus 1 according to Embodiment 1. The horizontal axis indicates the position in the X-axis direction on the measurement surface Z0, and the vertical axis indicates the magnetic field component in the Z-axis direction on the measurement surface Z0. FIG. 21 also shows regions S1 and S2 on the measurement surface Z0 measured by each line sensor. FIG. 22 is a graph illustrating the Kerr rotation angle on the measurement surface Z0 in the magnetic property measurement apparatus 1 according to Embodiment 1. The horizontal axis indicates the magnetic field component in the Z-axis direction of the external magnetic field, and the vertical axis indicates the Kerr rotation angle. FIG. 22 also schematically shows the luminance of a plurality of MRAM elements.

[0084] As shown in FIGS. 21 and 22, at time t = t0, the MRAM element is located in a region where the magnetic field component in the Z-axis direction is 0. When the MRAM element is moved in the X-axis direction, the external magnetic field received by the MRAM element increases. As a result, the Kerr rotation angle also increases. However, the Kerr rotation angle saturates when it reaches a certain value and does not change even if the external magnetic field is increased (time t = t1). The line sensor L2 acquires the luminance due to the Kerr rotation angle of a plurality of magnetoresistive memory elements MRAM arranged in the Y-axis direction at time t = t1.

[0085] Furthermore, when the MRAM element is moved in the X-axis direction, the external magnetic field received by the MRAM element decreases. As a result, the Kerr rotation angle also decreases. Then, the external magnetic field becomes 0. Furthermore, when the MRAM element is moved in the X-axis direction, the external magnetic field received by the MRAM element becomes reverse. As a result, the Kerr rotation angle decreases. Then, when the MRAM element is moved in the X-axis direction, the reverse external magnetic field received by the MRAM element increases. As a result, the Kerr rotation angle becomes even smaller.

[0086] At time t = t2, when the reverse external magnetic field increases, the Kerr rotation angle decreases and the luminance also decreases. The line sensor L1 acquires the luminance due to the Kerr rotation angle of a plurality of MRAM elements arranged in the Y-axis direction at time t = t2. Furthermore, when the MRAM element is moved in the X-axis direction, the reverse external magnetic field received by the MRAM element decreases. Then, the external magnetic field becomes 0.

[0087] As shown in FIG. 22, in the present embodiment, the line sensor L2 acquires the luminance of a plurality of MRAM elements at time t = t1. Also, the line sensor L1 acquires the luminance of a plurality of MRAM elements at time t = t2. Thus, in the present embodiment, the line sensor L2 detects the magneto-optical effect at the position of the MRAM element at time t = t1 by moving the position of the MRAM element in the inclined magnetic field. The line sensor L1 detects the magneto-optical effect at the position of the MRAM element at time t = t2. Therefore, the plurality of line sensors L2 and L1 respectively detect the magneto-optical effect due to the magnetic field component in the +Z-axis direction and the magneto-optical effect due to the magnetic field component in the -Z-axis direction.

[0088] When there are defects in a plurality of MRAM elements arranged in the Y-axis direction at time t = t1, the line sensor L2 detects the luminance of the defects. The defective MRAM element exhibits a luminance different from that of the adjacent normal MRAM element. Also, when there are defects in a plurality of MRAM elements arranged in the Y-axis direction at time t = t2, the line sensor L1 detects the luminance of the defects. The defective MRAM element exhibits a luminance different from that of the adjacent normal MRAM element.

[0089] The information processing unit 50 processes the magneto-optical effects detected by the plurality of line sensors L1 and L2. Specifically, the information processing unit 50 inspects the MRAM element from the difference between the magneto-optical effect detected by the line sensor L1 and the magneto-optical effect detected by the line sensor L2. For example, the information processing unit 50 detects the difference Diff between the luminance of the defective MRAM element at time t = t1 detected by the line sensor L2 and the luminance of the defective MRAM element at time t = t2 detected by the line sensor L1. Thus, the information processing unit 50 compares the luminances of the same MRAM element at different times t1 and t2.

[0090] Note that the information processing unit 50 may detect the difference diff between the luminance of the defect detected by the line sensor L1 and the luminance of an adjacent normal MRAM element, or may detect the difference diff between the luminance of the defect detected by the line sensor L2 and the luminance of an adjacent normal MRAM element. Further, the information processing unit 50 may process the magnetoresistive effects detected by three or more line sensors, not limited to the two line sensors L1 and L2.

[0091] Next, the effects of this embodiment will be described. The magnetic property measuring apparatus 1 of this embodiment includes a magnetic field generating unit 10 and a magnetic field generating unit 20, and can measure the resonance frequency for obtaining the anisotropic magnetic field Hk and the damping coefficient α by FMR. Then, the magnetic property measuring apparatus 1 can narrow down in advance the resonance frequency and the magnetic field characteristics measured in this measurement in a preliminary measurement. Thereby, the measurement time can be shortened.

[0092] Further, the magnetic property measuring apparatus 1 can measure an image by MOKE simultaneously and at high speed with the measurement of the anisotropic magnetic field Hk and the damping coefficient α by FMR. Thereby, defects on the wafer WF can be detected with high accuracy.

[0093] The magnetic property measuring apparatus 1 of this embodiment has an inclined magnetic field. The inclined magnetic field has a magnetic field component that changes from the +Z-axis direction to the -Z-axis direction depending on the position of the measurement plane Z0. The inclined magnetic field is constant in time and varies by location. By moving within such an inclined magnetic field, the magnetic field applied to the MRAM element is changed. For this reason, the distribution of the magnetic field generated by the electromagnet may be constant as an inclined magnetic field. Therefore, it is not necessary to change the current flowing through the coil of the electromagnet during inspection. Thus, the measurement speed due to the responsiveness of the electromagnet does not decrease, so the measurement time can be shortened and the throughput can be improved.

[0094] Also, the magnetization distribution of the MRAM element is monitored as an image and integrated using the measurement results of a line sensor 41 such as a TDI camera. For this reason, highly sensitive measurement is possible, and the long-time imaging that has been performed so far is unnecessary. In this way, by using two or more line sensors 41 and a magnetic field generation unit 10 that generates an inclined magnetic field with respect to the MRAM element, the measurement time can be shortened and the defect detection ability can be improved.

[0095] Furthermore, the magnetic property measurement apparatus 1 can measure the hysteresis distribution by changing the shape of the magnetic field distribution to a vertical magnetic field distribution by independently switching the directions of the currents in a plurality of electromagnets.

[0096] (Embodiment 2) Next, a magnetic property measurement apparatus according to Embodiment 2 will be described. In the magnetic property measurement apparatus of this embodiment, the stage STG has a plate member containing a magnetic material embedded therein. FIG. 23 is a cross-sectional view illustrating the stage STG and the magnetic field generation unit 10 in the magnetic property measurement apparatus 2 according to Embodiment 2. As shown in FIG. 23, the stage STG in the magnetic property measurement apparatus 2 includes a plate member 15. The plate member 15 contains a magnetic material. The plate member 15 may be, for example, an iron plate. Note that the plate member 15 is not limited to an iron plate as long as it contains a magnetic material. The plate member 15 is embedded inside the stage STG and is not exposed on the stage surface ST1.

[0097] When viewed from a direction perpendicular to the stage surface ST1, the region surrounded by the outer edge of the plate member 15 includes a magnetoresistive memory element MRAM fixed to the stage surface ST1. For example, when viewed from a direction perpendicular to the stage surface ST1, the area of the region surrounded by the outer edge of the plate member 15 is larger than the area of the wafer WF including the MRAM element fixed to the stage surface ST1.

[0098] When the wafer WF includes a plurality of MRAM elements and the wafer WF is fixed to the stage surface ST1, the region surrounded by the outer edge of the plate member 15 includes the wafer WF fixed to the stage surface ST1 when viewed from a direction orthogonal to the stage surface ST1. For example, when viewed from a direction orthogonal to the stage surface ST1, the area of the region surrounded by the outer edge of the plate member 15 is larger than the area of the wafer WF fixed to the stage surface ST1. By adopting such a configuration, the inclined magnetic field can be stabilized. Other configurations and effects in Embodiment 2 are included in the description of Embodiment 1.

[0099] (Embodiment 3) Next, a magnetic property measuring apparatus according to Embodiment 3 will be described. In the present embodiment, the stage STG rotates about a rotation axis orthogonal to the stage surface ST1. Therefore, the stage STG rotates and moves the MRAM element about a rotation axis orthogonal to the measurement surface Z0. FIG. 24 is a perspective view illustrating the stage STG and the magnetic field generation unit 10 in the magnetic property measuring apparatus 3 according to Embodiment 3. As shown in FIG. 24, the stage STG in the magnetic property measuring apparatus 3 is, for example, disk-shaped. The stage STG has a stage surface ST1 and rotates about a rotation axis C orthogonal to the stage surface ST1. The direction opposite to the rotation direction of the clock hand about the rotation axis C is defined as the +θ direction. In FIG. 24, the magnetic field generation unit 20 and the like are omitted so that the figure does not become complicated.

[0100] The two electromagnets 11 and 12 are disposed above the stage surface STG. The central position between the electromagnet 11 and the electromagnet 12 is fixed. However, the distance between the electromagnet 11 and the electromagnet 12 can be extended and contracted. For example, when the central position between the electromagnet 11 and the electromagnet 12 is fixed on the rotation axis C, the electromagnet 11 and the electromagnet 12 can be extended and contracted in the radial direction of the stage STG. Therefore, the two electromagnets 11 and 12 adjust the mutual distance based on the position of the MRAM element to be measured to generate an inclined magnetic field. Note that the central position between the electromagnet 11 and the electromagnet 12 is not limited to being on the rotation axis C.

[0101] When the center of the wafer WF is placed on the rotation axis C, the plurality of line sensors 41 measure the magnetic field characteristics by the electromagnets 11 and 12, respectively. Each line sensor 41 can measure the magnetic field characteristics by the magnetic field (+H) in the +Z-axis direction and the magnetic field (-H) in the -Z-axis direction when the wafer WF makes one revolution. The measurement region SR is an annular shape centered on the rotation axis C on the inspection surface W0.

[0102] Let the distance from the center of the wafer WF to the electromagnet 11 (or the electromagnet 12) be r. The linear speed v in the tangential direction of the measurement region SR depends on the distance r from the center of the wafer WF. That is, in v = rω, the angular velocity ω is adjusted so as to match the scan speed of the line sensor 41 such as TDI. Thereby, the line sensor 41 acquires an image of the magneto-optical effect. According to the present embodiment, by applying the rotating stage STG, there are merits such as saving the folding time compared to the XY stage and not having to control the integration direction of the line sensor 41 such as TDI with respect to the scan direction. Some modified examples of Embodiment 3 will be shown below.

[0103] (Modified Example 1) FIG. 25 is a plan view illustrating the arrangement of the stage STG, the electromagnets 11 and 12, and the line sensors L1 and L2 in the magnetic property measuring apparatus 3a according to Modified Example 1 of Embodiment 3. As shown in FIG. 25, in the magnetic property measuring apparatus 3a of this modified example, the center position between the electromagnet 11 and the electromagnet 12 on the stage surface ST1 is located between the rotation axis C and the periphery on the +X-axis direction side of the stage surface ST1. The electromagnet 11 is arranged on the +Y-axis direction side of the center position, and the electromagnet 12 is arranged on the -Y-axis direction side of the center position. The inclined magnetic field is formed along the Y-axis direction.

[0104] The plurality of line sensors L1 and L2 are arranged between the electromagnet 11 and the electromagnet 12. The plurality of line sensors L1 and L2 extend in the X-axis direction. When the stage STG rotates, the plurality of line sensors L1 and L2 measure an annular measurement region SR having the measurement width of the line sensor 41 as the width.

[0105] FIG. 26 is a graph illustrating the magnetic field component in the Z-axis direction on the measurement plane Z0 in the magnetic property measurement device 3a according to Modification 1 of Embodiment 3. The horizontal axis represents the position in the Y-axis direction on the measurement plane Z0, and the vertical axis represents the magnetic field component in the Z-axis direction on the measurement plane Z0. FIG. 27 is a graph illustrating the Kerr rotation angle on the measurement plane Z0 in the magnetic property measurement device 3a according to Modification 1 of Embodiment 3. The horizontal axis represents the magnetic field component in the Z-axis direction of the external magnetic field, and the vertical axis represents the Kerr rotation angle.

[0106] As shown in FIGS. 26 and 27, at time t = t0, the MRAM element is located in a region where the magnetic field component in the Z-axis direction is 0. When the MRAM element is moved in the +θ direction, the external magnetic field received by the MRAM element increases. As a result, the Kerr rotation angle also increases. However, the Kerr rotation angle saturates when it reaches a certain value and does not change even if the external magnetic field is increased (time t = t1). The line sensor L2 acquires the luminance due to the Kerr rotation angle of a plurality of MRAM elements arranged in the radial direction at time t = t1.

[0107] Furthermore, when the MRAM element is moved in the +θ direction, the external magnetic field received by the MRAM element decreases. As a result, the Kerr rotation angle decreases. Then, the external magnetic field becomes 0. Furthermore, when the MRAM element is moved in the +θ direction, the external magnetic field received by the MRAM element becomes reverse. As a result, the Kerr rotation angle decreases. Then, when the MRAM element is moved in the +θ direction, the reverse external magnetic field received by the MRAM element increases. As a result, the Kerr rotation angle further decreases.

[0108] At time t = t2, when the reverse external magnetic field increases, the Kerr rotation angle decreases. The line sensor L1 acquires the luminance due to the Kerr rotation angle of a plurality of MRAM elements arranged in the radial direction at time t = t2. Further, when the MRAM element is moved in the +θ direction, the reverse external magnetic field received by the MRAM element decreases. Then, the external magnetic field becomes zero.

[0109] As shown in FIG. 26, in the present embodiment, the line sensor L2 acquires the luminance of a plurality of MRAM elements at time t = t1. Also, the line sensor L1 acquires the luminance of a plurality of MRAM elements at time t = t2. The information processing unit 50 detects the difference Diff between the luminance of the defective MRAM element at time t = t1 and the luminance of the defective MRAM element at time t = t2.

[0110] (Modification 2) Next, a magnetic property measuring apparatus according to Modification 2 of Embodiment 3 will be described. FIG. 28 is a plan view illustrating the arrangement of the stage STG, the electromagnets 11 and 12, and the line sensors L1 and L2 in the magnetic property measuring apparatus 3b according to Modification 2 of Embodiment 3. As shown in FIG. 28, in the magnetic property measuring apparatus 3b, the central position between the electromagnet 11 and the electromagnet 12 on the stage surface STG is located on the rotation axis C. The electromagnet 11 is arranged on the -X-axis direction side of the rotation axis C, and the electromagnet 12 is arranged on the +X-axis direction side of the rotation axis C. The inclined magnetic field is formed along the X-axis direction.

[0111] The plurality of line sensors L1 and L2 are arranged on the +Y-axis direction side and the -Y-axis direction side of the rotation axis C. The plurality of line sensors L1 and L2 extend in the Y-axis direction. The electromagnet 11, the electromagnet 12, the line sensor L1, and the line sensor L2 are located at an equal distance from the rotation axis C. Therefore, the electromagnet 11, the line sensor L1, the electromagnet 12, and the line sensor L2 are arranged at equal intervals on the circumference centered on the rotation axis. When the stage STG rotates, the plurality of line sensors L1 and L2 measure an annular measurement region SR having the measurement width of the line sensor 41.

[0112] FIG. 29 is a graph illustrating the magnetic field component in the Z-axis direction on the measurement plane Z0 in the magnetic property measurement apparatus 3b according to Modification 2 of Embodiment 3. The horizontal axis indicates the position on the measurement region SR shown by the angle around the rotation axis C, and the vertical axis indicates the magnetic field component in the Z-axis direction on the measurement plane Z0. FIG. 30 is a graph illustrating the Kerr rotation angle on the measurement plane Z0 in the magnetic property measurement apparatus 3b according to Modification 2 of Embodiment 3. The horizontal axis indicates the magnetic field component in the Z-axis direction of the external magnetic field, and the vertical axis indicates the Kerr rotation angle.

[0113] As shown in FIGS. 29 and 30, at the position of θ = 0 on the measurement plane Z0, the MRAM element is directly below the electromagnet 12. Therefore, the MRAM element is located in a region where the magnetic field component in the +Z-axis direction is large. When the MRAM element is moved in the +θ direction, the external magnetic field received by the MRAM element becomes smaller. As a result, the Kerr rotation angle also becomes smaller. At θ = π / 2, the external magnetic field becomes 0. The line sensor L1 acquires the luminance based on the Kerr rotation angle of a plurality of MRAM elements arranged in the radial direction at θ = π / 2.

[0114] Furthermore, when the MRAM element is moved in the θ direction, the reverse external magnetic field received by the MRAM element becomes larger. As a result, the Kerr rotation angle becomes smaller. At θ = π, the MRAM element is directly below the electromagnet 11. Therefore, the MRAM element is located in a region where the reverse magnetic field component is large. Furthermore, when the MRAM element is moved in the +θ direction, the reverse magnetic field component received by the MRAM element becomes smaller. At θ = 3π / 2, the external magnetic field becomes 0. The line sensor L2 acquires the luminance based on the Kerr rotation angle of a plurality of MRAM elements arranged in the radial direction at θ = 3π / 2. The information processing unit 50 detects the difference Diff between the luminance of the defective MRAM element at θ = π / 2 and the luminance of the defective MRAM element at θ = 3π / 2.

[0115] (Modification 3) Next, a magnetic property measurement apparatus according to Modification 3 of Embodiment 3 will be described. FIG. 31 is a plan view illustrating the arrangement of a stage STG, electromagnets 11 and 12, and line sensors L1 and L2 in a magnetic property measurement apparatus 3c according to Modification 3 of Embodiment 3. As shown in FIG. 31, in the magnetic property measurement apparatus 3c, the central position between the electromagnet 11 and the electromagnet 12 on the stage surface ST1 is located on the rotation axis C. The electromagnet 11 is arranged on the -X-axis direction side of the rotation axis C, and the electromagnet 12 is arranged on the +X-axis direction side of the rotation axis C. The inclined magnetic field is formed along the X-axis direction.

[0116] The line sensor L1 is arranged slightly on the +θ direction side of the electromagnet 11, and the line sensor L2 is arranged slightly on the +θ direction side of the electromagnet 12. The plurality of line sensors L1 and L2 extend in the X-axis direction. When the stage STG rotates, the plurality of line sensors L1 and L2 measure an annular measurement region SR having the measurement width of the line sensor 41 as the width.

[0117] FIG. 32 is a graph illustrating the magnetic field component in the Z-axis direction on the measurement plane Z0 in the magnetic property measurement apparatus 3c according to Modification 3 of Embodiment 3. The horizontal axis represents the position on the measurement region SR indicated by the angle around the rotation axis C, and the vertical axis represents the magnetic field component in the Z-axis direction on the measurement plane Z0. FIG. 33 is a graph illustrating the Kerr rotation angle on the measurement plane Z0 in the magnetic property measurement apparatus 3c according to Modification 2 of Embodiment 3. The horizontal axis represents the magnetic field component in the Z-axis direction of the external magnetic field, and the vertical axis represents the Kerr rotation angle.

[0118] As shown in FIGS. 32 and 33, at the position where θ = 0 on the measurement plane Z0, the MRAM element is directly below the electromagnet 12. Therefore, the MRAM element is located in a region where the magnetic field component in the +Z-axis direction is large. The line sensor L2 acquires the luminance based on the Kerr rotation angle of a plurality of MRAM elements arranged in the radial direction slightly shifted in the +θ direction from the electromagnet 12.

[0119] When the MRAM element is further moved in the +θ direction, the external magnetic field received by the MRAM element becomes smaller. As a result, the Kerr rotation angle becomes smaller. At θ = π / 2, the external magnetic field becomes zero. Further, when the MRAM element is moved in the +θ direction, the reverse external magnetic field received by the MRAM element becomes larger. As a result, the Kerr rotation angle becomes smaller.

[0120] At θ = π, the MRAM element is directly below the electromagnet 11. Therefore, the MRAM element is located in a region where the reverse magnetic field component is large. The line sensor L1 acquires the luminance due to the Kerr rotation angle of a plurality of MRAM elements arranged radially, slightly moved in the +θ direction from the electromagnet 11.

[0121] Furthermore, when the MRAM element is moved in the +θ direction, the reverse magnetic field component received by the MRAM element becomes smaller. At θ = 3π / 2, the external magnetic field becomes zero. The information processing unit 50 detects the difference Diff between the luminance of the defective MRAM element at a position slightly in the +θ direction from θ = 0 and the luminance of the defective MRAM element at a position slightly in the +θ direction from θ = π. Other configurations and effects in Embodiment 3 and Modifications 1 to 3 are included in the descriptions of Embodiments 1 and 2.

[0122] Note that the present disclosure is not limited to the above embodiments, and can be appropriately changed without departing from the gist. For example, a combination of the configurations of Embodiments 1 to 3 and Modifications 1 to 3 is also within the scope of the technical idea of the present invention.

Explanation of Signs

[0123] 1, 2, 3, 3a, 3b, 3c Magnetic property measurement device 10 Magnetic field generation unit 11, 12 Electromagnet 13 Frame 14 Laser interferometer 15 Plate member 20, 20a Magnetic field generation unit 21, 21a, 21b, 21c, 21d, 21e, 21f Electric signal probe 22 Base material 23 Microwave generator 24 Height sensor 25 Slit 30 Optical system 31 Light source 32 Filter 33 Polarizer 34 Objective lens 35 Analyzer 36 Filter 37 AF sensor 40 Detector 41 Line sensor 42 Review monitor 50 Information processing unit 60 Power supply and control unit B1 Granite surface plate B2 Active vibration isolation table B3 Wedge B4 Diffuser C Rotation axis DIE Die SR Measurement area A10, A20, A30 Actuator MS Measurement unit SP Standard position STG Stage ST1 Stage surface W1 Wafer transfer robot W2 Pre-wafer alignment device W3 Wafer supply cassette WF Wafer Z0 Measurement surface

Claims

1. A first magnetic field generation unit that generates an inclined magnetic field with different magnetic fields depending on the location, A second magnetic field generation unit that generates a temporally variable high-frequency magnetic field, A first actuator that moves the second magnetic field generation unit, A mounting table for mounting the test subject, A second actuator that moves the mounting table, A measurement unit that measures the magnetic properties of the test subject moving in the inclined magnetic field, A magnetic property measurement device comprising the above.

2. A light source that generates light, A polarizer that converts the generated light into linearly polarized light, An objective lens that forms an image of the light on the test subject, An unpolarized beam splitter that separates the light, An analyzer that detects the rotation component in the linearly polarized light of the light, A line sensor that acquires a scan image obtained by scanning the light on the test subject, Further comprising the above, The magnetic property measurement device according to claim 1, which measures the magnetic properties and measures the polarization state of the light.

3. A preliminary measurement for preliminarily measuring the relationship between the frequency and the characteristics of the magnetic field for a sample for preliminary measurement, and based on the relationship obtained from the preliminary measurement, after selecting a predetermined range of the frequency, a main measurement for measuring the magnetic properties of the test subject at the frequency within the predetermined range is performed. The magnetic property measurement device according to claim 1 or 2.

4. Further comprising a control unit that controls the first magnetic field generation unit, the second magnetic field generation unit, the first actuator, and the second actuator, The control unit, A first measurement mode in which the second magnetic field generation unit is moved by the first actuator and the mounting table is moved by the second actuator while the magnetic properties of the test subject are measured by the measurement unit, A second measurement mode in which the magnetic properties of the test subject are measured by the measurement unit while the mounting table is moved by the second actuator while the position of the second magnetic field generation unit is fixed, Executing the above, The magnetic property measurement device according to claim 1 or 2.

5. The control unit further executes a mode for specifying the resonance frequency of the test subject based on the magnetic properties of the test subject measured in the first measurement mode, In the second measurement mode, the magnetic properties of the test subject at frequencies within a range including the resonance frequency are measured. The magnetic property measurement device according to claim 4.

6. ​ the second magnetic field generating unit includes a slit arranged so that an optical path between the objective lens and the test object is conductive; The magnetic characteristic measuring device according to claim 2 .

7. the first magnetic field generating unit includes two or more magnet units, an optical path between the objective lens and the test object is disposed between the two or more magnet units; The magnetic characteristic measuring device according to claim 2 .

8. The gradient magnetic field is a static magnetic field.

3. The magnetic characteristic measuring device according to claim 1 or 2.

9. The measurement of the magnetic properties is carried out under atmospheric pressure.

3. The magnetic characteristic measuring device according to claim 1 or 2.

10. Further, a temperature control unit is provided to control the temperature of the test object.

3. The magnetic characteristic measuring device according to claim 1 or 2.

11. Further provided is a third actuator that moves the first magnetic field generation unit.

3. The magnetic characteristic measuring device according to claim 1 or 2.

12. The control unit In the first measurement mode, the second magnetic field generating unit is moved together with the test object relative to the first magnetic field generating unit; In the second measurement mode, the test subject is moved relative to the second magnetic field generation unit and the first magnetic field generation unit. The magnetic characteristic measuring device according to claim 4.

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