Inspection Equipment

Abstract

To provide an inspection device having higher throughput by shortening a measurement time.SOLUTION: An inspection device 1 includes: a stage 10 with a stage surface 13, on which a magnetoresistive memory element MRAM is fixed on the stage surface 13 and the magnetoresistive memory element MRAM is moved within an inspection plane W0 that is parallel to the stage surface 13; a plurality of magnets 20 that generates a gradient magnetic field whose direction of a magnetic field component in a direction orthogonal to the inspection plane W0 changes from a +Z-axis direction to a -Z-axis direction depending on the position of the inspection plane W0; a plurality of line sensors 41 including a line sensor L1 that detects a magneto-optic effect at a first position of the magnetoresistive memory element MRAM and a line sensor L2 that detects a magneto-optic effect at a second position of the magnetoresistive memory element MRAM by moving the position of the magnetoresistive memory element MRAM in the gradient magnetic field; and an information processing unit 50 that processes the magneto-optic effect detected by the line sensors 41.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an inspection apparatus, for example, an inspection apparatus for inspecting the magnetic characteristics of a magnetoresistive memory element at high speed and with high sensitivity. [Background technology]

[0002] A semiconductor memory element called magnetoresistive random access memory (MRAM) is a non-volatile memory that uses magnetic tunnel junctions (MTJs) as its component. In a semiconductor production line, early inspection of magnetoresistive memories formed on a wafer before the completion of magnetoresistive memory devices (MRAM devices) is important for improving the production yield of magnetoresistive memory devices. In order to inspect magnetoresistive memory devices before their completion, it is necessary to understand their magnetic field characteristics as well as non-destructive appearance inspection using optical microscopes and electron beams. As a high-speed measurement method for magnetic field measurement, 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 the magnetic hysteresis loop at the measurement point can be obtained by changing the intensity of the magnetic field and measuring the change in polarization of the reflected light. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 06-317638 Summary of the Invention [Problem to be solved by the invention]

[0004] However, since it takes, for example, 10 to 30 seconds to apply an external magnetic field to each measurement point and obtain a magnetic hysteresis loop, it takes a long time to measure a semiconductor wafer including a large number of magnetoresistive memories.

[0005] An object of the present invention is to provide an inspection apparatus capable of shortening the measurement time and improving the throughput. [Means for solving the problem]

[0006] An inspection apparatus according to an embodiment includes: a stage having a stage surface, the stage fixing a magnetoresistive memory element to the stage surface and moving the magnetoresistive memory element within an inspection surface parallel to the stage surface; a plurality of magnets that generate gradient magnetic fields in which a direction of a magnetic field component perpendicular to the examination surface changes from a first direction to a second direction opposite to the first direction depending on a position of the examination surface; a plurality of line sensors including a first line sensor that detects a magneto-optical effect at a first position of the magneto-resistance memory element by moving the position of the magneto-resistance memory element within the gradient magnetic field, and a second line sensor that detects the magneto-optical effect at a second position different from the first position; an information processing unit that processes the magneto-optical effect detected by the plurality of line sensors; Equipped with.

[0007] With this configuration, it is possible to provide an inspection apparatus that can shorten the measurement time and improve the throughput.

[0008] In the above inspection device, The multiple line sensors may include a line sensor that detects at least one of the magneto-optical effect caused by the magnetic field component in the first direction, the magneto-optical effect caused by the magnetic field component in the second direction, and the magneto-optical effect caused by a magnetic field component in a direction perpendicular to the inspection surface being 0.

[0009] In the above inspection device, The information processing section may inspect the magnetoresistive memory element from a difference between the magneto-optical effect detected by the first line sensor and the magneto-optical effect detected by the second line sensor.

[0010] In the above inspection device, The stage has a plate member including a magnetic material embedded therein, When viewed from a direction perpendicular to the stage surface, an area surrounded by an outer edge of the plate member may include the magnetoresistive memory element fixed to the stage surface.

[0011] In the above inspection device, A wafer is fixed to the stage surface, The wafer includes a plurality of the magnetoresistive memory elements or a perpendicular magnetization solid film before a memory element forming process, The stage has a plate member including a magnetic material embedded therein, When viewed from a direction perpendicular to the stage surface, a region surrounded by an outer edge of the magnetic body may include the wafer fixed to the stage surface.

[0012] In the above inspection device, The plurality of magnets may include two electromagnets having independently controlled electrical currents applied thereto.

[0013] In the above inspection device, The stage may move the magnetoresistive memory element or the perpendicular magnetization solid film prior to a memory element forming process linearly along one direction within the inspection surface.

[0014] In the above inspection device, The stage may rotate the magnetoresistive memory element or the perpendicularly magnetized solid film prior to the memory element forming process about a rotation axis perpendicular to the inspection surface.

[0015] In the above inspection device, A wafer is fixed to the stage surface, The wafer includes a plurality of the magnetoresistive memory elements or a perpendicular magnetization solid film before a memory element forming process, The plurality of magnets may generate the gradient magnetic field by adjusting the mutual spacing based on the position of the magnetoresistive memory element or the perpendicular magnetization solid film to be inspected.

[0016] In the above inspection device, The first line sensor and the second line sensor may include a TDI. Effect of the Invention

[0017] According to the inspection device of the present invention, it is possible to reduce the measurement time and improve the throughput. [Brief description of the drawings]

[0018] [Figure 1] 1 is a configuration diagram illustrating an inspection device according to a first embodiment. [Diagram 2] 3 is a diagram illustrating a magnet of the inspection device according to the first embodiment. FIG. [Diagram 3] 1 is a graph illustrating the magnetic field components in the Z-axis direction of the magnetic lines on the inspection surface in the inspection device of embodiment 1, where the horizontal axis indicates the position in the X-axis direction on the inspection surface and the vertical axis indicates the magnetic field components in the Z-axis direction of the magnetic lines on the inspection surface. [Figure 4] 4 is a flow chart illustrating a method for transporting a wafer to be inspected in the inspection device according to the first embodiment. FIG. [Diagram 5] 1 is a plan view illustrating a wafer according to a first embodiment. [Figure 6] FIG. 1 is a sequence diagram illustrating a method for inspecting a die included in a wafer according to embodiment 1, in which the horizontal axis indicates time and the vertical axis indicates the magnet current, the inspection zone, the wafer movement direction, the die inspection period, and a signal LRC for synchronizing the moving stage and the camera. [Figure 7] 1 is a diagram illustrating the magnetic characteristics of a magnetoresistive memory element, in which the horizontal axis indicates an external magnetic field and the vertical axis indicates the Kerr rotation angle. [Figure 8]1 is a diagram illustrating the magnetic characteristics of a magnetoresistive memory element, in which the horizontal axis indicates an external magnetic field and the vertical axis indicates the Kerr rotation angle. [Figure 9] 11 is an image diagram illustrating an area on an inspection surface detected by one line sensor in an inspection device according to a comparative example. FIG. [Figure 10] This is a graph illustrating the magnetic field components in the Z-axis direction on the inspection surface in a comparative inspection device, where the horizontal axis indicates the position in the X-axis direction on the inspection surface and the vertical axis indicates the magnetic field components in the Z-axis direction on the inspection surface. [Figure 11] 11 is a graph illustrating the Kerr rotation angle on the inspection surface in the inspection device according to the comparative example, where 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. [Figure 12] 3 is an image diagram illustrating an example of an area on an inspection surface detected by a plurality of line sensors in the inspection device according to the first embodiment. FIG. [Figure 13] 1 is a graph illustrating magnetic field components in the Z-axis direction on an inspection surface in an inspection device according to embodiment 1, where the horizontal axis indicates the position in the X-axis direction on the inspection surface and the vertical axis indicates the magnetic field components in the Z-axis direction on the inspection surface. [Figure 14] 4 is a graph illustrating the Kerr rotation angle on the inspection surface in the inspection device according to the first embodiment, where 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. [Figure 15] 4 is a graph illustrating the Kerr rotation angle in the inspection device according to the first embodiment, where 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. [Figure 16] 1 is a graph illustrating the gray value of a magnetoresistive memory element in the inspection device 1 according to the first embodiment, where the horizontal axis indicates the magnetoresistive memory element and the vertical axis indicates the gray value. [Figure 17] 11 is a cross-sectional view illustrating a stage and a magnet in an inspection device according to a second embodiment. FIG. [Figure 18] FIG. 11 is a perspective view illustrating a stage and a magnet in an inspection device according to a third embodiment. [Figure 19]13 is a plan view illustrating an example of the arrangement of a stage, a magnet, and a line sensor in an inspection device according to a first modified example of the third embodiment. FIG. [Figure 20] This is a graph illustrating the magnetic field components in the Z-axis direction on the inspection surface in an inspection device related to variant example 1 of embodiment 3, where the horizontal axis indicates the position in the Y-axis direction on the inspection surface and the vertical axis indicates the magnetic field components in the Z-axis direction on the inspection surface. [Figure 21] 11 is a graph illustrating the Kerr rotation angle on the inspection surface in the inspection device according to the first modification of the third embodiment, where 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. [Figure 22] 13 is a plan view illustrating an example of the arrangement of a stage, a magnet, and a line sensor in an inspection device according to a second modification of the third embodiment. FIG. [Figure 23] This is a graph illustrating the magnetic field components in the Z-axis direction on the inspection surface in an inspection device related to variant example 2 of embodiment 3, where the horizontal axis indicates the position indicated in degrees around the rotation axis and the vertical axis indicates the magnetic field components in the Z-axis direction on the inspection surface. [Figure 24] 13 is a graph illustrating the Kerr rotation angle on the inspection surface in the inspection device according to the second modification of the third embodiment, where 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. [Diagram 25] FIG. 13 is a plan view illustrating an example of the arrangement of a stage, a magnet, and a line sensor in an inspection device according to a third modification of the third embodiment. [Figure 26] This is a graph illustrating the magnetic field components in the Z-axis direction on the inspection surface in an inspection device related to variant 3 of embodiment 3, where the horizontal axis indicates the position indicated in degrees around the rotation axis and the vertical axis indicates the magnetic field components in the Z-axis direction on the inspection surface. [Figure 27] 11 is a graph illustrating the Kerr rotation angle on the inspection surface in the inspection device according to the third modification of the third embodiment, where 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. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] (Embodiment 1) An inspection device according to embodiment 1 will be described. Fig. 1 is a configuration diagram illustrating the inspection device according to embodiment 1. As shown in Fig. 1, the inspection device 1 includes devices W1-3 related to the transport of a wafer WF, members B1-B4 related to the base of the inspection device 1, a stage 10, a plurality of magnets 20, an optical system 30, a detector 40, an information processing unit 50, and a power supply and control unit 60. The inspection object is, for example, a wafer WF including a magnetoresistive memory element (MRAM element).

[0020] The devices W1 to W3 related to the transportation of the wafer WF include a wafer transport robot W1, a wafer pre-alignment device W2, and a wafer supply cassette W3. The wafer transport robot W1 transports the wafer WF to be inspected from the wafer supply cassette W3 into the inspection device 1. The wafer pre-alignment device W2 corrects the rotation angle and shift of the wafer WF. After being adjusted by the wafer pre-alignment device PWA, the wafer WF is transported to the stage 10 of the inspection device 1.

[0021] Components B1 to B4 related to the base of the inspection device 1 include a stone base B1, an active vibration isolation table (Isolator) B2, a wedge B3, and a dispersion plate B4. The stone base B1 serves as a base on which components such as the stage 10 and the optical system 30 are placed. The active vibration isolation table B2 suppresses vibrations of components on the stone base B1. The wedge B3 adjusts the level of the stone base B1 and the active vibration isolation table B2. The dispersion plate B4 distributes the load of the device relative to the floor. The information processing unit 50 processes information detected by the detector 40. The power supply and control unit 60 supplies power to the inspection device 1 and controls each part of the inspection device 1.

[0022] The stage 10 includes a moving part 11 and a main body part 12. The upper surface of the moving part 11 is called the stage surface 13. Thus, the stage 10 has the stage surface 13. The moving part 11 in the stage 10 may have a wafer chuck for holding the wafer WF. The wafer WF is fixed onto the stage surface 13 by the wafer chuck using vacuum or static electricity. The main body part 12 has an XYZθ drive axis having an actuator such as a linear motor, a ball screw, a VCM, or a piezoelectric actuator in order to move the moving part 11 holding the wafer WF.

[0023] The moving part 11 moves relative to the main body part 12 based on the XYZθ drive axis. An inspection plane W0 is introduced as a plane parallel to the stage plane 13. Then, the wafer WF (magnetoresistive memory element) fixed to the stage plane 13 moves within the inspection plane W0. The positions of the wafer WF and the magnetoresistive memory element may be measured by a laser interferometer 14. In this way, the stage 10 fixes the magnetoresistive memory element to the stage plane 13 and moves the magnetoresistive memory element within the inspection plane W0 parallel to the stage plane 13. For example, the stage 10 moves the magnetoresistive memory element linearly along one direction within the inspection plane W0. As shown in FIG. 1, in this embodiment, the configuration of the XYZθ stage is shown, but in the latter embodiment, a configuration using an rθ stage is also shown.

[0024] FIG. 2 is a diagram illustrating the magnet 20 of the inspection device 1 according to the first embodiment. As shown in FIG. 2, for convenience of explanation, an XYZ Cartesian coordinate system is introduced. The direction perpendicular to the inspection surface W0 is defined as the Z-axis direction, and two perpendicular directions in a plane parallel to the inspection surface W0 are defined as the X-axis direction and the Y-axis direction. As shown in FIG. 2, the multiple magnets 20 of the inspection device 1 include, for example, multiple electromagnets 21 and electromagnets 22. The multiple magnets 20 may include two electromagnets 21 and electromagnets 22 whose applied currents are controlled simultaneously, or may include two electromagnets 21 and electromagnets 22 whose applied currents are controlled independently. The multiple magnets 20 may also include permanent magnets.

[0025] Figure 3 is a graph illustrating the magnetic field components in the Z-axis direction of the magnetic lines on the inspection surface W0 in the inspection device 1 of embodiment 1, where the horizontal axis indicates the position in the X-axis direction on the inspection surface W0 and the vertical axis indicates the magnetic field components in the Z-axis direction of the magnetic lines on the inspection surface W0.

[0026] 2 and 3, the multiple magnets 20 generate a gradient magnetic field on the examination surface W0. The gradient magnetic field generates a gradient magnetic field in which the direction of the magnetic field component in the Z-axis direction perpendicular to the examination surface W0 changes from the +Z-axis direction to the -Z-axis direction depending on the position on the examination surface W0. Here, the -Z-axis direction is the opposite direction to the +Z-axis direction. In this way, the multiple magnets 20 generate a magnetic field that is constant over time but different depending on the location.

[0027] 1, the optical system 30 may include an optical microscope. The optical microscope forms an image of the surface of the wafer WF. The optical system 30 includes 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 a focus of the wafer WF, as well as several lenses P1 to P9 and several mirrors M1 to M4.

[0028] The light source 31 emits illumination light. The illumination light is, for example, laser light. The illumination light emitted from the light source 31 contains a predetermined wavelength band by passing through a filter 32. The illumination light that has passed through the filter 32 is converted by a polarizer 33 to contain linearly polarized light. The illumination light containing linearly polarized light is reflected by a mirror M2 and focused on the wafer WF by an objective lens 34. The mirror M2 is, for example, a non-polarizing beam splitter.

[0029] The objective lens 34 is for forming an image of a pattern on the wafer WF, and is generally non-magnetic. When the wafer WF includes a magnetoresistance memory element, the polarization angle of the linearly polarized light changes due to the magneto-optical Kerr effect. The light reflected by the wafer WF passes through the objective lens 34 and enters an analyzer 35. The analyzer 35 detects the change in the polarization angle of the linearly polarized light included in the reflected light. The analyzer 35 includes, for example, an analyzer. The reflected light transmitted through the analyzer 35 enters a detector 40 via a filter 36. The AF sensor 37 is a member for focusing the wafer WF surface. The AF sensor 37 uses a semiconductor laser light source with a wavelength longer or shorter than that of the illumination light and reflected light used in the optical system 30.

[0030] The detector 40 acquires a pattern of the wafer WF. The detector 40 may have a plurality of line sensors L1 and L2, and a review monitor 42. The plurality of line sensors L1 and L2 are collectively referred to as line sensors 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 review monitor 42 may include a CCD (Charge-Coupled Device) sensor. The CCD sensor may be used for review. The optical path between the line sensors L1 and L2 and the review monitor 42 is switched by inserting a mirror M3.

[0031] Fig. 4 is a flow chart illustrating a method for transporting a wafer WF to be inspected in the inspection apparatus 1 according to embodiment 1. As shown in step S11 in Fig. 4, first, the wafer WF is placed on the inspection apparatus 1. Specifically, the wafer transport robot W1 transports the wafer WF to be inspected from the wafer supply cassette W3 into the inspection apparatus 1.

[0032] Next, as shown in step S12, the pre-wafer alignment device W2 corrects the rotation angle and shift of the wafer WF. After the wafer WF is adjusted by the pre-wafer alignment device W2, it is transferred to the stage 10 of the inspection device 1. Next, as shown in step S13, the wafer WF is aligned on the stage 10. For example, the wafer WF is aligned using a laser interferometer 14. Next, as shown in step S14, the wafer WF on the stage 10 is moved to inspect the magnetoresistive memory element. In this way, the magnetoresistive memory element is moved within the gradient magnetic field.

[0033] Next, as shown in step S15, an image of the magneto-optical effect in the magneto-resistance memory element of the wafer WF is obtained by the detector 40. Specifically, the polarization angle due to the magneto-optical effect of the magneto-resistance memory element is measured. In this manner, the magneto-resistance memory element is inspected. Next, as shown in step S16, after the inspection, the wafer WF is removed from the stage 10.

[0034] FIG. 5 is a plan view illustrating a wafer WF according to the first embodiment. As shown in FIG. 5, the wafer WF includes a plurality of die DIEs. Only the solid film of the perpendicular magnetization film before the die DIEs are formed may be inspected. In FIG. 5, some symbols are omitted so as not to make the drawing complicated. The die DIE is, for example, a rectangle having short and long sides in the X-axis direction and the Y-axis direction. The plurality of die DIEs are arranged on the wafer WF so as to have spatial repeating periodicity in the X-axis direction and the Y-axis direction. The die DIE includes a plurality of magnetoresistive memory elements MRAM. The magnetoresistive memory elements MRAM have storage areas arranged in an array with repeating periodicity. The line sensor 41 acquires images in the forward direction while moving in the X-axis direction so as to cross the plurality of die DIEs. After acquiring one row of images along the X-axis direction, the line sensor 41 moves in the Y-axis direction and acquires one row of images along the X-axis direction from the reverse direction again.

[0035] 6 is a sequence diagram illustrating an inspection method of the die DIE included in the wafer WF according to the first embodiment, where the horizontal axis indicates time and the vertical axis indicates the electromagnet current, the inspection zone, the moving direction of the wafer WF, the die inspection period, and the LRC. As shown in FIG. 6, when inspecting all the die DIE of the wafer WF, the moving direction of the line sensor 41 is alternately repeated in the forward and reverse directions. Then, images are acquired without gaps, including several pixels for filtering and scan correction. Due to the inspection time, it is not necessary to inspect without gaps, and it is also possible to thin out the images in the Y direction for inspection.

[0036] 1, a laser beam linearly polarized by a polarizer 33 is irradiated onto a wafer WF, and the reflected light is made incident on a detector 40 through an analyzer 35 including an analyzer. The amount of light incident on the detector 40 by the analyzer 35 changes according to the polarization angle, so that the magnetization distribution is imaged. By changing the magnetic field applied to the magnetoresistive memory element MRAM, the magnetic characteristics of the magnetoresistive memory element MRAM in the wafer WF can be measured from the distribution of the polarization angle according to the magnetic field.

[0037] FIG. 7 is a diagram illustrating the magnetic characteristics of a magnetoresistive memory element MRAM, where the horizontal axis indicates the external magnetic field and the vertical axis indicates the Kerr rotation angle. As shown in FIG. 7, when the external magnetic field is increased from 0, the Kerr rotation angle 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. Next, when the external magnetic field is decreased from the saturated state, the Kerr rotation angle decreases. Then, even if the external magnetic field is reduced to 0, the Kerr rotation angle remains. When the external magnetic field is further reduced, the Kerr rotation angle reaches a certain value and saturates. Therefore, it does not change even if the external magnetic field is reduced. When the external magnetic field is increased from the saturated state, the Kerr rotation angle increases. When the external magnetic field is increased and when the external magnetic field is reduced, the path of the value of the Kerr rotation angle is different. In this way, the Kerr rotation angle forms a hysteresis curve that follows a different route when the external magnetic field is increased and when the external magnetic field is reduced.

[0038] FIG. 8 is a diagram illustrating the magnetic characteristics of the magnetoresistive memory element MRAM, where the horizontal axis indicates the external magnetic field and the vertical axis indicates the Kerr rotation angle. FIG. 8 also shows an image including the polarization state of the magnetoresistive memory element MRAM when the external magnetic field H is H1, H2, and H3. As shown in FIG. 8, an image captured when the external magnetic field is gradually increased shows brightness due to different Kerr rotation angles at the external magnetic field H=H1, H2, and H3. The Kerr rotation angle and the brightness detected by the detector 40 are correlated. Therefore, the coercive force (magnetic field of the image of H2 in the above example) and its variation of each magnetoresistive memory element MRAM can be obtained from the image obtained by the detector 40. When the size of the magnetoresistive memory element MRAM is smaller than the camera resolution or optical resolution, the average magnetic characteristics of the observation area are obtained.

[0039] In this embodiment, the inspection is performed by moving the magnetoresistive memory element MRAM in a gradient magnetic field. In contrast, in a method of changing the magnetic field by fixing the stage 10 and changing the current flowing through the electromagnet, it takes time to change the current. Also, for highly sensitive detection, it is necessary to extend the exposure time of the camera. In particular, when inspecting the entire surface of the wafer WF, it is necessary to repeat the measurement of moving each magnetoresistive memory element MRAM on the wafer WF to the inspection position and changing the current flowing through the electromagnet. Therefore, the increase in inspection time becomes a problem.

[0040] In this embodiment, the time required to change the current flowing through the electromagnet can be reduced, and the exposure time of the camera can be reduced by synchronizing the detector 40 with the movement of the magnetoresistive memory element MRAM.

[0041] In the inspection method of moving the magnetoresistive memory element MRAM in the gradient magnetic field, there are a case where one line sensor is used and a case where multiple line sensors are used. Here, before explaining the case where multiple line sensors are used in the present embodiment, a case where one line sensor is used in a comparative example will be explained. This will clarify the present embodiment.

[0042] 9 is an image diagram illustrating an area S1 on an inspection surface W0 detected by one line sensor L1 in an inspection device according to a comparative example. As shown in FIG. 9, for example, in the field of view of a review monitor 42, the line sensor L1 detects an area S1 extending in the Y-axis direction. By moving the magnetoresistive memory element MRAM in the X-axis direction, the magneto-optical effect of the magnetoresistive memory element MRAM, i.e., the change in brightness due to the Kerr rotation angle, is detected.

[0043] FIG. 10 is a graph illustrating the magnetic field component in the Z-axis direction on the inspection surface W0 in the inspection device according to the comparison, where the horizontal axis indicates the position in the X-axis direction on the inspection surface W0, and the vertical axis indicates the magnetic field component in the Z-axis direction on the inspection surface W0. FIG. 10 also shows an area S1 on the inspection surface W0 detected by the line sensor L1. FIG. 11 is a graph illustrating the Kerr rotation angle on the inspection surface W0 in the inspection device according to the comparative example, where 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. 11 also shows the luminance of multiple magnetoresistive memory elements MRAM.

[0044] 10 and 11, at time t=t0, the magnetoresistive memory element MRAM is located in an area where the magnetic field component in the Z-axis direction is 0. When the magnetoresistive memory element MRAM is moved in the X-axis direction, the external magnetic field received by the magnetoresistive memory element MRAM increases. This increases the Kerr rotation angle.

[0045] However, when the Kerr rotation angle reaches a certain value, it becomes saturated and does not change even if the external magnetic field is increased (time t=t1). In the comparative example, the line sensor L1 acquires the luminance according to the Kerr rotation angle of the multiple magnetoresistive memory elements MRAM aligned in the Y-axis direction at time t=t1. For example, if there is a defect in the multiple magnetoresistive memory elements MRAM aligned in the Y-axis direction, the defective magnetoresistive memory element MRAM shows a luminance different from that of the adjacent normal magnetoresistive memory element MRAM. In this case, the line sensor L1 detects the difference diff between the luminance of the defect and the luminance of the adjacent normal magnetoresistive memory element MRAM.

[0046] Next, a method for inspecting the magnetoresistive memory element MRAM of this embodiment will be described. In this embodiment, there are multiple line sensors L1 and L2. FIG. 12 is an image diagram illustrating areas S1 and S2 on the inspection surface W0 detected by the multiple line sensors L1 and L2 in the inspection device 1 according to the first embodiment. As shown in FIG. 12, the multiple line sensors L1 and L2 detect areas S1 and S2 extending in the Y-axis direction, respectively. The areas S1 and S2 have lengths d1 and d2 in the X-axis direction, and a length W in the Y-axis direction. The areas S1 and S2 are arranged side by side with a gap gap in the X-axis direction.

[0047] Fig. 13 is a graph illustrating the magnetic field component in the Z-axis direction on the inspection surface W0 in the inspection device 1 according to the first embodiment, where the horizontal axis indicates the position in the X-axis direction on the inspection surface W0, and the vertical axis indicates the magnetic field component in the Z-axis direction on the inspection surface W0. Fig. 13 also shows areas S1 and S2 on the inspection surface W0 detected by each line sensor. Fig. 14 is a graph illustrating the Kerr rotation angle on the inspection surface W0 in the inspection device 1 according to the first embodiment, where 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. 14 also shows the luminance of a plurality of magnetoresistive memory elements MRAM.

[0048] As shown in Figures 13 and 14, at time t = t0, the magnetoresistive memory element MRAM is located in a region where the magnetic field component in the Z-axis direction is 0. When the magnetoresistive memory element MRAM is moved in the X-axis direction, the external magnetic field that the magnetoresistive memory element MRAM receives increases. This increases the Kerr rotation angle. However, when the Kerr rotation angle reaches a certain value, it saturates and does not change even if the external magnetic field is increased (time t = t1). The line sensor L2 acquires the brightness according to the Kerr rotation angle of multiple magnetoresistive memory elements MRAM aligned in the Y-axis direction at time t = t1.

[0049] Furthermore, when the magnetoresistive memory element MRAM is moved in the X-axis direction, the external magnetic field received by the magnetoresistive memory element MRAM becomes smaller. This also reduces the Kerr rotation angle. The external magnetic field then becomes zero. When the magnetoresistive memory element MRAM is moved in the X-axis direction, the external magnetic field received by the magnetoresistive memory element MRAM is reversed. This reduces the Kerr rotation angle. When the magnetoresistive memory element MRAM is moved in the X-axis direction, the external magnetic field received by the magnetoresistive memory element MRAM in the reverse direction increases. This further reduces the Kerr rotation angle.

[0050] At time t=t2, when the external magnetic field in the opposite direction becomes larger, the Kerr rotation angle becomes smaller and the brightness also becomes smaller. The line sensor L1 acquires the brightness according to the Kerr rotation angle of the multiple magnetoresistive memory elements MRAM aligned in the Y-axis direction at time t=t2. Furthermore, when the magnetoresistive memory element MRAM is moved in the X-axis direction, the external magnetic field in the opposite direction that the magnetoresistive memory element MRAM receives becomes smaller. Then, the external magnetic field becomes zero.

[0051] As shown in FIG. 14, in this embodiment, the line sensor L2 acquires the luminance of the multiple magnetoresistive memory elements MRAM at time t=t1. Also, the line sensor L1 acquires the luminance of the multiple magnetoresistive memory elements MRAM at time t=t2. Thus, in this embodiment, the line sensor L2 detects the magneto-optical effect at the position of the magnetoresistive memory element MRAM at time t=t1 by moving the position of the magnetoresistive memory element MRAM in the gradient magnetic field. The line sensor L1 detects the magneto-optical effect at the position of the magnetoresistive memory element MRAM at time t=t2. Therefore, the multiple line sensors L2 and L1 respectively detect the magneto-optical effect due to the magnetic field component oriented in the +Z axis direction and the magneto-optical effect due to the magnetic field component oriented in the -Z axis direction.

[0052] At time t=t1, if a defect exists in the multiple magnetoresistive memory elements MRAM aligned in the Y-axis direction, the line sensor L2 detects the brightness of the defect. The defective magnetoresistive memory element MRAM exhibits a brightness different from that of the adjacent normal magnetoresistive memory element. Also, at time t=t2, if a defect exists in the multiple magnetoresistive memory elements MRAM aligned in the Y-axis direction, the line sensor L1 detects the brightness of the defect. The defective magnetoresistive memory element MRAM exhibits a brightness different from that of the adjacent normal magnetoresistive memory element.

[0053] The information processing unit 50 processes the magneto-optical effect detected by the multiple line sensors L1 and L2. Specifically, the information processing unit 50 inspects the magneto-optical memory 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 magneto-resistive memory element MRAM at time t=t1 detected by the line sensor L2 and the luminance of the defective magneto-resistive memory element MRAM at time t=t2 detected by the line sensor L1. In this way, the information processing unit 50 compares the luminance of the same magneto-resistive memory element MRAM at different times t1 and t2.

[0054] 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 the adjacent normal magnetoresistive memory element MRAM, or may detect the difference diff between the luminance of the defect detected by the line sensor L2 and the luminance of the adjacent normal magnetoresistive memory element MRAM. The information processing unit 50 may process the magnetoresistive effect detected by three or more line sensors, not limited to the two line sensors L1 and L2.

[0055] Fig. 15 is a graph illustrating the Kerr rotation angle in the inspection device 1 according to the first embodiment, where 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. As shown in Fig. 15, in the magnetoresistive memory element MRAM, the Kerr rotation angle shows hysteresis due to the external magnetic field. The luminance according to the Kerr rotation angle when the magnetic field component in the Z-axis direction is oriented toward the +Z axis is defined as Ms+. The luminance according to the Kerr rotation angle when the magnetic field component in the Z-axis direction is oriented toward the -Z axis is defined as Ms-. The luminance according to the Kerr rotation angle when the magnetic field component in the Z-axis direction is 0 without hysteresis is defined as M=0.

[0056] FIG. 16 is a graph illustrating the gray values ​​of the magnetoresistive memory element MRAM in the inspection device 1 according to the first embodiment, where the horizontal axis indicates the magnetoresistive memory element and the vertical axis indicates the gray value. As shown in FIG. 16, the gray value of the luminance differs depending on the Kerr rotation angle of the magnetoresistive memory element MRAM. There is a large difference between the gray value due to the luminance Ms+ and the gray value due to the luminance Ms-. Therefore, as in this embodiment, the detector 40 including the multiple line sensors L1 and L2 can detect a difference Diff in luminance that is larger than the difference diff in luminance detected by one line sensor.

[0057] Next, the effects of this embodiment will be described. The inspection device 1 of this embodiment has a gradient magnetic field. The gradient magnetic field changes the magnetic field component from the +Z axis direction to the -Z axis direction depending on the position of the inspection surface W0. The gradient magnetic field is constant over time and varies depending on the location. By moving within such a gradient magnetic field, the magnetic field applied to the magnetoresistive memory element MRAM is changed. Therefore, the distribution of the magnetic field generated by the magnet 20 such as an electromagnet may be constant as a gradient magnetic field. Therefore, it is not necessary to change the current flowing through the coil of the electromagnet during inspection. Therefore, 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.

[0058] In addition, the magnetization distribution of the magnetoresistive memory element MRAM is monitored as an image and integrated using a line sensor 41 such as a TDI camera. This allows for highly sensitive measurement, and does not require the long-term imaging required up until now. In this way, by using two or more line sensors 41 and a magnet 20 that generates a gradient magnetic field for the magnetoresistive effect element MRAM, the inspection time can be shortened and defect detection capability can be improved.

[0059] Furthermore, the inspection device 1 can change the shape of the magnetic field distribution to a vertical magnetic field distribution by independently switching the directions of currents in the multiple electromagnets, thereby measuring the hysteresis distribution.

[0060] (Embodiment 2) Next, an inspection device according to a second embodiment will be described. In the inspection device of this embodiment, a plate member including a magnetic material is embedded in the stage 10. FIG. 17 is a cross-sectional view illustrating the stage 10 and the magnet 20 in the inspection device according to the second embodiment. As shown in FIG. 17, the stage 10 in the inspection device 2 includes a plate member 15. The plate member 15 is plate-shaped and includes a magnetic material. The plate member 15 is, for example, an iron plate. Note that the plate member 15 is not limited to an iron plate as long as it includes a magnetic material. The plate member 15 is embedded inside the stage 10 and is not exposed to the stage surface 13.

[0061] When viewed from a direction perpendicular to the stage surface 13, the region surrounded by the outer edge of the plate member 15 includes the magnetoresistive memory element MRAM fixed to the stage surface 13. For example, when viewed from a direction perpendicular to the stage surface 13, the area of ​​the region surrounded by the outer edge of the plate member 15 is larger than the area of ​​the magnetoresistive memory element MRAM fixed to the stage surface 13.

[0062] When the wafer WF includes a plurality of magnetoresistive memory elements MRAM and the wafer WF is fixed to the stage surface 13, the region surrounded by the outer edge of the plate member 15 when viewed from a direction perpendicular to the stage surface 13 includes the wafer WF fixed to the stage surface 13. For example, when viewed from a direction perpendicular to the stage surface 13, 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 13. With this configuration, the gradient magnetic field can be stabilized. Other configurations and effects of the second embodiment are included in the description of the first embodiment.

[0063] (Embodiment 3) Next, an inspection device according to a third embodiment will be described. In this embodiment, the stage rotates around a rotation axis perpendicular to the stage surface. Thus, the stage rotates the magnetoresistive memory element MRAM around a rotation axis perpendicular to the inspection surface W0. FIG. 18 is a perspective view illustrating the stage and magnets in the inspection device according to the third embodiment. As shown in FIG. 18, the stage 110 in the inspection device 3 is, for example, disk-shaped. The stage 110 has a stage surface 113 and rotates around a rotation axis C perpendicular to the stage surface 113. The direction opposite to the clockwise rotation direction around the rotation axis C is defined as the +θ direction.

[0064] The two magnets 121 and 122 are disposed above the stage surface 113. The center position between the magnets 121 and 122 is fixed. However, the distance between the magnets 121 and 122 can be expanded or contracted. For example, when the center position between the magnets 121 and 122 is fixed on the rotation axis C, the magnets 121 and 122 can be expanded or contracted in the radial direction of the stage 110. Therefore, the two magnets 121 and 122 adjust the mutual distance based on the position of the magnetoresistive memory element MRAM to be inspected, to generate a gradient magnetic field. Note that the center position between the magnets 121 and 122 is not limited to being on the rotation axis C.

[0065] When the center of the wafer WF is positioned on the rotation axis C, the multiple line sensors 41 each measure the magnetic field characteristics due to the magnets 121 and 122. As the wafer WF rotates once, each line sensor 41 can measure the magnetic field characteristics due to the magnetic field (+H) oriented in the +Z axis direction and the magnetic field (-H) oriented in the -Z axis direction. The measurement region SR is annular about the rotation axis C on the inspection surface W0.

[0066] The distance from the center of the wafer WF to the magnet 121 (or magnet 122) is r. The tangential velocity v (linear speed) of the measurement region SR depends on the distance r from the center of the wafer WF. That is, at v=rω, the angular velocity ω is adjusted to match the scan speed of the line sensor 41 such as TDI. This allows the line sensor 41 to obtain an image of the magneto-optical effect. The application of the rotating stage 110 according to this embodiment has the advantages of saving turnaround time compared to an XY stage, and of not needing to control the accumulation direction of the line sensor 41 such as TDI with respect to the scan direction. Below, some modified examples of the third embodiment are shown.

[0067] (Variation 1) Fig. 19 is a plan view illustrating the arrangement of the stage 110, magnets 121 and 122, and line sensors L1 and L2 in an inspection device according to Modification 1 of the third embodiment. As shown in Fig. 19, in the inspection device 3a of this modification, the center position between the magnets 121 and 122 on the stage surface 113 is located between the rotation axis C and the edge of the stage surface 113 on the +X-axis direction side. The magnet 121 is disposed on the +Y-axis direction side of the center position, and the magnet 122 is disposed on the -Y-axis direction side of the center position. The gradient magnetic field is formed along the Y-axis direction.

[0068] The multiple line sensors L1 and L2 are disposed between the magnet 121 and the magnet 122. The multiple line sensors L1 and L2 extend in the X-axis direction. As the stage 110 rotates, the multiple line sensors L1 and L2 measure a circular measurement area SR whose width is the measurement width of the line sensor 41.

[0069] Fig. 20 is a graph illustrating the magnetic field component in the Z-axis direction on the inspection surface W0 in the inspection device 3a according to the first modification of the embodiment 3, where the horizontal axis indicates the position in the Y-axis direction on the inspection surface, and the vertical axis indicates the magnetic field component in the Z-axis direction on the inspection surface W0. Fig. 21 is a graph illustrating the Kerr rotation angle on the inspection surface W0 in the inspection device 3a according to the first modification of the embodiment 3, where 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.

[0070] As shown in Figures 20 and 21, at time t = t0, the magnetoresistive memory element MRAM is located in a region where the magnetic field component in the Z-axis direction is 0. When the magnetoresistive memory element MRAM is moved in the +θ direction, the external magnetic field received by the magnetoresistive memory element MRAM increases. This increases the Kerr rotation angle. However, when the Kerr rotation angle reaches a certain value, it saturates and does not change even if the external magnetic field is increased (time t = t1). The line sensor L2 acquires the brightness according to the Kerr rotation angle of multiple magnetoresistive memory elements MRAM arranged in the radial direction at time t = t1.

[0071] Furthermore, when the magnetoresistive memory element MRAM is moved in the +θ direction, the external magnetic field received by the magnetoresistive memory element MRAM becomes smaller. This reduces the Kerr rotation angle. The external magnetic field then becomes zero. When the magnetoresistive memory element MRAM is moved in the +θ direction, the external magnetic field received by the magnetoresistive memory element MRAM is reversed. This reduces the Kerr rotation angle. When the magnetoresistive memory element MRAM is moved in the +θ direction, the external magnetic field received by the magnetoresistive memory element MRAM in the reverse direction increases. This reduces the Kerr rotation angle even further.

[0072] At time t=t2, when the external magnetic field in the opposite direction increases, the Kerr rotation angle decreases. The line sensor L1 acquires the brightness according to the Kerr rotation angle of the multiple magnetoresistive memory elements MRAM aligned in the radial direction at time t=t2. Furthermore, when the magnetoresistive memory element MRAM is moved in the +θ direction, the external magnetic field in the opposite direction received by the magnetoresistive memory element MRAM decreases. Then, the external magnetic field becomes zero.

[0073] 20, in this embodiment, the line sensor L2 acquires the luminance of the multiple magnetoresistive memory elements MRAM at time t=t1. The line sensor L1 acquires the luminance of the multiple magnetoresistive memory elements MRAM at time t=t2. The information processing unit 50 detects the difference Diff between the luminance of the defective magnetoresistive memory element MRAM at time t=t1 and the luminance of the defective magnetoresistive memory element MRAM at time t=t2.

[0074] (Variation 2) Next, an inspection device according to Modification 2 of the third embodiment will be described. Fig. 22 is a plan view illustrating an arrangement of the stage 110, the magnets 121 and 122, and the line sensors L1 and L2 in the inspection device according to Modification 2 of the third embodiment. As shown in Fig. 22, in the inspection device 3b, the center position between the magnets 121 and 122 on the stage surface 113 is located on the rotation axis C. The magnet 121 is disposed on the -X axis direction side of the rotation axis C, and the magnet 122 is disposed on the +X axis direction side of the rotation axis C. The gradient magnetic field is formed along the X axis direction.

[0075] The multiple 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 multiple line sensors L1 and L2 extend in the Y axis direction. The magnet 121, the magnet 122, the line sensor L1, and the line sensor L2 are positioned equidistant from the rotation axis C. Therefore, the magnet 121, the line sensor L1, the magnet 122, and the line sensor L2 are arranged at equal intervals on a circumference centered on the rotation axis. As the stage 110 rotates, the multiple line sensors L1 and L2 measure a circular measurement area SR whose width is the measurement width of the line sensor 41.

[0076] Fig. 23 is a graph illustrating the magnetic field component in the Z-axis direction on the inspection surface W0 in the inspection device 3b according to the second modification of the third embodiment, where the horizontal axis indicates the position on the measurement region SR shown in angle around the rotation axis C, and the vertical axis indicates the magnetic field component in the Z-axis direction on the inspection surface W0. Fig. 24 is a graph illustrating the Kerr rotation angle on the inspection surface W0 in the inspection device 3b according to the second modification of the third embodiment, where 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.

[0077] As shown in Figures 23 and 24, at the position of θ=0 on the inspection surface W0, the magnetoresistive memory element MRAM is directly below the magnet 122. Therefore, the magnetoresistive memory element MRAM is located in an area where the magnetic field component oriented in the +Z axis direction is large. When the magnetoresistive memory element MRAM is moved in the +θ direction, the external magnetic field received by the magnetoresistive memory element MRAM becomes smaller. This also reduces the Kerr rotation angle. Then, at θ=π / 2, the external magnetic field becomes 0. The line sensor L1 acquires the brightness according to the Kerr rotation angle of multiple magnetoresistive memory elements MRAM arranged in the radial direction at θ=π / 2.

[0078] Furthermore, when the magnetoresistive memory element MRAM is moved in the θ direction, the reverse external magnetic field that the magnetoresistive memory element MRAM receives becomes larger. This reduces the Kerr rotation angle. At θ=π, the magnetoresistive memory element MRAM is directly under the magnet 121. Therefore, the magnetoresistive memory element MRAM is located in an area where the reverse magnetic field component is large. Furthermore, when the magnetoresistive memory element MRAM is moved in the +θ direction, the reverse magnetic field component that the magnetoresistive memory element MRAM receives becomes smaller. Then, at θ=3π / 2, the external magnetic field becomes 0. The line sensor L2 acquires the luminance according to the Kerr rotation angle of the multiple magnetoresistive memory elements MRAM arranged in the radial direction at θ=3π / 2. The information processing unit 50 detects the difference Diff between the luminance of the defective magnetoresistive memory element MRAM at θ=π / 2 and the luminance of the defective magnetoresistive memory element MRAM at θ=3π / 2.

[0079] (Variation 3) Next, an inspection device according to Modification 3 of the third embodiment will be described. Fig. 25 is a plan view illustrating an example of the arrangement of the stage 110, the magnets 121 and 122, and the line sensors L1 and L2 in the inspection device according to Modification 3 of the third embodiment. As shown in Fig. 25, in the inspection device 3c, the center position between the magnets 121 and 122 on the stage surface 113 is located on the rotation axis C. The magnet 121 is disposed on the -X axis direction side of the rotation axis C, and the magnet 122 is disposed on the +X axis direction side of the rotation axis C. The gradient magnetic field is formed along the X axis direction.

[0080] Line sensor L1 is disposed slightly on the +θ direction side of magnet 121, and line sensor L2 is disposed slightly on the +θ direction side of magnet 122. The multiple line sensors L1 and L2 extend in the X-axis direction. As stage 110 rotates, the multiple line sensors L1 and L2 measure a circular measurement area SR whose width is the measurement width of line sensor 41.

[0081] Fig. 26 is a graph illustrating the magnetic field component in the Z-axis direction on the inspection surface W0 in the inspection device 3c according to the third modification of the third embodiment, where the horizontal axis indicates the position on the measurement region SR shown in angle around the rotation axis C, and the vertical axis indicates the magnetic field component in the Z-axis direction on the inspection surface W0. Fig. 27 is a graph illustrating the Kerr rotation angle on the inspection surface W0 in the inspection device 3c according to the second modification of the third embodiment, where 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.

[0082] 26 and 27, at the position of θ=0 on the inspection surface W0, the magnetoresistive memory element MRAM is directly below the magnet 122. Therefore, the magnetoresistive memory element MRAM is located in an area where the magnetic field component in the +Z-axis direction is large. The line sensor L2 acquires the luminance according to the Kerr rotation angle of a plurality of magnetoresistive memory elements MRAM arranged in a radial direction slightly moved in the +θ direction from the magnet 122.

[0083] When the magnetoresistive memory element MRAM is further moved in the +θ direction, the external magnetic field received by the magnetoresistive memory element MRAM becomes smaller. This reduces the Kerr rotation angle. Then, at θ=π / 2, the external magnetic field becomes 0. When the magnetoresistive memory element MRAM is further moved in the +θ direction, the external magnetic field received by the magnetoresistive memory element MRAM in the opposite direction becomes larger. This reduces the Kerr rotation angle.

[0084] At θ=π, the magnetoresistive memory element MRAM is directly under the magnet 121. Therefore, the magnetoresistive memory element MRAM is located in an area where the magnetic field component in the opposite direction is large. The line sensor L1 acquires the luminance according to the Kerr rotation angle of the multiple magnetoresistive memory elements MRAM arranged in a radial direction slightly moved in the +θ direction from the magnet 121.

[0085] Furthermore, when the magnetoresistive memory element MRAM is moved in the +θ direction, the reverse magnetic field component received by the magnetoresistive memory element MRAM becomes smaller. Then, at θ=3π / 2, the external magnetic field becomes 0. The information processing unit 50 detects the difference Diff between the luminance of the defective magnetoresistive memory element MRAM at a position slightly in the +θ direction from θ=0 and the luminance of the defective magnetoresistive memory element MRAM at a position slightly in the +θ direction from θ=π. Other configurations and effects of the third embodiment and the first to third modifications are included in the description of the first and second embodiments.

[0086] The present invention is not limited to the above-described embodiments, and can be modified as appropriate without departing from the spirit and scope of the present invention. For example, combinations of the configurations of the first to third embodiments and the first to third modifications are also within the scope of the technical concept of the present invention. [Explanation of symbols]

[0087] 1, 2, 3, 3a, 3b, 3c inspection equipment Stages 10 and 110 11. Mobile section 12 Main body 13, 113 Stage surface 14 Laser interferometer 15 Plate members 20, 121, 122 Magnets 21, 22 Electromagnets 30 Optical system 31 Light source 32 Filters 33 Polarizer 34 Objective Lens 35 Analyzer 36 Filters 37 AF sensor 40 Detector 41 Line Sensor 42 Review Monitor 50 Information Processing Section 60 Power supply and control unit B1 stone surface plate B2 Active vibration isolation table B3 Wedge B4 Dispersion plate C Rotational Axis DIE MRAM Magnetoresistive memory element SR measurement area W0 Inspection surface W1 Wafer transport robot W2 Pre-wafer alignment equipment W3 Wafer supply cassette WF wafer

Claims

1. a stage having a stage surface, the stage fixing a magnetoresistive memory element to the stage surface and moving the magnetoresistive memory element within an inspection surface parallel to the stage surface; a plurality of magnets that generate gradient magnetic fields in which a direction of a magnetic field component perpendicular to the examination surface changes from a first direction to a second direction opposite to the first direction depending on a position of the examination surface; a plurality of line sensors including a first line sensor that detects a magneto-optical effect at a first position of the magneto-resistive memory element by moving the position of the magneto-resistive memory element within the gradient magnetic field, and a second line sensor that detects the magneto-optical effect at a second position different from the first position; an information processing unit that processes the magneto-optical effect detected by the plurality of line sensors; An inspection device equipped with

2. the plurality of line sensors include a line sensor that detects at least one of the magneto-optical effect caused by the magnetic field component in the first direction, the magneto-optical effect caused by the magnetic field component in the second direction, and the magneto-optical effect caused by a magnetic field component in a direction perpendicular to the inspection surface being zero; 2. The inspection device according to claim 1.

3. the information processing unit inspects the magnetoresistive memory element based on a difference between the magneto-optical effect detected by the first line sensor and the magneto-optical effect detected by the second line sensor.

3. The inspection device according to claim 1 or 2.

4. The stage has a plate member including a magnetic material embedded therein, When viewed from a direction perpendicular to the stage surface, a region surrounded by an outer edge of the plate member includes the magnetoresistive memory element fixed to the stage surface. The inspection device according to any one of claims 1 to 3.

5. A wafer is fixed to the stage surface, The wafer includes a plurality of the magnetoresistive memory elements or a perpendicular magnetization solid film before a memory element forming process, The stage has a plate member including a magnetic material embedded therein, When viewed from a direction perpendicular to the stage surface, a region surrounded by an outer edge of the magnetic body includes the wafer fixed to the stage surface. The inspection device according to any one of claims 1 to 3.

6. The plurality of magnets includes two electromagnets to which a current applied is independently controlled. The inspection device according to any one of claims 1 to 5.

7. the stage moves the magnetoresistive memory element or the perpendicular magnetization solid film before the memory element forming process linearly along one direction within the inspection surface; The inspection device according to any one of claims 1 to 6.

8. The stage rotates and moves the magnetoresistive memory element or the perpendicular magnetization solid film before the memory element forming process around a rotation axis perpendicular to the inspection surface. The inspection device according to any one of claims 1 to 6.

9. A wafer is fixed to the stage surface, The wafer includes a plurality of the magnetoresistive memory elements or a perpendicular magnetization solid film before a memory element forming process, the plurality of magnets generate the gradient magnetic field by adjusting the mutual spacing based on the position of the magnetoresistive memory element or the perpendicular magnetization solid film to be inspected; The inspection device according to any one of claims 1 to 8.

10. The first line sensor and the second line sensor include a TDI. The inspection device according to any one of claims 1 to 9.

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