Wafer inspection device and wafer inspection method using the same

Abstract

To provide a wafer inspection apparatus capable of forming a stripe pattern on a wafer surface by applying a horizontal magnetic field and thus determining uniformity of a magnetic property by evaluating uniformity of stripes, and to provide a method of inspecting a wafer using the same.SOLUTION: A wafer inspection apparatus disclosed herein comprises a horizontal magnetic field generation unit arranged proximate to a lateral surface of a wafer to form a magnetic field in such a way that lines of magnetic force extend in a horizontal direction, a vertical magnetic field generation unit arranged under the wafer to generate a magnetic field in such a way that lines of magnetic force extend in a direction vertical to the wafer, an image measurement unit arranged over the wafer to measure an image of the wafer, and a stage for moving the wafer in first and second directions.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a wafer inspection device, and more particularly to a wafer inspection device capable of determining the uniformity of magnetic properties by evaluating the uniformity of stripes on the wafer surface, and a wafer inspection method using the same. [Background technology]

[0002] Conventionally, methods for measuring the magnetic properties of wafers have been used to measure the magnetic moment of magnetic thin films deposited on wafers, such as by measuring the magnetic moment of magnetic materials using a vibrating sample magnetometer or a SQUID magnetometer, or by measuring the magnetic flux density as a function of distance using a compass.

[0003] Besides these methods, other techniques and devices have been proposed for measuring the magnetic properties of wafers by electrical measurement, optical measurement, or magnetic field change using an electromagnet.

[0004] Among these techniques, in the case of the technique for measuring the magnetic properties of a wafer by electrical measurement, the magnetic properties are inferred by observing the resistance change on the wafer surface using a contact tip, and the magnetic properties of the wafer are measured by generating a resistance change according to the magnetization direction.

[0005] However, such a method using resistance changes on the wafer surface requires the presence of a contact area, such as a contact mark, and heat damage occurs due to current concentration at the contact area, and there is a limit to the spatial resolution.

[0006] Furthermore, there is a problem that the measurement area of ​​the wafer is unclear and it takes a long time to scan the magnetic field.

[0007] On the other hand, in the case of optical measurement, a method has been proposed in which the magnetic properties of a wafer are measured by measuring the characteristics of light reflected from the wafer, such as reflectance and polarization direction.

[0008] However, such optical measurements are only capable of optically limited spatial resolution, take time to scan the entire wafer area to observe only one point, measurement results are obscured due to magnetic domain wall movement, and scanning the magnetic field takes time.

[0009] On the other hand, in the case of a method for measuring the magnetic properties of a wafer by changing the magnetic field of the wafer using an electromagnet, it takes time for the magnetic field to change, and the magnetic field change is suppressed by the inductance of the electromagnet, making high-speed measurement difficult.

[0010] Therefore, there was a need for a technology that could solve the problems of time-consuming scanning of the entire wafer area, ambiguous measurement results, and limited spatial resolution. Summary of the Invention [Problem to be solved by the invention]

[0011] The object of the present invention is to provide a wafer inspection device that can apply a horizontal magnetic field to the wafer surface to form a stripe pattern, evaluate the uniformity of the stripes, and determine the uniformity of magnetic properties, as well as a wafer inspection method using the same. [Means for solving the problem]

[0012] To achieve the above object, a wafer inspection apparatus according to an embodiment of the present invention is broadly divided into an image measurement unit, a magnetic field generation unit, and a wafer movement stage.

[0013] The magnetic field generating unit includes a horizontal magnetic field generating unit for applying a magnetic field in a direction parallel to the surface of the wafer.

[0014] In order to accurately align the horizontal magnetic field generator with the wafer surface, a stage capable of adjusting the angle of the wafer may be provided to adjust the angle between the wafer and the horizontal magnetic field, or a vertical magnetic field generator may also be provided.

[0015] This makes it possible to cancel out the vertical magnetic field generated by the shift in the horizontal magnetic field.

[0016] Furthermore, the vertical magnetic field generating unit can generate a magnetic field that cancels out the vertical magnetic field generated by the deviation of the horizontal magnetic field.

[0017] The horizontal magnetic field generating units may be disposed adjacent to and corresponding to both sides of the wafer to uniformly generate a magnetic field within the imaging region.

[0018] If the imaging area is sufficiently small, the horizontal magnetic field generating unit can be disposed on only one side instead of both sides.

[0019] A tilting stage may further be included for adjusting the angle of the sample in order to precisely align the horizontal magnetic field with the sample plane.

[0020] Any method may be used as long as imaging is possible, and either visible light or an electron beam may be used as the light source.

[0021] A wafer inspection method according to one embodiment of the present invention may include a horizontal magnetic field generating unit arranged close to a side of a wafer to form a magnetic field such that magnetic field lines travel horizontally, a vertical magnetic field generating unit arranged below the wafer to generate a magnetic field that cancels out a vertical magnetic field generated by a deviation of the horizontal magnetic field, an image measuring unit arranged above the wafer to measure an image of the wafer, and a wafer moving stage that moves the wafer back and forth and left and right.

[0022] According to the present invention, the horizontal magnetic field generators may be disposed adjacent to one side of the wafer or adjacent to both sides of the wafer and corresponding to each other.

[0023] According to the present invention, the horizontal magnetic field generating unit may include a horizontal coil support base and a coil wound around the horizontal coil support base.

[0024] According to the present invention, the vertical magnetic field generating unit may include a vertical coil support disposed below the wafer in a vertical direction of the wafer, and a vertical coil wound around the vertical coil support.

[0025] According to the present invention, the image measurement unit may include a microscope main body and a light source irradiation unit.

[0026] According to the present invention, the wafer movement stage may include a support on which the wafer and the vertical magnetic field generating unit are placed, a plurality of first rotational movement bars that move the support back and forth in a vertical direction on a surface, a plurality of second rotational movement bars that move the support from side to side in a horizontal direction perpendicular to the vertical direction, and a first support table and a second support table on which the first rotational movement bars and the second rotational movement bars are placed.

[0027] According to the present invention, the wafer moving stage may have any structure as long as it is capable of horizontal movement.

[0028] According to the present invention, in order to move the wafer movement stage horizontally, the first rotary movement bar and the second rotary movement bar may be configured with rails including bearings, or may be configured with an air bearing structure that operates by floating on air.

[0029] According to the present invention, the pedestal may include an upper pedestal on which the wafer is placed, a lower pedestal on which the vertical magnetic field generating unit is placed, and a plurality of vertical support pedestals that fix and support the edges of the upper pedestal and the lower pedestal.

[0030] According to the present invention, the vertical magnetic field generator can apply a magnetic field that can change the magnetization state of the wafer from up to down or from down to up.

[0031] According to the present invention, the vertical magnetic field generating unit is disposed below the wafer and is capable of generating a magnetic field that cancels out the vertical magnetic field generated by the deviation of the horizontal magnetic field.

[0032] A wafer inspection method according to another embodiment of the present invention may include a horizontal magnetic field generating unit that generates a magnetic field on the wafer so that magnetic lines of force move horizontally, a vertical magnetic field generating unit that generates a magnetic field on the wafer that cancels out a vertical magnetic field generated by a deviation of the horizontal magnetic field, and an image measuring unit that measures an image of the wafer.

[0033] According to the present invention, the horizontal magnetic field generators may be disposed adjacent to one side of the wafer or adjacent to both sides of the wafer so as to correspond to each other.

[0034] According to the present invention, the horizontal magnetic field generating unit may include a horizontal coil support base and a coil wound around the horizontal coil support base.

[0035] According to the present invention, the vertical magnetic field generating unit may include a vertical coil support disposed below the wafer in a vertical direction of the wafer, and a vertical coil wound around the vertical coil support.

[0036] According to the present invention, the image measurement unit may include a microscope main body and a light source irradiation unit.

[0037] According to the present invention, the apparatus may further include a wafer moving stage for moving the wafer back and forth and left and right.

[0038] According to the present invention, the wafer movement stage may include a support on which the wafer and the vertical magnetic field generating unit are placed, a plurality of first rotational movement bars that move the support back and forth in the vertical direction on the surface, a plurality of second rotational movement bars that move the support from side to side in the horizontal direction, and a first support table and a second support table on which the first rotational movement bars and the second rotational movement bars are placed.

[0039] According to the present invention, the pedestal may include an upper pedestal on which the wafer is placed, a lower pedestal on which the vertical magnetic field generating unit is placed, and a plurality of vertical support pedestals that fix and support edges of the upper pedestal and the lower pedestal.

[0040] According to another embodiment of the present invention, a wafer inspection method may include the steps of forming a magnetic thin film on a wafer, applying a horizontal magnetic field to the wafer to form a stripe pattern, and determining the uniformity of the wafer by determining the defect positions of the stripe throughout the entire area of ​​the wafer.

[0041] According to a wafer inspection method according to still another embodiment of the present invention, the step of determining the defect position of the stripe may include the step of inspecting the defect type of the wafer by determining the non-uniformity state of the width of the stripe, the direction of the stripe, or the ratio of the stripe. [Effects of the Invention]

[0042] The wafer inspection device of the present invention applies a horizontal magnetic field to a wafer to form stripes on the wafer, thereby identifying the location of defects in the stripes across the entire wafer, thereby enabling evaluation of the uniformity of the wafer and effectively measuring the uniformity of magnetic properties.

[0043] Furthermore, the wafer inspection apparatus according to the present invention is capable of moving the wafer position using a wafer moving stage so that the entire area of ​​the wafer can be imaged.

[0044] According to the embodiments of the present invention, the effects are not limited to those described above, and other effects not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the following description. [Brief explanation of the drawings]

[0045] [Figure 1] 1 is a perspective view showing a wafer inspection device according to an embodiment of the present invention; [Figure 2] FIG. 2 is a cross-sectional view of the wafer inspection device taken along line II-II′ in FIG. [Figure 3] FIG. 2 is a perspective view showing an image measurement unit in the wafer inspection device according to the embodiment of the present invention. [Figure 4A] 1 is a diagram showing a wafer surface being observed by an image measurement unit in a wafer inspection device according to an embodiment of the present invention. [Figure 4B] 1 is a diagram showing a wafer surface being observed by an image measurement unit in a wafer inspection device according to an embodiment of the present invention. [Figure 4C] 1 is a diagram showing a wafer surface being observed by an image measurement unit in a wafer inspection device according to an embodiment of the present invention. [Figure 5] 1 is a perspective view showing horizontal magnetic field generating units arranged on both sides of a wafer in a wafer inspection device according to an embodiment of the present invention. FIG. [Figure 6] FIG. 2 is a perspective view showing a vertical magnetic field generating unit disposed below a wafer in a wafer inspection device according to an embodiment of the present invention. [Figure 7] 1 is a perspective view showing a wafer moving stage that allows a wafer to move back and forth and left and right in a wafer inspection device according to an embodiment of the present invention. [Figure 8] 4 is a flowchart illustrating a process of measuring the uniformity of magnetic properties of a wafer using a wafer inspection apparatus according to an embodiment of the present invention. [Figure 9] 2 is a diagram illustrating a state in which a magnetic thin film and a fine pattern are formed on a wafer to be measured using a wafer inspection apparatus according to an embodiment of the present invention; [Figure 10A] 1 is a diagram showing a uniform distribution of physical properties of stripes on a wafer surface measured using a wafer inspection device according to an embodiment of the present invention. [Figure 10B] 10A and 10B are diagrams showing defects in the distribution of physical properties of stripes on a wafer surface measured using a wafer inspection device according to an embodiment of the present invention. [Figure 11A] 1 is a schematic perspective view showing a state in which a horizontal magnetic field is applied parallel to the surface of a wafer using a wafer inspection device according to an embodiment of the present invention. FIG. [Figure 11B] 10A and 10B are diagrams illustrating stripes on the wafer surface according to the strength of a horizontal magnetic field applied to the wafer surface; [Figure 12A] 10 is a diagram showing a schematic view of a stripe defect shape of a wafer measured when a horizontal magnetic field is applied parallel to the surface of the wafer using a wafer inspection apparatus according to an embodiment of the present invention, showing an uneven state of stripe width. [Figure 12B] 10 is a diagram showing a schematic view of the non-uniform state in the stripe direction among stripe defect shapes of a wafer measured when a horizontal magnetic field is applied parallel to the surface of the wafer using a wafer inspection apparatus according to an embodiment of the present invention. FIG. [Figure 12C] 10 is a diagram showing a schematic view of the non-uniformity of the proportion of stripes among stripe defect forms of a wafer measured when a horizontal magnetic field is applied parallel to the surface of the wafer using a wafer inspection apparatus according to an embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0046] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0047] However, the technical concept of the present invention is not limited to the described embodiments, but can be embodied in various different forms, and one or more of the components between the embodiments can be selectively combined and substituted within the scope of the technical concept of the present invention.

[0048] Furthermore, unless otherwise clearly defined and described, terms (including technical and scientific terms) used in the embodiments of the present invention may be interpreted as meanings that are commonly understood by a person of ordinary skill in the art to which the present invention belongs, and commonly used terms, such as dictionary-defined terms, may be interpreted in light of the contextual meaning of the relevant art.

[0049] Furthermore, the terms used in the embodiments of the present invention are intended to describe the embodiments and are not intended to limit the present invention.

[0050] In this specification, the singular can also include the plural unless otherwise stated in the phrase, and when it is stated as "A and (and) at least one (or more) of B and C," it can include one or more of all possible combinations of A, B, and C.

[0051] Furthermore, terms such as first, second, A, B, (a), (b), etc. may be used to describe components of embodiments of the present invention.

[0052] Such terms are used merely to distinguish a component from other components, and are not intended to limit the nature, order, or procedure of the component.

[0053] Furthermore, when a component is described as being "coupled," "coupled," or "connected" to another component, it can include not only the case where the component is directly coupled, coupled, or connected to the other component, but also the case where the component is "coupled," "coupled," or "connected" between the component and the other component or via another component.

[0054] Furthermore, when it is stated that something is formed or disposed "above or below" a component, "above or below" includes not only the case where two components are in direct contact with each other, but also the case where one or more other components are formed or disposed between the two components. Furthermore, when it is expressed as "above or below," it can mean not only the upper direction but also the lower direction based on one component.

[0055] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Regardless of the reference numerals, the same or corresponding components will be denoted by the same reference numerals, and redundant description thereof will be omitted.

[0056] FIG. 1 is a perspective view showing a wafer inspection device according to an embodiment of the present invention.

[0057] FIG. 2 is a cross-sectional view of the wafer inspection device taken along line II-II' in FIG.

[0058] 1 and 2, a wafer inspection apparatus 100 according to an embodiment of the present invention may include an image measurement unit 200, a magnetic field generation unit (not shown), and a wafer movement stage 500.

[0059] The magnetic field generating unit includes a horizontal magnetic field generating unit 300 for applying a magnetic field in a direction parallel to the side surface of the wafer 110 .

[0060] In order to accurately align the horizontal magnetic field generating unit 300 with the surface of the wafer 110, a tilting stage capable of adjusting the angle of the wafer 110 may be provided to adjust the angle between the wafer 110 and the horizontal magnetic field, and a vertical magnetic field generating unit 400 may also be provided.

[0061] This makes it possible to cancel out the vertical magnetic field generated by the shift in the horizontal magnetic field.

[0062] Furthermore, the vertical magnetic field generating unit 400 can generate a magnetic field that cancels out the vertical magnetic field generated by the deviation of the horizontal magnetic field.

[0063] The horizontal magnetic field generating units 300 may be arranged on both sides of the wafer 110 in correspondence with each other in order to make the magnetic field uniform within the imaging region, but are not limited thereto.

[0064] In particular, if the imaging area is sufficiently small, the horizontal magnetic field generating unit 300 can be disposed on only one side of the wafer 110 instead of both sides of the wafer 110 .

[0065] A tilting stage may further be included for adjusting the angle of the sample in order to precisely align the horizontal magnetic field with the sample plane.

[0066] Any method may be used as long as imaging is possible, and either visible light or an electron beam may be used as the light source.

[0067] The apparatus may include an image measuring unit 200 arranged at a certain distance above the wafer 110 to measure an image of the wafer 110, a horizontal magnetic field generating unit 300 arranged corresponding to one side or both sides of the wafer 110 on which the magnetic thin film is formed to form a magnetic field so that magnetic lines of force move horizontally, a vertical magnetic field generating unit 400 arranged below the wafer 110 to generate a magnetic field that cancels out a vertical magnetic field generated by a deviation of the horizontal magnetic field, and a wafer moving stage 500 that moves the wafer 110 back and forth and left and right.

[0068] FIG. 3 is a perspective view showing an image measurement unit in a wafer inspection device according to an embodiment of the present invention.

[0069] 4A to 4C are diagrams showing the wafer surface being observed by the image measurement unit in the wafer inspection device according to the embodiment of the present invention.

[0070] Referring to FIG. 3, the image measurement unit 200 may include a microscope main body 210 that generates a magneto-optical effect and a light source irradiation unit 220.

[0071] The magneto-optical effect occurs when a sample and light come into contact with each other, resulting in reflection, refraction, transmission, absorption, etc. Light that generates the magneto-optical effect can be observed through a microscope.

[0072] The image measurement unit 200 is disposed above the wafer 110 at a certain distance, and irradiates the surface of the wafer 110 with a light source 230 via a light source irradiation unit 220 of the microscope main body 210, acquires an image using the transmitted light, and can grasp the magnetic state or magnetization state of the material on the surface of the wafer 110 using the diffracted light. That is, light is reflected by the sample surface on the surface of the wafer 110, and the magnetization state of the wafer surface can be grasped by observing the reflected light.

[0073] The light source 230 may be an electron beam, a visible light beam, or the like, but is not limited to the visible light beam.

[0074] It is believed that imaging light or image light is more suitable for the light source 230 than an "electron beam."

[0075] The magneto-optical effect, or surface magneto-optical effect, is a type of magneto-optical effect, which refers to the change in light reflected from a magnetized surface. Instruments such as microscopes are used to investigate the magnetization structure of materials.

[0076] The magneto-optical effect relates to light reflecting off a magnetized surface, which can change both its polarization and its reflected intensity. The magneto-optical effect can be seen as analogous to the Faraday effect, which describes the change in light transmission through magnetic materials.

[0077] 4A to 4C, the image measuring unit 200 irradiates a light source onto the surface of the wafer 110 to observe the up magnetized region 110a and the down magnetized region 110b on the surface of the wafer 110.

[0078] Referring to FIG. 4A, the surface of the wafer 110 can show a uniform state with an up magnetized region 110a.

[0079] Referring to FIG. 4B, the surface of the wafer 110 may exhibit a uniform state with a down magnetized region 110b.

[0080] Referring to FIG. 4C, the surface of the wafer 110 is divided into an up magnetized region 110a and a down magnetized region 110b.

[0081] FIG. 5 is a perspective view showing horizontal magnetic field generating units arranged on both sides of a wafer in a wafer inspection device according to an embodiment of the present invention.

[0082] Referring to FIG. 5, the horizontal magnetic field generating unit 300 may include a horizontal magnetic body 310 and a first coil 320 wound around the outer surface of the horizontal magnetic body 310 .

[0083] A typical electromagnet may be configured with many coils wound around an iron core. The horizontal magnetic body 310 may be any type of device that can generate a magnetic field.

[0084] An electromagnet consisting of only a coil is also possible, and a method is also possible in which the strength of the magnetic field is changed by adjusting the distance from a permanent magnet.

[0085] The horizontal magnetic field generators 300 may be arranged adjacent to each other on both sides of the wafer 110 at regular intervals.

[0086] The horizontal magnetic body 310 guides the magnetic field lines toward the wafer 110. That is, the horizontal magnetic body 310 guides the magnetic field lines toward both sides of the wafer 110 on which the magnetic thin film is formed, in a direction parallel to the wafer. The horizontal magnetic body 310 may be a magnet or an electromagnet.

[0087] In addition, it is preferable that the first coil 320 is wound around at least a portion of the horizontal magnetic body 310 so that when electricity is supplied from the outside, magnetic lines of force are induced from the horizontal magnetic body 310 to form a magnetic field.

[0088] In order to measure magnetic properties such as magnetic moment and effective saturation magnetization of the wafer 110 on which the magnetic thin film is formed, a magnetic field is applied to a measurement area of ​​the wafer 110.

[0089] The magnetic field can be applied so that the direction of the magnetic field lines is parallel to the surface of the wafer 110. Therefore, the horizontal magnetic field generator 300 can generate a magnetic field that is precisely aligned with the surface of the wafer 110.

[0090] It is preferable that the strength of the magnetic field from the horizontal magnetic field generating unit 300 is maintained at a strength that induces the generation of stripes. In particular, it is preferable to apply a magnetic field that can counteract the tendency to maintain perpendicular magnetism.

[0091] The strength of the magnetic field must be approximately the same as the magnitude of the perpendicular anisotropic magnetic field.

[0092] FIG. 6 is a perspective view showing a vertical magnetic field generating unit disposed below a wafer in a wafer inspection device according to an embodiment of the present invention.

[0093] Referring to FIG. 6, the vertical magnetic field generating unit 400 may include a vertical magnetic body 410 and a second coil 420 wound around the outer surface of the vertical magnetic body 410 .

[0094] The vertical magnetic field generating unit 400 may be disposed below the wafer 110 and spaced apart from the wafer 110 at a predetermined distance.

[0095] Also, the vertical magnetic field generating unit 400 may be disposed at a predetermined distance from the wafer moving stage 500 .

[0096] The perpendicular magnetic body 410 guides the magnetic lines of force toward the wafer 110. That is, the perpendicular magnetic body 410 guides the magnetic lines of force in a direction perpendicular to the wafer 110 on which the magnetic thin film is formed. The perpendicular magnetic body 410 can be a magnet or an electromagnet.

[0097] In addition, the second coil 420 is preferably wound around at least a portion of the vertical magnetic body 410 so that when electricity is supplied from the outside, magnetic lines of force are induced from the vertical magnetic body 410 to form a magnetic field.

[0098] In order to measure magnetic properties such as magnetic moment and effective saturation magnetization of the wafer 110 on which the magnetic thin film is formed, a magnetic field is applied to a measurement area of ​​the wafer 110.

[0099] Here, a magnetic field can be applied so that the magnetic lines of force pass in a direction perpendicular to the surface of the wafer 110 .

[0100] The magnetic field strength is preferably strong enough to change the magnetization state of the wafer 110 from up to down or from down to up. In particular, the magnetic field strength must be strong enough to reverse the magnetization, and the tilt of the horizontal magnetic field may be corrected.

[0101] In particular, the vertical magnetic field generator 400 is disposed below the wafer 110 and can generate a magnetic field that cancels the vertical magnetic field generated due to the deviation of the horizontal magnetic field.

[0102] FIG. 7 is a perspective view showing a wafer moving stage that allows a wafer to move back and forth and left and right in a wafer inspection device according to an embodiment of the present invention.

[0103] Referring to FIG. 7, the wafer moving stage 500 includes a receiving stage 550 on which the wafer 110 and the vertical magnetic field generating unit 400 are placed, a plurality of first rotational movement bars 540 that move the receiving stage 550 back and forth in a first direction, and a plurality of second rotational movement bars 520 that move the receiving stage 550 back and forth in a second direction perpendicular to the first direction.

[0104] The wafer moving stage 500 only needs to be able to move in the front-to-back and left-to-right directions of the wafer moving stage 500, that is, horizontally in the front-to-back vertical direction and the left-to-right horizontal direction on the surface of the wafer moving stage 500.

[0105] The wafer moving stage 500 may have a variety of structural configurations and operating methods.

[0106] The wafer translation stage 500 may also include an additional tilting stage for use in aligning the horizontal magnetic field.

[0107] The pedestal 550 may include an upper pedestal 560 on which the wafer 110 is placed, a lower pedestal 570 on which the vertical magnetic field generating unit 400 is placed, and a plurality of vertical support pedestals 580 that fix and support edges of the upper pedestal 560 and the lower pedestal 570.

[0108] The plurality of first rotating and moving bars 540 are arranged at regular intervals in a first direction, for example, a vertical direction, below the lower receiving base 570, and are rotated and moved so that the receiving base 550 can move back and forth in the vertical direction on the surface. A first support base 530 on which the plurality of first rotating and moving bars 540 are arranged may be provided below the plurality of first rotating and moving bars 540.

[0109] In addition, the plurality of second rotating and moving bars 520 may be arranged at regular intervals in a horizontal direction, i.e., a second direction perpendicular to the vertical direction, below the first support stand 530, and may be rotated to move the first support stand 530 left and right in the horizontal direction. A second support stand 510 on which the plurality of second rotating and moving bars 520 are arranged may be provided below the plurality of second rotating and moving bars 520.

[0110] The plurality of first rotational movement bars 540 and second rotational movement bars 520 are in contact with the lower surfaces of the lower receiving stand 570 and the first support stand 530, respectively, and can rotate in a first direction or a second direction to move forward or backward, or move left or right to change the position of the wafer 110.

[0111] Therefore, by using the plurality of first rotational movement bars 540 and second rotational movement bars 520, the position of the wafer 110 can be moved forward, backward, left and right so that an image of the entire area of ​​the wafer 110 can be measured.

[0112] In addition, in the case of an embodiment of the present invention, a wafer moving method and a wafer fixed method can be used, and in the case of the wafer fixed method, the image measurement unit 200, the horizontal magnetic field generating unit 300, and the vertical magnetic field generating unit 400 can be moved to measure the entire area of ​​the wafer 110.

[0113] FIG. 8 is a flowchart illustrating a process for measuring the uniformity of magnetic properties of a wafer using a wafer inspection apparatus according to an embodiment of the present invention.

[0114] Referring to FIG. 8, first, a magnetic thin film (120 in FIG. 9) is deposited on the surface of a wafer (110 in FIG. 1) (S110).

[0115] Thereafter, the uniformity of the magnetic properties of the deposited magnetic thin film can be inspected using a wafer inspection device before the magnetic thin film is patterned.

[0116] Thereafter, a horizontal magnetic field is applied to the magnetic thin film 120 formed on the surface of the wafer 110 using a wafer inspection device (100 in FIG. 1) (S120).

[0117] Next, while applying a horizontal magnetic field, a light source is irradiated onto a selected area of ​​the wafer 110 by the image measurement unit (200 in FIG. 1), forming a stripe shape of the magnetic thin film 120 formed on the surface of the wafer 110 (S130).

[0118] At this time, when a horizontal magnetic field is applied to the wafer 110 on which the magnetic material is deposited, a stripe pattern is formed.

[0119] The imaging process simply observes this stripe pattern, without changing it.

[0120] Thereafter, the uniformity of the stripes in the area of ​​the wafer 110 inspected by the image measurement unit 200 is evaluated (S140).

[0121] Next, the uniformity of the magnetic properties of the magnetic thin film on the wafer 110 is determined (S150).

[0122] FIG. 9 is a diagram schematically illustrating a state in which a magnetic thin film and a fine pattern are formed on a wafer to be measured using a wafer inspection apparatus according to an embodiment of the present invention.

[0123] Referring to FIG. 9, a magnetic thin film 120 is deposited on a silicon wafer 110 and then finely patterned to form a magnetic thin film pattern 120a.

[0124] At this time, the uniformity of the magnetic thin film is measured before the magnetic thin film 120 is patterned.

[0125] Before finely patterning the magnetic thin film 120 formed on the silicon wafer 110, the uniformity, magnetization amount, and perpendicular anisotropy of the magnetic thin film 120 formed on the surface of the wafer 110 can be confirmed by detecting defect positions in the magnetic thin film 120 using a wafer inspection device (see 100 in FIG. 1) according to an embodiment of the present invention.

[0126] 10A and 10B are diagrams showing uniform physical property distribution in stripes on a wafer surface measured using a wafer inspection apparatus according to an embodiment of the present invention, and defects in the physical property distribution in stripes on a wafer surface measured using a wafer inspection apparatus according to an embodiment of the present invention.

[0127] Referring to FIG. 10A, a certain stripe pattern is observed on the magnetic thin film 120 formed on the surface of the wafer 110, indicating a uniform distribution of physical properties.

[0128] Referring to FIG. 10B, it can be seen that a non-uniform stripe defect D is observed along with a certain stripe pattern in the magnetic thin film 120 formed on the surface of the wafer 110, indicating a defect in the distribution of physical properties.

[0129] 11A is a schematic perspective view showing a state in which a horizontal magnetic field is applied parallel to the surface of a wafer using a wafer inspection device according to an embodiment of the present invention, and FIG. 11B is a schematic view showing stripes on the wafer surface depending on the strength of the horizontal magnetic field applied to the wafer surface.

[0130] Referring to FIG. 11A, a strong horizontal magnetic field is applied parallel to the magnetic thin film 120 formed on the surface of the wafer 110 from the horizontal magnetic field generating unit (300 in FIG. 1), thereby forming a stripe shape on the magnetic thin film 120 of the wafer 110.

[0131] 11B, it can be seen that the stripe pattern changes depending on the strength of the horizontal magnetic field. In particular, as the horizontal magnetic field increases, a uniform stripe pattern is formed in the uniform down region and the uniform up region.

[0132] In the case of the uniform down and uniform up, the horizontal magnetic field is smallest at zero (0), and the more dense the stripe structure becomes visible, the larger the horizontal magnetic field can become.

[0133] FIG. 12A is a diagram showing a schematic diagram of the non-uniformity of stripe width among the stripe defect forms of a wafer measured when a horizontal magnetic field is applied parallel to the surface of the wafer using a wafer inspection apparatus according to an embodiment of the present invention.

[0134] Figure 12B is a diagram showing a schematic diagram of the non-uniform state in the stripe direction among the stripe defect morphologies of a wafer measured when a horizontal magnetic field is applied parallel to the surface of the wafer using a wafer inspection apparatus according to an embodiment of the present invention.

[0135] Figure 12C is a diagram showing a schematic diagram of the non-uniformity of the proportion of stripes among the stripe defect forms of a wafer measured when a horizontal magnetic field is applied parallel to the surface of the wafer using a wafer inspection apparatus according to an embodiment of the present invention.

[0136] Referring to FIG. 12A, among the expected stripe defect forms, a defect D1 with an uneven stripe width may appear in one region.

[0137] In particular, in the case of the non-uniform defect D1, it is confirmed that the width of the non-uniform stripe pattern is formed to be smaller or larger than the width of the uniform stripe pattern.

[0138] Referring to FIG. 12B, among the expected stripe defect forms, a non-uniform defect D2 in the stripe direction may appear in one region.

[0139] In particular, in the case of non-uniform defect D2, it is confirmed that the direction of the non-uniform stripe pattern is formed at a certain angle different from the direction of the uniform stripe pattern, or is formed in a direction perpendicular to the direction of the uniform stripe pattern.

[0140] Referring to FIG. 12C, among the expected stripe defect forms, a defect D3 having an uneven proportion of stripes may appear in one region.

[0141] In particular, in the case of the non-uniform defect D3, it is confirmed that the proportion of non-uniform stripe patterns is larger or smaller than the proportion of uniform stripe patterns.

[0142] As described above, the wafer inspection device of the present invention applies a horizontal magnetic field to a wafer to form stripes on the wafer, thereby determining the location of defects in the stripes across the entire wafer, thereby evaluating the uniformity of the wafer and effectively measuring the uniformity of magnetic properties.

[0143] Furthermore, the wafer inspection apparatus according to the present invention is capable of moving the wafer position using a wafer moving stage so that the entire area of ​​the wafer can be imaged.

[0144] Although the present invention has been described above with reference to preferred embodiments, those skilled in the art will understand that the present invention can be modified and changed in various ways without departing from the spirit and scope of the present invention as set forth in the claims below. [Explanation of symbols]

[0145] 100: Wafer inspection device 110: Wafer 120: Magnetic thin film 200: Image measurement unit 210: microscope main body 220: light source irradiation unit 300: Horizontal magnetic field generating unit 310: Horizontal magnetic body 320: First coil 400: Vertical magnetic field generating unit 410: Vertical magnetic body 420: Second coil 500: Wafer moving stage 510: Second support stand 520: Second rotating / moving bar 530: First support base 540: First rotating moving bar 550: Receiving stand 560: Upper cradle 570: Lower cradle 580: Vertical support D, D1, D2, D3: Defect

Claims

1. a horizontal magnetic field generating unit that is disposed adjacent to the side surface of the wafer and generates a magnetic field such that magnetic field lines travel in a horizontal direction; a vertical magnetic field generating unit disposed below the wafer; an image measurement unit disposed above the wafer and configured to measure an image of the wafer; a wafer moving stage that moves the wafer back and forth and left and right, The vertical magnetic field generating unit generates a magnetic field that cancels out the vertical magnetic field generated by the shift of the horizontal magnetic field. Wafer inspection equipment.

2. The wafer inspection apparatus of claim 1 , wherein the horizontal magnetic field generating units are disposed adjacent to one side of the wafer or adjacent to both sides of the wafer so as to correspond to each other.

3. 2. The wafer inspection device according to claim 1, wherein the horizontal magnetic field generating unit includes a horizontal coil support base and a coil wound around the horizontal coil support base.

4. 2. The wafer inspection device according to claim 1, wherein the vertical magnetic field generating unit includes a vertical coil support base disposed below the wafer in a vertical direction of the wafer, and a vertical coil wound around the vertical coil support base.

5. 2. The wafer inspection device according to claim 1, wherein the image measurement unit includes a microscope main body and a light source irradiation unit.

6. 2. The wafer inspection device of claim 1, wherein the wafer movement stage includes a support on which the wafer and the vertical magnetic field generating unit are placed, a plurality of first rotational movement bars that move the support back and forth in the vertical direction on the surface, a plurality of second rotational movement bars that move the support from side to side in the horizontal direction, and a first support table and a second support table on which the first rotational movement bars and the second rotational movement bars are placed.

7. 2. The wafer inspection device of claim 1, wherein the pedestal includes an upper pedestal on which the wafer is placed, a lower pedestal on which the vertical magnetic field generating unit is placed, and a plurality of vertical support pedestals that fix and support edges of the upper pedestal and the lower pedestal.

8. 2. The wafer inspection device according to claim 1, wherein the vertical magnetic field generating unit applies a magnetic field capable of changing the magnetization state of the wafer from up to down or from down to up.

9. a horizontal magnetic field generating unit that generates a magnetic field on the wafer so that magnetic lines of force move in a horizontal direction; a vertical magnetic field generating unit that generates a magnetic field that cancels out a vertical magnetic field generated on the wafer due to a deviation of the horizontal magnetic field; and an image measurement unit that measures an image of the wafer.

10. The wafer inspection apparatus of claim 9 , wherein the horizontal magnetic field generators are disposed adjacent to one side of the wafer or adjacent to both sides of the wafer so as to face each other.

11. The wafer inspection device according to claim 10 , wherein the horizontal magnetic field generating unit includes a horizontal coil support base and a coil wound around the horizontal coil support base.

12. 10. The wafer inspection device according to claim 9, wherein the vertical magnetic field generating unit includes: a vertical coil support table disposed below the wafer in a vertical direction of the wafer; and a vertical coil wound around the vertical coil support table.

13. 10. The wafer inspection device according to claim 9, wherein the image measurement unit includes a microscope main body and a light source irradiation unit.

14. 10. The wafer inspection apparatus according to claim 9, further comprising a wafer moving stage that moves the wafer back and forth and left and right.

15. 15. The wafer inspection device of claim 14, wherein the wafer movement stage includes a support on which the wafer and the vertical magnetic field generating unit are placed, a plurality of first rotational movement bars that move the support back and forth in the vertical direction on the surface, a plurality of second rotational movement bars that move the support from side to side in the horizontal direction, and a first support table and a second support table on which the first rotational movement bars and the second rotational movement bars are placed.

16. 16. The wafer inspection device of claim 15, wherein the pedestal includes an upper pedestal on which the wafer is placed, a lower pedestal on which the vertical magnetic field generating unit is placed, and a plurality of vertical support pedestals that fixedly support edges of the upper pedestal and the lower pedestal.

17. forming a magnetic thin film on the wafer; applying a horizontal magnetic field to the wafer to form a stripe pattern; determining the uniformity of the wafer by determining the location of stripe defects across the entire area of ​​the wafer.

18. The wafer inspection method according to claim 17, wherein the wafer defect type is inspected by detecting the non-uniformity of the width, direction, or ratio of the stripes.

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