JP2024084365A - Inspection device and inspection method - Google Patents

Abstract

[Problem] To provide an inspection device and an inspection method capable of accurately performing visual inspection of a wafer. [Solution] The inspection device (1, 1A, 1B) includes a camera (50) that captures an image of an inspection object on a wafer, a first judgment unit (10) that detects the inspection object from the image captured by the camera and makes a provisional judgment as to whether the inspection object is good or bad, a three-dimensional shape measuring machine (52) that measures the three-dimensional shape of the inspection object that has been provisionally judged to be abnormal, and a second judgment unit (10) that makes a final judgment as to whether the inspection object is good or bad based on the three-dimensional shape of the inspection object measured by the three-dimensional shape measuring machine and the image captured by the camera or the three-dimensional shape of the inspection object measured by the three-dimensional shape measuring machine. [Selected Figure] Figure 1

Description

The present invention relates to an inspection device and an inspection method, and in particular to a technique for inspecting semiconductor devices formed on a semiconductor wafer.

In the manufacturing process of semiconductor devices, various inspections are carried out at various manufacturing steps to ensure quality and improve yield. For example, in wafer-level inspection, at the stage where multiple chips corresponding to individual semiconductor devices are formed on a semiconductor wafer (hereafter referred to as a wafer), the electrode pads of the semiconductor device are brought into contact with the probe needles of a probe card and a test signal is supplied. Then, the signal output by the semiconductor device in response to this test signal is measured by a tester to electrically inspect whether the semiconductor device is operating normally.

In the above-mentioned wafer-level inspection, ideally, only the oxide film on the surface of the electrode pad is scraped off with the probe needle, and the probe needle is brought into contact with the electrode pad to establish electrical continuity. In the wafer-level inspection, an overdrive is applied to scrape off the oxide film on the surface of the electrode pad with the probe needle. Then, after the wafer-level inspection, the needle marks formed on the electrode pad are detected.

If no needle mark is detected from the electrode pad during the needle mark detection after wafer-level inspection, the measurement is determined to be defective. On the other hand, if the probe needle pierces the electrode pad and the underlying layer of the electrode pad is exposed, the electrode pad is treated as defective.

Patent document 1 discloses a needle mark inspection device for automatically detecting the exposed state of the underlayer of an electrode pad after inspection using a probe needle. In patent document 1, a camera is used to capture an image of the needle mark formed on the electrode pad, and the presence or absence of exposure of the underlayer of the electrode pad is inspected.

JP 2009-289818 A

In the case of wafer appearance inspection, in addition to the above-mentioned needle marks, the image (two-dimensional image) of the wafer taken by a camera may be inspected for the presence or absence of scratches (for example, scratches on a plain wafer or a mirror wafer on which no pattern is formed) or foreign objects.

In the case of wafer appearance inspection, for example, detection of needle marks after wafer-level inspection, the wafer is illuminated with an illumination means after the wafer-level inspection, and an image (two-dimensional image) of the wafer's top surface is captured with a camera. Then, the electrode pads and the underlying layer are distinguished based on the brightness of the image.

When distinguishing between electrode pads and underlayers based on the brightness of an image as described above, it can be difficult to determine whether the brightness of the image is due to the way light hits the surface of the wafer due to its shape, or due to differences in materials. For example, if the proportion of dark areas due to the shape of the wafer surface is large, the electrode pads may be determined to be defective even if the underlayer is not exposed.

In addition, even in visual inspections using two-dimensional images to detect scratches or foreign objects on wafers, depending on the material of the wafer or the shape or type of the scratches or foreign objects, there may be cases where sufficient accuracy cannot be obtained to determine whether the visual inspection results are good or bad.

The present invention was made in consideration of these circumstances, and aims to provide an inspection device and an inspection method that can perform accurate appearance inspection of wafers.

In order to solve the above problem, the inspection device according to the first aspect of the present invention includes a camera that captures an image of an object to be inspected on a wafer, a first judgment unit that detects the object to be inspected from the image captured by the camera and makes a provisional judgment as to whether the object to be inspected is good or bad, a three-dimensional shape measuring machine that measures the three-dimensional shape of the object to be inspected that has been provisionally judged to be abnormal, and a second judgment unit that makes a final judgment as to whether the object to be inspected is good or bad based on the three-dimensional shape of the object to be inspected measured by the three-dimensional shape measuring machine and the image captured by the camera or the three-dimensional shape of the object to be inspected measured by the three-dimensional shape measuring machine.

In the second aspect of the present invention, the inspection device is configured such that the object to be inspected in the first aspect is a needle mark formed on the electrode pad of a wafer when the wafer is electrically inspected using a test head.

In the inspection device according to the third aspect of the present invention, in the second aspect, the first judgment unit detects the area of the needle mark formed on the electrode pad from an image captured by a camera, and makes a provisional judgment of the quality of the electrode pad based on the area.

In the inspection device according to the fourth aspect of the present invention, in the second or third aspect, the second judgment unit makes a final judgment on the quality of the electrode pad based on the maximum valley depth of the electrode pad measured by the three-dimensional shape measuring device.

The inspection device according to the fifth aspect of the present invention is any one of the first to fourth aspects, and includes an alignment unit that acquires the positional relationship between the camera and the three-dimensional shape measuring device.

The inspection device according to the sixth aspect of the present invention is the fifth aspect, in which the alignment unit acquires the positional relationship between the camera and the three-dimensional shape measuring machine based on the measurement results of the alignment mark by the camera and the three-dimensional shape measuring machine.

The inspection method according to the seventh aspect of the present invention includes the steps of taking an image of an object to be inspected on a wafer with a camera, detecting the object to be inspected from the image, and provisionally determining whether the object to be inspected is defective, and measuring the three-dimensional shape of the object to be inspected that has been provisionally determined to be defective with a three-dimensional shape measuring machine, and making a final determination of whether the object to be inspected is defective based on the three-dimensional shape of the object to be inspected measured by the three-dimensional shape measuring machine and the image taken by the camera or the three-dimensional shape of the object to be inspected measured by the three-dimensional shape measuring machine.

The inspection method according to the eighth aspect of the present invention is such that the object to be inspected according to the seventh aspect is a needle mark formed on the electrode pad of a wafer when the wafer is electrically inspected using a test head.

The inspection method according to the ninth aspect of the present invention is the seventh or eighth aspect, and further includes an alignment step for acquiring the positional relationship between the camera and the three-dimensional shape measuring device.

The inspection method according to the tenth aspect of the present invention is the same as the ninth aspect, and includes a step of measuring an alignment mark by a camera and a step of measuring the alignment mark by a three-dimensional shape measuring machine, and in the alignment step, the positional relationship between the camera and the three-dimensional shape measuring machine is obtained based on the measurement results of the alignment mark by the camera and the three-dimensional shape measuring machine.

According to the present invention, a provisional pass/fail judgment of the electrode pads is made using a camera that can perform the judgment at high speed, prior to the actual pass/fail judgment using a three-dimensional shape measuring machine, thereby narrowing down the targets for the actual judgment. This makes it possible to accurately inspect the needle marks formed on the surface of the electrode pads by wafer-level inspection using the three-dimensional shape measuring machine, and also shortens the time required for pass/fail judgment.

FIG. 1 is a diagram showing an inspection apparatus according to a first embodiment of the present invention (during wafer-level inspection). FIG. 2 is a diagram showing the inspection device according to the first embodiment of the present invention (when inspecting electrode pads). FIG. 3 is a block diagram showing a control system of the inspection apparatus according to the first embodiment of the present invention. FIG. 4 is a flowchart showing an inspection method according to the first embodiment of the present invention. FIG. 5 is a diagram showing an example of an image of an electrode pad captured by a 2D camera. FIG. 6 is a diagram showing an example of measurement data obtained by measuring the electrode pad to be judged by the 3D shape measuring device. FIG. 7 is a diagram for explaining the feature amount (maximum valley depth) of the needle mark formed on the electrode pad. FIG. 8 is a flowchart showing an inspection method according to a modified example. FIG. 9 is a flowchart (continuation) showing the inspection method according to the modified example. FIG. 10 is a diagram showing an inspection apparatus according to the second embodiment of the present invention (during wafer-level inspection). FIG. 11 is a plan view and a front view showing an example of an alignment mark. FIG. 12 is a flowchart showing a procedure for aligning the 2D camera and the 3D shape measuring device. FIG. 13 is a diagram showing an example of a captured image of an alignment mark. FIG. 14 is a plan view for explaining the positional relationship between the 2D camera and the 3D shape measuring device. FIG. 15 is a plan view for explaining the positional relationship between the 2D camera and the 3D shape measuring device. FIG. 16 is a diagram showing an inspection apparatus according to a third embodiment of the present invention (during wafer-level inspection). FIG. 17 is a flowchart showing a procedure for aligning the 2D camera and the 3D shape measuring device. FIG. 18 is a block diagram illustrating an example of a 2D camera. FIG. 19 is a diagram showing an example of the field of view of a 2D camera and a beam spot.

Below, an embodiment of the inspection device and inspection method will be described with reference to the attached drawings.

[First embodiment]
In this embodiment, as an example of a wafer appearance inspection, a case where a needle mark formed on an electrode pad P of a wafer W is detected after a wafer-level inspection will be described, but the present disclosure is not limited thereto. For example, this embodiment can also be applied to the measurement (detection) of any inspection object (e.g., a scratch or a foreign object) on the wafer W.

Figures 1 and 2 are diagrams showing an inspection device according to a first embodiment of the present invention. Figure 2 shows the state when a wafer-level inspection is being performed, and Figure 1 shows the state when inspecting the electrode pads P of a wafer W (detecting needle marks) after the wafer-level inspection.

When performing wafer-level inspection, as shown in FIG. 2, a test head 70 is attached to the housing of the measurement unit 100 of the inspection device 1. Next, a test signal is supplied by contacting the probe needles 74 of the probe card 72 with the electrode pads P formed on the surface of the wafer W to be inspected. Then, a signal output by the semiconductor device (chip C) in response to this test signal is measured by a tester to electrically inspect whether the semiconductor device is operating normally. In wafer-level inspection, part of the oxide film on the surface of the electrode pad P is scraped off by the probe needles 74, establishing electrical continuity between the probe needles 74 and the electrode pads P.

When inspecting the electrode pads P of the wafer W, a three-dimensional shape measuring machine (hereinafter referred to as a 3D shape measuring machine) 52 is attached to the measurement unit 100 of the inspection device 1, as shown in FIG. 1.

In the inspection of the electrode pad P of the wafer W, a provisional judgment is first made using a 2D camera (e.g., an imaging unit for aligning the wafer W) 50. In the provisional judgment, the electrode pad P is imaged by the 2D camera 50. Then, from the image captured by the 2D camera 50, the needle mark formed on the electrode pad P in the wafer level inspection is detected, and the quality (OK/NG) of the detected needle mark is judged. In the judgment of the quality of the needle mark using the image captured by the 2D camera 50, the quality of the needle mark is judged based on the feature amount (first feature amount, for example, area) related to the needle mark. Specifically, when the area of the needle mark on the electrode pad P exceeds the provisional judgment threshold (first threshold), it is highly likely that the needle mark is dug deep and that the underlying layer is highly likely to be exposed. Therefore, when the area of the needle mark on the electrode pad P exceeds the provisional judgment threshold (first threshold), the electrode pad P is provisionally judged to be abnormal (NG).

Next, for the electrode pads P that were determined to be NG in the provisional determination, a determination (main determination) is made as to whether the needle marks are good or bad (OK/NG) using the 3D shape measuring device 52.

The 3D shape measuring machine 52 is a device for measuring the three-dimensional shape of the electrode pad P without contacting the surface of the electrode pad P. The measurement method in the 3D shape measuring machine 52 is not particularly limited, and for example, white light interferometry, SD-OCT (Spectral Domain Optical Coherence Tomography), FD-OCT (Fourier Domain Optical Coherence Tomography), laser confocal method, triangulation method, light section method, pattern projection method, optical comb method, and focus variation method can be applied. In addition, as a 3D shape measuring machine 52 using white light interferometry, for example, those described in JP 2016-080564 A or JP 2016-161312 A can be applied.

In the determination of the quality of the needle mark using the 3D shape measuring machine 52, only the electrode pads P that are determined to be NG in the provisional determination are subject to the actual determination. Then, the shape of the electrode pads P that are the subject of the actual determination is measured using the 3D shape measuring machine 52, and the feature amount (second feature amount, for example, the maximum valley depth Sv of the needle mark formed on the electrode pad P) of the electrode pad P is obtained. Here, the maximum valley depth Sv is a parameter defined by JIS (Japanese Industrial Standards) B 0681-2:2018 or ISO (International Organization for Standardization) 25178-2:2012. If the maximum valley depth Sv exceeds the actual determination threshold (second threshold), it is determined to be abnormal (NG) because the underlying layer is exposed by the needle mark and there is a high possibility that damage to the circuit has occurred.

According to this embodiment, by using the 3D shape measuring machine 52, it is possible to accurately inspect the needle marks formed by wafer-level inspection. In addition, in this embodiment, a pass/fail judgment using the 2D camera 50, which can be performed at high speed, is performed prior to the pass/fail judgment using the 3D shape measuring machine 52, narrowing down the targets for this judgment, thereby shortening the time required for the pass/fail judgment.

(Configuration of the inspection device)
1 and 2, the inspection device 1 according to this embodiment includes a measurement unit 100 and a loader section 200 that supplies and retrieves a wafer W to be inspected to the measurement unit 100. The measurement unit 100 and the loader section 200 are separable. Although a plurality of measurement units 100 and loader sections 200 can be provided, only one of each is shown for the sake of simplicity of explanation.

The loader section 200 has a load port on which a wafer cassette is placed, and a transport unit 202 (see FIG. 3) that transports wafers W between each of the measurement units 100 and the wafer cassette.

When a wafer W is supplied from the loader section 200 to each measurement unit 100, the wafer W is adsorbed and held on the holding surface of the stage ST of each measurement unit 100.

The stage movement mechanism 102 supports the underside of the stage ST (the surface opposite to the holding surface on which the wafer W is adsorbed and held). The stage movement mechanism 102 is configured to be movable in the X, Y and Z directions, and rotatable in the θ direction (the direction of rotation around the Z direction). As a result, the wafer W adsorbed and held on the holding surface of the stage ST can be moved in the X, Y and Z directions and rotated in the θ direction together with the stage ST by the stage movement mechanism 102.

As shown in FIG. 2, during wafer-level inspection, a test head 70 is attached to the measurement unit 100 of the inspection device 1.

The probe card 72 is provided at a position facing the stage ST and is disposed approximately parallel to the holding surface of the stage ST. The probe card 72 has a plurality of probe needles 74 formed on the surface facing the stage ST. The probe card 72 is connected to the tester body via the test head 70.

A number of chips C are formed on the wafer W, and each chip C has one or more electrode pads P. The stage ST is moved in the XYZ directions or rotated in the θ direction by the stage movement mechanism 102, thereby aligning the wafer W with the probe card 72 so that each probe needle 74 contacts the corresponding electrode pad P.

After the inspection device 1 aligns and contacts the probe needles 74 with the electrode pads P, an electrical signal is sent from the tester body to the chip C via the test head 70, the probe card 72, and the probe needles 74, and an inspection (wafer-level inspection) of the electrical characteristics of the chip C on the wafer W is performed. The results of the electrical characteristic inspection are output by the input/output unit (see Figure 3) in a form that can be confirmed by the operator.

After the inspection of the electrical characteristics of the chips C on the wafer W is completed, the wafer W is transported by the transport unit from the inspection device 1 to the loader section 200 and collected.

As shown in FIG. 1, when inspecting the electrode pads P of the wafer W, a 3D shape measuring machine 52 is attached to the measurement unit 100 of the inspection device 1. Then, the 2D camera 50 and the 3D shape measuring machine 52 sequentially detect the needle marks formed on the electrode pads P during wafer-level inspection, and a quality judgment is made on the needle marks formed on the electrode pads P.

In this embodiment, the positional relationship between the 2D camera 50 and the 3D shape measuring device 52 is assumed to be known or calibrated.

In addition, in this embodiment, the 2D camera 50 and the 3D shape measuring device 52 are attached separately, but this is not limited to the above. For example, the 2D camera 50 and the 3D shape measuring device 52 may be switchable by a revolver mechanism.

In addition, in this embodiment, the test head 70 and the 3D shape measuring machine 52 are detachable from the measurement unit 100 of the inspection device 1, but this is not limited to the above. For example, the wafer-level inspection and the inspection of the electrode pads P after the wafer-level inspection may be performed by separate devices.

Furthermore, the test head 70, the 2D camera 50, the 3D shape measuring device 52, etc., and the stage ST may be movable relative to each other, and the test head 70, the 2D camera 50, the 3D shape measuring device 52, etc. may be movable relative to the stage ST.

(Inspection equipment control system)
FIG. 3 is a block diagram showing a control system of the inspection apparatus according to the first embodiment of the present invention.

As shown in FIG. 3, the inspection device 1 according to this embodiment includes a control unit 10, an input/output unit 12, a transport unit drive unit 14, a transport arm drive unit 16, and a measurement control unit 18.

The control unit 10 includes a processor (e.g., a CPU (Central Processing Unit), MPU (Micro Processor Unit), etc.), a ROM (Read Only Memory), a RAM (Random Access Memory), and a storage device (e.g., a HDD (Hard Disk Drive) or an SSD (Solid State Drive)). In the control unit 10, the processor executes various programs, such as a control program, stored in the storage device, thereby realizing the functions of each part of the inspection device 1. The control unit 10 is an example of a first judgment unit and a second judgment unit.

The input/output unit 12 includes a display unit (e.g., a liquid crystal display) that displays a GUI (Graphical User Interface) for operating the inspection device 1, and an operation unit (e.g., a touch panel, keyboard, pointing device, etc.) for receiving operation input from the user.

The transport unit drive section 14 includes a motor and the like for moving the transport unit 202 in the X, Y and Z directions and rotating it in the θ direction (around the Z direction) within the loader section 200.

The transport arm drive unit 16 includes a motor for extending and retracting the transport arm 204 attached to the transport unit 202 in its length direction, and a control valve for adsorbing the wafer W to the suction hole of the transport arm 204. This control valve is connected to a vacuum (pump) provided at the installation location of the inspection device 1.

The control unit 10 controls the transport unit 202 and the transport arm 204 via the transport unit drive unit 14 and the transport arm drive unit 16, respectively, to remove wafers W from multiple wafer cassettes and to load and unload wafers W into and from multiple measurement units 100.

The needle alignment camera 54 is a device for detecting the tip position of the probe needle 74, and is provided, for example, on the stage ST. The control unit 10 aligns the probe needle 74 with the electrode pad P based on the detection result of the tip position of the probe needle 74 and the detection result of the electrode pad P by the 2D camera 50.

The measurement control unit 18 performs drive control of the test head 70 for inspecting the wafer W provided in the measurement unit 100, image capture control of the 2D camera 50, measurement control of the 3D shape measuring machine 52, and image capture control of the needle alignment camera 54 in accordance with the control signal from the control unit 10. Note that the test head 70 and 2D camera 50 may be, for example, those described in JP 2019-102591 A.

(Inspection method)
FIG. 4 is a flowchart showing an inspection method according to the first embodiment of the present invention.

When inspection of a lot of wafers W begins, a parameter i indicating the number of wafers W to be inspected is set to i=1 (step S10). Then, the first wafer W1 is loaded onto the stage ST (step S12), and a wafer-level inspection of the wafer W1 is performed (step S14).

After the wafer-level inspection, the quality of the electrode pads P is determined using a 2D camera 50 and a 3D shape measuring machine 52 (steps S16 and S18).

In step S16, the quality of the electrode pads P is determined using the 2D camera 50. Detection of the electrode pads P using the 2D camera 50 can be performed in a shorter time than when using the 3D shape measuring machine 52. For this reason, in step S16, all electrode pads P on the wafer W1 may be inspected.

Figure 5 shows an example of an image IMG captured by the 2D camera 50 of the electrode pad P.

In step S16, first, the electrode pads P are detected. As shown in FIG. 5, the surface of the wafer W (e.g., silicon) and the surface of the electrode pads P (e.g., aluminum) have different light reflectances, and therefore have different brightnesses in the captured image IMG. Specifically, the surface of the electrode pads P is brighter than the surface of the wafer W. The control unit 10 detects the electrode pads P based on the difference in brightness in the captured image IMG. Note that in addition to the difference in brightness in the captured image IMG, the electrode pads P may also be detected based on the design values of the shape, size, or arrangement of the electrode pads P.

Next, the needle mark formed on the electrode pad P is detected from the image captured by the 2D camera 50. As shown in FIG. 5, the needle mark M is the part of the electrode pad P that has been dug by the probe needle 74, so light is scattered at the needle mark M and it is difficult for the light to reach the 2D camera 50. For this reason, the needle mark M is darker than the parts of the electrode pad P other than the needle mark M. The control unit 10 detects the area of the electrode pad P detected from the captured image IMG that is darker than the surrounding area as the needle mark M.

The order of detecting the electrode pads P and the needle marks M is not particularly limited, and they may be performed sequentially or simultaneously.

Next, the control unit 10 calculates a first feature amount based on the detection result of the needle mark M, and makes a provisional judgment of the quality of the needle mark M. For example, the area of the needle mark M can be used as the first feature amount. If the area of the needle mark M detected from the captured image IMG exceeds the provisional judgment threshold (first threshold), the control unit 10 provisionally judges the electrode pad P to be abnormal (NG) since there is a high possibility that the needle mark is deeply dug and the underlying layer is exposed.

Here, the quality of the needle mark M may be affected by the amount of movement (distance dragged) of the probe needle 74 on the electrode pad P, etc. For this reason, the provisional judgment threshold (first threshold) for the area of the needle mark M may be set based on the thickness of the probe needle 74, for example, to a value approximately equal to the thickness of the probe needle 74 or the cross-sectional area in the XY plane. In this case, the conditions for a provisional judgment of NG can be made stricter, and the accuracy of the inspection can be improved.

The provisional judgment is not limited to the above example. For example, the provisional judgment may be made based on the thickness of the electrode pad P, the proportion of the area of the needle mark M to the electrode pad P, the position, or the strength (fragility) of the material of the electrode pad P. For example, the thicker the electrode pad P is, the less likely the underlying layer is to be exposed, so the provisional judgment threshold (first threshold) for the area of the needle mark M may be made large. Also, the lower the strength (fragility) of the material of the electrode pad P is, the more likely it is that the electrode pad P will be torn, so the provisional judgment threshold (first threshold) for the area of the needle mark M may be made small.

In addition, when the proportion of the area of the needle mark M to the electrode pad P is equal to or greater than a reference value, when the portion of the electrode pad P other than the needle mark M is equal to or less than a reference value, when the distance between the end of the electrode pad P and the needle mark M is equal to or less than a reference value, etc., it is considered that there is a high possibility that the electrode pad P will tear or the like, and therefore it may be provisionally determined to be abnormal (NG). In this case, each reference value may be adjusted according to the strength of the material of the electrode pad P; for example, the lower the strength (fragile) the electrode pad P is, the stricter the criteria for provisionally determining it to be abnormal (NG) may be.

Next, the electrode pads P that were determined to be NG in the provisional judgment (step S16) are subjected to a pass/fail judgment (final judgment) using the 3D shape measuring device 52 (step S18).

Figure 6 shows an example of measurement data obtained by measuring the electrode pad P that is the subject of this evaluation using the 3D shape measuring machine 52. In Figure 6, the three-dimensional coordinates measured by the 3D shape measuring machine 52 are shown three-dimensionally using light and dark.

In step S18, first, the three-dimensional shape of the area including the electrode pad P that was provisionally determined to be NG is measured. In this embodiment, the positional relationship between the 2D camera 50 and the 3D shape measuring machine 52 is known or has been calibrated. Therefore, based on the position (coordinates) of the electrode pad P in the image IMG captured by the 2D camera 50, the 3D shape measuring machine 52 can be used to measure the area including the electrode pad P that was provisionally determined to be NG.

As shown in FIG. 6, the measurement data R1 from the 3D shape measuring machine 52 includes the measurement results of the three-dimensional coordinates (XYZ coordinates) for each position of the area including the electrode pad P that is the subject of the actual judgment and was provisionally judged NG, and the measurement results of the three-dimensional coordinates of an area including, for example, an area Ws on the surface of the wafer W (chip C) between the electrode pad P that is the subject of the actual judgment and an adjacent electrode pad.

The control unit 10 extracts the electrode pad P to be subjected to this judgment from the measurement data R1. In this embodiment, for example, the electrode pad P is extracted based on the difference h between the height (Z coordinate) of the electrode pad P to be subjected to this judgment and the height (Z coordinate) of the area Ws on the surface of the wafer W (chip C) between adjacent electrode pads. Specifically, the control unit 10 extracts the surface area of the electrode pad P by, for example, excluding the area that is lower than the height (Z coordinate) of the electrode pad P by the thickness.

Next, the control unit 10 calculates a second feature value related to the needle mark M from the measurement data R2 extracted from the surface area of the electrode pad P. In this embodiment, the maximum valley depth Sv defined by JIS B 0681-2:2018 or ISO 25178-2:2012 is used as the second feature value.

Figure 7 is a diagram for explaining the characteristic quantity (maximum valley depth Sv) of the needle mark M formed on the electrode pad P. In Figure 7, the three-dimensional shape (unevenness) of the surface of the electrode pad P is shown by a curve along the X direction.

The maximum valley depth Sv is the absolute value of the minimum height based on the average plane Pm where the height (Z coordinate) on the surface of the electrode pad P is the average value (arithmetic mean value). In FIG. 7, Sp is the maximum peak height, which is the maximum value based on the average plane Pm. Sz is the maximum height indicating the distance from the highest point to the lowest point on the surface of the electrode pad P, and Sz = Sp + Sv.

The control unit 10 performs a final judgment of the quality of the electrode pad P based on, for example, the relationship between the maximum valley depth Sv and the design value of the thickness of the electrode pad P. Specifically, for example, if the maximum valley depth Sv is equal to or greater than the design value of the thickness of the electrode pad P, or equal to or greater than 90% of this design value, the electrode pad P is judged to be NG.

Note that this determination is not limited to the above example. For example, the main determination threshold (second threshold) for the maximum valley depth Sv may be changed based on the thickness of the electrode pad P, the ratio of the area of the needle mark M to the electrode pad P, the position, or the strength (fragility) of the material of the electrode pad P. For example, the thicker the electrode pad P is, the less likely the underlayer is to be exposed, so the main determination threshold (second threshold) for the maximum valley depth Sv may be set to a value closer to the design value of the thickness of the electrode pad P. Also, the lower the strength (fragility) of the material of the electrode pad P is, the more likely it is that the electrode pad P will crack, so the main determination threshold (second threshold) for the maximum valley depth Sv may be set to a value smaller than the design value of the thickness of the electrode pad P.

In addition, if the proportion of the area of the needle mark M relative to the electrode pad P is equal to or greater than a reference value, if the portion of the electrode pad P other than the needle mark M is equal to or less than a reference value, or if the distance between the end of the electrode pad P and the needle mark M is equal to or less than a reference value, it is considered highly likely that the electrode pad P will tear, and so it may be judged as NG. In this case, each reference value may be adjusted according to the strength of the material of the electrode pad P; for example, the lower the strength (more fragile) the electrode pad P is, the stricter the criteria for judging it as NG may be.

For example, if the area of the needle mark M is used as the first feature in the provisional judgment, the actual judgment may use the feature that the distance between the end of the electrode pad P and the needle mark M is less than or equal to a reference value, together with the second feature (maximum valley depth Sv) measured by the 3D shape measuring device 52.

When the wafer-level inspection (step S14) and the inspection of the electrode pads P (steps S16 and S18) of the wafer W1 are completed, the wafer W1 is unloaded from the stage ST (step S20). Then, i=i+1 is set (No in step S22, step S24), and the wafer-level inspection (step S14) and the inspection of the electrode pads P (steps S16 and S18) of the next wafer W2 are performed.

Steps S12 to S24 are repeated, and when the wafer-level inspection (step S14) and the inspection of the electrode pads P (steps S16 and S18) of the wafers Wi of the lot being inspected are completed (Yes in step S22), the inspection flow ends.

The 3D shape measuring machine 52 has the advantage of being able to obtain information in the Z direction, but compared to the 2D camera 50, the measurement speed is slower because of the addition of one axis. For example, when a white light interference microscope or a device using a focus variation method is used as the 3D shape measuring machine 52, a high NA (Numerical Aperture) lens with high sensitivity on an inclined surface is used to obtain a three-dimensional shape. A high NA lens has a large magnification, so the measurement field of view is narrow. Therefore, the area on the wafer W that can be measured with one scan is small. In order to measure a wide area on the wafer W, it is necessary to move the measurement field of view in the XY direction and perform multiple scans in the Z direction, so the measurement takes time. On the other hand, in the case of the 2D camera 50, since there is no restriction as in the case of the 3D shape measuring machine 52, a lens with a large field of view can be used. In addition, in the case of the 2D camera 50, since there is no need for scanning in the Z direction, the measurement can be performed at high speed.

According to this embodiment, the quality of the electrode pads P is judged using the 2D camera 50, which can be performed at high speed, prior to the quality judgment by the 3D shape measuring machine 52, thereby narrowing down the targets for this judgment. This allows the 3D shape measuring machine 52 to accurately inspect the needle marks M formed on the surfaces of the electrode pads P by wafer-level inspection, and also shortens the time required for the quality judgment.

In this embodiment, the object to be inspected is the needle mark M formed on the electrode pad P, but as mentioned above, this disclosure is not limited to this. For example, this embodiment can also be applied to visual inspection for detecting objects to be inspected, such as scratches or foreign objects on the wafer W.

For example, when the object to be inspected is a scratch on a wafer W, the wafer W may be determined to be abnormal if at least one of the following features exceeds a reference value: scratch size (e.g., maximum dimension or minimum dimension), scratch depth (e.g., maximum valley depth Sv or maximum height Sz), scratch area (e.g., the proportion of the scratch area per unit area of the wafer W), and scratch arrangement (e.g., the number per unit area, etc.). Also, instead of or in addition to the above features, the wafer W may be determined to be abnormal if the distance between the scratch and the device is equal to or less than a reference value.

In addition, when the object to be inspected is a foreign object, the wafer W may be determined to be abnormal if at least one of the following features exceeds a reference value: size of the foreign object (e.g., maximum dimension or minimum dimension) and arrangement of the foreign object (e.g., number per unit area, etc.). In addition, instead of or in addition to the above features, the quality of the wafer W may be determined based on the type of foreign object. For example, if it is estimated based on the three-dimensional shape of the foreign object that the foreign object can be easily removed by air or the like, the wafer W may be determined to be normal regardless of the above features.

[Modification]
In the first embodiment, the provisional judgment using the 2D camera 50 and the final judgment using the 3D shape measuring machine 52 are performed for each wafer in that order, but the order of inspection of the wafers W is not limited to this. For example, the provisional judgment using the 2D camera 50 may be performed for one lot first, and then the final judgment using the 3D shape measuring machine 52 may be performed for the wafers W including the electrode pads P that have been provisionally judged to be abnormal.

Figures 8 and 9 are flowcharts showing an inspection method according to a modified example. Figure 8 is a flowchart of a provisional judgment using a 2D camera 50, and Figure 9 is a flowchart of a final judgment using a 3D shape measuring device 52.

When the provisional judgment of the lot of wafers W is started, as shown in FIG. 8, the parameter i indicating the number of wafers W to be inspected is set to i=1 (step S50). Then, the first wafer W1 is loaded onto the stage ST (step S52), and the quality (provisional judgment) of the electrode pads P is performed using the 2D camera 50 (step S54).

When the provisional judgment (step S54) is completed, the wafer W1 is unloaded from the stage ST (step S56). Then, i = i + 1 is set (No in step S58, step S60), and a provisional judgment (step S54) is performed on the next wafer W2.

Steps S52 to S60 are repeated, and when the provisional judgment (step S54) of the wafers Wi in the lot being inspected is completed (Yes in step S58), the provisional judgment flow ends.

Next, when the actual judgment of the wafer W lot is started, as shown in FIG. 9, the parameter j of the number of wafers W to be inspected is set to j=1 (step S70). Then, if the first wafer W1 does not include an electrode pad P that was provisionally judged to be abnormal (No in step S72), the target of the actual judgment is changed to j=j+1 (step S74).

On the other hand, if the first wafer W1 contains an electrode pad P that is provisionally determined to be abnormal (Yes in step S72), the wafer W1 is loaded onto the stage ST (step S76), and the quality of the electrode pad P is determined (main determination) using the 3D shape measuring device 52 (step S78).

When this determination (step S78) is completed, wafer W1 is unloaded from stage ST (step S80). Then, j = j + 1 is set (No in step S82, step S74), and a provisional determination (steps S72 to S82) is made for the next wafer W2.

Steps S72 to S82 are repeated, and when the provisional judgment (steps S72 to S82) of the wafer Wj in the lot being inspected is completed (Yes in step S82), this judgment flow ends.

Even in this modified example, the quality of the electrode pad P is judged using the 2D camera 50 prior to the quality judgment using the 3D shape measuring device 52, so that the inspection of the needle marks M formed on the surface of the electrode pad P can be performed accurately and quickly.

Note that Figures 8 and 9 do not include a wafer-level inspection step, and show a procedure for inspecting electrode pads P after wafer-level inspection. The present disclosure is not limited to this, and wafer-level inspection may be included in the flow of Figures 8 and 9 (for example, between steps S52 and S54 in Figure 8).

Second Embodiment
In the first embodiment, it is assumed that the positional relationship between the 2D camera 50 and the 3D shape measuring machine 52 is known or has been calibrated. In contrast, in the present embodiment, the 2D camera 50 and the 3D shape measuring machine 52 are aligned.

That is, in this embodiment, after the wafer-level inspection (step S14) and before the inspection of the electrode pads P (steps S16 and S18), the control unit 10 aligns the 2D camera 50 with the 3D shape measuring device 52. Here, the control unit 10 is an example of an alignment unit.

Figure 10 is a diagram showing an inspection apparatus according to a second embodiment of the present invention (during wafer-level inspection). As shown in Figure 10, the inspection apparatus 1A according to this embodiment is provided with a substage SST connected to the stage ST, and an alignment mark MA is formed on the substage SST.

Figure 11 shows a plan view and a front view of an example of an alignment mark MA. Three examples of alignment marks MA are shown in Figure 11. Note that the coordinate axes shown in the lower left of Figure 11 are a coordinate system based on the inspection device 1A (stage ST).

As shown in FIG. 11, the alignment mark MA according to this embodiment has a cross shape formed by combining two perpendicular line segments in an XY plane view, and has a step in the Z direction.

Here, it is desirable that the alignment mark MA and the underlying sub-stage SST are made of different materials.

In the example shown in FIG. 11(a), the cross-shaped portion of the alignment mark MA protrudes from the surface of the substage SST, and the cross-sectional shape of the protruding portion is rectangular. On the other hand, in the example shown in FIG. 11(b), the cross-shaped portion of the alignment mark MA is recessed from the surface of the substage SST, and the cross-sectional shape of the recessed portion is rectangular. Note that in FIG. 11(b), the cross-sectional shape of the recessed portion may be rounded. Also, in the example shown in FIG. 11(c), like in FIG. 11(a), the cross-shaped portion of the alignment mark MA protrudes from the surface of the substage SST, but the tip shape of the protruding portion is rounded. Either example can be applied to the alignment between the 2D camera 50 and the 3D shape measuring device 52.

In the example shown in FIG. 11, the shape of the alignment mark MA is a cross, but is not limited to this. The alignment mark MA may be, for example, a shape having two independent directional components, specifically, a rectangle, a rhombus, a triangle, an oval (e.g., an ellipse, an oval, an egg shape, etc.), or an L-shape. In addition, even if the alignment mark MA does not have two independent directional components but is circular, its center coordinates can be determined and used, so it can be applied to the alignment between the 2D camera 50 and the 3D shape measuring machine 52 according to this embodiment.

Figure 12 is a flowchart showing the procedure (alignment steps) for aligning the 2D camera 50 and the 3D shape measuring device 52.

First, the substage SST is moved under the 2D camera 50 to capture an image of the alignment mark MA (step S100). In step S100, the substage SST is moved under the 2D camera 50 based on, for example, the design value of the position of the substage SST.

Next, the XY coordinates (Xs, Ys) of the stage ST are read, and the alignment mark MA is imaged using the 2D camera 50. If the 2D camera 50 is a color camera, the image may be converted to a grayscale image.

Figure 13 is a diagram showing an example of a captured image of the alignment mark MA. Note that the coordinate axes shown in the lower left of Figure 13 are a coordinate system based on the inspection device 1A (stage ST).

In FIG. 13, VF1 indicates the field of view of the 2D camera 50, and the center of the field of view VF1 in the coordinate system of the stage ST is (Xs2, Ys2). Note that the center of the field of view VF1 in the field of view coordinate system of the 2D camera 50 is (0, 0). Also, the number of pixels in the X direction of the field of view VF1 is n.

As shown in FIG. 13, the alignment mark MA is extracted from the captured image at a certain cross section (e.g., X=XL1, XL2, Y=YL1, YL2, etc.), and the center of the alignment mark MA, i.e., the intersection point of the cross shape (Xc2, Yc2), is calculated.

In the example shown in FIG. 13, the alignment mark MA is brighter than the surface of the substage SST. In the cross section extracted at Y=YL1, a portion where the brightness exceeds the threshold value th is detected corresponding to the position of the alignment mark MA. The average value of the pixel positions PxID of the portion where the brightness exceeds the threshold value th is found, and the average value of PxID is multiplied by a coefficient for converting the pixel position PxID to distance. This determines the X coordinate X(YL1) of the center of the alignment mark MA in the cross section extracted at Y=YL1 (the X coordinate in the field of view coordinate system of the 2D camera 50).

As shown in FIG. 13, the XY coordinates (XY coordinates in the visual field coordinate system of the 2D camera 50) of the center of the alignment mark MA are calculated for multiple cross sections in the XY direction. Then, the average of these values is calculated as the XY coordinates (XY coordinates in the visual field coordinate system of the 2D camera 50) (Xc2, Yc2) of the center of the alignment mark MA.

The coordinates (Xc2, Yc2) of the center of the alignment mark MA are expressed by the following formula. In the formula below, the numbers of cross sections taken in the X and Y directions are N and M, respectively.

Xc2 = {X(YL1) + X(YL2) + X(YL3) + ... + X(YLN)} / N
Yc2 = {Y(XL1) + Y(XL2) + Y(XL3) + ... + Y(XLM)} / M
In the example shown in FIG. 13, it is desirable to extract the cross section at a position that is about 20% from the edge of the field of view VF.

Next, the position of the alignment mark MA in the coordinate system of the stage ST is found. The position of the center of the alignment mark MA in the coordinate system of the stage ST is (Xc2 + Xs2, Yc2 + Ys2).

Next, the substage SST is moved under the 3D shape measuring machine 52 to measure the alignment mark MA (step S102). In step S102, similar to step S100, the shape of the alignment mark MA is measured and the center of the alignment mark MA is found. In step S102, the alignment mark MA is detected using the difference in height in the Z direction in the 3D shape data, rather than the brightness of the alignment mark MA. If the XY coordinates of the center of the alignment mark MA in the visual field coordinate system of the 3D shape measuring machine 52 are (Xc3, Yc3) and the center of the visual field of the 3D shape measuring machine 52 in the coordinate system of the stage ST is (Xs3, Ys3), then the position of the center of the alignment mark MA in the coordinate system of the stage ST is (Xc3 + Xs3, Yc3 + Ys3).

In the case of a 3D shape measuring machine 52 that uses a method such as focus variation, instead of acquiring 3D shape data, a 2D image of the alignment mark MA may be acquired using a camera mounted on the 3D shape measuring machine 52, and alignment may be performed using this 2D image.

Next, the positional relationship between the 2D camera 50 and the 3D shape measuring device 52 is determined (step S104).

As described above, the positions of the alignment marks MA determined by the 2D camera 50 and the 3D shape measuring device 52, respectively, are (Xc2+Xs2, Yc2+Ys2) and (Xc3+Xs3, Yc3+Ys3) in the coordinate system of the stage ST.

Figures 14 and 15 are plan views for explaining the positional relationship between the 2D camera 50 and the 3D shape measuring machine 52. Figure 15 is an enlarged view of area XV in Figure 14. In Figure 15, the fields of view of the 2D camera 50 and the 3D shape measuring machine 52 are VF1 and VF2, respectively.

The position of the electrode pad P measured by the 2D camera 50 is assumed to be (Xpn, Ypn) in the coordinate system of the stage ST. In this case, the position of the 3D shape measuring device 52 as seen from the 2D camera 50 is (Xc3 + Xs3 - Xc2 - Xs2, Yc3 + Ys3 - Yc2 - Ys2).

Therefore, the position of the electrode pad P measured by the 2D camera 50, i.e., (Xpn, Ypn) in the coordinate system of the stage ST, can be measured by the 3D shape measuring device 52 as (Xpn + Xc3 + Xs3 - Xc2 - Xs2, Ypn + Yc3 + Ys3 - Yc2 - Ys2) in the coordinate system of the stage ST.

The conversion from the coordinate system of the 2D camera 50 to the coordinate system of the stage ST is as follows. The electrode pad P located at the position (Xp2, Yp2) in the coordinate system of the 2D camera 50 is (Xpn, Ypn) = (Xs2 + Xp2, Ys2 + Yp2) in the coordinate system of the stage ST.

In the inspection device 1A, drift of the 2D camera 50 or the 3D shape measuring machine 52 caused by temperature changes may cause the positional relationship between the 2D camera 50 and the 3D shape measuring machine 52 to fluctuate. According to this embodiment, the accuracy of the inspection of the electrode pad P can be improved by aligning the 2D camera 50 and the 3D shape measuring machine 52.

The alignment according to this embodiment is not limited to a specific frequency, and may be performed for each wafer W to be inspected or for each lot. The timing of the alignment can be determined, for example, based on the degree of drift caused by the environment (temperature change).

In addition, in this embodiment, the substage SST on which the alignment mark MA is formed is connected to the stage ST, but the present disclosure is not limited to this. For example, the above-mentioned alignment mark MA may be provided on the wafer W and applied to the alignment between the 2D camera 50 and the 3D shape measuring machine 52.

[Third embodiment]
In the second embodiment, an alignment mark MA is provided for aligning the 2D camera 50 and the 3D shape measuring machine 52. In contrast, in the third embodiment, the 2D camera 50 and the 3D shape measuring machine 52 are aligned without using the alignment mark MA.

Figure 16 shows an inspection device according to a third embodiment of the present invention (during wafer-level inspection).

As shown in FIG. 16, in the inspection device 1B according to this embodiment, a needle alignment camera 54 and a mirror stage MST with a mirror formed on its upper surface are both connected to the end of the stage ST.

In this embodiment, the needle alignment camera 54 is used to detect the beams output from the 2D camera 50 and the 3D shape measuring machine 52, thereby determining the positional relationship between the 2D camera 50 and the 3D shape measuring machine 52.

Figure 17 is a flowchart showing the procedure for aligning the 2D camera 50 and the 3D shape measuring device 52. Figure 18 is a block diagram showing an example of the 2D camera 50.

First, the 2D camera 50 is calibrated (step S200). In step S200, the installation errors of the light source 500 and the image sensor 512 (see FIG. 18), etc., caused by temperature changes in the inspection device 1B and its installation environment are measured and calibrated.

In step S200, first, the mirror stage MST is moved below the 2D camera 50, and a beam L1 is output from the light source 500 mounted on the 2D camera 50 toward the mirror stage MST. The beam output from the light source 500 is collimated by the collimator lens 502, reflected in sequence by the half mirror 504 and mirror 506, and focused by the condenser lens 508 to reach the mirror stage MST. The reflected light from the mirror stage MST passes through the condenser lens 508 and mirror 506, passes through the half mirror 504, and is focused on the image sensor 512 by the condenser lens 510. In this way, the beam L1 reflected on the upper surface of the mirror stage MST is detected by the image sensor 512 of the 2D camera 50.

The optical system of the 2D camera 50 is not limited to the example shown in FIG. 18, and for example, the mirror 506 may be omitted.

In step S200, it is assumed that beam L1 is seen at position (ΔX2d, ΔY2d) in the coordinate system of the 2D camera 50 (see Figure 19).

Next, the stage ST is moved so that the focus of the beam L1 from the 2D camera 50 can be observed at the center of the field of view of the needle alignment camera 54, and the coordinates of the beam L1 are detected (step S202). Here, the field of view size of the needle alignment camera 54 is sufficiently larger than the spot diameter of the beam L1 mounted on the 2D camera 50 and sufficiently larger than the spot diameter of the measurement light of the 3D shape measuring device 52.

In the coordinate system of the needle alignment camera 54, the position of the beam L1 is (ΔXp1, ΔYp1), and the position of the stage ST at this time is (Xs1, Ys1). At this time, the center A of the field of view VF1 of the 2D camera 50 in the coordinate system of the stage ST is expressed by the following formula.

A = (Xs1 - ΔX2d - ΔXp1, Ys1 - ΔY2d - ΔYp1)
Next, the stage ST is moved so that the measurement light L2 (e.g., white light of a white light interference microscope) from the 3D shape measuring device 52 can be observed at the center of the field of view of the needle alignment camera 54, and the coordinates of the measurement light L2 are detected (step S204). In the coordinate system of the needle alignment camera 54, the beam position of the 3D shape measuring device 52 is (ΔXp2, ΔYp2), and the position of the stage ST at this time is (Xs2, Ys2). At this time, the position B of the 3D shape measuring device 52 in the coordinate system of the stage ST is expressed by the following equation.

B = (Xs2 - ΔXp2, Ys2 - ΔYp2)
Next, the positional relationship between the 2D camera 50 and the 3D shape measuring machine 52 is obtained (step S206). The position of the 3D shape measuring machine 52 relative to the 2D camera 50 is B-A.

In the inspection device 1B, the positional relationship between the 2D camera 50 and the 3D shape measuring machine 52 fluctuates due to drift of the 2D camera 50 or the 3D shape measuring machine 52 caused by temperature changes. According to this embodiment, the accuracy of the inspection of the electrode pad P can be improved by aligning the 2D camera 50 and the 3D shape measuring machine 52.

As with the second embodiment, the alignment according to this embodiment is not limited to a specific period, such as for each wafer W to be inspected or for each lot. The timing of alignment can be determined, for example, based on the degree of drift caused by the environment (temperature change).

Note that if the center A of the field of view VF1 of the 2D camera 50 and the focal position of the beam L1 have already been calibrated, the calibration using the mirror stage MST (step S200) can be omitted.

In addition, if the 3D shape measuring device 52 is provided with a light source for an external alignment beam, alignment can be performed in the same manner as in the third embodiment by using the same light source.

1, 1A, 1B... inspection device, 10... control unit, 12... input/output unit, 14... transport unit drive unit, 16... transport arm drive unit, 18... measurement control unit, 20... measurement unit, 50... 2D camera, 52... 3D shape measuring device, 54... needle alignment camera, 70... test head

Claims (10)

a camera for capturing an image of an object to be inspected on a wafer;
a first determination unit that detects the inspection object from the image captured by the camera and makes a provisional determination of pass/fail of the inspection object;
a three-dimensional shape measuring machine for measuring a three-dimensional shape of the inspection object determined to be abnormal by the provisional determination;
a second judgment unit that performs a main judgment of pass/fail of the inspection object based on the three-dimensional shape of the inspection object measured by the three-dimensional shape measuring machine, the image captured by the camera, or the three-dimensional shape of the inspection object measured by the three-dimensional shape measuring machine;
An inspection device comprising: The inspection device according to claim 1, wherein the inspection object is a needle mark formed on an electrode pad of the wafer when the wafer is electrically inspected using a test head. The inspection device according to claim 2, wherein the first judgment unit detects the area of the needle mark formed on the electrode pad from the image captured by the camera and makes a provisional judgment of the quality of the electrode pad based on the area. The inspection device according to claim 2 or 3, wherein the second judgment unit performs a final judgment of the quality of the electrode pad based on the maximum valley depth of the electrode pad measured by the three-dimensional shape measuring device. The inspection device according to any one of claims 1 to 3, further comprising an alignment unit that acquires the positional relationship between the camera and the three-dimensional shape measuring device. The inspection device according to claim 5, wherein the alignment unit acquires the positional relationship between the camera and the three-dimensional shape measuring machine based on the measurement results of the alignment mark by the camera and the three-dimensional shape measuring machine. taking an image of an object to be inspected on a wafer by a camera, detecting the object to be inspected from the image, and provisionally determining whether the object to be inspected is good or bad;
measuring a three-dimensional shape of the inspection object determined to be abnormal by the provisional determination using a three-dimensional shape measuring machine, and making a final determination of pass/fail of the inspection object based on the three-dimensional shape of the inspection object measured by the three-dimensional shape measuring machine, the image captured by the camera, or the three-dimensional shape of the inspection object measured by the three-dimensional shape measuring machine;
An inspection method comprising: The inspection method according to claim 7, wherein the inspection object is a needle mark formed on an electrode pad of the wafer when the wafer is electrically inspected using a test head. The inspection method according to claim 7 or 8, further comprising an alignment step for acquiring the positional relationship between the camera and the three-dimensional shape measuring device. measuring an alignment mark with the camera;
measuring the alignment mark by the three-dimensional shape measuring machine;
10. The inspection method according to claim 9, wherein in the alignment step, a positional relationship between the camera and the three-dimensional shape measuring machine is acquired based on a measurement result of the alignment mark by the camera and the three-dimensional shape measuring machine.

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