Inspection device and inspection method

Abstract

Provided are an inspection device and an inspection method capable of accurately and quickly inspecting the appearance of a wafer. An inspection device (1, 1A, 1B) is provided with: a camera (50) that captures an image of an object to be inspected on a wafer; a first determination unit (10) that detects the object to be inspected on the basis of the image captured by the camera and temporarily determines the quality of the object to be inspected; a three-dimensional shape measuring device (52) that measures the three-dimensional shape of the object to be inspected that has been determined to be abnormal by the temporary determination; and a second determination unit (10) that performs a formal determination of the quality of the object to be inspected on the basis of the three-dimensional shape of the object to be inspected measured by the three-dimensional shape measurement machine and the image captured by the camera, or on the basis of the three-dimensional shape of the object to be inspected measured by the three-dimensional shape measurement machine.

Description

Technical Field

[0001] The present invention relates to an inspection apparatus and an inspection method, and more particularly to a technique for inspecting semiconductor devices formed on a semiconductor wafer. Background Art

[0002] In the manufacturing process of semiconductor devices, various inspections are carried out using various manufacturing processes in order to ensure quality and improve the yield. For example, in wafer-level inspection, at the stage where a plurality of chips corresponding to each semiconductor device are formed on a semiconductor wafer (hereinafter referred to as a wafer), the probes of a probe card are brought into contact with the electrode pads of the semiconductor device, and a test signal is supplied. Then, the tester measures the signal output by the semiconductor device according to the test signal, and electrically inspects whether the semiconductor device operates normally.

[0003] In the above-described wafer-level inspection, ideally, the probe only scrapes off the oxide film on the surface of the electrode pad, and the probe is brought into contact with the electrode pad to establish conduction. In wafer-level inspection, an over-drive is applied to scrape off the oxide film on the surface of the electrode pad using the probe. Also, by visually inspecting the wafer, the traces formed on the electrode pads are detected after the wafer-level inspection.

[0004] In the detection of traces after wafer-level inspection, when no trace is detected from the electrode pad, it is determined that the measurement is defective. On the other hand, when the probe penetrates the electrode pad and the base layer of the electrode pad is exposed, that electrode pad is treated as defective.

[0005] In Patent Document 1, a trace inspection apparatus is disclosed, which is used to automatically detect the exposure state of the base layer of the electrode pad after inspection using a probe. In Patent Document 1, a camera is used to photograph the traces formed on the electrode pad to check whether the base layer of the electrode pad is exposed.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2009-289818

[0009] Patent Document 2: Japanese Unexamined Patent Application Publication No. 2022-133631 Summary of the Invention

[0010] Problems to be Solved by the Invention

[0011] However, in the visual inspection of the wafer, sometimes based on the image of the wafer (two-dimensional image) captured by the camera, for example, in addition to the above-mentioned traces, inspections for the presence or absence of damage (e.g., damage on a plain or mirror-finished wafer without a formed pattern) or foreign objects are also carried out.

[0012] In the detection of stitches, for example, after wafer-level inspection in the visual inspection of wafers, as in Patent Document 1, the wafer is illuminated by an illumination unit after wafer-level inspection, and an image (two-dimensional image) of the upper surface of the wafer is captured using a camera. Further, the electrode pads and the base layer are distinguished based on the light and dark of the image.

[0013] In the case of distinguishing the electrode pads and the base layer based on the light and dark of the image as described above, it is sometimes difficult to determine whether the light and dark of the image are caused by the irradiation condition of light based on the shape of the wafer surface or by the difference in materials. For example, in the case where the proportion of the dark part caused by the shape of the wafer surface is large, it may sometimes be determined that the electrode pads are defective even when there is no exposure of the base layer.

[0014] In addition, also in the visual inspection of the wafer targeting defects or foreign matters or the like using a two-dimensional image, it may sometimes not be possible to obtain sufficient accuracy for determining the quality of the results of the visual inspection depending on the material of the wafer or the shape or type of the defect or foreign matter.

[0015] Therefore, it is considered to use a three-dimensional shape measuring machine capable of non-contact measurement of the three-dimensional shape of an object to be inspected to measure the three-dimensional shape of the stitches. For example, Patent Document 2 discloses a particle measuring device that uses a three-dimensional shape measuring machine to calculate the particle generation amount of particles generated when a probe touches an electrode pad based on the volume difference between the volume of the concave portion recessed from the reference surface of the electrode pad and the volume of the convex portion protruding from the reference surface of the electrode pad.

[0016] However, the measurement of the three-dimensional shape of the electrode pads based on the three-dimensional shape measuring machine takes time. For example, it takes more than a few days to complete the inspection of a batch of objects to be inspected, and the manufacturing efficiency of semiconductor devices (chips) is reduced.

[0017] In addition, in the case where the wafer after wafer-level inspection is placed on a pedestal for the above-described visual inspection, air disturbance sometimes occurs due to temperature unevenness. Such air disturbance may cause a reduction in the measurement accuracy by the three-dimensional shape measuring machine. For example, in the case of using a white light interference microscope as the three-dimensional shape measuring machine, the interference lens is easily affected by temperature. The reduction in inspection accuracy caused by external disturbances such as air disturbance as described above and the increase in the required inspection time caused by waiting for the external disturbance to subside are in a trade-off relationship.

[0018] The present invention has been made in view of such circumstances, and an object thereof is to provide an inspection device and an inspection method capable of accurately and quickly performing a visual inspection of a wafer.

[0019] Solution to the problem

[0020] The first solution of the present invention relates to an inspection device, which includes: a camera that captures an image of an object to be inspected on a wafer; a first determination unit that detects the object to be inspected based on the image captured by the camera and makes a provisional determination of the quality of the object to be inspected; a three-dimensional shape measuring machine that measures the three-dimensional shape of the object to be inspected determined to be abnormal through the provisional determination; and a second determination unit that makes a formal determination of the quality of the object to be inspected 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 based on the three-dimensional shape of the object to be inspected measured by the three-dimensional shape measuring machine.

[0021] According to the first solution, it is possible to perform a provisional determination of the quality of the electrode pads using the camera, which can be implemented at high speed, prior to the formal determination of the quality based on the three-dimensional shape measuring machine, and narrow down the scope of the object of the formal determination. As a result, it is possible to accurately inspect the traces formed on the surface of the electrode pads through wafer-level inspection using the three-dimensional shape measuring machine, and it is possible to shorten the time required for the quality determination.

[0022] Regarding the inspection device according to the second solution of the present invention, the object to be inspected according to the first solution is the traces formed on the electrode pads of the wafer when the wafer is electrically inspected using a test head.

[0023] In the inspection device according to the third solution of the present invention, in the second solution, the first determination unit detects the area of the traces formed on the electrode pads based on the image captured by the camera, and makes a provisional determination of the quality of the electrode pads based on the area.

[0024] In the inspection device according to the fourth solution of the present invention, in the second or third solution, the second determination unit makes a formal determination of the quality of the electrode pads based on the maximum valley depth of the electrode pads measured by the three-dimensional shape measuring machine.

[0025] In the inspection device according to the fifth solution of the present invention, in any one of the first to fourth solutions, the inspection device includes an alignment unit that obtains the positional relationship between the camera and the three-dimensional shape measuring machine.

[0026] In the inspection device according to the sixth solution of the present invention, in the fifth solution, the alignment unit obtains the positional relationship between the camera and the three-dimensional shape measuring machine based on the measurement results of the alignment marks measured by the camera and the three-dimensional shape measuring machine.

[0027] The seventh aspect of the present invention relates to an inspection method, which includes the following steps: taking an image of an object to be inspected on a wafer by a camera, detecting the object to be inspected based on the image, and temporarily determining the quality of the object to be inspected; and measuring the three-dimensional shape of the object to be inspected determined to be abnormal by the temporary determination by a three-dimensional shape measuring machine, and making a formal determination of the quality of the object to be inspected 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 based on the three-dimensional shape of the object to be inspected measured by the three-dimensional shape measuring machine.

[0028] Regarding the inspection method according to the eighth aspect of the present invention, the object to be inspected according to the seventh aspect is the stitch of the electrode pad formed on the wafer when the wafer is electrically inspected using a test head.

[0029] The inspection method according to the ninth aspect of the present invention, in the seventh or eighth aspect, the inspection method includes an alignment step in which the positional relationship between the camera and the three-dimensional shape measuring machine is obtained.

[0030] The inspection method according to the tenth aspect of the present invention, in the ninth aspect, the inspection method includes the following steps: measuring an alignment mark by the camera; and measuring the alignment mark by the three-dimensional shape measuring machine, and in the alignment step, obtaining the positional relationship between the camera and the three-dimensional shape measuring machine based on the measurement results of the alignment mark measured by the camera and the three-dimensional shape measuring machine.

[0031] The eleventh aspect of the present invention relates to an inspection apparatus, which includes: a three-dimensional shape measuring machine that measures the three-dimensional shape of an object to be inspected on a wafer; and a calculation unit that calculates the measurement cost required for measuring the object to be inspected on the wafer based on the object configuration information related to the configuration of the object to be inspected and the size of the measurement field of view of the three-dimensional shape measuring machine.

[0032] According to the eleventh aspect, by appropriately setting the size of the measurement field of view of the three-dimensional shape measuring machine, it is possible to accurately and quickly inspect the stitches formed by wafer-level inspection.

[0033] The inspection apparatus according to the twelfth aspect of the present invention, in the eleventh aspect, the inspection apparatus includes a selection unit that outputs the measurement cost calculated by the calculation unit and selects the size of the measurement field of view when inspecting the object to be inspected according to the operation input from the operator.

[0034] The inspection apparatus according to the thirteenth aspect of the present invention, in the eleventh aspect, the calculation unit calculates the measurement cost for each size of the measurement field of view based on the object configuration information and selects the size of the measurement field of view whose measurement cost satisfies the set criterion.

[0035] In any of the eleventh to thirteenth aspects of the inspection apparatus according to the fourteenth aspect of the present invention, the measurement cost includes information related to the scanning speed when scanning the wafer and the three-dimensional shape measuring machine in the height direction. The narrower the measurement field of view of the three-dimensional shape measuring machine, the greater the calculated value of the scanning speed by the calculation unit.

[0036] In any of the eleventh to fourteenth aspects of the inspection apparatus according to the fifteenth aspect of the present invention, the measurement cost includes information related to the measurement time required for measuring the inspection object on the wafer. The narrower the measurement field of view of the three-dimensional shape measuring machine, or the more the number of inspection objects that can be included in the measurement field of view, the smaller the calculated value of the measurement time by the calculation unit.

[0037] In any of the eleventh to fifteenth aspects of the inspection apparatus according to the sixteenth aspect of the present invention, the inspection apparatus includes a measurement field of view moving unit that moves the measurement field of view when inspecting the inspection object formed on the wafer so that the inspected inspection object is not included in the measurement field of view.

[0038] Regarding the inspection apparatus according to the seventeenth aspect of the present invention, the inspection object according to any of the eleventh to sixteenth aspects is the stitch of the electrode pad formed on the wafer when the wafer is electrically inspected using a test head.

[0039] The eighteenth aspect of the present invention relates to an inspection method, which includes the following steps: calculating the measurement cost required for measuring the inspection object on the wafer based on the inspection object configuration information related to the configuration of the inspection object on the wafer and the size of the measurement field of view of the three-dimensional shape measuring machine; and setting the calculated size of the measurement field of view for the three-dimensional shape measuring machine.

[0040] The nineteenth aspect of the present invention relates to an inspection apparatus, which includes: a measurement unit having a measurement chamber surrounded by a partition for separating the internal and external air environments; and a three-dimensional shape measuring machine that is detachable with respect to a first opening provided in the partition of the measurement unit and measures the three-dimensional shape of the inspection object of the wafer in the measurement chamber in a non-contact manner.

[0041] According to the nineteenth aspect, by surrounding the measurement chamber with a partition for separating the internal and external air environments, the influence of external interference on the inside of the measurement chamber can be minimized, and a decrease in the inspection accuracy of the three-dimensional shape of the inspection object caused by air disturbance can be suppressed.

[0042] Regarding the inspection apparatus according to the twentieth aspect of the present invention, the partition of the measurement chamber according to the nineteenth aspect has at least one of light-shielding properties and vibration-proof properties.

[0043] The inspection device according to the twenty-first aspect of the present invention is characterized in that in the nineteenth or twentieth aspect, the inspection device includes a first shutter provided at a second opening provided in a wall adjacent to the measurement unit, and the wafer is carried in and out of the measurement chamber through the second opening.

[0044] The inspection device according to the twenty-second aspect of the present invention is any one of the nineteenth to twenty-first aspects, wherein the inspection device includes a cover that covers the three-dimensional shape measuring device when the three-dimensional shape measuring device is attached to the measuring unit and is used to separate the internal and external air environments.

[0045] In the inspection device according to the twenty-third aspect of the present invention, the cover according to the twenty-second aspect has at least one of a light shielding property and a vibration-proof property.

[0046] The inspection device according to the twenty-fourth aspect of the present invention is any one of the nineteenth to twenty-first aspects, wherein the inspection device includes a transparent member that can be attached to the first opening, and the three-dimensional shape measuring machine measures the inspection object in the measurement chamber through the transparent member.

[0047] The inspection device involved in the twenty-fifth embodiment of the present invention is any one of the nineteenth to twenty-fourth embodiments, and the inspection device comprises: a fan, which is installed on the third opening and is used to circulate air in the measurement chamber, and the third opening is arranged next to the measurement unit; and a baffle for the fan, which is used to open and close the third opening.

[0048] The inspection device involved in the twenty-sixth embodiment of the present invention is any one of the nineteenth to twenty-fifth embodiments, and the inspection device comprises: a loading section, which has a preparation room surrounded by a partition for separating the inside and outside air environments; and a second baffle, which is arranged at an opening arranged in the partition of the loading section, and the wafer is moved in and out of the preparation room via the opening of the loading section.

[0049] In the inspection device according to the twenty-seventh aspect of the present invention, the partition wall of the preparation room according to the twenty-sixth aspect has at least one of a light shielding property and a vibration-proof property.

[0050] The inspection device involved in the twenty-eighth embodiment of the present invention is any one of the nineteenth to twenty-seventh embodiments, wherein the inspection device comprises a test head which can be loaded and unloaded relative to the first opening of the measuring unit, and the inspection object is a needle trace formed on the electrode pad when the wafer is electrically inspected using the test head.

[0051] In the twenty-ninth aspect of the present invention, the inspection device includes: a first mounting portion formed on the partition wall of the measurement unit; a second mounting portion formed on the test head and shaped to be mountable on the first mounting portion; and a third mounting portion formed on the three-dimensional shape measuring machine and shaped to be mountable on the first mounting portion.

[0052] Regarding the inspection device according to the thirtieth aspect of the present invention, the second mounting portion and the third mounting portion according to the twenty-ninth aspect are shaped to be fitted into the first mounting portion.

[0053] Advantageous Effects of Invention

[0054] According to the present invention, it is possible to accurately inspect the stitches formed on the surface of the electrode pads through wafer-level inspection by using a three-dimensional shape measuring machine, and it is possible to shorten the time required for inspection. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 FIG. is a view showing the inspection device according to the first embodiment of the present invention (during wafer-level inspection).

[0056] Figure 2 FIG. is a view showing the inspection device according to the first embodiment of the present invention (during inspection of electrode pads).

[0057] Figure 3 FIG. is a block diagram showing the control system of the inspection device according to the first embodiment of the present invention.

[0058] Figure 4 FIG. is a flowchart showing the inspection method according to the first embodiment of the present invention.

[0059] Figure 5 FIG. is an example of a captured image of an electrode pad captured by a 2D camera.

[0060] Figure 6 FIG. is an example of measurement data obtained by measuring an electrode pad to be officially determined by a three-dimensional shape measuring machine.

[0061] Figure 7 FIG. is a view for explaining the characteristic amount (maximum valley depth) of the stitches formed on the electrode pads.

[0062] Figure 8 FIG. is a flowchart showing the inspection method according to a modification of the first embodiment.

[0063] Figure 9 FIG. is a flowchart showing the inspection method according to a modification of the first embodiment (continued Figure 8 )

[0064] Figure 10 This is a diagram showing the inspection apparatus according to the second embodiment of the present invention (during wafer-level inspection).

[0065] Figure 11 This is a plan view and a front view showing an example of an alignment mark.

[0066] Figure 12 This is a flowchart showing the order of alignment between a 2D camera and a 3D shape measurement machine.

[0067] Figure 13 This is a diagram showing an example of a captured image of an alignment mark.

[0068] Figure 14 This is a plan view for explaining the positional relationship between a 2D camera and a 3D shape measurement machine.

[0069] Figure 15 This is a plan view for explaining the positional relationship between a 2D camera and a 3D shape measurement machine.

[0070] Figure 16 This is a diagram showing the inspection apparatus according to the third embodiment of the present invention (during wafer-level inspection).

[0071] Figure 17 This is a flowchart showing the order of alignment between a 2D camera and a 3D shape measurement machine.

[0072] Figure 18 This is a block diagram showing an example of a 2D camera.

[0073] Figure 19 This is a diagram showing an example of the field of view of a 2D camera and the spot of a light beam.

[0074] Figure 20 This is a diagram showing the inspection apparatus according to the fourth embodiment of the present invention (during wafer-level inspection).

[0075] Figure 21 This is a diagram showing the inspection apparatus according to the fourth embodiment of the present invention (during inspection of electrode pads).

[0076] Figure 22 This is a block diagram showing the control system of the inspection apparatus according to the fourth embodiment of the present invention.

[0077] Figure 23 This is a plan view of a wafer.

[0078] Figure 24 This is a plan view showing an enlarged view of the chip ( Figure 23 in the region XXIV).

[0079] Figure 25A table showing examples of the measurement times of electrode pads.

[0080] Figure 26 A block diagram showing the function of setting the scanning speed in the Z direction between the 3D shape measuring machine and the wafer.

[0081] Figure 27 A block diagram showing the function of setting the size of the measurement field of view of the 3D shape measuring machine.

[0082] Figure 28 A diagram for explaining the measurement order of electrode pads.

[0083] Figure 29 A diagram for explaining the characteristic quantity (maximum valley depth) of the stitch M formed on the electrode pad.

[0084] Figure 30 A diagram showing the inspection device according to the fifth embodiment of the present invention (during wafer-level inspection).

[0085] Figure 31 A diagram showing the inspection device according to the fifth embodiment of the present invention (during inspection of electrode pads).

[0086] Figure 32 A block diagram showing the control system of the inspection device according to the fifth embodiment of the present invention.

[0087] Figure 33 A diagram showing the inspection device according to the first modification of the fifth embodiment (during wafer-level inspection).

[0088] Figure 34 A diagram showing the inspection device according to the second modification of the fifth embodiment (during wafer-level inspection).

[0089] Figure 35 A diagram showing the test head and the 3D shape measuring machine in the inspection device according to the third modification of the fifth embodiment.

[0090] Figure 36 A flowchart showing the inspection method according to the fifth embodiment of the present invention. Detailed Embodiments

[0091] Hereinafter, embodiments of the inspection device and the inspection method will be described with reference to the drawings.

[0092] [First Embodiment]

[0093] In the present embodiment, as an example of the appearance inspection of a wafer, a case where the detection of the traces of the electrode pads P formed on the wafer W after wafer-level inspection is described, but the present disclosure is not limited thereto. For example, the present embodiment can also be applied to the measurement (detection) of any inspection object (e.g., scratches or foreign substances, etc.) on the wafer W.

[0094] Figure 1 and Figure 2 FIG. is a diagram showing an inspection apparatus according to a first embodiment of the present invention. Figure 2 shows a state during the implementation of wafer-level inspection, Figure 1 shows a state during the inspection (detection of traces) of the electrode pads P of the wafer W after wafer-level inspection.

[0095] When implementing wafer-level inspection, as Figure 2 shown, the test head 70 is mounted on the housing of the measurement unit 100 of the inspection apparatus 1. Next, the probes 74 of the probe card 72 are brought into contact with the electrode pads P formed on the surface of the inspection target wafer W to supply a test signal. Then, the tester measures the signal output by the semiconductor device (chip C) according to the test signal, and electrically inspects whether the semiconductor device operates normally. In wafer-level inspection, a part of the oxide film on the surface of the electrode pad P is scraped off by the probe 74, so that the probe 74 is electrically connected to the electrode pad P.

[0096] When inspecting the electrode pads P of the wafer W, as Figure 1 shown, a three-dimensional shape measuring machine (hereinafter referred to as a 3D shape measuring machine.) 52 is mounted on the measurement unit 100 of the inspection apparatus 1.

[0097] In the inspection of the electrode pads P of the wafer W, first, a preliminary determination is made using a 2D camera (e.g., an imaging unit for aligning the wafer W) 50. In the preliminary determination, the electrode pads P are photographed by the 2D camera 50. Then, the traces formed on the electrode pads P during wafer-level inspection are detected based on the image photographed by the 2D camera 50, and the quality (OK / NG) of the detected traces is determined. In the determination of the quality of the traces using the image photographed by the 2D camera 50, the quality of the traces is determined based on a feature amount (a first feature amount. For example, area) related to the traces. Specifically, it is considered that when the area of the traces in the electrode pad P exceeds a preliminary determination threshold (a first threshold), the possibility of deeply digging out the traces is high, and the possibility of exposing the base layer is high. Therefore, when the area of the traces in the electrode pad P exceeds the preliminary determination threshold (the first threshold), the electrode pad P is preliminarily determined to be abnormal (NG: no good).

[0098] Next, regarding the electrode pad P determined to be NG in the provisional determination, the 3D shape measuring machine 52 is used to determine the quality (OK / NG) of the stitch (formal determination).

[0099] 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 measuring method in the 3D shape measuring machine 52 is not particularly limited, and for example, the white light interference method, SD-OCT method (Spectral Domain Optical Coherence Tomography), FD-OCT method (Fourier Domain Optical Coherence Tomography), laser confocal point method, triangulation method, light cutting method, pattern projection method, optical comb method (Optical Comb), and focus variation method can be applied. In addition, as the 3D shape measuring machine 52 using the white light interference method, for example, the techniques described in Japanese Unexamined Patent Application Publication No. 2016-080564 or Japanese Unexamined Patent Application Publication No. 2016-161312 can be applied.

[0100] In the determination of the quality of the stitch using the 3D shape measuring machine 52, only the electrode pad P determined to be NG in the provisional determination is set as the object of the formal determination. Moreover, regarding the electrode pad P that is the object of the formal determination, the 3D shape measuring machine 52 is used to measure its shape, and the characteristic quantity of the electrode pad P (second characteristic quantity. For example, the maximum valley depth Sv of the stitch formed on 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. When the maximum valley depth Sv exceeds the formal determination threshold (second threshold), the base layer is exposed due to the stitch, and it is determined to be abnormal (NG) because the possibility of damaging the circuit is high.

[0101] According to the present embodiment, by using the 3D shape measuring machine 52, it is possible to accurately inspect the stitches formed through wafer-level inspection. In addition, in the present embodiment, the quality determination using the 2D camera 50 that can be performed at high speed is performed prior to the quality determination based on the 3D shape measuring machine 52, and the range of the object of the formal determination is narrowed down, so that the time required for the quality determination can be shortened.

[0102] (Structure of the inspection device)

[0103] As Figure 1 and Figure 2As shown, the inspection apparatus 1 according to this embodiment includes a measurement unit 100 and a loading unit 200 that supplies the wafer W to be inspected to the measurement unit 100 and retrieves the wafer W to be inspected. The measurement unit 100 and the loading unit 200 can be separated. It should be noted that multiple measurement units 100 and loading units 200 can be provided, but for simplicity of explanation, only one of each is shown separately.

[0104] The loading unit 200 has a loading port for placing a wafer cassette and a transfer unit 202 that transfers the wafer W between each measurement unit 100 of the measurement unit 100 and the wafer cassette (see Figure 3 ).

[0105] When the wafer W is supplied from the loading unit 200 to each measurement unit 100, the wafer W is adsorbed and held by the holding surface of the pedestal ST of each measurement unit 100.

[0106] The pedestal moving mechanism 102 supports the lower surface of the pedestal ST (the surface opposite to the holding surface on which the wafer W is adsorbed and held). The pedestal moving mechanism 102 is configured to be able to move in the XYZ directions and to be able to rotate in the θ direction (the rotation direction around the Z direction). Thus, the wafer W adsorbed and held by the holding surface of the pedestal ST can move in the XYZ directions and rotate in the θ direction integrally with the pedestal ST by the pedestal moving mechanism 102.

[0107] As Figure 2 shown, during wafer-level inspection, the test head 70 is mounted on the measurement unit 100 of the inspection apparatus 1.

[0108] The probe card 72 is provided at a position facing the pedestal ST and is arranged substantially parallel to the holding surface of the pedestal ST. A plurality of probes 74 are formed on the surface of the probe card 72 facing the pedestal ST. The probe card 72 is connected to the tester main body via the test head 70.

[0109] A plurality of chips C are formed on the wafer W, and each chip C has one or more electrode pads P. By moving the pedestal ST in the XYZ directions or rotating it in the θ direction by the pedestal moving mechanism 102, the alignment between the wafer W and the probe card 72 is performed so that each probe 74 touches the corresponding electrode pad P.

[0110] After the alignment and contact between the probe 74 and the electrode pad P are performed by the inspection apparatus 1, an electrical signal is sent from the tester main body to the chip C via the test head 70, the probe card 72, and the probe 74, and the electrical characteristics of the chip C on the wafer W are inspected (wafer-level inspection). The inspection result of the electrical characteristics is output in a form that can be confirmed by the operator through the input / output unit (see Figure 3 ).

[0111] After the inspection of the electrical characteristics of the chip C on the wafer W is completed, the wafer W is transported from the inspection apparatus 1 to the loading unit 200 by the transfer unit and recovered.

[0112] As Figure 1 shown, when inspecting the electrode pads P of the wafer W, the 3D shape measuring machine 52 is attached to the measuring unit 100 of the inspection apparatus 1. Then, the 2D camera 50 and the 3D shape measuring machine 52 sequentially detect the traces formed on the electrode pads P in the wafer-level inspection, and determine the quality of the traces formed on the electrode pads P.

[0113] Note that, in the present embodiment, the positional relationship between the 2D camera 50 and the 3D shape measuring machine 52 is set to be known or calibrated.

[0114] In addition, in the present embodiment, the 2D camera 50 and the 3D shape measuring machine 52 are separately attached, but it is not limited thereto. For example, it may be configured such that the 2D camera 50 and the 3D shape measuring machine 52 can be switched by a revolver mechanism.

[0115] In addition, in the present embodiment, the test head 70 and the 3D shape measuring machine 52 can be attached to and detached from the measuring unit 100 of the inspection apparatus 1, but it is not limited thereto. For example, the wafer-level inspection and the inspection of the electrode pads P after the wafer-level inspection may also be performed by a separate apparatus.

[0116] In addition, it is sufficient that the test head 70, the 2D camera 50, the 3D shape measuring machine 52, etc. can move relative to the pedestal ST, and it may be configured such that the test head 70, the 2D camera 50, the 3D shape measuring machine 52, etc. can move relative to the pedestal ST.

[0117] (Control System of Inspection Apparatus)

[0118] Figure 3 is a block diagram showing the control system of the inspection apparatus according to the first embodiment of the present invention.

[0119] As Figure 3 shown, the inspection apparatus 1 according to the present embodiment includes a control unit 10, an input / output unit 12, a transfer unit drive unit 14, a transfer arm drive unit 16, and a measurement control unit 18.

[0120] The control unit 10 includes a processor (e.g., CPU (Central Processing Unit), MPU (MicroProcessor Unit), etc.), ROM (Read Only Memory), RAM (Random Access Memory), and a memory device (e.g., HDD (Hard Disk Drive) or SSD (Solid State Drive), etc.). In the control unit 10, various programs such as a control program stored in the memory device are executed by the processor to implement the functions of the respective parts of the inspection device 1. The control unit 10 is an example of the first determination unit and the second determination unit.

[0121] The input / output unit 12 includes a display unit (e.g., a liquid crystal display) for displaying a GUI (Graphical User Interface) or the like for operating the inspection device 1, and an operation unit (e.g., a touch panel, a keyboard, a pointing device, etc.) for receiving an operation input from the user.

[0122] The transfer unit drive unit 14 includes a motor or the like for moving the transfer unit 202 in the XYZ directions and rotating it in the θ direction (around the Z direction) within the loading unit 200.

[0123] The transfer arm drive unit 16 includes a motor for extending and retracting the transfer arm 204 mounted on the transfer unit 202 in its longitudinal direction, and a control valve or the like for adsorbing the wafer W to the adsorption holes of the transfer arm 204. This control valve is connected to a vacuum component (pump) provided at the installation site of the inspection device 1.

[0124] The control unit 10 controls the transfer unit 202 and the transfer arm 204 respectively using the transfer unit drive unit 14 and the transfer arm drive unit 16 to take out the wafer W from a plurality of wafer cassettes, or to carry the wafer W into and out of a plurality of measurement units 100.

[0125] The alignment camera 54 is a device for detecting the front-end position of the probe 74, and is provided, for example, on the pedestal ST. The control unit 10 performs alignment between the probe 74 and the electrode pad P based on the detection result of the front-end position of the probe 74 and the detection result of the electrode pad P detected by the 2D camera 50.

[0126] The measurement control unit 18 performs drive control of the test head 70 for inspecting the wafer W provided in the measurement unit 100, shooting control of the 2D camera 50, measurement control of the 3D shape measuring machine 52, and shooting control of the alignment camera 54 in accordance with the control signal from the control unit 10. It should be noted that, as the test head 70 and the 2D camera 50, for example, the techniques described in Japanese Unexamined Patent Application Publication No. 2019-102591 can be used.

[0127] (Inspection Method)

[0128] Figure 4 It is a flowchart showing the inspection method according to the first embodiment of the present invention.

[0129] When starting the inspection of a batch of wafers W, the parameter i of the number of wafers W to be inspected is set to i = 1 (step S10). Then, the first wafer W1 is loaded onto the pedestal ST (step S12), and wafer-level inspection of the wafer W1 is performed (step S14).

[0130] After the wafer-level inspection, the quality determination of the electrode pads P is performed using the 2D camera 50 and the 3D shape measuring machine 52 (steps S16 and S18).

[0131] In step S16, the quality determination of the electrode pads P is performed using the 2D camera 50. The detection of the electrode pads P using the 2D camera 50 can be performed in a shorter time compared to the case of using the 3D shape measuring machine 52. Therefore, in step S16, all the electrode pads P of the wafer W1 can also be set as the inspection objects.

[0132] Figure 5 It is a diagram showing an example of a captured image IMG of the electrode pads P captured by the 2D camera 50.

[0133] In step S16, first, the electrode pads P are detected. As Figure 5 shown, the reflectance of light on the surface of the wafer W (for example, silicon) is different from the reflectance of light on the surface of the electrode pads P (for example, aluminum), so the brightness in the captured image IMG is different. 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 brightness difference in the captured image IMG. It should be noted that the electrode pads P can also be detected based on the design values of the shape, size, or configuration of the electrode pads P in addition to the brightness difference in the captured image IMG.

[0134] Next, the traces formed on the electrode pads P are detected based on the captured image captured by the 2D camera 50. As Figure 5As shown, the stitch M is the part of the electrode pad P dug out by the probe 74. Therefore, light is scattered at the stitch M and it is difficult for the light to reach the 2D camera 50 side. Therefore, the stitch M is darker than the part of the electrode pad P other than the stitch M. The control unit 10 detects the area of the electrode pad P that is darker than the surrounding area in the captured image IMG as the stitch M.

[0135] It should be noted that the order of detecting the electrode pad P and the stitch M is not particularly limited, and they can be performed sequentially or simultaneously.

[0136] Next, the control unit 10 calculates the first feature amount based on the detection result of the stitch M, and makes a provisional determination of the quality of the stitch M. As the first feature amount, for example, the area of the stitch M can be used. When the area of the stitch M detected from the captured image IMG exceeds the provisional determination threshold (the first threshold), the possibility that the stitch is deeply dug is high and the possibility that the base layer is exposed is high. Therefore, the electrode pad P is provisionally determined as abnormal (NG).

[0137] Here, the quality of the stitch M is sometimes affected by the movement amount (dragged distance) of the probe 74 in the electrode pad P, etc. Therefore, the provisional determination threshold (the first threshold) related to the area of the stitch M can also be set to a value approximately equal to the thickness of the probe 74 or the cross-sectional area in the XY plane, for example, based on the thickness of the probe 74. In this case, the conditions for being NG in the provisional determination can be made strict, and the inspection accuracy can be improved.

[0138] It should be noted that the provisional determination is not limited to the above examples. For example, the provisional determination can also be made based on the thickness of the electrode pad P, the ratio of the area of the stitch M to the electrode pad P, the position, or the strength (brittleness) of the material of the electrode pad P. For example, it is considered that the thicker the electrode pad P is, the less likely the base layer is to be exposed. Therefore, the provisional determination threshold (the first threshold) related to the area of the stitch M can also be increased. In addition, it is considered that the lower the strength (the more brittle) the material of the electrode pad P is, the higher the possibility that the electrode pad P will crack, etc. Therefore, the provisional determination threshold (the first threshold) related to the area of the stitch M can also be decreased.

[0139] In addition, it is considered that when the ratio of the area of the stitch M to the electrode pad P is above the reference value, when the part of the electrode pad P other than the stitch M is below the reference value, when the distance between the end of the electrode pad P and the stitch M is below the reference value, etc., the possibility that the electrode pad P will crack, etc. is high. Therefore, it can also be provisionally determined as abnormal (NG). In this case, the reference values can also be adjusted according to the strength of the material of the electrode pad P. For example, the lower (the more brittle) the strength of the electrode pad P is, the stricter the reference for the provisional determination of being abnormal (NG) is.

[0140] Next, the 3D shape measuring machine 52 is used to perform a determination of superiority and inferiority (formal determination) (step S18) on the electrode pads P that failed the provisional determination (step S16).

[0141] Figure 6 It is a diagram showing an example of measurement data obtained by measuring the electrode pad P that is the object of the formal determination with the 3D shape measuring machine 52. In Figure 6 it, the three-dimensional coordinates measured by the 3D shape measuring machine 52 are shown three-dimensionally by light and shade.

[0142] In step S18, first, the three-dimensional shape of the region including the electrode pads P that failed the provisional determination is measured. In the present 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 captured image IMG captured by the 2D camera 50, the 3D shape measuring machine 52 can be used to measure the region including the electrode pads P that failed the provisional determination.

[0143] As Figure 6 shown, the measurement data R1 measured by the 3D shape measuring machine 52 includes the following measurement results, that is, the measurement results of the three-dimensional coordinates (XYZ coordinates) of each position in the region including the electrode pads P that are the objects of the formal determination and failed the provisional determination, and the measurement results of the three-dimensional coordinates of the region including, for example, the surface region Ws of the wafer W (chip C) between the electrode pads P that are the objects of the formal determination and the adjacent electrode pads.

[0144] The control unit 10 extracts the electrode pads P that are the objects of the formal determination from the measurement data R1. In the present embodiment, for example, based on the difference h between the height (Z coordinate) of the electrode pad P that is the object of the formal determination and the height (Z coordinate) of the surface region Ws of the wafer W (chip C) between the adjacent electrode pads, the electrode pad P is extracted. Specifically, the control unit 10 extracts the surface region of the electrode pad P, for example, by excluding the region with a low thickness amount from the height (Z coordinate) of the electrode pad P.

[0145] Next, the control unit 10 calculates a second feature amount related to the stitch M based on the measurement data R2 of the surface region of the extracted electrode pad P. In the present embodiment, the maximum valley depth Sv defined by JIS B 0681-2:2018 or ISO25178-2:2012 is used as the second feature amount.

[0146] Figure 26 It is a diagram for explaining the feature amount (maximum valley depth Sv) of the stitch M formed on the electrode pad P. In Figure 26In this case, a three-dimensional shape (concavity and convexity) of the surface of the electrode pad P is shown by a curve along the X direction.

[0147] The maximum valley depth Sv is the absolute value of the minimum value of the height with respect to the average plane Pm in which the height (Z coordinate) in the surface of the electrode pad P becomes an average value (arithmetic mean). It should be noted that, in Figure 26 Sp is the maximum peak height and is the maximum value with respect to the average plane Pm. In addition, Sz is the maximum height indicating the distance from the highest point to the lowest point of the surface of the electrode pad P, and Sz = Sp + Sv.

[0148] The control unit 10 performs a formal determination 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, when the maximum valley depth Sv is equal to or greater than the design value of the thickness of the electrode pad P, or 90% or more of the design value, the electrode pad P is determined to be NG.

[0149] It should be noted that the formal determination is not limited to the above example. For example, the formal determination threshold (second threshold) related to the maximum valley depth Sv can also be changed based on the thickness of the electrode pad P, the ratio of the area of the stitch M to the electrode pad P, the position, or the strength (brittleness) of the material of the electrode pad P. For example, it is considered that the thicker the electrode pad P, the less likely the base layer is to be exposed, so the formal determination threshold (second threshold) related to the maximum valley depth Sv can also be set to a value closer to the design value of the thickness of the electrode pad P. In addition, it is considered that the lower the strength (brittleness) of the material of the electrode pad P, the higher the possibility of cracking or the like in the electrode pad P, so the formal determination threshold (second threshold) related to the maximum valley depth Sv can also be set to a smaller value with respect to the design value of the thickness of the electrode pad P.

[0150] In addition, it is considered that in the case where the ratio of the area of the stitch M to the electrode pad P is equal to or greater than a reference value, the portion of the electrode pad P other than the stitch M is equal to or less than the reference value, the distance between the end of the electrode pad P and the stitch M is equal to or less than the reference value, etc., the possibility of cracking or the like in the electrode pad P is high, so it can also be determined to be NG. In this case, the reference values can also be adjusted according to the strength of the material of the electrode pad P. For example, the lower the strength (brittleness) of the electrode pad P, the stricter the reference for determining NG.

[0151] In addition, for example, when the area of the stitch M is used as the first feature quantity in the provisional determination, in the formal determination, a feature quantity such as the distance between the end of the electrode pad P and the stitch M being equal to or less than a reference value, and the second feature quantity (maximum valley depth Sv) measured by the 3D shape measuring machine 52 can also be used together.

[0152] When the wafer-level inspection (step S14) of the wafer W1 and the inspection of the electrode pads P (steps S16 and S18) are completed, the wafer W1 is unloaded from the pedestal ST (step S20). Then, as i = i + 1 (the "No" of step S22, step S24), the wafer-level inspection (step S14) of the next wafer W2 and the inspection of the electrode pads P (steps S16 and S18) are performed.

[0153] Steps S12 to S24 are repeatedly performed, and when the wafer-level inspection (step S14) of the wafers Wi in the lot to be inspected and the inspection of the electrode pads P (steps S16 and S18) are completed (the "Yes" of step S22), the inspection process is ended.

[0154] The 3D shape measuring machine 52 has the advantage of being able to obtain information in the Z direction. However, when compared with the 2D camera 50, one more axis is added, so the measurement speed becomes slower. For example, in the case of using a white light interference microscope or a device using the focus change method as the 3D shape measuring machine 52, a high NA (Numerical Aperture) lens with high sensitivity at the inclined surface is used to obtain the three-dimensional shape. Since the magnification of the high NA lens is large, the measurement field of view becomes narrow. Therefore, the area on the wafer W that can be measured by one scan becomes smaller. 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 Z-direction scans, so the measurement takes time. On the other hand, in the case of the 2D camera 50, there is no such restriction as in the case of the 3D shape measuring machine 52, so a lens with a large field of view can be used. In addition, in the case of the 2D camera 50, Z-direction scanning is not required, so the measurement can be performed at high speed.

[0155] According to the present embodiment, the determination of the quality of the electrode pads P using the 2D camera 50 that can be performed at high speed is performed prior to the determination of the quality based on the 3D shape measuring machine 52, and the range of the object of the official determination can be narrowed down. Thereby, the inspection of the stitches M formed on the surface of the electrode pads P through the wafer-level inspection can be accurately performed by the 3D shape measuring machine 52, and the time required for the quality determination can be shortened.

[0156] It should be noted that, in the present embodiment, the inspection object is the stitch M formed on the electrode pad P, but as described above, the present disclosure is not limited thereto. For example, the present embodiment can also be applied to the appearance inspection for detecting inspection objects such as scratches or foreign matters on the wafer W.

[0157] For example, when inspecting for defects on the wafer W, the wafer W may be determined to be abnormal when at least one characteristic quantity among the size of the defect (e.g., the maximum size or the minimum size), the depth of the defect (e.g., the maximum valley depth Sv or the maximum height Sz), the area of the defect (e.g., the ratio of the area of the defect to the area per unit of the wafer W), the configuration of the defects (e.g., the number per unit area, etc.) exceeds a reference value. Additionally, instead of or in addition to the above characteristic quantities, the wafer W may be determined to be abnormal when the distance between the defect and the device is below the reference value.

[0158] In addition, when the inspection object is a foreign object, for example, when at least one characteristic quantity among the size of the foreign object (e.g., the maximum size or the minimum size), the configuration of the foreign object (e.g., the number per unit area, etc.) exceeds a reference value, the wafer W may be determined to be abnormal. Additionally, instead of or in addition to the above characteristic quantities, the quality of the wafer W may be determined based on the type of the foreign object. For example, when it is presumed based on the three-dimensional shape of the foreign object that the foreign object is a foreign object that can be easily removed by air or the like, the wafer W may be determined to have no abnormality regardless of the above characteristic quantities.

[0159] [Modification Example of the First Embodiment]

[0160] It should be noted that in the first embodiment, the provisional determination using the 2D camera 50 and the formal determination using the 3D shape measurement machine 52 are performed sequentially for each wafer, but the inspection order of the wafer W is not limited to this. For example, the provisional determination using the 2D camera 50 may be initially performed for one lot, and then the formal determination using the 3D shape measurement machine 52 may be performed on the wafer W including the electrode pad P determined to be abnormal in the provisional determination.

[0161] Figure 8 and Figure 9 is a flowchart showing the inspection method according to the modification example of the first embodiment. Figure 8 is a flowchart of the provisional determination using the 2D camera 50, Figure 9 is a flowchart of the formal determination using the 3D shape measurement machine 52.

[0162] When starting the provisional determination of the lot of the wafer W, as Figure 8 shown, the parameter i of the number of wafers W to be inspected is set to i = 1 (step S50). Then, the first wafer W1 is loaded onto the pedestal ST (step S52), and the quality determination (provisional determination) of the electrode pad P is performed using the 2D camera 50 (step S54).

[0163] When the provisional determination (step S54) ends, the wafer W1 is unloaded from the pedestal ST (step S56). Then, as i = i + 1 (the "No" of step S58, step S60), a provisional determination is made for the next wafer W2 (step S54).

[0164] Steps S52 to S60 are repeatedly performed. When the provisional determination of the wafer Wi of the lot to be inspected (step S54) ends (the "Yes" of step S58), the provisional determination process ends.

[0165] Next, when the formal determination of the lot of wafers W starts, as Figure 9 shown, the parameter j of the number of wafers W to be inspected is set to j = 1 (step S70). Then, when the first wafer W1 does not include the electrode pads P that were abnormally determined in the provisional determination (the "No" of step S72), the object of the formal determination is changed as j = j + 1 (step S74).

[0166] On the other hand, when the first wafer W1 includes the electrode pads P that were abnormally determined in the provisional determination (the "Yes" of step S72), the wafer W1 is loaded onto the pedestal ST (step S76), and the quality determination (formal determination) of the electrode pads P is performed using the 3D shape measuring machine 52 (step S78).

[0167] When the formal determination (step S78) ends, the wafer W1 is unloaded from the pedestal ST (step S80). Then, as j = j + 1 (the "No" of step S82, step S74), a provisional determination is made for the next wafer W2 (steps S72 to S82).

[0168] Steps S72 to S82 are repeatedly performed. When the provisional determination of the wafer Wj of the lot to be inspected (steps S72 to S82) ends (the "Yes" of step S82), the formal determination process ends.

[0169] Also in the modified example, the quality determination of the electrode pads P using the 2D camera 50 is performed prior to the quality determination based on the 3D shape measuring machine 52, whereby the inspection of the stitches M formed on the surface of the electrode pads P can be accurately and rapidly performed.

[0170] It should be noted that Figure 8 and Figure 9 do not include the steps of wafer-level inspection and show the order in the case of performing the inspection of the electrode pads P after the wafer-level inspection. The present disclosure is not limited to this, Figure 8 and Figure 9 in the process of (for example, between step S52 and S54 of Figure 8 ) may also include wafer-level inspection.

[0171] [Second Embodiment]

[0172] In the first embodiment, it is premised that the positional relationship between the 2D camera 50 and the 3D shape measurement machine 52 is known or has been calibrated. In contrast, in the present embodiment, alignment (registration) between the 2D camera 50 and the 3D shape measurement machine 52 is performed.

[0173] That is, in the present embodiment, alignment between the 2D camera 50 and the 3D shape measurement machine 52 is performed by the control unit 10 after the wafer-level inspection (step S14) and before the inspection of the electrode pads P (steps S16 and S18). Here, the control unit 10 is an example of an alignment unit.

[0174] Figure 10 is a diagram showing the inspection apparatus according to the second embodiment of the present invention (during wafer-level inspection). As Figure 10 shown, in the inspection apparatus 1A according to the present embodiment, a sub-stage SST connected to the stage ST is provided, and alignment marks MA are formed on the sub-stage SST.

[0175] Figure 11 is a plan view and a front view showing an example of the alignment mark MA. In Figure 11 an example of three alignment marks MA is shown. It should be noted that Figure 11 the coordinate axes shown in the lower left of

[0176] As Figure 11 shown, the alignment mark MA according to the present embodiment is a cross shape formed by combining two orthogonal line segments in the XY plane view and has a step in the Z direction.

[0177] Here, it is preferable that the alignment mark MA and the sub-stage SST serving as the base have different materials.

[0178] In Figure 11 the example shown in (a) of Figure 11 the cross-shaped portion of the alignment mark MA protrudes from the surface of the sub-stage SST, and the cross-sectional shape of the protruding portion is a rectangle. On the other hand, in Figure 11 the example shown in (b) of Figure 11 the cross-shaped portion of the alignment mark MA is recessed from the surface of the sub-stage SST, and the cross-sectional shape of the recessed portion is a rectangle. It should be noted that in Figure 11 the cross-sectional shape of the recessed portion in (b) may also have rounded corners. In addition, in Figure 11 the example shown in (c) of Figure 11 the cross-shaped portion of the alignment mark MA protrudes from the surface of the sub-stage SST as in (a), but the front end shape of the protruding portion has rounded corners. Any of the examples can be applied to the alignment between the 2D camera 50 and the 3D shape measurement machine 52.

[0179] Note that, in the Figure 11 example shown, the shape of the alignment mark MA is set to a cross shape, but it is not limited thereto. The alignment mark MA may, for example, also be a shape having independent two-direction components, specifically, a rectangle, a rhombus, a triangle, an ellipse (e.g., an ellipse, an oblong, or an oval, etc.), or an L-shaped, etc. In addition, even if the alignment mark MA is circular and does not have independent two-direction components, since its center coordinates can be obtained and utilized, it can also be applied to the alignment between the 2D camera 50 and the 3D shape measuring machine 52 according to this embodiment.

[0180] Figure 12 is a flowchart showing the order (alignment steps) of the alignment between the 2D camera 50 and the 3D shape measuring machine 52.

[0181] First, move the sub pedestal SST under the 2D camera 50 and photograph the alignment mark MA (step S100). In step S100, the sub pedestal SST is moved under the 2D camera 50, for example, based on the design value of the position of the sub pedestal SST, etc.

[0182] Next, read the XY coordinates (Xs, Ys) of the pedestal ST and photograph the alignment mark MA using the 2D camera 50. Here, when the 2D camera 50 is a color camera, it may be converted into a grayscale image.

[0183] Figure 13 is a diagram showing an example of the photographed image of the alignment mark MA. Note that, Figure 13 the coordinate axes shown at the lower left of

[0184] In Figure 13 , VF1 represents the field of view of the 2D camera 50, and the center of the field of view VF1 in the coordinate system of the pedestal ST is set to (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). In addition, the number of pixels in the X direction of the field of view VF1 is set to n.

[0185] As Figure 13 shown, the alignment mark MA is extracted from the photographed image using a certain cross section (e.g., X = XL1, XL2, Y = YL1, YL2, etc.), and the center of the alignment mark MA, that is, the intersection point (Xc2, Yc2) of the cross shape, is calculated.

[0186] In Figure 13In the example shown, the alignment mark MA has a higher brightness compared to the surface of the sub-stage SST. In the cross-section extracted using Y = YL1, a portion where the brightness exceeds the threshold value th corresponding to the position of the alignment mark MA is detected. The average value of the pixel positions PxID of the portion where the brightness exceeds the threshold value th is obtained, and the average value of PxID is multiplied by a coefficient for converting the pixel position PxID into a distance. Thus, the X coordinate (X coordinate in the field-of-view coordinate system of the 2D camera 50) X(YL1) of the center of the alignment mark MA in the cross-section extracted using Y = YL1 is obtained.

[0187] As Figure 13 shown, the XY coordinates (XY coordinates in the field-of-view coordinate system of the 2D camera 50) of the center of the alignment mark MA are calculated using a plurality of cross-sections in the XY direction. Moreover, these average values are obtained as the XY coordinates (XY coordinates in the field-of-view coordinate system of the 2D camera 50) (Xc2, Yc2) of the center of the alignment mark MA.

[0188] The coordinates (Xc2, Yc2) of the center of the alignment mark MA are represented by the following equations. It should be noted that in the following equations, the number of cross-sections extracted in the X and Y directions are set to N and M, respectively.

[0189] Xc2 = {X(YL1) + X(YL2) + X(YL3) + … + X(YLN)} / N

[0190] Yc2 = {Y(XL1) + Y(XL2) + Y(XL3) + … + Y(XLM)} / M

[0191] It should be noted that in Figure 13 the example shown, preferably, the extracted cross-sections are extracted at a position about 20% from the end of the field of view VF.

[0192] Next, the position of the alignment mark MA in the coordinate system of the stage ST is obtained. The position of the center of the alignment mark MA in the coordinate system of the stage ST becomes (Xc2 + Xs2, Yc2 + Ys2).

[0193] Next, move the sub pedestal SST under the 3D shape measuring machine 52 and measure the alignment mark MA (step S102). In step S102, measure the shape of the alignment mark MA in the same manner as in step S100, and find the center of the alignment mark MA. It should be noted that in step S102, instead of the brightness and darkness of the alignment mark MA, the height difference in the Z direction in the 3D shape data is used to detect the alignment mark MA. When 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 set to (Xc3, Yc3) and the center of the visual field of the 3D shape measuring machine 52 in the coordinate system of the pedestal ST is set to (Xs3, Ys3), the position of the center of the alignment mark MA in the coordinate system of the pedestal ST becomes (Xc3 + Xs3, Yc3 + Ys3).

[0194] It should be noted that in the case of the 3D shape measuring machine 52 using methods such as focus change, instead of obtaining 3D shape data, a 2D image of the alignment mark MA can be obtained using the camera mounted on the 3D shape measuring machine 52, and alignment can be performed using this 2D image.

[0195] Next, find the positional relationship between the 2D camera 50 and the 3D shape measuring machine 52 (step S104).

[0196] As described above, the positions of the alignment mark MA obtained by the 2D camera 50 and the 3D shape measuring machine 52 are (Xc2 + Xs2, Yc2 + Ys2) and (Xc3 + Xs3, Yc3 + Ys3) respectively in the coordinate system of the pedestal ST.

[0197] Figure 14 and Figure 15 is a plan view for explaining the positional relationship between the 2D camera 50 and the 3D shape measuring machine 52. Figure 15 is Figure 14 an enlarged view of region XV of. In Figure 15 , the visual fields of the 2D camera 50 and the 3D shape measuring machine 52 are set to VF1 and VF2 respectively.

[0198] The position of the electrode pad P measured by the 2D camera 50 is set to (Xpn, Ypn) in the coordinate system of the pedestal ST. At this time, the position of the 3D shape measuring machine 52 observed from the 2D camera 50 is (Xc3 + Xs3 - Xc2 - Xs2, Yc3 + Ys3 - Yc2 - Ys2).

[0199] Therefore, regarding the position of the electrode pad P measured by the 2D camera 50, that is, (Xpn, Ypn) in the coordinate system of the pedestal ST, it is sufficient that the 3D shape measuring machine 52 measures it as (Xpn + Xc3 + Xs3 - Xc2 - Xs2, Ypn + Yc3 + Ys3 - Yc2 - Ys2) in the coordinate system of the pedestal ST.

[0200] Here, the transformation from the coordinate system of the 2D camera 50 to the coordinate system of the pedestal ST is as follows. The electrode pad P at the position (Xp2, Yp2) in the coordinate system of the 2D camera 50 becomes (Xpn, Ypn) = (Xs2 + Xp2, Ys2 + Yp2) in the coordinate system of the pedestal ST.

[0201] In the inspection apparatus 1A, it is considered that the positional relationship between the 2D camera 50 and the 3D shape measurement machine 52 changes due to the drift of the 2D camera 50 or the 3D shape measurement machine 52 caused by temperature changes. According to the present embodiment, by performing alignment between the 2D camera 50 and the 3D shape measurement machine 52, the accuracy of the inspection of the electrode pad P can be improved.

[0202] It should be noted that the cycle of implementation for each wafer W or each lot of the inspection object is not particularly limited regarding the alignment according to the present embodiment. The timing of implementation of the alignment can be determined, for example, by the degree of drift caused by the environment (temperature change).

[0203] In addition, in the present embodiment, the sub-pedestal SST formed with the alignment mark MA is connected to the pedestal ST, but the present disclosure is not limited thereto. For example, the above alignment mark MA can also be provided on the wafer W and applied to the alignment between the 2D camera 50 and the 3D shape measurement machine 52.

[0204] [Third Embodiment]

[0205] In the second embodiment, the alignment mark MA is provided to perform alignment between the 2D camera 50 and the 3D shape measurement machine 52. In contrast, in the third embodiment, alignment between the 2D camera 50 and the 3D shape measurement machine 52 is performed without using the alignment mark MA.

[0206] Figure 16 It is a diagram (during wafer-level inspection) showing the inspection apparatus according to the third embodiment of the present invention.

[0207] As Figure 16 shown, in the inspection apparatus 1B according to the present embodiment, the alignment camera 54 and the mirror pedestal MST formed with a mirror on the upper surface are both connected to the end of the pedestal ST.

[0208] In the present embodiment, the alignment camera 54 is used to detect the light beams output from the 2D camera 50 and the 3D shape measurement machine 52, thereby obtaining the positional relationship between the 2D camera 50 and the 3D shape measurement machine 52.

[0209] Figure 17 It is a flowchart showing the procedure of alignment between the 2D camera 50 and the 3D shape measurement machine 52.Figure 18 It is a block diagram showing an example of the 2D camera 50.

[0210] First, calibration of the 2D camera 50 is performed (step S200). In step S200, installation errors such as those of the light source 500 and the imaging element 512 (refer to Figure 18 ) caused by temperature changes in the inspection device 1B and its installation environment are measured and corrected.

[0211] In step S200, first, the mirror pedestal MST is moved under the 2D camera 50, and a light beam L1 is output from the light source 500 mounted on the 2D camera 50 toward the mirror pedestal MST. The light beam output from the light source 500 becomes parallel light under the action of the collimating lens 502, is reflected successively by the half mirror 504 and the mirror 506, and is converged by the condenser lens 508 to reach the mirror pedestal MST. The reflected light from the mirror pedestal MST passes through the condenser lens 508 and the mirror 506, passes through the half mirror 504, and is converged by the condenser lens 510 onto the imaging element 512. In this way, the light beam L1 reflected on the upper surface of the mirror pedestal MST is detected by the imaging element 512 of the 2D camera 50.

[0212] It should be noted that the optical system of the 2D camera 50 is not limited to the example of Figure 18 , and for example, the mirror 506 can be omitted.

[0213] In step S200, it is assumed that the light beam L1 is seen at the position (ΔX2d, ΔY2d) in the coordinate system of the 2D camera 50 (refer to Figure 19 ).

[0214] Next, the pedestal ST is moved so that the focus of the light beam L1 from the 2D camera 50 can be observed at the center of the field of view of the alignment camera 54, and the coordinates of the light beam L1 are detected (step S202). Here, it is assumed that the field of view size of the alignment camera 54 is sufficiently larger than the spot diameter of the light beam L1 mounted on the 2D camera 50 and sufficiently larger than the spot diameter of the measurement light of the 3D shape measuring machine 52.

[0215] In the coordinate system of the alignment camera 54, let the position of the light beam L1 be (ΔXp1, ΔYp1), and let the position of the pedestal ST at this time be (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 pedestal ST is represented by the following formula.

[0216] A = (Xs1 - ΔX2d - ΔXp1, Ys1 - ΔY2d - ΔYp1)

[0217] Next, move the pedestal ST so that the measurement light L2 (e.g., white light of a white light interference microscope, etc.) from the 3D shape measurement machine 52 can be observed at the center of the field of view of the alignment camera 54, and detect the coordinates of the measurement light L2 (step S204). In the coordinate system of the alignment camera 54, let the beam position of the 3D shape measurement machine 52 be (ΔXp2, ΔYp2), and set the position of the pedestal ST at this time as (Xs2, Ys2). At this time, the position B of the 3D shape measurement machine 52 in the coordinate system of the pedestal ST is represented by the following formula.

[0218] B = (Xs2 - ΔXp2, Ys2 - ΔYp2)

[0219] Next, obtain the positional relationship between the 2D camera 50 and the 3D shape measurement machine 52 (step S206). The position of the 3D shape measurement machine 52 relative to the 2D camera 50 is B - A.

[0220] Also in the inspection device 1B, the positional relationship between the 2D camera 50 and the 3D shape measurement machine 52 changes due to the offset of the 2D camera 50 or the 3D shape measurement machine 52 caused by temperature changes. According to the present embodiment, by performing alignment between the 2D camera 50 and the 3D shape measurement machine 52, the inspection accuracy of the electrode pad P can be improved.

[0221] It should be noted that, regarding the alignment according to the present embodiment, as in the second embodiment, the cycle of implementation for each wafer W or each lot, etc. of the inspection object is not particularly limited. The implementation timing of alignment can be determined, for example, by the degree of offset caused by the environment (temperature change).

[0222] It should be noted that when the center A of the field of view VF1 of the 2D camera 50 and the focal position of the light beam L1 are corrected, the correction using the mirror pedestal MST can be omitted (step S200).

[0223] In addition, when an external alignment light source is provided in the 3D shape measurement machine 52, alignment can be performed in the same manner as in the third embodiment by using the same light source.

[0224] [Fourth Embodiment]

[0225] In the present embodiment, as an example of the appearance inspection of the wafer, the detection of the stitch of the electrode pad P formed on the wafer W after wafer-level inspection is described, but the present disclosure is not limited thereto. For example, the present embodiment can also be applied to the measurement (detection) of any inspection object (e.g., scratches or foreign objects, etc.) on the wafer W.

[0226] Figure 20 and Figure 21This is a diagram showing the inspection apparatus according to the fourth embodiment of the present invention. Figure 21 It shows the state during the implementation of wafer-level inspection. Figure 20 It shows the state during the inspection (detection of traces) of the electrode pads P of the wafer W after wafer-level inspection.

[0227] During the implementation of wafer-level inspection, as Figure 21 shown, the test head 70 is mounted on the housing of the measurement unit 100 of the inspection apparatus 1C. Next, the probes 74 of the probe card 72 are brought into contact with the electrode pads P formed on the surface of the wafer W to be inspected to supply a test signal. Then, the tester measures the signal output by the semiconductor device (chip C) according to this test signal, and electrically inspects whether the semiconductor device operates normally. In wafer-level inspection, a part of the oxide film on the surface of the electrode pad P is scraped off by the probe 74, so that the probe 74 conducts with the electrode pad P.

[0228] When inspecting the electrode pads P of the wafer W, as Figure 20 shown, a three-dimensional shape measuring machine (hereinafter referred to as 3D shape measuring machine.) 52 is mounted on the measurement unit 100 of the inspection apparatus 1C.

[0229] In the inspection of the electrode pads P of the wafer W, first, an image of the chip C is captured using a 2D camera (for example, an imaging unit for aligning the wafer W), and electrode pad configuration information including information related to the configuration of the electrode pads P in the XY plane view is obtained.

[0230] Next, based on the above-mentioned electrode pad P configuration information, the inspection conditions for the inspection of the electrode pads P using the 3D shape measuring machine 52 are set. Specifically, for example, (A) the setting of the scanning speed in the height direction (Z direction), (B) the setting of the field of view size of the 3D shape measuring machine 52, or (C) the setting of the measurement order of the electrode pads P, etc. are performed.

[0231] Next, the inspection of the electrode pad P using the 3D shape measuring machine 52 is carried out according to the above inspection conditions. 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 measuring method in the 3D shape measuring machine 52 is not particularly limited. For example, the white light interference method, the SD-OCT method (Spectral Domain Optical Coherence Tomography), the FD-OCT method (Fourier Domain Optical Coherence Tomography), the laser confocal spot method, the triangulation method, the light sectioning method, the pattern projection method, the optical comb method (Optical Comb), and the focus variation method can be applied. In addition, as the 3D shape measuring machine 52 using the white light interference method, for example, the technologies described in Japanese Patent Laid-Open No. 2016-080564 or Japanese Patent Laid-Open No. 2016-161312 can be applied.

[0232] In the inspection of the electrode pad P, the 3D shape measuring machine 52 is used to measure its three-dimensional shape, and the characteristic quantity of the electrode pad P (for example, the maximum valley depth Sv of the stitch formed on 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. When the maximum valley depth Sv exceeds the threshold value, it is determined as abnormal (NG) because there is a high possibility that the base layer is exposed due to the stitch and the circuit is damaged.

[0233] According to the present embodiment, by appropriately setting the inspection conditions of the electrode pad P using the 3D shape measuring machine 52, the inspection of the stitch formed on the electrode pad P can be performed accurately and at high speed.

[0234] It should be noted that, in the present embodiment, the 2D camera 50 is used to obtain information related to the arrangement of the electrode pad P, but the present disclosure is not limited thereto. For example, the design information of the chip C can be used regarding the arrangement of the electrode pad P, and the acquisition process using the 2D camera 50 can be omitted. In addition, the image captured by the 2D camera 50 can be compared with the design information of the chip C, and when the difference between the two is equal to or greater than the threshold value, the information related to the arrangement of the electrode pad P can be obtained based on the image captured by the 2D camera 50.

[0235] (Structure of the inspection device)

[0236] As Figure 20 and Figure 21As shown, the inspection apparatus 1C according to the present embodiment includes a measurement unit 100 and a loading unit 200 that supplies and retrieves a wafer W to be inspected to and from the measurement unit 100. The measurement unit 100 and the loading unit 200 are separable. It should be noted that multiple measurement units 100 and loading units 200 can be provided, but for simplicity of explanation, only one of each is shown separately.

[0237] The loading unit 200 has a loading port for placing a wafer cassette and a transfer unit 202 that transfers the wafer W between each measurement unit 100 of the measurement unit 100 and the wafer cassette (see Figure 22 ).

[0238] When the wafer W is supplied from the loading unit 200 to each measurement unit 100, the wafer W is adsorbed and held by the holding surface of the pedestal ST of each measurement unit 100.

[0239] The pedestal moving mechanism 102 supports the lower surface of the pedestal ST (the surface opposite to the holding surface on which the wafer W is adsorbed and held). The pedestal moving mechanism 102 is configured to be movable in the XYZ directions and rotatable in the θ direction (the rotational direction about the Z direction). Thus, the wafer W adsorbed and held by the holding surface of the pedestal ST can move in the XYZ directions and rotate in the θ direction integrally with the pedestal ST by the pedestal moving mechanism 102.

[0240] As Figure 21 shown, at the time of wafer-level inspection, the test head 70 is mounted on the measurement unit 100 of the inspection apparatus 1C.

[0241] The probe card 72 is provided at a position opposed to the pedestal ST and is arranged substantially parallel to the holding surface of the pedestal ST. Regarding the probe card 72, a plurality of probes 74 are formed on the surface opposed to the pedestal ST. The probe card 72 is connected to the tester main body via the test head 70.

[0242] A plurality of chips C are formed on the wafer W, and each chip C includes one or more electrode pads P. By moving the pedestal ST in the XYZ directions or rotating it in the θ direction by the pedestal moving mechanism 102, alignment between the wafer W and the probe card 72 is performed so that each probe 74 touches the corresponding electrode pad P.

[0243] After alignment and contact between the probe 74 and the electrode pad P are performed by the inspection apparatus 1C, an electrical signal is sent from the tester main body to the chip C via the test head 70, the probe card 72, and the probe 74, and the electrical characteristics of the chip C on the wafer W are inspected (wafer-level inspection). The inspection result of the electrical characteristics is output in a form that can be confirmed by the operator through the input / output unit 12 (see Figure 22 ).

[0244] After the inspection of the electrical characteristics of the chip C on the wafer W is completed, the wafer W is transported and recovered from the inspection device 1C to the loading unit 200 by the transfer unit.

[0245] As Figure 20 shown, when inspecting the electrode pads P of the wafer W, the 3D shape measuring machine 52 is installed in the measuring unit 100 of the inspection device 1C. Then, the 3D shape measuring machine 52 sequentially detects the traces formed on the electrode pads P in the wafer-level inspection and determines the quality of the traces formed on the electrode pads P.

[0246] It should be noted that in the present embodiment, the 2D camera 50 and the 3D shape measuring machine 52 are separately installed, but it is not limited thereto. For example, it can also be configured to be able to switch between the 2D camera 50 and the 3D shape measuring machine 52 through a switching mechanism.

[0247] In addition, in the present embodiment, the test head 70 and the 3D shape measuring machine 52 can be attached to and detached from the measuring unit 100 of the inspection device 1C, but it is not limited thereto. For example, the wafer-level inspection and the inspection of the electrode pads P after the wafer-level inspection can also be performed by separate devices.

[0248] In addition, it is sufficient that the test head 70, the 2D camera 50, the 3D shape measuring machine 52, etc. can move relative to the pedestal ST, and it can also be configured to be able to move the test head 70, the 2D camera 50, the 3D shape measuring machine 52, etc. relative to the pedestal ST.

[0249] (Control System of the Inspection Device)

[0250] Figure 22 is a block diagram showing the control system of the inspection device according to the fourth embodiment of the present invention.

[0251] As Figure 22 shown, the inspection device 1C according to the present embodiment includes a control unit 10, an input / output unit 12, a transfer unit drive unit 14, a transfer arm drive unit 16, and a measurement control unit 18.

[0252] The control unit 10 includes a processor (e.g., CPU (Central Processing Unit), MPU (MicroProcessor Unit), etc.), a ROM (Read Only Memory), a RAM (Random Access Memory), and a memory device (e.g., HDD (Hard Disk Drive) or SSD (Solid State Drive), etc.). In the control unit 10, the functions of each part of the inspection device 1C are realized by the processor executing various programs stored in the memory device, such as control programs.

[0253] The input / output unit 12 includes a display unit (e.g., a liquid crystal display) for displaying a GUI (Graphical User Interface) for operating the inspection device 1C, and an operation unit (e.g., a touch panel, a keyboard, a pointing device, etc.) for accepting operation inputs from an operator, etc.

[0254] The transfer unit drive unit 14 includes a motor or the like for moving the transfer unit 202 in the XYZ directions and rotating it in the θ direction (around the Z direction) within the loading unit 200.

[0255] The transfer arm drive unit 16 includes a motor for extending and retracting the transfer arm 204 mounted on the transfer unit 202 in its longitudinal direction, and a control valve or the like for adsorbing the wafer W to the adsorption holes of the transfer arm 204. This control valve is connected to a vacuum component (pump) provided at the installation site of the inspection device 1C.

[0256] The control unit 10 controls the transfer unit 202 and the transfer arm 204 respectively using the transfer unit drive unit 14 and the transfer arm drive unit 16, takes out the wafer W from a plurality of wafer cassettes, or loads and unloads the wafer W with respect to a plurality of measurement units 100.

[0257] The alignment camera 54 is a device for detecting the front-end position of the probe 74, and is provided, for example, on the pedestal ST. The control unit 10 performs alignment between the probe 74 and the electrode pad P based on the detection result of the front-end position of the probe 74 and the detection result of the electrode pad P detected by the 2D camera 50.

[0258] The measurement control unit 18 performs drive control of the test head 70 for inspecting the wafer W provided in the measurement unit 100, shooting control of the 2D camera 50, measurement control of the 3D shape measuring machine 52, and shooting control of the alignment camera 54 in accordance with a control signal from the control unit 10. It should be noted that, for example, the technologies described in Japanese Unexamined Patent Application Publication No. 2019-102591 can be used as the test head 70 and the 2D camera 50.

[0259] (Setting of inspection conditions)

[0260] Next, the setting procedure of the inspection conditions will be described. Figure 23 is a plan view of the wafer W. As Figure 23 shown, a plurality of chips C are formed on the surface of the wafer W, and electrode pads P are formed on the plurality of chips C respectively.

[0261] Figure 24 is a plan view showing an enlarged view of the chip C ( Figure 23 region XXIV). Figure 24C1 is an example of a chip with a high density (number density) of electrode pads P per unit area. Figure 24 C2 is an example with a low density of electrode pads P per unit area.

[0262] In the case C1 where the density of the electrode pads P is high, a plurality (four in case C1) of electrode pads P can be included in the measurement field of view VF1 of the 3D shape measuring machine 52. In this case, by performing one scan in the Z direction by the 3D shape measuring machine 52, the measurement of the plurality of electrode pads P within the measurement field of view VF1 can be summarized and performed.

[0263] On the other hand, in the case C2 where the density of the electrode pads P is low, only one electrode pad P can be included in the measurement field of view VF1 of the 3D shape measuring machine 52. In this case, as shown by the reference numeral VF2, the measurement field of view is set narrow in accordance with the electrode pad P. By setting the measurement field of view narrow, the scanning speed of the 3D shape measuring machine 52 in the Z direction can be increased. Moreover, when the measurement field of view is narrow, the measurement range of the 3D shape is narrow and the amount of measurement data to be processed becomes small, so that the time required for analyzing the 3D shape can be shortened.

[0264] As described above, the larger the number of electrode pads P (the wider the measurement field of view) that can be included in the measurement field of view of the 3D shape measuring machine 52, the smaller the number of scans in the Z direction can be reduced. On the other hand, the narrower the measurement field of view of the 3D shape measuring machine 52, the shorter the time required for the scan in the Z direction and the analysis of the 3D shape can be.

[0265] Hereinafter, (A) the scanning speed in the Z direction and (B) the size of the measurement field of view (field range PA) in the inspection conditions will be specifically described.

[0266] When the 3D shape measuring machine 52 relatively scans the wafer W in the Z direction, imaging is performed based on a trigger signal output at every predetermined scale (interval). When the scanning speed of the 3D shape measuring machine 52 with respect to the wafer W is set to V C (nm / s) and the sampling interval of the 3D shape measuring machine 52 is set to D C (nm), the sampling frequency F S (Hz) of the 3D shape measuring machine 52 is expressed by the following formula.

[0267] F S =V C / D C (1)

[0268] The sampling frequency F S of the 3D shape measuring machine 52 becomes the number of observation images captured during one second when the 3D shape measuring machine 52 captures an observation image based on the trigger signal.

[0269] The maximum number of frames (captured images) that the 3D shape measurement machine 52 can capture in one second, i.e., the maximum frame rate F C The [fps] and the field of view range PA of the 3D shape measurement machine 52 generally have an approximately inverse proportional relationship as shown in the following formula.

[0270] F C ≈ A / PA (A: proportionality coefficient) (2)

[0271] At the sampling frequency F S greater than the maximum frame rate F C (F C < F S ), when shooting is instructed at a speed exceeding the maximum frame rate F C , the excess amount is ignored and so-called frame dropping occurs. When frame dropping occurs, it may lead to a decrease in measurement accuracy. Therefore, it is necessary to set the maximum frame rate F C to be greater than or equal to the sampling frequency F S (F C ≥ F S ). In practice, considering the influence of vibration, etc., the sampling frequency F S is set to F S = α × F C (0 < α < 1).

[0272] When substituting F S = α × F C into formula (1) and formula (2), the following formula (3) can be obtained.

[0273] V C ≈ D C × α × A / PA (3)

[0274] As shown in formula (3), the narrower the field of view range PA, the faster the scanning speed V in the Z direction can be C . For example, let the sampling interval D C = 20nm, α = 0.1, A = 8 × 10 9 , and the scanning range in the Z direction = 40μm. An example of the measurement time in this case is shown in Figure 25 .

[0275] As Figure 25 shown, when the number of pixels in the measurement field of view is 4 million pixels, the measurement time is about 19 seconds. In contrast, when it is 1 million pixels, the measurement time is about 7.5 - 9.5 seconds.

[0276] In the case (Example C1) where the measurement field of view includes 4 electrode pads P, when the measurement field of view is set to 4 million pixels, the measurement time for each electrode pad becomes 19÷4 = 4.75 seconds per pad. In contrast, when the measurement field of view is set to 1 million pixels (when the number of pixels allocated to each electrode pad is made approximately the same), the measurement time for each electrode pad becomes 7.5 to 9.5 seconds per pad. That is, in the case where the measurement field of view includes 4 electrode pads P, it is advantageous to set the measurement field of view to 4 million pixels.

[0277] On the other hand, in the case (Example C2) where the measurement field of view includes only 1 electrode pad P, when the measurement field of view is set to 4 million pixels, the measurement time for each electrode pad becomes 19 seconds per pad. In contrast, when the measurement field of view is set to 1 million pixels, the measurement time for each electrode pad becomes 7.5 to 9.5 seconds per pad. That is, in the case where the measurement field of view includes only 1 electrode pad P, it is advantageous to set the measurement field of view to 1 million pixels.

[0278] As described above, by appropriately selecting the size of the measurement field of view according to the configuration and density of the electrode pads P to be measured, the inspection of the electrode pads P can be speeded up.

[0279] Next, the functions of setting the inspection conditions (A) and (B) will be described with reference to Figure 26 and Figure 27 The functions shown in are implemented by the processor of the control unit 10 obtaining the necessary data such as the electrode pad configuration information D10 and executing software for realizing the following functions. That is, the control unit 10 is an example of a calculation unit. Figure 26 and Figure 27 The functions shown in are implemented by the processor of the control unit 10 obtaining the necessary data such as the electrode pad configuration information D10 and executing software for realizing the following functions. That is, the control unit 10 is an example of a calculation unit.

[0280] Figure 26 is a block diagram showing the function of setting the scanning speed in the Z direction between the 3D shape measuring machine 52 and the wafer W. Figure 26 An example of setting the optimal scanning speed (measurement time) in the Z direction according to the size of the measurement field of view in the case of measuring a plurality of electrode pads P is shown.

[0281] The field of view size temporary selection unit 300 temporarily selects the field of view size of the measurement field of view. This temporary selection can also be performed by receiving an operation input from the operator via the operation unit of the input / output unit 12, and can also be automatically selected, for example, according to the type of the wafer W (lot) to be inspected.

[0282] The Z-scan cost calculation unit 302 obtains electrode pad configuration information D10 including information related to the configuration of the electrode pads P from the image of the wafer W captured by the 2D camera 50. In addition, the Z-scan cost calculation unit 302 obtains the result temporarily selected by the field-of-view size temporary selection unit 300. Further, the Z-scan cost calculation unit 302 calculates the measurement cost required for the Z-direction scan (i.e., the Z-direction scan speed or the measurement time including the time required for the scan) based on the electrode pad configuration information D10 and the result of the temporary selection of the field-of-view size.

[0283] As described above, by setting the measurement field of view narrow, the scan speed of the 3D shape measurement machine 52 along the Z direction can be increased. Further, when the measurement field of view is narrow, the measurement range of the 3D shape is narrow, and the amount of measurement data to be processed becomes small, so the time required for analyzing the 3D shape can be shortened.

[0284] The Z-scan cost calculation unit 302 calculates the Z-direction scan speed or the measurement time including the time required for the scan based on an index related to the Z-direction scan speed and an index related to the size of the measurement field of view. Here, the index related to the Z-direction scan speed is, for example, the rotation speed of the motor for relatively moving the 3D shape measurement machine 52 and the wafer W in the Z direction, the current supplied to the motor, or the pulse interval of the motor (in the case of PWM (Pulse Width Modulation) control). Specifically, the narrower the measurement field of view of the 3D shape measurement machine 52, the larger the calculated value of the scan speed by the Z-scan cost calculation unit 302. In addition, the narrower the measurement field of view of the 3D shape measurement machine 52, or the larger the number of electrode pads that can be included in the measurement field of view, the smaller the calculated value of the measurement time by the Z-scan cost calculation unit 302.

[0285] The Z-scan cost display unit 304 outputs the calculation result calculated by the Z-scan cost calculation unit 302 to the display unit of the input / output unit 12. Thereby, the operator can confirm the Z-direction scan speed or the measurement time corresponding to the field-of-view size of the temporarily selected measurement field of view. Further, by receiving an operation input from the operator via the input / output unit 12, the temporary selection of the field-of-view size of the measurement field of view can be changed, and the Z-direction scan speed or the measurement time can be recalculated. That is, the operator can select (formally select) the Z-direction scan speed or the measurement time in a trial-and-error manner while referring to the recalculated result.

[0286] The field-of-view size formal selection unit 306 selects (formally selects) the Z-direction scan speed or the measurement time by receiving an operation input from the operator via the input / output unit 12.

[0287] Note that in this embodiment, it is assumed that the operator makes an official selection via the input / output unit 12, but the present disclosure is not limited thereto. For example, for all patterns of the electrode pad configuration information and the size of the measurement field of view (e.g., the patterns registered in the inspection device 1C), the control unit 10 may calculate them and automatically select the size of the measurement field of view with the shortest measurement time as the calculation result. Additionally, the control unit 10 may calculate based on the electrode pad configuration information for each pattern of the size of the measurement field of view in sequence and automatically select the size of the measurement field of view at the time point when the measurement time (measurement cost) becomes below the reference value. That is, the control unit 10 may also automatically select the size of the measurement field of view whose measurement cost meets a specified reference (e.g., the shortest measurement time or the measurement time becomes below the reference value among the results calculated for all patterns).

[0288] Figure 27 It is a block diagram showing the function of setting the size of the measurement field of view of the 3D shape measuring machine 52.

[0289] As Figure 27 shown, a variety of field of view size setting information D20 is pre-stored in the memory 310 of the control unit 10. The field of view size setting information D20 may be pre-registered in the memory 310 by the probe, the manufacturer of the inspection device 1C, the operator, or the manager of the operator, etc.

[0290] The measurement time calculation unit 312 obtains electrode pad configuration information D10 including information related to the configuration of the electrode pads P from the image of the wafer W captured by the 2D camera 50. In addition, the measurement time calculation unit 312 reads the field of view size setting information D20 from the memory 310. The measurement time calculation unit 312 calculates the measurement time for each field of view size setting information D20 based on the electrode pad configuration information D10. The measurement time calculation unit 312 calculates the measurement time based on the index related to the scanning speed in the Z direction and the index related to the size of the measurement field of view. Specifically, the narrower the measurement field of view of the 3D shape measuring machine 52, the greater the calculated value of the scanning speed by the measurement time calculation unit 312. Additionally, the narrower the measurement field of view of the 3D shape measuring machine 52, or the more the number of electrode pads that can be included in the measurement field of view, the smaller the calculated value of the measurement time by the measurement time calculation unit 312.

[0291] The measurement time display unit 314 outputs the calculation result calculated by the measurement time calculation unit 312 to the display unit of the input / output unit 12. Thereby, the operator can confirm the measurement time for each field of view size setting information D20.

[0292] As described above, the larger the number of electrode pads P that can be included in the measurement field of view of the 3D shape measurement machine 52 (the wider the measurement field of view), the smaller the number of scans in the Z direction can be reduced, and the shorter the measurement time can be. In addition, when the measurement field of view is narrow, the measurement range of the 3D shape is narrow, and the amount of measurement data to be processed becomes small, so the time required for analyzing the 3D shape can be shortened.

[0293] The field of view size selection unit 316 selects the field of view size of the measurement field of view by receiving an operation input from the operator via the input / output unit 12.

[0294] Next, the determination algorithm for the measurement order of the (C) electrode pad P in the inspection conditions will be described. Figure 28 It is a diagram for explaining the measurement order of the electrode pad P.

[0295] In Figure 28 In the example shown, the inspection of the electrode pads P is sequentially performed from the upper side (+Y) of the chip C and from the left side to the right side (+X side). The control unit 10 adjusts the relative positions of the 3D shape measurement machine 52 and the wafer W so that the four electrode pads P at the upper left end are within the measurement field of view VF(1) at the first inspection position. At the second inspection position, the control unit 10 moves the 3D shape measurement machine 52 relative to the wafer W to the right side (+X side) so that the inspected electrode pads P are not included in the measurement field of view VF(2). Here, the control unit 10 is an example of the measurement field of view moving unit.

[0296] Repeatedly scanning to the +X side, when the inspection of the electrode pads P at the end on the +X side is completed (at the fifth position), at the sixth inspection position, the 3D shape measurement machine 52 returns to the left side (-X side) relative to the wafer W and moves to the lower side (-Y side) so that the inspected electrode pads P are not included in the measurement field of view VF(6). By sequentially repeating the above steps, the inspection of all the electrode pads P of the chip C is performed.

[0297] In this case, when the number of measurement parts in one chip is set to n(p) and the time required for measuring one measurement part is set to t1(p), the time T1(p) required for measuring one chip is expressed by the following formula. Here, p is the number of pixels of the measurement field of view VF(1), VF(2),....

[0298] T1(p) = n(p) × t1(p)

[0299] It should be noted that in Figure 26In the example shown, the 3D shape measuring machine 52 returns to the -X side after reaching the end on the +X side, but the present disclosure is not limited to this. For example, the 3D shape measuring machine 52 may perform inspection in a zigzag manner while moving to the -X side after reaching the end on the +X side. Additionally, for example, inspection may be performed in a spiral manner such as reaching the end on the +X side, reaching the end on the -Y side, reaching the end on the -X side, and reaching the end on the +Y side of the uninspected area.

[0300] (Inspection of the electrode pad P using the 3D shape measuring machine 52)

[0301] After setting the above inspection conditions, the control unit 10 calculates a feature amount related to the stitch M based on the measurement data of the surface area of the electrode pad P that has been extracted, and determines the quality of the electrode pad P. In the present embodiment, the maximum valley depth Sv defined by JIS B 0681-2:2018 or ISO 25178-2:2012 is used as the feature amount.

[0302] Figure 29 is a diagram for explaining the feature amount (maximum valley depth Sv) of the stitch M formed on the electrode pad P. In Figure 29 , the three-dimensional shape (concavity and convexity) of the surface of the electrode pad P is represented by a curve along the X direction.

[0303] The maximum valley depth Sv is the absolute value of the minimum value of the height with respect to the mean plane Pm in which the height (Z coordinate) becomes the average value (arithmetic mean) on the surface of the electrode pad P. It should be noted that in Figure 29 , Sp is the maximum peak height, and it is the maximum value with respect to the mean plane Pm. Additionally, Sz is the maximum height representing the distance from the highest point to the lowest point on the surface of the electrode pad P, and Sz = Sp + Sv.

[0304] The control unit 10 determines 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, when the maximum valley depth Sv is equal to or greater than the design value of the thickness of the electrode pad P, or 90% or more of the design value, the electrode pad P is determined to be NG.

[0305] Note that the determination is not limited to the above examples. For example, the threshold related to the maximum valley depth Sv of the determination can also be changed based on the thickness of the electrode pad P, the ratio of the area of the stitch M to the electrode pad P, the position, or the strength (brittleness) of the material of the electrode pad P. For example, it is considered that the thicker the electrode pad P, the less likely the base layer is to be exposed. Therefore, the threshold related to the maximum valley depth Sv can also be set to a value closer to the design value of the thickness of the electrode pad P. In addition, it is considered that the lower the strength (the more brittle) the material of the electrode pad P, the higher the possibility of cracking or the like of the electrode pad P. Therefore, the threshold related to the maximum valley depth Sv can also be set to a smaller value relative to the design value of the thickness of the electrode pad P.

[0306] In addition, it is considered that when the ratio of the area of the stitch M to the electrode pad P is equal to or greater than the reference value, when the portion of the electrode pad P other than the stitch M is equal to or less than the reference value, when the distance between the end of the electrode pad P and the stitch M is equal to or less than the reference value, etc., the possibility of cracking or the like of the electrode pad P is high. Therefore, it can also be determined as NG. In this case, the reference values can also be adjusted according to the strength of the material of the electrode pad P. For example, the lower the strength (the more brittle) the electrode pad P, the stricter the reference for determining NG.

[0307] According to the present embodiment, by appropriately setting the inspection conditions inspected by the 3D shape measuring machine 52, the inspection of the electrode pad P can be accurately and quickly performed.

[0308] Note that in the present embodiment, the inspection object is the stitch M formed on the electrode pad P. However, as described above, the present disclosure is not limited thereto. For example, the present embodiment can also be applied to an appearance inspection for detecting inspection objects such as scratches or foreign matters on the wafer W.

[0309] For example, when the inspection object is a scratch on the wafer W, the wafer W can also be determined to be abnormal when at least one characteristic quantity among the size of the scratch (for example, the maximum size or the minimum size), the depth of the scratch (for example, the maximum valley depth Sv or the maximum height Sz), the area of the scratch (for example, the ratio of the area occupied by the scratch per unit area of the wafer W), the configuration of the scratch (for example, the number per unit area, etc.) exceeds the reference value. In addition, instead of or in addition to the above characteristic quantities, the wafer W can also be determined to be abnormal when the distance between the scratch and the device is equal to or less than the reference value.

[0310] Alternatively, when the object to be inspected is a foreign object, for example, when at least one characteristic quantity among the size of the foreign object (e.g., the maximum size or the minimum size) and the arrangement of the foreign objects (e.g., the number per unit area, etc.) exceeds a reference value, the wafer W can be determined to be abnormal. Alternatively, instead of or in addition to the above characteristic quantities, the quality of the wafer W can be determined based on the type of the foreign object. For example, when it is presumed based on the three-dimensional shape of the foreign object that the foreign object is a foreign object that can be easily removed by air or the like, the wafer W can be determined to be normal regardless of the above characteristic quantities.

[0311] Alternatively, when the object to be inspected is a scratch or a foreign object, for example, the position of the scratch or the foreign object is detected based on the image of the wafer W captured by the 2D camera 50, and the inspection object arrangement information related to the arrangement of the inspection object is obtained. Then, the inspection cost can be calculated based on the inspection object arrangement information and the size of the measurement field of view of the 3D shape measuring machine 52.

[0312] [Fifth Embodiment]

[0313] In the present embodiment, as an example of the appearance inspection of the wafer, the case of detecting the stitch of the electrode pad P formed on the wafer W after the wafer-level inspection is described, but the present disclosure is not limited thereto. For example, the present embodiment can also be applied to the measurement (detection) of any inspection object (e.g., a scratch or a foreign object, etc.) on the wafer W.

[0314] Figure 30 and Figure 31 is a diagram showing an inspection apparatus according to the fifth embodiment of the present invention. Figure 31 shows the state during the implementation of the wafer-level inspection, Figure 30 shows the state during the inspection (detection of the stitch) of the electrode pad P of the wafer W after the wafer-level inspection.

[0315] When implementing the wafer-level inspection, as Figure 31 shown, the test head 70 is mounted on the housing of the measurement unit 100 of the inspection apparatus 1D. Next, the probe 74 of the probe card 72 is brought into contact with the electrode pad P formed on the surface of the inspection object wafer W to supply a test signal. Then, the signal output by the semiconductor device (chip C) according to the test signal is measured by the tester, and it is electrically inspected whether the semiconductor device operates normally. In the wafer-level inspection, a part of the oxide film on the surface of the electrode pad P is scraped off by the probe 74, so that the probe 74 is electrically connected to the electrode pad P.

[0316] When inspecting the electrode pad P of the wafer W, as Figure 30As shown, a three-dimensional shape measuring machine (hereinafter referred to as 3D shape measuring machine) 52 is installed in the measuring unit 100 of the inspection device 1D. The 3D shape measuring machine 52 is a device that measures the three-dimensional shape of an inspection object in a non-contact manner and is detachably installed in the first opening formed in the partition wall 110 of the measuring unit 100.

[0317] In the inspection of the electrode pad P of the wafer W, first, a 2D camera (for example, an imaging unit for aligning the wafer W) 50 is used to capture an image of the chip C, and electrode pad configuration information including information related to the configuration of the electrode pad P in the XY plane view is obtained.

[0318] Next, based on the above-mentioned electrode pad P configuration information, the electrode pad P to be inspected is aligned with the 3D shape measuring machine 52, and the electrode pad P is inspected by the 3D shape measuring machine 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 measuring method in the 3D shape measuring machine 52 is not particularly limited, and for example, white light interference method, SD-OCT method (Spectral Domain Optical Coherence Tomography), FD-OCT method (Fourier Domain Optical Coherence Tomography), laser confocal spot method, triangulation method, light section method, pattern projection method, optical comb method (Optical Comb), and focus variation method can be applied. In addition, as the 3D shape measuring machine 52 using the white light interference method, for example, the technologies described in Japanese Patent Laid-Open No. 2016-080564 or Japanese Patent Laid-Open No. 2016-161312 can be applied.

[0319] In the inspection of the electrode pad P, a 3D shape measuring machine 52 is used to measure its three-dimensional shape, and the characteristic quantity of the electrode pad P (for example, the maximum valley depth Sv of the stitch formed on 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. The maximum valley depth Sv is the absolute value of the minimum value of the height with respect to the average plane Pm in which the height (Z coordinate) in the surface of the electrode pad P becomes the average value (arithmetic mean). When the maximum valley depth Sv exceeds the threshold value, it is considered that the base layer is exposed due to the stitch and the possibility of damage to the circuit is high, and it is determined as abnormal (NG). Specifically, based on the relationship between the maximum valley depth Sv and the design value of the thickness of the electrode pad P, when the maximum valley depth Sv is equal to or greater than the design value of the thickness of the electrode pad P, or 90% or more of the design value, the electrode pad P is determined as NG.

[0320] It should be noted that the determination is not limited to the above examples. For example, the threshold value related to the determination of the maximum valley depth Sv can also be changed based on the thickness of the electrode pad P, the proportion of the area of the stitch M with respect to the electrode pad P, the position, or the strength (brittleness) of the material of the electrode pad P. For example, it is considered that the thicker the electrode pad P, the less likely the base layer is to be exposed, so the threshold value related to the maximum valley depth Sv can also be set to a value closer to the design value of the thickness of the electrode pad P. In addition, it is considered that the lower the strength (brittleness) of the material of the electrode pad P, the higher the possibility of cracking or the like in the electrode pad P, so the threshold value related to the maximum valley depth Sv can also be set to a value smaller than the design value of the thickness of the electrode pad P.

[0321] In addition, it is considered that when the proportion of the area of the stitch M with respect to the electrode pad P is above the reference value, when the portion other than the stitch M in the electrode pad P is below the reference value, when the distance between the end of the electrode pad P and the stitch M is below the reference value, etc., the possibility of cracking or the like in the electrode pad P is high, so it can also be determined as NG. In this case, the reference values can also be adjusted according to the strength of the material of the electrode pad P. For example, the lower the strength (brittleness) of the electrode pad P, the stricter the reference for determining NG.

[0322] Note that in the present embodiment, information related to the configuration of the electrode pads P is obtained using the 2D camera 50, but the present disclosure is not limited thereto. For example, design information of the chip C may be used regarding the configuration of the electrode pads P, and the acquisition process using the 2D camera 50 may be omitted. Additionally, the image captured by the 2D camera 50 may be compared with the design information of the chip C, and when the difference between the two is equal to or greater than a threshold value, information related to the configuration of the electrode pads P may be obtained based on the image captured by the 2D camera 50.

[0323] As Figure 30 and Figure 31 shown, the measurement unit 100 according to the present embodiment has a measurement chamber 112 surrounded by a partition (separator) 110, and wafer-level inspection and inspection of the electrode pads P are performed in the measurement chamber 112.

[0324] The partition 110 of the measurement chamber 112 is formed of a material with high light-shielding properties. The light-shielding rate of the partition 110 (for example, the light-shielding rate based on JIS L1055:2009) is preferably 90% or more as an example. Note that the partition 110 may also contain a material with high heat insulation properties (low thermal conductivity).

[0325] The measurement chamber 112 is separated from the outside of the measurement chamber 112 by the partition 110. The partition 110 has a function of separating the air environments inside and outside the measurement chamber 112. That is, by providing the partition 110, the influence of external disturbances (such as noise, temperature, and vibration, etc.) occurring outside the measurement chamber 112 on the inside of the measurement chamber 112 is suppressed.

[0326] The partition 110 has sound insulation performance (vibration-proof performance). As a structure for realizing the sound insulation performance of the partition 110, for example, a structure in which a sound-absorbing material is placed in the internal structure of the partition 110, or a structure made such that the resonance frequency of the partition 110 itself is higher than the frequency at which vibration is caused by noise can be cited. This frequency also depends on the surrounding environment and is preferably 100 to 200 Hz or more in one example.

[0327] Generally, in a semiconductor manufacturing factory, noise sometimes occurs from air conditioners and other production equipment, and the level of this noise exceeds 70 dB. When this noise is transmitted to the pedestal ST, it becomes vibration. When the pedestal ST vibrates during measurement, the relative distance between the 3D shape measuring machine 52 and the wafer W changes, and sometimes a measurement error occurs in the height direction (Z direction) of the inspection object on the wafer W. Thus, vibration generated from air conditioners and other production equipment may also be a cause of measurement error.

[0328] In the present embodiment, the reduction in measurement accuracy caused by vibration can be prevented by the partition 110 having sound insulation performance.

[0329] Furthermore, in the present embodiment, the partition wall 110 can suppress the influence of radiant heat from the outside of the measurement chamber 112 on the pedestal ST and the wafer W, and can suppress the reduction of the measurement accuracy due to the deformation (thermal shift) of the wafer W caused by temperature changes. In addition, even if a temperature non-uniformity occurs inside the measurement chamber 112 due to the temperature rise of the pedestal ST or the like, since the disturbance of the air caused by the temperature non-uniformity is limited within the measurement chamber 112, the air inside the measurement chamber 112 is stabilized early.

[0330] In addition, measurement optical systems such as the 2D camera 50 and the 3D shape measurement machine 52 are sometimes affected by external interference light from the outside of the measurement chamber 112. Especially when the 3D shape measurement machine 52 is of the confocal point type, it is easily affected by such external interference light. As described above, the partition wall 110 according to the present embodiment has high light-shielding properties, so that it is possible to prevent the reduction of the measurement accuracy caused by external interference light.

[0331] Furthermore, as Figure 30 and Figure 31 shown, the loading unit 200 according to the present embodiment has a preparation chamber 212 surrounded by a partition wall (separator) 210, and the wafers W before and after inspection are stored in the preparation chamber 212. The partition wall 210, like the partition wall 110, has a function of separating the air environments inside and outside the preparation chamber 212.

[0332] The temperature of the preparation chamber 212 of the loading unit 200 is shielded from light and isolated from the outside air in the same manner as the measurement chamber 112 of the measurement unit 100, reproducing the same environment as the measurement chamber 112. Compared with the case where the wafer W is directly set (loaded) from the outside to the pedestal ST in the measurement chamber 112, when the wafer W is temporarily standby in the preparation chamber 212 that reproduces the same environment as the measurement chamber 112, at the time point when the wafer W is loaded onto the pedestal ST in the measurement chamber 112, the temperature difference between the wafer W and the pedestal ST or the air in the measurement chamber 112 becomes smaller (preferably zero). Therefore, it is possible to reduce the measurement error caused by temperature non-uniformity.

[0333] Here, when explaining the measurement error, for example, when there is a temperature difference between the pedestal ST and the wafer W, deformation may occur in the wafer W and the measurement accuracy may be reduced. In addition, when there is a temperature difference between the wafer W and the air in the measurement chamber 112, a temperature distribution may occur in the air above the wafer W, causing air disturbance (for example, air refractive index distribution). When the air refractive index distribution occurs, fluctuations in the optical path length may occur in the XY plane during measurement by the 3D shape measurement machine 52. As a result, the flatness deteriorates in the measurement result measured by the 3D shape measurement machine 52, and deterioration of the measurement accuracy may occur.

[0334] In this embodiment, by providing the loading unit 200 and the preparation chamber 212, the measurement error caused by temperature unevenness can be reduced, and the measurement accuracy can be improved. In addition, during the standby period when the wafer W is temporarily on standby in the preparation chamber 212, the measurement of another wafer W can be performed in the measurement chamber 112, so that the total time required for measurement can be shortened.

[0335] Furthermore, in this embodiment, by providing a temperature adjustment unit 232 and a temperature detection unit 234 in the preparation chamber 212 of the loading unit 200, the standby time in the preparation chamber 212 can be shortened. That is, the temperature of the preparation chamber 212 of the loading unit 200 is maintained at a prescribed inspection temperature by the temperature adjustment unit 232 (such as a heater or a chiller, etc.) during the inspection of the wafer W. The temperature detection unit 234 includes a temperature sensor that measures the temperature inside the preparation chamber 212 and the temperature of the wafer W, and controls the output of the temperature adjustment unit 232 based on the measurement results obtained by the temperature detection unit 234. Thereby, the temperature of the wafer W can be adjusted to the temperature during inspection in the measurement chamber 112.

[0336] It should be noted that a humidifier and a humidity sensor for adjusting the humidity inside the preparation chamber 212 may also be provided inside the preparation chamber 212. In addition, the temperature adjustment unit 232, the temperature detection unit 234, the humidifier, and the humidity sensor can also be omitted.

[0337] When the temperature adjustment unit 232 and the temperature detection unit 234 are provided inside the preparation chamber 212 as in this embodiment, a temperature detection unit (temperature sensor) may also be provided inside the measurement chamber 112.

[0338] The pedestal ST inside the measurement chamber 112 includes a motor, and heat is generated during the operation of the motor. Even if the joint portion between the preparation chamber 212 and the measurement chamber 112 is reduced, when the baffles 120 and 220 are opened, air mixing or heat exchange will occur between the preparation chamber 212 and the measurement chamber 112. Therefore, it is difficult to make the heat exchange between the preparation chamber 212 and the measurement chamber 112 zero.

[0339] The temperature adjustment unit 232 makes the temperature inside the preparation chamber 212 approach the temperature inside the measurement chamber 112 based on the difference in the detected temperature values detected by the temperature detection units provided in the preparation chamber 212 and the measurement chamber 112.

[0340] It should be noted that a temperature adjustment unit (such as a heater or a chiller, etc.) may be provided in the measurement chamber 112 instead of the temperature adjustment unit 232 inside the preparation chamber 212. That is, based on the difference in the detected temperature values detected by the temperature detection units provided in the preparation chamber 212 and the measurement chamber 112, the temperature inside the measurement chamber 112 can be made to approach the temperature inside the preparation chamber 212. In addition, temperature adjustment units can also be provided in both the measurement chamber 112 and the preparation chamber 212.

[0341] The partition wall 210 adjacent to the preparation chamber 212 is also formed of a material with high light-shielding property, similar to the partition wall 110 of the measurement chamber 112. In addition, similar to the partition wall 110, the partition wall 210 may also contain a material with high heat insulation (low thermal conductivity). Thereby, the temperature of the wafer W in the preparation chamber 212 is not easily transmitted to the measurement chamber 112, suppressing the influence on the measurement chamber 112.

[0342] The partition wall 210 also has sound insulation performance (vibration-proof performance) similar to the partition wall 110. As a structure for realizing the sound insulation performance of the partition wall 210, for example, a structure in which a sound-absorbing material is placed in the internal structure of the partition wall 210, or a structure made such that the resonance frequency of the partition wall 210 itself is higher than the frequency of vibration caused by noise can be cited. This frequency also depends on the surrounding environment, but is preferably 100 to 200 Hz or more as an example.

[0343] In the present embodiment, the vibration caused by the sound picked up by the loading unit 200 can be prevented from being transmitted to the measurement chamber 112 (stage ST) and the 3D shape measuring machine 52 through the partition wall 210 having sound insulation performance. Thereby, a decrease in measurement accuracy due to vibration can be prevented.

[0344] A second opening for loading and unloading the wafer W is provided in the partition wall 110 of the measurement unit 100. A baffle 120 (an example of a first baffle) is provided at the second opening, and the second opening can be opened and closed. On the other hand, an opening for loading and unloading the wafer W is also provided in the partition wall of the loading unit 200, a baffle 220 (an example of a second baffle) is provided at the opening, and the opening can be opened and closed.

[0345] As described above, the transfer path of the wafer W between the measurement unit 100 and the loading unit 200 is separated by the baffles 120 and 220. The baffles 120 and 220 are also formed of a material with high light-shielding property, similar to the partition walls 110 and 210. In addition, similar to the partition walls 110 and 210, the baffles 120 and 220 may also contain a material with high heat insulation (low thermal conductivity). In addition, the baffles 120 and 220 can maintain the airtightness inside the measurement chamber 112 and the preparation chamber 212 when closed. Thereby, the temperature of the wafer W in the preparation chamber 212 is not easily conducted to the measurement chamber 112.

[0346] It should be noted that in Figure 30 and Figure 31 , an example of an up-and-down opening / closing and winding type is shown for the baffles 120 and 220, but the types of the baffles are not limited to this. The types of the baffles can be, for example, a folding type, a swing-up type, or a sliding type, etc. In addition, a movable partition or the like instead of the baffles 120 and 220 can also be used, and the partition can be constituted by a hollow member.

[0347] Here, the measurement unit 100 and the loading unit 200 can also reduce their physical contact with each other, or be separated from each other in advance. Thereby, heat conduction from the loading unit 200 to the measurement unit 100 can be suppressed, and the thermal resistance can be increased.

[0348] In addition, the mass of the preparation chamber 212 can also be smaller than the mass of the measurement chamber 112. In addition, the joint portion between the measurement unit 100 and the loading unit 200 can also be reduced. Thereby, the vibration generated in the preparation chamber 212 can be suppressed from being transmitted to the 3D shape measuring machine 52 and the measurement chamber 112 of the measurement unit 100.

[0349] An opening (an example of the third opening) for setting the fan 130 is provided in the partition wall 110 of the measurement chamber 112. The fan 130 circulates air in the measurement chamber 112 to make the air environment in the measurement chamber 112 uniform. Thereby, the temperature unevenness in the measurement chamber 112 can be eliminated.

[0350] The fan baffle 132 is a baffle for opening and closing the opening where the fan 130 is provided. The type of control of the fan baffle 132 is not particularly limited, and it can be an electric type or a manual type that is opened and closed electrically or manually, or a wind pressure type that is opened and closed by wind pressure. It should be noted that in Figure 30 and Figure 31 as an example of the fan baffle 132, an example including a movable louver is shown, but the type of the fan baffle 132 is not limited thereto, and it can also be a winding type, a folding type, an upward turning type, a sliding type, etc.

[0351] It should be noted that when the air in the measurement chamber 112 can be easily circulated, or when the volume of the measurement chamber 112 is small, etc., the fan 130 and the fan baffle 132 can be omitted.

[0352] According to the present embodiment, by providing the partition wall 110 surrounding the measurement chamber 112, the air inside the measurement chamber 112 can be stabilized early, and a decrease in the inspection accuracy of the three-dimensional shape due to air disturbance can be suppressed.

[0353] It should be noted that in the present embodiment, the loading unit 200 and the preparation chamber 212 can also be omitted. In this case, after the wafer W is set on the pedestal ST, it is only necessary to standby for a certain period of time until the temperature unevenness is eliminated. In this way, when the loading unit 200 and the preparation chamber 212 are omitted, by setting the standby time, deterioration of the measurement accuracy can be prevented.

[0354] (Structure of the inspection device)

[0355] As Figure 30 and Figure 31As shown, the inspection apparatus 1D according to the present embodiment includes a measurement unit 100 and a loading unit 200 that supplies and retrieves a wafer W to be inspected to and from the measurement unit 100. The measurement unit 100 and the loading unit 200 are separable. It should be noted that a plurality of measurement units 100 and loading units 200 may be provided, but for simplicity of explanation, only one of each is shown.

[0356] The loading unit 200 has a loading port for placing a wafer cassette 230 and a transfer unit 202 that transfers the wafer W between each measurement unit 100 and the wafer cassette 230 (see Figure 32 ).

[0357] When the wafer W is supplied from the loading unit 200 to each measurement unit 100, the wafer W is adsorbed and held by the holding surface of the pedestal ST of each measurement unit 100.

[0358] A pedestal moving mechanism 102 supports the lower surface of the pedestal ST (the surface opposite to the holding surface on which the wafer W is adsorbed and held). The pedestal moving mechanism 102 is configured to be movable in the XYZ directions and rotatable in the θ direction (the rotational direction about the Z direction). Thus, the wafer W adsorbed and held by the holding surface of the pedestal ST can move in the XYZ directions and rotate in the θ direction integrally with the pedestal ST by the pedestal moving mechanism 102.

[0359] It should be noted that in the present embodiment, it may be adjusted so that the heat capacity of the pedestal ST becomes larger. For example, the heat capacity of the pedestal ST can be increased by making the thickness Tst of the pedestal ST thicker than the thickness Tw of the wafer W to be measured (in one example, Tst ≥ 3 × Tw). Thereby, the influence of the heat of the wafer W on the environment (for example, temperature) in the measurement chamber 112 can be suppressed.

[0360] As Figure 31 shown, at the time of wafer-level inspection, a test head 70 is mounted on the measurement unit 100 of the inspection apparatus 1D.

[0361] A probe card 72 is provided at a position facing the pedestal ST and is disposed substantially parallel to the holding surface of the pedestal ST. A plurality of probes 74 are formed on the surface of the probe card 72 facing the pedestal ST. The probe card 72 is connected to the tester main body via the test head 70.

[0362] A plurality of chips C are formed on the wafer W, and each chip C includes one or more electrode pads P. By moving the pedestal ST in the XYZ directions or rotating it in the θ direction by the pedestal moving mechanism 102, alignment between the wafer W and the probe card 72 is performed so that each probe 74 touches the corresponding electrode pad P.

[0363] After the alignment and contact between the probe 74 and the electrode pad P are performed by the inspection device 1D, an electrical signal is sent from the tester main body to the chip C via the test head 70, the probe card 72, and the probe 74, and the electrical characteristics of the chip C on the wafer W are inspected (wafer-level inspection). The inspection result of the electrical characteristics is output in a form that can be confirmed by the operator through the input / output unit 12 (refer to Figure 32 ).

[0364] After the inspection of the electrical characteristics of the chip C on the wafer W is completed, the wafer W is transported and recovered from the inspection device 1D to the loading unit 200 by the transfer unit.

[0365] As Figure 30 shown, when inspecting the electrode pad P of the wafer W, the 3D shape measuring machine 52 is installed in the measuring unit 100 of the inspection device 1D. Moreover, the traces formed on the electrode pad P in the wafer-level inspection are sequentially detected by the 3D shape measuring machine 52, and the quality of the traces formed on the electrode pad P is determined.

[0366] It should be noted that in the present embodiment, the 2D camera 50 and the 3D shape measuring machine 52 are installed separately, but it is not limited thereto. For example, it may be configured to be able to switch between the 2D camera 50 and the 3D shape measuring machine 52 through a switching mechanism.

[0367] In addition, it is sufficient that the test head 70, the 2D camera 50, the 3D shape measuring machine 52, etc. can move relative to the pedestal ST, and it may also be configured to be able to move the test head 70, the 2D camera 50, the 3D shape measuring machine 52, etc. relative to the pedestal ST.

[0368] (Control System of Inspection Device)

[0369] Figure 32 is a block diagram showing the control system of the inspection device according to the fifth embodiment of the present invention.

[0370] As Figure 32 shown, the inspection device 1D according to the present embodiment includes a control unit 10, an input / output unit 12, a transfer unit drive unit 14, a transfer arm drive unit 16, and a measurement control unit 18.

[0371] The control unit 10 includes a processor (e.g., CPU (Central Processing Unit), MPU (MicroProcessor Unit), etc.), ROM (Read Only Memory), RAM (Random Access Memory), and a memory device (e.g., HDD (Hard Disk Drive) or SSD (Solid State Drive), etc.). In the control unit 10, the functions of each part of the inspection device 1D are realized by the processor executing various programs such as a control program stored in the memory device.

[0372] The input / output unit 12 includes a display unit (e.g., a liquid crystal display) for displaying a GUI (Graphical User Interface) for operating the inspection device 1D, and an operation unit (e.g., a touch panel, a keyboard, a pointing device, etc.) for receiving operation inputs from an operator.

[0373] The transfer unit drive unit 14 includes a motor or the like for moving the transfer unit 202 in the XYZ directions and rotating it in the θ direction (around the Z direction) within the loading unit 200.

[0374] The transfer arm drive unit 16 includes a motor for extending and retracting the transfer arm 204 mounted on the transfer unit 202 in its longitudinal direction, and a control valve or the like for adsorbing the wafer W to the adsorption holes of the transfer arm 204. This control valve is connected to a vacuum component (pump) provided at the installation site of the inspection device 1D.

[0375] The shutter drive unit 30 includes a shutter 120 on the measurement unit 100 side and a motor or the like for opening and closing the shutter 220 on the loading unit 200 side. When transferring the wafer W between the measurement unit 100 and the loading unit 200, the shutters 120 and 220 are opened, and the shutters 120 and 220 are closed except during transfer.

[0376] The fan drive unit 32 includes a motor or the like for driving the fan 130 in the measurement chamber 112. In addition, when the fan shutter 132 is electrically operated, the fan drive unit 32 includes a motor or the like for opening and closing the fan shutter 132. The fan 130 stops when the electrode pad P is inspected by the 3D shape measuring machine 52, and in other cases, for example, when temperature unevenness is detected by a temperature sensor in the measurement chamber 112, the air in the measurement chamber 112 can be circulated as needed by the fan 130.

[0377] The control unit 10 controls the opening and closing of the baffles 120 and 220 through the baffle drive unit 30. In addition, the control unit 10 controls the transfer unit 202 and the transfer arm 204 respectively by using the transfer unit drive unit 14 and the transfer arm drive unit 16 to take out the wafer W from a plurality of wafer cassettes or to transfer the wafer W into and out of a plurality of measurement units 100.

[0378] In addition, the control unit 10 may obtain the measurement result of the temperature in the preparation chamber 212 measured by the temperature detection unit 234 and control the temperature adjustment unit 232 based on the measurement result.

[0379] The alignment camera 54 is a device for detecting the front end position of the probe 74 and is provided on the stage ST, for example. The control unit 10 performs alignment between the probe 74 and the electrode pad P based on the detection result of the front end position of the probe 74 and the detection result of the electrode pad P detected by the 2D camera 50.

[0380] The measurement control unit 18 performs drive control of the test head 70 for inspecting the wafer W provided in the measurement unit 100, shooting control of the 2D camera 50, measurement control of the 3D shape measuring machine 52, and shooting control of the alignment camera 54 according to the control signal from the control unit 10. It should be noted that, as the test head 70 and the 2D camera 50, for example, the technologies described in Japanese Patent Laid-Open No. 2019-102591 can be used.

[0381] According to the present embodiment, by surrounding the measurement chamber 112 with the light-shielding partition wall 110, the influence of external interference on the inside of the measurement chamber 112 can be minimized, and the reduction in the inspection accuracy of the three-dimensional shape caused by air disturbance can be suppressed.

[0382] [Modification Example 1 of the Fifth Embodiment]

[0383] Figure 33 It is a diagram (during wafer-level inspection) showing the inspection device according to Modification Example 1 of the fifth embodiment. In the following description, for the structures common or similar to those of the above embodiments, the same reference numerals or reference numerals with suffixes are used and the description is omitted.

[0384] As Figure 33 As shown, in the inspection device 1E according to Modification Example 1, when the 3D shape measuring machine 52 is installed in the measurement unit 100, a cover 150 having a rectangular parallelepiped or cylindrical shape covers the 3D shape measuring machine 52 to cover the 3D shape measuring machine 52. The cover 150 is also formed of a material with high light-shielding property like the partition walls 110 and 210. In addition, the cover 150 may include a material with high heat insulation (low thermal conductivity) like the partition walls 110 and 210.

[0385] AsFigure 33 As shown, the 3D shape measuring machine 52 is installed in a space separated from the outside of the cover 150. The cover 150 has a function of separating the air environments inside and outside thereof. That is, by providing the cover 150, the influence of external disturbances (for example, noise, temperature, vibration, etc.) occurring outside is suppressed.

[0386] The cover 150 has sound insulation performance (vibration-proof performance) in the same manner as the partition walls 110 and 210. As a structure for realizing the sound insulation performance of the cover 150, for example, a structure in which a sound-absorbing material is put into the internal structure of the cover 150, or a structure made such that the resonance frequency of the cover 150 itself is higher than the frequency at which vibration is caused by noise can be cited. This frequency may also depend on the surrounding environment, and in one example, it is preferably 100 to 200 Hz or more.

[0387] Generally, in a semiconductor manufacturing factory, noise is generated from air conditioners and other production equipment, and the level of this noise sometimes exceeds 70 dB. When this noise reaches the 3D shape measuring machine 52, it becomes vibration. When the 3D shape measuring machine 52 vibrates during measurement, the relative distance between the 3D shape measuring machine 52 and the wafer W changes, and a measurement error may occur in the height direction (Z direction) of the inspection object on the wafer W. Thus, vibration generated from air conditioners and other production equipment may also be a cause of measurement error.

[0388] In addition, in a device of the type using a white light interference microscope or focus change in the 3D shape measuring machine 52, vibration may also be transmitted between the scale on the scanning axis and the scale head. In this type of device, generally, shooting is performed according to a trigger signal, which is output according to the reading position of the scale. Therefore, when vibration is transmitted, the maximum frame rate of the imaging unit included in the device may be exceeded, resulting in frame loss. Such frame loss may also be a cause of measurement error.

[0389] In the present embodiment, by the cover 150 having sound insulation performance, it is possible to prevent a decrease in measurement accuracy caused by vibration as described above.

[0390] Furthermore, in the present embodiment, it is possible to suppress the influence of radiant heat from the outside on the 3D shape measuring machine 52 and its support members and the like by the cover 150. Moreover, it is possible to suppress a decrease in measurement accuracy due to deformation (thermal displacement) of the support members and the like caused by temperature change or a thermal influence on the measurement optical system of the 3D shape measuring machine 52.

[0391] [Modification Example 2 of the Fifth Embodiment]

[0392] Figure 34 It is a diagram showing an inspection apparatus according to Modification Example 2 of the fifth embodiment (during wafer-level inspection).

[0393] AsFigure 34 As shown, in the inspection apparatus 1F according to the second modification, during wafer-level inspection, a transparent member 160 (for example, embedded) is mounted in the opening above the measurement unit 100, and the 3D shape measurement machine 52 inspects the electrode pads P of the wafer W from the outside of the measurement chamber 112. Here, the transparent member 160 may also include a material with high heat insulation (low thermal conductivity). It should be noted that when the test head 70 is mounted, the transparent member 160 is removed, and the opening above the measurement unit 100 is opened.

[0394] The influence of radiant heat from the outside on the 3D shape measurement machine 52 and its support members can be suppressed by this transparent member 160. Moreover, a reduction in measurement accuracy due to deformation (thermal displacement) of the support members or the like caused by temperature changes, or the thermal influence on the measurement optical system of the 3D shape measurement machine 52, can be suppressed.

[0395] [Modification 3 of the Fifth Embodiment]

[0396] Figure 35 It is a diagram showing the test head 70 and the 3D shape measurement machine 52 in the inspection apparatus according to the third modification of the fifth embodiment. Figure 35 The upper diagram is a plan view when observed from the +Z side, Figure 35 The lower diagram is a side view when observed from the -Y side.

[0397] As Figure 35 shown, the third modification is obtained by sharing the shape of the mounting portion when the test head 70 and the 3D shape measurement machine 52 are mounted on the measurement unit 100.

[0398] As Figure 35 shown, on the partition wall 110 on the upper surface of the measurement unit 100, a mounting portion 110A for mounting the test head 70 and the 3D shape measurement machine 52 is formed.

[0399] The mounting portion 72A of the test head 70 and the mounting portion 52A of the 3D shape measurement machine 52 have a substantially merged shape when observed in plan (when observed from the Z direction), and are shaped so as to be mountable (fitted) in the mounting portion 110A. The mounting portions 110A, 72A, and 52A are examples of the first to third mounting portions, respectively.

[0400] It should be noted that in Figure 35In the example shown, the mounting portion 110A has the shape of a female portion in the shape of a dovetail (i.e., a shape with an extended front end), and the mounting portions 72A of the test head 70 and 52A of the 3D shape measuring machine 52 have the shape of male portions in the shape of a dovetail, but the shape of the mounting portion is not limited thereto. For example, in addition to the above-described fitting structure, auxiliary fixing tools such as screws or joints may be used to assist in fixing between the partition wall 110 and the test head 70 or between the partition wall 110 and the 3D shape measuring machine 52. The mounting portions 72A and 52A only need to be shapes that can be mounted on the mounting portion 110A. For example, they may be concave-convex shapes, or shapes of dovetail joints where the mounting portions 72A and 52A and the mounting portion 110A cut off a part of each other, or dovetail-shaped joints, etc.

[0401] According to Modification 3, the installation and replacement of the test head 70 and the 3D shape measuring machine 52 with respect to the measurement unit 100 become easy.

[0402] In addition, the relationship between the installation positions of the test head 70 and the 3D shape measuring machine 52 depends on the mounting portion. Therefore, for example, after wafer-level inspection, information related to the position of the measurement field of view of the 3D shape measuring machine 52 can be obtained. That is, information (detection information) related to the location detected in the previously performed wafer-level inspection is easily obtained, and information related to electrical characteristics (for example, which electrode pad P has an abnormal electrical characteristic, etc.) can also be utilized.

[0403] According to Modification 3, since the partition wall 110 on the upper surface of the measurement unit 100 and the test head 70 and the 3D shape measuring machine 52 are set to a fitting structure, the reproducibility of the installation can be ensured. Therefore, when installing the 3D shape measuring machine 52, it becomes easy to correct the mutual positional relationship between the installed 3D shape measuring machine 52 and the 2D camera 50. In addition, the positional accuracy required between the 3D shape measuring machine 52 and the 2D camera 50 varies depending on each measurement object, but there are also cases where correction of the positional relationship between the two is not required depending on the required positional accuracy. On the other hand, when installing the test head 70, it also becomes easy to correct the mutual positional relationship between the installed test head 70 and the 2D camera 50 (for example, being accommodated within the field of view of the 2D camera 50), and there are also cases where correction of the positional relationship between the two is not required depending on the required positional accuracy.

[0404] [Inspection method according to the fifth embodiment]

[0405] Figure 36 It is a flowchart showing the inspection method according to the fifth embodiment of the present invention.

[0406] First, before starting the inspection, the baffle 120 on the measurement unit 100 side and the baffle 220 on the loading unit 200 side are both closed.

[0407] The wafer storage cassette 230 (e.g., a batch of N wafers W) is placed in the preparation chamber 212 of the loading unit 200 (step S300), and the inspection of a batch of wafers W is started. Regarding the start instruction of the inspection, it can also be manually instructed via the measurement start button of the input / output unit 12, etc., or the inspection can be automatically started when the wafer storage cassette 230 is placed and the adjacent 210 of the loading unit 200 is closed.

[0408] Next, the temperature in the preparation chamber 212 is controlled by the temperature adjustment unit 232 and the temperature detection unit 234. Then, standby is performed until the temperature of the wafer W in the preparation chamber 212 reaches a specified inspection temperature (the same temperature as the measurement chamber 112. For example, the temperature of the measurement chamber 112 ± 2°C) (step S302).

[0409] It should be noted that in step S302, the temperature in the preparation chamber 212 is actually detected and standby is performed, but the present disclosure is not limited thereto. For example, the following program can also be performed, that is, the control unit 10 is made to act so as to automatically move to step S304 after a specified time has elapsed since the start of the inspection. The specified time in this case can be experimentally or empirically determined based on data such as the temperature change after the adjacent 210 of the loading unit 200 is closed or after the operation of the temperature adjustment unit 232 starts.

[0410] Next, the parameter i of the number of wafers W to be inspected is set to i = 1 (step S304), and the wafer-level inspection and the inspection (good / bad determination) of the electrode pads P are sequentially performed for the wafer W1. When performing the wafer-level inspection, the test head 70 is mounted on the measurement unit 100. Then, the baffle 120 on the measurement unit 100 side and the baffle 220 on the loading unit 200 side are opened, and the first wafer W1 is loaded on the pedestal ST (step S306). After loading the wafer W1, the baffles 120 and 220 are closed, and the measurement chamber 112 is isolated from the outside and the loading unit 200 to suppress the influence of external interference from the measurement chamber 112 and the outside of the loading unit 200.

[0411] Next, the wafer-level inspection of the wafer W1 is performed by the test head 70 (step S308). The result of the wafer-level inspection is output to the control unit 10.

[0412] After the wafer-level inspection, the good / bad determination of the electrode pads P is performed using the 3D shape measuring machine 52 (step S310). During the shape measurement of the electrode pads P using the 3D shape measuring machine 52 in step S310, the operation of the fan 130 stops and the fan baffle 132 is closed. In addition, the baffles 120 and 220 remain closed.

[0413] When the wafer-level inspection (step S308) of the wafer W1 and the inspection of the electrode pads P (step S310) are completed, the shutter 120 on the measurement unit 100 side and the shutter 220 on the loading unit 200 side are opened, and the wafer W1 is unloaded from the pedestal ST (step S312). After unloading the wafer W1, the shutters 120 and 220 are closed.

[0414] Next, the parameter i of the number of wafers W is set to i = i + 1 (No in step S314, step S316), and the wafer-level inspection (step S308) and the inspection of the electrode pads P (step S310) are performed on the next wafer W2. It should be noted that the unloading of the wafer W1 and the loading of the wafer W2 can also be performed in parallel. In this case, after the unloading of the wafer W1 and the loading of the wafer W2 are both completed, the shutters 120 and 220 can be closed.

[0415] Steps S306 to S316 are repeated. When the wafer-level inspection (step S308) and the inspection of the electrode pads P (step S310) of the wafers Wi in a batch to be inspected are completed (Yes in step S314), the wafer cassette 230 of the loading unit 200 is replaced (step S318), and the inspection of the next batch is performed (steps S302 to S316). Then, when the inspections of all groups of inspection objects are completed (Yes in step S320), the inspection process ends.

[0416] According to the present embodiment, the measurement chamber 112 is surrounded by the light-shielding partition wall 110, and the opening of the shutters 120 and 220 is limited to the loading and unloading of the wafers Wi. Thus, the influence of external interference on the inside of the measurement chamber 112 can be minimized, and a decrease in the inspection accuracy of the three-dimensional shape due to air disturbance can be suppressed.

[0417] It should be noted that, in the present embodiment, the inspection object is the stitch M formed on the electrode pad P, but as described above, the present disclosure is not limited thereto. For example, the present embodiment can also be applied to an appearance inspection for detecting inspection objects such as scratches or foreign matters on the wafer W.

[0418] For example, also in the case where the inspection object is a scratch on the wafer W, when at least one characteristic amount among the size of the scratch (for example, the maximum size or the minimum size), the depth of the scratch (for example, the maximum valley depth Sv or the maximum height Sz), the area of the scratch (for example, the ratio of the area occupied by the scratch in the unit area of the wafer W), the configuration of the scratch (for example, the number per unit area, etc.) exceeds a reference value, the wafer W may be determined to be abnormal. In addition, instead of or in addition to the above characteristic amounts, when the distance between the scratch and the device is equal to or less than the reference value, the wafer W may be determined to be abnormal.

[0419] In addition, when the object to be inspected is a foreign object, for example, when at least one characteristic quantity among the size of the foreign object (e.g., the maximum size or the minimum size), the arrangement of the foreign objects (e.g., the number per unit area, etc.) exceeds a reference value, the wafer W may be determined to be abnormal. In addition, instead of or in addition to the above characteristic quantities, the quality of the wafer W may be determined based on the type of the foreign object. For example, when it is presumed based on the three-dimensional shape of the foreign object that the foreign object is a foreign object that can be easily removed by air or the like, the wafer W may be determined to be normal regardless of the above characteristic quantities.

[0420] Description of Reference Numerals

[0421] 1, 1A to 1F... inspection device, 10... control unit, 12... input / output unit, 14... transfer unit drive unit, 16... transfer arm drive unit, 18... measurement control unit, 20... measurement unit, 50... 2D camera, 52... 3D shape measurement machine, 54... alignment camera, 70... test head, 100... measurement unit, 110... partition wall, 112... measurement chamber, 120... baffle, 150... cover, 160... transparent member, 200... loading unit, 210... partition wall, 212... preparation chamber, 220... baffle.

Claims

1. An inspection device, wherein, the inspection device includes: a camera that captures an image of an object to be inspected on a wafer; a first determination unit that detects the object to be inspected based on the image captured by the camera and makes a provisional determination of the quality of the object to be inspected; a three-dimensional shape measuring machine that measures the three-dimensional shape of the object to be inspected determined to be abnormal through the provisional determination; and a second determination unit that makes a formal determination of the quality of the object to be inspected 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 based on the three-dimensional shape of the object to be inspected measured by the three-dimensional shape measuring machine.

2. The inspection device according to claim 1, wherein, the object to be inspected is a stitch of an electrode pad formed on the wafer when the wafer is electrically inspected using a test head.

3. The inspection device according to claim 2, wherein, the first determination unit detects the area of the stitch formed on the electrode pad based on the image captured by the camera and makes a provisional determination of the quality of the electrode pad based on the area.

4. The inspection device according to claim 2 or 3, wherein, the second determination unit makes a formal determination of the quality of the electrode pad based on the maximum valley depth of the electrode pad measured by the three-dimensional shape measuring machine.

5. The inspection device according to any one of claims 1 to 4, wherein, the inspection device includes an alignment unit that obtains the positional relationship between the camera and the three-dimensional shape measuring machine.

6. The inspection device according to claim 5, wherein, the alignment unit obtains the positional relationship between the camera and the three-dimensional shape measuring machine based on the measurement results of alignment marks measured by the camera and the three-dimensional shape measuring machine.

7. An inspection method, wherein, the inspection method includes the following steps: capturing an image of an object to be inspected on a wafer by a camera, detecting the object to be inspected based on the image, and making a provisional determination of the quality of the object to be inspected; and measuring the three-dimensional shape of the object to be inspected determined to be abnormal through the provisional determination by a three-dimensional shape measuring machine, and making a formal determination of the quality of the object to be inspected 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 based on the three-dimensional shape of the object to be inspected measured by the three-dimensional shape measuring machine.

8. The inspection method according to claim 7, wherein, the object to be inspected is a stitch of an electrode pad formed on the wafer when the wafer is electrically inspected using a test head.

9. The inspection method according to claim 7 or 8, wherein, the inspection method includes an alignment step in which the positional relationship between the camera and the three-dimensional shape measuring machine is obtained.

10. The inspection method according to claim 9, wherein, the inspection method includes the following steps: measuring an alignment mark by the camera; and The alignment mark is measured by the three-dimensional shape measuring machine. In the alignment step, based on the measurement results of the alignment mark measured by the camera and the three-dimensional shape measuring machine, the positional relationship between the camera and the three-dimensional shape measuring machine is obtained.

11. An inspection device, wherein the inspection device includes: a three-dimensional shape measuring machine that measures the three-dimensional shape of an inspection object on a wafer; and a calculation unit that calculates the measurement cost required for measuring the inspection object on the wafer based on inspection object configuration information related to the configuration of the inspection object and the size of the measurement field of view of the three-dimensional shape measuring machine.

12. The inspection device according to claim 11, wherein the inspection device includes a selection unit that outputs the measurement cost calculated by the calculation unit and selects the size of the measurement field of view when inspecting the inspection object according to an operation input from an operator.

13. The inspection device according to claim 11, wherein the calculation unit calculates the measurement cost for each size of the measurement field of view based on the inspection object configuration information, and selects the size of the measurement field of view for which the measurement cost meets a set criterion.

14. The inspection device according to any one of claims 11 to 13, wherein the measurement cost includes information related to the scanning speed when scanning the wafer and the three-dimensional shape measuring machine in the height direction, and the narrower the measurement field of view of the three-dimensional shape measuring machine, the greater the calculated value of the scanning speed by the calculation unit.

15. The inspection device according to any one of claims 11 to 14, wherein the measurement cost includes information related to the measurement time required for measuring the inspection object on the wafer, and the narrower the measurement field of view of the three-dimensional shape measuring machine, or the more the number of inspection objects that can be included in the measurement field of view, the smaller the calculated value of the measurement time by the calculation unit.

16. The inspection device according to any one of claims 11 to 15, wherein the inspection device includes a measurement field of view moving unit that moves the measurement field of view when inspecting the inspection object formed on the wafer so that the inspected inspection object is not included in the measurement field of view.

17. The inspection device according to any one of claims 11 to 16, wherein the inspection object is a stitch of an electrode pad formed on the wafer when the wafer is electrically inspected using a test head.

18. An inspection method, wherein the inspection method includes the following steps: calculating the measurement cost required for measuring the inspection object on the wafer based on inspection object configuration information related to the configuration of the inspection object on the wafer and the size of the measurement field of view of a three-dimensional shape measuring machine; and setting the calculated size of the measurement field of view for the three-dimensional shape measuring machine.

19. An inspection device, wherein the inspection device includes: a measuring unit having a measuring chamber surrounded by a partition wall for separating an inner air environment from an outer air environment; and A three-dimensional shape measuring machine is detachable from a first opening provided in a wall adjacent to the measuring unit and measures the three-dimensional shape of the wafer inspection object in the measuring chamber in a non-contact manner.

20. The inspection device according to claim 19, wherein: The partition wall of the measurement chamber has at least one of light shielding property and vibration proof property.

21. The inspection device according to claim 19 or 20, wherein: The inspection device includes a first baffle plate provided at a second opening provided in a wall adjacent to the measuring unit. The wafer is carried in and out of the measurement chamber through the second opening.

22. The inspection device according to any one of claims 19 to 21, wherein: The inspection device includes a cover that covers the three-dimensional shape measuring machine when the three-dimensional shape measuring machine is attached to the measuring unit and that separates the inside and outside air environments.

23. The inspection device according to claim 22, wherein: The cover has at least one of light shielding property and vibration proof property.

24. The inspection device according to any one of claims 19 to 21, wherein: The inspection device includes a transparent member that can be mounted on the first opening. The three-dimensional shape measuring machine measures the inspection object in the measurement chamber via the transparent member.

25. The inspection device according to any one of claims 19 to 24, wherein: The inspection device comprises: a fan mounted on a third opening provided in a wall adjacent to the measuring unit and configured to circulate air in the measuring chamber; and The fan baffle is used to open and close the third opening.

26. The inspection device according to any one of claims 19 to 25, wherein: The inspection device comprises: A loading section having a preparation room surrounded by a partition wall for separating an inner air environment from an outer air environment; as well as a second baffle plate provided at an opening provided in a partition wall of the loading portion, The wafer is carried in and out of the preparation room through the opening of the loading unit.

27. The inspection device according to claim 26, wherein: The partition wall of the preparation room has at least one of light shielding property and vibration-proof property.

28. The inspection device according to any one of claims 19 to 27, wherein: The inspection device includes a test head that is attachable to and detachable from the first opening of the measurement unit. The inspection object is a needle trace formed on an electrode pad when the wafer is electrically inspected using the test head.

29. The inspection device according to claim 28, wherein: The inspection device comprises: a first mounting portion formed on the partition wall of the measuring unit; a second mounting portion formed on the test head and formed into a shape capable of being mounted on the first mounting portion; as well as A third mounting portion is formed on the three-dimensional shape measuring machine and is formed in a shape that can be mounted on the first mounting portion.

30. The inspection device according to claim 29, wherein: The second mounting portion and the third mounting portion are formed in a shape capable of being fitted into the first mounting portion.

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