Diagnostic device, diagnostic method, and needle mark inspection device

Abstract

To provide a diagnostic device, a diagnostic method, and a needle mark inspection device that can objectively grasp the status of an inspection device and easily identify the cause of abnormalities.SOLUTION: A diagnostic device (diagnostic processing unit 116) is a device that diagnoses the state of an inspection device that inspects electrical characteristics by contacting probe needles of a probe card with the electrode pads of each chip formed on a wafer, and is equipped with a shape data acquisition unit 120 that acquires three-dimensional shape data of the surface of the electrode pad after inspection, a detection processing unit that detects needle mark position data that indicates the position of the probe needle mark formed on the electrode pad based on the three-dimensional shape data, a diagnostic processing unit that generates diagnostic information for diagnosing whether or not there is an abnormality in the inspection device based on the needle mark position data, and a diagnostic information output unit that outputs the diagnostic information.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a diagnostic device and diagnostic method for diagnosing the state of an inspection device, and a needle mark inspection device. [Background technology]

[0002] The semiconductor manufacturing process involves many steps, and various inspections are performed at each step to ensure quality and improve yield. For example, wafer-level inspection is performed after multiple semiconductor chips (hereinafter referred to as "chips") are formed on a semiconductor wafer (hereinafter referred to as "wafer").

[0003] Wafer-level testing is performed using a testing device (prober) that contacts the electrode pads of each chip with numerous needle-shaped probes (hereinafter referred to as "probe needles") formed on a probe card. The probe needles are electrically connected to terminals on a test head, and the test head supplies power and test signals to each chip via the probe needles, while the test head detects output signals from each chip to measure whether they are operating normally.

[0004] After such wafer-level inspection is performed, a technique has been disclosed in which the needle marks formed on the electrode pads are imaged by a camera and the needle marks on the electrode pads are detected from the image in order to determine whether the probe needles have made normal contact with the electrode pads (see, for example, Patent Document 1).

[0005] In addition, in wafer-level inspection, it is ideal to scrape off only the oxide film on the surface of the electrode pad with a probe needle and then contact the probe needle with the electrode pad to establish electrical continuity. For this purpose, a technology has been disclosed in which, as a preliminary step before wafer-level inspection, the tips of multiple probes are detected by a camera (probe position detection camera) and the height of each probe tip is detected to detect the tilt of the probe card (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-289818 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-71824 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the technology disclosed in Patent Document 1 is merely a technology for detecting needle marks on electrode pads to determine whether or not the probe needles have made normal contact with the electrode pads, and even if the probe card is tilted in the inspection device, it cannot detect poor contact due to the tilt.

[0008] Furthermore, in wafer-level testing, contact failures between the probe needles and the electrode pads can occur not only when the probe card is tilted, but also when the stage (wafer chuck) on which the wafer is placed is at fault. Therefore, although the technology disclosed in Patent Document 2 can detect the tilt of the probe card, it cannot detect contact failures caused by the tilt when the stage is tilted.

[0009] Furthermore, heat generated by motors and friction builds up inside the inspection equipment, deforming guides and other components, which can lead to deterioration in the straightness of the stage's moving axis and worsening pitching or yawing. Therefore, inspection equipment is generally equipped with air intakes and fans to avoid the adverse effects of heat, but if cooling is insufficient due to the ambient temperature environment, or if dust is introduced from outside and gets caught in the guides, the stage's straightness, pitching, yawing, or rolling can deteriorate. Continuing to perform wafer-level inspection under these conditions can result in the continued production of defective chips.

[0010] Furthermore, a probe card may have, for example, approximately 1,000 probe needles, and even if the load per probe during contact is only a few grams, the total load will be several kilograms. As a result, an uneven load occurs on the stage due to contact, which can cause the stage to tilt relative to the probe card, resulting in poor contact.

[0011] The present invention has been made in view of the above circumstances, and aims to provide a diagnostic device, diagnostic method, and needle mark inspection device that can objectively grasp the state of the inspection device and easily identify the cause of an abnormality. [Means for solving the problem]

[0012] In order to achieve the above object, the present invention comprises the following aspects.

[0013] The diagnostic device according to the first aspect is a diagnostic device that diagnoses the state of an inspection device, and the inspection device has a probe card with probe needles and a movable stage on which a wafer is placed, and is an apparatus that inspects electrical characteristics by contacting the probe needles with the electrode pads of each chip formed on the wafer, and the diagnostic device includes a three-dimensional data acquisition unit that acquires three-dimensional shape data of the surface of the electrode pad after inspection, a detection processing unit that detects needle mark position data that indicates the position of the probe needle mark formed on the electrode pad based on the three-dimensional shape data, a diagnostic processing unit that generates diagnostic information for diagnosing whether or not there is an abnormality in the inspection device based on the needle mark position data, and a diagnostic information output unit that outputs the diagnostic information.

[0014] In the diagnostic device of the second aspect, in the first aspect, the diagnostic information is map information that associates each position in at least a portion of the area within the surface of the wafer with probe trace information that represents the state of the probe trace corresponding to each position.

[0015] In the diagnostic device according to a third aspect, in addition to the first aspect, the diagnostic information includes tilt information indicating a relative tilt between the probe card and the stage.

[0016] In the diagnostic device of the fourth aspect, in the first aspect, the diagnostic processing unit obtains an approximate plane relative to the height position of the lower end of the probe needle mark formed on each electrode pad, and detects the relative inclination between the probe card and the stage based on the direction of the normal vector of the approximate plane.

[0017] A diagnostic device according to a fifth aspect is based on the first aspect, wherein the diagnostic information includes straightness information indicating the straightness of the stage.

[0018] A diagnostic device according to a sixth aspect is based on the first aspect, wherein the diagnostic information includes rotational deviation information indicating a rotational deviation of the stage.

[0019] In the diagnostic device according to the seventh aspect, in any one of the first to sixth aspects, the diagnostic information output unit has a function of sending a notification or instruction to the testing device to stop the test based on the diagnostic information.

[0020] A diagnostic method according to an eighth aspect is a diagnostic method for diagnosing the state of an inspection device, the inspection device having a probe card with probe needles and a movable stage on which a wafer is placed, and which inspects electrical characteristics by contacting the probe needles with the electrode pads of each chip formed on the wafer, and the diagnostic method includes a three-dimensional data acquisition step for acquiring three-dimensional shape data of the surface of the electrode pad after inspection, a detection processing step for detecting needle mark position data indicating the position of the probe needle mark formed on the electrode pad based on the three-dimensional shape data, a diagnostic processing step for generating diagnostic information for diagnosing whether or not there is an abnormality in the inspection device based on the needle mark position data, and a diagnostic information output step for outputting the diagnostic information.

[0021] A needle mark inspection device according to a ninth aspect is a needle mark inspection device that inspects probe needle marks formed on the electrode pads of each chip formed on a wafer, and includes a shape data acquisition unit that acquires three-dimensional shape data of the surface of the electrode pad, a detection processing unit that detects needle mark position data indicating the position of the probe needle mark based on the three-dimensional shape data, a diagnostic processing unit that generates diagnostic information for diagnosing whether or not there is an abnormality in the probe needle mark based on the needle mark position data, and a diagnostic information output unit that outputs the diagnostic information. [Effects of the Invention]

[0022] According to the present invention, the state of the inspection device can be objectively grasped, and the cause of the abnormality can be easily identified. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a schematic diagram showing the configuration of an inspection system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a plan view showing an example of a wafer. [Figure 3] FIG. 1 is an enlarged plan view of a chip after wafer-level inspection. [Figure 4] FIG. 2 is a schematic diagram illustrating a state in which measurement is performed by a coordinate measuring machine in the inspection device. [Figure 5] FIG. 1 is a schematic diagram illustrating a three-dimensional measuring machine. [Figure 6] FIG. 2 is a functional block diagram of a control device. [Figure 7] FIG. 2 is an explanatory diagram for explaining a detection process executed by a detection processing unit. [Figure 8] FIG. 2 is an explanatory diagram for explaining a detection process executed by a detection processing unit. [Figure 9] FIG. 2 is an explanatory diagram for explaining a detection process executed by a detection processing unit. [Figure 10] FIG. 2 is an explanatory diagram for explaining a detection process executed by a detection processing unit. [Figure 11] FIG. 2 is an explanatory diagram for explaining a detection process executed by a detection processing unit. [Figure 12] FIG. 2 is an explanatory diagram for explaining a detection process executed by a detection processing unit. [Figure 13] FIG. 10 is a diagram showing an example of a needle trace map. [Figure 14] FIG. 10 is an enlarged view of a portion of the needle trace map. [Figure 15] FIG. 10 is an enlarged view of a portion of the needle trace map. [Figure 16] 10 is a flowchart illustrating an example of a diagnostic method performed by a diagnostic processing unit. [Figure 17] FIG. 10 is a schematic diagram showing the configuration of an inspection system according to another embodiment 1. [Figure 18] FIG. 10 is a schematic diagram showing the configuration of an inspection system according to another embodiment 2. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0025] [Present embodiment] [Inspection system] FIG. 1 is a schematic diagram showing the configuration of an inspection system 1 according to this embodiment. As shown in FIG. 1, the inspection system 1 according to this embodiment includes an inspection device 10 and a control device 100. The inspection device 10 (prober device) inspects (wafer-level inspection) the electrical characteristics of each chip formed on a wafer W. In FIG. 1, the X, Y, and Z directions are perpendicular to one another, the X direction is the horizontal direction, the Y direction is the horizontal direction perpendicular to the X direction, and the Z direction is the vertical direction. This also applies to the other figures described below.

[0026] [Inspection equipment] As shown in FIG. 1, the inspection device 10 includes a housing 12, a stage 16, a stage moving mechanism 18, a probe card 20, a test head 26, and a coordinate measuring machine 30.

[0027] The housing 12 is configured in a rectangular parallelepiped (box-like) shape, and has an inspection space 14 therein for inspecting the wafer W. A movable stage 16 on which the wafer W is placed is housed within the inspection space 14. A probe card 20 and a three-dimensional measuring machine 30 are provided on the top surface (upper face) of the housing 12.

[0028] The stage 16 has a holding surface (suction surface) capable of suction-holding the wafer W. The stage movement mechanism 18 supports the underside of the stage 16 (the surface opposite to the holding surface). The stage movement mechanism 18 is configured to be movable in the X, Y, and Z directions and rotatable in the θ direction (a rotational direction around the Z direction). As a result, the wafer W suction-held on the holding surface of the stage 16 can be moved in the X, Y, and Z directions and rotated in the θ direction together with the stage 16 by the stage movement mechanism 18.

[0029] The probe card 20 is replaceably attached to the top surface of the housing 12, and is provided in a position facing the stage 16. The probe card 20 has a plurality of probe needles 22 on the surface facing the stage 16. Each probe needle 22 is arranged corresponding to the arrangement of the electrode pads of the chip to be inspected.

[0030] The test head 26 is disposed outside the housing 12 at a position above the probe card 20. The test head 26 is electrically connected to the probe card 20 via an interface 24. The test head 26 supplies power and test signals to each chip via the probe needles 22, and detects output signals from each chip to measure whether it is operating normally.

[0031] Fig. 2 is a plan view showing an example of a wafer W. As shown in Fig. 2, a plurality of chips C are formed on the wafer W. Furthermore, a plurality of electrode pads P are formed on each of the chips C.

[0032] During wafer-level inspection, under the control of the control device 100, the wafer W placed on the stage 16 and the probe card 20 are aligned relative to each other, and then each probe needle 22 of the probe card 20 is brought into contact with the electrode pad P of the chip C to be inspected. Then, in this state, power and a test signal are supplied from the test head 26 to each chip C via the probe needles 22, and the output signal from each chip C is detected by the test head 26 to measure whether it is operating normally. This operation is repeated by sequentially changing the chip C to be inspected within the wafer W until inspection of all chips C is completed.

[0033] 3 is an enlarged plan view of the chip C after the wafer-level inspection. As shown in FIG. 3, after the wafer-level inspection, probe needle marks M formed by contact with the probe needles 22 remain on the surfaces of the electrode pads P of the chip C.

[0034] 4 is a schematic diagram showing the state when measurement is performed by the coordinate measuring machine 30 in the inspection device 10. As shown in Fig. 4, the measurement of the three-dimensional shape of the surface of the electrode pad P is performed in a state where the stage 16 on which the wafer W is placed after the wafer-level inspection has been moved to a position facing the coordinate measuring machine 30.

[0035] The coordinate measuring machine 30 is attached to the top surface of the housing 12 via an elevation mechanism 32. The coordinate measuring machine 30 is a device that measures the three-dimensional shape of the surface of the electrode pad P, including the probe needle mark M, in a non-contact manner. In this embodiment, a surface shape measuring device that uses white light interferometry to three-dimensionally measure the surface shape of the measurement surface (electrode pad P on the wafer W) in a non-contact manner is suitably used as the coordinate measuring machine 30. The detailed configuration of the coordinate measuring machine 30 will be described later.

[0036] The lifting mechanism 32 holds the CMM 30 so that it can move freely in the Z direction (up and down), and can switch the CMM 30 between a measurement position and a retracted position in the Z direction. The measurement position is a state in which the CMM 30 is positioned at a height where it can measure the three-dimensional shape of the surface of the electrode pad P. The retracted position is a state in which the CMM 30 is moved above the measurement position in the Z direction and positioned at a height where the tip (the lower end in FIG. 1) of the CMM 30 does not come into contact with or interfere with the wafer W when performing wafer-level inspection. FIG. 1 shows the CMM 30 in the retracted position. FIG. 4 shows the CMM 30 in the measurement position.

[0037] The lifting mechanism 32 includes various actuators such as an electric motor, and under the control of the control device 100, moves the CMM 30 in the Z direction, thereby switching the CMM 30 between a measurement position and a retracted position. Alternatively, the CMM 30 may be manually moved by a user. This can reduce costs, simplify the configuration, and make the device more compact. The optical unit scanning mechanism 52 (described later) and the lifting mechanism 32 may be integrated into a single mechanism.

[0038] Next, a detailed description will be given of the configuration of the coordinate measuring machine 30. Fig. 5 is a schematic configuration diagram showing the coordinate measuring machine 30. As shown in Fig. 5, the coordinate measuring machine 30 includes an optical unit 50, an optical unit scanning mechanism 52, and a scale 54.

[0039] The optical unit 50 is a part of the coordinate measuring machine 30 that has an optical function, and is composed of a Michelson-type white light interference microscope. As shown in Fig. 5, this optical unit 50 includes a light source unit 40, a beam splitter 42, an interference objective lens 44, an imaging lens 46, and a camera 48. The interference objective lens 44, the beam splitter 42, the imaging lens 46, and the camera 48 are arranged in this order above the surface to be measured (electrode pads P on the wafer W) in the Z direction. The light source unit 40 is also arranged at a position facing the beam splitter 42 in the X direction.

[0040] Under the control of the control device 100, the light source unit 40 emits a parallel beam of white light (low-coherence light with little coherence) as measurement light L1 toward the beam splitter 42. Although not shown, the light source unit 40 includes a light source capable of emitting measurement light L1, such as a light-emitting diode, a semiconductor laser, a halogen lamp, or a high-intensity discharge lamp, and a collector lens that converts the measurement light L1 emitted from the light source into a parallel beam.

[0041] A half mirror, for example, is used as the beam splitter 42. The beam splitter 42 reflects a portion of the measurement light L1 incident from the light source unit 40 toward the interference objective lens 44 located below in the Z direction. The beam splitter 42 also transmits a portion of the combined light L3 (described below) incident from the interference objective lens 44 toward the upper side in the Z direction, and emits this combined light L3 toward the imaging lens 46.

[0042] The interference objective lens 44 is a Michelson type and includes an objective lens 44a, a beam splitter 44b, and a reference surface 44c. The beam splitter 44b and the objective lens 44a are arranged in this order above the surface to be measured in the Z direction. The reference surface 44c is arranged opposite the beam splitter 44b in the X direction. While the following description will be given using a Michelson type interference optical system, the interference optical system is not limited to the Michelson type, and known interference optical systems such as a Mirau type or a Linnick type can also be used.

[0043] The objective lens 44a has a light-condensing effect, and condenses the measurement light L1 incident from the beam splitter 42 onto the surface to be measured through the beam splitter 44b.

[0044] The beam splitter 44b is, for example, a half mirror. The beam splitter 44b splits a portion of the measurement light L1 incident from the objective lens 44a as reference light L2, transmits the remaining measurement light L1, and emits it toward the surface to be measured, while reflecting the reference light L2 toward the reference surface 44c. The measurement light L1 transmitted through the beam splitter 44b is irradiated onto the surface to be measured, and is then reflected by the surface to return to the beam splitter 44b.

[0045] The reference surface 44c is, for example, a reflecting mirror, and reflects the reference light L2 incident from the beam splitter 44b toward the beam splitter 44b. The position of this reference surface 44c in the X direction can be manually adjusted by a position adjustment mechanism (e.g., a ball screw mechanism, an actuator, etc.) not shown. This makes it possible to adjust the optical path length (reference optical path length) of the reference light L2.

[0046] The beam splitter 44b generates a combined light L3 from the measurement light L1 returning from the measured surface and the reference light L2 returning from the reference surface 44c, and emits this combined light L3 toward the objective lens 44a located above in the Z direction. This combined light L3 passes through the objective lens 44a and the beam splitter 42 and enters the imaging lens 46.

[0047] The imaging lens 46 forms an image of the combined light L3 incident from the beam splitter 42 on an imaging plane (not shown) of the camera 48. Specifically, the imaging lens 46 forms an image of a point on the focal plane of the objective lens 44a as an image point on the imaging plane of the camera 48.

[0048] Although not shown, the camera 48 has a CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor) imaging element. The camera 48 captures an image of the combined light L3 formed on the imaging surface of the imaging element by the imaging lens 46, processes the imaging signal of the combined light L3 obtained by this imaging, and outputs the imaging signal.

[0049] The optical unit scanning mechanism 52 is composed of various actuators such as an electric motor, and holds the optical unit 50 so that it can move freely in the Z direction, which is the scanning direction. Under the control of the control device 100, the optical unit scanning mechanism 52 scans the optical unit 50 along the Z direction.

[0050] The scale 54 is a position detection sensor, such as a linear scale, that detects the Z-direction position of the optical unit 50. The scale 54 repeatedly detects the Z-direction position of the optical unit 50 and repeatedly outputs the position detection result to the control device 100.

[0051] [Control device] Next, a description will be given of the configuration of the control device 100. Fig. 6 is a functional block diagram of the control device 100. Note that in Fig. 6, among the functions of the control device 100, functions other than those related to the present invention (functions related to wafer-level inspection) are omitted from the illustration.

[0052] As shown in FIG. 6, the control device 100 is connected to the coordinate measuring machine 30, the stage moving mechanism 18, the lifting mechanism 32, an operation unit 102, and a display unit 104.

[0053] The operation unit 102 includes operation members (for example, a keyboard, a mouse, etc.) for receiving operation inputs to the control device 100 by the user.

[0054] The display unit 104 is a device for displaying the results of program execution by the control device 100, data of calculation results, etc. The display unit 104 includes, for example, an operation UI (User Interface) and a monitor (for example, a liquid crystal display, etc.) for displaying various information. In addition to the display unit 104, a printer, a speaker, etc. may be connected to the control device 100.

[0055] The control device 100 controls the measurement operation by the coordinate measuring machine 30 in response to operation input from the operation unit 102, and has functions such as calculating the three-dimensional shape of the surface to be measured, and performing diagnostic processing to diagnose whether or not there is an abnormality in the inspection device 10.

[0056] The control device 100 is configured by a computing device such as a personal computer, and includes a computing circuit configured by various processors, memories, etc. The various processors include a central processing unit (CPU), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), and a programmable logic device (e.g., simple programmable logic devices (SPLD), complex programmable logic devices (CPLD), and field programmable gate arrays (FPGA)). The various functions of the control device 100 may be realized by a single processor, or by multiple processors of the same or different types.

[0057] The control device 100 includes a storage unit 110. The storage unit 110 stores a control program and various data. The storage unit 110 is configured, for example, by a hard disk drive (HDD: Hard Disk Drive) or a semiconductor storage device (SSD: Solid State Drive). The storage unit 110 may include a temporary storage element configured, for example, by a RAM (Random Access Memory) such as a DRAM (Dynamic Random Access Memory) or an SRAM (Static Random Access Memory), and may function as a work area for the control device 100.

[0058] The storage unit 110 temporarily stores measurement data (image data) obtained by measurement using the coordinate measuring machine 30. The storage unit 110 also stores various data and diagnostic information generated by the diagnostic processing unit 116.

[0059] The control device 100 reads and executes a control program stored in the storage unit 110, thereby functioning as a measurement control unit 112, a shape calculation unit 114, and a diagnosis processing unit .

[0060] The measurement control unit 112 controls the stage moving mechanism 18, the lifting mechanism 32, and each unit of the coordinate measuring machine 30 to measure the three-dimensional shape of the surface of each electrode pad P on the wafer W. Specifically, after the wafer-level inspection is performed, the measurement control unit 112 controls the stage moving mechanism 18 to move the stage 16 carrying the wafer W to a position facing the coordinate measuring machine 30, as shown in FIG. 4. Next, the measurement control unit 112 controls the lifting mechanism 32 to move the coordinate measuring machine 30 from the retracted position (see FIG. 1) to the measurement position (see FIG. 4). This puts the coordinate measuring machine 30 in a state where it can start measurement.

[0061] Next, the measurement control unit 112 controls the stage moving mechanism 18 to perform relative alignment between the stage 16 and the coordinate measuring machine 30, and then scans the optical unit 50 in the scanning direction (Z direction), causing the camera 48 to repeatedly capture images of the measurement surface at regular intervals. Specifically, the measurement control unit 112 starts emitting the measurement light L1 from the light source unit 40 and then causes the optical unit 50 to scan in the Z direction. Furthermore, while the optical unit driving mechanism 52 scans the optical unit 50 in the Z direction, the measurement control unit 112 repeatedly captures the combined light L3 with the camera 48 and outputs the captured image to the control device 100 each time the optical unit 50 moves a regular interval in the Z direction, based on the detection result of the Z direction position of the optical unit 50 by the scale 54.

[0062] Furthermore, in the CMM 30, due to limitations such as the field of view of the objective lens 44 used, there is a limit to the range (measurable area) R in which the surface shape of the measurement surface can be measured, as shown in an example in Fig. 3, and therefore the entire measurement range cannot be measured in one measurement. Therefore, the measurement control unit 112 changes the position of the stage 16 in the X and Y directions using the stage movement mechanism 18, thereby sequentially changing the measurement position (the position where the CMM 30 faces the wafer W) of the CMM 30, and repeatedly performs the above-mentioned measurement operation at each measurement position. This makes it possible to measure the three-dimensional shape of the surface of each electrode pad P over the entire measurement range.

[0063] The shape calculation unit 114 calculates the three-dimensional shape of the measurement surface based on multiple captured images taken by the camera 48. Specifically, the shape calculation unit 114 compares the brightness values ​​of each pixel at the same coordinate in each captured image. Next, the shape calculation unit 114 determines the Z-direction position at which the brightness value of each pixel at the same coordinate in each captured image is maximized, thereby calculating height information indicating the height position (Z position) of each part of the measurement surface corresponding to each pixel. This generates three-dimensional shape data indicating the three-dimensional shape (height distribution) of the measurement surface. The shape calculation unit 114 then connects the three-dimensional shape data obtained at each measurement position to obtain three-dimensional shape data (three-dimensional point cloud data) of the entire measurement area. The shape calculation unit 62 stores the three-dimensional shape data obtained in this manner in the storage unit 110.

[0064] The diagnostic processing unit 116 executes diagnostic processing to diagnose whether or not there is an abnormality in the inspection device 10 based on the three-dimensional shape data of the surface of each electrode pad P. In this diagnostic processing, for example, the relative tilt between the probe card 20 and the stage 16, the straightness of the stage 16, etc. are diagnosed. The diagnostic processing unit 116 is an example of a diagnostic device of the present invention.

[0065] The diagnostic processing unit 116 includes a shape data acquisition unit 120 , a detection processing unit 122 , a needle trace map creation unit 124 , an analysis processing unit 126 , and a diagnostic information output unit 128 .

[0066] The shape data acquisition unit 120 acquires three-dimensional shape data of the surface of each electrode pad P. As described above, the three-dimensional shape data of the surface of each electrode pad P is determined by the shape calculation unit 114 and stored in the storage unit 110. The shape data acquisition unit 120 acquires the three-dimensional shape data of the surface of each electrode pad P by reading it from the storage unit 110. The three-dimensional shape data of the surface of each electrode pad P may also be acquired directly from the shape calculation unit 114. The three-dimensional shape data of the surface of each electrode pad P is composed of three-dimensional point cloud data indicating the position (XYZ position) of the surface of each electrode pad P (including the inner wall surface of the probe needle mark M).

[0067] The detection processing unit 122 detects the position of the probe needle mark M on each electrode pad P based on the three-dimensional shape data of the surface of each electrode pad P acquired by the shape data acquisition unit 120. Specifically, as a detection process based on the three-dimensional shape data of the surface of each electrode pad P, the detection processing unit 122 performs a process of detecting the position of the upper surface (surface) of the electrode pad P (upper surface detection process), and then performs a process of detecting the position of the probe needle mark M on the electrode pad P (needle mark detection process).

[0068] An example of the detection processing executed by the detection processing unit 122 will now be described with reference to Fig. 7 to Fig. 12. Fig. 7 to Fig. 12 are explanatory diagrams for explaining the detection processing executed by the detection processing unit 122.

[0069] First, as shown in FIG. 7, when the acquired three-dimensional shape data 200 includes multiple electrode pads P, the detection processing unit 122 performs a division process to divide the three-dimensional shape data 100 into each electrode pad P. As a result, three-dimensional shape data 202 divided into each region is obtained. The detection processing unit 122 temporarily stores the three-dimensional data 202 after the division process in the storage unit 110. Note that design position information (design information) of each electrode pad P on the wafer W is pre-stored in the storage unit 110, and the detection processing unit 122 divides the three-dimensional shape data 200 into each electrode pad P based on the design information of the electrode pad P acquired from the storage unit 110. Note that the actual positions of the electrode pads P may contain processing errors, so the three-dimensional shape data 202 may be divided so that, in addition to the target electrode pad P, parts of other surrounding electrode pads P are included (so that they overlap), as shown in the lower right part of FIG.

[0070] Fig. 8 is a schematic diagram showing an example of three-dimensional shape data 202 after division processing in a three-dimensional manner. As shown in Fig. 8, the three-dimensional shape data 202 after division processing is composed of three-dimensional point cloud data indicating the surface positions of the target electrode pad P (including the probe needle mark M) and its surrounding area. Note that the three-dimensional shape data 202 shown in Fig. 8 also includes three-dimensional point cloud data of some of the other electrode pads P surrounding the target electrode pad P.

[0071] Next, the detection processing unit 122 performs preprocessing for the top surface detection process. In this preprocessing, the detection processing unit 122 first reads the three-dimensional shape data 202 after the division process from the storage unit 110 and creates a copy of the read three-dimensional shape data 202. Next, the detection processing unit 122 binarizes the Z coordinates of each point cloud constituting the three-dimensional shape data 202 (specifically, Z=255 for Z=Z1 or greater, and Z=0 for Z less than Z=Z1). This results in binarized shape data 204, as shown in IXA of FIG. 9. The binarized shape data 204 is then divided into clusters by calculating the distance between points, and clusters below a predetermined threshold are deleted from the obtained clusters. This results in shape data 206, as shown in IXB of FIG. 9, consisting of a point cloud corresponding to the top surface of the electrode pad P. Next, a morphological filter or the like is applied to fill holes (corresponding to the probe needle marks M). Then, shape data 208, consisting of the XY coordinates of the remaining point cloud, is extracted.

[0072] After the pre-processing for the upper surface detection process has been performed in this manner, the detection processing unit 122 extracts only the point clouds corresponding to the XY coordinates of the shape data 208 extracted in the pre-processing for the upper surface detection process from the copied three-dimensional shape data 202 (see XA in FIG. 10). As a result, shape data 210 is obtained from which the point clouds at Z=Z1 or more have been extracted, as shown in XB in FIG. 10. Next, the detection processing unit 122 applies a filter to the shape data 210 to remove the point clouds of the inner wall surfaces (slope) of the hole (for example, by finding a least-squares plane and removing points that are far away), and obtains shape data 212 indicating the position of the upper surface of the electrode pad P, as shown in XC in FIG. 10. Then, the average value of the point clouds constituting the obtained shape data 212 is calculated to determine the height position of the upper surface of the electrode pad P. The height position (Z position) of the upper surface of the electrode pad P thus obtained is expressed as Z=Z. a Let's say.

[0073] Next, the detection processing unit 122 performs processing to extract point cloud data of a portion corresponding to the probe needle trace M from the three-dimensional shape data 202 after division processing, as preprocessing for the needle trace detection processing.

[0074] Specifically, first, the detection processing unit 122 reads out the three-dimensional shape data 202 from the storage unit 110 and creates a copy of the read out three-dimensional shape data 202. Next, the detection processing unit 122 binarizes the Z coordinate of each point of the three-dimensional shape data 202 (specifically, Z=255 when Z=Z1 or more, and Z=0 when less than Z=Z1), thereby obtaining binarized shape data 220. Next, as shown in XIA of Fig. 11 , the detection processing unit 122 applies a morphological filter or the like to the binarized shape data 220, thereby obtaining shape data 222 from which noise components (portions corresponding to the probe needle mark M) contained in the shape data 220 have been removed, as shown in XIB of Fig. 11 .

[0075] Next, the detection processing unit 122 calculates the difference between the shape data 222 and the shape data 220 to obtain shape data 224 consisting of the XY coordinates of a point cloud indicating the position of the surface (inner wall surface) of the probe needle trace M, as shown in XIC of Figure 11.

[0076] After the pre-processing for the probe mark detection process has been performed in this manner, the detection processing unit 122 extracts a point cloud of a portion corresponding to the probe needle mark M from the copied three-dimensional shape data 202 (see XIIA in FIG. 12) based on the shape data 224 obtained in the pre-processing. This results in needle mark shape data 226 indicating the position of the surface (inner wall surface) of the probe needle mark M formed on the electrode pad P, as shown in XIIB in FIG.

[0077] Next, the detection processing unit 122 extracts the position of the point (the lower end of the probe needle mark M) with the smallest Z coordinate value from the three-dimensional point cloud data constituting the extracted needle mark shape data 226. For example, if the needle mark shape data 226 is composed of four points (x, y, z) = (1, 1, 190), (1, 2, 188), (2, 1, 187), and (2, 2, 191), rearranging them in ascending order focusing on the Z coordinate results in (2, 1, 187), (1, 2, 188), (1, 1, 190), and (2, 2, 191). Therefore, (2, 1, 187) is the position (XYZ position) of the lower end of the probe needle mark M. In addition, the depth of the probe needle mark M can also be calculated from the difference between the height position of the upper surface of the electrode pad P detected in the above-mentioned upper surface detection process and the position of the lower end of the probe needle mark M.

[0078] By repeatedly performing this process on all of the electrode pads P to be detected, the detection processing unit 122 is able to obtain position data (hereinafter referred to as "probe mark position data") including the position (XYZ position) of the lower end of the probe probe mark M formed on each electrode pad P.

[0079] After determining the needle trace position data as described above, the detection processing unit 122 performs coordinate conversion of the needle trace position data from the measurement coordinate system to the stage coordinate system.

[0080] Here, the measurement coordinate system is a three-dimensional coordinate system whose origin is the optical center of the optical unit 50 constituting the coordinate measuring machine 30, and the needle trace position data detected by the detection processing unit 122 is based on the measurement coordinate system. On the other hand, the stage coordinate system is a coordinate system specific to the device that is determined according to the axis along which the stage 16 moves. In order for the analysis processing unit 126, described later, to perform various analyses based on the stage coordinate system, the needle trace position data detected by the detection processing unit 122 must be converted from the measurement coordinate system to the stage coordinate system. Note that the coordinate conversion from the measurement coordinate system to the stage coordinate system can be performed using a known coordinate conversion method, and therefore a description thereof will be omitted. The analysis processing unit 126, described later, performs analysis processing based on the needle trace position data after coordinate conversion to the stage coordinate system.

[0081] The probe trace map creation unit 124 creates a probe trace map MP (see FIG. 13) based on the probe trace position data of each electrode pad P detected by the detection processing unit 122. The probe trace map MP is an example of map information of the present invention.

[0082] FIG. 13 is a diagram showing an example of the probe trace map MP. As shown in FIG. 13, the probe trace map MP is two-dimensional map information that associates each position in the entire in-plane area of ​​the wafer W with probe trace information that indicates the state of the probe trace M corresponding to each position. The probe trace map MP is information used to diagnose whether or not there is an abnormality in the inspection apparatus 10 and is an example of the diagnostic information of the present invention. Note that the probe trace map MP is not limited to the entire in-plane area of ​​the wafer W, but may be two-dimensional map information that associates each position in at least a portion of the area (e.g., an area including multiple chips) with probe trace information that indicates the state of the probe trace M corresponding to each position. Furthermore, in this embodiment, the probe trace information indicated by the probe trace map MP is information indicating the height position of the bottom end of the probe trace M corresponding to each position. However, the information is not limited to this, and may be, for example, information indicating the shape and area of ​​the probe trace M when the probe trace M is cut at a cross section at an arbitrary depth. From this information, the height position of the bottom end of the probe trace M can be estimated.

[0083] The display mode of the probe mark map MP is determined according to the height position (Z position) of the lower end of the probe needle mark M of the electrode pad P corresponding to each position on the surface of the wafer W. In the example shown in Fig. 13, the height positions of the lower ends of the probe needle marks M of the electrode pad P are displayed in multiple stages (9 stages in Fig. 13) and color-coded (although it is displayed in black and white for convenience of drawing, it is actually displayed in multiple colors). The color-coded display may be a display using color shading (gradation) or black and white shading.

[0084] Furthermore, when creating the needle mark map MP, the average value (or median value) of the height position of the lower end of the probe needle mark M of each electrode pad P may be calculated for each chip C, and the display mode (color-coded display in this example) may be determined based on the average value for each chip C. Furthermore, instead of the height position of the lower end of the probe needle mark M for each electrode pad P, the display mode may be determined according to the depth of the probe needle mark M, the height position of the upper surface of the electrode pad P, or the highest point of each position.

[0085] 14 and 15 are enlarged views of a portion of the probe trace map MP. As shown in Fig. 14 and 15, when the probe trace map MP is enlarged, each electrode pad P on each chip C is displayed in a different color in stages according to the height position of the lower end of the probe needle trace M.

[0086] 14, in each chip C, the height position of the lower end of the probe needle mark M on the electrode pad P gradually decreases from the right side to the left side of the chip C. In other words, the tilt tendency within the chip C is common to each chip C. From this, it can be determined that the probe card 20 is tilted.

[0087] 15, in each chip C, the height position of the lower end of the probe needle mark M of only the electrode pad P at a specific position within the chip C is lower than the height positions of the lower ends of the probe needle marks M of the other electrode pads P. In this case, it can be determined that an abnormality has occurred in a specific probe needle 22 among the multiple probe needles 22 of the probe card 20.

[0088] It is preferable that the probe trace map creation unit 124 has a function to cancel the tilt of the entire wafer W (the tilt of the stage 16 relative to the probe card 20, which corresponds to the tilt of the approximate plane described below) when creating the probe trace map MP. This allows the probe trace map MP to be displayed in a state in which the tilt of the entire wafer W is canceled, making it possible to determine whether or not an abnormality has occurred in the probe card 20 or the probe needles 22 in a state in which the influence of the tilt is eliminated.

[0089] In addition, the needle trace map creation unit 124 may have a function to calculate statistical quantities such as the maximum value, minimum value, or standard deviation of the height position of the lower end of the probe needle trace M of each electrode pad P within one chip C and add them as additional information to the needle trace map MP.

[0090] Furthermore, the needle trace map creating unit 124 may create a display screen to which, in addition to the needle trace map MP, analysis information generated by the analysis processing unit 126, which will be described later, is added.

[0091] In this way, the needle mark map MP makes it easy to check the distribution of the height positions of the lower ends of the probe needle marks M at each position on the surface of the wafer W, and from that distribution it is possible to visually and easily determine whether or not an abnormality has occurred in the probe card 20 or the probe needles 22.

[0092] The analysis processing unit 126 generates analysis information based on the needle trace position data detected by the detection processing unit 122. The analysis information is information used to diagnose whether or not there is an abnormality in the inspection device 10, and is an example of the diagnosis information of the present invention.

[0093] The analysis processing unit 126 executes a first analysis process, a second analysis process, a third analysis process, and a fourth analysis process as analysis processes based on the needle trace position data of each electrode pad P. Each analysis process will be described below.

[0094] In the first analysis process, tilt information is generated to be used for diagnosing whether or not there is an abnormality in the relative tilt between the probe card 20 and the stage 16. Here, the relative tilt between the probe card 20 and the stage 16 correlates with the height position of the lower end of the probe needle mark M formed on each electrode pad P on one chip C. For example, when the probe card 20 and the stage 16 are parallel, the height position of the lower end of the probe needle mark M formed on each electrode pad P on one chip C is approximately constant. On the other hand, when the probe card 20 and the stage 16 are relatively tilted and non-parallel, the height position of the lower end of the probe needle mark M formed on each electrode pad P on one chip C tends to gradually increase or decrease depending on the tilt. Therefore, by analyzing the height position of the lower end of the probe needle mark M formed on each electrode pad P on one chip C, it is possible to determine whether or not there is an abnormality in the relative tilt between the probe card 20 and the stage 16.

[0095] As a specific process in the first analysis process, an approximate plane (least-squares plane) is found by the least squares method from a point cloud indicating the height position of the lower end of the probe needle mark M of each electrode pad P on one chip C. If the found approximate plane is defined as ax + bx + cz = d, the components of the normal vector n of the approximate plane in the X, Y, and Z directions are (a, b, c). If the angle that this normal vector n makes with the Z axis is θ, the following equation (1) holds.

number

[0096] For example, when the angle θ can be regarded as approximately 0 degrees (when it is less than a predetermined threshold), it can be determined that the probe card 20 and the stage 16 are approximately parallel to the XY plane. On the other hand, when the angle θ cannot be regarded as approximately 0 degrees (when it is equal to or greater than a predetermined threshold), it can be determined that at least one of the probe card 20 and the stage 16 is not parallel to the XY plane.

[0097] In this way, in the first analysis process, an index value indicating the angle θ between the Z axis and the normal vector n of the approximation plane obtained from the point cloud indicating the height position of the lower end of the probe needle mark M of each electrode pad P in one chip C is calculated, and this index value is generated as tilt information. The tilt information is output by the diagnostic information output unit 128, which will be described later. This allows the user to easily determine from the tilt information whether or not a relative tilt has occurred between the probe card 20 and the stage 16.

[0098] As an example of tilt information, the angle θ that the normal vector n of the approximate plane makes with the Z axis is shown, but the information is not particularly limited as long as it allows the user to understand whether or not a relative tilt has occurred between the probe card 20 and the stage 16, and may be letters, numbers, symbols, figures, combinations thereof, etc.

[0099] In the second analysis process, the approximate plane obtained in the first analysis process is used to calculate an index value (e.g., root mean square, variance, standard deviation, etc.) indicating the variation in the height position of the lower end of the probe needle mark M of each electrode pad P relative to the approximate plane, and this index value is generated as variation information. The variation information is output by the diagnostic information output unit 128, which will be described later. This allows the user to easily determine whether or not an abnormality has occurred in the probe card 20 from the variation information.

[0100] As with the tilt information described above, the variation information is not particularly limited as long as it allows the user to understand whether or not an abnormality has occurred in the probe card 20, and may be letters, numbers, symbols, figures, combinations thereof, etc.

[0101] In the third analysis process, straightness information is generated to be used for diagnosing whether or not an abnormality has occurred in the straightness of the stage 16 along the movement axes (X, Y, and Z axes). In the third analysis process, attention is focused on the electrode pads P at the same position on each of multiple chips C arranged along the movement axes of the stage 16. For example, when the straightness of the stage 16 is within the appropriate range, the positions of the bottom ends of the probe needle marks M formed on the electrode pads P at the same position on each of the chips C will be approximately the same along the movement axis of the stage 16. On the other hand, when the straightness of the stage 16 is not within the appropriate range, the positions of the bottom ends of the probe needle marks M formed on the electrode pads P at the same position on each of the chips C will have gradually increasing error along the movement axis of the stage 16. Therefore, the straightness of the stage 16 can be determined from the positions of the bottom ends of the probe needle marks M formed on the electrode pads P at the same position on each of the chips C.

[0102] Therefore, in the third analysis process, an index value indicating an error in the straightness of the stage 16 is calculated from the position of the lowest end of the probe needle mark M formed on the electrode pad P at the same position on each chip C, and this index value is generated as straightness information. The straightness information is output by the diagnostic information output unit 128, which will be described later. This allows the user to easily determine from the straightness information whether or not an abnormality has occurred in the straightness of the stage 16.

[0103] As with the tilt information described above, the straightness information is not particularly limited as long as it is information that allows the user to understand whether or not there is an abnormality in the straightness of the stage 16, and may be letters, numbers, symbols, figures, combinations thereof, etc.

[0104] In the fourth analysis process, rotational deviation information is generated that is used to diagnose whether or not an abnormality has occurred in the rotational deviation (pitching, yawing, and rolling) on ​​the movement axes (X, Y, and Z axes) of the stage 16. In the fourth analysis process, an analysis process similar to the first analysis process described above is performed on each of the multiple chips C arranged along the movement axes of the stage 16. For example, as the amount of deviation in the rotational deviation of the stage 16 increases, the amount of change in the direction of the normal vector n of the approximation plane calculated for each chip C (i.e., the inclination of the stage 16 relative to the probe card 20) increases. Therefore, the amount of deviation in the rotational deviation of the stage 16 can be determined from the amount of change in the direction of the normal vector n of the approximation plane calculated for each chip C.

[0105] Therefore, in the fourth analysis process, an index value corresponding to the amount of deviation of the rotational deviation (pitching, yawing, and rolling) of the stage 16 is calculated from the position of the probe needle mark M formed on each electrode pad P of each of the multiple chips C, and the index value is generated as rotational deviation information. The rotational deviation information is output by the diagnostic information output unit 128, which will be described later. This allows the user to easily determine from the rotational deviation information whether or not an abnormality has occurred in the rotational deviation of the stage 16.

[0106] As with the tilt information described above, the rotational deviation information is not particularly limited as long as it allows the user to understand whether or not there is an abnormality in the rotational deviation of the stage 16, and may be letters, numbers, symbols, figures, or a combination thereof.

[0107] The analysis processing unit 126 may be configured to perform only some of the first, second, third, and fourth analysis processes, rather than all of them. For example, a desired analysis process may be selectively performed from among a plurality of analysis processes, based on an analysis process selection operation performed by the user via the operation unit 102.

[0108] The diagnostic information output unit 128 outputs the diagnostic information generated in the diagnostic processing unit 116. Specifically, it outputs the needle trace map MP generated by the needle trace map creation unit 124 and the analysis information (tilt information, variation information, straightness information, and deviation amount information) generated by the analysis processing unit 126. For example, the diagnostic information output unit 128 can generate a display screen including the diagnostic information and output the generated display screen by displaying it on the display unit 104. However, this is not a limitation, and the diagnostic information output unit 128 may output the diagnostic information by printing it out or by transmitting it to another device.

[0109] When an index value indicating the analysis information does not satisfy a predetermined reference range (threshold), the diagnostic information output unit 128 may output an alert to that effect to the display unit 104 or the like. Furthermore, the diagnostic information output unit 128 may have a function of sending a notification or instruction to the inspection device 10 to stop the wafer-level inspection when an index value indicating the analysis information does not satisfy a predetermined reference range. This makes it possible to prevent the occurrence of defective chips and improve yield, and also makes it easy to identify the cause of an abnormality early, thereby reducing downtime due to maintenance of the inspection device 10.

[0110] [Diagnostic method] Next, a diagnostic method performed by the diagnostic processing unit 116 will be described with reference to Fig. 16. Fig. 16 is a flowchart showing an example of the diagnostic method performed by the diagnostic processing unit 116.

[0111] In the diagnostic processing unit 116, first, the shape data acquiring unit 120 acquires three-dimensional shape data of the surface of each electrode pad P (step S10). Specifically, the shape data acquiring unit 120 acquires the three-dimensional shape data of the surface of each electrode pad P by reading it from the storage unit 110. This three-dimensional shape data is obtained by the shape calculation unit 114 through calculation processing based on measurement data (captured images) measured by the three-dimensional measuring machine 10. Step S10 is an example of a shape data acquiring step.

[0112] Next, the detection processing unit 122 detects probe mark position data of each electrode pad P based on the three-dimensional shape data of the surface of each electrode pad P acquired by the shape data acquisition unit 120 (step S12). The probe mark position data of each electrode pad P includes the position (XYZ position) of the bottom end of the probe probe mark M formed on each electrode pad P. Step S12 is an example of a detection processing step.

[0113] Next, the probe trace map creation unit 124 generates a probe trace map MP based on the probe trace position data of each electrode pad P detected by the detection processing unit 122. Then, the diagnostic information output unit 128 generates a display screen including the probe trace map MP created by the probe trace map creation unit 124, and displays the display screen on a monitor (step S14). This enables the user to easily understand the cause of an abnormality in the inspection device 10 by visually checking the probe trace map MP. Step S14 is an example of a diagnostic processing step and a diagnostic information output step.

[0114] Next, the analysis processing unit 126 determines whether or not to perform analysis processing in response to a selection operation by the user (step S16). If the selection to perform analysis processing is made (if Yes), the analysis processing unit 126 performs analysis processing (step S18). In this embodiment, a first analysis processing, a second analysis processing, a third analysis processing, and a fourth analysis processing are sequentially performed as analysis processing. Note that the analysis processing to be performed may be determined from these analysis processing in response to a selection operation by the user. Step S18 is an example of a diagnostic processing step.

[0115] After the analysis process is performed, the diagnostic information output unit 128 generates a display screen including the analysis information generated in the analysis process and displays the display screen on the monitor (step S20). At this time, the diagnostic information output unit 128 may generate the needle trace map MP and the analysis information on the same display screen and display the display screen on the monitor. Note that if the execution of the analysis process is not selected in step S16 (if No), the processes of steps S18 and S20 are not performed. Step S20 is an example of a diagnostic information output step.

[0116] This allows the user to understand the cause of the abnormality in the inspection device 10 more easily and in more detail by checking the analysis information generated by the analysis processing unit 126, making it possible to perform maintenance on the inspection device 10 immediately.

[0117] This completes the flowchart of the diagnostic method shown in FIG.

[0118] [effect] Next, the effects of this embodiment will be described.

[0119] According to this embodiment, it is possible to detect needle mark position data of each electrode pad P from the measurement results obtained by the coordinate measuring machine 30 and provide diagnostic information based on the needle mark position data of each electrode pad P. This allows the user to objectively grasp the state of the inspection device 10 and easily identify the cause of an abnormality.

[0120] Furthermore, in this embodiment, a needle mark map MP showing the distribution state of the probe needle marks M on each electrode pad can be provided as an example of diagnostic information. This makes it possible to visualize the state of the inspection device 10, so that the user can easily understand the cause of an abnormality in the inspection device 10 by visually checking the needle mark map MP. It also becomes possible to determine whether each electrode pad P is OK or NG.

[0121] In addition, in this embodiment, as other examples of diagnostic information, tilt information (information indicating the relative tilt between the probe card 20 and the stage 16), variation information (information indicating an abnormality in the probe card 20), straightness information (information indicating the straightness of the stage 16), and rotation deviation information (information indicating the rotation deviation of the stage 16) can be provided. This enables the user to identify the cause of an abnormality in the inspection device 10 at an early stage, and reduces downtime due to maintenance of the inspection device 10.

[0122] According to this embodiment, it is possible to provide diagnostic information based on the needle mark position data of each electrode pad P, and therefore it is possible to inspect the probe needle mark M itself. For example, based on diagnostic information (such as a needle mark map MP) based on the needle mark position data of each electrode pad P, it is possible to diagnose whether there is an abnormality in the probe needle mark M, such as whether the probe needle 22 has penetrated through the underlying material of the electrode pad P based on the depth of the probe needle mark M, or whether the probe needle 22 has correctly contacted the electrode pad P based on the position of the probe needle mark M in the electrode pad P. Therefore, it can be said that the diagnostic processing unit 116 in this embodiment also functions as a needle mark inspection device that performs needle mark inspection on an inspected wafer W.

[0123] Other Embodiments Next, another embodiment will be described.

[0124] In the above-described embodiment, wafer-level inspection using the probe card 20 and measurement of the three-dimensional shape of the surface of each electrode pad P using the coordinate measuring machine 30 are performed within the same device (inspection device 10), but this is not limited to this and these may be performed in separate devices, as in other embodiments 1 and 2 described below.

[0125] Fig. 17 is a schematic diagram showing the configuration of an inspection system according to another embodiment 1. As shown in Fig. 17, an inspection system 300 according to another embodiment 1 includes a plurality of (two in this example) inspection devices 302 that perform wafer-level inspection, a measurement device 304 that measures the three-dimensional shape of the surface of each electrode pad P on a wafer W after wafer-level inspection, and a server device 306. The inspection devices 302, the measurement devices 304, and the server device 306 are connected to each other via a wired or wireless network 308.

[0126] The inspection device 302 includes the components of the inspection device 10 according to this embodiment, except for the coordinate measuring machine 30 and the lifting mechanism 32. The measurement device 304 includes the components of the inspection device 10 according to this embodiment, except for the probe card 20, the interface 24, and the test head 26.

[0127] In the inspection device 302 and the measurement device 304 of Alternative Embodiment 1, the same components as those in the inspection device 10 of this embodiment are denoted by the same reference numerals as those used in this embodiment, and descriptions thereof will be omitted. Also, in the inspection device 302 and the measurement device 304, the stage and the stage moving mechanism are configured separately, but for convenience they correspond to the stage 16 and the stage moving mechanism 18 of the inspection device 10 of this embodiment and are denoted by the same reference numerals. The same applies to Alternative Embodiment 2 described later.

[0128] The server device 306 includes at least one processor and memory, and executes various processes according to programs stored in the memory. The server device 306 has functions to control the operation of each part of the inspection device 302 and the measurement device 304 and to store various data, as well as functions similar to those of the control device 100 according to this embodiment (see FIG. 6).

[0129] According to the inspection system 300 of the first alternative embodiment, the wafer W subjected to wafer-level inspection by each inspection tool 302 is transported to the measuring tool 304 by a transport means (not shown). Then, the three-dimensional shape of the surface of each electrode pad P is measured by the coordinate measuring machine 30 of the measuring tool 304. The measurement results by the measuring tool 304 are sent to the server device 306 together with inspection tool identification information (identification information unique to the inspection tool 302 that performed the wafer-level inspection) and wafer identification information (identification information unique to the wafer W). The server device 306 stores the measurement results by the coordinate measuring machine 30 of the measuring tool 304 in association with the inspection tool identification information and the wafer identification information. Then, a diagnostic processing unit (not shown) of the server device 306 performs diagnostic processing similar to that of the diagnostic processing unit 116 of the control device 100 of the present embodiment, and outputs diagnostic information (probe mark map MP and analysis information) as the diagnostic results.

[0130] Furthermore, similar to the present embodiment described above, the server device 306 may have a function of sending a notification or instruction to the inspection device 302 to stop the wafer-level inspection when the index value indicating the analysis information does not satisfy a predetermined reference range (threshold value).

[0131] Fig. 18 is a schematic diagram showing the configuration of an inspection system according to another embodiment 2. As shown in Fig. 18, an inspection system 400 according to another embodiment 2 includes an inspection device 402 that performs wafer-level inspection, a measurement device 404 that measures the three-dimensional shape of the surface of each electrode pad P on the wafer W after the wafer-level inspection, and a transport device 406. Although not shown, the inspection system 400 also includes a control device that has the same functions as the control device 100 according to this embodiment (see Fig. 6).

[0132] The transport device 406 includes a cassette 408 containing wafers W and transport means 410 such as a transport arm, and transports the wafers W between the inspection device 402, the measuring device 404, and the cassette 408. As a result, the wafers W after undergoing wafer-level inspection in the inspection device 402 are transported to the measuring device 404 by the transport means 410 of the transport device 406. Then, the three-dimensional shape of the surface of each electrode pad P is measured by the three-dimensional measuring machine 30 of the measuring device 404.

[0133] In the other first and second embodiments, similarly to the present embodiment described above, the user can objectively grasp the state of the inspection device 302 and easily identify the cause of the abnormality.

[0134] In the above-described embodiment (including other embodiments 1 and 2), a surface profile measuring device using white light interferometry has been described as the coordinate measuring machine 30, but the present invention is not limited to this, and a surface profile measuring device employing any measurement method can be applied. For example, measurement methods include a focus variation method, SD-OCT (Spectral Domain Optical Coherence Tomography), FD-OCT (Fourier Domain Optical Coherence Tomography), laser confocal method, color confocal method, triangulation method, light section method, pattern projection method, optical comb method, etc.

[0135] Furthermore, in the present embodiment (including other embodiments 1 and 2) described above, the electrode pads P that are the measurement targets of the coordinate measuring machine 30 do not necessarily have to be all the electrode pads P of all the chips C on the wafer W, but only need to include at least the electrode pads P that are necessary for the diagnostic processing in the diagnostic processing unit 116. For example, the electrode pads P of some of the chips C on the wafer W (e.g., every few chips C) may be the measurement targets. Also, some of the electrode pads P of all the electrode pads P of the chips C (e.g., every few electrode pads P) may be the measurement targets. By reducing the electrode pads P that are the measurement targets of the coordinate measuring machine 30, the time required for the diagnostic processing in the diagnostic processing unit 116 can be shortened.

[0136] Although the embodiments of the present invention have been described above, the present invention is not limited to the above examples, and various improvements and modifications may be made without departing from the spirit of the present invention. [Explanation of symbols]

[0137] 1...inspection system, 10...inspection device, 12...housing, 14...inspection space, 16...stage, 18...stage movement mechanism, 20...probe card, 22...probe needle, 24...interface, 26...test head, 30...three-dimensional measuring machine, 32...lifting mechanism, 40...light source unit, 42...beam splitter, 44...interference objective lens, 46...imaging lens, 48...camera, 50...optical unit, 52...optical unit scanning mechanism, 54...scale, 100...control device, 102...operation unit, 104...display unit, 110...storage unit , 112...measurement control unit, 114...shape calculation unit, 116...diagnosis processing unit, 120...shape data acquisition unit, 122...detection processing unit, 124...needle trace map generation unit, 126...analysis processing unit, 300...inspection system, 302...inspection apparatus, 304...measuring apparatus, 306...server apparatus, 308...network, 400...inspection system, 402...inspection apparatus, 404...measuring apparatus, 406...transportation device, 408...cassette, 410...transportation means, W...wafer, C...chip, P...electrode pad, M...probe needle trace, MP...needle trace map

Claims

1. A diagnostic device that diagnoses the state of an inspection device, the inspection device has a probe card having probe needles and a movable stage on which a wafer is placed, and inspects electrical characteristics by bringing the probe needles into contact with electrode pads of each chip formed on the wafer; The diagnostic device comprises: a shape data acquisition unit that acquires three-dimensional shape data of the surface of the electrode pad after the inspection; a detection processing unit that detects needle mark position data indicating the position of a probe needle mark formed on the electrode pad based on the three-dimensional shape data; a diagnostic processing unit that generates diagnostic information for diagnosing whether or not there is an abnormality in the inspection device based on the needle trace position data; a diagnostic information output unit that outputs the diagnostic information; A diagnostic device comprising:

2. the diagnostic information is map information that associates each position in at least a partial area within the surface of the wafer with probe trace information that indicates the state of the probe trace corresponding to each of the positions; The diagnostic device of claim 1 .

3. the diagnostic information includes tilt information indicating a relative tilt between the probe card and the stage; The diagnostic device of claim 1 .

4. the diagnostic processing unit obtains an approximate plane relative to the height position of the lower end of the probe needle mark formed on each of the electrode pads, and detects a relative tilt between the probe card and the stage based on the direction of a normal vector of the approximate plane. The diagnostic device of claim 3 .

5. the diagnostic information includes straightness information indicating the straightness of the stage; The diagnostic device of claim 1 .

6. the diagnostic information includes rotational deviation information indicating a rotational deviation of the stage; The diagnostic device of claim 1 .

7. The diagnostic information output unit has a function of transmitting a notification or instruction to the testing device to stop the testing based on the diagnostic information. The diagnostic device according to any one of claims 1 to 6.

8. A diagnostic method for diagnosing a state of an inspection device, comprising: the inspection device has a probe card having probe needles and a movable stage on which a wafer is placed, and inspects electrical characteristics by bringing the probe needles into contact with electrode pads of each chip formed on the wafer; The diagnostic method comprises: a shape data acquisition step of acquiring three-dimensional shape data of the surface of the electrode pad after the inspection; a detection processing step of detecting needle mark position data indicating the position of a probe needle mark formed on the electrode pad based on the three-dimensional shape data; a diagnostic processing step of generating diagnostic information for diagnosing whether or not there is an abnormality in the inspection device based on the needle trace position data; a diagnostic information output step of outputting the diagnostic information; A diagnostic method comprising:

9. A probe mark inspection apparatus for inspecting probe marks formed on electrode pads of each chip formed on a wafer, comprising: a shape data acquisition unit that acquires three-dimensional shape data of the surface of the electrode pad; a detection processing unit that detects needle mark position data indicating the position of the probe needle mark based on the three-dimensional shape data; a diagnostic processing unit that generates diagnostic information for diagnosing whether or not there is an abnormality in the probe needle trace based on the needle trace position data; a diagnostic information output unit that outputs the diagnostic information; A needle mark inspection device comprising:

Images