WO2022075041A1 - Appearance inspection device and method - Google Patents

Appearance inspection device and method Download PDF

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Publication number
WO2022075041A1
WO2022075041A1 PCT/JP2021/034259 JP2021034259W WO2022075041A1 WO 2022075041 A1 WO2022075041 A1 WO 2022075041A1 JP 2021034259 W JP2021034259 W JP 2021034259W WO 2022075041 A1 WO2022075041 A1 WO 2022075041A1
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WIPO (PCT)
Prior art keywords
inspection
image
variable region
reference image
region
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PCT/JP2021/034259
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French (fr)
Japanese (ja)
Inventor
英一 大▲美▼
Original Assignee
東レエンジニアリング株式会社
Ｔａｓｍｉｔ株式会社
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Priority to CN202180068633.4A priority Critical patent/CN116438447A/en
Publication of WO2022075041A1 publication Critical patent/WO2022075041A1/en

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
    • G01N21/956—Inspecting patterns on the surface of objects

Definitions

  • the present invention relates to an visual inspection apparatus and method for inspecting the inspection target site by comparing an inspection image obtained by imaging the inspection target site with a reference image.
  • the present invention relates to a wafer appearance inspection device and a method for imaging the appearance of a semiconductor device or the like formed on a wafer and determining the quality of the semiconductor device or the like.
  • a semiconductor device is formed by stacking a large number of semiconductor device circuits (that is, repeated appearance patterns of device chips) on one semiconductor wafer in layers, and then individualized into individual chip components, and the chip components are separated into individual chip components. It is packaged and shipped as a single electronic component or incorporated into electrical products.
  • the inspection image obtained by capturing the repeated appearance pattern of the device chip formed on the wafer is compared with the reference image, and the inspection regarding the quality of each chip part is performed. It is done (for example, Patent Document 1).
  • Patent Document 2 there is known a technique for reducing erroneous detection due to misalignment by aligning an inspection target image and a reference image and then detecting a defect (for example, Patent Document 2).
  • the semiconductor device to be inspected contains a plurality of regions having different properties adjacent to each other. For example, when a chip component is to be inspected, a wiring circuit pattern and an external connection terminal (so-called electrode pad, land portion) are formed on the surface of the wafer.
  • the external connection terminal since the external connection terminal only needs to be able to be joined or connected to an external device, lead wire, etc., the position deviation and dimensional error of the outer edge are not required to be as strict as the wiring circuit pattern.
  • the inspection image obtained by imaging the inspection target part includes a region (variable region) where the positional deviation of the outer edge and the dimensional error are allowed, the boundary with the peripheral region (peripheral region) (that is, that is).
  • the position of the outer edge) varies from inspection image to inspection image. Then, when compared with the reference image, the place where the position of the outer edge fluctuates in the inspection image is detected as a defect (so-called pseudo defect), which is a factor of lowering the yield rate of the device chip.
  • Patent Documents 2 and 3 are premised on the fact that the size, range, pattern, etc. of the reference image are constant, and cannot cope with the case where the dimensions of the inspection target portion fluctuate.
  • a visual inspection device and a method capable of obtaining a desired inspection result without detecting a pseudo defect even if the inspection target site includes a variable region where a positional deviation of an outer edge or a dimensional error is allowed.
  • the purpose is to do.
  • one aspect of the present invention is It is a visual inspection device that captures and inspects the appearance of the part to be inspected.
  • the inspection image acquisition unit that acquires the appearance image of the inspection target part as an inspection image
  • the inspection standard image registration unit that registers the standard image that serves as the standard for inspection of the part to be inspected, It is equipped with an inspection unit that compares the inspection image with the reference image and inspects the part to be inspected.
  • the part to be inspected includes a variable region where positional deviation of the outer edge and dimensional error are allowed. Equipped with an edge detector that processes the inspection image and detects the position of the outer edge of the variable region.
  • variable region reference image in which the outer edge of the variable region is set to a wider range than the standard range and is used as a reference for inspection of the variable region is registered.
  • the inspection department The fluctuation region in the inspection image is compared with the region corresponding to the fluctuation region in the fluctuation region reference image based on the position of the outer edge detected by the edge detection unit, and the fluctuation region is inspected.
  • another aspect of the present invention is It is an appearance inspection method that inspects the inspection target part by comparing the inspection image obtained by imaging the appearance of the inspection target part with the reference image.
  • the standard image registration step for pre-registering the standard image and
  • the inspection image acquisition step to acquire the inspection image and It has an inspection step to inspect the inspection target part by comparing the inspection image and the reference image.
  • the part to be inspected includes a variable region where positional deviation of the outer edge and dimensional error are allowed.
  • a reference image a step of registering a variable region reference image that serves as a reference for inspection of the variable region in which the variable region is set to a wider range than the standard range, and It has an edge detection step that processes the inspection image to detect the position of the outer edge of the variable region.
  • the fluctuation region in the inspection image is compared with the region corresponding to the fluctuation region in the fluctuation region reference image based on the position of the outer edge detected in the edge detection step, and the fluctuation region is inspected. It is a thing.
  • the inspection target part includes a variable region where the positional deviation of the outer edge and the dimensional error are allowed, the desired inspection result can be obtained without detecting a pseudo defect.
  • the three axes of the Cartesian coordinate system are expressed as X, Y, and Z
  • the horizontal direction is expressed as the X direction and the Y direction
  • the direction perpendicular to the XY plane that is, the gravity direction
  • the Z direction is expressed as the Z direction.
  • the direction against gravity is expressed as the upper direction
  • the direction in which gravity acts is expressed as the lower direction.
  • the direction of rotation with the Z direction as the central axis is defined as the ⁇ direction.
  • FIG. 1 is an image diagram showing an example of an inspection image in an example of a form embodying the present invention.
  • FIG. 1 shows an example of an inspection image Px in which an inspection target portion Rx is imaged.
  • the inspection target portion Rx includes a variable region Rx1 in which a positional deviation of the outer edge B and a dimensional error are allowed, and a peripheral region Rx2 adjacent to the variable region Rx1.
  • the external connection terminal formed in the plating process is set as the fluctuation region Rx1 in the inspection target portion Rx, and the wiring circuit pattern or the like is set as the inspection target portion.
  • An example which is set as the peripheral area Rx2 in Rx is shown.
  • FIG. 2 is a schematic diagram showing an overall configuration of an example of a form embodying the present invention.
  • FIG. 2 schematically shows each part constituting the wafer visual inspection apparatus 1 according to the present invention.
  • the wafer visual inspection device 1 captures and inspects the appearance of the inspection target portion Rx set on the surface of the wafer W. For example, an inspection image Px is acquired while sequentially imaging a repeated appearance pattern of a device chip C (a type of semiconductor device) formed on a wafer W at a predetermined pitch in the XY direction, and compared with a pre-registered reference image Pf. By doing so, the entire surface of the wafer W is continuously inspected.
  • the wafer visual inspection device 1 includes an inspection image acquisition unit 2, an inspection reference image registration unit 3, an edge detection unit 4, an inspection unit 5, and the like.
  • the wafer visual inspection device 1 includes a wafer holding unit H, an imaging unit S, a relative moving unit M, a computer CP, a controller CN, and the like.
  • the inspection image acquisition unit 2 acquires an external image of the inspection target portion Rx as an inspection image Px.
  • the inspection image acquisition unit 2 is composed of an image pickup unit S and an input unit of a computer CP.
  • FIG. 3 is a conceptual diagram showing a state of capturing an external image in an example of a form embodying the present invention.
  • FIG. 3 shows the appearance of the device chip C formed on the wafer W at a predetermined pitch in the XY direction while the imaging camera S5 of the imaging unit S moves relative to the wafer W in the direction indicated by the arrow Vs. The state of sequential imaging is shown.
  • the illumination unit S1 is made to emit strobe light at a predetermined interval or position, and an appearance image similar to a still image is captured. Image is taken with the camera S5. Then, the appearance image output from the image pickup camera S5 is input as an inspection image Px to the input unit of the computer CP (that is, the inspection image Px is acquired).
  • the inspection standard image registration unit 3 registers the reference image Pf which is the standard for inspection for the inspection target site Rx. Specifically, the inspection reference image registration unit 3 registers the variable region reference image Pf1 and the peripheral region reference image Pf2 as the reference image Pf.
  • the inspection reference image registration unit 3 is composed of a storage unit and an auxiliary storage unit of the computer CP.
  • FIG. 4 is an image diagram showing an example of a reference image in an example of a form embodying the present invention.
  • FIG. 4A shows an example of the variable region reference image Pf1, which is one of the reference images Pf.
  • FIG. 4B shows an example of the peripheral region reference image Pf2, which is one of the reference images Pf.
  • the variable region reference image Pf1 serves as a reference for inspection of the variable region Rx1, and the outer edge B1 of the variable region Rx1 is set in a range wider than the standard range Rs.
  • the range in which the outer edge B1 of the variable region Rx1 is wider than the standard range Rs means that the entire circumference of the outer edge B1 is located outside the standard range Rs, not simply the area is wide.
  • the peripheral region reference image Pf2 serves as a reference for inspection of the peripheral region Rx2, and the outer edge B2 of the variable region Rx1 is set in a range narrower than the standard range Rs.
  • the range in which the outer edge B2 of the variable region Rx1 is narrower than the standard range Rs means that the entire circumference of the outer edge B is located inside the standard range Rs, not simply the area is narrow.
  • the fluctuation region reference image Pf1 and the peripheral region reference image Pf2 are selected by preparing in advance a limit sample in which the fluctuation of the fluctuation region Rx1 outer edge B is allowed, and are registered in the inspection reference image registration unit 3.
  • the edge detection unit 4 processes the inspection image Px to detect the position of the outer edge B (that is, the boundary with the peripheral region Rx2) of the fluctuation region Rx1. Specifically, the edge detection unit 4 performs difference processing, differentiation processing, and the like on each pixel included in the inspection image Px, and outputs the position information of the pixel determined to be the outer edge B of the fluctuation region Rx1. More specifically, the edge detection unit 4 is composed of a computer CP processing unit, an image processing unit, and an execution program.
  • the inspection unit 5 compares the inspection image Px with the reference image Pf and inspects the inspection target portion Rx, and at the fluctuation region Rx1 in the inspection image Px and the boundary position detected by the edge detection unit 4. Based on this, the fluctuation region Rx1 in the fluctuation region reference image Pf1 is compared with the region corresponding to the position, and the fluctuation region Rx1 is inspected.
  • the inspection unit 5 compares the peripheral region Rx2 in the inspection image Px with the peripheral region Rx2 in the peripheral region reference image Pf2 based on the boundary position detected by the edge detection unit 4, and the peripheral region corresponding to the peripheral region.
  • the region Rx2 is inspected.
  • the inspection unit 5 compares each pixel of the fluctuation region Rx1 in the inspection image Px with the brightness value of the pixel in the reference image Pf1 whose position corresponds to the fluctuation region Rx1, and the brightness difference is predetermined. Determine if it is within the range (that is, within the acceptance criteria). More specifically, the inspection unit 5 is composed of a computer CP processing unit, an image processing unit, and an execution program.
  • the wafer holding portion H holds the wafer W. Specifically, the wafer holding portion H supports the wafer W from the lower surface side while maintaining a horizontal state. More specifically, the wafer holding portion H includes a mounting table H1 having a horizontal upper surface.
  • the mounting table H1 is provided with a groove or a hole in a portion in contact with the wafer W, and the groove or the hole is connected to a negative pressure generating means such as a vacuum pump via a switching valve or the like. Then, the wafer holding portion H can hold and release the wafer W by switching these grooves and holes to a negative pressure state or an atmospheric release state.
  • the image pickup unit S captures the appearance of the inspection target portion and outputs image data.
  • the image pickup unit S includes a lens barrel S0, an illumination unit S1, a half mirror S2, a plurality of objective lenses S3a, S3b, a revolver mechanism S4, an image pickup camera S5, and the like.
  • the lens barrel S0 fixes the illumination unit S1, the half mirror S2, the objective lenses S3a, S3b, the revolver mechanism S4, the image pickup camera S5, etc. in a predetermined posture, and guides the illumination light L1 and the observation light L2.
  • the lens barrel S0 is attached to the device frame 1f via a connecting metal fitting or the like (not shown).
  • the illumination unit S1 emits the illumination light L1 required for imaging.
  • the illumination unit S1 may be exemplified by a laser diode, a metal halide lamp, a xenon lamp, LED illumination, or the like. More specifically, the illumination unit S1 switches between light emission / extinguishing and causes strobe light emission at a predetermined place and timing based on signal control from the outside.
  • the half mirror S2 reflects the illumination light L1 emitted from the illumination unit S1 and irradiates the waha W side, and captures the light (also referred to as reflected light or scattered light, that is, observation light) L2 incident from the waha W side. It is to be passed to the camera S5 side.
  • the objective lenses S3a and S3b form an image of the image pickup area on the work W on the image pickup element of the image pickup camera S5 at different predetermined observation magnifications.
  • the revolver mechanism S4 switches which of the objective lenses S3a and S3b is used. Specifically, the revolver mechanism S4 rotates and stands still by a predetermined angle based on manual or external signal control.
  • the image pickup camera S5 captures the image pickup area F on the work W and acquires the inspection image Px and the reference image Pf. These acquired images are output to the outside (computer CP in this embodiment) as video signals and video data.
  • the relative moving unit M relatively moves the wafer holding unit H and the imaging unit S.
  • the relative moving portion M includes an X-axis slider M1, a Y-axis slider M2, and a rotation mechanism M3.
  • the X-axis slider M1 is mounted on the device frame 1f, and the Y-axis slider M2 is moved in the X direction at an arbitrary speed and stopped at an arbitrary position.
  • the X-axis slider is composed of a pair of rails extending in the X direction, a slider unit that moves on the rails, and a slider drive unit that moves and stops the slider unit.
  • the Y-axis slider M2 moves the rotation mechanism M3 in the Y direction at an arbitrary speed based on the control signal output from the control unit CN, and makes it stand still at an arbitrary position.
  • the Y-axis slider is composed of a pair of rails extending in the Y direction, a slider unit that moves on the rails, and a slider drive unit that moves and stops the slider unit.
  • the slider drive unit of the X-axis slider M1 and the Y-axis slider M2 may be composed of a servo motor that rotates and stands still by signal control from the control unit CN, a combination of a pulse motor and a ball screw mechanism, a linear motor mechanism, and the like. can.
  • the rotation mechanism M3 rotates the mounting table H1 in the ⁇ direction at an arbitrary speed and makes it stand still at an arbitrary angle.
  • the rotation mechanism M3 can be exemplified as a rotation / stationary mechanism such as a direct drive motor that is rotated / stationary at an arbitrary angle by signal control from an external device.
  • a mounting table H1 for a wafer holding portion H is mounted on a member on the rotating side of the rotating mechanism M3.
  • the relative moving unit M Since the relative moving unit M has such a configuration, the wafer W is made independent of the imaging unit S in the XY ⁇ direction while holding the wafer W to be inspected, or in combination with each other, a predetermined value is provided. It can be moved relative to each other at a speed or angle, or it can be stationary at any position or angle.
  • the computer CP inputs signals and data from the outside, performs predetermined arithmetic processing and image processing, and outputs the signals and data to the outside.
  • the computer CP executes the following functions. ⁇ Registration and switching of inspection image registration mode and inspection mode (that is, operation mode) ⁇ Registration and switching of imaging magnification in inspection image registration mode ⁇ Acquisition and registration of reference image Pf in inspection image registration mode ⁇ Inspection Registration of inspection recipes (imaging position, imaging order, imaging interval (pitch, interval), movement speed, etc.) in mode, switching of inspection recipes to be used, etc.-Image processing for inspection image Px and reference image Pf-In inspection mode Position detection (edge detection) of the outer edge B of the variable region Rx in the inspection image Px, acquisition of position information of the outer edge B, etc.-Comparison of the inspection image Px and the reference image Pf in the inspection mode (that is, inspection).
  • the computer CP includes an input unit and an output unit, a storage unit (called a register or a memory), a control unit and an arithmetic unit (called a CPU or MPU), an image processing device (called a GPU), and an auxiliary storage. It is composed of a device (HDD, SSD, etc.) and the like (that is, hardware) and an execution program thereof (that is, software).
  • the controller CN inputs / outputs signals and data to / from an external device (devices of the imaging unit S and the relative moving unit M, a computer CP, etc.) and performs predetermined control processing.
  • the controller CN executes the following functions. Is. -Outputs a signal for holding / releasing the waha W to the waha holding unit H.-Controls the revolver mechanism S4 to switch the objective lens (imaging magnification) to be used.-A signal for strobe light emission to the illuminating unit S1. Outputs an image pickup trigger to the image pickup camera S5. Inputs an image (inspection image or reference image) output from the image pickup camera S5.
  • the image pickup trigger can be output to the image pickup unit S while changing the above. Further, the image pickup magnification and the field of view size can be switched according to the inspection type, and the image pickup trigger can be output while changing the image pickup interval, and a desired image can be acquired.
  • the output of the image pickup trigger can be exemplified by the following method.
  • -A method in which the illumination light L1 is emitted for a very short time (so-called strobe emission) every time the illumination light is moved by a predetermined distance while scanning and moving in the X direction.
  • -A method of moving and stationary to a predetermined position and irradiating the illumination light L1 to take an image (so-called step & repeat).
  • controller CN is composed of a part of the computer CP, a dedicated programmable logic controller (that is, hardware), and its execution program (that is, software).
  • the wafer visual inspection device 1 has an inspection image registration mode and an inspection mode, and can be operated by switching between them.
  • FIG. 5 is a flow chart in an example of a form embodying the present invention.
  • a series of flow of imaging and registering an image (that is, a reference image) as an inspection reference of the device chip C arranged on the wafer W by using the wafer visual inspection device 1 is an operation step. It is shown every time. This is called an inspection image registration flow, and a mode of operating in the operation flow as described below is an inspection image registration mode.
  • the wafer W for registering the reference image Pf is placed on the mounting table H1 of the wafer visual inspection device 1 (step s1).
  • the wafer W includes a device chip C as a reference for quality determination.
  • the wafer W is aligned by reading the alignment mark formed on the wafer W (step s2).
  • the relative moving unit M is controlled, and the wafer W is moved to a position where the device chip C set as the reference image Pf can be imaged by the imaging unit S (that is, the imaging position) (step s3).
  • the reference image Pf is imaged by the image pickup unit S, and the reference image Pf is registered in the inspection reference image registration unit 3 (step s4). Specifically, the reference image Pf for inspecting the variable region Rx1 is registered as the variable region reference image Pf1.
  • step s5 it is determined whether or not to capture / register the reference image, and when the reference image is captured / registered, the above steps s3 to s5 are repeated.
  • the reference image Pf for inspecting the peripheral region Rx2 is registered as the peripheral region reference image Pf2.
  • the wafer W is paid out (step s6).
  • step s7 it is determined whether or not to capture / register the reference image in another wafer (step s7), and when performing imaging / registration, the above steps s1 to s7 are repeated. On the other hand, if it is not necessary to capture and register the reference image, the series of flows is terminated.
  • FIG. 5B a series of flows in which an external appearance image Px of the device chip C arranged on the wafer W is imaged by using the wafer visual inspection device 1 and inspected based on the image is performed for each operation step. It is shown. This is called an inspection flow, and the mode of operating in the operation flow as described below is the inspection mode.
  • the wafer W is placed on the mounting table H1 by setting an inspection recipe by new registration or selecting from the inspection recipes registered in advance (step s11).
  • the wafer W is aligned by reading the alignment mark formed on the wafer W (step s12).
  • the relative moving unit M is controlled, the device chip C is imaged by the imaging unit S while moving the wafer W, and the inspection image Px is acquired (step s13).
  • the edge detection unit 4 detects the position of the outer edge B of the fluctuation region Rx1 in the acquired inspection image Px (step s14).
  • the fluctuation region Rx1 in the inspection image Px is compared with the region corresponding to the fluctuation region Rx1 in the pre-registered fluctuation region reference image Pf1 and the inspection is performed (step s15).
  • the inspection unit 5 changes in the fluctuation region reference image Pf1 based on the positions of the fluctuation region Rx1 in the inspection image Px and the outer edge B of the fluctuation region Rx1 detected by the edge detection unit 4 in the inspection image Px.
  • the variable region Rx1 is inspected by comparing the region Rx1 with the region corresponding to the position.
  • the peripheral region Rx2 in the inspection image Px is compared with the peripheral region Rx2 in the pre-registered peripheral region reference image Pf2 and the region corresponding to the position, and the inspection is performed. Specifically, in the inspection unit 5, the peripheral region Rx2 in the inspection image Px and the periphery in the peripheral region reference image Pf2 based on the positions of the outer edge B of the fluctuation region Rx1 detected by the edge detection unit 4 in the inspection image Px. The peripheral region Rx2 is inspected by comparing the region Rx2 with the region corresponding to the position.
  • step s16 another inspection image Px is acquired to determine whether to continue the inspection or the like (step s16), and if the inspection or the like is to be continued, the above steps s13 to s16 are repeated. On the other hand, if it is not necessary to continue the inspection or the like, the wafer W is paid out (step s17).
  • step s18 it is determined whether or not to acquire and inspect the inspection image in another wafer (step s18), and when further inspecting or the like is performed, the above steps s11 to s18 are repeated. On the other hand, if there is no need for further inspection, the series of flows is terminated.
  • the wafer visual inspection device 1 Since the wafer visual inspection device 1 according to the present invention has such a configuration, Even if the inspection target portion Rx includes a variable region Rx1 to which a positional deviation of the outer edge and a dimensional error are allowed, a desired inspection result can be obtained without detecting a pseudo defect.
  • the peripheral region Rx2 in addition to the fluctuation region Rx1 in the inspection image Px, the peripheral region Rx2 is combined with the peripheral region Rx2 in the peripheral region reference image Pf2 based on the position of the outer edge B detected by the edge detection unit 4. An example is shown in which the position is compared with the corresponding area for inspection.
  • the inspection of the peripheral region Rx2 is not indispensable, and the inspection may be performed only in the variable region Rx1.
  • the inspection target portion Rx is a semiconductor device or the like formed on the wafer W, and an external connection terminal formed on the wafer W in the plating step is set as the fluctuation region Rx1 in the inspection target portion Rx.
  • An example is shown.
  • the amount of plating deposited is not constant, so that the line width and position accuracy of the wiring circuit pattern vary depending on the amount of precipitation.
  • the external connection terminals formed in the plating process are not as strict in terms of line width and position accuracy as the wiring circuit pattern inside the device, and positional deviation and dimensional accuracy are allowed. Therefore, if such a site is set as an inspection target, a desired inspection result can be obtained without detecting a pseudo defect.
  • the present invention can be applied not only to the external connection terminal formed in the plating process but also to the inspection of other inspection target parts.
  • the inspection target portion Rx is set on the surface of the wafer W
  • it may be set on an intermediate layer (for example, a bonded surface) of the laminated substrates.
  • the image pickup unit S may be configured to appropriately select a wavelength transmitted through another laminated film or wafer as the illumination light L1 to irradiate the inspection target portion, and acquire the observation light L2 by the image pickup camera S5.
  • the wafer visual inspection device 1 is shown, and an embodiment in which the inspection image Px is imaged (that is, acquired) while changing the imaging position of the wafer W in which the device chip C to be inspected is arranged in the XY direction is exemplified. ..
  • the relative moving unit M, the imaging unit S, and the like are not indispensable configurations, and the inspection image Px transmitted from the host computer or the external device in which the inspection image Px is stored is used as the computer CP.
  • the edge detection unit 4 detects the position of the outer edge of the fluctuation region Rx1 included in the inspection image Px, and the inspection unit 5 detects the position of the outer edge as described above.
  • the same inspection (so-called offline inspection) may be performed.

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Abstract

Provided are an appearance inspection device and method that make it possible to obtain a desired inspection result without detecting a pseudo defect even if a location under inspection includes a variable region where outer edge position deviation or dimension error is permitted.　Specifically, this appearance inspection device for inspecting the appearance of a location under inspection comprises an inspection image acquisition unit for acquiring an inspection image, an inspection reference image registration unit for registering a reference image to serve as a reference for inspection, and an inspection unit for carrying out inspection by comparing the inspection image and reference image. The location under inspection includes a variable region where outer edge position deviation or dimension error is permitted. There is an edge detection unit for detecting the position of the outer edge of the variable region. A variable region reference image serving as a reference for inspecting the variable region is registered as a reference image. The inspection unit inspects the variable region in the inspection image by comparing the variable region and a region in the variable region reference image that has a position corresponding to that of the variable region on the basis of the position of the outer edge detected by the edge detection unit.

Description

外観検査装置および方法Visual inspection equipment and methods
　本発明は、検査対象部位を撮像した検査画像と基準画像とを比較して当該検査対象部位を検査する外観検査装置および方法に関する。例えば、ウエーハに形成された半導体デバイス等の外観を撮像して、当該半導体デバイス等の良否判定を行うウエーハ外観検査装置および方法に関する。 The present invention relates to an visual inspection apparatus and method for inspecting the inspection target site by comparing an inspection image obtained by imaging the inspection target site with a reference image. For example, the present invention relates to a wafer appearance inspection device and a method for imaging the appearance of a semiconductor device or the like formed on a wafer and determining the quality of the semiconductor device or the like.
　半導体デバイスは、１枚の半導体ウエーハ上に多数の半導体デバイス回路（つまり、デバイスチップの繰り返し外観パターン）が層状に重なり合って形成された後、個々のチップ部品に個片化され、当該チップ部品がパッケージングされて、電子部品として単体で出荷されたり電気製品に組み込まれたりする。 A semiconductor device is formed by stacking a large number of semiconductor device circuits (that is, repeated appearance patterns of device chips) on one semiconductor wafer in layers, and then individualized into individual chip components, and the chip components are separated into individual chip components. It is packaged and shipped as a single electronic component or incorporated into electrical products.
　そして、個々のチップ部品が個片化される前に、ウエーハ上に形成されたデバイスチップの繰り返し外観パターンを撮像した検査画像と基準画像とを比較して、各チップ部品の良否等に関する検査が行われる（例えば、特許文献１）。 Then, before the individual chip parts are separated into individual pieces, the inspection image obtained by capturing the repeated appearance pattern of the device chip formed on the wafer is compared with the reference image, and the inspection regarding the quality of each chip part is performed. It is done (for example, Patent Document 1).
　また、検査対象画像と参照画像を位置合わせしてから欠陥検出することで、位置合わせミスによる誤検出を低減する技術が知られている（例えば、特許文献２）。 Further, there is known a technique for reducing erroneous detection due to misalignment by aligning an inspection target image and a reference image and then detecting a defect (for example, Patent Document 2).
　一方、検査画像と基準画像とを減算処理（つまり、比較）して、画像境界部のパターンマッチングのずれにより発生したノイズにマスクをかけて消去する技術が知られている（例えば、特許文献３）。 On the other hand, there is known a technique of subtracting (that is, comparing) an inspection image and a reference image to mask and erase noise generated due to a deviation in pattern matching at an image boundary portion (for example, Patent Document 3). ).
特開２００７－１５５６１０号公報Japanese Unexamined Patent Publication No. 2007-155610 特開２００３－４４２７号公報Japanese Patent Application Laid-Open No. 2003-4427 特開２０００－３３５０６２号公報Japanese Unexamined Patent Publication No. 2000-335062
　検査対象である半導体デバイスには、性質の異なる複数の領域が隣接して含まれている。例えば、チップ部品を検査対象とする場合、配線回路パターンや外部接続用端子（いわゆる、電極パッド、ランド部）が、ウエーハの表面に形成されている。 The semiconductor device to be inspected contains a plurality of regions having different properties adjacent to each other. For example, when a chip component is to be inspected, a wiring circuit pattern and an external connection terminal (so-called electrode pad, land portion) are formed on the surface of the wafer.
　この配線回路パターンは、デバイスチップの性能に深く関わるため、断線やショート、線幅の違い、異物の混入等について厳格な検査が求められる。 Since this wiring circuit pattern is deeply related to the performance of the device chip, strict inspection is required for disconnection, short circuit, difference in line width, contamination of foreign matter, etc.
　一方、外部接続用端子は、外部デバイスやリード線等との接合や導通ができれば良いため、外縁の位置ズレや寸法誤差については、配線回路パターンほど厳格さは求められていない。 On the other hand, since the external connection terminal only needs to be able to be joined or connected to an external device, lead wire, etc., the position deviation and dimensional error of the outer edge are not required to be as strict as the wiring circuit pattern.
　そのため、検査対象部位を撮像した検査画像に、外縁の位置ズレや寸法誤差が許容されている領域（変動領域）が含まれている場合、その周辺の領域（周辺領域）との境界（つまり、外縁）の位置が検査画像毎に変動する。そうすると、基準画像と比較したときに、検査画像において外縁の位置が変動するところを欠陥（いわゆる、疑似欠陥）として検出してしまい、デバイスチップの歩留まり率を下げる要因となっていた。 Therefore, if the inspection image obtained by imaging the inspection target part includes a region (variable region) where the positional deviation of the outer edge and the dimensional error are allowed, the boundary with the peripheral region (peripheral region) (that is, that is). The position of the outer edge) varies from inspection image to inspection image. Then, when compared with the reference image, the place where the position of the outer edge fluctuates in the inspection image is detected as a defect (so-called pseudo defect), which is a factor of lowering the yield rate of the device chip.
　また、特許文献２，３のような従来技術は、基準画像の大きさや範囲、パターン等が一定であることが前提であり、検査対象部位の寸法が変動する場合に対応できなかった。 Further, the conventional techniques such as Patent Documents 2 and 3 are premised on the fact that the size, range, pattern, etc. of the reference image are constant, and cannot cope with the case where the dimensions of the inspection target portion fluctuate.
　そこで本発明は、上記の問題点に鑑みてなされたものであり、
検査対象部位に、外縁の位置ズレや寸法誤差が許容されている変動領域が含まれていても、疑似欠陥を検出することなく、所望の検査結果を得ることができる外観検査装置および方法を提供することを目的とする。 Therefore, the present invention has been made in view of the above problems.
Provided is a visual inspection device and a method capable of obtaining a desired inspection result without detecting a pseudo defect even if the inspection target site includes a variable region where a positional deviation of an outer edge or a dimensional error is allowed. The purpose is to do.
　以上の課題を解決するために、本発明に係る一態様は、
　検査対象部位の外観を撮像して検査する外観検査装置であって、
　検査対象部位の外観画像を検査画像として取得する検査画像取得部と、
　検査対象部位に対する検査の基準となる基準画像を登録する検査基準画像登録部と、
　検査画像と基準画像とを比較して、検査対象部位に対する検査を行う検査部とを備え、
　検査対象部位には、外縁の位置ズレや寸法誤差が許容されている変動領域が含まれており、
　検査画像を処理して変動領域の外縁の位置を検出するエッジ検出部を備え、
　基準画像として、変動領域の外縁が標準範囲より広い範囲に設定された、当該変動領域に対する検査の基準となる変動領域基準画像が登録されており、
　検査部は、
検査画像における変動領域と、エッジ検出部で検出された外縁の位置に基づいて変動領域基準画像における当該変動領域と位置が対応する領域とを比較して、当該変動領域を検査するものである。 In order to solve the above problems, one aspect of the present invention is
It is a visual inspection device that captures and inspects the appearance of the part to be inspected.
The inspection image acquisition unit that acquires the appearance image of the inspection target part as an inspection image,
The inspection standard image registration unit that registers the standard image that serves as the standard for inspection of the part to be inspected,
It is equipped with an inspection unit that compares the inspection image with the reference image and inspects the part to be inspected.
The part to be inspected includes a variable region where positional deviation of the outer edge and dimensional error are allowed.
Equipped with an edge detector that processes the inspection image and detects the position of the outer edge of the variable region.
As a reference image, a variable region reference image in which the outer edge of the variable region is set to a wider range than the standard range and is used as a reference for inspection of the variable region is registered.
The inspection department
The fluctuation region in the inspection image is compared with the region corresponding to the fluctuation region in the fluctuation region reference image based on the position of the outer edge detected by the edge detection unit, and the fluctuation region is inspected.
　また、本発明に係る別の一態様は、
　検査対象部位の外観を撮像した検査画像と基準画像とを比較して当該検査対象部位を検査する外観検査方法であって、
　基準画像を予め登録する基準画像登録ステップと、
　検査画像を取得する検査画像取得ステップと、
　検査画像及び基準画像を比較して検査対象部位を検査する検査ステップとを有し、
　検査対象部位には、外縁の位置ズレや寸法誤差が許容されている変動領域が含まれており、
　基準画像として、変動領域が標準範囲より広い範囲に設定された、当該変動領域に対する検査の基準となる変動領域基準画像を登録するステップと、
　検査画像を処理して変動領域の外縁の位置を検出するエッジ検出ステップを有し、
　検査ステップでは、検査画像における変動領域と、エッジ検出ステップで検出された外縁の位置に基づいて変動領域基準画像における当該変動領域と位置が対応する領域とを比較して、当該変動領域を検査するものである。 Further, another aspect of the present invention is
It is an appearance inspection method that inspects the inspection target part by comparing the inspection image obtained by imaging the appearance of the inspection target part with the reference image.
The standard image registration step for pre-registering the standard image and
The inspection image acquisition step to acquire the inspection image and
It has an inspection step to inspect the inspection target part by comparing the inspection image and the reference image.
The part to be inspected includes a variable region where positional deviation of the outer edge and dimensional error are allowed.
As a reference image, a step of registering a variable region reference image that serves as a reference for inspection of the variable region in which the variable region is set to a wider range than the standard range, and
It has an edge detection step that processes the inspection image to detect the position of the outer edge of the variable region.
In the inspection step, the fluctuation region in the inspection image is compared with the region corresponding to the fluctuation region in the fluctuation region reference image based on the position of the outer edge detected in the edge detection step, and the fluctuation region is inspected. It is a thing.
　検査対象部位に、外縁の位置ズレや寸法誤差が許容されている変動領域が含まれていても、疑似欠陥を検出することなく、所望の検査結果を得ることができる。 Even if the inspection target part includes a variable region where the positional deviation of the outer edge and the dimensional error are allowed, the desired inspection result can be obtained without detecting a pseudo defect.
本発明を具現化する形態の一例における検査画像の一例を示す画像図である。It is an image diagram which shows an example of the inspection image in the example of the form which embodies the present invention. 本発明を具現化する形態の一例の全体構成を示す概略図である。It is a schematic diagram which shows the whole structure of the example of the form which embodies the present invention. 本発明を具現化する形態の一例における外観画像を撮像する様子を示す概念図である。It is a conceptual diagram which shows the state of taking the appearance image in the example of the form which embodies the present invention. 本発明を具現化する形態の一例における基準画像の一例を示す画像図である。It is an image diagram which shows an example of the reference image in the example of the form which embodies the present invention. 本発明を具現化する形態の一例におけるフロー図である。It is a flow figure in an example of the form which embodies the present invention.
　以下に、本発明を実施するための形態について、図を用いながら説明する。なお、以下の説明では、直交座標系の３軸をＸ、Ｙ、Ｚとし、水平方向をＸ方向、Ｙ方向と表現し、ＸＹ平面に垂直な方向（つまり、重力方向）をＺ方向と表現する。また、Ｚ方向は、重力に逆らう方向を上、重力がはたらく方向を下と表現する。また、Ｚ方向を中心軸として回転する方向をθ方向とする。 Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In the following description, the three axes of the Cartesian coordinate system are expressed as X, Y, and Z, the horizontal direction is expressed as the X direction and the Y direction, and the direction perpendicular to the XY plane (that is, the gravity direction) is expressed as the Z direction. do. Further, in the Z direction, the direction against gravity is expressed as the upper direction, and the direction in which gravity acts is expressed as the lower direction. Further, the direction of rotation with the Z direction as the central axis is defined as the θ direction.
　図１は、本発明を具現化する形態の一例における検査画像の一例を示す画像図である。
図１には検査対象部位Ｒｘを撮像した検査画像Ｐｘの一例が示されている。
なお、検査対象部位Ｒｘには、外縁Ｂの位置ズレや寸法誤差が許容されている変動領域Ｒｘ１と、当該変動領域Ｒｘ１に隣接する周辺領域Ｒｘ２が含まれている。 FIG. 1 is an image diagram showing an example of an inspection image in an example of a form embodying the present invention.
FIG. 1 shows an example of an inspection image Px in which an inspection target portion Rx is imaged.
The inspection target portion Rx includes a variable region Rx1 in which a positional deviation of the outer edge B and a dimensional error are allowed, and a peripheral region Rx2 adjacent to the variable region Rx1.
　なお以下の説明では、ウエーハＷに形成されたデバイスチップＣにおいて、メッキ工程で形成された外部接続用端子が検査対象部位Ｒｘにおける変動領域Ｒｘ１として設定されており、配線回路パターン等が検査対象部位Ｒｘにおける周辺領域Ｒｘ２として設定されている例を示す。 In the following description, in the device chip C formed on the wafer W, the external connection terminal formed in the plating process is set as the fluctuation region Rx1 in the inspection target portion Rx, and the wiring circuit pattern or the like is set as the inspection target portion. An example which is set as the peripheral area Rx2 in Rx is shown.
　図２は、本発明を具現化する形態の一例の全体構成を示す概略図である。図２には、本発明に係るウエーハ外観検査装置１を構成する各部が概略的に示されている。 FIG. 2 is a schematic diagram showing an overall configuration of an example of a form embodying the present invention. FIG. 2 schematically shows each part constituting the wafer visual inspection apparatus 1 according to the present invention.
　ウエーハ外観検査装置１は、ウエーハＷの表面に設定された検査対象部位Ｒｘの外観を撮像して検査するものである。例えば、ウエーハＷ上にＸＹ方向に所定ピッチで形成されたデバイスチップＣ（半導体デバイスの一類型）の繰り返し外観パターンを逐次撮像しながら検査画像Ｐｘを取得し、予め登録された基準画像Ｐｆと比較することで、ウエーハＷ全面に対して連続的に検査する構成をしている。具体的には、ウエーハ外観検査装置１は、検査画像取得部２、検査基準画像登録部３、エッジ検出部４、検査部５等を備えている。 The wafer visual inspection device 1 captures and inspects the appearance of the inspection target portion Rx set on the surface of the wafer W. For example, an inspection image Px is acquired while sequentially imaging a repeated appearance pattern of a device chip C (a type of semiconductor device) formed on a wafer W at a predetermined pitch in the XY direction, and compared with a pre-registered reference image Pf. By doing so, the entire surface of the wafer W is continuously inspected. Specifically, the wafer visual inspection device 1 includes an inspection image acquisition unit 2, an inspection reference image registration unit 3, an edge detection unit 4, an inspection unit 5, and the like.
　より具体的には、ウエーハ外観検査装置１は、ウエーハ保持部Ｈ、撮像部Ｓ、相対移動部Ｍ、コンピュータＣＰ、コントローラＣＮ等を備えている。 More specifically, the wafer visual inspection device 1 includes a wafer holding unit H, an imaging unit S, a relative moving unit M, a computer CP, a controller CN, and the like.
　検査画像取得部２は、検査対象部位Ｒｘの外観画像を検査画像Ｐｘとして取得するものである。具体的には、検査画像取得部２は、撮像部ＳとコンピュータＣＰの入力部で構成されている。 The inspection image acquisition unit 2 acquires an external image of the inspection target portion Rx as an inspection image Px. Specifically, the inspection image acquisition unit 2 is composed of an image pickup unit S and an input unit of a computer CP.
　図３は、本発明を具現化する形態の一例における外観画像を撮像する様子を示す概念図である。図３には、撮像部Ｓの撮像カメラＳ５が、ウエーハＷに対して矢印Ｖｓで示す方向に相対移動しながら、ウエーハＷ上にＸＹ方向に所定ピッチで形成されているデバイスチップＣの外観を逐次撮像する様子が示されている。 FIG. 3 is a conceptual diagram showing a state of capturing an external image in an example of a form embodying the present invention. FIG. 3 shows the appearance of the device chip C formed on the wafer W at a predetermined pitch in the XY direction while the imaging camera S5 of the imaging unit S moves relative to the wafer W in the direction indicated by the arrow Vs. The state of sequential imaging is shown.
　具体的には、相対移動部Ｍの相対移動（例えば、矢印Ｖｓ方向へ移動）中に、予め規定された間隔または位置で照明部Ｓ１をストロボ発光させて、静止画と同様の外観画像を撮像カメラＳ５にて撮像する。そして、撮像カメラＳ５から出力された外観画像を検査画像Ｐｘとして、コンピュータＣＰの入力部に入力（つまり、検査画像Ｐｘを取得）する。 Specifically, during the relative movement of the relative moving unit M (for example, moving in the direction of the arrow Vs), the illumination unit S1 is made to emit strobe light at a predetermined interval or position, and an appearance image similar to a still image is captured. Image is taken with the camera S5. Then, the appearance image output from the image pickup camera S5 is input as an inspection image Px to the input unit of the computer CP (that is, the inspection image Px is acquired).
　検査基準画像登録部３は、検査対象部位Ｒｘに対する検査の基準となる基準画像Ｐｆを登録するものである。具体的には、検査基準画像登録部３は、基準画像Ｐｆとして、変動領域基準画像Ｐｆ１や周辺領域基準画像Ｐｆ２が登録されている。 The inspection standard image registration unit 3 registers the reference image Pf which is the standard for inspection for the inspection target site Rx. Specifically, the inspection reference image registration unit 3 registers the variable region reference image Pf1 and the peripheral region reference image Pf2 as the reference image Pf.
　より具体的には、検査基準画像登録部３は、コンピュータＣＰの記憶部や補助記憶部で構成されている。 More specifically, the inspection reference image registration unit 3 is composed of a storage unit and an auxiliary storage unit of the computer CP.
　図４は、本発明を具現化する形態の一例における基準画像の一例を示す画像図である。
図４（ａ）には、基準画像Ｐｆの一つである変動領域基準画像Ｐｆ１の一例が示されている。
図４（ｂ）には、基準画像Ｐｆの一つである周辺領域基準画像Ｐｆ２の一例が示されている。 FIG. 4 is an image diagram showing an example of a reference image in an example of a form embodying the present invention.
FIG. 4A shows an example of the variable region reference image Pf1, which is one of the reference images Pf.
FIG. 4B shows an example of the peripheral region reference image Pf2, which is one of the reference images Pf.
　変動領域基準画像Ｐｆ１は、変動領域Ｒｘ１に対する検査の基準となるもので、変動領域Ｒｘ１の外縁Ｂ１が標準範囲Ｒｓより広い範囲に設定されている。ここで言う、変動領域Ｒｘ１の外縁Ｂ１が標準範囲Ｒｓより広い範囲とは、単に面積が広いのではなく、外縁Ｂ１の全周が標準範囲Ｒｓよりも外側に位置している状態を言う。
一方、周辺領域基準画像Ｐｆ２は、周辺領域Ｒｘ２に対する検査の基準となるもので、変動領域Ｒｘ１の外縁Ｂ２が標準範囲Ｒｓより狭い範囲に設定されている。ここで言う、変動領域Ｒｘ１の外縁Ｂ２が標準範囲Ｒｓより狭い範囲とは、単に面積が狭いのではなく、外縁Ｂの全周が標準範囲Ｒｓよりも内側に位置している状態を言う。 The variable region reference image Pf1 serves as a reference for inspection of the variable region Rx1, and the outer edge B1 of the variable region Rx1 is set in a range wider than the standard range Rs. Here, the range in which the outer edge B1 of the variable region Rx1 is wider than the standard range Rs means that the entire circumference of the outer edge B1 is located outside the standard range Rs, not simply the area is wide.
On the other hand, the peripheral region reference image Pf2 serves as a reference for inspection of the peripheral region Rx2, and the outer edge B2 of the variable region Rx1 is set in a range narrower than the standard range Rs. Here, the range in which the outer edge B2 of the variable region Rx1 is narrower than the standard range Rs means that the entire circumference of the outer edge B is located inside the standard range Rs, not simply the area is narrow.
　なお、変動領域基準画像Ｐｆ１や周辺領域基準画像Ｐｆ２は、変動領域Ｒｘ１外縁Ｂの変動が許容される限度見本を予め準備して選定し、検査基準画像登録部３に登録しておく。 The fluctuation region reference image Pf1 and the peripheral region reference image Pf2 are selected by preparing in advance a limit sample in which the fluctuation of the fluctuation region Rx1 outer edge B is allowed, and are registered in the inspection reference image registration unit 3.
　エッジ検出部４は、検査画像Ｐｘを処理して変動領域Ｒｘ１の外縁Ｂ（つまり、周辺領域Ｒｘ２との境界）の位置を検出するものである。
具体的には、エッジ検出部４は、検査画像Ｐｘに含まれる各画素に対して差分処理や微分処理等を行い、変動領域Ｒｘ１の外縁Ｂと判定された画素の位置情報を出力する。
より具体的には、エッジ検出部４は、コンピュータＣＰの処理部や画像処理部と実行プログラムで構成されている。 The edge detection unit 4 processes the inspection image Px to detect the position of the outer edge B (that is, the boundary with the peripheral region Rx2) of the fluctuation region Rx1.
Specifically, the edge detection unit 4 performs difference processing, differentiation processing, and the like on each pixel included in the inspection image Px, and outputs the position information of the pixel determined to be the outer edge B of the fluctuation region Rx1.
More specifically, the edge detection unit 4 is composed of a computer CP processing unit, an image processing unit, and an execution program.
　検査部５は、検査画像Ｐｘと基準画像Ｐｆとを比較して、検査対象部位Ｒｘに対する検査を行うものであり、検査画像Ｐｘにおける変動領域Ｒｘ１と、エッジ検出部４で検出された境界位置に基づいて変動領域基準画像Ｐｆ１における変動領域Ｒｘ１と位置が対応する領域とを比較して、変動領域Ｒｘ１を検査するものである。 The inspection unit 5 compares the inspection image Px with the reference image Pf and inspects the inspection target portion Rx, and at the fluctuation region Rx1 in the inspection image Px and the boundary position detected by the edge detection unit 4. Based on this, the fluctuation region Rx1 in the fluctuation region reference image Pf1 is compared with the region corresponding to the position, and the fluctuation region Rx1 is inspected.
　さらに検査部５は、検査画像Ｐｘにおける周辺領域Ｒｘ２と、エッジ検出部４で検出された境界位置に基づいて周辺領域基準画像Ｐｆ２における周辺領域Ｒｘ２と位置が対応する領域とを比較して、周辺領域Ｒｘ２を検査するものである。
具体的には、検査部５は、検査画像Ｐｘにおける変動領域Ｒｘ１の各画素について、当該変動領域Ｒｘ１と位置が対応する基準画像Ｐｆ１内の画素の輝度値等とを比較し、輝度差が所定範囲内（つまり、合格基準内）かどうかを判定する。
より具体的には、検査部５は、コンピュータＣＰの処理部や画像処理部と実行プログラムで構成されている。 Further, the inspection unit 5 compares the peripheral region Rx2 in the inspection image Px with the peripheral region Rx2 in the peripheral region reference image Pf2 based on the boundary position detected by the edge detection unit 4, and the peripheral region corresponding to the peripheral region. The region Rx2 is inspected.
Specifically, the inspection unit 5 compares each pixel of the fluctuation region Rx1 in the inspection image Px with the brightness value of the pixel in the reference image Pf1 whose position corresponds to the fluctuation region Rx1, and the brightness difference is predetermined. Determine if it is within the range (that is, within the acceptance criteria).
More specifically, the inspection unit 5 is composed of a computer CP processing unit, an image processing unit, and an execution program.
　ウエーハ保持部Ｈは、ウエーハＷを保持するものである。
具体的には、ウエーハ保持部Ｈは、ウエーハＷを下面側から水平状態を保ちつつ支えるものである。より具体的には、ウエーハ保持部Ｈは、上面が水平な載置台Ｈ１を備えている。
載置台Ｈ１は、ウエーハＷと接触する部分に溝部や孔部が設けられており、これら溝部や孔部は、切替バルブなどを介して真空ポンプなどの負圧発生手段と接続されている。そして、ウエーハ保持部Ｈは、これら溝部や孔部を負圧状態若しくは大気解放状態に切り替えることで、ウエーハＷを保持したり保持解除したりすることができる。 The wafer holding portion H holds the wafer W.
Specifically, the wafer holding portion H supports the wafer W from the lower surface side while maintaining a horizontal state. More specifically, the wafer holding portion H includes a mounting table H1 having a horizontal upper surface.
The mounting table H1 is provided with a groove or a hole in a portion in contact with the wafer W, and the groove or the hole is connected to a negative pressure generating means such as a vacuum pump via a switching valve or the like. Then, the wafer holding portion H can hold and release the wafer W by switching these grooves and holes to a negative pressure state or an atmospheric release state.
　撮像部Ｓは、検査対象部位の外観を撮像し、画像データを出力するものである。具体的には、撮像部Ｓは、鏡筒Ｓ０、照明部Ｓ１、ハーフミラーＳ２、複数の対物レンズＳ３ａ，Ｓ３ｂ、レボルバー機構Ｓ４、撮像カメラＳ５等を備えている。 The image pickup unit S captures the appearance of the inspection target portion and outputs image data. Specifically, the image pickup unit S includes a lens barrel S0, an illumination unit S1, a half mirror S2, a plurality of objective lenses S3a, S3b, a revolver mechanism S4, an image pickup camera S5, and the like.
　鏡筒Ｓ０は、照明部Ｓ１、ハーフミラーＳ２、対物レンズＳ３ａ，Ｓ３ｂ、レボルバー機構Ｓ４、撮像カメラＳ５等を所定の姿勢で固定し、照明光Ｌ１や観察光Ｌ２を導光するものである。鏡筒Ｓ０は、連結金具など（不図示）を介して装置フレーム１ｆに取り付けられている。 The lens barrel S0 fixes the illumination unit S1, the half mirror S2, the objective lenses S3a, S3b, the revolver mechanism S4, the image pickup camera S5, etc. in a predetermined posture, and guides the illumination light L1 and the observation light L2. The lens barrel S0 is attached to the device frame 1f via a connecting metal fitting or the like (not shown).
　照明部Ｓ１は、撮像に必要な照明光Ｌ１を放出するものである。具体的には、照明部Ｓ１は、レーザダイオードやメタルハライドランプ、キセノンランプ、ＬＥＤ照明などが例示できる。より具体的には、照明部Ｓ１は、外部からの信号制御に基づいて、発光／消灯を切り替えたり、所定の場所やタイミングでストロボ発光させたりする。 The illumination unit S1 emits the illumination light L1 required for imaging. Specifically, the illumination unit S1 may be exemplified by a laser diode, a metal halide lamp, a xenon lamp, LED illumination, or the like. More specifically, the illumination unit S1 switches between light emission / extinguishing and causes strobe light emission at a predetermined place and timing based on signal control from the outside.
　ハーフミラーＳ２は、照明部Ｓ１から放出された照明光Ｌ１を反射させてウエーハＷ側に照射し、ウエーハＷ側から入射した光（反射光、散乱光とも言う。つまり、観察光）Ｌ２を撮像カメラＳ５側に通過させるものである。 The half mirror S2 reflects the illumination light L1 emitted from the illumination unit S1 and irradiates the waha W side, and captures the light (also referred to as reflected light or scattered light, that is, observation light) L2 incident from the waha W side. It is to be passed to the camera S5 side.
　対物レンズＳ３ａ，Ｓ３ｂは、ワークＷ上の撮像エリアの像を、それぞれ異なる所定の観察倍率で撮像カメラＳ５の撮像素子に結像させるものである。 The objective lenses S3a and S3b form an image of the image pickup area on the work W on the image pickup element of the image pickup camera S5 at different predetermined observation magnifications.
　レボルバー機構Ｓ４は、対物レンズＳ３ａ，Ｓ３ｂのいずれを使用するか切り替えるものである。具体的には、レボルバー機構Ｓ４は、手動または外部からの信号制御に基づいて、所定の角度ずつ回転および静止するものである。 The revolver mechanism S4 switches which of the objective lenses S3a and S3b is used. Specifically, the revolver mechanism S4 rotates and stands still by a predetermined angle based on manual or external signal control.
　撮像カメラＳ５は、ワークＷ上の撮像エリアＦを撮像し、検査画像Ｐｘや基準画像Ｐｆを取得するものである。取得したこれら画像は、映像信号や映像データとして外部（本実施例では、コンピュータＣＰ）に出力される。 The image pickup camera S5 captures the image pickup area F on the work W and acquires the inspection image Px and the reference image Pf. These acquired images are output to the outside (computer CP in this embodiment) as video signals and video data.
　相対移動部Ｍは、ウエーハ保持部Ｈと撮像部Ｓとを相対移動させるものである。
具体的には、相対移動部Ｍは、Ｘ軸スライダーＭ１と、Ｙ軸スライダーＭ２と、回転機構Ｍ３とを備えて構成されている。 The relative moving unit M relatively moves the wafer holding unit H and the imaging unit S.
Specifically, the relative moving portion M includes an X-axis slider M1, a Y-axis slider M2, and a rotation mechanism M3.
　Ｘ軸スライダーＭ１は、装置フレーム１ｆ上に取り付けられており、Ｙ軸スライダーＭ２をＸ方向に任意の速度で移動させ、任意の位置で静止させるものである。具体的には、Ｘ軸スライダーは、Ｘ方向に延びる１対のレールと、そのレール上を移動するスライダー部と、スライダー部を移動および静止させるスライダー駆動部とで構成されている。 The X-axis slider M1 is mounted on the device frame 1f, and the Y-axis slider M2 is moved in the X direction at an arbitrary speed and stopped at an arbitrary position. Specifically, the X-axis slider is composed of a pair of rails extending in the X direction, a slider unit that moves on the rails, and a slider drive unit that moves and stops the slider unit.
　Ｙ軸スライダーＭ２は、制御部ＣＮから出力される制御信号に基づいて、回転機構Ｍ３をＹ方向に任意の速度で移動させ、任意の位置で静止させるものである。具体的には、Ｙ軸スライダーは、Ｙ方向に延びる１対のレールと、そのレール上を移動するスライダー部と、スライダー部を移動および静止させるスライダー駆動部とで構成されている。 The Y-axis slider M2 moves the rotation mechanism M3 in the Y direction at an arbitrary speed based on the control signal output from the control unit CN, and makes it stand still at an arbitrary position. Specifically, the Y-axis slider is composed of a pair of rails extending in the Y direction, a slider unit that moves on the rails, and a slider drive unit that moves and stops the slider unit.
　Ｘ軸スライダーＭ１とＹ軸スライダーＭ２のスライダー駆動部は、制御部ＣＮからの信号制御により回転し静止するサーボモータやパルスモータとボールネジ機構を組み合わせたものや、リニアモータ機構などで構成することができる。 The slider drive unit of the X-axis slider M1 and the Y-axis slider M2 may be composed of a servo motor that rotates and stands still by signal control from the control unit CN, a combination of a pulse motor and a ball screw mechanism, a linear motor mechanism, and the like. can.
　回転機構Ｍ３は、載置台Ｈ１をθ方向に任意の速度で回転させ、任意の角度で静止させるものである。具体的には、回転機構Ｍ３は、ダイレクトドライブモータなどの、外部機器からの信号制御により任意の角度に回転／静止させるものが例示できる。回転機構Ｍ３の回転する側の部材の上には、ウエーハ保持部Ｈの載置台Ｈ１が取り付けられている。 The rotation mechanism M3 rotates the mounting table H1 in the θ direction at an arbitrary speed and makes it stand still at an arbitrary angle. Specifically, the rotation mechanism M3 can be exemplified as a rotation / stationary mechanism such as a direct drive motor that is rotated / stationary at an arbitrary angle by signal control from an external device. A mounting table H1 for a wafer holding portion H is mounted on a member on the rotating side of the rotating mechanism M3.
　相対移動部Ｍは、この様な構成をしているため、検査対象となるウエーハＷを保持したまま、ウエーハＷを撮像部Ｓに対してＸＹθ方向にそれぞれ独立させて又は複合的に、所定の速度や角度で相対移動させたり、任意の位置・角度で静止させたりすることができる。 Since the relative moving unit M has such a configuration, the wafer W is made independent of the imaging unit S in the XYθ direction while holding the wafer W to be inspected, or in combination with each other, a predetermined value is provided. It can be moved relative to each other at a speed or angle, or it can be stationary at any position or angle.
　コンピュータＣＰは、外部から信号やデータを入力し、所定の演算処理や画像処理を行い、外部に信号やデータを出力するもので、例えば、以下の機能を実行するものである。
・検査画像登録モードおよび検査モード（つまり、運転モード）の登録、切替等
・検査画像登録モードでの撮像倍率の登録、切替等
・検査画像登録モードでの基準画像Ｐｆの取得、登録等
・検査モードでの検査レシピ（撮像位置や撮像順序、撮像間隔（ピッチ、インターバル）、移動速度等）の登録、使用する検査レシピの切替等
・検査画像Ｐｘや基準画像Ｐｆに対する画像処理
・検査モードでの検査画像Ｐｘにおける変動領域Ｒｘの外縁Ｂの位置検出（エッジ検出）や外縁Ｂの位置情報の取得等
・検査モードでの検査画像Ｐｘと基準画像Ｐｆの比較（つまり、検査）
　より具体的には、コンピュータＣＰは、入力部と出力部、記憶部（レジスタやメモリーと呼ばれる）、制御部と演算部（ＣＰＵやＭＰＵと呼ばれる）、画像処理装置（ＧＰＵと呼ばれる）、補助記憶装置（ＨＤＤやＳＳＤなど）等（つまり、ハードウェア）と、その実行プログラム等（つまり、ソフトウェア）で構成されている。 The computer CP inputs signals and data from the outside, performs predetermined arithmetic processing and image processing, and outputs the signals and data to the outside. For example, the computer CP executes the following functions.
・ Registration and switching of inspection image registration mode and inspection mode (that is, operation mode) ・ Registration and switching of imaging magnification in inspection image registration mode ・ Acquisition and registration of reference image Pf in inspection image registration mode ・ Inspection Registration of inspection recipes (imaging position, imaging order, imaging interval (pitch, interval), movement speed, etc.) in mode, switching of inspection recipes to be used, etc.-Image processing for inspection image Px and reference image Pf-In inspection mode Position detection (edge detection) of the outer edge B of the variable region Rx in the inspection image Px, acquisition of position information of the outer edge B, etc.-Comparison of the inspection image Px and the reference image Pf in the inspection mode (that is, inspection).
More specifically, the computer CP includes an input unit and an output unit, a storage unit (called a register or a memory), a control unit and an arithmetic unit (called a CPU or MPU), an image processing device (called a GPU), and an auxiliary storage. It is composed of a device (HDD, SSD, etc.) and the like (that is, hardware) and an execution program thereof (that is, software).
　コントローラＣＮは、外部機器（撮像部Ｓや相対移動部Ｍの各機器、コンピュータＣＰ等）と信号やデータを入出力し、所定の制御処理を行うもので、例えば、以下の機能を実行するものである。
・ウエーハ保持部Ｈに対して、ウエーハＷの保持／解除の信号を出力
・レボルバー機構Ｓ４を制御して、使用する対物レンズ（撮像倍率）を切り替える
・照明部Ｓ１に対して、ストロボ発光の信号を出力
・撮像カメラＳ５に対して、撮像トリガを出力
・撮像カメラＳ５から出力された画像（検査画像や基準画像）を入力
・相対移動部Ｍの駆動制御：Ｘ軸スライダーＭ１、Ｙ軸スライダーＭ２、回転機構Ｍ３の現在位置をモニタリングしつつ、駆動用信号を出力し、制御する機能
　つまり、コントローラＣＮは、相対移動部Ｍを駆動制御すると共に、ウエーハＷ上に設定された撮像エリアＦの場所を変更しながら撮像部Ｓに対して撮像トリガを出力することができる。さらに、検査品種に応じて、撮像倍率や視野サイズを切り替え、撮像する間隔を変えながら撮像トリガを出力することができ、所望の画像を取得することができる。 The controller CN inputs / outputs signals and data to / from an external device (devices of the imaging unit S and the relative moving unit M, a computer CP, etc.) and performs predetermined control processing. For example, the controller CN executes the following functions. Is.
-Outputs a signal for holding / releasing the waha W to the waha holding unit H.-Controls the revolver mechanism S4 to switch the objective lens (imaging magnification) to be used.-A signal for strobe light emission to the illuminating unit S1. Outputs an image pickup trigger to the image pickup camera S5. Inputs an image (inspection image or reference image) output from the image pickup camera S5. Drive control of the relative moving unit M: X-axis slider M1 and Y-axis slider M2. , A function to output and control a drive signal while monitoring the current position of the rotation mechanism M3 That is, the controller CN drives and controls the relative moving unit M and the location of the image pickup area F set on the wayha W. The image pickup trigger can be output to the image pickup unit S while changing the above. Further, the image pickup magnification and the field of view size can be switched according to the inspection type, and the image pickup trigger can be output while changing the image pickup interval, and a desired image can be acquired.
　なお、撮像トリガの出力は、下記の様な方式が例示できる。
・Ｘ方向にスキャン移動させながら、所定距離移動する毎に照明光Ｌ１を極短時間発光（いわゆる、ストロボ発光）させる方式。
・所定位置に移動および静止させて照明光Ｌ１を照射して撮像する（いわゆる、ステップ＆リピート）方式。 The output of the image pickup trigger can be exemplified by the following method.
-A method in which the illumination light L1 is emitted for a very short time (so-called strobe emission) every time the illumination light is moved by a predetermined distance while scanning and moving in the X direction.
-A method of moving and stationary to a predetermined position and irradiating the illumination light L1 to take an image (so-called step & repeat).
　より具体的には、コントローラＣＮは、コンピュータＣＰの一部や専用のプログラマブルロジックコントローラ等（つまり、ハードウェア）と、その実行プログラム等（つまり、ソフトウェア）で構成されている。 More specifically, the controller CN is composed of a part of the computer CP, a dedicated programmable logic controller (that is, hardware), and its execution program (that is, software).
＜運転モードと動作フロー＞
　ウエーハ外観検査装置１は、検査画像登録モードと検査モードを有しており、切り替えて運転することができる。 <Operation mode and operation flow>
The wafer visual inspection device 1 has an inspection image registration mode and an inspection mode, and can be operated by switching between them.
　図５は、本発明を具現化する形態の一例におけるフロー図である。
図５（ａ）には、ウエーハ外観検査装置１を用いてウエーハＷに配置されているデバイスチップＣの検査基準となる画像（つまり、基準画像）を撮像・登録する一連のフローが、動作ステップ毎に示されている。これを検査画像登録フローと呼び、下述の様な動作フローで運転するモードが検査画像登録モードである。 FIG. 5 is a flow chart in an example of a form embodying the present invention.
In FIG. 5A, a series of flow of imaging and registering an image (that is, a reference image) as an inspection reference of the device chip C arranged on the wafer W by using the wafer visual inspection device 1 is an operation step. It is shown every time. This is called an inspection image registration flow, and a mode of operating in the operation flow as described below is an inspection image registration mode.
　先ず、基準画像Ｐｆを登録するためのウエーハＷをウエーハ外観検査装置１の載置台Ｈ１に載置する（ステップｓ１）。このウエーハＷには、良否判定の基準となるデバイスチップＣが含まれている。 First, the wafer W for registering the reference image Pf is placed on the mounting table H1 of the wafer visual inspection device 1 (step s1). The wafer W includes a device chip C as a reference for quality determination.
　続いて、このウエーハＷに形成されたアライメントマークを読み取る等して、ウエーハＷのアライメントを行う（ステップｓ２）。 Subsequently, the wafer W is aligned by reading the alignment mark formed on the wafer W (step s2).
　続いて、相対移動部Ｍを制御し、基準画像Ｐｆとして設定するデバイスチップＣを撮像部Ｓで撮像できる位置（つまり、撮像位置）にウエーハＷを移動させる（ステップｓ３）。 Subsequently, the relative moving unit M is controlled, and the wafer W is moved to a position where the device chip C set as the reference image Pf can be imaged by the imaging unit S (that is, the imaging position) (step s3).
　続いて、撮像部Ｓで基準画像Ｐｆを撮像し、検査基準画像登録部３に基準画像Ｐｆを登録する（ステップｓ４）。具体的には、変動領域Ｒｘ１を検査するための基準画像Ｐｆを変動領域基準画像Ｐｆ１として登録する。 Subsequently, the reference image Pf is imaged by the image pickup unit S, and the reference image Pf is registered in the inspection reference image registration unit 3 (step s4). Specifically, the reference image Pf for inspecting the variable region Rx1 is registered as the variable region reference image Pf1.
　さらに基準画像を撮像・登録するかどうかを判断し（ステップｓ５）、撮像・登録を行う場合は上述のステップｓ３～ｓ５を繰り返す。
具体的には、周辺領域Ｒｘ２を検査するための基準画像Ｐｆを周辺領域基準画像Ｐｆ２として登録する。一方、さらに基準画像を撮像・登録する必要が無ければ、ウエーハＷを払出す（ステップｓ６）。 Further, it is determined whether or not to capture / register the reference image (step s5), and when the reference image is captured / registered, the above steps s3 to s5 are repeated.
Specifically, the reference image Pf for inspecting the peripheral region Rx2 is registered as the peripheral region reference image Pf2. On the other hand, if it is not necessary to further capture and register the reference image, the wafer W is paid out (step s6).
　そして、他のウエーハでも基準画像を撮像・登録するかどうかを判断し（ステップｓ７）、撮像・登録を行う場合は上述のステップｓ１～ｓ７を繰り返す。一方、基準画像を撮像・登録する必要が無ければ、一連のフローを終了する。 Then, it is determined whether or not to capture / register the reference image in another wafer (step s7), and when performing imaging / registration, the above steps s1 to s7 are repeated. On the other hand, if it is not necessary to capture and register the reference image, the series of flows is terminated.
　図５（ｂ）には、ウエーハ外観検査装置１を用いてウエーハＷに配置されているデバイスチップＣの外観画像Ｐｘを撮像し、当該画像に基づいて検査する一連のフローが、動作ステップ毎に示されている。これを検査フローと呼び、下述の様な動作フローで運転するモードが検査モードである。 In FIG. 5B, a series of flows in which an external appearance image Px of the device chip C arranged on the wafer W is imaged by using the wafer visual inspection device 1 and inspected based on the image is performed for each operation step. It is shown. This is called an inspection flow, and the mode of operating in the operation flow as described below is the inspection mode.
　先ず、新規登録にて検査レシピを設定したり、予め登録された検査レシピから選択したりして、ウエーハＷを載置台Ｈ１に載置する（ステップｓ１１）。 First, the wafer W is placed on the mounting table H1 by setting an inspection recipe by new registration or selecting from the inspection recipes registered in advance (step s11).
　続いて、このウエーハＷに形成されたアライメントマークを読み取る等して、ウエーハＷのアライメントを行う（ステップｓ１２）。 Subsequently, the wafer W is aligned by reading the alignment mark formed on the wafer W (step s12).
　続いて、相対移動部Ｍを制御し、ウエーハＷを移動させながら撮像部ＳでデバイスチップＣを撮像し、検査画像Ｐｘを取得する（ステップｓ１３）。 Subsequently, the relative moving unit M is controlled, the device chip C is imaged by the imaging unit S while moving the wafer W, and the inspection image Px is acquired (step s13).
　続いて、取得した検査画像Ｐｘにおける変動領域Ｒｘ１の外縁Ｂの位置をエッジ検出部４にて検出する（ステップｓ１４）。 Subsequently, the edge detection unit 4 detects the position of the outer edge B of the fluctuation region Rx1 in the acquired inspection image Px (step s14).
　続いて、検査画像Ｐｘにおける変動領域Ｒｘ１と、予め登録された変動領域基準画像Ｐｆ１における変動領域Ｒｘ１と位置が対応する領域とをと比較し、検査を行う（ステップｓ１５）。具体的には、検査部５にて、検査画像Ｐｘにおける変動領域Ｒｘ１と、検査画像Ｐｘにおけるエッジ検出部４で検出された変動領域Ｒｘ１の外縁Ｂの位置に基づいて変動領域基準画像Ｐｆ１における変動領域Ｒｘ１と位置が対応する領域と、を比較して変動領域Ｒｘ１を検査する。 Subsequently, the fluctuation region Rx1 in the inspection image Px is compared with the region corresponding to the fluctuation region Rx1 in the pre-registered fluctuation region reference image Pf1 and the inspection is performed (step s15). Specifically, the inspection unit 5 changes in the fluctuation region reference image Pf1 based on the positions of the fluctuation region Rx1 in the inspection image Px and the outer edge B of the fluctuation region Rx1 detected by the edge detection unit 4 in the inspection image Px. The variable region Rx1 is inspected by comparing the region Rx1 with the region corresponding to the position.
　さらに、検査画像Ｐｘにおける周辺領域Ｒｘ２と、予め登録された周辺領域基準画像Ｐｆ２における周辺領域Ｒｘ２と位置が対応する領域とをと比較し、検査を行う。
具体的には、検査部５にて、検査画像Ｐｘにおける周辺領域Ｒｘ２と、検査画像Ｐｘにおけるエッジ検出部４で検出された変動領域Ｒｘ１の外縁Ｂの位置に基づいて周辺領域基準画像Ｐｆ２における周辺領域Ｒｘ２と位置が対応する領域と、を比較して周辺領域Ｒｘ２を検査する。 Further, the peripheral region Rx2 in the inspection image Px is compared with the peripheral region Rx2 in the pre-registered peripheral region reference image Pf2 and the region corresponding to the position, and the inspection is performed.
Specifically, in the inspection unit 5, the peripheral region Rx2 in the inspection image Px and the periphery in the peripheral region reference image Pf2 based on the positions of the outer edge B of the fluctuation region Rx1 detected by the edge detection unit 4 in the inspection image Px. The peripheral region Rx2 is inspected by comparing the region Rx2 with the region corresponding to the position.
　続いて、別の検査画像Ｐｘを取得して検査等を継続するかどうかを判断し（ステップｓ１６）、検査等を継続する場合は上述のステップｓ１３～ｓ１６を繰り返す。
一方、さらに検査等を継続する必要が無ければ、ウエーハＷを払出す（ステップｓ１７）。 Subsequently, another inspection image Px is acquired to determine whether to continue the inspection or the like (step s16), and if the inspection or the like is to be continued, the above steps s13 to s16 are repeated.
On the other hand, if it is not necessary to continue the inspection or the like, the wafer W is paid out (step s17).
　そして、他のウエーハでも検査画像を取得・検査するかどうかを判断し（ステップｓ１８）、さらに検査等を行う場合は上述のステップｓ１１～ｓ１８を繰り返す。一方、さらに検査等する必要が無ければ、一連のフローを終了する。 Then, it is determined whether or not to acquire and inspect the inspection image in another wafer (step s18), and when further inspecting or the like is performed, the above steps s11 to s18 are repeated. On the other hand, if there is no need for further inspection, the series of flows is terminated.
　本発明に係るウエーハ外観検査装置１は、この様な構成をしているため、
検査対象部位Ｒｘに、外縁の位置ズレや寸法誤差が許容されている変動領域Ｒｘ１が含まれていても、疑似欠陥を検出することなく、所望の検査結果を得ることができる。
［他の形態・変形例］
　なお上述では、検査部５にて、検査画像Ｐｘにおける変動領域Ｒｘ１のほか、周辺領域Ｒｘ２を、エッジ検出部４で検出された外縁Ｂの位置に基づいて周辺領域基準画像Ｐｆ２における周辺領域Ｒｘ２と位置が対応する領域とを比較して検査する構成を例示した。
しかし、本発明を具現化する上で、周辺領域Ｒｘ２の検査は必須ではなく、変動領域Ｒｘ１のみ検査を行う構成であっても良い。 Since the wafer visual inspection device 1 according to the present invention has such a configuration,
Even if the inspection target portion Rx includes a variable region Rx1 to which a positional deviation of the outer edge and a dimensional error are allowed, a desired inspection result can be obtained without detecting a pseudo defect.
[Other forms / variants]
In the above description, in the inspection unit 5, in addition to the fluctuation region Rx1 in the inspection image Px, the peripheral region Rx2 is combined with the peripheral region Rx2 in the peripheral region reference image Pf2 based on the position of the outer edge B detected by the edge detection unit 4. An example is shown in which the position is compared with the corresponding area for inspection.
However, in order to realize the present invention, the inspection of the peripheral region Rx2 is not indispensable, and the inspection may be performed only in the variable region Rx1.
　なお上述では、検査対象部位Ｒｘが、ウエーハＷに形成された半導体デバイス等であり、検査対象部位Ｒｘにおける変動領域Ｒｘ１として、ウエーハＷにメッキ工程で形成された外部接続用端子が設定されている例を示した。
メッキ工程では、メッキが析出される量が一定ではないため、その析出量によって、配線回路パターンの線幅や位置精度が変動してしまう。そして、メッキ工程で形成される外部接続用端子は、デバイス内部の配線回路パターンほど線幅や位置精度の規定が厳格でなく、位置ズレや寸法精度が許容されている。
そのため、この様な部位を検査対象に設定すれば、疑似欠陥を検出することなく、所望の検査結果を得ることができる。
しかし、本発明は、メッキ工程で形成された外部接続用端子のみならず、他の検査対象部位の検査に適用することが出来る。　 In the above description, the inspection target portion Rx is a semiconductor device or the like formed on the wafer W, and an external connection terminal formed on the wafer W in the plating step is set as the fluctuation region Rx1 in the inspection target portion Rx. An example is shown.
In the plating process, the amount of plating deposited is not constant, so that the line width and position accuracy of the wiring circuit pattern vary depending on the amount of precipitation. The external connection terminals formed in the plating process are not as strict in terms of line width and position accuracy as the wiring circuit pattern inside the device, and positional deviation and dimensional accuracy are allowed.
Therefore, if such a site is set as an inspection target, a desired inspection result can be obtained without detecting a pseudo defect.
However, the present invention can be applied not only to the external connection terminal formed in the plating process but also to the inspection of other inspection target parts.
　なお上述では、検査対象部位ＲｘがウエーハＷの表面に設定されている構成を例示して説明したが、積層された基板の中間層（例えば、貼合せ面など）に設定されていても良い。この場合、撮像部Ｓは、照明光Ｌ１として他の積層膜やウエーハを透過する波長を適宜選択して検査対象部位に照射し、観察光Ｌ２を撮像カメラＳ５で取得する構成にすれば良い。 Although the configuration in which the inspection target portion Rx is set on the surface of the wafer W has been described above as an example, it may be set on an intermediate layer (for example, a bonded surface) of the laminated substrates. In this case, the image pickup unit S may be configured to appropriately select a wavelength transmitted through another laminated film or wafer as the illumination light L1 to irradiate the inspection target portion, and acquire the observation light L2 by the image pickup camera S5.
　なお上述では、ウエーハ外観検査装置１を示し、検査対象となるデバイスチップＣがＸＹ方向に配置されたウエーハＷの撮像位置を変更しながら検査画像Ｐｘを撮像（つまり、取得）する形態を例示した。
しかし、本発明を具現化する上で、相対移動部Ｍや撮像部Ｓ等は必須の構成では無く、検査画像Ｐｘが記憶されたホストコンピュータや外部機器等から送信された検査画像ＰｘをコンピュータＣＰの入力部で受信（つまり、検査画像取得部２で取得）し、上述と同様にエッジ検出部４で検査画像Ｐｘに含まれる変動領域Ｒｘ１の外縁の位置を検出し、検査部５で上述と同様の検査（いわゆる、オフライン検査）を行う構成としても良い。 In the above description, the wafer visual inspection device 1 is shown, and an embodiment in which the inspection image Px is imaged (that is, acquired) while changing the imaging position of the wafer W in which the device chip C to be inspected is arranged in the XY direction is exemplified. ..
However, in embodying the present invention, the relative moving unit M, the imaging unit S, and the like are not indispensable configurations, and the inspection image Px transmitted from the host computer or the external device in which the inspection image Px is stored is used as the computer CP. (That is, it is acquired by the inspection image acquisition unit 2), the edge detection unit 4 detects the position of the outer edge of the fluctuation region Rx1 included in the inspection image Px, and the inspection unit 5 detects the position of the outer edge as described above. The same inspection (so-called offline inspection) may be performed.
　　１　　ウエーハ外観検査装置
　　２　　検査画像取得部
　　３　　検査基準画像登録部
　　４　　エッジ検出部
　　５　　検査部
　　Ｈ　　ウエーハ保持部
　　Ｓ　　撮像部
　　Ｍ　　相対移動部
　　ＣＰ　コンピュータ
　　ＣＮ　コントローラ
　　ＲＰ　レシピ登録部
　　１ｆ　装置フレーム
　　Ｈ１　載置台
　　Ｓ０　鏡筒
　　Ｓ１　照明部
　　Ｓ２　ハーフミラー
　　Ｓ３ａ，Ｓ３ｂ　対物レンズ
　　Ｓ４　レボルバー機構
　　Ｓ５　撮像カメラ
　　Ｍ１　Ｘ軸スライダー
　　Ｍ２　Ｙ軸スライダー
　　Ｍ３　回転機構
　　Ｗ　　ウエーハ
　　Ｃ　　デバイスチップ（チップ部品）
　　Ｆ　　撮像領域（視野）
　　Ｒｘ　検査対象部位
　　Ｒｘ１　変動領領域（検査対象部位）
　　Ｒｘ２　周辺領領域（検査対象部位）
　　Ｒｓ　標準範囲
　　Ｂ　　外縁（境界）
　　Ｐｘ　検査画像
　　Ｐｆ１　変動領域基準画像
　　Ｐｆ２　周辺領域基準画像
　　Ｌ１　照明光
　　Ｌ２　ウエーハ側から入射した光（反射光、散乱光） 1 Waha appearance inspection device 2 Inspection image acquisition unit 3 Inspection standard image registration unit 4 Edge detection unit 5 Inspection unit H Waha holding unit S Imaging unit M Relative movement unit CP computer CN controller RP Recipe registration unit 1f Device frame H1 Mounting stand S0 Mirror Cylinder S1 Illumination unit S2 Half mirror S3a, S3b Objective lens S4 Revolver mechanism S5 Imaging camera M1 X-axis slider M2 Y-axis slider M3 Rotation mechanism W Weha C device chip (chip parts)
F Imaging area (field of view)
Rx inspection target part Rx1 variable area (inspection target part)
Area around Rx2 (site to be inspected)
Rs standard range B outer edge (boundary)
Px inspection image Pf1 variable region reference image Pf2 peripheral region reference image L1 illumination light L2 light incident from the wafer side (reflected light, scattered light)

Claims (5)

  1. 　検査対象部位の外観を撮像して検査する外観検査装置であって、
    　前記検査対象部位の外観画像を検査画像として取得する検査画像取得部と、
    　前記検査対象部位に対する検査の基準となる基準画像を登録する検査基準画像登録部と、
    　前記検査画像と前記基準画像とを比較して、前記検査対象部位に対する検査を行う検査部とを備え、
    　前記検査対象部位には、外縁の位置ズレや寸法誤差が許容されている変動領域が含まれており、
    　前記検査画像を処理して前記変動領域の前記外縁の位置を検出するエッジ検出部を備え、
    　前記基準画像として、前記変動領域の前記外縁が標準範囲より広い範囲に設定された、当該変動領域に対する検査の基準となる変動領域基準画像が登録されており、
    　前記検査部は、
    前記検査画像における前記変動領域と、前記エッジ検出部で検出された前記外縁の位置に基づいて前記変動領域基準画像における当該変動領域と位置が対応する領域とを比較して、当該変動領域を検査する
    ことを特徴とする外観検査装置。     It is a visual inspection device that captures and inspects the appearance of the part to be inspected.
    An inspection image acquisition unit that acquires an appearance image of the inspection target site as an inspection image,
    An inspection reference image registration unit that registers a reference image that serves as an inspection reference for the inspection target site,
    It is provided with an inspection unit that compares the inspection image with the reference image and inspects the inspection target site.
    The inspection target site includes a variable region where the positional deviation of the outer edge and the dimensional error are allowed.
    It is provided with an edge detection unit that processes the inspection image and detects the position of the outer edge of the fluctuation region.
    As the reference image, a variable region reference image that serves as a reference for inspection of the variable region, in which the outer edge of the variable region is set in a range wider than the standard range, is registered.
    The inspection unit
    The variable region is inspected by comparing the variable region in the inspection image with the region corresponding to the variable region in the variable region reference image based on the position of the outer edge detected by the edge detection unit. A visual inspection device characterized by
  2. 　前記基準画像として、前記変動領域が前記標準範囲より狭い範囲に設定された、前記変動領域の前記外縁より外側の周辺領域に対する検査の基準となる周辺領域基準画像が登録されており、
    　前記検査部は、
    前記検査画像における前記周辺領域と、前記エッジ検出部で検出された前記変動領域の前記外縁の位置に基づいて前記周辺領域基準画像における当該周辺の領域と位置が対応する領域とを比較して、当該周辺領域を検査する
    ことを特徴とする、請求項１に記載の外観検査装置。     As the reference image, a peripheral area reference image that is set to a range narrower than the standard range and serves as a reference for inspection of the peripheral region outside the outer edge of the variable region is registered.
    The inspection unit
    The peripheral region in the inspection image is compared with the region corresponding to the peripheral region in the peripheral region reference image based on the position of the outer edge of the variable region detected by the edge detection unit. The visual inspection apparatus according to claim 1, wherein the peripheral area is inspected.
  3. 　前記検査対象部位は、ウエーハに形成された半導体デバイス等であり、
    前記検査対象部位における前記変動領域として、
    前記ウエーハにメッキ工程で形成された外部接続用端子が設定されている
    ことを特徴とする、請求項１または請求項２に記載の外観検査装置。     The inspection target site is a semiconductor device or the like formed on a wafer.
    As the fluctuation region in the inspection target site,
    The visual inspection apparatus according to claim 1 or 2, wherein an external connection terminal formed in the plating step is set on the wafer.
  4. 　検査対象部位の外観を撮像した検査画像と基準画像とを比較して当該検査対象部位を検査する外観検査方法であって、
    　前記基準画像を予め登録する基準画像登録ステップと、
    　前記検査画像を取得する検査画像取得ステップと、
    　前記検査画像及び前記基準画像を比較して前記検査対象部位を検査する検査ステップとを有し、
    　前記検査対象部位には、外縁の位置ズレや寸法誤差が許容されている変動領域が含まれており、
    　前記基準画像として、前記変動領域が標準範囲より広い範囲に設定された、当該変動領域に対する検査の基準となる変動領域基準画像を登録するステップと、
    　前記検査画像を処理して前記変動領域の前記外縁の位置を検出するエッジ検出ステップを有し、
    　前記検査ステップでは、前記検査画像における前記変動領域と、前記エッジ検出ステップで検出された前記外縁の位置に基づいて前記変動領域基準画像における当該変動領域と位置が対応する領域とを比較して、当該変動領域を検査する
    ことを特徴とする外観検査方法。     It is an appearance inspection method that inspects the inspection target part by comparing the inspection image obtained by imaging the appearance of the inspection target part with the reference image.
    The reference image registration step for pre-registering the reference image and
    The inspection image acquisition step for acquiring the inspection image and
    It has an inspection step of inspecting the inspection target site by comparing the inspection image and the reference image.
    The inspection target site includes a variable region where the positional deviation of the outer edge and the dimensional error are allowed.
    As the reference image, a step of registering a variable region reference image as a reference for inspection of the variable region, in which the variable region is set in a wider range than the standard range, and
    It has an edge detection step of processing the inspection image to detect the position of the outer edge of the variable region.
    In the inspection step, the fluctuation region in the inspection image is compared with the region corresponding to the fluctuation region in the fluctuation region reference image based on the position of the outer edge detected in the edge detection step. A visual inspection method characterized by inspecting the variable region.
  5. 　前記基準画像として、前記変動領域が前記標準範囲より狭い範囲に設定された、前記周辺領域に対する検査の基準となる周辺領域基準画像を登録するステップを有し、
    　前記検査ステップでは、前記検査画像における前記周辺領域と、前記エッジ検出ステップで検出された前記境界位置に基づいて前記他領域基準画像における当該周辺領域と位置が対応する領域とを比較して、当該周辺領域を検査する
    ことを特徴とする、請求項４に記載の外観検査方法。     As the reference image, there is a step of registering a peripheral area reference image as a reference for inspection of the peripheral area in which the variable region is set to a range narrower than the standard range.
    In the inspection step, the peripheral region in the inspection image is compared with the region corresponding to the peripheral region in the other region reference image based on the boundary position detected in the edge detection step. The visual inspection method according to claim 4, wherein the peripheral area is inspected.
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Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005277395A (en) * 2004-02-23 2005-10-06 Nano Geometry Kenkyusho:Kk Pattern inspection apparatus and method
JP2006234667A (en) * 2005-02-25 2006-09-07 Dainippon Screen Mfg Co Ltd Device and method of bump inspection
JP2007155405A (en) * 2005-12-01 2007-06-21 Tdk Corp Visual inspection method and visual inspection device
JP2013246162A (en) * 2012-05-30 2013-12-09 Hitachi High-Technologies Corp Defect inspection method and defect inspection device
US20150036915A1 (en) * 2012-02-16 2015-02-05 Hseb Dresden Gmbh Inspection Method
JP2017161236A (en) * 2016-03-07 2017-09-14 東レエンジニアリング株式会社 Defect inspection device
JP2020008383A (en) * 2018-07-06 2020-01-16 東レエンジニアリング株式会社 Dicing chip inspection device

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005277395A (en) * 2004-02-23 2005-10-06 Nano Geometry Kenkyusho:Kk Pattern inspection apparatus and method
JP2006234667A (en) * 2005-02-25 2006-09-07 Dainippon Screen Mfg Co Ltd Device and method of bump inspection
JP2007155405A (en) * 2005-12-01 2007-06-21 Tdk Corp Visual inspection method and visual inspection device
US20150036915A1 (en) * 2012-02-16 2015-02-05 Hseb Dresden Gmbh Inspection Method
JP2013246162A (en) * 2012-05-30 2013-12-09 Hitachi High-Technologies Corp Defect inspection method and defect inspection device
JP2017161236A (en) * 2016-03-07 2017-09-14 東レエンジニアリング株式会社 Defect inspection device
JP2020008383A (en) * 2018-07-06 2020-01-16 東レエンジニアリング株式会社 Dicing chip inspection device

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