WO2021052463A1 - Système de détection et procédé de détection - Google Patents

Système de détection et procédé de détection Download PDF

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Publication number
WO2021052463A1
WO2021052463A1 PCT/CN2020/116188 CN2020116188W WO2021052463A1 WO 2021052463 A1 WO2021052463 A1 WO 2021052463A1 CN 2020116188 W CN2020116188 W CN 2020116188W WO 2021052463 A1 WO2021052463 A1 WO 2021052463A1
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WIPO (PCT)
Prior art keywords
light
detection
unit
signal
signal light
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PCT/CN2020/116188
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English (en)
Chinese (zh)
Inventor
陈鲁
崔高增
黄有为
王天民
马凯
庞芝亮
Original Assignee
深圳中科飞测科技股份有限公司
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Priority claimed from CN201910892194.3A external-priority patent/CN112540082A/zh
Priority claimed from CN201910892691.3A external-priority patent/CN112540083A/zh
Application filed by 深圳中科飞测科技股份有限公司 filed Critical 深圳中科飞测科技股份有限公司
Publication of WO2021052463A1 publication Critical patent/WO2021052463A1/fr

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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

Definitions

  • the invention relates to the field of high-precision defect detection, in particular to a detection system and a detection method.
  • transparent film-like structures are increasingly applied to the semiconductor field, such as coating on silicon wafers, glass wafers, and glass protective films.
  • Transparent chips are also one of the important directions for the development of the semiconductor industry in the future. Similar to non-transparent materials such as silicon, defects in transparent film materials will also affect its functions. Therefore, inspection of transparent film materials is an important technical means to discover defects in time, improve semiconductor yield, and reduce costs.
  • scattered light detection is the main method for high-precision defect detection in the existing semiconductor industry.
  • this method is usually designed for non-transparent materials.
  • When detecting transparent materials there may be defects on the two opposite surfaces of the transparent material. Therefore, it is difficult to determine the specific location where the scattered signal originates from the transparent material to be measured with traditional methods.
  • the optical imaging method is also a common method for semiconductor defect detection.
  • the optical imaging method can only detect defects of about a few hundred nanometers in size, and it is slow to achieve high-resolution detection, which is difficult to meet. The need for high throughput in industrial applications.
  • the present invention proposes a detection system and a detection method.
  • One aspect of the present invention provides a detection system, which includes:
  • the detection light generating unit is configured to emit second detection light to the object to be measured, wherein the object to be measured includes a first surface and a second surface that are opposed to each other, and the second detection light is transmitted through the first surface. Passing through the object to be measured and scattered by the second surface to form a second signal light;
  • a signal detection unit configured to collect the second signal light in an imaging manner, and generate second detection information according to the second signal light
  • the processing unit is configured to obtain defect information of the second surface based on the second detection information.
  • Another aspect of the present invention also provides a detection method, which includes:
  • the second detection light is emitted to the object to be measured, wherein the object to be measured includes a first surface and a second surface that are opposed to each other, and the second detection light passes through the object to be measured from the first surface and passes through The second surface scatters to form a second signal light;
  • the defect information of the second surface is acquired based on the second detection information.
  • the detection system and detection method disclosed above can perform scanning detection on the object to be tested, and determine the presence, location and size of the defect by receiving scattered light formed by defects (for example, pollutants) on the surface of the object to be tested.
  • defects for example, pollutants
  • the present invention ensures that the signal detection unit can only receive the scattered light formed at the position to be measured on the designated surface, thereby realizing defect detection on multiple surfaces of the transparent film-like structure.
  • Another aspect of the present invention provides a detection system, which includes:
  • the detection light generating unit is configured to emit a first detection light and a second detection light to an object to be measured, wherein the object to be measured includes a first surface and a second surface which are arranged oppositely, and the first detection light passes through the The first surface is scattered to form first signal light, and the second detection light passes through the object to be measured from the first surface and is scattered by the second surface to form second signal light;
  • the first signal detection unit is configured to collect the first signal light and generate first detection information according to the first signal light
  • the second signal detection unit is configured to collect the second signal light and generate second detection information according to the second signal light.
  • Another aspect of the present invention provides a detection method based on a detection system, which includes:
  • the first detection light and the second detection light are emitted to the test object through the detection light generating unit, wherein the test object includes a first surface and a second surface that are arranged oppositely, and the first detection light passes through the The first surface is scattered to form a first signal light, and the second detection light passes through the object to be measured from the first surface and is scattered by the second surface to form a second signal light;
  • the second signal light is collected by the second signal detection unit, and second detection information is generated according to the second signal light.
  • the detection system and detection method disclosed above can perform scanning detection on the object to be tested, and determine the presence, location, and size of the defect by receiving scattered light formed by defects (for example, pollutants) on the surface of the object to be tested.
  • defects for example, pollutants
  • the present invention ensures that the first signal detection unit and the second signal detection unit can only receive the scattered light formed at the position to be measured on the corresponding designated surface, thereby Realize simultaneous defect detection on multiple surfaces of the transparent film-like structure.
  • Figure 1 shows a schematic diagram of the structure of the detection system according to the present invention
  • Figure 2 shows a schematic diagram of the prior art related to the detection system disclosed in the present invention
  • 3A-3B show a first exemplary structural schematic diagram of the detection system according to the present invention
  • FIGS. 4A-4B show a second exemplary structural schematic diagram of the detection system according to the present invention.
  • 4C shows a schematic structural diagram of an exemplary optical displacement unit of the detection system according to the present invention.
  • Figure 5 shows a flow chart of the detection method according to the present invention
  • FIG. 6 is a schematic diagram of a third exemplary structure of the detection system according to the present invention.
  • Fig. 7 is a schematic diagram of a third exemplary detection system disclosed according to the present invention in practical applications.
  • Fig. 8A is a fourth exemplary structural diagram of the detection system according to the present invention.
  • FIG. 8B is a schematic structural diagram of the optical displacement unit of the detection system according to the present invention.
  • Fig. 9 is a flowchart of a detection method based on a detection system according to the present invention.
  • each block in the flowchart or block diagram may represent a module, program segment, or part of code, and the module, program segment, or part of code may include one or more for implementing various embodiments.
  • Executable instructions for the specified logic function may also occur in a different order from the order marked in the drawings. For example, two blocks shown in succession may actually be executed substantially in parallel, or they may sometimes be executed in the reverse order, depending on the functions involved.
  • each block in the flowchart and/or block diagram, as well as the combination of the blocks in the flowchart and/or block diagram, can be implemented by a dedicated hardware-based device that performs the specified function or operation Or it can be implemented using a combination of dedicated hardware and computer instructions.
  • the embodiments of the present disclosure mainly focus on the following technical problems: the imaging detection methods used in the prior art generally require the use of area array detectors for photoelectric detection, and the sampling rate of the area array detectors is low, which limits the increase in detection speed; In addition, the detection accuracy of the imaging detection method is also limited by the optical diffraction limit, so that the method can only clearly image objects with a feature size greater than half of the detection wavelength. For commonly used visible light band light sources, the accuracy is only on the order of a few hundred nanometers. In addition, the scattered light collection method is also used in the prior art to detect defects in the semiconductor.
  • the existing scattered light collection method cannot distinguish that the scattered signal comes from the specific location of the transparent film-like structure, that is, the existing scattered light collection method cannot obtain accurate detection results.
  • the detection system disclosed in the present disclosure at least includes: a detection light generating unit, a signal detection unit, and a processing unit.
  • the photodetector included in the signal detection unit may adopt a line detection with a higher sampling rate. Compared with the existing imaging detection method, it greatly improves the detection speed.
  • the present invention judges the existence and size of defects based on the light intensity of the received signal light, and can detect defects in the order of tens of nanometers through noise control, which significantly improves the detection accuracy.
  • selective reception of scattered light formed by two opposite surface defects of the transparent film-like structure is realized.
  • the detection system disclosed herein includes: a carrier 100, a detection light generating unit (not shown in the drawings), a signal detection unit 200, and a processing unit (with drawings) Not shown in).
  • the carrier 100 is configured to carry the test object 300;
  • the detection light generating unit is configured to emit the first detection light and the second detection light to the test object 300 (the first detection light and the second detection light are also shown in FIG. 1 In the incident light),
  • the test object 300 includes a first surface 310 and a second surface 320 opposed to each other. The first detection light is scattered by the first surface 310 to form the first signal light, and the second detection light is from the first surface.
  • the signal detection unit 200 is configured to collect the first signal light or the second signal light in an imaging manner, and according to the first signal light Generate first inspection information or generate second inspection information according to the second signal light;
  • the processing unit is configured to acquire defect information of the first surface 310 based on the first inspection information, and acquire defects of the second surface 320 based on the second inspection information information.
  • the detection system further includes a control unit configured to control the relative movement between the carrier 100 and the signal detection unit 200.
  • the incident direction of the detection light and the normal direction of the object 300 are at a first angle ⁇
  • the normal direction of the signal detection unit 200 is between the normal direction of the object 300 and the normal direction of the object 300.
  • the second angle ⁇ In the present invention, the absolute value of the second angle ⁇ is different from the absolute value of the first angle ⁇ , that is, the signal detection unit 200 only receives the scattered light formed by the position to be measured of the object 300, It does not receive the reflected light formed by the position to be measured of the object 300 to be measured.
  • the signal detection unit 200 includes: a signal light collector 210 and a photodetector 220.
  • the signal light collector 210 is configured to collect the first signal light and the second signal light respectively;
  • the photodetector 220 is configured to receive the first signal light or the second signal light transmitted by the signal light collector 210, And generate corresponding detection information.
  • the detection system may include a plurality of signal detection units 200, and the plurality of signal detection units are used to detect the first signal light and the second signal light with different azimuth angles.
  • the normal direction of the signal light collector 210 and the normal direction of the test object 300 form the second angle ⁇ .
  • the detection light generating unit may be a point light spot generator or a line light spot generator, and in the case where the detection light generating unit is a point light spot generator, the photodetector 220 is an optical power meter, so as to adopt a point scanning
  • the photodetector 220 is a line detector, so that the surface of the object to be tested is detected by a line scanning detection method.
  • the working principle of the system disclosed in this embodiment is specifically as follows: the first detection light and the second detection light (for example, the incident light in FIG. 1) are incident on two opposite sides of the object 300 respectively.
  • the first detection light and the second detection light for example, the incident light in FIG. 1
  • the position to be measured on the surface when there is no defect in the irradiated position to be measured, all the inspection light will be transmitted from the object to be measured 300, and the transmitted light will be transmitted to the carrier 100 at the bottom and then reflected to the to-be-measured at the same angle.
  • the measured object 300 for example, the reflected light in FIG. 1
  • the signal light collector 210 can only detect very weak noise.
  • the defect When there is a defect in the illuminated position to be measured, the defect causes the detection light to scatter, and the scattered light is transmitted toward all directions of the measured object 300, within a certain angular range of the measured object 300 avoiding the reflected light (for example, The second angle ⁇ ) is provided with a signal detection unit 200, which collects scattered light in a specific spatial angle, and detects and processes the scattered light.
  • the photodetector 220 can only receive the scattered light formed by the first surface 310 (for example, the scattered light shown by the solid line in FIG. 2) or can only receive the scattered light formed by the second surface 310.
  • the scattered light formed by the surface 320 for example, the scattered light shown by the dotted line in FIG. 2).
  • the system disclosed in this embodiment may further adopt a carrying table 100 and a control unit capable of moving the object to be tested.
  • a carrying table 100 and a control unit capable of moving the object to be tested The following will be combined with FIGS. 3A-3B And FIG. 5 describes the specific steps of the system disclosed in this embodiment for detecting the surface of the transparent film-like structure.
  • Step 510 The detection light generating unit emits the first detection light and the second detection light to the test object 300, wherein the first detection light forms the first signal light through the first surface 310, and the second detection light transmits through the first surface 310
  • the second signal light is formed by passing through the object 300 and being scattered by the second surface 320.
  • Step 520 The signal detection unit 200 collects the first signal light in an imaging manner, and forms first detection information according to the first signal light.
  • the specific operations of this step are as follows:
  • the carrying table 100 is configured to move the object 300 to a first relative position, wherein, at the first relative position, the photosensitive surface position 221 of the photodetector 220 and the second relative position
  • the first to-be-measured positions 311 of a surface 310 are conjugate with each other.
  • control unit controls the movement of the carrying platform 100 relative to the signal detection unit 200 so that the object under test 300 and the signal detection unit 200 have a first relative position.
  • the first surface 310 is the object plane
  • the photodetector 220 is in the corresponding image plane.
  • the photodetector 220 can receive the first signal light transmitted by the signal light collector 210, and form first detection information according to the first signal light.
  • Step 530 The signal detection unit 200 collects the second signal light in an imaging manner, and forms second detection information according to the second signal light.
  • the specific operations of this step are as follows:
  • the carrying table 100 is further configured to move the object 300 to a second relative position, wherein, at the second relative position, the photosensitive surface position 221 of the photodetector 220 and The second to-be-measured positions 321 of the second surface 320 are conjugate with each other.
  • control unit controls the movement of the carrying platform 100 relative to the signal detection unit 200 so that the object under test 300 and the signal detection unit 200 have a second relative position.
  • the second surface 320 is the object plane
  • the photodetector 220 is in the corresponding image plane
  • the photodetector 220 is further configured to receive the signal light collector 210
  • the second signal light is transmitted, and second detection information is generated according to the second signal light.
  • the first detection information corresponding to the first signal light and the second detection information corresponding to the second signal light are respectively associated with the received light intensity of the first signal light and the second signal light.
  • Step 540 Obtain defect information of the first surface 310 based on the first detection information, and obtain defect information of the second surface 320 based on the second detection information.
  • the surface defect information of the test object 300 includes one or more of the following information: whether there is a surface defect in the test object 300, the location of the surface defect if there is a surface defect, and the surface defect the size of.
  • the position of the signal detection unit 200 relative to the detection light generating unit (not shown in the figure) is fixed, that is, the signal detection unit 200 in this embodiment can only collect signals from a fixed height and a fixed position. Of scattered light.
  • the position of the test object 300 is changed via the carrier table 100, so that the first surface 310 and the second surface 320 of the test object 300 are located on the signal detection unit 200 to collect scattered light in the two detections. In this way, the interference of the other surface of the object 300 to the surface being tested is eliminated.
  • the position of the signal detection unit is adjustable, and the position of the signal detection unit can be adjusted so that the signal detection unit and the object to be measured have a first relative position or a second relative position.
  • the detection system disclosed in this embodiment is similar to the detection system disclosed in Embodiment 1. Therefore, similar or identical components in the system disclosed in this embodiment will not be repeated here. .
  • the detection system disclosed in this embodiment further includes an optical displacement unit 400 configured to enable the signal detection unit 200 to collect the first signal light and the second signal light when the optical displacement unit 400 enters and exits the optical path. Or, the amount of change in the imaging position of the position to be measured on the first surface 310 and/or the second surface 320 can be adjusted. As shown in FIG. 2, if there are defects at the corresponding positions of the first surface 310 and the second surface 320 of the test object 300, the scattered light generated by the two defects will be collected by the signal light collector 210.
  • the photodetector 220 can only receive the scattered light formed by the first surface 310 (for example, the scattered light shown by the solid line in FIG. 2) or can only receive the scattered light formed by the second surface 310.
  • the scattered light formed by the surface 320 for example, the scattered light shown by the dotted line in FIG. 2).
  • the system disclosed in this embodiment can use the optical displacement unit 400 to detect the two opposite surfaces of the object to be measured 300 respectively.
  • the specific steps of the system disclosed in this embodiment for detecting the surface of the transparent film-like structure are described in conjunction with FIGS. 4A-4C and FIG. 5.
  • Step 510 The detection light generating unit emits the first detection light and the second detection light to the test object 300, wherein the first detection light forms the first signal light through the first surface 310, and the second detection light transmits through the first surface 310
  • the second signal light is formed by passing through the object 300 and being scattered by the second surface 320.
  • Step 520 The signal detection unit 200 collects the first signal light in an imaging manner, and forms first detection information according to the first signal light.
  • the specific operations of this step are as follows:
  • the carrying table 100 moves the object 300 to be measured to a first relative position, wherein, at the first relative position, the position 221 of the photosensitive surface of the photodetector 220 and the first surface 310 to be measured are The positions 311 are conjugated to each other. This enables the signal light collector 210 to collect the first signal light formed by the first detection light by the first surface 310 at the first position to be measured 311 (as shown by the solid line in FIG. 4A).
  • the photodetector 220 is configured to receive the first signal light transmitted by the signal light collector 210 (for example, as shown by the solid line in FIG. 4A), and generate and The first detection information corresponding to the first signal light.
  • the detection method further includes: allowing the optical displacement unit 400 to enter the optical path, so that the position 221 of the photosensitive surface of the photodetector 220 and the first position to be measured 311 of the first surface 310 are conjugate with each other, so as to facilitate the step 520 implementation.
  • Step 530 The signal detection unit 200 collects the second signal light in an imaging manner, and forms second detection information according to the second signal light.
  • the specific operations of this step are as follows:
  • the signal light collector 210 can simultaneously imagewise collect the second signal light formed by the second detection light passing through the test object 300 and being scattered by the second surface 320 (as shown by the dashed line in FIG. 4A ).
  • the optical displacement unit 400 when the distance between the image positions of the first surface and the second surface of the test object 300 is too small, the optical displacement unit 400 enters the optical path, and the photodetector 220 collects the first surface when the optical displacement unit 400 enters the optical path. Two signal light.
  • the optical displacement unit 400 is preferably arranged between the signal light collector 210 and the photodetector 220, so that the photosensitive surface of the photodetector 220
  • the position 221 and the second position to be measured 321 of the second surface 320 are conjugated with each other, so that the photodetector 220 can receive the second signal light transmitted by the signal light collector 210 based on the changed receiving path (for example, in FIG. 4B (Shown by the dashed line), and generate second detection information corresponding to the second signal light.
  • the optical displacement unit 400 is a single prism or a double wedge prism made of a transparent film material.
  • the double wedge prism includes a first wedge prism and a second wedge prism whose hypotenuses are arranged in parallel.
  • the relative distance between a wedge prism and the second wedge prism is adjustable.
  • the angle between the optical displacement unit 400 and the signal light collector 210 and the photodetector 220 depends at least on the thickness of the optical displacement sheet itself, the refractive index of the material, and the thickness of the object 300 to be measured.
  • the detection method disclosed in this embodiment further includes: separately adjusting the optical displacement unit 400 before collecting the first signal light and the second signal light, so that the signal detection unit 200 can collect the first signal light and the second signal respectively Light.
  • the distance between the first wedge prism and the second wedge prism is adjusted.
  • the detection system can also include an aperture to ensure that only the scattered light emitted by a specific surface is received, thereby eliminating the influence of non-test surface contamination or defect scattered light;
  • the detection system may also include a slit to ensure that only the scattered light emitted by a specific surface is received, thereby eliminating the influence of non-measured surface contamination or defect scattered light.
  • the optical displacement unit 400 may also be an optical displacement sheet carrying unit, which may include one or more optical displacement positions (for example, optical displacement positions 410-450) to facilitate carrying one or more optical displacement positions. A light displacement film of the same or different properties. In actual use, the optical displacement unit 400 may always be arranged in the signal detection unit 200.
  • the light displacement sheet carrying unit further has a light-passing hole, and the light displacement sheet carrying unit is also used to allow the light-passing hole to enter the light path.
  • the light displacement film bearing unit further has a rotation axis, so that the light displacement film bearing unit can drive a plurality of light displacement films and light holes to rotate around the rotation axis; wherein, a plurality of light displacement films And light holes are distributed around the axis of rotation.
  • the plurality of light displacement films and the light-passing holes are arranged along a translational line, and the light displacement sheet carrying unit is used to drive the plurality of light-displacement sheets and the light-passing holes to translate along the translational line.
  • the optical displacement unit 400 can be rotated so that the photodetector 220 passes through the first optical displacement position 410
  • the first signal light is received; at this time, the first light displacement position 410 is the position where the light-passing hole is located, so that the photodetector 220 receives the first signal light without the help of the light displacement sheet.
  • the light displacement unit 400 can be rotated so that the photodetector 220 receives the second signal light via, for example, the third light displacement position 430; A certain light displacement film is arranged in the third light displacement position 430, so that the photodetector 220 can change the receiving path with the help of the light displacement film to receive the second signal light.
  • the optical displacement unit 400 can be rotated to select the second optical displacement position 420 in the optical displacement unit 400 or the optical displacement sheet in other optical displacement positions to receive Detect the signal light on the first surface or the second surface of the test object.
  • the optical displacement sheet disclosed in Embodiments 1 and 2 is optionally a parallel flat plate, and the optical displacement sheet may be made of glass.
  • Step 540 Obtain defect information of the first surface 310 based on the first inspection information, and acquire defect information of the second surface 320 based on the second inspection information.
  • the first detection information corresponding to the first signal light and the second detection information corresponding to the second signal light respectively include the received light intensity of the first signal light and the light intensity of the second signal light.
  • the surface defect information of the test object 300 includes one or more of the following information: whether the test object 300 has a surface defect, the location of the surface defect in the presence of the surface defect, and the The size of the surface defect.
  • the wavelengths of the first detection light and the second detection light disclosed in Embodiments 1 and 2 may be the same or different.
  • the transmittance of the test object to the first detection light is less than the transmittance of the second detection light; the reflectivity of the test object to the first detection light is greater than the reflectivity of the second detection light.
  • the transparent film-like structure detected by the detection system and method disclosed herein can either exist independently or closely adhere to a certain non-transparent material (such as a transparent thick film plated on a silicon wafer).
  • Examples 1 and 2 in this article are all transparent film-like structures as an example.
  • the signal light received by the technical solution disclosed in the present invention is scattered light, and the receiving channel does not include the angle range of the reflected light, the realization principle and effect of the detection of the transparent film-like structure on the non-transparent smooth material and the full transparency
  • the film-like structure is the same, so it will not be described separately here.
  • the embodiments 1 and 2 disclosed herein can use the light scattering method to sequentially perform defect detection on the two opposite surfaces of the transparent film-like structure.
  • the detection light generating unit and the signal detection unit of the system are relatively fixed, and the object to be tested is placed on the carrying platform.
  • the carrying platform drives the object to be measured to move at a specified speed according to the specified track, so that the photodetector continuously collects signals and finally completes the test. Measurement of various positions of objects.
  • the imaging detection method used in the prior art generally requires the use of area array detectors for photoelectric detection, and the sampling rate of the area array detector is low, which limits the increase in detection speed;
  • the detection accuracy of the imaging detection method is also limited by the optical diffraction limit, so that the method can only clearly image objects with a feature size greater than half of the detection wavelength.
  • the accuracy is only on the order of a few hundred nanometers.
  • the scattered light collection method is also used in the prior art to detect defects in the semiconductor.
  • the traditional solution is to use the reflective cup collection method.
  • the detection system disclosed in the present disclosure includes: a bearing platform, a detection light generation unit, a first signal detection unit, a second signal detection unit, and an optional optical displacement unit, wherein the first signal detection unit,
  • the photodetectors included in the second signal detection unit can be line detectors or optical power meters with a higher sampling rate, and can be matched with a bearing platform that can make the object to be measured move at a specified speed according to a specified track. Compared with imaging detection methods, the detection speed is greatly improved.
  • the present invention judges the existence and size of defects based on the light intensity of the received signal light, and can detect defects in the order of tens of nanometers through noise control, which significantly improves the detection accuracy.
  • the design of the first signal detection unit and the second signal detection unit of the present invention can ensure that the positions to be measured on the two opposite surfaces of the object to be measured are respectively consistent with the photosensitive surfaces of the first signal detection unit and the second signal detection unit.
  • the position has a one-to-one correspondence, so that the simultaneous detection of two opposite surfaces of the object to be measured can be realized.
  • selective reception of scattered light formed by two opposite surface defects of the transparent film-like structure is realized.
  • the detection system disclosed herein includes: a carrier 100, a detection light generating unit (not shown in the drawings), a first signal detection unit 700, and a second signal detection unit 800.
  • the carrying platform 100 is configured to carry the object 600 to be tested, and the carrying platform 100 includes a carrying surface for placing the object 600 to be tested.
  • the detection light generating unit is configured to emit the first detection light and the second detection light (that is, the incident light in FIGS. 6 and 7) to the object to be measured 600, wherein the object to be measured 600 includes a first surface disposed opposite to each other.
  • the first signal detection unit 700 is configured to collect the first signal light and generate first detection information according to the first signal light; the second signal detection unit 800 is configured to collect the second signal light and generate the first detection information according to the second signal light 2. Detection information.
  • the incident direction of the first detection light and the second detection light form a first angle ⁇ between the normal direction of the object 600, and the normal direction of the first signal detection unit 700 is relative to the normal direction of the object 600.
  • the normal direction of the object 600 forms a second angle ⁇
  • the normal direction of the second signal detection unit 800 and the normal direction of the object 600 form a third angle ⁇ .
  • the absolute value of the second angle ⁇ and the absolute value of the third angle ⁇ are different from the absolute value of the first angle ⁇ , that is, the first signal detection unit 700, the second signal
  • the detection unit 800 only receives the scattered light formed by the position to be measured of the object 600 to be measured, and does not receive the reflected light formed by the position to be measured of the object 600 to be measured.
  • the absolute value of the second angle ⁇ is the same as the absolute value of the third angle ⁇ .
  • the absolute value of the second angle ⁇ and the absolute value of the third angle ⁇ may also be different.
  • the first signal detection unit 700 includes: a first signal light collector 710 and a first photodetector 720.
  • the first signal light collector 710 is configured to collect the first signal light
  • the first photodetector 720 is configured to receive the first signal light transmitted by the first signal light collector 710, and generate according to the first signal light The first detection information.
  • the position 721 of the photosensitive surface of the first photodetector 720 and the position to be measured 611 of the first surface 610 are conjugated with each other, that is, the first surface 610 is the object plane, and the first photodetector 720 is at The corresponding image plane. Further, the normal direction of the first signal light collector 710 and the normal direction of the object 600 are at a second angle ⁇ .
  • the second signal detection unit 800 includes: a second signal light collector 810 and a second photodetector 820.
  • the second signal light collector 810 is configured to collect the second signal light
  • the second photodetector 820 is configured to receive the second signal light transmitted by the second signal light collector, and according to the second signal light The signal light generates second detection information.
  • the position 821 of the photosensitive surface of the second photodetector 820 and the position to be measured 621 of the second surface 620 are conjugate with each other, that is, the second surface 620 is the object plane, and the second photodetector 820 is in the object plane.
  • the normal direction of the second signal light collector 810 and the normal direction of the object 600 are at a third angle ⁇ .
  • the detection system may include more signal detection units, and more signal detection units are used to detect the first signal light and the second signal light of different azimuth angles.
  • the detection light generating unit is a point light spot generator or a line light spot generator.
  • the first photodetector 720 and the second photodetector 820 are optical power meters, so as to detect the surface of the object to be measured by means of spot scanning;
  • the detection light generating unit is a line spot generator, the first photodetector 720 and the second photodetector 820 are line detectors, so as to detect the surface of the object to be measured in a line scan detection manner.
  • the working principle of the system disclosed in this embodiment is specifically as follows: when the first detection light and the second detection light (for example, the incident light in FIG. 6 and FIG. 7) respectively enter the object 600
  • the thickness of is small, so the incident light of its two opposite surfaces (that is, the first surface 610 and the second surface 620) has a better convergence.
  • all the inspection light will be transmitted from the object to be measured 600, and the transmitted light will be transmitted to the carrying table 100 at the bottom and then reflected to the object to be measured 600 at the same angle (for example, Figure 6, Figure 6). 7), while the first signal light collector 710 and the second signal light collector 810 can only detect very weak noise.
  • the defect causes the detection light to be scattered, and the scattered light is transmitted toward all directions of the measured object 600, within a certain angular range of the measured object 600 avoiding the reflected light (for example,
  • the second angle ⁇ , the third angle ⁇ ) are respectively provided with the first signal detection unit 700 and the second signal detection unit 800, so that the first signal detection unit 700 and the second signal detection unit 800 respectively collect scattered light in a specific spatial angle, And detect and process the scattered light.
  • the scattered light generated by the two defects is respectively transferred to the first signal light collector 710 and the second signal light collector 810. collect.
  • the position of the photosensitive surface of the first photodetector 720 and the position to be measured on the first surface 610 are conjugate with each other, so the first photodetector 720 can only receive the scattered light formed by the first surface 610 ( For example, the scattered light shown in FIG. 7); the position of the photosensitive surface of the second photodetector 820 and the position to be measured on the second surface 620 are conjugate with each other, then the second photodetector 820 can only receive the second detection light.
  • the scattered light (for example, the scattered light shown in FIG. 7) formed by the object 600 through the second surface 620 is passed.
  • Step 1010 the detection light generating unit simultaneously emits the first detection light and the second detection light to the object 600 to be measured, wherein the first detection light is scattered by the first surface 610 to form first signal light, and the second detection light The first surface 610 passes through the object 600 and is scattered by the second surface 620 to form a second signal light.
  • the detection system further includes a mobile device for moving at least two of the first signal detection unit 700, the second signal detection unit 800, and the carrier 100, where the first signal detection The unit 700 moves in the first direction, the second signal detection unit 800 moves in the second direction, and the carrier 100 moves in the third direction, so that the first signal detection unit 700 and the second signal detection unit 800 can be treated separately.
  • a mobile device for moving at least two of the first signal detection unit 700, the second signal detection unit 800, and the carrier 100, where the first signal detection The unit 700 moves in the first direction, the second signal detection unit 800 moves in the second direction, and the carrier 100 moves in the third direction, so that the first signal detection unit 700 and the second signal detection unit 800 can be treated separately.
  • Accurate detection of the first surface 610 and the second surface 620 of the object 600 wherein, the included angle between the first direction, the second direction, and the third direction and the bearing surface of the bearing platform 100 is greater than zero.
  • Step 1020 The first signal detection unit 700 collects the first signal light, and generates the first detection information according to the first signal light; the specific operations of this step are as follows:
  • the first signal light collector 710 collects the first signal light from the first position to be measured 611 on the first surface 610;
  • the first photodetector 720 receives the first signal light based on the first receiving path formed by the relative position of the first photodetector 720 and the first signal light collector 710, and generates the first detection information. Specifically, the position 721 of the photosensitive surface of the first photodetector 720 and the first position 611 of the object to be measured 600 are conjugated with each other, so as to receive the first signal light and generate the first detection information.
  • Step 1030 The second signal detection unit 600 collects the second signal light, and generates second detection information according to the second signal light; the specific operation of this step is as follows:
  • the second signal light collector 810 collects the second signal light from the second position to be measured 621 on the second surface 620;
  • the second photodetector 820 receives the second signal light based on the second receiving path formed by the relative position of the second photodetector 820 and the second signal light collector 810, and generates the second detection information.
  • the position 821 of the photosensitive surface of the second photodetector 820 and the second position 621 of the object to be measured 600 are conjugated with each other, so as to receive the second signal light and generate the second detection information.
  • steps 1020 and 1030 can be performed simultaneously or in other order.
  • the first detection information includes the light intensity of the first signal light
  • the second detection information includes the light intensity of the second signal light
  • the surface defect information of the test object 600 includes one or more of the following information Item: Whether there is a surface defect in the test object 600, the location of the surface defect, and the size of the surface defect if there is a surface defect.
  • the positions of the first signal detection unit 700 and the second signal detection unit 800 relative to the detection light generating unit are fixed, that is, the first signal detection unit in this embodiment
  • the unit 700 and the second signal detection unit 800 can only collect scattered light emitted from a fixed height and a fixed position.
  • the first photodetector 720 in the first signal detection unit 700 can only receive and detect scattered light from the first surface 610 of the object 600; the second photodetector 720 in the second signal detection unit 800
  • the photodetector 820 can only receive and detect the scattered light of the second surface 620 of the object 600, thereby eliminating the detection interference between different surfaces of the object 600, and can also realize the detection of the two surfaces of the object 600. Simultaneous detection.
  • the detection system disclosed in this embodiment is similar to the system disclosed in Embodiment 3. Therefore, similar or identical components in the system disclosed in this embodiment will not be repeated here.
  • the detection system disclosed in this embodiment further includes an optical displacement unit 850 configured to change the imaging position of the position to be measured on the first surface or the second surface of the object to be measured.
  • the disclosed detection system may also include two light displacement units, for example, a first light displacement unit and a second light displacement unit, so that the first light displacement unit is used to change the target surface of the first surface of the object to be measured.
  • the imaging position of the measuring position is such that the second optical displacement unit is used to change the imaging position of the measuring position of the second surface of the object to be measured.
  • the first signal light collector 710 is used to collect the first signal light, and the first signal light is converged to the first photodetector 720 through the first light displacement unit; the second signal light collector 810 is used to collect The second signal light is converged to the second photodetector 820 through the second light displacement unit.
  • the first optical displacement unit is configured to adjust the amount of change in the imaging position of the position to be measured on the first surface of the object to be measured
  • the second optical displacement unit is configured to make the second The amount of change in the imaging position of the position to be measured on the surface is adjustable.
  • the thickness and/or material of the second test object 900 to be detected is different from the thickness and/or material of the test object 600, when the first surface 910 of the second test object 900 is When there are defects in the corresponding positions of the second surface 920, when the positions of the first signal detection unit 700 and the second signal detection unit 800 are fixed, the two cannot separately perform the detection of the second test unit based on the original design. Detection of the first surface 910 and the second surface 920 of the object 900.
  • the system disclosed in this embodiment further includes an optical displacement unit 850, which is configured to enable the first photodetector 720 collects the first signal light when the optical displacement unit 850 enters and exits the optical path, or enables the second photodetector 820 to collect the second signal light when the optical displacement unit 850 enters and exits the optical path, so that the second test object 900 can be
  • the first surface 910 and the second surface 920 are detected separately.
  • Step 1010 The detection light generating unit simultaneously emits the first detection light and the second detection light to the second test object 900, where the second test object 900 includes a first surface 910 and a second surface 920 that are opposed to each other.
  • the detection light is scattered by the first surface 910 to form the first signal light
  • the second detection light is scattered from the first surface 910 through the second test object 900 and scattered by the second surface 920 to form the second signal light.
  • this embodiment further includes adopting an optical displacement unit to change the receiving path of the first signal light or the second signal light based on the thickness and/or material of the second object to be measured 900; the specific operation is as follows :
  • Make the first optical displacement unit change the imaging position of the position to be measured 911 of the first surface 910 of the second object to be measured 900, or make the second optical displacement unit change the position to be measured of the second surface 920 of the second object to be measured 900 921 imaging position.
  • the optical displacement unit 850 is arranged in the second signal detection unit 800 (as shown in FIG. 8A). As shown, in this embodiment, preferably, the optical displacement unit 850 is disposed between the second signal light collector 810 and the second photodetector 820), so that the second test position of the second test object 900 is 921 is conjugated to the position 921 of the second photosensitive surface of the second photodetector 920, thereby realizing the change of the signal light collection position.
  • the optical displacement unit 850 is arranged in the first signal detection unit 700, so that the position to be measured 911 of the first surface 910 of the second object to be measured 900 and the first photodetector 720 are The position 721 of the photosensitive surface is conjugated to realize the change of the collection position of the signal light.
  • the light displacement unit 850 may also be a light displacement sheet carrying unit, which may include one or more light displacement positions (for example, light displacement positions 851-855). , In order to carry one or more identical or different optical displacement films. In actual use, the optical displacement unit 850 may always be arranged in the second signal detection unit 800 and/or the first signal detection unit 700.
  • the light displacement film carrying unit further has a light-passing hole, and the light-displacement film carrying unit is also used to make the light-displacement sheet carrying unit enter the light path.
  • the light displacement film bearing unit further has a rotation axis, so that the light displacement film bearing unit can drive a plurality of light displacement films and light holes to rotate around the rotation axis; wherein, a plurality of light displacement films And light holes are distributed around the axis of rotation.
  • the plurality of light displacement films and the light-passing holes are arranged along a translational line, and the light displacement sheet carrying unit is used to drive the plurality of light-displacement sheets and the light-passing holes to translate along the translational line.
  • the second light displacement sheet carrying unit provided in the second signal detection unit 800 can be rotated, so that the second photodetector 820 receives the light via the first light displacement position 851, for example.
  • the second signal light; at this time, the first light displacement position 851 is the position of the light through hole, so that the second photodetector 820 can receive the second signal light without the help of the light displacement sheet; at the same time, it can be rotated and set in the first light
  • a first light displacement sheet carrying unit in the signal detection unit 700 enables the first photodetector 720 to receive the first signal light via, for example, the third light displacement position 853; at this time, a certain light displacement is provided in the third light displacement position 853
  • This kind of light displacement film realizes that the first photodetector 720 receives the first signal light with the help of the light displacement film.
  • the second light displacement sheet carrying unit provided in the second signal detection unit 800 can be rotated, so that the second photodetector 820 passes through, for example, the fourth light displacement position. 854 receives the second signal light; at this time, some kind of light displacement film is arranged in the fourth light displacement position 854, so that the second photodetector 820 receives the second signal light with the help of the light displacement film; at the same time, it can rotate
  • the first light displacement sheet carrying unit 850 arranged in the first signal detection unit 700 enables the first photodetector 720 to receive the first signal light via the fifth light displacement position 855; at this time, in the fifth light displacement position 855 No light displacement sheet is provided, so that the first photodetector 720 receives the first signal light without the help of the light displacement sheet.
  • the optical displacement units can be provided in the first signal detection unit 700 and the second signal detection unit 800 respectively.
  • the first light displacement unit and the second light displacement unit so that the first photodetector 720 and the second photodetector 820 receive the first signal light and the second signal light via the corresponding light displacement unit, respectively.
  • optical displacement unit 850 can further improve the flexibility of use of the disclosed device.
  • the detection system can also include an aperture to ensure that only the scattered light emitted by a specific surface is received, thereby eliminating the influence of non-test surface contamination or defect scattered light;
  • the detection system may also include a slit to ensure that only the scattered light emitted by a specific surface is received, thereby eliminating the influence of non-measured surface contamination or defect scattered light.
  • the optical displacement unit 850 is an optical displacement sheet made of a transparent film material.
  • the angle between the optical displacement sheet and the first signal light collector 710 and the first photodetector 720 or the second signal light collector 810, The angle between the second photodetectors 820 depends at least on the thickness of the light displacement sheet itself, the refractive index of the material, and the thickness of the second object 900 under test.
  • the optical displacement unit 850 may be a single prism or a double wedge prism.
  • the double wedge prism includes a first wedge prism and a second wedge prism with the hypotenuse parallel to each other.
  • the first wedge prism and the second wedge prism The relative distance of the two wedge prisms is adjustable.
  • the optical displacement sheet disclosed in Embodiments 3 and 4 is optionally a parallel flat plate, and the optical displacement sheet may be made of glass.
  • the respective adjustments to the optical displacement unit are specifically as follows: adjusting the distance between the first wedge-shaped prism and the second wedge-shaped prism.
  • Step 1020 The first signal detection unit 700 collects the first signal light, and generates first detection information according to the first signal light; the specific operations of this step are as follows:
  • the first signal light collector 710 collects the first signal light
  • the first photodetector 720 receives the first signal light based on the first receiving path formed by the first photodetector 720 and the set position of the first signal light collector 710 (as shown by the solid line in FIG. 8A). Light), and generate the first detection information.
  • the first photodetector 720 receives the first signal light via the optical displacement unit 850 and generates The first detection information.
  • Step 1030 The second signal detection unit 800 collects the second signal light, and generates second detection information according to the second signal light; the specific operations of this step are as follows:
  • the second signal light collector 810 collects the second signal light
  • the second photodetector 820 receives the second signal light (scattered light as shown by the dotted line in FIG. 8A) based on the second receiving path formed by the second photodetector 820 and the second signal light collector 810 at the set position. ), and generate the second detection information.
  • the second photodetector 820 receives the second signal light via the optical displacement unit 850 and generates the The second detection information.
  • the first detection information is associated with the received light intensity of the first signal light
  • the second detection information is associated with the light intensity of the second signal light
  • the surface defect information of the second test object 900 includes one or more of the following information: whether the second test object 900 has a surface defect, the location of the surface defect and the location of the surface defect if there is a surface defect size.
  • step 1020 and step 1030 are performed at the same time, so as to realize the simultaneous detection of two opposite surfaces of the second test object 900.
  • the optical displacement unit 850 is added between the first signal light collector 710 and the first photodetector 720 or the optical displacement is added between the second signal light collector 810 and the second photodetector 820.
  • the unit 850 changes the transmission direction and phase of the signal light transmitted to the first photodetector 720 or the second photodetector 820, thereby realizing the change of the imaging position, and further realizing the detection of multiple surfaces of transparent film-like structures of different materials. Simultaneous detection.
  • the wavelengths of the first detection light and the second detection light disclosed in Embodiments 3 and 4 may be the same or different.
  • the transmittance of the test object to the first detection light is less than the transmittance of the second detection light; the reflectivity of the test object to the first detection light is greater than the reflectance of the second detection light.
  • the transparent film-like structure detected by the detection system and method disclosed herein can either exist independently or closely adhere to a certain non-transparent material (such as a transparent thick film plated on a silicon wafer).
  • Examples 3 and 4 in this article are all transparent film-like structures as an example.
  • For the transparent film-like structure closely attached to a non-transparent smooth material most of the detection light is incident on the object to be measured. The material is not reflected by the carrying platform. Since the signal light received by the technical solution disclosed in the present invention is scattered light, and the receiving angle does not include the range of the reflected light angle, the realization principle and effect of the detection of the transparent film-like structure on the non-transparent smooth material is consistent with the full transparency.
  • the film-like structure is the same, so it will not be described separately here.
  • the embodiments 3 and 4 disclosed herein can use the light scattering method to simultaneously perform defect detection on the two opposite surfaces of the transparent film-like structure.
  • the detection light generating unit of the system is relatively fixed with the first signal detection unit and the second signal detection unit.
  • the object to be tested is placed on the carrying platform.
  • the carrying platform drives the object to be measured to move at a specified speed according to a specified trajectory, so that the first The photodetector and the second photodetector continuously collect signals and finally complete the measurement of each position of the object to be measured.

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Abstract

L'invention concerne un système et un procédé de détection, le système de détection comprenant : une unité de génération de lumière de détection, une unité de détection de signal et une unité de traitement. L'unité de génération de lumière de détection est conçue pour émettre une seconde lumière de détection vers un objet à détecter, l'objet à détecter comprenant une première surface et une seconde surface disposées en regard l'une de l'autre et la seconde lumière de détection traversant l'objet à détecter à partir de la première surface et étant diffusée par la seconde surface pour former une seconde lumière de signal; l'unité de détection de signal est conçue pour collecter la seconde lumière de signal au moyen d'une imagerie et pour générer des secondes informations de détection en fonction de la seconde lumière de signal; et l'unité de traitement est conçue pour acquérir des informations de défaut de la seconde surface sur la base des secondes informations de détection. Par rapport à la technologie existante, lors de la détection d'une surface d'une structure de film transparent, la présente invention présente des avantages tels que la vitesse de détection rapide et la précision du résultat de détection élevée.
PCT/CN2020/116188 2019-09-20 2020-09-18 Système de détection et procédé de détection WO2021052463A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
CN201910892691.3 2019-09-20
CN201910892194.3A CN112540082A (zh) 2019-09-20 2019-09-20 检测系统及检测方法
CN201910892194.3 2019-09-20
CN201910892691.3A CN112540083A (zh) 2019-09-20 2019-09-20 检测系统及基于检测系统的检测方法

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7274445B1 (en) * 2005-03-11 2007-09-25 Kla-Tencor Technologies Corporation Confocal scatterometer and method for single-sided detection of particles and defects on a transparent wafer or disk
CN101473218A (zh) * 2006-05-12 2009-07-01 康宁股份有限公司 用于表征透明基底中的缺陷的装置和方法
CN102778460A (zh) * 2012-07-31 2012-11-14 法国圣戈班玻璃公司 一种检测基质内缺陷的方法
US20160327494A1 (en) * 2015-05-08 2016-11-10 Nanoprotech Co., Ltd. Upper Surface Foreign Material Detecting Device of Ultra-Thin Transparent Substrate

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7274445B1 (en) * 2005-03-11 2007-09-25 Kla-Tencor Technologies Corporation Confocal scatterometer and method for single-sided detection of particles and defects on a transparent wafer or disk
CN101473218A (zh) * 2006-05-12 2009-07-01 康宁股份有限公司 用于表征透明基底中的缺陷的装置和方法
CN102778460A (zh) * 2012-07-31 2012-11-14 法国圣戈班玻璃公司 一种检测基质内缺陷的方法
US20160327494A1 (en) * 2015-05-08 2016-11-10 Nanoprotech Co., Ltd. Upper Surface Foreign Material Detecting Device of Ultra-Thin Transparent Substrate

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