WO2021052463A1

WO2021052463A1 - Detection system and detection method

Info

Publication number: WO2021052463A1
Application number: PCT/CN2020/116188
Authority: WO
Inventors: 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
Priority date: 2019-09-20
Filing date: 2020-09-18
Publication date: 2021-03-25

Abstract

Disclosed are a detection system and method, the detection system comprising: a detection light generating unit, a signal detection unit and a processing unit. The detection light generating unit is configured to emit second detection light toward an object to be detected, the object to be detected comprising a first surface and a second surface which are oppositely provided, and the second detection light passing through the object to be detected from the first surface and being scattered by the second surface to form second signal light; the signal detection unit is configured to collect the second signal light by means of imaging and to generate second detection information according to the second signal light; and the processing unit is configured to acquire defect information of the second surface on the basis of the second detection information. In comparison with the existing technology, when detecting a surface of a transparent film structure, the present invention has advantages such as detection speed being fast and the precision of the detection result being high.

Description

Detection system and detection method

Technical field

The invention relates to the field of high-precision defect detection, in particular to a detection system and a detection method.

Background technique

With the development of modern industry, 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.

At present, scattered light detection is the main method for high-precision defect detection in the existing semiconductor industry. However, 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.

In addition, the optical imaging method is also a common method for semiconductor defect detection. However, due to the limitation of the optical diffraction limit, 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.

Summary of the invention

In view of the above-mentioned problems, 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; and

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;

Collecting the second signal light in an imaging manner, and generating second detection information according to the second signal light; and

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. Through the design of the signal detection unit and other components, 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; and

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;

Collecting the first signal light by the first signal detection unit, and generating first detection information according to the first signal light; and

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. Through the design of the first signal detection unit, the second signal detection unit and other components, 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.

Description of the drawings

The embodiments are shown and clarified with reference to the drawings. These drawings are used to clarify the basic principle, so that only the aspects necessary for understanding the basic principle are shown. The drawings are not to scale. In the drawings, the same reference numerals indicate similar features.

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;

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;

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;

8B is a schematic structural diagram of the optical displacement unit of the detection system according to the present invention; and

Fig. 9 is a flowchart of a detection method based on a detection system according to the present invention.

detailed description

Hereinafter, various exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The flowcharts and block diagrams in the drawings illustrate the possible implementation architecture, functions, and operations of the methods and devices according to various embodiments of the present disclosure. It should be noted that 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. It should also be noted that, in some alternative implementations, the functions marked in the block 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. It should also be noted that 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 technologies, methods, and equipment known to those of ordinary skill in the relevant fields may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be regarded as part of the specification. The connection between the units in the drawings is only for convenience of description, which means that at least the units at both ends of the connection communicate with each other, and it is not intended to limit the communication between unconnected units.

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. However, when the object to be measured is a transparent film structure, when there are defects on the two opposite surfaces of the object to be measured If scattered light will be formed at the same time, 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.

In order to solve the above-mentioned problems, 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. In addition, 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. In addition, based on the cooperation of the signal detection unit and the carrying table or the optical displacement unit, selective reception of scattered light formed by two opposite surface defects of the transparent film-like structure is realized.

Example 1

As shown in Figure 1, Figure 3A and Figure 3B, 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). Wherein, 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. 310 penetrates the object to be measured 300 and is scattered by the second surface 320 to form the second signal light; 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.

In this embodiment, the distance between the bearing surface of the bearing platform 100 and the signal detection unit 200 in the first direction is adjustable, and the first direction is not perpendicular to the optical axis of the signal detection unit 200. In addition, in this embodiment, the detection system further includes a control unit configured to control the relative movement between the carrier 100 and the signal detection unit 200.

As shown in FIG. 1, the incident direction of the detection light and the normal direction of the object 300 are at a first angle α, and 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 β. In the present invention, the absolute value of the second angle β is different from the absolute value of the first angle α, 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.

As shown in FIG. 1, FIG. 3A and FIG. 3B, the signal detection unit 200 includes: a signal light collector 210 and a photodetector 220. Wherein, 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.

In this embodiment, 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.

In this embodiment, as shown in FIG. 1, the normal direction of the signal light collector 210 and the normal direction of the test object 300 form the second angle β.

In this embodiment, 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 When the detection light generating unit is a line spot generator, 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.

As shown in FIG. 1, 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. In the case of 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) and the signal light collector 210 can only detect very weak noise. 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 β) is provided with a signal detection unit 200, which collects scattered light in a specific spatial angle, and detects and processes the scattered light.

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. However, when the photodetector 220 is designed to be in a certain position, 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).

In order to realize the separate detection of the first surface 310 and the second surface 320 of the object to be tested 300, 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. 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:

As shown in FIG. 3A, first, 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.

Specifically, the 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.

When the object 300 is in the first relative position, the first surface 310 is the object plane, and 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:

As shown in FIG. 3B, 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.

Specifically, the 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.

When the object to be measured 300 is in the second relative position, the second surface 320 is the object plane, the photodetector 220 is in the corresponding image plane, and 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.

In this embodiment, 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.

In this embodiment, 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.

In Embodiment 1, 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. At the same time, in this embodiment, 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. In other embodiments, 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.

Example 2

As shown in Figures 2 and 4A-4C, 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. . In addition, 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. However, when the photodetector 220 is designed to be in a certain position, 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).

In order to realize the separate detection of the first surface 310 and the second surface 320 of the object to be measured 300, 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.

As shown in FIG. 4A, 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).

When the object to be measured 300 is in the first relative position, 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.

Alternatively, before step 520, 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.

As shown in FIG. 4A, 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 ).

In the present invention, 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.

As shown in FIG. 4B, when the object 300 is in the first relative position, 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.

In this embodiment, 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. In addition, 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.

Optionally, 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.

Specifically, the distance between the first wedge prism and the second wedge prism is adjusted.

In specific use, when the detection light generating unit is a spot light spot generator, 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; When the detection light generating unit is a line spot generator, 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. In addition, as shown in FIG. 4C, 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.

In this embodiment, 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.

Specifically, in this embodiment, 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. In other embodiments, 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.

Specifically, in this embodiment, when the signal detection unit 200 is at the first height and detects the first surface 310 of the object 300, 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. When the signal detection unit 200 is at the first height and detects the second surface 320 of the object 300, 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. By analogy, when the material and/or refractive index of the object to be measured changes, 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. Thus, the flexibility of using the device disclosed herein is improved.

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.

In this embodiment, 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. Strong. In addition, 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. For a transparent film-like structure clinging 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 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. During the detection, 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 embodiments of the present disclosure also pay attention to the following technical problems: 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; 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. However, when the object to be tested is a transparent film structure, the traditional solution is to use the reflective cup collection method. When there are defects on the two opposite surfaces of the object, scattered light will be formed at the same time, so the existing reflector cup collection method cannot distinguish that the scattered signal comes from the specific position of the transparent film-like structure, that is, the existing reflector cup collects The method cannot get accurate test results.

In order to solve the above-mentioned problems, 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. In addition, 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. In addition, 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. Further, based on the cooperation of the first signal detection unit, the second signal detection unit and the carrying platform or the optical displacement unit, selective reception of scattered light formed by two opposite surface defects of the transparent film-like structure is realized.

Example 3

As shown in Figures 6 and 7, 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. Wherein, 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. 610 and the second surface 620, the first detection light is scattered by the first surface 610 to form the first signal light, and the second detection light passes through the object 600 from the first surface 610 and is scattered by the second surface 620 to form the second signal light . 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.

As shown in FIG. 6, the incident direction of the first detection light and the second detection light form a first angle α 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 β, and the normal direction of the second signal detection unit 800 and the normal direction of the object 600 form a third angle θ. In the present invention, the absolute value of the second angle β and the absolute value of the third angle θ are different from the absolute value of the first angle α, 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.

In this embodiment, it is preferable that the absolute value of the second angle β is the same as the absolute value of the third angle θ. In practical applications, the absolute value of the second angle β and the absolute value of the third angle θ may also be different.

As shown in FIG. 6 and FIG. 7, the first signal detection unit 700 includes: a first signal light collector 710 and a first photodetector 720. Wherein, 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.

In this embodiment, 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 β.

In addition, as shown in FIGS. 6 and 7, the second signal detection unit 800 includes: a second signal light collector 810 and a second photodetector 820. Wherein, 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.

In this embodiment, 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 corresponding image plane. Further, the normal direction of the second signal light collector 810 and the normal direction of the object 600 are at a third angle θ.

In this embodiment, 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.

In this embodiment, the detection light generating unit is a point light spot generator or a line light spot generator. In the case that the detection light generating unit is a spot 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; In the case that 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. 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 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. When there is a defect in the illuminated position to be measured, 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 β, the third angle θ) 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.

If there are defects in the corresponding positions of the first surface 610 and the second surface 620 of the object to be measured 600, 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. In this embodiment, 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.

In order to realize the simultaneous detection of the first surface 610 and the second surface 620 of the test object 600, the specific steps of the system disclosed in this embodiment for detecting the surface of the transparent film-like structure will be described with reference to FIG. 6, FIG. 7, and FIG.

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.

In this embodiment, 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. 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:

First, the first signal light collector 710 collects the first signal light from the first position to be measured 611 on the first surface 610;

Secondly, 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:

First, the second signal light collector 810 collects the second signal light from the second position to be measured 621 on the second surface 620;

Secondly, 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. Specifically, 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.

In this embodiment, steps 1020 and 1030 can be performed simultaneously or in other order.

In this embodiment, the first detection information includes the light intensity of the first signal light, and 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. In Embodiment 3, the positions of the first signal detection unit 700 and the second signal detection unit 800 relative to the detection light generating unit (not shown in the figure) 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. At the same time, in this embodiment, 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.

Example 4

As shown in FIG. 8A, 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. In addition, 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.

In addition, 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. Then 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. Further, 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, and 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.

As shown in FIG. 8A, if 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.

In order to realize the simultaneous detection of the first surface 910 and the second surface 920 of the second test 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. The specific steps of the system disclosed in this embodiment for detecting the surface of the transparent film-like structure will be described below with reference to FIGS. 8A, 8B and 9.

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, and 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.

Before step 1020, 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.

In the present invention, when the imaging position of the position to be measured 921 of the second surface 920 of the second object to be measured 900 is to be changed, 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.

In actual use, there may also be cases where the imaging position of the position to be measured 911 on the first surface 910 of the second object to be measured 900 needs to be changed. In this case, 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.

In addition, in this embodiment, as shown in FIG. 8B, 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.

In this embodiment, 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.

For example, when the receiving path of the first signal light is to be changed, 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.

By analogy, when the receiving path of the second signal light is to be changed, 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.

In addition, when the imaging positions of the position to be measured on the first surface and the second surface of the second object to be measured both need to be changed, the optical displacement units can be provided in the first signal detection unit 700 and the second signal detection unit 800 respectively. (For example, 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.

It can be seen from this that the optical displacement unit 850 disclosed herein can further improve the flexibility of use of the disclosed device.

In specific use, when the detection light generating unit is a spot light spot generator, 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; When the detection light generating unit is a line spot generator, 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. In this embodiment, 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.

Therefore, before collecting the first signal light and the second signal light, 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:

First, the first signal light collector 710 collects the first signal light;

Secondly, 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.

In addition, in this embodiment, if the optical displacement unit 850 is used to change the imaging position of the position to be measured 911 of the first surface 910, 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:

First, the second signal light collector 810 collects the second signal light;

Secondly, 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.

In addition, in this embodiment, if the optical displacement unit 850 is used to change the imaging position of the position to be measured 921 of the second surface 920, the second photodetector 820 receives the second signal light via the optical displacement unit 850 and generates the The second detection information.

In this embodiment, the first detection information is associated with the received light intensity of the first signal light, and the second detection information is associated with the light intensity of the second signal light. In addition, 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.

In this embodiment, 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.

In Embodiment 4, 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. During the detection, 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.

The foregoing descriptions are only optional embodiments of the embodiments of the present disclosure, and are not used to limit the embodiments of the present disclosure. For those skilled in the art, the embodiments of the present disclosure may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiments of the present disclosure should be included in the protection scope of the embodiments of the present disclosure.

Although the embodiments of the present disclosure have been described with reference to several specific embodiments, it should be understood that the embodiments of the present disclosure are not limited to the specific embodiments disclosed. The embodiments of the present disclosure are intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The scope of the appended claims accords with the broadest interpretation, so as to include all such modifications and equivalent structures and functions.

Claims

A detection system, characterized in that the system 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; and

The processing unit is configured to obtain defect information of the second surface based on the second detection information.
The detection system according to claim 1, wherein:

The detection light generating unit is further configured to emit first detection light to the object to be measured, and the first detection light is scattered by the first surface to form first signal light;

The signal detection unit is further configured to collect the first signal light in an imaging manner, and form first detection information according to the first signal light;

The processing unit is further configured to obtain defect information of the first surface based on the first detection information.
The detection system according to claim 1, further comprising a carrying platform configured to carry the object to be tested; the carrying surface of the carrying platform and the signal along the first direction The distance between the detection units is adjustable, and the first direction is not perpendicular to the optical axis of the signal detection unit.
The detection system according to claim 3, further comprising a control unit configured to control the relative movement between the bearing platform and the signal detection unit;

The control unit is further configured to enable the object to be measured and the signal detection unit to have a first relative position, wherein, at the first relative position, the position of the photosensitive surface of the signal detection unit is relative to the first relative position. The positions to be measured on a surface are conjugate with each other; and/or

The control unit is further configured to enable the object to be measured and the signal detection unit to have a second relative position, wherein, at the second relative position, the position of the photosensitive surface of the signal detection unit is relative to the first relative position. The positions to be measured on the two surfaces are conjugate to each other.
The detection system according to claim 2, wherein the system further comprises:

The optical displacement unit is configured to change the imaging position of the position to be measured on the first surface and/or the second surface.
The detection system according to claim 5, wherein the signal detection unit comprises: a signal light collector and a photodetector, and the signal light collector is configured to collect the first signal light and the Second signal light, and converge the first signal light or the second signal light to the photodetector via the optical displacement unit.
The detection system according to claim 5, wherein:

The optical displacement unit is further configured to enable the signal detection unit to collect the first signal light and the second signal light when the optical displacement unit enters and exits the optical path; or

The optical displacement unit is further configured to adjust the amount of change in the imaging position of the position to be measured on the first surface and/or the second surface.
The detection system according to claim 5, wherein the optical displacement unit comprises a single prism or a double wedge prism, and the double wedge prism comprises a first wedge prism and a second wedge prism whose hypotenuses are arranged in parallel.
The detection system according to claim 8, wherein the relative distance between the first wedge prism and the second wedge prism is adjustable.
The detection system according to claim 5, wherein the optical displacement unit comprises an optical displacement sheet carrying unit and a plurality of optical displacement sheets located in the optical displacement sheet carrying unit, and the plurality of optical displacement sheets are aligned with each other. The amount of change in the propagation direction of the first signal light or the second signal light is different, and the light displacement sheet bearing unit is configured to allow different light displacement sheets to enter the optical path.
10. The detection system according to claim 10, wherein 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 detection system according to claim 2, wherein the wavelengths of the first detection light and the second detection light are the same or different.
The detection system according to claim 6, wherein the detection light generating unit is a point light spot generator or a line light spot generator, and when the detection light generating unit is a point light spot generator, the The photodetector is an optical power meter; when the detection light generating unit is a line spot generator, the photodetector is a line detector.
The detection system according to claim 1, wherein the second detection information includes the light intensity of the second signal light;

The surface defect information of the test object includes one or more of the following information: whether the test object has a surface defect, and the size of the surface defect if the surface defect exists.
A detection method, characterized in that the method 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;

Collecting the second signal light in an imaging manner, and generating second detection information according to the second signal light; and

The defect information of the second surface is acquired based on the second detection information.
The detection method according to claim 15, wherein the method further comprises:

Emitting a first detection light to the object to be measured, and the first detection light is scattered by the first surface to form a first signal light;

Collecting the first signal light in an imaging manner, and forming first detection information according to the first signal light; and

The defect information of the first surface is acquired based on the first detection information.
The detection method according to claim 16, characterized in that, before emitting the first detection light to the object to be measured, the method further comprises:

The object to be measured and the signal detection unit are in a first relative position, wherein at the first relative position, the position of the photosensitive surface of the signal detection unit and the position to be measured on the first surface are the same as each other. yoke.
The detection method according to claim 15, characterized in that, before the second detection light is emitted to the object to be measured, the method further comprises:

The object to be measured and the signal detection unit are in a second relative position, wherein, at the second relative position, the position of the photosensitive surface of the signal detection unit and the position to be measured on the second surface are the same as each other. yoke.
The detection method according to claim 16, wherein:

Before imaging the first signal light, the method includes: making a light displacement unit enter the light path, and before imaging the second signal light, the method includes: moving the light displacement unit out of the light path; or

Before imaging the second signal light, the method includes: making the light displacement unit enter the optical path;

The detection method further includes: before collecting the first signal light and the second signal light, respectively adjusting the optical displacement unit, so that the signal detection unit collects the first signal light and the second signal light. Two signal light.
The detection method according to claim 19, wherein the optical displacement unit is a double wedge prism, and the double wedge prism comprises a first wedge prism and a second wedge prism with the hypotenuse arranged in parallel, wherein the first wedge prism The relative distance between a wedge prism and the second wedge prism is adjustable;

The step of separately adjusting the optical displacement unit before collecting the first signal light and the second signal light includes:

Adjust the distance between the first wedge prism and the second wedge prism.
A detection system, characterized in that the system 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; and

The second signal detection unit is configured to collect the second signal light and generate second detection information according to the second signal light.
The detection system according to claim 21, wherein the position of the photosensitive surface of the first signal detection unit and the position to be measured on the first surface are conjugate with each other; and/or

The position of the photosensitive surface of the second signal detection unit and the position to be measured on the second surface are conjugate with each other.
The detection system according to claim 21, wherein the system further comprises: one or a combination of the first optical displacement unit and the second optical displacement unit;

The first optical displacement unit is configured to change the imaging position of the position to be measured on the first surface;

The second optical displacement unit is configured to change the imaging position of the position to be measured on the second surface.
The detection system according to claim 23, wherein the first signal detection unit comprises a first signal light collector and a first photodetector, and the first signal light collector is configured to collect the first signal light collector. A signal light, and converge the first signal light to the first photodetector through the first light displacement unit; and/or

The second signal detection unit includes a second signal light collector and a second photodetector, and the second signal light collector is configured to collect the second signal light and cause the second signal light to pass through the The second optical displacement unit converges to the second photodetector.
The detection system according to claim 24, wherein the detection light generating unit is a point light spot generator or a line light spot generator; and when the detection light generating unit is a point light spot generator, the The first photodetector and the second photodetector are optical power meters; when the detection light generating unit is a line spot generator, the first photodetector and the second photodetector are线Detector.
The detection system according to claim 23, wherein:

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; and/or

The second optical displacement unit is configured to adjust the amount of change in the imaging position of the position to be measured on the second surface.
The detection system according to claim 23, wherein the first light displacement unit is configured to increase the relative distance between the first surface and the second surface; and/or the second light The displacement unit is configured to increase the relative distance between the first surface and the second surface.
The detection system according to claim 23, wherein the first optical displacement unit and/or the second optical displacement unit comprise a single prism or a double wedge prism, and the double wedge prism comprises a hypotenuse arranged in parallel. The first wedge prism and the second wedge prism.
The detection system according to claim 28, wherein the relative distance between the first wedge prism and the second wedge prism is adjustable.
The detection system according to claim 21, wherein the wavelengths of the first detection light and the second detection light are the same or different.
The detection system according to claim 23, wherein the first light displacement unit comprises a first light displacement film bearing unit and a plurality of light displacement films located in the first light displacement film bearing unit, and the The amount of change of the propagation direction of the first signal light by a plurality of optical displacement sheets is different, and the optical displacement sheet carrying unit is configured to allow different optical displacement sheets to enter the optical path;

The second optical displacement unit includes a second optical displacement sheet carrying unit and a plurality of optical displacement sheets located in the second optical displacement sheet carrying unit, and the plurality of optical displacement sheets are related to the propagation direction of the second signal light. The amount of change is different, and the light displacement sheet bearing unit is configured to allow different light displacement sheets to enter the optical path.
The detection system according to claim 31, wherein the first light displacement film carrying unit further has a first light through hole, and the first light displacement unit is used to make the first light through hole enter the light path ；

The second light displacement sheet carrying unit further has a second light through hole, and the second light displacement unit is used to allow the second light through hole to enter the light path.
The detection system according to claim 21, wherein the first detection information includes the light intensity of the first signal light, and the second detection information includes the light intensity of the second signal light;

The surface defect information of the test object includes one or more of the following information: whether the test object has a surface defect, the location of the surface defect in the presence of the surface defect, and the surface defect the size of.
The detection system according to claim 21, further comprising:

A carrying platform for carrying the object to be measured, and comprising a carrying surface for placing the object to be measured;

The moving device is used to move at least two of the first signal detection unit, the second signal detection unit, and the carrier, wherein the first signal detection unit is moved in a first direction so that all The second signal detection unit moves in a second direction, so that the bearing platform moves in a third direction. The first direction, the second direction, and the third direction are all clamped between the bearing surface. The angle is greater than zero.
A detection method based on the detection system of claims 21-34, wherein the method comprises:

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;

Collecting the first signal light by the first signal detection unit, and generating first detection information according to the first signal light; and

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 method according to claim 35, wherein the method further comprises:

Before collecting the first signal light, the method includes: making the first light displacement unit change the imaging position of the position to be measured on the first surface; and/or

Before collecting the second signal light, the method includes: making the second light displacement unit change the imaging position of the position to be measured on the second surface.
The detection method according to claim 36, wherein the first optical displacement unit and/or the second optical displacement unit are double-wedge prisms, and the double-wedge prisms include a first wedge with hypotenuses arranged in parallel. The prism and the second wedge prism, wherein the relative distance between the first wedge prism and the second wedge prism is adjustable.
The detection method according to claim 35, wherein:

Simultaneously emitting the first detection light and the second detection light to the object to be measured through the detection light generating unit;

At the same time, the first signal light and the second signal light are collected correspondingly by the first signal detection unit and the second signal detection unit.