Detection System and Method

Abstract

This invention discloses a detection system and method. The detection system includes: a detection component configured to generate a detection spot based on a detection beam, the detection spot including a detection region, the detection region being linear; a signal collection component configured to collect signal light formed by the scattering of the detection spot by the object under test, thereby generating detection information corresponding to the detection spot; and a processor component configured to determine defect feature information on the object under test based on the detection information acquired by the detection region. By adopting the technical solution of this invention, wafer movement time is saved, and detection speed and accuracy are significantly increased.

Description

Technical Field

[0001] This invention belongs to the field of wafer inspection, and particularly relates to a system and method for inspection. Background Technology

[0002] Inspection refers to detecting the presence and location of defects such as grooves, particles, and scratches in a wafer. Inspection has a wide range of applications: on the one hand, as the substrate for chips, defects on wafers can cause expensive manufacturing processes to fail. Wafer manufacturers frequently conduct defect inspections to ensure product yield, and wafer users also need to ensure the cleanliness of the wafers before use to guarantee product yield. On the other hand, semiconductor processing requires very strict control over additional contamination during the process, and directly monitoring this contamination is difficult. Therefore, the degree of additional contamination is often determined by comparing defects before and after wafer processing. Consequently, various inspection methods have been explored.

[0003] Currently, commonly used inspection methods mainly fall into two categories: electron beam inspection and optical inspection. Benefiting from the extreme wavelengths of electron waves, electron beam inspection can directly image components with a resolution of 1 to 2 nanometers. However, it requires a long inspection time and a high-vacuum environment, and is typically used for sampling inspection of a few critical circuit components. Optical inspection is a general term for methods that utilize the interaction between light and the chip to achieve detection. Its basic principle is to determine the presence and size of defects by scanning and detecting the presence and intensity of incident light and defect-scattered light. Summary of the Invention

[0004] This invention addresses the shortcomings of current optical measurement methods, such as long processing time and low accuracy, by proposing a system and method capable of performing multi-incident angle detection on wafers.

[0005] First, the present invention proposes a detection system comprising: a detection component configured to generate a detection spot based on a detection beam; a signal collection component configured to linearly collect signal light formed by the object under test under the action of the detection spot, thereby generating detection information corresponding to the detection spot; and a processor component configured to determine defect feature information on the object under test based on the detection information.

[0006] The present invention also proposes a detection method, comprising: generating a detection spot based on a detection beam, the detection spot including a detection area, the detection area being linear; collecting signal light formed by the scattering of the detection spot by the object under test, thereby generating detection information corresponding to the detection spot; and determining the defect feature information of the object under test based on the detection information formed by the detection area.

[0007] By employing the technical solution of this invention, the area scanned each time can be increased, saving wafer movement time and significantly increasing detection speed. Furthermore, simultaneous bright and dark field detection of the analyte can be performed, further improving efficiency. Using the technical solution of this invention, different particles can be detected using the same wavelength light source. Attached Figure Description

[0008] Embodiments are illustrated and explained with reference to the accompanying drawings. These drawings are used to illustrate the basic principles and thus only show aspects necessary for understanding the basic principles. These drawings are not to scale. In the drawings, the same reference numerals denote similar features.

[0009] Figure 1 This is a diagram illustrating the architecture of a detection system according to an embodiment of the present invention.

[0010] Figure 2a This is an optical architecture diagram of a detection system according to an embodiment of the present invention;

[0011] Figure 2b This is a schematic diagram illustrating the imaging-based collection principle according to an embodiment of the present invention;

[0012] Figure 3 This is a schematic diagram of the scanning trajectory according to an embodiment of the present invention;

[0013] Figure 4 This is a diagram of a detection system architecture according to another embodiment of the present invention. Detailed Implementation

[0014] In the following detailed description of preferred embodiments, reference will be made to the accompanying drawings, which form part of this invention. The accompanying drawings illustrate specific embodiments by way of example that enable the implementation of the invention. The exemplary embodiments are not intended to be exhaustive of all embodiments according to the invention. It will be understood that other embodiments may be utilized, and structural or logical modifications may be made, without departing from the scope of the invention. Therefore, the following detailed description is not restrictive, and the scope of the invention is defined by the appended claims.

[0015] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0016] First, the terminology used in this invention will be explained. The detection beam refers to the light beam generated by the light source assembly that ultimately forms the detection spot. The angle of incidence refers to the angle between the detection beam and the normal direction of the surface of the object under test (e.g., a wafer). The detection area is the illuminated area corresponding to the signal light received by the detector; for example, the portion of the detection spot illuminated by relatively strong light, which is received by the detector for analysis of the object under test.

[0017] Through extensive research, the inventors discovered that in the process of inspecting wafers using light scattering methods, if a point light source (i.e., converging the detection spot to the smallest possible size, with a spot diameter on the order of tens to hundreds of micrometers) is used for point scanning inspection, only a point area can be detected at a time. Therefore, to improve the wafer inspection speed, it is often necessary to increase the wafer's rotational speed and improve the sampling rate of the photodetector. However, the movement trajectory of the motorized rotary platform carrying the wafer needs to be precisely controlled, and its rotational speed is often limited.

[0018] Furthermore, existing dark-field detection methods typically utilize easily manufactured reflectors to collect scattered light. The signal collected by the reflector includes scattered light from the wafer as well as noise from the wafer surface. Based on the principle of the reflector, it is designed to collect as much scattered light as possible; therefore, the signal collected by the reflector contains a significant amount of noise.

[0019] Furthermore, because the spot size is relatively small, the areas illuminated by the spot need to overlap during detection, or the actual detection areas will partially overlap. This results in the same area being illuminated twice by the spot, and correspondingly, the signal light in that area will be collected twice, making the signal processing method very complicated.

[0020] Because the way the reflector collects scattered light makes it difficult to converge scattered light from different points to different points, existing detection methods can only use point scanning for detection.

[0021] To address the aforementioned problems, this invention proposes a line scanning scheme for detection. Compared to point scanning, this increases the area detected each time. Line scanning detects a line region at the same time, which can significantly improve detection speed and reduce instrument costs.

[0022] Depending on the incident light angle (e.g., normal or oblique incidence, and the corresponding oblique incidence angle) and the range of signal light collection angles (normal or non-oblique collection), there are multiple ways to implement light scattering, including: (1) normal collection under normal incidence illumination; (2) non-oblique collection under normal incidence illumination; (3) normal collection under oblique incidence illumination; and (4) non-oblique collection under oblique incidence illumination.

[0023] Furthermore, depending on the incident light angle and the type of defect, the scattered light will exhibit different distribution characteristics. Specifically, for bump-like defects (e.g., particles) distributed on the wafer, when light is incident perpendicularly, the scattered light is relatively evenly distributed in the normal and non-normal collection channels. For pit-like defects, when light is incident perpendicularly, the scattered light is mainly distributed in the normal collection channel, while the scattered light collected in the non-normal collection channel is relatively weak. Similarly, for bump-like defects, when light is incident obliquely, the scattered light is mainly distributed in the non-normal collection channel; for pit-like defects, when light is incident obliquely, the scattered light collected in the non-normal collection channel is weaker. Understandably, for oblique incidence, the distribution of scattered light will change accordingly when the incident angle changes. Understandably, the collection channel corresponds to the exit angle of the scattered light.

[0024] As shown above, oblique incidence has higher detection sensitivity for protruding defects, while normal incidence has higher detection sensitivity for pitting defects. Therefore, defect type analysis can be performed based on the detection method and the corresponding signal distribution.

[0025] Figure 1 This is a diagram illustrating the architecture of a detection system according to an embodiment of the present invention.

[0026] As shown in the figure, the detection system includes a light source assembly 101, a detection assembly 102, a signal collection assembly 103, and a processor assembly 104. The light source assembly 101 provides the detection beam through a light generator (such as one or more lasers).

[0027] The detection component 102 is used to generate a detection spot corresponding to a specified incident angle based on the received detection beam. In one embodiment, the detection component 102 can generate multiple detection spots. When the wafer is being inspected (i.e., the detection spot illuminates the wafer), the wafer will generate corresponding signal light under the action of the detection spot (e.g., through scattering or reflection). It is understood that when the detection spot illuminates a defect, the generated signal light will vary depending on the type of defect or other parameters. The detection component 102 also includes a stage for carrying the wafer, which moves under the control of the processor component 104, thereby moving the wafer along a specified trajectory, adjusting the relative position of the wafer and the detection spot, and realizing scanning inspection.

[0028] The signal collection component 103 includes a detection branch corresponding to a collection channel for multiple scattered light, which can collect the signal light generated by the line detection spot at different angles, thereby generating corresponding detection information.

[0029] The processor component 104 determines defect feature information on the wafer, such as the type, location, and other parameters of the defect, based on the detection information from the signal collection component 103.

[0030] Figure 2a This is an optical architecture diagram of a detection system according to an embodiment of the present invention.

[0031] As shown in the figure, the light source 201 generates a detection beam, which passes through the shaping mirror group 2021 in the detection assembly and reaches the wafer surface, forming a linear detection spot. Understandably, the width and length of this linear detection spot can be controlled by the shaping mirror group 2021.

[0032] In one embodiment, the detection component further includes a polarizer 2022 (e.g., a quarter-wave plate or a half-wave plate) to change the polarization state of the detection beam. For example, different polarization states can be achieved for different detection beams as needed, such as p-light, s-light, circularly polarized light, etc.

[0033] When the detection light spot illuminates the wafer surface, most of the incident light will be reflected off the other side at the same angle as the incident light. However, if a defect exists at the illumination location, the defect will cause some light to be scattered upwards at various angles. Therefore, by setting multiple scattered light collection channels at different locations to detect the intensity of scattered light at different angles, defect information at the location of the linear detection light spot can be determined. Understandably, collecting signal light through multiple signal collection channels can improve detection accuracy.

[0034] In this embodiment, the signal light collection channels are divided into a normal collection channel P1 and non-normal collection channels P2 and P3 according to the collection angle range. The collection angle range corresponding to the normal collection channel P1 is 0° to 20°, and the collection angle range corresponding to the non-normal collection channels P2 and P3 is 20° to 90°. For example, the collection angle range corresponding to the non-normal collection channel P2 is 35±10°, and the collection angle range corresponding to the non-normal collection channel P3 is 55±10°. In this embodiment, the detection branch corresponding to each collection channel includes a detection lens group and a detector to achieve imaging collection of the signal light. When a line detector is used, the detection area is linear. In one embodiment, the center of the detection area coincides with the center of the detection spot, and the length of the detection area is less than the length of the detection spot. In practical applications, the light intensity at the center of the detection spot is strong, while the light intensity at both ends is weak. The signal light at both ends is easily submerged by noise. Therefore, setting the length of the detection area to be less than the length of the detection spot can improve the detection accuracy.

[0035] Figure 2b This is a schematic diagram of the imaging collection principle according to an embodiment of the present invention.

[0036] As shown in the figure, the detection beam illuminates the wafer surface, forming a detection spot. When a defect exists at location A, the scattered light generated by the defect under the action of the detection spot propagates in various directions above the wafer. In this embodiment, multiple collection channels are set in the normal and non-normal directions, and each collection channel collects scattered light spatially distributed around a scattering angle.

[0037] The defect at location A emits scattered light within a specific angular range, which is projected onto a designated location of detector TCa via detector lens group 21. Similarly, when a defect exists at location B, the scattered light generated by the defect under the action of detection spot B is projected onto a designated location of detector TCb via detector lens group 22. The scattered light from the defect at location A is projected onto a location next to detector TCb via detector lens group 22, and similarly, the scattered light from the defect at location B is projected onto a location next to detector TCa via detector lens group 21. Therefore, detectors TCa and TCb independently collect the scattered light generated by defects at locations A and B, respectively, without interfering with each other.

[0038] By making each collection channel independent, when it is necessary to collect normally incident and oblique incident light spots in the normal and non-normal directions respectively, multi-channel collection of signal light can be achieved.

[0039] Please refer to the following: Figure 2a The signal collection component includes a first to a third detection branch. The first detection branch includes a line detector TC1 and a first detection lens group TJ1 to collect the signal light generated by the wafer on the normal collection channel P1 under the action of the detection spot. The second detection branch includes a line detector TC2 and a second detection lens group TJ2 to collect the signal light generated by the wafer on the non-direction collection channel P2 under the action of the detection spot. The third detection branch includes a line detector TC3 and a third detection lens group TJ to collect the signal light generated by the wafer on the non-direction collection channel P3 under the action of the detection spot.

[0040] In one implementation, the detection region corresponding to each detection spot (i.e., the portion received by the line detector) can be set to the part of each detection spot with the strongest light intensity (linear). In other words, the detector can collect signal light linearly. The center of the detection region coincides with the center of the detection spot, and the length of the detection region is less than or equal to the length of the detection spot.

[0041] In one embodiment, the detection spot is linear, and the length of the detection area is 90%-95% of the length of the detection spot. In another embodiment, the length of the detection spot is 5 mm to 10 mm, and the width is 5 μm to 100 μm.

[0042] Although Figure 2aThe diagram shows three probe branches, but in other embodiments, other numbers of probe branches can be set according to the defect characteristics of the wafer, wherein each probe branch corresponds to an incident angle different from the other probe branches.

[0043] As shown above, through imaging-based collection, the signal light corresponding to each point in the detection area can be converged to a designated position on the line detector after passing through the detection lens group. Thus, the collected light at each point on the line detector is independent and directly related to the scattered light at the detection spot position. In this way, through the detection lens group and the line detector, the relatively strong light intensity portion of the illuminated area can be obtained, serving as the linear detection area.

[0044] Figure 3 This is a schematic diagram of the scanning trajectory according to an embodiment of the present invention.

[0045] As shown in the figure, the detection spot extends radially along the wafer, thus allowing scanning from the outer circle to the inner circle in a concentric circle manner.

[0046] In the initial detection state, the detection spot is positioned at the outermost edge of the wafer by moving the equipment. Understandably, this embodiment detects the entire wafer; if the area to be tested is part of the wafer, the detection spot needs to be moved to the outermost edge of that area. Then, the equipment rotates the wafer, and the signal collection component simultaneously collects both normal and non-normal signals scattered from the wafer. After completing one revolution along the first concentric circle, the equipment moves the wafer, causing the detection spot to move a distance d in the first radial direction (i.e., the distance d between the centers of adjacent concentric circles) for the next scan. This process continues until the detection along the Nth concentric circle is completed (at which point the spot illuminates the center of the wafer), thus completing the wafer scan and acquiring a set of detection information corresponding to the detection spot. Understandably, each revolution completes the scan of a ring-shaped area. In one embodiment, the moving distance d is greater than or equal to 80% of the detection spot length and less than or equal to the detection spot length.

[0047] In this embodiment, the detection area of ​​the detection spot extends radially, and the scanning direction of the detection spot is perpendicular to the extension direction of the detection spot. It will be understood that, in another embodiment, the angle between the scanning direction of the detection spot and the extension direction of the detection spot is greater than 0 and less than 90°.

[0048] Although the above embodiments involve inspection from the outer edge to the inner edge of the wafer, it is understood that in another embodiment, scanning can also be performed from the inner edge to the outer edge. Furthermore, the detection spot can extend radially along the wafer or in other directions. The wafer scanning path can also be spiral, Z-shaped, S-shaped, rectangular, etc. For example, when using a spiral trajectory scanning method, the scanning platform rotates while slowly translating in one direction to complete the scanning of the entire area.

[0049] Therefore, multiple detection spots can be set to detect the wafer when the detection areas do not overlap. These multiple detection spots may partially overlap or not overlap.

[0050] As mentioned above, for pit-type defects, normal incidence achieves better detection accuracy, while oblique incidence enables high-precision detection of protrusion-type defects. Therefore, the detection system can employ not only separate vertical and oblique incidence light, but also a scheme that uses both vertical and oblique incidence light for detection. To distinguish between vertical and oblique incidence scattered light, a wavelength-splitting approach can be used, employing light sources of different wavelengths for vertical and oblique incidence detection.

[0051] Figure 4 The following is a system architecture diagram of a detection system according to another embodiment of the present invention. Through this detection system, simultaneous detection of bright field and dark field can be achieved.

[0052] As shown in the figure, the first light source assembly 410 generates a first detection beam, which passes through an aperture 431, a polarizer 432, and a beam splitter 433 to reach the wafer surface, forming a first detection spot S1. The second light source assembly 420 generates a second detection beam, which passes through a shaping mirror assembly 434 to reach the wafer surface, forming a detection spot S2 that at least partially overlaps with the detection spot S1. In one embodiment, the detection spot S2 is a linear spot, which concentrates the light intensity as much as possible in a dark field.

[0053] For bright field detection, the wafer generates reflected light under the action of the first detection spot S1, which sequentially passes through the signal light collector 435 (e.g., a probe lens group or other components with imaging collection function), beam splitter 433, and then to beam splitter 436. In the normal direction, the first filter 437 selectively receives the beam from beam splitter 436, so that the polarization detector 440 receives the reflected light generated based on the first detection spot S1, thereby achieving bright field detection.

[0054] In a dark field, the wafer will generate scattered light in both the normal and non-normal directions under the action of the detection spot S2. The scattered light generated in the normal direction passes sequentially through the signal light collector 435 and the beam splitter 433 to reach the beam splitter 436. The second filter 438 selectively receives the beam from the beam splitter 436, thereby enabling the line detector 441 to receive the normal scattered light based on the second detection spot S2. The scattered light generated in the non-normal direction reaches the line detector 442 through the signal light collector 439.

[0055] Understandably, when it is not necessary to analyze the scattered light generated by the detection spot S2 in the normal direction, the beam splitter 436 can be removed.

[0056] As can be seen from the above, by splitting and selectively receiving the reflected and scattered light in the normal direction, the detection system 400 can realize the optical path for simultaneous detection of bright and dark fields. In this method, bright field detection and dark field detection are simultaneously realized by line scanning detection, and the detection positions are the same at the same time. By using different wavelength light sources for bright and dark fields, independent detection of different schemes is realized.

[0057] While the above description uses the simultaneous generation of detection beams corresponding to two wavelengths and partially overlapping as an example, those skilled in the art will understand that in other embodiments, detection beams corresponding to multiple wavelengths and partially overlapping can also be generated. Only appropriate beam splitters and filters are needed to selectively receive the beams. For example, the detection system 400 may also include a third light source component (not shown), which can generate a third detection beam with a wavelength different from the first and second detection beams, and generate a detection beam S3. By setting appropriate beam splitters and filters, the scattered or reflected light generated by the detection beam S3 can be selectively received.

[0058] This invention proposes a detection method, comprising: generating a detection spot based on a detection beam; linearly collecting the signal light formed by the test object under the action of the detection spot, thereby generating detection information corresponding to the detection spot; and determining the defect feature information of the test object based on the detection information.

[0059] The present invention also proposes a detection method, comprising the following steps: generating a detection spot based on a detection beam, the detection spot including a linear detection area; collecting signal light formed by the scattering of the detection spot by the object under test, thereby generating detection information corresponding to the detection spot; and determining the defect feature information of the object under test based on the detection information formed by the detection area.

[0060] The step of collecting the signal light formed by the scattering of the detection spot by the test object includes: scanning the test area of ​​the test object by moving the detection spot relative to the test object, and collecting the signal light during the scanning process.

[0061] When the area to be measured of the object is circular, the scanning steps include: rotating the object around the center of the area; after rotating the object around the center, translating the object relative to the detection spot along the diameter of the area; repeating the above steps until the detection spot covers the center of the detection area. In this way, rotation and translation are not performed simultaneously, which improves the stability of the system, improves imaging quality, and thus improves detection accuracy.

[0062] In one implementation, a specific step size is equal to or less than the size of the detection area in the translation direction.

[0063] The detection method can also be implemented through the aforementioned detection system. Specifically, the detection component generates a detection spot based on the detection beam, and under the control of the processor component, the signal collection component collects the signal light formed by the object under test after the detection spot is scattered by the object under test, thereby generating detection information corresponding to the detection spot; and the defect feature information of the object under test is determined by the detection information obtained by the processor component based on the detection area.

[0064] Although the above embodiments utilize line spot detection, the detection method of the present invention is also applicable to point spot or area spot detection methods. It is understood that when using point / area spots to inspect wafers, the shaping lens group needs to be adjusted to form the point / area spots. For example, point spots can be used to inspect wafers using a spiral pattern.

[0065] Compared to traditional detection methods, the detection method of this invention uses line scanning, which covers a large area each time and the signal received by the line detector is more uniform. This not only saves wafer movement time but also significantly increases detection speed and accuracy.

[0066] Therefore, although the invention has been described with reference to specific examples, which are intended to be exemplary only and not to limit the invention, it will be apparent to those skilled in the art that changes, additions or deletions may be made to the disclosed embodiments without departing from the spirit and scope of the invention.

Claims

1. A detection system, characterized in that, include: A detection component configured to generate a detection spot based on a detection beam, the detection spot being linear and including a detection region, the detection region being linear; A signal collection component is configured to collect the signal light formed by the detection spot after being scattered by the object under test, and thereby generate detection information corresponding to the detection spot. as well as A processor component configured to determine defect feature information on the object under test based on detection information acquired in the detection area; The signal collection component includes detection branches for multiple signal light collection channels corresponding to different angles. Each detection branch includes a signal light collector and a line detector. The signal light collector is used to project the collected signal light onto the line detector in an imaging manner. The signal light collection channel includes a normal collection channel and multiple non-normal collection channels. For pit-like defects distributed on the test object, when the detection spot is incident normally, the signal light formed after the detection spot is scattered by the test object is mainly distributed in the normal collection channel, and the signal light formed after the detection spot is scattered by the test object and collected in the non-directional collection channel is relatively weak. For protrusion-like defects distributed on the test object, when the detection spot is incident obliquely, the signal light formed after the detection spot is scattered by the test object is mainly distributed in the non-directional collection channel, and the signal light formed after the detection spot is scattered by the test object and collected in the normal collection channel is relatively weak. Based on the corresponding signal distribution, defect type analysis can be performed.

2. The detection system as described in claim 1, characterized in that, The signal collection component includes: The first scattered light detection branch is configured to collect scattered light with a first exit angle; The second scattered light detection branch is configured to collect scattered light with a second exit angle that is not equal to the first exit angle.

3. The detection system as described in claim 1, characterized in that, The detection component is configured as follows: A first detection spot is generated based on a first detection beam, wherein the first detection spot is a linear spot; A second detection spot is generated based on a second detection beam, wherein the first detection spot and the second detection spot partially overlap, and the wavelength of the first detection beam is different from the wavelength of the second detection beam.

4. The detection system as described in claim 2, characterized in that, The first scattered light detection branch includes a first signal light collector and a first line detector, wherein the first signal light collector is used to project the collected signal light onto the first line detector in an image-like manner. The second scattered light detection branch includes a second signal light collector, a first beam splitter, a first filter, and a second line detector. The second signal light collector is used to project the collected signal light onto the second line detector in an image-like manner. The first filter receives the signal light via the first beam splitter and selectively receives the received signal light based on the wavelength.

5. The detection system as described in claim 4, characterized in that, The signal collection component is further configured to collect the signal light formed by the detection spot after reflection by the object under test, and the signal collection component further includes: The third detection branch includes a first filter and a third line detector, wherein the second filter receives the signal light via the first beam splitter and selectively receives the received signal light based on wavelength.

6. The detection system as described in claim 1, characterized in that, The processor component is configured such that the detection component detects the object under test along a specified detection trajectory. The specified detection trajectory is the scanning trajectory of the center of the detection area corresponding to the detection spot relative to the surface of the object being measured, and the specified detection trajectory includes multiple concentric circles arranged radially.

7. The detection system as described in claim 6, characterized in that, The difference in radii between adjacent concentric circles is less than or equal to the size of the detection area along the radial direction of the concentric circles.

8. The detection system as described in claim 4, characterized in that, The first signal light collector and / or the second signal light collector are a detection lens group.

9. The detection system as described in claim 1, characterized in that, The detection area of ​​the detection spot extends radially, and the scanning direction of the detection spot is perpendicular to the extension direction of the detection area, or the angle between the scanning direction of the detection spot and the extension direction of the detection area is an acute angle or an obtuse angle.

10. The detection system as described in claim 1, characterized in that, The extension direction of the detection spot is the same as the extension direction of the detection area.

11. The detection system as described in claim 10, characterized in that, The center of the detection area coincides with the center of the detection spot, and the length of the detection area is less than the length of the detection spot.

12. The detection system as described in claim 1, characterized in that, The length of the detection area is 90%-95% of the length of the detection spot.

13. The detection system as described in claim 1, characterized in that, The length of the detection spot is 5 mm to 10 mm, and the width of the detection spot is 5 μm to 100 μm.

14. A detection method, characterized in that, include: Based on the detection beam, a detection spot is generated. The detection spot is linear and includes a detection area, which is also linear. By collecting signal light from the detection spot scattered by the test object from multiple different angles, detection information corresponding to the detection spot is generated. Based on the detection information formed by the detection area, the defect feature information of the object under test is determined; Specifically, for pit-like defects distributed on the object under test, when the detection spot is incident normally, the signal light formed after the detection spot is scattered by the object under test is mainly distributed in the normal direction, while the signal light formed after the detection spot is scattered by the object under test in the non-normal direction is relatively weak. For protrusion-like defects distributed on the object under test, when the detection spot is incident obliquely, the signal light formed after the detection spot is scattered by the object under test is mainly distributed in the non-normal direction, while the signal light formed after the detection spot is scattered by the object under test in the normal direction is relatively weak. Based on the corresponding signal distribution, defect type analysis can be performed.

15. The detection method as described in claim 14, characterized in that, The steps for collecting the signal light formed by the scattering of the detection spot by the test object include: By moving the detection spot relative to the object being tested, the test area of ​​the object is scanned, and the signal light is collected during the scanning process; The scanning direction is perpendicular to the extension direction of the detection area, or the angle between the scanning direction and the extension direction of the detection area is an acute angle or an obtuse angle.

16. The detection method as described in claim 15, characterized in that, The test area of ​​the object being tested is circular; the scanning steps include: rotating the object being tested around the center of the test area; after rotating the object being tested around the center of the test area, translating the object being tested relative to the detection spot along the diameter direction of the test area by a specific step length; repeating the above steps until the center of the test area is covered by the detection spot.

17. The detection system as described in claim 16, characterized in that, The specific step size is equal to or less than the size of the detection area in the translation direction.

18. The detection system as described in claim 14, characterized in that, The center of the detection area coincides with the center of the detection spot, and the length of the detection area is less than the length of the detection spot.

19. The detection method as described in claim 14, characterized in that, Also includes: Provide a detection system according to any one of claims 1 to 13; The detection component generates a detection spot based on the detection beam. Under the control of the processor component, the signal collection component collects the signal light formed by the object under test after the detection spot is scattered by the object under test, thereby generating detection information corresponding to the detection spot. And the defect feature information of the object under test is determined by the detection information obtained by the processor component based on the detection area.

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