Detection system and detection method

Abstract

The invention provides a detection system and a detection method. The detection system comprises a basic light path, a first scanning light path, a second scanning light path, a detection light path, a first platform, a second platform and a scanning light source, the basic light path comprises a detection light source which is used for emitting a detection light beam; the scanning light source is used for emitting a scanning light beam, and when the detection light path is used for passing through the detection light beam and carrying out defect detection on the ith to-be-detected object at the detection position, the target scanning light path is used for passing through the scanning light beam and carrying out defect scanning on the (i + 1) th to-be-detected object at the target scanning position. The two light sources are arranged, compared with one light source, the light power of the two light sources can be lower, the situation that only one light source with the large light power is arranged, and consequently the detection cost is increased is avoided, and the high detection efficiency and the low detection cost can be both considered.

Description

Technical Field

[0001] The present application relates to the field of defect detection, and in particular to a detection system and a detection method. Background Art

[0002] When performing defect detection on a large number of objects to be tested, such as wafers, it is necessary to be able to quickly and accurately detect whether the surface of the objects to be tested has defects. In addition, multiple tests are often performed on a single object to complete the entire defect detection process, and the optical path design required for each test is also different. When the number of objects to be tested is large, a lot of time is required to perform defect detection. In related technologies, the detection system will only detect the next object to be tested after completing the defect detection of one object to be tested, and the optical path design needs to be repeatedly changed during the detection process of one object to be tested, resulting in extremely low defect detection efficiency. Summary of the Invention

[0003] In view of this, the purpose of this application is to provide a detection system and detection method that can achieve both high detection efficiency and low detection cost. The specific scheme is as follows:

[0004] In one aspect, the present application provides a detection system, comprising a base optical path, a first scanning optical path, a second scanning optical path, a detection optical path, a first platform, a second platform, and a scanning light source;

[0005] The basic optical path includes a detection light source, the detection light source is used to emit a detection beam, the detection beam is used to be incident on the detection optical path; the scanning light source is used to emit a scanning beam, the scanning beam is used to be incident on the first scanning optical path or the second scanning optical path;

[0006] The first platform and the second platform are both used to carry the object to be tested, the first platform switches between a first scanning position and a detection position, and the second platform switches between a second scanning position and the detection position; the first scanning position and the second scanning position are respectively located on the light exit side of the first scanning light path and the second scanning light path, and the detection position is located on the light exit side of the detection light path;

[0007] While the detection optical path is used to perform defect detection on the i-th object to be tested at the detection position through the detection light beam, the target scanning optical path is used to perform defect scanning on the i+1-th object to be tested at the target scanning position through the scanning light beam; the target scanning optical path is the first scanning optical path or the second scanning optical path, and the target scanning position is the first scanning position or the second scanning position; i≥1.

[0008] Optionally, the basic optical path further includes a first light splitting module;

[0009] The first light splitting module is used to split the light beam emitted by the detection light source into the detection light beam and the redundant light beam transmitted in different directions, and to adjust the optical power of the detection light beam.

[0010] Optionally, the basic optical path further includes a light absorbing module located on a side of the first light splitting module from which the redundant light beam is emitted, and the light absorbing module is configured to absorb the redundant light beam.

[0011] Optionally, the first light splitting module includes a second half-wave plate and a second polarization beam splitting prism.

[0012] Optionally, the scanning light source includes a first scanning light source and a second scanning light source, the first sub-scanning beam emitted by the first scanning light source is used to be incident on the first scanning light path, and the second sub-scanning beam emitted by the second scanning light source is used to be incident on the second scanning light path.

[0013] Optionally, the first scanning optical path includes a first switch, and the first switch is used to control whether the first sub-scanning beam can be incident on the first scanning optical path;

[0014] The second scanning optical path includes a second switch, and the second switch is used to control whether the second sub-scanning light beam can be incident on the second scanning optical path.

[0015] Optionally, the detection system further includes a switching module;

[0016] The switching module is used to switch the scanning light beam between the first scanning light path and the second scanning light path.

[0017] Optionally, the optical power of the detection light source is greater than the optical power of the scanning light source.

[0018] Optionally, the first scanning optical path, the second scanning optical path or the detection optical path includes a shaping module, and the shaping module is used to perform beam shaping processing.

[0019] Optionally, the first scanning optical path, the second scanning optical path or the detection optical path includes a polarization module, and the polarization module is used to adjust the polarization state of the light beam.

[0020] Optionally, the detection optical path further includes a third switch;

[0021] When the third switch is in an on state, the third switch is used to enable the detection light beam to perform defect detection on a target defect belonging to a second defect category on the surface of the object to be detected;

[0022] When the third switch is in the off state, the third switch is used to prevent the detection light beam from performing defect detection on target defects belonging to the first defect category on the surface of the object to be tested; in the defect scanning result obtained by completing the defect scan on the i-th object to be tested, the minimum value of the first light intensity range corresponding to the first defect category is greater than the maximum value of the second light intensity range corresponding to the second defect category.

[0023] In another aspect, an embodiment of the present application further provides a detection method, characterized in that it is applied to a detection system, and the method includes:

[0024] The i-th object to be tested is moved from an initial scanning position to the detection position, and the detection light source is turned on; the initial scanning position is the first scanning position or the second scanning position, and the i-th object to be tested has completed defect scanning by the scanning light beam at the initial scanning position;

[0025] The (i+1)th object to be tested is located at the target scanning position; the target scanning position is different from the initial scanning position;

[0026] Turning on the scanning light source and making the scanning light beam incident on the target scanning light path corresponding to the target scanning position;

[0027] While performing defect detection on the i-th object to be tested using the detection light beam based on the detection light path, performing defect scanning on the (i+1)-th object to be tested using the scanning light beam based on the target scanning light path.

[0028] Optionally, the scanning light source includes a first scanning light source and a second scanning light source, and turning on the scanning light source and making the scanning light beam incident on the target scanning light path corresponding to the target scanning position includes:

[0029] When the target scanning position is the first scanning position and the target scanning optical path is the first scanning optical path, turning on the first scanning light source so that the first sub-scanning light beam emitted by the first scanning light source is incident on the first scanning optical path corresponding to the first scanning position;

[0030] When the target scanning position is the second scanning position and the target scanning optical path is the second scanning optical path, the second scanning light source is turned on so that the second sub-scanning beam emitted by the second scanning light source is incident on the second scanning optical path corresponding to the second scanning position.

[0031] Optionally, the detection system further includes a switching module; turning on the scanning light source and causing the scanning light beam to be incident on the target scanning light path corresponding to the target scanning position includes:

[0032] The scanning light source is turned on, and the scanning light beam is made incident on the target scanning light path corresponding to the target scanning position through the switching module.

[0033] Optionally, the basic optical path further includes a first light splitting module; and before performing defect detection on the i-th object to be tested by the detection light beam based on the detection optical path, the method further includes:

[0034] Determining a first optical power adapted to the i-th object under test;

[0035] The first light splitting module enables the detection light beam incident on the detection light path to reach the first optical power.

[0036] Optionally, the method further includes:

[0037] After completing defect detection on the i-th object to be tested, moving the i-th object to be tested from the testing position to the initial scanning position;

[0038] At the initial scanning position, the i-th object to be tested is replaced by the i+2-th object to be tested.

[0039] Optionally, the method further includes:

[0040] After completing defect detection on the i-th object to be tested and obtaining a defect detection result, the defect detection result and the defect scanning result obtained by completing defect scanning on the i-th object to be tested are fused to obtain a target detection result of the i-th object to be tested; the target detection result is used to identify the defect information of the i-th object to be tested.

[0041] Optionally, the defect scanning result obtained by completing the defect scanning on the i-th object to be tested includes the defect position of each defect on the surface of the i-th object to be tested and the light intensity of each defect;

[0042] Before performing defect detection on the i-th object to be tested by using the detection light beam based on the detection light path, the method further includes:

[0043] Determining the defect category to which each defect belongs based on the light intensity; different defect categories correspond to different light intensity ranges;

[0044] The performing defect detection on the i-th object to be tested by using the detection light beam based on the detection light path includes:

[0045] Perform defect detection on each position of the surface of the i-th object to be detected by traversing the detection light beam based on the detection light path;

[0046] When defect detection is performed on a target defect located at a target defect position, the target defect is detected by the detection light beam having a target optical power; the target optical power is determined based on the defect category to which the target defect belongs.

[0047] Optionally, the optical power of the scanning beam is less than the optical power of the detection beam; when the defect category to which the target defect belongs is a first defect category, the target optical power is a first value; when the defect category to which the target defect belongs is a second defect category, the target optical power is a second value;

[0048] The minimum value of the first light intensity range corresponding to the first defect category is greater than the maximum value of the second light intensity range corresponding to the second defect category; and the first value is smaller than the second value.

[0049] Optionally, the detection optical path further includes a third switch; and the performing defect detection on the target defect using the detection light beam having the target optical power includes:

[0050] When the target defect belongs to the second defect category, controlling the third switch to be in an open state, and the detection light beam passes through the third switch to perform defect detection on the target defect;

[0051] When the target defect belongs to the first defect category, the third switch is controlled to be in an off state, the detection light beam is blocked by the third switch, and defect detection is not performed on the target defect.

[0052] An embodiment of the present application provides a detection system and a detection method, wherein the detection system includes a basic optical path, a first scanning optical path, a second scanning optical path, a detection optical path, a first platform, a second platform, and a scanning light source; the basic optical path includes a detection light source, the detection light source is used to emit a detection beam, and the detection beam is used to be incident on the detection optical path; the scanning light source is used to emit a scanning beam, and the scanning beam is used to be incident on the first scanning optical path or the second scanning optical path; the first platform and the second platform are both used to carry the object to be tested, the first platform switches between a first scanning position and a detection position, and the second platform switches between a second scanning position and a detection position; the first scanning position and the second scanning position are respectively located on the light exit sides of the first scanning optical path and the second scanning optical path, and the detection position is located on the light exit side of the detection optical path; while the detection optical path is used to pass the detection beam to perform defect detection on the i-th object to be tested at the detection position, the target scanning optical path is used to pass the scanning beam to perform defect scanning on the i+1-th object to be tested at the target scanning position; the target scanning optical path is the first scanning optical path or the second scanning optical path, and the target scanning position is the first scanning position or the second scanning position; i≥1.

[0053] In an embodiment of the present application, by setting the defect detection process of the i-th object to be tested and the defect scanning process of the next object to be tested simultaneously, it is possible to ensure that both platforms (the first platform and the second platform) can carry the object to be tested for processing, and there will be no idle platform situation. The simultaneous processing of the two objects to be tested greatly improves the detection efficiency. In addition, the present application cooperates with the two platforms by setting three positions (the first scanning position, the second scanning position and the detection position). The first platform can be moved to the first scanning position that will not be occupied by the second platform, so that the first platform and the second platform can start moving at the same time, greatly improving the platform movement efficiency and making the flow of the object to be tested more convenient. In addition, since the light beam power required for defect detection and defect scanning is different, by setting two light sources, namely the scanning light source and the detection light source, there is no need to adjust the light power of the light source during the entire detection process, saving time, without using a switching module, and the power control is more stable. And compared to setting one light source, setting two light sources can have a smaller light power than setting one light source, avoiding the increase in detection cost by setting only one light source with a larger light power, and can take into account both higher detection efficiency and lower detection cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0055] Figure 1 A schematic diagram of a detection system provided in an embodiment of the present application is shown;

[0056] Figure 2 A schematic diagram of the layout of a scanning position and a detection position provided in an embodiment of the present application is shown;

[0057] Figure 3 A schematic diagram of a polarization module provided in an embodiment of the present application is shown;

[0058] Figure 4 A schematic diagram of another detection system provided in an embodiment of the present application is shown;

[0059] Figure 5 A schematic diagram of a detection method provided in an embodiment of the present application is shown;

[0060] Figure 6 A schematic diagram of another detection system provided in an embodiment of the present application is shown;

[0061] Figure 7A schematic diagram showing a layout of another scanning position and detection position provided in an embodiment of the present application is shown;

[0062] Figure 8 A schematic diagram of another detection system provided in an embodiment of the present application is shown;

[0063] Figure 9 A schematic diagram showing a layout of another scanning position and detection position provided in an embodiment of the present application is shown;

[0064] Figure 10 A schematic diagram of a motion platform provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0065] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below with reference to the accompanying drawings.

[0066] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0067] For ease of understanding, a detection system and a detection method provided in an embodiment of the present application are described in detail below with reference to the accompanying drawings.

[0068] refer to Figure 1 , which is a schematic diagram of a detection system provided in an embodiment of the present application, the detection system includes a basic optical path 100, a first scanning optical path 101, a second scanning optical path 102, a detection optical path 103, a first platform 13, a second platform 19 and a scanning light source.

[0069] The basic optical path 100 may include a detection light source 1, which is used to emit a detection light beam, and the detection light beam is used to be incident on the detection light path 103, that is, the detection light source 1 is mainly used to provide a detection light beam for illuminating the detection light path 103. The detection light source 1 may be, for example, a laser, specifically a deep ultraviolet high-power laser. The deep ultraviolet high-power laser can emit a continuous or quasi-continuous deep ultraviolet laser beam. In order to reduce the difficulty of debugging the subsequent optical path, the detection light source 1 itself can achieve six-degree-of-freedom adjustment. In addition, in order to reduce the impact of subsequent mechanical motion structure impact on the detection light source 1, a vibration isolation pad may be added between the detection light source 1 and the supporting structure of the detection light source 1 to ensure that the position of the detection light source 1 does not change significantly.

[0070] The scanning light source is used to emit a scanning beam. The scanning light source can also be a laser, for example. The scanning light source and the detection light source 1 are two independent light sources and can be the same or different. The scanning beam is used to be incident on the first scanning optical path 101 or the second scanning optical path 102. In other words, the scanning beam emitted by the scanning light source can propagate in the first scanning optical path 101 or the second scanning optical path 102.

[0071] Since the scanning optical path requires a scanning beam with an optical power of X watts for defect scanning, and the detection optical path 103 requires a detection beam with an optical power of Y watts for defect detection, if only the same light source is used, the maximum optical power of the light source must reach (X + Y) watts to achieve both defect detection and defect scanning. As the optical power increases, the manufacturing difficulty of the light source increases rapidly, and the price also rises rapidly. Therefore, a light source can be provided separately for the scanning optical path and the detection optical path 103. By providing two light sources, the optical power requirements of the light source are reduced, thereby reducing the cost of the optical path.

[0072] The scanning beam is primarily used for defect scanning, while the detection beam is primarily used for defect detection. Generally, defect scanning is performed before defect detection. The first scanning optical path 101 and the second scanning optical path 102 can be understood as two different scanning optical paths. The optical elements in these paths can be the same or different. The primary difference between the first scanning optical path 101 and the second scanning optical path 102 lies in the different locations of the optical paths.

[0073] The first platform 13 and the second platform 19 are both used to carry the object under test 107. The first platform 13 and the second platform 19 are both platforms with a carrying function, such as a loading table, etc. The object under test 107 is an object that needs to be inspected for defects, such as a semiconductor structure, a wafer, etc.

[0074] The surface of the object to be tested 107 usually has various defects, such as particles, area defects, slipline defects, cluster defects, scratches, etc. The defects may be large-sized defects or small-sized defects. In order to detect smaller defects and improve the detection accuracy, the scattering-based detection needs to increase the laser power of the illumination light. However, high-power illumination will cause large-sized defects to be swept out due to heating, aggravating the contamination of the object to be tested. In order to identify the defects in the object to be tested 107 as comprehensively as possible, the object to be tested 107 can be first defect-scanned and then defect-detected. Defect scanning mainly uses a scanning light beam with a smaller optical power to identify large-sized defects, so as to avoid the situation where defects are swept out due to excessive optical power, such as large particle defects being swept out, thereby contaminating the object to be tested. During defect detection, small-sized defects are mainly identified using a detection light beam with a larger optical power. In this way, all defects in the object to be tested 107 are identified through the two steps of defect scanning and defect detection.

[0075] The first scanning position 104 can be understood as a position for defect scanning, and the first platform 13 can be placed at the first scanning position 104 . The second scanning position 105 can be understood as another position for defect scanning, and the second platform 19 can be placed at the second scanning position 105 .

[0076] The first scanning position 104 and the second scanning position 105 are located on the light exit side of the first scanning optical path 101 and the second scanning optical path 102, respectively. Specifically, the first scanning position 104 is located on the light exit side of the first scanning optical path 101. When the first platform 13 is located at the first scanning position 104, the scanning beam propagating in the first scanning optical path 101 can scan the object under test 107 on the first platform 13 for defects. The second scanning position 105 can be located on the light exit side of the second scanning optical path 102. When the second platform 19 is located at the second scanning position 105, the scanning beam propagating in the second scanning optical path 102 can scan the object under test 107 on the second platform 19 for defects.

[0077] The detection position 106 can be understood as the position for defect detection. The detection position 106 is located on the light-emitting side of the detection light path 103. The first platform 13 and the second platform 19 can both be located at the position of the detection position 106 so as to use the detection light beam propagating in the detection light path 103 to perform defect detection on the object to be tested 107 on the platform.

[0078] The first platform 13 can be switched between the first scanning position 104 and the inspection position 106, and the second platform 19 can be switched between the second scanning position 105 and the inspection position 106. In other words, the position of the first platform 13 is movable, and the first platform 13 can move between the first scanning position 104 and the inspection position 106. When the first platform 13 moves to the first scanning position 104, the first scanning optical path 101 can scan the object under test 107 on the first platform 13 for defects. When the first platform 13 moves to the inspection position 106, the inspection optical path 103 can detect defects on the object under test 107. Similarly, the position of the second platform 19 is also movable, and the second platform 19 can move between the second scanning position 105 and the inspection position 106. When the second platform 19 moves to the second scanning position 105, the second scanning optical path 102 can scan the object under test 107 on the second platform 19 for defects. When the second platform 19 moves to the inspection position 106, the inspection optical path 103 can detect defects on the object under test 107.

[0079] refer to Figure 2 As shown, it is a schematic diagram of the layout of a scanning position and a detection position 106 provided in an embodiment of the present application. The first platform 13 can move between the first scanning position 104 and the detection position 106, and the second platform 19 can move between the second scanning position 105 and the detection position 106. At this time, the object to be tested 107 is placed on the first platform 13, and the first platform 13 is located at the first scanning position 104. The object to be tested 107 is not placed on the second platform 19, and the second platform 19 is located at the second scanning position 105.

[0080] Because defect scanning and defect detection for a large number of DUTs 107 are inefficient in related art, to improve detection efficiency, simultaneous related processing can be performed on two DUTs 107. Specifically, while the detection optical path 103 is used to perform defect detection on the i-th DUT 107 at the detection position 106 through a detection beam, the target scanning optical path is used to perform defect scanning on the i+1-th DUT 107 at the target scanning position through a scanning beam, where i ≥ 1.

[0081] Specifically, the i-th object under test 107 and the i+1-th object under test 107 can be processed simultaneously. These two objects under test 107 can be placed arbitrarily on the two platforms. For example, the i-th object under test 107 can be placed on the second platform 19, and the i+1-th object under test 107 can be placed on the first platform 13. Of course, they can also be interoperable. Taking the i-th object under test 107 placed on the first platform 13 and the i+1-th object under test 107 placed on the second platform 19 as an example, when defect detection is performed on the i-th object under test 107, the first platform 13 is located at the detection position 106. The detection beam passes through the detection optical path 103 and is incident on the first platform 13. Defect detection is performed on the i-th object under test 107 on the first platform 13. Defect detection can be performed using either bright field detection or dark field detection.

[0082] At this point, the idle target scanning optical path can be utilized to improve detection efficiency. The target scanning optical path can be the first scanning optical path 101 or the second scanning optical path 102, and the target scanning position can be the first scanning position 104 or the second scanning position 105. In short, when the i-th object to be tested 107 is placed on the second platform 19, since the second platform 19 is located at the second scanning position 105, the target scanning optical path is the first scanning optical path 101, and the target scanning position is the first scanning position 104. When the i-th object to be tested 107 is placed on the first platform 13, since the first platform 13 is located at the first scanning position 104, the target scanning optical path is the second scanning optical path 102, and the target scanning position is the second scanning position 105.

[0083] Since the detection optical path 103 is now used to perform defect detection on the i-th object to be tested 107, and the first scanning optical path 101 or the second scanning optical path 102 is in an idle state, for the idle target scanning optical path, the i+1-th object to be tested 107 can be set on the light-emitting side of the target scanning optical path, that is, the target scanning position, and the scanning light beam passes through the target scanning optical path and is incident on the i+1-th object to be tested 107, thereby performing defect scanning processing on the i+1-th object to be tested 107.

[0084] refer to Figure 1 As shown, the scanning light source is illustrated by taking the first scanning light source 8 as an example. The scanning light beam emitted by the scanning light source passes through the second polarizing module 9 and the target reflector 30 and is incident on the first scanning light path 101 to perform defect scanning on the object to be tested 107 placed on the first platform. At the same time, the detection light beam emitted by the detection light source 1 is incident on the detection light path 103 and performs defect detection on another object to be tested 107 located on the second platform 19.

[0085] In short, by setting the defect detection process of the i-th object to be tested 107 and the defect scanning process of the next object to be tested 107 to be carried out simultaneously, it can be ensured that both platforms (the first platform and the second platform 19) can carry the object to be tested 107 for processing, and there will be no idle platform situation. The simultaneous processing of the two objects to be tested 107 greatly improves the detection efficiency. In addition, the present application cooperates with the two platforms by setting three positions (the first scanning position 104, the second scanning position 105 and the detection position 106). The first platform can be moved to the first scanning position 104 that will not be occupied by the second platform 19, so that the first platform and the second platform 19 can start moving at the same time, greatly improving the platform movement efficiency and making the flow of the object to be tested 107 more convenient. In addition, since the light beam power required for defect detection and defect scanning is different, by setting two light sources, namely the scanning light source and the detection light source 1, there is no need to adjust the light power of the light source during the entire detection process, which saves time, does not require the use of a switching module, and the power control is more stable. Moreover, compared with setting one light source, the optical power of the two light sources can be smaller, thus avoiding the increase in detection cost due to setting only one light source with higher optical power, and achieving both higher detection efficiency and lower detection cost.

[0086] In practical applications, the basic optical path 100 may also include other optical elements to improve the quality of the light beam. As an example, the basic optical path 100 may also include a slow shutter 2, a beam pointing stabilization module 3, and a beam expansion module 4. The slow shutter 2 is used to control whether the light emitted by the detection light source 1 continues to propagate. When the slow shutter 2 is in the closed state, no light beam passes through. When the slow shutter 2 is in the open state, the light beam emitted by the detection light source 1 can pass through. The beam pointing stabilization module 3 can be used to correct the direction of the light beam. After the detection light source 1 has been used for a period of time, its pointing direction may undergo a slight angular deviation. Due to the long optical path of the subsequent light path, it may no longer meet the requirements of the shaping element when it reaches the shaping module. Therefore, a beam stabilization module 3 can be set in the basic optical path 100 to adjust the direction of the light beam. The beam pointing stabilization module 3 includes a first reflector, a second reflector, a third reflector, a fourth reflector, a first adjustment component (not shown in the figure), a second adjustment component (not shown in the figure), a first detector (not shown in the figure), and a second detector (not shown in the figure). The light beam passes through the first, second, third, and fourth reflectors in sequence before exiting the beam stabilization system. After passing through the second reflector, a portion of the light is transmitted through the second reflector and transmitted to the first detector. After passing through the fourth reflector, a portion of the light is transmitted through the fourth reflector and transmitted to the second detector. When the light emitted by the laser light source becomes unstable and deflects, the light spots on the first and second detectors simultaneously deflect. The first and second reflectors can be adjusted based on the positions of the light spots transmitted to the first and second detectors, thereby maintaining a stable light output direction from the beam stabilization system. The beam expansion module 4 can be used to amplify the light spot diameter to meet the requirements of the subsequent shaping module. For example, the beam expansion module 4 can be a one-dimensional beam expander designed based on a cylindrical lens pair and an anamorphic prism pair. It primarily adjusts the narrow axis of the beam so that the output beam meets a predetermined size requirement to meet the requirements of the subsequent shaping optical elements. The larger the beam size, the narrower the compressible line width. The narrow axis is the line width direction corresponding to the final line spot, also known as the short side of the line spot.

[0087] refer to Figure 1 As shown, the light beam emitted by the detection light source 1 passes through the slow shutter 2, the beam pointing stabilization module 3, the beam expansion module 4 and the first spectrometer module 5 in sequence to obtain a detection beam. The detection beam is incident on the detection optical path 103 to perform defect detection on the object to be tested 107 (Wafer II) located on the second platform 19.

[0088] In a possible implementation, the detection system may further include a switching module; the switching module is configured to switch the scanning light beam between the first scanning light path 101 and the second scanning light path 102 .

[0089] Since the first scanning optical path 101 and the second scanning optical path 102 share the same scanning light source, a switching module can be added to the optical path to switch the scanning optical paths. The switching module can be, for example, a reflector, or other components that can change the propagation direction of the scanning beam.

[0090] refer to Figure 1 As shown, the switching module is used as the target reflector 30 for the purpose of illustration. When the switching module is located in the optical path, the scanning light beam is redirected by the switching module and then incident on the first scanning optical path 101. In addition, if the switching module is removed from the optical path, the scanning light path can be incident on the second scanning optical path 102.

[0091] In summary, by adding a switching module in the optical path to realize the switching of the scanning optical path, the two scanning optical paths can share the same scanning light source, reducing the number of light sources and lowering costs, and can conveniently and accurately realize optical path switching, so as to perform defect scanning on the object to be tested 107 at different positions.

[0092] In a possible implementation, the basic optical path further includes a first splitting module; the first splitting module is used to split the light beam emitted by the detection light source 1 into a detection beam and a redundant beam transmitted in different directions, and to adjust the optical power of the detection beam.

[0093] Specifically, the detection light beam emitted by the detection light source 1 passes through the first light splitting module and can be divided into a detection light beam and a redundant light beam. The detection light beam can be incident on the detection light path 103 for defect detection.

[0094] Since different objects to be tested 107 may require detection beams with different optical powers for detection, the optical power of the detection beam needs to be adjusted, and the optical power adjustment can be performed through the first light splitting module.

[0095] In summary, by adjusting the optical power of the detection light beam through the first light splitting module, it is possible to adapt to various objects under test 107 for defect detection, thereby achieving targeted detection of the objects under test 107 and making the defect detection results more accurate.

[0096] In one possible implementation, the first optical splitting module may include a second half-wave plate 6 and a second polarization beam splitter (PBS) 7. The optical power of the detection beam can be adjusted by rotating the second half-wave plate 6. The operation is simple and can achieve precise adjustment of the optical power.

[0097] In a possible implementation, the basic optical path may further include a light absorbing module 26 located on a side of the redundant light beam emitted by the first light splitting module 5 , and the light absorbing module 26 is used to absorb the redundant light beam.

[0098] Since the detection optical path 103 only needs to use the detection beam for defect detection, the other portion of the light beam emitted by the first optical splitter module 5, namely the redundant light beam, does not need to be incident on the detection optical path 103. To prevent the redundant light beam from interfering with defect detection, a light absorption module 26 can be provided. The redundant light beam is absorbed by the light absorption module 26 after being emitted from the first optical splitter module 5, thereby preventing light leakage and adverse effects on the detection optical path 103. The variable attenuation function of the detection optical path 103, that is, the adjustable optical power, can also be retained. As an example, the light absorption module 26 can be a light trap.

[0099] In summary, by setting up the light absorption module 26, the stray light after splitting, i.e., the redundant light beam, can be absorbed to avoid affecting the detection light path 103. In addition, the optical power attenuation adjustment of the detection light beam can be realized, which can help adjust the detection light beam to the appropriate optical power.

[0100] In a possible implementation, the first scanning optical path 101 , the second scanning optical path 102 , or the detection optical path 103 may include a polarization module, and the polarization module is used to adjust the polarization state of the light beam.

[0101] Specifically, due to the different materials of the object to be tested 107 , the polarization state of the light beam required for defect scanning or defect detection may also be different. Therefore, a polarization module may be provided to adjust the polarization state of the light beam.

[0102] The polarization module can realize P / S polarization, left-hand (CL) polarization, right-hand (CR) polarization and N / A (empty), refer to Figure 3 , which is a schematic diagram of a polarization module provided in an embodiment of the present application. The polarization module may include four polarizers to achieve four polarization states. The polarization module may be driven to rotate by a motor to achieve a desired polarization state.

[0103] In practical applications, a polarizing module can be provided in the detection optical path 103, and the first scanning optical path 101 and the second scanning optical path 102 can share the same polarizing module to reduce component costs. Figure 1 As shown, the detection optical path 103 includes a first polarizing module 21 , and the entire optical path also includes a second polarizing module 9 . The second polarizing module 9 is disposed between the first scanning optical path 101 and the first scanning light source 8 .

[0104] In summary, by providing the polarization module, the polarization state of the detection beam or the scanning beam can be matched with the object to be tested 107 , thereby achieving accurate scanning and accurate detection of various objects to be tested 107 .

[0105] In one possible implementation, the scanning light source may include a first scanning light source 8 and a second scanning light source 14, wherein the first sub-scanning beam emitted by the first scanning light source 8 is used to be incident on the first scanning light path 101, and the second sub-scanning beam emitted by the second scanning light source 14 is used to be incident on the second scanning light path 102.

[0106] Specifically, an independent scanning light source can be configured for each scanning optical path, that is, the scanning light source includes a first scanning light source 8 and a second scanning light source 14. The first scanning light source 8 is used to emit a first sub-scanning beam, which can propagate in the first scanning optical path 101, so as to perform defect scanning using the first scanning optical path 101. The second scanning light source 14 is used to emit a second sub-scanning beam, which can propagate in the second scanning optical path 102, so as to perform defect scanning using the second scanning optical path 102.

[0107] refer to Figure 4 As shown, the first sub-scanning beam emitted by the first scanning light source 8 passes through the first switch 27, the second polarizing module 9, the first shaping module 10, the first reflector 11, and the second reflector 12, and is incident on the surface of the object to be tested 107, thereby achieving defect detection on the object to be tested 107 (wafer 1). If the second platform 19 carrying the object to be tested 107 is located on the light exit side of the second scanning optical path 102, the second sub-scanning beam emitted by the second scanning light source 14 passes through the second switch 28, the third polarizing module 15, the second shaping module 16, the third reflector 17, and the fourth reflector 18, and is incident on the surface of the object to be tested 107. The detection beam is used to pass through the fifth reflector 20, the first polarizing module 21, the third switch 22, the sixth reflector 23, the third shaping module 24, and the seventh reflector 25 in sequence, and is incident on the surface of the object to be tested 107. Among them, the number of reflectors and the angles of each reflector can be determined based on the simulation results of the scattered field model to achieve the best incidence effect.

[0108] In short, by setting a scanning light source for each of the two scanning light paths, no matter which scanning light path is used for defect scanning, there is no need to adjust the light path structure. For example, there is no need to adjust the switching module to change the propagation direction of the light beam. Only the corresponding scanning light source needs to be turned on to perform defect scanning, which avoids adjusting the light path, makes operation more convenient, and the optical power control of each scanning light beam will be more independent and more stable.

[0109] In one possible implementation, the first scanning optical path 101 may include a first switch 27, which is used to control whether the first sub-scanning beam can be incident on the first scanning optical path 101; the second scanning optical path 102 includes a second switch 28, which is used to control whether the second sub-scanning beam can be incident on the second scanning optical path 102.

[0110] Specifically, when an independent scanning light source is configured in each scanning light path, a switch can be added to each scanning light path. The first switch 27 is located in the first scanning light path 101, for example, placed behind the first scanning light source 8. When the first switch 27 is in the open state, the first sub-scanning light beam emitted by the first scanning light source 8 can continue to propagate through the first switch 27. When the first switch 27 is in the closed state, the first sub-scanning light beam cannot continue to propagate. The second switch 28 is located in the second scanning light path 102. When the second switch 28 is in the open state, the second sub-scanning light beam emitted by the second scanning light source 14 can continue to propagate through the second switch 28. When the second switch 28 is in the closed state, the second sub-scanning light beam cannot continue to propagate. The first switch 27 and the second switch 28 can be, for example, a shutter, or other components, such as a sliding toggle switch, so as to realize the alternating opening of the two switches.

[0111] refer to Figure 4 As shown, the first switch 27 is located between the first scanning light source 8 and the first shaping module 10 , and the second switch 28 is located between the second scanning light source 14 and the second shaping module 16 .

[0112] In a possible implementation, the optical power of the detection light source 1 is greater than the optical power of the scanning light source.

[0113] Specifically, the optical power of the scanning beam required for defect scanning can be lower than the optical power of the detection beam used for defect detection. Defect scanning primarily utilizes a scanning beam with lower optical power to identify large defects, such as those larger than 500 nm, to avoid situations where excessive optical power could cause defects to be swept out, such as large particle defects, thereby contaminating the object under test. During defect detection, a detection beam with higher optical power is primarily used to identify small defects. Thus, through the two steps of defect scanning and defect detection, all defects in the object under test 107 can be identified.

[0114] In a possible implementation, the first scanning optical path 101 , the second scanning optical path 102 , or the detection optical path 103 may include a shaping module, and the shaping module is used to perform beam shaping processing.

[0115] Specifically, the shaping module can be understood as a module that shapes the light beam to meet the beam requirements during defect detection or defect scanning. For example, a Gaussian beam can be shaped into a flat-top line spot with high uniformity and narrow line width. Figure 4 As shown, a first shaping module 10 can be provided in the first scanning optical path 101, a second shaping module 16 can be provided in the second scanning optical path 102, and a third shaping module 24 can be provided in the detection optical path 103. The three shaping modules can be the same or different, and can be determined based on the actual optical path and the back intercept of the shaping element used.

[0116] The shaping module can be a collimated flat-top shaping element, or a free-form surface shaping element. The free-form surface shaping element can provide single-degree-of-freedom linewidth compression along the narrow side direction. The shaping module can be implemented in the form of diffractive optical elements (DOEs), microlens arrays, prisms, etc. The shaping module can also include a one-dimensional beam expander, a collimated flat-top shaping element, a free-form surface shaper, or any other suitable shaping module known in the art.

[0117] In summary, by providing a shaping module in the scanning optical path or the detection optical path 103, the shape of the light beam can be adjusted to a suitable shape, thereby improving the accuracy of defect scanning or defect detection.

[0118] In one possible implementation, the detection optical path 103 may further include a third switch 22; when the third switch 22 is in an open state, the third switch 22 is used to enable the detection light beam to perform defect detection on target defects belonging to the second defect category on the surface of the object to be tested 107; when the third switch 22 is in a closed state, the third switch 22 is used to enable the detection light beam to not perform defect detection on target defects belonging to the first defect category on the surface of the object to be tested 107; in the defect scanning result obtained by completing the defect scan on the i-th object to be tested 107, the minimum value of the first light intensity range corresponding to the first defect category is greater than the maximum value of the second light intensity range corresponding to the second defect category.

[0119] Specifically, the third switch 22 may be located in the detection light path 103, and is used to control whether the detection light beam can be incident on the surface of the object to be detected 107. Figure 1 As shown, a third switch 22 is provided in the detection optical path 103. The first defect category can also be any defect category. The light intensity range corresponding to the first defect category can be recorded as a first light intensity range, and the light intensity range corresponding to the second defect category can be recorded as a second light intensity range. The minimum value of the first light intensity range is greater than the maximum value of the second light intensity range, that is, the light intensity in the first light intensity range is greater than the light intensity in the second light intensity range.

[0120] Because large defects correspond to higher light intensities during defect scanning, while small defects correspond to lower light intensities, the first defect category represents large defects, such as large particle defects, while the second defect category represents small defects, such as small particle defects. To avoid overscanning large defects during defect detection, when traversing to a large defect, i.e., the first defect category, the large defect can be skipped without detection. That is, when the target defect belongs to the second defect category, it indicates that the target defect is a small defect. Since defect detection primarily targets this type of defect, the third switch 22 can be controlled to be in the open state, allowing the detection beam to pass through the third switch 22 to detect the target defect on the surface of the object under test 107.

[0121] When the target defect belongs to the first defect category, it means that the target defect is a large-size defect. Since it has been detected through defect scanning processing, and in order to avoid scanning explosion, there is no need to perform defect detection again, the third switch 22 can be controlled to be in a closed state, and the detection light beam is blocked by the third switch 22 and cannot continue to propagate backward, so that the target defect is not detected.

[0122] In other words, when performing defect detection on the object to be tested 107, if the detection beam is incident on the location of a large defect, the third switch 22 is quickly closed. After skipping the location of the large defect, the third switch 22 is opened again to continue defect detection for small defects.

[0123] In summary, by setting the third switch 22 in the detection optical path 103, by closing the third switch 22, large-size defects and small-size defects can be easily detected using different optical powers. The operation is convenient, the cost is low, and the large-size defects can be avoided to the greatest extent.

[0124] Third switch 22 can be used in the following scenarios: when the platform is moving with the object under test 107, just before the incident light spot reaches the exterior of the object under test 107, third switch 22 can be closed to prevent the strong laser from damaging other precision optomechanical structures within the machine. When using an edge-clamping chuck for defect detection, the shutter must be closed in the area with the clamping pin (PIN). After the PIN is cleared, third switch 22 is opened. During regular maintenance or troubleshooting, third switch 22 must be closed to prevent injury to operators from the strong laser.

[0125] refer to Figure 5 The figure is a flow chart of a detection method provided in an embodiment of the present application. The method is applied to a detection system and may include the following steps.

[0126] S101 , moving the i-th object to be tested 107 from the initial scanning position to the detection position 106 , and turning on the detection light source 1 .

[0127] The initial scanning position can be understood as the position where the i-th object to be tested 107 is scanned for defects. The initial scanning position can be the first scanning position 104 or the second scanning position 105, that is, when the i-th object to be tested 107 is placed on the first platform 13, the initial scanning position is the first scanning position 104, if the i-th object to be tested 107 is placed on the second platform 19, then the initial scanning position is the second scanning position 105.

[0128] The i-th object under test 107 has completed defect scanning at the initial scanning position by the scanning beam, that is, before S101, the i-th object under test 107 is located at the initial scanning position, and the scanning beam is incident on the corresponding scanning optical path, thereby realizing defect scanning processing of the i-th object under test 107.

[0129] After the i-th object to be tested 107 is subjected to defect scanning, it needs to be subjected to defect detection. At this time, the platform carrying the i-th object to be tested 107 needs to be moved from the initial scanning position to the detection position 106, and the detection light source 1 needs to be turned on so that defect detection can be performed using the detection light beam emitted by the detection light source 1.

[0130] S102 , positioning the (i+1)th object to be tested 107 at a target scanning position.

[0131] Specifically, the next object to be tested 107, i.e., the (i+1)th object to be tested 107, can be placed on another platform, which is located at the target scanning position. The target scanning position is different from the initial scanning position. When the initial scanning position is the first scanning position 104, the target scanning position is the second scanning position 105. At this time, the (i+1)th object to be tested 107 is placed on the second platform 19 located at the second scanning position 105. When the initial scanning position is the second scanning position 105, the target scanning position is the first scanning position 104. At this time, the (i+1)th object to be tested 107 is placed on the first platform 13 located at the first scanning position 104. S103: Turn on the scanning light source and make the scanning light beam incident on the target scanning light path corresponding to the target scanning position.

[0132] Specifically, when the i-th object under test 107 is scanned for defects at the initial scanning position, the scanning light beam propagates in the scanning light path corresponding to the initial scanning position. When the i+1-th object under test 107 is scanned for defects, the i+1-th object under test 107 is located at the target scanning position. Therefore, the scanning light source needs to be turned on so that the scanning light beam is incident on the target scanning light path corresponding to the target scanning position. When the target scanning position is the first scanning position 104, the target scanning light path is the first scanning light path 101. When the target scanning position is the second scanning position 105, the target scanning light path is the second scanning light path 102.

[0133] S104 , while performing defect detection on the i-th object under test 107 using a detection beam based on the detection optical path 103 , performing defect scanning on the (i+1)-th object under test 107 using a scanning beam based on the target scanning optical path.

[0134] Specifically, at this time, the i-th object under test 107 is located at the detection position 106, and the i+1-th object under test 107 is located at the second scanning position 105. The detection light beam propagates in the detection optical path 103 and is incident on the surface of the i-th object under test 107, thereby achieving defect detection at various positions on the i-th object under test 107. At the same time, the next object under test 107 can be processed, so that the scanning light beam propagates in the target scanning optical path and is incident on the surface of the i+1-th object under test 107, thereby achieving defect scanning at various positions on the i+1-th object under test 107.

[0135] In short, by setting the defect detection process of the i-th object to be tested 107 and the defect scanning process of the next object to be tested 107 to be carried out simultaneously, it can be ensured that both platforms (the first platform and the second platform 19) can carry the object to be tested 107 for processing, and there will be no idle platform situation. The simultaneous processing of the two objects to be tested 107 greatly improves the detection efficiency. In addition, the present application cooperates with the two platforms by setting three positions (the first scanning position 104, the second scanning position 105 and the detection position 106). The first platform can be moved to the first scanning position 104 that will not be occupied by the second platform 19, so that the first platform and the second platform 19 can start moving at the same time, greatly improving the platform movement efficiency and making the flow of the object to be tested 107 more convenient. In addition, since the light beam power required for defect detection and defect scanning is different, by setting two light sources, namely the scanning light source and the detection light source 1, there is no need to adjust the light power of the light source during the entire detection process, which saves time, does not require the use of a switching module, and the power control is more stable. Moreover, compared with setting one light source, the optical power of the two light sources can be smaller, thus avoiding the increase in detection cost due to setting only one light source with higher optical power, and achieving both higher detection efficiency and lower detection cost.

[0136] Next, an example is given to illustrate the process of performing defect detection and defect scanning simultaneously.

[0137] refer to Figure 2 and Figure 4As shown, in the first stage, the first platform is in the first scanning position 104, the i-th object to be tested 107 (wafer 1) is placed on the first platform, the first switch 27 is turned on, the second switch 28 and the slow shutter 2 are turned off, at this time, the first sub-scanning beam emitted by the first scanning light source 8 passes through the first scanning optical path 101 to reach the surface of the object to be tested 107, and defect scanning begins. The second platform 19 is in the second scanning position 105, the second platform 19 has not yet carried the object to be tested 107, and the detection position 106 is currently vacant. After the defect scan is completed, the detection system records the defect position, and at this time all three switches are in the off state. Entering the second stage, refer to Figure 6 and Figure 7 As shown, the (i+1)th DUT 107 (wafer II) is placed on the second platform 19. The second switch 28 is turned on, and the second sub-scanning beam enters the second scanning optical path 102. It reaches the surface of DUT 107 and begins scanning for defects. Simultaneously, the first platform carries the (i)th DUT 107 to the inspection position 106. Both the slow shutter 2 and the third switch are turned on, and defect inspection begins. At this point, the first scanning position 104 is vacant. In short, the defect inspection process for the (i+1)th DUT 107 and the defect scanning process for the (i+1)th DUT 107 are performed simultaneously.

[0138] In a possible implementation, the scanning light source may include a first scanning light source 8 and a second scanning light source 14. The scanning light source is turned on, and the scanning beam is incident on the target scanning light path corresponding to the target scanning position, which may be specifically S201-S202.

[0139] S201 , when the target scanning position is the first scanning position 104 and the target scanning optical path is the first scanning optical path 101 , turn on the first scanning light source 8 so that the first sub-scanning beam emitted by the first scanning light source 8 is incident on the first scanning optical path 101 corresponding to the first scanning position 104 .

[0140] Specifically, since the target scanning position can be either the first scanning position 104 or the second scanning position 105, when the target scanning position is the first scanning position 104 and an independent first scanning light source 8 is configured in the first scanning optical path 101, the first scanning light source 8 can be turned on, and the first sub-scanning beam emitted by the first scanning light source 8 can be incident on the first scanning optical path 101 to perform defect scanning.

[0141] S202 , when the target scanning position is the second scanning position 105 and the target scanning optical path is the second scanning optical path 102 , turn on the second scanning light source 14 so that the second sub-scanning beam emitted by the second scanning light source 14 is incident on the second scanning optical path 102 corresponding to the second scanning position 105 .

[0142] When the target scanning position is the second scanning position 105, the target scanning optical path is the second scanning optical path 102, and the second scanning light source 14 can be turned on. The second sub-scanning beam emitted by the second scanning light source 14 can be incident on the second scanning optical path 102, thereby realizing defect scanning.

[0143] In short, when independent scanning light sources are respectively configured in the two scanning light paths, when a scanning light path is needed for defect scanning, the corresponding scanning light source can be turned on without switching the light path, which makes the operation more convenient.

[0144] In one possible implementation, the detection system may further include a switching module; turning on the scanning light source, and making the scanning light beam incident on the target scanning light path corresponding to the target scanning position. Specifically, turning on the scanning light source, and making the scanning light beam incident on the target scanning light path corresponding to the target scanning position through the switching module.

[0145] Specifically, when two scanning light paths share the same scanning light source, for example, both use the scanning light beam emitted by the first scanning light source 8, the propagation direction of the scanning light beam can be changed by the switching module so that it is incident on the target scanning light path.

[0146] As an example, when the switching module is the target reflector 30, by moving the target reflector 30 into the optical path, the scanning beam can be incident on the first scanning optical path 101, and by moving the target reflector 30 out of the optical path, the scanning beam can be incident on the second scanning optical path 102.

[0147] In short, by using a switching module to change the propagation direction of the scanning light beam, the two scanning light paths can share the same scanning light source, which reduces the number of scanning light sources and lowers the optical path cost.

[0148] In one possible implementation, the basic optical path may further include a first spectrometer module; before performing defect detection on the i-th object to be tested 107 through the detection light beam based on the detection optical path 103, a first optical power adapted to the i-th object to be tested 107 may also be determined; and the detection light beam incident into the detection optical path 103 is enabled to reach the first optical power through the first spectrometer module.

[0149] Specifically, since the optical power of the detection beam required for defect detection on different objects under test 107 may be different, a matching first optical power can be determined based on the object under test 107. The first optical splitting module 5 can achieve stepless optical splitting. By adjusting the first optical splitting module 5, the optical power of the detection beam entering the detection optical path 103 can be adjusted to reach the first optical power.

[0150] In summary, by adjusting the optical power of the detection light beam through the first light splitting module 5, the optical power control is more flexible and accurate, and more accurate defect detection can be achieved.

[0151] In one possible implementation, the method may further include, after completing defect detection on the i-th object under test 107 , moving the i-th object under test 107 from the detection position 106 to the initial scanning position; at the initial scanning position, replacing the i-th object under test 107 with the (i+2)-th object under test 107 .

[0152] After defect detection is completed for the i-th object under test 107, the i-th object under test 107 can be moved to its original scanning position, i.e., the initial scanning position. For example, if the i-th object under test 107 is placed on the first platform 13, since the first platform 13 is moved from the first scanning position 104 to the detection position 106 for defect detection, after defect detection is completed, the first platform 13 can be moved back to the first scanning position 104 to facilitate replacement of the object under test. If the i-th object under test 107 is placed on the second platform 19, since the second platform 19 is moved from the second scanning position 105 to the detection position 106 for defect detection, after defect detection is completed, the second platform 19 can be moved back to the second scanning position 105 to facilitate replacement of the object under test.

[0153] Specifically, after defect scanning and defect detection are completed for the i-th object under test 107 , the i-th object under test 107 may be removed and replaced by the next object under test 107 that needs to be processed, ie, the i+2-th object under test 107 .

[0154] As an example, the entire process can also include a third stage, refer to Figure 8 and Figure 9 As shown, the third switch is closed, and the first platform carrying the i-th DUT 107 moves to the first scanning position 104. It performs actions such as unloading and wafer rotation, placing the i+2-th DUT 107 on the first platform and returning the i-th DUT 107 to the transport pod (FOUP). The second platform 19 carries the i+1-th DUT 107 to the inspection position 106. The third switch 22 is open, and defect detection begins. At the same time, the scanning beam enters the first scanning optical path 101, reaches the surface of the i+2-th DUT 107 (i.e., wafer III), and begins defect scanning. The second scanning position 105 is now idle.

[0155] That is, for each DUT 107 , after defect detection is completed, it is moved to the original scanning position and transmitted from the same DUT 107 transmission port, thereby avoiding confusion in the DUT 107 records and ensuring that the order of the DUT 107 is strictly correct.

[0156] In another possible implementation, if the object under test 107 is moved from the first scanning position 104 to the detection position 106 for defect detection, the object under test 107 can also be moved from the detection position 106 to the second scanning position 105 after the defect detection is completed, and the object under test 107 can be replaced at the object under test 107 transmission port near the second scanning position 105, thereby improving the flexibility of the flow of the object under test 107.

[0157] In one possible implementation, after completing defect detection on the i-th object under test 107 and obtaining a defect detection result, the defect detection result and the defect scanning result obtained by completing defect scanning on the i-th object under test 107 are fused to obtain a target detection result of the i-th object under test 107; the target detection result is used to identify the defect information of the i-th object under test 107.

[0158] Specifically, after completing defect detection on the i-th object under test 107, a defect detection result can be obtained, which mainly reflects the detection status of small-sized defects. After completing defect scanning processing on the i-th object under test 107, a defect scanning result can be obtained, which mainly reflects the scanning status of large-sized defects.

[0159] Therefore, in order to fully reflect all defects of the object under test 107, the defect scanning result and the defect detection result can be integrated to obtain a target detection result, which can reflect all defects on the surface of the object under test 107. As an example, the target detection result can be a map.

[0160] Furthermore, whether performing defect scanning or defect detection, after image acquisition, the algorithm processing time is positively correlated with the number of defects and the surface roughness of the object under test 107. The greater the number of particles and the rougher the surface of the object under test 107, the longer the algorithm processing time, affecting machine productivity. Therefore, the software architecture can be reconfigured to fully parallelize the duplex motion time and image processing time. Furthermore, each defect detection result and defect scanning result for each object under test 107 can be uniquely labeled for differentiation. This maximizes the inspection yield of the object under test 107 while maintaining machine detection sensitivity.

[0161] In this way, by combining the defect scanning results and the defect detection results, various defects on the object to be tested 107 can be comprehensively and completely identified, thereby improving the coverage of defect identification.

[0162] In one possible implementation, after completing a defect scan on the i-th object under test 107, the defect scan result includes the defect location of each defect on the surface of the i-th object under test 107 and the light intensity of each defect. Before performing defect detection on the i-th object under test 107 using a detection beam via the detection optical path 103, the method may further include: determining the defect category to which each defect belongs based on the light intensity; different defect categories correspond to different light intensity ranges. Then, step S104, performing defect detection on the i-th object under test 107 using the detection beam via the detection optical path 103, may specifically include steps S1041 and S1042.

[0163] S1041 , based on the detection light path 103 , the detection light beam traverses each position on the surface of the i-th object to be detected 107 to perform defect detection.

[0164] S1042 , when performing defect detection on a target defect located at a target defect position, performing defect detection on the target defect using a detection light beam having a target optical power; the target optical power is determined based on a defect category to which the target defect belongs.

[0165] Specifically, the defect scanning result of the i-th object to be tested 107 may include the defect position of each defect and the light intensity corresponding to each defect. That is, when performing defect scanning, the detection system can record the position of each defect and the light intensity at the defect.

[0166] Defect categories can be divided based on the size of the defect. For example, defect categories include large-size defects and small-size defects. Defect types include particles, area defects, slipline defects, cluster defects, scratches, etc. Defects of the same type but different categories (large-size defects, small-size defects) have different corresponding light intensity ranges. For example, the light intensity range corresponding to defect category 1 is X1~X2, and the light intensity range corresponding to defect category 2 is X3~X4. For a certain defect, the light intensity at the defect is compared with the light intensity range to determine the defect category corresponding to the defect. For example, a large-size defect can be a defect with a size greater than 500nm.

[0167] During defect detection in S104, corresponding processing can be performed based on different defect types. The detection beam can traverse various locations on the surface of the i-th object under test 107. For example, the platform carrying the i-th object under test 107 can move the object under test 107, so that the detection beam is irradiated at different locations on the object under test 107, thereby traversing various defects.

[0168] The target defect can be any defect on the object under test 107. The target defect position can be understood as the specific location of the target defect on the surface of the object under test 107, which can be represented, for example, by horizontal and vertical coordinates. When traversing to the target defect, the corresponding target optical power can be determined based on the defect category to which the target defect belongs. The target optical power is the optical power of the detection beam when performing defect detection on the target defect. Different defect categories correspond to different detection beam powers.

[0169] In short, for defects belonging to different categories, selecting the optical power of the matching detection beam for defect detection can achieve targeted detection of various defects, thereby improving the accuracy of the final detection results.

[0170] In one possible implementation, the optical power of the scanning beam is less than the optical power of the detection beam; when the defect category to which the target defect belongs is the first defect category, the target optical power is a first value; when the defect category to which the target defect belongs is the second defect category, the target optical power is a second value; the minimum value of the first light intensity range corresponding to the first defect category is greater than the maximum value of the second light intensity range corresponding to the second defect category; the first value is less than the second value.

[0171] Specifically, the optical power of the scanning beam required for defect scanning can be lower than the optical power of the detection beam used for defect detection. Defect scanning primarily utilizes a scanning beam with lower optical power to identify large defects, thereby preventing defects from being swept out due to excessive optical power. For example, large particle defects could be swept out and contaminate the object under test. During defect detection, smaller defects are primarily identified using a detection beam with higher optical power. Thus, through the two steps of defect scanning and defect detection, all defects in the object under test 107 can be identified.

[0172] The first defect category can also be any defect category. The light intensity range corresponding to the first defect category can be recorded as the first light intensity range, and the light intensity range corresponding to the second defect category can be recorded as the second light intensity range. The minimum value of the first light intensity range is greater than the maximum value of the second light intensity range, that is, the light intensity in the first light intensity range is greater than the light intensity in the second light intensity range.

[0173] Since during the defect scanning process, the light intensity corresponding to large-sized defects is larger and the light intensity corresponding to small-sized defects is smaller, the first defect category represents large-sized defects, such as large particle defects, and the second defect category represents small-sized defects, such as small particle defects.

[0174] To avoid overexploding large defects during defect detection, the target optical power can be set to a smaller first value when traversing to large defects (the first defect category). This lower optical power prevents damage to large defects and contamination of the DUT. When traversing to small defects (the second defect category), the target optical power can be set to a larger second value to accurately detect smaller defects.

[0175] In practical applications, when the target defect category is the first defect category, using the smaller first value of the target optical power can mean reducing the target optical power or setting the target optical power to 0, i.e., not detecting large defects. Reducing the target optical power can involve switching an acousto-optic modulator (AOM) to reduce the optical power. Setting the target optical power to 0 can also mean preventing the detection beam from being incident on the location of large defects.

[0176] In a possible implementation, the detection optical path 103 may further include a third switch 22 ; S1042 performs defect detection on a target defect using a detection light beam having a target optical power, which may specifically include S10421 - S10422 .

[0177] S10421, when the target defect belongs to the second defect category, the third switch 22 is controlled to be in an open state, and the detection light beam passes through the third switch 22 to perform defect detection on the target defect.

[0178] S10422, when the target defect belongs to the first defect category, the third switch 22 is controlled to be in an off state, the detection light beam is blocked by the third switch 22, and the target defect is not detected.

[0179] Specifically, the third switch 22 can be located in the detection optical path 103 and is used to control whether the detection light beam can be incident on the surface of the object under test 107. When the target defect belongs to the second defect category, it indicates that the target defect is a small defect. Defect detection is mainly targeted at this type of defect. Therefore, the third switch 22 can be controlled to be in the open state, allowing the detection light beam to pass through the third switch 22 to detect the target defect on the surface of the object under test 107.

[0180] When the target defect belongs to the first defect category, it means that the target defect is a large-size defect. Since it has been detected through defect scanning processing, and in order to avoid scanning explosion, there is no need to perform defect detection again, the third switch 22 can be controlled to be in a closed state, and the detection light beam is blocked by the third switch 22 and cannot continue to propagate backward, so that the target defect is not detected.

[0181] In other words, when performing defect detection on the object to be tested 107, if the detection beam is incident on the location of a large defect, the third switch 22 is quickly closed. After skipping the location of the large defect, the third switch 22 is opened again to continue defect detection for small defects.

[0182] In summary, by setting the third switch 22 in the detection optical path 103, by closing the third switch 22, large-size defects and small-size defects can be easily detected using different optical powers. The operation is convenient, the cost is low, and the large-size defects can be avoided to the greatest extent.

[0183] In this application, the scanning optical path can be a brightfield scanning optical path or a darkfield scanning optical path, and the detection optical path can be a brightfield detection optical path or a darkfield detection optical path. That is, both the scanning optical path and the detection optical path can perform brightfield processing or darkfield processing. Brightfield processing uses reflected light from the surface of the object under test 107 to image defects, while darkfield processing uses scattered light from the surface of the object under test 107 to image defects. The optical paths used for brightfield processing and darkfield processing are described in detail below.

[0184] In one possible implementation, when performing brightfield processing or darkfield processing, one or more collection channels can be positioned above the detection or scanning position. For example, the collection channels can be positioned directly above or diagonally above the detection or scanning position. The collection channels are configured to receive a light beam from the upper surface of the object under test 107 for imaging. The collection channels are provided with one or more corresponding detectors, which are configured to achieve imaging based on the light beam.

[0185] The detector may include any suitable detector known in the art, such as a discrete photomultiplier tube (PMT), a charge-coupled device (CCD), a time delay integration (TDI), a complementary metal oxide semiconductor (CMOS) sensor, a PMT array, an electron bombardment CCD (EB-CCD), an electron multiplying CCD (EM-CCD), an enhanced photodiode or an avalanche photodiode (APD) array.

[0186] In one possible implementation, during dark field processing (e.g., a dark field scanning optical path or a dark field detection optical path), a detection system can be set at a suitable position obliquely above the detection position or scanning position. The detection system includes a collection channel and a corresponding detector. The number of detection systems can be one or two. When there is one detection system, the detection system can collect and image scattered light from the upper surface of the object under test 107, thereby achieving defect scanning or defect detection on the upper surface of the object under test. When there are two detection systems, the two detection systems can be set on both sides of the object under test 107, for example, they can be set symmetrically or asymmetrically.

[0187] In one possible implementation, when performing dark field processing to collect scattered light, multiple detection systems can be provided on the object under test 107. The detection systems include collection channels and corresponding detectors. The multiple detection systems can be symmetrically distributed along a perpendicular line to the surface of the object under test 107 and symmetrical about the plane of incidence. When defects on the surface of the object under test 107 are symmetrical, the signals received by the two symmetrical detection systems are identical. When defects on the surface of the object under test 107 have different geometric characteristics, the signals received by the two symmetrical detection systems are different, thereby enabling the determination of the geometric characteristics of the defects. Of course, the multiple detection systems can also be distributed asymmetrically.

[0188] In one possible implementation, the collection channel can be a normal collection channel or a non-normal collection channel. A normal collection channel is a collection channel that is in the normal direction of the surface of the object under test 107 and can be considered to be directly above the object under test 107. A non-normal collection channel is a collection channel that deviates from the normal direction of the surface of the object under test 107 and can be considered to be diagonally above the object under test 107.

[0189] In one possible implementation, the light source mentioned in this application may include any suitable light source, such as a laser, a continuous wave (CW) laser, or a pulsed laser. In addition, the light source may be configured to generate light of any suitable wavelength (e.g., approximately 355 nm, approximately 266 nm, or approximately 193 nm).

[0190] In one possible implementation, the collection channel may include a scattered light collector and some additional optical elements that may be coupled to the scattered light collector. The collector includes but is not limited to an objective lens for collecting at least a portion of the sample light of the object to be measured. The additional optical elements may be, for example, one or more apertures, one or more lenses, one or more separators, one or more polarization elements, one or more filters, one or more reflective optical elements, and one or more refractive optical elements.

[0191] In one possible implementation, the platform (e.g., the first platform 14 or the second platform 19) can be an edge clamping chuck, a vacuum chuck, etc. One platform can support multiple object 107 diameters (e.g., 300 mm and 450 mm) or a single object 107 diameter.

[0192] In one possible implementation, the optical path may also include an axis coupled to the chuck and coupled to a positioning subsystem. The positioning subsystem may include various components configured to rotate and / or translate the axis, such as motors, gears, etc. The axis may be coupled to the chuck in such a manner that rotation and / or translation of the axis causes rotation and / or translation of the platform, thereby causing rotation and / or translation of the object under test 107. The platform may translate the object under test 107 in a spiral or XY manner, or some combination of the two as further described herein. In particular, in addition to spiral scanning as described above, XY serpentine scanning and RT-XY hybrid scanning may be used to translate the object under test 107 relative to the illumination and collection optical devices.

[0193] In a possible implementation, the light beam emitted by the light source may be incident vertically onto the surface of the object to be measured 107 , or may be incident obliquely onto the surface of the object to be measured 107 .

[0194] In a possible implementation, the scattered light or reflected light from the surface of the object to be measured 107 is detected, and its exit surface may be perpendicular to the incident surface of the light emitted by the light source, or have an acute angle therebetween.

[0195] In one possible implementation, when brightfield processing is used to scan for defects, a detection system can be set up to collect reflected light, and when darkfield processing is used to detect defects, a detection system can be set up to collect scattered light. Furthermore, during brightfield processing, a detection system located directly above the object under test 107 can collect normally incident reflected light, while a detection system located diagonally above the object under test 107 can collect obliquely incident reflected light. The detection system includes collection channels and corresponding detectors.

[0196] In one possible implementation, multiple light paths, such as a scanning light path or a detection light path, can be configured to emit multiple light beams. These beams can then strike the surface of the object under test 107 at varying angles. Signal light is then reflected or scattered from the surface of the object under test 107, and collected using different detection systems, which include collection channels and corresponding detectors. By providing multiple light beams incident on the object under test 107, defects of varying sizes can be detected. Different angles of incidence between the light beams and the object under test 107 result in varying sensitivity for defect scanning or detection, thereby meeting user requirements for various detection sensitivities. For smaller defects, the sensitivity of defect detection or scanning can be appropriately increased to avoid missed detections.

[0197] In one possible implementation, the light spot emitted by the light source after shaping and irradiating to the surface of the object to be tested 107 can be a point light spot or a line light spot. When performing dark field processing, if there is a defect in the lighting position, the defect will cause part of the light to be emitted upward at various angles in the form of scattered light. Therefore, multiple scattered light collection channels can be set at different positions to realize scattered light intensity detection at different angles, so that the defect information at the position of the light spot can be determined. It can be understood that by collecting signal light through multiple signal collection channels, the detection accuracy can be improved. The detection branch corresponding to each collection channel includes a detection lens group and a detector to realize imaging collection of the signal light. When a line detector is used, the detection area is linear.

[0198] In a possible implementation, the light beam emitted by the light source may be divided into multiple offset light beams, and the phase characteristics between the multiple offset light beams are adjusted so that they can be simultaneously focused on the surface of the object to be measured 107 .

[0199] In one possible implementation, when collecting scattered light (dark field processing) or reflected light (bright field processing) from the surface of the object under test 107, an objective lens with a large numerical aperture (NA) can be used for light collection. That is, the scattered light or reflected light passes through the large NA objective lens before entering the detector. In addition, for the reflected or scattered light, optical elements can be configured to distribute light of different wavelengths or different polarization states to different collection channels.

[0200] In one possible implementation, when collecting scattered light or reflected light from the surface of the object under test 107, the reflected light or scattered light can be split, and the two separated beams of light can enter different collection channels for defect imaging. In one possible implementation, the light beam emitted by the light source can be incident on the surface of the object under test 107 at an angle, or can also be incident at normal incidence, depending on the actual situation.

[0201] In a possible implementation, light scattered by the surface of the object to be measured 107 may be collected and focused by a lens condenser and directed to a detector. As an example, the lens condenser may be ellipsoidal.

[0202] Next, how to realize the movement of the first platform 13 and the second platform 19 is described in detail. Figure 10As shown, it is a schematic diagram of a motion platform provided in an embodiment of the present application. The movement of the first platform 13 and the second platform 19 can be achieved by the motion platform. The motion platform includes a moving plate 301 and a conveying mechanism 302, wherein the first platform 13 is placed on one moving plate 301, and the second platform 19 is placed on another moving plate 301. The conveying mechanism 302 is an XY two-dimensional motion mechanism, and the conveying mechanism 302 may include a linear motor and a guide rail. The conveying mechanism 302 can also complete the movement of the first platform 13 and the second platform 19 by a lead screw or a conveyor belt. The motion platform can realize X, Y and T axis movement, wherein X and Y represent orthogonal coordinate systems, and the T axis represents rotation around the Z axis. The first platform 14 and the second platform 19 can rotate around the T axis on the moving plate 301 respectively. Combined Figure 2 For example, the X- and Y-axis motions can move the first platform 13 and the second platform 19 in the plane of the motion stage, enabling the first platform 13 to switch between the first scanning position 104 and the detection position 106, and the second platform 19 to switch between the second scanning position 105 and the detection position 106. The coordinated motions of the X, Y, and T axes can also achieve spiral scanning (RT), XY serpentine scanning, or RT-XY hybrid scanning of the object to be detected 107.

[0203] The detection method provided in the present application can be applied to a detection system, and specifically the detection system can be controlled by a computer subsystem to adjust the light path, move the platform, etc. The computer subsystem can include any suitable computer system known in the art. For example, the computer subsystem can take various forms, including a personal computer system, a large computer system, a workstation, an image computer, a parallel processor, or any other device known in the art. Generally, the term "computer subsystem" can be broadly defined as comprising any device having one or more processors that execute instructions from a storage medium.

[0204] The various embodiments in this specification are described in a progressive manner. Similar parts between the various embodiments can be referred to in conjunction with each other. Each embodiment focuses on the differences from the other embodiments. In particular, the method embodiments are described briefly because they are generally similar to the system embodiments. For relevant parts, refer to the description of the system embodiments.

[0205] The above is only a preferred embodiment of the present application. Although the present application has been disclosed as a preferred embodiment, it is not intended to limit the present application. Any technician familiar with the art can use the above-disclosed methods and technical contents to make many possible changes and modifications to the technical solution of the present application without departing from the scope of the technical solution of the present application, or modify it into an equivalent embodiment with equivalent changes. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of protection of the technical solution of the present application.

Claims

1. A detection system, characterized in that: The detection system includes a basic optical path, a first scanning optical path, a second scanning optical path, a detection optical path, a first platform, a second platform and a scanning light source; The basic optical path includes a detection light source, the detection light source is used to emit a detection beam, the detection beam is used to be incident on the detection optical path; the scanning light source is used to emit a scanning beam, the scanning beam is used to be incident on the first scanning optical path or the second scanning optical path; The first platform and the second platform are both used to carry the object to be tested, the first platform switches between a first scanning position and a detection position, and the second platform switches between a second scanning position and the detection position; the first scanning position and the second scanning position are respectively located on the light exit side of the first scanning light path and the second scanning light path, and the detection position is located on the light exit side of the detection light path; While the detection optical path is used to perform defect detection on the i-th object to be tested at the detection position through the detection light beam, the target scanning optical path is used to perform defect scanning on the i+1-th object to be tested at the target scanning position through the scanning light beam; the target scanning optical path is the first scanning optical path or the second scanning optical path, and the target scanning position is the first scanning position or the second scanning position; i≥1.

2. The detection system according to claim 1, characterized in that The basic optical path also includes a first light splitting module; The first light splitting module is used to split the light beam emitted by the detection light source into the detection light beam and the redundant light beam transmitted in different directions, and to adjust the optical power of the detection light beam.

3. The detection system according to claim 2, characterized in that The basic optical path further includes a light absorbing module located on a side where the first light splitting module emits the redundant light beam, and the light absorbing module is used to absorb the redundant light beam.

4. The detection system according to claim 2, characterized in that The first light splitting module includes a second half-wave plate and a second polarization beam splitting prism.

5. The detection system according to claim 1, characterized in that The scanning light source includes a first scanning light source and a second scanning light source. The first sub-scanning beam emitted by the first scanning light source is used to be incident on the first scanning light path. The second sub-scanning beam emitted by the second scanning light source is used to be incident on the second scanning light path.

6. The detection system according to claim 5, characterized in that: The first scanning optical path includes a first switch, and the first switch is used to control whether the first sub-scanning beam can be incident on the first scanning optical path; The second scanning optical path includes a second switch, and the second switch is used to control whether the second sub-scanning light beam can be incident on the second scanning optical path.

7. The detection system according to claim 1, characterized in that The detection system also includes a switching module; The switching module is used to switch the scanning light beam between the first scanning light path and the second scanning light path.

8. The detection system according to any one of claims 1 to 7, characterized in that: The optical power of the detection light source is greater than the optical power of the scanning light source.

9. The detection system according to any one of claims 1 to 7, characterized in that: The first scanning optical path, the second scanning optical path or the detection optical path includes a shaping module, and the shaping module is used to perform light beam shaping processing.

10. The detection system according to any one of claims 1 to 7, characterized in that: The first scanning optical path, the second scanning optical path or the detection optical path includes a polarization module, and the polarization module is used to adjust the polarization state of the light beam.

11. The detection system according to any one of claims 1 to 7, characterized in that: The detection optical path further includes a third switch; When the third switch is in an on state, the third switch is used to enable the detection light beam to perform defect detection on a target defect belonging to a second defect category on the surface of the object to be detected; When the third switch is in the off state, the third switch is used to prevent the detection light beam from performing defect detection on target defects belonging to the first defect category on the surface of the object to be tested; in the defect scanning result obtained by completing the defect scan on the i-th object to be tested, the minimum value of the first light intensity range corresponding to the first defect category is greater than the maximum value of the second light intensity range corresponding to the second defect category.

12. A detection method, characterized in that: Applied to the detection system according to any one of claims 1 to 11, the method comprises: The i-th object to be tested is moved from an initial scanning position to the detection position, and the detection light source is turned on; the initial scanning position is the first scanning position or the second scanning position, and the i-th object to be tested has completed defect scanning by the scanning light beam at the initial scanning position; The (i+1)th object to be tested is located at the target scanning position; the target scanning position is different from the initial scanning position; Turning on the scanning light source and making the scanning light beam incident on the target scanning light path corresponding to the target scanning position; While performing defect detection on the i-th object to be tested using the detection light beam based on the detection light path, performing defect scanning on the (i+1)-th object to be tested using the scanning light beam based on the target scanning light path.

13. The detection method according to claim 12, characterized in that: The scanning light source includes a first scanning light source and a second scanning light source, and turning on the scanning light source and making the scanning light beam incident on the target scanning light path corresponding to the target scanning position includes: When the target scanning position is the first scanning position and the target scanning optical path is the first scanning optical path, turning on the first scanning light source so that the first sub-scanning light beam emitted by the first scanning light source is incident on the first scanning optical path corresponding to the first scanning position; When the target scanning position is the second scanning position and the target scanning optical path is the second scanning optical path, the second scanning light source is turned on so that the second sub-scanning beam emitted by the second scanning light source is incident on the second scanning optical path corresponding to the second scanning position.

14. The detection method according to claim 12, characterized in that: The detection system further includes a switching module; the step of turning on the scanning light source and causing the scanning light beam to be incident on the target scanning light path corresponding to the target scanning position includes: The scanning light source is turned on, and the scanning light beam is made incident on the target scanning light path corresponding to the target scanning position through the switching module.

15. The detection method according to claim 12, characterized in that: The basic optical path further includes a first light splitting module; before performing defect detection on the i-th object to be tested by the detection light beam based on the detection optical path, the method further includes: Determining a first optical power adapted to the i-th object under test; The first light splitting module enables the detection light beam incident on the detection light path to reach the first optical power.

16. The detection method according to claim 12, characterized in that The method further comprises: After completing defect detection on the i-th object to be tested, moving the i-th object to be tested from the testing position to the initial scanning position; At the initial scanning position, the i-th object to be tested is replaced by the i+2-th object to be tested.

17. The detection method according to claim 12, characterized in that: The method further comprises: After completing defect detection on the i-th object to be tested and obtaining a defect detection result, the defect detection result and the defect scanning result obtained by completing defect scanning on the i-th object to be tested are fused to obtain a target detection result of the i-th object to be tested; the target detection result is used to identify the defect information of the i-th object to be tested.

18. The detection method according to any one of claims 12 to 17, characterized in that: The defect scanning result obtained by completing the defect scanning on the i-th object to be tested includes the defect position of each defect on the surface of the i-th object to be tested and the light intensity of each defect; Before performing defect detection on the i-th object to be tested by using the detection light beam based on the detection light path, the method further includes: Determining the defect category to which each defect belongs based on the light intensity; different defect categories correspond to different light intensity ranges; The performing defect detection on the i-th object to be tested by using the detection light beam based on the detection light path includes: Perform defect detection on each position of the surface of the i-th object to be detected by traversing the detection light beam based on the detection light path; When defect detection is performed on a target defect located at a target defect position, the target defect is detected by the detection light beam having a target optical power; the target optical power is determined based on the defect category to which the target defect belongs.

19. The detection method according to claim 18, characterized in that The optical power of the scanning beam is less than the optical power of the detection beam; when the defect category to which the target defect belongs is the first defect category, the target optical power is a first value; when the defect category to which the target defect belongs is the second defect category, the target optical power is a second value; The minimum value of the first light intensity range corresponding to the first defect category is greater than the maximum value of the second light intensity range corresponding to the second defect category; and the first value is smaller than the second value.

20. The detection method according to claim 19, characterized in that The detection optical path further includes a third switch; and the defect detection of the target defect using the detection light beam having the target optical power includes: When the target defect belongs to the second defect category, controlling the third switch to be in an open state, and the detection light beam passes through the third switch to perform defect detection on the target defect; When the target defect belongs to the first defect category, the third switch is controlled to be in an off state, the detection light beam is blocked by the third switch, and defect detection is not performed on the target defect.

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