Detection system and detection method

Abstract

A detection system and a detection method. The detection system comprises a first bright-field detection optical path (101), a second bright-field detection optical path (102), a dark-field detection optical path (103), a first platform (14) and a second platform (19), wherein when the dark-field detection optical path (103) is used for performing dark-field detection on an i-th object to be subjected to detection that is located at a dark-field position (106), and a target optical path is used for performing bright-field detection on an (i+1)-th object to be subjected to detection that is located at a target position, the target optical path being the first bright-field detection optical path (101) or the second bright-field detection optical path (102), and the target position being a first bright-field position (104) or a second bright-field position (105). The bright-field detection optical paths (101, 102) are separated from the dark-field detection optical path (103), such that each optical path performs detection independently, thereby avoiding mutual influence between light sources, and ensuring the detection accuracy of bright-field detection and dark-field detection. In addition, while bright-field detection is performed on one object to be subjected to detection, dark-field detection can be performed on another object to be subjected to detection, that is, parallel detection of two objects to be subjected to detection can be realized, thereby greatly improving the detection efficiency.

Description

A detection system and detection method

[0001] This application claims priority to Chinese Patent Application No. 202510631781.2, filed on May 16, 2025, entitled "A Detection System and Detection Method", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of defect detection, and in particular to a detection system and detection method. Background Technology

[0003] When performing defect inspection on large quantities of test objects, such as wafers, it is necessary to quickly and accurately detect whether the surface of the test object has defects. For a single test object, both dark-field and bright-field inspections are required. In related technologies, the bright-field and dark-field inspection optical paths partially overlap, with the bright-field and dark-field optical axes located at the same position. This causes significant interference between the bright-field beam and the dark-field beam, resulting in lower detection accuracy. Summary of the Invention

[0004] In view of this, the purpose of this application is to provide a detection system and method that ensures the detection accuracy of both bright-field and dark-field detection, and improves detection efficiency. The specific solution is as follows:

[0005] On the one hand, this application provides a detection system, which includes a first bright-field detection optical path, a second bright-field detection optical path, a dark-field detection optical path, a first platform, and a second platform;

[0006] Both the first platform and the second platform are used to carry the object to be tested. The first platform switches between a first bright field position and a dark field position, and the second platform switches between a second bright field position and the dark field position. The first bright field position and the second bright field position are respectively located on the light-emitting side of the first bright field detection optical path and the second bright field detection optical path, and the dark field position is located on the light-emitting side of the dark field detection optical path.

[0007] While the dark field detection optical path is used to perform dark field detection on the i-th test object at the dark field position, the target optical path is used to perform bright field detection on the (i+1)-th test object at the target position; the target optical path is the first bright field detection optical path or the second bright field detection optical path, and the target position is the first bright field position or the second bright field position; i≥1.

[0008] Optionally, the detection system includes a basic optical path, which includes a first light source for emitting a first beam; the dark field detection optical path includes an adjustment module.

[0009] When the adjustment module is in the first state, the dark field detection optical path is used to make the first beam obliquely incident on the object to be tested for dark field detection.

[0010] When the adjustment module is in the second state, the dark field detection optical path is used to make the first beam perpendicularly incident on the object under test for dark field detection.

[0011] Optionally, the detection system includes a first scanning optical path and a second scanning optical path; the first bright field position is located on the light-emitting side of the first scanning optical path, and the second bright field position is located on the light-emitting side of the second scanning optical path;

[0012] While the first bright-field detection optical path is used to perform bright-field detection on the i-th test object located at the first bright-field position, the first scanning optical path is used to scan the i-th test object located at the first bright-field position.

[0013] While the second bright-field detection optical path is used to perform bright-field detection on the i-th test object located at the second bright-field position, the second scanning optical path is used to scan the i-th test object located at the second bright-field position.

[0014] Optionally, the detection system includes a basic optical path and a switching module, wherein the basic optical path includes a first light source and a first beam splitting module;

[0015] The first beam splitting module is used to split the first beam emitted by the first light source into a dark field detection beam incident on the dark field detection optical path, and a target scanning beam incident on the first scanning optical path or the second scanning optical path; the switching module is used to switch the scanning beam between the first scanning optical path and the second scanning optical path.

[0016] Optionally, the detection system includes a basic optical path, the switching module, and a second light source; the basic optical path includes a first light source and a first beam splitting module.

[0017] The first beam splitting module is used to split the first beam emitted by the first light source into a redundant beam and a dark field detection beam incident on the dark field detection optical path.

[0018] The second light source is used to emit a first scanning beam, and the switching module is used to switch the first scanning beam between the first scanning optical path and the second scanning optical path.

[0019] Optionally, the basic optical path further includes a light absorption module located on the side of the first beam splitter from which the redundant beam is emitted, the light absorption module being used to absorb the redundant beam.

[0020] Optionally, the optical power of the first light source is greater than the optical power of the second light source.

[0021] Optionally, the detection system includes a basic optical path, a second light source, and a third light source, wherein the basic optical path includes a first light source and a first beam splitting module;

[0022] The first beam splitting module is used to split the first beam emitted by the first light source into a redundant beam and a dark field detection beam incident on the dark field detection optical path.

[0023] The second light source is used to emit a first scanning beam that is incident on the first scanning optical path;

[0024] The third light source is used to emit a second scanning beam that is incident on the second scanning optical path.

[0025] Optionally, the dark field detection optical path further includes a switch;

[0026] When the switch is in the open state, the switch is used to enable the dark field detection beam to perform dark field detection on the surface of the object under test that belongs to the second defect category;

[0027] When the switch is in the off state, the switch is used to prevent the dark field detection beam from performing dark field detection on the target defect belonging to the first defect category on the surface of the test object; in the defect scanning result obtained after scanning the i-th test object, 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.

[0028] In another aspect, embodiments of this application also provide a detection method applied to a detection system, the method comprising:

[0029] The i-th test object is moved from the initial bright field position to the dark field position; the initial bright field position is either the first bright field position or the second bright field position, and the i-th test object has already completed bright field detection at the initial bright field position;

[0030] Position the (i+1)th test object at the target bright-field position; the target bright-field position is different from the initial bright-field position.

[0031] While performing dark field detection on the i-th test object at the dark field position using the dark field detection beam based on the dark field detection optical path, bright field detection is performed on the (i+1)-th test object at the target position based on the target optical path.

[0032] Optionally, the detection system includes a basic optical path, which includes a first light source for emitting a first light beam; the dark field detection optical path includes an adjustment module; the dark field detection of the i-th object to be tested at the dark field position using the dark field detection beam based on the dark field detection optical path includes:

[0033] Turn on the first light source and use the first beam as the dark field detection beam;

[0034] The adjustment module is in the first state, and based on the dark field detection optical path, the dark field detection beam is obliquely incident on the i-th test object located in the dark field position to perform dark field detection;

[0035] The adjustment module is in the second state, and based on the dark field detection optical path, the dark field detection beam is perpendicularly incident on the i-th test object located in the dark field position to perform dark field detection.

[0036] Optionally, the detection system includes a first scanning optical path and a second scanning optical path; the first bright field position is located on the light-emitting side of the first scanning optical path, and the second bright field position is located on the light-emitting side of the second scanning optical path; the step of performing dark field detection on the i-th test object located at the dark field position using the dark field detection beam based on the dark field detection optical path, and simultaneously performing bright field detection on the (i+1)-th test object located at the target position based on the target optical path, includes:

[0037] While performing dark field detection on the i-th test object at the dark field position based on the dark field detection optical path and the dark field detection beam, performing bright field detection on the (i+1)-th test object at the target position based on the target optical path, and performing scanning processing on the (i+1)-th test object at the target position based on the target scanning optical path and the target scanning beam;

[0038] The target scanning optical path is either a first scanning optical path or a second scanning optical path, the first bright field position is located on the light-emitting side of the first scanning optical path, and the second bright field position is located on the light-emitting side of the second scanning optical path.

[0039] Optionally, the detection system includes a basic optical path and a switching module. The basic optical path includes a first light source and a first beam splitting module. Before performing dark-field detection on the i-th test object at the dark-field position using the dark-field detection beam based on the dark-field detection optical path, performing bright-field detection on the (i+1)-th test object at the target position based on the target optical path, and performing scanning processing on the (i+1)-th test object at the target position using the target scanning beam based on the target scanning optical path, the method further includes:

[0040] When the first light source is turned on, the first beam emitted by the first light source is split into a dark field detection beam incident on the dark field detection optical path and a target scanning beam incident on the target scanning optical path through the switching module and the first beam splitting module.

[0041] Optionally, the detection system includes a basic optical path, the switching module, and a second light source. The basic optical path includes a first light source and a first beam-splitting module. Before performing dark-field detection on the i-th test object at the dark-field position using the dark-field detection beam based on the dark-field detection optical path, performing bright-field detection on the (i+1)-th test object at the target position based on the target optical path, and performing scanning processing on the (i+1)-th test object at the target position using the target scanning beam based on the target scanning optical path, the method further includes:

[0042] The first beam emitted by the first light source is split into a redundant beam and a dark field detection beam incident on the dark field detection optical path by the first beam splitting module.

[0043] Turn on the second light source, and through the switching module, direct the target scanning beam emitted by the second light source toward the target scanning optical path.

[0044] Optionally, the detection system includes a basic optical path, a second light source, and a third light source. The basic optical path includes a first light source and a first beam splitting module. Before performing dark-field detection on the i-th test object at the dark-field position using the dark-field detection beam based on the dark-field detection optical path, performing bright-field detection on the (i+1)-th test object at the target position based on the target optical path, and performing scanning processing on the (i+1)-th test object at the target position using the target scanning beam based on the target scanning optical path, the method further includes:

[0045] The first beam emitted by the first light source is split into a redundant beam and a dark field detection beam incident on the dark field detection optical path by the first beam splitting module.

[0046] The target light source is determined based on the target scanning optical path; the target light source is either the second light source or the third light source.

[0047] Turn on the target light source, use the light beam emitted by the target light source as the target scanning beam, and make the target scanning beam incident on the target scanning optical path.

[0048] Optionally, the defect scanning result obtained by scanning the i-th test object includes the defect location of each defect on the surface of the i-th test object and the light intensity of each defect;

[0049] Before performing dark field detection on the i-th object to be tested at the dark field position using the dark field detection beam through the dark field detection optical path, the method further includes:

[0050] The defect category to which each defect belongs is determined based on the light intensity; different defect categories correspond to different light intensity ranges;

[0051] The step of performing dark field detection on the i-th object to be tested at the dark field position using the dark field detection beam through the dark field detection optical path includes:

[0052] Based on the dark field detection optical path, the dark field detection beam traverses each position on the i-th surface of the object to be tested to perform dark field detection;

[0053] When performing dark-field detection on a target defect located at the target defect position, the target defect is detected by the dark-field detection beam with the target optical power; the target optical power is determined based on the defect category to which the target defect belongs.

[0054] Optionally, the optical power of the target scanning beam is less than the optical power of the dark field 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.

[0055] 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.

[0056] Optionally, the dark field detection optical path further includes a switch; the defect detection of the target defect using the dark field detection beam with the target optical power includes:

[0057] When the target defect belongs to the second defect category, the switch is controlled to be in the open state, and the dark field detection beam passes through the switch to detect the target defect;

[0058] When the target defect belongs to the first defect category, the switch is controlled to be in the off state, the dark field detection beam is blocked by the switch, and the target defect is not detected.

[0059] This application provides a detection system and method. The detection system includes a first bright-field detection optical path, a second bright-field detection optical path, a dark-field detection optical path, a first platform, and a second platform. Both the first and second platforms are used to carry the test object. The first platform switches between a first bright-field position and a dark-field position, and the second platform switches between a second bright-field position and a dark-field position. The first bright-field position and the second bright-field position are located on the light-emitting side of the first and second bright-field detection optical paths, respectively, and the dark-field position is located on the light-emitting side of the dark-field detection optical path. While the dark-field detection optical path is used to perform dark-field detection on the i-th test object at the dark-field position, the target optical path is used to perform bright-field detection on the (i+1)-th test object at the target position. The target optical path is either the first bright-field detection optical path or the second bright-field detection optical path, and the target position is either the first bright-field position or the second bright-field position; i≥1.

[0060] In this embodiment, by separating the bright-field optical axis and the vertical dark-field optical axis, each optical path is detected independently, avoiding mutual interference between beams and ensuring the detection accuracy of both bright-field and dark-field detection. Furthermore, by setting up two bright-field detection optical paths and one dark-field detection optical path, and by setting three positions (first bright-field position, second bright-field position, and dark-field position) to cooperate with two platforms, the first platform can move to the first bright-field position that is not occupied by the second platform. This allows the first and second platforms to start moving simultaneously, greatly improving platform movement efficiency and facilitating the transfer of the test object. While performing bright-field detection on one test object, dark-field detection on another test object can be performed simultaneously, enabling parallel detection of two test objects and significantly improving detection efficiency while completing both bright-field and dark-field detection. Attached Figure Description

[0061] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0062] Figure 1a shows a schematic diagram of a detection system provided in an embodiment of this application;

[0063] Figure 1b shows a schematic diagram of another detection system provided in an embodiment of this application;

[0064] Figure 1c shows a schematic diagram of the layout of bright field and dark field positions provided in an embodiment of this application;

[0065] Figure 2 shows a schematic diagram of a biasing module provided in an embodiment of this application;

[0066] Figure 3 shows a schematic diagram of another detection system provided in an embodiment of this application;

[0067] Figure 4 shows a schematic diagram of another detection system provided in an embodiment of this application;

[0068] Figure 5 shows a schematic diagram of another detection system provided in an embodiment of this application;

[0069] Figure 6 shows a flowchart of a detection method provided in an embodiment of this application;

[0070] Figure 7 shows a schematic diagram of a motion platform provided in an embodiment of this application. Detailed Implementation

[0071] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0072] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0073] For ease of understanding, the detection system and detection method provided in this application will be described in detail below with reference to the accompanying drawings.

[0074] Referring to Figure 1a, which is a schematic diagram of a detection system provided in an embodiment of this application, the detection system includes a first bright field detection optical path 101, a second bright field detection optical path 102, a dark field detection optical path 103, a first platform 14, and a second platform 19.

[0075] The object under test (DUT) is the object that needs to be defect-detected. The DUT can be, for example, a wafer, specifically a patternless wafer. The surface of the DUT typically has various types of defects, such as particles, area defects, slipline defects, cluster defects, scratches, crystal-originated particles (COPs), and large, flat defects. Bright-field and dark-field testing can be used to detect these defects.

[0076] In one possible implementation, in order to comprehensively and accurately detect defects in the test object, a combination of bright field detection and dark field detection can be used for defect detection. Dark field detection is mainly used to detect particles, area defects, slipline defects, cluster defects, scratches, and pits. Bright field detection, due to its high vertical resolution and low horizontal resolution, is mainly used to detect large-area and flat defects such as water stains and residues.

[0077] The first bright-field detection optical path 101 and the second bright-field detection optical path 102 are both optical paths used for bright-field detection of the object under test. Bright-field detection refers to detecting defects in the object under test by using reflected light from the surface of the object under test in a bright environment.

[0078] A bright-field detection optical path may include a bright-field light source, a polarizer, a semi-transparent mirror, a differential interference contrast (DIC) prism, an objective lens, a quarter-wave plate, a tube lens, filters, and a detector. The bright-field light source can be, for example, a laser source or a light-emitting diode (LED) source. The beam emitted by the bright-field source passes through the polarizer to become linearly polarized light. This linearly polarized light then passes through the semi-transparent mirror and is decomposed into two mutually perpendicular beams with a certain phase difference. These two coherent beams with very small splits illuminate the surface of the object under test through the objective lens. Every tiny bump or irregularity on the surface of the object in the field of view causes an optical path difference between these two beams. The returning beams re-converge through the semi-transparent mirror, then pass through the quarter-wave plate to align their vibration directions and cause interference. After passing through the tube lens and filters, the beams are received by the detector. The details on the surface of the object under test become more detailed due to the interference and amplitude changes of the beams, resulting in enhanced contrast. The image output by the detector exhibits a three-dimensional, relief-like effect, thus achieving bright-field detection.

[0079] Referring to Figure 1a, the first bright-field detection optical path 101 includes a first bright-field light source 26a, a first polarizer 27a, a first semi-transparent mirror 28a, a first DIC prism 29a, a first objective lens 30a, a first quarter-wave plate 31a, a first tube lens 32a, a first filter 33a, and a first detector 34a. The second bright-field detection optical path 102 includes a second bright-field light source 26b, a second polarizer 27b, a second semi-transparent mirror 28b, a second DIC prism 29b, a second objective lens 30b, a second quarter-wave plate 31b, a second tube lens 32b, a second filter 33b, and a second detector 34b. Furthermore, if the objective lens has a built-in DIC prism, then a DIC prism is unnecessary, and an objective lens with a built-in DIC prism can be used.

[0080] The dark field detection optical path 103 is used for dark field detection of the object under test. Dark field detection mainly utilizes the scattered light from the surface of the object to detect defects. The dark field detection optical path 103 may include optical elements capable of dark detection, such as a polarizing module, a reflector, and a shaping module. Furthermore, vertical dark field detection is mainly used for detecting defects such as pits and slip lines. These defects typically have a large vertical height difference and a small lateral size, i.e., relatively "steep" defects. Tilted dark field detection is mainly used for detecting protruding defects (such as particles).

[0081] Both the first platform 14 and the second platform 19 are used to support the object under test. For example, the first platform 14 and the second platform 19 can be a stage. The first platform 14 can switch between a first bright field position 104 and a dark field position 106, and the second platform 19 can switch between a second bright field position 105 and a dark field position 106. The first bright field position 104 and the second bright field position 105 are located on the light-emitting side of the first bright field detection optical path 101 and the second bright field detection optical path 102, respectively, while the dark field position 106 is located on the light-emitting side of the dark field detection optical path 103.

[0082] In other words, the first bright-field detection optical path 101 has a first bright-field position 104 on its output side, which is used to place the first platform 14 for bright-field detection of the object under test (DUT) carried on the first platform 14. The second bright-field detection optical path 102 has a second bright-field position 105 on its output side, which is used to place the second platform 19 for bright-field detection of the DUT carried on the second platform 19. Furthermore, the first platform 14 can move between the first bright-field position 104 and the dark-field position 106. That is, after the DUT carried on the first platform 14 completes bright-field detection at the first bright-field position 104, it can follow the first platform 14 to the dark-field position 106 for dark-field detection. Similarly, the second platform 19 can move between the second bright-field position 105 and the dark-field position 106. That is, after the DUT carried on the second platform 19 completes bright-field detection at the second bright-field position 105, it can follow the second platform 19 to the dark-field position 106 for dark-field detection.

[0083] Referring to Figure 1c, three positions are shown: the first bright field position 104, the second bright field position 105, and the dark field position 106. The first platform 14 can move between the first bright field position 104 and the dark field position 106, and the second platform 19 can move between the second bright field position 105 and the dark field position 106.

[0084] While the dark field detection optical path 103 is used to perform dark field detection on the i-th test object located at the dark field position 106, the target optical path is used to perform bright field detection on the (i+1)-th test object located at the target position; the target optical path is either the first bright field detection optical path 101 or the second bright field detection optical path 102, and the target position is either the first bright field position 104 or the second bright field position 105; i≥1.

[0085] Specifically, the i-th and (i+1)-th test objects can be processed simultaneously. Since both the first bright-field detection optical path 101 and the second bright-field detection optical path 102 can achieve bright-field detection, they can both serve as target optical paths. When the target optical path is the first bright-field detection optical path 101, the target position is the first bright-field position 104; when the target optical path is the second bright-field detection optical path 102, the target position is the second bright-field position 105.

[0086] In other words, while performing dark-field detection on the i-th test object at dark-field position 106 through dark-field detection optical path 103, bright-field detection can be performed on the (i+1)-th test object at first bright-field position 104 through first bright-field detection optical path 101. Or, while performing dark-field detection on the i-th test object at dark-field position 106 through dark-field detection optical path 103, bright-field detection can be performed on the (i+1)-th test object at second bright-field position 105 through second bright-field detection optical path 102.

[0087] In short, when the target optical path is the first bright-field detection optical path 101, the (i+1)th test object is placed on the first platform 14 located at the first bright-field position 104, and the ith test object is placed on the second platform 19 located at the dark-field position 106, thus simultaneously detecting both test objects. When the target optical path is the second bright-field detection optical path 102, the (i+1)th test object is placed on the second platform 19 located at the second bright-field position 105, and the ith test object is placed on the first platform 14 located at the dark-field position 106, thus simultaneously detecting both test objects.

[0088] In practical applications, during the testing process, the robotic arm can sequentially transport two test objects to the first bright-field position 104 and the second bright-field position 105 for bright-field testing. The platform that finishes its bright-field testing first will move to the dark-field position 106 to begin dark-field testing. Meanwhile, the other platform will wait at the bright-field position for the test object undergoing dark-field testing to finish. After the dark-field testing is completed, this platform will move to the pick-and-place position, and the test object carried by this platform will be returned to the transport box by the robotic arm. Simultaneously, the other test object will be picked up and placed at the bright-field position to begin bright-field testing. During this process, the other test object that has already completed bright-field testing will undergo dark-field testing.

[0089] In summary, by separating the bright-field detection optical path and the dark-field detection optical path 103, each optical path performs detection independently, avoiding mutual interference between beams and ensuring the detection accuracy of both bright-field and dark-field detection. Furthermore, by setting up two bright-field detection optical paths and one dark-field detection optical path 103, and by setting three positions (first bright-field position 104, second bright-field position 105, and dark-field position 106) to cooperate with the two platforms, a space-for-time trade-off is achieved. The first platform 14 can move to the first bright-field position 104, which will not be occupied by the second platform 19, allowing the first platform 14 and the second platform 19 to move simultaneously. This significantly improves platform movement efficiency and facilitates the transfer of the test object. While performing bright-field detection on one test object, dark-field detection on another can be performed simultaneously, enabling parallel detection of two test objects. This greatly improves detection efficiency, and the combined bright-field and dark-field detection accurately and comprehensively completes the detection of various defects in the test object.

[0090] In one possible implementation, the detection system may include a basic optical path 100, which may include a first light source 1 for emitting a first light beam; the dark field detection optical path 103 may include an adjustment module 22; when the adjustment module 22 is in a first state, the dark field detection optical path 103 is used to obliquely incident the first light beam onto the object under test for dark field detection; when the adjustment module 22 is in a second state, the dark field detection optical path 103 is used to perpendicularly incident the first light beam onto the object under test for dark field detection.

[0091] Specifically, the basic optical path 100 may include a first light source 1, which can be any type of light source, such as a laser, specifically a deep ultraviolet high-power laser. The deep ultraviolet high-power laser can emit continuous or quasi-continuous deep ultraviolet laser beams. To reduce the difficulty of subsequent optical path debugging, the first light source 1 itself can achieve six degrees of freedom adjustment. Furthermore, to reduce the impact of subsequent mechanical movement structure impacts on the first light source 1, vibration isolation pads can be added between the first light source 1 and its supporting structure to ensure that the position of the first light source 1 does not change significantly.

[0092] The light beam emitted by the first light source 1 can be referred to as the first beam, which can be used to incident on the dark field detection optical path 103. When performing dark field detection, vertical dark field detection is more suitable for concave defects such as pits, while tilted dark field detection is more suitable for convex defects such as particles. Therefore, both vertical and tilted dark field detection can be performed on the test object to improve detection accuracy.

[0093] Vertical dark-field inspection uses a top-down, vertical illumination method to project light onto the surface of the object under test. For concave defects, such as slip lines and pits, vertical illumination is more effective. Tilted dark-field inspection, on the other hand, uses an obliquely incident light beam onto the surface of the object under test. This method offers higher accuracy for convex defects.

[0094] The dark field detection optical path 103 may include an adjustment module 22, which can be used to adjust the dark field detection optical path 103, thereby realizing the switching between tilted dark field detection and vertical dark field detection. The adjustment module 22 can be, for example, a movable reflector or a rotatable reflector. By adjusting the adjustment module 22, it can switch between a first state and a second state. When the adjustment module 22 is in the first state, the dark field detection optical path 103 changes, and the first beam can be obliquely incident on the surface of the object to be measured for defect detection. When the adjustment module 22 is in the second state, the first beam can be vertically incident on the surface of the object to be measured for defect detection. Vertical incident can be understood as the angle between the first beam and the surface of the object to be measured being close to 90°.

[0095] Referring to Figure 1a, when the adjustment module 22 is a movable reflector, and the adjustment module 22 is removed from the optical path, it is in the first state, where the first beam is emitted by the first reflector 25 and obliquely incident on the surface of the object under test. When the adjustment module 22 is moved into the optical path, it is in the second state, where the first beam is reflected by the adjustment module 22 and the second reflector 35 and then perpendicularly incident on the surface of the object under test.

[0096] In this way, two dark field tests can be performed on a single object: tilted dark field test and vertical dark field test. This allows for the detection of both concave and convex defects in the object, improving the accuracy and comprehensiveness of the detection.

[0097] In addition, the basic optical path 100 may also include other optical components, such as the slow shutter 2, beam pointing stabilization module 3, beam expanding module 4, and beam adjustment module 40 shown in Figure 1a, which are located along the beam propagation direction. The slow shutter 2 is used to control whether the light emitted by the first light source 1 continues to propagate. When the slow shutter 2 is closed, no beam passes through; when the slow shutter 2 is open, the beam emitted by the first light source 1 can pass through. The beam pointing stabilization module 3 can be used to correct the beam's direction. After the first light source 1 has been used for a period of time, its direction may undergo a slight angular shift. Due to the long optical path of the subsequent optical path, it may no longer meet the requirements of the shaping element by the time it reaches the shaping module. Therefore, a beam pointing stabilization module 3 can be set in the basic optical path 100 to adjust the beam direction. 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 sequentially through the first, second, third, and fourth reflectors before exiting the beam stabilization system. After passing through the second reflector, a portion of the light is transmitted through it and then to the first detector. Similarly, after passing through the fourth reflector, a portion of the light is transmitted through it and then to the second detector. When the light emitted by the laser source becomes unstable and deviates, the light spots on both the first and second detectors also shift. The positions of the light spots transmitted to the first and second detectors can be adjusted to stabilize the output direction of the beam stabilization system. The beam expander module 4 can be used to enlarge the beam spot diameter to meet the requirements of the subsequent shaping module. The beam expander module 4 can be, for example, a one-dimensional beam expander element. This element is designed based on a pair of cylindrical lenses and a pair of deformable prisms, primarily used to adjust the beam size along the narrow axis, ensuring the output beam reaches a predetermined size to meet the needs of subsequent shaping optical elements. The larger the beam size, the narrower the compressible linewidth. The narrow axis is the linewidth direction corresponding to the final line spot, also known as the short side direction of the line spot. Furthermore, the dark-field detection optical path may also include a third reflecting mirror 20, a first polarizing module 21, a fourth reflecting mirror 23, and a third shaping module 24. The beam adjustment module 40 is mainly used to adjust the beam. As an example, in Figures 1a and 1b, the beam adjustment module 40 may include a second half-wave plate 6 and a twelfth reflecting mirror 41 to adjust the beam accordingly. Of course, the beam adjustment module may also include a second half-wave plate 6 and a second polarizing beam splitter (PBS) 7. The second polarizing beam splitter 7 is used to split the beam, allowing a portion of the split beam to be incident on the surface of the object under test. In this case, the beam adjustment module 40 is also the first beam splitter module 5.

[0098] Specifically, since the materials of the objects under test are different, the required beam polarization state may also be different when performing dark field detection or defect scanning. Therefore, a polarization module can be set up to adjust the beam polarization state.

[0099] The polarization module can achieve P / S polarization, left-handed (CL) polarization, right-handed (CR) polarization, and N / A (empty). Referring to Figure 2, which is a schematic diagram of a polarization module provided in an embodiment of this application, the polarization module can include four polarizers to achieve four polarization states. The polarization module can be driven to rotate by a motor to achieve the desired polarization state.

[0100] The shaping module can be a collimated flat-top shaping element, or a freeform surface shaping element. Freeform surface shaping elements can provide single-degree-of-freedom linewidth compression along the narrow side direction. The shaping module can be implemented using diffractive optical elements (DOEs), microlens arrays, prisms, etc. It can also include one-dimensional beam expanders, collimated flat-top shaping elements, freeform surface shapers, or any other suitable shaping module known in the art.

[0101] Furthermore, defects of various types, such as particles, area defects, slipline defects, cluster defects, scratches, and crystal-originated particles (COPs), can be either large or small; these are referred to as defect categories in this invention. For example, a large defect can be one larger than 500 nm. To improve detection accuracy for smaller defects, scattering-based detection requires increasing the laser power of the illumination light. However, high-power illumination can cause large defects to be heated and exploded, exacerbating contamination of the analyte.

[0102] In one possible implementation, the bright field can be used not only to detect defects with large areas and small vertical height differences (such as water stains, residues, and other large, flat defects), but also to detect the aforementioned large-size defects. Based on the bright field detection records of the first bright field position 104 and the second bright field position 105, the location of large-size defects on the surface of the object under test is skipped during dark field detection at the dark field position 106, thus avoiding the high-power light source in the dark field detection position from overwhelming the large-size defects. That is, when performing defect detection on the object under test at the dark field position 106, if the dark field detection beam is incident on the location of a large defect, switch 37 is quickly turned off. After skipping the location of the large defect, switch 37 is turned on again to continue dark field detection of small defects, as shown in Figure 1b. Switch 37 can also be replaced with an acousto-optic modulator (AOM), etc. Furthermore, while performing dark-field detection on the i-th test object at dark-field position 106 via dark-field detection optical path 103, bright-field detection on the (i+1)-th test object at first bright-field position 104 can be performed via first bright-field detection optical path 101. Alternatively, while performing dark-field detection on the i-th test object at dark-field position 106 via dark-field detection optical path 103, bright-field detection on the (i+1)-th test object at second bright-field position 105 can be performed via second bright-field detection optical path 102. That is, this application can perform dark-field detection simultaneously with bright-field detection, executing them in parallel without waiting for the defect scanning process to finish before performing bright-field detection. This greatly improves detection efficiency and, through the combined use of bright-field and dark-field detection, accurately and comprehensively completes the detection of multiple defects in the test object.

[0103] In one possible implementation, the detection system may include a first scanning optical path 201 and a second scanning optical path 202; a first bright field position 104 is located on the light-emitting side of the first scanning optical path 201, and a second bright field position 105 is located on the light-emitting side of the second scanning optical path 202; while the first bright field detection optical path 101 is used to perform bright field detection on the i-th analyte located at the first bright field position 104, the first scanning optical path 201 is used to perform scanning processing on the i-th analyte located at the first bright field position 104; while the second bright field detection optical path 102 is used to perform bright field detection on the i-th analyte located at the second bright field position 105, the second scanning optical path 202 is used to perform scanning processing on the i-th analyte located at the second bright field position 105.

[0104] When inspecting an object, if the light power reaching the surface of the object is too high, it can easily expose large defects scattered on the surface, thus contaminating the object. Therefore, to avoid exposing defects, a lower light power can be used to scan for defects before performing dark-field inspection, so as to record the location of large defects on the surface of the object.

[0105] Specifically, the detection system may also include two scanning optical paths, namely a first scanning optical path 201 and a second scanning optical path 202. The scanning optical paths are mainly used for scanning defects. The scanning optical paths may include a shaping module and at least one reflector to improve the beam shape and propagation direction. The optical power of the beam in the scanning optical path can be relatively low to avoid beam bursts. When the first platform 14 carrying the i-th test object is located at the first bright field position 104, the first scanning optical path 201 can scan the test object. If the second platform 19 carrying the i-th test object is located at the second bright field position 105, the second scanning optical path 202 can scan the test object.

[0106] Referring to Figure 3, the first platform 14 carries the test object, namely wafer I. The first platform 14 is located at the first bright field position 104. At this time, the detection system can scan wafer I through the first scanning optical path 201, and at the same time, it can also perform bright field detection through the first bright field detection optical path 101. After completing the scanning and bright field detection, dark field detection is then performed.

[0107] Similarly, if the second platform 19 carries an object to be tested, and the second platform 19 is located at the second bright-field position 105, the detection system can scan the object to be tested through the second scanning optical path 202. Simultaneously, bright-field detection can be performed through the second bright-field detection optical path 102. Furthermore, the scanning process can detect slightly larger defects that bright-field detection cannot detect. For example, while bright-field detection can detect defects as small as a few micrometers, the scanning process can detect defects as small as a few hundred nanometers, achieving comprehensive defect detection.

[0108] In addition, to avoid mutual interference between scanning processing and bright field detection, the light beams used for scanning processing and bright field detection can have different wavelengths. A filter corresponding to the light wavelength is set at the detector end used for scanning processing, and a filter is also set at the detector end used for bright field detection, so that the detector can only receive light within its own wavelength range, thus avoiding interference between the bright field detection beam and the bright field detection results.

[0109] The first and second scanning optical paths can be tilted, low-power dark-field scanning optical paths. When performing both bright-field DIC detection and tilted, low-power dark-field scanning on the same bright-field object, the two illumination spots generated by the two optical paths at the bright-field position can be aligned, meaning the two illumination spots can overlap. This saves scanning time compared to non-overlapping illumination spots. Especially when the platform moves the object, dark-field scanning and bright-field DIC detection can be performed simultaneously at various positions on the object, improving detection efficiency.

[0110] In addition, referring to Figure 3, the detection system may also include several mirrors and other optical elements, such as the fifth mirror 8, the second polarizing module 9, and the target mirror 10. The first scanning optical path may also include the first shaping module 11, the seventh mirror 12, and the eighth mirror 13. The second scanning optical path may also include the ninth mirror 15, the second shaping module 16, the tenth mirror 17, and the eleventh mirror 18.

[0111] In this way, by performing defect scanning on the test object before dark-field inspection, the location of each defect can be identified. This allows for appropriate processing of defects of different sizes during subsequent dark-field inspection. For example, for large defects, the location of large defects can be skipped during dark-field inspection, improving detection accuracy. Furthermore, this application performs defect scanning simultaneously with bright-field inspection, executing the processes in parallel without waiting for the defect scanning to complete before proceeding with bright-field inspection, significantly improving detection efficiency.

[0112] In one possible implementation, the detection system may include a basic optical path 100 and a switching module. The basic optical path 100 includes a first light source 1 and a first beam splitting module 5. The first beam splitting module 5 is used to split the first beam emitted by the first light source 1 into a dark field detection beam incident on the dark field detection optical path 103 and a target scanning beam incident on the first scanning optical path 201 or the second scanning optical path 202. The switching module is used to switch the scanning beam between the first scanning optical path 201 and the second scanning optical path 202.

[0113] Specifically, to simplify the optical path structure, a first light source 1 can be set in the detection system, which can be used to illuminate the scanning process and the dark field detection. Referring to Figure 4, the basic optical path 100 includes a first light source 1 and a first beam splitting module 5, which can be a beam splitting prism.

[0114] The first light beam emitted by the first light source 1 is split into two beams after passing through the first beam splitting module 5: a dark field detection beam and a target scanning beam. The dark field detection beam can be incident on the dark field detection optical path 103 for dark field detection, while the target scanning beam can be incident on the scanning optical path for scanning processing. This scanning optical path can be either a first scanning optical path 201 or a second scanning optical path 202.

[0115] The detection system may also include a switching module, which is used to switch the scanning optical path, that is, to allow the target scanning beam to be incident on the first scanning optical path 201, or to allow the target scanning beam to be incident on the second scanning optical path 202. The switching module can be the target reflector 10. Referring to Figure 4, when the target reflector 10 is in the optical path, the target scanning beam can be incident on the first scanning optical path 201, and when the target reflector 10 is not in the optical path, the target scanning beam can be incident on the second scanning optical path 202.

[0116] In summary, by sharing the same light source, namely the first light source 1, for defect scanning and dark field detection, optical path costs can be saved, and the switching of scanning optical paths can be achieved accurately and efficiently through the switching module.

[0117] In one possible implementation, the detection system may include a basic optical path 100, a switching module, and a second light source 26. The basic optical path 100 includes a first light source 1 and a first beam splitting module 5. The first beam splitting module 5 is used to split the first beam emitted by the first light source 1 into a redundant beam and a dark field detection beam incident on the dark field detection optical path 103. The second light source 26 is used to emit a first scanning beam, and the switching module is used to switch the first scanning beam between the first scanning optical path 201 and the second scanning optical path 202.

[0118] Specifically, to achieve more accurate defect scanning, an independent light source, namely a second light source 26, can be configured for the scanning optical path. The beam emitted by the second light source 26 can be referred to as the first scanning beam. The first scanning beam can be incident on either the first scanning optical path 201 or the second scanning optical path 202. Under the action of the switching module, it is possible to control which scanning optical path the first scanning beam is incident on.

[0119] At this time, the first beam emitted by the first light source 1 is split into a redundant beam and a dark field detection beam after passing through the first beam splitting module 5. The dark field detection beam can continue to be incident on the dark field detection optical path 103.

[0120] In one possible implementation, the first beam splitting module 5 may include a second half-wave plate 6 and a second polarizing beam splitter (PBS) 7. The optical power of the detection beam can be adjusted by rotating the second half-wave plate 6. This method is simple to operate and can achieve precise adjustment of the optical power.

[0121] Referring to Figure 4, the detection system includes four light sources, namely a first light source 1, a second light source 26, a first bright field light source 26a, and a second bright field light source 26b. The first light source 1 is used to provide a dark field detection beam for the dark field detection optical path 103, the second light source 26 is used to provide a scanning beam for the scanning optical path, and the two bright field light sources are used to provide bright field beams for their respective bright field detection optical paths.

[0122] In summary, by providing an independent light source for the scanning optical path, the optical power adjustment of the scanning beam is more flexible and not limited by the first light source 1, and the optical power requirement of the first light source 1 is reduced. The first light source 1 can be selected from light sources with lower optical power, thus reducing the cost of the light source.

[0123] In one possible implementation, the basic optical path 100 may further include an optical absorption module located on the side of the redundant beam emitted by the first beam splitter 5, the optical absorption module being used to absorb the redundant beam.

[0124] Since the dark field detection optical path 103 only needs to use the dark field detection beam for dark field detection, the other part of the beam emitted after the first beam splitter 5, i.e., the redundant beam, does not need to be incident on the dark field detection optical path 103. To avoid interference from the redundant beam to the dark field detection, a light absorption module 27 can be set up. The redundant beam is absorbed by the light absorption module 27 after it is emitted from the first beam splitter 5, thereby avoiding light leakage and adverse effects on the dark field detection optical path 103. It can also retain the variable attenuation function of the dark field detection optical path 103, i.e., the optical power is adjustable. As an example, the light absorption module 27 can be an optical trap.

[0125] In summary, by setting up the light absorption module 27, stray light after beam splitting, i.e. redundant beam, can be absorbed to avoid affecting the dark field detection optical path 103. In addition, the light power attenuation adjustment of the dark field detection beam can be realized, which can help adjust the dark field detection beam to a suitable light power.

[0126] In one possible implementation, the optical power of the first light source 1 is greater than the optical power of the second light source 26.

[0127] Specifically, the second light source 26 is mainly used to provide a scanning beam for the scanning optical path, primarily for detecting large-sized defects and recording their locations. To avoid accidentally exploding large-sized defects during scanning, the optical power of the second light source 26 can be set to be lower than that of the first light source 1. In this way, by using lower optical power for defect scanning and higher optical power for dark-field detection, various defects can be detected, while avoiding the accidental exploding of large-sized defects.

[0128] In one possible implementation, the detection system may include a basic optical path 100, a second light source 26, and a third light source 36. The basic optical path 100 includes a first light source 1 and a first beam splitting module 5. The first beam splitting module 5 is used to split the first beam emitted by the first light source 1 into a redundant beam and a dark field detection beam incident on the dark field detection optical path 103. The second light source 26 is used to emit a first scanning beam incident on the first scanning optical path 201. The third light source 36 is used to emit a second scanning beam incident on the second scanning optical path 202.

[0129] To further enhance the flexibility of beam power adjustment, an independent light source can be provided for each scanning optical path. Specifically, a second light source 26 is provided for the first scanning optical path 201, and a third light source 36 is provided for the second scanning optical path 202. Referring to Figure 5, the second light source 26 emits the first scanning beam, which can be incident on the surface of the object under test after passing through the first scanning optical path 201. The third light source 36 is used to emit the second scanning beam, which can be incident on the surface of the object under test after passing through the second scanning optical path 202.

[0130] In this way, an independent light source is set up for each optical path, and the light power of the beam in each optical path can be adjusted independently without affecting each other. The light power adjustment is more convenient and flexible, and the defect scanning, bright field detection and dark field detection will be more accurate.

[0131] In one possible implementation, the dark field detection optical path 103 further includes a switch 37; when the switch 37 is in the open state, the switch 37 is used to enable the dark field detection beam to perform dark field detection on the surface of the object to be tested that belongs to the second defect category; when the switch 37 is in the closed state, the switch 37 is used to enable the dark field detection beam to not perform dark field detection on the surface of the object to be tested that belongs to the first defect category; in the defect scanning result obtained after scanning 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.

[0132] Specifically, switch 37 can be located in the dark field detection optical path 103 to control whether the dark field detection beam can be incident on the surface of the object under test. Since large-size defects correspond to higher light intensity and small-size defects correspond to lower light intensity during defect scanning, the first defect category represents large-size defects, such as large particle defects, and the second defect category represents small-size defects, such as small particle defects.

[0133] When the target defect belongs to the second defect category, it indicates that the target defect is a small-sized defect. Since dark field detection is mainly used to detect this type of defect, the switch 37 can be controlled to be in the open state so that the dark field detection beam can pass through the switch 37 to detect the target defect on the surface of the object to be tested.

[0134] When the target defect belongs to the first defect category, it indicates that the target defect is a large-size defect. Since it has already been detected by defect scanning, and in order to avoid the explosion of the scan, there is no need to perform dark field detection again. Therefore, switch 37 can be controlled to be in the closed state. The dark field detection beam is blocked by switch 37 and cannot continue to propagate backward, so no defect detection is performed on the target defect.

[0135] In other words, when performing defect detection on the object under test, if the dark field detection beam is incident on the location of a large defect, the switch 37 is quickly turned off. After the location of the large defect is skipped, the switch 37 is turned on again to continue dark field detection of small defects.

[0136] In summary, by setting switch 37 in the dark field detection optical path 103, it is possible to conveniently perform dark field detection on large and small defects using different optical powers by turning switch 37 off. This is easy to operate, low in cost, and can minimize the risk of large defects being blown up.

[0137] Referring to Figure 6, which is a flowchart of a detection method provided in an embodiment of this application, the method is applied to a detection system and may include the following steps.

[0138] S101, move the i-th test object from the initial bright field position to the dark field position 106.

[0139] The initial brightfield position can be understood as the position where the i-th test object undergoes brightfield detection. The initial brightfield position can be either the first brightfield position 104 or the second brightfield position 105. That is, when the i-th test object is located on the first platform 14, the first brightfield position 104 of the first platform 14 is the initial brightfield position. If the test object is located on the second platform 19, the second brightfield position 105 of the second platform 19 is the initial brightfield position. The i-th test object has already completed brightfield detection at the initial brightfield position.

[0140] In other words, for the i-th test object, after it completes bright field detection through the bright field detection optical path at the initial bright field position, it can be moved from the initial bright field position to the dark field position 106, which means moving the platform carrying the i-th test object from the bright field position to the dark field position 106.

[0141] S102, so that the (i+1)th test object is located at the target bright field position.

[0142] Specifically, the next test object, i.e., the (i+1)th test object, can be placed on a platform located at another bright field position. The target bright field position is different from the initial bright field position. When the initial bright field position is the first bright field position 104, the target bright field position is the second bright field position 105. When the initial bright field position is the second bright field position 105, the target bright field position is the first bright field position 104.

[0143] S103, while performing dark field detection on the i-th test object at the dark field position 106 using the dark field detection beam based on the dark field detection optical path 103, performing bright field detection on the (i+1)-th test object at the target position based on the target optical path.

[0144] Specifically, at this time, the i-th test object is located in the dark field position 106, and the (i+1)-th test object is located in the target bright field position. Therefore, these two test objects can be processed simultaneously. That is, the dark field detection beam is incident on the surface of the i-th test object through the dark field detection optical path 103 to perform dark field detection, while at the same time, the target optical path can perform bright field detection on the (i+1)-th test object.

[0145] The target optical path can be either the first bright field detection optical path 101 or the second bright field detection optical path 102. When the initial bright field position is the first bright field position 104, the target optical path is the second bright field detection optical path 102; when the initial bright field position is the second bright field position 105, the target optical path is the first bright field detection optical path 101.

[0146] In summary, by separating the bright-field optical axis and the vertical dark-field optical axis, each optical path can perform independent detection, avoiding mutual interference between light sources and ensuring the detection accuracy of both bright-field and dark-field detection. Furthermore, by setting up two bright-field detection optical paths and one dark-field detection optical path 103, and by setting three positions (first bright-field position 104, second bright-field position 105, and dark-field position 106) to cooperate with the two platforms, the first platform 14 can be moved to the first bright-field position 104, which will not be occupied by the second platform 19. This allows the first platform 14 and the second platform 19 to move simultaneously, greatly improving platform movement efficiency and facilitating the transfer of the test object. While performing bright-field detection on one test object, dark-field detection on another can be performed simultaneously, enabling parallel detection of two test objects. This significantly improves detection efficiency, and through the combined bright-field and dark-field detection, accurate and comprehensive detection of various defects in the test object can be achieved.

[0147] In one possible implementation, the detection system may include a basic optical path 100, which includes a first light source 1 for emitting a first beam, and a dark field detection optical path 103 including an adjustment module 22; S103 performs dark field detection on the i-th test object at the dark field position 106 based on the dark field detection optical path 103 and the dark field detection beam, which may specifically include S1031-S1033.

[0148] S1031, turn on the first light source 1 and use the first beam as the dark field detection beam.

[0149] S1032, the adjustment module 22 is in the first state, and based on the dark field detection optical path 103, the dark field detection beam is obliquely incident on the i-th test object in the dark field position 106 to perform dark field detection.

[0150] S1033, the adjustment module 22 is in the second state, and based on the dark field detection optical path 103, the dark field detection beam is perpendicularly incident on the i-th test object at the dark field position 106 to perform dark field detection.

[0151] Specifically, referring to Figure 1a, the first light source 1 can be turned on, and the first beam emitted by the first light source 1 can be used as the dark field detection beam. The adjustment module 22 is then positioned in the first state and the second state, respectively, so that the dark field detection beam can be obliquely incident on the surface of the object under test and perpendicularly incident on the surface of the object under test. The execution order of S1032 and S1033 is not limited; S1032 can be executed first and then S1033, or vice versa.

[0152] As an example, when performing dark-field detection on the i-th test object, the dark-field detection beam can be incident at an angle onto the surface of the test object, traversing all positions on the surface to achieve tilted dark-field detection at each position. Then, the dark-field detection beam can be incident perpendicularly onto the surface of the test object, traversing all positions to perform perpendicular dark-field detection. In this way, both protruding and concave defects on the surface of the test object can be accurately detected.

[0153] In one possible implementation, the detection system includes a first scanning optical path 201 and a second scanning optical path 202; a first bright field position 104 is located on the light-emitting side of the first scanning optical path 201, and a second bright field position 105 is located on the light-emitting side of the second scanning optical path 202; S103 performs dark field detection on the i-th test object at the dark field position 106 based on the dark field detection optical path 103 and the dark field detection beam, while simultaneously performing bright field detection on the (i+1)-th test object at the target position based on the target optical path, specifically including S1034.

[0154] S1034, while performing dark field detection on the i-th test object at the dark field position 106 using the dark field detection beam based on the dark field detection optical path 103, performing bright field detection on the (i+1)-th test object at the target position based on the target optical path, and performing scanning processing on the (i+1)-th test object at the target position using the target scanning beam based on the target scanning optical path.

[0155] Specifically, two scanning optical paths can be added to the detection system, namely the first scanning optical path 201 and the second scanning optical path 202. The scanning optical path is mainly used to scan and process defects. The scanning optical path may include a shaping module and at least one reflector to improve the beam shape and propagation direction. The optical power of the beam in the scanning optical path can be relatively small to avoid scanning explosion.

[0156] The target scanning optical path can be either the first scanning optical path 201 or the second scanning optical path 202. The first bright field position 104 is located on the light-emitting side of the first scanning optical path 201, and the second bright field position 105 is located on the light-emitting side of the second scanning optical path 202. That is to say, the target scanning optical path can be either of the two scanning optical paths. When the target position is the first bright field position 104, the target scanning optical path is the first scanning optical path 201; when the target position is the second bright field position 105, the target scanning optical path is the second scanning optical path 202.

[0157] Referring to Figure 4, the i-th test object, wafer II, is placed on the second platform 19, which is located at the dark field position 106. The (i+1)-th test object, wafer III, is placed on the first platform 14, which is located at the first bright field position 104. The target position is the first bright field position 104, the target optical path is the first bright field detection optical path 101, and the target scanning optical path is the first scanning optical path 201. While performing dark field detection on wafer II, wafer III can be scanned via the first scanning optical path 201, and wafer III can also be scanned via the first bright field detection optical path 101.

[0158] In this way, by performing defect scanning on the test object before dark-field inspection, the location of each defect can be identified. This allows for appropriate processing of defects of different sizes during subsequent dark-field inspection. For example, for large defects, the location of large defects can be skipped during dark-field inspection, improving detection accuracy. Furthermore, this application performs defect scanning simultaneously with bright-field inspection, executing the processes in parallel without waiting for the defect scanning to complete before proceeding with bright-field inspection, significantly improving detection efficiency.

[0159] In summary, by separating the bright-field optical axis and the vertical dark-field optical axis, each optical path performs independent detection, avoiding mutual interference between light sources and ensuring the detection accuracy of both bright-field and dark-field detection. Furthermore, by setting up two bright-field detection optical paths and one dark-field detection optical path 103, and by setting three positions (first bright-field position 104, second bright-field position 105, and dark-field position 106) to cooperate with the two platforms, the first platform 14 can move to the first bright-field position 104, which will not be occupied by the second platform 19. This allows the first platform 14 and the second platform 19 to move simultaneously, greatly improving platform movement efficiency and facilitating the transfer of the test object. While performing bright-field detection and scanning processing on one test object at one bright-field position, dark-field detection can be performed on another test object at the dark-field position, enabling parallel detection of two test objects. This significantly improves detection efficiency and, through the combined bright-field, scanning, and dark-field detection, accurately and comprehensively completes the detection of various defects in the test object, while avoiding the situation where large defects are detected and exposed.

[0160] Furthermore, for a single test object, after completing bright-field detection, dark-field detection, and scanning processing, the corresponding results can be fused to obtain the final detection result. Since the processing time after image acquisition is positively correlated with the number of defects and the surface roughness of the test object, the more particles and the rougher the surface, the longer the algorithm takes, affecting machine productivity. Therefore, the software architecture can be reconfigured to allow the dual-station movement time and image processing time to be completely parallel. Additionally, each test object's bright-field detection result, dark-field detection result, and defect scanning result can be uniquely labeled for differentiation, thereby maximizing the detection productivity of the test object while ensuring the machine's detection sensitivity.

[0161] In one possible implementation, the detection system may include a basic optical path 100 and a switching module. The basic optical path 100 may include a first light source 1 and a first beam splitting module 5. S1034 may also include S201 before the target optical path performs bright field detection on the i-th test object at the target position 106 through the dark field detection beam based on the dark field detection optical path 103, and before the target optical path performs bright field detection on the i+1-th test object at the target position through the target scanning beam, and before the target scanning optical path performs scanning processing on the i+1-th test object at the target position through the target scanning beam.

[0162] S201, turn on the first light source 1, and through the switching module and the first beam splitting module 5, make the first beam emitted by the first light source 1 split into a dark field detection beam incident on the dark field detection optical path 103 and a target scanning beam incident on the target scanning optical path.

[0163] Specifically, when the dark field detection optical path 103 and the scanning optical path share the same light source, namely the first light source 1, the first light source 1 can be turned on during detection. The first beam emitted by the first light source 1 passes through the first beam splitting module 5 to obtain the dark field detection beam and the target scanning beam. The dark field detection beam continues to propagate into the dark field detection optical path 103, and the target scanning beam propagates into the target scanning optical path.

[0164] In summary, by sharing the same light source, namely the first light source 1, for defect scanning and dark field detection, optical path costs can be saved, and the switching of scanning optical paths can be achieved accurately and efficiently through the switching module.

[0165] In one possible implementation, the detection system may include a basic optical path 100, a switching module, and a second light source 26. The basic optical path 100 may include a first light source 1 and a first beam splitting module 5. S1034 Before performing dark field detection on the i-th test object at the dark field position 106 based on the dark field detection optical path 103 and the bright field detection on the (i+1)-th test object at the target position based on the target optical path, and before performing scanning processing on the (i+1)-th test object at the target position based on the target scanning optical path and the target scanning optical path, the method further includes S202-S203.

[0166] S202, through the first beam splitting module 5, the first beam emitted by the first light source 1 is split into a redundant beam and a dark field detection beam incident on the dark field detection optical path 103.

[0167] S203, turn on the second light source 26, and through the switching module, make the target scanning beam emitted by the second light source 26 incident on the target scanning optical path.

[0168] Specifically, independent light sources can be provided for both the dark field detection optical path 103 and the scanning optical path. When performing defect detection, the first light source 1 can be turned on, and the first beam emitted by the first light source 1 is split into a redundant beam and a dark field detection beam after passing through the first beam splitting module 5.

[0169] The second light source 26 is turned on, and the first scanning beam emitted by the second light source 26 is used as the target scanning beam. Furthermore, the target scanning beam is directed into the target scanning optical path via a switching module, thereby achieving parallel execution of scanning processing and dark field detection. The order of steps S202 and S203 is not limited; they can be executed simultaneously.

[0170] In summary, by providing an independent light source for the scanning optical path, the optical power adjustment of the scanning beam is more flexible and not limited by the first light source 1, and the optical power requirement of the first light source 1 is reduced. The first light source 1 can be selected from light sources with lower optical power, thus reducing the cost of the light source.

[0171] In one possible implementation, the detection system may include a basic optical path 100, a second light source 26, and a third light source 36. The basic optical path 100 may include a first light source 1 and a first beam splitting module 5. In step S1034, while performing dark field detection on the i-th test object at the dark field position 106 using the dark field detection beam based on the dark field detection optical path 103, performing bright field detection on the (i+1)-th test object at the target position based on the target optical path, and performing scanning processing on the (i+1)-th test object at the target position using the target scanning beam based on the target scanning optical path, the method may also include steps S204-S206.

[0172] S204, through the first beam splitting module 5, the first beam emitted by the first light source 1 is split into a redundant beam and a dark field detection beam incident on the dark field detection optical path 103.

[0173] S205, determine the target light source based on the target scanning optical path.

[0174] S206, turn on the target light source, use the light beam emitted by the target light source as the target scanning beam, and make the target scanning beam incident on the target scanning optical path.

[0175] To further improve the freedom of beam power adjustment, an independent light source can be set for each scanning optical path, namely, a second light source 26 is set for the first scanning optical path 201, and a third light source 36 is set for the second scanning optical path 202. The target light source can be either the second light source 26 or the third light source 36.

[0176] The first light source 1 is turned on, and the first beam emitted by the first light source 1 is divided into a redundant beam and a dark field detection beam by the first beam splitting module 5. When the target scanning optical path is the first scanning optical path 201, the target light source is the second light source 26 corresponding to the first scanning optical path 201; when the target scanning optical path is the second scanning optical path 202, the target light source is the third light source 36 corresponding to the second scanning optical path 202. The target light source is turned on, and the beam emitted by the target light source is used as the target scanning beam, so that the target scanning beam is incident on the target scanning optical path.

[0177] Referring to Figure 5, wafer III is located on the first platform 14, the target scanning optical path is the first scanning optical path 201, and the target light source is the second light source 26. The first light source 1 and the second light source 26 are turned on. The beam emitted by the first light source 1 is used to perform dark field detection on wafer II, and the beam emitted by the second light source 26 is used to perform scanning processing on wafer III.

[0178] In this way, an independent light source is set up for each optical path, and the light power of the beam in each optical path can be adjusted independently without affecting each other. The light power adjustment is more convenient and flexible, and the defect scanning, bright field detection and dark field detection will be more accurate.

[0179] In one possible implementation, the defect scanning result obtained after scanning the i-th test object includes the defect location of each defect on the surface of the i-th test object and the light intensity of each defect.

[0180] Before S103 performs dark field detection on the i-th test object at dark field position 106 using the dark field detection beam through the dark field detection optical path 103, the method further includes S301, determining the defect category of each defect based on the light intensity; different defect categories correspond to different light intensity ranges; S104 performs dark field detection on the i-th test object at dark field position 106 using the dark field detection beam through the dark field detection optical path 103, which can be specifically S401-S402.

[0181] S401, based on the dark field detection optical path 103, the dark field detection beam traverses each position on the surface of the i-th object to be tested to perform dark field detection.

[0182] S402, when performing dark field detection on a target defect located at the target defect position, the target defect is detected by a dark field detection beam with target optical power; the target optical power is determined based on the defect category to which the target defect belongs.

[0183] Specifically, the defect scanning result of the i-th test object can include the defect location of each defect and the light intensity corresponding to each defect. In other words, when performing defect scanning, the detection system can record the location of each defect and the light intensity at that defect.

[0184] Defect categories can be based on defect size, such as large defects and small defects. Defect types can be categorized as particles, surface defects, slip line defects, etc. Different categories of the same type of defect (large defects, small defects) correspond to different light intensity ranges. For example, defect category one corresponds to a light intensity range of X1 to X2, while defect category two corresponds to a light intensity range of X3 to X4. For a given defect, the light intensity at that defect location is compared to the light intensity range to determine the defect category. For example, a large defect can be a defect larger than 500 nm.

[0185] In S103, when performing defect detection, corresponding processing can be performed based on different defect categories. The dark field detection beam can traverse various positions on the surface of the i-th test object. For example, the platform carrying the i-th test object can move the test object, thereby illuminating different positions of the test object with the dark field detection beam, thus achieving traversal of each defect.

[0186] The target defect can be any defect on the object under test (DUT). The target defect location can be understood as the specific position of the target defect on the surface of the DUT, which can be represented 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 dark field detection beam when performing dark field detection on the target defect. Different defect categories correspond to different optical powers of the dark field detection beam.

[0187] In summary, by selecting the appropriate optical power of the dark field detection beam for different types of defects, targeted detection of various defects can be achieved, thereby improving the accuracy of the final detection results.

[0188] In one possible implementation, the optical power of the target scanning beam is less than the optical power of the dark field 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; 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.

[0189] Specifically, the optical power of the target scanning beam required for defect scanning can be less than the optical power of the dark-field detection beam used for defect detection. Defect scanning primarily uses a target scanning beam with lower optical power to identify large-sized defects, avoiding the possibility of defects being blown up due to excessive optical power, such as large particle defects being blown up, thus contaminating the test object. In dark-field detection, a dark-field detection beam with higher optical power is primarily used to identify small-sized defects.

[0190] The first defect category can be any defect category. The light intensity range corresponding to the first defect category can be denoted as the first light intensity range. The light intensity range corresponding to the second defect category can be denoted 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.

[0191] Because large-sized defects correspond to higher light intensity and small-sized defects correspond to lower light intensity during defect scanning, 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.

[0192] To avoid damaging large defects during defect detection, a smaller initial optical power can be used when traversing to the first defect category (large defects). This lower power prevents damage to the large defects and contamination of the test object. When traversing to the second defect category (small defects), a larger initial optical power can be used to ensure accurate detection of smaller defects.

[0193] In practical applications, when the target defect category is the first defect category, using a smaller first value for the target optical power can mean either reducing the target optical power or setting the target optical power to 0, i.e., not detecting large-sized defects. Reducing the target optical power can be achieved by switching the acousto-optic modulator (AOM) on and off to decrease the optical power. Setting the target optical power to 0 can also prevent the dark-field detection beam from incident on the location of the large-sized defect.

[0194] In summary, by using appropriate optical power to detect large and small defects during dark field inspection, it is possible to avoid the situation of large defects being blown out and to achieve accurate detection of small defects.

[0195] In one possible implementation, the dark field detection optical path 103 further includes a switch; S402 performs defect detection on the target defect using a dark field detection beam with target optical power. Specifically, when the target defect belongs to the second defect category, the control switch is in the open state, and the dark field detection beam passes through the switch to perform defect detection on the target defect; when the target defect belongs to the first defect category, the control switch is in the closed state, and the dark field detection beam is blocked by the switch, so no defect detection is performed on the target defect.

[0196] Specifically, switch 37 can be located in the dark field detection optical path 103 to control whether the dark field detection beam can be incident on the surface of the object under test. When the target defect belongs to the second defect category, it means that the target defect is a small-sized defect. Since dark field detection is mainly for detecting this type of defect, switch 37 can be controlled to be in the open state so that the dark field detection beam can pass through switch 37 to detect the target defect on the surface of the object under test.

[0197] When the target defect belongs to the first defect category, it indicates that the target defect is a large-size defect. Since it has already been detected by defect scanning, and in order to avoid the explosion of the scan, there is no need to perform dark field detection again. Therefore, switch 37 can be controlled to be in the closed state. The dark field detection beam is blocked by switch 37 and cannot continue to propagate backward, so no defect detection is performed on the target defect.

[0198] In other words, when performing defect detection on the object under test, if the dark field detection beam is incident on the location of a large defect, the switch 37 is quickly turned off. After the location of the large defect is skipped, the switch 37 is turned on again to continue dark field detection of small defects.

[0199] In summary, by setting switch 37 in the dark field detection optical path 103, it is possible to conveniently perform dark field detection on large and small defects using different optical powers by turning switch 37 off. This is easy to operate, low in cost, and can minimize the risk of large defects being blown up.

[0200] In this application, the scanning optical path can be a bright-field scanning optical path, in which case the scanning optical path performs defect scanning using bright-field processing; or it can be a tilted dark-field scanning optical path, in which case the scanning optical path performs defect scanning using tilted dark-field processing. Bright-field processing images defects using reflected light from the surface of the object under test (DUT), while dark-field processing images defects using scattered light from the DUT surface. Tilted dark-field processing involves incident light incident at an angle rather than perpendicularly onto the DUT surface, and the collection channel is also tilted rather than along the normal direction of the DUT surface; that is, both the incident light and the collection channel are non-directional. Dark-field detection optical paths can include normal and / or tilted dark-field processing, i.e., incident light is incident perpendicularly and / or at an angle onto the DUT surface, and the collection channel is tilted and / or normal to collect the scattered light from the DUT. The optical paths for bright-field and dark-field processing will be described in detail below.

[0201] In one possible implementation, during bright-field or dark-field processing, one or more collection channels can be positioned above the bright-field or dark-field position. For example, a collection channel can be positioned directly above or diagonally above. When the scanning optical path is an inclined dark-field scanning optical path, the collection channel is positioned diagonally above, rather than directly above, the bright-field position. The collection channel is used to receive the light beam from the upper surface of the object under test for imaging. One or more detectors are correspondingly located within the collection channel, and these detectors are used to achieve imaging based on the light beam.

[0202] The detector may include any suitable detector known in the art, such as discrete photomultiplier tube (PMT), charge-coupled device (CCD), time delay integration (TDI), complementary metal oxide semiconductor (CMOS) sensor, PMT array, electron bombardment CCD (EB-CCD), electron-multiplying CCD (EM-CCD), enhancement-mode photodiode or avalanche photodiode (APD) array.

[0203] In one possible implementation, during dark field processing (e.g., tilted dark field scanning optical path or dark field detection optical path), a detection system can be positioned at a suitable location diagonally above or below the bright field position or dark field 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 only one detection system, it can collect and image the scattered light from the upper surface of the object under test, thereby achieving defect scanning or defect detection on the upper surface of the object. When there are two detection systems, these two detection systems can be positioned on both sides of the object under test, for example, symmetrically or asymmetrically.

[0204] In one possible implementation, when collecting scattered light during dark-field processing, multiple detection systems can be placed on the object under test. Each detection system includes a collection channel and a corresponding detector. These multiple detection systems can be symmetrically distributed along the perpendicular line to the surface of the object under test, and symmetrical about the incident plane. Therefore, when the defects on the surface of the object under test are symmetrical, the two symmetrical detection systems receive the same signal; when the defects on the surface of the object under test have different geometric features, the two symmetrical detection systems receive different signals, thus enabling the determination of the geometric features of the defects. Of course, the multiple detection systems can also be asymmetrically distributed.

[0205] In one possible implementation, the collection channel can be either a normal probe channel or a non-normal collection channel. A normal collection channel is one where the probe channel lies in the direction of the normal to the surface of the object under test, and can be considered to be located directly above the object. A non-normal collection channel is one where the collection channel deviates from the direction of the normal to the surface of the object, and can be considered to be located diagonally above the object.

[0206] 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. Furthermore, the light source may be configured to produce light of any suitable wavelength (e.g., about 355 nm, about 266 nm, or about 193 nm).

[0207] 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 focusing at least a portion of the light from the sample of the object under test. The additional optical elements may be, for example, one or more apertures, one or more lenses, one or more splitters, one or more polarizing elements, one or more filters, one or more reflective optical elements, and one or more refractive optical elements.

[0208] In one possible implementation, the platform (e.g., first platform 14 or second platform 19) can be an edge-gripping chuck, a vacuum chuck, etc. A platform can support multiple object diameters (e.g., 300 mm and 450 mm) or a single object diameter.

[0209] In one possible implementation, the optical path may further include an axis coupled to a chuck and to a positioning subsystem. The positioning subsystem may include various elements configured to rotate and / or translate the axis, such as motors, gears, etc. The axis may be coupled to the chuck in such a way 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 (DUT). The platform may translate the DUT in a helical or XY manner, or some combination of both as further described herein. In particular, in addition to helical scanning as described above, XY serpentine scanning and RT-XY hybrid scanning can both be used to translate the DUT relative to the illumination and collection optics.

[0210] In one possible implementation, the light beam emitted by the light source can be incident perpendicularly to the surface of the object under test, or incident obliquely to the surface of the object under test. As an example, in the case of perpendicular incidence, multiple detection channels can be positioned obliquely above the object under test to detect reflected light from the surface. In the case of oblique incidence, the multiple detection channels located obliquely above the object under test can detect scattered light from the surface.

[0211] In one possible implementation, scattered or reflected light from the surface of the object under test is detected, and its exit surface can be perpendicular to the incident surface of the light emitted by the light source, or have an acute angle between them.

[0212] In one possible implementation, when scanning defects using bright-field processing, a detection system can be used to collect reflected light; when detecting defects using dark-field processing, a detection system can be used to collect scattered light. Furthermore, in bright-field processing, a detection system located directly above the object under test can collect normally incident reflected light, while a detection system located obliquely above the object under test can collect obliquely incident reflected light. The detection system includes a collection channel and a corresponding detector.

[0213] In one possible implementation, for any optical path, such as a scanning or detection optical path, multiple light rays can be emitted, allowing them to strike the surface of the object under test at different angles. The light is reflected or scattered by the surface of the object to obtain signal light, which is then collected using different detection systems. Each detection system includes a collection channel and a corresponding detector. By providing multiple light rays incident on the object, defects of different sizes can be detected. Different incident angles between the light rays and the object result in different sensitivities for defect scanning or detection, thus meeting various user requirements for detection sensitivity. When the defect size is small, the sensitivity of defect detection or defect scanning can be appropriately increased to avoid missed detections.

[0214] In one possible implementation, the light beam emitted by the light source, after being shaped, illuminates the surface of the object under test as either a point spot or a line spot. During dark-field processing, if a defect exists at the illumination location, the defect will cause some light to be scattered upwards at various angles. Therefore, multiple scattered light collection channels can be set at different locations to detect the intensity of scattered light at different angles, allowing the determination of defect information at the spot's location. Understandably, collecting signal light through multiple signal collection channels can improve detection accuracy. The detection branches corresponding to each collection channel include a detection lens group and a detector to achieve imaging collection of the signal light. When a line detector is used, the detection area is linear.

[0215] In one possible implementation, the light beam emitted by the light source can be divided into multiple offset beams, and the phase characteristics between the multiple offset beams can be adjusted so that they can be simultaneously focused on the surface of the object under test.

[0216] In one possible implementation, when collecting scattered light (for dark-field processing) or reflected light (for bright-field processing) from the surface of the object under test, a large numerical aperture (NA) objective lens can be used for light collection; that is, the scattered or reflected light passes through the large NA objective lens before entering the detector. Furthermore, for reflected or scattered light, optical elements can be configured to distribute light of different wavelengths into different collection channels.

[0217] In one possible implementation, when collecting scattered or reflected light from the surface of the object under test, the reflected or scattered light can be split into two beams, which then enter different collection channels for defect imaging. In another possible implementation, the light beam emitted by the light source can be incident obliquely onto the surface of the object under test, or it can be incident directly, depending on the specific circumstances. When using an oblique dark-field scanning optical path for defect scanning, the light beam emitted by the light source is obliquely incident, and it will not be incident directly onto the surface of the object under test.

[0218] In one possible implementation, the light scattered by the surface of the object under test can be collected and focused by a lens condenser and guided into the detector. As an example, the lens condenser can be ellipsoidal.

[0219] The following is a detailed description of how the movement of the first platform 14 and the second platform 19 is achieved. Referring to Figure 7, which is a schematic diagram of a motion platform provided in an embodiment of this application, the movement and rotation of the first platform 14 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. 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, which may include a linear motor and a guide rail. The conveying mechanism 302 can also use a lead screw or a conveyor belt to move the first platform 14 and the second platform 19. The motion platform can achieve X, Y, and R-axis movements, where X and Y represent orthogonal coordinate systems, and the R-axis represents rotation around the Z-axis. Referring to Figure 1c, the X and Y axis movements allow the first platform 14 and the second platform 19 to move within the plane of the moving stage, enabling the first platform 14 to switch between the first bright field position 104 and the dark field position 106, and the second platform 19 to switch between the second bright field position 105 and the dark field position 106. The first platform 14 and the second platform 19 can each rotate around the R axis on the moving plate 301. The coordinated movement of the X, Y, and R axes enables spiral scanning (RT), XY serpentine scanning, or RT-XY hybrid scanning of the object under test to be performed at the first bright field position 104, the second bright field position 105, and the dark field position 106.

[0220] The detection method provided in this application can be applied to a detection system, specifically through a computer subsystem to control the detection system to achieve adjustments to the optical path, platform movement, etc. The computer subsystem can include any suitable computer system known in the art. For example, a computer subsystem can take various forms, including personal computer systems, mainframe computer systems, workstations, image processing computers, parallel processors, or any other device known in the art. Generally, the term "computer subsystem" can be broadly defined as any device containing one or more processors that execute instructions from a storage medium.

[0221] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on its differences from other embodiments. In particular, the apparatus embodiments are basically similar to the method embodiments, so they are described more simply; relevant parts can be referred to the descriptions of the method embodiments.

[0222] The above description is merely a preferred embodiment of this application. Although this application has disclosed preferred embodiments above, it is not intended to limit this application. Any person skilled in the art can make many possible variations and modifications to the technical solutions of this application using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the scope of the technical solutions of this application. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this application without departing from the content of the technical solutions of this application shall still fall within the protection scope of the technical solutions of this application.

Claims

1. A detection system, characterized in that, The detection system includes a first bright-field detection optical path, a second bright-field detection optical path, a dark-field detection optical path, a first platform, and a second platform; Both the first platform and the second platform are used to carry the object to be tested. The first platform switches between a first bright field position and a dark field position, and the second platform switches between a second bright field position and the dark field position. The first bright field position and the second bright field position are respectively located on the light-emitting side of the first bright field detection optical path and the second bright field detection optical path, and the dark field position is located on the light-emitting side of the dark field detection optical path. While the dark field detection optical path is used to perform dark field detection on the i-th test object at the dark field position, the target optical path is used to perform bright field detection on the (i+1)-th test object at the target position; the target optical path is the first bright field detection optical path or the second bright field detection optical path, and the target position is the first bright field position or the second bright field position; i≥1.

2. The detection system according to claim 1, characterized in that, The detection system includes a basic optical path, which includes a first light source for emitting a first beam; the dark field detection optical path includes an adjustment module. When the adjustment module is in the first state, the dark field detection optical path is used to make the first beam obliquely incident on the object to be tested for dark field detection. When the adjustment module is in the second state, the dark field detection optical path is used to make the first beam perpendicularly incident on the object under test for dark field detection.

3. The detection system according to claim 1, characterized in that, The detection system includes a first scanning optical path and a second scanning optical path; the first bright field position is located on the light-emitting side of the first scanning optical path, and the second bright field position is located on the light-emitting side of the second scanning optical path; While the first bright-field detection optical path is used to perform bright-field detection on the i-th test object located at the first bright-field position, the first scanning optical path is used to scan the i-th test object located at the first bright-field position. While the second bright-field detection optical path is used to perform bright-field detection on the i-th test object located at the second bright-field position, the second scanning optical path is used to scan the i-th test object located at the second bright-field position.

4. The detection system according to claim 3, characterized in that, The detection system includes a basic optical path and a switching module. The basic optical path includes a first light source and a first beam splitting module. The first beam splitting module is used to split the first beam emitted by the first light source into a dark field detection beam incident on the dark field detection optical path, and a target scanning beam incident on the first scanning optical path or the second scanning optical path; the switching module is used to switch the scanning beam between the first scanning optical path and the second scanning optical path.

5. The detection system according to claim 3, characterized in that, The detection system includes a basic optical path, the switching module, and a second light source. The basic optical path includes a first light source and a first beam-splitting module. The first beam splitting module is used to split the first beam emitted by the first light source into a redundant beam and a dark field detection beam incident on the dark field detection optical path. The second light source is used to emit a first scanning beam, and the switching module is used to switch the first scanning beam between the first scanning optical path and the second scanning optical path.

6. The detection system according to claim 5, characterized in that, The basic optical path also includes a light absorption module located on the side of the first beam splitter from which the redundant beam is emitted, the light absorption module being used to absorb the redundant beam.

7. The detection system according to claim 5, characterized in that, The optical power of the first light source is greater than that of the second light source.

8. The detection system according to claim 3, characterized in that, The detection system includes a basic optical path, a second light source, and a third light source. The basic optical path includes a first light source and a first beam-splitting module. The first beam splitting module is used to split the first beam emitted by the first light source into a redundant beam and a dark field detection beam incident on the dark field detection optical path. The second light source is used to emit a first scanning beam that is incident on the first scanning optical path; The third light source is used to emit a second scanning beam that is incident on the second scanning optical path.

9. The detection system according to any one of claims 1-8, characterized in that, The dark field detection optical path also includes a switch; When the switch is in the open state, the switch is used to enable the dark field detection beam to perform dark field detection on the surface of the object under test that belongs to the second defect category; When the switch is in the off state, the switch is used to prevent the dark field detection beam from performing dark field detection on the target defect belonging to the first defect category on the surface of the test object; in the defect scanning result obtained after scanning the i-th test object, 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.

10. A detection method, characterized in that, The method, applied to the detection system as described in any one of claims 1-9, comprises: The i-th test object is moved from the initial bright field position to the dark field position; the initial bright field position is either the first bright field position or the second bright field position, and the i-th test object has already completed bright field detection at the initial bright field position; Position the (i+1)th test object at the target bright-field position; the target bright-field position is different from the initial bright-field position. While performing dark field detection on the i-th test object at the dark field position using the dark field detection beam based on the dark field detection optical path, bright field detection is performed on the (i+1)-th test object at the target position based on the target optical path.

11. The detection method according to claim 10, characterized in that, The detection system includes a basic optical path, which includes a first light source for emitting a first beam; the dark field detection optical path includes an adjustment module; the dark field detection of the i-th object at the dark field position based on the dark field detection optical path and the dark field detection beam includes: Turn on the first light source and use the first beam as the dark field detection beam; The adjustment module is in the first state, and based on the dark field detection optical path, the dark field detection beam is obliquely incident on the i-th test object located in the dark field position to perform dark field detection; The adjustment module is in the second state, and based on the dark field detection optical path, the dark field detection beam is perpendicularly incident on the i-th test object located in the dark field position to perform dark field detection.

12. The detection method according to claim 10, characterized in that, The detection system includes a first scanning optical path and a second scanning optical path; the first bright field position is located on the light-emitting side of the first scanning optical path, and the second bright field position is located on the light-emitting side of the second scanning optical path; the step of performing dark field detection on the i-th test object located at the dark field position using the dark field detection beam based on the dark field detection optical path, and simultaneously performing bright field detection on the (i+1)-th test object located at the target position based on the target optical path, includes: While performing dark field detection on the i-th test object at the dark field position based on the dark field detection optical path and the dark field detection beam, performing bright field detection on the (i+1)-th test object at the target position based on the target optical path, and performing scanning processing on the (i+1)-th test object at the target position based on the target scanning optical path and the target scanning beam; The target scanning optical path is either a first scanning optical path or a second scanning optical path, the first bright field position is located on the light-emitting side of the first scanning optical path, and the second bright field position is located on the light-emitting side of the second scanning optical path.

13. The detection method according to claim 12, characterized in that, The detection system includes a basic optical path and a switching module. The basic optical path includes a first light source and a first beam splitting module. Before performing dark-field detection on the i-th test object at the dark-field position using the dark-field detection beam based on the dark-field detection optical path, performing bright-field detection on the (i+1)-th test object at the target position based on the target optical path, and performing scanning processing on the (i+1)-th test object at the target position using the target scanning beam based on the target scanning optical path, the method further includes: When the first light source is turned on, the first beam emitted by the first light source is split into a dark field detection beam incident on the dark field detection optical path and a target scanning beam incident on the target scanning optical path through the switching module and the first beam splitting module.

14. The detection method according to claim 12, characterized in that, The detection system includes a basic optical path, the switching module, and a second light source. The basic optical path includes a first light source and a first beam splitting module. Before performing dark-field detection on the i-th test object at the dark-field position using the dark-field detection beam based on the dark-field detection optical path, performing bright-field detection on the (i+1)-th test object at the target position based on the target optical path, and performing scanning processing on the (i+1)-th test object at the target position using the target scanning beam based on the target scanning optical path, the method further includes: The first beam emitted by the first light source is split into a redundant beam and a dark field detection beam incident on the dark field detection optical path by the first beam splitting module. Turn on the second light source, and through the switching module, direct the target scanning beam emitted by the second light source toward the target scanning optical path.

15. The detection method according to claim 12, characterized in that, The detection system includes a basic optical path, a second light source, and a third light source. The basic optical path includes a first light source and a first beam splitting module. Before performing dark-field detection on the i-th test object at the dark-field position using the dark-field detection beam based on the dark-field detection optical path, performing bright-field detection on the (i+1)-th test object at the target position based on the target optical path, and performing scanning processing on the (i+1)-th test object at the target position using the target scanning beam based on the target scanning optical path, the method further includes: The first beam emitted by the first light source is split into a redundant beam and a dark field detection beam incident on the dark field detection optical path by the first beam splitting module. The target light source is determined based on the target scanning optical path; the target light source is either the second light source or the third light source. Turn on the target light source, use the light beam emitted by the target light source as the target scanning beam, and make the target scanning beam incident on the target scanning optical path.

16. The detection method according to claim 12, characterized in that, The defect scanning result obtained by scanning the i-th test object includes the defect location of each defect on the surface of the i-th test object and the light intensity of each defect. Before performing dark field detection on the i-th object to be tested at the dark field position using the dark field detection beam through the dark field detection optical path, the method further includes: The defect category to which each defect belongs is determined based on the light intensity; different defect categories correspond to different light intensity ranges; The step of performing dark field detection on the i-th object to be tested at the dark field position using the dark field detection beam through the dark field detection optical path includes: Based on the dark field detection optical path, the dark field detection beam traverses each position on the i-th surface of the object to be tested to perform dark field detection; When performing dark-field detection on a target defect located at the target defect position, the target defect is detected by the dark-field detection beam with the target optical power; the target optical power is determined based on the defect category to which the target defect belongs.

17. The detection method according to claim 16, characterized in that, The optical power of the target scanning beam is less than the optical power of the dark field 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.

18. The detection method according to claim 17, characterized in that, The dark field detection optical path further includes a switch; the defect detection of the target defect using the dark field detection beam with the target optical power includes: When the target defect belongs to the second defect category, the switch is controlled to be in the open state, and the dark field detection beam passes through the switch to detect the target defect; When the target defect belongs to the first defect category, the switch is controlled to be in the off state, the dark field detection beam is blocked by the switch, and the target defect is not detected.

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