An inspection system and defect detection apparatus

Abstract

The application relates to the technical field of semiconductor front-end detection, and discloses a dark-field detection system, specifically a detection system and a defect detection device. In the technical scheme provided by the application, the loading or unloading of an adjusting mirror group on the propagation path of an incident light beam is controlled to form oblique incident light beams and vertical incident light beams with different incident angles, the adjustment of different incident modes of the incident light beam is realized, and one main incident light beam is shared by the oblique incident light beams and the vertical incident light beams, so that the redundancy of the system is reduced. In addition, a focusing objective lens which can be synchronously controlled with the adjusting mirror group is arranged, the position change of the focusing objective lens on the optical axis of the incident light beam is controlled to realize the adjustment of the corresponding focal lengths of the oblique incident light beams and the vertical incident light beams, and the optical paths of the oblique incident light beams and the vertical incident light beams are kept consistent.

Description

Technical Field

[0001] This application relates to the field of semiconductor front-end inspection technology, specifically a dark field inspection system and a defect detection device. Background Technology

[0002] As the substrate for chips, wafers are susceptible to defects on their surface, which can lead to chip failure, reduced yield, and increased manufacturing costs. Therefore, a common practice is to perform wafer surface defect detection before or during chip fabrication. Wafer surface defect detection refers to detecting the presence and location of defects such as grooves, particles, and scratches on the wafer surface.

[0003] Currently, dark-field scanning systems are commonly used for wafer surface defect detection. These systems typically use a beam splitter at the laser exit to divide the beam into two incident modes: perpendicular and oblique. This allows them to acquire scattering information from the defects, detecting and reflecting the scattering information from different locations using the same method. Generally, a perpendicular-incident system includes a set of beam expanders, shaping lenses, and focusing objectives, distributed at different locations within the system. However, these beam expanders, shaping lenses, and focusing objectives usually use the same type of lens or lens group, increasing the equipment size and basic cost. Furthermore, these two subsystems require separate assembly and debugging, leading to reduced light energy utilization and a cumbersome and complex debugging process. Summary of the Invention

[0004] To address the technological gaps in the existing technology, this application provides a detection system and defect detection equipment that can share some optical components to adjust the incident beam type in real time while ensuring the accuracy of the detection results, thereby reducing system-level costs and installation and debugging costs.

[0005] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows:

[0006] In a first aspect, a detection system is provided, the system comprising: a main incident beam, the main incident beam being incident at an oblique angle to an object to be detected and forming a first incident spot on the surface of the object to be detected; an adjustment mirror group, including at least one reflector, selectively configured on the propagation path of the main incident beam, for changing the propagation direction of the main incident beam and causing the main incident beam to propagate to a vertical mirror group, the vertical mirror group being used to change the propagation direction of the main incident beam and form a perpendicular incident beam relative to the object to be detected as a positive incident beam, and forming a second incident spot on the surface of the object to be detected; at least one focusing objective lens is disposed on the propagation path of the main incident beam, and focal length adjustment is achieved by controlling the distance between the focusing objective lens and the object to be detected, wherein the first incident spot and the second incident spot have the same size, shape, incident position, and the same energy distribution.

[0007] In another possible implementation, a movable focusing objective is provided on the propagation path of the main incident beam, and the movable focusing objective can be moved along the optical axis of the main incident beam.

[0008] In another possible implementation, a fixed focusing objective and an adjustable focusing objective are disposed on the propagation path of the main incident beam; the adjustable focusing objective is selectively configured on the main incident beam following the adjustment lens group, and the adjustable focusing objective is positioned closer to the object to be detected relative to the fixed focusing objective.

[0009] In another possible implementation, the vertical mirror assembly includes two opposing mirrors, one mirror for receiving the incident light beam reflected by the adjustment mirror assembly and projecting it onto the other mirror, and the other mirror for projecting the incident light beam onto the surface of the object to be inspected in a normal incidence manner.

[0010] In another possible implementation, the adjusting mirror assembly includes two opposing mirrors, one for receiving the main incident beam and projecting it onto the vertical objective lens via the other mirror.

[0011] In another possible implementation, the vertical mirror assembly includes a reflector for receiving the incident light beam reflected by the adjustable mirror assembly and projecting the incident light beam onto the surface of the object to be inspected in a normal incidence manner.

[0012] In another possible implementation, a functional optical lens group is also provided on the main incident beam for adjusting the optical state of the main incident beam.

[0013] In another possible implementation, the functional optical lens group includes a polarizer for changing the polarization state of the main incident beam.

[0014] In another possible implementation, the functional optical lens group includes a beam expander and a shaping lens for morphological adjustment of the main incident beam.

[0015] In another possible implementation, the main incident beam is generated by a laser source and its propagation path is changed by a first and a second reflecting mirror to form an incident relationship at an angle to the object to be detected.

[0016] Secondly, a defect detection device is provided, comprising: a stage for placing an object to be detected and moving it along an equidistant spiral; a detection system as described in any of the preceding claims, for sequentially generating a first incident light spot and a second incident light spot having the same size, shape, incident position, and energy distribution onto the surface of the object to be detected based on a scanning cycle, and generating corresponding first scattered light beams and second scattered light beams via the object to be detected; a detector assembly for sequentially receiving the first scattered light beams and the second scattered light beams and generating corresponding scattered light signals; and a processing center for processing the scattered light signals to obtain detection results.

[0017] The embodiments of the present invention bring the following beneficial effects:

[0018] In the technical solution provided in this application, by controlling the loading or unloading of the adjustment lens group along the propagation path of the incident beam, oblique incident beams and perpendicular incident beams with different incident angles are formed, thereby achieving adjustment of different incident modes of the incident beam. The sharing of a single main beam by the oblique and perpendicular incident beams reduces system redundancy. Furthermore, by setting a focusing objective lens that can be synchronously controlled with the adjustment lens group, the focal length of the oblique and perpendicular incident beams is adjusted by controlling the position change of the focusing objective lens on the optical axis of the incident beam, ensuring that the optical path lengths of the oblique and perpendicular incident beams remain consistent.

[0019] Other features and advantages of this disclosure will be set forth in the following description, or some features and advantages may be inferred from the description or determined without doubt, or may be learned by practicing the techniques described above.

[0020] To make the above-mentioned objects, features and advantages of this disclosure more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] The system shown in the accompanying drawings will be further described according to exemplary embodiments. These exemplary embodiments will be described in detail with reference to the drawings. These exemplary embodiments are non-limiting exemplary embodiments, wherein example figures represent similar mechanisms in the various views of the drawings.

[0023] Figure 1 This is a schematic diagram of the detection system modules;

[0024] Figure 2 This is a schematic diagram of the structure of a detection system;

[0025] Figure 3 This is a schematic diagram of another part of the detection system;

[0026] Figure 4 This is a schematic diagram of the overall structure of the detection system. Detailed Implementation

[0027] To better understand the above technical solutions, the technical solutions of this application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of this application and the specific features in the embodiments are detailed descriptions of the technical solutions of this application, rather than limitations on the technical solutions of this application. In the absence of conflict, the embodiments of this application and the technical features in the embodiments can be combined with each other.

[0028] In the detailed description below, numerous specific details are illustrated with examples to provide a comprehensive understanding of the relevant guidance. However, it will be apparent to those skilled in the art that this application can be practiced without these details. In other instances, well-known methods, procedures, systems, components, and / or circuits have been described at a relatively high level without detail to avoid unnecessarily obscuring aspects of this application.

[0029] This application uses flowcharts to illustrate the execution process performed by a system according to embodiments of this application. It should be clearly understood that the execution processes in the flowcharts may not be executed sequentially. Instead, these execution processes may be executed in reverse order or simultaneously. Additionally, at least one other execution process may be added to the flowchart. One or more execution processes may be deleted from the flowchart.

[0030] This application provides a dark field detection system for dark field detection. It detects the object by projecting a laser of a specific wavelength onto the surface of the object to be tested, forming a light spot. The object to be tested is a wafer. In this embodiment, "wafer" generally refers to a substrate formed of semiconductor or non-semiconductor materials. Examples include (but are not limited to) single-crystal silicon, gallium arsenide, gallium nitride, and indium phosphide. Such substrates are typically found and / or processed in semiconductor manufacturing facilities. In some cases, the wafer may contain only the substrate (i.e., a bare die). Alternatively, the wafer may contain one or more different material layers formed on the substrate. The one or more layers formed on the wafer may be "patterned" or "unpatterned." For example, the wafer may contain multiple dies with repeatable pattern features.

[0031] Dark-field laser scattering (DLS) is an effective detection method based on the principle of light scattering. Specifically, the device uses a high-precision laser beam to illuminate the wafer surface. When the laser encounters defects on the surface, it generates scattered light. These scattered light signals are collected and analyzed by a highly sensitive detector, thus accurately reflecting the distribution of nanoscale defects on the wafer surface.

[0032] The generated laser beams include both obliquely incident and perpendicularly incident beams. These two types of laser beams can collect scattered light signals from different defect types at the same wafer location, thus enabling the detection to balance detection efficiency and defect coverage.

[0033] In existing technologies, to obtain the aforementioned two-beam system, a beam splitter is typically used at the laser exit position to divide the incident beam into a vertically incident beam and an obliquely incident beam. Furthermore, other functional devices, such as beam expanders, shaping lenses, and focusing lenses, are configured in both incident beams. However, in practical use, the applicant has found that because these functional devices typically use the same type of lens or lens group, configuring them separately in the two incident beams increases the equipment size and basic cost. Moreover, the two incident beams require separate assembly and debugging, which also leads to reduced light energy utilization and a cumbersome and complex debugging process.

[0034] Based on the above technical background and in order to solve the above technical problems, this embodiment provides a detection system that integrates oblique incident beams and vertical incident beams through optical path structure settings, reducing the cost increase caused by configuring multiple functional devices individually. Furthermore, since the oblique incident beams and vertical incident beams share the same set of functional devices, the difficulty of system assembly and debugging is reduced, thereby solving technical problems such as decreased light energy utilization and complex debugging process.

[0035] For details regarding its specific structure, please refer to [link / reference]. Figure 1A detection system 100, applied to wafer inspection, includes a first incident beam 110, an adjustment mirror group 120, and a vertical mirror group 130. The first incident beam is the original incident beam of the system, generated by excitation from a light source. The adjustment mirror group, optionally positioned along the propagation path of the first incident light, is designed as an optical device or group of optical devices capable of light reflection, serving to alter the propagation path of the first incident light as needed to form a reflected light path.

[0036] The vertical mirror group is positioned along the propagation path of the reflected light and is designed as an optical device or group of optical devices capable of light reflection. Its function is to further alter the propagation path of the reflected light and project it onto the surface of the wafer to be tested, forming a second incident beam 140 with the same optical conditions as the first incident beam but a different incident angle. The aforementioned adjustment mirror group and vertical mirror group are only used to change the light propagation path and do not alter the optical characteristics.

[0037] In this embodiment, the first incident beam is the original optical path, and its incident angle relative to the wafer under test is an oblique incident angle. The second incident beam, after being altered by the adjusting mirror group and the vertical mirror group, has an incident angle relative to the wafer under test 20 that is a perpendicular incident angle. This means that, in this embodiment, the incident angle of the incident beam in the detection system can be changed by adjusting the adjusting mirror group and the vertical mirror group.

[0038] In this embodiment, the incident beams corresponding to the first and second incident optical paths are projected onto the same position on the wafer to be inspected, generating corresponding first and second incident light spots. This can be understood as follows: in this embodiment, the switching between the first and second incident optical paths can be achieved by adjusting the mirror group, and a corresponding positive incident light is formed by the vertical mirror group, thus forming a corresponding detection light spot on the wafer to be inspected.

[0039] The control over whether the adjustment mirror group is positioned on the propagation path of the first incident beam is achieved by adjusting the spatial height position of the current adjustment mirror group. It is worth noting that, in this embodiment, the spatial position is based on the wafer under test, and the spatial height position of the adjustment mirror group refers to its height relative to the wafer under test.

[0040] Specifically, the adjusting mirror assembly includes at least two height positions. The first height position is where the adjusting mirror assembly is positioned to be loaded onto the first incident beam propagation path, and the remaining height positions are where the adjusting mirror assembly is positioned to be unloaded from the second incident beam propagation path. This can be understood as follows: depending on the beam type, by controlling the adjusting mirror assembly at the first or second height position, the adjusting mirror assembly is positioned either onto the first incident beam propagation path or unloaded from the second incident beam propagation path. It is worth noting that the height change of the adjusting mirror assembly is achieved through external power, including but not limited to motors, pneumatic devices, and other power components.

[0041] In one possible implementation, the adjustment mirror group in this embodiment is designed to be selectively configured in the first incident light path to adjust the incident angle of the first incident beam. Since the original incident state of the first incident beam is that it is incident at an angle relative to the wafer under test, it can be understood that when the adjustment mirror group is configured in the first incident beam, it can change the incident angle of the first incident beam, and by setting a second mirror group on the beam after the light propagation direction has been changed, the light propagation path is changed to form a second incident beam that is perpendicular to the wafer under test. When the adjustment mirror group is not configured in the first incident beam, the first incident beam maintains its original incident state and projects incident light with an angle onto the wafer under test.

[0042] In this embodiment, the flexible configuration of the adjustment mirror group on the first incident beam is achieved through movement control. That is, the adjustment mirror group can be controlled to enter or leave the propagation path of the first incident beam by moving in or out of the propagation path of the first incident beam.

[0043] Please continue reading. Figure 1 The adjustment mirror group and the vertical mirror group include at least three mirrors, with three mirrors preferred for the sake of optical path control simplicity, including a first mirror 101, a second mirror 102, and a third mirror 103. The first mirror reflects the first incident beam to the second mirror, which then reflects it to the third mirror. These three mirrors form an optical propagation path, creating an incident beam with a perpendicular incident angle to the wafer under test.

[0044] In one possible implementation, the second reflector 102 and the third reflector 103 form a vertical mirror group 130, and the first reflector 101 serves as an adjustment mirror group 120. The control and adjustment of the adjustment mirror group is equivalent to the control and adjustment of the first reflector. Specifically, according to the required incident beam type, the height position of the first reflector relative to the wafer under test is controlled, causing the first reflector to enter or leave the first incident beam propagation path. When the first reflector is entered into the first incident beam propagation path, the first incident beam is reflected to the vertical mirror group, and through the vertical mirror group, a second incident beam with a perpendicular incident angle is formed and directed to the wafer under test. When the first reflector is removed from the first incident propagation path, the first incident beam, based on its original propagation path, reaches the wafer under test at an inclined incident angle.

[0045] In this embodiment, the vertical mirror group includes a second reflector and a third reflector. The second reflector is disposed on the reflected light path generated by the first reflector and reflects the reflected light path a second time to the third reflector, forming a vertically incident second incident beam through the third reflector.

[0046] In another possible implementation, the first reflecting mirror 101 and the second reflecting mirror 102 are used as an adjustment mirror group 120, and the third reflecting mirror 103 is used as a vertical mirror group 130. By adjusting the spatial height position of the first and second reflecting mirrors, the formation of a first incident beam or a second incident beam can be controlled. Since only the controlled object is changed in this process, but its light propagation path remains unchanged, the light propagation path will not be described again.

[0047] In another possible implementation, the first reflector, the second reflector, and the third reflector are treated as a single mirror group, and the switching between the first incident beam and the second incident beam is achieved by synchronously controlling the three mirror groups.

[0048] In this embodiment, based on the control cost and fewer interference factors in the first possible implementation, the mirror group control method in the first possible implementation is preferred, which achieves the switching of the first incident beam and the second incident beam by controlling the first reflecting mirror.

[0049] Please continue reading. Figure 1 In this embodiment, in order to ensure the uniformity of the incident beam illumination and to control multiple optical conditions such as the size of the formed spot to meet the detection requirements, at least one focusing objective is set in the main incident beam path to realize the focal length adjustment of the beam.

[0050] However, it is worth noting that the incident beam in this embodiment includes two incident beams, and the second incident beam is generated by changing the propagation path of the first incident beam. This optical design will cause the optical path lengths of the first and second incident beams to be inconsistent. Therefore, in this embodiment, in order to make the optical path lengths of the first and second incident beams consistent, and to ensure that the corresponding detection spots have the same size, shape, incident position, and energy distribution, the optical design is optimized.

[0051] In this embodiment, in order to solve the above problems, the focal length of the focusing objective is adjusted for different incident beams by controlling its distance from the wafer under test along the optical axis.

[0052] This can be understood as follows: for different types of incident beams, namely the first incident beam and the second incident beam, the relative positions of the focusing objective and the wafer under test are different, thereby achieving the adjustment of the focal length corresponding to the two incident beams, so that the first incident beam and the second incident beam form the first incident spot and the second incident spot on the wafer under test with the same size, shape, incident position and the same energy distribution.

[0053] In one possible implementation, the focusing objective 105 is positioned on the optical axis of the first incident beam. Depending on the type of incident beam, the focusing objective is moved along the optical axis to a first position or a second position by an external power source. Figure 1 The direction indicated by the arrow shown is the direction of movement of the focusing objective. Figure 1 The position of the medium-focusing objective lens on the first incident beam is the first position. The second position is closer to the wafer under test than the first position.

[0054] Specifically, when the current incident beam is the second incident beam, the focusing objective is moved along the optical axis from the first position to the second position by an external power source. When the current incident beam is the first incident beam, the focusing objective is moved along the optical axis from the second position to the first position by an external power source.

[0055] It is worth noting that, in this embodiment, the movement of the focusing objective should be synchronized with the movement of the adjusting lens group; that is, when the position of the adjusting lens group is adjusted to the desired position, the position of the corresponding focusing objective should also be adjusted to the desired position. Therefore, in this embodiment, both the adjusting lens group and the focusing objective are connected to the same controller. The controller simultaneously issues adjustment commands and controls the adjusting lens group and the focusing objective to move to the target position according to their movement speed.

[0056] See Figure 2Another embodiment of the focusing objective configuration, in which the focusing objective is configured as a lens group, includes a first focusing objective 105 and a second focusing objective 106. The first focusing objective is a fixed focusing objective positioned at a first position on the propagation path of the main incident beam. The second focusing objective is an adjustable focusing objective, selectively positioned at a second position on or off the propagation path of the main incident beam depending on the type of incident beam. Furthermore, both the first and second positions are located on the optical axis of the first incident beam, and there is a distance between the first and second positions, with the second distance being closer to the wafer under test than the first distance.

[0057] Specifically, when the current incident beam type is the first incident beam, the second focusing objective is controlled to move away from the incident beam, and only the first focusing objective is positioned on the incident beam optical axis, thereby focusing the first incident beam. When the incident beam type is the second incident beam, the second focusing objective is controlled to move into the incident beam, and both the first and second focusing objectives are positioned on the incident beam optical axis, thereby focusing the second incident beam.

[0058] The loading and unloading control of the second focusing objective is the same as the adjustment control of the lens assembly, achieved by adjusting the height of the second focusing objective. Specifically, when the second focusing objective needs to load the incident beam, it is adjusted from the first height to the second height so that the second focusing objective is positioned on the incident beam; when the second focusing objective needs to unload the incident beam, it is adjusted from the second height to the first height. It is worth noting that the first and second heights of the focusing objective in this embodiment are based on the wafer to be inspected. The movement path of the second focusing objective can be referred to by the arrows in the figure.

[0059] As described above, unlike one possible implementation, this implementation does not require adjustment of the focusing objective along the optical axis. The focal length is adjusted by placing another focusing objective on the second incident beam. However, the principle of this solution is the same as the previous possible implementation: the focal length is changed by adjusting the distance between the focusing objective and the wafer to be tested.

[0060] It is worth noting that the loading and unloading of the second focusing objective in this embodiment needs to be synchronized with the loading and unloading of the adjusting lens group. Similarly, the second focusing objective and the adjusting lens group should be connected to the same controller for communication. The controller simultaneously issues adjustment commands and controls the adjusting lens group and the second focusing objective to move to the target position according to their moving speeds.

[0061] See Figure 3In another possible implementation, the detection system is further provided with a functional optical lens group 140 on the main incident beam to adjust the optical state of the main incident beam, so that the excited first incident beam and the second incident beam meet the requirements of wafer detection.

[0062] Specifically, the functional optical lens group includes a polarizer 141, a beam expander 142, and a shaping mirror 143 arranged sequentially according to the light propagation path. The polarizer is used to change the polarization state of the incident beam, while the beam expander and shaping mirror are used to change the shape and size of the incident beam.

[0063] See Figure 4 Furthermore, an implementation method is provided to reduce the space configuration problem of the overall system. In this implementation, in order to reduce the problem of excessive lateral space in the system caused by the main incident beam being an oblique incident beam, multiple objectives are used to make better use of the space.

[0064] Specifically, in the detection system of this embodiment, the main incident beam is emitted by a light source that is parallel to and higher than the wafer to be detected, and the propagation path of the generated main incident beam is also parallel to the wafer to be detected. Two reflecting mirrors are used to obtain the first incident beam in an oblique incidence state, and the aforementioned functional optical mirror group is arranged on the reflected light path to adjust the beam.

[0065] It is worth noting that those skilled in the art should know that although regarding Figure 3 and Figure 4 The configuration of the medium-functional optical lens group is based on Figure 1 The structure shown is for illustrative purposes only, but does not imply that its functional optical lens group can only be configured in... Figure 1 The detection system shown. For Figure 2 The detection system with the optical path structure shown also has adaptability in its functional optical lens group, allowing it to be directly configured in... Figure 2 On the first incident beam of the detection system.

[0066] Finally, while only the optical components of the aforementioned objectives and lens assemblies have been described, those skilled in the art should understand that the lens assemblies include not only the corresponding optical components but also the associated mechanical structures. For example, in an adjustable lens assembly with a barrel structure, the components include a corresponding mirror and a motor connected to the barrel, which drives the barrel to move, thereby achieving loading and unloading.

[0067] The detection system provided in the above embodiments forms oblique and perpendicular incident beams with different incident angles by controlling the loading or unloading of the adjustment lens group along the propagation path of the incident beam. This allows for adjustment of different incident modes of the incident beam, and reduces system redundancy by having the oblique and perpendicular incident beams share a single main beam. Furthermore, by providing a focusing objective lens that can be synchronously controlled with the adjustment lens group, the focal length of the oblique and perpendicular incident beams is adjusted by controlling the position change of the focusing objective lens on the optical axis of the incident beam, ensuring that the optical path lengths of the oblique and perpendicular incident beams remain consistent.

[0068] In this embodiment, the system is also equipped with a controller for adjusting and controlling the spatial position of the adjusting lens group and the focusing objective lens.

[0069] In other embodiments of this example, a defect detection device is provided, which includes a stage, a detector assembly, a processing center, and any of the detection systems described in the various embodiments above. The stage carries the wafer to be inspected and moves along an equidistant spiral path, causing the wafer to follow the movement. The detector assembly receives the scattered light beam generated by the incident light beam from the detection system and the wafer, generating a scattered light signal. The processing center processes the scattered light signal to obtain the detection result.

[0070] In this embodiment, the incident beam includes a first incident beam and a second incident beam, which respectively form a first incident spot and a second incident spot on the surface of the wafer to be inspected, and the first incident spot and the second incident spot have the same size. The first incident beam is an oblique incident beam, and the second incident beam is a perpendicular incident beam, both determined according to the scanning cycle of the current defect detection equipment.

[0071] Specifically, the current scanning cycle and the corresponding incident beam type are determined. Based on the incident beam type, the height of the adjustable mirror assembly is controlled to be at the target height, thus configuring the incident beam of the corresponding type. This incident beam is then projected onto the wafer under test, which moves along an equidistant spiral. The incident beam remains constant, while the wafer under test moves along a specific path based on the stage. The incident beam generates a scattered beam through the wafer, and the detector assembly obtains the scattered signal corresponding to the scattered beam. The scattered signals at all points on the wafer under test are obtained based on the complete motion of the wafer.

[0072] After scanning all sites, a new scanning cycle is initiated based on the detection requirements. The height of the current adjustment mirror group is adjusted according to the new scanning cycle and the corresponding incident beam type to configure the incident beam type, changing it from the previous scanning cycle. If the incident beam type for the previous scanning cycle was an oblique incident beam, the incident beam type for the new scanning cycle is a vertical incident beam. Accordingly, the adjustment mirror group is lowered to adjust the turntable that previously carried out the incident beam propagation path to carry in the incident beam propagation path, thus forming a vertical incident beam. The vertical incident beam is projected onto the wafer under test, and scanning of all sites on the wafer is achieved by moving the equidistant spiral along the wafer. The detector then collects the scattered signals from all sites on the wafer.

[0073] In this embodiment, the detector assembly is positioned along the path of the scattered beam. This scattered beam path includes two paths: one corresponding to a large-angle detection channel and the other to a small-angle detection channel. The detector assembly also includes two sets of detectors positioned along these two paths, one set for collecting small-angle scattered light and the other set for collecting large-angle scattered light.

[0074] The beam splitting of the scattered beams corresponding to the two paths is achieved using an elliptical mirror and a beam splitter. An elliptical mirror is positioned along the main path of the scattered beam, and a beam splitter is placed within the elliptical mirror. The receiving range of the beam splitter corresponds to the divergence range of the small-angle scattered beam. The beam splitter reflects the small-angle scattered light within its field of view to a corresponding set of detectors. The scattered beam that is not reflected by the beam splitter, which is the large-angle scattered light, is received by another set of detectors located at the exit port of the elliptical mirror.

[0075] Both sets of detectors are connected to the processing center, transmitting the collected scattered light signals to the processing center.

[0076] The detection system and defect detection equipment provided in this application embodiment achieve switching between oblique and vertical incident beams by setting an adjustable lens group in the detection system. This reduces the size of the equipment, lowers the equipment investment cost, and improves debugging efficiency. Furthermore, the same set of functional components can be used for both oblique and vertical incident beams, thereby reducing lens processing and debugging errors and improving detection accuracy. By switching the beam settings, the disadvantage of light energy loss caused by the use of beam splitters in the prior art can be reduced, the light density at the wafer surface can be increased, and the detection sensitivity can be further improved.

[0077] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A detection system, characterized in that, The system includes: A main incident beam, wherein the main incident beam is incident at an oblique angle to the object to be detected, and forms a first incident light spot on the surface of the object to be detected; An adjustment mirror group, including at least one reflector, is selectively configured on the propagation path of the main incident beam to change the propagation direction of the main incident beam and propagate the main incident beam to the vertical mirror group; A vertical mirror group is used to change the propagation direction of the main incident beam and form a vertical incident beam relative to the object to be detected as a positive incident beam, and to form a second incident light spot on the surface of the object to be detected. At least one focusing objective is provided on the propagation path of the main incident beam. The focal length is adjusted by controlling the distance between the focusing objective and the object to be detected. The first incident light spot and the second incident light spot have the same size, shape, incident position and the same energy distribution.

2. The detection system according to claim 1, characterized in that, A movable focusing objective is provided on the propagation path of the main incident beam, and the movable focusing objective can move along the optical axis of the main incident beam.

3. The detection system according to claim 1, characterized in that, A fixed focusing objective and an adjustable focusing objective are provided on the propagation path of the main incident beam. The adjustable focusing objective is selectively configured on the main incident beam following the adjustment lens group, and the adjustable focusing objective is positioned closer to the object to be detected relative to the fixed focusing objective.

4. The detection system according to any one of claims 1-3, characterized in that, The vertical mirror assembly includes two opposing mirrors. One mirror receives the incident light beam reflected by the adjustment mirror assembly and projects it onto the other mirror. The other mirror projects the incident light beam onto the surface of the object to be inspected in a normal incident manner.

5. The detection system according to any one of claims 1-3, characterized in that, The adjusting mirror assembly includes two opposing reflectors, one for receiving the main incident beam and projecting it onto the vertical mirror assembly via the other reflector.

6. The detection system according to claim 5, characterized in that, The vertical mirror assembly includes a reflector for receiving the incident light beam reflected by the adjustment mirror assembly and projecting the incident light beam onto the surface of the object to be inspected in a normal incidence manner.

7. The detection system according to claim 1, characterized in that, A functional optical lens group is also provided on the main incident beam for adjusting the optical state of the main incident beam.

8. The detection system according to claim 7, characterized in that, The functional optical lens group includes a polarizer, which is used to change the polarization state of the main incident beam.

9. The detection system according to claim 7, characterized in that, The functional optical lens group includes a beam expander and a shaping lens, used to adjust the shape of the main incident beam.

10. The detection system according to claim 1, characterized in that, The main incident beam is generated by a laser source and its propagation path is changed by the first and second reflecting mirrors to form an incident relationship with the object to be detected at an angle.

11. A defect detection device, characterized in that, include: The stage is used to place the object to be inspected and moves along an equidistant spiral. The detection system according to any one of claims 1-10 is used to sequentially generate a first incident light spot and a second incident light spot with the same size, shape, incident position and the same energy distribution on the surface of the object to be detected based on a scanning cycle, and generate a corresponding first scattered light beam and second scattered light beam through the object to be detected; The detector assembly is used to sequentially receive the first scattered beam and the second scattered beam, and generate corresponding scattered light signals; The processing center is used to process the scattered light signals to obtain the detection results.

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