Lighting mode switching method, detection method, detection system and storage medium

Abstract

The present application discloses a lighting mode switching method, a detection method, a detection system and a storage medium, which belong to the field of semiconductor detection technology. The method includes: in response to a first signal, controlling the lighting mode to switch to a first lighting mode to uniformly illuminate the reference object carried on the stage, and the first signal is used to indicate that the detection system needs to focus; in response to a second signal, controlling the lighting mode to switch to a second lighting mode to illuminate the target area and perform pupil filtering adaptation on the object to be tested carried on the stage, and the second signal is used to indicate that the focus is completed; receiving a third signal, and controlling the lighting mode to switch to a third lighting mode to scan and image the object to be tested, and the third signal is used to indicate that the pupil filtering adaptation of the object to be tested is completed. The present application can switch the lighting mode for different working scenes, thereby meeting the lighting requirements in different working scenes and improving the detection performance.

Description

Technical Field

[0001] The present application relates to the field of semiconductor detection technology, and in particular to a lighting mode switching method, a detection method, a detection system and a storage medium. Background Art

[0002] In dark-field detection systems, a common approach currently is to use a single lighting condition for different work scenarios, which reduces detection accuracy. Furthermore, dark-field detection systems typically inspect the object directly at the theoretical focal plane. However, due to changes in ambient temperature, the initial tracking height of the dark-field detection system can change over time. Following at the nominal focal plane can cause the object to defocus, thus affecting detection results. Summary of the Invention

[0003] To address the problems of the prior art, this application provides a lighting mode switching method, a detection method, a detection system, and a storage medium, which can switch lighting modes for different work scenarios, thereby meeting the lighting needs of different work scenarios and improving detection performance. The technical solution is as follows:

[0004] In one aspect, a lighting mode switching method is provided, the method comprising:

[0005] In response to a first signal, controlling the illumination mode to switch to the first illumination mode to uniformly illuminate the reference object carried on the stage, wherein the first signal is used to indicate that the detection system needs to perform focus search;

[0006] In response to a second signal, controlling the illumination mode to switch to a second illumination mode to illuminate a target area and perform pupil filtering adaptation on the object to be measured carried on the stage, wherein the second signal is used to indicate that focus search is completed, and the target area is a partial area of ​​the object to be measured;

[0007] A third signal is received, and the illumination mode is controlled to switch to a third illumination mode to perform scanning imaging on the object to be measured, wherein the third signal is used to indicate that pupil filtering adaptation of the object to be measured is completed.

[0008] Optionally, after controlling the lighting mode to switch to the first lighting mode in response to the first signal, the method further includes:

[0009] Controlling the relative movement of the stage carrying the reference object and the object to be measured and the objective lens in the vertical direction so that the reference object carried on the stage and the objective lens are at multiple different distances in the vertical direction;

[0010] receiving a plurality of reference images, wherein the plurality of reference images are images obtained by photographing the reference object at each of the distances;

[0011] A target height distance is determined based on the multiple reference images, and the target height distance is used to determine an initial height distance between the stage or the object to be measured and the objective lens when scanning the object to be measured.

[0012] Optionally, determining the target height distance based on the multiple reference images includes:

[0013] For each of the plurality of reference images: determining a plurality of regions of interest in the reference image; determining regional energy concentration values ​​corresponding to the plurality of regions of interest respectively; and determining an image energy concentration value corresponding to the reference image based on the plurality of regional energy concentration values;

[0014] The target height distance is determined based on the image energy concentration values ​​respectively corresponding to the multiple reference images and the height distances respectively corresponding to the multiple reference images.

[0015] Optionally, determining the image energy concentration value corresponding to the reference image based on the multiple region energy concentration values ​​includes:

[0016] An average value of the plurality of regional energy concentration values ​​is used as the image energy concentration value corresponding to the reference image.

[0017] Optionally, the determining the target height distance based on the image energy concentration values ​​respectively corresponding to the plurality of reference images and the height distances respectively corresponding to the plurality of reference images includes:

[0018] Obtaining a reference curve graph according to the plurality of image energy concentration values ​​and the height distances respectively corresponding to the plurality of reference images;

[0019] The height distance corresponding to the maximum image energy concentration value in the reference curve graph is determined as the target height distance.

[0020] Optionally, after determining the target height distance based on the multiple reference images, the method further includes:

[0021] Control the stage to move to the corresponding height in the vertical direction according to the target height distance, and obtain the height value of the upper surface of the reference object when the stage is at this height as the target height value. The target height value is used to indicate the height value that the upper surface of the test area corresponding to the object to be tested needs to be at when it is in the initial scanning position.

[0022] Optionally, the illumination spot of the first illumination mode is a surface illumination spot.

[0023] Optionally, the illumination spot of the second illumination mode is a local illumination spot.

[0024] Optionally, the illumination spot of the third illumination mode is a line illumination spot.

[0025] In another aspect, a detection method is provided, comprising:

[0026] According to the above-mentioned illumination mode switching method, in the third illumination mode, the object to be measured is controlled to be imaged to obtain an image of the object to be measured corresponding to the area to be measured at the current scanning position;

[0027] The area to be tested is detected based on the image to be tested.

[0028] In another aspect, a detection system is provided, comprising:

[0029] The stage is used to carry the object to be tested and the reference object;

[0030] an illumination assembly, configured to switch illumination modes and illuminate at least a portion of the object to be measured or at least a portion of the reference object carried on the stage through an illumination beam;

[0031] An imaging optical path component includes a pupil, a filter, a detection sensor, and an objective lens; the imaging optical path component is used to perform pupil filtering adaptation on the pupil and the filter, and to send a third signal after the pupil filtering adaptation is completed, wherein the third signal is used to indicate that the pupil filtering adaptation of the object to be measured is completed; the imaging optical path component is also used to optically image the object to be measured and the reference object on the stage through the objective lens, and transmit the optical signal obtained by imaging to the detection sensor, wherein the detection sensor is used to convert the optical signal into an electrical signal, thereby obtaining a test image of the object to be measured and a reference image of the reference object;

[0032] a driving assembly, configured to drive the stage and the objective lens to move relative to each other, and to drive the lighting assembly to switch lighting modes;

[0033] A processor is configured to execute the method described in any one of the embodiments herein.

[0034] Optionally, the lighting assembly includes:

[0035] a light source module, configured to emit the illumination light beam;

[0036] A beam expansion module, used to adjust the illumination beam;

[0037] A first light spot shaping module is used to adjust the light spot corresponding to the illumination light beam passing through the beam expansion module to obtain a line illumination spot or a surface illumination spot;

[0038] The second light spot shaping module is used to shape the light spot into a local illumination light spot.

[0039] Optionally, the processor controlling the lighting assembly to switch the lighting mode to the first lighting mode includes:

[0040] Controlling the light source module to emit an illumination beam;

[0041] By adjusting the beam expansion module, the divergence angle and magnification of the illumination light beam passing through the beam expansion module are changed to obtain a first output light beam;

[0042] Adjusting the light spot corresponding to the first outgoing light beam into the surface illumination light spot by the first light spot shaping module;

[0043] The second light spot shaping module is controlled to be cut out so that the second light spot shaping module cannot shape the surface illumination light spot.

[0044] Optionally, the processor controlling the lighting assembly to switch the lighting mode to the second lighting mode includes:

[0045] Controlling the light source module to emit an illumination beam;

[0046] By adjusting the beam expansion module, the divergence angle and magnification of the illumination light beam passing through the beam expansion module are changed to obtain a second output light beam;

[0047] Adjusting the light spot corresponding to the second outgoing light beam into the surface illumination light spot by the first light spot shaping module;

[0048] The second light spot shaping module is controlled to cut in so that the second light spot shaping module shapes the surface illumination light spot into a local illumination light spot.

[0049] Optionally, the processor controlling the lighting assembly to switch the lighting mode to a third lighting mode includes:

[0050] Controlling the light source module to emit an illumination beam;

[0051] By adjusting the beam expansion module and the first light spot shaping module, the light spot corresponding to the illumination light beam is shaped into the line illumination light spot;

[0052] The second light spot shaping module is controlled to be cut out, so that the second light spot shaping module cannot shape the linear illumination light spot.

[0053] Optionally, the illumination assembly comprises a spatial light modulator.

[0054] Optionally, the lighting assembly includes a digital micromirror device.

[0055] On the other hand, a computer-readable storage medium is provided, wherein the storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the lighting mode switching method or the detection method described above are implemented.

[0056] On the other hand, a computer program product comprising instructions is provided. When the instructions are executed on a computer, the computer is caused to execute the steps of the lighting mode switching method or the detection method described above.

[0057] The technical solution provided by this application can at least bring the following beneficial effects:

[0058] The present application controls the lighting mode to switch to the first lighting mode in response to the first signal when the detection system needs to focus, so as to achieve uniform illumination on the object surface, thereby accurately obtaining the image quality signal of the dot matrix within the full field of view, thereby improving the focusing progress; when the detection system is focused and the pupil filter adaptation is to be performed on the object to be tested, the lighting mode is controlled to switch to the second lighting mode in response to the second signal to achieve local illumination on the object surface, thereby achieving precise illumination of the local area to avoid interference from the diffraction order of the non-focus area, thereby improving the detection sensitivity of the specific focus area; when the pupil filter adaptation is completed and the detection system is to scan and image the object to be tested, the third signal can be received and the lighting mode can be controlled to switch to the third lighting mode to achieve linear illumination of the object to be tested, thereby achieving efficient scanning imaging of the object to be tested. In summary, the method proposed in the present application can switch the lighting mode according to different working scenarios, thereby meeting the lighting requirements in different working scenarios, thereby improving the detection accuracy and detection efficiency of the detection system, and achieving improved detection performance.

[0059] Furthermore, a reference curve is determined based on the multiple image energy concentration values ​​and the corresponding height distances of multiple reference images. This allows the target height distance to be directly determined from the reference curve in subsequent processes. Furthermore, using the average of the multiple region energy concentration values ​​as the image energy concentration value corresponding to the reference image can improve the accuracy of the determined target height distance. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 A schematic diagram of the structure of a detection system provided in an embodiment of the present application;

[0061] Figure 2 A schematic structural diagram of a loading platform provided in an embodiment of the present application;

[0062] Figure 3 A schematic diagram of the structure of another detection system provided in an embodiment of the present application;

[0063] Figure 4A schematic diagram showing the positional relationship of components in an illumination assembly and a light spot projected onto a stage provided in an embodiment of the present application;

[0064] Figure 5 A schematic diagram showing the positional relationship of components in another lighting assembly provided in an embodiment of the present application and the light spot projected onto the stage;

[0065] Figure 6 A schematic diagram showing the positional relationship of components in yet another lighting assembly provided in an embodiment of the present application and the light spot projected onto the stage;

[0066] Figure 7 A flowchart of a lighting mode switching method provided in an embodiment of the present application;

[0067] Figure 8 A schematic diagram of a reference image provided in an embodiment of the present application;

[0068] Figure 9 A schematic diagram of a region of interest provided in an embodiment of the present application;

[0069] Figure 10 A schematic diagram of a reference curve graph provided in an embodiment of the present application;

[0070] Figure 11 A flow chart of a detection method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0071] The present invention will be further described in detail below by means of specific embodiments in conjunction with the accompanying drawings. Similar elements in different embodiments are numbered with associated similar elements. In the following embodiments, many detailed descriptions are provided to enable the present application to be better understood. However, those skilled in the art will readily appreciate that some of the features may be omitted in different circumstances, or may be replaced by other elements, materials, or methods. In some cases, some operations related to the present application are not shown or described in the specification. This is to avoid the core portion of the present application being overwhelmed by excessive descriptions, and for those skilled in the art, it is not necessary to describe these related operations in detail. They will fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0072] In addition, the features, operations, or characteristics described in the specification may be combined in any appropriate manner to form various embodiments. Furthermore, the steps or actions in the method description may be reordered or adjusted in a manner readily apparent to those skilled in the art. Therefore, the various sequences in the specification and drawings are provided solely for the purpose of clearly describing a particular embodiment and are not intended to be mandatory, unless otherwise specified.

[0073] Component numbers used herein, such as "first" and "second," are used solely to distinguish the components being described and do not convey any sequential or technical meaning. References to "connection" and "coupling" herein, unless otherwise specified, include both direct and indirect connections (couplings).

[0074] Before explaining in detail the lighting mode switching method, detection method, detection system and storage medium provided in the embodiments of the present application, the application scenarios and implementation environment of the embodiments of the present application are first introduced.

[0075] In the inspection process of semiconductors such as wafers, there are multiple work scenarios. Adapting the corresponding lighting conditions for different work scenarios can optimize the effect of each work process, thereby improving the detection accuracy of the detection system. Therefore, in an embodiment of the present application, first, in the first lighting mode, an initial follow-up height calibration process is introduced before detection, and the target height distance (i.e., the optimal focal plane distance) is obtained by imaging and followed to improve image quality; secondly, in the second lighting mode, a filtering scheme is configured by optical means before detection, which can effectively suppress the signal generated by the repetitive structure in the object to be tested and improve the signal-to-noise ratio of the defect signal; then, in the third lighting mode, the object to be tested is scanned and imaged to detect the object to be tested. Through multiple modes, the lighting requirements of different work scenarios can be met, the detection accuracy and efficiency of the detection system can be improved, and the detection performance can be improved.

[0076] Please refer to Figure 1 , Figure 1 1 is a schematic diagram of a detection system provided in an embodiment of the present application. The detection system includes a stage 1, an illumination component 2, an imaging optical path component 3, a drive component 4, and a processor 5.

[0077] The stage 1 is used to carry the object to be tested and the reference object. For example, please refer to Figure 2 , Figure 2 This is a schematic diagram of the structure of a loading platform provided in an embodiment of the present application. Figure 2 As can be seen in FIG, the object carrier 1 has a first carrying area 11 and a second carrying area 12, wherein the first carrying area 11 is used to carry the object to be measured, and the second carrying area 12 is used to carry the reference object.

[0078] In some embodiments, the stage 1 is movable, and the movement of the stage 1 can drive the object to be measured and the reference object to be carried to move, thereby obtaining a test image of the object to be measured or a reference image of the reference object in a subsequent process.

[0079] In some embodiments, the stage 1 can move along a scanning direction, thereby driving the carried object to be tested to move along the scanning direction, so that the detection device can scan the entire surface of the object to be tested.

[0080] In some embodiments, the scanning direction may be an X-axis direction, a Y-axis direction, or a plane direction defined by the X-axis and the Y-axis (eg, a horizontal direction or a horizontal plane direction).

[0081] In some embodiments, the stage 1 can move along the optical axis of the objective lens 33, thereby driving the object to be measured or the reference object carried thereon to move along the optical axis of the objective lens 33. For example, the optical axis of the objective lens 33 can be the Z-axis direction (eg, the vertical direction).

[0082] Therefore, in some embodiments, the stage 1 can move along the Z-axis direction (eg, vertical direction), thereby driving the carried object to be measured or reference object to move along the Z-axis direction (eg, vertical direction).

[0083] It should be noted that the objects to be tested in the embodiments of the present application may be semiconductor products such as wafers and chips. Since there may be defects such as flaws on their surfaces, optical inspection of their surfaces is required to control the quality of the products.

[0084] The lighting assembly 2 is used to switch the lighting mode and emit a light beam to illuminate at least a portion of the area of ​​the object to be measured or at least a portion of the area of ​​the reference object carried on the stage 1. Figure 1 As can be seen in FIG, the light beam emitted by the lighting assembly 2 can be projected onto the stage, thereby illuminating at least a portion of the area of ​​the object to be measured or at least a portion of the area of ​​the reference object.

[0085] Imaging optical path assembly 3 includes a filter 31, a detection sensor 32, and an objective lens 33. Imaging optical path assembly 3 is configured to perform pupil filtering adaptation between the pupil and filter 31 and transmit a third signal after pupil filtering adaptation is complete, indicating that pupil filtering adaptation of the object under test is complete. Imaging optical path assembly 3 is also configured to optically image the object under test and a reference object on stage 1 via objective lens 33 and transmit the resulting optical signal to detection sensor 32. Detection sensor 32 is configured to convert the optical signal into an electrical signal, thereby obtaining a test image of the object under test and a reference image of the reference object.

[0086] Filter 31 is located on the pupil plane. The pupil refers to the image of an aperture in the optical path (such as a camera aperture or the edge of a microscope objective lens) that limits or controls the passage of a light beam. The pupil can restrict the angle and range of incident light, preventing interference from stray light. Pupil filter adaptation optimizes the collection efficiency of scattered light from defects corresponding to the object under test and suppresses background noise by adjusting the parameters or configuration of filter 31 at the pupil. Specifically, pupil filter adaptation selects light signals that match the scattering characteristics of the defect in the object under test (such as a specific scattering angle or wavelength) by using the shape, transmittance, and polarization characteristics of filter 31. It can also block stray light from non-defective areas of the object under test (such as scattering caused by substrate roughness) and reduce background noise. Therefore, pupil filter adaptation can improve the detection sensitivity and accuracy of the detection system.

[0087] Continuing with the above description, after pupil filtering adaptation is completed, the imaging optical path component 3 may further send a third signal, thereby enabling the processor 5 to perform corresponding operations in a subsequent process.

[0088] In some embodiments, the detection sensor 32 may be a TDI (Time Delayed and Integration) camera.

[0089] In addition, in some embodiments, please refer to Figure 1 The imaging optical path component 3 also includes a tube lens system 34, which is used to image the object to be measured or the reference object onto the detection sensor 32. That is, after the objective lens 33 collects light from the surface of the object to be measured or the reference object, the tube lens system 34 can focus the light onto the detection sensor 32 for imaging.

[0090] It should be noted that, in addition to the filter 31, the detection sensor 32 and the objective lens 33, the imaging optical path component 3 may also include other components, such as other optical devices arranged in the optical path between the detection sensor 32 and the objective lens 33, such as a collimating lens or even a filter, a spectrometer, etc.

[0091] The drive assembly 4 is used to drive the relative movement of the stage 1 and the objective lens 33, and to drive the illumination assembly 2 to switch the illumination mode. The drive assembly 4 can drive the stage 1 to move while the objective lens 33 remains stationary, or the drive assembly 4 can drive the objective lens 33 to move while the stage 1 remains stationary, or the drive assembly 4 can drive both the stage 1 and the objective lens 33.

[0092] For example, the driving component 4 drives the stage 1 and the objective lens 33 to move relative to each other along the scanning direction. The driving component 4 may drive the stage 1 to move along the scanning direction while the objective lens 33 remains stationary, or the driving component 4 drives the objective lens 33 to move along the scanning direction while the stage 1 remains stationary, or the driving component 4 drives the stage 1 to move and drives the objective lens 33 to move to achieve relative movement of the two along the scanning direction.

[0093] As another example, the driving component 4 drives the objective stage 1 and the objective lens 33 to move relative to each other along the optical axis direction of the objective lens 33. The driving component 4 may drive the objective stage 1 to move along the optical axis direction while the objective lens 33 remains stationary, or the driving component 4 drives the objective lens 33 to move along the optical axis direction while the objective stage 1 remains stationary, or the driving component 4 drives the objective stage 1 to move and drives the objective lens 33 to move so as to achieve relative movement of the two along the optical axis direction.

[0094] Therefore, the driving component 4 drives the objective lens 33 to move relative to each other along the Z-axis direction (for example, the vertical direction). The driving component 4 may drive the objective lens 33 to move along the Z-axis direction (for example, the vertical direction) while the objective lens 33 remains stationary, or the driving component 4 drives the objective lens 33 to move along the Z-axis direction (for example, the vertical direction) while the objective lens 33 remains stationary, or the driving component 4 drives the objective lens 33 to move along the Z-axis direction (for example, the vertical direction) while the objective lens 33 remains stationary, or the driving component 4 drives the objective lens 33 to move and drives the objective lens 33 to move so as to achieve relative movement of the two along the Z-axis direction (for example, the vertical direction).

[0095] Furthermore, in some embodiments, the lighting assembly 2 includes multiple components. When the multiple components are in different positions, the lighting assembly 2 corresponds to different lighting modes. Therefore, in order for the lighting assembly 2 to switch between lighting modes, the driving assembly needs to drive the multiple components in the lighting assembly 2 to change their positions, thereby enabling the lighting assembly to switch between lighting modes.

[0096] In some embodiments, the driving component 4 can be implemented based on driving components such as piezoelectric, servo motor, DD motor, etc.

[0097] The processor 5 includes but is not limited to a central processing unit (CPU), a microcontroller unit (MCU), a field-programmable gate array (FPGA), and a digital signal processing (DSP), etc., which are devices used to interpret computer instructions and process data in computer software.

[0098] In some embodiments, the processor 5 is capable of executing various computer applications in the non-transitory computer-readable storage medium, thereby performing the corresponding steps and methods. For example, the processor 5 can be implemented by software, hardware, firmware, or a combination thereof, and can use at least one of a circuit, a single or multiple application-specific integrated circuit (ASIC), a digital signal processor (DSP), a digital signal processing device (DSPD), a programmable logic device (PLD), a field programmable gate array (FPGA), a central processing unit (CPU), a controller, a microcontroller, and a microprocessor, so that the processor 5 can execute some or all of the steps, or any combination of the steps, of the lighting mode switching method in various embodiments of the present application, or execute some or all of the steps, or any combination of the steps, of the detection method in various embodiments of the present application.

[0099] In some embodiments, please refer to Figure 3 The lighting assembly 2 includes: a light source module 21 for emitting an illumination beam; a beam expanding module 22 for adjusting the illumination beam; a first light spot shaping module 23 for adjusting the light spot corresponding to the illumination beam passing through the beam expanding module 22 to obtain a line illumination spot or a surface illumination spot; and a second light spot shaping module 24 for shaping the light spot into a local illumination spot.

[0100] In some embodiments, please refer to Figure 3 The beam expansion module 22 includes a beam expansion lens group 221, which can adjust the size and characteristics of the illumination light beam to ensure that the illumination light field meets the detection requirements of high resolution, high uniformity and low noise.

[0101] In addition, in some embodiments, the beam expander group 221 is composed of one or more pairs of lenses (or reflectors). By adjusting the divergence angle and magnification of the illumination light beam, the diameter of the illumination light beam can be expanded, that is, the incident narrow light beam is expanded into a parallel light beam with a larger diameter; the divergence angle can be compressed, that is, the divergence of the illumination light beam is reduced and the collimation is improved; and wavefront control can be achieved, that is, the wavefront distortion (such as spherical aberration and astigmatism) of the illumination light beam is corrected, thereby optimizing the uniformity of the light field.

[0102] Continuing with the above description, the first light spot shaping module 23 is used to adjust the light spot corresponding to the illumination light beam passing through the beam expansion module 22 to obtain a line illumination spot or a surface illumination spot. That is, when the first light spot shaping module 23 cuts in, that is, when the illumination light beam passing through the beam expansion module 22 can pass through the first light spot shaping module 23, a line illumination spot or a surface illumination spot can be obtained according to the emission angle and magnification of the illumination light beam.

[0103] It should be noted that the light source module 21 may include any one of an LED (Light Emitting Diode), a xenon lamp, a mercury lamp, a halogen lamp, a laser lamp, a laser plasma lamp, and a laser-driven white light source lamp, so the illumination beam may be white light, colored light, or laser.

[0104] In some embodiments, the second light spot shaping module 24 includes a line light spot modulator. When the line light spot modulator cuts in, that is, when the light spot passes through the line light spot modulator, the line light spot modulator can shape the light spot into a local illumination light spot.

[0105] In some embodiments, please refer to Figure 4 , Figure 4 This is a schematic diagram of the positional relationship of the various components in an illumination assembly provided in an embodiment of the present application and the light spot projected onto the stage. The specific implementation process of the processor 5 controlling the illumination assembly 2 to switch the illumination mode to the first illumination mode includes: controlling the light source module 21 to emit an illumination light beam; changing the divergence angle and magnification of the illumination light beam passing through the beam expanding module 22 by adjusting the beam expanding module 22 to obtain a first output light beam; adjusting the light spot corresponding to the first output light beam to a surface illumination light spot through the first light spot shaping module 23; and controlling the second light spot shaping module 24 to be cut out so that the second light spot shaping module 24 cannot shape the surface illumination light spot.

[0106] Based on the above description, it can be seen that the beam expander assembly 221 can expand the diameter of the illumination beam by changing the divergence angle and magnification of the illumination beam, and the first light spot shaping module 23 can adjust the light spot corresponding to the illumination beam passing through the beam expander module 22 to obtain a surface illumination spot. Therefore, the processor 5 can obtain the desired first output light beam by appropriately adjusting the beam expander module. Thereafter, the first light spot shaping module 23 can obtain a surface illumination spot based on the emission angle and magnification corresponding to the first output light beam.

[0107] Continuing with the above description, since the first illumination mode corresponds to a surface illumination spot, a surface illumination spot can be obtained after passing through the first light spot shaping module 23. Therefore, the processor 5 needs to control the second light spot shaping module 24 to be cut out to avoid the second light spot shaping module 24 interfering with the surface illumination spot.

[0108] In some embodiments, please refer to Figure 5 , Figure 5 This is a schematic diagram of the positional relationship of the components in another lighting assembly provided in an embodiment of the present application and the light spot projected onto the stage. The specific implementation of the processor 5 controlling the lighting assembly 2 to switch the lighting mode to the second lighting mode includes: controlling the light source module 21 to emit an illumination light beam; changing the divergence angle and magnification of the illumination light beam passing through the beam expanding module 22 by adjusting the beam expanding module 22 to obtain a second output light beam; adjusting the light spot corresponding to the second output light beam to a surface illumination light spot through the first light spot shaping module 23; controlling the second light spot shaping module 24 to cut in, so that the second light spot shaping module 24 shapes the surface illumination light spot into a local illumination light spot.

[0109] Based on the above description, it can be seen that the beam expander assembly 221 can expand the diameter of the illumination beam by changing the divergence angle and magnification of the illumination beam, and the first spot shaping module 23 can adjust the spot corresponding to the illumination beam passing through the beam expander module 22 to obtain a surface illumination spot or a line illumination spot. Therefore, the processor 5 can obtain the desired second output beam by appropriately adjusting the beam expander module.

[0110] Continuing with the above description, since the second illumination mode corresponds to a local illumination spot, only a surface illumination spot or a line illumination spot can be obtained after passing through the first light spot shaping module 23, and the second light spot shaping module 24 can shape the spot into a local illumination spot. Therefore, the processor 5 needs to control the second light spot shaping module 24 to cut in so that the second light spot shaping module 24 can shape the surface illumination spot into a local illumination spot.

[0111] In some embodiments, please refer to Figure 6 , Figure 6 This is a schematic diagram of the positional relationship of the components in another illumination assembly provided in an embodiment of the present application and the light spot projected onto the stage. The processor 5 controls the illumination assembly 2 to switch the illumination mode to the third illumination mode, including: controlling the light source module 21 to emit an illumination beam; shaping the light spot corresponding to the illumination beam into a line illumination spot by adjusting the beam expansion module 22 and the first light spot shaping module 23; and controlling the second light spot shaping module 24 to be cut out so that the second light spot shaping module 24 cannot shape the line illumination spot.

[0112] Based on the above description, it can be seen that the beam expander assembly 221 can expand the diameter of the illumination beam by changing the divergence angle and magnification of the illumination beam, and the first spot shaping module 23 can adjust the spot corresponding to the illumination beam passing through the beam expander module 22 to obtain a linear illumination spot. Therefore, the processor 5 obtains the linear illumination spot by appropriately adjusting the beam expander module and the first spot shaping module 23.

[0113] Continuing with the above description, since the third illumination mode corresponds to a linear illumination spot, the processor 5 needs to control the second light spot shaping module 24 to be switched off to avoid interference with the linear illumination spot by the second light spot shaping module 24 .

[0114] In addition, in some embodiments, the default illumination mode when the detection system is started is the third illumination mode, that is, the illumination spot at this time is a line illumination spot.

[0115] In some embodiments, before using the detection system to inspect an object under test, technicians can simulate and analyze the illumination beam of light source module 21 and the resulting spot shape, thereby adjusting beam expansion module 22 and customizing a suitable first spot shaping module 23 to shape the illumination beam with a fixed waist radius, thereby forming a linear illumination spot on the object surface (e.g., the inspection area of ​​the object under test on stage 1, or at least a portion of a reference object on stage 1). This allows the default illumination mode upon startup of the detection system to be the third illumination mode.

[0116] It should be noted that the first light spot shaping module 23 may include a cylindrical mirror, a lens, a diffractive optical element or other components, which is not limited in the embodiment of the present application.

[0117] Continuing with the above description, on the basis of the third illumination mode, if the illumination mode needs to be switched to the first illumination mode, the processor 5 only needs to adjust the beam expander group 221 on the basis of the third illumination mode to change the divergence angle and magnification of the illumination light beam to achieve modulation of the illumination spot on the object surface illumination area, improve the uniformity of the illumination spot in the full field of view of the imaging optical path component, and obtain a surface illumination spot, that is, switch the illumination mode of the illumination component 2 from the third illumination mode to the first illumination mode.

[0118] In some embodiments, technicians can customize the second light spot shaping module 24 according to the needs of local lighting. In this way, the first light spot shaping module 23 is used in combination with the first light spot shaping module 23 to achieve local lighting, that is, to obtain a local lighting spot.

[0119] Therefore, based on the third lighting mode, if the lighting mode needs to be switched to the second lighting mode, the processor 5 only needs to control the second light spot shaping module 24 to cut in, so as to obtain a local lighting spot, that is, to switch the lighting mode of the lighting component 2 from the third lighting mode to the second lighting mode.

[0120] That is, when setting up the detection system, technicians need to adjust the beam expansion module 22 based on the shaping effect of the first light spot shaping module 23 to achieve optimal narrow-line illumination on the object surface, that is, to make the light spot on the object surface a linear illumination spot, which is currently the third illumination mode. Based on the third illumination mode, by adjusting the beam expansion module 22, such as adjusting the relative position of the beam expansion lens group 221 in the beam expansion module 22, the divergence angle and magnification of the illumination beam are changed to achieve surface illumination on the object surface, that is, to make the light spot on the object surface a surface illumination spot, thereby switching the illumination mode to the first illumination mode. At the same time, based on the third illumination mode, cutting in the second shaping module and adjusting the alignment can make the linear illumination spot converge along the long side direction, achieving precise illumination of a local area on the object surface, that is, to make the light spot on the object surface a local illumination spot, thereby switching the illumination mode to the second illumination mode.

[0121] In some embodiments, the illumination assembly 2 includes a spatial light modulator (SLM), allowing the processor 5 to switch the illumination mode of the illumination assembly 2 using this SLM. A SLM is a device capable of real-time dynamic control of the spatial distribution characteristics of light waves (such as amplitude, phase, polarization state, or wavelength). Using electrical signals, optical signals, or other external stimuli, it adjusts the properties of light point by point or region by region on a two-dimensional plane, thereby achieving complex light field manipulation. The SLM enables continuous variation of the illumination spot within a certain range.

[0122] In some embodiments, the lighting assembly 2 includes a digital micromirror device (DMD). The processor 5 can use the DMD to switch the lighting mode of the lighting assembly 2. A DMD is an optical modulation device based on micro-electromechanical system (MEMS) technology. It achieves binary spatial modulation ("on" or "off") of the light field by controlling the mechanical deflection state of millions of micro-mirrors. The DMD can achieve continuous variation of the illumination spot within a certain spatial resolution.

[0123] Next, a lighting mode switching method provided in an embodiment of the present application is explained in detail.

[0124] Figure 7 This is a flow chart of a lighting mode switching method provided by an embodiment of the present application, which is applied to the processor in the above detection system. Figure 7 , the method comprises the following steps:

[0125] Step 701: In response to a first signal, control the illumination mode to switch to the first illumination mode to uniformly illuminate the reference object carried on the stage. The first signal is used to indicate that the detection system needs to perform focus search.

[0126] In some embodiments, the technician can send a first signal by clicking on the host computer to instruct to start the detection process, thereby controlling the lighting mode to switch to the first lighting mode in response to the first signal.

[0127] Before inspecting the object to be tested, a focus search is performed. During this process, uniform illumination is applied across the entire field of view to avoid large grayscale deviations in the dot matrix image due to uneven illumination. This allows for accurate image quality information of the dot matrix across the entire field of view, allowing for accurate reference images of the reference object in subsequent processes. This improves focus accuracy, specifically, the accuracy of target height and distance determination in subsequent processes. Therefore, the illumination spot of the first illumination mode can be a surface illumination spot.

[0128] It should be noted that the above description is based on the light spot of the first lighting mode as the surface lighting light spot, or, in application, the first lighting mode may also correspond to other light spots, which is not limited in the embodiments of the present application.

[0129] In some embodiments, after controlling the lighting mode to switch to the first lighting mode in response to the first signal, the stage carrying the reference object and the object to be measured and the objective lens can also be controlled to move relative to each other in the vertical direction, so that the reference object carried on the stage and the objective lens are at multiple different distances in the vertical direction. Then, multiple reference images are received, and the multiple reference images are images obtained by photographing the reference object at each distance. Then, based on the multiple reference images, the target height distance is determined. The target height distance is used to determine the initial height distance between the stage or the object to be measured and the objective lens when scanning the object to be measured.

[0130] Since the graphic types corresponding to different areas of the object to be tested may be different when testing the object to be tested, it is difficult to find a fixed graphic feature as the object of focus imaging. Therefore, a second carrying area for carrying a reference object in addition to the first carrying area for carrying the object to be tested can be added to the stage to carry out the subsequent focus-finding process.

[0131] In some embodiments, for each of the multiple reference images: multiple regions of interest (i.e., ROIs) in the reference image can be determined, and then, regional energy concentration values ​​corresponding to the multiple regions of interest are determined, and based on the multiple regional energy concentration values, the image energy concentration value corresponding to the reference image is determined, and then, based on the image energy concentration values ​​corresponding to the multiple reference images and the height distances corresponding to the multiple reference images, the target height distance is determined.

[0132] That is to say, after obtaining the multiple reference images, it is necessary to determine the corresponding multiple focus areas for each reference image, and determine the corresponding regional energy concentration value for each focus area in the multiple focus areas to obtain the multiple regional energy concentration values ​​corresponding to each reference image, and then determine the image energy concentration value corresponding to each reference image based on the multiple regional energy concentration values.

[0133] As an example, see Figure 8 , Figure 8 is a schematic diagram of a reference image provided by an embodiment of the present application. Figure 8 It can be seen that the reference image includes multiple areas, and a total of 9 areas in the dotted box are selected as the focus areas from the multiple areas. Afterwards, it is necessary to determine the regional energy concentration values ​​corresponding to these 9 areas, and 9 regional energy concentration values ​​can be obtained. Therefore, the image energy concentration value corresponding to the reference image can be determined based on these 9 regional energy concentration values.

[0134] It should be noted that the above description is based on the selection of 9 regions of interest, or, in application, any more or fewer regions in the reference image may be selected as regions of interest according to circumstances. This embodiment of the present application does not limit this.

[0135] In some embodiments, the regional energy concentration value corresponding to each of the plurality of regions of interest may be determined according to the following steps (1)-(3);

[0136] (1) Determine the central pixel in the focus area, which is the pixel with the largest grayscale value in the focus area.

[0137] That is, the pixel with the largest grayscale value in the focus area can be determined as the center pixel. For example, please refer to Figure 9 , Figure 9 is a schematic diagram of a region of interest provided in an embodiment of the present application, wherein the central pixel is Figure 9 The gray area A0 in the image.

[0138] (2) With the central pixel as the center, determine the first sub-region, the second sub-region, and the third sub-region in the region of interest. The first sub-region is located outside the central pixel, the second sub-region is located outside the first sub-region, and the third sub-region is the other region in the region of interest that is located outside the second sub-region.

[0139] As an example, see Figure 9 , the first sub-region is Figure 9 The white area A1 in the second sub-area is Figure 9 The shaded area A2 in the figure is the third sub-area. Figure 9 The black area A3 in the figure.

[0140] It should be noted that Figure 9 The sizes of the first sub-area, the second sub-area, and the third sub-area are merely examples, and in actual applications, the sizes of the first sub-area, the second sub-area, and the third sub-area may be modified according to circumstances. This embodiment of the present application does not limit this.

[0141] (3) Based on the first sub-region, the second sub-region, and the third sub-region, the corresponding regional energy concentration values ​​are determined.

[0142] In some embodiments, the following steps ae may be performed to determine the corresponding regional energy concentration values ​​based on the first sub-region, the second sub-region, and the third sub-region;

[0143] a. Determine an average noise based on the pixels in the second sub-region and the pixels in the third sub-region.

[0144] Because both the second sub-region and the second sub-region include multiple pixels, it is necessary to calculate the noise value of each of these multiple pixels. For example, the noise value of each pixel is the difference between the pixel in the noisy image and the pixel in the region of interest. A noisy image is an image that exhibits unexpected random variations in pixel values ​​due to various interferences. Such images typically contain abnormal brightness or color fluctuations that do not originate from the original scene.

[0145] It should be noted that the above description is based on the method of determining the noise of each pixel according to the difference between the noisy image and the region of interest. Alternatively, in applications, the noise of each pixel may be determined by other methods.

[0146] It should be noted that after obtaining the noise corresponding to multiple pixels in the second sub-region and the third sub-region, the multiple noises can be averaged, and the obtained average value can be determined as the average noise. Alternatively, the standard deviation or median of the multiple noises can be calculated to determine the average noise. This embodiment of the present application is not limited to this.

[0147] b. Determine a plurality of grayscale pixels in the first subregion, wherein the plurality of grayscale pixels include a first pixel in the first subregion having the largest grayscale value and at least one pixel having a grayscale value sequentially smaller than the grayscale value of the first pixel.

[0148] In other words, it is necessary to determine multiple pixels with the largest grayscale values ​​in the first sub-region, that is, the multiple grayscale pixels include the first pixel with the largest grayscale value in the first sub-region and at least one pixel whose grayscale value is successively smaller than the grayscale value of the first pixel. As an example, assuming that there are pixels P1, P2, P3, P4, P5, and P6 in the first sub-region, and that pixel P1 is the pixel with the largest grayscale value in the first sub-region, and the grayscale values ​​of pixels P2, P3, P4, P5, and P6 decrease in order; if it is necessary to select four grayscale pixels, then pixels P1, P2, P3, and P4 can be determined as grayscale pixels.

[0149] c. Determine a first energy value based on the plurality of grayscale pixels and the average noise.

[0150] In some embodiments, average noise may be deducted from each of the plurality of grayscale pixels to obtain a plurality of grayscale pixels after average noise deduction, and then the grayscale values ​​of the plurality of grayscale pixels after average noise deduction are added to obtain the first energy value.

[0151] After determining the plurality of grayscale pixels and the average noise, the average noise is subtracted from each of the plurality of grayscale pixels to reduce noise interference and thereby improve the accuracy of the determined regional energy concentration value. Then, for each of the plurality of grayscale pixels after subtracting the average noise, a grayscale value is determined to obtain the grayscale values ​​corresponding to the plurality of grayscale pixels after subtracting the average noise. These grayscale values ​​are then summed to determine the first energy value.

[0152] d. Determine a second energy value based on the pixels in the second sub-region and the average noise.

[0153] In some embodiments, average noise may be deducted from each pixel in the second sub-region to obtain a plurality of pixels after average noise deduction, and then the grayscale values ​​of the plurality of pixels after average noise deduction are added to obtain the second energy value.

[0154] After determining the noise, the average noise can be deducted from each pixel in the second subregion to reduce noise interference and improve the accuracy of the subsequently determined regional energy concentration value. Then, for all pixels in the second subregion after deducting the average noise, the grayscale value of each pixel is determined to obtain the grayscale value of each pixel in the second subregion. These multiple grayscale values ​​are then added together to determine the second energy value.

[0155] e. Determine a regional energy concentration value based on the first energy value and the second energy value.

[0156] In some embodiments, after obtaining the first energy value and the second energy value, the ratio of the first energy value to the second energy value may be determined as the regional energy concentration value.

[0157] It should be noted that the above description is based on determining the ratio of the first energy value to the second energy value as the regional energy concentration value, or in application, the regional energy concentration value may be determined by other methods, which are not limited in the embodiments of the present application.

[0158] For each region of interest, after determining the regional energy concentration value corresponding to each region of interest according to the above steps ae and obtaining multiple regional energy concentration values, the average value of the multiple regional energy concentration values ​​can be used as the image energy concentration value corresponding to the corresponding reference image.

[0159] Continuing with the above description, since the image energy concentration value of each reference image in the multiple reference images is the average of the regional energy concentration values ​​corresponding to the multiple focus areas in the reference image, in the subsequent process, the target height distance is determined according to the energy concentration values ​​corresponding to the multiple reference images respectively, which can improve the accuracy of the determined target height distance and perform more precise focusing, thereby providing imaging quality when detecting the object to be tested in the subsequent process.

[0160] In some embodiments, in order to quickly determine the target height distance and still be able to obtain the target height distance in subsequent processes, a reference curve graph can be obtained based on multiple image energy concentration values ​​and the height distances corresponding to multiple reference images; the height distance corresponding to the largest image energy concentration value in the reference curve graph is determined as the target height distance.

[0161] Based on the above description, it is possible to determine the image energy concentration value corresponding to each reference image, thereby obtaining multiple image energy concentration values. Furthermore, since these multiple reference images are obtained by photographing the reference object on the stage at different height distances, it can be seen that each of the multiple reference images has a corresponding height distance and image energy concentration value. Therefore, a reference curve can be determined based on the image energy concentration values ​​and height distances corresponding to each of the multiple reference images.

[0162] After obtaining the reference curve graph, the point with the highest image energy concentration value in the reference curve graph corresponds to the highest imaging quality. Therefore, the height distance corresponding to the point with the highest image energy concentration value can be determined as the target height distance.

[0163] As an example, see Figure 10 , Figure 10Schematic diagram of a reference curve provided by an embodiment of the present application, wherein the horizontal axis of the reference curve is the height distance, and the vertical axis is the image energy concentration value. Figure 10 It can be seen that when the height distance is X, the corresponding image energy concentration value is the highest, and the image energy concentration value is Y. Therefore, it means that the corresponding imaging quality is the highest when the height distance is X. Therefore, the height distance X can be determined as the target height distance.

[0164] In some embodiments, after determining the target height distance based on the multiple reference images, the stage can also be controlled to move to a corresponding height in the vertical direction according to the target height distance. Then, the height value of the upper surface of the reference object when the stage is at this height is obtained as the target height value. The target height value is used to indicate the height value that the upper surface of the test area corresponding to the object to be tested needs to be at when it is in the initial scanning position.

[0165] That is to say, it may happen that the bottom surfaces of the first supporting area and the second supporting area of ​​the stage are not in the same horizontal plane, or the thickness of the object to be measured is different from that of the reference object, resulting in the upper surface of the object to be measured and the upper surface of the reference object not being in the same horizontal plane. Therefore, after determining the target height, it is also necessary to obtain the height value of the upper surface of the reference object when the stage is at this height as the target height value.

[0166] Step 702: In response to the second signal, control the illumination mode to switch to the second illumination mode to illuminate the target area and perform pupil filtering adaptation on the object to be measured carried on the stage. The second signal is used to indicate that focusing is completed, and the target area is a partial area of ​​the object to be measured.

[0167] In some embodiments, after focus search is completed, a second signal is triggered, thereby controlling the lighting mode to switch to the second lighting mode in response to the second signal.

[0168] During pupil filter adaptation, the second illumination mode's illumination spot can be localized, prioritizing specific areas of interest. This allows for precise illumination of these areas, avoiding interference from diffraction orders in areas outside of interest, and prioritizing pupil filter adaptation in these areas. This improves detection sensitivity in these areas.

[0169] It should be noted that the above description is based on the light spot of the second lighting mode as a local lighting light spot, or, in application, the second lighting mode may also correspond to other light spots, which is not limited in the embodiments of the present application.

[0170] Step 703: Receive a third signal and control the illumination mode to switch to a third illumination mode to perform scanning imaging on the object to be measured. The third signal is used to indicate that pupil filter adaptation of the object to be measured is completed.

[0171] After pupil filter adaptation is completed, a third signal may be received, indicating that pupil filter adaptation of the object to be measured has been completed and scanning imaging of the object to be measured is possible. Therefore, after receiving the third signal, the illumination mode needs to be switched to the third illumination mode.

[0172] Since a line scanning image acquisition mode needs to be matched when scanning and inspecting the object to be tested to achieve efficient scanning imaging of the object to be tested, the illumination spot of the third illumination mode can be a line illumination spot.

[0173] It should be noted that the above description is based on the light spot of the third lighting mode as a linear lighting light spot, or, in application, the third lighting mode may also correspond to other light spots, which is not limited in the present embodiment.

[0174] The embodiment of the present application controls the lighting mode to switch to the first lighting mode in response to the first signal when the detection system needs to focus, so as to achieve uniform illumination on the object surface, thereby accurately obtaining the image quality signal of the dot matrix within the full field of view, thereby improving the focusing progress; when the detection system is focused and the pupil filter is to be adapted for the object to be tested, the embodiment of the present application controls the lighting mode to switch to the second lighting mode in response to the second signal, so as to achieve local illumination on the object surface, thereby achieving precise illumination of the local area, thereby avoiding interference from diffraction orders of non-interest areas, and improving the detection sensitivity of specific interest areas; when the detection system is pupil filter adapted and the object to be tested is to be scanned and imaged, the embodiment of the present application controls the lighting mode to switch to the third lighting mode in response to the first signal, so as to achieve linear illumination of the object to be tested, thereby achieving efficient scanning imaging of the object to be tested. In summary, the method proposed in the present application can switch the lighting mode according to different working scenarios, thereby meeting the lighting requirements in different working scenarios, thereby improving the detection accuracy and detection efficiency of the detection system, and achieving improved detection performance. In addition, by introducing a reference object and determining the target height distance based on multiple reference images corresponding to the reference object, the influence of environmental conditions or the pattern of the object to be measured can be avoided, thereby improving the focus accuracy.

[0175] Figure 11 This is a flow chart of a detection method provided in an embodiment of the present application, which is applied to the processor in the above detection device. Figure 11 , the method comprises the following steps:

[0176] Step 1101: Under the third illumination mode, control the imaging of the object to be measured to obtain an image of the object to be measured corresponding to the area to be measured at the current scanning position of the object to be measured.

[0177] In some embodiments, the object to be measured corresponds to different areas to be measured at different scanning positions. By imaging the different areas to be measured of the object to be measured at multiple different scanning positions, scanning and imaging of the surface of the object to be measured can be completed.

[0178] Step 1102: Detect the area to be tested based on the image to be tested.

[0179] For example, defect detection may be performed on the area to be tested based on the image to be tested.

[0180] It is understandable that step 1102 may be based on an existing or future detection algorithm to perform detection of the corresponding area to be tested based on the image to be tested.

[0181] The embodiment of the present application can improve detection efficiency by detecting the object to be detected under the third lighting mode.

[0182] This document is described with reference to various exemplary embodiments. However, those skilled in the art will recognize that changes and modifications may be made to the exemplary embodiments without departing from the scope of this document. For example, the various operational steps and components used to perform the operational steps may be implemented in different ways (e.g., one or more steps may be deleted, modified, or incorporated into other steps) depending on the specific application or any number of cost functions associated with the operation of the system.

[0183] In the above-described embodiments, all or part of the embodiments may be implemented using software, hardware, firmware, or any combination thereof. Furthermore, as will be appreciated by those skilled in the art, the principles herein may be embodied in a computer program product on a computer-readable storage medium pre-installed with computer-readable program code. Any tangible, non-transitory computer-readable storage medium may be used, including magnetic storage devices (hard disks, floppy disks, etc.), optical storage devices (CD-ROMs, DVDs, Blue Ray disks, etc.), flash memory, and / or the like. These computer program instructions may be loaded onto a general-purpose computer, a special-purpose computer, or other programmable data processing device to form a machine, such that the instructions executed on the computer or other programmable data processing device generate a device that implements a specified function. These computer program instructions may also be stored in a computer-readable memory, which may instruct the computer or other programmable data processing device to operate in a specific manner, such that the instructions stored in the computer-readable memory may form an article of manufacture including a device that implements a specified function. The computer program instructions may also be loaded onto a computer or other programmable data processing device to execute a series of operational steps on the computer or other programmable device to generate a computer-implemented process, such that the instructions executed on the computer or other programmable device provide the steps for implementing the specified function.

[0184] Although the principles of this invention have been shown in various embodiments, many modifications of structure, arrangement, proportion, elements, materials and components that are particularly suitable for specific environments and operational requirements can be used without departing from the principles and scope of this invention. The above modifications and other changes or amendments are intended to be included within the scope of this invention.

[0185] The foregoing detailed description has been described with reference to various embodiments. However, those skilled in the art will recognize that various modifications and changes can be made without departing from the scope of this disclosure. Therefore, the present disclosure will be considered in an illustrative rather than a restrictive sense, and all such modifications will be included within its scope. Similarly, the advantages, other advantages and solutions to the problems of the various embodiments have been described above. However, the benefits, advantages, solutions to the problems and any elements that can produce these, or make them more specific, should not be interpreted as critical, required or necessary. The term "comprising" and any other variants used in this article are all non-exclusive inclusions, so that a process, method, article or device that includes a list of elements includes not only these elements, but also other elements that are not explicitly listed or do not belong to the process, method, system, article or device. In addition, the term "coupled" and any other variants used in this article refer to physical connections, electrical connections, magnetic connections, optical connections, communication connections, functional connections and / or any other connections.

[0186] Those skilled in the art will recognize that many changes can be made to the details of the above embodiments without departing from the basic principles of the invention. Therefore, the scope of the present invention should be determined solely by the claims.

Claims

1. A lighting mode switching method, characterized in that: The method comprises: In response to a first signal, controlling the illumination mode to switch to a first illumination mode to uniformly illuminate a reference object carried on the stage, wherein the first signal is used to indicate that the detection system needs to perform focus search based on the reference object, and the illumination spot of the first illumination mode is a surface illumination spot; In response to a second signal, controlling the illumination mode to switch to a second illumination mode to illuminate a target area and perform pupil filtering adaptation on the object to be measured carried on the stage, wherein the second signal is used to indicate that focus search is completed, the target area is a partial area of ​​the object to be measured, and the illumination spot of the second illumination mode is a local illumination spot; A third signal is received, and the illumination mode is controlled to switch to a third illumination mode to scan and image the object to be measured. The third signal is used to indicate that pupil filtering adaptation of the object to be measured is completed. The illumination spot of the third illumination mode is a line illumination spot.

2. The lighting mode switching method according to claim 1, wherein: After controlling the lighting mode to switch to the first lighting mode in response to the first signal, the method further includes: Controlling the relative movement of the stage carrying the reference object and the object to be measured and the objective lens in the vertical direction so that the reference object carried on the stage and the objective lens are at multiple different distances in the vertical direction; receiving a plurality of reference images, wherein the plurality of reference images are images obtained by photographing the reference object at each of the distances; A target height distance is determined based on the multiple reference images, and the target height distance is used to determine an initial height distance between the stage or the object to be measured and the objective lens when scanning the object to be measured.

3. The lighting mode switching method according to claim 2, wherein: Determining the target height distance based on the multiple reference images includes: For each of the plurality of reference images: determining a plurality of regions of interest in the reference image; determining regional energy concentration values ​​corresponding to the plurality of regions of interest respectively; and determining an image energy concentration value corresponding to the reference image based on the plurality of regional energy concentration values; The target height distance is determined based on the image energy concentration values ​​respectively corresponding to the multiple reference images and the height distances respectively corresponding to the multiple reference images.

4. The lighting mode switching method according to claim 3, wherein: The determining, based on the plurality of regional energy concentration values, an image energy concentration value corresponding to the reference image includes: An average value of the plurality of regional energy concentration values ​​is used as the image energy concentration value corresponding to the reference image.

5. The lighting mode switching method according to claim 4, wherein: The determining the target height distance based on the image energy concentration values ​​respectively corresponding to the plurality of reference images and the height distances respectively corresponding to the plurality of reference images includes: Obtaining a reference curve graph according to the plurality of image energy concentration values ​​and the height distances respectively corresponding to the plurality of reference images; The height distance corresponding to the maximum image energy concentration value in the reference curve graph is determined as the target height distance.

6. The lighting mode switching method according to claim 2, wherein: After determining the target height distance based on the multiple reference images, the method further includes: Control the stage to move to the corresponding height in the vertical direction according to the target height distance, and obtain the height value of the upper surface of the reference object when the stage is at this height as the target height value. The target height value is used to indicate the height value that the upper surface of the test area corresponding to the object to be tested needs to be at when it is in the initial scanning position.

7. A detection method, characterized in that: The method comprises: The method according to any one of claims 1 to 6, wherein, in the third illumination mode, controlling imaging of the object to be measured to obtain an image of the object to be measured corresponding to the area to be measured at the current scanning position; The area to be tested is detected based on the image to be tested.

8. A detection system, characterized in that: The system comprises: The stage is used to carry the object to be tested and the reference object; an illumination assembly, configured to switch illumination modes and illuminate at least a portion of the object to be measured or at least a portion of the reference object carried on the stage through an illumination beam; An imaging optical path component includes a pupil, a filter, a detection sensor, and an objective lens; the imaging optical path component is used to perform pupil filtering adaptation on the pupil and the filter, and to send a third signal after the pupil filtering adaptation is completed, wherein the third signal is used to indicate that the pupil filtering adaptation of the object to be measured is completed; the imaging optical path component is also used to optically image the object to be measured and the reference object on the stage through the objective lens, and transmit the optical signal obtained by imaging to the detection sensor, wherein the detection sensor is used to convert the optical signal into an electrical signal, thereby obtaining a test image of the object to be measured and a reference image of the reference object; a driving assembly, configured to drive the stage and the objective lens to move relative to each other, and to drive the lighting assembly to switch lighting modes; A processor, configured to execute the method according to any one of claims 1 to 7.

9. The detection system according to claim 8, wherein: The lighting assembly comprises: a light source module, configured to emit the illumination light beam; A beam expansion module, used to adjust the illumination beam; A first light spot shaping module is used to adjust the light spot corresponding to the illumination light beam passing through the beam expansion module to obtain a line illumination spot or a surface illumination spot; The second light spot shaping module is used to shape the light spot into a local illumination light spot.

10. The detection system according to claim 9, wherein: The processor controlling the lighting assembly to switch the lighting mode to the first lighting mode includes: Controlling the light source module to emit an illumination beam; By adjusting the beam expansion module, the divergence angle and magnification of the illumination light beam passing through the beam expansion module are changed to obtain a first output light beam; Adjusting the light spot corresponding to the first outgoing light beam into the surface illumination light spot by the first light spot shaping module; The second light spot shaping module is controlled to be cut out so that the second light spot shaping module cannot shape the surface illumination light spot.

11. The detection system according to claim 9, wherein: The processor controlling the lighting assembly to switch the lighting mode to the second lighting mode includes: Controlling the light source module to emit an illumination beam; By adjusting the beam expansion module, the divergence angle and magnification of the illumination light beam passing through the beam expansion module are changed to obtain a second output light beam; Adjusting the light spot corresponding to the second outgoing light beam into the surface illumination light spot by the first light spot shaping module; The second light spot shaping module is controlled to cut in so that the second light spot shaping module shapes the surface illumination light spot into a local illumination light spot.

12. The detection system according to claim 9, wherein: The processor controlling the lighting assembly to switch the lighting mode to the third lighting mode includes: Controlling the light source module to emit an illumination beam; By adjusting the beam expansion module and the first light spot shaping module, the light spot corresponding to the illumination light beam is shaped into the line illumination light spot; The second light spot shaping module is controlled to be cut out, so that the second light spot shaping module cannot shape the linear illumination light spot.

13. The detection system according to claim 8, wherein: The illumination assembly includes a spatial light modulator.

14. The detection system according to claim 8, wherein: The lighting assembly includes a digital micromirror device.

15. A computer-readable storage medium, characterized in that A computer program is stored on the medium, and the computer program can be executed by a processor to implement the method according to any one of claims 1 to 7.

Images