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

Abstract

The invention discloses an illumination mode switching method, a detection method, a detection system and a storage medium, and belongs to the technical field of semiconductor detection. The method comprises the steps that in response to a first signal, an illumination mode is controlled to be switched into a first illumination mode so as to perform uniform illumination on a reference object borne on an objective table, and the first signal is used for indicating that a detection system needs to perform focus searching; in response to a second signal, the illumination mode is controlled to be switched into a second illumination mode so as to illuminate the target area and perform pupil filtering adaptation on the to-be-detected object carried on the objective table, and the second signal is used for indicating that focus searching is completed; and a third signal is received, the illumination mode is controlled to be switched to a third illumination mode so as to scan and image the object to be detected, and the third signal is used for indicating that pupil filtering adaptation of the object to be detected is completed. According to the method and the device, the illumination modes can be switched for different working scenes, so that the illumination requirements in different working scenes are met, and the detection performance is improved.

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, the common method is to use a single lighting condition in different working scenes, which will reduce the detection accuracy. In addition, dark field detection systems usually detect the object to be detected directly according to the theoretical focal plane, but due to the influence of changes in ambient temperature conditions, the initial following height of the dark field detection system will change over time. Following according to the nominal focal plane may cause the object to be defocused, thereby affecting the detection effect. Summary of the invention

[0003] In view of the problems existing in the prior art, the present application provides a lighting mode switching method, a detection method, a detection system and a storage medium, which can switch the lighting mode for different working scenes, thereby meeting the lighting requirements in different working scenes and improving the detection performance. The technical solution is as follows: In one aspect, a lighting mode switching method is provided, the method comprising: In response to a first signal, controlling the illumination mode to switch to a 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; 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; A third signal is received, and the illumination mode is controlled to switch to the third illumination mode to scan and image 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.

[0004] Optionally, 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 a plurality of 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; Based on the multiple reference images, a target height distance is determined, 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.

[0005] Optionally, determining the target height distance based on the multiple reference images includes: For each reference image in the plurality of reference images: determining a plurality of focus regions in the reference image; determining regional energy concentration values ​​corresponding to the plurality of focus regions 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.

[0006] Optionally, determining the image energy concentration value corresponding to the reference image based on the multiple regional energy concentration values ​​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.

[0007] Optionally, the determining the target height distance 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 comprises: 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.

[0008] Optionally, after determining the target height distance based on the multiple reference images, the method further includes: Control the stage to move to a 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, and 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.

[0009] Optionally, the illumination spot of the first illumination mode is a surface illumination spot.

[0010] Optionally, the illumination spot of the second illumination mode is a local illumination spot.

[0011] Optionally, the illumination spot of the third illumination mode is a line illumination spot.

[0012] On the other hand, a detection method is provided, the method comprising: 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; The area to be tested is detected based on the image to be tested.

[0013] In another aspect, a detection system is provided, comprising: The stage is used to carry the object to be tested and the reference object; An illumination component, used for switching illumination modes and illuminating at least a partial area of ​​the object to be measured or at least a partial area of ​​the reference object carried on the stage through an illumination beam; An imaging optical path component, comprising 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 send a third signal after the pupil filtering adaptation is completed, 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 perform optical imaging on 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, the detection sensor is used to convert the optical signal into an electrical signal, so as to obtain a test image of the object to be measured and a reference image of the reference object; A driving assembly, used for driving the stage and the objective lens to move relative to each other, and driving the lighting assembly to switch the lighting mode; A processor is used to execute the method described in any embodiment of the present invention.

[0014] Optionally, the lighting assembly comprises: A light source module, used for emitting 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 light spot or a surface illumination light spot; The second light spot shaping module is used to shape the light spot into a local illumination light spot.

[0015] Optionally, the processor controlling the lighting component to switch the lighting mode to the first lighting mode comprises: Controlling the light source module to emit an illumination light 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; The light spot corresponding to the first outgoing light beam is adjusted to 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.

[0016] Optionally, the processor controlling the lighting component to switch the lighting mode to the second lighting mode comprises: Controlling the light source module to emit an illumination light 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; The light spot corresponding to the second outgoing light beam is adjusted to 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.

[0017] Optionally, the processor controlling the lighting component to switch the lighting mode to a third lighting mode comprises: Controlling the light source module to emit an illumination light 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 linear 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.

[0018] Optionally, the illumination assembly comprises a spatial light modulator.

[0019] Optionally, the lighting assembly comprises a digital micromirror device.

[0020] 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.

[0021] On the other hand, a computer program product comprising instructions is provided. When the instructions are executed on a computer, the computer executes the steps of the lighting mode switching method or the detection method described above.

[0022] The technical solution provided by this application can at least bring the following beneficial effects: 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 search for 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 pupil filtering is to be adapted for 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-interest area, thereby improving the detection sensitivity of the specific interest area; when the detection system pupil filtering is adapted and scanning imaging of the object to be tested is to be performed, the third signal can be received and the lighting mode can be controlled to switch to the third lighting mode to achieve line 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 for different working scenarios, thereby meeting the lighting requirements in different working scenarios, thereby improving the detection accuracy and efficiency of the detection system, and achieving improved detection performance.

[0023] In addition, a reference curve graph is determined based on the height distances corresponding to the multiple image energy concentration values ​​and the multiple reference images, so that in the subsequent process, the target height distance can be directly determined from the reference curve graph. Moreover, the average value of the multiple regional energy concentration values ​​is used as the image energy concentration value corresponding to the reference image, which can improve the accuracy of the determined target height distance. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the structure of a detection system provided in an embodiment of the present application; Figure 2 A schematic diagram of the structure of a stage provided in an embodiment of the present application; Figure 3 A schematic diagram of the structure of another detection system provided in an embodiment of the present application; Figure 4 A schematic diagram of the positional relationship of various components in an illumination assembly provided in an embodiment of the present application and a light spot projected onto a stage; Figure 5 A schematic diagram of the positional relationship of various components in another lighting assembly provided in an embodiment of the present application and a light spot projected onto a stage; Figure 6 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; Figure 7 A flowchart of a lighting mode switching method provided in an embodiment of the present application; Figure 8 A schematic diagram of a reference image provided in an embodiment of the present application; Fig. 9 A schematic diagram of a region of interest provided in an embodiment of the present application; Fig.10 A schematic diagram of a reference curve graph provided in an embodiment of the present application; Fig.11 A flow chart of a detection method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below by specific embodiments in conjunction with the accompanying drawings. Wherein similar elements in different embodiments adopt associated similar element numbers. In the following embodiments, many detailed descriptions are for making the present application better understood. However, those skilled in the art can easily recognize that some features can be omitted in different situations, or can be replaced by other elements, materials, 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 part of the present application being overwhelmed by too much description, and for those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations according to the description in the specification and the general technical knowledge in the art.

[0026] In addition, the features, operations or characteristics described in the specification can be combined in any appropriate manner to form various implementations. At the same time, the steps or actions in the method description can also be interchanged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for the purpose of clearly describing a certain embodiment and are not meant to be a required sequence, unless otherwise specified that a certain sequence must be followed.

[0027] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings).

[0028] 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.

[0029] In the inspection process of semiconductors such as wafers, there are multiple work scenarios. Adapting 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 distance) is obtained by imaging and followed to improve the 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 repeated 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.

[0030] 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 comprises a stage 1, an illumination component 2, an imaging optical path component 3, a driving component 4 and a processor 5.

[0031] The stage 1 is used to carry the object to be tested and the reference object. Figure 2 , Figure 2 is a schematic diagram of the structure of a stage provided in an embodiment of the present application, from Figure 2 As can be seen in FIG. 1 , the stage 1 has a first carrying area 11 and a second carrying area 12 , wherein the first carrying area 11 is used for carrying the object to be measured, and the second carrying area 12 is used for carrying the reference object.

[0032] 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.

[0033] In some embodiments, the stage 1 can move along the 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.

[0034] 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).

[0035] 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 to move along the optical axis of the objective lens 33. For example, the optical axis of the objective lens 33 may be the Z axis direction (eg, vertical direction).

[0036] 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).

[0037] It should be noted that the object to be tested in the embodiments of the present application may be a semiconductor product such as a wafer or a chip. Since there may be defects such as flaws on its surface, it is necessary to perform optical inspection on its surface in order to control the quality of the product.

[0038] 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 tested or at least a portion of the area of ​​the reference object carried on the stage 1. Figure 1 It can be seen in the figure that the light beam emitted by the lighting assembly 2 can be projected onto the stage, thereby illuminating at least a partial area of ​​the object to be measured or at least a partial area of ​​the reference object.

[0039] The imaging optical path component 3 includes a filter 31, a detection sensor 32 and an objective lens 33; the imaging optical path component 3 is used to perform pupil filtering adaptation on the pupil and the filter 31, and send a third signal after the pupil filtering adaptation is completed, and the third signal is used to indicate that the pupil filtering adaptation of the object to be tested is completed. The imaging optical path component 3 is also used to perform optical imaging on the object to be tested and the reference object on the stage 1 through the objective lens 33, and transmit the optical signal obtained by imaging to the detection sensor 32, and the detection sensor 32 is used to convert the optical signal into an electrical signal, so as to obtain the image to be tested of the object to be tested and the reference image of the reference object.

[0040] Among them, the filter 31 is located on the pupil plane. The pupil refers to the image of the aperture in the optical path that limits or controls the passage of the light beam (such as the camera aperture, the edge of the microscope objective lens). The pupil can limit the angle and range of the incident light to avoid interference from stray light. Pupil filter adaptation optimizes the collection efficiency of the defect scattered light corresponding to the object to be tested and suppresses background noise by adjusting the parameters or configuration of the filter 31 at the pupil. In other words, pupil filter adaptation selects light signals (such as specific scattering angles or wavelengths) that match the defect scattering characteristics of the object to be tested through the shape, transmittance, and polarization characteristics of the filter 31. It can also block stray light in non-defective areas of the object to be tested (such as scattering caused by the roughness of the substrate of the object to be tested) and reduce background noise. Therefore, pupil filter adaptation can improve the detection sensitivity and accuracy of the detection system.

[0041] Continuing with the above description, after pupil filtering adaptation is completed, the imaging optical path component 3 may further send a third signal, so that the processor 5 can perform corresponding operations in a subsequent process.

[0042] In some embodiments, the detection sensor 32 may be a TDI (Time Delayed and Integration) camera.

[0043] 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 tested or the reference object onto the detection sensor 32. That is to say, after the objective lens 33 collects light from the surface of the object to be tested or the reference object, the tube lens system 34 can focus the light onto the detection sensor 32 for imaging.

[0044] 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.

[0045] The driving assembly 4 is used to drive the stage 1 and the objective lens 33 to move relative to each other, and to drive the lighting assembly 2 to switch the lighting mode. The driving assembly 4 may drive the stage 1 to move while the objective lens 33 remains stationary, or the driving assembly 4 may drive the objective lens 33 to move while the stage 1 remains stationary, or the driving assembly 4 may drive the stage 1 to move and drive the objective lens 33 to move.

[0046] 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. The driving component 4 may also drive the stage 1 to move and drive the objective lens 33 to move to achieve relative movement of the two along the scanning direction.

[0047] As another example, the drive component 4 drives the objective lens 33 to move relative to each other along the optical axis of the objective lens 33. The drive component 4 may drive the objective lens 33 to move along the optical axis while the objective lens 33 remains stationary. The drive component 4 may drive the objective lens 33 to move along the optical axis while the stage 1 remains stationary. The drive component 4 may also drive the stage 1 to move and drive the objective lens 33 to move so as to achieve relative movement of the two along the optical axis.

[0048] 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. 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. The driving component 4 may also drive the stage 1 to move and drive 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).

[0049] In addition, in some embodiments, the lighting assembly 2 includes multiple components, and when the multiple components are in different positions, the lighting assembly 2 has different corresponding lighting modes. Therefore, in order for the lighting assembly 2 to switch the lighting mode, the driving assembly also needs to drive the multiple components in the lighting assembly 2 to change the positions of the multiple components, thereby enabling the lighting assembly to switch the lighting mode.

[0050] In some embodiments, the driving component 4 can be implemented based on driving components such as piezoelectric, servo motor, DD motor, etc.

[0051] The processor 5 includes but is not limited to a central processing unit (CPU), a microcontroller unit (MCU), a field-programmable gate array (FPGA), a digital signal processing (DSP), and other devices for interpreting computer instructions and processing data in computer software.

[0052] In some embodiments, the processor 5 can execute each computer application in the non-transitory computer-readable storage medium, thereby executing the corresponding steps and methods. For example, the processor 5 can be implemented by software, hardware, firmware or a combination thereof, and can use a circuit, a single or multiple application-specific integrated circuits (Application Specific Integrated Circuit, ASIC), a digital signal processor (Digital Signal Processor, DSP), a digital signal processing device (Digital Signal Processing Device, DSPD), a programmable logic device (Programmable Logic Device, PLD), a field programmable gate array (Field Programmable Gate Array, FPGA), a central processing unit (Central Processing Unit, CPU), a controller, a microcontroller, a microprocessor, at least one of the above, so that the processor 5 can execute some steps or all steps of the lighting mode switching method in various embodiments of the present application or any combination of the steps therein, or so that the processor 5 can execute some steps or all steps of the detection method in various embodiments of the present application or any combination of the steps therein.

[0053] In some embodiments, please refer to Figure 3 The lighting assembly 2 includes: a light source module 21, which is used to emit a lighting beam; a beam expansion module 22, which is used to adjust the lighting beam; a first light spot shaping module 23, which is used to adjust the light spot corresponding to the lighting beam passing through the beam expansion module 22 to obtain a line lighting spot or a surface lighting spot; a second light spot shaping module 24, which is used to shape the light spot into a local lighting spot.

[0054] 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.

[0055] 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 compression can be achieved, 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.

[0056] 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.

[0057] 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.

[0058] In some embodiments, the second light spot shaping module 24 includes a line light spot modulation device. When the line light spot modulation device cuts in, that is, when the light spot can pass through the line light spot modulation device, the line light spot modulation device can shape the light spot into a local illumination light spot.

[0059] In some embodiments, please refer to Figure 4 , Figure 4 It is a schematic diagram of the positional relationship of each component in an illumination assembly and the light spot projected onto the stage provided in an embodiment of the present application. 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 expansion module 22 by adjusting the beam expansion module 22 to obtain a first emergent light beam; adjusting the light spot corresponding to the first emergent 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.

[0060] Based on the above description, it can be known that the beam expander group 221 can achieve the expansion of 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 light spot. Therefore, the processor 5 can obtain the required first outgoing light beam by appropriately adjusting the beam expander module, and then the first light spot shaping module 23 can obtain the surface illumination light spot according to the emission angle and magnification corresponding to the first outgoing light beam.

[0061] 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.

[0062] In some embodiments, please refer to Figure 5 , Figure 5 It is a schematic diagram of the positional relationship of each component 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 expansion module 22 by adjusting the beam expansion 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.

[0063] Based on the above description, it can be known that the beam expander group 221 can achieve the expansion of 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.

[0064] 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.

[0065] In some embodiments, please refer to Figure 6 , Figure 6 It is a schematic diagram of the positional relationship of each component in another lighting assembly provided in an embodiment of the present application and the light spot projected onto the stage. The processor 5 controls the lighting assembly 2 to switch the lighting mode to the third lighting mode, including: controlling the light source module 21 to emit an illumination light beam; shaping the light spot corresponding to the illumination light beam into a line illumination light spot by adjusting the beam expansion module 22 and the first light spot shaping module 23; 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 light spot.

[0066] Based on the above description, it can be known that the beam expander group 221 can achieve the expansion of 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 line illumination spot. Therefore, the processor 5 obtains the line illumination spot by appropriately adjusting the beam expander module and the first light spot shaping module 23.

[0067] 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 the second light spot shaping module 24 interfering with the linear illumination spot.

[0068] 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.

[0069] In some embodiments, before using the detection system to detect the object to be detected, the technician can simulate and analyze the illumination beam of the light source module 21 and the final light spot morphology, so as to adjust the beam expansion module 22 and customize the appropriate first light spot shaping module 23 to shape the illumination beam with a fixed beam waist radius, so as to form a linear illumination spot on the object surface (such as the detection area of ​​the object to be detected in the stage 1, or at least a part of the reference object in the stage 1). In this way, the default illumination mode when the detection system is started can be the third illumination mode.

[0070] 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.

[0071] 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 the surface illumination spot, that is, switch the illumination mode of the illumination component 2 from the third illumination mode to the first illumination mode.

[0072] 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.

[0073] 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 switch 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.

[0074] That is to say, when setting up the detection system, the technician needs to adjust the beam expansion module 22 according to the shaping effect of the first light spot shaping module 23 to achieve the best narrow line illumination on the object plane, that is, to make the light spot on the object plane a line illumination light 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 relationship of the beam expansion lens group 221 in the beam expansion module 22, the divergence angle and magnification of the illumination light beam are changed to achieve surface illumination on the object plane, that is, to make the light spot on the object plane a surface illumination light spot, thereby switching the illumination mode to the first illumination mode. At the same time, on the basis of the third illumination mode, cutting into the second shaping module and adjusting the alignment can make the line illumination light spot converge along the long side direction, and realize precise illumination of the local area on the object plane, that is, to make the light spot on the object plane a local illumination light spot, thereby switching the illumination mode to the second illumination mode.

[0075] In some embodiments, the lighting assembly 2 includes a spatial light modulator, so that the processor 5 can switch the lighting mode of the lighting assembly 2 through the spatial light modulator. A spatial light modulator is a device that can dynamically control the spatial distribution characteristics of light waves (such as amplitude, phase, polarization state or wavelength) in real time. It adjusts the properties of light point by point or region by region on a two-dimensional plane through electrical signals, optical signals or other external excitations, thereby achieving complex light field control. The spatial light modulator can achieve continuous changes in the illumination spot within a certain range.

[0076] In addition, in some embodiments, the lighting assembly 2 includes a digital micromirror device, so that the processor 5 can switch the lighting mode of the lighting assembly 2 through the digital micromirror device. The digital micromirror device is an optical modulation device based on micro-electromechanical system technology, which realizes binary spatial modulation ("on" or "off") of the light field by controlling the mechanical deflection state of millions of micro-mirrors. The digital micromirror device can realize continuous changes in the illumination spot within a certain spatial resolution.

[0077] Next, a lighting mode switching method provided in an embodiment of the present application is explained in detail.

[0078] Figure 7 is a flowchart of a lighting mode switching method provided in 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: Step 701: In response to a first signal, control the illumination mode to switch to a first illumination mode to uniformly illuminate a reference object carried on a stage, wherein the first signal is used to indicate that a detection system needs to perform focusing.

[0079] In some embodiments, the technician can send a first signal through a click operation of the host computer to indicate the start of the detection process, thereby being able to control the lighting mode to switch to the first lighting mode in response to the first signal.

[0080] Before testing the object to be tested, focus search is performed first. During the focus search, uniform illumination light is used within the entire field of view to avoid large grayscale deviation of the dot matrix image due to uneven illumination light, so as to accurately obtain image quality information of the dot matrix within the entire field of view, thereby obtaining a reference image of an accurately determined reference object in the subsequent process, thereby improving the focus accuracy, that is, improving the accuracy of the target height distance determined in the subsequent process. Therefore, the illumination spot of the first illumination mode can be a surface illumination spot.

[0081] It should be noted that the above description is based on the light spot of the first illumination mode as the surface illumination light spot, or, in application, the first illumination mode may also correspond to other light spots. This embodiment of the application does not limit this.

[0082] 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, and 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, and 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.

[0083] Since the graphic types corresponding to various areas of the object to be tested may be different when inspecting 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 perform a subsequent focus-finding process.

[0084] In some embodiments, for each reference image among 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, an 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.

[0085] That is to say, after acquiring 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, so as 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.

[0086] As an example, see Figure 8 , Figure 8 is a schematic diagram of a reference image provided in an embodiment of the present application. Figure 8 It can be seen that the reference image includes multiple regions, and a total of 9 regions in the dotted box are selected as the focus areas from the multiple regions. Afterwards, it is necessary to determine the regional energy concentration values ​​corresponding to these 9 regions, 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.

[0087] It should be noted that the above description is based on the selection of 9 focus regions, or, in application, any more or fewer regions in the reference image may be selected as focus regions according to circumstances. The present application embodiment does not limit this.

[0088] In some embodiments, the regional energy concentration value corresponding to each of the multiple regions of interest may be determined according to the following steps (1)-(3); (1) Determine the central pixel in the focus area, which is the pixel with the largest grayscale value in the focus area.

[0089] That is to say, the pixel with the largest gray value in the focus area can be determined as the central pixel. For example, please refer to Fig. 9 , Fig. 9 is a schematic diagram of a region of interest provided in an embodiment of the present application, wherein the central pixel is Fig. 9 The gray area A0 in the figure.

[0090] (2) With the central pixel as the center, determine the first sub-region, the second sub-region and the third sub-region in the target area. 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 other regions in the target area that are located outside the second sub-region.

[0091] As an example, see Fig. 9 , the first sub-region is Fig. 9 The white area A1 in the second sub-area is Fig. 9 The shaded area A2 in the figure is the third sub-area. Fig. 9 The black area A3 in the figure.

[0092] It should be noted that Fig. 9 The area sizes of the first sub-area, the second sub-area and the third sub-area are only examples, and in actual application, the area sizes of the first sub-area, the second sub-area and the third sub-area can be changed according to the situation. The embodiment of the present application does not limit this.

[0093] (3) Based on the first sub-region, the second sub-region, and the third sub-region, determine corresponding regional energy concentration values.

[0094] In some embodiments, the corresponding regional energy concentration values ​​may be determined based on the first sub-region, the second sub-region, and the third sub-region according to the following steps ae; a. Based on the pixels in the second sub-area and the pixels in the third sub-area, determine the average noise.

[0095] Since the second sub-region and the second sub-region both include a plurality of pixels, it is necessary to calculate the noise value of each of the plurality of pixels. For example, the noise value of each pixel is the difference between the pixel in the noisy image and the pixel in the focus area, wherein the noisy image refers to an image in which pixel values ​​have unexpected random changes due to various interferences, and such images usually contain abnormal brightness or color fluctuations that are not derived from the original scene.

[0096] It should be noted that the above description is based on the determination of the noise of each pixel according to the difference between the noisy image and the region of interest. Alternatively, in an application, the noise of each pixel may also be determined by other methods.

[0097] It should be noted that after obtaining the noises corresponding to the multiple pixels in the second sub-region and the third sub-region, the multiple noises may be averaged, and the obtained average value may be determined as the average noise. Alternatively, the standard deviation or median of the multiple noises may be calculated to determine the average noise. This embodiment of the present application does not limit this.

[0098] b. Determine a plurality of grayscale pixels in the first sub-region, wherein the plurality of grayscale pixels include a first pixel in the first sub-region with a maximum grayscale value and at least one pixel whose grayscale value is successively smaller than the grayscale value of the first pixel.

[0099] That is to say, it is necessary to determine a plurality of pixels with the largest grayscale value in the first sub-region, that is, the plurality of 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 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 successively; if it is necessary to select 4 grayscale pixels, then pixels P1, P2, P3 and P4 can be determined as grayscale pixels.

[0100] c. Determine a first energy value based on multiple grayscale pixels and average noise.

[0101] In some embodiments, average noise may be subtracted from each of a plurality of grayscale pixels to obtain a plurality of grayscale pixels after average noise subtraction, and then the grayscale values ​​of the plurality of grayscale pixels after average noise subtraction may be added to obtain a first energy value.

[0102] After determining the plurality of grayscale pixels and the average noise, it is necessary to deduct the average noise from each of the plurality of grayscale pixels to reduce the interference of the noise, thereby improving the accuracy of the determined regional energy concentration value. Then, for the plurality of grayscale pixels after deducting the average noise, the grayscale value of each grayscale pixel is determined to obtain the grayscale values ​​corresponding to the plurality of grayscale pixels after deducting the average noise, and then the plurality of grayscale values ​​are added to determine the first energy value.

[0103] d. Determine a second energy value based on the pixels in the second sub-region and the average noise.

[0104] 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 grayscale values ​​of the plurality of pixels after average noise deduction are added to obtain the second energy value.

[0105] After the noise is determined, the average noise can be deducted from each pixel in the second sub-region to reduce the interference of the noise and improve the accuracy of the regional energy concentration value determined subsequently. Then, for all pixels in the second sub-region after the average noise is deducted, the gray value of each pixel is determined to obtain the gray value of each pixel in the second sub-region, and then the multiple gray values ​​are added to determine the second energy value.

[0106] e. Determine a regional energy concentration value based on the first energy value and the second energy value.

[0107] In some embodiments, after the first energy value and the second energy value are obtained, the ratio of the first energy value to the second energy value may be determined as the regional energy concentration value.

[0108] 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 in other ways. This embodiment of the application does not limit this.

[0109] For each region of interest, after determining the regional energy concentration value corresponding to each region of interest according to the above steps ae to obtain 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.

[0110] 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, therefore, 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.

[0111] 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.

[0112] Based on the above description, it is known that the image energy concentration value corresponding to each reference image can be determined, thereby obtaining multiple image energy concentration values. Moreover, since the multiple reference images are obtained by photographing the reference object on the stage at different height distances, it can be known that each of the multiple reference images has a corresponding height distance and image energy concentration value. Therefore, the reference curve graph can be determined according to the image energy concentration values ​​and height distances corresponding to the multiple reference images.

[0113] After the reference curve graph is obtained, 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.

[0114] As an example, see Fig.10 , Fig.10is a schematic diagram of a reference curve graph provided in an embodiment of the present application, wherein the horizontal axis of the reference curve graph is the height distance, and the vertical axis is the image energy concentration value. Fig.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 when the height distance is X, the corresponding imaging quality is the highest. Therefore, the height distance X can be determined as the target height distance.

[0115] 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, and 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.

[0116] That is to say, the upper surface of the object to be measured and the upper surface of the reference object may not be in the same horizontal plane because the bottom surfaces of the first bearing area and the second bearing area of ​​the stage are not in the same horizontal plane, or because the thickness of the object to be measured is different from the thickness of the reference object. 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.

[0117] 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 filter adaptation on the object to be measured on the stage, the second signal is used to indicate that the focus is completed, and the target area is a partial area of ​​the object to be measured.

[0118] In some embodiments, after the focus search is completed, a second signal is triggered, thereby, in response to the second signal, the lighting mode can be controlled to switch to the second lighting mode.

[0119] When pupil filter adaptation is performed, the illumination spot of the second illumination mode can be a local illumination spot, which gives priority to the specific area of ​​interest, realizes precise illumination of the local area, avoids interference of diffraction orders of non-areas of interest, and gives priority to pupil filter adaptation of the specific area of ​​interest. Therefore, the detection sensitivity of the specific area of ​​interest can be improved.

[0120] It should be noted that the above description is based on the light spot of the second illumination mode as a local illumination light spot, or, in application, the second illumination mode may also correspond to other light spots. This embodiment of the application does not limit this.

[0121] Step 703: receiving a third signal, and controlling the illumination mode to switch to the 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.

[0122] After the pupil filter adaptation is completed, a third signal may be received, indicating that the pupil filter adaptation of the object to be measured has been completed and the object to be measured can be scanned and imaged. Therefore, after receiving the third signal, the illumination mode needs to be controlled to switch to the third illumination mode.

[0123] Since it is necessary to match the line scanning image acquisition mode when scanning and testing the object to be tested to achieve efficient scanning imaging of the object to be tested, the illumination spot of the third illumination mode may be a line illumination spot.

[0124] It should be noted that the above description is based on the light spot of the third illumination mode as a linear illumination light spot, or, in application, the third illumination mode may also correspond to other light spots. This embodiment of the application does not limit this.

[0125] 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 search for 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 completes the focus search and needs to perform pupil filter adaptation on the object to be tested, in response to the second signal, controls the lighting mode to switch to the second lighting mode 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-interest area, thereby improving the detection sensitivity of the specific interest area; when the detection system completes the pupil filter adaptation and needs to perform scanning imaging on the object to be tested, it can receive the third signal and control the lighting mode to switch to the third lighting mode to achieve line 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 for different working scenes, thereby meeting the lighting requirements in different working scenes, 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 according to a plurality of 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 finding accuracy.

[0126] Fig.11 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. Fig.11 , the method comprises the following steps: Step 1101: in the third illumination mode, controlling the imaging of the object to be tested to obtain an image of the object to be tested corresponding to the test area at the current scanning position.

[0127] In some embodiments, the object to be tested corresponds to different areas to be tested at different scanning positions. By imaging the different areas to be tested of the object to be tested at a plurality of different scanning positions, scanning and imaging of the surface of the object to be tested can be completed.

[0128] Step 1102: Detect the area to be detected based on the image to be detected.

[0129] For example, defect detection may be performed on the area to be tested based on the image to be tested.

[0130] It can be understood that step 1102 can detect the corresponding area to be tested based on the image to be tested based on an existing or future detection algorithm.

[0131] The embodiment of the present application can improve detection efficiency by detecting the object to be detected under the third lighting mode.

[0132] 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, various operating steps and components for performing the operating steps may be implemented in different ways (e.g., one or more steps may be deleted, modified, or combined into other steps) depending on the specific application or considering any number of cost functions associated with the operation of the system.

[0133] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. In addition, as understood by those skilled in the art, the principles of this article can be reflected in a computer program product on a computer-readable storage medium, which is pre-installed with a computer-readable program code. Any tangible, non-temporary computer-readable storage medium can be used, including magnetic storage devices (hard disks, floppy disks, etc.), optical storage devices (CD to ROM, DVD, Blue Ray disks, etc.), flash memory and / or the like. These computer program instructions can be loaded onto a general-purpose computer, a special-purpose computer, or other programmable data processing device to form a machine, so that these instructions executed on a computer or other programmable data processing device can generate a device that implements a specified function. These computer program instructions can also be stored in a computer-readable memory, which can instruct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory can form a manufactured product, including an implementation device that implements a specified function. Computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operating steps are performed on a computer or other programmable device to generate a computer-implemented process, so that the instructions executed on a computer or other programmable device can provide steps for implementing a specified function.

[0134] Although the principles of this invention have been shown in various embodiments, many modifications of structures, arrangements, proportions, elements, materials and components 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 will be included in the scope of this invention.

[0135] The foregoing specific 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 the present disclosure. Therefore, the consideration of the present disclosure will be illustrative rather than restrictive, and all these modifications will be included in its scope. Similarly, the advantages, other advantages and solutions to the problems of 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 clear, should not be interpreted as critical, necessary or necessary. The term "include" and any other variants used in this article are all non-exclusive inclusions, so that the process, method, article or device including the list of elements not only includes these elements, but also includes 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.

[0136] Those skilled in the art will appreciate that many changes may be made to the details of the above-described 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 the reference object carried on the stage, wherein the first signal is used to indicate that the detection system needs to perform focus search; 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; A third signal is received, and the illumination mode is controlled to switch to the third illumination mode to scan and image 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.

2. The lighting mode switching method according to claim 1, characterized in that: 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 a plurality of 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; Based on the multiple reference images, a target height distance is determined, 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, characterized in that: Determining the target height distance based on the multiple reference images includes: For each reference image in the plurality of reference images: determining a plurality of focus regions in the reference image; determining regional energy concentration values ​​corresponding to the plurality of focus regions 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, characterized in that: The determining, based on the plurality of regional energy concentration values, an image energy concentration value corresponding to the reference image comprises: 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, characterized in that: 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 comprises: 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 any one of claims 1 to 5, characterized in that: After determining the target height distance based on the multiple reference images, the method further includes: Control the stage to move to a 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, and 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. The lighting mode switching method according to claim 1, characterized in that: The illumination spot of the first illumination mode is a surface illumination spot.

8. The lighting mode switching method according to claim 1, characterized in that: The illumination spot of the second illumination mode is a local illumination spot.

9. The lighting mode switching method according to claim 1, characterized in that: The illumination spot of the third illumination mode is a line illumination spot.

10. A detection method, characterized in that: The method comprises: According to the method of any one of claims 1 to 9, in the third illumination mode, controlling 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; The area to be tested is detected based on the image to be tested.

11. 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 component, used for switching illumination modes and illuminating at least a partial area of ​​the object to be measured or at least a partial area of ​​the reference object carried on the stage through an illumination beam; An imaging optical path component, comprising 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 send a third signal after the pupil filtering adaptation is completed, 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 perform optical imaging on 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, the detection sensor is used to convert the optical signal into an electrical signal, so as to obtain a test image of the object to be measured and a reference image of the reference object; A driving assembly, used for driving the stage and the objective lens to move relative to each other, and driving the lighting assembly to switch the lighting mode; A processor, configured to execute the method according to any one of claims 1 to 10.

12. The detection system according to claim 11, characterized in that: The lighting assembly comprises: A light source module, used for emitting 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 light spot or a surface illumination light spot; The second light spot shaping module is used to shape the light spot into a local illumination light spot.

13. The detection system according to claim 12, characterized in that: The processor controlling the lighting component to switch the lighting mode to the first lighting mode comprises: Controlling the light source module to emit an illumination light 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; The light spot corresponding to the first outgoing light beam is adjusted to 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.

14. The detection system according to claim 12, characterized in that: The processor controlling the lighting component to switch the lighting mode to the second lighting mode comprises: Controlling the light source module to emit an illumination light 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; The light spot corresponding to the second outgoing light beam is adjusted to 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.

15. The detection system according to claim 12, characterized in that: The processor controlling the lighting component to switch the lighting mode to the third lighting mode comprises: Controlling the light source module to emit an illumination light 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.

16. The detection system according to claim 11, characterized in that: The illumination assembly includes a spatial light modulator.

17. The detection system according to claim 11, characterized in that: The illumination assembly includes a digital micromirror device.

18. 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 10.

Images