Optical detection equipment and control method thereof

Abstract

The invention relates to the technical field of optical detection, in particular to optical detection equipment and a control method thereof.The optical detection equipment comprises a reinspection light source, a bright field light source and a dark field light source, and bright field signal light, dark field signal light and reinspection signal light are transmitted along a common light path; the collection reflection element is used for collecting the bright field signal light and the dark field signal light and carrying out spatial separation, so that the bright field signal light is reflected to enter the first transmission path for bright field imaging, and the dark field signal light enters the second transmission path for dark field imaging; the reflector element is arranged on the transmission path of the reinspection signal light and is used for reflecting the reinspection signal light to a third transmission path for reinspection imaging; the reinspection light is a stroboscopic light beam to weaken smear generated by the reinspection signal light during reinspection imaging, the reinspection signal light is totally reflected by the reflector element to reduce light intensity attenuation, and the reinspection system and the reinspection method are at least beneficial to improving the detection precision of reinspection.

Description

Technical Field

[0001] The present invention relates to the field of optical detection technology, and in particular to an optical detection device and a control method thereof. Background Art

[0002] In the process of semiconductor chip processing, the inevitable contamination and defects caused by manufacturing errors are the main reasons for the failure of semiconductor chips. Therefore, during the manufacturing of semiconductor chips, defect detection of wafers used to prepare semiconductor chips can improve the yield rate and thus obtain higher profits. Among the existing defect detection equipment, the defect detection method based on optical imaging has the advantages of fast detection and non-contact, and is the most commonly used means of defect detection.

[0003] For defect detection equipment based on optical imaging, detection speed and detection accuracy are important indicators involved in detection. Among them, detection accuracy refers to the minimum size of defects that can be detected. It is understandable that increasing the magnification can obtain a smaller optical resolution and improve detection accuracy, but it also reduces the detection speed. In order to achieve fast and high-precision defect detection, defect detection usually includes two steps: initial inspection and re-inspection. Among them, the initial inspection is used to scan and detect the specified area with a low magnification to preliminarily obtain the defect location and preliminary morphological information of the defect in the area. During the re-inspection, the defect location is moved to the re-inspection probe, and re-inspection imaging is performed with a high magnification to obtain a higher-precision defect image and analyze more detailed information about the defect.

[0004] However, the re-inspection accuracy of current defect detection equipment needs to be improved. Summary of the invention

[0005] In view of this, the present invention aims to provide an optical detection device and a control method thereof, which are at least beneficial to improving the detection accuracy of re-inspection.

[0006] To achieve the above object, the technical solution created by the present invention is implemented as follows: The invention provides an optical detection device, comprising: a re-test light source, the re-test light source emits re-test light, the re-test light is incident on the surface of the sample to be tested, and is reflected by the sample to be tested to form a re-test signal light; a bright field light source that emits bright field light and a dark field light source that emits dark field light, the bright field light and the dark field light are respectively incident on the surface of the sample to be tested, the bright field light is reflected by the sample to be tested to form a bright field signal light, the dark field light is scattered by the sample to be tested to form a dark field signal light, the bright field signal light, the dark field signal light and the re-test signal light are transmitted along a common optical path; a collecting reflective element, a collecting The reflective element is used to collect bright field signal light and dark field signal light and perform spatial separation, so that the bright field signal light is reflected into the first transmission path for bright field imaging, and the dark field signal light is entered into the second transmission path for dark field imaging; the reflector element is arranged on the transmission path of the re-inspection signal light, and is used to reflect the re-inspection signal light to the third transmission path for re-inspection imaging; the re-inspection light is a stroboscopic light beam to weaken the smear generated by the re-inspection signal light during re-inspection imaging, and the re-inspection signal light is totally reflected by the reflector element to reduce the attenuation of light intensity.

[0007] In some embodiments, the dark field signal light and the bright field signal light do not overlap when transmitted in a common optical path, and the distance between the dark field light spot formed by the dark field light on the surface of the sample to be inspected and the bright field light spot formed by the bright field light on the surface of the sample to be inspected is in the range of 0.2 mm to 3 mm.

[0008] In some embodiments, the re-test signal light does not overlap with the bright field signal light and the dark field signal light when transmitted on a common optical path; the re-test light and the bright field light have a common transmission optical path, and the re-test light and the bright field light do not overlap when transmitted.

[0009] In some embodiments, in the common optical path, the recheck signal light is located between the dark field signal light and the bright field signal light, and the recheck signal light, the dark field signal light and the bright field signal light are kept non-overlapping by mutual spatial isolation.

[0010] In some embodiments, a portion of the beam path of the re-inspection light overlaps with a portion of the beam path of the bright field light, and a portion of the beam path of the bright field signal light overlaps with a portion of the beam path of the re-inspection signal light; the optical detection device also includes a first reflector group, and when performing a re-inspection, the first reflector group is used to be moved to the beam path of the bright field light, and the re-inspection light is guided to the surface of the sample to be inspected through the first reflector group by blocking the bright field light; and the reflector element is used to be moved to the beam path of the bright field signal light, and the re-inspection signal light is reflected to the third transmission path through the reflector element; when performing bright field detection, the first reflector group is also used to be moved out of the beam path of the bright field light, and the reflector element is also used to be moved out of the beam path of the bright field signal light.

[0011] In some embodiments, the collecting reflective element includes a first reflective surface and a second reflective surface. The bright field signal light incident to the collecting reflective element enters the first transmission path after being reflected by the first reflective surface, and the dark field signal light incident to the collecting reflective element enters the second transmission path after being reflected by the second reflective surface.

[0012] In some embodiments, the optical detection device also includes: a first detector, which is arranged on the first transmission path and is used to image the bright field signal light emitted by the collecting reflective element; a second detector, which is arranged on the second transmission path and is used to image the dark field signal light emitted by the collecting reflective element; and a third detector, which is arranged on the third transmission path and is used to image the re-inspection signal light emitted by the reflector element.

[0013] In some embodiments, the collecting reflection element is a trapezoidal prism, the first reflection surface and the second reflection surface are respectively arranged on two inclined sides of the trapezoidal prism, the first transmission path, the second transmission path and the third transmission path are all distributed in the same horizontal plane, and the first detector, the second detector and the third detector are arranged on the same horizontal platform surface to reduce the impact of the vibration of the horizontal platform surface on imaging.

[0014] In some embodiments, the bright field light source and the dark field light source include continuous light sources, the re-detection light source includes a stroboscopic light source, the first detector and the second detector include line scan cameras, and the third detector includes a color area array camera.

[0015] In some embodiments, the optical detection equipment also includes: an objective lens and a spectroscopic element arranged in sequence along a direction away from the sample to be inspected, the re-inspection light and the bright field light are sequentially incident on the surface of the sample to be inspected through the spectroscopic element and the objective lens, the bright field signal light and the dark field signal light are sequentially incident on the collecting reflection element through the objective lens and the spectroscopic element, and the re-inspection signal light is sequentially incident on the reflector element through the objective lens and the spectroscopic element.

[0016] In some embodiments, the optical detection device also includes an imaging lens group, which is arranged between the spectroscopic element and the collecting and reflecting element, and also between the spectroscopic element and the reflector element. The bright field signal light and the dark field signal light emitted from the spectroscopic element are both collected by the collecting and reflecting element through the imaging lens group, and the re-inspection signal light emitted from the spectroscopic element is incident on the reflector element through the imaging lens group.

[0017] In some embodiments, the target surface size of the first detector is the same as the target surface size of the second detector, and the imaging field of view of the imaging lens assembly satisfies the following formula: ; in, D is the diameter of the imaging field of view, l is the target length, w is the target width, dis the distance between the bright field and the dark field.

[0018] In some embodiments, the optical detection device also includes a re-inspection illumination modulator mirror group, a first reflector group and an illumination mirror group arranged between the re-inspection light source and the spectroscopic element. The re-inspection light emitted by the re-inspection light source passes through the re-inspection illumination modulator mirror group, the first reflector group and the illumination mirror group in sequence and is incident on the spectroscopic element.

[0019] In some embodiments, the objective lens includes multiple sub-objective lenses, each sub-objective lens has a different magnification, and one of the multiple sub-objective lenses is located in the light beam transmission path between the spectroscopic element and the sample to be tested, and the sub-objective lens located in the light beam transmission path is switchable.

[0020] In some embodiments, the optical detection equipment also includes an automatic focusing module, which includes an automatic focusing light source and a dichroic mirror. The dichroic mirror is arranged between the spectroscopic element and the objective lens. The automatic focusing light source is used to emit focused light, and the focused light is guided by the dichroic mirror to irradiate the surface of the sample to be inspected. The wavelength of the focused light is different from the wavelength of the re-inspection light, the wavelength of the bright field light, the wavelength of the dark field signal light, the wavelength of the bright field signal light, and the wavelength of the re-inspection signal light.

[0021] On the other hand, the present invention provides a control method for an optical detection device, comprising: providing an optical detection device, the optical detection device comprising a bright field light source, a dark field light source, a re-inspection light source, an objective lens, a collecting reflective element and a reflector element; the control method for the optical detection device comprises: performing an initial inspection on a sample to be inspected, switching the magnification of the objective lens to a first magnification, controlling the bright field light source to emit bright field light, and controlling the dark field light source to emit dark field light, irradiating the sample to be inspected with the bright field light so that the sample to be inspected emits a bright field signal light, irradiating the sample to be inspected with the dark field light so that the sample to be inspected scatters a dark field signal light, the dark field signal light and the bright field signal light do not overlap each other, and the dark field signal light and the bright field signal light are transmitted along a common optical path through the objective lens to be collected by the reflective element Collect, the collecting reflective element spatially separates the bright field signal light and the dark field signal light, so that the bright field signal light is reflected into the first transmission path for bright field imaging, and the dark field signal light is entered into the second transmission path for dark field imaging; re-inspect the sample to be inspected, switch the magnification of the objective lens to the second magnification, the second magnification is greater than the first magnification, control the re-inspection light source to emit re-inspection light, the re-inspection light is incident on the surface of the sample to be inspected, and is reflected by the sample to be inspected to form re-inspection signal light, the re-inspection signal light passes through the objective lens and is reflected by the reflector element to the third transmission path for re-inspection imaging, the re-inspection light is a stroboscopic light beam to weaken the smear generated by the re-inspection signal light during re-inspection imaging, and the re-inspection signal light is totally reflected by the reflector element to reduce light intensity attenuation.

[0022] In some embodiments, the initial inspection also includes: stepping and moving the sample to be inspected along a first direction for bright field imaging and dark field imaging, and stepping and moving the sample to be inspected along a second direction for bright field imaging and dark field imaging, the first direction being perpendicular to the second direction; the re-inspection also includes: when the initial inspection detects that the sample to be inspected has defects, re-inspection imaging is performed on the location of the defect.

[0023] In some embodiments, the optical detection device also includes a first reflector group, a partial beam path of the re-inspection light and a partial beam path of the bright field light overlap, and a partial beam path of the bright field signal light and a partial beam path of the re-inspection signal light overlap; the control method of the optical detection device also includes: when performing re-inspection, moving the first reflector group to the beam path of the bright field light, so that the re-inspection light is guided to the surface of the sample to be inspected through the first reflector group, and at the same time moving the reflector element to the beam path of the bright field signal light, so that the re-inspection signal light is reflected to the third transmission path through the reflector element; when performing bright field detection, moving the first reflector group out of the beam path of the bright field light, so that the bright field light is transmitted to the surface of the sample to be inspected, and at the same time moving the reflector element out of the beam path of the bright field signal light, so that the bright field signal light is transmitted into the first transmission path for bright field imaging.

[0024] Compared with the prior art, the invention can achieve the following beneficial effects: In the optical detection equipment provided by the embodiment of the present invention, the bright field light source for initial inspection and the dark field light source for initial inspection are independent of each other, avoiding the problem of limited wavelength selection during the detection process; and the re-inspection light source and the bright field light source are independent of each other, and the re-inspection signal light is the echo signal light formed after the re-inspection light emitted by the re-inspection light source is reflected by the sample to be inspected, and is not obtained by splitting the bright field signal light. Therefore, the intensity of the re-inspection signal light is strong, and the intensity of the bright field signal light is also strong, which is beneficial to improving the detection accuracy; in addition, using a stroboscopic light beam as the re-inspection light beam is beneficial to alleviating the imaging ghosting phenomenon caused by re-inspecting the high-speed moving sample to be inspected, which is beneficial to further improving the detection accuracy of the re-inspection. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings constituting part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings: Figure 1 A schematic diagram of the structure of an optical detection device according to an embodiment of the present invention; Figure 2 Another structural schematic diagram of the optical detection device according to the embodiment of the present invention; Figure 3 A schematic diagram of another structure of the optical detection device according to an embodiment of the present invention; Figure 4A schematic diagram of the structure of a reflective collecting element according to an embodiment of the present invention; Figure 5 A schematic diagram of a single-frame image corresponding to a stroboscopic light source and a single-frame image corresponding to a constant light source; Figure 6 A schematic diagram of the imaging field layout of the imaging lens assembly of the optical detection device described in the embodiment of the present invention.

[0026] Explanation of the reference numerals: 120, re-inspection light source; 100, bright field light source; 110, dark field light source; 191, sample to be inspected; 180, collecting reflection element; 183, through hole; 181, first reflection surface; 182, second reflection surface; 200, first detector; 210, second detector; 220, third detector; 160, objective lens; 150, spectroscopic element; 170, imaging lens group; 121, re-inspection illumination modulator lens group; 130, illumination lens group; 101, bright field illumination modulator lens group; 122, first reflection mirror group; 140, second reflection mirror group; 161, sub-objective lens; 230, auto-focusing light source; 231, dichroic mirror; 111, dark field illumination modulator lens group; 190, supporting platform. DETAILED DESCRIPTION

[0027] After analysis, it was found that for defect detection, the detection time mainly depends on the initial inspection scanning detection time, the number of defects in the re-inspection, and the positioning speed of the defect position. Within a fixed detection time, how to improve the initial inspection defect identification ability has become the key to improving defect detection accuracy. Considering that there are many types of defects that may exist on the chip, bright field imaging and dark field imaging have different resolution capabilities for different types of defects. It is proposed to use bright field imaging and dark field imaging detection methods in the initial inspection. In this way, how to reasonably set the optical path of bright field imaging, dark field imaging, and re-inspection imaging has become the key to defect detection technology based on optical imaging.

[0028] Existing implementation schemes can be divided into three categories: the first scheme sets up two or three completely independent optical systems to perform bright field imaging, dark field imaging and re-inspection imaging respectively. In this way, different optical systems need to be switched to switch between bright field detection, dark field detection and re-inspection, which increases the difficulty of locating the defect position and therefore greatly increases the detection time; the second scheme adopts a common optical path design. The field of view corresponding to the bright field and the dark field is the same. Bright field imaging and dark field imaging use light sources of different wavelengths for illumination. Different wavelengths of light are separated at the signal collection end to achieve simultaneous imaging of bright field and dark field, and then re-inspection is achieved by splitting the signal light. Considering the sensitivity of different defect materials to the wavelength of detection light, The sensitivity is different, and the detection wavelength selection of bright field and dark field in this scheme is limited; the third type of scheme also adopts a common optical path design, and the bright field and dark field correspond to different areas of the field of view respectively, to achieve regional detection of bright field and dark field, and the re-inspection and bright field share the same light source, and the bright field collected signal light is split to achieve re-inspection imaging (such as the optical scheme disclosed in patent US20090059215A1). This scheme realizes simultaneous detection of bright field and dark field under the same optical path system, and can well realize fast and high-precision judgment of defect positions, but the re-inspection splitting reduces the intensity of the bright field signal and the re-inspection signal. At the same time, the rapid movement of the chip during the re-inspection can easily cause the re-inspection imaging to produce a smear phenomenon, which in turn affects the detection accuracy.

[0029] To solve the above problems, an embodiment of the present invention provides an optical detection device and a control method thereof, which is helpful to solve the problem of limited selection of light source wavelength in the detection process, and is helpful to alleviate the imaging ghosting phenomenon caused by re-inspecting high-speed moving samples to be inspected, thereby helping to improve the detection accuracy of re-inspection.

[0030] In order to make the purpose, technical solution and advantages of the invention more clear, the invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described here are only used to explain the invention and do not constitute a limitation of the invention.

[0031] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0032] In the description of the invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the invention, unless otherwise specified, the meaning of "multiple" is two or more.

[0033] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0034] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0035] refer to Figure 1 to Figure 2On the one hand, the present invention provides an optical detection device, including: a re-test light source 120, the re-test light source 120 emits re-test light, the re-test light is incident on the surface of the sample to be tested 191, and is reflected by the sample to be tested 191 to form a re-test signal light; a bright field light source 100 that emits bright field light and a dark field light source 110 that emits dark field light, the bright field light and the dark field light are respectively incident on the surface of the sample to be tested 191, the bright field light is reflected by the sample to be tested 191 to form a bright field signal light, the dark field light is scattered by the sample to be tested 191 to form a dark field signal light, and the bright field signal light, the dark field signal light and the re-test signal light are transmitted along a common optical path; collecting Reflection element 180, collecting reflection element 180 is used to collect bright field signal light and dark field signal light and perform spatial separation, so that the bright field signal light is reflected into the first transmission path for bright field imaging, and the dark field signal light is entered into the second transmission path for dark field imaging; reflector element 183, reflector element 183 is arranged on the transmission path of the re-inspection signal light, and is used to reflect the re-inspection signal light to the third transmission path for re-inspection imaging; the re-inspection light is a stroboscopic light beam to weaken the smear generated by the re-inspection signal light during re-inspection imaging, and the re-inspection signal light is totally reflected by the reflector element 183 to reduce the attenuation of light intensity.

[0036] Among them, the bright field light source 100, the dark field light source 110 and the re-inspection light source 120 are independent of each other, which solves the problem of limited wavelength selection in the detection process; the bright field signal light, the re-inspection signal light and the dark field signal light are independent of each other, avoiding the need to split the previous signal light to obtain the bright field signal light and the re-inspection signal light, which is beneficial to ensure that the bright field signal light and the re-inspection signal light with stronger intensity are obtained, thereby facilitating the improvement of detection accuracy; the re-inspection signal light is fully reflected by the reflector element 183, and the light intensity attenuation is reduced as much as possible, thereby performing re-inspection imaging, which is beneficial to reducing re-inspection. The optical loss of the inspection signal light during transmission and even the light intensity attenuation during total reflection can be ignored, which is beneficial to improving the detection accuracy of the re-inspection. The use of a stroboscopic beam as the re-inspection light is beneficial to alleviating the imaging smear phenomenon caused by the high-speed moving sample 191 during re-inspection. Specifically, in order to increase the speed during the re-inspection, the camera is usually taken during the movement, and the re-inspection detector usually uses an array camera. If the re-inspection light is a constant-bright beam, due to the limited frequency of the array camera, the displacement caused by the movement within the exposure time of a single-frame photo is likely to produce a large smear, such as Figure 5 When a stroboscopic beam is used as the illumination light for re-inspection, the frequency of the re-inspection light will be higher than the frequency of the area array camera, that is, the stroboscopic time of the re-inspection light source 120 is very short, so the smear is small, as shown in FIG. Figure 5 As shown in (b) in the figure, the smear problem can be alleviated.

[0037] It should be noted that the extension direction of the first transmission path, the extension direction of the second transmission path, and the extension direction of the third transmission path are all different. In some examples, the first transmission path and the second transmission path can extend in two opposite directions, and the extension direction of the third transmission path can be perpendicular to (or parallel to) the extension direction of the first transmission path or the second transmission path. The collection reflection element 180 and the reflector element 183 are used to achieve spatial separation of bright field signal light, dark field signal light, and recheck signal light, so that the corresponding signal light is received by the corresponding detector, which solves the problem of high difficulty in detector setting caused by the close distance between the bright field signal light, the dark field signal light, and the recheck signal light.

[0038] The optical inspection device provided by the embodiment of the present invention is used to perform defect inspection on a sample 191 to be inspected. In some examples, the sample 191 to be inspected may be a chip or wafer with or without a pattern.

[0039] In some embodiments, reference Figure 1 and Figure 2 , the dark field signal light and the bright field signal light do not overlap each other when transmitted in the common optical path, and the distance between the dark field light spot formed on the surface of the sample 191 to be tested by the dark field light and the bright field light spot formed on the surface of the sample 191 to be tested by the bright field light is in the range of 0.2mm to 3mm. That is, the distance between the bright field light spot and the dark field light spot is neither too far nor too close, which is conducive to avoiding the difficulty of locating the same detection position, thereby improving the detection efficiency, and ensuring that the bright field detection and the dark field detection do not interfere with each other, thereby improving the detection accuracy.

[0040] In some embodiments, reference Figure 1 , the re-inspection signal light does not overlap with the bright field signal light and the dark field signal light when transmitted on a common optical path; the re-inspection light and the bright field light have a common transmission optical path, and the re-inspection light and the bright field light do not overlap with each other when transmitted.

[0041] In some embodiments, reference Figure 1 In the common optical path, the re-inspection signal light is located between the dark field signal light and the bright field signal light, and the re-inspection signal light, the dark field signal light and the bright field signal light are kept from overlapping each other through mutual spatial isolation. In this way, the distance between the dark field light spot and the bright field light spot, which are the largest among the dark field light spot, the bright field light spot and the re-inspection light spot, will not be too far or too close. The advantage of not being too far is that during the switching process of bright field detection, dark field detection and re-inspection, the difficulty of locating the same detection position is avoided, which is conducive to the rapid switching of different detection methods and the improvement of detection efficiency; the advantage of not being too close is that it is conducive to ensuring that the bright field detection, the dark field detection and the re-inspection will not interfere with each other, which is conducive to the improvement of detection accuracy.

[0042] In some embodiments, the re-inspection light spot is located between the dark field light spot and the bright field light spot, and the distance from the dark field light spot to the re-inspection light spot is the same as or different from the distance from the bright field light spot to the re-inspection light spot.

[0043] In some embodiments, reference Figure 2 , part of the beam path of the re-inspection light overlaps with part of the beam path of the bright field light, and part of the beam path of the bright field signal light overlaps with part of the beam path of the re-inspection signal light; the optical detection device also includes a first reflector group 122. When performing a re-inspection, the first reflector group 122 is used to be moved to the beam path of the bright field light, and the re-inspection light is guided to the surface of the sample 191 to be inspected through the first reflector group 122 by blocking the bright field light; and the reflector element 183 is used to be moved to the beam path of the bright field signal light, so that the re-inspection signal light is reflected to the third transmission path through the reflector element 183; when performing bright field detection, the first reflector group 122 is also used to be moved out of the beam path of the bright field light, so that the bright field light can be guided to the surface of the sample 191 to be inspected to generate bright field signal light, and the reflector element 183 is also used to be moved out of the beam path of the bright field signal light, so that the bright field signal light can also be transmitted to the collecting reflection element 180, and then enter the first transmission path for bright field imaging. In this way, the re-inspection optical path and the bright field detection optical path can be switched by moving the first reflector group 122 and the reflector element 183, so that the corresponding detection optical path can be turned on when performing the corresponding detection. In addition, the bright field detection and re-inspection are imaged on the same area on the sample 191 to be inspected. In the process of switching between the bright field detection and re-inspection, the difficulty of locating the same detection position is avoided, which is conducive to realizing the rapid switching of different detection methods and improving the detection speed.

[0044] In some embodiments, reference Figure 4 The collecting and reflecting element 180 includes a first reflecting surface 181 and a second reflecting surface 182. The bright field signal light incident to the collecting and reflecting element 180 enters the first transmission path after being reflected by the first reflecting surface 181, and the dark field signal light incident to the collecting and reflecting element 180 enters the second transmission path after being reflected by the second reflecting surface 182.

[0045] In some embodiments, the optical detection device also includes: a first detector 200, which is arranged on the first transmission path and is used to image the bright field signal light emitted by the collecting reflective element 180; a second detector 210, which is arranged on the second transmission path and is used to image the dark field signal light emitted by the collecting reflective element 180; and a third detector 220, which is arranged on the third transmission path and is used to image the re-inspection signal light emitted by the reflector element 183.

[0046] In some embodiments, reference Figure 4The collecting reflection element 180 is a trapezoidal prism, the first reflection surface 181 and the second reflection surface 182 are respectively arranged on the two oblique sides of the trapezoidal prism, the first transmission path, the second transmission path and the third transmission path are all distributed in the same horizontal plane, and the first detector 200, the second detector 210 and the third detector 220 are arranged on the same horizontal platform surface to reduce the influence of the vibration of the horizontal platform surface on the imaging. The principle that the first detector 200, the second detector 210 and the third detector 220 are arranged on the same horizontal platform can reduce the influence of vibration is as follows: Usually, there will be a support and shock-absorbing structure under the platform used to set the first detector 200, the second detector 210 and the third detector 220. If the first detector 200, the second detector 210 and the third detector 220 are arranged on the platform and arranged horizontally on the platform, then the center of gravity of the first detector 200, the second detector 210 and the third detector 220 is lower than the platform and can be better fixed to the platform; if the first detector 200, the second detector 210 and the third detector 220 are arranged in the vertical direction, the overall center of gravity will be higher, and the detector located on the upper layer cannot be directly fixed to the platform, and a supporting structure is required. In this way, the detector on the upper layer is more susceptible to vibration. Based on this, the embodiment of the present invention arranges the first detector 200, the second detector 210 and the third detector 220 on the same horizontal platform, which is conducive to reducing the influence of platform vibration on imaging.

[0047] In some embodiments, the bright field light source 100 and the dark field light source 110 include continuous light sources for forming an efficient linear illumination spot (long strip light spot) on the surface of the sample 191 to be inspected; in some examples, a linear optical fiber coupled bright field light source 100 or dark field light source 110 can be used as an illumination input end.

[0048] In some embodiments, the first detector 200 and the second detector 210 include line scan cameras; in some examples, the first detector 200 and the second detector 210 are both integral delay line scan cameras, which can maintain high-resolution image capture capabilities even when the sample 191 to be inspected moves at high speed, and are suitable for application scenarios in which the sample 191 to be inspected moves continuously and quickly for high-precision inspection.

[0049] In some embodiments, the re-inspection light source 120 includes a stroboscopic light source. Using a stroboscopic light source as the re-inspection light source 120 is helpful in alleviating the imaging smear phenomenon generated when re-inspecting a high-speed moving sample 191 to be inspected.

[0050] In some embodiments, the third inspection detector 220 includes a color area array camera. In this way, the third inspection detector 220 can be used to collect high-precision images with higher resolution and faster sensitivity, and can capture more details and more accurate colors, which helps technicians identify defect features by observing color images.

[0051] In some embodiments, reference Figure 1 and Figure 2 The optical detection equipment also includes: an objective lens 160 and a spectroscopic element 150 arranged in sequence along a direction away from the sample to be inspected 191, the re-inspection light and the bright field light are incident on the surface of the sample to be inspected 191 through the spectroscopic element 150 and the objective lens 160 in sequence, the bright field signal light and the dark field signal light are incident on the collecting and reflecting element 180 through the objective lens 160 and the spectroscopic element 150 in sequence, and the re-inspection signal light is incident on the reflector element 183 through the objective lens 160 and the spectroscopic element 150 in sequence.

[0052] In some embodiments, the optical detection device also includes an imaging lens group 170, which is arranged between the spectroscopic element 150 and the collecting and reflecting element 180, and is also arranged between the spectroscopic element 150 and the reflector element 183. The bright field signal light and the dark field signal light emitted from the spectroscopic element 150 are collected by the collecting and reflecting element 180 through the imaging lens group 170, and the re-inspection signal light emitted from the spectroscopic element 150 is incident on the reflector element 183 through the imaging lens group 170.

[0053] In some embodiments, for Figure 1 In the optical inspection equipment, the bright field spot and the dark field spot can both be long linear spots, and the re-inspection spot is a circular spot. For details, refer to Figure 6 The outermost circle represents the maximum field of view of the optical system. The maximum field of view refers to the field of view of the detector receiving bright field signal light, the field of view of the detector receiving dark field signal light, and the field of view of the detector receiving re-inspection signal light, which are combined according to their relative positions. The field of view of the detector receiving bright field signal light and the field of view of the detector receiving dark field signal light can be symmetrically distributed about the center of the maximum field of view, and the center of the field of view of the detector receiving re-inspection signal light can coincide with the center of the maximum field of view.

[0054] Figure 6 The imaging field of view layout diagram shown is also equivalent to the illumination field of view schematic diagram. The bright field light spot and the dark field light spot can be distributed symmetrically about the center of the field of view, and the center of the re-inspection light spot can coincide with the center of the maximum field of view.

[0055] It should be noted that in order to ensure that the bright field detection and the dark field detection do not interfere with each other, it is necessary to ensure that the bright field spot and the dark field spot do not interfere with each other. Therefore, a spacing area needs to be maintained between the bright field spot and the dark field spot. The spacing area serves as an isolation area, and the width of the spacing area is d The smaller the better, the theoretical value is 0, but due to the influence of aberration and stray light of the illumination light, the bright field spot and the dark field spot will have a halo or diffuse spot. d If the optical path is 0, it will cost a lot to make the surfaces of the relevant optical components clean enough without defects and the illumination light path free of aberration. Therefore, considering the engineering difficulty and cost, and also in order to introduce the re-inspection spot, the width of the interval area is d Reasonable settings are required to ensure that bright field detection and dark field detection do not interfere with each other, and that re-inspection spots can be added without separating the bright field illumination area and the dark field illumination area too far, resulting in a large imaging field of view. The preferred width of the interval area in the embodiment of the present invention is d It is 0.2mm~3mm.

[0056] In some embodiments, the target surface size of the first detector 200 is the same as the target surface size of the second detector 210, and the imaging field of view of the imaging lens assembly 170 satisfies the following formula: ; Among them, reference Figure 6 , D is the diameter of the imaging field of view, l is the target surface length, that is, the target surface length of the second detector 210, or the target surface length of the first detector 200, w is the target surface width, that is, the target surface width of the first detector 200, or the target surface width of the second detector 210, d is the distance between the bright field and the dark field.

[0057] In some embodiments, the spectroscopic element 150 includes a spectroscope, and the angle between the spectroscopic surface of the spectroscope facing the objective lens 160 and the horizontal direction can be 45°. The imaging lens group 170, the first detector 200, the second detector 210 and the third detector 220 are arranged on the same horizontal platform to reduce the impact of platform vibration on imaging.

[0058] In some embodiments, the transmittance of the beam splitter element 150 may be in the range of 0-50%, and the reflectance of the beam splitter element 150 may be in the range of 50%-100%. The reason for this setting is that since the signal of bright field detection is sufficient (i.e., the light intensity of bright field light is large), and the signal of dark field detection is weak (the light intensity of dark field light and the light intensity of dark field signal light are both weak), the reflectance of the beam splitter element 150 is large and the transmittance is small, thereby balancing the light effect of bright field detection and the light effect of dark field detection.

[0059] In some embodiments, the optical detection device further includes a re-inspection illumination modulator mirror group 121, a first reflector group 122, and an illumination mirror group 130 disposed between the re-inspection light source 120 and the beam splitter 150. The re-inspection light emitted by the re-inspection light source 120 passes through the re-inspection illumination modulator mirror group 121, the first reflector group 122, and the illumination mirror group 130 in sequence and is incident on the beam splitter 150. In some examples, the re-inspection illumination modulator mirror group 121 may include some optical elements such as relay lenses, filters, polarizers, and apertures to shape and modulate the re-inspection light.

[0060] In some embodiments, the illumination lens group 130 is further disposed between the bright field light source 100 and the beam splitter 150, and the optical detection device further comprises a bright field illumination modulation lens group 101, and the bright field light emitted by the bright field light source 100 sequentially passes through the bright field illumination modulation lens group 101 and the illumination lens group 130 and is incident on the beam splitter 150. In some examples, the bright field illumination modulation lens group 101 may include some optical elements such as relay lenses, filters, polarizers, and apertures, which are used to shape and modulate the bright field light.

[0061] That is to say, in some embodiments of the present invention, the re-test and bright field test share the illumination lens group 130, the beam splitter element 150, the objective lens 160 and the imaging lens group 170, which is helpful to reduce the setting cost of the optical detection equipment.

[0062] In some embodiments, the optical detection device further includes a dark field illumination modulation mirror group 111 located between the dark field light source 110 and the sample to be inspected 191 , and the dark field light emitted by the dark field light source 110 passes through the dark field illumination modulation mirror group 111 and is incident on the surface of the sample to be inspected 191 .

[0063] It should be noted that the dark field illumination modulation mirror group 111, the bright field illumination modulation mirror group 101, the re-inspection illumination modulation mirror group 121, the imaging mirror group 170 and the illumination mirror group 130 involved in the embodiments of the present invention are all used to realize optical modulation of the light beam, and the optical modulation includes but is not limited to collimation, filtering and focusing.

[0064] In some embodiments, reference Figure 1, the re-test light and the bright field light have a common transmission optical path, and the re-test light and the bright field light do not overlap each other during transmission. The optical detection device also includes a first reflector group 122. The re-test light emitted from the re-test illumination modulation mirror group 121 realizes an optical path turn through the first reflector group 122 and then enters the illumination mirror group 130. By setting the first reflector group 122, the problem of position conflict between the bright field light source 100 and the re-test light source 120 caused by the bright field light and the re-test light sharing the illumination mirror group 130 can be solved. Of course, in some cases, the first reflector group 122 can be eliminated, and the re-test light can be directly transmitted to the illumination mirror group 130 using a light beam transmission device such as an optical fiber.

[0065] In some embodiments, the optical detection device further includes a second reflector group 140, which can be used to realize the optical path turning of the complex inspection light and the bright field light. Figure 1 and Figure 2 The second reflector group 140 is arranged on the transmission optical path of the re-test light emitted from the illumination mirror group 130 and the bright field light emitted from the illumination mirror group 130. The re-test light and the bright field light are reflected by the second reflector group 140 and then the optical path is turned, and then the light is incident on the spectroscopic element 150. By setting the second reflector group 140 that realizes the optical path turning, the positions of various components in the optical detection device can be reasonably arranged, which is conducive to reducing the overall volume of the optical detection device. Of course, in some cases, the second reflector group 140 can also be eliminated, so that the re-test light and the bright field light are directly incident on the spectroscopic element 150.

[0066] In some embodiments, the objective lens 160 includes a plurality of sub-objective lenses 161, each of which has a different magnification. One of the plurality of sub-objective lenses 161 is located in the light beam transmission path between the beam splitting element 150 and the sample to be inspected 191, and the sub-objective lens 161 located in the light beam transmission path is switchable. When performing bright field detection and dark field detection, a sub-objective lens 161 with a lower magnification can be switched to the light beam transmission path. When performing re-inspection, a sub-objective lens 161 with a higher magnification can be switched to the light beam transmission path for re-inspection imaging. The magnification of the selected objective lens 160 needs to be flexibly configured according to actual needs, and is not specifically limited here.

[0067] In some embodiments, reference Figure 3The optical detection device also includes an automatic focusing module, which includes an automatic focusing light source 230 and a dichroic mirror 231. The dichroic mirror 231 is arranged between the beam splitter 150 and the objective lens 160. The automatic focusing light source 230 is used to emit a focused light, which is guided by the dichroic mirror 231 to illuminate the surface of the sample to be tested 191. The focused light is reflected on the surface of the sample to be tested 191 to form a focused detection light, and the focused detection light reaches the automatic focusing module along the original optical path. The automatic focusing module may also include an imaging detector, which collects spectral information or shape information of the focused detection light. Based on this information, the position of the sample to be tested 191 relative to the front focal plane of the sub-objective lens 161 can be determined. In addition, the wavelength of the focused light is different from the wavelength of the re-test light, the wavelength of the bright field light, the wavelength of the dark field signal light, the wavelength of the bright field signal light, and the wavelength of the re-test signal light. In this way, the dichroic mirror 231 can be used to reflect the focused light and transmit the re-inspection light, bright field light, dark field signal light, bright field signal light and re-inspection signal light, which can not only ensure that the focused light is incident on the surface of the sample to be inspected 191 through the objective lens 161, but also avoid the influence of the automatic focusing module on the re-inspection, bright field detection and dark field detection. It can be understood that the position of the sample to be inspected 191 is measured in real time by the automatic focusing module, and the sample to be inspected 191 is adjusted to the front focal plane of the sub-objective lens 161 to be in a focused state, so that the sample to be inspected 191 can be initially inspected and re-inspected.

[0068] In some embodiments, the automatic focusing module can use a detection light beam in the red band as the focusing light. In some examples, a detection light beam with a wavelength in the range of 650nm~700nm is preferably used as the focusing light. The spectrum of the detection light (re-inspection light, bright field light, dark field signal light, bright field signal light and re-inspection signal light) is preferably in the band of 400nm~650nm. The dichroic mirror 231 can reflect the light beam in the band above 650nm and transmit the light with a wavelength below 650nm, so that the focusing light and the detection light of the automatic focusing module do not interfere with each other.

[0069] In some embodiments, the optical detection device further includes a carrier 190, and the carrier 190 has a carrier surface for carrying the sample 191 to be tested. In some examples, the carrier 190 is an electric translation stage, which can horizontally carry the sample 191 to be tested and move it in the XYZ directions.

[0070] On the other hand, the present invention provides a control method for an optical detection device, including: providing an optical detection device, the optical detection device including a bright field light source 100, a dark field light source 110, a re-test light source 120, an objective lens 160, a collecting reflection element 180 and a reflector element 183; the control method for the optical detection device includes: performing an initial inspection on a sample 191 to be inspected, switching the magnification of the objective lens 160 to a first magnification, controlling the bright field light source 100 to emit bright field light, and controlling the dark field light source 110 to emit dark field light, the bright field light irradiating the sample 191 to be inspected so that the sample 191 to be inspected emits bright field signal light, the dark field light irradiating the sample 191 to be inspected so that the sample 191 to be inspected scatters dark field signal light, the dark field signal light and the bright field signal light do not overlap each other, and the dark field signal light and the bright field signal light are transmitted along a common optical path through the objective lens 160. The input is collected by the collecting reflective element 180, and the collecting reflective element 180 spatially separates the bright field signal light and the dark field signal light, so that the bright field signal light is reflected into the first transmission path for bright field imaging, and the dark field signal light is entered into the second transmission path for dark field imaging; for re-inspection of the sample 191 to be inspected, the magnification of the objective lens 160 is switched to the second magnification, the second magnification is greater than the first magnification, and the re-inspection light source 120 is controlled to emit re-inspection light, the re-inspection light is incident on the surface of the sample 191 to be inspected, and is reflected by the sample 191 to form re-inspection signal light, the re-inspection signal light passes through the objective lens 160 and is reflected by the reflector element 183 to the third transmission path for re-inspection imaging, the re-inspection light is a stroboscopic light beam to weaken the smear produced by the re-inspection signal light during re-inspection imaging, and the re-inspection signal light is totally reflected by the reflector element 183 to reduce the light intensity attenuation.

[0071] In some embodiments, the initial inspection also includes: stepping and moving the sample 191 to be inspected along a first direction for bright field imaging and dark field imaging, and stepping and moving the sample 191 to be inspected along a second direction for bright field imaging and dark field imaging, the first direction being perpendicular to the second direction; the re-inspection also includes: when the initial inspection detects that the sample 191 to be inspected has defects, re-inspection imaging is performed on the location of the defect.

[0072] In some embodiments, the optical detection device also includes a first reflector group 122, and a partial beam path of the re-inspection light overlaps with a partial beam path of the bright field light, and a partial beam path of the bright field signal light overlaps with a partial beam path of the re-inspection signal light; the control method of the optical detection device also includes: when performing re-inspection, moving the first reflector group 122 to the beam path of the bright field light, so that the re-inspection light is guided to the surface of the sample to be inspected 191 through the first reflector group 122, and at the same time moving the reflector element 183 to the beam path of the bright field signal light, so that the re-inspection signal light is reflected to the third transmission path through the reflector element 183; when performing bright field detection, moving the first reflector group 122 out of the beam path of the bright field light, so that the bright field light is transmitted to the surface of the sample to be inspected 191, and at the same time moving the reflector element 183 out of the beam path of the bright field signal light, so that the bright field signal light is transmitted into the first transmission path for bright field imaging.

[0073] It should be noted that the detection process of the sample 191 to be tested in the present invention is divided into initial inspection and re-inspection, wherein the initial inspection includes bright field detection and dark field detection, and the detection is performed simultaneously without interfering with the imaging. The sub-objective lens 161 with a lower magnification can be switched to the optical path to cooperate with the bright field detection and the dark field detection. When the re-inspection is performed after the bright field detection and the dark field detection are completed, the sub-objective lens 161 with a higher magnification can be switched to the optical path to cooperate with the re-inspection. Of course, in some cases, the initial inspection and re-inspection can also be carried out at the same time, such as selecting a sub-objective lens 161 with a suitable magnification to switch to the optical path, and the bright field detection, the dark field detection and the re-inspection are carried out simultaneously. Since the illumination and the imaging are separated from each other, the three can be made to not interfere with each other, which can greatly improve the detection efficiency.

[0074] In summary, in the bright field detection, dark field detection and re-inspection performed by the optical detection equipment provided in the embodiment of the present invention, each field of view is separated, and the re-inspection optical path is integrated, which is conducive to improving the detection speed; the re-inspection optical path adopts a separate re-inspection light source 120, and a stroboscopic light source is used to solve the imaging smear problem caused by the rapid movement of the sample 191 to be inspected during the re-inspection; the bright field signal light, the dark field signal light and the re-inspection signal light are separated by collecting the reflective element 180 and the reflector element 183, and then received by the corresponding detector, which solves the problem of the signal light becoming weaker after splitting due to the use of a splitter prism and the like.

[0075] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the disclosure of the present invention can be performed in parallel, sequentially or in different orders, as long as the desired results of the technical solution disclosed in the present invention can be achieved, and this document does not limit this.

[0076] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An optical detection device, characterized in that: include: A re-test light source, the re-test light source emits re-test light, the re-test light is incident on the surface of the sample to be tested, and is reflected by the sample to be tested to form re-test signal light; A bright field light source emitting bright field light and a dark field light source emitting dark field light, the bright field light and the dark field light are respectively incident on the surface of the sample to be tested, the bright field light is reflected by the sample to be tested to form bright field signal light, the dark field light is scattered by the sample to be tested to form dark field signal light, and the bright field signal light, the dark field signal light and the re-test signal light are transmitted along a common optical path; A collecting reflective element, wherein the collecting reflective element is used to collect the bright field signal light and the dark field signal light and perform spatial separation, so that the bright field signal light is reflected into the first transmission path for bright field imaging, and the dark field signal light is reflected into the second transmission path for dark field imaging; A reflector element, the reflector element is arranged on the transmission path of the re-inspection signal light, and is used to reflect the re-inspection signal light to a third transmission path for re-inspection imaging; The re-test light is a stroboscopic light beam to reduce the smearing of the re-test signal light during re-test imaging, and the re-test signal light is totally reflected by the reflector element to reduce light intensity attenuation.

2. The optical detection device according to claim 1, characterized in that: The dark field signal light and the bright field signal light do not overlap each other when transmitted along the common optical path, and a distance between a dark field spot formed by the dark field light on the surface of the sample to be tested and a bright field spot formed by the bright field light on the surface of the sample to be tested is in a range of 0.2 mm to 3 mm.

3. The optical detection device according to claim 2, characterized in that: The re-inspection signal light does not overlap with the bright field signal light and the dark field signal light when being transmitted along the common optical path; The re-test light and the bright field light have a common transmission optical path, and the re-test light and the bright field light do not overlap each other during transmission.

4. The optical detection device according to claim 3, characterized in that: In the common optical path, the recheck signal light is located between the dark field signal light and the bright field signal light, and the recheck signal light, the dark field signal light and the bright field signal light are kept non-overlapping by mutual spatial isolation.

5. The optical detection device according to claim 2, characterized in that: The partial beam path of the re-test light coincides with the partial beam path of the bright field light, and the partial beam path of the bright field signal light coincides with the partial beam path of the re-test signal light; The optical detection device further comprises a first reflector group, which is used to be moved to the beam path of the bright field light during re-inspection, and guide the re-inspection light to the surface of the sample to be inspected through the first reflector group by shielding the bright field light; and the reflector element is used to be moved to the beam path of the bright field signal light, and reflect the re-inspection signal light to the third transmission path through the reflector element; When performing bright field detection, the first reflector group is also used to be moved out of the beam path of the bright field light, and the reflector element is also used to be moved out of the beam path of the bright field signal light.

6. The optical detection device according to claim 1, characterized in that: The collecting and reflecting element includes a first reflecting surface and a second reflecting surface. The bright field signal light incident to the collecting and reflecting element enters the first transmission path after being reflected by the first reflecting surface, and the dark field signal light incident to the collecting and reflecting element enters the second transmission path after being reflected by the second reflecting surface.

7. The optical detection device according to claim 6, characterized in that: The optical detection device also includes: A first detector, which is disposed on the first transmission path and is used to image the bright field signal light emitted by the collecting and reflecting element; a second detector, the second detector being disposed on the second transmission path and used for imaging the dark field signal light emitted by the collecting reflective element; A third detector is provided in the third transmission path, and is used for imaging the re-test signal light emitted by the reflector element.

8. The optical detection device according to claim 7, characterized in that: The collecting reflection element is a trapezoidal prism, the first reflection surface and the second reflection surface are respectively arranged on two inclined side surfaces of the trapezoidal prism, the first transmission path, the second transmission path and the third transmission path are all distributed in the same horizontal plane, and the first detector, the second detector and the third detector are arranged on the same horizontal platform surface to reduce the influence of the vibration of the horizontal platform surface on imaging.

9. The optical detection device according to claim 7, characterized in that: The bright field light source and the dark field light source include continuous light sources, the re-inspection light source includes a stroboscopic light source, the first detector and the second detector include line scan cameras, and the third inspection detector includes a color array camera.

10. The optical detection device according to claim 7, characterized in that: The optical detection equipment also includes: an objective lens and a spectroscopic element arranged in sequence along a direction away from the sample to be tested, the re-test light and the bright field light are sequentially incident on the surface of the sample to be tested through the spectroscopic element and the objective lens, the bright field signal light and the dark field signal light are sequentially incident on the collecting reflection element through the objective lens and the spectroscopic element, and the re-test signal light is sequentially incident on the reflector element through the objective lens and the spectroscopic element.

11. The optical detection device according to claim 10, characterized in that: The optical detection device also includes an imaging mirror group, which is arranged between the spectroscopic element and the collecting and reflecting element, and also between the spectroscopic element and the reflector element. The bright field signal light and the dark field signal light emitted from the spectroscopic element are both collected by the collecting and reflecting element through the imaging mirror group, and the re-inspection signal light emitted from the spectroscopic element is incident on the reflector element through the imaging mirror group.

12. The optical detection device according to claim 11, characterized in that: The target surface size of the first detector is the same as the target surface size of the second detector, and the imaging field of view of the imaging lens assembly satisfies the following formula: Where D is the diameter of the imaging field of view, l is the length of the target surface, w is the width of the target surface, and d is the interval between the bright field and the dark field.

13. The optical detection device according to claim 10, characterized in that: The optical detection equipment also includes a re-inspection illumination modulator mirror group, a first reflector group and an illumination mirror group arranged between the re-inspection light source and the spectroscopic element. The re-inspection light emitted by the re-inspection light source passes through the re-inspection illumination modulator mirror group, the first reflector group and the illumination mirror group in sequence and is incident on the spectroscopic element.

14. The optical detection device according to claim 10, characterized in that: The objective lens includes a plurality of sub-objective lenses, each of which has a different magnification. One of the plurality of sub-objective lenses is located in a light beam transmission path between the beam splitting element and the sample to be tested, and the sub-objective lens located in the light beam transmission path is switchable.

15. The optical detection device according to claim 10, characterized in that: The optical detection equipment also includes an automatic focusing module, which includes an automatic focusing light source and a dichroic mirror. The dichroic mirror is arranged between the spectroscopic element and the objective lens. The automatic focusing light source is used to emit focused light, and the focused light is guided by the dichroic mirror to irradiate the surface of the sample to be inspected. The wavelength of the focused light is different from the wavelength of the re-inspection light, the wavelength of the bright field light, the wavelength of the dark field signal light, the wavelength of the bright field signal light, and the wavelength of the re-inspection signal light.

16. A control method for an optical detection device, characterized in that: include: Providing an optical detection device, the optical detection device comprising a bright field light source, a dark field light source, a re-inspection light source, an objective lens, a collection reflection element, and a reflector element; The control method of the optical detection device comprises: Performing a preliminary inspection on the sample to be inspected, switching the magnification of the objective lens to a first magnification, controlling the bright field light source to emit bright field light, and controlling the dark field light source to emit dark field light, the bright field light irradiates the sample to be inspected so that the sample to be inspected emits bright field signal light, the dark field light irradiates the sample to be inspected so that the sample to be inspected scatters dark field signal light, the dark field signal light and the bright field signal light do not overlap with each other, and the dark field signal light and the bright field signal light are transmitted along a common optical path through the objective lens and collected by the collecting reflective element, the collecting reflective element spatially separates the bright field signal light and the dark field signal light, so that the bright field signal light is reflected into a first transmission path for bright field imaging, and the dark field signal light is entered into a second transmission path for dark field imaging; The sample to be inspected is re-inspected, the magnification of the objective lens is switched to a second magnification, the second magnification is greater than the first magnification, the re-inspection light source is controlled to emit re-inspection light, the re-inspection light is incident on the surface of the sample to be inspected, and is reflected by the sample to form re-inspection signal light, the re-inspection signal light passes through the objective lens and is reflected by the reflector element to a third transmission path for re-inspection imaging, the re-inspection light is a stroboscopic light beam to weaken the smear generated by the re-inspection signal light during re-inspection imaging, and the re-inspection signal light is totally reflected by the reflector element to reduce light intensity attenuation.

17. The control method of the optical detection device according to claim 16, characterized in that: The preliminary inspection further includes: stepping the sample to be inspected along a first direction to perform the bright field imaging and the dark field imaging, and stepping the sample to be inspected along a second direction to perform the bright field imaging and the dark field imaging, the first direction being perpendicular to the second direction; The re-inspection further comprises: when the initial inspection detects that the sample to be inspected has defects, re-inspection imaging is performed on the location of the defects.

18. The control method of the optical detection device according to claim 16, characterized in that: The optical detection device further comprises a first reflector group, a partial beam path of the re-test light coincides with a partial beam path of the bright field light, and a partial beam path of the bright field signal light coincides with a partial beam path of the re-test signal light; The control method of the optical detection device further includes: when performing a re-inspection, moving the first reflector group to the beam path of the bright field light, so that the re-inspection light is guided to the surface of the sample to be inspected through the first reflector group, and simultaneously moving the reflector element to the beam path of the bright field signal light, so that the re-inspection signal light is reflected to the third transmission path through the reflector element; When performing bright field detection, the first reflector group is moved out of the beam path of the bright field light so that the bright field light is transmitted to the surface of the sample to be tested, and at the same time, the reflector element is moved out of the beam path of the bright field signal light so that the bright field signal light is transmitted into the first transmission path for bright field imaging.

Images