Line scanning confocal microscopy system

Abstract

The application relates to the technical field of defect detection, and particularly provides a line-scan confocal microscopic system. The line-scan confocal microscopic system comprises a light source assembly for emitting a first line beam; a polygon scanning galvanometer comprising a polygon galvanometer body, the polygon galvanometer body being arranged in the light path of the first line beam, for reflecting the first line beam and obtaining a second line beam; the polygon scanning galvanometer is rotatably arranged around an own axis, so that the second line beam scans a measured sample along a direction perpendicular to the polygon scanning galvanometer and forms a third line beam by reflection; a light splitting assembly is arranged in the light path of the first line beam; the light splitting assembly comprises a light splitting surface, the light splitting surface is used for reflecting the first line beam and transmitting the third line beam; and a detector assembly is arranged in the light path of the third line beam, for obtaining an image of the measured sample according to the third line beam. The line-scan confocal microscopic system provided by the application can improve the accuracy and efficiency of defect detection.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of defect detection, in particular to a line scanning confocal microscopic system. BACKGROUND

[0002] For the detection of defects of small size, especially the detection of defects on wafer surface, a confocal microscopic system is often used. In the confocal microscopic system, a galvanometer in X direction and Y direction is usually arranged, and the light spot can be scanned on each position of the surface of the sample to be measured by rotating the galvanometer. However, in fact, the speed of the galvanometer cannot change suddenly, that is, the speed deviates from the ideal set speed when the galvanometer is turned, which leads to that the exposure time of the edge of the picture is longer than that of the middle part, the edge of the picture is overexposed, and needs to be cropped, thereby affecting the detection efficiency. SUMMARY

[0003] In view of the above analysis, the present application aims to provide a line scanning confocal microscopic system which can improve the accuracy and efficiency of defect detection.

[0004] The purpose of the present application is mainly achieved by the following technical solutions:

[0005] The line scanning confocal microscopic system provided by the present application comprises: a light source assembly for emitting a first linear light beam; a polygonal scanning galvanometer comprising a polygonal galvanometer body, the polygonal galvanometer body being arranged in the light path of the first linear light beam and being used for reflecting the first linear light beam and obtaining a second linear light beam; the polygonal scanning galvanometer being rotatably arranged about its own axis to make the second linear light beam scan a sample to be measured along a direction perpendicular to the polygonal scanning galvanometer and reflect to form a third linear light beam; a light splitting assembly arranged in the light path of the first linear light beam; the light splitting assembly comprising a light splitting surface, the light splitting surface being used for reflecting the first linear light beam and being used for transmitting the third linear light beam; and a detector assembly arranged in the light path of the third linear light beam and used for obtaining an image of the sample to be measured according to the third linear light beam.

[0006] According to the present application, the polygonal galvanometer body is in the shape of a prism, and the cross section perpendicular to the axis of the polygonal galvanometer body is in the shape of a regular polygon; the polygonal galvanometer body comprises a plurality of side wall surfaces, and the side wall surfaces are used for reflecting the first linear light beam.

[0007] According to the present application, the polygonal galvanometer body is in the shape of a regular hexadecagonal prism, and the rotation speed of the polygonal galvanometer body is 20000-45000 revolutions per minute.

[0008] According to the present application, the polygonal scanning galvanometer further comprises a driving assembly for driving the polygonal galvanometer body to rotate about its own axis.

[0009] According to the embodiment of the present application, the light source assembly comprises: a laser for emitting a laser beam, the laser beam being parallel light; a beam expander arranged in the light path of the laser beam for expanding the laser beam; a plano-convex cylindrical lens arranged in the light path of the laser beam for converging the expanded laser beam into a first linear light beam, the first linear light beam being a linear light source light beam; and an axis of the cylindrical surface of the plano-convex cylindrical lens being parallel to an axis of the polygon mirror body.

[0010] According to the embodiment of the present application, the light source assembly further comprises: a converging lens group arranged in the light path of the second linear light beam for converging the second linear light beam, and for converging the third linear light beam; and a reflector arranged on a side of the converging lens group away from the polygon mirror body along the light path direction of the second linear light beam, the reflector being configured to reflect the second linear light beam so that the reflected second linear light beam is directed to the sample under test, and the reflector being configured to reflect the third linear light beam so that the reflected third linear light beam is directed to the polygon scanning mirror.

[0011] According to the embodiment of the present application, the converging lens group comprises: a scanning lens and a tube lens; the scanning lens being a convex lens, and the scanning lens being arranged on a side of the tube lens close to the polygon mirror body along the light path direction of the second linear light beam.

[0012] According to the embodiment of the present application, the plano-convex cylindrical lens and the scanning lens constitute a four-fold focal length optical system; and the scanning lens and the tube lens constitute a four-fold focal length optical system.

[0013] According to the embodiment of the present application, the detector assembly comprises: a condenser lens arranged on a side of the light splitting assembly away from the mirror along the light path direction of the third linear light beam, the condenser lens being configured to converge the transmitted third linear light beam; and a linear array detector arranged on a side of the condenser lens away from the light splitting assembly along the light path direction of the third linear light beam, the linear array detector being configured to detect the third linear light beam.

[0014] According to the embodiment of the present application, the linear array detector comprises a linear array back-illuminated charge-coupled device camera, the linear array back-illuminated charge-coupled device camera having a longitudinal pixel number of at least 8192, a minimum line time of less than or equal to 4 μs, a dynamic range of greater than 66.7 dB, and a maximum line speed of greater than or equal to 200 kHz.

[0015] Compared with the prior art, the present application has at least the following beneficial effects:

[0016] In the line-scan confocal microscopic system of the embodiment of the present application, the light source assembly emits a first line beam, the first line beam is reflected by the light splitting surface of the light splitting assembly, the reflected first line beam is reflected by the polygon mirror body of the polygon scanning galvanometer to form a second line beam, the second line beam is reflected by the surface of the measured sample to form a third line beam, the third line beam is reflected by the polygon mirror body again and is transmitted by the light splitting assembly and is detected by the detector assembly. The polygon mirror body rotates, each side surface can reflect the first line beam, with the rotation of the polygon mirror body, the second line beam also rotates to scan the surface of the measured sample in one direction, and the surface image of the measured sample can be obtained by combining the third line beam collected by the detector assembly. The line-scan confocal microscopic system of the embodiment of the present application adopts a line light source combined with one-way scanning to obtain the surface image of the measured sample, and the efficiency of defect detection can be improved. When continuous multiple scanning is performed, in the process of a certain scanning, the polygon mirror body can rotate at a preset speed, so that the second line beam scans the surface of the measured sample at a preset speed, so that the exposure amount of each part of the image is basically consistent, the accuracy of detection is improved, the process of image cropping and excessive detection is saved, and the efficiency of defect detection is improved.

[0017] In the present application, the above technical solutions can also be combined with each other to realize more preferred combination solutions. Other features and advantages of the present application will be described in the subsequent description, and some advantages will become apparent from the description, or will be understood by implementing the present application. The purposes and other advantages of the present application can be realized and obtained from the contents specifically pointed out in the description and the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0018] The accompanying drawings are included to provide a further understanding of the embodiments, and are incorporated in and constitute a part of this application. The same reference numerals refer to the same components throughout the drawings.

[0019] Figure 1 It is a structural schematic diagram of the line-scan confocal microscopic system of the embodiment of the present application.

[0020] Figure 2 It is a structural schematic diagram of the line-scan confocal microscopic system of the embodiment of the present application in a plane parallel to the plane where the measured sample is located.

[0021] Figure 3 It is a structural schematic diagram of the line-scan confocal microscopic system of the embodiment of the present application in a plane perpendicular to the plane where the measured sample is located.

[0022] Reference signs:

[0023] 1, light source assembly; 11, laser; 12, beam expander; 13, plano-convex cylindrical lens;

[0024] 2, polygonal scanning galvanometer; 21, polygonal galvanometer body; 211, side wall surface; 22, driving assembly;

[0025] 3, light splitting assembly;

[0026] 4, detector assembly; 41, light collecting lens; 42, linear array detector;

[0027] 5, converging lens assembly; 51, scanning lens; 52, tube lens;

[0028] 6, reflecting mirror;

[0029] 7, sample to be measured;

[0030] L1, first linear light beam; L2, second linear light beam; L3, third linear light beam; R, laser beam. DETAILED DESCRIPTION

[0031] The preferred embodiments of the present application will be described in detail below with reference to the drawings, in which the figures constitute a part of the present application and illustrate the principles of the present application together with the embodiments of the present application, but are not intended to limit the scope of the present application.

[0032] In the description of the embodiments of the present application, it should be noted that unless otherwise explicitly specified and limited, the term "connected" should be understood in a broad sense, for example, it can be fixedly connected, or detachably connected, or integrally connected, which can be mechanically connected, or electrically connected, which can be directly connected, or indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above-mentioned term in the present application can be understood according to the specific circumstances.

[0033] The terms "top", "bottom", "above", "under" and "on" used throughout the description are relative positions of the components of the device, for example, the relative positions of the top and bottom substrates inside the device. It can be understood that the device is multifunctional, regardless of their orientation in space.

[0034] The applicant finds that when a confocal microscopy system is used for defect detection, the confocal microscopy system uses a point light source and sets up galvanometers in the X direction and the Y direction, rotates the galvanometers to make the point light source scan each position of the sample to be detected in turn, detects the reflected light or scattered light of the sample to be detected, splices to generate an image of the surface of the sample to be detected, and judges whether the sample to be detected has defects according to the image. Considering that the light beam needs to be adjusted in position along the X direction and the Y direction to scan the sample to be detected, the detection efficiency is low. In addition, when the galvanometer rotates and reflects the light beam, the smaller the included angle between the light beam and the reflecting surface of the galvanometer per unit time, the greater the angle of rotation of the light beam, and the greater the distance swept on the surface of the sample to be detected, that is, the speed of the light beam scanning the surface of the sample to be detected is not uniform, especially when scanning is changed, a snake-shaped scan is usually used, and the rotation angle control of the galvanometer presents a characteristic of a chord function at the edge of the sample to be detected, cannot be completely switched at an instant speed, and thus deviates from the preset speed, resulting in that the exposure time of the edge of the picture is longer than that of the middle, so that the edge of the image is overexposed, which affects the accuracy of defect detection. In order to obtain a complete image of the sample to be detected, an area outside the sample to be detected also needs to be over-scanned to avoid the image of the edge of the sample to be detected being cropped, which affects the detection efficiency.

[0035] In view of the above analysis, the applicant proposes a line-scan confocal microscopy system, which comprises a light source assembly, a polygonal scanning galvanometer, a light splitting assembly and a detector assembly. The light source assembly emits a first linear light beam. The first linear light beam is reflected by a light splitting surface of the light splitting assembly. The reflected first linear light beam is reflected by a polygonal galvanometer body of the polygonal scanning galvanometer to form a second linear light beam. The second linear light beam is irradiated on the surface of the sample to be detected to form a third linear light beam. The third linear light beam is reflected by the polygonal galvanometer body again and transmitted through the light splitting assembly and is detected by the detector assembly. The polygonal galvanometer body rotates, and each side surface can reflect the first linear light beam. As the polygonal galvanometer body rotates, the second linear light beam also rotates to scan the surface of the sample to be detected in one direction. The surface image of the sample to be detected can be obtained by splicing the third linear light beam collected by the detector assembly. The line-scan confocal microscopy system of the present application uses a linear light source combined with one-way scanning to obtain the surface image of the sample to be detected, which can improve the efficiency of defect detection. When continuous multiple scanning is performed, the polygonal galvanometer body can rotate at a preset speed during the process of a certain scanning, so that the second linear light beam scans the surface of the sample to be detected at a preset speed, thereby making the exposure amount of each part of the image substantially consistent, improving the accuracy of detection, eliminating the process of image cropping and over-detection, and improving the efficiency of defect detection.

[0036] Figure 1 A structural schematic diagram of the line-scan confocal microscopy system of the present application. Figure 2A structural schematic diagram of a line-scan confocal microscopic system of an embodiment of the present application in a plane parallel to a plane where a measured sample is located. Figure 3 A structural schematic diagram of a line-scan confocal microscopic system of an embodiment of the present application in a plane vertical to a plane where a measured sample is located.

[0037] Please refer to Figures 1 to 3 The line-scan confocal microscopic system of the embodiment of the present application comprises a light source assembly 1, a polygonal scanning galvanometer 2, a light splitting assembly 3 and a detector assembly. The light source assembly 1 emits a first linear light beam L1. The light source assembly 1 is configured to emit the first linear light beam L1. The polygonal scanning galvanometer 2 comprises a polygonal galvanometer body 21. The polygonal galvanometer body 21 is arranged in an optical path of the first linear light beam L1 and is configured to reflect the first linear light beam L1 and obtain a second linear light beam L2. The polygonal scanning galvanometer 2 is rotatably arranged around an axis thereof, so that the second linear light beam L2 scans a measured sample 7 in a direction perpendicular to the polygonal scanning galvanometer 2 and forms a third linear light beam L3 by reflection. The light splitting assembly 3 is arranged in the optical path of the first linear light beam L1. The light splitting assembly 3 comprises a light splitting surface. The light splitting surface is configured to reflect the first linear light beam L1 and transmit the third linear light beam L3. The detector assembly 4 is arranged in an optical path of the third linear light beam L3 and is configured to obtain an image of the measured sample 7 according to the third linear light beam L3. Exemplarily, the first linear light beam L1 is perpendicular to the second linear light beam L2, which facilitates the arrangement of positions of various devices of the line-scan confocal microscopic system of the embodiment of the present application.

[0038] The line-scan confocal microscopic system of the embodiment of the present application is used for defect detection. Exemplarily, the measured sample 7 can be a device such as a wafer. In this case, the line-scan confocal microscopic system of the embodiment of the present application is used to detect whether there is a defect on a surface of the wafer.

[0039] The light source assembly 1 is used to emit a first linear light beam L1, which can be regarded as a linear light source. The light splitting assembly 3 is used to split light and has a light splitting surface, which can reflect light and also transmit light. The light splitting surface can reflect the first linear light beam L1, which is reflected by the light splitting surface and then irradiates the polygonal scanning galvanometer 2. The polygonal galvanometer body 21 of the polygonal scanning galvanometer 2 has a plurality of side surfaces corresponding to the edges of the polygon, and each side surface can reflect the first linear light beam L1. The first linear light beam L1 irradiates a certain side surface and is reflected to form a second linear light beam L2. The second linear light beam L2 irradiates a certain position of the measured sample 7 and is reflected to form a third linear light beam L3. The third linear light beam L3 is reversely irradiated and is reflected again by the polygonal galvanometer body 21, and the reflected third linear light beam L3 irradiates the light splitting assembly 3. The light splitting surface of the light splitting assembly 3 transmits the third linear light beam L3, and the transmitted third linear light beam L3 irradiates the detector assembly 4. The detector assembly 4 collects the third linear light beam L3 and generates an image of the position of the measured sample 7. Exemplarily, the light splitting assembly 3 can use a polarization beam splitter or a dichroic mirror. If the detector assembly 4 detects fluorescence emitted by the measured sample 7, the light splitting assembly 3 selects a dichroic mirror and adds a fluorescence filter. If the detector assembly 4 detects reflected light reflected by the measured sample 7, the light splitting assembly 3 selects a polarization beam splitter and adds a quarter-wave plate.

[0040] It can be understood that the line scanning confocal microscopic system of the embodiment of the present application further includes a stage for carrying and fixing the measured sample 7. The stage should be able to translate to adjust the position of the measured sample 7. Exemplarily, the stage can adjust the position along the orthogonal direction of the plane in which the stage is located.

[0041] The polygonal galvanometer body 21 is rotated, so that the incident angle of the first linear light beam L1 with the side surface of the polygonal galvanometer body 21 gradually changes, so that the second linear light beam L2 also rotates, and the rotation angle is twice the rotation angle of the polygonal galvanometer body 21. Thus, under the premise that the first linear light beam L1 does not change, the second linear light beam L2 can sweep along the tangential direction of the axis of the polygonal galvanometer body 21, thereby realizing scanning of the surface of the measured sample 7. Since the first linear light beam L1 is a linear light source, the third linear light beam L3 can also be regarded as a linear light beam. Therefore, when the second linear light beam L2 sweeps in a single direction, the surface of the measured sample 7 is scanned in a single direction. After the detector assembly 4 obtains the image corresponding to the third linear light beam L3, the image is spliced along the scanning direction, and the surface image of the measured sample 7 can be obtained, which can be used as a basis for judging whether there is a defect on the surface of the measured sample 7.

[0042] In the detection process, when the first linear light beam L1 changes from the edge of a side surface to the edge of another side surface at the irradiation position of the polygon mirror body 21, the corresponding second linear light beam L2 can realize the first scan of the measured sample 7; continue to rotate the polygon mirror body 21, when the first linear light beam L1 switches from the side surface to the adjacent side surface at the irradiation position of the polygon mirror body 21, the irradiation position of the corresponding second linear light beam L2 jumps from the end position of the first scan to the initial position of the second scan; continue to rotate the polygon mirror body 21, when the first linear light beam L1 changes from the edge of the adjacent side surface to the edge of another side surface at the irradiation position of the polygon mirror body 21, the corresponding second linear light beam L2 can realize the second scan of the measured sample 7. By analogy, the line-scan confocal microscopic system of the embodiment of the application can perform continuous multiple scans on the measured sample 7, and the rotational angular velocity of the polygon mirror body 21 is unchanged during each scan, and the edge of the measured sample 7 can also be regarded as uniform speed scanning, which saves image cropping and excessive detection of areas outside the measured sample 7, thereby improving the detection efficiency and the accuracy of the detection. Through continuous scanning, the line-scan confocal microscopic system of the embodiment of the application can also increase the size of the field of view, and is suitable for processing large-size samples and dynamic sample detection. Exemplarily, the line-scan confocal microscopic system of the embodiment of the application can realize real-time observation of high-resolution imaging of living cells and tissue sections, especially when dynamic monitoring of rapid biological processes (such as cell division, molecular positioning, etc.) is required; the line-scan confocal microscopic system of the embodiment of the application can also be used for rapid scanning of surface defects, material surface microstructure analysis, etc. in high-precision manufacturing or quality control, and is especially suitable for the fields of semiconductor and microelectronic component manufacturing; the line-scan confocal microscopic system of the embodiment of the application can also be used for nanoscale characterization and analysis, such as surface morphology and thickness measurement of nanoparticles and thin films; the line-scan confocal microscopic system of the embodiment of the application can also be used in environmental science to rapidly scan large-area environmental samples (such as soil, air, water samples, etc.) and analyze their microstructure or component distribution.

[0043] In addition, due to the relatively stable rotation mode of the polygon mirror body 21, the motion impact generated during acceleration and deceleration can be reduced, so that the line-scan confocal microscopic system of the embodiment of the application can have a more stable motion state and structural stability, thereby prolonging the service life.

[0044] Further, referring to Figures 1 to 3 , the polygon mirror body 21 is prismatic, and the cross section perpendicular to the axis direction of the polygon mirror body 21 is a regular polygon; the polygon mirror body 21 comprises a plurality of side wall surfaces 211, and the side wall surface 211 is used for reflecting the first linear light beam L1.

[0045] The polygonal mirror body 21 adopts the shape of a regular polygonal prism, and the corresponding axis during rotation is the geometric axis of the prism. During a single scan using the line-scan confocal microscopic system of the embodiment of the present application, as the polygonal mirror body 21 rotates, the irradiation position of the first line beam L1 on the polygonal mirror body 21 gradually moves from the edge of a certain side wall surface 211 to the edge of another side wall surface. During continuous multiple scans using the line-scan confocal microscopic system of the embodiment of the present application, as the polygonal mirror body 21 rotates, the irradiation position of the first line beam L1 on the polygonal mirror body 21 moves between multiple adjacent side wall surfaces 211, and since the shape and size of each side wall surface 211 are the same, the range of each scan is the same.

[0046] Further, referring to Figures 1 to 3 , the polygonal mirror body 21 is in the shape of a regular hexadecagonal prism, and the rotation speed of the polygonal mirror body 21 is 20,000-45,000 revolutions per minute.

[0047] When a certain side wall surface 211 reflects the first line beam L1, the smaller the normal angle of the first line beam L1 relative to the side wall surface 211, the closer the corresponding scanning process is to uniform speed after the uniform rotation of the second line beam L2 is converted into scanning of the measured sample 7 by the second line beam L2, the more uniform the overall exposure of the image obtained according to the third line beam L3, the more accurate the judgment of the defects of the measured sample 7, and the smaller the area of the surface of the measured sample 7 that can be scanned by the second line beam L2. The regular hexadecagonal prism has a proper central angle, and the included angle between two adjacent side wall surfaces 211 is 157.5°, which can ensure that the first line beam L1 does not have an excessively large normal angle relative to the side wall surface 211 and that the scanning of the second line beam L2 is sufficiently large and can irradiate each position of the measured sample 7. The polygonal mirror body 21 rotates at a uniform speed, and the faster the rotation, the faster the scanning speed and the lower the degree of exposure. With a rotation speed of 20,000-45,000 revolutions per minute, the degree of exposure of each position of the measured sample 7 is moderate under the premise of ensuring detection efficiency, and the obtained image is clearer. Exemplarily, the area of a single side wall surface 211 is 7 mm x 4.5 mm.

[0048] Further, the polygonal scanning mirror 2 further comprises a driving assembly 22 that drives the polygonal mirror body 21 to rotate about its own axis. Exemplarily, the driving assembly 22 can adopt the form of a motor to directly or indirectly drive the polygonal mirror body 21 to rotate, for example, the motor drives the polygonal mirror body 21 to rotate through a gear set.

[0049] Further, referring to Figures 1 to 3The light source assembly 1 comprises a laser 11 for emitting a laser beam R, the laser beam R being parallel light; a beam expander 12 arranged in the light path of the laser beam R for expanding the laser beam R; and a plano-convex cylindrical lens 13 arranged in the light path of the laser beam R for converging the expanded laser beam R into a first linear light beam L1, the first linear light beam L1 being a linear light source light beam; and the axis of the cylindrical surface of the plano-convex cylindrical lens 13 is parallel to the axis of the polygon mirror body 21.

[0050] The laser 11 can be a semiconductor single-mode spatial collimation laser 11, and the wavelength of the generated laser beam R can be 488 nm, corresponding to a point light source, and the spot diameter is 1.2 mm. In addition, the power stability requirement of the laser 11 is within 1%, and the output power of the laser 11 can be adjustable in the range of 0-20 mW, and the output power adjustment accuracy is 0.1%.

[0051] The beam expander 12 is used for expanding the laser beam R, and at least can expand the laser beam R by 5 times, so that the spot diameter of the expanded laser beam R can reach 6 mm.

[0052] The plano-convex cylindrical lens 13 is provided with a cylindrical surface on one side, which can converge the expanded laser beam R along the line to form a first linear light beam L1, and the first linear light beam L1 is a linear light source, and the length direction is parallel to the axis direction of the cylindrical surface of the convex cylindrical lens. Subsequently, the length directions of the second linear light beam L2 and the third linear light beam L3 are consistent with the length direction of the first linear light beam L1. The axis of the cylindrical surface of the plano-convex cylindrical lens 13 is parallel to the axis of the polygon mirror body 21, so that the length direction of the second linear light beam L2 is perpendicular to the scanning direction, thereby fully utilizing the second linear light beam L2. Exemplarily, the focal length of the plano-convex cylindrical lens 13 can be 100 mm.

[0053] Further, continuing to refer to Figures 1 to 3 The line scanning confocal microscopic system of the embodiment of the present application further comprises a converging lens group 5 arranged in the light path of the second linear light beam L2 for converging the second linear light beam L2 and the third linear light beam L3; and a reflecting mirror 6 arranged on the side of the converging lens group 5 away from the polygon mirror body 21 along the light path direction of the second linear light beam L2, the reflecting mirror 6 is used for reflecting the second linear light beam L2 so that the reflected second linear light beam L2 is directed to the measured sample 7, and the reflecting mirror 6 is used for reflecting the third linear light beam L3 so that the reflected third linear light beam L3 is directed to the polygon scanning mirror 2.

[0054] The converging lens group 5 can converge the second linear light beam L2 to focus the second light beam, so as to improve the final imaging accuracy. When the second linear light beam L2 is reflected by the measured sample 7 to form the third linear light beam L3, the third linear light beam L3 is in a divergent state, and the converging lens group 5 can make the third linear light beam L3 converge again into parallel light, so as to facilitate the acquisition of imaging by the detector assembly 4.

[0055] The mirror 6 can change the direction of the second linear light beam L2 so that the second linear light beam L2 can irradiate the measured sample 7 more vertically. Exemplarily, the plane formed after the sweep of the second linear light beam L2 before being reflected by the mirror 6 is perpendicular to the second linear light beam L2 after being reflected by the mirror 6, and the plane is parallel to the plane where the measured sample 7 is located. It can be understood that the second linear light beam L2 after being reflected by the mirror 6 will be directed to the measured sample 7, so the objective lens can be installed on the side of the mirror 6 close to the measured sample 7.

[0056] Further, referring to Figures 1 to 3 , the converging lens group 5 includes a scanning lens 51 and a tube lens 52; the scanning lens 51 is a convex lens, and the scanning lens 51 is arranged on the side of the tube lens 52 close to the polygon mirror body 21 along the light path direction of the second linear light beam L2.

[0057] In the embodiment of the application, the second linear light beam L2 sweeps a larger area at the scanning lens 51, and the scanning lens 51 can converge the second linear light beam L2, appropriately reducing the area swept by the second linear light beam L2, so as to facilitate the scanning of the measured sample 7. Exemplarily, the scanning lens 51 adopts the form of a convex lens, and the focal length is 100 mm, and the distance between the scanning lens 51 and the polygon mirror body 21 is 100 mm. The liquid crystal of the tube lens 52 can converge the second linear light beam L2, so that the second linear light beam L2 after convergence can enter the objective lens. Exemplarily, the tube lens 52 adopts the form of a convex lens, and the focal length is 180 mm, and the distance between the tube lens 52 and the scanning lens 51 is 280 mm.

[0058] Further, referring to Figures 1 to 3 , the plano-convex cylindrical lens 13 and the scanning lens 51 constitute a four-fold focal length optical system, which can filter the first linear light beam L1 and the second linear light beam L2, reducing the influence of stray light; the scanning lens 51 and the tube lens 52 constitute a four-fold focal length optical system, which can filter the second linear light beam L2 and the third linear light beam L3, reducing the influence of stray light. After filtering, the image obtained by the line-scan confocal microscopic system of the embodiment of the application is more accurate. The two four-fold focal length optical systems share the scanning lens 51, which can simplify the structure of the line-scan confocal microscopic system of the embodiment of the application.

[0059] Further, referring to Figures 1 to 3 , the detector assembly 4 includes a condenser lens 41 arranged on the side of the light splitting assembly 3 away from the mirror along the light path direction of the third linear light beam L3, the condenser lens 41 being used for converging the third linear light beam L3 after transmission; and a linear array detector 42 arranged on the side of the condenser lens 41 away from the light splitting assembly 3 along the light path direction of the third linear light beam L3; the linear array detector 42 being used for detecting the third linear light beam L3.

[0060] The light collecting lens 41 can converge the third linear light beam L3 after transmission, and the converged third linear light beam L3 is more easily received by the linear array detector 42 to obtain an image of the measured sample 7. Exemplarily, the focal length of the light collecting lens 41 is 100 mm. The linear array detector 42 includes a linear array back-illuminated charge-coupled device camera (CCD camera), the number of longitudinal pixels of the linear array back-illuminated charge-coupled device camera is at least 8192, the minimum line time is less than or equal to 4 μs, the dynamic range is greater than 66.7 dB, and the maximum line speed is greater than or equal to 200 kHz. The light signal of the third linear light beam L3 received by the linear array detector 42 obtains an electrical signal containing image information, and transmits the electrical signal to a data processing host, generates an image of the measured sample 7 according to the image information, and exemplarily, the data processing host can adopt the form of a capture card combined with a computer. Considering that the rotating speed of the polygonal mirror body 21 can be 20,000-45,000 revolutions per minute, the frame rate of the linear array detector 42 cooperating with the generation of the image can exceed 200 FPS, which is much higher than the frame rate of 30 FPS of the point scanning system.

[0061] In summary, the embodiment of the present application provides a line scanning confocal microscopic system. The light source assembly emits a first linear light beam, the first linear light beam is reflected by the light splitting surface of the light splitting assembly, the reflected first linear light beam is reflected by the polygonal mirror body of the polygonal scanning mirror to form a second linear light beam, the second linear light beam is irradiated on the surface of the measured sample to form a third linear light beam, the third linear light beam is reflected again by the polygonal mirror body and transmitted through the light splitting assembly and detected by the detector assembly. The polygonal mirror body rotates, each side surface can reflect the first linear light beam, as the polygonal mirror body rotates, the second linear light beam also rotates, thereby unidirectionally scanning the surface of the measured sample, and the surface image of the measured sample can be obtained by combining the third linear light beam collected by the detector assembly. The line scanning confocal microscopic system of the embodiment of the present application adopts a linear light source combined with unidirectional scanning to obtain the surface image of the measured sample, which can improve the efficiency of defect detection. When continuous multiple scanning is performed, the polygonal mirror body can rotate at a preset speed during the process of a certain scanning, so that the second linear light beam scans the surface of the measured sample at a preset speed, thereby making the exposure amount of each part of the image substantially consistent, improving the accuracy of detection, eliminating the process of image cropping and excessive detection, and improving the efficiency of defect detection.

[0062] The above merely describes a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which shall be covered within the protection scope of the present application.

Claims

1. A line-scan confocal microscopy system, characterized by, The application relates to a polygonal scanning galvanometer, which comprises the following components: a light source assembly for emitting a first linear light beam; a polygonal scanning galvanometer, which comprises a polygonal galvanometer body arranged in the light path of the first linear light beam, is used for reflecting the first linear light beam, and obtains a second linear light beam; the polygonal scanning galvanometer is rotatably arranged around its own axis to make the second linear light beam scan a measured sample along a direction perpendicular to the polygonal scanning galvanometer and reflect to form a third linear light beam; the polygonal galvanometer body is prismatic, and the shape of the cross section perpendicular to the direction of the axis of the polygonal galvanometer body is a regular polygon; the polygonal galvanometer body comprises a plurality of side wall surfaces, and the side wall surfaces are used for reflecting the first linear light beam; the polygonal galvanometer body is a regular hexadecagonal prism, and the polygonal galvanometer body rotates at a uniform speed to make the second linear light beam uniformly scan the measured sample; a light splitting assembly arranged in the light path of the first linear light beam; the light splitting assembly comprises a light splitting surface, which is used for reflecting the first linear light beam and transmitting the third linear light beam; a detector assembly arranged in the light path of the third linear light beam and used for obtaining an image of the measured sample according to the third linear light beam; the detector assembly comprises a light collecting lens and a linear array detector; along the light path direction of the third linear light beam, the light collecting lens is arranged on the side of the light splitting assembly away from the galvanometer, and the light collecting lens is used for converging the transmitted third linear light beam to make the third linear light beam be received by the linear array detector to obtain the image of the measured sample; along the light path direction of the third linear light beam, the linear array detector is arranged on the side of the light collecting lens away from the light splitting assembly; and the linear array detector is used for detecting the third linear light beam.

2. The line-scan confocal microscopy system of claim 1, wherein, The rotating speed of the polygonal galvanometer body is 20000-45000 revolutions per minute.

3. The line-scan confocal microscopy system of claim 1, wherein, The polygonal scanning galvanometer further comprises a driving assembly, which drives the polygonal galvanometer body to rotate around its own axis.

4. The line-scan confocal microscopy system of claim 1, wherein, The light source assembly comprises: a laser for emitting a laser beam, wherein the laser beam is parallel light; a beam expander arranged in the light path of the laser beam and used for expanding the laser beam; a plano-convex cylindrical lens arranged in the light path of the laser beam and used for converging the expanded laser beam into the first linear light beam, wherein the first linear light beam is linear light source light; and the axis of the cylindrical surface of the plano-convex cylindrical lens is parallel to the axis of the polygonal galvanometer body.

5. The line-scan confocal microscopy system of claim 4, wherein, Further comprising: a converging lens group arranged in the light path of the second linear light beam and used for converging the second linear light beam and the third linear light beam; a mirror arranged on the side of the converging lens group away from the polygonal galvanometer body along the light path direction of the second linear light beam, wherein the mirror is used for reflecting the second linear light beam to make the reflected second linear light beam shoot towards the measured sample, and the mirror is used for reflecting the third linear light beam to make the reflected third linear light beam shoot towards the polygonal scanning galvanometer.

6. The line-scan confocal microscopy system of claim 5, wherein, The converging lens group comprises a scanning lens and a tube lens; the scanning lens is a convex lens, and the scanning lens is arranged on the side of the tube lens close to the polygonal galvanometer body along the light path direction of the second linear light beam.

7. The line-scan confocal microscopy system of claim 6, wherein, The plano-convex cylindrical lens and the scanning lens constitute a four-fold focal length optical system; the scanning lens and the tube lens constitute a four-fold focal length optical system.

8. The line-scan confocal microscopy system of claim 1, wherein, The linear array detector comprises a linear array back-illuminated charge coupled device camera, a longitudinal pixel number of the linear array back-illuminated charge coupled device camera is at least 8192, a minimum line time is less than or equal to 4 mu s, a dynamic range is greater than 66.7 dB, and a maximum line speed is greater than or equal to 200 kHz.

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