Microscopic imaging system

Abstract

The embodiment of the invention provides a microscopic imaging system which is used for being matched with laser with the wave band of 266-520 nm so as to achieve high-resolution and high-speed detection of defects in an object to be detected. The microscopic imaging system comprises a microscope objective, a relay system, a diaphragm and a zoom system which are coaxially arranged from an object side to an image side, the working wave band of the microscope objective comprises [266nm, 520nm], the numerical aperture of the microscope objective is greater than 0.85, the microscope objective is used for collimating and emitting reflected light and / or scattered light of an object to be detected, and the relay system is used for transmitting the reflected light and / or scattered light of the object to be detected to the zoom system. The adjusting module is used for adjusting an exit pupil of the microscope objective to a diaphragm so as to amplify or reduce the size of a light beam collimated and emitted by the microscope objective; the diaphragm is used for modulating the size of an exit pupil of the microscope objective; and the zoom system is used for adjusting the focal length of the microscopic imaging system so as to focus the collimated light beams emitted by the relay system to focal planes with different focal lengths for imaging.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor detection technology, and in particular to a microscopic imaging system. Background Art

[0002] Semiconductor defect detection equipment is widely used in the semiconductor process chain, covering almost every process step, and is used to detect the qualification rate of the process.

[0003] Semiconductor defect detection equipment has two very important indicators: resolution and detection speed. Among them, the resolution is related to the working wavelength band and numerical aperture, and the detection rate is related to the light source intensity and instrument sensitivity. The existing design idea is to shorten the working wavelength band to extreme ultraviolet, such as 248nm or a wide wavelength band of 260 - 480nm.

[0004] With the development of technology, high-power lasers in the 266nm wavelength band have emerged on the market, and the frequency of 266nm can reach 20MHz with a power greater than 5W. This can improve both the resolution and the test rate. Therefore, the semiconductor defect detection technology based on 266nm will become one of the solutions.

[0005] However, in the existing technology, there is no microscopic imaging system with a large field of view and large numerical aperture for this wavelength band. Summary of the Invention

[0006] Embodiments of the present invention provide a microscopic imaging system for matching lasers in the wavelength band of 266 to 520nm to achieve high-resolution and high-detection-rate detection of semiconductor defects.

[0007] Embodiments of the present application provide a microscopic imaging system, including:

[0008] A microscopic objective lens, a relay system, a diaphragm, and a zoom system coaxially arranged from the object side to the image side, where:

[0009] The working wavelength band of the microscope objective lens includes [266nm, 520nm], and the numerical aperture of the microscope objective lens is greater than 0.85, which is used to collimate and emit the reflected light and / or scattered light of the object to be measured;

[0010] The relay system is used to adjust the exit pupil of the microscopic objective lens to the diaphragm to magnify or reduce the size of the beam collimated and emitted by the microscopic objective lens;

[0011] The diaphragm is used to modulate the size of the exit pupil of the microscopic objective lens;

[0012] The zoom system is used to adjust the focal length of the microscopic imaging system to focus the collimated beam emitted by the relay system onto focal planes with different focal lengths for imaging.

[0013] Preferably, the relay system includes a first positive focal length lens group and a second positive focal length lens group arranged along the direction of the collimated outgoing light beam, wherein both the first positive focal length lens group and the second positive focal length lens group include a plurality of lenses with positive and negative focal lengths cooperating with each other.

[0014] Preferably, if the first positive focal length lens group and the second positive focal length lens group cannot adjust the exit pupil of the microscope objective to the aperture stop, the relay system further includes:

[0015] A field lens disposed at the focal plane of the first positive focal length lens group.

[0016] Preferably, the first positive focal length lens group includes a combination of a plurality of positive lenses and a plurality of negative lenses, and the second positive focal length lens group includes a combination of a plurality of positive lenses and a plurality of negative lenses, wherein:

[0017] The first positive focal length lens group includes a first positive lens, a second negative lens, a third positive lens, and a fourth negative lens arranged in sequence along the propagation direction of the light beam;

[0018] The second positive focal length lens group includes a fifth positive lens, a sixth positive lens, a seventh negative lens, and an eighth positive lens arranged in sequence along the propagation direction of the light beam;

[0019] The field lens includes a ninth positive lens disposed near the focal plane of the first positive focal length lens group.

[0020] Preferably, the magnification of the relay system ranges from 0.5 times to 1 time.

[0021] Preferably, the distance between the relay system and the microscope objective is greater than 150 mm, and the distance between the last lens in the relay system along the propagation direction of the light beam and the exit pupil of the microscope objective is greater than 50 mm.

[0022] Preferably, the zoom system includes a third positive focal length lens group and a fourth negative focal length lens group.

[0023] Preferably, when the zoom system includes the third positive focal length lens group and the fourth negative focal length lens group arranged in sequence along the propagation direction of the light beam, the zoom system is a telephoto structure;

[0024] When the zoom system includes the fourth negative focal length lens group and the third positive focal length lens group arranged in sequence along the propagation direction of the light beam, the zoom system is a retrofocus structure.

[0025] Preferably, the magnification of the zoom system ranges from 40x to 100x, and the number of lens elements in the zoom system ranges from 3 to 5.

[0026] Preferably, when the magnification of the relay system is 1x and the zoom system includes a first lens, a second lens, and a third lens, then:

[0027] If the magnification of the zoom system ranges from 40x to 100x, then the zoom distance of the second lens ranges from 52 mm to 287 mm, the back working distance of the third lens ranges from 225 mm to 1403 mm, and the focal length range of the microscopic imaging system ranges from 600 mm to 1500 mm.

[0028] Preferably, when the magnification of the relay system is 0.5x and the zoom system includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens, then:

[0029] If the magnification of the zoom system ranges from 40x to 100x, then the zoom distance range of the fourth lens ranges from 20 mm to 136 mm, the back working distance range of the fifth lens ranges from 170 mm to 885 mm, and the focal length range of the microscopic imaging system ranges from 300 mm to 750 mm.

[0030] Preferably, the resolution of the microscopic objective lens is less than 0.3 µm, and the field of view is greater than 1.3 mm.

[0031] Preferably, the focal length range of the microscopic objective lens ranges from 8 mm to 20 mm.

[0032] From the above technical solutions, it can be seen that the embodiments of the present invention have the following advantages:

[0033] Since the microscopic objective lens in the microscopic imaging system in the embodiments of the present application can image a wavelength of 266 nm, the microscope objective lens in the embodiments of the present application can be matched with a high-power 266-nm laser, and the frequency of the 266-nm laser can reach 20 MHz and the power is greater than 5 W. Therefore, when the microscope objective lens in the embodiments of the present application is matched with a high-power 266-nm laser, on the one hand, the test rate for semiconductors can be improved. And the numerical aperture of the microscope objective lens in the embodiments of the present application is greater than 0.85. Therefore, on the premise that the wavelength of the incident light is fixed, the minimum distance between two object points that the microscope objective lens can resolve is smaller, that is, on the other hand, the microscope objective lens in the embodiments of the present application also improves the resolution of semiconductor defects. Description of the Drawings

[0034] Figure 1 It is a schematic diagram of an embodiment of the microscopic imaging system in the embodiments of the present application;

[0035] Figure 2 Schematic diagram of an embodiment of the relay system in the embodiment of the present application;

[0036] Figure 3 Schematic diagram of an embodiment of the zoom system in the embodiment of the present application;

[0037] Figure 4 Schematic diagram of another embodiment of the zoom system in the embodiment of the present application. Detailed implementation manners

[0038] The embodiment of the present invention provides a microscopic imaging system, which is used to match the laser in the band of 266 to 520 nm to realize the detection of semiconductor defects with high resolution and high detection rate.

[0039] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0040] The terms "first", "second", "third", "fourth", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. It should be understood that such used data can be interchanged under appropriate circumstances so that the embodiments described herein can be implemented in an order different from that shown or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0041] Based on the emergence of the 266 nm band laser in the prior art, in order to realize the detection of the detection object with high resolution and high speed, there is no imaging system matching this band in the prior art. In the embodiment of the present application, a microscopic imaging system is proposed to realize the detection of the detection object with high resolution and high speed.

[0042] For the convenience of understanding, the microscopic imaging system in the embodiment of the present application will be described below. Please refer to Figure 1 , an embodiment of the microscopic imaging system in the embodiment of the present application, includes:

[0043] A microscopic objective lens 10, a relay system 20, a diaphragm 30, and a zoom system 40 are coaxially arranged from the object side to the image side, where:

[0044] The working wavelength band of the microscopic objective lens 10 includes [266nm, 520nm], and the numerical aperture of the microscope objective lens is greater than 0.85, which is used to collimate and emit the reflected light and / or scattered light of the object to be measured.

[0045] The relay system 20 is used to adjust the exit pupil of the microscopic objective lens to the position of the diaphragm, so as to magnify or reduce the size of the beam collimated and emitted by the microscopic objective lens.

[0046] The diaphragm 30 is used to modulate the size of the exit pupil of the microscopic objective lens.

[0047] The zoom system 40 is used to adjust the focal length of the microscopic imaging system, so as to focus the collimated beam emitted by the relay system to the focal planes with different focal lengths for imaging.

[0048] As an optional embodiment, the focal length range of the microscopic objective lens 10 in the embodiment of the present application includes 8 - 20mm, the resolution of the microscopic objective lens is less than 0.3um, and the field of view is greater than 1.3mm.

[0049] Because the microscopic objective lens in the microscopic imaging system in the embodiment of the present application can image the wavelength of 266nm, the microscope objective lens in the embodiment of the present application can be matched with a high-power 266nm laser, and the frequency of the 266nm laser can reach 20MHz and the power is greater than 5W. Therefore, when the microscope objective lens in the embodiment of the present application is matched with a high-power 266nm laser, on the one hand, the test rate of semiconductors can be improved. And the numerical aperture of the microscope objective lens in the embodiment of the present application is greater than 0.85. Therefore, on the premise that the wavelength of the incident light is fixed, the minimum distance between two object points that the microscope objective lens can resolve is smaller, that is, on the other hand, the resolution of semiconductor defects of the microscope objective lens in the embodiment of the present application is also improved.

[0050] Based on Figure 1 The microscopic objective lens 10 in the embodiment, where the microscopic objective lens 10 can adopt an existing microscopic objective lens assembly on the market, or can adopt a dedicated microscope group structure. For example, a configuration scheme of a microscopic objective lens structure is provided here.

[0051] Specifically, the microscope objective lens in the embodiment of the present application consists of 8 groups and 17 lenses, and the optical power distribution of each component is as follows: Combination 1 has a negative optical power and consists of only 1 negative lens. The material of lens 1 is fused silica; Combination 2 has a negative optical power and consists of 4 lenses, namely 2 positive lenses 2 and 4, and 2 negative lenses 3 and 5; Combination 3 has a positive optical power and consists of 3 lenses, namely positive lens 6, negative lens 7, and positive lens 8; Combination 4 has a positive optical power and consists of a positive lens 9 and a negative lens 10. The negative lens is closer to the focal plane than the positive lens; Combination 5 has a positive optical power and consists of only 1 positive lens 11; Combination 6 has a positive optical power and consists of a positive lens 12 and a negative lens 13. The negative lens is closer to the image plane. Combination 7 consists of a positive lens 14 and a negative lens 15, and lens 15 is closer to the image plane; Combination 8 consists of 2 meniscus positive lenses, and the concave surfaces of lenses 16 and 17 face the focal plane.

[0052] Among them, Table 1 gives an embodiment of the focal length of each of the above 8 combinations:

[0053] Table 1:

[0054]

[0055]

[0056] Based on the lens groups in the above 8 combinations described in the table, the numerical aperture of the microscope objective lens can be greater than 0.85, and this microscope objective lens can operate in the [266nm, 520nm] band.

[0057] Based on Figure 1 the described microscopic imaging system, in order to achieve magnification of the detection object at different multiples, the embodiment of the present application designs a relay system 20 and a zoom system 30 that are matched with the microscope objective lens 10. Next, the relay system 20 in the embodiment of the present application will be described. Please refer to Figure 2 , an embodiment of the relay system 20 in the embodiment of the present application includes:

[0058] A first positive optical power lens group 201 and a second positive optical power lens group 202 are respectively arranged along the beam direction of the collimated beam emitted by the microscope objective lens. Among them, both the first positive optical power lens group 201 and the second positive optical power lens group 202 include multiple lenses with positive and negative optical powers cooperating with each other. For example, the number of lenses is at least 8, so as to adjust the exit pupil of the microscope objective lens to the aperture stop 30 to magnify or reduce the size of the beam collimated and emitted by the microscope objective lens.

[0059] As a possible embodiment, the first positive power lens group in the embodiments of the present application includes a first positive lens 2011, a second negative lens 2012, a third positive lens 2013, and a fourth negative lens 2014 arranged in sequence along the propagation direction of the light beam.

[0060] The second positive power lens group 202 includes a fifth positive lens 2021, a sixth positive lens 2022, a seventh negative lens 2023, and an eighth positive lens 2024 arranged in sequence along the propagation direction of the light beam.

[0061] Among them, the function of the first positive power lens group 201 is to make the aperture of the microscopic objective lens 10 match the aperture of the second positive power lens group 202, so that the light beam emitted by the microscopic objective lens 10 is collimated and the size of the collimated light beam is adjusted, such as magnifying or reducing the cross-section of the light beam.

[0062] Furthermore, when the first positive power lens group 201 and the second positive power lens group 202 cannot adjust the exit pupil of the microscopic objective lens 10 to the aperture stop 30 outside the relay system, the relay system 20 further includes a field lens 203 disposed near the focal plane of the first positive power lens group 201.

[0063] When the first positive power lens group 201 includes a first positive lens 2011, a second negative lens 2012, a third positive lens 2013, and a fourth negative lens 2014 arranged in sequence along the propagation direction of the light beam, and the second positive power lens group 202 includes a fifth positive lens 2021, a sixth positive lens 2022, a seventh negative lens 2023, and an eighth positive lens 2024 arranged in sequence along the propagation direction of the light beam, the field lens 203 includes a ninth positive lens 2031.

[0064] As an alternative embodiment, the distance between the relay system 20 and the microscopic objective lens 10 is greater than 150 mm to facilitate the insertion of a beam splitter for the intervention of the illumination system and / or the autofocus system. The distance between the last lens in the relay system 20 along the propagation direction of the light beam and the exit pupil of the microscopic objective lens is greater than 50 mm to facilitate the insertion of the aperture stop 30.

[0065] As an alternative embodiment, the magnification of the relay system in the embodiments of the present application ranges from 0.5 times to 1 time. Because when the magnification is greater than 1, the total length of the microscopic imaging system will be too long, resulting in the need to fold the optical path multiple times and increasing the complexity of alignment and adjustment. When the magnification is less than 0.5, the exit angle of the relay system 20 becomes larger, resulting in difficulties in correcting the off-axis aberrations of the zoom system 40.

[0066] Next, Figure 1 the zoom system 30 in the embodiment will be described in detail. Please refer to Figure 3 andFigure 4 , Figure 3 and Figure 4 are respectively schematic diagrams of two embodiments of the zoom system 40 in the embodiments of the present application.

[0067] Among them, the zoom system 40 includes a third positive focal length lens group 401 and a fourth negative focal length lens group 402. Among them, the magnification of the zoom system includes 40 times to 100 times, and the number of lens elements of the zoom system 40 includes 3 to 5 pieces.

[0068] As an optional embodiment, when the zoom system 40 includes a third positive focal length lens group 401 and a fourth negative focal length lens group 402 arranged in sequence along the light beam propagation direction, the zoom system 40 is a telephoto structure, the back working distance of the zoom system 40 is small, and the total length of the zoom system 40 is less than the focal length of the zoom system. When the zoom system 40 includes a fourth negative focal length lens group 402 and a third positive focal length lens group 401 arranged in sequence along the light beam propagation direction, the zoom system 40 is a retrofocus structure, the back working distance of the zoom system 40 is large, and the total length of the zoom system 40 is greater than the focal length of the zoom system. In actual situations, according to the needs of the mechanical layout, the structure of the zoom system 40 can be reasonably selected.

[0069] In the embodiments of the present application, the zoom system 40 adjusts the front and back order of the third positive focal length lens group 401 and the fourth negative focal length lens group 402 along the light beam propagation direction to change the back working distance and the total length of the zoom system, thereby improving the flexibility of the optical path mechanical layout.

[0070] It can be understood that whether the third positive focal length lens group 401 and the fourth negative focal length lens group 402 in the zoom system 40 are arranged in sequence as the third positive focal length lens group 401 and the fourth negative focal length lens group 402 along the light beam propagation direction, or are arranged in sequence as the fourth positive focal length lens group 402 and the fourth negative focal length lens group 401 along the light beam propagation direction, a magnification of 40 times to 100 times can be achieved, but only the back working distance and the total length of the zoom system 40 will be changed.

[0071] Next, the zoom system 40 will be further described. In actual situations, matching the magnification of the relay system 20, the zoom system 40 can include 3 or 5 lenses.

[0072] As an alternative embodiment, when the magnification of the relay system 20 is 1 and the zoom system 40 includes three lenses, namely the first lens 401, the second lens 402, and the third lens 403, if the magnification of the zoom system ranges from 40 times to 100 times, the zoom range of the second lens 402 ranges from 52 mm to 287 mm, the back working distance range of the third lens 403 (which can also be understood as the zoom distance of the third lens 403) ranges from 225 mm to 1403 mm, and the focal length range of the microscopic imaging system ranges from 600 mm to 1500 mm. For ease of understanding, Figure 3 A schematic diagram of a zoom system including three lenses is given.

[0073] As another alternative embodiment, when the magnification of the relay system is 0.5 and the zoom system 40 includes five lenses, namely the first lens 401, the second lens 402, the third lens 403, the fourth lens 404, and the fifth lens 405, if the magnification of the zoom system ranges from 40 times to 100 times, the zoom distance range of the fourth lens 404 ranges from 20 mm to 136 mm, the back working distance range of the fifth lens 405 ranges from 170 mm to 885 mm, and the focal length range of the microscopic imaging system ranges from 300 mm to 750 mm. For ease of understanding, Figure 4 A schematic diagram of a zoom system including five lenses is given.

[0074] In Figure 3 In the schematic diagram shown, three lenses are used as the zoom system, and the zoom range of the second lens 402 ranges from 52 mm to 287 mm, and the back working distance range of the third lens 403 ranges from 225 mm to 1403 mm. While in Figure 4 In the schematic diagram shown, five lenses are used as the zoom system, and the zoom distance range of the fourth lens 404 ranges from 20 mm to 136 mm, and the back working distance range of the fifth lens 405 (which can also be understood as the zoom distance of the fifth lens 405) ranges from 170 mm to 885 mm. That is, by changing the number of lenses in the zoom system 40 and the zoom distances of the lenses in the zoom system, the same magnification of the zoom system 40 can be achieved, thereby improving the flexibility of the structure of the zoom system 40.

[0075] It can be understood that the zoom distance mentioned here refers to the relative moving distance of a certain target lens relative to a reference point (such as the first lens of the zoom system) during the adjustment process of changing the imaging magnification of the system.

[0076] For the description of the lens parameters in the microscopic objective lens 10, the relay system 20, and the zoom system 40, the following is an example for illustration:

[0077] In the solution of Table 2, the magnification of the relay system is 1, the imaging focal length of the microscopic imaging system is 600 mm - 1500 mm, the back working distance is 237 mm - 1402 mm, and the total length of the microscopic imaging system is 1375 mm to 2319 mm.

[0078] Table 2:

[0079]

[0080]

[0081]

[0082] Surface Variable 40x 55x 80x 100x 59.00 Thickness 272.77 172.73 89.20 52.39 62.00 Thickness 237.33 528.64 1014.05 1402.15

[0083] In the above table, the microscopic objective lens includes each lens corresponding to surfaces 2 to 35, the relay system includes each lens corresponding to surfaces 37 to 54, and the zoom system includes each lens corresponding to surfaces 56 to 61.

[0084] It should be noted here that in the above table regarding the magnification, 40x - 100x represents that the magnification of the zoom system is 40 times to 100 times, and surface 59 represents the 59th surface of the lens combination in Table 1 (where each lens has 2 surfaces), and the thickness of surface 59 represents the thickness of the air layer after the 59th surface, that is, the distance between the 59th surface and the 60th surface, that is, the zoom distance of the lens including the 59th surface is 52.39 mm - 272.77 mm (corresponding to a magnification of 40 times to 100 times), and the thickness of the 62nd surface represents the back working distance of the zoom system, that is, the back working distance of the zoom system where the lens including the 62nd surface is located is 237.33 mm - 1402.15 mm.

[0085] In the solution of Table 3, the magnification of the relay system 20 is 0.5, the imaging focal length of the microscopic imaging system 40 is 300 mm - 750 mm, the back working distance is 170 mm - 879 mm, and the total length of the microscopic imaging system is 1133 mm - 1729 mm.

[0086] Table 3:

[0087]

[0088]

[0089]

[0090]

[0091] Surface Variable 40x 55x 80x 100x 63.00 Thickness 135.06 82.79 39.22 20.06 66.00 Thickness 170.14 348.79 646.40 884.33

[0092] In the above table, the micro-optical objective includes each lens corresponding to surfaces 2 to 35, the relay system includes each lens corresponding to surfaces 37 to 54, and the zoom system includes each lens corresponding to surfaces 56 to 65.

[0093] In the solution of Table 4, the magnification of the relay system 20 is 0.5, the imaging focal length of the micro-imaging system 40 is 300 mm - 750 mm, the back working distance is 170 mm - 1041 mm, and the total length of the micro-imaging system is 1227 - 1928 mm.

[0094] Table 4:

[0095]

[0096]

[0097]

[0098]

[0099] Surface Variable 40x 55x 80x 100x 62.00 Thickness 182.07 104.81 40.43 12.10 65.00 Thickness 170.42 388.06 750.90 1041.14

[0100] In the above table, the micro-optical objective includes each lens corresponding to surfaces 2 to 35, the relay system includes each lens corresponding to surfaces 37 to 55, and the zoom system includes each lens corresponding to surfaces 57 to 64. In Table 4 above, the magnification of the relay system is 0.5, the zoom system 40 includes 4 lenses, namely the first lens, the second lens, the third lens, and the fourth lens. If the magnification of the zoom system includes 40 times to 100 times, the zoom distance range of the third lens includes 12 mm to 183 mm, the back working distance range of the fourth lens includes 170 mm to 1041 mm, and the focal length range of the micro-imaging system includes 300 mm to 750 mm.

[0101] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A microscopic imaging system, characterized in that, Comprising: A microscope objective lens, a relay system, a diaphragm, and a zoom system that are coaxially arranged from the object side to the image side, where: The working wavelength band of the microscope objective lens includes [266nm, 520nm], and the numerical aperture of the microscope objective lens is greater than 0.85, which is used to collimate and emit the reflected light and / or scattered light of the object to be measured; The relay system is used to adjust the exit pupil of the microscope objective lens to the position of the diaphragm to magnify or reduce the size of the beam collimated and emitted by the microscope objective lens; The diaphragm is used to modulate the size of the exit pupil of the microscope objective lens; The zoom system is used to adjust the focal length of the microscopic imaging system to focus the collimated beam emitted by the relay system onto focal planes with different focal lengths for imaging.

2. The microscopic imaging system according to claim 1, wherein The relay system includes a first positive focal length lens group and a second positive focal length lens group arranged respectively along the direction of the collimated emitted beam. Among them, both the first positive focal length lens group and the second positive focal length lens group include a plurality of lenses with positive and negative focal lengths cooperating with each other.

3. The microscopic imaging system according to claim 2, wherein, If the first positive focal length lens group and the second positive focal length lens group cannot adjust the exit pupil of the microscope objective lens to the position of the diaphragm, the relay system further includes: A field lens disposed at the focal plane of the first positive focal length lens group.

4. The microscopic imaging system according to claim 3, characterized in that, The first positive focal length lens group includes a combination of a plurality of positive lenses and a plurality of negative lenses, and the second positive focal length lens group includes a combination of a plurality of positive lenses and a plurality of negative lenses, where: The first positive focal length lens group includes a first positive lens, a second negative lens, a third positive lens, and a fourth negative lens arranged in sequence along the propagation direction of the beam; The second positive focal length lens group includes a fifth positive lens, a sixth positive lens, a seventh negative lens, and an eighth positive lens arranged in sequence along the propagation direction of the beam; The field lens includes a ninth positive lens disposed near the focal plane of the first positive focal length lens group.

5. The microscopic imaging system according to claim 1, wherein The magnification of the relay system includes 0.5 times to 1 times.

6. The microscopic imaging system according to claim 1, wherein, The distance between the relay system and the microscope objective lens is greater than 150mm, and the distance between the last lens in the relay system along the beam propagation direction and the exit pupil of the microscope objective lens is greater than 50mm.

7. The microscopic imaging system according to claim 2, wherein The zoom system includes a third positive focal length lens group and a fourth negative focal length lens group.

8. The microscopic imaging system according to claim 7, wherein If the zoom system includes the third positive focal length lens group and the fourth negative focal length lens group arranged in sequence along the propagation direction of the beam, the zoom system is a telephoto structure; If the zoom system includes the fourth negative focal length lens group and the third positive focal length lens group arranged in sequence along the propagation direction of the beam, the zoom system is a retrofocus structure.

9. The microscopic imaging system according to claim 2, wherein, The magnification of the zoom system includes 40 times to 100 times, and the number of lens elements of the zoom system includes 3 to 5 pieces.

10. The microscopic imaging system according to claim 9, wherein, If the magnification of the relay system is 1 time and the zoom system includes a first lens, a second lens, and a third lens, where: If the magnification of the zoom system is from 40 times to 100 times, the zoom distance of the second lens includes 52 mm to 287 mm, the back working distance range of the third lens includes 225 mm to 1403 mm, and the focal length range of the microscopic imaging system includes 600 mm to 1500 mm.

11. The microscopic imaging system according to claim 9, characterized in that, If the magnification of the relay system is 0.5 times and the zoom system includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens, then: If the magnification of the zoom system is from 40 times to 100 times, the zoom distance range of the fourth lens includes 20 mm to 136 mm, the back working distance range of the fifth lens includes 170 mm to 885 mm, and the focal length range of the microscopic imaging system includes 300 mm to 750 mm.

12. The microscopic imaging system according to any one of claims 1 to 12, characterized in that, The resolution of the microscopic objective lens is less than 0.3 um and the field of view is greater than 1.3 mm.

13. The microscopic imaging system according to claim 1, characterized in that, The focal length range of the microscopic objective lens includes 8 mm to 20 mm.

Images