Collecting imaging module, optical device and semiconductor device

Abstract

This application discloses a collection imaging module, optical device, and semiconductor device to solve the problem of achieving low wavefront aberration while maintaining high magnification in the collection imaging module. The collection imaging module includes a fixed lens group, a first zoom lens group, and a second zoom lens group arranged sequentially along the object-image direction. The focal length of the fixed lens group satisfies: 40mm << 80mm; the focal length of the first zoom lens group is [missing value]; the focal length of the second zoom lens group is [missing value], and [missing value] and [missing value] satisfy: -1.3 < / < -0.605. Using the formula for the zoom ratio M of the collection imaging module: M = k / ( / )2 (where k is a constant related to the focal length and initial position of the fixed lens group), the zoom ratio range of the collection imaging module is derived to be 117.5x to 530x. The collection imaging module reduces wavefront aberration while maintaining a large zoom range, thus improving the imaging quality of the collection imaging module.

Description

Technical Field

[0001] This application relates to the field of optical imaging, and more particularly to imaging modules, optical devices, and semiconductor equipment. Background Technology

[0002] In semiconductor manufacturing, defect detection is a crucial step in process optimization and yield improvement. The image acquisition module plays a primary amplification role in the sample under test, and its imaging clarity is directly related to yield, making it a core device for defect detection. However, with the continuous improvement of semiconductor technology and process precision, the size of defects to be detected is becoming smaller and smaller. This requires the image acquisition module to have higher imaging clarity for small defects, corresponding to a larger numerical aperture (NA) of the module. Furthermore, in applications such as bright-field inspection, feature detection is performed using the differences in reflectivity of defects in different materials at different wavelengths; therefore, the image acquisition module also needs to meet the requirements of a wide spectrum. However, as the NA of the image acquisition module increases, aberrations also increase. The wider the designed spectrum, the more difficult the chromatic aberration correction becomes.

[0003] Existing imaging modules typically employ a multi-lens structure, making it difficult to balance zoom ratio and aberration correction. High zoom ratios are often accompanied by significant phase differences, resulting in poor image quality. Summary of the Invention

[0004] This application discloses a collection imaging module, an optical device, and a semiconductor device to solve the problem of achieving low wavefront aberration in a collection imaging module while maintaining high magnification.

[0005] In a first aspect, this application discloses an imaging module, comprising: a fixed lens group, a first zoom lens group, and a second zoom lens group arranged sequentially along the object-image direction, wherein the focal length of the fixed lens group is... Satisfying: 40mm <80mm; the focal length of the first zoom lens group is The focal length of the second zoom lens group is ,and and Satisfy: -1.3 < / <-0.605.

[0006] By sequentially arranging a fixed lens group, a first zoom lens group, and a second zoom lens group along the object-image direction, and ensuring that the focal length ratio of the first zoom lens group and the second zoom lens group satisfies -1.3 < / <-0.605 and the focal length of the fixed lens group meets the requirement of 40mm< <80mm, the zoom ratio M of the imaging module is calculated using the formula: M=k / ( / )2 (k is the focal length relative to the fixed lens group) The zoom ratio of the imaging module is derived to be 117.5 to 530 times, which ensures that the imaging module reduces wavefront aberration and improves imaging quality within a large zoom range.

[0007] In one possible implementation, the imaging module includes a first adjustment mechanism and a second adjustment mechanism. The first adjustment mechanism is connected to a first zoom lens group and is used to adjust the first zoom lens group to move along the optical axis. The second adjustment mechanism is connected to a second zoom lens group and is used to adjust the second zoom lens group to move along the optical axis.

[0008] By using independently set first and second adjustment mechanisms, the first zoom lens group and the second zoom lens group are driven to move along the optical axis respectively, which can precisely control the relative distance between the two groups, making the zoom process more flexible. Aberration compensation can be optimized for different focal lengths, improving the reliability and adjustment accuracy of zoom control.

[0009] In one possible implementation, the imaging module includes a third adjustment mechanism, which is connected to both the first zoom lens group and the second zoom lens group. The third adjustment mechanism is used to simultaneously adjust the first zoom lens group and the second zoom lens group to move towards each other or away from each other along the optical axis.

[0010] By using the same third adjustment mechanism to synchronously drive the first zoom lens group and the second zoom lens group to move towards or away from each other, the mechanical structure is simplified, the number of moving parts is reduced, and the synchronicity and consistency of zooming actions are improved.

[0011] In one possible implementation, the first zoom lens group has 7 lenses, and the material of each lens in the first zoom lens group is... and At least one of them.

[0012] The first zoom lens group uses 7 lenses. This 7-lens structure provides sufficient degrees of freedom to correct spherical aberration, coma, and chromatic aberration caused by wide zoom range. Meanwhile, the second zoom lens group also uses... and As a lens material, due to It has extremely low dispersion and high deep ultraviolet transmittance. It has good thermal and chemical stability. The combination of the two can effectively correct color difference over a wide range of wavelengths, while ensuring high transmittance in the ultraviolet to visible light bands.

[0013] In one possible implementation, the second zoom lens group has 5 lenses, and the material of the lenses in each second zoom lens group is... and At least one of them.

[0014] The second zoom lens group uses 5 lenses. This 5-lens structure makes the second zoom lens group lightweight, which is beneficial for rapid response adjustment and reduces light loss. Meanwhile, the first zoom lens group uses... and As a lens material, due to It has extremely low dispersion and high deep ultraviolet transmittance. It has good thermal and chemical stability. The combination of the two can effectively correct color difference over a wide range of wavelengths, while ensuring high transmittance in the ultraviolet to visible light bands.

[0015] In one possible implementation, the fixed lens assembly includes a beam splitter, a first fixed module, and a second fixed module, with the beam splitter disposed in the optical path between the first fixed module and the second fixed module.

[0016] By setting a beam splitter in the fixed lens group, the optical path is divided into transmission and reflection paths, which can realize illumination and imaging simultaneously. At the same time, the beam splitter is placed between the first fixed module and the second fixed module, without occupying additional space in the zoom part, which is conducive to the system's compactness.

[0017] In one possible implementation, the first fixed module has 7 lenses, and the material of each lens in the first fixed module is... and One of them.

[0018] The first fixed module includes 7 lenses, each lens using... or The material and 7-piece structure provide degrees of freedom for aberration correction, enabling pre-compensation for spherical aberration, field curvature, and astigmatism in a fixed optical path, and providing a good incident wavefront for subsequent zoom components. and The use of this technology can effectively suppress chromatic aberration accumulation and reduce wavefront aberration of the entire fixed lens group.

[0019] In one possible implementation, the first fixing module includes a first fixed lens, a second fixed lens, a third fixed lens, a fourth fixed lens, a fifth fixed lens, a sixth fixed lens, and a seventh fixed lens, wherein the first fixed lens and the sixth fixed lens are made of the same material. The second, third, fourth, fifth, and seventh fixed lenses are all made of the same material. .

[0020] By using the first fixed lens and the sixth fixed lens as The remaining fixed lenses are , Positioning the lens in the first and sixth positions can effectively correct the optical path difference between long and short wavelengths. Lenses provide stable refraction, which allows for the formation of beams with low dispersion and low aberrations over a wide wavelength range.

[0021] In one possible implementation, the focal length of the first fixed module Meets the requirement: 200mm <500mm.

[0022] Limiting the focal length of the first fixed module to the range of 200mm to 500mm allows it to match the focal length ratio of the first zoom group and the second zoom group, thus achieving the zoom ratio formula M=k / ( / ) 2 In this process, the constant k is at its optimal value, which stabilizes the zoom ratio of the entire system between 117.5x and 530x, ensuring that the fixed lens group has appropriate light-gathering ability and aberration compensation ability, thereby improving the imaging quality.

[0023] In one possible implementation, the second fixed module has 10 optical elements, and the lenses in each optical element of the second fixed module are made of [material not specified]. and One of them.

[0024] The second fixed module uses 10 optical elements (including lenses or mirrors), and all elements are selected from... or The material allows the second fixed module to correct most of the aberrations, while the zoom group only needs fine-tuning to maintain low wave aberrations, ensuring chromatic aberration correction and transmittance over a wide spectral range.

[0025] In one possible implementation, the focal length of the second fixed module Meets the requirement: 200mm <800mm.

[0026] By setting the focal length of the second fixed module Meets 200mm < <800mm, which allows it to match the focal length of the first zoom group, the second zoom group, and the first fixed module, thus achieving the zoom ratio formula M=k / ( / ) 2 In this system, the constant k is at its optimal value, ensuring that the second fixed module has appropriate light-gathering and aberration compensation capabilities, stabilizing the zoom ratio of the entire system between 117.5x and 530x, while avoiding the increase in wavelet aberration caused by the fixed lens group being too strong or too weak, thereby improving the imaging quality.

[0027] Secondly, this application provides an optical device including a collection imaging module as described in the above embodiments.

[0028] Since the optical device integrates the image collection module provided in the above embodiments, it can continuously zoom in the range of 117.5x to 530x, which can reduce the wavefront aberration of the optical device and improve the imaging quality of the optical device.

[0029] Thirdly, this application provides a semiconductor device, including the optical device provided in the above embodiments.

[0030] Since the semiconductor device uses the optical device provided in the above embodiments, and since this optical device has a large zoom ratio of 117.5 times to 530 times and low wave aberration, the semiconductor device can achieve high-precision imaging or energy focusing at different working distances, which helps to improve the resolution in the chip processing or inspection process and improve the processing yield or inspection accuracy. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the architecture of a semiconductor device according to an embodiment of this application;

[0033] Figure 2 This is a schematic diagram of the structure of the image collection module according to an embodiment of this application;

[0034] Figure 3 Schematic diagrams of the imaging module under three zoom states in Example 1 of this application;

[0035] Figures 4A to 4C for Figure 3 The simulation analysis diagrams of wavefront aberrations under three zoom states of the imaging module are collected.

[0036] Figure 5 Schematic diagrams of the imaging module under three zoom states in Example 2 of this application;

[0037] Figures 6A to 6C for Figure 5 The simulation analysis diagrams of wavefront aberrations under three zoom states of the imaging module are collected.

[0038] Figure 7This is a schematic diagram of the structure of a data collection and imaging module including a first adjustment mechanism and a second adjustment mechanism according to an embodiment of this application.

[0039] Figure 8 This is a schematic diagram of the structure of the image collection module including the third adjustment mechanism according to an embodiment of this application.

[0040] Explanation of reference numerals in the attached figures:

[0041] 1-Fixed lens assembly;

[0042] 11-Beam splitter; 12-First fixed module; 121-First fixed lens; 122-Second fixed lens; 123-Third fixed lens; 124-Fourth fixed lens; 125-Fifth fixed lens; 126-Sixth fixed lens; 127-Seventh fixed lens; 13-Second fixed module; 131-Manning mirror; 132-Aperture reflector; 133-First lens group; 134-Second lens group;

[0043] 2-First zoom lens group;

[0044] 3-Second zoom lens group;

[0045] 4-Sample to be tested;

[0046] 5-Image sensor;

[0047] 6-Light source;

[0048] 7-Image acquisition module; 71-First adjustment mechanism; 72-Second adjustment mechanism; 73-Third adjustment mechanism;

[0049] 8-Optical device; 81-Illumination module;

[0050] 9-Semiconductor equipment; 91-Support platform; 92-Image acquisition and processing module. Detailed Implementation

[0051] The embodiments of this application are described below with reference to the accompanying drawings.

[0052] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0053] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0054] It should be understood that the term "and / or" used in this document is merely a description of the same field in the related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0055] Depending on the context, the word "if" as used here can be interpreted as "when" or "when" or "in response to determination" or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination" or "in response to determination" or "when detection (of the stated condition or event)" or "in response to detection (of the stated condition or event)."

[0056] It should be understood that the terms "first," "second," etc., used in this application are for distinguishing purposes only and should not be construed as indicating or implying relative importance or order.

[0057] The phrase "within the range" used in this application, unless otherwise specified, includes both endpoints of the range by default. For example, in the range of 1 to 5, it includes the values ​​1 and 5.

[0058] In the description of this application, the terms “center,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0059] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation", "connection" and "joining" should be interpreted broadly, for example, they can be fixed connections, detachable connections, mating connections or integral connections; those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0060] This application provides a collection imaging module, an optical device, and a semiconductor device. The collection imaging module provided in this application offers the technical advantages of large zoom ratio and low wavefront aberration over a wide spectral range, making it particularly suitable for precision optical inspection fields requiring both large field-of-view defect search and high-resolution defect review. Specifically, this collection imaging module can be applied to defect detection equipment in semiconductor manufacturing and packaging. For example, as the core module of a bright-field or dark-field sample defect detection system, it provides high-resolution imaging of defects such as tiny particles, scratches, and bridging on the surface of the sample. Furthermore, this collection imaging module can also be applied to high-end industrial inspection fields and microscopic imaging systems. For example, it can be used in the inspection of flat panel displays to identify microscopic pixel defects and particulate contamination in the panel, and can also be applied to large-range continuous zoom microscopic imaging systems that require acquiring different spectral information for sample analysis.

[0061] In view of the technical problems mentioned in the background art, this application provides a collection imaging module, optical device and semiconductor device, and the following embodiments will be used to describe this application in detail.

[0062] Example 1

[0063] This application provides a semiconductor device, such as... Figure 1 As shown, the semiconductor device 9 may include the optical device 8 described in the following embodiments. The semiconductor device 9 may be a defect detection device for the sample 4 under test, used to detect defects on the surface of the sample 4 under test. In some examples, the semiconductor device 9 may be a bright-field defect detection device, which utilizes the difference in reflectivity of defects of different materials at different wavelengths to perform feature detection, and performs high-definition imaging of defects such as tiny particles, scratches, and bridging on the surface of the sample 4 under test.

[0064] In addition to the optical device 8, the semiconductor device 9 may also include a stage 91 and an image acquisition and processing module 92. The stage 91 is used to support and move the sample 4 to be tested, enabling translation and rotation of the sample 4 in the horizontal plane. The image acquisition and processing module 92 is used to acquire, process, and analyze the images acquired by the optical device 8, identifying and locating defects on the surface of the sample 4 (e.g., a wafer or mask). The image acquisition and processing module 92 includes an image sensor 5 and a processor; the image sensor 5 receives imaging signals from the image plane, and the processor processes the imaging signals.

[0065] Since the semiconductor device 9 employs the optical device 8 provided in the following embodiment, which has a large zoom ratio of 117.5 to 530 times and low wavelet aberration, the semiconductor device 9 can achieve high-precision imaging at different working distances, which helps to improve the resolution in the chip detection process and improve the detection accuracy.

[0066] Example 2

[0067] The optical device 8 provided in Embodiment 1 above includes the image collection module 7 described in any of the following examples. The image collection module 7 is an imaging optical assembly used for efficiently collecting light emitted from an object surface (such as the surface of the sample 4 under test), and capable of continuous zooming within a large zoom range of 117.5x to 530x while maintaining low wavefront aberrations. See also... Figure 1 In addition to the imaging collection module 7, the optical device 8 may also include an illumination module 81. The illumination module 81 is used to provide illumination light to the surface of the sample 4 to be tested, and it has a light source 6 inside. The light source 6 may be an ultraviolet light source, specifically a deep ultraviolet light source emitting wavelengths in the range of 190nm to 266nm, to provide the required illumination light for the illumination module 81.

[0068] Since the optical device 8 integrates the image collection module 7 provided in the following embodiments, it can continuously zoom in the range of 117.5x to 530x, which can reduce the wavefront aberration of the optical device 8 and thus improve the imaging quality of the optical device 8.

[0069] Example 3

[0070] like Figure 1 and Figure 2 As shown, the imaging module 7 according to an embodiment of this application may include a fixed lens group 1, a first zoom lens group 2, and a second zoom lens group 3 arranged sequentially along the object-image direction. The object-image direction refers to the direction from the sample 4 to the final imaging surface, and this direction is parallel to the optical axis. For example... Figure 2 As shown by the dashed arrows, light rays from the object plane pass sequentially through the fixed lens group 1, the first zoom lens group 2, and the second zoom lens group 3 before finally converging on the image plane. Here, the object plane can refer to the surface of the sample 4 under test, such as the front side of the sample 4. The image plane can refer to the photosensitive surface in the image sensor 5 used to receive light signals. The optical axis is the straight line passing through the geometric centers of the optical elements in the imaging module 7, and is the axis of symmetry of the lenses in the imaging module 7.

[0071] The fixed lens group 1 remains stationary during zooming. Its function is to provide the basic optical power for the entire system and to perform preliminary focusing and aberration pre-correction on the light reflected or scattered from the surface of the sample 4, providing a suitable incident beam for subsequent zoom lens groups. The overall focal length of the fixed lens group 1 is denoted as [missing information]. Satisfying 40mm < <80mm. In some examples, The focal length can be 45mm, 50mm, 55mm, 60mm, 65mm, 70mm, or 75mm, etc. Setting the focal length of the fixed lens group 1 within this range ensures that it has appropriate light-gathering ability, avoiding excessive aberrations due to too short a focal length or excessive system length and insufficient light-gathering ability due to too long a focal length. It also provides a good matching basis for aberration compensation of subsequent zoom lens groups. Optical power can be understood as the ability to converge or diverge light; positive optical power indicates convergence, and negative optical power indicates divergence.

[0072] The first zoom lens group 2 is located between the fixed lens group 1 and the second zoom lens group 3, and the second zoom lens group 3 is located between the first zoom lens group 2 and the image plane. The focal length of the first zoom lens group 2 is denoted as . The focal length of the second zoom lens group 3 is denoted as , and Satisfy -1.3 < / <-0.605. This relationship indicates that the optical powers of the first zoom lens group 2 and the second zoom lens group 3 have opposite signs, meaning one lens group has positive optical power and the other has negative optical power. By strictly controlling the focal length ratio of the two zoom lens groups within the above-mentioned range, while achieving super-large magnification changes, the aberrations generated by each lens group can compensate for each other, maintaining wavefront aberration at a low level across the entire focal length. It should be understood that wavefront aberration refers to the optical path difference between the actual wavefront and the ideal spherical wavefront, and is an important indicator for evaluating image quality. The smaller the wavefront aberration, the closer the system imaging is to the diffraction limit, and the higher the image sharpness.

[0073] For a zoom system consisting of a fixed lens group 1 and two zoom lens groups, the zoom ratio M of the imaging module 7 can be expressed by the zoom ratio formula M = k / ( / The expression is )², where k is the focal length relative to the fixed lens group 1. And constants related to the initial position. The initial position refers to the reference position of the first zoom lens group 2 and the second zoom lens group 3 along the optical axis relative to the fixed lens group 1 and the image plane. The selection of the initial position directly determines the initial air gap between each lens group. Therefore, in some examples, the 40mm < defined in this application <80mm, -1.3< / With a value < -0.605 and a reasonably set initial position, the zoom ratio M of the imaging module 7 can be configured to range from 117.5 times to 530 times, thus ensuring that the imaging module 7 reduces wavefront aberrations and improves imaging quality within a large zoom range. Figures 3 to 6C To verify the above technical effects, this application provides two specific design examples and performs optical simulations on them.

[0074] In such Figure 3 of (a) Figure 3 (b) and Figure 3 In the design example shown in (c), the focal length of the first zoom group The focal length of the second zoom group is 83.85mm. It is -72.13mm. / =-1.16. The NA of the imaging module 7 is 0.9, the design wavelength is 190nm~266nm, and the zoom range is 117.5X~530X. Figures 4A to 4C The root mean square wavefront error is less than 0.04 in all three scaling scenarios shown. , Where X is the wavelength of light. It should be understood that X represents the magnification factor; for example, 117.5X represents a magnification factor of 117.5. Figure 3 (a) and Figure 4A The structure of the collection imaging module 7 and the wavelet aberration simulation results are shown in a scene with a magnification of 117.5x. Figure 3 (b) and Figure 4B The structure and wavelet aberration simulation results of the collection imaging module 7 are shown in a 318x magnification scenario. Figure 3 (c) and Figure 4C The structure and wavelet aberration simulation results of the collection imaging module 7 are shown in a 530x magnification scenario. Figures 4A to 4C The curves represent the changes in root mean square wavefront error at different positions from the center to the edge of the imaging field of view for light of different wavelengths (e.g., ultraviolet light with wavelengths of 266nm, 260nm, 250nm, 240nm, 230nm, 220nm, 210nm, 200nm, and 190nm). Figures 4A to 4C In the wavefront aberration simulation analysis diagram, the horizontal axis represents the Y-direction field of view in millimeters, indicating the radial distance of the imaged point on the object surface (surface of sample 4) relative to the optical axis, i.e., different positions from the center to the edge in the imaging field of view; the vertical axis represents the root mean square wavefront error, indicating the root mean square value of the optical path difference between the actual wavefront and the ideal spherical wavefront. The smaller the root mean square wavefront error, the higher the imaging quality at that position in the field of view.

[0075] In such Figure 5 of (a) Figure 5 (b) and Figure 5 In the design example shown in (c), the focal length of the first zoom group The focal length of the second zoom group is 115.02mm. It is -172.78mm. / =-0.67. The NA of the imaging module 7 is 0.9, the design band is 190nm~266nm, and the zoom range is 117.5X~530X. Figures 6A to 6C The root mean square wavefront error is less than 0.04 in all three scaling scenarios shown. , λ is the wavelength of light. Figure 5 (a) and Figure 6A The structure of the collection imaging module 7 and the wavelet aberration simulation results are shown in a scene with a magnification of 117.5x. Figure 5 (b) and Figure 6B The structure and wavelet aberration simulation results of the collection imaging module 7 are shown in a 318x magnification scenario. Figure 5 (c) and Figure 6C The structure and wavelet aberration simulation results of the collection imaging module 7 are shown in a 530x magnification scenario. Figures 6A to 6C The curves represent the changes in root mean square wavefront error at different positions from the center to the edge of the imaging field of view for light of different wavelengths (e.g., ultraviolet light with wavelengths of 266nm, 260nm, 250nm, 240nm, 230nm, 220nm, 210nm, 200nm, and 190nm). Figures 6A to 6C In the wavefront aberration simulation analysis diagram, the horizontal axis represents the Y-direction field of view in millimeters, indicating the radial distance of the imaged point on the object surface (surface of sample 4) relative to the optical axis, i.e., different positions from the center to the edge in the imaging field of view; the vertical axis represents the root mean square wavefront error, indicating the root mean square value of the optical path difference between the actual wavefront and the ideal spherical wavefront. The smaller the root mean square wavefront error, the higher the imaging quality at that position in the field of view.

[0076] Simulation results show that, within the 40mm < specified in this application, <80mm, and -1.3< / Within the range of <-0.605, the imaging module 7 can achieve a zoom range of 117.5X to 530X, and the root mean square wavefront error under each zoom configuration is less than 0.04 wavelengths, proving that the focal length ratio range defined in this application can achieve a good balance between large zoom ratio and low wavefront aberration.

[0077] See some examples. Figure 7The imaging module 7 includes a first adjustment mechanism 71 and a second adjustment mechanism 72. The first adjustment mechanism 71 is connected to the first zoom lens group 2 and is used to adjust the movement of the first zoom lens group 2 along the optical axis. The second adjustment mechanism 72 is connected to the second zoom lens group 3 and is used to adjust the movement of the second zoom lens group 3 along the optical axis. The movement of the first zoom lens group 2 and the second zoom lens group 3 along the optical axis means that the two zoom lens groups perform a back-and-forth translational movement along an imaginary straight line of the optical axis, and the optical center of each lens group remains on the optical axis throughout the movement.

[0078] The first adjustment mechanism 71 and the second adjustment mechanism 72 can be mechanical transmission devices capable of linear motion. In some examples, the first adjustment mechanism 71 and the second adjustment mechanism 72 can each include a motor and a lead screw and nut assembly connected to the motor. The motor is rigidly connected to the lens barrel of the corresponding zoom lens group (the lens barrel of the first zoom lens group 2 or the lens barrel of the second zoom lens group 3) through the lead screw and nut assembly, thereby accurately converting the rotational motion of the motor into the linear motion of the corresponding lens group. To ensure motion accuracy, the corresponding lens barrel (the lens barrel of the first zoom lens group 2 or the lens barrel of the second zoom lens group 3) is guided by a linear guide rail, thereby restricting other degrees of freedom except for the optical axis direction, ensuring that the optical axis of the lens group coincides with the main optical axis of the system during zooming. In other examples, the first adjustment mechanism 71 and the second adjustment mechanism 72 can each be a linear motor. The output shaft of the linear motor is directly rigidly connected to the lens barrel of the corresponding lens group (the lens barrel of the first zoom lens group 2 or the lens barrel of the second zoom lens group 3), directly driving the corresponding lens group to perform linear motion along the optical axis direction.

[0079] During zooming, the first adjustment mechanism 71 drives the first zoom lens group 2 to move along the optical axis to the target position, and the second adjustment mechanism 72 drives the second zoom lens group 3 to move along the optical axis to the corresponding position. This changes the distance between the first zoom lens group 2 and the second zoom lens group 3, as well as the distance between each lens group and the fixed lens group 1, thereby adjusting the system's zoom ratio. Since the first adjustment mechanism 71 and the second adjustment mechanism 72 are independent, the moving speed and distance of the two zoom lens groups can be controlled separately, making the zooming process more flexible. By independently driving the first zoom lens group 2 and the second zoom lens group 3 along the optical axis, the relative distance between the two zoom lens groups can be precisely controlled. Aberration compensation can be optimized for different focal lengths, improving the reliability and adjustment accuracy of zoom control.

[0080] See some examples. Figure 8The imaging module 7 includes a third adjustment mechanism 73, which is connected to both the first zoom lens group 2 and the second zoom lens group 3. This third adjustment mechanism 73 is used to simultaneously adjust the movement of the first zoom lens group 2 and the second zoom lens group 3 towards each other or away from each other along the optical axis. Moving towards each other means that the first zoom lens group 2 and the second zoom lens group 3 move closer to each other along the optical axis, reducing the distance between them. Moving away from each other means that the first zoom lens group 2 and the second zoom lens group 3 move further away from each other along the optical axis, increasing the distance between them. Specifically, when zooming from a low magnification (e.g., 117.5X) to a high magnification (e.g., 530X), the third adjustment mechanism 73 drives the two zoom lens groups to move towards each other, reducing the air gap between them, thereby increasing the zoom ratio of the system; conversely, when zooming from a high magnification to a low magnification, it drives them to move away from each other, increasing the air gap to decrease the zoom ratio.

[0081] The third adjustment mechanism 73 can employ a mechanical transmission device capable of simultaneously driving two moving parts to perform opposite linear movements. In some examples, the third adjustment mechanism 73 may include a bidirectional lead screw with threads of opposite directions at both ends. The first zoom lens group 2 engages with one end of the bidirectional lead screw via a first nut, and the second zoom lens group 3 engages with the other end of the bidirectional lead screw via a second nut. When the bidirectional lead screw rotates, the first nut and the second nut move in opposite directions, thereby driving the first zoom lens group 2 and the second zoom lens group 3 to move towards or away from each other. In other examples, the third adjustment mechanism 73 may include a gear and rack mechanism, with one gear meshing with two racks simultaneously. The two racks are fixedly connected to the first zoom lens group 2 and the second zoom lens group 3, respectively. When the gear rotates, the two racks move in opposite directions, driving the two zoom lens groups to move towards or away from each other.

[0082] During zooming, when an increase in zoom ratio is needed, the third adjustment mechanism 73 drives the first zoom lens group 2 and the second zoom lens group 3 to move towards each other, reducing the distance between them; when a decrease in zoom ratio is needed, the third adjustment mechanism 73 drives the two zoom lens groups to move away from each other, increasing the distance between them. Since the first zoom lens group 2 and the second zoom lens group 3 are synchronously driven by the same third adjustment mechanism 73, the moving speed and moving distance of the two lens groups maintain a fixed proportional relationship, resulting in higher synchronicity and consistency of the zooming action. Using the same third adjustment mechanism 73 to synchronously drive the first zoom lens group 2 and the second zoom lens group 3 to move towards or away from each other simplifies the mechanical structure, reduces the number of moving parts, lowers system complexity and manufacturing costs, while simultaneously improving the synchronicity and consistency of the zooming action.

[0083] In some examples, the first zoom lens group 2 has 7 lenses. It should be understood that the number of lenses in each lens group shown in the accompanying drawings is only illustrative and does not represent the actual number of lenses in each lens group. The specific number of lenses in each lens group is subject to the textual description and parameter table in the specification. The 7-lens structure provides sufficient design freedom for the first zoom lens group 2, allowing for the correction of spherical aberration, coma, astigmatism, and chromatic aberration caused by large-range zoom by reasonably configuring the radius of curvature, thickness, and spacing of each lens. In some examples, the 7 lenses may include a combination of biconvex lenses, biconcave lenses, and meniscus lenses, with positive power lenses and negative power lenses alternating to achieve mutual compensation of aberrations. As shown in Tables 1 and 2 below, this application provides specific examples of each lens in the first zoom lens group 2; of course, the number and type of each lens are not limited to these. The material of each lens in the first zoom lens group 2 can be... and At least one of them. It refers to calcium fluoride, which has extremely low dispersion and high deep ultraviolet transmittance, and has excellent optical properties in the 190nm to 266nm wavelength range. This refers to fused silica, which possesses excellent thermal and chemical stability, maintaining stable optical performance over a wide temperature range and under various environmental conditions. The surfaces of each lens can be coated with an anti-reflection film as needed to reduce light reflection loss and improve light energy utilization. As shown in Tables 1 and 2 below, this application provides specific examples of material usage; however, the materials used for each lens are not limited to these examples.

[0084] The first zoom lens group 2 adopts a 7-lens structure and selects... and / or As lens materials, the combination of the two can effectively correct chromatic aberration over a wide range of wavelengths while ensuring high transmittance in the ultraviolet to visible light bands, thereby improving the imaging quality of the imaging module 7 over a large zoom range.

[0085] In some examples, the second zoom lens group 3 has five lenses. Compared to the seven-element structure of the first zoom lens group 2, the five-element structure makes the second zoom lens group 3 lighter, with less overall mass and lower inertia, which is beneficial for achieving rapid response adjustment during zooming. At the same time, the fewer lenses also reduce the reflection and absorption of light on the lens surface, reducing light energy loss. In some examples, the five lenses may include a combination of biconvex lenses, biconcave lenses, and meniscus lenses. As shown in Tables 1 and 2 below, this application provides specific examples of each lens in the second zoom lens group 3; of course, the number and type of each lens are not limited to these examples.

[0086] The materials of the lenses in the second zoom lens group 3 can be... and At least one of them. As mentioned above, It has extremely low dispersion and high deep ultraviolet transmittance. It exhibits good thermal and chemical stability. In some examples, the second zoom lens group 3 may include two elements. Lens and 3 pieces Lens. In other examples, the second zoom lens group 3 may include 3 lenses. Lens and 2 pieces Lenses. The surface of each lens can be coated with an anti-reflective coating as needed to improve light energy utilization.

[0087] The second zoom lens group 3 uses a 5-element lens structure and selects... and / or As lens materials, the combination of the two can effectively correct chromatic aberration over a wide range of wavelengths while ensuring high transmittance in the ultraviolet to visible light bands.

[0088] like Figure 2 As shown, in some examples, the fixed lens group 1 includes a beam splitter 11, a first fixed module 12, and a second fixed module 13. The beam splitter 11 is disposed in the optical path between the first fixed module 12 and the second fixed module 13. The beam splitter 11 is used to split the optical path into transmission and reflection paths, which can simultaneously realize illumination and imaging functions. In some embodiments, the beam splitter 11 can be a semi-reflective mirror with a semi-transparent coating on its surface. The ratio of the transmittance to the reflectance of the semi-reflective coating is 50:50, and the operating wavelength covers 190nm to 266nm to achieve a balanced energy distribution between illumination light and imaging light. In some embodiments, the beam splitter 11 is a non-polarized beam splitter, that is, it has the same transmittance and reflectance for s-polarized light and p-polarized light, thereby avoiding the introduction of additional polarization aberrations.

[0089] The first fixed module 12 can be located between the beam splitter 11 and the image plane, and the second fixed module 13 can be located between the beam splitter 11 and the object plane. In bright-field detection applications, the illumination light originates from the light source 6, is transmitted through the beam splitter 11, and enters the second fixed module 13, where it is focused onto the object plane (e.g., the surface of the sample 4 under test). Defects on the object plane generate scattered signal light after illumination. This signal light is collected by the second fixed module 13 and reaches the beam splitter 11. After being reflected by the beam splitter 11, it enters the first fixed module 12, and then converges onto the image plane after passing through the first zoom lens group 2 and the second zoom lens group 3. The beam splitter 11 is placed between the first fixed module 12 and the second fixed module 13, without occupying additional space in the zoom section, which is beneficial for system compactness. At the same time, the beam splitter 11 separates the illumination light path and the imaging light path, and allows the illumination light path and the imaging light path to share the second fixed module 13, simplifying the structure. It should be understood that the illumination optical path refers to the path of illumination light propagating from the light source 6 to the object surface. The imaging optical path refers to the path of signal light generated on the object surface propagating to the image surface.

[0090] In some examples, the first fixed module 12 can have seven lenses. This seven-lens structure provides sufficient degrees of freedom for aberration correction, pre-compensating for spherical aberration, field curvature, and astigmatism in the fixed optical path, and providing a good incident wavefront for subsequent zoom lens groups. The material of each lens in the first fixed module 12 is... and One type, where each lens can be made from a single material, is... or . It has extremely low dispersion, which can effectively correct color differences. It exhibits good thermal and chemical stability, providing stable refractive properties. (Among the 7 lenses) Lens and The appropriate lens arrangement provides a good incident wavefront for the subsequent zoom lens group, while effectively suppressing chromatic aberration accumulation and reducing wavefront aberration of the entire fixed lens group 1. As shown in Tables 1 and 2 below, this application provides specific parameter examples for each lens in the first fixed module 12. Those skilled in the art can adjust each lens according to actual design requirements.

[0091] In some examples, such as Figure 3 (c) The first fixed module 12 may include a first fixed lens 121, a second fixed lens 122, a third fixed lens 123, a fourth fixed lens 124, a fifth fixed lens 125, a sixth fixed lens 126, and a seventh fixed lens 127 arranged sequentially along the optical axis. The first fixed lens 121 and the sixth fixed lens 126 may both be made of the same material. The second fixed lens 122, the third fixed lens 123, the fourth fixed lens 124, the fifth fixed lens 125, and the seventh fixed lens 127 are all made of the same material. .

[0092] It has extremely low dispersion characteristics, The lens of the material is placed in the first and sixth positions, which can correct the optical path difference between long and short wavelengths at different stages of the optical path, so that light of different wavelengths maintains a small chromatic difference after passing through the first fixed module 12. The lens, positioned in the center, provides stable refractive characteristics while also correcting for spherical aberration and field curvature. Through this material distribution, the first fixed module 12 can generate a low-dispersion, low-aberration beam over a wide wavelength range, providing a high-quality incident wavefront for subsequent zoom lens groups.

[0093] In some examples, the focal length of the first fixed module 12 Meets 200mm < <500mm. Focal length of the first fixed module 12 This affects its ability to converge light and its compatibility with subsequent zoom lens groups. By limiting the focal length to a range of 200mm to 500mm, the focal length ratio of the first fixed module 12 can be matched with that of the first zoom lens group 2 and the second zoom lens group 3, thereby achieving the zoom ratio formula M=k / ( / In the formula )², by optimizing the constant k, the zoom ratio of the entire system is stabilized between 117.5x and 530x, thereby improving the imaging quality. For example, It can be 250mm, 300mm, 350mm, 400mm or 450mm, etc.

[0094] In some examples, such as Figure 2 As shown, the second fixed module 13 has 10 optical elements, including 8 lenses, 1 Manningen mirror 131, and 1 aperture reflector 132. The Manningen mirror 131 is a catadioptric element with an anti-reflective coating in its central region near the object surface and a high-reflectivity coating in its peripheral region to achieve catadioptric reflection, correcting aberrations while compressing the system volume. The aperture size of the central through-hole of the aperture reflector 132 matches the light-transmitting area of ​​the Manningen mirror 131 to ensure that unobstructed light can pass through smoothly. A first lens group 133 can be arranged between the Manningen mirror 131 and the aperture reflector 132, and a second lens group 134 can be arranged on the side of the aperture reflector 132 opposite to the Manningen mirror 131. The first lens group 133 can have 1 lens, and the second lens group 134 can have 7 lenses. The specific number of lenses in the first lens group 133 and the second lens group 134 can be adjusted adaptively.

[0095] For example, the transmission process of light in the second fixed module 13 may include two parts: a first optical path before reaching the sample 4 under test and a second optical path emitted from the sample 4 under test. In the first optical path, the illumination light is transmitted through the beam splitter 11 and enters the second fixed module 13. After passing through the second lens group 134, it passes through the central through-hole of the aperture mirror 132, then through the first lens group 133, and enters the lens body of the Manning mirror 131 through the anti-reflection coating surface on the side away from the object surface. After reaching the peripheral high-reflection coating area on the side of the Manning mirror 131 near the object surface, it is reflected. The reflected light returns through the lens body of the Manning mirror 131, passes through the first lens group 133, and reaches the reflecting surface of the aperture mirror 132 and is reflected again. After the second reflection, the light passes through the first lens group 133, enters the lens body of the Manning mirror 131 again through the anti-reflection coating surface on the side away from the object surface, and finally is transmitted out from the central anti-reflection coating area on the side of the Manning mirror 131 near the object surface, and is focused onto the surface of the sample 4 to be tested.

[0096] In the second optical path, the defects on the surface of the sample 4 under test are illuminated, generating scattered signal light. The signal light enters the lens body of the Manning lens 131 from the central antireflection coating area on the side closer to the object surface. After exiting the antireflection coating surface on the side of the Manning lens 131 away from the object surface, it passes through the first lens group 133 and is reflected after reaching the reflecting surface of the aperture mirror 132. The reflected light passes through the first lens group 133, enters the lens body of the Manning lens 131 on the side away from the object surface, and is reflected again after reaching the peripheral high reflectivity coating area on the side of the Manning lens 131 closer to the object surface. After the second reflection, the light passes through the lens body of the Manning lens 131 and the first lens group 133, passes through the central through hole of the aperture mirror 132, passes through the second lens group 134 in sequence, and finally reaches the beam splitter 11. After being reflected by the beam splitter 11, it enters the first fixed module 12.

[0097] It should be noted that the substrate materials of the Manning mirror 131 and the aperture reflector 132 in the second fixed module 13 are also selected from [the following]. and One of them is to ensure that the entire second fixed module has uniform thermal stability, optical transmittance and reflectance in the deep ultraviolet band.

[0098] The lens in the optical element of the second fixed module 13 is made of the following material: and One type is where each lens is made of a single material. It has extremely low dispersion and high deep ultraviolet transmittance. It possesses excellent thermal and chemical stability, and their proper combination can effectively correct chromatic aberration over a wide spectral range. The second fixed module 13 employs 10 optical elements, allowing the zoom lens group to maintain low spectral aberrations with only minor adjustments after the second fixed module 13 has undertaken the correction of most aberrations, thus ensuring chromatic aberration correction and transmittance over a wide spectral range. As shown in Tables 1 and 2 below, this application provides specific examples of each optical element in the second fixed module 13. Those skilled in the art can adjust each optical element according to actual design requirements.

[0099] In some examples, the focal length of the second fixed module 13 Meets 200mm < <800mm. Focal length of the second fixed module 13 This affects its ability to focus object-side light and its compatibility with other lens groups. By limiting the focal length to a range of 200mm to 800mm, the second fixed module 13 can be matched with the focal lengths of the first zoom lens group 2, the second zoom lens group 3, and the first fixed module 12, thereby achieving the zoom ratio formula M=k / ( / In )², the constant k is at its optimal value. In some examples, The focal length can be 300mm, 400mm, 500mm, 600mm, or 700mm, etc. By limiting the focal length of the second fixed module 13 to the range of 200mm to 800mm, it is ensured that the second fixed module 13 has appropriate light-gathering ability and aberration compensation ability, so that the zoom ratio of the entire system is stabilized between 117.5x and 530x. At the same time, it avoids the increase of wavelet aberration caused by the fixed lens group 1 being too strong or too weak, thereby improving the image quality.

[0100] As shown in Tables 1 and 2 below, this application provides detailed optical parameters for two design examples. Table 1 corresponds to the optical parameters of Design Example 1, and Table 2 corresponds to the optical parameters of Design Example 2. The surface number indicates the number of each optical surface that the light ray passes through sequentially from the object surface. Each lens has two optical surfaces (incident surface and exit surface), therefore one lens corresponds to two consecutive surface numbers. Surface number 0 is the object surface. The radius of curvature indicates the degree of curvature of the optical surface, in millimeters. A positive value indicates that the center of curvature is located on the image side of the surface, and a negative value indicates that the center of curvature is located on the object side of the surface. Infinity indicates that the surface is planar. Thickness indicates the distance from this surface to the next surface along the optical axis, in millimeters. A positive value indicates that the light ray propagates in the forward direction, and a negative value indicates that the light ray propagates in the reverse direction after reflection. The values ​​in the tables are expressed in scientific notation, where E represents a power to the base 10, for example, 1.80E+01 represents 18.0 mm. For the variable spacing between zoom lens groups, the table uses Z1, Z2, and Z3 to indicate the spacing values ​​for the three zoom configurations, corresponding to magnifications of 117.5X, 318X, and 530X. For example, Z1 represents the spacing at 117.5x magnification, Z2 represents the spacing at 318x magnification, and Z3 represents the spacing at 530x magnification. The material refers to the medium following this surface and preceding the next surface. Indicates calcium fluoride. The symbol represents fused silica, Mirror represents the reflecting surface, and blank represents air. It should be understood that those skilled in the art can determine the specific type of each lens based on its radius of curvature, and this application will not list them all.

[0101] Table 1

[0102]

[0103]

[0104] Table 2

[0105]

[0106]

[0107] The above-described preferred embodiments have further illustrated the purpose, technical solutions, and advantages of this application. It should be understood that the above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An imaging collection module, characterized in that, include: Along the image direction, a fixed lens group, a first zoom lens group, and a second zoom lens group are arranged sequentially. The focal length of the fixed lens group Satisfying: 40mm <80mm; The focal length of the first zoom lens group is The focal length of the second zoom lens group is ,and and Satisfy: -1.3 < / <-0.

605.

2. The image collection module according to claim 1, characterized in that, The image collection module includes a first adjustment mechanism and a second adjustment mechanism. The first adjustment mechanism is connected to the first zoom lens group and is used to adjust the first zoom lens group to move along the optical axis. The second adjustment mechanism is connected to the second zoom lens group and is used to adjust the second zoom lens group to move along the optical axis.

3. The image collection module according to claim 1, characterized in that, The imaging module includes a third adjustment mechanism, which is connected to the first zoom lens group and the second zoom lens group. The third adjustment mechanism is used to simultaneously adjust the first zoom lens group and the second zoom lens group to move towards each other or away from each other along the optical axis.

4. The image collection module according to any one of claims 1 to 3, characterized in that, The first zoom lens group has 7 lenses, and the material of each lens in the first zoom lens group is... and At least one of them.

5. The image collection module according to any one of claims 1 to 4, characterized in that, The second zoom lens group has 5 lenses, and the material of each lens in the second zoom lens group is... and At least one of them.

6. The image collection module according to any one of claims 1 to 5, characterized in that, The fixed mirror assembly includes a beam splitter, a first fixed module, and a second fixed module, with the beam splitter disposed in the optical path between the first fixed module and the second fixed module.

7. The image collection module according to claim 6, characterized in that, The first fixed module has 7 lenses, and the material of each lens in the first fixed module is... and One of them.

8. The image collection module according to claim 7, characterized in that, The first fixed module includes a first fixed lens, a second fixed lens, a third fixed lens, a fourth fixed lens, a fifth fixed lens, a sixth fixed lens, and a seventh fixed lens. The first fixed lens and the sixth fixed lens are both made of the same material. The second fixed lens, the third fixed lens, the fourth fixed lens, the fifth fixed lens, and the seventh fixed lens are all made of the same material. .

9. The image collection module according to any one of claims 6 to 8, characterized in that, The focal length of the first fixed module Meets the requirement: 200mm <500mm.

10. The image collection module according to any one of claims 6 to 9, characterized in that, The second fixed module has 10 optical elements, and the lens material in each optical element of the second fixed module is... and One of them.

11. The image collection module according to any one of claims 6 to 10, characterized in that, The focal length of the second fixed module Meets the requirement: 200mm <800mm.

12. An optical device, characterized in that, include: The image collection module according to any one of claims 1 to 11.

13. A semiconductor device, characterized in that, Includes the optical device as described in claim 12.

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