A pose adjustment system for a collimating objective and a wavefront analyzer

Abstract

The application provides a pose adjustment system for a collimator and a wavefront analyzer, wherein the pose adjustment system comprises a laser, a light path transmission assembly and a light path correction plate, the light path correction plate is provided with a light transmission hole, the laser is arranged at a first position of an optical platform, the wavefront analyzer is arranged at a second position of the optical platform, and the light path correction plate is arranged at a third position between the light path transmission assembly and the wavefront analyzer, wherein a laser beam emitted by the laser is transmitted through the light path transmission assembly, projected onto a target surface of the wavefront analyzer through the light transmission hole of the light path correction plate and the collimator, and a light spot is formed on the target surface, and according to the light spot position of the light spot on the target surface, the installation angle of the collimator is adjusted so that the optical axis of the collimator coincides with the optical axis of the wavefront analyzer. The effect that the collimator installed on the wavefront analyzer is accurately adjusted based on the received light rays of the collimator is achieved.

Description

Technical Field

[0001] The present application relates to the field of optical correction technology, and in particular to a posture adjustment system for a collimating objective lens and a wavefront analyzer. Background Art

[0002] At present, with the continuous reduction of chip feature size in the integrated circuit industry, the performance requirements for exposure systems are constantly increasing. The aberration control of the projection objective is directly related to the quality of the exposure pattern linewidth. Therefore, it is necessary to perform offline or online detection of the main performance parameters of the projection objective to ensure that they meet the equipment process requirements. The main detection parameters include wave aberration, distortion, magnification, astigmatism, IPD (Integrated Product Development) and NA (Numerical Aperture of the optical system) consistency.

[0003] The measurement sensor uses a Hartmann sensor. After light is refracted and focused by the objective lens, it is collimated by a collimating lens. Then, it passes through the Hartmann sensor's microlens array and is focused onto the CCD (charge-coupled device) target surface. To achieve measurement accuracy, the relative position of the collimating lens and wavefront analyzer must be calibrated to eliminate systematic errors caused by collimating lens tilt.

[0004] When calibrating the installation position of the collimating objective lens, on the one hand, the wavefront aberration of the off-axis field of view fluctuates greatly, which may cause measurement sensitivity errors. On the other hand, when docking with the image point of the object to be measured, the posture of the wavefront analyzer is difficult to accurately locate the calibrated collimating objective lens image point position. When the telecentricity of the objective lens to be measured is large, it may also lead to the situation where the image point light cone cannot be fully taken over. Summary of the Invention

[0005] In view of this, the purpose of the present application is to provide a posture adjustment system for a collimating objective lens and a wavefront analyzer, which can ensure that the optical axis of the light received by the collimating objective lens is perpendicular to the target surface of the wavefront analyzer by adjusting the position of the laser, the optical path transmission component and the optical path correction plate, so as to solve the problem in the prior art that when correcting the installation position of the collimating objective lens, on the one hand, the wave aberration of the off-axis field of view fluctuates greatly, which may cause measurement sensitivity errors; on the other hand, when docking with the image point of the object to be measured, the posture of the wavefront analyzer is difficult to accurately locate to the calibrated image point position of the collimating objective lens. When the telecentricity of the objective lens to be measured is large, it will also bring about the problem of not being able to fully receive the image point light cone, so as to achieve the effect of accurately adjusting the collimating objective lens installed on the wavefront analyzer based on the light received by the collimating objective lens.

[0006] An embodiment of the present application provides a posture adjustment system for a collimating objective lens and a wavefront analyzer, the posture adjustment system includes a laser, an optical path transmission component and an optical path correction plate, the optical path correction plate is provided with a light-transmitting hole, wherein the laser is arranged at a first position of an optical platform, the wavefront analyzer is arranged at a second position of the optical platform, the optical path transmission component is arranged between the laser and the wavefront analyzer, the optical path correction plate is arranged at a third position between the optical path transmission component and the wavefront analyzer, the collimating objective lens is adjustably installed on a side of the wavefront analyzer close to the optical path correction plate, the position of the light-transmitting hole on the optical path correction plate is the position of the focus of the collimating objective lens, wherein the laser beam emitted by the laser is transmitted through the optical path transmission component and is projected onto the target surface of the wavefront analyzer via the light-transmitting hole on the optical path correction plate and the collimating objective lens to form a light spot on the target surface, and the installation angle of the collimating objective lens is adjusted according to the position of the light spot on the target surface so that the optical axis of the collimating objective lens coincides with the optical axis of the wavefront analyzer.

[0007] Optionally, the optical path transmission component includes a laser beam expander, an Abbe prism and a laser focusing mirror, wherein the laser beam expander is arranged at the fourth position of the optical platform, and the laser beam emitted by the laser is expanded by the laser beam expander and projected onto the target surface of the wavefront analyzer without the collimating objective lens, forming a light spot on the target surface, and according to the position of the light spot on the target surface, the installation angle of the laser beam expander is adjusted so that the optical axis of the laser beam expander coincides with the optical axis of the wavefront analyzer, wherein the Abbe prism is arranged at the fifth position of the optical platform, and the fifth position is located between the fourth position and the wavefront analyzer and close to the fourth position, and the laser beam expanded by the adjusted laser beam expander is emitted to the incident plane of the Abbe prism. The laser beam emitted from the exit plane of the Abbe prism after being reflected by the Abbe prism is projected onto the target surface of the wavefront analyzer without the collimating objective lens installed to form a light spot. According to the position of the light spot on the target surface, the installation angle of the Abbe prism is adjusted so that the optical axis of the Abbe prism coincides with the optical axis of the wavefront analyzer. The laser focusing lens is arranged at the sixth position of the optical platform, and the sixth position is between the fifth position and the wavefront analyzer. The laser beam emitted from the exit plane of the adjusted Abbe prism is projected onto the target surface of the wavefront analyzer without the collimating objective lens via the laser focusing lens. The installation angle of the laser focusing lens is adjusted so that the optical axis of the laser focusing lens coincides with the optical axis of the laser beam after being reflected by the Abbe prism.

[0008] Optionally, the posture adjustment system also includes a flat crystal and an autocollimator, the flat crystal is arranged on the first side surface of the laser focusing plate facing the collimating autocollimator, the laser focusing plate is located above the laser focusing mirror, the second side surface of the laser focusing plate is fixedly connected to the edge of the laser focusing mirror, the setting height of the flat crystal is higher than the height of the upper edge of the wavefront analyzer, the autocollimator is arranged at the seventh position of the optical platform, the seventh position is located on the other side of the wavefront analyzer away from the laser, the setting height of the autocollimator arranged at the seventh position is higher than the height of the upper edge of the wavefront analyzer, and is used to detect the installation angle of any plane in front of the wavefront analyzer, wherein the test light emitted by the autocollimator is irradiated onto the flat crystal, and the feedback light reflected back by the flat crystal is received, and the installation angle of the laser focusing plate is adjusted to make the test light coincide with the feedback light, so that the optical axis of the laser focusing mirror on the laser focusing plate coincides with the optical axis of the laser beam reflected by the Abbe prism.

[0009] Optionally, the posture adjustment system also includes an autocollimator, which is calibrated in the following manner: after the laser focusing mirror is not arranged on the optical platform and the optical axis of the Abbe prism is adjusted to coincide with the optical axis of the wavefront analyzer, the test light emitted by the autocollimator is irradiated onto the exit plane of the Abbe prism, and the feedback light reflected back through the exit plane of the Abbe prism is received, and the installation angle of the autocollimator on the optical platform is adjusted so that the test light of the autocollimator coincides with the feedback light.

[0010] Optionally, the posture adjustment system also includes an autocollimator, and the installation angle of the optical path correction plate is corrected in the following manner: the test light emitted by the autocollimator is irradiated onto the optical path correction plate, and the feedback light reflected back by the optical path correction plate is received, and the installation angle of the optical path correction plate is adjusted so that the test light coincides with the feedback light.

[0011] Optionally, the posture adjustment system also includes a micro-motion device, the optical path correction plate is installed on the micro-motion device, and the micro-motion device is arranged at a third position on the optical platform. A plurality of light-transmitting holes are provided on the optical path correction plate, and each light-transmitting hole has a different size. The laser focusing mirror is removed, and the micro-motion device is controlled to move to drive the optical path correction plate to move, so that each light-transmitting hole on the optical path correction plate is moved in order from large to small to the position where the focus of the collimating objective lens is located. During each movement, the installation angle of the optical path correction plate is adjusted so that the laser beam emitted through the exit plane of the Abbe prism forms a light spot on the target surface of the wavefront analyzer through the light-transmitting hole on the optical path correction plate at the center of the target surface.

[0012] Optionally, the laser focusing mirror is rearranged at the sixth position of the optical platform, and the installation angle of the laser focusing mirror is adjusted so that the optical axis of the laser focusing mirror coincides with the optical axis of the laser beam reflected by the Abbe prism.

[0013] Optionally, the posture adjustment system also includes a lens mount and an adjusting screw, the collimating objective lens is mounted on the wavefront analyzer through the lens mount, and the adjusting screw is used to adjust the installation angle of the collimating objective lens relative to the wavefront analyzer so that the optical axis of the collimating objective lens coincides with the optical axis of the wavefront analyzer.

[0014] Optionally, the adjusting screw is adjusted according to the offset between the position of the light spot on the target surface and the target surface center of the wavefront analyzer so that the optical axis of the collimating objective lens coincides with the optical axis of the wavefront analyzer.

[0015] Optionally, the outer wall of the lens holder is provided with an internal thread, and the inner wall of the wavefront analyzer is provided with an external thread screwed to the internal thread of the lens holder, so that the collimating objective lens is mounted on the wavefront analyzer through the lens holder.

[0016] An embodiment of the present application provides a posture adjustment system for a collimating objective lens and a wavefront analyzer. The system can ensure that the optical axis of the light received by the collimating objective lens is perpendicular to the target surface of the wavefront analyzer by adjusting the position of the laser, the optical path transmission component and the optical path correction plate. This solves the problem in the prior art that when correcting the installation position of the collimating objective lens, on the one hand, the wave aberration of the off-axis field of view fluctuates greatly, which may cause measurement sensitivity errors; on the other hand, when docking with the image point of the object to be measured, the posture of the wavefront analyzer is difficult to accurately locate to the calibrated image point position of the collimating objective lens. When the telecentricity of the objective lens to be measured is large, it will also bring about the problem of not being able to fully receive the image point light cone. The collimating objective lens installed on the wavefront analyzer is accurately adjusted based on the light received by the collimating objective lens.

[0017] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 A schematic diagram of a posture adjustment system for a collimating objective lens and a wavefront analyzer provided in an embodiment of the present application;

[0020] Figure 2 A schematic diagram of another posture adjustment system for a collimating objective lens and a wavefront analyzer provided in an embodiment of the present application;

[0021] Figure 3 A schematic structural diagram of the connection relationship between a collimating objective lens and a wavefront analyzer provided in an embodiment of the present application;

[0022] Figure 4 A structural schematic diagram of the connection relationship between a collimating objective lens and a wavefront analyzer provided in an embodiment of the present application. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application for which protection is claimed, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, each other embodiment obtained by those skilled in the art without making creative work falls within the scope of protection of the present application.

[0024] First, the application scenarios to which this application is applicable are introduced. This application can be applied in the field of optical correction technology.

[0025] Research has found that as the feature size of chips in the integrated circuit industry continues to shrink, the performance requirements for exposure systems continue to increase. The aberration control of the projection objective is directly related to the quality of the exposure pattern linewidth. Therefore, it is necessary to conduct offline or online detection of the main performance parameters of the projection objective to ensure that they meet the equipment process requirements. The main detection parameters include wave aberration, distortion, magnification, astigmatism, IPD (Integrated Product Development) and NA (Numerical Aperture of the optical system) consistency.

[0026] The measurement sensor uses a Hartmann sensor. After light is refracted and focused by the objective lens, it is collimated by a collimating lens. Then, it passes through the Hartmann sensor's microlens array and is focused onto the CCD (charge-coupled device) target surface. To achieve measurement accuracy, the relative position of the collimating lens and wavefront analyzer must be calibrated to eliminate systematic errors caused by collimating lens tilt.

[0027] When calibrating the installation position of the collimating objective lens, on the one hand, the wavefront aberration of the off-axis field of view fluctuates greatly, which may cause measurement sensitivity errors. On the other hand, when docking with the image point of the object to be measured, the posture of the wavefront analyzer is difficult to accurately locate the calibrated collimating objective lens image point position. When the telecentricity of the objective lens to be measured is large, it may also lead to the situation where the image point light cone cannot be fully taken over.

[0028] Based on this, an embodiment of the present application provides a posture adjustment system for a collimating objective lens and a wavefront analyzer, which can accurately adjust the collimating objective lens installed on the wavefront analyzer based on the light received by the collimating objective lens.

[0029] See also Figure 1 , Figure 1 Schematic diagram of a posture adjustment system for a collimating objective lens and a wavefront analyzer provided in an embodiment of the present application. Figure 1 As shown in , the posture adjustment system provided by the embodiment of the present application includes: an optical platform 101, a laser 102, an optical path transmission component 103, an optical path correction plate 104, a collimating objective lens 105 and a wavefront analyzer 106.

[0030] The laser 102 is arranged at a first position of the optical platform 101 . A position fixing member is provided at the first position of the optical platform 101 for fixing the laser 102 and adjusting the height of the laser 102 to a standard height.

[0031] The wavefront analyzer 106 is arranged at the second position of the optical platform 101, and a position fixing member is provided at the first position of the optical platform 101 for fixing the wavefront analyzer 106 and adjusting the height of the wavefront analyzer 106 to a standard height so that the laser 102 and the wavefront analyzer 106 are in the same straight line.

[0032] The optical path transmission component 103 is arranged between the laser 102 and the wavefront analyzer 106.

[0033] See also Figure 2 , Figure 2 Schematic diagram of another posture adjustment system for a collimating objective lens and a wavefront analyzer provided in an embodiment of the present application. Figure 2 As shown in , the posture adjustment system provided by the embodiment of the present application includes: an optical platform 101, a laser 102, an optical path correction plate 104, a collimating objective lens 105, a wavefront analyzer 106, a laser beam expander 201, an Abbe prism 202, a laser focusing lens 205, a flat crystal 204, a micro-motion device 206, and an autocollimator 207, wherein the flat crystal 204 and the laser focusing lens 205 are arranged on the laser focusing plate 203.

[0034] Specifically, the optical path transmission component 103 includes a laser beam expander 201 , an Abbe prism 202 and a laser focusing lens 205 .

[0035] The laser beam expander 201 is arranged at the fourth position of the optical platform 101 and is fixed by an optical fixture capable of precisely adjusting the pitch and deflection angles.

[0036] Specifically, the laser beam emitted by the laser 102 is expanded by the laser beam expander 201 and then projected onto the target surface of the wavefront analyzer 106 on which the collimating objective lens 105 is not installed, forming a light spot on the target surface. According to the position of the light spot on the target surface, the installation angle of the laser beam expander 201 is adjusted so that the optical axis of the laser beam expander 201 coincides with the optical axis of the wavefront analyzer 106.

[0037] After the position and installation angle of the laser beam expander 201 are adjusted, the Abbe prism 202 is arranged at the fifth position of the optical platform 101 . The fifth position is between the fourth position and the wavefront analyzer 106 and close to the fourth position.

[0038] Here, a position fixing member is provided at the fifth position of the optical platform 101 for fixing the Abbe prism 202 and adjusting the height of the Abbe prism 202 to a standard height.

[0039] Specifically, the laser beam expanded by the adjusted laser beam expander 201 is emitted to the incident plane of the Abbe prism 202, and after being reflected by the Abbe prism 202, is emitted from the exit plane of the Abbe prism 202, and is projected onto the target surface of the wavefront analyzer 106 where the collimating objective lens 105 is not installed to form a light spot. According to the position of the light spot on the target surface, the installation angle of the Abbe prism 202 is adjusted so that the optical axis of the Abbe prism 202 coincides with the optical axis of the wavefront analyzer 106.

[0040] After the position and installation angle of the Abbe prism 202 are adjusted, the laser focusing lens 205 is arranged at the sixth position of the optical platform 101, where the sixth position is between the fifth position and the wavefront analyzer 106. The laser beam emitted from the output plane of the adjusted Abbe prism 202 is projected via the laser focusing lens 205 onto the target surface of the wavefront analyzer 106 where the collimating objective lens 105 is not installed. The installation angle of the laser focusing lens 205 is adjusted so that the optical axis of the laser focusing lens 205 coincides with the optical axis of the laser beam after being reflected by the Abbe prism 202.

[0041] In this way, after the above-mentioned adjustment of the optical path transmission component 103, the optical axes of the laser beam expander 201, the Abbe prism 202, and the laser focusing lens 205 of the optical path transmission component 103 coincide with each other, ensuring that the laser beam projected through the optical path transmission component coincides with the optical axis of the wavefront analyzer 106.

[0042] Optionally, see Figure 2 , the posture adjustment system also includes an autocollimator 207, such as Figure 2 As shown in the figure, the autocollimator 207 is installed on the fixing part of the optical platform 101 behind the wavefront analyzer 106. After the autocollimator 207 is installed on the fixing part of the optical platform 101, the autocollimator 207 can pass through the wavefront analyzer 106 and detect the installation angle of the plane in front of the wavefront analyzer 106 that is higher than the wavefront analyzer 106.

[0043] It should be noted that after the autocollimator 207 is mounted on the fixing member of the optical platform 101 behind the wavefront analyzer 106 , the mounting angle of the autocollimator 207 needs to be calibrated so that the autocollimator 207 can accurately detect the mounting angle of the plane.

[0044] Specifically, the autocollimator 207 is calibrated in the following manner: after the laser focusing lens 205 is not arranged on the optical platform 101 and the optical axis of the Abbe prism 202 is adjusted to coincide with the optical axis of the wavefront analyzer 106, the test light emitted by the autocollimator 207 is irradiated onto the exit plane of the Abbe prism 202, and the feedback light reflected from the exit plane of the Abbe prism 202 is received. The installation angle of the autocollimator 207 on the optical platform 101 is adjusted so that the test light of the autocollimator 207 coincides with the feedback light.

[0045] See also Figure 1 ,like Figure 1 As shown, the optical path correction plate 104 is arranged at a third position between the optical path guiding component and the wavefront analyzer 106 .

[0046] For details, please refer to Figure 2 ,like Figure 2 As shown, the optical path correction plate 104 is mounted on the micro-motion device 206 , and the micro-motion device 206 is arranged at the third position of the optical platform 101 . The optical path correction plate 104 is provided with a plurality of light-transmitting holes, each of which has a different size.

[0047] The installation angle of the optical path correction plate 104 is corrected in the following manner: the test light emitted by the autocollimator 207 is irradiated onto the optical path correction plate 104, and the feedback light reflected back by the optical path correction plate 104 is received, and the installation angle of the optical path correction plate 104 is adjusted so that the test light and the feedback light coincide with each other.

[0048] After adjusting the pitch angle of the optical path correction plate 104 by the autocollimator 207, the laser focusing lens 205 is removed, and the micro-motion device 206 is controlled to move to drive the optical path correction plate 104 to move, so that each light-transmitting hole on the optical path correction plate 104 is moved in order from large to small to the position where the focus of the collimating objective lens 105 is located. During each movement, the installation angle of the optical path correction plate 104 is adjusted so that the laser beam emitted through the exit plane of the Abbe prism 202 forms a light spot on the target surface of the wavefront analyzer 106 through the light-transmitting hole on the optical path correction plate 104 and is located at the center of the target surface.

[0049] After the laser beam emitted from the exit plane of the Abbe prism 202 passes through the light-transmitting hole on the optical path correction plate 104 and forms a light spot on the target surface of the wavefront analyzer 106 at the center of the target surface, the laser focusing mirror 205 is rearranged at the sixth position of the optical platform 101, and the installation angle of the laser focusing mirror 205 is adjusted so that the optical axis of the laser focusing mirror 205 coincides with the optical axis of the laser beam after being reflected by the Abbe prism 202.

[0050] At this time, the focal position after the laser focusing lens 205 focuses the laser beam emitted from the exit plane of the Abbe prism 202 is the position of the smallest light hole in the adjusted optical path correction plate 104 .

[0051] After the adjustment of the above-mentioned laser 102, optical path correction plate 104, laser beam expander 201, Abbe prism 202, laser focusing lens 205, flat crystal 204, micro-motion device 206, and autocollimator 207 is completed, the collimating objective lens 105 is adjustably installed on the side of the wavefront analyzer 106 close to the optical path correction plate 104, and the horizontal position of the wavefront analyzer 106 is adjusted so that the position of the light-transmitting hole on the optical path correction plate 104 is the position where the focus of the collimating objective lens 105 is located.

[0052] At this time, the laser beam emitted by the laser 102 is guided by the optical path guiding component and projected onto the target surface of the wavefront analyzer 106 via the light-transmitting hole on the optical path correction plate 104 and the collimating lens 105 to form a light spot on the target surface.

[0053] Then, according to the position of the light spot on the target surface, the installation angle of the collimating lens 105 is adjusted so that the optical axis of the collimating lens 105 coincides with the optical axis of the wavefront analyzer 106 .

[0054] For details, please refer to Figure 3 , Figure 3 A schematic diagram of the connection relationship between a collimating objective lens and a wavefront analyzer provided in an embodiment of the present application is shown in FIG. Figure 3As shown, the collimating objective lens 105 is mounted on a lens base 301 , on which an adjusting screw 302 and an elastic structure 303 are also provided.

[0055] See also Figure 4 , Figure 4 A schematic diagram of the connection between a collimating objective lens and a wavefront analyzer provided in an embodiment of the present application is shown in FIG. Figure 4 As shown, the collimating objective lens 105 is mounted on a lens base 301 , and an adjusting screw 302 and an elastic structure 303 are also provided on the lens base 301 .

[0056] Specifically, the posture adjustment system also includes a lens mount 301 and an adjusting screw 302. The collimating objective lens 105 is mounted on the wavefront analyzer through the lens mount 301. The adjusting screw 302 is used to adjust the installation angle of the collimating objective lens 105 relative to the wavefront analyzer so that the optical axis of the collimating objective lens 105 coincides with the optical axis of the wavefront analyzer.

[0057] The elastic structure 303 is used to tighten the collimating lens 105 and the wavefront analyzer to ensure the connection stiffness between the collimating lens 105 and the wavefront analyzer, thereby ensuring the pre-tightening force of the adjusting screw 302 .

[0058] Specifically, the adjusting screw 302 can be adjusted according to the offset between the position of the light spot on the target surface and the target surface center of the wavefront analyzer to make the optical axis of the collimating objective lens 105 coincide with the optical axis of the wavefront analyzer.

[0059] Exemplarily, the deflection angles of the collimating objective lens 105 in the horizontal direction Rx and the vertical direction Ry on the target surface of the wavefront analyzer are θx and θy, respectively. The deflection arm length of the collimating objective lens 105 around the fulcrum is L, wherein the deflection arm length is the vertical distance between the surface of the shell supported by the adjusting screw 302 and the image point position of the collimating objective lens 105. The field of view deflection of the collimating objective lens 105 introduced by the deflection angles θx and θy is Δhx and Δhy, and the Hartmann upper incident angle deviation introduced by the field of view deflection is θx′ and θy′. The relationship between the incident angle of the collimating objective lens 105 and the field of view satisfies:

[0060]

[0061] Under the requirements of small-scale alignment and field of view deflection, alignment and adjustment satisfy the following relationship:

[0062] thetaX=θx+θx′;

[0063] thetaY=θy+θy′;

[0064] Δhx=L×θx;

[0065] Δhy=L×θy;

[0066]

[0067]

[0068] In this way, the tilt angle that needs to be adjusted can be calculated based on the above formula, and then the adjusting screw 302 is adjusted according to the tilt angle that needs to be adjusted to make the optical axis of the collimating lens 105 coincide with the optical axis of the wavefront analyzer.

[0069] Optionally, the outer wall of the lens holder 301 is provided with an internal thread, and the inner wall of the wavefront analyzer is provided with an external thread screwed to the internal thread of the lens holder 301 , so that the collimating objective lens 105 is mounted on the wavefront analyzer through the lens holder 301 .

[0070] An embodiment of the present application provides a posture adjustment system for a collimating objective lens and a wavefront analyzer. The system can ensure that the optical axis of the light received by the collimating objective lens is perpendicular to the target surface of the wavefront analyzer by adjusting the position of the laser, the optical path transmission component and the optical path correction plate. This solves the problem in the prior art that when correcting the installation position of the collimating objective lens, on the one hand, the wave aberration of the off-axis field of view fluctuates greatly, which may cause measurement sensitivity errors; on the other hand, when docking with the image point of the object to be measured, the posture of the wavefront analyzer is difficult to accurately locate to the calibrated image point position of the collimating objective lens. When the telecentricity of the objective lens to be measured is large, it will also bring about the problem of not being able to fully receive the image point light cone. The collimating objective lens installed on the wavefront analyzer is accurately adjusted based on the light received by the collimating objective lens.

[0071] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0072] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. There may be other division methods in actual implementation. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed may be through some communication interface, indirect coupling or communication connection of devices or units, which may be electrical, mechanical or other forms.

[0073] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0074] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0075] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium that is executable by a processor. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0076] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The scope of protection of the present application is not limited thereto. Although the present application has been described in detail with reference to the above-mentioned embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily conceive of changes to the technical solutions described in the above-mentioned embodiments within the technical scope disclosed in the present application, or perform equivalent replacements for some of the technical features thereof. These modifications, changes, or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A posture adjustment system for a collimating objective lens and a wavefront analyzer, characterized in that: The posture adjustment system includes a laser, a light path transmission component and a light path correction plate, wherein the light path correction plate is provided with a light-transmitting hole. The laser is arranged at a first position of the optical platform, the wavefront analyzer is arranged at a second position of the optical platform, the optical path transmission component is arranged between the laser and the wavefront analyzer, the optical path correction plate is arranged at a third position between the optical path transmission component and the wavefront analyzer, the collimating objective lens is adjustably installed on a side of the wavefront analyzer close to the optical path correction plate, and the position of the light transmission hole on the optical path correction plate is the position of the focus of the collimating objective lens. The laser beam emitted by the laser is guided by the optical path guiding component and projected onto the target surface of the wavefront analyzer via the light-transmitting hole on the optical path correction plate and the collimating objective lens to form a light spot on the target surface. According to the position of the light spot on the target surface, the installation angle of the collimating objective lens is adjusted so that the optical axis of the collimating objective lens coincides with the optical axis of the wavefront analyzer. The optical path transmission components include a laser beam expander, an Abbe prism and a laser focusing lens. Among them, the laser beam expander is arranged at the fourth position of the optical platform. The laser beam emitted by the laser is expanded by the laser beam expander and projected onto the target surface of the wavefront analyzer without the collimating objective lens installed, forming a light spot on the target surface. According to the position of the light spot on the target surface, the installation angle of the laser beam expander is adjusted so that the optical axis of the laser beam expander coincides with the optical axis of the wavefront analyzer. The Abbe prism is arranged at the fifth position of the optical platform, and the fifth position is located between the fourth position and the wavefront analyzer and close to the fourth position. The laser beam expanded by the adjusted laser beam expander is emitted to the incident plane of the Abbe prism, and after being reflected by the Abbe prism, is emitted from the exit plane of the Abbe prism and projected onto the target surface of the wavefront analyzer without the collimating objective lens to form a light spot. According to the position of the light spot on the target surface, the installation angle of the Abbe prism is adjusted so that the optical axis of the Abbe prism coincides with the optical axis of the wavefront analyzer. Among them, the laser focusing mirror is arranged at the sixth position of the optical platform, and the sixth position is located between the fifth position and the wavefront analyzer. The laser beam emitted from the output plane of the adjusted Abbe prism is projected onto the target surface of the wavefront analyzer without the collimating objective lens installed through the laser focusing mirror. The installation angle of the laser focusing mirror is adjusted so that the optical axis of the laser focusing mirror coincides with the optical axis of the laser beam after reflection from the Abbe prism.

2. The posture adjustment system according to claim 1, characterized in that: The posture adjustment system also includes a flat crystal and an autocollimator. The flat crystal is arranged on a first side surface of the laser focusing plate facing the collimating autocollimator. The laser focusing plate is located above the laser focusing mirror. The second side surface of the laser focusing plate is fixedly connected to the edge of the laser focusing mirror. The setting height of the flat crystal is higher than the height of the upper edge of the wavefront analyzer. The autocollimator is arranged at the seventh position of the optical platform. The seventh position is located on the other side of the wavefront analyzer away from the laser. The setting height of the autocollimator arranged at the seventh position is higher than the height of the upper edge of the wavefront analyzer and is used to detect the installation angle of any plane in front of the wavefront analyzer. Among them, the test light emitted by the autocollimator is irradiated onto the flat crystal, and the feedback light reflected back by the flat crystal is received. The installation angle of the laser focusing plate is adjusted to make the test light coincide with the feedback light, so that the optical axis of the laser focusing mirror on the laser focusing plate coincides with the optical axis of the laser beam after reflection by the Abbe prism.

3. The posture adjustment system according to claim 1, characterized in that: The posture adjustment system also includes an autocollimator, which is calibrated in the following ways: Without arranging the laser focusing lens on the optical platform and after adjusting the optical axis of the Abbe prism to coincide with the optical axis of the wavefront analyzer, the test light emitted by the autocollimator is irradiated onto the exit plane of the Abbe prism, and the feedback light reflected back from the exit plane of the Abbe prism is received. The installation angle of the autocollimator on the optical platform is adjusted so that the test light of the autocollimator coincides with the feedback light.

4. The posture adjustment system according to claim 1, characterized in that: The posture adjustment system also includes an autocollimator, and the installation angle of the optical path correction plate is corrected by the following method: The test light emitted by the autocollimator is irradiated onto the optical path correction plate, and the feedback light reflected by the optical path correction plate is received. The installation angle of the optical path correction plate is adjusted to make the test light coincide with the feedback light.

5. The posture adjustment system according to claim 4, characterized in that: The posture adjustment system further includes a micro-motion device, the optical path correction plate is mounted on the micro-motion device, the micro-motion device is arranged at a third position of the optical platform, and the optical path correction plate is provided with a plurality of light-transmitting holes, each light-transmitting hole having a different size. The laser focusing mirror is removed, and the micro-motion device is controlled to move to drive the optical path correction plate to move each light-transmitting hole on the optical path correction plate in order from large to small to the position where the focus of the collimating objective lens is located. During each movement, the installation angle of the optical path correction plate is adjusted so that the laser beam emitted through the exit plane of the Abbe prism forms a light spot on the target surface of the wavefront analyzer through the light-transmitting hole on the optical path correction plate at the center of the target surface.

6. The posture adjustment system according to claim 5, characterized in that: The laser focusing mirror is rearranged at the sixth position of the optical platform, and the installation angle of the laser focusing mirror is adjusted so that the optical axis of the laser focusing mirror coincides with the optical axis of the laser beam reflected by the Abbe prism.

7. The posture adjustment system according to claim 1, characterized in that: The posture adjustment system also includes a lens mount and an adjusting screw. The collimating objective lens is mounted on the wavefront analyzer through the lens mount. The adjusting screw is used to adjust the mounting angle of the collimating objective lens relative to the wavefront analyzer so that the optical axis of the collimating objective lens coincides with the optical axis of the wavefront analyzer.

8. The posture adjustment system according to claim 7, characterized in that: According to the offset between the position of the light spot on the target surface and the center of the target surface of the wavefront analyzer, the adjusting screw is adjusted to make the optical axis of the collimating objective lens coincide with the optical axis of the wavefront analyzer.

9. The posture adjustment system according to claim 7, characterized in that: The outer wall of the lens holder is provided with an internal thread, and the inner wall of the wavefront analyzer is provided with an external thread screwed to the internal thread of the lens holder, so that the collimating objective lens can be installed on the wavefront analyzer through the lens holder.

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