Bending correction method for movable reflector, interferometer measurement system and storage medium

Abstract

This application discloses a method for correcting the curvature of a movable reflector, an interferometer measurement system, and a storage medium. The method comprises: calculating the curvature difference at each measurement point of the movable reflector; removing the tilt component from the curvature difference; interpolating the curvature difference after removing the tilt component to generate correction values ​​distributed at preset intervals; and compensating the correction values ​​into the displacement calculation results of the interferometer measurement system. The embodiments of the present application correct errors at the measurement end, resolving the difficulty of data processing in related technologies.

Description

Technical Field

[0001] The present application relates to a bending correction method for a movable reflector, an interferometer measurement system and a storage medium, and belongs to the field of laser measurement. Background Art

[0002] In semiconductor applications, high-precision motion displacement measurement often relies on laser interferometer systems, achieving nanometer or even sub-nanometer accuracy. The moving mirror in the interferometer system, as a key optical component, requires extremely high machining precision. In practice, the moving mirror is fixed near the object being measured, and its surface machining accuracy and deformation directly affect the measurement results. Therefore, minimizing or eliminating the impact of this deformation is crucial.

[0003] Ideally, a movable mirror should be free of bending. However, slight deformation is inevitable after installation and tightening. Environmental changes or movement can also cause deformation. Most related technologies use algorithms to post-process the measurement data, but this method has high data processing requirements and does not compensate for system error sources. Summary of the Invention

[0004] In view of this, the present application provides a bending correction method for a movable reflector, an interferometer measurement system and a storage medium. The embodiments of the present application correct the error at the measurement end, solving the problem of high difficulty in data processing in related technologies.

[0005] A first aspect of an embodiment of the present application discloses a method for correcting the bending of a movable reflector, the method comprising:

[0006] Calculating the bending difference of each measuring point of the movable reflector;

[0007] removing a tilt component from the bend difference;

[0008] interpolating the curvature difference after removing the tilt component to generate correction values ​​distributed at preset intervals;

[0009] The correction value is compensated into the displacement calculation result of the interferometer measurement system.

[0010] In one embodiment, calculating the bending difference of each measuring point of the movable reflector includes:

[0011] Controlling the motion stage to move in a first direction with a fixed step distance;

[0012] At each step position, the measurement values ​​of the two measurement axes in the second direction are read and the bending difference is calculated. The two measurement axes include a first measurement axis and a second measurement axis. The bending difference represents the increase or decrease in the measurement value of the first measurement axis relative to the second measurement axis at the step position.

[0013] In one embodiment, before calculating the bending difference, the method further includes:

[0014] Obtaining tilt data of the movable reflector and performing yaw correction on the measured values.

[0015] In one embodiment, obtaining the tilt data of the movable reflector and performing yaw correction on the measured value includes:

[0016] The measured values ​​are corrected by the difference in curvature of the two measuring axes in the first direction.

[0017] In one embodiment, removing the tilt component from the curvature difference comprises:

[0018] For all bending differences, connect the first and last shape points to obtain the tilt component;

[0019] The tilt component is removed from each shape point.

[0020] A second aspect of an embodiment of the present application discloses an interferometer measurement system, the system comprising:

[0021] an emitting unit configured to emit laser light including a first polarized light and a second polarized light;

[0022] An optical path unit, comprising a polarization beam splitter, a movable reflector, a fixed reflector, and a 1 / 4λ polarizing plate, wherein the polarization beam splitter directs the first polarized light to the movable reflector and the second polarized light to the fixed reflector. After the two beams are processed by the 1 / 4λ polarizing plate, the movable reflector and the fixed reflector realize beam folding, thereby forming a dual-channel optical path and a quadratic round-trip optical path difference.

[0023] a detection unit including an interferometric measurement axis;

[0024] The processing unit is configured to perform photoelectric conversion on the dual-channel interference signal and is used to execute the bending correction method of the above embodiment.

[0025] In one embodiment, the first polarized light is vertically polarized light, the second polarized light is horizontally polarized light, and the frequency of the first polarized light is different from the frequency of the second polarized light.

[0026] In one embodiment, the polarization beam splitter is provided on an outgoing light path of the emitting portion and is configured to split the laser light into the first polarized light and the second polarized light;

[0027] The movable reflector and the fixed reflector receive the first polarized light and the second polarized light respectively, and return the corresponding light beams to the polarization beam splitter to form a detection area, and the normal directions of the two mirror surfaces are orthogonal to each other;

[0028] The 1 / 4λ polarizing plates are respectively arranged in the incident light paths of the movable reflector and the fixed reflector, and are located between the corresponding reflectors and the polarization beam splitter.

[0029] In one embodiment, the detection unit includes four interferometric measurement axes, which are configured to be symmetrically arranged in the first direction and the second direction.

[0030] A third aspect of the embodiments of the present application discloses a computer-readable storage medium, which includes a stored program. When the program is run, a processor of a device is controlled to execute the bending correction method of the above embodiment.

[0031] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0032] Embodiments of the present application provide a method for correcting the curvature of a movable reflector, an interferometer measurement system, and a storage medium. The method includes calculating the curvature difference at each measurement point on the movable reflector; removing the tilt component from the curvature difference; interpolating the curvature difference after removing the tilt component to generate correction values ​​distributed at preset intervals; and compensating the correction values ​​into the displacement calculation results of the interferometer measurement system. Embodiments of the present application can be used to correct the curvature of an interferometer movable mirror, improving displacement measurement accuracy, reducing measurement errors, and simplifying subsequent data processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without any creative work.

[0034] Figure 1 A schematic diagram of a curved movable mirror provided in an embodiment of the present application.

[0035] Figure 2 A schematic diagram of a corrected movable mirror provided in an embodiment of the present application.

[0036] Figure 3 A structural block diagram of an optical path provided in an embodiment of the present application.

[0037] Figure 4 A schematic diagram of four interferometric measurement axes provided in an embodiment of the present application.

[0038] Figure 5This is a flow chart of a method for correcting the bending of a movable reflector provided in an embodiment of the present application.

[0039] Figure 6 A schematic diagram of round-trip motion detection provided in an embodiment of the present application.

[0040] Figure 7 A schematic diagram of yaw data compensation provided in an embodiment of the present application.

[0041] Figure 8 A schematic diagram of shape data calculation provided in an embodiment of the present application.

[0042] Figure 9 A schematic diagram of multiple shape points provided in an embodiment of the present application.

[0043] Figure 10 A schematic diagram of shape points after removing tilt components provided in an embodiment of the present application.

[0044] Figure 11 A schematic diagram of tilt data calculation provided in an embodiment of the present application.

[0045] Figure 12 A schematic diagram of a tilt measurement point and a shape measurement point provided in an embodiment of the present application.

[0046] Figure 13 A schematic diagram of the shape of a reflector after shape point interpolation provided in an embodiment of the present application.

[0047] Figure 14 This is a structural block diagram of a bending correction device for a movable reflector provided in an embodiment of the present application. DETAILED DESCRIPTION

[0048] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0049] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0050] Example 1:

[0051] In semiconductor applications, high-precision motion displacement measurement often relies on laser interferometer systems, achieving nanometer or even sub-nanometer accuracy. The moving mirror in the interferometer system, as a key optical component, requires extremely high machining precision. In practice, the moving mirror is fixed near the object being measured, and its surface machining accuracy and deformation directly affect the measurement results. Therefore, minimizing or eliminating the impact of this deformation is crucial.

[0052] Ideally, the movable reflector should not bend, but slight deformation is inevitable after installation and tightening. Environmental changes or movement may also cause deformation, such as Figure 1 Most related technologies use algorithms to post-process measurement data, but this method has high requirements for data processing and does not compensate for system error sources.

[0053] To solve this problem, the present invention proposes the following solutions to achieve Figure 2 The effect of the bend correction is shown.

[0054] Figure 3 This is a structural block diagram of an interferometer measurement system provided in an embodiment of the present application, such as Figure 3As shown, the interferometer measurement system includes: an emitting unit 301 configured to emit a laser including a first polarized light and a second polarized light; an optical path unit including a polarization beam splitter 3021, a movable reflector 3022, a fixed reflector 3023, and a 1 / 4λ polarizing plate 304. The polarization beam splitter (specifically, a polarization beam splitter) guides the first polarized light to the movable reflector and the second polarized light to the fixed reflector. After the two beams are processed by the 1 / 4λ polarizing plate, the movable reflector and the fixed reflector (specifically, a corner cube) realize beam folding, thereby forming a dual-channel optical path and a secondary round-trip optical path difference; a detection unit 303 including an interferometric measurement axis for measuring a dual-channel interference signal of area A; and a processing unit configured to perform photoelectric conversion on the dual-channel interference signal and to execute the bending correction method of this embodiment.

[0055] The aforementioned polarization beam splitter is a common optical component that can split incident light into two beams of orthogonal polarization (such as P light and S light) and is widely used in laser systems, interferometers, imaging, and other fields.

[0056] The aforementioned corner cube is a common optical component whose core characteristic is that it can accurately reflect incident light along its original path without being affected by the incident angle.

[0057] The 1 / 4λ polarizer is a common optical component that can introduce phase delay to light of a specific wavelength, thereby changing the polarization state of the light. It is widely used in laser systems, optical measurement, communications, and other fields.

[0058] In some embodiments, the first polarized light is vertically polarized light, the second polarized light is horizontally polarized light, and the frequency of the first polarized light is different from the frequency of the second polarized light.

[0059] In some embodiments, the polarization beam splitter is arranged on the outgoing light path of the emitting part and is configured to split the laser into the first polarized light and the second polarized light; the movable reflector and the fixed reflector respectively receive the first polarized light and the second polarized light, and return the corresponding light beams to the polarization beam splitter, and the normal directions of the two mirrors are orthogonal to each other; the 1 / 4λ polarizing plate is respectively arranged in the incident light path of the movable reflector and the fixed reflector, and is located between the corresponding reflector and the polarization beam splitter.

[0060] In this embodiment, the polarization beam splitter is configured to transmit the first polarized light to a movable reflector and reflect the second polarized light to a fixed reflector. The first polarized light is vertically polarized, and the second polarized light is horizontally polarized. A ¼λ polarizer is disposed in the optical path between the movable reflector and the fixed reflector and is configured to convert the first polarized light into a first left-circularly polarized light and the second polarized light into a first right-circularly polarized light. The movable reflector and the fixed reflector are configured to reverse the phases of the first left-circularly polarized light and the first right-circularly polarized light by reflection (changing the phase by 180°), converting them into a second right-circularly polarized light and a second left-circularly polarized light, respectively. The ¼λ polarizer is configured to convert the second right-circularly polarized light into horizontal polarized light and the second left-circularly polarized light into vertical polarized light. It is understood that the horizontally polarized light is transmitted through the polarization beam splitter into a corner cube, while the vertically polarized light is reflected through the polarization beam splitter into the corner cube. After processing by the corner cube (changing the optical path direction), the two beams return to the polarization beam splitter, completing a second round trip and forming a double-pass interferometry optical path.

[0061] When the movable mirror moves, it leaves a corresponding interference signal in area A, which is used as the basis for bending measurement.

[0062] In one embodiment, the interferometer measurement system consists of the following units:

[0063] (1) Laser unit: It includes a laser head and an emitting unit, which emits two beams of orthogonal polarized light.

[0064] (2) Optical path unit: includes reference optical path and detection optical path, used for measuring the optical path difference caused by laser transmission and motion stage displacement.

[0065] (3) Detection unit: includes a signal receiver and a relay control board, which receives and pre-processes the laser signal.

[0066] (4) Processing unit: includes the interferometer axis card and measurement control board, converts the optical signal into an electrical signal and calculates the displacement.

[0067] In some embodiments, the detection unit includes four interferometric measurement axes configured to be symmetrically arranged in the first direction and the second direction.

[0068] In this embodiment, Figure 4 As shown, the horizontal X-axis and the vertical Y-axis have two measuring axes (xl and xr, yl and yr, or XL and XR, YL and YR).

[0069] In this embodiment, the method for correcting the bending of the movable reflector is summarized as follows:

[0070] The curvature of the moving mirror is detected by the wafer stage interferometer (xl, xr, yr, yl measurement axes). When the wafer chuck center is directly below the projection lens (wafer stage origin):

[0071] Measurement method: With the wafer stage as the center, measure 8 designated positions of the movable mirror in the X / Y direction;

[0072] Data type: Shape data (mirror profile deviation) and tilt data (local angle change) need to be acquired simultaneously;

[0073] Correction processing: Based on the measurement results, the bending correction value of the X / Y direction movable mirror is calculated at 1.29mm intervals and compensation is implemented.

[0074] Figure 5 A flow chart of a method for correcting the bending of a movable reflector provided in an embodiment of the present application is shown in FIG. Figure 5 As shown, the bending correction method includes:

[0075] S501 calculates the bending difference of each measuring point of the movable reflector.

[0076] In this step, the calculation of the bending difference of each measuring point of the movable reflector includes:

[0077] S5011 controls the motion stage to move in a fixed step distance in a first direction.

[0078] S5012 reads the measurement values ​​of the two measurement axes in the second direction at each step position and calculates the bending difference, wherein the two measurement axes include a first measurement axis and a second measurement axis, and the bending difference represents the increase or decrease in the measurement value of the first measurement axis relative to the second measurement axis at the step position.

[0079] Specifically, if Figure 6 As shown, wafer stage 30 includes an X-axis moving mirror 10 and a Y-axis moving mirror 20. Taking the Y-axis moving mirror as an example, the wafer stage is stepped seven times along the X direction at 35mm intervals (corresponding to the installation spacing of interferometers yl and yr). Eight measurement points are obtained: ①, ②, ③, ④, ⑤, ⑥, ⑦, and ⑧. The yl and yr readings are recorded at each position, and the average value is obtained through round-trip measurements.

[0080] Specifically, if Figure 8 As shown, at each measurement point (shape data counting point), the difference P (shape data) is calculated based on the interferometer values ​​of yl and yr. This difference represents the increase or decrease in yl relative to the yr value. P(i) = yr(i) - yl(i), where yl(i) is the interferometer measurement value of yl, yr(i) is the interferometer measurement value of yr, and i is the shape measurement number, 1 ≤ i ≤ 7. In this embodiment, the shape measurement count is 7, which can be understood as the number of points involved in the shape change.

[0081] Specifically, if Figure 9 As shown, assuming that the initial value is 0, the shape measurement value P is accumulated in the direction from 1 to 7, then the shape points P(1)=0, P(i+1)= .

[0082] In this embodiment, before calculating the bending difference, the method further includes:

[0083] Obtaining tilt data of the movable reflector and performing yaw correction on the measured values.

[0084] Possibly, the tilt data of the moving mirror are acquired by a neural network algorithm.

[0085] Furthermore, the acquiring the tilt data of the movable reflector and performing yaw correction on the measured value includes:

[0086] The measured values ​​are corrected by the difference in curvature of the two measuring axes in the first direction.

[0087] Specifically, if Figure 7 As shown, the yaw error compensation is performed on the yr and yl values ​​using the difference D and the tilt angle calculated from the installation spacing of xr and xl.

[0088] S502 removes the tilt component from the bending difference.

[0089] In this step, removing the tilt component from the bending difference includes:

[0090] S5021 connects the first and last shape points for all bending differences to obtain the tilt component.

[0091] S5022 removes the tilt component from each shape point.

[0092] Specifically, Figure 9 Connect the beginning and end of the shape point in a straight line to obtain the tilt component of the movable reflector of the wafer stage, and remove it from each shape point to obtain the following Figure 10 The image shown.

[0093] S503 performs interpolation processing on the curvature difference after removing the tilt component, and generates correction values ​​distributed at preset intervals.

[0094] In this embodiment, Figure 11 and Figure 12As shown, the tilt data of the movable mirror is measured and used as an interpolation of the shape point information calculated from the shape data. Each measurement point is placed at the center of the interferometers yl and yr, and their respective values ​​are read. Specifically, based on the read interferometer values ​​yl and yr, the difference S (tilt data) between the two is calculated: S(i) = yr(i) - yl(i), where yl(i) is the yl interferometer measurement value, yr(i) is the yr interferometer measurement value, and i is the tilt measurement number, 1≤i≤8. At this point, the yl and yr values ​​can be yaw-corrected, similar to the shape data measurement step in the above-described embodiment. It should be noted that, unlike the shape data measurement step in the above-described embodiment, this step changes the measurement point position. For other embodiments, the measurement point position may not be changed.

[0095] In one embodiment, spline interpolation and correction value calculation:

[0096] 1. Based on all 8 shape points in the X direction (xi(k), yi(k)), 1≤k≤8) and tilt data (s(k), 1≤k≤8) obtained from the measurements, calculate the interpolation polynomial for the shape point interval.

[0097] 2. Interpolate the shape points through the interpolation polynomial of each interval [xi(k)≤x≤xi(k+1), 1≤k≤7] of the shape points, such as Figure 13 shown.

[0098] 3. Calculate the shape of the wafer stage moving mirror based on the interpolation polynomial for each interval to calculate the correction value at intervals of 1.29 mm in the X direction.

[0099] 4. Calculate the correction value for the X-axis moving mirror by referring to the above method.

[0100] S504: Compensating the correction value into the displacement calculation result of the interferometer measurement system.

[0101] Example 2:

[0102] Figure 14 A schematic structural diagram of a bending correction device for a movable reflector provided in an embodiment of the present application is shown in FIG. Figure 14 As shown, the bending correction device includes:

[0103] The calculation module 1401 is used to calculate the bending difference of each measuring point of the movable reflector.

[0104] The removal module 1402 is configured to remove the tilt component from the bending difference.

[0105] The generating module 1403 is configured to perform interpolation processing on the curvature difference after removing the tilt component, and generate correction values ​​distributed at preset intervals.

[0106] The compensation module 1404 is configured to compensate the correction value into the displacement calculation result of the interferometer measurement system.

[0107] Example 3:

[0108] An embodiment of the present application further provides an electronic device, comprising: a memory storing an executable program; and a processor for running the program, wherein the program executes the methods of various embodiments of the present invention when running.

[0109] The above-mentioned memory may refer to a device inside a computer for storing data and programs, and may include memory, hard disk, etc., wherein the memory may be used to temporarily store running programs and data, the hard disk may be used to store programs and data for a long time, and the memory may be used to enable the computer to read and write data, as well as execute programs; the above-mentioned processor may be responsible for executing instructions in computer programs and performing data processing, and may be responsible for controlling and executing various operations, including arithmetic operations, logical operations, data transmission, etc.

[0110] Example 4:

[0111] An embodiment of the present application further provides a computer-readable storage medium, which includes a stored executable program, wherein when the executable program is running, the device where the computer-readable storage medium is located is controlled to execute the methods in various embodiments of the present invention.

[0112] The above-mentioned computer storage medium may refer to a medium in a computer memory used to store certain discontinuous physical quantities. Computer storage media mainly include semiconductors, magnetic cores, magnetic drums, magnetic tapes, laser disks, etc. The stored program included in the computer-readable storage medium may be a set of instructions that can be recognized and executed by a computer, running on an electronic computer, and serving as an information tool to meet certain needs of people.

[0113] Example 5:

[0114] An embodiment of the present application further provides a computer program product, including a computer program, which implements the methods in various embodiments of the present invention when executed by a processor.

[0115] The above-mentioned computer program product may refer to a software program that has been written, tested and released, which can be run on a computer or other device. The computer program product may include an application, an operating system, tool software, etc., which is used to implement specific functions or solve specific problems.

[0116] Example 6:

[0117] An embodiment of the present application further provides a computer program product, including a non-volatile computer-readable storage medium, wherein the non-volatile computer-readable storage medium is used to store a computer program, and when the computer program is executed by a processor, the method in each embodiment of the present invention is implemented.

[0118] The above-mentioned non-volatile computer-readable storage medium may refer to a medium for storing data. The non-volatile computer-readable storage medium can keep the data from being lost when the power is off, and can be used to store long-term data, such as operating systems, applications and user files. The non-volatile storage medium may include hard disk drives, solid-state drives, optical disks and flash memory storage devices, etc.

[0119] Example 7:

[0120] The embodiments of the present application further provide a computer program, which implements the methods in the above-mentioned embodiments of the present invention when executed by a processor.

[0121] The above-mentioned computer program may refer to a collection of instructions used to tell a computer to perform a specific task or operation. A computer program may be written by a programmer using a specific programming language and may include algorithms, data structures, logic, and control flows. Computer programs may be used for a variety of purposes, including application software, operating systems, and the like.

[0122] In the above embodiments of the present invention, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0123] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only exemplary. For example, the division of the units can be a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0124] 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 units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0125] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0126] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes various media that can store program code, such as a USB flash drive, read-only memory (ROM), random access memory (RAM), a mobile hard drive, a magnetic disk, or an optical disk.

[0127] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for correcting the bending of a movable reflector, characterized in that: include: Calculating the bending difference of each measuring point of the movable reflector, comprising: Controlling the motion stage to move in a first direction with a fixed step distance; At each step position, reading the measurement values ​​of two measurement axes in the second direction and calculating a bending difference, the two measurement axes including a first measurement axis and a second measurement axis, the bending difference representing an increase or decrease in the measurement value of the first measurement axis relative to the measurement value of the second measurement axis at the step position; Removing the tilt component from the bend difference comprises: For all bending differences, connect the first and last shape points to obtain the tilt component; removing the tilt component from each shape point; interpolating the curvature difference after removing the tilt component to generate correction values ​​distributed at preset intervals; The correction value is compensated into the displacement calculation result of the interferometer measurement system.

2. The bending correction method according to claim 1, characterized in that: Before calculating the bending difference, the method further includes: Obtaining tilt data of the movable reflector and performing yaw correction on the measured values.

3. The bending correction method according to claim 2, characterized in that: The step of obtaining the tilt data of the movable reflector and performing yaw correction on the measured value comprises: The measured values ​​are corrected by the difference in curvature of the two measuring axes in the first direction.

4. An interferometer measurement system, characterized in that include: an emitting unit configured to emit laser light including a first polarized light and a second polarized light; An optical path unit, comprising a polarization beam splitter, a movable reflector, a fixed reflector, and a 1 / 4λ polarizing plate, wherein the polarization beam splitter directs the first polarized light to the movable reflector and the second polarized light to the fixed reflector. After the two beams are processed by the 1 / 4λ polarizing plate, the movable reflector and the fixed reflector realize beam folding, thereby forming a dual-channel optical path and a quadratic round-trip optical path difference. a detection unit including an interferometric measurement axis; A processing unit is configured to perform photoelectric conversion on the dual-channel interference signal and is used to execute the bending correction method described in any one of claims 1 to 3.

5. The interferometer measurement system according to claim 4, characterized in that The first polarized light is vertically polarized light, the second polarized light is horizontally polarized light, and the frequency of the first polarized light is different from the frequency of the second polarized light.

6. The interferometer measurement system according to claim 4, characterized in that The polarization beam splitter is provided on the outgoing light path of the emitting portion and is configured to split the laser light into the first polarized light and the second polarized light; The movable reflector and the fixed reflector receive the first polarized light and the second polarized light respectively, and return the corresponding light beams to the polarization beam splitter to form a detection area, and the normal directions of the two mirror surfaces are orthogonal to each other; The 1 / 4λ polarizing plates are respectively arranged in the incident light paths of the movable reflector and the fixed reflector, and are located between the corresponding reflectors and the polarization beam splitter.

7. The interferometer measurement system according to claim 4, characterized in that The detection unit includes four interferometric measurement axes configured to be symmetrically arranged in a first direction and a second direction.

8. A computer-readable storage medium, characterized in that The computer-readable storage medium includes a stored program, wherein when the program is executed, the bending correction method according to any one of claims 1 to 3 is executed in a processor of a device where the program is controlled.

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