System error calibration method for phase-shift point diffraction interferometer based on mask rotation

Abstract

This invention discloses a system error calibration method for a phase-shifting point diffraction interferometer based on mask rotation. The proposed method requires a simple hardware structure and, compared to traditional point diffraction interferometer calibration methods, does not add any additional optical modules, enabling sub-nanometer-level system error calibration. The proposed method precisely controls the mask rotation angle by rotating alignment marks, making the diffraction error caused by pinhole diffraction a variable before and after rotation. Furthermore, it utilizes the orthogonality and parity-even symmetry properties of Zernike polynomials in the unit circle domain to calibrate the pinhole diffraction error. Compared to conventional mask replacement methods and rotating the optical system under test methods, this method further reduces system error; and compared to methods that involve multiple pinhole rotations and averaging, it reduces operational complexity.

Description

Technical Field

[0001] This invention belongs to the field of interferometric measurement and image processing technology, specifically relating to a system error calibration method for a phase-shifting point diffraction interferometer based on mask rotation. Background Technology

[0002] Optical measurement and inspection technologies are crucial supports for modern precision manufacturing, particularly the development of the integrated circuit industry. In the field of integrated circuit manufacturing, photolithography is a core component, and the imaging quality of its projection lens directly determines the feature size and yield of the chip. As feature sizes continue to approach physical limits, such as from DUV (Deep Ultraviolet) to EUV (Extremely Ultraviolet) lithography, unprecedented demands are placed on the wavefront aberration detection accuracy of the projection lens, moving from the nanometer level to the sub-nanometer and even picometer level.

[0003] Traditional interferometers, such as those based on Fizeau or Twyman-Green structures, play a crucial role in wavelet aberration detection of optical components or systems. However, these interferometers typically rely on highly precision-manufactured standard reference surfaces. When facing the stringent requirements of photolithography for detection accuracy down to a few nanometers or even lower, the surface shape errors, surface contamination, and long-term stability of the standard reference surface directly introduce systematic errors, becoming a major bottleneck limiting measurement accuracy. Furthermore, in actual production environments, environmental factors such as vibration, airflow disturbances, and temperature variations can easily interfere with the measurement results of traditional interferometers, reducing measurement stability and reliability.

[0004] Phase-Shifting Point Diffraction Interferometer (PSPDI), as a high-precision, self-referencing wavefront measurement technique, provides a powerful solution to the problem of high-precision wavefront aberration detection. The core idea of ​​PSPDI is to generate a near-ideal spherical reference wave through diffraction at a small aperture, and then interfere with the wavefront to be measured in a common optical path. This eliminates the dependence on a standard plane and enables high-precision, environmentally robust wavefront measurement of optical components and systems within a common optical path.

[0005] Current error calibration methods for phase-shifting point diffraction systems are mainly divided into two categories: calibration methods based on rotating the optical system under test or the phase-shifting grating, and calibration methods based on image plane mask replacement.

[0006] However, existing systematic error calibration methods cannot calibrate the systematic errors introduced by the morphological defects of the diffraction pinhole itself. Therefore, inventing a new systematic error calibration method is of profound research significance for promoting high-precision wavelet aberration detection of photolithography projection lenses. Summary of the Invention

[0007] To address the aforementioned technical problems in the prior art, this invention provides a system error calibration method for a phase-shifting point diffraction interferometer based on mask rotation.

[0008] A system error calibration method for a phase-shifting point diffraction interferometer based on mask rotation is proposed. The phase-shifting point diffraction interferometer includes an object plane mask module and an image plane mask module. The object plane mask module includes an object plane pinhole mask, and the image plane mask module includes an image plane pinhole-window mask and an image plane window-window mask.

[0009] The system error calibration method for the phase-shifting point diffraction interferometer based on mask rotation includes the following steps:

[0010] S1, Set the mask in the image plane mask module to the image plane pinhole-window mask to obtain the first interferogram;

[0011] S2, rotate the pinhole mask on the object surface to obtain the second interferogram, and calculate the non-rotational symmetry component in the pinhole diffraction error on the object surface based on the first and second interferograms;

[0012] S3, restore the object plane pinhole mask to its state before rotation, rotate the image plane pinhole-window mask to obtain the third interferogram, and calculate the non-rotational symmetric component in the image plane pinhole diffraction error based on the first and third interferograms;

[0013] S4, replace the image plane pinhole-window mask in the image plane mask module with the image plane window-window mask to obtain the fourth interferogram;

[0014] S5. Subtract the non-rotational symmetric components of the object plane pinhole diffraction error, the image plane pinhole diffraction error, and the remaining systematic errors from the wave aberration information carried by the first interferogram to obtain the wave aberration of the optical system under test.

[0015] Preferably, the wave aberration information carried by the first interferogram includes: object plane pinhole diffraction error, wave aberration of the optical system under test, image plane pinhole diffraction error, and other system errors;

[0016] The second interferogram carries wave aberration information including: the object plane pinhole diffraction error after rotation, the wave aberration of the optical system under test, the image plane pinhole diffraction error, and other system errors;

[0017] The wave aberration information carried by the third interferogram includes: object plane pinhole diffraction error, wave aberration of the optical system under test, image plane pinhole diffraction error after rotation, and other system errors.

[0018] The wave aberration information carried by the fourth interferogram includes: other systematic errors.

[0019] Preferably, the phase-shifting point diffraction interferometer further includes a light source module, a test optical system module, a phase-shifting grating module, and a detector module arranged from upstream to downstream of the detection optical path. The object plane mask module is located between the light source module and the test optical system module, and the image plane mask module is located between the phase-shifting grating module and the detector module.

[0020] Preferably, the object plane mask module further includes a fixed object plane alignment substrate, and the image plane mask module further includes a fixed image plane alignment substrate. Rotation alignment marks are provided on the object plane pinhole mask, the object plane alignment substrate, the image plane pinhole-window mask, and the image plane alignment substrate.

[0021] The rotation angle of the object plane pinhole mask during rotation is controlled by the rotation alignment mark on the object plane alignment substrate. The rotation angle of the image plane pinhole-window mask during rotation is also controlled by the rotation alignment mark on the image plane alignment substrate.

[0022] More preferably, the object plane pinhole mask and the image plane pinhole-window mask rotate around the z-axis when rotating, and the rotation alignment marks provided on the object plane pinhole mask, the object plane alignment substrate, the image plane pinhole-window mask, and the image plane alignment substrate are uniformly arranged along the circumferential surface perpendicular to the z-axis.

[0023] More preferably, the material of the object-to-alignment substrate and the image-to-alignment substrate is quartz glass; the material of the marking grid used for the rotation alignment mark is gold.

[0024] More preferably, the interval angle θ between adjacent rotation alignment marks in the rotation alignment marks provided on the object plane pinhole mask, the object plane alignment substrate, the image plane pinhole-window mask, and the image plane alignment substrate is 0°-90°.

[0025] In step S2, the pinhole mask on the object surface is rotated by θ around the z-axis;

[0026] In step S3, the image pinhole-window mask is rotated θ around the z-axis.

[0027] Preferably, the material of the object plane pinhole mask, the image plane pinhole-window mask, and the image plane window-window mask is a gold-plated film on the surface of a fused silica substrate.

[0028] Preferably, in step S2, the method for calculating the non-rotational symmetric component of the pinhole diffraction error of the object surface based on the first and second interferograms is as follows: using the wave aberration information carried by the first and second interferograms, the wavefront in the wave aberration information is fitted with the Zernike polynomial to obtain the n Zernike coefficients of the wavefront; then, using the orthogonality and parity-even symmetry properties of the Zernike polynomial in the unit circle domain, mathematical operations are performed on the corresponding coefficients in the Zernike coefficients to obtain the Zernike coefficients characterizing the pinhole diffraction error of the object surface.

[0029] In step S3, the method for calculating the non-rotational symmetric component of the pinhole diffraction error of the image plane based on the first and third interferograms is as follows: using the wave aberration information carried by the first and third interferograms, the wavefront in the wave aberration information is fitted with the Zernike polynomial to obtain the n Zernike coefficients of the wavefront. Then, using the orthogonality and parity-even symmetry properties of the Zernike polynomial in the unit circle domain, mathematical operations are performed on the corresponding coefficients in the Zernike coefficients to obtain the Zernike coefficients characterizing the pinhole diffraction error of the image plane.

[0030] When using Zernike polynomials to characterize wave aberrations, each term can be called a Zernike aberration.

[0031] For low-order Zernike aberrations, θ can be set to 90°, that is, the rotation operations in steps S2 and S3 are both 90° rotations. Using the mask rotation-based phase-shifting point diffraction interferometer system error calibration method, all θ terms, 2θ terms and 3θ terms in the Zernike polynomial can be calibrated.

[0032] If higher-order Zernike aberrations, such as the 4θ terms, need to be calibrated, θ can be set to 45°, meaning the rotation operations in steps S2 and S3 are both 45° rotations. Using the mask rotation-based phase-shifting point diffraction interferometer system error calibration method, all 4θ terms in the Zernike polynomial can be calibrated. The smaller the value of the interval angle θ, the higher the order of the Zernike aberrations that can be calibrated.

[0033] In this application, the lower-order Zernike aberrations refer to the θ, 2θ, and 3θ terms, while the higher-order Zernike aberrations refer to the 4θ and above terms.

[0034] Beneficial effects of this invention:

[0035] (1) The hardware structure required for the phase-shifting point diffraction interferometer system error calibration method proposed in this invention is simple. Compared with the traditional point diffraction interferometer calibration method, no additional optical modules are added, and sub-nanometer level system error calibration can be achieved.

[0036] (2) The system error calibration method of the phase-shifting point diffraction interferometer proposed in this invention precisely controls the mask rotation angle by rotating the alignment mark, so that the diffraction error caused by pinhole diffraction becomes a variable before and after rotation. The pinhole diffraction error is calibrated by utilizing the orthogonality and parity-even symmetry properties of Zernike polynomials in the unit circle domain. Compared with the conventional mask replacement method and the rotating optical system under test method, the system error is further reduced. Compared with the method of averaging the pinholes after multiple rotations, the operation complexity is reduced. Attached Figure Description

[0037] Figure 1This is a schematic diagram of the optical path structure of the system error calibration method for the phase-shifting point diffraction interferometer of the present invention.

[0038] Figure 2 This is a schematic diagram of the object plane mask module in the system error calibration method of the phase-shifting diffraction interferometer of the present invention.

[0039] Figure 3 This is a schematic diagram of the image plane mask module in the system error calibration method of the phase-shifting diffraction interferometer of the present invention.

[0040] Figure 4 This is a flowchart of the system error calibration method for the point diffraction interferometer of the present invention.

[0041] Reference numerals: Light source module 1; Object plane mask module 2; Object plane alignment substrate 21; Object plane alignment substrate alignment mark 211; Object plane pinhole mask 22; Object plane pinhole mask alignment mark 221; Object plane pinhole 222; Optical system under test module 3; Phase shift grating module 4; Image plane mask module 5; Image plane alignment substrate 51; Image plane alignment substrate alignment mark 511; Image plane pinhole-window mask 52; Image plane pinhole-window mask alignment mark 521; Image plane pinhole-window 522; Image plane window-window mask 53; Image plane window-window 531; Detector module 6. Detailed Implementation

[0042] A method for calibrating the system error of a phase-shifting point diffraction interferometer based on mask rotation is proposed. The phase-shifting point diffraction interferometer includes a light source module 1, an object plane mask module 2, a test optical system module 3, a phase-shifting grating module 4, an image plane mask module 5, and a detector module 6. Figure 1 As shown. Light source module 1 includes a light source for measurement. Optical system under test module 3 includes the optical system under test. Phase shift grating module 4 includes a phase shift grating. Detector module 6 includes a detector.

[0043] The object plane mask module 2 includes a fixed object plane alignment substrate 21 and a rotatable object plane pinhole mask 22. The image plane mask module 5 includes a fixed image plane alignment substrate 51, a rotatable image plane pinhole-window mask 52, and an image plane window-window mask 53. In both modules, the masks and alignment substrates are independent of each other. In the image plane mask module 5, the image plane pinhole-window mask 52 and the image plane alignment substrate 51 are independent but close to each other. The object plane pinhole mask 22, the image plane pinhole-window mask 52, the object plane alignment substrate 21, and the image plane alignment substrate 51 all have rotation alignment marks. In the object plane mask module 2, the object plane alignment substrate 21 is located upstream of the object plane pinhole mask 22 in the optical path and the two are close together. In the image plane mask module 5, the image plane alignment substrate 51 is located upstream of the image plane pinhole-window mask 52 and the two are close together. Precise rotation control of the two masks at any angle is achieved through the alignment marks.

[0044] like Figure 2 and Figure 3 As shown, the object-plane alignment substrate 21 has an object-plane alignment mark 211, the object-plane pinhole mask 22 has an object-plane pinhole mask alignment mark 221 and an object-plane pinhole 222, the image-plane alignment substrate 51 has an image-plane alignment mark 511, the image-plane pinhole-window mask 52 has an image-plane pinhole-window mask alignment mark 521 and an image-plane pinhole-window 522, and the image-plane window-window mask 53 has an image-plane window-window 531. The image-plane pinhole-window mask 52 and the image-plane window-window mask 53 can be used interchangeably according to the requirements of different measurement steps. In the object-plane mask module 2, the object-plane pinhole mask 22 is made of a gold film plated on a fused silica substrate, and pinholes and alignment marks are fabricated on the gold film using focused ion beam processing technology. The image-plane pinhole-window mask 52 and the image-plane window-window mask 53 have the same materials and processing technology as the object-plane pinhole mask 22 in the object-plane mask module 2.

[0045] In the object plane mask module 2 and the image plane mask module 5, the object plane alignment substrate 21 and the image plane alignment substrate 51 are made of quartz glass, and alignment marks are made using photolithography. The mark grid line material is gold.

[0046] Taking a 90° rotation as an example, the alignment marks consist of four sets of grating lines, with adjacent sets of grating lines forming a 90° angle. Rotating the mask by 90° should result in a set of grating lines coinciding with the adjacent set of grating lines before rotation. The method to precisely align the alignment marks on the mask with those on the glass substrate is as follows: Observe the mask module under a microscope. Rotate the mask until the alignment marks on the mask are substantially aligned with the alignment marks on the transparent glass substrate. If a slight angle exists between the two marks, moiré fringes will appear. Continue rotating the mask until the moiré fringes disappear and a uniform light field appears in the field of view. At this point, the alignment marks on the mask are precisely aligned with the alignment marks on the glass substrate; this is the initial state before rotation. Continue rotating the mask by 90°, using the same method to precisely align the alignment marks on the mask with another set of alignment marks on the glass substrate, thus achieving a precise 90° rotation of the mask. If the angle between adjacent gate lines is set to other angles when fabricating the object-plane aligned substrate and the image-plane aligned substrate, arbitrary angle rotation of the object-plane pinhole mask and the image-plane pinhole-window mask can be achieved.

[0047] The rotation axis z-axis of the object plane pinhole mask 22 and the image plane pinhole-window mask 52 is along the optical axis of the system.

[0048] A method for calibrating the system error of a phase-shifting point diffraction interferometer based on mask rotation, the method as follows: Figure 4 As shown, it includes the following steps:

[0049] (1) The image plane mask is set as an image plane pinhole-window mask 52. The first interferogram is obtained from the phase-shifting point diffraction interferometer. The wave aberration information carried by the first interferogram includes: object plane pinhole diffraction error, wave aberration of the optical system under test, image plane pinhole diffraction error, and other system errors. This is represented as: Where W1 represents the wave aberration information carried by the first interferogram, W... op For pinhole diffraction error on the object surface, W optic For the wavefront aberration of the optical system under test, W sys For the remaining systematic errors, W ip This represents the pinhole diffraction error of the image plane.

[0050] (2) Rotate the object plane pinhole mask 22 90° around the z-axis and obtain a second interferogram using the phase-shifting point diffraction interferometer. The wave aberration information carried by the second interferogram includes: the rotated object plane pinhole diffraction error, the wave aberration of the optical system under test, the image plane pinhole diffraction error, and other system errors. This is represented as: Among them, W2 represents the wave aberration information carried by the second interferogram. This represents the pinhole diffraction error on the rotated object surface. The non-rotationally symmetric component of the pinhole diffraction error can be calculated from the first and second interferograms.

[0051] (3) Restore the object plane pinhole mask 22 to its state before rotation, and rotate the image plane pinhole-window mask 52 90° around the z-axis to obtain the third interferogram. The wave aberration information carried by the third interferogram includes: object plane pinhole diffraction error, wave aberration of the optical system under test, image plane pinhole diffraction error after rotation, and other system errors. This is represented as: Among them, W3 represents the wave aberration information carried by the third interferogram. This represents the pinhole diffraction error of the image plane after rotation. The non-rotationally symmetric component of the pinhole diffraction error can be calculated from the first and third interferograms.

[0052] (4) Replace the image plane pinhole-window mask 52 with the image plane window-window mask 53 to obtain the fourth interferogram. The wave aberration information carried by the fourth interferogram includes: other systematic errors. Represented as: Among them, W4 represents the wave aberration information carried by the fourth interferogram.

[0053] (5) Wave aberration information carried by the first interferogram Subtract the pinhole diffraction error W from the object surface op Image plane pinhole diffraction error W ip Other systematic errors W sys The wavefront aberration W of the optical system under test can then be obtained. optic .

[0054] In step (1), the measurement light path passes through the object plane pinhole, the optical system under test, the phase shift grating, and the image plane window before reaching the detector, while the reference light path passes through the object plane pinhole, the optical system under test, the phase shift grating, and the image plane pinhole before reaching the detector.

[0055] In step (2), the measurement optical path passes through the rotated object plane pinhole, the optical system under test, the phase shift grating, and the image plane window before reaching the detector, and the reference optical path passes through the rotated object plane pinhole, the optical system under test, the phase shift grating, and the image plane pinhole before reaching the detector.

[0056] In step (3), the measurement light path passes through the object plane pinhole, the optical system under test, the phase shift grating, and the rotated image plane window before reaching the detector, and the reference light path passes through the object plane pinhole, the optical system under test, the phase shift grating, and the rotated image plane pinhole before reaching the detector.

[0057] In step (4), both the measurement optical path and the reference optical path pass through the object plane pinhole, the optical system under test, the phase shift grating, and the image plane window before reaching the detector. The difference is that the two optical paths pass through two different windows of the image plane window-window mask 53, namely two image plane windows-window 531.

[0058] The method for calculating the pinhole diffraction error of the object surface based on the first and second interferograms is as follows: From the wave aberration information carried by the first and second interferograms, we can obtain... Using Zernike polynomials to analyze wavefronts By fitting the data, the wavefront is obtained. n-term Zernike coefficients Then, utilizing the orthogonality and parity-symmetry properties of Zernike polynomials in the unit circle, for By performing mathematical operations on the coefficients of the corresponding terms, we can obtain the representation of W. op The Zernike coefficients. The method for calculating the pinhole diffraction error of the image plane based on the first and third interferograms is the same.

[0059] Taking the Z7 term in the striped Zernike polynomial as an example, in W1 The corresponding Zernike coefficient is c7. The corresponding Zernike coefficient is c8, while in W2 these two terms are expressed as The corresponding Zernike coefficient is , The corresponding Zernike coefficient is ,but

[0060] ;

[0061] .

[0062] We can obtain:

[0063] ;

[0064] .

[0065] but:

[0066] ;

[0067] .

[0068] Example 1

[0069] Taking a calibration simulation model for Zernike aberrations 17-24 as an example, in this embodiment, the rotation operation in steps S2 and S3 is a 90° rotation. The wavefront to be measured is generated using the known actual values ​​of the Zernike coefficients, and the measured values ​​of the Zernike coefficients are obtained by using the wavefront information measured before and after the rotation.

[0070] Table 1 Measurement results of the Zernike aberration calibration simulation model

[0071]

[0072] In this embodiment, the simulation measurement results of the Zernike coefficients are shown in Table 1. The wavefront aberration RMS of the wavefront under test is 14.14 nm. With the addition of random Gaussian noise with a standard deviation of 1 nm, the overall relative error of the Zernike coefficient measurement is less than 3%.

Claims

1. A system error calibration method for a phase-shifting point diffraction interferometer based on mask rotation. The phase-shifting point diffraction interferometer includes an object plane mask module and an image plane mask module. The object plane mask module includes an object plane pinhole mask, and the image plane mask module includes an image plane pinhole-window mask and an image plane window-window mask. characterized in that The system error calibration method for the phase-shifting point diffraction interferometer based on mask rotation includes the following steps: S1, set the mask in the image plane mask module to an image plane pinhole-window mask to obtain the first interferogram; the wave aberration information carried by the first interferogram includes: object plane pinhole diffraction error, wave aberration of the optical system under test, image plane pinhole diffraction error, and other system errors; S2, rotate the object surface pinhole mask to obtain the second interferogram. Calculate the non-rotational symmetric component of the object surface pinhole diffraction error based on the first and second interferograms. The wave aberration information carried by the second interferogram includes: the rotated object surface pinhole diffraction error, the wave aberration of the optical system under test, the image surface pinhole diffraction error, and other system errors. S3. Restore the object plane pinhole mask to its state before rotation, rotate the image plane pinhole-window mask to obtain the third interferogram, and calculate the non-rotational symmetric component of the image plane pinhole diffraction error based on the first and third interferograms; the wave aberration information carried by the third interferogram includes: object plane pinhole diffraction error, wave aberration of the optical system under test, image plane pinhole diffraction error after rotation, and other system errors; S4, replace the image plane pinhole-window mask in the image plane mask module with the image plane window-window mask to obtain the fourth interferogram; the wave aberration information carried by the fourth interferogram includes: other systematic errors; S5. Subtract the non-rotational symmetric components of the object plane pinhole diffraction error, the image plane pinhole diffraction error, and the remaining systematic errors from the wave aberration information carried by the first interferogram to obtain the wave aberration of the optical system under test.

2. The method according to claim 1, wherein, The phase-shifting point diffraction interferometer also includes a light source module, a test optical system module, a phase-shifting grating module, and a detector module arranged from upstream to downstream of the detection optical path. The object plane mask module is located between the light source module and the test optical system module, and the image plane mask module is located between the phase-shifting grating module and the detector module.

3. The system error calibration method for a phase-shifting point diffraction interferometer based on mask rotation according to claim 1, characterized in that, The object plane mask module also includes a fixed object plane alignment substrate, and the image plane mask module also includes a fixed image plane alignment substrate. Rotation alignment marks are provided on the object plane pinhole mask, the object plane alignment substrate, the image plane pinhole-window mask, and the image plane alignment substrate. The rotation angle of the object plane pinhole mask during rotation is controlled by the rotation alignment mark on the object plane alignment substrate. The rotation angle of the image plane pinhole-window mask during rotation is also controlled by the rotation alignment mark on the image plane alignment substrate.

4. The system error calibration method for a phase-shifting point diffraction interferometer based on mask rotation according to claim 3, characterized in that, When the object plane pinhole mask and the image plane pinhole-window mask rotate, they rotate around the z-axis. The rotation alignment marks set on the object plane pinhole mask, the object plane alignment substrate, the image plane pinhole-window mask, and the image plane alignment substrate are uniformly arranged along the circumferential surface perpendicular to the z-axis.

5. The system error calibration method for a phase-shifting point diffraction interferometer based on mask rotation according to claim 4, characterized in that, The materials of the object-plane alignment substrate and the image-plane alignment substrate are quartz glass; the material of the marking grid used for the rotation alignment marks is gold.

6. The system error calibration method for a phase-shifting point diffraction interferometer based on mask rotation according to claim 4, characterized in that, The interval angle θ between adjacent rotation alignment marks on the object plane pinhole mask, object plane alignment substrate, image plane pinhole-window mask, and image plane alignment substrate is 0°-90°. In step S2, the pinhole mask on the object surface is rotated by θ around the z-axis; In step S3, the image pinhole-window mask is rotated θ around the z-axis.

7. The system error calibration method for a phase-shifting point diffraction interferometer based on mask rotation according to claim 1, characterized in that, The material for the object plane pinhole mask, the image plane pinhole-window mask, and the image plane window-window mask is a gold-plated film on the surface of a fused silica substrate.

8. The system error calibration method for a phase-shifting point diffraction interferometer based on mask rotation according to claim 1, characterized in that, In step S2, the method for calculating the non-rotational symmetric component of the pinhole diffraction error of the object surface based on the first and second interferograms is as follows: using the wave aberration information carried by the first and second interferograms, the wavefront in the wave aberration information is fitted with the Zernike polynomial to obtain the n Zernike coefficients of the wavefront. Then, using the orthogonality and parity-even symmetry properties of the Zernike polynomial in the unit circle domain, mathematical operations are performed on the corresponding coefficients in the Zernike coefficients to obtain the Zernike coefficients characterizing the pinhole diffraction error of the object surface.

9. The system error calibration method for a phase-shifting point diffraction interferometer based on mask rotation according to claim 1, characterized in that, In step S3, the method for calculating the non-rotational symmetric component of the pinhole diffraction error of the image plane based on the first and third interferograms is as follows: using the wave aberration information carried by the first and third interferograms, the wavefront in the wave aberration information is fitted with the Zernike polynomial to obtain the n Zernike coefficients of the wavefront. Then, using the orthogonality and parity-even symmetry properties of the Zernike polynomial in the unit circle domain, mathematical operations are performed on the corresponding coefficients in the Zernike coefficients to obtain the Zernike coefficients characterizing the pinhole diffraction error of the image plane.

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