Laue mirror interference photoetching system and photoetching method based on collimated flat-topped light

Abstract

The embodiment of the invention relates to the technical field of micro-nano structure photoetching, and discloses a Laue mirror interference photoetching system and photoetching method based on collimated flat-topped light. The photoetching system comprises a laser device, a spatial filter, a polarization type continuous variable light attenuation system, a beam shaping system and a Laue mirror interference system which are sequentially arranged at intervals in the light path transmission direction, and laser generated by the laser device enters the polarization type continuous variable light attenuation system after passing through the spatial filter; the polarization type continuously adjustable light attenuation system is used for continuously and adjustably attenuating the intensity of the laser; the light beam shaping system is used for shaping and converting the laser beam output by the polarization type continuous adjustable light attenuation system into collimated flat-topped light; the Laue mirror interference system carries out interference processing on the straight flat-topped light and generates interference fringes on the sample stage. Through the mode, the grating duty ratio uniformity and efficiency of the interference photoetching technology can be improved, the complexity of a photoetching system can be reduced through Laue mirror single-beam interference photoetching, and the reliability is improved.

Description

Technical Field

[0001] This invention relates to the field of micro-nano structure lithography technology, specifically to a Laue mirror interference lithography system and lithography method based on collimated flat-top light. Background Technology

[0002] In the semiconductor field, gratings are not only functional devices, but also core tools and key measurement structures in the manufacturing process. The ability to manufacture uniform periodic grating structures over large areas is one of the key indicators for measuring core competitiveness in micro-nano fabrication, advanced optics, and semiconductor technologies, and it has foundational significance for promoting the development of cutting-edge fields such as information technology, artificial intelligence, and quantum technology.

[0003] In existing technologies, dual-beam laser interferometry (DLI) systems or Laue mirror interferometry systems are generally used to fabricate gratings. DLI systems use a beam splitter to divide a single laser beam into two beams, which are then guided by a mirror or lens system to converge and interfere at a specific angle on the sample surface. DLI systems are efficient and do not require costly or complex mask fabrication. However, the energy intensity distribution of the laser source in a DLI system exhibits a Gaussian distribution, gradually decreasing from the center towards the beam profile. This results in uneven exposure dose distribution between the two laser beams on the sample surface, leading to uneven duty cycles in the periodic micro / nano structures on the sample. To address this issue, some methods directly cover and irradiate the sample surface with only the central region of the interferometric laser beam. This can mitigate the Gaussian distribution problem to some extent, but this method results in low laser energy utilization, leading to reduced lithography efficiency. Furthermore, DLI systems require precise adjustment of the optical paths of the two beams to ensure equal optical path lengths, coplanarity, and alignment with the sample surface, a complex and time-consuming process. The dual-beam laser interferometry system also includes multiple independent optical components such as beam splitters and mirrors. It is very sensitive to vibration and airflow and requires an expensive vibration isolation platform.

[0004] The Laue mirror interferometer system involves directly illuminating a laser beam onto a mirror placed perpendicular to the sample stage. The incident beam and the beam reflected by the reflector interfere on the sample surface. However, the Laue mirror interferometer system also suffers from optical field inhomogeneity. Due to the Gaussian intensity distribution of the ultraviolet laser source, the exposure energy received at different locations on the sample is uneven, with the energy intensity decreasing from the interface between the mirror and the sample towards the far end, resulting in an uneven duty cycle of the grating on the sample. Summary of the Invention

[0005] In view of the above problems, embodiments of the present invention provide a Laue mirror interference lithography system and lithography method based on collimated flat-top light to solve the problems existing in the prior art.

[0006] According to one aspect of the present invention, a Laue mirror interference lithography system based on collimated flat-top light is provided. The Laue mirror interference lithography system based on collimated flat-top light includes, along the optical path transmission direction, a laser, a spatial filter, a continuously tunable polarization attenuation system, a beam shaping system, and a Laue mirror interference system arranged sequentially at intervals. The laser generated by the laser passes through the spatial filter and then enters the continuously tunable polarization attenuation system. The laser has a Gaussian distribution. The polarization-type continuously adjustable optical attenuation system is used to continuously and tunably attenuate the intensity of the laser. The beam shaping system is used to shape the laser beam output from the polarization-type continuously adjustable optical attenuation system into collimated flat-top light. The Laue mirror interference system includes a base and a Laue mirror and a sample stage disposed on the base. The Laue mirror and the sample stage are at a preset angle. The collimated flat-top light emitted from the beam shaping system is incident on the Laue mirror to perform interference processing on the collimated flat-top light and generate interference fringes on the sample stage.

[0007] In one alternative embodiment, the polarization-type continuously adjustable optical attenuation system includes a half-wave plate, a first polarizing beam splitter, and a second polarizing beam splitter arranged at intervals. The half-wave plate, the first polarizing beam splitter, and the second polarizing beam splitter are arranged perpendicularly in an L-shape. The plane of the half-wave plate is perpendicular to the optical axis of the laser. The incident end face of the first polarizing beam splitter faces and is perpendicular to the beam from the half-wave plate. The incident end face of the second polarizing beam splitter faces and is perpendicular to the vertically polarized light from the first polarizing beam splitter.

[0008] In one optional embodiment, the polarization-type continuously adjustable optical attenuation system further includes a first beam collector and a second beam collector. The first beam collector is located at the side exit port of the first polarization beam splitter and is used to absorb the parallel polarized light that is split and overflowed by the first polarization beam splitter. The second beam collector is located at the side exit port of the second polarization beam splitter and is used to absorb the parallel polarized light that is split and overflowed by the second polarization beam splitter.

[0009] In one alternative embodiment, the beam shaping system includes a refractive field mapping beam shaper spaced apart and at least one beam expanding and collimating subsystem. The beam expanding and collimating subsystem is located at the input or output end of the refractive field mapping beam shaper and is used to expand the input laser beam. The refractive field mapping beam shaper is used to shape the laser beam into the collimated flat-top light.

[0010] In one alternative embodiment, the beam expanding and collimating subsystem comprises two subsystems: one subsystem is located at the incident end of the refractive field mapping beam shaper, and the other subsystem is located at the exit end of the refractive field mapping beam shaper.

[0011] In one alternative embodiment, the refractive field mapping beam shaper includes a first aspherical lens and a second aspherical lens spaced apart. The laser beam expanded by the beam expanding and collimating subsystem at the incident end is introduced with aberrations by the first aspherical lens, and then compensated by the second aspherical lens, so as to shape the expanded laser beam into the collimated flat-top light. The beam expanding and collimating subsystem includes beam expanding lenses and collimating lenses arranged at intervals.

[0012] In one alternative embodiment, the beam shaping system further includes a mechanical fixing frame, on which fixing portions for fixing the beam expanding lens, the collimating lens, the first aspherical lens, and the second aspherical lens are sequentially provided.

[0013] In one alternative, the Laue mirror is fixed at a 90-degree angle to the sample stage.

[0014] According to another aspect of the present invention, a photolithography method is provided, the photolithography method being based on the above-described Laue mirror interference photolithography system based on collimated flat-top light.

[0015] In one alternative approach, the period of the interference fringes is controlled by adjusting the angle between the Laue mirror and the sample stage by rotating the base.

[0016] This invention discloses a Laue mirror interference lithography system based on collimated flat-top light. The beam shaping system transforms the Gaussian laser beam into collimated flat-top light to improve the uniformity of the grating duty cycle on the sample, thereby increasing the precision of the components manufactured by this interference lithography system. This solves the problems of low grating duty cycle uniformity and low lithography efficiency in interference lithography technology. Furthermore, unlike dual-beam or multi-beam interference lithography systems, this invention uses single-beam interference lithography, resulting in fewer optical components, a more stable optical path, and significantly reduced system component count. This not only reduces the overall complexity of the interference lithography system but also greatly reduces the sensitivity of the optical system to external disturbances such as airflow and vibration. In addition, since the reflected beam originates from the incident beam, the two beams automatically satisfy the coherence condition (i.e., same frequency and polarization direction), eliminating the need for cumbersome calibration and ensuring natural stability.

[0017] The above description is merely an overview of the technical solutions of the embodiments of the present invention. In order to better understand the technical means of the embodiments of the present invention and to implement them in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the embodiments of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0018] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A schematic diagram of the structure of the Laue mirror interference lithography system based on collimated flat-top light provided in an embodiment of the present invention is shown. Detailed Implementation

[0019] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0020] Figure 1 A schematic diagram of the structure of the Laue mirror interference lithography system based on collimated flat-top light provided in an embodiment of the present invention is shown, as follows: Figure 1 As shown, the Laue mirror interference lithography system based on collimated flat-top light includes, along the optical path transmission direction, a laser 1, a spatial filter 2, a continuously adjustable polarization attenuation system 8, a beam shaping system 14, and a Laue mirror interference system 17, arranged sequentially at intervals. Laser 1 generates ultraviolet laser light. After passing through the spatial filter 2, the laser beam exhibits a Gaussian distribution. The laser beam generated by laser 1 is perpendicular to the planes of the spatial filter 2 and the half-wave plate 3. The spatial filter 2 is the core purification element, which can be composed of a microscope objective and a pinhole, used to filter out high-frequency noise and non-fundamental mode components in the laser beam, obtaining a near-ideal Gaussian beam wave. Subsequently, the laser enters the continuously adjustable polarization attenuation system 8, which continuously and tunably attenuates the intensity of the laser beam.

[0021] Preferably, in one embodiment, the polarization-type continuously adjustable light attenuation system 8 includes a half-wave plate 3, a first polarizing beam splitter 4, and a second polarizing beam splitter 6 arranged at intervals. The half-wave plate 3, the first polarizing beam splitter 4, and the second polarizing beam splitter 6 are arranged vertically in an L-shape. The plane of the half-wave plate 3 is perpendicular to the optical axis of the laser. The incident end face of the first polarizing beam splitter 4 is directly opposite to and perpendicular to the light beam from the half-wave plate 3. The incident end face of the second polarizing beam splitter 6 is directly opposite to and perpendicular to the vertically polarized light from the first polarizing beam splitter prism.

[0022] Among them, the half-wave plate 3 acts as a polarization state adjuster. The beam is incident perpendicularly, and by rotating its angle around the optical axis, the linear polarization direction of the output beam can be changed, thereby continuously and steplessly adjusting the polarization component ratio of the subsequent polarization beam splitter and realizing continuously adjustable laser intensity control.

[0023] Both the first polarizing beam splitter prism 4 and the second polarizing beam splitter 6 have cubic beam-splitting surfaces inside, which are PBS-coated interfaces. The first polarizing beam splitter prism 4 separates the incident light into two orthogonal linearly polarized beams according to the polarization direction. The P-polarized light (parallel to the incident surface) is completely transmitted, while the S-polarized light (perpendicular to the incident surface) is reflected at a 45-degree angle. The second polarizing beam splitter prism 6 further separates the S-polarized light into two orthogonal linearly polarized beams according to the polarization direction. The S-polarized light emitted from the second polarizing beam splitter prism 6 enters the beam shaping system 14.

[0024] When the half-wave plate 3 is rotated, the polarization direction of the beam incident on the first polarizing beam splitter 4 changes continuously. According to Malus's law, the transmitted light intensity I = I0 * cos²θ (θ is the angle between the polarization direction and the transmission axis) is calculated. When θ = 0°, the transmittance is at its maximum (reaching 100%); when θ = 90°, the transmittance is 0. Therefore, by rotating the half-wave plate, the transmitted light intensity passing through the first polarizing beam splitter 4 can be continuously and steplessly adjusted, achieving arbitrary changes or attenuation of the light intensity from near 0 to its maximum value.

[0025] The polarization-type continuously adjustable light attenuation system 8 changes the polarization direction of the incident light by adjusting the half-wave plate 3. Then, by utilizing the beam splitting characteristics of the polarization beam splitter, the light intensity entering the subsequent main optical path can be continuously and precisely controlled. This enables precise control of light intensity and exposure dose, achieving stable interference fringe contrast and precise control of lithography exposure dose.

[0026] The polarization-type continuously adjustable optical attenuation system 8 of this embodiment has the advantages of no moving parts, optical path collimation, and relatively low cost. The absence of moving parts can improve reliability, and the optical path collimation can ensure that the quality of subsequent beams is not affected.

[0027] In other embodiments, the polarization-type continuously adjustable optical attenuation system 8 may also employ a rotating attenuator or an electro-optic modulator scheme, which is not limited here.

[0028] Furthermore, such as Figure 1 As shown, the polarization-type continuously adjustable light attenuation system also includes a first beam collector 5 and a second beam collector 7. The first beam collector 5 is located at the side exit port of the first polarization beam splitter 4 and is used to absorb the parallel polarized light that is split and overflowed by the first polarization beam splitter 4. The second beam collector 7 is located at the side exit port of the second polarization beam splitter 6 and is used to absorb the parallel polarized light that is split and overflowed by the second polarization beam splitter 6.

[0029] In this embodiment, the unwanted polarization component beams separated by the first polarization beam splitter 4 and the second polarization beam splitter 6 are not simply blocked, but are guided to a dedicated beam collector for absorption. This removes stray light that does not participate in interference, avoids its reflection and scattering in the optical path to form noise, significantly improves the signal-to-noise ratio of the system, ensures the performance of the optical system, and at the same time, the safe absorption of ultraviolet light also protects the operators.

[0030] The beam shaping system 14 is used to shape the laser beam output from the polarization-type continuously adjustable optical attenuation system 8 into a collimated flat-top beam. The beam shaping system 14 is used to homogenize and collimate the Gaussian-distributed and divergent beam before interference lithography, converting it into a collimated plane wave with uniform intensity and flat phase, ensuring that the final beam used for interference has both a flat-top distribution and sufficient collimation, thereby improving the quality of the lithographic pattern.

[0031] Preferably, in one embodiment, the beam shaping system 14 includes refractive field mapping beam shapers 11 spaced apart and at least one beam expanding and collimating subsystem. The beam expanding and collimating subsystem is located at the input or output end of the refractive field mapping beam shaper and is used to expand the input laser beam. The refractive field mapping beam shaper 11 is used to shape the laser beam into a collimated flat-top beam. The refractive field mapping beam shaper 11 improves the uniformity of the grating duty cycle on the sample by shaping the Gaussian laser beam into a collimated flat-top beam, thereby improving the precision of the components manufactured by the interference lithography system and solving the problems of low grating duty cycle uniformity and low lithography efficiency in interference lithography technology.

[0032] The beam shaping system 14 in this embodiment may include one beam expanding and collimating subsystem, or two or more beam expanding and collimating subsystems, which can expand the beam to the size of the area to be exposed. This embodiment utilizes the beam shaping system 14 to convert a Gaussian-distributed laser beam into a collimated beam that meets the required exposure area, resulting in more uniform linewidth and grating duty cycle in the micro / nano periodic structures fabricated by interference lithography.

[0033] Preferably, the beam expansion and collimation subsystem comprises two components, such as... Figure 1 As shown, one beam expanding and collimating subsystem is located at the incident end of the refractive field mapping beam shaper 11, and another beam expanding and collimating subsystem is located at the exit end of the refractive field mapping beam shaper. The beam expanding and collimating subsystem at the incident end initially expands the diameter of the laser beam and reduces the divergence angle, while the beam expanding and collimating subsystem at the exit end further expands the diameter of the collimated flat-top beam after being shaped by the refractive field mapping beam shaper 11 to the size required for sample exposure, ensuring that the illumination area is sufficiently large and uniform.

[0034] The beam expanding and collimating subsystem includes beam expanding lenses and collimating lenses arranged at intervals, such as... Figure 1 As shown, the beam expanding and collimating subsystem at the incident end includes a beam expanding lens 9 and a collimating lens 10, while the beam expanding and collimating subsystem at the exit end includes a beam expanding lens 12 and a collimating lens 13. The beam expanding lens enlarges the diameter of the beam while reducing the divergence angle of the beam, while the collimating lens converts the enlarged beam (divergent beam) into a parallel beam, allowing the light rays to propagate parallel to each other without diffusion.

[0035] Furthermore, in one embodiment, the refractive field mapping beam shaper 11 includes a first aspherical lens and a second aspherical lens arranged at intervals. The laser beam expanded by the beam expanding and collimating subsystem at the incident end is introduced with aberrations by the first aspherical lens to modulate the wavefront, and then compensated and collimated by the second aspherical lens to shape the expanded laser beam into a collimated flat-top beam. The final output is a collimated flat-top beam with uniform energy distribution and a flat wavefront.

[0036] In other embodiments, the refractive field mapping beam shaper 11 may also employ other structures, such as diffractive optical elements, to efficiently convert a Gaussian beam into a uniform flat-top beam.

[0037] Furthermore, the beam shaping system also includes a mechanical fixing frame, on which are sequentially provided fixing parts for fixing the beam expanding lens, collimating lens, first aspherical lens, and second aspherical lens. Since the beam expanding lens, collimating lens, first aspherical lens, and second aspherical lens all require precise adjustment, this embodiment, by setting up a mechanical fixing frame and providing corresponding fixing parts on it to fix each lens, greatly reduces the difficulty, error, and time of adjusting discrete components one by one, reduces optical path adjustment errors, improves reliability and accuracy, and further simplifies the interference lithography system.

[0038] The Laue mirror interference system 17 includes a base 16 and a Laue mirror 15 and a sample stage disposed on the base 16. A substrate with photoresist spin-coated on its surface is placed on the sample stage. The Laue mirror 15 and the sample stage are at a preset angle. The collimated flat-top light emitted from the beam shaping system 14 is incident on the Laue mirror 15 to perform interference processing on the collimated flat-top light and generate interference fringes on the sample stage.

[0039] The Laue mirror 15 is fixed at a 90-degree angle to the sample stage.

[0040] Unlike dual-beam or multi-beam interference lithography systems, this embodiment uses single-beam interference lithography with Laue mirrors. This reduces the number of optical components and ensures a stable optical path, significantly decreasing the overall system complexity and reducing its sensitivity to external disturbances such as airflow and vibration. Furthermore, because the reflected beam originates from the incident beam and the two beams automatically meet the coherence condition (i.e., they have the same frequency and polarization direction), no cumbersome calibration is required, resulting in natural stability.

[0041] This embodiment employs a polarization-type continuously adjustable optical attenuation system, a beam shaping system, and a Laue mirror interference system to construct an interference lithography system. It is not simply a stacking of optical components. The adjustable attenuation system, composed of a half-wave plate and two-stage polarization beam splitters, enables wide-range, high-precision, and mechanically motion-free intensity adjustment without altering the laser's operating state (to protect laser lifetime and mode stability). Its stable Gaussian output beam is the ideal input for the subsequent refractive field mapping beam shaper, achieving the conversion from Gaussian light to flat-top light. The large-size, uniform collimated flat-top beam obtained after shaping is a key prerequisite for obtaining large-area, highly uniform interference fringes. Using this beam as the incident beam for Laue mirror interference, these three systems form a tightly linked and mutually supportive golden combination, jointly solving the core challenges of beam quality, exposure uniformity, and process controllability in interference lithography. This interference lithography system allows for the simple and efficient fabrication of high-precision, large-area periodic micro / nano structures with uniform and clear grating patterns.

[0042] The present invention also provides a photolithography method based on the above-described collimated flat-top light-based Laue mirror interference photolithography system.

[0043] Furthermore, the base is a rotatable and adjustable base. By rotating and adjusting the base, the angle between the Laue mirror and the sample stage can be adjusted to control the period of the interference fringes, thereby adjusting the spacing of the interference pattern.

[0044] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0045] Similarly, it should be understood that, in order to streamline the invention and aid in understanding one or more of the various aspects of the invention, features of the embodiments of the invention are sometimes grouped together in a single embodiment, figure, or description thereof in the above description of exemplary embodiments of the invention. However, this disclosure should not be construed as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim.

[0046] Those skilled in the art will understand that modules in the computer device of the embodiments can be adaptively modified and placed in one or more computer devices different from that embodiment. Modules, units, or components in the embodiments can be combined into a single module, unit, or component, and can be divided into multiple sub-modules, sub-units, or sub-components. Except where at least some of such features and / or processes or units are mutually exclusive, any combination can be used to combine all features disclosed in this specification (including the accompanying claims, abstract, and drawings) and all processes or units of any method or computer device so disclosed. Unless expressly stated otherwise, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) may be replaced by an alternative feature that serves the same, equivalent, or similar purpose.

[0047] It should be noted that the above embodiments are illustrative of the invention and not restrictive, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention can be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third, etc., does not indicate any order. These words can be interpreted as names. The steps in the above embodiments, unless otherwise specified, should not be construed as limiting the order of execution.

Claims

1. A Laue mirror interference lithography system based on collimated flat-top light, characterized in that, The Laue mirror interference lithography system based on collimated flat-top light includes a laser, a spatial filter, a continuously tunable polarization attenuation system, a beam shaping system, and a Laue mirror interference system arranged sequentially along the optical path transmission direction. The laser generated by the laser passes through the spatial filter and then enters the continuously tunable polarization attenuation system. The laser has a Gaussian distribution. The polarization-type continuously adjustable optical attenuation system is used to continuously and tunably attenuate the intensity of the laser. The beam shaping system is used to shape the laser beam output from the polarization-type continuously adjustable optical attenuation system into collimated flat-top light. The Laue mirror interference system includes a base and a Laue mirror and a sample stage disposed on the base. The Laue mirror and the sample stage are at a preset angle. The collimated flat-top light emitted from the beam shaping system is incident on the Laue mirror to perform interference processing on the collimated flat-top light and generate interference fringes on the sample stage.

2. The Laue mirror interference lithography system based on collimated flat-top light according to claim 1, characterized in that, The polarization-type continuously adjustable optical attenuation system includes a half-wave plate, a first polarizing beam splitter, and a second polarizing beam splitter arranged at intervals. The half-wave plate, the first polarizing beam splitter, and the second polarizing beam splitter are arranged perpendicularly in an L-shape. The plane of the half-wave plate is perpendicular to the optical axis of the laser. The incident end face of the first polarizing beam splitter is directly opposite to and perpendicular to the beam from the half-wave plate. The incident end face of the second polarizing beam splitter is directly opposite to and perpendicular to the vertically polarized light from the first polarizing beam splitter.

3. The Laue mirror interference lithography system based on collimated flat-top light according to claim 2, characterized in that, The polarization-type continuously adjustable light attenuation system further includes a first beam collector and a second beam collector. The first beam collector is located at the side exit port of the first polarization beam splitter and is used to absorb the parallel polarized light that is split and overflowed by the first polarization beam splitter. The second beam collector is located at the side exit port of the second polarization beam splitter and is used to absorb the parallel polarized light that is split and overflowed by the second polarization beam splitter.

4. The Laue mirror interference lithography system based on collimated flat-top light according to claim 1, characterized in that, The beam shaping system includes a refractive field mapping beam shaper spaced apart and at least one beam expanding and collimating subsystem. The beam expanding and collimating subsystem is located at the input or output end of the refractive field mapping beam shaper and is used to expand the input laser beam. The refractive field mapping beam shaper is used to shape the laser beam into the collimated flat-top light.

5. The Laue mirror interference lithography system based on collimated flat-top light according to claim 4, characterized in that, The beam expanding and collimating subsystem comprises two subsystems: one subsystem is located at the incident end of the refractive field mapping beam shaper, and the other subsystem is located at the exit end of the refractive field mapping beam shaper.

6. The Laue mirror interference lithography system based on collimated flat-top light according to claim 5, characterized in that, The refractive field mapping beam shaper includes a first aspherical lens and a second aspherical lens arranged at intervals. The laser beam expanded by the beam expanding and collimating subsystem at the incident end is introduced with aberrations by the first aspherical lens, and then compensated by the second aspherical lens, so as to shape the expanded laser beam into the collimated flat-top light. The beam expanding and collimating subsystem includes beam expanding lenses and collimating lenses arranged at intervals.

7. The Laue mirror interference lithography system based on collimated flat-top light according to claim 6, characterized in that, The beam shaping system further includes a mechanical fixing frame, on which fixing parts for fixing the beam expanding lens, the collimating lens, the first aspherical lens and the second aspherical lens are provided in sequence.

8. The Laue mirror interference lithography system based on collimated flat-top light according to claim 1, characterized in that, The Laue mirror is fixed at a 90-degree angle to the sample stage.

9. A photolithography method, characterized in that, The photolithography method is based on the Laue mirror interference photolithography system based on collimated flat-top light as described in any one of claims 1-8.

10. The photolithography method according to claim 9, characterized in that, The period of the interference fringes can be controlled by adjusting the angle between the Laue mirror and the sample stage by rotating and adjusting the base.

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