Lithography calibration apparatus, method and lithography system for a lithography system

Abstract

The application relates to a photoetching calibration device, a photoetching calibration method and a photoetching system for the photoetching system, wherein the photoetching calibration method comprises the following steps: a calibration objective lens collimates a first scattered light beam into a calibration collimated light beam; wherein a projection objective lens converges a to-be-modulated light beam emitted by a light source on a scattering medium, the to-be-modulated light beam is scattered into the first scattered light beam through the scattering medium; the distance between the calibration objective lens and the scattering medium is a preset focusing distance; a calibration converging lens converges the received calibration collimated light beam into a calibration light beam; a calibration camera receives the calibration light beam and takes a picture to obtain a calibration image; a calibration controller generates a scattering medium transmission matrix according to the calibration image, and calibrates the photoetching system based on the scattering medium transmission matrix. Through the application, the problem of how to reduce the production cost while ensuring that the photoetching pattern meets the high-precision requirement is solved, and the photoetching effect with low cost and high resolution is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of photolithography technology, and in particular to a photolithography calibration device, a method and a photolithography system for a photolithography system. BACKGROUND

[0002] Photolithography technology is one of the key processes in the fields of semiconductor manufacturing, micro-nano processing, etc., and its core is to form a micro and fine pattern on a material surface by precisely controlling the shape, size and position of a light beam.

[0003] In related technologies, photolithography technology often adopts laser direct writing or projection photolithography. Laser direct writing photolithography directly scans a material surface by a laser beam to form a required pattern, but this way has certain limitations in beam control, pattern precision and efficiency, especially when a projection objective with a small numerical aperture (NA) is used, the resolution is often limited; projection photolithography projects a pattern on a mask onto a material surface through a projection objective, which improves the precision and efficiency of the pattern, but has high system complexity and high cost.

[0004] At present, there is no effective solution to the problem of how to reduce the production cost of photolithography while ensuring that the photolithography pattern meets the high precision requirement in related technologies. SUMMARY

[0005] Embodiments of the present application provide a photolithography calibration device, a method and a photolithography system for a photolithography system to at least solve the problem of how to reduce the production cost of photolithography while ensuring that the photolithography pattern meets the high precision requirement in related technologies.

[0006] In a first aspect, an embodiment of the present application provides a photolithography calibration device for a photolithography system, the photolithography system comprising: a light source, a projection objective and a scattering medium; the photolithography calibration device comprising:

[0007] a calibration objective, configured to collimate a first scattered light beam into a calibration collimated light beam; wherein the first scattered light beam is generated by converging a modulated light beam emitted by the light source on the scattering medium by the projection objective, and scattering the modulated light beam by the scattering medium; a distance between the calibration objective and the scattering medium is determined based on a distance between a wafer to be photolithographed and the scattering medium;

[0008] a calibration converging lens, configured to converge the received calibration collimated light beam into a calibration light beam;

[0009] a calibration camera, configured to receive the calibration light beam and take a picture to obtain a calibration image;

[0010] a calibration controller, configured to calibrate the photolithography system according to the calibration image.

[0011] In some embodiments, the calibration controller is further configured to extract calibration light intensity data and calibration amplitude of the calibration light beam based on the calibration image, input the calibration light intensity data and the calibration amplitude into a parameter optimization model, and generate a scattering medium transmission matrix using the parameter optimization model;

[0012] The calibration controller is further configured to calibrate the lithography system using the scattering medium transmission matrix.

[0013] In some embodiments, the system further comprises a micro-mirror group.

[0014] The calibration controller is further configured to obtain target light intensity data of a lithography image to be generated, and obtain target image data based on the target light intensity data and the scattering medium transmission matrix.

[0015] The calibration controller is further configured to instruct each micro-mirror in the micro-mirror group to calibrate and deflect to a specified angle based on the target image data.

[0016] In a second aspect, embodiments of the present application provide a lithography system, comprising a light source, a projection objective, a scattering medium, a micro-mirror group, and a lithography calibration device as described in the first aspect above.

[0017] The micro-mirror group comprises a plurality of micro-mirrors, each of which deflects to a specified angle in response to the calibration image, wherein the calibration image is generated by the lithography calibration device.

[0018] Each of the micro-mirrors modulates a lithography light beam of the light source into an incident light beam at the specified angle.

[0019] The projection objective converges the incident light beam on the scattering medium, and scatters the incident light beam into a second scattered light beam through the scattering medium.

[0020] The second scattered light beam forms a lithography image on a wafer to be lithographed.

[0021] In some embodiments, the lithography system comprises:

[0022] A converging lens is configured to converge a modulated light beam modulated by the micro-mirror to an aperture stop, and the aperture stop is configured to screen the modulated light beam to generate a screened light beam.

[0023] A collimating lens is configured to collimate the screened light beam into the incident light beam.

[0024] In some embodiments, the system further comprises a lithography controller and a wafer stage.

[0025] The wafer carrier is used to fix the position of the wafer to be photolithographed;

[0026] The photolithography controller is used to indicate the wafer carrier to drive the wafer to be photolithographed to translate based on the obtained moving direction when the second scattered light beam is used for photolithography processing, and generate the photolithography image.

[0027] In some embodiments, the photolithography controller is further used to obtain the target image data generated by the calibration controller;

[0028] The photolithography controller is further used to obtain real-time photolithography information of the wafer to be photolithographed;

[0029] The photolithography controller determines the moving direction based on the real-time photolithography information and the target image data.

[0030] In some embodiments, the system further comprises an energy control module, a beam stabilizing component, a beam expanding module and a beam shaping module;

[0031] The energy control module is used to obtain part of the beam energy of the photolithography light beam based on a preset fixed ratio, calculate the energy stability of the photolithography light beam based on the part of the beam energy, and adjust the light source based on the energy stability.

[0032] The beam stabilizing component comprises a plurality of beam stabilizing reflectors; each of the beam stabilizing reflectors is deflected to a specified beam stabilizing angle;

[0033] Each of the beam stabilizing reflectors reflects the photolithography light beam to a pointing stable light beam at the specified beam stabilizing angle.

[0034] The beam expanding module is used to expand the pointing stable light beam to a beam expanding light beam based on a preset expansion multiple.

[0035] The beam shaping module is used to shape the beam expanding light beam into a flat-top light beam, and reflect the flat-top light beam to the micro mirror group.

[0036] In some embodiments, the system further comprises a focusing light source and a focusing judge;

[0037] The focusing light source is used to emit a focusing laser to the center of the photolithography region, the focusing laser is reflected by the wafer to be photolithographed to the focusing judge, and a focusing light spot is generated on the surface of the focusing judge; wherein the center of the photolithography region is located on the upper surface of the wafer to be photolithographed irradiated by the photolithography light beam.

[0038] The focus judging device is configured to record a focus spot position of the focus spot, generate a focus result based on the focus spot position, and move the wafer to be photolithographed based on the focus result, so as to adjust a distance between an upper surface of the wafer to be photolithographed and the scattering medium to a preset focus distance.

[0039] In a third aspect, an embodiment of the present application provides a photolithography calibration method for a photolithography system, the photolithography system comprising a light source, a projection objective, and a scattering medium, and the method comprising:

[0040] The calibration objective collimates the first scattered light beam into a calibration collimated light beam; wherein the projection objective converges a to-be-modulated light beam emitted by the light source on the scattering medium, and the scattering medium scatters the to-be-modulated light beam into the first scattered light beam; and a distance between the calibration objective and the scattering medium is a preset focus distance.

[0041] The calibration converging lens converges the received calibration collimated light beam into a calibration light beam.

[0042] The calibration camera receives the calibration light beam and takes a picture to obtain a calibration image.

[0043] The calibration controller generates a scattering medium transmission matrix according to the calibration image, and calibrates the photolithography system based on the scattering medium transmission matrix.

[0044] Compared with the related art, the photolithography calibration device, method, and photolithography system provided by the embodiment of the present application solve the problem of how to ensure that a photolithography pattern reaches a high-precision requirement while reducing the production cost of the photolithography pattern by combining a scattering medium with a low-NA objective and optimizing a photolithography pattern by using a transmission matrix calculation, and achieve a low-cost and high-resolution photolithography effect.

[0045] The details of one or more embodiments of the present application are presented in the following drawings and description to make other features, objects, and advantages of the present application more apparent. BRIEF DESCRIPTION OF DRAWINGS

[0046] The accompanying drawings, which are included to provide a further understanding of the present application, constitute a part of the present application and illustrate exemplary embodiments of the present application and its description, which serve to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0047] Figure 1 is a hardware structure block diagram of a terminal for a photolithography calibration method for a photolithography system according to an embodiment of the present application;

[0048] Figure 2 is a structure schematic diagram of a photolithography calibration device for a photolithography system according to an embodiment of the present application;

[0049] Figure 3is a schematic diagram of real-time lithography information of a lithography system according to an embodiment of the present application;

[0050] Figure 4 is a schematic diagram of a focusing process of another lithography system according to an embodiment of the present application;

[0051] Figure 5 is a flow chart of another lithography calibration method for a lithography system according to an embodiment of the present application;

[0052] Figure 6 is a light path structure diagram of a lithography system according to a preferred embodiment of the present application;

[0053] Figure 7 is a detailed diagram of an objective lens position of a lithography system according to a preferred embodiment of the present application;

[0054] Figure 8 is a specific calibration structure diagram of a lithography system according to a preferred embodiment of the present application. DETAILED DESCRIPTION

[0055] In order to make the objects, technical solutions and advantages of the present application clearer, the present application is described and explained below in connection with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application. Based on the embodiments provided in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of the present application. In addition, it should be understood that although the efforts made in this development process can be complex and lengthy, some designs, manufacturing or production changes made on the basis of the technical content disclosed in the present application by those of ordinary skill in the art related to the content disclosed in the present application are only routine technical means and should not be understood as insufficient disclosure of the present application.

[0056] In the present application, "embodiment" means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment of the present application. The phrase appears at various places in the specification does not necessarily refer to the same embodiment, nor is it mutually exclusive or alternative to other embodiments. It is explicitly and implicitly understood by those of ordinary skill in the art that the embodiments described in the present application can be combined with other embodiments without conflict.

[0057] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms “a,” “an,” “an,” “the,” and similar words used in this application do not indicate quantity limitation and may indicate singular or plural. The terms “comprising,” “including,” “having,” and any variations thereof used in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units not listed, or may include other steps or units inherent to these processes, methods, products, or devices. The terms “connected,” “linked,” “coupled,” and similar words used in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. “Multiple” used in this application means two or more. “And / or” describes the relationship between related objects, indicating that three relationships may exist; for example, “A and / or B” can represent: A alone, A and B simultaneously, and B alone. The terms “first,” “second,” “third,” etc., used in this application are merely to distinguish similar objects and do not represent a specific ordering of the objects.

[0058] The method embodiments provided in this example can be executed on a terminal, computer, or similar computing device. Taking running on a terminal as an example, Figure 1 This is a hardware structure block diagram of the terminal of a photolithography calibration method for a photolithography system according to an embodiment of the present invention. For example... Figure 1 As shown, a terminal may include one or more ( Figure 1 Only one is shown in the diagram. A processor 102 (which may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.) and a memory 104 for storing data are also shown. Optionally, the terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the terminal described above. For example, the terminal may also include components that are more... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0059] The memory 104 can be used to store computer programs, such as software programs of application software and modules, such as a computer program corresponding to the lithography calibration method for a lithography system in the embodiments of the present application. The processor 102 can execute various functional applications and data processing, i.e., implement the above method, by running the computer programs stored in the memory 104. The memory 104 can include a high-speed random access memory, and can further include a non-volatile memory, such as one or more magnetic storage devices, flash memories, or other non-volatile solid-state memories. In some examples, the memory 104 can further include memories remotely arranged with respect to the processor 102, which can be connected to the terminal through a network. Examples of the above network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof.

[0060] The transmission device 106 is configured to receive or send data via a network. Specific examples of the above network can include a wireless network provided by a communication provider of the terminal. In one example, the transmission device 106 includes a network adapter (NIC), which can be connected to other network devices through a base station so as to be capable of communicating with the Internet. In one example, the transmission device 106 can be a radio frequency (RF) module, which is configured to communicate with the Internet in a wireless manner.

[0061] The embodiments of the present application provide a lithography calibration device for a lithography system, the lithography system comprising: a light source, a projection objective, and a scattering medium; Figure 2 is a structural schematic diagram of the lithography calibration device for the lithography system according to the embodiments of the present application, as Figure 2 shown, the lithography calibration device comprises:

[0062] a calibration objective, configured to collimate the first scattered light beam into a calibration collimated light beam; wherein the first scattered light beam is generated by converging a to-be-modulated light beam emitted by the light source on the scattering medium by the projection objective, and is generated by scattering the to-be-modulated light beam by the scattering medium; a distance between the calibration objective and the scattering medium is determined based on a distance between a to-be-lithographed wafer and the scattering medium;

[0063] a calibration converging lens, configured to converge the received calibration collimated light beam into a calibration light beam;

[0064] a calibration camera, configured to receive the calibration light beam and take a picture to obtain a calibration image;

[0065] a calibration controller, configured to calibrate the lithography system according to the calibration image.

[0066] Wherein, in the calibration process, the to-be-modulated light beam emitted by the light source passes through a series of optical paths of the system to reach the projection objective, and the to-be-modulated light beam is converged on the scattering medium by the projection objective, and the to-be-modulated light beam is scattered by the scattering medium to generate a first scattered light beam. The calibration objective collimates the first scattered light beam into a calibration collimated light beam, which ensures that the scattered light beam can be received by the subsequent elements in the form of parallel light, thereby improving the accuracy and stability of the system. In addition, as shown in Figure 2 The focal plane of the calibration objective is usually located below the scattering medium, corresponding to the position of the upper surface of the to-be-photolithographed wafer, to ensure the focusing accuracy during photolithography.

[0067] The calibration converging lens receives the calibration collimated light beam output by the calibration objective and converges it into a calibration light beam. This step helps to focus the light beam in a smaller area, thereby improving the clarity and resolution of the images taken by the calibration camera. In addition, the selection and design of the calibration converging lens should ensure that it can fully receive and converge the scattered light beam, while avoiding excessive divergence or insufficient focusing of the light.

[0068] The calibration camera is used to receive the calibration light beam and take a picture to obtain a calibration image. This step can evaluate the focusing and imaging quality of the system by taking a picture of the projection image of the calibration light beam on the wafer.

[0069] The calibration controller is specifically a processor, single-chip microcomputer, upper computer, etc. deployed in the photolithography calibration device, which is used to perform data processing, logical judgment, and system adjustment tasks during the calibration process. The calibration controller automatically identifies and analyzes the feature information in the calibration image based on the calibration image taken by the calibration camera, and adjusts the relevant parameters (such as the angle of the mirror) of the photolithography system accordingly to calibrate the photolithography system. This step improves the accuracy and resolution of the photolithography pattern by adjusting the corresponding parameters in the photolithography system based on the analysis of the calibration image.

[0070] Through the above steps, the device can achieve accurate calibration of the photolithography system through the cooperation of the calibration objective, the calibration converging lens, and the calibration camera, thereby ensuring the accuracy and consistency of the photolithography pattern. Compared with the traditional photolithography system calibration method, this method uses a combination of a scattering medium and a calibration objective to calibrate a low numerical aperture objective, thereby reducing the cost of the photolithography system and equipment. Moreover, the calibration process is relatively simple and easy to operate, which further reduces the maintenance cost and difficulty of use.

[0071] In some embodiments, the calibration controller is further configured to extract calibration light intensity data and calibration amplitude of the calibration light beam based on the calibration image, input the calibration light intensity data and the calibration amplitude into a parameter optimization model, and generate a scattering medium transmission matrix using the parameter optimization model;

[0072] The calibration controller is also configured to calibrate the lithography system using the scattering medium transmission matrix.

[0073] The calibration camera captures an image containing the calibration light beam, i.e., a calibration image. The calibration image is a binary image, in which each pixel is either 0 or 1, and each pixel corresponds to the on or off of each unit of a DMD device. The DMD device (Digital Micromirror Device) is a micro-mirror group that can receive instructions from a computer host, adjust the posture of each digital micromirror according to the corresponding binary image of the host, and thus adjust the light beam incident on the device to generate a calibration image. A piece of DMD is formed by a large number of tiny square mirror pieces (i.e., a plurality of micro-mirrors) arranged in rows and columns on an electronic node of a silicon wafer. Each micro-mirror corresponds to a pixel (which can be referred to as a subunit) of the generated image.

[0074] The calibration image clearly shows the intensity and distribution of the light beam, and each pixel of the calibration image represents the intensity of the transmitted light. According to the distribution of the light beam, the amplitude of each pixel of the calibration image is 0 or 1, which represents the presence or absence of the light beam. When the amplitude is 0, no light beam enters the optical path within the range of the single pixel.

[0075] The DMD device modulates the light beam according to a plurality of images randomly generated by the host, i.e., generates a plurality of calibration light beams and corresponding calibration images. The vector composed of the amplitudes of the subunits of the nth calibration light beam is Φ n , the vector composed of the light intensities of the subunits of the nth calibration image is I n , and the function relationship between them is:

[0076] I n = |TMΦ n | 2

[0077] where |·| represents the modulo operation. Based on the above function relationship formula, the scattering medium transmission matrix TM can be obtained by using a numerical optimization solving method, i.e., by collecting n calibration images generated under the modulation of the DMD, the vector composed of the amplitudes of the subunits of the nth calibration light beam is Φ n , which is the calibration amplitude, and the vectors corresponding to the n calibration images are φ n , n = 1,..., N. The vector composed of the light intensities of the subunits of the nth calibration image is I n , which is the calibration light intensity data, and the vectors corresponding to the n calibration images are I n, n = 1, …, N. The n sets of calibration amplitude and calibration light intensity data are input into a parameter optimization model, which is a parameter fitting optimization model of the TM transmission matrix;

[0078]

[0079] where tm k denotes the transpose of the kth row vector of the TM matrix;

[0080] I k denotes a vector composed of the light intensity of the kth subunit of all n calibration images;

[0081] where, denotes the amplitude vector of the nth calibration image;

[0082] denotes the square operation of the two-norm.

[0083] By solving the numerical solution of this parameter optimization model, the specific numerical value of the scattering medium transmission matrix is obtained, which is a mathematical matrix describing the change of the light beam in the scattering medium, recording the intensity distribution, phase change and other key information of the light beam in each direction after passing through the scattering medium. The scattering medium may exist between the projection objective and the wafer, and the scattering medium will scatter the incident light beam, causing changes in the intensity distribution and phase of the light beam, which will directly affect the accuracy and resolution of the lithography pattern. Therefore, accurate acquisition of the scattering medium transmission matrix is crucial for the calibration and performance optimization of the lithography system.

[0084] Considering that this parameter optimization problem is a high-dimensional non-convex optimization problem, the computational complexity is O(ab), where a is the row dimension of TM and b is the column dimension of TM. In order to accelerate the above numerical optimization solving process, a fast solving method is designed, which is specifically introduced as follows.

[0085] The designed several calibration light beams follow the form of a circulant convolution matrix, i.e. is a circulant convolution matrix.

[0086] Then, by using the circulant convolution theorem, the matrix multiplication operation in the time domain is converted into the point multiplication operation in the frequency domain to reduce the computational complexity. That is, in the process of solving the numerical solution of optimization, instead of calculating Φ , calculate i ·tm k , where is the basis vector corresponding to the circulant matrix Φ, and F and F -1 represent the fast Fourier transform and the inverse fast Fourier transform, respectively. The calculation complexity is O(alog(b)). Compared with the previous O(ab), the calculation complexity is effectively reduced.

[0087] The precise light intensity and amplitude data extracted by the embodiment provide reliable input for subsequent parameter optimization, which helps to improve the accuracy of calibration; the parameter optimization model can automatically adjust the parameters of the lithography system, and through model optimization, the performance of the lithography system can be significantly improved, such as improving resolution and reducing errors; the scattering medium transmission matrix provides important information for further calibration of the lithography system, and by obtaining the scattering medium transmission matrix, the intensity distribution and phase change of the light beam after passing through the scattering medium can be accurately calculated to ensure that the light beam forms a precise lithography pattern on the wafer, which helps to reduce errors in the lithography process and improve the accuracy and consistency of the lithography pattern.

[0088] In some embodiments, the system further comprises a micro-mirror group;

[0089] The calibration controller is further configured to obtain target light intensity data of a lithography image to be generated; and obtain target image data based on the target light intensity data and the scattering medium transmission matrix;

[0090] The calibration controller is further configured to instruct each micro-mirror in the micro-mirror group to calibrate and deflect to a specified angle based on the target image data.

[0091] In some embodiments, the micro-mirror group is a DMD device; the calibration controller obtains target light intensity data of a lithography image to be generated by reading pre-set parameters of the lithography system or receiving external input, and the target light intensity data usually includes expected light intensity values of each pixel point in the image. The scattering medium transmission matrix and the target light intensity data obtained are substituted into the following function relationship:

[0092] I n = |TMΦ n | 2

[0093] Given the scattering medium transmission matrix TM, the target light intensity data is substituted into I n , and the target image data required for the DMD device to modulate is calculated; based on the target image data, each micro-mirror in the micro-mirror group is instructed to calibrate and deflect to a specified angle. In this embodiment, accurate target light intensity data is the basis of the lithography process, which ensures that the lithography image can be generated as expected and improves the accuracy and consistency of the lithography; by considering the influence of the scattering medium, the calibration controller can generate more accurate target image data, which helps to reduce errors in the lithography process and improve the clarity and resolution of the lithography image; by precisely controlling the deflection angle of the micro-mirror, more complex and fine lithography images can be generated, which improves the quality and stability of the lithography image.

[0094] The embodiment also provides a photolithography system, comprising a light source, a projection objective, a scattering medium, a micro-mirror group, and a photolithography calibration device as any one of the above embodiments;

[0095] The micro-mirror group comprises a plurality of micro-mirrors; each micro-mirror deflects to a specified angle in response to a calibration image; wherein the calibration image is generated by using the photolithography calibration device;

[0096] Each micro-mirror modulates a photolithography beam of the light source into an incident beam at the specified angle;

[0097] The projection objective converges the incident beam on the scattering medium, and the scattering medium scatters the incident beam into a second scattering beam;

[0098] The second scattering beam forms a photolithography image on a wafer to be photolithographed.

[0099] Wherein, after the calibration device is calibrated, photolithography can be performed, in the photolithography process, a photolithography beam of the light source is modulated into an incident beam by each micro-mirror at the specified angle, the photolithography beam is a beam emitted by the light source for photolithography in the photolithography process; each micro-mirror reflects the photolithography beam to different directions according to different deflection angles, thereby realizing modulation of the photolithography beam, the modulated incident beam will have specific intensity distribution and phase distribution, to ensure that the photolithography image is generated as expected.

[0100] The projection objective of the present application has a numerical aperture less than a preset numerical aperture threshold, the projection objective converges the incident beam on the scattering medium, to ensure that the beam maintains high quality and stability in the converging process, the incident beam is a beam converged on the scattering medium by the projection objective in the photolithography process. The scattering medium is a material with specific scattering characteristics, which scatters the incident beam into a second scattering beam, the second scattering beam is a beam generated by the scattering medium in the photolithography process. The second scattering beam scattered by the scattering medium is projected on a wafer to be photolithographed, thereby forming a photolithography image on the wafer to be photolithographed.

[0101] The present application can realize accurate control of the photolithography image by accurately controlling the deflection angle of the micro-mirror and the characteristics of the modulated incident beam, and the small numerical aperture helps to reduce the cost and maintenance difficulty of the projection system. According to the photolithography formula NA represents the numerical aperture of the lithography beam. Therefore, under the condition that the lithography wavelength λ and the process factor K are constant, the resolution of lithography is determined by the numerical aperture NA of the lithography beam, the larger the numerical aperture NA of the lithography beam, the smaller the lithography size, and the higher the lithography resolution. In the related art, the numerical aperture NA of the lithography beam is increased by directly increasing the numerical aperture of the lithography objective lens, which is used to directly project the light beam for lithography to the wafer to be lithographed. However, the present application utilizes a scattering medium and corresponding debugging, so that the scattering angle of the light beam after passing through the scattering medium can determine the numerical aperture NA of the lithography beam. Therefore, the present application expands the scattering angle of the light beam after the scattering medium to expand the numerical aperture NA of the lithography beam. Therefore, only one calibration objective lens with a large numerical aperture NA is needed to calibrate multiple lithography systems using low-cost low-numerical-aperture projection objective lenses. The resolution of these systems can all reach the lithography effect of the large numerical aperture of the calibration objective lens. Therefore, this scheme can greatly reduce the cost of the lithography system.

[0102] In some embodiments, the lithography system comprises:

[0103] a converging lens for converging the modulated light beam modulated by the micro-mirror to an aperture stop; the aperture stop is used for screening the modulated light beam to generate a screened light beam;

[0104] a collimating lens for collimating the screened light beam into an incident light beam.

[0105] In some embodiments, the micro-mirror group is composed of a series of periodic digital micro-mirrors, so the light beam irradiated thereon will also produce diffraction light of different angles. These diffraction lights, such as 0th-order diffraction light, +1st-order diffraction light, and -1st-order diffraction light, will also be received by the converging lens. Different orders of diffraction light are converging on the focal plane of the converging lens and are spaced apart in space, wherein the 0th-order diffraction light converging on the optical axis has the strongest energy. The converging lens is used to focus these light beams into a smaller area, i.e., the position of the aperture stop. The aperture stop is an opening with a specific shape and size, usually located near the focal point of the converging lens, used for screening the modulated light beam, allowing only a specific part of the light beam to pass through, while blocking the other part. Only the 0th-order diffraction light is allowed to pass through, and other diffraction orders are intercepted, thereby generating a screened light beam, which includes 0th-order diffraction light. The screened light beam then reaches the collimating lens, and the screened light beam is collimated into parallel light, which is then received by the projection objective lens.

[0106] The focusing effect of the converging lens can make the energy density of the light beam at the diaphragm higher, which is beneficial for subsequent screening and processing; the screening effect of the diaphragm can remove stray light and unnecessary parts in the modulated light beam, thereby improving the uniformity and directionality of the light beam; the collimating lens can ensure the parallelism of the output light beam, and the parallel light beam is not easy to be disturbed and diverged in the transmission process, which helps to improve the stability and reliability of the entire optical system; the entire process reduces stray light and unnecessary energy loss, thereby improving the overall efficiency of the optical system.

[0107] In some embodiments, the system further comprises a photolithography controller and a wafer stage;

[0108] The wafer stage is used to fix the position of the wafer to be photolithographed;

[0109] The photolithography controller specifically refers to a processor, a single-chip microcomputer or the like arranged in a photolithography calibration device, and is used to perform data processing, logical judgment and system adjustment tasks in the photolithography process; in addition, the photolithography controller and the calibration controller can be the same controller, or two independent controllers can also be used, and the calibration controller and the photolithography controller control the photolithography calibration process and the photolithography process respectively. The photolithography controller is used to generate a photolithography image by driving the wafer stage to move based on the obtained movement direction when the second scattered light beam is subjected to photolithography processing.

[0110] The wafer stage can firmly adsorb the wafer to ensure that the relative position of the wafer does not change during the photolithography process; during the photolithography process, the photolithography controller receives the movement direction indication, then calculates the distance and direction that the wafer stage needs to move; then, the photolithography controller sends instructions to the driving system of the wafer stage to make it move along the predetermined path. The wafer stage has the ability of XYZ three-axis movement, and moves in the XY plane parallel to the upper surface of the wafer during the generation of the photolithography image. The photolithography controller can ensure the accuracy and consistency of the photolithography pattern by precisely controlling the movement of the wafer stage, and the cooperation of the wafer stage and the photolithography controller ensures the accuracy and stability of the photolithography process.

[0111] In some embodiments, the photolithography controller is further used to obtain target image data generated by the calibration controller;

[0112] The photolithography controller is further used to obtain real-time photolithography information of the wafer to be photolithographed;

[0113] The photolithography controller determines the movement direction based on the real-time photolithography information and the target image data.

[0114] In some embodiments, the photolithography controller is further used to obtain target image data generated by the calibration controller; Figure 3 is a schematic diagram of real-time photolithography information of a photolithography system according to an embodiment of the present application, as shown in Figure 3As shown, the lithography controller acquires target image data and acquires real-time state information of the wafer to be lithographed through built-in sensors or external sensor systems (such as laser range finders, image recognition systems, etc.), real-time lithography information including Figure 3 which areas have completed lithography, which are in lithography, and which have not undergone lithography. By analyzing the target image data acquired from the calibration controller and the real-time lithography information, and by comparing these information, the lithography controller can calculate the direction and distance that the wafer stage needs to move, the movement direction being the X-axis and Y-axis directions parallel to the XY plane of the wafer upper surface, to ensure that the lithography pattern can be accurately aligned with the target position. The target image data of the present embodiment provides an accurate alignment reference for the lithography controller, which helps to achieve accurate alignment of the pattern during lithography and reduce errors; the real-time lithography information allows the lithography controller to monitor in real time during lithography and promptly discover and correct possible problems, such as wafer position deviation, inaccurate rotation angle, etc.; based on the comparison of real-time information and target data, the lithography controller can achieve accurate control of the wafer stage to ensure accurate formation of the lithography pattern.

[0115] In some embodiments, the system further comprises an energy control module, a beam stabilizing assembly, a beam expanding module, and a beam shaping module;

[0116] The energy control module is configured to acquire a partial beam energy of the lithography beam based on a preset fixed ratio, calculate an energy stability of the lithography beam based on the partial beam energy, and adjust the light source based on the energy stability;

[0117] The beam stabilizing assembly comprises a plurality of beam stabilizing reflectors; each beam stabilizing reflector is deflected to a specified beam stabilizing angle;

[0118] Each beam stabilizing reflector reflects the lithography beam to a stable beam at the specified beam stabilizing angle;

[0119] The beam expanding module is configured to expand the stable beam to a beam expanded light based on a preset expansion multiple;

[0120] The beam shaping module is configured to shape the beam expanded light into a flat-top beam and reflect the flat-top beam to the micro mirror group.

[0121] The energy control module separates a portion of the light beam energy from the lithography light beam based on a preset fixed ratio (e.g., 5%) through a beam splitter or similar light splitting device, measures the intensity of the portion of the light beam energy using a photosensor or the like sensor, and calculates the energy stability of the lithography light beam, i.e., the degree of energy fluctuation, through an algorithm, for example, if 4.9% of the energy is actually received, the energy stability is (4.9%-5%) / 5%; according to the calculated energy stability, the energy control module adjusts the output power of the light source through a control signal to maintain the energy stability of the lithography light beam, for example, by feeding back the energy stability, the power of the light source (e.g., a laser) is adjusted accordingly to keep the emitted laser energy within a fluctuation range of 3%.

[0122] Most of the light beams (e.g., 95% of the energy) that pass through the energy control module then pass through the beam pointing stabilization assembly, which adjusts the angle of the internal mirror (i.e., the designated stabilization angle) to make the light beams point in the same direction, ensuring the stability of the light beam pointing, and generating a pointing-stable light beam.

[0123] The beam expansion module expands the pointing-stable light beam into an expanded light beam through a lens group or a mirror group or the like optical element according to a preset expansion multiple (e.g., 5 times, 8 times, etc.).

[0124] The beam shaping module shapes the expanded light beam into a flat-top light beam through specific optical elements (e.g., aspherical lenses, diffractive optical elements, etc.), which has a uniform intensity distribution and is beneficial to obtaining a uniform lithography pattern; the shaped flat-top light beam is reflected to the micro-mirror group through a mirror for further control and focusing.

[0125] By maintaining the energy stability of the lithography light beam, the embodiment can reduce the deformation or size deviation of the lithography pattern caused by energy fluctuation, thereby improving the lithography precision; through the use of the beam pointing stabilization assembly, the beam pointing stabilization assembly can compensate for the pointing deviation of the light beam caused by factors such as system vibration and temperature change, thereby improving the stability of the lithography light beam and making the lithography system better adapt to changes in various environmental conditions; the beam expansion module can increase the coverage range of the lithography light beam, making the lithography system capable of processing larger-sized wafers or more complex patterns, and through the expansion of the light beam, the lithography system can cover the entire wafer surface faster, thereby improving the lithography efficiency; the uniform intensity distribution of the flat-top light beam can ensure the uniformity of the lithography pattern and reduce the pattern deformation or defects caused by uneven intensity; through precise beam shaping and focusing, the lithography system can obtain a higher-resolution pattern to meet more precise manufacturing requirements.

[0126] In some embodiments, the system further includes a focusing light source and a focus determiner;

[0127] The focusing light source is used to emit focusing laser to the center of the photoetching area, the focusing laser is reflected by the wafer to the focusing judge, and a focusing light spot is generated on the surface of the focusing judge; wherein, the center of the photoetching area is located on the upper surface of the wafer irradiated by the photoetching light beam;

[0128] The focusing judge is used to record the light spot position of the focusing light spot, and a focusing result is generated based on the light spot position; the wafer carrier is moved based on the focusing result, and the distance between the upper surface of the wafer and the scattering medium is adjusted to a preset focusing distance.

[0129] Wherein, Figure 4 is a focusing process schematic diagram of another photoetching system according to the embodiment of the present application, as Figure 4 shown, the focusing light source is a device capable of emitting laser, and the emitted laser is directed to the center of the photoetching area; the center of the photoetching area refers to the area on the wafer about to be irradiated by the photoetching light beam; when the focusing laser irradiates the wafer surface, part of the laser will be reflected by the wafer, and the reflected laser is then directed to the focusing judge; the focusing judge can receive the reflected focusing laser and form a focusing light spot on its surface; the focusing result is the position of the focusing light spot formed on the surface of the focusing judge; according to the focusing result generated by the focusing judge, the control system or manually issues an instruction to drive the wafer carrier (a platform carrying the wafer) to move up and down (in the Z-axis direction) to adjust the distance between the upper surface of the wafer and the scattering medium, so that it reaches the preset focusing distance. For example, in order to ensure the clarity of the photoetching pattern, it is necessary to ensure that the upper surface of the wafer and the scattering medium maintain a fixed distance of 5mm; through calibration, when the upper surface of the wafer is 5mm away from the scattering medium, the mirror-reflected light spot is just located at the center of the focusing judge, so when the upper surface of the wafer is at other distances from the scattering medium, the relative position of the upper surface of the wafer and the scattering medium at this time can be judged through the position of the focusing light spot formed on the surface of the focusing judge (i.e. the focusing result), and then the wafer carrier is moved up and down correspondingly, so that the mirror-reflected light spot of the focusing laser is just located at the center of the focusing judge, i.e. the upper surface of the wafer is 5mm away from the scattering medium.

[0130] Through the precise focusing process, the embodiment can ensure that the photoetching light beam irradiates the wafer surface at the best focal length, thereby greatly improving the precision and resolution of the photoetching pattern; the existence of the focusing system enables the photoetching system to quickly adjust and maintain a stable focusing state when facing interference factors such as slight unevenness of the wafer surface or system vibration, thereby enhancing the stability of the entire system.

[0131] The embodiment also provides a photoetching calibration method for a photoetching system, the photoetching system comprising: a light source, a projection objective lens and a scattering medium. Figure 5 is a flowchart of another photoetching calibration method for a photoetching system according to the embodiment of the present application, as Figure 5As shown, the process includes the following steps:

[0132] Step S501: The calibration objective lens collimates the first scattered beam into a calibration collimated beam; wherein, the projection objective lens focuses the beam to be modulated emitted by the light source onto the scattering medium, and scatters the beam to be modulated into the first scattered beam through the scattering medium; the distance between the calibration objective lens and the scattering medium is a preset focusing distance.

[0133] Step S502, the calibrating converging lens converges the received calibrating collimated beam into a calibrating beam.

[0134] In step S503, the calibration camera receives the calibration beam and takes a picture to obtain a calibration image.

[0135] In step S504, the calibration controller generates a scattering medium transfer matrix based on the calibration image and calibrates the lithography system based on the scattering medium transfer matrix.

[0136] The embodiments of this application will be described and illustrated below through preferred embodiments.

[0137] Figure 6 This is an optical path structure diagram of a lithography system according to a preferred embodiment of this application, such as... Figure 6 As shown, laser 101 emits a Gaussian laser with good collimation. The laser beam of laser 101 needs to be as close as possible to the Gaussian light distribution, and the M^2 parameter used to evaluate the degree of similarity between the laser beam and the Gaussian light spot distribution needs to be less than 1.1. The wavelengths that can be used for this laser include, but are not limited to, 193nm, 355nm, 260nm, etc.

[0138] The laser emitted from laser 101 passes through energy control module 102. Module 102 receives a fixed small portion (e.g., 5%) of the beam energy to measure the energy stability of the emitted laser and adjusts the power of the laser through feedback to keep the emitted laser energy within a fluctuation range of 3%.

[0139] Most of the beam (95% energy) that passes through the energy control module 102 then passes through the beam pointing stabilization module 103. The beam pointing stabilization module 103 actively adjusts the angle of its internal reflector to make the beam point in the same direction, thus ensuring the stability of the beam pointing.

[0140] The beam then passes through the beam expander module 104, where the beam aperture is expanded to eight times the incident aperture, and then the beam passes through the beam shaping module 105.

[0141] The beam shaping module 105 is usually a diffractive optical element (DOE) or a refractive system based module, both of which have the advantage of not increasing the optical etendue of the incident beam. The beam shaping module 105 can shape the incident Gaussian beam energy distribution into a flat top beam distribution.

[0142] Subsequently, the beam with uniform energy distribution is reflected by the mirror 106. The mirror 106 is oriented at an angle of 6° with respect to the optical axis, so that the beam is reflected at an angle of 12°. The beam tilted by 12° is then incident on the DMD device 107.

[0143] The DMD device 107 is composed of a large number of micro-mirrors, and the angle of deflection of a specified micro-mirror can be achieved by programming. The deflected micro-mirror can reflect a portion of the incident beam parallel to the direction of the optical axis of the laser, thereby achieving the purpose of modulating the beam.

[0144] The beam modulated by the DMD continues to propagate along the direction parallel to the optical axis of the laser, and is focused by the converging lens 108. Since the DMD is composed of a series of periodic digital micro-mirrors, the beam incident thereon will also produce diffracted light of different angles. These diffracted light will also be received and imaged by the lens 108, such as the 0th-order diffracted image, the +1st-order diffracted image, and the -1st-order diffracted image. The diffracted images of different orders are converging on the focal plane of the lens 108 and are spaced apart in space, wherein the 0th-order diffracted light converging on the optical axis has the strongest energy.

[0145] The diaphragm 109 is placed on the focal plane, allowing only the 0th-order diffracted light to pass through, and the other diffracted orders are intercepted.

[0146] The 0th-order diffracted light then reaches the collimating lens 110, and the beam is collimated into parallel light, which is then received by the objective lens 111.

[0147] Figure 7 is a detailed view of the position of the objective lens of the photolithography system according to the preferred embodiment of the present application. The details of the position of the objective lens are shown in Figure 7 The objective lens 111 focuses the incident parallel light on the scattering medium 112, which scatters the incident converging light and scatters it into a beam with a larger angle.

[0148] The mechanical fixing device 113 is used to fix the upper surface of the scattering medium 112 at the focal plane position of the objective lens 111, while ensuring that the plane of the scattering medium is perpendicular to the optical axis.

[0149] The light beam scattered by the scattering medium is then incident on the upper surface of the wafer 201, which is placed on the wafer stage 202.

[0150] The wafer carrier 202 can firmly adsorb the wafer 201, so that the relative position of the wafer 201 will not change during the photolithography process.

[0151] Meanwhile, the wafer carrier 202 has the ability of XYZ three-axis movement, and the resolution of the up-and-down movement of the Z axis needs to be higher than 10 nm.

[0152] The light beam scattered by the scattering medium 112 is the light beam used for realizing photolithography, but in order to ensure the clarity of the photolithography pattern, it is necessary to ensure that the upper surface of the wafer 201 and the scattering medium maintain a fixed distance of 5 mm.

[0153] As shown in FIG. 1, the system uses an automatic focusing system to ensure that the upper surface of the wafer 201 and the scattering medium 112 always maintain a fixed distance of 5 mm. The specific method is that the focusing laser light source 203 emits collimated laser light to the center of the area on the upper surface of the wafer 201 irradiated by the photolithography light beam, and then the light beam is reflected by the wafer surface, and the mirror-reflected light is received by the four focusing detectors 204. Figure 1 Through calibration, when the upper surface of the wafer 201 is at a distance of 5 mm from the scattering medium 112, the mirror-reflected light spot is just located at the center of the four focusing detectors 204.

[0154] When the upper surface of the wafer 201 is at a distance of 5 mm from the scattering medium 112, the mirror-reflected light spot is just located at the center of the four focusing detectors 204.

[0155] When the upper surface of the wafer 201 is at a distance of 5 mm from the scattering medium 112, the mirror-reflected light spot is just located at the center of the four focusing detectors 204.

[0156] The scanning mode for the whole wafer is step-by-step scanning. The wafer carrier 202 can scan in the X and Y directions respectively. After the photolithography of one area is completed, the wafer carrier 202 moves another area of the wafer to the position below the photolithography system. The focusing system always ensures that the upper surface of the wafer 201 and the scattering medium 112 always maintain a fixed distance of 5 mm, so that the whole wafer can be scanned and photolithographed.

[0157] Before the photolithography system can work, the system needs to be calibrated and the transmission matrix needs to be calculated.

[0158] Figure 8 FIG. 2 is a specific calibration structure diagram of the photolithography system according to the preferred embodiment of the present application, as shown in FIG. 2, Figure 8 Figure 8 part of the optical path is omitted, and the system and optical path above the objective lens 111 are not drawn.

[0159] ​When no wafer is placed, the system needs to be calibrated, a calibration objective 301 is placed under the scattering medium 112, the focal plane of which is located at a position 5 mm below the scattering medium, i.e. the position of the wafer upper surface during lithography.

[0160] The scattered light in the above-mentioned lithography system that passes through the objective 111 and is scattered by the scattering medium 112 into a larger-angle light beam is received by the large numerical aperture (NA) objective 301, which needs to be able to completely receive the scattered light beam.

[0161] The collimated light beam after the calibration objective collimation passes through the calibration converging lens 302 and is received by the calibration camera 303.

[0162] The DMD needs to modulate multiple patterns, and the calibration camera 303 receives multiple corresponding images to solve the transmission matrix.

[0163] The specific calculation method and principle of the transmission matrix are as follows: the DMD device 107 is a digital micro-mirror device, which can receive the instructions of the computer host computer, adjust the posture of each digital micro-mirror according to the received binary image of the corresponding host computer, and thus modulate the incident light beam.

[0164] The calculation of the transmission matrix needs the DMD device 107 to modulate the light beam according to the multiple images randomly generated by the host computer, and the modulated light path passes through the subsequent optical path system, passes through the scattering medium 112, and uses the calibration camera 303 to collect the transmission light intensity data after passing through the scattering medium.

[0165] The functional relationship between the incident light modulated by the DMD device 107 and the transmission light obtained after passing through the scattering medium 112 can be represented by the following formula,

[0166] I n = |TMΦ n |2

[0167] Wherein, Φ n represents a vector composed of the amplitude values of each subunit of the nth incident light beam modulated by the DMD device;

[0168] I n represents a vector composed of the intensity of the transmission light obtained after the nth incident light beam passes through the scattering medium, i.e. a vector composed of the light intensity of each subunit of the nth image captured by the calibration camera 303;

[0169] |·| represents the modulo operation; TM represents the transmission matrix of the scattering medium, which is a complex matrix.

[0170] Based on the above functional relationship formula, the transmission matrix of the scattering medium can be obtained by using a numerical optimization solving method.

[0171] The specific way is that the DMD changes the micro-mirror posture to modulate the light beam according to the Nth image transmitted by the host computer, and the modulation image is a binary image, that is, the value is 0 or 1. This modulation image constitutes a vector. Each time the DMD device 107 receives the image modulation light beam, the Nth light intensity data is recorded by the calibration camera 303, and these intensity data are collected into a vector. The calculation process of the transmission matrix will be introduced below.

[0172] The calculation process of the scattering medium transmission matrix (numerical optimization solution) is as follows,

[0173] The experimental group DMD modulates the incident light φ n , n = 1,..., N and the transmitted light data obtained after the scattering medium.

[0174] The following transmission matrix parameter fitting optimization model is established;

[0175]

[0176] Where, tm k represents the transpose of the kth row vector of the TM matrix;

[0177] I k represents the vector composed of the light intensity of the kth subunit of all n images obtained by the calibration camera 303;

[0178] Wherein, φn

[0179] represents the square operation of the two-norm. By solving the numerical solution of the optimization problem, the numerical value of the scattering medium transmission matrix is obtained.

[0180] When the transmission matrix is obtained, and the lithography image data to be obtained is known, the image data that the DMD device needs to modulate can be obtained by calculation. The lithography image needs to be a square image to adapt to the step-by-step scanning scheme, which can be obtained by calculation.

[0181] Those skilled in the art should understand that any combination of the technical features of the above-described embodiments can be made. In order to make the description concise, all possible combinations of the technical features in the above-described embodiments are not described, however, as long as the combination of the technical features does not exist Contradiction, it should be considered as the scope of the present application.

[0182] The above-described embodiments are merely illustrative of several embodiments of the present application, which are described in more detail and in a specific and detailed manner, but should not be construed as limiting the scope of the patent. It should be noted that for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, and these are all within the scope of the present application. Therefore, the scope of protection of the patent of the present application should be subject to the appended claims.

Claims

1. A lithographic calibration apparatus for a lithographic system, characterized in that, The photolithography system comprises a light source, a projection objective, and a scattering medium; the photolithography calibration device comprises: a calibration objective, configured to collimate a first scattered light beam into a calibration collimated light beam; wherein the first scattered light beam is generated by converging a to-be-modulated light beam emitted by the light source on the scattering medium by the projection objective, and scattering the to-be-modulated light beam by the scattering medium; a distance between the calibration objective and the scattering medium is determined based on a distance between a to-be-photolithographed wafer and the scattering medium; a calibration converging lens, configured to converge the received calibration collimated light beam into a calibration light beam; a calibration camera, configured to receive the calibration light beam and take a photograph to obtain a calibration image; a calibration controller, configured to calibrate the photolithography system according to the calibration image; the calibration controller is further configured to extract calibration light intensity data and a calibration amplitude of the calibration light beam based on the calibration image, input the calibration light intensity data and the calibration amplitude into a parameter optimization model, generate a scattering medium transmission matrix by using the parameter optimization model; and the calibration controller is further configured to calibrate the photolithography system by using the scattering medium transmission matrix.

2. A lithographic calibration apparatus according to claim 1, wherein, The system further comprises a micro-mirror group, and the micro-mirror group comprises a plurality of micro-mirrors; The calibration controller is further configured to obtain target light intensity data of a photolithography image to be generated, and obtain target image data based on the target light intensity data and the scattering medium transmission matrix; The calibration controller is further configured to instruct each micro-mirror in the micro-mirror group to calibrate and deflect to a specified angle based on the target image data.

3. A lithographic system, characterized by, The system comprises a light source, a projection objective, a scattering medium, a micro-mirror group, and the photolithography calibration device according to any one of claims 1 to 2; Each micro-mirror deflects to a specified angle in response to the calibration image, wherein the calibration image is generated by using the photolithography calibration device; Each micro-mirror modulates a photolithography light beam of the light source into an incident light beam at the specified angle; The projection objective converges the incident light beam on the scattering medium, and scatters the incident light beam by the scattering medium into a second scattered light beam; The second scattered light beam forms a photolithography image on a to-be-photolithographed wafer.

4. A photolithography system according to claim 3, wherein The photolithography system comprises: a converging lens, configured to converge a modulated light beam modulated by the micro-mirror to an optical stop; the optical stop is configured to screen the modulated light beam to generate a screened light beam; a collimating lens, configured to collimate the screened light beam into the incident light beam.

5. A photolithography system according to claim 3, wherein The system further comprises a photolithography controller and a wafer stage; The wafer stage is configured to fix a position of the to-be-photolithographed wafer; The photolithography controller is configured to instruct the wafer stage to move the to-be-photolithographed wafer based on the obtained movement direction when the second scattered light beam is subjected to photolithography processing, and generate the photolithography image.

6. A photolithography system according to claim 5, wherein, The photolithography controller is further configured to obtain target image data generated by the calibration controller; The photolithography controller is further configured to obtain real-time photolithography information of the to-be-photolithographed wafer; The photolithography controller determines the movement direction based on the real-time photolithography information and the target image data.

7. A photolithography system according to claim 3, wherein The system further comprises an energy control module, a beam stabilizing assembly, a beam expanding module and a beam shaping module; The energy control module is configured to obtain a partial beam energy of the lithography beam based on a preset fixed ratio, calculate an energy stability of the lithography beam based on the partial beam energy, and adjust the light source based on the energy stability; The beam stabilizing assembly comprises a plurality of beam stabilizing reflectors, each of which is deflected to a specified beam stabilizing angle; Each of the beam stabilizing reflectors reflects the lithography beam to a stable beam at the specified beam stabilizing angle; The beam expanding module is configured to expand the stable beam to a beam expanded light beam based on a preset expansion multiple; The beam shaping module is configured to shape the beam expanded light beam into a flat-top beam and reflect the flat-top beam to the micro mirror group.

8. A photolithography system according to claim 3, wherein, The system further comprises a focusing light source and a focusing determinator; The focusing light source is configured to emit a focusing laser to the center of a lithography region, the focusing laser is reflected by the wafer to be lithographed to the focusing determinator, and a focusing light spot is generated on the surface of the focusing determinator; wherein the center of the lithography region is located on the upper surface of the wafer to be lithographed irradiated by the lithography beam; The focusing determinator is configured to record the light spot position of the focusing light spot, generate a focusing result based on the light spot position, and move the wafer to be lithographed based on the focusing result to adjust the distance between the upper surface of the wafer to be lithographed and the scattering medium to a preset focusing distance.

9. A lithographic calibration method for a lithographic system, applied to the lithographic calibration apparatus of any one of claims 1-2, characterized in that, The lithography system comprises a light source, a projection objective and a scattering medium; the method comprises: a calibration objective collimates a first scattering beam into a calibration collimated beam; wherein the projection objective converges a to-be-modulated beam emitted by the light source on the scattering medium, scatters the to-be-modulated beam into the first scattering beam through the scattering medium; the distance between the calibration objective and the scattering medium is a preset focusing distance; a calibration converging lens converges the received calibration collimated beam into a calibration beam; a calibration camera receives the calibration beam and takes a picture to obtain a calibration image; a calibration controller generates a scattering medium transmission matrix according to the calibration image, and calibrates the lithography system based on the scattering medium transmission matrix.

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