Lithographic calibration apparatus and method for lithographic system, and lithographic system

Abstract

The invention relates to photoetching calibration equipment and method for a photoetching system and the photoetching system.The photoetching calibration method comprises the steps that a calibration objective lens collimates a first scattered light beam into a calibration collimated light beam; wherein the projection objective lens gathers a to-be-modulated light beam emitted by the light source on the scattering medium, and the to-be-modulated light beam is scattered into a first scattered light beam through the scattering medium; the distance between the calibration objective lens and the scattering medium is a preset focusing distance; the calibration convergent lens is used for converging the received calibration collimated light beams into calibration light beams; the calibration camera receives the calibration light beam and shoots the calibration light beam to obtain a calibration image; the 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. According to the invention, the problem of how to reduce the production cost while ensuring that the photoetching pattern meets the high-precision requirement is solved, and the low-cost and high-resolution photoetching effect is realized.

Description

Technical Field

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

[0002] Photolithography technology is one of the key processes in the fields of semiconductor manufacturing, micro-nano processing, etc. Its core lies in forming tiny and fine patterns on the surface of materials by precisely controlling the shape, size and position of the light beam.

[0003] In related technologies, photolithography technology mostly uses laser direct writing or projection lithography. Laser direct writing lithography uses a laser beam to scan directly on the surface of the material to form the desired pattern, but this method has certain limitations in terms of beam control, pattern accuracy and efficiency, especially when using a projection lens with a small numerical aperture (NA), the resolution is often limited; projection lithography projects the pattern on the mask onto the material surface through a projection lens, which improves the accuracy and efficiency of the pattern, but the system is highly complex and expensive.

[0004] Currently, no effective solution has been proposed for the problem of how to reduce the production cost while ensuring that the photolithography pattern meets the high precision requirements in the relevant technology. Summary of the invention

[0005] The embodiments of the present application provide a lithography calibration device, method and lithography system for a lithography system, so as to at least solve the problem in the related art of how to reduce the production cost while ensuring that the lithography pattern meets the high precision requirements.

[0006] In a first aspect, an embodiment of the present application provides a lithography calibration device for a lithography system, wherein the lithography system comprises: a light source, a projection lens, and a scattering medium; the lithography calibration device comprises:

[0007] A calibration objective lens, used for collimating the first scattered light beam into a calibration collimated light beam; wherein the first scattered light beam is generated by the projection objective lens converging the light beam to be modulated emitted by the light source onto the scattering medium, and scattering the light beam to be modulated through the scattering medium; the distance between the calibration objective lens and the scattering medium is determined based on the distance between the wafer to be photolithography and the scattering medium;

[0008] A calibration converging lens, used for converging the received calibration collimated light beam into a calibration light beam;

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

[0010] A calibration controller is used to calibrate the lithography system according to the calibration image.

[0011] In some of the embodiments, the calibration controller is further used 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 also used to calibrate the photolithography system using the scattering medium transmission matrix.

[0013] In some of these embodiments, the system further comprises a micro-mirror assembly;

[0014] The calibration controller is also used to obtain target light intensity data of the photolithography image to be generated; and to 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 of the micro-mirrors in the micro-mirror group to calibrate and deflect to a specified angle based on the target image data.

[0016] In a second aspect, an embodiment of the present application provides a lithography system, including a light source, a projection lens, a scattering medium, a micro-mirror group, and a lithography calibration device as described in the first aspect above;

[0017] The micro-mirror group includes a plurality of micro-mirrors; each of the micro-mirrors deflects to a specified angle in response to the calibration image; wherein the calibration image is generated by using the photolithography calibration device;

[0018] Each of the micro-reflectors modulates the photolithography beam of the light source into an incident beam at the specified angle;

[0019] The projection objective lens converges the incident light beam onto 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 photolithography image on the wafer to be photolithographically processed.

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

[0022] A converging lens, used to converge the modulated light beam modulated by the micro-reflector to an aperture; the aperture is used to screen the modulated light beam to generate a screened light beam;

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

[0024] In some of these embodiments, the system further includes a lithography controller and a wafer stage;

[0025] The wafer stage is used to fix the position of the wafer to be photoetched;

[0026] The photolithography controller is used to instruct the wafer stage to move the wafer to be photolithographically processed based on the acquired moving direction when the second scattered light beam is undergoing photolithography processing, so as to generate the photolithography image.

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

[0028] The photolithography controller is also used to obtain real-time photolithography information of the wafer to be photolithographically processed;

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

[0030] In some of these embodiments, the system further comprises an energy control module, a beam stabilization component, a beam expansion module, and a beam shaping module;

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

[0032] The beam stabilizing assembly includes 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 beam into a pointing stable beam at the specified beam stabilizing angle;

[0034] The beam expansion module is used to expand the pointing stable beam to an expanded beam based on a preset expansion factor;

[0035] The beam shaping module is used to shape the expanded beam into a flat-top beam and reflect the flat-top beam to the micro-reflector group.

[0036] In some of the embodiments, the system further includes a focus light source and a focus determiner;

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

[0038] The focus judger is used to record the spot position of the focus spot, and generate a focus result based on the spot position; based on the focus result, the wafer to be photolithography is moved to adjust the distance between the upper surface of the wafer to be photolithography and the scattering medium to a preset focus distance.

[0039] In a third aspect, an embodiment of the present application provides a lithography calibration method for a lithography system, wherein the lithography system comprises: a light source, a projection objective lens, and a scattering medium; the method comprises:

[0040] The calibration objective lens collimates the first scattered light beam into a calibration collimated light beam; wherein the projection objective lens converges the light beam to be modulated emitted by the light source onto the scattering medium, and scatters the light beam to be modulated 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;

[0041] A calibration converging lens is used to converge 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 lithography calibration equipment, method and lithography system for the lithography system provided in the embodiments of the present application, by adopting a combination of scattering medium and low NA objective lens and using transfer matrix calculation to optimize the lithography pattern, solves the problem of how to reduce the production cost while ensuring that the lithography pattern meets the high precision requirements, thereby achieving low-cost, high-resolution lithography effect.

[0045] Details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used 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 lithography calibration method for a lithography system according to an embodiment of the present invention;

[0048] Figure 2 is a schematic structural diagram of a lithography calibration device for a lithography 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 photolithography 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 the position of the objective lens of the lithography system according to the preferred embodiment of the present application;

[0054] Figure 8 It 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 purpose, technical solutions and advantages of the present application clearer, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments provided in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application. In addition, it can also be understood that although the efforts made in this development process may be complex and lengthy, for ordinary technicians in the field related to the contents disclosed in the present application, some changes such as design, manufacturing or production based on the technical contents disclosed in the present application are only conventional technical means, and should not be understood as insufficient contents disclosed in the present application.

[0056] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those of ordinary skill in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0057] Unless otherwise defined, the technical terms or scientific terms involved in this application should be understood by people with ordinary skills in the technical field to which this application belongs. The words "one", "a", "a", "the" and the like involved in this application do not indicate a quantitative limitation, and may represent the singular or plural. The terms "include", "comprise", "have" and any of their variations involved in this application are intended to cover non-exclusive inclusions; 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 that are not listed, or may also include other steps or units inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "multiple" involved in this application refers to greater than or equal to two. "And / or" describes the association relationship of associated objects, indicating that there may be three relationships, for example, "A and / or B" can represent: A exists alone, A and B exist at the same time, and B exists alone. The terms "first", "second", "third" and the like involved in the present application are merely used to distinguish similar objects and do not represent a specific ordering of the objects.

[0058] The method embodiment provided in this embodiment can be executed in a terminal, a computer or a similar computing device. Taking running on a terminal as an example, Figure 1 FIG. 1 is a hardware structure block diagram of a terminal for a lithography calibration method for a lithography system according to an embodiment of the present invention. Figure 1 As shown, the terminal may include one or more ( Figure 1 Only one is shown in the figure) a processor 102 (the processor 102 may include but is not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA) and a memory 104 for storing data. Optionally, the terminal may also include a transmission device 106 and an input / output device 108 for communication functions. It can be understood by those skilled in the art that Figure 1 The structure shown is for illustration only and does not limit the structure of the above terminal. Figure 1 More or fewer components as shown, or with Figure 1 Different configurations are shown.

[0059] The memory 104 can be used to store computer programs, for example, software programs and modules of application software, such as the computer program corresponding to the photolithography calibration method for the photolithography system in the embodiment of the present invention. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, that is, to implement the above method. The memory 104 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 104 may further include a memory remotely arranged relative to the processor 102, and these remote memories may be connected to the terminal via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0060] The transmission device 106 is used to receive or send data via a network. The specific example of the above network may include a wireless network provided by a communication provider of the terminal. In one example, the transmission device 106 includes a network adapter (Network Interface Controller, referred to as NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the transmission device 106 can be a radio frequency (Radio Frequency, referred to as RF) module, which is used to communicate with the Internet wirelessly.

[0061] This embodiment provides a lithography calibration device for a lithography system, the lithography system comprising: a light source, a projection objective lens, and a scattering medium; Figure 2 is a schematic diagram of the structure of a lithography calibration device for a lithography system according to an embodiment of the present application, such as Figure 2 As shown, the lithography calibration equipment includes:

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

[0063] A calibration converging lens, used for converging the received calibration collimated light beam into a calibration light beam;

[0064] A calibration camera is used to receive the calibration beam and take pictures to obtain a calibration image;

[0065] The calibration controller is used to calibrate the lithography system according to the calibration image.

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

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

[0068] The calibration camera is used to receive the calibration beam and shoot it to obtain a calibration image. This step can evaluate the focus and imaging quality of the system by shooting the projection image of the calibration beam on the wafer.

[0069] The calibration controller specifically refers to the processor, single-chip microcomputer, host computer, etc. deployed in the lithography calibration equipment, which is responsible for performing 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 of the lithography system (such as the angle of the reflector, etc.) accordingly to calibrate the lithography system. This step improves the accuracy and resolution of the lithography pattern by analyzing the calibration image and adjusting the corresponding parameters in the lithography system accordingly.

[0070] Through the above steps, the device can realize accurate calibration of the lithography system by using the calibration objective lens, the calibration converging lens and the calibration camera in combination, thereby ensuring the accuracy and consistency of the lithography pattern; compared with the traditional lithography system calibration method, the method adopts a combination of scattering medium and calibration objective lens, which can realize the calibration of low numerical aperture objective lens, thereby reducing the cost of lithography system and equipment; and because the calibration process is relatively simple and easy to operate, it also further reduces the maintenance cost and difficulty of use.

[0071] In some of the embodiments, the calibration controller is further used 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 calibration amplitude into the parameter optimization model, and generate the scattering medium transmission matrix using the parameter optimization model;

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

[0073] Among them, the calibration camera captures an image containing the calibration beam, that is, the calibration image. The calibration image is a binary image, in which each pixel is either 0 or 1, and each pixel corresponds to each unit of the DMD device, which is either on or off. The DMD device (Digital Micromirror Device) is a group of micro-mirrors, which can receive instructions from a computer host computer, and adjust the posture of each individual digital micro-mirror according to the binary image received from the corresponding host computer, so that the light beam incident on this device can be debugged accordingly to generate a calibration image. A DMD is formed by many tiny square reflective lenses (i.e., several micro-mirrors) closely arranged in rows and columns and attached to the electronic nodes of a silicon chip. Each micro-mirror corresponds to a pixel (which can be called a sub-unit) that generates an image.

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

[0075] The DMD device modulates the light beam according to the multiple images randomly generated by the host computer, that is, generates several calibration beams and corresponding calibration images. The vector composed of the amplitudes of each subunit of the nth calibration beam is Φ n , the vector composed of the light intensity of each subunit of the nth calibration image is I n ; TM represents the scattering medium transmission matrix, which is a complex matrix; the functional relationship between them is:

[0076] I n =|TMΦ n | 2

[0077] Where |·| represents a modulo operation. Based on the above functional relationship formula, the scattering medium transmission matrix TM can be obtained by using a numerical optimization solution method, that is, collecting n calibration images generated under n sets of DMD modulation, and the vector composed of the amplitudes of each subunit of the nth calibration beam is Φ n , this vector is the calibration amplitude, n calibration images correspond to n vectors φ n ,n=1,...,N; the vector composed of the light intensity of each subunit of the nth calibration image is I n , this vector is the calibration light intensity data, n calibration images correspond to n vectors I n, n=1,...,N. n groups of calibration amplitude and calibration light intensity data are input into the parameter optimization model, and the parameter optimization model is a parameter fitting optimization model of the TM transmission matrix;

[0078]

[0079] Among them, tm k represents the transpose of the k-th row vector of the TM matrix;

[0080] I k A vector representing the light intensity of the kth subunit of all n calibration images;

[0081] in, represents the magnitude vector of the nth calibration image;

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

[0083] By solving the numerical solution of this parameter optimization model, the specific value of the scattering medium transmission matrix is ​​obtained. The scattering medium transmission matrix is ​​a mathematical matrix that describes the changes of the light beam when it is transmitted in the scattering medium. It records the key information such as the intensity distribution and phase change in all directions after the light beam passes through the scattering medium. The scattering medium may exist between the projection objective and the wafer. The scattering medium will scatter the incident light beam, causing the intensity distribution and phase of the light beam to change. These changes will directly affect the accuracy and resolution of the lithography pattern. Therefore, accurately obtaining 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 speed up the above numerical optimization solution process, we designed a fast solution method, which is described below.

[0085] The designed calibration beams follow the form of a circular convolution matrix, namely is a circular convolution matrix.

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

[0087] The precise light intensity and amplitude data extracted in this 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. Through model optimization, the performance of the lithography system can be significantly improved, such as improving resolution, reducing errors, etc.; the scattering medium transmission matrix provides important information for further calibration of the lithography system. 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 an accurate 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 of these embodiments, the system further comprises a micro-mirror assembly;

[0089] The calibration controller is also used to obtain target light intensity data of the photolithography image to be generated; and based on the target light intensity data and the scattering medium transmission matrix, obtain target image data;

[0090] The calibration controller is further used 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] The micro-mirror group is a DMD device; the calibration controller obtains the target light intensity data of the photolithography image to be generated by reading the preset parameters of the photolithography system or receiving external input. The target light intensity data usually includes the expected light intensity value of each pixel in the image. Substitute the acquired scattering medium transmission matrix and target light intensity data into the following functional relationship:

[0092] I n =|TMΦ n | 2

[0093] Given the scattering medium transmission matrix TM, substitute the target light intensity data into I n , calculate the target image data that the DMD device needs to modulate; based on the target image data, instruct each micro-mirror in the micro-mirror group to calibrate and deflect to a specified angle. In this embodiment, accurate target light intensity data is the basis of the photolithography process, which ensures that the photolithography image can be generated as expected and improves the accuracy and consistency of the photolithography; 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 photolithography process and improve the clarity and resolution of the photolithography image; by accurately controlling the deflection angle of the micro-mirror, a more complex and fine photolithography image can be generated, which improves the quality and stability of the photolithography image.

[0094] This embodiment further provides a photolithography system, comprising a light source, a projection objective lens, a scattering medium, a micro-mirror group, and any one of the photolithography calibration devices in the above embodiments;

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

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

[0097] The projection objective lens converges the incident light beam onto the scattering medium, and scatters the incident light beam into a second scattered light beam through the scattering medium;

[0098] The second scattered light beam forms a photolithography image on the wafer to be photolithographically processed.

[0099] Among them, lithography can be carried out after the calibration equipment is calibrated. During the lithography process, the lithography beam of the light source is modulated into an incident beam by each micro-mirror at a specified angle. The lithography beam is the beam used for lithography emitted by the light source during the lithography process; each micro-mirror will reflect the lithography beam in different directions according to different deflection angles, thereby realizing the modulation of the lithography beam. The modulated incident beam will have a specific intensity distribution and phase distribution to ensure that the lithography image is generated as expected.

[0100] The projection objective lens of the present application has a numerical aperture less than a preset numerical aperture threshold, and the projection objective lens converges an incident light beam on a scattering medium to ensure that the light beam maintains high quality and stability during the convergence process. The incident light beam is a light beam converged on the scattering medium by the projection objective lens during the photolithography process. The scattering medium is a material with specific scattering properties, which scatters the incident light beam into a second scattered light beam, and the second scattered light beam is a light beam generated by scattering of the scattering medium during the photolithography process. The second scattered light beam scattered by the scattering medium is projected onto a wafer to be photolithographically processed, thereby forming a photolithographic image on the wafer to be photolithographic processed.

[0101] This application can achieve precise control of the lithography image by precisely controlling the deflection angle of the micro-mirror and modulating the characteristics of the incident light beam, and a smaller numerical aperture helps reduce the cost and maintenance difficulty of the projection system. NA represents the numerical aperture of the lithography beam. Therefore, when the lithography wavelength λ and the process factor K are constant, the resolution of the 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. This lithography objective lens directly projects the light beam used for lithography onto the wafer to be lithography. However, the present application utilizes a scattering medium and corresponding adjustments, 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 numerical aperture NA of the lithography beam by expanding the scattering angle of the light beam after the scattering medium. Therefore, only a calibration objective lens with a large numerical aperture NA is needed to calibrate multiple sets of lithography systems using low-cost, low-numerical aperture projection objective lenses. The resolution of these systems can achieve the lithography effect under the large numerical aperture of the calibration objective lens. Therefore, this solution can greatly reduce the cost of the lithography system.

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

[0103] A converging lens is used to converge the modulated light beam modulated by the micro-reflector to the aperture; the aperture is used to screen the modulated light beam to generate a screened light beam;

[0104] Collimating lens, used to collimate the screened beam into the incident beam.

[0105] Among them, since the micro-mirror group is composed of a series of periodic digital micro-mirrors, the light beam irradiated thereon will also generate diffracted light at different angles, which will also be received by the converging lens, such as 0th order diffracted light, +1st order diffracted light, -1st order diffracted light. The diffracted light of different orders converges on the focal plane of the converging lens and is spaced apart in space, among which the 0th order diffracted light converged on the optical axis has the strongest energy. The function of the converging lens is to focus these light beams into a smaller area, that is, the position of the aperture. The aperture is an opening with a specific shape and size, usually located near the focus of the converging lens, and is used to screen the modulated light beam, allowing only a specific part of the light beam to pass through, while blocking other parts, allowing only the 0th order diffracted light to pass through, and other diffracted order lights are intercepted, thereby generating a screened light beam, which includes the 0th order diffracted light. The screened light beam then reaches the collimating lens, where the screened light beam is collimated into parallel light and then received by the projection objective.

[0106] In this embodiment, the focusing effect of the converging lens can make the energy density of the light beam at the aperture higher, which is beneficial to subsequent screening and processing; the screening effect of the aperture can remove stray light and unnecessary parts in the modulated light beam, and improve 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 easily disturbed and diverged during the transmission process, which helps to improve the stability and reliability of the entire optical system; the stray light and unnecessary energy loss are reduced in the whole process, and the overall efficiency of the optical system is improved.

[0107] In some of these embodiments, the system further includes a lithography controller and a wafer stage;

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

[0109] The photolithography controller specifically refers to the processor, single-chip microcomputer, etc. deployed in the photolithography calibration equipment, which is responsible for performing 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 be used, and the calibration controller and the photolithography controller respectively control the photolithography calibration process and the photolithography process. The photolithography controller is used to generate a photolithography image by instructing the wafer stage to translate the wafer to be photolithography based on the acquired moving direction when the second scattered light beam is performing photolithography processing.

[0110] Among them, the wafer stage can firmly adsorb the wafer to ensure that its relative position does not change during the lithography process; during the lithography process, the lithography controller will receive the movement direction instruction, and then calculate the distance and direction that the wafer stage needs to move; then, the lithography controller sends instructions to the drive system of the wafer stage to make it translate along a predetermined path. The wafer stage has the ability to move in three axes, XYZ. In the process of generating lithography images, the wafer stage moves in the XY plane parallel to the upper surface of the wafer. In this embodiment, by precisely controlling the movement of the wafer stage, the lithography controller can ensure the accuracy and consistency of the lithography pattern. The synergy between the wafer stage and the lithography controller ensures the accuracy and stability of the lithography process.

[0111] In some of these embodiments, the lithography controller is further configured to acquire target image data generated by the calibration controller;

[0112] The lithography controller is also used to obtain real-time lithography information of the wafer to be lithography;

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

[0114] in, Figure 3 is a schematic diagram of real-time lithography information of a lithography system according to an embodiment of the present application, such as Figure 3As shown, the lithography controller obtains the target image data and obtains the current status information of the wafer to be lithography in real time through the built-in sensor or external sensor system (such as laser rangefinder, image recognition system, etc.). The real-time lithography information includes Figure 3 Which areas have completed lithography, which are in the process of lithography, and which are not undergoing lithography. Analyze the target image data obtained from the calibration controller and the real-time lithography information. By comparing this information, the lithography controller can calculate the direction and distance that the wafer stage needs to move. The movement direction is the X-axis and Y-axis direction of the XY plane parallel to the upper surface of the wafer to ensure that the lithography pattern can be accurately aligned with the target position. The target image data of this embodiment provides an accurate alignment reference for the lithography controller, which helps to achieve accurate alignment of the pattern and reduce errors during the lithography process; real-time lithography information allows the lithography controller to monitor in real time during the lithography process, and promptly discover and correct possible problems, such as wafer position offset, 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 the accurate formation of the lithography pattern.

[0115] In some of these embodiments, the system further includes an energy control module, a beam stabilization assembly, a beam expansion module, and a beam shaping module;

[0116] The energy control module is used to obtain partial beam energy of the lithography beam based on a preset fixed ratio; calculate the 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 includes a plurality of beam stabilizing reflectors; each beam stabilizing reflector is deflected to a specified beam stabilizing angle;

[0118] Each beam stabilization reflector reflects the photolithography beam into a pointing stable beam at a specified beam stabilization angle;

[0119] The beam expansion module is used to expand the pointing stable beam to an expanded beam based on a preset expansion factor;

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

[0121] Among them, the energy control module separates a part of the beam energy from the lithography beam based on a preset fixed ratio (such as 5%) through a spectrometer or a similar spectroscopic device, measures the intensity of the part of the beam energy using sensors such as photodetectors, and calculates the energy stability of the lithography beam through an algorithm, that is, the degree of energy fluctuation. For example, if 4.9% 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 beam, for example, by feeding back the energy stability, the power of the light source (such as a laser) is adjusted accordingly to keep the emitted laser energy within a fluctuation range of 3%.

[0122] Most of the light beam that passes through the energy control module (such as 95% of the energy) then passes through the beam pointing stabilization component. The beam stabilization component actively adjusts the angle of its internal reflector (i.e., the specified beam stabilization angle) to point the light beam in the same direction, thereby ensuring the stability of the beam pointing and generating a pointing-stable beam.

[0123] The beam expansion module expands the stable light beam into an expanded light beam according to a preset magnification (such as 5 times, 8 times, etc.) through optical elements such as a lens group or a reflector group.

[0124] The beam shaping module uses specific optical elements (such as aspheric lenses, diffractive optical elements, etc.) to shape the expanded beam into a flat-top beam. The flat-top beam has a uniform intensity distribution, which is conducive to obtaining a uniform lithography pattern; the shaped flat-top beam is reflected to the micro-mirror group through a reflector for further control and focusing.

[0125] This embodiment can reduce the deformation or size deviation of the lithography pattern caused by energy fluctuations by maintaining the energy stability of the lithography beam, thereby improving the lithography accuracy; through the use of a beam stabilizing component, the beam stabilizing component can compensate for the beam pointing deviation caused by system vibration, temperature change and other factors, thereby improving the stability of the lithography beam and enabling the lithography system to better adapt to changes in various environmental conditions; the beam expansion module can increase the coverage range of the lithography beam, enabling the lithography system to process larger wafers or more complex patterns, and by expanding the beam, the lithography system can cover the entire wafer surface more quickly, thereby improving the lithography efficiency; the uniform intensity distribution of the flat-top 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 higher resolution patterns to meet more sophisticated manufacturing requirements.

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

[0127] The focus light source is used to emit a focus laser to the center of the photolithography area. The focus laser is reflected by the wafer to the focus judgement device, and a focus spot is generated on the surface of the focus judgement device. The center of the photolithography area is located on the upper surface of the wafer irradiated by the photolithography beam.

[0128] The focus judger is used to record the spot position of the focus spot and generate a focus result based on the spot position; the wafer stage is moved based on the focus result to adjust the distance between the upper surface of the wafer and the scattering medium to a preset focus distance.

[0129] in, Figure 4 is a schematic diagram of a focusing process of another photolithography system according to an embodiment of the present application, such as Figure 4 As shown, the focus light source is a device that can emit laser, and the laser it emits is directed to the center of the lithography area; the center of the lithography area refers to the area on the wafer that will be irradiated by the lithography beam; when the focus laser is irradiated onto the surface of the wafer, part of the laser will be reflected by the wafer, and the reflected laser is then directed to the focus judge; the focus judge can receive the reflected focus laser and form a focus spot on its surface; the focus result is the position of the focus spot formed on the surface of the focus judge, and according to the focus result generated by the focus judge, the control system or manually issues a command to drive the wafer carrier (the platform that carries the wafer) to move up and down (Z-axis direction) to adjust the distance between the upper surface of the wafer and the scattering medium so that it reaches a preset focus distance. For example, in order to ensure the clarity of the photolithography pattern, it is necessary to ensure that the upper surface of the wafer maintains a fixed distance of 5mm from the scattering medium. Through calibration, when the upper surface of the wafer is 5mm away from the scattering medium, the mirror-reflected light spot is exactly located in the center of the focus judgement. Therefore, 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 by the position of the focus light spot formed on the surface of the focus judgement (i.e., the focusing result), and then the wafer stage is moved up and down accordingly, so that the light spot of the focus laser mirror reflection is exactly located in the center of the focus judgement, that is, the upper surface of the wafer is 5mm away from the scattering medium.

[0130] Through a precise focusing process, this embodiment can ensure that the lithography beam is irradiated to the wafer surface at an optimal focal length, thereby greatly improving the accuracy and resolution of the lithography pattern; the existence of the focusing system enables the lithography system to quickly adjust and maintain a stable focusing state when faced with interference factors such as slight unevenness on the wafer surface or system vibration, thereby enhancing the stability of the entire system.

[0131] This embodiment also provides a lithography calibration method for a lithography system. The lithography system includes: a light source, a projection lens, and a scattering medium. Figure 5 is a flow chart of another lithography calibration method for a lithography system according to an embodiment of the present application. Figure 5As shown, the process includes the following steps:

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

[0133] Step S502 : A calibration converging lens is used to converge the received calibration collimated light beam into a calibration light beam.

[0134] Step S503: The calibration camera receives the calibration light beam and takes a picture to obtain a calibration image.

[0135] Step S504: 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.

[0136] The embodiments of the present application are described and illustrated below through preferred embodiments.

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

[0138] The laser emitted from the laser 101 passes through the energy control module 102. The module 102 receives a fixed small portion (such as 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 light beam (95% of the energy) that passes through the energy control module 102 then passes through the light beam pointing stabilization module 103. The light beam pointing stabilization module 103 actively adjusts the angle of its internal reflector to point the light beam in the same direction, thereby ensuring the stability of the light beam pointing.

[0140] Then the light beam passes through the beam expansion module 104 , and the beam diameter is expanded to 8 times of the incident diameter. Then the light beam passes through the beam shaping module 105 .

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

[0142] Then, the light beam with uniform energy distribution passes through the reflector 106 and is reflected by the reflector 106. The normal direction of the reflector 106 is 6° to the optical axis direction, so the light beam is reflected at an angle of 12°, and the light beam inclined by 12° is then incident on the DMD device 107.

[0143] The DMD device 107 is composed of numerous micro-mirrors, and the angle deflection of the specified micro-mirrors can be realized through programming. The deflected micro-mirrors can reflect part of the incident light beam to a direction parallel to the laser output optical axis, thereby achieving the purpose of modulating the light beam.

[0144] The light beam modulated by the DMD continues to propagate in a direction parallel to the laser output optical axis, and is focused after being converged by the converging lens 108. Because the DMD is composed of a series of periodic digital micromirrors, the light beam irradiated thereon will also generate diffracted light at different angles. These diffracted lights will also be received and imaged by the lens 108, such as the 0th order diffraction image, the +1st order diffraction image, and the -1st order diffraction image. The diffraction images of different orders converge on the focal plane of the lens 108 and are spaced apart in space, among which the 0th order diffraction light converged on the optical axis has the strongest energy.

[0145] A stop 109 is placed on the focal plane to allow only the 0th order diffraction light to pass through, while other diffraction order lights are intercepted.

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

[0147] Figure 7 is a detailed diagram of the position of the objective lens of the lithography system according to the preferred embodiment of the present application, and the details of the position of the objective lens are as follows Figure 7 As shown in the magnified image, the objective lens 111 converges and focuses the incident parallel light onto the scattering medium 112, and the scattering medium scatters the incident convergent light and scatters it into a light 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, and at the same time ensure that the plane of the scattering medium is perpendicular to the incident light axis.

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

[0150] The wafer stage 202 can firmly absorb the wafer 201 to ensure that its relative position does not change during the photolithography process.

[0151] At the same time, the wafer stage 202 has the ability to move in three axes, XYZ, 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 to implement photolithography. However, in order to ensure the clarity of the photolithography pattern, it is necessary to ensure that the upper surface of the wafer 201 maintains a fixed distance of 5 mm from the scattering medium.

[0153] like Figure 1 As shown, 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 a collimated laser to illuminate the center of the area on the upper surface of the wafer illuminated by the photolithography beam, and then the beam is reflected by the wafer surface, and the specular scattered light is received by the focus judgement device 204.

[0154] Through calibration, when the upper surface of the wafer 201 is 5 mm away from the scattering medium 112 , the specularly reflected light spot is exactly located at the center of the focus judgement device 204 .

[0155] When the upper surface of the wafer 201 is at other distances from the scattering medium 112, the relative position of the upper surface of the wafer 201 and the scattering medium 112 can be determined, and the wafer carrier 202 can be moved up and down so that the light spot reflected by the focusing laser mirror is exactly located in the center of the 4 focusing judgement device 204, that is, the upper surface of the wafer 201 is 5 mm away from the scattering medium 112.

[0156] The scanning method for the entire wafer is step scanning, and the wafer stage 202 can scan in the X and Y directions respectively. After one area is photolithographically processed, the wafer stage 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 5mm, so that the entire wafer is scanned and photolithographically processed.

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

[0158] Figure 8 is a specific calibration structure diagram of a lithography system according to a preferred embodiment of the present application, such as Figure 8 As shown, Figure 8 A portion of the optical path is simplified, 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, and a calibration lens 301 is placed under the scattering medium 112. The focal plane of the calibration lens 301 is located 5 mm below the scattering medium, that is, the upper surface position of the wafer during photolithography.

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

[0161] The light beam collimated by the calibration objective lens is then converged by the calibration converging lens 302 and 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 micromirror device, which can receive instructions from a computer host computer, and adjust the posture of each individual digital micromirror according to the binary image received from the corresponding host computer, so as to achieve the purpose of modulating the incident light beam.

[0164] The calculation of the transmission matrix requires the DMD device 107 to modulate the light beam according to the multiple images randomly generated by the host computer. The modulated light path passes through the subsequent light path system and the scattering medium 112, and the calibration camera 303 is used to collect the transmitted 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 transmitted light obtained after passing through the scattering medium 112 can be expressed by the following formula:

[0166] I n =|TMΦ n |2

[0167] Among them, Φ n A vector consisting of the amplitudes of the subunits representing the nth incident light beam modulated by the DMD device;

[0168] I n represents a vector composed of the intensity of the transmitted light obtained after the n-th incident light beam passes through the scattering medium, that is, a vector composed of the light intensities of each subunit of the n-th image captured by the calibration camera 303;

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

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

[0171] The specific method is that the DMD changes the micromirror posture to modulate the light beam according to the Nth image transmitted by the host computer. The modulated image is a binary image, that is, the value is 0 or 1. This modulated image forms a vector. Every time the DMD device 107 receives the image modulated light beam, it uses the calibration camera 303 to shoot and record the Nth light intensity data, and synthesizes these intensity data 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] Using the experimental acquisition group DMD modulated incident light φ n ,n=1,...,N and the transmitted light data obtained after passing through the scattering medium.

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

[0175]

[0176] Among them, tm k represents the transpose of the k-th row vector of the TM matrix;

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

[0178] Wherein, it represents the amplitude vector of the nth incident light beam modulated by DMD;

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

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

[0181] Those skilled in the art should understand that the technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0182] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A lithography calibration device for a lithography system, characterized in that: The photolithography system comprises: a light source, a projection lens and a scattering medium; the photolithography calibration device comprises: A calibration objective lens, used for collimating the first scattered light beam into a calibration collimated light beam; wherein the first scattered light beam is generated by the projection objective lens converging the light beam to be modulated emitted by the light source onto the scattering medium, and scattering the light beam to be modulated through the scattering medium; the distance between the calibration objective lens and the scattering medium is determined based on the distance between the wafer to be photolithography and the scattering medium; A calibration converging lens, used for converging the received calibration collimated light beam into a calibration light beam; A calibration camera, used to receive the calibration light beam and take a picture to obtain a calibration image; A calibration controller is used to calibrate the lithography system according to the calibration image.

2. A photolithography calibration device according to claim 1, characterized in that: The calibration controller is further used 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; The calibration controller is also used to calibrate the photolithography system using the scattering medium transmission matrix.

3. A photolithography calibration device according to claim 2, characterized in that: The system also includes a micro-mirror group, wherein the micro-mirror group includes a plurality of micro-mirrors; The calibration controller is also used to obtain target light intensity data of the photolithography image to be generated; and to 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 of the micro-mirrors in the micro-mirror group to calibrate and deflect to a specified angle based on the target image data.

4. A photolithography system, characterized in that: A photolithography calibration device comprising a light source, a projection lens, a scattering medium, a micro-mirror group, and the photolithography calibration device according to any one of claims 1 to 3; Each of the micro-reflectors is deflected to a specified angle in response to the calibration image; wherein the calibration image is generated by using the photolithography calibration device; Each of the micro-reflectors modulates the photolithography beam of the light source into an incident beam at the specified angle; The projection objective lens converges the incident light beam onto the scattering medium, and scatters the incident light beam into a second scattered light beam through the scattering medium; The second scattered light beam forms a photolithography image on the wafer to be photolithographically processed.

5. A photolithography system according to claim 4, characterized in that: The photolithography system comprises: A converging lens, used to converge the modulated light beam modulated by the micro-reflector to an aperture; the aperture is used to screen the modulated light beam to generate a screened light beam; A collimating lens is used to collimate the screened light beam into the incident light beam.

6. A photolithography system according to claim 4, characterized in that: The system also includes a lithography controller and a wafer stage; The wafer stage is used to fix the position of the wafer to be photoetched; The photolithography controller is used to instruct the wafer stage to move the wafer to be photolithographically processed based on the acquired moving direction when the second scattered light beam is undergoing photolithography processing, so as to generate the photolithography image.

7. A photolithography system according to claim 6, characterized in that: The photolithography controller is also used to obtain target image data generated by the calibration controller; The photolithography controller is also used to obtain real-time photolithography information of the wafer to be photolithographically processed; The lithography controller determines the moving direction based on the real-time lithography information and the target image data.

8. A photolithography system according to claim 4, characterized in that: The system also includes an energy control module, a beam stabilization component, a beam expansion module and a beam shaping module; The energy control module is used to obtain a portion of the beam energy of the lithography beam based on a preset fixed ratio; calculate the energy stability of the lithography beam based on the portion of the beam energy, and adjust the light source based on the energy stability; The beam stabilizing assembly includes a plurality of beam stabilizing reflectors; each of the beam stabilizing reflectors is deflected to a specified beam stabilizing angle; Each of the beam stabilizing reflectors reflects the photolithography beam into a pointing stable beam at the specified beam stabilizing angle; The beam expansion module is used to expand the pointing stable beam to an expanded beam based on a preset expansion factor; The beam shaping module is used to shape the expanded beam into a flat-top beam and reflect the flat-top beam to the micro-reflector group.

9. A photolithography system according to claim 4, characterized in that: The system also includes a focus light source and a focus determiner; The focusing light source is used to emit a focusing laser to the center of the photolithography area, and the focusing laser is reflected by the wafer to be photolithography to the focus judgement device, and a focusing spot is generated on the surface of the focus judgement device; wherein the center of the photolithography area is located on the upper surface of the wafer to be photolithography irradiated by the photolithography light beam; The focus judger is used to record the spot position of the focus spot, and generate a focus result based on the spot position; based on the focus result, the wafer to be photolithography is moved to adjust the distance between the upper surface of the wafer to be photolithography and the scattering medium to a preset focus distance.

10. A lithography calibration method for a lithography system, characterized in that: The photolithography system comprises: a light source, a projection lens and a scattering medium; the method comprises: The calibration objective lens collimates the first scattered light beam into a calibration collimated light beam; wherein the projection objective lens converges the light beam to be modulated emitted by the light source onto the scattering medium, and scatters the light beam to be modulated 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 is used to converge the received calibration collimated light beam into a calibration light beam; The calibration camera receives the calibration light beam and takes a picture to obtain a calibration image; 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.

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