Lithographic system illumination correction method, lithographic system, apparatus, medium and product

Abstract

This application discloses a method, system, apparatus, medium, and product for illumination correction in a lithography system, relating to the field of semiconductor technology. The method includes: acquiring a first light intensity of a correction plane and a second light intensity of a wafer plane in the lithography system, wherein the correction plane is located in front of a variable slit in the illumination subsystem of the lithography system; calculating a transmission factor between the correction plane and the wafer plane based on the first and second light intensities; iteratively adjusting a target light intensity distribution on the wafer plane based on the first light intensity, the transmission factor, and a preset illumination intensity distribution to obtain a target phase distribution corresponding to the correction plane, wherein the target phase distribution is used to determine a correction unit placed on the correction plane, and the correction unit is used to correct the illumination uniformity of the corresponding illumination field in the lithography system. This application solves the technical problem of poor correction effect.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and in particular to a method for illumination correction of a lithography system, a lithography system, equipment, a medium, and a product. Background Technology

[0002] In the semiconductor manufacturing field, as the feature size of integrated circuits continues to shrink, extremely high demands are placed on the precision and stability of photolithography processes. The illumination system of a photolithography machine is responsible for generating a highly uniform illumination field on the mask surface. Its uniformity directly determines the quality of the exposed lines and the fidelity of the pattern transfer. Therefore, the integral uniformity of the illumination field is a key indicator for evaluating the performance of a photolithography machine.

[0003] Currently, to achieve the required uniformity, a correction device is generally required in the optical path. Existing mainstream correction technologies primarily use mechanical structures or optical elements to partially block the illumination beam, directly modulating the light intensity distribution through attenuation to achieve uniformity. However, such intensity modulation-based schemes inevitably introduce significant light energy loss and are often accompanied by problems such as complex mechanical structures, difficult assembly and adjustment, high manufacturing costs, and limited long-term stability. Therefore, current illumination correction technology in lithography systems suffers from poor correction performance.

[0004] The above content is only used to help understand the technical solution of this application and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The main purpose of this application is to provide a method, system, equipment, medium and product for illumination correction of a lithography system, in order to solve the technical problem of poor correction effect.

[0006] To achieve the above objectives, this application proposes a method for illumination correction of a lithography system, the method comprising: The first light intensity of the calibration plane and the second light intensity of the wafer plane in the lithography system are collected, wherein the calibration plane is located in front of the variable slit of the illumination subsystem in the lithography system; Calculate the transmission factor between the correction plane and the wafer plane based on the first light intensity and the second light intensity; Based on the first light intensity, the transmission factor, and the preset illumination light intensity distribution, the target light intensity distribution of the wafer plane is iteratively adjusted to obtain the target phase distribution corresponding to the correction plane. The target phase distribution is used to determine the correction unit placed on the correction plane, and the correction unit is used to correct the illumination uniformity of the illumination light field corresponding to the lithography system.

[0007] In one embodiment, the step of iteratively adjusting the target light intensity distribution of the wafer plane based on the first light intensity, the transmission factor, and the preset illumination light intensity distribution to obtain the target phase distribution corresponding to the correction plane includes: Based on the first light intensity, the transmission factor, and the original phase distribution of the correction plane, a forward light field propagation calculation is performed to obtain the target light intensity distribution of the wafer plane, and the candidate phase distribution corresponding to the correction plane is solved based on the preset amplitude components. The candidate phase distribution is used as the new original phase distribution to iteratively update the target light intensity distribution of the wafer plane, and a joint evaluation function is calculated based on the target light intensity distribution. If the joint evaluation function meets the preset index, the original phase distribution corresponding to the target light intensity distribution is taken as the target phase distribution corresponding to the correction plane.

[0008] In one embodiment, the step of inversely solving the candidate phase distribution corresponding to the correction plane based on the preset amplitude components includes: The amplitude component corresponding to the first light intensity is replaced with a preset amplitude component, and the ideal light intensity distribution of the wafer plane is obtained based on the preset amplitude component. Based on the ideal light intensity distribution, the first light intensity, and the transmission factor, reverse light field propagation calculation is performed to obtain the candidate phase distribution corresponding to the correction plane.

[0009] In one embodiment, the step of calculating the joint evaluation function based on the target light intensity distribution includes: The ratio of the updated target light intensity distribution to the original target light intensity distribution is used as the diffraction efficiency. An error function is obtained based on the difference between the target light intensity distribution and the preset light intensity distribution; A joint evaluation function is generated based on the diffraction efficiency, the error function, and the corresponding preset weights.

[0010] In one embodiment, before the step of using the original phase distribution corresponding to the target light intensity distribution as the target phase distribution corresponding to the correction plane when the joint evaluation function satisfies a preset index, the method further includes: If the rate of change of the joint evaluation function is less than a preset change threshold, the joint evaluation function is determined to meet the preset index. If the rate of change of the joint evaluation function is not less than a preset change threshold, the joint evaluation function is determined to not meet the preset index.

[0011] In one embodiment, the step of calculating the transfer factor between the correction plane and the wafer plane based on the first light intensity and the second light intensity includes: The first light intensity and the second light intensity are deconvolved to obtain the transmission factor between the correction plane and the wafer plane.

[0012] Furthermore, to achieve the above objectives, this application also proposes a photolithography system, which includes a mercury lamp light source, an illumination subsystem, a mask, and a projection lens. The illumination subsystem includes a correction unit determined by the photolithography system illumination correction method described above. The correction unit is located in front of a variable slit in the illumination subsystem. The illumination beam emitted by the mercury lamp light source passes sequentially through the correction unit, the mask, and the projection lens in the illumination subsystem to reach the wafer plane.

[0013] In addition, to achieve the above objectives, this application also proposes an electronic device, the device comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement the steps of the lithography system illumination correction method as described above.

[0014] In addition, to achieve the above objectives, this application also proposes a storage medium, which is a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, it implements the steps of the lithography system illumination correction method described above.

[0015] In addition, to achieve the above objectives, this application also provides a computer program product, which includes a computer program that, when executed by a processor, implements the steps of the lithography system illumination correction method described above.

[0016] This application provides a method for illumination correction in a lithography system. The method includes: acquiring a first light intensity of a correction plane and a second light intensity of a wafer plane in the lithography system, wherein the correction plane is located in front of a variable slit in the illumination subsystem of the lithography system; calculating a transmission factor between the correction plane and the wafer plane based on the first light intensity and the second light intensity; iteratively adjusting a target light intensity distribution on the wafer plane based on the first light intensity, the transmission factor, and a preset illumination light intensity distribution to obtain a target phase distribution corresponding to the correction plane, wherein the target phase distribution is used to determine a correction unit placed on the correction plane, and the correction unit is used to correct the illumination uniformity of the corresponding illumination field in the lithography system.

[0017] This application obtains the current illumination state of the system by collecting light intensity distribution data of the correction plane and the wafer plane, providing a reliable input benchmark for subsequent modeling and optimization. This solves the problem of lacking accurate initial state information in the correction process. Based on the collected data, the spatial transmission factor of the light field from the correction plane to the wafer plane is calculated, and a physical model that accurately describes the beam propagation process is established. The complex transformation relationship of the optical system is quantified into a computable mathematical relationship, solving the problem that traditional empirical correction lacks theoretical model guidance and relies on repeated trial and error. Based on this transmission model, initial light intensity and target uniformity requirements, the target phase distribution required by the correction plane is solved and optimized through an iterative algorithm. The uniformity correction problem is transformed into a constrained phase optimization problem. The optimal solution is automatically sought through computer algorithms, solving the problems of limited degrees of freedom, insufficient accuracy and reliance on complex and precise motion control in traditional mechanical blocking correction methods. Compared to related solutions that mainly rely on mechanical components to block the beam for intensity modulation, this application adopts the principle of phase modulation, calculates and processes the target phase distribution of the correction unit, avoids the serious light energy loss caused by blocking in traditional solutions, greatly improves the energy utilization rate of the light source, and eliminates the need for complex multi-finger mechanical arrays and their precision motion control systems, simplifying the device structure, reducing manufacturing costs and assembly difficulty, and improving the long-term reliability of the system. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the photolithography system provided in Embodiment 1 of this application; Figure 2 This is a flowchart illustrating an embodiment of the illumination correction method for a lithography system in this application. Figure 3 This is a light intensity distribution diagram at the slit provided in Embodiment 1 of this application; Figure 4 A normalized percentage graph of brightness (light intensity) provided for Embodiment 1 of this application; Figure 5 This is a schematic diagram of the optical path architecture provided in Embodiment 1 of this application; Figure 6 This is a schematic diagram of the abstract model of light field propagation provided in Embodiment 1 of this application; Figure 7 This is a schematic diagram of the mathematical model for light field propagation provided in Embodiment 1 of this application; Figure 8 This is a schematic diagram illustrating the effect of the application correction unit provided in Embodiment 1 of this application; Figure 9 This is a flowchart illustrating Embodiment 2 of the lithography system illumination correction method of this application. Figure 10 This is an overall flowchart of the illumination correction method for a lithography system provided in Embodiment 2 of this application; Figure 11 This is a schematic diagram illustrating the algorithm implementation of the lithography system illumination correction method provided in Embodiment 2 of this application. Figure 12 This is a schematic diagram of the module structure of the illumination correction system of the lithography system in an embodiment of this application; Figure 13 This is a schematic diagram of the electronic device structure involved in the lithography system illumination correction method in the embodiments of this application.

[0021] The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0022] It should be understood that the first embodiment described herein is merely used to explain the technical solution of this application and is not intended to limit this application.

[0023] To better understand the technical solution of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0024] The main solution of the first embodiment of this application is as follows: acquiring the first light intensity of the calibration plane and the second light intensity of the wafer plane in the lithography system, wherein the calibration plane is located in front of the variable slit of the illumination subsystem in the lithography system; calculating the transmission factor between the calibration plane and the wafer plane based on the first light intensity and the second light intensity; iteratively adjusting the target light intensity distribution of the wafer plane based on the first light intensity, the transmission factor and the preset illumination light intensity distribution to obtain the target phase distribution corresponding to the calibration plane, wherein the target phase distribution is used to determine the calibration unit placed on the calibration plane, and the calibration unit is used to correct the illumination uniformity of the illumination light field corresponding to the lithography system.

[0025] In the first embodiment, for ease of description, the following description uses the photolithography system as the execution subject.

[0026] Existing technologies primarily achieve uniformity by directly attenuating and modulating the light intensity distribution through mechanical structures or optical elements that partially block the illumination beam. However, such intensity modulation-based schemes inevitably introduce significant light energy loss and are often accompanied by problems such as complex mechanical structures, difficult assembly and adjustment, high manufacturing costs, and limited long-term stability.

[0027] This application provides a solution that acquires the current illumination state of the system by collecting light intensity distribution data of the calibration plane and the wafer plane, providing a reliable input benchmark for subsequent modeling and optimization. This solves the problem of lacking accurate initial state information in the calibration process. Based on the acquired data, the spatial transmission factor of the light field from the calibration plane to the wafer plane is calculated, establishing a physical model that accurately describes the beam propagation process. The complex transformation relationship of the optical system is quantified into a computable mathematical relationship, solving the problem of traditional empirical calibration lacking theoretical model guidance and relying on repeated trial and error. Based on this transmission model, initial light intensity, and target uniformity requirements, the target phase distribution required by the calibration plane is solved and optimized through an iterative algorithm, transforming the uniformity calibration problem into a constrained phase optimization problem. The optimal solution is automatically sought through a computer algorithm, solving the problems of limited degrees of freedom, insufficient accuracy, and reliance on complex and precise motion control in traditional mechanical blocking methods. Compared to related solutions that mainly rely on mechanical components to block the beam for intensity modulation, this application adopts the principle of phase modulation, calculates and processes the target phase distribution of the correction unit, avoids the serious light energy loss caused by blocking in traditional solutions, greatly improves the energy utilization rate of the light source, and eliminates the need for complex multi-finger mechanical arrays and their precision motion control systems, simplifying the device structure, reducing manufacturing costs and assembly difficulty, and improving the long-term reliability of the system.

[0028] It should be noted that the executing entity in the first embodiment can be a computing service device with data processing, network communication, and program execution functions, such as a tablet computer, personal computer, mobile phone, or other electronic device, or a system, application, or program capable of implementing the above functions. The first embodiment and the following embodiments will be described using a lithography system as an example.

[0029] For example, to aid in understanding the technical concept or principles of this application, please refer to Figure 1 , Figure 1A schematic diagram of a lithography system is provided. The core of the lithography system is an illumination optical path, which includes a mercury lamp source (for generating the illumination beam), an illumination subsystem (for initially shaping the illumination beam), a mask (i.e., a template containing the target circuit pattern, uniformly illuminated), a projection lens (for reducing the mask pattern and projecting it onto the wafer plane), a correction unit (an optical element, such as a diffraction element, placed in the illumination optical path for phase modulation), and a wafer (which can be replaced by a camera during the correction stage; the camera lens is aligned with the imaging plane to collect the light intensity distribution on that plane to detect uniformity). The illumination subsystem contains a variable slit and an adjustable aperture stop to define the shape and size of the illumination light field. The illumination beam propagates from left to right. The illumination beam emitted by the mercury lamp source passes through the illumination subsystem and the projection lens to reach the wafer plane. The correction unit is placed in front of the variable slit in the illumination subsystem. A camera on the wafer plane performs uniformity detection to obtain the illuminance information of the lithography machine and obtain the illumination uniformity distribution of the wafer plane.

[0030] It should be noted that in the initial design stage, the correction unit does not actually exist in the lithography system. Instead, it is designed and fabricated based on the target phase distribution obtained after illumination correction in the lithography system, and then applied to the lithography system to correct the illumination integral uniformity of the illumination light field.

[0031] Based on this, embodiments of this application provide an illumination correction method for a lithography system, referring to... Figure 2 , Figure 2 This is a flowchart illustrating the first embodiment of the lithography system illumination correction method of this application.

[0032] In this embodiment, the illumination correction method for the photolithography system includes steps S01 to S03: Step S01: Acquire the first light intensity of the calibration plane in the lithography system and the second light intensity of the wafer plane in the lithography system, wherein the calibration plane is located in front of the variable slit of the illumination subsystem in the lithography system; It should be noted that the calibration plane refers to the virtual or physical plane selected for placing the calibration unit in the illumination optical path of the lithography machine. It is located in front of the variable slit of the lithography system and serves as the intervention point for phase modulation. The first light intensity refers to the spatial intensity distribution of the illumination beam measured or calculated at the calibration plane when the lithography system does not include the calibration unit; it characterizes the initial state of the original illumination beam emitted from the mercury lamp source at that location. The wafer plane refers to the imaging plane where the silicon wafer is located in the lithography process. It is also the target plane for achieving highly uniform illumination. The camera lens (photosensitive surface) can be used to simulate or replace the actual wafer position to non-destructively obtain the light intensity distribution. The second light intensity refers to the spatial intensity distribution of the illumination field measured at the wafer plane when the lithography system does not include the calibration unit; it reflects the initial performance of the current lithography system's illumination uniformity.

[0033] For example, to aid in understanding the technical concept or principles of this application, please refer to Figure 3 and Figure 4 , Figure 3 A light intensity distribution map at the slit is provided. Figure 4 A normalized percentage graph of brightness (luminous intensity) is provided. Figure 3 In lithography, the light field at the variable slit converges into the smallest spot size in the system. Therefore, adding a correction unit near the variable slit facilitates beam modulation and allows for the design of a smaller correction unit, thereby reducing costs. Figure 4 In the graph, the horizontal axis represents the position in the X direction, and the vertical axis represents the normalized light intensity (%). The curve shows the trend of light intensity decaying from the center to both sides, quantitatively revealing the non-uniformity in the X direction. Therefore, in photolithography scanning exposure, the uniformity of the scanning direction (defined as the y direction) in the illumination light field is better than that of the other direction (defined as the x direction), so only the x direction needs to be corrected.

[0034] Understandably, step S01 provides crucial initial state data for the entire calibration process by collecting the light intensity distribution between the calibration plane and the wafer plane. This solves the problem of unclear calibration benchmarks and reliance on operator experience caused by the lack of quantitative and full-field measurement of the current illumination state of the system in traditional calibration methods. It avoids calibration deviations caused by missing or inaccurate information and provides reliable data assurance for achieving high-precision calibration.

[0035] Step S02: Calculate the transmission factor between the correction plane and the wafer plane based on the first light intensity and the second light intensity; It should be noted that the transfer factor is a mathematical-physical model that describes the complex transformations that the light field undergoes as it propagates from the correction plane to the wafer plane. It encapsulates the combined effects of all optical elements (lenses, mirrors, slits, etc.) in between and is expressed as a spatially varying function (such as the point spread function or angular spectral transfer function).

[0036] In one feasible implementation, step S02 includes step A31: Step A01: Perform deconvolution processing on the first light intensity and the second light intensity to obtain the transmission factor between the correction plane and the wafer plane.

[0037] It should be noted that deconvolution is a mathematical method for signal or image processing. It refers to the reverse calculation process that uses the known input signal (the first light intensity of the correction plane) and the observed output signal (the second light intensity of the wafer plane) to solve the inverse calculation process that describes the response (transmission factor) of the lithography system.

[0038] For example, to aid in understanding the technical concept or principles of this application, please refer to Figure 5 , Figure 6 as well as Figure 7 , Figure 5 A schematic diagram of the optical path architecture is provided. Figure 6 A schematic diagram of an abstract model of light field propagation is provided. Figure 7 A schematic diagram of the mathematical model for light field propagation is provided. Figure 5 In the photolithography system, a light beam is emitted from a mercury lamp source, passes sequentially through the illumination subsystem and the variable slit, and then reaches the correction plane corresponding to the correction unit. The beam then illuminates the mask and forms an image through a projection lens. On the imaging surface (i.e., the wafer surface), a camera performs detection. The target surface and the wafer plane are then compared. (Surface) conjugate. In Figure 6 In the lithography system, the system from the calibration plane to the wafer is a linear, space-invariant system. The propagation of light from the calibration plane to the wafer is equivalent to performing a calculation on the first light intensity at the calibration plane to obtain the second light intensity. Therefore, the light field from... Surface spread to The process of surface-level transmission can be represented by the transmission factor G (transmission system), such as... Figure 7 As shown, U2(x,y) = O[U1(ζ,η)], where O[ ] is the operation of the transmission system on the input, and the operation of this system is the convolution of the light intensity distribution of the U1 surface with the transmission factor G, that is, U2=U1*G, where "*" represents the convolution symbol. When the correction unit is added, the distribution of the correction plane becomes U1xB, where "x" represents the multiplication sign, and the overall formula becomes U2=(U1xB)*G.

[0039] Specifically, the transmission factor G can be obtained by: detecting the light intensity of the calibration plane (first light intensity) and the light intensity of the wafer surface (second light intensity) using a camera in the physical object, and then performing deconvolution. For example: given U2=U1*G, perform a Fourier transform on both sides (F[ ] represents the Fourier transform, F-1[ ] represents the inverse Fourier transform), F[U2]=F[U1*G], this formula is equal to F[U2]=F[U1]xF[G], the form transformation gives F[G]=F[U2] / F[U1], then perform an inverse Fourier transform, F-1[F[G]]=F-1[F[U2] / F[U1]], the form transformation gives G=F-1[F[U2] / F[U1]]. Alternatively, the transmission factor G can also be directly calculated in the simulation model.

[0040] Understandably, step S02 establishes a precise mathematical model of light field propagation from the calibration plane to the wafer plane, solving the problem that existing technical solutions often rely on simplified optical assumptions or empirical formulas, which cannot accurately describe the actual transformation process of the light field within the illumination subsystem of the lithography machine. By using mathematical methods such as deconvolution, the actual transmission characteristics of the lithography system are derived from the measured light intensity, and the physical effects of the lithography system are transformed into calculable mathematical relationships. This provides a rigorous theoretical basis for the prediction of calibration effects and the design of phase distribution, thereby significantly improving the accuracy and reliability of calibration design and eliminating the reliance on repeated experimentation and debugging.

[0041] Step S03: Based on the first light intensity, the transmission factor and the preset illumination light intensity distribution, the target light intensity distribution of the wafer plane is iteratively adjusted to obtain the target phase distribution corresponding to the correction plane. The target phase distribution is used to determine the correction unit placed on the correction plane, and the correction unit is used to correct the illumination uniformity of the illumination light field corresponding to the lithography system.

[0042] It should be noted that the preset illumination intensity distribution is an ideal illumination intensity distribution expected to be achieved on the wafer plane, pre-set according to the requirements of the photolithography process. This can be a highly uniform distribution (e.g., uniformity higher than 98%), serving as the target for algorithm iterative optimization (improving the GS algorithm). The target intensity distribution is the estimated intensity distribution to be formed on the wafer plane, calculated in the current step during the iterative optimization process. It changes with the adjustment of the phase distribution of the correction plane in each iteration, continuously approximating the preset illumination intensity distribution. The target phase distribution is the spatial phase modulation function that needs to be implemented on the correction plane, ultimately solved by the iterative algorithm. It describes the precise phase delay amount required to be applied at each point on the correction plane to correct the initial non-uniform light field to the target uniform light field. It is the direct basis for fabricating the correction unit. The correction unit is a physical optical element fabricated according to the target phase distribution. It can be a diffractive optical element (DOE). When the correction unit is placed on the correction plane, it can apply the required spatial phase modulation to the transmitted illumination beam, thereby changing the light field propagation and ultimately achieving uniformity correction on the wafer plane. The illumination field is the spatial distribution of the intensity and phase of the light beam formed in the lithography system and ultimately reaching the wafer plane. Illumination uniformity refers to the consistency of the integrated energy of the illumination field on the wafer plane, especially in the lithography scanning direction. High uniformity (e.g., >98%) means that the exposure dose received at different locations on the silicon wafer is highly consistent, which is key to ensuring linewidth uniformity and pattern fidelity.

[0043] Additionally, it should be noted that after obtaining the target phase distribution of the correction unit, the design and fabrication scheme of the DOE (phase modulation element) needs to be formulated by comprehensively considering factors such as processing accuracy, beam modulation error, and energy loss. Finally, the illumination uniformity distribution obtained by the photolithography system using this correction unit on the wafer plane meets the uniformity requirements, and its calculation formula is as follows:

[0044]

[0045] Taking the x-direction as an example, This is the integral of the illumination intensity over the y-direction. These represent the maximum and minimum values ​​of the integrated intensity distribution of illumination in the x-direction, respectively. Let be the uniformity of the illumination integral in the x-direction. If If the uniformity index requirement is met (e.g., 98%), it indicates that the preparation of the correction unit is qualified.

[0046] For example, to aid in understanding the technical concept or principles of this application, please refer to Figure 8 , Figure 8 A schematic diagram of the effect of applying the correction unit is provided. The initial light intensity distribution represents the uncorrected and non-uniform illumination light field. After the light field is corrected by the correction unit, the corrected light intensity distribution is obtained. The uniformity of the corrected light intensity distribution is significantly improved compared with the initial distribution, thereby meeting the index requirements of the photolithography process.

[0047] Understandably, step S03 solves the target phase distribution through an iterative algorithm, transforming the uniformity correction problem into a mathematical optimization problem in the phase domain. This directly addresses the fundamental shortcomings of existing intensity modulation techniques (such as mechanical finger arrays or transmittance plates): achieving light field redistribution through phase modulation rather than intensity attenuation, thus avoiding huge light energy loss in principle. At the same time, it eliminates complex multi-degree-of-freedom mechanical motion mechanisms, using a single-piece diffractive optical element (DOE) as the final correction unit, greatly simplifying the system structure, reducing manufacturing, assembly, and failure rates, and achieving correction effects that surpass the precision of mechanical actuators through algorithms. This effectively solves the long-standing problem of balancing correction effect, energy efficiency, and system complexity in traditional solutions.

[0048] Based on the first embodiment of this application, in the second embodiment of this application, the content that is the same as or similar to the first embodiment described above can be referred to the above description, and will not be repeated hereafter. Based on this, please refer to... Figure 9 In step S03, the step of iteratively adjusting the target light intensity distribution of the wafer plane based on the first light intensity, the transmission factor, and the preset illumination light intensity distribution to obtain the target phase distribution corresponding to the correction plane includes steps S11 to S13: Step S11: Perform forward optical field propagation calculation based on the first light intensity, transmission factor and the original phase distribution of the correction plane to obtain the target light intensity distribution of the wafer plane, and solve the candidate phase distribution corresponding to the correction plane based on the preset amplitude components. It should be noted that the original phase distribution is an initially randomly set phase space distribution on the correction plane, serving as the starting point for the iterative algorithm. The forward optical field propagation calculation is based on the principle of optical field propagation. It uses the transmission factor to map the optical field of the correction plane (a complex function composed of the amplitude component of the first light intensity and the original phase distribution) to the wafer plane, thereby calculating the target light intensity distribution (i.e., the estimated light intensity of the wafer plane in the current iteration).

[0049] For example, the light intensity distribution on the wafer plane is an integral operation of the phase distribution of the correction plane, the illumination light intensity distribution, and the transmission factor, which can be expressed as:

[0050] in, This is represented on the wafer plane, with coordinates as follows: The complex amplitude light field distribution at the point, i.e., the second light intensity. This represents the target light intensity distribution to be calculated on the correction plane, with coordinates as follows: Complex amplitude light field distribution at point, This indicates that the coordinates on the correction plane are... The original phase distribution at the point, Indicates the transfer factor. Indicates the integration region.

[0051] Additionally, it should be noted that a hyperbolic initial phase form needs to be introduced initially for the original phase distribution. This hyperbolic initial phase form is based on hyperbolic functions (such as hyperbolic cosine, hyperbolic sine, etc.) to construct the original phase distribution. This phase distribution possesses unique mathematical properties, enabling specific interference and diffraction effects during beam propagation, thereby achieving precise control of the light field. It can be expressed as:

[0052] in, The original phase distribution is given, and b is a constant. To correct the plane coordinates.

[0053] In one feasible implementation, step S11, which involves resolving the candidate phase distribution corresponding to the correction plane based on the preset amplitude component, includes steps A01 to A02: Step A01: Replace the amplitude component corresponding to the first light intensity with a preset amplitude component, and obtain the ideal light intensity distribution of the wafer plane based on the preset amplitude component. It should be noted that the preset amplitude component is a predefined amplitude distribution expected to be achieved on the wafer plane based on the final illumination uniformity requirements. The amplitude is the square root of the light intensity, and the preset amplitude component corresponds to the amplitude shape of the ideal uniform light intensity. The candidate phase distribution is the phase distribution to be selected obtained through reverse optical field propagation calculation. This calculation aims at the ideal light intensity distribution (obtained by squaring the preset amplitude component), and combines the first light intensity and the transmission factor to inversely derive the phase distribution required to achieve this goal on the correction plane. The amplitude component is used to characterize the electric field intensity, and its squared value is the light intensity. In the iteration, the amplitude component is determined by the first light intensity during forward calculation and replaced by the preset amplitude component during reverse constraint. The ideal light intensity distribution is the spatial distribution of light intensity that is expected to be achieved on the wafer plane and meets the uniformity index (e.g., uniformity higher than 98%).

[0054] For example, the light intensity distribution on the wafer plane can be fitted as:

[0055] Where I represents the light intensity distribution at a point on the wafer plane, w is a constant parameter that determines the steepness of the Gaussian curve; the larger w is, the more concentrated the curve (the faster the light intensity decays); the smaller w is, the flatter the curve, and x is the abscissa of the slit plane (the Y direction can be considered almost unchanged). Adjusting the value of w can change the light intensity variation curve; when w is... When the light intensity curve is considered to meet the index and is regarded as the ideal light intensity distribution, it can be expressed as:

[0056] in, This represents an ideal light intensity distribution. This represents a specific target constant parameter, when determined. When the specific value is, the corresponding The curve represents the target distribution that meets the uniformity index of the photolithography process (e.g., uniformity > 98%).

[0057] Correspondingly, the relationship between light intensity and amplitude is squared, with a preset amplitude component. It can be represented as:

[0058] Additionally, it should be noted that in a photolithography system, there is a [missing information - likely referring to a specific distance or area] between the variable slit and the correction plane. The defocusing of Z corresponds to a linear change in light intensity; therefore, the light intensity distribution on the actual measured correction plane can be expressed as:

[0059] in, This represents the light intensity distribution measured on the calibration plane. Represents the abscissa of the correction plane. This represents the amplitude coefficient, reflecting the overall change in light intensity level caused by factors such as defocusing. This represents a constant parameter (this w has the same meaning as w in the wafer plane but a different value), which describes the steepness of the light intensity on the correction plane.

[0060] At this point, by combining the representation of the original phase distribution, the amplitude components of the corresponding correction plane can be obtained. for:

[0061] in, It is the phase part of the complex amplitude, where i is the imaginary unit, and Ψ=Ψ(ζ) is the spatial phase distribution function that needs to be solved by subsequent iterative algorithms. By solving for the optimal Ψ, the surface profile of the phase modulation element (DOE) can be determined.

[0062] Step A02: Perform reverse light field propagation calculation based on the ideal light intensity distribution, the first light intensity, and the transmission factor to obtain the candidate phase distribution corresponding to the correction plane.

[0063] It should be noted that the reverse optical field propagation calculation is a mathematical process that is the inverse of the forward calculation. It takes the target optical field of the wafer plane (such as the optical field corresponding to the ideal light intensity distribution) as input, uses the inverse model of the transmission factor to back-infer the correction plane, and solves for the possible phase distribution that can generate the target optical field.

[0064] Step S12: Use the candidate phase distribution as the new original phase distribution to iteratively update the target light intensity distribution on the wafer plane, and calculate the joint evaluation function based on the target light intensity distribution; It should be noted that the joint evaluation function is a scalar function used to comprehensively evaluate the performance of the iteration. It is composed of a linearly weighted combination of diffraction efficiency and error function. By optimizing this function, energy utilization and correction accuracy are balanced.

[0065] In one feasible implementation, step S02, the step of calculating the joint evaluation function based on the target light intensity distribution, includes steps A11 to A13: Step A11: The ratio of the updated target light intensity distribution to the original target light intensity distribution is taken as the diffraction efficiency. It should be noted that diffraction efficiency is the ratio of the total energy of the target light intensity distribution after the update to the total energy before the update in one iteration. This value reflects the light energy utilization rate in the phase modulation process. High efficiency (e.g., >95%) indicates small energy loss and is an important indicator that is superior to the traditional shading method.

[0066] For example, the diffraction efficiency can be expressed as:

[0067] in, Indicates diffraction efficiency. This represents the sum of the light intensity values ​​of all pixels (or sampling points) in the spatial light intensity distribution measured on the wafer plane when a correction unit is present; that is, the updated target light intensity distribution. This represents the sum of the light intensity values ​​of all pixels in the original spatial light intensity distribution measured on the wafer plane when there is no correction unit, i.e., the target light intensity distribution before the update.

[0068] Step A12: Obtain the error function based on the difference between the target light intensity distribution and the preset light intensity distribution; It should be noted that the error function is a mathematical measure that quantifies the difference between the target light intensity distribution obtained in the current iteration and the preset light intensity distribution. The smaller the value, the closer the uniformity is to the ideal state.

[0069] For example, the formula for calculating the error function is:

[0070] in, Let be the error function. That is, the amplitude portion of the preset light intensity distribution. The physical process of light field propagation from the correction plane to the wafer plane was simulated. This represents the complex amplitude distribution of the optical field on the correction plane (phase modulation plane). Indicates the transfer factor, therefore The overall calculation result is based on the current phase distribution. and light field propagation model The predicted complex amplitude value at a sampling point on a specific wafer surface (i.e., the amplitude on which the target light intensity distribution is based). The difference between the preset light intensity distribution and the currently calculated amplitude distribution (i.e., the target light intensity distribution) at every point in space was calculated, then squared (to eliminate positive and negative values ​​and amplify the difference), and finally summed over the entire plane (or discrete points) (Σ). This reflects the overall difference between the target light intensity distribution and the preset light intensity distribution. The larger the summed value, the greater the difference between the two, and the worse the uniformity correction effect. As a normalization factor, the error function becomes a relative error or a normalized mean square error, the magnitude of which is not affected by the absolute light intensity level, but only by the difference in the distribution shape, thus making the optimization process more stable.

[0071] Step A13: Generate a joint evaluation function based on diffraction efficiency, error function, and corresponding preset weights.

[0072] It should be noted that the preset weights are coefficients pre-assigned to the diffraction efficiency and error function when constructing the joint evaluation function. These weights determine the degree of emphasis on energy conservation and uniformity accuracy during the optimization process.

[0073] For example, the joint evaluation function can be expressed as:

[0074] in, For the joint evaluation function, For diffraction efficiency, Let K1 and K2 be the error function, and K1 and K2 be the preset weights corresponding to the diffraction efficiency and the error function, respectively.

[0075] Step S13: If the joint evaluation function meets the preset index, the original phase distribution corresponding to the target light intensity distribution is taken as the target phase distribution corresponding to the correction plane.

[0076] It should be noted that the preset index is the condition that the algorithm needs to meet to converge, such as the function value exceeding a certain threshold or the change being small enough.

[0077] For example, in When the light intensity distribution tends to stabilize, i.e., when the rate of change is less than a preset threshold, the original phase distribution corresponding to the target light intensity distribution is taken as the target phase distribution corresponding to the correction plane. The target light intensity distribution can be expressed as:

[0078] Where U1 represents the target light intensity distribution corresponding to the solved correction plane, and M represents a constant amplitude coefficient, which integrates factors such as the initial light intensity amplitude and energy conservation constraints during algorithm optimization, and determines the overall amplitude level of the corrected light field. This represents a constant parameter that describes the amplitude of the optical field along the correction plane. The width of the Gaussian distribution in the direction (usually corresponding to the scanning direction), Represents the abscissa of the correction plane. The amplitude component representing the complex amplitude has a Gaussian spatial distribution. The core of complex amplitude representation is the phase component. = (ξ,η) is the ultimate goal of the entire algorithm, namely the spatial phase distribution function. It is a bivariate function of the correction plane coordinates (ξ,η), which specifies the amount of phase delay that needs to be introduced at different positions on the component. Correspondingly, the target phase distribution is: B( ) =

[0079] Among them, B( The expression represents the phase distribution of the target, with a magnitude that is always 1, and its argument being the phase value. (ξ,η), (ξ,η) represents the phase value distribution, which is essentially a two-dimensional matrix or continuous function. It gives the additional phase offset (in radians) that needs to be introduced at each point (ξ,η) on the surface of the phase modulation element under normalized operating wavelength. For example, at a certain point... =π, which means that the phase of the transmitted light wave needs to be delayed by half a wavelength at this point.

[0080] In one feasible implementation, steps A21-A22 are included before step S13: Step A21: If the rate of change of the joint evaluation function is less than the preset change threshold, the joint evaluation function is determined to meet the preset index. It should be noted that the rate of change is the rate at which the joint evaluation function changes value between consecutive iterations during the iteration process. A smaller rate of change indicates that the optimization process is approaching stability and convergence. The preset change threshold is a positive decimal used to determine convergence. When the rate of change of the joint evaluation function is less than this threshold, the optimization is considered to have met the preset index, and the iteration can be terminated.

[0081] Step A22: If the rate of change of the joint evaluation function is not less than the preset change threshold, it is determined that the joint evaluation function does not meet the preset index.

[0082] In this embodiment, phase recovery is based on a physical model rather than mechanical trial and error, ensuring the scientific nature of the correction principle and fundamentally avoiding the randomness of mechanical occlusion. By comprehensively optimizing diffraction efficiency and reconstruction error, the contradiction between energy utilization and correction accuracy, which is difficult to balance in traditional methods, is resolved. The uniqueness and stability of the output phase solution are ensured by automatically determining the algorithm convergence through quantitative indicators, thus solving the problem of inconsistent correction effects caused by relying on human experience. This represents a leap from trial-and-error physical occlusion to deterministic digital phase design, thereby achieving higher accuracy and more stable and reliable uniformity correction effects while ensuring high light energy utilization.

[0083] For example, to aid in understanding the technical concept or principles of this application, please refer to Figure 10 and Figure 11 , Figure 10 A flowchart of the illumination correction method for a photolithography system is provided. Figure 11 A schematic diagram illustrating the algorithm implementation of the illumination correction method for a photolithography system is provided.

[0084] exist Figure 10 The process begins with collecting illuminance data from the lithography machine. Based on this data, the illumination integral uniformity of the current illumination field is calculated as a benchmark. Subsequently, this calculation result is compared with a preset illumination uniformity index to determine the correction target. An improved GS algorithm is applied for iterative optimization, and finally the phase distribution of the correction unit that can achieve the uniformity index is solved. Finally, the correction unit is designed and fabricated based on this phase distribution, thereby completing the fabrication of a phase modulation element that can be integrated into an actual lithography machine.

[0085] exist Figure 11 First, the light intensity data of surfaces U1 and U2 are acquired, and the transmission factor G of the system is obtained through deconvolution. The initial phase (i.e. the original phase distribution) B and the light intensity of surface U1 are used as inputs to enter the improved GS algorithm loop. In the loop, the algorithm adds formula updates to continue the calculation, generating a new phase distribution B of the correction unit, and then calculates the light intensity distribution of surface U2. The phase is updated through inverse transformation feedback. This iterative process continues until the target phase distribution B of the correction unit that meets the uniformity requirements is obtained.

[0086] It should be noted that the above examples are only for understanding this application and do not constitute a limitation on the illumination correction method of the lithography system of this application. Any simple modifications based on this technical concept are within the protection scope of this application.

[0087] This application also provides a photolithography system illumination correction system; please refer to... Figure 12 The lithography system illumination correction system includes: The light intensity acquisition module 10 is used to acquire the first light intensity of the calibration plane in the lithography system and the second light intensity of the wafer plane in the lithography system, wherein the calibration plane is located in front of the variable slit of the illumination subsystem in the lithography system; Data calculation module 20 is used to calculate the transmission factor between the correction plane and the wafer plane based on the first light intensity and the second light intensity; The iterative adjustment module 30 is used to iteratively adjust the target light intensity distribution of the wafer plane based on the first light intensity, the transmission factor and the preset illumination light intensity distribution to obtain the target phase distribution corresponding to the correction plane. The target phase distribution is used to determine the correction unit placed on the correction plane, and the correction unit is used to correct the illumination uniformity of the illumination light field corresponding to the lithography system.

[0088] The lithography system illumination correction system provided in this application, employing the lithography system illumination correction method described in the above embodiments, can solve the technical problem of poor correction effect. Compared with the prior art, the beneficial effects of the lithography system illumination correction system provided in this application are the same as those of the lithography system illumination correction method described in the above embodiments, and other technical features of the lithography system illumination correction system are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0089] This application provides an electronic device, which includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the lithography system illumination correction method in Embodiment 1 above.

[0090] The following is for reference. Figure 13 The diagram illustrates a structural schematic of an electronic device suitable for implementing embodiments of this application. The electronic devices in these embodiments may include, but are not limited to, mobile terminals such as mobile phones, laptops, and PADs (Portable Application Description: Tablet computers), as well as fixed terminals such as digital TVs and desktop computers. Figure 13 The electronic device shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments of this application.

[0091] like Figure 13 As shown, the electronic device may include a processing unit 1001 (e.g., a central processing unit, a graphics processing unit, etc.), which can perform various appropriate actions and processes according to a program stored in a read-only memory 1002 or a program loaded from a storage device 1003 into a random access memory 1004. The random access memory 1004 also stores various programs and data required for the operation of the electronic device. The processing unit 1001, the read-only memory 1002, and the random access memory 1004 are interconnected via a bus 1005. An input / output interface 1006 is also connected to the bus. Typically, the following systems can be connected to the input / output interface 1006: input devices 1007 including, for example, touchscreens, touchpads, keyboards, mice, image sensors, microphones, accelerometers, gyroscopes, etc.; output devices 1008 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; storage devices 1003 including, for example, magnetic tapes, hard disks, etc.; and communication devices 1009. The communication device 1009 allows the electronic device to communicate wirelessly or wiredly with other devices to exchange data. Although the diagrams show electronic devices with various systems, it should be understood that it is not required to implement or have all of the systems shown. More or fewer systems may be implemented alternatively.

[0092] Specifically, according to the embodiments disclosed in this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments disclosed in this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device, or installed from storage device 1003, or installed from read-only memory 1002. When the computer program is executed by processing device 1001, it performs the functions defined in the methods of the embodiments disclosed in this application.

[0093] The electronic device provided in this application, employing the lithography system illumination correction method described in the above embodiments, can solve the technical problem of poor correction effect. Compared with the prior art, the beneficial effects of the electronic device provided in this application are the same as those of the lithography system illumination correction method described in the above embodiments, and other technical features of this electronic device are the same as those disclosed in the method of the previous embodiment, and will not be repeated here.

[0094] It should be understood that the various parts disclosed in this application can be implemented using hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0095] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0096] This application provides a computer-readable storage medium having computer-readable program instructions (i.e., a computer program) stored thereon, the computer-readable program instructions being used to execute the lithography system illumination correction method in the above embodiments.

[0097] The computer-readable storage medium provided in this application may be, for example, a USB flash drive, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems or devices, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system or device. The program code contained on the computer-readable storage medium may be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination thereof.

[0098] The aforementioned computer-readable storage medium may be included in an electronic device or may exist independently without being assembled into an electronic device.

[0099] The aforementioned computer-readable storage medium carries one or more programs. When the aforementioned one or more programs are executed by an electronic device, the lithography system illumination correction device is used to acquire a first light intensity of the correction plane in the lithography system and a second light intensity of the wafer plane in the lithography system, wherein the correction plane is located in front of the variable slit of the illumination subsystem in the lithography system; calculate the transmission factor between the correction plane and the wafer plane based on the first light intensity and the second light intensity; iteratively adjust the target light intensity distribution of the wafer plane based on the first light intensity, the transmission factor and the preset illumination light intensity distribution to obtain the target phase distribution corresponding to the correction plane, wherein the target phase distribution is used to determine the correction unit placed on the correction plane, and the correction unit is used to correct the illumination uniformity of the corresponding illumination light field of the lithography system.

[0100] Computer program code for performing the operations of this application can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a Local Area Network (LAN) or a Wide Area Network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0101] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0102] The modules described in the embodiments of this application can be implemented in software or hardware. The names of the modules do not necessarily limit the functionality of the unit itself.

[0103] The readable storage medium provided in this application is a computer-readable storage medium that stores computer-readable program instructions (i.e., a computer program) for executing the above-described lithography system illumination correction method, thereby solving the technical problem of poor correction effect. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided in this application are the same as the beneficial effects of the lithography system illumination correction method provided in the above embodiments, and will not be repeated here.

[0104] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the lithography system illumination correction method described above.

[0105] The computer program product provided in this application can solve the technical problem of poor correction effect. Compared with the prior art, the beneficial effects of the computer program product provided in this application are the same as the beneficial effects of the lithography system illumination correction method provided in the above embodiments, and will not be repeated here.

[0106] The above description is only a part of the embodiments of this application and does not limit the patent scope of this application. All equivalent structural transformations made under the technical concept of this application and using the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included in the patent protection scope of this application.

Claims

1. A method for illumination correction in a photolithography system, characterized in that, The illumination correction method for the photolithography system includes: The first light intensity of the calibration plane and the second light intensity of the wafer plane in the lithography system are collected, wherein the calibration plane is located in front of the variable slit of the illumination subsystem in the lithography system; Calculate the transmission factor between the correction plane and the wafer plane based on the first light intensity and the second light intensity; Based on the first light intensity, the transmission factor, and the preset illumination light intensity distribution, the target light intensity distribution of the wafer plane is iteratively adjusted to obtain the target phase distribution corresponding to the correction plane. The target phase distribution is used to determine the correction unit placed on the correction plane, and the correction unit is used to correct the illumination uniformity of the illumination light field corresponding to the lithography system.

2. The illumination correction method for a photolithography system as described in claim 1, characterized in that, The step of iteratively adjusting the target light intensity distribution of the wafer plane based on the first light intensity, the transmission factor, and the preset illumination light intensity distribution to obtain the target phase distribution corresponding to the correction plane includes: Based on the first light intensity, the transmission factor, and the original phase distribution of the correction plane, a forward light field propagation calculation is performed to obtain the target light intensity distribution of the wafer plane, and the candidate phase distribution corresponding to the correction plane is solved based on the preset amplitude components. The candidate phase distribution is used as the new original phase distribution to iteratively update the target light intensity distribution of the wafer plane, and a joint evaluation function is calculated based on the target light intensity distribution. If the joint evaluation function meets the preset index, the original phase distribution corresponding to the target light intensity distribution is taken as the target phase distribution corresponding to the correction plane.

3. The illumination correction method for a photolithography system as described in claim 2, characterized in that, The step of inversely solving the candidate phase distribution corresponding to the correction plane based on the preset amplitude components includes: The amplitude component corresponding to the first light intensity is replaced with a preset amplitude component, and the ideal light intensity distribution of the wafer plane is obtained based on the preset amplitude component. Based on the ideal light intensity distribution, the first light intensity, and the transmission factor, reverse light field propagation calculation is performed to obtain the candidate phase distribution corresponding to the correction plane.

4. The illumination correction method for a photolithography system as described in claim 2, characterized in that, The step of calculating the joint evaluation function based on the target light intensity distribution includes: The ratio of the updated target light intensity distribution to the original target light intensity distribution is used as the diffraction efficiency. An error function is obtained based on the difference between the target light intensity distribution and the preset light intensity distribution; A joint evaluation function is generated based on the diffraction efficiency, the error function, and the corresponding preset weights.

5. The illumination correction method for a photolithography system as described in claim 2, characterized in that, Before the step of using the original phase distribution corresponding to the target light intensity distribution as the target phase distribution corresponding to the correction plane when the joint evaluation function satisfies the preset index, the method further includes: If the rate of change of the joint evaluation function is less than a preset change threshold, the joint evaluation function is determined to meet the preset index. If the rate of change of the joint evaluation function is not less than a preset change threshold, the joint evaluation function is determined to not meet the preset index.

6. The illumination correction method for a photolithography system as described in claim 1, characterized in that, The step of calculating the transfer factor between the correction plane and the wafer plane based on the first light intensity and the second light intensity includes: The first light intensity and the second light intensity are deconvolved to obtain the transmission factor between the correction plane and the wafer plane.

7. A photolithography system, characterized in that the photolithography system comprises: The system includes a mercury lamp light source, an illumination subsystem, a mask, and a projection lens. The illumination subsystem includes a correction unit as defined in the lithography system illumination correction method according to any one of claims 1 to 6. The correction unit is located in front of a variable slit in the illumination subsystem. The illumination beam emitted by the mercury lamp light source passes sequentially through the correction unit, the mask, and the projection lens in the illumination subsystem to reach the wafer plane.

8. An electronic device, characterized in that, The device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement the steps of the lithography system illumination correction method as described in any one of claims 1 to 6.

9. A storage medium, characterized in that, The storage medium is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by a processor, it implements the steps of the lithography system illumination correction method as described in any one of claims 1 to 6.

10. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by a processor, implements the steps of the lithography system illumination correction method as described in any one of claims 1 to 6.

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