A correction method, computer readable storage medium and lithographic machine

Abstract

The application provides a correction method, a computer readable storage medium and a photolithography machine. The photolithography machine comprises an illumination system, a mask, a lens combination component and a projection objective arranged along an optical axis, the mask has a specified exposure pattern, the lens combination component and the projection objective have a reference plane perpendicular to the optical axis, the reference plane has a plurality of measurement points arranged in dispersion, and the correction method comprises: making an illumination beam with a predetermined light intensity pass through the illumination system, the specified exposure pattern and the lens combination component in sequence, and irradiating the reference plane; acquiring a first actual exposure dose at each measurement point when a predetermined exposure time is reached; and correcting the illumination system according to the first actual exposure dose and a theoretical exposure dose of the reference plane corresponding to the predetermined light intensity and the predetermined exposure time. The application of the correction method can effectively improve the reliability of the performance of the illumination system, and further improve the photolithography effect of the photolithography machine.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor technology, specifically relating to a calibration method, a computer-readable storage medium, and a photolithography machine. Background Technology

[0002] In a lithography machine, the laser emitted by the laser source travels along the optical path of the illumination system to a predetermined position and exposes the wafer through a photomask.

[0003] The illumination system includes lenses or mirrors used to guide the laser beam. Due to the extremely high energy of the laser, the lenses or mirrors in the beam path are easily burned by the laser, causing performance degradation of the illumination system and affecting the imaging performance of the lithography machine. Therefore, a correction method for the illumination system is urgently needed to correct the system when it degrades, ensuring the lithography effect of the lithography machine. Summary of the Invention

[0004] The purpose of this invention is to provide a calibration method, a computer-readable storage medium, and a lithography machine, which are designed to calibrate an attenuating illumination system to ensure the lithography effect of the lithography machine.

[0005] To achieve the above objectives, the present invention provides a calibration method for a lithography machine; the lithography machine includes an illumination system, a mask, a lens assembly, and a projection lens arranged along its optical axis, the mask having a specified exposure pattern; a reference plane is provided between the lens assembly and the projection lens, the reference plane being perpendicular to the optical axis of the lithography machine, and having a plurality of dispersed measurement points on the reference plane; the calibration method includes:

[0006] An illumination beam with a predetermined light intensity is sequentially passed through the illumination system, the designated exposure pattern, and the lens assembly, and then illuminates the reference plane.

[0007] Obtain the first actual exposure dose at each of the measurement points during the predetermined exposure duration;

[0008] The illumination system is corrected based on all the first actual exposure doses and the theoretical exposure doses corresponding to the predetermined light intensity and the predetermined exposure duration on the reference plane;

[0009] The theoretical exposure dose is equal to I represents the predetermined light intensity; A represents the first influence factor of the unattenuated illumination system on the exposure dose on the reference plane; B represents the second influence factor of the specified exposure pattern on the exposure dose on the reference plane; and T represents the predetermined exposure duration.

[0010] Optionally, the value of the first impact factor is equal to , This represents the average value of the second actual exposure dose at each of the measurement points during the predetermined exposure duration when an illumination beam with the predetermined light intensity passes through the unattenuated illumination system and the lens assembly and illuminates the reference plane.

[0011] The value of the second impact factor is equal to , This represents the average value of the third actual exposure dose at each of the measurement points during the predetermined exposure duration when an illumination beam with the predetermined light intensity passes through the designated exposure pattern and the lens assembly and illuminates the reference plane.

[0012] Optionally, a light intensity measuring element is provided at each of the measurement points;

[0013] The step of obtaining the first actual exposure dose at each measurement point during the predetermined exposure duration includes:

[0014] Acquire the light intensity information measured by the light intensity measuring element at each of the measurement points;

[0015] The first actual exposure dose at the corresponding measurement point is obtained based on the predetermined exposure time and the light intensity information measured by each of the light intensity measuring elements.

[0016] Optionally, the step of correcting the illumination system based on all the first actual exposure doses and the theoretical exposure doses of the reference plane corresponding to the predetermined light intensity and the predetermined exposure duration includes:

[0017] Surface fitting is performed based on all the first actual exposure doses to obtain the actual exposure dose surface map;

[0018] Multiple correction points are selected on the actual exposure dose surface map, the number of correction points being greater than the number of measurement points, and each correction point has a fitted exposure dose;

[0019] Obtain a first difference between each fitted exposure dose and the theoretical exposure dose, as the correction dose at the corresponding correction point;

[0020] The lighting system is calibrated based on all of the stated calibration doses.

[0021] To achieve the above objectives, the present invention also provides a computer-readable storage medium having a program stored thereon, which, when executed, performs the correction method as described above.

[0022] To achieve the above objectives, the present invention also provides a lithography machine, including an illumination system, a mask stage, a lens assembly, a projection lens, light intensity measuring elements, and a control unit. The illumination system, the mask stage, the lens assembly, and the projection lens are arranged at intervals along the optical axis of the lithography machine. The mask stage is used to support a mask, which has a plurality of exposure patterns, one of which is a designated exposure pattern. A reference plane is provided between the lens assembly and the projection lens, the reference plane being perpendicular to the optical axis of the lithography machine. The reference plane has a plurality of measurement points, which are distributed dispersedly. The light intensity measuring elements are multiple, and are respectively arranged at the multiple measurement points. The control unit is communicatively connected to the multiple light intensity measuring elements and is configured to execute the correction method described above, wherein the first actual exposure dose at each measurement point is obtained based on the light intensity information measured by the corresponding light intensity measuring element.

[0023] To achieve the above objectives, the present invention also provides a calibration method for a lithography machine, the lithography machine including an illumination system, a mask, a lens assembly, and a projection lens arranged along its optical axis, the mask having a specified exposure pattern; a reference plane is provided between the lens assembly and the projection lens, the reference plane being perpendicular to the optical axis of the lithography machine, and the reference plane having a plurality of dispersed measurement points; the calibration method includes:

[0024] An illumination beam with a predetermined light intensity is sequentially passed through the illumination system, the designated exposure pattern, and the lens assembly, and then illuminates the reference plane.

[0025] Obtain the first actual exposure dose at each of the measurement points during the predetermined exposure duration;

[0026] Based on all the first actual exposure doses and the theoretical exposure doses corresponding to the predetermined light intensity and the predetermined exposure duration on the reference plane, it is determined whether the lighting system is attenuated. If so, the lighting system is corrected according to all the first actual exposure doses and the theoretical exposure doses.

[0027] The theoretical exposure dose is equal to I represents the predetermined light intensity; A represents the first influence factor of the unattenuated illumination system on the exposure dose on the reference plane; B represents the second influence factor of the specified exposure pattern on the exposure dose on the reference plane; and T represents the predetermined exposure duration.

[0028] Optionally, the step of determining whether the illumination system has attenuated based on all the first actual exposure doses and the theoretical exposure doses corresponding to the predetermined light intensity and the predetermined exposure duration on the reference plane includes:

[0029] Obtain a second difference between each of the first actual exposure doses and the theoretical exposure doses;

[0030] Determine whether each of the second differences is within a preset range;

[0031] If at least a portion of the second difference is not within the preset range, then the lighting system is determined to be attenuated.

[0032] If all of the second differences are within the preset range, then the lighting system is determined to be unaffected.

[0033] To achieve the above objectives, the present invention also provides a computer-readable storage medium having a program stored thereon, which, when executed, performs the correction method as described above.

[0034] To achieve the above objectives, the present invention also provides a lithography machine, including an illumination system, a mask stage, a lens assembly, a projection lens, light intensity measuring elements, and a control unit. The illumination system, the mask stage, the lens assembly, and the projection lens are arranged at intervals along the optical axis of the lithography machine. The mask stage is used to support a mask, which has a plurality of exposure patterns, one of which is a designated exposure pattern. A reference plane is provided between the lens assembly and the projection lens, the reference plane being perpendicular to the optical axis of the lithography machine. The reference plane has a plurality of measurement points, which are distributed dispersedly. The light intensity measuring elements are multiple, and are respectively arranged at the multiple measurement points. The control unit is communicatively connected to the multiple light intensity measuring elements and is configured to execute the correction method described above, wherein the first actual exposure dose at each measurement point is obtained based on the light intensity information measured by the corresponding light intensity measuring element.

[0035] Compared with the prior art, the calibration method, computer-readable storage medium, and lithography machine of the present invention have the following advantages:

[0036] The aforementioned calibration method is used in a lithography machine; the lithography machine includes an illumination system, a mask, a lens assembly, and a projection lens arranged along its optical axis, the mask having a specified exposure pattern; a reference plane is provided between the lens assembly and the projection lens, the reference plane being perpendicular to the optical axis of the lithography machine, and having a plurality of dispersed measurement points on the reference plane; the calibration method includes: passing an illumination beam with a predetermined light intensity sequentially through the illumination system, the specified exposure pattern, and the lens assembly, and illuminating the reference plane; obtaining a first actual exposure dose at each of the measurement points for a predetermined exposure duration; and calibrating the illumination system based on all the first actual exposure doses and a theoretical exposure dose corresponding to the predetermined light intensity and the predetermined exposure duration on the reference plane; the theoretical exposure dose is equal to... I represents the predetermined light intensity; A represents the first influence factor of the unattenuated illumination system on the exposure dose on the reference plane; B represents the second influence factor of the specified exposure pattern on the exposure dose on the reference plane; and T represents the predetermined exposure duration. By correcting the attenuated illumination system using the above method, the reliability of the illumination system's performance can be effectively improved, thereby improving the lithography effect of the lithography machine. Attached Figure Description

[0037] The accompanying drawings are provided to better understand the invention and are not intended to unduly limit the scope of the invention. Wherein:

[0038] Figure 1 This is a flowchart of the correction method provided by the present invention according to some embodiments;

[0039] Figure 2 This is a flowchart of the steps for obtaining the first influence factor used in the correction method provided by the present invention according to some embodiments;

[0040] Figure 3 This is a flowchart of the steps for obtaining the second influence factor used in the correction method provided by the present invention according to some embodiments;

[0041] Figure 4 This is a flowchart of the correction method provided by the present invention according to some other embodiments;

[0042] Figure 5 This is a partial structural schematic diagram of a lithography machine provided by the present invention according to some embodiments.

[0043] [The following are explanations of the reference numerals in the attached figures]: 10-Illumination system, 20-Mask stage, 30-Lens assembly, 40-Projection lens, 50-Workpiece stage, 60-Light source, 70-Light intensity measuring element, 80-Control unit, 01-Mask, 011-Exposure pattern, 0111-Specified exposure pattern, 02-Substrate, 100-Reference plane. Detailed Implementation

[0044] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show components related to the present invention and are not drawn according to the actual number, shape, and size of components in the actual implementation. In the actual implementation, the type, quantity, and proportion of each component can be arbitrarily changed, and the component layout may also be more complex.

[0045] Furthermore, while each embodiment described below possesses one or more technical features, this does not imply that users of the present invention must simultaneously implement all technical features in any embodiment, or can only separately implement some or all technical features in different embodiments. In other words, provided it is feasible, those skilled in the art can, based on the disclosure of the present invention and depending on design specifications or implementation requirements, selectively implement some or all technical features in any embodiment, or selectively implement a combination of some or all technical features in multiple embodiments, thereby increasing the flexibility in implementing the present invention.

[0046] As used herein, the singular forms “a,” “an,” and “the” include plural objects, and the plural form “a plurality” includes two or more objects, unless otherwise expressly indicated. As used herein, the term “or” is generally used to include the meaning of “and / or,” unless otherwise expressly indicated, and the terms “installed,” “connected,” and “linked” should be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral connection. Connections can be mechanical or electrical. Connections can be direct or indirect through an intermediate medium, and can be internal communication between two elements or an interaction between two elements. Relational terms such as “first,” “second,” etc., are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations, nor do they indicate or imply relative importance or implicitly specify the number of indicated technical features. Those skilled in the art will understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0047] To make the objectives, advantages, and features of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clearly illustrate the objectives of the embodiments of the present invention. The same or similar reference numerals in the drawings represent the same or similar parts.

[0048] One of the objectives of this embodiment is to provide a correction method, referred to as the first correction method, which is used in a lithography machine.

[0049] like Figure 5 As shown, the lithography machine includes an illumination system 10, a mask stage 20, a lens assembly 30, a projection lens 40, and a workpiece stage 50. The illumination system 10, mask stage 20, lens assembly 30, projection lens 40, and workpiece stage 50 are arranged at intervals along the optical axis of the lithography machine. The mask stage 20 supports a mask 01, on which an exposure pattern 011 is formed. The workpiece stage 50 supports a substrate 02. During lithography, an illumination beam passes sequentially through the illumination system 10, an exposure pattern 011, the lens assembly 30, and the projection lens 40 before reaching the substrate 02, optically transferring the corresponding exposure pattern 011 to the substrate 02, thus exposing the substrate 02.

[0050] In practice, the mask 01 has several exposure patterns 011. (Reference) Figure 5When performing the first correction method, any one of the exposure patterns 011 on the mask 01 is selected as the designated exposure pattern 0111. A reference plane 100 is defined in the lithography machine, and multiple measurement points (not marked in the figure) are defined on the reference plane 100. The reference plane 100 is located between the lens assembly 30 and the projection lens 40, and the reference plane 100 is perpendicular to the optical axis of the lithography machine. The multiple measurement points are distributed at different positions on the reference plane 100.

[0051] The flow of the first correction method is as follows: Figure 1 As shown, it includes:

[0052] Step S10: A light beam with a predetermined light intensity is sequentially passed through the illumination system 10, the designated exposure pattern 0111, and the lens assembly 30, and illuminates the reference plane 100.

[0053] Step S20: Obtain the first actual exposure dose at each of the measurement points during the predetermined exposure duration.

[0054] Step S30: The illumination system 10 is calibrated based on the first actual exposure dose at all the measurement points and the theoretical exposure dose of the reference plane 100 corresponding to the predetermined light intensity and the predetermined exposure duration. In this step, the value of the theoretical exposure dose is equal to... I represents the predetermined light intensity; A represents the first influence factor of the unattenuated illumination system 10 on the exposure dose; B represents the second influence factor of the specified exposure pattern 0111 on the exposure dose; and T represents the predetermined exposure duration.

[0055] The first correction method can correct the attenuation of the illumination system 10 while eliminating the interference of the projection lens 40 on the light intensity, thereby improving the illumination performance of the illumination system 10 and ensuring the lithography effect of the lithography machine. Furthermore, the correction method can be performed during the lithography operation of the lithography machine without stopping the machine, which helps to improve the production capacity of the lithography machine.

[0056] It should be noted that when the first correction method is performed during the photolithography process, the illumination beam with the predetermined light intensity is the illumination beam when the photolithography machine performs the photolithography operation; the specified exposure pattern 0111 is the pattern that needs to be transferred to the substrate 02 through exposure.

[0057] It is easy to understand that after the first correction method is completed, when the illumination beam with the predetermined light intensity is passed through the corrected illumination system 10, the designated exposure pattern 0111, and the lens assembly 30 in sequence and irradiates the reference plane 100, the second difference between the first exposure dose and the theoretical exposure dose at each measurement point during the predetermined exposure time is within a preset range.

[0058] It is also understandable that, for ease of calculation, the predetermined exposure duration can be set to a unit duration, thus the value of the theoretical exposure dose is equal to... .

[0059] The following section provides a detailed explanation of each step of the first correction method.

[0060] The illumination beam in step S10 is provided by a light source 60 (such as...). Figure 5 (As shown). The lithography machine may include the light source 60.

[0061] Optionally, such as Figure 5 As shown, a light intensity measuring element 70 is provided at each measurement point. Each light intensity measuring element 70 is configured to collect light intensity information at the corresponding measurement point. The light intensity information collected by each light intensity measuring element 70 is used to obtain the exposure dose at the corresponding measurement point. It should be understood that the light intensity measuring element 70 should not adversely affect the lithography operation of the lithography machine, and its specific setting position is determined by those skilled in the art based on experience or experiments.

[0062] When obtaining the first actual exposure dose, the light intensity information collected by the light intensity measuring element 70 is referred to as the first light intensity information. Furthermore, step S20 includes steps S21 and S22, where step S21 includes: obtaining the first light intensity information collected by each of the light intensity measuring elements 70; and step S22 includes: obtaining the first actual exposure dose at the corresponding measurement point based on each of the first light intensity information.

[0063] The calculation formula for step S22 is as follows: , This represents the first actual exposure dose at the measurement point. This represents the first light intensity information collected by the light intensity measuring element 70. When the predetermined exposure time T is a unit duration, .

[0064] Due to space limitations within the lithography machine, the number of measurement points is relatively small, resulting in a smaller number of first actual exposure doses obtained. Using a small number of first actual exposure doses to calibrate the illumination system 10 leads to relatively low accuracy.

[0065] In view of this, step S30 preferably includes the following steps S31, S32, S33 and S34.

[0066] Step S31 includes: performing surface fitting based on the first actual exposure dose at each of the measurement points to obtain the actual exposure dose surface map of the reference plane 100.

[0067] Step S32 includes selecting a plurality of correction points on the actual exposure dose surface map. The number of correction points is greater than the number of measurement points, and each correction point corresponds to a location point on the reference plane 100. It should be understood that each correction point has a fitted exposure dose.

[0068] Step S33 includes: obtaining a first difference between each fitted exposure dose and the theoretical exposure dose, and using the first difference as the correction dose at the corresponding correction point.

[0069] Step S34 includes: calibrating the lighting system 10 based on the calibration dose at each of the calibration points.

[0070] The execution of step S31 achieves the effect of obtaining the fitted exposure dose of all position points on the reference plane 100 with a smaller number of the first actual exposure doses. This allows for the selection of more position points as correction points, and the replacement of a smaller number of the first actual exposure doses with the fitted exposure doses of more of the correction points to correct the lighting system 10, effectively improving the accuracy of the correction.

[0071] In practice, step S31 can be performed using a multi-order function method. Alternatively, step S31 can also be performed using any other suitable surface fitting method from the mathematical field.

[0072] The number of correction points selected in step S32 is determined as needed. Generally, the more correction points there are, the higher the accuracy of the correction method, but the greater the subsequent computational load. In practice, the specific number of correction points should be determined while balancing the accuracy of the correction method and the computational load.

[0073] In step S33, the difference between each fitted exposure dose and the theoretical exposure dose can be directly calculated.

[0074] Step S34 includes adjusting the parameters of the illumination system 10 according to the correction dose at each of the correction points, until, after the correction method is completed, when the illumination beam with the predetermined light intensity passes sequentially through the corrected illumination system 10 and the designated exposure pattern 0111 and illuminates the reference plane 100 again, the second difference between the first exposure dose and the theoretical exposure dose at each of the measurement points is within a preset range. The specific method of adjusting the parameters of the illumination system 10 based on the correction dose at each of the correction points is well known to those skilled in the art and will not be elaborated here.

[0075] Further optionally, the first correction method further includes step S00, which includes: obtaining the theoretical exposure dose.

[0076] The specific operation of step S00 is as follows:

[0077] Step S01: Obtain the first influence factor.

[0078] Step S02: Obtain the second influence factor.

[0079] Step S03: Obtain the theoretical exposure dose based on the first influence factor, the second influence factor, the predetermined light intensity, and the predetermined exposure duration.

[0080] In this embodiment of the invention, the value of the first influence factor is equal to , The first average value of the second actual exposure dose at each of the measurement points during the predetermined exposure time is given when an illumination beam with the predetermined light intensity passes through the unattenuated illumination system 10 and the lens assembly 30 and illuminates the reference plane 100.

[0081] Accordingly, the specific operation of step S01 is as follows: Figure 2 As shown, it includes:

[0082] Step S011: An illumination beam with the predetermined light intensity is passed through the unattenuated illumination system 10 and the lens assembly 30, and illuminates the reference plane 100. In this step, the illumination beam does not pass through the designated exposure pattern 0111. In practice, this can be achieved by removing the mask 01 to prevent the illumination beam from passing through the designated exposure pattern 0111.

[0083] Step S012: Obtain the second actual exposure dose at each measurement point during the predetermined exposure duration. More specifically, first obtain the second light intensity information collected by each light intensity measuring element 70, and then obtain the second actual exposure dose at the corresponding measurement point based on each second light intensity information and the predetermined exposure duration. The specific calculation formula is as follows: ,in, This indicates the second actual exposure dose. This represents the second light intensity information. When the predetermined exposure time T is a unit duration, .

[0084] Step S013: Obtain the first average value based on the second actual exposure dose at each of the measurement points 110.

[0085] Step S014: Calculate the first influence factor based on the first average value and the predetermined light intensity.

[0086] The value of the second impact factor is equal to , This represents the second average value of the third actual exposure dose at each of the measurement points during the predetermined exposure duration when an illumination beam with the predetermined light intensity passes through the designated exposure pattern 0111 and the lens assembly 30 and illuminates the reference plane 100.

[0087] Accordingly, the specific operation of step S02 is as follows: Figure 3 As shown, it includes:

[0088] Step S021: An illumination beam with a predetermined light intensity passes through the designated exposure pattern 0111 and the lens assembly 30, and illuminates the reference plane 100. In this step, the illumination beam does not pass through the illumination system 10. In practice, the illumination beam can be prevented from passing through the illumination system 10 by removing or blocking it.

[0089] Step S022: Obtain the third actual exposure dose at each measurement point during the predetermined exposure duration. More specifically, first obtain the third light intensity information collected by each light intensity measuring element 70, and then obtain the third actual exposure dose at the corresponding measurement point based on each third light intensity information and the predetermined exposure duration. The specific calculation formula is as follows: ,in, This indicates the third actual exposure dose. This represents the third light intensity information. When the predetermined exposure time is a unit duration, .

[0090] Step S023: Obtain the second average value based on the third actual exposure dose at each of the measurement points 110.

[0091] Step S024: Calculate the second influence factor based on the second average value and the predetermined light intensity.

[0092] The calculation formula for step S03 is as follows: ,in This represents the theoretical exposure dose.

[0093] It is easy to understand that step S01 should be performed before the lighting system 10 has decayed, while steps S02 and S03 can be performed at any suitable time.

[0094] Furthermore, the lens assembly 30 primarily alters the direction and polarization of the illumination beam, with a relatively small impact on the light intensity of the illumination beam. Therefore, in this embodiment of the invention, the influence of the lens assembly 30 on the exposure dose on the reference plane 100 is not considered.

[0095] A second objective of this invention is to provide another correction method, referred to as the second correction method.

[0096] Figure 4 A flowchart of the second correction method is shown. Figure 4 As shown, the difference between the second correction method and the first correction method is that the second correction method includes not only steps S10, S20, and S30, but also step S40. Step S40 is performed after step S20 and includes: determining whether the illumination system 10 has attenuated based on the first actual exposure dose at each of the measurement points and the theoretical exposure dose of the reference plane 100 under the predetermined light intensity and the predetermined exposure duration. Step S30 is performed when the determination result of step S40 is "yes".

[0097] Of course, the second correction method may also include step S00.

[0098] A third objective of this invention is to provide a computer-readable storage medium storing a program that, when executed, performs either the first correction method described above or the second correction method described above.

[0099] The fourth objective of this embodiment is to provide a lithography machine, the partial structure of which is as follows: Figure 5As shown, the system includes the illumination system 10, the mask stage 20, the lens assembly 30, the projection lens 40, the light intensity measuring element 70, and a control unit 80. The specific arrangement of the illumination system 10, mask stage 20, lens assembly 30, projection lens 40, and light intensity measuring element 70 is as described above and will not be repeated here. The control unit 80 is communicatively connected to the light intensity measuring element 70 and is configured to perform either the first calibration method described above or the second calibration method described above.

[0100] While the present invention has been disclosed above, it is not limited thereto. Those skilled in the art can make various modifications and variations to the present invention without departing from its spirit and scope. Therefore, if such modifications and variations fall within the scope of the claims and their equivalents, the present invention also intends to include such modifications and variations.

Claims

1. A calibration method for a photolithography machine; characterized in that, The lithography machine includes an illumination system, a mask, a lens assembly, and a projection lens arranged along its optical axis. The mask has a specified exposure pattern. A reference plane is provided between the lens assembly and the projection lens. The reference plane is perpendicular to the optical axis of the lithography machine, and multiple measurement points are distributed on the reference plane. The calibration method includes: An illumination beam with a predetermined light intensity is sequentially passed through the illumination system, the designated exposure pattern, and the lens assembly, and then illuminates the reference plane. Obtain the first actual exposure dose at each of the measurement points during the predetermined exposure duration; The illumination system is corrected based on all the first actual exposure doses and the theoretical exposure doses corresponding to the predetermined light intensity and the predetermined exposure duration on the reference plane; The theoretical exposure dose is equal to I represents the predetermined light intensity; A represents the first influence factor of the unattenuated illumination system on the exposure dose on the reference plane; B represents the second influence factor of the specified exposure pattern on the exposure dose on the reference plane; and T represents the predetermined exposure duration.

2. The correction method according to claim 1, characterized in that, The value of the first impact factor is equal to , This represents the average value of the second actual exposure dose at each of the measurement points during the predetermined exposure time when an illumination beam with the predetermined light intensity passes through the unattenuated illumination system and the lens assembly and illuminates the reference plane; The value of the second impact factor is equal to , This represents the average value of the third actual exposure dose at each of the measurement points during the predetermined exposure duration when an illumination beam with the predetermined light intensity passes through the designated exposure pattern and the lens assembly and illuminates the reference plane.

3. The correction method according to claim 1, characterized in that, Each of the measurement points is equipped with a light intensity measuring element; The step of obtaining the first actual exposure dose at each measurement point during the predetermined exposure duration includes: Acquire the light intensity information measured by the light intensity measuring element at each of the measurement points; The first actual exposure dose at the corresponding measurement point is obtained based on the predetermined exposure time and the light intensity information measured by each of the light intensity measuring elements.

4. The correction method according to claim 1, characterized in that, The step of correcting the illumination system based on all the first actual exposure doses and the theoretical exposure doses corresponding to the predetermined light intensity and the predetermined exposure duration on the reference plane includes: Surface fitting is performed based on all the first actual exposure doses to obtain the actual exposure dose surface map; Multiple correction points are selected on the actual exposure dose surface map, the number of correction points being greater than the number of measurement points, and each correction point has a fitted exposure dose; Obtain a first difference between each fitted exposure dose and the theoretical exposure dose, as the correction dose at the corresponding correction point; The lighting system is calibrated based on all of the stated calibration doses.

5. A computer-readable storage medium having a program stored thereon, characterized in that, When the program is executed, the correction method as described in any one of claims 1-4 is performed.

6. A lithography machine, characterized in that, The lithography machine comprises an illumination system, a mask stage, a lens assembly, a projection lens, light intensity measuring elements, and a control unit. The illumination system, mask stage, lens assembly, and projection lens are arranged at intervals along the optical axis of the lithography machine. The mask stage carries a mask having several exposure patterns, one of which is a designated exposure pattern. A reference plane is provided between the lens assembly and the projection lens, perpendicular to the optical axis of the lithography machine. Multiple measurement points are distributed on the reference plane. Multiple light intensity measuring elements are arranged at the multiple measurement points. The control unit is communicatively connected to the multiple light intensity measuring elements and configured to execute the correction method as described in any one of claims 1-4, wherein the first actual exposure dose at each measurement point is obtained based on the light intensity information measured by the corresponding light intensity measuring element.

7. A calibration method for a photolithography machine; characterized in that, The lithography machine includes an illumination system, a mask, a lens assembly, and a projection lens arranged along its optical axis. The mask has a specified exposure pattern. A reference plane is provided between the lens assembly and the projection lens. The reference plane is perpendicular to the optical axis of the lithography machine, and multiple measurement points are distributed on the reference plane. The calibration method includes: An illumination beam with a predetermined light intensity is sequentially passed through the illumination system, the designated exposure pattern, and the lens assembly, and then illuminates the reference plane. Obtain the first actual exposure dose at each of the measurement points during the predetermined exposure duration; Based on all the first actual exposure doses and the theoretical exposure doses corresponding to the predetermined light intensity and the predetermined exposure duration on the reference plane, it is determined whether the lighting system has attenuated. If so, the lighting system is corrected according to all the first actual exposure doses and the theoretical exposure doses. The theoretical exposure dose is equal to I represents the predetermined light intensity; A represents the first influence factor of the unattenuated illumination system on the exposure dose on the reference plane; B represents the second influence factor of the specified exposure pattern on the exposure dose on the reference plane; and T represents the predetermined exposure duration.

8. The correction method according to claim 7, characterized in that, The step of determining whether the illumination system has attenuated based on all the first actual exposure doses and the theoretical exposure doses corresponding to the predetermined light intensity and the predetermined exposure duration on the reference plane includes: Obtain a second difference between each of the first actual exposure doses and the theoretical exposure doses; Determine whether each of the second differences is within a preset range; If at least a portion of the second difference is not within the preset range, then the lighting system is determined to be attenuated. If all of the second differences are within the preset range, then the lighting system is determined to be unaffected.

9. A computer-readable storage medium having a program stored thereon, characterized in that, When the program is executed, the correction method as described in claim 7 or 8 is performed.

10. A lithography machine, characterized in that, The system includes an illumination system, a mask stage, a lens assembly, a projection lens, light intensity measuring elements, and a control unit. The illumination system, the mask stage, the lens assembly, and the projection lens are arranged at intervals along the optical axis of the lithography machine. The mask stage is used to hold a mask, which has a plurality of exposure patterns, one of which is a designated exposure pattern. A reference plane is provided between the lens assembly and the projection lens, and the reference plane is perpendicular to the optical axis of the lithography machine. The reference plane has a plurality of measurement points, which are distributed dispersedly. There are multiple light intensity measuring elements, which are respectively arranged at the multiple measurement points. The control unit is communicatively connected to the multiple light intensity measuring elements and is configured to perform the correction method as described in claim 7 or 8, wherein the first actual exposure dose at each measurement point is obtained based on the light intensity information measured by the corresponding light intensity measuring element.

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