Photomask 2D measurement method and device

Abstract

The invention provides a photomask 2D measurement method and device, and the method comprises the steps: dividing a photomask scanning pattern, and obtaining at least two divided parts; overlapping the divided complete photomask scanning pattern with the photomask design pattern to obtain an RO (Reverse Osmosis Index) value of each divided part after division; and analyzing and comparing the difference between each divided part and the photomask design pattern to obtain the offset of each divided part. According to the method, the scanning pattern of the photomask is cut into a plurality of parts, the segmented pattern is compared with the design pattern of the photomask, which part CD of the specific pattern needs to be improved is clearly analyzed, and then modification is carried out by introducing MPC, so that the product quality is improved.

Description

Technical Field

[0001] This application relates to the technical field of photomask manufacturing, and particularly to a 2D measurement method and device for photomasks. Background Art

[0002] The CD (Critical Dimension) value reflects the degree of approximation between the pattern on the mask and the target design pattern. The closer the mask pattern is to the target design pattern, the better the pattern quality. For complex patterns, it becomes very difficult to use the one-dimensional CD value to reflect the quality of the mask pattern. Therefore, the miniaturization and complication of the patterns on the mask pose higher requirements for the measurement process, thus introducing 2D measurement.

[0003] Currently, the amount of EPE data output solely by 2D measurement software is extremely large, which is not conducive to the analysis of complex patterns. Therefore, the effect of the CD measurement value of the photomask is not good.

[0004] Therefore, a new 2D measurement scheme for photomasks is needed. Summary of the Invention

[0005] In view of this, the embodiments of this specification provide a 2D measurement method and device for photomasks.

[0006] The embodiments of this specification provide the following technical solutions:

[0007] The embodiments of this specification provide a 2D measurement method for photomasks, including:

[0008] Dividing the scanned pattern of the photomask to obtain at least two divided parts after division;

[0009] Superimposing the complete scanned pattern of the photomask after division with the design pattern of the photomask to obtain the region of interest for each divided part after division;

[0010] Analyzing and comparing the differences between each divided part and the design pattern of the photomask to obtain the offset of each divided part.

[0011] The embodiments of this specification also provide a 2D measurement device for photomasks, including:

[0012] A dividing module for dividing the scanned pattern of the photomask to obtain at least two divided parts after division;

[0013] An obtaining module for superimposing the complete scanned pattern of the photomask after division with the design pattern of the photomask to obtain the region of interest for each divided part after division;

[0014] An analyzing module for analyzing and comparing the differences between each divided part and the design pattern of the photomask to obtain the offset of each divided part.

[0015] An embodiment of this specification further provides an electronic device, including: a memory, a processor, and a computer program. The computer program is stored in the memory, and the processor runs the computer program to execute the optical mask 2D measurement method described in the above technical solution.

[0016] Compared with the prior art, the beneficial effects that can be achieved by at least one of the above technical solutions adopted in the embodiments of this specification at least include:

[0017] This application provides an optical mask 2D measurement method. After dividing the optical mask scanning pattern, it is superimposed and compared with the optical mask design pattern. By clarifying which part of the CD needs to be improved after specific division, targeted improvement is carried out by introducing MPC to improve product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of this application, the drawings required for the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of this application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 is a schematic diagram of 2D measurement of an optical mask provided by the prior art;

[0020] Figure 2 is a schematic diagram of 2D measurement of an optical mask provided by an embodiment of this specification Figure 1 ;

[0021] Figure 3 is a schematic diagram of 2D measurement of an optical mask provided by an embodiment of this specification Figure 2 ;

[0022] Figure 4 is a schematic diagram of 2D measurement of an optical mask provided by an embodiment of this specification Figure 3 ;

[0023] Figure 5 is a flowchart of the optical mask 2D measurement method provided by an embodiment of this specification;

[0024] Figure 6 is a schematic diagram of 2D measurement of an optical mask provided by the prior art Figure 2 ;

[0025] Figure 7 A schematic diagram of 2D measurement of an optical mask provided by an embodiment of this specification Figure 3 . DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The embodiments of this application will be described in detail below with reference to the drawings.

[0027] The following describes the embodiments of the present application through specific examples. Those skilled in the art can easily understand the other advantages and effects of the present application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all embodiments. The present application can also be implemented or applied through other different specific embodiments. 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 application. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without making creative efforts belong to the scope of protection of the present application.

[0028] It should be noted that the following describes various aspects of the embodiments within the scope of the appended claims. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is illustrative only. Based on the present application, those skilled in the art should understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspects described herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using other structures and / or functions in addition to one or more of the aspects described herein.

[0029] It should also be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present application schematically. The diagrams only show the components related to the present application, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in its actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0030] In addition, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the examples can be practiced without these specific details.

[0031] CD measurement is crucial for photomask manufacturing because the quality and accuracy of the mask directly affect the quality of the lithography process and the performance of the final chip. With the development of semiconductor technology, the requirements for the accuracy and efficiency of CD measurement are also getting higher and higher to meet more advanced process nodes and smaller feature sizes.

[0032] Therefore, the inventor found that using only one-dimensional CD values cannot well reflect the quality of the mask pattern. Therefore, 2D measurement software is used for processing. Traditionally, it is mainly processed through EPE. However, it is found that due to the increasing complexity of the corresponding patterns on the photomask and the relatively difficult control of its production process, the amount of EPE data output by only 2D measurement software is very large, which is not conducive to the analysis of complex patterns.

[0033] As Figure 1 shown, the X-axis represents the range of EPE, and the Y-axis represents the number of EPE. Currently, this method cannot show which part of the pattern is well made and which part is poorly made. It is impossible to specifically know which part of the scanned pattern of the photomask is worse than the designed pattern of the photomask, and thus it is impossible to perform MPC adjustment to improve the quality of the product.

[0034] In view of this, the embodiments of this specification provide a new 2D measurement method for photomasks, which cuts the scanned pattern of the photomask into several parts, compares the segmented pattern with the designed pattern of the photomask, clearly analyzes which part of the specific pattern needs to improve the CD, and then modifies it by introducing MPC to improve the quality of the product.

[0035] The following describes the technical solutions provided by the embodiments of this application with reference to the accompanying drawings.

[0036] Among them, the explanations of the professional terms in the embodiments of this specification are as follows:

[0037] Critical Dimension (CD for short): In the manufacturing process of a photomask (reticle or mask), it refers to the actual linear dimension of the critical pattern features on the mask. These dimensions are crucial for ensuring the accurate transfer of patterns to the wafer during the lithography process.

[0038] AEPE (Average Edge Placement Error): Average Edge Placement Error, which refers to the average deviation between the actual position and the designed target position of the edge of the mask pattern. It is used to evaluate the accuracy of the mask pattern. The smaller the AEPE, the closer the mask pattern is to the designed target and the higher the lithography imaging quality.

[0039] MtT (Mean-to-Target): The average deviation of the critical dimension of the mask relative to the target dimension. It is used to measure the accuracy of the critical dimension during the mask manufacturing process, help adjust the manufacturing process, and ensure that the dimensions of the mask pattern meet the design requirements.

[0040] MPC (Mask Process Correction): Mask Process Correction. By optimizing and correcting the mask pattern, it compensates for possible process deviations during the lithography process, improving the accuracy and consistency of lithography imaging.

[0041] EPE (Edge Placement Error): Edge Placement Error refers to the difference between the contour obtained from model simulation and the target contour. EPE is an important indicator in lithography process optimization, used to evaluate the accuracy of lithography patterns. The smaller the EPE, the closer the exposed pattern is to the target pattern.

[0042] CD SEM (Critical Dimension Scanning Electron Microscope): Critical Dimension Scanning Electron Microscope. It is used to measure the critical dimensions of lithography patterns, such as line width, pitch, etc. CD SEM can provide accurate measurement results at the sub-nanometer level, helping to calibrate lithography machines and process technologies.

[0043] ROI (Region of Interest): Region of Interest. In photomask manufacturing and inspection, ROI refers to the area that needs to be focused on and measured, usually containing critical patterns or areas that may have problems.

[0044] It should be noted that with the miniaturization of semiconductor product size requirements, the miniaturization and complexity of patterns on photomasks pose higher requirements for the measurement process. It is not only necessary to detect whether the pattern is complete, such as the existence of defects, etc., but also to detect the consistency and accuracy of pattern dimensions.

[0045] Currently, for 2D measurement, the EPE data volume of the entire pattern directly output by software is too large, and it is not intuitive to clearly identify which part of the pattern has a large CD difference from the design, especially for complex patterns, it is difficult to control product quality.

[0046] Such as Figure 2 and Figure 5 For example, the embodiments of this specification provide a 2D measurement method for photomasks, including steps S401 - S403. Step S401: Divide the scanned pattern of the photomask to obtain at least two divided parts. Step S402: Superimpose the complete scanned pattern of the photomask after division with the photomask design pattern to obtain the ROI value of each divided part after division. Step S403: Analyze and compare the differences between each divided part and the photomask design pattern to obtain the offset of each divided part.

[0047] Specifically, a photomask usually uses quartz glass as the substrate, with a metal chromium layer covering the surface as the light-shielding layer, and there is also a layer of chromium oxide on the chromium layer as the anti-reflection layer. This special material structure causes the imaging of the photomask scanned image to be significantly affected by the optical properties of the material, such as light reflection, absorption, and diffraction effects.

[0048] In addition, since the line widths and spacings of photomasks are very small, approaching or less than the wavelength of the lithography machine, the diffraction phenomenon of light will cause image edge distortion and resolution reduction. Photomasks are used in high-precision lithography processes. For example, the line widths and spacings on photomasks need to strictly meet the nanometer level, otherwise it will cause defects in chip manufacturing, etc.

[0049] Therefore, due to the special physical structure, optical characteristics, and high-precision requirements of the photomask scanning pattern, the amount of EPE data output by software for the entire photomask scanning pattern in the prior art is too large, resulting in poor measurement effects of photomasks. That is, the photomask scanning pattern is relatively complex, and the production process is relatively difficult to control, resulting in poor measurement effects of photomasks.

[0050] In step S401, to evaluate the quality of the photomask, two-dimensional dimensions and shapes of the photomask pattern are measured and analyzed to ensure its high consistency and high fidelity with the designed pattern.

[0051] It should be noted that the main content of photomask 2D measurement includes graphic fidelity evaluation. Therefore, two-dimensional measurement needs to be used for more comprehensive analysis. In the analysis of the entire photomask area, deviations in dimensions and shapes of the graphics need to be qualitatively analyzed. Considering the above-described particularities of photomasks, etc., the present invention divides the photomask scanning pattern (such as a CD SEM image), that is, divides the entire photomask scanning pattern into smaller unit parts for subsequent targeted evaluation of each divided part.

[0052] Among them, the division of the photomask scanning pattern includes division according to the graphic features of the photomask design pattern. For example, each divided part after division can contain complete line widths, spacings, etc., or division according to the symmetry of the size of the photomask scanning pattern, etc.

[0053] As Figure 2 shown in (b) of , the CD SEM image is divided into 4 parts, which can facilitate highlighting which area of the graphic has a greater data difference when two graphics are superimposed, and is more conducive to subsequent CD adjustment.

[0054] In step S402, based on the division to obtain each part, the complete photomask scanning pattern after division is superimposed with the photomask design pattern to obtain the ROI value of each divided part after division.

[0055] The embodiments of this specification not only divide the photomask scanning pattern, but also superimpose the divided pattern with the photomask design pattern to obtain the region of interest of each divided part after division, so as to obtain differences for each divided part. That is, by dividing the graphic and obtaining differences, it is possible to specifically obtain which part of the CDSEM has a larger difference from the design.

[0056] Combined with the above embodiments, as Figure 2 shown in (c) of

[0057] In step S403, for the regions of interest of each divided part, analyze and compare the differences between each divided part and the photomask design pattern, so as to clarify the differences between the CD of each part of the pattern and the design pattern, and then perform MPC adjustment on the CD abnormal pattern to optimize the product quality.

[0058] Combined with the above embodiments, compare and analyze the values of these four parts of ROI, that is, clarify the differences between the CD of each part of the pattern and the design pattern, and then specifically obtain which part of the photomask scanning pattern is poorly made, so as to perform MPC adjustment on the CD abnormal pattern to improve production efficiency and product quality.

[0059] In some embodiments, the AEPE value or MtT value corresponding to each divided part is obtained through measurement software. According to the AEPE value, the closeness between the measured photomask and the photomask design pattern is reflected. According to the MtT value, the large or small offset of each divided part relative to the photomask design pattern is reflected. Among them, the measurement software includes tools for the semiconductor manufacturing and detection fields, etc.

[0060] The present invention uses the segmentation method to divide the pattern into multiple parts, and by comparing and analyzing the output AEPE and MtT data, to clarify how much the CD at which position of the complex pattern differs from the design, and then the quality of the product can be optimized by adjusting the MPC. For example, the CD SEM image is divided into 4 parts, and the CD SEM is superimposed on the design, and the values of four parts of ROI can be obtained. By comparing and analyzing the values of these four parts, the differences between the CD of each part of the pattern and the design pattern are clarified, and MPC adjustment is performed on the CD abnormal pattern to optimize the product quality.

[0061] In other words, the new solution of the present invention uses the segmentation method to divide the pattern into multiple parts compared with the traditional method, and superimposes the segmented CD SEM image on the design pattern, and then by comparing and analyzing the output AEPE and MtT data, to clarify how much the CD at which position of the complex pattern differs from the design pattern, and then the quality of the product can be optimized by adjusting the MPC.

[0062] That is, the present invention mainly divides the pattern into multiple parts by the segmentation method, and the measurement software can output the AEPE and MtT values of these four parts.

[0063] Under normal circumstances, the smaller the AEPE value (the closer it is to 0), the closer it is to the design; and the positive or negative value of the MtT value can be used to determine whether the graphic is larger or smaller than the design. If MtT is a negative value, it means that the actual graphic is smaller; if MtT is a positive value, it means that the actual graphic is larger. Based on this, it can be clearly determined which area of ​​the graphic CD needs to be compensated. By adjusting the MPC for this part, a graphic close to the design CD can be obtained, thereby improving product quality.

[0064] like Figure 3 As shown in (b) and (c) in , it can be determined that the graphics are larger than the design; Figure 4 As shown in (b) and (c) in the figure, it can be determined that the graphic is smaller than the design.

[0065] in, Figures 2 - 4 The examples (a), (b), and (c) in each figure are superposition processes. Part (a) is the photomask design pattern (i.e., design image), part (b) is the CD SEM image, and part (c) is the result of superimposing the CD SEM and the design. Figure 2 This is an example of superimposing the CDSEM image and the design image to show that the image is normal. Figure 3 This is an example of a region being enlarged after the CD SEM image and the design image are superimposed. Figure 4 This is an example of a region being reduced after the CD SEM image and the design image are superimposed.

[0066] The traditional method uses EPE to process, but the amount of EPE data is too large to be analyzed. Figure 6 As shown, for more complex graphics, EPE is used for processing. Even if the photomask scan pattern is directly superimposed with the design pattern, the part with graphic differences cannot be accurately obtained, that is, it is impossible to tell which part of the specific graphic is poorly made.

[0067] Therefore, the present application divides the photomask scanning pattern, such as Figure 7 The example is divided into multiple parts. Taking 4 parts as an example, the overall photomask scanning pattern after segmentation is superimposed with the photomask design pattern, which leads to the use of AEPE and MtT for analysis. According to the AEPE and MtT values, if it is found after segmentation that ROI2 and ROI4 (this part of the graph is more complex) are relatively poor, it can be determined that ROI2 and ROI4CD are too large, and then MPC adjustment is performed according to the difference in this part to optimize product quality.

[0068] In some embodiments, the method further includes: dividing the photomask scan pattern according to the pattern features of the photomask design pattern.

[0069] In the embodiments of this specification, the optical mask scanning pattern is segmented, that is, divided into multiple divided parts. The main function is to compare with the optical mask design pattern subsequently, and more specifically obtain the differences of each divided part. That is, by introducing the segmentation of the optical mask scanning pattern and the superposition of the CDSEM pattern and the design pattern, a more important function is to understand which specific part of the CDSEM pattern has a large difference from the design pattern and the specific size of the difference.

[0070] Therefore, the division of the optical mask scanning pattern includes equal division or symmetric division, that is, the optical mask scanning pattern is symmetrically bisected along the horizontal or vertical direction. It can also be divided according to the specific characteristics or design requirements of the pattern, that is, according to the pattern characteristics of the optical mask design pattern. For example, it can be divided by functional area: if the pattern contains different functional modules (such as different circuit areas in the mask), it can be divided according to the boundaries of the functional modules. Or it can be divided by pattern characteristics: local area division is performed on specific parts (such as lines, holes, edges, etc.) of complex patterns. In addition, it can also be automatically divided according to the measurement software algorithm, such as divided by edge detection algorithm or clustering algorithm, etc.

[0071] Compared with the prior art, the present invention divides the pattern into multiple parts, which can clearly analyze which part of the specific pattern needs to improve the CD, and modifies it by introducing MPC, thereby improving the product quality.

[0072] In some embodiments, it also includes modifying the offset of each divided part by introducing MPC.

[0073] Among them, MPC is a process technology for optimizing mask patterns. By adjusting the size or shape of the mask pattern, it compensates for process deviations during the manufacturing process, making the finally manufactured pattern closer to the design target.

[0074] Combined with the above embodiments, through the AEPE and MtT values, clarify the pattern deviation situation of each segmented part and determine which areas need to be corrected. If the MtT is negative, it means the pattern is made too small and the pattern size needs to be increased through MPC. If the MtT is positive, it means the pattern is made too large and the pattern size needs to be reduced through MPC.

[0075] It is also possible to prioritize the areas that need to be corrected according to the magnitudes of the AEPE and MtT values, and give priority to correcting the areas with larger deviations.

[0076] In some embodiments, it also includes obtaining a correction scheme for the corresponding part of the lines, aperture diameters, and spacings on the mask according to the offset of each divided part.

[0077] Combined with the above embodiments, after obtaining the offsets of each divided part specifically, according to the AEPE and MtT values, determine the correction direction and correction amount for each segmentation (i.e., division) part. During the correction process, it is also necessary to consider whether the influence of the local correction of each divided part will affect the adjacent areas, and it is also necessary to consider that the entire mask pattern is reconstituted by each corrected divided part to ensure the fidelity and consistency of the overall pattern. In some embodiments, through considering the global and local influences, multiple verifications and adjustments can be carried out, and through iterative optimization, the correction scheme is gradually improved to ensure that the final pattern is consistent with the designed pattern.

[0078] For line width correction, if the MtT value is negative, it indicates that the line width is less than the designed value, and the line width needs to be increased through MPC. If the MtT value is positive, it indicates that the line width is greater than the designed value, and the line width needs to be decreased through MPC. The correction amount can be determined according to the absolute value of the MtT value. For example, an MtT value of -10 nm means that the line width needs to be increased by 10 nm. Another example is for aperture correction. If the MtT value of the aperture is negative, it indicates that the aperture is less than the designed value, and the aperture needs to be increased through MPC. If the MtT value of the aperture is positive, it indicates that the aperture is greater than the designed value, and the aperture needs to be decreased through MPC. The correction amount is also determined according to the absolute value of the MtT value. Still another example is for pitch correction. If the MtT value of the pitch is negative, it indicates that the pitch is less than the designed value, and the pitch needs to be increased through MPC. If the MtT value of the pitch is positive, it indicates that the pitch is greater than the designed value, and the pitch needs to be decreased through MPC. The correction amount is determined according to the absolute value of the MtT value. For example, an MtT value of +15 nm means that the pitch needs to be decreased by 15 nm.

[0079] The embodiments of this specification also provide an optical mask 2D measurement device, which includes:

[0080] A division module, configured to divide the scanned pattern of the optical mask to obtain at least two divided parts after division;

[0081] An obtaining module, configured to superimpose the complete scanned pattern of the optical mask after division with the designed pattern of the optical mask to obtain the region of interest of each divided part after division;

[0082] An analysis module, configured to analyze and compare the differences between each divided part and the designed pattern of the optical mask to obtain the offset of each divided part.

[0083] This device can correspondingly be used to execute Figure 5 the steps in the method embodiments shown, and its implementation principle and technical effects are similar, so they will not be elaborated here.

[0084] An electronic device provided by the embodiments of this specification, the electronic device includes: a processor, a memory, and a computer program; where

[0085] A memory for storing the computer program, which can also be a flash memory. The computer program is, for example, an application program, a functional module, etc. that implements the above method.

[0086] A processor for executing the computer program stored in the memory to implement each step performed by the device in the above method. For details, reference can be made to the relevant descriptions in the foregoing method embodiments.

[0087] Optionally, the memory can be either independent or integrated with the processor.

[0088] When the memory is a device independent of the processor, the device may further include:

[0089] A bus for connecting the memory and the processor.

[0090] This application also provides a readable storage medium, in which a computer program is stored. When the computer program is executed by a processor, it is used to implement the methods provided by the above various embodiments.

[0091] Among them, the readable storage medium can be a computer storage medium or a communication medium. A communication medium includes any medium that facilitates the transmission of a computer program from one place to another. A computer storage medium can be any available medium that can be accessed by a general-purpose or special-purpose computer. For example, the readable storage medium is coupled to the processor, so that the processor can read information from the readable storage medium and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can be located in an application specific integrated circuit (ASIC). In addition, the ASIC can be located in a user device. Of course, the processor and the readable storage medium can also exist as discrete components in a communication device. The readable storage medium can be a read-only memory (ROM), a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, etc.

[0092] For the same or similar parts among the various embodiments in this specification, reference can be made to each other. Each embodiment focuses on the differences from other embodiments. In particular, for the product embodiments described later, since they correspond to the methods, the descriptions are relatively simple, and for the relevant parts, reference can be made to the partial descriptions of the system embodiments.

[0093] As described above, it is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A photomask 2D measurement method, characterized in that: include: Dividing the photomask scanning pattern to obtain at least two divided parts; Superimposing the complete photomask scan pattern after division with the photomask design pattern to obtain the region of interest of each divided part after division; The difference between each divided part and the photomask design pattern is analyzed and compared to obtain the offset of each divided part.

2. The photomask 2D measurement method according to claim 1, characterized in that: Also includes: The average edge placement error value or average deviation value corresponding to each divided part is obtained through measurement software. The average edge placement error value reflects the proximity between the detected photomask and the photomask design pattern, and the average deviation value reflects whether the offset of each divided part relative to the photomask design pattern is large or small.

3. The photomask 2D measurement method according to claim 1, characterized in that: Also includes: The photomask scan pattern is divided according to the pattern features of the photomask design pattern.

4. The photomask 2D measurement method according to claim 1, characterized in that: Also includes: The offset of each divided portion is modified by introducing a mask process correction.

5. The photomask 2D measurement method according to claim 1, characterized in that: Also includes: According to the offset of each divided part, a correction scheme for the lines, apertures and spacing of the corresponding parts on the mask is obtained.

6. A photomask 2D measurement device, characterized in that: include: A division module, used for dividing the photomask scanning pattern to obtain at least two divided parts after division; An acquisition module is used to superimpose the complete photomask scan pattern after division with the photomask design pattern to obtain the region of interest of each divided part after division; The analysis module is used to analyze and compare the difference between each divided part and the photomask design pattern to obtain the offset of each divided part.

7. The photomask 2D measurement device according to claim 6, characterized in that: Also includes: The average edge placement error value or average deviation value corresponding to each divided part is obtained through measurement software. The average edge placement error value reflects the proximity between the detected photomask and the photomask design pattern, and the average deviation value reflects whether the offset of each divided part relative to the photomask design pattern is large or small.

8. The photomask 2D measurement device according to claim 6, characterized in that: Also includes: The photomask scan pattern is divided according to the specific pattern features of the photomask design pattern.

9. The photomask 2D measurement device according to claim 6, characterized in that: Also includes: The offset of each divided portion is modified by introducing a mask process correction.

10. The photomask 2D measurement device according to claim 6, characterized in that: Also includes: According to the offset of each divided part, a correction scheme for the lines, apertures and spacing of the corresponding parts on the mask is obtained.

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