Processing system and processing method for improving critical dimension uniformity of wafer

Abstract

The invention provides a processing system and method for improving the critical dimension uniformity of a wafer, and the system comprises an exposure module which is used for exposing a monitoring pattern to an effective pattern region of a mask; the detection module is used for acquiring size deviation data of the monitoring graph and detecting the size deviation data so as to ensure that the size deviation data is within a preset range; the photoetching module is used for transferring the pattern on the mask plate to the wafer; wherein the detection module is also used for measuring the critical dimension on the wafer and acquiring measurement data of different positions in each exposure area on the wafer; the photoetching module is used for adjusting the exposure dose required by the exposure area according to the measurement data so as to improve the critical dimension uniformity of the wafer. Through the processing system and the processing method for improving the critical dimension uniformity of the wafer provided by the invention, the critical dimension uniformity of the wafer can be improved.

Description

Technical Field

[0001] This invention relates to the field of semiconductors, and in particular to a processing system and method for improving the uniformity of critical dimensions of wafers. Background Technology

[0002] The uniformity of the critical dimension (CD) of a wafer is affected by a number of factors, including the manufacturing quality of the photomask, the stability and accuracy of the exposure parameters during the lithography process (spatial image process window), the optical proximity effect (optical interference phenomenon during the lithography process), the hardware performance of the lithography machine, the uniformity and sensitivity of the lithography material (such as photoresist), and the surface quality of the silicon substrate.

[0003] In the process of improving the critical dimension uniformity of wafers, how to achieve end-to-end monitoring and feedback from the mask to the wafer to the lithography machine, and maximize time and economic costs, remains a challenge. Summary of the Invention

[0004] The purpose of this invention is to provide a processing system and method for improving the uniformity of critical dimensions of wafers, which can improve the uniformity of critical dimensions of wafers.

[0005] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: This invention provides a processing system for improving the critical dimension uniformity of wafers, comprising: The exposure module is used to expose the monitoring image to the effective image area of ​​the mask; A detection module is used to acquire dimensional deviation data of the monitored graphic and to detect the dimensional deviation data to ensure that the dimensional deviation data is within a preset range; and A photolithography module is used to transfer the pattern on the photomask onto the wafer; The detection module is also used to measure key dimensions on the wafer and obtain measurement data at different locations in each exposure area on the wafer. The lithography module is used to adjust the required exposure dose in the exposure area based on measurement data, so as to improve the uniformity of the critical dimensions of the wafer.

[0006] In one embodiment of the present invention, the number of monitoring graphics is at least 60, and the plurality of monitoring graphics are evenly distributed in the effective graphic area of ​​the mask.

[0007] In one embodiment of the present invention, the monitoring graphic includes at least three sequentially adjacent graphic units, and the graphic unit includes at least one graphic feature selected from individual lines, individual gaps, dense lines, and dense gaps.

[0008] In one embodiment of the present invention, the graphic units in the plurality of monitoring graphics are arranged in the same and / or different ways, and the graphic units in the monitoring graphics are arranged in at least one of the following ways: horizontal direction, vertical direction, and stacking method.

[0009] In one embodiment of the present invention, the graphic unit includes multiple sets of lines placed along the horizontal and vertical directions.

[0010] In one embodiment of the present invention, when the spacing between adjacent lines of the graphic unit is the same in the monitoring graphic, the key dimensions of the graphic unit are different.

[0011] In one embodiment of the present invention, the graphic units are sorted in ascending order of the key dimensions, and the three graphic units are divided into a first graphic unit, a second graphic unit, and a third graphic unit. The key dimension of the first graphic unit is expressed as (1-N)×M, the key dimension of the second graphic unit is expressed as M, and the key dimension of the third graphic unit is expressed as (1+N)×M, where 0.69≤N<1.5.

[0012] In one embodiment of the present invention, the dimensional deviation data includes deviation data between the monitored pattern and the target pattern, deviation data of the monitored pattern in the horizontal and vertical directions, deviation data of individual lines and individual gaps of the same size on the mask, and deviation data of dense lines and individual lines of the same size on the mask. The preset range includes multiple deviation ranges, and different deviation data correspond to different deviation ranges. The deviation range is set according to the critical dimensions of the wafer.

[0013] In one embodiment of the present invention, the photolithography module is used to: The measurement data at different locations within each exposure area on the wafer are analyzed to calculate the required exposure dose correction value at different locations within each exposure area. A new exposure program is generated based on the exposure dose correction value, wherein the exposure program includes exposure dose adjustment parameters for different positions in each exposure area; The lithography module runs an exposure program to perform lithographic exposure on the next wafer to improve the uniformity of the wafer's critical dimensions.

[0014] The present invention also provides a method for improving the uniformity of critical dimensions of a wafer, comprising: Expose the monitoring image to the effective image area of ​​the mask; The size deviation data of the monitored image is acquired and the size deviation data is detected to ensure that the size deviation data is within a preset range; The pattern on the mask is transferred to the wafer; The key dimensions on the wafer are measured to obtain measurement data at different locations in each exposure area on the wafer; The required exposure dose for the exposure area is adjusted based on the measurement data to improve the critical dimension uniformity of the wafer.

[0015] As described above, the present invention provides a processing system and method for improving the uniformity of critical dimensions of wafers, with the unexpected effect being: 1. By automatically generating unified monitoring patterns, the same monitoring patterns and standards are used in the three stages of mask manufacturing, wafer critical dimension measurement data after photolithography, and photolithography machine compensation. This helps to unify data analysis and feedback standards and reduce mutual interference. Unified monitoring patterns and standards enable more efficient data analysis and feedback, improving the coordination between stages. Unified standards avoid mutual interference between different patterns and standards, thereby maximizing the improvement capabilities of each stage.

[0016] 2. By automatically generating monitoring patterns, specific areas (frames) on the mask can be utilized more effectively, increasing the number of monitoring patterns and improving chip yield. Optimizing the generation of monitoring patterns reduces unnecessary space occupation, allowing for the placement of more chips. By saving space, the actual wafer production efficiency and yield are improved. Placing more monitoring patterns in a limited space enhances the detection capability of mask manufacturing errors. By increasing the number of monitoring patterns, dimensional deviations (CD bias) from different areas are prevented from being copied onto the wafer, thereby reducing the risk of wafer critical dimension deviations (ADI CD bias).

[0017] 3. By forming the monitoring pattern within the actual working area of ​​the chip, the critical dimensions of the actual working area can be reflected more accurately, improving the monitoring effect. More precise monitoring of critical dimensions enhances the CDU correction capability of lithography machines (such as Nikon lithography machines), thereby improving overall lithography quality.

[0018] 4. The monitoring graphics can simultaneously monitor multiple key parameters, providing more comprehensive and accurate monitoring data. By monitoring the key dimensions and defects of different graphics, problems in the manufacturing process can be identified and resolved more effectively, improving overall manufacturing quality and stability.

[0019] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of a processing system for improving the uniformity of critical dimensions of a wafer in one embodiment of the present invention; Figure 2 This is a schematic diagram of a mask in one embodiment of the present invention; Figure 3 This is a schematic diagram of a monitoring graphic in one embodiment of the present invention; Figure 4 This is a schematic diagram of a line in a graphic unit according to an embodiment of the present invention; Figure 5 This is a schematic diagram of another type of line in a graphic unit according to one embodiment of the present invention; Figure 6 This is a schematic diagram of another type of line in a graphic unit according to an embodiment of the present invention; Figure 7 This is a schematic diagram of another type of line in a graphic unit according to an embodiment of the present invention; Figure 8 This is a flowchart of a method for improving the uniformity of critical dimensions of a wafer in one embodiment of the present invention.

[0022] In the picture: 100. Exposure module; 200. Inspection module; 300. Photolithography module; 400. Photomask; 410. Blank area; 420. Valid graphic area; 430. Monitored graphic; 431. Graphic unit; 4311. Individual line; 4312. Individual gap; 4313. Dense line; 4314. Dense gap; 432. First graphic unit; 433. Second graphic unit; 434. Third graphic unit. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Please see Figure 1This invention provides a processing system for improving the uniformity of critical dimensions in wafers. This system improves the final uniformity of critical dimensions in wafers from three aspects: mask manufacturing error monitoring, optical proximity effect, and lithography machine compensation. The processing system may include an exposure module 100, an inspection module 200, and a lithography module 300.

[0025] In one embodiment, the exposure module 100 can be used to expose the monitoring pattern 430 onto the effective pattern area 420 of the mask 400. During exposure, electron beam lithography or laser direct writing can be used.

[0026] In one embodiment, electron beam lithography involves directly writing a pattern onto a mask 400 using an electron beam. Due to the extremely high precision and focusing ability of the electron beam, precise exposure can be achieved in very small areas, making it suitable for generating very fine monitoring patterns 430. Electron beam lithography relies on an electron beam lithography system and its associated electron gun, lenses, scanning system, resist coating system, developing system, and etching equipment.

[0027] In one embodiment, laser direct writing is a technique that uses a laser beam to write patterns onto a mask 400. The laser beam can quickly scan and expose a designated area on the mask 400, thereby generating the desired monitoring pattern 430. Laser direct writing relies on a laser direct writing system and its associated laser, modulator, scanning system, resist coating system, developing system, and substrate processing equipment.

[0028] Please see Figure 2 In one embodiment, the mask 400 may have a blank area 410 and an active pattern area 420. The blank area 410 refers to an area without any patterns, typically a transparent area or an area not coated with resist. The blank area 410 corresponds to non-chip areas on the wafer (e.g., wafer edges or gaps between chips, including dicing lines, etc.). The active pattern area 420 refers to an area on the mask 400 containing circuit patterns designed to be transferred onto the wafer to form a chip. The active pattern area 420 corresponds to the chip area (die) on the wafer, i.e., each individual chip cell. The patterns on the active pattern area 420 generate a circuit structure on the wafer through exposure and development processes, ultimately forming a functional chip.

[0029] In one embodiment, there are spaces without circuit structures on the chip region (die) of the wafer. These spaces may correspond to a portion of the effective pattern region 420. In this case, the monitoring pattern 430 can be evenly distributed within a portion of the effective pattern region 420, thereby preventing the monitoring pattern 430 from interfering with the circuit structures on the chip unit. The number of monitoring patterns 430 is not limited. In this embodiment, the number of monitoring patterns 430 can be at least 60, for example, 60, 100, 200, etc. The monitoring patterns 430 need to be evenly distributed across the multiple effective pattern regions 420 of the mask 400.

[0030] Please see Figure 3 In one embodiment, the monitoring graphic 430 may include multiple graphic units 431, which need to be adjacent to each other in sequence. In this embodiment, the monitoring graphic 430 including at least three graphic units 431 is used as an example for explanation. The graphic units 431 in the monitoring graphic 430 may be arranged in at least one of the following ways: horizontal direction, vertical direction, and stacking.

[0031] For example, the graphic units 431 in the monitoring graphic 430 can be arranged horizontally within the effective graphic area 420. Alternatively, the graphic units 431 in the monitoring graphic 430 can be arranged vertically within the effective graphic area 420. Furthermore, the graphic units 431 in the monitoring graphic 430 can be stacked within the effective graphic area 420, and proportionally, the overall shape of the three graphic units 431 can be triangular.

[0032] In one embodiment, the graphic units 431 in the same monitoring graphic 430 need to be arranged in one of the following ways: horizontal, vertical, or stacked. The arrangement of the graphic units 431 in multiple monitoring graphics 430s may be the same or different. That is, the arrangement of the graphic units 431 in different monitoring graphics 430s may be the same or different. For example, some monitoring graphics 430s may have the graphic units 431 arranged horizontally, while other monitoring graphics 430s may have the graphic units 431 arranged vertically.

[0033] Please see Figure 4 , Figure 5 , Figure 6 and Figure 7In one embodiment, the patterning unit 431 may include at least one patterning feature such as individual lines 4311, individual gaps 4312, dense lines 4313, and dense gaps 4314. Individual lines 4311 and individual gaps 4312 can be used to evaluate the lithography process's ability to process a single pattern. Dense lines 4313 and dense gaps 4314 can be used to reveal the performance of the lithography process when processing high-density areas.

[0034] In one embodiment, the graphic unit 431 may include only one graphic feature: a single line 4311, or it may include only one graphic feature: dense lines 4313 and dense gaps 4314. In this embodiment, the graphic unit 431 may include four graphic features: a single line 4311, a single gap 4312, dense lines 4313, and dense gaps 4314.

[0035] In one embodiment, an ISO-Line 4311 refers to a line that exists independently without interference from other adjacent lines. An ISO-Line 4311 can be used to monitor the size and shape of a single line, assessing the resolution of the lithography process and its ability to process individual lines. Because there is no interference from other lines, the width and shape of the single line can be measured more accurately, helping to assess the optical performance and resist performance of the lithography system.

[0036] In one embodiment, an isolated gap 4312 (ISO-Space) refers to a gap that exists independently, without interference from other adjacent gaps. An isolated gap 4312 can be used to monitor the size and shape of a single gap, evaluating the accuracy of the photolithography process when handling that single gap. The isolated gap 4312 also helps in evaluating the solubility of the photoresist during development and the uniformity during etching.

[0037] In one embodiment, a dense line 4313 refers to a set of closely spaced lines. Dense lines 4313 can be used to monitor the distance and shape between a set of lines, evaluating the performance of the lithography process under high-density patterns. Due to the close proximity of the lines, dense lines 4313 are susceptible to optical diffraction and proximity effects, which can help detect the accuracy and resolution of the lithography process when processing high-density areas.

[0038] In one embodiment, dense-space 4314 refers to a set of closely spaced gaps. Dense-space 4314 can be used to monitor the distance and shape between a set of gaps, evaluating the ability of the lithography process to handle high-density gaps. Dense-space 4314 can help detect performance in high-density gap regions during development and etching, evaluating the uniformity of the etching process and the resolution of the lithography process.

[0039] Please see Figure 3 In one embodiment, each graphic unit 431 may include at least one individual line 4311 and at least one dense line 4313, and thus each graphic unit 431 may contain multiple sets of lines. The placement directions of the different lines may be different.

[0040] For example, some individual lines 4311 are placed along the horizontal direction, while other individual lines 4311 are placed along the vertical direction. In this case, the placement direction of some individual lines 4311 can be perpendicular to the placement direction of other individual lines 4311.

[0041] For example, if a single line 4311 is placed horizontally and a dense line 4313 is placed vertically, the placement direction of the single line 4311 can be perpendicular to the placement direction of the dense line 4313.

[0042] In this embodiment, the specific placement of lines in each graphic unit 431 is not limited, as long as the graphic unit 431 can simultaneously include multiple sets of lines placed in both the horizontal and vertical directions.

[0043] Please see Figure 3 In one embodiment, in a monitoring graph 430, the pitch of adjacent lines in different graph units 431 may be the same, and the key dimensions of the lines in different graph units 431 may be different.

[0044] For example, the monitoring graphic 430 may include three graphic units 431. Arranging the graphic units 431 in ascending order of their key dimensions, the three graphic units 431 can be distinguished as a first graphic unit 432, a second graphic unit 433, and a third graphic unit 434. The key dimension of the first graphic unit 432 can be expressed as (1-N)×M. The key dimension of the second graphic unit 433 can be expressed as M. The key dimension of the third graphic unit 434 can be expressed as (1+N)×M. 0.69 ≤ N < 1.5. That is, the ratio of the key dimension of the first graphic unit 432 to the key dimension of the second graphic unit 433 is less than or equal to 0.31. The ratio of the key dimension of the third graphic unit 434 to the key dimension of the second graphic unit 433 is greater than or equal to 1.69 and less than 2.5.

[0045] In one embodiment, after a monitoring pattern 430 is formed on the effective pattern area 420 of the mask 400, the monitoring pattern 430 needs to be measured to determine whether there is a deviation. In this embodiment, the detection module 200 can be used to obtain dimensional deviation data of the monitoring pattern 430 and detect the dimensional deviation data to ensure that the dimensional deviation data is within a preset range. If the dimensional deviation data of the current mask 400 is not within the preset range, it indicates that the mask 400 has a defect, and a new photolithography operation needs to be performed on a new mask 400.

[0046] In one embodiment, the detection module 200 can measure the dimensional deviation data of the monitoring graphic 430 using a critical dimension scanning electron microscope (CD-SEM) and statistical analysis software.

[0047] In one embodiment, the dimensional deviation data may include the deviation data between the monitored pattern 430 and the target pattern (Mask to Target, MTT), the deviation data of the monitored pattern 430 in the horizontal and vertical directions (XY bias), the deviation data between individual lines 4311 and individual gaps 4312 of the same size on the mask 400 (ISO line-space bias), and the deviation data between dense lines 4313 and individual lines 4311 of the same size on the mask 400 (Dense-ISO bias).

[0048] MTT (Mean Transmission Tolerance) is used to characterize the difference between the monitoring pattern 430 on the mask 400 and the designed target pattern, to evaluate the manufacturing accuracy of the mask 400. The target pattern refers to the pattern expected to be formed on the mask 400 after photolithography. The monitoring pattern 430 refers to the actual pattern formed on the mask 400 after photolithography. XY bias is used to characterize the deviation of the monitoring pattern 430 in the X and Y axis directions, measuring the manufacturing error of the pattern in these two directions. ISOline-space bias is used to evaluate the manufacturing deviation of individual lines 4311 of the same size design and target individual lines on the mask 400, as well as the manufacturing deviation of individual gaps 4312 of the same size design and target individual gaps on the mask 400. The target individual line refers to the individual line expected to be formed on the mask 400 after photolithography. The target individual gap refers to the individual gap expected to be formed on the mask 400 after photolithography. Dense-ISO bias can be used to evaluate the fabrication deviation of dense lines 4313 and target dense lines of the same size design on the mask 400, and the fabrication deviation of dense gaps 4314 and target dense gaps of the same size design on the mask 400. Here, target dense lines refer to the dense lines expected to be formed on the mask 400 after photolithography. Target dense gaps refer to the dense gaps expected to be formed on the mask 400 after photolithography.

[0049] Furthermore, since there is a magnification relationship between the monitoring pattern 430 on the mask 400 and the After Development Inspection Critical Dimension (ADI CD) on the wafer, the dimensional control of the monitoring pattern 430 directly affects the critical dimension on the wafer. Therefore, the dimensional deviation data of the monitoring pattern 430 needs to be within a preset range. Because there are multiple dimensional deviation data points, the preset range can also include multiple deviation ranges, with different deviation data points corresponding to different deviation ranges. The deviation range needs to be set according to the critical dimension of the wafer.

[0050] In one embodiment, the control requirements for the mask 400 need to be more stringent because any minute deviations in the monitored pattern 430 will be amplified on the wafer. In this embodiment, the deviation range of the monitored pattern 430 of the mask 400 needs to be within 3.5 times the critical dimension of the wafer. Measurement and control metrics for the critical dimension of the wafer may include the critical dimension range, standard deviation (3 sigma), and trend (X-Trend, Y-Trend, Radial).

[0051] Among them, Range can be used to represent the range of key dimensions, that is, the difference between the maximum and minimum values, and is used to measure the consistency of mask pattern dimensions. 3sigma is a statistical indicator used to measure the degree of data dispersion and the presence of outliers. It represents three times the standard deviation of the data and is used to evaluate the consistency and stability of mask dimensions. X-Trend is used to represent the dimensional variation trend of monitoring pattern 430 in the horizontal direction and to evaluate the uniformity of monitoring pattern 430 in the horizontal direction. Y-Trend is used to represent the dimensional variation trend of monitoring pattern 430 in the vertical direction and to evaluate the uniformity of monitoring pattern 430 in the vertical direction. Radial represents the dimensional variation trend of each monitoring pattern 430 from the center of the mask 400 to the center point, and is used to evaluate the radial uniformity of monitoring patterns 430 on the mask 400.

[0052] Furthermore, by precisely measuring and strictly controlling the monitoring pattern 430 on the mask 400, the monitoring and improvement of the wafer's critical dimensions can be maximized, which helps to ensure that the critical dimensions on the final wafer meet technical requirements, thereby improving the chip's manufacturing quality and yield.

[0053] In one embodiment, after the detection module 200 ensures that the dimensional deviation data is within a preset range, the pattern on the mask 400 can be transferred to the wafer via the photolithography module 300. During the photolithography process, the pattern on the mask 400 can be transferred to the wafer through processes such as coating, pre-baking, alignment, exposure, development, post-baking, etching, and resist stripping, using equipment such as a spin coater, bake oven, aligner, photolithography system, developer, etcher, and resist stripper in the photolithography module 300.

[0054] In one embodiment, after the pattern on the mask 400 is photolithographically etched onto the wafer by the photolithography module 300, the key dimensions on the wafer can be measured again by the detection module 200 to obtain measurement data at different locations within each exposure area (shot) on the wafer. The key dimensions on the wafer correspond to the monitoring pattern 430 on the mask 400. By measuring the key dimensions within each exposure area, measurement data of the key dimensions corresponding to the monitoring pattern 430 can be obtained.

[0055] In one embodiment, after the detection module 200 acquires measurement data of the critical dimension corresponding to the monitoring pattern 430, the detection module 200 can feed the measurement data back to the lithography module 300. The lithography module 300 can analyze the measurement data and generate a new program to correct the CDU (Critical Dimension Uniformity) within the shot of the lithography machine (such as a Nikon lithography machine) to improve and correct the uniformity of the critical dimension on the wafer.

[0056] Specifically, firstly, the photolithography module 300 can analyze measurement data at different locations within each exposure area on the wafer. By analyzing this data, it identifies deviations in critical dimensions at different locations within each exposure area. Based on these critical dimension deviations, it calculates the required exposure dose correction value for different locations within each exposure area.

[0057] Subsequently, the lithography module 300 can generate a new exposure program based on the exposure dose correction value. The exposure program includes exposure dose adjustment parameters for different locations within each exposure area. Specifically, the lithography module 300 can input the exposure dose correction value into the CDUM software, which calculates and generates a new exposure program containing specific exposure dose adjustment parameters to ensure that different locations within each exposure area receive the optimal exposure dose, thereby improving the consistency of critical dimensions.

[0058] Finally, the lithography module 300 runs the exposure program to perform lithography exposure on the next wafer, thereby improving the uniformity of critical dimensions. Specifically, the lithography module 300 can load and run a new exposure program to perform lithography exposure on the next batch of wafers, adjusting the exposure dose at different locations in each exposure area in real time. Measurement data after each exposure is fed back to the CDUM software to continuously optimize and adjust the exposure program, achieving continuous improvement and optimization of critical dimension uniformity.

[0059] As can be seen, the unexpected effect of the above solution is: 1. By automatically generating unified monitoring patterns, the same monitoring patterns and standards are used in the three stages of mask manufacturing, wafer critical dimension measurement data after photolithography, and photolithography machine compensation. This helps to unify data analysis and feedback standards and reduce mutual interference. Unified monitoring patterns and standards enable more efficient data analysis and feedback, improving the coordination between stages. Unified standards avoid mutual interference between different patterns and standards, thereby maximizing the improvement capabilities of each stage.

[0060] 2. By automatically generating monitoring patterns, specific areas (frames) on the mask can be utilized more effectively, increasing the number of monitoring patterns and improving chip yield. Optimizing the generation of monitoring patterns reduces unnecessary space occupation, allowing for the placement of more chips. By saving space, the actual wafer production efficiency and yield are improved. Placing more monitoring patterns in a limited space enhances the detection capability of mask manufacturing errors. By increasing the number of monitoring patterns, dimensional deviations (CD bias) from different areas are prevented from being copied onto the wafer, thereby reducing the risk of wafer critical dimension deviations (ADI CD bias).

[0061] 3. By forming the monitoring pattern within the actual working area of ​​the chip, the critical dimensions of the actual working area can be reflected more accurately, improving the monitoring effect. More precise monitoring of critical dimensions enhances the CDU correction capability of lithography machines (such as Nikon lithography machines), thereby improving overall lithography quality.

[0062] 4. The monitoring graphics can simultaneously monitor multiple key parameters, providing more comprehensive and accurate monitoring data. By monitoring the key dimensions and defects of different graphics, problems in the manufacturing process can be identified and resolved more effectively, improving overall manufacturing quality and stability.

[0063] Please see Figure 8 The present invention also provides a method for improving the uniformity of critical dimensions of wafers. This method can be applied to the above-mentioned processing system and may include: Step S10: Expose the monitoring image to the effective image area of ​​the mask; Step S20: Obtain the dimensional deviation data of the monitoring graphic and detect the dimensional deviation data to ensure that the dimensional deviation data is within the preset range; Step S30: Transfer the pattern on the mask to the wafer; Step S40: Measure the key dimensions on the wafer and obtain measurement data at different locations in each exposure area on the wafer; Step S50: Adjust the required exposure dose in the exposure area based on the measurement data to improve the uniformity of the critical dimensions of the wafer.

[0064] The embodiments of the present invention disclosed above are merely illustrative of the invention. The embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A processing system for improving the uniformity of critical dimensions of a wafer, characterized in that, include: The exposure module is used to expose the monitoring image to the effective image area of ​​the mask; The detection module is used to acquire the size deviation data of the monitored graphic and to detect the size deviation data to ensure that the size deviation data is within a preset range. as well as A photolithography module is used to transfer the pattern on the photomask onto the wafer; The detection module is also used to measure key dimensions on the wafer and obtain measurement data at different locations in each exposure area on the wafer. The lithography module is used to adjust the required exposure dose in the exposure area based on measurement data, so as to improve the uniformity of the critical dimensions of the wafer.

2. The processing system for improving the critical dimension uniformity of wafers according to claim 1, characterized in that, The number of monitoring graphics is at least 60, and the multiple monitoring graphics are evenly distributed in the effective graphic area of ​​the mask.

3. The processing system for improving the critical dimension uniformity of wafers according to claim 1, characterized in that, The monitoring graphic includes at least three sequentially adjacent graphic units, and each graphic unit includes at least one graphic feature selected from individual lines, individual gaps, dense lines, and dense gaps.

4. The processing system for improving the critical dimension uniformity of wafers according to claim 3, characterized in that, The graphic units in the multiple monitoring graphics are arranged in the same and / or different ways, and the graphic units in the monitoring graphics are arranged in at least one of the following ways: horizontal direction, vertical direction, and stacking method.

5. The processing system for improving the critical dimension uniformity of wafers according to claim 3, characterized in that, The graphic unit includes multiple sets of lines placed along the horizontal and vertical directions.

6. The processing system for improving the critical dimension uniformity of wafers according to claim 3, characterized in that, In the monitoring graphic, when the spacing between adjacent lines of the graphic unit is the same, the key dimensions of the graphic unit are different.

7. The processing system for improving the critical dimension uniformity of wafers according to claim 6, characterized in that, The graphic units are sorted in ascending order of their key dimensions. The three graphic units are divided into a first graphic unit, a second graphic unit, and a third graphic unit. The key dimension of the first graphic unit is expressed as (1-N)×M, the key dimension of the second graphic unit is expressed as M, and the key dimension of the third graphic unit is expressed as (1+N)×M, where 0.69≤N<1.

5.

8. The processing system for improving the critical dimension uniformity of wafers according to claim 1, characterized in that, The dimensional deviation data includes deviation data between the monitored pattern and the target pattern, deviation data of the monitored pattern in the horizontal and vertical directions, deviation data of individual lines and individual gaps of the same size on the mask, and deviation data of dense lines and individual lines of the same size on the mask. The preset range includes multiple deviation ranges, and different deviation data correspond to different deviation ranges. The deviation range is set according to the critical dimensions of the wafer.

9. The processing system for improving the critical dimension uniformity of wafers according to claim 1, characterized in that, The photolithography module is used for: The measurement data at different locations within each exposure area on the wafer are analyzed to calculate the required exposure dose correction value at different locations within each exposure area. A new exposure program is generated based on the exposure dose correction value, wherein the exposure program includes exposure dose adjustment parameters for different positions in each exposure area; The lithography module runs an exposure program to perform lithographic exposure on the next wafer to improve the uniformity of the wafer's critical dimensions.

10. A method for improving the uniformity of critical dimensions of a wafer, characterized in that, include: Expose the monitoring image to the effective image area of ​​the mask; The size deviation data of the monitored image is acquired and the size deviation data is detected to ensure that the size deviation data is within a preset range; The pattern on the mask is transferred to the wafer; The key dimensions on the wafer are measured to obtain measurement data at different locations in each exposure area on the wafer; The required exposure dose for the exposure area is adjusted based on the measurement data to improve the critical dimension uniformity of the wafer.

Images