A processing system and method for improving the uniformity of critical dimensions of wafers

Abstract

This invention provides a processing system and method for improving the critical dimension uniformity of wafers. The processing system includes an exposure module for exposing a monitoring pattern to an effective pattern area on a photomask; a detection module for acquiring dimensional deviation data of the monitoring pattern and detecting the dimensional deviation data to ensure that the dimensional deviation data is within a preset range; and a photolithography module for transferring the pattern on the photomask to the wafer. The detection module is further used to measure critical dimensions on the wafer, acquiring measurement data at different locations within each exposure area on the wafer. The photolithography module is used to adjust the required exposure dose for the exposure area based on the measurement data to improve the critical dimension uniformity of the wafer. The processing system and method for improving the critical dimension uniformity of wafers provided by this invention can improve the critical dimension uniformity of wafers.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of semiconductor, in particular to a processing system and processing method for improving critical dimension uniformity of wafer. BACKGROUND

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

[0003] In the process of improving the critical dimension uniformity of wafer, how to realize the full-process monitoring and improvement feedback from the mask plate to the wafer and then to the photolithography machine, and maximize the time and economic cost, is still a challenge. SUMMARY

[0004] The present application aims to provide a processing system and processing method for improving the critical dimension uniformity of wafer, which can improve the critical dimension uniformity of wafer.

[0005] To solve the above technical problems, the present application is realized by the following technical solutions:

[0006] The present application provides a processing system for improving the critical dimension uniformity of wafer, comprising:

[0007] An exposure module is used to expose a monitoring pattern to the effective pattern area of the mask plate;

[0008] A detection module is used to obtain size deviation data of the monitoring pattern, and detect the size deviation data to ensure that the size deviation data is within a preset range; and

[0009] A photolithography module is used to transfer the pattern on the mask plate to the wafer;

[0010] The detection module is further used to measure the critical dimension on the wafer, and obtain measurement data of different positions in each exposure area on the wafer;

[0011] The photolithography module is used to adjust the exposure dose required by the exposure area according to the measurement data, so as to improve the critical dimension uniformity of the wafer.

[0012] In an embodiment of the present application, the number of monitoring patterns is at least 60, and the plurality of monitoring patterns are uniformly distributed in the effective pattern area of the mask plate.

[0013] In an embodiment of the present application, the monitoring pattern comprises at least three sequentially adjacent graphic units, and the graphic units comprise at least one graphic feature of a single line, a single gap, dense lines, and dense gaps.

[0014] In an embodiment of the present application, the arrangement of the graphic units in the plurality of monitoring patterns is the same and / or different, and the graphic units in the monitoring patterns are arranged in at least one of a horizontal direction, a vertical direction, and a stacking manner.

[0015] In an embodiment of the present application, the graphic units comprise a plurality of groups of lines arranged in a horizontal direction and a vertical direction.

[0016] In an embodiment of the present application, in the monitoring pattern, when the intervals of the adjacent lines of the graphic units are the same, the critical dimensions of the graphic units are different.

[0017] In an embodiment of the present application, the graphic units are sorted in an order from small to large according to the critical dimensions, and the three graphic units are divided into a first graphic unit, a second graphic unit, and a third graphic unit, the critical dimension of the first graphic unit is represented as (1-N) x M, the critical dimension of the second graphic unit is represented as M, and the critical dimension of the third graphic unit is represented as (1+N) x M, wherein 0.69≤N<1.5.

[0018] In an embodiment of the present application, the size deviation data comprises deviation data of the monitoring pattern and the target pattern, deviation data of the monitoring pattern in the horizontal direction and the vertical direction, deviation data of the single lines and the single gaps of the same size on the mask, and deviation data of the dense lines and the single lines of the same size on the mask, the preset range comprises a plurality of deviation ranges, different deviation data corresponds to different deviation ranges, and the deviation ranges are set according to the critical dimensions of the wafer.

[0019] In an embodiment of the present application, the lithography module is used to:

[0020] analyze the measurement data of different positions in each exposure area on the wafer, and calculate the exposure dose correction values required by different positions in each exposure area;

[0021] generate a new exposure recipe based on the exposure dose correction values, wherein the exposure recipe comprises exposure dose adjustment parameters for different positions in each exposure area;

[0022] the lithography module runs the exposure recipe to perform lithography exposure on the next wafer to improve the critical dimension uniformity of the wafer.

[0023] The application further provides a processing method for improving the critical dimension uniformity of a wafer, comprising:

[0024] exposing a monitoring pattern into an effective pattern area of a mask plate;

[0025] acquiring size deviation data of the monitoring pattern, and detecting the size deviation data to ensure that the size deviation data is within a preset range;

[0026] transferring the pattern on the mask plate to a wafer;

[0027] measuring the critical dimension of the wafer to acquire measurement data of different positions in each exposure area on the wafer;

[0028] adjusting the exposure dose required by the exposure area according to the measurement data to improve the critical dimension uniformity of the wafer.

[0029] As described above, the application provides a processing system and a processing method for improving the critical dimension uniformity of a wafer, and the unexpected effects are:

[0030] 1. By automatically generating a unified monitoring pattern, the same monitoring pattern and standard are used in the three links of mask plate manufacturing, measurement data of the critical dimension of the wafer after the photolithography process, and photolithography machine compensation, which helps to unify data analysis and feedback standards and reduces mutual interference. Through the unified monitoring pattern and standard, data can be more efficiently analyzed and fed back, and the coordination of each link can be improved. The unified standard avoids the mutual interference of different patterns and standards, thereby maximizing the improvement capability of each link.

[0031] 2. By automatically generating a monitoring pattern, the specific area (Frame) on the mask plate can be more effectively utilized, the number of monitoring patterns can be increased, and the chip yield can be improved. Optimizing the generation of monitoring patterns reduces unnecessary space occupation, so that more chips can be arranged. Through space saving, the actual production efficiency and yield of the wafer are improved. More monitoring patterns are arranged in a limited space to improve the detection capability of mask plate manufacturing errors. By increasing the monitoring patterns, the size deviation (CD bias) of different areas is avoided to be copied to the wafer, thereby reducing the risk of critical dimension deviation (ADI CD bias) of the wafer.

[0032] 3. By forming the monitoring pattern in the actual working area of the chip, the critical dimension condition of the actual working area can be more accurately reflected, and the monitoring effect is improved. Through more accurate critical dimension monitoring, the CDU correction capability of the photolithography machine (such as Nikon photolithography machine) is improved, and the overall photolithography quality is improved.

[0033] 4、The monitoring pattern can realize the monitoring of multiple key parameters synchronously, and provide more comprehensive and accurate monitoring data. Through the monitoring of key dimensions and defects of different patterns, the problems in the manufacturing process can be identified and solved more effectively, and the overall manufacturing quality and stability can be improved.

[0034] Of course, implementing any product of the present application does not necessarily require achieving all the advantages described above at the same time. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed for the description of the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0036] Figure 1 A schematic diagram of a processing system for improving the key dimension uniformity of a wafer in an embodiment of the present application;

[0037] Figure 2 A schematic diagram of a mask plate in an embodiment of the present application;

[0038] Figure 3 A schematic diagram of a monitoring pattern in an embodiment of the present application;

[0039] Figure 4 A schematic diagram of a line of a pattern unit in an embodiment of the present application;

[0040] Figure 5 A schematic diagram of another line of a pattern unit in an embodiment of the present application;

[0041] Figure 6 A schematic diagram of still another line of a pattern unit in an embodiment of the present application;

[0042] Figure 7 A schematic diagram of yet another line of a pattern unit in an embodiment of the present application;

[0043] Figure 8 A flowchart of a processing method for improving the key dimension uniformity of a wafer in an embodiment of the present application.

[0044] In the drawings:

[0045] 100, exposure module; 200, detection module; 300, photolithography module; 400, mask plate;

[0046] 410, blank area; 420, active pattern area; 430, monitoring pattern; 431, pattern unit; 4311, single line; 4312, single gap; 4313, dense line; 4314, dense gap;

[0047] 432, first pattern unit; 433, second pattern unit; 434, third pattern unit. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0049] Referring to Figure 1 The present application provides a processing system for improving the uniformity of the critical dimension of a wafer. The processing system can improve the uniformity of the critical dimension of the wafer from three aspects: mask manufacturing error monitoring, optical proximity effect, and lithography machine compensation. The processing system can include an exposure module 100, a detection module 200, and a lithography module 300.

[0050] In one embodiment, the exposure module 100 can be used to expose the monitoring pattern 430 to the active pattern area 420 of the mask 400. During the exposure, E-beam Lithography or Laser Direct Writing can be used.

[0051] In one embodiment, E-beam Lithography is a technique that uses an electron beam to directly write patterns on the mask 400. Because the electron beam has extremely high precision and focusing ability, it can accurately expose a very small area, and thus is suitable for generating very fine monitoring patterns 430. E-beam Lithography requires an E-beam Lithography system and its supporting electron gun, lens, scanning system, resist coating system, developing system, and etching equipment.

[0052] In one embodiment, Laser Direct Writing is a technique that uses a laser beam to write patterns on the mask 400. The laser beam can quickly scan and expose a specified area on the mask 400, thereby generating the required monitoring pattern 430. Laser Direct Writing requires a Laser Direct Writing system and its supporting laser, modulator, scanning system, resist coating system, developing system, and substrate processing equipment.

[0053] Referring to Figure 2In one embodiment, the mask 400 can be provided with a blank area 410 and an effective pattern area 420. The blank area 410 refers to an area without any pattern, which is usually transparent or not coated with resist. The blank area 410 corresponds to the non-die area (e.g. wafer edge or gap between dies, including scribe lane, etc.) on the wafer. The effective pattern area 420 refers to an area on the mask 400 containing circuit patterns, which are designed to be transferred to the wafer to form dies. The effective pattern area 420 corresponds to the die area (i.e. each individual die unit) on the wafer. The patterns on the effective pattern area 420 generate circuit structures on the wafer through the exposure and development processes, and finally form functional dies.

[0054] In one embodiment, there is a space without circuit structures on the die area on the wafer, which can correspond to a partial area of the effective pattern area 420. In this case, the monitoring patterns 430 can be evenly distributed in the partial area of the effective pattern area 420, thereby preventing the monitoring patterns 430 from interfering with the circuit structures on the die units. The number of monitoring patterns 430 can be unlimited. In this embodiment, the number of monitoring patterns 430 can be at least 60, such as 60, 100, 200, etc. The monitoring patterns 430 need to be evenly arranged in multiple effective pattern areas 420 of the mask 400.

[0055] Please refer to Figure 3 In one embodiment, the monitoring patterns 430 can include multiple pattern units 431, which need to be adjacent in sequence. In this embodiment, at least three pattern units 431 are included in the monitoring patterns 430 as an example for illustration. The pattern units 431 in the monitoring patterns 430 can be arranged in at least one of the horizontal direction, the vertical direction and the stacking manner.

[0056] For example, the pattern units 431 in the monitoring patterns 430 can be arranged in the effective pattern area 420 along the horizontal direction. For another example, the pattern units 431 in the monitoring patterns 430 can be arranged in the effective pattern area 420 along the vertical direction. For yet another example, the pattern units 431 in the monitoring patterns 430 can be arranged in the effective pattern area 420 in a stacking manner, i.e. the overall shape of the three pattern units 431 can be in a triangular shape.

[0057] In one embodiment, the pattern elements 431 in the same monitor pattern 430 are arranged in one of the lateral direction, the vertical direction, and the stacked manner. The arrangement of the pattern elements 431 in the plurality of monitor patterns 430 can be the same and / or different. That is, the arrangement of the pattern elements 431 in different monitor patterns 430 can be the same or different. For example, the arrangement of the pattern elements 431 in some monitor patterns 430 can be in the lateral direction, and the arrangement of the pattern elements 431 in other monitor patterns 430 can be in the vertical direction.

[0058] Please refer to Figure 4 , Figure 5 , Figure 6 and Figure 7 In one embodiment, the pattern elements 431 can include at least one of the following pattern features: isolated line 4311, isolated space 4312, dense line 4313, and dense space 4314. The isolated line 4311 and the isolated space 4312 can be used to evaluate the processing capability of the lithography process on a single pattern. The dense line 4313 and the dense space 4314 can be used to reveal the performance of the lithography process in processing high-density areas.

[0059] In one embodiment, the pattern elements 431 can include only one of the following pattern features: isolated line 4311, dense line 4313, and dense space 4314. In this embodiment, the pattern elements 431 can include all of the following pattern features: isolated line 4311, isolated space 4312, dense line 4313, and dense space 4314.

[0060] In one embodiment, the isolated line 4311 (ISO-Line) refers to a line that exists alone without the interference of adjacent lines. The isolated line 4311 can be used to monitor the size and shape of a single line, and to evaluate the resolution and processing capability of the lithography process on a single line. Since there is no interference from other lines, the width and shape of a single line can be more accurately measured, which helps to detect the optical performance of the lithography system and the performance of the resist.

[0061] In one embodiment, the isolated space 4312 (ISO-Space) refers to a space that exists alone without the interference of adjacent spaces. The isolated space 4312 can be used to monitor the size and shape of a single space, and to evaluate the accuracy of the lithography process in processing a single space. The isolated space 4312 helps to evaluate the dissolution performance in the resist development process and the uniformity in the etching process.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] Please see Figure 3 In one embodiment, in a monitoring graphic 430, the pitch of adjacent lines in different graphic units 431 may be the same, and the key dimensions of the lines in different graphic units 431 may be different.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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).

[0073] 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.

[0074] 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.

[0075] 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).

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] As can be seen, the unexpected effect of the above solution is:

[0085] 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.

[0086] 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).

[0087] 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.

[0088] 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.

[0089] Please see Figure 8 The present invention also provides a processing method for improving the uniformity of critical dimensions of wafers. This processing method can be applied to the above-mentioned processing system and may include:

[0090] Step S10: Expose the monitoring image to the effective image area of ​​the mask;

[0091] 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;

[0092] Step S30: Transfer the pattern on the mask to the wafer;

[0093] Step S40: Measure the key dimensions on the wafer and obtain measurement data at different locations in each exposure area on the wafer;

[0094] 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.

[0095] 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 critical dimension uniformity of a wafer, the processing system comprising: The processing system comprises: an exposure module configured to expose a monitoring pattern to an effective pattern area of a mask plate; a detection module configured to obtain size deviation data of the monitoring pattern exposed to the effective pattern area, and detect the size deviation data to ensure that the size deviation data is within a preset range; a photolithography module configured to transfer a pattern on the mask plate to a wafer; wherein the detection module is further configured to measure a critical dimension of the wafer, and obtain measurement data of different positions in each exposure area of the wafer; the photolithography module is configured to adjust an exposure dose required by the exposure area according to the measurement data, so as to improve the critical dimension uniformity of the wafer; the monitoring pattern comprises at least three sequentially adjacent pattern units, the pattern units comprise at least one of a single line, a single gap, dense lines and dense gaps; the pattern units are sorted in ascending order of the critical dimension, and the three pattern units are divided into a first pattern unit, a second pattern unit and a third pattern unit, the critical dimension of the first pattern unit is represented as (1-N)×M, the critical dimension of the second pattern unit is represented as M, and the critical dimension of the third pattern unit is represented as (1+N)×M, wherein 0.69≤N<1.

5. The number of the monitoring patterns is at least 60, and the monitoring patterns are uniformly distributed in the effective pattern area of the mask plate. The arrangement modes of the pattern units in the monitoring patterns are the same or different, and the pattern units in the monitoring patterns are arranged in at least one of a horizontal direction, a vertical direction and a stacking mode.

2. The process system for improving critical dimension uniformity of a wafer of claim 1, wherein, The pattern units comprise a plurality of groups of lines arranged in the horizontal direction and the vertical direction.

3. The process system for improving critical dimension uniformity of a wafer of claim 1, wherein, In the monitoring pattern, the critical dimensions of the pattern units are different when the distances between adjacent lines of the pattern units are the same.

4. The process system for improving critical dimension uniformity of a wafer of claim 1, wherein, The size deviation data comprises deviation data of the monitoring pattern and a target pattern, deviation data of the monitoring pattern in the horizontal direction and the vertical direction, deviation data of single lines and single gaps of the same size on the mask plate, and deviation data of dense lines and single lines of the same size on the mask plate, the preset range comprises a plurality of deviation ranges, different deviation data corresponds to different deviation ranges, and the deviation ranges are set according to the critical dimension of the wafer.

5. The process system for improving critical dimension uniformity of a wafer of claim 1, wherein, The photolithography module is configured to:

6. The process system for improving critical dimension uniformity of a wafer of claim 1, wherein, analyze the measurement data of different positions in each exposure area of the wafer, and calculate exposure dose correction values required by different positions in each exposure area; 7. The process system for improving critical dimension uniformity of a wafer of claim 1, wherein, generate a new exposure recipe based on the exposure dose correction values, wherein the exposure recipe comprises exposure dose adjustment parameters for different positions in each exposure area; the photolithography module runs the exposure recipe to perform photolithography exposure on a next wafer, so as to improve the critical dimension uniformity of the wafer. The processing method is applied to the processing system for improving the critical dimension uniformity of the wafer, and the processing method comprises: exposing a monitoring pattern to an effective pattern area of a mask plate; 8. A processing method for improving critical dimension uniformity of a wafer, the method comprising: ​ ​ acquiring size deviation data of the monitoring pattern, and detecting the size deviation data to ensure that the size deviation data is within a preset range; transferring the pattern on the mask to a wafer; measuring a critical dimension on the wafer to acquire measurement data of different positions in each exposure area on the wafer; adjusting an exposure dose required by the exposure area according to the measurement data to improve critical dimension uniformity of the wafer.

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