Optical critical dimension measuring machine

Abstract

The utility model relates to an optical critical dimension measuring machine table, which comprises a machine table body, a mask plate and an optical monitoring module, and is characterized in that the mask plate is located on a carrying table of the machine table body, and the mask plate comprises a plurality of target patterns which are periodically arranged; wherein each target graph comprises a plurality of sub-graphs and at least one critical dimension position, and the critical dimension position is a position between two adjacent sub-graphs; the optical monitoring module is used for measuring key size information of each target graph and comparing the key size information with corresponding preset size information to monitor whether the key size information is abnormal or not; the critical dimension information comprises a first distance between two sub-graphs corresponding to the critical dimension position, the thickness of the sub-graphs and a second distance between two adjacent target graphs. According to the invention, real-time monitoring of the three-dimensional critical dimension of the target graph can be realized, the defect position can be found in time, the measurement efficiency is improved, and the semiconductor yield is improved.

Description

Technical Field

[0001] This application relates to the field of semiconductor manufacturing, and in particular to an optical critical dimension measuring machine. Background Technology

[0002] Semiconductor chips continue to evolve towards increasing density and shrinking device size, with gate line width being one of the most critical parameters. Any deviation between the photoresist line width after photolithography or the gate line width after etching and the design dimensions directly affects the performance, yield, and reliability of the final device. Therefore, advanced process control requires online measurement of line width, commonly known as critical dimension (CD) measurement.

[0003] Currently, optical critical-dimensional (OCD) measurement based on diffraction optics has become a major tool in advanced semiconductor manufacturing processes. However, critical dimensions inside complex patterns and nanoscale patterns are difficult to measure during semiconductor manufacturing, which reduces semiconductor yield. Utility Model Content

[0004] Therefore, it is necessary to provide an optical critical dimension measurement machine to address the problems mentioned above, so as to monitor the critical dimensions of semiconductor patterns in real time according to the actual situation, avoid semiconductor defects, and improve semiconductor yield.

[0005] According to various embodiments of this application, a first aspect of this application provides an optical critical dimension measurement instrument, including an instrument body, a mask, and an optical monitoring module. The mask is located on a platform of the instrument body and includes multiple target patterns arranged periodically. Each target pattern includes multiple sub-patterns and at least one critical dimension position, where the critical dimension position is the position between two adjacent sub-patterns. The optical monitoring module is used to measure the critical dimension information of each target pattern and compare the critical dimension information with corresponding preset dimension information to monitor whether the critical dimension information is abnormal. The critical dimension information includes a first distance between two sub-patterns corresponding to the critical dimension position, the thickness of the sub-pattern, and a second distance between two adjacent target patterns.

[0006] The optical critical dimension measurement machine in the above embodiments measures the optical critical dimensions of the target patterns by placing a mask comprising multiple periodically arranged target patterns on a platform of the machine body. Each target pattern includes multiple sub-patterns and at least one critical dimension position, which is the position between two adjacent sub-patterns. The critical dimension information of each target pattern is measured by an optical monitoring module, and the critical dimension information is compared with the corresponding preset dimension information to monitor whether the critical dimension information is abnormal. This enables real-time monitoring of the critical dimension position of the target pattern during semiconductor manufacturing. If the monitored critical dimension information of the target pattern is inconsistent with the preset dimension information, defects in the semiconductor generated in each process can be detected in a timely manner, shortening the measurement time and improving the measurement efficiency. The critical dimension information includes the first spacing between the two sub-patterns corresponding to the critical dimension position, the thickness of the sub-pattern, and the second spacing between two adjacent target patterns, preventing bridging between two sub-patterns and between two adjacent target patterns, thereby improving the semiconductor yield.

[0007] In some embodiments, the target graphic includes a plurality of sub-graphics arranged in an array, the sub-graphics being strip-shaped graphics; wherein, the key dimension position is the position between two adjacent sub-graphics in the row direction of the array, and the row direction is the extension direction of the sub-graphics.

[0008] In some embodiments, the target graphic includes a plurality of first sub-graphics and a second sub-graphic; wherein the plurality of first sub-graphics are arranged along a first direction and extend along a second direction, the second sub-graphic extends along the first direction, the second sub-graphic is located on one side of the first sub-graphic, and the first sub-graphic and the second sub-graphic are strip-shaped graphics; wherein the key dimension position is located between any of the first sub-graphics and the second sub-graphic.

[0009] In some embodiments, the target graphic includes a plurality of third sub-graphics and a plurality of fourth sub-graphics; wherein the width dimension of the fourth sub-graphic in the first direction is greater than the width dimension of the third sub-graphic in the first direction, the length dimension of the third sub-graphic and the fourth sub-graphic in the second direction is the same, the plurality of third sub-graphics and the plurality of fourth sub-graphics are arranged in an array along the first direction, and each fourth sub-graphic is located on the outside of the array; wherein the key dimension position is located between two adjacent third sub-graphics.

[0010] In some embodiments, the target graphic includes a fifth sub-graphic and a sixth sub-graphic; wherein the fifth sub-graphic is a strip-shaped graphic and extends along a first direction, the sixth sub-graphic includes a plurality of first strip-shaped sub-graphics, and the plurality of first strip-shaped sub-graphics are connected to form an opening; a first end of the fifth sub-graphic is located at the opening, and a second end of the fifth sub-graphic is exposed outside the opening; wherein a key dimension position is located at the fifth sub-graphic, and another key dimension position is located between the fifth sub-graphic and the sixth sub-graphic.

[0011] In some embodiments, the target graphic includes a seventh sub-graphic and a plurality of eighth sub-graphics; wherein the seventh sub-graphic includes a plurality of second strip-shaped sub-graphics, and the plurality of second strip-shaped sub-graphics are connected to form an opening; the eighth sub-graphic is a strip-shaped graphic, and the plurality of eighth sub-graphics are arranged in an array at the opening; wherein, one key dimension position is the position between two adjacent eighth sub-graphics in the row direction of the array, and the row direction is the extension direction of the target graphic; another key dimension position is the position between two adjacent eighth sub-graphics in the column direction of the array, and yet another key dimension position is the position between adjacent seventh and eighth sub-graphics in the column direction of the array.

[0012] In some embodiments, the first spacing between the two sub-patterns corresponding to the critical dimension location ranges from 40 to 90 nanometers.

[0013] In some embodiments, the optical critical dimension measurement instrument further includes a spectral acquisition module and a processing module. The spectral acquisition module is used to acquire spectral information at each critical dimension position. The processing module is connected to the spectral acquisition module and is used to store a preset critical dimension measurement model and the simulated spectral information corresponding to the preset critical dimension measurement model, and to verify whether the preset critical dimension measurement model is consistent with the target graphic based on the spectral information and the simulated spectral information. The preset dimension information is determined by the preset critical dimension measurement model.

[0014] In some embodiments, the spectral acquisition module includes an etching site spectral acquisition unit and a grinding site spectral acquisition unit. The etching site spectral acquisition unit is used to acquire the first emission spectrum of the key dimension location after the mask is etched; the grinding site spectral acquisition unit is used to acquire the second emission spectrum of the key dimension location after the mask is ground. The waveforms of the first emission spectrum and the second emission spectrum are different; wherein, the spectral information includes at least one of the first emission spectrum and the second emission spectrum.

[0015] In some embodiments, the aforementioned optical critical dimension measuring machine further includes a storage module connected to the processing module, used to store the critical dimension positions and preset dimension information corresponding to multiple target graphics.

[0016] The unexpected technical effects of this application are as follows: By placing a mask containing multiple periodically arranged target patterns on the platform of the machine body, optical key dimension measurement of the target patterns is performed. The key dimension information of each target pattern is measured by an optical monitoring module, and the key dimension information is compared with the corresponding preset dimension information to monitor whether the key dimension information is abnormal. Real-time monitoring of the three-dimensional key dimensions of the target pattern can be achieved, the defect location can be detected in time, and the problem can be avoided by only discovering the problem when measuring electrical properties, thus avoiding the waste of resources. Furthermore, optical measurement is more accurate and does not damage the semiconductor, thereby improving measurement efficiency and semiconductor yield. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a top view of a long straight line graphic provided in one embodiment of this application;

[0019] Figure 2 This is a schematic structural block diagram of an optical critical dimension measuring machine provided in one embodiment of this application;

[0020] Figures 3-7 This is a top view of the target graphic provided in another embodiment of this application;

[0021] Figure 8 This is a schematic diagram of the structure of an optical critical dimension measuring machine provided in another embodiment of this application;

[0022] Figure 9 This is a schematic structural block diagram of an optical critical dimension measuring machine provided in another embodiment of this application;

[0023] Figure 10 This is a schematic structural block diagram of an optical critical dimension measuring machine provided in another embodiment of this application;

[0024] Figure 11 This is a top view schematic diagram of the mask and key dimension information provided in one embodiment of this application.

[0025] Explanation of reference numerals in the attached figures:

[0026] 10. Long straight line graphic; 100. Optical critical dimension measurement machine; 110. Machine body; 120. Mask; 121. Target graphic; 1210. Sub-graphic; 1211. First sub-graphic; 1212. Second sub-graphic; 1213. Third sub-graphic; 1214. Fourth sub-graphic; 1215. Fifth sub-graphic; 1216. Sixth sub-graphic; 1217. Seventh sub-graphic; 1218. Eighth sub-graphic; 130. Optical monitoring module; 140. Spectrum acquisition module; 141. Etching station spectrum acquisition device; 142. Grinding station spectrum acquisition device; 150. Processing module; 160. Storage module; A. Critical dimension position; B. Opening; h1 / h2. Width dimension; d1. Length dimension; d2. First spacing; d3. Second spacing. Detailed Implementation

[0027] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0029] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0030] When using the terms “including,” “having,” and “comprising” as described herein, another component may be added unless explicitly qualifying terms such as “only,” “consisting of,” etc. are used. Unless otherwise stated, singular terms may include plural forms and should not be construed as having a quantity of one.

[0031] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0032] It is understandable that "at least one" refers to one or more, and "multiple" refers to two or more. "At least a part of an element" refers to part or all of an element.

[0033] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0034] In chip manufacturing technology, as process dimensions become smaller and smaller, the advantages of Optical Critical Dimension (OCD) measurement become increasingly apparent. It can not only measure 2D critical dimensions such as film thickness, but also measure 3D profiles. It offers fast measurement speed, high accuracy, and non-destructive operation. Currently, non-imaging optical critical dimension (OCD) measurement equipment based on diffraction optics principles has become a major tool in advanced semiconductor manufacturing processes. It can accurately measure the width of critical lines and other topographic dimensions of devices, and has excellent repeatability and long-term stability. OCD measurement can obtain many process dimension parameters at once, but these parameters usually require the use of multiple devices (such as scanning electron microscopes, atomic force microscopes, optical thin film measuring instruments, etc.) to complete.

[0035] For example, please refer to Figure 1 Currently, existing optical critical dimension measurement methods can only measure ordinary long straight lines. In semiconductor back-end processes, the patterns are relatively complex, and defects such as bridging at critical dimension positions, low normalized logarithmic slope, or incorrect pattern shape are prone to occur. If these defects are not detected in time, they can easily lead to electrical short circuits or open circuits in subsequent semiconductors, affecting semiconductor yield and product quality. Moreover, conventional critical dimension scanning electron microscopy (CD-SEM) cannot measure the depth and internal proximity of complex patterns. If transmission electron microscopy is used to measure the depth and internal proximity of complex patterns, the measurement cycle is long and online measurement is not possible.

[0036] Based on this, please refer to Figure 2This application provides an optical critical dimension measurement machine 100, including a machine body 110, a mask 120, and an optical monitoring module 130. The mask 120 is located on a stage (not shown) of the machine body 110 and includes multiple target patterns 121 arranged periodically. Each target pattern 121 includes multiple sub-patterns and at least one critical dimension position, where the critical dimension position is the position between two adjacent sub-patterns. The optical monitoring module 130 is used to measure the critical dimension information of each target pattern 121 and compare the critical dimension information with corresponding preset dimension information to monitor whether the critical dimension information is abnormal. The critical dimension information includes a first distance between two sub-patterns corresponding to the critical dimension position, the thickness of the sub-pattern, and a second distance between two adjacent target patterns.

[0037] As an example, please continue to refer to Figure 2 The optical critical dimension measurement machine 100 measures the optical critical dimensions of the target patterns 121 by placing a mask 120 comprising multiple periodically arranged target patterns 121 on a platform of the machine body 110. Each target pattern 121 includes multiple sub-patterns and at least one critical dimension position, which is the position between two adjacent sub-patterns. The critical dimension information of each target pattern 121 is measured by an optical monitoring module 130 and compared with the corresponding preset dimension information to monitor whether the critical dimension information is abnormal. This enables real-time monitoring of the critical dimension position of the target pattern during semiconductor manufacturing. If the monitored critical dimension information of the target pattern is inconsistent with the preset dimension information, defects in the semiconductor generated in each process can be detected in a timely manner, shortening the measurement time and improving the measurement efficiency. The critical dimension information includes the first spacing between the two sub-patterns corresponding to the critical dimension position, the thickness of the sub-pattern, and the second spacing between two adjacent target patterns, preventing bridging between two sub-patterns and between two adjacent target patterns, thereby improving the semiconductor yield.

[0038] In some embodiments, the target graphic includes a plurality of sub-graphics arranged in an array, the sub-graphics being strip-shaped graphics; wherein, the key dimension position is the position between two adjacent sub-graphics in the row direction of the array, and the row direction is the extension direction of the sub-graphics.

[0039] For example, please refer to Figure 3The target pattern 121 includes multiple sub-patterns 1210 arranged in an array, and the sub-patterns 1210 are strip-shaped patterns; wherein, the critical dimension position A is the position between two adjacent sub-patterns 1210 in the row direction (e.g., the OX direction) of the array, and the row direction is the extension direction of the sub-patterns 1210. The semiconductor structure prepared according to the target pattern 121 can meet the actual needs and increase the functionality of the integrated semiconductor structure. By using the optical critical dimension measurement machine in the embodiment of this application to measure the critical dimension position of the target pattern 121, the yield of the semiconductor structure including the target pattern 121 can be improved and electrical problems can be prevented.

[0040] In some embodiments, the target graphic includes a plurality of first sub-graphics and a second sub-graphic; wherein the plurality of first sub-graphics are arranged along a first direction and extend along a second direction, the second sub-graphic extends along the first direction, the second sub-graphic is located on one side of the first sub-graphic, and the first sub-graphic and the second sub-graphic are strip-shaped graphics; wherein the key dimension position is located between any of the first sub-graphics and the second sub-graphic.

[0041] It should be noted that the first direction can be the OY direction, and the second direction can be the OX direction.

[0042] For example, please refer to Figure 4 The target pattern 121 includes a plurality of first sub-patterns 1211 and a second sub-pattern 1211; wherein the plurality of first sub-patterns 1211 are arranged along a first direction and extend along a second direction, the second sub-pattern 1212 extends along the first direction, the second sub-pattern 1212 is located on one side of the first sub-pattern 1211, and the first sub-patterns 1211 and the second sub-pattern 1212 are strip-shaped patterns; wherein the critical dimension position A is located between any first sub-pattern 1211 and the second sub-pattern 1212. The semiconductor structure prepared according to the target pattern 121 can meet the actual needs and increase the functionality of the integrated semiconductor structure. By using the optical critical dimension measurement machine in the embodiment of this application to measure the critical dimension position of the target pattern 121, the yield of the semiconductor structure including the target pattern 121 can be improved and electrical problems can be prevented.

[0043] In some embodiments, the target graphic includes a plurality of third sub-graphics and a plurality of fourth sub-graphics; wherein the width dimension of the fourth sub-graphic in the first direction is greater than the width dimension of the third sub-graphic in the first direction, the length dimension of the third sub-graphic and the fourth sub-graphic in the second direction is the same, the plurality of third sub-graphics and the plurality of fourth sub-graphics are arranged in an array along the first direction, and each fourth sub-graphic is located on the outside of the array; wherein the key dimension position is located between two adjacent third sub-graphics.

[0044] For example, please refer to Figure 5The target pattern 121 includes multiple third sub-patterns 1213 and multiple fourth sub-patterns 1214. The width h1 of the fourth sub-pattern 1214 in the first direction (e.g., the OY direction) is greater than the width h2 of the third sub-pattern in the first direction (e.g., the OY direction). The length d1 of the third sub-patterns 1213 and the fourth sub-patterns 1214 in the second direction (e.g., the OX direction) is the same. The multiple third sub-patterns 1213 and the multiple fourth sub-patterns 1214 are arranged in an array along the first direction, with each fourth sub-pattern 1214 located on the outer side of the array. The critical dimension position A is located between two adjacent third sub-patterns 1213. The semiconductor structure prepared based on the target pattern 121 can meet practical needs and increase the functionality of the integrated semiconductor structure. Measuring the critical dimension position of the target pattern 121 using the optical critical dimension measuring machine in this embodiment can improve the yield of the semiconductor structure including the target pattern 121 and prevent electrical problems.

[0045] It should be noted that the width of the fourth sub-pattern in the first direction can be 200~300 nanometers, for example, 200 nanometers, 210 nanometers, 220 nanometers, 230 nanometers, 240 nanometers, 250 nanometers, 260 nanometers, 270 nanometers, 280 nanometers, 290 nanometers or 300 nanometers, etc.

[0046] In some embodiments, the target graphic includes a fifth sub-graphic and a sixth sub-graphic; wherein the fifth sub-graphic is a strip-shaped graphic and extends along a first direction, the sixth sub-graphic includes a plurality of first strip-shaped sub-graphics, and the plurality of first strip-shaped sub-graphics are connected to form an opening; a first end of the fifth sub-graphic is located at the opening, and a second end of the fifth sub-graphic is exposed outside the opening; wherein a key dimension position is located at the fifth sub-graphic, and another key dimension position is located between the fifth sub-graphic and the sixth sub-graphic.

[0047] For example, please refer to Figure 6The target pattern 121 includes a fifth sub-pattern 1215 and a sixth sub-pattern 1216. The fifth sub-pattern 1215 is a strip-shaped pattern that extends along a first direction (e.g., the OY direction). The sixth sub-pattern 1216 includes multiple first strip-shaped sub-patterns, which are connected to form an opening B. The first end of the fifth sub-pattern 1215 is located at the opening, and the second end of the fifth sub-pattern 1215 is exposed outside the opening. A critical dimension position A is located in the fifth sub-pattern 1215, and another critical dimension position A is located between the fifth sub-pattern 1215 and the sixth sub-pattern 1216. The semiconductor structure prepared according to the target pattern 121 can meet actual needs and increase the functionality of the integrated semiconductor structure. By using the optical critical dimension measurement machine in this embodiment to measure the critical dimension position of the target pattern 121, the yield of the semiconductor structure including the target pattern 121 can be improved, and electrical problems can be prevented.

[0048] In some embodiments, the target graphic includes a seventh sub-graphic and a plurality of eighth sub-graphics; wherein the seventh sub-graphic includes a plurality of second strip-shaped sub-graphics, and the plurality of second strip-shaped sub-graphics are connected to form an opening; the eighth sub-graphic is a strip-shaped graphic, and the plurality of eighth sub-graphics are arranged in an array at the opening; wherein, one key dimension position is the position between two adjacent eighth sub-graphics in the row direction of the array, and the row direction is the extension direction of the target graphic; another key dimension position is the position between two adjacent eighth sub-graphics in the column direction of the array, and yet another key dimension position is the position between adjacent seventh and eighth sub-graphics in the column direction of the array.

[0049] For example, please refer to Figure 7 The target graphic 121 includes a seventh sub-graphic 1217 and multiple eighth sub-graphics 1218; wherein the seventh sub-graphic 1217 includes multiple second strip-shaped sub-graphics, and the multiple second strip-shaped sub-graphics are connected to form an opening B. The eighth sub-pattern 1218 is a strip-shaped pattern, and multiple eighth sub-patterns 1218 are arranged in an array at the opening. Among them, one critical dimension position A is the position between two adjacent eighth sub-patterns 1218 in the row direction (e.g., the OX direction) of the array, and the row direction is the extension direction of the target pattern 121; another critical dimension position A is the position between two adjacent eighth sub-patterns 1218 in the column direction (e.g., the OY direction) of the array; and yet another critical dimension position A is the position between adjacent seventh sub-pattern 1217 and eighth sub-pattern 1218 in the column direction of the array. The semiconductor structure prepared according to the target pattern 121 can meet the actual needs and increase the functionality of the integrated semiconductor structure. By using the optical critical dimension measurement machine in this embodiment to measure the critical dimension positions of the target pattern 121, the yield of the semiconductor structure including the target pattern 121 can be improved and electrical problems can be prevented.

[0050] In some embodiments, the first spacing between two sub-patterns corresponding to the key size position ranges from 40 to 90 nanometers, for example, 40 nanometers, 50 nanometers, 60 nanometers, 70 nanometers, 80 nanometers, or 90 nanometers, etc.

[0051] In some embodiments, please refer to Figure 8 The optical critical dimension measurement instrument 100 also includes a spectral acquisition module 140 and a processing module 150. The spectral acquisition module 140 is used to acquire spectral information at each critical dimension position. The processing module 150 is connected to the spectral acquisition module 140 and is used to store a preset critical dimension measurement model and the corresponding simulated spectral information, as well as to verify whether the preset critical dimension measurement model is consistent with the target graphic based on the spectral information and the simulated spectral information. The preset dimension information is determined by the preset critical dimension measurement model. By comparing the acquired spectral information with the simulated spectral information corresponding to the preset critical dimension measurement model, the reliability of the preset critical dimension measurement model can be accurately verified, thereby improving the accuracy of model measurement.

[0052] In some embodiments, the photomask can be sliced ​​along its thickness direction, and the key dimensions of the target pattern can be observed using a transmission electron microscope (TEM). The TEM transmits an accelerated and focused electron beam onto the photomask. The electrons collide with atoms in the photomask and change direction, resulting in solid-angle scattering. The size of the scattering angle is related to the density and thickness of the photomask, thus forming images of varying brightness. After magnification and focusing, the images are displayed on an imaging device (such as a fluorescent screen, film, or photocoupler), allowing for accurate determination of the key dimensions of the target pattern.

[0053] In some embodiments, please refer to Figure 9The spectral acquisition module 140 includes an etching site spectral acquisition unit 141 and a grinding site spectral acquisition unit 142. The etching site spectral acquisition unit 141 is used to acquire the first emission spectrum of the key dimension position after the mask is etched; the grinding site spectral acquisition unit 142 is used to acquire the second emission spectrum of the key dimension position after the mask is ground. The waveforms of the first emission spectrum and the second emission spectrum are different. The spectral information includes at least one of the first emission spectrum and the second emission spectrum. After the first emission spectrum and the second emission spectrum are acquired, a spectral simulation is performed on the preset key dimension measurement model to obtain the simulated first emission spectrum and the simulated second emission spectrum. The simulated spectral information includes the simulated first emission spectrum and the simulated second emission spectrum. The acquired spectral information is then compared with the simulated spectral information corresponding to the preset key dimension measurement model. The waveforms of the first emission spectrum and the simulated first emission spectrum are compared to see if they are consistent, and the waveforms of the second emission spectrum and the simulated second emission spectrum are compared to see if they are consistent. This allows for a precise determination of whether the preset key dimension measurement model can be used for measurement, thereby improving the accuracy of the measurement.

[0054] It should be noted that the first and second emission spectra in the visible light band were collected, and the range of the collected spectra in the visible light band is 240~860 nanometers.

[0055] In some embodiments, please refer to Figure 10 The optical critical dimension measurement machine 100 also includes a storage module 160, which is connected to the processing module 150 and is used to store the critical dimension positions and preset dimension information corresponding to multiple target graphics. This can provide a reference for parameter settings in subsequent process manufacturing.

[0056] For example, please refer to Figure 11The mask 120 includes a plurality of target patterns 121 arranged periodically. Each target pattern 121 includes a seventh sub-pattern 1217 and a plurality of eighth sub-patterns 1218. The seventh sub-pattern 1217 includes a plurality of second strip-shaped sub-patterns, and the plurality of second strip-shaped sub-patterns are connected to form an opening. The eighth sub-patterns 1218 are strip-shaped patterns, and the plurality of eighth sub-patterns 1218 are arranged in an array at the opening. A key dimension position A is the position between two adjacent eighth sub-patterns 1218 in the row direction (e.g., the OX direction) of the array, where the row direction is the extension direction of the target pattern 121. Another key dimension position A is the position between two adjacent eighth sub-patterns 1218 in the column direction (e.g., the OY direction) of the array. A third key dimension position A is the position between adjacent seventh sub-patterns 1217 and eighth sub-patterns 1218 in the column direction of the array. An optical monitoring module is used to measure the critical dimension information of each target pattern 121 and compare it with the corresponding preset dimension information to monitor whether the critical dimension information is abnormal. The critical dimension information includes the first distance d2 between the two sub-patterns corresponding to the critical dimension position A, the thickness of the sub-pattern (not shown), and the second distance d3 between two adjacent target patterns 121. The optical critical dimension measurement instrument in this embodiment monitors the critical dimension position of the target pattern 121 without semiconductor damage. By comparing the critical dimension information with the corresponding preset dimension information, the defect position is accurately monitored, avoiding the waste of resources caused by discovering problems only during electrical testing, shortening the measurement time, and improving the measurement efficiency.

[0057] The unexpected technical effects of this application are as follows: By placing a mask containing multiple periodically arranged target patterns on the platform of the machine body, optical key dimension measurement of the target patterns is performed. The key dimension information of each target pattern is measured by an optical monitoring module, and the key dimension information is compared with the corresponding preset dimension information to monitor whether the key dimension information is abnormal. Real-time monitoring of the three-dimensional key dimensions of the target pattern can be achieved, and the defect location can be detected in time. This avoids the waste of resources caused by discovering problems only after electrical measurement. Furthermore, optical measurement is more accurate and does not damage semiconductors, thereby improving measurement efficiency and semiconductor yield.

[0058] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0059] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0060] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. An optical critical dimension measuring machine, characterized in that, include: Machine body; A photomask is located on the platform of the machine body. The photomask includes multiple target patterns arranged periodically. Each target pattern includes multiple sub-patterns and at least one key dimension position, wherein the key dimension position is the position between two adjacent sub-patterns. An optical monitoring module is used to measure the key dimension information of each target graphic and compare the key dimension information with the corresponding preset dimension information to monitor whether the key dimension information is abnormal; the key dimension information includes the first distance between the two sub-graphics corresponding to the key dimension position, the thickness of the sub-graphic, and the second distance between two adjacent target graphics.

2. The optical critical dimension measuring machine according to claim 1, characterized in that, The target graphic includes multiple sub-graphics arranged in an array, and the sub-graphics are strip-shaped graphics; wherein, The key dimension position is the position between two adjacent sub-patterns in the row direction of the array, where the row direction is the extension direction of the sub-pattern.

3. The optical critical dimension measuring machine according to claim 1, characterized in that, The target graphic includes multiple first sub-graphics and one second sub-graphic; wherein the multiple first sub-graphics are arranged along a first direction and extend along a second direction, the second sub-graphic extends along the first direction, the second sub-graphic is located on one side of the first sub-graphic, and the first and second sub-graphics are both strip-shaped graphics; wherein... The key dimension position is located between any of the first sub-graphics and the second sub-graphics.

4. The optical critical dimension measuring machine according to claim 1, characterized in that, The target graphic includes multiple third sub-graphics and multiple fourth sub-graphics; wherein, the width dimension of the fourth sub-graphic in the first direction is greater than the width dimension of the third sub-graphic in the first direction, the length dimension of the third sub-graphic and the fourth sub-graphic in the second direction is the same, the multiple third sub-graphics and the multiple fourth sub-graphics are arranged in an array along the first direction, and each of the fourth sub-graphics is located outside the array; The key dimension position is located between two adjacent third sub-figures.

5. The optical critical dimension measuring machine according to claim 1, characterized in that, The target graphic includes a fifth sub-graphic and a sixth sub-graphic; wherein... The fifth sub-graphic is a strip-shaped graphic that extends along a first direction. The sixth sub-graphic includes multiple first strip-shaped sub-graphics, and the multiple first strip-shaped sub-graphics are connected to form an opening. The first end of the fifth sub-graphic is located in the opening, and the second end of the fifth sub-graphic is exposed outside the opening. One of the key dimension positions is located in the fifth sub-graphic, and the other key dimension position is located between the fifth sub-graphic and the sixth sub-graphic.

6. The optical critical dimension measuring machine according to claim 1, characterized in that, The target graphic includes a seventh sub-graphic and multiple eighth sub-graphics; wherein... The seventh sub-graphic includes multiple second strip-shaped sub-graphics, and the multiple second strip-shaped sub-graphics are connected to form an opening; The eighth sub-graphic is a strip-shaped graphic, and multiple eighth sub-graphics are arranged in an array at the opening; wherein... One of the key dimension positions is the position between two adjacent eighth sub-figures in the row direction of the array, where the row direction is the extension direction of the target figure; another key dimension position is the position between two adjacent eighth sub-figures in the column direction of the array; and yet another key dimension position is the position between adjacent seventh and eighth sub-figures in the column direction of the array.

7. The optical critical dimension measuring machine according to claim 1, characterized in that, The first spacing between the two sub-patterns corresponding to the key dimension position ranges from 40 to 90 nanometers.

8. The optical critical dimension measuring machine according to claim 1, characterized in that, Also includes: A spectral acquisition module is used to acquire spectral information at each of the aforementioned key dimensions. A processing module, connected to the spectral acquisition module, is used to store a preset key dimension measurement model and the simulated spectral information corresponding to the preset key dimension measurement model, and to verify whether the preset key dimension measurement model is consistent with the target graphic based on the spectral information and the simulated spectral information; wherein, the preset dimension information is determined by the preset key dimension measurement model.

9. The optical critical dimension measuring machine according to claim 8, characterized in that, The spectral acquisition module includes: An etching site spectral acquisition unit is used to acquire the first emission spectrum at key size locations after the mask is etched. A grinding station spectral acquisition device is used to acquire a second emission spectrum at a key dimension location after the mask has been ground, wherein the waveforms of the first emission spectrum and the second emission spectrum are different; wherein the spectral information includes at least one of the first emission spectrum and the second emission spectrum.

10. The optical critical dimension measuring machine according to claim 1, characterized in that, Also includes: A storage module, connected to the processing module, is used to store key size positions and preset size information corresponding to multiple target graphics.

Images