Combined marks on a reticle

Abstract

The utility model provides a kind of combination mark on reticle, comprising: front layer combination mark and when layer combination mark, front layer combination mark includes first front layer mark and second front layer mark, and second front layer mark surrounds first front layer mark;Front layer combination mark surrounds when layer combination mark, and when layer combination mark includes first when layer mark and second when layer mark, and second when layer mark surrounds part first when layer mark;Wherein, along the extension direction of first front layer mark, second front layer mark, first when layer mark and second when layer mark, first front layer mark, second front layer mark, first when layer mark and second when layer mark are all divided into first part and second part, and the width of first part and second part is different, and first part and second part have phase difference.The utility model can measure and obtain overlay value and monitor machine focal length simultaneously, improve capacity utilization.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor technology, and in particular to a combination mark on a photomask. Background Technology

[0002] Phase Shift Focus Monitoring (PSFM) is a method for determining the focal length of an exposure machine. Its main function is to measure the overlay values ​​at different focal lengths using box-in-box (BIB) overlapping markers, thereby obtaining the relationship between focal length and overlay value. This allows for the determination of the machine's focal length using PSFM photomask measurements of the overlay values. Currently, PSFM requires engineers to perform the monitoring on the machine, resulting in high labor and downtime costs. Furthermore, it only assesses the machine's condition over a specific period by monitoring changes over time, lacking real-time responsiveness. Utility Model Content

[0003] The purpose of this invention is to provide a combined mark on a photomask that can simultaneously measure the overlay value and monitor the focal length of the machine, thereby improving production capacity utilization.

[0004] To achieve the above objectives, this utility model provides a combined marking on a photomask, comprising:

[0005] The front layer combination mark includes a first front layer mark and a second front layer mark, wherein the second front layer mark surrounds the first front layer mark;

[0006] The current layer combination mark is surrounded by the previous layer combination mark, and the current layer combination mark includes a first current layer mark and a second current layer mark. The first previous layer mark and the first current layer mark are centrally symmetrical about the same center, and the second current layer mark surrounds a portion of the first current layer mark.

[0007] Wherein, along the extending direction of the first front layer mark, the second front layer mark, the first current layer mark and the second current layer mark, the first front layer mark, the second front layer mark, the first current layer mark and the second current layer mark are all divided into a first part and a second part, the width of the first part and the second part are different, and the first part and the second part have a phase difference.

[0008] Optionally, the width of the first part is greater than the width of the second part.

[0009] Optionally, both the first and second portions include a pattern layer located on a transparent substrate of the photomask; the second portion further includes a chromium layer located on the pattern layer.

[0010] Optionally, the width of the chromium layer is the same as the width of the second portion.

[0011] Optionally, the phase difference between the first part and the second part is 90 degrees or 180 degrees.

[0012] Optionally, the width of the first front layer mark and the width of the first current layer mark are the same, and the width of the second front layer mark and the width of the second current layer mark are the same.

[0013] Optionally, the width of the first front layer mark and the first current layer mark is 6µm to 12µm, and the width of the second front layer mark and the second current layer mark is 12µm to 24µm.

[0014] Optionally, the width of the first front layer mark and the first current layer mark are the same, and the width of the first portion of the second front layer mark and the second current layer mark are the same.

[0015] Optionally, the first front layer mark is divided into several groups, and the several groups of the first front layer mark form a centrally symmetrical figure; the first current layer mark is divided into several groups, and the several groups of the first current layer mark form a centrally symmetrical figure; the second current layer mark surrounds part of the first current layer mark group, and the remaining groups of the first current layer mark group are located outside the second current layer mark group.

[0016] Optionally, the patterns of the first front layer marker and the first current layer marker are of advanced image measurement type, and the patterns of the second front layer marker and the second current layer marker constitute inner and outer bar or inner and outer box type.

[0017] The combined markings on the photomask provided by this utility model include: a front layer combined marking and a current layer combined marking. The front layer combined marking includes a first front layer marking and a second front layer marking, with the second front layer marking surrounding the first front layer marking. The front layer combined marking surrounds the current layer combined marking, and the current layer combined marking includes a first current layer marking and a second current layer marking. The first front layer marking and the first current layer marking are centrally symmetrical about the same center. The second current layer marking surrounds a portion of the first current layer marking. Along the extending direction of the first front layer marking, the second front layer marking, the first current layer marking, and the second current layer marking are all divided into a first part and a second part, and the widths of the first part and the second part are different, and the first part and the second part have a phase difference. In this invention, the first front layer mark, the second front layer mark, the first current layer mark, and the second current layer mark are all divided into a first part and a second part. The widths of the first part and the second part are different, and the first part and the second part have a phase difference, so that the first front layer mark, the second front layer mark, the first current layer mark, and the second current layer mark all form an asymmetrical phase difference, thereby creating a focal length difference. The unexpected technical effect is that it is possible to simultaneously measure and obtain the overlay value and monitor the focal length of the machine, effectively saving labor costs and downtime costs, and improving production capacity utilization. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the front layer composite mark in the composite mark on the photomask provided in an embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of the combined markings in the same layer on the photomask provided in an embodiment of the present invention.

[0020] Figure 3 This is a schematic diagram of the combined markings on a photomask provided in an embodiment of the present invention.

[0021] Figure 4 This is a partially enlarged schematic diagram of the combined markings on the photomask provided in an embodiment of the present invention.

[0022] Figure 5 This is a partial cross-sectional schematic diagram of the combined markings on the photomask provided in an embodiment of the present invention.

[0023] Figure 6 This is a schematic diagram of the second front layer mark and the second current layer mark in the combined markings on the photomask provided in an embodiment of the present invention.

[0024] Figure 7 This is a schematic diagram of the first front layer mark and the first current layer mark in the combined markings on the photomask provided in an embodiment of the present invention.

[0025] The attached figures are labeled as follows:

[0026] 10 - Front layer combination mark; 11 - First front layer mark; 12 - Second front layer mark; 20 - Current layer combination mark; 21 - First current layer mark; 22 - Second current layer mark; 11a - First part of the first front layer mark; 11b - Second part of the first front layer mark; 21a - First part of the first current layer mark; 21b - Second part of the first current layer mark; 100 - Transparent substrate; 110 - Graphic layer of the first front layer mark; 120 - Chromium layer of the first front layer mark; 210 - Graphic layer of the first current layer mark; 220 - Chromium layer of the first current layer mark. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0029] In the description of this application, it should be understood that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are used only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the equipment or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0030] Furthermore, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or apparatus that includes said element. Those skilled in the art will understand the specific meaning of the above terms in this application based on the specific circumstances.

[0031] Figure 1 This is a schematic diagram of the front layer composite mark in the composite mark on the photomask provided in this embodiment. Figure 2 This is a schematic diagram of the combined markings on the photomask provided in this embodiment. Figure 3 This is a schematic diagram of the combined markings on the photomask provided in this embodiment. Please refer to... Figures 1-3 This utility model provides a combination mark on a photomask. The combination mark is set on the photomask to simultaneously measure the overlay value and monitor the focal length of the monitoring equipment. The combination mark includes a front combination mark 10 and a current combination mark 20. The front combination mark 10 includes a first front mark 11 and a second front mark 12. The first front mark 11 is divided into several groups, and the several groups of first front marks 11 form a centrally symmetrical pattern. Figure 1 The diagram illustrates that the first front layer mark 11 is divided into 4 groups (each dotted box indicates one group of first front layer marks 11), and the 4 groups of first front layer marks 11 form a centrally symmetrical figure. In this embodiment, the first front layer mark 11 is strip-shaped, and the length and width of each first front layer mark 11 are preferably the same; the spacing between two adjacent first front layer marks 11 in each group is preferably the same, and the number of first front layer marks 11 in each group is preferably the same. Figure 1 The diagram illustrates that there are 7 first front layer marks 11 in each group of first front layer marks 11; the extension direction of the first front layer marks 11 in each group of first front layer marks 11 is the same, and the extension directions of adjacent groups of first front layer marks 11 are perpendicular.

[0032] The second front layer mark 12 surrounds the first front layer mark 11. Specifically, the second front layer mark 12 is strip-shaped, and there are four second front layer marks 12. The four second front layer marks 12 extend in different directions, so that the four second front layer marks 12 surround the first front layer mark 11 from all sides. Adjacent second front layer marks 12 may or may not be connected. Figure 1 The diagram illustrates that two adjacent second front layer marks 12 are not connected. In this embodiment, the length of each second front layer mark 12 is preferably the same, the width of each second front layer mark 12 is preferably the same, and the length of the first front layer mark 11 is less than the length of the second front layer mark 12.

[0033] The layer combination mark 20 includes a first layer mark 21 and a second layer mark 22. The first layer mark 21 is divided into several groups, and these groups of first layer marks 21 form a centrally symmetrical figure. The second layer mark 22 surrounds a portion of the first layer mark 21. Specifically, the second layer mark 22 surrounds a portion of the first layer mark 21, and the remaining groups of first layer mark 21 are located outside the second layer mark 22. The second layer mark 22 is strip-shaped, and there are four second layer marks 22. The four second layer marks 22 extend in different directions, so that the four second layer marks 22 surround a portion of the first layer mark 21 from all sides. Adjacent second layer marks 22 may or may not be connected. Figure 2 The diagram illustrates that two adjacent second-layer markers 22 are not connected. Figure 2 The diagram illustrates that the first layer mark 21 is divided into 8 groups (each dotted box indicates one group of the first layer mark 21), the 8 groups of the first layer mark 21 form a centrally symmetrical figure, the second layer mark 22 surrounds 4 groups of the first layer mark 21, and the remaining 4 groups are located outside the corresponding second layer mark 22.

[0034] In this embodiment, the first layer marker 21 is strip-shaped. The length and width of each first layer marker 21 located inside the second layer marker 22 are preferably the same. Similarly, the length and width of each first layer marker 21 located outside the second layer marker 22 are preferably the same. The spacing between adjacent first layer markers 21 in each group is preferably the same, and the number of first layer markers 21 in each group is preferably the same. Figure 2 The diagram illustrates that there are three first layer markers 21 in each group of first layer markers 21. The first layer markers 21 in each group extend in the same direction. The extension directions of two adjacent groups of first layer markers 21 located inside the second layer marker 22 are perpendicular. The extension direction of each group of first layer markers 21 located outside the second layer marker 22 is the same as the extension direction of its adjacent second layer marker 22. The length of the first layer marker 21 is less than the length of the second layer marker 22. The length of each second layer marker 22 is preferably the same, and the width of each second layer marker 22 is preferably the same.

[0035] The preceding combination mark 10 surrounds the current combination mark 20. Figure 3 The diagram illustrates two types of fill representations: front layer combination mark 10 and current layer combination mark 20. The first front layer mark 11 and the first current layer mark 21 are centrally symmetrical about the same center.

[0036] Along the extending directions of the first front layer mark 11, the second front layer mark 12, the first current layer mark 21, and the second current layer mark 22, each of these marks is divided into a first part and a second part, with different widths and a phase difference. In this embodiment, the different widths of the first and second parts create asymmetry; specifically, the width of the first part is greater than the width of the second part. Both the first and second parts include a pattern layer located on the transparent substrate of the photomask. The second part also includes a chromium layer located on the pattern layer, with the width of the chromium layer being the same as the width of the second part. By setting the chromium layer on the pattern layer in the second part, a phase difference is created between the first and second parts. The different widths of the first and second parts result in an asymmetric phase difference, causing a focal length difference. This allows for the measurement of overlay values ​​and monitoring of the machine's focal length, effectively saving labor and downtime costs and improving production capacity utilization.

[0037] In this embodiment, the phase difference between the first part and the second part is 90 degrees or 180 degrees. The light source of the exposure machine generates incident light that enters the first part and the second part (the incident light has the same phase). After passing through the first part and the second part, it forms outgoing light. Through the above arrangement, the phases of the outgoing light from the first part and the second part are different. Specifically, the phase of the outgoing light from the first part is greater than the phase of the outgoing light from the second part. For example, if the phase of the outgoing light from the first part is θ, the phase of the outgoing light from the second part is 0, that is, the phase difference between the outgoing light from the first part and the second part is θ, where θ is 90 degrees or 180 degrees. The first front layer mark 11, the second front layer mark 12, the first current layer mark 21, and the second current layer mark 22 are all divided into a first part and a second part, indicating that all marks are divided into a first part and a second part, and both the first part and the second part have all the above-mentioned features, not targeting a single mark.

[0038] Figure 4 This is a partially enlarged schematic diagram of the combined markings on the photomask provided in this embodiment. Figure 5 This is a partial cross-sectional schematic diagram of the combined markings on the photomask provided in this embodiment, wherein... Figure 4 for Figure 3 Enlarged diagram at point B in the middle. Figure 5 for Figure 4 A schematic diagram of cross-sections along section lines A1A2 and B1B2, and in Figure 5The diagram illustrates the emitted light waveform T. Please refer to it. Figure 4 , Figure 4 The diagram illustrates that the first front layer mark 11 and the first current layer mark 21 are divided into a first part and a second part. Along the extension direction D2 of the first front layer mark 11, the first front layer mark 11 is divided into a first part 11a and a second part 11b. Similarly, along the extension direction D2 of the first current layer mark 21, the first current layer mark 21 is divided into a first part 21a and a second part 21b. Along the width direction D1 of the first front layer mark 11, the width of the first part 11a is greater than the width of the second part 11b. Likewise, along the width direction D1 of the first current layer mark 21, the width of the first part 21a is greater than the width of the second part 21b.

[0039] Please refer to Figure 5 Both the first portion 11a and the second portion 11b of the first front layer mark include a graphic layer 110 of the first front layer mark, which is located on the transparent substrate 100. The second portion 11b of the first front layer mark also includes a chromium layer 120 of the first front layer mark, which is located on the graphic layer 110 of the first front layer mark, and the width of the chromium layer 120 of the first front layer mark is the same as that of the second portion 11b of the first front layer mark. Both the first portion 21a and the second portion 21b of the first back layer mark include a graphic layer 210 of the first back layer mark, which is located on the transparent substrate 100. The second portion 21b of the first back layer mark also includes a chromium layer 220 of the first back layer mark, which is located on the graphic layer 210 of the first back layer mark, and the width of the chromium layer 220 of the first back layer mark is the same as that of the second portion 21b of the first back layer mark.

[0040] Incident light of the same phase is incident on the first current layer mark 21 and the first front layer mark 11. After passing through the first current layer mark 21 and the first front layer mark 11, the outgoing light waveform T is obtained. According to the outgoing light waveform T, it can be seen that the first part 11a and the second part 11b of the first front layer mark, as well as the first part 21a and the second part 21b of the first current layer mark, have a phase difference. Figure 4 and Figure 5 The examples further clarify the characteristics of the first and second parts.

[0041] Figure 6 This is a schematic diagram of the second front layer mark and the second current layer mark in the combined markings on the photomask provided in this embodiment. Figure 7This is a schematic diagram of the first front layer mark and the first current layer mark in the combined markings on the photomask provided in this embodiment. Please refer to... Figure 6 The widths of the second front layer mark 12 and the second current layer mark 22 are preferably the same. The widths of the first portions of the second front layer mark 12 and the second current layer mark 22 are preferably the same. The widths of the second portions of the second front layer mark 12 and the second current layer mark 22 are preferably the same. The widths of the second front layer mark 12 and the second current layer mark 22 can be 12µm to 24µm, and are not limited thereto. Furthermore, the graphics of the second front layer mark 12 and the second current layer mark 22 form inner and outer stripes or inner and outer boxes. Figure 6 The diagram illustrates the inner and outer bars. Please refer to it. Figure 7 The widths of the first front layer mark 11 and the first current layer mark 21 are preferably the same. The widths of the first portions of the first front layer mark 11 and the first current layer mark 21 are preferably the same. The widths of the second portions of the first front layer mark 11 and the first current layer mark 21 are preferably the same. The widths of the first front layer mark 11 and the first current layer mark 21 can be 6µm to 12µm, and are not limited thereto. Furthermore, the graphic of the first front layer mark 11 and the first current layer mark 21 is of the Advanced Imaging Metrology (AIM) type.

[0042] In summary, the combined markings on the photomask provided by this utility model include: a front layer combined marking and a current layer combined marking. The front layer combined marking includes a first front layer marking and a second front layer marking, with the second front layer marking surrounding the first front layer marking. The front layer combined marking surrounds the current layer combined marking, and the current layer combined marking includes a first current layer marking and a second current layer marking. The first front layer marking and the first current layer marking are centrally symmetrical about the same center. The second current layer marking surrounds a portion of the first current layer marking. Along the extending direction of the first front layer marking, the second front layer marking, the first current layer marking, and the second current layer marking are all divided into a first part and a second part, and the widths of the first part and the second part are different, and the first part and the second part have a phase difference. In this invention, the first front layer mark, the second front layer mark, the first current layer mark, and the second current layer mark are all divided into a first part and a second part. The widths of the first part and the second part are different, and the first part and the second part have a phase difference, so that the first front layer mark, the second front layer mark, the first current layer mark, and the second current layer mark all form an asymmetrical phase difference, thereby creating a focal length difference. The unexpected technical effect is that it is possible to simultaneously measure and obtain the overlay value and monitor the focal length of the machine, effectively saving labor costs and downtime costs, and improving production capacity utilization.

[0043] The above are merely preferred embodiments of this utility model and do not constitute any limitation on this utility model. Any equivalent substitutions or modifications made by those skilled in the art to the technical solutions and contents disclosed in this utility model without departing from the scope of the technical solutions of this utility model shall still fall within the protection scope of this utility model.

Claims

1. A combination of markings on a photomask, characterized in that, include: The front layer combination mark includes a first front layer mark and a second front layer mark, wherein the second front layer mark surrounds the first front layer mark; The current layer combination mark is surrounded by the previous layer combination mark, and the current layer combination mark includes a first current layer mark and a second current layer mark. The first previous layer mark and the first current layer mark are centrally symmetrical about the same center, and the second current layer mark surrounds a portion of the first current layer mark. Wherein, along the extending direction of the first front layer mark, the second front layer mark, the first current layer mark and the second current layer mark, the first front layer mark, the second front layer mark, the first current layer mark and the second current layer mark are all divided into a first part and a second part, the width of the first part and the second part are different, and the first part and the second part have a phase difference.

2. The combined markings on the photomask as described in claim 1, characterized in that, The width of the first part is greater than the width of the second part.

3. The combined markings on the photomask as described in claim 1, characterized in that, Both the first part and the second part include a pattern layer located on a transparent substrate of the photomask; the second part also includes a chromium layer located on the pattern layer.

4. The combined markings on the photomask as described in claim 3, characterized in that, The width of the chromium layer is the same as the width of the second portion.

5. The combined markings on the photomask as described in claim 1, characterized in that, The phase difference between the first part and the second part is 90 degrees or 180 degrees.

6. The combined markings on the photomask as described in claim 1, characterized in that, The first front layer mark and the first current layer mark have the same width, and the second front layer mark and the second current layer mark have the same width.

7. The combined markings on the photomask as described in claim 6, characterized in that, The width of the first front layer mark and the first current layer mark is 6µm to 12µm, and the width of the second front layer mark and the second current layer mark is 12µm to 24µm.

8. The combined markings on the photomask as described in claim 6, characterized in that, The width of the first front layer mark and the first current layer mark are the same, and the width of the first portion of the second front layer mark and the second current layer mark are the same.

9. The combined markings on the photomask as described in claim 1, characterized in that, The first front layer mark is divided into several groups, and the several groups of the first front layer mark form a centrally symmetrical figure; the first current layer mark is divided into several groups, and the several groups of the first current layer mark form a centrally symmetrical figure; the second current layer mark surrounds part of the first current layer mark group, and the remaining groups of the first current layer mark group are located outside the second current layer mark.

10. The combined markings on the photomask as described in claim 1, characterized in that, The first front layer marker and the first current layer marker are of advanced image measurement type, and the second front layer marker and the second current layer marker are of inner and outer bar type or inner and outer box type.

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