Photomask repair process
By setting the anti-bias point of chromium material on the photomask and repairing it with electron beam repair equipment, the problems of low repair efficiency and unstable process are solved, and high accuracy and efficient repair results are achieved.
Patent Information
- Application Number
- CN202411367350.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-27
- Publication Date
- 2024-12-27
AI Technical Summary
The repair efficiency of large-size defects in the existing photomask repair process is low, which can easily lead to repair failure and process instability caused by long-term repair.
Several groups of anti-bias points are set on the photomask. Each group of anti-bias points has more than 1 material, and the material is chromium. The electron beam repair equipment is used to repair defects based on these anti-bias points, and the anti-bias points are retained after the repair is completed. .
It effectively prevents repair failures caused by long-term repair, improves the accuracy and efficiency of photomask repair, and ensures complete repair of large-size defects.
Smart Images
Figure CN119200322A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of semiconductor technology, and in particular to a photomask repair process. Background Art
[0002] The quality requirement for photomask products is zero defects, which requires that when defects appear in the photomask, the defects need to be repaired. Due to factors such as long defect repair time, complex repair parameters, and multiple repair rounds, large-size defects become a defect with a higher repair risk during the repair process. Currently, block repair methods are usually used to splice the repair area for large-size defects. The disadvantages of block repair are: 1. Low repair efficiency, requiring multiple rounds of repair time; 2. Poor repair effect, the splicing part is often unable to be automatically identified by the system, and manual intervention is required. In the process of manual intervention, it will cause inevitable deviations. When the graphics are more complex, the deviation is more obvious; 3. Large-scale repair will lead to extremely long repair time, and extremely long repair time makes the process unstable. Summary of the invention
[0003] The object of the present invention is to provide a photomask repair process, which can effectively prevent repair failure caused by long-term repair, thereby improving the accuracy of photomask repair.
[0004] In order to achieve the above object, the present invention provides a photomask repair process, comprising:
[0005] A photomask is provided, wherein the photomask has a mask pattern and defects, and the mask pattern is provided with a plurality of groups of anti-deflection points, the number of the anti-deflection points in each group is greater than one, and the material of the anti-deflection points includes chromium;
[0006] The defect is repaired based on the anti-deflection point by using electron beam repair equipment to complete the repair of the defect, and the anti-deflection point is retained after the repair is completed.
[0007] Optionally, at least one dimension of the defect is larger than 2 μm.
[0008] Optionally, the defect is rectangular, two adjacent sides of the defect have a first size and a second size respectively, and the first size and / or the second size is greater than 2 μm.
[0009] Optionally, the number of the anti-deviation points in each group is greater than 1 and less than or equal to 4.
[0010] Optionally, any dimension of the defect is greater than 2 μm and less than 4 μm or each dimension of the defect is greater than 2 μm and less than 4 μm, the number of anti-bias points in each group is 2, the diameter of the anti-bias point is 12 nm, and the distance between two anti-bias points is 0.02 times the maximum dimension of the defect.
[0011] Optionally, any size of the defect is greater than 4 μm, the number of the anti-deflection points in each group is 3, the diameter of the anti-deflection points is 10 nm, and the distance between two adjacent anti-deflection points is 0.015 times the maximum size of the defect.
[0012] Optionally, each dimension of the defect is greater than 4 μm, the number of the anti-deflection points in each group is 4, the diameter of the anti-deflection points is 7 nm, and the distance between two adjacent anti-deflection points is 0.01 times the maximum dimension of the defect.
[0013] Optionally, the diameter of the anti-deflection point is 1nm to 15nm, and the anti-deflection point is formed on the mask pattern by a deposition process. During the formation of the anti-deflection point, the number of deposition cycles is 1 to 1000 times, the number of deposition halo suppression is 1 to 5 times, and the deposition halo suppression pixels are 1 pixel to 3000 pixels.
[0014] Optionally, during the formation of the anti-deflection point, the introduced gas includes hexahydroxychromium.
[0015] Optionally, the defect is repaired by an etching repair process.
[0016] The photomask repair process provided by the present invention includes: providing a photomask, the photomask having a mask pattern and a defect, and a plurality of groups of anti-deflection points are arranged on the mask pattern, the number of each group of anti-deflection points is greater than one, and the material of the anti-deflection points includes chromium; using an electron beam repair device, repairing the defect based on the anti-deflection points to complete the repair of the defect, and the anti-deflection points are retained after the repair is completed. The present invention sets the number of anti-deflection points in each group and the material of the anti-deflection points, the number of each group of anti-deflection points is greater than one, and the material of the anti-deflection points includes chromium, so that the anti-deflection points will not be consumed due to long-term repair, and the electron beam repair device is used to repair the defect based on the anti-deflection points, and the anti-deflection points are retained after the repair is completed, which can effectively prevent the repair failure caused by long-term repair, thereby improving the accuracy of photomask repair. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 A schematic diagram of a photomask having no defects.
[0018] Figure 2 A schematic diagram of a photomask having defects.
[0019] Figure 3 A schematic diagram of setting an anti-deflection point when there are defects on a photomask.
[0020] Figure 4 A schematic diagram of a photomask having defects after anti-deflection points are set to repair the defects.
[0021] Figure 5 This is a partial imaging picture of a photomask under an electron microscope.
[0022] Figure 6 This is a partial imaging picture under an electron microscope after a defect is repaired with a photomask.
[0023] Figure 7 A flow chart of a photomask repair process provided by one embodiment of the present invention.
[0024] Figure 8 to Figure 10 A schematic diagram of a photomask in a photomask repair process provided by an embodiment of the present invention.
[0025] Fig.11 A partial imaging picture under an electron microscope in a photomask repair process provided by one embodiment of the present invention.
[0026] Fig.12 A partial imaging picture under an electron microscope after a defect is repaired in a photomask repair process provided by an embodiment of the present invention.
[0027] Wherein, the accompanying drawings are marked as follows:
[0028] 10, 100 - photomask; 20, 200 - mask pattern; 30, 300 - defect; 40, 400 - anti-bias point. DETAILED DESCRIPTION
[0029] Figure 1 is a schematic diagram of a photomask without defects, Figure 2 A schematic diagram of a defect on a photomask. Figure 1 , the photomask 10 is a COG (Chrome on Glass) photomask, and the photomask 10 has a plurality of strip-shaped mask patterns 20. The mask patterns 20 in the figure are only examples, and the photomask 10 has no defects; please refer to Figure 2 The photomask 10 has a plurality of strip-shaped mask patterns 20, the mask patterns 20 in the figure are only examples, the photomask 10 has a defect 30, the defect 30 is connected to the mask pattern 20, the material of the defect 30 is the same as the material of the mask pattern 20, both are chromium, the defect 30 can be rectangular, and the two adjacent sides (length and width) of the defect 30 have a first size d1 and a second size d2 respectively, and a repair process is required to be used to repair the defect 30 to remove it.
[0030] Figure 3 A schematic diagram of setting an anti-deflection point when there are defects on a photomask. Figure 4 This is a schematic diagram of a photomask with defects after anti-deflection points are set to repair them. Please refer to Figure 3, an anti-deflection point 40 is respectively set at four positions (set according to actual conditions) on the mask pattern 20, and the diameter of the anti-deflection point 40 can be 15nm; please refer to Figure 4 Setting the anti-deflection point 40 can help find the position of the defect 30. Figure 3 The defect 30 in the Figure 4 , Figure 4 There is no defect after the repair. In theory, the four anti-deflection points 40 will not disappear during the repair process, and the four anti-deflection points 40 will remain on the mask pattern 20 after the repair (such as Figure 4 As shown in FIG. 1 , the four anti-deflection points 40 after repair will not affect the imaging of the photomask 10.
[0031] However, when the size of the defect is large, the repair process will increase exponentially, the repair time will be long, and the defect cannot be repaired. Table 1 shows the repair results of defects of different sizes. Please refer to Table 1. When the first size and the second size of the defect are both less than 2μm, the defect is repaired using four anti-bias points, and the repair result is that the defect can be repaired and removed; when at least one size of the defect (the first size and / or the second size) is greater than 2μm, the defect is repaired using four anti-bias points, and the repair result is that there is a risk of repair failure or repair failure.
[0032] First size (μm) Second size (μm) Repair results 0～2 0～2 Repairable 0～2 2～4 Risk of patch failure 0～2 Greater than 4 Patching failure 2～4 2～4 Risk of patch failure 2～4 Greater than 4 Patching failure Greater than 4 Greater than 4 Patching failure
[0033] Table 1. Repair results of defects of different sizes
[0034] Figure 5 This is a partial imaging picture of a photomask under an electron microscope; Figure 6 This is a partial image of a photomask after repairing defects under an electron microscope. Please refer to Figure 5 , which shows part of the mask pattern of the photomask. The circled position in the figure is a set anti-deflection point; please refer to Figure 6 The square in the figure is the repair area (equivalent to the defect). The size of the repair area is greater than 4μm. The repair area is etched and repaired. It can be seen from the figure that the etching process of the repair area has not yet ended, but the repair time is long due to the large defect area, resulting in the set anti-bias point being consumed (the anti-bias point at the circled position in the figure has disappeared), thereby forcing the repair process to end early, but the repair is not completed, resulting in repair failure.
[0035] Based on this, the present invention provides a photomask repair process, including: providing a photomask, the photomask having a mask pattern and a defect, and a plurality of groups of anti-deflection points are arranged on the mask pattern, the number of anti-deflection points in each group is greater than one, and the material of the anti-deflection points includes chromium; using an electron beam repair device, repairing the defect based on the anti-deflection points to complete the repair of the defect, and the anti-deflection points are retained after the repair is completed. The present invention sets the number of anti-deflection points in each group and the material of the anti-deflection points, the number of anti-deflection points in each group is greater than one, and the material of the anti-deflection points includes chromium, so that the anti-deflection points will not be consumed due to long-term repair, and the electron beam repair device is used to repair the defect based on the anti-deflection points, and the anti-deflection points are retained after the repair is completed, which can effectively prevent the repair failure caused by long-term repair, thereby improving the accuracy of photomask repair.
[0036] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. The drawings are all in a very simplified form and are not drawn to scale, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In addition, the structure shown in the drawings is often part of the actual structure; in particular, the emphasis of each drawing is different, and sometimes different scales are used.
[0037] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.
[0038] In the description of the present application, it should be understood that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of the application is conventionally placed when in use, or are the orientations or positional relationships conventionally understood by those skilled in the art. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.
[0039] In addition, relational terms such as the terms "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such articles or equipment. In the absence of further restrictions, the elements defined by the statement "comprise one..." do not exclude the existence of other identical elements in the articles or equipment including the elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.
[0040] Figure 7 This is a flow chart of a photomask repair process provided in this embodiment. Please refer to Figure 7 , this embodiment provides a photomask repair process, including:
[0041] Step S1: providing a photomask, the photomask having a mask pattern and defects, and a plurality of groups of anti-deflection points are arranged on the mask pattern, the number of anti-deflection points in each group is greater than one, and the material of the anti-deflection points includes chromium;
[0042] Step S2: using electron beam repair equipment to repair the defect based on the anti-deflection point to complete the defect repair, and the anti-deflection point is retained after the repair is completed.
[0043] Figure 8 to Figure 10 A schematic diagram of a photomask in a photomask repair process provided in this embodiment, Fig.11 This is a partial imaging picture under an electron microscope in a photomask repair process provided in this embodiment. Fig.12 This is a partial imaging picture under an electron microscope after a defect is repaired in a photomask repair process provided in this embodiment. Figure 8 to Figure 12 A photomask repair process provided in this embodiment is described in detail.
[0044] Please refer to Figure 8 to Figure 10, perform step S1: provide a photomask 100, the photomask 100 is a COG photomask, the photomask 100 has a mask pattern 200 and a defect 300, the mask pattern 200 shown in the figure is in a strip shape, but is not limited to this shape; the defect 300 is a residue when the mask pattern 200 is prepared, and the material of the defect 300 is the same as that of the mask pattern 200, both of which are chromium. In this embodiment, at least one dimension of the defect 300 is greater than 2μm, and the defect 300 is defined as a large-size defect; the defect 300 may be rectangular, and specifically, two adjacent sides (length and width) of the defect 300 have a first dimension d1 and a second dimension d2, respectively, and the first dimension d1 and / or the second dimension d2 is greater than 2μm.
[0045] A plurality of groups of anti-bias points 400 are provided on the mask pattern 200 (each circular dotted frame in the figure shows a group of anti-bias points 400), and the number of each group of anti-bias points 400 is greater than one. In the present embodiment, the material of the anti-bias points 400 includes chromium, and the material of the anti-bias points 400 is set to chromium, which is harder and not easily consumed during long-term repair. In combination with the number and distribution rule of each group of anti-bias points 400, repair failures caused by long-term repair are effectively prevented, so that the repair accuracy of large-size defects is higher. In the present embodiment, the number of each group of anti-bias points 400 is greater than one and less than or equal to four.
[0046] Table 2 shows the distribution rules of anti-deflection points corresponding to defects of different sizes. Please refer to Table 2. The specific distribution rules are as follows: Figure 8 , the defect 300 is rectangular, when any dimension of the defect 300 (the first dimension d1 or the second dimension d2) is greater than 2μm and less than 4μm, the other dimensions of the defect 300 are 0μm to 2μm; or each dimension of the defect 300 (the first dimension d1 and the second dimension d2) is greater than 2μm and less than 4μm, the number of anti-bias points 400 in each group is 2, the two anti-bias points 400 are arranged left and right or up and down, the diameter of the anti-bias points 400 is 12nm, the distance between the two anti-bias points 400 is 0.02 times the maximum dimension of the defect 300, and the maximum dimension of the defect 300 is the larger of the first dimension d1 and the second dimension d2.
[0047] Combination Fig. 9 The defect 300 is rectangular, any dimension of the defect 300 (the first dimension d1 or the second dimension d2) is greater than 4μm, the other dimensions of the defect 300 are 0μm~2μm or 2μm~4μm, the number of anti-bias points 400 in each group is 3, the 3 anti-bias points 400 are arranged in a triangle, the diameter of the anti-bias points 400 is 10nm, the distance between two adjacent anti-bias points 400 is 0.015 times the maximum dimension of the defect 300, and the maximum dimension of the defect 300 is the larger of the first dimension d1 and the second dimension d2.
[0048] Combination Fig.10The defect 300 is rectangular, and each dimension of the defect 300 (the first dimension d1 and the second dimension d2) is greater than 4 μm. There are 4 anti-bias points 400 in each group, and the 4 anti-bias points 400 are arranged in an array. The diameter of the anti-bias points 400 is 7 nm. The distance between two adjacent anti-bias points 400 is 0.01 times the maximum dimension of the defect 300. Among the 4 anti-bias points 400, two adjacent anti-bias points 400 do not include the two diagonal anti-bias points 400. The maximum dimension of the defect 300 is the larger of the first dimension d1 and the second dimension d2.
[0049]
[0050] Table 2. Distribution rules of anti-deflection points corresponding to defects of different sizes
[0051] According to Table 1, it is known that by setting the distribution rule of the corresponding anti-deviation points 400 according to the size of the defect 300, the defect 300 can be effectively repaired, so that all large-sized defects 300 can be repaired.
[0052] In this embodiment, the diameter of the anti-deflection point 400 is 1nm to 15nm, and the anti-deflection point 400 is formed on the mask pattern 200 by a deposition process. During the formation of the anti-deflection point 400, the number of deposition cycles is 1 to 1000 times, the number of deposition halo suppression is 1 to 5 times, and the number of deposition halo suppression pixels is 1 pixel to 3000 pixels. During the formation of the anti-deflection point 400, the gas introduced includes hexahydroxychromium, so that the main material of the anti-deflection point 400 is chromium.
[0053] Execute step S2: Use electron beam repair equipment to repair the defect 300 based on the position of the anti-deflection point 400, which is equivalent to using the anti-deflection point 400 as a reference point. Only by finding the reference point can the defect 300 be repaired to complete the repair of the defect 300. Based on the material of the anti-deflection point 400, the number of the anti-deflection point 400 and the distribution of the anti-deflection point 400 in this embodiment, the anti-deflection point 400 is retained after the repair is completed, thereby realizing the repair of large-sized defects 300. In this embodiment, the defect 300 is repaired by an etching repair process to remove the defect 300.
[0054] Please refer to Fig.11 , which shows part of the mask pattern of the photomask. The circled position in the figure is a set of anti-deflection points, and the number of anti-deflection points is 4; please refer to Fig.12 The square in the figure is the repair area (equivalent to the defect), the size of the repair area is greater than 4μm, and the repair area is etched and repaired based on the anti-bias point. It can be seen from the figure that the repair window of the repair area (compared to Figure 6 The darker areas) have been completely etched, and all four anti-bias points are retained after the repair is completed.
[0055] In summary, the photomask repair process provided by the present invention includes: providing a photomask, the photomask having a mask pattern and a defect, and a plurality of groups of anti-deflection points are arranged on the mask pattern, the number of anti-deflection points in each group is greater than one, and the material of the anti-deflection points includes chromium; using an electron beam repair device, repairing the defects based on the anti-deflection points to complete the repair of the defects, and the anti-deflection points are retained after the repair is completed. The present invention sets the number of anti-deflection points in each group and the material of the anti-deflection points, the number of anti-deflection points in each group is greater than one, and the material of the anti-deflection points includes chromium, so that the anti-deflection points will not be consumed due to long-term repair, and the electron beam repair device is used to repair the defects based on the anti-deflection points, and the anti-deflection points are retained after the repair is completed, which can effectively prevent the repair failure caused by long-term repair, thereby improving the accuracy of photomask repair.
[0056] The above is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any technician in the relevant technical field, without departing from the scope of the technical solution of the present invention, makes any form of equivalent replacement or modification to the technical solution and technical content disclosed in the present invention, which does not depart from the content of the technical solution of the present invention and still falls within the protection scope of the present invention.
Claims
1. A photomask repair process, characterized in that: include: A photomask is provided, wherein the photomask has a mask pattern and defects, and the mask pattern is provided with a plurality of groups of anti-deflection points, the number of the anti-deflection points in each group is greater than one, and the material of the anti-deflection points includes chromium; The defect is repaired based on the anti-deflection point by using electron beam repair equipment to complete the repair of the defect, and the anti-deflection point is retained after the repair is completed.
2. The photomask repair process according to claim 1, characterized in that: At least one dimension of the defect is larger than 2 μm.
3. The photomask repair process according to claim 2, characterized in that: The defect is rectangular, and two adjacent sides of the defect have a first size and a second size respectively, and the first size and / or the second size is greater than 2 μm.
4. The photomask repair process according to claim 2, characterized in that: The number of the anti-deviation points in each group is greater than 1 and less than or equal to 4.
5. The photomask repair process according to claim 4, characterized in that: Any size of the defect is greater than 2μm and less than 4μm or each size of the defect is greater than 2μm and less than 4μm, the number of anti-bias points in each group is 2, the diameter of the anti-bias point is 12nm, and the distance between two anti-bias points is 0.02 times the maximum size of the defect.
6. The photomask repair process according to claim 4, characterized in that: Any size of the defect is greater than 4 μm, the number of the anti-deflection points in each group is 3, the diameter of the anti-deflection points is 10 nm, and the distance between two adjacent anti-deflection points is 0.015 times the maximum size of the defect.
7. The photomask repair process according to claim 4, characterized in that: Each dimension of the defect is greater than 4 μm, the number of the anti-deflection points in each group is 4, the diameter of the anti-deflection points is 7 nm, and the distance between two adjacent anti-deflection points is 0.01 times the maximum dimension of the defect.
8. The photomask repair process according to claim 1, characterized in that: The diameter of the anti-deflection point is 1nm to 15nm, and the anti-deflection point is formed on the mask pattern by a deposition process. During the formation of the anti-deflection point, the number of deposition cycles is 1 to 1000 times, the number of deposition halo suppression is 1 to 5 times, and the number of deposition halo suppression pixels is 1 pixel to 3000 pixels.
9. The photomask repair process according to claim 8, characterized in that: During the formation of the anti-deflection point, the introduced gas includes hexahydroxychromium.
10. The photomask repair process according to claim 1, characterized in that: The defects are repaired by using an etching repair process.
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