Photomask repairing method and device

Abstract

The invention relates to the field of photomask production, in particular to a photomask repairing method and device, and the method comprises the steps: scanning a to-be-processed photomask to obtain photomask image information; determining risk particle defects according to the photomask image information; determining an etching area corresponding to each risk particle defect according to a preset addressing rule; the etching region is located in the filling material pattern adjacent to the risk particle defect; etching the etching area to obtain an accommodating notch; scraping the risk particle defect into the accommodating notch by using a probe assembly; and repairing the accommodating notch to obtain the repaired photomask. According to the method, the accommodating notch is dug in the filling material near the risky particle defect, and the risky particle defect is transferred into the accommodating notch to be buried, so that the destructive violent impact on the risky particle defect is avoided, the controllability is high, the integrity of a filling material pattern can be well maintained, and the reliability of the filling material is improved. And the repairing efficiency and the finished product yield of the photomask are greatly improved.

Description

Technical Field

[0001] The present invention relates to the field of photomask production, and particularly to a photomask repair method and apparatus. Background Art

[0002] During the production of a photomask, many particulate defects usually appear on the mask substrate. These defects may be particles left during the previous process or foreign dust, etc. These defects will cover the patterns on the photomask that have been preliminarily patterned, thereby degrading the quality of the photomask. Therefore, it is necessary to remove the above-mentioned particulate defects through subsequent technical means.

[0003] As the photomask manufacturing process nodes continue to improve, the critical dimensions of the photomask continue to decrease, but the size of the particulate defects does not decrease with the improvement of the process. Therefore, on higher-end photomasks, the particulate defects are relatively larger with respect to the patterns of the photomask, and the boundaries of the particulate defects will be closer to the filling material pattern, and even coincide with the filling material pattern. Currently, particulate defects at the edges of the filling material patterns on photomasks are usually etched and repaired using an aggregated electron beam in combination with xenon difluoride (the etching repair refers to repairing the photomask, and the specific operation is to remove the particulate defects on the photomask). When etching and removing on the photomask, the closer the particulate defect is to the filling material pattern, the easier the edge of the filling material pattern is to be sputtered by the particle stream during the etching process, which makes the repair of the particulate defects often damage the normal pattern, greatly increasing the repair difficulty. Further, when the size of the particulate defect gradually approaches the size of the minimum line width, the repair of the hole-type particulate will definitely damage the normal pattern.

[0004] Therefore, how to develop a photomask repair method that does not damage the filling material pattern and has high efficiency at the same time is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of the present invention is to provide a photomask repair method and apparatus to solve the problems in the prior art that the repair efficiency of particulate defects near the filling material pattern in the photomask is low and the filling material pattern will be damaged.

[0006] To solve the above technical problems, the present invention provides a photomask repair method, including:

[0007] Scanning the photomask to be processed to obtain photomask image information;

[0008] Determining risk particulate defects according to the photomask image information;

[0009] Determining an etching area corresponding to each of the risk particulate defects according to a preset addressing rule; the etching area is located in the filling material pattern adjacent to the risk particulate defect;

[0010] Etch the etching region to obtain a receiving notch;

[0011] Use a probe assembly to scrape the risk particle defect into the receiving notch;

[0012] Repair the receiving notch to obtain a repaired photomask.

[0013] Optionally, in the photomask repair method, before etching the etching region to obtain a receiving notch, it further includes:

[0014] Judge whether the width of the etching region in the direction of the line connecting the risk particle defect and the midpoint of the etching region does not exceed a first multiple of the width of the filling material pattern where the etching region is located in the direction of the line after removing the etching region;

[0015] Correspondingly, etch the etching region to obtain a receiving notch;

[0016] When the width of the etching region in the direction of the line does not exceed a first multiple of the width of the filling material pattern where the etching region is located in the direction of the line after removing the etching region, etch the etching region to obtain a receiving notch.

[0017] Optionally, in the photomask repair method, the range of the first multiple is from 3 times to 4 times, including the endpoint values.

[0018] Optionally, in the photomask repair method, determining the etching regions corresponding to the respective risk particle defects according to a preset addressing rule includes:

[0019] Determine the candidate filling material patterns closest to the risk particle defect in each reference direction according to a preset reference direction;

[0020] Determine the width of each candidate filling material pattern in the corresponding reference direction;

[0021] Determine the candidate filling material pattern with the largest width in the corresponding reference direction as the filling material pattern to be etched;

[0022] Determine the etching region corresponding to the risk particle defect on the filling material pattern to be etched.

[0023] Optionally, in the photomask repair method, repairing the receiving notch includes:

[0024] Deposit on the receiving notch to fill the risk particle defect.

[0025] Optionally, in the optical mask repair method described above, the depositing on the receiving notch includes:

[0026] Depositing on the receiving notch with the same material as the filling material pattern.

[0027] Optionally, in the optical mask repair method described above, the etching the etching area to obtain a receiving notch includes:

[0028] Etching the etching area to completely remove the filling material pattern within the etching area, thereby obtaining a receiving notch.

[0029] Optionally, in the optical mask repair method described above, the using a probe assembly to scrape the risk particle defect into the receiving notch includes:

[0030] Using the probe assembly to scrape in the same direction all the time to scrape the risk particle defect into the receiving notch.

[0031] Optionally, in the optical mask repair method described above, the size of the receiving notch is at least 20% larger than the size of the corresponding risk particle defect.

[0032] An optical mask repair device for performing the steps of any one of the above optical mask repair methods.

[0033] The optical mask repair method provided by the present invention includes: scanning a to-be-processed optical mask to obtain optical mask image information; determining risk particle defects according to the optical mask image information; determining etching areas corresponding to the respective risk particle defects according to a preset addressing rule; the etching areas are located in the filling material patterns adjacent to the risk particle defects; etching the etching areas to obtain receiving notches; using a probe assembly to scrape the risk particle defects into the receiving notches; repairing the receiving notches to obtain a repaired optical mask. The present invention digs out receiving notches on the filling material near the risk particle defects and transfers the risk particle defects to the receiving notches for landfill, avoiding destructive violent impacts on the risk particle defects, having strong controllability, being able to well maintain the integrity of the filling material patterns on the optical mask, and greatly improving the repair efficiency and finished product yield of the optical mask. The present invention also provides an optical mask repair device having the above beneficial effects. Description of the Drawings

[0034] To more clearly illustrate the technical solutions of the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0035] Figure 1 It is a schematic flowchart of a specific implementation manner of the photomask repair method provided by the present invention;

[0036] Figures 2(a) and 2(b) are microscopic scanning diagrams of risk particle defects of the photomask repair method provided by the present invention;

[0037] Figure 3 It is a schematic flowchart of another specific implementation manner of the photomask repair method provided by the present invention;

[0038] Figure 4 It is a process structure diagram of a specific implementation manner of the photomask repair method provided by the present invention;

[0039] Figure 5 It is a schematic flowchart of yet another specific implementation manner of the photomask repair method provided by the present invention.

[0040] In the figure, it includes 01 - risk particle defect, 02 - etching area, and 03 - filling material pattern. Specific implementation manner

[0041] In order to enable those skilled in the art to better understand the solution of the present invention, the following will further elaborate on the present invention in conjunction with the drawings and specific implementation manners. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0042] The core of the present invention is to provide a photomask repair method, and a schematic flowchart of a specific implementation manner thereof is as Figure 1 shown, which is called specific implementation manner one, and includes:

[0043] S101: Scan the photomask to be processed to obtain photomask image information.

[0044] The photomask image information is also the surface image of the photomask to be processed, and contains the position information of the particle defect.

[0045] S102: Determine the risk particle defect according to the photomask image information.

[0046] The risk particle defect refers to a particle defect adjacent to or close to the filling material pattern. As shown in Fig. 2(a), the particle defect in Fig. 2(a) coincides with the edge of the filling material pattern, and even overlaps with the filling material pattern, as shown in Fig. 2(b).

[0047] S103: Determine the etching area corresponding to each of the risk particle defects according to a preset addressing rule; the etching area is located in the filling material pattern adjacent to the risk particle defect.

[0048] Search for the etching area near the risk particle defect. The etching area is located in the filling material pattern adjacent to the risk particle defect, that is, there is no obstacle for the risk particle defect to reach the etching area.

[0049] The structure of the photomask is to set an opaque filling material pattern on a transparent substrate, thereby forming various light-transmitting shapes to achieve the function of the mask.

[0050] S104: Etch the etching area to obtain a receiving notch.

[0051] The etching area should completely overlap with the receiving notch. In addition, the receiving notch faces the risk particle defect.

[0052] S105: Use a probe assembly to scrape the risk particle defect into the receiving notch.

[0053] The probe assembly can be a probe-type repair device or other devices. In this step, use the probe assembly to nudge the risk particle defect one by one, scrape, or push the risk particle defect into the receiving notch.

[0054] S106: Repair the receiving notch to obtain a repaired photomask.

[0055] The repair in this step refers to the restoration of the filling material pattern where the receiving notch is located, resetting the lost part of the filling material pattern in the previous step to make the filling material pattern restore to a preset shape.

[0056] As a preferred embodiment, the repairing of the receiving notch includes:

[0057] Deposit on the receiving notch to fill the risk particle defect.

[0058] In this preferred embodiment, use a deposition technique to fill the risk particle defect that has entered the receiving notch. The deposition has high uniformity, is easy to operate, and has low cost. Of course, other methods can also be used to repair the receiving notch, and the present invention does not limit this here.

[0059] In addition, depositing on the receiving notch includes:

[0060] Depositing on the receiving notch with the same material as the filling material pattern.

[0061] In this preferred embodiment, it is further defined that the material used to fill the receiving notch is the same as the original material of the filling material pattern, which improves the structural strength of the filling material pattern after repair and the conformal ability with the pattern, that is, improves the working stability of the photomask.

[0062] In addition, etching the etching area to obtain a receiving notch includes:

[0063] Etching the etching area to completely remove the filling material pattern in the etching area to obtain a receiving notch.

[0064] In this preferred embodiment, the opening condition of the receiving notch is further defined. It is defined that the filling material pattern in the etching area is completely etched. After the filling material pattern in the etching area is completely etched away, the bottom surface inside the obtained receiving notch exposes the transparent substrate of the photomask, so that the risk particle defects directly located on the transparent substrate can roll into the receiving notch without height difference, and it is easier to scrape the risk particle defects subsequently, improving the repair success rate, and ultimately improving the repair efficiency and repair success rate.

[0065] Furthermore, using the probe assembly to scrape the risk particle defect into the receiving notch includes:

[0066] Using the probe assembly to scrape in the same direction all the time to scrape the risk particle defect into the receiving notch.

[0067] In this preferred embodiment, it is defined that the probe assembly always scrapes the risk particle defect in only one direction, which can avoid damage to the filling material pattern caused by the probe assembly accidentally scraping in a direction outside the design, and improve the yield of the finished product.

[0068] As a specific embodiment, the size of the receiving notch is at least 20% larger than the size of the corresponding risk particle defect.

[0069] If the risk particle defect is approximately circular with a diameter of 20 nanometers, the size of the corresponding receiving notch should be at least 24 nanometers. Of course, the receiving notch is preferably rectangular, and the rectangular notch can greatly reduce the production difficulty. Designing the receiving notch to be slightly larger than the risk particle defect can provide a greater tolerance space for the transfer of the risk particle defect, improving the yield rate and repair efficiency. The above parameter range is the preferred range after a large number of theoretical calculations and actual tests. Of course, it can also be adjusted according to the actual situation, and the present invention does not limit it here.

[0070] The photomask repair method provided by the present invention includes: scanning a photomask to be processed to obtain photomask image information; determining risk particle defects according to the photomask image information; determining an etching area corresponding to each risk particle defect according to a preset addressing rule; the etching area is located in a filling material pattern adjacent to the risk particle defect; etching the etching area to obtain a receiving notch; using a probe assembly to scrape the risk particle defect into the receiving notch; and repairing the receiving notch to obtain a repaired photomask. The present invention digs a receiving notch in the filling material near the risk particle defect and transfers the risk particle defect to the receiving notch for landfill, avoiding the destructive violent impact on the risk particle defect, having strong controllability, being able to well maintain the integrity of the filling material pattern on the photomask, and greatly improving the repair efficiency and finished product yield rate of the photomask.

[0071] On the basis of the specific implementation manner 1, the determination method of the position of the receiving notch is further limited to obtain the specific implementation manner 2, and the corresponding process schematic diagram is as Figure 3 shown, including:

[0072] S201: Scan the photomask to be processed to obtain photomask image information.

[0073] S202: Determine risk particle defects according to the photomask image information.

[0074] S203: Determine an etching area corresponding to each risk particle defect according to a preset addressing rule; the etching area is located in a filling material pattern adjacent to the risk particle defect.

[0075] S204: Judge whether the width of the etching area in the direction of the line connecting the midpoint of the risk particle defect and the etching area does not exceed the first multiple of the width of the filling material pattern where the etching area is located after removing the etching area in the direction of the line.

[0076] Reference can be made to Figure 4 , Figure 4The connection line between the risk particle defect and the midpoint of the etching area is represented by a dotted line in the figure. In the figure, 01 represents the risk particle defect, 02 represents the etching area (which is the same as the subsequent receiving notch in position and size), 03 represents the filling material pattern, A represents the width of the etching area in the direction of the connection line between the risk particle defect and the midpoint of the etching area, and B represents the width of the filling material pattern where the etching area is located after removing the etching area in the connection line direction.

[0077] S205: When the width of the etching area in the connection line direction does not exceed the first multiple of the width of the filling material pattern where the etching area is located after removing the etching area in the connection line direction, etch the etching area to obtain a receiving notch.

[0078] S206: Use the probe assembly to scrape the risk particle defect into the receiving notch.

[0079] S207: Repair the receiving notch to obtain a repaired photomask.

[0080] The difference between this specific embodiment and the above specific embodiment is that a step of verifying whether the etching area can be etched is added in this specific embodiment, and the remaining steps are the same as those in the above specific embodiment, and will not be elaborated here.

[0081] In this preferred embodiment, the etching area is verified. Specifically, since the technical solution provided by the present invention requires opening a notch in the filling material pattern, it is necessary to ensure that the filling material pattern remains intact and structurally reliable after opening the notch. In terms of parameters, it means that the remaining filling material pattern after opening the receiving notch cannot become too thin and cause its own structure to be unstable. Therefore, in this specific embodiment, after determining the etching area according to the addressing rule, it is first confirmed whether the width of the remaining part of the material filling pattern after removing the etching area is sufficient. In other words, whether the remaining part meets the proportional relationship with the etching area. If the size of the etching area does not exceed the first multiple of the width of the remaining part, it means that the remaining part of the filling material pattern can still maintain a complete structure, greatly improving the product yield.

[0082] Specifically, the range of the first multiple is from 3 times to 4 times, including the end values, such as any one of 3.0 times, 3.5 times or 4.0 times. The above range is obtained through a large number of theoretical calculations and actual tests. Of course, it can also be adjusted according to the actual situation, and the present invention does not make any limitations here.

[0083] On the basis of specific embodiment one, the addressing rule is further limited to obtain specific embodiment three, and its corresponding process schematic diagram is asFigure 5 As shown in the figure, it includes:

[0084] S301: Scan the photomask to be processed to obtain photomask image information.

[0085] S302: Determine risk particle defects according to the photomask image information.

[0086] S303: Determine the candidate filling material patterns closest to the risk particle defects in each of the preset reference directions.

[0087] The reference direction can be selected according to actual needs. For example, a rectangular coordinate system is established in the photomask image information, and the reference directions are the positive and negative directions of the x-axis and y-axis, a total of 4 directions. Of course, other reference directions can also be selected according to actual situations, and the present invention does not make specific limitations here.

[0088] S304: Determine the widths of the candidate filling material patterns in the corresponding reference directions.

[0089] The candidate filling material pattern is the first filling material pattern encountered by the risk particle defect in the corresponding reference direction. Therefore, the reference direction should correspond one by one to the candidate filling material pattern. The width in this step is also the intercept of the candidate filling material pattern in the corresponding reference direction.

[0090] S305: Determine the candidate filling material pattern with the largest width in the corresponding reference direction as the filling material pattern to be etched.

[0091] S306: Determine the etching area corresponding to the risk particle defect on the filling material pattern to be etched.

[0092] S307: Etch the etching area to obtain a receiving notch.

[0093] S308: Use the probe assembly to scrape the risk particle defect into the receiving notch.

[0094] S309: Repair the receiving notch to obtain a repaired photomask.

[0095] The difference between this specific embodiment and the above specific embodiment is that an addressing rule is given in this specific embodiment, and the remaining steps are the same as those in the above specific embodiment, and will not be elaborated here.

[0096] In this preferred embodiment, the candidate filling material pattern with the maximum width in the reference direction is selected as the filling material pattern to be etched, and the etching area is set in the filling material pattern to be etched, ensuring that after the accommodation notch is opened, the remaining width of the filling material pattern to be etched is the largest and least likely to break or be damaged, further improving the finished product yield. Of course, the second specific embodiment and the third specific embodiment of the present invention can be combined and applied, and the present invention will not be elaborated herein.

[0097] The present invention also provides a photomask repair device, which is used to perform the steps of any one of the above-mentioned photomask repair methods. The photomask repair method provided by the present invention includes: scanning a photomask to be processed to obtain photomask image information; determining risk particle defects according to the photomask image information; determining an etching area corresponding to each of the risk particle defects according to a preset addressing rule, where the etching area is located in a filling material pattern adjacent to the risk particle defect; etching the etching area to obtain an accommodation notch; using a probe assembly to scrape the risk particle defect into the accommodation notch; and repairing the accommodation notch to obtain a repaired photomask. The present invention digs an accommodation notch in the filling material near the risk particle defect and transfers the risk particle defect to the accommodation notch for landfill, avoiding a destructive violent impact on the risk particle defect, having strong controllability, being able to well maintain the integrity of the filling material pattern on the photomask, and greatly improving the repair efficiency and finished product yield of the photomask.

[0098] In this specification, each embodiment is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. The same or similar parts among the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the method part.

[0099] It should be noted that in this specification, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variation thereof is intended to cover a non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "including a..." does not exclude the existence of additional identical elements in the process, method, article or device including the element.

[0100] The above has introduced in detail the photomask repair method and device provided by the present invention. Specific examples are used herein to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can still be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A method for repairing a photomask, characterized in that, Including: Scanning the photomask to be processed to obtain photomask image information; Determining risk particle defects according to the photomask image information; Determining an etching area corresponding to each of the risk particle defects according to a preset addressing rule; The etching area is located in the filling material pattern adjacent to the risk particle defect; Etching the etching area to obtain a receiving notch; Using a probe assembly to scrape the risk particle defect into the receiving notch; Repairing the receiving notch to obtain a repaired photomask.

2. The method for repairing a photomask according to claim 1, characterized in that, Before etching the etching area to obtain a receiving notch, it further includes: Judging whether the width of the etching area in the direction of the line connecting the risk particle defect and the midpoint of the etching area does not exceed a first multiple of the width of the filling material pattern where the etching area is located in the direction of the line after removing the etching area; Correspondingly, etching the etching area to obtain a receiving notch; When the width of the etching area in the direction of the line does not exceed the first multiple of the width of the filling material pattern where the etching area is located in the direction of the line after removing the etching area, etching the etching area to obtain a receiving notch.

3. The method for repairing a photomask according to claim 2, characterized in that, The range of the first multiple is from 3 times to 4 times, including the end values.

4. The method for repairing a photomask according to claim 1, characterized in that, The determining an etching area corresponding to each of the risk particle defects according to a preset addressing rule includes: Determining the filling material pattern to be selected closest to the risk particle defect in each reference direction according to a preset reference direction; Determining the width of each of the filling material patterns to be selected in the corresponding reference direction; Determining the filling material pattern to be etched with the largest width in the corresponding reference direction as the filling material pattern to be etched; Determining the etching area corresponding to the risk particle defect on the filling material pattern to be etched.

5. The method for repairing a photomask according to claim 1, characterized in that, The repairing the receiving notch includes: Depositing on the receiving notch to bury the risk particle defect.

6. The method for repairing a photomask according to claim 5, characterized in that, The depositing on the receiving notch includes: Depositing on the receiving notch with the same material as the filling material pattern.

7. The method for repairing a photomask according to claim 1, characterized in that, The etching the etching area to obtain a receiving notch includes: Etching the etching area to completely remove the filling material pattern in the etching area to obtain a receiving notch.

8. The method for repairing a photomask according to claim 1, characterized in that, The using a probe assembly to scrape the risk particle defect into the receiving notch includes: Using the probe assembly to scrape in the same direction all the time to scrape the risk particle defect into the receiving notch.

9. The method for repairing a photomask according to claim 1, characterized in that, The size of the receiving notch is at least 20% larger than the size of the corresponding risk particle defect.

10. A photomask repair device, characterized in that, The photomask repair device is used to execute the steps of the photomask repair method according to any one of claims 1 to 9.

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