Photomask repairing method and photomask
By forming a broken defect area in a high-end photomask and repairing it, the problem of difficult and difficult deposition defects in high-difficulty small-area are solved, improving the repair success rate and passing rate, and reducing the rework steps.
Patent Information
- Application Number
- CN202311506800.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-11-13
- Publication Date
- 2025-05-23
AI Technical Summary
The prior art is difficult to effectively repair the high-difficulty small-area deposition defects in high-end photomasks, which makes it difficult to control the repair results and easily lead to the scrapping of the photomask.
By determining the area to be removed for the line to be repaired, the non-defect area forms a broken defect area, and then the broken defect area is repaired to make the line a standard line.
The success rate of high-end photomasks with high-difficulty small-area deposition defects is improved in one go, the rework step is reduced, the firm adhesion of the deposited substances is ensured, and the pass rate of the repaired photomask is improved.
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Figure CN120029003A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of semiconductor technology, and in particular to a photomask repair method and a photomask. Background Art
[0002] Please refer to Figure 1 , Figure 1 This is a flow chart of the traditional repair process for high-difficulty small-area deposition defects. For photomask products, if there are defects in the key graphic area that need to be repaired by deposition, the usual practice is to directly repair the defective area. The specific repair process is: find an identical graphic without defects, copy its graphic morphology, then go to the area that needs to be repaired to identify the defective graphic morphology, perform a difference operation on the two morphologies, and thus obtain a missing defective graphic relative to the normal graphic. Finally, this missing graphic is deposited according to the design requirements through a certain deposition process.
[0003] However, this conventional repair method is not suitable for high-end photomask defects. Because, as the high-end photomask process becomes smaller, the corresponding graphic line width is also smaller. When the line width is smaller, the size of the exposure defect also becomes smaller. When the defect is small but still needs to be repaired, the challenge for such small deposition defects becomes greater and greater. If such small deposition defects are not repaired, repetitive exposure defects will be formed; if repaired, in the subsequent cleaning process, due to the small area of deposition in the defective area, the deposited material is easily washed away, resulting in rework, and multiple rounds of rework will eventually cause the photomask to be scrapped. In order to prevent the deposited material from being washed away, it is usually adopted to increase the deposition area so that the deposited material is firmly adhered to the substrate surface. However, this method will increase the height of the normal area of the line, resulting in the difficulty of controlling the repair results of such defects. It is necessary to perform multiple rounds of rework and repair according to the actual repair experience of the operator, which is also easy to cause the photomask to be scrapped. Therefore, how to improve the success rate of one-time repair of high-difficulty small-area deposition defects of high-end photomasks is a technical problem that technicians in this field currently need to solve. Summary of the invention
[0004] The purpose of the present application is to provide a photomask repair method and a photomask, so as to improve the success rate of one-time repair of difficult small-area deposition defects of high-end photomasks.
[0005] To achieve the above object, the present application provides a photomask repair method, comprising:
[0006] Determine a first boundary and a second boundary of a region to be removed of a line to be repaired along a length direction of the line, so that the region to be removed includes a defective region and a non-defective region;
[0007] Removing the line in the non-defective area between the first boundary and the second boundary to form a broken line defective area;
[0008] The broken line defect area is repaired to make the line to be repaired become a standard line, thereby obtaining the repaired photomask.
[0009] Optionally, removing the line in the non-defective area between the first boundary and the second boundary to form a broken line defective area includes:
[0010] The line of the non-defective region between the first boundary and the second boundary is removed by etching to form the disconnection defect region.
[0011] Optionally, removing the line in the non-defective area between the first boundary and the second boundary by etching to form the disconnection defective area includes:
[0012] focusing an electron beam on the surface of the line so that the electron beam scans the surface of the line in the non-defective region between the first boundary and the second boundary;
[0013] According to preset etching process parameters, etching reaction gas is introduced into the reaction chamber, so that the etching reaction gas cooperates with the electron beam etching to remove the line in the non-defective area between the first boundary and the second boundary to form the broken line defect area.
[0014] Optionally, the etching reaction gas is xenon difluoride gas.
[0015] Optionally, the preset etching process parameters include the total number of etching cycles, the number of pre-etching cycles, the etching endpoint coefficient, the post-etching cycle unit and the endpoint unit etching cycle amount; the horizontal scanning amount, the vertical scanning amount, the scanning X offset and the scanning Y offset; the etching offset, the boundary etching offset, the non-boundary etching offset and the boundary neglect offset; the etching endpoint critical lower limit and the etching endpoint trigger slope; and the etching reaction gas temperature.
[0016] Optionally, the total number of etching cycles is 1 to 200,000, including the values at both ends; the number of pre-etching cycles is 0 to 200,000, including the values at both ends; the etching endpoint coefficient is 0 to 1, including the values at both ends; the post-etching cycle unit is 1 to 100, including the values at both ends; the endpoint unit etching cycle amount is 0 to 5000, including the values at both ends;
[0017] The horizontal scanning amount is 1 pixel to 100 pixels, including the values at both ends; the vertical scanning amount is 1 pixel to 100 pixels, including the values at both ends; the scanning X offset is -100 pixels to 100 pixels, including the values at both ends; the scanning Y offset is -100 pixels to 100 pixels, including the values at both ends;
[0018] The etching offset is -100 pixels to 100 pixels, including the values at both ends; the boundary etching offset is -100 pixels to 100 pixels, including the values at both ends; the non-boundary etching offset is -100 pixels to 100 pixels, including the values at both ends;
[0019] The boundary neglect offset is -100 pixels to 100 pixels, including the values at both ends;
[0020] The critical lower limit of the etching endpoint is 0 to 300 dB, including the values at both ends; the etching endpoint trigger slope is -1 to 1, including the values at both ends;
[0021] The etching reaction gas temperature is -60°C to 60°C, including both ends.
[0022] Optionally, the repairing of the broken line defect area so that the line to be repaired becomes a standard line to obtain the repaired photomask includes:
[0023] focusing an electron beam on the surface of the line so that the electron beam scans the surface of the broken line defect area;
[0024] According to the standard broken line deposition parameters, a deposition reaction gas is introduced into the reaction chamber, and the deposition reaction gas cooperates with the electron beam to repair the broken line defect area, so that the line to be repaired becomes the standard line, and the repaired photomask is obtained.
[0025] Optionally, after repairing the broken line defect area, the method further includes:
[0026] Confirm whether the repaired photomask is within the product specifications by using a spatial simulation measurement device; when it is detected that the repaired photomask is not within the product specifications, loop through the step of repairing the broken line defect area, until the step of confirming whether the repaired photomask is within the product specifications by using a spatial simulation measurement device, until it is detected that the repaired photomask is within the product specifications.
[0027] Optionally, the step of determining a first boundary and a second boundary of a region to be removed of a line to be repaired along a length direction of the line so that the region to be removed includes a defective region and a non-defective region comprises:
[0028] The first boundary and the second boundary of a to-be-removed area of the line to be repaired along the length direction of the line are determined so that the to-be-removed area includes all the defective areas and the non-defective areas; the line includes a plurality of the defective areas.
[0029] To achieve the above-mentioned purpose, the present application also provides a photomask, including: a photomask prepared by the above-mentioned photomask repair method.
[0030] The present application provides a photomask repair method, comprising: determining a first boundary and a second boundary of a region to be removed of a line to be repaired along the length direction of the line, so that the region to be removed includes a defective region and a non-defective region; removing the line in the non-defective region between the first boundary and the second boundary to form a broken line defective region; repairing the broken line defective region to make the line to be repaired a standard line, thereby obtaining the repaired photomask.
[0031] Obviously, the present application removes the entire line where the defective area is located to increase the area of the defective area and form a standard broken line type deposition defect; and then repairs the broken line type deposition defect. Since the controllability of the broken line type deposition defect repair process is higher than that of the small area deposition defect process, the new repair process of first forming a standard broken line type deposition defect and then depositing can greatly improve the one-time success rate of repairing such high-difficulty defects. This process step can be applied to specific deposition defects on photomasks of different layers, photomasks of different processes, and photomasks of different graphics, optimizes the photomask repair process flow, greatly reduces the rework process steps, and saves delivery time. The present application also provides a photomask, which can ensure that the deposited material is firmly adhered to the surface of the substrate after being repaired by the above-mentioned photomask repair method, and will not affect the height of the normal area of the line. The repaired photomask has a higher pass rate. BRIEF DESCRIPTION OF THE DRAWINGS
[0032] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.
[0033] Figure 1 This is a schematic diagram of the process of traditional repairing technology for high-difficulty small-area deposition defects;
[0034] Figure 2 A line diagram of a difficult small area deposition defect;
[0035] Figure 3 This is a schematic diagram of the lines after repair using the traditional repair process;
[0036] Figure 4 This is a schematic diagram of the lines after being repaired again using the traditional repair process.
[0037] Figure 5A flow chart of a photomask repair method provided in an embodiment of the present application;
[0038] Figure 6 A flowchart of another photomask repair method provided in an embodiment of the present application;
[0039] Figure 7 A schematic diagram of a process of a photomask repair method provided in an embodiment of the present application;
[0040] Figure 8 A line diagram of another type of high-difficulty small-area deposition defect;
[0041] Fig. 9 It is a schematic diagram of the lines after etching in the previous process;
[0042] Fig.10 This is a schematic diagram of the lines after repair by the repair process of this application. DETAILED DESCRIPTION
[0043] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction 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. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.
[0044] Please refer to Figure 2 , Figure 2 This is a schematic diagram of a line of a difficult small area deposition defect. The line width of some lines in the figure is too thin, which exceeds the standard of spatial simulation measurement. This type of defect meets the requirements of small line width challenging deposition defects and requires deposition repair.
[0045] Please refer to Figure 3 , Figure 3This is a schematic diagram of the lines after the traditional repair process. In the figure, only the defective area is deposited. However, since the defective area is too small, it is impossible to deposit only the defective area. It is necessary to deposit the normal graphic area together so that the deposited material can be firmly adhered to the surface of the substrate. The advantage of this process is that the deposited material will not be easily washed away by the subsequent cleaning process, but the disadvantage is that this repair process method will raise the terrain at the defect. The height of the line repaired by this process is higher than that of the ordinary graphic. Since the height of the defect after repair is inconsistent with the height of the ordinary graphic, the further disadvantage is that in the spatial simulation imaging link, even if the repair boundary is flush, it is difficult to enter the product specifications, because the spatial simulation imaging results brought by the different heights are different. Due to the disadvantage of this height difference, in actual repair, it is not possible to completely overlap and repair according to the boundary of the normal graphic. Usually, according to experience, the repair line width needs to be smaller than the normal line width. In this case, the repair result depends entirely on the actual repair experience of the operator, and the repair result of such defects will be difficult to control.
[0046] Please refer to Figure 4 , Figure 4 This is a schematic diagram of the lines after the traditional repair process and the second repair process. After the traditional repair process of the experienced repair personnel, this high-difficulty deposition defect still did not enter the defect specification of the space simulation imaging, so it was repaired again, and the repair process method was still the traditional deposition process method. The result of this repair was still not within the specification, and finally the product was scrapped.
[0047] Therefore, the present application provides a photomask repair method, which increases the area of the defective area by removing the entire line where the defective area is located, thereby forming a standard broken line type deposition defect; and then repairing the broken line type deposition defect, thereby improving the success rate of one-time repair of difficult small-area deposition defects of high-end photomasks.
[0048] Please refer to Figure 5 , Figure 5 A flowchart of a photomask repair method provided in an embodiment of the present application, the method may include:
[0049] S101: Determine a first boundary and a second boundary of a region to be removed of a line to be repaired along a length direction of the line, so that the region to be removed includes a defective region and a non-defective region.
[0050] This embodiment does not limit the specific method of determining the first boundary and the second boundary, as long as the defective area is contained in the area to be removed. For example, the first boundary and the second boundary of an area to be removed of a line to be repaired along the length direction of the line may be determined, so that the area to be removed includes all defective areas and non-defective areas; the line includes multiple defective areas; or the first boundary and the second boundary of each area to be removed of multiple areas to be removed of the line to be repaired along the length direction of the line may be determined, so that each area to be removed includes a defective area and a non-defective area; the line includes multiple defective areas.
[0051] S102: removing lines in the non-defective region between the first boundary and the second boundary to form a broken line defective region.
[0052] It should be noted that the missing portion of the line to be repaired is a defective area, and the retained portion is a non-defective area. In this embodiment, the retained line between the first boundary and the second boundary is removed, thereby forming a broken line defect between the first boundary and the second boundary.
[0053] This embodiment does not limit the specific method of removing the lines in the non-defective area between the first boundary and the second boundary, as long as it is ensured that a broken line defect area can be formed. For example, the lines in the non-defective area between the first boundary and the second boundary can be removed by etching to form a broken line defect area. Furthermore, this embodiment can remove the lines in the non-defective area between the first boundary and the second boundary by focusing the electron beam in conjunction with the etching reaction gas. The process is specifically as follows: focusing the electron beam on the surface of the line so that the electron beam scans the surface of the line in the non-defective area between the first boundary and the second boundary; according to the preset etching process parameters, the etching reaction gas is introduced into the reaction chamber so that the etching reaction gas cooperates with the electron beam to etch and remove the lines in the non-defective area between the first boundary and the second boundary to form a broken line defect area. It should be noted that this method is to etch away the area that needs to be etched by reacting the etching reaction gas with the area scanned by the electron beam.
[0054] Furthermore, in order to avoid affecting the subsequent repair process, after the disconnection defect area is formed in this embodiment, the residual etching reaction gas in the reaction chamber can be discharged from the reaction chamber through the exhaust pipe.
[0055] This embodiment does not limit the specific type of etching reaction gas, as long as the etching reaction gas can react with the photomask lines, for example, the etching reaction gas is xenon difluoride gas.
[0056] This example does not limit the specific types of preset etching process parameters, and the specific types of preset etching process parameters can be determined according to the actual situation of the defects. For example, the preset etching process parameters can include the total number of etching cycles, the number of pre-etching cycles, the etching endpoint coefficient, the post-etching cycle unit and the endpoint unit etching cycle amount; the horizontal scanning amount, the vertical scanning amount, the scanning X offset and the scanning Y offset; the etching offset, the boundary etching offset, the non-boundary etching offset and the boundary neglect offset; the etching endpoint critical lower limit and the etching endpoint trigger slope; and the etching reaction gas temperature.
[0057] This embodiment does not limit the specific value of the total number of etching cycles. For example, the total number of etching cycles can be 1 to 200,000, including both ends.
[0058] This embodiment does not limit the specific value of the pre-etching cycle number. For example, the pre-etching cycle number can be 0 to 200000, including the values at both ends. The pre-etching cycle number means that the pre-etching cycle will not trigger the secondary backscattered electron signal detector. The pre-etching cycle does not need to collect the secondary backscattered electron signal (the electron signal after the electron beam is focused on the line surface and reflected by the surface), so it will not trigger the etching end point. If this parameter is set too high, it will cause the etching end point to be missed. If it is set too low, the overall process time will be too long. It is necessary to set a suitable pre-etching cycle number.
[0059] This embodiment does not limit the specific value of the etching endpoint coefficient. For example, the etching endpoint coefficient can be 0 to 1, including the values at both ends. The etching endpoint coefficient is used in conjunction with the post-cycle. If it is set to 1, the actual number of post-cycle applications is 100% of the post-cycle number. If it is set to 0.5, the actual number of post-cycle applications is 50% of the post-cycle number.
[0060] This embodiment does not limit the specific value of the post-etching cycle unit. For example, the post-etching cycle unit can be 1 to 100, including the values at both ends. This embodiment does not limit the specific value of the endpoint unit etching cycle amount. For example, the endpoint unit etching cycle amount can be 0 to 5000, including the values at both ends. The post-etching cycle unit refers to the number of endpoint unit etching cycles. The endpoint unit etching cycle amount refers to the fixed number of etching cycles required after the etching endpoint is triggered. Usually, the endpoint does not control the boundary well, and a post-cycle is required to increase the number of etching cycles. Too small a post-etching cycle number may result in unclean etching, and too large a post-etching cycle number may result in over-etching. The product of the post-etching cycle unit and the endpoint unit etching cycle amount is the post-etching cycle number.
[0061] The present embodiment does not limit the specific value of the horizontal scanning amount. For example, the horizontal scanning amount can be 1 pixel to 100 pixels, including the values at both ends. The present embodiment does not limit the specific value of the vertical scanning amount. For example, the vertical scanning amount can be 1 pixel to 100 pixels, including the values at both ends. The horizontal scanning amount and the vertical scanning amount refer to the number of pixels scanned once in the X direction (i.e., the scanning area) and the number of pixels scanned once in the Y direction (i.e., the scanning area), respectively. Modifying these two parameters can modify the minimum scanning area of the electron beam.
[0062] This embodiment does not limit the specific value of the X offset, for example, the scan X offset can be -100 pixels to 100 pixels, including the values at both ends. This embodiment does not limit the specific value of the Y offset, for example, the scan Y offset can be -100 pixels to 100 pixels, including the values at both ends. The scan X offset and the scan Y offset refer to the displacement of one scan in the X direction and the displacement of one scan in the Y direction, respectively.
[0063] This embodiment does not limit the specific value of the etching offset. For example, the etching offset can be -100 pixels to 100 pixels, including the values at both ends. This embodiment does not limit the specific value of the boundary etching offset. For example, the boundary etching offset can be -100 pixels to 100 pixels, including the values at both ends. This embodiment does not limit the specific value of the non-boundary etching offset. For example, the non-boundary etching offset can be -100 pixels to 100 pixels, including the values at both ends. The etching offset refers to the overall etching area. The boundary etching offset refers to the etching offset between two materials. The non-boundary etching offset refers to the etching offset of one material.
[0064] This embodiment does not limit the specific value of the boundary neglect offset. For example, the boundary neglect offset can be -100 pixels to 100 pixels, including the values at both ends. The meaning of the boundary neglect offset is that since the boundary signal response of the pattern is relatively weak during etching, it often happens that the boundary has been etched, but the secondary backscattered electron signal shows that it is not completed. At this time, the boundary neglect offset is set to set the pixel range of the boundary neglect, so as to avoid the boundary being able to be etched all the time due to weak signal, thereby causing over-etching.
[0065] This embodiment does not limit the specific value of the critical lower limit of the etching endpoint. For example, the critical lower limit of the etching endpoint can be 0 to 300 dB, including the values at both ends. This embodiment does not limit the specific value of the etching endpoint trigger slope. For example, the etching endpoint trigger slope can be -1 to 1, including the values at both ends. The critical lower limit of the etching endpoint is used to control the opening time of the endpoint. If the secondary backscattered electron signal detector detects the secondary backscattered electron signal, and the signal intensity reaches the preset critical lower limit of the etching endpoint, the endpoint is opened. Setting the critical lower limit of the etching endpoint too early may cause an error in detecting the endpoint, and setting it too late may cause over-etching. The etching endpoint trigger slope is used to control the opening time of the endpoint. If the secondary backscattered electron signal detector detects the secondary backscattered electron signal, and the slope of the signal meets the preset slope, the endpoint is opened.
[0066] This embodiment does not limit the specific value of the etching reaction gas temperature. For example, the etching reaction gas temperature may be -60°C to 60°C, including both ends.
[0067] This embodiment does not limit the specific size of the above-mentioned single pixel, and the specific size of the single pixel can be determined according to actual conditions.
[0068] It should be noted that changes in the above parameters will affect the etching area and etching rate. Therefore, corresponding parameters can be selected for etching according to the actual situation of the defect.
[0069] S103: Repairing the broken line defect area to make the line to be repaired become a standard line, and obtaining a repaired photomask.
[0070] This embodiment does not limit the specific method of repairing the broken line defect area, as long as it can ensure that the line to be repaired can become a standard line. For example, the broken line defect area can be repaired by focusing the electron beam and depositing the reaction gas. The specific process is: focusing the electron beam on the surface of the line so that the electron beam scans the surface of the broken line defect area; according to the standard broken line deposition parameters, the deposition reaction gas is introduced into the reaction chamber, and the deposition reaction gas and the electron beam are used to repair the broken line defect area, so that the line to be repaired becomes a standard line, and a repaired photomask is obtained. .
[0071] Furthermore, in order to avoid affecting the subsequent repair process, after the line to be repaired becomes a standard line, the present embodiment can also discharge the residual deposition reaction gas in the reaction chamber out of the reaction chamber through the exhaust pipe.
[0072] The present embodiment does not limit the specific type of the deposition reaction gas, as long as it can ensure that the line to be repaired can become a standard line, for example, the deposition reaction gas is chromium hexacarbonyl gas.
[0073] This example does not limit the specific types of standard disconnection deposition parameters, and the specific types of standard disconnection deposition parameters can be determined according to the actual situation of the defect. For example, the standard disconnection deposition parameters may include the total number of deposition cycles, the number of pre-deposition cycles, the deposition endpoint coefficient, the post-deposition cycle unit and the endpoint unit deposition cycle amount; the horizontal scanning amount, the vertical scanning amount, the scanning X offset and the scanning Y offset; the deposition offset, the boundary deposition offset, the non-boundary deposition offset and the boundary neglect offset; the deposition endpoint critical lower limit and the deposition endpoint trigger slope; and the deposition reaction gas temperature.
[0074] This embodiment does not limit the specific value of the total number of deposition cycles. For example, the total number of deposition cycles may be 1 to 200,000, including both ends.
[0075] This embodiment does not limit the specific value of the number of pre-deposition cycles. For example, the number of pre-deposition cycles may be 0 to 200,000, including both ends.
[0076] This embodiment does not limit the specific value of the deposition endpoint coefficient. For example, the deposition endpoint coefficient may be 0 to 1, including both ends.
[0077] This embodiment does not limit the specific value of the post-deposition cycle unit, for example, the post-deposition cycle unit can be 1 to 100, including both ends. This embodiment does not limit the specific value of the endpoint unit deposition cycle amount, for example, the endpoint unit deposition cycle amount can be 0 to 5000, including both ends. The product of the post-deposition cycle unit and the endpoint unit deposition cycle amount is the post-deposition cycle number.
[0078] This embodiment does not limit the specific value of the horizontal scanning amount, for example, the horizontal scanning amount can be 1 pixel to 100 pixels, including the values at both ends. This embodiment does not limit the specific value of the vertical scanning amount, for example, the vertical scanning amount can be 1 pixel to 100 pixels, including the values at both ends.
[0079] This embodiment does not limit the specific value of the X offset, for example, the scanning X offset can be -100 pixels to 100 pixels, including the values at both ends. This embodiment does not limit the specific value of the Y offset, for example, the scanning Y offset can be -100 pixels to 100 pixels, including the values at both ends.
[0080] This embodiment does not limit the specific value of the deposition offset, for example, the deposition offset can be -100 pixels to 100 pixels, including the values at both ends. This embodiment does not limit the specific value of the boundary deposition offset, for example, the boundary deposition offset can be -100 pixels to 100 pixels, including the values at both ends. This embodiment does not limit the specific value of the non-boundary deposition offset, for example, the non-boundary deposition offset can be -100 pixels to 100 pixels, including the values at both ends.
[0081] This embodiment does not limit the specific value of the boundary neglect offset. For example, the boundary neglect offset may be -100 pixels to 100 pixels, including both ends.
[0082] This embodiment does not limit the specific value of the deposition endpoint critical lower limit, for example, the deposition endpoint critical lower limit can be 0 to 300 dB, including both ends. This embodiment does not limit the specific value of the deposition endpoint trigger slope, for example, the deposition endpoint trigger slope can be -1 to 1, including both ends.
[0083] The present embodiment does not limit a specific value of the deposition reaction gas temperature. For example, the deposition reaction gas temperature may be -60°C to 60°C, including both ends.
[0084] This embodiment does not limit the specific size of the above-mentioned single pixel, and the specific size of the single pixel can be determined according to actual conditions.
[0085] It should be noted that changes in the above parameters will affect the deposition area and deposition rate. Therefore, corresponding parameters can be selected for deposition processing according to the actual situation of the defect.
[0086] Furthermore, in order to improve the qualified rate of the repaired photomask, after repairing the broken line defect area, the present embodiment may also include: confirming whether the repaired photomask is within the product specifications through a spatial simulation measurement device; when it is detected that the repaired photomask is not within the product specifications, looping the step of repairing the broken line defect area, until the step of confirming whether the repaired photomask is within the product specifications through a spatial simulation measurement device is detected, until the repaired photomask is within the product specifications.
[0087] Based on the above embodiments, the present application removes the entire line where the defective area is located to increase the area of the defective area and form a standard broken line type deposition defect; and then repairs the broken line type deposition defect. Since the controllability of the broken line type deposition defect repair process is higher than that of the small area deposition defect process, the new repair process of first forming a standard broken line type deposition defect and then depositing can greatly improve the one-time success rate of repairing such high-difficulty defects. This process step can be applied to specific deposition defects on photomasks of different layers, photomasks of different processes, and photomasks of different graphics, which optimizes the photomask repair flow process, greatly reduces the rework process steps, and saves shipping time.
[0088] Please refer to Figure 6 , Figure 6 A flowchart of another photomask repair method provided in an embodiment of the present application, the method may include:
[0089] S201: Determine a first boundary and a second boundary of a region to be removed of a line to be repaired along a length direction of the line, so that the region to be removed includes a defective region and a non-defective region.
[0090] S202: focusing the electron beam on the surface of the line so that the electron beam scans the surface of the line in the non-defective area between the first boundary and the second boundary; introducing xenon difluoride gas into the reaction chamber according to preset etching process parameters, so that the xenon difluoride gas cooperates with the electron beam to etch and remove the line in the non-defective area between the first boundary and the second boundary, thereby forming a broken line defect area.
[0091] S203: focusing the electron beam on the surface of the line so that the electron beam scans the surface of the broken line defect area; according to the standard broken line deposition parameters, introducing hexacarbonyl chromium into the reaction chamber so that the hexacarbonyl chromium cooperates with the electron beam to repair the broken line defect area, so that the line to be repaired becomes a standard line, and a repaired photomask is obtained.
[0092] S204: confirm whether the repaired photomask is within the product specifications through a spatial simulation measurement device; when it is detected that the repaired photomask is not within the product specifications, loop through steps S203 to S204 until it is detected that the repaired photomask is within the product specifications.
[0093] Based on the above embodiments, the present application first etches all non-defective areas of the lines containing defective areas by focusing an electron beam in combination with xenon difluoride, so that the original deposition defects are expanded into standard broken line deposition defects, and then the deposition is performed using standard broken line deposition parameters, ultimately ensuring that the spatial simulation imaging results are within the product specifications. Since the controllability of the broken line deposition defect repair process is higher than that of the small area deposition defect process, the new repair process of etching first and then depositing can greatly improve the one-time success rate of repairing such difficult defects. This process step can be applied to specific deposition defects on photomasks of different layers, photomasks of different processes, and photomasks of different patterns, optimizing the photomask repair flow process, greatly reducing the rework process steps, and saving delivery time.
[0094] An embodiment of the present application further provides a photomask, which may include: a photomask prepared by the photomask repair method described above.
[0095] Based on the above embodiments, after the photomask is repaired by the above photomask repair method, the deposited material can be ensured to be firmly adhered to the substrate surface without affecting the height of the normal area of the line, and the qualified rate of the repaired photomask is higher.
[0096] The following is a specific example to illustrate the above photomask repair process. Please refer to Figure 7 , Figure 7 A schematic diagram of a photomask repair method provided in an embodiment of the present application is provided, and the process is specifically as follows:
[0097] 1. Defects in the photomask pattern are found;
[0098] 2. Measure the defect simulation results through the space simulation measurement equipment. When it is determined that the defect area is not within the product specifications, execute the subsequent repair process;
[0099] Please refer to Figure 8 , Figure 8 This is a schematic diagram of another type of high-difficulty small-area deposition defect. Some of the lines in the figure are too thin and need to be repaired by deposition.
[0100] 3. Perform etching pre-treatment in the repair equipment:
[0101] (1) The electron beam is first focused on the defect;
[0102] (2) Setting the etching pre-process parameters as shown in Table 1;
[0103] Table 1 Pre-etching process parameters
[0104]
[0105] (3) When etching begins, xenon difluoride gas is introduced into the reaction chamber to react with the area scanned by the electron beam. The xenon difluoride gas cooperates with the electron beam to etch away the area that needs to be etched; the lines after etching are as follows Fig. 9 As shown;
[0106] (4) The exhaust light will then discharge the residual gas in the reaction chamber to proceed to the next point repair or end the repair.
[0107] 4. Perform deposition repair in the repair equipment:
[0108] Through step 3, the deposition defects are etched into standard line-break type deposition defects, and then the deposition repair is performed by focusing the electron beam with chromium hexacarbonyl gas and setting the standard line-break deposition parameters shown in Table 2. The repaired lines are as follows Fig.10 shown.
[0109] Table 2 Standard disconnection deposition parameters
[0110]
[0111] 5. Use the spatial simulation measurement equipment to measure the defect simulation results to confirm whether the repair effect is within the product specifications; if it is not within the product specifications, return to step 4. Repeat steps 4 and 5 until it is detected that it is within the product specifications, and then perform final cleaning and shipment. The repeatability test results are shown in Table 3. Among them, the spatial simulation imaging results represent the contrast between the defect area and the same pattern without defects.
[0112] Table 3 Repeatability test results
[0113] Number of patches Spatial simulation imaging results (black area) 10 98％～102％
[0114] Compared with the traditional process, the repair process of this embodiment has an additional pre-etching process, which can greatly improve the one-time repair success rate of high-difficulty small-area deposition defects.
[0115] Specific examples are used herein to illustrate the principles and implementation methods of the present application, and the embodiments are in a progressive relationship, each embodiment focuses on the differences from other embodiments, and the same and similar parts between the embodiments can be referred to each other. The description of the above embodiments is only used to help understand the method and core ideas of the present application. For ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.
[0116] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used 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 "comprise", "include" 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 includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or equipment including the elements.
Claims
1. A photomask repair method, It is characterized in that include: Determine a first boundary and a second boundary of a region to be removed of a line to be repaired along a length direction of the line, so that the region to be removed includes a defective region and a non-defective region; Removing the line in the non-defective area between the first boundary and the second boundary to form a broken line defective area; The broken line defect area is repaired to make the line to be repaired become a standard line, thereby obtaining the repaired photomask.
2. The photomask repair method according to claim 1, It is characterized in that The removing the line in the non-defective area between the first boundary and the second boundary to form a broken line defective area includes: The line of the non-defective region between the first boundary and the second boundary is removed by etching to form the disconnection defect region.
3. The photomask repair method according to claim 2, It is characterized in that The method of removing the line in the non-defective area between the first boundary and the second boundary by etching to form the disconnection defective area includes: focusing an electron beam on the surface of the line so that the electron beam scans the surface of the line in the non-defective region between the first boundary and the second boundary; According to preset etching process parameters, etching reaction gas is introduced into the reaction chamber, so that the etching reaction gas cooperates with the electron beam etching to remove the line in the non-defective area between the first boundary and the second boundary to form the broken line defect area.
4. The photomask repair method according to claim 3, It is characterized in that The etching reaction gas is xenon difluoride gas.
5. The photomask repair method according to claim 3, It is characterized in that The preset etching process parameters include the total number of etching cycles, the number of pre-etching cycles, the etching endpoint coefficient, the post-etching cycle unit and the endpoint unit etching cycle amount; the horizontal scanning amount, the vertical scanning amount, the scanning X offset and the scanning Y offset; the etching offset, the boundary etching offset, the non-boundary etching offset and the boundary neglect offset; the etching endpoint critical lower limit and the etching endpoint trigger slope; and the etching reaction gas temperature.
6. The photomask repair method according to claim 5, It is characterized in that The total number of etching cycles is 1 to 200,000, including the values at both ends; the number of pre-etching cycles is 0 to 200,000, including the values at both ends; the etching endpoint coefficient is 0 to 1, including the values at both ends; the post-etching cycle unit is 1 to 100, including the values at both ends; the endpoint unit etching cycle amount is 0 to 5000, including the values at both ends; The horizontal scanning amount is 1 pixel to 100 pixels, including the values at both ends; the vertical scanning amount is 1 pixel to 100 pixels, including the values at both ends; the scanning X offset is -100 pixels to 100 pixels, including the values at both ends; the scanning Y offset is -100 pixels to 100 pixels, including the values at both ends; The etching offset is -100 pixels to 100 pixels, including the values at both ends; the boundary etching offset is -100 pixels to 100 pixels, including the values at both ends; the non-boundary etching offset is -100 pixels to 100 pixels, including the values at both ends; The boundary neglect offset is -100 pixels to 100 pixels, including the values at both ends; The critical lower limit of the etching endpoint is 0 to 300 dB, including the values at both ends; the etching endpoint trigger slope is -1 to 1, including the values at both ends; The etching reaction gas temperature is -60°C to 60°C, including both ends.
7. The photomask repair method according to claim 1, It is characterized in that The method of repairing the broken line defect area so that the line to be repaired becomes a standard line and obtaining the repaired photomask comprises: focusing an electron beam on the surface of the line so that the electron beam scans the surface of the broken line defect area; According to the standard broken line deposition parameters, a deposition reaction gas is introduced into the reaction chamber, and the deposition reaction gas cooperates with the electron beam to repair the broken line defect area, so that the line to be repaired becomes the standard line, and the repaired photomask is obtained.
8. The photomask repairing method according to claim 1, It is characterized in that After repairing the broken wire defect area, the method further includes: Confirm whether the repaired photomask is within the product specifications by using a spatial simulation measurement device; when it is detected that the repaired photomask is not within the product specifications, loop through the step of repairing the broken line defect area, until the step of confirming whether the repaired photomask is within the product specifications by using a spatial simulation measurement device, until it is detected that the repaired photomask is within the product specifications.
9. The photomask repair method according to claim 1, It is characterized in that The step of determining a first boundary and a second boundary of a region to be removed of a line to be repaired along a length direction of the line so that the region to be removed includes a defective region and a non-defective region comprises: The first boundary and the second boundary of a to-be-removed area of the line to be repaired along the length direction of the line are determined so that the to-be-removed area includes all the defective areas and the non-defective areas; the line includes a plurality of the defective areas.
10. A photomask, It is characterized in that include: A photomask prepared by the photomask repairing method according to any one of claims 1 to 9.
Citation Information
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