Photomask repairing method and photomask

Abstract

The invention discloses a photomask repairing method and a photomask, and belongs to the technical field of semiconductors, and the method comprises the steps: determining a to-be-repaired region of the surface, deviating from a protective film, of the photomask; the to-be-repaired area corresponds to a defect area of a shading layer in the photomask; and a shading film is deposited in the to-be-repaired area to shield light which enters the defect area of the shading layer from the surface of the protective film and then penetrates through the transparent substrate, and the repaired photomask is obtained. According to the invention, the light shielding film is directly deposited on the back surface of the photomask to shield the light which is emitted from the defect area and then penetrates through the transparent substrate, so that the photomask after film pasting can be repaired under the condition that the protective film is not detached when a large black area hole defect occurs. The process steps can be suitable for specific defects on different layers of photomasks, photomasks of different manufacture procedures and photomasks of different patterns, the photomask flow repairing process flow is optimized, the reworking process steps are greatly reduced, the shipment time is saved, and the consumption of a protective film is reduced.

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] The hole-type defects of the chromium layer photomask are usually repaired by deposition gas combined with laser, focused ions or focused electrons on the photomask. This method is often used for hole defects of photomasks without protective films. As for the photomask with a protective film, if a hole-type defect occurs, since the deposition gas cannot penetrate the protective film and is deposited on the surface of the photomask pattern, such defects usually cannot be repaired directly. At present, there is no mature non-mold removal repair technical solution to support such defects in the photomask production process. It is usually necessary to remove the protective film, clean and remove the glue, and then repair it, and then re-apply a protective film. This repair method involves multiple process steps, and the process time is long. The more process steps are passed, the higher the risk of scrapping and delayed shipment, and at least one photomask protective film must be consumed. Moreover, with the improvement of the process, the price of the protective film will become more and more expensive. Therefore, how to reduce the multi-process time caused by the repair of hole-type defects and reduce the consumption of protective films are technical problems that technicians in this field currently need to solve. Summary of the invention

[0003] The purpose of the present application is to provide a photomask repair method and a photomask, thereby reducing the time required for multiple processes due to hole-type defect repair and reducing the consumption of protective films.

[0004] To achieve the above object, the present application provides a photomask repair method, comprising:

[0005] Determine a region to be repaired on the surface of the photomask away from the protective film; the region to be repaired corresponds to a defective region of the light shielding layer inside the photomask;

[0006] A light shielding film is deposited on the area to be repaired to shield the light that enters the defective area of ​​the light shielding layer from the surface of the protective film and then penetrates the transparent substrate, thereby obtaining the repaired photomask.

[0007] Optionally, depositing a light shielding film on the area to be repaired includes:

[0008] Depositing a light-shielding film on the area to be repaired by using a laser beam in combination with a reaction gas;

[0009] Accordingly, before determining the area to be repaired on the surface of the photomask away from the protective film, the method further includes:

[0010] The photomask is transferred into the cavity of the laser repairing device with the surface facing away from the protective film facing upward.

[0011] Optionally, determining the area to be repaired on the surface of the photomask away from the protective film includes:

[0012] Roughly positioning the to-be-repaired area of ​​the photomask that is away from the protective film;

[0013] Accurately positioning the area to be repaired to determine the coordinates of the area to be repaired;

[0014] By operating the stage of the laser repairing device, the lens position is moved from the rough positioning position to the coordinates of the area to be repaired.

[0015] Optionally, accurately positioning the area to be repaired to determine the coordinates of the area to be repaired includes:

[0016] Obtaining the front coordinates of the defect area using a defect inspection device; the front coordinates are the coordinates of the defect area on the surface of the protective film;

[0017] The front coordinates are converted to obtain the back coordinates of the defective area; the back coordinates are the coordinates of the defective area on the surface of the photomask away from the protective film;

[0018] The coordinates of the area to be repaired are determined according to the back surface coordinates.

[0019] Optionally, after depositing the light shielding film on the area to be repaired, the method further comprises:

[0020] Confirm whether the repaired photomask is within the product specifications through spatial simulation imaging; when it is detected that the repaired photomask is not within the product specifications, loop the step of depositing a light-shielding film in the area to be repaired, until confirming whether the repaired photomask is within the product specifications through spatial simulation imaging, until it is detected that the repaired photomask is within the product specifications.

[0021] Optionally, the reaction gas is chromium hexacarbonyl gas.

[0022] Optionally, the pulse number of the laser beam is 1 to 2 times, including the values ​​at both ends; the pulse overlap coefficient of the laser beam is 0.5 to 1, including the values ​​at both ends; the laser energy of the laser beam is 20% to 100%, including the values ​​at both ends; the attenuation factor of the laser beam is 10 to 60, including the values ​​at both ends; the deposited laser energy of the laser beam is 1% to 100%, including the values ​​at both ends.

[0023] Optionally, the deposition time is 1 ms to 500 ms, including both ends; the deposition step is 0.01 μm 2 / s~1μm 2 / s, including the values ​​at both ends.

[0024] Optionally, the flow rate of the reaction gas is 100 ml / min to 20000 ml / min, including the values ​​at both ends.

[0025] To achieve the above-mentioned objectives, the present application also provides a photomask, comprising: a transparent substrate, a light-shielding layer, a protective film metal frame and a protective film; the light-shielding layer and the protective film metal frame are arranged on the surface of the transparent substrate; the protective film metal frame surrounds the light-shielding layer; the protective film is arranged on the surface of the protective film metal frame away from the transparent substrate to cover the light-shielding layer; the surface of the transparent substrate away from the protective film is provided with a light-shielding film prepared by the above-mentioned photomask repair method.

[0026] The present application provides a photomask repair method, comprising: determining a to-be-repaired area on the surface of the photomask that is away from the protective film; the to-be-repaired area corresponds to a defective area of ​​a light-shielding layer inside the photomask; depositing a light-shielding film on the to-be-repaired area to block light that is incident from the surface of the protective film into the defective area of ​​the light-shielding layer and then penetrates a transparent substrate, thereby obtaining the repaired photomask.

[0027] Obviously, the present application deposits a light-shielding film directly on the back of the photomask to block the light that penetrates the transparent substrate after entering the defective area of ​​the light-shielding layer from the surface of the protective film. When a large black area hole defect appears on the photomask after the film is attached, it can be repaired without removing the protective film. This process step can be applied to specific defects on photomasks with different layers, photomasks with different processes, and photomasks with different graphics, optimizes the photomask repair process flow, greatly reduces the rework process steps, saves shipping time, and saves protective film consumption. The present application also provides a photomask, on the back of which a light-shielding film is deposited, which can block the light that penetrates the transparent substrate 1 after entering the defective area of ​​the light-shielding layer from the surface of the protective film. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] 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.

[0029] Figure 1 This is a full picture of the defect inspection of the photomask;

[0030] Figure 2 This is an enlarged view of the defect area;

[0031] Figure 3 is a schematic diagram of the photomask structure after film lamination;

[0032] Figure 4 A schematic diagram of the structure of a hole defect growing on the photomask after film lamination;

[0033] Figure 5 This is an old process flow chart for repairing hole defects in photomasks after film lamination;

[0034] Figure 6 A flow chart of a photomask repair method provided in an embodiment of the present application;

[0035] Figure 7 A flowchart of another photomask repair method provided in an embodiment of the present application;

[0036] Figure 8 A schematic diagram of the structure of a photomask provided in an embodiment of the present application;

[0037] Fig. 9 A schematic diagram of a process of a photomask repair method provided in an embodiment of the present application;

[0038] Fig.10 A schematic diagram of backside repair provided in an embodiment of the present application;

[0039] Fig.11 Provides spatial simulation imaging results of hole-type defect repair for the embodiments of the present application.

[0040] The following are the descriptions of the reference numerals:

[0041] 1-transparent substrate / quartz layer substrate; 2-light shielding layer; 2.1-patterned chromium layer; 2.2-patterned chromium oxide layer; 3-protective film metal frame; 4-protective film; 5-defective area; 6-light shielding film; 7-laser beam; 8-reaction gas / chromium hexacarbonyl gas. DETAILED DESCRIPTION

[0042] 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.

[0043] Please refer to Figure 1 , Figure 1 This is a general picture of the defect inspection of the photomask. Figure 1 The middle arrow indicates the hole defect position of the photomask after filming on the defect inspection equipment. It can be seen that there is a defect in the light shielding layer area of ​​the photomask at this position. Figure 2 As shown. Figure 2 It can be seen that there is an abnormal white spot area on the light shielding layer area, and there is a hole defect at this location. By checking the penetrating light, it can be determined whether the penetration rate of the defect is too high. When the penetration rate is too high, it may cause repetitive defects on the silicon wafer, so deposition repair is required at the defect location.

[0044] Normal photomask such as Figure 3 As shown, the photomask comprises a quartz substrate 1, a patterned chromium layer 2.1 and a protective film metal frame 3 arranged on the quartz substrate 1, a patterned chromium oxide layer 2.2 arranged on the patterned chromium layer 2.1, and a protective film 4 arranged on the protective film metal frame 3. However, in the process of preparing the photomask, it is inevitable that the photomask will have the following problems: Figure 4 The defect area 5 shown in the figure. In order to avoid affecting the subsequent use of the photomask, a deposition repair process is required to repair the defect. Common repair processes include Figure 5 As shown, the protective film 4 needs to be removed first, and the degumming and cleaning are performed; then the defect inspection and repair are performed; after the repair is completed, the protective film 4 is re-applied. This repair method involves multiple process steps, and the process time is long. The more process steps are passed, the higher the risk of scrapping and delayed shipment, and at least one photomask protective film 4 must be consumed. Moreover, with the improvement of the process, the price of the protective film 4 will become more and more expensive. Therefore, the present application provides a photomask repair method, by directly depositing a layer of light-shielding film 6 on the back of the photomask to block the light that enters from the surface of the protective film 4 and penetrates the defective area 5, thereby reducing the multi-process time caused by the repair of hole-type defects and reducing the consumption of the protective film 4.

[0045] Please refer to Figure 6 , Figure 6 A flowchart of a photomask repair method provided in an embodiment of the present application, the method may include:

[0046] S101: Determine a region to be repaired on the surface of the photomask facing away from the protective film 4; the region to be repaired corresponds to a defective region 5 of the light shielding layer 2 inside the photomask.

[0047] The present embodiment does not limit the specific method of determining the area to be repaired, as long as the position of the area to be repaired can be determined. For example, when the present embodiment uses a laser repair device to deposit the shading film 6, the method of determining the area to be repaired can be to roughly locate the area to be repaired on the surface of the photomask away from the protective film 4; to precisely locate the area to be repaired and determine the coordinates of the area to be repaired; and to move the lens position from the rough positioning position to the coordinates of the area to be repaired by operating the stage of the laser repair device.

[0048] This embodiment does not limit the specific method of precise positioning, as long as the coordinates of the area to be repaired can be determined, for example, the front coordinates of the defect area 5 can be obtained by using a defect inspection device; the front coordinates are the coordinates of the defect area 5 on the surface of the protective film 4; the front coordinates are converted to obtain the back coordinates of the defect area 5; the back coordinates are the coordinates of the defect area 5 on the surface of the photomask away from the protective film 4; the coordinates of the area to be repaired are determined based on the back coordinates.

[0049] S102: Depositing a light shielding film 6 in the area to be repaired to shield the light that enters the defective area 5 of the light shielding layer 2 from the surface of the protective film 4 and then penetrates the transparent substrate 1, thereby obtaining a repaired photomask.

[0050] This embodiment does not limit the specific area of ​​the shading film 6 . As long as the area of ​​the shading film 6 is larger than the area of ​​the defective area 5 , the light that enters the defective area 5 of the shading layer 2 from the surface of the protective film 4 and then penetrates the transparent substrate 1 can be blocked.

[0051] The present embodiment does not limit the specific method of depositing the light shielding film 6, as long as the light shielding film 6 can be formed in the area to be repaired, for example, the light shielding film 6 can be deposited in the area to be repaired by using the laser beam 7 in combination with the reaction gas 8; accordingly, before determining the area to be repaired on the surface of the photomask away from the protective film 4, it also includes: transferring the surface of the photomask away from the protective film 4 upward to the cavity of the laser repair equipment. The present embodiment does not limit the specific type of the reaction gas 8, as long as the film layer generated after the gas reaction can shield light, for example, the reaction gas 8 can be hexacarbonyl chromium gas 8, or a tungsten-containing gas.

[0052] The present embodiment does not limit the specific pulse number of the laser beam 7 . For example, the pulse number of the laser beam 7 may be 1 to 20 times, including both ends.

[0053] This embodiment does not limit the specific pulse overlap coefficient of the laser beam 7. For example, the pulse overlap coefficient of the laser beam 7 may be 0.5 to 1, including both ends.

[0054] This embodiment does not limit the specific laser energy of the laser beam 7. For example, the laser energy of the laser beam 7 can be 20% to 100%, including both ends. This embodiment does not limit the specific attenuation factor of the laser beam 7. For example, the attenuation factor of the laser beam 7 can be 10 to 60, including both ends.

[0055] This embodiment does not limit the specific deposition laser energy of the laser beam 7, for example, the deposition laser energy of the laser beam 7 can be 1% to 100%, including both ends. This embodiment does not limit the specific deposition time, for example, the deposition time can be 1ms to 500ms, including both ends.

[0056] This embodiment does not limit the specific deposition steps. For example, the deposition step may be 0.01 μm. 2 / s~1μm 2 / s, inclusive. Deposition step refers to the deposition area per second.

[0057] The present embodiment does not limit the specific flow rate of the reaction gas 8 . For example, the flow rate of the reaction gas 8 may be 100 ml / min to 20,000 ml / min, including both ends.

[0058] It should be noted that changes in the above parameters will affect the deposition viscosity, the size of the deposition area, and the success of the deposition. Therefore, corresponding parameters can be selected for deposition processing according to the actual situation of the defect.

[0059] Furthermore, in order to improve the qualification rate of the repaired photomask, after depositing the shading film 6 in the area to be repaired, the present embodiment can also confirm whether the repaired photomask is within the product specifications through spatial simulation imaging; when it is detected that the repaired photomask is not within the product specifications, the step of depositing the shading film 6 in the area to be repaired, until the step of confirming whether the repaired photomask is within the product specifications through spatial simulation imaging is executed in a loop, until it is detected that the repaired photomask is within the product specifications.

[0060] This embodiment does not limit the specific type of the photomask to be repaired, nor does it limit the specific type of the defect. For example, this embodiment can be applied to repair the defects in Table 1.

[0061] Table 1 Defect types applicable to this embodiment

[0062]

[0063] Based on the above embodiments, the present application deposits a layer of light shielding film 6 directly on the back of the photomask to shield the light that penetrates the transparent substrate 1 after entering the defective area 5 of the light shielding layer 2 from the surface of the protective film 4, and can repair the large black area hole defect on the photomask after filming without removing the protective film 4. This process step can be applied to specific 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, saves shipping time, and saves the consumption of the protective film 4.

[0064] Please refer to Figure 7 , Figure 7 A flowchart of another photomask repair method provided in an embodiment of the present application, the method may include:

[0065] S201: The photomask is transferred into the cavity of the laser repairing equipment with the surface thereof facing away from the protective film 4 facing upward.

[0066] S202: Determine the area to be repaired on the surface of the photomask away from the protective film 4; the area to be repaired corresponds to the defective area 5 of the light shielding layer 2 inside the photomask.

[0067] S203: using the laser beam 7 in combination with the reaction gas 8 to deposit a light shielding film 6 in the area to be repaired, so as to shield the light that enters the defective area 5 of the light shielding layer 2 from the surface of the protective film 4 and then penetrates the transparent substrate 1, thereby obtaining a repaired photomask.

[0068] S204: Confirm whether the repaired photomask is within the product specifications through spatial simulation imaging; when it is detected that the repaired photomask is not within the product specifications, loop the step of depositing a light-shielding film 6 on the area to be repaired until confirming whether the repaired photomask is within the product specifications through spatial simulation imaging, until it is detected that the repaired photomask is within the product specifications.

[0069] Based on the above embodiments, the present application uses a laser repair device to directly deposit a layer of shading film 6 on the back of the photomask to block the light that penetrates the transparent substrate 1 after entering the defective area 5 of the shading layer 2 from the surface of the protective film 4. Repair can be performed without removing the protective film 4, thereby optimizing the photomask repair flow process, greatly reducing the rework process steps, saving delivery time, and saving the consumption of the protective film 4.

[0070] Please refer to Figure 8 , Figure 8 A structural schematic diagram of a photomask provided in an embodiment of the present application, the photomask may include: a transparent substrate 1, a light-shielding layer 2, a protective film metal frame 3 and a protective film 4; the light-shielding layer 2 and the protective film metal frame 3 are arranged on the surface of the transparent substrate 1; the protective film metal frame 3 surrounds the light-shielding layer 2; the protective film 4 is arranged on the surface of the protective film metal frame 3 away from the transparent substrate 1 to cover the light-shielding layer 2; the surface of the transparent substrate 1 away from the protective film 4 is provided with a light-shielding film 6 prepared by the above-mentioned photomask repair method.

[0071] This embodiment does not limit the specific type of the light shielding layer 2. For example, the light shielding layer 2 may be a light shielding layer 2 containing a chromium layer, or a light shielding layer 2 containing a molybdenum silicide layer. The structure of the light shielding layer 2 containing a chromium layer may include a patterned chromium oxide layer 2.2 and a patterned chromium layer 2.1; the patterned chromium layer 2.1 is disposed on the surface of the transparent substrate 1; and the patterned chromium oxide layer 2.2 is disposed on the surface of the patterned chromium layer 2.1 away from the transparent substrate 1. This embodiment does not limit the specific type of the transparent substrate 1, and it may be any transparent carrier, for example, it may be a quartz layer substrate 1.

[0072] Based on the above embodiments, a light shielding film 6 is deposited on the back of the photomask of the present application, which can shield the light that enters the defective area 5 of the light shielding layer 2 from the surface of the protective film 4 and then penetrates the transparent substrate 1.

[0073] The following is a specific example to illustrate the above photomask repair process. Please refer to Fig. 9 , Fig. 9 A schematic diagram of a photomask repair method provided in an embodiment of the present application. The repaired part in this embodiment is Figure 8 The chrome layer photomask shown in the figure has a defect area in the patterned chrome layer 2.1. The repair process is as follows:

[0074] 1. It is found that there are defects in the protective film 4;

[0075] 2. Simulate defect imaging through the spatial simulation imaging system, and when it is determined that the defect area 5 is not within the product specification, execute the subsequent repair process;

[0076] 3. Defect repair:

[0077] (1) The quartz substrate 1 of the photomask is facing upward and the protective film 4 is facing downward, and is transferred into the cavity of the laser repair equipment;

[0078] (2) Using the lower right corner of the quartz substrate 1 as the coordinate origin, roughly locate the area to be repaired;

[0079] (3) Using defect inspection equipment, the coordinates (x, y) of the defect area 5 on the surface of the protective film 4 (with the lower left corner of the protective film 4 as the coordinate origin) are obtained. According to the relative positions of the coordinate origins of the lower left corner of the protective film 4 and the lower right corner of the quartz layer substrate, as well as the width of the photomask, the coordinates are converted to obtain the coordinates (152400-x-9200, y+9200) of the defect area 5 on the surface of the quartz layer substrate 1 (with the lower right corner of the quartz layer substrate 1 as the coordinate origin). The coordinates are the coordinates of the area to be repaired;

[0080] (4) By operating the stage of the laser repair device, the lens position is moved to the coordinates of the area to be repaired;

[0081] (5) Fig.10 As shown, a layer of light shielding film 6 is deposited on the area to be repaired by using a laser beam 7 in combination with hexacarbonyl chromium gas 8. The specific parameters for defect repair are shown in Table 2. The corresponding parameters are selected for deposition processing according to the actual situation of the defect.

[0082]

[0083] 4. Use the spatial simulation imaging system to confirm whether the repair effect is within the product specifications; if it is not within the product specifications, return to step 3. Repeat steps 3 and 4 until it is detected that the product is within the specifications before shipment. The repeatability test results are shown in Table 3. Among them, the spatial simulation imaging results represent the contrast between the defective area and the same pattern without defects.

[0084] Number of patches Spatial simulation imaging results (black area) 5 98％～102％

[0085] Compared with the traditional process, the repair process of this embodiment saves at least 6 process steps, greatly improves the delivery efficiency, and can save the consumption of at least one protective film 4.

[0086] 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.

[0087] 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, characterized in that: include: determining a region to be repaired on a surface of the photomask facing away from the protective film; The area to be repaired corresponds to a defective area of ​​the light shielding layer inside the photomask; A light shielding film is deposited on the area to be repaired to shield the light that enters the defective area of ​​the light shielding layer from the surface of the protective film and then penetrates the transparent substrate, thereby obtaining the repaired photomask.

2. The photomask repair method according to claim 1, characterized in that: Depositing a light-shielding film on the area to be repaired includes: Depositing a light-shielding film on the area to be repaired by using a laser beam in combination with a reaction gas; Accordingly, before determining the area to be repaired on the surface of the photomask away from the protective film, the method further includes: The photomask is transferred into the cavity of the laser repairing device with the surface facing away from the protective film facing upward.

3. The photomask repair method according to claim 2, characterized in that: The step of determining the area to be repaired on the surface of the photomask away from the protective film comprises: Roughly positioning the to-be-repaired area of ​​the photomask that is away from the protective film; Accurately positioning the area to be repaired to determine the coordinates of the area to be repaired; By operating the stage of the laser repairing device, the lens position is moved from the rough positioning position to the coordinates of the area to be repaired.

4. The photomask repair method according to claim 3, characterized in that: Accurately positioning the area to be repaired and determining the coordinates of the area to be repaired includes: Obtaining the front coordinates of the defect area using a defect inspection device; the front coordinates are the coordinates of the defect area on the surface of the protective film; The front coordinates are converted to obtain the back coordinates of the defective area; the back coordinates are the coordinates of the defective area on the surface of the photomask away from the protective film; The coordinates of the area to be repaired are determined according to the back surface coordinates.

5. The photomask repair method according to claim 1, characterized in that: After depositing the light shielding film on the area to be repaired, the method further comprises: Confirm whether the repaired photomask is within the product specifications through spatial simulation imaging; when it is detected that the repaired photomask is not within the product specifications, loop the step of depositing a light-shielding film in the area to be repaired, until confirming whether the repaired photomask is within the product specifications through spatial simulation imaging, until it is detected that the repaired photomask is within the product specifications.

6. The photomask repair method according to claim 2, characterized in that: The reaction gas is chromium hexacarbonyl gas.

7. The photomask repair method according to claim 2, characterized in that: The number of pulses of the laser beam is 1 to 20 times, including the values ​​at both ends; the pulse overlap coefficient of the laser beam is 0.5 to 1, including the values ​​at both ends; the laser energy of the laser beam is 20% to 100%, including the values ​​at both ends; the attenuation factor of the laser beam is 10 to 60, including the values ​​at both ends; the deposited laser energy of the laser beam is 1% to 100%, including the values ​​at both ends.

8. The photomask repair method according to claim 2, characterized in that: The deposition time is 1 ms to 500 ms, including both ends; Deposition step 0.01 μm 2 / s~1μm 2 / s, including the values ​​at both ends.

9. The photomask repair method according to claim 2, characterized in that: The flow rate of the reaction gas is 100 ml / min to 20000 ml / min, including both ends.

10. A photomask, characterized in that: include: Transparent substrate, light shielding layer, protective film metal frame and protective film; The light shielding layer and the protective film metal frame are arranged on the surface of the transparent substrate; The protective film metal frame surrounds the light shielding layer; The protective film is arranged on the surface of the protective film metal frame away from the transparent substrate to cover the shading layer; the surface of the transparent substrate away from the protective film is provided with a shading film prepared by the photomask repair method according to any one of claims 1 to 9.

Images