Mask repairing method

Abstract

A mask repairing method comprises the steps that a mask is provided, the mask comprises a light-transmitting substrate and a light shielding layer, and the light shielding layer is located on the top of the light-transmitting substrate and exposes part of the surface of the light-transmitting substrate; particle defect detection is carried out on the mask; under the condition that the defect of the particulate matter is detected, a deposition layer is formed on the particulate matter, and the deposition layer and the particulate matter serve as a particulate matter structure; and removing the particulate matter structure through a cleaning process. The deposition layer is formed on the particulate matter defect, and the vertical height and the volume of the particulate matter structure are increased, so that the effect that the particulate matter structure is infiltrated by the cleaning solution is improved, the particulate matter structure is easy to remove in a cleaning mode, the removal effect on the particulate matter defect is correspondingly improved, and the quality of the mask plate is improved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of semiconductor manufacturing, and in particular to a mask repair method. Background Art

[0002] With the rapid development of the semiconductor integrated circuit (IC) industry, semiconductor technology continues to move towards smaller process nodes driven by Moore's Law, making integrated circuits develop in the direction of smaller size, higher circuit precision and higher circuit complexity.

[0003] As a core component of the photolithography process, the mask is responsible for accurately transferring complex circuit patterns onto semiconductor chips. The precise patterns on its surface are generated by advanced computer-aided design, and these patterns are transformed into the structure of tiny electronic components through the photolithography process, which determines the performance and function of the chip. The manufacture and design of the mask directly affects the accuracy and efficiency of semiconductor manufacturing. As chip size continues to shrink and functions continue to increase, mask technology continues to evolve to meet the needs of higher resolution and more complex circuits.

[0004] However, the quality of the mask still needs to be improved. Summary of the invention

[0005] The problem solved by the embodiment of the present invention is to provide a mask repair method to improve the quality of the mask.

[0006] To solve the above problems, the present invention provides a mask repair method, comprising: providing a mask, wherein the mask comprises a light-transmitting substrate and a light-shielding layer, wherein the light-shielding layer is located on the top of the light-transmitting substrate and exposes a portion of the surface of the light-transmitting substrate; performing particle defect detection on the mask; when the particle defect is detected, forming a deposition layer on the particle, wherein the deposition layer and the particle serve as a particle structure; and removing the particle structure through a cleaning process.

[0007] Compared with the prior art, the technical solution of the embodiment of the present invention has the following advantages:

[0008] In the mask provided by the embodiment of the present invention, when a particle defect is detected, a deposition layer is formed on the particle, and the deposition layer and the particle serve as a particle structure, and the particle structure is removed by a cleaning process; by forming a deposition layer on the particle defect, the vertical height and volume of the particle structure are increased, thereby improving the effect of the particle structure being infiltrated by the cleaning liquid, making it easy to remove the particle structure by cleaning, thereby correspondingly improving the effect of removing the particle defect, and thereby improving the quality of the mask. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic diagram of the structure of a defective mask;

[0010] Figures 2 to 5 It is a schematic structural diagram corresponding to each step in an embodiment of a mask repair method of the present invention. DETAILED DESCRIPTION

[0011] At present, the quality of the mask still needs to be improved. Now, combined with a structural schematic diagram of a mask defect, the reasons why the quality of the mask needs to be improved are analyzed.

[0012] refer to Figure 1 The mask 10 includes a light-transmitting substrate 11 and a light-shielding layer 12 . The light-shielding layer 12 is located on the top of the light-transmitting substrate 11 and exposes a portion of the surface of the light-transmitting substrate 11 .

[0013] The top of the transparent substrate 11 on the side of the light shielding layer 12 has particles 13 .

[0014] At present, small-sized particles 13 are generally generated during the manufacturing process of the mask 10, which become a type of defect on the mask 10. Due to their extremely small size, such particles 13 are significantly affected by the van der Waals force on the surface of the mask 10. Moreover, in the cleaning process, the cleaning liquid has a poor wetting effect on the small-sized mask pattern (as shown by the wetting interface 14 between the cleaning liquid and the mask surface), and the cleaning liquid cannot penetrate to the bottom, and the flushing area of ​​the particles 13 is small. When the flow velocity at the bottom of the particles 13 is slow, the mechanical force of the particles 13 being flushed is smaller than the van der Waals force between the particles 13 and the surface of the mask 10, and the particles 13 cannot be removed.

[0015] In the prior art, etching gas is usually used to chemically react with the particles 13 to form gas, thereby removing the particles 13. However, for particle defects with uncertain materials, the current etching gas cannot react chemically with the particles 13 well, resulting in the particles 13 being unable to be removed. In addition, the etching gas usually also causes certain damage to the surface of the mask plate 10 near the etching area.

[0016] In other existing technologies, a specially made atomic force microscope probe is used to contact the particle defect, and mechanical force is used to move it from the transparent area of ​​the mask to the opaque area of ​​the mask to complete the defect repair. However, this repair method is costly and has extremely high annual maintenance costs.

[0017] In order to solve the above technical problems, an embodiment of the present invention provides a mask repair method, comprising: providing a mask, the mask comprising a light-transmitting substrate and a light-shielding layer, the light-shielding layer being located on the top of the light-transmitting substrate and exposing a portion of the surface of the light-transmitting substrate; performing particle defect detection on the mask; when the particle defect is detected, forming a deposition layer on the particle, the deposition layer and the particle serving as a particle structure; and removing the particle structure through a cleaning process.

[0018] In the mask provided by the embodiment of the present invention, when a particle defect is detected, a deposition layer is formed on the particle, and the deposition layer and the particle serve as a particle structure, and the particle structure is removed by a cleaning process; by forming a deposition layer on the particle defect, the vertical height and volume of the particle structure are increased, thereby improving the effect of the particle structure being infiltrated by the cleaning liquid, making it easy to remove the particle structure by cleaning, thereby correspondingly improving the effect of removing the particle defect, and thereby improving the quality of the mask.

[0019] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present invention more obvious and understandable, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0020] Figures 2 to 5 It is a schematic structural diagram corresponding to each step in an embodiment of a mask repair method of the present invention.

[0021] refer to Figure 2 , Figure 2 It is a cross-sectional view along the normal direction of the light-transmitting substrate.

[0022] A mask plate 500 is provided. The mask plate 500 includes a light-transmitting substrate 501 and a light-shielding layer 502 . The light-shielding layer 502 is located on the top of the light-transmitting substrate 501 and exposes a portion of the surface of the light-transmitting substrate 501 .

[0023] The mask 500 is used in semiconductor technology to transfer precise patterns onto semiconductor structures, thereby defining structures and circuits of tiny electronic components.

[0024] In this embodiment, the mask 500 is a mask with small-sized graphics. In order to meet the requirements of higher resolution and more complex circuits, the graphics size of the mask 500 gradually decreases, and the line width of the groove surrounded by the light shielding layer 502 and the light-transmitting substrate 501 gradually decreases accordingly. For example, the line width of the groove is less than or equal to 1 micron.

[0025] In other embodiments, if the material of the particles cannot be removed by chemical reaction, the solution can also be used for masks with large-size patterns.

[0026] The light-transmitting substrate 501 is used to allow light to penetrate the mask when the mask transfers a pattern, thereby transferring the pattern to the photoresist layer and the semiconductor structure.

[0027] The material of the light-transmitting substrate 501 includes glass, quartz or silicon dioxide.

[0028] The light shielding layer 502 is used to block the area that does not need to be exposed in the photolithography process, ensuring that only specific patterns are transferred to the photoresist and the semiconductor structure through the light-transmitting area.

[0029] The structure of the light shielding layer 502 includes one or more of chromium, molybdenum silicide, silicon and molybdenum. In other embodiments, the light shielding layer may also be made of other light shielding materials.

[0030] Continue to refer Figure 2 , performing particle defect detection on the mask plate 500.

[0031] The particle defect detection is used to detect whether there are particles 510 on the mask 500 .

[0032] The sources of the particles 510 include: impurity particles contained in the chemical solution used in the previous process, particles generated by the wear of the mask structure, or particles in the environment.

[0033] The particles 510 are located on the top of the light-transmitting substrate 501 at the side of the light-shielding layer 502 , and the size of the particles 510 is smaller than the size of the light-shielding layer 502 .

[0034] It should be noted that, during the process of detecting particles on the mask 500 , a positioning operation of the particles 510 is also performed.

[0035] By performing a positioning operation on the particle 510, the coordinates of the particle 510 can be obtained. In the present solution, when a deposition layer is formed by local chemical vapor deposition, the same coordinates are used for precise positioning to ensure that a deposition layer is formed only on the particle 510, thereby reducing the probability of being unable to remove the particle 510 due to the deposition layer connecting the particle 510 to the mask plate 500.

[0036] refer to Figure 3 and Figure 4 When the particle defect is detected, a deposition layer 511 is formed on the particle 510 , and the deposition layer 511 and the particle 510 serve as a particle structure 520 .

[0037] By forming a deposition layer 511 on the particle 510, the volume and height of the particle 510 can be significantly increased to form a particle structure 520, thereby significantly increasing the force-bearing area of ​​the particle structure 520 in the subsequent cleaning process, so that the mechanical force exerted on the particle structure 520 is greater than the van der Waals force between it and the mask surface, thereby making it easy to remove the particle structure 520 by cleaning.

[0038] The material of the deposition layer 511 includes one or more of silicon dioxide, chromium, molybdenum, aluminum oxide, polyethylene and polypropylene.

[0039] The material of the deposition layer 511 is a solid substance that can be generated from gaseous reactants, so the selection range is relatively wide.

[0040] In this embodiment, in the step of forming the deposition layer 511 on the particle 510, the size of the particle structure 520 satisfies that: the volume wetted by the cleaning liquid in the cleaning process accounts for more than 10% of the total volume.

[0041] The size of the particle structure 520 satisfies that the volume wetted by the cleaning liquid in the cleaning process accounts for more than 10% of the total volume, which can significantly increase the force-bearing area of ​​the particle structure 520 in the subsequent cleaning process, so that the mechanical force exerted on the particle structure 520 is greater than the van der Waals force between it and the mask surface, thereby making it easy to remove the particle structure 520 by cleaning.

[0042] Continue to refer Figure 3 and Figure 4 In the step of forming the deposition layer 511 on the particulate matter 510 , deposition is performed along the normal direction of the light-transmitting substrate 501 to form the deposition layer 511 .

[0043] By changing the height dimension of the granular structure 520 , the volume can be increased in the height direction.

[0044] Furthermore, the deposition is performed along the normal direction of the transparent substrate 501 , so as to better avoid the problem that the deposition layer 511 connects the particle 510 with the mask 500 , resulting in the inability to remove the particle 510 .

[0045] In the step of forming the deposition layer 511 on the particle 510, the vertical height of the particle structure 520 along the normal direction of the transparent substrate 501 is 100 nanometers to 10,000 nanometers. The vertical height of the particle structure 520 along the normal direction of the transparent substrate 501 is 100 nanometers to 10,000 nanometers, which is easy to increase the volume of the particle structure 520 infiltrated by the cleaning liquid in the cleaning process, thereby significantly increasing the force-bearing area of ​​the particle structure 520 in the subsequent cleaning process, so that the mechanical force of the particle structure 520 being washed is greater than the van der Waals force between it and the mask surface, so that the particle structure 520 is easy to remove by cleaning.

[0046] The vertical height of the particle structure 520 along the normal direction of the transparent substrate 501 should not be too large or too small. If the vertical height of the particle structure 520 along the normal direction of the transparent substrate 501 is too small, it is easy to cause the particle structure to be poorly wetted by the cleaning liquid, affecting the removal effect through the cleaning process; if the vertical height of the particle structure 520 along the normal direction of the transparent substrate 501 is too large, it is easy to cause the process time required to form the deposition layer 511 on the particle 510 to be too long. Therefore, the vertical height of the particle structure 520 along the normal direction of the transparent substrate 501 is 100 nanometers to 10,000 nanometers.

[0047] In the step of forming the deposition layer 511 on the particle 510 , the horizontal width of the particle structure 520 along a direction parallel to the light-transmitting substrate 501 is 50 nanometers to 3000 nanometers.

[0048] The horizontal width of the particle structure 520 along the direction parallel to the transparent substrate 501 is 50 nanometers to 3000 nanometers, which can also easily increase the volume of the particle structure 520 that is infiltrated by the cleaning liquid during the cleaning process, thereby facilitating the removal of the particle structure 520 by cleaning.

[0049] The horizontal width of the particle structure 520 along the direction parallel to the light-transmitting substrate 501 should not be too large or too small. If the horizontal width of the particle structure 520 along the direction parallel to the light-transmitting substrate 501 is too small, it is easy to cause the particle structure 520 to be poorly wetted by the cleaning liquid, affecting the effect of removal by the cleaning process; if the horizontal width of the particle structure 520 along the direction parallel to the light-transmitting substrate 501 is too large, it is easy to cause the particle structure 520 to be connected to the mask pattern, making it difficult to remove by the cleaning process. Therefore, the horizontal width of the particle structure 520 along the direction parallel to the light-transmitting substrate 501 is 50 nanometers to 3000 nanometers.

[0050] refer to Figure 3The process of forming the deposition layer 511 includes a chemical vapor deposition process.

[0051] The chemical vapor deposition process has the advantages of uniform deposition, applicability to complex structures, controllable growth rate, multi-material applicability, and high temperature processing capability.

[0052] In this embodiment, the gas reactants generate a deposition layer 511 whose material is solid through a chemical vapor deposition process, which reduces the difficulty of operation and facilitates accurate positioning of the formation position of the deposition layer 511.

[0053] In this embodiment, based on the position of the particle 510, a deposition layer 511 is formed on the top of the particle 510 by local deposition.

[0054] By forming a deposition layer 511 on the top of the particle 510 by local deposition, the volume and height of the particle structure 520 can be increased while the deposition layer 511 can be selectively formed at the location of the particle 510, thereby preventing the deposition layer 511 from connecting the particle 510 to the mask plate 500, thereby reducing the probability of being unable to remove the particle structure 520.

[0055] In this embodiment, the chemical vapor deposition process includes an electron beam deposition process, an ion beam deposition process or a laser deposition process.

[0056] The electron beam deposition process, the ion beam deposition process or the laser deposition process can precisely control the formation position, so that the deposition layer 511 can be formed on the top of the particle 510 by local deposition.

[0057] Specifically, in an atmosphere of reaction gas, an electron beam, an ion beam or a laser beam is used to precisely position and irradiate the top of the particle 510 to excite the reaction gas and form a solid substance as the deposition layer 511 .

[0058] It should be noted that in Figure 3 In the figure, the straight line above the particle 510 is used to represent the electron beam, ion beam or laser beam, and the elliptical coating around the straight line is used to represent the reaction gas.

[0059] The electron beam deposition process has a higher resolution and a clearer image, and is suitable for small-pattern masks. Furthermore, the electron beam deposition process does not damage the mask, and is more suitable for a variety of application scenarios.

[0060] The process parameters of the electron beam deposition process include: a current intensity of 1 picoampere to 1 nanoampere, and an acceleration voltage of 0.1 kilovolts to 10 kilovolts.

[0061] The current intensity of the electron beam deposition process should not be too large or too small. If the current intensity of the electron beam deposition process is too large, it is easy to damage the mask pattern; if the current intensity of the electron beam deposition process is too small, it is easy to cause poor excitation effect on the reaction gas, thereby increasing the reaction time. Therefore, the current intensity of the electron beam deposition process is 1 picoampere to 1 nanoampere.

[0062] The acceleration voltage of the electron beam deposition process should not be too large or too small. If the acceleration voltage of the electron beam deposition process is too large, the electron beam may hit the mask surface and damage the mask pattern; if the acceleration voltage of the electron beam deposition process is too small, the electron beam may not be able to reach the surface of the particles. Therefore, the acceleration voltage of the electron beam deposition process is 0.1 kV to 10 kV.

[0063] The ion beam deposition process has high resolution and clear images, and is also suitable for small pattern masks.

[0064] The process parameters of the ion beam deposition process include: the ion source includes a gallium ion source, and the acceleration voltage is 0.1 kV to 10 kV.

[0065] The acceleration voltage of the ion beam deposition process should not be too large or too small. If the acceleration voltage of the ion beam deposition process is too large, the ion beam may hit the mask surface and damage the mask pattern; if the acceleration voltage of the ion beam deposition process is too small, the electron beam may not be able to reach the surface of the particles. Therefore, the acceleration voltage of the ion beam deposition process is 0.1 kV to 10 kV.

[0066] The laser deposition process is suitable for masks with large patterns.

[0067] The process parameters of the laser deposition process include: laser intensity is 0.1 mW to 10 mW.

[0068] The laser intensity of the laser deposition process should not be too high or too low. If the laser intensity of the laser deposition process is too high, it is easy to damage the mask pattern; if the laser intensity of the laser deposition process is too low, it is easy to cause poor excitation effect on the reaction gas. Therefore, the laser intensity of the laser deposition process is 0.1 milliwatts to 10 milliwatts.

[0069] It should be noted that, in other embodiments, on the premise that the formation position can be accurately controlled, physical vapor deposition can also be used to form the deposition layer.

[0070] refer to Figure 5 After the particle structure 520 is formed, the mask repair method further includes: removing the particle structure 520 through a cleaning process.

[0071] The particle structure 520 is removed, thereby achieving the effect of removing particle defects.

[0072] The cleaning liquid used in the cleaning process includes: acidic liquid, alkaline liquid, water or other liquids with good wettability.

[0073] It should be noted that Figure 5 The coating covering the mask 500 and the particle structure 520 is used to represent a cleaning liquid.

[0074] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A mask repair method, It is characterized in that include: Providing a mask, the mask comprising a light-transmitting substrate and a light-shielding layer, the light-shielding layer being located on the top of the light-transmitting substrate and exposing a portion of the surface of the light-transmitting substrate; Performing particle defect detection on the mask; When the particle defect is detected, a deposition layer is formed on the particle, wherein the deposition layer and the particle serve as a particle structure; The particle structure is removed by a cleaning process.

2. The mask repair method according to claim 1, It is characterized in that During the process of detecting particles on the mask, a particle positioning operation is also performed; Based on the position of the particles, a deposition layer is formed on top of the particles by local deposition.

3. The mask repair method according to claim 1 or 2, It is characterized in that The process of forming the deposition layer includes a chemical vapor deposition process.

4. The mask repair method according to claim 3, It is characterized in that The chemical vapor deposition process includes an electron beam deposition process, an ion beam deposition process or a laser deposition process.

5. The mask repair method according to claim 4, It is characterized in that The process parameters of the electron beam deposition process include: a current intensity of 1 picoampere to 1 nanoampere, and an acceleration voltage of 0.1 kilovolts to 10 kilovolts.

6. The mask repair method according to claim 4, It is characterized in that The process parameters of the ion beam deposition process include: the ion source includes a gallium ion source, and the acceleration voltage is 0.1 kV to 10 kV.

7. The mask repair method according to claim 4, It is characterized in that The process parameters of the laser deposition process include: laser intensity is 0.1 mW to 10 mW.

8. The mask repair method according to claim 1, It is characterized in that The material of the deposition layer includes one or more of silicon dioxide, chromium, molybdenum, aluminum oxide, polyethylene and polypropylene.

9. The mask repair method according to claim 1, It is characterized in that In the step of forming a deposition layer on the particulate matter, deposition is performed along a normal direction of the light-transmitting substrate to form the deposition layer.

10. The mask repair method according to claim 1, It is characterized in that In the step of forming a deposition layer on the particles, the size of the particle structure satisfies that: the volume wetted by the cleaning liquid in the cleaning process accounts for more than 10% of the total volume.

11. The mask repair method according to claim 1, 9 or 10, It is characterized in that In the step of forming a deposition layer on the particles, a vertical height of the particle structure along the normal direction of the light-transmitting substrate is 100 nanometers to 10,000 nanometers.

12. The mask repair method according to claim 1, 9 or 10, It is characterized in that In the step of forming a deposition layer on the particles, the horizontal width of the particle structure along a direction parallel to the light-transmitting substrate is 50 nanometers to 3000 nanometers.

13. The mask repair method according to claim 1, It is characterized in that The process parameters of the cleaning process include: the cleaning liquid includes water, sulfuric acid or ammonia water.

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