A reticle, lithographic apparatus and detection method

Abstract

The application relates to the technical field of semiconductors, and provides a photomask, a photolithography device and a detection method. The photomask comprises a substrate, a frame, a pattern area and a protective film. The frame is fixedly arranged on the substrate and is formed with an opening on a side facing away from the substrate. The pattern area is located in the frame and is arranged on the surface of the substrate. The protective film covers the opening. The protective film comprises a working area and a peripheral area. The peripheral area surrounds the outer periphery of the working area and is bonded to the end face of the frame with the opening. The surface of the peripheral area facing away from the frame is provided with a to-be-detected point. The photomask, the photolithography device and the detection method provided by the application can realize damage detection of the protective film by detecting only the to-be-detected point on the protective film.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and in particular to a photomask, a photolithography apparatus, and a detection method. Background Technology

[0002] A pattern is set inside the mask, which is transferred to the wafer through photolithography. A protective film is set on top of the pattern to reduce particles falling onto the pattern. The protective film is attached to the frame by an adhesive method. During the photolithography process, the mask vibrates at high speed inside the photolithography equipment, which increases the stress at the connection between the protective film and the frame, and can cause the protective film to crack. Therefore, after the protective film has been in use for a period of time, a detection device is needed to detect cracks in the protective film. The detection devices in related technologies all detect damage by directly inspecting the protective film. Therefore, the surface of the protective film needs to be made as flat as possible to reduce the possibility of inaccurate measurement parameters and the risk of scratching the protective film by this measurement method. Summary of the Invention

[0003] This application provides a photomask, a photolithography device, and a detection method, enabling the detection of damage to the protective film by simply detecting the test points on the protective film during damage detection.

[0004] The technical solution of this application embodiment is implemented as follows: One embodiment of this application provides a photomask, including: substrate; A frame is fixedly mounted on the substrate, and an opening is formed on the side of the frame facing away from the substrate. A patterned area is located within the frame and disposed on the surface of the substrate; A protective film covers the opening. The protective film includes a working area and a peripheral area. The peripheral area surrounds the outer periphery of the working area and is adhered to the end face of the frame with the opening. The surface of the peripheral area facing away from the frame has test points.

[0005] In one embodiment, there are multiple test points, which are spaced apart circumferentially along the protective film.

[0006] In one embodiment, the interval between two adjacent test points is between 10 mm and 25 mm.

[0007] In one embodiment, the dimension between the test point and the inner surface of the frame is less than 1 mm.

[0008] In one embodiment, the test point is a protrusion protruding from the surface of the protective film.

[0009] In one embodiment, the equivalent circle diameter of the protrusion is between 20 μm and 40 μm.

[0010] In one embodiment, the convex point is obtained by the following steps: Take a strand of silk thread no larger than four mils and twist it into a ply; One end of the stranded filaments is fixed to the fabric tape, and the fabric tape is folded. Holding the folded cloth tape, dip the other end of the stranded filaments into UV-curable adhesive and bring it into contact with the protective film; The UV-curable adhesive is cured by irradiating it with UV light.

[0011] Another embodiment of this application provides a photolithography apparatus, including a detection device and a photomask in any of the above embodiments, wherein the detection device is used to identify the test point.

[0012] In one embodiment, the detection device includes a beam emitter and a detector, the beam emitter being configured to emit a detection beam toward the peripheral region, and the detector being configured to receive the detection beam reflected from the point to be measured.

[0013] In one embodiment, the detection device is an integrated mask detection system.

[0014] In another aspect, this application provides a detection method applied to the photolithography apparatus in any of the above embodiments, the detection method comprising: The detection device scans the surrounding area to detect the point to be tested. If the test point is not detected, the protective film is determined to be damaged; if the test point is detected, the protective film is determined to be intact.

[0015] In one embodiment, the step of scanning the peripheral area using the detection device to detect the point to be tested includes: The location of the point to be measured is marked as a feature location, and the detection device scans the feature location to obtain real-time coordinates and corresponding real-time size parameters; Based on the real-time coordinates and real-time size parameters, and the initial coordinates and corresponding initial size parameters of the point to be measured, determine whether they match; If the real-time coordinates and the real-time size parameters do not match the initial coordinates and the initial size parameters, it is determined that the point to be measured has not been detected. If the real-time coordinates and the real-time size parameters match the initial coordinates and the initial size parameters, it is determined that the point to be measured has been detected.

[0016] This application provides a photomask, a photolithography apparatus, and a detection method. By dividing the protective film into an outer region and a working region, the outer region surrounds the working region and is bonded to the open end face of the frame, where test points are located. When the outer region breaks due to tension with the frame during photolithography, the test points also break and / or change position, allowing for detection and identification by the detection device. In other words, the breakage of the protective film affects the test points. Thus, without directly performing global detection of the protective film, the physical state of the test points alone can determine whether the protective film is damaged. The judgment criteria are relatively simple, and the structure of the test points is also relatively simple. This not only improves the reliability and efficiency of protective film damage detection but also reduces the risk of scratching the protective film during detection. Furthermore, since the outer region is located on the periphery of the working region, it reduces the impact on the light transmittance of the working region. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the photomask and detection device provided in the embodiments of this application. The protective film is intact, and the detector can receive the reflected detection beam. The arc arrow in the figure indicates the scanning direction, the one-way solid arrow indicates the emission direction of the detection beam, and the one-way dashed arrow indicates the reflection direction of the detection beam. Figure 2 This is a schematic diagram of the structure of a photomask and a detection device provided in another embodiment of this application, wherein the protective film is damaged and the detector cannot receive the reflected detection beam; Figure 3 This is a schematic diagram of the structure of the protective film and the test point provided in another embodiment of this application; Figure 4 This is a schematic diagram of the structure of a photomask provided in another embodiment of this application; Figure 5 This is a schematic diagram of the structure of the thread and the cloth tape provided in another embodiment of this application, wherein the thread is bonded to the cloth tape and the cloth tape is folded for easy handling; Figure 6 This is a schematic diagram of the structure of the thread, cloth tape and adhesive provided in another embodiment of the present application, wherein the thread with the cloth tape is adhered to is dipped in the adhesive; Figure 7 This is a schematic diagram of the structure of a photomask, filaments, and cloth-based adhesive tape provided in another embodiment of this application, wherein the filaments dipped in adhesive come into contact with the protective film to transfer the adhesive to the protective film. Figure 8 This is a schematic flowchart of a detection method provided in another embodiment of this application.

[0018] Explanation of reference numerals in the attached figures 100. Photomask; 1. Substrate; 2. Frame; 2a. Opening; 3. Patterned area; 4. Protective film; 41. Working area; 42. Peripheral area; 5. Test point; 200. Detection device; 201. Beam emitter; 202. Detector; 300. Wire; 400. Cloth tape; 500. Adhesive. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limitations on this application. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] During the photolithography process, the photomask vibrates at high speed inside the photolithography equipment, which increases the stress at the connection between the protective film and the frame, and then causes the protective film to crack. Since the photolithography equipment does not have a protective film detection module, manual visual inspection is often used, which has low reliability.

[0021] In view of this, this application provides a photomask 100, a photolithography apparatus, and a detection method. To better understand the photomask 100 provided in this application, the photolithography apparatus will be described first.

[0022] One aspect of this application provides a photolithography apparatus, which includes a detection device 200 and a photomask 100 in any of the following embodiments.

[0023] For example, lithography equipment can be a UV (ultraviolet) lithography machine, a DUV (deep ultraviolet) lithography machine, or an EUV (extreme ultraviolet) lithography machine, etc.

[0024] For example, a photolithography apparatus may include a housing and a light source system. The photomask 100 and the light source system are disposed within the housing. The wafer may be disposed below the photomask 100. The exposure beam emitted by the light source system is shaped and can pass through the photomask 100, and then be projected onto the photoresist on the wafer surface for exposure through a multi-stage lens.

[0025] Another embodiment of this application provides a photomask 100, please refer to... Figures 1 to 7 The photomask 100 includes a substrate 1, a frame 2, a patterned area 3, and a protective film 4. The frame 2 is fixedly disposed on the substrate 1, and an opening 2a is formed on the side of the frame 2 facing away from the substrate 1. The patterned area 3 is located inside the frame 2 and disposed on the surface of the substrate 1. The protective film 4 covers the opening 2a and includes a working area 41 and a peripheral area 42. The peripheral area 42 surrounds the outer periphery of the working area 41 and is bonded to the end face of the frame 2 with the opening 2a. The surface of the peripheral area 42 facing away from the frame 2 is provided with test points 5.

[0026] Opening 2a can be formed at the top of frame 2, and opening 2a can communicate with the internal space of frame 2.

[0027] Substrate 1 refers to the structure used to support the pattern area 3 and to provide support for the frame 2 and the protective film 4. The substrate 1 can be made of quartz glass so that the exposure beam emitted by the light source system can pass through.

[0028] Pattern area 3 refers to the design pattern of photolithography; pattern area 3 can be made of opaque material so that the exposure beam can be absorbed when it passes through its surface, while the blank areas in pattern area 3 allow the exposure beam to pass through.

[0029] Frame 2 refers to the structure used to support the protective film 4; the shape of frame 2 is not limited, for example, it can be a hollow cuboid or cube, etc. Frame 2 can be made of opaque material.

[0030] The protective film 4 is a film-like structure that can intercept impurities such as particles to reduce the amount falling from the opening 2a onto the pattern area 3. The shape of the protective film 4 is not limited; for example, it can be rectangular or square. The protective film 4 is made of a light-transmitting material, allowing the exposure beam to pass directly through the protective film 4 to reach the pattern area 3.

[0031] The working area 41 of the protective film 4 refers to the area through which the exposure beam can pass and act on the entire pattern area 3, that is, the projection along the emission direction of the exposure beam. The projection area of ​​the pattern area 3 is located within the projection area of ​​the working area 41.

[0032] The outer perimeter region 42 refers to the structure used to connect the working area 41 and the frame 2; for example, the outer perimeter region 42 can be adhered to the top of the frame 2 using adhesive or the like. The position of the outer perimeter region 42 can be defined by the test point 5. The area between the test point 5 and the center of the protective film 4 along the inner and outer directions can be the working area 41, and the rest is the outer perimeter region 42.

[0033] The test point 5 refers to a structure that can be identified by the detection device 200. For example, the test point 5 can be a protrusion, groove, or other structure with significant features that are different from a planar design.

[0034] For example, the detection device 200 may be a camera, a laser, etc.

[0035] It should be noted that if the protective film 4 is cracked at the location where the test point 5 is set, the stress will be transmitted to the test point 5, causing the position of the test point 5 to change and / or the test point 5 to crack. Then it can be identified and captured by the detection device 200. In other words, by detecting the test point 5 through the detection device 200, it can be determined whether the protective film 4 is damaged.

[0036] For example, the test point 5 can be integrally formed with the protective film 4. That is, the test point 5 can be processed at the same time as the protective film 4. Of course, the test point 5 can also be set on the protective film 4 through a later process after the protective film 4 is processed.

[0037] It should be noted that the outer area 42 and the working area 41 do not refer to a planar area on the surface of the protective film 4, but rather to two structural parts of the protective film 4.

[0038] The photomask 100 provided in this embodiment divides the protective film 4 into an outer region 42 and a working region 41. The outer region 42 surrounds the outer periphery of the working region 41 and is bonded to the end face of the frame 2 with an opening 2a. It is provided with test points 5. When the outer region 42 is pulled and broken during the photolithography process, the test points 5 will also be damaged and / or change position, so that they can be detected and identified by the detection device 200. In other words, the breakage of the protective film 4 will affect the test points 5. Thus, it is not necessary to directly perform global detection on the protective film 4. It is possible to determine whether the protective film 4 is damaged by detecting the physical state of the test points 5. The judgment condition is relatively simple, and the structure of the test points 5 is also relatively simple. This not only improves the reliability and detection efficiency of the protective film 4 damage detection, but also reduces the risk of scratching the protective film 4 during the detection process to a certain extent. Moreover, since the outer region 42 is set on the outer periphery of the working region 41, the influence on the light transmittance of the working region 41 can be reduced.

[0039] The photolithography equipment provided in this application, based on the advantages of the aforementioned photomask 100, features high detection reliability and high wafer production yield.

[0040] In some embodiments, the test point 5 is located between the inner surface of the frame 2 and the working area 41 along the inward and outward directions.

[0041] This allows the test point 5 to provide feedback on the damage status at the connection between the protective film 4 and the inner surface of the frame 2, thereby improving the reliability of the damage detection of the protective film 4.

[0042] In one embodiment, please refer to Figure 3 There are multiple test points 5, which are spaced apart along the circumference of the protective film 4.

[0043] Here, "multiple test points 5" means that the number of test points 5 is greater than two. Please refer to [link / reference]. Figure 3 The number of test points 5 can be twelve, and the twelve test points 5 can be set at intervals along the circumference of the protective film 4.

[0044] It should be noted that there is a gap between two adjacent test points 5. The gap between two adjacent test points can be the same, such as the gap between the first test point 5 and the second test point 5 can be 10mm, and the gap between the second test point 5 and the third test point 5 can be 10mm. Of course, the gap between two adjacent test points can also be different, such as the gap between the first test point 5 and the second test point 5 can be 10mm, and the gap between the second test point 5 and the third test point 5 can be 15mm.

[0045] For example, taking a rectangular shape for the protective film 4, when setting test points 5 on both sides of the protective film 4 along its length, the length direction can be used as the central axis, and then the central axis can be used as the starting point for setting test points 5 at equal intervals on both sides of the width direction; when setting test points 5 on both sides of the protective film 4 along its width direction, the width direction can be used as the central axis, and then the central axis can be used as the starting point for setting test points 5 at equal intervals on both sides of the length direction. The spacing of the test points 5 arranged along the width direction can be different from the spacing of the test points 5 arranged along the length direction, or it can be the same.

[0046] Here, by setting multiple test points 5 at intervals along the circumference of the protective film 4, it is possible to more comprehensively determine whether the protective film 4 is damaged along the circumference, thereby further improving the reliability of the damage detection of the protective film 4.

[0047] In one embodiment, please refer to Figure 3 The interval D1 between two adjacent test points 5 is between 10mm and 25mm.

[0048] For example, the interval D1 between two adjacent test points 5 can be 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm or 25mm, etc.

[0049] Here, by setting an appropriate interval distance D1, not only can the impact on the structural performance of the protective film 4 be reduced and the processing difficulty of the protective film 4 be lowered, but the damage of the protective film 4 can also be more comprehensively judged, which is convenient for subsequent structural optimization of the damaged location.

[0050] In one embodiment, please refer to Figure 4 The dimension D2 between the test point 5 and the inner surface of the frame 2 is less than 1mm.

[0051] It should be noted that the dimension D2 here refers to the smaller of the two dimensions formed between the measured point 5 along the inside and outside direction and the inner surface of the frame 2.

[0052] For example, the dimension D2 between the test point 5 and the inner surface of the frame 2 along the inside and outside direction can be 0.9mm, 0.8mm, 0.7mm, 0.6mm, 0.5mm, 0.4mm, 0.3mm, 0.2mm or 0.1mm, etc.

[0053] In this way, by setting the test point 5 at a suitable distance from the frame 2, not only can the damage to the protective film 4 be reported more reliably, but the influence of the test point 5 on the light transmittance of the working area 41 can also be reduced, thereby improving the working stability of the working area 41.

[0054] It should be noted that the minimum distance between the test point 5 and the frame 2 along the inside and outside direction should not be too small. That is, the position of the test point 5 should not be too close to the connection between the frame 2 and the protective film 4. Otherwise, the detection device 200 may miss or fail to identify the test point.

[0055] In one embodiment, please refer to Figure 1 and Figure 2 The detection device 200 includes a beam emitter 201 and a detector 202. The beam emitter 201 is configured to emit a detection beam toward the peripheral region 42, and the detector 202 is used to receive the detection beam reflected by the test point 5.

[0056] The beam emitter 201 can be a laser emitter. It scans the peripheral area 42 by emitting a probe beam along the inward and outward directions. When the probe beam hits the test point 5, the test point 5 will change the reflection path of the probe beam so that the detector 202 set at the corresponding position can receive and identify it. At this time, it can be determined that the state of the test point 5 is intact, thus determining that the protective film 4 is not damaged. When the beam emitter 201 emits a probe beam towards the location of the test point 5, if the detector 202 at the corresponding position does not receive the reflected probe beam, it can be determined that the test point 5 is damaged and / or its position has changed, thus determining that the protective film 4 is damaged.

[0057] In other words, the detection device 200 provided in this application emits a probe towards the test point 5 on the uneven surface, and then uses the detection beam 202 set at the corresponding position to receive the reflected probe beam as a judgment condition to determine whether the test point 5 is damaged and / or its position changes, and then determines whether the protective film 4 is damaged.

[0058] Here, by setting up a beam emitter 201 and a detector 202, and utilizing the principle that the test point 5 can change the reflection path of the detection beam, the detector 202 located at the corresponding position can identify and detect, thereby determining whether the state and / or position of the test point 5 has changed, and thus determining whether the protective film 4 has been damaged.

[0059] In one embodiment, the detection device 200 is an integrated mask inspection system (IRIS).

[0060] In other words, this application utilizes the IRIS system built into the photolithography equipment as the detection device 200 to identify the test point 5. In this way, there is no need to set up an additional detection device or remove the protective film 4 for detection. That is, the damage detection of the protective film 4 can be realized inside the photolithography equipment. This not only reduces the cost of damage detection of the protective film 4, but also has high detection efficiency and can provide timely feedback and corresponding operations.

[0061] In some embodiments, the photomask 100 can be inspected by the IRIS system before the exposure operation. If the test point 5 is not detected, the exposure operation can be stopped to reduce the generation of defective wafers. After the photomask 100 is exposed, it can be inspected again by the IRIS system. If the test point 5 is not detected, the produced wafers can be intercepted in time and reworked, thus significantly reducing production losses.

[0062] In other words, the IRIS system can be used to detect the test point 5 before and after the exposure operation of the photomask 100, thus providing wafer production yield.

[0063] In one embodiment, the test point 5 is a protrusion protruding from the surface of the protective film 4.

[0064] This makes it convenient for the detection device 200 to detect the test point 5.

[0065] In one embodiment, the equivalent circle diameter of the protrusion is between 20 μm and 40 μm.

[0066] It should be noted that the shape of the convex point is spherical or irregular, and it can be treated as a sphere when calculating the diameter.

[0067] For example, the equivalent circle diameter of the convex point can be 20μm, 21μm, 22μm, 23μm, 24μm, 25μm, 26μm, 27μm, 28μm, 29μm, 30μm, 31μm, 32μm, 33μm, 34μm, 35μm, 36μm, 37μm, 38μm, 39μm or 40μm, etc.

[0068] It should be noted that the equivalent circle diameter of impurities such as particles is generally less than 20 μm, such as 2 μm to 18 μm.

[0069] Here, by setting an appropriate equivalent circle diameter, not only can impurities such as particles be distinguished, reducing misjudgments by the detection device 200, but also the occurrence of accidental damage can be reduced, further improving the reliability of the detection: when the equivalent circle diameter of the particle is smaller than that of the convex point, there is a significant order of magnitude difference in the back reflection light intensity and scattered light spot area between the two. The scattered light intensity and light spot size of small-sized particles are weak, and their signal amplitude is much lower than the standard characteristic threshold of the convex point. The detection device 200 can directly filter particle interference signals through preset size and light intensity thresholds, so that randomly falling environmental particles will not be misidentified as the test point 5, nor will the test point 5 be judged as damaged due to partial obstruction of the convex point by particles, significantly improving the detection accuracy.

[0070] To ensure detection effectiveness, particles must be prevented from completely covering the detection point. If the particle size is larger than the protrusion, it will completely obscure the optical contour of the protrusion when it falls on it, causing the detection device 200 to fail to capture the point's features and triggering a false alarm. However, when the equivalent diameter of the particle is smaller than the protrusion, the particle can only cover a local area of ​​the protrusion. The overall equivalent diameter and contour features of the protrusion remain within the detection and recognition threshold, allowing the detection device 200 to reliably identify the test point. This prevents detection failure due to routine dust accumulation in cleanrooms, improving the adaptability of the solution to the production environment. Furthermore, existing mask inspection systems in semiconductor production lines typically optimize optical resolution for 10μm-level defects, offering the highest signal-to-noise ratio for macroscopic features ranging from 20μm to 40μm. When particle sizes are generally smaller than the protrusion, the protrusion still possesses strong feature recognition even under background noise and small particle interference. The detection device 200 can quickly locate the coordinates of the test point and complete size matching without complex image denoising and feature extraction algorithms, improving both detection speed and coordinate comparison accuracy. Furthermore, when the particle diameter is smaller than the bump diameter, the raised structure of the bump can physically limit the free particles on the film surface, reducing the large-scale slippage of particles during the vibration of the photomask 100 and reducing the risk of repeated friction and scratching of the ultra-thin protective film by particles; conversely, large particles are more likely to cross the bump barrier and continuously scratch the film surface, accelerating the deterioration of the protective film.

[0071] In one embodiment, please refer to Figures 5 to 7 The bumps are formed by using a thread 300 with no more than four filaments to dip into glue 500, and then transferring the glue 500 to the protective film 4 for curing.

[0072] For example, the number of threads can be three or four.

[0073] The adhesive 500 can be a UV-curable adhesive. After the thread 300 is dipped in the UV-curable adhesive, it touches the protective film 4 to transfer the UV-curable adhesive onto the protective film 4. Then, the UV-curable adhesive on the protective film 4 can be cured by irradiating it with UV light to finally form bumps.

[0074] For example, the UV light irradiation time can be 1 minute.

[0075] In this way, by using a thread 300 of no more than four filaments to dip into glue 500 and drip it onto the protective film 4 for curing, not only can the equivalent circle diameter of the formed bumps be smaller, but damage to the protective film 4 can also be reduced, thereby extending the service life of the protective film 4.

[0076] In some embodiments, please refer to Figures 5 to 7 The thread 300 can be a knotless, single-strand, non-splitting velvet braided thread. After separating three or four strands, it is rejoined into a single strand. One end of the newly formed thread 300 is then fixed to the cloth tape 400, with the other end of the thread 300 protruding 1cm to 2cm. The cloth tape 400 can then be folded to form a handle for easy handling by the operator. The UV-curing adhesive can then be applied to the protective film 4 and touched to transfer the UV-curing adhesive to the protective film 4. Finally, the UV-curing adhesive on the protective film 4 is cured by UV light, ultimately forming raised dots.

[0077] In one embodiment, please refer to Figures 5 to 7 The raised dots are obtained by the following steps: take a strand of thread 300 with a length of no more than four filaments and twist it into a single strand; fix one end of the twisted thread 300 to the cloth tape 400 and fold the cloth tape 400; hold the folded cloth tape 400 and dip the other end of the twisted thread 300 into UV curing adhesive and bring it into contact with the protective film 4; use UV light to irradiate the UV curing adhesive for curing.

[0078] For example, the thread 300 can be a knotless single-strand non-splitting velvet braided thread, which is split into three or four strands and then rejoined into one strand. One end of the thread 300 can be fixed to the cloth tape 400, and the other end of the thread 300 can protrude 1cm to 2cm. Then, the cloth tape 400 is folded to form a handle for easy handling by the operator. Subsequently, the exposed part of the thread 300 is dipped into UV curing adhesive and brought into contact with the protective film 4 to transfer the UV curing adhesive onto the protective film 4. Finally, the UV curing adhesive on the protective film 4 is cured by UV light, and the raised dots are formed.

[0079] In some embodiments, the bumps can also be formed by selecting inorganic nanoparticles, preparing them into a suspension solution, and then fixing them onto the protective film 4 to form bumps.

[0080] This application also provides a detection method, applied to the lithography equipment in any of the above embodiments. Please refer to... Figure 8 The detection methods include: S1. The detection device scans the surrounding area to detect the point to be tested; S2. If the test point is not detected, the protective film is determined to be damaged; if the test point is detected, the protective film is determined to be undamaged.

[0081] For example, the detection device 200 can scan the peripheral area 42 to detect the test point 5 in the following ways: by image recognition, for example, when the photomask 100 is used for the first time, an image can be scanned at the location of the test point 5, and then another image can be scanned before each exposure operation. By comparison, it can be determined whether the test point 5 has been identified; or the coordinate position, shape or size parameters can be obtained by the emission and reflection of the light path, and then the parameters can be checked to confirm the identification.

[0082] For example, the scanning operation of the peripheral area 42 by the detection device 200 can be performed before or after each exposure operation, or both before and after each exposure operation.

[0083] The detection method provided in this application uses a detection device 200 to scan the peripheral area 42 to detect the test point 5. This allows the presence or absence of the test point 5 to be used as a criterion for judging whether the protective film 4 is damaged. Thus, during detection, only the test point 5 needs to be detected and identified. This not only improves the reliability of the detection but also improves the detection efficiency to a certain extent.

[0084] In one embodiment, step S1, scanning the peripheral area using the detection device to detect the point to be tested, includes: S11. Mark the location of the point to be measured as a feature location, and the detection device scans the feature location to obtain real-time coordinates and corresponding real-time size parameters; S12. Based on the real-time coordinates and the real-time size parameters, and the initial coordinates and corresponding initial size parameters of the point to be measured, determine whether a match is found. S13. If the real-time coordinates and the real-time size parameters do not match the initial coordinates and the initial size parameters, it is determined that the point to be measured has not been identified. If the real-time coordinates and the real-time size parameters match the initial coordinates and the initial size parameters, it is determined that the point to be measured has been identified.

[0085] For example, the detection device 200 can be an IRIS system.

[0086] Dimensional parameters include the equivalent circle diameter, length, or width, etc.

[0087] Initial coordinates and initial size parameters refer to the coordinates and corresponding size parameters of the point to be measured 5 when the photomask 100 is used for the first time.

[0088] For example, the initial coordinates and initial size parameters of the point to be measured 5 can be obtained by the detection device 200.

[0089] The location of the test point 5 is marked as a feature location. It can be marked when the initial coordinates and initial size parameters of the test point 5 are obtained, such as by the detection device 200.

[0090] For example, determining whether a match is found based on the real-time coordinates and the real-time size parameters and the initial coordinates and corresponding initial size parameters of the point to be measured can be as follows: the obtained real-time coordinates are the same as the initial coordinates, the real-time size parameters are the same as the initial size parameters, or the real-time coordinates and the initial coordinates and the real-time size parameters are within a certain error range.

[0091] Here, by determining whether the real-time coordinates and real-time size parameters scanned by the detection device 200 match the initial coordinates and initial size parameters of the point to be measured 5, it can be determined whether the detection device 200 has identified the point to be measured 5. In this way, the judgment condition is accurate and reliable, which can reduce the occurrence of misjudgment.

[0092] In some embodiments, the photolithography equipment includes a control system, which is communicatively connected to the detection device 200, and the detection method includes: The control system acquires and stores the initial coordinates and initial size parameters of all test points 5, and controls the detection device 200 to mark the feature positions; Before each exposure operation, the control system controls the detection device 200 to scan the marked feature positions. Then, the detection device 200 sends the acquired real-time coordinates and real-time size parameters to the control system. Finally, the control system determines whether the real-time coordinates and real-time size parameters of each marked feature position are repeated with the initial coordinates and initial size parameters. If there is a non-repetition, it means that the feature position of the mark has failed to match, and then it is determined that the feature position has broken. The control system issues an alarm and intercepts the photomask 100.

[0093] In this way, before each exposure operation, the detection device 200 can be automatically scanned by the control system to determine whether the test point 5 has cracked and / or changed position, resulting in high detection efficiency.

[0094] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, and improvements made within the spirit and scope of this application are included within the scope of protection of this application.

Claims

1. A photomask, characterized in that, include: substrate; A frame is fixedly mounted on the substrate, and an opening is formed on the side of the frame facing away from the substrate. A patterned area is located within the frame and disposed on the surface of the substrate; A protective film covers the opening. The protective film includes a working area and a peripheral area. The peripheral area surrounds the outer periphery of the working area and is adhered to the end face of the frame with the opening. The surface of the peripheral area facing away from the frame has test points.

2. The photomask according to claim 1, characterized in that, The number of test points is multiple, and the multiple test points are arranged at intervals along the circumference of the protective film.

3. The photomask according to claim 2, characterized in that, The interval between two adjacent test points is between 10mm and 25mm.

4. The photomask according to claim 1, characterized in that, The dimension between the test point and the inner surface of the frame is less than 1 mm.

5. The photomask according to claim 1, characterized in that, The test point is a protrusion that protrudes from the surface of the protective film.

6. The photomask according to claim 5, characterized in that, The equivalent circle diameter of the protrusion is between 20 μm and 40 μm.

7. The photomask according to claim 5 or 6, characterized in that, The convex point is obtained using the following steps: Take a strand of silk thread no larger than four mils and twist it into a ply; One end of the stranded filaments is fixed to the fabric tape, and the fabric tape is folded. Holding the folded cloth tape, dip the other end of the stranded filaments into UV-curable adhesive and bring it into contact with the protective film; The UV-curable adhesive is cured by irradiating it with UV light.

8. A photolithography apparatus, characterized in that, It includes a detection device and a photomask as described in any one of claims 1 to 7, wherein the detection device is used to identify the point to be tested.

9. The photolithography apparatus according to claim 8, characterized in that, The detection device includes a beam emitter and a detector. The beam emitter is configured to emit a detection beam toward the peripheral region, and the detector is used to receive the detection beam reflected by the point to be tested.

10. The photolithography apparatus according to claim 8, characterized in that, The detection device is an integrated mask detection system.

11. A detection method, applied to the photolithography apparatus according to any one of claims 8 to 10, characterized in that, The detection method includes: The detection device scans the surrounding area to detect the point to be tested. If the test point is not detected, the protective film is determined to be damaged; if the test point is detected, the protective film is determined to be intact.

12. The detection method according to claim 11, characterized in that, The step of scanning the peripheral area using the detection device to detect the point to be tested includes: The location of the point to be measured is marked as a feature location, and the detection device scans the feature location to obtain real-time coordinates and corresponding real-time size parameters; Based on the real-time coordinates and real-time size parameters, and the initial coordinates and corresponding initial size parameters of the point to be measured, determine whether they match; If the real-time coordinates and the real-time size parameters do not match the initial coordinates and the initial size parameters, it is determined that the point to be measured has not been detected. If the real-time coordinates and the real-time size parameters match the initial coordinates and the initial size parameters, it is determined that the point to be measured has been detected.

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