Chromium plate photomask cleaning apparatus

Abstract

This application discloses a chromium plate photomask cleaning device. The chromium plate photomask cleaning device includes a vacuum cleaning chamber, a photomask supporting mechanism, a light emitting mechanism, and a residue collection mechanism. The vacuum cleaning chamber allows the chromium plate photomask to enter and exit, and remains sealed during the cleaning process. The photomask supporting mechanism is located within the vacuum cleaning chamber and is used to fix the chromium plate photomask. The light emitting mechanism emits light rays that dissolve residues on the chromium plate photomask; the light rays are reflected by the chromium layer and substrate mirror of the chromium plate photomask. The residue collection mechanism communicates with the interior of the vacuum cleaning chamber and collects the dissolved residues. Therefore, the chromium plate photomask cleaning device can effectively clean photoresist and other residues without damaging the chromium layer and quartz substrate of the chromium plate photomask, and also offers high cleaning efficiency.

Description

Technical Field

[0001] This application belongs to the field of semiconductor technology, and specifically relates to a chromium plate photomask cleaning device. Background Technology

[0002] As the core template in semiconductor photolithography, the surface quality of a photomask directly determines the precision and yield of chip manufacturing. A chromium plate photomask, as a type of photomask, consists of a quartz substrate and a chromium-plated surface layer. Chromium plate photomasks form intricate circuit patterns through processes such as photoresist patterning and etching. After the photomask is manufactured or used, residual photoresist and other materials may remain on the surface. These residues can cause distortion in the transfer of the photolithographic pattern, therefore efficient cleaning is essential. Summary of the Invention

[0003] The purpose of this application is to overcome the shortcomings of the prior art and provide a chromium plate photomask cleaning device that can effectively clean chromium plate photomasks without damaging the chromium layer and quartz substrate of the chromium plate photomask.

[0004] To achieve the above objectives, the technical solution adopted in this application is as follows:

[0005] A chromium plate photomask cleaning device includes a vacuum cleaning chamber, a photomask supporting mechanism, a light emitting mechanism, and a residue collection mechanism. The vacuum cleaning chamber allows the chromium plate photomask to enter and exit, and remains sealed during the cleaning process. The photomask supporting mechanism is located within the vacuum cleaning chamber and is used to fix the chromium plate photomask. The light emitting mechanism emits light rays that dissolve residues on the chromium plate photomask; the light rays are reflected by the chromium layer and the substrate mirror surface of the chromium plate photomask. The residue collection mechanism communicates with the interior of the vacuum cleaning chamber and collects the dissolved residues.

[0006] In some embodiments, the chromium layer and the substrate have a reflectivity of not less than 90% for the light to achieve the specular reflection.

[0007] In some embodiments, the light emitting mechanism is a molecular laser emitting mechanism, an excimer laser, an infrared / visible solid-state laser, or a mid-infrared fiber laser.

[0008] In some embodiments, the chromium plate photomask cleaning device includes an anti-reflective coating covering a first region and a second region of the inner wall of the vacuum cleaning chamber. The anti-reflective coating in the first region absorbs light emitted by the light emitting mechanism, and the anti-reflective coating in the second region absorbs light reflected by the chromium plate photomask.

[0009] In some embodiments, the photomask support mechanism includes a support platform and a vacuum adsorption assembly, wherein the support platform is provided with adsorption holes; the vacuum adsorption assembly is in communication with all of the adsorption holes; and the vacuum adsorption assembly adsorbs the chromium plate photomask onto the support platform through the adsorption holes.

[0010] In some embodiments, the chromium plate photomask cleaning device includes a plurality of positioning pins disposed on the support platform and distributed circumferentially along the chromium plate photomask to limit the chromium plate photomask.

[0011] In some embodiments, the chromium plate photomask cleaning device includes a cleaning area positioning mechanism and a control system. The cleaning area positioning mechanism obtains the coordinates of the cleaning area of ​​the chromium plate photomask. The control system controls the light emitted by the light emitting mechanism to be directed toward the cleaning area according to the coordinates.

[0012] In some embodiments, the light emitting mechanism includes a light generating component and a light scanning component. The light generating component generates light rays. The light scanning component is connected to the control system and includes a two-dimensional moving platform. Under the control of the control system and the action of the two-dimensional moving platform, the light generating component moves along at least one of the transverse and longitudinal directions of the partition photomask according to the coordinates, so that the light rays generated by the light generating component are directed toward the area to be cleaned.

[0013] In some embodiments, the area to be cleaned positioning mechanism includes a visual positioning mechanism, including a lens facing the photomask carrying mechanism to image the chromium plate photomask.

[0014] In some embodiments, the optical scanning component includes an energy monitoring component connected to the control system. When the monitored value of the energy monitoring component is greater than a preset value, the control system reduces the energy of the light emitted by the light generating component; when the monitored value is less than the preset value, the control system increases the energy of the light emitted by the light generating component.

[0015] In some embodiments, the chromium plate photomask cleaning equipment includes a temperature sensing device; the temperature sensing device obtains the temperature of the area to be cleaned; the control system controls the energy of the light emitted by the light emitting mechanism and / or controls the speed of the light scanning component moving laterally and longitudinally based on the temperature of the area to be cleaned.

[0016] In some embodiments, the vacuum cleaning chamber includes a residue outlet; the chromium plate photomask cleaning device includes a control system; the residue collection mechanism includes a vacuum extraction component, a filter component, and a residue collector; the filter component is connected to the residue outlet and the residue collector; the vacuum extraction component is connected to the filter component and also to the control system, under the control of the control system and the action of the vacuum extraction component, the cleaned residue is filtered by the filter component, the gas is discharged through the vacuum extraction component, and the residue is discharged into the residue collector.

[0017] This application has the following advantages compared with the prior art:

[0018] Because the light emitted by the light-emitting mechanism can be absorbed by residues such as photoresist, the photoresist and other residues are cleaned away. Furthermore, the chromium layer and quartz substrate of the chromium plate photomask exhibit extremely low absorption and high reflectivity for this wavelength of laser light through specular reflection, absorbing almost no laser energy and resulting in no significant increase in surface temperature. Therefore, the substrate will not suffer melting, cracking, or other damage, and the surface roughness of the substrate remains unchanged, meeting the requirements for semiconductor photolithography processes. Moreover, the selective cleaning of photoresist and other residues described above also has at least the following advantages:

[0019] 1) High cleaning efficiency: Photoresist (organic material) strongly absorbs light, and light energy is quickly converted into heat energy, which vaporizes and decomposes the photoresist into small molecule residues. This achieves the vaporization and decomposition of photoresist and other residues without the need for chemical reagent soaking and subsequent drying processes. It can also be used to clean specific areas, greatly improving cleaning efficiency.

[0020] 2) Environmental protection and safety: The vacuum cleaning environment is used, no chemical reagents are used, avoiding the toxic pollution of organic solvents. The residue can be collected and treated in a centralized manner, which is green and environmentally friendly.

[0021] 3) High degree of automation: The control system enables collaborative work among various mechanisms, automatically matching cleaning parameters, reducing manual intervention, and improving cleaning stability and consistency.

[0022] 4) Cleaning of photoresist and other residues is carried out in a vacuum cleaning chamber. Under vacuum conditions, the vaporized photoresist residue is collected in time by the residue collection mechanism to avoid secondary contamination of the chromium plate photomask. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the chromium plate photomask cleaning device of this application at one angle;

[0024] Figure 2 This is a schematic diagram of the chromium plate photomask cleaning equipment of this application from another angle. Detailed Implementation

[0025] To illustrate the technical content, structural features, achieved objectives, and effects of the invention in detail, the technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. In the following description, for illustrative purposes, numerous specific details are set forth to provide a detailed description of various exemplary embodiments or implementations of the invention. However, various exemplary embodiments can also be implemented independently without these specific details or in one or more equivalent arrangements. Furthermore, the various exemplary embodiments may differ, but are not necessarily exclusive. For example, without departing from the inventive concept, the specific shape, structure, and characteristics of the exemplary embodiments may be used or implemented in another exemplary embodiment.

[0026] See Figure 1 and Figure 2 This application discloses a chromium plate photomask cleaning device. The chromium plate photomask cleaning device 10 includes a vacuum cleaning chamber 1, a photomask carrying mechanism 2, a light emitting mechanism 3, and a residue collection mechanism 4. The vacuum cleaning chamber 1 allows the chromium plate photomask 20 to enter and exit, and is in a sealed state during the cleaning process. In some embodiments, the vacuum cleaning chamber 1 is a cuboid cavity with an air inlet 11, a residue outlet 12, and a photomask inlet / outlet. A sealing door 13 is installed at the photomask inlet / outlet. Opening the sealing door 13 allows the chromium plate photomask to be placed on the photomask carrying mechanism 2. The sealing door 13 can be closed under the control of the control system 5. With the sealed door 13 closed, connected to the air inlet 11 and the nitrogen input device 9, and the residue outlet 12 connected to the residue collection mechanism 4, the vacuum cleaning chamber 1 is in a sealed state. At this time, the control system 5 activates the residue collection mechanism 4 to evacuate the vacuum cleaning chamber 1, bringing the vacuum level inside the chamber to a preset value, thus transforming the aforementioned chamber into the vacuum cleaning chamber 1. After the chromium plate photomask cleaning is completed, the nitrogen input device 9 inputs nitrogen into the vacuum cleaning chamber 1 through the air inlet 11, restoring the pressure inside the vacuum cleaning chamber 1 to normal. After restoring to normal pressure, the sealed door 13 is opened, and the cleaned chromium plate photomask can be removed. The contaminants (vaporized photoresist and residue, etc.) generated during the cleaning of the chromium plate photomask are collected by the residue collection device 4 through the residue outlet 12. As can be seen from the general process of cleaning the chromium plate photomask described above, the sealing door 13 closes the photomask inlet and outlet, the air inlet 11 is connected to the nitrogen input device 9, and the residue outlet 12 is connected to the residue collection mechanism 4. Thus, during the cleaning of the chromium plate photomask, the vacuum cleaning chamber 1 is in a sealed state.

[0027] The photomask support mechanism 2 is located within the vacuum cleaning chamber 1 and is used to fix the chromium plate photomask. Based on the aforementioned function of the photomask support mechanism 2, its structure is not limited, as long as it can keep the chromium plate photomask stationary during the cleaning process. Typically, the photomask support mechanism 2 includes a support platform 21. The chromium plate photomask 20 is located on the support platform 21. To easily distinguish between the chromium plate photomask 20 and the photomask support mechanism 2, Figure 2 In the diagram, the chromium plate photomask 20 is represented by a dashed line.

[0028] The light emitting mechanism 3 is used to emit light that dissolves residues on the chromium plate photomask 20. These residues typically include photoresist. The light is specularly reflected by the chromium layer and substrate of the chromium plate photomask 20. In some embodiments, the reflectivity of the chromium layer and substrate to the light is not less than 90% to achieve specular reflection. In one embodiment of this application, the light emitting mechanism 3 is a molecular laser emitting mechanism, for example, a CO2 laser emitting mechanism. The CO2 laser emitting mechanism operates in a CO2 + N2 + He mixed gas medium and can output infrared laser light with a wavelength of approximately 10.6 μm.

[0029] As described above, the light emitted by the light emitting mechanism 3 can be absorbed by photoresist and other residues, thus cleaning them away. Furthermore, the chromium layer and quartz substrate of the chromium plate photomask exhibit extremely low absorption and high reflectivity for this wavelength of laser light through specular reflection, absorbing almost no laser energy and resulting in no significant increase in surface temperature. Therefore, the substrate will not suffer melting, cracking, or other damage, and the surface roughness of the substrate remains unchanged, meeting the requirements for semiconductor photolithography processes. Moreover, selectively cleaning away photoresist and other residues also offers at least the following advantages:

[0030] 1) High cleaning efficiency: Photoresist (organic material) strongly absorbs light, and light energy is quickly converted into heat energy, causing the photoresist to vaporize and decompose into small molecule residues instantly. This achieves the vaporization and decomposition of photoresist and other residues without the need for chemical reagent soaking and subsequent drying processes. It can also be used to clean specific areas, greatly improving cleaning efficiency.

[0031] 2) Environmental protection and safety: The vacuum cleaning environment is used, no chemical reagents are used, avoiding the toxic pollution of organic solvents. The residue can be collected and treated in a centralized manner, which is green and environmentally friendly.

[0032] 3) High degree of automation: The control system enables collaborative work among various mechanisms, automatically matching cleaning parameters, reducing manual intervention, and improving cleaning stability and consistency.

[0033] 4) Cleaning of photoresist and other residues is carried out in the vacuum cleaning chamber 1. Under vacuum conditions, the vaporized residue of the photoresist is collected in time by the residue collection mechanism 4 to avoid secondary contamination of the chromium plate photomask 20.

[0034] The light emitted by the light-emitting mechanism 3 has the following effects: photoresist and other residues strongly absorb the light and are dissolved, while the chromium layer of the chromium plate photomask and the quartz substrate reflect the light specularly. Based on this effect, in some embodiments, the light-emitting mechanism 3 can also be an excimer laser, such as a KrF excimer laser with a wavelength of 248 nm or an ArF excimer laser with a wavelength of 193 nm. The chromium layer and the quartz substrate still have very low absorption for light with wavelengths of 193 / 248 nm, but the photoresist can be dissolved by light with wavelengths of 193 / 248 nm. For example, the light-emitting mechanism 3 can be an infrared / visible solid-state laser, such as a Q-switched solid-state infrared laser. The working medium of the Q-switched solid-state infrared laser is a neodymium-doped yttrium aluminum garnet (Nd:YAG) crystal, and high peak power pulse output with wavelengths of 1064 nm / 532 nm is achieved through electro-optic Q-switching or acousto-optic Q-switching. Photoresist is an organic polymer with strong absorption at both 1064nm and 532nm. After absorbing laser energy, it rapidly heats up, vaporizes, and decomposes into small-molecule waste gas. The chromium layer of the chromium plate photomask 20 and the quartz substrate exhibit high reflectivity and low absorption characteristics for this wavelength of laser. The laser mainly undergoes specular reflection and is hardly absorbed, thus avoiding significant temperature rise, melting, or cracking damage. The light emitting mechanism 3 can also be a mid-infrared fiber laser, such as a fiber laser with wavelengths of 1.5μm or 2μm. The C–H and O–H bonds in the photoresist have strong resonant absorption in this wavelength band, resulting in efficient decomposition; the absorption of the quartz substrate and chromium layer of the chromium plate photomask remains very low.

[0035] In comparison, the optical emitting mechanism 3, being a CO2 laser emitting mechanism, has the following advantages:

[0036] 1) Because the wavelength of CO2 laser is in the mid-infrared band, organic photoresist has a strong resonant absorption characteristic, so the removal efficiency of photoresist is higher and the cleaning speed is faster.

[0037] 2) Because CO2 lasers have extremely low absorption on chromium layers and quartz substrates and significant specular reflection effects, the thermal effects are more concentrated on contaminants attached to the surface of the chromium plate photomask. Therefore, the thermal impact on nanoscale photomask patterns is smaller, resulting in higher reliability without damage.

[0038] 3) Because CO2 lasers have high output power and good energy uniformity, they are more suitable for scanning and cleaning larger areas and have a wider range of applications.

[0039] 4) Because the area affected by the CO2 laser beam is relatively mild and does not easily produce photochemical effects or high-energy ionization in the ultraviolet band, it will not cause potential damage to the chemical bond level of the chromium plate photomask.

[0040] In some embodiments, the chromium plate photomask cleaning device includes an anti-reflective coating 14 covering a first region and a second region of the inner wall of the vacuum cleaning chamber. The anti-reflective coating in the first region absorbs light emitted by the light emitting mechanism, and the anti-reflective coating in the second region absorbs light reflected by the chromium plate photomask. Figure 1 and Figure 2 The diagram illustrates that the anti-reflective coating 14 covers all the inner walls of the vacuum cleaning chamber 1; however, those skilled in the art will understand that it is sufficient to cover only the first and second areas.

[0041] As described above, since the anti-reflective coating 14 covers the first and second regions, all light rays except those used for cleaning the chrome plate photomask 20 can be absorbed by the anti-reflective coating 14, thus avoiding damage to the chrome plate photomask 20 from unnecessary light rays. For example, unnecessary light rays reflected in the vacuum cleaning chamber 1 can cause local energy concentration and damage to the chrome plate photomask 20.

[0042] See Figure 2 and combined Figure 1 The photomask support mechanism 2 includes a support platform 21 and a vacuum adsorption assembly 22. The support platform 21 has adsorption holes 211 distributed on it. The vacuum adsorption assembly 22 is connected to all the adsorption holes 211, for example, through a connecting pipe 221. The vacuum adsorption assembly 22 adsorbs the chromium plate photomask onto the support platform through the adsorption holes. Based on the functions of the adsorption holes 211 and the vacuum adsorption assembly 22, those skilled in the art will understand that the adsorption holes 211 can be evenly distributed or unevenly distributed, as long as they can adsorb and fix the chromium plate photomask 20 onto the support platform 21 under the action of the vacuum adsorption assembly 22. In this embodiment, the vacuum adsorption assembly 22 can operate under the control of the control system 5 or under the control of other control systems.

[0043] As described above, by cooperating with the vacuum adsorption component 22 and the adsorption hole 211, the chromium plate photomask 20 is fixed on the support stage 21, which has at least the following advantages:

[0044] 1) Because the vacuum adsorption fixation method eliminates mechanical clamping stress, it avoids pressure damage and warping deformation of the chromium plate photomask edges, ensuring nanoscale pattern accuracy.

[0045] 2) Because vacuum adsorption achieves fixation only through negative gas pressure and does not use fixtures, pressure blocks or other structures, it will not block the area to be cleaned on the surface of the chrome plate photomask 20, making it easy for light to fully cover the area to be cleaned and ensuring good cleaning effect.

[0046] 3) Because vacuum adsorption can flatten and adhere the chromium plate photomask to the support stage 21, it can ensure that the mask surface height is consistent and the light focusing position is stable, avoiding uneven cleaning or damage to the substrate due to surface undulations.

[0047] 4) Because vacuum adsorption in the vacuum cleaning chamber 1 is compatible with the overall vacuum environment and does not require an additional sealing structure, it is beneficial to maintain the vacuum level in the vacuum cleaning chamber 1, simplify the equipment structure and improve the system sealing performance.

[0048] 5) Because vacuum adsorption is a non-contact rigid fixation method, it allows for quick assembly and disassembly without generating frictional debris, thus avoiding particulate contamination caused by mechanical clamping and improving the photomask cleaning yield.

[0049] 6) Because vacuum adsorption can quickly and stably position and fix the chromium plate photomask 20, it can improve the loading and unloading efficiency, and at the same time prevent the chromium plate photomask 20 from shifting during the cleaning process, which makes the control of the light movement path simpler.

[0050] See Figure 1 and Figure 2 The chromium plate photomask cleaning device includes multiple positioning pins 23, which are disposed on the support platform 21 and distributed circumferentially along the chromium plate photomask 20 to limit the chromium plate photomask 20. In some embodiments, the area enclosed by the multiple positioning pins 23 at intervals is slightly larger than the area of ​​the chromium plate photomask 20, thereby achieving the purpose of positioning the chromium plate photomask 20. Based on the above-mentioned function of the positioning pins 20, the specific number of positioning pins 23 is not limited. Figure 1 The diagram illustrates four positioning pins 23, which are respectively positioned at the four corners of the support platform 21. The positioning pins 23 can be stationary relative to the support platform 21, thus allowing the chrome plate photomask cleaning device to clean only one size of chrome plate photomask 20. In other embodiments, the positioning pins 23 can be movable relative to the support platform 21. This allows the positioning pins 23 to be moved to create areas of different sizes, which can accommodate chrome plate photomasks 20 of different sizes, enabling the chrome plate photomask cleaning device to clean chrome plate photomasks 20 of various sizes.

[0051] As described above, by setting the positioning pins 23 and distributing them as described above to limit the placement of the chromium plate photomask 20, at least the following advantages are achieved:

[0052] 1) It facilitates the placement of the chrome plate photomask, which helps improve the cleaning efficiency of the chrome plate photomask 20;

[0053] 2) By limiting the position, it helps to prevent the chrome plate photomask 20 from shifting or tilting when it is placed, which helps to ensure that the light is aligned with the area to be cleaned during the cleaning process.

[0054] 3) Because the positioning pins 23 are distributed along the circumference of the chromium plate photomask 20, they do not rigidly press the chromium plate photomask 20, so they will not generate mechanical stress on the edge of the chromium plate photomask 20, thus preventing edge chipping, cracking or internal stress deformation.

[0055] Of course, combining the above method with vacuum adsorption of the chromium plate photomask 20 onto the support stage 20 can better fix the chromium plate photomask 20 onto the support stage 21.

[0056] See Figure 2 The chromium plate photomask cleaning equipment includes a control system 5 and a cleaning area positioning mechanism 6. The cleaning area positioning mechanism 6 obtains the coordinates of the area to be cleaned on the chromium plate photomask 20. The control system 5, based on the coordinates, controls the light emitted by the light emitting mechanism 3 to be directed towards the cleaning area. For example, it controls the power, pulse frequency, moving speed (scanning speed), or spot diameter of the light emitted by the light emitting mechanism 3. The structure of the cleaning area positioning mechanism 6 is not limited; it only needs to be able to determine which areas on the chromium plate photomask 20 are the areas to be cleaned based on the coordinates.

[0057] As described above, the coordinates are obtained through the positioning mechanism 6 of the area to be cleaned, and the control system 5 then controls the light emitted by the light emitting mechanism 3 to be directed toward the area to be cleaned based on the coordinates. This has at least the following advantages:

[0058] 1) Because the coordinates of the area to be cleaned are automatically obtained through the area positioning mechanism 6, there is no need for manual searching of the area to be cleaned, thus greatly improving cleaning efficiency and reducing human error.

[0059] 2) Because the control system uses precise coordinates to direct the light to the area to be cleaned, it achieves targeted cleaning and avoids the light from shining on the normal graphic area, thus protecting the chrome plate photomask 20.

[0060] 3) Because the light only illuminates the area to be cleaned rather than scanning the entire area, and because the coordinates obtained by the area-to-be-cleaned positioning mechanism 6 and the light emitted by the light emitting mechanism 3 form a closed-loop linkage, the above-mentioned settings reduce the light exposure time, lower energy consumption, improve the overall equipment operating safety, and increase the efficiency of cleaning the chromium plate photomask 20. Furthermore, the aforementioned linkage enables precise positioning and selective irradiation of the area to be cleaned, effectively avoiding heat accumulation caused by ineffective irradiation, and further ensuring the structural integrity of the chromium layer and the quartz substrate.

[0061] 4) Because coordinate control can achieve fine cleaning of tiny residual areas, it can better meet the high cleaning requirements of chrome plate photomask 20.

[0062] In some embodiments, the area to be cleaned positioning mechanism 6 includes a visual positioning mechanism, including a lens facing the photomask carrying mechanism to image the chromium plate photomask 20.

[0063] As described above, obtaining images through a visual positioning mechanism, and thus obtaining the coordinates of the area to be cleaned, has at least the following advantages:

[0064] 1) Because the lens directly images the chromium plate photomask 20 on the photomask carrier mechanism, it can obtain a clear real-time image of the surface of the chromium plate photomask 20, providing a reliable basis for identifying the area to be cleaned.

[0065] 2) Because a visual positioning mechanism is used and the lens is oriented toward the support stage 21, non-contact inspection can be achieved, and the surface of the high-precision chrome plate photomask 20 will not be scratched or contaminated.

[0066] 3) Because the lens is directly facing the photomask, the shooting angle is stable and unobstructed, so the positioning accuracy is high and the area to be cleaned can be accurately identified.

[0067] 4) Because the lens enables visual imaging, it can directly obtain the coordinate information of the area to be cleaned, and thus quickly transmit the location data to the control system, achieving efficient linkage between positioning and laser cleaning. The positioning method provides intuitive imaging and comprehensive recognition range, so it can not only locate residual areas, but also assist in checking the cleaning effect and improve the overall process reliability.

[0068] See Figure 2In some embodiments, the light emitting mechanism 3 includes a light generating component 31 and a light scanning component 32. The light generating component 31 generates light, and its structure is not limited. For example, in this application, the light generating component 31 includes a CO2 laser 311, a power regulator 312, and a collimator 313. The CO2 laser 311 is a pulsed CO2 laser that can emit laser light with a wavelength of 10.6 μm and a pulse frequency of 1-10 kHz. The power regulator 312 is electrically connected to the CO2 laser 311 and can adjust the laser power to 0.5-5W. This energy is only enough to vaporize and decompose the photoresist, which is below the melting threshold of the chromium layer and the cracking threshold of the quartz substrate. The collimator 313 is disposed at the light output port of the CO2 laser 311 and is used to calibrate the laser beam into a parallel beam. The light scanning component 32 is connected to the control system 5. In this embodiment, the light scanning component 32 corresponds to the laser incident direction of the light generating component 31 and includes a two-dimensional moving platform 321. In some embodiments, the two-dimensional moving platform 321 is a precision electric translation stage with a moving accuracy of 0.01 mm, which can drive the light generating component 31 to move along the X-axis and Y-axis. The X-axis and Y-axis can be the horizontal and vertical axes of the chromium plate photomask 20. In some embodiments, the light scanning component 32 includes a focusing lens 322. The focusing lens 322 has a focal length of 100 mm, which can focus the laser beam into a beam with a spot diameter of 0.1-1 mm, improving the local energy density and ensuring sufficient decomposition of the photoresist. In some cases where focusing is not required, the light scanning component 32 may not include the focusing lens 322. Under the control of the control system 5 and the action of the two-dimensional moving platform 321, the light scanning component 32 and the light generating component 31 move together along at least one of the horizontal and vertical axes of the chromium plate photomask according to the coordinates, so that the light generated by the light generating component 3 is directed towards the area to be cleaned.

[0069] As described above, under the action of the two-dimensional moving platform 321 and the control system 5, the two-dimensional moving platform 321 can drive the light generating component 31 to move to the corresponding position according to the coordinates, so that the light generated by the light generating component 31 is directed towards the area to be cleaned. In this way, the positioning of the area to be cleaned by the positioning mechanism and the two-dimensional precise scanning of the two-dimensional moving platform can achieve the cleaning of the nanometer-level high-precision chromium plate photomask 20, meeting the high-precision requirements of semiconductor manufacturing. This method, combined with the fact that the diameter of the light spot emitted by the light emitting component 3 can be precisely adjusted to 0.1-1mm, further meets the high-precision requirements.

[0070] See Figure 2The optical scanning component 32 includes an energy monitoring component 323. The energy monitoring component 323 is connected to the control system 5. When the monitored value of the energy monitoring component 323 is greater than a preset value, the control system 5 reduces the energy of the light emitted by the light generating component 31; when the monitored value is less than the preset value, it increases the energy of the light emitted by the light generating component 31. In this embodiment, the control system 5 controls the power regulator 312 to reduce the output power, thereby reducing the energy of the emitted light; and controls the power regulator 312 to increase the output power, thereby increasing the energy of the light emitted by the light generating component 31.

[0071] As described above, through the interaction between the control system 5, the light monitoring component 323, and the light generating component 31, the energy monitoring component 323 monitors the laser output energy in real time. If the energy deviates from the set value, the control system 5 adjusts the power regulator 323 for correction. Ultimately, this has at least the following advantages:

[0072] 1) Because the energy monitoring component 323 monitors the energy output of the light generating component 31 in real time, it can detect abnormalities such as laser power fluctuations and attenuation in a timely manner, ensuring that the cleaning energy is stable and reliable. For example, the energy is stable near the preset value, ensuring that the laser energy can only vaporize and decompose the photoresist, and is below the melting threshold of the chromium layer and the cracking threshold of the quartz substrate.

[0073] 2) Because the control system can automatically adjust the power regulator 323 to correct when the energy deviates from the set value, it can avoid incomplete cleaning of photoresist and other residues due to low power, and can also prevent damage to the chromium plate photomask 20 due to excessive power.

[0074] 3) Because the closed-loop feedback control of energy is achieved through the light monitoring component 323, the control system 5 and the light generation component 31, the cleaning effect of different products in the same batch is more consistent, which is conducive to improving yield and stability.

[0075] 4) Because energy anomalies can be corrected in real time without the need for manual adjustment during shutdown, the automation level and continuous working capability of the equipment are improved.

[0076] 5) Because the laser energy is monitored and corrected throughout the process by the optical monitoring component 323, local overheating, overburning or missed cleaning caused by unstable energy can be effectively avoided, ensuring mask safety and cleaning quality.

[0077] See Figure 1 and Figure 2The chromium plate photomask cleaning equipment includes a temperature sensing device 24; the temperature sensing device 24 obtains the temperature of the area to be cleaned. Based on the function of the temperature sensing device 24, its structure is not limited; for example, the temperature sensing device 24 can be a temperature sensor, a thermal imager, etc. The control system 5 controls the energy of the light emitted by the light emitting mechanism 3 according to the temperature of the area to be cleaned; or, controls the speed of the light scanning component 32 in the horizontal and vertical directions, thereby ensuring that the temperature of the chromium plate photomask 20 does not exceed a preset value. In some embodiments, the aforementioned control stabilizes the temperature of the chromium plate photomask near a certain preset value. Of course, in other embodiments, both the energy of the light emitted by the light emitting mechanism 3 and the speed of the light scanning component 32 in the horizontal and vertical directions can be controlled. See also Figure 1 and Figure 2 In some embodiments, the temperature sensing device 24 is mounted on one side of the support stage 21, with its probe facing the surface of the chromium plate photomask 20 to monitor the temperature in real time. In other embodiments, the temperature sensing device 24 (such as the aforementioned thermal imager) is movable relative to the support stage 21, so that the temperature of the area to be cleaned on the chromium plate photomask 20 of different sizes can be measured.

[0078] As described above, the temperature of the area to be cleaned is sensed by the temperature sensing device 23, thereby controlling the energy of the light emitting mechanism 3 and the scanning speed of the light scanning component 32. This provides at least the following advantages:

[0079] 1) Because the temperature of the area to be cleaned is monitored in real time by the temperature sensing device 24, the real-time thermal state of the photoresist and photomask surface can be accurately grasped, thus avoiding temperature runaway.

[0080] 2) Because the temperature data is acquired in real time and fed back to the control system 5, the laser power or scanning speed can be adjusted in time to prevent the chromium layer of the chromium plate photomask from melting and the quartz substrate from cracking due to excessive temperature.

[0081] 3) Because temperature monitoring can reflect whether the photoresist has been effectively heated and vaporized, it can determine whether the cleaning process is normal and avoid insufficient cleaning or excessive irradiation.

[0082] 4) Because closed-loop temperature control is achieved, the cleaning process is always kept within a safe temperature range, which greatly improves the safety and reliability of photomasks in laser cleaning.

[0083] 5) Because the system can respond quickly when the temperature is abnormal, it can effectively avoid precision damage such as pattern deformation and film peeling caused by heat accumulation.

[0084] See Figure 1 and Figure 2The vacuum cleaning chamber 1 includes a residue outlet 12. The chromium plate photomask cleaning equipment includes a residue collection mechanism 4 and a control system 5. The residue collection mechanism 4 includes a vacuum extraction component 41, a filter component 42, and a residue collector 43. The filter component 42 is connected to the residue outlet 12 and the residue collector 43. The vacuum extraction component 41 is connected to the filter component 42 and also to the control system 5. Under the control of the control system 5 and the action of the vacuum extraction component 41, the cleaned residue is filtered by the filter component 42, the gas is discharged through the vacuum extraction component 41, and the residue is discharged into the residue collector 43. In some embodiments, the vacuum extraction component 41 is a rotary vane vacuum pump with a pumping speed of 10 L / s, which can make the vacuum degree in the vacuum cleaning chamber 1 reach 10 -2 -10 -1 Pa; The filter assembly 42 is equipped with a high-precision filter membrane that can trap residues with a particle size greater than 0.1μm; The residue collector 43 is detachably connected to the filter assembly 42 for easy residue cleaning.

[0085] As described above, by cooperating with the vacuum suction component 41, the filter component 42, and the residue collector 43, the cleaned residue is discharged by vacuum suction, which has at least the following advantages:

[0086] 1) Because the photoresist vaporized by the light emitted by the light-absorbing and emitting mechanism 3 can be promptly extracted from the vacuum cleaning chamber 1 by the aforementioned residue collection mechanism 4, it will not settle or adhere in the vacuum cleaning chamber 1, thus avoiding secondary contamination of the chromium plate photomask 20. It can also prevent the vaporized photoresist from condensing and depositing on the cavity wall or optical components, reducing the frequency of equipment maintenance.

[0087] 2) Because the vacuum extraction component 41 continuously removes residues, it can maintain a stable vacuum environment in the vacuum cleaning chamber 1, ensuring that the laser cleaning process is stable and reliable.

[0088] 3) Because the vaporized photoresist and other materials are removed by the residue collection mechanism 4, they will not accumulate locally and form high pressure or high temperature, thus reducing the risk of thermal impact and damage to the chromium plate photomask 20 and the vacuum cleaning chamber 1.

[0089] 4) Because the vaporized photoresist is sucked out by the residue collection mechanism 4 and the light emitted by the light emission mechanism 3 can be used to clean the chromium plate photomask 20 simultaneously through the control of the control system 5, without interrupting the laser cleaning process, it is conducive to achieving continuous and automated cleaning and improving overall work efficiency.

[0090] 5) Because the vaporized photoresist is extracted and collected by the residue collection mechanism 4, the residue collection mechanism 4 and the vacuum cleaning chamber 1 are in a sealed state, which can prevent the leakage of harmful organic waste gas and improve the safety and environmental protection of the equipment.

[0091] For the aforementioned chromium plate photomask cleaning equipment, a control system 5 can be used. This control system 5 can be a PLC controller, electrically connected to the sealing door 13 of the vacuum cleaning chamber 1, the vacuum adsorption assembly 22 and temperature sensing device 24, the light generation assembly 31 (e.g., power regulator 32), the light scanning assembly 32 (e.g., the two-dimensional moving platform 322 and laser energy monitoring assembly 323 of 4), the vacuum suction assembly 41 of the residue collection mechanism 4, and the cleaning area positioning mechanism 7. The control system 6 has a built-in touchscreen, allowing for manual setting or automatic matching of cleaning parameters (e.g., the size of the chromium plate photomask, as different sizes can be used to confirm the coordinates of the area to be measured, etc.). In some embodiments, the aforementioned components may have their own control systems or no control system at all. For example, the sealing door 13 may be without a control system and can be manually closed; the cleaning area positioning mechanism 7 may have its own control system.

[0092] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope. The scope of protection of the present invention is defined by the appended claims, specification, and their equivalents.

Claims

1. A chromium plate photomask cleaning device, characterized in that, include: A vacuum cleaning chamber is provided for the chromium plate photomask to enter and exit, and the vacuum cleaning chamber is in a sealed state during the cleaning of the chromium plate photomask; A photomask support mechanism, located inside the vacuum cleaning chamber, is used to fix the chromium plate photomask; A light emitting mechanism emits light rays that dissolve residues on the chromium plate photomask and are reflected by the chromium layer of the chromium plate photomask and the substrate mirror surface. The residue collection mechanism is connected to the interior of the vacuum cleaning chamber to collect dissolved residues.

2. The chromium plate photomask cleaning apparatus according to claim 1, wherein The chromium layer and substrate of the chromium plate photomask have a reflectivity of not less than 90% for the light to achieve the specular reflection; And / or, the light emitting mechanism is a molecular laser emitting mechanism, an excimer laser, an infrared / visible solid-state laser, or a mid-infrared fiber laser.

3. The chrome plate photomask cleaning apparatus of claim 1, wherein, The chromium plate photomask cleaning device includes an anti-reflective coating that covers a first region and a second region on the inner wall of the vacuum cleaning chamber. The anti-reflective coating in the first region absorbs the light emitted by the light emitting mechanism, and the anti-reflective coating in the second region absorbs the light reflected by the chromium plate photomask.

4. The chrome plate photomask cleaning apparatus of claim 1, wherein, The photomask support mechanism includes a support platform and a vacuum adsorption component, and the support platform is provided with adsorption holes. The vacuum adsorption component is connected to all the adsorption holes; the vacuum adsorption component adsorbs the chromium plate photomask onto the support stage through the adsorption holes.

5. The chromium plate photomask cleaning equipment according to claim 4, characterized in that, The chromium plate photomask cleaning device includes a plurality of positioning pins, which are disposed on the support platform and distributed circumferentially along the chromium plate photomask to limit the chromium plate photomask.

6. The chromium plate photomask cleaning equipment according to claim 1, characterized in that, The chromium plate photomask cleaning equipment includes a cleaning area positioning mechanism and a control system. The cleaning area positioning mechanism obtains the coordinates of the cleaning area of ​​the chromium plate photomask. The control system controls the light emitted by the light emitting mechanism to be directed toward the cleaning area according to the coordinates.

7. The chromium plate photomask cleaning equipment according to claim 6, characterized in that, The light emitting mechanism includes a light generating component and a light scanning component, wherein the light generating component generates light; The optical scanning component is connected to the control system and includes a two-dimensional moving platform; Under the control of the control system and the action of the two-dimensional moving platform, the light generating component moves along at least one of the transverse and longitudinal directions of the partition photomask according to the coordinates, so that the light generated by the light generating component is directed toward the area to be cleaned; And / or, the cleaning area positioning mechanism includes a visual positioning mechanism, including a lens facing the photomask carrying mechanism to image the chromium plate photomask.

8. The chromium plate photomask cleaning equipment according to claim 7, characterized in that, The optical scanning component includes an energy monitoring component, which is connected to the control system. The control system reduces the energy of the light emitted by the light generating component when the monitored value of the energy monitoring component is greater than a preset value; and increases the energy of the light emitted by the light generating component when the monitored value is less than the preset value.

9. The chromium plate photomask cleaning equipment according to claim 7, characterized in that, The chromium plate photomask cleaning equipment includes a temperature sensing device; the temperature sensing device obtains the temperature of the area to be cleaned; the control system controls the energy of the light emitted by the light emitting mechanism according to the temperature of the area to be cleaned, and / or controls the speed of the light scanning component in the horizontal and vertical directions.

10. The chromium plate photomask cleaning equipment according to claim 1, characterized in that, The vacuum cleaning chamber includes a residue outlet; the chromium plate photomask cleaning equipment includes a control system. The residue collection mechanism includes a vacuum suction component, a filter component, and a residue collector; the filter component is connected to the residue outlet and the residue collector. The vacuum extraction component is connected to the filter component and also to the control system. Under the control of the control system and the action of the vacuum extraction component, the cleaned residue is filtered by the filter component, the gas is discharged through the vacuum extraction component, and the residue is discharged into the residue collector.

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