A method and system for cleaning and drying silicon wafers
Patent Information
- Application Number
- CN202610519595.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-04-20
- Publication Date
- 2026-07-24
Smart Images
Figure CN122458712A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of silicon wafer manufacturing technology, and specifically to a method and system for cleaning and drying silicon wafers. Background Technology
[0002] In the monocrystalline silicon wafer production process, the sliced silicon wafers need to be placed in a special polymer (such as PEEK, PVDF) basket for post-processing steps such as cleaning, acid / alkali etching, deionized water rinsing, and drying. Existing silicon wafer cleaning and drying processes often use a uniform drying curve. However, in practice, when silicon wafers are sent to the dryer after cleaning, the liquid film morphology on the surface of different batches of wafers may vary. If a uniform drying curve is used to dry wafers with different liquid film states, it may lead to the formation of hidden contamination marks or "coffee rings" on the surface of wafers whose liquid film has already broken when they are sent to the dryer, due to the localized enrichment of chemicals in the cleaning solution. Therefore, a new silicon wafer cleaning and drying scheme needs to be designed to overcome the above-mentioned technical defects. Summary of the Invention
[0003] In order to overcome the shortcomings of the prior art, the present invention aims to provide a method and system for cleaning and drying silicon wafers, which can reduce the risk of "coffee ring" effect or hidden contamination marks on silicon wafers after cleaning and drying, and improve the yield of silicon wafers.
[0004] To solve the above problems, the technical solution adopted by the present invention is as follows: a method for cleaning and drying silicon wafers, characterized by comprising the following steps: Pre-clean the slit silicon wafers; The pre-cleaned silicon wafers are placed into the silicon wafer basket; Immerse the silicon wafer basket into the cleaning tank for primary cleaning of the silicon wafers; The silicon wafer basket that has undergone the main cleaning is sent into a sealed drying chamber, and the in-situ wetting angle of the contact area between the edge of the silicon wafer and the teeth of the silicon wafer basket is measured by an optical wetting angle measuring instrument in the sealed drying chamber. The detected in-situ wetting angle value is matched with multiple preset wetting angle intervals, and the infrared radiation array is controlled to irradiate and dry the silicon wafer basket according to the drying strategy corresponding to the matched wetting angle interval. After drying, the silicon wafers are randomly inspected, and the inspected silicon wafers are subjected to the same texturing and thermal oxidation treatment. The silicon wafers after treatment are then tested for any abnormalities. Silicon wafer batches that pass random inspections will be categorized and stored in the warehouse.
[0005] In the above-mentioned method for cleaning and drying silicon wafers, in the step of matching the detected in-situ wetting angle value with multiple preset wetting angle intervals and controlling the infrared radiation array to irradiate and dry the silicon wafer according to the drying strategy corresponding to the matched wetting angle interval, if the in-situ wetting angle value is lower than the lower limit of the preset discrete droplet interval, the silicon wafer is first uniformly heated by medium and short infrared waves, so that the surface temperature of the silicon wafer rises from room temperature to the preset maximum drying temperature at a preset heating rate, and then the temperature is maintained at the maximum drying temperature for a preset first time threshold time.
[0006] In the above-mentioned method for cleaning and drying silicon wafers, in the step of matching the detected in-situ wetting angle value with a plurality of preset wetting angle intervals, and controlling the infrared radiation array to irradiate and dry the silicon wafer according to the drying strategy corresponding to the matched wetting angle interval, if the in-situ wetting angle value falls within a preset discrete droplet interval, the silicon wafer is first irradiated with short-wave infrared for a preset second time threshold time, and then switched to mid-wave infrared for irradiation of the silicon wafer for a preset third time threshold time.
[0007] In the above-mentioned method for cleaning and drying silicon wafers, in the step of matching the detected in-situ wetting angle value with multiple preset wetting angle intervals, and controlling the infrared radiation array to irradiate and dry the silicon wafer according to the drying strategy corresponding to the matched wetting angle interval, if the in-situ wetting angle value is higher than the upper limit of the preset discrete droplet interval, then a preset amount of saturated water vapor at a preset temperature is first introduced into the sealed drying chamber, and then the silicon wafer is uniformly heated by medium and short infrared waves, so that the surface temperature of the silicon wafer rises from room temperature to the preset maximum drying temperature at a preset heating rate, and then is maintained at the maximum drying temperature for a preset first time threshold time; or after introducing saturated water vapor, the silicon wafer is first irradiated by short-wave infrared for a preset second time threshold time, and then switched to medium-wave infrared for irradiation of the silicon wafer for a preset third time threshold time.
[0008] In the above-mentioned method for cleaning and drying silicon wafers, the step of matching the detected in-situ wetting angle value with a plurality of preset wetting angle intervals and controlling the infrared radiation array to irradiate and dry the silicon wafer basket according to the drying strategy corresponding to the matched wetting angle intervals involves adjusting the infrared radiation power of each unit in the infrared radiation array according to the temperature difference between the silicon wafers, so that the surface temperature difference between any two adjacent silicon wafers in the silicon wafer basket is within a preset temperature difference interval.
[0009] In the above-mentioned method for cleaning and drying silicon wafers, in the step of immersing the silicon wafer basket into the cleaning tank for main cleaning, the cleaning solution used for main cleaning is a mixed alkaline solution containing 0.005% by mass of a nonionic fluorocarbon surfactant. During the main cleaning process, megasonic waves are applied to the cleaning solution and the silicon wafer basket in the cleaning tank.
[0010] A silicon wafer cleaning and drying system for implementing the above-described silicon wafer cleaning and drying method includes a cleaning machine, a dryer, a silicon wafer sorting machine, and a silicon wafer basket. The silicon wafer basket is used to load silicon wafers to be cleaned and dried. The cleaning machine is used to pre-clean and main clean the silicon wafers loaded in the silicon wafer basket. The dryer is used to dry the silicon wafer basket after main cleaning. The silicon wafer sorting machine is used to sort and store batches of silicon wafers that have passed random inspection. An infrared radiation array and an optical wetting angle measuring instrument are installed in the sealed drying chamber of the dryer. The infrared radiation array and the optical wetting angle measuring instrument are electrically connected to the drying controller of the dryer. The drying controller matches a drying strategy based on the in-situ wetting angle value of the contact area between the edge of the silicon wafer and the teeth of the silicon wafer basket detected by the optical wetting angle measuring instrument, and controls the infrared radiation array to irradiate and dry the silicon wafer basket according to the matched drying strategy.
[0011] The silicon wafer cleaning and drying system described above includes a silicon wafer basket comprising a main frame, on which multiple parallel support rods are provided, and each support rod is provided with a locking tooth, on which multiple support cards are provided at equal intervals, and on the surface of the locking tooth is provided with an elastic buffer layer.
[0012] In the aforementioned silicon wafer cleaning and drying system, the elastic buffer layer is made of perfluoroether rubber, and the thickness of the elastic buffer layer is between 1.5 and 2.5 mm.
[0013] In the aforementioned silicon wafer cleaning and drying system, the surface of the elastic buffer layer is provided with multiple longitudinal grooves, the depth of which is between 50 and 200 micrometers and the width of which is between 100 and 300 micrometers.
[0014] Compared with existing technologies, the advantages of this invention are as follows: 1. By detecting the in-situ wetting angle of the contact area between the edge of the silicon wafer and the teeth of the silicon wafer basket in the sealed drying chamber, the liquid film state on the surface of the silicon wafer is determined, and an appropriate drying strategy is selected based on the liquid film state on the surface of the silicon wafer. This avoids the accumulation of chemical substances in the cleaning solution in local areas due to excessively fast drying speed when the liquid film on the surface of the silicon wafer breaks, thus avoiding the "coffee ring" effect caused by local accumulation of chemical substances, or the appearance of hidden contamination marks on the surface of the silicon wafer. 2. By setting an elastic buffer layer on the surface of the teeth that contact the silicon wafer in the silicon wafer basket, the contact stress between the teeth and the silicon wafer is reduced, avoiding macroscopically visible "basket marks" such as microcracks and indentations on the silicon wafer caused by contact stress. 3. By creating longitudinal grooves on the surface of the elastic buffer layer of the toother, a microscopic "barrier" is avoided at the contact surface between the toother and the silicon wafer. This ensures sufficient exchange and renewal of cleaning solution, etching solution, and rinsing water at the contact surface during cleaning, guaranteeing that the chemical reaction rate and contaminant removal efficiency at the contact surface are consistent with those at the non-contact surface. Simultaneously, it ensures unobstructed evaporation paths for the liquid film in the contact area, guaranteeing a drying effect that matches the liquid film state, further preventing the "coffee ring" effect and the formation of hidden contamination marks, and improving the yield of silicon wafers.
[0015] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Attached Figure Description
[0016] Figure 1 This is a schematic flowchart of a silicon wafer cleaning and drying method according to an embodiment of the present invention.
[0017] Figure 2 This is a flowchart of the drying strategy matching process according to an embodiment of the present invention.
[0018] Figure 3 This is a block diagram illustrating the control principle of the dryer according to an embodiment of the present invention.
[0019] Figure 4 This is a schematic diagram of the structure of a silicon wafer flower basket according to an embodiment of the present invention.
[0020] Figure 5 This is a schematic diagram of the tooth structure according to an embodiment of the present invention.
[0021] Figure 6 for Figure 5 Enlarged diagram of point A in the middle.
[0022] Figure 7 This is a cross-sectional view of the toothed jaws according to an embodiment of the present invention.
[0023] Explanation of icon numbers: 100 Main frame, 110 End plate, 120 Connecting rod, 130 Lower support rod, 200 Support insert rod, 300 Clamping tooth, 310 Support clip, 320 Rod sleeve, 330 Elastic buffer layer, 331 Groove. Detailed Implementation
[0024] The embodiments of the present invention are described in detail below, with reference to... Figure 1 The present invention provides a method for cleaning and drying silicon wafers, comprising the following steps: Pre-clean the slit silicon wafers; The pre-cleaned silicon wafers are placed into the silicon wafer basket; Immerse the silicon wafer basket into the cleaning tank for primary cleaning of the silicon wafers; The silicon wafer basket that has undergone the main cleaning is sent into a sealed drying chamber, and the in-situ wetting angle of the contact area between the edge of the silicon wafer and the tooth 300 of the silicon wafer basket is measured by an optical wetting angle measuring instrument in the sealed drying chamber. The detected in-situ wetting angle value is matched with multiple preset wetting angle intervals, and the infrared radiation array is controlled to irradiate and dry the silicon wafer basket according to the drying strategy corresponding to the matched wetting angle interval. After drying, the silicon wafers are randomly inspected, and the inspected silicon wafers are subjected to the same texturing and thermal oxidation treatment. The silicon wafers after treatment are then tested for any abnormalities. Silicon wafer batches that pass random inspections will be categorized and stored in the warehouse.
[0025] The silicon wafer cleaning and drying method uses an optical wetting angle measuring instrument to measure the in-situ wetting angle of the contact area between the edge of the silicon wafer and the 300-degree contact teeth of the silicon wafer basket. This determines the integrity of the liquid film on the surface of the silicon wafer entering the sealed drying chamber. Based on the integrity of the liquid film, different preset drying strategies are matched. This avoids the problem of inconsistent drying speeds of residual cleaning liquid in different areas when the liquid film breaks due to uniform drying parameters. This prevents some areas from drying too quickly, causing the chemical substances in the cleaning liquid to accumulate in local areas. Consequently, the surface of the silicon wafer may exhibit a "coffee ring" effect or hidden contamination marks due to the accumulation of chemical substances, thereby improving the yield of the produced silicon wafers.
[0026] Understandably, drying strategies can include different drying curves. When the liquid film on the silicon wafer surface is relatively intact, a drying curve with gradually increasing power can be used to raise the temperature of the silicon wafer surface at a basically uniform rate, quickly drying the residual cleaning solution on the silicon wafer surface and uniformly removing the chemicals in the cleaning solution during the drying process. When the liquid film on the silicon wafer surface is partially broken, the silicon wafer can be irradiated first with short-wave infrared light with strong penetration, allowing the infrared radiation to penetrate the liquid film and be directly absorbed by the silicon wafer substrate, causing the silicon wafer substrate to heat up slightly. This allows the bottom of the liquid film to be heated by the silicon wafer first, providing a thermal potential difference basis for inward fluid movement. Subsequently, medium-wave infrared light is used to continuously heat the silicon wafer, causing the liquid film to begin to heat up and... The liquid film forms an inward temperature gradient, causing the liquid within the film to flow inward under the influence of the temperature gradient. This continuously pulls particles from the broken edges back to the center of the liquid film, ensuring that the solute in the cleaning solution is evenly distributed within the liquid film. This prevents the solute from accumulating at the edges due to rapid heating, thus avoiding the formation of "coffee rings" or marks on the silicon wafer surface. When a large area of the liquid film on the silicon wafer surface is broken, the solute in the cleaning solution has already accumulated significantly at the edges of the remaining liquid film due to uneven natural evaporation before entering the sealed dryer. Therefore, it is necessary to repair the liquid film on the silicon wafer surface first, and then select one of the two drying curves mentioned above to continue drying the silicon wafer based on the integrity of the repaired liquid film.
[0027] Reference Figure 2In this embodiment, specifically, when the in-situ wetting angle of the contact area between the edge of the silicon wafer and the teeth 300 of the silicon wafer basket is less than or equal to 15°, the liquid film on the surface of the silicon wafer is considered relatively intact. Drying curve A is used to control the infrared radiation array in the sealed drying chamber to irradiate the silicon wafer basket, that is, to irradiate the silicon wafer basket with medium-short wave infrared (0.76-6μm), and to raise the surface temperature of the silicon wafer from room temperature to 80°C at a rate of 2-3°C, and maintain it at 80°C for 30 seconds, allowing the liquid film on the surface of the silicon wafer to evaporate uniformly and slowly. When the in-situ wetting angle is between 15-40°, the liquid film on the surface of the silicon wafer is considered to have partially broken, appearing as discrete droplets. At this time, drying curve B is used to control the infrared radiation array to irradiate the silicon wafer basket, that is, to first use short wave infrared (0.76-2μm) to perform a 0.5-second pulsed penetration heating on the silicon wafer basket, causing a slight temperature increase in the silicon wafer substrate, and then transferring the heat to... At the bottom of the liquid film, the system is then switched to mid-wave infrared (2-4μm) for continuous heating to promote uniform evaporation on the surface of the liquid film. An "inside-out" heating sequence induces inward flow within the liquid film, preventing solute from being transported to the edges and thus eliminating the "coffee ring" effect. When the measured in-situ wetting angle is greater than or equal to 40°, it is considered that a large area of the liquid film on the silicon wafer surface has fractured, and a high concentration of solute has accumulated in the cleaning solution. At this point, a small amount of 40°C saturated water vapor is first introduced into the sealed drying chamber to form an extremely thin and uniform "repairing liquid film" on the silicon wafer surface, uniformly dissolving the concentrated solute. The in-situ wetting angle of the contact area between the silicon wafer edge and the 300° tooth of the silicon wafer basket is then re-measured, and the integrity of the repaired liquid film is re-measured. If the liquid film is basically completely repaired, drying curve A is used for drying; if the liquid film is repaired to the point of partial fracture, drying curve B is used for drying.
[0028] Understandably, in order to ensure the consistency of silicon wafer drying, there is a mapping relationship between each area of the silicon wafer basket and each infrared radiation unit in the infrared radiation array. During the drying process, infrared images of the silicon wafer basket are captured by an infrared camera, and the temperature of each silicon wafer in the basket is analyzed based on the infrared images. The power of the corresponding infrared radiation unit is adjusted according to the temperature of each silicon wafer to make the surface temperature difference between adjacent silicon wafers less than ±1.5℃.
[0029] Understandably, after removing cutting fluid and coarse silicon powder from the silicon wafer surface through offline or online pre-cleaning, the pre-cleaned silicon wafers need to be immediately loaded into a buffered silicon wafer basket. During loading, it is essential to ensure that the silicon wafer is supported by at least four pairs (eight pieces) of symmetrically distributed support clips 310, with the center plane of the silicon wafer aligned with the symmetrical face of the clip teeth 300 to prevent unilateral stress on the silicon wafer. During the main cleaning, the cleaning solution is a mixed alkaline solution containing 0.005% (w / w) of a nonionic fluorocarbon surfactant. This mixed alkaline solution can consist of KOH and some additives. This cleaning solution can significantly reduce the surface tension of the liquid at the contact interface between the silicon wafer and the clip teeth 300 of the silicon wafer basket through trace amounts of surfactant, promoting the exchange of liquid on the silicon wafer surface with the cleaning solution in the cleaning tank, and removing foreign matter from the silicon wafer surface. To further enhance the interface cleaning effect, megasonic waves (frequency at 800kHz) are also applied to the cleaning tank during the cleaning process.
[0030] Understandably, to inspect the quality of the cleaned and dried silicon wafers and ensure the yield of the wafers entering the warehouse, a certain number of wafers are randomly selected from each batch, such as 5 wafers out of every 2000 wafers. These sampled wafers undergo texturing and thermal oxidation processes identical to those used on actual battery production lines. After processing, a micro-confocal laser Raman spectroscopy system scans the edge region where the silicon wafer contacts the 300 chuck teeth to detect any characteristic peak shifts caused by residual stress. Simultaneously, a high-resolution (≥500x) optical microscope is used to examine the edges for any abnormal textures. When there is neither characteristic peak shift nor abnormal texture at the edge where the processed silicon wafer contacts the 300 chuck teeth, the batch of wafers is considered a defect-free product without hidden basket wedger 300 defects. Finally, a wafer sorting machine categorizes the wafers based on thickness, resistivity, minority carrier lifetime, etc., to ensure that defect-free wafers are properly stored.
[0031] Based on the same inventive concept, embodiments of the present invention also provide a silicon wafer cleaning and drying system for implementing the above-described silicon wafer cleaning and drying method, comprising a cleaning machine, a dryer, a silicon wafer sorting machine, and silicon wafer baskets. The silicon wafer baskets are used to load the silicon wafers to be cleaned and dried. The cleaning machine is used to perform pre-cleaning and main cleaning on the silicon wafers loaded in the silicon wafer baskets. The dryer is used to dry the silicon wafer baskets after the main cleaning. The silicon wafer sorting machine is used to sort and store batches of silicon wafers that pass random inspection. (Refer to...) Figure 3An infrared radiation array and an optical wetting angle measuring instrument are installed inside the sealed drying chamber of the dryer. The infrared radiation array and the optical wetting angle measuring instrument are electrically connected to the drying controller of the dryer. The drying controller may include a processor and a memory. The memory stores computer programs and various drying curves. The processor implements the above-mentioned silicon wafer cleaning and drying method by calling and executing the computer programs in the memory. It controls the optical wetting angle measuring instrument to detect the in-situ wetting angle of the contact area between the edge of the silicon wafer and the tooth 300 of the silicon wafer basket. Based on the detected in-situ wetting angle value, it queries the mapping relationship between the in-situ wetting angle and the drying strategy stored in the memory in advance, so as to match a suitable drying strategy according to the in-situ wetting angle value, and controls the infrared radiation array to irradiate and dry the silicon wafer basket according to the matched drying strategy.
[0032] In one possible design, the processor may include one or more processing units. The processor and memory may be implemented on the same chip or on separate chips. The processor may be a general-purpose processor, such as a central processing unit (CPU), digital signal processor, application-specific integrated circuit, field-programmable gate array or other programmable logic device, discrete gate or transistor logic device, or discrete hardware component, capable of implementing or executing the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the dynamic optimization algorithm for large model parameters disclosed in the embodiments of this application can be directly implemented by the hardware processor, or implemented by a combination of hardware and software modules in the processor.
[0033] Memory, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules. Memory can include at least one type of storage medium, such as flash memory, hard disk, multimedia card, card-type memory, random access memory (RAM), static random access memory (SRAM), programmable read-only memory (PROM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), magnetic memory, magnetic disk, optical disk, etc. Memory is any other medium capable of carrying or storing desired program code in the form of instructions or data structures that can be accessed by a computer, but is not limited to this. The memory in the embodiments of this application can also be a circuit or any other device capable of implementing storage functions for storing program instructions and / or data.
[0034] It is understood that, in some embodiments, the cleaning tank of the cleaning machine for main cleaning is equipped with a sound wave generator, which generates megasonic waves to assist in the main cleaning of the silicon wafers in the wafer basket. It is also understood that, in some embodiments, pre-cleaning can be performed by the rinsing mechanism in the silicon wafer slitting machine.
[0035] It is understood that in some embodiments, the closed drying chamber of the dryer is connected to a saturated water vapor supply device, which can introduce saturated water vapor into the closed drying chamber when the value of the in-situ wetting angle is detected to be too high, so as to repair the liquid film on the surface of the silicon wafer.
[0036] Understandably, referring to Figures 4 to 6The silicon wafer basket includes a main frame 100, on which multiple parallel support rods 200 are provided. Each support rod 200 has locking teeth 300, and multiple support cards 310 are evenly spaced on the locking teeth 300. The edges of the silicon wafers can be inserted into the gaps between adjacent support cards 310, allowing multiple silicon wafers to be stably placed in the basket at equal intervals. The main frame 100 typically includes two U-shaped end plates 110, with four parallel connecting rods 120 connecting the four corners of the two end plates 110 to form a rectangular frame. Several handles are provided on the outer side of the end plates 110 to facilitate gripping by robotic arms and to facilitate placing the silicon wafer basket in cleaning and drying machines. At least one lower support rod 130 is provided on the lower side of the main frame, which is used to support the bottom of the silicon wafers. In this embodiment, two lower support rods 130 are provided on the lower side of the frame body. These two lower support rods 130 are symmetrically and parallelly arranged on the lower side of the frame body along its length. The two ends of each lower support rod 130 are connected to the middle of the bottom edge of the end plate 110. To achieve stable support for the silicon wafer, two sets of support rods 200 are provided on the frame body. Each set includes two pairs of four support rods 200. Two support rods 200 in each pair are symmetrically arranged on both sides of the main frame 100. The four pairs of support rods 200 are arranged from top to bottom along the height direction of the main frame 100. The two ends of each support rod 200 are connected to one side of each of the two end plates 110. Four mounting slots are provided on both sides of the end plate 110 from top to bottom, and the ends of the support rods 200 can be embedded in the corresponding mounting slots. Four locking teeth 300 are provided on the main frame 100, as shown in the figure. Figure 5 The locking teeth 300 include two sleeves 320 that can be inserted into the support rods 200. Multiple support cards 310 are arranged in parallel and at equal intervals between the two sleeves 320. The locking teeth 300 can be installed by fitting the two sleeves 320 onto the two support rods 200 on the same side of the same group. The four pairs of support cards 310 at the same position on the two pairs of locking teeth 300 can provide stable support for the edges on both sides of the inserted silicon wafer.
[0037] In this embodiment, to avoid micro-stress concentration or nano-damage to the surface lattice of the silicon wafer due to instantaneous local pressure during ultrasonic vibration, fluid impact, and transfer in the process tank during the cleaning process, refer to Figure 7An elastic buffer layer 330 is provided on the outer surface of the rigid skeleton of the card teeth 300 to reduce the contact pressure in the contact area between the silicon wafer and the silicon wafer basket, and to prevent micro-stress marks from being left between the silicon wafer and the silicon wafer basket. In this embodiment, the elastic buffer layer 330 is preferably made of perfluoroether rubber (FFKM), with a Shore A hardness of 40±5, a compression set of ≤8% after continuous compression for 22 hours at 150°C, and excellent resistance to hydrofluoric acid, potassium hydroxide, and high temperature. The initial thickness of the elastic buffer layer 330 is preferably between 1.5mm and 2.5mm. By reasonably designing the spacing between the support cards 310 in conjunction with the silicon wafer thickness, the static contact pressure between the support cards 310 and the silicon wafer is ensured to be ≤0.3MPa, and the peak pressure under ultrasonic conditions is ≤0.8MPa, which is far below the micro-yield limit of the silicon wafer.
[0038] Reference Figure 7 In this embodiment, in order to ensure that the cleaning fluid at the contact area between the silicon wafer edge and the tooth 300 can be fully exchanged and renewed during cleaning, to ensure that the chemical reaction rate and contaminant removal efficiency at the contact surface are consistent with those at the non-contact surface, and to ensure that the liquid film evaporation path at the contact surface is unobstructed, and to further avoid the generation of hidden marks at the contact area between the silicon wafer and the tooth 300, longitudinal grooves 331 are provided on the outer surface of the elastic buffer layer 330 on the tooth 300. The grooves 331 are microgrooves with a size at the micrometer level, and the spacing between adjacent grooves 331 is 0.8-1.5mm, so as to ensure surface contact between the silicon wafer and the tooth 300, and to ensure that the pressure between the silicon wafer and the tooth 300 is always lower than the micro yield limit of the silicon wafer. The depth of the trench 331 should ideally be between 50-200 micrometers, and the width should ideally be between 100-300 micrometers. The longitudinal trench 331 facilitates the longitudinal flow of cleaning fluid and other liquids along the edge of the silicon wafer. Combined with the surfactants in the cleaning fluid, this breaks down the surface tension of the liquid at the contact surface, promoting exchange between the liquid in the trench 331 and the main cleaning fluid in the cleaning tank, ensuring effective cleaning at the contact surface. The micro-grooves 331 also protect the silicon wafer while ensuring a clear evaporation path for the liquid at the contact area between the silicon wafer and the clips 300 during drying. This prevents uneven evaporation from causing solute accumulation in the cleaning fluid, which could lead to a "coffee ring" effect or the formation of hidden marks.
[0039] It should be noted that in the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" or "second" is mentioned, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.
[0040] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus systems, and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.
[0041] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.
[0042] These computer program instructions can also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.
[0043] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.
[0044] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.
Claims
1. A method for cleaning and drying silicon wafers, characterized in that, Includes the following steps: Pre-clean the slit silicon wafers; The pre-cleaned silicon wafers are placed into the silicon wafer basket; Immerse the silicon wafer basket into the cleaning tank for primary cleaning of the silicon wafers; The silicon wafer basket that has undergone the main cleaning is sent into a sealed drying chamber, and the in-situ wetting angle of the contact area between the edge of the silicon wafer and the teeth (300) of the silicon wafer basket is measured by an optical wetting angle measuring instrument in the sealed drying chamber. The detected in-situ wetting angle value is matched with multiple preset wetting angle intervals, and the infrared radiation array is controlled to irradiate and dry the silicon wafer basket according to the drying strategy corresponding to the matched wetting angle interval. After drying, the silicon wafers are randomly inspected, and the inspected silicon wafers are subjected to the same texturing and thermal oxidation treatment. The silicon wafers after treatment are then tested for any abnormalities. Silicon wafer batches that pass random inspections will be categorized and stored in the warehouse.
2. The method for cleaning and drying silicon wafers according to claim 1, characterized in that, In the step of matching the detected in-situ wetting angle value with multiple preset wetting angle intervals and controlling the infrared radiation array to irradiate and dry the silicon wafer basket according to the drying strategy corresponding to the matched wetting angle interval, if the in-situ wetting angle value is lower than the lower limit of the preset discrete droplet interval, the silicon wafer is first uniformly heated by medium and short infrared waves, so that the surface temperature of the silicon wafer rises from room temperature to the preset maximum drying temperature at a preset heating rate, and then the temperature is maintained at the maximum drying temperature for a preset first time threshold.
3. The method for cleaning and drying silicon wafers according to claim 1, characterized in that, In the step of matching the detected in-situ wetting angle value with multiple preset wetting angle intervals, and controlling the infrared radiation array to irradiate and dry the silicon wafer basket according to the drying strategy corresponding to the matched wetting angle interval, if the in-situ wetting angle value falls within a preset discrete droplet interval, the silicon wafer is first irradiated with short-wave infrared for a preset second time threshold time, and then switched to mid-wave infrared for irradiation of the silicon wafer for a preset third time threshold time.
4. The method for cleaning and drying silicon wafers according to claim 1, characterized in that, In the step of matching the detected in-situ wetting angle value with multiple preset wetting angle intervals, and controlling the infrared radiation array to irradiate and dry the silicon wafer basket according to the drying strategy corresponding to the matched wetting angle interval, if the in-situ wetting angle value is higher than the upper limit of the preset discrete droplet interval, a preset amount of saturated water vapor at a preset temperature is first introduced into the sealed drying chamber, and then the silicon wafer is uniformly heated by medium and short infrared waves, so that the surface temperature of the silicon wafer rises from room temperature to the preset maximum drying temperature at a preset heating rate, and then is maintained at the maximum drying temperature for a preset first time threshold time; or after introducing saturated water vapor, the silicon wafer is first irradiated by short-wave infrared for a preset second time threshold time, and then switched to medium-wave infrared for irradiation of the silicon wafer for a preset third time threshold time.
5. The method for cleaning and drying silicon wafers according to claim 1, characterized in that, In the step of matching the detected in-situ wetting angle value with a number of preset wetting angle intervals and controlling the infrared radiation array to irradiate and dry the silicon wafer basket according to the drying strategy corresponding to the matched wetting angle interval, the infrared radiation power of each unit in the infrared radiation array is adjusted according to the temperature difference between the silicon wafers so that the surface temperature difference between any two adjacent silicon wafers in the silicon wafer basket is within a preset temperature difference interval.
6. The method for cleaning and drying silicon wafers according to claim 1, characterized in that, In the step of immersing the silicon wafer basket into the cleaning tank for primary cleaning, the cleaning solution used for primary cleaning is a mixed alkaline solution containing 0.005% by mass of a nonionic fluorocarbon surfactant. During the primary cleaning process, megasonic waves are applied to the cleaning solution and the silicon wafer basket in the cleaning tank.
7. A silicon wafer cleaning and drying system for implementing the silicon wafer cleaning and drying method according to any one of claims 1 to 6, comprising a cleaning machine, a dryer, a silicon wafer sorting machine, and a silicon wafer basket, wherein the silicon wafer basket is used to load silicon wafers to be cleaned and dried, the cleaning machine is used to pre-clean and main clean the silicon wafers loaded in the silicon wafer basket, the dryer is used to dry the silicon wafer basket after main cleaning, the silicon wafer sorting machine is used to sort and store batches of silicon wafers that have no abnormalities after random inspection, and an infrared radiation array and an optical wetting angle measuring instrument are provided in the sealed drying chamber of the dryer, the infrared radiation array and the optical wetting angle measuring instrument are electrically connected to the drying controller of the dryer, the drying controller matches a drying strategy according to the value of the in-situ wetting angle of the contact area between the edge of the silicon wafer and the tooth (300) of the silicon wafer basket detected by the optical wetting angle measuring instrument, and controls the infrared radiation array to irradiate and dry the silicon wafer basket according to the matched drying strategy.
8. The silicon wafer cleaning and drying system according to claim 7, characterized in that, The silicon wafer basket includes a main frame (100), on which a plurality of parallel support rods (200) are provided. Each support rod (200) has a locking tooth (300), and each locking tooth (300) has a plurality of support cards (310) arranged at equal intervals. The surface of the locking tooth (300) is provided with an elastic buffer layer (330).
9. The silicon wafer cleaning and drying system according to claim 8, characterized in that, The elastic buffer layer (330) is made of perfluoroether rubber and the thickness of the elastic buffer layer (330) is between 1.5 and 2.5 mm.
10. The silicon wafer cleaning and drying system according to claim 8, characterized in that, The surface of the elastic buffer layer (330) is provided with multiple longitudinal grooves (331), the depth of the grooves (331) is between 50 and 200 micrometers, and the width of the grooves (331) is between 100 and 300 micrometers.