Wafer defect suppression device and method and groove type wet processing equipment

Abstract

The invention provides a wafer defect suppression device, a wafer defect suppression method and groove type wet processing equipment, the wafer defect suppression device is used for the groove type wet processing equipment, the groove type wet processing equipment comprises a chemical liquid groove for containing chemical liquid, the wafer defect suppression device comprises a humidifier and a cover body, the humidifier comprises a liquid supply part, and the cover body is used for containing the chemical liquid. The liquid supply part is communicated with the chemical liquid tank; and the cover body is used for guiding and maintaining the wet atmosphere on a preset transfer path of the wafer, so that the surface of the wafer is surrounded by the wet atmosphere within a period of time after leaving the chemical liquid tank. The device provides a smooth transition environment from full infiltration to dry air exposure for the liquid film on the surface of the wafer, prevents the liquid film on the outer edge of the top end of the wafer from being broken when the wafer leaves the chemical liquid tank, inhibits the volatilization of chemical liquid on the surface of the wafer, solves the problem of top end defect concentration caused by the lifting sequence of the wafer, and improves the quality of the wafer. And the wafer yield is improved.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor manufacturing technology, specifically relating to a wafer defect suppression device, method, and tank-type wet processing equipment. Background Technology

[0002] With the continuous advancement of semiconductor manufacturing technology, the cleanliness requirements for wafer surface cleaning and etching processes are becoming increasingly stringent. Tank-type wet etching and cleaning equipment remains crucial in semiconductor manufacturing due to its advantages such as large throughput, cost-effectiveness, and mature technology. This type of equipment typically immerses multiple wafers in a process tank filled with chemical solutions for processing, then lifts them out of the liquid and transfers them to the next process. However, due to the inherent characteristics of the physical mechanisms involved, this process can easily introduce defects in specific areas of the wafer, becoming one of the key issues restricting further improvements in process yield.

[0003] Currently, the industry's common solutions to defects generated during wafer pulling mainly focus on optimizing mechanical motion parameters. For example, by increasing the wafer pulling speed, the time difference between the top and bottom of the wafer leaving the liquid surface and being exposed to air is shortened, thereby reducing the differences in chemical evaporation caused by uneven exposure time.

[0004] However, the aforementioned existing technologies have obvious limitations. Increasing the pulling speed cannot fundamentally overcome the effects of gravity and liquid surface tension. The liquid film at the top of the wafer will still thin and break first due to gravity and inertia, exposing this area to the air prematurely. The humidity gradient between the dry machine environment and the humid wafer surface will cause the chemical liquid in the exposed area at the top of the wafer to evaporate rapidly, and the solute will quickly concentrate and dry on the wafer surface. These problems make the edge area at the top of the wafer a weak link in the entire wafer pulling process, resulting in defects at this specific location. Summary of the Invention

[0005] The purpose of this invention is to provide a wafer defect suppression device, method, and tank-type wet processing equipment. This wafer defect suppression device and method can solve the problem of defects generated at the top edge of the wafer due to local liquid film rupture and rapid local chemical evaporation during the critical transition stage when the wafer leaves the chemical bath.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The first aspect of the present invention provides a wafer defect suppression device for use in a tank-type wet processing equipment, wherein the tank-type wet processing equipment includes a chemical solution tank for holding chemical solutions, and the wafer defect suppression device includes:

[0007] A humidifier includes a liquid supply unit connected to the chemical liquid tank, the humidifier being used to atomize the chemical liquid to generate a humid atmosphere consistent with the composition of the chemical liquid in the chemical liquid tank; a cover is used to guide and maintain the humid atmosphere on a preset transfer path of the wafer, so that the wafer surface is surrounded by the humid atmosphere for a period of time after leaving the chemical liquid tank.

[0008] In one embodiment, the humidifier is an ultrasonic humidifier, and its liquid supply section is connected to the chemical liquid tank to atomize the chemical liquid taken from the chemical liquid tank into micron-sized droplets.

[0009] In one embodiment, the cover is connected to or integrally formed with the ultrasonic humidifier, and part or all of the preset transfer path is formed inside the cover.

[0010] In one embodiment, the cover is made of polytetrafluoroethylene or polyvinylidene fluoride.

[0011] In one embodiment, a drive mechanism is further included, which is connected to the cover and is used to drive the cover to move along a preset track, the preset track at least covering the area above the opening of the chemical liquid tank.

[0012] In one embodiment, the preset track includes a first position for covering the slot and a second position for making room for wafer lifting and lowering, and the drive mechanism drives the cover to reciprocate between the first position and the second position.

[0013] In one embodiment, the ultrasonic humidifier has an adjustable operating frequency to generate chemical liquid droplets of different sizes.

[0014] A second aspect of the present invention provides a wafer defect suppression method using the wafer defect suppression device described above, the wafer defect suppression method comprising the following steps: The humidifier is activated before or at the same time the wafer completes its in-cell processing and is about to leave the chemical solution surface to create a humid atmosphere above the wafer. The cover is controlled to move above the wafer, so that the surface of the wafer remains under the humid atmosphere as it rises and leaves the chemical bath. Maintain the humid atmosphere until the wafer is transferred to the next process module or drying area.

[0015] In one embodiment, before activating the humidifier, the following is also included: When the wafer is about to enter the chemical bath, control the cover to move to the clearance position; After the wafer is completely immersed in the chemical solution, the cover is moved to the position that covers the opening of the chemical solution tank.

[0016] In one embodiment, during the wafer's ascent, the moving speed of the cover is controlled to be synchronized with the moving speed of the wafer to maintain the relative position of the cover and the wafer stable.

[0017] A third aspect of the present invention provides a tank-type wet processing apparatus, including a chemical liquid tank and a wafer transfer mechanism, and further including a wafer defect suppression device as described above.

[0018] The wafer defect suppression device provided by this invention is used in a tank-type wet processing equipment. The tank-type wet processing equipment includes a chemical liquid tank for holding chemical liquid. The wafer defect suppression device includes a humidifier and a cover. The humidifier includes a liquid supply section connected to the chemical liquid tank. The humidifier atomizes the chemical liquid to generate a humid atmosphere consistent with the composition of the chemical liquid in the chemical liquid tank. The cover guides and maintains the humid atmosphere along a preset transfer path of the wafer, ensuring that the wafer surface is surrounded by the humid atmosphere for a period of time after leaving the chemical liquid tank. This device provides a smooth transition environment for the liquid film on the wafer surface from full immersion to exposure to dry air, preventing the liquid film at the outer edge of the wafer tip from breaking when the wafer leaves the chemical liquid tank. It also suppresses the evaporation of the chemical liquid on the wafer surface, improves the problem of tip defect concentration caused by the wafer pulling sequence, and enhances the overall yield of a single wafer and the consistency of yield between batch wafers. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram showing the humidifier starting to work before the wafer leaves the chemical bath, provided in an embodiment of the present invention. Figure 2 for Figure 1 Side view; Figure 3 This is a schematic diagram of the wafer entering the cover according to an embodiment of the present invention; Figure 4 for Figure 3 Side view; Figure 5 A schematic diagram of a wafer defect suppression device provided in an embodiment of the present invention used in a tank-type wet processing equipment for processing wafers; Figure 6 This is a flowchart of a wafer defect suppression method provided in an embodiment of the present invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] In the description of this invention, it should be understood that the terms “comprising” and “having” as used herein, and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0023] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. It should be understood that the term "and / or" as used herein is merely a description of the relationship between related objects, indicating that three relationships may exist; for example, A and / or B can represent: A alone, A and B simultaneously, and B alone. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0025] For wet wafer cleaning machines, there is a difference in wafer position when the wafer enters and leaves the chemical solution tank during the wafer cleaning process. For example, after the wafer finishes cleaning and leaves the chemical solution tank, the top of the wafer contacts the air first, while the bottom of the wafer contacts the air last. On the one hand, the chemical solution adhering to the wafer surface is subjected to the inertial effect of gravity and acceleration, causing the liquid film at the outer edge of the wafer top to rupture. On the other hand, in a dry machine environment, the wafer top comes into contact with the air first, resulting in the most severe chemical evaporation and causing chemical solutes to dry and adhere to the wafer surface. Under the influence of these two problems, the top edge area of ​​the wafer becomes a weak point in the entire wafer during the pulling process, thus generating defects with specific locations. Existing technologies have not effectively solved the problem of defects generated at the wafer top edge due to the combined effect of local liquid film rupture and rapid local chemical evaporation during the critical transition stage when the wafer leaves the chemical solution tank. This application provides a wafer defect suppression device, method, and wet wafer cleaning equipment based on the above problems.

[0026] The wafer defect suppression device, method, and tank-type wet processing equipment provided by the present invention will be described in detail below with reference to specific embodiments.

[0027] Figure 1 This is a schematic diagram showing the humidifier starting to operate before the wafer leaves the chemical bath, provided in an embodiment of the present invention. Figure 2 for Figure 1 Side view, Figure 3 This is a schematic diagram of the wafer after it enters the cover according to an embodiment of the present invention. Figure 4 for Figure 3 For a side view, please refer to Figures 1-4 A first aspect of the present invention provides a wafer defect suppression device 1 for use in a tank-type wet processing apparatus 2. The tank-type wet processing apparatus 2 includes a chemical liquid tank 21 for holding chemical liquid. The wafer defect suppression device 1 includes a humidifier 11 and a cover 12. The humidifier 11 includes a liquid supply section, which is connected to the chemical liquid tank 21. The humidifier 11 is used to atomize the chemical liquid to generate a humid atmosphere with the same composition as the chemical liquid in the chemical liquid tank 21. The cover 12 is used to guide and maintain the humid atmosphere on a preset transfer path of the wafer, so that the wafer surface is surrounded by the humid atmosphere for a period of time after leaving the chemical liquid tank 21.

[0028] The tank-type wet processing equipment of this embodiment refers to a device used in industries such as semiconductors, flat panel displays, and photovoltaics, which performs specific surface treatment functions by immersing wafers in a tank containing liquid chemical solutions. Exemplarily, the tank-type wet processing equipment of this embodiment is a tank-type wet etching machine. The chemical solution tank is the core functional unit of the tank-type wet processing equipment, referring to the container that directly holds the liquid chemical solution used to process the wafers and immerses the wafers within it.

[0029] The humidifier 11 in this embodiment includes a liquid supply unit 111, which is connected to the chemical liquid tank 21 below via a pipe 112 to form a liquid supply system. Its function is to atomize the chemical liquid, converting the liquid chemical solution into an aerosol state to generate a humid atmosphere. In one embodiment, the liquid supply unit can be a small pump or utilize a siphon principle to draw the chemical solution from the chemical liquid tank 21 in real time. The humid atmosphere generated by the humidifier 11 maintains the same chemical composition and concentration as the process solution in the chemical liquid tank 21, avoiding the introduction of external contamination or concentration differences. The cover 12 is a physical structure with a specific shape. Its function is not to completely seal, but rather to guide and maintain the humid atmosphere generated by the humidifier 11. Specifically, the cover can be designed as an inverted U-shape, an arch, or a partially enclosed channel. The cover gathers and confines the humid atmosphere generated by the humidifier 11 around the wafer, effectively slowing down the convection exchange between the atmosphere and the external drying environment, thereby extending the time the humid atmosphere surrounds the wafer surface.

[0030] In this embodiment, when the wafer is about to complete its processing (such as cleaning or etching) in the chemical bath 21, the control system will activate the humidifier 11 in advance (or at the moment the wafer begins to rise). The humidifier 11 draws the chemical solution from the chemical bath 21 and atomizes it, rapidly generating a high-humidity, chemically stable local atmosphere in the area above the bath opening. Almost simultaneously, the cover 12 moves directly above the wafer. As the robotic arm lifts the wafer along a preset transfer path, the humid atmosphere inside the cover 12 continuously surrounds the wafer surface. Since the atmosphere and the liquid film on the wafer surface have the same chemical composition, when the liquid film at the top of the wafer thins due to gravity, the evaporation of solvent on its surface is greatly suppressed, and moisture can be slightly replenished from the surrounding humid atmosphere, thereby avoiding instantaneous breakage of the liquid film. At the same time, since the evaporation of chemical solutes is also suppressed, the concentration and drying of solutes at the edge of the wafer top are effectively prevented. The wafer defect suppression device 1 in this embodiment can also ensure that the surface of the wafer is surrounded by a liquid film before the wafer enters the chemical bath 21.

[0031] The wafer defect suppression device in this embodiment provides a smooth transition environment for the liquid film attached to the wafer surface from full immersion to exposure to dry air, avoiding physical liquid film rupture caused by gravity flow and surface tension imbalance. By creating a high-humidity environment that is of the same origin as the chemical liquid in the chemical bath, it effectively reduces the evaporation rate of the chemical liquid in the liquid film, prevents dry stain defects caused by local concentration and crystallization of solute, and solves the problem of defect concentration at the top (the first part to leave the liquid surface) caused by the wafer pulling sequence, thereby improving the overall yield of a single wafer and the consistency of yield between batch wafers. Since the wafer defect suppression device uses the original solution in the chemical bath for humidification, it does not introduce new chemical substances, does not interfere with the original process formula, and has strong compatibility.

[0032] In this embodiment, the humidifier 11 is an ultrasonic humidifier 11, whose liquid supply section 111 is connected to the chemical liquid tank 21, and is used to atomize the chemical liquid taken from the chemical liquid tank 21 into micron-sized droplets. Specifically, the humidifier 11 is an ultrasonic humidifier 11. Its liquid supply section is connected to the chemical liquid tank 21, and its atomization core utilizes high-frequency ultrasonic vibration (e.g., 1.7MHz or 2.4MHz) to agitate the liquid surface, causing the chemical liquid to break into uniform micron-sized (e.g., 1-5 microns) droplets and spray them out to form an aerosol. In this embodiment, the ultrasonic transducer of the ultrasonic humidifier 11 generates high-frequency mechanical vibration, which is transmitted to the chemical liquid, generating cavitation effect and capillary waves on the liquid surface, directly processing the liquid into fine droplets. This results in high energy efficiency and uniform, controllable droplet size. Compared with heating evaporative humidification, the ultrasonic humidifier 11 in this embodiment does not change the chemical properties of the liquid (no risk of thermal decomposition), has a fast atomization speed, can instantly establish the required atmosphere, and the micron-sized droplets are easy to diffuse with the airflow and adhere to the wafer surface, resulting in better liquid film replenishment.

[0033] In this embodiment, the cover 12 is connected to or integrally formed with the ultrasonic humidifier 11, and the interior of the cover 12 forms part or all of the preset transfer path. For example, the mist outlet of the humidifier 11 is directly integrated into the top or side wall of the cover 12, and the internal cavity of the cover 12 constitutes a critical protective section of the wafer transfer path. A humid atmosphere is generated and filled inside the cover 12, forming an independent microenvironment. The integrated design of the cover 12 and the ultrasonic humidifier 11 shortens the atmosphere transmission path, reducing atmosphere loss and temperature changes before reaching the wafer. The integrated structure of the cover 12 and the ultrasonic humidifier 11 in this embodiment improves system integration and space utilization efficiency, ensuring that the humid atmosphere acts on the wafer via the shortest path, resulting in a faster response and more direct effect.

[0034] Furthermore, the enclosure 12 is made of materials with excellent resistance to acid and alkali corrosion (such as polytetrafluoroethylene and polyvinylidene fluoride). In wet processing, the atmosphere may contain vapors or droplets of highly corrosive chemicals such as HF, H3PO4, and H2SO4. Materials such as polytetrafluoroethylene and polyvinylidene fluoride have excellent chemical inertness, ensuring that the enclosure 12 maintains its structural integrity, does not corrode, and does not release pollutants in a long-term highly corrosive environment, thus ensuring the long-term reliable operation of the equipment and maintaining process cleanliness.

[0035] Furthermore, the wafer defect suppression device 1 in this embodiment also includes a driving mechanism connected to the cover 12, used to drive the cover 12 to move along a preset track, the preset track at least covering the area above the opening of the chemical liquid tank 21. Exemplarily, the driving mechanism is a linear motor, a servo motor with a lead screw, or a synchronous belt module. This driving mechanism is connected to the cover 12 and drives it to move along a preset track, the track at least covering the area above the opening of the chemical liquid tank 21. This embodiment uses program control of the driving mechanism, enabling the cover 12 to move precisely into position or make way according to the process cycle, achieving automated operation. This allows for seamless integration into existing tank-type equipment timing control without manual intervention, improving production efficiency.

[0036] Figure 5 This embodiment of the invention provides a schematic diagram of a wafer defect suppression device used in a tank-type wet processing equipment for processing wafers. The preset track includes a first position A for covering the tank opening and a second position B for providing space for wafer lifting and lowering. The driving mechanism drives the cover 12 to reciprocate between the first position A and the second position B. In this embodiment, the preset track defines the first position A and the second position B. The first position A is the working position, where the cover 12 covers the tank opening. The second position B is the clearance position; when the cover 12 moves to the second position B, it provides vertical space for wafer immersion and lifting. When the wafer needs to be immersed or completely removed, the cover 12 moves to the second position B. When the wafer is being processed in the tank or about to be lifted, the cover 12 moves to the first position A and begins operation. This embodiment, through its reciprocating motion design, maximizes the saving of top space on the equipment while ensuring functionality, avoiding interference with robotic arms or other equipment, making the device easy to retrofit onto existing equipment. In this embodiment, the first position A corresponds to the chemical liquid tank of the tank-type wet processing equipment, and the second position B corresponds to the deionized water tank.

[0037] Exemplarily, the tank-type wet processing equipment in this embodiment is a tank-type wet etching machine. The wafer defect suppression device in this embodiment is used in the wafer wet etching process as follows: When the wafer is about to arrive at the chemical solution tank 21, the cover 12 moves along the track from the first position A to the second position B, leaving space to wait for the wafer to arrive; after the wafer enters the chemical solution tank 21, the cover 12 moves along the track from the second position B to the first position A, waiting for the wet etching process to be completed. The ultrasonic humidifier 11 starts working before the wet etching process is completed, generating a humid atmosphere; the wafer is lifted by the arm and enters the humid chemical solution environment. The speed of the cover 12 moving along the track is consistent with the speed of the arm carrying the wafer; the cover 12 and the wafer arm move from the first position A to the second position B; the wafer enters the next processing tank, the ultrasonic humidifier 11 stops working, and the cover 12 returns along the track to the first position A to prevent the wafer coming out of the cleaning tank at the second position B from being affected by the chemical solution environment inside the cover. The ultrasonic humidifier 11 waits for the next batch of products.

[0038] Preferably, the ultrasonic humidifier 11 has an adjustable operating frequency to generate chemical liquid droplets of different sizes. For example, the adjustable operating frequency of the ultrasonic humidifier 11 can be adjusted within the range of 1.0 MHz to 3.0 MHz. The ultrasonic frequency directly affects the particle size of the atomized droplets; the higher the frequency, the smaller the average droplet size (e.g., 1.7 MHz produces 3-5 micrometers, 2.4 MHz produces 1-3 micrometers). For chemical liquids with different viscosities and surface tensions, the frequency can be adjusted to obtain the best atomization effect. Smaller droplets have better diffusion and are suitable for quickly establishing an atmosphere, while slightly larger droplets have slightly stronger settling properties and may provide more direct replenishment to the liquid film. In this embodiment, the adjustable operating frequency of the humidifier 11 enhances the process adaptability of the device.

[0039] This invention provides a smooth transition environment for the liquid film attached to the wafer surface, from full immersion to exposure to dry air. This avoids physical liquid film rupture caused by gravity flow and surface tension imbalance. By creating a high-humidity environment that is homologous to the chemical solution in the chemical bath, the evaporation rate of the chemical solution in the liquid film is effectively reduced, preventing dry stain defects caused by local concentration and crystallization of the solute. This solves the problem of defect concentration at the top (the first part to leave the liquid surface) caused by the wafer pulling sequence, improving the overall yield of a single wafer and the consistency of yield between batch wafers. Since this wafer defect suppression device uses the original solution in the chemical bath for humidification, it does not introduce new chemical substances, does not interfere with the original process formula, and has strong compatibility.

[0040] Figure 6 For a flowchart of the wafer defect suppression method provided in an embodiment of the present invention, please refer to [link / reference]. Figures 1-6A second aspect of the present invention provides a wafer defect suppression method, using a wafer defect suppression device for a tank-type wet processing equipment as described in the above embodiments, the wafer defect suppression method comprising the following steps: S101. Before or at the same time as the wafer completes the in-cell process and is about to leave the chemical solution surface, start the humidifier to create a humid atmosphere above the wafer. Specifically, after the wafer completes the preset cleaning or etching process in the chemical bath 21, the equipment control system (such as a PLC or dedicated controller) sends a start signal to the humidifier 11 (such as an ultrasonic humidifier) ​​according to a preset program, hundreds of milliseconds to several seconds before the robotic arm begins to execute the instruction to lift the wafer, or precisely at the same moment the lifting instruction is issued. Once activated, the humidifier 11's liquid supply unit 111 immediately draws process solutions from the current chemical bath and converts the solutions into fine mist aerosols through its atomization mechanism (such as ultrasonic vibration). These droplets rapidly diffuse upwards and outwards, forming a stable humid atmosphere in the area directly above the opening of the chemical bath 21.

[0041] S102. Control the cover to move above the wafer, so that the surface of the wafer is continuously covered by the humid atmosphere as it rises and leaves the chemical bath. Specifically, at the same time as or shortly after the humidifier 11 is activated and a humid atmosphere begins to form, the control system issues a command to drive the drive mechanism (such as a linear motor module) connected to the enclosure 12. The enclosure 12 moves quickly and smoothly from the yielding position (position B) to the working position along a preset track. This working position is set such that when the enclosure is in place, its internal cavity can completely accommodate the rising wafer, and the lower edge of the enclosure 12 is as close as possible to (but does not contact) the liquid surface or the edge of the chemical tank 21. As the robotic arm lifts the wafer at a uniform speed, the wafer is pulled out from under the liquid surface, and its movement trajectory is completely enveloped within the space defined by the enclosure 12.

[0042] S103. Maintain the humid atmosphere until the wafer is transferred to the next process module or drying area.

[0043] Specifically, this step is the continuation and termination phase of the protection process. After the wafer is completely removed from the surface of the chemical bath 21, until it is horizontally moved out of the current tank area by the robotic arm and prepared for immersion in the next process tank (such as a deionized water rinsing tank) or into the inlet of a drying module (such as a centrifugal dryer), the humidifier 11 continues to operate, and the cover 12 remains enveloping the wafer. The control system may continuously and synchronously move the cover 12, or keep it in a fixed position until the wafer is removed, depending on the speed and position of the wafer transport. When the front end of the wafer (in the horizontal direction of movement) is about to enter a different process environment (e.g., about to be immersed in a large amount of deionized water), the control system sequentially executes: turning off the humidifier 11 to stop mist generation; driving the cover 12 to move away, returning to its initial yielding position, preparing for the processing of the next wafer.

[0044] In existing wet wafer processing equipment, when the wafer leaves the chemical bath, the chemical film adhering to the wafer surface is subject to several challenges. First, the liquid film at the outer edge of the wafer tip is prone to breakage due to gravity and inertia caused by acceleration. Second, in dry environments, the wafer tip is the first to come into contact with air, leading to the most significant chemical evaporation and the potential for chemical residue to dry and adhere to the wafer surface. This wafer defect suppression method utilizes a pre- and continuously supplied homogeneous humid atmosphere to create an intermediate buffer layer between the liquid film and the external environment. This ensures the liquid film remains in a high-humidity gaseous environment throughout its thinning process, guaranteeing its integrity and fundamentally eliminating defects that could be introduced by physical rupture of the liquid film. This wafer defect suppression method creates a humid atmosphere consistent with the chemical composition in the chemical bath, reducing the vapor pressure difference between the liquid film on the wafer surface and the surrounding environment. This transforms the evaporation mode of the chemical substances into slow diffusion, allowing the effective components in the chemical solution to remain dissolved and move uniformly with the liquid film. This effectively prevents solute concentration, crystallization, and irreversible dry residue caused by rapid evaporation at the wafer tip edge, avoiding pattern defects or electrical failures caused by such residues.

[0045] Furthermore, when the wafer is about to enter the chemical solution bath, the cover 12 is controlled to move to a clearance position; after the wafer is fully immersed in the chemical solution, the cover 12 is controlled to move to a position covering the opening of the chemical solution bath. For example, as... Figure 5 As shown, in this embodiment, when the wafer reaches above the chemical solution tank 21, the cover 12 is located at the second position B. During the wafer immersion process, the cover 12 remains in a yielding position. After the wafer is completely submerged, the cover 12 moves to the first position A (covering the opening of the chemical solution tank). This embodiment can prevent the cover 12 from interfering with the wafer immersion. During wafer processing, the cover 12 covering the chemical solution tank 21 can reduce the total amount of chemical solution volatilized from the tank into the machine environment, which saves chemical solution and improves the working environment.

[0046] Furthermore, during the wafer's ascent, the movement speed of the cover is synchronized with the movement speed of the wafer to maintain a stable relative position between the cover and the wafer. This embodiment employs precise speed control of the drive mechanism, ensuring that the speed at which it drives the cover 12 upwards is completely synchronized with the speed at which the robotic arm lifts the wafer. The relative distance between the wafer and the inner top wall of the cover 12 remains constant, forming a relatively stable air gap. This optimally maintains the stability of the atmosphere within the cover 12, preventing airflow disturbances caused by excessive relative movement from damaging the liquid film and achieving a better protective effect.

[0047] This embodiment provides a transitional environment with a complete liquid film and controlled evaporation for the wafer from a fully immersed state to a dry state by controlling the operating parameters of the humidifier. For example, this embodiment precisely controls the humidity level, droplet density, and duration of the transitional environment by comprehensively adjusting the humidifier's power (controlling the atomization amount), frequency (controlling the droplet size), and the start-up timing of the humidifier 11 in step S101.

[0048] The wafer defect suppression method of this embodiment can ensure that all areas of the wafer, especially the top area which is traditionally exposed first, are protected when leaving the chemical bath. This improves the problem of defects being concentrated in specific locations (top / edge) on the wafer, and significantly reduces the defect rate introduced by the pulling process, thereby greatly improving the overall yield of a single wafer and the consistency of yield between batch wafers.

[0049] A third aspect of the present invention provides a tank-type wet processing apparatus, including a chemical liquid tank and a wafer transfer mechanism, and further including a wafer defect suppression device as described in the above embodiments.

[0050] For example, a wafer defect suppression device includes a humidifier and a cover. The humidifier includes a liquid supply section that is connected to the chemical liquid tank. The humidifier is used to atomize the chemical liquid to generate a humid atmosphere that is consistent with the composition of the chemical liquid in the chemical liquid tank. The cover is used to guide and maintain the humid atmosphere on a preset transfer path of the wafer, so that the wafer surface is surrounded by the humid atmosphere for a period of time after leaving the chemical liquid tank.

[0051] The tank-type wet processing equipment of this embodiment refers to a device used in industries such as semiconductors, flat panel displays, and photovoltaics, which performs specific surface treatment functions by immersing wafers in a tank containing liquid chemicals. This tank-type wet processing equipment can be a tank-type wet cleaning machine or a wet etching machine. The chemical tank is the core functional unit of the tank-type wet processing equipment; it refers to a container that directly holds the liquid chemicals used to process the wafers and immerses the wafers within it. The wafer transfer mechanism of this embodiment typically includes one or more robotic arms, with end effectors at the ends of the robotic arms for gripping wafers or carrying wafer carriers. This embodiment of the tank-type wet processing equipment provides a smooth transition environment for the liquid film attached to the wafer surface from full immersion to exposure to dry air, avoiding physical liquid film rupture caused by gravity flow and surface tension imbalance. By creating a high-humidity environment that is of the same origin as the chemical liquid in the chemical tank, it effectively reduces the evaporation rate of the chemical liquid in the liquid film, prevents dry stain defects caused by local concentration and crystallization of solute, and solves the problem of defect concentration at the top (the first part to leave the liquid surface) caused by the wafer pulling sequence, thereby improving the overall yield of a single wafer and the consistency of yield between batch wafers. Since this wafer defect suppression device uses the original solution in the chemical tank for humidification, it does not introduce new chemical substances, does not interfere with the original process formula, and has strong compatibility.

[0052] In the above description, the terms "an embodiment," "some embodiments," "example," "specific example," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0053] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wafer defect suppression device for use in a tank-type wet processing equipment, the tank-type wet processing equipment comprising a chemical solution tank for holding a chemical solution, characterized in that, Wafer defect suppression devices include: A humidifier includes a liquid supply unit connected to the chemical liquid tank, the humidifier being used to atomize the chemical liquid to generate a humid atmosphere consistent with the composition of the chemical liquid in the chemical liquid tank; a cover is used to guide and maintain the humid atmosphere on a preset transfer path of the wafer, so that the wafer surface is surrounded by the humid atmosphere for a period of time after leaving the chemical liquid tank.

2. The wafer defect suppression device according to claim 1, characterized in that, The humidifier is an ultrasonic humidifier, and its liquid supply section is connected to the chemical liquid tank to atomize the chemical liquid taken from the chemical liquid tank into micron-sized droplets.

3. The wafer defect suppression device according to claim 2, characterized in that, The cover is connected to or integrally formed with the ultrasonic humidifier, and part or all of the preset transfer path is formed inside the cover.

4. The wafer defect suppression device according to claim 3, characterized in that, The cover is made of polytetrafluoroethylene or polyvinylidene fluoride.

5. The wafer defect suppression device according to claim 3, characterized in that, It also includes a drive mechanism connected to the cover body for driving the cover body to move along a preset track, the preset track at least covering the area above the opening of the chemical liquid tank.

6. The wafer defect suppression device according to claim 5, characterized in that, The preset track includes a first position for covering the slot and a second position for making room for wafer lifting and lowering. The drive mechanism drives the cover to reciprocate between the first position and the second position.

7. The wafer defect suppression device according to claim 2, characterized in that, The ultrasonic humidifier has an adjustable operating frequency to generate chemical liquid droplets of different sizes.

8. A method for suppressing wafer defects, using the wafer defect suppression device as described in any one of claims 1-7, characterized in that, The wafer defect suppression method includes the following steps: The humidifier is activated before or at the same time the wafer completes its in-cell processing and is about to leave the chemical solution surface to create a humid atmosphere above the wafer. The cover is controlled to move above the wafer, so that the surface of the wafer remains under the humid atmosphere as it rises and leaves the chemical bath. Maintain the humid atmosphere until the wafer is transferred to the next process module or drying area.

9. The wafer defect suppression method according to claim 8, characterized in that, Before starting the humidifier, the following are also included: When the wafer is about to enter the chemical solution tank, the cover is controlled to move to a clearance position; after the wafer is completely immersed in the chemical solution, the cover is controlled to move to a position that covers the opening of the chemical solution tank.

10. The wafer defect suppression method according to claim 8, characterized in that, During the wafer's ascent, the movement speed of the cover is controlled to be synchronized with the movement speed of the wafer to maintain the relative position of the cover and the wafer stable.

11. A tank-type wet processing equipment, comprising a chemical solution tank and a wafer transfer mechanism, characterized in that, It also includes a wafer defect suppression device as described in any one of claims 1-7.

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