A megasonic water delivery device and megasonic cleaning system

Abstract

The present disclosure provides a megasonic water area conducting device and a megasonic cleaning system. The megasonic water area conducting device includes a water area tank, two branch pipes inside the water area tank, each branch pipe is formed with a series of openings arranged in a straight line along the longitudinal direction of the branch pipe, liquid flows into the water area tank through the openings, wherein the two branch pipes are arranged symmetrically about a neutral plane of the water area tank, and the two branch pipes are arranged such that the liquid flowing out of each branch pipe flows in an obliquely upward manner towards the intersection line between the neutral plane and the overflow plane of the water area tank. The megasonic water area conducting device can form a liquid stratosphere near the liquid surface, thereby inhibiting turbulent flow, and can quickly discharge the bubbles occasionally formed on the liquid surface from the water area tank.

Description

Technical Field

[0001] This disclosure relates to the field of semiconductor wafer manufacturing, and more particularly to a mega-acoustic water conduction device and a mega-acoustic cleaning system. Background Technology

[0002] In the semiconductor wafer manufacturing industry, wafer cleaning is a crucial step. During manufacturing, wafers come into contact with various chemicals and particulate matter; if these substances are not thoroughly removed, they will severely impact the performance and reliability of the devices. Therefore, the cleaning process must not only remove physical and chemical contaminants from the wafer surface but also ensure that no new contamination is introduced. As semiconductor device sizes continue to shrink and integration levels increase, the requirements for wafer surface cleanliness are becoming increasingly stringent, making advancements in cleaning technology essential for the continued development of the semiconductor industry.

[0003] Currently, megasonic cleaning technology is widely used in wafer fabrication cleaning processes within the semiconductor industry. Megasonic cleaning utilizes the cavitation effect generated by ultrasound in a liquid, causing tiny bubbles to continuously form, grow, and burst under the influence of the ultrasound. This process generates strong impact forces and microjets, which strike the semiconductor surface, stripping contaminants from the surface and dispersing them into the cleaning solution, thus achieving the cleaning purpose. Due to its high efficiency, environmental friendliness, and adaptability, megasonic cleaning technology has been widely applied in the semiconductor cleaning field.

[0004] While megasonic cleaning technology has achieved some success in the semiconductor cleaning field, several challenges remain. Because megasonic cleaning relies on water conduction, the presence of bubbles or turbulence at the interface between the water and the tank can affect the uniformity of the megasonic waves within the tank, thus impacting the cleaning effect. Bubbles and turbulence lead to uneven distribution of megasonic energy, weakening cleaning capabilities and potentially damaging the wafer surface. Furthermore, unstable water flow can cause redeposition of contaminants in the water, reducing megasonic conduction efficiency. Therefore, controlling the water flow in the tank to laminar flow while minimizing or rapidly removing bubbles is crucial for improving megasonic cleaning performance. This not only affects cleaning quality but also production costs and efficiency. Summary of the Invention

[0005] This disclosure provides a mega-sound water conduction device and a mega-sound cleaning system, which can form a liquid advection layer near the liquid surface to suppress turbulence and can quickly discharge bubbles that occasionally form on the liquid surface from the water tank.

[0006] The technical solution disclosed herein is implemented as follows:

[0007] In a first aspect, this disclosure provides a mega-sound water conduction device, the mega-sound water conduction device comprising:

[0008] Water tank;

[0009] The water tank contains two branch pipes, each with a series of openings arranged in a straight line along its longitudinal direction. Liquid flows into the water tank through these openings.

[0010] The two branch pipes are arranged symmetrically with respect to the neutral plane of the water tank, and the two branch pipes are configured such that the liquid leaving each branch pipe flows obliquely upward toward the line of intersection between the neutral plane and the overflow plane of the water tank.

[0011] In some optional examples, the angle between the direction of liquid flow leaving each branch pipe and the central facade is between 40° and 50°.

[0012] In some optional examples, the upper edge of the water tank is in the same horizontal plane.

[0013] In some optional examples, the upper edge is formed with a series of V-shaped grooves of the same depth.

[0014] In some optional examples, the series of V-grooves are evenly distributed along the upper edge.

[0015] In some optional examples, the megaphonic water conduction device also includes a mounting bracket for mounting the two branch pipes inside the water tank.

[0016] In some optional examples, the two branch pipes are made of perfluoroalkoxyethylene.

[0017] In some optional examples, the megaphonic water conduction device also includes a main pipe through which liquid from a liquid source flows to the two branch pipes, the main pipe and the branch pipes being connected to each other by heat-shrinkable connections.

[0018] In some optional examples, the megaphonic water conduction device further includes a control valve disposed on the main pipe for regulating the flow rate of the liquid flowing in the main pipe.

[0019] Secondly, this disclosure provides a megaphonic cleaning system, the megaphonic cleaning system comprising:

[0020] According to the mega-sound water conduction device described in the first aspect;

[0021] Megasonic wave generator;

[0022] Quartz tank, the quartz tank being used to hold the wafers to be cleaned.

[0023] The megasonic waves emitted by the megasonic wave generator are transmitted to the quartz tank via the megasonic water conduction device to clean the wafer.

[0024] This disclosure provides a megasonic water tank conduction device and a megasonic cleaning system. When the water tank is filled with liquid, it effectively suppresses the interference of turbulence and air bubbles on the megasonic cleaning process, thereby improving the cleaning effect. Because the liquid leaving each branch pipe flows obliquely upwards towards the intersection line between the central surface and the overflow plane, this helps to form a horizontal liquid advection layer near the liquid surface, flowing horizontally from the central surface to both sides. This advection layer effectively avoids turbulence caused by violent liquid movement, reduces interference with the megasonic waves, maintains the uniformity of the megasonic waves, and thus improves the cleaning effect. When the liquid overflows from the water tank, the air bubbles formed on the liquid surface quickly reach the edge of the water tank with the liquid advection layer and leave the water tank with the overflowing liquid. This process avoids air bubbles interfering with the megasonic waves, affecting the uniformity of the megasonic waves, and thus affecting the cleaning effect. The rapid discharge of air bubbles reduces instability during the cleaning process and improves the consistency of the cleaning. Liquid flows into the water tank through multiple openings, making the flow velocity moderate and reducing the occurrence of turbulence. The gentle flow of the liquid helps maintain the stability of the liquid within the water tank, further ensuring the uniform transmission of megasonic waves. Simultaneously, larger particles of impurities in the liquid are quickly discharged from the water tank. Once these impurities enter the liquid stratosphere, they reach the edge of the water tank with the stratosphere and leave with the overflowing liquid, thus reducing their impact on megasonic wave transmission. This rapid discharge mechanism helps maintain the cleanliness of the liquid within the water tank and improves the transmission efficiency of megasonic waves. The two branch pipes are arranged symmetrically with respect to the neutral plane of the water tank; this symmetry helps maintain the stability and uniformity of the liquid flow. The symmetrical arrangement of the branch pipes ensures that the liquid flows into the water tank uniformly from both directions, enhancing the stability of the liquid flow. Through this design, the megasonic water tank transmission device provided in this embodiment optimizes liquid flow, reduces turbulence and bubble generation, and quickly discharges bubbles and large particles of impurities, thereby improving the uniformity and efficiency of megasonic cleaning and ensuring the stability of the cleaning process and the consistency of the cleaning effect. Attached Figure Description

[0025] Figure 1 This is a front cross-sectional schematic diagram of a mega-sound water conduction device provided in an embodiment of this disclosure.

[0026] Figure 2 This is a top view schematic diagram of a megaphonic water conduction device provided in an embodiment of this disclosure.

[0027] Figure 3This is a front view schematic diagram of the water tank of the megaphonic water conduction device provided in an embodiment of this disclosure.

[0028] Figure 4 This is a front cross-sectional schematic diagram of a megaphonic water conduction device provided in another embodiment of the present disclosure.

[0029] Figure 5 This is a top view schematic diagram of a megaphonic water conduction device provided for another embodiment of this disclosure. Detailed Implementation

[0030] The technical solutions in this disclosure will now be clearly and completely described with reference to the accompanying drawings.

[0031] In semiconductor manufacturing, wafer cleaning is a critical step in ensuring product quality. Wafers inevitably come into contact with various chemicals and particles during production. If these residues are not thoroughly removed, they will directly affect the performance and reliability of the final product. Therefore, the cleaning process must not only completely remove contaminants from the wafer surface but also ensure that no new sources of contamination are introduced. As semiconductor devices become smaller and more integrated, the requirements for wafer cleanliness also increase. Advances in cleaning technology are of great significance to the sustainable development of the semiconductor industry.

[0032] In the current semiconductor industry, megasonic cleaning technology is widely used in wafer cleaning processes. This technology utilizes the cavitation effect generated by ultrasound in a liquid, causing tiny bubbles in the liquid to form, grow, and eventually burst under the action of ultrasound, generating strong impact forces and microjets. These impact forces and microjets can impact the semiconductor surface, peeling off contaminants from the surface and dispersing them into the cleaning solution, thus achieving the cleaning purpose. Due to its high efficiency, environmental friendliness, and strong adaptability, megasonic cleaning technology has become the mainstream technology in the semiconductor cleaning field.

[0033] However, despite the achievements of megasonic cleaning technology, several challenges remain in practical applications. Megasonic cleaning relies on water conduction; the presence of air bubbles or turbulence at the interface between the water and the cleaning tank will affect the uniformity of megasonic waves within the tank, thus impacting the cleaning effect. Air bubbles and turbulence can lead to uneven distribution of megasonic energy, reducing cleaning capacity and potentially damaging the wafer surface. Furthermore, unstable water flow can cause redeposition of contaminants in the cleaning solution, reducing megasonic conduction efficiency. Therefore, controlling the water flow within the cleaning tank to maintain laminar flow and reduce or rapidly remove air bubbles is crucial for improving megasonic cleaning performance. This not only affects cleaning quality but also production costs and efficiency.

[0034] To address the problems existing in the prior art, this disclosure proposes a megasonic water conduction device, which aims to improve the uniformity and efficiency of megasonic cleaning by improving the structural design of the water tank, optimizing the liquid flow state, and reducing the influence of bubbles and turbulence.

[0035] Specifically, see Figure 1 and Figure 2 This disclosure provides a megaphonic water conduction device 10, which may include a water tank 11 and two branch pipes 12 inside the water tank 11.

[0036] Each branch pipe 12 has a series of openings 12A arranged in a straight line along its longitudinal direction. Liquids that conduct mega-sound waves, such as water, flow into the water tank 11 through the openings 12A. Figure 1 The area filled with dots schematically illustrates the liquid filling the water tank 11. The above-mentioned "arranged in a straight line" means that a series of openings 12A are formed in the same circumferential direction of the branch pipe 12, or that the series of openings 12A are not arranged longitudinally along the branch pipe 12 but rotate circumferentially in the branch pipe 12 to form a spiral shape as a whole.

[0037] The two branch pipes 12 are arranged symmetrically about the mid-plane MP of the water tank 11, where the mid-plane MP refers to the vertical plane that divides the water tank 11 into two equal parts, for example, in... Figure 1 and Figure 2 In the case that the water tank 11 shown is a cube, the mid-face MP can be as follows: Figure 1 and Figure 2 The plane, schematically shown by the dashed line segment, passes through the midline of the bottom surface of the water tank 11 and is perpendicular to the bottom surface of the water tank 11. The two branch pipes 12 are arranged such that the liquid leaving each branch pipe 12, i.e., the liquid flowing out from the aforementioned opening 12A, flows obliquely upwards towards the intersection line CL between the central elevation MP and the overflow plane SP of the water tank 11, as shown in... Figure 1 The diagram is schematically shown using solid line segments with arrows. In this case, it can be inferred that both branch pipes 12 need to be arranged horizontally and parallel to each other. Furthermore, the overflow plane SP of the water tank 11 refers to the liquid level when liquid overflows from the water tank 11. Additionally, the aforementioned intersection line CL... Figure 1 The front view is schematically shown using a cross symbol. Figure 2 In the top view, it is schematically shown by solid line segments, which can be understood as... Figure 2 In the top view, the intersecting line CL coincides with the mid-level plane MP.

[0038] First, when the water tank 11 is filled with liquid, since the liquid leaving each branch pipe 12 flows obliquely upward toward the intersection line CL between the central facade MP and the overflow plane SP of the water tank 11, this helps to form a horizontal liquid advection layer near the liquid surface, or the surface layer of the liquid, flowing horizontally from the central facade MP toward both sides of the central facade MP, such as... Figure 1 and Figure 2 As shown by the dashed line with arrows, such a stratosphere can effectively suppress turbulence caused by violent liquid movement, effectively avoid the occurrence of liquid turbulence in the water tank 11, reduce interference with megasonic waves, thereby maintaining the uniformity of megasonic waves used for cleaning wafers and improving the cleaning effect.

[0039] Secondly, when the liquid overflows in the water tank 11, bubbles B that occasionally form on the liquid surface will quickly reach the edge of the water tank 11 along with the aforementioned liquid advection layer, and then leave the water tank 11 with the overflowing liquid. This process prevents bubbles B from interfering with the megasonic waves, affecting the uniformity of the megasonic waves used for wafer cleaning, and thus affecting the cleaning effect. Figure 1 As shown, the rapid discharge of bubble B reduces instability during the cleaning process.

[0040] Furthermore, since the liquid flows into the water tank 11 through multiple openings 12A, the flow rate becomes gentle, reducing the occurrence of turbulence. The gentle flow of the liquid helps maintain the stability of the liquid in the water tank 11, further ensuring the uniform transmission of megason waves.

[0041] Furthermore, larger particulate impurities in the liquid are discharged from the water tank 11 more quickly. Once these impurities enter the liquid stratosphere, they travel with it to the edge of the water tank 11 and leave with the overflowing liquid, thus reducing their impact on megasonic wave propagation. This rapid discharge mechanism helps maintain the cleanliness of the liquid within the water tank 11 and improves the propagation efficiency of megasonic waves.

[0042] Finally, the two branch pipes 12 are arranged symmetrically about the mid-plane MP of the water tank 11. This symmetry helps maintain the stability and uniformity of the liquid flow. Figure 1 and Figure 2 As shown, the symmetrically arranged branch pipes 12 ensure that the liquid flows into the water tank 11 evenly from both directions, enhancing the stability of the liquid flow.

[0043] In some embodiments of this disclosure, see Figure 1 The angle α between the direction of liquid flow leaving each branch pipe 12 and the central plane MP can be between 40° and 50°.

[0044] This specific angle range is beneficial for the liquid to flow obliquely upwards when leaving the branch pipe 12, which helps maintain the uniformity of liquid flow in the water tank 11 and helps the liquid form a stable advection layer in the water tank 11, thereby reducing turbulence and bubble formation, reducing the energy loss of megasonic waves during propagation, and allowing more energy to act on the wafer surface, thereby improving the cleaning effect.

[0045] In some embodiments of this disclosure, see Figure 2 and combined Figure 1 The upper edge 11E of the water tank 11 can be in the same horizontal plane.

[0046] This ensures that when liquid overflows from the water tank 11, the liquid can flow out evenly from every point on the upper edge 11E. For example... Figure 1 As shown, this uniform overflow design helps maintain the stability of the liquid within the water tank 11, preventing liquid fluctuations in localized areas due to excessively rapid overflow. More importantly, since the liquid can flow out uniformly from every position along the upper edge 11E, this helps to quickly carry bubbles B and large particulate impurities out of the water tank 11 during liquid overflow, preventing bubbles B and impurities from lingering near the sidewalls of the water tank 11 and reducing their impact on megason wave transmission, thereby improving cleaning efficiency and quality.

[0047] In some embodiments of this disclosure, see Figure 3 The upper edge 11E of the water channel 11 can be formed with a series of V-shaped grooves 11G with the same depth of indentation.

[0048] This allows the overflow function to be activated even with a low water level difference. Even if the water level in the tank is only slightly above the normal level, the V-shaped groove 11G can quickly guide water into the overflow system, improving the sensitivity and reliability of the overflow. More importantly, this instantaneous response characteristic of the V-shaped groove 11G helps maintain the smoothness of liquid flow and the stability of the liquid surface within the water tank 11, promoting the uniform transmission of megasonic waves and maintaining consistency during the megasonic cleaning process.

[0049] In some embodiments of this disclosure, see Figure 3 A series of V-shaped grooves 11G can be evenly distributed along the upper edge 11E.

[0050] The uniform distribution of the V-shaped grooves 11G helps optimize the flow characteristics of the liquid within the water tank 11. This design allows the liquid to be evenly dispersed along the upper edge 11E during overflow, reducing turbulence and pressure imbalances that may be caused by concentrated liquid outflow at a single point. This maintains the uniformity and stability of the liquid flow and prevents liquid fluctuations in localized areas due to excessively rapid overflow.

[0051] In some embodiments of this disclosure, see Figure 4 The mega-sound water conduction device 10 may also include a mounting bracket 13 for mounting two branch pipes 12 inside the water tank 11.

[0052] With the use of mounting bracket 13, the two branch pipes 12 are securely installed inside the water tank 11, ensuring the fixed position of the branch pipes 12 and preventing displacement caused by external forces or liquid flow, thereby guaranteeing the stability and reliability of the entire device. The use of mounting bracket 13 ensures the accuracy of the outflow angle of the liquid. The fixed installation of the branch pipes 12 allows for precise control of the angle at which the liquid flows out from the opening 12A, which is crucial for forming a suitable liquid advection layer and reducing turbulence. Precise control of the liquid outflow angle helps improve the uniformity of megasonic waves in the water tank 11. Due to the secure installation of the branch pipes 12, the liquid can flow out at a predetermined angle, forming a uniform advection layer, thereby allowing the megasonic waves to act uniformly on the wafer surface and improving the cleaning effect.

[0053] In some embodiments of this disclosure, the two branch pipes 12 may be made of perfluoroalkoxyethylene (PFA).

[0054] PFA material is particularly suitable for applications requiring high temperature and corrosion resistance, especially in semiconductor manufacturing and the chemical industry. The low coefficient of friction of PFA helps reduce resistance to liquid flow, thereby lowering energy consumption. This characteristic positively impacts the efficiency of megasonic cleaning and reduces operating costs. The highly smooth surface of PFA prevents contaminant adhesion, helping to maintain the cleanliness of the cleaning fluid, reducing cross-contamination during the cleaning process, and improving cleaning quality. The aging resistance of PFA prevents it from aging and becoming embrittled over long-term use, which helps extend the service life of branch pipe 12, reducing replacement frequency and maintenance costs.

[0055] In some embodiments of this disclosure, see Figure 5 The mega-sound water conduction device 10 may also include a main pipe 14 through which liquid from the liquid source flows to two branch pipes 12. The main pipe 14 and the branch pipes 12 can be connected to each other by heat shrink connection.

[0056] The main pipe 14 is responsible for transporting liquid from the liquid source to the two branch pipes 12, enabling efficient liquid flow from the main pipe 14 to the branch pipes 12 and ensuring the continuity and stability of the liquid supply. The use of the main pipe 14 allows for more flexible pipe layout; it can be arranged according to the specific location and space constraints of the water tank 11, while the branch pipes 12 can be precisely positioned as needed to achieve optimal liquid flow and megasonic wave transmission. The heat-shrinkable connection between the main pipe 14 and the branch pipes 12 provides a convenient installation and maintenance method. The heat-shrinkable connection not only ensures a tight seal at the connection point but also allows for quick disassembly when maintenance or pipe replacement is required, reducing maintenance time and costs. The use of heat-shrinkable connections enhances the overall system's sealing performance. The connection between the main pipe 14 and the branch pipes 12 is tightly sealed through the shrinkage of the heat-shrinkable material, effectively preventing liquid leakage and ensuring the safety and stability of the system. Furthermore, heat-shrinkable connections are highly adaptable, accommodating different pipe diameters and materials. This connection method allows the main pipe 14 to connect with branch pipes 12 of different sizes and materials, improving compatibility.

[0057] In some embodiments of this disclosure, see Figure 5 The mega-sound water conduction device 10 may also include a control valve 15 disposed on the main pipe 14, the control valve 15 being used to regulate the flow rate of the liquid flowing in the main pipe 14.

[0058] Control valve 15 is used to precisely regulate the flow rate of the liquid flowing in the main pipe 14. This precise control is crucial for maintaining the stability of the liquid in the water tank 11 and the consistency of the megasonic cleaning process. By adjusting the flow rate through control valve 15, the megasonic cleaning effect can be optimized. An appropriate flow rate ensures the formation of a liquid stratigraphic layer while avoiding turbulence and bubble generation caused by excessive flow, thereby improving cleaning efficiency and quality.

[0059] This disclosure also provides a megasonic cleaning system (not shown in the accompanying drawings), which may include:

[0060] The megaacoustic water conduction device 10 according to the foregoing embodiments of this disclosure;

[0061] Megasonic wave generator;

[0062] A quartz tank, used to hold wafers to be cleaned.

[0063] The megasonic wave emitted by the megasonic wave generator is transmitted to the quartz tank through the megasonic water conduction device to clean the wafer.

[0064] The megasonic water conduction device 10 works in conjunction with the megasonic generator to ensure efficient conduction of megasonic waves from the generator to the quartz tank. This efficient conduction guarantees full utilization of megasonic energy, thereby improving cleaning efficiency and effectiveness. The liquid flow rate can be precisely controlled via the control valve 15 and main pipe 14 in the megasonic water conduction device 10, which in turn controls the intensity and distribution of the megasonic waves. This precise control allows for adjustment of the megasonic parameters according to the cleaning requirements of different wafers, achieving precise control of the cleaning process.

[0065] It should be noted that the technical solutions described in this disclosure can be combined arbitrarily as long as they do not conflict.

[0066] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A mega-sound water conduction device, characterized in that, The megaphonic water conduction device includes: Water tank; The water tank contains two branch pipes, each with a series of openings arranged in a straight line along its longitudinal direction. Liquid flows into the water tank through these openings. The two branch pipes are arranged symmetrically with respect to the neutral plane of the water tank, and the two branch pipes are configured such that the liquid leaving each branch pipe flows obliquely upward toward the line of intersection between the neutral plane and the overflow plane of the water tank.

2. The mega-sound water conduction device according to claim 1, characterized in that, The angle between the direction of liquid flow leaving each branch pipe and the central plane is between 40° and 50°.

3. The mega-sound water conduction device according to claim 1, characterized in that, The upper edge of the water tank is in the same horizontal plane.

4. The mega-sound water conduction device according to claim 3, characterized in that, The upper edge has a series of V-shaped grooves with the same depth.

5. The mega-sound water conduction device according to claim 4, characterized in that, The series of V-shaped grooves are evenly distributed along the upper edge.

6. The megaacoustic water conduction device according to any one of claims 1 to 5, characterized in that, The mega-sound water conduction device also includes a mounting bracket for installing the two branch pipes inside the water tank.

7. The megaacoustic water conduction device according to any one of claims 1 to 5, characterized in that, The two branch pipes are made of perfluoroalkoxyethylene.

8. The megaacoustic water conduction device according to any one of claims 1 to 5, characterized in that, The mega-sound water conduction device also includes a main pipe through which liquid from the liquid source flows to the two branch pipes. The main pipe and the branch pipes are connected to each other by heat-shrinkable connections.

9. The mega-sound water conduction device according to claim 8, characterized in that, The mega-sound water conduction device also includes a control valve installed on the main pipeline, which is used to regulate the flow rate of the liquid flowing in the main pipeline.

10. A mega-sound cleaning system, characterized in that, The mega-sound cleaning system includes: The mega-sound water conduction device according to any one of claims 1 to 9; Megasonic wave generator; Quartz tank, the quartz tank being used to hold the wafers to be cleaned. The megasonic waves emitted by the megasonic wave generator are transmitted to the quartz tank via the megasonic water conduction device to clean the wafer.

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