Semiconductor cleaning ultrasonic water tank

Abstract

This application provides an ultrasonic water tank for semiconductor cleaning, relating to the field of semiconductor cleaning technology. It includes a tank body with an ultrasonic module installed at its outer bottom. The tank body has a water outlet, and two inlet pipes are symmetrically connected to the bottom side wall of the tank body. The two inlet pipes are connected by multiple connecting pipes, which are parallel and equally spaced. Multiple water inlet holes are evenly distributed along the length of the top surface of each connecting pipe. A flow equalizer is fixed inside the tank body, located directly above the connecting pipes, and has evenly distributed flow equalizer holes in its center. This application achieves efficient and thorough cleaning without dead angles through a uniform upward fluid distribution working in conjunction with ultrasonic vibration, specifically designed to solve the problem of particle residue at the bottom of wafer trenches. It employs a dual-mode upward water flow cleaning, with the two modes able to be used alternately for better cleaning results. The cleaned wastewater exits the tank body from the outlet, with a stable water flow direction, good cleaning effect, and low risk of secondary pollution.

Description

Technical Field

[0001] This application relates to the field of semiconductor cleaning technology, and in particular to an ultrasonic water tank for semiconductor cleaning. Background Technology

[0002] In semiconductor manufacturing processes, cleaning after various chemical processes is crucial. Currently, the industry standard cleaning process typically uses a simple water tank for overflow rinsing during the final QDR (Quick Dump Rinse) stage. This traditional tank relies on the dynamic force of pure water flow to remove residues from the wafer surface. However, as the feature size of semiconductor devices continues to shrink, and the aspect ratios of trenches and vias become increasingly larger, the inherent limitations of static water tanks are becoming more apparent. Ultrasonic cleaning solutions have emerged as a solution.

[0003] Utility model patent CN223946369U discloses an ultrasonic cleaning device for semiconductor components, including an ultrasonic cleaner. Mounting bases are fixedly connected to the top of both sides of the ultrasonic cleaner. A support frame is mounted on the top of the mounting bases. A dryer is mounted on the top of the support frame. Air ducts are installed on both sides of the dryer, and exhaust ports are installed at the bottom of the air ducts. Hydraulic cylinders are installed on both sides of the bottom of the support frame, and fixing blocks are fixedly connected to the output ends of the hydraulic cylinders. A placement frame is provided below the support frame. During cleaning, the semiconductor components need to be laid inside the placement frame, and then laid on a first mesh plate and a second mesh plate respectively to achieve a three-layer flat laying.

[0004] Generally, ultrasonic cleaning involves using water flow to remove dirt. However, current water flow solutions only allow water to enter through a pipe at one end and exit at the other, which can easily create dead zones in the water flow, resulting in uneven rinsing force and limited ability to remove dirt. Summary of the Invention

[0005] This application provides an ultrasonic water tank for cleaning semiconductors, which uses uniform upward-flowing water to rinse semiconductor parts, minimizing dead corners and achieving better cleaning results.

[0006] This application provides an ultrasonic water bath for semiconductor cleaning, which adopts the following technical solution: An ultrasonic water tank for semiconductor cleaning includes a tank body. An ultrasonic module is installed on the outer bottom of the tank body. The tank body has a water outlet. Two water inlet pipes are symmetrically connected to the bottom of the side wall of the tank body. The two water inlet pipes are L-shaped inside the tank body and are connected by multiple connecting pipes. The connecting pipes are arranged in parallel and with equal spacing. Multiple water inlet holes are evenly opened on the top surface of the connecting pipes along the length direction. A flow equalizing plate is fixed inside the tank body. The flow equalizing plate is located directly above the connecting pipes, and flow equalizing holes are evenly opened in the middle of the flow equalizing plate.

[0007] By adopting the above technical solution, the water flows upward after passing through the inlet pipe, connecting pipe, and inlet hole. After passing through the flow equalization plate, it forms a uniform upward water flow. The semiconductor parts are rinsed by the uniform upward water flow, which makes it less likely to have dead corners and the cleaning effect is better.

[0008] Optionally, the inner wall of the trough is provided with a stepped groove, and a mesh plate is placed in the stepped groove.

[0009] By adopting the above technical solution, the mesh plate is installed through the stepped groove, which prevents the mesh plate from moving downwards and allows it to be lifted and moved upwards.

[0010] Optionally, an electric cylinder is provided outside the tank body. The electric cylinder is vertically arranged, and a connecting mechanism is fixed to the telescopic end of the electric cylinder. The lower end of the connecting mechanism is located inside the tank body and is connected to a second plate. The second plate has holes evenly opened in the middle, and the size and arrangement shape of the holes are the same as those of the flow equalization holes.

[0011] By adopting the above technical solution, the second plate is raised and lowered by an electric cylinder. When the second plate is positioned above the flow equalization plate and there is a significant gap between them, the uniformity of the rising water flow can be further improved. After the height of the second plate increases, it can lift the mesh plate and the crystals above it off the water surface.

[0012] Optionally, the connecting mechanism includes a top plate and a micro motor fixed to the top plate. The output end of the micro motor is fixed with a rotating shaft, and the lower end of the rotating shaft is eccentrically fixed with an eccentric disk. The eccentric disk is rotatably connected to the second plate.

[0013] By adopting the above technical solution, the micro motor drives the eccentric disk to rotate during operation, thereby causing plate two to make a circular motion on the horizontal plane. During the circular motion, the rotation center of hole two is located at the center of the corresponding uniform flow hole. In this state, the total flow area is greatly reduced, which can increase the upward flow velocity of water and improve the cleaning effect.

[0014] Optionally, after the second plate moves downward, it is in close contact with the top surface of the flow equalization plate, and the second hole is eccentrically arranged with an overlapping area with the flow equalization hole.

[0015] By adopting the above technical solution, when the second plate moves in a circular motion on the horizontal plane, the flow position of the second hole and the uniform flow hole changes periodically, and the total effective area of ​​the upward-flowing water does not decrease, thus achieving the effect of impacting dirt and further improving the uniformity and efficiency of cleaning.

[0016] Optionally, the flow equalizer is made of Teflon.

[0017] By adopting the above technical solution, Teflon has the characteristic of self-lubrication, which reduces the frictional resistance between it and the plate and reduces wear.

[0018] Optionally, electric heating elements are installed on all four outer walls of the tank.

[0019] By adopting the above technical solution, the electric heating element is used to heat the water in the tank, enhance the cavitation intensity, and improve the effect of ultrasonic cleaning.

[0020] Optionally, the water outlet is provided with four outlets and distributed at the four corners of the tank.

[0021] By adopting the above technical solutions, sewage can quickly enter the nearest outlet, improving drainage efficiency and reducing secondary pollution.

[0022] Optionally, the water outlet is connected to a filter and then to a water storage tank, and the bottom of the water storage tank is connected to an inlet pipe via a water pump.

[0023] By adopting the above technical solution, a water circulation is formed, which retains most of the heat in the water, enabling the electric heating element to function.

[0024] Optionally, two spray pipes are fixed to the upper part of the tank. The spray pipes are located close to the inner wall of the tank and have multiple cleaning holes along their length, with the cleaning holes facing the middle of the tank.

[0025] By adopting the above technical solution, the spray pipe is used to assist in rinsing the surface of the semiconductor wafer from above.

[0026] In summary, this application includes at least one of the following beneficial technical effects: 1. Through a uniform upward fluid layout, working in conjunction with ultrasonic vibration, it achieves efficient and thorough cleaning, specifically designed to solve the problem of particle residue at the bottom of wafer trenches; 2. It adopts a dual-mode water flow upward cleaning, and the two modes can be used alternately for better cleaning effect; 3. After cleaning, the wastewater leaves the tank through the outlet. The water flow direction is stable, the cleaning effect is good, and it is not easy to cause secondary pollution. Attached Figure Description

[0027] Figure 1 This is a perspective view of an ultrasonic water tank for semiconductor cleaning according to an embodiment; Figure 2 This is a top view of an embodiment; Figure 3 This is a top view of the water inlet pipe and connecting pipe in the embodiment; Figure 4 This is a front sectional view of an embodiment; Figure 5 This is a perspective view of the connecting mechanism and plate two in the embodiment; Figure 6 This is a diagram showing the fit between the second hole and the flow equalization hole in the embodiment.

[0028] Explanation of reference numerals in the attached drawings: 1. Tank body; 11. Ultrasonic module; 12. Electric heating element; 13. Drain pipe; 2. Water inlet pipe; 21. Connecting pipe; 22. Water inlet hole; 3. Flow equalization plate; 31. Flow equalization hole; 14. Water outlet; 4. Spray pipe; 41. Cleaning hole; 15. Stepped trough; 16. Mesh plate; 5. Electric cylinder; 6. Plate 2; 61. Hole 2; 51. Top plate; 52. Micro motor; 53. Rotating shaft; 54. Eccentric disc. Detailed Implementation

[0029] The present application will be further described in detail below with reference to the accompanying drawings.

[0030] Reference Figure 1 and Figure 2 This embodiment discloses an ultrasonic water tank for semiconductor cleaning, including a tank body 1, which is a rectangular tank made of stainless steel. An ultrasonic module 11 is installed on the outer bottom of the tank body 1 for applying ultrasonic vibrations to the water inside the tank body 1. Electric heating elements 12 are installed on the four outer side walls of the tank body 1 to heat the water inside the tank body 1, enhance cavitation intensity, and improve the ultrasonic cleaning effect. A drain pipe 13 and an electrically controlled valve are provided at the inner bottom of the tank body 1 for draining water from the tank body 1 when the water becomes excessively dirty, and then replacing the water.

[0031] Reference Figure 3 and Figure 4 Two water inlet pipes 2 are symmetrically connected to the bottom sidewall of the tank 1. The two water inlet pipes 2 form an L-shape within the tank 1 and are connected by multiple connecting pipes 21. These connecting pipes 21 are parallel and evenly spaced, and their top surfaces are evenly provided with multiple water inlet holes 22 along their length. A flow equalizer 3 is fixed inside the tank 1, located directly above the connecting pipes 21. The flow equalizer 3 has evenly distributed flow equalizer holes 31 in its center. The dual-head water inlet process and the arrayed distribution of the water inlet holes 22 ensure consistent water flow at the bottom, preventing stagnant water. The flow equalizer 3 further ensures a uniform and stable upward flow of water.

[0032] Reference Figure 2 and Figure 4 The tank 1 is equipped with four outlets 14, distributed at the four corners of the tank 1. Water in the tank 1 is discharged through overflow, preventing overflow and maintaining a consistent water level. This also facilitates rapid wastewater discharge and avoids secondary pollution. The outlets 14 are connected to a filter and then to a water storage tank. The bottom of the water storage tank is connected to the inlet pipe 2 via a water pump, creating a circulation system. The filter removes impurities from the wastewater, and the circulation system retains most of the heat in the water, allowing the electric heating element 12 to function. The water storage tank has a water inlet. Since the water storage tank is only used as an intermediate component, a small-capacity tank is sufficient.

[0033] Two spray pipes 4 are fixed in the upper part of the tank 1. The spray pipes 4 are set close to the inner wall of the tank 1 to avoid the wafer insertion and removal position. The spray pipes 4 have multiple cleaning holes 41 along their length. The cleaning holes 41 face the middle of the tank 1. The spray pipes 4 are used to assist in rinsing the surface of the semiconductor wafer from above.

[0034] The inner wall of the tank 1 is provided with a stepped groove 15, and a mesh plate 16 is placed in the stepped groove 15. The mesh plate 16 is supported by the stepped groove 15 to prevent it from moving downward. The mesh plate 16 is used to place the semiconductor wafers to be cleaned. Generally, a special hollow frame is used to place multiple wafers. The wafers are arranged vertically, and the hollow frame is placed on the mesh plate 16 to complete the placement.

[0035] Reference Figure 4 and Figure 5 An electric cylinder 5 is installed outside the tank body 1. The electric cylinder 5 is vertically arranged, and a connecting mechanism is fixed to the telescopic end of the electric cylinder 5. The lower end of the connecting mechanism is located inside the tank body 1 and connected to a plate 6. The plate 6 has holes 61 evenly spaced in the middle, and the holes 61 have the same size and arrangement as the flow equalization holes 31. The electric cylinder 5 drives the plate 6 to rise and fall. The plate 6 is positioned above the flow equalization plate 3. When there is a significant gap between the two, the uniformity of the water flow can be further improved. After the height of the plate 6 is raised, it can lift the mesh plate 16 and the crystals above it off the water surface, making it convenient for the spray pipe 4 to rinse the crystals and then dry them. After the program is set, it can run automatically.

[0036] The connecting mechanism includes a top plate 51 and a micro motor 52 fixed to the top plate 51. The top plate 51 is fixed to the output end of the electric cylinder 5. A rotating shaft 53 is fixed to the output end of the micro motor 52. An eccentric disk 54 is eccentrically fixed to the lower end of the rotating shaft 53. The eccentric disk 54 is rotatably connected to the second plate 6. A set of electric cylinders 5 and the connecting mechanism are respectively set on the left and right sides of the tank 1. The two electric cylinders 5 operate synchronously, and the two micro motors 52 also operate synchronously to ensure the stability of the lifting and lowering of the second plate 6 and prevent the second plate 6 from tilting.

[0037] Reference Figure 5 and Figure 6 By shortening the electric cylinder 5, plate 6 moves downward and comes into close contact with the top surface of the flow equalization plate 3. Hole 61 and flow equalization hole 31 are eccentrically positioned and have overlapping areas. At this time, the micro motor 52 drives the eccentric disk 54 to rotate, thereby causing plate 6 to make a circular motion on the horizontal plane. During this circular motion, the rotation center of hole 61 is located at the center of the corresponding flow equalization hole 31. The flow equalization plate 3 is made of Teflon, which has self-lubricating properties and reduces friction underwater.

[0038] The implementation principle of an ultrasonic water tank for semiconductor cleaning according to an embodiment of this application is as follows: Preparation stage: Place the wafers that have completed the chemical cleaning process and the preliminary cleaning into a special cutout frame, and then place the cutout frame into the mesh plate 16 in the tank 1.

[0039] Cleaning and Heating: The bottom water inlet system is activated, and water flows upwards through inlet pipe 2, connecting pipe 21, and inlet hole 22, forming a uniform upward flow after passing through the flow equalization plate 3. Simultaneously, the electric heating element 12 can be activated to raise the water temperature to the process requirements (e.g., 20-80°C). The cleaned wastewater exits the tank 1 from outlet 14, ensuring a stable water flow direction, good cleaning effect, and minimizing the risk of secondary pollution. In the final rinse stage, the water temperature is raised to approximately 80°C to accelerate the volatilization of chemical residues.

[0040] The cleaning process includes two modes: Mode 1, where there is a significant gap between plate 6 and the flow equalization plate 3, and hole 61 and flow equalization hole 31 are combined. The double-layer flow equalization further improves the uniformity of the upward water flow, cleaning the wafer. Mode 2, after plate 6 moves downward, it adheres tightly to the top surface of the flow equalization plate 3. Hole 61 and flow equalization hole 31 are eccentrically positioned and have overlapping areas. When the micro motor 52 operates, it drives the eccentric disk 54 to rotate, thereby causing plate 6 to make a small circular motion on the horizontal plane. During this circular motion, the rotation center of hole 61 is located at the center of the corresponding flow equalization hole 31. In this state, the total flow area is significantly reduced, increasing the upward water flow velocity and improving the cleaning effect. Furthermore, the overlapping flow position of hole 61 and flow equalization hole 31 changes periodically, without reducing the total effective area of ​​the upward-flowing water, effectively impacting the contaminants and further improving cleaning uniformity and efficiency. These two modes can be used alternately for better results.

[0041] Ultrasonic cleaning: Activate the ultrasonic module 11 at the bottom to generate high-frequency mechanical vibration in the liquid in the entire tank 1. The "cavitation effect" generated by the ultrasonic waves in the liquid will generate a large number of microbubbles. When these bubbles burst, the microjet generated can penetrate the obstruction of the high aspect ratio structure and directly impact the bottom of the trench, causing the tiny particles adsorbed by the wafer to loosen and fall off.

[0042] Rinsing: After the wafer leaves the water, the top spray pipe 4 sprays cleaning water downwards to completely clean the wafer surface. Combined with the lifting and lowering control of the plate 6 by the electric cylinder 5, the material can be automatically moved away from the water surface and rinsed, as well as subsequently drip-dried.

[0043] In summary, this solution achieves efficient and thorough cleaning by using a uniform upward fluid distribution in conjunction with ultrasonic oscillation, specifically designed to address the problem of particle residue at the bottom of wafer trenches.

[0044] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. An ultrasonic water tank for semiconductor cleaning, comprising a tank body (1), wherein an ultrasonic module (11) is installed on the outer bottom of the tank body (1), and the tank body (1) is provided with a water outlet (14), characterized in that: The bottom of the side wall of the tank (1) is symmetrically connected to two water inlet pipes (2). The two water inlet pipes (2) are L-shaped inside the tank (1). The two water inlet pipes (2) are connected by multiple connecting pipes (21). The connecting pipes (21) are arranged in parallel and at equal intervals. Multiple water inlet holes (22) are evenly opened on the top surface of the connecting pipes (21) along the length direction. A flow equalizing plate (3) is fixed inside the tank (1). The flow equalizing plate (3) is located directly above the connecting pipes (21). Flow equalizing holes (31) are evenly opened in the middle of the flow equalizing plate (3). An electric cylinder (5) is provided outside the tank (1). The electric cylinder (5) is set vertically. A connecting mechanism is fixed to the telescopic end of the electric cylinder (5). The lower end of the connecting mechanism is located inside the tank (1) and connected to a plate (6). Holes (61) are evenly opened in the middle of the plate (6). The size and arrangement shape of the holes (61) are the same as those of the flow equalization holes (31). The connecting mechanism includes a top plate (51) and a micro motor (52) fixed to the top plate (51). The output end of the micro motor (52) is fixed with a rotating shaft (53). The lower end of the rotating shaft (53) is eccentrically fixed with an eccentric disk (54). The eccentric disk (54) is rotatably connected to the second plate (6).

2. The ultrasonic water tank for semiconductor cleaning according to claim 1, characterized in that: The inner wall of the trough (1) is provided with a stepped groove (15), and a mesh plate (16) is placed in the stepped groove (15).

3. The ultrasonic water tank for semiconductor cleaning according to claim 1, characterized in that: After the second plate (6) moves downward, it is in close contact with the top surface of the flow equalization plate (3). The second hole (61) and the flow equalization hole (31) are eccentrically arranged and have overlapping areas.

4. The ultrasonic water tank for semiconductor cleaning according to claim 3, characterized in that: The flow equalization plate (3) is made of Teflon.

5. The ultrasonic water bath for semiconductor cleaning according to claim 1, characterized in that: Electric heating elements (12) are installed on the four outer side walls of the tank (1).

6. The ultrasonic water bath for semiconductor cleaning according to claim 1, characterized in that: The water outlet (14) has four outlets and is distributed at the four corners of the tank (1).

7. The ultrasonic water bath for semiconductor cleaning according to claim 6, characterized in that: The outlet (14) is connected to the water storage tank through the filter, and the bottom of the water storage tank is connected to the inlet pipe (2) through the water pump.

8. The ultrasonic water bath for semiconductor cleaning according to claim 1, characterized in that: Two spray pipes (4) are fixed in the upper part of the tank (1). The spray pipes (4) are located close to the inner wall of the tank (1). The spray pipes (4) have multiple cleaning holes (41) along their length. The cleaning holes (41) face the middle of the tank (1).

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