A cleaning method using wafer cleaning equipment

Abstract

This invention provides a cleaning method using a wafer cleaning equipment. First, the kinetic energy of the jet from the spray assembly impacts the wafer surface, flushing out residual cleaning solutions within the microstructures of the wafer surface. Second, continuous overflow of the cleaning solution and continuous rinsing of the wafer surface and the sides of the electroplating fixture improve the cleanliness of these surfaces. During this stage, a bottom inlet, bottom outlet, and overflow collection tank ensure rapid inflow and outflow of the cleaning solution, quickly bringing the liquid in the process chamber to pH neutral and preventing contamination. Finally, a side inlet assembly rinses the sides of the electroplating fixture, overcoming the shortcomings of traditional cleaning processes that cannot simultaneously clean the sides of the electroplating fixture. Through the combination of these steps, this invention overcomes the defects of existing cleaning processes, such as slow drainage and incomplete cleaning, ensuring wafer surface cleanliness and guaranteeing the performance of semiconductor devices.

Description

Technical Field

[0001] This invention relates to the field of semiconductor processing technology, and more specifically, to a cleaning method using wafer cleaning equipment. Background Technology

[0002] With the continuous increase in IC integration density, ensuring wafer surface cleanliness is crucial for obtaining high-performance and high-yield IC devices. Therefore, industry standards for wafer surface cleanliness are becoming increasingly stringent, making wafer cleaning a critical component of the manufacturing process. Cleaning aims to minimize impurities adhering to the wafer surface to prevent them from adversely affecting IC device performance and thus avoiding product reliability issues. Therefore, in the wafer fabrication process, a thorough cleaning of the wafer is required before proceeding to the next step.

[0003] In current wafer manufacturing processes, wafers are immersed in various reagents under the clamping of electroplating fixtures and then cleaned in cleaning equipment while still being held in the electroplating fixtures. Figure 1 The structure of a prior art electroplating fixture 200 is shown. During the process, the wafer is placed at the bottom of the electroplating fixture 200 (arrow B points to the position). A protective shell is provided at the bottom of the electroplating fixture 200 (arrow A points to the edge of the protective shell). Because there are many and relatively precise and complex internal components of the electroplating fixture 200, care must be taken to prevent water from entering the electroplating fixture 200 during operation, that is, the liquid level of the process liquid must not exceed the edge of the protective shell.

[0004] Therefore, existing cleaning processes cannot directly immerse the electroplating fixture carrying the wafer in the cleaning solution. Instead, the electroplating fixture is often placed horizontally in the process chamber of the cleaning equipment, and cleaning is performed through horizontal contact between the wafer and the cleaning solution or deionized water. Practice has shown that this type of cleaning process has the following two drawbacks:

[0005] Firstly, the drainage speed is slow, resulting in the presence of reagents from the previous process step (such as electroplating solution) remaining in the process chamber, causing contamination. Secondly, the wafer cleaning is incomplete. On the one hand, the horizontal contact between the wafer and the cleaning solution or deionized water cannot remove the dirt from the fine structure of the wafer surface. On the other hand, this cleaning process cannot simultaneously clean the wafer surface and the sides of the electroplating fixture (Note: If the sides of the electroplating fixture are not cleaned, the uncleaned electroplating fixture will contaminate the cleaned wafer because the wafer is held in the electroplating fixture for various processes).

[0006] The two drawbacks mentioned above hinder further improvements in wafer surface cleanliness, thereby adversely affecting the reliability of semiconductor devices. Therefore, there is an urgent need in the field for a cleaning process that can overcome these two shortcomings. Summary of the Invention

[0007] In view of the deficiencies in the prior art, the purpose of this invention is to provide a cleaning method using wafer cleaning equipment. Through the close coordination of each process step, it takes into account both the cleaning of the wafer and the electroplating fixture, greatly improving the surface cleanliness of the wafer and ensuring the reliability of semiconductor devices.

[0008] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0009] A cleaning method using a wafer cleaning equipment, the wafer cleaning equipment including a process chamber, the process chamber including a cleaning tank and a liquid collection overflow tank arranged around the cleaning tank, the liquid collection overflow tank being connected to an overflow drain; the bottom of the cleaning tank is provided with a bottom water inlet, a bottom drain and a spray assembly; the upper part of the inner wall of the process chamber is provided with a side water inlet assembly, the side water inlet assembly including a plurality of side water inlets arranged along the circumferential direction of the inner wall of the process chamber; the cleaning method includes the following steps:

[0010] S10. The electroplating fixture clamps the wafer into the process chamber, the spray assembly and bottom drain are turned on, the spray assembly sprays cleaning liquid onto the bottom of the electroplating fixture, the cleaning waste liquid is discharged through the bottom drain, and after maintaining the first preset time, the spray assembly and bottom drain are turned off.

[0011] S20. Keep the edge of the electroplating fixture protective shell slightly higher than the upper edge of the liquid overflow tank, inject cleaning liquid into the cleaning tank through the bottom water inlet, and let the cleaning liquid overflow through the liquid overflow tank. After maintaining the second preset time, close the bottom water inlet and open the bottom drain outlet to discharge the cleaning waste liquid in the cleaning tank.

[0012] S30. Make the edge of the electroplating fixture protective shell slightly higher than the side inlet of the side water inlet component, turn on the side water inlet component, and spray cleaning liquid onto the side below the edge of the electroplating fixture protective shell. The cleaning waste liquid is discharged through the bottom drain and / or the liquid collection overflow tank. After maintaining the third preset time, turn off the side water inlet component to complete the cleaning.

[0013] In this technical solution, by adopting the structural design described above, on the one hand, the spray assembly utilizes the kinetic energy of the jet to impact the wafer surface, thereby flushing out residual cleaning solutions within the microstructures of the wafer surface. The side-inlet assembly overcomes the limitation of traditional cleaning equipment in not being able to simultaneously clean the sides of the electroplating fixture. On the other hand, the bottom inlet, bottom outlet, and overflow collection tank enable rapid inflow and outflow of the cleaning solution, quickly bringing the fluid within the process chamber to pH neutral, preventing contamination of the process chamber. Furthermore, the combined effect of these two components achieves thorough rinsing of both the wafer surface and the sides of the electroplating fixture. This technical solution overcomes the shortcomings of existing technologies, such as slow drainage and incomplete or inadequate cleaning, significantly improving wafer surface cleanliness and ensuring the reliability of semiconductor devices.

[0014] It should be noted that, firstly, the cleaning liquid can be a specific cleaning solution or deionized water; for ease of description, this application refers to them collectively as cleaning liquid; secondly, because the internal components of the electroplating fixture are numerous and quite precise and complex, care must be taken to prevent water from entering the electroplating fixture during cleaning. Therefore, the height of the cleaning liquid during the process must never exceed the edge of the protective shell of the electroplating fixture (Note: In the wafer manufacturing process, the wafer is immersed in various reagents under the clamping of the electroplating fixture. For the same reason, the process liquid must also not exceed the edge of the protective shell of the electroplating fixture. Therefore, for cleaning the electroplating fixture, it is only necessary to clean the side below the edge of the protective shell).

[0015] Preferably, in step S20, the cleaning liquid discharged through the overflow tank is recovered and filtered, then re-injected into the process chamber through the bottom inlet and circulated in this way. After maintaining this for a second preset time, the bottom inlet is closed and the bottom drain is opened. The cleaning waste liquid in the cleaning tank is discharged through the bottom drain, and the cleaning waste liquid in the overflow tank is discharged through the overflow drain and is not recovered.

[0016] In this technical solution, by adopting the above-described design, the cleaning waste liquid overflowing through the liquid collection overflow tank can be recycled and reused, which greatly reduces the process cost. It also helps to ensure the rapid inflow and outflow of cleaning liquid and the flow balance during the overflow rinsing of the wafer surface and the side of the electroplating fixture.

[0017] Preferably, step S20 specifically includes the following steps:

[0018] S21. Make the edge of the electroplating fixture protective shell slightly higher than the upper edge of the liquid collection overflow tank, open the bottom water inlet to inject cleaning liquid into the cleaning tank, and the cleaning liquid overflows into the liquid collection overflow tank.

[0019] S22. Keep the overflow drain closed until the liquid level in the overflow tank and the liquid level in the cleaning tank reach the preset height difference.

[0020] S23. With the overflow drain in the open position, the cleaning fluid enters the cleaning tank through the bottom inlet and overflows through the collection overflow tank. After maintaining this position for a second preset time, the bottom inlet is closed and the bottom drain is opened, allowing the cleaning waste fluid in the cleaning tank to be discharged through the bottom drain.

[0021] In this technical solution, by adopting the above-described structural design, the valve of the overflow drain outlet is opened with a delay. That is, the overflow drain outlet is opened to discharge the cleaning waste liquid only after the liquid level in the overflow collection tank and the liquid level in the cleaning tank reach a preset height difference. This achieves a balance between the flow rate of water entering the inlet / outlet and the flow rate of water draining from the overflow collection tank.

[0022] Preferably, in step S22, the overflow drain is kept closed until the liquid level in the overflow tank is 8-10 mm lower than the liquid level in the cleaning tank.

[0023] In this technical solution, by adopting the above-described design steps, the overflow drain valve is opened to discharge the cleaning fluid only when the liquid level in the overflow tank is 8-10mm lower than the liquid level outside the overflow tank. This ensures a balance between the flow rate of water entering through the bottom inlet and the flow rate of water draining from the overflow tank.

[0024] Preferably, the bottom of the process chamber is also provided with a hot water nozzle for spraying heated cleaning liquid. In step S10, the electroplating fixture clamps the wafer into the process chamber, and the bottom drain, spray assembly and hot water nozzle are opened. The spray assembly and hot water nozzle spray cleaning liquid onto the bottom of the electroplating fixture. The cleaning waste liquid is discharged through the bottom drain. After maintaining this for a first preset time, the spray assembly, hot water nozzle and bottom drain are closed.

[0025] In this technical solution, by adopting the above design steps, a hot water nozzle is added on the basis of the spray assembly. Through the combined action of the hot water nozzle and the spray assembly, the residual liquid in the microstructure of the wafer surface is washed out, further improving the cleaning effect.

[0026] Preferably, the bottom of the cleaning tank is provided with a dual-purpose inlet / outlet, which is equipped with an inlet valve and a drain valve. When the inlet valve is open and the drain valve is closed, the inlet / outlet functions as a bottom inlet. When the inlet valve is closed and the drain valve is open, the inlet / outlet functions as a bottom drain.

[0027] Since the bottom water inlet and bottom water outlet will not be used simultaneously in the process of this application, this technical solution integrates them into a dual-purpose inlet / outlet, thereby simplifying the structure of the cleaning equipment and improving the ease of operation of the cleaning method.

[0028] Preferably, an annular baffle is provided in the process cavity. The bottom of the annular baffle is fixed to the bottom wall of the process cavity or integrally formed with the bottom wall of the process cavity. A liquid collection overflow groove is formed between the annular baffle and the side wall of the process cavity, and a cleaning groove is formed inside the annular baffle.

[0029] In this technical solution, a cleaning tank and a liquid collection overflow tank surrounding the cleaning tank are formed by designing an annular baffle. Compared with the traditional method of directly opening holes in the side wall of the process chamber to form an overflow tank, this not only simplifies the structure, but also makes it easier to recycle the overflow of cleaning liquid discharged through the liquid collection overflow tank.

[0030] Preferably, the wafer cleaning equipment further includes a storage tank, a recovery pipeline, a circulation control valve, a flow pump, an online heater, and a filter. The overflow drain is connected to the storage tank, and the recovery pipeline is sequentially connected to the drain outlet of the storage tank, the circulation control valve, the flow pump, the online heater, the filter, and the bottom inlet.

[0031] In this technical solution, by adopting the above-described structural design, it is convenient to recycle the cleaning fluid overflowing through the collection overflow tank, which not only reduces the process cost but also simplifies the process flow. Furthermore, during the recycling of the cleaning fluid, an online heater can be used to heat the cleaning fluid to further improve the cleaning effect.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The cleaning method using a wafer cleaning device provided by this invention firstly uses the kinetic energy of the jet from the spray assembly to impact the wafer surface, thereby flushing out residual cleaning solutions within the microstructures of the wafer surface. Secondly, the continuous overflow of cleaning solution continuously rinses the wafer surface and the sides of the electroplating fixture, improving the cleanliness of the wafer surface. During this stage, the inlet, outlet, and overflow collection tank ensure rapid inflow and outflow of the cleaning solution, quickly bringing the liquid in the process chamber to pH neutral and preventing contamination. Finally, the side inlet assembly rinses the sides of the electroplating fixture, overcoming the shortcomings of traditional cleaning processes that cannot simultaneously clean the sides of the electroplating fixture. Through the combination of these steps, this application overcomes the defects of existing cleaning processes, such as slow drainage speed and incomplete or inadequate wafer cleaning, ensuring wafer surface cleanliness and guaranteeing the performance of semiconductor devices. Attached Figure Description

[0034] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0035] Figure 1 This is a schematic diagram of the structure of an electroplating fixture used in the prior art.

[0036] Figure 2 This is a schematic diagram of the structure of the wafer cleaning equipment in an embodiment of the present invention;

[0037] Figure 3 This is a cross-sectional view of the wafer cleaning equipment in an embodiment of the present invention. Figure 1 ;

[0038] Figure 4 This is a cross-sectional view of the wafer cleaning equipment in an embodiment of the present invention. Figure 2 .

[0039] The diagram shows:

[0040] 100-Wafer Cleaning Equipment;

[0041] 10 - Process cavity;

[0042] 11- Bottom wall of the process cavity;

[0043] 12 - Side wall of the process cavity;

[0044] 13-Cleaning space;

[0045] 20 - Inlet / Drainage Port;

[0046] 30 - Spray assembly;

[0047] 31 - Spray inlet;

[0048] 32-Spray pipe;

[0049] 40-Side water inlet assembly;

[0050] 41-Side inlet;

[0051] 51 - Overflow drain outlet;

[0052] 52 - Liquid collection overflow tank;

[0053] 60-Hot water shower head;

[0054] 70- Annular baffle;

[0055] 71-Cleaning tank;

[0056] 200-Electroplation fixture;

[0057] A - Edge of the protective shell;

[0058] B-Wafer Mounting Location Detailed Implementation

[0059] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0060] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.

[0061] It should be noted that similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, all directional indications (such as up, down, left, right, front, back, bottom, etc.) in this application are only used to explain the relative positional relationships and movements between components in a specific orientation (as shown in the figures). If the specific orientation changes, the directional indication will also change accordingly. Furthermore, descriptions involving "first," "second," etc., in this application are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated.

[0062] This invention provides a cleaning method using a wafer cleaning equipment, wherein the wafer cleaning equipment 100 has the following structure: Figures 2-4 As shown, it includes a process cavity 10, which is a near-cylindrical structure with an upward opening, formed by a bottom wall 11 and a side wall 12 of the process cavity. The process cavity 10 has a cleaning space 13 that accommodates the electroplating fixture 200.

[0063] like Figure 2 and Figure 3 As shown, an annular baffle 70 is provided inside the process cavity 10. The bottom of the annular baffle 70 is fixed to or integrally formed with the bottom wall 11 of the process cavity. A liquid collection overflow groove 52 is formed between the annular baffle 70 and the side wall 12 of the process cavity, and a cleaning groove 71 is formed inside the annular baffle 70. The liquid collection overflow groove 52 is connected to an overflow drain 51 located at the bottom of the process cavity 10. In this embodiment, there are four overflow drains 51, which are evenly distributed on the bottom circumference of the process cavity 10.

[0064] Furthermore, such as Figure 3 As shown, the bottom of the cleaning tank 71 is provided with an inlet / outlet 20, which is located at the center of the bottom of the cleaning tank 71. It is a large-diameter dual-purpose port equipped with an inlet valve and a outlet valve. When the inlet valve is open and the outlet valve is closed, the inlet / outlet 20 functions as a bottom inlet; when the inlet valve is closed and the outlet valve is open, it functions as a bottom outlet. During the operation of the wafer cleaning equipment 100, cleaning fluid can quickly enter the cleaning tank 71 through the inlet / outlet 20, or cleaning wastewater can quickly exit the cleaning tank 71 through the inlet / outlet 20.

[0065] Specifically, in this embodiment, the bottom of the cleaning tank 71 adopts an inverted conical structure design, and the inlet / outlet 20 is located at the lowest point of this inverted conical structure. This structural design, on the one hand, allows the inlet / outlet 20 to play a certain buffering role during the injection of a large flow of cleaning fluid, and on the other hand, facilitates the rapid discharge of cleaning waste fluid. At the same time, this structural design also ensures that the spray pipe 32 mentioned later is arranged along the diameter direction of the bottom of the cleaning tank 71 and that the inlet / outlet 20 is located at the center of the bottom of the cleaning tank 71.

[0066] In addition, the wafer cleaning equipment 100 also includes a storage tank, a recovery pipeline, a circulation control valve, a flow pump, an online heater, and a filter. The overflow drain 51 is connected to the storage tank, and the recovery pipeline is sequentially connected to the storage tank's drain port, the circulation control valve, the flow pump, the online heater, the filter, and the inlet / outlet 20. This structural design allows the cleaning fluid overflowing from the collection overflow tank 52 to be recycled. The circulation control valve is opened, and the cleaning fluid flows out through the overflow drain 51 into the storage tank. Under the action of the flow pump, it travels along the recovery pipeline, is heated by the online heater, filtered by the filter, and then reinjected into the cleaning tank 71 through the inlet / outlet 20, thus achieving inlet, overflow, and drainage recycling.

[0067] Furthermore, a spray assembly 30 is also provided inside the cleaning tank 71. The spray assembly 30 includes a spray pipe 32 and a spray inlet 31 located at the bottom of the cleaning tank 71. In this embodiment, as shown... Figure 4 As shown, there are two spray inlets 31, which are connected to the two ends of the spray pipe 32. The spray pipe 32 has multiple spray nozzles along its length. When cleaning the wafer, the cleaning solution enters the spray pipe 32 through the spray inlets 31 and is sprayed onto the bottom of the electroplating fixture 200 through the spray nozzles on the spray pipe 32, i.e., onto the wafer. The kinetic energy of the jet impacts the wafer surface, washing away the residual cleaning solution in the microstructure of the wafer surface.

[0068] Specifically, in this embodiment, the spray pipe 32 is arranged along the diameter direction of the bottom of the cleaning tank 71, thereby enabling spraying directly onto the center of the wafer, improving spray uniformity and cleaning effect. Furthermore, this embodiment also includes a hot water nozzle 60 at the bottom of the cleaning tank 71. The hot water nozzle 60 sprays heated cleaning fluid, which works in conjunction with the spray assembly 30 to enhance the cleaning effect on the wafer surface.

[0069] Furthermore, the process chamber sidewall 12 (specifically the inner sidewall) is also provided with a side water inlet assembly 40. The side water inlet assembly 40 is set above the upper edge of the liquid collection overflow tank 52. The side water inlet assembly 40 includes multiple side water inlets 41. The side water inlets 41 are evenly and equally arranged along the circumference of the process chamber sidewall 12. When cleaning the electroplating fixture 200, the side water inlets 41 surround the side of the electroplating fixture 200 and spray cleaning liquid horizontally onto the side of the electroplating fixture 200 to complete the cleaning of the side of the electroplating fixture 200. Since multiple side water inlets 41 are provided and evenly distributed, the cleaning effect of each position on the side of the electroplating fixture 200 can be guaranteed.

[0070] The cleaning method described in this embodiment is implemented using the wafer cleaning equipment 100 described above, and specifically includes the following steps:

[0071] S10. The electroplating fixture 200 clamps the wafer and enters the process chamber 10. The spray assembly 30 is turned on to spray cleaning fluid onto the bottom of the electroplating fixture 200. The high-intensity spray force washes out the dirt in some fine structures of the wafer. During this step, the drain valve of the inlet / outlet 20 is in the open state and the water inlet valve is in the closed state. The cleaning waste liquid is discharged through the inlet / outlet 20. After maintaining this for a first preset time, the spray assembly 30 and the drain valve of the inlet / outlet 20 are turned off.

[0072] S20. Keep the edge A of the protective shell of the electroplating fixture 200 slightly higher than the upper edge of the overflow tank 52, so that the drain valve of the inlet / outlet 20 is closed and the inlet valve is open. Thus, a large flow of cleaning fluid is injected into the cleaning tank 71 through the inlet / outlet 20. The liquid level rises continuously until it overflows into the overflow tank 52. At this time, the valve of the overflow outlet 51 can be delayed in opening, so that the liquid level of the overflow in the overflow tank 52 continues to rise until the liquid level in the overflow tank 52 and the liquid level in the cleaning tank 71 reach a preset height difference (e.g., 8-10mm lower). At this time, the valve of the overflow outlet 51 is opened, and the cleaning fluid is discharged through the overflow tank 50, so as to achieve a balance between the flow of water injected through the inlet / outlet 20 and the flow of water discharged through the overflow tank 52.

[0073] In step S20, the cleaning solution is continuously injected into the cleaning tank 71 through the inlet / outlet 20 and continuously overflows through the overflow collection tank 52. Since the edge A of the protective shell of the electroplating fixture 200 is only slightly higher than the upper edge of the overflow collection tank 52, the cleaning solution continuously rinses the wafer surface and the area below the edge A of the protective shell of the electroplating fixture 200, thereby improving the cleanliness of the wafer surface and the side of the electroplating fixture 200. Furthermore, the cleaning solution in this stage can be recycled. Specifically, the circulation control valve can be opened simultaneously with the overflow drain 51. After the cleaning solution flows out of the overflow drain 51 into the storage tank, it is heated by the online heater and filtered by the filter along the recovery pipeline under the action of the flow pump, and then reinjected into the cleaning tank 71 through the inlet / outlet 20, realizing the recycling of the cleaning solution. After a period of inlet, overflow, and drainage recycling, the cleaning solution in the process chamber 10 quickly reaches pH neutral. After this stage of cleaning is completed, the inlet valve of the inlet / outlet 20 is closed, the outlet valve is open, and the circulation control valve is closed, so that the liquid in the cleaning tank 71 is quickly discharged through the inlet / outlet 20, and the liquid in the overflow collection trough 52 is quickly discharged through the overflow outlet 51.

[0074] S30. This step will clean the sides of the electroplating fixture 200. Specifically, given that the electroplating fixture 200 has many internal components that are quite precise and complex, care must be taken throughout the entire process to prevent water from entering the electroplating fixture 200. That is, in the last step, the electroplating fixture 200 cannot simply be cleaned by immersing it in the chemical solution. Therefore, in this cleaning step, the electroplating fixture 200 is raised until its protective shell edge A is slightly higher than the side water inlet 41 of the side water inlet assembly 40. Then, water is introduced into the side water inlet 41 to spray and rinse the side of the electroplating fixture 200 and complete the final cleaning. If the cleaning waste liquid in this stage only flows into the cleaning tank 71, the cleaning waste liquid is discharged by opening the drain valve of the inlet / outlet 20. If the cleaning waste liquid in this stage only flows into the overflow collection tank 52, the cleaning waste liquid is discharged by opening the overflow drain 51 and is not recycled. If the cleaning waste liquid in this stage flows into both the cleaning tank 71 and the overflow collection tank 52, the drain valve of the inlet / outlet 20 and the overflow drain 51 are both in the open state, thereby discharging the cleaning waste liquid in a timely manner.

[0075] The cleaning method using a wafer cleaning equipment provided in this embodiment firstly uses the kinetic energy of the jet from the spray assembly 30 to impact the wafer surface, thereby flushing out residual cleaning solutions within the microstructure of the wafer surface. Secondly, the continuous overflow of cleaning solution continuously rinses the wafer surface and the sides below the edge A of the protective shell of the electroplating fixture 200, improving the cleanliness of the wafer surface and the sides of the electroplating fixture. During this stage, the inlet / outlet 20 and the overflow collection tank 52 enable rapid inflow and outflow of the cleaning solution, quickly bringing the liquid in the process chamber 10 to pH neutral and preventing contamination of the process chamber 10. Finally, the side inlet assembly 40 rinses the sides of the electroplating fixture 200, overcoming the shortcomings of traditional cleaning processes that cannot simultaneously clean the sides of the electroplating fixture 200. Through the combination of the above steps, this embodiment overcomes the defects of existing cleaning processes, such as slow drainage speed and incomplete or inadequate wafer cleaning, ensuring wafer surface cleanliness and guaranteeing the performance of semiconductor devices.

[0076] The specific embodiments of the present invention have been described above. Based on the above description, those skilled in the art can make various changes and modifications without departing from the technical concept of the present invention.

Claims

1. A cleaning method using wafer cleaning equipment, characterized in that, The wafer cleaning equipment includes a process chamber, which includes a cleaning tank and a liquid collection overflow tank surrounding the cleaning tank. The liquid collection overflow tank is connected to an overflow drain. The bottom of the cleaning tank is provided with a bottom water inlet, a bottom drain, and a spray assembly. The upper part of the inner wall of the process chamber is provided with a side water inlet assembly, which includes a plurality of side water inlets arranged circumferentially along the inner wall of the process chamber. The cleaning method includes the following steps: S10. The electroplating fixture clamps the wafer into the process chamber, the spray assembly and bottom drain are turned on, the spray assembly sprays cleaning liquid onto the bottom of the electroplating fixture, the cleaning waste liquid is discharged through the bottom drain, and after maintaining the first preset time, the spray assembly and bottom drain are turned off. S20. Keep the edge of the electroplating fixture protective shell slightly higher than the upper edge of the liquid overflow tank, inject cleaning liquid into the cleaning tank through the bottom water inlet, and let the cleaning liquid overflow through the liquid overflow tank. After maintaining the second preset time, close the bottom water inlet and open the bottom drain outlet to discharge the cleaning waste liquid in the cleaning tank. S30. Make the edge of the electroplating fixture protective shell slightly higher than the side inlet of the side water inlet component, turn on the side water inlet component, and spray cleaning liquid onto the side below the edge of the electroplating fixture protective shell. The cleaning waste liquid is discharged through the bottom drain and / or the liquid collection overflow tank. After maintaining the third preset time, turn off the side water inlet component to complete the cleaning.

2. The cleaning method using a wafer cleaning equipment according to claim 1, characterized in that, In step S20, the cleaning liquid discharged through the overflow tank is recovered and filtered, then re-injected into the process chamber through the bottom inlet and circulated in this way. After maintaining this for a second preset time, the bottom inlet is closed and the bottom drain is opened. The cleaning waste liquid in the cleaning tank is discharged through the bottom drain, and the cleaning waste liquid in the overflow tank is discharged through the overflow drain and is not recovered.

3. The cleaning method using wafer cleaning equipment according to claim 1, characterized in that, Step S20 specifically includes the following steps: S21. Make the edge of the electroplating fixture protective shell slightly higher than the upper edge of the liquid collection overflow tank, open the bottom water inlet to inject cleaning liquid into the cleaning tank, and the cleaning liquid overflows into the liquid collection overflow tank. S22. Keep the overflow drain closed until the liquid level in the overflow tank and the liquid level in the cleaning tank reach the preset height difference. S23. With the overflow drain in the open position, the cleaning fluid enters the cleaning tank through the bottom inlet and overflows through the collection overflow tank. After maintaining this position for a second preset time, the bottom inlet is closed and the bottom drain is opened, allowing the cleaning waste fluid in the cleaning tank to be discharged through the bottom drain.

4. The cleaning method using a wafer cleaning equipment according to claim 3, characterized in that, In step S22, the overflow drain is closed until the liquid level in the overflow tank is 8-10 mm lower than the liquid level in the cleaning tank.

5. The cleaning method using a wafer cleaning equipment according to claim 1, characterized in that, The bottom of the process chamber is also equipped with a hot water nozzle for spraying heated cleaning liquid. In step S10, the electroplating fixture clamps the wafer into the process chamber, and the bottom drain, spray assembly and hot water nozzle are turned on. The spray assembly and hot water nozzle spray cleaning liquid onto the bottom of the electroplating fixture. The cleaning waste liquid is discharged through the bottom drain. After maintaining the bottom drain for a first preset time, the spray assembly, hot water nozzle and bottom drain are turned off.

6. The cleaning method using a wafer cleaning equipment according to claim 1, characterized in that, The bottom of the cleaning tank is provided with a dual-purpose inlet / outlet, which is equipped with an inlet valve and a drain valve. When the inlet valve is open and the drain valve is closed, the inlet / outlet functions as a bottom inlet. When the inlet valve is closed and the drain valve is open, the inlet / outlet functions as a bottom drain.

7. The cleaning method using a wafer cleaning equipment according to claim 1, characterized in that, An annular baffle is provided inside the process cavity. The bottom of the annular baffle is fixed to the bottom wall of the process cavity or integrally formed with the bottom wall of the process cavity. A liquid collection overflow groove is formed between the annular baffle and the side wall of the process cavity, and a cleaning groove is formed inside the annular baffle.

8. The cleaning method using a wafer cleaning equipment according to claim 1, characterized in that, The wafer cleaning equipment also includes a storage tank, a recovery pipeline, a circulation control valve, a flow pump, an online heater, and a filter. The overflow drain is connected to the storage tank, and the recovery pipeline is sequentially connected to the drain outlet of the storage tank, the circulation control valve, the flow pump, the online heater, the filter, and the bottom inlet.

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