Wafer cleaning apparatus and cleaning method

Abstract

The present invention discloses a wafer cleaning apparatus and a cleaning method relating to the semiconductor equipment field. The wafer cleaning apparatus comprises a first tank for containing a cleaning solution and a wafer, a second tank for containing the cleaning solution, a spray mechanism for spraying the cleaning solution onto the wafer, and a second circulation filtering pipeline. The liquid inlet of the second circulation filtering pipeline is in communication with the first tank, the second tank is provided in the second circulation filtering pipeline, and the liquid outlet of the second circulation filtering pipeline is in communication with the spray mechanism. The second circulation filtering pipeline can discharge the cleaning solution in the first tank to the second tank and send the liquid from the second tank to the spray mechanism. The cleaning solution in the first tank is discharged to the second tank via the second circulation filtering pipeline, and the wafer can be spray-cleaned via the second circulation filtering pipeline and the spray mechanism, thereby improving the wafer cleaning effect.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor devices, and particularly to a wafer cleaning device and a cleaning method.

Background Art

[0002] In the semiconductor manufacturing process, the cleaning step is an essential step. The batch wet cleaning device has remarkable advantages such as high productivity and low consumption of cleaning liquid, and is currently the mainstream device for cyclic wafer cleaning. One of the significant differences between batch wet cleaning and single-wafer cleaning is the repeated use of the circulating chemical solution. To ensure the relative cleanliness of the chemical solution in the tank, continuous circulation filtering of the chemical solution is required, and contaminants such as particles and metal ions generated after the process need to be discharged outside the tank.

[0003] The circulation of the conventional batch wet cleaning process mainly adopts an internal and external double-tank structure. When the liquid level in the inner tank is filled, it overflows into the outer tank due to gravity, and the cleaning liquid in the outer tank is filtered through the circulation filtering pipeline and finally returns to the inner tank. Through such circulation filtering, most particles and other impurities can be removed. However, only the particles generated in the process of the inner tank that reach the liquid level can overflow into the outer tank, and most of the other particles accumulate downward due to the action of gravity. Therefore, as the number of wafers to be cleaned increases, the impurities in the tank accumulate and the cleaning effect deteriorates.

Summary of the Invention

[0004] An object of the present invention is to provide a wafer cleaning device and a cleaning method to overcome the drawbacks in the conventional batch wet cleaning device, such as a large amount of impurities in the tank and poor cleaning effect.

[0005] To solve the above problems, the present invention provides a first tank for accommodating a cleaning liquid and a wafer, A second tank for storing the cleaning solution, A spray mechanism for spraying cleaning solution onto the wafer, The present invention provides a wafer cleaning apparatus comprising a second circulating filtering pipeline, wherein the liquid inlet of the second circulating filtering pipeline is capable of communicating with the first tank, the second tank is provided in the second circulating filtering pipeline, the liquid outlet of the second circulating filtering pipeline is capable of communicating with the spray mechanism, and the second circulating filtering pipeline is capable of discharging the cleaning liquid in the first tank to the second tank and supplying the liquid from the second tank to the spray mechanism.

[0006] Preferably, the second circulation filtering pipeline further comprises an auxiliary circulation filtering pipeline that communicates with the second tank and circulates and filters the cleaning solution in the second tank.

[0007] Preferably, the second tank comprises a second inner tank and a second outer tank, the auxiliary circulation filtering pipeline connects the second inner tank and the second outer tank, the cleaning liquid in the second inner tank overflows into the second outer tank and returns to the second inner tank via the auxiliary circulation filtering pipeline.

[0008] Preferably, the second circulation filtering pipeline outputs cleaning liquid from the middle or upper region of the second inner tank.

[0009] Preferably, the second tank is further provided with a second drainage line communicating with the second inner tank and a second replenishment line communicating with the second outer tank.

[0010] Preferably, the second circulation filtering pipeline comprises a second circulation filtering branch pipeline located between the first tank and the second tank, and a second circulation filtering branch pipeline located between the second tank and the spray mechanism, and at least one of the pipelines is provided with a circulation pump and a filter.

[0011] Preferably, the second circulation filtering pipeline comprises a second circulation filtering branch pipeline located between the first tank and the second tank, a second circulation filtering branch pipeline located between the second tank and the spray mechanism, and an auxiliary circulation filtering pipeline, with at least one pipeline being provided with a circulation pump and a filter.

[0012] Preferably, the second tank has a single-tank structure, and the auxiliary circulation filtering pipeline shares the circulation pump and the filter with the second circulation filtering pipeline.

[0013] Preferably, the wafer cleaning apparatus further comprises a first circulation filtering pipeline that communicates with the first tank and circulates and filters the cleaning liquid in the first tank.

[0014] Preferably, the first tank comprises a first inner tank and a first outer tank, the first circulation filtering pipeline connects the first inner tank and the first outer tank, the cleaning liquid in the first inner tank overflows into the first outer tank and returns to the first inner tank via the first circulation filtering pipeline.

[0015] Preferably, the first tank is further provided with a first liquid supply line communicating with the first outer tank and a first drain line communicating with the first inner tank.

[0016] Preferably, the wafer cleaning apparatus further includes a liquid level sensor provided in the first tank for detecting the liquid level of the cleaning solution in the first tank.

[0017] The wafer cleaning method, which involves cleaning wafers using the wafer cleaning apparatus described above, is as follows: The steps include: immersing and cleaning the wafer in a first tank, The first step is to completely drain the cleaning solution from the tank, In the process of completely draining the cleaning solution from the first tank, the steps include: discharging at least a portion of the cleaning solution from the first tank to the second tank via the second circulation filtering pipeline; The process includes the step of spray cleaning the wafer via a second circulation filtering pipeline and a spray mechanism.

[0018] Preferably, during the process of immersing and cleaning the wafer, the cleaning solution in the first tank is replaced by draining the cleaning solution from the first tank while replenishing the cleaning solution in the first tank.

[0019] Preferably, the method further includes a step of self-circulating and filtering the cleaning solution in the first tank and / or the cleaning solution in the second tank.

[0020] Preferably, in the step of completely draining the cleaning solution from the first tank, the wafer is immersed and sprayed by a spray mechanism so that the wafer remains moist at all times before it is exposed to the cleaning solution.

[0021] The wafer cleaning method, which involves cleaning wafers using the wafer cleaning apparatus described above, is as follows: The steps include: immersing and cleaning the wafer in a first tank, The first step is to completely drain the cleaning solution from the tank, The procedure includes the steps of completely draining the cleaning solution from the first tank, opening a second circulation filtering pipeline between the first tank and the second tank, supplying the cleaning solution to a spray mechanism through the second circulation filtering pipeline, and spray cleaning the wafer.

[0022] Preferably, the method further includes a step of self-circulating and filtering the cleaning solution in the first tank and / or the cleaning solution in the second tank.

[0023] Preferably, in the step of completely discharging the cleaning liquid in the first tank, before the wafer is exposed from the cleaning liquid, the wafer is immersed and sprayed by a spray mechanism so that the wafer can always maintain a wet state.

[0024] As a remarkable effect achieved by the present invention, in the present invention, by providing the second tank and the second circulation filtering pipeline, the cleaning liquid in the first tank is discharged into the second tank through the second circulation filtering pipeline, and the wafer can be spray-cleaned through the second circulation filtering pipeline and the spray mechanism. Before the cleaning liquid in the first tank is supplied to the spray mechanism, it is filtered again through the second circulation filtering pipeline, and the impurities remaining in the first tank can be removed to improve the cleanliness. By spraying the wafer with the clean cleaning liquid filtered through the second circulation filtering pipeline by the spray mechanism and spray-cleaning the wafer, the cleaning effect of the wafer is improved.

Brief Description of the Drawings

[0025] The features and performance of the present invention are further described by the following embodiments and their drawings. [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a wafer cleaning apparatus according to Embodiment 1 of the present invention. [Figure 2] FIG. 2 is a schematic diagram showing the configuration of a wafer cleaning apparatus according to Embodiment 2 of the present invention. [Figure 3] FIG. 3 is a flowchart of a wafer cleaning method according to Embodiment 3 of the present invention. [Figure 4] FIG. 4 is a flowchart of a wafer cleaning method according to Embodiment 4 of the present invention.

Modes for Carrying Out the Invention

[0026] Hereinafter, the present invention will be further described by embodiments, but the present invention is not limited to the scope of the embodiments thereby.

[0027] Embodiment 1 With the advancement of semiconductor processes, the applications of wafer cleaning equipment are expanding rapidly. Depending on the application and the chemicals used, conventional self-circulating methods using internal / external tanks or single-tank self-circulating systems are no longer sufficient to meet the requirements, particularly in processes such as ashing. As the number of wafers being cleaned increases, impurities such as resist remaining in the tank cannot be properly discharged, negatively impacting the effectiveness of wafer cleaning.

[0028] In contrast, this embodiment provides a wafer cleaning apparatus comprising a first tank 110 and a first circulation filtering pipeline 120, as shown in Figure 1. The first tank 110 contains the cleaning liquid and wafers, and the first circulation filtering pipeline 120 communicates with the first tank 110 and circulates and filters the cleaning liquid in the first tank 110. The wafer cleaning apparatus further comprises a second tank 210, a spray mechanism 300, and a second circulation filtering pipeline 220. The second tank 210 contains the cleaning liquid, and the spray mechanism 300 sprays the cleaning liquid onto the wafers. The liquid inlet of the second circulation filtering pipeline 220 is in communication with the first tank 110, the second tank 210 is provided in the second circulation filtering pipeline 220, the liquid outlet of the second circulation filtering pipeline 220 is in communication with the spray mechanism 300, and the second circulation filtering pipeline 220 can discharge the cleaning liquid in the first tank 110 to the second tank 210 and send the liquid from the second tank 210 to the spray mechanism 300.

[0029] Specifically, in this embodiment, the first tank 110 comprises a first inner tank 111 and a first outer tank 112, and a first circulation filtering pipeline 120 connects the first inner tank 111 and the first outer tank 112. The cleaning liquid in the first inner tank 111 overflows into the first outer tank 112 and returns to the first inner tank 111 via the first circulation filtering pipeline 120. The first circulation filtering pipeline 120 is equipped with a circulation pump 410 and a filter 510, with the liquid inlet of the first circulation filtering pipeline 120 connected to the first outer tank 112 and the liquid outlet connected to the first inner tank 111. Of course, in other embodiments, the first tank 110 may have a single-tank structure.

[0030] The first tank 110 allows for the immersion and dissolution of impurities such as resist on the wafer. When impurities floating in the first inner tank 111 reach the overflow position, they overflow into the first outer tank 112, where they are filtered through the first circulation filtering pipeline 120, removing most of the impurities such as resist before returning to the first inner tank 111. During the wafer cleaning process, the amount of impurities in the first tank 110 increases, and residual resist and other impurities that have not reached the overflow position settle due to gravity, are not filtered, and accumulate at the bottom of the first tank 110, for example, at the bottom of the first inner tank 111, reducing the effectiveness of the wafer immersion cleaning by the first tank 110. By providing a second tank 210 and a second circulation filtering pipeline 220, the cleaning liquid in the first tank 110 is discharged into the second tank 210 via the second circulation filtering pipeline 220, and the wafer can be spray-cleaned via the second circulation filtering pipeline 220 and the spray mechanism 300. The cleaning solution in the first tank 110 is filtered again via the second circulation filtering pipeline 220 before being supplied to the spray mechanism 300, thereby removing impurities, especially those deposited in the first tank 110, and improving the cleanliness of the cleaning solution. Subsequently, the clean cleaning solution filtered via the second circulation filtering pipeline 220 is sprayed onto the wafer via the spray mechanism 300, and the wafer is spray-cleaned, thereby improving the cleaning effect of the wafer.

[0031] In this embodiment, a circulation pump 420 and a filter 520 are provided in the second circulation filtering branch pipeline 220a located between the first tank 110 and the second tank 210. The cleaning liquid in the first tank 110 is filtered by the filter 520 and then discharged into the second tank 210, thereby removing impurities from the cleaning liquid and improving the effectiveness of the wafer spray cleaning.

[0032] Furthermore, a circulation pump 430 and a filter 530 are also provided in the second circulation filtering branch pipeline 220b located between the second tank 210 and the spray mechanism 300. The cleaning liquid in the second tank 210 is filtered through the filter 530 before reaching the spray mechanism 300, where it cleans the wafers. This further improves the cleanliness of the cleaning liquid supplied to the spray mechanism 300 and enhances the effectiveness of the wafer spray cleaning.

[0033] To further improve the cleanliness of the cleaning solution supplied to the spray mechanism 300, the second circulation filtering pipeline 220 is further equipped with an auxiliary circulation filtering pipeline 230. The auxiliary circulation filtering pipeline 230 communicates with the second tank 210 and circulates and filters the cleaning solution in the second tank 210. The auxiliary circulation filtering pipeline 230 can further filter impurities in the cleaning solution in the second tank 210, thereby increasing the cleanliness of the cleaning solution supplied to the spray mechanism 300. A clean cleaning solution can better remove impurities from the wafer surface, ensuring the cleanliness and quality of the wafer.

[0034] In other embodiments, the circulation pump and filter may be provided only in the second circulation filtering branch pipeline 220a located between the first tank 110 and the second tank 210. Alternatively, they may be provided only in the second circulation filtering branch pipeline 220b located between the second tank 210 and the spray mechanism 300. They may also be provided only in the auxiliary circulation filtering pipeline 230. Furthermore, the circulation pump and filter may be provided in any two of the above-mentioned second circulation filtering branch pipelines 220a, 220b and auxiliary circulation filtering pipeline 230. For example, the circulation pump and filter may be provided in both the auxiliary circulation filtering pipeline 230 and the second circulation filtering branch pipeline 220a located between the first tank 110 and the second tank 210.

[0035] In this embodiment, the second tank 210 comprises a second inner tank 211 and a second outer tank 212. An auxiliary circulation filtering pipeline 230 connects the second inner tank 211 and the second outer tank 212. The cleaning liquid in the second inner tank 211 overflows into the second outer tank 212 and returns to the second inner tank 211 via the auxiliary circulation filtering pipeline 230. The cleaning liquid in the second inner tank 211 overflows into the second outer tank 212, removing impurities suspended in the second inner tank 211. The auxiliary circulation filtering pipeline 230 is equipped with a circulation pump 440 and a filter 540. The liquid inlet of the auxiliary circulation filtering pipeline 230 is connected to the second outer tank 212, and the liquid outlet is connected to the second inner tank 211. Of course, in other embodiments, the second tank 210 may have a single-tank structure. A single-tank structure for the second tank 210 reduces the occupied space.

[0036] Furthermore, the second circulation filtering pipeline 220 outputs the cleaning solution from the middle or upper region of the second inner tank 211. Some of the impurities in the second inner tank 211 float upwards and overflow into the second outer tank 212, while other parts settle downwards due to gravity and accumulate at the bottom of the second inner tank 211, resulting in a higher degree of cleanliness of the cleaning solution in the middle or upper region of the second inner tank 211. Therefore, outputting the cleaning solution from the middle or upper region of the second inner tank 211 is advantageous in further improving the wafer cleaning effect.

[0037] To prevent some impurities from being left unfiltered in the second tank 210, the second tank 210 is further provided with a second drainage pipe 250 communicating with the second inner tank 211, and a second replenishment pipe 240 communicating with the second outer tank 212. By providing the second drainage pipe 250 and the second replenishment pipe 240, the cleaning solution in the second tank 210 can be drained while the cleaning solution in the second tank 210 is replenished, completing the replacement of the cleaning solution in the second tank 210 and further improving the cleanliness of the cleaning solution in the second tank 210. Furthermore, the second fluid replenishment line 240 is in communication with the second outer tank 212, allowing for real-time replenishment of the cleaning fluid in the second tank 210. In addition, the new cleaning fluid replenished via the second fluid replenishment line 240 is buffered by the second outer tank 212 and then flows into the second inner tank 211 via the auxiliary circulation filtering line 230, thereby minimizing changes in the concentration and temperature of the cleaning fluid in the second inner tank 211. A valve 650 is provided in the second drainage line 250.

[0038] To reduce impurities in the cleaning solution reaching the second tank 210, the first tank 110 is further provided with a first replenishment line 130 communicating with the first outer tank 112, and a first drain line 140 communicating with the first inner tank 111. By providing the first drain line 140 and the first replenishment line 130, while the wafer is being immersed and cleaned in the first tank 110, the cleaning solution in the first tank 110 can be drained and replenished, allowing for wafer immersion cleaning and replacement of the cleaning solution in the first tank 110, thereby reducing impurities in the cleaning solution reaching the second tank 210. Furthermore, the first fluid replenishment line 130 is in communication with the first outer tank 112, which not only allows for the real-time replenishment of the cleaning fluid in the first tank 110, but also allows the new cleaning fluid replenished via the first fluid replenishment line 130 to flow into the first inner tank 111 via the first auxiliary circulation filtering line 120 after being buffered by the first outer tank 112, thereby making it less likely for changes in the concentration and temperature of the cleaning fluid in the first inner tank 111 to occur.

[0039] The first drainage pipeline 140 shares a single circulation pump 410 with the first circulation filtering pipeline 120, and drainage can be completed by opening valves 610 and 620 and closing valves 630 and 640.

[0040] In this embodiment, all of the above filters are installed on the output end side of the circulation pump, where the pressure is higher and advantageous for improving the filtering effect. Of course, in other embodiments, the filters may be installed on the input end side of the circulation pump to reduce the amount of impurities entering the circulation pump and to improve the service life of the circulation pump.

[0041] In this embodiment, the wafer cleaning apparatus further includes a liquid level sensor (not shown) provided in the first tank 110 for detecting the liquid level of the cleaning solution in the first tank 110. The liquid level sensor allows the liquid level of the cleaning solution in the first tank 110 to be obtained. On the one hand, it becomes easy to replenish the cleaning solution in real time based on the liquid level while the wafer is being immersed and cleaned in the first tank 110. On the other hand, by opening the valve 640 and introducing the cleaning solution from the first tank 110 into the second tank 210 to spray-clean the wafer, it is possible to determine whether the cleaning solution in the first tank 110 has been completely drained.

[0042] Embodiment 2 As shown in Figure 2, the configuration of this embodiment is basically the same as that of Embodiment 1, and the same parts will not be described again here. The difference is that the circulation pump and filter are provided only in the second circulation filtering branch pipeline 220b, which is located between the second tank 210 and the spray mechanism 300. Furthermore, the second tank 210 has a single-tank structure, and the auxiliary circulation filtering pipeline 230 shares the circulation pump 530 and filter 430 with the second circulation filtering branch pipeline 220b, which is advantageous for cost reduction.

[0043] Embodiment 3 This embodiment further provides a wafer cleaning method for cleaning wafers using the wafer cleaning apparatus of Embodiment 1 or Embodiment 2. As shown in Figure 3, the cleaning method is as follows: Step S11 involves immersing and cleaning the wafer in the first tank, Step S12 involves completely draining the cleaning solution from the first tank, In the process of completely draining the cleaning fluid from the first tank, step S13 includes discharging at least a portion of the cleaning fluid from the first tank to the second tank via the second circulation filtering pipeline, Step S14 includes spray cleaning the wafer via a second circulation filtering pipeline and a spray mechanism, During the process of completely draining the cleaning solution from the first tank, the wafer is immersed and sprayed by a spray mechanism to ensure that the wafer remains moist at all times before it is exposed to the cleaning solution.

[0044] In some embodiments, after the cleaning solution in the first tank has been completely drained, the spray mechanism continues spraying onto the wafer for a predetermined time to ensure that impurities and residues on the wafer surface are effectively washed away.

[0045] By circulating and filtering the cleaning solution through the second circulation filtering pipeline, impurities and contaminants are removed from the cleaning solution, maintaining its cleanliness and extending its service life. This not only reduces the cost of the cleaning solution but is also more environmentally friendly. Immersion cleaning of the wafer in the first tank effectively removes most of the dirt and impurities from the wafer surface. Immersion cleaning allows sufficient contact between the cleaning solution and the wafer, thoroughly cleaning any remaining dirt and impurities from the wafer surface and improving the cleaning effect. The cleaning solution is discharged to the second tank through the second circulation filtering pipeline, allowing for further filtering and recycling, which is advantageous for saving the cleaning solution. The spray mechanism sprays the wafer with the filtered cleaning solution, effectively washing away impurities and residues from the wafer surface and further improving the wafer cleaning effect.

[0046] In order to improve the cleanliness of the cleaning solution in the first tank, during the process of performing step S11, the old cleaning solution in the first tank may be drained while new cleaning solution is added to the first tank, thereby replacing the old cleaning solution in the first tank.

[0047] The cleaning method further includes the step of self-circulating filtering the cleaning solution in the second tank. Of course, in some embodiments, the cleaning solution in the first tank may be self-circulating filtered via the first circulation line, or both the cleaning solution in the first tank and the cleaning solution in the second tank may be self-circulating filtered. All of the above self-circulating filtering operations are advantageous in further improving the cleanliness of the cleaning solution.

[0048] Embodiment 4 This embodiment provides a wafer cleaning method different from Embodiment 3, which cleans wafers using the wafer cleaning apparatus of Embodiment 1 or Embodiment 2. As shown in Figure 4, this cleaning method is Step S21 involves immersing and cleaning the wafer in the first tank, Step S22 involves completely draining the cleaning solution from the first tank, Step S23 includes completely draining the cleaning solution from the first tank, opening the second circulation filtering pipeline between the first tank and the second tank, supplying the cleaning solution to the spray mechanism through the second circulation filtering pipeline, and spray cleaning the wafer. During the process of completely draining the cleaning solution from the first tank, the wafer is immersed and sprayed by a spray mechanism before it is exposed to the cleaning solution.

[0049] By circulating and filtering the cleaning solution through the second circulation filtering pipeline, impurities and contaminants are removed from the cleaning solution, maintaining its cleanliness and extending its service life. This not only reduces the cost of the cleaning solution but is also more environmentally friendly. By closing the second circulation filtering pipeline between the first and second tanks before completely draining the cleaning solution from the first tank, the cleaning solution used for immersing wafers in the first tank (which has a relatively high content of impurities and contaminants) is discharged into the second tank, preventing contamination of the cleaning solution used for spraying wafers in the second tank (which is either freshly supplied and clean, or recycled after spraying wafers and has a relatively low content of impurities and contaminants). By immersing and spraying wafers before completely draining the cleaning solution from the first tank, the wafer's wet state can be consistently maintained. By completely draining the cleaning solution from the first tank and then opening the second circulation filtering pipeline between the first and second tanks, the cleaning solution in the first tank after wafer immersion (which has a high impurity content) and the cleaning solution in the second tank for wafer spraying (which is free of impurities or has a low impurity content) do not mix, allowing for a higher level of cleanliness of the cleaning solution during the wafer spraying process. Furthermore, after opening the second circulation filtering pipeline between the first and second tanks, the cleaning solution can be circulated between the first and second tanks, which is advantageous for saving cleaning solution.

[0050] Furthermore, the cleaning method includes a step of self-circulating filtering of the cleaning solution in the second tank. Of course, in some embodiments, the cleaning solution in the first tank may be self-circulating filtered, or both the cleaning solution in the first tank and the cleaning solution in the second tank may be self-circulating filtered. All of the above self-circulating filtering operations are advantageous in further improving the cleanliness of the cleaning solution.

[0051] Although specific embodiments of the present invention have been described above, as those skilled in the art will understand, these are merely illustrative examples, and the scope of protection of the present invention is limited by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and substance of the present invention, and any such changes or modifications will fall within the scope of protection of the present invention.

Claims

1. A first tank for containing the cleaning solution and wafers, A second tank for storing the cleaning solution, A spray mechanism for spraying cleaning solution onto the wafer, A second circulation filtering pipeline is provided, The liquid inlet of the second circulation filtering pipeline is capable of communicating with the first tank, the second tank is provided in the second circulation filtering pipeline, the liquid outlet of the second circulation filtering pipeline is in communication with the spray mechanism, and the second circulation filtering pipeline is capable of discharging the cleaning liquid in the first tank to the second tank and supplying liquid from the second tank to the spray mechanism. A wafer cleaning apparatus characterized by the following features.

2. In the wafer cleaning apparatus according to claim 1, The second circulation filtering pipeline further comprises an auxiliary circulation filtering pipeline that communicates with the second tank and circulates and filters the cleaning liquid in the second tank. A wafer cleaning apparatus characterized by the following features.

3. In the wafer cleaning apparatus according to claim 2, The second tank comprises a second inner tank and a second outer tank, the auxiliary circulation filtering pipeline connects the second inner tank and the second outer tank, the cleaning liquid in the second inner tank overflows into the second outer tank and returns to the second inner tank via the auxiliary circulation filtering pipeline. A wafer cleaning apparatus characterized by the following features.

4. In the wafer cleaning apparatus according to claim 3, The second circulation filtering pipeline outputs cleaning fluid from the middle or upper region of the second inner tank. A wafer cleaning apparatus characterized by the following features.

5. In the wafer cleaning apparatus according to claim 3, The second tank is further provided with a second drainage pipe communicating with the second inner tank and a second replenishment pipe communicating with the second outer tank. A wafer cleaning apparatus characterized by the following features.

6. In the wafer cleaning apparatus according to claim 1, The second circulation filtering pipeline comprises a second circulation filtering branch pipeline located between the first tank and the second tank, and a second circulation filtering branch pipeline located between the second tank and the spray mechanism, and at least one of the pipelines is provided with a circulation pump and a filter. A wafer cleaning apparatus characterized by the following features.

7. In the wafer cleaning apparatus according to claim 2, The second circulation filtering pipeline comprises a second circulation filtering branch pipeline located between the first tank and the second tank, a second circulation filtering branch pipeline located between the second tank and the spray mechanism, and an auxiliary circulation filtering pipeline, and at least one of the pipelines is provided with a circulation pump and a filter. A wafer cleaning apparatus characterized by the following features.

8. In the wafer cleaning apparatus according to claim 7, The second tank has a single-tank structure, and the auxiliary circulation filtering pipeline shares the circulation pump and the filter with the second circulation filtering pipeline. A wafer cleaning apparatus characterized by the following features.

9. In the wafer cleaning apparatus according to claim 1, The wafer cleaning apparatus further comprises a first circulation filtering pipeline that communicates with the first tank and circulates and filters the cleaning liquid in the first tank. A wafer cleaning apparatus characterized by the following features.

10. In the wafer cleaning apparatus according to claim 9, The first tank comprises a first inner tank and a first outer tank, the first circulation filtering pipeline connects the first inner tank and the first outer tank, the cleaning liquid in the first inner tank overflows into the first outer tank and returns to the first inner tank via the first circulation filtering pipeline. A wafer cleaning apparatus characterized by the following features.

11. In the wafer cleaning apparatus according to claim 10, The first tank is further provided with a first liquid supply line communicating with the first outer tank, and a first drain line communicating with the first inner tank. A wafer cleaning apparatus characterized by the following features.

12. In the wafer cleaning apparatus according to claim 1, The wafer cleaning apparatus further includes a liquid level sensor provided in the first tank for detecting the liquid level of the cleaning solution in the first tank. A wafer cleaning apparatus characterized by the following features.

13. A method for cleaning a wafer using a wafer cleaning apparatus according to any one of claims 1 to 12, The steps include: immersing and cleaning the wafer in a first tank, The first step is to completely drain the cleaning solution from the tank, In the process of completely draining the cleaning solution from the first tank, the step of draining at least a portion of the cleaning solution from the first tank to the second tank via the second circulation filtering pipeline, The step includes spray cleaning the wafer via a second circulation filtering pipeline and a spray mechanism, A wafer cleaning method characterized by the following features.

14. In the wafer cleaning method according to claim 13, In the process of immersion cleaning a wafer, the cleaning solution in the first tank is replaced by draining the cleaning solution from the first tank and replenishing the cleaning solution in the first tank. A wafer cleaning method characterized by the following features.

15. In the wafer cleaning method according to claim 13, Furthermore, the process includes a step of self-circulating and filtering the cleaning solution in the first tank and / or the cleaning solution in the second tank. A wafer cleaning method characterized by the following features.

16. In the wafer cleaning method according to claim 13, In the step of completely draining the cleaning solution from the first tank, the wafer is immersed and sprayed by a spray mechanism so that the wafer remains moist at all times before it is exposed from the cleaning solution. A wafer cleaning method characterized by the following features.

17. A method for cleaning a wafer using a wafer cleaning apparatus according to any one of claims 1 to 12, The steps include: immersing and cleaning the wafer in a first tank, The first step is to completely drain the cleaning solution from the tank, The process includes the steps of completely draining the cleaning solution from the first tank, opening the second circulation filtering pipeline between the first tank and the second tank, supplying the cleaning solution to the spray mechanism through the second circulation filtering pipeline, and spray cleaning the wafer. A wafer cleaning method characterized by the following features.

18. In the wafer cleaning method according to claim 17, Furthermore, the process includes a step of self-circulating and filtering the cleaning solution in the first tank and / or the cleaning solution in the second tank. A wafer cleaning method characterized by the following features.

19. In the wafer cleaning method according to claim 17, In the step of completely draining the cleaning solution from the first tank, the wafer is immersed and sprayed by a spray mechanism so that the wafer remains moist at all times before it is exposed from the cleaning solution. A wafer cleaning method characterized by the following features.

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