Wafer cleaning device

Abstract

The invention relates to a wafer cleaning device. The wafer cleaning device comprises a first cleaning tank, a second cleaning tank, a storage tank, a first heater and a controller, an SPM solution discharged by the second cleaning tank is stored through the storage tank, and the SPM solution is replaced by the first cleaning tank under the condition that the SPM solution is replaced by the second cleaning tank. According to the SPM cleaning equipment, the storage tank is controlled by the controller to convey the SPM solution heated to the preset temperature interval through the first heater into the first cleaning tank, so that the problem that the SPM solution cannot be further saved by tank-type or tank-type and single-chip SPM cleaning equipment is solved, the SPM solution is reused, and the SPM solution is further saved.

Description

Technical Field

[0001] The present application relates to the field of wafer cleaning, and in particular to a wafer cleaning device. Background Art

[0002] Existing wafer cleaning equipment includes single-wafer SPM (a mixed solution of sulfuric acid and hydrogen peroxide) cleaning equipment and tank-type SPM cleaning equipment. Since the single-wafer SPM cleaning equipment cannot meet most processes after sulfuric acid and hydrogen peroxide are mixed and diluted and recycled, the amount of sulfuric acid consumed is much greater than that of the tank-type equipment. The single-wafer SPM cleaning equipment consumes a lot of SPM, while the tank-type SPM cleaning equipment consumes less SPM. In terms of particle removal, the tank-type SPM cleaning equipment is inferior to the single-wafer SPM cleaning equipment, and more small particles are added. Generally speaking, the tank-type SPM cleaning equipment is suitable for the removal of particles larger than 60nm, and the single-wafer SPM cleaning equipment is suitable for the removal of particles below 40nm.

[0003] The cleaning equipment that combines tank type and single-wafer cleaning can save more SPM solution than single-wafer SPM cleaning equipment while ensuring the ability to remove particles below 40nm. However, as the process requirements advance to remove particles below 26nm, the current tank type or tank type and single-wafer SPM cleaning equipment can no longer save SPM solution further. Summary of the invention

[0004] An embodiment of the present application provides a wafer cleaning device that can further save sulfuric acid.

[0005] A wafer cleaning device according to an embodiment of the present application includes:

[0006] A first cleaning tank, used for storing the SPM solution and for performing a first cleaning on the wafer;

[0007] A second cleaning tank, used for storing the SPM solution and for performing a second cleaning on the wafer;

[0008] a storage tank, used for storing the SPM solution discharged from the second cleaning tank after the second cleaning tank cleans the wafer for the second time;

[0009] A first heater, used to heat the SPM solution in the storage tank to a preset temperature range;

[0010] The controller is used for controlling the storage tank to transport the SPM solution heated by the first heater to the preset temperature range to the first cleaning tank when the SPM solution is replaced in the first cleaning tank.

[0011] In some of the embodiments, the wafer cleaning device also includes a concentration detector for detecting the concentration of the SPM solution in the storage tank and sending it to the controller when the SPM solution is replaced in the first cleaning tank; the controller is used to compare the concentration of the SPM solution in the storage tank with a preset concentration, and when the concentration of the SPM solution in the storage tank is not less than the preset concentration, control the storage tank to transport the SPM solution heated to the preset temperature range by the first heater to the first cleaning tank.

[0012] In some embodiments, when the controller detects that the concentration of the SPM solution in the storage tank is less than the preset concentration, the controller controls the storage tank to discharge the SPM solution in the storage tank.

[0013] In some embodiments, the wafer cleaning device also includes a first connecting pipe, the first cleaning tank includes a first inner tank and a first outer tank, the first inner tank is used to store SPM solution, and the first outer tank is used to store SPM solution overflowing from the first inner tank; wherein the first connecting pipe connects the first inner tank and the first outer tank.

[0014] In some embodiments, a first buffer tank and a second heater are provided on the first connecting pipeline, the first buffer tank is connected to the first outer tank, the first buffer tank is also connected to the first inner tank, and the second heater is provided on the first connecting pipeline between the first buffer tank and the first inner tank.

[0015] In some embodiments, a first filter is further provided on the first connecting pipeline, and the first filter is provided between the first buffer tank and the second heater.

[0016] In some embodiments, the wafer cleaning device also includes a second connecting pipe, the second cleaning tank includes a second inner tank and a second outer tank, the second inner tank is used to store SPM solution, and the second outer tank is used to store SPM solution overflowing from the second inner tank; wherein the second connecting pipe connects the second inner tank and the second outer tank.

[0017] In some embodiments, a second buffer tank and a third heater are provided on the second connecting pipeline, the second buffer tank is connected to the second outer tank, the second buffer tank is also connected to the second inner tank, and the third heater is provided on the second connecting pipeline between the second buffer tank and the second inner tank.

[0018] In some embodiments, a second filter is further provided on the second connecting pipeline, and the second filter is provided between the second buffer tank and the third heater.

[0019] In some of the embodiments, the system further comprises at least one filter disposed between the first heater and the storage tank.

[0020] To summarize, the wafer cleaning device provided in the embodiment of the present application adopts a storage tank to store the SPM solution discharged from the second cleaning tank, and when the SPM solution is replaced in the first cleaning tank, the controller controls the storage tank to transport the SPM solution heated to a preset temperature range by the first heater to the first cleaning tank. This solves the problem that the tank-type or tank-type and single-wafer SPM cleaning equipment can no longer save SPM solution, realizes the reuse of the SPM solution, and further saves SPM solution.

[0021] Details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0023] Figure 1 is a structural block diagram of a wafer cleaning device according to an embodiment of the present application;

[0024] Figure 2 It is a structural schematic diagram of a wafer cleaning device according to an embodiment of the present application. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments provided in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0026] Unless otherwise defined, the technical terms or scientific terms involved in this application should be understood by people with ordinary skills in the technical field to which this application belongs. The words "one", "a", "a", "the" and the like involved in this application do not indicate a quantitative limitation, and may represent the singular or plural. The terms "include", "comprise", "have" and any of their variations involved in this application are intended to cover non-exclusive inclusions; for example, a process, method, system, product or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units that are not listed, or may also include other steps or units inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "multiple" involved in this application refers to greater than or equal to two. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships, for example, "A and / or B" can represent: A exists alone, A and B exist at the same time, and B exists alone. The terms "first", "second", "third" and the like involved in the present application are merely used to distinguish similar objects and do not represent a specific ordering of the objects.

[0027] An embodiment of the present application provides a wafer cleaning device. Figure 1 is a structural block diagram of a wafer cleaning device according to an embodiment of the present application. Figure 1 As shown, the wafer cleaning device includes a first cleaning tank 10, a second cleaning tank 20, a storage tank 30, a first heater 40 and a controller 50. The first cleaning tank 10 is used to store the SPM solution and is used to perform the first cleaning of the wafer. The second cleaning tank 20 is used to store the SPM solution and is used to perform the second cleaning of the wafer. The storage tank 30 is used to store the SPM solution discharged from the second cleaning tank 20. The first heater 40 is used to heat the SPM solution in the storage tank 30 to a preset temperature range. When the first cleaning tank 10 is replacing the SPM solution, the controller 50 controls the storage tank 30 to transport the SPM solution heated to the preset temperature range by the first heater 40 to the first cleaning tank 10.

[0028] It should be noted that the cleaning equipment is usually equipped with two SPM tanks, wherein the first cleaning tank is used for the first cleaning of the wafer, so its SPM solution concentration is relatively low, and the second cleaning tank is used for the second cleaning of the wafer, and the cleanliness of the wafer is higher than that of the first cleaning, so its consumption of SPM solution is less than that of the first cleaning, and its SPM solution concentration is relatively high. In the prior art, when one of the cleaning tanks reaches the SPM solution replacement cycle or the number of processed wafers reaches a preset number, the SPM solutions in the two cleaning tanks are all discharged, and new SPM solutions are replenished from the factory. The present application provides a wafer cleaning device that discharges the SPM with a higher concentration in the second cleaning tank 20 into the storage tank 30, and the first cleaning tank 10 can supply the SPM in the storage tank 30 to the first cleaning tank 10 when performing the SPM solution replacement, thereby reducing the amount of SPM solution replenished from the factory, realizing the secondary utilization of the SPM solution with a higher concentration, and extending the use cycle, saving the amount of SPM solution used.

[0029] Specifically, the SPM solution includes sulfuric acid and hydrogen peroxide. The saving of SPM solution usage described in the embodiment of the present application can be understood as saving the usage of sulfuric acid in the SPM solution, as shown in Table 1 below, wherein the unit of sulfuric acid (H2SO4) in Table 1 is L, and the quantity in the table represents the number of wafers to be cleaned.

[0030] Table 1 Sulfuric acid usage table

[0031]

[0032] It can be seen from Table 1 that the wafer cleaning device provided in the present application can further save sulfuric acid in the SPM solution on the basis of the existing tank / tank and single-wafer cleaning equipment.

[0033] In some of the embodiments, at least one filter may be disposed between the first heater 40 and the storage tank 30 to filter particles carried by the SPM solution discharged from the second cleaning tank 20 .

[0034] In some embodiments, the SPM solution of the first cleaning tank 10 and the second cleaning tank 20 can be replaced synchronously, that is, when replacing the SPM solution, the solution is discharged synchronously first, the SPM solution in the first cleaning tank 10 is directly discharged, and the SPM solution in the second cleaning tank 20 is discharged into the storage tank 30, and when adding new SPM solution, the solution in the storage tank 30 is added to the first cleaning tank 10, and the new SPM solution is added to the second cleaning tank 20. The synchronous replacement of the SPM solution improves the efficiency of replacing the SPM solution in the first cleaning tank 10 and the second cleaning tank 20.

[0035] In some embodiments, the wafer cleaning device further includes a concentration detector. When the first cleaning tank 10 is replacing the SPM solution, the concentration detector detects the concentration of the SPM solution in the storage tank 30 and sends it to the controller 50. The controller 50 compares the concentration of the SPM solution in the storage tank 30 with a preset concentration, and when the concentration of the SPM solution in the storage tank 30 is not less than the preset concentration, controls the storage tank 30 to transfer the SPM solution heated to a preset temperature range by the first heater 40 to the first cleaning tank 10. The concentration detector is used to detect the concentration of the SPM solution in the storage tank 30 to avoid the concentration of the SPM solution in the storage tank 30 being too low, thereby affecting the cleaning effect of the first cleaning tank 10. The preset concentration can be determined by the process requirements.

[0036] It should be noted that the concentration detector may detect the concentration of the SPM solution by detecting the concentration of sulfuric acid in the SPM solution to reflect the SPM solution.

[0037] In some embodiments, when the controller 50 detects that the concentration of the SPM solution in the storage tank 30 is less than a preset concentration, the controller 50 controls the storage tank 30 to discharge the SPM solution.

[0038] See also Figure 2 In some embodiments, the wafer cleaning device further includes a first connecting pipe. The first cleaning tank 10 includes a first inner tank 11 and a first outer tank 12, the first inner tank 11 is used to store the SPM solution, and the first outer tank 12 is used to store the SPM solution overflowing from the first inner tank 11. The first connecting pipe is used to connect the first inner tank 11 and the first outer tank 12. In this embodiment, the first inner tank 11 and the first outer tank 12 are connected by the first connecting pipe, so that the fluidity of the liquid in the first cleaning tank 10 can be achieved, and the concentration of the solution at each position in the first cleaning tank 10 is ensured to be uniform, thereby achieving a better cleaning effect.

[0039] Continue to see Figure 2, a first buffer tank 13 and a second heater 14 are arranged on the first communicating pipeline, the first buffer tank 13 is communicated with the first outer tank 12, the first buffer tank 13 is also communicated with the first inner tank 11, and the second heater 14 is arranged on the first communicating pipeline between the first buffer tank 13 and the first inner tank 11. In this embodiment, by arranging the first buffer tank 13 on the first communicating pipeline, the SPM solution in the first outer tank 12 can be buffered, and by arranging the second heater 14 on the first communicating pipeline, the circulating SPM solution can be heated, thereby improving the cleaning effect of the SPM solution. At the same time, the first buffer tank 13 can also facilitate the second heater 14 to heat the circulating SPM solution, thereby avoiding the SPM solution from flowing too fast in the first communicating pipeline, so that the SPM solution cannot be heated to the preset temperature range, thereby reducing the cleaning effect of the SPM solution.

[0040] like Figure 2 As shown, one or more first filters 15 are also provided on the first connecting pipeline, and the first filter 15 is provided between the first buffer tank 13 and the second heater 14. In this embodiment, the circulating SPM solution is filtered by the first filter 15, so as to avoid the SPM solution carrying particles during the circulation process and affecting the subsequent cleaning effect of the wafer. The first filter 15 can be provided on two pipelines respectively to improve the filtering efficiency of the circulating SPM.

[0041] See also Figure 2 , the wafer cleaning device also includes a second connecting pipe. The second cleaning tank 20 includes a second inner tank 21 and a second outer tank 22, the second inner tank 21 is used to store the SPM solution, and the second outer tank 22 is used to store the SPM solution overflowing from the second inner tank 21. The second connecting pipe is used to connect the second inner tank 21 and the second outer tank 22. In this embodiment, the second inner tank 21 and the second outer tank 22 are connected by the second connecting pipe, so that the fluidity of the liquid in the second cleaning tank 20 can be achieved, and the concentration of the solution at each position in the second cleaning tank 20 is ensured to be uniform, thereby achieving a better cleaning effect.

[0042] See also Figure 2, a second buffer tank 23 and a third heater 24 are arranged on the second connecting pipeline, the second buffer tank 23 is connected to the second outer tank 22, the second buffer tank 23 is also connected to the second inner tank 21, and the third heater 24 is arranged on the second connecting pipeline between the second buffer tank 23 and the second inner tank 21. In this embodiment, by arranging the second buffer tank 23 on the second connecting pipeline, the SPM solution in the second outer tank 22 can be buffered, and by arranging the third heater 24 on the second connecting pipeline, the circulating SPM solution can be heated, thereby improving the cleaning effect of the SPM solution. At the same time, the second buffer tank 23 can also facilitate the third heater 24 to heat the circulating SPM solution, thereby avoiding the SPM solution from flowing too fast in the second connecting pipeline, so that the SPM solution cannot be heated to the preset temperature range, thereby reducing the cleaning effect of the SPM solution.

[0043] See also Figure 2 One or more second filters 25 are further provided on the second connecting pipeline, and the second filter 25 is provided between the second buffer tank 23 and the third heater 24. In this embodiment, the SPM solution in circulation is filtered by the second filter 25, so as to prevent the SPM solution from carrying particles during the circulation process, thereby affecting the subsequent cleaning effect on the wafer.

[0044] In some of the embodiments, the preset temperature range is 80° C. to 100° C. In this embodiment, by setting the preset temperature range to 80° C. to 100° C., the cleaning effect of the SPM solution can be improved.

[0045] Continue to see Figure 2 A three-way valve 60 may also be provided on the second connecting pipeline to control the flow direction of the SPM solution. For example, when the SPM solution is replaced, the second cleaning tank 20 is connected to the storage 30. When the SPM solution is not replaced, the second connecting pipeline is connected to allow the second cleaning tank 20 to circulate internally.

[0046] Those skilled in the art should understand that the technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0047] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A wafer cleaning device, characterized in that: include: A first cleaning tank, used for storing the SPM solution and for performing a first cleaning on the wafer; A second cleaning tank, used for storing the SPM solution and for performing a second cleaning on the wafer; a storage tank, used for storing the SPM solution discharged from the second cleaning tank after the second cleaning tank cleans the wafer for the second time; A first heater, used to heat the SPM solution in the storage tank to a preset temperature range; The controller is used for controlling the storage tank to transport the SPM solution heated by the first heater to the preset temperature range to the first cleaning tank when the SPM solution is replaced in the first cleaning tank.

2. The wafer cleaning device according to claim 1, characterized in that: The wafer cleaning device further includes a concentration detector, which is used to detect the concentration of the SPM solution in the storage tank and send it to the controller when the SPM solution is replaced in the first cleaning tank; The controller is used to compare the concentration of the SPM solution in the storage tank with a preset concentration, and when the concentration of the SPM solution in the storage tank is not less than the preset concentration, control the storage tank to transport the SPM solution heated to the preset temperature range by the first heater to the first cleaning tank.

3. The wafer cleaning device according to claim 2, characterized in that: When the controller detects that the concentration of the SPM solution in the storage tank is less than the preset concentration, the controller controls the storage tank to discharge the SPM solution in the storage tank.

4. The wafer cleaning device according to claim 1, characterized in that: The wafer cleaning device also includes a first connecting pipe, the first cleaning tank includes a first inner tank and a first outer tank, the first inner tank is used to store SPM solution, and the first outer tank is used to store SPM solution overflowing from the first inner tank; wherein the first connecting pipe connects the first inner tank and the first outer tank.

5. The wafer cleaning device according to claim 4, characterized in that: The first communicating pipeline is provided with a first buffer tank and a second heater, the first buffer tank is communicated with the first outer tank, the first buffer tank is also communicated with the first inner tank, and the second heater is provided on the first communicating pipeline between the first buffer tank and the first inner tank.

6. The wafer cleaning device according to claim 5, characterized in that: The first communicating pipeline is further provided with a first filter, and the first filter is provided between the first buffer tank and the second heater.

7. The wafer cleaning device according to claim 1, characterized in that: The wafer cleaning device also includes a second connecting pipe, the second cleaning tank includes a second inner tank and a second outer tank, the second inner tank is used to store SPM solution, and the second outer tank is used to store SPM solution overflowed from the second inner tank; wherein the second connecting pipe connects the second inner tank and the second outer tank.

8. The wafer cleaning device according to claim 7, characterized in that: A second buffer tank and a third heater are provided on the second connecting pipeline. The second buffer tank is connected to the second outer tank, and the second buffer tank is also connected to the second inner tank. The third heater is provided on the second connecting pipeline between the second buffer tank and the second inner tank.

9. The wafer cleaning device according to claim 8, characterized in that: The second communicating pipeline is further provided with a second filter, and the second filter is provided between the second buffer tank and the third heater.

10. The wafer cleaning device according to claim 1, characterized in that: Further included is at least one filter disposed between the first heater and the storage tank.

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