Wafer cleaning apparatus

Abstract

The present application relates to a wafer cleaning apparatus. The wafer cleaning apparatus comprises a first cleaning tank, a second cleaning tank, a storage tank, a first heater and a controller, wherein an SPM solution which is discharged from the second cleaning tank is stored by means of the storage tank, and when SPM solution displacement is performed on the first cleaning tank, the storage tank is controlled by means of the controller to convey an SPM solution, which is heated to a preset temperature interval by the first heater, into the first cleaning tank. The problem of a tank-type SPM cleaning device or a combined tank-type and single-wafer SPM cleaning device being unable to further save on an SPM solution is solved, and reuse of the SPM solution is realized, thereby further saving on the SPM solution.

Description

Wafer cleaning equipment 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 single-wafer SPM cleaning equipment cannot meet the needs of most processes after sulfuric acid and hydrogen peroxide are mixed and diluted and then recycled, the amount of sulfuric acid consumed by the equipment is much greater than that of the tank-type equipment. Single-wafer SPM cleaning equipment consumes a large amount of SPM, while tank-type SPM cleaning equipment consumes less SPM. In terms of particle removal, tank-type SPM cleaning equipment is inferior to single-wafer SPM cleaning equipment, and more small particles are added. Generally speaking, tank-type SPM cleaning equipment is suitable for removing particles larger than 60nm, while single-wafer SPM cleaning equipment is suitable for removing particles smaller than 40nm.

[0003] Combining tank-type and single-wafer cleaning equipment can achieve greater SPM solution savings compared to single-wafer SPM cleaning equipment while ensuring particle removal capabilities below 40nm. However, as process requirements advance to remove particles below 26nm, current tank-type or tank-type and single-wafer SPM cleaning equipment can no longer achieve further SPM solution savings.

[0004] Summary of the Invention

[0005] An embodiment of the present application provides a wafer cleaning device that can further save sulfuric acid.

[0006] The wafer cleaning device provided in an embodiment of the present application includes:

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

[0008] a second cleaning tank, for storing the SPM solution and for performing a second cleaning on the wafer;

[0009] a storage tank, used to store the SPM solution discharged from the second cleaning tank after the second cleaning tank cleans the wafer for the second time;

[0010] a first heater, configured to heat the SPM solution in the storage tank to a preset temperature range;

[0011] The controller is configured to control 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.

[0012] In some 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.

[0013] 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.

[0014] 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.

[0015] In some embodiments, a first buffer tank and a second heater are provided on the first connecting pipe, the first buffer tank is connected to the first outer tank, and the first buffer tank is also connected to the first inner tank, and the second heater is provided on the first connecting pipe between the first buffer tank and the first inner tank.

[0016] In some embodiments, a first filter is further provided on the first communicating pipe, and the first filter is provided between the first buffer tank and the second heater.

[0017] 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.

[0018] In some embodiments, a second buffer tank and a third heater are provided on the second connecting pipe, the second buffer tank is connected to the second outer tank, and the second buffer tank is also connected to the second inner tank, and the third heater is provided on the second connecting pipe between the second buffer tank and the second inner tank.

[0019] In some embodiments, a second filter is further provided on the second communicating pipe, and the second filter is provided between the second buffer tank and the third heater.

[0020] In some of the embodiments, the system further comprises at least one filter disposed between the first heater and the storage tank.

[0021] To sum up, 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 SPM solution, and further saves SPM solution.

[0022] The 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.

[0023] Summary of the Figures

[0024] The features and properties of the present invention are further described by the following examples and accompanying drawings.

[0025] FIG1 is a structural block diagram of a wafer cleaning device according to an embodiment of the present application;

[0026] FIG2 is a schematic structural diagram of a wafer cleaning device according to an embodiment of the present application.

[0027] Preferred embodiments of the present invention

[0028] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the present application is described and illustrated below in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely used to explain this application and are not intended to limit this application. Based on the embodiments provided in this application, all other embodiments obtained by those of ordinary skill in the art without making any creative efforts are within the scope of protection of this application.

[0029] Unless otherwise defined, the technical or scientific terms used in this application should have the ordinary meaning understood by a person of ordinary skill in the technical field to which this application belongs. The words "one", "a", "the" and the like used in this application do not indicate a limit on quantity and may indicate the singular or plural. The terms "include", "comprise", "have" and any variations thereof used 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 that are inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like used in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The word "multiple" used in this application means greater than or equal to two. "And / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, "A and / or B" can mean: 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 this application are merely used to distinguish similar objects and do not represent a specific ordering of the objects.

[0030] An embodiment of the present application provides a wafer cleaning device. FIG1 is a structural block diagram of a wafer cleaning device according to an embodiment of the present application. As shown in FIG1 , 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 a first cleaning on the wafer. The second cleaning tank 20 is used to store the SPM solution and is used to perform a second cleaning on 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 SPM solution is replaced in the first cleaning tank 10, 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.

[0031] It should be noted that cleaning equipment is typically equipped with two SPM tanks. The first tank is used for the first cleaning of wafers, so its SPM solution concentration is relatively low. The second tank is used for the second cleaning of wafers. The wafers are cleaner than the first cleaning, so it consumes less SPM solution than the first cleaning, and its SPM solution concentration is relatively higher. 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 solution in both cleaning tanks is completely discharged and new SPM solution is replenished from the factory. However, the wafer cleaning device provided in this application discharges the higher-concentration SPM in the second cleaning tank 20 into the storage tank 30. When the first cleaning tank 10 is performing the SPM solution replacement, the SPM in the storage tank 30 can be supplied to the first cleaning tank 10. This reduces the amount of SPM solution replenished from the factory, realizes the secondary use of the higher-concentration SPM solution, extends the service life, and saves the amount of SPM solution used.

[0032] Specifically, the SPM solution includes sulfuric acid and hydrogen peroxide. The saving of SPM solution usage described in the embodiments of the present application can be understood as saving the usage of sulfuric acid in the SPM solution, as shown in Table 1 below, where 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.

[0033] Table 1 Sulfuric acid usage

[0034] As can be seen from Table 1, the wafer cleaning device provided in this application can further save sulfuric acid in the SPM solution on the basis of the existing tank / tank and single-wafer cleaning equipment.

[0035] In some embodiments, at least one filter may be further provided 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 .

[0036] In some embodiments, the SPM solution can be replaced synchronously in the first cleaning tank 10 and the second cleaning tank 20. 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. 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.

[0037] In some embodiments, the wafer cleaning apparatus further includes a concentration detector. When the SPM solution is replaced in the first cleaning tank 10, the concentration detector detects the concentration of the SPM solution in the storage tank 30 and sends the information to the controller 50. The controller 50 compares the concentration of the SPM solution in the storage tank 30 with a preset concentration. If the concentration of the SPM solution in the storage tank 30 is not less than the preset concentration, the controller 50 controls the storage tank 30 to transfer the SPM solution, which has been heated to a preset temperature range by the first heater 40, to the first cleaning tank 10. The concentration detector monitors the concentration of the SPM solution in the storage tank 30 to prevent the SPM solution in the storage tank 30 from being too low, thereby affecting the cleaning performance of the first cleaning tank 10. The preset concentration can be determined by process requirements.

[0038] 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.

[0039] 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.

[0040] Referring to FIG. 2 , in some embodiments, the wafer cleaning apparatus 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 that overflows 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, connecting the first inner tank 11 and the first outer tank 12 via the first connecting pipe can achieve fluidity of the liquid in the first cleaning tank 10, ensuring uniform solution concentration at all locations in the first cleaning tank 10, thereby achieving a better cleaning effect.

[0041] Continuing with Figure 2 , a first buffer tank 13 and a second heater 14 are provided in the first connecting pipe. The first buffer tank 13 is in communication with the first outer tank 12, which is also in communication with the first inner tank 11. The second heater 14 is provided in the first connecting pipe between the first buffer tank 13 and the first inner tank 11. In this embodiment, the provision of the first buffer tank 13 in the first connecting pipe allows for buffering of the SPM solution in the first outer tank 12. The provision of the second heater 14 in the first connecting pipe allows for heating of the circulating SPM solution, thereby improving the cleaning effect of the SPM solution. Furthermore, the provision of the first buffer tank 13 facilitates heating of the circulating SPM solution by the second heater 14, preventing the SPM solution from flowing too rapidly in the first connecting pipe, preventing the SPM solution from being heated to a predetermined temperature range and thus reducing the cleaning effect of the SPM solution.

[0042] As shown in Figure 2, one or more first filters 15 are also provided in the first connecting pipeline. These filters 15 are positioned between the first buffer tank 13 and the second heater 14. In this embodiment, the circulating SPM solution is filtered by the first filters 15, preventing particles from being carried along by the SPM solution and affecting subsequent wafer cleaning. The first filters 15 can be positioned in both pipelines to improve the filtration efficiency of the circulating SPM.

[0043] Referring to Figure 2 , the wafer cleaning apparatus further 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 that overflows from the second inner tank 21. The second connecting pipe connects the second inner tank 21 and the second outer tank 22. In this embodiment, the second connecting pipe connects the second inner tank 21 and the second outer tank 22, thereby ensuring fluidity of the liquid in the second cleaning tank 20 and a uniform concentration of the solution at all locations within the second cleaning tank 20, thereby achieving a better cleaning effect.

[0044] Referring to Figure 2 , a second buffer tank 23 and a third heater 24 are provided in the second connecting pipe. The second buffer tank 23 is in communication with the second outer tank 22, which is also in communication with the second inner tank 21. The third heater 24 is provided in the second connecting pipe between the second buffer tank 23 and the second inner tank 21. In this embodiment, the second buffer tank 23 in the second connecting pipe buffers the SPM solution in the second outer tank 22, while the third heater 24 heats the circulating SPM solution, thereby improving the cleaning effect of the SPM solution. Furthermore, the second buffer tank 23 facilitates heating of the circulating SPM solution by the third heater 24, preventing the SPM solution from flowing too fast in the second connecting pipe, which could prevent the SPM solution from being heated to the preset temperature range and thus reducing the cleaning effect of the SPM solution.

[0045] As shown in FIG2 , one or more second filters 25 are further provided in the second connecting line, and the second filters 25 are disposed between the second buffer tank 23 and the third heater 24. In this embodiment, the circulating SPM solution is filtered by the second filters 25 to prevent the SPM solution from carrying particles during circulation, which could affect the subsequent cleaning effect on the wafers.

[0046] In some 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.

[0047] 2 , a three-way valve 60 may be further provided on the second connecting line 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 line is connected to allow the second cleaning tank 20 to circulate internally.

[0048] Those skilled in the art should understand that the various technical features of the above-described embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the various 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.

[0049] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended 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.

Images