Grinding fluid mixing and supplying system

Abstract

The present invention provides a grinding fluid mixing and supplying system, comprising: a raw material supplying system for supplying a raw material for preparing a grinding fluid to a grinding fluid mixing system; the grinding fluid mixing system comprises three mixing barrels, an inner circulation module and an outer circulation module. The internal circulation module comprises a circulation pump and a circulation pipeline which are communicated with each other, the circulation pipeline is arranged in each mixing barrel, and the circulation of the grinding liquid in the mixing barrels is realized through the circulation pump; the outer circulation module comprises an outlet module and a backflow module which are arranged on each mixing barrel, the outlet modules are used for conveying the grinding liquid in the mixing barrels into target equipment, and the backflow modules are used for conveying the grinding liquid in the target equipment into the mixing barrels; the device further comprises a nitrogen humidification module, and the nitrogen humidification module communicates with each mixing barrel and is used for supplementing wet nitrogen into the mixing barrels. According to the scheme, an internal circulation and external circulation mode is combined with a nitrogen humidification module, so that grinding liquid is diluted and mixed uniformly, and the grinding liquid is prevented from crystallizing.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and in particular to a slurry mixing and supply system. Background Technology

[0002] Chemical mechanical polishing (CMP) is a technique that uses the combined physical and chemical effects of a slurry to perform micro-cutting on the surface of silicon wafers. Large-scale semiconductor wafer manufacturing requires a large amount of slurry, and the quality of the automated slurry dilution and mixing supply system directly affects the CMP process outcome.

[0003] A key characteristic of polishing slurries is their tendency to crystallize upon contact with air, leading to larger abrasive particles and consequently affecting the yield of CMP processes. Nitrogen humidification systems are typically used to mitigate this risk, but existing systems are complex and their effectiveness is unpredictable. Furthermore, with the rapid development of the semiconductor industry, some polishing slurries exhibit antioxidant properties and are prone to bacterial growth. Additionally, the removal of pigment contaminants from the slurry is necessary. Therefore, besides controlling the slurry's dilution concentration, hydrogen peroxide (H2O2) is required for slurries with specific characteristics, and the dosage must be precisely controlled. To meet these precision control requirements, even more precise control over the amount of the added solution is needed.

[0004] It should be noted that the above introduction to the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of this application and facilitating understanding by those skilled in the art. It should not be assumed that these technical solutions are known to those skilled in the art simply because they have been described in the background section of this application. Summary of the Invention

[0005] The purpose of this invention is to provide a grinding slurry mixing and supply system to reduce grinding slurry crystallization.

[0006] To address the aforementioned problems, in a first aspect, this application provides a grinding slurry mixing and supply system, comprising: A raw material supply system is used to supply the raw materials for preparing the grinding slurry to the grinding slurry mixing system; The grinding fluid mixing system includes three mixing tanks, an inner circulation module, and an outer circulation module; The internal circulation module includes a circulating pump and a circulating pipeline connected together. Each of the mixing tanks is provided with the circulating pipeline, and the grinding liquid is circulated in the mixing tank through the circulating pump. The external circulation module includes an outlet module and a return module disposed on each of the mixing tanks. The outlet module is used to transport the grinding fluid in the mixing tank to the target device, and the return module is used to transport the grinding fluid in the target device to the mixing tank. It also includes a nitrogen humidification module, which is connected to each of the mixing tanks and is used to replenish the mixing tanks with wet nitrogen.

[0007] This solution uses an internal circulation + external circulation mode to ensure uniform dilution and mixing of the grinding slurry and prevent crystallization.

[0008] The nitrogen humidification module includes a humidifier, a foamer, a nitrogen inlet, a pure water inlet, and a wet nitrogen pipeline. The pure water inlet supplies pure water to the humidifier. The foamer is located within the humidifier, and its input end is connected to the nitrogen inlet to convert nitrogen into bubbles, which then mix with the pure water to form wet nitrogen. The wet nitrogen pipeline is connected to each mixing tank to replenish the mixing tank with wet nitrogen. This optimized nitrogen humidifier features a simpler structure and is easier to install and maintain.

[0009] The nitrogen humidification module also includes three water level sensors.

[0010] The nitrogen humidification module also includes a flow meter and a pressure sensor, which are used to monitor the output flow rate and output pressure of the humid nitrogen.

[0011] The raw material supply system includes a pure water supply module, an H2O2 supply module, and a grinding solution supply module, which are respectively connected to each of the mixing tanks. The pure water supply module, the H2O2 supply module, and the grinding solution supply module are respectively located on the top of each of the mixing tanks.

[0012] It also includes a KOH supply module, which includes a KOH supply pump and a KOH supply pipeline. The KOH supply pipeline is connected to each of the mixing tanks and is used to provide KOH solution to clean the mixing tanks.

[0013] The external circulation system includes a grinding fluid output module, a filtration module, an outlet module, and a reflux module connected in sequence. The grinding fluid output module includes an output pump and an output pipeline, which is connected to the mixing tank and used to extract the grinding fluid from the mixing tank and deliver it to the filtration module. The filtration module is used to filter the grinding fluid. The outlet module is located at the top of each mixing tank and is connected to the filtration module to deliver the filtered grinding fluid to the target device. The reflux module is located at the top of each mixing tank and is connected to the target device to return the grinding fluid to the corresponding mixing tank.

[0014] It also includes a heat exchange module, which is disposed outside each of the mixing tanks and is connected to the reflux module and the filter module.

[0015] It also includes a drainage system, which comprises a waste liquid module, a dredging module, and a KOH dredging module.

[0016] A magnetic levitation mixing pump is installed at the bottom of the mixing tank, and a stirring nozzle is also installed inside the mixing tank. The stirring nozzle works in conjunction with the magnetic levitation mixing pump to circulate and mix the grinding liquid inside the mixing tank.

[0017] Compared with the prior art, the beneficial effects of the present invention mainly include the following: 1) The internal circulation + external circulation mode ensures uniform dilution and mixing of the grinding fluid and prevents crystallization of the grinding fluid; 2) The nitrogen humidification module has a simple structure, which can ensure that the wet nitrogen meets the mixing and use standards of the grinding fluid and facilitate subsequent maintenance and replacement; 3) The three mixing units work together and adopt a fully closed circulation design to achieve safe and large-volume automatic supply of grinding fluid; 4) The system structure is miniaturized, saving on-site installation space and improving installation convenience and maintenance convenience. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the specific embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A front view of a grinding fluid mixing and supply system provided by the present invention.

[0020] Figure 2 A rear-view axis view of a grinding fluid mixing and supply system provided by the present invention.

[0021] Figure 3 This is a schematic diagram of the nitrogen humidification module provided by the present invention.

[0022] Figure 4 This is a schematic cross-sectional view of the mixing tank provided by the present invention.

[0023] Figure 5 The diagram shows the internal circulation module, KOH supply module, and waste liquid module provided by this invention.

[0024] Figure 6 This is a schematic diagram of the modules on the top of the mixing tank provided by the present invention.

[0025] Figure 7 This is a schematic diagram of the heat exchange module provided by the present invention.

[0026] Figure 8 A schematic diagram of the grinding fluid output module and the filter module provided by the present invention.

[0027] Figure label: 1-Mixing tank; 11-Outlet module; 12-Reflux module; 13-Pure water supply module; 14-H2O2 supply module; 15-Grinding solution supply module; 16-Magnetic levitation mixing pump; 17-Stirring nozzle; 2-Internal circulation module; 21-Circulation pump; 22-Circulation pipeline; 3-Nitrogen humidification module; 31-Humidifier; 32-Nitrogen interface; 33-Pure water interface; 34-Wet nitrogen pipeline; 4-KOH supply module; 41-KOH supply pump; 42-KOH supply pipeline; 5- Grinding slurry output module; 51- Output pump; 52- Output pipeline; 6-Filter module; 7-Heat exchange module; 8-Waste liquid module. Detailed Implementation

[0028] The foregoing and other technical contents, features, and effects of the present invention will be clearly presented in the following detailed description of a preferred embodiment with reference to the accompanying drawings. The directional terms mentioned in the following embodiments, such as up, down, left, right, front, or back, are merely for reference to the accompanying drawings. Therefore, the directional terms used are for illustrative purposes and not for limiting the present invention.

[0029] The embodiments of this application will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this application to facilitate a better understanding of the application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0030] Example 1: Please refer to Figures 1-8 As shown, this embodiment provides a grinding slurry mixing and supply system, including a raw material supply system and a grinding slurry mixing system connected to each other; wherein, the raw material supply system is used to supply the raw materials required for preparing the grinding slurry to the grinding slurry mixing system, and the grinding slurry mixing system is used to dilute and fully mix the raw materials, and to provide the required grinding slurry to the target equipment (usually a downstream CMP machine).

[0031] In this embodiment, the raw material supply system typically includes a pure water supply module 13, an H2O2 supply module 14, and a grinding fluid supply module 15, depending on the raw materials required for preparing the grinding slurry. The grinding slurry mixing system includes three mixing tanks 1, an internal circulation module 2, and an external circulation module. Each mixing tank 1 is equipped with a pure water supply module 13, an H2O2 supply module 14, and a grinding fluid supply module 15 on its top to provide the raw materials for preparing the grinding slurry.

[0032] In this embodiment, in order to achieve thorough mixing of the grinding slurry in the mixing tank 1 and reduce crystallization, a dual circulation system is set up, namely an inner circulation module 2 and an outer circulation module. The inner circulation module 2 includes a circulating pump 21 and a circulating pipeline 22 connected to each other. Each mixing tank 1 is provided with a circulating pipeline 22, and the grinding slurry is circulated in the mixing tank 1 through the circulating pump 21.

[0033] refer to Figure 4 As shown, a magnetic levitation mixing pump 16 is provided at the bottom of each mixing tank 1, and a stirring nozzle 17 is also provided inside the mixing tank 1. The input end of the stirring nozzle 17 is connected to the circulation pipeline 22. The stirring nozzle 17 works with the magnetic levitation mixing pump 16 to circulate and mix the grinding liquid in the mixing tank 1.

[0034] The mixing tank 1 also includes an electronic scale, which is usually located under the support of the mixing tank 1, to control the input solution ratio and ensure accurate dilution ratio.

[0035] The external circulation module includes an outlet module 11 and a return module 12 installed on each mixing tank 1. The outlet module 11 is used to transport the grinding fluid in the mixing tank 1 to the target equipment, and the return module 12 is used to transport the grinding fluid in the target equipment to the mixing tank 1. To ensure that the grinding fluid transported to the target equipment meets the process standards, a grinding fluid output module 5 and a filter module 6 are also installed before the outlet module 11. Figure 8 As shown, the grinding slurry output module 5 and the filter module 6 are connected. The grinding slurry output module 5 is located at the bottom of the mixing tank 1. The grinding slurry output module 5 includes an output pump 51 and an output pipeline 52. The output pipeline 52 is connected to the mixing tank 1 and is used to extract the grinding slurry from the mixing tank 1 and transport it to the filter module 5 for filtration. The filter module 5 is connected to the outlet module 11 and is used to transport the filtered grinding slurry to the target equipment. The return module 12 is located at the top of each mixing tank 1 and is connected to the target equipment respectively. It is used to return the grinding slurry to the corresponding mixing tank.

[0036] In this embodiment, in order to prevent the crystallization of the grinding slurry, a nitrogen humidification module 3 is also provided. The nitrogen humidification module 3 is connected to each mixing tank 1 and is used to replenish the mixing tank 1 with wet nitrogen. Figure 3 This is a schematic diagram of the nitrogen humidification module provided by the present invention. (Reference) Figure 3 As shown, Figure 3 In the diagram, 'a' represents a schematic of nitrogen humidification module 3. Figure 3Figure 'b' shows a partially enlarged schematic diagram of the nitrogen humidification module 3. The nitrogen humidification module 3 includes a pair of humidifiers 31, each with a nitrogen inlet 32 ​​and a pure water inlet 33. A foamer (not shown) is located on the bottom side inside each humidifier 31. The pure water inlet 33 supplies pure water to the humidifier 31. The input end of the foamer is connected to the nitrogen inlet 32. The foamer has dense micropores inside. After high-purity nitrogen at a suitable pressure is introduced through the nitrogen inlet 32, the high-purity nitrogen enters the humidifier 31 through the foamer and is transformed into fine bubbles. The nitrogen bubbles can mix with the ultrapure water in the humidifier 31 to form a micro-mist "water mist" (i.e., wet nitrogen). The output end of the nitrogen humidification module 3 is connected to each mixing tank 1 through a wet nitrogen pipeline 34 to replenish the wet nitrogen in the mixing tank 1.

[0037] In this embodiment, water level sensors are also installed at three different locations inside the humidifier 31 to detect the level of pure water inside the nitrogen humidification module 3 in real time. This ensures a certain water level and also prevents the water level from becoming too high, thus ensuring the normal operation of the nitrogen humidification module 3.

[0038] The nitrogen humidification module 3 also includes a flow meter and a pressure sensor, which can usually be installed at the wet nitrogen pipeline 34 to monitor the output flow rate and output pressure of the wet nitrogen, respectively.

[0039] In this embodiment, a heat exchange module 7 is also included. The heat exchange module 7 is disposed outside each mixing tank 1 and is connected to the reflux module 12 and the filter module 6 for cooling the grinding fluid. (Reference) Figure 7 As shown, the heat exchange module 7 is constructed with 304 stainless steel pipes and has a painted surface. It is sealed with flanges at the top and bottom, and has inlet and outlet ports at the top and bottom respectively. The internal structure is a coil type, with grinding fluid inside the coil and cooling water outside the coil. The flowing cooling water cools the grinding fluid inside the tube.

[0040] In addition, a KOH supply module 4 is provided for cleaning the mixing tank 1. The KOH supply module 4 is shared by the three mixing tanks 1. The KOH supply module 4 includes a KOH supply pump 41 and a KOH supply pipeline 42. The KOH supply pipeline 42 is connected to each mixing tank 1, so that the KOH solution is delivered to the corresponding mixing tank 1 for cleaning under the action of the KOH supply pump 41.

[0041] In this embodiment, the grinding slurry mixing and supply system further includes a drainage system, which comprises a waste liquid module 8, a dredging module, and a KOH dredging module. The waste liquid module 8 is responsible for extracting waste liquid from each liquid-receiving structure within the grinding slurry mixing and supply system.

[0042] In this application, three mixing units (i.e., three mixing tanks 1) are provided, and each mixing unit is provided with a corresponding grinding fluid output module 5 to extract the mixed grinding fluid from the mixing tank 1 and send it to the target equipment for external circulation; at the same time, an internal circulation is also provided, that is, the grinding fluid is circulated and mixed in each mixing tank 1 through the internal circulation module 2; the internal circulation module 2 includes two sets of circulation pumps 21, which are used and standby to prevent the occurrence of pump failure.

[0043] In use, the grinding fluid is first prepared and diluted in the mixing tank 1 and then stored in the mixing tank 1. Then, the internal circulation module 2 performs internal circulation. At the same time, the grinding fluid output module 5, the filter module 6, the outlet module 11 and the group return module 12 work together to perform external circulation using the target equipment. During the external circulation process, the grinding fluid can be filtered, sampled, and tested with a concentration meter to ensure that the grinding fluid supplied to the downstream target equipment meets the usage requirements.

[0044] In this system, each critical component is controlled by a pneumatic valve, enabling automated operation. Manual valves are also installed before and after the pneumatic valves for added safety. Thus, when maintaining or replacing valve components, the valves before and after each module are closed, and the pipeline is cleaned by adding water and air via the service system before maintenance is performed, making maintenance convenient.

[0045] The common English terms or letters used in this invention for clarity of description are for illustrative purposes only and are not limiting interpretations or specific uses. They should not be used to limit the scope of protection of this invention based on their possible Chinese translations or specific letters.

[0046] It should also be noted that in this article, relational terms such as “first” and “second” are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

Claims

1. A grinding slurry mixing and supply system, characterized in that, include: A raw material supply system is used to supply the raw materials for preparing the grinding slurry to the grinding slurry mixing system; The grinding fluid mixing system includes three mixing tanks, an inner circulation module, and an outer circulation module; The internal circulation module includes a circulating pump and a circulating pipeline connected together. Each of the mixing tanks is provided with the circulating pipeline, and the grinding liquid is circulated in the mixing tank through the circulating pump. The external circulation module includes an outlet module and a return module disposed on each of the mixing tanks. The outlet module is used to transport the grinding fluid in the mixing tank to the target device, and the return module is used to transport the grinding fluid in the target device to the mixing tank. It also includes a nitrogen humidification module, which is connected to each of the mixing tanks and is used to replenish the mixing tanks with wet nitrogen.

2. The grinding fluid mixing and supply system according to claim 1, characterized in that, The nitrogen humidification module includes a humidifier, a foamer, a nitrogen interface, a pure water interface, and a wet nitrogen pipeline; The pure water interface is used to supply pure water to the humidifier; The foamer is installed in the humidifier, and the input end of the foamer is connected to the nitrogen interface to convert nitrogen into bubbles and mix them with pure water to form wet nitrogen. The wet nitrogen pipeline is connected to each of the mixing tanks and is used to replenish the mixing tanks with wet nitrogen.

3. The grinding fluid mixing and supply system according to claim 2, characterized in that, The nitrogen humidification module also includes three water level sensors.

4. The grinding fluid mixing and supply system according to claim 3, characterized in that, The nitrogen humidification module also includes a flow meter and a pressure sensor, which are used to monitor the output flow rate and output pressure of the humid nitrogen.

5. The grinding fluid mixing and supply system according to claim 1, characterized in that, The raw material supply system includes a pure water supply module, an H2O2 supply module, and a grinding solution supply module, which are respectively connected to each of the mixing tanks. The pure water supply module, the H2O2 supply module, and the grinding solution supply module are respectively located on the top of each of the mixing tanks.

6. The grinding fluid mixing and supply system according to claim 1, characterized in that, It also includes a KOH supply module, which includes a KOH supply pump and a KOH supply pipeline. The KOH supply pipeline is connected to each of the mixing tanks and is used to provide KOH solution to clean the mixing tanks.

7. The grinding fluid mixing and supply system according to claim 1, characterized in that, The external circulation system includes a grinding fluid output module, a filter module, an outlet module, and a return module connected in sequence. The grinding fluid output module includes an output pump and an output pipeline. The output pipeline is connected to the mixing tank and is used to extract the grinding fluid from the mixing tank and deliver it to the filtration module. The filter module is used to filter the grinding fluid; The outlet module is located on the top of each of the mixing tanks and is connected to the filter module to deliver the filtered grinding liquid to the target device. The reflux module is located on the top of each of the mixing tanks and is connected to the target device, and is used to reflux the grinding fluid back into the corresponding mixing tank.

8. The grinding fluid mixing and supply system according to claim 7, characterized in that, It also includes a heat exchange module, which is disposed outside each of the mixing tanks and is connected to the reflux module and the filter module.

9. The grinding fluid mixing and supply system according to claim 1, characterized in that, It also includes a drainage system, which comprises a waste liquid module, a dredging module, and a KOH dredging module.

10. The grinding slurry mixing and supply system according to claim 1, characterized in that, A magnetic levitation mixing pump is installed at the bottom of the mixing tank, and a stirring nozzle is also installed inside the mixing tank. The stirring nozzle works in conjunction with the magnetic levitation mixing pump to circulate and mix the grinding liquid inside the mixing tank.

Images