Developing solution dilution system and method

Abstract

The invention provides a developing solution dilution system and method, and the developing solution dilution system comprises a mixing storage tank, the top of the mixing storage tank is sequentially provided with a stock solution supply pipeline, a pure water supply pipeline and a nitrogen supply pipeline, and the support leg of the mixing storage tank is provided with a canning weighing device; the pneumatic pump is connected to the lower end of the mixing storage tank through a first liquid conveying pipeline; the inlet end of the heat exchanger is connected with the pneumatic pump through a second liquid conveying pipeline, the outlet end of the heat exchanger is connected with a third liquid conveying pipeline, and the end, away from the heat exchanger, of the third liquid conveying pipeline is connected with a backflow pipeline and an output pipeline through a three-way connector. And the other end of the backflow pipeline is connected with the top of the mixing storage tank. High-precision flow control and automatic dilution are achieved through the supply module and the adjusting module, the stability of the dilution system is greatly guaranteed, the dilution concentration qualification rate is increased, and the manufacturing cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of developer dilution, and in particular to a developer dilution system and method. Background Art

[0002] In the field of semiconductor precision processing technology, photolithography is often used. Positive photolithography developers and negative photolithography developers are used in the photolithography process. Positive photolithography has good contrast and the generated graphics have good resolution. The mainstream process in the industry is to use orthogonal photolithography developers. The common positive photolithography developer is a 2.38% tetramethylammonium hydroxide (TMAH) aqueous solution.

[0003] In recent years, due to the rapid development of communication and artificial intelligence technology, integrated circuits are pursuing high density and integration, and the requirements for wafer surface patterning are constantly increasing. In order to obtain high-contrast, high-resolution wafers, this puts high demands on the quality of the developer used in the photolithography process. For example, the qualified concentration of 2.38% tetramethylammonium hydroxide (TMAH) aqueous solution of positive photolithography developer is required to be ±0.003%.

[0004] At present, integrated circuit manufacturers mainly use two methods to obtain developers that meet the required concentrations. Method 1: Purchase developers that have been prepared with a certain concentration from chemical suppliers. For manufacturers with a large daily consumption of developer, they need to purchase a large amount of diluent, which not only requires a large amount of space and storage tanks, but also has high transportation costs. Method 2: Purchase developer stock of a certain concentration from chemical suppliers, and then dilute it to the standard concentration. However, this method has very high requirements for the design of the dilution system and the dilution method. Manufacturers do not have such capabilities, and the concentration will be unqualified many times during the initial debugging, which not only wastes a lot of time, but also causes great economic losses. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a developer dilution system and method, and the specific technical solution is as follows:

[0006] A developer dilution system, comprising:

[0007] A mixing tank, wherein a raw liquid supply pipeline, a pure water supply pipeline and a nitrogen supply pipeline are sequentially arranged on the top of the mixing tank, a supply regulating module is provided on the raw liquid supply pipeline and the pure water supply pipeline, a humidifier module is provided on the nitrogen supply pipeline, and a canned weighing device is provided at the foot of the mixing tank;

[0008] A pneumatic pump connected to the lower end of the mixing tank through a first liquid infusion pipeline;

[0009] A heat exchanger, wherein the inlet end of the heat exchanger is connected to the pneumatic pump through a second infusion pipeline, the outlet end of the heat exchanger is connected to a third infusion pipeline, the end of the third infusion pipeline away from the heat exchanger is connected to a reflux pipeline and an output pipeline respectively through a three-way joint, the other end of the reflux pipeline is connected to the top of the mixing storage tank, the reflux pipeline is provided with a first valve, and the output pipeline is provided with a second valve.

[0010] In a preferred implementation, the number of the pneumatic pumps is at least two, and at least two of the pneumatic pumps are connected in parallel and commonly connected between the first infusion pipeline and the second infusion pipeline.

[0011] In a preferred implementation, the system further includes:

[0012] A cooler is connected to the heat exchanger.

[0013] In a preferred implementation, at least two concentration meters are connected in parallel to the third infusion pipeline.

[0014] A developer dilution method, using the developer dilution system, specifically comprises the following steps:

[0015] S1: Calculating a first target weight of pure water and a second target weight of the developer stock solution according to a required developer dilution value, a developer stock solution concentration value, and a developer concentration value after dilution;

[0016] S2: The pure water supply pipeline outputs pure water, which is regulated by the supply regulating module and then input into the mixing tank. When the canned weighing device determines that the weight of the pure water reaches the first target weight, the supply regulating module shuts off the pure water supply;

[0017] S3: The developer stock solution is output from the stock solution supply pipeline, and after being adjusted by the supply adjustment module, it is input into the mixing storage tank. When the tank weighing device determines that the developer stock solution has reached the second target weight, the supply adjustment module closes the developer stock solution supply;

[0018] S4: Open the first valve, close the second valve, set the cycle time, and use the pneumatic pump to extract the pure water and developer solution in the mixing tank, pass through the heat exchanger, and then input into the mixing tank through the reflux pipe;

[0019] S5: After the set cycle time, the concentration of the diluted developer is detected and determined by a concentration meter;

[0020] S6: If the concentration of the diluted developer is qualified, the first valve is closed, the second valve is opened, and the pneumatic pump extracts the diluted developer in the mixing tank. At the same time, the nitrogen supply pipeline inputs nitrogen into the mixing tank through the humidification module, and the diluted developer is sent to the next process through the output pipeline. If the detected concentration of the diluted developer is high, the third target weight of pure water to be added is calculated first, and the supply adjustment module starts the pure water supply. When the canned weighing device determines that the weight of the pure water reaches the third target weight, the supply adjustment module turns off the pure water supply, and then jumps back to step S4. If the detected concentration of the diluted developer is low, the fourth target weight of the pure water to be added and the fifth target weight of the developer stock solution are calculated again. The supply adjustment module first turns on the pure water supply. When the canned weighing device determines that the weight of the pure water reaches the fourth target weight, the supply adjustment module turns off the pure water supply and turns on the developer stock solution supply. When the canned weighing device determines that the developer stock solution reaches the fifth target weight, the supply adjustment module turns off the developer stock solution supply, and then jumps back to step S4.

[0021] Beneficial effects of the present invention:

[0022] The supply regulating module in the present invention has the function of automatic switching of large and small valves. The present invention realizes high-precision flow control and automatic dilution through the supply module regulating module, greatly ensures the stability of the dilution system, improves the qualified rate of dilution concentration, and reduces manufacturing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The figure is a schematic diagram of the process of the developer dilution system in the present invention.

[0024] In the figure: 101, raw liquid supply pipeline; 102, pure water supply pipeline; 103, supply adjustment module; 104, nitrogen supply pipeline; 105, humidifier module; 106, mixing storage tank; 107, canned weighing device; 108, pneumatic pump; 109, heat exchanger; 110, cooler; 111, concentration meter; 112, first valve; 113, second valve. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0026] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0027] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise clearly and specifically defined.

[0028] In the present invention, unless otherwise clearly specified and limited, terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be connected, detachably connected, or integrated; it can be mechanically connected or electrically connected; it can be directly connected or indirectly connected through an intermediate medium, or it can be the internal connection of two elements.

[0029] like Figure 1 As shown, a developer dilution system comprises:

[0030] A mixing tank 106, the top of which is provided with a stock solution supply pipeline 101, a pure water supply pipeline 102 and a nitrogen supply pipeline 104 in sequence, the stock solution supply pipeline 101 and the pure water supply pipeline 102 are provided with a supply regulating module 103, the supply regulating module 103 has a large and small valve automatic switching function, which can not only shorten the addition time of the stock solution and the pure water, but also improve the addition accuracy of the stock solution and the pure water, and ensure the accuracy of the final developer dilution concentration, the nitrogen supply pipeline 104 is provided with a humidifier module 105, Since the aqueous solution of tetramethylammonium hydroxide (TMAH) has an ammonia smell and is easy to absorb CO2 in the air, the present invention humidifies the nitrogen through a humidification module, while ensuring the internal air pressure of the mixing storage tank 106, reducing the volatilization of the developer and isolating the developer from contacting the air, further ensuring the accuracy of the final developer dilution concentration. The support leg of the mixing storage tank 106 is provided with a canned weighing device 107, which is an industrial-grade C3 electronic scale with a graduation value of 1 / 14000. The high-precision electronic scale ensures the stability of the concentration during large-scale dilution.

[0031] A pneumatic pump 108 is connected to the lower end of the mixing tank 106 through a first infusion pipeline. The number of the pneumatic pumps 108 is at least 2, and at least 2 pneumatic pumps 108 are connected in parallel and connected between the first infusion pipeline and the second infusion pipeline. The pneumatic pump 108 is used for circulation and transportation. A dual pneumatic pump 108 design is adopted, one for use and one for backup, to ensure the stability and continuity of the operation of the developer dilution system.

[0032] During the dilution process of the developer, the pneumatic pump 108 will circulate and transport the diluted developer for a certain period of time. During the circulation process of the pneumatic pump 108, the internal diaphragm of the pneumatic pump 108 will heat up due to long-term operation, which will drive the developer to heat up as well, accelerate the volatilization of the developer, and cause the final developer dilution concentration value to fluctuate. For this reason, the present invention is equipped with a heat exchanger 109, and the inlet end of the heat exchanger 109 is connected to the pneumatic pump 108 through a second infusion pipeline. The present invention takes away the heat generated during the circulation process through the heat exchanger 109, keeps the temperature of the developer at a stable value that is not easy to volatilize, and ensures the accuracy of the final developer concentration after dilution. The outlet end of the heat exchanger 109 is connected to the third infusion pipeline, and one end of the third infusion pipeline away from the heat exchanger 109 is connected to the reflux pipeline and the output pipeline respectively through a three-way joint, and the other end of the reflux pipeline is connected to the top of the mixing storage tank 106, and the reflux pipeline is provided with a first valve 112, and the output pipeline is provided with a second valve 113.

[0033] In a preferred implementation, the system further includes: a cooler 110, wherein the cooler 110 is connected to the heat exchanger 109, and the cooler 110 has temperature regulation and monitoring functions, and ensures the efficiency of the heat exchanger 109 by regulating the temperature of cooling water.

[0034] In a preferred implementation, at least two concentration meters 111 are connected in parallel to the third infusion pipeline. The dual concentration meters 111 are designed to compare and verify the measured concentration values ​​to ensure that the concentration value of the diluted developer is accurate and reliable.

[0035] A developer dilution method, using the developer dilution system, specifically comprises the following steps:

[0036] S1: Calculating a first target weight of pure water and a second target weight of the developer stock solution according to a required developer dilution value, a developer stock solution concentration value, and a developer concentration value after dilution;

[0037] S2: The pure water supply pipeline 102 outputs pure water, which is regulated by the supply regulating module 103 and then input into the mixing storage tank 106. When the canned weighing device 107 determines that the weight of the pure water reaches the first target weight, the supply regulating module 103 shuts off the pure water supply;

[0038] S3: The developer stock solution is output from the stock solution supply pipeline 101, and after being adjusted by the supply adjustment module 103, it is input into the mixing storage tank 106. When the tank weighing device 107 determines that the developer stock solution has reached the second target weight, the supply adjustment module 103 closes the developer stock solution supply;

[0039] S4: Open the first valve 112, close the second valve 113, set the cycle time, and use the pneumatic pump 108 to extract the pure water and developer solution in the mixing tank 106, pass through the heat exchanger 109, and then input into the mixing tank 106 through the reflux pipe;

[0040] S5: After the set cycle time, the concentration of the diluted developer is detected and determined by the concentration meter 111;

[0041] S6: If the concentration of the diluted developer is qualified, the first valve 112 is closed, the second valve 113 is opened, the pneumatic pump 108 extracts the diluted developer in the mixing tank 106, and the nitrogen supply pipeline 104 inputs nitrogen into the mixing tank 106 via the humidification module, and the diluted developer is sent to the next process via the output pipeline. If the detected concentration of the diluted developer is too high, the third target weight of pure water to be added is calculated first, and the supply adjustment module 103 starts the pure water supply. When the canned weighing device 107 determines that the pure water weight reaches the third target weight, the supply adjustment module 103 closes the pure water supply. Water supply, and then jump to step S4 again. If the detected diluted developer concentration is low, the fourth target weight of the pure water to be added and the fifth target weight of the developer stock solution are calculated again. The supply adjustment module 103 first turns on the pure water supply. When the canned weighing device 107 determines that the pure water weight reaches the fourth target weight, the supply adjustment module 103 turns off the pure water supply and turns on the developer stock solution supply. When the canned weighing device 107 determines that the developer stock solution reaches the fifth target weight, the supply adjustment module 103 turns off the developer stock solution supply, and then jumps to step S4 again.

[0042] The developer dilution system of the present invention can dilute the developer stock solution in a wide concentration range and has high applicability. The maximum dilutable developer stock solution concentration range is 10%-80%. At the same time, the concentration range of the diluted developer can be stabilized within the required range of 2.38%±0.002%, with high precision and high stability.

[0043] The above is only a preferred embodiment of the present invention, and its description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that several improvements and modifications can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A developer dilution system, characterized in that: include: A mixing tank, wherein a raw liquid supply pipeline, a pure water supply pipeline and a nitrogen supply pipeline are sequentially arranged on the top of the mixing tank, a supply regulating module is provided on the raw liquid supply pipeline and the pure water supply pipeline, a humidifier module is provided on the nitrogen supply pipeline, and a canned weighing device is provided at the foot of the mixing tank; A pneumatic pump connected to the lower end of the mixing tank through a first liquid infusion pipeline; A heat exchanger, wherein the inlet end of the heat exchanger is connected to the pneumatic pump through a second infusion pipeline, the outlet end of the heat exchanger is connected to a third infusion pipeline, the end of the third infusion pipeline away from the heat exchanger is connected to a reflux pipeline and an output pipeline respectively through a three-way joint, the other end of the reflux pipeline is connected to the top of the mixing storage tank, the reflux pipeline is provided with a first valve, and the output pipeline is provided with a second valve.

2. The developer dilution system according to claim 1, characterized in that: The number of the pneumatic pumps is at least 2, and at least 2 of the pneumatic pumps are connected in parallel and commonly connected between the first infusion pipeline and the second infusion pipeline.

3. The developer dilution system according to claim 1, characterized in that: The system further comprises: A cooler is connected to the heat exchanger.

4. The developer dilution system according to claim 1, characterized in that: At least two concentration meters are connected in parallel to the third infusion pipeline.

5. A developer dilution method, using the developer dilution system according to any one of claims 1 to 4, characterized in that: The specific steps include: S1: Calculating a first target weight of pure water and a second target weight of the developer stock solution according to a required developer dilution value, a developer stock solution concentration value, and a developer concentration value after dilution; S2: The pure water supply pipeline outputs pure water, which is regulated by the supply regulating module and then input into the mixing tank. When the canned weighing device determines that the weight of the pure water reaches the first target weight, the supply regulating module shuts off the pure water supply; S3: The developer stock solution is output from the stock solution supply pipeline, and after being adjusted by the supply adjustment module, it is input into the mixing storage tank. When the tank weighing device determines that the developer stock solution has reached the second target weight, the supply adjustment module closes the developer stock solution supply; S4: Open the first valve, close the second valve, set the cycle time, and use the pneumatic pump to extract the pure water and developer solution in the mixing tank, pass through the heat exchanger, and then input into the mixing tank through the reflux pipe; S5: After the set cycle time, the concentration of the diluted developer is detected and determined by a concentration meter; S6: If the concentration of the diluted developer is qualified, the first valve is closed, the second valve is opened, and the pneumatic pump extracts the diluted developer in the mixing tank. At the same time, the nitrogen supply pipeline inputs nitrogen into the mixing tank through the humidification module, and the diluted developer is sent to the next process through the output pipeline. If the detected concentration of the diluted developer is high, the third target weight of pure water to be added is calculated first, and the supply adjustment module starts the pure water supply. When the canned weighing device determines that the weight of the pure water reaches the third target weight, the supply adjustment module turns off the pure water supply, and then jumps back to step S4. If the detected concentration of the diluted developer is low, the fourth target weight of the pure water to be added and the fifth target weight of the developer stock solution are calculated again. The supply adjustment module first turns on the pure water supply. When the canned weighing device determines that the weight of the pure water reaches the fourth target weight, the supply adjustment module turns off the pure water supply and turns on the developer stock solution supply. When the canned weighing device determines that the developer stock solution reaches the fifth target weight, the supply adjustment module turns off the developer stock solution supply, and then jumps back to step S4.

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