Quantitative acid make-up system for a chemical

Abstract

The utility model relates to the technical field of semiconductor, especially relate to a kind of quantitative acid supplement system of chemical. Including a scale, a certain amount of bucket, a liquid outlet, a reaction tank, certain amount of bucket is connected with the acid supply pipeline between reaction tank. In the patent, keep the ascending section pipeline of acid supply pipeline full of chemical before acid supplement, and close valve, the amount of chemical required by reaction tank is accurately supplied into certain amount of bucket by chemical acid supply system and scale cooperation, open valve when acid supply, nitrogen pressure is used to send the chemical in certain amount of bucket into reaction tank, immediately close valve when scale monitors that weight change reaches the amount of chemical required by reaction tank. And the ascending section pipeline of acid supply pipeline is lifted, so that the pressure required for chemical discharge in acid supply pipeline is improved, thereby improving the stability of chemical movement in acid supply pipeline during acid supply, reducing the amount of chemical flushing out of acid supply pipeline in the last stage of acid supply;Meanwhile, also avoid part of chemical remaining in gentle acid supply pipeline, reach the purpose of accurate acid supplement.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor technology, and in particular to a quantitative acid replenishment system for chemicals. Background Technology

[0002] In semiconductor manufacturing processes using semiconductor chemical wet process equipment, precise acid replenishment is involved, which directly affects the concentration ratio of chemicals and thus the stability of the semiconductor wafer manufacturing process.

[0003] During quantitative acid supply, chemicals (acid) are supplied to a quantitative tank via a chemical acid supply system. A weighing mechanism is installed below the quantitative tank to confirm the weight of the supplied acid. After completion, the chemicals in the quantitative tank are supplied to the designated process reaction tank through the acid supply pipeline via nitrogen pressure to achieve mixed acid.

[0004] In actual acid supply processes, the specific gravity of each chemical liquid differs, and the nitrogen pressure method and liquid level inside the metering tank all affect the movement speed of the chemicals within the acid supply pipeline. Therefore, even if acid supply is stopped immediately at the same time, the amount of chemicals ultimately flowing into the reaction tank from the end of the supply pipeline will vary due to gravity and inertia, making precise control of the addition amount impossible. Furthermore, because there is a certain distance between the metering tank and the process reaction tank—that is, the acid supply pipeline has a certain length—some chemicals will remain in the relatively flat supply pipeline during acid supply, also affecting the accuracy of acid replenishment. Utility Model Content

[0005] The technical problem to be solved by this invention is to provide a quantitative acid replenishment system for chemicals with high precision in acid replenishment.

[0006] To solve the above-mentioned technical problems, the technical solution of this utility model is: a quantitative acid replenishment system for chemicals, the innovation of which lies in: including A metering container for temporary storage of chemicals, wherein the inner bottom wall of the metering container is an inclined surface, the lower side of the inclined surface is the discharge side, and the discharge side is provided with a liquid outlet, and the liquid outlet is provided with a liquid outlet connector. An electronic scale for real-time weighing of a metering bin, wherein the electronic scale is positioned below the metering bin; A reaction tank, wherein a liquid inlet is provided at the top of the reaction tank; An acid supply pipeline for connecting a metering tank and a reaction vessel, the acid supply pipeline including an ascending section pipeline and a descending section pipeline, the ascending section pipeline having a low-level inlet and a high-level outlet, the descending section pipeline having a high-level inlet and a low-level outlet, the low-level inlet of the ascending section pipeline being connected to a liquid outlet connector, the high-level inlet of the descending section pipeline being directly connected to the high-level outlet of the ascending section pipeline, and the low-level outlet of the descending section pipeline being connected to the liquid inlet of the reaction vessel; and the connection point between the ascending section pipeline and the descending section pipeline is located at the highest point of the acid supply pipeline; A valve is provided on the liquid outlet connector, and the liquid outlet connector is flexibly connected to the low-level inlet of the rising section pipeline. The chemicals in the metering tank are introduced into the reaction tank through the acid supply pipeline by nitrogen pressure to replenish the acid. Before replenishing the acid, the rising section pipeline of the metering acid replenishment system is filled with chemicals.

[0007] Furthermore, the electronic scale is equipped with an acid and alkali resistant plastic sealing layer on its outer side, and clean air is injected between the sealing layer and the scale to prevent acid gas from corroding the scale.

[0008] Furthermore, the metering container is equipped with a level tube and a level sensor, and the accuracy is ensured through the dual confirmation of the level tube and the level sensor.

[0009] Furthermore, the top of the metering container is also provided with a liquid inlet and an air inlet.

[0010] Furthermore, the descending section of the pipe is set almost vertically, and the angle between the axis of the descending section and the vertical direction is within ±5°, which can significantly reduce the risk of acid adhering to the wall inside the descending section.

[0011] Furthermore, the nitrogen pressure rate is preferably between 500-1000 cc / min. Furthermore, the rising section of the pipeline is inclined upwards from the low-level inlet to the high-level outlet.

[0012] Furthermore, the rising section of the pipeline is a vertical section near the high-level outlet, and the high-level outlet is located at the top of the vertical section.

[0013] Furthermore, the liquid outlet connector is flexibly connected to the low-position inlet of the rising section pipe, allowing the acid supply pipe to sag naturally during weighing, thus avoiding rigid transmission of external force.

[0014] The advantages of this utility model are: In this patent, the rising section of the acid supply pipeline is kept full of chemicals before acid replenishment, and the valve is closed. The required amount of chemicals for the reaction tank is accurately supplied to the metering container by the chemical acid supply system in conjunction with a weighing scale. During acid supply, the valve is opened, and the chemicals in the metering container are sent into the reaction tank through nitrogen pressure. During this process, the weighing scale monitors the overall weight of the metering container in real time. When the weighing scale detects that the weight change has reached the required amount of chemicals for the reaction tank, the valve is immediately closed. By utilizing the design of the rising and falling sections of the acid supply pipeline, the pressure required for the chemicals to be discharged from the acid supply pipeline is increased after the rising section of the acid supply pipeline is raised. This improves the stability of the movement of chemicals in the acid supply pipeline during acid supply and reduces the amount of chemicals flushed out of the acid supply pipeline in the final stage of acid supply. At the same time, it also avoids some chemicals remaining in the flat acid supply pipeline, which would affect the acid replenishment accuracy. Ultimately, it achieves the goal of precise acid replenishment, with the precise acid replenishment amount within a 1% error value.

[0015] 2. The bottom wall of the metering tank is an inclined surface, and the lower side of the inclined surface is the discharge side, ensuring that there will be no residue problem when discharging acid.

[0016] 3. The metering tank is equipped with a level tube and a level sensor. The accuracy is improved through the dual confirmation of the level tube and the level sensor.

[0017] 4. The angle between the axis of the descending section of the pipeline and the vertical direction is within ±5°, which can significantly reduce the risk of acid adhering to the inside of the descending section of the pipeline.

[0018] 5. The optimal nitrogen pressure rate is 500-1000 cc / min, balancing the stability and efficiency of chemical flow, ensuring uniform delivery, and preventing chemicals from rushing into the reaction tank when the valve is closed, thus affecting the accuracy of acid supply, should the flow rate be too high. 6. The flexible connection between the liquid outlet connector and the low inlet of the rising section pipeline avoids the need to calculate the weight of chemicals in the acid supply pipeline when weighing with a scale. The amount of chemicals entering the reaction tank can be determined directly from the weight of chemicals in the metering tank, making the calculation more convenient. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of one embodiment of the present invention before weighing.

[0020] Figure 2 This is a schematic diagram of one embodiment of the present invention after weighing and before acid supply.

[0021] Figure 3 This is a schematic diagram of the state of one embodiment of the present invention after acid supply.

[0022] Figure 4 This is a schematic diagram of another embodiment of the present invention after acid supply. Detailed Implementation

[0023] To further illustrate the technical means and effects adopted by this utility model in order to achieve the intended utility model purpose, the following detailed description of the specific implementation methods, structure, features and effects of this utility model is provided in conjunction with the accompanying drawings and preferred embodiments.

[0024] like Figures 1-4 The illustrated chemical quantitative acid replenishment system includes an electronic scale 1, a measuring tank 2, a reaction tank 4, and an acid supply pipeline 8.

[0025] Electronic scale 1 is used to weigh quantitative container 2 in real time. Electronic scale 1 is horizontally set below quantitative container 2.

[0026] The metering container 2 is used for temporary storage of chemicals. It is horizontally and tightly installed at the center of the top surface of the electronic scale 1. The entire outer side of the electronic scale 1 is equipped with an acid and alkali resistant plastic sealing layer, and clean air is injected between the sealing layer and the electronic scale 1 to prevent acid gas from corroding the electronic scale 1.

[0027] Since the electronic scale 1 is located at the bottom of the metering container 2, and considering the issue of accuracy, it cannot be affected by the vibration of the metering container 2. Therefore, the entire bottom surface of the outer side of the metering container 2 is in close contact with the electronic scale 1.

[0028] The metering tank 2 includes a tank body 21, the bottom of which is an inclined surface 22. The lower side of the inclined surface 22 is the discharge side to ensure that there is no residue problem when discharging acid.

[0029] A liquid outlet 3 is provided on the bottom side of the metering tank 2, on the discharge side of the inclined surface 22. A liquid outlet connector is provided at the liquid outlet 3. A liquid inlet and an air inlet are provided at the top of the metering tank 2. The air inlet is connected to a nitrogen compressor, and the liquid inlet is connected to a chemical acid supply system. The chemical acid supply system delivers chemicals into each metering tank.

[0030] The metering tank 2 is also equipped with a level tube and a level sensor. The accuracy is ensured through the dual confirmation of the level tube and the level sensor.

[0031] The top of the reaction tank 4 is equipped with a liquid inlet.

[0032] The acid supply pipeline 8 is used to connect the metering tank 2 and the reaction tank 4. The acid supply pipeline 8 includes an ascending section pipeline 81 and a descending section pipeline 82.

[0033] The ascending section pipe 81 has a low-level inlet and a high-level outlet, while the descending section pipe 82 has a high-level inlet and a low-level outlet. The low-level inlet of the ascending section pipe 81 is connected to the liquid outlet connector, and the high-level inlet of the descending section pipe 82 is directly connected to the high-level outlet of the ascending section pipe 81. The low-level outlet of the descending section pipe 82 is connected to the liquid inlet of the reaction tank 4. Furthermore, the connection point between the ascending section pipe 81 and the descending section pipe 82 is located at the highest point of the acid supply pipe 8.

[0034] like Figure 3 As shown, the rising section pipe 81 is inclined upwards from the low-level inlet to the high-level outlet. This allows the chemical liquid filling the rising section pipe 81 to remain inside the rising section pipe 81, reducing chemical residue in the acid supply pipe 8. This enables precise acid replenishment inside the reaction tank, controlling the replenishment amount precisely within a 1% error value, thereby improving the subsequent chemical reaction effect. The descending section pipe 82 is set almost vertically, with the angle between the axis of the descending section pipe 82 and the vertical direction within ±5°, which significantly reduces the risk of acid adhering to the walls inside the descending section pipe 82.

[0035] Figure 4 Another embodiment of the acid supply pipeline is shown, in which the rising section of the pipeline 81 is a vertical section near the high-level outlet, with the high-level outlet located at the top of the vertical section. The high-level outlet of the rising section of the pipeline 81 is also connected to the high-level inlet of the descending section of the pipeline 82 by an upwardly convex arc-shaped pipeline.

[0036] A valve 9, which is either a solenoid valve or a pneumatic valve, is also installed on the liquid outlet connector. To facilitate the weighing calculation of chemicals in the metering container, a flexible connection is used between the liquid outlet connector and the low inlet of the rising section pipe 81. For example, flexible materials such as corrosion-resistant hoses or corrugated pipes are used to connect the acid supply pipe and the liquid outlet connector, allowing the acid supply pipe to hang naturally during weighing, avoiding rigid transmission of external force. Of course, those skilled in the art should understand that a suspension design can also be used, with the acid supply pipe suspended by hangers or springs so that its weight does not directly act on the scale. This will not be elaborated here.

[0037] The chemicals in metering tank 2 are introduced into the reaction tank via acid supply pipe 8 under nitrogen pressure to replenish the acid. Before acid replenishment, the rising section pipe 81 of the metering acid replenishment system is filled with chemicals. This patented technology is particularly applicable to the process tanks of semiconductor chemical wet process equipment, as well as the production of high-end electroplating solutions in chemical plants, ensuring chemical concentration and a good chemical reaction mechanism through precise acid replenishment. In this invention, the nitrogen pressure rate is preferably 500-1000cc / min. When applied to the acid supply tank of a semiconductor chemical wet process equipment, it takes into account both the stability and efficiency of chemical flow, and ensures uniform delivery, avoiding the chemical rushing into the reaction tank when the valve is closed due to excessive speed, which would affect the acid supply accuracy.

[0038] The working principle of this patent: Before adding acid, the rising section 81 of the acid supply pipeline 8 is filled with chemicals and the valve 9 is closed; Based on the amount of chemicals required for reaction tank 4, the chemical acid supply system first supplies chemicals to metering tank 2. Then, valve 9 is opened, and the chemicals inside metering tank 2 are sent into reaction tank 4 for precise acid mixing via nitrogen pressure. During this process, the scale monitors the overall weight of metering tank 2 in real time. When the scale detects a decrease in weight that reaches the amount of chemicals required for reaction tank 4, valve 9 is immediately closed. At this time, the rising section of the acid supply pipeline 81 is still basically full of chemicals. When applied to the acid supply of the semiconductor chemical wet process equipment, the acid replenishment amount is precisely controlled within an error value of about 1%.

[0039] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A chemical dosing acid make-up system characterised in that: include A metering container for temporary storage of chemicals, wherein the inner bottom wall of the metering container is an inclined surface, the lower side of the inclined surface is the discharge side, and the discharge side is provided with a liquid outlet, and the liquid outlet is provided with a liquid outlet connector. An electronic scale for real-time weighing of a metering bin, wherein the electronic scale is positioned below the metering bin; A reaction tank, wherein a liquid inlet is provided at the top of the reaction tank; An acid supply pipeline for connecting a metering tank and a reaction vessel, the acid supply pipeline including an ascending section pipeline and a descending section pipeline, the ascending section pipeline having a low-level inlet and a high-level outlet, the descending section pipeline having a high-level inlet and a low-level outlet, the low-level inlet of the ascending section pipeline being connected to a liquid outlet connector, the high-level inlet of the descending section pipeline being directly connected to the high-level outlet of the ascending section pipeline, and the low-level outlet of the descending section pipeline being connected to the liquid inlet of the reaction vessel; and the connection point between the ascending section pipeline and the descending section pipeline is located at the highest point of the acid supply pipeline; A valve, wherein the valve is installed on the liquid outlet connector; The chemicals in the metering tank are introduced into the reaction tank through the acid supply pipeline by nitrogen pressure to replenish the acid. Before replenishing the acid, the rising section pipeline of the metering acid replenishment system is filled with chemicals.

2. A chemical make-up acid system according to claim 1, characterized in that: The electronic scale has an acid and alkali resistant plastic sealing layer on its outer side.

3. The quantitative acid replenishment system for a chemical according to claim 1, characterized in that: The metering container is equipped with a level tube and a level sensor.

4. The chemical dosing system of claim 1, wherein: The top of the metering container is also equipped with a liquid inlet and an air inlet.

5. The chemical dosing acid supplement system according to claim 1, wherein: The descending section of the pipe is set almost vertically, and the angle between the axis of the descending section of the pipe and the vertical direction is within ±5°.

6. The chemical make-up acid system of claim 1, wherein: The nitrogen pressure rate is preferably 500-1000 cc / min.

7. The chemical make-up acid system of claim 1, wherein: The rising section of the pipeline is inclined upwards from the low-level inlet to the high-level outlet.

8. The chemical make-up acid system of claim 1, wherein: The rising section of the pipeline is a vertical section near the high-level outlet, and the high-level outlet is located at the top of the vertical section.

9. The chemical make-up acid system of claim 1, wherein: The liquid outlet connector is flexibly connected to the low-level inlet of the rising section pipeline.

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