Drainage device and drainage method

Abstract

The application discloses a liquid discharging device and a liquid discharging method, and relates to the field of semiconductors, aiming at solving the problem of long liquid replacement time caused by long cooling time of high-temperature chemical liquid in a cleaning process. The liquid discharging device comprises a chemical liquid tank, a liquid discharging pipeline and a liquid discharging tank; the chemical liquid tank is communicated with the liquid discharging tank through the liquid discharging pipeline; the liquid discharging device further comprises a cooling pipeline arranged on the liquid discharging pipeline; the cooling pipeline is used for cooling the liquid discharging pipeline and the chemical liquid in the liquid discharging pipeline when the temperature of the chemical liquid in the liquid discharging pipeline is higher than a temperature threshold. The liquid discharging method comprises the technical scheme. The liquid discharging device and the liquid discharging method are used for quickly cooling and replacing high-temperature chemical liquid.

Description

Technical Field

[0001] This invention relates to the field of semiconductors, and more particularly to a draining device and a draining method. Background Technology

[0002] In the integrated circuit manufacturing process, cleaning is an integral part of the entire process flow, typically accounting for more than 20% of the total process steps. As critical dimensions continue to shrink, the control of contamination on the silicon wafer surface becomes more stringent, and in some processes, cleaning accounts for more than 40% of the total process steps. In many processes, cleaning equipment needs to use high-temperature chemical solutions to clean the wafers. These high-temperature chemical solutions have a fixed usage time, and they are frequently replaced when the usage time is reached, or to avoid cross-contamination between different batches, or if other chemical solutions are needed for cleaning.

[0003] In related technologies, to prevent high-temperature chemical solutions from damaging pipelines, the high-temperature chemical solution is discharged from the chemical solution tank to the drain tank. A large amount of cooling water, nitrogen gas, or natural cooling is required to cool the chemical solution in the drain tank. This means the high-temperature chemical solution needs to remain in the drain tank for a considerable time to cool below the preset temperature before finally being discharged. Traditional methods, due to their long cooling and draining times (generally exceeding 90 minutes), result in a prolonged chemical solution replacement time, thus affecting cleaning efficiency and production capacity. Summary of the Invention

[0004] The purpose of this invention is to provide a draining device and a draining method, so as to use the draining device to quickly cool down the high-temperature chemical liquid and shorten the draining time.

[0005] In a first aspect, the present invention provides a draining device, the draining device comprising: a chemical liquid tank, a draining pipe, and a draining trough; the chemical liquid tank is connected to the draining trough through the draining pipe; the draining device further comprises a cooling pipe provided on the draining pipe;

[0006] The cooling pipeline is used to cool the drain pipe and the chemical liquid inside the drain pipe when the temperature of the chemical liquid in the drain pipe is higher than the temperature threshold.

[0007] Compared with the prior art, in the drainage device provided by the present invention, the chemical liquid tank is connected to the drainage tank through a drainage pipe, and a cooling line is installed on the drainage pipe. Based on this, when the temperature of the chemical liquid in the drainage pipe is higher than the temperature threshold, the cooling line is turned on to cool down the drainage pipe, thereby rapidly cooling down the high-temperature chemical liquid in the drainage pipe, thus shortening the chemical liquid drainage time and increasing equipment capacity.

[0008] Secondly, the present invention also provides a drainage method, using the drainage device described in the above technical solution, the drainage method comprising:

[0009] To obtain the temperature of the chemical solution in the drainage pipe;

[0010] When the temperature of the chemical liquid in the drain pipe is higher than the temperature threshold, the cooling pipeline is controlled to cool down the drain pipe and the chemical liquid in the drain pipe.

[0011] Compared with the prior art, the beneficial effects of the drainage method provided by the present invention are the same as those of the drainage device described above, and will not be repeated here. Attached Figure Description

[0012] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0013] Figure 1 This is a schematic diagram of the semiconductor cleaning process in related technologies;

[0014] Figure 2 A schematic diagram of the drainage device provided in an embodiment of the present invention;

[0015] Figure 3 A schematic diagram of a cooling pipeline installed on a drain pipe according to an embodiment of the present invention;

[0016] Figure 4 This is a schematic diagram of the connection of the drainage pipe provided in an embodiment of the present invention;

[0017] Figure 5 This is a schematic flowchart of a drainage method provided in an embodiment of the present invention. Detailed Implementation

[0018] To facilitate a clear description of the technical solutions in the embodiments of the present invention, the terms "first" and "second" are used to distinguish identical or similar items with essentially the same function and effect. For example, the first threshold and the second threshold are merely used to distinguish different thresholds and do not limit their order. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and that the terms "first" and "second" are not necessarily different.

[0019] It should be noted that in this invention, the terms "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in this invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0020] In this invention, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, a combination of a and b, a combination of a and c, a combination of b and c, or a, b, and c, where a, b, and c can be single or multiple.

[0021] Figure 1 Example: A schematic diagram of the semiconductor cleaning process in related technologies, such as... Figure 1 As shown, the entire process involves numerous cleaning steps. Cleaning machines are generally divided into single-wafer cleaning or tank cleaning, i.e., multi-wafer cleaning. Specifically, the cleaning steps include: First, the wafers are loaded into the cleaning machine and then placed in a buffer zone, where different batches of wafers queue up for cleaning. When a batch of wafers needs cleaning, it is placed in diluted hydrofluoric acid. After cleaning, the wafers are placed in a rapid drainage device for rinsing after the hydrofluoric acid treatment. After rinsing, the wafers are placed in a chemical solution tank for cleaning. The number of chemical solution tanks depends on the process; two tanks are shown here, but it is not limited to two. After being removed from the chemical solution tank, the wafers are placed in a rinsing tank for rinsing after chemical cleaning. The next step is to soak and rinse the wafers in water before drying, then dry them with isopropanol. The final step is to remove the wafers and discharge them. In practical applications, the cleaning process shown in this diagram is not limited to this specific step.

[0022] In related technologies, the high-temperature chemical solution in the chemical solution tank needs to be frequently replaced before cleaning. After the high-temperature chemical solution is discharged from the chemical solution tank into the drain tank, a large amount of cooling water, nitrogen gas, or natural cooling is injected into the drain tank to cool the chemical solution before it is discharged. The high-temperature chemical solution needs to wait in the drain tank for a relatively long time to cool down to below the preset temperature, generally below 50 degrees Celsius. This makes the entire chemical solution replacement process time-consuming, with current methods taking more than 90 minutes.

[0023] To address the aforementioned problems, embodiments of the present invention provide a draining device applicable to the wet etching field used in the manufacture of semiconductor devices, dynamic random access memory, phase change memory, magnetic random access memory, etc.

[0024] Figure 2A schematic diagram of the drainage device provided in an embodiment of the present invention is shown. Figure 2 As shown, the draining device provided in this embodiment of the invention includes: a chemical liquid tank 101, a drain pipe 103, and a drain trough 102; the chemical liquid tank 101 is connected to the drain trough 102 through the drain pipe 103; the draining device also includes a cooling line 104 provided on the drain pipe 103; the cooling line 104 is used to cool the drain pipe 103 and the chemical liquid in the drain pipe when the temperature of the chemical liquid in the drain pipe 103 is higher than the temperature threshold.

[0025] In practical applications, the drain pipe can be made of polytetrafluoroethylene (PTFE), an acid and alkali resistant material that can prevent corrosion by chemical liquids. The cooling lines can be made of stainless steel, but the materials of the drain pipe and cooling lines are not limited to these. The chemical liquid includes at least one of phosphoric acid, sulfuric acid, or a mixture of sulfuric acid and hydrogen peroxide at room temperature or above a second preset temperature.

[0026] A cooling line is installed outside the drain pipe between the chemical liquid tank and the drain tank to determine whether the temperature of the chemical liquid in the drain pipe is higher than a temperature threshold. If the temperature of the chemical liquid in the drain pipe is lower than or equal to the temperature threshold, the cooling line does not operate and does not cool the drain pipe. If the temperature of the chemical liquid in the drain pipe is higher than the temperature threshold, the cooling line is controlled to cool the drain pipe, which indirectly cools the high-temperature chemical liquid passing through the drain pipe.

[0027] As those skilled in the art know, cooling lines are typically filled with refrigerant to keep their temperature low. The refrigerant can be cooling water or a fluorinated refrigerant, etc. Figure 3 An example is a schematic diagram of the structure of the cooling pipeline provided in the embodiment of the present invention being installed on the drain pipe, such as... Figure 3 As shown, the controller adjusts the pressure control device 1041 to supply an appropriate amount of refrigerant gas into the cooling pipeline 104 according to the temperature of the chemical liquid. For example, the refrigerant gas pressure range is 2 kg / cm². 2 -3kg / cm 2 Cooling pipe 104 is wrapped around drain pipe 103. A suitable amount of refrigerant gas lowers the temperature of cooling pipe 104. Through heat conduction, the working cooling pipe 104 cools drain pipe 103. The refrigerant gas in cooling pipe 104 is heated by heat conduction and finally discharged from the other end.

[0028] Of course, the aforementioned cooling lines can also be used to cool the drain pipes when the temperature of the chemical solution in the drain tank is higher than the temperature threshold. This can be understood as follows: when either the temperature of the chemical solution in the drain pipes or the temperature of the chemical solution in the drain tank exceeds the temperature threshold, the cooling lines will activate to cool the drain pipes. For example, if the temperature of the chemical solution in the drain pipes is lower than the temperature threshold, but the temperature of the chemical solution in the drain tank is higher than the temperature threshold, the cooling lines will cool the drain pipes and the chemical solution within them.

[0029] To achieve intelligent drainage, the drainage device also includes a controller, which controls the cooling pipeline to cool the drainage pipe when the temperature of the chemical liquid discharged from the drainage pipe is higher than the temperature threshold; the drainage pipe also includes a first temperature sensor, which is used to detect the temperature of the chemical liquid in the drainage pipe.

[0030] The controller is also used to control the cooling lines to cool the drain pipe when the temperature of the chemical liquid in the drain tank is higher than a temperature threshold. The drain tank also includes a second temperature sensor for detecting the temperature of the chemical liquid in the drain tank. To obtain the temperature of the chemical liquid in the drain pipe or the drain tank, a first temperature sensor or a second temperature sensor needs to be installed in the drain pipe or the drain tank.

[0031] In practical applications, the temperature of the chemical solution is used to determine when the cooling pipeline should start operating. This determination requires a controller. If the temperature of the chemical solution in the drain pipe exceeds a temperature threshold, the cooling pipeline is activated. For example, the temperature of a high-temperature chemical solution might range from 70 to 163 degrees Celsius. If the temperature threshold is 70 degrees Celsius, when the chemical solution temperature exceeds 70 degrees Celsius, the controller will activate the cooling pipeline to cool the high-temperature chemical solution, maintaining its temperature between 25 and 50 degrees Celsius. Simultaneously, the controller also controls the pressure device of the cooling pipeline based on the chemical solution temperature, controlling the pressure and quantity of refrigerant gas supplied to the cooling pipeline to maintain its temperature within a specific range, thereby cooling the drain pipe.

[0032] To enable intelligent control of the drainage tank, the aforementioned drainage tank also includes a level sensor. The level sensor detects the height of the chemical liquid within the drainage tank. The controller further controls the drainage of the chemical liquid when the height of the chemical liquid in the drainage tank exceeds a preset drainage level threshold, or when the temperature of the chemical liquid in the drainage tank falls below a temperature threshold.

[0033] In practical applications, the temperature of the chemical solution can be used to control the cooling of the drain pipe, reducing the time for replacing high-temperature chemical solutions to less than 20 minutes. However, the discharge of the cooled chemical solution requires consideration of two factors: whether the cooled chemical solution is below the temperature threshold and whether the liquid level is above the preset drain level threshold. When both conditions are met, the cooled chemical solution in the drain tank is discharged. For example, in one scenario, the chemical solution in the drain tank may be empty, but although the temperature meets the requirements, there is no need for further discharge; in this case, discharge is stopped.

[0034] In one example, the aforementioned drainage pipes include a first drainage pipe, a second drainage pipe, a third drainage pipe, and a fourth drainage pipe; cooling lines are installed on the first drainage pipe, the second drainage pipe, the third drainage pipe, and the fourth drainage pipe.

[0035] The aforementioned drainage device also includes a filter, a heater, and a pump. The chemical liquid tank is connected to the inlet of the filter via a first drainage pipe, the first outlet of the filter is connected to the drainage tank via a second drainage pipe, the second outlet of the filter is connected to the heater via a third drainage pipe, and the heater is also connected to the pump via a fourth drainage pipe; the pump is connected to the chemical liquid tank and also to the drainage tank.

[0036] Figure 4 A schematic diagram of the connection of the drainage pipe provided in an embodiment of the present invention is shown. Figure 4 As shown, the chemical liquid tank 101 can be divided into an inner tank and an outer tank according to different process requirements. The discharge of chemical liquid from the inner tank is mainly divided into two paths. The first path is that the inner tank is connected to the inlet of the filter 105, the first outlet of the filter 105 is connected to the heater 106, the heater 105 is then connected to the first valve A, and the first valve A is then connected to the valve D. The second path is that the second outlet of the filter 105 is connected to the second valve B, and finally connected to the valve D.

[0037] like Figure 4 As shown, the chemical liquid in the outer tank is discharged via a third route. The outer tank is connected to pump 107 via a third valve C, and pump 107 is then connected to valve D. The first and second pipes share a filter 105. Valve D is connected to drain tank 102 for discharging the chemical liquid from the drain pipe. Heater 106 is also connected to pump 107; pump 107 is connected to the chemical liquid tank and also to drain tank 102.

[0038] like Figure 4As shown, when the chemical solution in the chemical solution tank is higher than the temperature threshold, the chemical solution passes through the first filter 105. The filter 105 will filter out some impurities, particles, insoluble substances, etc. in the chemical solution. The filtered substances may be washed off, or they may be particulate pollutants from humans or the environment that have fallen into the chemical solution tank and have been washed off. Because they are suspended in the chemical solution, they may be re-adsorbed onto other wafers or affect the cleaning effect of the next batch of wafers. Therefore, the filter 105 is needed to keep the chemical solution clean at all times. After being filtered by filter 105, the chemical liquid reaches heater 106. In the drain state, heater 106 is not heated, allowing the filtered chemical liquid to flow directly into drain tank 102. If the chemical liquid tank is not drained during normal process, but the chemical liquid in chemical liquid tank 101 is heated to the specified process temperature and then returned to chemical liquid tank 101 for cleaning, heater 106 will work, and cooling pipeline will not work. The first line heater 106 is connected to the third line pump 107. The heated chemical liquid is pumped up by pump 107 and enters the inner tank of chemical liquid through the fourth valve E.

[0039] like Figure 4 As shown, the second path is for the chemical liquid in filter 105 to directly enter the drain tank 102. This is an independent drain line for filter 105. There will always be some chemical liquid remaining in filter 105. Discharging it together with the chemical liquid in chemical liquid tank 101 often results in incomplete discharge. Therefore, it is necessary to add an independent drain line. Figure 4 In the diagram, valves B and D are white, indicating they are open, thus controlling the second drainage path. Other paths cannot drain. The opening and closing states of valves in other paths can be determined similarly. The third path involves direct discharge from the outer tank to the drainage tank 102 via pump 107. Level sensor 108 and temperature sensor 109 are located within the drainage tank 102. Depending on the cleaning process, only one or both of the inner and outer tanks may be used. The drainage pipe connection structure in this embodiment is merely for illustrating the drainage process; in practical applications, the connection structure or components of the drainage pipe are not limited to this.

[0040] The drainage device provided by this invention includes a chemical liquid tank, a drainage pipe, and a drainage channel. The chemical liquid tank is connected to the drainage channel via the drainage pipe. This invention utilizes a cooling line installed on the drainage pipe. When the temperature of the chemical liquid in the drainage pipe exceeds a temperature threshold, the cooling line is activated to cool the drainage pipe. Those skilled in the art know that the temperature of the cooling line can be lowered by adding refrigerant or other methods. The drainage device provided by this invention, by controlling the cooling line to rapidly cool the high-temperature chemical liquid, shortens the chemical liquid drainage time, thereby increasing equipment productivity.

[0041] Based on the above-mentioned drainage device Figure 5 A schematic flowchart of a drainage method provided by an embodiment of the present invention is shown. The drainage method includes the following steps:

[0042] Step 101: Obtain the temperature of the chemical liquid in the drain pipe using the first temperature sensor;

[0043] Step 102: When the temperature of the chemical liquid in the drain pipe is higher than the temperature threshold, the controller controls the cooling line to cool down the drain pipe.

[0044] As one feasible approach, drainage methods also include:

[0045] The temperature of the chemical liquid in the drain tank is obtained by a second temperature sensor;

[0046] When the temperature of the chemical liquid in the drain tank exceeds the temperature threshold, the controller controls the cooling pipeline to cool down the drain pipe.

[0047] In one alternative approach, after the controller controls the cooling pipeline to cool the drain pipe, the draining method further includes: obtaining the liquid level of the chemical liquid in the drain tank through a liquid level sensor; when the height of the chemical liquid in the drain tank is higher than a preset drain liquid level threshold and the temperature of the chemical liquid in the drain tank is lower than a temperature threshold, the controller controls the chemical liquid in the drain tank to be discharged.

[0048] Although the invention has been described herein in conjunction with various embodiments, those skilled in the art will understand and implement other variations of the disclosed embodiments by reviewing the accompanying drawings, the disclosure, and the appended claims in carrying out the claimed invention. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude a plurality. A single processor or other unit can implement several functions listed in the claims. While different dependent claims may recite certain measures, this does not mean that these measures cannot be combined to produce good results.

[0049] Although the invention has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made therein without departing from the spirit and scope of the invention. Accordingly, this specification and drawings are merely exemplary descriptions of the invention as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of the invention. Clearly, those skilled in the art can make various alterations and modifications to the invention without departing from its spirit and scope. Thus, if such modifications and modifications of the invention fall within the scope of the claims and their equivalents, the invention is also intended to include such modifications and modifications.

Claims

1. A draining device, characterized in that, The drainage device includes: a chemical liquid tank, a drainage pipe, and a drainage trough; the chemical liquid tank is connected to the drainage trough through the drainage pipe; the drainage device also includes a cooling pipe installed on the drainage pipe; The cooling pipeline is used to cool the drain pipe and the chemical liquid inside the drain pipe when the temperature of the chemical liquid in the drain pipe is higher than the temperature threshold. The cooling pipeline is also used to cool the drainage pipe and the chemical liquid in the drainage pipe when the temperature of the chemical liquid in the drainage tank is higher than the temperature threshold. The drainage pipeline includes a first drainage pipe, a second drainage pipe, a third drainage pipe, and a fourth drainage pipe; cooling pipelines are installed on the first drainage pipe, the second drainage pipe, the third drainage pipe, and the fourth drainage pipe; The drainage device further includes: a filter, a heater, and a pump; the chemical liquid tank is connected to the inlet of the filter through a first drainage pipe, the first outlet of the filter is connected to the drainage tank through a second drainage pipe, the second outlet of the filter is connected to the heater through a third drainage pipe, and the heater is also connected to the pump through a fourth drainage pipe; the pump is connected to the chemical liquid tank and also connected to the drainage tank; The chemical liquid tank is divided into an inner tank and an outer tank. The discharge of the chemical liquid from the inner tank is divided into two paths. The first path is that the inner tank is connected to the inlet of the filter, the first outlet of the filter is connected to the heater, the heater is then connected to the first valve, and the first valve is then connected to the inlet valve of the drain tank. The second path is that the second outlet of the filter is connected to the second valve, and the second valve is connected to the inlet valve of the drain tank. The chemical liquid in the outer tank is discharged via a third channel. The outer tank is connected to the pump via a third valve, and the pump is then connected to the inlet valve of the drain tank. The first and second channels share a filter. The inlet valve of the drain tank is connected to the drain tank and is used to discharge the chemical liquid from the drain pipe.

2. The drainage device according to claim 1, characterized in that, The draining device also includes a controller, which is used to control the cooling pipeline to cool the draining pipeline and the chemical liquid inside the draining pipeline when the temperature of the chemical liquid discharged from the draining pipeline is higher than the temperature threshold. The drain pipe also includes a first temperature sensor, which is used to detect the temperature of the chemical liquid in the drain pipe.

3. The drainage device according to claim 2, characterized in that, The controller is also used to control the cooling pipeline to cool the drainage pipe and the chemical liquid in the drainage pipe when the temperature of the chemical liquid in the drainage tank is higher than the temperature threshold. The drain tank also includes a second temperature sensor, which is used to detect the temperature of the chemical liquid in the drain tank.

4. The draining device according to claim 3, characterized in that, The drain tank also includes a level sensor, which is used to detect the height of the chemical liquid in the drain tank; the controller is also used to control the discharge of the chemical liquid in the drain tank when the height of the chemical liquid in the drain tank is higher than a preset drain level threshold and the temperature of the chemical liquid in the drain tank is lower than a temperature threshold.

5. A method for draining fluid, characterized in that, Using the draining device according to any one of claims 1 to 4, the draining method comprises: To obtain the temperature of the chemical solution in the drainage pipe; When the temperature of the chemical liquid in the drain pipe is higher than the temperature threshold, the cooling pipeline is controlled to cool down the drain pipe.

6. The drainage method according to claim 5, characterized in that, The drainage method further includes: To obtain the temperature of the chemical solution in the drainage tank; When the temperature of the chemical liquid in the drain tank exceeds a temperature threshold, the cooling pipeline is controlled to cool the drain pipe and the chemical liquid within it. The cooled chemical liquid is then kept between 25°C and 50°C, and the refrigerant gas pressure in the cooling pipeline is 2 kg / cm³. 2 -3kg / cm 2 .

7. The drainage method according to claim 6, characterized in that, After controlling the cooling pipeline to cool the drain pipe, the draining method further includes: obtaining the liquid level of the chemical liquid in the drain tank; when the height of the chemical liquid in the drain tank is higher than a preset drain liquid level threshold and the temperature of the chemical liquid in the drain tank is lower than a temperature threshold, controlling the chemical liquid in the drain tank to be discharged.

8. The drainage method according to claim 5, characterized in that, The chemical liquid includes: At least one of phosphoric acid, sulfuric acid, or sulfuric acid-hydrogen peroxide mixture at room temperature or above a second preset temperature.

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