Cleaning equipment and cleaning method for polytetrafluoroethylene filter element of semiconductor

Abstract

The invention relates to the technical field of semiconductors. The invention relates to cleaning equipment and a cleaning method for a polytetrafluoroethylene filter element of a semiconductor, which are characterized by comprising the following steps of: 1, soaking the polytetrafluoroethylene filter element to be cleaned in a proper amount of isopropanol to wet the polytetrafluoroethylene filter element; 2, soaking the polytetrafluoroethylene filter element in a proper amount of ultrapure water solution; 3, after the polytetrafluoroethylene filter element is arranged in a circulating system, adding a proper amount of hydrochloric acid aqueous solution into the circulating system for long-time circulating washing; 4, after acid liquor is discharged, pure water is added into the circulating system for long-time circulating washing; and fifthly, washing and wet packaging are conducted in a clean room, and cleaning is completed. According to the invention, an acid circulation system is established to circularly clean the filter element for a long time, so that the initial and long-term cleanliness of the filter element is ensured. The actual production requirement of the polytetrafluoroethylene filter element can be better met, and metal precipitation in the using process is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductors, and in particular to a cleaning device and a cleaning method for a polytetrafluoroethylene filter element used in semiconductors. Background Art

[0002] Semiconductor devices, especially high-density integrated circuits, are susceptible to damage from various types of contamination. In order to reduce yield losses due to contamination, semiconductor manufacturers have imposed strict purity requirements on equipment manufacturers. As the complexity of devices increases and the feature size decreases, the requirements for micro-contamination become higher. The main contaminants of semiconductor equipment during the microcircuit production process: particles, metals, and organic matter. Contaminants from the filter element in the liquid transfer system will eventually reach the processing environment in the form of solid particles or in the form of ion contamination through chemical reactions. Therefore, the filter element in the liquid transfer system must ensure its cleanliness before it is used in the production equipment.

[0003] During the production and processing of the filter element in the liquid transmission system, there will be particles, metals and organic matter residues. The current method is as follows: the first step is to soak it in an organic solvent, followed by soaking it in pure water; the second step is to soak it in an acid solution for a long time; the third step is to use pure water for physical flushing. However, the above methods cannot completely remove the particles and metals remaining in the filter element, and cannot meet the actual production and manufacturing needs. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a cleaning device and a cleaning method for a polytetrafluoroethylene filter element for semiconductors, which solves at least one of the above-mentioned technical problems.

[0005] The technical solution of the present invention is: a cleaning device and a cleaning method for a polytetrafluoroethylene filter element for semiconductors, characterized in that it comprises the following steps:

[0006] Step 1: soak the polytetrafluoroethylene filter element to be cleaned in an appropriate amount of isopropyl alcohol to wet it;

[0007] Step 2, soaking the polytetrafluoroethylene filter element in an appropriate amount of ultrapure aqueous solution;

[0008] Step 3, after the polytetrafluoroethylene filter element is installed in the circulation system, an appropriate amount of hydrochloric acid aqueous solution is added to the circulation system for long-term circulation flushing;

[0009] Step 4, after the acid solution is discharged, pure water is added to the circulation system for long-term circulation flushing;

[0010] Step five: Complete cleaning by rinsing and wet packaging in a clean room.

[0011] The present invention establishes an acid circulation system to perform long-term circulation cleaning on the filter element to ensure the initial and long-term cleanliness of the filter element. It can better meet the actual production needs of the polytetrafluoroethylene filter element, reduce metal precipitation during use, and enable the cleaned filter element to be applied to high-density integrated circuit production. At the same time, the second step of acid circulation flushing and the third step of pure water circulation flushing are both completed in the acid circulation system, and there is no need to repeatedly take the filter element, thereby reducing external pollution. Reduce metal precipitation and meet the requirement that the total metal precipitation is less than 10μ g / L. The second step of acid circulation flushing and the third step of pure water circulation flushing are both completed in the acid circulation system, and there is no need to repeatedly take the filter element, thereby reducing the number of operating steps.

[0012] Further preferably, the soaking time in step one is 30 minutes, the soaking time in step two is 10 minutes, the cycle time in step three is 24 hours, and the cycle time of step one is 24 hours.

[0013] Long-term cleaning cycle to ensure the initial and long-term cleanliness of the filter element.

[0014] More preferably, the concentration of the aqueous hydrochloric acid solution in step three is 10%.

[0015] Further preferably, the circulation system includes a circulation pump, a liquid storage tank, an air intake pipeline, a circulation pipeline, a pipeline control valve, a float flowmeter, a pressure sensor and corresponding fixtures, and a sampling port is reserved.

[0016] It can ensure the circulation of liquid in the whole system and real-time sampling and detection.

[0017] Further preferably, the circulation system is also provided with a liquid drain port.

[0018] The remaining liquid in the system can be drained while performing the next step.

[0019] Further preferably, the liquid storage tank is provided with an exhaust port and an air inlet.

[0020] Used to inject gas and exhaust excess gas, the gas helps to promote the activity of the liquid in the tank.

[0021] Further preferably, the top of the liquid storage tank is provided with three openings, and the bottom of the liquid storage tank is provided with two openings.

[0022] The liquid storage tank can be operated conveniently. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a flow chart of the circulation system of the present invention.

[0024] Reference numerals: circulation pump 1 , liquid storage tank 2 , float flowmeter 3 , pressure sensor 4 , sampling port 5 , liquid discharge port 6 . DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the accompanying drawings. Specific embodiment 1

[0027] See also Figure 1 , a cleaning device and a cleaning method for a polytetrafluoroethylene filter element for semiconductors, comprising the following steps:

[0028] Step 1: soak the polytetrafluoroethylene filter element to be cleaned in an appropriate amount of isopropyl alcohol to wet it;

[0029] Step 2, soaking the polytetrafluoroethylene filter element in an appropriate amount of ultrapure aqueous solution;

[0030] Step 3, after the polytetrafluoroethylene filter element is installed in the circulation system, an appropriate amount of hydrochloric acid aqueous solution is added to the circulation system for long-term circulation flushing;

[0031] Step 4, after the acid solution is discharged, pure water is added to the circulation system for long-term circulation flushing;

[0032] Step five: Complete cleaning by rinsing and wet packaging in a clean room.

[0033] The present invention establishes an acid circulation system to perform long-term circulation cleaning on the filter element to ensure the initial and long-term cleanliness of the filter element. It can better meet the actual production needs of the polytetrafluoroethylene filter element, reduce metal precipitation during use, and enable the cleaned filter element to be applied to high-density integrated circuit production. At the same time, the second step of acid circulation flushing and the third step of pure water circulation flushing are both completed in the acid circulation system, and there is no need to repeatedly take the filter element, thereby reducing external pollution. Reduce metal precipitation and meet the requirement that the total metal precipitation is less than 10μ g / L. The second step of acid circulation flushing and the third step of pure water circulation flushing are both completed in the acid circulation system, and there is no need to repeatedly take the filter element, thereby reducing the number of operating steps.

[0034] More preferably, the soaking time in step 1 is 30 minutes, the soaking time in step 2 is 10 minutes, the circulation time in step 3 is 24 hours, and the circulation time in step 4 is 24 hours. Long-term cyclic cleaning ensures the initial and long-term cleanliness of the filter element.

[0035] More preferably, the concentration of the aqueous hydrochloric acid solution in step three is 10%.

[0036] Further preferably, the circulation system includes a circulation pump 1, a liquid storage tank 2, an air intake pipeline, a circulation pipeline, a pipeline control valve, a float flowmeter 3, a pressure sensor 4 and corresponding fixtures, and a sampling port 5 is reserved, which can ensure the circulation of liquid in the whole system and real-time sampling and detection.

[0037] Further preferably, the circulation system is further provided with a liquid drain port 6, which can drain the residual liquid in the system when the next operation is performed.

[0038] Further preferably, the liquid storage tank is provided with an exhaust port and an air inlet for injecting gas and exhausting excess gas, and the gas helps to promote the activity of the liquid in the tank.

[0039] More preferably, the top of the liquid storage tank is provided with three openings, and the bottom of the liquid storage tank is provided with two openings, so that the liquid storage tank can be operated conveniently.

[0040] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A cleaning device and method for a polytetrafluoroethylene filter element for semiconductors, characterized in that: The steps include: Step 1: soak the polytetrafluoroethylene filter element to be cleaned in an appropriate amount of isopropyl alcohol to moisten it; Step 2, soaking the polytetrafluoroethylene filter element in an appropriate amount of ultrapure aqueous solution; Step 3, after the polytetrafluoroethylene filter element is installed in the circulation system, an appropriate amount of hydrochloric acid aqueous solution is added to the circulation system for long-term circulation flushing; Step 4, after the acid solution is discharged, pure water is added to the circulation system for long-term circulation flushing; Step five: Complete cleaning by rinsing and wet packaging in a clean room.

2. The cleaning device and method for a polytetrafluoroethylene filter element for semiconductors according to claim 1, characterized in that: The soaking time in step one is 30 minutes, the soaking time in step two is 10 minutes, the cycle time in step three is 24 hours, and the cycle time in step one is 24 hours.

3. The cleaning device and method for a polytetrafluoroethylene filter element for semiconductors according to claim 1, characterized in that: The concentration of the hydrochloric acid aqueous solution in step 3 is 10%.

4. The cleaning device and method for a polytetrafluoroethylene filter element for semiconductors according to claim 1, characterized in that: The circulation system includes a circulation pump, a liquid storage tank, an air intake pipeline, a circulation pipeline, a pipeline control valve, a float flowmeter, a pressure sensor and corresponding fixtures, and a sampling port is reserved.

5. The cleaning device and method for a polytetrafluoroethylene filter element for semiconductors according to claim 4, characterized in that: The circulation system is also provided with a liquid discharge port.

6. The cleaning device and method for a polytetrafluoroethylene filter element for semiconductors according to claim 4, characterized in that: The liquid storage tank is provided with an exhaust port and an air inlet.

7. The cleaning device and method for a polytetrafluoroethylene filter element for semiconductors according to claim 4, characterized in that: The top of the liquid storage tank is provided with three openings, and the bottom of the liquid storage tank is provided with two openings.

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