Method for detecting ultra-trace ionic pollutants in clean gas

Abstract

The invention relates to the technical field of detection. The invention relates to a method for detecting ultra-trace ionic pollutants in clean gas, which comprises the following steps: S1, accelerating the precipitation of target ionic pollutants in an impact type absorption bottle by using a dust-free drying oven; s2, carrying out ultrasonic cleaning on residual target ion pollution; s3, a sealing object is additionally arranged at the joint of the absorption bottle, and external pollution is prevented; s4, a fixing device is added, meanwhile, low-temperature transportation is conducted, and precipitation of target ion pollutants in the absorption bottle is reduced; and S5, collecting data, and evaluating a pollution control result. The invention discloses an analysis method for quantitatively detecting ultra-trace ionic pollutants in clean gas based on an impact type absorption bottle sampling method, and solves the problem that the ultra-trace ionic pollutants cannot be quantitatively detected in the prior art.

Description

Technical Field

[0001] The invention relates to the field of detection technology, and in particular to an ultra-trace detection method for ions. Background Art

[0002] In the semiconductor and integrated circuit manufacturing industry, high-purity clean gas is widely used in the production process of atmosphere protection, cleaning, purging and other processes to ensure the quality of semiconductor and integrated circuit products. It is an indispensable auxiliary material in the production process of semiconductor materials and components. Therefore, it is very important to detect ultra-trace ion contamination in clean gas, monitor the cleanliness of clean gas, and ensure production quality.

[0003] At present, the quantitative detection of F in clean gas by ion chromatography is - 、CH3COO - HCOO - , Cl - 、NO2 - Br - 、NO3 - 、SO4 2 -, PO4 3- NH4 + The detection method can only reach the trace level. As the semiconductor industry has higher and higher requirements for the use of clean gases, the existing detection methods cannot achieve the problem of quantitative detection of ultra-trace ion contamination and cannot meet the development needs of the industry. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a method for detecting ultra-trace ion pollutants in clean gas, which has solved at least one of the above technical problems.

[0005] The technical solution of the present invention is: a method for detecting ultra-trace ion pollutants in clean gas, characterized in that it comprises the following steps:

[0006] S1: Use a dust-free oven to accelerate the precipitation of target ion pollutants in the impact absorption bottle;

[0007] S2: Ultrasonic cleaning of remaining target ion contamination;

[0008] S3: Add sealant to the joint of the absorption bottle to prevent external contamination;

[0009] S4: Add fixtures and transport at low temperatures to reduce the precipitation of target ion pollutants in the absorption bottle;

[0010] S5: Collect data and evaluate pollution control results.

[0011] Further preferably, the specific method of S1 is as follows:

[0012] S1.1: Carry out relevant operations in a clean room of Class 5 or higher level specified in ISO 14644-1; the clean room should be equipped with a dust-free heating device and ultrapure water with a resistivity of ≥18MΩ;

[0013] S1.2: Assemble the absorption bottle and inject ultrapure water from the air inlet of the absorption bottle to ensure that the interior of the absorption bottle is completely filled with ultrapure water without obvious bubbles;

[0014] S1.3: Place the absorption bottle filled with water into a PE barrel, and fill the PE barrel with ultrapure water to ensure that the ultrapure water in the PE barrel completely immerses the absorption bottle; cover the PE barrel lid tightly to reduce the volatilization of ultrapure water;

[0015] S1.4: Place the PE barrel containing the absorption bottle in a dust-free oven at 85°C for 28 days. Replace the ultrapure water inside and outside the absorption bottle every seven days.

[0016] The specific method of S2 is as follows:

[0017] S2.1: Add new ultrapure water to the absorption bottle and put it into the PE barrel again for soaking;

[0018] S2.2: During ultrasonic cleaning, the ultrasonic power is 600w and the ultrasonic cleaning is performed for 1 hour.

[0019] Further preferably, the sealant includes at least one of a sealing film, a raw tape, a rubber sleeve and a clean bag.

[0020] Further preferably, the specific method of S3 is as follows:

[0021] S3.1: quantitatively add 60 mL of ultrapure water as the absorption liquid and tighten the absorption bottle;

[0022] S3.2: Use a clean sealing film to tightly wrap the joints of the absorption bottle for 3 to 5 times; then, use the same method to seal the inlet and outlet of the absorption bottle; in addition, a layer of rubber sleeve is reinforced on the outer layer of the inlet and outlet.

[0023] S3.3: The sealed absorption bottle is packed in a clean PE bag with two layers, the inner layer is 90% vacuum and the outer layer is completely vacuum packed.

[0024] Further preferably, the specific method of S4 is as follows:

[0025] S4.1: Take four blue ice packs of 15*10 cm in size, 15 cm in length and 10 cm in width, and place them in a refrigerated transport box;

[0026] S4.2: Place the sealed absorption bottles, opening upward, in a low-temperature refrigerator in order.

[0027] Further preferably, the specific method of S5 is as follows:

[0028] S5.1: Adjust the pipeline gas flow rate to 1L / min, connect the absorption bottle and the anti-backflow bottle, and continue sampling for 8 hours; at the same time, place an absorption bottle without PE outer packaging as a blank for the whole procedure;

[0029] S5.2: Add the absorption liquid in the absorption bottle to a volume of 60 mL;

[0030] S5.3: Use the ion chromatography analyzer to test and use the following formula to calculate the evaluation results:

[0031] C=[(ρ1-ρ0)*df*v1] / v2*1000;

[0032] Where C is the mass concentration of the ion, in ng / m 3 ; ρ1 is the measured concentration of the absorption solution, unit ng / L; ρ0 is the measured concentration of the blank solution of the whole procedure, unit ng / L; df is the dilution factor of the extraction solution; v1 is the volume of the extraction solution, unit L; v2 is the volume of the collected clean gas, unit L.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The present invention proposes an analytical method for quantitatively detecting ultra-trace ion pollutants in clean gas based on an impact absorption bottle sampling method, thereby solving the problem that the prior art cannot achieve quantitative detection of ultra-trace ion pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic diagram of a specific embodiment 1 of the present invention. DETAILED DESCRIPTION

[0036] See also Figure 1 , Specific embodiment 1, a method for detecting ultra-trace ion pollutants in clean gas, characterized in that it includes the following steps:

[0037] S1: Use a dust-free oven to accelerate the precipitation of target ion pollutants in the impact absorption bottle;

[0038] S2: Ultrasonic cleaning of remaining target ion contamination;

[0039] S3: Add sealant to the joint of the absorption bottle to prevent external contamination;

[0040] S4: Add fixtures and transport at low temperatures to reduce the precipitation of target ion pollutants in the absorption bottle;

[0041] S5: Collect data and evaluate pollution control results.

[0042] The specific method of S1 is as follows:

[0043] S1.1: Carry out relevant operations in a clean room of Class 5 or higher level specified in ISO 14644-1; the clean room should be equipped with a dust-free heating device and ultrapure water with a resistivity of ≥18MΩ;

[0044] S1.2: Assemble the absorption bottle and inject ultrapure water from the air inlet of the absorption bottle to ensure that the interior of the absorption bottle is completely filled with ultrapure water without obvious bubbles;

[0045] S1.3: Place the absorption bottle filled with water into a PE barrel, and fill the PE barrel with ultrapure water to ensure that the ultrapure water in the PE barrel completely immerses the absorption bottle; cover the PE barrel lid tightly to reduce the volatilization of ultrapure water;

[0046] S1.4: Place the PE barrel containing the absorption bottle in a dust-free oven at 85°C for 28 days. Replace the ultrapure water inside and outside the absorption bottle every seven days.

[0047] The specific method of S2 is as follows:

[0048] S2.1: Add new ultrapure water to the absorption bottle and put it into the PE barrel again for soaking;

[0049] S2.2: During ultrasonic cleaning, the ultrasonic power is 600w and the ultrasonic cleaning is performed for 1 hour.

[0050] The sealant comprises at least one of a sealing film, a raw tape, a rubber sleeve and a clean bag.

[0051] The specific method of S3 is as follows:

[0052] S3.1: Add 60 mL of ultrapure water quantitatively, generally not exceeding 2 / 3 of the volume of the absorption bottle, as the absorption liquid, and tighten the absorption bottle;

[0053] S3.2: Use a clean sealing film to tightly wrap the joints of the absorption bottle for 3 to 5 times; then, use the same method to seal the inlet and outlet of the absorption bottle; in addition, a layer of rubber sleeve is reinforced on the outer layer of the inlet and outlet.

[0054] S3.3: The sealed absorption bottle is packed in a clean PE bag with two layers, the inner layer is 90% vacuum and the outer layer is completely vacuum packed.

[0055] The specific method of S4 is as follows:

[0056] S4.1: Take four blue ice packs of 15*10 cm in size, 15 cm in length and 10 cm in width, and place them in a refrigerated transport box;

[0057] S4.2: Place the sealed absorption bottles, opening upward, in a low-temperature refrigerator in order.

[0058] S5 specific methods are as follows:

[0059] S5.1: Adjust the pipeline gas flow rate to 1L / min, connect the absorption bottle and the anti-backflow bottle, and continue sampling for 8 hours; at the same time, place an absorption bottle without PE outer packaging as a blank for the whole procedure;

[0060] S5.2: Add the absorption liquid in the absorption bottle to a volume of 60 mL;

[0061] S5.3: Use the ion chromatography analyzer to test and use the following formula to calculate the evaluation results:

[0062] C=[(ρ1-ρ0)*df*v1] / v2*1000;

[0063] Where C is the mass concentration of the ion, in ng / m 3 ; ρ1 is the measured concentration of the absorption solution, unit ng / L; ρ0 is the measured concentration of the blank solution of the whole procedure, unit ng / L; df is the dilution factor of the extraction solution; v1 is the volume of the extraction solution, unit L; v2 is the volume of the collected clean gas, unit L.

[0064] Table 1 shows the clean pipeline gas and process blank measurement data, the unit is ng / L Table 1

[0065]

[0066]

[0067] Table 2 shows the clean pipeline gas and process blank evaluation data in ng / m 3 , "ND" means that the ion was not detected; Table 2

[0068] Ion name Pipeline gas 1 Pipeline gas 2 F 3.3 4.4 <![CDATA[CH3COO - ]]> 20.2 15.5 <![CDATA[HCOO - ]]> 2.9 4.7 <![CDATA[Cl - ]]> 5.3 1.7 <![CDATA[NO2 - ]]> 0.9 0.8 <![CDATA[Br / ]]> ND ND <![CDATA[NO3 - ]]> 0.9 0.3 <![CDATA[SO4 2- ]]> 54.9 85.3 <![CDATA[PO4 3- ]]> ND ND <![CDATA[NH4 + ]]> 59.7 63.6

[0069] The data in Table 1 and Table 2 show that this method uses high-temperature immersion to clean the absorption bottle, isolates it from the external environment, and transports it at low temperature. The absorption bottle sampling method can be used to achieve ultra-trace F and CH3COO in clean gas. - HCOO - , Cl - 、NO2 - Br - 、NO3 - 、SO4 2- PO4 3- NH4 + Quantitative analysis of .

[0070] 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 method for detecting ultra-trace ionic pollutants in clean gas, characterized in that: The steps include: S1: Use a dust-free oven to accelerate the precipitation of target ion pollutants in the impact absorption bottle; S2: ultrasonic cleaning of remaining target ion contamination; S3: Add sealant to the joint of the absorption bottle to prevent external contamination; S4: Add fixtures and transport at low temperatures to reduce the precipitation of target ion pollutants in the absorption bottle; S5: Collect data and evaluate pollution control results.

2. The method for detecting ultra-trace ionic pollutants in clean gas according to claim 1, characterized in that: The specific method of S1 is as follows: S1.1: Perform relevant operations in a cleanroom of Class 5 or higher as specified in ISO 14644-1. The cleanroom should be equipped with a dust-free heating device and ultrapure water with a resistivity of ≥18MΩ. S1.2: Assemble the absorption bottle and inject ultrapure water from the air inlet of the absorption bottle to ensure that the absorption bottle is completely filled with ultrapure water without obvious bubbles; S1.3: Place the absorption bottle filled with water into a PE bucket. Fill the PE bucket with ultrapure water, ensuring that the ultrapure water in the PE bucket completely submerges the absorption bottle. Close the PE bucket lid tightly to reduce the evaporation of ultrapure water. S1.4: Place the PE barrel containing the absorption bottle in a dust-free oven at 85°C for 28 days. Replace the ultrapure water inside and outside the absorption bottle every seven days.

3. The method for detecting ultra-trace ionic pollutants in clean gas according to claim 1, wherein: The specific method of S2 is as follows: S2.1: Fill the absorption bottle with new ultrapure water and place it back into the PE barrel for immersion. S2.2: During ultrasonic cleaning, the ultrasonic power is 600w and the ultrasonic cleaning time is 1 hour.

4. The method for detecting ultra-trace ionic pollutants in clean gas according to claim 1, wherein: The sealant includes at least one of a sealing film, a raw tape, a rubber sleeve and a clean bag.

5. The method for detecting ultra-trace ionic pollutants in clean gas according to claim 1, wherein: The S3 specific method is as follows: S3.1: Add 60 mL of ultrapure water as the absorption solution and tighten the absorption bottle. S3.2: Use a clean sealing film to tightly wrap 3 to 5 circles around the joints of the absorption bottle; then, use the same method to seal the inlet and outlet of the absorption bottle; in addition, reinforce the outer layer of the inlet and outlet with a layer of rubber sleeve. S3.3: The sealed absorption bottle is packed in a clean PE bag with double layers; the inner layer is 90% vacuum and the outer layer is completely vacuum packed.

6. The method for detecting ultra-trace ionic pollutants in clean gas according to claim 1, characterized in that: The specific method of S4 is as follows: S4.1: Take four 15*10 cm blue ice packs, 15 cm long and 10 cm wide, and place them in a refrigerated transport box. S4.2: Place the sealed absorption bottles with the opening facing upward in an orderly manner into a low-temperature refrigerator.

7. The method for detecting ultra-trace ionic pollutants in clean gas according to claim 1, characterized in that: The specific method of S5 is as follows: S5.1: Adjust the pipeline gas flow rate to 1 L / min, connect the absorption bottle and the anti-backflow bottle, and continue sampling for 8 hours. At the same time, place an absorption bottle without PE outer packaging to serve as a blank for the entire procedure; S5.2: Add the absorption solution in the absorption bottle to a volume of 60 mL; S5.3: Use an ion chromatography instrument to perform the test and calculate the evaluation results using the following formula: C=[(ρ1-ρ0)*df*v1] / v2*1000; Where C is the mass concentration of the ion, in ng / m 3 ; ρ1 is the measured concentration of the absorption liquid, unit ng / L; ρ0 is the measured concentration of the blank solution of the whole procedure, unit ng / L; df is the dilution factor of the extraction liquid; v1 is the volume of the extraction liquid, unit L; v2 is the volume of the collected clean gas, unit L.

8. A method for detecting ultra-trace ionic pollutants in clean gas, characterized in that: The steps include: S1: Use a dust-free oven to accelerate the precipitation of target ion pollutants in the impact absorption bottle, as follows; S1.1: Perform relevant operations in a cleanroom of Class 5 or higher as specified in ISO 14644-1. The cleanroom should be equipped with a dust-free heating device and ultrapure water with a resistivity of ≥18MΩ. S1.2: Assemble the absorption bottle and inject ultrapure water from the air inlet of the absorption bottle to ensure that the absorption bottle is completely filled with ultrapure water without obvious bubbles; S1.3: Place the absorption bottle filled with water into a PE bucket. Fill the PE bucket with ultrapure water, ensuring that the ultrapure water in the PE bucket completely submerges the absorption bottle. Close the PE bucket lid tightly to reduce the evaporation of ultrapure water. S1.4: Place the PE barrel containing the absorption bottle in a dust-free oven at 85°C for 28 days. Replace the ultrapure water inside and outside the absorption bottle every seven days. S2: Ultrasonic cleaning of remaining target ion contamination, as follows; S2.1: Fill the absorption bottle with new ultrapure water and place it back into the PE barrel for immersion. S2.2: During ultrasonic cleaning, the ultrasonic power is 600w and the ultrasonic cleaning is performed for 1 hour; S3: Add sealants to the connection of the absorption bottle to prevent external contamination, as follows; S3.1: Add 60 mL of ultrapure water as the absorption solution and tighten the absorption bottle. S3.2: Use a clean sealing film to tightly wrap 3 to 5 circles around the joints of the absorption bottle; then, use the same method to seal the inlet and outlet of the absorption bottle; in addition, reinforce the outer layer of the inlet and outlet with a layer of rubber sleeve. S3.3: The sealed absorption bottle is packed in a clean PE bag, with the inner layer being 90% vacuum-packed and the outer layer being completely vacuum-packed. S4: Add fixtures and transport at low temperatures to reduce the precipitation of target ion pollutants in the absorption bottle, as follows; S4.1: Take four 15*10 cm blue ice packs, 15 cm long and 10 cm wide, and place them in a refrigerated transport box. S4.2: Place the sealed absorption bottles, opening upward, in a low-temperature refrigerator in an orderly manner; S5: Collect data and evaluate the pollution control results, as follows; S5.1: Adjust the pipeline gas flow rate to 1 L / min, connect the absorption bottle and the anti-backflow bottle, and continue sampling for 8 hours. At the same time, place an absorption bottle without PE outer packaging to serve as a blank for the entire procedure; S5.2: Add the absorption solution in the absorption bottle to a volume of 60 mL; S5.3: Use an ion chromatography instrument to perform the test and calculate the evaluation results using the following formula: C=[(ρ1-ρ0)*df*v1] / v2*1000; Where C is the mass concentration of the ion, in ng / m 3 ; ρ1 is the measured concentration of the absorption liquid, unit ng / L; ρ0 is the measured concentration of the blank solution of the whole procedure, unit ng / L; df is the dilution factor of the extraction liquid; v1 is the volume of the extraction liquid, unit L; v2 is the volume of the collected clean gas, unit L.

Images