Method for detecting water-soluble anions in photoresist

Abstract

The invention provides a method for detecting water-soluble anions in photoresist, which comprises the following steps of: mixing a photoresist sample with water, separating to obtain a water-phase extracting solution, measuring the content of the water-soluble anions in the extracting solution, and calculating to obtain the content of the water-soluble anions in the photoresist sample. According to the method, the pretreatment procedure of the photoresist sample is simple, the ion content of the extracting solution obtained after pretreatment is directly tested, an expensive combustion furnace-ion chromatograph does not need to be used, and the cost is low; and the content of each water-soluble anion in the photoresist can be accurately measured.

Description

Technical Field

[0001] The present invention relates to the technical field of photoresist detection, in particular to a method for detecting water-soluble anions in photoresist. Background Art

[0002] For the detection of trace anions in photoresists, the currently commonly used detection method is the CIC online combustion ion chromatography method launched by Thermo Fisher Scientific to determine the halogens in photoresists and resins. Through combustion, the matrix of the photoresist and resin samples is completely eliminated, allowing the simultaneous analysis of all halogen contents in the sample with a single injection. However, this method requires a dedicated combustion furnace-ion chromatograph (dedicated machine) for photoresist and resin samples, which has high equipment costs. In addition, the result of the post-combustion test is the total halogen content in the photoresist, and does not include anions such as sulfate, phosphate, and nitrate. The test result is incomplete and cannot accurately determine the anion content in the photoresist and resin samples. Summary of the Invention

[0003] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a method for detecting water-soluble anions in photoresist, which is used to solve the problems of high detection cost and inability to accurately determine the anion content in photoresist in the prior art.

[0004] To achieve the above-mentioned purpose and other related purposes, the present invention is achieved through the following technical solutions.

[0005] The present invention provides a method for detecting water-soluble anions in photoresist. The method comprises the following steps: mixing a photoresist sample with water, performing separation treatment to obtain an aqueous phase extract, measuring the content of water-soluble anions in the extract, and then calculating the content of water-soluble anions in the photoresist sample.

[0006] Preferably, the water-soluble anions are selected from one or more of fluoride ions, chloride ions, bromide ions, nitrate ions, nitrite ions, sulfate ions and phosphate ions.

[0007] Preferably, ultrasound and / or vortexing are used during mixing, which can accelerate the extraction speed.

[0008] More preferably, the ultrasonication time is 15 to 45 minutes, such as 15 to 25 minutes, 25 to 30 minutes, 30 to 35 minutes, or 35 to 45 minutes, and further preferably 25 to 35 minutes.

[0009] Preferably, the separation is performed by centrifugal phase separation and / or microfiltration.

[0010] More preferably, the centrifugation time is 30 to 45 minutes, such as 30 to 40 minutes or 40 to 45 minutes.

[0011] More preferably, the centrifugal speed is 3000-5000 rpm.

[0012] More preferably, the pore size of the microfiltration membrane is 0.22 to 0.5 μm.

[0013] More preferably, the pore size of the microfiltration membrane is 0.22 μm.

[0014] Preferably, the water is ultrapure water.

[0015] Preferably, during mixing, the temperature of the mixing system is 15°C<T<25°C.

[0016] Preferably, when mixed, the mass volume ratio of the photoresist sample to water is 1: (5-20) g / mL.

[0017] Preferably, the content of water-soluble anions in the extract is determined by ion chromatography.

[0018] More preferably, an ion chromatograph is used to test the extract and each anion series concentration standard solution to obtain the corresponding chromatographic peak area; a standard working curve is obtained based on the concentration of each anion series concentration standard solution and the corresponding chromatographic peak area; and then the concentration of each anion in the extract is obtained based on the chromatographic peak area corresponding to the extract and the standard working curve.

[0019] More preferably, the detection conditions of the ion chromatography include:

[0020] The chromatographic column was an AS-11 ion chromatography column; the guard column was an anion guard column; the flow rate was 0.1-0.5 mL / min; the column oven temperature was 10°C-20°C; the injection volume was 400-600 μL; the suppressor temperature was 10-30°C; and the eluent was potassium hydroxide solution.

[0021] The gradient elution program was:

[0022] From 0 to 5 minutes, the concentration of potassium hydroxide solution increased from 0 to 1 mg / L to 4.5 to 5.5 mg / L;

[0023] In 5 to 13 minutes, the concentration of potassium hydroxide solution increased from 4.5 to 5.5 mg / L to 17.5 to 18.5 mg / L;

[0024] At 13-18 minutes, the concentration of potassium hydroxide solution increased from 17.5-18.5 mg / L to 39.5-40.5 mg / L;

[0025] From 18 to 23 minutes, the concentration of potassium hydroxide solution was maintained at 39.5 to 40.5 mg / L;

[0026] Within 23 to 23.5 minutes, the concentration of potassium hydroxide solution decreased from 39.5 to 40.5 mg / L to 0 to 1 mg / L.

[0027] Further preferably, the detection conditions of the ion chromatography include:

[0028] The chromatographic column was an AS-11 ion chromatography column; the guard column was an anion guard column; the flow rate was 0.38 mL / min; the column oven temperature was 15°C; the injection volume was 500 μL; the suppressor temperature was 20°C; and the eluent was potassium hydroxide solution.

[0029] The gradient elution program was:

[0030] From 0 to 5 minutes, the concentration of potassium hydroxide solution increased from 1 mg / L to 5 mg / L;

[0031] From 5 to 13 minutes, the concentration of potassium hydroxide solution increased from 5 mg / L to 18 mg / L;

[0032] From 13 to 18 minutes, the concentration of potassium hydroxide solution increased from 18 mg / L to 40 mg / L;

[0033] From 18 to 23 minutes, the concentration of potassium hydroxide solution was maintained at 40 mg / L;

[0034] From 23 to 23.5 minutes, the concentration of potassium hydroxide solution dropped from 40 mg / L to 1 mg / L.

[0035] The solvent in the potassium hydroxide solution is ultrapure water.

[0036] Preferably, the ion chromatography method comprises the following specific steps:

[0037] S1. Preparation of standard solutions: Prepare a series of water-soluble anion standard solutions;

[0038] S2. Quantitative detection: The extract and the standard solution are quantitatively analyzed by ion chromatography, respectively, and the standard curve method is used for quantitative analysis to obtain the content of water-soluble anions in the extract.

[0039] Preferably, the content of water-soluble anions in the photoresist sample is calculated based on the content of water-soluble anions in the extract obtained by the test and the following formula, wherein C=(C1-C0)*V / m, wherein C1 is the content of water-soluble anions in the extract obtained by the test, mg / L; C0 is the content of water-soluble anions in the blank control solution obtained by the test, mg / L, and the blank control solution is an ultrapure water solution obtained by mixing and separating propylene glycol methyl ether acetate instead of photoresist, and the mass volume ratio of propylene glycol methyl ether acetate and the ultrapure water is consistent with the mass volume ratio of the photoresist sample and the water; V is the volume of the extract, mL; m is the mass of the photoresist sample, g; and C is the content of water-soluble anions in the photoresist sample, μg / g.

[0040] This application uses ultrapure water to extract water-soluble anions from a photoresist sample. After separation, the extract is obtained, the water-soluble anion content of the extract is measured, and the water-soluble anion content of the photoresist sample is calculated. This method simplifies the pretreatment process of the photoresist sample, and the ion content of the extract obtained after pretreatment can be directly tested, eliminating the need for an expensive combustion furnace-ion chromatograph and reducing costs. Furthermore, the content of each water-soluble anion (halogen ion, sulfate ion, nitrate ion, nitrite ion, and phosphate ion) in the photoresist can be accurately measured. DETAILED DESCRIPTION

[0041] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0042] It should be noted that the process equipment or devices not specifically specified in the following embodiments are all conventional equipment or devices in the art.

[0043] Furthermore, it should be understood that the reference to one or more method steps in the present invention does not preclude the presence of other method steps before or after the combination of steps, or the insertion of other method steps between these explicitly mentioned steps, unless otherwise specified. It should also be understood that the reference to one or more devices / apparatuses in the present invention as a combined connection relationship does not preclude the presence of other devices / apparatuses before or after the combination of devices / apparatuses, or the insertion of other devices / apparatuses between two explicitly mentioned devices / apparatuses, unless otherwise specified. Furthermore, unless otherwise specified, the numbering of each method step is merely a convenient tool for identifying the method steps, and is not intended to limit the order of the method steps or the scope of the present invention. Any changes or adjustments to their relative relationships, without substantively altering the technical content, should be considered within the scope of the present invention.

[0044] The reagents and instruments used in the following examples are all commonly used reagents and instruments, which can be purchased from the market, as follows:

[0045] 1. Reagents

[0046] Anion standard solution (BW091001, 5 μg / mL, Henan Standard Material Research and Development Center): Contains fluoride, chloride, bromide, nitrate, nitrite, sulfate, and phosphate, with each ion concentration at 5 μg / mL;

[0047] Ultrapure water (ultrapure water device homemade, ultrapure water device model IQ Element);

[0048] Propylene glycol methyl ether acetate, purity G6;

[0049] The photoresist sample in the embodiment is ultraviolet photoresist.

[0050] 2. Instruments

[0051] An ion chromatograph (ICS 6000, Thermo Fisher Scientific, USA) was used, the chromatographic column was an AS-11 ion chromatographic column, a heated ultrasonic cleaner (UC-22.5H), a centrifuge (800D), and a polytetrafluoroethylene filter membrane (specification: 0.22 μm).

[0052] Example 1

[0053] (1) Preparation of standard solutions: Dilute the anion standard solution (5 μg / mL) with ultrapure water to prepare five standard solutions with concentrations of 0.05 mg / L, 0.10 mg / L, 0.20 mg / L, 0.50 mg / L, and 1.00 mg / L, respectively.

[0054] (2) Pretreatment of photoresist samples: Take 1.0 g of photoresist sample and place it in a polypropylene or high-density polyethylene centrifuge bottle, dilute it to 10 mL with ultrapure water, tighten the bottle cap, and sonicate for 30 minutes. During the sonication process, the bottle cap is slightly loosened to release some organic gas. After the sonication, centrifuge to obtain the aqueous phase at a centrifugal speed of 4000 rpm for 30 minutes. Then, filter the aqueous phase through a 0.22 μm filter membrane to obtain the extract.

[0055] (3) Preparation of blank control sample: Take 1.0 g of propylene glycol methyl ether acetate instead of the photoresist sample and prepare according to step (2).

[0056] (4) Detection: The extract prepared in step (2) and the standard solution prepared in step (1) were subjected to ion chromatography analysis, and quantitative determination was performed using a standard curve method to obtain the contents of the seven anions in the extract.

[0057] Specifically, the standard curve method is to first perform ion chromatography on the standard solutions prepared in step (1) to obtain a linear relationship between the concentration of the standard solutions of the seven anions and the chromatographic peak area, draw a corresponding standard working curve, use the concentration of the standard solutions of the seven anions as the horizontal axis and the chromatographic peak area as the vertical axis, calculate the regression equation, and after the extract is sampled, calculate the concentration of the seven anions in the extract based on the peak area of the chromatographic peak.

[0058] The regression equation of fluoride ion is y=21.7077x+0.4297, and the linear relationship of the regression equation is good, and the correlation coefficient r is 0.9995.

[0059] The regression equation of chloride ion is y=15.2976x+0.0530. The linear relationship of the regression equation is good, and the correlation coefficient r is 1.0000.

[0060] The regression equation of bromide ion is y=6.4554x-0.0067, and the linear relationship of the regression equation is good, and the correlation coefficient r is 1.0000.

[0061] The regression equation of nitrate ion is y=8.882x+0.0215. The linear relationship of the regression equation is good, and the correlation coefficient r is 1.0000.

[0062] The regression equation of nitrite ion is y=8.9821x+0.1708, and the linear relationship of the regression equation is good, and the correlation coefficient r is 0.9997.

[0063] The regression equation of sulfate ion is y=10.8849x+0.0504, and the linear relationship of the regression equation is good, and the correlation coefficient r is 1.0000.

[0064] The regression equation of phosphate ion is y=4.8661x+0.0014, and the linear relationship of the regression equation is good, and the correlation coefficient r is 1.0000.

[0065] (5) Determination of anion content in the photoresist sample: The anion content in the extract calculated in step (4) is substituted into the formula C = (C1-C0)*V / m, wherein C1 is the water-soluble anion content in the extract obtained by the test, mg / L; C0 is the water-soluble anion content in the blank control obtained by the test, mg / L; V is the volume of the extract, mL; m is the mass of the photoresist sample, g; and C is the water-soluble anion content in the photoresist sample, ug / g.

[0066] Wherein, the detection conditions of the ion chromatography are:

[0067] The chromatographic column used was an AS-11 ion chromatography column, the guard column used was an anion guard column, the injection volume was 500 μL, the flow rate was 0.38 ml / min, the column temperature was 15°C, the suppressor temperature was 20°C, the eluent was potassium hydroxide solution, and the gradient elution program was as follows:

[0068]

[0069] Example 2

[0070] 1. Detection limits of fluoride, chloride, bromide, nitrate, nitrite, sulfate and phosphate by ion chromatography

[0071] Anion standard solutions were used to prepare test solutions with an anion concentration of 0.01 mg / L. The samples were injected 11 times and 11 test results were obtained by ion chromatography. The standard deviation of the 11 test results was calculated, and 3 times the standard deviation was used as the detection limit of the test solution. The calculation results are shown in Table 1.

[0072] Table 1

[0073] Anions <![CDATA[F - ]]> <![CDATA[Cl - ]]> <![CDATA[NO 2- ]]> <![CDATA[Br - ]]> <![CDATA[NO3 - ]]> <![CDATA[SO4 2- ]]> <![CDATA[PO4 3- ]]> Standard Deviation 0.00019 0.000288 0.000302 0.000138 0.000323 0.00032 0.000245 Detection limit mg / L 0.0006 0.0009 0.0009 0.0004 0.0010 0.0010 0.0007

[0074] 2. Precision and recovery

[0075] The standard solution prepared in step (1) of Example 1 was used as the test solution to perform method precision tests and recovery tests at low, medium and high concentrations. The test solution selected standard solutions with concentrations of 0.05 mg / L, 0.50 mg / L and 1.00 mg / L, respectively, and 6 parallel measurements were performed to determine the content of each water-soluble anion in the test solution. The test method was the same as that in Example 1, and the average content of the test solution of the 6 test results was calculated.

[0076] A blank control sample was prepared using the method of step (3) in Example 1, and the content of each water-soluble anion in the blank control sample was tested using the same testing method as in Example 1.

[0077] The relative standard deviation was calculated based on the average of the six test solution contents, the blank control content, and the test solution content. The recovery was calculated based on the average of the test solution content, the blank control content, and the test solution concentration. The results are shown in Tables 2 to 4.

[0078] Table 2 Test results of low concentration

[0079]

[0080] Test results of concentrations in Table 3

[0081]

[0082] Table 4 Test results of high concentration

[0083]

[0084]

[0085] From Tables 2 to 4, we can see that:

[0086] When detecting 7 kinds of anions, the relative standard deviations at low, medium and high concentrations ranged from 0.35 to 4.61%, all less than 10%, indicating good precision, indicating that the method has good reproducibility.

[0087] When seven anions were detected, the recovery rates ranged from 92.0% to 105%, which was good and met the requirements of trace analysis.

[0088] Example 3

[0089] This embodiment provides a method for measuring a photoresist sample. The test method is as follows:

[0090] The method in Example 1 was used to test and calculate the content of water-soluble anions in commercially available photoresist samples, and quality control analyses such as blank controls, parallel samples, and spiked samples were performed.

[0091] Sample pretreatment: Place 1.0 g of photoresist sample in a polypropylene or high-density polyethylene centrifuge bottle, dilute to 10 mL with the solution, tighten the cap, and sonicate for 30 minutes. During sonication, loosen the cap slightly to release some organic gases. After sonication, centrifuge at 4000 rpm for 30 minutes to obtain an aqueous phase. Filter the aqueous phase through a 0.22 μm filter to obtain the spiked sample extract. This solution contains fluoride, chloride, nitrate, bromide, nitrite, sulfate, and phosphate ions at a concentration of 0.5 mg / L each. Ultrapure water is used as the solvent.

[0092] The obtained spiked sample extract was tested and calculated using the method in Example 1 to determine the content of water-soluble anions spiked in commercially available photoresist samples. The spiked recovery was calculated using the formula (average value of spiked extract content - average value of extract content) / 0.5.

[0093] The calculation results are shown in Table 5.

[0094] Table 5

[0095]

[0096]

[0097] As can be seen from Table 5, the spiked recovery rate is 92.2-108.8%, indicating that the photoresist matrix has little interference with the extraction of water-soluble anions, and almost all the water-soluble anions in the photoresist sample are extracted into ultrapure water. The detection method provided in this application can accurately detect the content of various water-soluble anions in the photoresist sample.

[0098] This detection method meets the requirements of relevant analytical tests, can quickly and accurately determine the concentration levels of various water-soluble anions in photoresist, and can quickly and accurately evaluate whether the content of various water-soluble anions in photoresist samples meets the standards, thereby evaluating whether the photoresist samples are qualified.

[0099] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A method for detecting water-soluble anions in a photoresist, characterized in that: The photoresist sample and water are mixed, and an aqueous phase extract is obtained by separation treatment. The content of water-soluble anions in the extract is measured, and then the content of water-soluble anions in the photoresist sample is calculated.

2. The detection method according to claim 1, wherein During mixing, ultrasound and / or vortexing are used; and / or the water-soluble anions are selected from one or more of fluoride ions, chloride ions, bromide ions, nitrate ions, nitrite ions, sulfate ions and phosphate ions.

3. The detection method according to claim 2, characterized in that The ultrasound time is 15 to 45 minutes.

4. The detection method according to claim 1, wherein The water is ultrapure water.

5. The detection method according to claim 1, wherein The separation is carried out by centrifugal phase separation and / or microfiltration.

6. The detection method according to claim 4, characterized in that The centrifugation time is 30 to 45 minutes; and / or the centrifugation speed is 3000 to 5000 rpm; and / or the pore size of the microfiltration membrane is 0.22 to 0.5 μm; and / or the microfiltration uses a polytetrafluoroethylene filter membrane.

7. The detection method according to claim 1, characterized in that During mixing, the temperature of the mixed system is 15℃<T<50℃; And / or, when mixed, the mass volume ratio of the photoresist sample to water is 1: (5-20) g / mL.

8. The detection method according to claim 1, wherein The content of water-soluble anions in the extract is determined by ion chromatography.

9. The detection method according to claim 8, characterized in that The detection conditions of the ion chromatography method include one or more of the following characteristics: a) The chromatographic column is AS-11 ion chromatography column; b) the guard column is an anion guard column; c) Flow rate of 0.1 to 0.5 mL / min; d) The column box temperature is 10℃~20℃; e) The injection volume is 400-600 μL; f) The suppressor temperature is 10-30°C; g) The eluent is potassium hydroxide solution; h) Gradient elution program is: From 0 to 5 minutes, the concentration of potassium hydroxide solution increased from 0 to 1 mg / L to 4.5 to 5.5 mg / L; In 5 to 13 minutes, the concentration of potassium hydroxide solution increased from 4.5 to 5.5 mg / L to 17.5 to 18.5 mg / L; At 13-18 minutes, the concentration of potassium hydroxide solution increased from 17.5-18.5 mg / L to 39.5-40.5 mg / L; From 18 to 23 minutes, the concentration of potassium hydroxide solution was maintained at 39.5 to 40.5 mg / L; Within 23 to 23.5 minutes, the concentration of potassium hydroxide solution decreased from 39.5 to 40.5 mg / L to 0 to 1 mg / L.

10. The detection method according to claim 1, characterized in that The content of water-soluble anions in the photoresist sample is calculated according to the content of water-soluble anions in the extract obtained by the test and the following formula, wherein C=(C1-C0)*V / m, wherein C1 is the content of water-soluble anions in the extract obtained by the test, mg / L; C0 is the content of water-soluble anions in the blank control solution obtained by the test, mg / L; the blank control solution is an ultrapure water solution after mixed and separated with propylene glycol methyl ether acetate instead of photoresist, and the mass volume ratio of propylene glycol methyl ether acetate and the ultrapure water is consistent with the mass volume ratio of the photoresist sample and the water; V is the volume of the extract, mL; m is the mass of the photoresist sample, g; and C is the content of water-soluble anions in the photoresist sample, μg / g.

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