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CN-121990532-A - Method for preparing electronic-grade hydroxylamine aqueous solution

CN121990532ACN 121990532 ACN121990532 ACN 121990532ACN-121990532-A

Abstract

The invention relates to a method for preparing an electronic grade hydroxylamine aqueous solution by using an industrial grade 50% hydroxylamine aqueous solution as a raw material and adopting microfiltration, ion exchange and nanofiltration combined technology. Firstly, adopting microfiltration pretreatment to remove suspended particles and colloid substances, then removing ion impurities by a specially modified ion exchange resin combined bed, and finally utilizing nanofiltration technology to obtain the high-purity product through deep purification. The invention has short process route, safe operation and low cost, can stably produce electronic-grade hydroxylamine aqueous solution, has the metal ion content of less than 10 ppt, the particle control particle diameter of more than 0.1 mu m and less than 50 pieces/ml, has the resistivity of 18.2M omega cm, and meets the industry requirements of semiconductor manufacture, integrated circuits and display panels.

Inventors

  • SUN JIN

Assignees

  • 北京袭明科技有限公司

Dates

Publication Date
20260508
Application Date
20260206

Claims (10)

  1. 1. A method of preparing an aqueous solution of electronic grade hydroxylamine, the method comprising the steps of: s1, microfiltration pretreatment, namely, passing an industrial 50% hydroxylamine aqueous solution through a polyvinylidene fluoride microfiltration membrane with a pore diameter of 0.1-0.2 mu m at a temperature of 15-25 ℃ under an operating pressure of 0.1-0.5 MPa to remove suspended particles and colloid substances; S2, ion exchange purification, namely sequentially passing the filtrate obtained in the step S1 through at least one cation exchange column filled with strong acid cation exchange resin, at least one anion exchange column filled with strong alkali anion exchange resin and a mixed bed exchange column filled with mixed ion exchange resin, wherein the operation temperature is maintained at 15-25 ℃, the flow rate is controlled at 4-7 BV/h, and various metal ions and anion impurities are deeply removed; S3, nanofiltration and purification, namely, passing the hydroxylamine aqueous solution subjected to ion exchange through a nanofiltration system, and adopting a polyamide composite membrane with a molecular weight cutoff of more than 150, wherein the operation pressure is 1.0-4.0 MPa, and the temperature is 20-30 ℃ to obtain the hydroxylamine aqueous solution after purification.
  2. 2. The method according to claim 1, wherein the strongly acidic resin is a sulfonic acid group-modified styrene-divinylbenzene copolymer resin having a crosslinking degree of 8 to 12%.
  3. 3. The method according to claim 1, wherein the strongly basic resin is a quaternary ammonium group modified styrene-divinylbenzene copolymer resin having a crosslinking degree of 6 to 10%.
  4. 4. The method of claim 1, wherein the mixed ion exchange resin is comprised of a mixture of a strongly acidic cation exchange resin and a strongly basic anion exchange resin.
  5. 5. The method of claim 4, wherein the volume ratio of cation exchange resin to anion exchange resin in the mixed ion exchange resin is 1:1.5-1:2.0.
  6. 6. The method of claim 1, wherein the nanofiltration system is designed in a two-stage series, the first stage nanofiltration membrane has a molecular weight cut-off of 200-300 Da, and the second stage nanofiltration membrane has a molecular weight cut-off of greater than 150 Da.
  7. 7. The method of claim 1, further comprising the step of adding a stabilizer to the aqueous hydroxylamine solution after S2 ion exchange purification and before S3 nanofiltration purification, the stabilizer being one of hydroxyurea or aminoquinoline.
  8. 8. The method according to claim 7, wherein the stabilizer is added in an amount of 0.01-0.05 wt%.
  9. 9. The method of claim 1, wherein the microfiltration step, ion exchange step and nanofiltration step are all performed under inert gas.
  10. 10. The method according to claim 1, wherein the metal ion content of the finally obtained electronic grade hydroxylamine aqueous solution is lower than 10 ppt, the particle size (more than or equal to 0.1 μm) of the particulate matter is less than 50/mL, and the resistivity is 18.2M Ω & cm.

Description

Method for preparing electronic-grade hydroxylamine aqueous solution Technical Field The invention belongs to the technical field of electronic chemical purification, and particularly relates to a method for preparing an electronic-grade hydroxylamine aqueous solution. Background Hydroxylamine aqueous solution is used as an important electronic chemical and widely applied to key processes such as photoresist removal, wafer cleaning and etching in the manufacturing process of semiconductors and display panels. The hydroxylamine aqueous solution for the electronic industry needs to meet extremely high purity requirements, and generally needs to meet SEMI G3-G5 standards, namely, the metal ion content is lower than 10 ppt-1 ppb, the particulate matter is controlled in a certain range, and the solution resistivity needs to reach more than 18.2M Ω & cm. At present, the preparation method of the electronic grade hydroxylamine aqueous solution mainly comprises an ion exchange method, an electrodialysis method, a distillation method and a double decomposition method. Methods for preparing hydroxylamine aqueous solution by utilizing electrodialysis technology and modified ion exchange membrane are introduced in patents CN117418245A and CN119056256A disclosed by Zhejiang Jinhua new material Co-Ltd, and metal ions are effectively removed by the methods through the special modified ion exchange membrane, so that the purity and stability of the product are improved. However, electrodialysis is relatively large in equipment investment, complex in operation and relatively high in raw material requirements. In addition, CN1648035A proposes a method for preparing high-purity hydroxylamine aqueous solution by combining low-temperature filtration and ion exchange, which can obtain a product with higher purity, but requires low-temperature operation in the process, has higher energy consumption, involves a reduced pressure distillation step, and has a certain safety risk. Technical grade aqueous hydroxylamine solutions typically contain a variety of impurities, including mainly metal ions (e.g., na +、K+、Ca2+、Fe2+、Cu2+, etc.), anions (e.g., cl -、SO42-、NO3-, etc.), particulates, and organic impurities. These impurities have serious effects on the performance of semiconductor devices, and may cause problems such as short circuit, leakage, and reliability degradation. Therefore, there is a need to develop an efficient, economical, safe purification process for purifying aqueous industrial hydroxylamine solutions into electronic grade products. TABLE 1 comparison of the preparation methods of different aqueous hydroxylamine solutions In summary, the existing purification technology has the main problem that various impurities are difficult to comprehensively remove by a single purification method. Disclosure of Invention The invention aims to provide a method for preparing an electronic grade hydroxylamine aqueous solution by taking an industrial grade 50% hydroxylamine aqueous solution as a raw material and adopting a microfiltration, ion exchange and nanofiltration combined technology, which solves the problems of poor purification effect, unstable production process, large potential safety hazard, high production cost and the like in the prior art. In order to achieve the aim, the invention provides the following technical scheme that the method for preparing the electronic-grade hydroxylamine aqueous solution comprises the following steps: s1, microfiltration pretreatment, namely, passing an industrial 50% hydroxylamine aqueous solution through a polyvinylidene fluoride microfiltration membrane with a pore diameter of 0.1-0.2 mu m at a temperature of 15-25 ℃ under an operating pressure of 0.1-0.5 MPa to remove suspended particles and colloid substances; S2, ion exchange purification, namely sequentially passing the filtrate obtained in the step S1 through at least one cation exchange column filled with strong acid cation exchange resin, at least one anion exchange column filled with strong alkali anion exchange resin and a mixed bed exchange column filled with mixed ion exchange resin, wherein the operation temperature is maintained at 15-25 ℃, the flow rate is controlled at 4-7 BV/h, and various metal ions and anion impurities are deeply removed; S3, nanofiltration and purification, namely, passing the hydroxylamine aqueous solution subjected to ion exchange through a nanofiltration system, and adopting a polyamide composite membrane with a molecular weight cutoff of more than 150, wherein the operation pressure is 1.0-4.0 MPa, and the temperature is 20-30 ℃ to obtain the high-purity hydroxylamine aqueous solution. Preferably, the strong acid resin is sulfonic acid group modified styrene-divinylbenzene copolymer resin, and the crosslinking degree is 8-12%. Preferably, the strong alkaline resin is quaternary ammonium group modified styrene-divinylbenzene copolymer resin, and the crosslinking degree is 6-10%. Preferably, the mix