阅读说明：本技术 一种半导体级过氧化氢水溶液的制备方法 (Preparation method of semiconductor-grade hydrogen peroxide aqueous solution ) 是由 白秀君 周继业 汪永超 汤磊硼 朱洁洁 于 2019-09-23 设计创作，主要内容包括：本发明涉及一种半导体级过氧化氢水溶液的制备方法,该方法以工业级过氧化氢为原料,具体包括以下步骤：(1)以工业级过氧化氢水溶液为原料作为反渗透系统的进水,通过已经过膜预处理的一组或多组反渗透系统；(2)获得的产水依次通过已经过转化的1组或多组由阳离子交换树脂、螯合树脂和阴离子交换树脂组成的树脂提纯系统；(3)上步获得的物料通过1组或多组滤芯循环系统过滤,得到目标半导体级过氧化氢水溶液。本发明生产出可用于7nm半导体芯片制造过程中的蚀刻和清洗用的半导体级过氧化氢水溶液,且造成污染小,生产成本较低。(The invention relates to a preparation method of semiconductor grade hydrogen peroxide aqueous solution, which takes industrial grade hydrogen peroxide as a raw material and concretely comprises the following steps: (1) taking industrial-grade hydrogen peroxide aqueous solution as raw material as the inlet water of a reverse osmosis system, and passing through one or more groups of reverse osmosis systems subjected to membrane pretreatment; (2) the obtained produced water passes through 1 or more groups of resin purification systems consisting of cation exchange resin, chelating resin and anion exchange resin which are converted in sequence; (3) and filtering the obtained material by 1 or more groups of filter element circulating systems to obtain the target semiconductor grade hydrogen peroxide water solution. The invention can produce semiconductor grade hydrogen peroxide aqueous solution for etching and cleaning in the manufacturing process of 7nm semiconductor chips, and has the advantages of little pollution and low production cost.)

1. A preparation method of semiconductor grade aqueous hydrogen peroxide is characterized in that the semiconductor grade aqueous hydrogen peroxide is prepared by purifying through a method of combining a reverse osmosis system, a resin purification system and a filter element circulating system.

2. The method according to claim 1, characterized in that it comprises in particular the steps of:

(1) Taking industrial-grade hydrogen peroxide aqueous solution as raw material as the inlet water of a reverse osmosis system, and passing through one or more groups of reverse osmosis systems subjected to membrane pretreatment;

(2) The produced water obtained in the step (1) passes through one or more groups of resin purification systems consisting of cation exchange resin, chelating resin and anion exchange resin which are converted in sequence;

(3) And (3) filtering the material obtained in the step (2) by one or more groups of filter element circulating systems to obtain the target semiconductor grade hydrogen peroxide water solution.

3. The method of claim 2, wherein the reverse osmosis system membrane pretreatment in step (1) comprises: sequentially taking an alkali solution, pure water, an acid solution and pure water as inflow water, wherein the operation time of each step is 1-5h, preferably 2-3h, and the inflow water flow rate of a single reverse osmosis membrane is 0.3-1m for carrying out the cultivation/h; wherein the alkali solution comprises a sodium hydroxide solution, a potassium hydroxide solution or ammonia water, and the acid solution comprises a nitric acid solution, an acetic acid solution or a citric acid solution; the contents of the acid solution and the alkali solution are 1-5%, preferably 3-5%, and the purities of the two solutions are not lower than analytical purity, preferably superior purity.

4. The method of claim 2, wherein the conditions for the introduction of the industrial-grade aqueous hydrogen peroxide solution into the reverse osmosis system in step (1) are: carrying out industrial-grade hydrogen peroxide aqueous solution at the temperature of 0-25 ℃ and carrying out thin film distillation on a single reverse osmosis membrane at the inflow water flow rate of 0.3-1 m/h, preferably 0.5-0.1 m; the content of the industrial-grade hydrogen peroxide for water inflow is adjusted to 27.5% -70%, preferably 30% -50%, wherein the industrial-grade aqueous hydrogen peroxide solution is: aqueous hydrogen peroxide solution produced by the anthraquinone process without impurity removal.

5. The method of claim 2, characterized in that each set of reverse osmosis membrane systems in step (1): is composed of more than one kind of membrane or mixture of several kinds of membranes, the kinds of membrane include polyamide membrane, polyester membrane, cellulose acetate membrane and polysulfone membrane, and the pore diameter of the membrane is 0.1-10 nm.

6. The method according to claim 2, wherein the resin purification system conditions in step (2) are: the water produced by the reverse osmosis system sequentially passes through one or more groups of resin purification systems at the flow rate of 3-30 times of the volume of the resin per hour, and is filtered by one or more groups of filter element circulating systems, and the water produced by the reverse osmosis system is controlled to be at the temperature of 0-25 ℃ and enters the resin purification systems.

7. The method according to claim 2, wherein said step (2) comprises, for each group of resin purification systems: the cation exchange resin, the chelating resin and the anion exchange resin are randomly combined, wherein the cation exchange resin is styrene cation exchange resin or strong acid cation exchange resin, the chelating resin is macroporous polystyrene special-effect coordination adsorption resin, and the anion exchange resin is styrene anion exchange resin or strong base anion exchange resin.

8. the method according to claim 2, wherein during the conversion of the resin purification system in step (2): the conversion reagent is acid solution or alkali solution, wherein cation exchange resin adopts acid solution conversion, and chelate resin and anion exchange resin adopt alkali solution conversion, and the specific conversion method comprises the following steps:

（) Inputting a conversion medicament which is 3-20 times of the volume of the resin column to be converted into the resin column and enabling the conversion medicament to flow through the resin column in a single direction for treatment; then 3-20 times of transforming agent is input and flows through the resin column in one way for processing; then inputting ultrapure water and enabling the ultrapure water to continuously flow through the resin column in the same direction to clean the resin column for 2-10h, wherein the flow directions of the conversion reagent and the ultrapure water in the step are the same;

（) Introducing a transforming agent in an amount of 3 to 20 times the volume of the resin column to be transformed into a product) Treating the treated resin column by allowing the treated resin column to flow through the resin column in a single direction; then 3-20 times of transforming agent is input and flows through the resin column in one way for processing; then inputting ultrapure water and making it continuously flow through the resin column in the same direction to clean the resin column for 2-10h, wherein the flow directions of the conversion reagent and the ultrapure water in the step are both the same as that in the step (a)) On the contrary;

Step (a)) Step (1)) Repeating the operation for 2-10 times, preferably 3-5 times, to complete the transformation process; the acid solution comprises hydrochloric acid solution, nitric acid solution or sulfuric acid solution, and the alkali solution comprises sodium hydroxide solution, potassium hydroxide solution or ammonia water; the contents of the acid solution and the alkali solution are 3-20%, preferably 5-15%, and the purity is not lower than that of the superior grade.

9. The method of claim 2, wherein the filter cartridge recycling system of step (3) is: comprises one or more groups of filter elements with the diameter of 0.5 μm, 0.2 μm and 0.1 μm.

10. The method of claim 2 wherein the reverse osmosis system is made of stainless steel and the equipment other than the reverse osmosis system that is in contact with the aqueous solution of hydrogen peroxide is made of fluoroplastic.

Technical Field

The present invention relates to a method for preparing a semiconductor grade aqueous hydrogen peroxide solution, and more particularly, to a method for preparing a semiconductor grade aqueous hydrogen peroxide solution used for etching and cleaning in a 7nm semiconductor chip manufacturing process.

Background

The semiconductor grade hydrogen peroxide water solution is an ultra-clean high-purity electronic chemical for semiconductors, is mainly used for processes of oxidation, cleaning and the like of silicon wafers, and has very important influence on the finished product rate, the electrical property, the reliability and the like due to the purity and the cleanliness.

The preparation method of the semiconductor grade aqueous hydrogen peroxide solution is a process of taking low-quality industrial grade aqueous hydrogen peroxide solution as a raw material, removing impurities in industrial grade hydrogen peroxide products, and purifying to prepare high-quality semiconductor grade aqueous hydrogen peroxide solution. The removal of organic impurities is particularly important in the purification process, and the excessive organic impurities in the hydrogen peroxide not only affect the effect of removing anions and cations by the ion exchange resin, but also contaminate the circuit board in the etching and cleaning processes, so that the conductivity of the circuit board is reduced and even the circuit is broken.

The existing preparation method of semiconductor grade hydrogen peroxide aqueous solution has some defects, such as high production cost and fussy process route, for example: in the method for removing organic impurities by combining at least one group of series-connected macroporous adsorption resin columns with different polarities and apertures, the adsorption resin has limit on removing the organic impurities, the converted medicament can cause pollution, hydrogen peroxide can react with the organic matters to generate superoxide organic matters in the purification process, potential safety hazards exist, and the sewage of the regenerated medicament waste liquid is difficult to treat.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a preparation method of semiconductor-grade aqueous hydrogen peroxide, which adopts a plurality of groups of reverse osmosis systems to be combined with a resin purification system and a filter element circulating system, so that organic impurities in the aqueous hydrogen peroxide can be easily removed to be below 2ppm.

The specific technical scheme comprises the following steps:

The preparation method of the semiconductor grade aqueous hydrogen peroxide is characterized in that the semiconductor grade aqueous hydrogen peroxide is prepared by purifying through a method of combining a reverse osmosis system, a resin purification system and a filter element circulating system.

The method is characterized by comprising the following steps:

(1) Taking industrial-grade hydrogen peroxide aqueous solution as raw material as the inlet water of a reverse osmosis system, and passing through one or more groups of reverse osmosis systems subjected to membrane pretreatment;

(2) The produced water obtained in the step (1) passes through one or more groups of resin purification systems consisting of cation exchange resin, chelating resin and anion exchange resin which are converted in sequence;

(3) And (3) filtering the material obtained in the step (2) by one or more groups of filter element circulating systems to obtain the target semiconductor grade hydrogen peroxide water solution.

The method is characterized in that the reverse osmosis system membrane pretreatment method in the step (1) comprises the following steps: sequentially taking an alkali solution, pure water, an acid solution and pure water as inflow water, wherein the operation time of each step is 1-5h, preferably 2-3h, and the inflow water flow rate of a single reverse osmosis membrane is 0.3-1m for carrying out the cultivation/h; wherein the alkali solution comprises a sodium hydroxide solution, a potassium hydroxide solution or ammonia water, and the acid solution comprises a nitric acid solution, an acetic acid solution or a citric acid solution; the contents of the acid solution and the alkali solution are 1-5%, preferably 3-5%, and the purities of the two solutions are not lower than analytical purity, preferably superior purity.

The method is characterized in that the conditions for feeding the industrial-grade aqueous hydrogen peroxide solution into the reverse osmosis system in the step (1) are as follows: carrying out industrial-grade hydrogen peroxide aqueous solution at the temperature of 0-25 ℃ and carrying out thin film distillation on a single reverse osmosis membrane at the inflow water flow rate of 0.3-1 m/h, preferably 0.5-0.1 m; the content of the industrial-grade hydrogen peroxide for water inflow is adjusted to 27.5% -70%, preferably 30% -50%, wherein the industrial-grade aqueous hydrogen peroxide solution is: aqueous hydrogen peroxide solution produced by the anthraquinone process without impurity removal.

The method is characterized in that each set of reverse osmosis membrane systems in the step (1): is composed of more than one kind of membrane or mixture of several kinds of membranes, the kinds of membrane include polyamide membrane, polyester membrane, cellulose acetate membrane and polysulfone membrane, and the pore diameter of the membrane is 0.1-10 nm.

The method is characterized in that the resin purification system conditions in the step (2) are as follows: the water produced by the reverse osmosis system sequentially passes through one or more groups of resin purification systems at the flow rate of 3-30 times of the volume of the resin per hour, and is filtered by one or more groups of filter element circulating systems, and the water produced by the reverse osmosis system is controlled to be at the temperature of 0-25 ℃ and enters the resin purification systems.

The method is characterized in that in each group of resin purification systems in the step (2): the cation exchange resin, the chelating resin and the anion exchange resin are randomly combined, wherein the cation exchange resin is styrene cation exchange resin or strong acid cation exchange resin, the chelating resin is macroporous polystyrene special-effect coordination adsorption resin, and the anion exchange resin is styrene anion exchange resin or strong base anion exchange resin.

the method is characterized in that in the conversion process of the resin purification system in the step (2): the conversion reagent is acid solution or alkali solution, wherein cation exchange resin adopts acid solution conversion, and chelate resin and anion exchange resin adopt alkali solution conversion, and the specific conversion method comprises the following steps:

（) Inputting a conversion medicament which is 3-20 times of the volume of the resin column to be converted into the resin column and enabling the conversion medicament to flow through the resin column in a single direction for treatment; then 3-20 times of transforming agent is input and flows through the resin column in one way for processing; then inputting ultrapure water and enabling the ultrapure water to continuously flow through the resin column in the same direction to clean the resin column for 2-10h, wherein the flow directions of the conversion reagent and the ultrapure water in the step are the same;

（) Introducing a transforming agent in an amount of 3 to 20 times the volume of the resin column to be transformed into a product) Treating the treated resin column by allowing the treated resin column to flow through the resin column in a single direction; then 3-20 times of transforming agent is input and flows through the resin column in one way for processing; then inputting ultrapure water and making it continuously flow through the resin column in the same direction to clean the resin column for 2-10h, wherein the flow directions of the conversion reagent and the ultrapure water in the step are both the same as that in the step (a)) On the contrary;

Step (a)) Step (1)) Repeating the operation for 2-10 times, preferably 3-5 times, to complete the transformation process; the acid solution comprises hydrochloric acid solution, nitric acid solution or sulfuric acid solution, and the alkali solution comprises sodium hydroxide solution, potassium hydroxide solution or ammonia water; the contents of the acid solution and the alkali solution are 3-20%, preferably 5-15%, and the purity is not lower than that of the superior grade.

The method is characterized in that the filter element circulating system in the step (3) is as follows: comprises one or more groups of filter elements with the diameter of 0.5 μm, 0.2 μm and 0.1 μm.

The method is characterized in that the materials of the reverse osmosis system which are contacted with the aqueous hydrogen peroxide solution are all stainless steel, and the materials of the equipment which is not contacted with the aqueous hydrogen peroxide solution in the reverse osmosis system are all fluoroplastic.

the semiconductor Grade hydrogen peroxide aqueous solution prepared by the preparation method is suitable for etching and cleaning in the manufacturing process of 7nm semiconductor chips, and has the organic matter content of not more than 2ppm, the single metal impurity content of not more than 5ppt, the single anion impurity content of not more than 30ppb and is far lower than the requirement of the highest Grade5 in the SEMI C30-0218 standard. The reverse osmosis membrane is a physical process for removing organic impurities, does not relate to chemical drugs, and solves the problems of product pollution caused by a regeneration medicament in the purification operation, safety accidents caused by the reaction of the regeneration medicament and hydrogen peroxide and the burden of waste liquor of the regeneration medicament on sewage treatment. In addition, the process route of the invention is simple, no special device or material is needed, the equipment investment is small, and the production cost is low.

Detailed description of the invention

the invention is further illustrated by the following specific examples.

[ reverse osmosis membrane treatment ]

(1) The pretreatment method of the reverse osmosis system comprises the following steps:

pretreating the reverse osmosis membrane by adopting a repeated method for multiple times, preferably 1-5 times: taking the alkali solution as inflow water, carrying out the high-speed cultivation on a single reverse osmosis membrane at the inflow water flow rate of 0.3-1 m/h, preferably 0.3-0.5 m/h, and carrying out the high-speed cultivation for 1-5h, preferably 2-3 h; then taking ultrapure water as inflow water, carrying out the high-speed cultivation on the single reverse osmosis membrane at the inflow water flow rate of 0.3-1 m/h, preferably 0.3-0.5 m/h, and carrying out the high-speed cultivation for 1-5h, preferably 2-3 h; then, taking the acid solution as inflow water, carrying out the cultivation on the single reverse osmosis membrane at the inflow water flow rate of 0.3-1 m/h, preferably 0.3-0.5 m/h, and carrying out the cultivation for 1-5h, preferably 2-3 h; and finally, taking the ultrapure water as inflow water, and carrying out the high pressure distillation on the single reverse osmosis membrane at the inflow water flow rate of 0.3-1 m/h, preferably 0.3-0.5 m/h, and carrying out the high pressure distillation for 1-5h, preferably 2-3 h.

wherein, the reverse osmosis membrane is pretreated by adopting aqueous solution of alkali and acid as pretreatment agent, and is cleaned by ultrapure water after the pretreatment is finished. Wherein the alkali solution comprises sodium hydroxide solution, potassium hydroxide solution or ammonia water, and the content of the alkali solution is 1-5%, preferably 3-5%; the acid solution comprises nitric acid solution, acetic acid solution or citric acid solution, and the content of the acid solution is 1-5%, preferably 3-5%; the purity of both solutions must not be lower than analytical purity, preferably premium grade.

Wherein the reverse osmosis membrane system consists of one or more groups of reverse osmosis membranes, and each group of reverse osmosis membranes consists of one or more reverse osmosis membranes. The reverse osmosis membrane comprises polyamide membrane, polyester membrane, cellulose acetate membrane, polysulfone membrane, etc., preferably polyamide membrane and cellulose acetate membrane, and preferably has a membrane pore diameter of 0.1-10 nm.

(2) The method for treating the industrial-grade aqueous hydrogen peroxide solution by the reverse osmosis system comprises the following steps:

The industrial-grade aqueous hydrogen peroxide solution is: hydrogen peroxide solution produced by anthraquinone process without impurity removal; the content of the water inlet industrial grade hydrogen peroxide is adjusted to 27.5 to 70 percent, preferably 30 to 50 percent; carrying out thin film cultivation on a single reverse osmosis membrane at the inflow flow rate of 0.3-1 m/h, preferably 0.5-0.1m, and carrying out one or more groups of reverse osmosis systems, preferably 2-5 groups of reverse osmosis systems.

[ resin treatment ]

the industrial grade hydrogen peroxide solution treated by the reverse osmosis system is continuously treated by a resin purification system consisting of cation exchange resin, chelate exchange resin and anion exchange resin.

(1) The resin pretreatment method comprises the following steps:

The method is repeated for multiple times, preferably 3-5 times, namely, the regenerant aqueous solution with the volume of the regenerated resin being a certain multiple, preferably 3-20 times, flows through the lipid column from top to bottom; then ultrapure water with a certain multiple of the volume of the resin is input into the resin column, and the resin column is cleaned by flowing from top to bottom for 2 to 10 hours, preferably 5 to 10 hours; then, a regenerant aqueous solution with the volume 3-20 times of the volume of the regenerated resin flows through the resin column from bottom to top; then ultrapure water with a certain volume multiple of the regenerated resin passes through the resin column from bottom to top for flow cleaning for 2-10h, preferably 5-10h, and the resin is treated. In the present invention, it is preferable to repeat the cycle of regenerant flow/ultrapure water cleaning 2 times or more. By repeating the flow of the regenerant/ultrapure water, the resin is caused to contract and expand, the exchange resin can be regenerated efficiently and uniformly, and the inside of the resin can be cleaned.

Wherein the cation exchange resin used in the present invention is H⁺Type cation exchange resins are resins commonly referred to as strong acid cation exchange resins. In general, the strongly acidic cation exchange resin preferably has a network structure in which a sulfonic acid group is introduced into a styrene-divinylbenzene crosslinked copolymer. The anion exchange resin is styrene anion exchange resin or strong base anion exchange resin; the chelating resin is macroporous polystyrene adsorption resin.

Wherein the cation exchange resin is regenerated using an inorganic acid, preferably sulfuric acid, hydrochloric acid and nitric acid; the anion exchange resin and the chelating resin are regenerated by using strong base, and the strong base is preferably sodium hydroxide, potassium hydroxide or ammonia water. The concentration of the regenerant aqueous solution is 3-20%, preferably 5-15%.

Wherein the regenerant should be 1-3 Hr^-1SV of (1) and a BV of 1-2L/L-R are flowed through the resin, and then ultrapure water is flowed at 5-20Hr^-1And a BV of 0.1-0.5L/L-R, flowed through the resin for cleaning. Finally, ultrapure water cleaning is repeatedFurther washing the regenerated resin, including downward flow and upward flow, 5-10 times. Preferably, the ultrapure water is used at 5 to 20Hr^-1and SV of 3-5L/L-R and BV of 3-5L/L-R.

(2) The method for treating reverse osmosis produced water by the resin purification system comprises the following steps:

Reverse osmosis producing water with 10-30 Hr^-1Preferably 20-30 Hr^-1SV (1) passes through each resin layer. The ionic impurities in the aqueous hydrogen peroxide solution can be removed by treatment with a resin purification system as described above.

Through the operation, the semiconductor Grade hydrogen peroxide aqueous solution can be prepared, wherein the content of the removed organic impurities and ionic impurities reaches or is far lower than the requirement of the highest Grade5 in the C30-0218 standard. Also, the aqueous hydrogen peroxide solution purified by the present invention has good and stable reproducibility in the degree of removing both organic impurities and ionic impurities. In addition, it is also possible to adjust the hydrogen peroxide content by adding ultrapure water (preferably ultrapure water with high impurity removal) to the aqueous hydrogen peroxide solution obtained by the method provided by the present invention.

the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. The organic matter impurity content of the obtained hydrogen peroxide aqueous solution is detected by a TOC analyzer, positive ions are analyzed by ICP-MS, negative ions are analyzed by ion chromatography, and dust particles are measured by a laser counter.