JPH07187616A - Production of hydrogen peroxide solution of high purity - Google Patents

Abstract

PURPOSE:To obtain a hydrogen peroxide solution of high purity which is optimal for a semiconductor producing proceess and in which metals, chloride ions and sulfurate radicals have been reduced by bringing crude hydrogen peroxide solution into contact with a specified ion exchange resin. CONSTITUTION:A crude hydrogen peroxide solution of 20-30wt.% industrially produced by an anthraquinone method and having purity higher than the industrial one so called that used for electronic industry, etc., is brough into contact with an anion exchang resin and/or a cation exchange resin in multiple stages, and is brought into contact with a cation exchange resin of <=5 degree of cross- linking in a final stage. The cation exchange resin is used as a hydrogen type. That is, after a column is filled with the cation exchange resin and mineral acid is passed through the resin to turn in into the hydrogen type, it is washed with water to remove excess mineral acid, the washed resin is used. The anion exchange resin is fed as a chlorine type or a hydroxyl type. That is, a column is filled with the and resin ammonium carbonate or ammonium bicarbonate is passed through the resin, and the resin thus obtained is used. Crude hydrogen peroxide solution is passed through the column filled with the anion and/or cation exchange resin to collect impurities.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing high-purity hydrogen peroxide water used in a semiconductor or other semiconductor manufacturing process.

[0002]

2. Description of the Related Art In recent years, with the high integration of LSIs, the demand for cleaner materials used in semiconductor manufacturing processes has become more severe. Dust and metals that adhere to wafers affect the reliability of semiconductors and reduce yield, so it is extremely important to suppress these adhesions as much as possible in order to industrially manufacture semiconductors. There is.

Hydrogen peroxide water is used as a mixture with ammonia water, hydrochloric acid, sulfuric acid or hydrofluoric acid in a wafer cleaning step in a semiconductor manufacturing process such as LSI. It is said that when hydrogen peroxide water is mixed with hydrochloric acid, sulfuric acid or hydrofluoric acid, no metal adheres to the wafer from the cleaning solution, but it is used as a mixture with ammonia water for the purpose of removing particles. It is sometimes reported that metals such as iron and aluminum adhere to the wafer surface from the cleaning solution. In addition, it is becoming clear that the presence of chlorine ions and sulfate ions adversely affects metal adhesion, and there is a demand for hydrogen peroxide water in which these anions are reduced.

It is known that the high-purity hydrogen peroxide solution used in the conventional semiconductor manufacturing process is manufactured mainly by a method of contacting with an ion exchange resin. As an example thereof, USP 2,676,923 discloses a method of removing metals by contacting a sulfonated cation exchange resin with a nucleus and a crude hydrogen peroxide solution. JP 62-
Japanese Patent No. 187103 describes the combined use of a pyridine-based anion exchange resin and a cation exchange resin. At this time, by contacting with a cation exchange resin and then with an anion exchange resin, an increase in sulfate radicals is not caused and hydrogen peroxide is increased. It is said that water can be highly purified.

However, in these known methods, it is possible to considerably reduce carboxylic acids and chloride ions by the liquid passing method, but it is not possible to simultaneously reduce metals and sulfate radicals.

That is, the metals present as cations can be reduced only by contacting the crude hydrogen peroxide solution with the conventionally used cation exchange resin, but the anions and anionic metals cannot be removed. Furthermore, when the anion exchange resin and the cation exchange resin are used in contact with crude hydrogen peroxide,
Finally, when the cation exchange resin is brought into contact with the cation exchange resin, the metals can be reduced well, but in the sulfonic acid type strongly acidic cation exchange resin having a good ability to reduce the metals, the sulfate radicals increase. On the other hand, when it is finally brought into contact with the anion exchange resin, the sulfate group can be reduced well, but the reduction of metals or chloride ion becomes insufficient. This is because when a chlorine type anion exchange resin is used, chlorine ions ion-exchanged with anionic metals and sulfates are mixed in hydrogen peroxide water, and anions regenerated with sodium bicarbonate in Japanese Patent Publication No. 35-116677. This is because sodium is eluted from the anion exchange resin when the exchange resin is brought into contact with the crude hydrogen peroxide solution even if it is sufficiently washed with water after regeneration.

[0007]

In view of the above situation, an object of the present invention is to provide a highly pure hydrogen peroxide solution in which metals, chloride ions and sulfates are reduced, and therefore, it is optimally used in a semiconductor manufacturing process. It exists in providing the method of manufacturing the high purity hydrogen peroxide solution.

[0008]

Means for Solving the Problems The present inventors have completed the present invention as a result of intensive studies on purification of crude hydrogen peroxide solution using an ion exchange resin in order to solve the above problems.

That is, according to the present invention, in purifying crude hydrogen peroxide solution to produce high purity hydrogen peroxide solution, the crude hydrogen peroxide solution is contacted with a strongly acidic cation exchange resin having a degree of crosslinking of 5 or less. The present invention relates to a method for producing high-purity hydrogen peroxide water, which is characterized in that

As the crude hydrogen peroxide solution, hydrogen peroxide solution produced by the industrially produced anthraquinone method or the like can be used. Further, it is possible to use hydrogen peroxide water having a higher purity than that for industrial use, which is referred to as for electronic industries.
Its concentration is 20-30% by weight for semiconductor manufacturing process
Since it is used, it may be 20% by weight or more, but if the hydrogen peroxide solution having a too high concentration is brought into contact with the ion exchange resin, the deterioration of the ion exchange resin is accelerated,
Since the elution of impurities from the ion exchange resin may occur, it is preferably used in an amount of 20% by weight to 40% by weight. When used at a lower concentration in the semiconductor manufacturing process, a hydrogen peroxide solution having a concentration corresponding thereto can be used as a raw material.

In order to sufficiently reduce the anions and metals, the crude hydrogen peroxide solution is preferably contacted with both the anion exchange resin and the cation exchange resin. The resin may be contacted in one step or in multiple steps.
However, it is preferable to use a cation exchange resin at the end of the treatment in order to solve the above-mentioned problems.

The cation exchange resin used in the present invention is a strongly acidic cation exchange resin having a degree of crosslinking of 5 or less, preferably 4 or less. If the degree of cross-linking is excessive, the concentration of sulfate radicals in hydrogen peroxide water will increase. The degree of crosslinking means the weight% of divinylbenzene in the exchange resin.

The cation exchange resin of the present invention is used in the hydrogen form. What is supplied as the sodium form is converted to the hydrogen form by a mineral acid such as hydrochloric acid or sulfuric acid. There is also a conversion method that uses a tank or a reactor and suspends the cation exchange resin in an aqueous solution of a mineral acid such as hydrochloric acid or sulfuric acid. It is generally industrially done. That is, 0.1 to 2
The flow rate of the superficial flow (hereinafter abbreviated as SV) is 0.5 to 20 hr ⁻¹ using N mineral acid. The amount of liquid to be passed is such that the equivalent ratio of the acid to the functional group is double or more.
After conversion to the hydrogen form, the cation exchange resin is washed with water to remove excess mineral acid.

In order to regenerate the used cation exchange resin, the aqueous solution of the mineral acid may be passed through in the same manner as converting the new resin into the hydrogen form.

As the anion exchange resin, either a strong base type or a weak base type may be used.

The anion exchange resin is usually supplied as a chlorine type or a hydroxide type. In the chlorine type, there is a problem that chlorine ions are mixed in the generated hydrogen peroxide solution, and in the hydroxyl type, significant decomposition of hydrogen peroxide occurs.Therefore, when using a new anion exchange resin for conditioning, the carbonate type or Convert to bicarbonate form. As a conversion method, it is industrially preferable to perform column conversion as in the case of the cation exchange resin. That is, 0.1 to 1.2 N ammonium carbonate or ammonium bicarbonate aqueous solution is used so that the equivalent ratio to the functional group is more than twice, and SV = 0.1 to 20 hr ⁻¹ ,
The liquid may be passed through a column packed with an anion exchange resin.

It is preferable that what is supplied as a chlorine type can be converted into a hydroxide type once and then a carbonate type or a bicarbonate type, which is more preferable because it can be converted more completely. To make it into the hydroxide form, conversion is carried out using an alkaline aqueous solution such as sodium hydroxide, potassium hydroxide or aqueous ammonia. After conversion to the carbonate type or bicarbonate type by the method described above, excess ammonium carbonate or ammonium bicarbonate is removed by washing with water.

In order to regenerate the used anion exchange resin, an aqueous solution of ammonium carbonate or ammonium bicarbonate may be passed in the same manner as in the case of converting the new resin into a carbonate type or a bicarbonate type.

It should be noted that repeating the usual acid and alkali passages during conditioning does not cause any problems in the practice of the present invention.

By the above-described method, the carbonate type or bicarbonate type anion exchange resin and the hydrogen type cation exchange resin are brought into contact with the crude hydrogen peroxide solution. The contacting method may be a batch method in which an anion exchange resin and / or a cation exchange resin converted into a desired form are placed in hydrogen peroxide water and stirred, but the anion exchange resin or the cation exchange resin is filled. A method of passing hydrogen peroxide solution through the prepared column is industrially preferable.

The height of packing of the anion exchange resin and / or the cation exchange resin in the column may be 20 cm or more in order to prevent leakage of metals and anions.
More preferably, it is at least cm. The liquid passing speed is SV of 0.
It is ¹ to 20 hr ^-1 , but 0.5 to 10 is more preferable.

The temperature at the time of contact between the crude hydrogen peroxide solution and the cation exchange resin is preferably -10 to 30 ° C,
It is more preferable to carry out at -10 to 10 ° C.

According to the method described above, highly pure hydrogen peroxide water having a low metal and a low anion concentration, which is preferable for semiconductor production, can be obtained.

[0024]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples. Example-1 Diaion SA10 which is a strongly basic anion exchange resin
A (Quaternary ammonium type 1, trade name of Mitsubishi Kasei Co., Ltd.) was packed in a column with a bed height of 30 cm, and as conditioning, an amount equivalent to 5 times the functional groups of 1N sodium hydroxide was passed at SV = 5 hr ⁻¹ . The solution was drained and then washed with ultrapure water in an amount 5 times the amount of the resin. Next, an amount equivalent to 5 times the functional groups of 1N hydrochloric acid was passed through with SV = 5 hr ^-1 , and then washed with ultrapure water in an amount 5 times the amount of the resin. Further 1N sodium hydroxide - ultrapure water -1N hydrochloric - ultrapure water in liquid permeability of the After repeated twice as described above, the amount of SV = 5 hr become 5 equivalents again functional groups 1N sodium hydroxide ^{- The} solution was passed through ¹ and then washed with 5 times the resin amount of ultrapure water to convert the anion exchange resin to the hydroxide type. Next, 5 of the functional groups of 1N ammonium bicarbonate
The anion-exchange resin was converted to a bicarbonate type by passing an amount equivalent to a double equivalent at SV = 5 hr ⁻¹ and finally washing by passing an amount of ultrapure water 10 times the amount of the resin. Another column is cross-linked with divinylbenzene and the degree of cross-linking is 4
And strong acid cation exchange resin, DIAION SK10
4 (trade name of Mitsubishi Kasei Co., Ltd.) with a bed height of 30 cm, and 1N hydrochloric acid corresponding to 5 times equivalent of the functional group-ultra pure water of 5 times the amount of resin-1N equivalent to 5 times equivalent of the functional group. Sodium hydroxide-5 times the amount of the resin passed by ultrapure water was repeated 3 times, and 1N hydrochloric acid corresponding to 5 times the equivalent of the functional group was added to SV =
The solution was passed at 5 hr ⁻¹ and finally washed with water by passing an amount of ultrapure water 10 times the amount of the resin to convert the cation exchange resin into a hydrogen type. Metals as raw materials are 0. Number to 10 pp
b, 31% crude hydrogen peroxide water containing several 10 ppb of sulfate radicals and chloride ions is used, and the hydrogen peroxide water is anion exchange resin column and cation exchange resin column in that order at 7 ° C., SV =
The solution was passed for 4 hr ^-1 .

The hydrogen peroxide solution flowing out from the column was collected, and the metals, chloride ions and sulfates contained in this solution were analyzed. Metals such as Na, Ca, Al, and Fe are all 0.1 ppb or less, and chloride ion and sulfate group are 10 p
It was not more than pb and was very high in purity.

The metals were analyzed by the ICP-MS method and the flameless atomic absorption method, and the chloride ion and the sulfate group were analyzed by the ion chromatography method.

Example-2 Conditioning was carried out in the same manner as in Example-1 using Diaion SA20A (Quaternary ammonium type 2, trade name of Mitsubishi Kasei Co., Ltd.) which is a strongly basic anion exchange resin as the anion exchange resin. . Example of cation exchange resin-
Conditioned SK104 as in 1.
Was used. Two columns of each resin were prepared and connected in the order of anion-cation-anion-cation.
Industrial grade hydrogen peroxide solution was added to this column at 6 ℃ and SV
= 5 hr −1. In this crude hydrogen peroxide solution, several thousand ppb of Na and several tens of Al, Ca and Fe are contained.
Several hundred ppb was contained, and chlorine ion and sulfate were also contained in several hundred ppb. Metal ions in hydrogen peroxide water flowing out through the four columns are Na, Al, F
e, Ca, etc. were all 0.1 ppb or less, and chloride ion and sulfate group were also 10 ppb or less.

Comparative Example-1 Example 1 was repeated except that DIAION SK1B (trade name of Mitsubishi Kasei Co., Ltd.), which is a strongly acidic cation exchange resin having a degree of crosslinking of 8 and crosslinked with divinylbenzene, was used as the cation exchange resin. The same crude hydrogen peroxide solution as that used in Example-1 was passed in the same manner as in. The metals in the effluent are all 0.1 ppb or less, and the chlorine ions are 10 pp
Although it was less than b, the sulfate group was as high as 45 ppb.

[0029]

Industrial Applicability As described above, according to the present invention, a high-purity hydrogen peroxide solution with reduced metals, chloride ions, and sulfate radicals, which is optimally used in a semiconductor manufacturing process, can be obtained. A method for producing water could be provided.

Claims (1)

[Claims] 1. A method of purifying crude hydrogen peroxide solution to produce high-purity hydrogen peroxide solution, which comprises contacting the crude hydrogen peroxide solution with a strongly acidic cation exchange resin having a degree of crosslinking of 5 or less. And a method for producing high-purity hydrogen peroxide water.