Method for treating development waste liquid

A treatment method and developing solution technology, applied in heating water/sewage treatment, electrochemical water/sewage treatment, photography, etc., can solve problems such as obstacles to long-term stable operation, low purity of TAA hydroxide aqueous solution, and rise in electrolyzer voltage , to achieve the effect of safe and effective disposal

Inactive Publication Date: 2008-01-23
TOKUYAMA CORP
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Problems solved by technology

[0005] However, the method of the above-mentioned Patent Document 1 cannot be applied to the development step for forming a precise fine wiring layer, etc., and is only applicable to Development steps without precision requirements
And when it is applied to the developing step that requires precision, the waste developing liquid is not recycled, but only recycled in the developing step that does not require precision
[0006] In addition, in the case of refining treatment such as Patent Document 2, sufficient purity cannot be recovered even

Method used

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Examples

Experimental program
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Embodiment 1

[0076] Using the thin-film concentrator 3, the liquid containing the photoresist and the tetramethylammonium hydroxide (TMAH) solution discharged from the developing step 1 of the liquid crystal display (LCD) factory was concentrated at a liquid temperature of 60° C. under a reduced pressure of 20 kPa. The waste liquid 2 was developed to obtain a brown concentrated liquid (1).

[0077] The various components of the obtained concentrate (1) were analyzed, and the results are shown below.

[0078] TMAH concentration: 20.6wt%

[0079] Concentration of metal impurities:

[0080] Al: 3800ppb (unit TAA is 22.7ppm)

[0081] Na: 40ppb (unit TAA is 0.24ppm)

[0082] Cu: 650ppb (unit TAA is 3.88ppm)

[0083] Fe: 800ppb (unit TAA is 4.78ppm)

[0084] The total content of unit TAA: 31.60ppm

[0085] Total concentration of organic impurities: 3800ppm

[0086] The TMAH concentration was measured by potentiometric titration, the metal concentration was measured by ICP-MS, and the tota...

Embodiment 2

[0128] The concentrate (2) of Comparative Example 1 was diluted by adding a high-purity TMAH aqueous solution. The analysis results of the high-purity TMAH aqueous solution and diluent used are as follows.

[0129] High-purity TMAH aqueous solution

[0130] TMAH concentration: 20.1wt%

[0131] Al: less than 5ppb

[0132] Na: less than 5ppb

[0133] Cu: below 5ppb

[0134] Fe: below 5ppb

[0135] Total concentration of organic impurities: below 10ppm

[0136] Diluent

[0137] TMAH concentration: 20.3wt%

[0138] Al: 6000ppb (unit TAA is 36.3ppm)

[0139] Na: 60ppb (unit TAA is 0.36ppm)

[0140] Cu: 2100ppb (unit TAA is 12.7ppm)

[0141] Fe: 1500ppb (unit TAA is 9.01ppm)

[0142] The total content of unit TAA: 58.37ppm

[0143] Total concentration of organic impurities: 3800ppm

[0144] The content of each metal impurity in this diluted solution is below the reference value (50 ppm) of the present invention.

[0145] Using this diluted solution, neutralization, sep...

Embodiment 3

[0156] The concentrated solution (2) (developing waste solution) of Comparative Example 1 was supplied in the form of droplets or mist at the positions shown in Table 1 in the cement manufacturing process (while giving the temperature). In addition, the input amount of developing waste liquid is 10g / Nm relative to the gas flow rate at the input position. 3 Continuous supply from left to right.

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Abstract

This invention provides a method for treating a development waste liquid comprises selecting one of the step of determining the concentration of a tetraalkylammonium (TAA) and the content of metal impurities in a development waste liquid containing an aqueous tetraalkylammonium hydroxide solution and purifying the development waste liquid depending upon the determined metal impurity content per TAA to generate an aqueous TAA hydroxide solution used as the developing solution, the step of disposing of the development waste liquid, and the step of diluting the development waste liquid with an aqueous TAA hydroxide solution unused as the developing solution and then purifying the diluted development waste liquid to generate the aqueous TAA hydroxide solution used as the developing solution. This method is characterized in that the metal impurity content per TAA as the standard of selection in each step is set to 50 ppm. According to this method, a development waste liquid containing TAA hydroxide discharged from a photoresist development step can be stably purified over a long period of time, and, consequently, a high-purity aqueous TAA hydroxide solution reusable as a developing solution even in the photoresist development step which is required to be highly accurate can be regenerated.

Description

technical field [0001] The present invention relates to a method for treating waste developing liquid recovered from the photoresist developing step in the manufacturing process of electronic components such as semiconductor devices (LSI, etc.), liquid crystal displays (LCD), and printed substrates. More specifically, it relates to a treatment method capable of stably refining the used tetraalkylammonium hydroxide aqueous solution (developing waste liquid) recovered from the above-mentioned developing step for a long period of time, and recycling the waste developing liquid as a developing solution. Background technique [0002] In the manufacturing process of electronic components such as semiconductor devices, liquid crystal displays, and printed circuit boards, a negative or positive photoresist film is formed on a substrate such as a wafer, and the photoresist is etched in a prescribed pattern through a mask. The photoresist film is irradiated with light, followed by a d...

Claims

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Application Information

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IPC IPC(8): G03F7/30C02F1/46C02F1/02H01L21/027
CPCG03F7/3092
Inventor 山下喜文大城户始野仲彻
Owner TOKUYAMA CORP
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