JP4582278B2 - Photoresist stripper composition - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a photoresist remover composition for removing a photoresist residue generated during dry etching of a transparent conductive film used in the manufacture of a liquid crystal display (LCD).
[0002]
[Prior art]
In recent years, liquid crystal displays (LCDs) have made great strides in the fields of notebook PCs, monitors, and portable information terminals, with the thin, lightweight, and low power consumption that cannot be achieved with CRTs.
Under such circumstances, high-definition displays, which are difficult to realize technically in CRT, are attracting attention as LCD markets. In high-definition displays, the size of the picture element, which is a structural unit of the screen, is reduced. Therefore, in order to secure the transmittance of the backlight that determines the surface brightness, the processing accuracy of the element is improved, It is required to narrow a gap between a certain ITO and each wiring. For these thin film processing, the dry etching method is generally advantageous from the viewpoint of processing accuracy and yield, and in the liquid crystal industry, the dry etching method is widely used for processing of semiconductor layers, metal layers, and insulating films. ing. In the dry etching process, a wiring material, an insulating film, or the like is formed on a substrate by sputtering, CVD, or the like. Further, a photoresist is applied on the film, a pattern is formed by exposure, development, and the like. In this process, an insulating film and a wiring pattern are formed by dry etching using a reactive gas using a photoresist as a mask. After this patterning, ashing is performed, and after removing the photoresist used as a mask by ashing, a remaining resist residue is generally removed by a stripping solution. Resist residue generated by such dry etching is damaged physically and chemically during the dry etching of the photoresist, and further forms a reaction product with the wiring material, dry etching gas, etc. Compared to a normal photoresist, it becomes extremely difficult to peel off.
In order to remove the photoresist residue generated at the time of dry etching as described above, one containing a fluorine compound (Japanese Patent Laid-Open No. 7-201794), one containing a quaternary ammonium hydroxide (Japanese Patent Laid-Open No. -262746 gazette) etc. are proposed, but in all cases, the photoresist residue after dry etching of ITO cannot be completely removed, there is no attack on the wiring material and insulating film, and the photoresist residue is completely peeled off There is a need for stripping solutions that can be made.
[0003]
[Problems to be solved by the invention]
The present invention is to provide a safe and simple release agent composition that is excellent in removability and does not contain an organic solvent with respect to a photoresist residue generated during dry etching of a transparent conductive film in an LCD manufacturing process. is there.
[0004]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventors have found that an aqueous solution containing an aliphatic polycarboxylic acid, an aqueous solution containing an aliphatic polycarboxylic acid and an anionic surfactant, and an aliphatic polycarboxylic acid. It has been found that a release agent comprising an aqueous solution containing an acid, an anionic surfactant and a phosphoric acid-based chelating agent has an excellent effect of removing a photoresist residue generated during dry etching of a transparent conductive film. The invention has been completed.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Examples of the aliphatic polycarboxylic acid used in the present invention include oxalic acid, malonic acid, succinic acid, maleic acid, adipic acid, tartaric acid, malic acid, citric acid and the like. The concentration of the aliphatic polycarboxylic acid is in the range of 0.1 to 15% by weight. However, when the concentration is lower than 0.1% by weight, the removal of the photoresist residue is deteriorated, and when the concentration is 15% by weight or more, the transparent conductive material is used. Corrosion is severely undesirable.
[0006]
Examples of the anionic surfactant used in the present invention include fatty acid salts, higher alcohol sulfate esters, liquid fatty oil sulfate esters, aliphatic amine and aliphatic amide sulfates, and aliphatic alcohol phosphates. Examples thereof include anionic surfactants such as salts, sulfonic acids of dibasic fatty acid esters, fatty acid amide sulfonates, and alkyl allyl sulfonates.
The concentration of the anionic surfactant is in the range of 0.001 to 1% by weight. If 0.001% by weight or less, the removability of the photoresist residue is poor, and if it is 1% by weight or more, the removability of the photoresist residue is It does not improve and is not a good idea.
[0007]
On the other hand, phosphoric acid chelating agents used in the present invention include methyl diphosphonic acid, aminotrismethylene phosphonic acid, ethylidene diphosphonic acid, 1-hydroxyethylidene-1, 1-diphosphonic acid, 1-hydroxypropionic acid. Liden-1,1-diphosphonic acid, ethylaminobismethylenephosphonic acid, dodecylaminobismethylenephosphonic acid, nitrilotrismethylenephosphonic acid, ethylenediaminebismethylenephosphonic acid, ethylenediaminetetrakismethylenephosphonic acid, hexanediaminetetrakismethylenephosphonic acid, diethylenetriaminepenta Phosphonic acid chelating agents having one or more phosphonic acid groups in the molecule such as methylenephosphonic acid and 1,2-propanediaminetetramethylenephosphonic acid, or their ammonium salts, organic amine salts, alkali metal salts, etc. Gerare, as their oxidant, these phosphonic acid-based chelating - those having a nitrogen atom in the molecule of the bets agents include those become oxidized with N- oxide form.
Examples of the condensed phosphoric acid include metaphosphoric acid, tetrametaphosphoric acid, hexametaphosphoric acid, tripolyphosphoric acid, or ammonium salts, metal salts, organic amine salts thereof, and the like.
Any of the above chelating agents can be used, more preferably those having 2 or more phosphonic acid groups in the molecule, and still more preferably those having 2 to 6 phosphonic acid groups in the molecule. It is done. Specifically, 1,2-propanediaminetetramethylenephosphonic acid, diethylenetriaminepentamethylenephosphonic acid, ethylenediaminetetrakismethylenephosphonic acid, and the like are preferable, and 1,2-propanediaminetetramethylenephosphonic acid, ethylenediaminetetrakismethylene are particularly preferable. Phosphonic acid.
The chelating agents used in the present invention may be used alone or in combination of two or more, as appropriate. Further, the concentration of the chelating agent is usually used at a concentration of 0.001 to 5% by weight, preferably 0.005 to 3% by weight in the whole solution.
[0008]
The release agent composition of the present invention is intended to remove a photoresist residue after dry etching, and is basically used in the form of an aqueous solution.
The photoresist residue that is the subject of the present invention is a transparent conductive film used in the production of LCD, and specifically, indium tin oxide (ITO) is generally used. It is a photoresist residue generated during dry etching of oxide, zinc oxide or the like.
The temperature at which the release agent composition of the present invention is used is from room temperature to 90 ° C., and the release time is about 1 to 30 minutes.
In the present invention, after the treatment with the release agent described above, water is sufficient for rinsing and it is not necessary to use an organic solvent.
[0009]
【Example】
[0010]
Example 1
FIG. 1 shows the state of the substrate from which ITO 4 is sputtered on SiNx 2 as an insulating film, photoresist is used as a mask, dry etching is performed, and ashing using oxygen plasma is performed to remove the photoresist. As a result of observing the substrate of FIG. 1 with an electron microscope (SEM), a photoresist residue 3 remained on ITO4 and SiNx2. Using the substrate shown in FIG. 1, using a release agent that is an aqueous solution containing 3% by weight of oxalic acid, immersing in the release agent at 50 ° C. for 15 minutes, rinsing with water, and then drying As a result of SEM observation, as shown in FIG. 2, the photoresist residue 3 was completely removed.
[0011]
Example 2
Using the substrate used in Example 1, 3% by weight of oxalic acid, and an anionic surfactant High-Tenol NE-05 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) which is a polyoxyethylene alkylphenyl ether sulfate salt Was immersed in a release agent, which is an aqueous solution containing 0.01% by weight, at 50 ° C. for 10 minutes, rinsed with water, dried and subjected to SEM observation. As a result, the photoresist residue was completely removed.
[0012]
Example 3
Using the substrate used in Example 1, 3% by weight of oxalic acid, polyoxyethylene alkylphenyl ether sulfate anionic surfactant Hytenol NE-05 (Daiichi Kogyo Seiyaku Co., Ltd.) 0.01 After immersing in a release agent, which is an aqueous solution containing 0.01% by weight of ethylenediaminetetrakismethylenephosphonic acid by weight, at 50 ° C. for 5 minutes, rinsed with water, dried and subjected to SEM observation. As a result, the photoresist residue was completely removed.
[0013]
Examples 4-9, Comparative Examples 1-2
Using the substrate used in Example 1, treatment with the release agent shown in Table 1 and rinsing with water, followed by SEM observation are shown.
The criteria for the peelability in SEM observation were according to the following criteria.
(Double-circle): The photoresist residue was removed completely.
X: Most of the photoresist residue remained.
[0014]
[Comparative Example 3]
Using the same substrate as in Example 1, 1.0% by weight of ammonium fluoride, 70% by weight of dimethyl sulfoxide, and the remaining part of water were immersed in a release agent at 23 ° C. for 15 minutes, followed by rinsing with water. After drying, SEM observation was performed.
As a result, most of the photoresist residue remained.
[0015]
Comparative Example 4
Using the same substrate as in Example 1, tetramethylammonium hydroxide 0.3% by weight, sorbitol 5.0% by weight, using a release agent with the balance being water, after performing immersion at 23 ° C. for 15 minutes, After rinsing with water, drying and SEM observation were performed.
As a result, most of the photoresist residue remained.
[0016]
【The invention's effect】
When the photoresist remover composition of the present invention is used, the photoresist residue generated during the dry etching of the transparent conductive film can be completely removed, and the wiring material and the insulating film are not corroded.
[Brief description of the drawings]
FIG. 1 is a state diagram of a substrate after sputtering of ITO on an insulating film, using a photoresist as a mask, performing dry etching, and performing ashing with oxygen plasma to remove the photoresist.
FIG. 2 is a state diagram after the substrate shown in FIG. 1 is immersed in a release agent that is an aqueous solution containing 3% by weight of oxalic acid, rinsed with water, and dried.
[Explanation of symbols]
1: Substrate 2: SiNx 3: Photoresist residue 4: ITO

Claims (2)

Photoresist stripper composition comprising an aqueous solution containing an aliphatic polycarboxylic acid , an anionic surfactant, and a phosphoric acid-based chelating agent , used for stripping a photoresist residue generated during dry etching of a transparent conductive film object. The photoresist stripping composition according to claim 1, wherein the transparent conductive film is indium tin oxide.

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