JP5885045B1 - Resist stripper and method for producing the same - Google Patents

Abstract

A hard-baked resist film is more than necessary for polymerization of a novolac resin and a DNQ compound, and is firmly fixed to a metal film as a base. For this reason, there are cases in which a hard-baked resist film cannot be peeled off with a common resist stripping solution that can peel off the resist film on the Cu film, Cu / Mo film, and Al film. A resist stripping solution comprising a cyclic amine, a polar solvent, water, and an anticorrosive agent, wherein each component is allowed to elapse for 24 hours or more, particularly pyrrolidine or pyrrolidine as a cyclic amine. There is provided a resist stripping solution using at least one of the compounds having a substituent bonded to the 3-position of and a reducing starch syrup or a mixture of sugar alcohol and polyethylene glycol as an anticorrosive. [Selection figure] None

Description

  The present invention is a stripping solution for stripping a resist used in the manufacture of display devices such as liquid crystal and organic EL and semiconductors. More specifically, even a hard-baked resist film can remove a resist, and further, aluminum The present invention also relates to a resist stripper that can be said to be substantially free from corrosion even with respect to a film and a copper film.

  A flat panel display (FPD) such as a liquid crystal or an organic EL (Electro-Luminescence) is required to have a large screen. On the other hand, small high-definition screens are required for notebook PCs, tablet PCs, and smartphones. For large screens, TFTs (Thin Film Transistors) using Cu wiring or Cu / Mo laminated wiring (hereinafter also simply referred to as “Cu wiring”) are used. In addition, TFTs using Al wiring are used for small high-definition screens. Hereinafter, Cu is also called copper, Mo is called molybdenum, and Al is also called aluminum.

  Some panel manufacturers produce TFTs using Al wiring and TFTs using Cu wiring in one factory. When both TFTs using Al wiring and TFTs using Cu wiring are produced, the resist stripping solution can be shared between the case of using Al wiring and the case of using Cu wiring in the resist film peeling process. If possible, production costs can be reduced.

  The aqueous positive photoresist stripping solution is generally composed of alkanolamine, a polar solvent, and water, and is heated to about 40 to 50 ° C. in a resist stripping apparatus.

  Alkanolamine is an essential component for solubilizing the carbonyl group of a DNQ (diazonaphthoquinone) compound, which is an alkali insolubilizing agent, in a positive photoresist stripping solution in a polar solvent and water by nucleophilic action. Alkanolamines are classified as primary, secondary, and tertiary depending on the number of substituents other than hydrogen bonded to the nitrogen element. Among these, it is known that the smaller the series, the stronger the basicity and the stronger the nucleophilicity.

  Therefore, the smaller the series, the stronger the ability to solubilize the DNQ compound, which is an alkali insolubilizing agent, in a polar solvent or water, and a stronger resist stripping performance.

  On the other hand, alkanolamines are known to have a chelating action on Cu. The chelating action for Cu solubilizes Cu and thus corrodes the Cu film. The chelating action for Cu is stronger as the alkanolamine series is smaller as is the case with basicity and nucleophilicity. Therefore, the alkanolamine with a smaller series corrodes the Cu film more strongly.

  In the production process of high-definition TFTs using Al wiring, in a dry etching process of a semiconductor (amorphous silicon: hereinafter also referred to as “a-Si”), the resist is damaged and denatured, and the resist is peeled off. It can be difficult. This is presumably because the polymerization of the DNQ compound and the novolak resin constituting the positive resist film proceeds excessively.

  The Al wiring does not receive a corrosive action (chelating action) caused by alkanolamine. Therefore, in order to remove the modified resist, it is common to use a primary alkanolamine having strong release performance.

  On the other hand, in the case of Cu wiring, when primary or secondary alkanolamine is used, corrosion of Cu wiring often occurs to an unacceptable level. Therefore, a stripping solution using a tertiary alkanolamine has been proposed. Tertiary alkanolamines have a weak chelating action on Cu, and can suppress the corrosion of the Cu film to a practically acceptable range. However, the basicity and nucleophilicity are weak as well as the chelating action, and there is a drawback that the resist stripping force is weak compared to a resist stripping solution using a primary or secondary alkanolamine.

  Under such a technical background, there is a need for a resist stripping solution composition that has a stripping performance equivalent to or better than that of a resist stripping solution for Al wiring using primary alkanolamine and can be used for both Cu wiring and Al wiring. It has been.

  Patent Document 1 discloses a resist stripping solution containing a compound represented by the formula (1) and a solvent. It is said that this resist stripper can also be used in the resist stripping process for Cu wiring and Al wiring.

Japanese Patent No. 5279921

  The resist film is used when a wiring or the like is formed through an etching process after being exposed and developed. Here, a step called post-bake is passed before the etching step. This is performed for the purpose of making the resist film harder before etching is performed. By this post-baking, the polymerization of the novolak resin constituting the resist film and the DNQ compound as the alkali insolubilizer proceeds further, and the resist film is prevented from peeling from the surface of the metal film during the etching process.

  However, in this post-baking process, if the heating temperature rises too much (hard bake state), the polymerization of the novolak resin and DNQ compound that occurs in the resist film proceeds so much that the conventional resist stripping solution cannot be stripped. .

  In this regard, Patent Document 1 has studied hard baking, and it is said that the resist can be stripped even under conditions of hard baking at 160 ° C. for 5 minutes. Therefore, it is said that the stripping solution of Patent Document 1 can strip the resist even in the case of an unexpected situation that may occur during the manufacture of hard baking.

  However, the compound of the formula (1) has a problem that it is a special compound that is not commercially available as a reagent or an industrial raw material.

  The present invention has been conceived in view of the above problems, and even if a problem of hard baking occurs in the manufacturing process, Cu that can peel off the resist film after etching without stopping the manufacturing line. The present invention provides a resist stripping solution that can be used in a stripping process for wiring and Al wiring.

More specifically, the resist stripper according to the present invention is:
It includes a cyclic amine, a polar solvent, water, and an anticorrosive agent, and each component is allowed to elapse for 24 hours or more after preparation.

  The resist stripping solution according to the present invention can be used in common in the resist stripping process for Cu wiring (including Cu / Mo laminated wiring) and Al wiring. Further, even if the resist film is hard-baked, the resist film can be peeled off. In addition, the resist stripping solution according to the present invention can strip the resist film that has been hard-baked in this way, while also damaging the Cu film, the Mo film disposed as the base of the Cu film, and the Al film. There is no.

  Therefore, even if it is a resist film on an aluminum film or a resist film on a copper film, it can be stripped with one type of resist stripping solution. That is, it is not necessary to prepare a plurality of types of resist film stripping process lines, and the resist stripping solution may be managed in one type. Also, a process called ashing is not necessary. As a result, it is possible to contribute greatly to productivity and cost reduction in the factory.

It is a figure explaining the taper angle and Mo undercut of a Cu / Mo laminated film.

  Hereinafter, the resist stripping solution according to the present invention will be described. The following description shows an embodiment of the photoresist stripping solution according to the present invention, and the following embodiments and examples may be modified without departing from the gist of the present invention.

  The resist film from which the resist stripping solution according to the present invention is peeled assumes a positive resist. The positive resist includes a novolac resin as a resin, and a diazonaphthoquinone (DNQ) compound is used as a photosensitive agent. When etching is performed, a resist film is formed on the substrate, and exposure is performed through the pattern.

  This exposure turns the DNQ compound into indenketene. When indenketene associates with water, it turns into indenecarboxylic acid and dissolves in water. The novolac resin originally has a property of being dissolved in an alkaline solution, but the melting point is protected by a DNQ compound. The DNQ compound is altered by exposure and is dissolved in a developer containing water, so that the novolak resin is also dissolved. In this way, patterning of the resist film is completed.

  The substrate on which the patterning is completed with the resist film is subjected to wet etching or dry etching processing through post-baking. Post bake is performed in order to advance polymerization of the novolak resin and the DNQ compound in the resist film to some extent. Usually, the heat treatment is performed at 140 ° C. for about 5 minutes. In this specification, hard baking refers to heating conditions at 150 ° C. for 5 minutes or more. When the baking temperature rises, the novolak resin and the DNQ compound rapidly polymerize and firmly adhere to the underlying metal film, making it difficult to dissolve. The resist stripping solution according to the present invention is also intended for a resist film that has undergone such hard baking.

  The resist stripping solution according to the present invention includes a cyclic amine, a polar solvent, water, and an additive. The additive includes an anticorrosive.

  As the cyclic amine, a 5-membered cyclic amine is desirable, and in particular, pyrrolidine or one having a substituent bonded to the 3-position of pyrrolidine is desirable. For example, 3-methylpyrrolidine, (S) -3-ethylpyrrolidine, 3-aminopyrrolidine, 3-acetamidopyrrolidine, 3- (N-acetyl-N-ethylamino) pyrrolidine, 3- (N-acetyl-N-methylamino) ) Pyrrolidine, (R) -3-hydroxypyrrolidine, and 3- (ethylamino) pyrrolidine are preferably used. These cyclic amines are effective in removing a hard-baked resist film. In addition, pyrrolidine is generally distributed as a fragrance such as an intermediate for medicines and agricultural chemicals and gum, and is an easily available compound. Therefore, the cost of the stripping solution itself can be reduced.

  It has been found that the amount of cyclic amine added varies depending on the type of anticorrosive described below. When reduced starch syrup is used as an anticorrosive agent, a range of more than 0.2% by mass and less than 1.0% by mass is a preferable range with respect to the total amount of the resist stripping solution. More desirably, it is 0.5 mass% or more and 0.8 mass% or less.

  Further, when a mixed solution of sugar alcohol alone and polyethylene glycol is used, the cyclic amine is more than 0.2% by mass and less than 0.8% by mass with respect to the total amount of the resist stripping solution. More desirably, it is 0.3 mass% or more and 0.7 mass% or less. If the amount of cyclic amine is too large, the copper film and the molybdenum film are corroded, and if it is too small, the resist film that has undergone hard baking cannot be removed.

  In the present specification, the expression “0.3 mass% or more and 0.7 mass% or less” is expressed as “0.3 mass% to 0.7 mass%” or “0.3 to 0.7 mass%”. May also be described.

  The polar solvent may be an organic solvent having an affinity for water. Moreover, it is more suitable if the mixing property with said cyclic amine is favorable.

  Examples of such water-soluble organic solvents include sulfoxides such as dimethyl sulfoxide; sulfones such as dimethyl sulfone, diethyl sulfone, bis (2-hydroxyethyl) sulfone, and tetramethylene sulfone; N, N-dimethylformamide, N-methyl Amides such as formamide, N, N-dimethylacetamide, N-methylacetamide, N, N-diethylacetamide; N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-propyl-2-pyrrolidone, N -Lactams such as hydroxymethyl-2-pyrrolidone and N-hydroxyethyl-2-pyrrolidone; 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, 1,3-diisopropyl -2-imidazolidinones such as imidazolidinone; Glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether Propylene glycol monoalkyl ether such as diethylene glycol monoalkyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether Ruki ethers (alkyl is a lower alkyl group having 1 to 6 carbon atoms) are exemplified polyvalent alcohols, and derivatives thereof, and the like.

  Among these, at least one selected from dimethyl sulfoxide, N-methyl-2-pyrrolidone, and diethylene glycol monobutyl ether, and at least one mixed liquid selected from ethylene glycol, diethylene glycol, and propylene glycol are preferable. Available. In particular, for a positive resist, a desired result can be obtained by using a mixed liquid of diethylene glycol monobutyl ether (BDG) and propylene glycol (PG) as a polar solvent.

  In the resist stripping solution according to the present invention, a mixed solution of diethylene glycol monobutyl ether (BDG) and propylene glycol (PG) can be suitably used as a polar solvent. These polar solvents dissolve and facilitate dissolution of the resist film. In particular, propylene glycol swells the resist film, and diethylene glycol monobutyl ether (BDG) dissolves the resist film. Therefore, a polar solvent containing at least two liquids is effective.

  The polar solvent is preferably 50 to 80% by mass with respect to the total amount of the resist stripping solution.

  In addition, the resist stripping solution according to the present invention contains water separately from the polar solvent. As the water, normal pure water can be used. Water becomes a ratio of 14.2 mass%-49.3 mass% with respect to the whole resist stripping solution.

  In the resist stripping solution, the cyclic amine strips the resist film, but also corrodes the underlying metal thin film. Therefore, an anticorrosive agent is added to alleviate this. As the anticorrosive, reduced starch syrup can be suitably used. Reduced starch syrup refers to a sugar alcohol containing less than 75% reduced maltose (maltitol) and less than 50% sorbitol, but may contain other sugar alcohols.

  The reduced starch syrup as an anticorrosive agent in the present invention is a mixture of monosaccharide alcohol, disaccharide alcohol, trisaccharide alcohol, tetrasaccharide alcohol, and pentasaccharide alcohol, with 37 to 43% by mass of monosaccharide alcohol and 26 disaccharide alcohol. A composition having ˜32 mass%, trisaccharide alcohol of 15 to 21 mass%, tetrasaccharide alcohol of 6 to 10 mass%, and pentasaccharide alcohol of 4 to 8 mass% is preferable.

  The saccharide contains a carbonyl group in addition to a ketone group or an aldehyde group in its structure. In order to remove the hard-baked resist, the strong corrosive force of the cyclic amine is used. However, the cyclic amine is modified by causing a Maillard reaction with the carbonyl group. Due to the modification of the cyclic amine, the hard-baked resist film cannot be dissolved.

  On the other hand, when the saccharide is reduced, the carbonyl group is changed to a hydroxyl group to become a sugar alcohol. If it is a sugar alcohol, even if it is used simultaneously with the cyclic amine, the cyclic amine will not be denatured. Reduced starch syrup, which is a mixture of sugar alcohols, does not modify the cyclic amine.

  The anticorrosive agent may be a mixed solution of sugar alcohol alone and polyethylene glycol. As a single sugar alcohol, sorbitol, xylitol, sucrose, mannitol, maltitol, lactitol and the like can be suitably used.

  These anticorrosives suppress the dissolution of the Al film in the resist stripping solution and suppress the undercut of the Mo film.

  0.5-5 mass% is suitable for an anticorrosive with respect to resist stripping solution whole quantity. More desirably, the content is 0.5 to 3% by mass. The anticorrosive has a role as a corrosion inhibitor for the metal film by the cyclic amine. Therefore, it is desirable to contain a certain amount. However, it does not contribute much to the resist film peeling. On the other hand, when the anticorrosive containing sugar alcohol is excessively added, when the resist stripping solution is regenerated by distillation, it remains in the distillation apparatus and causes scaling. Therefore, it is good to contain in said range.

  As described above, the resist stripping solution according to the present invention contains at least a sugar alcohol such as sorbitol as an anticorrosive. The boiling point of sugar alcohol is often higher than that of other polar solvents and cyclic amines.

  Therefore, when the resist stripping solution is used to perform distillation to re-extract each component, the sugar alcohol remains at the end. When sugar alcohol is solidified in the distillation apparatus, the piping in the distillation apparatus is clogged first, and then causes various obstacles to the distillation apparatus. Therefore, the resist stripping solution according to the present invention may contain a high boiling point solvent having a boiling point higher than that of other polar solvents when the distillation treatment is performed.

  The high boiling point solvent desirably has a higher boiling point than the component used as the polar solvent. Further, the high boiling point solvent is preferably one that can dissolve the sugar alcohol and the resist component. Furthermore, it is desirable that it can be easily dissolved in water. Accordingly, polyols having a high boiling point can be suitably used. When the resist stripping solution is regenerated by distillation, the sugar alcohol and the resist component remain as the last residue. This is to prevent these residues from solidifying at that time.

  For example, if the polar solvents that can be suitably used are propylene glycol (boiling point 188 ° C.) and diethylene glycol monobutyl ether (boiling point 230 ° C.), a solvent having a boiling point higher than 230 ° C. is used. In this case, specific high boiling point solvents include polyols such as glycerin (boiling point 290 ° C.), diethylene glycol (boiling point 244 ° C.), 1,5-pentanediol (boiling point 242 ° C.), 1,6-hexanediol (boiling point). 250 ° C.), 1,7-heptanediol (boiling point 258 ° C.), 1,10-decanediol (boiling point 297 ° C.) and the like.

  Further, ethers in polyols include ethylene glycol monophenyl ether (boiling point 245 ° C.), triethylene glycol monomethyl (boiling point 249 ° C.), diethylene glycol dibutyl ether (boiling point 256 ° C.), triethylene glycol butyl methyl ether (boiling point). 261 ° C.), polyethylene glycol dimethyl ether (boiling point 264 to 294 ° C.), tetraethylene glycol dimethyl ether (boiling point 275 ° C.), polyethylene glycol monomethyl ether (boiling point 290 to 310 ° C.) and the like.

  The resist stripping solution according to the present invention is preferably left for 24 hours or longer after each raw material solution is prepared. Although shown also in the Example mentioned later, the corrosion of a metal film cannot be prevented with the resist stripping solution immediately after preparation. However, the ability to prevent corrosion of the metal film is manifested by leaving it for 24 hours or longer.

  Examples and comparative examples of resist stripping solutions according to the present invention are shown below. The resist stripping solution was evaluated for two points: “resist strippability” and “corrosiveness of metal film”.

<Resist peelability>
A silicon thermal oxide film having a thickness of 100 nm was formed on a silicon substrate, and a copper film having a thickness of 300 nm was formed on the silicon thermal oxide film by sputtering. A positive resist solution was applied onto the copper film by spin coating to prepare a resist film. After the resist film was dried, it was exposed using a wiring pattern mask. Then, the resist in the exposed portion was removed with a developer. That is, there is a state where there is a portion where the resist film of the wiring pattern remains on the copper film and a portion where the copper film is exposed.

  Thereafter, the entire silicon substrate was post-baked at 150 ° C. for 10 minutes. This is a process of reproducing hard baking.

  Next, the exposed copper film was removed by etching using a superaqueous copper etchant. After the etching of the copper film was completed, the resist film on the remaining copper pattern was stripped using a sample resist stripping solution. The time for removing the resist film was examined in three stages, 40 seconds, 80 seconds, and 120 seconds. Then, the substrate was washed, and it was observed while interfering with an optical microscope whether or not the resist film remained on the copper film. When the remainder of the resist film was confirmed on the copper film, it was set to “x” (X), and when the remaining resist film was not confirmed, it was set to “◯” (maru). Note that “◯” (maru) means success or success, and “x” (cross) means failure or failure. The same applies to the following evaluations.

<Corrosiveness of metal film>
The corrosivity of the metal film was evaluated as follows. First, a silicon thermal oxide film was formed to a thickness of 100 nm on a silicon substrate, and a copper film was formed to a thickness of 300 nm on the silicon thermal oxide film by sputtering to prepare a Cu film sample. This is called “Cu gate”. Similarly, a molybdenum film was formed to a thickness of 20 nm on a silicon thermal oxide film on a silicon substrate, and a copper film was subsequently formed to a thickness of 300 nm to prepare a Cu / Mo laminated film sample. . This is called “Cu / Mo gate”. In addition, an aluminum film was formed to a thickness of 300 nm on the silicon thermal oxide film on the silicon substrate to produce an Al film sample. This is called “Al gate”.

  A resist patterned into a wiring shape was formed on these evaluation samples, and used as a base material for corrosive evaluation. In other words, the base material for corrosivity evaluation is a resist formed in a wiring shape on a Cu film, Cu / Mo film, or Al film formed on a silicon thermal oxide film on a silicon substrate. Consists of layers.

  Etching was performed by immersing these corrosive evaluation base materials in an etchant for copper film or aluminum film for the time of just etching. Thereafter, the substrate for corrosion evaluation after etching was immersed in a sample resist stripper for 6 minutes to strip the resist film. After the corrosive evaluation base material immersed in the sample resist stripping solution for 6 minutes was washed and dried, the wiring portion was cut and the cut surface was observed.

  In the evaluation of corrosivity, the resist film is not subjected to heat treatment until it is in a hard bake state. Moreover, the judgment of just etching was made when the silicon thermal oxide film was visually confirmed from the start of etching.

  Observation of the cut surface was performed using SEM (Scanning Electron Microscope) (Hitachi: SU8020 type) under the conditions of an acceleration voltage of 1 kV and 30,000 to 50,000 times.

  The cut surface shape is shown in FIG. FIG. 1A shows a cut surface shape in the case of Cu Gate and Al Gate. The cut surface shape of the just-etched portion has a taper angle 5 of approximately 30 ° to 60 ° with respect to the substrate 1. The film part 2 is a Cu film in the case of Cu Gate, and an Al film in the case of Al Gate.

  FIG. 1B shows the case of Cu / Mo Gate. In the case of Cu / Mo Gate, at least the upper Cu layer 2 has a taper angle 5. The underlying Mo layer 3 is preferably etched along the tapered surface 6 of the Cu layer 2. However, as shown in FIG. 1B, there may be an etching residue 7 from the Cu layer 2.

  Corrosivity is evaluated as “×” (X) if corrosion is confirmed on either the film part 2 or the surface 4 of the film part 2 or the underlying Mo layer 3 by observing the cross-sectional shape. When no corrosion was observed, it was judged as “◯” (maru).

  In particular, in the case of Cu / Mo Gate, corrosion may occur between the underlying Mo layer 3 and Cu layer 2 as shown in FIG. That is, Mo dissolution starts from the interface between the copper layer 2 and the molybdenum layer 3 and the molybdenum layer 3 may be selectively etched earlier than the copper layer 2. Therefore, when the gap 10 was confirmed between the Mo layer 3 and the Cu layer 2, the evaluation was x (X).

<Sample resist stripper>
A sample resist stripping solution was prepared as follows. The sample resist stripping solution is composed of a cyclic amine, a polar solvent, water, and an anticorrosive.

(1) Example 1
Pyrrolidine (PRL) was used as the cyclic amine.
Pyrrolidine (PRL) 0.8% by mass
Two types of polar solvents were mixed.
Propylene glycol (PG) 27.2% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
Water 30.0% by mass
Reduced starch syrup using reduced starch syrup as an anticorrosive 2.0% by mass
The above was mixed and stirred and allowed to stand for 24 hours to obtain a sample resist stripping solution of Example 1.
Through the following Examples and Comparative Examples, reduced starch syrup is 40% by mass of monosaccharide alcohol, 29% by mass of disaccharide alcohol, 18% by mass of trisaccharide alcohol, and tetrasaccharide alcohol with respect to the total amount of reduced starch syrup. 8% by mass and 5% by mass of pentasaccharide alcohol were used.

(2) Example 2
In Example 2, the amount of cyclic amine was reduced from that in Example 1.
Pyrrolidine was used as the cyclic amine.
Pyrrolidine (PRL) 0.5% by mass
Two types of polar solvents were mixed.
Propylene glycol (PG) 28.5% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
Water 30.0% by mass
Reduced starch syrup using reduced starch syrup as an anticorrosive agent 1.0% by mass
The above was mixed and stirred and allowed to stand for 24 hours to obtain a sample resist stripping solution of Example 2.

(3) Example 3
In Example 3, the type of cyclic amine was changed.
3- (Ethylamino) pyrrolidine was used as the cyclic amine.
3- (Ethylamino) pyrrolidine 0.8% by mass
Two types of polar solvents were mixed.
Propylene glycol (PG) 27.2% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
Water 30.0% by mass
Reduced starch syrup using reduced starch syrup as an anticorrosive 2.0% by mass
The above was mixed and stirred and allowed to stand for 24 hours to obtain a sample resist stripping solution of Example 3.
In addition, 3- (ethylamino) pyrrolidine is a compound represented by the following formula (2).

(4) Example 4
In Example 4, the type of the anticorrosive was changed.
Pyrrolidine was used as the cyclic amine.
Pyrrolidine (PRL) 0.5% by mass
Two types of polar solvents were mixed.
Propylene glycol (PG) 27.0% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
Water 30.0% by mass
As an anticorrosive, sorbitol (Stol) and polyethylene glycol (average molecular weight 6000) (PEG 6000) were used.
Sorbitol (Stol) 1.5% by mass
Polyethylene glycol (PEG6000) 1.0 mass%
The above was mixed and stirred and allowed to stand for 24 hours to obtain a sample resist stripping solution of Example 4.

  Table 1 shows the composition of the sample resist stripping solution and the results of “resist stripping property” and “corrosiveness of metal film” for Examples 1 to 4 described above.

(5) Comparative Example 1
Comparative Example 1 has the same composition as Example 1, but is a sample resist stripper immediately after preparation.
Pyrrolidine was used as the cyclic amine.
Pyrrolidine (PRL) 0.8% by mass
Two types of polar solvents were mixed.
Propylene glycol (PG) 27.2% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
Water 30.0% by mass
Reduced starch syrup using reduced starch syrup as an anticorrosive 2.0% by mass
The sample immediately after mixing and stirring the above was used as the sample resist stripping solution of Comparative Example 1.

(6) Comparative Example 2
In Comparative Example 2, as compared with Example 4 (Stol + PEG6000), the anticorrosive was only sorbitol.
Pyrrolidine (PRL) 0.5% by mass
Two types of polar solvents were mixed.
Propylene glycol (PG) 28.0% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
Water 30.0% by mass
Sorbitol (Stol) 1.5% by mass using sorbitol as an anticorrosive
The above was mixed and stirred and allowed to stand for 24 hours to obtain a sample resist stripping solution of Comparative Example 2.

(7) Comparative Example 3
In Comparative Example 3, as compared with Example 4 (Stol + PEG6000), the amount of the anticorrosive was changed to only polyethylene glycol, and the amount was increased.
Pyrrolidine (PRL) 0.5% by mass
Two types of polar solvents were mixed.
Propylene glycol (PG) 27.5% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
Water 30.0% by mass
Polyethylene glycol using polyethylene glycol as an anticorrosive (PEG6000) 2.0 mass%
The above was mixed and stirred and allowed to stand for 24 hours to obtain a sample resist stripping solution of Comparative Example 3.

(8) Comparative Example 4
In Comparative Example 4, the amount of cyclic amine was increased with respect to Example 4 (PRL = 0.5% by mass).
Pyrrolidine was used as the cyclic amine.
Pyrrolidine (PRL) 0.8% by mass
Two types of polar solvents were mixed.
Propylene glycol (PG) 26.7% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
Water 30.0% by mass
As an anticorrosive, sorbitol (Stol) and polyethylene glycol (average molecular weight 6000) (PEG 6000) were used.
Sorbitol (Stol) 1.5% by mass
Polyethylene glycol (PEG6000) 1.0 mass%
The above was mixed and stirred and allowed to stand for 24 hours to obtain a sample resist stripping solution of Comparative Example 4.

(9) Comparative Example 5
In Comparative Example 5, the amount of cyclic amine was further reduced with respect to Example 2 (PRL = 0.5% by mass).
Pyrrolidine was used as the cyclic amine.
Pyrrolidine (PRL) 0.2% by mass
Two types of polar solvents were mixed.
Propylene glycol (PG) 28.8% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
Water 30.0% by mass
Reduced starch syrup using reduced starch syrup as an anticorrosive agent 1.0% by mass
The above was mixed and stirred and allowed to stand for 24 hours to obtain a sample resist stripping solution of Comparative Example 5.

(10) Comparative Example 6
In Comparative Example 6, the amount of cyclic amine was further increased with respect to Example 1 (PRL = 0.8 mass%).
Pyrrolidine (PRL) 1.0% by mass
Two types of polar solvents were mixed.
Propylene glycol (PG) 27.0% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
Water 30.0% by mass
Reduced starch syrup using reduced starch syrup as an anticorrosive 2.0% by mass
The above was mixed and stirred and allowed to stand for 24 hours to obtain a sample resist stripping solution of Comparative Example 6.

(11) Comparative Example 7
The comparative example 7 made the anticorrosive agent the (non-reduced) varicella with respect to Example 1 (reduced varicella).
Pyrrolidine (PRL) 0.8% by mass
Two types of polar solvents were mixed.
Propylene glycol (PG) 27.2% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
Water 30.0% by mass
As an anticorrosive agent, Minamata using non-reduced Minamata 2.0 mass%
The above was mixed and stirred and allowed to stand for 24 hours to obtain a sample resist stripping solution of Comparative Example 7.

  Table 2 shows the composition of the sample resist stripping solution and the results of “resist stripping property” and “corrosiveness of metal film” for Comparative Examples 1 to 7 described above.

  Next, in order to confirm the peeling effect of the additive five-membered cyclic amine, the following comparative example was performed.

(12) Comparative Example 8
2-methylpyrrolidine was used as the five-membered cyclic amine.
2-Methylpyrrolidine 2.0% by mass
Two types of polar solvents were mixed.
Propylene glycol (PG) 28.0% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
Water 30.0% by mass
In 2-methylpyrrolidine, a methyl group is bonded to the 2-position of pyrrolidine.
The above was mixed and stirred to obtain a sample resist stripping solution of Comparative Example 8.

(13) Comparative Example 9
As the 5-membered cyclic amine, 1-methylpyrrolidine was used.
1-methylpyrrolidine 2.0% by mass
Two types of polar solvents were mixed.
Propylene glycol (PG) 28.0% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
Water 30.0% by mass
1-methylpyrrolidine has a methyl group bonded to the 1-position (nitrogen position) of pyrrolidine.
The above was mixed and stirred to obtain a sample resist stripping solution of Comparative Example 9.

  Table 3 shows the results of the sample resist stripping solution compositions and “resist stripping properties” for Comparative Examples 8 and 9 described above.

  A large amount of the resist stripping solution is used in the resist stripping process. Therefore, it is desirable that the resist stripping solution once used can be reused after being subjected to a distillation treatment, divided into each component. As described above, in order to facilitate the reuse, it is desirable to add a high boiling point solvent that dissolves the sugar alcohol remaining as a residue in the distillation process.

  On the other hand, if the addition of such a high boiling point solvent lowers the peelability of the hard-baked resist or reduces the effect of the anticorrosive, it cannot be used as a resist stripper. Therefore, it was confirmed by the following examples that a high boiling point solvent can be used in the composition of the resist stripping solution according to the present invention.

(14) Example 5
In Example 5, glycerin was further added to a polar solvent with respect to Example 2 (PRL = 0.5 mass%).
Pyrrolidine was used as the cyclic amine.
Pyrrolidine (PRL) 0.5% by mass
Three types of polar solvents were mixed.
Propylene glycol (PG) 26.5% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
Glycerin 2.0% by mass
Water 30.0% by mass
Reduced starch syrup using reduced starch syrup as an anticorrosive agent 1.0% by mass
The above was mixed and stirred and allowed to stand for 24 hours to obtain a sample resist stripping solution of Example 5.

(15) Example 6
In Example 6, glycerol was further contained in the polar solvent with respect to Example 1 (PRL = 0.8 mass%).
Pyrrolidine was used as the cyclic amine.
Pyrrolidine (PRL) 0.8% by mass
Three types of polar solvents were mixed.
Propylene glycol (PG) 25.2% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
Glycerin 2.0% by mass
Water 30.0% by mass
Reduced starch syrup using reduced starch syrup as an anticorrosive 2.0% by mass
The above was mixed and stirred and allowed to stand for 24 hours to obtain a sample resist stripping solution of Example 6.

(16) Example 7
In Example 7, glycerol was further contained in a polar solvent with respect to Example 3 (3- (ethylamino) pyrrolidine).
As the cyclic amine, 3- (ethylamino) pyrrolidine was used.
3- (Ethylamino) pyrrolidine 0.8% by mass
Three types of polar solvents were mixed.
Propylene glycol (PG) 25.2% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
Glycerin 2.0% by mass
Water 30.0% by mass
Reduced starch syrup using reduced starch syrup as an anticorrosive 2.0% by mass
The above was mixed and stirred and allowed to stand for 24 hours to obtain a sample resist stripping solution of Example 7.

  Table 4 shows the composition of the sample resist stripping solution and the results of “resist stripping property” and “corrosiveness of metal film” for Examples 5 to 7.

  In Tables 1 to 4, each% represents mass% with respect to the total amount of the resist stripping solution. PG represents propylene glycol, and BDG represents diethylene glycol monobutyl ether.

  Example 1 (Table 1) and Comparative Example 1 (Table 2) have exactly the same composition. Example 1 was left for 24 hours after compounding, whereas Comparative Example 1 was a sample resist stripper immediately after compounding. In Comparative Example 1, the hard-baked resist film could be removed in 120 seconds. This was the same characteristic as in Example 1. However, in Comparative Example 1, Mo undercut was observed. On the other hand, in Example 1, Mo undercut was not recognized.

  As described above, in the resist stripping solution according to the present invention, after all the raw materials are prepared, the anticorrosion function for the metal film is exhibited by leaving (aging) for 24 hours or more.

  Reference is now made to Example 1 (Table 1) and Comparative Example 7 (Table 2). Both of these have a composition containing 0.8% by mass of pyrrolidine, and the ratios of the polar solvent and water are the same. Moreover, the ratio (2.0 mass%) of anticorrosive is also the same. However, the anticorrosive agent in Example 1 was a reduced starch syrup, whereas Comparative Example 7 was just a syrup.

  However, this difference in composition greatly changed the evaluation results. Specifically, in Example 1, the hard-baked resist was peeled off, and no damage to the metal film including the Mo undercut was observed. On the other hand, in Comparative Example 7, the hard-baked resist could not be removed. Furthermore, Mo undercut occurred.

  Next, Examples 1 and 2 (Table 1) and Comparative Examples 5 and 6 (Table 2) will be referred to. Both of these samples use pyrrolidine and use reduced starch syrup as an anticorrosive. However, they differ in pyrrolidine content.

  In Comparative Example 5, the amount of pyrrolidine is 0.2% by mass. The amount of pyrrolidine in Comparative Example 5 is less than 0.5% by weight of Example 2. As a result, Comparative Example 5 could not remove the hard-baked resist. In Comparative Example 5, there was no damage to the metal film including the Mo undercut.

  On the other hand, Comparative Example 6 has a composition in which the amount of pyrrolidine is as large as 1.0% by mass. As a result, the hard-baked resist could be peeled off. However, there was much damage to the metal film including the Mo undercut, and it was clearly thought that there was too much pyrrolidine. From the above results, the content of pyrrolidine is preferably more than 0.2% by mass and less than 1.0% by mass. Furthermore, it is preferable that it is 0.5 mass% or more and 0.8 mass% or less.

  Reference is now made to Example 4 (Table 1) and Comparative Examples 2, 3, 4 (Table 2). These contain sorbitol or polyethylene glycol as an anticorrosive. Reference is made to Comparative Examples 2 and 3. These are the case where sorbitol is used alone (Comparative Example 2) and the case where polyethylene glycol is used alone (Comparative Example 3). In either case, the hard-baked resist could be peeled off. However, Mo undercut has occurred.

  Reference is now made to Comparative Example 4. Comparative Example 4 contains sorbitol and polyethylene glycol 1.5% by mass and 1.0% by mass, respectively, as in Example 4. However, although the comparative example 4 was able to peel the hard-baked resist, Mo undercut occurred. In Comparative Example 4, pyrrolidine was 0.8% by mass.

  From these comparisons, it is understood that when sorbitol and polyethylene glycol are used as anticorrosives, two must be used in combination and pyrrolidine should be less than 0.8% by mass.

  Example 3 is a case where the type of cyclic amine is 3- (ethylamino) pyrrolidine. The sample stripping solution of Example 3 was a resist stripping solution that can strip the hard-baked resist and that causes little damage to the metal film including the Mo undercut. Then, what can be utilized in 5-membered cyclic amines other than pyrrolidine and 3- (ethylamino) pyrrolidine was examined.

  Table 3 shows a review of the types of five-membered cyclic amines. Comparative Example 8 is an example using 2-methylpyrrolidine, and Comparative Example 9 is an example using 1-methylpyrrolidine. In both cases, only whether or not the hard-baked resist stripping solution can be stripped was examined. Therefore, the damage of the metal film such as Mo undercut is not examined.

  The pyrrolidine used in the examples was able to peel off the hard-baked resist film in 120 seconds (see Examples 1 to 4). On the other hand, 1-methylpyrrolidine (Comparative Example 9) and 2-methylpyrrolidine (Comparative Example 8) in which methyl groups are bonded to the 1-position and 2-position are resist films that are hard-baked for 120 seconds. It could not be peeled off. From the above, it is concluded that pyrrolidine having a substituent bonded to the 1-position and 2-position of pyrrolidine cannot peel the hard-baked resist film within a practical range.

  On the other hand, pyrrolidine having a substituent at the 3-position, such as 3- (ethylamino) pyrrolidine shown in Example 3, and the substituents shown in Examples 1, 2, and 4 are not usually bonded. Of pyrrolidine was able to peel off the hard-baked resist film. From the above, pyrrolidine or pyrrolidine having a substituent at the 3-position can be used as a component of the resist stripping solution of the present invention.

  Reference is now made to Examples 5-7. These sample stripping solutions contain glycerin having a boiling point higher than that of propylene glycol and diethylene glycol monobutyl ether used as polar solvents. As already explained, by including a solvent having a boiling point higher than that of the components other than the sugar alcohol component, the sugar alcohol can be prevented from solidifying even when the resist stripping solution is subjected to a distillation treatment.

  Moreover, with reference to Examples 5-7, all of these Examples can peel the hard-baked resist, and there is no damage to a metal film including Mo undercut. That is, the performance of the resist stripper according to the present invention was maintained even when glycerin, which is a high boiling point solvent, was included.

  As described above, the resist stripping solution according to the present invention includes a cyclic amine, a polar solvent, water, and an anticorrosive agent, so that it is commonly used in the resist stripping process of Cu film, Cu / Mo film, and Al film. can do. Furthermore, even if the resist film is hard-baked, it can be peeled off.

  The resist stripping solution of the present invention can be suitably used as a resist stripping solution when a positive resist is used. This can be suitably used for general production of FPD such as a liquid crystal display, a plasma display, and an organic EL.

1 Substrate 2 Film part 3 Mo layer (underlayer)
4 Surface 5 (of film part 2) Taper angle 6 Tapered surface 7 Etching remaining 10 Clearance

Claims (7)

A cyclic amine, a polar solvent, water, and an anticorrosive,
The cyclic amine is pyrrolidine or a 5-membered cyclic amine having a substituent at the 3-position of pyrrolidine,
Containing more than 0.2% by mass and less than 1.0% by mass with respect to the total amount,
The anticorrosive is a reduced starch syrup,
A resist stripping solution, wherein each component has passed for 24 hours or more after preparation. A cyclic amine, a polar solvent, water, and an anticorrosive,
The cyclic amine is pyrrolidine or a 5-membered cyclic amine having a substituent at the 3-position of pyrrolidine,
More than 0.2% by mass and less than 0.8% by mass with respect to the total amount,
The anticorrosive is a mixed solution of sorbitol and polyethylene glycol,
A resist stripping solution, wherein each component has passed for 24 hours or more after preparation. Before SL polar solvent is 50 to 80 wt%,
Before SL anticorrosive, resist stripping solution as claimed in any Kano claim according to claim 1 or 2, characterized in that 0.5 to 5 wt%. The resist stripping solution according to any one of claims 1 to 3 , further comprising glycerin. The resist stripping solution according to claim 4 , wherein the glycerin is 0.5 to 5% by mass with respect to the total amount of the resist stripping solution. Mixing a cyclic amine, a polar solvent, water, and an anticorrosive;
Having 24 hours or more after the preparation of each component,
The cyclic amine is pyrrolidine or a 5-membered cyclic amine having a substituent at the 3-position of pyrrolidine,
Containing more than 0.2% by mass and less than 1.0% by mass with respect to the total amount,
A method for producing a resist stripping solution, wherein the anticorrosive is a reduced starch syrup. Mixing a cyclic amine, a polar solvent, water, and an anticorrosive;
Having 24 hours or more after the preparation of each component,
The cyclic amine is pyrrolidine or a 5-membered cyclic amine having a substituent at the 3-position of pyrrolidine,
More than 0.2% by mass and less than 0.8% by mass with respect to the total amount,
A method for producing a resist stripping solution, wherein the anticorrosive is a mixed solution of sorbitol and polyethylene glycol.