KR20020054887A - Composition for removing resist - Google Patents

Abstract

PURPOSE: Provided is a composition for removing resist, polymers, organometallic polymers, and metal oxides, which dose not damage a lower membrane and dose not leave residues after rinsing. CONSTITUTION: The composition for removing resist contains: alkoxy N-hydroxy alkyl alkane amide(formula 1: R4-O-R3-CO-N-R1R2OH); at least one compound selected from the group consisting of alkanol amine(formula 2: NH-R1-R2OH), a polar substance with a dipole moment of more than 3, and an attack inhibitor(formula 3:R6(OH)n); a viscosity controlling agent. The polar substance is water, methanol, or dimethyl sulfoxide. In the formula, R1 is H, C1-C5 hydrocarbon, or aromatic hydrocarbon having 1-3 rings, R2 is C1-C5 hydrocarbon or aromatic hydrocarbon having 1-3 rings, R3 and R4 are each C1-C5 hydrocarbon, R6 is C1-C5 hydrocarbon, -COOH bonded C1-C5 hydrocarbon, aromatic hydrocarbon having 1-3 rings, or -COOH bonded aromatic hydrocarbon having 1-3 rings, and n is an integer of 1-4.

Description

Composition for removing resist

The present invention relates to a composition for removing a resist.

Removal of resist is a very important process for manufacturing semiconductor devices. After performing various processes for manufacturing a semiconductor device, such as an etching process (dry or wet) or an ion implantation process, the resist pattern used as a mask must be removed. Also, even if the resist pattern is misaligned, it must be removed to form a new resist pattern. In particular, various different material films (for example, an oxide film, an aluminum film, a copper film, a polysilicon film, a silicide film, or a polyimide film) exist under the resist film to be removed. The main issue of the resist removal process is therefore to remove the resist completely from the substrate surface as soon as possible without damaging the underlying film.

Generally, the resist removal process is a combination of a dry strip process such as an ashing process and a wet strip process using an organic stripper. The wet strip process removes the remaining resist from impurities in the ashing process, which is a dry strip process, and impurities such as residues generated in the etching process and the ashing process from the surface of the integrated circuit board. Residues to be removed include organic polymers formed by reacting plasma with components such as C, H, and O, which form a resist pattern during the plasma etching or reactive ion etching (RIE) process, and the wiring during the etching or ashing process. And organic metallic polymers formed by back-sputtering materials into sidewalls of contact holes or via holes formed by resist patterns and etching processes.

To date, the main component is a basic amine reducing agent such as hydroxyamine, diglycolamine, monoethanolamine or methylethanolamine, polar solvent such as water, and the like. Organic strippers composed of organic acids such as solvents and catechol are widely used.

However, since the basic amine constituting the organic stripper has a relatively low reducing power, it does not completely remove etching residues (metal oxides or organometallic polymers) generated during the formation of wirings or contact holes. Therefore, a step of treating nitric acid solution is required as a pre-ashing step before the ashing process.

In addition, the conventional organic stripper is mainly composed of organic components and the like and has a high viscosity, so that when rinsed only with deionized water, the organic stripper may remain on the substrate to act as organic contamination or form residue.

In addition, water, which is a polar solvent of the organic stripper, can easily corrode the underlying film exposed to the stripper, especially the wiring film, thereby modifying the profile of the wiring pattern. Therefore, a rinsing process using an alcohol-based rinsing agent such as isopropyl alcohol (hereinafter referred to as IPA) should be further performed.

Therefore, in order to enhance the removal force of polymers and prevent corrosion of the wiring film, the nitric acid treatment step should be performed as an ashing pretreatment step or the IPA rinse step should be further performed before the deionized water rinse process, resulting in a complicated resist removal process and a longer process time. It lowers productivity. In addition, since the pretreatment material (nitric acid) and aftertreatment material (isopropyl alcohol) must be consumed in addition to the resist remover, the production cost increases. In addition, the volume of the resist removal apparatus becomes unnecessarily large because each bath for pretreatment and posttreatment is required.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a resist removing composition having excellent properties of removing resists, polymers, organometallic polymers, and metal oxides, not causing damage to the underlying film, and having no residue after rinsing. .

1 is a flowchart illustrating a resist removing step according to the present invention, in which a dotted line indicates a step that is omitted when using the resist removing composition according to the present invention as a conventional resist removing step.

The resist removal composition according to the present invention for achieving the above technical problem is an alkoxy N-hydroxyalkyl alkanamide; At least one compound selected from the group consisting of alkanol amines, polar substances having a dipole moment of at least 3 and damage inhibitors; And viscosity modifiers.

The resist removing composition according to the present invention is not only excellent in resist removing ability, but also effectively removing polymers, organometallic polymers, and metal oxides. It also has the property of leaving no residue after rinsing without damaging the underlying film exposed to the composition.

Hereinafter, the resist removing composition and the resist removing method using the same according to the present invention will be described in detail. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various forms, and only the present embodiments are intended to complete the disclosure of the present invention and to those skilled in the art to fully understand the scope of the invention. It is provided to inform you.

At least one compound selected from the group consisting of alkoxy N-hydroxyalkyl alkanamide, an alkanol amine, a polar substance having a dipole moment of 3 or more, and an attack inhibitor, according to an embodiment of the present invention, And viscosity modifiers.

Preferably, the alkoxy N-hydroxyalkyl alkanamide is represented by the following formula (1).

R ₄ -OR ₃ -CO-NR ₁ R ₂ OH

Wherein R ₁ is H atom, C 1 -C 5 hydrocarbon or aromatic hydrocarbon having 1-3 ring structure; R ₂ is an aromatic hydrocarbon having 1 to 5 carbon atoms or 1 to 3 ring structures; R ₃ and R ₄ each represent a hydrocarbon having 1 to 5 carbon atoms.

Most preferably in the above formula, R ₁ is H atom, R ₂ is -CH ₂ CH _2- , R ₃ is -CH ₂ CH ₂ -and R ₄ is -CH ₃ .

Preferably the alkanol amine is a compound represented by the following formula (2).

NH-R ₁ -R ₂ OH

In the above formula, R ₁ represents an H atom, a hydrocarbon having 1 to 5 carbon atoms or an aromatic hydrocarbon having 1 to 3 ring structures, and R ₂ represents an aromatic hydrocarbon having 1 to 5 hydrocarbons or 1 to 3 ring structures. .

More preferably, monoethanolamine in which R ₁ is H atom and R ₂ is -CH ₂ CH ₂ -is used as the alkanolamine of the present invention.

Preferably, the damage inhibitor is represented by the following formula (3).

R _6- (OH) _n

In the above formula, R ₆ is a hydrocarbon having 1 to 5 carbon atoms, a hydrocarbon having 1 to 5 carbon atoms bonded to a -COOH group, an aromatic hydrocarbon having 1 to 3 ring structures, or 1 to 1 bonded to a -COOH group An aromatic hydrocarbon having three ring structures, n is an integer and represents 1-4.

In particular, catechol in which R ₆ is a benzene ring and n is 2 is preferable as a damage preventing agent. In addition, other damage inhibitors, gallic acid, may be used.

As a polar material having a dipole moment of 3 or more, water, methanol or dimethyl sulfoxide may be used.

As the viscosity modifier according to the present invention, 1-methyl-2-pyrrolidinone (1-methyl-2-pyrrolidinone) is suitable.

The resist removal composition according to the present invention not only has excellent resist removal ability, but also can effectively remove the polymer and the organic metallic polymer, and does not damage the underlying film exposed to the composition. It also has a viscosity suitable for rinsing with deionized water. The mechanism of action of the resist removal composition according to the present invention is as follows.

Alkoxy N-hydroxyalkyl alkanamides include hydroxy (-OH) groups, alkoxy groups (-OR ₄ ) and carbonyl groups (C═O). Therefore, it is very effective for exfoliation and dissolution of resist and polymer.

In addition, it reacts with an organometallic polymer or the like as in Scheme 1 below to easily remove the organometallic polymer from the substrate surface.

※ Mp stands for organometallic polymer.

Alkanol amines are also effective for the removal of organometallic polymers. The mechanism of action of the alkanol amine is shown in Scheme 2 below by taking monoalkanolamine as an example.

※ Mp stands for organometallic polymer.

Polar materials with dipole moments of 3 or more exhibit high solubility in cross-linked polymers and resists. That is, the polymer that is strongly bonded to the sidewalls of the resist pattern and the exposed lower layer surface can be effectively removed, and the resist can also be easily removed.

The damage preventing agent functions not only as a dissolving agent for the organometallic polymer but also serves to prevent corrosion or damage of the metal film when the metal film is exposed on the surface of the integrated circuit board. The mechanism by which the damage preventing agent prevents damage to the metal film is described by using catechol as an example.

※ M represents metal

The viscosity modifier makes the viscosity of the resist composition easy to remove with deionized water.

Table 1 shows the resist removal compositions and the weight percentage of each component according to the present embodiment as described above.

Resist Removal Composition Alkoxy Nhydroxyalkylalkanamides (wt%) Alkanolamine (% by weight) Polar material (% by weight) Damage prevention agent (% by weight) Viscosity regulator (wt%) One 30-99.9 0.01-69.99 0.01-30 2 30-99.9 0.01-69.99 0.01-30 3 30-99.9 0.01-69.99 0.01-30 4 30-99.9 0.01-30 0.01-30 0.01-30 5 30-99.9 0.01-30 0.01-30 0.01-30 6 30-99.9 0.01-30 0.01-30 0.01-30 7 30-99.9 0.01-30 0.01-30 0.01-30 0.01-30

The content range of the above-described compositions can effectively remove the resist and the polymer, minimize the damage to the underlying film exposed to the resist removal composition, such as the metal film, and have a viscosity that can be rinsed with deionized water. To show the optimal range.

Composition 7 of the above-described compositions is the most excellent resist and polymer removal ability, there is an advantage that does not cause damage to the metal film when there is a metal film as a resist lower film. In addition, when the amine is included together with the amide, such as compositions 1, 4, 5, and 7, the resist and polymer removal ability are further improved.

On the other hand, the compositions (1, 2, 4) that do not contain a damage preventing agent may also have the same effect as the composition of 7 when a material damaged by the composition, such as a metal film, is not exposed to the resist removing composition. In addition, compositions (1, 3, 5) which do not contain polar substances with dipole moments of 3 or more are used when the prevention of damage to the metal film is a more important factor, or when the amount of polymer to be removed is very small or the polymer removal pretreatment When the process is carried out, the same effects as in the composition of 7 can be obtained.

The step of removing the resist using the resist removing composition according to the present invention will be described with reference to FIG.

First, a resist pattern is formed through a photo process. Subsequently, various processes for completing a semiconductor device using a resist pattern as a mask, for example, an etching (dry or wet) process or an ion implantation process, are performed. Subsequently, ashing, which is a dry strip process, is performed on the substrate on which the resist pattern is formed (step 110). Next, a wet strip process is performed to remove the resist, the polymer, and the organometallic polymers by contacting the resist removing composition shown in Table 1 (step 120). In the method of contacting with the resist removal composition, the resist removal composition is immersed in a bath, and the substrate is contacted by immersing the substrate therein or by spraying the resist removal composition onto the substrate.

When using the resist removal composition according to the present invention, the resist removal step may be carried out at a low temperature of 70 ℃ or less. In particular, it is possible to carry out at a temperature of room temperature to 70 ℃, preferably 45 ℃ to 70 ℃. And 10 to 30 minutes are suitable for a contact time.

The resist that can be removed by the resist removing composition of the present invention is not only used for conventional i-line (365 nm) resists and KrF excimer laser (248 nm) resists, but also for ArF excimer laser (193 nm) resists for short wavelength exposure sources. Applicable.

When the resist removal is completed, a step of rinsing the resist removing composition and the dissolved resist remaining on the substrate surface is performed (step 140). Rinse is carried out using deionized water and may be carried out in two stages as necessary. Finally, the substrate is dried by spin drying or dry using isopropyl alcohol to remove pure water remaining on the surface of the substrate (step 150).

The substrate completed by the drying step 150 is transferred to the next process. When the resist is used again in a subsequent process, after the desired process is completed, the used resist is removed again through the process of FIG. 1. The semiconductor device is completed through the repeating unit process and resist removal process.

As can be seen in Figure 1, the resist removal composition according to the present invention is excellent in the removal power of the polymer, organometallic polymer and metal oxide as well as the resist removal power. Thus, unlike the prior art, the resist removal pretreatment step (step 100) is not necessary. In addition, since the damage to the resist underlayer is prevented and has a viscosity suitable for rinsing with deionized water, the step of removing the resist after-treatment (step 130) may be omitted. Therefore, the resist can be completely removed in a very simplified process compared to the conventional removal process, and in the resist removal apparatus, a bath or the like necessary for the pretreatment step (step 100) and the post-treatment step (step 130) of the resist removal is not required. Therefore, the resist removal apparatus is simplified. In addition, there is no need to use materials used in the pretreatment and posttreatment steps, such as nitric acid and IPA, which can significantly improve the productivity of semiconductor devices.

The resist removing composition according to the present invention is not only excellent in resist removing ability, but also effectively removing polymers, organometallic polymers, and metal oxides. In addition, the lower film exposed to the resist removing composition is not damaged. In addition, since it has a suitable viscosity so that no residue remains after rinsing, it can be rinsed clean with deionized water after removing the resist. Therefore, when using the resist removal composition according to the present invention, a resist removal pretreatment step for removing residues such as polymers and a post-treatment step for preventing damage to the underlying film are unnecessary. Thus, the resist removal process can be simplified and the processing time can be shortened. In addition, the resist removing apparatus for using the resist removing composition according to the present invention can also be simplified and reduced in weight.

Claims (4)

Alkoxy N-hydroxyalkyl alkanamides; At least one compound selected from the group consisting of alkanol amines, polar substances having a dipole moment of at least 3 and damage inhibitors; And A resist removal composition comprising a viscosity modifier. The composition of claim 1, wherein the alkoxy N-hydroxyalkyl alkanamide is represented by the following formula (1). <Formula 1> R ₄ -OR ₃ -CO-NR ₁ R ₂ OH Wherein R ₁ is H atom, hydrocarbon having 1 to 5 carbon atoms or aromatic hydrocarbon having 1 to 3 ring structures, R ₂ is aromatic hydrocarbon having 1 to 5 hydrocarbons or 1 to 3 ring structures, R ₃ and R ₄ each represent hydrocarbons having 1 to 5 carbon atoms. The method of claim 1, wherein the alkanol amine is represented by the following formula (2), <Formula 2> R ₁ -NH-R ₂ OH Wherein R ₁ represents an H atom, an aromatic hydrocarbon having 1 to 5 hydrocarbons or 1 to 3 ring structures, and R ₂ represents an aromatic hydrocarbon having 1 to 5 hydrocarbons or 1 to 3 ring structures . The polar substance is water, methanol or dimethyl sulfoxide, The damage preventing agent is a composition for removing a resist, characterized in that the compound represented by the formula <Formula 3> R _6- (OH) _n In the above formula, R ₆ is a hydrocarbon having 1 to 5 carbon atoms, a hydrocarbon having 1 to 5 carbon atoms bonded to a -COOH group, an aromatic hydrocarbon having 1 to 3 ring structures or a 1 to 3 bonded to a -COOH group Aromatic hydrocarbon having three ring structures, n is an integer and represents 1-4. According to claim 1, wherein the alkoxy N-hydroxyalkyl alkanamide is in an amount of 30 to 99.9% by weight based on the total weight of the resist removing composition, The alkanol amine, the polar substance, and the damage preventing agent, respectively, in an amount of 0.01 to 30% by weight based on the total weight of the resist removing composition, The viscosity adjusting agent is a resist removal composition, characterized in that it comprises in an amount of 0.01 to 30% by weight relative to the total weight of the resist removal composition.