KR102609535B1 - Composition for coating photoresist pattern and method for forming fine pattern using the same - Google Patents

Abstract

A composition for coating a photoresist pattern that can reduce the line width of a photoresist pattern by forming a coating film on the surface of the photoresist pattern and a method of forming a fine pattern using the same are disclosed. The composition for photoresist pattern coating includes a polymer resin containing a repeating unit represented by Formula 1, an acidic crosslinking agent represented by Formula 2, and a solvent.

Description

Composition for coating photoresist pattern and method for forming fine pattern using the same {Composition for coating photoresist pattern and method for forming fine pattern using the same}

The present invention relates to a composition for photoresist pattern coating, and more specifically, to a composition for photoresist pattern coating that can reduce the line width of a photoresist pattern by forming a coating film on the surface of the photoresist pattern, and a method for forming a fine pattern using the same. It's about.

Recently, with the development of semiconductor device manufacturing technology and the expansion of application fields of memory devices, research is being conducted to improve the integration of memory devices. To this end, improvements in lithography processes, such as new photoresists, exposure sources, and exposure equipment, are being developed. However, the resolution that can be obtained with currently commercialized KrF and ArF exposure equipment and ArF immersion exposure equipment is limited. Since the hole pattern is about 0.07 ㎛, it is difficult to manufacture a highly integrated semiconductor device with a pattern of a finer size than this.

On the other hand, as a method for forming a fine pattern beyond the resolution of exposure equipment, (i) forming a pattern using photoresist and exposure equipment, applying a block copolymer to the space of the pattern, and then copolymerizing the block copolymer A method of heating the polymer above the glass transition temperature (Tg) and using the reflow of the copolymer to align the block copolymer into the shape of a pattern (Directed self-assembly (DSA) method) (ii) Photoresist and exposure A method of reducing the size of a contact hole or pattern is being developed by forming a pattern using equipment, then applying a water-soluble polymer to the pattern, and forming a coating film through a selective reaction of the photoresist and the water-soluble polymer. However, among the above methods, the method of heating the block copolymer to a temperature above the glass transition temperature has the disadvantage of easily causing profile changes in the formed micropattern. In addition, in the method using water-soluble polymers, it is difficult to form fine patterns smaller than a certain size (for example, line and space patterns of 30 nm or less or contact hole patterns of 40 nm or less), and the stability of line width decreases depending on temperature. After forming a coating film, foreign substances (scum) remain on the bottom of the pattern, or micro bridges and not-opens occur due to inter-mixing of the pattern and water-soluble polymer due to high pH. It has the disadvantage of being prone to defects. Here, a micro bridge is a defect in which the resist in the space area is not completely removed during the development process after coating and adjacent lines are connected (the concept of a short circuit), and a not-open is a hole A defect that occurs in the pattern is that the resist in the space area is not completely removed, so the resist remains inside the hole pattern. After the etching process, metal cannot be deposited on the hole, so the upper and lower layer lines are formed. ) may not be connected (concept of disconnection).

The purpose of the present invention is to provide a composition for coating a photoresist pattern that can form a stable coating film on the surface of a photoresist pattern and a method of forming a fine pattern using the same.

Another object of the present invention is a composition for coating a photoresist pattern that can not only increase the amount of line width reduction of a photoresist pattern, but also reduce the generation of foreign substances, change in pattern line width depending on temperature, and line width unevenness of the pattern, and form a fine pattern using the same. It provides a method.

In order to achieve the above object, the present invention provides a composition for photoresist pattern coating, which includes a polymer resin containing a repeating unit represented by the following formula (1), an acidic crosslinking agent represented by the following formula (2), and a solvent.

[Formula 1]

In Formula _{1 ,} R ^* is hydrogen or a methyl group, It is a chain-shaped or cyclic saturated or unsaturated hydrocarbon group of 1 to 10 carbon atoms containing hydrogen or 0 to 4 heteroatoms, and R ₁ and R ₂ may be connected to each other to form a ring structure.

[Formula 2]

In Formula 2, Y is a simple chemical bond or a chain or cyclic saturated or unsaturated hydrocarbon group of 1 to 8 carbon atoms containing 0 to 6 heteroatoms, and R ₃ and R ₄ are each independently a carboxyl group. An acid group (-COOH), a sulfonic acid group (-SO ₃ H), a hydroxy group (-OH), NH ₄ ⁺ O- or NH ₄ OSO ₂ -, and a is an integer of 1 to 3.

In addition, the present invention includes the steps of (a) forming a photoresist pattern (first photoresist pattern) on a substrate; (b) forming a coating film for pattern reduction by coating the photoresist pattern coating composition of claim 1 on the photoresist pattern; and (c) removing a portion of the pattern reduction coating film to form a second photoresist pattern on the first photoresist pattern.

The composition according to the present invention can form a stable coating film on the surface of the photoresist pattern, and can effectively increase the amount of line width reduction of the photoresist pattern while suppressing changes in the line width and non-uniformity of the line width of the pattern.

1 is a diagram illustrating a method of forming a fine pattern using a composition for photoresist pattern coating according to an embodiment of the present invention.
Figure 2 is a scanning electron microscope photograph of a photoresist pattern (primary pattern) formed by a conventional method.
3 and 4 are scanning electron microscope photographs of fine patterns (secondary patterns) formed in examples and comparative examples of the present invention, respectively.
Figure 5 is a graph showing the amount of change in line width of fine patterns formed in examples and comparative examples of the present invention.

Hereinafter, the present invention will be described in detail with reference to the attached drawings.

The composition for photoresist pattern coating according to the present invention is intended to form a coating film (protective film) on the surface of the photoresist pattern to reduce the line width between the photoresist patterns, and includes a polymer resin, an acidic crosslinking agent, and a solvent.

The polymer resin used in the coating composition according to the present invention includes a repeating unit represented by the following formula (1).

[Formula 1]

In Formula 1, R ^* is hydrogen or a methyl group, and CH ₂ -), ethylene group (-CH ₂ CH ₂ -), propylene group (-CH ₂ CH ₂ CH ₂ -), isopropylene group (-CH(CH ₃ )CH ₂ -), n-butylene group (- CH ₂ CH ₂ CH ₂ CH ₂ -), s-butylene group (-CH(CH ₃ )CH ₂ CH ₂ -), t-butylene group (-CH ₂ CH(CH ₃ )CH ₂ -), pentylene group, It may be an alkylene group such as a cyclopentylene group, hexylene group, cyclohexylene group, heptylene group, or octylene group, or a carbonyl group, an acyl group, a ketone group, an ether group, an ester group, etc., and preferably has 1 to 3 carbon atoms. It is an alkylene group or a carbonyl group. In addition, R ₁ and R ₂ are each independently hydrogen or a chain or cyclic saturated or unsaturated hydrocarbon group of 1 to 10 carbon atoms containing 0 to 4 heteroatoms, for example, a methyl group, an ethyl group, or a propyl group. group, isopropyl group, n-butyl group, s-butyl group, t-butyl group, pentyl group, cyclopentyl group, hexyl group, cyclohexyl group, heptyl group, octyl group, etc., or an acyl group (acetyl group) etc.), an amide group (amide, -CONH ₂ ), etc., and is preferably hydrogen, an alkyl group having 1 to 4 carbon atoms, or an amide group. Here, R ₁ and R ₂ may be connected to each other to form a ring structure, and the hetero atom may be oxygen (O), sulfur (S), or nitrogen (N), and is preferably oxygen (O). .

Specific examples of the repeating unit represented by Formula 1 include: (Formula 1a), (Formula 1b), (Formula 1c), (Formula 1d), (Formula 1e), (Formula 1f), etc. may be exemplified. The polymer resin used in the present invention may be a polymer or copolymer consisting only of the repeating unit represented by Formula 1, and, if necessary, may further include other repeating units in addition to the repeating unit represented by Formula 1. Monomers capable of forming the other repeating units include, but are not limited to, N-vinyl pyrrolidone, acrylic acid, vinyl alcohol, methacrylic acid, and N-vinylimidazole. The content may be 0 to 99 mol%, for example, 0 to 90 mol%, based on the total repeating units. It is preferable to use a single type of polymer resin represented by Formula 1, but a mixture of two or more types may be used.

The polymer resin used in the present invention can be manufactured by polymerizing a vinyl monomer corresponding to the repeating unit represented by Formula 1 above. For example, by polymerizing allylamine and hydrochloric acid (CH ₂ =CHCH ₂ NH ₃ Cl) as a vinyl monomer and removing hydrochloric acid from the polymer, a polymer resin containing a repeating unit represented by Formula 1a can be prepared. there is. The polymer resin can be manufactured by any polymerization technique, such as bulk polymerization or solution polymerization, and is generally polymerized using a polymerization initiator such as an azo or peroxide initiator. The peroxide initiator may be acetyl peroxide, benzoyl peroxide, etc., and the azo initiator may be azobisisobutyronitrile (AIBN), 2,2'-azobis[2-(2-imidazoline), etc. -2-yl) propane] dihydrochloride, etc. can be used. The polymer resin used in the present invention is a material that reduces the line width between photoresist patterns by crosslinking on the surface of the photoresist pattern to form a coating film, and has a weight average molecular weight of 1000 to 100,000, preferably 1,000 to 50,000, and more. Preferably it is 3,000 to 30,000. If the weight average molecular weight of the polymer resin is too small, a coating film may not be formed, or the strength of the coating film may be reduced. If the molecular weight is too large, the polymer will not dissolve, making it difficult to form a coating film, or the thickness of the formed coating film may be low. There is a risk that it may become uneven.

In the coating composition according to the present invention, a compound represented by the following formula (2) is used as the acidic crosslinking agent.

[Formula 2]

In Formula 2, Y is a simple chemical bond or a chain containing 0 to 6 heteroatoms, for example, 1 to 3 carbon atoms, preferably 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms. It is a saturated or unsaturated hydrocarbon group in the form or ring, and R ₃ and R ₄ are acid functional groups, each independently a carboxylic acid group (-COOH), a sulfonic acid group (-SO ₃ H), It is a hydroxy group (-OH), NH ₄ ⁺ O- or NH ₄ OSO ₂ -, and a is an integer of 1 to 3. Preferred examples of Y include a simple chemical bond, methylene group (-CH ₂ -), ethylene group (-CH ₂ CH ₂ -), propylene group (-CH ₂ CH ₂ CH ₂ -), n-butylene group (- CH ₂ CH ₂ CH ₂ CH ₂ -), ethyl ketone group (-CH2CH2C(=O)-), trimethyl cyanuric acid group ( ), triethylcyanoic acid group ( ), etc. can be exemplified by hydrocarbon groups, and when Y is a simple chemical bond, a is 1. If necessary, the acidic crosslinking agent represented by Formula 2 may be used in the form of a salt or a hydrate to which water (H ₂ O) is added.

Specific examples of the acidic crosslinking agent represented by Formula 2 include: (Formula 2a), H ₂ SO ₄ (Formula 2b), (Formula 2c), (Formula 2d), (Formula 2e), (Formula 2f), (Formula 2g), etc. may be exemplified. In the coating composition according to the present invention, the acidic crosslinking agent contains 2 to 4 acid functional groups that are the same or different, and is crosslinked with amine groups in the composition. Compared to conventional crosslinking agents, the acidic crosslinking agent has the advantages of excellent thermal stability, excellent solubility in water-soluble compositions, and a low probability of defects occurring after the process. Additionally, to improve thermal stability and ease of use, a cross-linking agent with a salt structure can be used instead of a cross-linking agent having an OH group.

In the present invention, when only the polymer of Formula 1 is used, the pH is maintained at about 11 to 12, but when the acidic crosslinking agent is added, the pH is lowered to about 7 to 11. If the pH is high because it does not contain an acidic cross-linking agent, stains may remain on the top of the primary pattern when coated or the primary pattern may partially dissolve, which ultimately causes defects. Additionally, in the case of acidic cross-linking agents, they do not act as catalysts when participating in bonding, but rather participate in the reaction itself, so they take the form of ionic bonds. In the case of ionic bonding, thermal stability is excellent, so thermal stability can be improved in high temperature processes.

In the coating composition of the present invention, since the polymer resin is a water-soluble polymer, water (H ₂ O) or a lower alcohol having 8 carbon atoms or less can be used alone or in combination as the solvent, and if necessary, the coating of the composition To improve the properties, a mixed solvent of water and a water-miscible solvent can be used. Examples of such water-miscible solvents include low-carbon solvents having 8 or less carbon atoms, such as methanol, ethanol, propanol, isopropanol, butanol, isobutanol, t-butanol, pentanol, isopentanol, and 4-methyl-2-pentanol. Alcohol can be used.

In the composition for photoresist pattern coating according to the present invention, the content of the polymer resin containing the repeating unit represented by Formula 1 may vary depending on the polymer resin used, the type of solvent, etc., but is usually 1 to 60% by weight. , preferably 2 to 50% by weight, more preferably 5 to 50% by weight, and the content of the acidic crosslinking agent represented by Formula 2 is 0.001 to 4.5% by weight, preferably 0.002 to 3.0% by weight, more preferably is 0.005 to 2.0% by weight, and the solvent may be used as the remaining component of the composition in an amount of 40 to 98.999% by weight, preferably 50 to 98% by weight, and more preferably 50 to 95% by weight. Here, if the amount of the polymer resin used is too small or the amount of the solvent used is too large, excessive time and energy are consumed in forming the coating film, and if the amount of the polymer resin used is too large or the amount of the solvent used is too small, the coating film There is a risk that formation may be difficult or the thickness of the formed coating film may be uneven. In addition, if the amount of the acidic crosslinking agent used is too small, there is a problem that the shrinkage of the pattern decreases when forming the pattern and a high temperature must be used when implementing the target CD, and if it is used too much, the degree of crosslinking of the composition increases, making it easier to develop. There is a risk that it will not become a phenomenon. The composition for photoresist pattern coating according to the present invention may, if necessary, include a surfactant depending on the size and thickness of the photoresist pattern, for example, when the coating properties of the composition alone are poor. The surfactant includes, but is not limited to, salts of long-chain alkanoic acids such as laurate, stearate, and heptanoate, salts of alkyl sulfonic acids such as lauryl sulfonic acid, or various substituted salts of sulfonic acid amides. Conventional surfactants such as partially or fully fluorinated derivatives (ammonium ions may be used as their counter ions) can be used, and the concentration of these surfactants is usually 50 to 50,000 ppm, preferably 500 to 10,000 ppm. In addition, the coating composition of the present invention may further include other conventional additives such as conventional crosslinking agents, thermal acid generators, free acids, photoacid generators, antibacterial agents, preservatives, and pH adjusters. These additives do not affect the performance of the composition of the present invention, and are usually included in an amount of 1% by weight or less, preferably 0.1% by weight or less, based on the total composition. The pH of the composition according to the present invention is usually 5.5 to 11.0, preferably 7 to 10.8, and more preferably 8.2 to 10.6. If the pH is too low, the crosslinking rate between the crosslinking agent and the polymer is high, so there is a problem that development is not easy, and if it is too high, there is a risk of partially dissolving the primary pattern and making it defective.

Next, with reference to FIG. 1, a method of forming a fine pattern using a photoresist pattern coating composition will be described. In order to form a fine pattern according to the present invention, as shown in FIG. 1, if necessary, a photoresist film 20 is coated on the substrate 10 on which the anti-reflection film 12 is formed (A in FIG. 1). According to a typical lithography method, the photoresist film 20 is exposed and developed in a predetermined pattern to form a first photoresist pattern 22 (B in FIG. 1). The photoresist film 20 may be formed of any resist material capable of forming a pattern, for example, KrF resist, ArF resist, E-beam resist, EUVL (Extreme ultraviolet lithograph) resist, etc. You can. Next, the photoresist pattern coating composition according to the present invention is coated on the photoresist pattern 22, and the solvent is removed to form a coating film 30 for pattern reduction (C in FIG. 1). Next, a portion of the pattern reduction coating film 30 is removed to form a second photoresist pattern on the first photoresist pattern 22. Specifically, when the pattern reduction coating film 30 is baked at 80 to 180° C. for 30 to 300 seconds, preferably at 100 to 150° C. for 50 to 90 seconds, the photoresist pattern 22 and the pattern The reduction coating film 30 reacts to form a solvent-insoluble interface layer 32 on the surface of the photoresist pattern 22 (D in FIG. 1). Finally, the pattern reduction coating film 30 is developed with a solvent for the pattern reduction coating film 30, and the portion of the pattern reduction coating film 30 that does not form the solvent-insoluble interface layer 32 is removed. By doing so, the width (width of the line) of the photoresist pattern 22 is increased by the solvent-insoluble interface layer 32, creating a fine pattern in which the line width (width of the space portion) between adjacent photoresist patterns 22 is reduced. can be formed (E in Figure 1). As a solvent for the coating film 30 for pattern reduction, a typical water-soluble polymer developer such as deionized water can be used, and a solvent used in the photoresist pattern coating composition of the present invention can also be used. The thickness of the solvent-insoluble interface layer 32 formed on the photoresist pattern 22 is usually 1 to 50 nm, for example, 5 nm to 30 nm.

When a fine pattern is formed (reduction of the width of the space portion) using the photoresist pattern coating composition according to the present invention, compared to a typical pattern reduction compound, (i) the amount of reduction of the pattern can be increased, (ii) ) Not only is the size (CD: Critical Dimension) uniformity of the reduced pattern improved, but (iii) the pattern circularity after pattern reduction is improved compared to the circularity (degree of circularity) before reduction of the pattern ( In other words, the circle before improvement is squishy, but after improvement, a smooth circle is formed.) In addition, the coating composition according to the present invention can be applied to various types of resist to form fine patterns with resolution higher than that of exposure equipment.

Hereinafter, the present invention will be described in more detail through examples and comparative examples. The following examples are intended to illustrate the present invention, and the scope of the present invention is not limited by these examples.

[Preparation Example 1] Preparation of a polymer having a repeating unit represented by Formula 1a

In a 500 mL reactor with refluxed nitrogen gas, 93.4 g (1.0 mol) of allylamine hydrochloride and 2,2'-azobis[2-(2-imidazolin-2-yl)propane]dihydrochloride (VA- 044) 2.00 g was added, dissolved by mixing with 300 g of deionized water, and polymerized at 60°C for 24 hours. After the polymerization reaction was completed, the temperature was lowered to room temperature, 20 g each of the cation exchange resin Emberlyst 15 and the anion exchange resin Amberlite 21 were added to the reaction solution, stirred for 4 hours, and then the ion exchange resin was removed. 341 g of a 12.0 wt% aqueous solution of a polymer consisting of a repeating unit represented by Formula 1a was obtained (yield 72.0%).

[Preparation Example 2] Preparation of a polymer having a repeating unit represented by Formula 1b

In the same manner as Preparation Example 1, except that 121.4 g (1.0 mol) of N,N-dimethylallylamine hydrochloride was used instead of 93.4 g (1.0 mol) of allylamine hydrochloride, a repeating unit represented by Formula 1b was used. 356 g of a 15.7% by weight aqueous polymer solution was obtained (yield 66.0%).

[Preparation Example 3] Preparation of a polymer having a repeating unit represented by Formula 1c

In the same manner as Preparation Example 1, except that 145.5 g (1.0 mol) of N,N-diethylallylamine hydrochloride was used instead of 93.4 g (1.0 mol) of allylamine hydrochloride, a repeating unit represented by Formula 1c was produced. 366 g of an 18.0% by weight polymer aqueous solution consisting of was obtained (yield 58.0%).

[Preparation Example 4] Preparation of a polymer having a repeating unit represented by Formula 1d

In the same manner as Preparation Example 1, except that 145.5 g (1.0 mol) of N-t-butylallylamine hydrochloride was used instead of 93.4 g (1.0 mol) of allylamine hydrochloride, a polymer consisting of a repeating unit represented by Formula 1d was produced. 359 g of a 16.4% by weight aqueous solution was obtained (yield 52.0%).

[Preparation Example 5] Preparation of a polymer having a repeating unit represented by Formula 1e

In the same manner as Preparation Example 1, except that 136.4 g (1.0 mol) of allylurea hydrochloride was used instead of 93.4 g (1.0 mol) of allylamine hydrochloride, 14.5% by weight of a polymer consisting of a repeating unit represented by Formula 1e was produced. 351 g of aqueous solution was obtained (yield 51.0%).

[Preparation Example 6] Preparation of a polymer having a repeating unit represented by Formula 1f

In a 500 mL reactor with refluxed nitrogen gas, 113.2 g (1.0 mol) of N-isopropylacrylamide and 2.00 g of azobisisobutyronitrile (AIBN) were added and dissolved by mixing with 300 g of acetonitrile, followed by 80 g. Polymerization was carried out at ℃ for 12 hours. After the polymerization reaction was completed, the temperature was lowered to room temperature, and the reaction solution was added dropwise to 3 L of diethyl ether to solidify the resin. The solidified resin was filtered and dried in a vacuum oven at 40° C. for 8 hours to obtain 98 g of a polymer resin composed of a repeating unit represented by Chemical Formula 1f (yield 86.6%).

[Examples 1-1 to 1-13, Comparative Examples 1 to 4] Preparation of composition for photoresist pattern coating

As shown in Table 1 below, a polymer resin composed of repeating units represented by Chemical Formulas 1a to 1f synthesized in Preparation Examples 1 to 6, an acidic crosslinking agent represented by Chemical Formulas 2a to 2e, and a solvent are mixed to prepare a mixture for photoresist pattern coating. A composition was prepared (Examples 1-1 to 1-11). Additionally, as a comparative example, a composition for photoresist pattern coating was prepared using only a polymer resin and a solvent (Comparative Examples 1 to 2). In Table 1 below, surfactant S-465 is a brand name of Airproduct, alcohol represents isopropanol, and the additive in Comparative Example 3 is 2-(2-aminoethylamino)ethanol.

division polymer
(Usage, g) crosslinking agent
(Usage, g) Surfactants
(Usage, g) Solvent (g) escape
hot water Alcohol Example 1-1 Formula 1a (49.9) Formula 2a (1.5) S-465 (0.2) 48.4 - Example 1-2 Formula 1b (38.1) Formula 2a (1.5) S-465 (0.2) 60.2 - Example 1-3 Formula 1c (33.3) Formula 2a (1.5) S-465 (0.2) 65.0 - Example 1-4 Formula 1d (36.5) Formula 2a (1.5) S-465 (0.2) 61.8 - Examples 1-5 Formula 1e (41.3) Formula 2a (1.5) S-465 (0.2) 57.0 - Example 1-6 Formula 1f (6.0) Formula 2a (1.5) S-465 (0.2) 92.3 - Example 1-7 Formula 1a (49.9) Formula 2b (1.5) S-465 (0.2) 48.4 - Examples 1-8 Formula 1a (49.9) Formula 2c (1.5) S-465 (0.2) 48.4 - Example 1-9 Formula 1a (49.9) Formula 2d (1.5) S-465 (0.2) 48.4 - Examples 1-10 Formula 1a (49.9) Formula 2e (1.5) S-465 (0.2) 48.4 - Example 1-11 Formula 1a (49.9) Formula 2f (1.5) S-465 (0.2) 48.4 - Examples 1-12 Formula 1a (49.9) Formula 2g (1.5) S-465 (0.2) 48.4 - Example 1-13 Formula 1a (49.9) Formula 2e (1.5) S-465 (0.2) 44.6 5 Comparative Example 1 Formula 1a (49.9) - S-465 (0.2) 49.9 - Comparative Example 2 Formula 1f (6.0) - S-465 (0.2) 93.8 - Comparative Example 3 Formula 1a (49.9) Additives (4.0) S-465 (0.2) 45.9 Comparative Example 4 Formula 1a (49.9) Melamine-based crosslinking agent (1.5) S-465 (0.2) 48.4 -

[Examples 2-1 to 2-17, Comparative Examples 5 to 8] Fine pattern formation

DARC-A125 organic anti-reflection film composition (manufactured by Dongjin Semichem Co., Ltd.) was spin-coated on a silicon wafer and baked at 240°C for 60 seconds to form an organic anti-reflection film with a thickness of 330 Å. ArF photoresist composition DHA-HD150 (manufactured by Dongjin Semichem Co., Ltd.) was applied to a thickness of 1300 Å on top of the formed organic anti-reflection film, and then soft baked at 110°C for 60 seconds. Next, the photoresist film was exposed using an exposure mask with a contact hole (C/H) pattern and 193 nm ArF exposure equipment (ASML 1200B, 0.85NA), and post-baked at 120°C for 80 seconds. After post-baking, it was developed with a 2.38 wt% TMAH (tetramethylammonium hydroxide) aqueous solution to form a 1:1 contact hole (C/H) pattern with a line width (CD) of approximately 90 nm. A scanning electron microscope photograph of the formed photoresist pattern (primary pattern) is shown in Figure 2.

The photoresist pattern coating composition prepared in Examples 1-1 to 1-13 and Comparative Examples 1 to 4 was coated, heated, and developed to form a reduced semiconductor micropattern (Example 2- 1 to 2-17, Comparative Examples 5 to 8). Specifically, after forming the photoresist pattern, each photoresist pattern coating composition is spin coated, heat treated in an oven or hot plate at 100 to 150° C. for 60 to 180 seconds, and then the wafer after the heat treatment process is removed. By developing with ionized water for 10 to 180 seconds, a semiconductor micropattern was formed in which the space pattern portion of the line and space pattern was reduced or the hole size of the contact hole pattern was reduced. The line width of the formed fine pattern was measured using CD-SEM (CG-4000, Hitachi Corporation), and the results are shown in Table 2 below. In addition, scanning electron micrographs of the fine patterns (secondary patterns) formed in Example 2-1 and Comparative Example 4 are shown in FIGS. 3 and 4, respectively, and Examples 2-1 to 2-17 and Comparative Examples 5 to 8. The amount of change in line width is shown in Figure 5. Meanwhile, pattern unevenness occurred in the fine pattern formed in Comparative Example 5.

division Primary pattern CD (nm) For pattern coating
composition Bake temperature and
Time (s, seconds) line width
(nm) line width
amount of change
(nm) pattern
shape Example 2-1 91.06 Example 1-1 130℃ 60s 52.89 38.2 Ο Example 2-2 90.56 Example 1-2 130℃ 60s 56.25 34.3 Ο Example 2-3 91.11 Example 1-3 130℃ 60s 57.11 34.0 Ο Example 2-4 90.98 Example 1-4 130℃ 60s 51.26 39.7 Ο Example 2-5 90.78 Examples 1-5 130℃ 60s 54.48 36.3 Ο Example 2-6 90.91 Example 1-6 130℃ 60s 55.05 35.9 Ο Example 2-7 90.76 Example 1-7 130℃ 60s 50.66 40.1 Ο Example 2-8 91.14 Examples 1-8 130℃ 60s 49.88 41.3 Ο Example 2-9 90.93 Example 1-9 130℃ 60s 61.90 29.0 Ο Example 2-10 90.97 Examples 1-10 130℃ 60s 54.80 36.2 Ο Example 2-11 90.95 Example 1-11 130℃ 60s 58.94 32.0 Ο Example 2-12 90.78 Examples 1-12 130℃ 60s 65.29 25.5 Ο Example 2-13 91.62 Example 1-13 130℃ 60s 59.24 32.4 Ο Example 2-14 90.89 Example 1-1 140℃ 60s 47.77 43.1 Ο Example 2-15 90.61 Example 1-1 150℃ 60s 42.82 47.8 Ο Example 2-16 90.81 Example 1-1 130℃ 90s 48.81 42.0 Ο Example 2-17 91.09 Example 1-1 130℃ 180s 46.99 44.1 Ο Comparative Example 5 91.03 Comparative Example 1 130℃ 60s 66.40 24.6 Δ Comparative Example 6 90.88 Comparative Example 2 130℃ 60s 75.69 15.2 Ο Comparative Example 7 91.15 Comparative Example 3 130℃ 60s 63.90 27.3 Δ Comparative Example 8 90.68 Comparative Example 4 130℃ 60s 73.11 17.6 Δ

In Table 2, the amount of change in line width is determined by forming a primary pattern, measuring the space portion of the primary pattern, coating the coating composition on the patterned wafer, heating (bake), and developing (deionized water) (DI)), then the CD change obtained by measuring the space CD of the developed pattern is indicated. In addition, the pattern shape was confirmed through cross-sectional measurement, and was indicated as O when the vertical pattern was implemented and was good, and as Δ when the surface of the pattern was poor or a vertical orthogonal pattern was not obtained. From the above examples and comparative examples, the pattern coating composition of the present invention uses a polymer having a repeating unit of Formula 1 and an acidic crosslinking agent of Formula 2, thereby increasing pattern shrinkage compared to the case of using only a polymer resin, A stable fine pattern can be formed. When the basic polymer used in Comparative Examples 5 and 7 was used alone or with a basic additive, the optimal pH suggested in the present invention was not satisfied, and the surface of the pattern was uniform due to the influence of the pattern on the primary coating process on the surface of the pattern. You can check what you haven't done. The composition of the present invention does not affect the primary pattern when forming a micropattern using an acidic crosslinking agent, and can form a semiconductor micropattern with a uniform line width distribution (dispersion).

Although the present invention has been described above with reference to specific embodiments, the present invention is not limited thereto, and any conversion, equivalent or substitute included in the spirit and technical scope of the present invention according to the description of the appended claims. It should be interpreted as including.

Claims (11)

5 to 50% by weight of a polymer resin containing a repeating unit represented by the following formula (1),
[Formula 1]

In Formula _{1 ,} R ^* is hydrogen or a methyl group, is a chain-shaped or cyclic saturated or unsaturated hydrocarbon group having 1 to 10 carbon atoms containing hydrogen or 0 to 4 heteroatoms, and R ₁ and R ₂ may be connected to each other to form a ring structure;
0.005 to 2% by weight of an acidic crosslinking agent represented by the following formula (2),
[Formula 2]

In Formula 2, Y is a simple chemical bond or a chain or cyclic saturated or unsaturated hydrocarbon group of 1 to 8 carbon atoms containing 0 to 6 heteroatoms, and R ₃ and R ₄ are each independently a carboxyl group. an acid group (-COOH), a sulfonic acid group (-SO ₃ H), a hydroxy group (-OH), NH ₄ ⁺ O- or NH ₄ OSO ₂ -, and a is an integer of 1 to 3; and
A composition for photoresist pattern coating containing a solvent. The method _of claim ₁ , wherein , sulfur (S) or nitrogen (N), and Y is a hydrocarbon group having 1 to 4 carbon atoms. A composition for photoresist pattern coating. The composition for photoresist pattern coating according to claim 1, wherein the acidic crosslinking agent represented by Formula 2 is used in the form of a salt or a hydrate to which water (H ₂ O) is added. The method of claim 1, wherein Formula 2 is (Formula 2a), H ₂ SO ₄ (Formula 2b), (Formula 2c), (Formula 2d), (Formula 2e), (Formula 2f), A composition for photoresist pattern coating selected from the group consisting of (Formula 2g) The composition for photoresist pattern coating according to claim 1, wherein the polymer resin has a weight average molecular weight of 1,000 to 100,000 g/mol. The composition for photoresist pattern coating according to claim 1, wherein the solvent is water (H ₂ O) or a lower alcohol having 8 or less carbon atoms. delete The composition for photoresist pattern coating according to claim 1, wherein the pH of the composition is 5.5 to 11.0. (a) forming a photoresist pattern (first photoresist pattern) on a substrate;
(b) forming a coating film for pattern reduction by coating the photoresist pattern coating composition of claim 1 on the photoresist pattern; and
(c) A method of forming a fine pattern comprising forming a second photoresist pattern on the first photoresist pattern by removing a portion of the pattern reduction coating film. The method of claim 9, wherein (c) forming the second photoresist pattern includes (c1) heating the pattern reduction coating film to cause the photoresist pattern and the pattern reduction coating film to react, forming the photoresist pattern. forming a solvent-insoluble interfacial layer on the surface; And (c2) developing the pattern reduction coating film with a solvent for the pattern reduction coating film, and removing the portion of the pattern reduction coating film that has not formed the solvent-insoluble interface layer, forming a fine pattern. method. The method of claim 10, wherein the solvent for the coating film for pattern reduction is deionized water.

Images