KR102448080B1 - Novel compounds and extreme ultraviolet photoresist composition containing the same - Google Patents

Abstract

The present invention relates to a multi-iodine compound for improving the performance of an extreme ultraviolet photoresist, and a light absorption adjuvant containing the same. By providing a novel compound containing multiple iodine as the light absorption adjuvant of the extreme ultraviolet photoresist, the extreme ultraviolet photoresist comprising the compound increases light absorption performance of an extreme ultraviolet resist to improve pattern sensitivity, and also improve line-edge roughness (LER), thereby being able to improve patterning performance of the extreme ultraviolet resist.

Description

Novel compounds and extreme ultraviolet photoresist composition containing the same

The present invention relates to a novel compound and an extreme ultraviolet photoresist composition comprising the same.

There has been a strong demand for higher device densities in semiconductor devices fabricated using photolithography techniques. One of the methods of increasing the number of integrated elements per chip is to reduce a critical dimension of a unit element, which is made possible by applying a lithography technique having a higher resolution. Applying a light source with a short wavelength is the surest way to increase the resolution of lithography technology. Currently, an ArF light source (193 nm) is mainly used. started to apply to

Extreme ultraviolet is a kind of ionizing radiation having a very short wavelength of 13.5 nm, and there is a limitation in that extreme ultraviolet photons are generated with high output and cost is high to apply to a lithography process. Therefore, it is essential to develop a resist technology that can efficiently utilize each extreme ultraviolet photon.

When extreme ultraviolet photons are incident on the resist thin film, secondary electrons are generated through interaction with resist constituent elements. The generated secondary electrons activate a photoacid generator (PAG), a key component of chemically-amplified photoresist (CAR), to generate acid molecules, which are It induces decomposition to induce a change in solubility in the developer. At this time, when tin (Sn), antimony (Sb), iodine (I), etc., which have a large absorption cross-section with respect to extreme ultraviolet photons, are present in the resist molecule, absorption of photons is increased and patterning performance is improved. can be improved (Fig. 1).

However, since conventional organic-based extreme ultraviolet resists are composed of carbon (C), hydrogen (H), oxygen (O) and sulfur (S), the absorption of extreme ultraviolet photons is limited, so this can be improved. Furthermore, it is necessary to add a light absorption aid that can improve patterning performance such as line-edge roughness (LER).

Therefore, it is possible to improve the light absorption performance of the resist and further patterning performance such as line-edge roughness (LER) without causing metal contamination problems in the extreme ultraviolet (EUV) lithography process. There is an urgent need for development.

1. Republic of Korea Patent Publication 10-2014-0047895 (published on April 23, 2014)

It is an object of the present invention to provide a novel compound capable of improving light absorption and patterning performance of a photoresist in an extreme ultraviolet (EUV) lithography process and a method for synthesizing the same.

In addition, another object of the present invention is to provide a light absorption aid comprising the novel compound and a photoresist composition for extreme ultraviolet rays comprising the same.

In addition, the present invention is to provide a method for forming a fine pattern using the photoresist composition for extreme ultraviolet rays.

In order to achieve the above object, the present invention provides a compound represented by the following formula (1).

[Formula 1]

In Formula 1,

R ¹ to R ³ are the same as or different from each other, and hydrogen, halogen, fluorinated alkyl group (perfluoroalkyl), alkyl group, aromatic ring (aryl ring), fluorinated aromatic ring (fluorinated aryl ring), hydroxy (OH) or an ester group thereof [ OC(=O)R ⁴ , R ⁴ is alkyl, fluorinated alkyl, aryl or fluorinated aryl], silyliso[OSiR ⁵ , R ⁵ is alkyl, fluorinated alkyl, aryl or fluorinated aryl], carboxy (COOH) or esters thereof group (COOR ⁶ , R ⁶ is alkyl, fluorinated alkyl, aryl or fluorinated aryl), nitrile group (CN), amide group [C(=O)NR ⁷ , R ⁷ is alkyl, fluorinated alkyl, aryl or fluorinated aryl), Nitro group (NO ₂ ), sulfoxy [S(=O)R ⁸ , R ⁸ is alkyl, fluorinated alkyl, aryl or fluorinated aryl], sulfone group (SO ₂ R ⁹ , R ⁹ is alkyl, fluorinated alkyl, aryl or fluorinated aryl), sulfonic acid (SO ₃ H), sulfonyl ester group (SO ₃ R ¹⁰ , R ¹⁰ is alkyl, fluorinated alkyl, aryl or fluorinated aryl), sulfonyl amide group (SO ₂ NR ¹¹ , R ¹¹ is alkyl, fluorinated alkyl, aryl or fluorinated aryl), tin alkylated (SnR ¹² , R ¹² is alkyl or fluorinated alkyl) and tin arylated (SnR ¹³ , R ¹³ is aryl or fluorinated aryl).

In addition, the present invention provides a light absorption aid for extreme ultraviolet light comprising the compound.

In addition, the present invention provides a method for synthesizing multiple iodinated compounds, characterized in that iohexol is added to a solvent containing a benzaldehyde derivative and a catalyst and reacted to synthesize the compound represented by Formula 1 do.

In addition, the present invention provides an extreme ultraviolet light absorption aid comprising a compound synthesized by the method for synthesizing the multiple iodide compounds.

In addition, the present invention provides an extreme ultraviolet photoresist comprising the light absorption aid.

In addition, the present invention is a first step of applying the photoresist to the substrate; a second process of heat-treating the substrate to form a photoresist film; a third step of placing a mask on the photoresist film and exposing it; and a fourth step of forming a pattern on a substrate by developing the photoresist layer with a developer.

The novel multi-iodine compound prepared by introducing a cyclic acetal structure to Iohexol containing a large number of iodine (I) atoms of the present invention has excellent solubility in conventional photoresist coating solvents, and is produced from a photoacid generator upon exposure to extreme ultraviolet light It can be decomposed through a catalytic reaction by strong acid molecules and regenerated into Iohexol, and can have high solubility in water-based developing solvents.

In addition, the novel compound is mixed with an extreme ultraviolet resist polymer, a photoacid generator (PAG), and an acid quencher and molded into a thin film, and then patterned under extreme ultraviolet irradiation conditions to improve the light absorption performance of the extreme ultraviolet resist. By increasing the pattern sensitivity can be improved, the pattern roughness (line-edge roughness; LER) can also be improved, it is possible to improve the patterning performance of the extreme ultraviolet resist.

1 is a graph showing the absorption cross-sectional area calculated according to the element type in extreme ultraviolet rays.
2 is a view showing a ¹ H NMR graph of ITA-1 synthesized according to Example 1.
3 is a view showing a ¹ H NMR graph of ITA-2 synthesized according to Example 2.
4 is a view showing a ¹ H NMR graph of ITA-3 synthesized according to Example 3.
5 is a graph (contrast curve) showing the change in sensitivity under 248 nm ultraviolet light according to the content change of the multiple iodide compounds ITA-1 and ITA-2 included in the resist thin film.
6 is a table showing SEM images of patterns formed under extreme ultraviolet light according to the contents of ITA-1, ITA-2, and ITA-3 included in the resist thin film.
7 is a table showing SEM images of patterns formed under extreme ultraviolet light according to the content of ITA-2 and the content of photo-decomposable quencher (PDQ) included in the resist thin film.

Hereinafter, the present invention will be described in detail.

The present inventors synthesized a novel compound containing multiple iodine, which is a light absorption aid for extreme ultraviolet photoresists, and extreme ultraviolet photoresists containing these compounds can improve the pattern sensitivity by increasing the light absorption performance of the extreme ultraviolet resist, Pattern roughness (line-edge roughness; LER) is also improved, it was found that the patterning performance of the extreme ultraviolet resist can be improved, thereby completing the present invention.

A typical organic-based EUV resist is composed of carbon (C), hydrogen (H), oxygen (O), and sulfur (S), so that absorption of EUV photons is limited. To improve this, iodine (I), which does not cause metal contamination problems in the extreme ultraviolet lithography process, and has a large absorption cross-section for extreme ultraviolet photons, is included as a major component of the resist thin film. wanted to do

Since iodine (I) is known to have a very large absorption cross-section under extreme ultraviolet irradiation conditions, it was expected that the extreme ultraviolet absorption characteristics of the resist thin film could be greatly improved if applied as an element constituting a resist. .

However, when a large number of iodine atoms are directly bonded to the chemical structure of the existing resist polymer, the solubility characteristics of the polymer are completely changed, so that it is difficult to proceed with the proper development process after exposure. In order to solve this problem, a method of preparing a novel multi-iodide compound containing a large number of iodine atoms and mixing it with a resist polymer was designed to form a thin film. At this time, if the multi-iodide compound can also be decomposed by strong acid molecules generated during exposure and converted into a structure having excellent solubility in an aqueous developer, the development process can proceed more smoothly, so that these properties can also be obtained.

Accordingly, the present invention provides a compound represented by the following formula (1).

[Formula 1]

In Formula 1,

R ¹ to R ³ are the same as or different from each other, and hydrogen, halogen, fluorinated alkyl group (perfluoroalkyl), alkyl group, aromatic ring (aryl ring), fluorinated aromatic ring (fluorinated aryl ring), hydroxy (OH) or an ester group thereof [ OC(=O)R ⁴ , R ⁴ is alkyl, fluorinated alkyl, aryl or fluorinated aryl], silyliso[OSiR ⁵ , R ⁵ is alkyl, fluorinated alkyl, aryl or fluorinated aryl], carboxy (COOH) or esters thereof group (COOR ⁶ , R ⁶ is alkyl, fluorinated alkyl, aryl or fluorinated aryl), nitrile group (CN), amide group [C(=O)NR ⁷ , R ⁷ is alkyl, fluorinated alkyl, aryl or fluorinated aryl), Nitro group (NO ₂ ), sulfoxy [S(=O)R ⁸ , R ⁸ is alkyl, fluorinated alkyl, aryl or fluorinated aryl], sulfone group (SO ₂ R ⁹ , R ⁹ is alkyl, fluorinated alkyl, aryl or fluorinated aryl), sulfonic acid (SO ₃ H), sulfonyl ester group (SO ₃ R ¹⁰ , R ¹⁰ is alkyl, fluorinated alkyl, aryl or fluorinated aryl), sulfonyl amide group (SO ₂ NR ¹¹ , R ¹¹ is alkyl, fluorinated alkyl, aryl or fluorinated aryl), tin alkylated (SnR ¹² , R ¹² is alkyl or fluorinated alkyl) and tin arylated (SnR ¹³ , R ¹³ is aryl or fluorinated aryl).

The halogen may be fluorine, bromine or iodine, preferably iodine.

The fluorinated alkyl group may preferably be trifluoromethyl (CF ₃ ).

The alkyl group may be (C1-C4)alkyl.

The aromatic ring is not particularly limited, but may preferably be phenyl.

The fluorinated aromatic ring may be, but is not limited to, fluorinated phenyl.

The R ¹ to R ³ may be independently hydrogen, iodo, trifluoromethyl, or tin, and in this case, there is an advantage of improving the absorbance for extreme ultraviolet rays.

Preferably, the compound may be selected from the group consisting of compounds of the following Chemical Formulas 1-1 to 1-3.

[Formula 1-1]

[Formula 1-2]

[Formula 1-3]

In order to develop a material with the above characteristics, Iohexol, a water-soluble molecule containing a large number of iodine atoms, was selected and the chemical structure was changed. Since iohexol contains three 1,2-diols in its chemical structure, it has excellent water solubility.

According to an embodiment of the present invention, propylene glycol mono-methyl ether acetate, a resist coating solvent, is formed by forming a cyclic acetal through a chemical reaction with an aldehyde in a 1,2-diol structure. It was confirmed that it had excellent solubility in ether acetate; PGMEA), propylene glycol mono-methyl ether (PGME), and ethyl lactate. In addition, it was confirmed that during extreme ultraviolet exposure, it is decomposed by strong acid molecules derived from the photoacid generator and converted into iohexol with excellent water solubility, which can be easily removed in the developing process (Scheme 1).

[Scheme 1]

In addition, the present invention provides a method for synthesizing multiple iodinated compounds, characterized in that iohexol is added to a solvent containing a benzaldehyde derivative and a catalyst and reacted to synthesize the compound represented by Formula 1 do.

In this case, the benzaldehyde derivative may be a compound represented by the following Chemical Formula 1a.

[Formula 1a]

In Formula 1a,

R is hydrogen, halogen including iodine, fluorinated alkyl group including trifluoromethyl (CF ₃ ), alkyl group including (C1-C4) alkyl group, aryl ring including phenyl, fluorinated including phenyl Aromatic ring (fluorinated aryl ring), hydroxy (OH) or its ester group [OC(=O)R ⁴ , R ⁴ is alkyl, fluorinated alkyl, aryl or fluorinated aryl], silyl is [OSiR ⁵ , R ⁵ is Alkyl, fluorinated alkyl, aryl or fluorinated aryl], carboxy (COOH) or its ester group (COOR ⁶ , R ⁶ is alkyl, fluorinated alkyl, aryl or fluorinated aryl), nitrile (CN), amide group [C(=O) )NR ⁷ , R ⁷ is alkyl, fluorinated alkyl, aryl or fluorinated aryl), nitro group (NO ₂ ), sulfoxy[S(=O)R ⁸ , R ⁸ is alkyl, fluorinated alkyl, aryl or fluorinated aryl], sulfone group (SO ₂ R ⁹ , R ⁹ is alkyl, fluorinated alkyl, aryl or fluorinated aryl), sulfonic acid (SO ₃ H), sulfonyl ester group (SO ₃ R ¹⁰ , R ¹⁰ is alkyl, fluorinated alkyl, aryl or fluorinated aryl), sulfonyl amide groups (SO ₂ NR ¹¹ , R ¹¹ is alkyl, fluorinated alkyl, aryl or fluorinated aryl), tin alkylated (SnR ¹² , R ¹² is alkyl or fluorinated alkyl) and tin arylated (SnR ¹³ , R ¹³ is selected from the group consisting of aryl or fluorinated aryl).

In addition, the catalyst may be one or more selected from the group consisting of toluene sulfonic acid, benzene sulfonic acid, methane sulfonic acid and trifluoromethane sulfonic acid, but is not limited thereto.

According to one embodiment of the present invention, the inventors of the present invention use an acid-decomposable 2-phenyl-1,3-dioxolane (2-phenyl-1,3-) using benzaldehyde in the iohexol backbone. dioxolane) structure was introduced to prepare ITA-1. In addition, 3-iodobenzaldehyde (3-iodobenzaldehyde) was used to synthesize 2-(3-iodophenyl)-1,3-dioxolane [2-(3-iodophenyl)-1,3-dioxolane]. ITA-2 with more iodine was prepared. Finally, using 3-trifluoromethyl benzaldehyde, 2-(3-trifluoromethylphenyl)-1,3-dioxolane [2-(3-trifluoromethylphenyl)-1,3-dioxolane ITA-3 into which ] was introduced was also prepared. In the case of ITA-3, a fluorine atom with a large absorption cross-sectional area for extreme ultraviolet compared to carbon was introduced to confirm the effect.

In addition, the present invention provides a light absorption aid for extreme ultraviolet light comprising the compound or a compound synthesized by the method for synthesizing the multiple iodide compound.

In addition, it provides an extreme ultraviolet photoresist comprising the light absorption aid.

In this case, the photoresist is characterized in that it comprises at least one selected from the group consisting of a base resin, a photoacid generator, an acid diffusion inhibitor and a solvent, and the base resin is an alkali developer by acid generated by the exposure process. The polymer resin having a change in solubility may be, for example, a copolymer including a polyhydroxystyrene-based monomer and an acrylic acid ester-based monomer, but is not limited thereto.

In addition, the photo-acid generator may be included in an amount of 10 to 30 parts by weight, preferably 15 to 25 parts by weight, based on 100 parts by weight of the base resin, and an onium salt-based, diazomethane-based, selected from sulfonium salt-based or iodine salt-based, It is characterized in that at least one selected from the group consisting of oxime, nitrobenzylsulfonate, aminosulfonate, and disulfone, but is not limited thereto.

In addition, the acid diffusion inhibitor may be included in an amount of 5 to 25 parts by weight, preferably 10 to 20 parts by weight, based on 100 parts by weight of the base resin, and a nitrogen-containing organic material selected from amine-based or amide-based, sulfonium salt-based and iodine-containing organic materials. It is characterized in that it is an onium salt-based photodegradable acid diffusion inhibitor selected from the group consisting of salts, but is not limited thereto.

In addition, the solvent is propylene glycol methyl ether acetate (PGMEA), propylene glycol methyl ether (PGME), ethyl lactate (ethyl lactate), cyclohexanone (cyclohexanone), cyclopentanone (cyclopentanone) and gamma butyrolactone (γ -Butyrolactone) is characterized in that at least one selected from the group consisting of, but is not limited thereto.

In addition, the present invention is a first step of applying the photoresist to the substrate; a second process of heat-treating the substrate to form a photoresist film; a third step of placing a mask on the photoresist film and exposing it; and a fourth step of forming a pattern on a substrate by developing the photoresist layer with a developer.

At this time, the heat treatment of the second process is characterized in that it is performed at 100 to 150 ℃ for 30 seconds to 2 minutes, preferably it may be performed at 130 ℃ for 1 minute. In addition, after the third process, a process of heat treatment at 100 to 150° C. for 30 seconds to 2 minutes may be further included, and preferably, it may be performed at 110° C. for 1 minute.

In this case, if the above conditions are exceeded, a photoresist film may not be formed uniformly, which may cause a problem in that a desired pattern is not properly formed during development after exposure.

The present invention relates to the development of a multi-iodide molecular material added to improve the patterning performance of a photoresist material (EUV resist) applied as a patterning material under extreme ultraviolet irradiation. The developed material contains a cyclic acetal that has excellent solubility in resist coating solvents and is changed into a water-soluble structure through a decomposition reaction by an acid catalyst along with a large number of iodine atoms. Based on the molecular tomography (CT) angiography agent containing multiple iodine, three different benzaldehyde derivatives [HC(O)-Ph-R, R = H, I, CF ₃ ] were introduced. A molecular material having a cyclic acetal structure was synthesized. When the developed multi-iodide molecular material is mixed with a resist polymer and a photoacid generator (PAG) and molded into a thin film, the sensitivity and line-edge roughness (line-edge roughness) under extreme ultraviolet patterning conditions compared to the comparative group that does not include it. , LER) showed improved patterning results.

Hereinafter, the present invention will be described in more detail through examples. These examples are only for explaining the present invention in more detail, and it is to those of ordinary skill in the art to which the present invention pertains that the scope of the present invention is not limited by these examples according to the gist of the present invention. it will be self-evident

<Example 1> Synthesis of absorption aid through acetalization with Benzaldehyde

Benzaldehyde (0.78 g, 7.32 mmol) and acid catalyst p -toluenesulfonic acid ( 0.08 g, 0.49 mmol) and toluene (60 cm ³ ) in a round flask (100 cm ³ ) ), and after stirring at room temperature for 10 minutes, Iohexol (1.0 g, 1.22 mmol) was added, and a dean-stark trap and a reflux condenser were connected to 150 ° C. reacted for 8 hours. Then, it was cooled at room temperature for about 1 hour, filtered and concentrated. Then, ethyl acetate was added for extraction, and the ethyl acetate solution was washed with water and a saturated aqueous sodium chloride solution. Then, anhydrous MgSO ₄ was added and stirred to remove moisture in the product. After filtration, the concentrated product was purified through column chromatography (Silica gel, ethyl acetate / hexane = 5 : 1), and a white solid multi-iodide compound (0.56 g, 42%) (hereinafter referred to as 'ITA-1') was recovered (Scheme 2).

[Scheme 2]

The structure of the ITA-1 compound was confirmed through ¹ H NMR (Nuclear Magnetic Resonance) analysis (FIG. 2).

¹ H NMR (400 MHz, DMSO- d 6): δ 1.81 (s, 3H), 3.35-4.49 (s, 15H), 5.66-6.03 (t, 3H), 7.34-7.54 (d, Ar 15H), 8.77 -8.98 (d, NH 2H) .

<Example 2> Synthesis of absorption aid through acetalization with 3-Iodobenzaldehyde

In a round flask (100 cm ³ ), 3-iodobenzaldehyde (1.71 g, 7.32 mmol) and an acid catalyst p -toluenesulfonic acid ( 0.08 g, 0.49 mmol), toluene ) (60 cm ³ ) was added and stirred at room temperature for 10 minutes. Here, Iohexol (1.0 g, 1.22 mmol) was added, and a dean-stark trap and a reflux condenser were connected to react at 150° C. for 8 hours. Then, it was cooled at room temperature for about 1 hour, filtered and concentrated. Then, ethyl acetate was added for extraction, and the ethyl acetate solution was washed with water and a saturated aqueous sodium chloride solution. Then, anhydrous MgSO ₄ was added and stirred to remove moisture in the product. The concentrated product after filtration was purified through column chromatography (Silica gel, ethyl acetate / hexane = 1: 4), and a white solid multi-iodide compound (0.51 g, 29%) (hereinafter referred to as 'ITA-2') was synthesized (Scheme 3).

[Scheme 3]

The structure of the ITA-2 compound was confirmed through ¹ H NMR (Nuclear Magnetic Resonance) analysis (FIG. 3).

¹ H NMR (400 MHz, DMSO- d 6): δ 1.77-1.84 (s, 3H), 3.35-4.56 (s, 15H), 5.65-6.01 (t, 3H), 7.14-7.88 (d, Ar 12H) , 8.78-8.96 (d, NH 2H) .

<Example 3> Synthesis of absorption aid through acetalization with 3-Trifluoromethyl benzaldehyde

In a round flask (100 cm ³ ), 3-trifluoromethyl benzaldehyde (1.27 g, 7.32 mmol) and an acid catalyst p -toluenesulfonic acid ( 0.08 g, 0.49 mmol), After adding toluene (60 cm ³ ), the mixture was stirred at room temperature for 10 minutes. Here, Iohexol (1.0 g, 1.22 mmol) was added, and a dean-stark trap and a reflux condenser were connected to react at 150° C. for 8 hours. Then, it was cooled at room temperature for about 1 hour, filtered and concentrated. Then, ethyl acetate was added for extraction, and the ethyl acetate solution was washed with water and a saturated aqueous sodium chloride solution. Then, anhydrous MgSO ₄ was added and stirred to remove moisture in the product. The concentrated product after filtration was purified through column chromatography (Silica gel, ethyl acetate / hexane = 1: 4), and a white solid multi-iodide compound (0.47 g, 45%) (hereinafter referred to as 'ITA-3') was synthesized (Scheme 4).

[Scheme 4]

The structure of the ITA-3 compound was confirmed through ¹ H NMR (Nuclear Magnetic Resonance) analysis (FIG. 4).

¹ H NMR (400 MHz, DMSO- d 6): δ 1.77-1.84 (s, 3H), 3.34-4.61 (s, 15H), 5.76-6.15 (t, 3H), 7.58-7.90 (t, Ar 12H) , 8.75-9.02 (d, NH 2H) .

<Example 4> Preparation and thin film molding of resist with absorption aid added

100 parts by weight of a copolymer comprising a polyhydroxystyrene-based monomer and an acrylic acid ester-based monomer (Dongjin Semichem), 20 parts by weight of a sulfonium salt-based photoacid generator, 15 parts by weight of a sulfonium salt-based acid diffusion inhibitor, and PGMEA/coating solvent The ITA-based multi-iodide compound synthesized in Examples 1 to 3 was added to a mixture of 9800 parts by weight of PGME and dissolved to prepare resist solutions having various ratios. The prepared solution was spin-coated on a Si substrate coated with an organic under-layer (AL412), and then heated at 130° C. for 1 minute to form a thin film (thickness 35 nm). After exposure to extreme ultraviolet (EUV, wavelength 13.5 nm) Scanner (IMEC, Belgium), post-exposure bake (PEB) was performed at 110° C. for 1 minute, and the development process was performed with 0.26 M TMAH aqueous solution. .

<Experimental Example 1> Solubility analysis of light absorption aid

The solubility of ITA-1, ITA-2, and ITA-3 compounds, which are multiple iodide compounds synthesized in Examples 1 to 3, in a coating solvent and a base developer was confirmed.

Solubility in propylene glycol mono-methyl ether acetate (PGMEA) and propylene glycol mono-methyl ether (PGME), which are commonly used coating solvents for thin film molding of extreme ultraviolet photoresists As a result of the analysis, it was confirmed that all of the ITA-1, ITA-2 and ITA-3 compounds had excellent solubility through the acetalization reaction (Table 1).

In addition, all of the ITA-1, ITA-2 and ITA-3 compounds did not show solubility in a 0.26 M aqueous solution of tetramethylammonium hydroxide (TMAH), which is a standard developing solution for the photolithography process. However, the deacetalization reaction proceeded by strong acid molecules derived from the photogenerator by exposure to extreme ultraviolet light, and it was regenerated into Iohexol with excellent water solubility, thereby showing excellent solubility in TMAH aqueous solution.

Evaluation of solubility properties for three types of light absorption aids in coating solvents absorption aid coating solvent developing solvent PGMEA PGME TMAH 2.38% ITA-1 O O X ITA-2 O O X ITA-3 O O X

<Experimental Example 2> Patterning analysis using a light absorption aid in a KrF (248 nm) light source

Before extreme ultraviolet characteristic evaluation, using a KrF (248 nm) exposure machine, 100 parts by weight of a copolymer comprising a polyhydroxystyrene-based monomer and an acrylic acid ester-based monomer, 20 parts by weight of a sulfonium salt-based photoacid generator, and a sulfonium salt-based acid As a result of evaluating the patterning sensitivity of the resist thin film formed by including 15 parts by weight of diffusion inhibitor and 9800 parts by weight of PGMEA/PGME, ITA-1 compound 3, 6 parts by weight, and ITA-2 compound 3 and 6 parts by weight, respectively, multiple iodine absorption aids It was confirmed that the pattern sensitivity was slightly improved compared to the resist to which was not added (FIG. 5).

<Experimental Example 3> Patterning analysis using a light absorption aid in extreme ultraviolet (13.5 nm) light source

100 parts by weight of a copolymer using polyhydroxystyrene-based and acrylic acid ester-based monomers, 20 parts by weight of a sulfonium salt-based photoacid generator, and 15 parts by weight of a sulfonium salt-based acid diffusion inhibitor for the multi-iodide compound prepared according to Examples 1 to 3 , After forming a thin film with a thickness of 35 nm together with 9800 parts by weight of PGMEA/PGME, exposure using an extreme ultraviolet scanner (wavelength 13.5 nm), post-exposure bake (PEB) at 110 ℃, development using 0.26 M TMAH aqueous solution As a result, it was observed that the pattern roughness (LER) was decreased, but the pattern sensitivity was rather deteriorated (Table 2, FIG. 6).

Pitch 18L36P Sample ref. [Without ITA] ITA-1:
3 parts by weight ITA-1:
6 parts by weight ITA-2:
3 parts by weight ITA-2:
6 parts by weight ITA-3:
3 parts by weight ITA-3:
6 parts by weight EOP (mJ) 57.52 59.71 61.66 59.32 60.77 57.75 59.65 LER (nm) 2.41 2.25 2.22 2.52 2.35 2.33 2.32 EL(%) 8.06% 8.30% 8.84% 8.22% 8.48% 8.56% 8.62% DOF (nm) 80 80 60 80 80 80 80

In Table 2, EL means Energy Latitude, DOF means Depth of focus, Pitch 18L36P means pattern width (L) is 18 nm, the distance between patterns is 18 nm, and one pattern width and distance (P) between patterns means 36 nm. At this time, EL is a value for confirming the amount of CD (pattern line width) change according to the energy change, and the larger the value, the better the process margin.

This is because the amide linkage present in the ITA-based compound is decomposed when irradiated with extreme ultraviolet light to form a basic component, and this component acts as an acid diffusion inhibitor (quencher), suggesting that the pattern sensitivity is somewhat deteriorated became

In order to confirm the potential of the ITA-based multi-iodide compound to act as an acid diffusion inhibitor, the content of ITA-2, which has a high improvement in properties in Table 2, was maintained at 6 and 12 parts by weight in the resist, and the amount of the acid diffusion inhibitor (9.1 parts by weight, 8.5 parts by weight) was reduced to proceed with patterning.

In general, if the content of the acid diffusion inhibitor is reduced, the pattern sensitivity tends to deteriorate, but ITA-2 rather improved the pattern sensitivity while lowering the EOP (Energy of optimum) value, and also improved the pattern roughness (LER). It was confirmed that both were improved (Table 3, FIG. 7).

Pitch 18L36P Sample ref.
[Without ITA] ITA-2:
6 parts by weight ITA-2:
6 parts by weight ITA-2:
12 parts by weight ITA-2:
12 parts by weight acid diffusion inhibitor 15 parts by weight 15 parts by weight 8.5 parts by weight 15 parts by weight 8.5 parts by weight EOP (mJ) 57.52 60.77 56.24 65.69 55.92 LER (nm) 2.41 2.35 2.32 2.15 2.12 EL(%) 8.06% 8.48% 8.56% 8.95% 8.91% DOF (nm) 80 80 80 80 60

Therefore, the ITA-2 compound to which iodine was additionally introduced among the light absorption aids improved the pattern sensitivity by increasing the light absorption performance of the extreme ultraviolet resist, and the line-edge roughness (LER) was also improved, so that the patterning of the extreme ultraviolet resist was improved. It was confirmed that the performance could be improved.

Claims (6)

A compound represented by the following formula (1):
[Formula 1]

In Formula 1,
R ¹ to R ³ are the same as or different from each other, and hydrogen, halogen, fluorinated alkyl group (perfluoroalkyl), alkyl group, aromatic ring (aryl ring), fluorinated aromatic ring (fluorinated aryl ring), hydroxy (OH) or an ester group thereof [ OC(=O)R ⁴ , R ⁴ is alkyl, fluorinated alkyl, aryl or fluorinated aryl], silyliso[OSiR ⁵ , R ⁵ is alkyl, fluorinated alkyl, aryl or fluorinated aryl], carboxy (COOH) or esters thereof group (COOR ⁶ , R ⁶ is alkyl, fluorinated alkyl, aryl or fluorinated aryl), nitrile group (CN), amide group [C(=O)NR ⁷ , R ⁷ is alkyl, fluorinated alkyl, aryl or fluorinated aryl), Nitro group (NO ₂ ), sulfoxy [S(=O)R ⁸ , R ⁸ is alkyl, fluorinated alkyl, aryl or fluorinated aryl], sulfone group (SO ₂ R ⁹ , R ⁹ is alkyl, fluorinated alkyl, aryl or fluorinated aryl), sulfonic acid (SO ₃ H), sulfonyl ester group (SO ₃ R ¹⁰ , R ¹⁰ is alkyl, fluorinated alkyl, aryl or fluorinated aryl), sulfonyl amide group (SO ₂ NR ¹¹ , R ¹¹ is alkyl, fluorinated alkyl, aryl or fluorinated aryl), alkylated tin (SnR ¹² , R ¹² is alkyl or fluorinated alkyl) and arylated tin (SnR ¹³ , R ¹³ is aryl or fluorinated aryl). The method of claim 1,
The compound is a compound, characterized in that selected from the group consisting of compounds of formulas 1-1 to 1-3:
[Formula 1-1]

[Formula 1-2]

[Formula 1-3]

An extreme ultraviolet photoresist composition comprising at least one selected from the group consisting of a light absorption aid containing the compound of claim 1, a photoacid generator, an acid diffusion inhibitor, and a solvent. 4. The method of claim 3,
The photo-acid generator is selected from the group consisting of sulfonium salt-based and iodine salt-based onium salt-based; diazomethane; oxime; nitrobenzylsulfonate; aminosulfonate; And disulfone-based photoresist composition for extreme ultraviolet, characterized in that at least one selected from the group consisting of. 4. The method of claim 3,
The acid diffusion inhibitor is a nitrogen-containing organic material selected from the group consisting of amine-based and amide-based; and onium salts selected from the group consisting of sulfonium salts and iodine salts; extreme ultraviolet photoresist composition selected from the group consisting of. 4. The method of claim 3,
The solvent is propylene glycol methyl ether acetate (PGMEA), propylene glycol methyl ether (PGME), ethyl lactate, cyclohexanone, cyclopentanone, and gamma butyrolactone (γ-butyrolactone). Lolactone), characterized in that at least one selected from the group consisting of extreme ultraviolet photoresist composition.

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