KR20080076348A - Monomer for photoresist including sulfonyl group, polymer thereof and photoresist composition including the same - Google Patents

Abstract

A photoresist monomer, a photoresist polymer of the monomer, a photoresist composition containing the polymer, and a method for forming a photoresist pattern by using the composition are provided to improve line edge roughness and thermal stability. A photoresist monomer is represented by the formula 1, wherein R* is independently H or a methyl group; Rx and Ry are independently a C1-C10 linear hydrocarbon group or combine together to form a C4-C20 monocyclic or polycyclic saturated hydrocarbon group; R1 is H or a C1-C3 alkyl group; and R2 is a C1-C10 linear or monocyclic saturated hydrocarbon group containing or not containing an amine group. A photoresist composition comprises 100 parts by weight of a polymer of the monomer; 0.1-20 parts by weight of a photoacid generator; and 300-5,000 parts by weight of an organic solvent.

Description

Photoresist monomer, polymer, and photoresist composition comprising the same, and a sulfonyl group.

The present invention relates to a photoresist monomer comprising a sulfonyl group, a polymer and a photoresist composition comprising the same, and more particularly, to an acrylic photoresist monomer including a sulfonyl group having a crosslinking ability, a polymer and a photoresist composition comprising the same. It is about.

In recent years, with the high integration and high precision of semiconductor devices, the formation of ultra-fine photoresist patterns of less than 90 nm in pitch is required in a photo lithography process. Accordingly, while the wavelength of the mass production exposure source is shortened to less than 193 nm, development of a technology for further optimizing and precision of the wafer processing process is in progress. In order to realize such a precise pattern, a photosensitive material having low line edge roughness, low post exposure baking sensitivity, and excellent dry etching resistance is required.

In the process of forming the photoresist pattern, in order to improve the resolution, depth of focus and process margin and to form a more precise pattern, a protecting group which is attached to the side chain of the photoresist polymer and suppresses dissolution in the basic solution An excellent pattern can be obtained by lowering the activation energy of the reaction to be deprotected or by using a polymer whose main chain is decomposed by an exposure light source.

Accordingly, an object of the present invention is to provide a photoresist monomer, a polymer and a photoresist composition comprising the same, which can improve line edge roughness, energy sensitivity and thermal stability.

Still another object of the present invention is to provide a method of forming a photoresist pattern using the photoresist composition.

In order to achieve the above object, the present invention provides a photoresist monomer having a sulfonyl group represented by the following formula (1).

In Formula 1, R ^* are each independently hydrogen or a methyl group; R _x and R _y are each independently linear hydrocarbons having 1 to 10 carbon atoms, or are bonded to each other to form a mono-cyclic or multi-cyclic saturated hydrocarbon group having 4 to 20 carbon atoms; R ₁ is hydrogen or an alkyl group having 1 to 3 carbon atoms; R ₂ is a linear or monocyclic saturated hydrocarbon having 1 to 10 carbon atoms, with or without an amine group.

The present invention also provides a photoresist polymer comprising a repeating unit represented by the following formula (2).

In Formula 2, R ^* , R _x , R _y , R ₁ and R ₂ are as defined in Formula 1.

Hereinafter, the present invention will be described in more detail.

The photoresist monomer containing a sulfonyl group according to the present invention is represented by the following formula (1).

[Formula 1]

,

,

등을 이룰 수 있다. 상기 R₁은 수소 또는 탄소수 1 내지 3의 알킬기, 바람직하게는 메틸기, 에틸기, 프로필기 또는 이소프로필기이다. 상기 R₂는 아민기를 포함하거나 포함하지 않는 탄소수 1 내지 10의 선형 또는 단일환형의 포화탄화수소이며, 바람직하게는 탄소수 1 내지 5의 알킬렌기, 탄소수 1 내지 5의 알킬렌아미노기 등을 예시할 수 있다.In Formula 1, R ^* is each independently hydrogen or a methyl group, R _x and R _y are each independently a linear hydrocarbon having 1 to 10 carbon atoms, or are bonded to each other mono-cyclic (mono-cyclic) having 4 to 20 or It forms a polycyclic saturated hydrocarbon group, preferably R _x and R _y are bonded to each other to form a cycloalkyl group having 5 to 10 carbon atoms, more preferably

,

,

Etc. can be achieved. R ₁ is hydrogen or an alkyl group having 1 to 3 carbon atoms, preferably a methyl group, ethyl group, propyl group or isopropyl group. R ₂ is a linear or monocyclic saturated hydrocarbon having 1 to 10 carbon atoms, or without an amine group, preferably an alkylene group having 1 to 5 carbon atoms, an alkylene amino group having 1 to 5 carbon atoms, and the like. .

The photosensitive monomer represented by Formula 1 according to the present invention, as shown in the following Scheme 1 by the acid catalyst amplification action of the photoacid generator (PAG) by the exposure source, the decomposition is made in the monomer molecule, sulfo Generate nitric acid. Sulfonyl acid generated in this way is connected to the polymer, the acid diffusion is controlled, there is an advantage that can improve the line edge roughness. In addition, since acid is generated in the polymer side chain by the ultraviolet light source, energy sensitivity is increased, and thermal stability is improved by the network structure of the polymer.

The photoresist polymer having a sulfonyl group according to the present invention includes a repeating unit represented by the following formula (2).

[Formula 2]

In Formula 2, R ^* , R _x , R _y , R ₁ and R ₂ are as defined in Formula 1. In the photoresist polymer, the content of the repeating unit represented by Formula 2 is 1 to 99 mol%, preferably 1 to 50 mol% based on the total repeating units constituting the polymer, and constitutes the photoresist polymer. The remaining repeating unit may include one or more repeating units constituting a conventional photoresist polymer. The photoresist polymer according to the present invention may be represented by the following formula (3).

In Formula 3, R ^* , R _x , R _y , R ₁ and R ₂ are as defined in Formula 1, R ₃ is an acid-sensitive protecting group, each independently containing or without an ether group or ester group C _Is an alkyl group or a cycloalkyl group of ₁ to C ₂₀ , a and b represent mole% of each repeating unit with respect to the total repeating units constituting the polymer (ie, 2a + b = 100 mol%), and 2a: b is 1 99 mol%: 1-99 mol%, Preferably 50-99 mol%: 1-50 mol%.

The acid sensitive protecting group (R ₃ ) is a group that can be detached by an acid, and determines whether or not the photoresist material is dissolved in an alkaline developer. Such acid-sensitive protecting groups can be anything as long as they can play such roles, and non-limiting examples include t-butyl, 3-hydroxy tetra hydrofuran, tetrahydro-3-furanmethanol, tetrahydroper Furyl alcohol, 1-methoxypropyl, 1-methoxy-1-methylethyl, 1-ethoxypropyl, 1-ethoxy-1-methylethyl, 1-methoxyethyl, 1-ethoxyethyl, t-part Methoxyethyl, 1-isobutoxyethyl, 2-methoxy ethanol, adamantyl and the like can be exemplified.

More specific examples of the formula (2) is the same as the formula (4).

In Formula 4, R ^* , R _x , R _y , R ₁ and R ₂ are as defined in Formula 1, a, b, c and d is the mole of each repeating unit to the total repeating units constituting the polymer % (I.e., 2a + 2b + 2c + d = 100 mol%), 2a: 2b: 2c: d is 1-97 mol%: 1-97 mol%: 1-97 mol%: 1-97 mol% , Preferably it is 1-60 mol%: 1-60 mol%: 1-50 mol%: 1-10 mol%.

In addition to the monomer having the protecting group (R ₃ ) which is sensitive to the acid, the photosensitive polymer may be a cycloolefin (eg maleic hydride) monomer, other monomers commonly used in the preparation of the photosensitive polymer, a crosslinkable monomer, and the like. It may further include, the content of these auxiliary monomers is usually 0 to 5 mol% based on the total repeating unit. The photosensitive polymer according to the present invention may be a block copolymer or a random copolymer, the weight average molecular weight (Mw) is preferably 3,000 to 20,000, more preferably 3,000 to 15,000. It is preferable that it is 1.0-5.0, and, as for Polydispersity, it is more preferable that it is 1.0-2.2. When the weight average molecular weight and the dispersion degree are outside the above ranges, the physical properties of the photoresist film may be lowered, or the formation of the photoresist film may be difficult, and the contrast of the pattern may be lowered.

Production of the (meth) acrylate photosensitive monomer having a sulfonyl group in the molecule of the present invention is, for example, as shown in Scheme 2 below, a metal sulfonyl compound (Formula 5), an alkyl cyclo oxide compound (Formula 6) ) And (meth) acryloyl chloride in an organic solvent such as dimethylformamide.

Wherein R, R ^*, R _x, R _y, R ₁ and R ₂ are as defined in Formula 1, M is preferably an alkali metal, most preferably a lithium sodium or potassium.

The photosensitive polymer according to the present invention may be prepared by a conventional polymerization reaction using the monomer represented by Formula 1 and other monomers, and as the initiator, a polymerization initiator commonly known in the art may be widely used. Non-limiting examples include azobis (isobutylonitrile) (AIBN) and the like.

The photoresist composition of the present invention includes a photosensitive polymer comprising a monomer represented by the formula (1), a photoacid generator for generating an acid and an organic solvent, and can be prepared by mixing various additives as necessary. The solid content concentration of the prepared photoresist composition is preferably 1 to 30% by weight based on the total photoresist composition, and it is preferable to use this by filtration with a 0.2 μm filter or the like.

The photoacid generator may be used as long as it is a compound capable of generating an acid by light, and non-limiting examples may include onium salt, organic sulfonic acid, or a mixture thereof. The content of the photoacid generator is preferably 0.1 to 20 parts by weight based on 100 parts by weight of the total photoresist polymer. If the photoacid generator is added in less than 0.1 parts by weight, the sensitivity of the photoresist composition to light is lowered. If the photoresist is used in excess of 20 parts by weight, the photoacid generator absorbs a lot of ultraviolet rays and a large amount of acid is generated. There is a risk of poor quality.

As the organic solvent constituting the photoresist composition according to the present invention can be used a wide variety of organic solvents commonly used in the preparation of the photoresist composition, non-limiting examples include ethylene glycol monomethyl ethyl, ethylene glycol monoethyl ether , Ethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether acetate (PGMEA), toluene, xylene, methyl ethyl ketone, cyclohexanone, 2-hydroxypropionethyl, 2-hydroxy 2-methyl Ethyl propionate, ethyl ethoxy acetate, ethyl hydroxy acetate, methyl 2-hydroxy 3-methylbutyrate, methyl 3-methoxy 2-methylpropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxy 2-methylpropionate , Ethyl acetate, butyl acetate, or a mixture thereof can be exemplified. The content of the organic solvent is preferably 300 to 5000 parts by weight based on 100 parts by weight of the total photoresist polymer.

In addition, the photoresist composition of the present invention may further include an organic base, the content of the organic base is 0.01 to 10% by weight. As the organic base, triethylamine, triisobutylamine, triisooctylamine, diethanolamine, triethanolamine or mixtures thereof may be used.

In order to form a photoresist pattern using the photoresist composition of the present invention, first, the photoresist composition is coated on a etched layer such as a silicon wafer or an aluminum substrate using a spin coater to form a photoresist film. After exposing the photoresist film in a predetermined pattern, the exposed photoresist film may be heated and developed to obtain an excellent pattern. As a developing solution used in the developing step, an alkaline aqueous solution in which alkaline compounds such as sodium hydroxide, potassium hydroxide, sodium carbonate and tetramethylammonium hydroxide (TMAH) are dissolved at a concentration of 0.1 to 10% by weight may be used. A proper amount of water-soluble organic solvent and surfactant, such as methanol and ethanol, can be added to the. In addition, after developing with a developing solution, it is washed with ultrapure water.

Hereinafter, the present invention will be described in more detail with reference to specific examples. The following examples are intended to illustrate the present invention more specifically, but the present invention is not limited by the following examples.

Example 1-1 Synthesis of Compound Represented by Chemical Formula 2a

24.6 g (0.1 mol) of methacryloxypropyl sulfonate potassium salt was dissolved in 200 mL of dimethylformamide as a reaction solvent, followed by stirring while maintaining the temperature of the reactor at room temperature. 11.8 g (0.105 mol) of the compound represented by Chemical Formula 1a was slowly added dropwise thereto. After the addition was completed, the reactor was stirred at room temperature for 3 hours. After adding 10 g of triethylamine which is an organic base to the reactor, the temperature of the reactor was cooled to 0 ° C. After diluting 10.5 g (0.1 mol) of methacryloyl chloride in 20 mL of dimethylformamide, it was added dropwise to the reactor and reacted for 12 hours. After the reaction was completed, 300 mL of deionized water was added to the reactor, and extracted three times using 300 mL of dimethyl chloride. The supernatant obtained by extraction was washed several times with water. The obtained organic solution was dried over anhydrous magnesium sulfate, distilled under reduced pressure, and then silica gel column chromatography (dimethyl chloride: hexane = 1: 3) was used to obtain a compound represented by the following Chemical Formula 2a in 35% yield. ¹ H-NMR (CDCl ₃ , internal standard): δ (ppm) 6.10 (CH ₂ , 2H), 5.59 (CH ₂ , 2H), 5.28 (CH, 1H), 4.28 (CH ₂ , 2H), 3.32 ( CH ₂ , 2H), 2.26 (CH ₂ , 2H), 1.91 (CH ₃ , 6H), 1.62 (CH ₂ , 2H), 1.54 (CH ₂ , 2H), 1.49 (CH ₃ , 3H), 1.42 (CH ₂ , 2H), 1.34 (CH ₂ , 2H).

Example 1-2 Synthesis of Compound Represented by Formula 1b

A compound represented by the following Chemical Formula 2b was obtained by the same method as Example 1-1, except for using 16.0 g (0.105 mol) of the compound represented by the formula 1b instead of 11.8 g (0.105 mol) of the compound represented by the formula 1a. Obtained in% yield. ¹ H-NMR (CDCl ₃ , internal standard): δ (ppm) 6.07 (CH ₂ , 2H), 5.52 (CH ₂ , 2H), 5.23 (CH, 1H), 4.25 (CH ₂ , 2H), 3.30 ( CH ₂ , 2H), 2.22 (CH ₂ , 2H), 1.92 (CH ₃ , 6H), 1.61 (CH ₂ , 2H), 1.54 (CH ₂ , 2H), 1.50 (CH ₃ , 3H), 1.52 (CH, 1H), 1.44 (CH, 1H), 1.32 (CH ₂ , 2H), 1.09 (CH ₃ , 6H).

[Formula 2b]

Example 1-3 Synthesis of Compound Represented by Formula 1c

A compound represented by the following Chemical Formula 2c was obtained in the same manner as in Example 1-1, except that 10.3 g (0.105 mol) and the compound represented by Chemical Formula 1c were used instead of the compound 11.8 g (0.105 mol) represented by the chemical formula 1a. Obtained in% yield. ¹ H-NMR (CDCl ₃ , internal standard): δ (ppm) 6.09 (CH ₂ , 2H), 5.60 (CH ₂ , 2H), 5.26 (CH, 1H), 4.25 (CH ₂ , 2H), 3.33 ( CH ₂ , 2H), 2.24 (CH ₂ , 2H), 1.90 (CH ₃ , 6H), 1.72 (CH ₂ , 2H), 1.61 (CH ₂ , 2H), 1.51 (CH ₃ , 3H), 1.45 (CH ₂ , 2H).

Example 1-4 Synthesis of Compound Represented by Chemical Formula 1d

27.5 g (0.1 mol) of methacryloxyamido-t-butyl sulfonate potassium salt was used instead of 24.6 g (0.1 mol) of methacryloxypropyl sulfonate potassium salt. In the same manner as in Example 1-1, a compound represented by the following Chemical Formula 2d was obtained in a yield of 39%. ¹ H-NMR (CDCl ₃ , internal standard): δ (ppm) 7.89 (NH, 1H), 6.09 (CH ₂ , 2H), 5.60 (CH ₂ , 2H), 5.28 (CH, 1H), 3.48 (CH ₂ , 2H), 1.90 (CH ₃ , 6H), 1.61 (CH ₂ , 2H), 1.54 (CH ₂ , 2H), 1.47 (CH ₃ , 3H), 1.40 (CH ₂ , 2H), 1.33 (CH ₂ , 2H), 0.98 (CH ₃ , 6H).

Example 1-5 Synthesis of Compound Represented by Chemical Formula 1e

In the same manner as in Example 1-2, except that 27.5 g (0.1 mol) of methacryloxyamido-t-butyl sulfonate potassium salt was used instead of 24.6 g (0.1 mol) of methacryloxypropyl sulfonate potassium salt. The compound represented by the following Chemical Formula 2e was obtained in a yield of 30%. ¹ H-NMR (CDCl ₃ , internal standard): δ (ppm) 7.91 (NH, 1H), 6.08 (CH ₂ , 2H), 5.54 (CH ₂ , 2H), 5.24 (CH, 1H), 3.50 (CH ₂ , 2H), 1.92 (CH ₃ , 6H), 1.61 (CH ₂ , 2H), 1.50 (CH ₃ , 3H), 1.52 (CH, 1H), 1.44 (CH, 1H), 1.32 (CH ₂ , 2H) , 1.09 (CH ₃ , 6H), 0.94 (CH ₃ , 6H).

Example 1-6 Synthesis of Compound Represented by Chemical Formula 1f

In the same manner as in Example 1-3, except that 27.5 g (0.1 mol) of methacryloxyamido-t-butyl sulfonate potassium salt was used instead of 24.6 g (0.1 mol) of methacryloxypropyl sulfonate potassium salt. The compound represented by the following Chemical Formula 2f was obtained in a yield of 51%. ¹ H-NMR (CDCl ₃ , internal standard): δ (ppm) 7.92 (NH, 1H), 6.10 (CH ₂ , 2H), 5.57 (CH ₂ , 2H), 5.26 (CH, 1H), 3.49 (CH ₂ , 2H), 1.90 (CH ₃ , 6H), 1.72 (CH ₂ , 2H), 1.61 (CH ₂ , 2H), 1.51 (CH ₃ , 3H), 1.45 (CH ₂ , 2H), 0.95 (CH ₃ , 6H).

Example 1-7 Synthesis of Compound Represented by Chemical Formula 1g

41. A compound represented by the following Chemical Formula 2g was obtained by the same method as Example 1-1 except for using 13.3 g (0.105 mol) of the compound represented by the formula 1g instead of 11.8 g (0.105 mol) of the compound represented by the formula 1a. Obtained in% yield. ¹ H-NMR (CDCl ₃ , internal standard): δ (ppm) 6.08 (CH ₂ , 2H), 5.58 (CH ₂ , 2H), 5.29 (CH, 1H), 4.27 (CH ₂ , 2H), 3.29 ( CH ₂ , 2H), 2.24 (CH ₂ , 2H), 1.89 (CH ₃ , 6H), 1.61 (CH ₂ , 2H), 1.54 (CH ₂ , 2H), 1.44 (CH ₂ , 4H), 1.32 (CH ₂ , 2H), 1.01 (CH ₃ , 3H).

Example 1-8 Synthesis of Compound Represented by Chemical Formula 1h

39. A compound represented by the following Chemical Formula 2h was obtained by the same method as Example 1-1 except for using 14.7 g (0.105 mol) of the compound represented by the formula 1h instead of 11.8 g (0.105 mol) of the compound represented by the formula 1a. Obtained in% yield. ¹ H-NMR (CDCl ₃ , internal standard): δ (ppm) 6.09 (CH ₂ , 2H), 5.59 (CH ₂ , 2H), 5.27 (CH, 1H), 4.28 (CH ₂ , 2H), 3.33 ( CH ₂ , 2H), 2.25 (CH ₂ , 2H), 1.91 (CH ₃ , 6H), 1.60 (CH ₂ , 2H), 1.56 (CH ₂ , 2H), 1.52 (CH ₂ , 1H), 1.43 (CH ₂ , 2H), 1.35 (CH ₂ , 2H), 0.98 (CH ₃ , 6H).

Example 2-1 Preparation of Photosensitive Polymer Represented by Chemical Formula 3a (R ^* = CH ₃ )

3.88 g (0.01 mol) of monomers represented by Formula 2a prepared in Example 1-1, 23.43 g (0.1 mol) of 2-methyl-2-adamantyl methacrylate, and 6.81 g of gamma butyrolactammethacrylate ( 0.04 mol), 11.82 g (0.05 mol) of 1-methacryloyloxy-3-hydroxyadamantane and 4.59 g of azobis (isobutyronitrile) (AIBN) were added to the reactor, and the reaction was dried with anhydrous tetrahydrofuran. After dissolving in 100 g (THF), gas was removed using an ampoule as a freezing method, and the degassed reaction was polymerized at 68 ° C. for 24 hours. After the polymerization reaction was completed, the reactant was slowly added dropwise to an excess of diethyl ether, followed by precipitation with THF. The dissolved reactant was reprecipitated in diethyl ether to give 26.7 g of the polymer represented by Chemical Formula 3a. Was obtained in a yield of 58%. The synthesized polymer was analyzed for molecular weight (Mw) and polydispersity (PD) using gel permeation chromatography (GPC) {GPC analysis: Mn = 5,461, Mw = 10,486, PD = 1.92}.

Example 2-2 Preparation of Photosensitive Polymer Represented by Chemical Formula 3b (R ^* = CH ₃ )

A polymer represented by the following Chemical Formula 3b was prepared in the same manner as in Example 2-1 except that 4.29 g of the monomer represented by Chemical Formula 2b was used instead of 3.88 g of the monomer represented by Chemical Formula 2a, at a yield of 60%. {GPC analysis: Mw = 9,812, PD = 1.89}.

Example 2-3 Preparation of Photosensitive Polymer Represented by Chemical Formula 3c (R ^* = CH ₃ )

A polymer represented by the following Chemical Formula 3c was prepared in the same manner as in Example 2-1, except that 3.74 g of the monomer represented by Chemical Formula 2c was used instead of 3.88 g of the monomer represented by Chemical Formula 2a in a yield of 53%. {GPC analysis: Mw = 9,504, PD = 1.90}.

Example 2-4 Preparation of Photosensitive Polymer Represented by Chemical Formula 3d (R ^* = CH ₃ )

A polymer represented by the following Chemical Formula 3d was prepared in the same manner as in Example 2-1 except that 4.18 g of the monomer represented by Chemical Formula 2d was used instead of 3.88 g of the monomer represented by Chemical Formula 2a in a yield of 61%. {GPC analysis: Mw = 9,484, PD = 1.88}.

Example 2-5 Preparation of Photosensitive Polymer Represented by Chemical Formula 3e (R ^* = CH ₃ )

A polymer represented by the following Chemical Formula 3e was prepared in the same manner as in Example 2-1 except that 4.58 g of the monomer represented by Chemical Formula 2e was used instead of 3.88 g of the monomer represented by Chemical Formula 2a, at a yield of 65%. {GPC analysis: Mw = 8,126, PD = 1.85}.

Example 2-6 Preparation of Photosensitive Polymer Represented by Chemical Formula 3f (R ^* = CH ₃ )

A polymer represented by the following Chemical Formula 3f was prepared in the same manner as in Example 2-1 except that 4.03 g of the monomer represented by Chemical Formula 2f was used instead of 3.88 g of the monomer represented by Chemical Formula 2a in a yield of 55%. {GPC analysis: Mw = 8,991, PD = 1.73}.

Example 2-7 Preparation of Photosensitive Polymer Represented by Chemical Formula 3g (R ^* = CH ₃ )

A polymer represented by the following Chemical Formula 3g was prepared in the same manner as in Example 2-1 except that 4.03 g of the monomer represented by Chemical Formula 2g was used instead of 3.88 g of the monomer represented by Chemical Formula 2a, at a yield of 53%. {GPC analysis: Mw = 9,856, PD = 1.86}.

Example 2-8 Preparation of Photosensitive Polymer Represented by Chemical Formula 3h (R ^* = CH ₃ )

A polymer represented by the following Chemical Formula 3h was prepared in the same manner as in Example 2-1 except that 4.17 g of the monomer represented by Chemical Formula 2h was used instead of 3.88 g of the monomer represented by Chemical Formula 2a in a yield of 58%. {GPC analysis: Mw = 9,468, PD = 1.81}.

Comparative Example 1 Preparation of a photoresist composition comprising a photosensitive polymer represented by the following formula (7)

A polymer represented by the following Chemical Formula 7 (a: b: c = 53: 21: 26) was prepared in the same manner as in Example 2-1 except that 3.88 g of the monomer represented by Chemical Formula 2a was not used { GPC analysis: Mw = 10,100, PD = 1.89}.

[Examples 3-1 to 3-8, Comparative Example 2] Exposure Pattern Formation Using Photoresist Composition

2 g of each polymer (Formula 3a to 3h, Formula 7) obtained in Examples 2-1 to 2-8 and Comparative Example 1 together with 0.02 g of triphenylsulfonium triflate and 0.01 g of triethanolamine were added to propylene glycol monomethyl ether. After dissolving in 30 g of acetate (PGMEA), and filtered through a 0.2 ㎛ filter to prepare a photoresist composition.

The photoresist composition thus obtained was spin-coated to a thickness of 3000 on top of the etching layer of the silicon wafer to prepare a photoresist thin film, followed by soft baking for 90 seconds in an oven or hot plate at 130 ° C., and using an ArF laser exposure apparatus having a numerical aperture of 0.6. After exposure, it was baked again at 130 ° C. for 90 seconds. The baked wafer was immersed in a 2.38wt% tetramethylammonium hydroxide (TMAH) aqueous solution for 40 seconds and developed to form a L / S (line / space) pattern of 0.12 mu m. The performance comparison of the photoresist composition is shown in Table 1 below.

Referring to Table 1, the photoresist composition including the photosensitive polymer (Formula 3a to 3h) according to the present invention, unlike the photoresist composition comprising a conventional photosensitive polymer for chemical amplification (Formula 7), by an exposure source Not only the polymer main chain was decomposed by the generated acid catalyst (primary acid), but also sulfonyl acid (secondary acid) was generated at the end of the polymer side chain, thereby showing a lower line edge roughness (LER) value. In particular, when the isopropyl group (R ₁ ) is included in the polymer (Formula 3h) it showed the lowest LER value due to the low activation energy. In addition, the polymer according to the present invention has a network structure, has a higher glass transition temperature (Tg) than the conventional linear polymer, and, accordingly, the thermal stability was superior to the conventional polymer. This thermal stability was excellent as the carbon number of the cyclic hydrocarbon (R) increased in the Example which concerns on this invention.

In addition, as a result of exposing the photoresist composition (Examples 3-1 to 3-8) according to the present invention by contacting the mask and the wafer using an EUV exposure apparatus, a 50 nm identical L / S pattern was successfully formed at a thickness of 1000. It was.

As described above, the photoresist polymer including the sulfonyl group and the composition including the same according to the present invention, the main chain of the polymer is decomposed by the acid generated from the photoacid generator (PAG) in the exposure process by the line edge roughness ( LER) is improved and, as the sulfonyl acid is generated at the end of the polymer side chain by the acid generated from the PAG, the diffusion of the acid is controlled to improve the LER. In addition, since acid is generated in the polymer side chain by the ultraviolet light source, energy sensitivity is increased, and thermal stability is improved by the network structure of the polymer.

Claims (7)

A photoresist monomer represented by the following formula (1). [Formula 1]

In Formula 1, R ^* are each independently hydrogen or a methyl group; R _x and R _y are each independently linear hydrocarbons having 1 to 10 carbon atoms, or are bonded to each other to form a mono-cyclic or multi-cyclic saturated hydrocarbon group having 4 to 20 carbon atoms; R ₁ is hydrogen or an alkyl group having 1 to 3 carbon atoms; R ₂ is a linear or monocyclic saturated hydrocarbon having 1 to 10 carbon atoms, with or without an amine group. According to claim 1, wherein R _x and R _y are bonded to each other to form a cycloalkyl group having 5 to 10 carbon atoms, R ₁ is selected from the group consisting of methyl, ethyl, propyl and isopropyl groups, R ₂ is 1 carbon Photoresist monomer is an alkylene group of 5 to 5 or an alkylene amino group of 1 to 5 carbon atoms. A photoresist polymer comprising a repeating unit represented by the following formula (2). [Formula 2]

In Formula 2, R ^* is each independently hydrogen or a methyl group; R _x and R _y are each independently linear hydrocarbons having 1 to 10 carbon atoms, or are bonded to each other to form a mono-cyclic or multi-cyclic saturated hydrocarbon group having 4 to 20 carbon atoms; R ₁ is hydrogen or an alkyl group having 1 to 3 carbon atoms; R ₂ is a linear or monocyclic saturated hydrocarbon having 1 to 10 carbon atoms, with or without an amine group. The photoresist polymer of claim 3, wherein the photoresist polymer is represented by Formula 3 below. [Formula 3]

In Chemical Formula 3, R ^* , R _x , R _y , R ₁ and R ₂ are as defined in Chemical Formula 2, and R ₃ are each independently a C ₁ to C ₂₀ alkyl group containing or without an ether group or an ester group Or a cycloalkyl group, a and b represent mol% of each repeating unit with respect to the total repeating units constituting the polymer (ie, 2a + b = 100 mol%), and 2a: b is 1 to 99 mol%: 1 ~ 99 mol%. The photoresist polymer of claim 3, wherein the photoresist polymer is represented by the following Formula 4. [Formula 4]

In Formula 4, R ^* , R _x , R _y , R ₁ and R ₂ are as defined in Formula 2, a, b, c and d is the mole of each repeating unit to the total repeating units constituting the polymer % (I.e., 2a + 2b + 2c + d = 100 mol%), 2a: 2b: 2c: d is 1-97 mol%: 1-97 mol%: 1-97 mol%: 1-97 mol% to be. A polymer comprising a monomer represented by Formula 1; Photoacid generators generating acid; And Organic solvents, With respect to 100 parts by weight of the photoresist polymer, the content of the photoacid generator is 0.1 to 20 parts by weight, the content of the organic solvent is 300 to 5000 parts by weight. a) a photoresist polymer comprising a monomer represented by Formula 1; Photoacid generators generating acid; And applying a photoresist composition including an organic solvent on the etched layer to form a photoresist film. b) exposing the photoresist film in a predetermined pattern; c) heating the exposed photoresist film; And d) developing the heated photoresist film to obtain a desired pattern.