WO2011014011A2 - Photoresist composition comprising a crosslinkable curing substance - Google Patents

Abstract

Disclosed is a photoresist composition comprising a crosslinkable curing substance, able to form a pattern-protecting film on the surface of a photoresist pattern by first forming a photoresist pattern and then heating or exposing to light and heat, in a pattern-forming method employing the double patterning technique. The photoresist composition comprises: from 3 to 30 wt.% of a light-sensitive polymer; from 0.5 to 75 parts by weight of a crosslinking curing agent or agents represented by Chemical formula 1 and/or Chemical formula 2 of Claim 1, with respect to 100 parts by weight of the light-sensitive polymer; from 0.05 to 15 parts by weight of a photoacid generator, with respect to 100 parts by weight of the light-sensitive polymer; and a balance of solvent.

Description

Photoresist Composition Including Crosslinkable Curing Material

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photoresist composition, and more particularly, in a pattern formation method using double patterning technology (DPT), the photoresist pattern is formed on the surface of the photoresist pattern by heating or exposure and heating after the formation of the photoresist pattern. A photoresist composition comprising a crosslinkable curable material capable of forming a pattern protective film.

In order to process a semiconductor wafer or display glass into a semiconductor chip or display element, the designed circuit structure must be implemented on the semiconductor wafer or display glass through a photolithography process. As the integration of circuits increased, high resolution patterning was required in the photolithography process, using short wavelength light as an exposure source, which is a major parameter determining resolution, or filling a liquid having a refractive index larger than air between the photoresist and the lens. High resolution patterning has been made possible by using a method such that the numerical aperture (NA) is larger than 1, or an additional process is used to reduce the process variable k ₁ value to 0.3 or less. For example, in a semiconductor wafer processing process that requires high resolution, a KrF laser light having a wavelength of 248 nm is used for manufacturing a 200-90 nm class device, and a pattern resolution of 90-60 nm is obtained. The semiconductor chip is produced using an ArF laser having an exposure source wavelength of 193 nm. In order to obtain a 60 to 40 nm ultra-fine pattern resolution, an exposure process is performed by filling DI water having a refractive index of 1.34 instead of air having a refractive index of 1 between the photosensitive film coated on the wafer and the projection lens, that is, a lens. Devices are produced using an immersion lithography process, a method of making aberrations greater than one.

The technology being developed to manufacture 30 nm devices is a double patterning technology (DPT), which is a modification of the conventional single photolithography process, which repeats the existing single process twice and process variable k _1. By decreasing the value to 0.25 or less, it is a technique of forming a desired ultrafine pattern. As a method of reducing the process variable as described above, the exposure process is performed twice and a double exposure patterning method of obtaining a desired resolution pattern and the exposure process are performed once, and then the spacer is chemically vaporized on the sacrificial film pattern. There is a spacer patterning technology (SPT) which is formed by vapor deposition (CVD) and removes the sacrificial film to obtain a pattern of a desired resolution.

When the line pattern is formed by the double exposure patterning method, a first photoresist pattern having a line and space spacing of 1: 3 is formed on the first photoresist film by first exposure and development, and the water-soluble film is coated and heated to form a line pattern. After hardening (protective film formation) by crosslinking the surface of the primary photoresist pattern, the secondary photoresist film is coated on the primary photoresist pattern on which the protective film is formed, and the second photoresist pattern is subjected to the second exposure and development. By forming, a pattern with a line and space interval of 1: 1 is formed, and a hard mask (protective film) is subjected to dry etching to form a final pattern. In order to protect the primary photoresist pattern when forming the secondary photoresist pattern, the entire patterning process is complicated because the protective film must be formed by coating and heating (crosslinking) the water soluble layer on the primary photoresist pattern. There is a drawback to increased workload.

Accordingly, an object of the present invention is to provide a photoresist composition comprising a crosslinkable curable material capable of forming a pattern protective film on the surface of the photoresist pattern by heating or exposing and heating after the photoresist pattern is formed.

In order to achieve the above object, the present invention, the photosensitive polymer 3 to 30% by weight; 0.5 to 75 parts by weight of a crosslinking curing agent selected from the group consisting of a compound represented by the following Chemical Formula 1, a compound represented by the following Chemical Formula 2, and a mixture thereof, based on 100 parts by weight of the photosensitive polymer; 0.05 to 15 parts by weight of a photoacid generator based on 100 parts by weight of the photosensitive polymer; And a remaining solvent, wherein the pattern protective film can be formed on the surface of the photoresist pattern by heating or exposing and heating after forming the photoresist pattern.

[Formula 1]

[Formula 2]

In Formulas 1 and 2, R ₁ , R ₃ and R ₄ are each independently a saturated or unsaturated hydrocarbon group having 1 to 25 carbon atoms or a linear or cyclic structure containing 0 to 20 hetero elements, and R ₂ And R ₅ are each independently a saturated or unsaturated hydrocarbon group having 1 to 20 carbon atoms or a linear or cyclic structure containing 0 to 10 hetero elements.

In addition, the present invention, 3 to 30% by weight of the photosensitive polymer selected from the group consisting of a polymer represented by the following formula (4), a polymer represented by the following formula (5) and mixtures thereof; 0.05 to 15 parts by weight of a photoacid generator based on 100 parts by weight of the photosensitive polymer; And a remaining solvent, wherein the pattern protective film can be formed on the surface of the photoresist pattern by heating or exposing and heating after forming the photoresist pattern.

[Formula 4]

[Formula 5]

In Chemical Formulas 4 and 5, R ₁ , R ₂ , R ₃ and R ₄ are as defined in Chemical Formulas 1 and 2, and R ₆ , X, Y, Z, a, b and c are as defined in Chemical Formula 3 below. And m and n are mole% of each repeating unit with respect to the entire monomer constituting the polymer, m is 1 to 40 mole%, and n is 1 to 40 mole%.

In addition, the present invention, using the photoresist composition, forming a first photoresist pattern on the substrate; Heating the first photoresist pattern to form a pattern protection film; Forming a second photoresist film on the substrate on which the first photoresist pattern and the pattern protection film are formed using a photoresist composition; And applying a lithography process to the second photoresist film to form a second photoresist pattern between the first photoresist patterns.

The photoresist composition comprising a crosslinkable curable material according to the present invention is prepared by copolymerizing a thermal base generator (TBG) or a photo base generator (PBG) with a photosensitive polymer as a crosslinkable curable material. Or as incorporated into a photoresist composition by itself, in a pattern formation method using double patterning technology (DPT), after forming the primary photoresist pattern, the primary photoresist pattern by heating or exposure and heating A pattern protective film can be formed on the surface. Therefore, the method for forming a fine pattern using the photoresist composition does not require a water-soluble film coating process for forming a pattern protective film, so that the process can be simplified and economically advantageous.

1 is a view for explaining a photoresist pattern forming process using a photoresist composition according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail.

The photoresist composition comprising the crosslinkable curable material according to the present invention may be a pattern protective film formed on the surface of the photoresist pattern by heating or exposing and heating after the photoresist pattern is formed. A crosslinking curing agent, a photoacid generator, and a solvent selected from the group consisting of a compound represented, a compound represented by the following Chemical Formula 2, and a mixture thereof are included.

Formula 1

Formula 2

In Chemical Formulas 1 and 2, R ₁ , R ₃ and R ₄ are each independently a saturated or unsaturated hydrocarbon group having 1 to 25 carbon atoms or a linear or cyclic structure containing 0 to 20 hetero elements, preferably , A saturated or unsaturated hydrocarbon group having 1 to 20 carbon atoms or a linear or cyclic structure containing 0 to 10, for example, 1 to 3 hetero elements such as oxygen (O) and nitrogen (N) Alkyl groups), and R ₂ and R ₅ are each independently a saturated or unsaturated hydrocarbon group having 1 to 20 carbon atoms or a linear or cyclic structure containing 0 to 10 hetero elements, preferably nitrogen and oxygen. It is a saturated or unsaturated hydrocarbon group (for example, an alkyl group) of the C1-C15 linear or cyclic structure containing 0-5, for example, 1-3, such hetero elements.

As the photosensitive polymer used in the present invention, a conventional photosensitive polymer may be used, and a photosensitive polymer (base polymer) represented by the following Chemical Formula 3 may be preferably used.

Formula 3

In Chemical Formula 3, R ₆ is each independently hydrogen or a methyl group, and X, Y and Z are each independently a saturated or saturated chain or cyclic structure having 1 to 25 carbon atoms containing 0 to 20 hetero elements. Unsaturated hydrocarbon groups. Preferably, X is a saturated or unsaturated chain or cyclic structure of 1 to 20 carbon atoms containing 0 to 10, for example, 1 to 3, heteroatoms such as oxygen (O) and nitrogen (N). A hydrocarbon group (for example, an alkyl group), Y is a lactone group and 3 to 20 carbon atoms containing 0 to 10, for example, 1 to 3, heteroatoms such as oxygen (O) and nitrogen (N); For example, a saturated or unsaturated hydrocarbon group having 4 to 15 carbon atoms in a linear or cyclic structure (in the above definition of Y, the carbon number is the total carbon number including the lactone moiety, and for example, Y is the lactone group alone or the lactone moiety). Z may include an alkyl group containing 0 to 10, for example, 1 to 5 hetero atoms, such as oxygen (O) or nitrogen (N), substituted with a hydroxy group or a hydroxyl group and a halogen group. Saturated or unsaturated carbonization of 1-20 chain or cyclic structure Is desired (e. G., Alkyl group). a, b and c are mol% of each repeating unit with respect to the total monomers (repeating units) constituting the polymer, a is 10 to 90 mol%, preferably 30 to 50 mol%, b is 0 to 60 mol %, Preferably 0 to 40 mol%, more preferably 1 to 20 mol%, c is 0 to 60 mol%, preferably 0 to 20 mol%, more preferably 1 to 10 mol%, Preferably, at least one of b and c is at least 0 mol%. If the mole% of the repeating unit is out of the above range, the physical properties of the photoresist film may be degraded, or the formation of the photoresist film may be difficult, and the contrast of the pattern may be reduced. Typically, the weight average molecular weight (Mw) of the photosensitive polymer is 2,000 to 20,000, preferably 3,000 to 12,000.

Specific examples of the X,

)은 연결부(connecting bond)를 나타낸다).And the like (where the bend line (

Denotes a connecting bond).

Specific examples of the Y,

)은 연결부(connecting bond)를 나타낸다).And the like (where the bend line (

Denotes a connecting bond).

Specific examples of the Z,

)은 연결부(connecting bond)를 나타낸다).And the like (where the bend line (

Denotes a connecting bond).

The content of the photosensitive polymer is 3 to 30% by weight, preferably 4 to 10% by weight based on the total photoresist composition. If the content of the photosensitive polymer is less than 3% by weight, the formation of the photoresist film and the pattern may be difficult. If the content of the photosensitive polymer is more than 30% by weight, the thickness distribution of the pattern formed on the wafer may be uneven. The photosensitive polymer used in the conventional photolithography process is decomposed by an acid generated in the photolithography process to generate a carboxylic acid group. For example, the photosensitive polymer represented by Chemical Formula 3 is generated from a photoacid generator. In reaction with the acid, X, Y and / or Z may be de-protected or the lactone group of Y may be ring-opened to produce a carboxylic acid group.

The crosslinking curing agent (crosslinkable curing material) used in the present invention is a thermal base generator (TBG) or a photobase generator (photobase generator) in which a primary amine can be formed at the end by heating and / or exposure. base generator: PBG), wherein the primary amine is crosslinked and cured with a carboxylic acid group in the photosensitive polymer on the surface of the photoresist pattern, so that it does not dissolve in the developer or the resist solution, thereby preventing mixing with the secondary photoresist film and A pattern protective film capable of improving the roughness of the pattern is formed. The crosslinking curing agent includes an amide or oxime structure, and a compound represented by Formula 1, a compound represented by Formula 2, or a mixture thereof may be used.

Specific examples of the compound represented by Formula 1,

 Etc. can be illustrated.

Specific examples of the compound represented by Formula 2,

Etc. can be illustrated.

The crosslinking curing agent is usually heated to 130 to 200 ℃, preferably 140 to 180 ℃, or through the usual exposure process, can produce the primary amine (-NH ₂ ) at both ends (Scheme 1) And Scheme 2), for example, a carboxylic acid (photosensitive polymer (Formula 3) of the photosensitive polymer present on the surface of the primary amine and the photoresist pattern at a temperature of 130 to 200 ℃, preferably 140 to 180 ℃ X, Y and / or Z of the de) (protected), or a carboxylic acid group formed by the ring-opening group of Y is randomly bonded to induce crosslinking and curing of the photosensitive polymer (polymer It is possible to form a pattern protective film on the inter-bond, intra-polymer bond and / or single bond, see Scheme 3 below), and the pattern surface.

Scheme 1

Scheme 2

Scheme 3

In Schemes 1 to 3, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , a, b, and c are as defined in Chemical Formulas 1 to 3 above.

The content of the crosslinking curing agent is 0.5 to 75 parts by weight, preferably 1 to 50 parts by weight, based on 100 parts by weight of the photosensitive polymer. When the content of the crosslinking curing agent is less than 0.5 parts by weight based on 100 parts by weight of the photosensitive polymer, curing on the surface of the photoresist may not be sufficient, and a pattern protective film may not be generated. It may act and inhibit the formation of a fine pattern.

The photoacid generator (PAG) used in the present invention can be used without limitation as long as it is a compound capable of generating an acid by light. For example, a sulfonium salt or an iodonium salt compound, a mixture thereof, and the like can be used. have. Preferably, phthalimidotrifluoro methanesulfonate, dinitrobenzyltosylate, n-decyl disulfone, naphthylimidotrifluoro methanesulfonate ), Diphenyl iodide triflate, diphenyl iodo salt nonaplate, diphenyl iodo salt hexafluorophosphate, diphenyl iodo salt hexafluoroarsenate, diphenyl iodo salt hexafluoroantimonate, diphenyl paramethoxyphenylsulfonium Triflate, diphenyl paratoluenylsulfonium triflate, diphenyl parabutyl butyl phenyl sulphonium triflate, diphenyl paraisobutyl phenyl sulphonium triflate, triphenylsulfonium triflate, tris para tertiary butyl phenyl sul Phonium Triflate, Diphenyl Paramethoxyphenylsulfonium Nonaplate, Diphenyl Paratolue Sulfonium nona plate, diphenyl parabutyl butyl phenyl sulfonium nona plate, diphenyl paraisobutyl phenyl sulfonium nona plate, triphenyl sulfonium nona plate, trisparabutyl butylphenyl sulfonium nona plate, hexafluoro ar Photoacid generators, such as a cenate, a triphenylsulfonium hexafluoro antimonate, a dibutyl naphthylsulfonium triflate, and mixtures thereof, can be used. The content of the photoacid generator is 0.05 to 15 parts by weight, preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the photosensitive polymer. When the content of the photoacid generator is less than 0.05 part by weight with respect to 100 parts by weight of the photosensitive polymer, the sensitivity of the photoresist to light is weakened. When the amount of the photoacid generator exceeds 15 parts by weight, the photoacid generator absorbs a lot of ultraviolet rays and a large amount of acid is generated. There is a fear that the cross section of the pattern may be poor.

As a solvent used for this invention, the organic solvent used for a normal photoresist composition can be used without a restriction | limiting, For example, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoacetate, diethylene glycol , Diethylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, propylene glycol, propylene glycol monoacetate, toluene, xylene, methyl ethyl ketone, methyl isoamyl ketone, cyclohexanone, dioxane, methyl lactate, ethyl Lactate, methylpyruvate, ethylpyruvate, methylmethoxypropionate, ethylethoxypropionate, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl 2-pyrrolidone, 3-ethoxyethylpropionate, 2-heptanone, gamma-butyrolactone, 2-hydroxypropionethyl, 2-hydroxy ethyl 2-methylpropionate, ethoxy Ethyl acetate, ethyl hydroxy acetate, methyl 2-hydroxy 3-methylbutyrate, methyl 3-methoxy 2-methylpropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxy 2-methylpropionate, ethyl acetate, Solvents selected from the group consisting of butyl acetate and the like can be used alone or in combination of two to four. The content of the solvent is the remainder except for the photosensitive polymer, the crosslinking curing agent, the photoacid generator and the like with respect to 100% by weight of the total photoresist composition.

In addition, the photoresist composition comprising a crosslinkable curable material according to the present invention is a photosensitive polymer selected from the group consisting of a polymer represented by the following formula (4), a polymer represented by the following formula (5), and mixtures thereof, the photoacid generator And the solvent.

Formula 4

Formula 5

In Chemical Formulas 4 and 5, R ₁ , R ₂ , R ₃ and R ₄ are the same as defined in Chemical Formulas 1 and 2, and R ₆ , X, Y, Z, a, b, and c are the same as defined in Chemical Formula 3. M and n are mole% of each repeating unit with respect to the total monomers (repeating units) constituting the polymer, and m is 1 to 40 mole%, preferably 3 to 20 mole%, more preferably 5 to 15 Mol%, n is 1 to 40 mol%, preferably 3 to 20 mol%, more preferably 5 to 15 mol%. Here, when the mole% of the repeating units m and n is less than 1 mole%, curing on the surface of the photoresist pattern may be insufficient, and a pattern protective film may not be produced. When the mole% of the repeating units m and n exceeds 40 mole%, There is a possibility that the lowering or the formation of the photoresist film is difficult and the contrast of the pattern is lowered. The weight average molecular weight (Mw) of the polymer represented by the formula (4) and the polymer represented by the formula (5) is 2,000 to 20,000, preferably 3,000 to 10,000.

The polymers represented by Formulas 4 and 5, as the photosensitive polymer and the crosslinking curing agent at the same time, a repeating unit (m repeating unit of the formula (4) or oxime (amide, -NH-CO-)) The repeating unit (n repeating unit of Formula 5) containing an oxime) group is introduced into the photosensitive polymer chain. The repeating unit portion of the photosensitive polymer has the same mechanism as the above-mentioned crosslinking curing agent, and is heated to 130 to 200 ° C, preferably 140 to 180 ° C, or through a conventional exposure process, at the end of the primary amine (-NH ₂ ) And crosslinking of the photosensitive polymer at a temperature of 130 to 200 ° C, preferably 140 to 180 ° C, by combining the primary amine and the carboxylic acid of the photosensitive polymer on the surface of the photoresist pattern. And hardening can be induced and a pattern protective film can be formed in a pattern surface.

Specific examples of the monomer capable of forming a repeating unit containing the amide (amide, —NH—CO—) may include the following monomers.

등을 예시할 수 있다.In addition, specific examples of the monomer capable of forming a repeating unit including an oxime group include

Etc. can be illustrated.

The content of the photosensitive polymer selected from the group consisting of the polymer represented by the formula (4), the polymer represented by the formula (5), and mixtures thereof is 3 to 30% by weight, preferably 4 to 30% based on the total photoresist composition. 10% by weight. If the content of the photosensitive polymer is less than 3% by weight, the formation of the photoresist film and the pattern may be difficult. If the content of the photosensitive polymer is more than 30% by weight, the thickness distribution of the pattern formed on the wafer may be uneven.

The content of the photoacid generator is 0.05 to 15 parts by weight, preferably 100 parts by weight based on 100 parts by weight of the photosensitive polymer selected from the group consisting of the polymer represented by the formula (4), the polymer represented by the formula (5), and mixtures thereof. , 0.1 to 10 parts by weight. When the content of the photoacid generator is less than 0.05 part by weight with respect to 100 parts by weight of the photosensitive polymer, the sensitivity of the photoresist to light becomes weak. There is a possibility that the cross section of the pattern may be poor. The content of the solvent is remaining in the entire photoresist composition except for the photosensitive polymer, the photoacid generator and the like.

The photoresist composition according to the present invention may further include other conventional photosensitive polymers, basic acid diffusion regulators (basic compounds, Quencher), polymers including fluoro alcohols represented by the following Chemical Formula 7, as necessary. . As the basic acid diffusion regulator, a basic acid diffusion regulator used in a conventional photoresist composition may be used without limitation, for example, triethylamine, trioctylamine, triisobutylamine, triisooctylamine, di Ethanolamine, triethanolamine, 2-Piperidine ethanol, a mixture thereof, and the like may be used, and if necessary, a basic acid diffusion regulator of a polymer type represented by the following Chemical Formula 6 may be used.

Formula 6

In Formula 6, R ₆ , X, Y and Z are as defined in Formula 3, R ₁₀ is 0 to 10 hetero elements, preferably nitrogen (N), oxygen (O), sulfur (S) A saturated or unsaturated hydrocarbon group having 1 to 20, preferably 2 to 15, linear or cyclic structures containing 1 to 8, preferably 2 to 5 hetero elements, such as R ₁₁ and R ₁₂ is each independently hydrogen or a saturated or unsaturated hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 10 carbon atoms, containing 0 to 5, preferably 2 to 4 hetero atoms. (Eg, an alkyl group), and d, e, f, and g are mole% of each repeating unit with respect to the total monomers (repeating units) constituting the polymer, and d is 5 to 75 mole%, preferably 5 to 50 mol%, more preferably 10-25 mol%, and e, f, and g are each independently 0-95 mol %, Preferably 5 to 70 mol%, at least one of e, f and g is greater than 0 mol%.

The weight average molecular weight (Mw) of the polymer type basic acid diffusion regulator is 2,000 to 20,000, preferably 2,500 to 15,000, and polydispersity index (PDI) is 1.0 to 2.0, preferably 1.2 to 1.8. When the weight average molecular weight and the dispersion degree are out of the above ranges, there is a fear that the solubility with the solvent is lowered or the contrast of the pattern is lowered. When using the basic acid diffusion regulator, the content thereof is 0.1 to 5 parts by weight, preferably 0.5 to 2 parts by weight based on 100 parts by weight of the photosensitive polymer. When the content of the basic acid diffusion regulator is out of the above range, a large amount of acid may be generated to obtain a pattern having a bad cross section, and the contrast of the pattern may be lowered.

The polymer represented by the following formula (7) increases the hydrophobicity of the surface of the resist film during a conventional immersion process, thereby suppressing the elution of the material inside the resist film into the immersion solvent, or improving water harvestability. As used for the purpose of the present invention, it may be included in a photoresist composition applied to an immersion process.

Formula 7

In Formula 7, R ₆ , X, Y and Z are as defined in Formula 3, R ₁₃ is a chain or cyclic structure of 1 to 25 carbon atoms containing 0 to 5 polar groups and 3 to 15 fluorine atoms An aliphatic hydrocarbon group, preferably a linear or cyclic structure alkyl group having 1 to 20 carbon atoms containing 1 to 3 polar groups and 4 to 12 fluorine atoms, such as a hydroxyl group (hydroxy group), a cyano group, a carboxyl group or an ether group. And e, f, g and h are mole% of each repeating unit with respect to the total monomer (repeating unit) constituting the polymer, e, f and g are as defined in the formula (6), h is 5 to 75 mol %, Preferably 5 to 50 mol%, more preferably 10 to 25 mol%. The weight average molecular weight (Mw) of the polymer represented by Chemical Formula 7 is 2,000 to 20,000, preferably 2,500 to 15,000, and polydispersity index (PDI) is 1.0 to 2.0, preferably 1.2 to 1.8. When the weight average molecular weight and the dispersion degree are outside the above ranges, there is a possibility that the solubility with the solvent may be lowered or a defect may occur in the resist film.

)은 연결부(connecting bond)를 나타낸다).Specific examples of the R ₁₃ is as follows (where, the bending line (

Denotes a connecting bond).

The content of the polymer represented by the formula (7) is 1 to 10 parts by weight, preferably 2 to 5 parts by weight with respect to 100 parts by weight of the photosensitive polymer, the content is less than 1 part by weight based on 100 parts by weight of the photosensitive polymer The hydrophobicity of the surface of the resist film is lowered, so that the substance in the resist film may be eluted in the immersion solvent or the water harvesting property may be impaired. If it exceeds 10 parts by weight, the resist film may be defective.

The photoresist composition according to the present invention is useful for a fine pattern forming method using a double patterning technology (DPT) or the like, which requires a pattern protective film. 1 is a view for explaining a photoresist pattern forming method using a photoresist composition of the present invention. As shown in FIG. 1, the photoresist pattern forming method according to the present invention uses the photoresist composition according to the present invention on a substrate 10 such as a semiconductor, on which an etched layer and an antireflective film or the like are formed, if necessary. To form a first photoresist pattern 20 according to a (primary) lithography process (A in FIG. 1), wherein the first photoresist pattern 20 is, for example, 130 to 200 ° C., preferably Forming the pattern protective film 22 by heating to 140 to 180 ° C. (B of FIG. 1), on the substrate 10 on which the first photoresist pattern 20 and the pattern protection film 22 are formed, a conventional photoresist Forming a second photoresist film 30 using the composition (FIG. 1C), and applying a (secondary) lithography process (exposure and development in a predetermined pattern) to the second photoresist film 30. Thus, the second photoresist pattern between the first photoresist pattern 20 Forming a turn 32 (D in FIG. 1). In this manner, after the second photoresist pattern 30 is formed, if necessary, the pattern protection film 22 on the first photoresist pattern 20 may be removed by dry etching or the like. The primary and secondary lithography processes used in this process are carried out in the same manner as conventional lithography processes. Since the photoresist pattern forming method of the present invention does not require a coating process such as a water-soluble film for forming the pattern protective film 22 after the formation of the first photoresist pattern 20, the process is simplified compared to the conventional double patterning technique. Can and economically advantageous.

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

[Examples 1 to 25 and Comparative Examples 1 to 8] Photoresist film formation and crosslinkability evaluation

The photoresist composition according to Tables 1 to 3 was applied to an 8-inch silicon wafer substrate, baked at 110 ° C. for 60 seconds, and then baked at 200 ° C. for 60 seconds to form a photoresist film (Examples 1 to 26 and Comparative Examples 1 to 1). 8) was formed. Each film thickness was measured with an optical film thickness meter (device name: nanoospec, manufacturer: nanometrics), and then a mixed solvent of propylene glycol monomethyl ether acetate (PGMEA) and cyclohexanone in a 70:30 mass ratio on the film. Was distributed for 20 seconds, spin dried at 2,000 rpm for 30 seconds, dried at 100 ° C. for 60 seconds, and the respective film thicknesses were measured again to obtain a difference (decrease in thickness) from the film thickness before solvent distribution. The degree of cure was evaluated from the reduction (bad: thickness reduction greater than 10 nm, good: 10 nm or less). The results are shown in Tables 1 to 3 below.

[Examples 26 to 50 and Comparative Examples 9 to 16] Formation and Evaluation of Photoresist Pattern and Pattern Protective Film

The photoresist compositions according to Tables 1 to 3 below were applied on a wafer at a thickness of 1,500 and soft baked at 110 ° C. for 60 seconds. After the soft bake, an exposure mask having a line and space (L / S) pattern was used and exposed using a 193 nm ArF exposure equipment (ASML 1200B) and postbaked at 110 ° C. for 60 seconds. After post-baking, the resultant was developed with a 2.38 wt% tetramethylammonium hydroxide (TMAH) aqueous solution to obtain a photoresist pattern (Examples 26 to 50 and Comparative Examples 9 to 16) with 50 nm L / S and 1: 3 pitch. Next, the photoresist pattern was heated (crosslinked and cured) at a temperature of 160 ° C to form a pattern protective film on the photoresist pattern surface. At this time, the pattern protective film was not formed on the photoresist pattern formed by the comparative examples. The sensitivity of the pattern and the line edge roughness before development and the line edge roughness after development of the pattern were measured by CD-SEM (Critical Dimension Scanning Electron Microscopy, equipment name: S-9220, manufacturer: Hitachi) The results are shown in Tables 1 to 3 below.

Table 1

TABLE 2

TABLE 3

(분자량(Mw)=6,500), A-1-2:

(분자량(Mw)=8,400), A-1-3:

(분자량(Mw)=7,900),

(A-2-1(a:b:c:n=40:35:20:5, 분자량(Mw)=6,750), A-2-2(a:b:c:n=35:35:20:10, 분자량(Mw)=6,180), A-2-3(a:b:c:n=35:30:20:15, 분자량(Mw)=6,540)),

(A-2-4(a:b:c:n=40:35:20:5, 분자량(Mw)=7,800), A-2-5(a:b:c:n=35:35:20:10, 분자량(Mw)=7,050), A-2-6(a:b:c:n=35:30:20:15, 분자량(Mw)=6,800)), A-3-1:

(분자량(Mw)=6,950) Q-1: 트리에탄올아민, Q-2: 트리옥틸아민, Q-3: 2-피퍼리딘에탄올(2-Piperidine ethanol:

), Q-4:

(분자량(Mw)=6,820), C-1:

, C-2:

, C-3:

.A-1-1:

(Molecular weight (Mw) = 6,500), A-1-2:

(Molecular weight (Mw) = 8,400), A-1-3:

(Molecular weight (Mw) = 7,900),

(A-2-1 (a: b: c: n = 40: 35: 20: 5, molecular weight (Mw) = 6,750), A-2-2 (a: b: c: n = 35: 35: 20 : 10, molecular weight (Mw) = 6,180), A-2-3 (a: b: c: n = 35: 30: 20: 15, molecular weight (Mw) = 6,540)),

(A-2-4 (a: b: c: n = 40: 35: 20: 5, molecular weight (Mw) = 7,800), A-2-5 (a: b: c: n = 35: 35: 20 : 10, molecular weight (Mw) = 7,050), A-2-6 (a: b: c: n = 35: 30: 20: 15, molecular weight (Mw) = 6,800)), A-3-1:

(Molecular weight (Mw) = 6,950) Q-1: Triethanolamine, Q-2: Trioctylamine, Q-3: 2-Piperidine ethanol:

), Q-4:

(Molecular weight (Mw) = 6,820), C-1:

, C-2:

, C-3:

.

From the above Table 1, the photoresist film using the photoresist composition according to the present invention is a film that does not dissolve in a solvent for forming a photoresist film by crosslinking and curing by a baking process at 200 ° C. (thickness reduction less than 3 nm) It turns out that In addition, in the photoresist patterns (Examples 26 to 50) using the photoresist composition according to the present invention, the pattern is not lost by the solvent for forming the photoresist film as in Comparative Examples 9 to 16, and the line edge roughness is also reduced. Reduced. This is because the effect of suppressing the flow due to heat was shown by accompanying the crosslinking curing reaction at the time of heating. Therefore, it can be seen that the photoresist film and the pattern using the photoresist composition according to the present invention can easily form a pattern protective film by a simple heating process, and do not dissolve in a solvent or the like for forming the photoresist film.

The photoresist composition according to the present invention, which can easily form a pattern protective film by a simple heating process after pattern formation, is useful for double patterning technology (DPT).

Claims (11)

3 to 30% by weight of the photosensitive polymer; 0.5 to 75 parts by weight of a crosslinking curing agent selected from the group consisting of a compound represented by the following Chemical Formula 1, a compound represented by the following Chemical Formula 2, and a mixture thereof, based on 100 parts by weight of the photosensitive polymer; 0.05 to 15 parts by weight of a photoacid generator based on 100 parts by weight of the photosensitive polymer; And Containing the remaining solvent, The photoresist composition which can form a pattern protective film on the photoresist pattern surface by heating or exposure and heating after photoresist pattern formation. [Formula 1]

[Formula 2]

In Formulas 1 and 2, R ₁ , R ₃ and R ₄ are each independently a saturated or unsaturated hydrocarbon group having 1 to 25 carbon atoms or a linear or cyclic structure containing 0 to 20 hetero elements, and R ₂ And R ₅ are each independently a saturated or unsaturated hydrocarbon group having 1 to 20 carbon atoms or a linear or cyclic structure containing 0 to 10 hetero elements. The compound of claim 1, wherein

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

, And

Will be selected from the group consisting of, photoresist composition. The compound of claim 1, wherein

,

,

, And

Will be selected from the group consisting of, photoresist composition. The photoresist composition of claim 1, wherein the photosensitive polymer is represented by Formula 3 below. [Formula 3]

In Chemical Formula 3, R ₆ is each independently hydrogen or a methyl group, and X, Y and Z are each independently a saturated or saturated chain or cyclic structure having 1 to 25 carbon atoms containing 0 to 20 hetero elements. Unsaturated hydrocarbon group, a, b and c are the mole% of each repeating unit with respect to the total monomers constituting the polymer, wherein a is 10 to 90 mole%, b is 0 to 60 mole%, and c is 0 to 60 Mol% and at least one of b and c is greater than 0 mol%. The method according to claim 4, wherein X is a saturated or unsaturated hydrocarbon group of 1 to 20 carbon atoms in a linear or cyclic structure containing 0 to 10 hetero elements, Y is 0 to 10 containing a lactone group and hetero elements A saturated or unsaturated hydrocarbon group having 3 to 20 carbon atoms or a linear or cyclic structure (wherein the carbon number is the total carbon number including the lactone moiety), and Z is 0 to 10 hetero elements, substituted with a hydroxy group or a hydroxyl group and a halogen group. It is a saturated or unsaturated hydrocarbon group having a chain or cyclic structure of 1 to 20 carbon atoms containing, photoresist composition. The photoresist composition of claim 1, further comprising 0.1 to 5 parts by weight of a basic acid diffusion regulator with respect to 100 parts by weight of the photosensitive polymer. The photoresist composition of claim 1, further comprising 1 to 10 parts by weight of a polymer represented by Formula 7 based on 100 parts by weight of the photosensitive polymer. [Formula 7]

In Formula 7, R ₆ is each independently hydrogen or a methyl group, and X, Y and Z are each independently a saturated or saturated chain or cyclic structure having 1 to 25 carbon atoms containing 0 to 20 hetero elements. Is an unsaturated hydrocarbon group, R ₁₃ is an aliphatic hydrocarbon group having 1 to 25 carbon atoms or a linear or cyclic structure having 0 to 5 polar groups and 3 to 15 fluorine atoms, and e, f, g and h are the polymers As mole% of each repeating unit relative to the total monomers, e, f and g are each independently 0 to 95 mole%, h is 5 to 75 mole%, and at least one of e, f and g is 0 Greater than mole%. 3 to 30% by weight of a photosensitive polymer selected from the group consisting of a polymer represented by the following formula (4), a polymer represented by the following formula (5), and mixtures thereof; 0.05 to 15 parts by weight of a photoacid generator based on 100 parts by weight of the photosensitive polymer; And Containing the remaining solvent, The photoresist composition which can form a pattern protective film on the photoresist pattern surface by heating or exposure and heating after photoresist pattern formation. [Formula 4]

[Formula 5]

In Formulas 4 and 5, R ₁ , R ₂ , R ₃ and R ₄ are as defined in Formulas 1 and 2, R ₆ , X, Y, Z, a, b and c are as defined in Formula 3 , m and n are mole% of each repeating unit with respect to the total monomer constituting the polymer, m is 1 to 40 mol%, n is 1 to 40 mol%. The photoresist composition of claim 8, further comprising 0.1 to 5 parts by weight of a basic acid diffusion regulator with respect to 100 parts by weight of the photosensitive polymer. Forming a first photoresist pattern on a substrate using the photoresist composition of claim 1; Heating the first photoresist pattern to form a pattern protection film; Forming a second photoresist film on the substrate on which the first photoresist pattern and the pattern protection film are formed using a photoresist composition; And And applying a lithography process to the second photoresist film to form a second photoresist pattern between the first photoresist patterns. The method of claim 10, wherein the heating temperature of the first photoresist pattern is 130 to 200 ° C. 12.

Images