KR100682197B1 - Maleimide-photoresist monomer containing halogen and photoresist polymer comprising the same - Google Patents

Abstract

The present invention relates to a novel photoresist monomer, a photoresist polymer polymerized therefrom, and a photoresist composition using the polymer, comprising a maleimide monomer represented by Formula 1 below and a polymer polymerized therefrom and the polymer The photoresist composition of the present invention is excellent in etching resistance, heat resistance and adhesion, and is not only developable in aqueous tetramethylammonium hydroxide (TMAH) solution, but also has low light absorption at wavelengths of 193 nm and 157 nm. When fabricating a microcircuit, it can be very useful for a lithography process using a light source in the far ultraviolet region, especially a VUV (157 nm) light source.

[Formula 1]

Wherein X ₁ , X ₂ , R ₁ , R ₂ and R ₃ are as defined in the specification.

Description

Maleimide-based photoresist monomer containing a halogen element and a photoresist polymer comprising the same {Maleimide-photoresist monomer containing halogen and photoresist polymer comprising the same}

1 to 4 are pattern photographs obtained in the embodiment of the present invention.

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to novel photoresist monomers, polymers thereof, and photoresist compositions using the polymers. It relates to a photoresist polymer suitable for use in the process, a photoresist composition using the polymer and a method for producing the same.

In order to be used as a photoresist for ArF and VUV (vacuum ultraviolet), it has to have low light absorption at wavelengths of 193nm and 157nm, have excellent etching resistance and adhesion to substrates, and 2.38 wt% and 2.6 wt% tetramethylammonium hydroxide. Many requirements must be met, such as development with an aqueous solution of TMAH.

The main research direction so far has been to search for resins having a high transparency at 193 nm and etching resistance at the same level as the novolak resin. However, most of these resists exhibit strong absorbance in the wavelength region of 157 nm, which is not suitable for VUV resists. In order to compensate for this, researches on developing resists containing fluorine and silicon have been intensively conducted, but have not yet developed satisfactory resists for VUV. Currently, polyethylene-based, polystyrene-based, and polyacrylate-based resins containing fluorine have low solubility in an aqueous TMAH solution, which is difficult to develop, and has a disadvantage in that adhesion to a silicon substrate is greatly reduced. In addition, the resin is difficult to mass-produce, the price is high, it is not suitable for commercial use. On the other hand, the photosensitive agent including the maleic hydride-norbornene-based polymer has high adhesion to the silicon substrate and has relatively good etching characteristics compared to the acrylate compound.

Accordingly, the present inventors have completed the present invention by finding that a polymer using a maleimide compound in which fluorine is substituted in place of the maleic hydride compound has not only low absorption at 157 nm wavelength but also excellent etching characteristics.

It is an object of the present invention to provide novel photoresist polymers and photoresist compositions containing these polymers that can be used in ArF (193 nm) as well as VUV (157 nm) light sources.

In order to achieve the above object, the present invention provides a maleimide-based photoresist monomer containing a halogen element, in particular fluorine, a photoresist polymer polymerized with the monomer, and a photoresist composition containing the same.

Hereinafter, the present invention will be described in detail.

In the present invention, first, a maleimide photoresist monomer, which is represented by Chemical Formula 1, is provided.

[Formula 1]

Where

X ₁ and X ₂ are H, CF ₃ or a halogen element,

R ₁ is F or CF ₃ ,

R ₂ and R ₃ is an alkoxy group of H, F, CF _3, OH, C ₁ -C ₁₀ alkyl group, an alkyl group or a C ₁ -C ₁₀ perfluoroalkyl C ₁ -C _10.

Preferred examples of the monomer of Formula 1 include N-perfluoropropylmaleimide or N-perfluorooctylmaleimide.

The present invention provides a photoresist polymer comprising the monomer of Formula 1 as a first monomer.

The photoresist polymer of the present invention may further include a compound of Formula 2 as a second monomer.

[Formula 2]

Where

Y ₁ and Y ₂ are O, CH ₂ , CH ₂ CH ₂ ,

R _4, R ₅ and R ₆ is H, F, CF _3, OH, an alkoxy group of C ₁ -C ₁₀ alkyl group, C ₁ -C ₁₀ alkyl group or C ₁ -C ₁₀ perfluoroalkyl,

f and g are integers of 0 or 1.

In addition, the polymer of the present invention may further include a compound of formula 3 as a third monomer.

[Formula 3]

Where

Z ₁ and Z ₂ are O, CH ₂ , CH ₂ CH ₂ ,

h is an integer of 0 or 1.

The photoresist polymer of the present invention may be represented by the following formula (4).

[Formula 4]

Where

X ₁ and X ₂ are H, CF ₃ or a halogen element,

Y ₁ , Y ₂ , Z ₁ and Z ₂ are O, CH ₂ , CH ₂ CH ₂ ,

R ₁ is F or CF ₃ ,

_{R 2, R 3, R 4} , R 5 and R ₆ is _{H, F, CF 3, OH} , C 1 -C ₁₀ alkyl group, C ₁ -C ₁₀ alkyl group, a perfluoroalkyl or a C ₁ -C ₁₀ Is an alkoxy group of

f, g and h are integers of 0 or 1,

The molar ratio of a: b: c is 1-50: 40-60: 0-30.

Preferred examples of the photoresist polymer are

Poly (N-perfluoropropylmaleimide / t-butyl 5-norbornene-2-carboxylate);

Poly (N-perfluoropropylmaleimide / t-butyl 5-norbornene-2-carboxylate / norbornylene);

Poly (N-perfluorooctylmaleimide / t-butyl 5-norbornene-2-carboxylate); or

Poly (N-perfluorooctylmaleimide / t-butyl 5-norbornene-2-carboxylate / norbornylene) and the like.

In addition, the present invention comprises the steps of (a) (i) mixing the compound of Formula 1, (ii) the compound of Formula 2 and optionally (iii) the compound of Formula 3; And (b) adding a polymerization initiator to the resultant of step (a) to polymerize the photoresist polymer.

The polymerization is preferably carried out in a solvent selected from tetrahydrofuran, dimethylformamide, dimethyl sulfoxide, dioxane, benzene, toluene and xylene, and the polymerization initiator is 2,2'-azobisisobutyronitrile ( AIBN), benzoyl peroxide, acetyl peroxide, lauryl peroxide and t-butyl peroxide are preferably selected from the group consisting of.

Furthermore, it is more preferable to crystallize the produced polymer using diethyl ether, petroleum ether, alkanes, alcohols, water or a mixed solvent thereof.

The present invention also provides a photoresist composition comprising the photoresist polymer described above, an organic solvent, and a photoacid generator.

The photoacid generator is selected from the group consisting of phthalimidotrifluoromethanesulfonate, dinitrobenzyltosylate, n-decyldisulfone, and naphthylimidotrifluoromethanesulfonate having relatively low absorbance at 157 nm and 193 nm. It is preferable to use, and together with it, diphenyl iodo hexafluorophosphate, diphenyl iodo hexafluoro arsenate, diphenyl iodo hexafluoro antimonate, diphenyl paramethoxy phenyl triflate, diphenyl paratolu Enyl triflate, diphenylparaisobutylphenyl triflate, triphenylsulfonium hexafluoro arsenate, triphenylsulfonium hexafluoro antimonate, triphenylsulfonium triflate and dibutylnaphthylsulfonium triflate A photoacid generator selected from the group consisting of can be used.

Such a photoacid generator is preferably used in an amount of 0.05 to 10 parts by weight based on the photoresist resin. When the amount of the photoacid generator is 0.05 parts by weight or less, the sensitivity of the photoresist to light is weak. When the photoacid generator is used at 10 parts by weight or more, the photoacid generator absorbs a lot of ultraviolet rays and a large amount of acid is generated, resulting in a bad cross section. You get

In addition, the organic solvent is diethylene glycol diethyl ether, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propylene glycol methyl ether acetate, cyclohexanone and 2-heptanone It is preferable to use those selected from the group consisting of.

The organic solvent is used in an amount of 200 to 1000 parts by weight based on the resin for the photoresist, in order to obtain a photoresist having a desired thickness. In the present invention, the thickness of the photoresist was 0.25 μm when used in 1000 parts by weight.

In another aspect, the present invention provides a method of forming a photoresist pattern comprising the following steps:

(a) applying the above-described photoresist composition of the present invention on the etched layer to form a photoresist film;

(b) exposing the photoresist film; And

(c) developing the result.

I) pre-exposure and post-exposure of step (b); Or ii) before the exposure or after the exposure, respectively, the baking process may be performed, and the baking process is preferably performed at 70 to 200 ° C.

The exposure process is preferably performed at an exposure energy of 1 to 100mJ / cm 2 using ArF, KrF, VUV, EUV, E-beam, X-ray or ion beam as a light source.

In addition, the present invention provides a semiconductor device manufactured using the photoresist composition of the present invention described above.

Hereinafter, the present invention will be described in detail by examples. However, the examples are only to illustrate the invention and the present invention is not limited by the following examples.

I. Preparation of Photoresist Polymer

Example 1 Preparation of Poly (N-perfluoropropylmaleimide / t-butyl 5-norbornene-2-carboxylate)

N-perfluoropropylmaleimide (100 mmol), t-butyl-5-norbornene-2-carboxylate (55 mmol) and AIBN (0.30 g) were dissolved in 25 ml of tetrahydrofuran solution and then 6 hours at 65 ° C. Reacted for a while. After the reaction, the reaction mixture was dropped into diethyl ether or diethyl ether / petroleum ether to obtain a solid in a pure state, which was filtered and dried to give the title polymer (yield 32%).

Example 2. Preparation of Poly (N-perfluoropropylmaleimide / t-butyl 5-norbornene-2-carboxylate / norbornylene)

N-perfluoropropylmaleimide (100 mmol), norbornylene (30 mmol), t-butyl-5-norbornene-2-carboxylate (70 mmol), AIBN (0.30 g) was added to 25 ml of tetrahydrofuran solution. After melting, the mixture was reacted at 65 ° C. for 6 hours. After the reaction, the reaction mixture was dropped in diethyl ether or diethyl ether / petroleum ether to obtain a solid in a pure state, which was filtered and dried to give the title polymer (yield 31%).

Example 3. Preparation of Poly (N-perfluorooctylmaleimide / t-butyl 5-norbornene-2-carboxylate)

 N-perfluorooctylmaleimide (100 mmol), t-butyl-5-norbornene-2-carboxylate (55 mmol) and AIBN (0.30 g) were dissolved in 25 ml of tetrahydrofuran solution and then 6 hours at 65 ° C. Reacted for a while. After the reaction, the reaction mixture was dropped into diethyl ether or diethyl ether / petroleum ether to obtain a solid in a pure state, which was filtered and dried to give the title polymer (yield 32%).

Example 4 Preparation of Poly (N-Perfluorooctylmaleimide / t-butyl 5-norbornene-2-carboxylate / norbornylene)

N-perfluorooctylmaleimide (100 mmol), norbornylene (30 mmol), t-butyl-5-norbornene-2-carboxylate (70 mmol), AIBN (0.30 g) was added to 25 ml of tetrahydrofuran solution. After melting, the mixture was reacted at 65 ° C. for 6 hours. After the reaction, the reaction mixture was dropped in diethyl ether or diethyl ether / petroleum ether to obtain a solid in a pure state, which was filtered and dried to give the title polymer (yield 31%).

II. Preparation and Pattern Formation of Photoresist Composition

Example 5.

10 g of the polymer prepared in Example 1, 0.06 g of phthalimidotrifluoromethanesulfonate, a photoacid generator, and 0.06 g of triphenylsulfonium triflate were dissolved in 100 g of propylene glycol methyl ether acetate (PGMEA) solvent, and then filtered through a 0.20 μm filter. To obtain a photoresist composition.

The composition was spin coated on a silicon wafer and then baked at 110 ° C. for 90 seconds. After baking, the wafer was exposed with an ArF laser exposure apparatus and baked again at 110 ° C. for 90 seconds. After the baking was completed, the solution was developed for 40 seconds in an aqueous 2.38wt% tetramethylammonium hydroxide (TMAH) solution to obtain a 0.12 μm L / S pattern (see FIG. 1).

Example 6.

A photoresist composition was prepared in the same manner as in Example 5, except that the polymer of Example 2 was used instead of the polymer of Example 1, thereby obtaining a 0.12 μm L / S pattern (see FIG. 2). .

Example 7.

A photoresist composition was prepared in the same manner as in Example 5, except that the polymer of Example 3 was used instead of the polymer of Example 1, thereby obtaining a 0.12 μm L / S pattern (see FIG. 3). .

Example 8.

A photoresist composition was prepared in the same manner as in Example 5, except that the polymer of Example 4 was used instead of the polymer of Example 1, thereby obtaining a 0.11 μm L / S pattern (see FIG. 4). .

As described above, by using the photoresist composition of the present invention, it is possible to form a photoresist pattern excellent in durability, etching resistance, reproducibility, and resolution, and ultrafine patterns of 4G and 16G DRAMs as well as DRAMs of 1G or less. It can be used for formation. In addition, the photoresist polymer of the present invention contains fluorine, and thus is excellent in absorbance at low wavelength, and therefore is suitable for use in light sources such as VUV, EUV, and E-beam as well as ArF and KrF.

Claims (21)

delete delete A photoresist polymer comprising the monomer of Formula 1 as a polymerization repeating unit. [Formula 1]

Where X ₁ and X ₂ are H, CF ₃ or a halogen element, R ₁ is F or CF ₃ , R ₂ and R ₃ are perfluoro alkyl groups of H, F, CF ₃ and C ₁ -C ₁₀ . The method of claim 3, wherein The polymer is a photoresist polymer, characterized in that it further comprises a compound of formula (2) as a polymerization repeating unit. [Formula 2]

Where Y ₁ and Y ₂ are O, CH ₂ , CH ₂ CH ₂ , R ₄ , R ₅ and R ₆ are alkyl groups of C ₁ -C ₃ , f and g are integers of 0 or 1. The method of claim 3, wherein The polymer is a photoresist polymer, characterized in that it further comprises a compound of formula (3) as a polymerization repeating unit. [Formula 3]

Where Z ₁ and Z ₂ are O, CH ₂ , CH ₂ CH ₂ , h is an integer of 0 or 1. The method of claim 3 wherein the photoresist polymer is Poly (N-perfluoropropylmaleimide / t-butyl 5-norbornene-2-carboxylate); Poly (N-perfluoropropylmaleimide / t-butyl 5-norbornene-2-carboxylate / norbornylene); Poly (N-perfluorooctylmaleimide / t-butyl 5-norbornene-2-carboxylate); And A photoresist polymer, characterized in that it is selected from the group consisting of poly (N-perfluorooctylmaleimide / t-butyl 5-norbornene-2-carboxylate / norbornylene). (a) mixing (i) a compound of formula 1, (ii) a compound of formula 2 and optionally (iii) a compound of formula 3; And (b) adding a polymerization initiator to the resultant of step (a) to polymerize the photoresist, characterized in that it comprises the step of polymerization. [Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

Where X ₁ and X ₂ are H, CF ₃ or a halogen element, Y ₁ , Y ₂ , Z ₁ and Z ₂ are O, CH ₂ , CH ₂ CH ₂ , R ₁ is F or CF ₃ , R ₂ and R ₃ are perfluoro alkyl groups of H, F, CF ₃ and C ₁ -C ₁₀ , R ₄ , R ₅ and R ₆ are alkyl groups of C ₁ -C ₃ , f, g and h are integers of 0 or 1, The molar ratio of a: b: c is 1-50: 40-60: 0-30. The method of claim 7, wherein Wherein said polymerization is carried out in a solvent selected from tetrahydrofuran, dimethylformamide, dimethylsulfoxide, dioxane, benzene, toluene and xylene. The method of claim 7, wherein The polymerization initiator is a photoresist polymer, characterized in that selected from the group consisting of 2,2'-azobisisobutyronitrile (AIBN), benzoyl peroxide, acetyl peroxide, lauryl peroxide and t-butyl peroxide Manufacturing method. A photoresist composition comprising the photoresist polymer of claim 3, an organic solvent and a photoacid generator. The method of claim 10, The organic solvent is selected from the group consisting of diethylene glycol diethyl ether, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propylene glycol methyl ether acetate, cyclohexanone and 2-heptanone, The photoresist is selected from the group consisting of phthalimido trifluoromethanesulfonate, dinitrobenzyltosylate, n-decyldisulfone and naphthylimidotrifluoromethanesulfonate. The method of claim 11, Diphenyl iodo hexafluorophosphate, diphenyl iodo hexafluoro arsenate, diphenyl iodo hexafluoro antimonate, diphenyl paramethoxy phenyl triflate, diphenyl paratoluenyl tri Plate, diphenylparaisobutylphenyl triflate, triphenylsulfonium hexafluoro arsenate, triphenylsulfonium hexafluoro antimonate, triphenylsulfonium triflate and dibutylnaphthylsulfonium triflate The photoresist composition further comprises at least one photoacid generator selected from. The method of claim 10, The photoacid generator is used in 0.05 to 10 parts by weight based on the photoresist polymer, The organic solvent is a photoresist composition, characterized in that used in 200 to 1000 parts by weight based on the photoresist polymer. delete delete (a) applying the photoresist composition of claim 10 over the etched layer; (B) baking the applied photoresist composition to form a photoresist film; (c) exposing the obtained photoresist film; (d) baking the result; And (e) developing the resultant to obtain a desired pattern. delete delete The method of claim 16, And the exposure process is performed using ArF, KrF, EUV, VUV, E-beam, X-ray or ion beam as a light source. delete The method of claim 3, wherein The compound of formula 1 is N-perfluoropropyl maleimide or N-perfluoro octyl maleimide, characterized in that the photoresist polymer.

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