KR20020079127A - Maleimide-photoresist monomer containing halogen and photoresist polymer comprising the same - Google Patents

Abstract

PURPOSE: Provided are a maleimide-based photoresist monomer containing a halogen element and a photoresist polymer containing the monomer, which are excellent in etching resistance, heat resistance, and adhesive property and can be used under the light source of ArF and VUV. CONSTITUTION: The photoresist monomer is N-perfluoropropyl maleimide or N-perfluorooctyl maleimide and represented by the formula 1. The photoresist polymer contains the photoresist monomer and is poly(N-perfluoropropyl maleimide/t-butyl 5-norbornene-2-carboxylate), poly(N-perfluorooctyl maleimide/t-butyl 5-norbornene-2-carboxylate/norbornylene), and etc. In the formula, X1 and X2 are H, CF3, or a halogen element, R1 is F or CF3, R2 and R3 are H, F, CF3, OH, C1-C10 alkyl, C1-C10 perfluoro alkyl, or C1-C10 alkoxy.

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}

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, Many requirements must be met, such as development with an aqueous solution of TMAH.

To date, the main research direction 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.

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

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,

a: b: c = 1-50 mol%: 40-60 mol%: 0-30 mol%.

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 a proportion of 0.05 to 10% by weight based on the photoresist resin. When the amount of the photoacid generator is 0.05% by weight or less, the sensitivity of the photoresist to light is weak. When the photoacid generator is used at 10% 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% by weight relative to the resin for the photoresist, in order to obtain a photoresist having a desired thickness. In the present invention, the thickness of the photoresist is 0.25 It was micrometer.

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)

Photoresist monomer, characterized in that represented by the formula (1). [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. The method of claim 1, The monomer is a photoresist monomer, characterized in that N-perfluoropropylmaleimide or N-perfluorooctylmaleimide. A photoresist polymer comprising the monomer of Formula 1 as a first monomer. [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. The method of claim 3, wherein A photoresist polymer further comprising 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. The method of claim 3, wherein A photoresist polymer further comprising 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 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, 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, a: b: c = 1-50 mol%: 40-60 mol%: 0-30 mol%. 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 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 photoresist composition is a photoresist composition, characterized in that used in a ratio of 0.05 to 10% by weight relative to the photoresist polymer. The method of claim 10, The organic solvent is selected from the group consisting of diethylene glycol diethyl ether, methyl 3-methoxy propionate, ethyl 3-ethoxy propionate, propylene glycol methyl ether acetate, cyclohexanone and 2-heptanone. Photoresist composition. The method of claim 10, The organic solvent is a photoresist composition, characterized in that used in an amount of 200 to 1000% by weight relative to the photoresist polymer. (a) applying the photoresist composition of claim 10 over the etched layer to form a photoresist film; (b) exposing the photoresist film; And (c) developing the resultant to obtain a desired pattern. The method of claim 16, I) pre-exposure and post-exposure of step (b); Or ii) performing a baking process before or after exposure, respectively. The method of claim 17, The baking process is a photoresist pattern forming method, characterized in that performed at 70 to 200 ℃. The method of claim 16, The exposure process is a photoresist pattern forming method characterized in that it is performed using ArF, KrF, EUV, VUV, E-beam, X-rays or ion beam as a light source. The method of claim 16, The exposure process is a photoresist pattern forming method, characterized in that carried out with an exposure energy of 1 to 100mJ / ㎠. A semiconductor device manufactured using the method of claim 16.