KR100557610B1 - Novel photoresist monomer, polymer thereof and photoresist composition containing it - Google Patents

Abstract

The present invention relates to a vinylcyclohexanol compound represented by the following formula (1) and a photoresist polymer using the monomer as a monomer, wherein the photoresist polymer of the present invention has high transparency in the far-ultraviolet region, etching resistance and heat resistance In addition to its excellent hydroxy groups, it has excellent adhesion to substrates, which can be applied to high-density micropatterns of 0.15 µm (1G DRAM or more) or less, such as ArF, KrF, EUV, electron-beam and X. It can be used very effectively in a lithography process using a light source in an far ultraviolet region such as a ray.

[Formula 1]

In the formula, R represents hydrogen or methyl group.

Description

Novel photoresist monomers, polymers and photoresist composition containing it

1 is a pattern photograph formed using the photoresist composition of the present invention.

FIELD OF THE INVENTION The present invention relates to novel photoresist monomers, polymers thereof and photoresist compositions containing the polymers, and more particularly suitable for use in lithographic processes using light sources in the far ultraviolet region in the manufacture of microcircuits of highly integrated semiconductor devices. The vinylcyclohexanol compound which is a monomer for photoresists, its polymer, the photoresist composition containing this polymer, and its manufacturing method are related.

In order to achieve high sensitivity in the microfabrication process of semiconductor fabrication, photolithography is suitable for lithography using a light source in a chemically amplified deep ultra violet (DUV) region such as KrF (248 nm), ArF (193 nm) or EUV. The resist is in the spotlight, and such a photoresist is prepared by mixing a photoacid generator and a photoresist polymer having a structure that reacts sensitively to an acid.

The mechanism of action of the photoresist is that the photoacid generator that receives ultraviolet light from the light source generates an acid, and the polymer main chain or side chain of the exposed portion is decomposed by the acid, and then dissolved in the developer, while the non-exposed site is dissolved. Since the film retains its original structure after the developer treatment, the mask image remains as a positive image on the substrate. In such a lithography process, the resolution is dependent on the wavelength of the light source, and as the wavelength of the light source becomes smaller, a fine pattern can be formed. Accordingly, a photoresist suitable for such a light source is required.

In addition, photoresists for ArF generally have low light absorption, excellent dry etching resistance, heat resistance and adhesion at 193 nm wavelength, and are well known developer, for example, an aqueous solution of 2.38 wt% tetramethylammonium hydroxide (TMAH) It is advantageous in terms of process cost reduction that can be developed. However, it is very difficult to produce a polymer that satisfies all these properties.

To date, many studies have been conducted on resins having high transparency at a wavelength of 193 nm and dry etching resistance similar to those of novolak resins used in i-line, among which resins using methacrylate copolymers of the following structural formulas are used. Was developed by IBM.

Wherein R ₁ , R ₂ and R ₃ are H or CH ₃ .

The resin introduced aliphatic cyclic compounds in the side chain in order to increase dry etching resistance, but as the mole fraction (x) of these aliphatic cyclic compounds increased, the hydrophilicity of the resin itself was reduced and the adhesion was weakened, thereby forming a pattern when forming a fine pattern. This has the problem of falling down or falling off. Therefore, to solve this problem, copolymerization of hydrophilic monomers such as methacrylic acid is used. However, as the fraction of methacrylic acid increases, the adhesiveness increases, but the acidity of the resin itself increases, causing problems such as photoresist top loss. It is not possible to use the developer currently used, and has a disadvantage in that a special developer such as a diluted developer or a developer added with isopropyl alcohol is used. On the other hand, if the aliphatic cyclic compound is not included in a predetermined level or more, the desired level of etching property, that is, the etching selectivity cannot be obtained.

Accordingly, the inventors of the present invention have continued to research a photoresist polymer that can be used for ArF lithography, and the vinylcyclohexanol compound contains a hydroxyl group which is a compound having an aliphatic cyclic structure and a hydrophilic group, When included in the main chain, the present invention was completed by finding that not only the transparency is excellent in the far ultraviolet region, especially the 193 nm wavelength, but also the etching resistance is excellent.

It is an object of the present invention to provide novel photoresist monomers having excellent properties, polymers of such monomers and photoresist compositions containing the polymers.

In order to achieve the above object, the present invention provides a novel photoresist monomer having high transparency in the far ultraviolet region, excellent in etching resistance and adhesion, and a method for producing the same; Polymers of the monomers and methods for their preparation; A photoresist composition containing the polymer; And it provides a semiconductor device manufactured using the photoresist composition.

Hereinafter, the present invention will be described in detail.

First, the present invention provides a vinylcyclohexanol compound represented by Chemical Formula 1, which can be used as a photoresist monomer.

[Formula 1]

In the formula, R represents hydrogen or methyl group.

The monomer is preferably dihydrocarveol of formula 1a or isopulegol of formula 1b.

[Formula 1a]

[Formula 1b]

The present invention also provides a photoresist polymer comprising the addition polymerization repeating unit of the formula (1).

The photoresist polymer may further include an addition polymerization repeating unit of Formula 2 below.

[Formula 2]

R ₁ COOR ′

Where

R ₁ is a vinyl group substituted with C ₁ -C ₅ straight or branched alkyl; Or C ₁ -C ₁₀ cycloalkenyl,

R ′ represents an acid sensitive protecting group.

At this time, the acid-sensitive protecting group is preferably t-butyl, 2-ethoxyethyl, 2-ethoxypropyl, t-butoxyethyl, tetrahydropyranyl or tetrahydrofuranyl.

The photoresist polymer may also further include an addition polymerization repeating unit of Formula 3 below.

[Formula 3]

R ₂ COOH

Wherein R ₂ is a vinyl group substituted with C ₁ -C ₅ straight or branched alkyl; Or cycloalkenyl of C ₁ -C ₁₀ .

The photoresist polymer may further include a maleic anhydride of Formula 4 as an addition polymerization repeating unit.

[Formula 4]

The molecular weight of the photoresist polymer of the present invention is from 3,000 to 100,000, preferred examples of the polymer are as follows:

Poly (dihydrocarveol / maleic anhydride / tertarybutyl methacrylate / methacrylic acid) of formula (5);

[Formula 5]

Poly (dihydrocarveol / maleic hydride / tertiarybutyl acrylate / acrylic acid) of formula (6);

[Formula 6]

Poly (dihydrocarbenol / maleic anhydride / 5-norbornene-2-carboxylic acid tertiarybutyl ester / 5-norbornene-2-carboxylic acid) of formula (7);

[Formula 7]

Poly (dihydrocarbenol / maleic anhydride / 5-norbornene-2-carboxylic acid 2-ethoxyethyl ester / 5-norbornene-2-carboxylic acid) of formula (8);

[Formula 8]

Poly (dihydrocarbenol / maleic anhydride / 5-norbornene-2-carboxylic acid 2-ethoxypropyl ester / 5-norbornene-2-carboxylic acid of formula (9);

[Formula 9]

Poly (isofulegol / maleic anhydride / tertarybutyl methacrylate / methacrylic acid) of formula 10;

[Formula 10]

Poly (isofulegol / maleic anhydride / tertiarybutyl acrylate / acrylic acid) of formula 11;

[Formula 11]

Poly (isofulegol / maleic anhydride / 5-norbornene-2-carboxylic acid tertiarybutyl ester / 5-norbornene-2-carboxylic acid of formula 12);

[Formula 12]

Poly (isofulegol / maleic anhydride / 5-norbornene-2-carboxylic acid 2-ethoxyethyl ester / 5-norbornene-2-carboxylic acid of formula (13);

[Formula 13]

Poly (isopoolegol / maleic anhydride / 5-norbornene-2-carboxylic acid 2-ethoxypropyl ester / 5-norbornene-2-carboxylic acid of formula (14);

[Formula 14]

In Chemical Formulas 5 to 14, a: b: c: d is 0.01-99 mol%: 0.01-99 mol%: 0.01-99 mol%: 0.01-99 mol%.

Photoresist polymers of the present invention can be prepared by radical polymerization of monomers with conventional radical polymerization initiators, the process consisting of the following steps:

(a) (iii) a monomer of Formula 1; (Ii) dissolving at least one monomer selected from compounds consisting of Formulas 2 to 4 in an organic solvent;

(b) adding a polymerization initiator to the resultant solution of step (a); And

(c) reacting the resultant solution of step (b) under a nitrogen or argon atmosphere.

The organic solvent which is a polymerization solvent is selected from the group consisting of cyclohexanone, tetrahydrofuran, dimethylformamide, dimethyl sulfoxide, dioxane, methyl ethyl ketone, benzene, toluene and xylene; The polymerization initiator is 2,2'- azobisisobutyronitrile (AIBN), acetyl peroxide, lauryl peroxide, t- butyl per acetate, t- butyl hydroperoxide, di- t- butyl peroxide and benzoyl Preference is given to using those selected from the group consisting of peroxides.

This invention also provides the photoresist composition containing the photoresist polymer of this invention mentioned above, an organic solvent, and a photo-acid generator.

The photoacid generator is diphenyl iodo hexafluorophosphate, diphenyl iodo hexafluoro arsenate, diphenyl iodo hexafluoro antimonate, diphenyl paramethoxyphenyl triflate, diphenyl paratoluenyl triflate, diphenyl Paraisobutylphenyl triflate, diphenylpara-t-butylphenyl triflate, triphenylsulfonium hexafluoro phosphate, triphenylsulfonium hexafluoro arsenate, triphenylsulfonium hexafluoro antimonate, triphenylsulfonium Sulphide-based or onium salt-based compounds selected from the group consisting of triflate and dibutylnaphthylsulfonium triflate are mainly used, preferably in a proportion of 0.05 to 10% by weight relative to the resin. When used in an amount of less than 0.05% by weight, the sensitivity of the photoresist to light is weak, when more than 10% by weight of the photo-acid generator absorbs a lot of light to obtain a pattern having a bad cross section.

In addition, the organic solvent may be selected from the group consisting of propylene glycol methyl ether acetate, propylene glycol methyl ether, ethyl lactate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate and cyclohexanone. desirable. This organic solvent is used in a ratio of 100 to 1000% by weight relative to the photoresist polymer, which is to obtain a desired film thickness, and in the present invention, when used in an amount of 500% by weight, the film thickness is 0.5 탆.

The present invention also provides a method of forming a photoresist pattern consisting of the following steps:

(a) applying the 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 to obtain a desired pattern.

In the process, i) before and after exposure of step (b); Or ii) pre- or post-exposure each of which may further comprise a baking process, which is carried out at 70 to 200 ° C.

In addition, the exposure process may be performed using an exposure energy of 1 to 100 mJ / cm ² by using deep ultra violet (DUV), E-beam, X-ray or ion beam including ArF, KrF and EUV as a light source. It is preferable to carry out.

The present invention also provides a semiconductor device manufactured using the photoresist composition of the present invention.

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 (Dihydrocarbenol / Maleic Anhydride / Turethanebutyl Methacrylate / Methacrylic Acid)

154.25 g of dihydrocarveol, 107.87 g of maleic anhydride, 71.10 g of tert-butyl methacrylate, and 4.3 g of methacrylic acid were dissolved in 250 ml of tetrahydrofuran. 0.03 mol of AIBN was added thereto and reacted under a nitrogen atmosphere for 24 hours. This was precipitated in ethyl ether, filtered and dried in vacuo to give 270 g of product (yield: 80%).

Example 2. Preparation of Poly (Dihydrocabenool / Maleic Hydride / Turethanebutyl Acrylate / Acrylic Acid)

154.25 g of dihydrocarveol, 107.87 g of maleic anhydride, 64.08 g of tertiary butyl acrylate and 3.6 g of acrylic acid were dissolved in 250 ml of tetrahydrofuran. 4.8 g of AIBN was added thereto and reacted under a nitrogen atmosphere for 24 hours. It was precipitated in ethyl ether, filtered and dried in vacuo to give 270 g of product (yield: 82%).

Example 3. Preparation of Poly (Dihydrocarbenol / maleic anhydride / 5-norbornene-2-carboxylic acid tertiarybutyl ester / 5-norbornene-2-carboxylic acid)

38.56 g of dihydrocarveol, 49 g of maleic anhydride, 38.85 g of 5-norbornene-2-carboxylic acid tertiary butyl ester, and 6.9 g of 5-norbornene-2-carboxylic acid were dissolved in 250 ml of tetrahydrofuran. 4.8 g mol of AIBN was added thereto and reacted under a nitrogen atmosphere for 24 hours. It was precipitated in ethyl ether, filtered and dried in vacuo to yield 100 g of product (yield: 75%).

Example 4. Preparation of Poly (Dihydrocarbenol / maleic anhydride / 5-norbornene-2-carboxylic acid 2-ethoxyethyl ester / 5-norbornene-2-carboxylic acid)

38.56 g of dihydrocarveol, 49 g of maleic anhydride, 42.05 g of 5-norbornene-2-carboxylic acid 2-ethoxyethyl ester and 6.9 g of 5-norbornene-2-carboxylic acid were dissolved in 250 ml of tetrahydrofuran. 4.8 g mol of AIBN was added thereto and reacted under a nitrogen atmosphere for 24 hours. It was precipitated in ethyl ether, filtered and dried in vacuo to afford 89 g of product (yield: 65%).

Example 5. Preparation of Poly (Dihydrocarbenol / maleic anhydride / 5-norbornene-2-carboxylic acid 2-ethoxypropyl ester / 5-norbornene-2-carboxylic acid)

38.56 g of dihydrocarveol, 49 g of maleic anhydride, 44.86 g of 5-norbornene-2-carboxylic acid 2-ethoxypropyl ester, and 6.9 g of 5-norbornene-2-carboxylic acid were dissolved in 250 ml of tetrahydrofuran. 4.8 g mol of AIBN was added thereto and reacted under a nitrogen atmosphere for 24 hours. This was precipitated in ethyl ether, filtered and dried in vacuo to give 84 g of product (yield: 60%).

Example 6 Preparation of Poly (Isofulegol / Maleic Anhydride / Turethanebutyl Methacrylate / Methacrylic Acid)

The title polymer was synthesized in the same manner as in Example 1 except for using isofullegol instead of dihydrocarveol (202.5 g, 60% yield).

Example 7 Preparation of Poly (Isofulegol / Maleic Hydride / Turmericbutyl Acrylate / Acrylic Acid)

The title polymer was synthesized in the same manner as in Example 2, except for using isofullegol instead of dihydrocarveol (191.3 g, yield 58%).

Example 8. Preparation of Poly (Isofulegol / Maleic Hydride / 5-norbornene-2-carboxylic acid tertiarybutyl ester / 5-norbornene-2-carboxylic acid)

The title polymer was synthesized in the same manner as in Example 3, except for using isofulegol instead of dihydrocarveol (82.7 g, 62% yield).

Example 9 Preparation of Poly (Isofulegol / Maleic Anhydride / 5-norbornene-2-carboxylic Acid 2-ethoxyethyl Ester / 5-norbornene-2-carboxylic Acid)

The title polymer was synthesized in the same manner as in Example 4, except for using isofulegol instead of dihydrocarveol (73.7 g, yield 54%).

Example 10 Preparation of Poly (Isofulegol / Maleic Anhydride / 5-norbornene-2-carboxylic Acid 2-ethoxypropyl Ester / 5-norbornene-2-carboxylic Acid)

The title polymer was synthesized in the same manner as in Example 5 except for using isofullegol instead of dihydrocarveol (69.7 g, yield 50%).

II. Preparation and Pattern Formation of Photoresist Composition

Example 11.

10 g of the polymer of Example 1 and 0.2 g of triphenylsulfonium triflate as a photoacid generator were dissolved in 50 g of propylene glycol methyl ether acetate solvent, and filtered through a 0.1 µm filter to obtain a photoresist composition.

The composition was spin applied onto a silicon wafer and then heated at 100 ° C. for 90 seconds. After heating, the resultant was exposed to ArF laser exposure equipment and heated again at 130 ° C. for 90 seconds. After the completion of heating, the solution was developed with a 2.38wt% TMAH aqueous solution, and a 0.20 μm L / S pattern was obtained using an ArF exposure machine (see FIG. 1).

Example 12.

A 0.20 μm L / S pattern was obtained in the same manner as in Example 11 except that the polymer of Example 2 was used instead of the polymer of Example 1.

Example 13.

A 0.20 μm L / S pattern was obtained in the same manner as in Example 11 except that the polymer of Example 3 was used instead of the polymer of Example 1.

Example 14.

A 0.20 μm L / S pattern was obtained in the same manner as in Example 11 except that the polymer of Example 4 was used instead of the polymer of Example 1.

Example 15.

A 0.20 μm L / S pattern was obtained in the same manner as in Example 11 except that the polymer of Example 5 was used instead of the polymer of Example 1.

Example 16.

A 0.20 μm L / S pattern was obtained in the same manner as in Example 11 except that the polymer of Example 6 was used instead of the polymer of Example 1.

Example 17.

A 0.20 μm L / S pattern was obtained in the same manner as in Example 11 except that the polymer of Example 7 was used instead of the polymer of Example 1.

Example 18.

A 0.20 μm L / S pattern was obtained in the same manner as in Example 11 except that the polymer of Example 8 was used instead of the polymer of Example 1.

Example 19.

A 0.20 μm L / S pattern was obtained in the same manner as in Example 11 except that the polymer of Example 9 was used instead of the polymer of Example 1.

Example 20.

A 0.20 μm L / S pattern was obtained in the same manner as in Example 11 except that the polymer of Example 10 was used instead of the polymer of Example 1.

Synthesis of the resin in the same manner as the present invention makes it easy to form the polymer by general radical polymerization, and the photoresist polymer thus prepared exhibits high transparency and dry etching resistance at 193 nm. In addition, since the hydroxy group is included in the main chain of the photoresist polymer, the adhesion to the substrate is excellent, and actual lithography experiments show excellent resolution of 0.20 μm (see FIG. 1). Therefore, by using the photoresist polymer of the present invention, it is possible to obtain a photoresist composition that can be applied to high-density micropatterns, thereby producing a highly reliable semiconductor device.

Claims (24)

delete delete A photoresist polymer comprising an addition polymerization repeating unit of Formula 1 and an addition polymerization repeating unit of Formula 2 below: [Formula 1]

[Formula 2] R ₁ COOR ′ Where R is hydrogen or a methyl group; R ₁ is a vinyl group substituted with C ₁ -C ₅ straight or branched alkyl; Or C ₁ -C ₁₀ cycloalkenyl; R ′ represents an acid sensitive protecting group. The method of claim 3, wherein The compound of Formula 1 is a dihydrocarveol (dihydrocarveol) of the formula (1a) or isopulegol (isopulegol) of the formula (1b) characterized in that. [Formula 1a]

[Formula 1b]

The method of claim 3, wherein The acid-sensitive protecting group is selected from the group consisting of t-butyl, 2-ethoxyethyl, 2-ethoxypropyl, t-butoxyethyl, tetrahydropyranyl and tetrahydrofuranyl. The method of claim 3, wherein A photoresist polymer further comprising: an addition polymerization repeating unit of Formula 3: [Formula 3] R ₂ COOH Wherein R ₂ is a vinyl group substituted with C ₁ -C ₅ straight or branched alkyl; Or cycloalkenyl of C ₁ -C ₁₀ . The method of claim 6, A photoresist polymer further comprising a maleic anhydride of Formula 4 as an addition polymerization repeating unit. [Formula 4]

The method of claim 3, wherein The molecular weight of the polymer is a photoresist polymer, characterized in that 3,000 to 100,000. The method of claim 7, wherein the polymer Poly (dihydrocarveol / maleic anhydride / tertarybutyl methacrylate / methacrylic acid) of formula (5); Poly (dihydrocarveol / maleic hydride / tertiarybutyl acrylate / acrylic acid) of formula (6); Poly (dihydrocarbenol / maleic anhydride / 5-norbornene-2-carboxylic acid tertiarybutyl ester / 5-norbornene-2-carboxylic acid) of formula (7); Poly (dihydrocarbenol / maleic anhydride / 5-norbornene-2-carboxylic acid 2-ethoxyethyl ester / 5-norbornene-2-carboxylic acid) of formula (8); Poly (dihydrocarbenol / maleic anhydride / 5-norbornene-2-carboxylic acid 2-ethoxypropyl ester / 5-norbornene-2-carboxylic acid of formula (9); Poly (isofulegol / maleic anhydride / tertarybutyl methacrylate / methacrylic acid) of formula 10; Poly (isofulegol / maleic anhydride / tertiarybutyl acrylate / acrylic acid) of formula 11; Poly (isofulegol / maleic anhydride / 5-norbornene-2-carboxylic acid tertiarybutyl ester / 5-norbornene-2-carboxylic acid of formula 12); Poly (isopulegol / maleic anhydride / 5-norbornene-2-carboxylic acid 2-ethoxyethyl ester / 5-norbornene-2-carboxylic acid) A photo selected from the group consisting of poly (isofulegol / maleic anhydride / 5-norbornene-2-carboxylic acid 2-ethoxypropyl ester / 5-norbornene-2-carboxylic acid) Resist Polymer: [Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

[Formula 9]

[Formula 10]

[Formula 11]

[Formula 12]

[Formula 13]

[Formula 14]

In Chemical Formulas 5 to 14, a: b: c: d is 0.01-99 mol%: 0.01-99 mol%: 0.01-99 mol%: 0.01-99 mol%. delete delete delete A photoresist composition comprising a photoresist polymer, an organic solvent, and a photoacid generator, wherein the photoresist polymer comprises (i) a monomer of formula (1); (Ii) a photoresist composition characterized by addition polymerization of at least one monomer selected from compounds of formulas (2) to (4) [Formula 1]

In the formula, R represents hydrogen or methyl group. [Formula 2] R ₁ COOR ′ Where R ₁ is a vinyl group substituted with C ₁ -C ₅ straight or branched alkyl; Or C ₁ -C ₁₀ cycloalkenyl, R ′ represents an acid sensitive protecting group. [Formula 3] R ₂ COOH Wherein R ₂ is a vinyl group substituted with C ₁ -C ₅ straight or branched alkyl; Or cycloalkenyl of C ₁ -C ₁₀ . [Formula 4]

delete The method of claim 13, The photoacid generator is diphenyl iodo hexafluorophosphate, diphenyl iodo hexafluoro arsenate, diphenyl iodo hexafluoro antimonate, diphenyl paramethoxyphenyl triflate, diphenyl paratoluenyl triflate, diphenyl Paraisobutylphenyl triflate, diphenylpara-t-butylphenyl triflate, triphenylsulfonium hexafluoro phosphate, triphenylsulfonium hexafluoro arsenate, triphenylsulfonium hexafluoro antimonate, triphenylsulfonium Triflate, dibutylnaphthylsulfonium triflate, propylene glycol methyl ether acetate, propylene glycol methyl ether, ethyl lactate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate and cyclohexanone Characterized in that it comprises one or more selected from Photoresist composition. The method of claim 13, The photoacid generator is used at a ratio of 0.05 to 10% by weight based on the polymer; The organic solvent is a photoresist composition, characterized in that used in 100 to 1000% by weight relative to the polymer. delete delete (a) applying the photoresist composition of claim 13 over the etched layer to form a photoresist film; (b) baking the photoresist film at 70 to 200 ° C; (c) exposing the baked photoresist film; (d) baking the exposed photoresist film at 70 to 200 ° C; And (e) developing the resultant to obtain a desired pattern. delete delete The method of claim 19, The exposure process is a photoresist pattern forming method using a deep ultraviolet (DUV; E-beam, X-ray or ion beam including ArF, KrF and EUV as a light source. delete A semiconductor device manufactured by the method of claim 19.

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