KR20030035006A - Polymer for chemical amplification negative photoresist and photoresist composition - Google Patents

Abstract

PURPOSE: A monomer for preparing a chemical amplification type negative photoresist polymer, a photoresist polymer and a photoresist composition containing the polymer are provided, to prevent the swelling of a polymer and to enable the pattern of high resolution to be formed. CONSTITUTION: The monomer is a norbornene-based monomer having an acetal group, represented by the formula 1, or a monomer represented by the formula 2, wherein R1, R2, R5 and R6 are independent each another and are H, CH3, OH, CH2OH, COOCH3 or COOC(CH3)3; R3 is (R)α(CH2)βR' or (R)α((CH2)mO)γR' (wherein R is -CO-, -COO-, -O-, -OCO- or -OCOO-, R' is -O-, -COO- or -OCOO, α is 0 or 1, β is 0-5, m is 1 or 2 and γ is 1-5); R4 is a saturated alkyl group of C1-C5, an unsaturated alkyl group, an aromatic group, an ether group, a carbonyl group, an amine group or an alcohol group; R7 is (R)α(CH2)β or (R) α((CH2)mO)γR+ (wherein R is -CO-, -COO-, -O-, -OCO- or -OCOO-, R+ is an alkyl group, α is 0 or 1, β is 0-5, m is 1 or 2 and γ is 1-5); and R8 and R9 are independent each other and are H or OH. The photoresist polymer contains the monomer of the formula 1. The photoresist composition comprises 10-20 wt% of the photoresist polymer; and 0.2-1 wt% of a photoacid generator.

Description

Chemically Amplified Negative Photoresist Polymer and Photoresist Composition {POLYMER FOR CHEMICAL AMPLIFICATION NEGATIVE PHOTORESIST AND PHOTORESIST COMPOSITION}

[Industrial use]

The present invention relates to a chemically amplified negative photoresist polymer and a photoresist composition, and more particularly to a chemically amplified negative photoresist composition capable of forming a high resolution pattern without swelling.

[Prior art]

Conventional photoresists used in the fabrication of semiconductor devices, as reported in U.S. Patent Nos. 3,666,473, 4,115,128, and 4,173,470, are novolak resins and photosensitive materials that are alkali soluble phenol- (or cresol-) formaldehyde resins. It consists of a naphthoquinone diazo type compound. However, as the wavelength of light used in the microfabrication technology shifts to 200-300 nm, which is the ultra-ultraviolet ray, the novolak resin-naphthoquinone diazide compound has a high light absorption in this light source region and has a low sensitivity. Not suitable for use

In the development of new photoresist, it is necessary to satisfy various requirements such as high sensitivity, high resolution, and dry etching resistance. Among them, sensitivity is the most important point in the development of photoresist, and chemically amplified The concept of amplification was introduced. In this chemical amplification, the active species generated by a single photochemical reaction act as a catalyst to continuously perform chemical reactions such as deprotection and crosslinking reactions, so that the total quantum yield of these reactions is larger than the quantum yield of initial catalyst formation. To have high sensitivity photoresist characteristics. Accordingly, in order to achieve high sensitivity in the lithography process of semiconductor manufacturing, recently, chemically amplified photoresists have received great attention, and among them, the resin having the greatest possibility is a polyvinylphenol resin-mine protected with t-butoxycarbonyl group. The third compound is described in US Pat. Nos. 4,311,782, 4,405,708 and 4,491,628.

Currently, photoresists required for the development of semiconductor chips with more than 1 gigabit DRAM are being actively researched. The light source uses an argon fluoride excimer laser having a wavelength of 193 nm. The conventional polyvinylphenol resin-photoacid generator compound protected with t-butoxycarbonyl has an aromatic ring, so that the light absorption is large and low at this wavelength. Can not be used. Therefore, a chemically amplified photoresist using an aliphatic ring compound has emerged to develop a photoresist having a high transmittance, high resolution and excellent dry etching resistance at 193 nm. Such photoresist is described in the form of attaching the alicyclic compound to the acrylic side chain or the addition of the alicyclic compound to the polymer as a dissolution inhibitor is described in US Patent Nos. 5,585,223, 5,691,111 and 5,756,850.

US Pat. No. 6,028,153 discloses a photoresist having an alicyclic compound in the polymer backbone by copolymerizing non-acrylic non-acrylic monomers with maleic anhydride.

U.S. Pat.Nos. 6,106,998, 6,074,801 and 5,955,241 describe chemically amplified negative photoresists using photoacid generators by using epoxy groups or alkoxymethylamide groups as functional groups that cause crosslinking reactions. Due to swelling phenomenon, the resolution is inferior to that of the positive photoresist.

It is an object of the present invention to provide a monomer for preparing a chemically amplified negative photoresist polymer that is free of swelling and capable of obtaining high resolution patterns.

Another object of the present invention is to provide a chemically amplified negative photoresist polymer which is free of swelling and is capable of obtaining high resolution patterns.

Still another object of the present invention is to provide a chemically amplified negative photoresist composition capable of obtaining a high-resolution pattern without the swelling phenomenon including the polymer and the photoacid generator.

In order to achieve the above object, the present invention provides a monomer of formula 1 and 2 for producing a chemically amplified negative photoresist polymer.

[Formula 1]

(In the above formula,

R ₁ and R ₂ are each independently H, CH ₃ , OH, CH ₂ OH, CO ₂ CH ₃ or CO ₂ C (CH ₃ ) ₃ ,

R ₃ is (R) _α (CH ₂ ) _β R 'or (R) _α ((CH ₂ ) _m O) _γ R' where R is CO, CO ₂ , O, OCO or OCO ₂ , and R 'Is O, CO ₂ or OCO ₂ , α is 0 or 1, β is 0 to 5, m is 1 or 2, and γ is 1 to 5),

R ₄ is a saturated alkyl, unsaturated alkyl, aromatic, ether, carbonyl, amine or alcohol group having 1 to 5 carbon atoms.)

[Formula 2]

(In the above formula,

R ₅ and R ₆ are the same as defined in R ₁ and R ₂ in the general formula (1),

R ₇ is (R) _α (CH ₂ ) _β or (R) _α ((CH ₂ ) _m O) _γ R ⁺ (where R is CO, CO ₂ , O, OCO or OCO ₂ , and R ⁺ is Is an alkyl group, α is 0 or 1, β is 0 to 5, m is 1 or 2, and γ is 1 to 5),

R ₈ and R ₉ are each independently H or OH.)

The present invention also provides a chemically amplified negative photoresist polymer prepared from the monomers of Formulas (1) and (2).

The present invention also provides a chemically amplified negative photoresist composition comprising the polymer and a photoacid generator.

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

The present invention provides monomers of the general formulas (1) and (2) below for producing novel norbornene-based polymers having acetal groups useful in photoresists that are free of swelling and can form high resolution patterns used in semiconductor microcircuit forming processes. do.

[Formula 1]

(In the above formula,

R ₁ and R ₂ are each independently H, CH ₃ , OH, CH ₂ OH, CO ₂ CH ₃ or CO ₂ C (CH ₃ ) ₃ ,

R ₃ is (R) _α (CH ₂ ) _β R 'or (R) _α ((CH ₂ ) _m O) _γ R' where R is CO, CO ₂ , O, OCO or OCO ₂ , and R 'Is O, CO ₂ or OCO ₂ , α is 0 or 1, β is 0 to 5, m is 1 or 2, and γ is 1 to 5),

R ₄ is a saturated alkyl, unsaturated alkyl, aromatic, ether, carbonyl, amine or alcohol group having 1 to 5 carbon atoms.)

[Formula 2]

(In the above formula,

R ₅ and R ₆ are the same as defined in R ₁ and R ₂ in the general formula (1),

R ₇ is (R) _α (CH ₂ ) _β or (R) _α ((CH ₂ ) _m O) _γ R ⁺ (where R is CO, CO ₂ , O, OCO or OCO ₂ , and R ⁺ is Is an alkyl group, α is 0 or 1, β is 0 to 5, m is 1 or 2, and γ is 1 to 5),

R ₈ and R ₉ are each independently H or OH.)

The norbornene-based monomer having an acetal group of Formula 1 is prepared by reacting an alcohol compound having an acetal group with a norbornene-based compound, and an alcohol compound having an acetal group is prepared by reacting aldehydes with glycerol. An example of the manufacturing method is as follows.

The removal of water while heating the reflux of aldehydes and glycerol in the presence of an acid such as paratoluenesulfonic acid with petroleum ether, benzene or toluene forming an azeotrope, produces a primary alcohol having an acetal group. When the norbornene-based compound, such as chlorocarbonyl-5-norbornene-based reaction, is reacted to prepare a monomer of Formula 1, which is a norbornene-based monomer having an acetal group.

Glycerol used in the preparation of the monomer of Chemical Formula 1 may be acetaldehyde, isobutyl aldehyde, butyl aldehyde, 2-metal butyl aldehyde, 2-ethyl butyl aldehyde, baler aldehyde, isovaleraldehyde, 3,3-dimethylbutyl aldehyde, 2 -Methyl valeraldehyde, 2,3-dimethyl valeraldehyde can be used. Since the reaction of the alcohol compound having the acetal group and the norbornene-based compound and the reaction of the aldehydes and glycerol are well known in the art, detailed descriptions thereof will be omitted.

The norbornene-based monomer having a bile acid derivative of Formula 2 is prepared by reacting a bile acid derivative with a norbornene-based compound. An example of the manufacturing method is as follows.

Bile acid derivatives such as cholic acid, deoxycholic acid, and lysocolic acid are dissolved in a solvent such as tetrahadifuran, and when a norbornene-based compound such as 2-chlorocarbonyl-5-norbornene is reacted to have a bile acid derivative. A monomer of Formula 2 is prepared, which is a norbornene monomer.

Monomers that can be copolymerized with the monomers of Formulas 1 and 2 include monomers of Formula 3 having intramolecular hydroxyl groups, monomers of Formula 4 having maleic carboxyl groups, and maleic anhydride.

[Formula 3]

[Formula 4]

(In Chemical Formulas 3 and 4,

R ₁₀ , R ₁₁ , R ₁₃ and R ₁₄ are the same as defined in R ₁ and R ₂ in Chemical Formula 1,

R ₁₂ and R ₁₅ are the same as defined in R ₇ in the formula (2).)

The photoresist polymer of the present invention may include copolymerized only with norbornene-based monomers having an acetal group represented by Chemical Formula 1 and include both monomers of Chemical Formula 1 and Chemical Formula 2.

Examples of the photoresist polymer including copolymerized only a norbornene-based monomer having an acetal group of Formula 1 include the following Formulas 5 to 6.

The polymer of Formula 5 is a terpolymer of a norbornene-based monomer having an acetal group of Formula 1, a monomer of Formula 3 having a hydroxyl group, and maleic anhydride.

[Formula 5]

The polymer represented by Formula 6 is a norbornene-based monomer having an acetal group of Formula 1, a monomer of Formula 3 having a hydroxyl group, a monomer of Formula 4 having a carboxyl group, and a quaternary copolymer of maleic anhydride.

[Formula 6]

Examples of the prepared photoresist polymer including both monomers of Formulas 1 and 2 include the following Formulas 7 to 10.

The polymer of Formula 7 is a terpolymer of a norbornene-based monomer having an acetal group of Formula 1, the monomer of Formula 2 and maleic anhydride.

[Formula 7]

The polymer of Formula 8 is a norbornene-based monomer having an acetal group of Formula 1, the monomer of Formula 2, the monomer of Formula 3 having a hydroxyl group, and a quaternary copolymer of maleic anhydride.

[Formula 8]

The polymer of Formula 9 is a norbornene-based monomer having an acetal group of Formula 1, a monomer of Formula 2, a monomer of Formula 10 having a carboxyl group and a quaternary copolymer of maleic anhydride.

[Formula 9]

The polymer of Formula 10 may be a norbornene-based monomer having an acetal group of Formula 1, a monomer of Formula 2, a monomer of Formula 3 having a hydroxyl group, a monomer of Formula 4 having a carboxyl group, and a maleic anhydride It is coalescing.

[Formula 10]

(In Chemical Formulas 5 to 10,

R ₁ , R ₂ , R ₁₀ , R ₁₁ , R ₁₃ and R ₁₄ are each independently H, CH ₃ , OH, CH ₂ OH, CO ₂ CH ₃ or CO ₂ C (CH ₃ ) ₃ ,

R ₃ is (R) _α (CH ₂ ) _β R 'or (R) _α ((CH ₂ ) _m O) _γ R' (where R is CO, CO ₂ , O, OCO or OCO ₂ , and R is 'Is O, CO ₂ or OCO ₂ , α is 0 or 1, β is 0 to 5, m is 1 or 2, and γ is 1 to 5),

R ₄ is a saturated alkyl, unsaturated alkyl, aromatic, ether, carbonyl, amine or alcohol group having 1 to 5 carbon atoms,

R ₇ , R ₁₂ and R ₁₅ are each independently (R) _α (CH ₂ ) _β or (R) _α ((CH ₂ ) _m O) _γ R ⁺ (where R is CO, CO ₂ , O, OCO or OCO ₂ , R ⁺ is an alkyl group, α is 0 or 1, β is 0 to 5, m is 1 or 2, γ is 1 to 5),

R ₈ and R ₉ are each independently H or OH,

a, b and c are the molar ratios of each monomer, a and b are 0.05 to 0.45, c is 0.5, a + b is 0.5,

d, e, g and f are the molar ratios of each monomer, d, e and f are 0.05 to 0.4, g is 0.5, d + e + f is 0.5,

h, i and j are the molar ratios of each monomer, h and i are 0.05 to 0.45, j is 0.5, h + i is 0.5,

p, q, r, s and t are the molar ratios of each monomer, p, q, r and s are 0.05 to 0.35, t is 0.5,

n is the degree of polymerization of each polymer has a value of 2 to 100,000.)

In the polymers of Formulas 5 to 10, the norbornene-based monomer having an acetal group of Formula 1 serves as a site for crosslinking reaction when heated in the presence of an acid, and the monomer having a steroid derivative of Formula 2 Providing the participating hydroxyl groups and increasing the dry etching resistance by the polycyclic ring, the monomer having a hydroxyl group of the formula (3) serves to control the reactivity of each, having a carboxyl group of the formula (4) The monomer plays a role of controlling sensitivity and developability, and maleic anhydride plays a role of alternating polymerization of norbornene-based monomers to form a polymer.

As the polymerization method of the polymers of the formulas (5) to (10), any general polymerization method such as cationic polymerization, anion polymerization, and radical polymerization can be used, and a radical polymerization method is preferable. The method of synthesizing the polymer of Chemical Formula 3 by the radical polymerization method is as follows.

A norbornene-based monomer having an acetal group of Formula 1, a monomer of Formula 3 having an intramolecular hydroxyl group and a maleic anhydride are dissolved in a solvent such as tetrahydrofuran, 2,2-azobisisobutyronitrile, By adding an organic solvent radical polymerization initiator such as benzoyl peroxide and t-butyl peroxide, the polymer of Chemical Formula 5 may be prepared by radical polymerization, and the polymers of Chemical Formulas 6 to 10 may be prepared in the same manner. Can be.

In the acetal polymer of the present invention, when heat is applied in the presence of an acid, a nucleophilic functional group such as a hydroxyl group or a carboxyl group attacks the acetal group so that a crosslinking reaction occurs.

In order to achieve high sensitivity in the process of forming microcircuits in semiconductor manufacturing, chemically amplified photoresists have been in the spotlight in recent years, and most of them are made of resins and photoacid generators that can chemically react with acids, and are suitable for them. Dissolve in solvent and use.

The action mechanism of the photoresist generates an acid when the photoacid generator receives ultraviolet light from the light source, and the generated acid acts as a catalyst for deprotection or crosslinking reaction with the polymer main chain or side chain. Through this reaction, the pattern is formed by making a difference in solubility in the developer of the exposed and unexposed portions.

Currently, photoresist is mainly used to obtain a positive image through an acid deprotection reaction. This is because the swelling of the polymer occurs during development in the case of a negative image acquisition method, and a high resolution pattern cannot be obtained. However, when the pattern is formed using the norbornene-based photoresist polymer having an acetal group of the present invention, swelling does not occur, thereby forming a high resolution pattern.

In the photoresist composition of the present invention, the content of the photoresist polymer of Formula 5 to 10 is preferably 10 to 20% by weight. When the content of the polymer is less than 10% by weight, the film thickness is too thin or the film is not formed properly, and when the content of the polymer is more than 20% by weight, it is difficult to form a uniform film by increasing the viscosity.

The photoresist polymer of Chemical Formulas 5 to 10 of the present invention may further include a photoacid generator to be used as a photoresist composition. The content of the photoacid generator in the photoresist polymer of the present invention is preferably 0.2 to 1% by weight. If the amount of the photoacid generator is less than 0.2% by weight, the amount of acid generated is small, so that crosslinking does not occur sufficiently. If the content of the photoacid generator exceeds 1% by weight, the sensitivity decreases due to the increase of the ultraviolet absorption of the photoacid generator itself. Not desirable

When the photoacid generator receives ultraviolet light from a light source, an acid is generated, and the acid generated in this polymer attacks the acetal group to cause a crosslinking reaction.

The photoacid generator may generate an acid upon receiving light, and is not particularly limited, but examples thereof include diphenyl iodo hexafluoro phosphate, diphenyl iodo hexafluoro arsenate, diphenyl iodo hexafluoro antimonate, and diphenyl iodide hexafluoro phosphate. Phenylparamethoxyphenyl triflate, diphenylparatoluethyl triflate, diphenylparaisobutylphenyl triflate, diphenylpara-t-butylphenyl triflate, triphenylsulfonium hexafluoro phosphate, triphenylsulfonium hexafluoro One or two or more sulfide-based or onium compounds may be used among arsenate, triphenylsulfonium hexafluor antimonate, triphenylsulfonium triflate, and dibutylnaphthylsulfonium triflate.

In addition, the photoresist composition of the present invention further includes an organic solvent in addition to the photoresist polymer and the photoacid generator. As the organic solvent, cyclohexanone, methyl-3-methoxypropionate, ethyl 3-ethoxypropionate, propylene glycol monomethyl ether acetate or other conventional organic solvent can be used.

In the method of forming a pattern using the photoresist composition, first, the photoresist polymer and the photoacid generator are dissolved in an organic solvent, and then selectively filtered through a filter to prepare a photoresist, and the photoresist is applied to a silicon wafer. . In the coating process, any coating method may be used as the general coating process, and spin coating is most preferable.

After coating, it is heat-treated (soft-bake) for 60 to 120 seconds in an oven or hot plate at 90 to 150 ° C., and exposed using an exposure apparatus or an excimer laser. The exposed wafers are post-baked for 60 to 120 seconds in a 90-150 ° C. oven or hot plate. Subsequently, the post-heat treated wafer is immersed in a developer for a predetermined time to form a photoresist pattern. As the developer, an aqueous tetramethylammonium solution, an aqueous potassium hydroxide solution, an aqueous potassium carbonate solution, an aqueous calcium carbonate solution, an aqueous sodium phosphate solution, an aqueous sodium silicate solution, an aqueous ammonia solution or an aqueous alkaline solution of an aqueous amine solution may be used alone or in combination of two or more thereof.

Hereinafter, preferred examples and comparative examples of the present invention are described. However, the following examples are only one preferred embodiment of the present invention and the present invention is not limited to the following examples.

Synthesis of Norbornene-Based Monomer Having Acetal Group

(Example 1)

14.4 g (0.2 mol) of butylaldehyde, 24 g (0.26 mol) of glycerol and 0.3 g of paratoluenesulfonic acid were mixed together with 60 g of petroleum ether in a 250 ml flask. A dean stark device was installed in the flask and refluxed at 90 ° C. for 6 hours to complete the reaction, and then the reaction product was extracted using water and ether. The obtained extract was fractionally distilled to obtain 23.1 g (yield 79%) of primary alcohol compound (FW = 146.19) having a pure acetal group.

21.9 g (0.15 mol) of the prepared primary alcohol compound and 20 g (0.2 mol) of triethylamine were dissolved in 30 g of purified tetrahydrofuran and placed in a 500 ml flask. 27 g (0.17 mol) of 2-chlorocarbonyl-5-norbornene series Was slowly dropped using a dropping funnel and stirred at room temperature for 6 hours. After completion of the reaction, the amine salt generated during the reaction was removed using a glass filter, and 24.8 g (yield 62%) of a norbornene-based monomer (FW = 266.33) having an acetal group represented by the following Formula 11 was obtained by using a tube chromatography method.

[Formula 11]

Synthesis of Norbornene-based Monomers Having Steroid Derivatives

(Example 2)

50 g (0.085 mol) of the compound represented by Chemical Formula 12 was dissolved in 200 ml of methylene chloride, and placed in a flask, and 150 ml of trifluoroacetic acid was slowly added dropwise using a dropping funnel while maintaining the temperature at 0 ° C. using an ice bath. After the reaction was stirred for 2 hours at 0 ℃. After completion of the reaction, neutralize the aqueous sodium hydrogen carbonate solution, extract the reaction product using methylene chloride and water, and use 3,02 g of a norbornene-based monomer (FW = 528.72) having a steroid derivative of Chemical Formula 13 by tube chromatography. 73%).

[Formula 12]

[Formula 13]

Polymer manufacturing

(Example 3)

5.33 g (0.02 mol) of the monomer of Formula 11, 3.64 g (0.02 mol) of 2-hydroxyethyl-5-norbornene-2-carboxylate and 3.92 g (0.04 mol) of maleic anhydride obtained in Example 1 ) Was dissolved in 30 g of tetrahydrofuran, 10 mol% of 2,2-azobisisobutyronitrile was added as a radical polymerization initiator, and the resultant was put in a polymerization ampoule and polymerized under vacuum at 60 ° C for 6 hours. After the polymerization, the reaction product was precipitated and recovered in petroleum ether, and then dried under reduced pressure at 40 ° C. for 6 hours to obtain 7.86 g (yield 61%) of the polymer of Chemical Formula 14. As a result of composition analysis and degree of polymerization analysis of Chemical Formula 14, a was 0.21, b was 0.29, c represented a value of 0.50, and polymerization degree n had a value of 130.

[Formula 14]

(Example 4)

5.33 g (0.02 mol) of monomers of Formula 11 obtained in Example 1, 2.73 g (0.015 mol) of 2-hydroxyethyl-5-norbornene-2-carboxylate and 5-norbornene-2-carbox 0.69 g (0.005 mole) of acid and 3.92 g (0.04 mole) of maleic anhydride are dissolved in 30 g of tetrahydrofuran, and 10 mole% of 2,2-azobisbutyronitrile is added to the polymerization ampoule as a radical polymerization initiator. 7.98 g (yield 63%) of the polymer of the following general formula (15) were obtained by the same method as in Example 3. As a result of composition analysis and degree of polymerization analysis of Chemical Formula 15, d is 0.20, e is 0.24, f is 0.06, g is 0.50, and polymerization degree n is 135.

[Formula 15]

(Example 5)

5.33 g (0.02 mol) of the monomer of Formula 11 obtained in Example 1, 10.57 g (0.02 mol) of the monomer of Formula 13 obtained in Example 2 and 3.92 g (0.04 mol) of maleic anhydride were 50 g of tetrahydrofuran It was dissolved in, and 10 mol% of 2,2-azobisbutyronitrile was added as a radical polymerization initiator, and it was put in the polymerization ampule and carried out in the same manner as in Example 3 to obtain 12.9 g (yield 65%) of the polymer of the following formula (16). . As a result of composition analysis and degree of polymerization analysis of Chemical Formula 16, h was 0.18, I was 0.32, j was 0.50, and polymerization degree n was 53.

[Formula 16]

(Example 6)

5.33 g (0.02 mol) of the monomer of Formula 11 obtained in Example 1, 7.93 g (0.015 mol) of the monomer of Formula 13 obtained in Example 2, and 2-hydroxyethyl-5-norbornene-based-2- 0.91 g (0.005 mole) of carboxylate and 3.92 g (0.04 mole) of maleic anhydride are dissolved in 50 g of tetrahydrofuran, and 10 mole% of 2,2-azobisbutyronitrile is added to the polymerization ampoule as a radical polymerization initiator. In the same manner as in Example 3, 12.1 g (yield 67%) of the polymer of the following general formula (17) was obtained. As a result of composition analysis and degree of polymerization analysis of Chemical Formula 17, k is 0.14, l is 0.27, m is 0.09, o is 0.50, and polymerization degree n is 59.

[Formula 17]

Photoresist Composition Preparation

(Example 7)

0.2 g of the compound of Chemical Formula 14 prepared in Example 3 and 0.004 g of the photo-acid generator triphenylsulfonium triplate were dissolved in propylene glycol monomethyl ether acetate 1.2 in a laboratory shielded from far ultraviolet rays, and then placed in a 0.2 μm syringe filter. Filtration once produced a photoresist composition.

(Example 8)

Except that the compound of Formula 15 prepared in Example 4 0.2g was used in the same manner as in Example 7.

(Example 9)

Except that the compound of Formula 16 prepared in Example 5 0.2g was used in the same manner as in Example 7.

(Example 10)

Except that the compound of Formula 17 prepared in Example 6 0.2g was used in the same manner as in Example 7.

Pattern formation

(Example 11)

After dropping the hexamethyldisilazane solution on the silicon wafer, spin-coating was performed at 1,500 rpm for 30 seconds and heat-treated at 110 ° C. for 90 seconds to pretreat the silicon wafer. Subsequently, the photoresist composition of Example 7 was dropped on the pretreated silicon wafer, spin-coated at 2,000 rpm for 60 seconds, and heat-treated at 110 ° C. for 90 seconds to prepare a thin film having a thickness of 0.35 μm. The formed thin film was irradiated with an exposure amount of 20 m / cm 2 using an ultraviolet exposure apparatus, and then subjected to post-heat treatment for 90 seconds on a 110 ° C. hot plate. The post-heat-treated wafer was immersed in an aqueous solution of 2.38% by weight of tetratrimethyl ammonium hydroxide for 90 seconds to form a negative pattern having a resolution of 0.6 µm.

(Example 12)

The same process as in Example 11 was carried out except that the photoresist composition of Example 8 was used.

(Example 13)

Except for using the photoresist composition of Example 9 was carried out in the same manner as in Example 11.

(Example 14)

Except for using the photoresist composition of Example 10 was carried out in the same manner as in Example 11.

When the photoresist is prepared using the chemically amplified negative photoresist polymer and the photoresist composition of the present invention, the crosslinking density is so large that the difference in solubility in the developer of the exposed portion and the non-exposed portion is very large, so that a negative pattern having excellent sensitivity can be obtained. In addition, there is no swelling phenomenon at the time of development, thereby obtaining a pattern having excellent pattern shape and high resolution.

Claims (7)

Norbornene-based monomer having an acetal group of formula (1) for producing a chemically amplified negative photoresist polymer. [Formula 1] (In the above formula, R ₁ and R ₂ are each independently H, CH ₃ , OH, CH ₂ OH, CO ₂ CH ₃ or CO ₂ C (CH ₃ ) ₃ , R ₃ is (R) _α (CH ₂ ) _β R 'or (R) _α ((CH ₂ ) _m O) _γ R' where R is CO, CO ₂ , O, OCO or OCO ₂ , and R 'Is O, CO ₂ or OCO ₂ , α is 0 or 1, β is 0 to 5, m is 1 or 2, and γ is 1 to 5), R ₄ is a saturated alkyl, unsaturated alkyl, aromatic, ether, carbonyl, amine or alcohol group having 1 to 5 carbon atoms.) Monomer of Formula 2 for preparing a chemically amplified negative photoresist polymer. [Formula 2] (In the above formula, R ₅ and R ₆ are the same as defined in R ₁ and R ₂ in the general formula (1), R ₇ is (R) _α (CH ₂ ) _β or (R) _α ((CH ₂ ) _m O) _γ R ⁺ (where R is CO, CO ₂ , O, OCO or OCO ₂ , and R ⁺ is Is an alkyl group, α is 0 or 1, β is 0 to 5, m is 1 or 2, and γ is 1 to 5), R ₈ and R ₉ are each independently H or OH.) A photoresist polymer comprising a monomer of the formula (1). [Formula 1] (In the above formula, R ₁ and R ₂ are each independently H, CH ₃ , OH, CH ₂ OH, CO ₂ CH ₃ or CO ₂ C (CH ₃ ) ₃ , R ₃ is (R) _α (CH ₂ ) _β R 'or (R) _α ((CH ₂ ) _m O) _γ R' where R is CO, CO ₂ , O, OCO or OCO ₂ , and R 'Is O, CO ₂ or OCO ₂ , α is 0 or 1, β is 0 to 5, m is 1 or 2, and γ is 1 to 5), R ₄ is a saturated alkyl, unsaturated alkyl, aromatic, ether, carbonyl, amine or alcohol group having 1 to 5 carbon atoms.) The photoresist polymer of claim 3, wherein the photoresist polymer is represented by the following Chemical Formulas 5-10. [Formula 5] [Formula 6] [Formula 7] [Formula 8] [Formula 9] [Formula 10] (In Chemical Formulas 5 to 10, R ₁ , R ₂ , R ₁₀ , R ₁₁ , R ₁₃ and R ₁₄ are each independently H, CH ₃ , OH, CH ₂ OH, CO ₂ CH ₃ or CO ₂ C (CH ₃ ) ₃ , R ₃ is (R) _α (CH ₂ ) _β R 'or (R) _α ((CH ₂ ) _m O) _γ R' (where R is CO, CO ₂ , O, OCO or OCO ₂ , and R is 'Is O, CO ₂ or OCO ₂ , α is 0 or 1, β is 0 to 5, m is 1 or 2, and γ is 1 to 5), R ₄ is a saturated alkyl, unsaturated alkyl, aromatic, ether, carbonyl, amine or alcohol group having 1 to 5 carbon atoms, R ₇ , R ₁₂ and R ₁₅ are each independently (R) _α (CH ₂ ) _β or (R) _α ((CH ₂ ) _m O) _γ R ⁺ (where R is CO, CO ₂ , O, OCO or OCO ₂ , R ⁺ is an alkyl group, α is 0 or 1, β is 0 to 5, m is 1 or 2, γ is 1 to 5), R ₈ and R ₉ are each independently H or OH, a, b and c are the molar ratios of each monomer, a and b are 0.05 to 0.45, c is 0.5, a + b is 0.5, d, e, g and f are the molar ratios of each monomer, d, e and f are 0.05 to 0.4, g is 0.5, d + e + f is 0.5, h, i and j are the molar ratios of each monomer, h and i are 0.05 to 0.45, j is 0.5, h + i is 0.5, p, q, r, s and t are the molar ratios of each monomer, p, q, r and s are 0.05 to 0.35, t is 0.5, n is the degree of polymerization of each polymer has a value of 2 to 100,000.) A photoresist composition comprising the photoresist polymer according to claim 3 or 4 and a photoacid generator. The photoresist composition of claim 5, wherein the photoresist composition comprises 10 to 20 wt% of the photoresist polymer. The photoresist composition of claim 5, wherein the photoresist composition comprises 0.2 to 1 wt% of a photoacid generator.