KR101677058B1 - Polyacetal resin, method of synthesizing polyacetal resin and photoresist composition - Google Patents

Abstract

Disclosed is a polyacetal resin, a method of synthesizing the same, and a photoresist composition comprising a polyacetal resin. For example, when a semiconductor device is manufactured using a photoresist composition comprising a polyacetal resin, which is a compound in the form of a monomolecular structure having an acid dissociable structure, lithography capable of forming a fine pattern, for example, EUV lithography High sensitivity, high resolution, high etching resistance and low out gas amount of the photoresist can be improved, and a good photoresist pattern shape can be obtained.

Description

TECHNICAL FIELD [0001] The present invention relates to a polyacetal resin, a method of synthesizing the same, and a photoresist composition.

More particularly, the present invention relates to a polyacetal resin used in the production of a semiconductor device, a method for synthesizing the same, and a photoresist composition comprising a polyacetal resin.

With the high integration of semiconductor devices, ultrafine patterns of 0.10 mu m or less are required in the manufacture of ULSI (ultra large scale integration) and the like. Accordingly, the exposure wavelength is further shortened in the conventional g line or i line area, and research on lithography using deep ultraviolet, KrF excimer laser, ArF excimer laser, EUV, X-ray and electron beam has been attracting attention. In particular, electron beam lithography is a next generation pattern forming technique, and development of a high sensitivity and high resolution photoresist in response to the demand has been demanded.

The high sensitivity of the photoresist is related to the power source of the electron beam. That is, the better the sensitivity, the smaller the power supply can define, but the lower the sensitivity, the higher the power supply is needed, so there is also a direct relationship with the processing speed of the wafer. However, since the sensitivity, resolution, and line edge roughness are in a trade-off relationship with each other in the electron beam photoresist, high sensitivity can deteriorate the resolution of the line as well as the line edge roughness . For this reason, there is a strong demand for the development of a resist which simultaneously satisfies the characteristics such as sensitivity, resolution and line edge roughness.

One aspect of the present invention is to provide a polyacetal resin which can provide a high sensitivity, high resolution, high etching resistance, low out gas amount and shape of the obtained photoresist pattern of a photoresist required for lithography capable of forming a fine pattern, And a photoresist composition comprising a polyacetal resin.

A polyacetal resin according to one aspect of the present invention is a compound represented by the following formula (1).

[Chemical Formula 1]

In Formula 1,

X and Y are each independently, C ₃ -C ₃₀ alkyl group, a part or the formula C ₃ -C ₃₀ cyclic alkyl group, an allyl group, C ₆ -C ₃₀ aryl group, or benzyl being odd, the C ₃ -C ₃₀ alkyl group , At least one hydrogen atom of a monocyclic or polycyclic C ₃ -C ₃₀ alkyl group, an allyl group, a C ₆ -C ₃₀ aryl group or a benzyl group is replaced by an ether group, an ester group, a carbonyl group, an acetal group, an epoxy group, substituted with the aldehyde groups are not included or include C ₁ -C ₁₀ alkyl group or a C ₁ -C ₁₀ alkoxy group, C ₁ -C ₄ as a purple low alkyl group, C ₁ -C ₁₀ hydroxyalkyl group or a cyano group, or is unsubstituted,

n is an integer of 1 to 20;

Here, the polyacetal resin may be, for example, a compound represented by the following general formula (2) or (3)

(2)

(3)

In the above Formulas 2 and 3,

n is an integer of 1 to 20, respectively.

The polyacetal resin may have a polystyrene reduced weight average molecular weight of 500 to 100,000.

Meanwhile, a method of synthesizing a polyacetal resin according to an aspect of the present invention includes polycondensing a compound represented by the following formula (4) and a compound represented by the following formula (5).

[Chemical Formula 4]

In Formula 4,

X is a C ₃ -C ₃₀ alkyl group, a monocyclic or polycyclic C ₃ -C ₃₀ alkyl group, an allyl group, a C ₆ -C ₃₀ aryl group or a benzyl group, the C ₃ -C ₃₀ alkyl group, the monocyclic or polycyclic At least one hydrogen atom of the C ₃ -C ₃₀ alkyl group, the allyl group, the C ₆ -C ₃₀ aryl group or the benzyl group includes or does not contain an ether group, an ester group, a carbonyl group, an acetal group, an epoxy group, a nitrile group or an aldehyde group A C ₁ -C ₁₀ alkyl group or a C ₁ -C ₁₀ alkoxy group, a C ₁ -C ₄ perfluoroalkyl group, a C ₁ -C ₁₀ hydroxyalkyl group or a cyano group.

[Chemical Formula 5]

In Formula 5,

Y is a C ₃ -C ₃₀ alkyl group, a monocyclic or polycyclic C ₃ -C ₃₀ alkyl group, an allyl group, a C ₆ -C ₃₀ aryl group or a benzyl group, the C ₃ -C ₃₀ alkyl group, the monocyclic or polycyclic At least one hydrogen atom of the C ₃ -C ₃₀ alkyl group, allyl group, C ₆ -C ₃₀ aryl group or benzyl group includes or includes an ether group, an ester group, a carbonyl group, an acetal group, an epoxy group, a nitrile group or an aldehyde group C ₁ -C ₁₀ alkyl or C ₁ -C ₁₀ alkoxy, C ₁ -C ₄ perfluoroalkyl, C ₁ -C ₁₀ hydroxyalkyl or cyano,

m is an integer of 1 to 2;

Here, the polycondensation can be carried out in the presence of an acid or an acid and a dehydrating agent.

The photoresist composition according to one aspect of the present invention includes a polyacetal resin represented by Formula 1, a photoacid generator, and a solvent.

Here, the polyacetal resin may be 3 to 20 parts by weight based on 100 parts by weight of the total photoresist composition.

Here, the photoacid generator may be 0.3 to 15 parts by weight based on 100 parts by weight of the total solid content of the photoresist composition.

According to one aspect of the present invention, lithography capable of forming a fine pattern, for example, a high sensitivity, high resolution, high etch resistance, and low outgassing characteristics of a photoresist required in EUV lithography can be satisfied, A pattern shape can be obtained.

Hereinafter, a polyacetal resin, a method of synthesizing the same, and a photoresist composition according to an aspect of the present invention will be described in detail.

Polyacetal  Suzy

The polyacetal resin is a compound represented by the following formula (1).

[Chemical Formula 1]

In Formula 1,

X and Y are each independently, C ₃ -C ₃₀ alkyl group, a part or the formula C ₃ -C ₃₀ cyclic alkyl group, an allyl group, C ₆ -C ₃₀ aryl group, or benzyl being odd, the C ₃ -C ₃₀ alkyl group , At least one hydrogen atom of a monocyclic or polycyclic C ₃ -C ₃₀ alkyl group, an allyl group, a C ₆ -C ₃₀ aryl group or a benzyl group is replaced by an ether group, an ester group, a carbonyl group, an acetal group, an epoxy group, substituted with the aldehyde groups are not included or include C ₁ -C ₁₀ alkyl group or a C ₁ -C ₁₀ alkoxy group, C ₁ -C ₄ as a purple low alkyl group, C ₁ -C ₁₀ hydroxyalkyl group or a cyano group, or is unsubstituted,

n is an integer of 1 to 20;

The polyacetal resin is a monomolecular compound having an acid dissociable structure and can be used as a component constituting the photoresist composition. The polyacetal resin is a kind of molecular glass resist which is not a radical copolymer which is one component of a conventional photoresist composition, and its molecular weight and the like are relatively smaller than those of the conventional radical copolymer. That is, the weight average molecular weight of the polyacetal resin in terms of polystyrene reduced by gel permeation chromatography (GPC) may be in the range of 500 to 100,000. In consideration of the sensitivity to photoresist, developability, coatability and heat resistance, 5,000 is preferred. When the weight average molecular weight of the polyacetal resin in terms of polystyrene is less than 500, the resist pattern may easily collapse or be deformed. When the polystyrene reduced weight average molecular weight exceeds 100,000, the resolution of the resist pattern may be lowered. The molecular weight distribution of the polyacetal resin is not particularly limited, but may be, for example, from 1 to 5, and preferably from 1 to 3.

Specific examples of the polyacetal resin include a compound represented by the following formula (2) or a compound represented by the following formula (3), but the present invention is not limited thereto.

(2)

(3)

In the above Formulas 2 and 3,

n is an integer of 1 to 20, respectively.

The polyacetal resin is insoluble or sparingly soluble in an aqueous alkali solution, but may also be soluble in some cases. The polyacetal resin may have an acid-sensitive functional group in the side chain portion, but may not have an acid-sensitive functional group in some cases.

The polyacetal resin may be a binary or polybasic copolymer. The polyacetal resin may be, for example, a block copolymer, a random copolymer or a graft copolymer. In addition, the polyacetal resin may have a branched structure as well as a linear structure, and may have a crosslinked structure. In addition, the polyacetal resin may be a single blend or a blend containing two or more blends in an arbitrary ratio.

The polyacetal resin can be synthesized, for example, by polycondensation of a compound represented by the following formula (4) and a compound represented by the following formula (5).

[Chemical Formula 4]

In Formula 4,

X is a C ₃ -C ₃₀ alkyl group, a monocyclic or polycyclic C ₃ -C ₃₀ alkyl group, an allyl group, a C ₆ -C ₃₀ aryl group or a benzyl group, the C ₃ -C ₃₀ alkyl group, the monocyclic or polycyclic At least one hydrogen atom of the C ₃ -C ₃₀ alkyl group, allyl group, C ₆ -C ₃₀ aryl group or benzyl group includes or includes an ether group, an ester group, a carbonyl group, an acetal group, an epoxy group, a nitrile group or an aldehyde group are not substituted by C ₁ -C ₁₀ alkyl group or a C ₁ -C ₁₀ alkoxy group, C ₁ -C ₄ alkyl group in the low purple, C ₁ -C ₁₀ hydroxyalkyl group, or cyano group or is unsubstituted.

[Chemical Formula 5]

In Formula 5,

Y is a C ₃ -C ₃₀ alkyl group, a monocyclic or polycyclic C ₃ -C ₃₀ alkyl group, an allyl group, a C ₆ -C ₃₀ aryl group or a benzyl group, the C ₃ -C ₃₀ alkyl group, the monocyclic or polycyclic At least one hydrogen atom of the C ₃ -C ₃₀ alkyl group, the allyl group, the C ₆ -C ₃₀ aryl group or the benzyl group includes or does not contain an ether group, an ester group, a carbonyl group, an acetal group, an epoxy group, a nitrile group or an aldehyde group A C ₁ -C ₁₀ alkyl group or a C ₁ -C ₁₀ alkoxy group, a C ₁ -C ₄ perfluoroalkyl group, a C ₁ -C ₁₀ hydroxyalkyl group or a cyano group,

m is an integer of 1 to 2;

The polycondensation may involve a dehydration condensation reaction carried out in the presence of an acid, or an acid and a dehydrating agent. Here, the acid is not particularly limited and, for example, p- toluenesulfonate acid (p-toluenesulfonic acid), hydrochloric acid (HCl), sulfuric acid (H ₂ SO _4), boron trifluoride (BF _3), etc. May be used alone or in combination of two or more. The dehydrating agent is not particularly limited, and for example, a trialkyl orthoformate can be used. Examples of the solvent that can be used in the polycondensation include water, alcohols (alkyl alcohol such as methanol, ethanol, propyl alcohol, etc.), ketones (dialkyl ketone such as acetone, etc.) , Ethers (such as dialkyl ethers such as diethyl ether), esters, and amides can be used alone or in combination of two or more. In addition, various solvents can be introduced. After completion of the polycondensation, the unreacted materials and by-products remaining in the reaction mixture are preferably removed by a precipitation method using a solvent.

Photoresist  Composition

A photoresist composition according to an aspect of the present invention includes a polyacetal resin represented by Formula 1, a photoacid generator, and a solvent. In addition, the photoresist composition may further include other additives as needed. The other additives are not particularly limited. For example, surfactants, water-soluble alcohols, basic additives, etc. may be used alone or in combination of two or more. Here, the polyacetal resin constituting the photoresist composition according to one aspect of the present invention is the same as that described above, so that a duplicate description will be omitted.

The content of the polyacetal resin may be 3 to 20 parts by weight based on 100 parts by weight of the entire photoresist composition. If the content of the polyacetal resin is less than 3 parts by weight based on 100 parts by weight of the total photoresist composition, the thickness of the resist film may become too thin to achieve a desired resist pattern thickness. If the content of the polyacetal resin exceeds 20 parts by weight, It can be thickened.

The photoacid generator is not particularly limited. For example, at least one of the compounds represented by the following formulas (6) and (7) can be used.

[Chemical Formula 6]

(7)

In the above formulas (6) and (7)

R ₁ and R ₂ each independently represent an alkyl group, an allyl group, a perfluoroalkyl group, a benzyl group or an aryl group,

R ₃ , R ₄ and R ₅ each independently represent a hydrogen atom, an alkyl group, a halogen group, an alkoxy group, an aryl group, a sioephenoxy group, a cyanoalkoxy group or an alkoxycarbonylmethoxy group,

A ^- is ^- OSO ₂ CF ₃ , ^- OSO ₂ C ₄ F ₉ , ^- OSO ₂ C ₈ F ₁₇ , ^- N (CF _{3) 2,} ^- N (C ₂ F ₅ ) ₂ , ^- N (C ₄ F ₉ ) ₂ , ^- C (CF _{3) 3,} ^- C (C ₂ F ₅ ) ₃ , _{^{- C (C 4 F 9)}} 3 , or Is a compound represented by the following formula (8).

[Chemical Formula 8]

In Formula 8,

X represents a monocyclic or polycyclic C ₃ -C ₃₀ hydrocarbon group, a benzyl group, a C ₆ -C ₂₀ aryl group, a C ₁ -C ₂₀ alkyl group, a C ₁ -C ₂₀ haloalkyl group, a C ₁ -C ₂₀ alkylsulfonyl group , C ₁ -C ₂₀ alkoxy group, C ₁ -C ₂₀ allyl group, or a cyano nogiyi being the part formula or is C ₃ -C ₃₀ cyclic hydrocarbon group, a benzyl group, C ₆ -C ₂₀ aryl group, C ₁ - C ₂₀ alkyl group, C ₁ -C ₂₀ haloalkyl group, C ₁ -C ₂₀ alkylsulfonyl, C ₁ -C ₂₀ alkoxy group or a C ₁ -C _20, at least one hydrogen atom of the allyl ether group, an ester group, a carbonyl group, An acetyl group, a nitrile group, a cyano group, a hydroxyl group, a carboxyl group, or an aldehyde group,

R is a C ₁ -C ₁₀ alkyl, C ₁ -C ₁₀ alkoxy group, a nitrogen atom, a sulfur atom, a fluorine atom or oxygen atom,

and m is an integer of 0 to 2.

Among the compounds represented by the above formulas (6) and (7), examples of the cation moiety include the compounds represented by the following formulas (9a) to (9p).

Examples of the compound represented by the formula (8) include compounds represented by the following formulas (10a) to (10l), (11a) to (11o), and (12a) to (12i).

The content of the photoacid generator may be 0.3 to 15 parts by weight, preferably 2 to 10 parts by weight based on 100 parts by weight of the total solid content of the photoresist composition. If the amount of the photo-acid generator is less than 0.3 parts by weight based on 100 parts by weight of the total solid content of the composition, the occurrence of acid is small and the resolution is reduced and the bending property of the pattern may deteriorate. The thickness loss of the upper portion of the resist film may become excessive, and the light absorbing agent of the photoacid generator may absorb a large amount of the resin, thereby decreasing the transparency of the resin, and the verticality of the pattern may be significantly deteriorated.

The solvent contained in the photoresist composition is not particularly limited as long as it dissolves solid components of the composition and has an appropriate drying rate and viscosity. Examples of the solvent include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether But are not limited to, ether, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, methyl isopropyl ketone, cyclohexanone, methyl 2- Ethyl 2-hydroxypropionate, 2-heptanone, ethyl lactate, and gamma-butyrolactone may be used alone or in combination of two or more. The amount of the solvent to be used can be adjusted to be uniformly formed on the wafer by using an appropriate amount depending on physical properties of the solvent, such as volatility, viscosity, and the like.

A method for forming a pattern on a substrate using the photoresist composition according to an aspect of the present invention will be described in detail as follows. Here, the pattern forming method may be a method for forming a photoresist pattern on the substrate, but the present invention is not limited thereto. For example, the present invention may include forming a pattern of a semiconductor device and / or a display device using the photoresist pattern, for example, a transistor, a capacitor, a metal wiring, and the like.

A method of forming a pattern according to an aspect of the present invention includes: forming a photoresist film by applying and drying the photoresist composition onto a substrate; selectively exposing the photoresist film; and developing the exposed photoresist film . Hereinafter, each step will be described in detail.

First, the photoresist composition is applied onto a substrate prepared as described above. The substrate is not particularly limited and may be selected arbitrarily from among, for example, a silicon wafer, a glass substrate, and a flexible substrate. The application method may be selected arbitrarily from a spin coating method, a dipping method, a spraying method, a transfer method, a flow application method, a roll application method and the like.

Next, the photoresist composition applied on the substrate is irradiated with light or heat is applied. Thereby, the solvent of the composition can be evaporated to form a photoresist film. At this time, hardening of the photoresist film may occur.

Next, the photoresist film is selectively exposed. Here, selective exposure means exposure to form a desired photoresist pattern. For example, a mask for forming a desired photoresist pattern upon selective exposure can be used. The light source at the time of exposure may be selected according to the type of the photoacid generator among the I-line which is ultraviolet ray, KrF excimer laser which is ultraviolet ray, ArF excimer laser, F2 excimer laser, X-ray and electron beam which is charged particle ray. After the exposure, the exposed photoresist film can be cured as needed.

Next, the exposed photoresist film is developed using a developer. Thereby, a photoresist pattern can be formed. Examples of the developer include aqueous solutions such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium methane silicate, aqueous ammonia, ethylamine, n-propylamine, triethylamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide And the like may be used alone or in combination of two or more. Among them, an aqueous solution containing tetramethylammonium hydroxide can be used.

According to one aspect of the present invention described above, it is possible to improve the properties of a photoresist required for lithography capable of forming a fine pattern, high sensitivity, high resolution, high etching resistance, low outgas amount characteristics, Can be obtained. Thus, a semiconductor device including an ultrafine pattern can be manufactured.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, You will understand.

Therefore, it should be understood that the above-described embodiments are provided so that those skilled in the art can fully understand the scope of the present invention. Therefore, it should be understood that the embodiments are to be considered in all respects as illustrative and not restrictive, The invention is only defined by the scope of the claims.

Claims (9)

delete delete delete delete delete A photoresist composition comprising a polyacetal resin represented by the following formula (2) or (3), a photoacid generator, and a solvent.

---- (2)

- (3) (In the above formulas 2 and 3, and n is an integer of 1 to 20, respectively. The method according to claim 6, Wherein the polyacetal resin is 3 to 20 parts by weight based on 100 parts by weight of the total photoresist composition. delete The method according to claim 6, Wherein the photoacid generator is 0.3 to 15 parts by weight based on 100 parts by weight of the total solid content of the photoresist composition.