KR101204915B1 - Photoresist Polymer, Photoresist Composition Comprising the Same and Method for Forming Photoresist Pattern Using It - Google Patents

Abstract

The present invention relates to a photoresist polymer, a photoresist composition comprising the polymer, and a method of forming a pattern of a photoresist using the same, and more particularly, a photoresist polymer and a photoresist comprising a polymerization repeating unit represented by the following Chemical Formula 1 By providing a photoresist composition comprising a mixed solution of water and an alcohol compound as a resist polymer, a photoacid generator, a basic compound, and a solvent, and developing the photoresist film formed using the same, the process is simplified and the cost is reduced. It relates to a method of forming a pattern of photoresist which can be imported.

[Formula 1]

Wherein, R ₁ is a linear or branched alkylene group of C ₁ ~ C _10, n is an integer from 1 to 10, a unit of the molar ratio of b units of from 5 to 95: 95 to 5.

Description

Photoresist polymer, photoresist composition comprising same, and pattern formation method of photoresist using the same {Photoresist Polymer, Photoresist Composition Comprising the Same and Method for Forming Photoresist Pattern Using It}

1 is NMR data of a polymer obtained in Example 1 of the present invention.

2 is a pattern photograph according to Embodiment 2 of the present invention.

3 is a pattern photograph according to Embodiment 3 of the present invention.

The present invention relates to a photoresist polymer, a photoresist composition comprising the polymer and a method of forming a pattern of the photoresist using the same, and more particularly, a photoresist polymer and a photoresist comprising a polymerization repeating unit represented by Formula 1 A photoresist composition comprising a mixed solution of water and an alcohol compound as a polymer, a photoacid generator, a basic compound, and a solvent, and a photoresist film formed using the same, are developed using water, thereby simplifying the process and reducing the cost. It relates to a pattern formation method of.

Today, as the semiconductor manufacturing process is rapidly advanced to high integration, the application field of memory devices is expanded, and there is an urgent need for development of equipment or process technology corresponding thereto. In this regard, various studies have been conducted to develop a lithography process for manufacturing a semiconductor device, to study a cell structure, to develop a new material for forming a wiring, and to overcome the physical property limitations of an insulating film forming material.

Among them, the lithography process is an essential technology applied in a contact formation process or a pattern formation process that connects various layers constituting the device to each other, and the improvement of the lithography process technology is a key to determining the success or failure of the highly integrated semiconductor device.

For reference, the lithography process is chemically amplified photo having a short wavelength light source such as KrF (365 nm), ArF (193 nm) or VUV (157 nm) and low light absorption, excellent dry etching resistance, heat resistance and adhesion to the light source. A process of forming a device including a pattern critical dimension (CD) of 0.01 μm or less using a chemically amplified photoresist material.

In this case, the chemically amplified photoresist material may be divided into a negative photoresist material and a positive photoresist material.

More specifically, since the positive type photoresist material has not only higher pattern transfer characteristics and solubility in alkaline developing solutions than the negative type photoresist material, but also high resolution capable of accurately transferring an image from an exposure mask to a substrate during exposure, It is widely used in the lithography process. However, the positive type photoresist material has a high aspect ratio when the coating thickness is increased, resulting in the collapse of the pattern, and when the coating thickness is low, the etching resistance becomes low, making it difficult to perform the subsequent process. There are disadvantages.

In this regard, the development of lithographic process technology using negative photoresist materials that cause photoreactions that are sensitive to even lower exposure energy than the positive photoresist materials has recently been studied.

The negative photoresist material mainly includes an acidic alcohol group and a carboxylic acid group, and an alkaline developer such as trimethylammonium hydride (TMAH) is used in the post-exposure developing process.

At this time, the alkaline developer has low wettability with respect to the surface of the negative photoresist material and does not sufficiently penetrate into the fine negative photoresist pattern. Not suitable for use in the required process.

In order to improve this problem, a method of increasing the basic concentration of the alkaline developer, increasing the development temperature and time during the development process, or further including an additive such as hydrazine or a surfactant in the developer has been developed. However, these methods cause environmental pollution by the high basicity of the developing solution, and since the washing step of washing the pattern formed after the developing process with water is essential, the process step is complicated and the cost is increased, thus the effective system efficiency ( throughput cannot be obtained.

Therefore, the inventors of the present invention satisfy all the conditions such as low light absorption, excellent etching resistance, heat resistance and adhesion that a general photoresist material must have while studying the above problems, while simplifying the process and reducing cost. The present invention has been completed by developing a novel photoresist polymer and a photoresist composition including the polymer and a pattern forming method using the same.

The present invention is to solve the problems occurring during the development process in the lithography process using a conventional negative photoresist material as described above, the photoresist polymer of the novel configuration and the photoresist polymer and photoacid generator, basic compound and It is an object of the present invention to provide a negative photoresist composition comprising a water-insoluble compound as a solvent, thereby forming a compound insoluble in water during the post-exposure bake process.

Moreover, an object of this invention is to provide the method of forming a negative photoresist pattern using the said photoresist composition, and the semiconductor element obtained by such a method.

In order to achieve the above object,

The present invention provides a photoresist polymer comprising a compound of Formula 1 as a polymerization repeating unit.

[Formula 1]

Where

R ₁ is C ₁ to C ₁₀ linear or branched alkylene,

n is an integer from 1 to 10,

The molar ratio of a unit: b unit is 5-95: 95-5.

At this time, it is preferable that the photoresist polymer including the polymerization repeating unit represented by the formula (1) has a structure represented by the following formula (1a), and the weight average molecular weight of such a photoresist polymer is preferably 2,000 to 300,000.

[Formula 1a]

Where

The molar ratio of a unit: b unit is 5-95: 95-5.

In the present invention,

(a) mixing the compound of Formula 2 and the compound of Formula 3 into a polymerization solvent; And

(b) polymerizing a mixture of the compound of Formula 2 and the compound of Formula 3 in the presence of a polymerization initiator to provide a method of producing a photoresist polymer, characterized in that it comprises the step of preparing a polymer of the formula (1).

[Formula 2]

(3)

Where

R ₁ is C ₁ to C ₁₀ linear or branched alkylene,

n is 0 or 1 to 10.

At this time, the polymerization solvent for performing the polymerization reaction of the present invention is not particularly limited as long as it is a solvent that can dissolve the compounds, cyclohexanone, cyclopentanone, tetrahydrofuran, dimethylformamide, dimethyl sulfoxide Preference is given to using at least one polymerization solvent selected from the group consisting of sides, dioxane, methylethylketone, benzene, toluene and xylene. The amount of the polymerization solvent is not particularly limited as long as it is an amount in which both the compound of Formula 2 and the compound of Formula 3 that are reactants are dissolved and reacted.

The polymerization initiators are benzoyl peroxide, 2,2'-azobisisobutyronitrile (AIBN), acetyl peroxide, lauryl peroxide, t-butyl peracetate, t-butyl hydroperoxide and di-t-butyl Preference is given to those selected from the group consisting of peroxides.

In addition, in the present invention, a photoresist composition including a mixed solution of water and an alcohol compound as a photoresist polymer, a photoacid generator, a basic compound, and a solvent comprising a polymerization repeating unit of Chemical Formula 1 is prepared.

At this time, the photoacid generator is not particularly limited as long as it can play the role of a compound capable of generating an acid by light, US 5,212,043 (May 18, 1993), WO 97/33198 (September 12, 1997) ), WO 96/37526 (Nov. 28, 1996), EP 0794458 (September 10, 1997), EP 0789278 (August 13, 1997), US 5,750,680 (May 12, 1998), US 6,051,678 (2000. 4) 18), GB 2,345,286 A (July 5, 2000), US 6,132,926 (October 17, 2000), US 6,143,463 (November 7, 2000), US 6,150,069 (November 21, 2000), US 6.180.316 B1 (January 30, 2001), US 6,225,020 B1 (May 1, 2001), US 6,235,448 B1 (May 22, 2001) and US 6,235,447 B1 (May 22, 2001) and the like, for example, phthalimido tree Fluoromethanesulfonate, dinitrobenzyltosylate, n-decyldisulfone, naphthylimidotrifluoromethanesulfonate, diphenyliodo salt hexafluorophosphate, diphenyliodo salt hexafluoro arsenate, diphenyliodo salt hexa Fluoro antimonate, diphenylparame Cyphenylsulfonium triflate, diphenylparatoluenylsulfonium triflate, diphenylparaisobutylphenylsulfonium triflate, triphenylsulfonium hexafluoro arsenate, triphenylsulfonium hexafluoro antimonate, One or more photoacid generators selected from the group consisting of triphenylsulfonium triflate and dibutylnaphthylsulfonium triflate can be used.

The content of the photoacid generator in the photoresist composition of the present invention is preferably used in a ratio of 0.05 to 10 parts by weight based on 100 parts by weight of the photoresist polymer. If the photoacid generator is used at less than 0.05 parts by weight, the sensitivity of the photoresist to light is weak. If the photoacid generator is used at an amount exceeding 10 parts by weight, the photoacid generator absorbs a lot of ultraviolet rays and generates a large amount of acid, resulting in a bad pattern. Is formed.

In addition, the basic compound is not particularly limited as long as it is a compound capable of reacting with the photoresist polymer to form a salt, it is preferably selected from the group consisting of amine compounds and ammonium compounds. Preferably, the amine compound is a C ₁ to C ₁₀ alkylamine such as trimethylamine, triethylamine or trioctylamine, and the ammonium compound is ammonium hydroxide, trimethylammonium hydroxide, tetramethylammonium hydroxide Or C ₁ to C ₁₀ alkylammonium hydroxides such as tetrabutylammonium hydroxide.

The content of the basic compound in the photoresist composition of the present invention is preferably, for example, 5 to 100 molar ratio with respect to 100 moles of the photoresist polymer. In this case, when the content of the basic compound is less than 5 molar ratio, the effect of dissolving the unexposed photoresist composition in water, which is the developer during the subsequent development process, is weak.If it is included in excess of 100 molar ratio, all the acid in the exposed portion is neutralized and The resist composition is all dissolved in water.

In addition, the mixed solution of water and alcohol compound is a solvent for facilitating the mixing of the photoresist polymer and photoacid generator of the present invention, the content of the mixed solution of water and alcohol compound in the photoresist composition of the present invention is, for example It is preferably included in 300 to 1500 parts by weight based on 100 parts by weight of the photoresist polymer.

In this case, the mixed solution of the water and the alcohol compound is preferably 1 to 99% by weight: 99 to 1% by weight of water: alcohol compound, the alcohol compound is not particularly limited, C, such as isopropyl alcohol is alkyl of ₁ to C ₁₀ alcohol compound is preferable.

Scheme 1 below describes the reactions that occur when the photoresist composition of the present invention is used in the process of forming a photoresist pattern.

[Reaction Scheme 1]

Where

R ₁ is C ₁ to C ₁₀ linear or branched alkylene,

R₂, R₃, R₄ And R₅H or C_One～ C₁₀Linear or branched alkyl of

n is an integer from 1 to 10,

a unit: The molar ratio of b unit is 5-95: 95-5,

c unit: d unit: molar ratio of b unit is 3-50: 2-45: 95-5,

e unit: f unit: The molar ratio of b unit is 4-45: 1-50: 95-5.

As shown in Scheme 1 above, addition of a basic compound such as an amine or an ammonium compound to the photoresist polymer of the present invention forms a salt with the polymer, which is dissolved in water. After applying the photoresist composition on the etched layer and performing the exposure (h v ) and the baking process (△), the salt compound portion of the photoresist polymer is neutralized by the acid generated from the photoacid generator in the exposed region. An insoluble compound is formed that includes a maleic anhydride structure that does not dissolve in. Subsequently, when the development process using water is performed, the exposure region in which the insoluble compound is formed remains, and the non-exposure region having high solubility in water is removed, thereby obtaining a negative photoresist pattern having a high precision of a pattern profile and line width. .

As described above, since the pattern formation method using the photoresist composition of the present invention can be developed using water, the development process and subsequent cleaning process performed in the conventional pattern formation process can be shortened in one step, thereby simplifying the process and cost. It can bring savings.

Moreover, the photoresist composition of the present invention which performs the above reaction has excellent transmittance, etching resistance, heat resistance, adhesiveness and low light absorption at wavelengths around 157 nm to 248 nm.

In the present invention,

(a) coating the photoresist composition of the present invention on the etched layer to form a photoresist film;

(b) exposing and then baking the photoresist film; And

(c) providing a photoresist pattern forming method comprising forming a photoresist pattern by performing a developing process using water as a developer.

In the above process, it may further comprise the step of performing a baking process before the exposure of step (b), the baking process is carried out at 70 to 200 ℃.

The exposure process is an exposure of 1 to 100mJ / cm ² using a light source selected from the group consisting of KrF (248 nm), ArF (193 nm), VUV (157 nm), EUV (13 nm), E-beam, X-ray and ion beam. It is preferably carried out with energy.

In addition, the developing step is performed by spraying water at room temperature without immersing the wafer in water, thereby removing all photoresist patterns of the non-exposed areas.

In addition, the present invention provides a semiconductor device manufactured by using the photoresist pattern forming method using the composition of the present invention.

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

I. Photoresist Polymer

Example 1 Preparation of Polymer of Formula 1a

Compounds of Formula 2 (Aldrich Co., CAS No. 110-17-8) (0.1 mol), Compounds of Formula 3 (n = 2 and R ₁ = CH ₂ ) (Aldrich Co.) (0.12 mol) and AIBN ( 0.2 g) was dissolved in tetrahydrofuran (30 ml) and reacted at 65 ° C for 10 hours. After completion of the reaction, the solution was purified by hexane (200ml) to obtain the polymer of Formula 1a (yield 49%) (see Fig. 1).

II. Photoresist Composition and Photoresist Pattern Formation

Example 2.

The compound of Example 1 (10 g), trioctylamine aqueous solution (1 g) (Aldrich Co.), and triphenylsulfonium triflate (0.5 g) were added to a mixed solution of water (100 g) and isopropyl alcohol (10 g). After melt | dissolution, it filtered with the 0.20 micrometer filter and obtained the photoresist composition.

The prepared photoresist composition was spin coated on a silicon wafer, and then baked at 80 ° C. for 90 seconds. After the baking process, the resultant was exposed to an ArF light source and then baked again at 80 ° C. for 90 seconds.

After baking was completed by spraying water at room temperature for 40 seconds to obtain a negative L / S pattern of 3㎛ (see Fig. 2).

Example 3.

The compound of Example 1 (10 g), 10% aqueous trimethylammonium hydroxide solution (2.2 g) (Aldrich Co.), and triphenylsulfonium triflate (0.5 g) were mixed with water (100 g) and isopropyl alcohol ( 10 g) was dissolved in a mixed solution, and filtered through a 0.20 μm filter to obtain a photoresist composition.

The prepared photoresist composition was spin coated on a silicon wafer, and then baked at 80 ° C. for 90 seconds. After the baking process, the resultant was exposed to an ArF light source and then baked again at 80 ° C. for 90 seconds.

After baking was completed by spraying water at room temperature for 40 seconds to develop a negative L / S pattern of 3㎛ (see Figure 3).

As described above, since the photoresist film using the photoresist composition including the photoresist polymer including the compound of Formula 1 has physical properties in which the non-exposed areas are dissolved in water, water is used without using a basic developer. The developing process can be used to shorten the subsequent developing process and cleaning process performed in the existing pattern forming process in one step, which can simplify the process and reduce the cost, and also the environmental pollution caused by the basic developer. You can prevent it.

In addition, since the photoresist polymer of the present invention has excellent transmittance, etching resistance, heat resistance, adhesion, and low light absorption at 356 nm and 248 nm wavelengths, it is possible to form a pattern having improved uniformity.

Claims (19)

A photoresist polymer comprising a polymerized repeating unit represented by Formula 1 below: [Formula 1]

(Wherein, R ₁ is C ₁ to C ₁₀ linear or branched alkylene, n is an integer from 1 to 10, a unit: molar ratio of b unit is 5 ~ 95: 95 ~ 5). Claim 2 has been abandoned due to the setting registration fee. The method of claim 1, The photoresist polymer of Formula 1 is a photoresist polymer, characterized in that [Formula 1a]

(In the above formula, the molar ratio of a unit: b unit is 5 to 95:95 to 5). Claim 3 has been abandoned due to the setting registration fee. The method of claim 1, The weight average molecular weight of the said photoresist polymer is 2,000-300,000, The photoresist polymer characterized by the above-mentioned. (a) mixing the compound of Formula 2 and the compound of Formula 3 into a polymerization solvent; And (b) polymerizing a mixture of the compound of Formula 2 and the compound of Formula 3 in the presence of a polymerization initiator to produce a polymer of Formula 1 below. [Formula 1]

[Formula 2]

(3)

(Wherein, R ₁ is C ₁ to C ₁₀ linear or branched alkylene, n is an integer from 1 to 10, a unit: molar ratio of b unit is 5 ~ 95: 95 ~ 5). Claim 5 was abandoned upon payment of a set-up fee. 5. The method of claim 4, Claim 6 has been abandoned due to the setting registration fee. 5. The method of claim 4, The polymerization initiators are benzoyl peroxide, 2,2'-azobisisobutyronitrile (AIBN), acetyl peroxide, lauryl peroxide, t-butyl peracetate, t-butyl hydroperoxide and di-t-butyl A method for producing a photoresist polymer, characterized in that selected from the group consisting of peroxides. A photoresist composition comprising a mixed solution of water and an alcohol compound as the photoresist polymer, photoacid generator, basic compound and solvent of claim 1. Claim 8 was abandoned when the registration fee was paid. The method of claim 7, wherein The photoacid generator is phthalimidotrifluoromethanesulfonate, dinitrobenzyltosylate, n-decyldisulfone, naphthylimidotrifluoromethanesulfonate, diphenyl iodo salt hexafluorophosphate, diphenyl iodo salt hexafluoro Arsenate, Diphenyl iodo salt hexafluoro antimonate, Diphenyl paramethoxy phenylsulfonium triflate, Diphenyl para toluenyl sulfonium triflate, Diphenyl paraisobutyl phenyl sulfonium triflate, triphenylsul Photoresist composition, characterized in that at least one selected from the group consisting of phonium hexafluoro arsenate, triphenylsulfonium hexafluoro antimonate, triphenylsulfonium triflate and dibutylnaphthylsulfonium triflate. Claim 9 has been abandoned due to the setting registration fee. The method of claim 7, wherein The photoresist composition is a photoresist composition, characterized in that contained in 0.05 to 10 parts by weight based on 100 parts by weight of the photoresist polymer. Claim 10 has been abandoned due to the setting registration fee. The method of claim 7, wherein The basic compound is a photoresist composition, characterized in that selected from the group consisting of amine compounds and ammonium compounds. Claim 11 was abandoned upon payment of a setup registration fee. 11. The method of claim 10, The amine compound is a photoresist composition, characterized in that alkyl amines of C ₁ ~ C _10. Claim 12 is abandoned in setting registration fee. 11. The method of claim 10, The ammonium compound is the photoresist composition, characterized in that an alkyl ammonium hydroxide of C ₁ ~ C _10. Claim 13 was abandoned upon payment of a registration fee. The method of claim 7, wherein The basic compound is a photoresist composition, characterized in that contained in 5 to 100 molar ratio with respect to 100 moles of the photoresist polymer. Claim 14 has been abandoned due to the setting registration fee. The method of claim 7, wherein The mixed solution of the water and the alcohol compound is 300 to 1500 parts by weight based on 100 parts by weight of the photoresist polymer. Claim 15 is abandoned in the setting registration fee payment. The method of claim 7, wherein The mixed solution of the water and the alcohol compound is a water: alcohol compound 1 to 99% by weight: 99 to 1% by weight mixed photoresist composition, characterized in that. Claim 16 has been abandoned due to the setting registration fee. The method of claim 7, wherein The alcohol compound is the photoresist composition, characterized in that an alkyl alcohol of C ₁ ~ C _10. (a) applying the photoresist composition of claim 7 over the etched layer to form a photoresist film; (b) exposing and baking the photoresist film; And (c) forming a photoresist pattern by performing a developing process using water as a developing solution. Claim 18 has been abandoned due to the setting registration fee. The method of claim 17, The (c) developing step is a photoresist pattern forming method, characterized in that is carried out by spraying water at room temperature. A semiconductor device manufactured using the pattern forming method of claim 17.

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