KR101920783B1 - Photo-sensitive composition and method of forming pattern using the same - Google Patents

Abstract

A photo-sensitive resin composition of examples of the present invention contains an alkali-soluble resin, a photosensitizer, a development enhancer including a dioxane-based compound, and a solvent. Sensitivity and resolution thereof can be improved through the action of the development enhancer.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive resin composition and a pattern forming method using the same.

The present invention relates to a photosensitive resin composition and an insulating film formed therefrom. More particularly, the present invention relates to a photosensitive resin composition comprising a resin and a photosensitive component, and an insulating film formed from the photosensitive resin composition.

For example, a photosensitive resin composition is used to form various photocurable insulating patterns such as a photoresist, an insulating film, a protective film, a black matrix, and a column spacer of a display device or a semiconductor device. For example, an inorganic insulating film such as silicon oxide or silicon nitride has a high dielectric constant, and the demand for a low dielectric organic insulating film is increasing, and the photosensitive resin composition can be used for forming the organic insulating film.

The photosensitive resin composition is classified into a positive type and a negative type according to a portion removed by a developing process. In the positive-working composition, the exposed portion is dissolved by the developing solution, and in the negative-type composition, the unexposed portion may be dissolved to form a pattern.

2. Description of the Related Art In recent years, the resolution of a display device or a semiconductor device has been increasing, and the critical dimension (CD) of a pattern has rapidly become finer. Therefore, a photosensitive composition for forming an insulating film or an insulating pattern also needs to have improved sensitivity and resolution.

In order to form an insulation pattern with an improved resolution, it is necessary to increase the physical and chemical difference of the exposed portion and the non-exposed portion of the preliminary insulating film formed of, for example, a photosensitive resin composition, and the components of the photosensitive resin composition must be designed in consideration thereof .

For example, Korean Patent Laid-Open Publication No. 2013-0021324 discloses a positive resist composition, but the above-described high resolution exposure / development process may not be sufficiently realized.

Korean Patent Publication No. 10-2013-0021324

An object of the present invention is to provide a photosensitive resin composition of high resolution and high sensitivity.

An object of the present invention is to provide a pattern forming method using the above photosensitive resin composition.

1. Alkali-soluble resins; Photosensitizer; A development enhancer including a dioxane-based compound; And a solvent.

2. The photosensitive resin composition according to 1 above, wherein the dioxane-based compound comprises 1,4-dioxane.

3. The photosensitive resin composition according to 1 above, wherein the content of the development enhancer is 0.001 ppb to 1% by weight based on the total weight of the composition.

4. The photosensitive resin composition according to 1 above, wherein the photosensitive agent comprises a compound of diazonaphtha quinone (DNQ) or naphtoquinone diazide (NQD).

5. The photosensitive resin composition according to 1 above, wherein the alkali-soluble resin comprises a phenolic novolak resin or a cresol novolak resin.

6. A method for forming a photosensitive film, comprising: forming a photosensitive film on a substrate by applying a photosensitive resin composition comprising an alkali-soluble resin, a photosensitizer, a development enhancer including a dioxane compound, and a solvent; Exposing the photosensitive film to form an exposed portion and an unexposed portion; And removing the exposed portion through a developing process to form an insulating pattern.

7. The method of claim 6, further comprising: forming a film to be etched on the substrate before forming the photosensitive film; And etching the etching target film using the insulating pattern as an etching mask.

8. The pattern forming method according to 7 above, further comprising forming a buffer layer on the film to be etched.

9. The method of pattern 6 according to 6 above, wherein the development enhancer comprises 1,4-dioxane.

The photosensitive resin composition according to the embodiments of the present invention includes an alkali-soluble resin and a photosensitizer, and may further include a development promoter containing 1,4-dioxane. The solubility of the exposed portion is further increased by the development enhancer, and the developing resolution of the exposed portion and the non-exposed portion can be remarkably increased.

Since the development enhancer can effectively increase the difference in solubility only by adding a small amount of the development enhancer, the resolution and sensitivity can be effectively increased without deteriorating the chemical resistance, heat resistance, hardenability, and the like as the content of the alkali soluble resin is reduced.

1 to 5 are schematic sectional views for explaining a pattern forming method according to exemplary embodiments.

Embodiments of the present invention provide a photosensitive resin composition comprising an alkali-soluble resin, a photosensitizer, a development enhancer including 1,4-dioxane, and a solvent. For example, the photosensitive resin composition may be a composition based on a positive type photoactive compound (PAC).

In addition, embodiments of the present invention provide a pattern forming method using the above photosensitive resin composition.

Hereinafter, embodiments of the present invention will be described in detail.

<Photosensitive resin composition>

Alkali-soluble resin

The photosensitive composition according to exemplary embodiments may comprise an alkali-soluble resin as a base component. The alkali-soluble resin provides a basic skeleton of a photoresist film or an insulating film formed from the photosensitive composition, and can provide a difference in solubility by an exposure process.

The alkali-soluble resin may include, without limitation, a polymer material to be widely used in PAC-based photosensitive compositions. For example, the alkali-soluble resin may include a phenolic novolak resin or a cresol novolak resin.

For example, the alkali-soluble resin can be produced through the addition-condensation reaction of a phenolic compound and an aldehyde compound.

The adduct phenolic compounds include, for example, phenol, o-, m- and p-cresol, 2,5-xylenol, 3,5-xylenol, 3,4- Butylphenol, 3-t-butylphenol, 3-ethylphenol, 2-ethylphenol, 4-ethylphenol, 3-methyl-6-t- butylphenol, , 4-methyl-2-t-butylphenol, 2-naphthol, 1,3-dihydroxynaphthalene, 1,7-dihydroxynaphthalene and 1,5-dihydroxynaphthalene. These may be used alone or in combination of two or more.

The aldehyde compound may be, for example, formaldehyde, paraformaldehyde, acetaldehyde, propylaldehyde, benzaldehyde, phenylaldehyde,? - and? -Phenylpropylaldehyde, o-, m- and p-hydroxybenzaldehyde, glutaraldehyde , Glyoxal, o-, and p-methylbenzaldehyde. These may be used alone or in combination of two or more.

An acid catalyst may be used to promote the addition-condensation reaction. Examples of the acid catalyst include organic acids such as oxalic acid, formic acid, trichloroacetic acid, and p-toluenesulfonic acid; Inorganic acids such as hydrochloric acid, sulfuric acid, perchloric acid, phosphoric acid and the like; And acid metal salts such as zinc acetate and magnesium acetate. These may be used alone or in combination of two or more.

The weight average molecular weight (Mw, for example, in terms of polystyrene through GPC) of the alkali-soluble resin may be, for example, about 2,000 to 50,000. Within the above range, appropriate developability and solubility can be realized without impairing the adhesion and mechanical properties of the insulating film or the insulating pattern.

According to exemplary embodiments, the alkali-soluble resin in the total weight of the composition may be included in an amount of about 1 to 30 wt%, preferably 5 to 20 wt%. When the content of the alkali-soluble resin is less than about 1 wt%, a substantial coating film or pattern may not be formed. When the content of the alkali-soluble resin is more than about 30% by weight, the coating property of the composition is lowered, and film uniformity or pattern uniformity may be deteriorated.

Photosensitive agent

The photosensitizer may include, for example, a photoactive compound (PAC) that is reactive with light used in the exposure process. For example, the photosensitizer may be a photoactive compound, such as diazonaphthaquinone (DNQ) or naphthoquinone (NAD) having reactivity with respect to G-line ray, I- A compound of the naphtoquinone diazide (NQD) family.

For example, the photosensitizer may be bonded to hydroxyl groups (-OH groups) included in the alkali-soluble resin to form a bond. However, these bonds can be broken by irradiation of light such as G-line rays, I-line rays, and the like. Therefore, a difference in solubility in the developing solution in the exposed portion can be caused.

In some embodiments, the photosensitizer is selected from the group consisting of a phenolic compound having a hydroxyl group and a 1,2-naphthoquinonediazide-4-sulfonic acid, 1,2-naphthoquinonediazide- -Benzoquinone diazide-4-sulfonic acid, and the like, as well as a reaction product (for example, an esterified product) of a diazide compound.

The ester compound can be obtained by reacting the phenolic compound having a hydroxyl group with an o-quinonediazide sulfonyl halide in the presence of a triethylamine base in a solvent. Thereafter, the desired quinonediazide sulfonic acid ester can be isolated through post-treatment. The post-treatment may include a known process such as extraction, distillation, phase separation and the like.

According to exemplary embodiments, the photoresist in the total weight of the composition may be included in an amount of about 1 to 15 wt%, preferably 5 to 10 wt%. Within the above range, improved developability and sensitivity can be realized without impairing the film characteristics and reliability through the alkali-soluble resin.

Development enhancer

The photosensitive resin composition according to the exemplary embodiments may include a dioxane-based compound as a development promoter. In some embodiments, the development enhancer may include 1,4-dioxane represented by the following formula (1).

[Chemical Formula 1]

In the case of the above 1,4-dioxane, it has a chemically unstable cyclic epoxy-like structure and can be decomposed by the exposure process, for example, to generate hydroxylation. Therefore, the solubility in the exposed portion can be further increased. Therefore, fine patterning can be realized by increasing the resolution in the developing process.

In addition, the development enhancer may be combined with the photosensitizer described above to further increase the sensitivity in the exposure process.

According to exemplary embodiments, the content of the development enhancer may range from about 0.001 ppb to 1% by weight of the total composition. When the content of the development enhancer is less than about 0.001 ppb, the above-described solubility and sensitivity improvement effect is hardly realized. If the content of the development enhancer is more than about 1% by weight, complex formation with other components in the composition may result, and the solubility in the developer may be reduced.

menstruum

The photosensitive composition may use, as a solvent, an organic solvent having a sufficient solubility in the above-described alkali-soluble resin.

For example, ethers, acetates, esters, ketones, amides, and lactones may be used. These solvents may be used alone or in combination of two or more.

Examples of the ether solvents include ethylene glycol monoalkyl ethers, ethylene glycol dialkyl ethers, propylene glycol monoalkyl ethers, propylene glycol dialkyl ethers, diethylene glycol dialkyl ethers, dipropylene glycol monoalkyl ethers, dipropylene glycol dialkyl Ether, and the like.

Examples of the acetate solvents include 3-methoxybutyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoalkyl ether acetate, propylene glycol monoalkyl ether acetate, diethylene glycol monoalkyl ether acetate, dipropylene glycol monoalkyl ether acetate, Propylene glycol dialkyl acetate, and the like.

Examples of the ester solvent include ethyl hydroxyacetate, ethyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-3-methylbutyric acid, ethyl methoxyacetate, ethyl ethoxyacetate, methyl 3-methoxypropionate , 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, Methyl-3-methoxybutyl butyrate, methyl acetoacetate, ethyl acetoacetate, methyl pyruvate, ethyl pyruvate, and diethylene glycol methyl ethyl ester.

Examples of the ketone solvent include methyl ethyl ketone, methyl propyl ketone, methyl n-butyl ketone, methyl isobutyl ketone, 2-heptanone, 3-heptanone, 4-heptanone and cyclohexanone.

Examples of the amide solvent include N-methylformamide, N, N-dimethylformamide, N-methylacetamide, N, N-dimethylacetamide and N-methylpyrrolidone. An example of a lactone solvent is gamma -butyrolactone

The solvent may be included as a balance for the composition. The term " residual amount " as used in this application refers to a variable amount that varies with the inclusion of additional components.

In some embodiments, the solvent may be included in an amount of about 20 to 90 wt%, preferably about 50 to 85 wt%, of the total weight of the composition. Within this range, the coating properties and flatness of the composition are improved, and the uniform film pattern thickness can be obtained.

additive

The photosensitive resin composition may further contain an additive within a range that does not impair sensitivity, developability, and film reliability through the combination of the above-described alkali-soluble resin, photosensitive agent and development promoter. For example, the additive may include a colorant (e.g., a dye or a pigment), an adhesion promoter, a surfactant, a development rate enhancer, a light stabilizer, and the like.

For example, the adhesion promoter may include a coupling agent such as a silane coupling agent. Examples of the silane coupling agent include? -Aminopropyltrimethoxysilane,? -Aminopropyltriethoxysilane,? -Glycidoxypropyltrialkoxysilane,? -Glycidoxypropylalkyldialkoxysilane,? -Methacrylate (3,4-epoxycyclohexyl) ethyltrialkoxysilane,? - (3,4-epoxycyclohexyl) ethyltrialkoxysilane,? -Methacryloxypropyltrialkoxysilane,? -Mercaptopropyltrialkoxysilane, Vinyltrialkoxysilane, and the like.

The surfactant may include a fluorine surfactant, a nonionic surfactant, a cationic surfactant, an anionic surfactant, and a silicone surfactant, which are well known in the art. These may be used alone or in combination of two or more.

As the development rate improver, for example, a phenol compound having a low molecular weight can be used.

The light stabilizer can improve the light resistance of the photosensitive composition. The light stabilizer may include, for example, benzotriazole-based, triazine-based, benzophenone-based, hindered aminoether-based, hindered amine-based compounds, and the like.

The content of the above-mentioned additives may be appropriately changed in consideration of process conditions, and may be, for example, about 0.01 to 10% by weight, and preferably about 0.1 to 5% by weight, .

Pattern formation method

1 to 5 are schematic sectional views for explaining a pattern forming method according to exemplary embodiments.

Referring to FIG. 1, a film 110 to be etched may be formed on a substrate 100.

The substrate 100 may include a semiconductor substrate including silicon or germanium, glass, or a resin substrate. The etch target film 110 may be formed of an inorganic insulating material such as silicon oxide, silicon nitride, or the like; Organic insulating materials such as acrylic resin, imide resin and the like; A conductive material such as a metal or a transparent conductive oxide (e.g., ITO); Or a semiconductor material such as polysilicon, an oxide semiconductor, or the like.

In some embodiments, a buffer layer 120 may be further formed on the etch target film 110. For example, the buffer layer 120 may comprise a carbon-based or silicon-based spin-on hard mask (SOH) material and may be provided as a bottom anti-reflective layer (BARC).

Referring to FIG. 2, the photosensitive film 130 may be formed on the buffer layer 120 or the etching target film 110 using the photosensitive resin composition according to the exemplary embodiments. For example, the photosensitive resin composition may be applied by spin coating, slit coating, roll coating or the like, followed by drying and / or soft baking. For example, the soft bake process may be performed at a temperature range of about 60 to 150 &lt; 0 &gt; C.

Referring to FIG. 3, the exposure process may be performed on the photosensitive film 130 to form the exposed portion 130a and the non-exposed portion 130b.

For example, an exposure mask including a light shielding portion and a transmissive portion may be disposed on the photosensitive film 130, and ultraviolet light may be irradiated through the transmissive portion of the exposure mask.

Accordingly, the photosensitive film 130 can be divided into the exposure unit 130a and the non-exposure unit 130b. In the exposed portion 130a, the binding of the alkali-soluble resin may be broken or modified by the action of the photosensitizer of the photosensitive resin composition described above to increase the solubility in an alkali developing solution.

Further, the difference in solubility is further increased by the development enhancer of the dioxane series, and the exposure sensitivity can also be enhanced.

Referring to FIG. 4, the exposure unit 130a can be removed through a developing process using an alkaline developer. The insulating pattern 140 can be substantially formed by the remaining unexposed portions 130b. The insulating pattern 140 may be provided as a photoresist pattern.

The alkali developer may include an alkali hydroxide, ammonium hydroxide, tetramethylammonium hydroxide (TMAH), (2-hydroxyethyl) trimethylammonium hydroxide (or choline), and the like.

As described above, since the solubility of the exposed portion 130a and the non-exposed portion 130b is increased by the action of the development enhancer including the dioxane-based compound, the exposed portion 130a ) Can be selectively removed.

In some embodiments, the insulating pattern 140 may be formed through a hard baking process after the exposure and development processes. The hard baking process may be performed at a temperature of about 150 to 350 &lt; 0 &gt; C.

Referring to FIG. 5, the buffer layer pattern 125 may be formed by etching the buffer layer 120 using the insulating pattern 140 as a mask. Thereafter, the target pattern 115 may be formed by etching the etching target film 110 using the buffer layer pattern 125 as a mask.

The etch process may include an appropriate dry etch and / or wet etch depending on the material contained in the etch target layer 110.

After the etching process, the insulation pattern 140 may be removed through a strip process. The buffer layer pattern 125 may be removed through an ashing process.

1 to 5, an insulating film or an insulating pattern formed from the photosensitive composition according to the exemplary embodiments is used as an etching mask, and is shown to be removed thereafter. However, the insulating film or the insulating pattern may remain in the display device or the semiconductor device and may be included as an insulating structure.

Hereinafter, exemplary embodiments of the present invention will be described in order to facilitate understanding of the present invention. However, the present invention is not limited to the following claims, It will be apparent to those skilled in the art that various changes and modifications can be made in the embodiment within the scope of the category and the scope of the invention, and such variations and modifications are within the scope of the appended claims.

Examples and Comparative Examples

The photosensitive resin compositions according to Examples and Comparative Examples were prepared with the components and the contents (% by weight) shown in Tables 1 and 2 below.

Category (% by weight) Example Comparative Example One 2 3 4 5 6 7 8 Alkali-soluble resin
(A) A-1 11.04 11.04 11.04 11.04 11.04 11.04 11.04 11.04 11.04 A-2 7.36 7.36 7.36 7.36 7.36 7.36 7.36 7.36 7.36 Photosensitive agent
(B) 5.3 5.3 5.3 5.3 5.3 5.3 5.3 5.3 5.3 Development enhancer
(C) 0.000053 0.00053 0.00106 0.0053 0.053 0.53 1.0 1.5 - The solvent (D) Balance Balance Balance Balance Balance Balance Balance Balance Balance

The specific ingredients or compounds listed in Table 1 are as follows.

A-1: Cresol novolak resin (weight average molecular weight: 7.000) prepared by adding formaldehyde to a mixture of 36 mol% of m-cresol and 64 mol% of p-cresol in the presence of an oxalic acid catalyst,

A-2: Cresol novolak resin (weight average molecular weight: 8,000) obtained by condensation reaction of a mixture of 57 mol% of m-cresol and 43 mol% of p-cresol by adding formaldehyde in the presence of an oxalic acid catalyst,

B: 2.3 moles of ester of naphthoquinone-1,2-diazide-5-sulfonyl chloride, 1 mole of 2,3,4,4'-tetrahydroxybenzophenone

C: 1,4-dioxane

D: 3-methoxybutylacetate

Experimental Example

The photosensitive resin compositions of Examples and Comparative Examples were filtered with a fluororesin filter to obtain a resist solution. The resist solutions were spin-coated on copper sputtered glass wafers and pre-baked at 110 캜 for 60 seconds directly on a hot-plate to form a resist film having a thickness of 1.50 탆. The resist film was subjected to exposure treatment in the form of a line-and-space pattern using an I-line stepper ("NSR-2005 i9C" manufactured by Nikon Co., Ltd., NA = 0.57, Respectively. Thereafter, the wafer was baked after a post-exposure baking treatment at 110 ° C for 60 seconds on a hot plate, and then subjected to a puddle development for 60 seconds using a 2.38% tetramethylammonium hydroxide aqueous solution. The effective sensitivity and resolution of the exposure and development processes were evaluated as follows.

(1) Effective sensitivity

The amount of exposure at which the ratio of line to space was 1: 1 on the basis of the line-and-space pattern formed in the photosensitive resin composition rotor of the examples and comparative examples was confirmed and evaluated as follows.

<Evaluation Criteria>

◎: 10 to 100 mJ or less

○: more than 100 mJ and less than 200 mJ

?: More than 200 mJ and less than 300 mJ

X: more than 300 mJ

(2) Resolution

When the same exposure amount (100 mJ) was applied, the width of the pattern in which the ratio of the lines and spaces in the line-and-space pattern deviated from 0.95 to 1.05: 1.05 to 0.95 (reference ratio) was confirmed and evaluated as follows.

<Evaluation Criteria>

◎: Patterns with a width of 0.6um or more satisfy the reference ratio.

○: Patterns with a pattern width of 0.8 μm or more satisfy the reference ratio.

Δ: Patterns with a pattern width of 1.0 μm or more satisfy the reference ratio.

X: Pattern whose pattern width exceeds 1.0um does not satisfy the reference ratio.

The evaluation results are shown in Table 2 below.

Example Comparative Example One 2 3 4 5 6 7 8 Effective sensitivity ○ ◎ ◎ ◎ ◎ ○ ○ △ X resolution ○ ○ ◎ ○ ○ ○ ○ △ △

Referring to Table 2, for the examples in which 1,4-dioxane was added as a development enhancer, overall sensitivity and resolution were improved.

100: substrate 110: etching target film
120: buffer layer 130: photosensitive film
130a: Exposure section 130b: Non-
140: Insulation pattern

Claims (9)

Alkali-soluble resins;
Photosensitizer;
A development enhancer including 1,4-dioxane; And
A photosensitive resin composition comprising a solvent.
delete The photosensitive resin composition according to claim 1, wherein the content of the development enhancer is 0.001 ppb to 1% by weight based on the total weight of the composition.
The photosensitive resin composition according to claim 1, wherein the photosensitizer comprises a compound of diazonaphthaquinone (DNQ) or naphtoquinone diazide (NQD).
The photosensitive resin composition according to claim 1, wherein the alkali-soluble resin comprises a phenolic novolak resin or a cresol novolak resin.
Applying a photosensitive resin composition comprising an alkali-soluble resin, a photosensitizer, a development promoter including 1,4-dioxane, and a solvent on a substrate to form a photosensitive film;
Exposing the photosensitive film to form an exposed portion and an unexposed portion; And
And removing the exposed portion through a developing process to form an insulating pattern.
The method of claim 6,
Forming a film to be etched on the substrate before forming the photosensitive film; And
And etching the etching target film using the insulating pattern as an etching mask.
8. The method of claim 7, further comprising forming a buffer layer on the etch target film.
delete

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