KR20120040985A - Photoresist composition - Google Patents

Abstract

PURPOSE: A photoresist composition, a flat panel display device using the same, a semiconductor device are provided to improve residual film rate and to prevent the reduction of sensitivity although h-line light source is used. CONSTITUTION: A photoresist composition includes 10-25 weight% of alkali soluble resin, 0.1-5 weight% of oxime urethane-based photobase generator, 1-10 weight% of photosensitive compound, and remaining amount of solvent. The oxime urethane-based photobase generator is selected from compounds displayed chemical formulas 1 to 4. The photosensitive compound is quinonediazide compound. The solvent is one or more selected from a group including glycol ether ester, glycol ether, ester, ketone, and cyclic ester.

Description

Photoresist composition {PHOTORESIST COMPOSITION}

The present invention relates to a photoresist composition.

In recent years, as the degree of integration of integrated circuits has increased, photolithography using excimer lasers, such as krypton fluoride (hereinafter referred to as KrF) and argon fluoride (hereinafter referred to as ArF), has become a major factor. In such photolithography, so-called chemically amplified resists using an acid catalyst and a chemical amplification effect are adopted. When a chemically amplified resist is used, the acid generated from the photoacid generator is diffused by heat treatment in the radiation irradiator, and the solubility in the alkaline developer of the irradiated portion is changed by a reaction using the diffused acid as a catalyst. A type pattern is obtained.

In addition, the main component of the composition of the photoresist was changed with the increase of the density. In general, novolak phenol and naphthodiazo-based components were the main components in g and i-line, and phenolic hydroxy and photoacid generator were the main components in KrF excimer laser. In the excimer laser of ArF, acrylate resin and photoacid generator are used as main components. This change is the polarity of the main component is gradually increased, the solubility is lowered without the use of an appropriate organic solvent, re-precipitated upon storage, causing particle defects, and also appear to be a process defect when the photoresist is applied.

It is an object of the present invention to provide a photoresist composition which is excellent in residual film ratio and does not degrade in sensitivity even when applied to an h-line light source.

It is also an object of the present invention to provide a photoresist composition capable of forming a pattern having excellent heat resistance, shape of the pattern and resolution.

It is also an object of the present invention to provide a positive photoresist composition capable of realizing high resolution with respect to an h-line light source in a process of forming a source / drain interconnect using a digital exposure machine.

The present invention (a) alkali soluble resin; (b) an oxime urethane-based photobase generator; (c) photosensitive compounds; And (d) provides a positive photoresist composition comprising a solvent.

The present invention provides a flat panel display device manufactured using the photoresist composition.

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

Even when an h-line light source is used to form a pattern using the positive photoresist composition of the present invention, the residual film ratio is excellent and the sensitivity is not lowered. Moreover, when a pattern is formed using the positive photoresist composition of this invention, heat resistance, the shape of a pattern, and the resolution become excellent. In addition, since the positive photoresist composition of the present invention is also suitable for digital exposure using only an h-line light source, the positive photoresist composition may be usefully used in a process of forming a source / drain wiring.

1 is a cross-sectional photograph of a pattern formed of the photoresist composition of Example 3.
2 is a cross-sectional photograph of a pattern formed of the photoresist composition of Comparative Example 2.

Hereinafter, the present invention will be described in detail.

The positive photoresist composition of the present invention comprises (a) an alkali soluble resin; (b) an oxime urethane-based photobase generator; (c) photosensitive compounds; And (d) a solvent.

(A) Alkali-soluble resin contained in the positive photoresist composition of this invention will not be specifically limited if it is used in the art, For example, the condensate obtained by addition-condensation reaction of a phenol compound and an aldehyde compound can be used.

The pulmonol compound is not particularly limited as long as it is used in the art, for example, phenol, o-cresol, m-cresol, p-cresol, 2,5-xylenol, 3,5-xyleneol, 3, 4-xyleneol, 2,3,5-trimethylphenol, 4-t-butylphenol, 2-t-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, 1,5-di Hydroxytaphthylene and the like, and these may be used in the form of one kind or a mixture of two or more kinds.

The aldehyde compound is not particularly limited as long as it is used in the art, for example, formaldehyde, paraformaldehyde, acetaldehyde, propylaldehyde, benzaldehyde, phenylaldehyde, α-phenylpropyl aldehyde, β-phenylpropyl aldehyde, o -Hydroxybenzaldehyde, m-hydroxybenzaldehyde, p-hydroxybenzaldehyde, glutaraldehyde, glyoxal, o-methylbenzaldehyde, p-methylbenzaldehyde and the like.

The addition-condensation reaction between the phenol compound and the aldehyde compound can be carried out by conventional methods in the presence of an acid catalyst. The reaction conditions may be changed depending on the condensate to be obtained, for example, the reaction temperature may be performed at 60 to 250 ° C. and the reaction time at 2 to 30 hours. The addition-condensation reaction can then be carried out in a suitable solvent or in bulk. In addition, the second alkali-soluble resin prepared by the addition-condensation reaction preferably has a weight average molecular weight of 3,000 to 8,000 in terms of polystyrene.

Here, the acid catalyst is not particularly limited as long as it is a material used in the art, and examples thereof 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; Divalent metal salts, such as zinc acetate and magnesium acetate, etc. are mentioned.

The alkali-soluble resin (a) is preferably 10 to 25% by weight, more preferably 10.5 to 20% by weight based on the total weight of the composition. If the above range is satisfied, there is an advantage that the resolution and the profile shape are excellent.

The (b) oxime urethane-based photobase generator included in the positive photoresist composition of the present invention improves the top profile of the pattern formed from the positive photoresist composition of the present invention, and reduces bottom tailing. Enable high resolution.

The (b) oxime urethane-based photobase generator is preferably selected from the compounds represented by the following formula (1) to (4).

<Formula 1>

<Formula 2>

<Formula 3>

<Formula 4>

Compounds represented by Formula 1 to Formula 4 may be prepared directly or purchased and used.

The (b) oxime urethane-based photobase generator is preferably contained in 0.1 to 5% by weight, more preferably in 0.2 to 2.5% by weight based on the total weight of the composition. If included below the above range, it is not possible to improve the top profile or reduce the bottom tailing. If it is included in excess of the above-described range, the upper part of the pattern is thickened, the pattern collapses or the residual film ratio rises rapidly, thereby causing problems in sensitivity and development.

The photosensitive compound (c) included in the photoresist composition of the present invention is not particularly limited as long as it is used in the art, and for example, naphthoquinone-1,2-diazide-5-sulfonyl chloride and naphthoquinone- 1,2-diazide-4-sulfonyl chloride and the like can be used. And the compound which has a functional group which can be condensed with these can also be used together. The compound having the condensable functional group is not particularly limited as long as it is used in the art, for example, phenol, paramethoxyphenol, hydroxyphenone, 2,3,4,4'-tetrahydroxybenzophenone, 2, 4-dihydroxybenzophenone, aniline, etc. can be used.

The photosensitive compound (c) is preferably contained in 1 to 10% by weight, more preferably 1.5 to 8% by weight based on the total weight of the composition. When included below the above-mentioned range, the developing residual film ratio falls, and a pattern of severe loss of the upper portion is made. If the above-mentioned range is exceeded, the sensitivity becomes low, a scum is generated in the lower part of the pattern, and only the upper part of the pattern becomes excessively large.

The (d) solvent included in the photoresist composition of the present invention dissolves the (a) alkali-soluble resin, (b) oxime-urethane-based photobase generator and (c) photosensitive compound, exhibits a suitable drying rate, and is uniform after solvent evaporation. If it provides a smooth and smooth film, it will not specifically limit. Examples of the (d) solvent include glycol ether esters such as ethylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate; Glycol ethers such as propylene glycol monomethyl ether; Esters such as ethyl lactate, butyl acetate, amyl acetate and ethyl pyruvate; Ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone; Alcohol, such as 3-methoxy- 1-butanol, etc. are mentioned.

The solvent (d) may be present in the solution state of the photoresist composition of the present invention, it is preferable that the remaining amount is included so that the total weight of the composition is 100% by weight.

Moreover, the photoresist composition of this invention can add additives, such as a coloring agent, dye, a plasticizer, a speed increasing agent, surfactant, as needed. By coating the photoresist composition containing such an additive on the substrate, it is possible to improve the performance according to the characteristics of the individual process.

Hereinafter, a pattern forming method using the photoresist composition of the present invention will be described.

First, the photoresist composition of this invention is apply | coated on a board | substrate, and a coating film is formed. The coating method may be performed by conventional methods such as dipping, spraying, rotating, and spin coating. The grill may be performed to evaporate the solvent without pyrolyzing the solid component of the photoresist composition, wherein the temperature may be, for example, 20 ° C to 100 ° C. Next, the board | substrate with which the precured coating film was formed is exposed. The substrate including the exposed coating film is sufficiently immersed in an alkaline developing aqueous solution, and then left until all or almost all of the coating film at the portion exposed to light or the non-exposed portion is dissolved. The alkaline developing aqueous solution is not particularly limited as long as it is used in the art, but an aqueous solution containing alkali hydroxide, ammonium hydroxide or tetramethylammonium hydroxide (TMAH) may be used. After the exposed or unexposed portions are dissolved and removed, the substrate on which the coating pattern is formed is taken out of the developer, and then a baking process is performed to enhance adhesion and chemical resistance of the coating. The baking process is preferably performed at a temperature below the softening point of the photoresist film, for example, may be performed at a temperature of about 100 to 150 ℃. Subsequently, the substrate on which the coating layer pattern is formed is etched by wet etching or dry etching using gas plasma. After the substrate is treated in this manner, the photoresist pattern is removed with an appropriate stripper to complete the pattern on the substrate.

In addition, a flat panel display device or a semiconductor device can be manufactured using the photoresist composition of the present invention.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following examples are intended to further illustrate the present invention, and the scope of the present invention is not limited by the following examples. The following examples can be appropriately modified and changed by those skilled in the art within the scope of the present invention.

Preparation Example 1 Preparation of Novolac Resin A-1

m-cresol and p-cresol were mixed in a weight ratio of 6: 4, formaldehyde was added to the mixture, and then condensed by a conventional method using an oxalic acid catalyst to obtain a cresol novolak resin. This resin was fractionated and the novolak resin having a weight average molecular weight of 15,000 was obtained by cutting off the polymer region and the low molecular region.

Preparation Example 2 Preparation of Novolac Resin A-2

m-cresol and p-cresol were mixed at a weight ratio of 5: 5, and formaldehyde was added thereto, followed by condensation by a conventional method using an oxalic acid catalyst to obtain a cresol novolak resin. This resin was subjected to fractionation treatment to cut off the polymer region and the low molecular region to obtain a novolak resin having a weight average molecular weight of 16,000.

Preparation Example 3 Preparation of Photobase Generator B-1

After dissolving 0.84 g of benzyl monoxime in 20 ml of acetonitrile, 0.1 ml of triethylamine was added and 0.46 ml of cyclohexyl isocyante was added and refluxed for 4 hours. . The solvent was removed and then recrystallized from ethyl acetate. The recrystallized compound was a compound represented by the formula (1).

Preparation Example 4 Preparation of Photobase Generator B-2

After dissolving 1.48 g of benzophenone oxime in 20 ml of acetonitrile, 0.1 ml of triethylamine was added and 0.09 ml of cyclohexyl isocyante was added and refluxed for 4 hours. . After removal of the solvent the resulting solid was recrystallized from ethyl acetate. The recrystallized compound was a compound represented by the formula (2).

Preparation Example 5 Preparation of Photobase Generator B-3

Dissolve 0.4 g of benzophenone oxime in 20 ml of chloroform, add 0.1 ml of triethylamine and add 0.17 ml of 1,6-hexamethylene diisocyanate. It was refluxed for 4 hours after the addition. After separation by silica gel column chromatography, the mixture was crystallized with a mixed solvent of acetone and water. The crystallized compound was a compound represented by Chemical Formula 3.

Examples 1-8 and Comparative Examples 1-7: Preparation of Photoresist Compositions

A photoresist composition was prepared by blending the composition as shown in Table 1. The prepared composition was filtered using a 0.2 μm filter.

Alkaline soluble resin
(weight%) Photobase Generator
(weight%) Photosensitive compound
(weight%) menstruum
(weight%) Example 1 A-1 / A-2 (4: 6) 12.33 B-1 0.5 C-1 2.65 D-1 / D-2 (8: 2) Balance Example 2 A-1 / A-2 (4: 6) 12.33 B-2 0.5 C-1 2.65 D-1 / D-2 (8: 2) Balance Example 3 A-1 / A-2 (4: 6) 12.33 B-3 0.5 C-1 2.65 D-1 / D-2 (8: 2) Balance Example 4 A-1 / A-2 (4: 6) 12.33 B-1 0.25 C-1 2.65 D-1 / D-2 (8: 2) Balance Example 5 A-1 / A-2 (4: 6) 12.33 B-1 0.75 C-1 2.65 D-1 / D-2 (8: 2) Balance Example 6 A-1 / A-2 (4: 6) 12.33 B-1 One C-1 2.65 D-1 / D-2 (8: 2) Balance Example 7 A-1 / A-2 (4: 6) 12.33 B-2 One C-1 2.65 D-1 / D-2 (8: 2) Balance Example 8 A-1 / A-2 (4: 6) 12.33 B-3 One C-1 2.65 D-1 / D-2 (8: 2) Balance Comparative Example 1 A-1 / A-2 (4: 6) 12.33 B-1 - C-1 2.65 D-1 / D-2 (8: 2) Balance Comparative Example 2 A-1 / A-2 (4: 6) 12.33 B-1 0.05 C-1 2.65 D-1 / D-2 (8: 2) Balance Comparative Example 3 A-1 / A-2 (4: 6) 12.33 B-1 5.05 C-1 2.65 D-1 / D-2 (8: 2) Balance Comparative Example 4 A-1 / A-2 (4: 6) 12.33 B-2 0.05 C-1 2.65 D-1 / D-2 (8: 2) Balance Comparative Example 5 A-1 / A-2 (4: 6) 12.33 B-2 5.05 C-1 2.65 D-1 / D-2 (8: 2) Balance Comparative Example 6 A-1 / A-2 (4: 6) 12.33 B-3 0.05 C-1 2.65 D-1 / D-2 (8: 2) Balance Comparative Example 7 A-1 / A-2 (4: 6) 12.33 B-3 5.05 C-1 2.65 D-1 / D-2 (8: 2) Balance

A-1: novolak resin prepared in Preparation Example 1 (weight ratio of m-cresol: p-cresol 6: 4)

A-2: novolak resin prepared in Preparation Example 2 (weight ratio of m-cresol: p-cresol 5: 5)

B-1: the compound prepared in Preparation Example 3

B-2: Compound Prepared in Preparation Example 4

B-3: Compound Prepared in Preparation Example 5

C-1: naphthoquinone diazide compound (ester compound of 2,3,4,4'-tetrahydroxybenzophenone and 1,2-naphthoquinone diazide-5-sulfonyl chloride)

D-1: propylene glycol monoether acetate

D-2: Propylene Glycol Monomethyl Ether

Test Example: Performance Test of Photoresist Composition

The photoresist solutions of Examples 1-8 and Comparative Examples 7-7 were spin-coated onto a silicon wafer treated with hexamethylenedisilazane (HMDS) and directly at 120 ° C. for 120 seconds on a hot-plate. Pre-baking treatment was performed to form a photoresist film having a thickness of 2.50 mu m. The wafer was exposed to a line-and-space pattern in steps of varying the exposure amount using a h-line filter on a Mask Aligner (MA-6, Karl Suss, roughness: 0.8), followed by 2.38% tetramethylammonium hydroxide. Puddle development was carried out for 70 seconds using aqueous aqueous solution (TMAH).

The patterns formed of the photoresist compositions of Example 3 and Comparative Example 2 were observed by scanning electron microscopy (FIGS. 1 and 2). The resolution, pattern shape, residual film ratio, heat resistance and the like were evaluated for each pattern by the following method. The results are shown in Table 2 below.

<Resolution>

When exposed with effective sensitivity (exposure amount when the cross section of the 3 占 퐉 line-and-space pattern is 1: 1), the minimum line width that separates the line-and-space pattern is shown.

Remnant Rate

Resist film thickness ratio before / after developing

[Residual film ratio = (film thickness after development ÷ film thickness before development) X 100]

<Pattern shape>

The top part of the pattern was observed by cross-sectional SEM measurement.

(Double-circle): Very good, (circle): Good, (triangle | delta): Normal, X: It evaluated as bad.

<Heat resistance>

After treatment at 150 ° C. for 150 seconds on a hot plate, the results were evaluated as follows by comparing with the profile of the pattern before treatment using a scanning electron microscope.

 ◎: unchanged, ○: slightly changed, △: normal level, X: bad

Effectiveness
(mJ) resolution
(Μm) Residual rate
(%) Pattern shape Heat resistance Example 1 80 3 97 ○ ○ Example 2 80 3 97 ○ ○ Example 3 80 2.5 97 ◎ ○ Example 4 80 3 97 ○ ○ Example 5 81 3 97 ◎ ○ Example 6 81 3 98 ◎ ○ Example 7 81 3 98 ◎ ○ Example 8 81 3 98 ◎ ○ Comparative Example 1 80 5 97 △ △ Comparative Example 2 81 5 98 △ △ Comparative Example 3 85 7 99 X ◎ Comparative Example 4 81 5 98 △ △ Comparative Example 5 85 7 99 X ◎ Comparative Example 6 81 5 98 △ △ Comparative Example 7 86 7 99 X ◎

Referring to Table 2, the pattern formed by using the photoresist composition of the present invention containing a photobase generator does not significantly reduce the residual film ratio and sensitivity, it is confirmed that the excellent in terms of heat resistance, shape and resolution of the pattern Can be.

1 is a cross-sectional photograph of a pattern formed of the photoresist composition of Example 3, and FIG. 2 is a cross-sectional photograph of a pattern formed of the photoresist composition of Comparative Example 2. FIG.

1 and 2, the pattern formed of the photoresist composition of Example 3 has a superior top profile, but the pattern formed of the photoresist composition of Comparative Example 2 does not have an excellent top profile of the pattern. have.

Claims (7)

(a) alkali soluble resins;
(b) an oxime urethane-based photobase generator;
(c) photosensitive compounds; And
(d) A photoresist composition comprising a solvent. The method according to claim 1,
Regarding the total weight of the composition,
10-25 wt% of the (a) alkali-soluble resin;
0.1 to 5% by weight of the (b) oxime urethane-based photobase generator;
1 to 10% by weight of the (c) photosensitive compound; And
(D) a photoresist composition comprising the remaining amount of the solvent. The method according to claim 1,
The (b) oxime urethane-based photobase generator is a photoresist composition, characterized in that selected from the compounds represented by the following formula (1) to (4):
<Formula 1>

<Formula 2>

<Formula 3>

<Formula 4>

The method according to claim 1,
(C) the photosensitive compound is a quinone diazide compound. The method according to claim 1,
The solvent (d) is a photoresist composition, characterized in that one or two or more selected from the group consisting of glycol ether esters, glycol ethers, esters, ketones and cyclic esters. A flat panel display manufactured using the photoresist composition of claim 1. A semiconductor device manufactured using the photoresist composition of claim 1.

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