KR101861310B1 - Cleaning composition for photolithography - Google Patents

Abstract

상기 화학식 1에서, R은 각각 독립적으로 수소 원자(H), 알콜기(-OH), 메틸기(-CH₃), 술폰산기(-SO₃H) 또는 아민기(-NH₂)이고, n은 1 내지 10의 정수이다.Disclosed is a cleaning liquid composition for photolithography capable of preventing numerical increase in pattern collapse and line width roughness (LWR), which occurs upon forming a photoresist pattern, and hardening a pattern surface to increase etching resistance. The cleaning liquid composition comprises an acidic monomolecular compound represented by the following formula (1): And a solvent.
[Chemical Formula 1]

In the above formula (1), each R is independently a hydrogen atom (H), an alcohol group (-OH), a methyl group (-CH ₃ ), a sulfonic acid group (-SO ₃ H) or an amine group (-NH ₂ ) And is an integer of 1 to 10.

Description

Cleaning composition for photolithography < RTI ID = 0.0 >

The present invention relates to a cleaning liquid composition, and more particularly, to a cleaning liquid composition capable of preventing a numerical increase in pattern collapse and line width roughness (LWR) occurring during photoresist pattern formation and hardening a pattern surface through a heating process, To a cleaning liquid composition for photolithography.

With the miniaturization and integration of semiconductor devices, resist materials used for manufacturing semiconductor devices have also been improved to cope with such miniaturization and integration. However, as miniaturization and integration of a semiconductor device progresses, various problems arise due to the implementation of fine patterns. For example, a decrease in the yield of a semiconductor device due to defects such as a defect in a resist pattern, an increase in numerical value of a line width roughness (LWR), and a pattern collapse can be cited.

Extreme ultraviolet lithography (EUVL) technology with a wavelength of 13.4 nm is used to produce a semiconductor device with a pattern resolution of 30 nm or less. In order to use the above technology, problems due to the aforementioned defects . Numerical increases in resist scum, line width roughness (LWR), pattern collapsing and the like are mostly caused by degradation of the photoresist composition, but the defects can be overcome by a cleaning technique. For example, in general, cleaning is carried out using pure water (cleaning liquid) in the course of the process. However, by adding a surfactant to the cleaning liquid to reduce the surface tension of the cleaning liquid, it is possible to prevent pattern collapse In some cases, partially insoluble insoluble polymers originating from the resist pattern of the surfactant hydrophilic group are removed together, resulting in a numerical increase (suppression) of the line width roughness (LWR). However, since the cleaning method causes a rounding process on the upper portion of the pattern (a rounded portion becomes rounded), it is impossible to obtain a pattern shape to be obtained. Due to the deformation of the pattern shape, Resistance is lowered, and other problems may arise.

Accordingly, it is an object of the present invention to provide a cleaning liquid composition for photolithography which can prevent a numerical increase in pattern collapse and line width roughness (LWR) of a photoresist pattern and harden a pattern surface to increase etching resistance.

In order to achieve the above object, the present invention provides an acidic monomolecular compound represented by the following formula (1): And a cleaning solvent composition for photolithography comprising a solvent.

[Chemical Formula 1]

In the above formula (1), each R is independently a hydrogen atom (H), an alcohol group (-OH), a methyl group (-CH ₃ ), a sulfonic acid group (-SO ₃ H) or an amine group (-NH ₂ ) Lt; / RTI >

The present invention also provides a method of manufacturing a semiconductor device, comprising: forming a photoresist film on a semiconductor substrate on which an etching layer is formed; Exposing and developing the photoresist film to form a photoresist pattern; Cleaning the photoresist pattern with the cleaning liquid composition for photolithography; And drying the washed photoresist pattern and heating (hard baking) the resultant at 110 to 200 ° C to cure the surface of the photoresist.

The cleaning liquid composition for photolithography according to the present invention comprises an acidic monomolecular compound and prevents the increase in the pattern collapse and line width roughness (LWR) of the photoresist pattern through cleaning and heating, The etching resistance can be increased.

Hereinafter, the present invention will be described in detail.

The cleaning liquid composition for photolithography according to the present invention comprises an acidic monomolecular compound represented by the following general formula (1), and a solvent.

In the above formula (1), each R is independently a hydrogen atom (H), an alcohol group (-OH), a methyl group (-CH ₃ ), a sulfonic acid group (-SO ₃ H) or an amine group (-NH ₂ ) And is an integer of 1 to 10. That is, when n is 2 or more, R of each n repeat unit may be the same or independent.

The acidic monomolecular compound used in the present invention is capable of curing a photoresist pattern surface by crosslinking reaction with a photosensitive polymer on the surface of a photoresist pattern (see Chemical Formula 2) upon heating (hard bake). The content of the acidic monomolecular compound is 0.001 to 5% by weight, preferably 0.005 to 1% by weight, more preferably 0.01 to 0.5% by weight, and most preferably 0.01 to 0.1% by weight, based on the entire photolithography cleaning liquid composition. Weight%. If the content of the acidic monomolecular compound is less than 0.001% by weight, the pattern surface may not be cured even when heated. If the content exceeds 5% by weight, the photoresist pattern may be damaged due to an increase in acidity.

(2)

In Formula 2, R and n are the same as defined in Formula 1, and A and B represent a functional group contained in a conventional photosensitive polymer.

Representative examples of the acidic monomolecular compound represented by the formula (1) include acidic monomolecular compounds represented by the following formulas (1a) to (1l).

[Formula 1a]

[Chemical Formula 1b]

[Chemical Formula 1c]

≪ RTI ID = 0.0 &

[Formula 1e]

(1f)

[Formula 1g]

[Chemical Formula 1h]

[Formula 1i]

[Chemical Formula 1j]

[Chemical Formula 1k]

≪ EMI ID =

The solvent used in the present invention may be water (pure water) for cleaning the photoresist pattern. If necessary, a mixed solvent in which water and a water-soluble organic solvent are mixed may be used. The water-soluble organic solvent may be a monovalent or polyhydric alcohol-based organic solvent. Examples of the monohydric alcohol include methanol, ethanol, propanol, isopropyl alcohol (IPA) and the like. And examples of the polyhydric alcohol include ethylene glycol, propylene glycol, diethylene glycol, glycerin, alkyl etherified products thereof, and esterified products thereof. The content of the solvent is the same as that of the cleaning solvent composition for photolithography except for the acidic monomolecular compound. When the mixed solvent is used as the solvent, the content of the water-soluble organic solvent is preferably 0.01 - 50% by weight, preferably 0.1 to 20% by weight. If the content of the water-soluble organic solvent exceeds 50 wt% with respect to the total solvent, the photoresist pattern may dissolve in the solvent to cause a pattern distortion phenomenon.

The cleaning liquid composition for photolithography according to the present invention may further contain an additive such as a surfactant if necessary. The surfactant is used for lowering the surface tension of the cleaning liquid composition, for example, by suppressing the pattern collapse by lowering the stress between the patterns generated when the cleaning liquid composition is spin-dried. As the surfactant, a conventional water-soluble surfactant can be used. For example, a water-soluble anionic surfactant, a water-soluble nonionic surfactant, a water-soluble cationic surfactant and a water-soluble amphoteric surfactant, Can be mixed and used. Specific examples of the water-soluble anionic surfactant include triethanolamine laurylsulfate, ammonium laurylsulfate, triethanolamine polyoxyethylene alkyl ether sulfates, and the like. The water-soluble nonionic surfactant Specific examples of the active agent include polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene higher alcohol ether, polyoxyethylene octylphenyl ether, polyoxyethylene Polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, Stearate, polyoxyethylene sor Polyoxyethylene sorbitan trioleate, tetraoleic acid polyoxyethylene sorbitol, polyethylene glycol monolaurate, polyethylene glycol monostearate, polyethylene glycol distearate, polyethylene glycol monooleate, polyoxyethylene alkyl Amine, polyoxyethylene hardened castor oil, alkanolamide, and the like. Specific examples of the water-soluble cationic surfactant include coconut amine acetate, stearyl amine acetate, etc. Specific examples of the water-soluble amphoteric surfactant include lauryl betaine, stearyl betaine, lauryl dimethyl amine oxide (RDMAO), 2-alkyl-N-carboxymethyl- N-hydroxyethylimidazolinium betaine, and the like. S-465 and S-485W of Air-product, etc., 25R2 and L-62 of Rhodia, etc., and 212M of NEOS, such as NOVEC 4200 and FC-4430 of 3M, FSN and FSO of Dupont Co., , 215M and the like, F-410 and F-477 of DIC Co., and NCW1001 and NCW1002 of WAKO can be used singly or in combination.

When the surfactant is used, the content of the surfactant is 0.001 to 5 parts by weight, preferably 0.001 to 1 part by weight, more preferably 0.01 to 0.5 parts by weight, relative to 100 parts by weight of the cleaning liquid composition for photolithography as a whole , And most preferably 0.05 to 0.1 part by weight. If the amount of the surfactant is less than 0.001 part by weight based on 100 parts by weight of the cleaning liquid composition for photolithography as a whole, there is a fear that pattern collapse occurs. If the amount exceeds 5 parts by weight, there is a fear of acting as an impurity.

The cleaning liquid composition according to the present invention can be used in a cleaning process of a conventional photolithography process, and the surface of the photoresist pattern formed through the heating process after cleaning can be cured. For example, a method of forming a photoresist pattern according to the present invention includes the steps of: (a) forming a photoresist film on a semiconductor substrate having a pattern layer formed thereon, (b) exposing and developing the photoresist film to form a photoresist pattern (C) cleaning the photoresist pattern with the cleaning liquid composition for photolithography; and (d) drying the washed photoresist pattern by spin-out (spin-dry) , And heating (hard bake) to 110 to 200 캜, preferably 130 to 150 캜, to cure the photoresist surface.

In the photoresist pattern forming method, the photoresist pattern may be washed by the first cleaning using pure water, followed by the second cleaning using the cleaning composition of the present invention. In the heating (hard bake) process, If it is less than 110 deg. C, there is a fear that the pattern is not cured. If the heating temperature exceeds 200 deg. C, there is a fear that the pattern collapses due to thermal decomposition of the resist itself.

The cleaning liquid composition of the present invention can prevent scum, pattern collapse, and the like caused by fine pattern formation and improve pattern roughness. Therefore, it is possible to form fine patterns using extreme ultraviolet lithography (EUVL) And the etching resistance can be improved through pattern surface hardening.

Hereinafter, the present invention will be described in more detail with reference to specific examples. The following examples illustrate the present invention and are not intended to limit the scope of the present invention.

[Examples 1 to 42 and Comparative Examples 1 to 4] Preparation and evaluation of a cleaning liquid composition for photolithography

A. Preparation of Cleaning Solution Composition for Photolithography

The acidic monomolecular compound, the solvent and the surfactant were mixed for 4 hours according to the compositions of Tables 1 to 4 below to completely dissolve the acidic monomolecular compound and the surfactant in the solvent, To prepare a cleaning liquid composition for photolithography.

B. Formation of Photoresist Pattern and Evaluation of Cleaning Solution Composition

(a) For the formation of a photoresist pattern and the evaluation of a cleaning liquid composition, a photosensitive polymer was synthesized as follows. 117.2 g (0.5 mol) of 2-methyl-2-adamantyl methacrylate, 3-hydroxy-1-adamantyl methacrylate (0.1 mol) of 2-oxotetrahydrofuran-3-yl methacrylate, 68.0 g (0.4 mol) of 2-oxotetrahydrofuran-3-yl methacrylate, and azobis (isobutyronitrile) Was dissolved in 125 g of anhydrous tetrahydrofuran (THF), the gas was removed using an ampoule by the freezing method, and the reaction product was polymerized at 68 DEG C for 24 hours. After the polymerization is completed, the reaction solution is slowly dropped to an excess amount of diethyl ether to precipitate the precipitate. The precipitate is dissolved again in tetrahydrofuran (THF) and then re-precipitated in diethyl ether to prepare a photopolymerized photosensitive polymer (terpolymer) (Yield: 53%, weight average molecular weight (Mw): 8,500, polydispersity index (PDI): 1.8).

(b) Next, 10 parts by weight of diphenyl para-toluenesulfonylnonium plate (TPS-NF), a base stabilizer (manufactured by Nippon Denshoku Kogyo Co., Ltd.) as a photo- 20 parts by weight of triethanolamine was added to propylene glycol monomethyl ether acetate (PGMEA) in 100 parts by weight of the photoacid generator, and the mixture was stirred for 12 hours or longer to completely dissolve the nylon material filter. And then sequentially filtered through a polytetrafluoroethylene (PTFE) material filter to prepare a photoresist composition.

(c) The photoresist composition prepared in (b) above was spin-coated on the top of the etching layer of a silicon wafer to form a photoresist thin film (film), followed by heating (prebaking) (I) Exposure with an ArF ASML 1200B instrument having a numerical aperture (NA) of 0.85 (Examples 1 to 37, Comparative Examples 1 and 2), (ii) Extreme ultraviolet lithography (EUVL) Exposed to an exposure machine (Examples 38 to 42 and Comparative Examples 3 to 4), and then heated at 125 占 폚 for 60 seconds (post exposure bake: PEB). The wafer thus baked (heated) was developed in an aqueous solution of 2.38% by weight of tetramethylammonium hydroxide (TMAH) for 30 seconds to give a film having a film thickness of 140 nm and a line width of 70 nm in a 1: 1 line and a space (L / S line (Comparative Examples 1 to 2) or (ii) 1: 1 line and space (L / S: line / space) patterns having a film thickness of 60 nm and a line width of 30 nm (Comparative Examples 3 to 4) were formed. The thickness of the photoresist film was measured using Opti-2600, a measuring instrument of KLA, and the pattern of the formed pattern was measured using an electron microscope (CD-SEM, device name: S9220, manufacturer: Hitachi) (Unit: nm) and line width roughness (LWR, unit: nm) were measured. Here, the criterion of the pattern collapse is calculated by measuring a point at which the trailing edge pattern of the L / S pattern collapses. In addition, since the resist scum on the bottom rather than the line width also affects the line width roughness (LWR) value, the improvement (reduction) of the line width roughness (LWR) means that the resist scum is also improved do. The results are shown in Tables 1 and 4 below.

(d) developing the photoresist pattern in the same manner as in (c) above, then rinsing with pure water for 30 seconds, sprinkling the cleaning liquid composition prepared in the step A on the surface of the developed photoresist pattern, (I) a 1: 1 line and a space / line (space / line) pattern having a film thickness of 140 nm and a line width of 70 nm (Example 1 To (37) or (ii) a 1: 1 line and a space (L / S: line / space) pattern (Examples 38 to 42) having a film thickness of 60 nm and a line width of 30 nm. The pattern collapse line width (unit: nm) and the line width roughness (LWR, unit: nm) of the photoresist pattern formed in the same manner as in (c) above were evaluated and shown in Tables 1 to 4, , And relative etch rates were measured and are shown in Table 1 below. Here, the relative etch rate is a value converted based on the comparative example 1, the etching rate measurement conditions BT (breakthrough): a _{Cl 2 / HBr / O 2 (} 30sec): CF 4 (10sec), ME (main etch) .

Acid monomolecular
compound Surfactants Heating temperature Solvent ratio Pattern collapse
Line width Line width roughness (nm) Relative etching rate (Pure water: alcohol) The Content (ppm) designation Content (ppm) Alcohol ratio Comparative Example 1 - - - - - - 100: 0 74 nm 5.4 One Comparative Example 2 - - - - 150 ℃ - 100: 0 flow - - Example 1 1a 1000 S-465 1000 150 ℃ - 100: 0 60 nm 3.2 0.91 Example 2 1b 1000 S-465 1000 150 ℃ - 100: 0 61 nm 4.0 0.91 Example 3 1c 1000 S-465 1000 150 ℃ - 100: 0 62 nm 4.0 0.82 Example 4 1d 1000 S-465 1000 150 ℃ - 100: 0 65 nm 3.9 0.91 Example 5 1e 1000 S-465 1000 150 ℃ - 100: 0 62 nm 4.1 0.90 Example 6 1f 1000 S-465 1000 150 ℃ - 100: 0 59 nm 4.1 0.92 Example 7 1g 1000 S-465 1000 150 ℃ - 100: 0 63 nm 3.5 0.90 Example 8 1h 1000 S-465 1000 150 ℃ - 100: 0 62 nm 3.4 0.90 Example 9 1i 1000 S-465 1000 150 ℃ - 100: 0 68 nm 4.2 0.90 Example 10 1j 1000 S-465 1000 150 ℃ - 100: 0 65 nm 4.1 0.91 Example 11 1k 1000 S-465 1000 150 ℃ - 100: 0 60 nm 4.0 0.89 Example 12 1l 1000 S-465 1000 150 ℃ - 100: 0 59 nm 3.8 0.88

Acid monomolecular
compound Surfactants Heating temperature (℃) Solvent ratio pattern
Declination line width Line width roughness (nm) (Pure water: alcohol) The Content (ppm) designation Content (ppm) Alcohol ratio Example 13 1c 500 S-465 1000 150 ℃ - 100: 0 63 nm 4.2 Example 14 1c 5000 S-465 1000 150 ℃ - 100: 0 62 nm 3.9 Example 15 1c 1000 S-465 1000 110 ° C - 100: 0 62 nm 4.0 Example 16 1c 1000 S-465 1000 120 DEG C - 100: 0 62 nm 4.1 Example 17 1c 1000 S-465 1000 130 ℃ - 100: 0 62 nm 4.0 Example 18 1c 1000 S-465 1000 140 ° C - 100: 0 62 nm 4.0 Example 19 1c 1000 S-465 1000 160 ° C - 100: 0 62 nm 3.8 Example 20 1c 1000 FSN 1000 150 ℃ - 100: 0 63 nm 4.5 Example 21 1c 1000 FSO 1000 150 ℃ - 100: 0 64 nm 4.6 Example 22 1c 1000 25R2 1000 150 ℃ - 100: 0 64 nm 4.2 Example 23 1c 1000 L-62 1000 150 ℃ - 100: 0 63 nm 4.1 Example 24 1c 1000 212M 1000 150 ℃ - 100: 0 63 nm 4.6 Example 25 1c 1000 Novec 4200 1000 150 ℃ - 100: 0 62 nm 4.2

Acid monomolecular
compound Surfactants Heating temperature (℃) Solvent ratio pattern
Declination line width Line width roughness (nm) (Pure water: alcohol) The Content (ppm) designation Content (ppm) Alcohol ratio Example 26 1c 1000 FC-4430 1000 150 ℃ - 100: 0 63 nm 4.3 Example 27 1c 1000 F-410 1000 150 ℃ - 100: 0 58 nm 3.9 Example 28 1c 1000 F-477 1000 150 ℃ - 100: 0 58 nm 4.2 Example 29 1c 1000 NCW1001 1000 150 ℃ - 100: 0 58 nm 4.8 Example 30 1c 1000 NCW1002 1000 150 ℃ - 100: 0 59 nm 5.0 Example 31 1c 1000 RDMAO 1000 150 ℃ - 100: 0 59 nm 3.5 Example 32 1c 1000 S-465 1000 150 ℃ Methanol 90:10 58 nm 3.7 Example 33 1c 1000 S-465 1000 150 ℃ Methanol 70:30 58 nm 3.5 Example 34 1c 1000 S-465 1000 150 ℃ ethanol 90:10 57 nm 3.6 Example 35 1c 1000 S-465 1000 150 ℃ ethanol 70:30 57 nm 3.4 Example 36 1c 1000 S-465 1000 150 ℃ IPA 90:10 58 nm 3.9 Example 37 1c 1000 S-465 1000 150 ℃ IPA 70:30 59 nm 3.5

Acidic starch
compound Surfactants Heating temperature (℃) Solvent ratio pattern
Declination line width Line width roughness (nm) (Pure water: alcohol) The Content (ppm) designation Content (ppm) Alcohol ratio Comparative Example 3 - - - - - - 100: 0 24 nm 5.4 Comparative Example 4 - - - - 150 ℃ - 100: 0 flow - Example 38 1b 1000 S-465 1000 150 ℃ - 100: 0 20 nm 3.5 Example 39 1c 1000 S-465 1000 150 ℃ - 100: 0 20 nm 3.4 Example 40 1d 1000 S-465 1000 150 ℃ - 100: 0 21 nm 3.5 Example 41 1f 1000 S-465 1000 150 ℃ - 100: 0 20 nm 3.9 Example 42 1k 1000 S-465 1000 150 ℃ - 100: 0 21 nm 4.0

From the above results, it can be seen that the photoresist pattern is broken due to the high heating temperature (pattern flow) when the hard bake is conducted at 150 ° C. (Comparative Examples 2 and 4) without using the cleaning liquid composition according to the present invention , It can be seen that when the cleaning liquid composition of the present invention is used, there is no pattern damage due to pattern surface hardening (increase in etching resistance), and effectively preventing the increase of pattern collapse and line width roughness (LWR).

Claims (5)

An acidic monomolecular compound represented by the following formula (1); And
A solvent, and crosslinking with the photosensitive polymer on the surface of the photoresist.
[Chemical Formula 1]

In the above formula (1), each R is independently a hydrogen atom (H), an alcohol group (-OH), a methyl group (-CH ₃ ), a sulfonic acid group (-SO ₃ H) or an amine group (-NH ₂ ) Lt; / RTI > The composition for cleaning and coating a photoresist pattern according to claim 1, wherein the acidic monomolecular compound represented by Formula 1 is selected from the group consisting of acidic monomolecular compounds represented by the following Chemical Formulas 1a to 1l.
[Formula 1a]

[Chemical Formula 1b]

[Chemical Formula 1c]

≪ RTI ID = 0.0 &

[Formula 1e]

(1f)

[Formula 1g]

[Chemical Formula 1h]

[Formula 1i]

[Chemical Formula 1j]

[Chemical Formula 1k]

≪ EMI ID =

The cleaning liquid composition for photolithography according to claim 1, wherein the content of the acidic monomolecular compound is 0.001 to 5% by weight, and the balance is a solvent A composition for cleaning and coating photoresist patterns. The photoresist pattern cleaning and coating composition according to claim 1, further comprising 0.001 to 5 parts by weight of a surfactant based on 100 parts by weight of the cleaning liquid composition for the entire photolithography. Forming a photoresist film on the semiconductor substrate on which the etching layer is formed;
Exposing and developing the photoresist film to form a photoresist pattern;
Cleaning the photoresist pattern with a composition for cleaning and coating a photoresist pattern according to any one of claims 1 to 4; And
Drying the washed photoresist pattern, and heating (hard baking) the resultant at 110 to 200 캜 to cure the surface of the photoresist.