KR20160136616A - Polymer for spin on carbon hardmask and composition including same - Google Patents

Abstract

The present invention relates to a polymer for a spin-on carbon hardmask and a composition for a carbon hardmask comprising the same. Disclosed is a polymer comprising a bisphenylphenol fluorine-based monomer and satisfying specific requirements for weight-average molecular weight, and more desirably, disclosed is a spin-on carbon hardmask organic material comprising a polymer in which an additive monomer component is polymerized for the bisphenylphenol fluorine-based monomer. Since the bisphenylphenol fluorine-based polymer has an excellent optical property, and at the same time, is able to be applied on a substrate via spin coating, a semiconductor hyperfine patterning process can be performed after performing a photolithography process by using the composition.

Description

TECHNICAL FIELD The present invention relates to a polymer for a spin-on carbon hard mask, and a composition for a carbon hard mask containing the same. BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to a polymer for a spin-on carbon hard mask and a composition for a carbon hard mask containing the same, and more particularly to a novel polymer for a spin-on carbon hard mask which satisfies a specific weight average molecular weight requirement from a biphenyl phenol fluorene monomer The present invention provides an organic material for a spin-on carbon hard mask, which comprises a polymer for a spin-on carbon hard mask, which can be applied by spin coating on a substrate and which can be subjected to a semiconductor ultra-fine patterning process after a photolithography process, And a composition for a carbon hard mask containing the same.

In recent years, with the miniaturization and integration of semiconductor devices, the thickness of the photoresist film and the pattern has gradually become thinner in order to prevent the collapse of the photoresist pattern as the pattern size becomes smaller.

However, since it is difficult to etch the etching layer by using the thinned photoresist pattern, a silicon film, an insulating film, a conductive film, or the like is introduced as an inorganic film or an organic film having high etching resistance between the photoresist and the etching layer , And these films are referred to as a lower layer film or a hard mask.

The step of etching the lower layer film by using the photoresist pattern and patterning and then etching the etching layer by using the pattern of the lower layer film is called a resist lower layer film process. At this time, the inorganic underlayer film used in the lower layer film process is formed of silicon nitride, silicon oxynitride, polysilicon, titanium nitride, amorphous carbon, or the like, and is usually subjected to chemical vapor deposition (CVD) Lt; / RTI >

The lower layer film produced by the chemical vapor deposition method is excellent in etching selectivity and etching resistance, but has some problems such as particle problem and initial facility investment cost.

Therefore, a microlithography process using a KrF excimer laser or a light source of an ArF excimer laser is used in order to meet the miniaturization of a semiconductor device pattern. One of techniques for making a pattern as small as possible in this process is a hard mask process. Therefore, research on a spin-on carbon hard mask material capable of spin application in place of the conventional deposition hard mask process has been actively studied.

Recent vapor deposited materials have been replaced by spin-on etch masks. For example, van Delft et al ., J. Vac . Sci . Technol . (HSQ) two-layer laminate as reported in B- 18 (2000) 3419, as well as a separate 40 nm line with an aspect ratio of 20: 1, as well as a 40 nm half-pitch Resolution. However, if the underlying HSQ layer is etched using fluorine, there is a problem that the patterned novolak-shaped part expands and waveform deformation is observed. Therefore, there is a demand for a spin-on hard-mask material which is resistant to etching of a lower layer using fluorine without deformation and capable of forming a high-resolution pattern.

For example, Korean Patent Laid-Open Publication No. 2015-28221 discloses a composition for spin-on hard-mask formation comprising a fullerene derivative and a cross-linking agent having two or more heat or catalytic reactive groups.

However, the inventors of the present invention have conducted research on a material for a carbon hard mask capable of spin application in place of the conventional deposition hard mask process. As a result, it has been found that a bismuth molybdenum compound containing a biphenyl phenol fluorene monomer, The present invention provides an organic material for a spin-on carbon hard mask comprising a novel polymer or a polymer obtained by polymerizing the above-mentioned bisphenyl phenol fluorene monomer with an addition monomer component, and a composition comprising the same is prepared by spin coating It is possible to perform a semiconductor ultrafine patterning process after the photolithography process using the above composition, thereby completing the present invention.

It is an object of the present invention to provide an organic material for a spin-on carbon hard mask capable of forming a high-resolution pattern.

It is another object of the present invention to provide a composition containing the organic material for the spin-on carbon hard mask.

In order to achieve the above object, the present invention provides an organic material for a spin-on carbon hard mask comprising a polymer containing a biphenyl phenol fluorene monomer represented by the following formula (1) and having a weight average molecular weight of 1,000 to 10,000 do.

Formula 1

Specifically, the organic material for the spin-on carbon hard mask of the present invention is a polymer obtained by the polymerization reaction of at least one of the monomers represented by the following formulas (2) to (5) with the biphenyl phenol fluorene monomer .

(2)

(3)

Formula 4

Formula 5

More specifically, as the organic material for the spin-on carbon hard mask of the present invention, the first preferred embodiment is made of a polymer represented by the following formula (6).

6

(Wherein R ₁ and R ₂ may be the same or independent and are any one of the compound groups represented by the general formulas (2) to (5), and n is a natural number of 1 to 10 as the repeating unit.

A specific example of the organic material of the first embodiment is a polymer represented by the following general formula (7).

Formula 7

(In the above formula, n1 is a natural number of 1 to 10 as a repeating unit.)

Further, as the organic material for the spin-on carbon hard mask of the present invention, there is provided a polymer represented by the following formula (8).

8

(In the above formula, n1 is a natural number of 1 to 10 as a repeating unit.)

As a second preferred embodiment of the organic material for a spin-on carbon hard mask of the present invention, a polymer represented by the following general formula (9) is provided.

Formula 9

(Wherein l is 2 to 20, m is 0 to 40, and n is 1 to 65.)

Further, the present invention provides a composition for a spin-on carbon hard mask wherein 1 to 25% by weight of any one of the polymers selected from organic materials for spin-on carbon hard masks is contained in an organic solvent.

The present invention provides an organic material for a spin-on carbon hard mask comprising a novel polymer satisfying the requirement of a specific weight average molecular weight from a biphenyl phenol fluorene monomer, Can be applied. Therefore, it is possible to laminate in general coating equipment without special special equipment, so the coating time is short and simple, and thickness and hydrophilicity can be adjusted freely according to the additives added to the solution.

Furthermore, the ultrafine pattern of the semiconductor device can be formed using the composition containing the organic material for the spin-on carbon hard mask of the present invention.

Fig. 1 is a graph showing the relationship between The results of gel permeation chromatography (GPC) of measuring the weight average molecular weight of the polymer,
Fig. 2 is a graph showing the relationship between The results of gel permeation chromatography (GPC) of measuring the weight average molecular weight of the polymer,
Fig. 3 is a graph showing the relationship between Gel permeation chromatography (GPC) results of measuring the weight average molecular weight of the polymer.

Hereinafter, the present invention will be described in detail.

The present invention provides an organic material for a spin-on carbon hard mask comprising a polymer containing a biphenyl phenol fluorene monomer represented by the following formula (1) and having a weight average molecular weight of 1,000 to 10,000.

Formula 1

Polymers polymerized from the biphenyl phenol fluorene monomer have excellent optical, mechanical and etch selectivity properties due to their strong absorption properties in short wavelength regions (e.g., 157, 193, 248 nm) And at the same time, it is possible to provide a coatable property using a spin-on coating technique.

In addition, the monomer represented by the formula (1) of the present invention satisfies the high refractive index required for a polymer used in a spin-on carbon hard mask, and at the same time, maximizes the ratio of carbon atoms to that of a known bisphenol fluorene- , Which improves the high dry etch resistance for the polymerized polymer.

Accordingly, the biphenyl phenol fluorene monomer represented by the above formula (1) is preferable as an essential polymerization component constituting the organic material for the spin-on carbon hard mask of the present invention.

Specifically, the polymer constituting the organic material for the spin-on carbon hard mask of the present invention is prepared by polymerizing the biphenyl phenol fluorene monomer with at least one additional monomer component of the monomers represented by the following formulas (2) to (5) .

(2)

(3)

Formula 4

Formula 5

The polymer for a spin-on carbon hard mask of the present invention preferably has a weight average molecular weight (Mw) of 1,000 to 10,000, preferably 2,000 to 10,000, more preferably 2,000 to 10,000, as measured by gel permeation chromatography (GPC) 6,000, and more preferably 3,000 to 5,000. If the weight average molecular weight (Mw) of the polymer is less than 1,000, the coating property, heat resistance, and etching resistance may be lowered. If the weight average molecular weight (Mw) exceeds 10,000, It may not be uniformly applied.

The first preferred embodiment of the organic material for a spin-on carbon hard mask of the present invention satisfying the above requirements is composed of a polymer represented by the following formula (6).

6

(Wherein R ₁ and R ₂ may be the same or independent and are any one of the compound groups represented by the general formulas (2) to (5), and n is a natural number of 1 to 10 as the repeating unit.

More preferably, the organic material of the present invention is a polymer represented by the following formula (7).

Formula 7

(In the above formula, n1 is a natural number of 1 to 10 as a repeating unit.)

Specifically, the polymer represented by the formula (7) is a polymer (n1 = 4) having a weight average molecular weight (Mw) of 3,620 as disclosed in Example 1 of the present invention and can be obtained by a polymerization reaction between monomers. Without being limited, various polymers may be provided depending on the selection of the additive monomer component.

As another example, the organic material for the spin-on carbon hard mask of the present invention provides a polymer represented by the following formula (8).

8

(In the above formula, n1 is a natural number of 1 to 10 as a repeating unit.)

Further, a second preferred embodiment of the organic material for a spin-on carbon hard mask of the present invention provides a polymer represented by the following formula (9).

Formula 9

(Wherein l is 2 to 20, m is 0 to 40, and n is 1 to 65.)

An example of the polymer represented by the above formula (9) is a polymer represented by the formula (10).

The polymer represented by the following formula (10) can be obtained by a polymerization reaction between the respective monomers as described in Example 2 or Example 3, but not limited thereto, and various polymers may be provided depending on the selection of the molar ratio with the additional monomer component . The above polymers meet the requirements of the preferred weight average molecular weight required for spin-on carbon hardmask applications.

10

Wherein l and n are the same as defined in the above formula (9).

Further, the present invention provides a composition for a carbon hard mask wherein 1 to 25% by weight of any one of the polymers selected from the organic materials for the spin-on carbon hard mask is contained in the organic solvent.

In the composition for the carbon hard mask, the content of the polymer constituting the organic material for the spin-on carbon hard mask is 1 to 25% by weight, preferably 3 to 20% by weight, more preferably 4 to 16% , And the content of the organic solvent accounts for the remainder excluding the solid content of the polymer and the like.

The organic solvent used in the present invention is soluble in a polymer and can be used without limitation in an organic solvent group commonly used for hard mask applications. As a preferable example, propylene glycol monomethylether acetate PGMEA), propylene glycol monomethyl ether (PGME), cyclohexanone (CH), ethyl lactate (EL), gamma-butyrolactone (GBL) Shape can be used.

Thus, the composition for the carbon hard mask of the present invention is not limited, but it may be appropriate to coat the substrate by spray coating, blade coating, spin coating, or a combination thereof.

The carbon hard mask composition according to the present invention can be applied on a substrate by spin coating, so that it can be laminated in general coating equipment without any additional equipment, the coating time is short and simple, The thickness and the hydrophilicity can be adjusted freely according to the additives added to the resin.

In this case, the spin speed range is preferably 100 to 8000 rpm, more preferably 200 to 2000 rpm, still more preferably 800 to 1500 rpm. The spin time is preferably 10 seconds to 150 seconds.

The substrate coated by any one of the above methods may suitably be soft baked prior to crosslinking, wherein the soft baking temperature range is preferably from 50 to 150 < 0 > C.

The composition for a carbon hard mask of the present invention may further contain a crosslinking component, an acid generator, and a surfactant.

The crosslinking component is a compound having two or more crosslinking functional groups. The crosslinking functional group is an oxetanyl group, an oxazoline group, a cyclocarbonate group, an alcoholic silyl group, an amino A methiol group or an alkoxymethyl group, an aziridinyl group, a methiol group, an isocyanate group, an alkoxymethylamino group, or a polyfunctional epoxy group. MX-270, MX-280, MX-390, and 2 - {[4- (2-hydroxyethyl) (2 - {[4- (2-oxiranylmethoxy) phenoxy] methyl} oxirane) and the like can be used.

At this time, the content of the crosslinking component is 0 to 4% by weight, preferably 0.5 to 3% by weight, based on the whole composition. When the content of the crosslinking component exceeds 4% by weight, there is a fear that the stability of the resin sheet is lowered.

Further, the acid generator is added to lower the temperature of the crosslinking reaction of the polymer and to improve the crosslinking ratio. As the acid generator, a conventional photo acid generator and a thermal acid generator may be used. Preferably, a thermal acid generator having a high efficiency as a catalyst at a temperature higher than that of the photoacid generator can be used. For example, a thermal acid generator such as TAG-series manufactured by King Industries Co., Ltd. can be used. When the acid generator is used, p-toluenesulfonic acid monohydrate, pyridine p-toluenesulfonic acid, 2,4,4,6-tetrabromocyclohexadiene Benzoin tosylate, 2-nitrobenzyl tosylate, and other alkyl esters of organic sulfonic acids.

Thus, the preferable content of the acid generator is 0.25% by weight or less, preferably 0.05 to 0.2% by weight, based on the composition for the entire spin-on carbon hard mask. At this time, when the amount of the acid generator used exceeds 0.25% by weight, the stability of the resist may be lowered.

The surfactant is used to improve coating defects that occur as the polymer content of the organic material for the spin-on carbon hard mask increases.

For example, Sulfinol series, F-series (F-410, F-444, F-477, R-08, R-30 and the like) of DIC Co. can be used as a commercial surfactant, The preferred content is 0.0001 to 0.001% by weight, preferably 0.0001 to 0.0008% by weight, based on the composition for the entire spin-on carbon hard mask. If the content of the surfactant exceeds 0.001% by weight, It can become bad.

Hereinafter, the present invention will be described in more detail with reference to Examples.

The present invention is intended to more specifically illustrate the present invention, and the scope of the present invention is not limited to these embodiments.

< Example  1>

(0.1 mol) of 1-hydroxypyrrole, 14.4 g (0.1 mol) of 1-naphthol, 9.1 g (0.3 mol) of paraformaldehyde, After 17.1 g (0.09 mol) of para-toluenesulfonic acid monohydrate was suspended in 150 ml of propylene glycol monomethyl ether acetate (PGMEA), the solution was polymerized by stirring at 100 DEG C for 30 hours. After completion of the reaction, the reaction mixture was cooled to room temperature, p-toluenesulfonic acid was removed using a mixed solvent of water and methanol (1:10 by volume), and the low molecular weight was removed using methanol to obtain a weight average molecular weight Mw) of 3,620 (n1 = 4) was obtained. The gel permeation chromatography (GPC) measurement results of the obtained polymer are shown in Fig.

Formula 7

< Example  2>

(0.087 mol) of bis (ortho-phenylphenol) fluorene, 25.2 g (0.174 mol) of 1-naphthol, 9.0 g (0.3 mol) of paraformaldehyde and 13.2 g (0.069 mmol) of para- Was suspended in 320 ml of propylene glycol monomethyl ether (PGME), and the solution was polymerized by stirring at 100 DEG C for 44 hours. After completion of the reaction, the reaction mixture was cooled to room temperature, and 100 ml of tetrahydrofuran and 11 ml of 28% aqueous ammonia were added and stirred to neutralize. The reaction mixture was added dropwise to 2100 ml of n-hexane for 1 hour, stirred for 1 hour, and filtered to obtain a wet powder. The wet powder was dissolved in 200 ml of ethyl acetate, filtered to remove insolubles, and the organic layer was washed with ultrapure water. The obtained organic layer was added dropwise to 280 ml of n-hexane to produce a solid phase powder to obtain a polymer (l = 5, n = 10) having a weight average molecular weight (Mw) of 4,275 represented by the formula (9). The results of gel permeation chromatography (GPC) measurement of the obtained polymer are shown in FIG.

10

< Example  3>

A mixture of 55.3 g (0.110 mol) of bis (ortho-phenylphenol) fluorene, 12.0 g (0.055 mol) of 1-hydroxypyrrole, 6.6 g (0.220 mol) of paraformaldehyde, 11.6 g of para-toluenesulfonic acid monohydrate 0.061 mmol) was suspended in 320 mL of propylene glycol monomethyl ether (PGME), and the solution was polymerized by stirring at 100 DEG C for 50 hours. After completion of the reaction, the reaction mixture was cooled to room temperature, and 100 ml of tetrahydrofuran and 11 ml of 28% aqueous ammonia were added and stirred to neutralize. The reaction mixture was added dropwise to 2100 ml of n-hexane for 1 hour, stirred for 1 hour, and filtered to obtain a wet powder. The wet powder was dissolved in 200 ml of ethyl acetate, filtered to remove insolubles, and the organic layer was washed with ultrapure water. The obtained organic layer was added dropwise to 280 ml of n-hexane to produce a solid phase powder to obtain a polymer (l = 8, n = 4) having a weight average molecular weight (Mw) of 4,477 represented by the formula (10). The gel permeation chromatography (GPC) measurement results of the obtained polymer are shown in Fig.

As described above, the present invention relates to a polymer containing a biphenyl phenol fluorene monomer and satisfying a requirement of a specific weight average molecular weight, more preferably the biphenyl phenol fluorene monomer, An organic material for a spin-on carbon hard mask consisting of the polymerized polymer was provided.

The composition for a carbon hard mask of the present invention is characterized in that the biphenyl phenol fluorene polymer has excellent optical properties with strong absorption in a short wavelength region (for example, 157, 193, 248 nm) Selectivity ratio, and is also applicable using a spin-on application technique.

In particular, the biphenyl phenol fluorene-based monomer represented by the formula (1) of the present invention has a high resistance to dry etching by maximizing the ratio of carbon atoms at the same time as it has a high requirement for a polymer used in a spin-on carbon hard mask .

Thus, a semiconductor ultrafine patterning process can be performed after the photolithography process using the composition for a carbon hard mask of the present invention.

While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (7)

An organic material for a spin-on carbon hard mask comprising a polymer containing a bisphenyl phenol fluorene monomer represented by the following formula (1) and having a weight average molecular weight of 1,000 to 10,000:
Formula 1

The spin-on carbon hardener according to claim 1, wherein the spin-on carbon hardener is composed of a polymer obtained by polymerizing the bismethylphenyl phenylene fluorene monomer with at least one additional monomer component of monomers represented by the following formulas (2) to Organic material for mask.
(2)

(3)

Formula 4

Formula 5

The organic material for a spin-on carbon hard mask according to claim 1, wherein the organic material is a polymer represented by the following Chemical Formula 6:
6

In the above formula, R ₁ and R ₂ may be the same or independent and are any one of the compound groups represented by the general formulas (2) to (5), and n is a natural number of 1 to 10 as the repeating unit. The organic material for a spin-on carbon hard mask according to claim 3, wherein the organic material is a polymer represented by the following formula (7): &lt; EMI ID =
Formula 7

In the above formula, n1 is a natural number of 1 to 10 as a repeating unit. The organic material for a spin-on carbon hard mask according to claim 1, wherein the organic material is a polymer represented by the following formula (8): &lt; EMI ID =
8

In the above formula, n1 is a natural number of 1 to 10 as a repeating unit. The organic material for a spin-on carbon hard mask according to claim 1, wherein the organic material is a polymer represented by the following formula (9): &lt; EMI ID =
Formula 9

Wherein l is from 2 to 20, m is from 0 to 40, and n is from 1 to 65. A composition for a spin-on carbon hard mask in which from 1 to 25% by weight of any one of the polymers selected from the organic materials for the spin-on carbon hard mask of any one of claims 1 to 6 is contained in an organic solvent.

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