Patent ID: 12227621

EXAMPLES

In the following, the present invention will be described in more detail, referring to Synthesis Examples and Examples, but the present invention is not limited to these.

[1] Synthesis of 3-(methoxy methyl)-1-(3-(triethoxy silyl) propyl) imidazolidine-2,4-dione (MOMHDITEOS)

50.00 g of 1-allylhydantoin (available from Tokyo Chemical Industry Co., Ltd.), 147.92 g of potassium carbonate (available from Kanto Chemical Co., Inc.), 500.00 g of N,N-dimethyl formamide were fed in and stirred at 40° C. for 30 min. After the stirring, the mixture was cooled down to 0° C. to 5° C., and 86.17 g of chloromethyl methyl ether (available from Tokyo Chemical Industry Co., Ltd.) was dropped at <10° C. After the dropping, the mixture was heated to 20° C. to 30° C., and 28.72 g of chloromethyl methyl ether (available from Tokyo Chemical Industry Co., Ltd.) was further dropped at <10° C. 1000.00 g of ethyl acetate was added therein and the mixture was filtered. 500.00 g of water was added and liquid separation was carried out. An organic layer thus separated was washed twice with 500.00 g of water. The organic layer thus obtained was concentrated, thereby obtaining 54.94 g of 1-allyl-3-methoxy methyl hydantoin with a yield of 41.8%.

36.13 g of 1-allyl-3-methoxy methyl hydantoin thus obtained, 1.87 g of Karstedt's cat (available from Sigma-Aldrich Co. LLC), and 180.65 g of toluene were fed in and heated to 60° C. Into that, 40.28 g of triethoxy silane (available from Tokyo Chemical Industry Co., Ltd.) was dropped. After that, reaction was carried out for 2 hours, and the mixture was concentrated. By performing distillation after the concentration, 40.00 g of MOMHDITEOS targeted was obtained with a yield of 64.7%.

1H NMR (500 MHz, CDCl3) was measured to find 54.90 (s, 2H), 3.91 (s, 2H), 3.81 (q, 6H), 3.41 (m, 5H), 1.69 (tt, 2H), 1.23 (t, 9H), 0.59 (t, 2H).

[2] Synthesis of Polymer (Hydrolysis Condensate)

Synthesis Example 1

20.2 g of tetraethoxy silane, 4.9 g of methyl triethoxy silane, 4.8 g of 3-(methoxy methyl)-1-(3-(triethoxy silyl)propyl) imidazolidine-2,4-dione, and 45.0 g of acetone were fed into a flask of 300 mL and stirred, and the mixture solution thus obtained was continuously stirred with a magnetic stirrer, and 25.0 g of aqueous nitric acid solution of 0.01 mol/L was dropped therein.

After the dropping, the flask was transferred to an oil bath adjusted to 85° C., and reflux was carried out for 240 min. After that, 60 g of propylene glycol monoethyl ether was added therein, and acetone, methanol, ethanol, and water were distilled off under reduced pressure, and concentration was performed, thereby obtaining a hydrolysis condensate (polymer) solution. Propylene glycol monoethyl ether was further added to the solution so as to achieve a solvent proportion of propylene glycol monoethyl ether of 100% and a solid residue content of 13% by weight at 140° C.

The polymer thus obtained corresponds to Formula (E1), and a weight average molecular weight thereof was Mw 2,000 as determined by GPC in terms of polystyrene.

Synthesis Example 2

18.1 g of tetraethoxy silane, 13.0 g of 3-(methoxy methyl)-1-(3-(triethoxy silyl)propyl) imidazolidine-2,4-dione, and 46.6 g of acetone were fed into a flask of 300 mL and stirred, and the mixture solution thus obtained was continuously stirred with a magnetic stirrer, and 22.4 g of aqueous nitric acid solution of 0.01 mol/L was dropped therein.

After the dropping, the flask was transferred to an oil bath adjusted to 85° C., and reflux was carried out for 240 min. After that, 60 g of propylene glycol monoethyl ether was added therein, and acetone, methanol, ethanol, and water were distilled off under reduced pressure, and concentration was performed, thereby obtaining a hydrolysis condensate (polymer) solution. Propylene glycol monoethyl ether was further added to the solution so as to achieve a solvent proportion of propylene glycol monoethyl ether of 100% and a solid residue content of 13% by weight at 140° C.

The polymer thus obtained corresponds to Formula (E2), and a weight average molecular weight thereof was Mw 1,800 as determined by GPC in terms of polystyrene.

Synthesis Example 3

21.9 g of tetraethoxy silane, 5.1 g of methyl triethoxy silane, 5.2 g of 3-(methoxy methyl)-1-(3-(triethoxy silyl)propyl) imidazolidine-2,4-dione, and 48.7 g of acetone were fed into a flask of 300 mL and stirred, and the mixture solution thus obtained was continuously stirred with a magnetic stirrer, and a mixture solution of 18.8 g of aqueous nitric acid solution of 0.2 mol/L and 0.31 g of dimethylaminopropyltrimethoxysilane was dropped therein.

After the dropping, the flask was transferred to an oil bath adjusted to 85° C., and reflux was carried out for 240 min. After that, 64 g of propylene glycol monoethyl ether was added therein, and acetone, methanol, ethanol, and water were distilled off under reduced pressure, and concentration was performed, thereby obtaining a hydrolysis condensate (polymer) solution. Propylene glycol monoethyl ether was further added to the solution so as to achieve a solvent proportion of propylene glycol monoethyl ether of 100% and a solid residue content of 13% by weight at 140° C. The polymer thus obtained corresponds to Formula (E3), and a weight average molecular weight thereof was Mw 2,500 as determined by GPC in terms of polystyrene.

Synthesis Example 4

19.5 g of tetraethoxy silane, 2.4 g of methyl triethoxy silane, 4.7 g of 3-(methoxy methyl)-1-(3-(triethoxy silyl)propyl) imidazolidine-2,4-dione, 3.8 g of 4-ethoxyethoxyphenyl trimethoxy silane, and 45.5 g of acetone were fed into a flask of 300 mL and stirred, and the mixture solution thus obtained was continuously stirred with a magnetic stirrer, and 24.1 g of aqueous nitric acid solution of 0.01 mol/L was dropped therein.

After the dropping, the flask was transferred to an oil bath adjusted to 85° C., and reflux was carried out for 240 min. After that, 60 g of propylene glycol monoethyl ether was added therein, and acetone, methanol, ethanol, and water were distilled off under reduced pressure, and concentration was performed, thereby obtaining a hydrolysis condensate (polymer) solution. Propylene glycol monoethyl ether was further added to the solution so as to achieve a solvent proportion of propylene glycol monoethyl ether of 100% and a solid residue content of 13% by weight at 140° C.

The polymer thus obtained corresponds to Formula (E4), and a weight average molecular weight thereof was Mw 2,600 as determined by GPC in terms of polystyrene.

Synthesis Example 5

19.8 g of tetraethoxy silane, 2.4 g of methyl triethoxy silane, 4.7 g of 3-(methoxy methyl)-1-(3-(triethoxy silyl)propyl) imidazolidine-2,4-dione, 3.2 g of glycidoxy propyl trimethoxy silane, and 45.3 g of acetone were fed into a flask of 300 mL and stirred, and the mixture solution thus obtained was continuously stirred with a magnetic stirrer, and 24.5 g of aqueous nitric acid solution of 0.01 mol/L was dropped therein.

After the dropping, the flask was transferred to an oil bath adjusted to 85° C., and reflux was carried out for 240 min. After that, 60 g of propylene glycol monoethyl ether was added therein, and acetone, methanol, ethanol, and water were distilled off under reduced pressure, and concentration was performed, thereby obtaining a hydrolysis condensate (polymer) solution. Propylene glycol monoethyl ether was further added to the solution so as to achieve a solvent proportion of propylene glycol monoethyl ether of 100% and a solid residue content of 13% by weight at 140° C.

The polymer thus obtained corresponds to Formula (E5), and a weight average molecular weight thereof was Mw 2,800 as determined by GPC in terms of polystyrene.

Synthesis Example 6

19.7 g of tetraethoxy silane, 4.8 g of methyl triethoxy silane, 5.7 g of 1,3-bis(methoxy methyl)-5-(3-(triethoxy silyl)propyl)-1,3,5-triazine-2,4,6-trione, and 45.3 g of acetone were fed into a flask of 300 mL and stirred, and the mixture solution thus obtained was continuously stirred with a magnetic stirrer, and 24.4 g of aqueous nitric acid solution of 0.01 mol/L was dropped therein.

After the dropping, the flask was transferred to an oil bath adjusted to 85° C., and reflux was carried out for 240 min. After that, 60 g of propylene glycol monoethyl ether was added therein, and acetone, methanol, ethanol, and water were distilled off under reduced pressure, and concentration was performed, thereby obtaining a hydrolysis condensate (polymer) solution. Propylene glycol monoethyl ether was further added to the solution so as to achieve a solvent proportion of propylene glycol monoethyl ether of 100% and a solid residue content of 13% by weight at 140° C.

The polymer thus obtained corresponds to Formula (E6), and a weight average molecular weight thereof was Mw 2,200 as determined by GPC in terms of polystyrene.

It should be noted that 1,3-bis(methoxy methyl)-5-(3-(triethoxy silyl)propyl)-1,3,5-triazine-2,4,6-trione was synthesized according to a method described in WO2019/003767 (and so forth).

Synthesis Example 7

16.9 g of tetraethoxy silane, 14.7 g of 1,3-bis(methoxy methyl)-5-(3-(triethoxy silyl)propyl)-1,3,5-triazine-2,4,6-trione, and 47.4 g of acetone were fed into a flask of 300 mL and stirred, and the mixture solution thus obtained was continuously stirred with a magnetic stirrer, and 20.9 g of aqueous nitric acid solution of 0.01 mol/L was dropped therein.

After the dropping, the flask was transferred to an oil bath adjusted to 85° C., and reflux was carried out for 240 min. After that, 60 g of propylene glycol monoethyl ether was added therein, and acetone, methanol, ethanol, and water were distilled off under reduced pressure, and concentration was performed, thereby obtaining a hydrolysis condensate (polymer) solution. Propylene glycol monoethyl ether was further added to the solution so as to achieve a solvent proportion of propylene glycol monoethyl ether of 100% and a solid residue content of 13% by weight at 140° C.

The polymer thus obtained corresponds to Formula (E7), and a weight average molecular weight thereof was Mw 2,000 as determined by GPC in terms of polystyrene.

Comparative Synthesis Example 1

24.1 g of tetraethoxy silane, 1.8 g of phenyl trimethoxy silane, 9.5 g of triethoxy methyl silane, and 53.0 g of acetone were fed into a flask of 300 mL and stirred, and the mixture solution thus obtained was continuously stirred with a magnetic stirrer, and 11.7 g of aqueous hydrochloric acid solution of 0.01 mol/L was dropped therein.

After the dropping, the flask was transferred to an oil bath adjusted to 85° C., and reflux was carried out for 240 min. After that, 70 g of propylene glycol monomethyl ether was added therein, and acetone, methanol, ethanol, and water were distilled off under reduced pressure, and concentration was performed, thereby obtaining a hydrolysis condensate (polymer) solution. Propylene glycol monomethyl ether was further added to the solution so as to achieve a solid residue content of 13% by weight at 140° C. The polymer thus obtained corresponds to Formula (C1), and a weight average molecular weight thereof was Mw 1,400 as determined by GPC in terms of polystyrene.

[3] Preparation of Composition to be Applied on Resist Pattern

The polysiloxanes (polymers) obtained in Synthesis Examples and Comparative Synthesis Example, acids, and solvents were mixed in proportions shown in Table 1, and the mixtures thus obtained were filtered with a filter of fluorine-based resin of 0.1 μm, thereby preparing compositions to be applied on a resist pattern.

Note that the proportions of addition of the polymers in Table 1 are not amounts of the solution of the polymers added, but the amounts of the polymers per se. Moreover, DIW stands for ultrapure water, PGEE stands for propylene glycol monoethyl ether, PGMEA stands for propylene glycol monomethyl ether acetate, PGME stands for propylene glycol monomethyl ether, MA stands for maleic acid, TPSNO3 stands for triphenyl sulfonium nitrate, TPSML stands for triphenyl sulfonium maleate, TPSTFA stands for triphenyl sulfonium trifluoro acetate, TPSC1 stands for triphenyl sulfonium hydrochloride, and TPSAc stands for triphenyl sulfonium acetate, respectively.

TABLE 1PolymerAdditive 1Additive 2SolventExample 1Synthesis Example 1MATPSNO3PGEEPGMEAPGMEDIW(parts by mass)10.030.057010812Example 2Synthesis Example 2MATPSMLPGEEPGMEAPGMEDIW(parts by mass)10.030.057010812Example 3Synthesis Example 3MA—PGEEPGMEAPGMEDIW(parts by mass)10.03—7010812Example 4Synthesis Example 4MATPSTFAPGEEPGMEAPGMEDIW(parts by mass)10.030.057010812Example 5Synthesis Example 5MATPSClPGEEPGMEAPGMEDIW(parts by mass)10.030.157010812Example 6Synthesis Example 6MATPSAcPGEEPGMEAPGMEDIW(parts by mass)10.030.057010812Example 7Synthesis Example 7MATPSNO3PGEEPGMEAPGMEDIW(parts by mass)10.030.057010812Comparative Example 1ComparativeMA—PGEEPGMEAPGMEDIWSynthesis Example 1(parts by mass)10.03—7010812Comparative Example 2ComparativeMATPSNO3PGEEPGMEAPGMEDIWSynthesis Example 1(parts by mass)10.030.057010812

[4] Preparation of Organic Resist Underlayer Film-Forming Composition

Under nitrogen environment, carbazole (6.69 g, 0.040 mol, available from Tokyo Chemical Industry Co., Ltd.), 9-fluorenone (7.28 g, 0.040 mol, available from Tokyo Chemical Industry Co., Ltd.), p-toluene sulfonic acid monohydrate (0.76 g, 0.0040 mol, available from Tokyo Chemical Industry Co., Ltd.) were fed into a 4-neck flask of 100 mL, and after that, 1,4-dioxane (6.69 g, available from Kanto Chemical Co., Inc.) was added therein, and the mixture thus obtained was stirred and heated to 100° C. so as to dissolve solids and start polymerization. After 24 hours, a reaction mixture was let stand to cool down to 60° C.

Into the reaction mixture thus cooled, chloroform (34 g, available from Kanto Chemical Co., Inc.) was added to dilute the reaction mixture, and the mixture thus diluted was dropped into methanol (168 g, available from Kanto Chemical Co., Inc.).

Precipitates thus obtained was filtered out, and residues of the filtration was dried at 80° C. for 24 hours, thereby obtaining 9.37 g of a targeted polymer represented by Formula (3-1) (hereinafter, abbreviated as PCzFL).

Note that1H-NMR measurement results of PCzFL were as below.

1H-NMR (400 MHz, DMSO-d6): δ7.03-7.55 (br, 12H), δ7.61-8.10 (br, 4H), δ11.18 (br, 1H)

Moreover, a weight average molecular weight of PCzFL was Mw 2,800 (Mw/Mn 1.77) as determined by GPC in terms of polystyrene.

20 g of PCzFL, 3.0 g of tetramethoxy methyl glycoluril (available from Nihon Cytec Industries Inc. (previously, Mitsui Cytec Ltd.), product name: Powder Link 1174) as a crosslinking agent, 0.30 g of pyridinium p-toluene sulfonate as a catalyst, and 0.06 g of MEGAFAC R-30 (available from DIC Corporation, product name) as a surfactant were mixed together, and the mixture thus obtained was dissolved in 88 g of propylene glycol monomethyl ether acetate. The solution thus obtained was filtered with a polyethylene-made microfilter with a pore size of 0.10 μm, and further filtered with a polyethylene-made microfilter with a pore size of 0.05 μm, thereby obtaining an organic resist underlayer film-forming composition for use in a lithography process performed with a multilayer film.

[5] Solvent Tolerance and Developer Solubility Tests

The compositions obtained in Examples 1 to 7 and Comparative Examples 1 and 2 were each applied on silicon wafers by using a spinner, and heated on a hot plate at 215° C. for 1 min, thereby forming Si-containing resist underlayer films (film thickness 20 nm).

After that, on each of the Si-containing resist underlayer films, a mixture solvent of propylene glycol monomethyl ether/propylene glycol monomethyl ether acetate (7/3 (V/V)) was applied and spin-dried. Based on a film thickness before the application that had been evaluated as to whether or not the film thickness after the application changed, the film thickness changes after the application of less than 1% was evaluated as “Good,” while the film thickness changes after the application of 1% or more was evaluated as “Poor.”

Moreover, on each of Si-containing resist underlayer films formed in the same manner, an alkali developer (TMAH 2.38% aqueous solution) was applied and spin-dried, and whether or not the film thickness after the application changed was evaluated. Based on the film thickness before the application, the film thickness changes after the application of less than 1% was evaluated as “Good,” while the film thickness changes after the application of 1% or more was evaluated as “Poor.”

TABLE 2Solvent ToleranceDeveloper SolubilityExample 1GoodGoodExample 2GoodGoodExample 3GoodGoodExample 4GoodGoodExample 5GoodGoodExample 6GoodGoodExample 7GoodGoodComparative Example 1PoorPoorComparative Example 2GoodGood

[6] Measurement of Dry Etching Rate

In measurement of a dry etching rate, the following etchers and etching gases were used.

Lam 2300 (available from Lam Research Corporation): CF4/CHF3/N2(fluorine-based gas)

RIE-10NR (available from SAMCO Inc.): O2(oxygen-based gas) The compositions thus obtained in Examples 1 to 7 and Comparative Example 2 were each applied on silicon wafers by using a spinner, and heated on a hot plate at 215° C. for 1 min, thereby forming Si-containing coating films (film thickness 20 nm).

Using silicon wafers with the respective Si-containing coating films thus obtained, dry etching rates were measured with CF4/CHF3/N2gas and O2gas as an etching gas.

Note that the drying etching rates using the O2gas are expressed as ratios with respect to a drying etching rate of an organic resist underlayer film with the 02 gas. The organic resist underlayer film was prepared in the following method. An organic resist underlayer film-forming composition was applied on a silicon wafer with a spinner, and heated on a hot plate at 215° C. for 1 min, thereby forming an organic resist underlayer film (film thickness 20 nm).

TABLE 3Fluorine-basedOxygen-based gas tolerancegas etching(against organic resistrate (nm/min)underlayer film)Example 1400.02Example 2450.03Example 3420.02Example 4380.03Example 5410.03Example 6420.03Example 7480.05Comparative Example 2300.02

[7] Formation of Resist Pattern with EUV Exposure: Positive-Type Alkali Development

The organic resist underlayer film-forming composition was applied on a silicon wafer with a spinner, and heated on a hot plate at 215° C. for 1 min, thereby forming an organic resist underlayer film with a film thickness of 90 nm.

On the organic resist underlayer film, the resist underlayer film-forming composition thus obtained in Example 1 was spin-coated and heated on a hot plate at 215° C. for 1 min, thereby forming a resist underlayer film layer (B) (20 nm).

Further on the resist underlayer film layer (B), an EUV resist solution (methacrylate resin-type, polyhydroxy styrene resin-type hybrid resist) was spin-coated, and heated on a hot plate at 130° C. for 1 min, forming an EUV resist layer (C). This was exposed with an EUV light exposure device (NXE 3300 B) (available from ASML Holding N.V.) under conditions of NA=0.33, σ=0.67/0.90, Dipole.

After the light exposure, post-exposure heating (110° C., 1 min) was carried out, and this was cooled down on a cooling plate to a room temperature, and developed for 60 seconds using an alkali developer (2.38% TMAH aqueous solution), and subjected to rinsing treatment, thereby forming a resist pattern.

In similar manners, resist patterns were formed using the resist underlayer film-forming compositions in Examples 2 to 7 and Comparative Example 2.

In addition, each of the patterns thus obtained was evaluated as to whether or not 16 nm of line-and-space with 32 nm pitches was formed by observing pattern shapes by pattern cross-section observation.

In Table 4, “Good” indicates a state where the shapes were between footing and undercutting and where no significant residues were in space portions. “Collapsed” indicates an unfavorable state that the resist patterns were peeled off and collapsed. In addition, “Bridge” indicates an unfavorable state that upper portions or lower portions of the resist patterns were in contact with one another.

TABLE 4Pattern shapeExample 1GoodExample 2GoodExample 3GoodExample 4GoodExample 5GoodExample 6GoodExample 7GoodComparative Example 2Collapsed