WO2018099835A1

WO2018099835A1 - Carbon-comprising underlayer-forming composition and methods for manufacturing carbon-comprising underlayer and device using the same

Info

Publication number: WO2018099835A1
Application number: PCT/EP2017/080440
Authority: WO
Inventors: Hiroshi Yanagita; Yuriko Matsuura; Yusuke Hama; Kazunori Kurosawa; Shigemasa NAKASUGI; Takashi Sekito; Go Noya
Original assignee: Az Electronic Materials (Luxembourg) S.A.R.L.
Priority date: 2016-11-30
Filing date: 2017-11-27
Publication date: 2018-06-07

Abstract

An object is to provide a carbon-comprising underlayer-forming composition having goodcoating formation property and gap filling property. Another object is to provide a method for manufacturing a device using the carbon-comprising underlayer-forming composition. [Solution] Provided are: a carbon-comprising underlayer-forming composition comprising a specific acrylate derivative and a specific organic solvent; a method for manufacturing a carbon-comprising underlayer using the carbon- comprising underlayer-forming composition; and a method for manufacturing a device using the carbon-comprising underlayer-forming composition.

Description

CARBON-COM PRISI N G U N DERLAYER-FORM I NG COM POSITION AN D METHODS FOR MAN U FACTU RI NG CARBON-COM PRISI NG

U N DERLAYER AN D DEVI CE USI N G TH E SAM E [Technical Field]

[0001 ]

The present invention relates to a carbon-comprising underlayer- forming composition used for forming a pattern by a lithography technique using a photoresist and to a method for manufacturing a carbon-comprising underlayer using the carbon-comprising underlayer-forming composition . The present invention also relates to methods for manufacturing a resist pattern and a device such as a semiconductor by a lithography technique using the carbon-comprising underlayer. [Background Art]

[0002]

Production processes of devices such as semiconductors generally employ fine processing performed by lithography technology using a photoresist. The fine processing includes the steps of: forming a thin photoresist layer on a semiconductor substrate such as a silicon wafer; covering the layer with a mask pattern corresponding to the pattern of the intended device; exposing the layer with active light such as ultraviolet light through the mask pattern ; developing the exposed layer to obtain a photoresist pattern ; and etching the substrate using the obtained

photoresist pattern as a protective coating, thus forming a fine unevenness corresponding to the above-described pattern . The recent development of high-density integration and three-dimensional integration of semiconductors has created a need to form another layer on a processed substrate having a fine unevenness and repeat the processing.

A photoresist layer or another coating can be formed by applying a solution to such a substrate and then curing the applied solution by irradiation with radioactive ray or by heating. The photoresist layer or the other coating is laminated on the substrate in a delicate environment as described above, and is required to exhibit good coating formation property and have other properties such as not being intermixed with another layer.

[0003]

Under such circumstances in the art, an attempt has been made to form a resist layer by applying a specific resist composition to a bare wafer and directly or indirectly activating the composition with radioactive ray to induce a crosslinking reaction of the composition (Patent Literature 1 ).

[Patent Literature]

[0004]

[Patent Literature 1 ]

I nternational Publication No. WO 2006/1 32139 A1 [Summary of I nvention]

[Technical Problem]

[0005]

The present inventors have considered that etching resistance and gap filling property in a complicated , finely processed substrate (for example, a stepped substrate) are useful for a carbon-comprising underlayer in a lithography step, made intensive studies, and found a composition to be described below. The present inventors have also discovered that such a composition is useful in the lamination process because the composition is curable by irradiation with specific ultraviolet radiation , permits a reduction in the amounts of additives, and allows avoidance of heating-induced damage to other organic layers. It has also been found that this composition is good in terms of coating formation property and thickness uniformity and is suitable for being formed into a coating on various types of substrates.

The present inventors have focused on the fact that in practically used semiconductors, unlike in test wafers, steps are unevenly distributed so that the distribution of high structures is locally dense or sparse (non- uniform). When a wafer has such a dense region and sparse region , it is difficult for a coating formed from a composition on the wafer to be completely flat, since there occur interaction of the composition , surface tension , and contraction during conversion to the coating. However, the composition discovered by the present inventors yielded high flatness even when formed into a coating on a wafer having a dense region and sparse region as described above.

[Solution to Problem]

[0006]

A carbon-comprising underlayer-forming composition according to the present invention comprises:

an acrylate derivative represented by formula (I ):

[Formula 1]

(I)

wherein

X is a C2-40 carbon-comprising skeleton,

Ri is hydrogen or Ci_-4 alkyl, and

n is 2, 3, 4, 5, 6, 7, or 8; and

one or more organic solvents.

In an aspect of the present invention, the one or more organic solvents comprised in the carbon-comprising underlayer-forming

composition comprise either a hydroxyl group or an ester-derivative represented by formula (II), or both a hydroxyl group and an ester- derivative group represented by formula (II).

[Formula 2]

In formula (II), R2 is a direct bond to a moiety of the organic solvent molecule other than the moiety of formula (II), a methyl, or carbon linked to R3 is hydrogen, or methoxy-substituted or unsubstituted C1 -3 alkyl, and

R₄ is a methyl or carbon linked to R2 to form a saturated ring.

The present invention also provides the carbon-comprising

underlayer-forming composition further comprising a high-carbon material, and the elements constituting the material satisfy formula (I I I ):

1 .5 < {total number of atoms/(number of C - number of O)} < 3.5 (I I I ), wherein

when the high-carbon material is a monomer, the total number of atoms is the number of the atoms in the whole monomer molecule, or when the high-carbon material is a polymer, the total number of atoms is the number of the atoms in one repeating unit,

the number of C is the number of carbon atoms in the total number of atoms,

the number of O is the number of oxygen atoms in the total number of atoms, and

the number of C is greater than the number of O.

A method for manufacturing a carbon-comprising underlayer according to the present invention comprises applying a carbon-comprising underlayer-forming composition according to the present invention onto a substrate and curing the carbon-comprising underlayer-forming composition . The conditions for curing the carbon-comprising underlayer-forming composition comprise irradiation with ultraviolet radiation having a

wavelength of 1 0-380 nm.

A method for manufacturing a planarizing coating according to the present invention comprises applying a carbon-comprising underlayer- forming composition according to the present invention onto a not-flat substrate and curing the carbon-comprising underlayer-forming composition to form a planarizing coating. The phrase "onto a substrate" as used for the manufacturing method means "on or above a substrate and below a photoresist layer" or "between a substrate and a photoresist layer". For example, a substrate-modifying layer may be formed over and in contact with a substrate, and a carbon-comprising underlayer may be formed over and in contact with the substrate-modifying layer.

A method for manufacturing a device according to the present invention comprises:

forming a carbon-comprising underlayer according to the present invention ;

applying a photoresist composition onto the carbon-comprising underlayer, or forming an interlayer on the carbon-comprising underlayer and applying a photoresist composition onto the interlayer;

curing the photoresist composition to form a photoresist layer;

exposing the substrate coated with the photoresist layer;

developing the exposed substrate to form a resist pattern ;

etching the carbon-comprising underlayer or the interlayer through the resist pattern as a mask to pattern the coating or the interlayer; and processing the substrate by etching it through the patterned carbon- comprising underlayer or the patterned interlayer as a mask.

[Effects of I nvention]

[0007]

A carbon-comprising underlayer formed from the composition according to the present invention is good in terms of coating formation property and thickness uniformity, has high etching resistance, is capable of gap filling of a processed substrate, and has high flatness. The composition is useful in the lamination process because the composition can be crosslinked by irradiation with ultraviolet irradiation and allows avoidance of damage to other layers. [Description of Embodiments]

[0008]

The above summary and the following details are provided for illustration of the present invention , and are not intended to limit the claimed invention .

When a numerical range is specified herein using the numerical range includes both of the numbers indicated before and after "-" and the unit is the same for the two numbers, unless otherwise explicitly stated.

For example, "5-25 mol%" means "5 mol% or more and 25 mol% or less".

The terms such as "C_x-y", " C_x-C_y", and "C_x" as used herein represent the number of carbon atoms in a molecule or substituent. For example,

"Ci-6 alkyl" refers to an alkyl chain having 1 -6 carbon atoms (such as methyl , ethyl, propyl, butyl, pentyl , and hexyl).

When a polymer as described herein has plural types of repeating units, these repeating units are copolymerized. The copolymerization may be any one selected from alternating copolymerization , random

copolymerization , block copolymerization, graft copolymerization , and a combination thereof, unless otherwise explicitly stated .

The unit of temperatures as indicated herein is degree Celsius, unless otherwise explicitly stated . For example, "20 degrees" means "20 degrees Celsius" (20°C).

[0009]

Carbon-Comprising U nderlayer-Forming Composition The carbon-comprising underlayer-forming composition according to the present invention is advantageously used in pattern formation by a lithography technique. The composition comprises: an acrylate derivative represented by formula (I ); and one or more organic solvents.

The carbon-comprising underlayer refers to a carbon-comprising coating formed between a substrate and a photoresist layer, and examples of the underlayer include a planarizing coating, an adhesive layer, and a bottom anti-reflective coating (BARC layer). The carbon-comprising underlayer alone may have the functions of these layers or coatings; for example, the carbon-comprising underlayer may function both as a planarizing coating and as a BARC layer. The carbon-comprising underlayer-forming composition is a composition for manufacturing a carbon-comprising underlayer. A preferred embodiment of the carbon- comprising underlayer is a planarizing coating, and a preferred embodiment of the carbon-comprising underlayer-forming composition is a planarizing coating-forming composition .

The planarizing coating-forming composition according to the present invention is a composition that can be formed into a coating placed between a substrate and a photoresist coating and having an upper surface (the surface facing the photoresist) having high flatness. Preferably, an interlayer (such as a Si-containing resist interlayer, an adhesive layer, a bottom anti-reflective coating, or a combination thereof) may be formed on the upper surface of the planarizing coating (the surface facing the photoresist), and the photoresist layer may be formed on the interlayer. The substrate used in the present invention may be a flat substrate, in view of high etching resistance of the composition and the ease of handling. Even when the substrate is a not-flat substrate, the composition of the present invention exhibits its effect sufficiently by virtue of having good gap filling property.

[001 0]

Acrylate Derivative Represented by Formula (I )

The carbon-comprising underlayer-forming composition comprises an acrylate derivative represented by formula (I ).

[Formula 1 ]

(I )

X is a C2-40 carbon-comprising skeleton . X is preferably linear or branched C2-15 alkylene, linear or branched C2-15 alkoxylene, C20-40 arylene, a C6-10 saturated hydrocarbon ring, hydroxy, or a composite group thereof. The total number of carbon atoms in the composite group is C2-40.

Preferred examples of X are classified into the following groups.

(X-1 ) A composite group of linear or branched C2-15 alkylene/linear or branched C2-15 alkoxylene/linear or branched C2-15 alkylene

(X-2) A composite group of linear or branched C2-15 alkylene/linear or branched C2-15 alkoxylene/linear or branched C2-15 alkylene/hydroxy

(X-3) A composite group of linear or branched C2-15 alkoxylene/C2o-4o arylene/linear or branched C2-15 alkoxylene

(X-4) A composite group of linear or branched C2-15 alkoxylene/C2o-4o arylene/linear or branched C2-15 alkylene/C2o-4o arylene/linear or branched C2-15 alkoxylene (X-5) A composite group of linear or branched C2-15 alkoxylene/C6-i o saturated hydrocarbon ring/linear or branched C2-15 alkoxylene

I n X, the linear or branched C2-15 alkylene is preferably branched C3-5 alkylene. In X, the linear or branched C2-15 alkoxylene is preferably linear C1 -3 alkoxylene. In X, the C20-40 arylene is preferably 9,9-diphenyl-9H- fluorene, pentacene, or perylene and more preferably 9,9-diphenyl-9H- fluorene. In X, the Ce-ι ο saturated hydrocarbon ring is preferably a C10 saturated hydrocarbon ring.

Ri is hydrogen or Ci _-4 alkyl. Ri is preferably hydrogen or methyl , and Ri is more preferably hydrogen .

n is 2, 3, 4, 5, 6, 7, or 8. Preferably, n is 2, 4, 5, or 6. More preferably, n is 2, 5, or 6.

For example, in the following compound , X is a composite group of linear C2 alkoxylene (ethoxy)/9,9-diphenyl-9H-fluorene/linear C2 alkoxylene (ethoxy), Ri is hydrogen, and n is 2.

[Formula 6]

9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene

The acrylate derivative is not limited to those consisting of a single compound , and may consist of a combination of a plurality of derivatives as long as the derivatives are represented by formula (I ). For example, both of the following two compounds may be comprised as the acrylate derivative in the planarizing coating-forming composition . [Formula 7]

[Formula 8]

[001 1 ]

I n a preferred aspect, the acrylate derivative of formula (I ) comprised in the composition consists of a single compound (one kind of compound), a combination of two derivatives, or a combination of three derivatives.

More preferably, the acrylate derivative of formula (I ) comprised in the composition consists of a single compound (one kind of compound) or a combination of two derivatives.

When a combination of derivatives is used , the derivatives may be copolymerized or may each be polymerized alone.

[0012]

Specific examples of the acrylate derivative of formula (I ) are shown below for illustrative purpose. These examples are not intended to limit the present invention .

The amount of the acrylate derivative of formula (I ) is preferably 1 - 1 5% by mass, more preferably 2-1 0% by mass, and even more preferably 2- 5% by mass relative to the total amount of the carbon-comprising

underlayer-forming composition . It should be understood that when the acrylate derivative of formula (I ) consists of a combination of a plurality of acrylate derivatives, the amount of the acrylate derivative of formula (I ) is determined as the sum of the amounts of the plurality of acrylate derivatives. The same applies in the following description . The acrylate derivative of formula (I ) may be one available from Mitsubishi Gas Chemical Company, I nc. or Shin-Nakamura Chemical Co. , Ltd .

The acrylate derivative of formula (I ) is suitably used in the carbon- comprising underlayer-forming composition to form an underlayer because the acrylate derivative of formula (I ) can easily be crosslinked. The acrylate derivative of formula (I ) is more suitable when the crosslinking is accomplished by a photocrosslinking (photocuring) process, because the group bracketed in formula (I ) is capable of receiving light to undergo self- crosslinking. [001 3]

Organic Solvent

The carbon-comprising underlayer-forming composition comprises one or more organic solvents. For example, the one or more organic solvents preferably comprise an organic solvent comprising a hydroxyl group, an organic solvent comprising an ester derivative, or an organic solvent comprising both a hydroxyl group and an ester derivative.

More preferably, the one or more organic solvents comprised in the carbon-comprising underlayer-forming composition comprise one or more organic solvents comprising a hydroxyl group and an ester-derivative group represented by formula (I I ) in a molar ratio of 23:77 to 77:23. The one or more organic solvents comprising a hydroxyl group and an ester-derivative group in a molar ratio of 23:77 to 77:23 correspond to the above-mentioned organic solvent comprising both a hydroxyl group and an ester derivative. [Formula 2]

R2 is a direct bond to a moiety of the organic solvent molecule other than the moiety of formula (I I ), a methyl, or carbon linked to R₄ to form a saturated ring. R2 is preferably a direct bond to a moiety of the organic solvent molecule other than the moiety of formula (I I ) or a methyl .

R3 is hydrogen or methoxy-substituted or unsubstituted C1-3 alkyl. R3 is preferably hydrogen or methoxy-substituted methyl.

R₄ is a methyl, or carbon linked to R2 to form a saturated ring. R₄ is preferably a methyl . When the organic solvent has one hydroxyl group and one ester- derivative group represented by formula (I I ) in one molecule, the molar ratio between the hydroxyl group and the ester-derivative group is 50:50. The number of carbon atoms in one molecule is preferably C3-10 and more preferably C4-6.

For example, ethyl lactate shown below is an organic solvent (C5) having a hydroxyl group and an ester-derivative group represented by formula (I I ) in one and the same molecule. R2 is a direct bond to a moiety other than the moiety of formula (I I ) (bond to a hydroxyl group via ethyl), R3 is hydrogen, and R₄ is a methyl. The abundance ratio between the hydroxyl group and the ester-derivative group represented by formula (I I ) is 50:50 in molar ratio.

[Formula 1 0]

For example, propylene glycol monomethyl ether (PGME) shown below is an organic solvent (C₄) having a hydroxyl group.

[Formula 1 1 ]

Propylene glycol monomethyl ether

For example, γ-butyrolactone shown below is an organic solvent (C₄) having an ester-derivative group represented by formula (I I ). R2 is carbon linked to R₄ to form a saturated ring, R3 is hydrogen , and R₄ is carbon linked to R2 to form a saturated ring. [Formula 12]

γ-Butyrolactone

[0014]

The organic solvent comprising a hydroxyl group, which is an embodiment of the one or more organic solvents comprised in the carbon- comprising underlayer-forming composition , is, for example, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, ethanol, n- propanol , i-propanol , n-butanol , i-butanol, sec-butanol , t-butanol , n-pentanol , i-pentanol , 2-methylbutanol, sec-pentanol , t-pentanol , 3-methoxybutanol, n- hexanol , 2-methylpentanol , sec-hexanol , 2-ethylbutanol, sec-heptanol , heptanol-3, n-octanol , 2-ethylhexanol, sec-octanol , n-nonyl alcohol, 2,6- dimethylheptanol-4, n-decanol , sec-undecyl alcohol , trimethylnonyl alcohol , sec-tetradecyl alcohol, sec-heptadecyl alcohol , phenol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol ,

phenylmethylcarbinol , diacetone alcohol, cresol, ethylene glycol , propylene glycol, 1 ,3-butylene glycol , pentanediol-2,4, 2-methylpentanediol-2,4, hexanediol-2,5, heptanediol-2,4, 2-ethylhexanediol-1 ,3, diethylene glycol , dipropylene glycol , triethylene glycol, tripropylene glycol , glycerin , or a mixture thereof. The organic solvent is preferably propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethanol , n-propanol , i- propanol , or a mixture thereof. The organic solvent is more preferably propylene glycol monomethyl ether or i-propanol and even more preferably propylene glycol monomethyl ether. The number of carbon atoms in the molecule of the organic solvent comprising a hydroxyl group is preferably C3- 10 and more preferably C3-5.

[001 5]

The organic solvent comprising an ester derivative, which is an embodiment of the one or more organic solvents comprised in the carbon- comprising underlayer-forming composition , is, for example, propylene glycol 1 -monomethyl ether 2-acetate (PGM EA), γ-butyrolactone, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, methyl acetate, γ-valerolactone, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, sec-butyl acetate, n-pentyl acetate, sec-pentyl acetate, 3-methoxybutyl acetate, methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methylcyclohexyl acetate, n-nonyl acetate, methyl acetoacetate, ethyl acetoacetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol mono-n-butyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, glycol diacetate, methoxytriglycol acetate, ethyl propionate, n-butyl propionate, i-amyl propionate, diethyl oxalate, di-n- butyl oxalate, diethyl malonate, dimethyl phthalate, diethyl phthalate, or a mixture thereof. The organic solvent is preferably propylene glycol 1 - monomethyl ether 2-acetate or γ-butyrolactone and more preferably propylene glycol 1 -monomethyl ether 2-acetate.

The number of carbon atoms in the molecule of the organic solvent comprising an ester-derivative group is preferably C3-10 , more preferably C_4- 7 , and even more preferably C5-7. For example, in a preferred aspect of the present invention , the organic solvent comprises PG ME and PG MEA mentioned above in a molar ratio of 1 : 1 .

[001 6]

The organic solvent comprising both a hydroxyl group and an ester derivative, which is an embodiment of the one or more organic solvents comprised in the carbon-comprising underlayer-forming composition , is, for example, methyl lactate, ethyl lactate, n-butyl lactate, i-butyl lactate, sec- butyl lactate, n-amyl lactate, n-propyl lactate, i-propyl lactate, n-butyl lactate, i-butyl lactate, sec-butyl lactate, n-pentyl lactate, sec-pentyl lactate, or a mixture thereof. The organic solvent is preferably methyl lactate, ethyl lactate, or n-butyl lactate, and the organic solvent is more preferably ethyl lactate. In an aspect of the present invention , the one or more organic solvents comprised in the carbon-comprising underlayer-forming composition consist only of any one selected from methyl lactate, ethyl lactate, and n-butyl lactate. In a more preferred aspect of the present invention , the one or more organic solvents consist only of ethyl lactate.

[001 7]

I n a preferred aspect, the one or more organic solvents of the carbon- comprising underlayer-forming composition comprise a hydroxyl group and an ester-derivative group represented by formula (I I ) in a molar ratio of 23:77 to 77:23. The present inventors have found that the presence of both the hydroxyl group and the ester-derivative group in the one or more organic solvents allows stable dissolution of the acrylate derivative of formula (I ) and a high-carbon material (such as a high-carbon material represented by formula (IV) described below) and leads to good coating formation property. For example, the presence of the hydroxyl group in the one or more organic solvents is believed to contribute to the solubility of the hydroxyl group of the high-carbon material of formula (IV), while the presence of the ester-derivative group in the one or more organic solvents is believed to contribute to the solubility of the aromatic ring of the high- carbon material of formula (IV). The abundance ratio between the hydroxyl group and the ester-derivative group represented by formula (I I ) in the one or more organic solvents is preferably 30:70 to 70:30 in molar ratio, more preferably 40:60 to 60:40 in molar ratio, even more preferably 45:55 to 55:45 in molar ratio, and still even more preferably 50:50 in molar ratio.

The amount of the one or more organic solvents (or the total amount of the two or more organic solvents) is preferably 75-99% by mass, more preferably 85-98% by mass, even more preferably 90-98% by mass, and still even more preferably 93-98% by mass relative to the total amount of the carbon-comprising underlayer-forming composition . The thickness of the underlayer to be formed can be controlled by increasing or reducing the amount of the one or more organic solvents relative to the total amount of the composition . The amount of water contained in the carbon-comprising underlayer-forming composition is preferably 0.1 % by mass or less and more preferably 0.01 % by mass or less. Given the relationship with another layer or coating, it is preferable for the composition to be free of water. In an aspect of the present invention , the amount of water contained in the carbon-comprising underlayer-forming composition is 0.00% by mass.

For example, an organic solvent such as cyclohexanone may be capable of dissolving the acrylate derivative of formula (I ) and a high- carbon material (such as a high-carbon material represented by formula (IV) described below) to allow coating formation ; however, such an organic solvent has the problems of toxicity and irritation potential .

[001 8] l n a preferred aspect of the present invention , the one or more organic solvents contained in the carbon-comprising underlayer-forming composition consist of two organic solvents, one of which is the organic solvent comprising a hydroxyl group and the other of which is the organic solvent comprising an ester-derivative group represented by formula (I I ).

[001 9]

High-Carbon Material

The carbon-comprising underlayer-forming composition may comprise a high-carbon material , and the high-carbon material is an organic substance the constituent elements of which satisfy formula (I I I ):

the number of C is the number of carbon atoms in the total number of atoms,

the number of O is the number of oxygen atoms in the total number of atoms, and

the number of C is greater than the number of O.

The high-carbon material is an organic substance different from that of formula (I ) and has neither an acrylate group nor a methacrylate group. The high-carbon material may be a low-molecular-weight material or high- molecular-weight material. The high-carbon material preferably consists only of carbon (C), oxygen (O), and hydrogen (H), and more preferably consists only of carbon (C) and hydrogen (H). The total number of atoms in formula (I I I ) includes the number of hydrogen atoms. Formula (III) is preferably formula (III)' or formula (III)".

1.5 < {total number of atoms/(number of C - number of O)} < 2.4 (III)' 1.8 < {total number of atoms/(number of C - number of O)} < 2.4 (III)" When the carbon-comprising underlayer-forming composition comprises the high-carbon material, a carbon-comprising underlayer having higher etching resistance can be obtained. In formation of the carbon- comprising underlayer, the high-carbon material is preferably in an unpolymerized form in the composition that has yet to be cured by ultraviolet irradiation or by ultraviolet irradiation subsequent to heating.

[0020]

The high-carbon material is preferably represented by formula (IV), (V), or (VI). These compounds satisfy formula (III) and preferably satisfy formula (III)' or formula (III)". The compounds will each be described below.

[Formula 3]

[Formula 4]

[

[0021 ]

The high-carbon material represented by formula (IV) is shown below. [Formula 3]

(IV) An is a direct bond, Ci-6 alkyl, C6-12 cycloalkyi, or Ce-14 aryl. Ari is preferably a direct bond, C1-6 alkyl, or phenyl, more preferably a direct bond, linear C3 alkyl, linear C6 alkyl, tertiary butyl, or phenyl, and even more preferably a direct bond or phenyl.

Ar2 is C1-6 alkyl, C6-12 cycloalkyi, or Ce-14 aryl. Ar2 is preferably isopropyl, tertiary butyl, C6 cycloalkyi, phenyl, naphthyl, phenanthryl, or biphenyl, and more preferably phenyl.

R5 and R6 are each independently C1-6 alkyl, hydroxy, halogen, or cyano. Ri and R2 are preferably each independently methyl, ethyl, propyl, isopropyl, tertiary butyl, hydroxy, fluorine, chlorine, or cyano, and more preferably each independently methyl, hydroxy, fluorine, or chlorine.

R7 is hydrogen, C1-6 alkyl, or Ce-14 aryl. R₇ is preferably hydrogen, C1-6 alkyl, or phenyl, more preferably hydrogen, methyl, ethyl, linear C5 alkyl, tertiary butyl, or phenyl, even more preferably hydrogen or phenyl, and still even more preferably hydrogen.

When Ar2 is C1-6 alkyl or Ce-14 aryl and R7 is C1-6 alkyl or Ce-14 aryl, Ar2 and R7 are optionally linked to each other to form a hydrocarbon ring.

r and s are each independently 0, 1, 2, 3, 4, or 5. r and s are preferably each independently 0 or 1 , and r and s are more preferably each independently 0.

At least one of the Ci, C2, and C3 rings each surrounded by the broken line is an aromatic hydrocarbon ring fused with the adjacent aromatic hydrocarbon ring Pi, and the total number of carbon atoms of the aromatic hydrocarbon ring and the aromatic hydrocarbon ring Pi is

preferably C10-14 and more preferably C10.

At least one of the C4, C5, and C6 rings each surrounded by the broken line is an aromatic hydrocarbon ring fused with the adjacent aromatic hydrocarbon ring P2, and the total number of carbon atoms of the aromatic hydrocarbon ring and the aromatic hydrocarbon ring P2 is preferably C10-14 and more preferably C10.

I n formula (IV), the bonding positions of R5 , 6 , and OH are not limited .

For example, the compound shown below can have the following structure of formula (IV). That is, the aromatic hydrocarbon ring Pi and the aromatic hydrocarbon ring C3 are fused with each other to form a naphthyl ring, and OH is bonded to the aromatic hydrocarbon ring C3. An is a direct bond , Ar2 and R7 are each phenyl, and A2 and R7 are linked to each other to form a hydrocarbon ring (fluorene).

[Formula 13]

When the carbon-comprising underlayer-forming composition comprises a high-carbon material represented by formula (IV), one or more organic solvents which comprise both a hydroxyl group and an ester- derivative group represented by formula (I I ) and in which the molar ratio between the hydroxyl group and the ester-derivative group is 23:77 to 77:23 are suitable since the high-carbon material of formula (IV) is highly soluble in such one or more organic solvents.

[0022]

Specific examples of the high-carbon material represented by formula (IV) are those represented by the following formulae.

I n formulae (IV)-1 , (IV)-2, and (IV)-3, An , Ar₂, R₅, Re, R₇, r, and s are as defined above. Preferred examples of An , Ar₂, Rs, R6, R7, r, and s are also each independently the same as described above. Among high- carbon materials of formula (IV), high-carbon materials represented by formula (IV)- 1 are more preferred .

The carbon-comprising underlayer can comprise one or more high- carbon materials represented by formula (IV). The use of one high-carbon material represented by formula (IV) is suitable. For example, both of the following two compounds may be comprised as the high-carbon materials in the planarizing coating-forming composition .

[Formula 1 8

Specific examples of the high-carbon material represented by form (IV) are shown below for illustrative purpose. These examples are not intended to limit the present invention .

[Formula 19]

[0024]

The high-carbon material represented by formula (V) is the following polymer.

[Formula 4]

Rs is hydrogen , C1 -6 alkyl, halogen, or cyano. Rs is preferably hydrogen , methyl , ethyl , propyl, isopropyl , tertiary butyl , fluorine, chlorine, or cyano, more preferably hydrogen, methyl, fluorine, or chlorine, and particularly preferably hydrogen .

Rg is Ci -6 alkyl, halogen, or cyano. Rg is preferably methyl, ethyl, propyl, isopropyl, tertiary butyl , fluorine, chlorine, or cyano, and more preferably methyl , fluorine, or chlorine.

p is 0, 1 , 2, 3, 4, or 5, preferably 0 or 1 , and particularly preferably 0. I n the high-carbon material represented by formula (V), the groups denoted by Rs may be the same as or different from each other, and the groups denoted by Rg may be the same as or different from each other. To reduce the production cost, it is preferable that the groups denoted by Rs be the same as each other and/or the groups denoted by Rg be the same as each other.

I n the present invention , weight-average molecular weights can be measured by gel permeation chromatography (GPC). In a preferred example of the measurement, the temperature of the GPC column is 40 degrees Celsius, tetrahydrofuran is used as an eluent at a flow rate of 0.6 mL/min , and monodisperse polystyrene is used as a standard .

The weight-average molecular weight (Mw) of the high-carbon material represented by formula (V) is preferably 5,000-50,000 and more preferably 8,000-40,000.

[0025]

The high-carbon material represented by formula (VI ) is shown below. [F

The ring P is phenyl having hydroxyl.

Y is Ci -6 alkyl, Ce-14 aryl, Ce-12 cycloalkyl , C7-20 aralkyl, C7-20 alkyl- substituted aralkyl, C7-20 cycloalkyl-substituted alkylcycloalkyl, or a direct bond connecting the two rings P to each other. In an embodiment, Y is preferably methyl , branched or linear C2-4 alkyl, phenyl , naphthyl ,

anthracene, C12 cycloalkyl, C 15 aralkyl , or a direct bond connecting the two rings P to each other, more preferably methyl, branched C2-3 alkyl, phenyl , naphthyl , anthracene, C12 cycloalkyl , anthracenylmethyl, or a direct bond connecting the two rings P to each other, and even more preferably methyl. I n another embodiment, Y is preferably methyl , branched or linear C2-4 alkyl, phenyl , naphthyl, anthracene, fluorene, C6 cycloalkyl, C12 cycloalkyl, C15 aralkyl, C alkyl-substituted aralkyl , or C15 cycloalkyl-substituted

alkylcycloalkyl , more preferably methyl, branched C2-3 alkyl, phenyl , naphthyl , anthracene, C12 cycloalkyl (cyclododecane), anthracenylmethyl , C11 alkyl-substituted aralkyl , or C 15 cycloalkyl-substituted alkylcycloalkyl , and even more preferably methyl or cyclododecane.

R10 is hydrogen , methyl , ethyl , phenyl, methylol (-C H2O H ), C1 -3 alkoxymethyl , or C6-12 cycloalkyl. In an embodiment, R10 is preferably methyl, phenyl , methylol, or methoxymethyl (Ci alkoxymethyl), more preferably methylol or methoxymethyl, and even more preferably methylol . I n another embodiment, R10 hydrogen is preferably methyl , phenyl, methylol , methoxymethyl (Ci alkoxymethyl), or C6 cycloalkyl , and more preferably methylol, methoxymethyl , or C6 cycloalkyl.

R11 is hydrogen or C1 -3 alkyl. R is preferably hydrogen or methyl and more preferably hydrogen .

m is 1 , 2, 3, or 4. When m is 2, 3, or 4, Y acts as a linker connecting the bracketed groups to each other, m is preferably 1 or 2 and more preferably 1 .

m' is 0 or 1 and preferably 1 .

I n a preferred aspect, Y or R10 (except when R10 is hydrogen) is bonded at the ortho position relative to the hydroxyl group directly bonded to phenyl in formula (VI ). In a more preferred aspect, R10 is bonded at the ortho position . I n a preferred aspect, Y or R10 (except when R10 is hydrogen) is bonded at the para position relative to the hydroxyl group directly bonded to phenyl in formula (VI ). In a more preferred aspect, Y is bonded at the para position . For example, in the compound shown below on the left, Y is methyl, Rio is methyl, R is hydrogen , m is 2, and m' is 1 . Y is bonded at the ortho position relative to the hydroxyl group directly bonded to phenyl in formula (VI ), and acts as a methylene linker connecting the two rings P to each other. Rio is bonded at the para position relative to the hydroxyl group directly bonded to phenyl .

For example, in the compound shown below on the right, Y is a direct bond connecting the two P rings to each other, Rio is methoxymethyl, R is methyl, m is 2, and m' is 1 .

[

[0026]

Specific examples of the high-carbon material represented by formula (VI ) are shown below for illustrative purpose. These examples are not intended to limit the present invention .

[Formula 21 ]

The high-carbon material is represented by formula (IV), (V), or (VI ), and the carbon-comprising underlayer-forming composition may comprise one or more such high-carbon materials. Preferably, the carbon- comprising underlayer-forming composition comprises one high-carbon material represented by formula (IV), (V), or (VI).

[0027]

I n the present invention , the amount of the high-carbon material is preferably 5-120% by mass and more preferably 7-1 00% by mass relative to the mass of the acrylate derivative of formula (I ) in the carbon-comprising underlayer-forming composition . Increasing the amount of the high-carbon material to 50-120% by mass relative to the mass of the acrylate derivative of formula (I ) in the carbon-comprising underlayer-forming composition can lead to an increase in etching resistance.

[0028]

Solid Component other than Acrylate Derivative of Formula (I ) and High- Carbon Material

The carbon-comprising underlayer-forming composition according to the present invention may further comprise a solid component that is other than the acrylate derivative of formula (I ) and the high-carbon material and that is formed into a coating. Such a solid component is different from the acrylate derivative of formula (I ) and the high-carbon material , and may be a monomer or a polymer. When formed into a coating, the solid

component may be copolymerized with, or polymerized separately from , the acrylate derivative of formula (I ), or both the copolymerization and separate polymerization may take place.

[0029]

Surfactant

The carbon-comprising underlayer-forming composition may further comprise a surfactant, a crosslinking agent, an acid generator, a radical generator, an agent for enhancing the adhesion to substrates, or a mixture thereof.

A surfactant is useful for preventing the occurrence of pinholes, striation or the like and improving the ease of application and solubility of the planarizing coating-forming composition . The amount of the surfactant in the composition is preferably 0.01 -5% by mass and more preferably 0.05- 3% by mass relative to the total amount of the composition .

Examples of the surfactant include: polyoxyethylene alkyl ether compounds such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, and polyoxyethylene oleyl ether; polyoxyethylene alkylaryl ether compounds such as polyoxyethylene octylphenol ether and polyoxyethylene nonylphenol ether; polyoxyethylene-polyoxypropylene block copolymer compounds; sorbitan fatty acid ester compounds such as sorbitan

monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan trioleate, and sorbitan tristearate; and polyoxyethylene sorbitan fatty acid ester compounds such as polyoxyethylene sorbitan monolaurate,

polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, and polyoxyethylene sorbitan tristearate. Other examples of the surfactant include: fluorosurfactants such as EFTOP (trade name) EF301 , EF303, and EF352 (manufactured by Tohkem Products Corporation), MEGAFACE (trade name) F1 71 , F 173, R-08, R-30, and R-201 1

(manufactured by DI C Corporation), Fluorad FC430 and FC431

(manufactured by Sumitomo 3M Limited), AsahiGuard (trade name) AG71 0 (manufactured by Asahi Glass Co. , Ltd .), and SU RFLON S-382, SC1 01 , SC1 02, SC 103, SC1 04, SC1 05, and SC1 06 (manufactured by Asahi Glass Co. , Ltd .); and organosiloxane polymers such as KP341 (manufactured by Shin-Etsu Chemical Co. , Ltd.).

[0030]

Photopolymerization I nitiator

A photopolymerization initiator is a compound that is modified upon receiving light and thereby causes or triggers polymerization of a solid component of a composition . Examples of the photopolymerization initiator include radical photopolymerization initiators (such as alkylphenone photopolymerization initiators, acylphosphine oxide photopolymerization initiators, photopolymerization initiators of the intramolecular hydrogen abstraction type, oxime ester photopolymerization initiators, and

photopolymerization initiator blends) and cationic photopolymerization initiators. Radical photopolymerization initiators that produce radicals upon receiving light are suitable for the composition of the present invention. A known polymerization initiator can be used , and preferred examples thereof include 2-methyl-1 -(4-methylthiophenyl)-2-morpholinopropan-1 -one, 2,2-dimethoxy-1 ,2-diphenylethan-1 -one, 1 -[4-(2-hydroxyethoxy)-phenyl]-2- hydroxy-2-methyl-1 -propan-1 -one, 1 -hydroxy-cyclohexyl-phenyl-ketone, 2- hydroxy-2-methyl-1 -phenyl-propan-1 -one, iodonium , (4-methyl phenyl )[4-(2- methylpropyl)phenyl]-hexafluorophosphate, a mixture of 2-[2-oxo-2- phenylacetoxyethoxy]ethyl ester and 2-(2-hydroxyethoxy)ethyl ester, phenylglycolate, and benzophenone. Examples of commercially-available photopolymerization initiators include: "OXE01 ", "OXE02", "369", "907", "651 ", "2959", "1 84", "250", and "754" of "I RGACU RE" series manufactured by BASF Japan Ltd . ; "MBF", "BP", and "1 1 73" of "DAROCU R" series manufactured by BASF Japan Ltd. ; and mixtures thereof. The

photopolymerization initiator preferably consists of a single

photopolymerization initiator.

I n the composition of the present invention , a photopolymerization initiation aid may be used in combination with the photopolymerization initiator. Examples of the photopolymerization initiation aid include triethanolamine and methyl diethanolamine.

[0031 ]

The amount of the photopolymerization initiator in the present invention is preferably 1 -20% by mass, more preferably 3-1 5% by mass, and even more preferably 5-1 0% by mass relative to the mass of the acrylate derivative of formula (I ) in the carbon-comprising underlayer- forming composition .

[0032]

The acrylate derivative of formula (I ) is self-crosslinkable, which allows a reduction in the amount of the photopolymerization initiator to be added to the carbon-comprising underlayer-forming composition . Whether to reduce the amount of the photopolymerization initiator can be selected depending on the apparatus and conditions employed for the process. When the amount of the photopolymerization initiator is reduced , the concentration of the photopolymerization initiator is preferably 0-1 000 ppm and more preferably 0-500 ppm in the carbon-comprising underlayer- forming composition . Given the ease of process control, the present invention may be implemented as an embodiment in which the crosslinking of the composition into a coating is allowed to proceed only by self- crosslinking of the acrylate derivative of formula (I ) without addition of any photopolymerization initiator (this means that the amount of the

photopolymerization initiator may be 0 ppm in the carbon-comprising underlayer-forming composition).

[0033]

Crosslinking Agent

A crosslinking agent can be added for the purpose of improving the coating formation property of the carbon-comprising underlayer to be formed , preventing intermixing with an upper layer (such as a silicon- containing interlayer and a resist), and preventing diffusion of a low- molecular-weight component into the upper layer.

Specific examples of crosslinking agents that can be used in the present invention include: melamine, guanamine, glycoluril, and urea compounds substituted by at least one group selected from a methylol group, an alkoxymethyl group, and an acyloxymethyl group; epoxy compounds; thioepoxy compounds; isocyanate compounds; azide compounds; and compounds having a double bond-containing group such as an alkenyl ether group. These may be used as an additive or may alternatively be introduced as a pendant group into a polymer side chain . Compounds containing a hydroxy group can also be used as a crosslinking agent.

Examples of the epoxy compounds mentioned above include tris(2,3- epoxypropyl) isocyanurate, trimethylolmethane triglycidyl ether,

trimethylolpropane triglycidyl ether, and triethylolethane triglycidyl ether. Specific examples of the melamine compounds include

hexamethylolmelamine, hexamethoxymethylmelamine, compounds derived by methoxymethylation of 1 -6 methylol groups of hexamethylolmelamine, mixtures of such compounds, hexamethoxyethylmelamine,

hexaacyloxymethylmelamine, compounds derived by acyloxymethylation of 1 -6 methylol groups of hexamethylolmelamine, and mixtures of such compounds. Examples of the guanamine compounds include

tetramethylolguanamine, tetramethoxymethylguanamine, compounds derived by methoxymethylation of 1 -4 methylol groups of

tetramethylolguanamine, mixtures of such compounds,

tetramethoxyethylguanamine, tetraacyloxyguanamine, compounds derived by acyloxymethylation of 1 -4 methylol groups of tetramethylolguanamine, and mixtures of such compounds. Examples of the glycoluril compounds include tetramethylolglycoluril, tetramethoxyglycoluril,

tetramethoxymethylglycoluril , compounds derived by methoxymethylation of 1 -4 methylol groups of tetramethylolglycoluril , mixtures of such compounds, compounds derived by acyloxymethylation of 1 -4 methylol groups of tetramethylolglycoluril , and mixtures of such compounds. Examples of the urea compounds include tetramethylolurea, tetramethoxymethylurea, compounds derived by methoxymethylation of 1 -4 of methylol groups of tetramethylolurea, mixtures of such compounds, and tetramethoxyethylurea.

Examples of the compounds containing an alkenyl ether group include ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1 ,2- propanediol divinyl ether, 1 ,4-butanediol divinyl ether, tetramethylene glycol divinyl ether, neopentyl glycol divinyl ether, trimethylolpropane trivinyl ether, hexanediol divinyl ether, 1 ,4-cyclohexanediol divinyl ether, pentaerythritol trivinyl ether, pentaerythritol tetravinyl ether, sorbitol tetravinyl ether, sorbitol pentavinyl ether, and trimethylolpropane trivinyl ether.

[0034] Examples of the crosslinking agent used in the present invention include those represented by formula (VII).

[Formula 22]

In formula (VII), l_3 is a direct bond or substituted or unsubstituted Ci- 3 alkyl. I_3 is preferably a direct bond or methyl and more preferably a direct bond. The substituent of C1-3 alkyl is preferably hydrogen, methyl, C6-10 aryl, or a substituent represented by formula (VIII) or formula (IX) and more preferably methyl or a substituent represented by formula (VIII). In formula (VII), R12 is hydrogen or methyl.

[Formula 23]

Specific examples of the crosslinking agent represented by formula (VII) include the following compounds, to which the scope of the present invention is not limited.

The amount of the crosslinking agent in the present invention is preferably 3-50% by mass and more preferably 5-40% by mass relative to the mass of the acrylate derivative of formula (I ) contained in the carbon- comprising underlayer-forming composition .

[0035]

The acrylate derivative of formula (I ) is self-crosslinkable, which allows a reduction in the amount of the crosslinking agent to be added to the carbon-comprising underlayer-forming composition . Whether to reduce the amount of the crosslinking agent can be selected depending on the apparatus and conditions employed for the process. When the amount of the crosslinking agent is reduced , the concentration of the crosslinking agent is preferably 0-1 ,000 ppm and more preferably 0-500 ppm in the carbon-comprising underlayer-forming composition . Given the ease of process control , the present invention may be implemented as an

embodiment in which the crosslinking of the composition into a coating is allowed to proceed only by self-crosslinking of the acrylate derivative of formula (I ) without addition of any crosslinking agent (this means that the amount of the crosslinking agent may be 0 ppm in the carbon-comprising underlayer-forming composition).

[0036]

Acid Generator

The carbon-comprising underlayer-forming composition according to the present invention may further comprise an acid generator. The amount of the acid generator contained in the composition is preferably 0.1 -1 0% by mass and more preferably 1 -7% by mass relative to the mass of the acrylate derivative of formula (I ).

The acid generator can be a thermal acid generator capable of generating a strong acid when heated . The thermal acid generator (TAG) used in the present invention can comprise one or more thermal acid generators which , when heated, generate an acid capable of reacting with the acrylate derivative of formula (I ) present in the present invention and capable of promoting crosslinking of the monomer. The acid is more preferably a strong acid such as sulfonic acid . The thermal acid generator is preferably activated at a temperature above 80 degrees. Examples of the thermal acid generator include: metal-free sulfonium salts such as triarylsulfonium , dialkylarylsulfonium , and diarylalkylsulfonium salts of strong non-nucleophilic acids; metal-free iodonium salts such as

alkylaryliodonium and diaryliodonium salts of strong non-nucleophilic acids; and ammonium, alkylammonium , dialkylammonium , trialkylammonium, and tetraalkylammonium salts of strong non-nucleophilic acids. Covalent thermal acid generators are also considered useful as additives, and examples include 2-nitrobenzyl esters of alkylsulfonic or arylsulfonic acids and other sulfonic acid esters which are thermally decomposed to give free sulfonic acid . Examples thereof include diaryliodonium perfluoroalkyl sulfonates, diaryliodonium tris(fluoroalkylsulfonyl)methides, diaryliodonium bis(fluoroalkylsulfonyl)methides, diaryliodonium

bis(fluoroalkylsulfonyl)imides, and diaryliodonium quaternary ammonium perfluoroalkyl sulfonates. Examples of labile esters include: nitrobenzyl tosylates such as 2-nitrobenzyl tosylate, 2,4-dinitrobenzyl tosylate, 2,6- dinitrobenzyl tosylate, and 4-nitrobenzyl tosylate; benzenesulfonates such as 2-trifluoromethyl-6-nitrobenzyl 4-chlorobenzenesulfonate and 2- trifluoromethyl-6-nitrobenzyl 4-nitrobenzenesulfonate; phenolic sulfonate esters such as phenyl 4-methoxybenzenesulfonate; quaternary ammonium tris(fluoroalkylsulfonyl)methides; quaternary alkylammonium

bis(fluoroalkylsulfonyl)imides; and alkylammonium salts of organic acids such as triethylammonium salt of 1 0-camphorsulfonic acid . A variety of amine salts of aromatic (anthracene, naphthalene, or benzene derivative) sulfonic acids, including those disclosed in U .S. Patent Nos. 3,474,054 (Patent Literature 2), 4,200,729 (Patent Literature 3), 4,251 ,665 (Patent Literature 4), and 5, 187,019 (Patent Literature 5), can be used as the TAG.

Specific examples of the acid generator that can be contained in the planarizing coating-forming composition include the following compounds, to which the scope of the present invention is not limited .

[Formula 26]

—f^~ Dodecylbenzenesulfonate, Triethylamine

[0037]

The acrylate derivative of formula (I ) is self-crosslinkable, which allows a reduction in the amount of the acid generator to be added to the carbon-comprising underlayer-forming composition . Whether to reduce the amount of the acid generator can be selected depending on the apparatus and conditions employed for the process. When the amount of the acid generator is reduced , the concentration of the acid generator is preferably 0-500 ppm in the carbon-comprising underlayer-forming composition .

Given the ease of process control , the present invention may be

implemented as an embodiment in which no acid generator is added to the carbon-comprising underlayer-forming composition (this means that the amount of the acid generator may be 0 ppm in the carbon-comprising underlayer-forming composition).

[0038]

Radical Generator

A radical generator can be added to the carbon-comprising

underlayer-forming composition to initiate polymerization . The radical generator generates radicals when heated, and examples thereof include azo compounds and peroxides. Specific examples of the radical generator include: organic peroxides, including hydroperoxides such as

diisopropylbenzene hydroperoxide, cumene hydroperoxide, and t-butyl hydroperoxide, dialkyl peroxides such as a,a-bis(t-butylperoxy-m- isopropyl)benzene, dicumyl peroxide, 2,5-dimethyl-2,5-bis(t- butylperoxy)hexane, t-butyl cumyl peroxide, di-t-butyl peroxide, 2,5- dimethyl-2,5-bis(t-butylperoxy)hexyne-3, and t-butyl peroxy-2- ethylhexanoate, ketone peroxides, peroxyketals such as n-butyl 4 ,4-d i(t- butylperoxy)valerate, diacyl peroxides, peroxydicarbonates, and

peroxyesters; and azo compounds such as 2,2'-azobisisobutyronitrile, 1 , 1 '- (cyclohexane-1 -1 carbonitrile), 2,2'-azobis(2-cyclopropylpropionitrile), and 2,2'-azobis(2,4-dimethylvaleronitrile). These thermal radical generators may be used alone or in combination with one another and are preferably used alone. These known radical generators can be used in the carbon- comprising underlayer-forming composition , and these radical generators are available, for example, from NOF CORPORATION .

[0039]

The acrylate derivative of formula (I ) is self-crosslinkable, which allows a reduction in the amount of the radical generator to be added to the carbon-comprising underlayer-forming composition . Whether to reduce the amount of the radical generator can be selected depending on the apparatus and conditions employed for the process. When the amount of the radical generator is reduced , the concentration of the radical generator is preferably 0-500 ppm in the carbon-comprising underlayer-forming composition . Given the ease of process control , the present invention may be implemented as an embodiment in which no radical generator is added to the carbon-comprising underlayer-forming composition (this means that the amount of the radical generator may be 0 ppm in the carbon-comprising underlayer-forming composition).

[0040]

Other Components

To the carbon-comprising underlayer-forming composition according to the present invention there may be further added other components such as an agent for enhancing the adhesion to substrates, a lubricating agent, a monomeric dye, a lower alcohol ( C 1 -6 alcohol), a surface leveling agent, an anti-foaming agent, and a preservative agent. The amount of these components in the composition is preferably 0.1 -1 0% by mass and more preferably 0.5-5% by mass relative to the amount of the acrylate derivative of formula (I ) in the composition . In an aspect of the present invention , the composition contains none of these components (0% by mass).

[0041 ]

Method for Manufacturing Carbon-Comprising U nderlayer

An aspect of the method for forming a carbon-comprising underlayer according to the present invention will be described.

As previously described , the carbon-comprising underlayer according to the present invention is a carbon-comprising coating formed between a substrate and a photoresist layer. In a preferred aspect of the present invention , the carbon-comprising underlayer is a planarizing coating. A "planarizing coating-forming composition" as defined in the present invention refers to a composition that can be formed into a coating placed between a substrate and a photoresist coating and having an upper surface (the surface facing the photoresist) having high flatness. Having high flatness means that the upper surface of the planarizing coating formed is horizontal. When the planarizing coating has high flatness, the variation in distance between the horizontally positioned bottom surface of a substrate (or the lowest substrate of a plurality of stacked substrates) and the upper surface of the coating is small . A "flat substrate" refers to a substrate in which the distance between the bottom surface and top surface is substantially constant (the variation in the distance is from 0-3% in the substrate). A "not-flat substrate" broadly refers to a substrate that is not a flat substrate.

Hereinafter, the present invention will be described with reference to the drawings for ease of understanding. To obtain a composition capable of being suitably formed into a coating on a substrate having a dense region and sparse region, the present inventors examined Examples and

Comparative Examples using a substrate shown in Figure 1 . An inexact reduction scale is used in Figures 1 and 2 for ease of understanding of the invention . Reference numeral 1 denotes an island region , which extends over 1 00 μηη or more. Reference numeral 2 denotes a sea region , which has 1 00 μπΊ width . Reference numeral 3 denotes a dense region , which extends over 1 00 μηη or more and in which wall structures with a depth of 1 00 nm are arranged in parallel, with a half pitch of 0.04 μηη and a line-to- space ratio of 1 :2.5. The substrate is a S1 O2 wafer having a sufficient width . Reference numeral 4 denotes the bottom surface of the substrate, and reference numeral 5 denotes the lower part of the substrate. When the substrate has a plurality of sea regions or gaps, a height or distance as described in the present invention is determined on the basis of one of the sea regions or gaps that is nearest the bottom surface (with the exception of a hole piercing through the substrate and a structure deviating from the intended design). Reference numeral 6 denotes the top part of the substrate. When the substrate has a plurality of top parts or gaps, a height or distance as described in the present invention is determined on the basis of one of the top parts that is farthest from the bottom surface (with the exception of a structure deviating from the intended design). Reference numeral 7 denotes a height between the island region and the sea region and corresponds to the difference between the distance from the top part of the island region to the bottom surface and the distance from the lower part contiguous with the island region to the bottom surface. Reference numeral 8 denotes a height between the dense region and the sea region and corresponds to the difference between the distance from the top part of the dense region to the bottom surface and the distance from the lower part contiguous with the dense region to the bottom surface. A planarizing coating is formed as shown by reference numeral 9 in Figure 2; it is difficult for the coating to be completely flat (being "completely flat" means that the distance from the coating to the bottom surface is constant). Reference numeral 1 0 denotes the height from the bottom surface of the substrate to the upper surface of the carbon-comprising underlayer formed on the island region , while reference numeral 1 1 denotes the height from the bottom surface of the substrate to the upper surface of the carbon-comprising underlayer formed on the dense region . The carbon-comprising

underlayer-forming composition discovered by the present inventors is advantageous because it can be formed into a coating on a not-flat substrate so that the difference between the heights denoted by reference numeral 10 and reference numeral 1 1 becomes small (so that high flatness is achieved). In evaluation of this composition , the difference between the heights is referred to as a "flatness index".

[0042]

Examples of the not-flat substrate in the present invention include a silicon-containing substrate with a difference in height between the top part and the lower part (namely a difference between the distance from the top part to the bottom surface and the distance from the lower part to the bottom surface) of 20-1 0,000 nm . The difference in height is preferably 50-1 ,000 nm and more preferably 50-500 nm. It is preferable to determine the difference in height in a structure where the top part and the lower part adjoin to each other as shown by reference numerals 7 and 8. Other examples of the not-flat substrate include a substrate having a wall or contact hole resulting from pre-treatment and further include a substrate in which the difference between the distance from the top part to the bottom surface and the distance from the lower part to the bottom surface is 30- 95% (preferably 30-80%) of the values mentioned above. The wall or contact hole can be formed by a known technique such as lithography, etching, or DSA, and preferably has an aspect ratio of 3-25 (preferably 5- 1 0). A substrate in which wall structures are merely arranged at intervals (see the region denoted by reference numeral 3 in Figure 1 ) is also a not- flat substrate. The advantage of the carbon-comprising underlayer-forming composition becomes evident, for example, when the substrate has both a region where such structures are densely arranged (dense region) and a region where such structures are absent (sparse region). Furthermore, the planarizing coating-forming composition according to the present invention is applicable to a substrate with a step (see the regions denoted by reference numeral 1 and reference numeral 2 in Figure 1 ). The height of the step is preferably 20-1 0,000 nm, more preferably 50-1 ,000 nm, and even more preferably 50-500 nm.

[0043]

When the carbon-comprising underlayer according to the present invention is applied to a flat substrate (bare wafer) and formed into a carbon-comprising underlayer by heating, the carbon-comprising underlayer can have a thickness of 20-2, 000 nm (preferably 1 00-500 nm, more preferably 200-400 nm).

As described above, the substrate used can be a flat substrate or a not-flat substrate. The advantage of the present invention becomes more evident when a not-flat substrate is used .

The substrate used can be a metal-containing substrate or a silicon- containing substrate. The substrate used in the present invention may be a single-layer substrate or a multi-layer substrate composed of a plurality of substrate layers. As the substrate there can be used any known substrate such as a silicon-coated substrate, silicon dioxide-coated substrate, silicon nitride-coated substrate, silicon wafer substrate (such as a S 1 O2 wafer), glass substrate, indium-containing substrate (such as an ITO substrate), or titanium-containing substrate (such as a titanium nitride or titanium oxide substrate).

I n the process for manufacturing a semiconductor according to the present invention, any known manner can be employed for the configuration of the substrate according to the conditions of the process. Examples of the configuration of the substrate include the multi-layer configurations listed below. The left-to-right direction in the following list corresponds to the bottom-to-top direction in the multi-layer configurations.

Silicon wafer substrate

Silicon wafer substrate/titanium-containing substrate Silicon wafer substrate/titanium-containing substrate/silicon-coated substrate

Silicon wafer substrate/titanium-containing substrate/silicon dioxide- coated substrate

Silicon wafer substrate/silicon dioxide-coated substrate/titanium- containing substrate

Silicon nitride substrate

Silicon nitride substrate/titanium-containing substrate

Silicon nitride substrate/titanium-containing substrate/silicon-coated substrate

Silicon nitride substrate/titanium-containing substrate/silicon dioxide- coated substrate

Silicon nitride substrate/silicon dioxide-coated substrate/titanium- containing substrate

One substrate to be laminated on another substrate can be formed by a known technique such as CVD. The one substrate can be patterned by a known lithography technique or etching technique. Still another substrate can be laminated on the patterned substrate by a known technique such as CVD.

[0044]

I n the present invention , the carbon-comprising underlayer-forming composition according to the present invention is applied by an appropriate application means such as a spinner or coater. The carbon-comprising underlayer-forming composition is good at gap filling of the substrate, since the solid component of the carbon-comprising underlayer-forming

composition is the acrylate derivative of formula (I ) at the moment when the composition is applied . In the application of the carbon-comprising underlayer-forming composition to the substrate, it is preferable for the substrate and the carbon-comprising underlayer-forming composition to come into direct contact with each other, but the carbon-comprising underlayer-forming composition may be applied with another thin coating (such as a substrate-modifying layer) interposed between the composition and the substrate. The application of the composition is followed by ultraviolet irradiation and/or heating to form a carbon-comprising underlayer. Preferably, the carbon-comprising underlayer-forming composition is cured by ultraviolet irradiation or by ultraviolet irradiation subsequent to heating.

As for the conditions of the ultraviolet irradiation of the applied carbon-comprising underlayer-forming composition, it is preferable to irradiate the composition with ultraviolet radiation having a wavelength of 1 0-380 nm at a total radiation dose of 1 00-1 0,000 mJ/cm². This irradiation induces polymerization (curing) of the acrylate derivative of formula (I ), thus resulting in a carbon-comprising underlayer. The wavelength is preferably short (1 0-200 nm, for example), because in this case self-crosslinking of the acrylate derivative of formula (I ) proceeds efficiently, which allows a reduction in the amount of the photopolymerization initiator and also leads to high thickness uniformity of the resulting carbon-comprising underlayer. The "thickness uniformity" as described herein refers to the degree of variation in thickness of a layer or coating formed by applying a composition to a flat substrate, and having "high thickness uniformity" means that the degree of variation is small . When the wavelength is long (longer than 200 nm and not longer than 380 nm, for example), a photopolymerization initiator capable of absorbing such ultraviolet radiation can be added to the carbon-comprising underlayer-forming composition to allow the curing of the composition to proceed efficiently.

The wavelength is preferably 1 0-200 nm, more preferably 100-200 nm, even more preferably 125-1 95 nm, and still even more preferably 1 70- 1 75 nm. The total radiation dose is preferably 1 00-5,000 mJ/cm², more preferably 200-1 , 000 mJ/cm², and even more preferably 300-800 mJ/cm². The above conditions can be appropriately modified depending on the thickness of the carbon-comprising underlayer to be formed .

As for the heating conditions employed when the carbon-comprising underlayer is cured by heating, the heating temperature is typically selected from the range of 200-400°C (preferably 225-375°C, more preferably 250- 350°C), and the heating time is typically selected from the range of 30-180 seconds (preferably 30-120 seconds). The heating can be carried out in separate steps (step bake). For example, the heating may be two-step heating consisting of: first heating by which the substrate is gap-filled along with removal of the solvent; and second heating by which the composition is mildly reflowed and thus formed into a coating with high flatness. For example, it is preferable that the first heating be performed at 200-300°C for 30-120 seconds and the second heating be performed at 300-400°C for 30-120 seconds. The curing of the carbon-comprising underlayer-forming composition may be accomplished only by heating, although combination of heating with ultraviolet irradiation is preferred . When the curing is performed only by heating, it is desirable to add a crosslinking agent, an acid generator, and/or a radical generator.

The ultraviolet irradiation or heating may be performed in an air atmosphere, whose oxygen concentration can be reduced to prevent oxidation of the carbon-comprising underlayer-forming composition and carbon-comprising underlayer. For example, the oxygen concentration may be adjusted to 1 ,000 ppm or less (preferably 1 00 ppm or less) by introducing an inert gas ( N2, Ar, He, or a mixture thereof) into the

atmosphere.

[0045] Addition of a high-carbon material to the carbon-comprising

underlayer-forming composition provides an increase in etching resistance and is suitable when the carbon-comprising underlayer is formed by a spin- on coating method . The evaluation of the etching rate can be made by a known technique. For example, the ratio of the etching rate of the coating to that of a resist (UV 161 0, manufactured by Dow Chemical Company) is preferably 1 .0 or less, more preferably 0.9 or less, and even more

preferably 0.8 or less.

[0046]

Formation of Photoresist Coating and Other Coatings

A photoresist composition (such as a positive-type photoresist composition) is applied to the carbon-comprising underlayer formed as described above. The positive-type photoresist composition as described herein refers to a photoresist composition that undergoes a reaction under light irradiation and whose light-irradiated portion has an increased solubility in a developer. The photoresist composition used is not particularly limited, and any positive-type photoresist composition , negative- type photoresist composition, or negative tone development (NTD) photoresist composition can be used , as long as the photoresist

composition is sensitive to the exposure light for pattern formation .

I n the method for manufacturing a resist pattern according to the present invention , a coating or layer other than the carbon-comprising underlayer formed from the carbon-comprising underlayer-forming composition and the photoresist coating may be present. An interlayer may be interposed between the carbon-comprising underlayer and the photoresist coating so that the carbon-comprising underlayer and the photoresist coating are not in direct contact with each other. The interlayer is a coating formed between the photoresist coating and the carbon-comprising underlayer, and examples of the interlayer include a bottom anti-reflecting coating (BARC layer), an inorganic hard mask interlayer (such as a silicon oxide coating, silicon nitride coating, or silicon oxynitride coating), and an adhesive coating. The inorganic hard mask interlayer can be formed by reference to Japanese Patent No. 5336306 B2 (Patent Literature 6). The interlayer may consist of a single layer or a plurality of layers. A top anti-reflective coating (TARC layer) may be formed on the photoresist coating.

I n the process for manufacturing a semiconductor according to the present invention , any known manner can be employed for the configuration of the layers other than the carbon-comprising underlayer according to the conditions of the process. Examples of the configuration that can be employed when the carbon-comprising underlayer is a planarizing coating include the following multi-layer configurations.

Substrate/planarizing coating/photoresist coating

Substrate/planarizing coating/BARC layer/photoresist coating

Substrate/planarizing coating/BARC layer/photoresist coating/TARC layer

Substrate/planarizing coating/inorganic hard mask

interlayer/photoresist coating/TARC layer

Substrate/planarizing coating/inorganic hard mask interlayer/BARC layer/photoresist coating/TARC layer

Substrate/planarizing coating/adhesive coating/BARC

layer/photoresist coating/TARC layer

Substrate/substrate-modifying layer/planarizing coating/BARC layer/photoresist coating/TARC layer

Substrate/substrate-modifying layer/planarizing coating/adhesive coating/BARC layer/photoresist coating/TARC layer These layers can be cured by heating and/or exposure after being applied or can be formed by a known technique such as CVD. These layers can be removed by a known technique (such as etching) and can each be patterned through an upper layer as a mask.

[0047]

I n an aspect of the present invention, the carbon-comprising underlayer can be formed on a not-flat substrate, and another substrate can be formed on the carbon-comprising underlayer. The other substrate can be formed , for example, by a technique such as CVD. The lower substrate and the upper substrate may have the same composition or different compositions. Still another layer can further be formed on the upper substrate. Forming the carbon-comprising underlayer or a photoresist coating as the other layer enables processing of the upper substrate. A photoresist coating or another coating that can be employed is as described above.

[0048]

Patterning and Device Manufacturing

The photoresist coating is exposed through a given mask. The wavelength of the light used for exposure is not particularly limited . The exposure is preferably performed with light having a wavelength of 1 3.5-248 nm. Specifically, KrF excimer laser (wavelength : 248 nm), ArF excimer laser (wavelength : 1 93 nm), or extreme ultraviolet light (wavelength : 1 3.5 nm) can be used, and KrF excimer laser is more preferred . These wavelengths may vary within ±1 %. The exposure can , if desired , be followed by post-exposure bake. The temperature for the post-exposure bake is selected from the range of 80-1 50°C, preferably 1 00-140°C, and the heating time for the post-exposure bake is selected from the range of 0.3-5 minutes, preferably 0.5-2 minutes. Next, development is performed with a developer. When a positive- type photoresist composition is used , the exposed part of the positive-type photoresist layer is removed by the development, resulting in the formation of a photoresist pattern . This photoresist pattern can be made finer using, for example, a shrink material .

[0049]

A 2.38% by mass aqueous TMAH solution is preferred as the developer used for the development in the above photoresist pattern formation method . The use of such a developer allows easy dissolution and removal of the carbon-comprising underlayer at room temperature. An additive such as a surfactant can be added to the developer. The temperature of the developer is typically selected from the range of 5-50°C, preferably 25-40°C, and the development time is typically selected from the range of 1 0-300 seconds, preferably 30-60 seconds.

The interlayer can be patterned through the resulting photoresist pattern as a mask. For pattern formation, a known technique such as etching (dry etching or wet etching) can be used . For example, the interlayer may be etched through the photoresist pattern as an etching mask, and then the carbon-comprising underlayer and substrate may be etched through the resulting interlayer pattern as an etching mask to form a pattern on the substrate. Alternatively, the inorganic hard mask interlayer may be etched through the photoresist pattern as an etching mask, the carbon-comprising underlayer may be etched through the resulting inorganic hard mask interlayer pattern as an etching mask, and then the substrate may be etched through the resulting carbon-comprising

underlayer pattern as an etching mask to form a pattern on the substrate. Wiring can be formed in the substrate using the pattern formed on the substrate. For example, the carbon-comprising underlayer can be suitably removed by dry etching with O2, CF₄, C H F3, C , or BCI3. O2 or CF₄ can be suitably used .

[0050]

Subsequently, the substrate, if necessary, is further processed to form a device. Such further processing can be done by using a known method . After formation of the device, the substrate, if necessary, is cut into chips, which are connected to a leadframe and packaged with a resin . I n the present invention , the packaged product is referred to as a device. Preferred examples of the device include a semiconductor, a solar cell , an organic EL element, and an inorganic EL element. A semiconductor is more preferred .

[0051 ]

Examples

Hereinafter, the present invention will be described with specific examples. These examples are given only for illustrative purpose and not intended to limit the scope of the present invention .

[0052]

Preparation Example 1 of Composition 1

An amount of 4.5 g of compound 1 (manufactured by Shin-Nakamura

Chemical Co. , Ltd .) shown below was dissolved as a solid component in 95.5 g of PGMEA serving as a solvent, and the resulting solution was used as composition 1 . [

Compound 1

[0053]

Example 1 -1 : Evaluation of Solubility and Stability for Composition 1

The extent of dissolution of the solute in composition 1 was visually observed and evaluated as follows.

A: The solute was fully dissolved .

B: The solute remained not fully dissolved .

When the solubility was rated as "A", the composition was stored at 0°C for 1 month , and the storage behavior was visually observed and evaluated as follows.

A: No precipitate was formed .

B: A precipitate was formed .

The evaluation result is shown in Table 1 .

[0054]

Example 1 -2: Evaluation of Coating Formation Property of Composition 1

Composition 1 was applied to a 12-inch bare silicon wafer using ACT 12 (an apparatus manufactured by Tokyo Electron Limited) at 1 ,500 rpm and was baked at 200°C for 1 minute. In the apparatus, the baked composition was irradiated with vacuum ultraviolet (VUV) radiation having a wavelength of 1 72 nm at a dose of 500 mJ/cm² to obtain a carbon- comprising underlayer. It was confirmed by a spectroscopic film thickness measurement system (Lambda Ace VM-31 1 0, manufactured by Dainippon Screen Mfg. , Co. , Ltd .) that this carbon-comprising underlayer had a thickness of 1 00 nm.

The surface of the carbon-comprising underlayer was observed with an optical microscope, and the coating formation property was evaluated as follows.

A: A uniform coating formed in which any marking resulting from uneven distribution of the composition was not found .

B: A marking such as striation (radial patch or stripe) was found . The evaluation result is shown in Table 2

[0055]

Example 1 -3: Evaluation of Solvent Resistance of Composition 1

To evaluate the resistance of the carbon-comprising underlayer to various solvents, experiments were conducted under various conditions described below.

A substrate on which a carbon-comprising underlayer as obtained in

Example 1 -2 was formed was rotated at 1 ,000 rpm, and PGME, PG MEA, a mixture of PGME and PGMEA in a weight ratio of 70:30, or ethyl lactate (abbreviated as "EL") was poured onto the carbon-comprising underlayer 1 minute.

I n addition, a substrate on which the carbon-comprising underlayer was formed was immersed in a SC-1 solution at 50°C.

The SC-1 solution was prepared beforehand as follows. A 30% aqueous H2O2 solution (1 .5) and a 1 0% aqueous N H4O H solution (3.3) were added in this order to water (47.7), and the mixture was heated to 50°C. The resulting solution was used as the SC-1 solution . The parenthesized values represent volume ratios. The 30% aqueous H2O2 solution used was one manufactured by Wako Pure Chemical I ndustries, Ltd. under the product number 081 -0421 5, and the 10% aqueous N H4O H solution used was one manufactured by Wako Pure Chemical I ndustries, Ltd . under the product number 01 3-1 7505.

These substrates were spin-dried (at 1 ,500 rpm for 1 minute) to dry the carbon-comprising underlayers. Another experiment was also conducted in which such substrates were baked (at 1 50°C for 120 seconds) to dry the carbon-comprising underlayers.

The thickness of each of the carbon-comprising underlayers exposed to the various solvents was examined by a spectroscopic film thickness measurement system (Lambda Ace VM-31 1 0).

A: No significant decrease in thickness was observed (the decrease was 1 % or less) under all of the above conditions.

B: A decrease in thickness more than 1 % was observed under any one of the above conditions.

The evaluation result is shown in Table 2.

[0056]

Example 1 -4: Evaluation of Thickness Uniformity Achieved by

Composition 1

The thickness of a carbon-comprising underlayer as obtained in Example 1 -2 was measured at a plurality of points on the underlayer by a spectroscopic film thickness measurement system (Lambda Ace VM-31 1 0), and the standard deviation of the measured values was determined . The thickness uniformity was evaluated as follows.

A: Standard deviation < 1 %

B: 1 % < standard deviation < 1 .5%

C: 1 .5% < standard deviation

The evaluation result is shown in Table 2.

[0057]

Example 1 -5: Evaluation of Filling Property of Composition 1 Composition 1 was applied to a S 1O2 wafer (not-flat substrate) shown in Figure 1 using ACT 12 (an apparatus manufactured by Tokyo Electron Limited) at 1 ,500 rpm so that the composition filled the sea regions and the gaps between the walls in the dense regions of the substrate and covered the island regions. The composition was baked at 200°C for 1 minute. In the apparatus, the baked composition was irradiated with vacuum ultraviolet (VUV) radiation having a wavelength of 1 72 nm at a dose of 500 mJ/cm² to obtain a carbon-comprising underlayer.

A section of the carbon-comprising underlayer was prepared, and gaps between walls in a dense region of the section of the underlayer were observed in a photograph taken by a SEM (S-5500, manufactured by Hitachi H igh-tech Fielding Corporation), and the filling property of composition 1 was evaluated as follows.

A: The composition successfully filled the gaps so that no gap with voids or pores was found .

B: The composition failed to sufficiently fill the gaps so that a gap with voids or pores was present.

The evaluation result is shown in Table 2.

[0058]

Example 1 -6: Evaluation of Flatness for Composition 1

To evaluate the degree of flatness achieved by composition 1 , the flatness index (the difference between the heights denoted by reference numeral 1 0 and reference numeral 1 1 in Figure 2) was measured in the SEM photograph taken in Example 1 -5 described above. The flatness index of the carbon-comprising underlayer formed from composition 1 was 1 0 nm .

The evaluation result is shown in Table 2. Preparation Examples 2-7 of Compositions 2-7

Compositions 2-7 were prepared in the same manner as in

Preparation Example 1 , except for changing the type and amount of the solid component as shown in Table 1 .

[Formula 28]

A-9550: Mixture of

High-carbon material 1 : 2,6-bis(hydroxymethyl)-p-cresol, manufactured by Tokyo Chemical I ndustry Co. , Ltd . [Formula 30

High-carbon material 2: Manufactured by Mitsubishi Gas Chemical Company, I nc.

[Formula 31 ]

High-carbon material 3: Polystyrene (weight-average molecular weight 20,000), manufactured by Merck

[Formula 32]

Photopolymerization initiator 1 : Manufactured by BASF

[Formula 33]

Photopolymerization initiator 2: Manufactured by BASF

[0060] Evaluation of Compositions 2-7

Compositions 2-7 were subjected to the same evaluation procedures as in Example 1 (Examples 1 -1 to 1 -6). The conditions and evaluation results are shown in Tables 1 and 2.

Table 1

Table 2

[0061 ]

Example 8: Evaluation of Etching Rate

The following experiment was conducted to examine the effect of addition of a high-carbon material to the carbon-comprising underlayer- forming composition of the present invention .

A carbon-comprising underlayer formed from composition 1 according to the procedure described in Example 1 -2 was dry-etched by an etching apparatus (N E-5000N , manufactured by U LVAC, I nc.). O2 and CF₄ were used as dry etching gases. In Example 8, the amount of decrease in thickness per unit time during dry etching was measured.

[0062]

Examples 9 to 1 3: Evaluation of Etching Rate

Compositions 3 to 7 listed in Table 3 were dry-etched , and the relative etching rate was calculated with respect to the amount of decrease in thickness per unit time during dry etching as determined in Example 8.

The evaluation results are shown in Table 3.

It was confirmed that addition of a high-carbon material to the carbon-comprising underlayer-forming composition provides an increase in etching resistance.

Table 3

Composition O2 etching CF₄ etching

Example 8 Composition 1 1 .00 1 .00

Example 9 Composition 3 0.98 0.97

Example 1 0 Composition 4 0.72 0.70

Example 1 1 Composition 5 0.75 0.73

Example 12 Composition 6 0.98 0.97

Example 1 3 Composition 7 0.73 0.71 [Reference Signs List]

[0063]

1 . Island region of substrate

2. Sea region of substrate

3. Dense region of substrate

4. Bottom surface of substrate

5. Lower part of substrate

6. Top part of substrate

7. Height between island region and sea region

8. Height between dense region and sea region

9. Formed planarizing coating

1 0. Height between top part of island region and bottom surface of substrate

1 1 . Height between top part of dense region and bottom surface of substrate

Claims

Patent Claims

1 . A carbon-comprising underlayer-forming composition , comprising:

an acrylate derivative represented by formula (I ):

[Formula 1 ]

(I ).

wherein

X is a C2-40 carbon-comprising skeleton ,

Ri is hydrogen or Ci _-4 alkyl, and

n is 2, 3, 4, 5, 6, 7, or 8; and

one or more organic solvents.

The carbon-comprising underlayer-forming composition according to claim 1 , wherein in the acrylate derivative represented by formula (I ), X is linear or branched C2-15 alkylene, linear or branched C2-15 alkoxylene, C20-40 arylene, a Ce-ι ο saturated hydrocarbon ring, hydroxy, or a composite group thereof, and Ri is hydrogen or methyl .

3. The carbon-comprising underlayer-forming composition according to claim 1 or 2, wherein the one or more organic solvents comprise either a hydroxyl group or an ester-derivative group represented by formula (I I ), or both a hydroxyl group and an ester-derivative group represented by formula (I I):

[Formula 2]

wherein

R2 is a direct bond to a moiety of the organic solvent molecule other than the moiety of formula (I I ), a methyl , or carbon linked to R₄ to form a saturated ring,

R3 is hydrogen , or methoxy-substituted or unsubstituted C1 -3 alkyl, and R₄ is a methyl, or carbon linked to R2 to form a saturated ring.

The carbon-comprising underlayer-forming composition according to claim 3, wherein the one or more organic solvents comprise both a hydroxyl group and an ester-derivative group represented by formula (I I ), and the molar ratio between the hydroxyl group and the ester-derivative group is 23:77 to 77:23.

5. The carbon-comprising underlayer-forming composition according to any one of claims 1 to 4, wherein the composition further comprises a high- carbon material, and the elements constituting the material satisfy formula (I I I):

1 .5 < {total number of atoms/(number of C - number of O)} < 3.5 (I I I ), when the high-carbon material is a monomer, the total number of atoms is the number of the atoms in the whole monomer molecule, or when the high- carbon material is a polymer, the total number of atoms is the number of the atoms in one repeating unit,

the number of C is the number of carbon atoms in the total number of atoms, the number of O is the number of oxygen atoms in the total number of atoms, and

the number of C is greater than the number of O. 6. The carbon-comprising underlayer-forming composition according to

claim 5, wherein the high-carbon material is represented by formula (IV), (V), or (VI ):

[Formula 3]

(IV),

wherein

An is a direct bond , Ci -6 alkyl , Ce-12 cycloalkyl , or Ce-14 aryl,

Ar2 is Ci -6 alkyl, Ce-12 cycloalkyl , or Ce-14 aryl,

R5 and R6 are each independently C1 -6 alkyl, hydroxy, halogen , or cyano, R7 is hydrogen , C1 -6 alkyl, or Ce-14 aryl,

when Ar2 is C 1 -6 alkyl or Ce-14 aryl and R7 is C 1 -6 alkyl or Ce-14 aryl, Ar2 and R7 are optionally linked to each other to form a hydrocarbon ring, r and s are each independently 0, 1 , 2, 3, 4, or 5,

at least one of the Ci , C2, and C3 rings each surrounded by the broken line is an aromatic hydrocarbon ring fused with the adjacent aromatic hydrocarbon ring Pi , and

at least one of the C₄, C5, and C6 rings each surrounded by the broken line is an aromatic hydrocarbon ring fused with the adjacent aromatic hydrocarbon ring P2;

[Formula 4]

wherein

Rs is hydrogen , C1-6 alkyl, halogen, or cyano,

R9 is C1-6 alkyl, halogen , or cyano, and

p is 0, 1 , 2, 3, 4, or 5;

[Formula 5]

wherein the ring P is phenyl having hydroxyl ,

Y is C1 -6 alkyl, Ce-14 aryl, C6-12 cycloalkyl , C7-20 aralkyl, C7-20 alkyl-substituted aralkyl, C7-20 cycloalkyl-substituted alkylcycloalkyl , or a direct bond connecting the two rings P to each other,

R10 is hydrogen , methyl, ethyl, phenyl, methylol , C1 -3 alkoxymethyl , or C6-12 cycloalkyl,

R11 is hydrogen or C1 -3 alkyl,

m is 1 , 2, 3, or 4, and

m' is 0 or 1 .

7. The carbon-comprising underlayer-forming composition according to any one of claims 1 to 6, wherein the composition further comprises a surfactant, a photopolymerization initiator, a crosslinking agent, an acid generator, a radical generator, an agent for enhancing the adhesion to substrates, or a mixture thereof.

8. The carbon-comprising underlayer-forming composition according to any one of claims 1 to 7, wherein the composition comprises a

photopolymerization initiator in a concentration of 0-1 ,000 ppm .

9. The carbon-comprising underlayer-forming composition according to any one of claims 1 to 8, wherein the composition comprises a crosslinking agent in a concentration of 0-1 ,000 ppm . 1 0. The carbon-comprising underlayer-forming composition according to any one of claims 1 to 9, wherein the composition comprises an acid generator in a concentration of 0-500 ppm and/or comprises a radical generator in a concentration of 0-500 ppm .

1 1 . A planarizing coating-forming composition consisting of a carbon- comprising underlayer-forming composition according to any one of claims 1 to 1 0.

12. A method for manufacturing a carbon-comprising underlayer,

comprising:

applying a carbon-comprising underlayer-forming composition according to any one of claims 1 to 1 0 onto a substrate; and

curing the carbon-comprising underlayer-forming composition to form a carbon-comprising underlayer.

1 3. The method for manufacturing a carbon-comprising underlayer

according to claim 12, wherein the conditions for curing the carbon- comprising underlayer-forming composition comprise irradiation with ultraviolet radiations having a wavelength of 1 0-380 nm .

14. The method for manufacturing a carbon-comprising underlayer

according to claim 1 3, wherein the wavelength of the ultraviolet radiation is 1 0-200 nm .

1 5. The method according to any one of claims 12 to 14, wherein

the substrate is an not-flat substrate,

the carbon-comprising underlayer-forming composition consists of a planarizing coating-forming composition, and

the carbon-comprising underlayer manufactured is a planarizing coating.

1 6. The method for manufacturing a planarizing coatingcomprising according to claim 1 5, wherein the not-flat substrate is a silicon- comprising substrate with a difference in height between the top part and the lower part of 20-1 ,000 nm .

1 7. A method for manufacturing a device, comprising:

forming a carbon-comprising underlayer by the method according to any one of claims 12 to 14;

curing the photoresist composition to form a photoresist layer;

exposing the substrate coated with the photoresist layer;

developing the exposed substrate to form a resist pattern ;

etching the carbon-comprising underlayer or the interlayer through the resist pattern as a mask to pattern the coating; and

processing the substrate by etching it through the patterned carbon- comprising underlayer or the patterned interlayer as a mask. 1 8. The method for manufacturing a device according to claim 1 7, further comprising forming wiring in the processed substrate.