WO2023063237A1

WO2023063237A1 - Underlayer film-forming composition

Info

Publication number: WO2023063237A1
Application number: PCT/JP2022/037545
Authority: WO
Inventors: 潤水野; 洋平アラリック河合; 登喜雄西田; 勇樹遠藤; 高広岸岡
Original assignee: 学校法人早稲田大学; 日産化学株式会社
Priority date: 2021-10-11
Filing date: 2022-10-07
Publication date: 2023-04-20
Also published as: TW202328223A

Abstract

Provided is an underlayer film-forming composition used when an underlayer film material is applied over a film to be processed of a substrate having the film to be processed, an organic film is formed using a pattern-forming material, and after patterning, the underlayer film and the film to be processed are processed using a composite film obtained by impregnating the organic film with a metal compound as a mask pattern, wherein impregnation of the metal compound is minimized when the organic film is impregnated with the metal compound. The underlayer film-forming composition is used to form a composite film mask pattern obtained by impregnating a patterned organic film with a metal compound on a semiconductor substrate, and the composition includes a polymer containing a hydroxy group, and imparts an underlayer film containing 22 mass% or less of a carbonyl group.

Description

Underlayer film-forming composition

Embodiments of the present invention relate to resist underlayer film-forming materials, resist underlayer film-forming compositions, pattern forming methods, and semiconductor device manufacturing methods.

Conventionally, microfabrication by lithography using a photoresist composition has been performed in the manufacture of semiconductor devices. In the microfabrication, a thin film of a photoresist composition is formed on a semiconductor substrate such as a silicon wafer, exposed to actinic rays such as ultraviolet rays through a mask pattern on which a device pattern is drawn, and developed. This is a processing method in which the substrate is etched using the obtained photoresist pattern as a protective film to form fine unevenness corresponding to the pattern on the substrate surface. In recent years, semiconductor devices have become highly integrated, and active rays used include i-rays (wavelength 365 nm), KrF excimer lasers (wavelength 248 nm), ArF excimer lasers (wavelength 193 nm), and extreme ultraviolet rays (EUV) (13.5 nm). ) is shortened. In forming a resist pattern with miniaturization, the contact area between the resist pattern and the underlying substrate becomes smaller, so that the aspect ratio of the resist pattern (height of the resist pattern/line width of the resist pattern) increases. It is feared that the collapse of Therefore, the film thickness of the resist tends to be thin. Therefore, the resist underlayer film or the antireflection film that contacts the resist pattern is required to have high adhesion to the resist pattern so as not to cause the collapse.

On the other hand, in the manufacturing process of semiconductor devices, there is an increasing demand for technology that forms patterns with a high aspect ratio. Since the mask pattern used in such a process is exposed to etching gas for a long time, high etching resistance is required. Therefore, after forming and patterning an organic film using a pattern forming material containing a specific polymer, a mask pattern having high etching resistance can be obtained by using a composite film obtained by impregnating the organic film with a metal compound as a mask pattern. known to be obtained. Impregnation of an organic film with a metal compound is called "metallization." Specifically, metallization can be carried out by binding a metal compound to a site of an organic film that has a site to which a metal compound can be bonded.

Patent Document 1 discloses a film forming step of forming a pattern forming material film containing a pattern forming material containing a specific polymer on a substrate, and a contacting step of contacting the pattern forming material film with a metal compound containing a metal element. A patterning method is disclosed that includes:

The mask pattern is created using the pattern forming material (resist) described in Patent Document 1. Under the resist, a resist underlayer film is used for forming a good resist pattern. In a specific process, a resist underlayer film material that is metallized as little as possible may be required in the metallization process.

Japanese Patent Application Laid-Open No. 2019-53228

The problem to be solved by the present invention is to apply a lower layer film material on the film to be processed of a substrate having the film to be processed, form an organic film using a pattern forming material, and pattern the organic film. An underlayer film material used when processing the underlayer film and the film to be processed using a composite film impregnated with a metal compound as a mask pattern, wherein the impregnation of the metal compound occurs when the organic film is impregnated with the metal compound. It is an object of the present invention to provide a suppressed underlayer film material.

The present invention includes the following.
[1]
An underlayer film forming composition used for forming a composite film mask pattern in which a patterned organic film is impregnated with a metal compound on a semiconductor substrate, the composition comprising a polymer containing a hydroxy group and containing no more than 22% by weight. An underlayer film-forming composition that provides an underlayer film containing a carbonyl group of
[2]
The polymer has the following formula (I):

[in the formula (I),
R ₁ represents a hydrogen atom or a methyl group,
L ₁ represents a single bond, -COO- group, -CONH- group, or a linear or branched alkylene group having 1 to 5 carbon atoms,
A represents a linear or branched hydroxyalkyl group having 1 to 20 carbon atoms. ]
The underlayer film-forming composition according to [1], comprising a repeating unit structure represented by:
[3]
The underlayer film-forming composition according to [2], wherein the polymer contains 20 mol % to 90 mol % of the repeating unit structure represented by the formula (I) with respect to the entire polymer.
[4]
The polymer has the following formula (II):

[in the formula (II),
T ¹ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms which may be substituted with a halogeno group;
L ² represents a single bond, -COO- group, -CONH- group, or a linear or branched alkylene group having 1 to 5 carbon atoms,
R ¹ is substituted with a halogeno group, a carboxy group, a nitro group, a cyano group, a methylenedioxy group, an acetoxy group, a methylthio group, an alkoxy group having 1 to 9 carbon atoms, or an alkyl group having 1 to 3 carbon atoms; represents an amino group which may be substituted, or an alkyl group having 1 to 10 carbon atoms which may be substituted with a hydroxy group or a halogeno group;
r1 represents an integer of 0 to 3,
n1 represents an integer of 0 to 2,
a represents an integer of 0 to 6; ]
The underlayer film-forming composition according to [1], comprising a repeating unit structure represented by:
[5]
The underlayer film-forming composition according to [4], wherein the polymer contains 10 mol % to 100 mol % of the repeating unit structure represented by the formula (II) with respect to the entire polymer.
[6]
The underlayer film-forming composition according to any one of [1] to [5], wherein the metal compound contains aluminum.
[7]
The underlayer film-forming composition according to any one of [1] to [6], further comprising a solvent.
[8]
The underlayer film-forming composition according to any one of [1] to [7], further comprising a cross-linking agent and/or an acid catalyst.
[9]
An underlayer film characterized by being a baked product of a coating film comprising the underlayer film-forming composition according to any one of [1] to [8].
[10]
An underlayer film used for forming a composite film mask pattern on a semiconductor substrate, in which a patterned organic film is impregnated with a metal compound, the underlayer film containing 22% by weight or less of carbonyl groups.
[11]
The Underlayer film of [10], wherein the metal compound comprises aluminum.
[12]
A step of applying the underlayer film-forming composition according to any one of [1] to [8] onto a semiconductor substrate and baking the composition to form an underlayer film;
forming a patterned organic film on the underlayer film, then exposing and developing to form an organic film pattern;
A method for manufacturing a substrate with an organic film pattern for use in manufacturing a semiconductor, comprising the step of impregnating the organic film pattern with a metal compound.
[13]
The method for producing a substrate according to [12], wherein the step of impregnating the organic film pattern with the metal compound is performed so that the amount of diffusion of the metal at a depth of 30 nm from the surface of the lower layer film is 10 atm % or less.
[14]
The method for producing a substrate according to [12] or [13], wherein the metal compound contains aluminum.
[15]
A step of forming an underlayer film using the underlayer film-forming composition according to any one of [1] to [8] on a semiconductor substrate which may have an inorganic film formed thereon;
forming an organic film pattern on the underlayer film;
impregnating the organic film pattern with a metal compound;
A method of manufacturing a semiconductor device, comprising a step of etching the inorganic film or the semiconductor substrate using the organic film pattern impregnated with the metal as a mask.
[16]
The method for manufacturing a semiconductor device according to [15], wherein the step of impregnating the organic film pattern with the metal compound is performed so that the diffusion amount of the metal at a depth of 30 nm from the surface of the lower layer film is 10 atm % or less.
[17]
The method of manufacturing a semiconductor device according to [15] or [16], wherein the metal compound contains aluminum.
[18]
A composite film mask pattern obtained by impregnating an organic film with a metal compound and patterning an underlayer film-forming composition comprising a polymer containing a hydroxyl group and providing an underlayer film containing 22% by mass or less of a carbonyl group is formed on a semiconductor substrate. Use for molding.
[19]
The polymer has the following formula (I):

[in the formula (I),
R ₁ represents a hydrogen atom or a methyl group,
L ₁ represents a single bond, -COO- group, -CONH- group, or a linear or branched alkylene group having 1 to 5 carbon atoms,
A represents a linear or branched hydroxyalkyl group having 1 to 20 carbon atoms. ]
The use according to [18], comprising a repeating unit structure represented by
[20]
The polymer has the following formula (II):

[in the formula (II),
T ¹ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms which may be substituted with a halogeno group;
L ² represents a single bond, -COO- group, -CONH- group, or a linear or branched alkylene group having 1 to 5 carbon atoms,
R ¹ is substituted with a halogeno group, a carboxy group, a nitro group, a cyano group, a methylenedioxy group, an acetoxy group, a methylthio group, an alkoxy group having 1 to 9 carbon atoms, or an alkyl group having 1 to 3 carbon atoms; represents an amino group which may be substituted, or an alkyl group having 1 to 10 carbon atoms which may be substituted with a hydroxy group or a halogeno group;
r1 represents an integer of 0 to 3,
n1 represents an integer of 0 to 2,
a represents an integer of 0 to 6; ]
The use according to [18], comprising a repeating unit structure represented by
[21]
The use according to any one of [18] to [20], wherein the organic film impregnated with the metal compound has a metal diffusion amount of 10 atm % or less at a depth of 30 nm from the surface of the underlying film.
[22]
Use according to any one of [18] to [21], wherein the metal compound comprises aluminum.

By applying the composition for forming a resist underlayer film according to the present invention to a lithography process, an organic film is formed using a pattern forming material, patterned, and then a composite film is produced by impregnating the organic film with a metal compound. In this case, impregnation of the metal compound into the resist underlayer film can be suppressed. Therefore, the underlying film and the film to be processed can be processed using the composite film as a mask pattern.

(Underlayer film-forming composition)
An underlayer film-forming composition according to the present invention is an underlayer film-forming composition used for forming a composite film mask pattern on a semiconductor substrate, in which a patterned organic film is impregnated with a metal compound, wherein and provides an underlayer film containing 22% by mass or less of carbonyl groups.

There is no particular limitation on the polymer containing hydroxy groups. Although the hydroxy group may be contained at the polymer terminal, it is preferably contained in the main chain or side chain. Hydroxy groups are preferably non-phenolic.
When the unit structure constituting the polymer is one type (in the case of a homopolymer), the unit structure may contain a hydroxy group, and when the unit structure constituting the polymer is two or more types (in the case of a copolymer), At least one unit structure may contain a hydroxy group. The number of hydroxy groups per unit structure is not particularly limited as long as it is 1 or more, but is preferably 5 or less, 4 or less, 3 or less, or 2 or less.

The polymer preferably contains a repeating unit structure represented by the following formula (I).

[in the formula (I),
R ₁ represents a hydrogen atom or a methyl group,
L ₁ represents a single bond, -COO- group, -CONH- group, or a linear or branched alkylene group having 1 to 5 carbon atoms,
A represents a linear or branched hydroxyalkyl group having 1 to 20 carbon atoms. ]

The polymer preferably contains a repeating unit structure represented by the following formula (II).

[in the formula (II),
T ¹ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms which may be substituted with a halogeno group;
L ² represents a single bond, -COO- group, -CONH- group, or a linear or branched alkylene group having 1 to 5 carbon atoms,
R ¹ is substituted with a halogeno group, a carboxy group, a nitro group, a cyano group, a methylenedioxy group, an acetoxy group, a methylthio group, an alkoxy group having 1 to 9 carbon atoms, or an alkyl group having 1 to 3 carbon atoms; represents an amino group which may be substituted, or an alkyl group having 1 to 10 carbon atoms which may be substituted with a hydroxy group or a halogeno group;
r1 represents an integer of 0 to 3,
n1 represents an integer of 0 to 2,
a represents an integer of 0 to 6; ]

Examples of alkyl groups having 1 to 10 carbon atoms include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, s-butyl group, t-butyl group, n-pentyl group, 1-methyl-n-butyl group, 2-methyl-n-butyl group, 3-methyl-n-butyl group, 1,1-dimethyl-n-propyl group, 1,2-dimethyl-n -propyl group, 2,2-dimethyl-n-propyl group, 1-ethyl-n-propyl group, n-hexyl group, 1-methyl-n-pentyl group, 2-methyl-n-pentyl group, 3-methyl -n-pentyl group, 4-methyl-n-pentyl group, 1,1-dimethyl-n-butyl group, 1,2-dimethyl-n-butyl group, 1,3-dimethyl-n-butyl group, 2, 2-dimethyl-n-butyl group, 2,3-dimethyl-n-butyl group, 3,3-dimethyl-n-butyl group, 1-ethyl-n-butyl group, 2-ethyl-n-butyl group, 1 , 1,2-trimethyl-n-propyl group, 1,2,2-trimethyl-n-propyl group, 1-ethyl-1-methyl-n-propyl group, 1-ethyl-2-methyl-n-propyl group etc.

It may also be a cyclic alkyl group, for example, cyclopropyl group, cyclobutyl group, 1-methyl-cyclopropyl group, 2-methyl-cyclopropyl group, cyclopentyl group, 1-methyl-cyclobutyl group, 2-methyl- cyclobutyl group, 3-methyl-cyclobutyl group, 1,2-dimethyl-cyclopropyl group, 2,3-dimethyl-cyclopropyl group, 1-ethyl-cyclopropyl group, 2-ethyl-cyclopropyl group, cyclohexyl group, 1 -methyl-cyclopentyl group, 2-methyl-cyclopentyl group, 3-methyl-cyclopentyl group, 1-ethyl-cyclobutyl group, 2-ethyl-cyclobutyl group, 3-ethyl-cyclobutyl group, 1,2-dimethyl-cyclobutyl group, 1,3-dimethyl-cyclobutyl group, 2,2-dimethyl-cyclobutyl group, 2,3-dimethyl-cyclobutyl group, 2,4-dimethyl-cyclobutyl group, 3,3-dimethyl-cyclobutyl group, 1-n-propyl -cyclopropyl group, 2-n-propyl-cyclopropyl group, 1-i-propyl-cyclopropyl group, 2-i-propyl-cyclopropyl group, 1,2,2-trimethyl-cyclopropyl group, 1,2 ,3-trimethyl-cyclopropyl group, 2,2,3-trimethyl-cyclopropyl group, 1-ethyl-2-methyl-cyclopropyl group, 2-ethyl-1-methyl-cyclopropyl group, 2-ethyl-2 -methyl-cyclopropyl group and 2-ethyl-3-methyl-cyclopropyl group.

Examples of the linear or branched alkylene group having 1 to 5 carbon atoms include methylene group, ethylene group, n-propylene group, isopropylene group, cyclopropylene group, n-butylene group, isobutylene group and s-butylene. group, t-butylene group, cyclobutylene group, 1-methyl-cyclopropylene group, 2-methyl-cyclopropylene group, n-pentylene group, 1-methyl-n-butylene group, 2-methyl-n-butylene group, 3-methyl-n-butylene group, 1,1-dimethyl-n-propylene group, 1,2-dimethyl-n-propylene group, 2,2-dimethyl-n-propylene, 1-ethyl-n-propylene group, cyclopentylene group, 1-methyl-cyclobutylene group, 2-methyl-cyclobutylene group, 3-methyl-cyclobutylene group, 1,2-dimethyl-cyclopropylene group, 2,3-dimethyl-cyclopropylene group, 1 -ethyl-cyclopropylene group, 2-ethyl-cyclopropylene group and the like.

　Halogeno groups include fluorine, chlorine, bromine, and iodine.

Examples of the alkyl group having 1 to 10 carbon atoms substituted with a halogeno group include the alkyl groups having 1 to 10 carbon atoms exemplified above substituted with at least one of the halogeno groups exemplified above.

The alkyl group having 1 to 10 carbon atoms substituted with a hydroxy group includes the above-exemplified alkyl groups having 1 to 10 carbon atoms substituted with at least one hydroxy group.

Examples of linear or branched hydroxyalkyl groups having 1 to 20 carbon atoms include the above-exemplified alkyl groups having 1 to 10 carbon atoms substituted with at least one hydroxy group, and at least one hydroxy group. undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl and eicosyl groups substituted with .

As the alkoxy group having 1 to 9 carbon atoms, among the alkyl groups exemplified above, a group in which an etheric oxygen atom (—O—) is bonded to the terminal carbon atom of an alkyl group having 1 to 9 carbon atoms. mentioned. Examples of such alkoxy groups include methoxy, ethoxy, n-propoxy, i-propoxy, cyclopropoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy, cyclo butoxy group, 1-methyl-cyclopropoxy group, 2-methyl-cyclopropoxy group, n-pentoxy group, 1-methyl-n-butoxy group, 2-methyl-n-butoxy group, 3-methyl-n-butoxy group , 1,1-dimethyl-n-propoxy group, 1,2-dimethyl-n-propoxy group, 2,2-dimethyl-n-propoxy group, 1-ethyl-n-propoxy group, 1,1-diethyl-n -propoxy group, cyclopentoxy group, 1-methyl-cyclobutoxy group, 2-methyl-cyclobutoxy group, 3-methyl-cyclobutoxy group, 1,2-dimethyl-cyclopropoxy group, 2,3-dimethyl-cyclo A propoxy group, a 1-ethyl-cyclopropoxy group, a 2-ethyl-cyclopropoxy group and the like can be mentioned.

Examples of the amino group optionally substituted with an alkyl group having 1 to 3 carbon atoms include methylamino group, dimethylamino group, ethylamino group, methylethylamino group and propylamino group.

When the polymer contains the repeating unit structure represented by formula (I), the content is preferably 20 mol% or more, 30 mol% or more, 40 mol% or more, or 50 mol% or more of the entire polymer. 60 mol % or less, 70 mol % or less, 80 mol % or less, or 90 mol % or less.
When the polymer contains a repeating unit structure represented by formula (II), the content is preferably 10 mol% or more, 20 mol% or more, 30 mol% or more, 40 mol% or more, or It is 50 mol % or more and 60 mol % or less, 70 mol % or less, 80 mol % or less, 90 mol % or less, or 100 mol % or less.

Some examples of the repeating unit structure are as follows, but are not limited to these.

The underlayer film-forming composition according to the present invention can contain a repeating unit structure other than the above repeating unit structure. Such repeating unit structures include, for example, styrene, 1-vinylnaphthalene, 2-vinylnaphthalene, 9-vinylanthracene, vinylbenzophenone, hydroxystyrene, (meth)acrylic acid, methyl (meth)acrylate, (meth) Examples include unit structures derived from benzyl acrylate, methyl 4-vinylbenzoate, 4-vinylbenzoic acid, and the like.
The content of these components is preferably 50 mol % or less, 25 mol % or less, 10 mol % or less, 5 mol % or less, or 1 mol % or less with respect to the entire polymer.

Some examples of the unit structure that can be copolymerized with the repeating unit structure are as follows, but are not limited to these.

The weight-average molecular weight (Mw) of the hydroxyl group-containing polymer contained in the underlayer film-forming composition according to the present invention can be measured by gel permeation chromatography (GPC), and is preferably 1,000 or more, or 5,000 or more. 000 or more, preferably 1,000,000 or less, or 20,000 or less.

The underlayer film-forming composition according to the present invention can contain a solvent, a cross-linking agent, an acid catalyst, and other components within a range that does not impair the effects of the present invention.

(solvent)
The solvent used in the composition for forming an underlayer film according to the present invention is not particularly limited as long as it is a solvent capable of uniformly dissolving the components such as the above polymers that are solid at room temperature. The organic solvents used are preferred. Specifically, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl Ether acetate, propylene glycol propyl ether acetate, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, cycloheptanone, 4-methyl-2-pentanol, methyl 2-hydroxyisobutyrate, 2-hydroxyisobutyric acid Ethyl, ethyl ethoxyacetate, 2-hydroxyethyl acetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl acetate , butyl acetate, ethyl lactate, butyl lactate, 2-heptanone, methoxycyclopentane, anisole, γ-butyrolactone, N-methylpyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide. These solvents can be used alone or in combination of two or more.

Among these solvents, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl lactate, butyl lactate, and cyclohexanone are preferred. Propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate are particularly preferred.

(crosslinking agent)
The cross-linking agent contained as an optional component in the underlayer film-forming composition according to the present invention is not particularly limited. (tetramethoxymethylglycoluril) (POWDERLINK® 1174), 1,3,4,6-tetrakis(butoxymethyl)glycoluril, 1,3,4,6-tetrakis(hydroxymethyl)glycoluril, 1, 3-bis(hydroxymethyl)urea, 1,1,3,3-tetrakis(butoxymethyl)urea and 1,1,3,3-tetrakis(methoxymethyl)urea.

In addition, the cross-linking agent of the present application is a nitrogen-containing compound having 2 to 6 substituents per molecule represented by the following formula (1d) that binds to a nitrogen atom, as described in International Publication No. 2017/187969. There may be.

(In formula (1d), R ₁ represents a methyl group or an ethyl group.)
The nitrogen-containing compound having 2 to 6 substituents represented by the formula (1d) in one molecule may be a glycoluril derivative represented by the following formula (1E).

(In formula (1E), four R _1s each independently represent a methyl group or an ethyl group, and R ₂ and R ₃ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group. .)
Examples of the glycoluril derivative represented by the formula (1E) include compounds represented by the following formulas (1E-1) to (1E-6).

The nitrogen-containing compound having 2 to 6 substituents represented by the formula (1d) in one molecule has 2 to 6 substituents in the molecule represented by the following formula (2d) bonded to the nitrogen atom. It can be obtained by reacting a nitrogen-containing compound with at least one compound represented by the following formula (3d).

(In formulas (2d) and (3d), R ₁ represents a methyl group or an ethyl group, and R ₄ represents an alkyl group having 1 to 4 carbon atoms.)
The glycoluril derivative represented by the formula (1E) is obtained by reacting a glycoluril derivative represented by the following formula (2E) with at least one compound represented by the formula (3d).

A nitrogen-containing compound having 2 to 6 substituents represented by the above formula (2d) in one molecule is, for example, a glycoluril derivative represented by the following formula (2E).

(In formula (2E), R ₂ and R ₃ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group, and R ₄ each independently represent an alkyl group having 1 to 4 carbon atoms. represents.)
Examples of the glycoluril derivative represented by the formula (2E) include compounds represented by the following formulas (2E-1) to (2E-4). Furthermore, examples of the compound represented by the formula (3d) include compounds represented by the following formulas (3d-1) and (3d-2).

With respect to the nitrogen-containing compound having 2 to 6 substituents represented by the following formula (1d) in one molecule that binds to the nitrogen atom, the full disclosure of WO2017/187969 is incorporated herein by reference. .

A cross-linking agent having high heat resistance can be used as the cross-linking agent. As a highly heat-resistant cross-linking agent, a compound containing a cross-linking substituent having an aromatic ring (eg, benzene ring, naphthalene ring) in the molecule can be used.
Examples of such compounds include compounds having a partial structure of the following formula (5-1) and polymers or oligomers having repeating units of the following formula (5-2).

R ¹¹ , R ¹² , R ¹³ and R ¹⁴ are hydrogen atoms or alkyl groups having 1 to 10 carbon atoms, and specific examples of these alkyl groups are as described above.
m1 is 1≤m1≤6-m2, m2 is 1≤m2≤5, m3 is 1≤m3≤4-m2, and m4 is 1≤m4≤3.
Compounds, polymers and oligomers of formulas (5-1) and (5-2) are exemplified below.

The above compounds are available as products of Asahi Organic Chemical Industry Co., Ltd. and Honshu Chemical Industry Co., Ltd. For example, among the above crosslinking agents, the compound of formula (6-22) is available from Asahi Organic Chemicals Industry Co., Ltd. under the trade name TMOM-BP.

When the cross-linking agent is used, the content of the cross-linking agent is, for example, 1% to 50% by mass, preferably 5% to 30% by mass, relative to the polymer.

The acid catalyst contained as an optional component in the underlayer film-forming composition according to the present invention is not particularly limited. Sulfonate, p-toluenesulfonic acid, p-hydroxybenzenesulfonic acid, trifluoromethanesulfonic acid, salicylic acid, camphorsulfonic acid, 5-sulfosalicylic acid, chlorobenzenesulfonic acid, methyl 4-phenolsulfonate, benzenesulfonic acid, naphthalenesulfonic acid , citric acid, sulfonic acid compounds and carboxylic acid compounds such as benzoic acid, and K-PURE (registered trademark) TAG2689, TAG2690, TAG2678, CXC-1614 (above), which are quaternary ammonium salts of trifluoromethanesulfonic acid , King Industries), 2,4,4,6-tetrabromocyclohexadienone, benzoin tosylate, 2-nitrobenzyl tosylate, and other thermal acid generators such as organic sulfonic acid alkyl esters. These acid catalysts may be contained singly or in combination of two or more. Also, among the acid catalysts, pyridinium p-hydroxybenzenesulfonate is preferred.

A catalyst ion exchange resin can be used to prevent unreacted acids, catalysts, and inactivated catalysts from remaining in the reaction system. For example, a sulfonic acid-type strongly acidic ion-exchange resin can be used as the catalyst ion-exchange resin.

The underlayer film-forming composition according to the present invention can contain the acid catalyst in an amount of, for example, 1% to 30% by mass, preferably 5% to 15% by mass, based on the content of the crosslinking agent.

(other ingredients)
A surfactant may be further added to the underlayer film-forming composition according to the present invention in order to prevent pinholes, striations, and the like from occurring and to further improve coating properties against surface unevenness. Examples of surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene oleyl ether, polyoxyethylene octylphenol ether, and polyoxyethylene nonylphenol ether. Polyoxyethylene alkyl allyl ethers such as polyoxyethylene/polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, sorbitan tristearate, etc. sorbitan fatty acid esters, polyoxyethylene sorbitan such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate Nonionic surfactants such as fatty acid esters, F-top EF301, EF303, EF352 (manufactured by Tochem Products Co., Ltd., trade names), Megafac F171, F173, R-30 (manufactured by Dainippon Ink Co., Ltd., commercial products name), Florard FC430, FC431 (manufactured by Sumitomo 3M Co., Ltd., trade name), Asahiguard AG710, Surflon S-382, SC101, SC102, SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd., trade name), etc. and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.). The blending amount of these surfactants is usually 2.0% by mass or less, preferably 1.0% by mass or less, based on the total solid content of the underlayer film-forming composition according to the present invention. These surfactants may be added singly or in combination of two or more.

The solid content contained in the underlayer film-forming composition according to the present invention, that is, the components excluding the solvent is, for example, 0.01% by mass to 10% by mass.

The underlayer film-forming composition according to the present invention is characterized by providing an underlayer film containing 22% by mass or less of carbonyl groups. For example, the underlayer film-forming composition according to the present invention is applied by a suitable coating method onto a substrate used for manufacturing a semiconductor device, and then baked to form an underlayer film. At this time, the firing conditions are appropriately selected from a firing temperature of 80° C. to 250° C. and a firing time of 0.3 to 60 minutes. The firing temperature is preferably 150°C to 250°C, 180°C to 220°C, or 200°C to 210°C, and the firing time is preferably 0.5 to 20 minutes, 1 to 10 minutes, or 2 to 8 minutes. is. Here, the thickness of the lower layer film to be formed is, for example, 10 to 1,000 nm.

The composition for forming an underlayer film according to the present invention is characterized by being used to form a composite film mask pattern in which a patterned organic film is impregnated with a metal compound on a semiconductor substrate. The patterned organic film is not particularly limited, but is typically a photoresist layer in microfabrication by lithography using a photoresist composition in the manufacture of semiconductor devices.

As the metal compound, any metal compound used in the CVD method or the atomic layer deposition (ALD) method can be used without particular limitation.

Metals contained in metal compounds include aluminum, titanium, tungsten, vanadium, hafnium, zirconium, tantalum, and molybdenum. Preferably, the metal compound contains aluminum.

The metal compound impregnated in the organic film may then be appropriately treated and used as a mask pattern. For example, in the case of TMA, it may be converted to aluminum hydroxide, aluminum oxide, or the like by oxidation treatment after bonding to an organic film. The oxidation treatment is usually performed using an oxidizing agent such as water, ozone, or oxygen plasma, but it can also be performed using moisture in the atmosphere without any intentional operation.

(Method for manufacturing organic film patterned substrate, method for manufacturing semiconductor device)
The method for manufacturing a substrate with an organic film pattern used for manufacturing a semiconductor according to the present invention comprises:
a step of applying the underlayer film-forming composition onto a semiconductor substrate and baking it to form an underlayer film;
forming a patterned organic film on the underlayer film, then exposing and developing to form an organic film pattern;
Next, a step of impregnating the organic film pattern with a metal compound is included.

Semiconductor substrates also include semiconductor substrates having inorganic films formed on their surfaces, such as silicon wafer substrates, silicon/silicon dioxide coated substrates, silicon nitride substrates, glass substrates, ITO substrates, polyimide substrates, and low dielectric substrates. and low-k material coated substrates. The underlayer film-forming composition according to the present invention is applied onto such a substrate used in the manufacture of semiconductor devices by a suitable coating method such as a spinner or a coater, and then baked to obtain the substrate according to the present invention. forming an underlayer film; The firing conditions are appropriately selected from a firing temperature of 80° C. to 250° C. and a firing time of 0.3 to 60 minutes. The thickness of the underlayer film to be formed is, for example, 10 to 1,000 nm, 20 to 500 nm, 30 to 300 nm, or 50 to 200 nm.
The Underlayer film according to the present invention is characterized by containing no more than 22% by weight of carbonyl groups.

Next, a photoresist layer is formed on the underlayer film according to the present invention. The photoresist formed by coating and baking on the underlayer film according to the present invention by a method known per se is not particularly limited as long as it is sensitive to the light used for exposure. Both negative and positive photoresists can be used. positive photoresist composed of novolac resin and 1,2-naphthoquinonediazide sulfonic acid ester; A chemically amplified photoresist comprising a low-molecular compound that decomposes to increase the alkali dissolution rate of the photoresist, an alkali-soluble binder, and a photoacid generator, and a binder having a group that decomposes with an acid to increase the alkali dissolution rate. There are chemically amplified photoresists composed of low-molecular-weight compounds and photoacid generators that are decomposed by acid to increase the rate of alkali dissolution of photoresists, and resists containing metal elements. Examples include V146G and AR2772 (trade names) manufactured by JSR Corporation, APEX-E (trade name) manufactured by Shipley, PAR710 (trade name) manufactured by Sumitomo Chemical Co., Ltd., SEPR430 (trade name) manufactured by Shin-Etsu Chemical Co., Ltd., and the like. Also, for example, Proc. SPIE, Vol. 3999, 330-334 (2000), Proc. SPIE, Vol. 3999, 357-364 (2000), and Proc. SPIE, Vol. 3999, 365-374 (2000).

また、ＷＯ２０１９／１８８５９５、ＷＯ２０１９／１８７８８１、ＷＯ２０１９／１８７８０３、ＷＯ２０１９／１６７７３７、ＷＯ２０１９／１６７７２５、ＷＯ２０１９／１８７４４５、ＷＯ２０１９／１６７４１９、ＷＯ２０１９／１２３８４２、ＷＯ２０１９／０５４２８２、ＷＯ２０１９／０５８９４５、ＷＯ２０１９／０５８８９０、ＷＯ２０１９／０３９２９０、ＷＯ２０１９／０４４２５９、ＷＯ２０１９／０４４２３１、ＷＯ２０１９／０２６５４９、ＷＯ２０１８／１９３９５４、ＷＯ２０１９／１７２０５４、ＷＯ２０１９／０２１９７５、ＷＯ２０１８／２３０３３４、ＷＯ２０１８／１９４１２３、特開２０１８－１８０５２５、ＷＯ２０１８／１９００８８、特開２０１８－０７０５９６、特開2018-028090, JP 2016-153409, JP 2016-130240, JP 2016-108325, JP 2016-047920, JP 2016-035570, JP 2016-035567, JP 2016-035565, JP 2019- 101417, JP 2019-117373, JP 2019-052294, JP 2019-008280, JP 2019-008279, JP 2019-003176, JP 2019-003175, JP 2018-197853, JP 2019-191298, JP 2019-061217, JP 2018-045152, JP 2018-022039, JP 2016-090441, JP 2015-10878, JP 2012-168279, JP 2012-022261, JP 2012-022258, JP 2011-043749, JP-A-2010-181857, JP-A-2010-128369, WO2018/031896, JP-A-2019-113855, WO2017/156388, WO2017/066319, JP-A-2018-41099, WO2016/065120, WO2024820, WO202482 2016-29498, JP-A-2011-253185, radiation-sensitive resin compositions, so-called resist compositions such as high-resolution patterning compositions based on organometallic solutions, and metal-containing resist compositions can be used. , but not limited to.

Examples of resist compositions include the following compositions.

Actinic ray-sensitive or sensitive resin containing a resin A having a repeating unit having an acid-decomposable group in which the polar group is protected by a protective group that is released by the action of an acid, and a compound represented by the general formula (21) A radioactive resin composition.

In general formula (21), m represents an integer of 1-6.

R ₁ and R ₂ each independently represent a fluorine atom or a perfluoroalkyl group.

L ₁ represents -O-, -S-, -COO-, -SO ₂ -, or -SO ₃ -.

_L2 represents an optionally substituted alkylene group or a single bond.

_W1 represents an optionally substituted cyclic organic group.

M ⁺ represents a cation.

Extreme ultraviolet rays or electron beams containing a compound having a metal-oxygen covalent bond and a solvent, wherein the metal element constituting the compound belongs to periods 3 to 7 of groups 3 to 15 of the periodic table. A metal-containing film-forming composition for lithography.

A radiation-sensitive resin comprising a polymer having a first structural unit represented by the following formula (31) and a second structural unit represented by the following formula (32) containing an acid-labile group, and an acid generator. Composition.

(In formula (31), Ar is a group obtained by removing (n+1) hydrogen atoms from arene having 6 to 20 carbon atoms.R ¹ is a hydroxy group, a sulfanyl group, or a monovalent group having 1 to 20 carbon atoms. n is an integer of 0 to 11. When n is 2 or more, the plurality of R ¹ are the same or different, and R ² is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. In formula (32), R ³ is a monovalent group having 1 to 20 carbon atoms containing the acid dissociable group, Z is a single bond, an oxygen atom or a sulfur atom, R ⁴ is , a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.)

A resist composition containing a resin (A1) containing a structural unit having a cyclic carbonate structure, a structural unit represented by the following formula, and a structural unit having an acid-labile group, and an acid generator.

[In the formula,
R ² represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom, X ¹ is a single bond, -CO-O-* or -CO-NR ⁴ -* * represents a bond with -Ar, R ⁴ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, Ar is one or more groups selected from the group consisting of a hydroxy group and a carboxyl group represents an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have ]

Examples of resist films include the following.

A resist film containing a base resin containing a repeating unit represented by the following formula (a1) and/or a repeating unit represented by the following formula (a2), and a repeating unit that is bonded to a polymer main chain and generates an acid upon exposure. .

(In formulas (a1) and (a2), R ^A is each independently a hydrogen atom or a methyl group; R ¹ and R ² are each independently a tertiary alkyl group having 4 to 6 carbon atoms; Each R ³ is independently a fluorine atom or a methyl group, m is an integer of 0 to 4, X ¹ is a single bond, a phenylene group or a naphthylene group, an ester bond, a lactone ring, or a phenylene is a linking group having 1 to 12 carbon atoms and containing at least one selected from a group and a naphthylene group, and X ² is a single bond, an ester bond or an amide bond.)

Examples of resist materials include the following.

A resist material containing a polymer having a repeating unit represented by formula (b1) or formula (b2) below.

(In formula (b1) and formula (b2), R ^A is a hydrogen atom or a methyl group. X ¹ is a single bond or an ester group. X ² is a linear, branched or cyclic carbon an alkylene group having 1 to 12 carbon atoms or an arylene group having 6 to 10 carbon atoms, and part of the methylene groups constituting the alkylene group may be substituted with an ether group, an ester group or a lactone ring-containing group, In addition, at least one hydrogen atom contained in X ² is substituted with a bromine atom, and X ³ is a single bond, an ether group, an ester group, or a linear, branched or cyclic group having 1 to 12 carbon atoms. an alkylene group, part of the methylene groups constituting the alkylene group may be substituted with an ether group or an ester group, and each of Rf ¹ to Rf ⁴ independently represents a hydrogen atom, a fluorine atom or a trifluoro a methyl group, at least one of which is a fluorine atom or a trifluoromethyl group, and Rf ¹ and Rf ² may combine to form a carbonyl group, and R ¹ to R ⁵ each independently linear, branched or cyclic alkyl groups having 1 to 12 carbon atoms, linear, branched or cyclic alkenyl groups having 2 to 12 carbon atoms, alkynyl groups having 2 to 12 carbon atoms, and 6 to 20 carbon atoms an aryl group, an aralkyl group having 7 to 12 carbon atoms, or an aryloxyalkyl group having 7 to 12 carbon atoms, and some or all of the hydrogen atoms of these groups are hydroxy groups, carboxy groups, halogen atoms, oxo group, cyano group, amido group, nitro group, sultone group, sulfone group or sulfonium salt-containing group, and some of the methylene groups constituting these groups are ether groups, ester groups and carbonyl groups. , may be substituted with a carbonate group or a sulfonate ester group.In addition, R ¹ and R ² may combine to form a ring together with the sulfur atom to which they are bonded.)

A resist material containing a base resin containing a polymer containing a repeating unit represented by the following formula (a).

(In formula (a), R ^A is a hydrogen atom or a methyl group. R ¹ is a hydrogen atom or an acid-labile group. R ² is a linear, branched or cyclic C 1 to 6 alkyl groups or halogen atoms other than bromine, X ¹ is a single bond or a phenylene group, or a linear, branched or cyclic C 1-12 group which may contain an ester group or a lactone ring is an alkylene group of X ² is -O-, -O-CH ₂ - or -NH-, m is an integer of 1 to 4, and n is an integer of 0 to 3.)
A resist composition that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid,
Containing a base component (A) whose solubility in a developer changes under the action of an acid and a fluorine additive component (F) which exhibits decomposability in an alkaline developer,
The fluorine additive component (F) includes a structural unit (f1) containing a base dissociable group and a structural unit (f2) containing a group represented by the following general formula (f2-r-1): fluorine A resist composition comprising a resin component (F1).

[In formula (f2-r-1), each Rf ²¹ is independently a hydrogen atom, an alkyl group, an alkoxy group, a hydroxyl group, a hydroxyalkyl group, or a cyano group. n" is an integer of 0 to 2. * is a bond.]

The structural unit (f1) includes a structural unit represented by the following general formula (f1-1) or a structural unit represented by the following general formula (f1-2).

[In formulas (f1-1) and (f1-2), each R is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. X is a divalent linking group having no acid-labile site. A _aryl is an optionally substituted divalent aromatic cyclic group. X ₀₁ is a single bond or a divalent linking group. Each R ² is independently an organic group having a fluorine atom. ]

Examples of coatings, coating solutions, and coating compositions include the following.

A coating containing a metal oxo-hydroxo network with organic ligands via metal carbon bonds and/or metal carboxylate bonds.

An inorganic oxo/hydroxo-based composition.

a coating solution comprising an organic solvent; a first organometallic composition comprising the formula R _z SnO _{(2-(z/2)-(x/2))} (OH) _x where 0<z ≦2 and 0<(z+x)≦4), represented by the formula R′ _n SnX _4-n where n=1 or 2, or mixtures thereof, where R and R′ is independently a hydrocarbyl group having from 1 to 31 carbon atoms, and X is a ligand or combination thereof having a hydrolyzable bond to Sn; and a hydrolyzable metal compound of the formula MX' _v , where M is a metal selected from Groups 2-16 of the Periodic Table of the Elements, v=a number from 2 to 6, and X′ is a ligand or combination thereof having a hydrolyzable MX bond.

A coating solution comprising an organic solvent and a first organometallic compound represented by the formula RSnO _(3/2-x/2) (OH) _x where 0<x<3, wherein the solution from about 0.0025M to about 1.5M tin, and R is an alkyl or cycloalkyl group having 3 to 31 carbon atoms, wherein said alkyl or cycloalkyl group is a secondary or secondary A coating solution bonded to tin at a tertiary carbon atom.

An aqueous inorganic pattern-forming precursor comprising a mixture of water, a metal suboxide cation, a polyatomic inorganic anion, and a radiation-sensitive ligand comprising a peroxide group.

Exposure is performed through a mask (reticle) for forming a predetermined pattern, and for example, i-ray, KrF excimer laser, ArF excimer laser, EUV (extreme ultraviolet) or EB (electron beam) is used. The underlayer film-forming composition according to the invention is preferably applied for EB (electron beam) or EUV (extreme ultraviolet) exposure, and more preferably for EUV (extreme ultraviolet) exposure. An alkaline developer is used for development, and the development temperature is selected from 5° C. to 50° C. and the development time is appropriately selected from 10 seconds to 300 seconds. Examples of the alkaline developer include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, primary amines such as ethylamine and n-propylamine, diethylamine, secondary amines such as di-n-butylamine; tertiary amines such as triethylamine and methyldiethylamine; alcohol amines such as dimethylethanolamine and triethanolamine; Aqueous solutions of alkalis such as quaternary ammonium salts, pyrrole, cyclic amines such as piperidine, and the like can be used. Further, an alcohol such as isopropyl alcohol or a nonionic surfactant may be added in an appropriate amount to the aqueous alkali solution. Preferred developers among these are quaternary ammonium salts, more preferably tetramethylammonium hydroxide and choline. Furthermore, a surfactant or the like can be added to these developers. It is also possible to use a method of developing with an organic solvent such as butyl acetate instead of the alkaline developer, and developing the portion where the rate of alkali dissolution of the photoresist is not improved. An organic film pattern is formed through the above steps.

Then, a step of impregnating the organic film pattern with a metal compound is performed. Metal compounds are, for example, liquids or gases. The impregnating metal compound can be an organometallic compound. Trimethylaluminum (TMA) is preferred. Metal compounds can also be chlorides.

The step of impregnating the organic film pattern with the metal compound is not particularly limited, and can be carried out by a method known per se. The organic film pattern impregnated with the metal compound may be treated in an atmosphere containing at least one selected from the group consisting of water, oxygen and ozone. This treatment may involve heating. The heating temperature is, for example, 50° C. or higher and 180° C. or lower. Preferably, the amount of diffusion of the metal at a depth of 30 nm from the surface of the underlayer film is 10 atm % or less.

Then, using the formed organic film pattern as a mask, the underlying film is dry-etched. At that time, when the inorganic film is formed on the surface of the semiconductor substrate used, the surface of the inorganic film is exposed, and when the inorganic film is not formed on the surface of the semiconductor substrate used, the semiconductor substrate is exposed. expose the surface.

After that, a semiconductor device can be manufactured through a process of processing the substrate by a method known per se (dry etching method, etc.).

The present invention will be described in more detail below with reference to examples, etc., but the present invention is not limited by the following examples, etc.

The apparatus used for measuring the weight-average molecular weight of the polymers obtained in the Synthesis Examples below is shown.
Apparatus: HLC-8320GPC manufactured by Tosoh Corporation
GPC column: Shodex (registered trademark), Asahipak (registered trademark) (Showa Denko Co., Ltd.)
GPC measurement condition 1
Column temperature: 40°C
Flow rate: 0.35 mL/min Eluent: Tetrahydrofuran (THF)
Standard sample: Polystyrene (Tosoh Corporation)
GPC measurement condition 2
Column temperature: 40°C
Flow rate: 0.6 mL/minute Eluent: N,N-dimethylformamide (DMF)
Standard sample: Polystyrene (Tosoh Corporation)

<Synthesis Example 1>
Styrene (Tokyo Chemical Industry Co., Ltd. (manufactured)) 15.0 g, vinyl naphthalene (Maruzen Petrochemical Co., Ltd. (manufactured)) 29.6 g, 2-hydroxyethyl methacrylate (Tokyo Chemical Industry Co., Ltd. (manufactured)) 18.7 g, A solution of 2.0 g of azobisisobutyronitrile (AIBN) (manufactured by Tokyo Chemical Industry Co., Ltd.) and 209.0 g of propylene glycol monomethyl ether was added to the dropping funnel, and 52.3 g of propylene glycol monomethyl ether was added to the reaction flask. Under nitrogen atmosphere, the mixture was added dropwise at 80° C. and heated with stirring for 24 hours. A resin solution corresponding to the following was obtained, and the weight average molecular weight (Mw) measured in terms of polystyrene by GPC (GPC measurement condition 1) was 9,313.

<Synthesis Example 2>
Benzyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) 5.0 g, 2-hydroxyethyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) 14.8 g, azobisisobutyronitrile (AIBN) (Tokyo Chemical Industry Co., Ltd.) A solution of 1.2 g of propylene glycol monomethyl ether and 67.0 g of propylene glycol monomethyl ether was added to the dropping funnel, and the mixture was added dropwise to the reaction flask containing 16.7 g of propylene glycol monomethyl ether under a nitrogen atmosphere at 100°C and heated for 24 hours. Stirred. A resin solution corresponding to the following was obtained, and the weight average molecular weight (Mw) measured in terms of polystyrene by GPC (GPC measurement condition 2) was 8,824 (DMF).

<Synthesis Example 3>
Benzyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) 5.0 g, glycerin monomethacrylate (product name: Blemmer GLM, manufactured by NOF Corporation) 18.2 g, azobisisobutyronitrile (AIBN) (Tokyo Chemical Industry Co., Ltd.) A solution of 1.2 g of the company (manufactured) and 121.7 g of propylene glycol monomethyl ether was added to the dropping funnel, and added dropwise to the reaction flask containing 19.5 g of propylene glycol monomethyl ether under a nitrogen atmosphere at 100°C for 24 hours. It was heated and stirred. A resin solution corresponding to the following was obtained, and the weight average molecular weight (Mw) measured in terms of polystyrene by GPC (GPC measurement condition 2) was 15,480.

<Synthesis Example 4>
Terephthalic acid diglycidyl ester (manufactured by Nagase ChemteX Corporation, trade name: Denacol [registered trademark] EX711) 25.0 g, 2,2-dimethylsuccinic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) 13.2 g and tetrabutyl 1.46 g of phosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.) was added to 59.5 g of propylene glycol monomethyl ether in the reaction vessel and dissolved. After purging the reaction vessel with nitrogen, reaction was carried out at 110° C. for 4 hours to obtain a polymer solution. The polymer solution does not become cloudy even when cooled to room temperature, and has good solubility in propylene glycol monomethyl ether. A resin solution corresponding to the following was obtained, and the weight average molecular weight (Mw) measured in terms of polystyrene by GPC (GPC measurement condition 1) was 4,267.

<Example 1>
To 2.4 g of the polymer solution containing 0.75 g of the polymer obtained in Synthesis Example 1, 0.23 g of tetramethoxymethyl glycoluril (manufactured by Nippon Cytec Industries Co., Ltd., trade name: POWDERLINK (registered trademark) 1174) and 0.019 g of pyridinium paraphenolsulfonic acid (Patent No. 6256719, Synthesis Example 1) was mixed, and 15.1 g of propylene glycol monomethyl ether and 7.2 g of propylene glycol monomethyl ether acetate were added and dissolved. Thereafter, the mixture was filtered using a polyethylene microfilter having a pore size of 0.05 μm to obtain a composition for forming a resist underlayer film for lithography.

<Example 2>
To 4.9 g of the polymer solution containing 0.85 g of the polymer obtained in Synthesis Example 2, 0.12 g of tetramethoxymethyl glycoluril (manufactured by Nippon Cytec Industries Co., Ltd., trade name: POWDERLINK (registered trademark) 1174) and 0.017 g of pyridinium paraphenolsulfonic acid (Patent No. 6256719, Synthesis Example 1) was mixed, and 12.7 g of propylene glycol monomethyl ether and 7.2 g of propylene glycol monomethyl ether acetate were added and dissolved. Thereafter, the mixture was filtered using a polyethylene microfilter having a pore size of 0.05 μm to obtain a composition for forming a resist underlayer film for lithography.

<Example 3>
To 3.9 g of the polymer solution containing 0.68 g of the polymer obtained in Synthesis Example 3, 0.10 g of tetramethoxymethyl glycoluril (manufactured by Nippon Cytec Industries Co., Ltd., trade name: POWDERLINK (registered trademark) 1174) and 0.014 g of pyridinium paraphenolsulfonic acid (Patent No. 6256719, Synthesis Example 1) was mixed, and 14.1 g of propylene glycol monomethyl ether and 1.9 g of propylene glycol monomethyl ether acetate were added and dissolved. Thereafter, the mixture was filtered using a polyethylene microfilter having a pore size of 0.05 μm to obtain a composition for forming a resist underlayer film for lithography.

<Example 4>
VP-8000 (manufactured by Nippon Soda Co., Ltd.) 0.69 g, tetramethoxymethyl glycoluril (manufactured by Nippon Cytec Industries Co., Ltd., trade name: POWDERLINK [registered trademark] 1174) 0.10 g and pyridinium paraphenolsulfonic acid (Japanese Patent No. 6256719, Synthesis Example 1) 0.021 g was mixed, and 5.8 g of propylene glycol monomethyl ether and 13.4 g of propylene glycol monomethyl ether acetate were added and dissolved. Thereafter, the mixture was filtered using a polyethylene microfilter having a pore size of 0.05 μm to obtain a composition for forming a resist underlayer film for lithography.

<Comparative Example 1>
To 2.4 g of the polymer solution containing 0.75 g of the polymer obtained in Synthesis Example 4, 0.22 g of tetramethoxymethyl glycoluril (manufactured by Nippon Cytec Industries Co., Ltd., trade name: POWDERLINK (registered trademark) 1174) and 0.019 g of pyridinium paraphenolsulfonic acid (Patent No. 6256719, Synthesis Example 1) was mixed, and 15.1 g of propylene glycol monomethyl ether and 7.2 g of propylene glycol monomethyl ether acetate were added and dissolved. Thereafter, the mixture was filtered using a polyethylene microfilter having a pore size of 0.05 μm to obtain a composition for forming a resist underlayer film for lithography.

(Metalization characteristics)
An organic film was formed on a Si substrate using the resist underlayer film compositions of Examples 1 to 4 and Comparative Example 1, and the organic film was metallized using trimethylaluminum (TMA) to evaluate metallization characteristics.

Each of the above resist underlayer film compositions was applied onto a 4-inch Si substrate by spin coating. The rotation speed was adjusted to 1,000 to 3,500 rpm. After coating, the solvent was removed by drying, and baking was further performed at 205° C. for 5 minutes to advance the cross-linking reaction. The film thickness after baking was adjusted to 100 nm. The obtained organic film was used as a sample for metallization treatment.

Metallization was performed with an atomic layer deposition (ALD) deposition system (AT-400, Anric technology). Specifically, a sample for metallization treatment was placed in an ALD apparatus, and gas phase TMA was introduced into the apparatus until a predetermined pressure was reached. After the TMA exposure, the gas phase in the apparatus was replaced with water vapor (H ₂ O) to increase the pressure to a predetermined level, and the valve was closed to maintain the pressure for a predetermined period of time. The temperature was set at 150° C. and 91 cycles were performed. By this operation, TMA is oxidized to aluminum hydroxide.

Here, an ALD apparatus is used for the metallization process, but the purpose of the operation is to impregnate TMA into the resist underlayer film, and it is not so-called atomic layer deposition (ALD) that deposits an atomic layer on the substrate.

The degree of metallization is measured by XPS; The results are shown in the table. On the other hand, the calculated carbonyl group content (% by mass) in the film after film formation is also shown in the table.

From the above results, in Examples 1 to 4, compared with Comparative Example 1, Al atom % at a depth of 30 nm from the film surface is about half the permeation rate. Also, it was confirmed that the higher the carbonyl group content in the film, the higher the Al atom % in the film.

(Test of optical parameters)
Each of the resist underlayer film-forming compositions for lithography prepared in Examples 1 to 4 and Comparative Example 1 was applied onto a silicon wafer by spin coating. The silicon wafer was placed on a hot plate and baked at 205° C. for 1 minute to form a resist underlayer film (thickness: 0.50 μm). These resist underlayer films were measured for refractive index (n value) and attenuation coefficient (k value) at wavelengths of 193 nm and 248 nm using a spectroscopic ellipsometer (manufactured by JA Woollam, VUV-VASE VU-302). . The results are shown in the table.

According to the present invention, the lower layer film material is applied onto the film to be processed of the substrate having the film to be processed, the organic film is formed using the pattern forming material, and after patterning, the organic film is impregnated with the metal compound. An underlayer film material used when processing the underlayer film and the film to be processed using the composite film obtained as a mask pattern, wherein the underlayer suppresses impregnation of the metal compound when the organic film is impregnated with the metal compound. A membrane material can be provided.

Claims

An underlayer film forming composition used for forming a composite film mask pattern in which a patterned organic film is impregnated with a metal compound on a semiconductor substrate, the composition comprising a polymer containing a hydroxy group and containing no more than 22% by weight. An underlayer film-forming composition that provides an underlayer film containing a carbonyl group of
The polymer has the following formula (I):

[in the formula (I),
R 1 represents a hydrogen atom or a methyl group,
L 1 represents a single bond, -COO- group, -CONH- group, or a linear or branched alkylene group having 1 to 5 carbon atoms,
A represents a linear or branched hydroxyalkyl group having 1 to 20 carbon atoms. ]
2. The underlayer film-forming composition according to claim 1, comprising a repeating unit structure represented by:
The underlayer film-forming composition according to claim 2, wherein the polymer contains 20 mol% to 90 mol% of the repeating unit structure represented by the formula (I) with respect to the entire polymer.
The polymer has the following formula (II):

[in the formula (II),
T 1 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms which may be substituted with a halogeno group;
L 2 represents a single bond, -COO- group, -CONH- group, or a linear or branched alkylene group having 1 to 5 carbon atoms,
R 1 is substituted with a halogeno group, a carboxy group, a nitro group, a cyano group, a methylenedioxy group, an acetoxy group, a methylthio group, an alkoxy group having 1 to 9 carbon atoms, or an alkyl group having 1 to 3 carbon atoms; represents an amino group which may be substituted, or an alkyl group having 1 to 10 carbon atoms which may be substituted with a hydroxy group or a halogeno group;
r1 represents an integer of 0 to 3,
n1 represents an integer of 0 to 2,
a represents an integer of 0 to 6; ]
2. The underlayer film-forming composition according to claim 1, comprising a repeating unit structure represented by:
The underlayer film-forming composition according to claim 4, wherein the polymer contains 10 mol% to 100 mol% of the repeating unit structure represented by the formula (II) with respect to the entire polymer.
The underlayer film-forming composition according to claim 1, wherein the metal compound contains aluminum.
The underlayer film-forming composition according to claim 1, further comprising a solvent.
The underlayer film-forming composition according to claim 1, further comprising a cross-linking agent and/or an acid catalyst.
An underlayer film characterized by being a baked product of a coating film made of the underlayer film-forming composition according to any one of claims 1 to 8.
An underlayer film used for forming on a semiconductor substrate a composite film mask pattern in which a patterned organic film is impregnated with a metal compound, the underlayer film containing 22% by mass or less of carbonyl groups.
The underlayer film according to claim 10, wherein the metal compound contains aluminum.
A step of applying the underlayer film-forming composition according to any one of claims 1 to 8 onto a semiconductor substrate and baking the composition to form an underlayer film;
forming a patterned organic film on the underlayer film, then exposing and developing to form an organic film pattern;
A method for manufacturing a substrate with an organic film pattern for use in manufacturing a semiconductor, comprising the step of impregnating the organic film pattern with a metal compound.
13. The method of manufacturing a substrate according to claim 12, wherein the step of impregnating the organic film pattern with the metal compound is carried out so that the amount of diffusion of the metal at a depth of 30 nm from the surface of the lower layer film is 10 atm % or less.
The method for manufacturing a substrate according to claim 12, wherein the metal compound contains aluminum.
A step of forming an underlayer film using the underlayer film-forming composition according to any one of claims 1 to 8 on a semiconductor substrate which may have an inorganic film formed thereon;
forming an organic film pattern on the underlayer film;
impregnating the organic film pattern with a metal compound;
A method of manufacturing a semiconductor device, comprising a step of etching the inorganic film or the semiconductor substrate using the organic film pattern impregnated with the metal as a mask.
16. The method of manufacturing a semiconductor device according to claim 15, wherein the step of impregnating the organic film pattern with the metal compound is performed so that the amount of diffusion of the metal at a depth of 30 nm from the surface of the lower layer film is 10 atm % or less.
The method of manufacturing a semiconductor device according to claim 15, wherein the metal compound contains aluminum.
A composite film mask pattern obtained by impregnating an organic film with a metal compound and patterning an underlayer film-forming composition comprising a polymer containing a hydroxyl group and providing an underlayer film containing 22% by mass or less of a carbonyl group is formed on a semiconductor substrate. Use for molding.
The polymer has the following formula (I):

[in the formula (I),
R 1 represents a hydrogen atom or a methyl group,
L 1 represents a single bond, -COO- group, -CONH- group, or a linear or branched alkylene group having 1 to 5 carbon atoms,
A represents a linear or branched hydroxyalkyl group having 1 to 20 carbon atoms. ]
19. Use according to claim 18, comprising a repeating unit structure represented by
The polymer has the following formula (II):

[in the formula (II),
T 1 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms which may be substituted with a halogeno group;
L 2 represents a single bond, -COO- group, -CONH- group, or a linear or branched alkylene group having 1 to 5 carbon atoms,
R 1 is substituted with a halogeno group, a carboxy group, a nitro group, a cyano group, a methylenedioxy group, an acetoxy group, a methylthio group, an alkoxy group having 1 to 9 carbon atoms, or an alkyl group having 1 to 3 carbon atoms; represents an amino group which may be substituted, or an alkyl group having 1 to 10 carbon atoms which may be substituted with a hydroxy group or a halogeno group;
r1 represents an integer of 0 to 3,
n1 represents an integer of 0 to 2,
a represents an integer of 0 to 6; ]
19. Use according to claim 18, comprising a repeating unit structure represented by
The use according to claim 18, wherein the organic film impregnated with the metal compound has a metal diffusion amount of 10 atm% or less at a depth of 30 nm from the surface of the underlying film.
The use according to any one of claims 18-21, wherein said metal compound comprises aluminium.