Resist underlayer film forming composition containing substituted crosslinkable compound
阅读说明：本技术 包含被置换的交联性化合物的抗蚀剂下层膜形成用组合物 (Resist underlayer film forming composition containing substituted crosslinkable compound ) 是由 桥本圭祐 高濑显司 新城彻也 坂本力丸 远藤贵文 西卷裕和 于 2014-06-24 设计创作，主要内容包括：本发明提供一种升华物的产生少,涂布于具有孔图案的基板时埋入性良好,具有高干蚀刻耐性、摆动耐性、耐热性等的光刻工序所使用的抗蚀剂下层膜,以及使用了该抗蚀剂下层膜的半导体装置的制造方法。作为解决本发明课题的方法为一种抗蚀剂下层膜形成用组合物,其包含树脂、以及下述式(1)或式(2)：(式中,Q<Sup>1</Sup>表示单键或m1价的有机基团,R<Sup>1</Sup>和R<Sup>4</Sup>分别表示碳原子数2～10的烷基、或具有碳原子数1～10的烷氧基的碳原子数2～10的烷基,R<Sup>2</Sup>和R<Sup>5</Sup>分别表示氢原子或甲基,R<Sup>3</Sup>和R<Sup>6</Sup>分别表示碳原子数1～10的烷基或碳原子数6～40的芳基。)所示的交联性化合物。<Image he="369" wi="700" file="DDA0002238881300000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>(The invention provides a resist underlayer film used in a lithography process, which generates little sublimate, has good embeddability when being coated on a substrate with a hole pattern, and has high dry etching resistance, oscillation resistance, heat resistance and the like, and a method for manufacturing a semiconductor device using the resist underlayer film. The composition for forming a resist underlayer film, which is a means for solving the problems of the present invention, comprises a resin and the following formula (1) or formula (2): (in the formula, Q 1 Represents a single bond or an organic group having a valence of m1, R 1 And R 4 Each represents a carbon atom number of 2 to c10 alkyl group or C2-10 alkyl group having C1-10 alkoxy group, R 2 And R 5 Each represents a hydrogen atom or a methyl group, R 3 And R 6 Each represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 40 carbon atoms. ) The crosslinkable compound shown.)
1. A compound represented by the following formula (5),
in the formula, Q3Represents an isopropylidene group, R14Represents an alkyl group having 2 to 10 carbon atoms and having an alkoxy group having 1 to 10 carbon atoms, R15Represents a hydrogen atom or a methyl group, R13Represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 40 carbon atoms,
n17 represents an integer of 1. ltoreq. n 17. ltoreq.3, n18 represents an integer of 1. ltoreq. n 18. ltoreq.4, n19 represents an integer of 0. ltoreq. n 19. ltoreq.3, n20 represents an integer of 0. ltoreq. n 20. ltoreq.3, and 2. ltoreq. n17+ n18+ n19+ n 20. ltoreq.5.
Technical Field
The present invention relates to a crosslinking catalyst for a resist underlayer film forming composition for lithography effective in processing a semiconductor substrate, a resist underlayer film forming composition containing the crosslinking catalyst, a resist pattern forming method using the resist underlayer film forming composition, and a method for manufacturing a semiconductor device.
Background
In the manufacture of semiconductor devices, microfabrication has been conventionally performed by photolithography using a photoresist composition. The micro-machining is a machining method comprising: a processing method in which a thin film of a photoresist composition is formed on a substrate to be processed such as a silicon wafer, active rays such as ultraviolet rays are irradiated onto the thin film through a mask pattern on which a pattern of a semiconductor device is drawn, development is performed, and the substrate to be processed such as a silicon wafer is etched using the obtained photoresist pattern as a protective film. However, in recent years, the degree of integration of semiconductor devices has increased, and the wavelength of the active light used has also been reduced from KrF excimer laser (248nm) to ArF excimer laser (193 nm). Accordingly, the influence of diffuse reflection of active light from the substrate and standing waves becomes a serious problem, and a method of providing a resist underlayer film called a bottom anti-reflection coating (BARC) between the photoresist and the substrate to be processed is widely used.
Further, for the purpose of further microfabrication, a lithography technique using extreme ultraviolet (EUV, 13.5nm) or Electron Beam (EB) for active light has been developed. In EUV lithography and EB lithography, since diffuse reflection and standing waves from a substrate do not generally occur, a specific antireflection film is not required, but a resist underlayer film has been widely studied as an auxiliary film for the purpose of improving the resolution and adhesion of a resist pattern.
In order to prevent such intermixing (mixing) of the resist underlayer film formed between the photoresist and the substrate to be processed and the resist laminated on the upper layer, it is common to form a thermosetting crosslinked film that does not intermix with the resist after applying the thermosetting crosslinked film on the substrate to be processed and then performing a baking step.
In general, in order to form such a thermosetting film, a crosslinkable compound (crosslinking agent) and a catalyst for promoting a crosslinking reaction (crosslinking catalyst) are blended in a composition for forming a resist underlayer film, in addition to a polymer resin as a main component. In particular, as the crosslinking catalyst, a thermal acid generator such as a sulfonic acid compound, a carboxylic acid compound, or a sulfonic acid ester is mainly used.
However, in recent years, in the photolithography process for manufacturing semiconductor devices, when forming a resist underlayer film using the resist underlayer film forming composition, generation of sublimation components (sublimates) derived from low-molecular compounds such as the polymer resin, the crosslinking agent, and the crosslinking catalyst during firing becomes a new problem. Such sublimates may adhere and accumulate in the film deposition apparatus to contaminate the apparatus in the semiconductor device manufacturing process, and they may adhere to the wafer as foreign matter to cause defects (defects) and the like. Therefore, a new underlayer coating composition that suppresses the generation of sublimates from the resist underlayer coating as much as possible has been proposed, and studies have been made on a resist underlayer coating exhibiting such low sublimation properties (see, for example, patent documents 1 and 2).
In addition, for good embeddability and a small amount of sublimate, a technique using a crosslinking agent having an N atom such as a glycoluril-based crosslinking agent having a butyl ether group and a melamine-based crosslinking agent has been disclosed (see patent document 3).
Further, compounds having a side chain with a hydroxymethyl group, a methoxymethyl group, an ethoxymethyl group, a methoxypropoxymethyl group, or the like are disclosed (see patent documents 4 and 5).
Disclosure of Invention
Problems to be solved by the invention
The invention provides a resist underlayer film forming composition used in a photolithography process for manufacturing a semiconductor device.
The invention provides a composition for forming a resist underlayer film, which generates little sublimate and has good embeddability when being coated on a substrate having a hole pattern.
Means for solving the problems
The present invention provides, as aspect 1, a resist underlayer film forming composition comprising a resin and a crosslinkable compound represented by formula (1) or formula (2),
in the formula, Q1Represents a single bond or an organic group having a valence of m1, R1And R4Each represents an alkyl group having 2 to 10 carbon atoms or an alkyl group having 2 to 10 carbon atoms and having an alkoxy group having 1 to 10 carbon atoms，R2And R5Each represents a hydrogen atom or a methyl group, R3And R6Each represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 40 carbon atoms.
n1 represents an integer of 1. ltoreq. n 1. ltoreq.3, n2 represents an integer of 2. ltoreq. n 2. ltoreq.5, n3 represents an integer of 0. ltoreq. n 3. ltoreq.3, n4 represents an integer of 0. ltoreq. n 4. ltoreq.3, and 3. ltoreq. n1+ n2+ n3+ n 4. ltoreq.6.
n5 represents an integer of 1. ltoreq. n 5. ltoreq.3, n6 represents an integer of 1. ltoreq.
The composition for forming a resist underlayer film according to claim 1, wherein Q is1A single bond, or an organic group having a valence of m1 selected from a chain hydrocarbon group having 1 to 10 carbon atoms, an aromatic group having 6 to 40 carbon atoms, or a combination thereof,
the 3 rd aspect is the resist underlayer film forming composition according to the 1 st or 2 nd aspect, wherein the crosslinkable compound represented by the formula (1) or (2) is obtained by reacting a compound represented by the following formula (3) or (4) with a hydroxyl group-containing ether compound or a C2-10 alcohol,
in the formula, Q2Represents a single bond or an organic group having a valence of m 2. R8、R9、R11And R12Each represents a hydrogen atom or a methyl group, R7And R10Each represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 40 carbon atoms.
n9 represents an integer of 1. ltoreq. n 9. ltoreq.3, n10 represents an integer of 2. ltoreq. n 10. ltoreq.5, n11 represents an integer of 0. ltoreq. n 11. ltoreq.3, n12 represents an integer of 0. ltoreq. n 12. ltoreq.3, and 3. ltoreq. n9+ n10+ n11+ n 12. ltoreq.6.
n13 represents an integer of 1. ltoreq. n 13. ltoreq.3, n14 represents an integer of 1. ltoreq.
An aspect 4 of the present invention is the resist underlayer film forming composition according to aspect 3, wherein the reaction of the compound represented by formula (3) or formula (4) with the hydroxyl group-containing ether compound or the alcohol having 2 to 10 carbon atoms is carried out in the presence of an acid catalyst,
in view 5, the resist underlayer film forming composition according to view 4, wherein the acid catalyst is an ion exchange resin for a catalyst,
the resist underlayer film forming composition according to
the resist underlayer film forming composition according to any one of aspects 3 to 5, wherein the alcohol having 2 to 10 carbon atoms is ethanol, 1-propanol, 2-methyl-1-propanol, butanol, 2-methoxyethanol or 2-ethoxyethanol,
the resist underlayer film forming composition according to
the resist underlayer film forming composition according to claim 9 is any one of claims 1 to 8, further comprising a crosslinking agent,
from the 10 th viewpoint, the composition for forming a resist underlayer film as described in any one of the 1 st to 9 th viewpoints, further comprising an acid and/or an acid generator,
an 11 th aspect is a resist underlayer film obtained by applying the resist underlayer film forming composition according to any one of aspects 1 to 10 to a semiconductor substrate and baking the composition,
as a 12 th aspect, the present invention provides a method for forming a resist pattern for use in semiconductor manufacturing, comprising the steps of: a step of applying the resist underlayer film forming composition according to any one of aspects 1 to 10 to a semiconductor substrate and firing the composition to form a resist underlayer film,
as a viewpoint 13, the present invention provides a method for manufacturing a semiconductor device, including the steps of: a step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film forming composition according to any one of aspects 1 to 10; forming a resist film on the resist underlayer film; a step of forming a resist pattern by irradiation with light or an electron beam and development; etching the resist underlayer film through the formed resist pattern; and processing the semiconductor substrate through the patterned resist underlayer film,
as a 14 th aspect, the present invention provides a method for manufacturing a semiconductor device, comprising the steps of: a step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film forming composition according to any one of aspects 1 to 10; forming a hard mask on the resist underlayer film; further forming a resist film on the hard mask; a step of forming a resist pattern by irradiation with light or an electron beam and development; etching the hard mask through the formed resist pattern; etching the resist underlayer film through the patterned hard mask; and processing the semiconductor substrate through the patterned resist underlayer film,
as a 15 th aspect, the manufacturing method according to the 14 th aspect, wherein the hard mask is formed by coating of an inorganic substance or vapor deposition of an inorganic substance, and
the 16 th aspect of the present invention is a compound represented by the following formula (5),
in the formula, Q3Represents an isopropylidene group, R14Represents an alkyl group having 2 to 10 carbon atoms or an alkyl group having 2 to 10 carbon atoms and having an alkoxy group having 1 to 10 carbon atoms, R15Represents a hydrogen atom or a methyl group, R13Represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 40 carbon atoms.
n17 represents an integer of 1. ltoreq. n 17. ltoreq.3, n18 represents an integer of 1. ltoreq. n 18. ltoreq.4, n19 represents an integer of 0. ltoreq. n 19. ltoreq.3, n20 represents an integer of 0. ltoreq. n 20. ltoreq.3, and 2. ltoreq. n17+ n18+ n19+ n 20. ltoreq.5.
ADVANTAGEOUS EFFECTS OF INVENTION
The crosslinkable compound used in the present invention is obtained by replacing an alkyl moiety (e.g., a low molecular weight alkyl group such as a methyl group) of an alkoxymethyl group with a long-chain alkyl group having 2 to 10 carbon atoms or an alkyl group having 2 to 10 carbon atoms and having an alkoxy group having 1 to 10 carbon atoms.
When the displaced crosslinkable compound bonds with the resin to form a crosslinked structure, the release component released from the crosslinkable compound becomes a compound having a large molecular weight corresponding to the alkyl moiety. Therefore, it is considered that when the resist underlayer film forming composition containing the crosslinkable compound of the present invention is coated on a substrate and heated, the amount of sublimed components can be reduced. As described above, the sublimates adhere to the inside of the chamber, and fall on the substrate, which causes coating defects.
Therefore, the composition of the present invention can suppress the occurrence of coating defects by using the substituted crosslinkable compound.
In addition, the crosslinking reaction between the resin and the crosslinkable compound obtained by replacing the alkyl moiety (e.g., a low molecular weight alkyl group such as a methyl group) of an alkoxymethyl group with a long-chain alkyl group having 2 to 10 carbon atoms or an alkyl group having 2 to 10 carbon atoms and having an alkoxy group having 1 to 10 carbon atoms proceeds slowly. Therefore, when the resist underlayer film forming composition containing the crosslinkable compound of the present invention is applied to a fine hole pattern, the decrease in fluidity associated with the three-dimensionality due to crosslinking does not occur temporarily after application. Therefore, by using the composition of the present invention, the resist underlayer film forming composition can be filled in the hole pattern without a gap.
Drawings
FIG. 1 is an NMR spectrum of a 4-substituted TBOM-BP-BU obtained in Synthesis example 3.
FIG. 2 is an NMR spectrum of ｃA 4-substituted TBOM-BIP-A obtained in Synthesis example 4.
FIG. 3 is an NMR spectrum of ｃA 4-substituted TPOM-BIP-A obtained in Synthesis example 5.
FIG. 4 is an NMR spectrum of ｃA 4-substituted TEOM-BIP-A obtained in Synthesis example 6.
FIG. 5 is an NMR spectrum of ｃA 4-substituted TIBOM-BIP-A obtained in Synthesis example 7.
FIG. 6 is an NMR spectrum of ｃA 4-substituted EGME-BIP-A obtained in Synthesis example 8.
FIG. 7 is an NMR spectrum of ｃA 4-substituted EGEE-BIP-A obtained in Synthesis example 9.
FIG. 8 is an NMR spectrum of ｃA 4-substituted PGME-BIP-A complex obtained in Synthesis example 10.
FIG. 9 is an NMR spectrum of ｃA 4-substituted EGIPE-BIP-A obtained in Synthesis example 11.
Detailed Description
The present invention relates to a composition for forming a resist underlayer film, which comprises a resin and a crosslinkable compound represented by formula (1) or formula (2).
The resist underlayer film forming composition of the present invention generally contains a resin, a crosslinkable compound represented by formula (1) or formula (2), and a solvent. Further, additives such as an acid generator and a surfactant may be contained as necessary. The solid content of the composition is 0.1-70% by mass or 0.1-60% by mass. The solid content is the content ratio of all components after the solvent is removed from the resist underlayer film forming composition. The solid content may contain a resin (polymer) in a proportion of 1 to 99.9 mass%, or 50 to 95 mass%, or 50 to 90 mass%.
The solid component may contain the crosslinkable compound represented by the formula (1) or (2) in an amount of 0.01 to 50% by mass, or 0.01 to 40% by mass, or 0.1 to 30% by mass.
The weight average molecular weight of the polymer used in the present invention is 600 to 1000000 or 600 to 200000.
In the crosslinkable compounds represented by the formulae (1) and (2) used in the present invention, Q1Represents a single bond or an organic group having a valence of m1, R1And R4Each represents an alkyl group having 2 to 10 carbon atoms or an alkyl group having 2 to 10 carbon atoms and having an alkoxy group having 1 to 10 carbon atoms, R2And R5Each represents a hydrogen atom or a methyl group, R3And R6Individual watchAn alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 40 carbon atoms.
n1 represents an integer of 1. ltoreq. n 1. ltoreq.3, n2 represents an integer of 2. ltoreq. n 2. ltoreq.5, n3 represents an integer of 0. ltoreq. n 3. ltoreq.3, n4 represents an integer of 0. ltoreq. n 4. ltoreq.3, and 3. ltoreq. n1+ n2+ n3+ n 4. ltoreq.6.
n5 represents an integer of 1. ltoreq. n 5. ltoreq.3, n6 represents an integer of 1. ltoreq.
Above Q1The organic group may be a single bond, or an m 1-valent organic group selected from a chain hydrocarbon group having 1 to 10 carbon atoms, an aromatic group having 6 to 40 carbon atoms, or a combination thereof. Examples of the chain hydrocarbon group include the following alkyl groups. Examples of the aromatic group include the following aromatic groups.
Examples of the alkyl group having 2 to 10 carbon atoms include an ethyl group, an n-propyl group, an isopropyl group, a cyclopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a cyclobutyl group, a 1-methyl-cyclopropyl group, a 2-methyl-cyclopropyl group, an n-pentyl group, a 1-methyl-n-butyl group, a 2-methyl-n-butyl group, a 3-methyl-n-butyl group, a 1, 1-dimethyl-n-propyl group, a 1, 2-dimethyl-n-propyl group, a 2, 2-dimethyl-n-propyl group, a 1-ethyl-n-propyl group, a cyclopentyl group, a 1-methyl-cyclobutyl group, a 2-methyl-cyclobutyl group, a 3-methyl-cyclobutyl group, a 1, 2-dimethyl-cyclopropyl group, a 2, 3-dimethyl-cyclopropyl group, a, 2-ethyl-cyclopropyl, n-hexyl, 1-methyl-n-pentyl, 2-methyl-n-pentyl, 3-methyl-n-pentyl, 4-methyl-n-pentyl, 1-dimethyl-n-butyl, 1, 2-dimethyl-n-butyl, 1, 3-dimethyl-n-butyl, 2, 2-dimethyl-n-butyl, 2, 3-dimethyl-n-butyl, 3-dimethyl-n-butyl, 1-ethyl-n-butyl, 2-ethyl-n-butyl, 1, 2-trimethyl-n-propyl, 1,2, 2-trimethyl-n-propyl, 1-ethyl-1-methyl-n-propyl, 1-ethyl-2-methyl-n-propyl, 1-methyl-n-propyl, 2-methyl-n-propyl, 3-methyl, Cyclohexyl, 1-methyl-cyclopentyl, 2-methyl-cyclopentyl, 3-methyl-cyclopentyl, 1-ethyl-cyclobutyl, 2-ethyl-cyclobutyl, 3-ethyl-cyclobutyl, 1, 2-dimethyl-cyclobutyl, 1, 3-dimethyl-cyclobutyl, 2, 2-dimethyl-cyclobutyl, 2, 3-dimethyl-cyclobutyl, 2, 4-dimethyl-cyclobutyl, 3-dimethyl-cyclobutyl, 1-n-propyl-cyclopropyl, 2-n-propyl-cyclopropyl, 1-isopropyl-cyclopropyl, 2-isopropyl-cyclopropyl, 1,2, 2-trimethyl-cyclopropyl, 1,2, 3-trimethyl-cyclopropyl, 2, 3-methyl-cyclopropyl, 2-methyl-cyclobutyl, 2-methyl-cyclopentyl, 2, 3-methyl-cyclobutyl, 2-dimethyl-cyclobutyl, 2,3, 2,2, 3-trimethyl-cyclopropyl, 1-ethyl-2-methyl-cyclopropyl, 2-ethyl-1-methyl-cyclopropyl, 2-ethyl-2-methyl-cyclopropyl, 2-ethyl-3-methyl-cyclopropyl, and the like.
The alkyl group having 1 to 10 carbon atoms may be exemplified by a methyl group in addition to the alkyl group having 2 to 10 carbon atoms.
Examples of the alkoxy group having 1 to 10 carbon atoms include a methoxy group, an ethoxy group, a n-propoxy group, an isopropoxy group, a n-butoxy group, an isobutoxy group, a sec-butoxy group, a tert-butoxy group, a n-pentoxy group, a 1-methyl-n-butoxy group, a 2-methyl-n-butoxy group, a 3-methyl-n-butoxy group, a 1, 1-dimethyl-n-propoxy group, a 1, 2-dimethyl-n-propoxy group, a 2, 2-dimethyl-n-propoxy group, a 1-ethyl-n-propoxy group, a n-hexoxy group, a 1-methyl-n-pentoxy group, a 2-methyl-n-pentoxy group, a 3-methyl-n-pentoxy group, a 4-methyl-n-pentoxy group, a 1, 1-dimethyl-n, 1, 3-dimethyl-n-butoxy group, 2, 2-dimethyl-n-butoxy group, 2, 3-dimethyl-n-butoxy group, 3-dimethyl-n-butoxy group, 1-ethyl-n-butoxy group, 2-ethyl-n-butoxy group, 1, 2-trimethyl-n-propoxy group, 1,2,2, -trimethyl-n-propoxy group, 1-ethyl-1-methyl-n-propoxy group, 1-ethyl-2-methyl-n-propoxy group and the like.
Examples of the aryl group having 6 to 40 carbon atoms include a phenyl group, a naphthyl group, an anthracenyl group and the like.
The crosslinkable compound represented by the formula (1) or (2) can be obtained by reacting a compound represented by the formula (3) or (4) with a hydroxyl group-containing ether compound or an alcohol having 2 to 10 carbon atoms.
A compound represented by the formula (1) or (2) wherein 1mol of an ether compound having a hydroxyl group or an alcohol having 2 to 10 carbon atoms is substituted with 1mol of a compound represented by the formula (3) or (4) is referred to as a 1-substituted compound, a compound represented by the formula (1) or (2) wherein 2 mol of the compound is substituted is referred to as a 2-substituted compound, a compound represented by the formula (1) or (2) wherein 3 mol of the compound is substituted is referred to as a 3-substituted compound, and a compound represented by the formula (1) or (2) wherein 4mol of the compound is substituted is referred to as a 4-substituted compound.
In the formulae (3) and (4), Q2Represents a single bond or an organic group having a valence of m 2. Namely, the above Q2The organic group may be a single bond or an m 2-valent organic group selected from a chain hydrocarbon group having 1 to 10 carbon atoms, an aromatic group having 6 to 40 carbon atoms, or a combination thereof. Examples of the chain hydrocarbon group include the above-mentioned alkyl groups. Examples of the aromatic group include the aromatic groups.
R8、R9、R11And R12Each represents a hydrogen atom or a methyl group, R7And R10Each represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 40 carbon atoms.
n9 represents an integer of 1. ltoreq. n 9. ltoreq.3, n10 represents an integer of 2. ltoreq. n 10. ltoreq.5, n11 represents an integer of 0. ltoreq. n 11. ltoreq.3, n12 represents an integer of 0. ltoreq. n 12. ltoreq.3, and 3. ltoreq. n9+ n10+ n11+ n 12. ltoreq.6.
n13 represents an integer of 1. ltoreq. n 13. ltoreq.3, n14 represents an integer of 1. ltoreq.
The reaction of the compound represented by the formula (3) or (4) with a hydroxyl group-containing ether compound or a C2-10 alcohol is carried out in the presence of an acid catalyst.
As the acid catalyst used herein, for example, p-toluenesulfonic acid, trifluoromethanesulfonic acid, and p-toluenesulfonic acid pyridine can be usedSalicylic acid, 5-sulfosalicylic acid, 4-phenolsulfonic acid, camphorsulfonic acid, 4-chlorobenzenesulfonic acid, benzenedisulfonic acid, 1-naphthalenesulfonic acid, citric acid, benzoic acid, hydroxybenzoic acid, naphthoic acid, and other acidic compounds.
However, an ion exchange resin for a catalyst may be used so that unreacted acid does not remain in the reaction system. As the ion exchange resin for the catalyst, for example, a sulfonic acid type strong acid type ion exchange resin can be used.
Examples of the above ether compound having a hydroxyl group include propylene glycol monomethyl ether and propylene glycol monoethyl ether.
Examples of the alcohol having 2 to 10 carbon atoms include ethanol, 1-propanol, 2-methyl-1-propanol, butanol, 2-methoxyethanol, and 2-ethoxyethanol.
The crosslinkable compounds represented by the formulae (1) and (2) used in the present invention are exemplified below.
The compounds represented by the formulae (3) and (4) used in the present invention are exemplified below.
The resin used in the present invention may be any resin that can form a crosslinking reaction with the crosslinkable compound. Examples of the crosslinking group present in the resin include a hydroxyl group, a carboxyl group, an amino group, and an alkoxy group.
Examples of the resin having such a crosslinking group include acrylic resins and novolak resins, and novolak resins can be preferably used.
The novolac resin is obtained by reacting a compound having an aromatic ring with an aldehyde or ketone compound in the presence of an acid catalyst. Examples of the aromatic ring-containing compound include benzene, phenol, naphthalene, phloroglucinol, hydroxynaphthalene, fluorene, carbazole, bisphenol S, diphenylamine, triphenylamine, phenylnaphthylamine, anthracene, hydroxyanthracene, phenothiazine, and thiophene
Further, examples of the aldehyde include formaldehyde, paraformaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde, valeraldehyde, hexanal (カプロンアルデヒ ド), 2-methylbutyraldehyde, hexanal (ヘキシルアルデヒ ド), undecalaldehyde, 7-methoxy-3, 7-dimethyloctanal, cyclohexanal, 3-methyl-2-butyraldehyde, glyoxal, malonaldehyde, succinaldehyde, glutaraldehyde, hexanal and other saturated aliphatic aldehydes, acrolein, methacrolein and other unsaturated aliphatic aldehydes, furfural, pyridine and other heterocyclic aldehydes, benzaldehyde, naphthaldehyde, anthracene formaldehyde, phenanthrene formaldehyde, salicylaldehyde, phenylacetaldehyde, 3-phenylpropionaldehyde, tolualdehyde, (N, N-dimethylamino) benzaldehyde, acetoxybenzaldehyde, 1-pyrene formaldehyde and other aromatic aldehydes.
The ketone is a diaryl ketone, and examples thereof include diphenyl ketone, phenylnaphthyl ketone, dinaphthyl ketone, phenyltolyl ketone, xylyl ketone, and 9-fluorenone.
The novolak resin used in the present invention is a resin obtained by condensing a compound containing an aromatic ring with aldehydes or ketones. In the condensation reaction, the aldehyde or ketone may be used in an amount of 0.1 to 10 equivalents relative to 1 equivalent of the phenyl group which is contained in the aromatic compound having a heterocyclic group and which is involved in the reaction.
Examples of the acid catalyst used in the condensation reaction include inorganic acids such as sulfuric acid, phosphoric acid, and perchloric acid, organic sulfonic acids such as p-toluenesulfonic acid and p-toluenesulfonic acid monohydrate, and carboxylic acids such as formic acid and oxalic acid. The amount of the acid catalyst to be used is variously selected depending on the kind of the acid to be used. Usually, the amount of the aromatic ring-containing compound is 0.001 to 10000 parts by mass, preferably 0.01 to 1000 parts by mass, and more preferably 0.1 to 100 parts by mass, per 100 parts by mass of the aromatic ring-containing compound.
The condensation reaction can be carried out without a solvent, but is usually carried out using a solvent. All solvents can be used as long as they do not inhibit the reaction. Examples thereof include tetrahydrofuran and tetrahydrofuranCyclic ethers such as alkanes. The acid catalyst used may also function as a solvent if it is a liquid such as formic acid.
The reaction temperature during the condensation is usually 40 ℃ to 200 ℃. The reaction time is variously selected depending on the reaction temperature, and is usually about 30 minutes to 50 hours.
In the present invention, p-toluenesulfonic acid, trifluoromethanesulfonic acid, and pyridinium p-toluenesulfonate may be used as a catalyst for promoting a crosslinking reaction between a resin and a crosslinkable compound represented by formula (1) or formula (2)
The resist underlayer film forming composition for lithography of the present invention may further contain, in addition to the above components, a light absorbing agent, a rheology adjusting agent, an adhesion assisting agent, a surfactant and the like as required.
The composition may further contain a crosslinking agent other than the crosslinking agent compounds represented by the formulae (1) and (2). Examples of the crosslinking agent include melamine-based crosslinking agents, substituted urea-based crosslinking agents, and polymer-based crosslinking agents thereof. Preferred crosslinking agents having at least 2 crosslinking-forming substituents are compounds such as methoxymethylated glycoluril, butoxymethylated glycoluril, methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguanamine, butoxymethylated benzoguanamine, methoxymethylated urea, butoxymethylated urea, methoxymethylated thiourea or methoxymethylated thiourea. Further, condensates of these compounds can also be used.
As further light absorbers, commercially available light absorbers described in, for example, "workers dye と (technical and commercial for industrial pigments)", "CMC publishing", "dyes list (overview of dyes)" (eds. organic synthesis chemical association), such as c.i. disperse yellow 1,3, 4, 5, 7, 8, 13, 23, 31, 49, 50, 51, 54, 60, 64, 66, 68, 79, 82, 88, 90, 93, 102, 114 and 124; c.i. disperse oranges 1, 5, 13, 25, 29, 30, 31, 44, 57, 72, and 73; c.i. disperse reds 1, 5, 7, 13, 17, 19, 43, 50, 54, 58, 65, 72, 73, 88, 117, 137, 143, 199, and 210; c.i. disperse violet 43; c.i. disperse blue 96; c.i. fluorescent whitening agents 112, 135 and 163; c.i. solvent orange 2 and 45; c.i. solvent red 1,3, 8, 23, 24, 25, 27 and 49; c.i. pigment green 10; c.i. pigment brown 2, etc. The light absorber is usually contained in an amount of 10% by mass or less, preferably 5% by mass or less, based on the total solid content of the resist underlayer film forming composition for lithography.
The rheology modifier is added mainly for the purpose of improving the fluidity of the composition for forming a resist underlayer film, particularly improving the film thickness uniformity of the resist underlayer film in the baking step and improving the filling property of the composition for forming a resist underlayer film into the holes. Specific examples thereof include phthalic acid derivatives such as dimethyl phthalate, diethyl phthalate, diisobutyl phthalate, dihexyl phthalate and butylisodecyl phthalate, adipic acid derivatives such as di-n-butyl adipate, diisobutyl adipate, diisooctyl adipate and octyldecyl adipate, maleic acid derivatives such as di-n-butyl maleate, diethyl maleate and dinonyl maleate, oleic acid derivatives such as methyl oleate, butyl oleate and tetrahydrofurfuryl oleate, and stearic acid derivatives such as n-butyl stearate and glyceryl stearate. These rheology control agents are usually incorporated in a proportion of less than 30% by mass relative to the total solid content of the resist underlayer film forming composition for lithography.
The adhesion auxiliary agent is added mainly for the purpose of improving the adhesion between the substrate or resist and the resist underlayer film forming composition, and particularly for the purpose of preventing the resist from peeling off during development. Specific examples thereof include chlorosilanes such as trimethylchlorosilane, dimethylvinylchlorosilane, methyldiphenylchlorosilane and chloromethyldimethylchlorosilane, alkoxysilanes such as trimethylmethoxysilane, dimethyldiethoxysilane, methyldimethoxysilane, dimethylvinylethoxysilane, diphenyldimethoxysilane and phenyltriethoxysilane, silazanes such as hexamethyldisilazane, N' -bis (trimethylsilyl) urea, dimethyltrimethylsilylamine and trimethylsilylimidazole, silanes such as vinyltrichlorosilane, gamma-chloropropyltrimethoxysilane, gamma-aminopropyltriethoxysilane and gamma-glycidoxypropyltrimethoxysilane, benzotriazole, benzimidazole, indazole, imidazole, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, dimethylvinylchlorosilane, dimethylvinylmethoxysilane, dimethyldichlorosilane, dimethylglycidoxypropyltrimethoxysilane and the like, and the like, 2-mercaptobenzols
The resist underlayer film forming composition for lithography of the present invention may contain a surfactant in order to further improve coatability to uneven surfaces without causing pinholes, streaks, etc. Examples of the surfactant include nonionic surface surfactants such as polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether and polyoxyethylene oleyl ether, polyoxyethylene alkylaryl ethers such as polyoxyethylene octylphenol ether and polyoxyethylene nonylphenol ether, polyoxyethylene-polyoxypropylene block copolymers, sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate and sorbitan tristearate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate and polyoxyethylene sorbitan tristearate An active agent, エフトツプ EF301, EF303, EF352 (trade name, manufactured by Tokuai chemical Co., Ltd.), (trade name, manufactured by Tokuai トーケムプロダクツ Co., Ltd.), メガファック F171, F173, R-30 (trade name, manufactured by Dainippon インキ Co., Ltd.), フロラード FC430, FC431 (trade name, manufactured by Sumitomo スリーエム Co., Ltd.), アサヒガード AG710, サーフロン S-382, SC101, SC102, SC103, SC104, SC105, SC106 (trade name, manufactured by Asahi Nitro Co., Ltd.), a fluorine-based surfactant, and an organosiloxane polymer KP341 (manufactured by shin-Etsu chemical Co., Ltd.). The amount of these surfactants to be blended is usually 2.0% by mass or less, preferably 1.0% by mass or less, based on the total solid content of the resist underlayer film forming composition for lithography of the present invention. These surfactants may be added alone, or 2 or more of them may be added in combination.
In the resist underlayer film forming composition of the present invention, as a solvent for dissolving the resin, the crosslinking agent component, the crosslinking catalyst, and the like, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol propyl ether acetate, toluene, xylene, methyl ethyl ketone, cyclopentanone, cyclohexanone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl glycolate, methyl 2-hydroxy-3-methylbutyrate, methyl 3-methoxypropionate, ethyl acetate, methyl acetate, ethyl acetate, methyl, Ethyl 3-ethoxypropionate, methyl pyruvate, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, and the like. These organic solvents may be used alone, or in combination of 2 or more.
Further, a high boiling point solvent such as propylene glycol monobutyl ether, propylene glycol monobutyl ether acetate, or the like may be used in combination. Of these solvents, propylene glycol monomethyl ether acetate, ethyl lactate, butyl lactate, cyclohexanone, and the like are preferable for improving leveling property.
The resist used in the present invention is a photoresist or an electron beam resist.
As the photoresist applied on the upper portion of the resist underlayer film for lithography in the present invention, either negative or positive type can be used, and there are: a positive photoresist comprising a novolak resin and a 1, 2-naphthoquinone diazosulfonate ester; a chemically amplified photoresist containing a binder having a group whose alkali dissolution rate is increased by acid decomposition and a photoacid generator; a chemically amplified photoresist comprising an alkali-soluble binder, a low-molecular compound which is decomposed by an acid and increases the alkali dissolution rate of the photoresist, and a photoacid generator; a chemically amplified photoresist containing a binder having a group whose alkali dissolution rate is increased by acid decomposition, a low-molecular compound whose alkali dissolution rate is increased by acid decomposition, and a photoacid generator; examples of the photoresist having an Si atom in the skeleton include those manufactured by ロームアンドハーツ under the trade name APEX-E.
Examples of the electron beam resist to be applied on the upper portion of the resist underlayer film for lithography according to the present invention include a composition comprising a resin having an Si — Si bond in the main chain and an aromatic ring at the end and an acid generator that generates an acid by irradiation of an electron beam, a composition comprising poly (p-hydroxystyrene) having a hydroxyl group substituted with an organic group containing N-carboxyamine and an acid generator that generates an acid by irradiation of an electron beam, and the like. In the latter electron beam resist composition, an acid generated from an acid generator by electron beam irradiation reacts with an N-carboxyamidoxy group of a polymer side chain, the polymer side chain is decomposed into a hydroxyl group to exhibit alkali solubility, and the hydroxyl group is dissolved in an alkali developer to form a resist pattern. Examples of the acid generator that generates an acid by irradiation with an electron beam include 1, 1-bis [ p-chlorophenyl ] amine]-2,2, 2-trichloroethane, 1-bis [ p-methoxyphenyl ] amine]-2,2, 2-trichloroethane, 1-bis [ p-chlorophenyl ]]Halogenated organic compounds such as-2, 2-dichloroethane and 2-chloro-6- (trichloromethyl) pyridine, triphenylsulfonium salts and diphenyliodonium salts
As the developer of the resist having the resist underlayer film formed using the resist underlayer film forming composition for lithography of the present invention, an aqueous solution of a base such as an inorganic base such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, or aqueous ammonia, a primary amine such as ethylamine or n-propylamine, a secondary amine such as diethylamine or di-n-butylamine, a tertiary amine such as triethylamine or methyldiethylamine, an alcohol amine such as dimethylethanolamine or triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, or a quaternary ammonium salt such as choline, or a cyclic amine such as pyrrole or piperidine may be used. In addition, an appropriate amount of an alcohol such as isopropyl alcohol, a nonionic surfactant, or the like may be added to the alkali aqueous solution. Among them, the developer is preferably a quaternary ammonium salt, and more preferably tetramethylammonium hydroxide and choline.
Next, a resist pattern forming method of the present invention will be described, in which a resist underlayer film forming composition is applied to a substrate (for example, a transparent substrate such as a silicon/silicon dioxide-coated substrate, a glass substrate, and an ITO substrate) used for manufacturing a precision integrated circuit element by an appropriate application method such as a spin coater or a coater, and then baked to be cured to form a coating type underlayer film. Here, the film thickness of the resist underlayer film is preferably 0.01 to 3.0 μm. In addition, the baking condition after coating is 0.5-120 minutes at 80-350 ℃. Then, a resist is applied directly on the resist underlayer film, or after 1 to a plurality of layers of coating materials are formed on the coating type underlayer film as necessary, the resist is applied, and then, development, rinsing and drying are performed by irradiation with light or electron beams through a predetermined mask, whereby a favorable resist pattern can be obtained. Post-irradiation with light or an electron beam may be followed by heating (PEB) as required. Then, the resist underlayer film at the portion where the resist has been removed by development in the above-described step may be removed by dry etching to form a desired pattern on the substrate.
The exposure light for the photoresist is a chemical beam such as near ultraviolet, far ultraviolet, or ultra ultraviolet (e.g., EUV, wavelength 13.5nm), and for example, 248nm (KrF laser), 193nm (ArF laser), or 157nm (F laser) can be used2Laser) and the like. When the photo-irradiation is carried out, the photo-irradiation can be carried out by any method as long as the photo-acid generator can generate an acid, and the exposure amount is 1 to 2000mJ/cm2Or 10 to 1500mJ/cm2Or 50 to 1000mJ/cm2。
Further, electron beam irradiation of the electron beam resist may be performed using, for example, an electron beam irradiation apparatus.
In the present invention, a semiconductor device can be manufactured through the following steps: a step of forming a resist underlayer film on a semiconductor substrate using the resist underlayer film forming composition of the present invention; forming a resist film on the resist underlayer film; a step of forming a resist pattern by irradiation with light or an electron beam and development; etching the resist underlayer film through the formed resist pattern; and processing the semiconductor substrate through the patterned resist underlayer film.
In the future, if the miniaturization of resist patterns is advanced, problems such as resolution and collapse of resist patterns after development will occur, and therefore, it is desired to make resists thinner. Therefore, it is difficult to obtain a sufficient resist pattern film thickness for processing a substrate, and a process for providing not only a resist pattern but also a resist underlayer film formed between a resist and a semiconductor substrate to be processed with a function as a mask for substrate processing is required. As a resist underlayer film for such a process, unlike a conventional high etching rate resist underlayer film, a resist underlayer film for lithography having a selection ratio of a dry etching rate close to that of a resist, a resist underlayer film for lithography having a selection ratio of a dry etching rate smaller than that of a resist, and a resist underlayer film for lithography having a selection ratio of a dry etching rate smaller than that of a semiconductor substrate are required. Further, such a resist underlayer film can be provided with antireflection capability, and can also function as a conventional antireflection film.
On the other hand, in order to obtain a fine resist pattern, a process has also been started in which the resist pattern and the resist underlayer film are made finer than the pattern width at the time of resist development at the time of dry etching of the resist underlayer film. As a resist underlayer film for such a process, a resist underlayer film having a selection ratio of a dry etching rate close to that of a resist is required, unlike a conventional high etching rate anti-reflection film. Further, such a resist underlayer film can be provided with antireflection capability, and can also function as a conventional antireflection film.
In the present invention, the resist underlayer film of the present invention is formed on a substrate, and then a resist is directly applied to the resist underlayer film, or a resist is applied after 1 to several layers of coating materials are formed on the resist underlayer film as required. This narrows the pattern width of the resist, and allows the substrate to be processed by selecting an appropriate etching gas even when the resist is thinly coated to prevent pattern collapse.
That is, the semiconductor device can be manufactured through the following steps: forming a resist underlayer film on a semiconductor substrate using the resist underlayer film forming composition; a step of forming a hard mask made of a coating material containing a silicon component or the like or a hard mask (e.g., silicon oxynitride) made by vapor deposition on the resist underlayer film; then forming a resist film on the hard mask; a step of forming a resist pattern by irradiation with light or an electron beam and development; etching the hard mask with a halogen-based gas through the formed resist pattern; etching the resist underlayer film through the patterned hard mask using an oxygen-based gas or a hydrogen-based gas; and processing the semiconductor substrate with a halogen-based gas through the patterned resist underlayer film.
In consideration of the effect of the resist underlayer film forming composition for lithography of the present invention as an antireflection film, since the light absorbing part is introduced into the skeleton, there is no diffusing substance to the photoresist at the time of heat drying, and further, since the light absorbing part has a sufficiently large light absorbing property, the effect of preventing reflected light is high.
The resist underlayer film forming composition for lithography of the present invention has high thermal stability, can prevent contamination of the underlayer film by decomposition products during firing, and can make the temperature margin in the firing step have a margin.
Further, the resist underlayer film forming composition for lithography of the present invention can be used as a film having a function of preventing light reflection, a function of preventing interaction between a substrate and a photoresist, a function of preventing adverse effects on a substrate of a material used in a photoresist or a substance generated when a photoresist is exposed, depending on process conditions.
Furthermore, the present invention relates to a novel compound represented by the following formula (5),
(in the formula, Q3Represents an isopropylidene (-C (CH)3)2-)，R14Represents an alkyl group having 2 to 10 carbon atoms or an alkyl group having 2 to 10 carbon atoms and having an alkoxy group having 1 to 10 carbon atoms, R15Represents a hydrogen atom or a methyl group, R13Represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 40 carbon atoms.
n17 represents an integer of 1. ltoreq. n 17. ltoreq.3, n18 represents an integer of 1. ltoreq. n 18. ltoreq.4, n19 represents an integer of 0. ltoreq. n 19. ltoreq.3, n20 represents an integer of 0. ltoreq. n 20. ltoreq.3, and 2. ltoreq. n17+ n18+ n19+ n 20. ltoreq.5. ).
The alkyl group, alkoxy group and aryl group are exemplified above.