Coating composition for uneven substrates containing a polyether resin having a photocrosslinking group

Abstract

To provide a stepped substrate coating composition which forms a coating film on a substrate, the coating film being highly filling patterns, being able to form a coating film by photo-curing, having a flattening property, and acquiring high heat resistance after light irradiation.SOLUTION: A photocurable stepped substrate coating composition comprises a polymer containing structural units of Formula (1). (In formula (1), A1, A2, and A3 each independently represent a C6-100 aromatic ring which may contain a hetero atom or a hydrocarbon group containing a C6-100 aromatic ring which may contain a hetero atom, and B1, B2, and B3 each independently represent a group having an unsaturated double bond of a specific structure.)SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a coating composition for uneven substrates for forming a planarized film on a substrate having steps by photocrosslinking, and a method for producing a planarized laminated substrate using the coating composition for uneven substrates. [Background technology]

[0002] In recent years, semiconductor integrated circuit devices have been fabricated to meet increasingly fine design rules, and in order to form finer resist patterns using photolithography technology, it is necessary to shorten the exposure wavelength. However, as the exposure wavelength becomes shorter, the depth of focus decreases, making it necessary to improve the planarization of the coating formed on the substrate. In order to manufacture semiconductor devices with fine design rules, flattening technology on the substrate is becoming increasingly important. A method for forming a planarizing film, for example a resist underlayer film formed under a resist, by photocuring is disclosed.

[0003] A resist underlayer film-forming composition containing a polymer having an epoxy group or an oxetane group in a side chain and a photocationic polymerization initiator, or a resist underlayer film-forming composition containing a polymer having a radically polymerizable ethylenically unsaturated bond and a photoradical polymerization initiator has been disclosed (see Patent Document 1).

[0004] Also disclosed is a resist underlayer film-forming composition that contains a silicon-based compound having a cationic polymerizable reactive group such as an epoxy group or a vinyl group, a photocationic polymerization initiator, and a photoradical polymerization initiator (see Patent Document 2).

[0005] Also disclosed is a method for manufacturing a semiconductor device using a resist underlayer film containing a polymer having a crosslinkable functional group (such as a hydroxyl group) in the side chain, a crosslinking agent, and a photoacid generator (see Patent Document 3).

[0006] In addition, although they are not photocrosslinkable resist underlayer films, resist underlayer films having unsaturated bonds in the main chain or side chain have been disclosed (see Patent Documents 4 and 5). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication No. 2006 / 115044 Brochure [Patent Document 2] International Publication No. 2007 / 066597 Brochure [Patent Document 3] International Publication No. 2008 / 047638 Brochure [Patent Document 4] International Publication No. 2009 / 008446 Brochure [Patent Document 5] Special Publication No. 2004-533637 Summary of the Invention [Problem to be solved by the invention]

[0008] In conventional photocrosslinking materials, in resist underlayer film-forming compositions containing a polymer having a thermal crosslinking functional group such as a hydroxyl group, a crosslinking agent, and an acid catalyst (acid generator), a crosslinking reaction proceeds when heated to fill a pattern (e.g., a hole or trench structure) formed on a substrate, causing an increase in viscosity, which makes filling into the pattern problematic. In addition, thermal shrinkage due to degassing causes planarization problems.

[0009] In addition, it is possible to form a polymer having a cationic polymerizable reactive group such as an epoxy group or a vinyl group and an acid generating group. In the case of a resist underlayer film forming composition containing a photoresist, light irradiation and heating are performed, and in that case, thermal shrinkage due to degassing occurs, which causes a problem in planarization.

[0010] The photocurable coating composition for coating uneven substrates of the present invention provides a coating film having planarizing properties that has high filling ability into patterns and can be formed into a coating film by photocuring without causing degassing or thermal shrinkage, and that is capable of forming a coating film with high heat resistance on a substrate after irradiation with light. [Means for solving the problem]

[0011] In a first aspect, the present invention provides a compound represented by the formula (1): [ka] [In formula (1), A 1 , A 2 and A 3 each independently represents an aromatic ring having 6 to 100 carbon atoms which may contain a heteroatom or a hydrocarbon group containing an aromatic ring having 6 to 100 carbon atoms which may contain a heteroatom; B 1 , B 2 and B. 3 are each independently represented by the formula (2): [ka] (In formula (2), R 1 is an alkylene group having 1 to 10 carbon atoms, an alkenylene group having 1 to 10 carbon atoms, an alkynylene group having 1 to 10 carbon atoms, an arylene group having 6 to 40 carbon atoms (the alkylene group, alkenylene group, alkynylene group and arylene group may be optionally substituted with one or more cyano groups and / or one or more hydroxyl groups), an oxygen atom, a carbonyl group, a sulfur atom, -C(O)-O-, -C(O)-NR a -, -NR b - or a combination thereof; R a represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; R b represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkylcarbonyl group having 2 to 10 carbon atoms; R 2 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and the dotted line represents A 1 , A 2, or A 3 ) and X is a carbonyl group, a sulfonyl group, -CR 2 2 - group, or -C(CF 3 ) 2 -group, n1 is an integer satisfying 1≦n1≦4, n2 is an integer satisfying 0≦n2≦4, and n3 is an integer satisfying 0≦n3≦4, and n1+n2+n3=an integer satisfying 1 to 12;

[0012] As the second viewpoint, A 1 is represented by the formula (1-1) or the formula (1-2): [ka] (However, in formula (1-1) and formula (1-2), T 1 are each independently a halogen group, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 18 carbon atoms, an arylalkyl group having 7 to 28 carbon atoms, an alkylcarbonyl group having 2 to 10 carbon atoms, an alkylcarbonyloxy group having 2 to 10 carbon atoms, an alkylcarbonylamino group having 2 to 10 carbon atoms, an aryloxyalkyl group having 7 to 28 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an organic group consisting of a combination thereof; q is an integer of 2 to 6, and when q is 2, T 2 represents a single bond, a divalent hydrocarbon group having 1 to 10 carbon atoms which may have a hydroxyl group, or a divalent arylalkyl group having 7 to 28 carbon atoms which may have a hydroxyl group; when q is 3 to 6, T 2 represents a trivalent to hexavalent hydrocarbon group having 1 to 10 carbon atoms which may have a hydroxyl group, or a trivalent to hexavalent arylalkyl group having 7 to 28 carbon atoms which may have a hydroxyl group, m is an integer of 1 to 7, n is an integer satisfying 0≦n≦7−m, and two T 2 may form a ring together, and p is an integer of 0 or 1. In the polynuclear phenol represented by the formula (I), two of the m×q hydroxyl groups are represented by the formula (I). 1and the remaining hydroxyl groups among the m×q hydroxyl groups in the polynuclear phenol and / or T 2 The hydrogen atom of A 1 B in 1 It becomes a combination with B 1 the total number of bonds bonded to

[0013] As the third perspective, A 1 is a group derived from tri(hydroxyphenyl)methane, a group derived from tetrakis(hydroxyphenyl)ethane, or a group derived from tetrakis(hydroxyphenyl)-p-xylene, and A 2 and A 3 is a group derived from a benzene ring or a naphthalene ring;

[0014] as a fourth aspect, the photocurable composition for covering an uneven substrate according to any one of the first to third aspects, in which X is a carbonyl group;

[0015] As a fifth aspect, the photocurable composition for covering uneven substrates according to the first aspect, which is a polymer including a unit structure of formula (1) in which n1 is 1 or 2, and n2 and n3 are 0;

[0016] As a sixth aspect, the polymer further comprises a unit structure of the formula (3): [ka] (In formula (3), A 4 and A 5 each represents an aromatic ring having 6 to 48 carbon atoms which may contain a heteroatom, or a hydrocarbon group containing an aromatic ring having 6 to 48 carbon atoms which may contain a heteroatom; B 4 and B. 5 is B in the above formula (2) 1 , B 2 and B. 3wherein n4 is an integer of 1≦n4≦4, n5 is an integer of 0≦n5≦4, and n4+n5=an integer of 1 to 8.

[0017] As a seventh aspect, the photocurable composition for covering stepped substrates according to any one of the first to sixth aspects, wherein the polymer further comprises a unit structure of formula (1') in which n1 = 0, n2 = 0, and n3 = 0 in formula (1) in addition to the unit structures of formula (1) and formula (3);

[0018] As an eighth aspect, the photocurable uneven substrate coating composition according to any one of the first to seventh aspects, wherein the uneven substrate coating composition is a resist underlayer film forming composition used in a lithography step of manufacturing a semiconductor device;

[0019] As a ninth aspect, a method for producing a coated substrate, the method comprising: a step (i) of applying the photocurable uneven substrate coating composition according to any one of the first to eighth aspects to a substrate having a step; and a step (ii) of exposing the substrate to light.

[0020] As a tenth aspect, the method for producing a coated substrate according to the ninth aspect further comprises a step (ia) of heating at a temperature of 70 to 400° C. for 10 seconds to 5 minutes after applying the photocurable step-like substrate coating composition in the step (i);

[0021] As an eleventh aspect, the method for producing a coated substrate according to the eighth or tenth aspect, wherein the exposure wavelength in the step (ii) is 150 nm to 248 nm;

[0022] According to a twelfth aspect, the exposure dose in step (ii) is 10 mJ / cm 2 ~3000mJ / cm 2 The method for producing a coated substrate according to any one of the ninth to eleventh aspects,

[0023] As a thirteenth aspect, the method for producing a coated substrate according to any one of the ninth to twelfth aspects, in which the substrate has an open area (non-pattern area) and a pattern area of ​​DENCE (dense) and ISO (sparse), and the aspect ratio of the pattern is 0.1 to 10;

[0024] As a fourteenth aspect, there is provided a method for producing a coated substrate according to the thirteenth aspect, in which a bias (a coating step) between the open area and the pattern area is 1 to 50 nm.

[0025] As a fifteenth aspect, a step of forming an underlayer film on a substrate having a step using the stepped substrate coating composition according to any one of the first to eighth aspects, and a step of forming a resist film thereon. A method for manufacturing a semiconductor device, comprising the steps of forming a resist pattern by irradiating a resist with light or an electron beam and developing the resist pattern, etching the underlayer film with the resist pattern, and processing a semiconductor substrate with the patterned underlayer film; and

[0026] As a sixteenth aspect, there is provided a method for manufacturing a semiconductor device, the method including the steps of forming an underlayer film on a substrate having steps from the photocurable uneven substrate coating composition according to any one of the first to eighth aspects, forming a hard mask thereon, forming a resist film thereon, forming a resist pattern by exposure to light or an electron beam and development, etching the hard mask with the resist pattern, etching the underlayer film with the patterned hard mask, and processing a semiconductor substrate with the patterned underlayer film. Effect of the Invention

[0027] In the present invention, the composition is applied onto a substrate and, in some cases, filled into a pattern by reflowing under heating. During this process, the composition does not have a thermal crosslinking site or an acid catalyst, so there is no increase in viscosity of the composition for coating uneven substrates, and a flat film is formed regardless of whether the composition is an open area (non-pattern area) on the substrate or a pattern area of ​​DENCE (dense) or ISO (sparse). Then, a crosslinked structure between unsaturated bonds is formed by radical species by light irradiation of the carbon-carbon unsaturated bond. The composition for coating uneven substrates of the present invention does not contain a crosslinking agent or an acid catalyst, and the coating film for uneven substrates (flattening film) formed by applying the composition for coating uneven substrates can be crosslinked by a reaction between double bonds derived from the unsaturated bonds of carbon and carbon.

[0028] The coating film (flattening film) for uneven substrates made from the coating composition for uneven substrates of the present invention does not undergo a crosslinking reaction due to a crosslinking agent and an acid catalyst during thermal reflow, and the subsequent photocrosslinking is a photoreaction that does not involve degassing, so no thermal shrinkage occurs. This makes it possible to simultaneously satisfy both the ability to fill the pattern and the ability to flatten after filling, thereby forming an excellent flattening film.

[0029] The photocurable coating composition for uneven substrates of the present invention has high filling properties for patterns, and is capable of forming a coating film having planarizing properties by photocuring without causing degassing or thermal shrinkage, and is capable of forming a coating film having high heat resistance on a substrate after light irradiation. Even when a high-temperature hard mask layer is formed on the photocurable coating film for uneven substrates, the composition has sufficient heat resistance. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] The present invention is a photocurable coating composition for uneven substrates, comprising a polymer containing a unit structure of formula (1).

[0031] In formula (1), A 1 , A 2 and A 3 each independently represents an aromatic ring having 6 to 100 carbon atoms which may contain a heteroatom or a hydrocarbon group containing an aromatic ring having 6 to 100 carbon atoms which may contain a heteroatom; B 1 , B2 and B. 3 each independently represents the formula (2), and X represents a carbonyl group, a sulfonyl group, -CR 2 2 - group, or -C(CF 3 ) 2 - group, R 2 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, n1 is an integer satisfying 1≦n1≦4, n2 is an integer satisfying 0≦n2≦4, and n3 is an integer satisfying 0≦n3≦4, where n1+n2+n3=an integer of 1 to 12. Examples of heteroatoms include nitrogen atoms and oxygen atoms.

[0032] In the above-mentioned hydrocarbon group containing an aromatic ring having 6 to 100 carbon atoms, examples of the hydrocarbon group include hydrocarbon groups derived from the following alkyl groups.

[0033] Examples of the aromatic ring having 6 to 100 carbon atoms include a benzene ring, a biphenyl ring, a terphenylene ring, a fluorene ring, a naphthalene ring, an anthryl ring, a pyrene ring, a carbazole ring, and an indole ring.

[0034] In formula (2), R 1 is an alkylene group having 1 to 10 carbon atoms, an alkenylene group having 1 to 10 carbon atoms, an alkynylene group having 1 to 10 carbon atoms, an arylene group having 6 to 40 carbon atoms (the alkylene group, alkenylene group, alkynylene group and arylene group may be optionally substituted with one or more cyano groups and / or one or more hydroxyl groups), an oxygen atom, a carbonyl group, a sulfur atom, -C(O)-O-, -C(O)-NR a -, -NR b - or a combination thereof; R 2 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and the dotted line represents A 1 , A 2 , or A 3 This shows the bond with However, R 1 In the formula, oxygen atom, carbonyl group, sulfur atom, -C(O)-O-, -C(O)-NR a - and -NR b- do not bond with each other.

[0035] Above A 1 can represent, for example, a group derived from a polynuclear phenol represented by formula (1-1) or formula (1-2). The polynuclear phenol has at least three hydroxyl groups, and preferably has 3 to 6, or 3 to 5, or 3 to 4 hydroxyl groups. Here, the number of hydroxyl groups possessed by the polynuclear phenol means m×q.

[0036] A 1 is a group obtained by removing two hydroxyl groups from the m × q hydroxyl groups of the polynuclear phenol. For example, the unit structure of formula (1) can be formed by introducing a functional group of formula (2) into the remaining hydroxyl group of the polymer formed by dehydrohalogenation of two of the m × q hydroxyl groups of the polynuclear phenol with a dihalogenated diaryl group containing an X moiety. At that time, the hydroxyl group in the polymer can be subjected to an addition reaction with an unsaturated group-containing epoxy compound such as allyl glycidyl ether, glycidyl acrylate, or glycidyl methacrylate to form a polymer having the unit structure of formula (1).

[0037] Alternatively, the hydroxyl groups in the polymer can be reacted with an allyl halide (eg, allyl bromide, allyl chloride) to form a polymer having the unit structure of formula (1).

[0038] In addition, the hydroxyl groups in the polymer can be epoxidized with an epoxy compound such as epichlorohydrin, and then reacted with an unsaturated carboxylic acid corresponding to formula (2) (e.g., acrylic acid, methacrylic acid) to form a polymer having the unit structure of formula (1).

[0039] A 1 In the polynuclear phenol represented by formula (1-1) or formula (1-2) for constituting 1are each independently a halogen group, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 18 carbon atoms, an arylalkyl group having 7 to 28 carbon atoms, an alkylcarbonyl group having 2 to 10 carbon atoms, an alkylcarbonyloxy group having 2 to 10 carbon atoms, an alkylcarbonylamino group having 2 to 10 carbon atoms, an aryloxyalkyl group having 7 to 28 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an organic group consisting of a combination thereof; q is an integer of 2 to 6, and when q is 2, T 2 represents a single bond, a divalent hydrocarbon group having 1 to 10 carbon atoms which may have a hydroxyl group, or a divalent arylalkyl group having 7 to 28 carbon atoms which may have a hydroxyl group; when q is 3 to 6, T 2 represents a trivalent to hexavalent hydrocarbon group having 1 to 10 carbon atoms which may have a hydroxyl group, or a trivalent to hexavalent arylalkyl group having 7 to 28 carbon atoms which may have a hydroxyl group, m is an integer of 1 to 7, n is an integer satisfying 0≦n≦7−m, and two T 2 may form a ring together, and p is an integer of 0 or 1.

[0040] In the polynuclear phenol represented by formula (1-1) or formula (1-2), two of the m×q hydroxyl groups are 1 The bonds bonded to the two O atoms in and the remaining hydroxyl groups among the m×q hydroxyl groups in the polynuclear phenol and / or T 2 The hydrogen atom of A 1 B in 1 It becomes a combination with B 1 The total number of bonds connecting to is n1.

[0041] Examples of the polynuclear phenol include the following. [ka] [ka] [ka]

[0042] The polymer of formula (1) is A 1 is a group derived from tri(hydroxyphenyl)methane, a group derived from tetrakis(hydroxyphenyl)ethane, or a group derived from tetrakis(hydroxyphenyl)-p-xylene, and A 2 and A 3 has a group derived from a benzene ring or a naphthalene ring, and a group having a tri(hydroxyphenyl)methane structure, a group having a tetrakis(hydroxyphenyl)ethane structure, or a group having a tetrakis(hydroxyphenyl)-p-xylene structure is also preferred. In the formula (1), X is preferably a carbonyl group. In addition, a polymer in which n1 in formula (1) is 1 or 2, and n2 and n3 are 0 can be used. The above-mentioned coating composition for uneven substrates may contain additives such as a surfactant, if necessary.

[0043] The solid content of this composition is 0.1 to 70% by weight, or 0.1 to 60% by weight, or 0.2 to 30% by weight, or 0.3 to 15% by weight. The solid content is the content of all components excluding the solvent from the stepped substrate coating composition. The solid content may contain the above polymer in a ratio of 1 to 100% by weight, or 1 to 99.9% by weight, or 50 to 99.9% by weight, or 50 to 95% by weight, or 50 to 90% by weight. The polymer used in the present invention has an average molecular weight of 600 to 1,000,000, or 600 to 200,000, or 1,500 to 15,000. The above polymers can form crosslinked structures by photoreaction of unsaturated bonds between carbon atoms or within a molecule. At least one of these may be present in the molecule, and multiple of these (eg, 1 to 1000) may also be present in the molecule.

[0044] The alkyl group includes alkyl groups having 1 to 10 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, a cyclopropyl group, an n-butyl group, an i-butyl group, an s-butyl group, a t-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, cyclopentyl, 1-methyl-cyclobutyl, 2-methyl-cyclobutyl, 3-methyl-cyclobutyl, 1,2-dimethyl-cyclopropyl, 2,3-dimethyl-cyclopropyl, 1-ethyl-cyclopropyl, 2-ethyl-cyclopropyl, n-hexyl, 1-methyl-n-pentyl, 2-methyl-n-pentyl, 3-methyl-n-pentyl, 4-methyl-n-pentyl, 1,1-dimethyl-n-butyl, 1,2-dimethyl-n-butyl, 1,3-dimethyl-n- butyl, 2,2-dimethyl-n-butyl, 2,3-dimethyl-n-butyl, 3,3-dimethyl-n-butyl, 1-ethyl-n-butyl, 2-ethyl-n-butyl, 1,1,2-trimethyl-n-propyl, 1,2,2-trimethyl-n-propyl, 1-ethyl-1-methyl-n-propyl, 1-ethyl-2-methyl-n-propyl, cyclohexyl, 1-methyl-cyclopentyl, 2-methyl-cyclopentyl, 3-methyl-cyclopentyl, 1-ethyl-cyclobutyl, 2-ethyl-cyclobutene ethyl, 3-ethyl-cyclobutyl, 1,2-dimethyl-cyclobutyl, 1,3-dimethyl-cyclobutyl, 2,2-dimethyl-cyclobutyl, 2,3-dimethyl-cyclobutyl, 2,4-dimethyl-cyclobutyl, 3,3-dimethyl-cyclobutyl, 1-n-propyl-cyclopropyl, 2-n-propyl-cyclopropyl, 1-i-propyl-cyclopropyl, 2-i-propyl-cyclopropyl, 1,2,2-trimethyl-cyclopropyl, 1,2,3-trimethyl-cyclopropyl, 2,2,Examples of the cyclopropyl group include a 3-trimethylcyclopropyl group, a 1-ethyl-2-methylcyclopropyl group, a 2-ethyl-1-methylcyclopropyl group, a 2-ethyl-2-methylcyclopropyl group, and a 2-ethyl-3-methylcyclopropyl group.

[0045] Examples of the alkylcarbonyl group having 2 to 10 carbon atoms include groups in which each of the alkyl groups enumerated above having 1 to 9 carbon atoms is bonded to a carbonyl group, examples of the alkylcarbonyloxy group having 2 to 10 carbon atoms include groups in which each of the alkyl groups enumerated above having 1 to 9 carbon atoms is bonded to a carbonyloxy group, examples of the alkylcarbonylamino group having 2 to 10 carbon atoms include groups in which each of the alkyl groups enumerated above having 1 to 9 carbon atoms is bonded to a carbonylamino group, and examples of the alkoxy group having 1 to 6 carbon atoms include groups in which each of the alkyl groups enumerated above having 1 to 6 carbon atoms is bonded to an oxygen atom.

[0046] The aryl group is an aryl group having 6 to 40 carbon atoms, such as a phenyl group, a biphenyl group, a terphenylene group, a fluorene group, a naphthyl group, an anthryl group, a pyrene group, and a carbazole group, and the aryl group having 6 to 18 carbon atoms also includes a phenyl group, a biphenyl group, a terphenylene group, a fluorene group, a naphthyl group, an anthryl group, a pyrene group, and a carbazole group.

[0047] Examples of the arylalkyl group having 7 to 28 carbon atoms include those in which the above-mentioned alkyl group having 1 to 10 carbon atoms is substituted with the above-mentioned aryl group having 6 to 18 carbon atoms, and those in which the number of carbon atoms is 7 to 28. Examples of the aryloxyalkyl group having 7 to 28 carbon atoms include those in which the above-mentioned alkyl group having 1 to 10 carbon atoms is substituted with the above-mentioned carbon atom. Among groups in which an aryl group having 6 to 18 carbon atoms is substituted via an oxygen atom, those having 7 to 28 carbon atoms are exemplified.

[0048] The alkenyl group includes alkenyl groups having 1 to 10 carbon atoms, such as ethenyl, 1-propenyl, 2-propenyl, 1-methyl-1-ethenyl, 1-butenyl, 2-butenyl, 3-butenyl, 2-methyl-1-propenyl, 2-methyl-2-propenyl, 1-ethylethenyl, 1-methyl-1-propenyl, 1-methyl-2-propenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4- Examples thereof include a pentenyl group, a 1-n-propylethenyl group, a 1-methyl-1-butenyl group, a 1-methyl-2-butenyl group, a 1-methyl-3-butenyl group, a 2-ethyl-2-propenyl group, a 2-methyl-1-butenyl group, a 2-methyl-2-butenyl group, a 2-methyl-3-butenyl group, a 3-methyl-1-butenyl group, a 3-methyl-2-butenyl group, a 3-methyl-3-butenyl group, a 1,1-dimethyl-2-propenyl group, and a 1-i-propylethenyl group.

[0049] The alkynyl group includes alkynyl groups having 1 to 10 carbon atoms, such as ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-methyl-2-propynyl, 1-pentynyl, 2-pentynyl, 3-pentynyl, 4-pentynyl, 1-methyl-2-butynyl, 1-methyl-3-butynyl, 2-methyl-3-butynyl, 3-methyl-1-butynyl, 1,1-dimethyl-2-propynyl, 2-ethyl-2-propynyl, 1-hexynyl, 2-hexynyl, 3-hexynyl, 4-hexynyl, 5-hexynyl, 1-methyl-2-pentynyl, 1-methyl-3-pentynyl, and 1-methyl-4-pentynyl.

[0050] The alkylene group is exemplified by a divalent organic group derived from the alkyl group. The arylene group is exemplified by a divalent organic group derived from the aryl group. The alkenylene group is exemplified by a divalent organic group derived from the alkenyl group. The alkynylene group is exemplified by a divalent organic group derived from the alkynyl group.

[0051] The polymer may further contain a unit structure of formula (3) in addition to the unit structure of formula (1). In formula (3), A 4 and A 5 each represents an aromatic ring having 6 to 48 carbon atoms which may contain a heteroatom or a hydrocarbon group containing an aromatic ring having 6 to 48 carbon atoms which may contain a heteroatom; B 4 and B. 5 is the same as the above formula (2), n4 is an integer of 1≦n4≦4, n5 is an integer of 0≦n5≦4, and n4+n5=an integer of 1 to 8. Examples of heteroatoms include nitrogen atoms and oxygen atoms. Examples of aromatic rings having 6 to 48 carbon atoms include a benzene ring, a biphenyl ring, a terphenylene ring, a fluorene ring, a naphthalene ring, an anthryl ring, a pyrene ring, a carbazole ring, and an indole ring.

[0052] In the above-mentioned hydrocarbon group containing an aromatic ring having 6 to 48 carbon atoms, examples of the hydrocarbon group include those derived from the above-mentioned alkyl groups. When the polymer contains the unit structure of formula (1) and the unit structure of formula (3), the unit structure of formula (1):the unit structure of formula (3) may be contained in a molar ratio of 1:0.1 to 1:10, or 1:0.5 to 1:5, or 1:1.

[0053] Examples of the polymers that can be used in the present invention include the following. [ka] [ka] [ka] [ka] [ka] [ka]

[0054] The aforementioned A 1 , A 2 , A 3 , A 4 , A 5 , B 1 , B 2 , B 3 , B 4 and T 2 is expressed in terms of the polymers represented by the above formulas (1-4-1) to (1-4-12) as follows: [ka] [ka] [ka] [ka] [ka] [ka]

[0055] The step-like substrate coating composition of the present invention may contain a surfactant. Examples of the surfactant include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oleyl ether, polyoxyethylene alkylaryl ethers such as polyoxyethylene octylphenyl ether and polyoxyethylene nonylphenyl 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. Examples of the surfactant include nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters such as stearates, F-top (registered trademark) EF301, EF303, and EF352 (manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.), Megafac (registered trademark) F171, F173, R30, R40, R-30N, and R-40LM (manufactured by DIC Corporation), Fluorad FC430 and FC431 (manufactured by Sumitomo 3M Limited), Asahiguard (registered trademark) AG710, Surflon (registered trademark) S-382, SC101, SC102, SC103, SC104, SC105, and SC106 (manufactured by Asahi Glass Co., Ltd.), and organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.). One of these surfactants may be added, or two or more of them may be added in combination. The content of the surfactant is, for example, 0.01 to 5% by mass based on the solid content excluding the solvent described below from the stepped substrate covering composition of the present invention.

[0056] Examples of the solvent for dissolving the polymer in the present invention include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monoisopropyl ether, ethylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monoethyl ether acetate, propylene glycol, propylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether, propylene glycol monoethyl ether acetate, propylene glycol propyl ether acetate, dipropylene glycol glycol monomethyl ether, dipropylene glycol monoethyl ether, triethylene glycol dimethyl ether, toluene, xylene, styrene, methyl ethyl ketone, cyclopentanone, cyclohexanone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, 1-octanol, ethylene glycol, hexylene glycol, trimethylene glycol, 1-methoxy-2-butanol, cyclohexanol, diacetone alcohol, furfuryl alcohol, tetrahydrofurfuryl alcohol, propylene glycol, benzyl alcohol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, γ-butyrolactone, acetone, methyl isopropyl ketone, diethyl ketone, methyl isobutyl ketone, methyl normal butyl ketone, isopropyl acetate ketone, normal propyl acetate, isobutyl acetate, methanol, ethanol, isopropanol, tert-butanol, allyl alcohol, normal propanol, 2-methyl-2-butanol, isobutanol, normal butanol, 2-methyl-1-butanol, 1-pentanol, 2-methyl-1-pentanol, 2-ethylhexanol, 1- Octanol, ethylene glycol, hexylene glycol, trimethylene glycol, 1-methoxy-2-butanol, diacetone alcohol, furfuryl alcohol, tetrahydrofurfuryl alcohol, propylene glycol, benzyl alcohol, isopropyl ether, 1,4-dioxane, N,N-dimethyltetramamide, N,N-dimethylacetamide, N-methylpyrrolidone, 1,3-dimethyl-2-imidazolidinone, dimethyl sulfoxide, N-cyclohexyl-2-pyrrolidinone, etc. can be used. These organic solvents can be used alone or in combination of two or more.

[0057] Next, a method for forming a planarizing film using the step substrate coating composition of the present invention will be described. The planarizing film is applied to a substrate (e.g., a silicon / silicon dioxide coated, glass substrate) used in the manufacture of precision integrated circuit elements. The coating composition is applied onto a substrate having a stepped portion (e.g., a transparent substrate such as an ITO substrate) by a suitable coating method such as a spinner or coater, and then the substrate is baked (heated) and exposed to light to produce a coating film. That is, the coated substrate is produced by the process comprising the steps of (i) applying the coating composition onto a substrate having a stepped portion, and (ii) exposing the substrate to light.

[0058] When coating is carried out using a spinner, coating can be carried out, for example, at a rotation speed of 100 to 5,000 for 10 to 180 seconds. The substrate has open areas (non-patterned areas) and patterned areas of DENCE (dense) and ISO (coarse), and pattern aspect ratios of 0.1 to 10 can be used.

[0059] A non-patterned area refers to a portion of the substrate that does not have a pattern (e.g., a hole or trench structure), a DENCE (dense) area refers to a portion of the substrate where patterns are densely packed, and an ISO (coarse) area refers to a portion of the substrate where patterns are widely spaced and scattered. The aspect ratio of a pattern is the ratio of the pattern depth to the pattern width. The pattern depth is usually several hundred nm (e.g., about 100 to 300 nm), and a DENCE (dense) area is an area where patterns of several tens of nm (e.g., 30 to 80 nm) are densely packed at intervals of about 100 nm. An ISO (coarse) area is an area where patterns of several hundred nm (e.g., about 200 to 1000 nm) are scattered.

[0060] Here, the thickness of the uneven substrate coating film (flattening film) is preferably 0.01 to 3.0 μm. In step (ia), the coating may be heated at 70 to 400° C. or 100 to 250° C. for 10 seconds to 5 minutes or 30 seconds to 2 minutes. This heating causes the uneven substrate coating composition to reflow, forming a flat uneven substrate coating film (flattening film).

[0061] In the step (ia), when heating is performed after coating, a crosslinking agent and a crosslinking catalyst can be added. This heating is thermal curing and assists photocrosslinking, and functions effectively when the bottom of the uneven substrate coating composition cannot be sufficiently photocured, but thermal curing can be used in combination within a range that does not affect the deterioration of flattening properties due to degassing caused by thermal curing.

[0062] Examples of the crosslinking agent include melamine-based, substituted urea-based, and polymers thereof. A crosslinking agent having at least two crosslink-forming substituents is preferable, and is a compound such as methoxymethylated glycoluril, butoxymethylated glycoluril, methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguanamine, butoxymethylated benzoguanamine, methoxymethylated urea, butoxymethylated urea, methoxymethylated thiourea, or methoxymethylated thiourea. Condensates of these compounds can also be used. The amount of the crosslinking agent added is 0.001 to 80% by mass, preferably 0.01 to 50% by mass, and more preferably 0.05 to 40% by mass based on the total solid content.

[0063] An acid and / or an acid generator can be added as a catalyst for promoting the crosslinking reaction. For example, acidic compounds such as p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium p-toluenesulfonic acid, salicylic acid, 5-sulfosalicylic acid, 4-phenolsulfonic acid, camphorsulfonic acid, 4-chlorobenzenesulfonic acid, benzenedisulfonic acid, 1-naphthalenesulfonic acid, citric acid, benzoic acid, hydroxybenzoic acid, and naphthalenecarboxylic acid, and / or thermal acid generators such as 2,4,4,6-tetrabromocyclohexadienone, benzoin tosylate, 2-nitrobenzyl tosylate, and other organic sulfonic acid alkyl esters can be blended. The blending amount is 0.0001 to 20% by mass, preferably 0.0005 to 10% by mass, and more preferably 0.01 to 3% by mass, based on the total solid content. Mass percent.

[0064] The exposure light in step (ii) is actinic radiation such as near ultraviolet light, far ultraviolet light, or extreme ultraviolet light (e.g., EUV, wavelength 13.5 nm), and examples of such radiation include 248 nm (KrF laser light), 193 nm (ArF laser light), 172 nm (xenon excimer light), 157 nm (F 2 The light used may be ultraviolet light having a wavelength of 150 nm to 248 nm, and preferably has a wavelength of 172 nm.

[0065] This exposure causes crosslinking of the film covering the stepped substrate (flattening film). The exposure dose in step (ii) is 10 mJ / cm 2 ~3000mJ / cm 2 Within this range of exposure dose, a photoreaction occurs, crosslinking is formed, and solvent resistance is achieved.

[0066] The stepped substrate coating film (flattening film) thus formed preferably has zero bias (coating step) between the open area and the pattern area, but can be flattened to a range of 1 to 50 nm, or 1 to 25 nm. The bias between the open area and the DENCE area is about 15 to 20 nm, and the bias between the open area and the ISO area is about 1 to 10 nm.

[0067] The uneven substrate coating film (flattening film) obtained by the present invention can be coated with a resist film, and the resist film can be exposed and developed by lithography to form a resist pattern, and a substrate can be processed according to the resist pattern. In this case, the uneven substrate coating film (flattening film) is a resist underlayer film, and the uneven substrate coating composition is also a resist underlayer film-forming composition.

[0068] A good resist pattern can be obtained by applying a resist onto the resist underlayer film, irradiating the resist with light or electron beams through a specified mask, developing, rinsing, and drying. If necessary, post-exposure baking (PEB) after irradiation with light or electron beams can also be performed. Then, the resist underlayer film in the portion where the resist has been developed and removed in the above process is removed by dry etching, and a desired pattern can be formed on the substrate.

[0069] The exposure light for the photoresist is actinic radiation such as near ultraviolet, far ultraviolet, or extreme ultraviolet (e.g., EUV, wavelength 13.5 nm), and examples of such radiation include 248 nm (KrF laser light), 193 nm (ArF laser light), 157 nm (F 2The light irradiation may be performed by any method that can generate an acid from the photoacid generator in the resist, without any particular limitation. The exposure dose is 1 to 3000 mJ / cm. 2 , or 10 to 3000 mJ / cm 2 , or 10 to 1000 mJ / cm 2 by.

[0070] The electron beam resist can be irradiated with an electron beam using, for example, an electron beam irradiation device. As a developer for a resist having a resist underlayer film formed using the resist underlayer film material for lithography in the present invention, an aqueous solution of alkalis such as inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and ammonia water, primary amines such as ethylamine and n-propylamine, secondary amines such as diethylamine and di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, quaternary ammonium salts such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline, cyclic amines such as pyrrole and piperidine, etc. can be used. Furthermore, an appropriate amount of alcohols such as isopropyl alcohol and surfactants such as nonionic surfactants can be added to the aqueous solution of the above alkalis. Among these, Preferred developers are quaternary ammonium salts, more preferably tetramethylammonium hydroxide and choline.

[0071] The developer may be an organic solvent.For example, methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, propylene glycol monomethyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether butyl acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, lactate Examples of the isopropyl ester include propyl acetate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, and propyl 3-methoxypropionate.Furthermore, a surfactant may be added to these developers. The development conditions are appropriately selected from a temperature of 5 to 50° C. and a time of 10 to 600 seconds.

[0072] In the present invention, a semiconductor device can be manufactured through the steps of forming a resist underlayer film on a semiconductor substrate using a resist underlayer film-forming composition, forming a resist film thereon, forming a resist pattern by irradiating with light or an electron beam and developing, etching the resist underlayer film with the resist pattern, and processing a semiconductor substrate with the patterned resist underlayer film.

[0073] In the future, as the resist pattern becomes finer, problems such as resolution problems and the collapse of the resist pattern after development will occur, and a thinner resist is desired. Therefore, it is difficult to obtain a resist pattern film thickness sufficient for substrate processing, and a process is required in which not only the resist pattern but also the resist underlayer film formed between the resist and the semiconductor substrate to be processed has the function of a mask during substrate processing. As a resist underlayer film for such a process, unlike the conventional high etch rate resist underlayer film, a resist underlayer film for lithography having a selectivity of a dry etching rate close to that of a resist, a resist underlayer film for lithography having a selectivity of a dry etching rate smaller than that of a resist, and a resist underlayer film for lithography having a selectivity of a dry etching rate smaller than that of a semiconductor substrate are being required. In addition, such a resist underlayer film can also be given antireflection properties, and can also have the function of a conventional antireflection film.

[0074] On the other hand, in order to obtain a fine resist pattern, the resist underlayer film is dry etched. Processes have also begun in which the resist pattern and resist underlayer film are narrower than the pattern width at the time of resist development. As a resist underlayer film for such processes, unlike conventional high etch rate antireflective films, a resist underlayer film having a selectivity ratio of dry etching rate close to that of the resist is now required. In addition, such resist underlayer films can be given antireflective properties, and can have the functions of conventional antireflective films.

[0075] In the present invention, after forming the resist underlayer film of the present invention on a substrate, a resist can be applied directly onto the resist underlayer film, or after forming one or several layers of a coating material on the resist underlayer film as necessary. This narrows the resist pattern width, and even if the resist is thinly coated to prevent pattern collapse, the substrate can be processed by selecting an appropriate etching gas.

[0076] That is, a semiconductor device can be manufactured through the steps of forming a resist underlayer film on a semiconductor substrate using a resist underlayer film forming composition, forming thereon a hard mask using a coating material containing a silicon component or the like or a hard mask by vapor deposition (e.g., silicon oxynitride), forming a resist film on top of that, forming a resist pattern by irradiation with light or an electron beam and development, etching the hard mask using the resist pattern with a halogen-based gas, etching the resist underlayer film using the patterned hard mask with an oxygen-based gas or a hydrogen-based gas, and processing the semiconductor substrate with a halogen-based gas using the patterned resist underlayer film.

[0077] In the resist underlayer film forming composition for lithography of the present invention, when considering the effect as an antireflective film, since the light absorbing moiety is incorporated into the skeleton, no diffusion occurs into the photoresist during heating and drying, and since the light absorbing moiety has sufficiently large light absorption performance, the composition has a high antireflective effect.

[0078] The resist underlayer film forming composition for lithography of the present invention has high thermal stability, can prevent contamination of the upper layer film by decomposition products during baking, and can provide a large temperature margin for the baking step.

[0079] Furthermore, the resist underlayer film material for lithography in the present invention can be used as a film having a function of preventing light reflection, depending on the process conditions, and further a function of preventing interaction between the substrate and the photoresist, or a function of preventing adverse effects on the substrate of materials used in the photoresist or substances generated during exposure of the photoresist. EXAMPLES

[0080] (Synthesis of resin 1) In a three-neck flask, 50.0 g of 1,1,1-tris(4-hydroxyphenyl)ethane (Tokyo Chemical Industry Co., Ltd.), 35.6 g of 4,4-difluorobenzophenone (Tokyo Chemical Industry Co., Ltd.), 31.37 g of potassium carbonate (Wako Pure Chemical Industries, Ltd.), and 272.9 g of N-methylpyrrolidone (Kanto Chemical Co., Ltd.) were placed. The mixture was then heated to 150°C and stirred for about 2.5 hours. After the reaction was completed, the mixture was diluted with 180.8 g of N-methylpyrrolidone, and potassium carbonate was removed by filtration. The filtrate obtained was neutralized by adding 1N-HCl, and then stirred for a while. This diluted solution was dropped into a methanol / water = 90 / 10 (vol / vol) solution to cause reprecipitation. The precipitate obtained was filtered by suction, and the residue was dried under reduced pressure at 60°C overnight. Then, 54.8 g of resin 1 was obtained. The obtained polymer corresponded to formula (2-1). The weight average molecular weight Mw measured by GPC in terms of polystyrene was 2,900. [ka]

[0081] (Synthesis of resin 2) In a three-neck flask, 30.0 g of TEP-DF (manufactured by Asahi Organic Chemicals Co., Ltd.), 16.43 g of 4,4-difluorobenzophenone (manufactured by Tokyo Chemical Industry Co., Ltd.), 14.47 g of potassium carbonate (manufactured by Wako Pure Chemical Industries, Ltd.), and 142.1 g of N-methylpyrrolidone (manufactured by Kanto Chemical Co., Ltd.) were placed. The mixture was then heated to 150°C and stirred for about 4 hours. After the reaction was completed, the mixture was diluted with 261.1 g of N-methylpyrrolidone, and potassium carbonate was removed by filtration. The obtained filtrate was neutralized by adding 1N-HCl, and then stirred for a while. This diluted solution was dropped into a methanol / water = 90 / 10 (vol / vol) solution to cause reprecipitation. The obtained precipitate was filtered by suction, and the filtrate was dried under reduced pressure at 60°C overnight. Then, 29.1 g of resin 2 was obtained. The obtained polymer corresponded to the formula (2-2). The weight average molecular weight Mw measured in terms of polystyrene by GPC was 2,900. [ka]

[0082] (Synthesis of resin 3) In a three-neck flask, 30.0 g of TEP-TPA (manufactured by Asahi Organic Chemicals Co., Ltd.), 13.81 g of 4,4-difluorobenzophenone (manufactured by Tokyo Chemical Industry Co., Ltd.), 12.16 g of potassium carbonate (manufactured by Wako Pure Chemical Industries, Ltd.), and 130.61 g of N-methylpyrrolidone (manufactured by Kanto Chemical Co., Ltd.) were placed. The mixture was then heated to 150°C and stirred for about 4 hours. After the reaction was completed, the mixture was diluted with 252.3 g of N-methylpyrrolidone, and potassium carbonate was removed by filtration. The filtrate obtained was neutralized by adding 1N-HCl, and then stirred for a while. This diluted solution was dropped into a methanol / water = 90 / 10 (vol / vol) solution to cause reprecipitation. The precipitate obtained was filtered by suction, and the residue was dried under reduced pressure at 60°C overnight. Then, 18.6 g of resin 3 was obtained. The obtained polymer corresponded to the formula (2-3). The weight average molecular weight Mw measured in terms of polystyrene by GPC was 3,400. [ka]

[0083] (Synthesis Example 1) Into a recovery flask were placed 5.00 g of resin 1, 3.54 g of allyl glycidyl ether (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.02 g of hydroquinone (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.58 g of ethyltriphenylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.), 9.17 g of N-methylpyrrolidone (manufactured by Kanto Chemical Co., Ltd.), and 21.4 g of propylene glycol monomethyl ether acetate. The mixture was then heated to 100° C. and stirred for about 24 hours. After the reaction was completed, the mixture was diluted with 5.96 g of N-methylpyrrolidone and dropped into a methanol / water = 90 / 10 (vol / vol) solution to cause reprecipitation. The precipitate obtained was filtered by suction, and the residue was dried under reduced pressure at 60 ° C overnight. Thus, 3.37 g of resin 2 was obtained. The obtained polymer corresponded to formula (1-4-1). The weight average molecular weight Mw measured by GPC in terms of polystyrene was 3,700.

[0084] (Synthesis Example 2) Into a recovery flask were placed 5.00 g of resin 1, 7.34 g of glycidyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.03 g of hydroquinone (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.96 g of ethyltriphenylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.), 9.33 g of N-methylpyrrolidone (manufactured by Kanto Chemical Co., Ltd.), and 21.8 g of propylene glycol monomethyl ether acetate. The mixture was then heated to 100° C. and stirred for approximately 18 hours. After the reaction was completed, the mixture was diluted with 22.2 g of N-methylpyrrolidone and dropped into a methanol / water = 90 / 10 (vol / vol) solution to cause reprecipitation. The obtained precipitate was filtered by suction, and the residue was dried under reduced pressure at 60 ° C overnight. Thus, 4.85 g of resin 3 was obtained. The obtained polymer corresponded to the formula (1-4-2). The weight average molecular weight Mw measured by GPC in terms of polystyrene was 3,900.

[0085] (Synthesis Example 3) Into a recovery flask were placed 5.00 g of resin 1, 5.00 g of allyl bromide (manufactured by Tokyo Chemical Industry Co., Ltd.), 3.97 g of potassium carbonate (manufactured by Wako Pure Chemical Industries, Ltd.), and 20.59 g of N-methylpyrrolidone (manufactured by Kanto Chemical Co., Ltd.), and the mixture was then heated to 100° C. and stirred for about 24 hours. After the reaction was completed, the mixture was diluted with 15.1 g of N-methylpyrrolidone, and potassium carbonate was removed by filtration. The filtrate was neutralized by adding 1N-HCl, and then stirred for a while. This diluted solution was dropped into a methanol / water = 90 / 10 (vol / vol) solution to cause reprecipitation. The precipitate was filtered by suction, and the residue was dried under reduced pressure at 60 ° C. overnight. Thus, 4.00 g of resin 4 was obtained. The obtained polymer corresponded to the formula (1-4-3). The weight average molecular weight Mw measured by GPC in terms of polystyrene was 3,100.

[0086] (Synthesis Example 4) In a recovery flask, add 10.00 g of resin 2, 12.68 g of glycidyl methacrylate (Tokyo Chemical Industry Co., Ltd.), 0.05 g of hydroquinone (Tokyo Chemical Industry Co., Ltd.), and ethyl trimethylsilane. 1.16 g of phenylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.), 17.07 g of N-methylpyrrolidone (manufactured by Kanto Chemical Co., Ltd.), and 39.84 g of propylene glycol monomethyl ether acetate were added, and the mixture was then heated to 100° C. and stirred for about 12 hours. After the reaction was completed, the reaction mixture was diluted with 40.0 g of N-methylpyrrolidone and added dropwise to a methanol solution to cause reprecipitation. The resulting precipitate was filtered by suction, and the residue was dried under reduced pressure at 60° C. overnight. Thus, 15.02 g of resin 5 was obtained. The obtained polymer corresponded to the formula (1-4-11). The weight average molecular weight Mw measured by GPC in terms of polystyrene was 7,400.

[0087] (Synthesis Example 5) Into a recovery flask were placed 10.00 g of resin 3, 11.24 g of glycidyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.04 g of hydroquinone (manufactured by Tokyo Chemical Industry Co., Ltd.), 1.47 g of ethyltriphenylphosphonium bromide (manufactured by Hokko Chemical Industry Co., Ltd.), 15.93 g of N-methylpyrrolidone (manufactured by Kanto Chemical Co., Ltd.), and 37.16 g of propylene glycol monomethyl ether acetate. The mixture was then heated to 100° C. and stirred for about 12 hours. After the reaction was completed, the mixture was diluted with 37.6 g of N-methylpyrrolidone and dropped into a methanol solution to cause reprecipitation. The precipitate obtained was filtered by suction, and the residue was dried under reduced pressure at 60°C overnight. Thus, 13.12 g of resin 6 was obtained. The obtained polymer corresponded to the formula (1-4-12). The weight average molecular weight Mw measured by GPC in terms of polystyrene was 5,200.

[0088] (Comparative Synthesis Example 1) The above resin 1 was prepared as the resin of Comparative Synthesis Example 1.

[0089] (Comparative Synthesis Example 2) 10.00 g of an epoxy group-containing benzene condensed ring compound (trade name: EPICLON HP-4700, epoxy value: 165 g / eq., manufactured by DIC Corporation), 4.37 g of acrylic acid, 0.56 g of ethyl triphenylphosphonium bromide, and 0.03 g of hydroquinone were added to 34.91 g of propylene glycol monomethyl ether, and the mixture was heated and stirred at 100° C. for 21 hours under a nitrogen atmosphere. 15 g of a cation exchange resin (product name: Dowex [registered trademark] 550A, manufactured by Muromachi Technos Co., Ltd.) and 15 g of an anion exchange resin (product name: Amberlite [registered trademark] 15JWET, manufactured by Organo Corporation) were added to the resulting solution, and the mixture was subjected to ion exchange treatment at room temperature for 4 hours. After separating the ion exchange resin, a compound solution was obtained. The resulting compound corresponds to the formula (2-2), and the weight average molecular weight Mw measured in terms of polystyrene by GPC was 1,400. [ka]

[0090] Example 1 The resin obtained in Synthesis Example 1 was dissolved in propylene glycol monomethyl ether acetate, A resin solution (solid content 20.60% by mass) was obtained through ion exchange. 0.05 g of propylene glycol monomethyl ether acetate containing 1% by mass of surfactant (manufactured by DIC Corporation, trade name Megafac R-40) and 2.60 g of propylene glycol monomethyl ether acetate were added to 2.50 g of this resin solution, and the mixture was filtered through a polytetrafluoroethylene microfilter having an aperture of 0.1 μm to prepare a solution of a resist underlayer film forming composition.

[0091] Example 2 The resin obtained in Synthesis Example 2 was dissolved in propylene glycol monomethyl ether acetate, and then ion-exchanged to obtain a resin solution (solid content: 18.67% by mass). 0.05 g of propylene glycol monomethyl ether acetate containing 1% by mass of surfactant (manufactured by DIC Corporation, trade name Megafac R-40) and 2.38 g of propylene glycol monomethyl ether acetate were added to 2.80 g of this resin solution, and the mixture was filtered through a polytetrafluoroethylene microfilter having an aperture of 0.1 μm to prepare a solution of a resist underlayer film-forming composition.

[0092] Example 3 The resin obtained in Synthesis Example 3 was dissolved in propylene glycol monomethyl ether acetate, and then ion-exchanged to obtain a resin solution (solid content: 20.00% by mass). 0.04 g of propylene glycol monomethyl ether acetate containing 1% by mass of surfactant (manufactured by DIC Corporation, trade name Megafac R-40) and 1.97 g of propylene glycol monomethyl ether acetate were added to 2.00 g of this resin solution, and the mixture was filtered through a polytetrafluoroethylene microfilter having an aperture of 0.1 μm to prepare a solution of a resist underlayer film-forming composition.

[0093] Example 4 The resin obtained in Synthesis Example 4 was dissolved in propylene glycol monomethyl ether acetate, and then ion-exchanged to obtain a resin solution (solid content: 13.65% by mass). 0.16 g of propylene glycol monomethyl ether acetate containing 1% by mass of surfactant (manufactured by DIC Corporation, trade name Megafac R-40) and 3.99 g of propylene glycol monomethyl ether acetate were added to 5.85 g of this resin solution, and the mixture was filtered through a polytetrafluoroethylene microfilter having an aperture of 0.1 μm to prepare a solution of a resist underlayer film-forming composition.

[0094] Example 5 The resin obtained in Synthesis Example 5 was dissolved in propylene glycol monomethyl ether acetate, and then ion-exchanged to obtain a resin solution (solid content: 18.53% by mass). 0.16 g of propylene glycol monomethyl ether acetate containing 1% by mass of surfactant (manufactured by DIC Corporation, trade name Megafac R-40) and 5.53 g of propylene glycol monomethyl ether acetate were added to 4.31 g of this resin solution, and the mixture was filtered through a polytetrafluoroethylene microfilter having an aperture of 0.1 μm to prepare a solution of a resist underlayer film-forming composition.

[0095] Comparative Example 1 The resin obtained in Comparative Synthesis Example 1 was dissolved in propylene glycol monomethyl ether acetate, and then ion-exchanged to obtain a resin solution (solid content: 16.94% by mass). 0.06 g of propylene glycol monomethyl ether acetate containing 1% by mass of surfactant (manufactured by DIC Corporation, trade name Megafac R-40) and 2.04 g of propylene glycol monomethyl ether acetate were added to 3.00 g of this resin solution, and the mixture was filtered through a polytetrafluoroethylene microfilter having an aperture of 0.1 μm to prepare a solution of a resist underlayer film-forming composition.

[0096] Comparative Example 2 4.19 g of the resin solution (solid content: 25.02% by mass) obtained in Comparative Synthesis Example 2 was mixed with 0.001 g of a surfactant (manufactured by DIC Corporation, trade name: Megafac R-40) and propylene glycol monohydrate. To the mixture, 6.62 g of propylene glycol monomethyl ether and 4.19 g of propylene glycol monomethyl ether acetate were added to prepare a solution of a resist underlayer film forming composition.

[0097] (Photocuring test) The resist underlayer film forming compositions prepared in Examples 1 to 5 and Comparative Examples 1 and 2 were each applied (spin coated) onto a silicon wafer using a spinner. The wafer was heated on a hot plate at 215°C for 1 minute to form a coating (resist underlayer film) with a thickness of about 200 nm. This resist underlayer film coating was then exposed to 500 mJ / cm 2 UV irradiation using a UV irradiation unit (wavelength 172 nm) manufactured by Ushio Inc. 2 The coating film was irradiated with ultraviolet light for 10 minutes, and the solvent peelability was confirmed by light irradiation (UV irradiation). The coating film after UV irradiation was immersed in a mixed solvent of propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate (7:3) for 1 minute, spin-dried, and baked at 100°C for 1 minute, and the film thickness was measured. The film shrinkage rate before and after light irradiation was also calculated (results in Table 1). [Table 1]

[0098] (Optical constant measurement) The solutions of the resist underlayer film forming compositions prepared in Examples 1 to 5 and Comparative Examples 1 and 2 were applied onto a silicon wafer using a spin coater. The resist underlayer film was baked on a hot plate at 215°C for 1 minute to form a resist underlayer film (film thickness 0.05 μm). The refractive index (n value) and optical absorption coefficient (k value, also called attenuation coefficient) of these resist underlayer films at wavelengths of 193 nm and 248 nm were measured using a spectroscopic ellipsometer (results in Table 2). In addition, the resist underlayer film coating film was irradiated with ultraviolet light at 500 mJ / cm2 using an ultraviolet light irradiation device using a UV irradiation unit (wavelength 172 nm) manufactured by Ushio Inc., and the refractive index and optical absorption coefficient at wavelengths of 193 nm and 248 nm after light irradiation (ultraviolet light irradiation) were measured (results in Table 3). [Table 2] [Table 3]

[0099] (Measurement of dry etching rate) The etcher and etching gas used in the measurement of the dry etching rate were as follows: RIE-10NR (Samco): CF 4 The solutions of the resist underlayer film forming compositions prepared in Examples 1 to 5 and Comparative Examples 1 and 2 were each applied onto a silicon wafer using a spin coater. The wafer was baked on a hot plate at 215° C. for 1 minute to form a resist underlayer film (film thickness: 0.20 μm). CF 4 The dry etching rate was measured using a gas, and the dry etching rate of the resist underlayer film was compared with that of Examples 1 to 3 and Comparative Examples 1 and 2. In addition, this resist underlayer film coating film was irradiated with 500 mJ / cm 2 of ultraviolet light using an ultraviolet irradiation device using a UV irradiation unit (wavelength 172 nm) manufactured by Ushio Inc. 2 The dry etching rate of the resist underlayer film was compared with that of Examples 1 to 3 and Comparative Examples 1 and 2. The results are shown in Table 4. The dry etching rate ratio is the dry etching rate ratio of (resist underlayer film) / (KrF photoresist) (results in Table 4). [Table 4]

[0100] (Heat resistance test of resist underlayer film) The solutions of the resist underlayer film-forming compositions prepared in Examples 1 to 5 and Comparative Examples 1 and 2 were each applied onto a silicon wafer using a spin coater and baked on a hot plate at 215°C for 60 seconds to form a resist underlayer film (film thickness 0.20 µm). In addition, this resist underlayer film coating was irradiated with 500 mJ / cm2 of UV light using an ultraviolet irradiator using a UV irradiation unit (wavelength 172 nm) manufactured by Ushio Inc. 2The film was heated from room temperature (about 20°C) at a rate of 10°C per minute and subjected to thermogravimetric analysis in air to track the weight loss over time. The results are shown in Table 5. [Table 5]

[0101] (Coating test for stepped substrate) To evaluate the step coverage, a 200 nm thick SiO 2 A comparison was made between the coating thickness of a dense pattern area (DENSE) with a trench width of 50 nm and a pitch of 100 nm and an open area (OPEN) with no pattern formed on the substrate. The resist underlayer film forming compositions of Examples 1 to 3 and Comparative Examples 1 and 2 were applied onto the substrate, and then baked at 215° C. for 60 seconds to form a resist underlayer film. The resist underlayer film forming composition was prepared so that the film thickness on a solid substrate was 150 nm. The step coverage of this substrate was observed using a scanning electron microscope (S-4800) manufactured by Hitachi High-Technologies Corporation, and the planarization property was evaluated by measuring the film thickness difference (the coating step between the dense area and the open area, which is called the bias) between the dense area (pattern part) and the open area (part without pattern) of the step substrate. Here, planarization means that there is a small difference in thickness (iso-dense bias) between the area where a pattern exists (dense area (patterned area)) and the area where a pattern does not exist (open area (no pattern)) (results in Table 6). [Table 6] [Industrial Applicability]

[0102] The photocurable coating composition for coating uneven substrates of the present invention provides a coating film having planarizing properties that has high filling ability into patterns and can be formed into a coating film by photocuring without causing degassing or thermal shrinkage, and that is capable of forming a coating film with high heat resistance on a substrate after irradiation with light.

Claims

1. Formula (1): 【Chemistry 1】 [In formula (1), A 1 is expressed by the formula (1-1): 【Chemistry 2】 (In the formula (1-1), q is an integer of 2 to 6, and when q is 2, T 2 represents a single bond, a hydrocarbon group having 1 to 2 carbon atoms, or an arylalkyl group having 7 to 28 carbon atoms; when q is 3 to 6, T 2 is a C3-C6 hydrocarbon group which may have a hydroxyl group, or m is an integer of 1 to 7, and p is an integer of 0 or 1. two hydroxyl groups among the m×q hydroxyl groups in the polynuclear phenol have reacted to form bonds via O atoms; The polyphenol may be a polyphenol having the remaining hydroxyl groups and / or a hydroxyl group selected from the m×q hydroxyl groups. 2 reacts with the hydroxyl group to form a bond with B 1 via the O atom, However, B 1 The total number of bonds bonded to is n1, A 2 and A 3 each independently represents a group derived from a benzene ring or a naphthalene ring, B 1 is expressed by the formula (2): 【Chemistry 3】 (In formula (2), R 1 represents an alkylene group having 1 to 10 carbon atoms (the alkylene group may be optionally substituted with one or more hydroxyl groups), an oxygen atom, a carbonyl group, -C(O)-O-, or a group consisting of a combination thereof; R 2 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and the dotted line represents A 1 ) and X is a carbonyl group, a sulfonyl group, -CR 2 2 - group, or -C(CF 3 ) 2 -group, and n1 is 1≦n1≦4.

2. A 1 2. The photocurable composition for covering stepped substrates according to claim 1, wherein is a group derived from tri(hydroxyphenyl)methane, a group derived from tetrakis(hydroxyphenyl)ethane, or a group derived from tetrakis(hydroxyphenyl)-p-xylene.

3. 3. The photocurable composition for covering uneven substrates according to claim 1, wherein X is a carbonyl group.

4. 2. The photocurable composition for covering uneven substrates according to claim 1, which is a polymer containing a unit structure of formula (1) in which n1 is 1 or 2, and n2 and n3 are 0.

5. The polymer further comprises a unit structure of formula (3): 【Chemistry 4】 (In formula (3), A 4 and A 5 each represents an aromatic ring having 6 to 48 carbon atoms which may contain a heteroatom, or a hydrocarbon group containing an aromatic ring having 6 to 48 carbon atoms which may contain a heteroatom; B 4 and B 5 is B in the above formula (2) 1 , B 2 and B 3 wherein n4 is an integer of 1≦n4≦4, n5 is an integer of 0≦n5≦4, and n4+n5=an integer of 1 to 8. The photocurable composition for covering uneven substrates according to any one of claims 1 to 4, comprising a polymer containing

6. 6. The photocurable stepped substrate coating composition according to claim 1, wherein the polymer further comprises a unit structure of formula (1') in which n1=0 in formula (1) in addition to the unit structures of formula (1) and formula (3).

7. 7. The photocurable composition for covering an uneven substrate according to claim 1, which is a resist underlayer film forming composition used in a lithography process for producing a semiconductor device.

8. A method for producing a coated substrate, comprising the steps of: (i) applying the photocurable uneven substrate coating composition according to claim 1 to a substrate having an uneven surface; and (ii) exposing the substrate to light.

9. 9. The method for producing a coated substrate according to claim 8, further comprising the step (ia) of heating at a temperature of 70 to 400° C. for 10 seconds to 5 minutes after applying the photocurable uneven substrate coating composition of step (i).

10. 10. The method for producing a coated substrate according to claim 8 or 9, wherein the exposure wavelength in step (ii) is from 150 nm to 248 nm.

11. The exposure dose in step (ii) is 10 mJ / cm 2 ~3000mJ / cm 2 The method for producing a coated substrate according to any one of claims 8 to 10, wherein

12. 12. The method for producing a coated substrate according to any one of claims 8 to 11, wherein the substrate has open areas (non-patterned areas) and DENCE (dense) and ISO (coarse) patterned areas, and the aspect ratio of the patterns is between 0.1 and 10.

13. 13. The method for producing a coated substrate according to claim 12, wherein a bias (a coating step) between the open area and the pattern area is 1 to 50 nm.

14. A semiconductor manufacturing method comprising the steps of forming an underlayer film on a substrate having steps using the uneven substrate coating composition according to any one of claims 1 to 7, forming a resist film thereon, forming a resist pattern by irradiating light or an electron beam and developing, etching the underlayer film using the resist pattern, and processing a semiconductor substrate using the patterned underlayer film. A method for manufacturing a semiconductor device.

15. 8. A method for manufacturing a semiconductor device, comprising the steps of: forming an underlayer film on a substrate having steps from the photocurable uneven substrate coating composition according to claim 1; forming a hard mask thereon; further forming a resist film thereon; forming a resist pattern by exposure to light or an electron beam and development; etching the hard mask with the resist pattern; etching the underlayer film with the patterned hard mask; and processing a semiconductor substrate with the patterned underlayer film.

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