Method for manufacturing semiconductor substrate and composition for forming resist underlayer film

Abstract

The invention provides a method for manufacturing a semiconductor substrate and a composition for forming a resist underlayer film, wherein the method can form the resist underlayer film with excellent pattern rectangularity. A method for manufacturing a semiconductor substrate, comprising: a step for directly or indirectly applying a resist underlayer film-forming composition on a substrate; a step for directly or indirectly applying a composition for forming a resist film on the resist underlayer film formed by the step for applying the composition for forming a resist underlayer film; a step for exposing the resist film formed by the step for applying the composition for forming the resist film to light; and a step for developing at least the exposed resist film. The resist underlayer film-forming composition contains: a compound; and a solvent, the compound has-ORA, RA is any one of a hydrogen atom, a monovalent heteroatom-containing group having 1-10 carbon atoms, or a monovalent organic group having 1-10 carbon atoms (excluding a monovalent heteroatom-containing group having 1-10 carbon atoms), and in the structure constituting the RA, x is the ratio of the hydrogen atom, y is the ratio of the monovalent heteroatom-containing group having 1-10 carbon atoms, x is the ratio of the hydrogen atom, y is the ratio of the monovalent heteroatom-containing group having 1-10 carbon atoms, x is the ratio of the hydrogen atom, y is the ratio of the monovalent heteroatom-containing group having 1-10 carbon atoms, and y is the ratio of the monovalent heteroatom-containing group having 1-10 carbon atoms. When the ratio of a monovalent organic group having 1-10 carbon atoms is defined as x, the ratio of a monovalent organic group having 1-10 carbon atoms is defined as z, the entire compound satisfies the relationships x + y + z = 100, 20 < = x < = 95, and 5 < = y < = 80, and the compound is a polymer having a repeating unit represented by formula (1), an aromatic ring-containing compound having a molecular weight of 750-3000 and having-ORA, or a combination of these. (In formula (1), Ar1 is a divalent group having an aromatic ring having 5-40 ring members, R0 is a hydrogen atom or a monovalent organic group having 1-40 carbon atoms, R1 is a monovalent organic group having 1-40 carbon atoms, and at least one selected from the group consisting of Ar1, R0, and R1 has-ORA)

Description

TECHNICAL FIELD

[0001] The present application relates to a method for manufacturing a semiconductor substrate and a method for manufacturing a resist underlayer film-forming composition. BACKGROUND

[0002] In the production of semiconductor elements, for example, a multilayer resist process has been used in which a resist film is layered on a substrate with a resist underlayer film such as an organic underlayer film or a silicon-containing film interposed therebetween, and the resist film is subjected to exposure and development, thereby forming a resist pattern. In this process, the resist underlayer film is etched with the resist pattern as a mask, and the substrate is further etched with the obtained resist underlayer film pattern as a mask, whereby a desired pattern can be formed on the semiconductor substrate.

[0003] In recent years, further advancement of high integration of semiconductor elements has been promoted, and there is a tendency toward shortening of the wavelength of exposure light from KrF excimer laser (248 nm), ArF excimer laser (wavelength 193 nm) to Extreme Ultraviolet (13.5 nm, hereinafter also referred to as "EUV"). In this regard, various studies have been made on a resist underlayer film-forming composition for EUV exposure (see International Publication No. 2021 / 157551).

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: International Publication No. 2021 / 157551 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] A resist underlayer film-forming composition is required to suppress the pattern sag at the bottom of a resist film to ensure the pattern rectangularity of a resist pattern.

[0009] The present application has been made based on the above-described fact, and aims to provide a method for manufacturing a semiconductor substrate and a resist underlayer film-forming composition, which can form a resist underlayer film having excellent pattern rectangularity.

[0010] MEANS OF SOLVING THE PROBLEM

[0011] The present application relates to a method for manufacturing a semiconductor substrate, comprising:

[0012] a step of applying a resist underlayer film-forming composition directly or indirectly on a substrate;

[0013] a step of applying a resist film-forming composition directly or indirectly on a resist underlayer film formed in the resist underlayer film-forming composition application step;

[0014] a step of exposing a resist film formed in the resist film-forming composition application step; and

[0015] at least a step of developing the exposed resist film,

[0016] the resist underlayer film-forming composition contains:

[0017] a compound (hereinafter, also referred to as "[A] compound"); and

[0018] a solvent (hereinafter, also referred to as "[B] solvent"),

[0019] the compound has -OR A , R A is any one of a hydrogen atom, a monovalent heteroatom-containing group having a carbon number of 1 to 10, or a monovalent organic group having a carbon number of 1 to 10 (excluding the monovalent heteroatom-containing group having a carbon number of 1 to 10), and in a structure constituting the R A , a proportion of the hydrogen atom is x, a proportion of the monovalent heteroatom-containing group having a carbon number of 1 to 10 is y, and a proportion of the monovalent organic group having a carbon number of 1 to 10 is z, the compound as a whole satisfies the relationships of x + y + z = 100 and 20 ≦ x ≦ 95, 5 ≦ y ≦ 80,

[0020] the compound is a polymer having a repeating unit represented by the following formula (1) (hereinafter, also referred to as "[A1] polymer"), a compound having an aromatic ring having -OR A with a molecular weight of 750 or more and 3000 or less (hereinafter, also referred to as "[A2] compound having an aromatic ring"), or a combination of these.

[0021] [Chemical Formula 1]

[0022]

[0023] (In formula (1), Ar 1 is a divalent group having an aromatic ring having a ring member number of 5 to 40. R 0 is a hydrogen atom or a monovalent organic group having a carbon number of 1 to 40. R 1 is a monovalent organic group having a carbon number of 1 to 40. At least one selected from the group consisting of Ar 1 , R 0 , and R 1 has -OR A )

[0024] The present application relates to a composition for forming a resist underlayer film, comprising:

[0025] a compound; and

[0026] a solvent,

[0027] the compound has -OR A , R A is any one of a hydrogen atom, a monovalent heteroatom-containing group having a carbon number of 1 to 10, or a monovalent organic group having a carbon number of 1 to 10 (except for the monovalent heteroatom-containing group having a carbon number of 1 to 10), in a structure constituting the R A , in a case where a proportion of the hydrogen atom is set as x, a proportion of the monovalent heteroatom-containing group having a carbon number of 1 to 10 is set as y, and a proportion of the monovalent organic group having a carbon number of 1 to 10 is set as z, the following relation is satisfied in the compound as a whole: x + y + z = 100 and 20 ≦ x ≦ 95, 5 ≦ y ≦ 80,

[0028] the compound is a polymer having a repeating unit represented by the following formula (1), a compound having an aromatic ring having a molecular weight of 750 or more and 3000 or less and -OR A , or a combination of these.

[0029] [Chemical 2]

[0030]

[0031] (in formula (1), Ar 1 is a divalent group having an aromatic ring having a ring member number of 5 to 40. R 0 is a hydrogen atom or a monovalent organic group having a carbon number of 1 to 40. R 1 is a monovalent organic group having a carbon number of 1 to 40. At least one selected from the group consisting of Ar 1 , R 0 , and R 1 has -OR A )

[0032] Effects of the Invention

[0033] According to the semiconductor substrate manufacturing method, a resist underlayer film having excellent pattern rectangularity is formed, and thus a semiconductor substrate that is well patterned can be obtained. According to the composition for forming a resist underlayer film, a resist underlayer film having excellent pattern rectangularity can be formed. Furthermore, according to the semiconductor substrate manufacturing method, a resist underlayer film having excellent embedding property of a pattern that can be sufficiently embedded into a substrate, and excellent flatness of a film after embedding can be formed. According to the composition for forming a resist underlayer film, a resist underlayer film having excellent embedding property and flatness can be formed. Thus, these can be preferably used in manufacturing of a semiconductor element, and the like, which is expected to be further miniaturized in the future. Attached Figure Description

[0034] [ Figure 1 This is a schematic cross-sectional view of a silicon substrate with a resist underlayer used to illustrate a method for evaluating flatness. Detailed Implementation

[0035] Hereinafter, methods for manufacturing semiconductor substrates and compositions for forming resist underlayer films according to various embodiments of the present invention will be described in detail. Furthermore, combinations of preferred embodiments are also preferred.

[0036] Manufacturing Methods of Semiconductor Substrates

[0037] The method for manufacturing the semiconductor substrate includes: a step of directly or indirectly coating a resist underlayer film forming composition onto a substrate (hereinafter also referred to as "coating step (I)"); a step of directly or indirectly coating a resist film forming composition onto a resist underlayer film formed by the resist underlayer film forming step (hereinafter also referred to as "coating step (II)"); a step of exposing the resist film formed by the resist film forming step to extreme ultraviolet light (hereinafter also referred to as "exposure step"); and a step of developing at least the exposed resist film (hereinafter also referred to as "development step").

[0038] The semiconductor substrate manufacturing method may, as needed, include a process of forming a silicon-containing film directly or indirectly on the substrate (hereinafter also referred to as the "silicon-containing film forming process") before the coating process (I).

[0039] First, the composition for forming the resist underlayer film used in the method for manufacturing the semiconductor substrate will be described. Then, each step, including the silicon-containing film formation step as an optional step, will be described.

[0040] Compositions for forming resist underlayer films

[0041] The resist underlayer film forming composition (hereinafter also referred to as the "composition") contains compound [A] and solvent [B]. The composition may also contain any components without impairing the effects of the present invention.

[0042] The components contained in the composition are described below.

[0043] <[A]compound>

[0044] [A] Compounds have -OR AAdditionally, [A] compounds are [A1] polymers, [A2] aromatic ring-containing compounds (excluding compounds equivalent to [A1] polymers), or combinations thereof. Therefore, [A1] polymers may have -OR A [A2] Compounds containing an aromatic ring may have -OR A Either [A1] polymer or [A2] aromatic ring-containing compound may have -OR A [A1] Polymers and [A2] Aromatic ring-containing compounds may be used alone or in combination of two or more. -OR A Details are provided in the sections on [A1] polymers and [A2] compounds containing aromatic rings.

[0045] ([A1] polymer)

[0046] [A1] polymers, which are [A] compounds, are polymers having repeating units represented by the following formula (1). [A1] polymers may have two or more repeating units represented by the following formula (1).

[0047] [Chemistry 3]

[0048]

[0049] (In formula (1), Ar) 1 It is a divalent group having an aromatic ring with 5 to 40 ring elements. R 0 It is a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms. R 1 It is a monovalent organogroup with 1 to 40 carbon atoms. (Selected from Ar...) 1 R 0 and R 1 At least one of the groups formed has -OR A )

[0050] In the above formula (1), Ar is used as 1 The aromatic rings in the rings are aromatic rings with 5 to 40 ring elements, such as: aromatic hydrocarbon rings with the following ring numbers: benzene ring, naphthalene ring, anthracene ring, ferroyl ring, phenanthrene ring, pyrene ring, fluorene ring, perylene ring, cardamom ring, etc.; furan ring, pyrrole ring, thiophene ring, phosphole ring, pyrazole ring, oxazole ring, isoxazole ring, thiazole ring, pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, triazine ring, etc.; or combinations thereof. The aromatic ring is preferably at least one aromatic hydrocarbon ring selected from the group consisting of benzene ring, naphthalene ring, anthracene ring, ferroyl ring, phenanthrene ring, pyrene ring, fluorene ring, and perylene ring.

[0051] In this specification, the term "ring element number" refers to the number of atoms that make up the ring. For example, the biphenyl ring has 12 ring elements, the naphthalene ring has 10 ring elements, and the fluorene ring has 13 ring elements. The term "polycyclic aromatic ring" refers to a polycyclic aromatic hydrocarbon composed of multiple aromatic rings sharing a common edge (a bond between two adjacent atoms).

[0052] In the above formula (1), Ar is used as 1 The divalent groups representing aromatic rings with 5 to 40 ring elements can preferably be listed from the Ar group. 1 The aromatic rings may consist of 5 to 40 ring elements, or a combination of the aromatic rings and a chain structure with two hydrogen atoms removed to form a base. In the case of combined aromatic rings, the aromatic rings may be bonded to each other not only by condensation ring structures but also by single bonds.

[0053] The chain structure is preferably formed by removing two hydrogen atoms from a chain hydrocarbon having 1 to 20 carbon atoms. Examples of chain hydrocarbons having 1 to 20 carbon atoms include alkanes such as methane, ethane, propane, butane, hexane, and octane. These can be either straight-chain or branched. Among them, straight-chain or branched alkanes having 1 to 8 carbon atoms are preferred.

[0054] In the above equation (1), R is used as 0 and R 1 Examples of monovalent organic groups with 1 to 40 carbon atoms include: monovalent hydrocarbon groups with 1 to 20 carbon atoms; groups having a divalent heteroatom-containing linker between carbon atoms or at the end of the carbon chain of the hydrocarbon group; groups formed by substituting some or all of the hydrogen atoms of the hydrocarbon group with a monovalent heteroatom-containing substituent; or combinations thereof.

[0055] Examples of monovalent hydrocarbon groups with 1 to 20 carbon atoms include: monovalent chain hydrocarbon groups with 1 to 20 carbon atoms, monovalent alicyclic hydrocarbon groups with 3 to 20 carbon atoms, monovalent aromatic hydrocarbon groups with 6 to 20 carbon atoms, or combinations thereof.

[0056] Examples of monovalent chain hydrocarbon groups with 1 to 20 carbon atoms include: alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, and tert-butyl; alkenyl groups such as vinyl, propenyl, and butenyl; and alkynyl groups such as ethynyl, propynyl, and butynyl.

[0057] Examples of monovalent alicyclic hydrocarbon groups with 3 to 20 carbon atoms include: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and other cycloalkyl groups; cyclopropenyl, cyclopentenyl, cyclohexenyl, and other cycloalkenyl groups; bridged cyclic saturated hydrocarbon groups such as norbornyl, adamantyl, and tricyclodecyl; and bridged cyclic unsaturated hydrocarbon groups such as norbornyl and tricyclodecenyl.

[0058] Examples of monovalent aromatic hydrocarbon groups with 6 to 20 carbon atoms include: phenyl, tolyl, naphthyl, anthracenel, pyrene, etc.

[0059] Examples of heteroatoms that can be used as linking groups or substituents for monovalent heteroatoms include: oxygen, nitrogen, sulfur, phosphorus, silicon, and halogen atoms. Examples of halogen atoms include: fluorine, chlorine, bromine, and iodine atoms.

[0060] Examples of divalent heteroatom-containing linking groups include: -CO-, -CS-, -NH-, -O-, -S-, -SO-, -SO2-, or groups formed by combining these.

[0061] Examples of monovalent substituents containing heteroatoms include: hydroxyl, hydrogen sulfide, cyano, nitro, and halogen atoms.

[0062] The R 0 Hydrogen atoms are preferred.

[0063] The R 1 Preferably, it has an aromatic ring having 5 to 40 ring elements. As the R... 1 The aromatic rings with 5 to 40 ring elements in the Ar rings can preferably be the Ar rings. 1 The aromatic rings in the rings range from 5 to 40.

[0064] In the above equation (1), Ar is selected. 1 R 0 and R 1 At least one of the groups formed has -OR A Ar is preferred. 1 and R 1 At least one of them has -OR A -OR A With constituting the choice of Ar 1 R 0 and R 1 At least one carbon atom bond in the group formed. R A It is any one of a hydrogen atom, a monovalent heteroatom-containing group having 1 to 10 carbon atoms, or a monovalent organic group having 1 to 10 carbon atoms (excluding the monovalent heteroatom-containing group having 1 to 10 carbon atoms) (hereinafter also referred to as "organogroup (A)"). A In the structure, with the proportion of hydrogen atoms set as x, the proportion of monovalent heteroatom-containing groups with carbon numbers of 1 to 10 set as y, and the proportion of monovalent organic groups with carbon numbers of 1 to 10 set as z, the compound as a whole satisfies the relationship x + y + z = 100 and 20 ≦ x ≦ 95 and 5 ≦ y ≦ 80.

[0065] As R AThe monovalent heteroatom-containing groups representing carbon numbers from 1 to 10 can preferably be represented by the R group. 0 and R 1 The group representing a monovalent organic group with 1 to 40 carbon atoms, corresponding to carbon number 1 to 10, and having a linking group containing a divalent heteroatom or a substituent containing a monovalent heteroatom.

[0066] The number of carbon atoms in the heteroatom-containing base is preferably 1 to 8, more preferably 1 to 6, and even more preferably 1 to 4.

[0067] The heteroatom-containing group is preferably at least one selected from the group consisting of -O-, -CO-, -S-, -SO2-, -NR'- (R' is a monovalent organic group), -NO2, and -CN. More preferably, the heteroatom-containing group has at least one oxygen atom.

[0068] Examples of heteroatom-containing bases include structures represented by formulas (α-1) to (α-12), (β-1) to (β-8), and (γ-1) to (γ-8). Furthermore, in the formulas... It forms a bond with an oxygen atom.

[0069] [Chemistry 4]

[0070]

[0071] [Chemistry 5]

[0072]

[0073] [Chemistry 6]

[0074]

[0075] As R A The organic group (A) represented may preferably be the R. 0 and R 1 The monovalent organic groups representing carbon numbers from 1 to 40 correspond to carbon numbers from 1 to 10. Among them, R... A The organic group (A) represented is preferably a hydrocarbon group with 1 to 10 carbon atoms, more preferably a chain hydrocarbon group with 1 to 8 carbon atoms, and even more preferably an unsaturated chain hydrocarbon group with 2 to 6 carbon atoms.

[0076] constituting the R A In the structure, the proportion x of hydrogen atoms satisfies the relationship 20 ≤ x ≤ 95. The lower limit of the proportion x is preferably 30, more preferably 40, further preferably 50, and particularly preferably 60. The upper limit of the proportion x is preferably 90, more preferably 85, further preferably 80, and particularly preferably 75.

[0077] constituting the RA In the structure, the proportion y of monovalent heteroatom-containing groups having 1 to 10 carbon atoms satisfies the relationship 5 ≤ y ≤ 80. The lower limit of the proportion y is preferably 10, more preferably 15, further preferably 20, and particularly preferably 25. The upper limit of the proportion y is preferably 80, more preferably 70, further preferably 60, and particularly preferably 50.

[0078] constituting the R A In the structure, the proportion z of the organic group (A) satisfies 0 ≤ z ≤ 50. In the [A] compound, the organic group (A) acts as R... A In this case, the lower limit of the ratio z is preferably 1, more preferably 3, and even more preferably 5. The upper limit of the ratio y is preferably 40, more preferably 35, and even more preferably 30.

[0079] As a repeating unit represented by the above formula (1), for example, the repeating units represented by the following formulas (1-1) to (1-22) can be listed.

[0080] [Chemistry 7]

[0081]

[0082] [Chemistry 8]

[0083]

[0084] [Chemistry 9]

[0085]

[0086] In the formula, R A As described above.

[0087] The lower limit for the weight-average molecular weight of the [A1] polymer is preferably 1000, more preferably 1500, and even more preferably 2000. The upper limit for the molecular weight is preferably 10000, more preferably 8000, and even more preferably 6000. Furthermore, the method for determining the weight-average molecular weight is as described in the examples.

[0088] ([A1] Methods for manufacturing polymers)

[0089] [A1] Polymers, typically, are first provided by Ar as the polymer of formula (1). 1 Aromatic ring compounds having phenolic hydroxyl precursors, and R as providing the formula (1) 0 and R 1 The precursor polymer is prepared by acid addition condensation of an aldehyde derivative of the precursor. The aldehyde derivative may have phenolic hydroxyl groups. There are no particular limitations on the acid catalyst; known inorganic and organic acids can be used.

[0090] Next, the phenolic hydroxyl groups are modified with a modifying agent to introduce -OR into the [A1] polymer. A By introducing a monovalent heteroatom-containing group with 1 to 10 carbon atoms as R A In the specific case, the phenolic hydroxyl group can be used to modify the R... A The corresponding halides or anhydrides, nucleophilic reactions of acid halides, or reactions via phenolic hydroxyl groups as the modifier with R A The addition reaction of corresponding compounds containing carbon-carbon double bonds is used to produce compounds with -OR A The [A1] polymer. Furthermore, the modification rate of the modifier on the phenolic hydroxyl groups can be controlled by adjusting the number of moles of the modifier relative to the number of moles of the phenolic hydroxyl groups.

[0091] With the R A The corresponding halides can be listed, for example, in equations (α-1) to (α-12). Compounds in which halogen atoms are partially bonded, etc. With the aforementioned R... A The corresponding acid anhydrides or acid halides can be listed, for example, in formulas (β-1) to (β-8). Compounds in which acyloxy or halogen atoms are partially bonded, etc. And the R A Corresponding compounds containing carbon-carbon double bonds can be listed, for example, those corresponding to formulas (γ-1) to (γ-8). Compounds containing carbon-carbon double bonds between the α-carbon and β-carbon positions, etc.

[0092] The nucleophilic reaction can be carried out under alkaline conditions or in the presence of a base. The addition reaction can be carried out under an acid catalyst. After the reaction, the [A1] polymer can be obtained through separation, purification, drying, etc. The [B] solvent, described later, is preferably used as the reaction solvent.

[0093] ([A2] Compounds containing aromatic rings)

[0094] [A2] Compounds containing an aromatic ring only need to have -OR A Compounds with a molecular weight of 750 or more and 3000 or less are not particularly limited (except for compounds equivalent to [A1] polymers). The lower limit for the molecular weight of [A2] aromatic ring-containing compounds is preferably 750, more preferably 950, and even more preferably 1050. The upper limit for the molecular weight is preferably 3000, more preferably 2500, and even more preferably 2000.

[0095] [A2] The aromatic ring-containing compound is preferably the compound represented by the following formula (3).

[0096] [Chemistry 10]

[0097]

[0098] (In the aforementioned formula (3),

[0099] W is a q-valent group containing 5 to 60 substituted or unsubstituted aromatic rings.

[0100] R a It is a monovalent group containing aromatic rings with 5 to 40 ring elements.

[0101] q is an integer from 1 to 10. When q is greater than 2, multiple R... a They are the same or different.

[0102] W and one or more R a At least one of them has -OR A )

[0103] In the above formula (3), preferably one or more R a With -OR A More preferably, multiple R a At least one of them has -OR A Therefore, multiple R are preferred. a All have -OR A .

[0104] As the aromatic ring with a ring number of 5 to 60 in W, it is preferable to use Ar from formula (1). 1 Aromatic rings with 5 to 40 ring elements are extended to 60 ring elements to form aromatic rings. As a q-valent group represented by W that contains substituted or unsubstituted aromatic rings with 5 to 60 ring elements, examples can be listed of groups formed by removing q hydrogen atoms from said aromatic rings with 5 to 60 ring elements.

[0105] Examples of substituents that can be used when W has substituents include: monovalent chain hydrocarbons with 1 to 10 carbon atoms, halogen atoms such as fluorine, chlorine, bromine, and iodine, alkoxy groups such as methoxy, ethoxy, and propoxy, aryloxy groups such as phenoxy and naphthoxy, alkoxycarbonyl groups such as methoxycarbonyl and ethoxycarbonyl, alkoxycarbonyl groups such as methoxycarbonyloxy and ethoxycarbonyloxy, acyl groups such as formyl, acetyl, propionyl, and butyryl, cyano, nitro, and hydroxyl groups.

[0106] The aromatic ring in W is preferably at least one aromatic hydrocarbon ring selected from the group consisting of benzene ring, naphthalene ring, anthracene ring, fenestration ring, pyrene ring, fluorene ring, perylene ring and cardamom ring.

[0107] The W has -OR A In the case of W, preferably at least one hydrogen atom of the aromatic ring is -ORA replace.

[0108] As the R a The aromatic rings with 5 to 40 ring elements in the formula (1) are preferably Ar rings. 1 The aromatic rings in the R group consist of 5 to 40 ring elements. a The monovalent groups representing aromatic rings with 5 to 40 ring elements can be exemplified by groups formed by removing one hydrogen atom from the aromatic rings with 5 to 40 ring elements. The R... 4 The aromatic ring in the R is preferably at least one aromatic hydrocarbon ring selected from the group consisting of benzene ring, naphthalene ring, anthracene ring, ferroline ring, phenanthrene ring, pyrene ring, fluorene ring, perylene ring, and cardamom ring. a When substituents are present, the substituents that W may have are preferably used.

[0109] The R a Preferably, the base is represented by the formula (3-1) or formula (3-2) below.

[0110] [Chemistry 11]

[0111]

[0112] (In equations (3-1) and (3-2), X) 1 and X 2 Each of these is independently represented by one of the following equations (i), (ii), (iii), or (iv). 5 Ar 6 and Ar 7 Each is an aromatic ring with 6 to 20 substituted or unsubstituted ring elements, which, together with the two adjacent carbon atoms in formulas (3-1) and (3-2), forms a condensation ring structure. 1 and L 2 Each can be a single bond or a divalent organic group with an aromatic ring, either independently. (for the bonding of carbon atoms in W in the above formula (3))

[0113] [Chemistry 12]

[0114]

[0115] (In equation (i), R) 11 and R 12 Each can be independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. R 11 and R 12 At least one of them has -OR A .

[0116] In equation (ii), R 13It is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. R 14 It is a monovalent organogroup with 1 to 20 carbon atoms. R 13 and R 14 At least one of them has -OR A .

[0117] In equation (iii), R 15 For having -OR A Monovalent organic groups with 1 to 20 carbon atoms.

[0118] In equation (iv), R 16 It is a hydrogen atom or has -OR A Monovalent organic groups with 1 to 20 carbon atoms

[0119] In equations (3-1) and (3-2), Ar 5 Ar 6 and Ar 7 (Hereinafter, it is sometimes also expressed as "Ar") 5 ~Ar 7 "" are, independently, substituted or unsubstituted aromatic rings with 6 to 20 ring elements that form a condensation ring structure together with the two adjacent carbon atoms in formulas (3-1) and (3-2). As Ar 5 ~Ar 7 The aromatic rings with 6 to 20 ring elements in the formula (1) can preferably be Ar rings. 1 Aromatic rings with 6 to 20 ring elements are those with 5 to 40 ring elements.

[0120] As Ar 5 ~Ar 7 When substituents are present, the substituents that W may have are preferably used.

[0121] In equations (i), (ii), (iii), and (iv), R is... 11 R 12 R 13 R 14 R 15 and R 16 (Hereinafter, it is sometimes also expressed as "R") 11 ~R 16 The monovalent organic groups with carbon numbers 1 to 20 represented by ” can be listed as R in the above formula (1). 0 and R 1 The groups represented are those with 1 to 20 carbons in the monovalent organic groups with 1 to 40 carbons.

[0122] R in equation (i) 11 and R 12At least one of them, R in equation (ii) 13 and R 14 At least one of them, R in equation (iii) 15 and R in equation (iv) 16 Preferably, each has an aromatic ring having 5 to 40 ring elements. The aromatic ring having 5 to 40 ring elements is preferably Ar from formula (1). 1 The aromatic ring has 5 to 40 ring elements. In this case, it is preferable that at least one hydrogen atom of the aromatic ring is posited with -OR A Replacement. The -OR on the aromatic ring. A The quantity is preferably an integer from 1 to 4, more preferably an integer from 1 to 3, and even more preferably 1 or 2.

[0123] In equations (3-1) and (3-2), L is used as... 1 and L 2 The divalent organic groups with aromatic rings in the formula (1) can preferably be listed as Ar from the formula (1). 1 A substituted or unsubstituted group (hereinafter also referred to as "β group") is formed by removing two hydrogen atoms from an aromatic ring with 5 to 40 ring elements. As L 1 and L 2 The divalent organic group with an aromatic ring represented may also be the group (β) and the group derived from R. 11 ~R 16 The radical is formed by removing one hydrogen atom from a monovalent organic radical representing 1 to 20 carbon atoms. As L 1 and L 2 The divalent organic group having an aromatic ring is preferably an aryl group with 6 to 12 ring members, substituted or unsubstituted an alkene diyl group with 2 to 10 carbons, substituted or unsubstituted an alkynyl group with 2 to 10 carbons, or a combination thereof, more preferably a phenyldiyl group, a naphthyl group, an ethylenediyl group, an acetylene diyl group, or a combination thereof, and even more preferably a phenyldiyl group or a combination of a phenyldiyl group and an acetylene diyl group.

[0124] In equations (3-1) and (3-2), L 1 and L 2 Single bonds are preferred.

[0125] constituting the R A In the structure, the proportion of hydrogen atoms x, the proportion of monovalent heteroatom-containing groups with carbon numbers of 1 to 10 y, and the proportion of organic groups (A) z can be the same as those in the case of [A1] polymer.

[0126] As compounds containing an aromatic ring [A2], examples include compounds represented by formulas (3-1) to (3-8) below.

[0127] [Chemistry 13]

[0128]

[0129] [Chemistry 14]

[0130]

[0131] In the formula, R A As described above.

[0132] A typical method for synthesizing [A2] aromatic ring compounds involves first preparing, for example, a ketone or alkyne-substituted fluorene as a starting material, and then performing a cyclization reaction of the ketone or alkyne moiety in the presence of a catalyst to synthesize the basic skeletal moiety. Next, the 9-position of the fluorene is modified using an aldehyde compound with a phenolic hydroxyl group. Finally, the [A1] polymer is introduced into the fluorene ring using the same method as described above. A This allows for the production of compounds containing an aromatic ring [A2]. Other structures can also be synthesized by appropriately selecting starting materials or structures of ketone bodies, aldehyde compounds with phenolic hydroxyl groups, etc.

[0133] The content of compound [A] in the composition for forming the resist underlayer film, excluding the solvent, is 50% by mass or more. As a lower limit of this content, 60% by mass is preferred, more preferably 70% by mass, further preferably 80% by mass, and particularly preferably 90% by mass. As an upper limit of this content, 100% by mass is preferred (i.e., the composition for forming the resist underlayer film contains only compound [A] besides the solvent). When the composition for forming the resist underlayer film contains any component, as an upper limit of this content, 99% by mass is preferred, and more preferably 98% by mass.

[0134] As a lower limit for the content of compound [A] in the composition, it is preferably 0.01% by mass, more preferably 0.05% by mass, further preferably 0.1% by mass, and particularly preferably 0.5% by mass, in the total mass of compound [A] and solvent [B]. As an upper limit for the content, it is preferably 30% by mass, more preferably 20% by mass, further preferably 10% by mass, and particularly preferably 5% by mass, in the total mass of compound [A] and solvent [B].

[0135] <[B] Solvent>

[0136] [B] There are no particular limitations on the solvent if it can dissolve or disperse the [A] compound and any other components that may be present as needed.

[0137] Examples of solvents that can be classified as [B] include: hydrocarbon solvents, ester solvents, alcohol solvents, ketone solvents, ether solvents, nitrogen-containing solvents, etc. A single [B] solvent can be used alone, or two or more can be used in combination.

[0138] Examples of hydrocarbon solvents include: aliphatic hydrocarbon solvents such as n-pentane, n-hexane, and cyclohexane; and aromatic hydrocarbon solvents such as benzene, toluene, and xylene.

[0139] Examples of ester-based solvents include: carbonate solvents such as diethyl carbonate; monoacetic acid ester solvents such as methyl acetate and ethyl acetate; lactone solvents such as γ-butyrolactone; polyol partial ether carboxylic acid ester solvents such as diethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate; and lactate solvents such as methyl lactate and ethyl lactate.

[0140] Examples of alcohol-based solvents include: mono-alcohol solvents such as methanol, ethanol, and n-propanol; and poly-alcohol solvents such as ethylene glycol and 1,2-propanediol.

[0141] Examples of ketone solvents include: chain ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; cyclic ketone solvents such as cyclohexanone.

[0142] Examples of ether-based solvents include: chain ether solvents such as n-butyl ether; cyclic ether solvents such as tetrahydrofuran; and polyol ether solvents such as diethylene glycol monomethyl ether.

[0143] Examples of nitrogen-containing solvents include chain-like nitrogen-containing solvents such as N,N-dimethylacetamide and cyclic nitrogen-containing solvents such as N-methylpyrrolidone.

[0144] As the solvent for [B], ester-based solvents or ketone-based solvents are preferred, more preferably polyol partial ether carboxylic acid ester-based solvents or cyclic ketone-based solvents, and even more preferably propylene glycol monomethyl ether acetate or cyclohexanone.

[0145] The lower limit of the content of [B] solvent in the composition is preferably 50% by mass, more preferably 60% by mass, even more preferably 70% by mass, and particularly preferably 80% by mass. The upper limit of the content is preferably 99.99% by mass, more preferably 99.98% by mass, even more preferably 99.9% by mass, and particularly preferably 99.5% by mass.

[0146] [Any ingredients]

[0147] The film-forming composition may contain any component without impairing the effects of the present invention. Examples of such components include: acid generators, crosslinking agents, surfactants, sensitizers, defoamers, and other polymers different from the [A1] polymer. Any component may be used alone or in combination of two or more. As a defoamer, known defoamers may be used, such as: alcohol defoamers, phosphate ester defoamers, fatty acid ester defoamers, polyether defoamers, and silicone defoamers. Examples of fatty acid ester defoamers include: methyl laurate, methyl palmitate, methyl stearate, propyl butyrate, butyl butyrate, ethyl isovalerate, and isobutyl propionate, preferably propyl butyrate and butyl butyrate. Ketone solvents such as 2-heptanone may also be used as defoamers. Examples of other polymers include polymers having repeating units comprising a sulfonate structure and polymers having repeating units comprising a structure containing two perfluoroalkyl groups and a hydroxyl group bonded to one carbon atom.

[0148] [Preparation method of composition for forming resist underlayer film]

[0149] The composition for forming the resist underlayer film can be prepared by mixing [A] compound, [B] solvent, and any other components as needed in a specified proportion, preferably by filtering the obtained mixture using a membrane filter with a pore size of 0.5 μm or less.

[0150] [Silicone film formation process]

[0151] In this step, performed before the coating step (I), a silicon-containing film is formed directly or indirectly on the substrate. If the substrate has a pattern, this step is preferably omitted.

[0152] Examples of substrates include silicon substrates, aluminum substrates, nickel substrates, chromium substrates, molybdenum substrates, tungsten substrates, copper substrates, tantalum substrates, titanium substrates, and other metal or semi-metal substrates, among which silicon substrates are preferred. The substrate may also be a substrate on which a silicon nitride film, an aluminum oxide film, a silicon dioxide film, a tantalum nitride film, a titanium nitride film, etc., are formed.

[0153] Silicon-containing films can be formed by coating with a silicon-containing film forming composition, chemical vapor deposition (CVD), atomic layer deposition (ALD), etc. Examples of methods for forming silicon-containing films by coating with a silicon-containing film forming composition include directly or indirectly coating the silicon-containing film forming composition onto a resist underlayer, and then exposing and / or heating the formed coating film to harden it. Commercially available silicon-containing film forming compositions include, for example, "NFC SOG01," "NFC SOG04," and "NFC SOG080" (all manufactured by JSR Corporation). Silicon oxide films, silicon nitride films, silicon oxynitride films, and amorphous silicon films can be formed by chemical vapor deposition (CVD) or atomic layer deposition (ALD).

[0154] Examples of indirectly forming silicon-containing films on a substrate include low-dielectric insulating films formed on a substrate, metal hard masks (such as TiO2), and silicon-containing films formed on carbon films formed by CVD.

[0155] [Coating Process (I)]

[0156] In this process, a resist underlayer film forming composition is applied directly or indirectly onto a substrate. The application method for the resist underlayer film forming composition is not particularly limited; suitable methods such as spin coating, cast coating, and roll coating can be used. This forms a coating film, and the resist underlayer film is formed by the evaporation of the [B] solvent.

[0157] Furthermore, when the resist underlayer film forming composition is indirectly coated on the substrate, examples include coating the resist underlayer film forming composition on an organic underlayer film formed on a substrate without a pattern.

[0158] The substrate may have a pattern. In this case, it is preferable to directly apply the resist underlayer film forming composition onto the substrate. Because of its excellent embedding and flatness, the resist underlayer film forming composition can form a good resist underlayer film while embedding the gaps between the patterns, even when the substrate has a pattern. Examples of the shape of the pattern include, for example, trench patterns, line and space patterns, hole patterns, and pillar patterns. Examples of trench patterns and line and space patterns include, for example, patterns comprising recesses with a width of 5 nm or more and 100 nm or less, and a depth of 5 nm or more and 500 nm or less. Examples of hole patterns include, for example, patterns comprising holes with a diameter of 5 nm or more and 100 nm or less, and a depth of 5 nm or more and 500 nm or less. As a column pattern, for example, if it is a square column, patterns can be listed that include columns with one side having a diameter of 5 nm or more and 100 nm or less, and a height of 5 nm or more and 500 nm or less. If it is a cylinder, patterns can be listed that include columns with a diameter of 5 nm or more and 100 nm or less, and a height of 5 nm or more and 500 nm or less.

[0159] Next, the coating film formed by the coating process is heated. Heating the coating film promotes the formation of the resist underlayer film. More specifically, heating the coating film promotes the volatilization of solvent [B].

[0160] The heating of the coating film can be performed in an atmospheric environment or in a nitrogen environment. The lower limit of the heating temperature is preferably 200°C, more preferably 250°C, and even more preferably 300°C. The upper limit of the heating temperature is preferably 550°C, more preferably 500°C, and even more preferably 450°C. The lower limit of the heating time is preferably 15 seconds, more preferably 30 seconds. The upper limit of the heating time is preferably 1,200 seconds, more preferably 600 seconds.

[0161] Furthermore, the resist underlayer can be exposed after the coating process (I). Plasma can also be exposed to the resist underlayer after the coating process. Ion implantation can also be performed on the resist underlayer after the coating process. Exposure of the resist underlayer improves its etch resistance. Exposure of the resist underlayer to plasma improves its etch resistance. Ion implantation of the resist underlayer improves its etch resistance.

[0162] The radiation used in the exposure of the resist underlayer film can be appropriately selected from electromagnetic waves such as visible light, ultraviolet light, far ultraviolet light, X-rays, and gamma rays; and particle beams such as electron beams, molecular beams, and ion beams.

[0163] Methods for exposing the resist underlayer to plasma include, for example, the direct method based on placing the substrate in various gas environments and performing plasma discharge. The conditions for plasma exposure typically include a gas flow rate of 50 cc / min or more and 100 cc / min or less, and a power supply of 100 W or more and 1,500 W or less.

[0164] The lower limit for plasma exposure time is preferably 10 seconds, more preferably 30 seconds, and even more preferably 1 minute. The upper limit for said time is preferably 10 minutes, more preferably 5 minutes, and even more preferably 2 minutes.

[0165] Regarding plasma, plasma can be generated, for example, in an environment containing a mixture of H2 and Ar gases. In addition to H2 and Ar gases, carbon-containing gases such as CF4 or CH4 can also be introduced. Furthermore, at least one of CF4, NF3, CHF3, CO2, CH2F2, CH4, and C4F8 gases can be introduced to replace either or both of H2 and Ar gases.

[0166] Ion implantation into the resist underlayer involves implanting a dopant into the resist underlayer. Dopant can be selected from the group consisting of boron, carbon, nitrogen, phosphorus, arsenic, aluminum, and tungsten. The implantation energy used to apply a voltage to the dopant ranges from approximately 0.5 keV to 60 keV, depending on the type of dopant used and the desired implantation depth.

[0167] The lower limit of the average thickness of the formed resist underlayer film is preferably 1 nm, more preferably 3 nm, and even more preferably 5 nm. The upper limit of the average thickness is preferably 500 nm, more preferably 200 nm, and even more preferably 100 nm. Furthermore, the method for measuring the average thickness is as described in the examples.

[0168] [Coating Process (II)]

[0169] In this process, the resist film forming composition is applied directly or indirectly to the resist underlayer film formed by the resist underlayer film forming composition coating process. There are no particular limitations on the coating method for the resist film forming composition; for example, spin coating can be used.

[0170] As an example of indirectly applying a composition for forming a resist film onto the resist underlayer film, the case of applying the composition for forming a resist film onto a surface-modified film formed on the resist underlayer film can be cited.

[0171] If this process is described in more detail, for example, after applying the resist film forming composition in such a way that the formed resist film becomes a specified thickness, a prebake (hereinafter also referred to as "PB") is performed, thereby causing the solvent in the coated film to evaporate, thereby forming the resist film.

[0172] The photoresist film forming temperature and time can be appropriately determined according to the type of photoresist film forming composition used. The lower limit of the photoresist film forming temperature is preferably 30°C, more preferably 50°C. The upper limit of the photoresist film forming temperature is preferably 200°C, more preferably 150°C. The lower limit of the photoresist film forming time is preferably 10 seconds, more preferably 30 seconds. The upper limit of the photoresist film forming time is preferably 600 seconds, more preferably 300 seconds.

[0173] The resist film forming composition used in this process is preferably a composition that is exposed using extreme ultraviolet light, such as: a positive or negative chemical amplification resist composition containing a radiosensitive linear acid generator, or a metal-containing resist composition containing metals such as tin, zirconium, or hafnium.

[0174] [Exposure Process]

[0175] In this process, the resist film formed by the resist film forming composition coating process is exposed to extreme ultraviolet light (EUV). The exposure conditions can be appropriately determined depending on the type of resist film forming composition used.

[0176] In addition, in this process, after the exposure, post-exposure bake (hereinafter also referred to as "PEB") can be performed to improve the properties of the resist film, such as resolution, pattern outline, and developability. The PEB temperature and PEB time can be appropriately determined according to the type of resist film forming composition used. The lower limit of the PEB temperature is preferably 50°C, more preferably 70°C. The upper limit of the PEB temperature is preferably 200°C, more preferably 150°C. The lower limit of the PEB time is preferably 10 seconds, more preferably 30 seconds. The upper limit of the PEB time is preferably 600 seconds, more preferably 300 seconds.

[0177] [Developing process]

[0178] In this process, the exposed resist film is developed. At this time, a portion of the resist underlayer may also be developed. Examples of developers used in this development process include alkaline aqueous solutions (alkaline developers) and liquids containing organic solvents (organic solvent developers).

[0179] There are no particular limitations on the alkaline solution used for alkaline development, and known alkaline solutions can be used. Examples of alkaline solutions for alkaline development include aqueous solutions containing at least one of the following alkaline compounds: sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyl diethylamine, ethyl dimethylamine, triethanolamine, tetramethyl ammonium hydroxide (TMAH), pyrrole, piperidine, choline, 1,8-diazabicyclo-[5.4.0]-7-undecene, and 1,5-diazabicyclo-[4.3.0]-5-nonene. Among these, an aqueous solution of TMAH is preferred, and a 2.38% by mass aqueous solution of TMAH is more preferred.

[0180] Organic solvent developers used in organic solvent development include, for example, those similar to those exemplified as the [B] solvent described above. Preferably, organic solvents are ester-based, ether-based, alcohol-based, ketone-based, and / or hydrocarbon-based solvents, more preferably ketone-based solvents, and particularly preferably 2-heptanone.

[0181] In this process, cleaning and / or drying may also be performed after development.

[0182] [Etching Process]

[0183] Subsequently, etching can be performed using the resist pattern (and resist underlayer pattern) formed in the development process as a mask. The number of etching operations can be one or multiple times; that is, the pattern obtained through etching can be used as a mask for sequential etching. From the viewpoint of obtaining a better pattern shape, multiple etching operations are preferred. From the viewpoint of improving the shape of the substrate pattern, dry etching is preferred. In the dry etching, gas plasmas such as oxygen plasma can be used. Through this etching, a semiconductor substrate with a predetermined pattern can be obtained.

[0184] Dry etching can be performed using, for example, a known dry etching apparatus. The etching gas used in dry etching can be appropriately selected based on the mask pattern and the elemental composition of the film being etched. Examples include: fluorine-based gases such as CHF3, CF4, C2F6, C3F8, and SF6; chlorine-based gases such as Cl2 and BCl3; oxygen-based gases such as O2, O3, and H2O; reducing gases such as H2, CO, CO2, CH4, C2H2, C2H4, C2H6, C3H4, C3H6, and C3H8; reducing gases such as HF, HI, HBr, HCl, NO, NH3, and BCl3; and inert gases such as He, N2, and Ar. These gases can also be mixed. When etching the substrate using the pattern of the resist underlayer as a mask, fluorine-based gases are typically used.

[0185] Example

[0186] The present invention will now be described in detail based on embodiments, but the present invention is not limited to these embodiments.

[0187] [Weight-average molecular weight (Mw), Number-average molecular weight (Mn)]

[0188] The Mw and Mn of the polymer were determined using gel permeation chromatography (GPC) columns (two “G2000HXL” and one “G3000HXL”) from Tosoh Co., Ltd., under analytical conditions of flow rate: 1.0 mL / min, dissolution solvent: tetrahydrofuran, and column temperature: 40 °C, by gel permeation chromatography with monodisperse polystyrene as the standard (detector: differential refractometer).

[0189] [Modification rate of phenolic hydroxyl groups]

[0190] The modification rate of phenolic hydroxyl groups in compound [A] is calculated based on the number of hydroxyl groups in the starting materials used in the synthesis and the number of modifying agents used in the modification of phenolic hydroxyl groups.

[0191] [Average membrane thickness]

[0192] The average thickness of the film was determined by measuring the film thickness at any 9 points at a 5 cm interval, including the center, on the resist underlayer film formed on the silicon wafer (substrate) using a spectroellipsomerometer (JA WOOLLAM's "M2000D"). The average thickness of these film thicknesses was then calculated.

[0193] <[A] Synthesis of Compound>

[0194] The following procedures are used to synthesize compounds (p-1) to (p-5) which serve as the starting materials for the synthesis of compound [A].

[0195] [Synthetic Example 1-1] (Synthesis of compound (p-1))

[0196] Under nitrogen atmosphere, 10.0 g of 2,7-dihydroxynaphthalene, 6.6 g of benzaldehyde, and 49.8 g of 1-butanol were added to a reaction vessel, stirred, and the compounds were dissolved. An 8.8 g solution of 2.4 g of p-toluenesulfonic acid monohydrate in 1-butanol was added to the reaction vessel, and the mixture was heated to 110°C and reacted for 12 hours. After the reaction was complete, the reaction solution was transferred to a separatory funnel, and 100 g of methyl isobutyl ketone and 200 g of water were added to wash the organic phase. After separating the aqueous phase, the obtained organic phase was washed several times with water. The solution was then concentrated using an evaporator, and the residue was added dropwise to 100 g of methanol to obtain a precipitate. The precipitate was recovered by suction filtration and washed several times with 50 g of methanol. The precipitate was then dried in a vacuum dryer at 60°C for 12 hours to obtain compound (p-1) having the repeating unit represented by the following formula (p-1). The Mw of compound (p-1) is 2560.

[0197] [Chemistry 15]

[0198]

[0199] [Synthetic Examples 1-2] (Synthesis of compound (p-2))

[0200] Using 13.7 g of 1-hydroxypyrene instead of 10.0 g of 2,7-dihydroxynaphthalene, and 8.7 g of 3,4-dihydroxybenzaldehyde instead of 6.6 g of benzaldehyde, the reaction was carried out under the same conditions as in [Synthetic Example 1-1], thereby obtaining compound (p-2) having the repeating unit represented by the following formula (p-2). The Mw of compound (p-2) is 3800.

[0201] [Chemistry 16]

[0202]

[0203] [Synthetic Examples 1-3] (Synthesis of compound (p-3))

[0204] 18.1 g of 1,1-bis(4-hydroxyphenyl)-1-phenylethane was used instead of 10.0 g of 2,7-dihydroxynaphthalene, and 8.7 g of 2,4-dihydroxybenzaldehyde was used instead of 6.6 g of benzaldehyde, except that the reaction was carried out under the same conditions as in [Synthetic Example 1-1], thereby obtaining compound (p-3) having the repeating unit represented by the following formula (p-3). The Mw of compound (p-3) is 4150.

[0205] [Chemistry 17]

[0206]

[0207] [Synthetic Examples 1-4] (Synthesis of compound (p-4))

[0208] Under nitrogen atmosphere, 10.0 g of 1,3,5-benzyltri-9H-fluorene, 7.1 g of 4-hydroxybenzaldehyde, and 60.0 g of dimethylacetamide were added to a reaction vessel to suspend the mixture. 8.8 g of diazabicycloundecene was then added, and the reaction was carried out at 120°C for 12 hours. After the reaction was complete, 300.0 g of methyl isobutyl ketone and 200.0 g of 5% oxalic acid aqueous solution were added to separate the organic phase. The organic phase was washed several times with water, concentrated using an evaporator, and added dropwise to 200 g of methanol to obtain a precipitate. The precipitate was recovered by suction filtration and washed several times with 50.0 g of methanol. Subsequently, it was dried in a vacuum dryer at 60°C for 12 hours to obtain the compound (p-4) represented by the following formula (p-4).

[0209] [Chemistry 18]

[0210]

[0211] [Synthetic Examples 1-5] (Synthesis of compound (p-5))

[0212] Using 8.0 g of 3,4-dihydroxybenzaldehyde instead of 7.1 g of 4-hydroxybenzaldehyde, the reaction was carried out under the same conditions as in [Synthetic Examples 1-4], thereby obtaining the compound represented by the following formula (p-5) (p-5).

[0213] [Chemistry 19]

[0214]

[0215] As modifiers for the phenolic hydroxyl groups of compound [A], compounds (a-1) to (a-8), (b-1) to (b-3), (c-1) to (c-4), and (d-1) to (d-2) are used. Furthermore, compounds (a-1) to (a-8), (b-1) to (b-3), and (c-1) to (c-4) provide heteroatom-containing groups, and compounds (d-1) to (d-2) provide organic groups other than the heteroatom-containing groups (i.e., organic group (A)).

[0216] [Chemistry 20]

[0217]

[0218] [Chemistry 21]

[0219]

[0220] [Chemistry 22]

[0221]

[0222] [Chemistry 23]

[0223]

[0224] The [A] compound was synthesized using the procedure shown below.

[0225] [Synthetic Example 2-1] (Synthesis of compound (A-1))

[0226] Under nitrogen atmosphere, 10.0 g of compound (p-1) was dissolved in 50.0 g of tetrahydrofuran in a reaction vessel, cooled to below 10°C, and 3.12 g of N,N-diisopropylethylamine was added. 1.95 g of chloromethyl methyl ether (a-1) was added dropwise, and the mixture was allowed to react at room temperature for 1 hour. After the reaction was complete, the reaction solution was transferred to a separatory funnel, and 150 g of methyl isobutyl ketone and 200 g of water were added to wash the organic phase. After separating the aqueous phase, the obtained organic phase was washed several times with water. The solution was then concentrated using an evaporator, and the residue was added dropwise to 150 g of methanol to obtain a precipitate. The precipitate was recovered by suction filtration and washed several times with 50 g of methanol. Finally, the solution was dried in a vacuum dryer at 60°C for 12 hours to obtain compound (A-1). In the formula, the values ​​represent the constituents of R. A The proportion of hydrogen atoms x and the proportion of heteroatom-containing groups as modifying groups y (and the proportion of organic groups (A) z (in the presence of them)). This is a bond formed with an oxygen atom. The same applies to the following formulas.

[0227] [Chemistry 24]

[0228]

[0229] [Synthesis Examples 2-2 to 2-6, Synthesis Examples 2-11 to 2-13] (Synthesis of compounds (A-2) to (A-6), (A-11) to (A-13))

[0230] Using the modifiers shown in Table 1, compounds (A-2) to (A-6), and compounds (A-11) to (A-13) were obtained as products under the same reaction conditions as in Synthesis Example A-1.

[0231] [Chemistry 25]

[0232]

[0233] [Chemistry 26]

[0234]

[0235] [Synthetic Examples 2-7] (Synthesis of compound (A-7))

[0236] Under nitrogen atmosphere, 10.0 g of compound (p-1) was dissolved in 50.0 g of tetrahydrofuran in a reaction vessel, 0.49 g of N,N-dimethylaminopyridine was added, and 2.47 g of acetic anhydride (b-1) was added dropwise. The reaction was carried out at 50 °C for 1 hour. After the reaction was completed, the reaction solution was transferred to a separatory funnel, and 150 g of methyl isobutyl ketone and 200 g of water were added to wash the organic phase. After separating the aqueous phase, the obtained organic phase was washed several times with water. Then, the solution was concentrated using an evaporator, and the residue was added dropwise to 150 g of methanol to obtain a precipitate. The precipitate was recovered by suction filtration and washed several times with 50 g of methanol. Then, the solution was dried in a vacuum dryer at 60 °C for 12 hours to obtain compound (A-7) having the repeating unit represented by the following formula (A-7).

[0237] [Chemistry 27]

[0238]

[0239] [Synthetic Examples 2-8] (Synthesis of compound (A-8))

[0240] Using the modifiers shown in Table 1, except under the same reaction conditions as in Synthetic Examples 2-7, compound (A-8) was obtained as the product.

[0241] [Chemistry 28]

[0242]

[0243] [Synthetic Examples 2-9] (Synthesis of compound (A-9))

[0244] Under nitrogen atmosphere, 10.0 g of compound (p-1) was dissolved in 50.0 g of tetrahydrofuran in a reaction vessel, 1.74 g of ethyl vinyl ether (c-1) was added, and 0.61 g of pyridinium p-toluenesulfonate was added dropwise. The reaction was carried out at 50 °C for 3 hours. After the reaction was completed, the reaction solution was transferred to a separatory funnel, and 150 g of methyl isobutyl ketone and 200 g of water were added to wash the organic phase. After separating the aqueous phase, the obtained organic phase was washed several times with water. Then, the solution was concentrated using an evaporator, and the residue was added dropwise to 150 g of methanol to obtain a precipitate. The precipitate was recovered by suction filtration and washed several times with 50 g of methanol. Then, the solution was dried in a vacuum dryer at 60 °C for 12 hours to obtain compound (A-9) having the repeating unit represented by the following formula (A-9).

[0245] [Chemistry 29]

[0246]

[0247] [Synthetic Example 2-10] (Synthesis of compound (A-10))

[0248] Using the modifiers shown in Table 1, except under the same reaction conditions as in Synthetic Examples 2-9, compound (A-10) was obtained as a product.

[0249] [Chemistry 30]

[0250]

[0251] [Synthetic Example 2-14] (Synthesis of compound (A-14))

[0252] Under nitrogen atmosphere, 10.0 g of compound (p-1) was dissolved in 50.0 g of tetrahydrofuran in a reaction vessel, cooled to below 10°C, and 8.33 g of N,N-diisopropylethylamine was added. 1.30 g of chloromethyl methyl ether (a-1) was added dropwise, and the mixture was allowed to react at room temperature for 1 hour. Then, 2.87 g of brominated propargyl (d-1) was added dropwise, and the reaction was carried out at 60°C for 2 hours. After the reaction was complete, the reaction solution was transferred to a separatory funnel, and 150 g of methyl isobutyl ketone and 200 g of water were added to wash the organic phase. After separating the aqueous phase, the obtained organic phase was washed several times with water. The solution was then concentrated using an evaporator, and the residue was added dropwise to 150 g of methanol to obtain a precipitate. The precipitate was recovered by suction filtration and washed several times with 50 g of methanol. Subsequently, the compound was dried in a vacuum dryer at 60°C for 12 hours to obtain a compound (A-14) having a repeating unit represented by the following formula (A-14).

[0253] [Chemistry 31]

[0254]

[0255] [Synthetic Examples 2-15, 2-28 to 2-29] (Synthesis of compounds (A-15), (A-28) to (A-29))

[0256] Using the compounds and modifiers shown in Table 1, compounds (A-15), (A-28), and (A-29) were obtained as products under the same reaction conditions as in Synthetic Examples 2-14.

[0257] [Chemistry 32]

[0258]

[0259] [Chemistry 33]

[0260]

[0261] [Synthetic Examples 2-16 to 2-21] (Synthesis of compounds (A-16) to (A-21))

[0262] Using the compounds and modifiers shown in Table 1, compounds (A-16) to (A-21) were obtained as products under the same reaction conditions as in Synthesis Example 2-1.

[0263] [Chemistry 34]

[0264]

[0265] [Chemistry 35]

[0266]

[0267] [Chemistry 36]

[0268]

[0269] [Synthetic Examples 2-22] (Synthesis of compound (A-22))

[0270] Using the compounds and modifiers shown in Table 1, except under the same reaction conditions as in Synthetic Examples 2-7, compound (A-22) was obtained as a product.

[0271] [Chemistry 37]

[0272]

[0273] [Synthetic Examples 2-23 to 2-24] (Synthesis of compounds (A-23) to (A-24))

[0274] Using the compounds and modifiers shown in Table 1, compounds (A-23) to (A-24) were obtained as products under the same reaction conditions as in Synthetic Examples 2-9.

[0275] [Chemistry 38]

[0276]

[0277] [Synthetic Examples 2-25 to 2-27, Synthetic Examples 2-30 to 2-31] (Synthesis of compounds (A-25) to (A-27), (A-30) to (A-31))

[0278] Using the compounds and modifiers shown in Table 1, compounds (A-25) to (A-27) and compounds (A-30) to (A-31) were obtained as products under the same reaction conditions as in Synthesis Example A-1.

[0279] [Chemistry 39]

[0280]

[0281] [Chemistry 40]

[0282]

[0283] [Chemistry 41]

[0284]

[0285] [Table 1]

[0286]

[0287] <Preparation of the Composition>

[0288] The following shows the [A] compound, comparative compound, [B] solvent, [C] acid generating agent, [D] crosslinking agent, and [E] other polymers used in the preparation of the composition.

[0289] [[A]compound]

[0290] A-1 to A-31: The synthesized compounds (A-1) to (A-31).

[0291] [Compare compounds]

[0292] p-1: The synthesized compound (p-1)

[0293] p-5: The synthesized compound (p-5)

[0294] [[B]solvent]

[0295] B-1: Propylene glycol monomethyl ether acetate

[0296] B-2: Cyclohexanone

[0297] [[C] Acid generating agent]

[0298] C-1: The compound represented by the following formula (C-1)

[0299] [Chemistry 42]

[0300]

[0301] [[D] Crosslinking agent]

[0302] D-1: The compound represented by the following formula (D-1)

[0303] [Chemistry 43]

[0304]

[0305] D-2: The compound represented by the following formula (D-2)

[0306] [Chemistry 44]

[0307]

[0308] D-3: The compound represented by the following formula (D-3)

[0309] [Chemistry 45]

[0310]

[0311] D-4: The compound represented by the following formula (D-4)

[0312] [Chemistry 46]

[0313]

[0314] D-5: The compound represented by the following formula (D-5)

[0315] [Chemistry 47]

[0316]

[0317] D-6: The compound represented by the following formula (D-6)

[0318] [Chemistry 48]

[0319]

[0320] D-7: The compound represented by the following formula (D-7)

[0321] [Chemistry 49]

[0322]

[0323] D-8: The compound represented by the following formula (D-8)

[0324] [Transformation 50]

[0325]

[0326] D-9: The compound represented by the following formula (D-9)

[0327] [Chemistry 51]

[0328]

[0329] D-10: The compound represented by the following formula (D-10)

[0330] [Chemistry 52]

[0331]

[0332] D-11: The compound represented by the following formula (D-11)

[0333] [Chemistry 53]

[0334]

[0335] D-12: The compound represented by the following formula (D-12)

[0336] [Chemistry 54]

[0337]

[0338] D-13: The compound represented by the following formula (D-13)

[0339] [Chemistry 55]

[0340]

[0341] D-14: The compound represented by the following formula (D-14)

[0342] [Chemistry 56]

[0343]

[0344] D-15: The compound represented by the following formula (D-15)

[0345] [Chemistry 57]

[0346]

[0347] D-16: The compound represented by the following formula (D-16)

[0348] [Chem.58]

[0349]

[0350] [E] Other polymers

[0351] E-1: A polymer having repeating units represented by the following formula (E-1) (Mw: 2500)

[0352] E-2: A polymer having repeating units represented by the following formula (E-2) (Mw: 3000)

[0353] E-3: A polymer having repeating units represented by the following formula (E-3) (Mw: 3500)

[0354] [Chemistry 59]

[0355]

[0356] [Example 1-1]

[0357] Two parts by mass of compound (A-1) as [A] were dissolved in 98 parts by mass of solvent (B-1) as [B]. The resulting solution was filtered using a polytetrafluoroethylene (PTFE) membrane filter with a pore size of 0.45 μm to prepare composition (J-1).

[0358] [Examples 1-2 to 1-61 and Comparative Examples 1-1 to 1-2]

[0359] Compositions (J-2) to (J-61) and compositions (CJ-1) to (CJ-2) were prepared in the same manner as in Examples 1-1, except that the types and amounts of each component shown in Tables 2-1 and 2-2 below were used. “-” in Table 2 indicates that the corresponding component was not used.

[0360] [Table 2-1]

[0361]

[0362] [Table 2-2]

[0363]

[0364] <Evaluation>

[0365] The embedment and flatness of the prepared composition were evaluated using the following methods. The evaluation results are shown in Table 3 below.

[0366] [Embedded]

[0367] The composition was applied to a substrate with a trench pattern having a depth of 65 nm and a width of 20 nm using a spin coater (Tokyo Electron, Ltd.'s "LITHIUS Pro Z") by spin coating. The spin coater was set to conditions such as those required to obtain a substrate with a film having an average thickness of 100 nm. Next, the substrate was heated to 400°C for 90 seconds under atmospheric conditions and then cooled to 23°C for 60 seconds. The cross-sectional shape of the substrate was observed (200,000x magnification) using a scanning electron microscope (Hitachi High-technologies, Ltd.'s "S-4800"), and the embedding performance was evaluated. Regarding embedding performance, the case where the resist underlayer was embedded to the bottom of the spatial pattern of the substrate (without gaps) was rated as "A" (good), and the case where the resist underlayer was not embedded to the bottom of the spatial pattern (with gaps) was rated as "B" (bad).

[0368] Flatness

[0369] Using a spin coater (Tokyo Electron Inc.'s "CLEAN TRACK ACT12"), the prepared composition was applied by spin coating as follows. Figure 1 The resist underlayer film 2 is coated onto a silicon substrate 1 having a trench pattern with a depth of 150 nm and a width of 10 μm. Next, under atmospheric conditions, it is heated at 250°C for 60 seconds and then cooled at 23°C for 60 seconds, thereby forming a resist underlayer film 2 with an average thickness of 200 nm in the non-trench pattern portion. Then, under atmospheric conditions, it is heated at 350°C for 60 seconds and then cooled at 23°C for 60 seconds, thus obtaining a silicon substrate with a resist underlayer film. The cross-sectional shape of the silicon substrate with the resist underlayer film is observed using a scanning electron microscope (Hitachi High-technologies, Inc.'s "S-4800"). The difference (ΔFT) between the height of the central portion b of the trench pattern and the height of the non-trench pattern portion a located 5 μm from the end of the trench pattern is set as an index of flatness. When the ΔFT is less than 20 nm, the flatness evaluation is "A" (good); when it is greater than 20 nm, the flatness evaluation is "B" (poor). Furthermore, Figure 1 The height difference shown is exaggerated compared to the actual difference.

[0370] <Evaluation>

[0371] Using the prepared composition, the rectangularity of the resist pattern exposed by EUV was evaluated by the following method. The evaluation results are shown in Table 3 below.

[0372] <Preparation of the resist composition (R-1)>

[0373] The compound (S-1) used in the preparation of the resist composition (R-1) was synthesized using the following procedure. In a reaction vessel, 6.5 parts by weight of isopropyltin trichloride were added while stirring 150 mL of a 0.5 N sodium hydroxide aqueous solution for 2 hours. The precipitate was filtered off, washed twice with 50 parts by weight of water, and then dried to obtain compound (S-1). Compound (S-1) is the hydroxide oxidative product of the hydrolysis product of isopropyltin trichloride (i-PrSnO). (3 / 2-x / 2) (OH) x (0 < x < 3) is set as a structural unit.

[0374] Two parts by mass of the synthesized compound (S-1) and 98 parts by mass of propylene glycol monoethyl ether were mixed. The resulting mixture was then filtered through an activated 4 Å molecular sieve to remove residual water, and finally filtered using a filter with a pore size of 0.2 μm to prepare the resist composition (R-1).

[0375] [Pattern Rectangularity (EUV Exposure)]

[0376] The composition was applied to a 12-inch silicon wafer, heated at 220°C for 60 seconds, and then cooled at 23°C for 30 seconds to form a resist underlayer film with an average thickness of 5 nm. The resist composition (R-1) was then applied to the resist underlayer film using a spin coater, and after a predetermined time, heated at 90°C for 60 seconds and then cooled at 23°C for 30 seconds to form a resist film with an average thickness of 35 nm. The resist film was exposed using an EUV scanner (ASML's "TWINSCAN NXE:3300B" (NA 0.3, sigma 0.9, quadrupole illumination, 1-to-1 line-to-space mask with a linewidth of 16 nm on the wafer). After exposure, the substrate was heated at 110°C for 60 seconds and then cooled at 23°C for 60 seconds. Subsequently, it was developed using 2-heptanone (20°C–25°C) via a liquid coating method and then dried to obtain an evaluation substrate with a resist pattern. The length of the resist pattern on the evaluation substrate was measured and observed using a scanning electron microscope (Hitachi High-tech's "CG-6300"). Regarding pattern rectangularity, a rectangular cross-sectional shape was rated "A" (good), and a pattern with a sloping hem was rated "B" (bad).

[0377] [Table 3-1]

[0378]

[0379] [Table 3-2]

[0380]

[0381] According to the results in Tables 3-1 and 3-2, compared with the comparative examples, the composition of the examples and the resist underlayer film formed from the compositions exhibit superior pattern rectangularity. Furthermore, compared with the comparative examples, the composition of the examples and the resist underlayer film formed from the compositions also exhibit superior embedding and flatness.

[0382] Industrial availability

[0383] According to the semiconductor substrate manufacturing method of the present invention, a resist underlayer film with excellent pattern rectangularity is formed, thus obtaining a well-patterned semiconductor substrate. The resist underlayer film forming composition of the present invention can form a resist underlayer film with excellent pattern rectangularity. Furthermore, according to the semiconductor substrate manufacturing method of the present invention, a resist underlayer film with excellent embedding properties, not only sufficient embedding of the pattern into the substrate, but also excellent flatness after embedding, can be formed. The resist underlayer film forming composition of the present invention can form a resist underlayer film with excellent embedding properties and flatness. Therefore, these are preferably used in the manufacture of semiconductor devices intended for further miniaturization in the future.

[0384] Explanation of icon numbers

[0385] 1: Silicon substrate

[0386] 2: Resist underlayer film

Claims

1. A method for manufacturing a semiconductor substrate, comprising: The process of directly or indirectly coating a composition for forming a resist underlayer film on a substrate; A process of directly or indirectly coating a resist film forming composition onto a resist underlayer film formed by the resist underlayer film forming composition coating process; The process of exposing the resist film formed by the resist film forming composition coating process; and At least a development process is required for the exposed resist film. The composition for forming the resist underlayer film comprises: Compounds; as well as solvent, The compound has -OR A R A The R is any one of a hydrogen atom, a monovalent heteroatom-containing group having 1 to 10 carbon atoms, or a monovalent organic group having 1 to 10 carbon atoms (excluding the monovalent heteroatom-containing group having 1 to 10 carbon atoms). A In the structure, with the proportion of hydrogen atoms set as x, the proportion of monovalent heteroatom-containing groups having 1 to 10 carbon atoms set as y, and the proportion of monovalent organic groups having 1 to 10 carbon atoms set as z, the compound as a whole satisfies the relationship x + y + z = 100 and 20 ≦ x ≦ 95, 5 ≦ y ≦ 80. The compound is a polymer having repeating units represented by the following formula (1), having a molecular weight of 750 or more and 3000 or less, and having -OR A Compounds containing aromatic rings, or combinations thereof; [Chemistry 1] (In formula (1), Ar) 1 It is a divalent group having an aromatic ring with 5 to 40 ring elements; R 0 It is a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms; R 1 It is a monovalent organogroup with carbon numbers from 1 to 40; selected from Ar 1 R 0 and R 1 At least one of the groups formed has -OR A ).

2. The method for manufacturing a semiconductor substrate according to claim 1, wherein the heteroatom-containing group has at least one selected from the group consisting of -O-, -CO-, -S-, -SO2-, -NR'- (R' is a monovalent organic group), -NO2 and -CN.

3. The method for manufacturing a semiconductor substrate according to claim 1, wherein the heteroatom-containing base has at least one oxygen atom.

4. The method for manufacturing a semiconductor substrate according to any one of claims 1 to 3, wherein the aromatic ring is at least one aromatic hydrocarbon ring selected from the group consisting of benzene ring, naphthalene ring, anthracene ring, ferrocyanine ring, phenanthrene ring, pyrene ring, fluorene ring and perylene ring.

5. A method for manufacturing a semiconductor substrate according to any one of claims 1 to 3, wherein the substrate has a pattern.

6. The method for manufacturing a semiconductor substrate according to any one of claims 1 to 3, wherein the resist film contains a metal.

7. A composition for forming a resist underlayer film, comprising: Compounds; and solvent, The compound has -OR A R A It is a hydrogen atom, a monovalent heteroatom-containing group having 1 to 10 carbon atoms, or a monovalent organic group having 1 to 10 carbon atoms (wherein, Any of the following groups (excluding those with 1 to 10 carbon atoms and containing monovalent heteroatoms) constituting the R A In the structure, with the proportion of hydrogen atoms set as x, the proportion of monovalent heteroatom-containing groups having 1 to 10 carbon atoms set as y, and the proportion of monovalent organic groups having 1 to 10 carbon atoms set as z, the compound as a whole satisfies the relationship x + y + z = 100 and 20 ≦ x ≦ 95, 5 ≦ y ≦ 80. The compound is a polymer having repeating units represented by the following formula (1), having a molecular weight of 750 or more and 3000 or less, and having -OR A Compounds containing aromatic rings, or combinations thereof; [Chemistry 2] (In formula (1), Ar) 1 It is a divalent group having an aromatic ring with 5 to 40 ring elements; R 0 It is a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms; R 1 It is a monovalent organogroup with carbon numbers from 1 to 40; selected from Ar 1 R 0 and R 1 At least one of the groups formed has -OR A ).

8. The composition for forming a resist underlayer film according to claim 7, wherein the heteroatom-containing group has at least one selected from the group consisting of -O-, -CO-, -S-, -SO2-, -NR'- (R' is a monovalent organic group), -NO2 and -CN.

9. The composition for forming a resist underlayer film according to claim 7, wherein the heteroatom-containing group has at least one oxygen atom.

10. The composition for forming a resist underlayer film according to any one of claims 7 to 9, wherein the aromatic ring is at least one aromatic hydrocarbon ring selected from the group consisting of benzene ring, naphthalene ring, anthracene ring, ferrocyanine ring, phenanthrene ring, pyrene ring, fluorene ring and perylene ring.

11. The resist underlayer film forming composition according to any one of claims 7 to 9, for pattern embedding of a patterned substrate.

12. The composition for forming a resist underlayer film according to any one of claims 7 to 9, for forming an underlayer film of a metal-containing resist film.

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