Non-chemically amplified negative resist composition, and method for manufacturing a resist pattern using the resist composition and mold

Abstract

To provide a non-chemical amplification type negative resist composition useful for fine processing, and a manufacturing method of a resist pattern using the resist composition, and a mold.SOLUTION: A negative resist composition is a non-chemical amplification type and includes: a phenolic compound (A) with a molecular weight of 400 to 2500, having two or more phenolic hydroxyl groups in one molecule, and two or more substituent groups of one or more kinds selected from a group composed of a hydroxymethyl group and an alkoxymethyl group at an ortho position of a phenolic hydroxyl group, in one molecule; and a nitrogen-containing basic compound (B) with a molecular weight of 400 to 3000, having one or more aromatic rings in one molecule and one or more phenolic hydroxyl groups and / or phenoxy groups in one molecule. A content of the phenolic compound (A) is 70 mass% or more in a total solid of the negative resist composition. The negative resist composition includes substantially no acid generator.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This disclosure relates to a non-chemically amplified negative resist composition useful for microfabrication, and to a method for manufacturing a resist pattern using the resist composition and a mold. [Background technology]

[0002] In recent years, advances in lithography technology have led to rapid miniaturization of patterns in the manufacturing of semiconductor and display elements, creating a demand for high resolution. As a method for miniaturization, the wavelength of the exposure light source is generally shortened. In addition to the KrF excimer laser light currently in use, lithography using ArF, F2, EUV, X-rays, electron beams, and other charged particle beams as exposure light has been proposed.

[0003] In particular, electron beam and EUV lithography are positioned as next-generation or next-next-generation lithography technologies, and there is a demand for the development of negative resists that meet the requirements for high sensitivity and high resolution for creating gate layers in semiconductor integrated circuits and for processing mask patterns formed on glass substrates. Furthermore, there is a demand for the development of resists with high resolution for the manufacture of imprint molds, which are the master plates for imprint lithography.

[0004] For resist materials used against these materials, chemically amplified photosensitive compositions that utilize acid catalytic reactions are employed to improve sensitivity. Negative-type chemically amplified photosensitive compositions typically contain an alkali-soluble resin, which serves as the resist substrate, along with an acid generator that generates acid upon irradiation with light, a crosslinking agent, and a basic compound. In such photosensitive compositions, crosslinking occurs between the resin and the crosslinking agent due to the action of acid generated from the acid generator upon exposure, changing the composition from alkali-soluble to alkali-insoluble. Furthermore, the acid generated during the crosslinking reaction catalytically repeats the reaction, enabling pattern exposure with less exposure.

[0005] Conventionally, semiconductor lithography has used resist materials made from polymers with a mass-average molecular weight of approximately 5000 or more as the alkali-soluble resin that serves as the resist substrate. However, because such polymer materials have large molecular weights and a broad molecular weight distribution, there are limits to how much resolution can be reduced. Therefore, development of low-molecular-weight materials has been underway to use alkali-soluble resins as resist substrates. An example of a negative-type resist using such a low-molecular-weight material as a resist substrate is a resist using calixresorcinarene and its derivatives (Patent Document 1).

[0006] Furthermore, the applicant has disclosed a negative-type resist composition that can obtain a pattern with high linewidth stability after exposure in a vacuum, high resolution, and low line edge roughness, which is a chemically amplified or non-chemically amplified negative-type resist composition containing a phenolic compound (A) with a molecular weight of 400 to 2500, having two or more phenolic hydroxyl groups in one molecule and one or more substituents selected from the group consisting of a hydroxymethyl group and an alkoxymethyl group at the ortho position of the phenolic hydroxyl group in one molecule, wherein the content of the phenolic compound (A) in the total solid content of the negative-type resist composition is 70% by mass or more (Patent Document 2). However, in Patent Document 2, the non-chemically amplified negative resist composition uses only the phenolic compound (A) as the solid component. The basic compound described in Patent Document 2 is merely described as a quencher to suppress the diffusion of acid generated from the acid generator in the chemically amplified negative resist composition. There is no description whatsoever of combining the phenolic compound (A) with the basic compound in the non-chemically amplified negative resist composition without using an acid generator.

[0007] Furthermore, in Patent Document 3, the applicant discloses a resist composition that provides excellent resolution while maintaining the high sensitivity characteristic of chemically amplified resists, comprising a phenolic compound (A), an acid generator (B), and a nitrogen-containing basic compound (B) having one or more aromatic rings per molecule and one or more phenolic hydroxyl groups and / or oxy groups (-O-) per molecule, with a molecular weight of 400 to 3000. However, the basic compound described in Patent Document 3 is merely described as a quencher for suppressing the diffusion of acid generated from an acid generator in a chemically amplified negative resist composition. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 10-239843 [Patent Document 2] Patent No. 5083478 [Patent Document 3] Patent No. 5742413 [Overview of the initiative] [Problems that the invention aims to solve]

[0009] Conventional chemically amplified negative resist compositions have been made highly sensitive by the use of acid generators, but they are not suitable for applications such as grayscale exposure, and there is a need for non-chemically amplified negative resist compositions. Conventional non-chemically amplified negative resist compositions still lack sufficient sensitivity, and there is a need for a non-chemically amplified negative resist composition that can form patterns with high sensitivity and excellent resolution.

[0010] In view of the above circumstances, the object of this disclosure is to provide a non-chemically amplified negative-type resist composition that can be alkaline developed and can form a highly sensitive and high-resolution pattern when patterned by irradiation with an electron beam, ion beam, or EUV, and a method for manufacturing a resist pattern using the negative-type resist composition and a mold. [Means for solving the problem]

[0011] One embodiment of the present disclosure comprises a phenolic compound (A) having a molecular weight of 400 to 2500, having two or more phenolic hydroxyl groups in one molecule, and having two or more substituents selected from the group consisting of hydroxymethyl groups and alkoxymethyl groups at the ortho position of the phenolic hydroxyl groups in one molecule, The present invention provides a negative-type resist composition containing a nitrogen-containing basic compound (B) having one or more aromatic rings per molecule and one or more phenolic hydroxyl groups and / or phenoxy groups per molecule, with a molecular weight of 400 to 3000, wherein the content of the phenolic compound (A) in the total solid content of the negative-type resist composition is 70% by mass or more, and substantially free of acid generators, and is a non-chemically amplified negative-type resist composition.

[0012] In the non-chemically amplified negative resist composition of this disclosure, it is preferable that the nitrogen-containing basic compound (B) is a compound represented by the following formula (I) in order to form a pattern with high sensitivity and excellent resolution.

[0013] [ka] (In formula (I), R a R represents an alkylene group which may have a direct bond or an oxy group (-O-), b and R c Each of these is independently a monovalent organic group which may have an oxy group (-O-), and Ar is a monovalent organic group having an aromatic ring. However, each molecule contains one or more phenolic hydroxyl groups and / or phenoxy groups.

[0014] In the non-chemically amplified negative resist composition of this disclosure, the nitrogen-containing basic compound (B) may be one or more substituents selected from the group consisting of a hydroxymethyl group and an alkoxymethyl group at the ortho position of the phenolic hydroxyl group.

[0015] Other embodiments of the present disclosure include the steps of applying a non-chemically amplified negative resist composition according to the present disclosure onto a substrate, then heat-treating it to form a resist film, and The present invention provides a method for manufacturing a resist pattern, which includes the step of exposing the resist film with an electron beam, ion beam, EUV, or X-ray and developing it.

[0016] Another embodiment of the present disclosure provides a mold having an uneven pattern, wherein at least the protrusions contain a cured product of the non-chemically amplified negative resist composition according to the present disclosure. [Effects of the Invention]

[0017] According to this disclosure, a non-chemically amplified negative-type resist composition that can be alkaline developed and can form highly sensitive and high-resolution patterns when patterned by electron beam, ion beam, or EUV irradiation, and a method for manufacturing a resist pattern using the negative-type resist composition and a mold can be provided. [Brief explanation of the drawing]

[0018] [Figure 1] Figure 1 shows the sensitivity curves of exposure amount and post-development resist film thickness for the non-chemically amplified negative resist compositions of Examples 1-3 and Comparative Example 1. [Figure 2] Figure 2 shows scanning electron microscope images of Example 1 and Comparative Example 1. [Modes for carrying out the invention]

[0019] The embodiments and examples of this disclosure will be described below with reference to the drawings. However, this disclosure can be implemented in many different ways, and should not be interpreted as being limited to the embodiments and examples described below. In addition, the drawings may be schematically represented in terms of width, thickness, shape, etc. of each part compared to the actual embodiment in order to make the explanation clearer, but these are merely examples and should not limit the interpretation of this disclosure. Furthermore, in this specification and each drawing, elements similar to those described above in previously shown drawings will be denoted by the same reference numerals, and detailed explanations may be omitted as appropriate. Also, for the convenience of explanation, the terms "up" or "down" may be used in the explanation, but the up and down directions may be reversed. In this specification, when a component or region is said to be "above (or below)" another component or region, unless otherwise specified, this includes not only cases where it is directly above (or below) the other component, but also cases where it is above (or below) the other component, that is, cases where another component is included between them above (or below) the other component.

[0020] In this disclosure, "active energy rays" means far ultraviolet rays such as KrF excimer lasers, ArF excimer lasers, and F2 excimer lasers, electron beams, ion beams, EUV, X-rays, etc. In the notation of groups (atomic groups) in this disclosure, notations that do not specify substituted or unsubstituted include both those with and without substituents. For example, "alkyl group" includes not only alkyl groups without substituents (unsubstituted alkyl groups) but also alkyl groups with substituents (substituted alkyl groups). The divalent bond of an alkylene group includes not only cases where the bonds originate from different carbon atoms (e.g., -CH2CH2-) but also cases where the bonds originate from the same carbon atom (e.g., -CH2-). Furthermore, alkyl groups and cycloalkyl groups include not only saturated hydrocarbons but also unsaturated hydrocarbons having double bonds, triple bonds, etc. Cycloalkyl groups include not only monocyclic hydrocarbons but also polycyclic hydrocarbons such as bicyclic and tricyclic hydrocarbons. In this disclosure, "phenolic hydroxyl group" means a hydroxyl group directly bonded to an aromatic ring such as benzene, and "phenoxy group" means an oxy group (-O-) directly bonded to an aromatic ring such as benzene. In this disclosure, the phrase "X and / or Y" means "(X), (Y), or (X and Y)." Furthermore, in this disclosure, the "~" symbol indicating a numerical range is used to mean that the numbers written before and after it are included as the lower and upper limits, respectively. The non-chemically amplified negative resist composition, the method for manufacturing the resist pattern, and the mold of this disclosure will be described in detail below.

[0021] I. Non-chemically amplified negative-type resist compositions A non-chemically amplified negative resist composition according to one embodiment of the present disclosure comprises a phenolic compound (A) having two or more phenolic hydroxyl groups in one molecule, and two or more substituents selected from the group consisting of hydroxymethyl groups and alkoxymethyl groups at the ortho position of the phenolic hydroxyl groups in one molecule, and a phenolic compound (A) having a molecular weight of 400 to 2500, A negative-type resist composition containing a nitrogen-containing basic compound (B) having one or more aromatic rings per molecule and one or more phenolic hydroxyl groups and / or phenoxy groups per molecule, with a molecular weight of 400 to 3000, wherein the content of the phenolic compound (A) in the total solid content of the negative-type resist composition is 70% by mass or more, and substantially free of acid generators, and is a non-chemically amplified negative-type resist composition.

[0022] The non-chemically amplified negative resist composition of one embodiment of the present disclosure contains the specific phenolic compound (A) and the specific nitrogen-containing basic compound (B), thereby enabling alkaline development during pattern formation by electron beam, ion beam, or EUV irradiation, and enabling the formation of highly sensitive and high-resolution patterns. The mechanism by which the combination of the specific phenolic compound (A) and the specific nitrogen-containing basic compound (B) produces the above-mentioned effects is not yet fully understood, but it is presumed to be as follows. The aforementioned specific phenolic compound (A) is a relatively low-molecular-weight specific phenolic compound that serves as a resist substrate, to which one or more substituents selected from the group consisting of a hydroxymethyl group and an alkoxymethyl group are introduced as crosslinking groups at the ortho position of the phenolic hydroxyl group. In other words, the aforementioned specific phenolic compound (A) is a resist substrate that also functions as a crosslinking agent. The aforementioned specific phenolic compound (A) has a high ratio of crosslinking groups to hydroxyl groups, and therefore has a high content of the phenolic compound (A) in the total solid content of the resist composition. As a result, the non-chemically amplified resist composition of this disclosure undergoes a crosslinking reaction by the crosslinking groups of the aforementioned specific phenolic compound (A) without the need for acid, upon irradiation with active energy rays. The hydroxymethyl and alkoxymethyl groups introduced as crosslinking groups exhibit excellent chemical stability. However, the inclusion of the specific nitrogen-containing basic compound (B) improves reactivity, allowing the crosslinking reaction to proceed even at lower activity energies, and thus improving sensitivity. The above-mentioned negative-type resist composition is alkali-soluble because it has phenolic hydroxyl groups. However, when exposed to light (irradiated with an electron beam, etc.) during resist pattern formation, crosslinking bonds are formed between the phenolic compounds (A) due to the presence of one or more substituents selected from the group consisting of hydroxymethyl groups and alkoxymethyl groups located at the ortho position of the phenolic hydroxyl groups, making the resist insoluble in alkali. Therefore, when a resist film made of the negative-type resist composition is selectively exposed during resist pattern formation, the exposed areas become alkali-insoluble, while the unexposed areas remain alkali-soluble and unchanged. Thus, a negative-type resist pattern can be formed by alkali development. Furthermore, the non-chemically amplified negative resist composition of this disclosure uses the specific phenolic compound (A), which is relatively low molecular weight, in a state where the solid content of the resist composition is high, and the specific nitrogen-containing basic compound (B) has a structure that is highly compatible with the specific phenolic compound (A). As a result, the uniformity of the resist composition in the coating film is good, and since acid diffusion is not utilized during image formation, it is presumed to have excellent resolution.

[0023] The components of the negative-type resist composition of this disclosure will be described in detail below. <Phenolic compound (A)> The phenolic compound (A) used in this disclosure is a compound with a molecular weight of 400 to 2500, having two or more phenolic hydroxyl groups in one molecule, and having two or more substituents selected from the group consisting of hydroxymethyl groups and alkoxymethyl groups at the ortho position of the phenolic hydroxyl groups in one molecule. By setting the molecular weight of the phenolic compound (A) within the above range, excellent resolution can be obtained.

[0024] The phenolic compound (A) used in this disclosure only needs to have two or more phenolic hydroxyl groups in one molecule, and the number of phenolic hydroxyl groups in one molecule is not particularly limited. The phenolic compound (A) used in this disclosure is preferably appropriately selected to have alkali solubility based on the following criteria. The phenolic compound (A) is preferably selected and used if its development rate in a 25% by mass aqueous solution of tetramethylammonium hydroxide (TMAH) (23°C) is 0.5 nm / sec or higher, and more preferably if it is 1.0 nm / sec or higher. By keeping the alkaline development rate of the alkali-soluble resin within the above range, the pattern shape can be improved.

[0025] For example, the development rate for a 25% by mass aqueous solution of tetramethylammonium hydroxide (TMAH) (23°C) can be calculated by, for example, using the above-mentioned phenolic compound (A) alone to make a 5% by mass solution, forming a coating film on a silicon wafer so that the film thickness after drying is 300 nm, then immersing it in a 25% by mass aqueous solution of tetramethylammonium hydroxide (TMAH) (23°C), and measuring the time until the coating film is completely dissolved.

[0026] The phenolic compound (A) used in this disclosure only needs to have two or more substituents selected from the group consisting of a hydroxymethyl group and an alkoxymethyl group at the ortho position of the phenolic hydroxyl group in one molecule. One or more substituents selected from the group consisting of a hydroxymethyl group and an alkoxymethyl group at the ortho position of the phenolic hydroxyl group function as a crosslinking group for the phenolic compound. The phenolic compound (A) used in this disclosure is preferable to have three or more substituents selected from the group consisting of a hydroxymethyl group and an alkoxymethyl group at the ortho position of the phenolic hydroxyl group in one molecule, and more preferably four or more in one molecule, from the viewpoint of increasing crosslinkability.

[0027] Preferably, the alkoxymethyl group has 1 to 6 carbon atoms, and specifically, examples include methoxymethyl group, ethoxymethyl group, n-propoxymethyl group, isopropoxymethyl group, n-butoxymethyl group, sec-butoxymethyl group, t-butoxymethyl group, and various pentyloxymethyl groups. Among the alkoxymethyl groups, methoxymethyl group and ethoxymethyl group are preferred because they provide good sensitivity.

[0028] Among the crosslinking groups, it is preferable that one or more substituents selected from the group consisting of hydroxymethyl, methoxymethyl, and ethoxymethyl groups be positioned at the ortho position of the phenolic hydroxyl group, as this results in high reactivity and good sensitivity.

[0029] The phenolic compound (A) used in this disclosure is selected from compounds with a molecular weight of 400 to 2500. If the molecular weight is below the lower limit, the ability to form a resist film and a pattern may be reduced. On the other hand, if the molecular weight exceeds the upper limit, it may swell easily due to the solvent used in the resist composition, making it prone to pattern collapse and potentially resulting in a poor pattern shape. Here, molecular weight refers to the sum of the atomic weights of the atoms constituting the molecule. Furthermore, if it is an oligomer with a molecular weight distribution, it is expressed as the mass-average molecular weight using GPC (polystyrene equivalent). The molecular weight of the phenolic compound (A) used in this disclosure is preferably 500 to 2500, and more preferably 600 to 2000, from the viewpoint of film-forming properties and resolution.

[0030] The phenolic compound (A) used in this disclosure preferably has a glass transition temperature (Tg) of 60°C or higher, and more preferably 90°C or higher. A glass transition temperature of 60°C or higher makes dewetting less likely to occur when forming a coating film, making it easier to obtain a uniform film. Dewetting refers to the phenomenon in which the spread coating film dissolves during pre-baking, causing repulsion and preventing the formation of a uniform film. Typically, when using solvents for resist compositions, solvents with a boiling point of 90-180°C are used to obtain a uniform resist film when applied by methods such as spin coating, because using low-boiling-point solvents causes the resist film to dry rapidly, resulting in an uneven film. Since resist films formed by spin coating contain a large amount of residual solvent, the resist substrate is heated to a temperature of 90°C or higher on a hot plate (pre-baking) to remove this solvent and form a stable resist film. However, if phenolic compounds with a glass transition temperature of less than 60°C are used, dewetting of the resist film may occur during the pre-baking process, potentially resulting in an uneven film. In contrast, when using phenolic compounds with a glass transition temperature of 60°C or higher, pre-baking at high temperatures becomes possible, resulting in a uniform film and a resist film with excellent environmental resistance (post-coating delay: PCD). Furthermore, it is possible to suppress the density dependence of the pattern that occurs during electron beam pattern formation. In addition, in the dry etching process after resist pattern formation, a pattern with excellent etching resistance (prevention of pattern melting due to high temperatures during etching) can be obtained. The glass transition temperature in this case was measured using a differential scanning calorimeter (DSC).

[0031] Furthermore, the phenolic compound (A) used in this disclosure preferably has a solubility of 5% by mass or more at 23°C in an organic solvent with a boiling point of 80 to 180°C. In such cases, it is possible to prevent rapid drying of the resist film during spin coating, which has the advantage of obtaining a uniform resist film. Typical examples of organic solvents with a boiling point of 80 to 180°C include cyclopentanone, propylene glycol monomethyl ether, cyclohexanone, propylene glycol monomethyl ether acetate, ethyl lactate, 2-heptanone, diethylene glycol dimethyl ether, and 1-ethoxy-2-propanol.

[0032] In particular, the phenolic compound (A) used in this disclosure preferably has a glass transition temperature (Tg) of 60°C or higher and is soluble in an organic solvent with a boiling point of 80 to 180°C at 23°C in an amount of 5% by mass or more.

[0033] The phenolic compound (A) is not particularly limited and can be selected and used as appropriate. For example, the compounds represented by the following chemical formulas (1) and (3) can be cited.

[0034] [ka] [In chemical formula (1), R 1 Each of these is independently selected from the group consisting of a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, and the group shown in the following chemical formula (2), R 1 The aryl group contained in may contain one or more substituents selected from the group consisting of hydroxyl groups, hydroxymethyl groups, and alkoxymethyl groups.

[0035] [ka] (In chemical formula (2), R 4 and R 5each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, Q represents an aryl group or a cycloalkyl group, and m represents 1 or 2.) R 2 each independently represents a hydrogen atom or a monovalent organic group, and among a plurality of R 2 at least two groups per molecule are hydrogen atoms. R 3 is a group selected from the group consisting of a halogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, an acyl group, a cyano group, a nitro group, a hydroxymethyl group, and an alkoxymethyl group. n1 represents an integer of 1 to 3, n2 represents an integer of 0 to 2; provided that a combination satisfying n1+n2≦4 is selected from the numerical ranges of n1 and n2. x1 represents an integer of 3 to 12. provided that in R 1 and / or R 3 the compound has one or more substituents selected from the group consisting of a hydroxymethyl group and an alkoxymethyl group at the ortho position of a phenolic hydroxyl group, in an amount of one or more substituents per molecule. Furthermore, groups represented by the same symbol included in chemical formula (1) may be the same as or different from each other.]]

[0036]

Chemical

[0037] In the compound represented by the above chemical formula (1), R 1 There are no particular restrictions on the alkyl group, but alkyl groups having 1 to 18 carbon atoms are preferred. The alkyl group may be linear or branched. Examples include methyl group, ethyl group, n-propyl group, n-butyl group, i-propyl group, i-butyl group, t-butyl group, i-pentyl group, t-pentyl group, hexadecyl group, etc. It may also have unsaturated bonds such as double bonds and triple bonds.

[0038] Examples of substituents on an alkyl group include hydroxyl groups, alkoxy groups, halogen atoms, and halogenoalkyl groups.

[0039] R 1 There are no particular restrictions on the cycloalkyl group, and examples include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl groups. Furthermore, it may have unsaturated bonds such as double or triple bonds, and may be monocyclic or polycyclic. A cyclohexyl group is preferred as the cycloalkyl group.

[0040] There are no particular restrictions on the substituents that a cycloalkyl group may have, but examples include alkyl groups having 1 to 5 carbon atoms, hydroxyl groups, alkoxy groups, alkoxyalkyl groups, halogen atoms, and halogenoalkyl groups.

[0041] The alkyl group having 1 to 5 carbon atoms may be either linear or branched. Examples of linear alkyl groups include methyl, ethyl, n-propyl, and n-butyl groups. Examples of branched alkyl groups include i-propyl, i-butyl, t-butyl, i-pentyl, and t-pentyl groups.

[0042] Furthermore, there are no particular restrictions on the alkoxy group, but alkoxy groups having 1 to 8 carbon atoms are preferred, such as methoxy, ethoxy, propoxy, butoxy, and 2-ethylhexyloxy groups.

[0043] There are no particular restrictions on the alkoxyalkyl group, but alkoxyalkyl groups having 1 to 8 carbon atoms are preferred, such as methoxymethyl group, ethoxymethyl group, methoxyethyl group, ethoxyethyl group, and methoxypropyl group.

[0044] Examples of halogen atoms include fluorine, chlorine, bromine, and iodine.

[0045] There are no particular restrictions on the halogenoalkyl group, but halogenoalkyl groups having 1 to 8 carbon atoms are preferred. Examples include chloromethyl group, dichloromethyl group, trichloromethyl group, bromomethyl group, dibromomethyl group, tribromomethyl group, fluoromethyl group, difluoromethyl group, trifluoromethyl group, 1-chloroethyl group, 1-bromoethyl group, 1-fluoroethyl group, 1,2-dichloroethyl group, and 1,1,2,2-tetrachloroethyl group.

[0046] R 1 There are no particular restrictions on the aryl group, but it is preferably having 6 to 14 carbon atoms, and more preferably 6 to 10 carbon atoms. Examples include a phenyl group, a naphthyl group, and anthryl group.

[0047] Furthermore, examples of substituents on the aryl group include hydroxymethyl groups, alkoxymethyl groups, cycloalkyl groups, C1-C5 alkyl groups, hydroxyl groups, alkoxy groups, alkoxyalkyl groups, halogen atoms, and halogenoalkyl groups. Examples of cycloalkyl groups as substituents on the aryl group are the same as those described above. Furthermore, the cycloalkyl group may have substituents, such as C1-C5 alkyl groups, halogen atoms, cyano groups, hydroxyl groups, and alkoxy groups. Examples of C1-C5 alkyl groups include methyl groups, ethyl groups, and i-propyl groups. There are no particular restrictions on the alkoxy group, but C1-C8 alkoxy groups are preferred, such as methoxy groups, ethoxy groups, propoxy groups, butoxy groups, and 2-ethylhexyloxy groups. The substituents on the aryl group are C1-C5 alkyl groups, alkoxy groups, alkoxyalkyl groups, halogen atoms, halogenoalkyl groups, and alkoxymethyl groups, as shown above.

[0048] In the above chemical formula (2), R 4 and R 5Each of these is independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. The alkyl group having 1 to 3 carbon atoms may be linear or branched, but among them, methyl and ethyl groups are preferred from the viewpoint of etching resistance. When m is 2, there are two R 4 and R 5 These may be the same or different. In the above chemical formula (2), R 4 and R 5 In cases where both are hydrogen atoms, this is preferably used.

[0049] The aryl group Q in the above chemical formula (2) can be the same as the aryl group described above. The substituents on the aryl group Q can be the same as the substituents on the aryl group described above, and may include one or more substituents selected from the group consisting of hydroxyl groups, hydroxymethyl groups, and alkoxymethyl groups. Furthermore, the cycloalkyl group Q in the above chemical formula (2) can be the same as the cycloalkyl group described above. The substituents on the cycloalkyl group Q can be the same as the substituents on the cycloalkyl group described above.

[0050] R 2 There are no particular restrictions on the monovalent organic group, but examples include alkyl groups, cycloalkyl groups, and aryl groups. R 2 The alkyl group is the above R 1 Similar examples include R. 2 The substituents on the alkyl group are the above R 1 Examples similar to the above include: Also, R 2 The cycloalkyl group and the substituents of the cycloalkyl group are as follows: 1 It can be made to be similar to that of R. 2 The aryl group and the substituents on the aryl group are as follows: 1 It can be made to be similar to that of the other.

[0051] R 3 The alkoxymethyl group is as shown above. R 3 The halogen atom and alkyl group are as follows: 1 Similar examples include the above. R 3 Substituents that alkyl groups can have include cycloalkyl groups, aryl groups, amino groups, amide groups, ureido groups, urethane groups, hydroxyl groups, carboxyl groups, halogen atoms, alkoxy groups, thioether groups, acyl groups, acyloxy groups, alkoxycarbonyl groups, cyano groups, nitro groups, and the like.

[0052] R 3 The cycloalkyl group and the substituents of the cycloalkyl group are as follows: 1 It can be made to be similar to the one. 3 The aryl group and the substituents on the aryl group are as follows: 1 It can be made to be similar to that of the other. Also, R 3 The alkoxy group is the above R 1 Similar examples include the above.

[0053] R 3 There are no particular restrictions on the acyl group, but acyl groups having 1 to 8 carbon atoms are preferred, such as formyl, acetyl, propionyl, butyryl, valeryl, pivaloyl, and benzoyl groups.

[0054] x1 is an integer between 3 and 12, preferably between 4 and 12, and more preferably between 4 and 8.

[0055] The compound represented by the chemical formula (1) has two or more phenolic hydroxyl groups in one molecule, and one or more substituents selected from the group consisting of hydroxymethyl groups and alkoxymethyl groups at the ortho position of the phenolic hydroxyl groups, and the substituents indicated by the same sign in each repeating unit may be the same or different. OR in each repeating unit 2 and R 3 The positions can be the same or different.

[0056] In the compound represented by the above chemical formula (1), in order to obtain a pattern with high sensitivity, high resolution and good shape, it is preferable that x1 is 4 and n1 is 2, and moreover, that there are 8 R with x1 4 and n1 2. 2 Among them, a calixresorcinarene derivative having 4 to 8 hydrogen atoms, and R 2 It is preferable that the molecule has one or more substituents selected from the group consisting of a hydroxymethyl group and an alkoxymethyl group at the ortho position where the atom is a hydrogen atom. Furthermore, in the compound represented by the above chemical formula (1), in order to obtain a pattern with high sensitivity, high resolution and good shape, it is preferable that x1 is 4 and n1 is 2, and moreover, that there are 8 R with x1 4 and n1 2. 2 Among them, a calixresorcinarene derivative having 0 to 8 hydrogen atoms, and R 1 Preferably, the aryl group has a phenolic hydroxyl group and one or more substituents selected from the group consisting of a hydroxymethyl group and an alkoxymethyl group at the ortho position of the phenolic hydroxyl group.

[0057] On the other hand, in the compound represented by the above chemical formula (3), R 6 , R 7 , R 8 and R 9 The alkyl group in this compound may be linear or branched, and preferably has 1 to 10 carbon atoms, such as a methyl group, ethyl group, propyl group, butyl group, isobutyl group, hexyl group, or octyl group. R 6 , R 7 , R 8 and R 9The cycloalkyl group in this formula may be monocyclic or polycyclic. Examples include groups having monocyclo, bicyclo, tricyclo, or tetracyclo structures with 5 or more carbon atoms. The number of carbon atoms is preferably 6 to 30, and particularly preferably 7 to 25. Examples include adamantyl, noradamantyl, decalin, tricyclodecanyl, tetracyclododecanyl, norbornyl, cedrol, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecanyl, and cyclododecanyl groups. These alicyclic hydrocarbon groups may have substituents. R 6 , R 7 , R 8 and R 9 The aryl group in the above R is 1 It can be the same as that. Also, R 6 , R 7 , R 8 and R 9 The hydroxymethyl group or alkoxymethyl group in this may be the same as described above. Furthermore, in the compound represented by the above chemical formula (3), R 6 If (x2) is an integer greater than or equal to 2, then it becomes the basis for the (x2) value. 6 If (x2) is an integer of 2 or more, then may be a (x2)-valent aliphatic hydrocarbon group, a (x2)-valent cyclic aliphatic hydrocarbon group, a (x2)-valent aromatic hydrocarbon group, or a group consisting of a combination thereof, for example, R 6 When (x2) is 2, it may be an alkylene group, a cycloalkylene group, an arylene group, or a group consisting of a combination thereof.

[0058] Examples of substituents that the alkyl group, cycloalkyl group, or aryl group may have include hydroxyl groups, carboxyl groups, halogen atoms (fluorine, chlorine, bromine, or iodine atoms), alkoxy groups (such as methoxy, ethoxy, propoxy, or butoxy groups), hydroxymethyl groups, or alkoxymethyl groups.

[0059] R 10 and R11 Examples of the monovalent organic group include an alkyl group, an aryl group, an aralkyl group, an alkoxy group, an alkoxycarbonyl group, an amido group, a cyano group, and the like. The alkyl group is preferably an alkyl group having 1 to 10 carbon atoms or a cycloalkyl group, and examples thereof include a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a hexyl group, a 2-ethylhexyl group, an octyl group, a cyclopropyl group, a cyclobutyl group, a cyclohexyl group, an adamantyl group, and the like. The aryl group is preferably an aryl group having 6 to 14 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, an anthracenyl group, and the like. The aralkyl group is preferably an aralkyl group having 6 to 12 carbon atoms, and examples thereof include a benzyl group, a phenethyl group, a cumyl group, and the like. The alkoxy group in the alkoxy group and the alkoxycarbonyl group is preferably an alkoxy group having 1 to 5 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, a propoxy group, an n-butoxy group, an isobutoxy group, and the like.

[0060] The alkylene group for W may be linear or branched, and preferably has 1 to 10 carbon atoms. Examples thereof include a methylene group, an ethylene group, a propylene group, a butylene group, an isobutylene group, and the like. The cycloalkylene group for W may be either monocyclic or polycyclic. Examples of the cycloalkylene group forming the ring include a cycloalkylene group having 3 to 8 carbon atoms (e.g., a cyclopentylene group, a cyclohexylene group). The alkylene group and the cycloalkylene group for W may further have a substituent. Examples of the substituent include an alkyl group (preferably having 1 to 10 carbon atoms, e.g., a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a t-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, etc.), an alkoxy group (preferably having 1 to 4 carbon atoms, e.g., a methoxy group, an ethoxy group, a propoxy group, a butoxy group, etc.), a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like.

[0061] Furthermore, the alkylene chain or cycloalkylene chain may contain -O-, -OC(=O)-, -OC(=O)O-, -N(R)-C(=O)-, -N(R)-C(=O)O-, -S-, -SO-, and -SO2- in the alkylene chain. Here, R is a hydrogen atom or an alkyl group (preferably having 1 to 10 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a t-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, etc.). The cyclic arylene group in W is preferably a phenylene group, a torylene group, a naphthylene group, or other group having 6 to 15 carbon atoms.

[0062] Specific examples of phenolic compounds (A) are shown below, but the disclosure is not limited to these. If a molecule contains two or more phenolic hydroxyl groups, and each molecule has two or more substituents selected from the group consisting of hydroxymethyl groups and alkoxymethyl groups at the ortho position of the phenolic hydroxyl groups, the phenolic hydroxyl groups in the following specific examples may be protected by organic groups. Furthermore, in the following formula, L is independently one or more substituents selected from the group consisting of a hydrogen atom, a hydroxymethyl group, and an alkoxymethyl group, and at least two Ls in one molecule are one or more substituents selected from the group consisting of a hydroxymethyl group and an alkoxymethyl group located at the ortho position of a phenolic hydroxyl group. In addition, the molecular weight shall satisfy the range of 400 to 2500.

[0063] [ka]

[0064] [ka]

[0065] [ka]

[0066] [ka]

[0067] [ka]

[0068] The phenolic compound (A) used in this disclosure can be obtained by introducing one or more substituents selected from the group consisting of a hydroxymethyl group and an alkoxymethyl group to the ortho position of the phenolic hydroxyl group in the core compound of the phenolic compound. As a method for introducing the substituent that functions as a crosslinking group into the core compound of the phenolic compound, for example, it can be obtained by reacting a phenol compound that does not have the corresponding hydroxymethyl group with formaldehyde under a base catalyst. In this case, it is preferable to carry out the reaction at a temperature of 50°C or lower in order to prevent side reactions such as gelation. Furthermore, various bisphenol derivatives having an alkoxymethyl group can be obtained by reacting a bisphenol derivative having the corresponding hydroxymethyl group with an alcohol under an acid catalyst. In this case, it is preferable to carry out the reaction at a temperature of 100°C or lower in order to prevent side reactions such as gelation.

[0069] The parent compound of the aforementioned phenolic compound (A) is commercially available from companies such as Honshu Chemical Industry Co., Ltd. and Asahi Organic Chemicals Industry Co., Ltd., and can be used. Alternatively, it can be synthesized by condensation of various phenolic compounds with various aldehydes and ketones.

[0070] In the negative resist composition according to this disclosure, the phenolic compound (A) may be one of the above-mentioned compounds used alone, or two or more may be used as a mixture. However, in the negative resist composition according to this disclosure, it is preferable that the phenolic compound (A) has a purity of 70% by mass or more of a compound with the same structural formula, in order to form a good pattern. It is even more preferable that the phenolic compound (A) has a purity of 80% by mass or more of a compound with the same structural formula, and even more preferable that it has a purity of 90% by mass or more. It is presumed that using a highly pure compound with the same structural formula as the phenolic compound (A) will result in a more uniform development process. However, even if the purity of a compound with the same structural formula as phenolic compound (A) is less than the above value, it can be suitably used if the structure of the impurity is similar to that of phenolic compound (A) and it has good compatibility.

[0071] The phenolic compounds used in this disclosure are preferably those that do not have a molecular weight distribution. Even if the phenolic compounds used in this disclosure have a molecular weight distribution, those with a small molecular weight distribution are preferred. <mw>and number-average molecular weight ratio <mw> / It is preferable that the value is between 1.0 and 1.1.

[0072] The content of the phenolic compound (A) is 70% by mass or more, preferably 80% by mass or more, and more preferably 90% by mass or more, based on the total solid content of the resist composition. The content of the phenolic compound (A) may be 95% by mass or more, 98% by mass or more, 99% by mass or more, 99.1% by mass or more, based on the total solid content of the resist composition, while it may be 99.9% by mass or less, or 99.1% by mass or less. In this disclosure, "solid content" refers to components other than organic solvents that are included in the negative-type resist composition.

[0073] <Nitrogen-containing basic compound (B)> The nitrogen-containing basic compound (B) used in the present invention is an organic basic compound having a molecular weight of 400 to 3000, having one or more aromatic rings and one or more phenolic hydroxyl groups and / or phenoxy groups per molecule. When the nitrogen-containing basic compound (B) is used in combination with the phenolic compound (A), sensitivity can be improved.

[0074] The aromatic ring in nitrogen-containing basic compound (B) is not particularly limited. For example, aromatic hydrocarbons such as benzene, naphthalene, and anthracene, as well as heteroaromatic rings such as pyridine, pyrrole, and thiophene, are examples. Among these, from the viewpoint of compatibility with the phenolic compound (A), the aromatic ring is preferably an aromatic hydrocarbon, and more preferably benzene. The aforementioned aromatic ring may be present in one or more molecules of the nitrogen-containing basic compound (B). In particular, it is preferable to have two or more aromatic rings per molecule of the nitrogen-containing basic compound (B), and more preferably three or more aromatic rings per molecule, as this improves compatibility with the phenolic compound (A) and suppresses non-uniform distribution in the resist coating film.

[0075] In nitrogen-containing basic compounds (B), the phenoxy group (Ar-O-, where Ar represents the aromatic ring) may be included as an ester bond (Ar-OCO-) or a carbonate bond (Ar-O-COO-), as long as the oxygen of the oxy group is directly bonded to the aromatic ring.

[0076] The nitrogen-containing basic compound (B) used in the present invention may have one or more phenolic hydroxyl groups and / or phenoxy groups per molecule. That is, the nitrogen-containing basic compound (B) used in the present invention may have one or more phenolic hydroxyl groups, phenoxy groups, or phenolic hydroxyl groups and phenoxy groups per molecule. In particular, from the viewpoint of improving compatibility with the phenolic compound (A), it is preferable that the nitrogen-containing basic compound (B) has two or more phenolic hydroxyl groups and / or phenoxy groups per molecule, and more preferable that it has three or more phenolic hydroxyl groups and / or phenoxy groups per molecule.

[0077] The molecular weight of the nitrogen-containing basic compound (B) used in the present invention is 400 to 3000. By having a molecular weight of 400 to 3000, the resist composition using the nitrogen-containing basic compound (B) can achieve high sensitivity while exhibiting excellent resolution. From the viewpoint of resolution, the molecular weight of the nitrogen-containing basic compound (B) is more preferably 2000 or less, and even more preferably 1000 or less.

[0078] In the present invention, it is preferable that the nitrogen-containing basic compound (B) is a compound represented by the following formula (I) from the viewpoint of improving sensitivity and resolution.

[0079] [ka] (In formula (I), R a R represents an alkylene group which may have a direct bond or an oxy group (-O-), b and R c each independently represents a monovalent organic group that may optionally have an oxy group (-O-); Ar represents a monovalent organic group having an aromatic ring, provided that one molecule has one or more phenolic hydroxyl groups and / or phenoxy groups (-O-).)

[0080] R a The alkylene group is not particularly limited, and may be linear or branched. Among these, alkylene groups having 1 to 10 carbon atoms are preferable, and examples thereof include a methylene group, an ethylene group, a propylene group, a butylene group, and an isobutylene group. Further, the alkylene group may have an oxy group (-O-) in the carbon chain constituting the alkylene group or at the terminal of the carbon chain.

[0081] R b and R c Examples of the monovalent organic group include saturated or unsaturated alkyl groups, saturated or unsaturated cycloalkyl groups, aryl groups, and combinations thereof (such as aralkyl groups and alkylaryl groups). These organic groups may contain bonds or substituents other than hydrocarbon groups such as heteroatoms including an oxy group (-O-) in the organic group, and may be linear or branched. Further, R b and R c may be bonded to each other to form a cyclic structure. The cyclic structure may be a structure formed by combining two or more selected from the group consisting of saturated or unsaturated alicyclic hydrocarbons, heterocycles, condensed rings, and combinations of two or more selected from the aforementioned alicyclic hydrocarbons, heterocycles, and condensed rings.

[0082] The alkyl group is preferably an alkyl group or cycloalkyl group having 1 to 10 carbon atoms, such as methyl, ethyl, propyl, n-butyl, sec-butyl, hexyl, 2-ethylhexyl, octyl, cyclopropyl, cyclobutyl, cyclohexyl, and adamantyl groups. The aryl group is preferably an aryl group having 6 to 14 carbon atoms, such as phenyl, naphthyl, biphenyl, and anthracenyl groups. The aralkyl group is preferably an aralkyl group having 7 to 12 carbon atoms, such as benzyl, phenethyl, and cumyl groups. The alkylaryl group is preferably an alkylaryl group having 7 to 20 carbon atoms, such as various alkylphenyl groups and various alkylnaphthyl groups. Examples of bonds other than hydrocarbon groups in organic groups include ether bonds, thioether bonds, carbonyl bonds, thiocarbonyl bonds, ester bonds, amide bonds, urethane bonds, imino bonds (-N=C(-R)-, -C(=NR)-, where R is a hydrogen atom or a monovalent organic group), and carbonate bonds. Substituents other than hydrocarbon groups in the organic group are not particularly limited and include halogen atoms, hydroxyl groups, mercapto groups, cyano groups, silyl groups, alkoxy groups, nitro groups, acyl groups, acyloxy groups, amino groups, etc. If an aryl group or aralkyl group is present, it is preferable that a hydroxyl group is further present.

[0083] R b and R c As for monovalent organic groups in R, b and / or R c It is preferable that R is an aralkyl group, b is an aralkyl group, R c This may be a monovalent organic group that may have an oxy group (-O-).

[0084] Ar is not particularly limited to a monovalent organic group having an aromatic ring; it may be the aromatic ring itself, or an aromatic ring with further substituents, or a combination of an aromatic ring with a saturated or unsaturated alkyl group or a saturated or unsaturated cycloalkyl group. Examples of aromatic rings with further substituents include those having an alkyl group, alkoxy group, alkoxycarbonyl group, cyano group, hydroxyl group, etc., as functional groups, with those having a hydroxyl group being preferred. The combination of an aromatic ring with a saturated or unsaturated alkyl group or a saturated or unsaturated cycloalkyl group is preferably a phenolic compound, and examples of various carbon skeletons include a residue obtained by removing a hydrogen atom from one phenolic hydroxyl group in a phenolic compound where all L atoms in chemical formulas (a-1) to (a-53) listed as examples of phenolic compound (A) are hydrogen atoms. Examples of the aromatic ring include aromatic hydrocarbons such as benzene, naphthalene, and anthracene, as well as heteroaromatic rings such as pyridine, pyrrole, and thiophene. Among these, from the viewpoint of compatibility with the phenolic compound (A), the aromatic ring is preferably an aromatic hydrocarbon, and more preferably benzene.

[0085] In the present invention, it is preferable that the nitrogen-containing basic compound (B) used in combination with the phenolic compound (A) has the same carbon skeleton, as this improves compatibility and resolution. Here, the same carbon skeleton as the phenolic compound refers to the portion of the phenolic compound excluding the substituents. Furthermore, the nitrogen-containing basic compound (B) of the present invention is preferably a compound obtained by reacting a nitrogen-containing basic compound with a phenolic compound, such as a compound obtained by reacting a tertiary amine having an alkyl halogenate with a phenolic compound, from the viewpoint of compatibility with phenolic compounds.

[0086] The nitrogen-containing basic compound (B) used in the present invention may have one or more substituents selected from the group consisting of a hydroxymethyl group and an alkoxymethyl group at the ortho position of the phenolic hydroxyl group, but may not have one or more substituents selected from the group consisting of a hydroxymethyl group and an alkoxymethyl group at the ortho position of the phenolic hydroxyl group. This is because sensitivity can be improved even without these crosslinking groups.

[0087] The following are specific examples of nitrogen-containing basic compounds (B) used in the present invention, but the present invention is not limited to these.

[0088] [ka]

[0089] [ka]

[0090] [ka]

[0091] [ka]

[0092] [ka]

[0093] These nitrogen-containing basic compounds (B) can be used individually or in combination of two or more. The content of the nitrogen-containing basic compound (B) can be appropriately selected to improve sensitivity, but is preferably 0.01 to 10 parts by mass, and more preferably 0.1 to 5 parts by mass, per 100 parts by mass of the phenolic compound (A). If it is less than 0.01 parts by mass, the effect of the addition may not be obtained, on the other hand, if it exceeds 10 parts by mass, the developability of the unexposed areas may deteriorate. The content of the nitrogen-containing basic compound (B) may be 0.01% by mass or more, 0.09% by mass or more, 10% by mass or less, 9.1% by mass or less, or 5% by mass or less, based on the total solid content of the resist composition.

[0094] <Other ingredients> The non-chemically amplified negative resist composition of this disclosure is substantially free of acid generators because it is non-chemically amplified. Here, "substantially free" means that it is free to the extent that it functions substantially as a chemically amplified resist. In the case of a non-chemically amplified resist composition, the content of the photoacid generator is less than 1 part by mass per 100 parts by mass of phenolic compound (A), and may be 0 parts by mass. As a guideline, it is less than 2% by mass of the total solid content of the resist composition, and may be 0% by mass.

[0095] The non-chemically amplified negative resist composition of this disclosure does not need to contain a phenolic compound that does not have a hydroxymethyl group or an alkoxymethyl group, because it uses the specific phenolic compound (A) described above. Phenolic compounds that do not fall under the phenolic compound (A) of this application, such as phenolic compounds that do not have a hydroxymethyl group or an alkoxymethyl group, may be included to the extent that they do not impair the effects of this disclosure, but it is preferable that they are not included from the viewpoint of low line edge roughness.

[0096] Furthermore, since the non-chemically amplified negative resist composition of this disclosure uses the above-mentioned specific phenolic compound (A), it is not necessary to include a crosslinking agent as has been used conventionally. However, a small amount of crosslinking agent may be added to improve the resist sensitivity, provided that the effects of this disclosure are not impaired. The content of such crosslinking agent can be approximately 10% by mass or less, more preferably 5% by mass or less, relative to the total solid content of the resist composition.

[0097] The crosslinking agent that does not fall under the above-mentioned specific phenolic compound (A) is not particularly limited and can be arbitrarily selected from known crosslinking agents used in conventional chemically amplified negative resist compositions. Examples include 4,4'-methylenebis[2,6-bis(hydroxymethyl)]phenol (MBHP), 4,4'-methylenebis[2,6-bis(methoxymethyl)]phenol (MBMP), 2,3-dihydroxy-5-hydroxymethylnorbornane, 2-hydroxy-5,6-bis(hydroxymethyl)norbornane, cyclohexanedimethanol, 3,4,8 (or 9)-trihydroxytricyclodecane, 2-methyl-2-adamantanol, 1,4-dioxane-2,3-diol, 1,3,5-trihydroxycyclohexane, and other aliphatic cyclic hydrocarbons having a hydroxyl group or a hydroxyalkyl group or both, or their oxygen-containing derivatives. Furthermore, melamine-based crosslinking agents, urea-based crosslinking agents, alkylene urea-based crosslinking agents, and glycoluryl-based crosslinking agents may also be used.

[0098] Furthermore, the non-chemically amplified negative resist composition of this disclosure may contain oligomers or polymer components to improve the performance of the resist film, to the extent that the effects of this disclosure are not impaired. By adding oligomers or polymer components, a network structure can be introduced into the resist film, which may improve resolution through improved pattern strength and improve pattern shape (line edge roughness). The content of such oligomers or polymer components is preferably 5% by mass or less, more preferably 3% by mass or less, based on the total solid content of the resist composition. Examples of oligomer or polymer components include novolac resins, polyhydroxystyrene derivatives, and acrylic copolymers derived from acrylic acid or methacrylic acid, which are alkali-developable resins conventionally used in negative resist compositions for i-line, KrF, and ArF. These oligomer or polymer components may also have reactive functional groups. The mass-average molecular weight of the oligomer or polymer component is preferably 2,000 to 30,000, and more preferably 2,000 to 20,000. Here, the mass-average molecular weight refers to the polystyrene equivalent value measured by GPC (gel permeation chromatography).

[0099] The negative-type resist composition of this disclosure may optionally contain further miscible additives, such as additional resins to improve the performance of the resist film, surfactants to improve coatability, dissolution inhibitors, plasticizers, stabilizers, colorants, and anti-halation agents, as long as they do not impair the effects of this disclosure. The non-chemically amplified negative resist composition of this disclosure may have a total content of the specific phenolic compound (A) and the nitrogen-containing basic compound (B) of 90% by mass or more, 95% by mass or more, 97% by mass or more, or 100% by mass, based on the total solid content of the resist composition.

[0100] <Preparation of Non-Chemically Amplified Negative Resist Compositions> The non-chemically amplified negative resist composition according to this disclosure is typically prepared by uniformly mixing the specific phenolic compound (A), the nitrogen-containing basic compound (B), and other additives as needed in an organic solvent.

[0101] As organic solvents, those commonly used as solvents for resists can be used. For example, ethylene dichloride, cyclohexanone, cyclopentanone, 2-heptanone, γ-butyrolactone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether propionate, diethylene glycol dimethyl ether, toluene, ethyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, N,N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran, etc. are preferred, and these solvents can be used individually or in combination. Furthermore, it may contain alcohols such as isopropyl alcohol, ethyl alcohol, methyl alcohol, n-butyl alcohol, s-butyl alcohol, t-butyl alcohol, isobutyl alcohol, 2-methyl-1-pentanol, 4-methyl-2-pentanol, 2-methoxyethanol, 2-ethoxyethanol, 1-ethoxy-2-propanol, and 1-methoxy-2-propanol, as well as aromatic solvents such as toluene and xylene. In this disclosure, among these organic solvents, diethylene glycol dimethyl ether, cyclohexanone, cyclopentanone, 1-ethoxy-2-propanol, ethyl lactate, and safe solvents such as propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and mixed solvents thereof are preferably used. The amount of solvent in the resist component is not particularly limited and is set appropriately according to the coating thickness, at a concentration that allows it to be applied to a substrate or the like. Generally, the solvent is used so that the solid content concentration of the resist composition is preferably in the range of 0.5 to 20% by mass, more preferably 0.5 to 15% by mass.

[0102] The non-chemically amplified negative resist composition according to this disclosure preferably has a moisture content of 0.5% by mass or less, more preferably 0.01 to 0.5% by mass, and even more preferably 0.15 to 0.30% by mass. The moisture content can be adjusted, for example, by appropriately drying the materials used or by drying the preparation atmosphere (for example, humidity of 50% or less).

[0103] Furthermore, the non-chemically amplified negative resist composition relating to this disclosure has an acid component content of 1 × 10⁻⁶ -3 milliequivalent / g or less, and further 5 x 10 -4 It is preferable to adjust the acid content to milliequivalents / g or less. The acid content can be adjusted, for example, by treating the solution of the material or composition solution used with an ion exchange resin, or by washing the solution of the material used with pure water. The acid content can be determined by potentiometric measurement in a non-aqueous system. The non-chemically amplified negative resist composition according to this disclosure is preferably used after being prepared and filtered.

[0104] The non-chemically amplified negative resist composition of this disclosure can be alkaline developed during pattern formation by electron beam, ion beam, or EUV irradiation, and can form highly sensitive and high-resolution patterns. Therefore, it can be suitably used in microlithography processes such as the manufacturing of semiconductor integrated circuits, recording media, MEMS, optical devices, and imprint molds used therein. Furthermore, the non-chemically amplified negative resist composition of this disclosure is suitable for use as a negative resist composition for gradation exposure because it can achieve a slope γ of 2.0 or less in the rise of the resist film thickness in the sensitivity curve (contrast curve) between exposure amount and resist film thickness after development, and has high sensitivity. Note that the slope γ is calculated as the slope of the approximate straight line in the range of 0.0-0.5 for the normalized resist film thickness after development, and the exposure dose at that time is mC / cm 2 It is calculated using this method.

[0105] II. Method for Manufacturing Resist Patterns Other embodiments of this disclosure include: The process involves applying the non-chemically amplified negative resist composition of the present disclosure onto a substrate, then heat-treating it to form a resist film, and The present invention provides a method for manufacturing a resist pattern, which includes the step of exposing the resist film with an electron beam, ion beam, EUV, or X-ray and developing it.

[0106] According to the method for manufacturing a resist pattern of the present disclosure, since the non-chemically amplified negative resist composition of the present disclosure is used, alkaline development is possible, and a pattern with high sensitivity, high resolution and good shape can be formed.

[0107] The following explains each step in detail. (i) A step of applying a non-chemically amplified negative resist composition according to the present disclosure onto a substrate, followed by heat treatment to form a resist film. In this process, first, the above-mentioned non-chemically amplified negative resist composition is applied to the substrate. The coating method is not particularly limited as long as it can uniformly coat the non-chemically amplified negative resist composition onto the substrate surface, and various methods such as spray coating, roll coating, slit coating, and rotary coating can be used.

[0108] Next, the non-chemically amplified negative resist composition coated on the substrate is pre-baked (PAB) to remove the organic solvent and form a resist film. The pre-bake temperature can be appropriately determined depending on the components of the composition, their usage ratio, the type of organic solvent, etc., and is usually 80 to 160°C, preferably 90 to 150°C. The pre-bake time is usually about 30 seconds to 15 minutes.

[0109] (ii) Exposing the resist film with an electron beam, ion beam, EUV, or X-ray, and developing it. In this process, the resist film is first selectively exposed using an exposure apparatus such as an electron beam lithography apparatus or an EUV exposure apparatus, either by exposure through a mask having a predetermined pattern shape, or by drawing by direct irradiation with an electron beam without using the mask. For exposure, grayscale exposure may be performed. A known method can be appropriately selected and used for grayscale exposure. For example, grayscale exposure can be performed by adjusting the exposure focus, using the grayscale exposure function of a drawing exposure machine, or using a grayscale exposure mask. By performing grayscale exposure on the resist film, a textured pattern can be formed with protrusions of different heights and / or protrusions having inclined surfaces. The exposure light source is not particularly limited and can be an ArF excimer laser, KrF excimer laser, F2 excimer laser, EUV (Extreme Ultraviolet), electron beam, X-ray, or an ion beam such as helium or hydrogen.

[0110] Next, after exposure, post-exposure baking (PEB) may be performed. Since non-chemically amplified resist compositions substantially do not contain photoacid generators, there is no need to perform post-exposure baking to diffuse the acid. However, the sensitivity of the non-chemically amplified negative resist composition of this disclosure is improved by post-exposure baking, so it is preferable to perform post-exposure baking as appropriate. The conditions for PEB treatment are typically a temperature of 50-160°C and a duration of 0.1-15 minutes.

[0111] Next, the substrate treated with PEB as described above is developed using an alkaline developer to remove areas that were not exposed to light. Development methods include spraying, slitting, liquid immersion, dipping, and agitation immersion. Furthermore, as the alkaline developer for the non-chemically amplified negative resist composition of this disclosure, aqueous solutions of alkalis such as inorganic alkalis like sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia; primary amines such as ethylamine and n-propylamine; secondary amines such as diethylamine and di-n-butylamine; tertiary amines such as triethylamine and methyldimethylamine; alcohol amines such as dimethylethanolamine and triethanolamine; quaternary ammonium salts such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, and choline; and cyclic amines such as pyrrole and piperidine can be used. In addition, an appropriate amount of alcohol such as isopropyl alcohol and a nonionic surfactant can be added to the aqueous solution of the above alkalis. Among these alkaline developers, aqueous solutions of quaternary ammonium salts are preferred, and aqueous solutions of tetramethylammonium hydroxide and choline are preferred.

[0112] Furthermore, when using an aqueous solution of tetramethylammonium hydroxide (TMAH) as the alkaline developer, the concentration of the aqueous solution is preferably 0.1% to 25%, more preferably 0.2% to 5%, and particularly preferably 0.2% to 2.38%. An aqueous solution of tetramethylammonium hydroxide with a concentration of 2.38% is generally the most readily available in the semiconductor industry. Also, if the concentration of the aqueous solution of tetramethylammonium hydroxide is lower than 0.1%, the developer will be neutralized by carbon dioxide in the air, causing the sensitivity to fluctuate and making it difficult to obtain a stable product.

[0113] After development, a rinsing process is performed to wash away the alkaline developer and the resist composition dissolved by the alkaline developer from the substrate, and then the substrate is dried to obtain a resist pattern.

[0114] III. Mold Another embodiment of the present disclosure provides a mold having a textured pattern, wherein at least the protrusions contain a cured product of the non-chemically amplified negative resist composition of the present disclosure. The mold relating to this disclosure may have other components that are the same as those known, provided that it includes a cured product of the non-chemically amplified negative resist composition of this disclosure. The mold relating to this disclosure can be manufactured by the method for manufacturing the resist pattern of this disclosure. The mold according to this disclosure may be a three-dimensional mold having a surface pattern comprising at least one of the following: protrusions of different heights and protrusions having inclined surfaces. The molds relating to this disclosure can be suitably used, for example, as imprint molds, stampers for recording media, injection molding dies, and molds for manufacturing these.

[0115] This disclosure is not limited to the embodiments described above. The embodiments described above are illustrative, and any configuration that is substantially identical to the technical idea described in the claims of this disclosure and produces similar effects is included within the technical scope of this disclosure. [Examples]

[0116] The present disclosure will be described in detail below with reference to examples. These descriptions are not intended to limit the present disclosure. The structure and physical properties of the manufacturing examples were confirmed using the following equipment. MALDI-TOF MS: Manufactured by BRUKER, REFLEX II 1 H-NMR: JEOL, JEOL JNM-LA400WB Purity was measured using high-performance liquid chromatography (HPLC) (Shimadzu LC-10ADvp) under the following conditions (temperature: 40°C, flow rate: 1.0 mL / min, column: VP-ODS (4.7 mm × 150 mm), detector: SPD-M10Avp, mobile phase: acetonitrile / water). Glass transition temperature (Tg): Using a differential thermal analyzer (Shimadzu DSC-60), approximately 4 mg of pattern-forming material was heated to 200°C at a rate of 10°C / min, cooled to room temperature, and then heated again to 200°C at a rate of 10°C / min. The glass transition temperature was defined as the intersection of the two tangent lines of the smooth curves before and after the inflection point of the DTA curve. If no inflection point corresponding to the glass transition temperature was observed in the DTA curve by 200°C, the Tg was judged to be 200°C or higher.

[0117] <Synthesis Example 1: Synthesis of Phenolic Compound A> To a solution consisting of 20 mL of 10% potassium hydroxide aqueous solution and 20 mL of ethanol, 6.3 g (10 mmol) of the phenolic compound represented by the following chemical formula (10) (TekOC-4HBPA: Honshu Chemical Industry Co., Ltd.) was added and stirred at room temperature until dissolved. To this solution, 7.0 mL (80 mmol) of 37% formalin aqueous solution was slowly added at room temperature. Furthermore, after stirring at 40°C under a nitrogen atmosphere for 24 hours, the solution was added to 200 mL of water in a beaker. While cooling this in an ice bath, 2.0 wt% acetic acid aqueous solution was slowly added until the pH reached 5.0. The precipitate was filtered off, thoroughly washed with water, dried, and purified by high-performance liquid chromatography to obtain 4.8 g of phenolic compound A represented by the following chemical formula (11). The structure of the obtained phenolic compound A was confirmed as follows: 1 The analysis was performed using 1H-NMR spectroscopy and MALDI-TOF MS. The glass transition temperature (Tg) was determined by differential scanning calorimetry. The analysis results are shown below.

[0118] [ka]

[0119] [ka]

[0120] (Analysis results) 1 H-NMR:0.44(6H,-CH3), 1.09-1.67(14H,cHex), 2.03(12H, Ph-CH3), 2.64-2.67(4H,cHex), 4.44-4.51(8H,Ph-CH2-OH), 5.19-5.25(4H,Ph-CH2-OH), 6.74-7.02(8H, Aromatic H), 8.10-8.13(4H,Ph-OH) Purity: 92% MALDI-TOF MS: 752.97 Glass transition temperature (Tg): 200°C or higher

[0121] <Synthesis Example 2: Synthesis of Nitrogen-Containing Basic Compound (B-01)> Under a nitrogen atmosphere, 0.25 g (1.69 mmol) of N-(2-chloroethyl)dibenzylamine hydrochloride and 0.54 g (1.69 mmol) of (TekOC-4HBPA: manufactured by Honshu Chemical Industry Co., Ltd.) were dissolved in 30 mL of acetone in a 100 mL three-necked flask. Then 1.17 g (8.5 mmol) of potassium carbonate was added, and the reaction was carried out at 60°C for 48 hours. After the reaction, the residual potassium carbonate was removed, the solvent was removed by distillation, and the reaction product was allowed to dry before being dissolved in water. Then ethyl acetate was added to extract the target product from the aqueous phase, and after further distillation of the ethyl acetate, the product was separated by high-performance liquid chromatography and purified to obtain waxy solid nitrogen-containing basic compounds (B-01') (molecular weight: 856.2) and (B-01") (molecular weight: 856.2). The structure was determined by MALDI-TOF MS, high-performance liquid chromatography, and 1 This was confirmed by 1H-NMR spectroscopy. 1 The differences in H-NMR spectra and HPLC retention times indicate that the basic compounds (B-01') and (B-01") are isomers.

[0122] [ka]

[0123] (B-01') Confirmed with MALDI-TOF MS: [M+H] 856.8 HPLC (アセトニトリル / water=8 / 2) retention time: 73.5 minutes 1 H-NMR (400 MHz, DMSO-d6, TMS): 9.00&8.98(d)δ(ppm)(aromatic-OH), 8.90(aromatic-OH), 6.54~7.37(aromatic-H), 3.98(aromatic-O-CH2-), 3.65(aromatic-CH2-N), 2.75(N-CH2-CH2-), 2.63( Cyclohexane-H2)2.01~2.05(aromatic-CH3), 1.65(Cyclohexane-H2), 1.50(Cyclohexane-H2), 1.32(Cyclohexane-H), 1.08(Cyclohexane-H2), 0.44(-C(-CH3)2-)

[0124] (B-01”) MALDI-TOF MSにてconfirmed:[M+H]856.8 HPLC (アセトニトリル / water=8 / 2) retention time: 89.0 minutes 1 H-NMR (400 MHz, DMSO-d6, TMS): 8.98δ(ppm)(aromatic-OH), 8.92&8.90(d)(aromatic-OH), 6.54~7.40(aromatic-H), 4.04(aromatic-O-CH2-), 3.68(aromatic-CH2-N), 2.79(N-CH2-CH2-), 2.65( Cyclohexane-H2)2.01~2.10(aromatic-CH3), 1.65(Cyclohexane-H2), 1.51(Cyclohexane-H2), 1.32(Cyclohexane-H), 1.07(Cyclohexane-H2), 0.43(-C(-CH3)2-)

[0125] [Examples 1 to 3, Comparative Example 1: Non-chemically amplified ネガ-type レジスト composition] The phenolic compound (A) obtained in Synthesis Example 1, the nitrogen-containing basic compound (B) obtained in Synthesis Example 2, and an organic solvent (propylene glycol monomethyl ether) were mixed in the proportions shown in Table 1 to form a homogeneous solution. Each sample solution was filtered through a 0.1 μm Teflon® filter to prepare the non-chemically amplified negative resist compositions of Examples 1 to 3. Furthermore, without using the nitrogen-containing basic compound (B), a homogeneous solution of the phenolic compound (A) and an organic solvent was prepared in the proportions shown in Table 1, and filtered through a 0.1 μm Teflon® filter to prepare the non-chemically amplified negative resist composition of Comparative Example 1.

[0126] [Table 1]

[0127] [Manufacturing of resist patterns] Using the non-chemically amplified negative resist compositions obtained in Examples 1-3 and Comparative Example 1, resist patterns were formed and evaluated using the method described below. (1) Acquisition of sensitivity curve Each non-chemically amplified negative resist composition was uniformly coated onto a 6-inch silicon substrate using a spinner, and a pre-bake (PAB) treatment was performed at 110°C for 60 seconds to form a resist film with a thickness of 2 μm. For the above resist film, an electron beam lithography system (acceleration voltage 100 keV) was used to apply 50 μC / cm² to each 1 mm square area. 2 Drawing was performed by gradually changing the exposure level. After drawing was completed, the material was developed with a 2.38% TMAH aqueous solution (23°C) for 60 seconds, and then rinsed with pure water for 60 seconds to obtain a resist curing pattern corresponding to the exposure level.

[0128] [Evaluation (Sensitivity Curve)] Sensitivity was determined by measuring the height of the cured resist in relation to the exposure amount using a micro-shape measuring instrument (Kosaka Laboratory: ET4000), and the sensitivity curve (contrast curve) of exposure amount and post-developed resist film thickness was obtained, as shown in Figure 1.

[0129] (2) Formation of resist uneven pattern Each non-chemically amplified negative resist composition was uniformly coated onto a 6-inch silicon substrate using a spinner, and a pre-bake (PAB) was performed at 110°C for 60 seconds to form a resist film with the same thickness as when the sensitivity curve was obtained. The resist film described above was lithographed using an electron beam lithography system (acceleration voltage 100 keV). Specifically, based on a previously acquired sensitivity curve, layers were assigned according to the desired final resist height, and lithography was performed by setting an appropriate exposure amount for each layer. After lithography was completed, the film was developed with a 2.38% TMAH aqueous solution (23°C) for 60 seconds, and then rinsed with pure water for 60 seconds to form a textured pattern.

[0130] [Evaluation (Uneven Pattern Cross-Sectional Shape)] The cross-sectional shape of the uneven pattern was observed using a scanning electron microscope (SEM) (ZEISS). Figure 2 shows the scanning electron microscope images of Example 1 and Comparative Example 1.

[0131] [Summary of results] A comparison of the sensitivity curves of Comparative Example 1 and Examples 1-3 in Figure 1 revealed that the non-chemically amplified negative resist composition of this disclosure, which uses a specific nitrogen-containing basic compound (B) in combination with the specific phenolic compound (A) that functions as both a resist substrate and a crosslinking agent, is capable of alkaline development and can form patterns with higher sensitivity and superior resolution. Furthermore, a comparison of Examples 1-3 showed that the sensitivity increased with increasing amounts of the specific nitrogen-containing basic compound (B). Referring to Figure 2, it was revealed that the non-chemically amplified negative resist composition of this disclosure has high sensitivity, which allows for a higher height of the surface texture compared to the comparative example. < / mw> < / mw>

Claims

1. A phenolic compound (A) having a molecular weight of 400 to 2500, having two or more phenolic hydroxyl groups in one molecule, and having three or more substituents selected from the group consisting of hydroxymethyl groups and alkoxymethyl groups at the ortho position of the phenolic hydroxyl groups in one molecule, A negative-type resist composition comprising a nitrogen-containing basic compound (B) having one or more aromatic rings per molecule and one or more phenolic hydroxyl groups and / or phenoxy groups per molecule, with a molecular weight of 400 to 3000, wherein The phenolic compound (A) has a glass transition temperature (Tg) of 60°C or higher. The nitrogen-containing basic compound (B) is represented by the following formula (I), A non-chemically amplified negative-type resist composition in which the content of the phenolic compound (A) in the total solid content of the negative-type resist composition is 70% by mass or more, and the content of the acid generator is less than 1 part by mass per 100 parts by mass of the phenolic compound (A). 【Chemistry 1】 (In formula (I), R ａ R represents an alkylene group which may have a direct bond or an oxy group (-O-), ｂ and R ｃ Each of these is independently a monovalent organic group which may have an oxy group (-O-), and Ar is a monovalent organic group having an aromatic ring. However, each molecule contains one or more phenolic hydroxyl groups and / or phenoxy groups.

2. The non-chemically amplified negative resist composition according to claim 1, wherein the content of the nitrogen-containing basic compound (B) is 0.1 to 5 parts by mass per 100 parts by mass of the phenolic compound (A).

3. The non-chemically amplified negative resist composition according to claim 1 or 2, wherein the nitrogen-containing basic compound (B) has the same carbon skeleton as the phenolic compound (A).

4. The non-chemically amplified negative resist composition according to any one of claims 1 to 3, wherein the nitrogen-containing basic compound (B) does not have one or more substituents selected from the group consisting of a hydroxymethyl group and an alkoxymethyl group at the ortho position of the phenolic hydroxyl group.

5. The non-chemically amplified negative resist composition according to any one of claims 1 to 4, wherein the total content of the specific phenolic compound (A) and the nitrogen-containing basic compound (B) is 90% by mass or more with respect to the total solid content of the resist composition.

6. A step of applying a non-chemically amplified negative resist composition according to any one of claims 1 to 5 onto a substrate, then heat-treating it to form a resist film, and The process of exposing the resist film with an electron beam, ion beam, EUV, or X-ray, and developing it. A method for manufacturing a resist pattern that includes [the specified element].

7. A mold having an uneven pattern, wherein at least the protrusions contain a cured product of the non-chemically amplified negative resist composition described in any one of claims 1 to 5.

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