Positive lift-off resist composition and method for producing resist pattern using same

Abstract

A positive lift-off resist composition is provided. The positive lift-off resist composition comprises a polymer (A) having a specific structure and a cLogP of 2.76 to 3.35, a photoacid generator (B), and a solvent (C).

Description

[Technical field]

[0001] The present invention relates to a positive lift-off resist composition and a method for producing a resist pattern using the same. [Background technology]

[0002] In the manufacturing process of devices such as semiconductors, microfabrication is generally performed by lithography techniques using resist compositions. The microfabrication process includes forming a thin photoresist layer on a semiconductor substrate such as a silicon wafer, covering the layer with a mask pattern corresponding to the pattern of the target device, exposing the layer to active light such as ultraviolet light through the mask pattern, developing the exposed layer to obtain a photoresist pattern, and etching the substrate using the obtained photoresist pattern as a protective film, thereby forming fine irregularities corresponding to the above-mentioned pattern.

[0003] A lift-off method is known in which a film of a material such as a metal is formed on a formed resist pattern by vapor deposition or the like, and the resist is then removed with a solvent, removing the material on the resist pattern and leaving the material such as a metal only in the areas where the resist pattern was not formed. To perform the lift-off method, it is preferable that the resist pattern has an inverse tapered shape, and a negative resist composition is often used because it is easy to form an inverse tapered shape. For example, it has been proposed to form an inverse tapered shape by using a negative resist composition containing a crosslinking agent (Patent Document 1).

[0004] Generally, light from exposure does not sufficiently reach the lower part of the resist film, and acid generation is suppressed at the lower part of the resist film, and the acid generated at the lower part of the resist film is inactivated by the influence of the substrate. Therefore, the resist pattern formed using the positive resist composition tends to have a tapered shape (footing shape). As a method for forming a resist pattern with an inverse tapered shape using a positive resist composition, a method has been proposed in which a positive resist composition containing a dissolution rate adjuster is used (Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2017 / 169866 [Patent Document 2] International Publication No. 2020 / 193686 Summary of the Invention [Problem to be solved by the invention]

[0006] The present inventors have found that there are one or more problems that need to be improved with respect to positive lift-off resist compositions and methods for producing resist patterns using the same. These problems include, for example: Sufficient resolution cannot be obtained; a resist pattern shape suitable for lift-off cannot be formed; the sensitivity of the resist composition is insufficient; a resist pattern shape cannot be formed in a thin film; the heat resistance of the resist pattern is insufficient; the solubility of the resist film in the exposed areas cannot be sufficiently controlled; the developer cannot sufficiently dissolve the soluble areas. The present invention has been made based on the above-mentioned technical background, and provides a positive lift-off resist composition and a method for producing a resist pattern using the same. [Means for solving the problem]

[0007] The positive lift-off resist composition according to the present invention comprises a polymer (A), a photoacid generator (B) and a solvent (C). Where: The cLogP of the polymer (A) is 2.76 to 3.35; The polymer (A) comprises at least one of the repeating units represented by formulas (A-1) to (A-4), and The content of the dissolution rate regulator (D) is 0 to 1.0 part by mass relative to 100 parts by mass of the polymer (A), and the dissolution rate regulator (D) is represented by formula (D-1). [ka] (where: R 11 , R 21 , R 41 and R 45 are each independently C 1-5 alkyl (wherein -CH2- in the alkyl may be replaced by -O-); R 12 , R 13 , R 14 , R 22 , R 23 , R 24 , R 32 , R 33 , R 34 , R 42 , R 43 , and R 44 are each independently hydrogen, C 1-5 Alkyl, C 1-5 alkoxy, or -COOH; p11 is 0 to 4, p15 is 1 to 2, and p11 + p15 ≦ 5; p21 is 0 to 5; p41 is 0-4, p45 is 1-2, and p41+p45≦5; P 31 is C 4-20 Alkyl (wherein part or all of the alkyl may form a ring, and part or all of the H in the alkyl may be substituted with halogen) [ka] (In the formula, each nd1 is independently 1, 2 or 3; nd2 is independently 0, 1, 2 or 3; R d1 are each independently 1-7 is alkyl, Ld is C 1-15 a divalent alkylene of the formula (which may be substituted by an aryl which may be hydroxy-substituted), d (which may form a ring with a substituent other than the above)

[0008] The method for producing a resist pattern according to the present invention comprises the following steps. (1) applying the composition described above over a substrate; (2) heating the composition to form a resist layer; (3) exposing the resist layer; (4) post-exposure baking the resist layer; and (5) developing the resist layer.

[0009] A method for producing a device according to the present invention comprises the method described above. Effect of the Invention

[0010] According to the present invention, one or more of the following effects can be achieved. Sufficient resolution can be obtained. A resist pattern shape suitable for lift-off can be formed. The sensitivity of the resist composition is high. A resist pattern shape can be formed in a thin film. The heat resistance of the resist pattern is high. The solubility of the resist film in the exposed area can be accurately controlled. Dissolution of the soluble area by the developer can be suitably promoted. It is possible to control the uneven distribution of the photoacid generator and to control the pattern shape. It is possible to obtain a resist film and resist pattern suitable for the lift-off process without requiring a dissolution rate regulator, a crosslinker, and / or a plasticizer. [Brief description of the drawings]

[0011] [Figure 1] 1A to 1C are conceptual cross-sectional views for explaining a resist pattern having an inverse tapered shape, a resist pattern having an overhang shape, and a modified example of the resist pattern having the overhang shape. [Diagram 2]FIG. 2 is a conceptual diagram showing a cross-sectional shape of a resist pattern. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] definition In this specification, unless otherwise specifically stated, the definitions and examples set forth in this paragraph shall be followed. The singular includes the plural, and "a" or "the" means "at least one." An element of a concept may be expressed by a plurality of species, and when an amount thereof (e.g., mass % or mole %) is stated, the amount refers to the sum of the plurality of species. "And / or" includes all combinations of the elements as well as its use alone. When a numerical range is indicated using "~" or "-", it includes both endpoints and the units are the same. For example, 5 to 25 mol % means 5 mol % or more and 25 mol % or less. "C x-y ", "C x ~C y " and "C x " refers to the number of carbons in a molecule or substituent. For example, C 1-6 Alkyl refers to an alkyl chain having from 1 to 6 carbons (methyl, ethyl, propyl, butyl, pentyl, hexyl, etc.). When a polymer has multiple types of repeating units, these repeating units are copolymerized. These copolymerizations may be alternating copolymerization, random copolymerization, block copolymerization, graft copolymerization, or a mixture of these. When polymers or resins are shown by structural formulas, the n or m in parentheses indicates the number of repeats. Temperature is measured in degrees Celsius. For example, 20 degrees means 20 degrees Celsius. The additive refers to a compound having that function (for example, in the case of a base generator, it is a compound that generates a base). The compound may be dissolved or dispersed in a solvent and added to the composition. In one embodiment of the present invention, such a solvent is preferably contained in the composition of the present invention as the solvent (C) or another component.

[0013] Hereinafter, an embodiment of the present invention will be described in detail.

[0014] <Positive Lift-Off Resist Composition> The positive lift-off resist composition (hereinafter sometimes simply referred to as the composition) according to the present invention comprises a polymer (A) having a specific structure, a photoacid generator (B), and a solvent (C). The composition according to the present invention is preferably a thin film positive lift-off chemically amplified resist composition. In the present invention, the thickness of the resist film is preferably 50 to 1,500 nm (more preferably 90 to 1,200 nm; even more preferably 90 to 1,100 nm; still more preferably 90 to 950 nm). A thin film means that the resist film formed is 1 μm or less. The viscosity of the composition according to the present invention is preferably 5 to 900 cP (more preferably 7 to 700 cP), where the viscosity is measured at 25° C. using a capillary viscometer. The composition according to the present invention is more preferably a thin film KrF positive lift-off chemically amplified resist composition.

[0015] Polymer (A) The polymer (A) used in the present invention is one that reacts with an acid to increase its solubility in an alkaline aqueous solution. Such a polymer has, for example, an acid group protected by a protecting group, and when an acid is added from the outside, the protecting group is eliminated, increasing the solubility in an alkaline aqueous solution. The polymer (A) contains at least one of the repeating units shown in the following (A-1), (A-2), (A-3), or (A-4). The cLogP of the polymer (A) is 2.76 to 3.35 (preferably 2.77 to 3.12; more preferably 2.78 to 3.00; even more preferably 2.78 to 2.99). Here, cLogP is a value calculated by the common logarithm LogP of the partition coefficient P between 1-octanol and water. cLogP can be calculated by the method described in "Prediction of Hydrophobic (Lipophilic) Properties of Small Organic Molecules" (Arup K. Ghose et al., J. Phys. Chem. A 1998, 102, 3762-3772). In this specification, the cLogP of each repeating unit is calculated using CambridgeSoft's ChemDraw Pro 12.0, and the cLogP of each repeating unit is added together by the cLogP × composition ratio to calculate the cLogP of the polymer (A). When calculating the cLogP of each repeating unit, it is assumed that each repeating unit is polymerized, and the calculation is performed without including the terminal outside the repeating unit. For example, if the cLogP of repeating units A, B and C of polymer (A) are 2.88, 3.27 and 2.05, respectively, with a constituent ratio of 6:2:2, the cLogP of polymer (A) is 2.79. Without being bound by theory, it is believed that the cLogP in the above range provides at least one of the above effects. For example, the solubility of the exposed area can be precisely controlled. This makes it possible to obtain a polymer having properties useful for positive lift-off from among a large number of polymers.

[0016] Formula (A-1) is as follows: [ka] Where: R 11 are each independently C 1-5 alkyl (wherein -CH2- in the alkyl may be replaced by -O-); R 12 , R 13 , and R 14 are each independently hydrogen, C 1-5Alkyl, C 1-5 alkoxy, or -COOH; p11 is 0 to 4, p15 is 1 to 2, and p11+p15≦5. In the present invention, the expression "-CH2- (methylene) in the alkyl group may be replaced by -O- (oxy)" means that oxy may be present between carbon atoms in the alkyl group by replacement, and does not intend that the terminal carbon in the alkyl group becomes oxy, that is, that it has alkoxy or hydroxy. The same applies hereinafter.

[0017] R 11 is preferably methyl or ethyl; more preferably methyl. R 12 , R 13 , and R 14 is preferably hydrogen or methyl; more preferably hydrogen. Polymer (A) can contain multiple types of structural units represented by formula (A-1). For example, it can have a structural unit of p15=1 and a structural unit of p15=2 in a ratio of 1:1. In this case, p15=1.5 as a whole. Hereinafter, unless otherwise specified, the same applies to the numbers expressing resins and polymers in the present invention. p11 is preferably 0 or 1; more preferably 0. p15 is preferably 0 or 1; more preferably 1.

[0018] Specific examples of formula (A-1) include the following. [ka]

[0019] Formula (A-2) is as follows. [ka] Where: R 21 are each independently 1-5alkyl (wherein -CH2- in the alkyl may be replaced by -O-); R 22 , R 23 , and R 24 are each independently hydrogen, C 1-5 Alkyl, C 1-5 alkoxy, or -COOH; p21 is 0 to 5.

[0020] R 21 is preferably methyl, ethyl, t-butyl or t-butoxy; more preferably methyl or ethyl; more preferably methyl. R 22 , R 23 , and R 24 is preferably hydrogen or methyl; more preferably hydrogen. p21 is preferably 0, 1, 2, 3, 4 or 5; more preferably 0 or 1; and even more preferably 0.

[0021] Specific examples of formula (A-2) include the following. [ka]

[0022] Equation (A-3) is as follows. [ka] Where: R 32 , R 33 , and R 34 are each independently hydrogen, C 1-5 Alkyl, C 1-5 Alkoxy, or -COOH. P 31 is C 4-20 Here, a part or all of the alkyl may form a ring, and a part or all of the H of the alkyl may be replaced with a halogen. 31 The alkyl portion of P is preferably branched or cyclic.31 C 4-20 When the alkyl is substituted with a halogen, it is preferable that the entire alkyl group is substituted, and the halogen is preferably F or Cl; more preferably F. 31 C 4-20 In a preferred embodiment of the present invention, H of the alkyl is not substituted with halogen.

[0023] R 32 , R 33 , and R 34 is preferably hydrogen, methyl, ethyl, t-butyl, methoxy, t-butoxy or -COOH; more preferably hydrogen or methyl; and even more preferably hydrogen. P 31 is preferably methyl, isopropyl, t-butyl, cyclopentyl, methylcyclopentyl, ethylcyclopentyl, cyclohexyl, methylcyclohexyl, ethylcyclohexyl, adamantyl, methyladamantyl or ethyladamantyl; more preferably t-butyl, ethylcyclopentyl, ethylcyclohexyl or ethyladamantyl; even more preferably t-butyl, ethylcyclopentyl or ethyladamantyl; and even more preferably t-butyl.

[0024] Specific examples of formula (A-3) include the following. [ka]

[0025] Equation (A-4) is as follows. [ka] Where: R 41 and R 45 are each independently 1-5 alkyl (wherein -CH2- in the alkyl may be replaced by -O-); R 42 , R 43 , and R 44are each independently hydrogen, C 1-5 Alkyl, C 1-5 alkoxy, or -COOH; p41 is 0 to 4, p45 is 1 to 2, and p41+p45≦5.

[0026] R 45 is preferably methyl, t-butyl or -CH(CH3)-O-CH2CH3 (more preferably methyl). R 41 is preferably methyl, ethyl or t-butyl; more preferably methyl. R 42 , R 43 , and R 44 is preferably hydrogen or methyl; more preferably hydrogen. p41 is preferably 0, 1, 2, 3 or 4; more preferably 0 or 1; and even more preferably 0. p45 is preferably 1 or 2; more preferably 1.

[0027] Specific examples of formula (A-4) include the following. [ka]

[0028] These structural units are appropriately blended depending on the purpose, and the blending ratio thereof is not particularly limited as long as the cLogP satisfies 2.76 to 3.35. It is preferable that they are blended so that the increase rate of the solubility in an alkaline aqueous solution by the acid is appropriate. The number of repeating units n of the repeating units (A-1), (A-2), (A-3) and (A-4) in the polymer (A) A-1 , n A-2 , n A-3 and n A-4 The following explains this. n A-1 / (n A-1 +n A-2 +n A-3 +n A-4) is preferably 40 to 80% (more preferably 50 to 80%; even more preferably 55 to 75%; still more preferably 55 to 65%). n A-2 / (n A-1 +n A-2 +n A-3 +n A-4 ) is preferably 0 to 40% (more preferably 5 to 35%; even more preferably 5 to 25%; still more preferably 15 to 25%). n A-3 / (n A-1 +n A-2 +n A-3 +n A-4 ) is preferably 0 to 40% (more preferably 10 to 35%; even more preferably 15 to 35%; still more preferably 15 to 25%). n A-4 / (n A-1 +n A-2 +n A-3 +n A-4 ) is preferably 0 to 60% (more preferably 10 to 55%; even more preferably 20 to 50%; still more preferably 35 to 45%). n A-1 / (n A-1 +n A-2 +n A-3 +n A-4 )=40~80%, n A-2 / (n A-1 +n A-2 +n A-3 +n A-4 )=0~40%, n A-3 / (n A-1 +n A-2 +n A-3 +n A-4 ) = 0 to 40%, and n A-4 / (n A-1 +n A-2 +n A-3 +n A-4 )=0 to 60% is a preferred embodiment. In one aspect of the present invention, (n A-3 +n A-4 ) / (n A-1 +n A-2 +n A-3 +n A-4)>0%. This is because the presence of a unit that can be deprotected by an acid, such as (A-3) or (A-4), makes it possible to increase the solubility of the polymer portion of the resist film in a developer. A-3 >0 and n A-4 =0, or n A-3 = 0 and n A-4 >0 is more preferable. A-2 >0 and n A-3 >0 and / or n A-2 = 0 and n A-4 >0 is preferred.

[0029] The polymer (A) may contain repeating units other than the repeating units represented by (A-1), (A-2), (A-3) and (A-4). The total number of all repeating units contained in the polymer (A), n total So, (n A-1 +n A-2 +n A-3 +n A-4 ) / n total is preferably 80 to 100% (more preferably 90 to 100%; even more preferably 95 to 100%; still more preferably 100%). In one preferred embodiment of the present invention, the copolymer does not contain any other structural units than the repeating units represented by (A-1), (A-2), (A-3) and (A-4).

[0030] Specific examples of the polymer (A) include the following. [ka] [ka] [ka]

[0031] The following polymer (A) has repeating units of (A-1), (A-2) and (A-3). After forming a resist film from the composition of the present invention, the resist film receives acid from the photoacid generator (B) by exposure, and the protecting group of the (A-3) unit in the polymer (A) is removed. The cLogP of the corresponding (A-3) unit portion changes from 2.05 to 0.91. As a result, the cLogP of the resist film in the acid-accepting portion changes from 2.79 to 2.56 (Δ0.23) for the entire polymer (A). [ka]

[0032] The following polymer (A) has repeating units of (A-1), (A-2) and (A-3). After forming a resist film from the composition of the present invention, the resist film receives acid from the photoacid generator (B) by exposure, and the protecting group of the (A-3) unit in the polymer (A) is removed. The cLogP of the corresponding (A-3) unit portion changes from 3.01 to 0.91. As a result, the cLogP of the resist film in the acid-accepting portion changes from 2.98 to 2.56 (Δ0.42) for the entire polymer (A). [ka]

[0033] The following polymer (A) has repeating units of (A-1) and two types of (A-4). After forming a resist film from the composition of the present invention, it receives acid from the photoacid generator (B) by exposure, and the protecting group of the (A-4) unit shown on the right in the polymer (A) is removed. The cLogP of the corresponding (A-4) unit portion changes from 3.84 to 2.88. As a result, the cLogP of the resist film in the acid-accepting portion changes from 3.30 to 3.11 (Δ0.19) for the entire polymer (A). [ka]

[0034] In the embodiment of the present invention, the amount of decrease in cLogP of the entire polymer (A) before and after exposure is preferably 0.15 to 0.55 (more preferably 0.18 to 0.50; even more preferably 0.19 to 0.45). Without being bound by theory, it is believed that the decrease in cLogP of the resist film in the exposed region within the above range allows the dissolution of the exposed region by the developer to proceed favorably.

[0035] Comparative composition 1 described below uses polymer A1 and polymer G in a mass ratio of 1:1. The cLogP is 2.79 and 3.21, respectively, and the average cLogP is 3.00. After forming a resist film from comparative composition 1, the polymer A1 receives acid from the photoacid generator (B) by exposure, and the protecting group of the (A-3) unit in the polymer A1 is removed. As described above, the cLogP of the polymer A1 portion changes from 2.79 to 2.56. On the other hand, polymer G, which is a novolac resin, is not deprotected, so the cLogP remains at 3.21. Therefore, the average cLogP of polymer A1 and polymer G after exposure is 2.89 (Δ0.11). [ka]

[0036] The mass average molecular weight (hereinafter sometimes referred to as Mw) of the polymer (A) is preferably from 1,000 to 50,000 (more preferably from 2,000 to 30,000; even more preferably from 5,000 to 20,000; still more preferably from 8,000 to 15,000). The number average molecular weight (hereinafter sometimes referred to as Mn) of the polymer (A) is preferably from 1,000 to 50,000 (more preferably from 2,000 to 30,000). In the present invention, Mw and Mn can be measured by gel permeation chromatography (GPC). In one preferred example, the GPC column is set at 40° C., the elution solvent is tetrahydrofuran at 0.6 mL / min, and monodisperse polystyrene is used as the standard.

[0037] The following description is given for the purpose of explanation. In the composition of the present invention, these polymers (A) can be used in combination of two or more kinds as long as they are represented by the above formula. For example, a composition containing both of the following two kinds of polymers (A) is also one embodiment of the present invention. [ka] The same applies to the composition of the present invention in the following description unless otherwise specified. Preferably, the polymer (A) in the composition of the present invention is one or two polymers, more preferably, the polymer (A) is one polymer. Variations in Mw distribution and polymerization are permitted.

[0038] The content of polymer (A) is preferably 1 to 20 mass % (more preferably 5 to 19 mass %; even more preferably 10 to 18 mass %; still more preferably 14 to 18 mass %) based on the composition.

[0039] Photoacid generator (B) The composition according to the present invention comprises a photoacid generator (B). Here, the photoacid generator (B) releases an acid upon irradiation with light. Preferably, the acid derived from the photoacid generator (B) acts on the polymer (A) to increase the solubility of the polymer (A) in an alkaline aqueous solution. For example, when the polymer (A) has an acid group protected by a protecting group, the protecting group is removed by the acid. The photoacid generator (B) used in the composition according to the present invention can be selected from conventionally known ones.

[0040] The photoacid generator (B) releases an acid upon exposure to light. The acid dissociation constant pKa(H2O) of the acid is preferably from -20 to 1.4 (more preferably from -16 to 1.4; even more preferably from -16 to 1.2; still more preferably from -16 to 1.1).

[0041] The photoacid generator (B) is preferably represented by the following formula (B-1) or contains a structure of formula (B-2): More preferably, the photoacid generator (B) is represented by formula (B-1).

[0042] Formula (B-1) is as follows: B n+ Cation B n- Anion (B-1) where B n+ The cation is a cation represented by formula (BC1), a cation represented by formula (BC2), a cation represented by formula (BC3), or a cation represented by formula (BC4) (preferably a cation represented by formula (BC1) or (BC2); more preferably a cation represented by formula (BC1)). n+ The cation as a whole has a valency of n, where n is 1 to 3. B n- The anion is an anion represented by formula (BA1), an anion represented by formula (BA2), an anion represented by formula (BA3), an anion represented by formula (BA4), or an anion represented by formula (BA5) (preferably an anion represented by formula (BA1) or an anion represented by formula (BA5); more preferably an anion represented by formula (BA5)). n- The anion is a sulfonate anion. B n- The anion as a whole has a valency of n. n is preferably 1 or 2; more preferably 1. Without being bound by theory, it is believed that by using the above-mentioned photoacid generator (B), it is possible to control the amount of photoacid generator (B) present near the bottom surface during resist film formation, and it is possible to control the pattern shape to be an inverse tapered shape. In a positive resist, the exposed area is solubilized, but the amount of light reaching the area decreases as it approaches the bottom surface of the resist film, so it is effective to control the pattern shape by the amount of photoacid generator (B) present.

[0043] Equation (BC1) is as follows: [ka] Where: R b1 are each independently 1-6Alkyl, C 1-6 Alkoxy, C 6-12 Aryl, C 6-12 Arylthio, or C 6-12 aryloxy; and each nb1 is independently 0, 1, 2 or 3.

[0044] R b1 is preferably methyl, ethyl, t-butyl, methoxy, ethoxy, phenylthio, or phenyloxy (more preferably t-butyl, methoxy, ethoxy, phenylthio, or phenyloxy). All nb1 are 1 and all R b1 In another preferred embodiment, all nb1's are 0.

[0045] Specific examples of formula (BC1) include the following. [ka]

[0046] Equation (BC2) is as follows. [ka] Where: R b2 are each independently 1-6 Alkyl, C 1-6 Alkoxy, or C 6-12 is aryl, Each nb2 is independently 0, 1, 2 or 3.

[0047] R b2 is preferably C 4-6 Each R in the formula is an alkyl having a branched structure. b2 may be the same or different, and it is more preferable that they are the same. b2 is more preferably t-butyl or 1,1-dimethylpropyl (even more preferably t-butyl). Each nb2 is preferably 1.

[0048] Specific examples of formula (BC2) include the following. [ka]

[0049] Equation (BC3) is as follows: [ka] Where: R b3 are each independently 1-6 Alkyl, C 1-6 Alkoxy, or C 6-12 is aryl, R b4 are each independently 1-6 is alkyl, Each nb3 is independently 0, 1, 2 or 3.

[0050] R b3 are preferably each independently methyl, ethyl, methoxy, or ethoxy (more preferably each independently methyl or methoxy). R b4 is preferably methyl or ethyl (more preferably methyl).nb3 is preferably 1, 2 or 3 (more preferably 3).

[0051] Specific examples of formula (BC3) include the following. [ka]

[0052] Equation (BC4) is as follows: [ka] Where: L b1 is a single bond or C 1-3wherein methylene in the alkylene may be replaced by carbonyl; R b5 are each independently 1-6 Alkyl, C 1-6 Alkoxy, or C 6-12 is aryl, R b6 are each independently 1-6 is alkyl, Each nb4 is independently 0, 1, 2 or 3.

[0053] L b1 is preferably a single bond or ethylene replaced by carbonyl. R b5 is preferably C 1-6 Alkyl, C 1-6 Alkoxy, more preferably C 3-6 It is alkoxy (more preferably C4 alkoxy; even more preferably n-butoxy). R b6 is preferably C 3-6 It is preferably alkyl (more preferably n-butyl). nb4 is preferably 0, 1 or 2 (more preferably 0 or 2).

[0054] Specific examples of formula (BC4) include the following. [ka]

[0055] Equation (BA1) is as follows: [ka] Here, R b7 are each independently 1-6 Fluorine-substituted alkyl, C 1-6 Fluorine-substituted alkoxy, or C 1-6For example, -CF3 means that all hydrogen atoms of methyl (C1) are replaced with fluorine atoms. The fluorine replacement means that some or all of the hydrogen atoms in the alkyl moiety are replaced with fluorine atoms, and more preferably, all of the hydrogen atoms are replaced with fluorine atoms. R b7 The alkyl portion of is preferably methyl, ethyl or t-butyl (more preferably methyl). R b7 is preferably fluorine-substituted alkyl (more preferably -CF3).

[0056] Specific examples of formula (BA1) include the following. [ka]

[0057] Equation (BA2) is as follows: [ka] Here, R b8 is C 1-10 Fluorine-substituted alkyl, C 1-6 Fluorine-substituted alkoxy, C 6-12 Fluorine-substituted aryl, C 2-12 Fluorine-substituted acyl, or C 6-12 It is a fluorine-substituted alkoxyaryl. For example, -CF3 means that all hydrogen atoms of methyl (C1) are substituted with fluorine atoms. The fluorine substitution means that some or all of the hydrogen atoms in the alkyl moiety are substituted with fluorine atoms, and more preferably, all of the hydrogen atoms are substituted with fluorine atoms. R b8 The alkyl portion of R is preferably linear. b8 is preferably C 1-6 Fluorine-substituted alkyl (more preferably C 2-6 Fluorine-substituted alkyl). R b8 The alkyl portion of R is preferably methyl, ethyl, propyl, butyl, or pentyl (more preferably propyl, butyl, or pentyl; even more preferably butyl; even more preferably n-butyl). b8The alkyl portion of is preferably straight chain.

[0058] Specific examples of formula (BA2) include the following. C4F9SO3 - , C3F7SO3 -

[0059] Equation (BA3) is as follows: [ka] Where: R b9 are each independently 1-6 Fluorine-substituted alkyl, C 1-6 Fluorine-substituted alkoxy, C 6-12 Fluorine-substituted aryl, C 2-12 Fluorine-substituted acyl, or C 6-12 Fluorine-substituted alkoxyaryl, preferably C 2-6 The term "fluorine-substituted alkyl" as used herein means that some or all of the hydrogen atoms present in the alkyl moiety are substituted with fluorine atoms, and more preferably all of the hydrogen atoms are substituted with fluorine atoms. The Two R's b9 may be bonded to each other to form a fluorine-substituted heterocyclic structure. The heterocyclic structure is preferably a saturated ring. The heterocyclic structure is preferably a monocyclic structure having 5 to 8 rings including N and S; more preferably a 5-membered or 6-membered ring; and even more preferably a 6-membered ring.

[0060] R b9 The alkyl portion of R is preferably methyl, ethyl, propyl, butyl or pentyl (more preferably methyl, ethyl or butyl; even more preferably butyl). b9 The alkyl portion of is preferably straight chain.

[0061] Specific examples of formula (BA3) include the following. [ka]

[0062] Equation (BA4) is as follows: [ka] Where: R b10 is hydrogen, C 1-6 Alkyl, C 1-6 alkoxy, or hydroxy; L b2 is carbonyl, oxy or carbonyloxy, Y b are each independently hydrogen or fluorine, nb4 is an integer from 0 to 10, and nb5 is an integer from 0 to 21.

[0063] R b10 is preferably hydrogen, methyl, ethyl, methoxy, or hydroxy (more preferably hydrogen or hydroxy). L b2 is preferably carbonyl or carbonyloxy (more preferably carbonyl). Preferably Y b At least one of these is fluorine. nb4 is preferably 0. nb5 is preferably 4, 5 or 6.

[0064] Specific examples of formula (BA4) include the following. [ka]

[0065] Equation (BA5) is as follows: [ka] Where: L b3 is a single bond or C 1-3 is a divalent alkylene of X b is an aromatic ring, a heteroaromatic ring, or an alicyclic ring, and these rings are each independently selected from the group consisting of one or more of nitro, C1-10 Alkyl, or C 1-6 It may be substituted by fluorine-substituted alkyl, and a ring atom in the alicyclic ring may be replaced by carbonyl.

[0066] L b3 is preferably a single bond, methylene, or ethylene (more preferably a single bond). X b is preferably a benzene ring or a pyridine ring optionally substituted by methyl or nitro (more preferably a methyl-substituted benzene ring).

[0067] Specific examples of formula (BA5) include the following. [ka]

[0068] Formula (B-2) is the following, and a non-ionic photoacid generator containing this structure is preferred. [ka] Specific examples of the compound containing the formula (B-2) include the following. [ka]

[0069] The molecular weight of the photoacid generator (B) is preferably 400 to 2,500 (more preferably 400 to 1,500).

[0070] The content of the photoacid generator (B) is preferably 0.05 to 10 mass % (more preferably 0.10 to 2 mass %; even more preferably 0.2 to 1 mass %; still more preferably 0.40 to 0.80 mass %) based on the composition. The content of the photoacid generator (B) is preferably 0.1 to 20 mass % (more preferably 0.5 to 10 mass %; even more preferably 1.0 to 5.0 mass %; still more preferably 2.0 to 4.5 mass %) based on the polymer (A).

[0071] Solvent (C) The composition according to the present invention comprises a solvent (C). The solvent is not particularly limited as long as it can dissolve each of the components to be blended. The solvent (C) is preferably water, a hydrocarbon solvent, an ether solvent, an ester solvent, an alcohol solvent, a ketone solvent, or any combination thereof. Specific examples of the solvent include water, n-pentane, i-pentane, n-hexane, i-hexane, n-heptane, i-heptane, 2,2,4-trimethylpentane, n-octane, i-octane, cyclohexane, methylcyclohexane, benzene, toluene, xylene, ethylbenzene, trimethylbenzene, methylethylbenzene, n-propylbenzene, i-propylbenzene, diethylbenzene, i-butylbenzene, triethylbenzene, di-i-propylbenzene, n-amylnaphthalene, trimethylbenzene, methanol, ethanol, n-Propanol, i-Propanol, n-Butanol, i-Butanol, sec-Butanol, t-Butanol, n-Pentanol, i-Pentanol, 2-Methylbutanol, sec-Pentanol, t-Pentanol, 3-Methoxybutanol, n-Hexanol, 2-Methylpentanol, sec-Hexanol, 2-Ethylbutanol, sec-Heptanol, Heptanol-3, n-Octanol, 2-Ethylhexanol, sec-Octanol, n-Nonylalcohol, 2,6-Dimethylheptanol-4, n-Decanol, sec-U nonyl alcohol, trimethylnonyl alcohol, sec-tetradecyl alcohol, sec-heptadecyl alcohol, phenol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol, phenylmethylcarbinol, diacetone alcohol, cresol, ethylene glycol, propylene glycol, 1,3-butylene glycol, pentanediol-2,4, 2-methylpentanediol-2,4, hexanediol-2,5, heptanediol-2,4, 2-ethylhexanediol All-1,3, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, glycerin, acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, diethyl ketone, methyl-i-butyl ketone, methyl-n-pentyl ketone, ethyl-n-butyl ketone, methyl-n-hexyl ketone, di-i-butyl ketone, trimethylnonanone, cyclohexanone, cyclopentanone, methylcyclohexanone, 2,4-pentanedione, acetonylacetone, diacetone alcohol,Acetophenone, Fenchone, Ethyl Ether, i-Propyl Ether, n-Butyl Ether (Di-n-Butyl Ether, DBE), n-Hexyl Ether, 2-Ethylhexyl Ether, Ethylene Oxide, 1,2-Propylene Oxide, Dioxolane, 4-Methyldioxolane, Dioxane, Dimethyldioxane, Ethylene Glycol Monomethyl Ether, Ethylene Glycol Monoethyl Ether, Ethylene Glycol Diethyl Ether, Ethylene Glycol Mono-n-Butyl Ether, Ethylene Glycol Mono-n-Hexyl Ether, Ethylene Glycol Monophenyl Ether, Ethylene Glycol Mono-2-Ethylbutyl Ether, Ethylene Glycol Dibutyl Ether, Diethylene Glycol Monomethyl Ether, Diethylene Glycol Monoethyl Ether, Diethylene Glycol Diethyl Ether, Diethylene Glycol Mono-n-Butyl Ether, Diethylene Glycol Di-n-Butyl Ether, Diethylene Glycol Mono-n-Hexyl Ether, Ethoxytriglycol, Tetraethylene Glycol Di-n-Butyl Ether, Propylene Glycol Monomethyl Ether (PGME), propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monomethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, diethyl carbonate, methyl acetate, ethyl acetate, gamma-butyrolactone, gamma-valerolactone, n-propyl acetate, i-propyl acetate, n-butyl acetate (normal butyl acetate, nBA), i-butyl acetate, sec-butyl acetate, n-pentyl acetate, sec-pentyl acetate, 3-methoxybutyl acetate, methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methylcyclohexyl acetate, n-nonyl acetate, methyl acetoacetate, ethyl acetoacetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate,Diethylene glycol monoethyl ether acetate, diethylene glycol mono-n-butyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, glycol diacetate, methoxytriglycol acetate, ethyl propionate, n-butyl propionate, i-amyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate (EL), n-butyl lactate, n-amyl lactate Mil, diethyl malonate, dimethyl phthalate, diethyl phthalate, propylene glycol 1-monomethyl ether 2-acetate (PGMEA), propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, N-methylformamide, N,N-dimethylformamide, N,N-diethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, N-methylpropionamide, N-methylpyrrolidone, dimethyl sulfide, diethyl sulfide, thiophene, tetrahydrothiophene, dimethyl sulfoxide, sulfolane, and 1,3-propane sultone. These solvents can be used alone or in combination of two or more. The solvent (C) is preferably PGME, PGMEA, EL, nBA, DBE, or a mixture of any of these (more preferably PGME, PGMEA, nBA, DBE, or a mixture of any of these; even more preferably PGME, PGMEA, or a mixture of these; even more preferably a mixture of PGME and PGMEA). When two types are mixed, the mass ratio of the first solvent to the second solvent is preferably 95:5 to 5:95 (more preferably 90:10 to 10:90, even more preferably 80:20 to 20:80). When three types are mixed, the mass ratio of the first solvent to the sum of the three types is 30 to 90% (more preferably 50 to 80%; even more preferably 60 to 70%), the mass ratio of the second solvent to the sum of the three types is 10 to 50% (more preferably 20 to 40%), and the mass ratio of the third solvent to the sum of the three types is 5 to 40% (more preferably 5 to 20%; even more preferably 5 to 15%).

[0072] In relation to other layers or films, the solvent (C) may not substantially contain water. For example, the amount of water in the entire solvent (C) is preferably 0.1% by mass or less (more preferably 0.01% by mass or less, and even more preferably 0.001% by mass or less). In another preferred embodiment, the solvent (C) does not contain water (0% by mass).

[0073] The content of the solvent (C) is preferably 80 to 98.95 mass% (more preferably 80 to 95 mass%; further preferably 80 to 90 mass%) based on the composition. By increasing or decreasing the amount of the solvent in the entire composition, the film thickness after formation can be controlled.

[0074] Dissolution rate modifier (D) The composition according to the present invention may contain a small amount of dissolution rate modifier (D) represented by formula (D-1). The dissolution rate modifier has the function of adjusting the solubility of the polymer in the developer. Without being bound by theory, the composition according to the present invention can obtain a resolution suitable for lift-off or form a pattern shape even if it contains almost no dissolution rate modifier. It is not essential that the composition of the present invention contains a dissolution rate modifier. Equation (D-1) is as follows. [ka] (In the formula, Each nd1 is independently 1, 2 or 3 (preferably 1 or 2; more preferably 1). Each nd2 is independently 0, 1, 2 or 3 (preferably 0, 2 or 3). R d1 are each independently 1-7 It is alkyl (preferably methyl, ethyl, or cyclohexyl; more preferably methyl or cyclohexyl). L d is C 1-15 a divalent alkylene of the formula (which may be substituted by an aryl which may be hydroxy-substituted), d may form a ring with a substituent other than C 2-12 divalent alkylene; more preferably C 2-7 (divalent alkylene).

[0075] (D) Specific examples of dissolution rate modifiers are as follows: [ka]

[0076] The content of the dissolution rate regulator (D) is 0 to 1.0 part by mass (preferably 0 to 0.1% by mass; more preferably 0 to 0.01% by mass; and even more preferably 0.00% by mass) relative to 100 parts by mass of the polymer (A). In one preferred embodiment of the present invention, no dissolution rate regulator (D) is contained.

[0077] Basic Compounds (E) The composition according to the present invention may further contain a basic compound (E). The basic compound has the effect of suppressing the diffusion of the acid generated in the exposed area and the effect of suppressing the deactivation of the acid on the resist film surface due to amine components contained in the air.

[0078] The basic compound (E) is preferably 1-16 Primary aliphatic amine compounds, C 2-32 Secondary aliphatic amine compounds, C 3-48 Tertiary aliphatic amine compounds, C 6-30 Aromatic amine compounds of C 5-30 Examples of the heterocyclic amine compounds include the following:

[0079] Specific examples of the basic compound (E) include ethylamine, n-octylamine, n-heptylamine, ethylenediamine, triethylamine, tri-n-octylamine, diethylamine, triethanolamine, tris[2-(2-methoxyethoxy)ethyl]amine, 1,8-diazabicyclo[5.4.0]undecene-7, 1,5-diazabicyclo[4.3.0]nonene-5, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, and 1,5,7-triazabicyclo[4.4.0]dec-5-ene.

[0080] The base dissociation constant pKb(H2O) of the basic compound (E) is preferably -12 to 5 (more preferably 1 to 4).

[0081] The molecular weight of the basic compound (E) is preferably 20 to 500 (more preferably 60 to 400).

[0082] The content of the basic compound (E) is preferably 0 to 1 mass % (more preferably 0.01 to 0.5 mass %; further preferably 0.02 to 0.1 mass %) based on the composition. In one preferred embodiment, the composition does not contain the basic compound (E). The content of the basic compound (E) is preferably 0.1 to 20 mass % (more preferably 0.1 to 5 mass %; even more preferably 0.1 to 1.0 mass %; still more preferably 0.1 to 0.5 mass %) based on the polymer (A).

[0083] Surfactant (F) The composition according to the present invention may further include a surfactant (F). By including a surfactant, the coating property can be improved. Examples of surfactants that can be used in the present invention include (I) anionic surfactants, (II) cationic surfactants, and (III) nonionic surfactants, and more specifically, (I) alkylsulfonates, alkylbenzenesulfonic acids, and alkylbenzenesulfonates, (II) laurylpyridinium chloride, and laurylmethylammonium chloride, and (III) polyoxyethylene octyl ethers, polyoxyethylene lauryl ethers, polyoxyethylene acetylenic glycol ethers, fluorine-containing surfactants (e.g., Fluorad (3M), Megafac (DIC), Sulfuron (Asahi Glass), and organic siloxane surfactants (e.g., KF-53, KP341 (Shin-Etsu Chemical)).

[0084] These surfactants can be used alone or in combination of two or more. The content of the surfactant (F) is preferably 0 to 3 mass % (more preferably 0.005 to 0.5 mass %; further preferably 0.01 to 0.2 mass %) based on the composition. The content of the surfactant (F) is preferably 0.01 to 5 mass % (more preferably 0.01 to 1 mass %; further preferably 0.05 to 0.5 mass %) based on the polymer (A).

[0085] Polymer (G) The composition according to the present invention may further contain a polymer (G) different from the polymer (A). The polymer (G) is different from the polymer (A). The polymer (G) may be, for example, a novolac polymer, which is obtained, for example, by a condensation reaction between a phenol and formaldehyde. The cLogP of the polymer (G) is preferably 2.76 to 3.35 (more preferably 3.00 to 3.30; further preferably 3.15 to 3.25).

[0086] Preferably, the total mass Ma of the polymers (A) and the total mass Mg of the polymers (G) in the composition satisfy the following: Ma / (Ma+Mg) is preferably greater than 0 and equal to or less than 100% (more preferably 50 to 100%; even more preferably 80 to 100%; still more preferably 95 to 100%). Mg / (Ma+Mg) is preferably 0 or more and less than 70% (more preferably 0 to 50%; even more preferably 0 to 20%; still more preferably 0 to 5%). 0 <Ma / (Ma+Mg)≦100%、および0≦Mg / (Ma+Mg)<70% It is preferable that Mg / (Ma+Mg)=0.0% is also a preferable embodiment of the present invention.

[0087] The content of polymer (G) is preferably 0 to 10 mass% (more preferably 0 to 5 mass%; further preferably 0 to 1 mass%) based on the composition. A preferred embodiment of the present invention is one in which the composition of the present invention does not contain any polymer other than polymer (A).

[0088] Crosslinker (H) The composition according to the present invention may further contain a crosslinking agent (H). Without being bound by theory, the present invention is a positive resist composition, so there is no need to crosslink the exposed area, and film formation can be achieved even without a crosslinking agent, so a crosslinking agent is not essential. As an embodiment of the present invention, it is preferable that the composition contains a small amount of crosslinking agent. The content of the crosslinking agent (H) is preferably 0 to 1.0 part by mass (more preferably 0 to 0.1 part by mass) relative to 100 parts by mass of the polymer (A). In a preferred embodiment of the present invention, the composition does not contain a crosslinking agent (H).

[0089] Plasticizers (I) The composition according to the invention may further comprise a plasticizer (I). By including a plasticizer, film cracking during the formation of a thick film can be suppressed. Examples of the plasticizer include an alkali-soluble vinyl polymer and an acid-dissociable group-containing vinyl polymer. More specifically, examples of the plasticizer include polyvinyl chloride, polystyrene, polyhydroxystyrene, polyvinyl acetate, polyvinyl benzoate, polyvinyl ether, polyvinyl butyral, polyvinyl alcohol, polyether ester, polyvinyl pyrrolidone, polyacrylic acid, polymethacrylic acid, polyacrylic acid ester, maleic acid polyimide, polyacrylamide, polyacrylonitrile, polyvinyl phenol, novolac, and copolymers thereof, and more preferably polyvinyl ether, polyvinyl butyral, and polyether ester.

[0090] The content of the plasticizer (I) is preferably 0 to 1 part by mass (more preferably 0 to 0.1 part by mass) relative to 100 parts by mass of the polymer (A). In one preferred embodiment of the present invention, the composition does not contain a plasticizer (I).

[0091] Additives (J) The composition according to the present invention may further include an additive (J), which is at least one selected from the group consisting of an acid, a photoreaction quencher, a surface smoothing agent, a dye, a contrast enhancing agent, an acid, a radical generator, a substrate adhesion enhancing agent, and an antifoaming agent. The content of the additive (J) (when there are multiple additives, the sum of the additives) is preferably 0 to 5 mass% (more preferably 0 to 3 mass%; further preferably 0 to 1 mass%) based on the composition. In one embodiment of the present invention, the composition according to the present invention does not contain any additive (J) (0 mass%).

[0092] The acid can be used to adjust the pH value of the composition or to improve the solubility of additive components. The acid used is not particularly limited, but examples thereof include formic acid, acetic acid, propionic acid, benzoic acid, phthalic acid, salicylic acid, lactic acid, malic acid, citric acid, oxalic acid, malonic acid, succinic acid, fumaric acid, maleic acid, aconitic acid, glutaric acid, adipic acid, p-toluenesulfonic acid, camphorsulfonic acid, hydrates of any of these, and combinations thereof. The content of the acid is preferably 0.005 to 0.1% by mass (more preferably 0.01 to 0.1% by mass) based on the composition.

[0093] The photoreactive quencher can be used to suppress inactivation of the acid on the resist film surface due to components such as amines contained in the air, and is different from the photoacid generator (B). In a preferred embodiment of the present invention, the acid that acts directly on the polymer (A) is not a photoreactive quencher but an acid released from the photoacid generator (B). The photoreactive quencher releases an acid upon exposure to light, and the acid preferably has an acid dissociation constant pKa(H2O) of 1.5 to 8 (more preferably 1.5 to 5). The photoreactive quencher is composed of a cation and an anion, and specific examples of the cation and anion include the following. [ka]

[0094] The composition according to the present invention is used in a lithography process to improve heat resistance, improve resolution, form an inverse tapered shape, and / or reduce standing waves. Preferably, the composition according to the present invention is used in a lithography process to improve resolution.

[0095] <Method of manufacturing resist pattern> The method for producing a resist pattern according to the present invention comprises the following steps: (1) applying a composition according to the present invention over a substrate; (2) heating the composition to form a resist layer; (3) exposing the resist layer; (4) post-exposure baking of the resist layer; and (5) Developing the resist layer. For clarity, numbers in parentheses indicate the order, e.g., step (1) is performed before step (2).

[0096] An embodiment of the manufacturing method according to the present invention will now be described. The composition according to the present invention is applied above a substrate (e.g., a silicon / silicon dioxide-coated substrate, a silicon nitride substrate, a silicon wafer substrate, a glass substrate, an ITO substrate, etc.) by a suitable method. Here, in the present invention, above includes the case where it is formed directly above and the case where it is formed via another layer. For example, a planarizing film or a resist underlayer film may be formed directly above the substrate, and the composition according to the present invention may be applied directly above it. An example of the resist underlayer film is a BARC layer. The application method is not particularly limited, and examples include a method of coating with a spinner or a coater. After coating, the film according to the present invention is formed by heating. The heating in (2) is performed, for example, by a hot plate. The heating temperature is preferably 100 to 250°C (more preferably 100 to 200°C; even more preferably 100 to 160°C). The temperature here is the heating atmosphere, for example, the heating surface temperature of a hot plate. The heating time is preferably 30 to 300 seconds (more preferably 30 to 120 seconds; even more preferably 45 to 90 seconds). The heating is preferably performed in air or nitrogen gas atmosphere. The thickness of the resist layer formed by the manufacturing method according to the present invention is preferably 50 to 1,500 nm.

[0097] The resist layer is exposed through a predetermined mask. The wavelength of light used for exposure is not particularly limited, but it is preferable to use light with a wavelength of 13.5 to 248 nm. Specifically, KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), extreme ultraviolet light (wavelength 13.5 nm), etc. can be used, and KrF excimer laser is preferable. These wavelengths are allowed within a range of ±1%.

[0098] After the exposure, a post exposure bake (hereinafter sometimes referred to as PEB) is carried out. The heating in (4) is carried out, for example, by using a hot plate. The temperature of the post exposure bake is preferably 80 to 160°C (more preferably 105 to 115°C), and the heating time is preferably 30 to 600 seconds (more preferably 45 to 120 seconds; even more preferably 45 to 90 seconds). The heating is preferably carried out in air or a nitrogen gas atmosphere.

[0099] After PEB, development is performed using a developer. As the development method, a method conventionally used for developing photoresists, such as a paddle development method, an immersion development method, and a swing immersion development method, can be used. As the developer, an aqueous solution containing an inorganic alkali such as sodium hydroxide, potassium hydroxide, sodium carbonate, or sodium silicate, an organic amine such as ammonia, ethylamine, propylamine, diethylamine, diethylaminoethanol, or triethylamine, or a quaternary amine such as tetramethylammonium hydroxide (TMAH), is used, and preferably a 2.38 mass % TMAH aqueous solution. A surfactant can also be added to the developer. The temperature of the developer is preferably 5 to 50°C (more preferably 25 to 40°C), and the development time is preferably 10 to 300 seconds (more preferably 45 to 90 seconds). After development, water washing or rinsing treatment can be performed as necessary. Since a positive resist composition is used, the exposed portion is removed by development to form a resist pattern. This resist pattern can also be further fined by using, for example, a shrink material.

[0100] The film thickness of the resist pattern formed is preferably 50 to 1,500 nm. The shape of the resist pattern to be formed is not particularly limited as long as it is a shape suitable for lift-off, but a reverse tapered shape is preferable.

[0101] In the present invention, the reverse taper shape means that, when a resist pattern 12 is formed on a substrate 11 as shown in the cross-sectional view of FIG. 1(A), the angle between the straight line (taper line) connecting the opening point (boundary between the resist surface and the side surface of the resist pattern) 13 and the bottom point (boundary between the substrate surface and the side surface of the resist pattern) 14 and the substrate surface is greater than 90 degrees, and the resist pattern does not substantially protrude beyond the taper line, i.e., the resist pattern is not substantially thick. Here, this angle is called the taper angle 15. Such a resist pattern is called a reverse taper shape resist pattern 12. In the present invention, the reverse taper shape does not only mean a reverse truncated cone shape, but also includes a case where the line width of a line pattern at the surface is wider than the line width near the substrate. The inverse tapered resist pattern according to the present invention includes a case where the resist pattern is hollowed out inward from the straight line (taper line 24) connecting the opening point 22 and the bottom point 23, that is, the resist pattern is thin, as shown in the cross-sectional view of FIG. 1(B). The taper angle here is the taper angle 25. Such a resist pattern is called an overhanging resist pattern 21. A straight line is drawn parallel to the substrate surface at a height 27 that is half the length of the resist pattern's film thickness 26 from the substrate, and the distance between the intersection of the straight line with the resist pattern and the intersection of the taper line is called the bite width 28. Similarly, the distance between the intersection of the straight line with the resist pattern and the intersection of the straight line with the straight line drawn perpendicular to the substrate from the opening point is called the taper width 29. FIG. 1(B) shows a case where the bite width / taper width is greater than 0, and FIG. 1(A) shows a case where the bite width / taper width is 0. An overhanging shape is preferable because a stripping solution tends to easily penetrate into the resist when the resist is stripped after metal deposition. As a modified example of the overhang shape, the end of the resist pattern 31 may be rounded as shown in Fig. 1(C). In this case, the opening point 32 is the boundary between the resist surface and the side of the resist pattern, and is assumed to be a plane of the resist surface parallel to the bottom surface, and is the point where the resist pattern separates from the plane. The bottom point 33 is the boundary between the substrate surface and the side of the resist pattern. The straight line connecting the opening point 32 and the bottom point 33 is the taper line 34, and the taper angle here is taper angle 35. The area inside the taper line but not the resist pattern is S in 36, and the area of ​​the resist pattern outside the taper line is S out 37. In the case of multiple areas, the sum of the areas is used. S out / (S in +S out ) is preferably 0 to 0.45 (more preferably 0 to 0.1; even more preferably 0 to 0.05; even more preferably 0 to 0.01). out / (S in +S out ) is advantageous in that the stripping solution can easily penetrate into the side walls of the resist even if a thick metal is deposited on the resist pattern. (S in -S out ) / (S in +S out ) is preferably 0 to 1 (more preferably 0.55 to 1; even more preferably 0.9 to 1; even more preferably 0.99 to 1). in -S out ) / (S in +S out In a preferred embodiment of the present invention, the formula (S in -S out ) / (S in +S out ) is large, the resist pattern as a whole will have a shape recessed inward from the taper line, which is advantageous in that the stripping solution can easily penetrate into the resist sidewall even if a thick metal is evaporated onto the resist pattern. In the cases of the shapes in Figure 1(A) and (B), out / (S in +S out )=0, and both (S in -S out ) / (S in +S out )=1.

[0102] In a preferred embodiment of the present invention, the width of the upper portion of the resist pattern is Wt and the width of the lower portion of the resist pattern is Wb, It is preferable that −50 nm≦(Wt−Wb), more preferable that 0 nm<(Wt−Wb), and further preferable that 50 nm<(Wt−Wb). When a resist pattern having a reverse tapered shape can be formed, Wt>Wb. It is preferable to measure under the same conditions as those in the Examples described below as much as possible for comparing these numerical values. For example, it is preferable to form a film with a thickness of 900 nm and then form a resist pattern with a 1:1 trench of 500 nm for comparison. It is preferable that −10%≦(Wt−Wb) / Wt, it is more preferable that 0%<(Wt−Wb) / Wt, and it is even more preferable that 10%<(Wt−Wb) / Wt.

[0103] moreover, (6) depositing metal above the substrate using the resist pattern as a mask; and (7) Removing the resist pattern with a stripping solution The metal pattern can be produced by a method comprising the steps of: Using the resist pattern as a mask, a metal such as gold or copper (or a metal oxide) is evaporated above the substrate. In addition to evaporation, sputtering may also be used. Thereafter, the resist pattern is removed together with the metal formed thereon using a stripping solution to form a metal pattern. The stripping solution is not particularly limited as long as it is used as a resist stripping solution, but for example, N-methylpyrrolidone (NMP), acetone, and an alkaline solution are used. Since the resist pattern according to the present invention has an inverse tapered shape, the metal on the resist pattern and the metal formed in the part where the resist pattern is not formed are separated from each other, so that the resist pattern can be easily stripped. In addition, the film thickness of the formed metal pattern can be made thick, and a metal pattern having a film thickness of preferably 10 to 1500 nm (more preferably 50 to 800 nm; even more preferably 100 to 600 nm) is formed. Without being bound by theory, it is considered that the resist pattern formed from the present composition has good heat resistance and is therefore suitable for these lift-off processes.

[0104] As another embodiment of the present invention, the resist pattern formed up to the step (5) can be used as a mask to pattern various substrates that serve as the base. The substrate can be processed directly using the resist pattern as a mask, or can be processed via an intermediate layer. For example, the resist underlayer film can be patterned using the resist pattern as a mask, and the substrate can be patterned using the resist underlayer film pattern as a mask. A known method can be used for processing, such as a dry etching method, a wet etching method, an ion implantation method, or a metal plating method. It is also possible to wire electrodes, etc., on the patterned substrate.

[0105] Thereafter, if necessary, further processing such as forming wiring on the processed substrate is performed to form a device. For these further processing, known methods can be applied. Examples of the device include a semiconductor element, a liquid crystal display element, an organic EL display element, a plasma display element, and a solar cell element. The device is preferably a semiconductor element. EXAMPLES

[0106] The present invention will be described below with reference to various examples. However, the present invention is not limited to these examples.

[0107] Preparation of Composition 1 A mixture solvent with a mass ratio of PGMEA:PGME=30:70 is prepared. To 100 parts by mass of A1 as the polymer (A), 2.6 parts by mass of B-1 as the photoacid generator (B), 0.32 parts by mass of E as the base compound (E), and 0.1 parts by mass of F-1 as the surfactant (F) are added to the mixture solvent. The amount added is adjusted so that the solid component concentration is 16.5% by mass. The solid component concentration is calculated as (mass of all components excluding the solvent / mass of the entire composition). This is stirred at room temperature for 30 minutes. It is visually confirmed that the solute has dissolved. This is filtered through a 0.05 μm filter. Composition 1 is obtained in this way. The composition is shown in Table 1. The components used are as follows: A1: Hydroxystyrene:styrene:t-butyl acrylate copolymer, molar ratio 6:2:2, respectively, cLogP=2.79, Mw12,000. The above ratios indicate the constituent ratios of the respective repeating units. The same applies below. [ka] 6:2:2 B-1: [ka] E: tris[2-(2-methoxyethoxy)ethyl]amine, F-1: KP341, Shin-Etsu Chemical Co., Ltd.

[0108] Preparation of Compositions 2 to 10 and Comparative Composition 1 The components and amounts are changed as shown in Table 1, and the same procedure as in "Preparation of Composition 1" is carried out to obtain Compositions 2 to 10 and Comparative Composition 1. In the following tables, the amount of each component is shown in parts by mass. In the comparative composition 1, A1 as the polymer (A) and G as the polymer (G) are used in a mass ratio of 1:1 to form a polymer. The components used are as follows: A2: [ka] 6:2:2, cLogP=2.98, Mw12,000, A3: [ka] 6:2:2, cLogP=3.30, Mw12,000, G: [ka] 4:4:2, cLogP=3.21, Mw5,000, B-2: [ka] B-3: [ka] B-4: [ka] J: Camphorsulfonic acid [ka] I: Lutonal, BASF [ka] D:TPPA [ka] F-2: KF-53, Shin-Etsu Chemical Co., Ltd. [Table 1]

[0109] <Formation of resist pattern using compositions 1 to 10> The surface of an 8-inch silicon wafer is treated with HMDS at 90°C for 60 seconds. Each composition is dropped onto the wafer and spin-coated. The wafer is baked on a hot plate at 110°C for 60 seconds to form a resist film. The thickness of the resist film at this point is measured using an optical interference film thickness measurement device M-1210 (SCREEN), and is 900 nm for each. The resist film is exposed using a KrF stepper (FPA3000-EX5, CANON). The mask pattern used is dense line (line:space=1:1, line=500 nm). The wafer is then baked (PEB) on a hot plate at 110°C for 60 seconds. The wafer is paddle-developed with a 2.38% by mass TMAH aqueous solution for 60 seconds, washed with DIW, and spin-dried at 1,000 rpm. This results in a resist pattern with a line width of 500 nm. The line width is measured at the top of the resist pattern. Figure 2 shows a schematic vertical cross-sectional shape of this pattern. A resist pattern 42 is formed on a substrate 41. The three figures show the case where the width of the upper part 43 of the resist pattern is the same, and the width of the lower part 44 of the resist pattern is different. The optimum exposure dose is the exposure dose that forms a pattern with a line width of 500 nm at the top of the resist pattern when the resist patterns are formed using Compositions 1 to 10 and Comparative Composition 1. Using this optimum exposure dose, the resolution, dimensional difference, and heat resistance are evaluated as described below.

[0110] <Comparative Composition 1: Formation of Resist Pattern> The same operation as in "Formation of resist pattern using compositions 1 to 10" was carried out, except that comparative composition 1 was used and exposure was performed using an i-line stepper (NSR-2205i11D, Nikon) instead of a KrF stepper (FPA3000-EX5). This resulted in a resist pattern with a line width of 500 nm. The line width was measured at the top of the pattern.

[0111] <Examples 101 to 110 and Comparative Example 101: Evaluation of Resolution> A mask pattern with line and space widths of 250-500 nm, and a line:space ratio of 1:1, is used to expose at the optimum exposure dose using the pattern formation method described above. The minimum dimension (nm) of the top of the resist pattern that can be resolved when exposed at the optimum exposure dose is taken as the resolution. The dimension is measured as the length of the top of the pattern. If the pattern collapses or the space is crushed, it is treated as not being resolved. The smallest line width at which neither pattern collapse nor space crush is observed is adopted as the minimum dimension. The evaluation criteria are as follows: A: Less than 300 nm B: 300~400nm C: greater than 400 nm The results obtained are shown in Table 2. [Table 2]

[0112] <Examples 201 to 210: Evaluation of dimensional difference> A slice of a sample of a resist pattern with a line width of 500 nm is prepared, and the vertical cross section of the pattern is observed with a scanning electron microscope (SU8230, Hitachi High-Tech). The cross-sectional shape of the resist pattern is confirmed using the SU8230, and the dimensions of the top and bottom of the resist are measured. At this time, the dimension of the top of the resist pattern is Wt, and the dimension of the bottom is Wb. The evaluation criteria are as follows. A: 50 nm < (Wt-Wb) B: -50nm≦(Wt-Wb)≦+50nm C: (Wt-Wb) <-50 nm The results obtained are shown in Table 3. [Table 3]

[0113] <Examples 301 and 302, Comparative Example 301: Evaluation of heat resistance> Heat resistance is evaluated using the composition shown in Table 4. Wt is obtained from the cross-sectional shape of the resist pattern obtained in the above "evaluation of dimensional difference". This is called Initial Wt. Prepare another sample using a mask pattern with a line width of 500 nm and a space width of 500 nm (Line:Space=1:1). Additional heat is applied to this sample for 180 seconds using a hot plate under atmospheric conditions. The additional heat temperature is changed from 120°C to 160°C in increments of 10°C for each wafer. A vertical cross-section of the pattern is obtained using the SU8230 to obtain Wt. This is called the additional bake Wt. Obtain the heating temperature at which (Initial Wt)-(Additional bake Wt)≧100 nm. The evaluation criteria are as follows. A: 150℃ or higher B: greater than 120℃ and less than 150℃ C: Below 120℃ The results obtained are shown in Table 4. [Table 4] [Explanation of symbols]

[0114] 11. Substrate 12.Reverse tapered resist pattern 13. Aperture point 14. Bottom point 15. Taper angle 21. Overhanging resist pattern 22. Opening Point 23. Bottom point 24. Tapered line 25. Taper angle 26. Film thickness of resist pattern 27.Half the film thickness of the resist pattern 28.Bite width 29.Taper width 31. Resist pattern 32. Opening Point 33. Bottom point 34. Tapered line 35. Taper angle 36.S in 37.S out 41. Circuit Board 42. Resist Pattern 43. Upper part of resist pattern 44. Lower part of resist pattern

Claims

1. A positive lift-off resist composition comprising a polymer (A), a photoacid generator (B), and a solvent (C): where: The cLogP of the polymer (A) is 2.76 to 3.35; The polymer (A) comprises at least one of the repeating units represented by formulas (A-1) to (A-4), and The content of the dissolution rate modifier (D) is 0 to 1.0 part by mass relative to 100 parts by mass of the polymer (A), and the dissolution rate modifier (D) is represented by formula (D-1). 【Chemistry 1】 (where, R １１ , R ２１ , R ４１ and R ４５ are each independently C １－５ Alkyl (wherein —CH ２ - may be replaced by -O-; R １２ , R １３ , R １４ , R ２２ , R ２３ , R ２４ , R ３２ , R ３３ , R ３４ , R ４２ , R ４３ , and R ４４ are each independently hydrogen, C １－５ Alkyl, C １－５ alkoxy, or —COOH; p11 is 0 to 4, p15 is 1 to 2, and p11 + p15 ≦ 5; p21 is 0 to 5, p41 is 0 to 4, p45 is 1 to 2, and p41 + p45 ≦ 5; P ３１ is C ４－２０ alkyl (wherein part or all of the alkyl may form a ring, and part or all of the H in the alkyl may be substituted with halogen) 【Chemistry 2】 (In the formula, nd1 is independently 1, 2 or 3; nd2 is independently 0, 1, 2 or 3; R ｄ１ are each independently C １－７ is alkyl, L ｄ is C １－１５ a divalent alkylene of the formula (which may be substituted by an aryl which may be hydroxy-substituted), ｄ may form a ring with a substituent other than

2. The number of repeating units n of the repeating units represented by formulas (A-1), (A-2), (A-3) and (A-4) in the polymer (A) Ａ－１ , n Ａ－２ , n Ａ－３ , and n Ａ－４ but, n Ａ－１ / (n Ａ－１ +n Ａ－２ +n Ａ－３ +n Ａ－４ )=40~80%、 n Ａ－２ / (n Ａ－１ +n Ａ－２ +n Ａ－３ +n Ａ－４ )=0~40%、 n Ａ－３ / (n Ａ－１ +n Ａ－２ +n Ａ－３ +n Ａ－４ ) = 0 to 40%, or n Ａ－４ / (n Ａ－１ +n Ａ－２ +n Ａ－３ +n Ａ－４ 2. The composition according to claim 1, wherein: Preferably, the total number n of all repeating units contained in the polymer (A) is ｔｏｔａｌ Then, (n Ａ－１ +n Ａ－２ +n Ａ－３ +n Ａ－４ ) / n ｔｏｔａｌ = Meets 80 to 100%.

3. The composition according to claim 1 or 2, wherein the photoacid generator (B) is represented by formula (B-1) or comprises a structure of formula (B-2): B ｎ＋ Cation B ｎ－ Anion (B-1) where: B ｎ＋ The cation is a cation represented by formula (BC1), a cation represented by formula (BC2), a cation represented by formula (BC3), or a cation represented by formula (BC4), and B ｎ＋ the cation as a whole is n-valent, n being 1 to 3; B ｎ－ The anion is an anion represented by formula (BA1), an anion represented by formula (BA2), an anion represented by formula (BA3), an anion represented by formula (BA4), or an anion represented by formula (BA5), and B ｎ－ The anion as a whole has a valency of n. 【Transformation 3】 (where, R ｂ１ are each independently C １－６ Alkyl, C １－６ Alkoxy, C ６－１２ Aryl, C ６－１２ arylthio, or C ６－１２ is aryloxy, nb1 is independently 0, 1, 2 or 3. 【Chemistry 4】 (where, R ｂ２ are each independently C １－６ Alkyl, C １－６ Alkoxy, or C ６－１２ is aryl, nb2 is independently 0, 1, 2 or 3. 【Transformation 5】 (where, R ｂ３ are each independently C １－６ Alkyl, C １－６ Alkoxy, or C ６－１２ is aryl, R ｂ４ are each independently C １－６ is alkyl, nb3 is independently 0, 1, 2 or 3. 【Transformation 6】 (where, L ｂ１ is a single bond or C １－３ wherein methylene in the alkylene may be replaced by carbonyl; R ｂ５ are each independently C １－６ Alkyl, C １－６ Alkoxy, or C ６－１２ is aryl, R ｂ６ are each independently C １－６ is alkyl, nb4 is independently 0, 1, 2 or 3. 【Transformation 7】 (where R ｂ７ are each independently C １－６ Fluorine-substituted alkyl, C １－６ fluorine-substituted alkoxy, or C １－６ alkyl) 【Transformation 8】 (where R ｂ８ is C １－１０ Fluorine-substituted alkyl, C １－６ Fluorine-substituted alkoxy, C ６－１２ Fluorine-substituted aryl, C ２－１２ Fluorine-substituted acyl, or C ６－１２ fluorine-substituted alkoxyaryl) 【Chemistry 9】 (where, R ｂ９ are each independently C １－６ Fluorine-substituted alkyl, C １－６ Fluorine-substituted alkoxy, C ６－１２ Fluorine-substituted aryl, C ２－１２ Fluorine-substituted acyl, or C ６－１２ fluorine-substituted alkoxyaryl, wherein two R ｂ９ may be bonded to each other to form a fluorine-substituted heterocyclic structure) 【Chemistry 10】 (where, R ｂ１０ is hydrogen, C １－６ Alkyl, C １－６ alkoxy, or hydroxy; L ｂ２ is carbonyl, oxy or carbonyloxy, Y ｂ are each independently hydrogen or fluorine, nb4 is an integer from 0 to 10, and nb5 is an integer from 0 to 21. 【Chemistry 11】 (where, L ｂ３ is a single bond or C １－３ is a divalent alkylene of X ｂ is an aromatic ring, a heteroaromatic ring, or an alicyclic ring, and these rings contain one or more of nitro, C １－１０ Alkyl, or C １－６ and a ring atom in the alicyclic ring may be replaced by a carbonyl. 【Chemistry 12】

4. The composition of claim 1 or 2, wherein the solvent (C) is water, a hydrocarbon solvent, an ether solvent, an ester solvent, an alcohol solvent, a ketone solvent, or any combination thereof.

5. The composition according to claim 1 or 2, further comprising a basic compound (E): Preferably, the basic compound (E) is C １－１６ Primary aliphatic amine compounds, C ２－３２ Secondary aliphatic amine compounds, C ３－４８ Tertiary aliphatic amine compounds, C ６－３０ Aromatic amine compounds, or C ５－３０ is a heterocyclic amine compound; or Preferably, the composition further comprises a surfactant (F).

6. The photoacid generator (B) exhibits an acid dissociation constant pKa (H ２ The composition according to claim 1 or 2, which releases an acid of -20 to 1.4: Preferably, the base dissociation constant pKb (H ２ O) is −12 to 5.

7. 3. The composition of claim 1 or 2, further comprising a polymer (G), wherein the polymer (G) is different from the polymer (A). Preferably, the cLogP of the polymer (G) is between 2.76 and 3.35; or Preferably, the total mass Ma of the polymer (A) and the total mass Mg of the polymer (G) in the composition are 0<Ma / (Ma+Mg)≦100%, and 0≦Mg / (Ma+Mg)<70%, Meet the following.

8. 3. The composition according to claim 1, wherein the thickness of a resist film formed from the composition is 50 to 1,500 nm.

9. The composition according to claim 1 or 2, further comprising a crosslinking agent (H), wherein the content of the crosslinking agent (H) is 0 to 1.0 part by mass per 100 parts by mass of the polymer (A): Preferably, the composition further comprises a plasticizer (I), and the content of the plasticizer (I) is 0 to 1.0 part by mass per 100 parts by mass of the polymer (A).

10. 3. The composition of claim 1 or 2, further comprising an additive (J), wherein the additive (J) is selected from at least one of the group consisting of an acid, a photoreaction quencher, a surface smoothing agent, a dye, a contrast enhancing agent, an acid, a radical generator, a substrate adhesion enhancing agent, and an antifoaming agent.

11. The content of the polymer (A) is 1 to 20% by mass based on the composition, The content of the photoacid generator (B) is 0.05 to 10% by mass based on the composition, and The composition according to claim 1 or 2, wherein the content of the solvent (C) is 80 to 98.95 mass% based on the composition: Preferably, the content of the basic compound (E) is 0 to 1 mass% based on the composition, Preferably, the content of the surfactant (F) is 0 to 3 mass% based on the composition, Preferably, the content of polymer (G) is 0 to 10% by weight, based on the composition; or Preferably, the content of the additive (J) is 0 to 5 mass % based on the composition.

12. 3. The composition according to claim 1, which is a thin film positive lift-off chemically amplified resist composition: Preferably, the composition is a thin film KrF positive lift-off chemically amplified resist composition.

13. 3. Use of the composition according to claim 1 or 2 for improving heat resistance, improving resolution, forming an inverse tapered shape, and / or reducing standing waves in a lithography process.

14. A method for producing a resist pattern, comprising the following steps: (1) applying the composition of claim 1 or 2 above a substrate; (2) heating the composition to form a resist layer; (3) exposing the resist layer; (4) post-exposure baking the resist layer; and (5) developing the resist layer;

15. 15. The method according to claim 14, wherein the resist pattern has a film thickness of 50 to 1,500 nm.

16. The method of claim 14, wherein the resist pattern has an inverse tapered shape.

17. A method for producing a metal pattern, comprising the steps of: Producing a resist pattern by the method of claim 14; (6) depositing metal above the substrate using the resist pattern as a mask; and (7) Removing the resist pattern with a stripping solution

18. The method according to claim 17, wherein the metal pattern has a film thickness of 10 to 1,500 nm.

19. A method for manufacturing a device comprising the method of claim 14.

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