Positive resist composition and method for producing a resist pattern using the same

Abstract

Provided is a positive resist composition capable of forming a pattern shape suitable for release. A positive resist composition comprises (A) a specific polymer, (B) an acid generator having an imide group, (C) a dissolution rate regulator, and (D) a solvent.

Description

Technical Field

[0001] The present invention relates to a positive resist composition for use in manufacturing semiconductor devices, semiconductor integrated circuits, etc., and a method for manufacturing a resist pattern using the positive resist composition. Background Art

[0002] In the manufacturing process of semiconductor devices, microfabrication is typically performed using photolithography techniques using photoresists. This involves forming a thin photoresist layer on a semiconductor substrate, such as a silicon wafer, and then covering the layer with a mask pattern corresponding to the target device. The layer is then exposed to active light, such as ultraviolet light, through the mask pattern. The exposed layer is then developed to create a photoresist pattern. The resulting photoresist pattern acts as a protective film for processing the substrate, creating fine irregularities corresponding to the pattern.

[0003] When using a positive-working resist composition, the exposed portion of the resist film formed by coating increases its alkali solubility due to the acid generated by exposure, dissolving in the developer, forming a pattern. Generally, the exposure light does not fully reach the lower portion of the resist film, suppressing acid generation in this lower portion. Furthermore, the generated acid is inactivated by the substrate in this lower portion of the resist film. Consequently, resist patterns formed using positive-working resist compositions tend to have a tapered shape (footer shape) (Patent Document 1).

[0004] A lift-off method is known in which a material such as metal is deposited on a resist pattern formed by vapor deposition or the like and the resist is removed with a solvent. The material on the resist pattern is removed, and only the metal or the like remains in the portion where the resist pattern is not formed.

[0005] To perform the lift-off method, a negative resist composition is often used because a resist pattern having an inverted tapered shape is preferred. In Patent Document 2, an attempt was made to form an inverted tapered shape for the purpose of manufacturing a partition wall of an EL display element, not a semiconductor, although the process was different and the required precision and sensitivity were also different. However, all the resist compositions used were negative, and only some of them achieved an inverted tapered shape.

[0006] On the other hand, research has been conducted on creating an undercut at the bottom of a resist pattern obtained from a positive resist composition to form a T-shape (for example, Patent Documents 3 to 5). These compositions require a special polymer or a novolac resin and a naphthoquinonediazide-based photosensitizer.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: International Publication No. 2011 / 102064

[0010] Patent Document 2: Japanese Patent Application Laid-Open No. 2005-148391A

[0011] Patent Document 3: Japanese Patent Application Laid-Open No. 2012-108415A

[0012] Patent Document 4: Japanese Patent Application Laid-Open No. 2001-235872A

[0013] Patent Document 5: Japanese Patent Application Laid-Open No. 8-69111A Summary of the Invention

[0014] Problems to be solved by the invention

[0015] The present inventors have determined that there are still several issues requiring improvement regarding resist compositions and their uses. These include, for example, the inability to form a resist pattern shape suitable for stripping; insufficient sensitivity of the resist composition; inability to achieve sufficient resolution; environmental influences during resist pattern production; inability to produce thick resist patterns; poor solubility of the solid component in solvents; inability of the stripper to penetrate the resist sidewalls when the deposited metal is thick in T-shaped resist patterns; low solubility in the stripper; inability to form resist patterns with high aspect ratios; numerous cracks in the resist film; numerous defects; and poor storage stability.

[0016] The present invention has been made to solve the above-mentioned problems, and provides a positive resist composition and a method for producing a resist pattern using the positive resist composition.

[0017] Means for solving problems

[0018] The positive thick film resist composition according to the present invention comprises:

[0019] (A) at least one polymer selected from polymer P and polymer Q,

[0020] The polymer P contains repeating units selected from the group consisting of formulae (P-1) to (P-4):

[0021]

[0022] (Where,

[0023] R p1 、R p3 、R p5 and R p8 Each independently is C 1-5 Alkyl, C 1-5 Alkoxy or -COOH,

[0024] Rp2 、R p4 and R p7 Each independently is C 1-5 Alkyl (here, -CH2- in the alkyl group can be replaced by -O-),

[0025] R p6 and R p9 Each independently is C 1-5 Alkyl (here, -CH2- in the alkyl group can be replaced by -O-),

[0026] x1 is 0 to 4, x2 is 1 to 2, where x1+x2≤5,

[0027] x3 is 0 to 5,

[0028] x4 is 1 to 2, x5 is 0 to 4, where x4+x5≤5),

[0029] Polymer Q comprises a repeating unit represented by formula (Q-1):

[0030]

[0031] (Where,

[0032] R q1 Each independently is C 1-5 alkyl,

[0033] y1 is 1 to 2, y2 is 0 to 3, where y1+y2≤4)

[0034] The total mass M of the polymer P in the composition is p and the total mass M of polymer Q q Satisfied: 0 <M p / (M p +M q )≤100%, and 0≤M q / (M p +M q )<70%;

[0035] (B) an acid generator having an imide group;

[0036] (C) a dissolution rate regulator, which is a compound comprising two or more phenol structures linked by a hydrocarbon group, wherein the hydrocarbon group may be substituted by an oxy group; and

[0037] (D) Solvent.

[0038] In addition, the method for manufacturing a resist pattern according to the present invention includes the following steps:

[0039] (1) applying the composition onto a substrate;

[0040] (2) heating the composition to form a resist layer;

[0041] (3) exposing the resist layer;

[0042] (4) heating the resist layer after exposure; and

[0043] (5) The resist layer is developed.

[0044] Effects of the Invention

[0045] By using the positive resist composition of the present invention, one or more of the following effects can be obtained.

[0046] A resist pattern shape suitable for stripping can be formed. The resist composition has sufficient sensitivity. Sufficient resolution can be achieved. Environmental impact during resist pattern production can be reduced. Thick-film resist patterns can be produced. The solid component has good solubility in solvents. Even if the deposited metal is thick, a resist pattern shape that allows the stripping solution to penetrate the resist sidewall can be obtained. The resist composition has high solubility in stripping solutions. A resist pattern with a high aspect ratio can be formed. Cracks in the resist film can be suppressed. The number of defects can be reduced. Good storage stability is achieved.

[0047] The advantages of the present invention are that the solubility in the stripping solution is high and the shape of the resist pattern is appropriate. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a conceptual cross-sectional view for explaining a resist pattern having an inverted tapered shape, a resist pattern having an overhang shape, and a modified example of a resist pattern having an overhang shape.

[0049] Figure 2 are a micrograph of a resist pattern having an inverted tapered shape and a schematic cross-sectional view thereof. DETAILED DESCRIPTION

[0050] definition

[0051] In this specification, unless otherwise specified, the definitions described in this “Definitions” paragraph shall apply.

[0052] The singular includes the plural, and “a” or “the” means “at least one.” In the present specification, some conceptual elements may be embodied in a plurality of types, and if the amount thereof (eg, mass % or mol %) is described, the amount means the sum of the plurality of types.

[0053] "And / or" includes all combinations of elements and also includes individual uses.

[0054] When “~” or “-” is used to indicate a numerical range, unless otherwise specified, both endpoints are included and the units are common. For example, 5 to 25 mol % means 5 mol % or more and 25 mol % or less.

[0055] “C x-y ”, “C x ~C y ” and “C x " etc. indicates the number of carbon atoms in a molecule or substituent. For example, C 1-6 The alkyl group represents an alkyl chain having 1 or more and 6 or less carbon atoms (such as methyl, ethyl, propyl, butyl, pentyl, and hexyl).

[0056] If a polymer has multiple repeating units, these repeating units are copolymerized. These copolymerizations can be alternating, random, block, graft, or a mixture thereof. When a polymer or resin is represented by a structural formula, n or m, etc., listed in parentheses, indicates the number of repeating units.

[0057] The temperature unit is Celsius. For example, 20 degrees means 20 degrees Celsius.

[0058] Hereinafter, embodiments of the present invention will be described in detail.

[0059] <Positive Resist Composition>

[0060] The positive resist composition according to the present invention (hereinafter, may be referred to as a composition) includes (A) a specific polymer, (B) an acid generator having an imide group, (C) a dissolution rate regulator, and (D) a solvent.

[0061] The viscosity of the composition according to the present invention is preferably 50 to 2,000 cP, more preferably 200 to 1,500 cP. Here, the viscosity is measured at 25°C using a capillary viscometer.

[0062] The composition according to the present invention is preferably a composition for forming a thick film resist. Here, in the present invention, thick film refers to a film thickness of 1 to 50 μm, preferably 5 to 15 μm, and thin film refers to a film thickness of less than 1 μm.

[0063] The composition according to the invention is preferably subsequently exposed to light having a wavelength of 190 to 440 nm, preferably 240 to 440 nm, more preferably 360 to 440 nm, even more preferably 365 nm.

[0064] The composition according to the present invention is preferably a positive resist composition that forms an inverse tapered shape. In the present invention, the "inverse tapered shape" will be described below.

[0065] The composition according to the present invention is preferably a positive resist stripping composition.

[0066] (A) Polymer

[0067] The (A) polymer includes polymer P, or a combination of polymer P and polymer Q. It goes without saying that when polymer P and polymer Q are included at the same time, they are not copolymerized.

[0068] [Polymer P]

[0069] The polymer P used in the present invention reacts with an acid to increase its solubility in alkaline aqueous solutions. This polymer has, for example, an acid group protected by a protecting group. When an acid is added from the outside, the protecting group is removed, and the solubility in alkaline aqueous solutions increases.

[0070] The polymer P comprises repeating units selected from the group consisting of formulae (P-1) to (P-4).

[0071]

[0072] (Where,

[0073] R p1 、R p3 、R p5 and R p8 Each independently is C 1-5 Alkyl, C 1-5 Alkoxy or -COOH,

[0074] R p2 、R p4 and R p7 Each independently is C 1-5 Alkyl (here, -CH2- in the alkyl group can be replaced by -O-),

[0075] R p6 and R p9 Each independently is C 1-5 Alkyl (here, -CH2- in the alkyl group can be replaced by -O-),

[0076] x1 is 0 to 4, x2 is 1 to 2, where x1+x2≤5,

[0077] x3 is 0 to 5,

[0078] x4 is 1 to 2, x5 is 0 to 4, where x4+x5≤5.

[0079] In one embodiment of the polymer P of the present invention, the polymer P contains only (P-1) as a structural unit, and the ratio of (P-1) with x2 = 1 to (P-1) with x2 = 2 is 1:1. In this case, x2 = 1.5. The same applies to polymers unless otherwise specified below.

[0080] In formula (P-1),

[0081] R p1 Preferably it is hydrogen or methyl, more preferably it is hydrogen. p2 It is preferably a methyl group, an ethyl group, a tert-butyl group or a methoxy group, and more preferably a methyl group or a tert-butyl group.

[0082] x2 is preferably 1 or 2, more preferably 1.

[0083] x1 is preferably 0, 1, 2 or 3, more preferably 0.

[0084] Specific examples of formula (P-1) are as follows.

[0085]

[0086] In formula (P-2),

[0087] R p3 It is preferably hydrogen or methyl, more preferably hydrogen. p4 It is preferably a methyl group, an ethyl group, a tert-butyl group or a methoxy group, and more preferably a methyl group or a tert-butyl group.

[0088] x3 is preferably 0, 1, 2 or 3, more preferably 0.

[0089] Specific examples of formula (P-2) are as follows.

[0090]

[0091] In formula (P-3),

[0092] R p5 It is preferably hydrogen or methyl, more preferably hydrogen. p6 Preferably, it is methyl, ethyl, propyl, tert-butyl, -CH(CH3)-OC2H5 or -CH(CH3)-O-CH3, more preferably methyl, butyl, -CH(CH3)-OC2H5 or -CH(CH3)-O-CH3, more preferably tert-butyl or -CH(CH3)-O-C2H5. p7 It is preferably a methyl group, an ethyl group, a tert-butyl group or a methoxy group, and more preferably a methyl group or a tert-butyl group.

[0093] x4 is preferably 1 or 2, more preferably 1.

[0094] x5 is preferably 0, 1, 2 or 3, more preferably 0.

[0095] Specific examples of formula (P-3) are as follows.

[0096]

[0097] In formula (P-4),

[0098] Rp8 It is preferably hydrogen or methyl, more preferably hydrogen. p9 It is preferably a methyl group, an ethyl group, a propyl group or a tert-butyl group, and more preferably a tert-butyl group.

[0099] Specific examples of formula (P-4) are as follows.

[0100]

[0101] These structural units are appropriately blended depending on the purpose, and therefore the blending ratio is not particularly limited. However, it is preferably blended in such a ratio that the solubility in an alkaline aqueous solution is increased by an acid.

[0102] Preferably, in polymer (A), the number of repeating units of formula (P-1), (P-2), (P-3) and (P-4) is n p1 、n p2 、n p3 and n p4 , preferably satisfying the following formula:

[0103] 30%≤n p1 / (n p1 +n p2 +n p3 +n p4 )≤90%,

[0104] 0%≤n p2 / ( p1 +n p2 +n p3 +n p4 )≤40%,

[0105] 0%≤n p3 / (n p1 +n p2 +n p3 +n p4 )≤40%, and

[0106] 0% ≤np4 / ( np1 + np2 + np3 + np4 )≤40%.

[0107] n p1 / (n p1 +n p2 +n p3 +n p4 ) is more preferably 40 to 80%, and even more preferably 40 to 70%.

[0108] n p2 / (n p1 +n p2 +np3 +n p4 ) is more preferably 0 to 30%, and further preferably 10 to 30%.

[0109] n p3 / (n p1 +n p2 +n p3 +n p4 ) is more preferably 0 to 30%, and even more preferably 10 to 30%. p3 / (n p1 +n p2 +n p3 +n p4 ) is 0% is also a preferred form.

[0110] n p4 / (n p1 +n p2 +n p3 +n p4 ) is more preferably 10 to 40%, and even more preferably 10 to 30%.

[0111] In addition, (n p3 +n p4 ) / (n p1 +n p2 +n p3 +n p4 ) is preferably 0 to 40%, more preferably 0 to 30%, and further preferably 10 to 30%. In the polymer P, it is also preferred that one of the repeating units of formula (P-3) and (P-4) is present and the other is absent.

[0112] The polymer P may also contain structural units other than (P-1) to (P-4). Here, the total number of all repeating units contained in the polymer P is n total Calculated by the following formula:

[0113] Preferably, 80%≤( np1 + np2 + np3 + np4 ) / n total ≤100%.

[0114] (n p1 +n p2 +n p3 +n p4 ) / n total More preferably, it is 90 to 100%, and even more preferably, it is 95 to 100%. (n p1 +n p2 +n p3 +n p4 ) / n total=100%, that is, containing no structural units other than (P-1) to (P-4), which is also a preferred embodiment of the present invention.

[0115] Specific examples of the polymer P are as follows.

[0116]

[0117] The mass average molecular weight (hereinafter sometimes referred to as Mw) of the polymer P is preferably 5,000 to 50,000, more preferably 7,000 to 30,000, and even more preferably 10,000 to 15,000.

[0118] In the present invention, Mw can be measured by gel permeation chromatography (GPC). In this measurement, a GPC column is preferably used at 40 degrees Celsius, with an elution solvent of tetrahydrofuran at 0.6 mL / min and monodisperse polystyrene as the standard. The same applies to the following.

[0119] [Polymer Q]

[0120] The polymer Q used in the present invention is a novolac polymer commonly used in photolithography, and is obtained, for example, by a condensation reaction of phenols and formaldehyde.

[0121] The polymer Q includes a repeating unit represented by the formula (Q-1).

[0122]

[0123] Where,

[0124] R q1 Each independently is C 1-5 alkyl,

[0125] y1 is 1 to 2,

[0126] y2 is 0 to 3, where y1+y2≤4.

[0127] y1 is preferably 1 or 2, more preferably 1.

[0128] y2 is preferably 0 to 2, more preferably 0.5 to 1.5.

[0129] The polymer Q preferably comprises repeating units selected from the group consisting of formulae (Q-1a) to (Q-1d).

[0130]

[0131] Number of repeating units N of (Q-1a) qa 、N number of repeating units of (Q-1b) qb 、N number of repeating units of (Q-1c) qc and the number of repeating units N of (Q-1d)qd Preferably the following formula is satisfied:

[0132] 30%≤N qa / (N qa +N qb +N qc +N qd )≤100%,

[0133] 0%≤N qb / (N qa +N qb +N qc +N qd )≤70%,

[0134] 0%≤N qc / (N qa +N qb +N qc +N qd )≤50%, and

[0135] 0%≤N qd / (N qa +N qb +N qc +N qd )≤70%.

[0136] N qa / (N qa +N qb +N qc +N qd ) is more preferably 30 to 80%, further preferably 30 to 70%, and even more preferably 40 to 60%.

[0137] N qb / (N qa +N qb +N qc +N qd ) is more preferably 10 to 60%, further preferably 20 to 50%, further preferably 30 to 50%.

[0138] N qc / (N qa +N qb +N qc +N qd ) is more preferably 0 to 40%, and even more preferably 10 to 30%. N qc / (N qa +N qb +N qc +N qd ) is 0% is also a preferred form.

[0139] N qd / (Nqa +N qb +N qc +N qd ) is more preferably 0 to 40%, and even more preferably 10 to 30%. N qd / (N qa +N qb +N qc +N qd In the polymer Q, it is also preferred that one of the repeating units of formula (Q-1c) and (Q-1d) is present, while the other is absent.

[0140] The polymer Q may also contain structural units other than (Q-1a) to (Q-1d). Here, the total number N of all repeating units contained in the polymer Q is total Preferably, the following formula is satisfied:

[0141] 80%≤(N qa +N qb +N qc +N qd ) / N total ≤100%.

[0142] (N qa +N qb +N qc +N qd ) / N total More preferably, it is 90 to 100%, and even more preferably, it is 95 to 100%. (N qa +N qb +N qc +N qd ) / N total =100%, that is, containing no structural units other than (Q-1a) to (Q-1d), which is also a preferred embodiment of the present invention.

[0143] The mass average molecular weight (hereinafter sometimes referred to as Mw) of the polymer Q is preferably 1,000 to 50,000, more preferably 2,000 to 30,000, and even more preferably 3,000 to 10,000.

[0144] The total mass M of the polymer P in the composition p and the total mass M of polymer Q q Preferably satisfying the formula: 0 <M p / (M p +M q )≤100%, more preferably 40≤M p / (M p +M q )≤90%.

[0145] In addition, it is preferable to satisfy 0≤Mq / (M p +M q )<70%, more preferably 10≤M q / (M p +M q )≤60%.

[0146] Polymer Q is a polymer having higher alkali solubility than polymer P. Polymer (A) may not contain polymer Q, but if it contains polymer Q, the resist pattern tends to have the following Figure 1 However, since polymer Q has high alkali solubility, when the content of polymer Q is 70% or more relative to the total mass of polymers P and Q, the cross-sectional shape of the resist pattern tends to be close to a cone, so care should be taken.

[0147] The polymer (A) may include polymers other than polymer P and polymer Q. The content of polymers other than polymers P and Q is preferably 60% or less, more preferably 30% or less, based on the total mass of the polymer (A). Polymers other than polymer P and polymer Q are not copolymerized with polymer P or polymer Q.

[0148] Polymers other than polymer P and polymer Q do not satisfy the requirements of a polymer containing a repeating unit selected from the above formulae (P-1) to (P-4), and further do not satisfy the requirements of a polymer containing a repeating unit represented by the above formula (Q-1).

[0149] The present invention also preferably includes no polymers other than the polymer P and the polymer Q.

[0150] The content of the polymer (A) is preferably 10 to 50% by mass, more preferably 30 to 40% by mass, based on the total mass of the composition.

[0151] (B) Acid generator having an imide group

[0152] The composition according to the present invention contains (B) an acid generator having an imide group (hereinafter sometimes referred to as the (B) acid generator). The (B) acid generator releases an acid upon irradiation with light, which acts on the polymer P to increase the solubility of the polymer in an alkaline aqueous solution. For example, if the polymer has an acid group protected by a protecting group, the protecting group is removed by the acid.

[0153] In the present invention, (B) the acid generator refers to the compound itself having the above-mentioned function. This compound can be dissolved or dispersed in a solvent and included in the composition, but such a solvent is preferably included in the composition as (D) the solvent or another component. The same applies to various additives that may be included in the composition.

[0154] The imide group in the present invention refers to a group having a -N< structure, but preferably has a structure -C(=O)-N(-Z)-C(=O)- (where Z is an organic group) in which a nitrogen atom exists between two carbonyl groups.

[0155] Preferably, the composition according to the present invention is substantially free of diazonaphthoquinone derivatives and quinonediazidesulfonate ester photosensitizers (hereinafter referred to as diazonaphthoquinone derivatives, etc.), which are commonly used as photosensitizers for phenolic resin polymers. In prior art techniques such as Patent Documents 1-3, diazonaphthoquinone derivatives, etc., are exposed to light to form carboxylic acids, which are used to increase the alkali solubility of the exposed portion. On the other hand, in the unexposed portion (the portion not exposed to light), the diazonaphthoquinone derivative is believed to increase the molecular weight of the phenolic resin polymer, thereby helping to suppress dissolution.

[0156] When the composition according to the present invention contains a diazonaphthoquinone derivative or the like, the cross-sectional shape of the resist pattern tends to be close to a cone. Therefore, the composition according to the present invention preferably does not contain a diazonaphthoquinone derivative or the like.

[0157] (B) The acid generator is preferably represented by formula (b).

[0158]

[0159] Where,

[0160] R b1 Each independently is C 3-10 Alkenyl or alkynyl (wherein CH3- in alkenyl and alkynyl may be substituted by phenyl, and -CH2- in alkenyl and alkynyl may be substituted by -C(=O)-, -O- or phenylene), C 2-10 Thioalkyl, C 5-10 Saturated heterocyclic ring.

[0161] nb is 0, 1, or 2, and

[0162] R b2 It is C 1-5 Here, in the fluorine substitution, at least one hydrogen atom may be replaced by fluorine, but preferably all hydrogen atoms are replaced by fluorine.

[0163] Here, in the present invention, an alkenyl group refers to a monovalent group having one or more double bonds (preferably one). Similarly, an alkynyl group refers to a monovalent group having one or more triple bonds (preferably one).

[0164] R b1 Preferably C 3-12 alkenyl or alkynyl (wherein CH3- in the alkenyl and alkynyl groups may be substituted by phenyl, and -CH2- in the alkenyl and alkynyl groups may be substituted by at least one of -C(=O)-, -O- or phenylene), C 3-5Thioalkyl, C 5-6 Saturated heterocyclic ring.

[0165] R b1 Specific examples include -C≡C-CH2-CH2-CH2-CH3, -CH=CH-C(=O)-O-tBu, -CH=CH-Ph, -S-CH(CH3)2, -CH=CH-Ph-O-CH(CH3)(CH2CH3) and piperidine. Here, tBu represents a tert-butyl group, and Ph represents a phenylene group or a phenyl group. Hereinafter, the same applies unless otherwise specified.

[0166] nb is preferably 0 or 1, more preferably nb = 0. nb = 1 is also a preferred form.

[0167] R b2 Preferably C 1-4 The alkyl group wherein all hydrogen atoms of C1 and C4 are replaced by fluorine atoms is more preferably an alkyl group wherein all hydrogen atoms of C1 and C4 are replaced by fluorine atoms. b2 The alkyl group is preferably straight-chain.

[0168] Specific examples of the (B) acid generator are as follows.

[0169]

[0170] For example, the following specific example can be represented by formula (b). b1 It is a C8 alkenyl group, which is -CH=CH-CH2-CH2-CH(CH3)(CH2CH3), wherein one -CH2- is replaced by a phenylene group, and one -CH2- is replaced by -O-. nb=1. R b2 Yes -CF3.

[0171]

[0172] The molecular weight of the acid generator (B) is preferably 400 to 1,500, more preferably 400 to 700.

[0173] The content of the acid generator (B) is 0.1 to 10.0% by mass, more preferably 0.5 to 1.0% by mass, based on the total mass of the polymer (A).

[0174] (C) Dissolution rate regulator

[0175] The composition according to the present invention comprises a dissolution rate regulator, which is a compound in which two or more phenol structures are linked via a hydrocarbon group, which is optionally substituted by an oxy group.

[0176] (C) dissolution rate regulator has the function of regulating the solubility of the polymer in the developer. Although not bound by theory, it is believed that due to the presence of (C) dissolution rate regulator, a preferred pattern shape is formed through the following mechanism. (C) dissolution rate regulator has a phenol structure and is highly soluble in alkaline developer. During the development process, the developer first contacts the upper part of the film. At this time, the (C) dissolution rate regulator present only near the surface of the film is dissolved in the developer. As a result, near the surface of the film in the unexposed part, the (C) dissolution rate regulator is lost, the polymer becomes high molecular weight, and the solubility in the alkaline developer is reduced. On the other hand, the side of the resist pattern formed is easily dissolved, and the cross-sectional shape of the resist pattern becomes an inverted cone shape. Through this mechanism, the dissolution rate regulator helps to form an inverted cone. As described above, the (C) dissolution rate regulator has the function of inhibiting or promoting dissolution and regulating the speed.

[0177] (C) The dissolution rate regulator is preferably a compound represented by formula (c).

[0178]

[0179] Where,

[0180] nc1 is each independently 1, 2 or 3.

[0181] nc2 is each independently 0, 1, 2 or 3.

[0182] R c1 Each independently is C 1-7 The alkyl group,

[0183] L c It is C 1-15 A divalent alkylene group (which may be substituted by an aryl group which may be substituted by a hydroxyl group, which may be substituted by L c (substituents other than the ) form a ring.

[0184] nc1 is preferably 1 or 2, more preferably 1, each independently.

[0185] nc2 is preferably independently 0, 2 or 3. In a preferred form, the two nc2 are the same. nc2 being 0 is also a preferred form.

[0186] R c1 Each independently preferably is a methyl group, an ethyl group or a cyclohexyl group, more preferably a methyl group or a cyclohexyl group.

[0187] L c Preferably C 2-12 A divalent alkylene group, more preferably C 2-7The aryl group that can replace the alkylene group can be a monovalent aryl group or a divalent arylene group. The aryl group is preferably a phenyl group or a phenylene group. The aryl group may be substituted with a hydroxyl group, but preferably one aryl group is substituted with one or two hydroxyl groups, more preferably one hydroxyl group. c The alkylene group may be linear, branched, or cyclic (preferably cyclohexylene) and may be any combination of these.

[0188] As L c As examples of substituents other than R forming a ring, for example, R c1 Or use OH and R c1 The following specific examples can be used as examples of the latter ring formation.

[0189]

[0190] L c Preferably -CR c2 R c3- (where R c2 is hydrogen or methyl and R c3 is an aryl group or an aryl-substituted alkyl group, wherein the aryl group may be substituted by a hydroxy group).

[0191] Specific examples of the dissolution rate regulator (C) are as follows.

[0192]

[0193] For example, the following specific example can be represented by formula (c): Both nc1 are 1, and both nc2 are 2. c1 All are methyl. c It is a C7 divalent alkylene group, but one -CH3 is replaced by a phenyl group, and the other tertiary carbon atom of the isopropyl group is replaced by a phenyl group substituted by a hydroxy group.

[0194]

[0195] The molecular weight of the dissolution rate regulator (C) is preferably 90 to 1,500, more preferably 200 to 900.

[0196] The content of the dissolution rate regulator (C) is preferably 0.1 to 20% by mass, more preferably 2 to 5% by mass, based on the total mass of the polymer (A).

[0197] (D) Solvent

[0198] The composition according to the present invention comprises (D) a solvent. The solvent is not particularly limited as long as it can dissolve the components to be mixed. The solvent (D) is preferably water, a hydrocarbon solvent, an ether solvent, an ester solvent, an alcohol solvent, a ketone solvent or a combination thereof.

[0199] Specific examples of the solvent include water, n-pentane, isopentane, n-hexane, isohexane, n-heptane, isoheptane, 2,2,4-trimethylpentane, n-octane, isooctane, cyclohexane, methylcyclohexane, benzene, toluene, xylene, ethylbenzene, trimethylbenzene, methylethylbenzene, n-propylbenzene, isopropylbenzene, diethylbenzene, isobutylbenzene, triethylbenzene, diisopropylbenzene, n-pentylnaphthalene, trimethylbenzene, methanol, ethanol, n-propanol, isobutylbenzene, Propanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-pentanol, isopentanol, 2-methylbutanol, sec-pentanol, tert-pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, sec-hexanol, 2-ethylbutanol, sec-heptanol, 3-heptanol, n-octanol, 2-ethylhexanol, sec-octanol, n-nonanol, 2,6-dimethylheptanol-4, n-decanol, sec-undecanol, trimethylnonanol, sec-tetradecanol, sec-heptadecanol , phenol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol, benzyl alcohol, diacetone alcohol, cresol, ethylene glycol, propylene glycol, 1,3-butanediol, pentanediol-2,4,2-methylpentanediol-2,4, hexanediol-2,5, heptanediol-2,4,2-ethylhexanediol-1,3, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, glycerol, acetone, methyl ethyl ketone, Methyl n-propyl ketone, methyl n-butyl ketone, diethyl ketone, methyl isobutyl ketone, methyl n-amyl ketone, ethyl n-butyl ketone, methyl n-hexyl ketone, diisobutyl ketone, trimethyl nonanone, cyclohexanone, cyclopentanone, methylcyclohexanone, 2,4-pentanedione, acetonyl acetone, diacetone alcohol, acetophenone, fenchone, ethyl ether, isopropyl ether, n-butyl ether (dibutyl 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-ethyl butyl 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, γ-butyrolactone, γ-valerolactone, n-propyl acetate, isopropyl acetate, n-butyl acetate (n-butyl acetate, nBA), isobutyl 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, methyl acetate Cyclohexyl acetate, n-nonyl acetate, methyl acetoacetate, ethyl acetoacetate, ethylene glycol acetate monomethyl ether, ethylene glycol acetate monoethyl ether, diethylene glycol acetate monomethyl ether, diethylene glycol acetate monoethyl ether, diethylene glycol acetate mono-n-butyl ether, propylene glycol acetate monomethyl ether, propylene glycol acetate monoethyl ether, propylene glycol acetate monopropyl ether, propylene glycol acetate monobutyl ether, dipropylene glycol acetate monomethyl ether, dipropylene glycol acetate monoethyl ether, ethylene glycol diacetate, methoxytriethylene glycol acetate, ethyl propionate, n-butyl propionate, isoamyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate (EL), γ -Butyrolactone, n-butyl lactate, n-pentyl lactate, 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.

[0200] The solvent (D) preferably contains a low-boiling-point solvent, and more preferably contains 60% or more of the low-boiling-point solvent based on the total mass of the solvent (D).

[0201] In the present invention, the low boiling point solvent refers to a solvent having a boiling point of 80 to 140° C., more preferably 110 to 130° C. The boiling point is measured at atmospheric pressure. Examples of the low boiling point solvent include PGME and nBA.

[0202] The (D) solvent is preferably PGME, EL, PGMEA, nBA, DBE, or any mixture thereof. When the two solvents 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). The (D) solvent is preferably a mixture of PGME and EL.

[0203] It is believed that since the (D) solvent contains at least one low-boiling-point solvent, the composition according to the present invention contributes to the formation of an inverted tapered shape. Without being bound by theory, it is believed to be the following mechanism. Since the (D) solvent contains a low-boiling-point solvent, when applied to a substrate and heated according to the present invention, the (D) solvent volatilizes more, and the content of the solvent is reduced in the formed film. In other words, it becomes a high-density film. Since the density of the film is high, the density of the acid generated from the (B) acid generator in the exposed part increases, and the frequency of acid diffusion increases. As mentioned above, due to having a higher molecular weight near the surface, the influence of the diffused acid is suppressed, but the side and bottom of the pattern are easily affected by the diffused acid. This contributes to the formation of an inverted tapered shape. In addition, when containing an alkaline compound (E), as described later, there is an effect of suppressing the diffusion of the acid in the upper part of the unexposed part, while the effect of suppressing the diffusion in the lower part is less, so it is further easy to form an inverted tapered shape.

[0204] Due to the relationship with other layers and the film, the solvent (D) may not contain water. For example, the amount of water in the solvent (D) as a whole 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.

[0205] The content of the solvent (D) is 40 to 90% by mass, more preferably 30 to 50% by mass, based on the total mass of the composition. The thickness of the film after formation can be controlled by increasing or decreasing the amount of the solvent in the entire composition.

[0206] (E) Basic compounds

[0207] The composition according to the present invention may further contain (E) a basic compound.

[0208] (E) alkaline compound has the effect of suppressing the diffusion of acid generated in the exposed part. Therefore, in the present invention, (E) alkaline compound is considered to play a role in helping to form an inverted cone shape. Although not bound by theory, it is believed that its mechanism is as follows. When the composition according to the present invention is applied to a substrate to form a film, (E) alkaline compound is uniformly present in the film. Afterwards, when heated, a portion of (E) alkaline compound present above the film evaporates in the atmosphere together with the solvent, and the non-volatile portion also moves upward. As a result, the distribution of (E) alkaline compound in the film is uneven, with more distribution in the upper part and less distribution in the lower part. Acid is released from the acid generator by exposure. When this acid diffuses to the unexposed part by heating after exposure, a neutralization reaction occurs with this (E) alkaline compound, thereby transferring the acid to the unexposed part. At this time, due to the uneven distribution of (E) alkaline compound in the film, the effect of suppressing the diffusion of acid above the film of the unexposed part is high, but the effect of suppressing the diffusion of acid below the film is low. That is, the acid distribution in the lower part is higher than that in the upper part. This helps to form an inverted cone when developing with an alkaline developer.

[0209] In addition to the above effects, the basic compound has a function of suppressing the deactivation of the acid on the resist film surface by amine components contained in the air.

[0210] (E) The basic compound is preferably selected from ammonia, C 1-16 Aliphatic primary amine, C 2-32 Aliphatic secondary amine, C 3-48 Aliphatic tertiary amine, C 6-30 Aromatic amines, and C 5-30 Heterocyclic amines and their derivatives.

[0211] Specific examples of the basic compound include ammonia, ethylamine, n-octylamine, ethylenediamine, triethylamine, triethanolamine, tripropylamine, tributylamine, triisopropanolamine, diethylamine, 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.

[0212] The molecular weight of the basic compound (E) is preferably 17 to 500, more preferably 100 to 350.

[0213] The content of the basic compound (E) is preferably 0 to 1.0% by mass, more preferably 0.05 to 0.3% by mass, based on the total mass of the polymer (A). In view of the storage stability of the composition, it is also preferred that the composition does not contain the basic compound (E).

[0214] (F) Plasticizer

[0215] The composition according to the present invention may further contain (F) a plasticizer. By adding a plasticizer, the generation of cracks in the resist pattern can be suppressed.

[0216] Examples of plasticizers include alkali-soluble vinyl polymers and vinyl polymers containing acid dissociation groups. More specifically, for example, polyvinyl chloride, polystyrene, polyhydroxystyrene, polyvinyl acetate, polyvinyl benzoate, polyvinyl ether, polyvinyl butyral, polyvinyl alcohol, polyether ester, polyvinyl pyrrolidone, polyacrylic acid, polymethacrylic acid, polyacrylate, polyimide maleate, polyacrylamide, polyacrylonitrile, polyvinyl phenol, phenolic resin and copolymers thereof, more preferably polyvinyl ether, polyvinyl butyral and polyether ester.

[0217] The (F) plasticizer preferably contains a structural unit represented by formula (f-1) and / or a structural unit represented by formula (f-2).

[0218] Formula (f-1) is expressed as follows.

[0219]

[0220] Where,

[0221] R f1 are each independently hydrogen or C 1-5 alkyl, and

[0222] R f2 are each independently hydrogen or C 1-5 of alkyl.

[0223] R f1 Preferably, each independently is hydrogen or methyl.

[0224] R f2 Preferably, each independently is hydrogen or methyl.

[0225] More preferably, both R f1 and two R f2 One of the three is a methyl group and the remaining three are hydrogen atoms.

[0226] Formula (f-2) is expressed as follows.

[0227]

[0228] Where,

[0229] R f3 are each independently hydrogen or C 1-5 The alkyl group, R f4 is hydrogen or C 1-5 alkyl, and

[0230] R f5 It is C1-5 of alkyl.

[0231] R f3 Preferably, each independently is hydrogen or methyl, more preferably both are hydrogen.

[0232] R f4 It is preferably hydrogen or methyl, more preferably hydrogen.

[0233] R f5 It is preferably a methyl group or an ethyl group, and more preferably a methyl group.

[0234] Specific examples of the (F) plasticizer are as follows.

[0235]

[0236] PO: Propylene oxide

[0237]

[0238] The mass average molecular weight of the (F) plasticizer is preferably 1,000 to 50,000, more preferably 1,500 to 30,000, further preferably 2,000 to 21,000, and even more preferably 3,000 to 21,000.

[0239] The content of the plasticizer (F) is preferably 0 to 30% by mass, more preferably 1 to 10% by mass, based on the total mass of the polymer (A). Containing no plasticizer is also a preferred embodiment of the present invention.

[0240] (G) Additives

[0241] The composition according to the present invention may contain (G) additives in addition to (A) to (F).

[0242] (G) The additive is not particularly limited, but is preferably at least one selected from a surfactant, an acid, and a substrate adhesion enhancer.

[0243] The content of the additive (G) is 0 to 20% by mass, more preferably 0 to 11% by mass, based on the total mass of the polymer (A). A composition according to the present invention in which (G) contains no additive (0% by mass) is also a preferred example.

[0244] By including a surfactant, coating properties 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. Specifically, preferred are (I) alkylsulfonates, alkylbenzenesulfonic acids, and alkylbenzenesulfonates; (II) octylpyridinium chloride and octylmethylchloride; and (III) polyoxyethylene octyl ether, polyoxyethylene octyl ether, and polyoxyethylene acetylene glycol ether.

[0245] These surfactants may be used alone or in combination of two or more. The content thereof is preferably 2% by mass or less, more preferably 1% by mass or less, based on the total mass of the polymer (A).

[0246] Acids can be used to adjust the pH of the composition and increase the solubility of additive components. The acid used is not particularly limited, and examples 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, propylene tricarboxylic acid, adipic acid, and combinations thereof. The acid content is preferably 0.005 to 0.1% by mass (50 to 1,000 ppm) based on the total mass of the composition.

[0247] By using a substrate adhesion enhancer, pattern peeling due to stress applied during film formation can be prevented. As substrate adhesion enhancers, imidazoles and silane coupling agents are preferred. Among imidazoles, 2-hydroxybenzimidazole, 2-hydroxyethylbenzimidazole, benzimidazole, 2-hydroxyimidazole, imidazole, 2-mercaptoimidazole, and 2-aminoimidazole are preferred. 2-hydroxybenzimidazole, benzimidazole, 2-hydroxyimidazole, and imidazole are more preferred. Based on the total mass of the (A) polymer, the content of the substrate adhesion enhancer is preferably 0 to 10% by mass, more preferably 0 to 5% by mass, further preferably 0.01 to 5% by mass, and further preferably 0.1 to 3% by mass.

[0248] <Method for Manufacturing Resist Pattern>

[0249] The method for manufacturing a resist pattern according to the present invention comprises:

[0250] (1) applying the composition according to the present invention onto a substrate;

[0251] (2) heating the composition to form a resist layer;

[0252] (3) exposing the resist layer;

[0253] (4) heating the resist layer after exposure; and

[0254] (5) The resist layer is developed.

[0255] For clarity, numbers in brackets indicate the order. For example, step (1) is performed before step (2).

[0256] Hereinafter, one embodiment of the production method of the present invention will be described.

[0257] The composition according to the present invention is applied to 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 an appropriate method. Here, in the present invention, "above" includes the case where it is directly formed on the top and the case where it is formed through another layer. For example, a planarization film or a resist underlayer film can be formed directly above the substrate, and the composition according to the present invention is applied directly above the planarization film or the resist underlayer film. There is no particular limitation on the coating method, such as a coating method by a spinner and a coater. After coating, the resist layer is formed by heating. The heating of (2) is performed, for example, by a hot plate. The heating temperature is preferably 60 to 140°C, more preferably 90 to 110°C. The temperature here is a heating atmosphere, such as the heating surface temperature of a heating plate. The heating time is preferably 30 to 900 seconds, more preferably 60 to 300 seconds. The heating is preferably performed in air or a nitrogen atmosphere.

[0258] The thickness of the resist layer is selected according to the intended purpose. However, when the composition according to the present invention is used, a thicker coating film can be formed, thereby enabling formation of a pattern with a better shape. Therefore, the thickness of the resist film is preferably thicker, for example, preferably 1 μm or more, more preferably 5 μm or more.

[0259] The resist layer is exposed through a predetermined mask. The wavelength of the light used for exposure is not particularly limited, but preferably light with a wavelength of 190 to 440 nm is used for exposure. Specifically, KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), i-line (wavelength 365 nm), h-line (wavelength 405 nm), g-line (wavelength 436 nm), etc. can be used. The wavelength is more preferably 240 to 440 nm, further preferably 360 to 440 nm, and even more preferably 365 nm. These wavelengths are allowed within a range of ±1%.

[0260] After exposure, post-exposure heating (hereinafter sometimes referred to as PEB) is performed. The heating in (4) is performed, for example, on a hot plate. The temperature of the post-exposure heating is preferably 80 to 160°C, more preferably 105 to 115°C, and the heating time is 30 to 600 seconds, preferably 60 to 200 seconds. Heating is preferably performed in air or a nitrogen atmosphere.

[0261] After PEB, development is performed using a developer. As a development method, methods conventionally used to develop photoresists, such as paddle development, immersion development, and shaking immersion development, can be used. The developer can use an aqueous solution containing inorganic bases such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, organic amines such as ammonia, ethylamine, propylamine, diethylamine, diethylaminoethanol, triethylamine, tetramethylolamine (TMAH), etc., preferably a 2.38% by 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 30 to 60 seconds. After development, if necessary, water washing or rinsing can be used. Since a positive resist composition is used, the exposed portion is removed by development to form a resist pattern. The resist pattern can also be further refined by using, for example, a shrinking material.

[0262] Since the unexposed portion is hardly dissolved in the developer by development, the thickness of the formed resist pattern and the resist layer can be considered to be the same.

[0263] By using the composition of the present invention, a resist pattern having an inverted tapered shape can be formed. Here, in the present invention, the inverted tapered shape refers to a resist pattern having an inverted tapered shape. Figure 1 As shown in the cross-sectional view of (A), when a resist pattern 12 is formed on a substrate 11, the angle formed by the straight line (taper line) connecting the opening point (the boundary between the resist surface and the side of the resist pattern) 13 and the bottom point (the boundary between the substrate surface and the side of the resist pattern) 14 with the substrate surface is greater than 90 degrees, and the resist pattern does not substantially protrude outward compared to the tapered line, that is, the resist pattern does not substantially swell. Here, this angle is called a taper angle 15. Such a resist pattern is called a resist pattern 12 with an inverted cone shape. In the present invention, the inverted cone not only refers to an inverted truncated cone shape, but also includes a case where the line width of the surface portion is wider than the line width near the substrate in a linear pattern.

[0264] In the resist pattern of the inverse tapered shape according to the present invention, as Figure 1As shown in the cross-sectional view of (B), the resist pattern is also recessed inward from the straight line (taper line 24) connecting the opening point 2 and the bottom point 23, that is, the case where the resist pattern is thin. The taper angle here is the taper angle 25. This resist pattern is called an overhang-shaped resist pattern 21. Draw a straight line parallel to the substrate surface at a height 27 of half the length 26 of the film thickness 26 of the resist pattern from the substrate. On this straight line, the distance between the intersection with the resist pattern and the intersection with the tapered line is the bite width 28. Similarly, on this straight line, the distance between the intersection with the resist pattern and the intersection with the straight line drawn perpendicular to the substrate from the opening point is called the taper width 29. When the bite width / taper width is greater than 0, it is Figure 1 (B) is 0. Figure 1 (A).

[0265] The overhang shape is preferable because a release liquid can easily enter when the resist is peeled off after metal deposition.

[0266] As a variation of the overhang shape, Figure 1 As shown in (C), the case where the end of the resist pattern 31 is rounded can be considered. In this case, the opening point 32 is the point where the resist pattern separates from the plane of the resist surface parallel to the bottom surface, assuming that the boundary between the resist surface and the side of the resist pattern is the plane of the resist surface. 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 the taper angle 35.

[0267] The area of ​​the non-resist pattern portion inside the tapered line is S in 36, the area of ​​the non-resist pattern portion outside the tapered line is S out 37. In multiple cases, the sum of the areas used.

[0268] S out / (S in +S out ) is preferably 0 to 0.45, more preferably 0 to 0.1, further preferably 0 to 0.05, and even more preferably 0 to 0.01. out / (S in +S out ) is advantageous because even if the metal is thickly deposited on the resist pattern, the stripping liquid easily penetrates the resist sidewall. The T-shaped resist pattern described in Patent Document 3 has an S of about 0.5. out / (S in +S out ).

[0269] (S in -S out ) / (S in +Sout ) is preferably 0 to 1, more preferably 0.55 to 1, further preferably 0.9 to 1, and further preferably 0.99 to 1. 0<(S in -S out ) / (S in +S out ) is also a preferred form of the present invention. When (S in -S out ) / (S in +S out ) is large, the overall resist pattern is a shape that is concave inward from the tapered line. Even if a thicker metal is evaporated on the resist pattern, the stripping liquid can easily penetrate into the resist side wall, which is advantageous.

[0270] Corresponding to Figure 1 In the case of shapes (A) and (B), both are S out / (S in +S out )=0, and both are (S in -S out ) / (S in +S out )=1.

[0271] When forming a resist pattern using a chemically amplified resist, it is known that the resist pattern shape changes as the post-exposure delay (PED) (post-exposure delay) from exposure to PEB (post-exposure delay) increases. This phenomenon is believed to occur when the acid generated in the exposed portion of the resist is neutralized by alkaline compounds (such as amines) in the air, reducing the solubility of the resist film surface in the exposed portion. The top portion of the resist film is particularly susceptible to this effect, and the exposed portion may remain partially undeveloped.

[0272] The composition according to the present invention is less susceptible to the above-mentioned shape changes than conventionally known compositions. In other words, it has the property of being resistant to environmental influences.

[0273] In addition, the metal pattern can be manufactured by a method including the following steps.

[0274] (6) using the resist pattern as a mask, evaporating metal on the substrate;

[0275] (7) The resist pattern is removed using a stripping solution.

[0276] Using the resist pattern as a mask, a metal such as gold or copper (which may be a metal oxide, etc.) is vapor-deposited on the substrate. In addition to vapor deposition, sputtering can also be used.

[0277] Afterwards, the resist pattern can be formed by removing the metal formed thereon together with the resist pattern using a stripping solution. The stripping solution is not particularly limited as long as it is used as a stripping solution for the resist, and for example, N-methylpyrrolidone (NMP), acetone, an alkaline solution, etc. can be used. Since the resist pattern of the present invention has an inverted tapered shape, the metal on the resist pattern and the metal formed in the portion where the resist pattern is not formed are separated from each other, thereby making it easy to strip. In addition, the film thickness of the formed metal pattern can be increased to form a metal pattern with a film thickness of preferably 0.01 to 40 μm, more preferably 1 to 5 μm.

[0278] As another embodiment of the present invention, the resist pattern formed until step (5) can be used as a mask to pattern various substrates as a 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 lower layer film can be patterned using the resist pattern as a mask, and the substrate can be patterned using the resist lower layer film pattern as a mask. Processing can be performed using a known method, but dry etching, wet etching, ion implantation, metal plating, etc. can be used. Electrodes, etc. can also be arranged on the patterned substrate.

[0279] Then, as needed, the substrate is further processed to form a device. Known methods can be applied to these further processes. After forming the device, if necessary, the substrate is cut into chips, connected to a lead frame, and encapsulated with a resin. In the present invention, the product after this encapsulation is referred to as a device. Examples of devices include semiconductor devices, liquid crystal display elements, organic EL display elements, plasma display elements, and solar cell elements. The device is preferably a semiconductor.

[0280] [Example]

[0281] The present invention will be described below with reference to various embodiments, but aspects of the present invention are not limited to these examples.

[0282] Example 1: Preparation of Composition 1

[0283] To 170 parts by mass of a mixed solvent of PGME:EL=85:15 (mass ratio), 50 parts by mass of the following P1 as polymer P and 150 parts by mass of the following Q as polymer Q were added. 1.6% by mass of the following B1 as an acid generator, 2.5% by mass of the following C1 as a dissolution rate regulator, 0.1% by mass of tris[2-(2-methoxyethoxy)ethyl]amine as a basic compound, 5.0% by mass of the following F1 as a plasticizer, and 0.1% by mass of KF-53 (Shin-Etsu Chemical Co., Ltd.) as a surfactant were added thereto, based on the total mass of the entire composition. Stirring was carried out at room temperature for 5 hours. Visual confirmation was made that the additives had dissolved. The mixed solution was filtered through a 1.0 μm filter. Composition 1 was thus obtained. The viscosity of Composition 1 measured at 25°C by the Canon Fenske method was 600 cP.

[0284]

[0285] (P1) Hydroxystyrene-styrene-tert-butyl acrylate copolymer, Toho Chemical Co., Ltd., molar ratio 60:20:20, Mw approximately 12,000

[0286]

[0287] (Q1)(Q-1a):(Q-1b):(Q-1c):(Q-1d)=60:40:0:0, Sumitomo Bakelite Co., Ltd., Mw is about 5,000

[0288]

[0289] (B1) NIT, Heraeus

[0290]

[0291] (C1) TPPA-MF, Honshu Chemical Industry Co., Ltd.

[0292]

[0293] (F1) Lutonal, BASF

[0294] Examples 2 to 10 and Comparative Examples 1 to 3: Preparation of Compositions 2 to 10 and Comparative Compositions 1 to 2

[0295] Compositions 2 to 10, and comparative compositions 1 to 3 were prepared similarly to composition 1, except that the polymer and dissolution rate modifier were changed as described in Table 1.

[0296] Table 1

[0297]

[0298] Resist pattern formation

[0299] The composition obtained above was used to perform the following operations to obtain a resist pattern.

[0300] Each composition was dropped onto a 6-inch silicon wafer using a LITHOTRAC (Litho Tech Japan) and spin-coated to form a resist layer. The wafer with the resist layer formed on it was baked at 100°C for 180 seconds using a hot plate. After baking, the thickness of the resist layer was measured using a Lambda Ace VM-12010 (SCREEN) optical interference film thickness measurement device. The film thickness was measured at 8 points outside the center of the wafer, and the average value was used. The resulting film thickness is shown in Table 1.

[0301] The wafer was then exposed to i-line (365 nm) using a Suss Aligner (Suss MicroTech). After exposure, the wafer was exposed on a 120°C hot plate for 120 seconds and then heated. It was then spin-immersion developed with a 2.38% TMAH aqueous solution for 60 seconds. This yielded a resist pattern with 10 μm lines and 10 μm spaces (grooves) (line:space = 1:1).

[0302] In the case of Example 1, the exposure energy (mJ / cm2) when the mask size and pattern size are 1:1 is 2 ) is 120mJ / cm 2 .

[0303] Evaluation of cone angle

[0304] The cross-sectional shape of the obtained resist pattern was observed using a scanning electron microscope SU8230 (Hitachi Technologies, Ltd.), and the taper angle defined above was measured. The cross-sectional shape of the resist pattern formed in Example Composition 5 is shown in FIG. Figure 2 (A) in. Figure 2 The results are shown in Table 1.

[0305] In the cross-sectional shape of the resist pattern formed in Example Composition 5, S as defined above out / (S in +S out )=0,(S in -S out ) / (S in +S out )=1.

[0306] Crack resistance evaluation

[0307] Compositions containing no plasticizer, 2.5% plasticizer, 7.5% plasticizer, and 10.0% plasticizer were prepared from the composition of Example Composition 1 (which contained 5% plasticizer by mass). Resist patterns were formed in the same manner as above, and gold was vapor-deposited using a sputtering device. Afterwards, the presence or absence of cracks was visually confirmed using an optical microscope. While a small amount of cracks was confirmed in the absence of plasticizer, the cracks were reduced in the presence of 2.5% plasticizer compared to the absence of plasticizer. No cracks were confirmed in the compositions containing 5%, 7.5%, and 10.0% plasticizer by mass.

[0308] Description of Reference Numerals

[0309] 11.Substrate

[0310] 12. Inverted tapered resist pattern

[0311] 13. Opening point

[0312] 14. Bottom

[0313] 15. Cone Angle

[0314] 21. Overhanging shape resist pattern

[0315] 22. Opening point

[0316] 23. Bottom

[0317] 24. Tapered Line

[0318] 25. Cone Angle

[0319] 26. Film thickness of resist pattern

[0320] 27. Half the length of the resist pattern thickness

[0321] 28. Bite width

[0322] 29. Cone Width

[0323] 31.Resist pattern

[0324] 32. Opening point

[0325] 33. Bottom point

[0326] 34. Tapered Line

[0327] 35. Cone Angle

[0328] 36.S in

[0329] 37.S out

[0330] 51.Substrate

[0331] 52. Resist pattern.

Claims

1. A positive resist composition comprising: (A) at least one polymer selected from polymer P and polymer Q, The polymer P contains repeating units selected from the group consisting of formulae (P-1) to (P-4): Where, R p1 、R p3 、R p5 and R p8 Each independently is C 1-5 Alkyl, C 1-5 Alkoxy or -COOH, R p2 、R p4 and R p7 Each independently is C 1-5 Alkyl, where -CH2- in the alkyl group is unsubstituted or substituted by -O-, R p6 and R p9 Each independently is C 1-5 Alkyl, where -CH2- in the alkyl group is unsubstituted or substituted by -O-, x1 is 0 to 4, x2 is 1 to 2, where x1+x2≤5, x3 is 0 to 5, x4 is 1 to 2, x5 is 0 to 4, where x4+x5≤5, In polymer (A), the number of repeating units of formula (P-1), (P-2), (P-3) and (P-4) is n p1 、n p2 、n p3 and n p4 , they satisfy the following formula: 30%≤n p1 / (n p1 +n p2 +n p3 +n p4 )≤90%, 0%≤n p2 / (n p1 +n p2 +n p3 +n p4 )≤40%, 0%≤n p3 / (n p1 +n p2 +n p3 +n p4 )≤40%, and 0% ≤ n p4 / (n p1 +n p2 +n p3 +n p4 )≤40%, Polymer Q comprises a repeating unit represented by formula (Q-1): Where, R q1 Each independently is C 1-5 alkyl, y1 is 1 to 2, y2 is 0 to 3, where y1+y2≤4 in, The total mass M of the polymer P in the composition p and the total mass M of polymer Q q Satisfied: 0 <M p / (M p +M q )≤90%, and 10%≤M q / (M p +M q )<70%; (B) an acid generator having an imide group; (C) a dissolution rate regulator, which is a compound having two or more phenol structures linked by a hydrocarbon group, wherein the hydrocarbon group is unsubstituted or substituted by an oxy group; and (D) Solvent.

2. The composition according to claim 1, wherein 40%≤M p / (M p +M q )≤90%, and 10%≤M q / (M p +M q )≤60%.

3. The composition according to claim 1 or 2, wherein Polymer Q comprises repeating units selected from formulae (Q-1a) to (Q-1d): Number of repeating units N of (Q-1a) qa 、N number of repeating units of (Q-1b) qb 、N number of repeating units of (Q-1c) qc and the number of repeating units N of (Q-1d) qd Satisfy the following formula: 30%≤N qa / (N qa +N qb +N qc +N qd )≤100%; 0%≤N qb / (N qa +N qb +N qc +N qd )≤70%; 0%≤N qc / (N qa +N qb +N qc +N qd )≤50%; and 0%≤N qd / (N qa +N qb +N qc +N qd )≤70%。 4. The composition according to claim 1 or 2, wherein The composition further comprises (E) a basic compound.

5. The composition according to claim 1 or 2, wherein The composition further comprises (F) a plasticizer.

6. The composition according to claim 1 or 2, wherein The content of the acid generator (B) is 0.1 to 10.0% by mass based on the total mass of the polymer (A).

7. The composition according to claim 1 or 2, wherein The content of the (A) polymer is 10 to 50% by mass based on the total mass of the composition.

8. The composition according to claim 1 or 2, wherein The content of the dissolution rate regulator (C) is 0.1 to 20% by mass based on the total mass of the polymer (A).

9. The composition according to claim 1 or 2, wherein The content of the (D) solvent is 40 to 90% by mass based on the total mass of the composition.

10. The composition according to claim 1 or 2, wherein The content of the basic compound (E) is 0 to 1.0% by mass based on the total mass of the polymer (A).

11. The composition according to claim 1 or 2, wherein The content of the plasticizer (F) is 0 to 30% by mass based on the total mass of the polymer (A).

12. The composition according to claim 1 or 2, wherein (B) The acid generator is represented by formula (b): Where, R b1 Each independently is C 3-10 Alkenyl or alkynyl, C 2-10 Thioalkyl, C 5-10 a saturated heterocycle in which the CH3- in the alkenyl and alkynyl groups is unsubstituted or substituted by phenyl, and the -CH2- in the alkenyl and alkynyl groups is unsubstituted or substituted by -C(=O)-, -O- or phenylene, nb is 0, 1, or 2, and R b2 It is C 1-5 fluorine-substituted alkyl; (C) The dissolution rate regulator is represented by formula (c): Where, nc1 are each independently 1, 2 or 3, nc2 are each independently 0, 1, 2 or 3, R c1 Each independently is C 1-7 The alkyl group, L c It is C 1-15 A divalent alkylene group, which is unsubstituted or substituted by an aryl group, which is unsubstituted or substituted by a hydroxyl group, and L c Substituents other than the α-amino group may form a ring or not; (E) the basic compound is selected from ammonia, C 1-16 Aliphatic primary amine, C 2-32 Aliphatic secondary amine, C 3-48 Aliphatic tertiary amine, C 6-30 Aromatic amines, and C 5-30 Heterocyclic amines and their derivatives; (F) The plasticizer is a compound containing a structural unit represented by formula (f-1) and / or a structural unit represented by formula (f-2): Where, R f1 are each independently hydrogen or C 1-5 alkyl, and R f2 are each independently hydrogen or C 1-5 The alkyl group, Where, R f3 are each independently hydrogen or C 1-5 The alkyl group, R f4 is hydrogen or C 1-5 alkyl, and R f5 It is C 1-5 of alkyl.

13. The composition according to claim 1 or 2, wherein The viscosity of the composition is 50 to 2,000 cP at 25°C. 14 . The composition according to claim 1 , which is a positive resist composition that forms an inverse tapered shape.

15. The composition according to claim 1 or 2, which is a positive resist stripping composition.

16. A method for manufacturing a resist pattern, comprising the following steps: (1) applying the composition according to any one of claims 1 to 13 onto a substrate; (2) heating the composition to form a resist layer; (3) exposing the resist layer; (4) heating the resist layer after exposure; and (5) The resist layer is developed.

17. The method according to claim 16, wherein The resist pattern has a film thickness of 1 to 50 μm.

18. The method according to claim 16 or 17, wherein The resist pattern has an inverted tapered shape.

19. A method for manufacturing a metal pattern, comprising: Manufacturing a resist pattern according to the method of claim 16; (6) Using the resist pattern as a mask, evaporating metal on the substrate; and (7) The resist pattern is removed using a stripping solution.

20. The method according to claim 19, wherein The metal pattern has a thickness of 0.01 to 40 μm.

21. A method for manufacturing a device, comprising the method according to any one of claims 16 to 20.

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