JP6361361B2 - Positive lift-off resist composition and pattern forming method - Google Patents

Description

  The present invention relates to a positive lift-off resist composition and a lift-off resist pattern forming method.

A lift-off method is known as means for forming various metal wiring patterns such as aluminum, copper, and tantalum on a semiconductor substrate. In the lift-off method, for example, a resist composition is applied onto a substrate, exposed through a mask, developed to form a resist pattern on the substrate, and then a metal film is sputtered onto the resist pattern and the metal substrate. The resist pattern and the metal film on the pattern are peeled together to form a metal wiring on the substrate. A desirable resist pattern shape used in this lift-off method is a shape having an undercut called a microgroove below the resist pattern (substrate grounding portion).
Reports on conventional positive lift-off resist compositions having such a shape have been made in JP-A-8-69111 (Patent Document 1) and JP-A-10-97066 (Patent Document 2). Both reports have commonality in that undercuts are generated by aromatic hydroxy compounds, although the constituents are different. This is because the aromatic hydroxy compound has an appropriate alkali dissolution rate in generating undercut near the substrate and controlling its size. In addition, in Japanese Unexamined Patent Publication No. 2012-108415 (Patent Document 3), by adding an alkali-soluble cellulose resin, it is possible to further increase the undercut and form a thick metal film.
However, the conventional technique has a problem that when the temperature becomes high during film formation, the pattern is deformed by the influence of heat and the desired film formation cannot be performed.

JP-A-8-69111 Japanese Patent Laid-Open No. 10-97066 JP 2012-108415 A

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a positive lift-off resist composition and a pattern forming method capable of forming a pattern without deformation even at a high temperature of 120 ° C. or higher.

〔５〕
更に、（Ｄ）光酸発生剤を含有することを特徴とする〔１〕〜〔４〕のいずれかに記載のポジ型リフトオフレジスト組成物。
〔６〕
（Ｅ）成分の芳香族ヒドロキシ化合物が、下記式（１），（２）又は（５）

（式中、ｊは１又は２、ｋ、ｍ、ｐはそれぞれ０〜３、ｎは１〜４、ｑは１〜３、ｒは２又は３の整数で、ｍ＋ｐ＋ｎ≦６、ｋ＋ｑ≦５、ｍ＋ｑ≦５である。）

［（式中、Ｒａ、Ｒｂ、Ｒｃ、Ｒｄ、Ｒｅ、Ｒｆはそれぞれ独立して水素原子、メチル基、又は下記式（６）で示される基であって、Ｒａ、Ｒｂ、Ｒｃの少なくとも一つ及びＲｄ、Ｒｅ、Ｒｆの少なくとも一つはベンゼン環にヒドロキシ基が付加した構造を有する。ｘ、ｙはそれぞれ０〜３の整数である。）

（式中、ｖ、ｗはそれぞれ０〜３の整数である。）］
で示される化合物から選ばれるものであり、アルカリ可溶性ノボラック樹脂（Ａ）１００質量部に対し２〜７０質量部を配合した〔１〕〜〔５〕のいずれかに記載のポジ型リフトオフレジスト組成物。
〔７〕
更に、（Ｆ）アルカリ可溶性セルロースを含有することを特徴とする〔１〕〜〔６〕のいずれかに記載のポジ型リフトオフレジスト組成物。
〔８〕
（Ｆ）成分のアルカリ可溶性セルロースが、下記構造式（３）

［式中、Ｒ¹は独立に、酸価３０〜１５０ｍｇＫＯＨ／ｇを示す範囲において、水素原子、炭素数１〜４のアルキル基、炭素数１〜４のヒドロキシアルキル基、炭素数１〜８のアシル基又は下記構造式（４）

（式中、Ｒ’は炭素数１〜６のアルキレン基、フェニレン基又はシクロヘキシレン基である。）
で表される有機基であり、かつＲ¹中の上記式（４）で表される有機基の割合が単位グルコース環あたり平均２〜３０モル％であり、ｓは２〜１０，０００の整数である。］
で表されるものである〔７〕記載のポジ型リフトオフレジスト組成物。
〔９〕
〔１〕〜〔８〕のいずれかに記載のレジスト組成物を基板に塗布する工程（ａ）と、次いで加熱処理後、フォトマスクを介して放射線もしくは電子線で露光する工程（ｂ）と、必要に応じて加熱処理した後、現像液を用いて現像する工程（ｃ）と、その後、得られたレジストパターンに対し第二の放射線で照射する工程（ｄ）及び／又は１２０〜２２０℃で熱処理を行う工程（ｅ）とを有することを特徴とするパターン形成方法。
〔１０〕
上記工程（ｄ）及び／又は（ｅ）の後、基板上に形成したレジストパターン全面にメタル層を形成し、次いでレジストパターンと該パターン上に形成されたメタル層とを剥離することにより基板上にメタルパターンを形成することを特徴とする〔９〕記載のパターン形成方法。
As a result of intensive studies to achieve the above object, the present inventors have found that (A) an alkali-soluble novolak resin, (B) an aromatic hydroxy compound containing a methoxymethyl group or a hydroxymethyl group, (C) a quinonediazide sulfone. It has been found that a composition containing an acid ester photosensitizer has a large undercut and forms a pattern having high heat resistance, and has led to the present invention.
Accordingly, the present invention provides the following high heat resistant positive lift-off resist composition and resist pattern forming method.
[1]
(A) an alkali-soluble novolak resin,
(B) an aromatic hydroxy compound containing a methoxymethyl group or a hydroxymethyl group,
(C) a quinonediazide sulfonic acid ester photosensitizer , and
(E) A positive lift-off resist composition comprising an aromatic hydroxy compound not containing an alkoxyalkyl group and a hydroxyalkyl group having a weight average molecular weight of 180 to 800 .
[2]
The positive lift-off resist composition according to [1], wherein the aromatic hydroxy compound containing a methoxymethyl group or a hydroxymethyl group as the component (B) has a weight average molecular weight of 300 to 10,000.
[3]
The aromatic hydroxy compound containing a methoxymethyl group or a hydroxymethyl group as the component (B) contains 3 to 50 parts by mass with respect to 100 parts by mass of the (A) alkali-soluble novolak resin [1] or [1] 2] The positive lift-off resist composition described in [2].
[4]
(B) The positive lift-off resist according to any one of [1] to [3], wherein the aromatic hydroxy compound containing a methoxymethyl group or a hydroxymethyl group is at least one selected from the following formulas Composition.

[5]
The positive lift-off resist composition according to any one of [1] to [4], further comprising (D) a photoacid generator.
[ 6 ]
The aromatic hydroxy compound of component (E) is represented by the following formula (1), (2) or (5)

(Wherein j is 1 or 2, k, m and p are 0 to 3, n is 1 to 4, q is 1 to 3, r is an integer of 2 or 3, and m + p + n ≦ 6, k + q ≦ 5, m + q ≦ 5.)

[In the formula, Ra, Rb, Rc, Rd, Re, and Rf are each independently a hydrogen atom, a methyl group, or a group represented by the following formula (6), and at least one of Ra, Rb, and Rc. And at least one of Rd, Re, and Rf has a structure in which a hydroxy group is added to a benzene ring, and x and y are each an integer of 0 to 3.)

(Wherein v and w are each an integer of 0 to 3)]
The positive lift-off resist composition according to any one of [ 1 ] to [5], wherein the composition is selected from the compounds represented by the formula ( 1 ) to (5) in which 2 to 70 parts by mass are blended with 100 parts by mass of the alkali-soluble novolak resin (A). .
[ 7 ]
The positive lift-off resist composition according to any one of [1] to [ 6 ], further comprising (F) alkali-soluble cellulose.
[ 8 ]
The alkali-soluble cellulose as component (F) has the following structural formula (3)

[In the formula, R ¹ is independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms, or an alkyl group having 1 to 8 carbon atoms in a range showing an acid value of 30 to 150 mgKOH / g. Acyl group or the following structural formula (4)

(In the formula, R ′ represents an alkylene group having 1 to 6 carbon atoms, a phenylene group, or a cyclohexylene group.)
The ratio of the organic group represented by the above formula (4) in R ¹ is an average of 2 to 30 mol% per unit glucose ring, and s is an integer of 2 to 10,000 It is. ]
[ 7 ] The positive lift-off resist composition according to [ 7 ].
[ 9 ]
A step (a) of applying the resist composition according to any one of [1] to [ 8 ] to a substrate, a step (b) of exposing to radiation or an electron beam through a photomask after a heat treatment, and After the heat treatment as necessary, a step (c) of developing using a developer, and then a step (d) of irradiating the obtained resist pattern with a second radiation and / or at 120 to 220 ° C. And (e) performing a heat treatment.
[1 0 ]
After the step (d) and / or (e), a metal layer is formed on the entire resist pattern formed on the substrate, and then the resist pattern and the metal layer formed on the pattern are peeled off to form the substrate. A metal pattern is formed on the pattern forming method according to [ 9 ].

  The high heat-resistant positive lift-off resist composition of the present invention can be suitably used for obtaining a pattern having an undercut shape that requires high heat resistance.

It is sectional drawing of the resist pattern formed with a positive type lift-off resist composition.

Hereinafter, the present invention will be described in more detail.
The high heat-resistant positive lift-off resist composition according to the present invention comprises (A) an alkali-soluble novolak resin, (B) an aromatic hydroxy compound containing an alkoxyalkyl group or a hydroxyalkyl group, and (C) a quinonediazide sulfonate ester photosensitizer. An agent is an essential component.
(A) The alkali-soluble novolak resin can be synthesized as a condensation reaction product of phenols and aldehydes. Examples of the phenols include xylenols such as phenol, m-cresol, p-cresol, o-cresol, 2,3-xylenol, 2,5-xylenol, 3,5-xylenol, 3,4-xylenol, m- Alkylphenols such as ethylphenol, p-ethylphenol and o-ethylphenol; alkoxyphenols such as p-methoxyphenol and m-methoxyphenol; isopropenylphenols such as p-isopropenylphenol and o-isopropenylphenol; Examples thereof include polyhydroxyphenols such as bisphenol A. These may be used alone or in combination of two or more. Among these phenols, m-cresol, p-cresol, o-cresol, 2,5-xylenol, and 3,5-xylenol are particularly preferably used.

  Examples of the aldehydes include formaldehyde, paraformaldehyde, trioxane, acetaldehyde, propionaldehyde, butyraldehyde, trimethylacetaldehyde, acrolein, crotonaldehyde, cyclohexanealdehyde, furfural, furylacrolein, benzaldehyde, terephthalaldehyde, phenylacetaldehyde, α-phenylpropyl. Aldehyde, β-phenylpropylaldehyde, o-hydroxybenzaldehyde, m-hydroxybenzaldehyde, p-hydroxybenzaldehyde, o-methylbenzaldehyde, m-methylbenzaldehyde, p-methylbenzaldehyde, o-chlorobenzaldehyde, m-chlorobenzaldehyde, p- Such as chlorobenzaldehyde It is. These may be used alone or in combination of two or more. Among these aldehydes, formaldehyde is preferable because of its availability.

The condensation reaction product of phenols and aldehydes can be produced by a known method in the presence of an acidic catalyst. As an acidic catalyst in that case, hydrochloric acid, sulfuric acid, formic acid, oxalic acid, p-toluenesulfonic acid and the like can be used. As the condensation reaction product thus obtained, a product obtained by cutting a low molecular region by performing a treatment such as fractionation can also be used.
In the present invention, a novolak resin obtained by condensation of plural types of mixed phenols selected from m-cresol, p-cresol, o-cresol, 2,5-xylenol, and 3,5-xylenol phenols with formaldehyde Is preferred. In this case, the novolak resin preferably has a weight average molecular weight of 2,000 to 20,000, more preferably 2,500 to 15,000 in terms of polystyrene by gel permeation chromatography (GPC) method (solvent tetrahydrofuran). A novolak resin in the range is preferably used.

式中、ｚは１〜３から選ばれる自然数である。ＲｎはＲｓＯＨ又はＲｓＯＲｔで表され、Ｒｓは、炭素数１〜６の直鎖状、分岐状又は環状構造を有するアルキル基から選ぶことができ、メチル基もしくはエチル基が好適に用いられる。Ｒｔについては、Ｒｓと独立して、炭素数１〜６の直鎖状、分岐状又は環状構造を有するアルキル基から選ぶことができ、メチル基もしくはエチル基が好適に用いられる。
好ましい化合物は、（Ｉ）の単位を１〜１０個、更に好ましくは２〜５個を、炭素又は炭化水素結合を介して有する構造である。
なお、（Ｂ）成分のヒドロキシ化合物の重量平均分子量は１８０〜１０，０００が好ましく、より好ましくは３００〜１０，０００である。 (B) About the aromatic hydroxy compound containing an alkoxyalkyl group or a hydroxyalkyl group, the aromatic hydroxy compound which has a C2-C12 alkoxyalkyl group or a C1-C12 hydroxyalkyl group is mentioned. In this case, as an alkoxy group, a C1-C6 thing is preferable. As such a compound, an aromatic hydroxy compound having a structure represented by the following general formula (I) can be suitably used. However, a wavy line shows that it is a coupling | bond part with an adjacent repeating unit.

In the formula, z is a natural number selected from 1 to 3. Rn is represented by RsOH or RsORt, and Rs can be selected from alkyl groups having a linear, branched or cyclic structure having 1 to 6 carbon atoms, and a methyl group or an ethyl group is preferably used. Rt can be selected from alkyl groups having a linear, branched or cyclic structure having 1 to 6 carbon atoms independently of Rs, and a methyl group or an ethyl group is preferably used.
A preferred compound has a structure having 1 to 10, more preferably 2 to 5 units of (I) via a carbon or hydrocarbon bond.
In addition, as for the weight average molecular weight of the hydroxy compound of (B) component, 180-10,000 are preferable, More preferably, it is 300-10,000.

Although a specific example is given below, it is not limited to these. Me represents a methyl group.

  In the present invention, the amount of (B) the aromatic hydroxy compound containing an alkoxyalkyl group or hydroxyalkyl group is 3 to 50 parts by mass, preferably 5 to 40 parts per 100 parts by mass of (A) the alkali-soluble novolac resin. Part by mass, more preferably 7 to 35 parts by mass. These may be used alone or in combination of two or more. When the component (B) is less than 3 parts by mass, curing may be insufficient and the effects of the present invention may not be obtained. When the component exceeds 50 parts by mass, notches generated in the vicinity of the substrate become large, and pattern formation is difficult. It can be difficult.

  (C) As quinonediazide sulfonic acid ester photosensitizers, known naphthoquinone diazide sulfonic acid ester of 2,3,4-trihydroxybenzophenone, naphthoquinone diazide sulfonic acid ester of 2,3,4,4′-tetrahydroxybenzophenone, The compound represented by the following general formula (1) or (2) or trihydroxy is not limited to those produced industrially, such as naphthoquinonediazide sulfonic acid ester of 2,2 ′, 4,4′-tetrahydroxybenzophenone Among the compounds selected from benzophenone or tetrahydroxybenzophenone, it can be used in the form of adding a photosensitizer in which one or a plurality of hydroxy groups have hydrogen atoms substituted with naphthoquinonediazidosulfonyl groups.

（式中、ｊは１又は２、ｋ、ｍ、ｐはそれぞれ０〜３、ｎは１〜４、ｑは１〜３、ｒは２又は３の整数で、ｍ＋ｐ＋ｎ≦６、ｋ＋ｑ≦５、ｍ＋ｑ≦５である。）

(Wherein j is 1 or 2, k, m and p are 0 to 3, n is 1 to 4, q is 1 to 3, r is an integer of 2 or 3, and m + p + n ≦ 6, k + q ≦ 5, m + q ≦ 5.)

Especially, it is preferable on lift-off pattern formation that 65 mol% or more of phenolic hydroxy groups are esterified with the naphthoquinone diazide sulfonic acid.
In this invention, (A) As for the compounding quantity of the photosensitive component (C) with respect to 100 mass parts of alkali-soluble novolak resin, 10-55 mass parts is preferable, More preferably, it is 25-50 mass parts, Most preferably, it is 30-45 mass. Part. These may be used alone or in combination of two or more. When the component (C) is less than 10 parts by mass, the unexposed part dissolves in the developing solution during development, and a phenomenon of film slippage in which the film thickness becomes thin may occur. Is greatly deteriorated, and may become unrealistic sensitivity, which is not preferable.

  The (D) photoacid generator in the positive lift-off resist composition used in the present invention may be any compound as long as it generates an acid by high energy ray irradiation. Suitable photoacid generators include sulfonium salts, iodonium salts, sulfonyldiazomethane, N-sulfonyloxyimide type photoacid generators, and the like. Although described in detail below, these can be used alone or in admixture of two or more.

  A sulfonium salt is a salt of a sulfonium cation and a sulfonate. Examples of the sulfonium cation include triphenylsulfonium, (4-tert-butoxyphenyl) diphenylsulfonium, bis (4-tert-butoxyphenyl) phenylsulfonium, tris (4-tert-butoxyphenyl) sulfonium, (3-tert- Butoxyphenyl) diphenylsulfonium, bis (3-tert-butoxyphenyl) phenylsulfonium, tris (3-tert-butoxyphenyl) sulfonium, (3,4-ditert-butoxyphenyl) diphenylsulfonium, bis (3,4-di tert-butoxyphenyl) phenylsulfonium, tris (3,4-ditert-butoxyphenyl) sulfonium, diphenyl (4-thiophenoxyphenyl) sulfonium, (4-tert Butoxycarbonylmethyloxyphenyl) diphenylsulfonium, tris (4-tert-butoxycarbonylmethyloxyphenyl) sulfonium, (4-tert-butoxyphenyl) bis (4-dimethylaminophenyl) sulfonium, tris (4-dimethylaminophenyl) sulfonium , 2-naphthyldiphenylsulfonium, dimethyl 2-naphthylsulfonium, 4-hydroxyphenyldimethylsulfonium, 4-methoxyphenyldimethylsulfonium, trimethylsulfonium, 2-oxocyclohexylcyclohexylmethylsulfonium, trinaphthylsulfonium, tribenzylsulfonium, etc. Examples of the sulfonate include trifluoromethane sulfonate and nonafluorobutane sulfonate. , Heptadecafluorooctane sulfonate, 2,2,2-trifluoroethane sulfonate, pentafluorobenzene sulfonate, 4-trifluoromethylbenzene sulfonate, 4-fluorobenzene sulfonate, toluene sulfonate, benzene sulfonate, 4- (4-toluenesulfonyl) Oxy) benzenesulfonate, naphthalenesulfonate, camphorsulfonate, octanesulfonate, dodecylbenzenesulfonate, butanesulfonate, methanesulfonate, and the like, and sulfonium salts of these combinations.

  An iodonium salt is a salt of an iodonium cation and a sulfonate. Examples of the iodonium cation include aryliodonium cations such as diphenyliodonium, bis (4-tert-butylphenyl) iodonium, 4-tert-butoxyphenylphenyliodonium, 4-methoxyphenylphenyliodonium, and the sulfonates include, for example, , Trifluoromethanesulfonate, nonafluorobutanesulfonate, heptadecafluorooctanesulfonate, 2,2,2-trifluoroethanesulfonate, pentafluorobenzenesulfonate, 4-trifluoromethylbenzenesulfonate, 4-fluorobenzenesulfonate, toluenesulfonate, benzene Sulfonate, 4- (4-toluenesulfonyloxy) benzenesulfonate, naphthalenesulfonate, Emissions Fur sulfonate, octane sulfonate, dodecylbenzene sulfonate, butane sulfonate, methanesulfonate and the like, and iodonium salts of these combinations thereof.

  Examples of the sulfonyldiazomethane include bis (ethylsulfonyl) diazomethane, bis (1-methylpropylsulfonyl) diazomethane, bis (2-methylpropylsulfonyl) diazomethane, bis (1,1-dimethylethylsulfonyl) diazomethane, and bis (cyclohexylsulfonyl). ) Diazomethane, bis (perfluoroisopropylsulfonyl) diazomethane, bis (phenylsulfonyl) diazomethane, bis (4-methylphenylsulfonyl) diazomethane, bis (2,4-dimethylphenylsulfonyl) diazomethane, bis (2-naphthylsulfonyl) diazomethane, 4-methylphenylsulfonylbenzoyldiazomethane, tert-butylcarbonyl-4-methylphenylsulfonyldiazomethane, 2-naphthylsulfonyl Benzoyl diazomethane, 4-methylphenyl sulfonyl-2-naphthoyl diazomethane, methylsulfonyl benzoyl diazomethane, and a bis-sulfonyl diazomethane and sulfonyl carbonyl diazomethane such as tert- butoxycarbonyl-4-methylphenyl sulfonyl diazomethane.

  Examples of the N-sulfonyloxyimide photoacid generator include succinimide, naphthalene dicarboxylic imide, phthalic imide, cyclohexyl dicarboxylic imide, 5-norbornene-2,3-dicarboxylic imide, 7-oxabicyclo [ 2.2.1] Imido skeletons such as -5-heptene-2,3-dicarboxylic imide and, for example, trifluoromethane sulfonate, nonafluorobutane sulfonate, heptadecafluorooctane sulfonate, 2,2,2-trifluoroethane Sulfonate, pentafluorobenzene sulfonate, 4-trifluoromethylbenzene sulfonate, 4-fluorobenzene sulfonate, toluene sulfonate, benzene sulfonate, naphthalene sulfonate, camphor sulfonate, octane sulfonate DOO, dodecylbenzene sulfonate, butane sulfonate, compounds of the combination, such as methane sulfonates.

Examples of the benzoin sulfonate photoacid generator include benzoin tosylate, benzoin mesylate, and benzoin butane sulfonate.
Examples of pyrogallol trisulfonate photoacid generators include pyrogallol, phloroglysin, catechol, resorcinol, and all hydroquinone hydroxyl groups such as trifluoromethanesulfonate, nonafluorobutanesulfonate, heptadecafluorooctanesulfonate, 2, 2 , 2-trifluoroethanesulfonate, pentafluorobenzenesulfonate, 4-trifluoromethylbenzenesulfonate, 4-fluorobenzenesulfonate, toluenesulfonate, benzenesulfonate, naphthalenesulfonate, camphorsulfonate, octanesulfonate, dodecylbenzenesulfonate, butanesulfonate, methane Examples thereof include compounds substituted with sulfonate.

  Examples of the nitrobenzyl sulfonate photoacid generator include 2,4-dinitrobenzyl sulfonate, 2-nitrobenzyl sulfonate, and 2,6-dinitrobenzyl sulfonate. Examples of the sulfonate include trifluoromethane sulfonate and nonafluoro. Butanesulfonate, heptadecafluorooctanesulfonate, 2,2,2-trifluoroethanesulfonate, pentafluorobenzenesulfonate, 4-trifluoromethylbenzenesulfonate, 4-fluorobenzenesulfonate, toluenesulfonate, benzenesulfonate, naphthalenesulfonate, camphorsulfonate , Octanesulfonate, dodecylbenzenesulfonate, butanesulfonate, methanesulfonate, and the like. A compound in which the nitro group on the benzyl side is replaced with a trifluoromethyl group can also be used.

  Examples of the sulfone-type photoacid generator include, for example, bis (phenylsulfonyl) methane, bis (4-methylphenylsulfonyl) methane, bis (2-naphthylsulfonyl) methane, 2,2-bis (phenylsulfonyl) propane, 2,2-bis (4-methylphenylsulfonyl) propane, 2,2-bis (2-naphthylsulfonyl) propane, 2-methyl-2- (p-toluenesulfonyl) propiophenone, 2- (cyclohexylcarbonyl)- Examples include 2- (p-toluenesulfonyl) propane and 2,4-dimethyl-2- (p-toluenesulfonyl) pentan-3-one.

  Examples of glyoxime derivative-type photoacid generators include bis-o- (p-toluenesulfonyl) -α-dimethylglyoxime, bis-o- (p-toluenesulfol) -α-diphenylglyoxime, bis- o- (p-toluenesulfonyl) -α-dicyclohexylglyoxime, bis-o- (p-toluenesulfonyl) -2,3-pentanedione glyoxime, bis-o- (p-toluenesulfonyl) -2-methyl- 3,4-pentanedione glyoxime, bis-o- (n-butanesulfonyl) -α-dimethylglyoxime, bis-o- (n-butanesulfonyl) -α-diphenylglyoxime, bis-o- (n- Butanesulfonyl) -α-dicyclohexylglyoxime, bis-o- (n-butanesulfonyl) -2,3-pentanediolio Shim, bis-o- (n-butanesulfonyl) -2-methyl-3,4-pentanedione glyoxime, bis-o- (methanesulfonyl) -α-dimethylglyoxime, bis-o- (trifluoromethanesulfonyl) -Α-dimethylglyoxime, bis-o- (1,1,1-trifluoroethanesulfonyl) -α-dimethylglyoxime, bis-o- (tert-butanesulfonyl) -α-dimethylglyoxime, bis-o -(Perfluorooctanesulfonyl) -α-dimethylglyoxime, bis-o- (cyclohexylsulfonyl) -α-dimethylglyoxime, bis-o- (benzenesulfonyl) -α-dimethylglyoxime, bis-o- (p -Fluorobenzenesulfonyl) -α-dimethylglyoxime, bis-o- (p-tert-butyl) Nzensuruhoniru)-.alpha.-dimethylglyoxime, bis-o-(xylene sulfonyl)-.alpha.-dimethylglyoxime, bis-o-(camphorsulfonyl)-.alpha.-dimethylglyoxime, and the like.

  As for the anion of the acid to be generated, an anion having no volatility or an anion having extremely low diffusibility is generally selected. In this case, suitable anions are, for example, benzenesulfonate anion, toluenesulfonate anion, 4- (4-toluenesulfonyloxy) benzenesulfonate anion, pentafluorobenzenesulfonate anion, 2,2,2-trifluoroethane. A sulfonate anion, a nonafluorobutane sulfonate anion, a heptadecafluorooctane sulfonate anion, and a camphor sulfonate anion.

  Among the photoacid generators, naphthalimidyl, sulfonyloxyimino, and the like can be suitably used when the i-line, g-line, or broadband light of a mercury lamp is used as the first high-energy beam. Similarly, when a light source having a short wavelength of 300 nm or less, such as a KrF excimer laser or a mercury 254 nm line, is used as the first high energy line, sulfonyloxyimino, bissulfonyldiazomethane, or the like is preferably used. it can.

The addition amount of the photoacid generator is 0 to 10 parts by mass with respect to 100 parts by mass of the (A) alkali-soluble novolak resin, and 0.0001 to 10 parts by mass, preferably 0.002 to 100 parts by mass. 5 parts by mass. The photoacid generators can be used alone or in combination of two or more.
If the photoacid generator exceeds 10 parts by mass, the storage stability may be deteriorated, which is not preferable.

In the present invention, the (E) aromatic hydroxy compound having a weight average molecular weight of 180 to 800, which is a further dissolution promoting component, preferably has 2 to 15 benzene rings, more preferably 3 to 10, particularly Preferably the number is 3 to 7, and the ratio of the number of hydroxy groups to the number of benzene rings is preferably 0.4 to 3.0, more preferably 0.5 to 2.0, most preferably 0.6. ~ 1.5. When the number of hydroxy groups is small, the dissolution rate with respect to the alkaline developer is reduced, and a desired slit size cannot be obtained. When the number is too large, the adhesion may be lowered. In addition, an aromatic hydroxy compound having a weight average molecular weight exceeding 800 is not suitable because the effect of the present invention is lowered. Specifically, when an aromatic hydroxy compound having a weight average molecular weight exceeding 800 is blended, the target undercut becomes small, and the effect of the present invention cannot be obtained. In the present invention, a part of the hydroxy group may be acylated. In that case, acylation can be carried out by a conventional method. In addition, the case where (E) component is the hydroxy compound in the said (C) component is remove | excluded.
In this case, as the aromatic hydroxy compound of the component (E), compounds represented by the following formulas (1) and (2) and further a formula (5) are preferably used.

（式中、ｊは１又は２、ｋ、ｍ、ｐはそれぞれ０〜３、ｎは１〜４、ｑは１〜３、ｒは２又は３の整数で、ｍ＋ｐ＋ｎ≦６、ｋ＋ｑ≦５、ｍ＋ｑ≦５である。）

［（式中、Ｒａ、Ｒｂ、Ｒｃ、Ｒｄ、Ｒｅ、Ｒｆはそれぞれ独立して水素原子、メチル基、又は下記式（６）で示される基であって、Ｒａ、Ｒｂ、Ｒｃの少なくとも一つ及びＲｄ、Ｒｅ、Ｒｆの少なくとも一つはベンゼン環にヒドロキシ基が付加した構造を有する。ｘ、ｙはそれぞれ０〜３の整数である。）

（式中、ｖ、ｗはそれぞれ０〜３の整数である。）］

(Wherein j is 1 or 2, k, m and p are 0 to 3, n is 1 to 4, q is 1 to 3, r is an integer of 2 or 3, and m + p + n ≦ 6, k + q ≦ 5, m + q ≦ 5.)

[In the formula, Ra, Rb, Rc, Rd, Re, and Rf are each independently a hydrogen atom, a methyl group, or a group represented by the following formula (6), and at least one of Ra, Rb, and Rc. And at least one of Rd, Re, and Rf has a structure in which a hydroxy group is added to a benzene ring, and x and y are each an integer of 0 to 3.)

(Wherein v and w are each an integer of 0 to 3)]

In this invention, (E) aromatic hydroxy compound may be used independently and may combine 2 or more types. The blending amount is preferably 0 to 70 parts by mass with respect to 100 parts by mass of the (A) alkali-soluble novolac resin, and when the component (E) is added, it is 2 to 70 parts by mass, more preferably 5 to 60 parts. Part by mass, particularly preferably 10 to 50 parts by mass.
When the component (E) exceeds 70 parts by mass, the notch becomes excessively large and pattern collapse occurs, or the phenomenon of film slippage in which the film thickness after development becomes significantly thinner than the film thickness after soft baking occurs. There is.

［式中、Ｒ¹は独立に、酸価３０〜１５０ｍｇＫＯＨ／ｇを示す範囲において、水素原子、炭素数１〜４のアルキル基、炭素数１〜４のヒドロキシアルキル基、炭素数１〜８のアシル基又は下記構造式（４）

（式中、Ｒ’は炭素数１〜６のアルキレン基、フェニレン基又はシクロヘキシレン基である。）
で表される有機基であり、かつＲ¹中の上記式（４）で表される有機基の割合が単位グルコース環あたり平均２〜３０モル％であり、ｓは２〜１０，０００の整数である。］
で表されるアルカリ可溶性セルロースを含有するものである。 The alkali-soluble cellulose as the component (F) has the following structural formula (3)

[In the formula, R ¹ is independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms, or an alkyl group having 1 to 8 carbon atoms in a range showing an acid value of 30 to 150 mgKOH / g. Acyl group or the following structural formula (4)

(In the formula, R ′ represents an alkylene group having 1 to 6 carbon atoms, a phenylene group, or a cyclohexylene group.)
The ratio of the organic group represented by the above formula (4) in R ¹ is an average of 2 to 30 mol% per unit glucose ring, and s is an integer of 2 to 10,000 It is. ]
It contains an alkali-soluble cellulose represented by

  This alkali-soluble cellulose does not dissociate when the introduced carboxyalkyl group is acidic, and itself is hydrophobic and shows acid resistance, but dissociates in a weakly acidic to neutral region, so it dissolves in an aqueous or alkaline solution. Moreover, it becomes a resin binder transparent to the exposure light source. By containing this alkali-soluble cellulose, the sensitivity becomes high for the above reasons, and the undercut can be increased.

In the formula (3), when the acid value is less than 30 mgKOH / g, the effect of improving sensitivity and promoting undercut is small, and when it is more than 150 mgKOH / g, the amount of remaining film may be reduced after pattern formation.
R ¹ is independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms, or an acyl group having 1 to 8 carbon atoms in a range showing an acid value of 30 to 150 mgKOH / g. or an organic group represented by the structural formula (4), and an average 2 to 30 mol% proportion per unit glucose ring of the organic group represented by the above formula in R ¹ (4).

R ¹ is, for example, a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group or the like, an alkyl group having 1 to 4 carbon atoms, a hydroxymethyl group, a hydroxyethyl group Group, C1-C4 hydroxyalkyl groups such as 2-hydroxypropyl group, C1-C8 acyl groups such as acetyl group, propionyl group and butyryl group. Moreover, as R 'in Formula (4), C1-C6 alkylene groups, such as ethylene group, a phenylene group, or a cyclohexylene group is mentioned.

The ratio of the organic group represented by the above formula (4) in R ¹ is 2-30 mol% on average per unit glucose ring, but 5-25 mol% is particularly preferable. When the proportion of the organic group represented by the above formula (4) is less than 2 mol%, the solubility in an alkali solution during development is inferior, and when it exceeds 30 mol%, the solubility in an alkali solution becomes too large. Cause film loss after development. Moreover, s is an integer of 2 to 10,000, and 100 to 5,000 is particularly preferable.

  The blending amount of the alkali-soluble cellulose (F) represented by the formula (3) is 0 to 30 parts by weight with respect to 100 parts by weight of the alkali-soluble novolak resin as the component (A). It is particularly preferable to blend 5 to 20 parts by mass. If it is less than 2 parts by mass, the effect of promoting undercut is small, and a desired undercut size is difficult to obtain. On the other hand, when it exceeds 30 parts by mass, the solubility of the composition in the aqueous alkaline solution increases, the residual film property is inferior, the undercut becomes too large, and pattern formation becomes difficult.

In the present invention, in addition to the above-mentioned components, a surfactant used for improving coating properties can be added. As the surfactant, various nonionic, fluorine and silicone surfactants can be used. Examples of the surfactant include, but are not limited to, polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene olein ether, Polyoxyethylene alkyl aryl ethers such as oxyethylene octylphenol ether and polyoxyethylene nonylphenol ether, polyoxyethylene polyoxypropylene block copolymers, sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate , Polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan Non-ionic surfactants of polyoxyethylene sorbitan fatty acid esters such as nostearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate, Ftop EF301, EF303, EF352 (manufactured by Tochem Products), Mega Fuck F171, F172, F173 (manufactured by DIC Corporation), Florard FC430, FC431 (manufactured by Sumitomo 3M Corporation), Asahi Guard AG710, Surflon S-381, S-382, SC101, SC102, SC103, SC104, SC105, SC106, Fluorosurfactants such as Surfynol E1004, KH-10, KH-20, KH-30, KH-40 (Asahi Glass Co., Ltd.), organosiloxane polymer KP341, X- 0-092, (manufactured by Shin-Etsu Chemical Co., Ltd.) X-70-093, acrylic acid or methacrylic acid Polyflow No. 75, no. 95 (manufactured by Kyoeisha Chemical Co., Ltd.). These can be used alone or in combination of two or more.
The addition amount of the surfactant of the present invention is 2 parts by mass or less, preferably 1 part by mass or less based on 100 parts by mass of the (A) alkali-soluble novolak resin.

  Furthermore, the positive lift-off resist composition of the present invention includes an alkali-soluble resin such as polyhydroxystyrene, 2-benzeneazo-4-methylphenol, 4-hydroxy-4′-dimethyl, as long as the object of the present invention is not impaired. Various compounding agents such as an azo compound such as aminoazobenzene, a dye such as curcumin, and a pigment can be added.

Examples of the solvent used in the present invention include butyl acetate, amyl acetate, cyclohexyl acetate, 3-methoxybutyl acetate, methyl ethyl ketone, methyl amyl ketone, cyclohexanone, cyclopentanone, 3-ethoxyethyl propionate, 3-ethoxymethyl propionate. Pionate, 3-methoxymethyl propionate, methyl acetoacetate, ethyl acetoacetate, diacetone alcohol, methyl pyruvate, ethyl pyruvate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether propionate, Propylene glycol monoethyl ether propionate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol mono Tyl ether, diethylene glycol monoethyl ether, 3-methyl-3-methoxybutanol, N-methylpyrrolidone, dimethyl sulfoxide, γ-butyrolactone, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate, methyl lactate, lactic acid Examples include, but are not limited to, ethyl, propyl lactate, and tetramethylene sulfone. Particularly preferred are acetic acid alkyl esters and lactic acid alkyl esters. These solvents may be used alone or in combination of two or more.
In addition, although the usage-amount of a solvent is selected suitably, 70-10,000 mass parts is suitable with respect to 100 mass parts of alkali-soluble novolak resin (A) normally.

The resist pattern forming method in the lift-off process using the positive lift-off resist composition of the present invention is not particularly limited as long as it is a regular method. In addition to Si, SiO ₂ , SiN, SiON, TiN, WSi, BPSG, SOG, and other substrates, Au, Ti, W, Cu, Ni—Fe, Ta, Zn, Co, Pb, and other metal substrates, organic antireflection coatings It is applied to a substrate such as spin coat, roll coat, flow coat, dip coat, spray coat, doctor blade coat, etc., so that it has a desired film thickness, and is heated to 60 to 150 ° C. on a hot plate. Pre-bake for 1 to 10 minutes, preferably 80 to 120 ° C. for 1 to 5 minutes. Next, the target pattern is exposed through a predetermined mask at a light source selected from ultraviolet rays, far ultraviolet rays, electron beams, and the like, preferably at an exposure wavelength of 300 nm or more. The exposure is preferably performed so that the exposure amount is about 1 to 1,000 mJ / cm ² , preferably about 10 to 800 mJ / cm ² . Post exposure baking (PEB) is performed on a hot plate at 60 to 150 ° C. for 1 to 5 minutes, preferably 80 to 120 ° C. for 1 to 3 minutes.
Further, 0.1 to 5% by mass, preferably 2 to 3% by mass of an aqueous developer solution such as tetramethylammonium hydroxide (TMAH) is used for 0.1 to 60 minutes, preferably 0.5 to 10%. The target pattern is formed on the substrate by developing for a minute by a conventional method such as a dip method, a paddle method, or a spray method.

Next, the obtained substrate can be irradiated with a second ultraviolet ray and / or subjected to a heat treatment. In the case of irradiating the second ultraviolet ray, the exposure amount can be selected in the range of 30 to 3,000 seconds at 10 to 800 mW / cm ² . At this time, if the irradiation amount is too small, the effects of the present invention cannot be obtained, and the pattern is likely to be deformed when forming the metal film. Since (C) quinonediazidosulfonic acid ester photosensitizer is likely to foam due to decomposition, it is not preferable. Under the present circumstances, it can also heat during 2nd ultraviolet irradiation, In that case, it can select from the temperature range of 50-150 degreeC. At that time, the heating temperature may be constant or changed. After performing this second ultraviolet irradiation, heat treatment may be performed at 120 to 220 ° C. for 5 to 120 minutes as necessary. In addition, when 2nd ultraviolet irradiation is not performed, it is necessary to perform the heat processing for 5-120 minutes at this temperature of 120-220 degreeC. As for this heat treatment, the substrate may be put into a heating apparatus that has already reached a predetermined temperature, or it may be gradually heated from room temperature and finally heat-treated at a predetermined temperature.
Finally, after forming a metal film by sputtering, vapor deposition, etc., if the resist pattern and the metal film on the pattern are peeled together to form a metal wiring on the substrate, the metal pattern is formed on the substrate. A metal wiring board can be manufactured.

  EXAMPLES Hereinafter, although a synthesis example, an Example, and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example.

[Synthesis Example 1] Synthesis of novolak resin In a three-necked flask equipped with a stirrer, a condenser and a thermometer, 75.7 g (0.7 mol) of p-cresol, 32.5 g (0.3 mol) of m-cresol, 37 masses. % Aqueous solution of formaldehyde 52.3 g (0.549 mol) and oxalic acid dihydrate 0.30 g (2.40 × 10 ⁻³ mol) as a polycondensation catalyst were charged, the flask was immersed in an oil bath, and the internal temperature was 100 The temperature was maintained at 0 ° C. and polycondensation was performed for 1 hour. After completion of the reaction, 500 mL of MIBK (methyl isobutyl ketone) was added and stirred for 30 minutes. Then, the aqueous layer was separated, and the product extracted into the MIBK layer was washed with 300 mL of pure water five times and separated to obtain an evaporator. And a vacuum strip at 150 ° C. at 4 mmHg to obtain a novolak resin (87 g) having a weight average molecular weight (Mw) of 8,000. In addition, the measurement of Mw uses the Tosoh Co., Ltd. product, GPC column (G-2000H6 * 2, G-3000H6 * 1, G-4000H6 * 1), and flow volume 1.5mL / min. , Elution solvent THF, column temperature 40 ° C.

[Examples 1-8, Comparative Examples 1-5]
100 parts by mass of the alkali-soluble novolak resin obtained in Synthesis Example 1 and 66 mol% of 2,3,4-trihydroxybenzophenone esterified with naphthoquinonediazide-5-sulfonic acid (Toyo Gosei Co., Ltd.) NT-200) (II), an aromatic hydroxy compound containing an alkoxyalkyl group, a compound (III) represented by the following formula (7) and a polymer compound having a repeating unit represented by the formula (8) ( IV), compound (VIII) represented by the formula (10) as an aromatic hydroxy compound containing a hydroxyalkyl group, bis (cyclohexylsulfonyl) diazomethane (V) as a photoacid generator, and a fragrance represented by the following formula (9) Group hydroxy compound (VI), alkali-soluble cellulose A (manufactured by Shin-Etsu Chemical Co., Ltd.) Roxypropylmethylcellulose phthalate: acid value 92 mg KOH / g, containing 20 mol% of carboxybenzoyl group) (VII) was mixed at the compounding ratio shown in Table 1, and X-70-093 (Shin-Etsu Chemical Co., Ltd.) was used as a surfactant to improve coatability. 0.1 parts by mass of (organosiloxane polymer) was added, and the mixture was made into a solution with 200 parts by mass of a solvent having a mixture ratio of ethyl lactate and butyl acetate of 85 parts by mass and 15 parts by mass, and then a 0.2 μm membrane. Filtration through a filter prepared a positive lift-off resist solution. In Comparative Examples 3, 4, and 5, compounds represented by the following formulas (11) and (12) are used as (IX) and (X), respectively, instead of the aromatic hydroxy compound containing an alkoxyalkyl group. Using.

The obtained resist solution was applied onto a Si substrate and soft baked at 100 ° C. for 120 seconds on a hot plate to form a 3 μm resist film. Next, exposure with an i-line stepper through a reticle (Nikon, NA = 0.5), heating at 120 ° C. for 90 seconds, and development with an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution for 100 seconds Then, it was rinsed with pure water for 30 seconds and dried. Thereafter, treatment was performed at 80 mW / cm ² , 60 seconds, and 50 ° C. using a UV curing device (UMA-802-HC551) manufactured by USHIO INC. After this treatment, in order to confirm the heat resistance, heat treatment was performed in an oven at 220 ° C./1 hour and compared with the pattern shape after development. In addition, about the pattern shape, the shape of the cross section was observed with the electron microscope (made by Hitachi), and the amount of horizontal cuts (one side) shown in FIG. 1 was measured. The results are shown in Table 2. In FIG. 1, A: line width, B: ground contact width with substrate, C: undercut width (A = B + 2C), and the maximum value of the cut height is H. About the width | variety of A, B, and H, the location of the said location was confirmed on the screen of SEM, and the notch length of the location was measured.

Further, as Example 8, the composition of Example 4 was used until the development treatment, and then the temperature was raised from room temperature to 150 ° C. using an oven without UV irradiation. After heat treatment for a period of time, it was allowed to cool to room temperature. Thereafter, a heat treatment at 220 ° C./1 hour was performed and compared with the pattern shape after development.
According to the present invention, it is possible to obtain a lift-off shape without pattern deformation even at a high temperature of 120 ° C. or higher, particularly 130 ° C. or higher.

A Line width B Ground contact width C Undercut width H Maximum notch height from the board

Claims (10)

(A) an alkali-soluble novolak resin,
(B) an aromatic hydroxy compound containing a methoxymethyl group or a hydroxymethyl group,
(C) a quinonediazide sulfonic acid ester photosensitizer , and
(E) A positive lift-off resist composition comprising an aromatic hydroxy compound not containing an alkoxyalkyl group and a hydroxyalkyl group having a weight average molecular weight of 180 to 800 .   2. The positive lift-off resist composition according to claim 1, wherein the aromatic hydroxy compound containing a methoxymethyl group or a hydroxymethyl group as component (B) has a weight average molecular weight of 300 to 10,000.   The aromatic hydroxy compound containing a methoxymethyl group or a hydroxymethyl group as the component (B) contains 3 to 50 parts by mass with respect to 100 parts by mass of the (A) alkali-soluble novolac resin. The positive lift-off resist composition described. (B) The positive lift-off resist composition according to any one of claims 1 to 3, wherein the aromatic hydroxy compound containing a methoxymethyl group or a hydroxymethyl group is at least one selected from the following formulas: object.

  The positive lift-off resist composition according to any one of claims 1 to 4, further comprising (D) a photoacid generator. The aromatic hydroxy compound of component (E) is represented by the following formula (1), (2) or (5)

(Wherein j is 1 or 2, k, m and p are 0 to 3, n is 1 to 4, q is 1 to 3, r is an integer of 2 or 3, and m + p + n ≦ 6, k + q ≦ 5, m + q ≦ 5.)

[In the formula, Ra, Rb, Rc, Rd, Re, and Rf are each independently a hydrogen atom, a methyl group, or a group represented by the following formula (6), and at least one of Ra, Rb, and Rc. And at least one of Rd, Re, and Rf has a structure in which a hydroxy group is added to a benzene ring, and x and y are each an integer of 0 to 3.)

(Wherein v and w are each an integer of 0 to 3)]
The positive lift-off resist composition according to any one of claims 1 to 5, wherein the positive lift-off resist composition is selected from the compounds represented by the formula (1), wherein 2 to 70 parts by mass are blended with respect to 100 parts by mass of the alkali-soluble novolak resin (A). Furthermore, (F) alkali-soluble cellulose is contained, The positive type lift-off resist composition of any one of Claims 1-6 characterized by the above-mentioned. The alkali-soluble cellulose as component (F) has the following structural formula (3)

[In the formula, R ¹ is independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms, or an alkyl group having 1 to 8 carbon atoms in a range showing an acid value of 30 to 150 mgKOH / g. Acyl group or the following structural formula (4)

(In the formula, R ′ represents an alkylene group having 1 to 6 carbon atoms, a phenylene group, or a cyclohexylene group.)
The ratio of the organic group represented by the above formula (4) in R ¹ is an average of 2 to 30 mol% per unit glucose ring, and s is an integer of 2 to 10,000 It is. ]
The positive lift-off resist composition according to claim 7, which is represented by: A step (a) of applying the resist composition according to any one of claims 1 to 8 to a substrate, a step (b) of exposing to radiation or an electron beam through a photomask after the heat treatment, and then necessary The step (c) of developing using a developer after heat treatment according to the step, and then the step (d) of irradiating the obtained resist pattern with a second radiation and / or heat treatment at 120 to 220 ° C. And a step (e) of performing patterning. After the step (d) and / or (e), a metal layer is formed on the entire resist pattern formed on the substrate, and then the resist pattern and the metal layer formed on the pattern are peeled off to form the substrate. The pattern forming method according to claim 9 , wherein a metal pattern is formed on the substrate.

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