JP2014219469A - Pattern formation method and support provided with resin structure having undercut shape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a support having a resin structure characterized by a lift-off shape with a large notch height.SOLUTION: A pattern formation method includes (1) a step of applying a photosensitive resin composition comprising ingredients (A) to (D) to a support, (2) a step of heating the support applied with the composition, (3) a step of irradiating the obtained film of the composition with radiation rays of wavelengths of 300-600 nm and (4) a step of forming a pattern by development with an alkaline developer. (A) An alkali-soluble novolak resin; (B) a photosensitizer based on a quinone diazide sulfonate ester; (C) an aromatic hydroxy compound of a formula weight of 240-1,500; and (D) an organic solvent. In the step (4), development is carried out for a development time 5-15 times the shortest development time yield a ratio of the line width to the space width of 1:1 when a line-and-space pattern is used so as to obtain a pattern shape and forming a resin structure having an undercut shape in the bottom part of the pattern shape.

Description

  The present invention relates to a pattern forming method for forming a support having a resin structure having an undercut shape and the support.

  A lift-off method is known as means for forming various metal wiring patterns such as aluminum, copper, and tantalum on a support used in a semiconductor. In the lift-off method, for example, a resist composition is applied on a support, exposed through a mask, developed to form a resist pattern on a substrate, and then a metal film is formed on the resist pattern and the metal support. It is formed by sputtering, vapor deposition or the like, and then the resist pattern and the metal film on the pattern are peeled together to form 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 in the lower part of the resist pattern (a support grounding portion).

  Examples of conventional reports having such a shape include JP-A-8-69111 (Patent Document 1) and JP-A-2012-108415 (Patent Document 2). In particular, Japanese Patent Application Laid-Open No. 2012-108415 reports a method of generating an undercut with a large depth of cut while suppressing film slippage by adding alkali-soluble cellulose. However, the metal film formation amount used in the manufacture of MEMS (Micro Electro-Mechanical System) elements, etc. is a material that can form a larger cut height in order to perform a thick film formation compared to the conventional semiconductor manufacturing process, or Although a proposal for a process has been awaited, the height of the cut cannot be made to a desired shape only by changing the composition of the current positive lift-off resist.

JP-A-8-69111 JP 2012-108415 A

  The present invention has been made in view of the above circumstances, and forms a support having a resin structure having a lift-off shape with a large cut height while using a single-layer positive lift-off resist composition as a photosensitive resin composition. An object of the present invention is to provide a pattern forming method and the support.

  As a result of intensive studies to achieve the above object, the present inventor has (A) an alkali-soluble novolak resin, (B) a quinonediazide sulfonate ester photosensitizer, and (C) a fragrance having a formula weight of 240 to 1,500. The present inventors have found that by using a composition containing a group hydroxy compound and (D) an organic solvent and performing excessive development, the height of the cut can be effectively increased.

（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である。）
［４］ （Ｃ）成分の芳香族ヒドロキシ化合物が、下記式（１），（２），（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下記式（６）においてｗが１〜３の整数である構造を有する。式中、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、該（Ｃ）成分を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］〜［３］のいずれかに記載のパターン形成方法。
［５］ 前記感光性樹脂組成物が、更に（Ｅ）アルカリ可溶性セルロース樹脂を含み、その含有量がアルカリ可溶性ノボラック樹脂（Ａ）１００質量部に対して３〜３０質量部である［１］〜［４］のいずれかに記載のパターン形成方法。
［６］ ［１］〜［５］のいずれかに記載のパターン形成方法により形成したアンダーカット形状を有する樹脂構造体からなる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パターン形成方法。
［７］ ［１］〜［５］のいずれかに記載のパターン形成方法により形成されたアンダーカット形状を有する樹脂構造体をもつ支持体。
［８］ ［６］記載のパターン形成方法により形成されたメタルパターンを有する支持体。 Accordingly, the present invention provides a support having a resin structure having the following pattern forming method and undercut shape.
[1] (1) The process of apply | coating the photosensitive resin composition containing the following (A)-(D) component to a support body,
(A) an alkali-soluble novolak resin,
(B) a quinonediazide sulfonic acid ester photosensitizer,
(C) an aromatic hydroxy compound having a formula weight of 240 to 1,500,
(D) an organic solvent,
(2) A step of heating the support on which the composition is applied,
(3) A step of irradiating a desired portion of the obtained film of the composition with radiation having a wavelength of 300 to 600 nm,
(4) including a step of forming a pattern by development with an alkaline developer;
With regard to the development time in the step (4), the line width and space width obtained when a line-and-space pattern comprising a repetition of the line width and space width equal to the film thickness of the composition is 1: 1. A pattern forming method comprising performing development with a development time of 5 to 15 times the shortest development time, and forming a resin structure having an undercut shape at the bottom portion of the pattern shape obtained after development.
[2] (2) T ≦ 5H and H ≦ 0.7T, where T is the resist film thickness after the process, and (4) H is the cut height of the undercut shape after the process. The pattern formation method as described.
[3] The component (B) quinonediazide sulfonate photosensitizer is naphthoquinonediazide sulfonate of 2,3,4-trihydroxybenzophenone, naphthoquinonediazide sulfonate of 2,3,4,4′-tetrahydroxybenzophenone Ester, naphthoquinonediazide sulfonic acid ester of 2,2 ′, 4,4′-tetrahydroxybenzophenone, and a compound represented by the following general formula (1) or (2), trihydroxybenzophenone, and tetrahydroxybenzophenone The compound is selected from compounds in which one or a plurality of hydroxy group hydrogen atoms are substituted with a naphthoquinonediazidesulfonyl group, and the component (B) is added in an amount of 20 to 55 parts by mass with respect to 100 parts by mass of the alkali-soluble novolak resin (A). Blended [1] or Is the pattern forming method according to [2].

(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 and k + q ≦ 5. is there.)
[4] The aromatic hydroxy compound of component (C) is represented by the following formulas (1), (2), (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 and k + q ≦ 5. is there.)

[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 w is an integer of 1 to 3 in the following formula (6) in which a hydroxy group is added to the benzene ring, wherein x and y are 0 to 3 respectively. Is an integer.)

(Wherein v and w are each an integer of 0 to 3)]
Wherein the component (C) is blended in an amount of 2 to 70 parts by mass with respect to 100 parts by mass of the alkali-soluble novolak resin (A). Pattern forming method.
[5] The photosensitive resin composition further includes (E) an alkali-soluble cellulose resin, and the content thereof is 3 to 30 parts by mass with respect to 100 parts by mass of the alkali-soluble novolac resin (A). [4] The pattern forming method according to any one of [4].
[6] A metal layer is formed on the entire resist pattern made of a resin structure having an undercut shape formed by the pattern forming method according to any one of [1] to [5], and then the resist pattern and the pattern are formed on the resist pattern. A pattern forming method comprising forming a metal pattern on a substrate by peeling off a formed metal layer.
[7] A support having a resin structure having an undercut shape formed by the pattern forming method according to any one of [1] to [5].
[8] A support having a metal pattern formed by the pattern forming method according to [6].

  The present invention uses a photosensitive resin composition (lift-off resist composition) containing the above-mentioned components (A) to (D), and has a lift-off shape (undercut shape) having a large cut height compared to conventional processes. A support having a resin structure characterized by the above can be obtained.

It is sectional drawing of the resist which has an undercut shape.

Hereinafter, the present invention will be described in more detail.
The photosensitive resin composition that can be used in the present invention is a positive lift-off resist composition, and is not particularly limited as long as it is a generally known positive lift-off resist composition for a single layer. If it is the positive lift-off resist composition for single layers shown, the effect of the present invention can be effectively obtained.

  That is, the positive lift-off resist composition for single layer used as the photosensitive resin composition in the present invention includes (A) an alkali-soluble novolak resin, (B) a quinonediazide sulfonate ester photosensitizer, and (C) a formula weight of 240 to 1 , 500 aromatic hydroxy compound and (D) an organic solvent as essential components.

  (A) About alkali-soluble novolak resin, the condensation reaction product of phenols and aldehydes can be used. 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 product thus obtained, a product obtained by cutting a low molecular weight region by performing a treatment such as fractionation can be used.

  In the present invention, a novolak resin obtained by condensation of several mixed phenols selected from m-cresol, p-cresol, o-cresol, 2,5-xylenol and 3,5-xylenol phenols with formaldehyde Among them, the weight average molecular weight in terms of polystyrene by gel permeation chromatography (GPC) method (solvent tetrahydrofuran) is preferably 2,000 to 20,000, more preferably 2,500 to 15,000. It is a novolac resin.

  (B) 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, 2,2 ′, 4,4′-tetrahydroxybenzophenone naphthoquinonediazide sulfonic acid ester and the like, but not limited to those produced industrially, compounds represented by the following general formula (1) or (2), trihydroxy Among the compounds selected from benzophenone and tetrahydroxybenzophenone, a photosensitizer in which one or a plurality of hydroxy group hydrogen atoms are substituted with a naphthoquinonediazidesulfonyl group can be 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 and k + q ≦ 5. is there.)

  Of these, 65 mol% or more of the phenolic hydroxy group is preferably esterified with naphthoquinone diazide sulfonic acid in terms of lift-off pattern formation. In the present invention, a part of the hydroxy group that is not substituted with a naphthoquinonediazidesulfonyl group may be acylated. In that case, acylation can be carried out by a conventional method.

  In the present invention, the blending amount of the photosensitive agent component with respect to 100 parts by mass of (A) alkali-soluble novolak resin is preferably 20 to 55 parts by mass, more preferably 25 to 50 parts by mass, and most preferably 30 to 45 parts by mass. . These photosensitizers may be used alone or in combination of two or more.

  (C) The aromatic hydroxy compound having a formula weight of 240 to 1,500 has preferably 2 to 15, more preferably 3 to 10, particularly preferably 3 to 7, benzene rings, 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, and most preferably 0.6 to 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 formula weight exceeding 1,500 is not suitable because the effect of the present invention is lowered. Specifically, when an aromatic hydroxy compound having a formula weight exceeding 1,500 is blended, the target undercut becomes small, and it is difficult to obtain the effects of the present invention. 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.

（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である。） In this case, as the aromatic hydroxy compound as the component (C), compounds represented by the following formulas (1) and (2) and further the formula (5) are preferably used.

(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 and k + q ≦ 5. is there.)

［（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式（６）の構造を有する。式中、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。）］

[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 the structure of formula (6) in which a hydroxy group is added to the benzene ring, wherein x and y are each an integer of 0 to 3.)

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

In the present invention, the (C) aromatic hydroxy compound may be used alone or in combination of two or more.
The blending amount is preferably 2 to 70 parts by mass, more preferably 5 to 60 parts by mass, and particularly preferably 10 to 50 parts by mass with respect to 100 parts by mass of the (A) alkali-soluble novolak resin.

  In addition, polyhydroxystyrene, alkali-soluble resins such as alkali-soluble cellulose resin, azo compounds such as 2-benzeneazo-4-methylphenol and 4-hydroxy-4′-dimethylaminoazobenzene, Various compounding agents such as a dye such as curcumin and a pigment can be added. Among these, alkali-soluble cellulose resins are particularly preferable because the effects of the present invention can be effectively obtained.

［式中、Ｒ¹は独立に、酸価３０〜１５０ＫＯＨｍｇ／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樹脂が好ましい。 This alkali-soluble cellulose resin is the following structural formula (3)

[In the formula, R ¹ independently represents 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 KOHmg / 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. ]
An alkali-soluble cellulose resin represented by

  This alkali-soluble cellulose resin does not dissociate when the introduced carboxyalkyl group is acidic, and itself is hydrophobic and acid-resistant, but dissociates in a weakly acidic to neutral region, so it dissolves in an aqueous or alkaline solution. In addition, it becomes a resin binder that is 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.

  When the acid value is less than 30 in the formula (3), the effect of improving the sensitivity and promoting the undercut is small.

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, an acyl group having 2 to 8 carbon atoms, or an acid group within a range showing an acid value of 30 to 150 KOH mg / g. The ratio of the organic group represented by the structural formula (4) and the organic group represented by the above formula (4) in R ¹ is an average of 2 to 30 mol% per unit glucose ring.

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 ter-butyl group or the like, an alkyl group having 1 to 4 carbon atoms, a hydroxymethyl group, a hydroxyethyl group. Groups, C1-C4 hydroxyalkyl groups such as 2-hydroxypropyl group, C2-C8 acyl groups such as acetyl group, propionyl group and butyryl group. Moreover, as R 'in Formula (4), C2-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 compounding amount of the (E) alkali-soluble cellulose resin represented by the formula (3) is 0 to 30 parts by mass, preferably 3 to 30 parts by mass with respect to 100 parts by mass of the alkali-soluble novolak resin as the component (A). In particular, it is preferable to blend 7 to 20 parts by mass. On the other hand, if the amount exceeds 30 parts by mass, the solubility of the composition in the aqueous alkaline solution increases, the remaining film property is inferior, the undercut becomes too large, and pattern formation may be 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. Among them, nonionic ones are preferable, for example, Fluorad FC-430 (manufactured by Sumitomo 3M), X-70. -092, X-70-093 (all manufactured by Shin-Etsu Chemical Co., Ltd.) and the like.

  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, 100-9,800 mass parts is suitable with respect to 100 mass parts of alkali-soluble novolak resin (A) normally.

A support having a resin structure characterized by a lift-off shape using the positive lift-off resist composition for a single layer of the present invention,
(1) A step of applying a positive lift-off resist composition for a single layer to a support,
(2) a step of heating the support coated with the photosensitive resin composition;
(3) A step of irradiating the composition film with radiation having a wavelength of 300 to 600 nm,
(4) including a step of forming a pattern by development with an alkaline developer, and using a line-and-space pattern comprising a repetition of a line width and a space width equal to the thickness of the composition film for the development time of the step (4) The bottom portion of the pattern shape obtained after development has an undercut shape by performing development with a development time of 5 to 15 times the shortest development time in which the line width and space width obtained are 1: 1. It can be obtained by forming a resin structure.

As a manufacturing method of the support for forming the resin structure, (1) in the step of applying the positive lift-off resist composition for single layer to the support, Si, SiO ₂ , SiN, SiON, TiN, WSi, BPSG, SOG In addition to a support (substrate) such as Au, Ti, W, Cu, Ni-Fe, Ta, Zn, Co, Pb, etc., a spin coat or roll coat on a support such as an organic antireflection film This is a step of applying a desired film thickness by an appropriate application method such as flow coating, dip coating, spray coating, doctor blade coating or the like.

  Next, (2) by applying the photosensitive resin composition described above to form a film on a support, and heating the support, the process is performed on a hot plate or in an oven at 60 to 150 ° C. for 1 to 60 minutes. Preferably, prebaking is performed at 80 to 120 ° C. for 1 to 10 minutes to obtain a film thickness of 0.5 to 20 μm, preferably 0.6 to 10 μm.

(3) In the step of irradiating the composition film with radiation having a wavelength of 300 to 600 nm, the target pattern is exposed through a predetermined mask using a light source selected from ultraviolet rays, electron beams, and the like. is there. Exposure at that time, 1~1,500mJ / cm ^2, preferably about, it is preferable that the exposure so that 10~1,000mJ / cm ² approximately.

  Thereafter, post-exposure baking (PEB) may be performed on a hot plate or in an oven at 60 to 150 ° C. for 1 to 30 minutes, preferably 80 to 120 ° C. for 1 to 10 minutes, if necessary.

  Finally, (4) in the step of forming a pattern by development with an alkaline developer, a developer of an aqueous alkali solution such as 0.1 to 5% by mass, preferably 2-3% by mass of tetramethylammonium hydroxide (TMAH). And developing for 0.1 to 60 minutes, preferably 0.5 to 10 minutes, by a conventional method such as a dip method, a paddle method, or a spray method. It is the effect of the present invention by performing development at a development time of 5 to 15 times, preferably 6 to 10 times the development time when the ratio (ratio of line width to space width) is 1: 1. A support having a resin structure characterized by a lift-off pattern shape having a large cut height can be obtained. The aspect ratio is expressed as a ratio between the line width and the space width, and it is further desirable that the line width = space width = resist film thickness. When the development time is less than 5 times the shortest development time when the aspect ratio is 1: 1, the cut height becomes low. On the other hand, a development time exceeding 15 times is not preferable because it depends on the pattern size, but the horizontal cut length becomes too long and the pattern collapses. The undercut shape is not particularly defined, but when the resist film thickness is T and the undercut shape cut height after the alkali development step is H in the thickness direction, T ≦ 5H, H ≦ It is desirable to form the structure so as to be 0.7T.

  Regarding the development time, the support is taken out from the developer every 30 seconds, rinsed with pure water, and then there is no residual film in the exposed portion of the dried support surface, and the thickness of the composition film The shortest development time was defined as the shortest development time among the development times in which the line width and the space width were 1: 1 when a line and space pattern consisting of repetition of equal line width and space width was used.

  Thereafter, a metal film (Cu, Al, Cr, Fe, Au, Ag, Ta, Ru, Rh, Pt, Pd, Ir, etc.) and a dielectric film (poly-Si, silicon nitride) containing Si are formed on the obtained support. Film, silicon oxynitride film, etc.) is formed by sputtering, plasma CVD, etc. to a thickness of 0.1 to 10 μm, and then the resist pattern and the film on the pattern are peeled together to form a desired surface on the support. A film formation pattern may be formed.

  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 kept 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), flow volume 1.5mL / min, elution solvent THF. The column temperature was 40 ° C.

[Compositions 1 to 3]
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) (I), aromatic hydroxy compound (molecular weight 292) (II) represented by the following formula (7), alkali-soluble cellulose A (manufactured by Shin-Etsu Chemical Co., Ltd., hydroxypropyl methylcellulose phthalate: acid value) 92 KOH mg / g, containing 20 mol% of carboxybenzoyl group) (III) was mixed at the compounding ratio shown in Table 1, and X-70-093 (organosiloxane polymer manufactured by Shin-Etsu Chemical Co., Ltd.) was used as a surfactant to improve coating properties. 0.1 parts by mass), and the mixing ratio of ethyl lactate and butyl acetate is 85 parts by mass and 15 parts by mass. After the solvent in homogeneous solution is, filtered through a 0.2μm membrane filter, to prepare a positive lift-off resist solution shown in Table 1.

The obtained resist solution was applied onto a Si substrate and soft-baked on a hot plate at 100 ° C. for 120 seconds. The composition 1 was 1.5 μm, the composition 2 was 3 μm, and the composition 3 was 5 μm. A resist film was formed as a support. Next, exposure with an i-line stepper through a reticle (Nikon, NA = 0.5), heating at 120 ° C. for 90 seconds, development with an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution, It was rinsed with water for 30 seconds and dried. The development time at this time is shown in Table 2.
The shortest development time is 1 line width and space width obtained when the support is taken out from the developer every 30 seconds and a line and space pattern consisting of repeated line width and space width equal to the film thickness is used. The development time was defined as the time at which the ratio becomes 1. The aspect ratio = resist film thickness / line width = 1.

About the optimal exposure amount (Eop), it was set as the exposure amount when the repetition of a 1.5 micrometers, 3 micrometers, and 5 micrometers line and space becomes equal in order about composition 1,2,3. The pattern shape was confirmed with a repeated pattern of 10 μm lines and spaces at the optimum exposure dose, and the pattern shape as shown in FIG. 1 was confirmed. Regarding the pattern shape, the cross-sectional shape was observed with an electron microscope (manufactured by Hitachi), and the horizontal cut amount (one side) C and the maximum cut height amount H from the substrate shown in FIG. 1 were measured. The results are shown in Table 2. In FIG. 1, A: line width, B: ground contact width with substrate, C: notch width, H: notch height (A = B + 2C). Moreover, as a result of comprehensively judging both the amount of cut in the horizontal direction and the amount of cut in the height direction, a good undercut shape was judged as ◯, and a poor undercut shape was judged as x.
The results are shown in Table 2.

  In any of the examples, a pattern having an undercut shape at the bottom portion having a high degree of cut was able to be formed.

  Therefore, according to the present invention, it is possible to obtain a lift-off resist pattern having a large notch height while using an existing positive lift-off resist composition.

  Furthermore, a Ti target was mounted on a sputtering apparatus (manufactured by Canon Anelva Co., Ltd.) on the support having been subjected to the same process as in Example 1 again using composition 1, and was subjected to a film formation process at 500 W for 15 minutes. Went. When the cross section of the obtained substrate was observed using an electron microscope, it was confirmed that a 0.25 μm Ti film was laminated. This substrate was immersed in N-methyl-2-pyrrolidone at 60 ° C. for 20 minutes, rinsed with pure water, and the dried substrate was confirmed with an electron microscope. Was obtained.

Claims (8)

(1) The process of apply | coating the photosensitive resin composition containing the following (A)-(D) component to a support body,
(A) an alkali-soluble novolak resin,
(B) a quinonediazide sulfonic acid ester photosensitizer,
(C) an aromatic hydroxy compound having a formula weight of 240 to 1,500,
(D) an organic solvent,
(2) A step of heating the support on which the composition is applied,
(3) A step of irradiating a desired portion of the obtained film of the composition with radiation having a wavelength of 300 to 600 nm,
(4) including a step of forming a pattern by development with an alkaline developer;
With regard to the development time in the step (4), the line width and space width obtained when a line-and-space pattern comprising a repetition of the line width and space width equal to the film thickness of the composition is 1: 1. A pattern forming method comprising performing development with a development time of 5 to 15 times the shortest development time, and forming a resin structure having an undercut shape at the bottom portion of the pattern shape obtained after development.   (2) The pattern according to claim 1, wherein T ≦ 5H and H ≦ 0.7T, where T is the resist film thickness after the process, and (4) H is the cut height of the undercut shape after the process. Forming method. The component (B) quinonediazide sulfonate photosensitizer is a naphthoquinone diazide sulfonate ester of 2,3,4-trihydroxybenzophenone, a naphthoquinone diazide sulfonate ester of 2,3,4,4′-tetrahydroxybenzophenone, 2 , 2 ′, 4,4′-tetrahydroxybenzophenone naphthoquinonediazide sulfonic acid ester, and compounds selected from the following general formula (1) or (2), trihydroxybenzophenone, and tetrahydroxybenzophenone Claims selected from compounds in which hydrogen atoms of one or more hydroxy groups are substituted with naphthoquinonediazidesulfonyl groups, and the component (B) is blended in an amount of 20 to 55 parts by mass with respect to 100 parts by mass of the alkali-soluble novolak resin (A) Item 1 or 2 The pattern formation method of mounting.

(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 and k + q ≦ 5. is there.) The aromatic hydroxy compound of component (C) is represented by the following formulas (1), (2), (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 and k + q ≦ 5. is there.)

[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 w is an integer of 1 to 3 in the following formula (6) in which a hydroxy group is added to the benzene ring, wherein x and y are 0 to 3 respectively. Is an integer.)

(Wherein v and w are each an integer of 0 to 3)]
The pattern according to any one of claims 1 to 3, wherein 2 to 70 parts by mass of the component (C) is blended with respect to 100 parts by mass of the alkali-soluble novolak resin (A). Forming method.   The photosensitive resin composition further comprises (E) an alkali-soluble cellulose resin, and the content thereof is 3 to 30 parts by mass with respect to 100 parts by mass of the alkali-soluble novolak resin (A). The pattern forming method according to claim 1.   A metal layer is formed on the entire resist pattern made of a resin structure having an undercut shape formed by the pattern forming method according to claim 1, and then the resist pattern and the metal formed on the pattern A pattern forming method comprising forming a metal pattern on a substrate by peeling off a layer.   The support body which has the resin structure which has the undercut shape formed by the pattern formation method of any one of Claims 1-5.   A support having a metal pattern formed by the pattern forming method according to claim 6.