JP2008242247A - Two-layer laminate film and method for forming pattern using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a two-layer resist film for obtaining a resist pattern in which the undercut profile can be controlled to prevent formation of a continued undercut portion under a space between patterns, through one exposure and development, and thereby, easily forming a film layer with no fin even in a fine pattern having a line/space width of 10 μm/10 μm or less on a substrate surface, relating to a method for forming a vapor deposition and/or sputtering film by a lift-off process, and to provide a method for forming a pattern by using the two-layer resist film. <P>SOLUTION: A two-layer laminate film is formed by applying a specified resin composition 1 and a specified positive radiation-sensitive resin composition 2 on a substrate surface. The resist comprising the two-layer laminate film is exposed once to form a fine pattern having an undercut profile in the cross section. Then the pattern is used as a mask material to vapor deposit and/or sputter an organic or inorganic thin film and subjected to a lift-off process to form a pattern of a desired profile. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to so-called photofabrication that uses a photolithography technique in precision microfabrication. More specifically, the present invention is obtained from a positive-type radiation-sensitive resin composition suitable for lift-off methods used in the field of photofabrication such as semiconductors, electronic parts, display panels, touch panel and other wiring formation, electrode formation and the like. The present invention relates to a two-layer laminated film and a pattern forming method including a step of forming the two-layer laminated film.

  After applying a resist to the surface of the workpiece and patterning the resist film by photolithography, an organic or inorganic substance is deposited by vapor deposition and / or sputtering, and the organic thin film or inorganic thin film deposited on the resist film is deposited on the resist film. A method of obtaining a desired organic thin film pattern or inorganic thin film pattern in the resist opening by peeling off the whole is generally called a lift-off method.

  In this lift-off method, the shape of the resist pattern is very important. For example, when the resist pattern has a forward taper shape often found in a positive resist as shown in FIG. 3C, the thin film pattern obtained after the resist is peeled is as shown in FIG. The edge portion will have burrs.

  In order to prevent the formation of such burrs, as shown in FIG. 4C, a negative resist pattern that can form a so-called reverse taper-shaped resist pattern in which the bottom of the resist film removed by development is larger than the top of the opening. It is conceivable to use a mold resist or an image reversal resist.

  However, in these methods, it is generally difficult to control the shape of the resist pattern, and it is difficult to confirm the formed resist pattern with an optical microscope. Furthermore, since it is a curable type, it is difficult to remove the resist. There was a problem.

  In addition, since the surface of the workpiece to be the substrate generally undergoes a plurality of processing steps, it often has large irregularities with respect to the coating thickness of the resist, so that a resist film having a uniform thickness is formed. There was a problem that was difficult.

Further, from the viewpoint of improving the productivity of a workpiece, a technique that can easily form a pattern on the surface of the workpiece as a part of a series of steps without hindering the flow of the machining process has been desired. In order to address this problem, a method of forming an undercut resist pattern by a single exposure and development by a pattern forming method using a two-layer laminated film, thereby forming a film-forming layer without burrs (Patent Document 1) has been studied.

  However, in contrast to the fine processing required for miniaturization and thinning of semiconductors, electronic components, and display panels, in the photolithography using the lift-off method, an excessive undercut is caused at the lower part between patterns due to pattern miniaturization. Since they are connected, there may be a problem that the resist floats. In particular, in a fine pattern such as a line / space of 10 μm / 10 μm, it is difficult to control the undercut shape with the above-described prior art, and there is room for improvement. For this reason, control of the undercut shape in forming a fine pattern has been demanded.

As a result of intensive studies in view of such circumstances, the present inventors have found that a lower layer (resist layer [I]) obtained by using a specific resin composition 1 and a specific positive radiation-sensitive resin composition 2 The undercut shape can be controlled even in a fine pattern with a line / space of 10 μm / 10 μm or less by a pattern forming method comprising a step of forming a two-layer laminated film comprising an upper layer (resist layer [II]) obtained using It has been found that a resist pattern that can be obtained can be obtained by one exposure and development, whereby a film-forming layer having no burr can be easily formed, and the present invention has been completed.
JP 2003-287905 A

An object of this invention is to provide the resist film which can form easily the film-forming layer without a burr | flash on the substrate surface, and the pattern formation method using the same.
In particular, the present invention provides a resist pattern capable of controlling the undercut shape so that the undercut is not connected at the lower part between the patterns even in a fine pattern having a line / space of 10 μm / 10 μm or less. An object of the present invention is to provide a resist film that can be easily formed by exposure and development to form a film-forming layer without burrs, and a pattern forming method that forms a fine pattern using the resist film.

  The present invention provides a lower layer (resist layer [I]) obtained from a specific resin composition 1 and an upper layer (resist layer [I] that is obtained from a specific positive radiation-sensitive composition 2 formed on the lower layer. II]), and a method of forming a pattern by a lift-off method using the two-layer laminated film.

The two-layer laminated film according to the present invention comprises (A) a lower layer (resist layer) obtained from the resin composition 1 containing a polymer having a structural unit represented by the following general formula (1) and (C) a solvent. [I])
(D) A polymer having a phenolic hydroxyl group, (E) an upper layer (resist layer [II]) obtained from a positive radiation sensitive resin composition 2 containing a quinonediazide group-containing compound and (G) a solvent. It is characterized by.

(Wherein R ¹ is a hydrogen atom or a methyl group, R ² is a single bond, a methylene group, or an alkylene group having 2 to ³ carbon atoms, R ³ is an alkyl group having 1 to 4 carbon atoms, m Is an integer from 0 to 3.)
Moreover, the pattern formation method which concerns on this invention is a lower layer (resist layer) obtained from the resin composition 1 containing (A) the polymer containing the structural unit represented by the said General formula (1), and (C) solvent. [I])
2 comprising an upper layer (resist layer [II]) obtained from a positive radiation-sensitive resin composition 2 containing (D) a polymer having a phenolic hydroxyl group, (E) a quinonediazide group-containing compound and (G) a solvent. It is characterized by comprising a step of forming a layer laminated film.

The pattern forming method according to the present invention includes:
(A) After forming a lower layer on the substrate surface using the resin composition 1, an upper layer (resist layer) is formed on the lower layer (resist layer [I]) using the positive radiation sensitive resin composition 2. [II]) to form a two-layer laminated film;
(B) pattern exposure of the two-layer laminated film by exposure with UV light and / or drawing with an electron beam;
(C) A step of developing the two-layer laminated film that has undergone the step (b) to form a resist pattern having an undercut shape in which the bottom of the opening of the two-layer laminated film removed by the development is larger than the opening. When,
(D) a step of depositing and / or sputtering an organic thin film or an inorganic thin film on the surface of the two-layer laminated film that has undergone the resist pattern formation step (c) and the substrate surface at a position corresponding to the opening;
(E) It is preferable to include a step of peeling the vapor deposition film and / or the sputtered film deposited on the two-layer laminated film together with the two-layer laminated film.

The resin composition 1 preferably contains (B) a quinonediazide group-containing compound in addition to (A) a radical polymer having a structural unit represented by the general formula (1) and (C) a solvent (hereinafter referred to as “a”). (B) The resin composition 1 containing a quinonediazide group-containing compound may be referred to as a positive radiation sensitive resin composition 1).
The positive radiation sensitive resin composition 2 is (D) a polymer having a phenolic hydroxyl group,
A positive radiation-sensitive resin composition comprising (E) a quinonediazide group-containing compound, (F) a polyether resin, and (G) a solvent is preferable.
In the positive radiation sensitive resin composition 2, the polyether resin (F) is preferably polyethylene glycol or polyethylene glycol having a terminal alkoxy modification.

In the said resin composition 1, it is preferable that a polymer (A) is insoluble in water, is soluble in alkaline aqueous solution, and is insoluble or hardly soluble in the said solvent (G).
In the positive radiation sensitive resin composition 2, the solvent (G) contains at least one selected from the group consisting of 2-heptanone, 3-heptanone, 4-heptanone and cyclohexanone and / or dialkylene glycol dialkyl ether. A solvent is preferred.

The film thickness of the lower layer (resist layer [I]) is in the range of 0.1 μm to 3.0 μm, and the film thickness of the upper layer (resist layer [II]) is in the range of 0.1 μm to 10 μm. Is preferred.
In the present invention, the substrate used in the step (a) is not particularly limited as long as the two-layer laminated film of the present invention can be formed, but a Si wafer, a glass substrate, a ceramic substrate, a printed wiring board, a film, etc. A substrate obtained by processing these is preferably used.

Moreover, as an organic thin film or an inorganic thin film of the said process (d), DLC (Diamond L)
ike Carbon) film, SiO ₂ , SiN, Au, Pd, Ag, Pt, Cu, Cr,
Al, Ta, Ni, Cr, TiN, TiC, ITO, etc. TiO ₂ and the like. Applications of these thin films include optical applications such as wiring, electrodes, resistors, insulating films, dielectrics, and reflective films, and protective films.

  According to the present invention, a fine resist pattern having an undercut shape in cross section can be formed on a substrate by a single exposure and development, and a desired thin film (on the substrate) by a lift-off method using this resist pattern. Organic or inorganic thin film) patterns can be formed.

  Especially this invention is a pattern provided with the process of forming the two-layer laminated film which consists of the lower layer formed using the specific resin composition 1, and the upper layer formed using the specific positive type radiation sensitive resin composition 2 Depending on the formation method, a resist pattern capable of controlling the undercut shape even in a fine pattern having a line / space of 10 μm / 10 μm or less can be obtained.

A resist pattern that can control the appropriate undercut shape without connecting the undercut at the bottom of the pattern even in a fine pattern where the line / space is 10 μm / 10 μm or less is dense. Since there are many advantages in the manufacturing process, such as easily forming a film-forming layer without burrs, being able to confirm the shape with an optical microscope, and being easy to peel off, the present invention is incorporated in the manufacturing process. By using it, productivity of a workpiece can be improved.

  In addition, the resist pattern according to the present invention is a wiring that requires fine processing as semiconductors, electronic components, and display panels become smaller and thinner because the thin film deposited or sputtered in the step (d) has conductivity. Or it can use suitably also for the use which forms an electrode.

Hereinafter, the present invention will be specifically described.
The two-layer laminated film according to the present invention comprises (A) a lower layer (resist layer [I] obtained from a resin composition 1 containing a polymer having a structural unit represented by the following general formula (1) and (C) a solvent. ])When,
(D) A polymer having a phenolic hydroxyl group, (E) an upper layer (resist layer [II]) obtained from a positive radiation sensitive resin composition 2 containing a quinonediazide group-containing compound and (G) a solvent. It is characterized by.

(Wherein R ¹ is a hydrogen atom or a methyl group, R ² is a single bond, a methylene group, or an alkylene group having 2 to ³ carbon atoms, R ³ is an alkyl group having 1 to 4 carbon atoms, m Is an integer from 0 to 3.)
First, the resin composition 1 and the positive radiation sensitive resin composition 2 used in the present invention will be specifically described.

<Lower resin composition 1 (Composition 1)>
The resin composition 1 (hereinafter also simply referred to as the composition 1) used in the present invention contains (A) a polymer having a structural unit represented by the general formula (1) and (C) a solvent.

((A) Polymer having structural unit represented by general formula (1))
In the present invention, (A) the structural unit of the polymer having the structural unit represented by the general formula (1) (hereinafter also simply referred to as “polymer (A)”) is derived from the monomer I shown below. .

The monomer I is a radically polymerizable compound represented by the general formula (2).
(Monomer I)

(Wherein R ¹ is a hydrogen atom or a methyl group, R ² is a single bond, a methylene group, or an alkylene group having 2 to ³ carbon atoms, R ³ is an alkyl group having 1 to 4 carbon atoms, m Is an integer from 0 to 3.)
Examples of the alkylene group having 2 or 3 carbon atoms in R ² include an ethylene group, a propylene group, and an isopropylene group. R ² is preferably a methylene group. The alkyl group having 1 to 4 carbon atoms in R ³ is a methyl group, an ethyl group, a propyl group,
Examples thereof include an isopropyl group, an n-butyl group, a sec-butyl group, and a tert-butyl group, and the R ³ is preferably a methyl group. Specific examples of the monomer I of the radical polymerizable compound that is the structural unit of the resin composition 1 represented by the general formula (2) include 3,5-dimethyl-4-hydroxybenzylacrylamide.

  The polymer having a structural unit derived from the monomer I is essential for imparting a suitable alkali solubility and polarity to the composition 1 and imparting a polarity that allows slight intermixing with the upper layer film. . That is, when the lower layer containing the composition 1 as a component forms an upper layer and a two-layer laminated film in accordance with the processing steps (a), (b), and (c), and then exposure and development, an alkaline developer In practical use, it exhibits moderate alkali solubility, can control the desired undercut shape within the desired development time range, and does not substantially dissolve in the rinse step with deionized water after development. It becomes important. The appropriate polarity is also important in the affinity to the alkali developer and the adhesion to the substrate, but the most important thing is that the lower layer and the upper layer are formed when the composition 2 constituting the upper layer is formed on the lower layer. Is to suppress intermixing. That is, intermixing is suppressed by setting the polarity of the composition 1 constituting the lower layer high and providing a difference in polarity between the components of the composition 2 constituting the upper layer.

  When the intermixing proceeds excessively, the upper and lower layer compositions are mixed non-uniformly, making it difficult to control the undercut shape as designed, and developing residue occurs at the substrate interface.

On the other hand, if intermixing does not proceed at all between the upper layer and the lower layer, an interface is formed between the upper layer and the lower layer, and when developed, the upper layer peels off at the interface, or development proceeds significantly only at the interface, and the underlayer It becomes difficult to control the cut shape.

Furthermore, the polymer (A) may contain a polymer having a structural unit derived from the monomer II as another radical polymerizable compound described below.
(Monomer II)
The polymer having a structural unit derived from the monomer II is contained in the polymer (A) mainly for the purpose of appropriately controlling the mechanical properties of the polymer and for the purpose of controlling the glass transition temperature of the polymer. Can do.

  The monomer II is a monomer other than the monomer I and does not contain a carboxyl group. Specifically, (meth) acrylic acid alkyl esters, (meth) acrylic acid aryl esters, dicarboxylic acid diesters, aromatic vinyls, conjugated diolefins, nitrile group-containing polymerizable compounds, chlorine-containing polymerizable compounds Amide bond-containing polymerizable compounds, fatty acid vinyls and the like.

Examples of the (meth) acrylic acid alkyl ester include methyl methacrylate, ethyl methacrylate, n-butyl (meth) acrylate, sec-butyl (meth) acrylate, t-butyl (meth) acrylate, isopropyl (meth) acrylate and the like;
Examples of the (meth) acrylic acid aryl ester include phenyl (meth) acrylate and benzyl (meth) acrylate;
Examples of the dicarboxylic acid diester include diethyl maleate, diethyl fumarate, diethyl itaconate and the like;
Examples of the aromatic vinyls include styrene, α-methylstyrene, m-methylstyrene, p-methylstyrene, vinyltoluene, and p-methoxystyrene;
Examples of the conjugated diolefins include 1,3-butadiene, isoprene, 1,4-dimethylbutadiene and the like;
Examples of the chlorine-containing polymerizable compound include nitrile group-containing polymerizable compounds such as acrylonitrile and methacrylonitrile; vinyl chloride and vinylidene chloride;
Examples of the amide bond-containing polymerizable compound include acrylamide and methacrylamide;
Vinyl acetate and the like as the fatty acid vinyls;
Etc. These compounds can be used alone or in combination of two or more. Of these, acrylic acid alkyl esters, particularly n-butyl acrylate, are preferred.

  Thus, the polymer (A) used in the present invention is a (co) polymer obtained by radical polymerization of the essential monomer I and, if necessary, the monomer II. Polymerization can be carried out, for example, by the method described in JP-A-2003-73424. Among these (co) polymers, a copolymer obtained by radical polymerization of the monomer I and the monomer II is preferable.

When the polymer (A) is a copolymer obtained by radical polymerization of the monomer I and the monomer II, the constituent unit content of each monomer is
The monomer I unit content is usually 70 to 99% by weight, preferably 80 to 99% by weight,
Monomer II unit content is 1-30 weight% normally, Preferably it is 1-20 weight%.

  If the monomer II unit content exceeds 30% by weight, it tends to be difficult to control the undercut shape, and if the monomer II unit content exceeds 20% by weight, an appropriate undercut margin cannot be secured. there is a possibility.

The monomer unit content refers to the content ratio of the monomer unit contained when the polymer (A) is 100, which means a weight ratio.
Examples of the polymer (A) include PPH-1000, PPH-7100, PPH-7200, PPH-7400, PPH-7800, PPH-7900 (manufactured by Showa Polymer Co., Ltd.).

  As a polymerization solvent used when synthesizing the polymer (A), alcohols, cyclic ethers, alkyl ethers of polyhydric alcohols, alkyl ether acetates of polyhydric alcohols, aromatic hydrocarbons, ketones, Examples include esters.

Specifically, as the alcohols, methanol, ethanol, ethylene glycol, diethylene glycol, propylene glycol and the like;
Examples of the cyclic ethers include tetrahydrofuran, dioxane and the like;
Examples of the alkyl ethers of the polyhydric alcohol include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether. , Propylene glycol monomethyl ether, propylene glycol monoethyl ether, etc .;
Examples of the alkyl ether acetates of the polyhydric alcohol include ethylene glycol ethyl ether acetate, diethylene glycol ethyl ether acetate, and propylene glycol ethyl ether acetate;
Examples of the aromatic hydrocarbons include toluene and xylene;
Examples of the ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone, diacetone alcohol, and the like;
Examples of the esters include ethyl acetate, butyl acetate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, 2- Methyl hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, ethyl acetate, butyl acetate and the like;
Is mentioned.

Of these, cyclic ethers, polyhydric alcohol alkyl ethers, polyhydric alcohol alkyl ether acetates, ketones, and esters are preferred.
Moreover, as a polymerization catalyst in radical polymerization, a normal radical polymerization initiator can be used, for example, 2,2'-azobisisobutyronitrile, 2,2'-azobis- (2,4-dimethylvaleronitrile). Azo compounds such as 2,2'-azobis- (4-methoxy-2,4-dimethylvaleronitrile); benzoyl peroxide, lauroyl peroxide, t-butylperoxypivalate, 1,1'-bis- (t-butyl And organic peroxides such as peroxy) cyclohexane and hydrogen peroxide. In addition, when using a peroxide for a radical polymerization initiator, it is good also as a redox type initiator combining a reducing agent.

The molecular weight of the polymer (A) is a weight average molecular weight (weight average molecular weight in the present specification) from the viewpoint of developability and adhesion in the lower layer (resist layer [I]) formed using the resin composition 1. Are all in terms of polystyrene according to the GPC method) is preferably 4000 to 25000, more preferably more than 10,000 and less than 22,000. When the weight average molecular weight is less than 4000, the development time of the two-layer laminated film is too short. On the other hand, when it exceeds 25000, the development time is too long and the resolution tends to decrease. The weight average molecular weight is preferably more than 10,000 from the viewpoint of securing an appropriate undercut margin, and is preferably less than 22,000 from the viewpoint of undercut shape control.

  The polymer (A) is preferably insoluble in water and soluble in an alkaline aqueous solution from the viewpoint of developability and the formation of a desirable undercut resist pattern. In addition, when the upper layer (resist layer [II]) is laminated on the lower layer (resist layer [I]), it is insoluble or hardly soluble in the solvent (G) described later from the viewpoint of preventing the generation of these mixed layers. It is preferable that

Here, insoluble in water means that the polymer (A) does not substantially dissolve in water. Specifically, the amount is 0.1 g or less with respect to 100 g of water at 25 ° C. It may be dissolved.
Further, being soluble in an alkaline aqueous solution means that it can be suitably developed with an alkali. Specifically, the alkaline aqueous solution, for example, 100 g of an aqueous 2.38 wt% tetramethylammonium hydroxide solution at 25 ° C. On the other hand, it means that 5 g or more of the polymer (A) is preferably dissolved. By using such a polymer (A), it is possible to impart moderate alkali solubility to the lower layer and polarity capable of slight intermixing with the upper layer, and fine wiring with a line / space = 10 μm / 10 μm or less. Also when forming the undercut shape, the undercut shape can be controlled to 2 to 3 μm. Here, the alkali constituting the alkaline aqueous solution is not particularly limited, but examples of the alkali constituting the developer include those described later.

  Furthermore, insoluble or hardly soluble in the solvent (G) means that the polymer (A) is not substantially dissolved in the solvent (G) described later, or is very small even if dissolved. Specifically, the polymer (A) may be dissolved in an amount of 0.1 g or less with respect to a solvent (G) described later, for example, 100 g of 2-heptanone at 25 ° C.

((C) solvent)
Specific examples of the solvent (C) used in the composition 1 include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, Propylene glycol monomethyl ether acetate, propylene glycol monopropyl ether acetate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, 3 -Methyl methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, vinegar It may be mentioned butyl, methyl pyruvate, ethyl pyruvate and the like. Further, N-methylformamide, N, N-dimethylformamide, N-methylformanilide, N-methylacetamide, N, N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, benzylethyl ether, dihexyl ether, acetonylacetone , Isophorone, caproic acid, caprylic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate, propylene carbonate, ethylene glycol monophenyl ether A high boiling point solvent such as acetate can also be used. These solvents can be used alone or in combination of two or more. Of these, ethyl 2-hydroxypropionate is preferred.

When these compositions are applied on a substrate by spin coating, the solid content concentration of the composition 1 is usually 1% by weight to 50% by weight. Preferably, it is used in the range of 5 to 25% by weight. That is, the solvent is usually used in an amount of 100 to 9900 parts by weight, preferably 300 to 1900 parts by weight, with respect to 100 parts by weight of the total of the polymer (A) and the quinonediazide group-containing compound (B).

((B) quinonediazide group-containing compound)
The resin composition 1 may contain a quinonediazide group-containing compound as a photosensitizer. (B) By adding a quinonediazide group-containing compound, the difference between the development time (t ₂ ) when the retraction amount W of the undercut portion of the two-layer resist film during development is 10 μm and the development time (t ₁ ) when it is 0 μm. (T ₂ -t ₁ ) can be secured to a length that does not cause a problem in an actual manufacturing process, for example, 30 seconds or more. Here, as shown in FIG. 2, the retraction amount W of the undercut portion is the lower layer in the region of the undercut shape where the opening bottom portion of the two-layer laminated film removal portion by development is larger than the opening portion. 2 is a region obtained by subtracting the narrowest region of the opening portion derived from the upper layer 3 from the most widely receded region.

Examples of the quinonediazide group-containing compound include polyhydroxybenzophenones, bis [(poly) hydroxyphenyl] alkanes, tris (hydroxyphenyl) methanes or methyl substitutes thereof, bis (cyclohexylhydroxyphenyl) hydroxyphenylmethanes or methyls thereof. Substituted or 4,4 ′-[1- [4- [1- (4-hydroxyphenyl) -1-methylethyl] phenyl] ethylidene] diphenol or 7-hydroxy-4- (4′-hydroxyphenyl) Copolymerization with 2-methyl-2- (2 ′, 4′-dihydroxy) phenylcoumarone, or a novolak resin, pyrogallol-acetone resin, p-hydroxystyrene homopolymer or a monomer copolymerizable therewith A compound having a hydroxyl group or amino group Things like; and,
And quinonediazide group-containing sulfonic acid or naphthoquinone-1,2-diazide-5-sulfonyl chloride; and the like; and complete ester compounds, partial ester compounds, amidated products, and partially amidated products.

Specifically, the polyhydroxybenzophenones include 2,3,4-trihydroxybenzophenone, 2,4,4′-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, 2,3,6-tri Hydroxybenzophenone, 2,3,4-trihydroxy-2′-methylbenzophenone, 2,3,4,4′-tetrahydroxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 2,3 ′, 4,4 ′, 6-pentahydroxybenzophenone, 2,2 ′, 3,4,4′-pentahydroxybenzophenone, 2,2 ′, 3,4,5-pentahydroxybenzophenone, 2,3 ′, 4,4 ',
5 ′, 6-hexahydroxybenzophenone, 2,3,3 ′, 4,4 ′, 5′-hexahydroxybenzophenone, etc .;
Examples of the bis [(poly) hydroxyphenyl] alkanes include bis (2,4-dihydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl) methane, 2- (4-hydroxyphenyl) -2- ( 4'-hydroxyphenyl) propane, 2- (2,4-
Dihydroxyphenyl) -2- (2 ′, 4′-dihydroxyphenyl) propane, 2- (2,3,4-trihydroxyphenyl) -2- (2 ′, 3 ′, 4′-trihydroxyphenyl) propane and the like ;
Examples of the tris (hydroxyphenyl) methanes or methyl substitution products thereof include tris (4-hydroxyphenyl) methane, bis (4-hydroxy-3,5-dimethylphenyl) -4-hydroxyphenylmethane, and bis (4-hydroxy-). 2,5-dimethylphenyl) -4-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -2- Hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3,4-dihydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3,4-dihydroxyphenylmethane and the like;
Examples of the bis (cyclohexylhydroxyphenyl) hydroxyphenylmethanes or methyl substitution products thereof include bis (3-cyclohexyl-4-hydroxyphenyl) -3-hydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxyphenyl) -2- Hydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxyphenyl) -4-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -2-hydroxyphenylmethane, bis (5-cyclohexyl- 4-hydroxy-2-methylphenyl) -3-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-2-methylphenyl) -4-hydroxyphenylmethane, bis (3-cyclohexyl-2-hydroxy) Phenyl) -3-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-3-methylphenyl) -4-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-3-methylphenyl) -3-hydroxy Phenylmethane, bis (5-cyclohexyl-4-hydroxy-3-methylphenyl) -2-hydroxyphenylmethane, bis (3-cyclohexyl-2-hydroxyphenyl) -4-hydroxyphenylmethane, bis (3-cyclohexyl-2) -Hydroxyphenyl) -2-hydroxyphenylmethane, bis (5-cyclohexyl-2-hydroxy-4-methylphenyl) -2-hydroxyphenylmethane, bis (5-cyclohexyl-2-hydroxy-4-methylphenyl) -4 -Hydroxyfe Rumetan and the like;
4,4 '-[1- [4- [1- (4-hydroxyphenyl) -1-methylethyl] phenyl] ethylidene] diphenol;
7-hydroxy-4- (4′-hydroxyphenyl) -2-methyl-2- (2 ′, 4′-dihydroxy) phenylcoumarone;
A novolak resin, pyrogallol-acetone resin, a homopolymer of p-hydroxystyrene or a copolymer with a monomer copolymerizable therewith;
Examples of the compound having a hydroxyl group or amino group include phenol, p-methoxyphenol, dimethylphenol, hydroquinone, naphthol, pyrocatechol, pyrogallol, pyrogallol monomethyl ether, pyrogallol-1,3-dimethyl ether, gallic acid, aniline, p-aminodiphenylamine 4,4′-diaminobenzophenone, etc .;
Examples of the quinonediazide group-containing sulfonic acid include naphthoquinone-1,2-diazide-5-sulfonic acid, naphthoquinone-1,2-diazide-4-sulfonic acid, orthoanthraquinonediazidesulfonic acid, and the like; or naphthoquinone-1,2-diazide-5 -A complete ester compound, a partial ester compound, an amidated product or a partially amidated product with a sulfonyl chloride and the like can be mentioned.

The lower layer positive-type radiation-sensitive resin composition 1 used in the present invention may contain the quinonediazide group-containing compound alone or may contain two or more kinds.
Among these, 4,4 ′-[1- [4- [1- (4-hydroxyphenyl) -1-
An esterification reaction product of 1.0 mol of methylethyl] phenyl] ethylidene] diphenol and 1.0 mol of naphthoquinone-1,2-diazide-5-sulfonyl chloride is preferred.

  When composition 1 contains (B) a quinonediazide group-containing compound, (B) the quinonediazide group-containing compound is usually 1 to 40 parts by weight, preferably 100 parts by weight of the polymer (A), preferably 5 to 30 parts by weight, more preferably 5 to 20 parts by weight. When this compounding quantity exceeds 40 weight part, the adhesiveness with respect to the board | substrate of resist film [I] obtained may fall.

((H) surfactant)
In the composition 1, a surfactant can also be blended for the purpose of improving coating properties, defoaming properties, leveling properties, etc., and suppressing sink marks of the coating film immediately after coating. Examples of the surfactant include BM-1000, BM-1100 (manufactured by BM Chemie), MegaFuck F142D, F172, F173, F183 (manufactured by Dainippon Ink and Chemicals), Florard FC-135, FC-170C, FC-430, FC-431 (manufactured by Sumitomo 3M), Surflon S-112, S-113, S-131, S-141, S-145 (Asahi Glass ( ), SH-28PA, -190, -193, SZ-6032, SF-8428 (manufactured by Toray Silicone), NBX-15 (manufactured by Neos), etc. Fluorine-based surfactant, KL-245, KL-270 (manufactured by Kyoeisha Chemical Co., Ltd.), SH28PA (manufactured by Toray Dow Corning), etc. Nonionic S-6, Nonion 0-4, Pronon 201, Pronon 204 (manufactured by NOF Corporation), Emulgen A-60, A-90, A-500 (manufactured by Kao Corporation), KL One type or two or more types of nonionic surfactants marketed under names such as -600 (manufactured by Kyoeisha Chemical Co., Ltd.) can be used. Of these, KL-245 and KL-270, which are organically modified polysiloxanes, are preferred.

  In the resin composition 1, when the surfactant (H) contains the organically modified polysiloxane, the coating property of the composition 1 by the slit coater is remarkably improved. The so-called “sink”, in which the resist moves from the coating film edge to the center after the coating film is once applied to the substrate by the slit coater, can be eliminated by using organically modified polysiloxane.

These surfactants are preferably used in an amount of usually 5 parts by weight or less, preferably 0.01 to 2 parts by weight with respect to 100 parts by weight of the polymer (A).
((I) Other ingredients)
The composition 1 may contain the following as other components.

(Polynuclear phenol compound)
The polynuclear phenol compound is not an essential component of the composition 1, but by adding it, the alkali solubility of the composition 1 is improved, and the shape of the resist pattern can be controlled more precisely. Here, the polynuclear phenol compound means a compound having two or more independently present benzene rings and two or more phenolic hydroxyl groups in one molecule having a hydroxyl group bonded to a part of the benzene ring. . Specifically, for example, 4,4 ′-[1- [4- [1- (4-
Hydroxyphenyl) -1-methylethyl] phenyl] ethylidene] diphenol, 2,2-bis (1,5-dimethyl-4-hydroxyphenyl) propionic acid methyl ester, 4,6-bis [1- (4-hydroxy) Phenyl) -1-methylethyl] -1,3-benzenediol and the like.

  When these polynuclear phenol compounds are contained in the composition 1, the polynuclear phenol compound is usually 1 to 10 parts by weight, preferably 5 to 10 parts by weight, based on 100 parts by weight of the polymer (A). Used in. When the content of the polynuclear phenol compound in the composition 1 exceeds 10, an undercut margin may not be appropriately ensured.

<Positive radiation sensitive resin composition 2 for upper layer (Composition 2)>
The upper-layer positive radiation-sensitive resin composition 2 (hereinafter, also simply referred to as the composition 2) used in the present invention includes (D) a polymer having a phenolic hydroxyl group, (E) a quinonediazide group-containing compound, (G It is preferable that it comprises a solvent and comprises (F) a polyether resin.

The composition 2 is desirably a composition containing an additive such as a surfactant.
((D) Polymer having phenolic hydroxyl group)
Examples of the polymer having a phenolic hydroxyl group include novolak resins, polyhydroxystyrene and derivatives thereof shown below. These can be used alone or in combination. These polymers are preferred in that they function as positive resists having sensitivity in the g-line and i-line wavelength regions when used in combination with a photosensitizer comprising a quinonediazide group-containing compound.

(Novolac resin)
The novolak resin used in the present invention is an alkali-soluble resin obtained by condensing m-cresol and one or more other phenols with an aldehyde compound, and the proportion of m-cresol is all phenols. It is a novolak resin which is 40-90 mol% in the inside.

  Specific examples of the other phenols used as the raw material for the novolak resin include 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 3,4-xylenol, 3,5- Examples include xylenol and 2,3,5-trimethylphenol. These can be used alone or in combination of two or more.

Among these, 2,3-xylenol, 2,4-xylenol, 3,4-xylenol and 2,3,5-trimethylphenol can be preferably exemplified.
Preferred combinations of m-cresol and one or more other phenols include m-cresol / 2,3-xylenol, m-cresol / 2,4-xylenol, m-cresol / 2,3-xylenol. / 3,4-xylenol, m-cresol / 2,3,5-trimethylphenol and m-cresol / 2,3-xylenol / 2,3,5-trimethylphenol.

  Examples of the aldehyde compound to be condensed include formaldehyde, paraformaldehyde, acetaldehyde, benzaldehyde, o-hydroxybenzaldehyde, m-hydroxybenzaldehyde, p-hydroxybenzaldehyde, glyoxal, glutaraldehyde, terephthalaldehyde, and isophthalaldehyde. . Of these, formaldehyde and o-hydroxybenzaldehyde can be particularly preferably used.

These aldehydes can also be used alone or in combination of two or more. Preferably such an aldehyde compound is 0.4-2 mol per mol of phenols,
More preferably, it is used in an amount of 0.6 to 1.5 mol.

In the condensation reaction between phenols and aldehyde compounds, an acidic catalyst is usually used. Examples of the acidic catalyst include hydrochloric acid, nitric acid, sulfuric acid, formic acid, oxalic acid, acetic acid, methanesulfonic acid, p-toluenesulfonic acid, and the like. Such an acidic catalyst can usually be used in an amount of 1 × 10 ^{−5 to} 5 × 10 ⁻¹ mol with respect to 1 mol of phenols.

  In the condensation reaction, water is usually used as a reaction medium. However, when a heterogeneous system is formed from the initial stage of the reaction, the reaction medium is, for example, alcohols such as methanol, ethanol, propanol, butanol, propylene glycol monomethyl ether, tetrahydrofuran, etc. , Cyclic ethers such as dioxane, and ketones such as ethyl methyl ketone, methyl isobutyl ketone, and 2-heptanone can be used. These reaction media are usually used in an amount of 20 to 1,000 parts by weight per 100 parts by weight of the reaction raw material.

Although the temperature of a condensation reaction can be suitably adjusted according to the reactivity of a raw material, it is 10 to 200 degreeC normally.
As the reaction method, it is possible to appropriately employ a method of charging phenols, aldehyde compounds, acidic catalysts, etc. in a lump, and a method of adding phenols, aldehyde compounds, etc. as the reaction proceeds in the presence of acidic catalysts. it can.

As a method for recovering the novolak resin after completion of the condensation reaction, in order to remove unreacted raw materials, acidic catalyst, reaction medium, etc. existing in the system, the reaction temperature is raised to 130 ° C. to 230 ° C. and volatilized under reduced pressure. The method for removing the novolak resin and recovering the novolak resin, and the obtained novolak resin is ethylene glycol monomethyl ether acetate, methyl 3-methoxypropionate, ethyl lactate, methyl isobutyl ketone, 2-heptanone, dioxane, methanol, ethyl acetate, etc. There is a method in which a poor solvent such as water, n-hexane, n-heptane and the like is mixed, and then the resin solution layer to be separated is separated to recover a high molecular weight novolak resin.

  Further, the polystyrene-reduced weight average molecular weight (hereinafter referred to as “Mw”) of the novolak resin is from the viewpoint of workability when the composition 2 is formed, developability when used as a resist, sensitivity, and heat resistance. It is preferably from 2,000 to 20,000, particularly preferably from 3,000 to 15,000.

(Polyhydroxystyrene)
Examples of polyhydroxystyrenes that can be used in the present invention include Marka Linker M, Marka Linker CMM, Marka Linker CHM, Marka Linker MB, Marka Linker PHM-C, Marka Linker CST, Marka Linker CBA (Maruzen Petrochemical Co., Ltd.) Resin) marketed under names such as (manufactured).

((E) quinonediazide group-containing compound)
(E) As a quinonediazide group containing compound, the thing similar to the (B) quinonediazide group containing compound described by the positive type radiation sensitive resin composition 1 (composition 1) for lower layers can be used. The lower layer positive-type radiation-sensitive resin composition 2 used in the present invention may contain the quinonediazide group-containing compound alone, or may contain two or more kinds.

(E) As a preferable combination of the quinonediazide group-containing compound,
1.0 mol of 4,4 ′-[1- [4- [1- (4-hydroxyphenyl) -1-methylethyl] phenyl] ethylidene] diphenol and naphthoquinone-1,2-diazide-5-sulfonyl chloride 2 Product of esterification with 0.0 mol,
7-hydroxy-4- (4′-hydroxyphenyl) -2-methyl-2- (2 ′, 4′-dihydroxy) phenylcoumarone 1.0 mol and naphthoquinone-1,2-diazide-5-sulfonyl chloride 2 0.0 mol of esterification reaction product is mentioned.

The positive radiation sensitive resin composition 2 for the upper layer used in the present invention may contain the quinonediazide group-containing compound alone, or may contain two or more kinds.
The quinonediazide group-containing compound is usually in the range of 5 to 60 parts by weight, preferably 10 to 50 parts by weight, more preferably 15 to 35 parts by weight with respect to 100 parts by weight of the polymer (D) having a phenolic hydroxyl group. It is blended with. If the blending amount is less than 5 parts by weight, the difference in alkali dissolution rate between the unexposed part and the exposed part is hardly different, and if it exceeds 60 parts by weight, the homogeneity of the formed resist film [II] is lowered and the resolution is improved. Tend to deteriorate.

<(F) Polyether resin>
Examples of the polyether resin (F) include polyethylene glycol (trade names: PEG-400, PEG-1000 manufactured by NOF Corporation), terminal methoxy-modified polyethylene glycol (trade names: UNIOX MM-500, UNIOX MM-1000 NOF Corporation). Manufactured).

By including the polyether resin in the upper layer, the degree of intermixing between the upper layer and the lower layer can be controlled.
The positive radiation sensitive resin composition 2 for the upper layer used in the present invention may contain the polyether resin alone or may contain two or more kinds.

  In the case of containing the polyether resin, the positive radiation sensitive resin composition 2 for the upper layer used in the present invention is obtained by converting the polyether resin (F) into the polymer 100 having the (D) phenolic hydroxyl group. The content is usually 1 to 20 parts by weight, preferably 1 to 15 parts by weight, and more preferably 5 to 10 parts by weight with respect to parts by weight. By including the polyether resin (F), the degree of intermixing between the upper layer and the lower layer can be controlled.

((G) solvent)
Examples of the solvent (G) include a solvent containing at least one selected from the group consisting of 2-heptanone, 3-heptanone, 4-heptanone and cyclohexanone and / or dialkylene glycol dialkyl ether.

  Among these, the polymer (A) is insoluble or hardly soluble from the viewpoint of preventing generation of both mixed layers when the upper layer (resist layer [II]) is laminated on the lower layer (resist layer [I]). Specifically, it is preferable to use at least one kind selected from 2-heptanone, 3-heptanone, 4-heptanone and cyclohexanone and dialkylene glycol dialkyl ether. By using dialkylene glycol dialkyl ether, it is possible to prevent the nozzle from clogging due to drying of the solvent at the tip of the nozzle when coating with a slit coater described below.

  When these compositions 2 are applied on a substrate with a thickness of 5 μm or less by spin coating, the solid content concentration of the composition 2 is preferably 1 wt% to 50 wt%. %, Preferably 10% to 40% by weight. That is, when (D) the polymer having a phenolic hydroxyl group, (E) a quinonediazide group-containing compound, and when it is contained as a constituent of composition 2, (F) the total amount of the polyether resin is 100 parts by weight. The solvent is usually used in an amount of 100 to 9900 parts by weight, preferably 150 to 900 parts by weight.

  Moreover, when apply | coating the obtained composition 2 on a board | substrate with the thickness of 5 micrometers or less with a slit coater, the solid content density | concentration of the composition 2 becomes like this. Preferably it is 2 to 50 weight% normally, Preferably it is 10 weight%. It is used in the range of from 30% to 30% by weight. That is, when it is contained as a constituent of (D) a polymer having a phenolic hydroxyl group, (E) a quinonediazide group-containing compound, and composition 2, (F) a total of 100 parts by weight of the polyether resin. The solvent is usually used in an amount of 100 to 4900 parts by weight, preferably 230 to 900 parts by weight.

(Surfactant)
As the surfactant, the same surfactant as the surfactant (H) described in the lower layer resin composition 1 (composition 1) can be used.

  Such a surfactant is preferably used in an amount of 5 parts by weight or less, more preferably 0.01 to 2 parts by weight with respect to 100 parts by weight of the polymer (D) having a phenolic hydroxyl group.

((I) Other ingredients)
The composition 2 may contain the following as other components.
(Polynuclear phenol compound)
Although this compound is not an essential component of the composition 2, by adding it, the alkali solubility can be improved and the shape of the resist pattern can be controlled more precisely. As the polynuclear phenol compound, those similar to the composition 1 can be used.

  When a polynuclear phenol compound is used in the composition 2, these polynuclear phenol compounds are usually 1 to 30 parts by weight, preferably 5 to 20 parts per 100 parts by weight of the polymer having (D) a phenolic hydroxyl group. Used in parts by weight.

Next, a two-layer laminated film according to the present invention and a pattern forming method using the same will be described.
<Two-layer laminated film and pattern forming method using the same>
The two-layer laminated film according to the present invention includes a lower layer (resist layer [I]) formed from the resin composition 1 and an upper layer (resist layer [II] formed from the positive radiation-sensitive resin composition 2. )
Since the pattern forming method according to the present invention includes the step of forming the two-layer laminated film, the two-layer laminated film according to the present invention will be described below together with the pattern forming method.

That is, with reference to FIG. 1, the pattern forming method according to the present invention uses a resin composition 1 (composition 1) on the surface of a substrate 1 as a lower layer (resist layer [I]) (in FIG. 1). After the formation of the lower layer 2) (a-1), an upper layer (resist layer [II]) (upper layer 3 in FIG. 1) made of the positive radiation sensitive resin composition 2 (composition 2) is formed thereon. (A-2) Step (a) of forming a two-layer laminated film;
A step (b) of pattern exposure of the two-layer laminated film with UV light through a mask M and / or drawing with an electron beam;
(C) forming a resist pattern having a larger undercut shape by developing the two-layer laminated film that has undergone the step (b) so that the bottom of the opening of the two-layer laminated film removed by the development is larger than the opening. ,
A step (d) of depositing and / or sputtering organic or inorganic thin films 4a and 4b on the surface of the two-layer laminated film that has undergone the resist pattern forming step (c) and the substrate surface at a position corresponding to the opening;
A step (e) of lifting off the vapor deposition and / or sputtered film 4a deposited on the two-layer laminated film together with the laminated film, that is, the lower layer 2 and the upper layer 3.

  In the step (a), a two-layer laminated film according to the present invention is formed. Examples of the method for forming the two-layer laminated film include spin coating, slit coating, roll coating, screen printing, applicator and the like as methods for applying each of compositions 1 and 2 as a liquid resist to a substrate. . Further, a method of applying / drying the composition 1 or 2 on a support film and transferring the composition is also possible. These methods may be used alone or in combination, and a method for forming a two-layer laminated film suitable for the combination of the resin composition 1 and the positive radiation sensitive resin composition 2 may be used. It is preferable to select.

  The thickness of the lower layer (resist layer [I]) thus obtained is 0.1 to 3.0 μm from the viewpoint of resist film thickness control and deposition and / or sputtered film dimension control. It is preferable that it is in the range of 0.3 to 2.0 μm. When the thickness of the lower layer is less than 0.1 μm, it is difficult to control the thickness and pinholes may occur. On the other hand, when the film thickness of the lower layer exceeds 3.0 μm, diffusion in the undercut portion becomes remarkable during vapor deposition and / or sputtering, and it may be difficult to control the dimensions of the vapor deposition and / or sputtered film pattern. .

Further, the film thickness of the obtained upper layer (resist layer [II]) is preferably 0.1 to 10 μm from the viewpoint of thermal deformation patterning characteristics in the vapor deposition and / or sputtering process.
When the thickness of the upper layer is less than 0.1 μm, the surface of the upper layer is heated in the vapor deposition and / or sputtering process, and the upper portion of the undercut droops and hangs down, and there is a risk of touching the substrate surface. When the thickness of the upper layer exceeds 10 μm, the patterning time becomes long, and it may be difficult to control the dimensions of the vapor deposition and / or sputtered film pattern.

  In the step (a), when the lower layer 2 and the upper layer 3 are formed, if a mixed layer of the lower layer 2 and the upper layer 3 is generated, a development residue is generated on the substrate surface of the undercut portion after development. Is likely to occur. On the other hand, if the two layers are not mixed at all and an interface exists between the two layers, the developing solution permeates along this interface during development, and the horizontal development speed of the lower layer 2 increases, resulting in an It becomes difficult to control the horizontal size of the cut. It is possible to use a water-soluble organic substance as an intermediate layer as a means for preventing the generation of this mixed layer, but the number of processing steps increases, and the appropriate development time shifts due to a change in the film thickness of the intermediate layer. Problems such as variations in opening dimensions may occur. For these reasons, the lower layer 2 and the upper layer 3 are preferably a combination in which moderate intermixing proceeds.

Further, in the two-layer laminated film according to the present invention, in the step (c) following the step (b) in which the two-layer laminated film is subjected to pattern exposure by UV light exposure through the mask M and / or drawing with an electron beam. The lower layer 2 (resist layer [I]) is the upper layer 3 (resist layer [I]) from the point that the opening bottom of the laminated film removed portion by development forms a larger undercut resist pattern in the laminated film than the opening. It is necessary that the dissolution rate with respect to the same developer, that is, the dissolution rate with respect to the aqueous alkali solution is higher than that of the resist layer [II]).

  Further, organic or inorganic thin films 4a and 4b are deposited and / or deposited on the surface of the two-layer laminated film that has undergone the subsequent step (d), that is, the resist pattern forming step (c), and the substrate surface at a position corresponding to the opening. Alternatively, in the sputtering process, the surface of the laminated film is heated. At this time, when the heat resistance of the upper layer 3 is not sufficient and / or when the retreat amount W of the undercut portion is large, the peripheral portion drips down due to heat, and the deposited organic layer or inorganic thin film 4b is deposited and / or sputtered. Causes burrs.

  Therefore, it is preferable that the positive radiation sensitive resin composition 2 used for the upper layer 3 has heat resistance so as not to hinder the step (d). The lower layer 2 and the upper layer 3 have a recess in the undercut portion during development. It is preferable to have a margin for the development time that can sufficiently control the amount W.

  The retreat amount W of the undercut portion is, as described above, the lower layer 2 in the undercut-like region in which the opening bottom of the laminated film removal portion by development is larger than the opening as shown in FIG. Means a region obtained by subtracting the narrowest region of the opening portion derived from the upper layer 3 from the most widely receded region.

Thus, it is preferable that the combination of the composition 1 and the composition 2 in this invention is a combination which satisfies the said conditions.
Hereinafter, based on FIG. 1, the pattern forming method according to the present invention will be described more specifically for each step.

(Process (a))
First, a method for forming a lower layer (resist layer [I] (lower layer 2 in FIG. 1)) on the surface of the substrate 1 using the composition 1 as a lower layer material as shown in FIG. When the substrate surface is relatively flat, the composition 1 (solid content concentration: 1 to 50% by weight) is applied to the substrate 1 by spin coating or slit coating, and after coating, the coating film (lower layer 2) is applied. The lower layer 2 can be formed by drying the substrate 1 having it at 200 ° C. or lower, more preferably at 70 to 130 ° C.

  If the surface of the substrate 1 is uneven, the composition 1 is spin-coated on a base material such as PET (polyethylene terephthalate) for the purpose of ensuring the uniformity of the lower layer (resist layer [I]), and then a clean oven After forming into a transfer film by baking, etc., the lower layer 2 can be formed by laminating the lower layer (resist layer [I]) on the substrate 1 using a laminator. At this time, the lamination condition is adjusted according to the material of the substrate 1 and the like.

  Next, as shown in FIG. 1A-2, the upper layer (resist layer [II]) is formed on the lower layer (resist layer [I]) using the composition 2 that is the upper layer material. As a forming method, for example, the composition 2 is applied on the lower layer (resist layer [I] (lower layer 2 in FIG. 1)) by spin coating, and then dried at 200 ° C. or lower, more preferably 70 to 130 ° C. A method of forming an upper layer (resist layer [II] (upper layer 3 in FIG. 1)) is preferable.

  The composition 2 is formed into a film on a base material such as PET and then laminated on the lower layer (resist layer [I] (lower layer 2 in FIG. 1)) using a laminator, and the upper layer (resist layer [II (Upper layer 3 in FIG. 1) may be formed, and after forming a lower layer material and an upper layer material in this order on a base material such as PET, the lower layer 2 is laminated on the substrate 1 using a laminator. And the upper layer 3 may be formed at a time.

(Process (b))
Next, the two-layer laminated film composed of the lower layer 2 and the upper layer 3 is irradiated with radiation through a predetermined mask M to perform pattern exposure. As these radiation sources, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a metal halide lamp, an argon gas laser, or the like can be used. Here, the radiation means ultraviolet rays (UV light), visible rays, far ultraviolet rays, X-rays, electron beams, and the like. Among these, UV light and electron beam are preferable from the viewpoint of operability. During the pattern exposure, the radiation, the two-layer laminated film, preferably 100~1500mJ / cm ^2, more preferably irradiated such that the exposure amount of 100 to 500 mJ / cm ^2.

(Process (c))
The exposed two-layer film is developed with an alkali developer according to a dipping method, a paddle method, or a shower method to selectively dissolve and remove the exposed portion of the laminated film, as shown in FIG. A desired resist pattern as shown can be obtained. The resist pattern has a larger undercut shape at the bottom of the opening where the laminated film is removed by development than the opening.

  Examples of the developer include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, and methyl. Diethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, pyrrole, piperidine, 1,8-diazabicyclo [5,4,0] -7-undecene, 1,5-diazabicyclo [4, An aqueous solution of an alkali such as 3,0] -5-nonane can be used.

Further, an aqueous solution obtained by adding an appropriate amount of a water-soluble organic solvent such as methanol or ethanol or a surfactant to the alkaline aqueous solution can also be used as a developer.
The substrate and the resist pattern after the development treatment are rinsed using water or the like and further dried.

  It should be noted that other steps may be added in addition to the steps described above. For example, a flattening process as a base for the lower layer 2, a pretreatment process for improving the adhesion between the substrate 1 or the base and the lower layer 2, formation of an intermediate layer for controlling the mixing of the lower layer 2 and the upper layer 3, A pre-wet treatment for improving wettability before development, a post-bake step performed after development, and the like can be appropriately performed.

  The composition 1 used in the present invention and the lower layer (resist layer [I]), the composition 2 and the upper layer made thereof (resist layer [II]) have extremely good alkali solubility, and are further contained in the same developer. On the other hand, the dissolution rate of the lower layer (resist layer [I]) is faster than the dissolution rate of the upper layer (resist layer [II]), and the dissolution rate can be controlled, so that dimensional stability can be achieved with high reproducibility. An excellent undercut resist pattern can be formed.

  In addition, since the resist pattern with this undercut structure can be confirmed by observation with an optical microscope and the resist can be easily peeled off, if the desired undercut shape cannot be obtained, the resist pattern Can be peeled off and patterned again.

(Process (d))
Next, using the obtained undercut resist pattern, thin films 4a and 4b (organic thin film or inorganic thin film) are formed by vapor deposition and / or sputtering as shown in FIG. The thickness of the obtained organic thin film or inorganic thin film is not particularly limited, but the thickness of the inorganic thin film or the organic thin film is preferably smaller than the thickness of the lower layer 2 from the viewpoint of controlling these shapes.

  Further, since anisotropy occurs in the vertical direction of the obtained thin film by the vapor deposition and / or sputtering method, the positive resist opening size of the upper layer 3 and the film thickness of the lower layer 2 are adjusted for the shape control of the thin film 4b. It becomes important. Examples of the vapor deposition and / or sputtering method include PVD (physical vapor deposition) such as vacuum vapor deposition and sputtering.

(Process (e))
Next, of the thin films 4a and 4b formed in the step (d), the portion 4a formed on the two-layer laminated film is peeled off together with the two-layer laminated film to obtain a target thin film pattern 4b.

  For peeling off the resist pattern after forming the thin films 4a and 4b, a solvent generally used for peeling off the positive resist can be used as it is. That is, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monopropyl ether acetate, acetone, Ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, Ethyl 3-methoxypropionate, butyl acetate, methyl pyruvate, It can be used ethyl bottles acid.

  Further, N-methylformamide, N, N-dimethylformamide, N-methylformanilide, N-methylacetamide, N, N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, benzylethyl ether, dihexyl ether, acetonylacetone , Isophorone, caproic acid, caprylic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate, propylene carbonate, ethylene glycol monophenyl ether A high boiling point solvent such as acetate can also be used.

The resist pattern can be peeled off at room temperature, but the peeling is facilitated by raising the temperature.
In addition, the substrate having a resist pattern before peeling can be exposed to the entire surface with UV light to decompose the quinonediazide group-containing compound contained in the upper layer and the lower layer or the upper layer, thereby facilitating peeling. In this case, the stripping can be performed by simply dipping at room temperature in a solvent such as ethyl alcohol, isopropyl alcohol, or the like that hardly shows corrosiveness, or the developer described above.

  EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples. Unless otherwise specified, parts are parts by mass and% is mass%.

(Preparation example)
Preparation of Composition 1 and Composition 2 Using the following components (A) to (I), composition 1 (lower layer compositions (1-1) to (1-7)) and composition 2 (upper layer use) Compositions (2-1) to (2-7)) were prepared. These are shown in Table 2 and Table 3, respectively.

<(A) Radical polymer>
A-1: PPH-1000 (manufactured by Showa Polymer Co., Ltd.), weight average molecular weight: 8,000
A-2: PPH-1000 (manufactured by Showa Polymer Co., Ltd.), weight average molecular weight: 10,000
A-3: PPH-1000 (manufactured by Showa Polymer Co., Ltd.), weight average molecular weight: 15,000
A-4: PPH-1000 (manufactured by Showa Polymer Co., Ltd.), weight average molecular weight: 17,000
A-5: PPH-1000 (manufactured by Showa Polymer Co., Ltd.), weight average molecular weight: 22,000
A-6: PPH-7100 (manufactured by Showa Polymer Co., Ltd.), weight average molecular weight: 12,000
A-7: PPH-7200 (manufactured by Showa Polymer Co., Ltd.), weight average molecular weight: 13,000
A-8: PPH-7400 (manufactured by Showa Polymer Co., Ltd.), weight average molecular weight: 13,000
A-9: Polystyrene (manufactured by Wako Pure Chemical Industries, Ltd.), weight average molecular weight: 10,000
Each of these is a radical polymer composed of styrene as an example of the above-mentioned monomer I and / or monomer II, and the weight ratio thereof and the weight average molecular weight of the radical polymer (A) are shown in Table 1. Monomer I is 3,5-dimethyl-4-hydroxybenzylacrylamide.

<(B) Quinonediazide group-containing compound>
B-1: 4,4 ′-[1- [4- [1- (4-hydroxyphenyl) -1-methylethyl] phenyl] ethylidene] diphenol (1.0 mol) and naphthoquinone-1,2-diazide- Esterification reaction product with 1.0 mol of 5-sulfonyl chloride (Sanpo Chemical Laboratory Co., Ltd.).

<(C) Solvent>
The following were used as the solvent (C).
EL: ethyl 2-hydroxypropionate (manufactured by Wako Pure Chemical Industries, Ltd.)
<(D) Synthesis of polymer having phenolic hydroxyl group>
D-1: m-cresol (manufactured by Wako Pure Chemical Industries, Ltd.), 2,3-xylenol (manufactured by Wako Pure Chemical Industries, Ltd.) and 3,4-xylenol (manufactured by Wako Pure Chemical Industries, Ltd.) A weight ratio of 80:10:10 was mixed, and a 37% aqueous solution of formaldehyde (manufactured by Wako Pure Chemical Industries, Ltd.) was added thereto, and an oxalic acid catalyst (manufactured by Wako Pure Chemical Industries, Ltd.) was added at a weight ratio of 0.00. The cresol novolak was obtained by condensation by a conventional method using a ratio of 2. The resin was subjected to a fractionation treatment, and the low molecular region was cut to obtain a novolak resin D-1 having a weight average molecular weight of 10,000.

<(E) Quinonediazide group-containing compound>
E-1: 1.0 mol of 4,4 ′-[1- [4- [1- (4-hydroxyphenyl) -1-methylethyl] phenyl] ethylidene] diphenol and naphthoquinone-1,2-diazide- Esterification reaction product with 1.0 mol of 5-sulfonyl chloride (Sanpo Chemical Laboratory Co., Ltd.).

<(F) polyether resin>
F-1: PEG400 Polyethylene glycol (manufactured by NOF Corporation)
F-2: PEG1000 polyethylene glycol (manufactured by NOF Corporation)
F-3: UNIOX MM-500 polyethylene glycol dimethyl ether (manufactured by NOF Corporation)
F-4: UNIOX MM-1000 Polyethylene glycol dimethyl ether (manufactured by NOF Corporation)
<(G) Solvent>
The following were used as the solvent (G).
MAK: 2-heptanone (Nagase Sangyo Co., Ltd.)
MEC: Diethylene glycol methyl ethyl ether (Toho Chemical Industry Co., Ltd.)
<(H) Surfactant>
H-1: NBX-15 (manufactured by Neos) Diglycerin EO adduct perfluorononenyl ether H-2: SF-8428 (manufactured by Toray Dow Corning Silicone)
<(I) Polynuclear phenol compound>
I-1: 4,4 '-[1- [4- [1- (4-hydroxyphenyl) -1-methylethyl] phenyl] ethylidene] diphenol (Sanpo Chemical Laboratory)
<Preparation of Composition 1 (Compositions for Lower Layer (1-1) to (1-11))>
(Preparation of composition (1-1))
100 parts of the above-mentioned radical polymer A-1, 15 parts of the quinonediazide group-containing compound B-1 and 0.2 part of NBX-15 (manufactured by Neos Co., Ltd.) were added and dissolved in 1500 parts of EL. It filtered using the membrane filter and prepared the composition (1-1).

(Preparation of compositions (1-2) to (1-11))
Compositions (1-2) to (1-11) were prepared using the materials shown in Table 2 in the same procedure as in the above composition (1-1).

  The results are shown in Table 2.

<Preparation of Composition 2 (Upper Layer Compositions (2-1) to (2-7))>
(Preparation of composition (2-1))
90 parts of D-1, 25 parts of quinonediazide group-containing compound E-1, polyether resin F-
10 parts of SF 1 and 0.2 part of SF-8428 (manufactured by Toray Dow Corning Silicone Co., Ltd.) as a surfactant were uniformly dissolved in 250 parts of MAK and 60 parts of MEC, and then the pore size was 3 μm. Was used to prepare a composition (2-1) having a solid content concentration of 30%.

(Preparation of compositions (2-2) to (2-7))
It prepared in the same procedure as a composition (2-1) using the material shown in Table 3.
However, in the composition 2-6, the polynuclear phenol compound I-1 was also uniformly dissolved in 250 parts of MAK and 60 parts of MEC. Moreover, (F) polyether resin was not contained in 2-6 and 2-7.

[Example 1]
<Formation of laminated film on substrate surface>
The composition (1-1) was dropped onto a 4-inch diameter silicon wafer, spin-coated, and then baked on a hot plate at 110 ° C. for 3 minutes to obtain a resist film [I] (lower layer). Next, the composition (2-1) is dropped onto this and spin-coated, followed by 3 hours at 110 ° C. on a hot plate.
By baking for a minute, a resist film [II] (upper layer) was formed to obtain a two-layer laminated film.

<Exposure and development>
The substrate with good coatability produced in the above manner was exposed and alkali developed, and patterning evaluation was performed. The evaluation conditions are as follows.

Exposure machine: Mask Aligner MA150
(Contact aligner, manufactured by SUSS Microtex)
Exposure amount: 150 mJ / cm ² (near 420 nm)
Exposure mode: Hard contact exposure Development: Performed by dipping in an aqueous 2.38 mass% tetramethylammonium hydroxide solution. The development time was changed every 10 seconds.

Rinse: Rinse with running water of ultrapure water for 1 minute, air blow, and dry.
After development, the pattern shape was confirmed with an optical microscope and a scanning electron microscope, if necessary. The evaluation pattern was a 50 μm × 50 μm square pattern with a space between adjacent holes of 50 μm (pitch 50 μm).

<Undercut shape>
Evaluation: Evaluated according to the following criteria and indicated by ◎, ○, ×. The results are shown in Table 4.
Undercut shape A: Observed with an optical microscope, an undercut having a uniform width can be confirmed around the nuki pattern even if the development time is extended.

Undercut shape ○: By observing with an optical microscope, non-uniform undercut can be confirmed around the pattern when the development time is extended.
Undercut shape ×: Observed with an optical microscope, no undercut can be confirmed around the nuki pattern regardless of the development time.

<Development margin at undercut>
Evaluation: Evaluated according to the following criteria and indicated by ◎, ○, ×. The results are shown in Table 4.
In the patterning evaluation, the undercut width (the difference between the length of the widest opening portion of the lower layer and the length of the narrowest portion of the opening of the upper layer) is measured.
Development margin undercut region ◎: undercut width is 10μm developing time (t ₂₎ the difference between the undercut width is 0μm development time _{(t 1) (t 2 -t} 1) is more than 30 seconds development margin when the undercut portion ○: undercut width is 10μm developing time (t ₂₎ the difference between the developing time (t ₁₎ which undercut width is 0μm (t ₂ -t ₁₎ is more than 15 seconds When it is less than 30 seconds, the development margin of the undercut portion ×: difference (t ₂ −t ₁ ) between the development time (t ₂ ) at which the undercut width is 10 μm and the development time (t ₁ ) at which the undercut width is 0 μm Is less than 5 seconds [Examples 2-16, Comparative Examples 1-2]
Using the composition shown in Table 2 (lower layer composition 1) and the composition shown in Table 3 (upper layer composition 2), evaluation was performed in the same manner as in Example 1. The results are shown in Table 4.

FIG. 1 is a schematic view of a pattern forming method according to the present invention. FIG. 2 is a diagram defining the amount of pattern retreat according to the present invention. FIG. 3 is a schematic view of a conventional pattern forming method. FIG. 4 is a schematic view of a conventional pattern forming method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Substrate 2 ... Lower layer 3 ... Upper layer 4a ... Deposition and / or sputtering film 4b ... Deposition and / or sputtering film 5 ... Resist 6a ... Deposition and / or sputtering film 6b ... Deposition and / or sputtering film 7 ... Resist 8a ... Deposition And / or sputtered film 8b ... deposition and / or sputtered film M ... mask W ... retraction amount

Claims (8)

(A) a lower layer (resist layer I) obtained from a resin composition 1 containing a polymer having a structural unit represented by the following general formula (1) and (C) a solvent;
And (D) a polymer having a phenolic hydroxyl group, (E) a quinonediazide group-containing compound, and (G) an upper layer (resist layer II) obtained from a positive radiation-sensitive resin composition 2 containing a solvent. A two-layer laminated film.

(Wherein R ¹ is a hydrogen atom or a methyl group, R ² is a single bond methylene group or an alkylene group having 2 to ³ carbon atoms, R ³ is an alkyl group having 1 to 4 carbon atoms, and m is It is an integer from 0 to 3.) The resin composition 1 further comprises (B) a quinonediazide group-containing compound,
The two-layer laminated film according to claim 1, comprising: The upper layer (resist layer II) of the two-layer laminated film is
(D) a polymer having a phenolic hydroxyl group;
(E) a quinonediazide group-containing compound;
(F) a polyether resin;
(G) The two-layer laminated film according to claim 1 or 2, which is obtained from a positive radiation-sensitive resin composition 2 containing a solvent. In the positive radiation sensitive resin composition 2,
The two-layer laminated film according to claim 3, wherein the polyether resin (F) is polyethylene glycol or polyethylene glycol modified with terminal alkoxy. In the resin composition 1,
The polymer (A) is insoluble in water, soluble in an alkaline aqueous solution, and further insoluble or hardly soluble in the solvent (G). Two-layer laminated film. In the positive radiation sensitive resin composition 2,
The solvent (G) is a solvent containing at least one selected from the group consisting of 2-heptanone, 3-heptanone, 4-heptanone and cyclohexanone and / or a dialkylene glycol dialkyl ether. 7. The two-layer laminated film according to any one of 6. A method of forming a pattern on a substrate surface,
(A) a lower layer (resist layer [I]) obtained from the resin composition 1 containing a polymer containing the structural unit represented by the general formula (1) and (C) a solvent, and (D) phenolic Upper layer (resist layer [II]) obtained from positive-type radiation-sensitive resin composition 2 containing a polymer having a hydroxyl group, (E) a quinonediazide group-containing compound, (F) a polyether resin, and (G) a solvent.
A pattern forming method comprising a step of forming a two-layer laminated film. (A) After forming a lower layer on the substrate surface using the resin composition 1, an upper layer (resist layer) is formed on the lower layer (resist layer [I]) using the positive radiation sensitive resin composition 2. [II]) to form a two-layer laminated film;
(B) pattern-exposing the two-layer laminated film by exposure with UV light and / or drawing with an electron beam;
(C) A step of developing the two-layer laminated film that has undergone the step (b) to form a resist pattern having an undercut shape in which the bottom of the opening of the two-layer laminated film removed by the development is larger than the opening. When,
(D) a step of depositing and / or sputtering an organic thin film or an inorganic thin film on the surface of the two-layer laminated film that has undergone the resist pattern forming step (c) and the substrate surface at a position corresponding to the opening;
The pattern forming method according to claim 7, further comprising a step (e) of peeling the vapor deposition film and / or the sputtered film deposited on the two-layer laminated film together with the two-layer laminated film.

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