JP4752754B2 - Two-layer laminated film and pattern forming method using the same - Google Patents

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 a lift-off method suitably used for photofabrication such as wiring formation and electrode formation for semiconductors, electronic components, display panels, touch panels 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. For this reason, control of the undercut shape has been demanded.

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

An object of this invention is to provide the resist film which can obtain the film-forming layer without a burr | flash on the substrate surface easily, and the pattern formation method which forms this.
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. The object is to easily form a film-forming layer without burr obtained by exposure and development.

  The present invention relates to a lower layer (resist layer [I]) obtained from a specific positive radiation-sensitive composition 1, and an upper layer (resist layer) obtained from a specific positive radiation-sensitive composition 2 on the lower layer. The above problem was solved by forming a pattern by a lift-off method using a two-layer laminated film comprising [II]).

That is, the two-layer laminated film according to the present invention contains (A) the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2), and the total structural unit constituting the structural layer is 100 wt. %, A lower layer obtained from a positive radiation sensitive resin composition 1 containing a polymer having a carboxyl group-containing structural unit of less than 1% by weight, (B) a quinonediazide group-containing compound, and (C) a solvent. (Resist layer [I]);
And (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 (F) a solvent. It is characterized by.

The pattern forming method according to the present invention includes (A) the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2), and the total structural unit constituting the structural unit is 100. It is obtained from a positive radiation sensitive resin composition 1 containing a polymer having a carboxyl group-containing structural unit of less than 1% by weight, (B) a quinonediazide group-containing compound, and (C) a solvent. A lower layer (resist layer [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 (F) a solvent. It includes a step of forming a layer laminated film.

The pattern forming method according to the present invention includes:
(A) After forming a lower layer (resist layer [I]) from the positive radiation sensitive resin composition 1 on the substrate surface, the upper layer (from the positive radiation sensitive resin composition 2 on the resist [I] ( Forming a resist layer [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) developing the two-layer laminated film to form a resist pattern having an undercut shape in which the bottom of the removed portion of the two-layer laminated film by the development is larger than the opening;
(D) An organic thin film on a substrate having a two-layer laminated film forming the resist pattern on the surface of the two-layer laminated film having undergone the resist pattern forming step (c) and on the substrate surface at a position corresponding to the opening. Or a process of depositing and / or sputtering an inorganic thin film;
(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.

  In the positive radiation sensitive resin composition 1, the polymer (A) is preferably insoluble in water, soluble in an alkaline aqueous solution, and insoluble or hardly soluble in the solvent (F). .

  In the positive radiation sensitive resin composition 2, the solvent (F) is a solvent containing at least one selected from 2-heptanone, 3-heptanone, 4-heptanone and cyclohexanone and / or dialkylene glycol dialkyl ether. It is preferable.

The film thickness of the lower layer (resist layer [I]) is preferably in the range of 0.1 μm to 3 μm, and the film thickness of the upper layer (resist layer [II]) is preferably in the range of 0.1 μm to 10 μm. .
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. The organic thin film or inorganic thin film in the step (d) includes a DLC (Diamond Like Carbon) film, SiO ₂ , SiN, Au, Pd, Ag, Pt, Cu, Cr, Al, Ta, Ni, Cr, TiN, TiC, ITO, such as 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.

  In particular, the present invention forms a two-layer laminated film comprising a lower layer formed using a specific positive radiation sensitive resin composition 1 and an upper layer formed using a specific positive radiation sensitive resin composition 2. By the pattern forming 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 is most suitable 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 contains (A) the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2), and the total structural unit constituting the structural unit is 100% by weight. A lower layer (resist) obtained from a positive radiation sensitive resin composition 1 containing a polymer having a carboxyl group-containing structural unit of less than 1% by weight, (B) a quinonediazide group-containing compound, and (C) a solvent. Layer [I]),
And (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 (F) a solvent. It is characterized by.

First, the positive radiation sensitive resin compositions 1 and 2 used in the present invention will be specifically described.
<Positive radiation sensitive resin composition 1 for lower layer (Composition 1)>
The positive radiation sensitive resin composition 1 (hereinafter also simply referred to as the composition 1) used in the present invention is represented by (A) the structural unit represented by the general formula (1) and the general formula (2). 1 structural unit having a carboxyl group when the structural unit is contained and the total structural unit is 100% by weight.
The polymer which is less than% by weight, (B) a quinonediazide group-containing compound, and (C) a solvent.

((A) a structural unit containing a structural unit represented by the general formula (1) and a structural unit represented by the general formula (2), and having a carboxyl group when the total constituting structural unit is 100% by weight In which the polymer is less than 1% by weight)
(A) In the present invention, the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2) are contained, and the carboxyl group is present when the total structural unit constituting the composition unit is 100% by weight. A polymer having a structural unit of less than 1% by weight (hereinafter referred to as “polymer (A)”) is a general formula (1) of a radically polymerizable compound having a phenolic hydroxyl group derived from monomer I as an essential component. And a structural unit represented by the general formula (2) of a radically polymerizable compound having an alcoholic hydroxyl group derived from the monomer II, (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 bonds It is composed of a repeating unit obtained by cleaving a carbon-carbon double bond with a structural unit derived from the monomer III as another radical polymerizable compound composed of a polymerizable compound, a fatty acid vinyl or the like. Furthermore, you may include the structural unit derived from the monomer IV as a radically polymerizable compound which has a carboxyl group in the ratio of less than 1 weight% of a polymer (A).

  Monomer I or monomer II is essential for imparting a suitable alkali solubility and polarity to composition 1 and imparting a polarity that allows slight intermixing with the upper layer film. That is, when the lower layer containing the composition I 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 It is practically used that the desired undercut shape can be controlled within the desired development time range and that it does not substantially dissolve in the rinsing step with deionized water after development. Is important. Moreover, moderate polarity is important in the affinity to the alkali developer and the adhesion to the substrate, but the most important thing is that the composition 2 constituting the upper layer is formed between the lower layer and the upper layer when formed on the lower layer. It is to suppress intermixing. That is, intermixing is suppressed by setting the polarity of the composition I constituting the lower layer high and providing a difference in polarity with each component of the composition II 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.

  Also, if intermixing does not proceed at all between the upper and lower layers, an interface is formed between the upper and lower layers, the upper layer peels off at the interface during development, or development proceeds significantly only at the interface, and undercutting occurs. It becomes difficult to control the shape.

(Monomer I)
Specific examples of the monomer I of the radical polymerizable compound that is a structural unit of the general formula (1) having a phenolic hydroxyl group include p-hydroxystyrene, m-hydroxystyrene, o-hydroxystyrene, α-methyl-p-. Hydroxystyrene, α-methyl-m-hydroxystyrene, α-methyl-o-hydroxystyrene, 4-isopropenylphenol, 2-allylphenol, 4-allylphenol, 2-allyl-6-methylphenol, 2-allyl- Examples include 6-methoxyphenol, 4-allyl-2-methoxyphenol, 4-allyl-2,6-dimethoxyphenol, 4-allyloxy-2-hydroxybenzophenone, and the like. These compounds can be used alone or in combination of two or more. Among these, p-hydroxystyrene, 4-isopropenylphenol and the like are preferable.

(Monomer II)
Specific examples of the monomer II of the radical polymerizable compound that is a structural unit of the general formula (2) having an alcoholic hydroxyl group include hydroxylalkyl such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate. Examples thereof include those that produce an alcoholic hydroxyl group by hydrolysis after polymerization with an ester or a fatty acid vinyl such as vinyl formate, vinyl acetate, or vinyl propionate. These compounds can be used alone or in combination of two or more. Among these, hydroxyalkyl esters are preferable, and 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, and the like are more preferable.

(Monomer III)
Monomer III is mainly intended to moderately control the mechanical properties of the polymer,
It is also used for the purpose of controlling the glass transition temperature of the polymer.

  The monomer III is a monomer other than the monomer I and the monomer II 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.

(Monomer IV)
Monomer IV is a monomer of a radical polymerizable compound that becomes a structural unit having a carboxyl group, and specifically, monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; maleic acid, fumaric acid, citraconic acid, Dicarboxylic acids such as mesaconic acid and itaconic acid; (meth) acrylic acid derivatives having a carboxyl group such as 2-malenoyloxyethyl methacrylate, 2-succinoloyloxyethyl methacrylate, 2-hexahydrophthaloylethyl methacrylate, etc. Is mentioned.

  These compounds can be used alone or in combination of two or more. It is preferable that the polymer (A) of the present invention does not contain the monomer IV because the development rate with alkali can be easily controlled and an arbitrary undercut shape can be obtained.

  Thus, the polymer (A) used in the present invention is obtained by radical polymerization of the essential monomer I and monomer II, and further monomer III, and if necessary, monomer IV in a proportion of less than 1% by weight. (Co) polymers produced. Among these (co) polymers, a copolymer obtained by radical polymerization of the monomer I, the monomer II, and the monomer III is preferable.

When the polymer (A) is a copolymer obtained by radical polymerization of the monomer I, monomer II and monomer III, the constituent unit content of each monomer is:
The monomer I unit content is usually 20 to 70% by weight, preferably 35 to 55% by weight, the monomer II unit content is usually 5 to 60% by weight, preferably 15 to 40% by weight, and the monomer III The unit content is usually 5 to 50% by weight, preferably 5 to 40% by weight.

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.
When the polymer (A) is a copolymer obtained by radical polymerization of the monomer I, monomer II, monomer III, and monomer IV,
The monomer I unit content is usually 20 to 70% by weight, preferably 35 to 55% by weight,
The monomer II unit content is usually 5 to 60% by weight, preferably 15 to 40% by weight,
The monomer III unit content is usually 5 to 50% by weight, preferably 5 to 40% by weight,
The monomer IV unit content is less than 1% by weight.
The polymer (A) preferably has a monomer IV unit content of 0% by weight.

  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;
Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone, diacetone alcohol;
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.

  In addition, the molecular weight of the polymer (A) is determined from the viewpoint of developability, adhesion, etc. in the lower layer (resist layer [I]) formed using the resulting radiation-sensitive resin composition 1 (weight average molecular weight) The weight average molecular weights in the specification are all polystyrene-converted values according to the GPC method.) Is preferably 2000 to 100,000, more preferably 5,000 to 50,000. When the weight average molecular weight is less than 2,000, the developing time is too short. On the other hand, when it exceeds 100,000, the developing time is too long, and the resolution tends to be remarkably lowered.

  The polymer (A) is preferably insoluble in water and soluble in an aqueous alkaline 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 (F) 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, the polymer (A) is preferably dissolved in an amount of 5 g or more. By using such a polymer (A), it can have a moderate alkali solubility and a polarity that allows slight intermixing with the upper layer, and line / space = 10.
When forming fine wiring of μm / 10 μm or less, the undercut can be controlled by 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 (F) means that the polymer (A) is not substantially dissolved in the solvent (F) 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 (F) described later, for example, 100 g of 2-heptanone at 25 ° C.
((B) quinonediazide group-containing compound)
The quinonediazide group-containing compound actually has a difference (t2−t1) between the development time (t1) at which the retraction amount W of the undercut portion of the two-layer resist film becomes 0 μm and the development time (t2) at 10 μm. It is added to ensure that it is long enough not to cause a problem in the manufacturing process, for example, 20 seconds or longer. Here, the retraction amount W of the undercut portion is, as shown in FIG. 2, the lower layer 2 in the region of the undercut shape in which the bottom of the two-layer laminated film removal portion by development is larger than the opening. 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.

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 .; [(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 Or tris (4-hydroxyphenyl) methane, bis (4-hydroxy-3,5-dimethylphenyl) -4-hydroxyphenylmethane, 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- Hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3,4-dihydroxyphenylmethane, etc .; or bis (cyclohexylhydroxyphenyl) hydroxyphenylmethane or its methyl-substituted 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- Chlohexyl-4-hydroxy-2-methylphenyl) -4-hydroxyphenylmethane, bis (3-cyclohexyl-2-hydroxyphenyl) -3-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-3-methylphenyl) ) -4-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-3-methylphenyl) -3-hydroxyphenylmethane, bis (5-cyclohexyl-4-hydroxy-3-methylphenyl) -2-hydroxyphenyl Methane, bis (3-cyclohexyl-2-hydroxyphenyl) -4-hydroxyphenylmethane, bis (3-cyclohexyl-2-hydroxyphenyl) -2-hydroxyphenylmethane, bis (5-cyclohexyl-2-hydroxy-4-) Methylph Nyl) -2-hydroxyphenylmethane, bis (5-cyclohexyl-2-hydroxy-4-methylphenyl) -4-hydroxyphenylmethane, etc .; or 4,4 ′-[1- [4- [1- (4- Hydroxyphenyl) -1-methylethyl] phenyl] ethylidene] diphenol;
7-hydroxy-4- (4′-hydroxyphenyl) -2-methyl-2- (2 ′, 4′-dihydroxy) phenylcoumarone; or novolak resin, pyrogallol-acetone resin, homopolymer of p-hydroxystyrene or A copolymer with a monomer copolymerizable therewith; or a compound having a hydroxyl group or an amino group, such as 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 mol of methylethyl] phenyl] ethylidene] diphenol and 1.0 mol of naphthoquinone-1,2-diazide-5-sulfonyl chloride is preferred.

The (B) quinonediazide group-containing compound is usually in the range of 1 to 40 parts by weight, preferably 5 to 30 parts by weight, and more preferably 5 to 20 parts by weight with respect to 100 parts by weight of the (A) radical polymer. Blended. When 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 when it exceeds 40 parts by weight, the adhesion of the resist film [I] obtained to the substrate may be lowered. .
((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 added. These solvents can be used alone or in combination of two or more. Of these, ethyl 2-hydroxypropionate is preferred.

In the case of applying the obtained composition 1 on a substrate by a spin coat method, these solvents have a solid content concentration of usually 1 to 50% by weight when applied to 5 μm or less. Preferably it is used in the range of 5 wt% to 25 wt%. That is, the solvent is usually used in an amount of 100 to 10,000 parts by weight, preferably 300 to 2000 parts by weight, based on 100 parts by weight of the total of the polymer (A) and the quinonediazide group-containing compound (B).
((G) 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. In the positive radiation sensitive resin composition 1, when the surfactant (G) contains an organically modified polysiloxane, the coating property using a slit coater is remarkably improved. The so-called “sink”, in which the resist moves from the edge of the coating film 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. 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.

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 (A) radical polymer.
(Other ingredients)
The composition 1 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, alkali solubility is improved and the shape of the resist pattern can be controlled. 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- And dimethyl-4-hydroxyphenyl) propionic acid methyl ester, 4,6-bis [1- (4-hydroxyphenyl) -1-methylethyl] -1,3-benzenediol, and the like.
These polynuclear phenol compounds are generally used in an amount of 1 to 30 parts by weight, preferably 5 to 20 parts by weight, based on 100 parts by weight of the polymer (A).
<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 composition 2) used in the present invention comprises (D) a polymer having a phenolic hydroxyl group, (E) a quinonediazide group-containing compound, (F It is desirable that the composition be composed of a solvent and, if necessary, (H) contain other additives such as a radical polymer having a hydroxyl group and / or a carboxyl group and a surfactant as other components.
((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.

(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 10-200 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.

  After completion of the condensation reaction, in order to remove unreacted raw materials, acidic catalyst, reaction medium, etc. present in the system, the reaction temperature is increased to 130 ° C. to 230 ° C., volatile components are removed under reduced pressure, and novolak resin is obtained. And after dissolving the obtained novolak resin in a good solvent such as ethylene glycol monomethyl ether acetate, methyl 3-methoxypropionate, ethyl lactate, methyl isobutyl ketone, 2-heptanone, dioxane, methanol, ethyl acetate, etc. There is also a method of mixing a poor solvent such as water, n-hexane, n-heptane, etc., and then separating the precipitated resin solution layer 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 Markalinker M, Markalinker CMM, Markalinker CHM, Markalinker MB, Markalinker PHM-C, Markalinker CST, Markalinker 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.

(E) As a preferable combination as a 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 having the (E) 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) solvent)
The solvent (F) is a solvent containing at least one selected from 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 the 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 the obtained composition 2 is applied on a substrate to a thickness of 5 μm or less by spin coating, the solid content concentration of the composition 2 is preferably usually 1% by weight to 50% by weight, preferably Is used in the range of 5 to 30% by weight. That is, the solvent is usually 100 to 2000 parts by weight, preferably 150 to 900 parts by weight based on 100 parts by weight of the total of the (D) polymer having a phenolic hydroxyl group and the (E) quinonediazide group-containing compound. used.

Moreover, when apply | coating the obtained composition 2 to 5 micrometers or less with a slit coater on a board | substrate,
The solid content concentration of the composition 2 is preferably used in a range of usually 2 wt% to 50 wt%, preferably 10 wt% to 30 wt%. That is, the solvent is usually 100 to 5000 parts by weight, preferably 230 to 900 parts by weight, based on 100 parts by weight of the total of the (D) polymer having a phenolic hydroxyl group and the (E) quinonediazide group-containing compound. used.
((H) 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, alkali solubility is improved and the shape of the resist pattern can be controlled. As the polynuclear phenol compound, those similar to the composition 1 can be used.

These polynuclear phenol compounds are generally used in an amount of 1 to 30 parts by weight, preferably 5 to 20 parts by weight, per 100 parts by weight of the polymer (D) having a phenolic hydroxyl group.
(Surfactant)
As the surfactant, those similar to the surfactant (G) described in the positive radiation sensitive resin composition 1 for the lower layer (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.

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 comprises a lower layer (resist layer [I]) formed from the positive radiation sensitive resin composition 1 and an upper layer (resist layer [I]) formed from the positive radiation sensitive resin composition 2 ( Resist layer [II]),
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 is applied to the surface of the substrate 1 from the positive radiation sensitive resin composition 1 (composition 1) to the lower layer (resist layer [I]) (FIG. In FIG. 1, after forming 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. Forming (a-2) and forming a two-layer laminated film (a);
A step (b) of pattern exposure by exposing the 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 laminated film so that the bottom of the removed portion of the laminated film 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 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 deposited and / or sputtered film 4a deposited on the 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. Here, by selecting a combination of the positive type radiation sensitive resin composition 1 and the positive type radiation sensitive resin composition 2, as a method of forming the two-layer laminated film, each of the compositions 1 and 2 is liquid. Examples of the method of applying the resist to the substrate include a spin coating method, a slit coating method, a roll coating method, a screen printing method, and an applicator method. 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.

  The film thickness of the lower layer (resist layer [I]) thus obtained is 0.1 to 3 μm from the viewpoints of resist film thickness control and vapor deposition and / or sputtered film dimension control. Is more preferable, and the range of 0.3 to 2 μm is more preferable. If the thickness of the lower layer is less than 0.1 μm, it is difficult to control the thickness, and pinholes may occur. When the film thickness of the lower layer exceeds 3 μm, diffusion at 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 film thickness of the upper layer is less than 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 film thickness of the upper layer exceeds 20 μm, the patterning time becomes long, and it may be difficult to control the dimensions of the vapor deposition and / or the 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 to prevent this mixed layer, but the number of processing steps increases, and the appropriate development time shifts due to the change in the film thickness of the intermediate layer, resulting in resist opening. Problems such as variations in dimensions are likely to occur. For these reasons, the materials used for the lower layer 2 and the upper layer 3 are preferably a combination in which moderate intermixing proceeds.

  In the two-layer laminated film according to the present invention, in the subsequent step (c), a resist pattern having an undercut shape in which the bottom of the laminated film removed portion by development is larger than the opening in the laminated film is formed. Therefore, it is preferable that the lower layer 2 (resist layer [I]) has a higher dissolution rate in the same developer, that is, a higher dissolution rate in an aqueous alkali solution than the upper layer 3 (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. Note that, as described above, the retreat amount W of the undercut portion refers to the lower layer 2 in the undercut-like region in which the bottom of the laminated film removal portion by development is larger than the opening as shown in FIG. It 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, as shown in FIG. 1 (a-1), a lower layer (resist layer [I] (lower layer 2 in FIG. 1)) is formed on the substrate surface using the composition 1 as the lower layer material. Is relatively flat, the composition 1 (solid content: 5 to 50% by weight) is applied to the substrate 1 by spin coating or slit coating, and the substrate having the coating film (lower layer 2) after coating is applied. The lower layer 2 can be formed by drying 1 at 200 ° C. or lower, more preferably 70 to 130 ° C.

  If the surface of the substrate 1 is uneven, spin coat 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 bake in a clean oven or the like. Then, 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 layered 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 multilayer 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 laminated film is developed with an alkali developer according to a dipping method, paddle method, or shower method to selectively dissolve and remove the exposed portion of the laminated film, as shown in FIG. Desired resist pattern can be obtained. The resist pattern has a larger undercut shape at the bottom of the portion where the laminated film is removed by development compared to 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 laminated film is peeled off together with the laminated film to obtain a target thin film pattern 4b.

For removing the resist pattern after forming the thin films 4a and 4b, a solvent generally used for removing a 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, Ethyl bottle acid and the like can be mentioned. 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 performance can be improved 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, “part” means “part by weight” and “%” means “% by weight”.
(Preparation example)
Preparation of Composition 1 and Composition 2 Using the following components (A) to (H), composition 1 (lower layer compositions (1-1) to (1-7)) and composition 2 (upper layer use) Compositions (2-1) to (2-2)) were prepared. These are shown in Table 2 and Table 3, respectively.
<(A) Polymer>
(Synthesis of Polymer A-1):
After substituting a flask equipped with a dry ice / methanol reflux and a thermometer with nitrogen, charged with 3.0 g of 2,2′-azobisisobutyronitrile as a polymerization initiator and 150 g of ethyl 2-hydroxypropionate as a solvent, Stir until the polymerization initiator is dissolved. Subsequently, 44 g of 4-isopropenylphenol (monomer a1), 24 g of 2-hydroxyethyl acrylate (monomer b1) and 32 g of n-butyl acrylate (monomer d1) were charged, and then gently stirred. Thereafter, the temperature of the solution was raised to 70 ° C., and polymerization was carried out at this temperature for 3 hours. Next, 1.5 g of 2,2′-azobisisobutyronitrile was added as a polymerization initiator, and the polymerization was further continued at 70 ° C. for 3 hours. Then, after cooling to room temperature and replacing the inside of the flask with air, 150 mg of p-methoxyphenol was added. The reaction product was dropped into a large amount of methanol to solidify the reaction product. The coagulated product was washed with water, redissolved in tetrahydrofuran having the same weight as the coagulated product, and coagulated again with a large amount of methanol. After this re-dissolution / coagulation operation was carried out three times in total, the obtained coagulated product was vacuum-dried at 40 ° C. for 48 hours to obtain radical polymer A-1. Table 1 shows.

(Synthesis of Polymers A-2 to A-12):
Synthesis was performed in the same procedure except that the monomer types listed in Table 1 were used in A-1, and radical polymers A-2 to A-12 were obtained. Table 1 shows.
<(B) Quinonediazide group-containing compound>
B-1: 1 mol of 4,4 ′-[1- [4- [1- (4-hydroxyphenyl) -1-methylethyl] phenyl] ethylidene] diphenol and naphthoquinone-1,2-diazide-5 Esterification reaction product with 1.0 mol of sulfonyl chloride.
<(C), (F) Solvent>
The following were used as the solvent.
MAK: 2-heptanone EDM: diethylene glycol methyl ethyl ether EL: ethyl 2-hydroxypropionate BAcO: butyl acetate <(G) surfactant>
G-1: KL-270 (manufactured by Kyoeisha) Organically modified polysiloxane G-2: NBX-15 (manufactured by Neos) Diglycerin EO adduct perfluorononenyl ether G-3: SF-8428 (Toray Dow Corning)・ Silicone Co., Ltd.)
<(D) Synthesis of polymer having phenolic hydroxyl group>
D-1: m-cresol, 2,3-xylenol, and 3,4-xylenol were mixed at a weight ratio of 80:10:10, formalin was added thereto, and the mixture was condensed by an ordinary method using an oxalic acid catalyst. The cresol novolak was obtained. The resin was subjected to a fractionation treatment, and the low molecular weight 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 mol of 4,4 ′-[1- [4- [1- (4-hydroxyphenyl) -1-methylethyl] phenyl] ethylidene] diphenol and naphthoquinone-1,2-diazide-5 Esterification reaction product with 1.0 mol of sulfonyl chloride.
<(H) Polynuclear phenol compound>
H-1: 4,4 ′-[1- [4- [1- (4-hydroxyphenyl) -1-methylethyl] phenyl] ethylidene] diphenol <Composition 1 (Lower layer composition (1-1) Preparation of (1-13))>
(Composition (1-1) (Preparation))
100 parts of the above radical polymer A-1, 10 parts of the quinonediazide group-containing compound B-1, 0.2 parts of the surfactant G-1, and H-1: 4,4 ′ as the other component (H) -[1
-After adding 10 parts of [4- [1- (4-hydroxyphenyl) -1-methylethyl] phenyl] ethylidene] diphenol and 1500 parts of EL and dissolving, it was filtered using a membrane filter having a pore size of 1 μm, and the composition A product (1-1) was prepared. It shows in Table 2.

(Preparation of compositions (1-2) to (1-13))
It prepared in the same procedure as a composition (1-1) using the material shown in Table 2.
<Preparation of Composition 2 (Upper Layer Compositions (2-1) to (2-4))>
(Preparation of composition (2-1))
90 parts D-1, 25 parts quinonediazide group-containing compound E-1, H-1: 4,4 ′-[1- [4- [1- (4-hydroxyphenyl) -1-methyl as other components ethyl]
Phenyl] ethylidene] diphenol 15 parts, G-3: SF-8428 (manufactured by Dow Corning Toray Silicone Co., Ltd.) 0.2 parts, and MAK 180 parts uniformly dissolved in MAK 180 parts. Filtration was performed using a filter to prepare a composition (2-1) having a solid content of 35%.
(Preparation of compositions (2-2) to (2-4))
It prepared in the same procedure as a composition (2-1) using the material shown in Table 2.

(Example)
<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 100 ° C. for 10 minutes to obtain a resist film [I] (lower layer). Next, the composition (2-1) was dropped on this and then spin-coated and baked on a hot plate at 100 ° C. for 5 minutes to form a resist film [II] (upper layer) to obtain a two-layer laminated film .
<Applicability>
After forming the lower layer and after forming the upper layer, the surface state of the coating film was observed with an optical microscope.
The evaluation was performed according to the following criteria, and the evaluation results were indicated by ○ and ×. The results are shown in Table 4.
Coating property ○: A uniform coating film was obtained on the entire surface of the coating substrate.
X: Peeling, holes, etc. were observed, and a uniform coating film could not be obtained on the entire coated substrate.
About the board | substrate which has a coating film with favorable applicability | paintability, the film thickness of the lower layer and the upper layer was measured with the stylus type film thickness meter. The film thickness of the upper layer was determined by subtracting the film thickness of the lower layer from the film thickness of the two-layer film. The results are shown in Table 4.
<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: 500 mJ / cm ² (near 420 nm)
Exposure mode: hard contact exposure Development: The substrate exposed under the above conditions was dipped in a 2.38 wt% aqueous solution of tetramethylammonium hydroxide and developed by swinging. 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).
<Developability of upper layer>
Evaluation: Evaluated according to the following criteria, and indicated by ○ and ×. The results are shown in Table 4.

Developability of upper layer: Resolved without development remaining, and the removal pattern of the upper layer can be observed with an optical microscope, and one side of the nuki pattern can be patterned with 50 ± 10 μm.
Developability of upper layer ×: Regardless of the development time, there is an undeveloped residue and / or one side of the nuki pattern cannot be patterned with 50 ± 10 μm within the 4 inch diameter substrate surface.
<Undercut width>
Evaluation: Evaluated according to the following criteria and indicated by ◯, Δ, ×. The results are shown in Table 4.
In the patterning evaluation, the undercut width (the difference between the length of the narrowest portion of the opening in the upper layer and the length of the portion of the widest opening in the lower layer) is measured.

○: Development time (t1) when the undercut width is 0 μm and ~ undercut width is
When the difference (t2−t1) in the development time (t2) to 10 μm is 20 seconds or more Δ: The development time (t1) at which the undercut width becomes 0 μm and the undercut width is
When the difference (t2−t1) in the development time (t2) that becomes 10 μm is 10 seconds or more and less than 20 seconds ×: The development time (t1) when the undercut width becomes 0 μm and the undercut width is
When the difference (t2−t1) in the development time (t2) to 10 μm is less than 10 seconds <Coating evaluation with a slit coater>
<Evaluation of coating film shrinkage>
After applying the lower layer to a 15 cm square glass substrate using a slit coater, the edge of the coating film was observed.
Evaluation was made according to the following criteria, and the results are shown in Table 4.

Coating film shrinkage ○: Immediately after coating, the edge of the coating film does not shrink at all
(Triangle | delta): The edge of a coating film shrinks about 1 mm immediately after application | coating.
X: Immediately after application, the edge of the coating film shrinks by 1 mm or more.
<Nozzle clogging evaluation>
The upper layer was applied to a 15 cm square glass substrate with a slit coater. The nozzle clogging when this was repeated a plurality of times was evaluated according to the following criteria, and the results are shown in Table 4. .

Nozzle clogging ○: 3 or more sheets can be applied continuously.
Δ: Can be applied continuously to 1 to 3 sheets
×: Neither can be applied.
(Examples 2-11, Comparative Examples 1-5)
Evaluation was performed in the same manner as in Example 1 using the composition shown in Table 2 (lower layer composition) and the composition shown in Table 3 (upper layer composition). 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 (10)

(A) A structure containing a structural unit represented by the following general formula (1) and a structural unit represented by the following general formula (2), and having a carboxyl group when the total constituting structural units are 100 wt% Lower layer (resist layer I) of a two-layer laminated film obtained from a positive radiation-sensitive resin composition 1 containing a polymer having a unit of less than 1% by weight, (B) a quinonediazide group-containing compound and (C) a solvent When,
An upper layer (resist layer II) of a two-layer laminated film obtained from (D) a polymer having a phenolic hydroxyl group, (E) a quinonediazide group-containing compound and (F) a positive radiation-sensitive resin composition 2 containing a solvent. A two-layer laminated film characterized by being used.

(In the formula, R ₁ is a hydrogen atom or a methyl group, R ₂ is — (CH ₂ ) n—, n is an integer of 0 to 3, or — (C═O) —NH—, or (C═ O) —O—, R ₃ is an alkyl group having 1 to 4 carbon atoms, m is an integer of 0 to _4. R ₄ is a methylene group or an alkylene group having 2 to 10 carbon atoms, (It may have a ring structure.)   The two-layer laminated film according to claim 1, wherein the structural unit represented by the general formula (1) is a structural unit derived from 4-isopropenylphenol.   The two-layer laminated film according to claim 1 or 2, wherein the structural unit represented by the general formula (2) is a structural unit derived from hydroxyalkyl acrylate.   In the positive radiation sensitive 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 (F). The two-layer laminated film according to any one of claims 1 to 3.   In the positive radiation sensitive resin composition 2, the solvent (F) is a solvent containing at least one selected from 2-heptanone, 3-heptanone, 4-heptanone and cyclohexanone and / or dialkylene glycol dialkyl ether. The two-layer laminated film according to any one of claims 1 to 4, wherein:   The two-layer laminated film according to any one of claims 1 to 5, wherein the positive radiation sensitive resin composition 1 contains an organically modified polysiloxane as the surfactant (G). The lower layer (resist layer [I]) has a thickness of 0.1 μm to 3 μm, and the upper layer (resist layer [II]) has a thickness of 0.1 μm to 10 μm. The two-layer laminated film according to any one of claims 1 to 6.   The two-layer laminated film according to any one of claims 1 to 7, wherein the radical polymer (A) does not contain a structural unit having a carboxyl group. (A) The structural unit represented by the general formula (1) and the structural unit represented by the general formula (2) are included, and the structural unit having a carboxyl group when the total structural unit constituting the structural unit is 100% by weight. Lower layer (resist layer [I]) of a two-layer laminated film obtained from a positive radiation sensitive resin composition 1 containing a radical polymer of less than 1% by weight, (B) a quinonediazide group-containing compound and (C) a solvent. )When,
(D) Upper layer of a two-layer laminated film obtained from a positive radiation sensitive resin composition 2 containing a polymer having a phenolic hydroxyl group, (E) a quinonediazide group-containing compound and (F) a solvent (resist layer [II] ) Is used to form a two-layer laminated film. (A) After forming a lower layer from the positive radiation-sensitive resin composition 1 on the substrate surface, the upper layer (resist layer [1] from the positive radiation-sensitive resin composition 2 is formed on the lower layer (resist layer [I]). II]) to form a two-layer laminated film;
(B) pattern-exposing the laminated film by exposure with UV light and / or drawing with an electron beam;
(C) a step of developing the laminated film to form a resist pattern having a larger undercut shape in which the bottom of the laminated film removed portion by development is larger than the opening;
(D) a step of depositing and / or sputtering an organic thin film or an inorganic thin film on the surface of the laminated film that has undergone the resist pattern forming step (c) and the substrate surface at a position corresponding to the opening;
(E) The process of peeling the vapor deposition film and / or sputtered film which were deposited on the said laminated film with the said laminated film is provided, The pattern formation method of Claim 9 characterized by the above-mentioned.

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