JP2012230134A - Radiation-sensitive resin composition, interlayer insulating film for display element and formation method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation-sensitive resin composition having less film thickness variation of an unexposed part in addition to sufficient sensitivity; an interlayer insulating film for a display element formed from the radiation-sensitive resin composition; and a formation method thereof.SOLUTION: The present invention is a radiation-sensitive resin composition containing a polymer comprising a structural unit (I) having a group represented by the formula (1) and a structural unit (II) having an epoxy group, in [A] the same or different polymer molecules, where the content of the structural unit (I) is 10 mol% or more and 90 mol% or less. The film thickness variation rate of a film thickness Tafter developing to a film thickness Tbefore developing is effectively 90% or more.

Description

  The present invention relates to a radiation-sensitive resin composition, an interlayer insulating film for display elements, and a method for forming the same.

  The display element is generally provided with a display element interlayer insulating film for the purpose of insulating between wirings arranged in layers. As a material for forming an interlayer insulating film for display elements, there are a wide range of radiation-sensitive resin compositions because the number of steps for forming a pattern is small and the obtained interlayer insulating film for display elements requires high flatness. It is used. Such a radiation sensitive resin composition is required to have good sensitivity, and the interlayer insulating film for display elements is required to have excellent heat resistance in addition to the flatness.

  As such a radiation sensitive resin composition, an acrylic resin is widely adopted, and for example, a composition containing a crosslinking agent, an acid generator and an alkali-soluble resin is known (Japanese Patent Application Laid-Open No. 2004-4669). Issue gazette). The alkali-soluble resin has a protecting group (a group that is insoluble or hardly soluble in an alkaline aqueous solution and can be dissociated by the action of an acid). After the protective group is dissociated by exposure, the alkali aqueous resin is a developer. A resin that becomes soluble. As another radiation-sensitive resin composition, a radiation-sensitive resin composition containing an acetal structure and / or a ketal structure, a resin containing an epoxy group, and an acid generator has been proposed (Japanese Patent Application Laid-Open No. 2004-2004). 264623).

  Further, a positive radiation-sensitive resin composition containing a polymer having a bulky alicyclic hydrocarbon group via an acetal structure and / or a ketal structure has been proposed (see Japanese Patent Application Laid-Open No. 2007-127691). This positive-type radiation-sensitive resin composition is a resist material for semiconductors, and forms an organic film that is scheduled to be removed by etching after pattern formation. On the other hand, the interlayer insulating film for a display element is a so-called permanent film, and unlike the organic film, it is not scheduled to be removed by etching, and high reliability in the display element such as curing strength is required. .

  Furthermore, when an attempt is made to form an interlayer insulating film for a display element using such a conventional radiation-sensitive resin composition, the reduction in the film thickness of the unexposed area in the development process or post-bake process is large, and the There are disadvantages in that the flatness of the interlayer insulating film is impaired and a deviation from the designed film thickness occurs. Moreover, in order to avoid this inconvenience, it is necessary to strictly adjust the development time, which leads to inefficiency of the production process.

  In view of such a situation, development of a radiation-sensitive resin composition is desired in which, in addition to good sensitivity, there is little change in film thickness in the unexposed areas after the development process and post-baking process.

JP 2004-4669 A JP 2004-264623 A JP 2007-127691 A

  The present invention has been made based on the above circumstances, and in addition to good sensitivity, a radiation-sensitive resin composition having a small amount of change in film thickness at an unexposed portion, formed from this radiation-sensitive resin composition. It is an object to provide an interlayer insulating film for a display element and a method for forming the same.

（式（１）中、Ｒ^１及びＲ^２は、それぞれ独立して水素原子、アルキル基、シクロアルキル基又はアリール基である。但し、上記アルキル基、シクロアルキル基及びアリール基が有する水素原子の一部又は全部は、置換されていてもよい。また、Ｒ^１及びＲ^２が共に水素原子である場合はない。Ｒ^３は、単結合、メチレン基又はアルキレン基である。Ｒ^４は、炭素数４以上の脂環式炭化水素基、又は員数５〜８の複素環基である。但し、上記脂環式炭化水素基及び複素環基が有する水素原子の一部又は全部は、置換されていてもよい。） The invention made to solve the above problems is
[A] The content of the structural unit (I) including the structural unit (I) having a group represented by the following formula (1) and the structural unit (II) having an epoxy group in the same or different polymer molecules Of 10 mol% or more and 90 mol% or less (hereinafter also referred to as “[A] polymer”)
Is a radiation-sensitive resin composition.

(In formula (1), R ¹ and R ² are each independently a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group, provided that the hydrogen atom of the alkyl group, cycloalkyl group and aryl group is A part or all of them may be substituted, and R ¹ and R ² are not both hydrogen atoms, R ³ is a single bond, a methylene group or an alkylene group, R ⁴ is carbon It is an alicyclic hydrocarbon group having a number of 4 or more, or a heterocyclic group having 5 to 8. However, some or all of the hydrogen atoms of the alicyclic hydrocarbon group and the heterocyclic group are substituted. May be.)

The group represented by the above formula (1) of the structural unit (I) is present as a group (acid dissociable group) that dissociates in the presence of an acid to generate a polar group. The [A] polymer which was dissociated by the acid generated from the [B] acid generator described later, and thus was insoluble in alkali, becomes alkali-soluble. On the other hand, since the acid dissociable group has a relatively bulky protective group as R ⁴ , it is possible to suppress a decrease in the film thickness of the unexposed portion in the development process. In addition, the reduction in film thickness after post-baking can be suppressed, and an interlayer insulating film for a display element with high contact hole diameter stability can be formed. Further, the radiation sensitive resin composition has good sensitivity. On the other hand, when [A] polymer contains structural unit (II), the shape stability of the contact hole of the interlayer insulation film for display elements formed from the said radiation sensitive resin composition improves more.

Thickness change rate of the thickness T ₁ of the after development with respect to the film thickness T ₀ of the coating film before development is preferably 90% or more. As described above, according to the forming method using the radiation-sensitive resin composition, the amount of change in the film thickness of the unexposed portion with respect to the development time can be suppressed, and the film thickness after development is 90% of the film thickness before development. % Or more can be maintained. The film thickness T ₀ is a _{value obtained} when a radiation sensitive resin composition is applied on a substrate and then pre-baked on a hot plate at 90 ° C. for 2 minutes to form a coating film having a film thickness of 4.1 μm. Refers to the film thickness. The film thickness T ₁ refers to the film thickness after the formed coating film has been developed for 90 seconds with a 0.5% tetramethylammonium hydroxide aqueous solution.

  The content of the structural unit (I) is preferably 20 mol% or more and 50 mol% or less. By making the content rate of structural unit (I) into the said specific range, a film thickness reduction amount can be suppressed more.

  The radiation-sensitive resin composition preferably further contains a [B] radiation-sensitive acid generator (hereinafter also referred to as “[B] acid generator”). When the radiation-sensitive resin composition further contains a [B] acid generator, the radiation-sensitive resin composition can exhibit positive radiation-sensitive characteristics and has good sensitivity. Can do.

R ⁴ in the above formula (1) is preferably a polycyclic alicyclic hydrocarbon group having 7 or more carbon atoms or a heterocyclic group having 5 to 8 carbon atoms, and a polycyclic alicyclic group having 7 or more carbon atoms. It is more preferable that it is a formula hydrocarbon group. By selecting a bulky protective group having the specific structure as R ⁴ , the amount of decrease in the film thickness of the unexposed portion can be particularly suppressed.

  The radiation-sensitive resin composition preferably further contains a [C] sensitizer. The sensitivity of the said radiation sensitive resin composition can be improved more because the said radiation sensitive resin composition further contains a [C] sensitizer.

  The said radiation sensitive resin composition is suitable as a forming material of the interlayer insulation film for display elements. Moreover, the interlayer insulation film for display elements formed from the said radiation sensitive resin composition is also suitably contained in this invention.

The method for forming an interlayer insulating film for a display element according to the present invention includes:
(1) The process of forming the coating film of the said radiation sensitive resin composition on a board | substrate,
(2) A step of irradiating at least a part of the coating film with radiation,
(3) a step of developing the coating film irradiated with the radiation; and (4) a step of heating the developed coating film.

  According to the formation method, an interlayer insulating film for a display element having high contact hole diameter stability can be formed. Further, since the amount of change in the film thickness of the unexposed portion can be suppressed, the production process margin can be improved as a result, and the yield can be improved. Furthermore, an interlayer insulating film for a display element having a fine and elaborate pattern can be easily formed by forming a pattern by exposure, development and heating utilizing photosensitivity. Therefore, the formed interlayer insulation film for display elements can be used suitably for display elements, such as a liquid crystal display element and an organic EL display element.

  As described above, the radiation-sensitive resin composition of the present invention provides a radiation-sensitive resin composition having a small amount of change in the thickness of an unexposed portion after the development process and post-baking process in addition to good sensitivity. can do. In addition, the stability of the contact hole diameter can be improved. Since the amount of change in film thickness can be reduced, the production process margin can be improved as a result, and the yield can be improved. Furthermore, an interlayer insulating film for a display element having a fine and elaborate pattern can be easily formed by forming a pattern by exposure, development and heating utilizing photosensitivity. Therefore, the formed interlayer insulation film for display elements can be used suitably for display elements, such as a liquid crystal display element and an organic EL display element.

<Radiation sensitive resin composition>
The radiation sensitive resin composition of this invention contains a [A] polymer. Moreover, the said radiation sensitive resin composition may contain a [B] acid generator and a [C] sensitizer as a suitable component. Furthermore, the radiation-sensitive resin composition may contain other optional components as long as the effects of the present invention are not impaired. Hereinafter, each component will be described in detail.

<[A] polymer>
[A] The polymer contains structural units (I) having a group represented by the above formula (1) and structural units (II) having an epoxy group in the same or different polymer molecules, and the structural unit (I ) Is 10 mol% or more and 90 mol% or less. [A] The polymer may contain other structural units as long as the effects of the present invention are not impaired. In addition, the [A] polymer may contain 2 or more types of each structural unit. Hereinafter, each structural unit will be described in detail.

[Structural unit (I)]
The structural unit (I) has a group represented by the above formula (1). In said formula (1), R < ¹ > and R < ² > are respectively independently a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group. However, one part or all part of the hydrogen atom which the said alkyl group, a cycloalkyl group, and an aryl group have may be substituted. Further, there is no case where R ¹ and R ² are both hydrogen atoms. R ³ is a single bond, a methylene group or an alkylene group. R ⁴ is an alicyclic hydrocarbon group having 4 or more carbon atoms, or a heterocyclic group having 5 to 8 members. However, one part or all part of the hydrogen atom which the said alicyclic hydrocarbon group and heterocyclic group have may be substituted.

Examples of the alkyl group represented by R ¹ and R ² include linear and branched alkyl groups having 1 to 30 carbon atoms. Examples of the linear and branched alkyl group having 1 to 30 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, and an n-octyl group. , N-dodecyl group, n-tetradecyl group, n-octadecyl group and other linear alkyl groups, i-propyl group, i-butyl group, t-butyl group, neopentyl group, 2-hexyl group, 3-hexyl group And a branched alkyl group such as.

Examples of the cycloalkyl group represented by R ¹ and R ² include a cycloalkyl group having 3 to 20 carbon atoms. Moreover, this C3-C20 cycloalkyl group may be polycyclic. Examples of the cycloalkyl group having 3 to 20 carbon atoms include cyclopropyl group, cyclopentyl group, cyclohexyl group, cycloheptyl, cyclooctyl, bornyl group, norbornyl group, adamantyl group and the like.

Examples of the aryl group represented by R ¹ and R ² include an aryl group having 6 to 14 carbon atoms. The aryl group having 6 to 14 carbon atoms may be a single ring, a structure in which single rings are connected, or a condensed ring. Examples of the aryl group having 6 to 14 carbon atoms include a phenyl group and a naphthyl group.

Examples of the optionally substituted alkyl group, cycloalkyl group and aryl group represented by R ¹ and R ² include a halogen atom, a hydroxyl group, a nitro group, a cyano group, a carboxyl group, a carbonyl group, a cyclo group. An alkyl group (eg, cyclopropyl group, cyclopentyl group, cyclohexyl group, cycloheptyl, cyclooctyl, bornyl group, norbornyl group, adamantyl group, etc.), aryl group (eg, phenyl group, naphthyl group, etc.), alkoxy group (eg, methoxy group) , An ethoxy group, a propoxy group, an n-butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group and the like, and an acyl group (for example, an acetyl group and a propionyl group). , Butyryl group, i-butyryl group and the like having 2 to 20 carbon atoms A siloxy group), an acyloxy group (for example, an acetoxy group, an ethylyloxy group, a butyryloxy group, a t-butyryloxy group, a t-amylyloxy group, etc., an acyloxy group having 2 to 10 carbon atoms), an alkoxycarbonyl group (for example, a methoxycarbonyl group) C2-C20 alkoxycarbonyl groups such as ethoxycarbonyl group and propoxycarbonyl group), haloalkyl groups (for example, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group) , N-octyl group, n-dodecyl group, n-tetradecyl group, n-octadecyl group and the like linear alkyl group, i-propyl group, i-butyl group, t-butyl group, neopentyl group, 2-hexyl group Alkyl groups such as branched alkyl groups such as 3-hexyl group; cyclopropyl group, cyclobutyl group, Examples include a group in which part or all of hydrogen atoms of a cycloalkyl group such as a cyclopentyl group, a norbornyl group, and an adamantyl group are substituted with a halogen atom), a hydroxyalkyl group (for example, a hydroxymethyl group).

Examples of the alkylene group represented by R ³ include an ethylene group, a propylene group, and a butylene group.

The alicyclic hydrocarbon group having 4 or more carbon atoms represented by R ⁴ is a monocyclic or polycyclic alicyclic group, such as a cycloheptyl group, a cyclooctyl group, a bornyl group, a norbornyl group, And an adamantyl group. Examples of the heterocyclic group having 5 to 8 members represented by R ⁴ include a tetrahydrofuranyl group, a tetrahydropyranyl group, a pyrrolidinyl group, a piperidinyl group, a tetrahydrothienyl group, and a tetrahydrothianyl group.

As the substituent of the group represented by R ⁴ , for example, the groups exemplified as the substituent of the optionally substituted alkyl group, cycloalkyl group and aryl group represented by R ¹ and R ² can be applied. .

R ⁴ is preferably a polycyclic alicyclic hydrocarbon group having 7 or more carbon atoms or a heterocyclic group having 5 to 8 carbon atoms, and is a polycyclic alicyclic hydrocarbon group having 7 or more carbon atoms. More preferably. By selecting the specific bulky protecting group as R ⁴ , it is possible to further suppress the film thickness reduction amount of the unexposed portion.

  As group represented by the said Formula (1), group represented by a following formula is preferable.

  Examples of the monomer that gives the structural unit (I) include 1- (norbornyloxy) ethyl methacrylate, 1- (tricyclodecanyloxy) ethyl methacrylate, and 1- (pentacyclopentadecanylmethyl methacrylate). Oxy) ethyl, 1- (pentacyclopentadecanyloxy) ethyl methacrylate, 1- (hydroxymethyltricyclodecanyloxy) ethyl methacrylate, 1- (tetracyclododecanylmethyloxy) ethyl methacrylate, methacrylic acid 1 -(Adamantyloxy) ethyl, 1- (tetrahydrofuranylmethyloxy) ethyl methacrylate, 1- (tetrahydropyranylmethyloxy) ethyl methacrylate, 1- (tetrahydrofuranyloxy) ethyl methacrylate, 1- (tetrahydropyrani methacrylate) Luoxy) Le, methacrylic acid 1- (tetrahydrothienyl methyloxy) ethyl, methacrylate 1- (thia sulfonyl methyloxy) ethyl, and the like. These monomers can be used alone or in combination of two or more.

  [A] The content of the structural unit (I) in the polymer is 10 mol% or more and 90 mol% or less, and 20 mol% or more and 50 mol% or less with respect to all the structural units in the [A] polymer. preferable. By making the content rate of structural unit (I) into the said specific range, a film thickness reduction amount can be suppressed more.

[Structural unit (II)]
[A] The polymer further includes a structural unit (II) having an epoxy group in a polymer molecule containing the structural unit (I) or in another polymer molecule not containing the structural unit (I). By further including the structural unit (II), the shape stability of the contact hole of the interlayer insulating film for display elements formed from the radiation-sensitive resin composition is further improved. The structural unit (II) is not particularly limited as long as it is a structural unit derived from an epoxy group-containing monomer. In addition, the epoxy group of this specification is a concept including an oxiranyl group (1,2-epoxy structure) and an oxetanyl group (1,3-epoxy structure).

As an embodiment of the [A] polymer containing the structural unit (I) and the structural unit (II), for example, (i) including both the structural unit (I) and the structural unit (II) in the same polymer molecule [A] when one polymer molecule is present in the polymer;
(Ii) In the case where the structural unit (I) is contained in one polymer molecule and the structural unit (II) is contained in a different polymer molecule, and [A] two polymer molecules are present in the polymer. ;
(Iii) A polymer molecule containing both the structural unit (I) and the structural unit (II) in one polymer molecule and a structural unit (I) in a polymer molecule different from the structural unit (I). In the case of containing the structural unit (II), and [A] three kinds of polymer molecules are present in the polymer;
(Iv) In addition to the polymer molecules of (i) to (iii) above, there may be mentioned a case where [A] the polymer further contains one or more polymer molecules.

Examples of the epoxy group-containing monomer that gives an epoxy group-containing structural unit include glycidyl (meth) acrylate, 3,4-epoxybutyl (meth) acrylate, 3-methyl-3,4-epoxybutyl acrylate, and methacrylic acid. 3-ethyl-3,4-epoxybutyl acid, 5,6-epoxyhexyl (meth) acrylate, 5-methyl-5,6-epoxyhexyl methacrylate, 5-ethyl-5,6-epoxyhexyl methacrylate, (Meth) acrylic acid 6,7-epoxyheptyl, 3,4-epoxycyclohexyl methacrylate, 3,4-epoxycyclohexylmethyl methacrylate, 3,4-epoxycyclohexylethyl (meth) acrylate, methacrylic acid 3,4-epoxycyclohexylpropyl, 3,4-epoxycyclohexyl methacrylate Chill, 3,4-epoxycyclohexylhexyl (meth) acrylate, 3,4-epoxycyclohexylmethyl acrylate, 3,4-epoxycyclohexylethyl acrylate, 3,4-epoxycyclohexylpropyl acrylate Oxiranyl group-containing (meth) acrylic compounds such as 3,4-epoxycyclohexylbutyl acrylate, 3,4-epoxycyclohexylhexyl acrylate;
o-vinyl benzyl glycidyl ether, m-vinyl benzyl glycidyl ether, p-vinyl benzyl glycidyl ether, α-methyl-o-vinyl benzyl glycidyl ether, α-methyl-m-vinyl benzyl glycidyl ether, α-methyl-p-vinyl Vinyl benzyl glycidyl ethers such as benzyl glycidyl ether;
vinyl phenyl glycidyl ethers such as o-vinyl phenyl glycidyl ether, m-vinyl phenyl glycidyl ether, p-vinyl phenyl glycidyl ether;
3-acryloyloxymethyloxetane, 3-acryloyloxymethyl-3-methyloxetane, 3-acryloyloxymethyl-3-ethyloxetane, 3-acryloyloxymethyl-3-phenyloxetane, 3- (2-acryloyloxyethyl) oxetane 3- (2-acryloyloxyethyl) -3-ethyloxetane, 3- (2-acryloyloxyethyl) -3-ethyloxetane, 3- (2-acryloyloxyethyl) -3-phenyloxetane, 3-methacryloyloxy Methyl oxetane, 3-methacryloyloxymethyl-3-methyloxetane, 3-methacryloyloxymethyl-3-ethyloxetane, 3-methacryloyloxymethyl-3-phenyloxetane, 3- (2-methacryloyloxye) Oxetane, 3- (2-methacryloyloxyethyl) -3-ethyloxetane, 3- (2-methacryloyloxyethyl) -3-ethyloxetane, 3- (2-methacryloyloxyethyl) -3-phenyloxetane, 2 -Acryloyloxymethyloxetane, 2-acryloyloxymethyl-2-methyloxetane, 2-acryloyloxymethyl-2-ethyloxetane, 2-acryloyloxymethyl-2-phenyloxetane, 2- (2-acryloyloxyethyl) oxetane, 2- (2-acryloyloxyethyl) -2-ethyloxetane, 2- (2-acryloyloxyethyl) -2-ethyloxetane, 2- (2-acryloyloxyethyl) -2-phenyloxetane, 2-methacryloyloxymethyl Oh Cetane, 2-methacryloyloxymethyl-2-methyloxetane, 2-methacryloyloxymethyl-2-ethyloxetane, 2-methacryloyloxymethyl-2-phenyloxetane, 2- (2-methacryloyloxyethyl) oxetane, 2- (2 -Methacryloyloxyethyl) -2-ethyloxetane, 2- (2-methacryloyloxyethyl) -2-ethyloxetane, 2- (2-methacryloyloxyethyl) -2-phenyloxetane, and other oxetanyl group-containing (meth) acrylic compounds Compounds and the like.

  Among the above epoxy group-containing monomers, glycidyl methacrylate, 2-methylglycidyl methacrylate, 3,4-epoxycyclohexyl methacrylate, 3,4-epoxycyclohexylmethyl methacrylate, 3-methacryloyloxymethyl-3-methyloxetane 3-methacryloyloxymethyl-3-ethyloxetane is preferable from the viewpoint of copolymerization reactivity with other monomers and developability of the radiation-sensitive resin composition.

  [A] The content of the structural unit (II) in the polymer is such that when the structural unit (I) and the structural unit (II) are contained in the same polymer molecule, [A] all structural units in the polymer 1 mol% to 60 mol% is preferable, and 5 mol% to 50 mol% is more preferable.

  On the other hand, when one polymer molecule contains the structural unit (I) and another polymer molecule contains the structural unit (II), the structural unit contained in the polymer molecule containing the structural unit (II) ( The content of II) is preferably 20% by mass to 100% by mass, and preferably 30% by mass to 70% by mass with respect to all structural units in the polymer molecule containing the structural unit (II). Is more preferable.

[Other structural units]
[A] The polymer may contain other structural units other than the structural unit (I) and the structural unit (II) as long as the effects of the present invention are not impaired. Examples of the monomer that gives other structural units include a monomer having a carboxyl group or a derivative thereof, a monomer having a hydroxyl group, and other monomers.

  Examples of the monomer having a carboxyl group or a derivative thereof include acrylic acid, methacrylic acid, crotonic acid, 2-acryloyloxyethyl succinic acid, 2-methacryloyloxyethyl succinic acid, 2-acryloyloxyethyl hexahydrophthalic acid, Examples thereof include monocarboxylic acids such as 2-methacryloyloxyethyl hexahydrophthalic acid; dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid, mesaconic acid, and itaconic acid; and acid anhydrides of the above dicarboxylic acids. Of these monomers having a carboxyl group or a derivative thereof, methacrylic acid is preferred.

  Examples of the monomer having a hydroxyl group include hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 4-hydroxymethylcyclohexylmethyl acrylate; methacrylic acid 2 -Hydroxyethyl, 3-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, 5-hydroxypentyl methacrylate, 6-hydroxyhexyl methacrylate, 4-hydroxymethyl methacrylate-hydroxyalkyl methacrylate and the like. It is done. Of these monomers having a hydroxyl group, 2-hydroxyethyl acrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, and methacrylic acid 2 are used from the viewpoint of heat resistance of the obtained interlayer insulating film for display elements. -Hydroxyethyl, 4-hydroxybutyl methacrylate, 4-hydroxymethyl-cyclohexylmethyl acrylate, 4-hydroxymethyl-cyclohexylmethyl methacrylate are preferred.

Examples of other monomers include alkyl acrylates such as methyl acrylate and i-propyl acrylate;
Alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, t-butyl methacrylate;
Alkoxyalkyl methacrylates such as 1-n-butoxyethyl methacrylate;
Cyclohexyl acrylate, 2-methylcyclohexyl acrylate, tricyclo [5.2.1.0 ^2,6 ] decan-8-yl acrylate, 2- (tricyclo [5.2.1.0 ^2,6 ] acrylate Decyl-8-yloxy) ethyl, cycloaliphatic alkyl acrylates such as isobornyl acrylate;
Cyclohexyl methacrylate, 2-methylcyclohexyl methacrylate, tricyclo [5.2.1.0 ^2,6 ] decane-8-yl methacrylate, 2- (tricyclo [5.2.1.0 ^2,6 ] methacrylate) Decane-8-yloxy) ethyl, cycloaliphatic alkyl methacrylates such as isobornyl methacrylate;
Aryl esters of acrylic acid such as phenyl acrylate and benzyl acrylate or aralkyl of acrylic acid;
Aryl esters of methacrylic acid such as phenyl methacrylate and benzyl methacrylate or aralkyl of methacrylic acid;
Dialkyl dicarboxylates such as diethyl maleate, diethyl fumarate, diethyl itaconate;
Unsaturated hetero 5-membered methacrylic acid ester or unsaturated hetero 6 containing 1 atom of oxygen such as tetrahydrofurfuryl methacrylate, tetrahydrofuryl methacrylate, 2-tetrahydropyranyl methacrylate, 2-tetrahydropyran-2-methyl methacrylate, etc. Membered ring methacrylic acid;
4-methacryloyloxymethyl-2-methyl-2-ethyl-1,3-dioxolane, 4-methacryloyloxymethyl-2-methyl-2-isobutyl-1,3-dioxolane, 4-methacryloyloxymethyl-2-cyclohexyl- 2 oxygen atoms such as 1,3-dioxolane, 4-methacryloyloxymethyl-2-methyl-2-ethyl-1,3-dioxolane, 4-methacryloyloxymethyl-2-methyl-2-isobutyl-1,3-dioxolane An unsaturated heterocyclic 5-membered methacrylic acid containing:
4-acryloyloxymethyl-2,2-dimethyl-1,3-dioxolane, 4-acryloyloxymethyl-2-methyl-2-ethyl-1,3-dioxolane, 4-acryloyloxymethyl-2, 2-diethyl- 1,3-dioxolane, 4-acryloyloxymethyl-2-methyl-2-isobutyl-1,3-dioxolane, 4-acryloyloxymethyl-2-cyclopentyl-1,3-dioxolane, 4-acryloyloxymethyl-2- Cyclohexyl-1,3-dioxolane, 4-acryloyloxyethyl-2-methyl-2-ethyl-1,3-dioxolane, 4-acryloyloxypropyl-2-methyl-2-ethyl-1,3-dioxolane, 4- Acryloyloxybutyl-2-methyl-2-ethyl-1,3-dioxola Unsaturated five-membered heterocyclic acrylic acid containing oxygen 2 atoms and the like;
Vinyl aromatic compounds such as styrene, α-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, 4-isopropenylphenol;
N-phenylmaleimide, N-cyclohexylmaleimide, N-benzylmaleimide, N-succinimidyl-3-maleimidobenzoate, N-succinimidyl-4-maleimidobutyrate, N-succinimidyl-6-maleimidocaproate, N-succinimidyl-3 -N-substituted maleimides such as maleimide propionate, N- (9-acridinyl) maleimide;
Conjugated diene compounds such as 1,3-butadiene, isoprene and 2,3-dimethyl-1,3-butadiene;
And unsaturated compounds such as acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, vinyl chloride, vinylidene chloride and vinyl acetate.

Among these other monomers, styrene, 1-n-butoxyethyl methacrylate, 4-isopropenylphenol, tricyclo [5.2.1.0 ^2,6 ] decan-8-yl methacrylate, methacrylic acid Tetrahydrofurfuryl, 2-tetrahydropyranyl methacrylate, 1,3-butadiene, 4-acryloyloxymethyl-2-methyl-2-ethyl-1,3-dioxolane, N-cyclohexylmaleimide, N-phenylmaleimide, methacrylic acid Benzyl is preferable from the viewpoints of copolymerization reactivity with the monomer having the carboxyl group or derivative thereof, and the monomer having a hydroxyl group and the developability of the radiation-sensitive resin composition.

[A] Polystyrene conversion weight average molecular weight (Mw) by gel permeation chromatography (GPC) of the polymer is preferably 2.0 × 10 ^{3 to} 1.0 × 10 ⁵ , more preferably 5.0 × 10. ^{3 to} 5.0 × 10 ⁴ . [A] By making Mw of a polymer into the above-mentioned specific range, the sensitivity and alkali developability of the radiation sensitive resin composition can be improved.

[A] The number average molecular weight (Mn) in terms of polystyrene by GPC of the polymer is preferably 2.0 × 10 ^{3 to} 1.0 × 10 ⁵ , more preferably 5.0 × 10 ^{3 to} 5.0 × 10. ⁴ . [A] By making Mn of a polymer into the said specific range, the curing reactivity at the time of hardening of the coating film of the said radiation sensitive resin composition can be improved.

  [A] The molecular weight distribution (Mw / Mn) of the polymer is preferably 3.0 or less, more preferably 2.6 or less. [A] By setting Mw / Mn of the polymer to 3.0 or less, the developability of the obtained interlayer insulating film for display elements can be enhanced.

In addition, Mw and Mn of this specification were measured by GPC under the following conditions.
Apparatus: GPC-101 (made by Showa Denko)
Column: GPC-KF-801, GPC-KF-802, GPC-KF-803 and GPC-KF-804 are combined Mobile phase: Tetrahydrofuran Column temperature: 40 ° C
Flow rate: 1.0 mL / min Sample concentration: 1.0% by mass
Sample injection volume: 100 μL
Detector: Differential refractometer Standard material: Monodisperse polystyrene

<[A] Polymer Synthesis Method>
[A] The polymer can be synthesized by radical copolymerization of monomers giving the above structural units. For example, when synthesizing a polymer [A] containing both the structural unit (I) and the structural unit (II) in the same polymer molecule, the monomer that gives the structural unit (I) and the structural unit (II) What is necessary is just to copolymerize using the mixture containing the monomer which gives. On the other hand, when the [A] polymer having the structural unit (I) in one polymer molecule and the structural unit (II) in a different polymer molecule is synthesized, the structural unit (I) is given. A polymer solution containing a monomer is radically polymerized to obtain a polymer molecule having the structural unit (I), and a polymer solution containing a monomer that gives the structural unit (II) is separately radically polymerized to form a structure. What is necessary is just to obtain the polymer molecule | numerator which has a unit (II), and finally mix both to make a [A] polymer.

  [A] Examples of the solvent used in the polymerization reaction of the polymer include the solvents exemplified in the section of preparation of the radiation-sensitive resin composition described later.

  As the polymerization initiator used in the polymerization reaction, those generally known as radical polymerization initiators can be used. For example, 2,2′-azobisisobutyronitrile, 2,2′-azobis- ( 2,4-Dimethylvaleronitrile), 2,2′-azobis- (4-methoxy-2,4-dimethylvaleronitrile), azo compounds such as 2,2′-azobis (methyl 2-methylpropionate); benzoyl Organic peroxides such as peroxide, lauroyl peroxide, t-butylperoxypivalate, 1,1′-bis- (t-butylperoxy) cyclohexane; hydrogen peroxide and the like.

  [A] In the polymerization reaction of the polymer, a molecular weight modifier may be used to adjust the molecular weight. Examples of the molecular weight modifier include halogenated hydrocarbons such as chloroform and carbon tetrabromide; mercaptans such as n-hexyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, and thioglycolic acid; Xanthogens such as xanthogen sulfide and diisopropylxanthogen disulfide; terpinolene, α-methylstyrene dimer and the like.

<[B] Acid generator>
[B] The acid generator is a compound that generates an acid upon irradiation with radiation. As the radiation, for example, visible light, ultraviolet light, far ultraviolet light, electron beam, X-ray or the like can be used. When the radiation sensitive resin composition contains the [B] acid generator, the radiation sensitive resin composition can exhibit positive radiation sensitive characteristics and can have good sensitivity. [B] The inclusion form of the acid generator in the radiation-sensitive resin composition may be an acid generator (hereinafter, also referred to as “[B] acid generator” as appropriate), which is a compound as described below, [ A] It may be in the form of an acid generating group incorporated as part of a polymer or other polymer, or both forms.

  [B] Examples of the acid generator include oxime sulfonate compounds, onium salts, sulfonimide compounds, halogen-containing compounds, diazomethane compounds, sulfone compounds, sulfonic acid ester compounds, and carboxylic acid ester compounds. In addition, each of these [B] acid generators can be used individually or in combination of 2 or more types.

[Oxime sulfonate compound]
Examples of the oxime sulfonate compound include a compound containing an oxime sulfonate group represented by the following formula (2).

In the above formula (2), R ^B1 is a linear or branched alkyl group, cycloalkyl group, or aryl group. However, in these groups, some or all of the hydrogen atoms may be substituted.

The linear or branched alkyl group represented by R ^B1 is preferably a linear or branched alkyl group having 1 to 10 carbon atoms. The linear or branched alkyl group having 1 to 10 carbon atoms may be substituted. Examples of the substituent include an alkoxy group having 1 to 10 carbon atoms and 7,7-dimethyl-2-oxonorbornyl. And an alicyclic group containing a bridged alicyclic group such as a group. A preferred alicyclic group is a bicycloalkyl group. The aryl group represented by R ^B1 is preferably an aryl group having 6 to 11 carbon atoms, and more preferably a phenyl group or a naphthyl group. The aryl group may be substituted, and examples of the substituent include an alkyl group having 1 to 5 carbon atoms, an alkoxy group, and a halogen atom.

  Examples of the compound containing an oxime sulfonate group represented by the above formula (2) include an oxime sulfonate compound represented by the following formula (3).

In the above formula (3), R ^B1 has the same ^{meaning as} in the above formula (2). X is an alkyl group, an alkoxy group, or a halogen atom. m is an integer of 0-3. However, when there are a plurality of Xs, the plurality of Xs may be the same or different.

  The alkyl group that can be represented by X is preferably a linear or branched alkyl group having 1 to 4 carbon atoms. The alkoxy group represented by X is preferably a linear or branched alkoxy group having 1 to 4 carbon atoms. The halogen atom represented by X is preferably a chlorine atom or a fluorine atom. As m, 0 or 1 is preferable. In the above formula (3), a compound in which m is 1, X is a methyl group, and the substitution position of X is ortho is preferable.

  Examples of the oxime sulfonate compound represented by the above (3) include compounds represented by the following formulas (3-1) to (3-5).

  The compounds (3-1) to (3-5) are respectively represented by (5-propylsulfonyloxyimino-5H-thiophen-2-ylidene)-(2-methylphenyl) acetonitrile, (5-octylsulfonyloxyimino-5H). -Thiophen-2-ylidene)-(2-methylphenyl) acetonitrile, (camphorsulfonyloxyimino-5H-thiophen-2-ylidene)-(2-methylphenyl) acetonitrile, (5-p-toluenesulfonyloxyimino-5H -Thiophen-2-ylidene)-(2-methylphenyl) acetonitrile and (5-octylsulfonyloxyimino)-(4-methoxyphenyl) acetonitrile, which are commercially available.

[Onium salt]
Examples of the onium salt include diphenyliodonium salt, triphenylsulfonium salt, sulfonium salt, benzothiazonium salt, and tetrahydrothiophenium salt.

  Examples of the diphenyliodonium salt include diphenyliodonium tetrafluoroborate, diphenyliodonium hexafluorophosphonate, diphenyliodonium hexafluoroarsenate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium trifluoroacetate, diphenyliodonium-p-toluenesulfonate, diphenyliodonium Butyltris (2,6-difluorophenyl) borate, 4-methoxyphenylphenyliodonium tetrafluoroborate, bis (4-t-butylphenyl) iodonium tetrafluoroborate, bis (4-t-butylphenyl) iodonium hexafluoroarsenate Bis (4-t-butylphenyl) iodonium trifluorome Sulphonate, bis (4-t-butylphenyl) iodonium trifluoroacetate, bis (4-t-butylphenyl) iodonium-p-toluenesulfonate, bis (4-t-butylphenyl) iodonium camphorsulfonic acid, etc. .

  Examples of the triphenylsulfonium salt include triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium camphorsulfonic acid, triphenylsulfonium tetrafluoroborate, triphenylsulfonium trifluoroacetate, triphenylsulfonium-p-toluenesulfonate, triphenylsulfonium. And butyl tris (2,6-difluorophenyl) borate.

  Examples of the sulfonium salt include alkylsulfonium salts, benzylsulfonium salts, dibenzylsulfonium salts, substituted benzylsulfonium salts and the like.

  Examples of the alkylsulfonium salt include 4-acetoxyphenyldimethylsulfonium hexafluoroantimonate, 4-acetoxyphenyldimethylsulfonium hexafluoroarsenate, dimethyl-4- (benzyloxycarbonyloxy) phenylsulfonium hexafluoroantimonate, dimethyl-4- (Benzoyloxy) phenylsulfonium hexafluoroantimonate, dimethyl-4- (benzoyloxy) phenylsulfonium hexafluoroarsenate, dimethyl-3-chloro-4-acetoxyphenylsulfonium hexafluoroantimonate and the like can be mentioned.

  Examples of the benzylsulfonium salt include benzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, benzyl-4-hydroxyphenylmethylsulfonium hexafluorophosphate, 4-acetoxyphenylbenzylmethylsulfonium hexafluoroantimonate, benzyl-4-methoxyphenyl. Methylsulfonium hexafluoroantimonate, benzyl-2-methyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, benzyl-3-chloro-4-hydroxyphenylmethylsulfonium hexafluoroarsenate, 4-methoxybenzyl-4-hydroxyphenyl Examples include methylsulfonium hexafluorophosphate.

  Examples of the dibenzylsulfonium salt include dibenzyl-4-hydroxyphenylsulfonium hexafluoroantimonate, dibenzyl-4-hydroxyphenylsulfonium hexafluorophosphate, 4-acetoxyphenyl dibenzylsulfonium hexafluoroantimonate, and dibenzyl-4-methoxyphenylsulfonium. Hexafluoroantimonate, dibenzyl-3-chloro-4-hydroxyphenylsulfonium hexafluoroarsenate, dibenzyl-3-methyl-4-hydroxy-5-t-butylphenylsulfonium hexafluoroantimonate, benzyl-4-methoxybenzyl- Examples include 4-hydroxyphenylsulfonium hexafluorophosphate.

  Examples of substituted benzylsulfonium salts include p-chlorobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, p-nitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, and p-chlorobenzyl-4-hydroxyphenylmethyl. Sulfonium hexafluorophosphate, p-nitrobenzyl-3-methyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, 3,5-dichlorobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, o-chlorobenzyl-3- Examples include chloro-4-hydroxyphenylmethylsulfonium hexafluoroantimonate.

  Examples of the benzothiazonium salt include 3-benzylbenzothiazonium hexafluoroantimonate, 3-benzylbenzothiazonium hexafluorophosphate, 3-benzylbenzothiazonium tetrafluoroborate, and 3- (p-methoxybenzyl). ) Benzothiazonium hexafluoroantimonate, 3-benzyl-2-methylthiobenzothiazonium hexafluoroantimonate, 3-benzyl-5-chlorobenzothiazonium hexafluoroantimonate, and the like.

  Examples of tetrahydrothiophenium salts include 4,7-di-n-butoxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate and 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethane. Sulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium-1,1 , 2,2-Tetrafluoro-2- (norbornan-2-yl) ethanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium-2- (5-t-butoxycarbonyloxybicyclo) [2.2.1] Heptan-2-yl) -1,1, , 2-tetrafluoroethanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium-2- (6-t-butoxycarbonyloxybicyclo [2.2.1] heptan-2-yl ) -1,1,2,2-tetrafluoroethanesulfonate and the like.

[Sulfonimide compound]
Examples of the sulfonimide compound include N- (trifluoromethylsulfonyloxy) succinimide, N- (camphorsulfonyloxy) succinimide, N- (4-methylphenylsulfonyloxy) succinimide, N- (2-trifluoromethylphenylsulfonyloxy). ) Succinimide, N- (4-fluorophenylsulfonyloxy) succinimide, N- (trifluoromethylsulfonyloxy) phthalimide, N- (camphorsulfonyloxy) phthalimide, N- (2-trifluoromethylphenylsulfonyloxy) phthalimide, N -(2-fluorophenylsulfonyloxy) phthalimide, N- (trifluoromethylsulfonyloxy) diphenylmaleimide, N- (camphorsulfonyloxy) diphenyl monomer Imido, 4-methylphenylsulfonyloxy) diphenylmaleimide, N- (2-trifluoromethylphenylsulfonyloxy) diphenylmaleimide, N- (4-fluorophenylsulfonyloxy) diphenylmaleimide, N- (4-fluorophenylsulfonyloxy) Diphenylmaleimide, N- (phenylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboxylimide, N- (4-methylphenylsulfonyloxy) bicyclo [2.2.1] Hept-5-ene-2,3-dicarboxylimide, N- (trifluoromethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboxylimide, N- (nonafluorobutane Sulfonyloxy) bicyclo [2.2.1] Pto-5-ene-2,3-dicarboxylimide, N- (camphorsulfonyloxy) bicyclo [2.2.1] hept-5-en-2,3-dicarboxylimide, N- (camphorsulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboxylimide, N- (trifluoromethylsulfonyloxy) -7-oxabicyclo [2.2.1] hept-5 -Ene-2,3-dicarboxylimide, N- (4-methylphenylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboxylimide, N- (4-methylphenyl) Sulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboxylimide, N- (2-trifluoromethylphenylsulfonyl) Ruoxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboxylimide, N- (2-trifluoromethylphenylsulfonyloxy) -7-oxabicyclo [2.2.1] hept- 5-ene-2,3-dicarboxylimide, N- (4-fluorophenylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboxylimide, N- (4-fluoro Phenylsulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (trifluoromethylsulfonyloxy) bicyclo [2.2.1] heptane-5 , 6-oxy-2,3-dicarboxylimide, N- (camphorsulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3-di Ruboxylimide, N- (4-methylphenylsulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboxylimide, N- (2-trifluoromethylphenylsulfonyloxy) bicyclo [2.2.1] Heptane-5,6-oxy-2,3-dicarboxylimide, N- (4-fluorophenylsulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2 , 3-dicarboxylimide, N- (trifluoromethylsulfonyloxy) naphthyl dicarboxylimide, N- (camphorsulfonyloxy) naphthyl dicarboxylimide, N- (4-methylphenylsulfonyloxy) naphthyl dicarboxylimide, N- (Phenylsulfonyloxy) naphthyl dicarboxylimide, N- 2-trifluoromethylphenylsulfonyloxy) naphthyl dicarboxylimide, N- (4-fluorophenylsulfonyloxy) naphthyl dicarboxylimide, N- (pentafluoroethylsulfonyloxy) naphthyl dicarboxylimide, N- (heptafluoropropylsulfonyl) Oxy) naphthyl dicarboxylimide, N- (nonafluorobutylsulfonyloxy) naphthyl dicarboxylimide, N- (ethylsulfonyloxy) naphthyl dicarboxylimide, N- (propylsulfonyloxy) naphthyl dicarboxylimide, N- (butylsulfonyl) Oxy) naphthyl dicarboxylimide, N- (pentylsulfonyloxy) naphthyl dicarboxylimide, N- (hexylsulfonyloxy) naphthyl dicarbo Xylimide, N- (heptylsulfonyloxy) naphthyl dicarboxylimide, N- (octylsulfonyloxy) naphthyl dicarboxylimide, N- (nonylsulfonyloxy) naphthyl dicarboxylimide, and the like.

[Halogen-containing compounds]
Examples of the halogen-containing compound include haloalkyl group-containing hydrocarbon compounds and haloalkyl group-containing heterocyclic compounds.

[Diazomethane compounds]
Examples of the diazomethane compound include bis (trifluoromethylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, bis (phenylsulfonyl) diazomethane, bis (p-tolylsulfonyl) diazomethane, and bis (2,4-xylylsulfonyl) diazomethane. Bis (p-chlorophenylsulfonyl) diazomethane, methylsulfonyl-p-toluenesulfonyldiazomethane, cyclohexylsulfonyl (1,1-dimethylethylsulfonyl) diazomethane, bis (1,1-dimethylethylsulfonyl) diazomethane, phenylsulfonyl (benzoyl) diazomethane Etc.

[Sulfone compound]
Examples of the sulfone compounds include β-ketosulfone compounds, β-sulfonylsulfone compounds, diaryldisulfone compounds, and the like.

[Sulfonic acid ester compounds]
Examples of the sulfonate compound include alkyl sulfonate, haloalkyl sulfonate, aryl sulfonate, and imino sulfonate.

[Carboxylic ester compounds]
Examples of the carboxylic acid ester compound include carboxylic acid o-nitrobenzyl ester.

  [B] The acid generator is preferably an oxime sulfonate compound, an onium salt, or a sulfonate compound from the viewpoint of sensitivity and solubility. As the oxime sulfonate compound, a compound represented by the above formula (2) is preferable, a compound represented by the above formula (3) is more preferable, and is represented by the above formula (3-1), which is available as a commercial product. Are particularly preferred. As the onium salt, tetrahydrothiophenium salt and benzylsulfonium salt are preferable, and 4,7-di-n-butoxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate and benzyl-4-hydroxyphenylmethylsulfonium hexafluorophosphate are preferable. More preferred. As the sulfonic acid ester compound, a haloalkylsulfonic acid ester is preferable, and N-hydroxynaphthalimide-trifluoromethanesulfonic acid ester is more preferable.

  As content of the [B] acid generator in the said radiation sensitive resin composition, as a case where a [B] acid generator is a [B] acid generator, with respect to 100 mass parts of [A] polymers, Preferably they are 0.1 mass part-10 mass parts, More preferably, they are 1 mass part-5 mass parts. [B] By setting the content of the acid generator within the specific range, the sensitivity of the radiation-sensitive resin composition can be optimized, and an interlayer insulating film for a display element having a high surface hardness can be formed while maintaining transparency. .

<[C] sensitizer>
It is preferable that the said radiation sensitive resin composition further contains a [C] sensitizer as a suitable component. The sensitivity of the said radiation sensitive resin composition can be improved more because the said radiation sensitive resin composition further contains a [C] sensitizer. [C] The sensitizer absorbs actinic rays or radiation and enters an electronically excited state. The [C] sensitizer brought into the electronically excited state comes into contact with the acid generator, causing effects such as electron transfer, energy transfer, and heat generation, whereby the [B] acid generator undergoes a chemical change and decomposes. It produces acid.

  [C] Examples of the sensitizer include compounds belonging to the following compounds and having an absorption wavelength in the region of 350 nm to 450 nm.

[C] Examples of the sensitizer include pyrene, perylene, triphenylene, anthracene, 9,10-dibutoxyanthracene, 9,10-diethoxyanthracene, 3,7-dimethoxyanthracene, 9,10-dipropyloxyanthracene, and the like. Polynuclear aromatics of
Xanthenes such as fluorescein, eosin, erythrosine, rhodamine B, rose bengal;
Xanthones such as xanthone, thioxanthone, dimethylthioxanthone, diethylthioxanthone, isopropylthioxanthone;
Cyanines such as thiacarbocyanine, oxacarbocyanine;
Merocyanines such as merocyanine and carbomerocyanine;
Rhodocyanines;
Oxonols;
Thiazines such as thionine, methylene blue and toluidine blue;
Acridines such as acridine orange, chloroflavin, acriflavine;
Acridones such as acridone, 10-butyl-2-chloroacridone;
Anthraquinones such as anthraquinone;
Squariums such as squalium;
Styryls;
Base styryls such as 2- [2- [4- (dimethylamino) phenyl] ethenyl] benzoxazole;
7-diethylamino 4-methylcoumarin, 7-hydroxy 4-methylcoumarin, 2,3,6,7-tetrahydro-9-methyl-1H, 5H, 11H [l] benzopyrano [6,7,8-ij] quinolidine- Coumarins, such as 11-non, etc. are mentioned.

  Of these [C] sensitizers, polycyclic aromatics, xanthones, acridones, styryls, base styryls and coumarins are preferred, polycyclic aromatics and xanthones are more preferred, and 9,10- Dibutoxyanthracene and isopropylthioxanthone are particularly preferred.

  As content of the [C] sensitizer in the said radiation sensitive resin composition, 0.1 mass part-10 mass parts are preferable with respect to 100 mass parts of [A] polymers, and 0.5 mass part-5 Part by mass is more preferable. [D] By making content of a basic compound into the said specific range, a sensitivity can be improved more.

<Other optional components>
In addition to the above components [A] to [C], the radiation sensitive resin composition includes [D] basic compound, [E] surfactant, and [F] as long as the effects of the present invention are not impaired. It may contain other optional components such as an adhesion assistant and a compound having a [G] hindered phenol structure. These other optional components may be used alone or in combination of two or more. Hereinafter, each component will be described in detail.

<[D] Basic compound>
[D] The basic compound can be arbitrarily selected from those used in chemically amplified resists, for example, aliphatic amine, aromatic amine, heterocyclic amine, quaternary ammonium hydroxide, carboxylic acid quaternary ammonium. Examples include salts. By containing the [D] basic compound in the radiation sensitive resin composition, the diffusion length of the acid generated from the [B] acid generator by exposure can be appropriately controlled, and the pattern developability can be improved. .

  Examples of the aliphatic amine include trimethylamine, diethylamine, triethylamine, di-n-propylamine, tri-n-propylamine, di-n-pentylamine, tri-n-pentylamine, diethanolamine, triethanolamine, dicyclohexylamine, Examples include dicyclohexylmethylamine.

  Examples of the aromatic amine include aniline, benzylamine, N, N-dimethylaniline, diphenylamine and the like.

  Examples of the heterocyclic amine include pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, N-methyl-4-phenylpyridine, 4 -Dimethylaminopyridine, imidazole, benzimidazole, 4-methylimidazole, 2-phenylbenzimidazole, 2,4,5-triphenylimidazole, nicotine, nicotinic acid, nicotinamide, quinoline, 8-oxyquinoline, pyrazine, pyrazole , Pyridazine, purine, pyrrolidine, piperidine, piperazine, morpholine, 4-methylmorpholine, 1,5-diazabicyclo [4,3,0] -5-nonene, 1,8-diazabicyclo [5,3,0] -7undecene Etc.

  Examples of the quaternary ammonium hydroxide include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetra-n-butylammonium hydroxide, tetra-n-hexylammonium hydroxide, and the like.

  Examples of the carboxylic acid quaternary ammonium salt include tetramethylammonium acetate, tetramethylammonium benzoate, tetra-n-butylammonium acetate, and tetra-n-butylammonium benzoate.

  Of these [D] basic compounds, heterocyclic amines are preferable, and 4-dimethylaminopyridine, 4-methylimidazole, and 1,5-diazabicyclo [4,3,0] -5-nonene are more preferable.

  As content of the [D] basic compound in the said radiation sensitive resin composition, 0.001 mass part-1 mass part are preferable with respect to 100 mass parts of [A] polymers, and 0.005 mass part-0. More preferably, 2 parts by mass. [D] By making content of a basic compound into the said specific range, pattern developability improves more.

<[E] surfactant>
[E] The surfactant can further improve the film-forming property of the radiation-sensitive resin composition. Examples of the surfactant include a fluorine-based surfactant and a silicone-based surfactant. When the radiation sensitive resin composition contains [E] surfactant, the surface smoothness of the coating film can be improved, and as a result, the film thickness uniformity of the interlayer insulating film for display element formed can be further improved. it can.

  As the fluorosurfactant, a compound having a fluoroalkyl group and / or a fluoroalkylene group at at least one of the terminal, main chain and side chain is preferable. For example, 1,1,2,2-tetrafluoro n- Octyl (1,1,2,2-tetrafluoro n-propyl) ether, 1,1,2,2-tetrafluoro n-octyl (n-hexyl) ether, hexaethylene glycol di (1,1,2,2 , 3,3-hexafluoro n-pentyl) ether, octaethylene glycol di (1,1,2,2-tetrafluoro n-butyl) ether, hexapropylene glycol di (1,1,2,2,3,3) -Hexafluoro n-pentyl) ether, octapropylene glycol di (1,1,2,2-tetrafluoro n-butyl) ether, Sodium fluoro n-dodecanesulfonate, 1,1,2,2,3,3-hexafluoro n-decane, 1,1,2,2,3,3,9,9,10,10-decafluoro n- Dodecane, sodium fluoroalkylbenzenesulfonate, sodium fluoroalkylphosphate, sodium fluoroalkylcarboxylate, diglycerin tetrakis (fluoroalkylpolyoxyethylene ether), fluoroalkylammonium iodide, fluoroalkylbetaine, fluoroalkylpolyoxyethylene ether, Fluoroalkyl polyoxyethanol, perfluoroalkyl alkoxylate, carboxylic acid fluoroalkyl ester and the like can be mentioned.

  Examples of commercially available fluorosurfactants include BM-1000, BM-1100 (above, manufactured by BM CHEMIE), MegaFuck F142D, F172, F173, F183, F178, F191, F191, and F471. F476 (above, manufactured by Dainippon Ink and Chemicals), Florard FC-170C, FC-171, FC-430, FC-431 (above, manufactured by Sumitomo 3M), Surflon S-112, S-113, S-131, S-141, S-145, S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-105, SC-106 (and above) Asahi Glass Co., Ltd.), F-top EF301, EF303, EF352 (above, manufactured by Shin-Akita Kasei), Footent FT-100, FT-110, FT-140A, FT-150, FT-250, FT-251, FT-300, FT-310, FT-400S, FTX-218, FT-251 (above, Neos), etc. Is mentioned.

  Examples of the silicone-based surfactant include Torre Silicone DC3PA, DC7PA, SH11PA, SH21PA, SH28PA, SH29PA, SH30PA, SH-190, SH-193, SZ-6032, and SF-8428. DC-57, DC-190, SH 8400 FLUID (above, manufactured by Toray Dow Corning Silicone), TSF-4440, TSF-4300, TSF-4445, TSF-4446, TSF-4460, TSF-4252 (above, GE Toshiba Silicone), organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.) and the like.

  As content of [E] surfactant in the said radiation sensitive resin composition, Preferably it is 0.01 mass part or more and 2 mass parts or less with respect to 100 mass parts of [A] polymers, More preferably It is 0.05 mass part or more and 1 mass part or less. [E] The film thickness uniformity of a coating film can be improved more by making content of surfactant into the said specific range.

<[F] Adhesion aid>
[F] The adhesion assistant can be used to improve the adhesion between an insulating material and an inorganic substance serving as a substrate, for example, a silicone compound such as silicone, silicone oxide or silicone nitride, gold, copper or aluminum. As the adhesion assistant, a functional silane coupling agent is preferable. Examples of the functional silane coupling agent include a silane coupling agent having a reactive substituent such as a carboxyl group, a methacryloyl group, an isocyanate group, an epoxy group (preferably an oxiranyl group), and a thiol group.

  Examples of the functional silane coupling agent include trimethoxysilylbenzoic acid, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, γ-isocyanatopropyltriethoxysilane, γ-glycidoxypropyltri Examples include methoxysilane, γ-glycidoxypropylalkyldialkoxysilane, γ-chloropropyltrialkoxysilane, γ-mercaptopropyltrialkoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and the like. Of these, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylalkyldialkoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and γ-methacryloxypropyltrimethoxysilane are preferred. .

  The content of the [F] adhesion assistant in the radiation-sensitive resin composition is preferably 0.5 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the polymer [A], and 1 part by mass or more and 10 parts by mass. Less than the mass part is more preferable. [F] By setting the content of the adhesion assistant in the specific range, the adhesion between the formed interlayer insulating film for display elements and the substrate is further improved.

<[G] Compound having a hindered phenol structure>
[G] The compound having a hindered phenol structure is a component for preventing cleavage of the bond of the compound by a radical or a peroxide. [G] Examples of the compound having a hindered phenol structure include radical scavengers such as compounds having a hindered amine structure in addition to compounds having a hindered phenol structure.

  Examples of the compound having a hindered phenol structure include pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], thiodiethylenebis [3- (3,5-di-). tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, tris- (3,5-di-tert-butyl-4-hydroxy Benzyl) -isocyanurate, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, N, N′-hexane-1,6 -Diylbis [3- (3,5-di-tert-butyl-4-hydroxyphenylpropionamide), 3,3 , 3 ′, 5 ′, 5′-hexa-tert-butyl-a, a ′, a ′-(mesitylene-2,4,6-triyl) tri-p-cresol, 4,6-bis (octylthiomethyl) ) -O-cresol, 4,6-bis (dodecylthiomethyl) -o-cresol, ethylenebis (oxyethylene) bis [3- (5-tert-butyl-4-hydroxy-m-tolyl) propionate, hexamethylene Bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,3,5-tris [(4-tert-butyl-3-hydroxy-2,6-xylin) methyl] -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, 2,6-di-tert-butyl-4- (4,6-bis (octylthio) -1,3 5-to Azine-2-ylamine) phenol, and the like.

  Examples of the compound having a hindered amine structure include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (2,2,6,6-tetramethyl-4-piperidyl) succinate, bis ( 1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis (N-octoxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (N-benzyloxy-2, 2,6,6-tetramethyl-4-piperidyl) sebacate, bis (N-cyclohexyloxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6) -Pentamethyl-4-piperidyl) 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-butylmalonate, bis (1-acroyl-2, , 6,6-tetramethyl-4-piperidyl) 2,2-bis (3,5-di-t-butyl-4-hydroxybenzyl) -2-butylmalonate, bis (1,2,2,6, 6-pentamethyl-4-piperidyl) decandioate, 2,2,6,6-tetramethyl-4-piperidyl methacrylate, 4- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyl Oxy] -1- [2- (3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy) ethyl] -2,2,6,6-tetramethylpiperidine, 2-methyl-2 -(2,2,6,6-tetramethyl-4-piperidyl) amino-N- (2,2,6,6-tetramethyl-4-piperidyl) propionamide, tetrakis (2,2,6,6- Tetramethyl-4 Compounds such as piperidyl) 1,2,3,4-butanetetracarboxylate, tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate It is done.

  As content of the compound which has the [G] hindered phenol structure in the said radiation sensitive resin composition, 0.1 mass part or more and 10 mass parts or less are preferable with respect to 100 mass parts of [A] polymers, 1 More preferred is 5 parts by mass or more and 3 parts by mass or less. [G] By setting the content of the compound having a hindered phenol structure within the above specified range, the voltage holding ratio of the interlayer insulating film for a display element to be formed is maintained while maintaining the sensitivity of the radiation-sensitive resin composition. It can be improved further.

<Method for preparing radiation-sensitive resin composition>
The radiation-sensitive resin composition is prepared in a dissolved or dispersed state by mixing a [A] polymer, [B] acid generator, a suitable component as necessary, and other optional components in a solvent. . For example, the radiation sensitive resin composition can be prepared by mixing each component at a predetermined ratio in a solvent.

  As the solvent, a solvent in which each component is uniformly dissolved or dispersed and does not react with each component is preferably used. Examples of the solvent include alcohols, ethers, glycol ethers, ethylene glycol alkyl ether acetates, diethylene glycol alkyl ethers, propylene glycol monoalkyl ethers, propylene glycol monoalkyl ether acetates, propylene glycol monoalkyl ether propionates, and aromatic hydrocarbons. , Ketones, other esters and the like.

  Examples of alcohols include methanol, ethanol, benzyl alcohol, 2-phenylethyl alcohol, 3-phenyl-1-propanol and the like.

  Examples of ethers include tetrahydrofuran.

  Examples of glycol ethers include ethylene glycol monomethyl ether and ethylene glycol monoethyl ether.

  Examples of the ethylene glycol alkyl ether acetate include methyl cellosolve acetate, ethyl cellosolve acetate, ethylene glycol monobutyl ether acetate, and ethylene glycol monoethyl ether acetate.

  Examples of the diethylene glycol alkyl ether include diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and diethylene glycol ethyl methyl ether.

  Examples of the propylene glycol monoalkyl ether include propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether and the like.

  Examples of the propylene glycol monoalkyl ether acetate include propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate and the like.

  Examples of the propylene glycol monoalkyl ether propionate include propylene monoglycol methyl ether propionate, propylene glycol monoethyl ether propionate, propylene glycol monopropyl ether propionate, propylene glycol monobutyl ether propionate and the like. .

  Examples of aromatic hydrocarbons include toluene and xylene.

  Examples of ketones include methyl ethyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone, and the like.

  Examples of other esters include methyl acetate, ethyl acetate, propyl acetate, butyl acetate, ethyl 2-hydroxypropionate, methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, hydroxy Methyl acetate, ethyl hydroxyacetate, butyl hydroxyacetate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, methyl 3-hydroxypropionate, ethyl 3-hydroxypropionate, propyl 3-hydroxypropionate, butyl 3-hydroxypropionate Methyl 2-hydroxy-3-methylbutanoate, methyl methoxyacetate, ethyl methoxyacetate, propyl methoxyacetate, butyl methoxyacetate, methyl ethoxyacetate, ethyl ethoxyacetate, propyl ethoxyacetate, butyl ethoxyacetate, Methyl ropoxyacetate, ethyl propoxyacetate, propylpropoxyacetate, butyl propoxyacetate, methyl butoxyacetate, ethyl butoxyacetate, propylbutoxyacetate, butylbutoxyacetate, methyl 2-methoxypropionate, ethyl 2-methoxypropionate, 2-methoxypropion Propyl acid, butyl 2-methoxypropionate, methyl 2-ethoxypropionate, ethyl 2-ethoxypropionate, propyl 2-ethoxypropionate, butyl 2-ethoxypropionate, methyl 2-butoxypropionate, 2-butoxypropionic acid Ethyl, propyl 2-butoxypropionate, butyl 2-butoxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, propyl 3-methoxypropionate, 3-methyl Butyl xylpropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, propyl 3-ethoxypropionate, butyl 3-ethoxypropionate, methyl 3-propoxypropionate, ethyl 3-propoxypropionate, 3-propoxy Examples include propyl propionate, butyl 3-propoxypropionate, methyl 3-butoxypropionate, ethyl 3-butoxypropionate, propyl 3-butoxypropionate, and butyl 3-butoxypropionate.

  Of these solvents, ethylene glycol alkyl ether acetate, diethylene glycol alkyl ether, propylene glycol monoalkyl ether, propylene glycol monoalkyl ether acetate, and butyl methoxyacetate are preferred. Diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, propylene glycol monomethyl ether acetate, propylene More preferred are glycol monomethyl ether and butyl methoxyacetate.

<Method for forming interlayer insulating film for display element>
The said radiation sensitive resin composition is suitable as a forming material of the interlayer insulation film for display elements. Moreover, the interlayer insulation film for display elements formed from the said radiation sensitive resin composition is also suitably contained in this invention.

The method for forming an interlayer insulating film for a display element according to the present invention includes:
(1) The process of forming the coating film of the said radiation sensitive resin composition on a board | substrate,
(2) A step of irradiating at least a part of the coating film with radiation,
(3) a step of developing the coating film irradiated with the radiation; and (4) a step of heating the developed coating film.

  According to the formation method, an interlayer insulating film for a display element having high contact hole diameter stability can be formed. Further, since the amount of change in the film thickness of the unexposed portion can be suppressed, the production process margin can be improved as a result, and the yield can be improved. Furthermore, an interlayer insulating film for a display element having a fine and elaborate pattern can be easily formed by forming a pattern by exposure, development and heating utilizing photosensitivity. Therefore, the formed interlayer insulation film for display elements can be used suitably for display elements, such as a liquid crystal display element and an organic EL display element.

[Step (1)]
In this step, the radiation sensitive resin composition is applied onto a substrate to form a coating film. Preferably, the solvent is removed by prebaking the coated surface.

  Examples of the substrate include glass, quartz, silicone, and resin. Examples of the resin include polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, polyimide, a ring-opening polymer of cyclic olefin, and a hydrogenated product thereof. As prebaking conditions, although it changes also with kinds, compounding ratios, etc. of each component, it can be set as 70 degreeC-120 degreeC, about 1 minute-10 minutes.

[Step (2)]
In this step, at least a part of the formed coating film is exposed to radiation and exposed. When exposing, it exposes normally through the photomask which has a predetermined pattern. As the radiation used for exposure, radiation having a wavelength in the range of 190 nm to 450 nm is preferable, and radiation containing ultraviolet light of 365 nm is more preferable. Energy of exposure intensity at the wavelength 365nm radiation, by the value measured by luminometer (OAI model356, OAI Optical Ltd. ^Associates), is preferably ^{500J / m 2 ~6,000J / m 2} , 1,500J / m 2 ˜1,800 J / m ² is more preferable.

[Step (3)]
In this step, the coating film irradiated with the radiation is developed. By developing the coated film after exposure, unnecessary portions (radiation irradiated portions) are removed to form a predetermined pattern. As the developer used in the development step, an alkaline aqueous solution is preferable. Examples of the alkali include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and ammonia; quaternary ammonium salts such as tetramethylammonium hydroxide and tetraethylammonium hydroxide. .

  An appropriate amount of a water-soluble organic solvent such as methanol or ethanol, or a surfactant can be added to the alkaline aqueous solution. The concentration of alkali in the aqueous alkali solution is preferably from 0.1% by mass to 5% by mass from the viewpoint of obtaining appropriate developability. Examples of the developing method include a liquid piling method, a dipping method, a rocking dipping method, and a shower method. The development time varies depending on the composition of the radiation sensitive resin composition, but is about 10 seconds to 180 seconds. Subsequent to such development processing, for example, washing with running water is performed for 30 seconds to 90 seconds, and then a desired pattern can be formed by, for example, air drying with compressed air or compressed nitrogen.

Thickness change rate of the thickness T ₁ of the after development with respect to the film thickness T ₀ of the coating film before development is preferably 90% or more. As described above, according to the forming method using the radiation-sensitive resin composition, the amount of change in the film thickness of the unexposed portion with respect to the development time can be suppressed, and the film thickness after development is 90% of the film thickness before development. % Or more can be maintained.

[Step (4)]
In this step, the developed coating film is heated. For heating, a heating device such as a hot plate or an oven is used to heat the patterned thin film, thereby promoting the curing reaction of the [A] polymer and obtaining a cured product. As heating temperature, it is about 120 to 250 degreeC, for example. The heating time varies depending on the type of heating device, but for example, it is about 5 to 30 minutes for a hot plate and about 30 to 90 minutes for an oven. Moreover, the step baking method etc. which perform a heating process 2 times or more can also be used. In this way, a patterned thin film corresponding to the target display element interlayer insulating film can be formed on the surface of the substrate. Note that the use of the cured film is not limited to the interlayer insulating film for display elements, and can also be used as a spacer or a protective film. The film thickness of the formed interlayer insulating film for display element is preferably 0.1 μm to 8 μm, more preferably 0.1 μm to 6 μm.

  EXAMPLES Hereinafter, although this invention is explained in full detail based on an Example, this invention is not interpreted limitedly based on description of this Example.

<Synthesis of [A] Component>
[Synthesis Example 1]
A flask equipped with a condenser and a stirrer was charged with 7 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator and 200 parts by mass of diethylene glycol ethyl methyl ether. Subsequently, 85 parts by mass (74.3 mol%) of a compound (Z-1) represented by the following formula giving structural unit (I), 8 parts by mass (10.5 mol) of glycidyl methacrylate giving structural unit (II) %), 7 parts by mass (15.2 mol%) of methacrylic acid giving other structural units, and 3 parts by mass of α-methylstyrene dimer as a molecular weight modifier were charged with nitrogen, and then gently agitated. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the copolymer (A-1). Mw of the copolymer (A-1) was 8,000. The solid content concentration of the polymer solution was 31.1% by mass. As a result of ¹³ C-NMR analysis, the content of each structural unit was structural unit (I): structural unit (II): other structural unit = 74: 11: 15 (mol%). In addition, the ¹³ C-NMR analysis for calculating | requiring the content rate of each structural unit of a polymer used the nuclear magnetic resonance apparatus (the JEOL make, JNM-ECX400).

[Synthesis Example 2]
A flask equipped with a condenser and a stirrer was charged with 7 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator and 200 parts by mass of diethylene glycol ethyl methyl ether. Subsequently, 12 parts by mass (5.9 mol%) of a compound (Z-2) represented by the following formula giving structural unit (I), 40 parts by mass (36.5 mol) of glycidyl methacrylate giving structural unit (II) %), 15 parts by mass (22.6 mol%) of methacrylic acid to give other structural units, 8 parts by mass of styrene (10.0 mol%) and 25 parts by mass of 2-hydroxyethyl methacrylate (24.9 mol%) In addition, 3 parts by mass of α-methylstyrene dimer as a molecular weight modifier was charged and purged with nitrogen, and then gently stirred. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the copolymer (A-2). Mw of the copolymer (A-2) was 7,000. The solid content concentration of the polymer solution was 29.8% by mass. As a result of ¹³ C-NMR analysis, the content of each structural unit was structural unit (I): structural unit (II): other structural unit = 6: 37: 57 (mol%).

[Synthesis Example 3]
A flask equipped with a condenser and a stirrer was charged with 7 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator and 200 parts by mass of diethylene glycol ethyl methyl ether. Subsequently, 50 parts by mass (32.4 mol%) of the compound (Z-2) represented by the above formula giving the structural unit (I), 30 parts by mass (36.2 mol) of glycidyl methacrylate giving the structural unit (II) %), 5 parts by mass (10 mol%) of methacrylic acid to give other structural units, 5 parts by mass of styrene (8.2 mol%) and 10 parts by mass of 2-hydroxyethyl methacrylate (13.2 mol%), and After 3 parts by mass of α-methylstyrene dimer as a molecular weight modifier was charged and purged with nitrogen, stirring was started gently. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the copolymer (A-3). Mw of the copolymer (A-3) was 10,000. The solid content concentration of the polymer solution was 33.1% by mass. As a result of ¹³ C-NMR analysis, the content of each structural unit was structural unit (I): structural unit (II): other structural unit = 32: 36: 32 (mol%).

[Synthesis Example 4]
A flask equipped with a condenser and a stirrer was charged with 7 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator and 200 parts by mass of diethylene glycol ethyl methyl ether. Subsequently, 50 parts by mass (32.4 mol%) of a compound (Z-3) represented by the following formula giving structural unit (I), 30 parts by mass (36.2 mol) of glycidyl methacrylate giving structural unit (II) %), 5 parts by mass (10 mol%) of methacrylic acid to give other structural units, 5 parts by mass of styrene (8.2 mol%) and 10 parts by mass of 2-hydroxyethyl methacrylate (13.2 mol%), and After 3 parts by mass of α-methylstyrene dimer as a molecular weight modifier was charged and purged with nitrogen, stirring was started gently. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the copolymer (A-4). Mw of the copolymer (A-4) was 10,000. The solid content concentration of the polymer solution was 31.5% by mass. As a result of ¹³ C-NMR analysis, the content of each structural unit was structural unit (I): structural unit (II): other structural unit = 32: 36: 32 (mol%).

[Synthesis Example 5]
A flask equipped with a condenser and a stirrer was charged with 7 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator and 200 parts by mass of diethylene glycol ethyl methyl ether. Subsequently, 35 parts by mass (25.6 mol%) of the compound (Z-1) represented by the above formula giving the structural unit (I), 30 parts by mass (33.1 mol) of glycidyl methacrylate giving the structural unit (II) %), 5 parts by mass (9.1 mol%) of methacrylic acid to give other structural units, 5 parts by mass of styrene (7.5 mol%), 10 parts by mass of 2-hydroxyethyl methacrylate (12.1 mol%) Then, 15 parts by mass (12.6 mol%) of 1-n-butoxyethyl methacrylate and 3 parts by mass of α-methylstyrene dimer as a molecular weight modifier were charged and purged with nitrogen, and then gently stirring was started. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the copolymer (A-5). Mw of the copolymer (A-5) was 9,000. The solid content concentration of the polymer solution was 31.0% by mass. As a result of ¹³ C-NMR analysis, the content of each structural unit was structural unit (I): structural unit (II): other structural unit = 25: 33: 42 (mol%).

[Synthesis Example 6]
A flask equipped with a condenser and a stirrer was charged with 7 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator and 200 parts by mass of diethylene glycol ethyl methyl ether. Subsequently, 20 parts by mass (13.0 mol%) of the compound (Z-1) represented by the above formula giving the structural unit (I), 3-methacryloyloxymethyl-3-ethyloxetane 30 giving the structural unit (II) Parts by mass (27.9 mol%), 5 parts by mass (10.0 mol%) of methacrylic acid giving other structural units, 5 parts by mass of styrene (8.2 mol%), and 1-n-butoxyethyl methacrylate 30 parts by mass (27.7 mol%) and 3 parts by mass of α-methylstyrene dimer as a molecular weight modifier were charged and purged with nitrogen, and then gently agitated. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the copolymer (A-6). Mw of the copolymer (A-6) was 10,000. The solid content concentration of the polymer solution was 31.5% by mass. As a result of ¹³ C-NMR analysis, the content of each structural unit was structural unit (I): structural unit (II): other structural unit = 13: 28: 59 (mol%).

[Synthesis Example 7]
A flask equipped with a condenser and a stirrer was charged with 7 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator and 200 parts by mass of diethylene glycol ethyl methyl ether. Subsequently, 50 parts by mass (36.9 mol%) of the compound (Z-1) represented by the above formula giving the structural unit (I), 35 masses of 3,4-epoxycyclohexylmethyl methacrylate giving the structural unit (II) Parts (34.8 mol%), 5 parts by mass (11.4 mol%) of methacrylic acid giving other structural units, 5 parts by mass of styrene (9.4 mol%) and 5 parts by mass of 2-hydroxyethyl methacrylate ( 7.5 mol%) and 3 parts by mass of α-methylstyrene dimer as a molecular weight modifier were charged and purged with nitrogen, and then gently agitated. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing the copolymer (A-7). Mw of the copolymer (A-7) was 10,000. The solid content concentration of the polymer solution was 31.1% by mass. As a result of ¹³ C-NMR analysis, the content of each structural unit was structural unit (I): structural unit (II): other structural unit = 37: 35: 28 (mol%).

[Synthesis Example 8]
A flask equipped with a condenser and a stirrer was charged with 7 parts by mass of 2,2′-azobis (methyl 2-methylpropionate) as a polymerization initiator and 200 parts by mass of propylene glycol monomethyl ether acetate. Subsequently, 77 parts by mass (54.9 mol%) of 1-tricyclodecanyloxyethyl methacrylate giving structural unit (I) and 16 parts by mass (35.0 mol%) of methacrylic acid giving other structural units and methacryl After 7 parts by mass (10.1 mol%) of 2-hydroxyethyl acid was charged and purged with nitrogen, stirring was started gently. The temperature of the solution was raised to 80 ° C., and this temperature was maintained for 6 hours to obtain a polymer solution containing a copolymer (CA-1). Mw of the copolymer (CA-1) was 10,000. The solid content concentration of the polymer solution was 29.2% by mass. As a result of ¹³ C-NMR analysis, the content of each structural unit was structural unit (I): other structural unit = 55: 45 (mol%).

[Synthesis Example 9]
A flask equipped with a condenser and a stirrer was charged with 7 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator and 200 parts by mass of diethylene glycol ethyl methyl ether. Subsequently, 40 parts by mass of glycidyl methacrylate giving structural unit (II), and 25 parts by mass of 2-tetrahydropyranyl methacrylate and 35 parts by mass of benzyl methacrylate giving other structural units were charged, and the mixture was gently stirred. Started. The temperature of the solution was raised to 80 ° C., and this temperature was maintained for 6 hours to obtain a polymer solution containing a copolymer (CA-2). The Mw of the copolymer (CA-2) was 10,000. The solid content concentration of the polymer solution was 32.3% by mass.

[Synthesis Example 10]
A flask equipped with a condenser and a stirrer was charged with 7 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator and 200 parts by mass of diethylene glycol ethyl methyl ether. Subsequently, 40 parts by mass of glycidyl methacrylate giving structural unit (II), 5 parts by mass of methacrylic acid giving other structural units, 40 parts by mass of 1-ethoxyethyl methacrylate, 5 parts by mass of styrene and 2-hydroxyethyl methacrylate 10 Stirring was started gently after charging 3 parts by mass of 3 parts by mass of α-methylstyrene dimer as a molecular weight modifier and a molecular weight regulator. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing a copolymer (CA-3). Mw of the copolymer (CA-3) was 9,000. The solid content concentration of the polymer solution was 32.1% by mass.

[Synthesis Example 11]
A flask equipped with a condenser and a stirrer was charged with 7 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator and 200 parts by mass of diethylene glycol ethyl methyl ether. Subsequently, 5 parts by mass (2.3 mol%) of the compound (Z-1) represented by the above formula giving the structural unit (I), 40 parts by mass (34.9 mol) of glycidyl methacrylate giving the structural unit (II) %), 17 parts by mass (24.5 mol%) of methacrylic acid to give other structural units, 8 parts by mass of styrene (9.6 mol%) and 30 parts by mass of 2-hydroxyethyl methacrylate (28.6 mol%) In addition, 3 parts by mass of α-methylstyrene dimer as a molecular weight modifier was charged and purged with nitrogen, and then gently stirred. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing a copolymer (CA-4). The Mw of the copolymer (CA-4) was 10,000. The solid content concentration of the polymer solution was 31.2% by mass. As a result of ¹³ C-NMR analysis, the content of each structural unit was structural unit (I): structural unit (II): other structural unit = 2: 35: 63 (mol%).

[Synthesis Example 12]
A flask equipped with a condenser and a stirrer was charged with 7 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator and 200 parts by mass of diethylene glycol ethyl methyl ether. Subsequently, 98 parts by mass (95.2 mol%) of the compound (Z-1) represented by the above formula giving the structural unit (I), 1 part by mass (1.8 mol) of glycidyl methacrylate giving the structural unit (II) %), 1 part by mass (3.0 mol%) of methacrylic acid that gives other structural units, and 3 parts by mass of α-methylstyrene dimer as a molecular weight modifier were charged, and the mixture was gently stirred. The temperature of the solution was raised to 70 ° C., and this temperature was maintained for 5 hours to obtain a polymer solution containing a copolymer (CA-5). Mw of the copolymer (CA-5) was 6,000. The solid content concentration of the polymer solution was 27.8% by mass. As a result of ¹³ C-NMR analysis, the content of each structural unit was structural unit (I): structural unit (II): other structural unit = 95: 2: 3 (mol%).

<Preparation of radiation-sensitive resin composition>
Hereinafter, the components used for the preparation of the radiation sensitive resin compositions of Examples and Comparative Examples will be described in detail.

[B] Acid generator B-1: 4,7-di-n-butoxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate B-2: N-hydroxynaphthalimide-trifluoromethanesulfonate B-3: ( 5-Propylsulfonyloxyimino-5H-thiophen-2-ylidene)-(2-methylphenyl) acetonitrile (Ciba Specialty Chemicals, IRGACURE PAG 103)

[C] Sensitizer C-1: Isopropylthioxanthone C-2: Diethylthioxanthone

[D] Basic compound D-1: 4-dimethylaminopyridine D-2: 4-methylimidazole

[E] Surfactant E-1: Silicone surfactant (made by Toray Dow Corning Silicone, SH 8400 FLUID)
E-2: Fluorosurfactant (manufactured by Neos, Factent FTX-218)

[Example 1]
[A] A solution containing (A-1) as a polymer (an amount corresponding to 100 parts by mass (solid content) of (A-1)) and (B-1) as an acid generator. 5 parts by mass, [D] 0.01 part by mass of (D-1) as a basic compound, and [E] 0.20 part by mass of (E-1) as a surfactant are mixed, and the pore diameter is 0.2 μm. A radiation sensitive resin composition was prepared by filtering with a membrane filter.

[Examples 2 to 8 and Comparative Examples 1 to 3]
Each radiation-sensitive resin composition was prepared in the same manner as in Example 1 except that the types and blending amounts of the components were as described in Table 1. In Table 1, “-” indicates that the corresponding component was not used.

<Evaluation>
The following evaluation was implemented using each prepared radiation sensitive resin composition. The results are shown in Table 1.

[Sensitivity (J / m ² )]
Hexamethyldisilazane (HMDS) was applied to a 550 × 650 mm chromium-deposited glass substrate and heated at 60 ° C. for 1 minute. Each radiation sensitive resin composition is applied to the chromium film-formed glass substrate after the HMDS treatment using a slit die coater (manufactured by Tokyo Ohka Kogyo Co., Ltd., TR6322105-CL), and the ultimate pressure is set to 100 Pa under vacuum. After removing the solvent, the coating film was further baked at 90 ° C. for 2 minutes to form a coating film having a thickness of 3.0 μm. Subsequently, using an exposure machine (manufactured by Canon, MPA-600FA, ghi line mixture), the exposure amount was changed to the coating film through a mask having a 60 μm line and space (10 to 1) pattern. Irradiated. Then, it developed by the piling method for 80 seconds at 25 degreeC with 0.5 mass% tetramethylammonium hydroxide aqueous solution. Next, washing with running ultrapure water for 1 minute was performed, followed by drying to form a pattern on the chromium-deposited glass substrate after the HMDS treatment. At this time, the amount of exposure necessary to completely dissolve the 6 μm space pattern was examined. When this value was 500 (J / m ² ) or less, it was judged that the sensitivity was good. In Comparative Example 3, a pattern could not be formed, so “-” was shown in Table 1.

[Change in film thickness after development (%)]
HMDS was applied on an alkali-free glass substrate and heated for 3 minutes. After applying each radiation sensitive resin composition using a spinner, it was pre-baked on a hot plate at 90 ° C. for 2 minutes to form a coating film having a thickness of 4.1 μm. The obtained coating film was exposed through a contact hole pattern mask with an exposure gap of 30 μm and the same operation as in the sensitivity evaluation. Subsequently, development was performed by a paddle method at 23 ° C. with a 0.5 mass% tetramethylammonium hydroxide aqueous solution. At this time, the development time was changed to 50 seconds, 70 seconds, and 90 seconds. Thereafter, rinsing was performed with ultrapure water for 8 seconds. It measured about the film thickness T of the unexposed part after image development, and calculated the film thickness change rate (%) of the unexposed part after image development from this value and the following formula.
Change rate of film thickness after development (%) = {(film thickness T ₀ before development−film thickness T ₁ after development) / film thickness T ₀ before development} × 100
Even when the development time was changed to 50 seconds, 70 seconds, and 90 seconds, when the rate of change in film thickness was 90% or more, the amount of film reduction with respect to the development time was small, and it was judged good. In Comparative Example 3, a pattern could not be formed, so “-” was shown in Table 1.

[Thickness change rate after post-baking (%)]
The coating film having a film thickness of 4.1 μm is formed on the alkali-free glass substrate by operating in the same manner as the evaluation of the rate of change in film thickness after the development, the exposure is performed in the same manner, and the development time is 90 seconds. Thereafter, post-baking is performed in a clean oven at 220 ° C. for 45 minutes, and the film thickness T ₃ of the unexposed part is measured. From this value and the following formula, the film thickness change rate (%) of the unexposed part after post-baking is calculated. Calculated.
Film thickness change rate after post-baking (%) = {(film thickness T ₂ after coating film formation-film thickness T ₃ after post-baking) / film thickness T ₂ after coating film formation} × 100
When the film thickness change rate was 70% or more, it was judged that the film thickness change rate after post-baking was good.

[Contact hole shape stability (μm)]
The coating film was formed on the alkali-free glass substrate by operating in the same manner as the evaluation of the film thickness change rate, and the plate temperature was changed to 80 ° C., 90 ° C. and 100 ° C. Thereafter, except that the development time was set to 90 seconds, exposure and development were performed through a contact hole mask having a mask size of 10 μm in the same manner as the evaluation of the film thickness change rate after development, thereby forming a contact hole pattern. . Then, the contact hole pattern formed under each pre-baking temperature condition was baked at 220 ° C. for 45 minutes in a clean oven, and observed with a scanning electron microscope (SEM) to measure the shape and the size of the contact hole pattern. . When the size of the contact hole pattern was 9.5 μm to 10.5 μm, it was judged that the shape stability (μm) of the contact hole with respect to the change in the prebake temperature was good. In Comparative Example 3, a pattern could not be formed, so “-” was shown in Table 1.

  As is clear from the results in Table 1, Examples 1 to 8 using the radiation-sensitive resin composition are not sensitive to the development time after development in addition to good sensitivity compared to the compositions of Comparative Examples 1 to 3. It was found that the film thickness change amount at the exposed portion and the film thickness change amount after post-baking can be suppressed. It was also found that the interlayer insulating film for display elements formed from the radiation sensitive resin composition was also excellent in contact hole shape stability.

  The radiation-sensitive resin composition of the present invention can provide a radiation-sensitive resin composition having a small amount of change in film thickness of the unexposed portion after the development process and post-baking process, in addition to good sensitivity. In addition, the stability of the contact hole diameter can be improved. Since the amount of change in film thickness can be reduced, the production process margin can be improved as a result, and the yield can be improved. Furthermore, an interlayer insulating film for a display element having a fine and elaborate pattern can be easily formed by forming a pattern by exposure, development and heating utilizing photosensitivity. Therefore, the formed interlayer insulation film for display elements can be used suitably for display elements, such as a liquid crystal display element and an organic EL display element.

Claims (10)

[A] The content of the structural unit (I) including the structural unit (I) having a group represented by the following formula (1) and the structural unit (II) having an epoxy group in the same or different polymer molecules A radiation-sensitive resin composition containing a polymer having an amount of 10 mol% to 90 mol%.

(In formula (1), R ¹ and R ² are each independently a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group, provided that the hydrogen atom of the alkyl group, cycloalkyl group and aryl group is A part or all of them may be substituted, and R ¹ and R ² are not both hydrogen atoms, R ³ is a single bond, a methylene group or an alkylene group, R ⁴ is carbon It is an alicyclic hydrocarbon group having a number of 4 or more, or a heterocyclic group having 5 to 8. However, some or all of the hydrogen atoms of the alicyclic hydrocarbon group and the heterocyclic group are substituted. May be.) The radiation-sensitive resin composition according to claim _{1, wherein} a film thickness change rate of the film thickness T ₁ after development with respect to the film thickness T ₀ of the coating film before development is 90% or more.   The radiation sensitive resin composition according to claim 1 or 2, wherein the content of the structural unit (I) is 20 mol% or more and 50 mol% or less.   [B] The radiation-sensitive resin composition according to claim 1, 2, or 3, further comprising a radiation-sensitive acid generator. The R ⁴ in the above formula (1) is a polycyclic alicyclic hydrocarbon group having 7 or more carbon atoms, or a heterocyclic group having 5 to 8 members, according to any one of claims 1 to 4. Radiation sensitive resin composition. The radiation sensitive resin composition according to claim 5, wherein R ⁴ in the formula (1) is a polycyclic alicyclic hydrocarbon group having 7 or more carbon atoms.   [C] The radiation sensitive resin composition according to any one of claims 1 to 6, further comprising a sensitizer.   The radiation sensitive resin composition of any one of Claims 1-7 used for formation of the interlayer insulation film for display elements.   The interlayer insulation film for display elements formed from the radiation sensitive resin composition of Claim 8. (1) The process of forming the coating film of the radiation sensitive resin composition of Claim 8 on a board | substrate,
(2) A step of irradiating at least a part of the coating film with radiation,
(3) A method of forming an interlayer insulating film for a display element, comprising: a step of developing the coating film irradiated with the radiation; and (4) a step of heating the developed coating film.