JP4150922B2 - Method for forming laminate - Google Patents

Description

  The present invention relates to a laminated body, a method for forming a laminated body, an insulating layer, and a semiconductor substrate, and more specifically, a laminated body that can be used as an interlayer insulating layer material in a semiconductor device and has excellent resistance to plasma used during a processing process, and its formation The present invention relates to a method, an insulating layer made of the laminate, and a semiconductor substrate on which the insulating layer is formed.

Conventionally, a silica (SiO ₂ ) film formed by a vacuum process such as a CVD method is frequently used as an interlayer insulating layer in a semiconductor device or the like. In recent years, for the purpose of forming a more uniform interlayer insulating layer, a coating type insulating layer called a SOG (Spin on Glass) film containing a hydrolysis product of tetraalkoxylane as a main component has been used. It is becoming. In addition, with high integration of semiconductor devices and the like, an interlayer insulating layer having a low relative dielectric constant, which is mainly composed of polyorganosiloxane called organic SOG, has been developed.

In recent years, with further higher integration and multilayering of semiconductor devices and the like, there has been a demand for further improvement in electrical insulation between conductors. Therefore, an interlayer insulating layer having a lower relative dielectric constant and excellent mechanical strength. Materials have been demanded (see, for example, Patent Documents 1 and 2).
JP 2001-152023 A JP 2001-335748 A

  An object of the present invention is to provide a laminate that can be used as an interlayer insulating layer material in a semiconductor device and has excellent resistance to plasma used during a processing process, and a method for forming the same.

  Another object of the present invention is to provide an insulating layer made of the laminate and a semiconductor substrate on which the insulating layer is formed.

(1) The laminate of the present invention is
A first layer having a relative dielectric constant of 2.5 or less, obtained by curing an alkoxysilane hydrolyzed condensate, and obtained by curing an alkoxysilane hydrolyzed condensate having a relative dielectric constant of 2.5. And a second dielectric layer that exceeds the second dielectric layer, wherein a difference between a relative dielectric constant of the first layer and a relative dielectric constant of the second layer is 0.3 or more, and the first layer and the second layer A third layer containing Si and containing at least one element selected from the group of O, C, N, and H is formed between the second layer and the second layer.

  Here, the alkoxysilane hydrolysis condensate is a compound represented by the following general formula (1), a compound represented by the following general formula (2), and a compound represented by the following general formula (3). It may be a product obtained by hydrolytic condensation of at least one selected silane compound.

R _a Si (OR ¹ ) _4-a (1)
[Wherein, R represents a hydrogen atom, a fluorine atom or a monovalent organic group, R ¹ represents a monovalent organic group, and a represents an integer of 1 to 2. ]
Si (OR ² ) ₄ (2)
[Wherein R ² represents a monovalent organic group. ]
^{_{R 3 b (R 4 O)}} 3-b Si- (R 7) d -Si (OR 5) 3-c R 6 c ····· (3)
[Wherein, R ^{3 to} R ⁶ are the same or different and each represents a monovalent organic group, b and c are the same or different and represent a number of 0 to 2, and R ⁷ represents an oxygen atom, a phenylene group or-( CH _{2) n} - group represented by (wherein, n is an integer of 1 to 6), d represents 0 or 1. ]

(2) The method for forming the laminate of the present invention includes:
(A) A coating solution containing an alkoxysilane hydrolysis condensate is applied onto a substrate and dried to form a first coating film;
(B) applying a coating solution containing an alkoxysilane hydrolysis condensate to form a third coating film; and (c) an application containing the alkoxysilane hydrolysis condensate above the third coating film. After the liquid is applied to form the second coating film, the first, second, and third coating films are heated and cured, whereby the first layer having a relative dielectric constant of 2.5 or less, A second layer having a relative dielectric constant exceeding 2.5, and between the first layer and the second layer, containing Si and at least selected from the group of O, C, N, and H Forming a laminate including a third layer containing one kind of element. In the present application, the “base” refers to an object having a surface on which the first layer is formed. Examples of the “base” include a semiconductor substrate, an insulating layer, and a wiring layer.

Moreover, the method for forming the laminate of the present invention includes:
(A) A coating solution containing an alkoxysilane hydrolysis condensate is applied onto a substrate and dried to form a first coating film;
(B) A coating liquid containing an alkoxysilane hydrolysis condensate is applied to form a third coating film, and (c) a coating liquid containing an alkoxysilane hydrolysis condensate above the third coating film. Is applied to form a second coating film, and then the first, second, and third coating films are cured with an electron beam or an ultraviolet ray so that the first dielectric layer has a relative dielectric constant of 2.5 or less. And a second layer having a relative dielectric constant exceeding 2.5, and containing Si between the first layer and the second layer, and selected from the group of O, C, N, and H Forming a laminated body including a third layer containing at least one kind of element.

  (3) The insulating layer of this invention consists of the said laminated body. Further, the insulating layer is formed on the semiconductor substrate of the present invention.

  According to the laminate of the present invention, the second layer is formed above the first layer, and the third layer is provided between the first layer and the second layer. Accordingly, damage caused to the first layer by plasma used in a processing process (for example, a film formation process and an etching process of an insulating layer and a hard mask layer) can be reduced. Each of the first, second and third layers is a coating obtained by applying a coating solution containing an alkoxysilane hydrolysis condensate (first coating, second coating and third coating). Can be formed by curing. Thereby, the first, second and third layers are excellent in in-plane uniformity as compared with an insulating layer formed by, for example, a CVD method, and 100 nm even in an insulating layer of 10 to 100 nm, for example. Similar to the above insulating layer, it is uniform.

  Moreover, according to the method for forming a laminate of the present invention, a laminate having a low dielectric constant and reduced damage can be formed by a simple method.

  In addition, since the insulating layer of the present invention is composed of the stacked body, for example, when the insulating layer of the present invention is used as an interlayer insulating layer of a semiconductor device, a semiconductor device with reduced parasitic capacitance between wirings can be obtained. it can.

  Furthermore, according to the semiconductor substrate of the present invention, a semiconductor device with reduced parasitic capacitance between wirings can be obtained by forming the insulating layer.

  Hereinafter, a laminate and a method for forming the laminate, an insulating layer made of the laminate, and a semiconductor substrate on which the insulating layer is formed according to an embodiment of the present invention will be specifically described.

[Laminate]
FIG. 1 is a cross-sectional view schematically showing a laminate 100 according to an embodiment of the present invention. As shown in FIG. 1, the laminated body 100 of the present embodiment is configured by laminating a first layer 20 and a second layer 22 in order. A third layer 24 is formed between the first layer 20 and the second layer 22. That is, in the stacked body 100, the first layer 20 is formed on the substrate 10, and the second layer 22 is formed on the third layer 24.

  The first layer 20, the second layer 22, and the third layer 24 are all obtained by curing the alkoxysilane hydrolysis condensate. Detailed materials of the first layer 20, the second layer 22, and the third layer 24 will be described later. The first layer 20 is made of a low relative dielectric constant material. For this reason, the first layer 20 is susceptible to chemical and physical damage due to various reactive ions generated during a processing process using plasma. In order to reduce this damage, a second layer 22 having a relative dielectric constant larger than that of the first layer 20 is laminated on the first layer 20. Various reactive ions can be shielded by the second layer 22.

  The processing process using plasma is a process using plasma, and is not particularly limited. For example, plasma etching, plasma ashing, plasma CVD, plasma doping, surface treatment using plasma, plasma Annealing, plasma oxidation, etc. are mentioned.

  The relative dielectric constant of the first layer 20 is 2.5 or less, and preferably 2.2 to 2.5. If the relative dielectric constant of the first layer 20 exceeds 2.5, sufficient electrical insulation between conductors may not be ensured. The relative dielectric constant of the second layer 22 exceeds 2.5, and more preferably 2.7 to 3.0. When the relative dielectric constant of the second layer 22 is 2.5 or less, the second layer 22 cannot sufficiently shield various reactive ions during the processing process using plasma, Damage due to plasma may not be sufficiently reduced.

  Further, the difference between the relative dielectric constant of the first layer 20 and the relative dielectric constant of the second layer 22 is 0.3 or more, and more preferably 0.5 to 0.8. When the difference in relative dielectric constant is less than 0.3, the effect of shielding various reactive ions by the second layer 22 is reduced, so that damage to the first layer 20 due to plasma cannot be sufficiently reduced. is there.

  In the stacked body 100 shown in FIG. 1, the third layer 24 is formed on the first layer 20. Thereby, in the step of forming the second coating film for forming the second layer 22, when the coating liquid containing the alkoxysilane hydrolysis condensate is applied to form the second coating film, It is possible to prevent the alkoxysilane hydrolysis condensate in the coating liquid from diffusing into the pores in the first layer 20. Thereby, the shielding effect of the second layer 22 can be ensured, and the k value of the first layer 20 can be maintained at the design value.

(First layer and second layer)
In the present invention, each of the first and second layers is formed by curing a coating solution containing an alkoxysilane hydrolysis condensate. More specifically, the coating liquid used to form the first and second layers is (A) an alkoxysilane hydrolysis condensate (hereinafter also referred to as “component (A)”) and (B) an organic solvent. including. Here, (A) alkoxysilane hydrolysis condensate is a compound represented by the following general formula (1) (hereinafter referred to as “compound (1)”), a compound represented by the following general formula (2) (hereinafter referred to as “compound (1)”). , "Compound (2)") and at least one silane compound selected from the group of the following general formula (3) (hereinafter referred to as "compound (3)") is hydrolyzed and condensed And / or at least one hydrolyzate and / or a condensate thereof.

R _a Si (OR ¹ ) _4-a (1)
[Wherein, R represents a hydrogen atom, a fluorine atom or a monovalent organic group, R ¹ represents a monovalent organic group, and a represents an integer of 1 to 2. ]
Si (OR ² ) ₄ (2)
[Wherein R ² represents a monovalent organic group. ]
^{_{R 3 b (R 4 O)}} 3-b Si- (R 7) d -Si (OR 5) 3-c R 6 c ····· (3)
[Wherein, R ^{3 to} R ⁶ are the same or different and each represents a monovalent organic group, b and c are the same or different and represent a number of 0 to 2, and R ⁷ represents an oxygen atom, a phenylene group or-( CH _{2) n} - group represented by (wherein, n is an integer of 1 to 6), d represents 0 or 1. ]

Here, the “hydrolyzate” means that all of the R ¹ O— group, R ² O— group, R ⁴ O— group and R ⁵ O— group contained in the compounds (1) to (3) are hydrolyzed. It does not need to be decomposed, and for example, only one may be hydrolyzed, two or more may be hydrolyzed, or a mixture thereof. Here, the “condensate” is a product in which the silanol group of the hydrolyzate of the above compounds (1) to (3) is condensed to form a Si—O—Si bond. It is not necessary that all the silanol groups are condensed, and it is a concept that includes a mixture of a small part of the silanol groups, a mixture of those having different degrees of condensation, and the like.

Compound (1): In the above general formula (1), examples of the monovalent organic group represented by R and R ¹ include an alkyl group, an aryl group, an allyl group, and a glycidyl group. Especially, in General formula (1), it is preferable that R is a monovalent organic group, especially an alkyl group or a phenyl group. Here, examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, and preferably 1 to 5 carbon atoms. These alkyl groups may be linear or branched, Further, a hydrogen atom may be substituted with a fluorine atom or the like. In the general formula (1), examples of the aryl group include a phenyl group, a naphthyl group, a methylphenyl group, an ethylphenyl group, a chlorophenyl group, a bromophenyl group, and a fluorophenyl group. Preferred compounds as the compound (1) are methyltrimethoxysilane, methyltriethoxysilane, methyltri-n-propoxysilane, methyltri-iso-propoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, vinyltri Examples include ethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diphenyldimethoxysilane, and diphenyldiethoxysilane. These may be used alone or in combination of two or more.

Compound (2): In the general formula (2), examples of the monovalent organic group represented by R ² include the same organic groups as those shown in the general formula (1). Specific examples of the compound (2) include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-iso-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, tetra-tert-butoxy. Silane, tetraphenoxysilane, etc. are mentioned.

Compound (3): In the general formula (3), examples of the monovalent organic group represented by R ^{3 to} R ⁶ include the same organic groups as those shown in the general formula (1). it can. Among the compounds (3), compounds in which R ⁷ in the general formula (3) is an oxygen atom include hexamethoxydisiloxane, hexaethoxydisiloxane, 1,1,3,3-tetramethoxy-1,3-dimethyldisiloxane. 1,1,3,3-tetraethoxy-1,3-dimethyldisiloxane, 1,1,3,3-tetramethoxy-1,3-diphenyldisiloxane, 1,3-dimethoxy-1,1,3 , 3-tetramethyldisiloxane, 1,3-diethoxy-1,1,3,3-tetramethyldisiloxane, 1,3-dimethoxy-1,1,3,3-tetraphenyldisiloxane, 1,3- Preferred examples include diethoxy-1,1,3,3-tetraphenyldisiloxane. In the general formula (3), d = 0 compounds include hexamethoxydisilane, hexaethoxydisilane, 1,1,2,2-tetramethoxy-1,2-dimethyldisilane, 1,1,2,2-tetraethoxy. -1,2-dimethyldisilane, 1,1,2,2-tetramethoxy-1,2-diphenyldisilane, 1,2-dimethoxy-1,1,2,2-tetramethyldisilane, 1,2-diethoxy- 1,1,2,2-tetramethyldisilane, 1,2-dimethoxy-1,1,2,2-tetraphenyldisilane, 1,2-diethoxy-1,1,2,2-tetraphenyldisilane, etc. It can be mentioned as a preferred example.

Furthermore, in the general formula (3), R ⁷ is a group represented by — (CH ₂ ) _n —, and bis (trimethoxysilyl) methane, bis (triethoxysilyl) methane, 1,2-bis (Trimethoxysilyl) ethane, 1,2-bis (triethoxysilyl) ethane, 1- (dimethoxymethylsilyl) -1- (trimethoxysilyl) methane, 1- (diethoxymethylsilyl) -1- (triethoxy Silyl) methane, 1- (dimethoxymethylsilyl) -2- (trimethoxysilyl) ethane, 1- (diethoxymethylsilyl) -2- (triethoxysilyl) ethane, bis (dimethoxymethylsilyl) methane, bis (di Ethoxymethylsilyl) methane, 1,2-bis (dimethoxymethylsilyl) ethane, 1,2-bis (diethoxymethylsilyl) ethane 1,2-bis (trimethoxysilyl) benzene, 1,2-bis (triethoxysilyl) benzene, 1,3-bis (trimethoxysilyl) benzene, 1,3-bis (triethoxysilyl) benzene, Preferred examples include 1,4-bis (trimethoxysilyl) benzene, 1,4-bis (triethoxysilyl) benzene, and the like.

  In the present invention, as the compounds (1) to (3), one or more of the above compounds (1), (2) and (3) can be used. A catalyst may be used when hydrolyzing and condensing the compounds (1) to (3). Examples of the catalyst used at this time include metal chelate compounds, organic acids, inorganic acids, organic bases, and inorganic bases.

Examples of the metal chelate compound include triethoxy mono (acetylacetonato) titanium, tri-n-propoxy mono (acetylacetonato) titanium, tri-i-propoxy mono (acetylacetonato) titanium, tri-n- Butoxy mono (acetylacetonato) titanium, tri-sec-butoxy mono (acetylacetonato) titanium, tri-tert-butoxy mono (acetylacetonato) titanium, diethoxybis (acetylacetonato) titanium, di- n-propoxy bis (acetylacetonato) titanium, di-i-propoxy bis (acetylacetonato) titanium, di-n-butoxy bis (acetylacetonato) titanium, di-sec-butoxy bis (acetylacetate) Naruto) titanium, di-tert- Toxi-bis (acetylacetonato) titanium, monoethoxy-tris (acetylacetonato) titanium, mono-n-propoxy-tris (acetylacetonato) titanium, mono-i-propoxy-tris (acetylacetonato) titanium, mono -N-butoxy-tris (acetylacetonato) titanium, mono-sec-butoxy-tris (acetylacetonato) titanium, mono-tert-butoxy-tris (acetylacetonato) titanium, tetrakis (acetylacetonato) titanium, triethoxy -Mono (ethyl acetoacetate) titanium, tri-n-propoxy, mono (ethyl acetoacetate) titanium, tri-i-propoxy, mono (ethyl acetoacetate) titanium, tri-n-butoxy mono (ethyl acetoacetate) Tan, tri-sec-butoxy mono (ethyl acetoacetate) titanium, tri-tert-butoxy mono (ethyl acetoacetate) titanium, diethoxy bis (ethyl acetoacetate) titanium, di-n-propoxy bis (ethyl aceto) Acetate) titanium, di-i-propoxy bis (ethyl acetoacetate) titanium, di-n-butoxy bis (ethyl acetoacetate) titanium, di-sec-butoxy bis (ethyl acetoacetate) titanium, di-tert- Butoxy bis (ethyl acetoacetate) titanium, monoethoxy tris (ethyl acetoacetate) titanium, mono-n-propoxy tris (ethyl acetoacetate) titanium, mono-i-propoxy tris (ethyl acetoacetate) titanium, mono -N-bu Toxi-tris (ethyl acetoacetate) titanium, mono-sec-butoxy-tris (ethyl acetoacetate) titanium, mono-tert-butoxy-tris (ethyl acetoacetate) titanium, tetrakis (ethyl acetoacetate) titanium, mono (acetylacetate) Titanium chelate compounds such as nato) tris (ethylacetoacetate) titanium, bis (acetylacetonato) bis (ethylacetoacetate) titanium, tris (acetylacetonato) mono (ethylacetoacetate) titanium;
Triethoxy mono (acetylacetonato) zirconium, tri-n-propoxy mono (acetylacetonato) zirconium, tri-i-propoxy mono (acetylacetonato) zirconium, tri-n-butoxy mono (acetylacetonate) Zirconium, tri-sec-butoxy mono (acetylacetonato) zirconium, tri-tert-butoxy mono (acetylacetonato) zirconium, diethoxybis (acetylacetonato) zirconium, di-n-propoxybis (acetylacetate) Nato) zirconium, di-i-propoxy bis (acetylacetonato) zirconium, di-n-butoxy bis (acetylacetonato) zirconium, di-sec-butoxy bis (acetylacetonate) Zirconium, di-tert-butoxy bis (acetylacetonato) zirconium, monoethoxy tris (acetylacetonato) zirconium, mono-n-propoxytris (acetylacetonato) zirconium, mono-i-propoxytris (acetyl) Acetonato) zirconium, mono-n-butoxy-tris (acetylacetonato) zirconium, mono-sec-butoxy-tris (acetylacetonato) zirconium, mono-tert-butoxy-tris (acetylacetonato) zirconium, tetrakis (acetyl) Acetonato) zirconium, triethoxy mono (ethyl acetoacetate) zirconium, tri-n-propoxy mono (ethyl acetoacetate) zirconium, tri-i-propoxy Mono (ethyl acetoacetate) zirconium, tri-n-butoxy mono (ethyl acetoacetate) zirconium, tri-sec-butoxy mono (ethyl acetoacetate) zirconium, tri-tert-butoxy mono (ethyl acetoacetate) zirconium, Diethoxy bis (ethyl acetoacetate) zirconium, di-n-propoxy bis (ethyl acetoacetate) zirconium, di-i-propoxy bis (ethyl acetoacetate) zirconium, di-n-butoxy bis (ethyl acetoacetate) Zirconium, di-sec-butoxy bis (ethyl acetoacetate) zirconium, di-tert-butoxy bis (ethyl acetoacetate) zirconium, monoethoxy tris (ethyl acetoacetate) Zirconium, mono-n-propoxy tris (ethyl acetoacetate) zirconium, mono-i-propoxy tris (ethyl acetoacetate) zirconium, mono-n-butoxy tris (ethyl acetoacetate) zirconium, mono-sec -Butoxy tris (ethyl acetoacetate) zirconium, mono-tert-butoxy tris (ethyl acetoacetate) zirconium, tetrakis (ethyl acetoacetate) zirconium, mono (acetylacetonate) tris (ethyl acetoacetate) zirconium, bis (acetyl Zirconium chelate compounds such as acetonato) bis (ethylacetoacetate) zirconium, tris (acetylacetonato) mono (ethylacetoacetate) zirconium;
And aluminum chelate compounds such as tris (acetylacetonate) aluminum and tris (ethylacetoacetate) aluminum.

  Examples of organic acids include acetic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, oxalic acid, maleic acid, methylmalonic acid, adipic acid, sebacic acid, gallic acid Acid, butyric acid, meritic acid, arachidonic acid, shikimic acid, 2-ethylhexanoic acid, oleic acid, stearic acid, linoleic acid, linolenic acid, salicylic acid, benzoic acid, p-aminobenzoic acid, p-toluenesulfonic acid, benzenesulfone Examples thereof include acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoroacetic acid, formic acid, malonic acid, sulfonic acid, phthalic acid, fumaric acid, citric acid, and tartaric acid. Examples of inorganic acids include hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid, and phosphoric acid.

  Examples of the organic base include pyridine, pyrrole, piperazine, pyrrolidine, piperidine, picoline, trimethylamine, triethylamine, monoethanolamine, diethanolamine, dimethylmonoethanolamine, monomethyldiethanolamine, triethanolamine, diazabicycloocrane, diazabicyclo. Nonane, diazabicycloundecene, tetramethylammonium hydroxide, urea, creatinine and the like can be mentioned. Examples of the inorganic base include ammonia, sodium hydroxide, potassium hydroxide, barium hydroxide, calcium hydroxide and the like.

Of these catalysts, metal chelate compounds, organic acids, and inorganic acids are preferable, and organic acids can be more preferable. As the organic acid, acetic acid, oxalic acid, maleic acid, and malonic acid are particularly preferable. When using an organic acid as a catalyst, there is little possibility of polymer precipitation or gelation during hydrolysis and condensation reactions. These catalysts may be used alone or in combination of two or more. The amount of the catalyst used is usually 0.00001 to 0.05 mol, preferably 0.00001 to 0.01 mol, relative to 1 mol of the total amount of R ¹ O groups in the compounds (1) to (3). It is. When the component (A) is a condensate of the compounds (1) to (3), the molecular weight is a polystyrene-equivalent weight average molecular weight, usually 500 to 300,000, preferably 700 to 200,000. More preferably, it is about 1,000 to 100,000.

When each component is converted into a completely hydrolyzed condensate, the compound (3) is 5 to 60% by weight, preferably 5 to 50% by weight based on the total amount of the compound (1), the compound (2) and the compound (3). %, More preferably 5 to 40% by weight, and [weight of compound (1)] <[weight of compound (2)]. When the compound (3) is less than 5% by weight of the total amount of the compound (1) to the compound (3) in the proportion of each component converted into a complete hydrolysis condensate, the mechanical strength of the resulting coating film is reduced. If it exceeds 60% by weight, the water absorption is increased and the electrical characteristics may be deteriorated. Moreover, the intensity | strength of the coating film obtained as the weight of a compound (1) is more than the weight of a compound (2) may be inferior. In the present invention, the completely hydrolyzed condensate means a compound in which the SiOR ¹ group of the compounds (1) to (3) is 100% hydrolyzed to become a SiOH group, and further completely condensed to a siloxane structure. Say.

(3rd layer)
The third layer contains Si and contains at least one element selected from the group consisting of O, C, N, and H. This third layer can be formed of the same material as the first and second layers described above. In this case, similarly to the first layer and the second layer described above, the third layer is coated with a coating solution containing an alkoxysilane hydrolysis condensate to form a third coating film. It can be formed by curing the coating film.

[Method for forming laminate]
The laminate of the present invention comprises: (a) a coating solution containing an alkoxysilane hydrolysis condensate is applied on a substrate and dried to form a first coating film; and (b) an alkoxysilane hydrolysis condensate is contained. A coating liquid is applied to form a third coating film, and (c) a second coating film is formed by applying a coating liquid containing an alkoxysilane hydrolysis condensate above the third coating film. After that, the first, second and third coating films are obtained by heat curing, electron beam or ultraviolet curing to form the first layer, the second layer and the third layer. More specifically, the first layer is obtained from the first coating film, the second layer is obtained from the second coating film, and the third layer is obtained from the third coating film. The alkoxysilane hydrolysis condensate of (a) to (c) is formed by applying a coating solution obtained by dissolving the silane compound in the above-described hydrolysis and condensate in (B) an organic solvent, It is preferable to form this coating film by heating.

  (B) As an organic solvent, at least 1 sort (s) chosen from the group of alcohol solvent, ketone solvent, amide solvent, ester solvent, and aprotic solvent is mentioned. Here, as alcohol solvents, n-propanol, i-propanol, n-butanol, i-butanol, sec-butanol, tert-butanol, n-pentanol, i-pentanol, 2-methylbutanol, sec- Pentanol, tert-pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, sec-hexanol, 2-ethylbutanol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene Glycol monobutyl ether and the like are preferable.

  Examples of ketone solvents include acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, diethyl ketone, methyl-i-butyl ketone, methyl-n-pentyl ketone, ethyl-n-butyl ketone, and methyl-n-hexyl. In addition to ketones, di-i-butyl ketone, trimethylnonanone, cyclohexanone, 2-hexanone, methylcyclohexanone, 2,4-pentanedione, acetonylacetone, acetophenone, fenchon, acetylacetone, 2,4-hexanedione, 2 , 4-heptanedione, 3,5-heptanedione, 2,4-octanedione, 3,5-octanedione, 2,4-nonanedione, 3,5-nonanedione, 5-methyl-2,4-hexanedione, 2,2,6,6-tetramethyl-3, - heptanedione, 1,1,1,5,5,5 beta-diketones such as hexafluoro-2,4-heptane dione and the like. These ketone solvents may be used alone or in combination of two or more.

  Examples of amide solvents include formamide, N-methylformamide, N, N-dimethylformamide, N-ethylformamide, N, N-diethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, N-ethylacetamide N, N-diethylacetamide, N-methylpropionamide, N-methylpyrrolidone, N-formylmorpholine, N-formylpiperidine, N-formylpyrrolidine, N-acetylmorpholine, N-acetylpiperidine, N-acetylpyrrolidine, etc. Can be mentioned. These amide solvents may be used alone or in combination of two or more.

  Examples of ester solvents include diethyl carbonate, ethylene carbonate, propylene carbonate, diethyl carbonate, methyl acetate, ethyl acetate, γ-butyrolactone, γ-valerolactone, n-propyl acetate, i-propyl acetate, n-butyl acetate, and i-acetate. -Butyl, sec-butyl acetate, n-pentyl acetate, sec-pentyl acetate, 3-methoxybutyl acetate, methyl pentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methylcyclohexyl acetate, n-acetate -Nonyl, methyl acetoacetate, ethyl acetoacetate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl acetate Glycol mono-n-butyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, dipropylene Glycol acetate, methoxytriglycol acetate, ethyl propionate, n-butyl propionate, i-amyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate, n-butyl lactate, n-lactate Examples include amyl, diethyl malonate, dimethyl phthalate, and diethyl phthalate. These ester solvents may be used alone or in combination of two or more.

  As aprotic solvents, acetonitrile, dimethyl sulfoxide, N, N, N ′, N′-tetraethylsulfamide, hexamethylphosphoric triamide, N-methylmorpholone, N-methylpyrrole, N-ethylpyrrole, N -Methyl-tri-pyrroline, N-methylpiperidine, N-ethylpiperidine, N, N-dimethylpiperazine, N-methylimidazole, N-methyl-4-piperidone, N-methyl-2-piperidone, N-methyl- Examples include 2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 1,3-dimethyltetrahydro-2 (1H) -pyrimidinone. The above organic solvents can be used alone or in combination of two or more.

  (B) As the organic solvent, alcohol solvents are preferable among the above organic solvents. Examples of the coating method for the coating liquid include spin coating, dipping, roller blades, and spraying. In this case, as a dry film thickness, it is possible to form a coating film having a thickness of about 0.05 to 1.5 μm by one coating and a thickness of about 0.1 to 3 μm by two coatings.

  Further, after the first, second and third coating films are formed, the first layer, the second layer and the third layer are cured by heating, or by irradiation with an electron beam or ultraviolet ray for curing. Can be obtained.

  In the case of heat-curing, for example, it is dried at room temperature, or usually heated at a temperature of about 80 to 600 ° C. for about 5 to 240 minutes for drying. In this case, a hot plate, an oven, a furnace, or the like can be used as a heating method, and the heating atmosphere is an atmosphere, a nitrogen atmosphere, an argon atmosphere, a vacuum, a reduced pressure with a controlled oxygen concentration, or the like. Can do. Further, in order to control the curing rate of the coating solution, it is possible to heat stepwise or select an atmosphere such as nitrogen, air, oxygen, or reduced pressure as necessary.

  Examples of the electron beam include X-rays and γ-rays. Moreover, although the irradiation time of an electron beam or an ultraviolet-ray changes with materials and kinds of a coating film, it is generally 1-30 minutes, More preferably, 1-10 minutes are good. More preferably, hot plate heating can be used in combination at a temperature of about 80 to 600 ° C. for the purpose of enhancing the effect of electron beams or ultraviolet rays.

[Insulating layer and semiconductor substrate]
Since the laminate of the present invention is excellent in plasma resistance and exhibits a low relative dielectric constant, an interlayer insulating layer for semiconductor devices such as LSI, system LSI, DRAM, SDRAM, RDRAM, and D-RDRAM, and a surface coat of the semiconductor device It is useful for applications such as a protective layer such as a film, an intermediate layer in a semiconductor manufacturing process using a multilayer resist, an interlayer insulating layer of a multilayer wiring board, a protective layer or an insulating layer for a liquid crystal display device.

[Application example]
Next, an application example of the laminate 100 (see FIG. 1) of the present embodiment will be described. FIG. 2 is a cross-sectional view schematically showing the wiring structure 400. In the wiring structure 400, the stacked body 100 shown in FIG. 1 is used as an insulating layer. The wiring structure 400 functions as a wiring layer and a via layer of the semiconductor device. In this wiring structure 400, the laminate 200 may be applied instead of the laminate 100.

  More specifically, the wiring structure 400 includes a conductive layer 90 formed by a dual damascene method. More specifically, the conductive layer 90 includes a via layer 92 and a wiring layer 94 provided continuously on the via layer 92. The via layer 92 is embedded in the first opening 72 provided in the stacked body 100, and the wiring layer 94 is embedded in the second opening 74 provided in the organic insulating layer 40. Note that the wiring layer 94 is not limited to the first wiring layer, and may be a second or higher wiring layer. In addition, here, an example in which the laminated body of the present invention is applied as an insulating layer of a wiring structure formed by a damascene method has been described. However, the laminated body of the present invention is a wiring structure formed by a damascene method. The present invention is not only applied as an insulating layer, but can be applied to any insulating layer in a semiconductor device.

  The stacked body 100 is provided above the semiconductor substrate 110, and the organic insulating layer 40 is provided on the stacked body 100. More specifically, a diffusion prevention layer 82 is provided on the semiconductor substrate 110, the semiconductor substrate 110 constitutes a base, and the stacked body 100 is provided on the diffusion prevention layer 82. Further, the diffusion prevention layer 82 and the conductive layer 90 are in contact with each other at the bottom surface of the first opening 72. As shown in FIG. 2, the side surfaces of the first opening 72 and the second opening 74 may be covered with a barrier layer 80. That is, in this case, the stacked body 100 and the via layer 92 and the organic insulating layer 40 and the wiring layer 94 are adjacent to each other with the barrier layer 80 interposed therebetween. A cap layer 42 can be provided on the organic insulating layer 40.

  Examples of the organic insulating layer 40 include organic polymers selected from polyarylene, polyarylene ether, polyimide, polybenzoxazole, polybenzobisoxazole, polytriazole, polyphenylquinoxaline, polyquinoline, polyquinoxaline, and the like. In particular, polyarylene and polyarylene ether are preferable. Further, as the organic insulating layer 40, the above organic polymers can be used alone or in combination of two or more.

  This wiring structure 400 can be formed by the following method, for example. First, after forming the diffusion prevention layer 82 on the semiconductor substrate 110, the laminated body 100 is formed on this diffusion prevention layer 82 (refer FIG. 3). Next, the organic insulating layer 40 and the cap layer 42 are sequentially formed on the stacked body 100 (see FIG. 3). Next, an opening (through hole) 70 that penetrates the cap layer 42, the organic insulating layer 40, and the stacked body 100 is formed (see FIG. 4). Specifically, first, after forming a resist layer (not shown) on the cap layer 42, a resist layer R1 having a predetermined pattern is formed by a general photolithography process. The resist layer R1 has a pattern for forming an opening 70 (see FIG. 4) described later. Next, the opening 70 is formed by patterning the cap layer 42, the organic insulating layer 40, and the stacked body 100 using the resist layer R 1 as a mask (see FIG. 4). Thereafter, the resist layer R1 is removed by ashing or the like. Note that, when the organic insulating layer 40 is formed by coating, as in the case of the stacked body 100, a stacked structure can be formed with only one device (spin-on process device), which improves throughput during semiconductor manufacturing. A big contribution.

  Next, the first opening 72 is formed in the stacked body 100, and the second opening 74 is formed in the organic insulating layer 40 (see FIG. 5). Specifically, first, after forming a resist layer (not shown) on the cap layer 42, a resist layer R2 having a predetermined pattern is formed by a general photolithography process. The resist layer R2 has a pattern for forming a second opening 74 (see FIG. 5) described later. Next, by using the resist layer R2 as a mask, the cap layer 42 and the organic insulating layer 40 are patterned by etching using plasma to form the first opening 72 and the second opening 74. Thereafter, the resist layer R2 is removed by ashing or the like. Alternatively, first, the organic insulating layer 40 may be patterned to form the second opening 74, and then the first opening 72 may be formed by patterning the stacked body.

  As an etching method of the cap layer 42 and the stacked body 100, an etching method using various plasmas (for example, anisotropic plasma etching, reactive plasma etching, inductively coupled plasma etching, ECR plasma etching) or the like may be used. it can. Also, as an etching method for the organic insulating layer 40 and an ashing method for the resist layers R1 and R2, oxygen plasma treatment, ammonia plasma treatment, hydrogen / nitrogen mixed gas plasma treatment, and dry containing nitrogen / oxygen mixed gas as main components are possible. An etching process can be exemplified.

  Next, the barrier layer 80 is formed on the surfaces of the first opening 72 and the second opening 74 by using, for example, a CVD method or a sputtering method (see FIG. 6). Next, a conductive layer 90 (see FIG. 2) is formed in the first opening 72 and the second opening 74. Specifically, after forming a copper seed layer (not shown) by, for example, the PVD method, the conductive material 90a is embedded in the first opening 72 and the second opening 74 by plating. Next, the conductive material 90a is planarized by CMP. Thereby, the part formed on the cap layer 42 among the electroconductive materials 90a is removed, and the electroconductive layer 90 is obtained (refer FIG. 2). That is, a via layer 92 is formed in the first opening 72, and a wiring layer 94 is formed in the second opening 74. Next, the stopper layer 32 is formed on the conductive layer 90 and the cap layer 42 as necessary. Through the above steps, the wiring structure 400 is obtained (see FIG. 2).

  In the process described above, the first opening 72 that penetrates the stacked body 100 is provided, and the second opening 74 is provided in the organic insulating layer 40. In the stacked body 100, the second layer 22 is provided on the first layer 20. Therefore, in the step of forming the second opening 74 by patterning the organic insulating layer 40 by etching using plasma in the above-described steps (see FIG. 5), the reactive ions 13 generated by the plasma etching are changed to the first. Two layers 22 can be shielded. Thereby, it is possible to prevent the first layer 20 from being damaged.

  On the other hand, when the second layer 22 is not formed on the first layer 20, as shown in FIG. 7, the first layer 20 is exposed to the reactive ions 13 generated by plasma etching. Damage occurs in the vicinity of the exposed surface 20 a of the first layer 20.

  In this example, an example in which the organic insulating layer 40 is patterned by etching using plasma is shown. However, when performing etching using plasma, an inorganic insulating layer is used instead of the organic insulating layer 40. However, the same problem arises.

  In the wiring structure 400, the second layer 22 is provided on the first layer 20 via the third layer 24 (see FIG. 2). Thus, by forming the third layer 24 between the first layer 20 and the second layer 22, the second coating film is formed using a coating liquid containing an alkoxysilane hydrolysis condensate. When the second coating film is cured to form the second layer 22, the alkoxysilane hydrolysis condensate is prevented from diffusing into the pores in the first layer 20. be able to. Thereby, while the shielding effect with respect to the reactive ion of the 2nd layer 22 can be ensured, k value of the 1st layer 20 can be maintained at a design value.

[Example]
Next, the present invention will be described more specifically with reference to examples. However, the following description shows the aspect of this invention generally, and this invention is not limited by this description without a particular reason. Moreover, each evaluation in an Example was measured as follows.

(Weight average molecular weight (Mw))
It measured by the gel permeation chromatography (GPC) method by the following conditions.

  Sample: Prepared by using tetrahydrofuran as a solvent and dissolving 1 g of hydrolysis condensate in 100 ml of tetrahydrofuran.

  Standard polystyrene: Standard polystyrene manufactured by US Pressure Chemical Company was used.

Apparatus: High-temperature high-speed gel permeation chromatogram (Model 150-C ALC / GPC) manufactured by Waters, USA
Column: SHODEX A-80M (length: 50 cm) manufactured by Showa Denko K.K.
Measurement temperature: 40 ° C
Flow rate: 1cc / min (dielectric constant)
Aluminum was vapor-deposited on the substrate on which the cured film was formed to produce a dielectric constant evaluation substrate. The dielectric constant was calculated from the capacitance value at 10 kHz using an HP16451B electrode and an HP4284A precision LCR meter manufactured by Yokogawa-Hewlett-Packard Co., Ltd.

(Highlight etch method)
In the laminated body of this example, the damage evaluation of the first layer by reactive ions during the processing process using plasma (plasma CVD method) was performed using the highlight etching method. That is, after a silicon oxide film is laminated by the plasma CVD method on the second layer of the laminate formed on the substrate, the cross section obtained by cleaving this substrate is immersed in a hydrofluoric acid-containing aqueous solution for a predetermined time. Thereafter, the determination is made based on the presence or absence of the remaining first layer.

  More specifically, first, a carbon film as a protective film was laminated on the laminate by 50 nm by a sputtering method. Next, the laminated body on which this protective film was laminated was cleaved into a strip shape together with the 8-inch silicon substrate, and 10, 30, 60 at 25 ° C. in BHF-1100 (2% aqueous solution of ammonium fluoride) manufactured by Daikin Industries, Ltd. After dipping for 2 seconds, it was washed with ion-exchanged water for 60 seconds, and then dried in the atmosphere. Next, the shape of the cleaved surface was observed using a scanning electron microscope, and was classified into the following four stages depending on whether or not the first layer remained at each time. A: Remaining after 60 seconds, B: Remaining after 30 seconds, Δ: Remaining after 10 seconds, X: Disappearing after 10 seconds.

(1) Preparation of coating solution 1 In a quartz separable flask, 570 g of ethanol, 160 g of ion-exchanged water, and 30 g of 10% tetramethylammonium hydroxide aqueous solution were added and stirred uniformly. To this solution, a mixture of 136 g of methyltrimethoxysilane and 209 g of tetraethoxysilane was added. The reaction was carried out for 5 hours while keeping the solution at 60 ° C. To this solution was added 300 g of propylene glycol monopropyl ether, and then the solution was concentrated to 10% (in terms of complete hydrolysis condensate) using an evaporator at 50 ° C., and then 10% propylene glycol monopropyl ether of acetic acid. The solution was added to obtain a reaction solution 1 having a concentration of 3% (in terms of complete hydrolysis condensate). This solution was filtered through a Teflon (registered trademark) filter having a pore size of 0.2 μm to obtain a coating solution 1.

  The weight average molecular weight of the condensate obtained in this manner was 60,000. Also, the coating liquid 1 is applied onto an 8-inch silicon substrate by spin coating, dried at 80 ° C. for 1 minute, 200 ° C. for 1 minute, and further heated at 400 ° C. for 30 minutes under vacuum to obtain a cured film 1 (first film). 1 layer). The relative dielectric constant of the cured film 1 was 2.23.

(2) Preparation of coating solution 2 In a quartz separable flask, 243.30 g of methyltrimethoxysilane, 101.24 g of tetramethoxysilane, 123.64 g of triethoxysilane, and 0.02 g of tetrakis (acetylacetonate) titanium, After being dissolved in 254 g of dipropylene glycol dimethyl ether, the solution was uniformly stirred to stabilize the solution temperature at 50 ° C. Next, 278 g of ion-exchanged water was added to the solution over 1 hour. Then, after making it react at 50 degreeC for 3 hours, after adding 546 g of dipropylene glycol dimethyl ether and cooling a reaction liquid to room temperature, using a 50 degreeC evaporator, a solution will be 20% (completely hydrolyzed condensate conversion). Then, propylene glycol monopropyl ether was added to obtain a reaction solution 2 having a concentration of 0.5% (in terms of complete hydrolysis condensate). This solution was filtered through a Teflon (registered trademark) filter having a pore size of 0.2 μm to obtain a coating solution 2.

  Moreover, the cured film 2 (2nd layer) was produced by the method similar to the method of forming the above-mentioned cured film 1 using the coating liquid 2. FIG. The weight average molecular weight of the condensate thus obtained was 7,600, and the relative dielectric constant of the cured film 2 was 2.77.

(3) Preparation of Coating Solution 3 500 g of methanol, 228 g of ion-exchanged water, and 6.0 g of a 20% aqueous methylamine solution were placed in a quartz separable flask and stirred at 55 ° C. A mixture of 21.5 g of methyltriethoxysilane and 26.7 g of tetraethoxysilane was added to this solution at a constant rate over 1 hour. After this solution was further reacted at 55 ° C. for 1 hour, 79.5 g of a polysiloxane having a weight molecular weight of 5,000 having a repeating unit represented by the following structural formula (1) was added over 30 minutes.

  This solution was further reacted at 55 ° C. for 3 hours. Next, 56 g of a 20% maleic acid aqueous solution and 440 g of propylene glycol monopropyl ether are added to this solution, and then the solution is concentrated to 20% (in terms of complete hydrolysis condensate) using an evaporator at 50 ° C., and then Propylene glycol monopropyl ether was added to obtain a reaction solution 3 having a concentration of 0.5% (in terms of complete hydrolysis condensate). The reaction solution 3 was filtered through a Teflon (registered trademark) filter having a pore size of 0.2 μm to obtain a coating solution 3.

  Moreover, the cured film 3 (third layer) was produced by the same method as the method of forming the cured film 1 described above using the coating liquid 3. The weight average molecular weight of the condensate thus obtained was 20,000, and the relative dielectric constant of the cured film 3 was 2.67.

(4) Production of Laminate 1 On an 8-inch silicon substrate, the coating solution 1 produced in (1) above is applied by spin coating, dried at 80 ° C. for 1 minute, and 200 ° C. for 1 minute, and uncured. A first coating was formed. Further thereon, the coating solution 2 produced in the above (2) is applied by spin coating, heated in the atmosphere at 90 ° C. for 1 minute, then at 200 ° C. for 1 minute in nitrogen, and further at 30 ° C. in vacuum at 400 ° C. The second coating film (film thickness 10 nm) was laminated | stacked on the 1st coating film (film thickness 100 nm) by heating for minutes. Further thereon, a silicon oxide film having a thickness of 100 nm was formed by a plasma CVD method to obtain a laminate 1 composed of a first layer and a second layer.

  The plasma damage (damage caused by reactive ions in the plasma CVD process) in the first layer in the laminate 1 was evaluated by using the highlight etch method, and was evaluated as ◯.

  On an 8-inch silicon substrate, the coating solution 1 produced in (1) of Example 1 was applied by spin coating, dried at 80 ° C. for 1 minute, and 200 ° C. for 1 minute, and an uncured film having a thickness of 100 nm. A first coating was formed. Subsequently, the coating solution 3 produced in (3) of Example 1 was applied thereon by a spin coating method, heated in the atmosphere at 90 ° C. for 1 minute, and then heated at 200 ° C. for 1 minute in nitrogen to form a film thickness. A 10 nm uncured third coating was formed. Further thereon, the coating solution 2 produced in (2) of Example 1 was applied by spin coating. Thereby, the 3rd coating film (film thickness of 10 nm) and the 2nd coating film (film thickness of 10 nm) were laminated | stacked in order on the 1st coating film (film thickness of 100 nm). The laminate is then heated in the atmosphere at 90 ° C. for 1 minute, then at 200 ° C. for 1 minute under nitrogen, and further heated at 400 ° C. for 30 minutes under vacuum, whereby a third layer and a second layer are formed on the first layer. A laminate 300 in which the two layers were sequentially laminated was obtained. Further, a 100 nm-thick silicon oxide layer was formed thereon by a plasma CVD method. The structure of this laminated body 2 is shown in FIG. In the stacked body 2, a third layer 24 is formed between the first layer 20 and the second layer 22. A silicon oxide layer 60 is formed on the stacked body 2.

  When the plasma damage in the first layer 20 in the laminate 2 was evaluated using the highlight etching method, the evaluation was “◎”.

(Comparative example)
The coating liquid 1 produced in (1) of Example 1 above was applied onto an 8-inch silicon substrate by spin coating, dried at 80 ° C. for 1 minute, and then at 200 ° C. for 1 minute. A coating film was formed. Then, the 1st coating film (film thickness of 100 nm) was obtained by heating at 400 degreeC for 30 minutes under vacuum. On top of this, a silicon oxide layer having a thickness of 100 nm was formed by a plasma CVD method to obtain a laminate 3 composed of the first layer.

  It was x when the plasma damage in the 1st layer in the laminated body 3 was evaluated using the highlight etching method.

  As described above, according to the first and second embodiments and the comparative example, the second layer is formed on the first layer, so that the first process is performed during the plasma processing (plasma CVD method). It was confirmed that the damage applied to the layer could be reduced.

It is sectional drawing which shows typically the laminated body of one embodiment of this invention. It is sectional drawing which shows typically the wiring structure using the laminated body shown in FIG. FIG. 3 is a cross-sectional view schematically showing one manufacturing process of the wiring structure shown in FIG. 2. FIG. 3 is a cross-sectional view schematically showing one manufacturing process of the wiring structure shown in FIG. 2. FIG. 3 is a cross-sectional view schematically showing one manufacturing process of the wiring structure shown in FIG. 2. FIG. 3 is a cross-sectional view schematically showing one manufacturing process of the wiring structure shown in FIG. 2. It is sectional drawing which shows typically one manufacturing process of the wiring structure using the conventional laminated body. It is sectional drawing which shows typically the laminated body of Example 2 of this invention.

Explanation of symbols

2,100 Laminated body 10 Substrate 13 Reactive ion 20 First layer 20a Near exposed surface of first layer 22 Second layer 22a Near exposed surface of second layer 24 Third layer 32 Stopper layer 40 Organic system Insulating layer 42 Cap layer 60 Silicon oxide layer 70 Opening 72 First opening 74 Second opening 80 Barrier layer 82 Diffusion prevention layer 90 Conductive layer 90a Conductive material 92 Via layer 94 Wiring layer 110 Semiconductor substrate 400 Wiring structure R1, R2 resist layer

Claims (2)

(A) A coating solution containing an alkoxysilane hydrolysis condensate is applied onto a substrate and dried to form a first coating film;
(B) applying a coating solution containing an alkoxysilane hydrolysis condensate to form a third coating film; and (c) an application containing the alkoxysilane hydrolysis condensate above the third coating film. After the liquid is applied to form the second coating film, the first, second, and third coating films are heated and cured, whereby the first layer having a relative dielectric constant of 2.5 or less, A second layer having a relative dielectric constant exceeding 2.5, and between the first layer and the second layer, containing Si and at least selected from the group of O, C, N, and H Forming a laminate including a third layer containing one element;
A method for forming a laminate including: (A) A coating solution containing an alkoxysilane hydrolysis condensate is applied onto a substrate and dried to form a first coating film;
(B) A coating liquid containing an alkoxysilane hydrolysis condensate is applied to form a third coating film, and (c) a coating liquid containing an alkoxysilane hydrolysis condensate above the third coating film. Is applied to form a second coating film, and then the first, second, and third coating films are cured with an electron beam or an ultraviolet ray so that the first dielectric layer has a relative dielectric constant of 2.5 or less. And a second layer having a relative dielectric constant exceeding 2.5, and containing Si between the first layer and the second layer, and selected from the group of O, C, N, and H Forming a laminated body including a third layer containing at least one kind of element.

Images