JP2011026375A - Film-forming composition, insulating film, and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film-forming composition capable of forming an insulating film that is not susceptible to damages even in an etching process and maintains film characteristics, an insulating film formed from such a film-forming composition, and a semiconductor device equipped with such an insulating film. <P>SOLUTION: The film-forming composition includes a polymerizable compound having a polymerizable functional group, wherein the polymerizable compound has, in the molecule, a partial structure including a cage structure of an adamantane type and a polymerizable reactive group that contributes to polymerization reaction. The polymerizable reactive group has an aromatic ring and an ethynyl group or a vinyl group directly bonded to the aromatic ring. In the polymerizable compound, the number of carbon atoms derived from the aromatic ring is 15-38% relative to the number of carbon atoms of the whole polymerizable compound. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a film forming composition, an insulating film, and a semiconductor device.

  In recent years, in the field of electronic materials, as the integration, speed, and performance of semiconductor devices increase, the delay time due to the increase in inter-wire resistance and the increase in electric capacity of semiconductor integrated circuits has become a big problem. Yes. In order to reduce the delay time and increase the speed of the semiconductor device, it is necessary to use an insulating film having a low dielectric constant for the circuit.

  As such a low dielectric constant insulating film, an inorganic interlayer insulating film mainly composed of silicon such as HSQ (hydrogen-silsesquioxane) and MSQ (methyl-silsesquioxane) has been widely used.

  However, such an inorganic interlayer insulating film is easily damaged in an etching process for patterning the same.

  That is, in the etching process of the interlayer insulating film, C atoms are desorbed from the film due to the cleavage of the Si—C bond contained in the film. As a result, an unsaturated bond is generated in the Si atom, and since the Si atom is unstable in this state, for example, a Si—OH bond is formed by reacting with water molecules existing in the atmosphere. To do. Therefore, the dielectric constant of the interlayer insulating film is increased.

  In order to solve such problems, the characteristics of the interlayer insulating film can be recovered by a damage recovery process by the surface treatment of the interlayer insulating film or a damage component removal process on the surface of the interlayer insulating film using irradiation of an electron beam or the like. (For example, refer to Patent Documents 1 and 2). However, in such a method, if the miniaturization of the wiring insulated by the interlayer insulating film further proceeds, the damage received by the interlayer insulating film cannot be sufficiently recovered, or a process for recovering the characteristics of the interlayer insulating film There is a problem of increasing the number.

  Further, the use of an organic interlayer insulating film in place of the inorganic interlayer insulating film has been studied, but damage due to the etching process has not been sufficiently reduced.

JP 2007-266099 A JP 2007-317817 A

  An object of the present invention is to provide a film-forming composition that is capable of forming an insulating film that is not easily damaged by an etching process and maintains film characteristics, an insulating film formed using such a film-forming composition, and An object of the present invention is to provide a semiconductor device provided with such an insulating film.

Such an object is achieved by the present invention described in the following (1) to (15).
(1) A film-forming composition comprising a polymerizable compound having a polymerizable functional group,
The polymerizable compound has in its molecule a partial structure containing an adamantane-type cage structure and a polymerizable reactive group contributing to the polymerization reaction,
The polymerizable reactive group has an aromatic ring and an ethynyl group or a vinyl group directly bonded to the aromatic ring;
In the polymerizable compound, the number of carbons derived from the aromatic ring is 15% or more and 38% or less with respect to the number of carbons in the entire polymerizable compound.

  (2) For forming a film according to the above (1), which has two polymerizable reactive groups and has a structure in which the polymerizable reactive groups are symmetrically bonded around the partial structure. Composition.

  (3) The film forming composition according to (1) or (2), wherein the aromatic ring is directly bonded to the cage structure.

  (4) The polymerizable reactive group has two ethynyl groups or vinyl groups, and the one ethynyl group or the vinyl group is present at the meta position of the other ethynyl group or the vinyl group. The film forming composition as described in any one of (1) to (3) above.

  (5) The film-forming composition according to (4), wherein each of the two ethynyl groups or the vinyl group is present at the meta position of the site where the aromatic ring is bonded to the cage structure. .

  (6) The film-forming composition according to (4) or (5), further comprising a polymer obtained by partially polymerizing the polymerizable compound.

  (7) The film forming composition according to any one of (1) to (6), wherein the partial structure has an adamantane structure.

  (8) The film forming composition according to (7), wherein the adamantane structure has a methyl group as a substituent.

［式中、ｎは１〜５の整数を表す。］ (9) The film forming composition according to (8), wherein the polymerizable compound has a structure represented by the following formula (1).

[Wherein n represents an integer of 1 to 5. ]

  (10) The film forming composition according to any one of (1) to (6), wherein the partial structure has a diamantane structure.

  (11) The film-forming composition as described in any one of (1) to (10) above, which does not contain a pore-forming material having a function of forming pores in the film by thermal decomposition during film formation.

  (12) An insulating film formed by using the film forming composition according to any one of (1) to (11).

  (13) The change rate of the dielectric constant on the etched surface etched by a reactive ion etching method using a mixed gas of nitrogen and hydrogen or ammonia gas as a processing gas is 10% or less. Insulating film.

  (14) In the above (12) or (13), the etching rate at the time of etching is 10 Å / second or more and 90 Å / second or less by the reactive ion etching method using a mixed gas of nitrogen and hydrogen or ammonia gas. The insulating film as described.

  (15) A semiconductor device comprising the insulating film according to any one of (12) to (14).

  According to the present invention, an insulating film formed using a film-forming composition is less susceptible to damage even when an etching process is performed, and has a film characteristic without causing an increase in dielectric constant of the insulating film. It will be maintained. In addition, a highly reliable semiconductor device including the insulating film can be provided.

It is a longitudinal cross-sectional view which shows an example of the method of forming the interlayer insulation film patterned by the predetermined shape. It is a longitudinal cross-sectional view which shows typically an example of the semiconductor device of this invention.

Hereinafter, the present invention will be described in detail.
<Film forming composition>
First, the film forming composition of the present invention will be described.

  The film-forming composition of the present invention contains a polymerizable compound X having a polymerizable functional group. The polymerizable compound X has in its molecule a partial structure A including an adamantane cage structure and a polymerizable reactive group B that contributes to the polymerization reaction. , Having an ethynyl group or a vinyl group directly bonded to the aromatic ring, and in the polymerizable compound X, the number of carbons derived from the aromatic ring is the total number of carbons in the polymerizable compound X. It is characterized by being 15% or more and 38% or less with respect to the number. As a result, even if an etching process is performed using such a film-forming composition, an insulating film that is resistant to damage and that maintains its film characteristics without causing an increase in the dielectric constant of the insulating film can be ensured. Can be formed.

Hereinafter, the polymerizable compound X will be described.
In addition, since the ethynyl group or vinyl group which the polymerizable reactive group B has is a polymerizable group when the polymerizable compounds are polymerized and exhibits the same function, the polymerizable reactive group will be described below. A case where B has an ethynyl group will be described as an example.

[1] Polymerizable compound X
The polymerizable compound X has a partial structure A including an adamantane-type cage structure and a polymerizable reactive group B contributing to the polymerization reaction in the molecule.

Hereinafter, the partial structure A and the polymerizable reactive group B will be described.
[1.1] Partial structure A
The partial structure A possessed by the polymerizable compound X includes an adamantane cage structure. Thereby, the film (insulating film) formed using the film-forming composition can have a low density, and the dielectric constant of the formed film can be reduced. In addition, since the reactivity of the polymerizable compound X having the polymerizable reactive group B as described later in detail can be made appropriate, film formation on a member (for example, a semiconductor substrate) on which a film is to be formed When applying the composition for the film, the viscosity of the film-forming composition is surely suitable, and unintentional variations in thickness and characteristics at each part of the formed film can be suppressed, The strength of the finally formed film can be made excellent. Furthermore, the etching rate in the etching process for patterning the film (insulating film) formed using the film forming composition into a predetermined shape can be made relatively low.

Examples of the partial structure A possessed by the polymerizable compound X include adamantane, polyadamantane (eg, biadamantane, triadamantane, tetraadamantane, pentaadamantane, hexaadamantane, heptaadamantane, etc.), polyamantane (eg, diamantane, triamantane, Tetramantane, pentamantane, hexamantane, heptamantane, etc.), divalent groups such as compounds in which at least a part of hydrogen atoms constituting these compounds are substituted with alkyl groups or halogen atoms (two hydrogen atoms constituting the above compounds) A structure having two or more of these divalent groups (for example, a bi (diamantane) skeleton, a tri (diamantane) skeleton, a tetra (diamantane) skeleton, etc.) Things (Poly (Gia (Having a poly (triamantane) skeleton), such as a bi (triamantane) skeleton, a tri (triamantane) skeleton, and a tetra (triamantane) skeleton. An adamantane skeleton (or a polyadamantane skeleton) and a polyamantane skeleton, etc.) and the like. Hereinafter, a part of the example of the partial structure A is shown by a chemical structural formula, but the partial structure A is not limited to these. However, in the following formulas (A-1) to (A-7), R ¹ and R ² each independently represent a hydrogen atom, an alkyl group, or a halogen group, and l, m, and n are each independently 1 represents an integer of 1 or more.

  The partial structure A preferably has an adamantane structure. As a result, the dielectric constant of the film (insulating film) formed using the film-forming composition can be made particularly low, and in the etching process for patterning the film into a predetermined shape, the film has a high dielectric constant. It is possible to accurately suppress or prevent the rate from increasing. Further, the reactivity of the polymerizable compound X can be made more suitable, and when the composition for film formation on a member (for example, a semiconductor substrate) on which a film is to be formed is applied, The viscosity of the composition is more surely suitable, and it is possible to more effectively suppress unintentional variations in thickness and characteristics at each part of the formed film, and the film formed finally The strength can be made particularly excellent.

  The adamantane structure preferably has a methyl group as a substituent. Thereby, the dielectric constant of the film | membrane formed using the composition for film | membrane formation can be made especially low. Further, the reactivity of the polymerizable compound X can be made more suitable, and when the composition for film formation on a member (for example, a semiconductor substrate) on which a film is to be formed is applied, The viscosity of the composition is more surely suitable, and it is possible to more effectively suppress unintentional variations in thickness and characteristics at each part of the formed film, and the film formed finally The strength can be made particularly excellent. Furthermore, the etching rate in the etching process for patterning the film (insulating film) formed using the film forming composition into a desired shape can be made relatively low.

  From the above, as the partial structure A, those having a structure represented by the following formula (2) are particularly preferably used. In the following formula (2), n represents an integer of 1 or more.

  By selecting the structure having such a structure as the partial structure A, the film (insulating film) formed using the film forming composition exhibits the above-described effects more remarkably.

  In addition, it is preferable that the partial structure A having such a structure is a structure having symmetry itself. That is, in the above formula (2), n is preferably an even number. Thereby, the reactivity of the polymerizable compound X can be made more appropriate, and when the composition for forming a film on a member (for example, a semiconductor substrate) on which a film is to be formed is applied, the film formation is performed. The viscosity of the composition for use is more surely suitable, and it is possible to more effectively suppress unintentional variations in thickness and characteristics at each part of the formed film, and the film finally formed Can be made particularly excellent in strength.

  The partial structure A may have a diamantane structure. Thereby, the dielectric constant of the film | membrane formed using the composition for film formation can be made low. Further, the reactivity of the polymerizable compound X can be made more suitable, and when the composition for film formation on a member (for example, a semiconductor substrate) on which a film is to be formed is applied, The viscosity of the composition is more surely suitable, and it is possible to more effectively suppress unintentional variations in thickness and characteristics at each part of the formed film, and the film formed finally The strength can be made particularly excellent.

[1.2] Polymerizable reactive group B
In addition to the partial structure A as described above, the polymerizable compound X has a polymerizable reactive group B that contributes to the polymerization reaction.

  The polymerizable reactive group B has an aromatic ring and an ethynyl group directly bonded to the aromatic ring. The polymerizable compound X may have one polymerizable reactive group B, but has two, and these have a structure in which they are symmetrically bonded around the partial structure A. preferable. Thereby, the reactivity of the polymerizable compound X can be made appropriate, and when the film-forming composition is applied onto a member (for example, a semiconductor substrate) on which a film is to be formed, The viscosity of the composition is surely suitable, and it is possible to suppress unintentional variations in the thickness and characteristics of each part of the film to be formed, and the strength of the film finally formed is excellent. It can be.

  As described above, the polymerizable compound X has the two polymerizable reactive groups B together with the partial structure A, and furthermore, these have a specific arrangement, so that particularly excellent effects are exhibited.

  The aromatic ring constituting the polymerizable reactive group B is not particularly limited, and for example, a benzene ring, naphthalene ring, anthracene ring, naphthacene ring, phenanthrene ring, chrysene ring, pyrene ring, perylene ring, coronene ring, biphenyl ring, Hydrocarbon aromatic rings such as terphenyl ring and azulene ring, pyridine ring, furan ring, thiophene ring, pyrrole ring, oxazole ring, indole ring, purine ring, benzofuran ring, benzothiophene ring, carbazole ring, imidazole ring, Examples thereof include heterocyclic aromatic rings such as thiazole ring, pyrazole ring, isoxazole ring, isothiazole ring, quinoline ring, and terthienyl ring. Of these, a benzene ring is preferred as the aromatic ring. Thereby, application | coating of the composition for film formation on the member (for example, semiconductor substrate) which should form a film | membrane can be performed more easily. Moreover, the elasticity modulus of the film | membrane formed using the film forming composition can be made suitable, and the intensity | strength and heat resistance of the film | membrane formed, adhesiveness to the said member (semiconductor substrate etc.), etc. It can be made particularly excellent.

  The aromatic ring constituting the polymerizable reactive group B may be bonded to the cage structure constituting the partial structure A via at least one other atom, but the cage structure constituting the partial structure A It is preferable that it is directly bonded to. As a result, the reactivity of the polymerizable compound X can be made more suitable, and the film formation can be performed when a film forming composition is applied onto a member (for example, a semiconductor substrate) on which a film is to be formed. The viscosity of the composition for use is more surely suitable, and it is possible to more effectively suppress unintentional variations in thickness and characteristics at each part of the formed film, and the film finally formed Can be made particularly excellent in strength.

  The polymerizable reactive group B may have one ethynyl group, but has two ethynyl groups, and two ethynyl groups are directly bonded to the aromatic ring as described above. Is preferred. Thus, when the polymerizable reactive group B has two ethynyl groups as reaction sites, an initial reaction with respect to the polymerizable compound X is likely to occur. On the other hand, when one of the two ethynyl groups of the polymerizable reactive group B reacts (polymerization reaction), the electronic state of the aromatic ring changes, and the reactivity of the other ethynyl group rapidly increases. descend. For this reason, only one ethynyl group of the two ethynyl groups of the polymerizable reactive group B can be selectively reacted under relatively mild conditions. And since the polymerizable compound X preferably has two polymerizable reactive groups B in the molecule, one of the two polymerizable reactive groups B present in the molecule of the polymerizable compound X is Only the ethynyl group can be reacted selectively. In this case, for example, a polymer (chain-like prepolymer) in which a plurality of polymerizable compounds X are polymerized one-dimensionally by a reaction shown in the following formula (3). Polymer).

（式（３）中、Ａは部分構造Ａを示し、Ａｒは重合性反応基Ｂを構成する芳香環を示す。また、ｎは、２以上の整数を表す。）

(In formula (3), A represents the partial structure A, Ar represents an aromatic ring constituting the polymerizable reactive group B, and n represents an integer of 2 or more.)

  In the case where the polymerizable reactive group B has a vinyl group instead of an ethynyl group, a polymer in which a plurality of polymerizable compounds X are polymerized one-dimensionally by a reaction as shown in the following formula (3 ′) ( A chain prepolymer) is obtained.

（（３’）中、Ａは部分構造Ａを示し、Ａｒは重合性反応基Ｂを構成する芳香環を示す。また、ｎは、２以上の整数を表す。）

(In (3 ′), A represents the partial structure A, Ar represents an aromatic ring constituting the polymerizable reactive group B, and n represents an integer of 2 or more.)

  When the reaction as described above occurs, the polymerizable compound X reacts excessively during storage of the film-forming composition, and the film-forming composition becomes extremely viscous (for example, gelation). Can be reliably prevented, and the viscosity of the film-forming composition is surely suitable for applying the film-forming composition onto a member (for example, a semiconductor substrate) on which a film is to be formed. Can be. As a result, it is possible to reliably suppress the occurrence of unintentional variations in thickness and characteristics at each site of the formed film.

  On the other hand, since the polymer obtained by the reaction as described above (prepolymer obtained by partial polymerization reaction) has an unreacted ethynyl group, the firing conditions described in detail later ( Under the heating conditions on the semiconductor substrate, the remaining ethynyl groups can be reacted with certainty, and the film finally formed has a three-dimensionally cross-linked structure. As a result, the formed film is particularly excellent in heat resistance and the like.

  As described above, when each polymerizable reactive group B constituting the polymerizable compound X has two ethynyl groups, in the polymerizable reactive group B, one ethynyl group is a meta of the other ethynyl group. It is preferable that it exists in a position. Thereby, in the state in which one ethynyl group of the two ethynyl groups of the polymerizable reactive group B has reacted (polymerization reaction), the electronic effect of the aromatic ring or the like is more significantly exhibited, and the other ethynyl group The reactivity can be reduced more effectively, the reacted site becomes an appropriate steric hindrance, and the reactivity of the other ethynyl group (unreacted ethynyl group) can be more suitably controlled. . As a result, the reactivity of the two ethynyl groups of the polymerizable reactive group B (reactivity for the first stage reaction and reactivity for the second stage reaction) is made higher. In addition, it is possible to perform a baking step as will be described in detail later under more suitable conditions (conditions capable of forming a film with excellent productivity while preventing damage to the semiconductor substrate).

  In addition, when the polymerizable reactive group B has two ethynyl groups, it is preferable that both of the two ethynyl groups are present at the meta position where the aromatic ring is bonded to the cage structure. Thereby, in the state in which one ethynyl group of the two ethynyl groups of the polymerizable reactive group B has reacted (polymerization reaction), the electronic effect of the aromatic ring or the like is more significantly exhibited, and the other ethynyl group The reactivity can be reduced more effectively, and the reacted site and the partial structure A described above become an appropriate steric hindrance, and the reactivity of the other ethynyl group (unreacted ethynyl group) can be reduced. It can control more suitably. As a result, the reactivity of the two ethynyl groups of the polymerizable reactive group B (reactivity for the first stage reaction and reactivity for the second stage reaction) is made higher. In addition, it is possible to perform a baking step as will be described in detail later under more suitable conditions (conditions capable of forming a film with excellent productivity while preventing damage to the semiconductor substrate).

  The polymerizable compound X has the partial structure A and the polymerizable reactive group B as described above in the molecule. In the present invention, the number of carbons derived from the aromatic ring in the polymerizable compound X. However, it is 15% or more and 38% or less, and preferably 18% or more and 27% or less with respect to the total number of carbons of the polymerizable compound X. By making the number of carbons derived from the aromatic ring in the polymerizable compound X within such a range, the abundance ratio between the partial structure A and the polymerizable reactive group B becomes suitable, and the partial structure A as described above exists. The effect obtained by doing this and the effect obtained by the presence of the polymerizable reactive group B are synergistically obtained.

  In particular, in an etching process for patterning a film (insulating film) formed using the film-forming composition into a predetermined shape, it is possible to more accurately suppress or prevent the film from increasing in dielectric constant. And the film characteristics can be reliably maintained.

  In addition, it is thought that the increase in the dielectric constant of the film in the etching process is caused by, for example, physical effects and chemical effects as described below.

  The physical effect is that the etching gas accelerated by the plasma collides with the film at a high speed, resulting in unevenness on the film surface. As a result, moisture and the like are adsorbed on the film surface. It is thought that the characteristics change.

  In addition, the chemical effect is caused by the fact that the etching gas changes into ions and radicals due to plasma, and when these collide with the film, the chemical bonds in the film are broken and the structure of the film is changed. Therefore, it is considered that the characteristics of the film change.

  The increase in the dielectric constant of the film caused by such physical and chemical influences is suppressed or prevented more accurately by setting the number of carbons derived from the aromatic ring in the polymerizable compound X within the above-mentioned range. be able to.

  In addition, since the etching rate in this etching process is lowered and the etching rate on the surface of the insulating film is reduced, the etching is relatively gentle, and the physical and chemical effects described above are limited to the vicinity of the surface of the insulating film. The modified layer (etching damage layer) formed on the surface of the insulating film by etching can be prevented from being formed to the inside of the insulating film. Therefore, from this point of view, it is possible to accurately suppress or prevent the properties of the film from being altered or deteriorated.

  A polymerizable compound X that satisfies the above conditions, that is, a preferable one as the partial structure A and the polymerizable reactive group B is selected, and an aromatic ring-derived carbon in the polymerizable compound X is set to an appropriate number. Examples of the polymerizable compound X include those having a structure represented by the following formula (1). In the following formula (1), n represents an integer of 1 to 5.

  By selecting a compound having such a structure as the polymerizable compound X, a film (insulating film) formed using the film-forming composition exhibits the above-described effects more remarkably.

  In addition, in the polymerizable compound X having the structure represented by the above formula (1), those having two polymerizable reactive groups B are exemplified, but other polymerizable compounds having one polymerizable reactive group B are exemplified. Examples of X include those having a structure represented by the following formula (1 ′). In the following formula (1 ′), n represents an integer of 1 or 2.

  The polymerizable compound X may have a partial structure other than the partial structure A and the polymerizable reactive group B.

  The polymerizable compound X as described above has two polymerizable reactive groups B, and when the polymerizable reactive group B has two ethynyl groups, for example, it can be synthesized as follows. it can.

  That is, a compound A ′ corresponding to partial structure A (a compound in which two hydrogen atoms are bonded to A as a divalent group) is reacted with bromine, and a dibromo form of A ′ (two bromo groups are bonded to partial structure A) A compound obtained by reacting a dibromo form of A ′ with dibromobenzene to obtain a bis (dibromophenyl) form of A ′ (a compound in which two dibromophenyl groups are bonded to partial structure A), and A Reacting a dibromophenyl form of 'with trimethylsilylacetylene to obtain a bis (di (trimethylsilylethynyl) phenyl) form of A' (a compound in which two di (trimethylsilylethynyl) phenyl groups are bonded to partial structure A); And a step of hydrolyzing (detrimethylsilylating) the bis (di (trimethylsilylethynyl) phenyl) form of It can be obtained that the polymerizable compound X.

  In the case where the polymerizable reactive group B has two vinyl groups instead of two ethynyl groups, the polymerizable compound X can be synthesized, for example, as follows.

  That is, after synthesizing the polymerizable compound X having the two ethynyl groups described above, although not particularly limited, Lindlar reduction using hydrogen gas, Brich reduction using sodium and liquid ammonia, diimide reduction using diimide, etc. By carrying out, the target polymeric compound X can be obtained.

  The film-forming composition may contain the polymerizable compound X alone as described above. For example, the polymerizable compound X has two polymerizable reactive groups B and / or polymerizes. When the polymerizable reactive group B has two ethynyl groups, a polymer in which the polymerizable compound X is partially polymerized (a prepolymer in which only one polymerizable reactive group B of the two polymerizable reactive groups B is polymerized or reacted) And a prepolymer obtained by polymerization reaction of only one ethynyl group of the two ethynyl groups of the polymerizable reactive group B. When the film-forming composition contains a polymer (prepolymer) in which the polymerizable compound X is partially polymerized, the viscosity of the film-forming composition is more surely suitable, and each part of the film to be formed In addition, it is possible to more effectively suppress unintentional variations in thickness and characteristics of the film, and it is possible to make the strength of the finally formed film particularly excellent. In addition, the film forming composition is subjected to heat treatment prior to applying the film forming composition onto the member (for example, a semiconductor substrate) on which the film is to be formed, so that the film to be formed is relatively thick. Even if it is a thing, it can form suitably. In addition, when the film-forming composition contains a prepolymer of the polymerizable compound X, when a film is formed on a member (for example, a semiconductor substrate), the amount of heat applied on the member can be reduced. Damage to the member due to heating can be prevented more reliably. Such a film-forming composition containing a prepolymer of the polymerizable compound X can be suitably used as an insulating film varnish.

  A film-forming composition containing a polymer (prepolymer) in which the polymerizable compound X is partially polymerized can be suitably prepared by subjecting the polymerizable compound X to a heat treatment, for example. In this case, the heat treatment conditions are preferably heating temperature: 120 to 190 ° C., heating time: 3 to 11 hours, heating temperature: 140 to 180 ° C., heating time: 3 to 9 hours. preferable. Moreover, you may perform the heat processing with respect to the polymeric compound X combining different conditions. For example, for the polymerizable compound X, the first heat treatment performed under the conditions of heating temperature: 150 to 190 ° C., heating time: 1 to 6 hours, heating temperature: 120 to 160 ° C., heating time: 2 to 9 You may perform the 2nd heat processing performed on condition of time. In addition, it is preferable to perform the above heat processing in the state which melt | dissolved the polymeric compound X in the solvent. The synthesis of the prepolymer by the heat treatment as described above may be performed in a solvent as a constituent of the film-forming composition as described later, May be carried out in a solvent having a different composition. That is, after polymerizing the polymerizable compound X using a predetermined solvent to obtain a prepolymer, the solvent may be replaced with a solvent as a constituent of the target film-forming composition. Examples of the solvent (reaction solvent) that can be used for the synthesis of the polymer (prepolymer) in which the polymerizable compound X is partially polymerized include alcohols such as methanol, ethanol, isopropanol, 1-butanol, and 2-butanol. Solvent: Ketone solvents such as acetone, acetylacetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, cyclopentanone, 2-pentanone, 2-heptanone; ethyl acetate, propyl acetate, butyl acetate, pentyl acetate, propylene glycol monomethyl ether acetate, etc. Ester solvents; diisopropyl ether, dibutyl ether, diphenyl ether, tetrahydrofuran, anisole, 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, 1,4-dimethoxybenzene and the like Ter solvents: aromatic and aliphatic hydrocarbon solvents such as benzene, toluene, mesitylene, ethylbenzene, diethylbenzene, propylbenzene, heptane, hexane, n-octane; chloromethane, dichloromethane, chloroform, dichloroethane, carbon tetrachloride, etc. Halide-based solvents; amide-based solvents such as N-methylpyrrolidone and the like can be mentioned, and one or more selected from these can be used in combination.

  In addition, when the film-forming composition contains a prepolymer of the polymerizable compound X, the unreacted polymerizable compound X is removed by purification (the unreacted polymerizable compound X is not included as much as possible). Is preferred. Thereby, various characteristics, such as the intensity | strength of the film | membrane formed using the film forming composition, can be made more reliably excellent.

  The content of the polymerizable compound X in the film-forming composition and a polymer in which the polymerizable compound X is partially polymerized (for example, only one polymerizable reactive group B out of two polymerizable reactive groups B undergoes a polymerization reaction). The sum of the prepolymer and the content of the prepolymer obtained by polymerization reaction of only one ethynyl group of the two ethynyl groups of the polymerizable reactive group B is preferably 1.0 to 30 wt%.

[2] Solvent The film-forming composition includes the polymerizable compound X as described above, and further the polymerizable compound X has two polymerizable reactive groups B and / or two polymerizable reactive groups B. In the case of having an ethynyl group, a polymer in which the polymerizable compound X is partially polymerized (a prepolymer in which only one polymerizable reactive group B out of two polymerizable reactive groups B is polymerized or a polymerizable reactive group B is Any one of the two ethynyl groups having a prepolymer obtained by polymerization reaction of only one ethynyl group may be used, but usually a solvent for dissolving them is included.

  Examples of the solvent include N-methyl-2-pyrrolidone, γ-butyrolactone, N, N-dimethylacetamide, dimethyl sulfoxide, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, Propylene glycol monomethyl ether acetate, methyl lactate, ethyl lactate, butyl lactate, methyl-1,3-butylene glycol acetate, 1,3-butylene glycol-3-monomethyl ether, methyl pyruvate, ethyl pyruvate, methyl-3-methoxy Propionate, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, tetrahydro Orchids, anisole, mesitylene and the like, can be used singly or in combination of two or more selected from these. Of these, cyclopentanone and cyclohexanone are preferable as the solvent. Examples of the solvent constituting the film-forming composition include a solvent (reaction solvent) used for the synthesis of the polymerizable compound X and the above-described polymer (a prepolymer obtained by partially polymerizing the polymerizable compound X). May be included.

  Although the content rate of the solvent in the composition for film formation is not specifically limited, It is preferable that it is 70 to 99 wt%.

[3] Other components The film-forming composition may contain components other than those described above. Examples of such components include surfactants; coupling agents such as silane coupling agents; catalysts such as radical initiators and disulfides.

  The film-forming composition may contain a naphthoquinone diazide compound as a photosensitizer. Thereby, the composition for film formation can be used suitably for formation of the surface protection film which has photosensitivity.

  In the present invention, it is preferable that the film-forming composition does not contain a pore-forming material that foams due to thermal decomposability and forms pores in the formed film. Conventionally, a pore forming material has been used for the purpose of reducing the dielectric constant of the film. However, when such a pore forming material is used, the strength of the formed film is reduced, or at each part of the film. However, in the present invention, the polymerizable compound X has two polymerizable reactive groups B as well as the polymerizable compound X as described above. And / or when the polymerizable reactive group B has two ethynyl groups, a polymer obtained by partially polymerizing the polymerizable compound X (only one polymerizable reactive group B out of the two polymerizable reactive groups B) Can be formed without using a pore-forming material because it contains a prepolymer that has undergone a polymerization reaction, or a prepolymer in which only one ethynyl group has a polymerization reaction among the two ethynyl groups of the polymerizable reactive group B. The dielectric constant of the film to be sufficiently low Can. And generation | occurrence | production of the above problems can be prevented reliably by not containing a void | hole formation material.

  The film-forming composition as described above may be used for forming a film as it is, but the polymerizable compound X has two polymerizable reactive groups B and / or is polymerizable. When B has two ethynyl groups, it may be subjected to a heat treatment prior to application onto a member (for example, a semiconductor substrate) on which a film is to be formed. Thus, the film-forming composition can include a polymer (prepolymer) in which the polymerizable compound X is partially polymerized, and the viscosity of the film-forming composition is more surely suitable and formed. In addition, it is possible to more effectively suppress unintentional variations in thickness and characteristics of each portion of the film to be formed, and to make the finally formed film particularly excellent in strength. In addition, the film forming composition is subjected to heat treatment prior to applying the film forming composition onto the member (for example, a semiconductor substrate) on which the film is to be formed, so that the film to be formed is relatively thick. Even if it is a thing, it can form suitably. In addition, by applying a heat treatment to the film-forming composition prior to applying the film-forming composition onto a member (for example, a semiconductor substrate) on which a film is to be formed, the amount of heat applied on the member is reduced. Therefore, damage to the member due to heating can be prevented more reliably. When performing such heat treatment, the heat treatment conditions are preferably heating temperature: 120 to 190 ° C., heating time: 3 to 11 hours, heating temperature: 140 to 180 ° C., heating time: 3 to 9 hours. It is more preferable that Moreover, you may perform the above heat processing combining a different condition. For example, the 1st heat processing performed on the conditions of heating temperature: 150-190 degreeC, heating time: 1-6 hours, and the 2nd heat processing performed on the conditions of heating temperature: 120-160 degreeC and heating time: 2-9 hours And may be given.

<Insulating film>
The insulating film of the present invention is formed using the film forming composition as described above.

  FIG. 1 is a longitudinal sectional view showing an example of a method for forming an interlayer insulating film patterned in a predetermined shape. In the following description, the upper side in FIG. 1 is referred to as “upper” and the lower side is referred to as “lower”.

  In the insulating film of the present invention, for example, the film-forming composition as described above is applied onto a member such as a semiconductor substrate, and subjected to a treatment (baking treatment) such as heating or irradiation with active energy rays. Is formed.

  When applied on the member, the composition for forming a film has a case where the polymerizable compound X has two polymerizable reactive groups B and / or the polymerizable reactive group B has two ethynyl groups. The polymer compound X preferably contains a partially polymerized polymer (prepolymer). As a result, the viscosity of the film-forming composition applied on the member is more surely suitable, and it is possible to more effectively suppress unintentional variations in thickness and characteristics at each site of the formed film. In addition, the strength of the finally formed film can be made particularly excellent. Moreover, even if the film | membrane which should be formed is a comparatively thick thing, it can form suitably.

  By carrying out the baking treatment as described above, the unreacted ethynyl group of the polymerizable compound X or the prepolymer partially polymerized by the polymerizable compound X undergoes a polymerization reaction and has a structure in which a three-dimensional crosslinking reaction occurs. A film (insulating film) composed of a polymer (cured product) is obtained. A film (insulating film) composed of a polymer (cured product) having such a chemical structure is excellent in strength, heat resistance, and the like. Further, the film obtained as described above has a low dielectric constant. Further, the film obtained as described above is one in which unintentional variations in film thickness and characteristics at each part are suppressed. For these reasons, the above film can be suitably used as an insulating film constituting a semiconductor device.

  Examples of the method for applying the film-forming composition onto the member include a spin coating method using a spinner, a spray coating method using a spray coater, dipping, printing, and roll coating.

  Prior to the firing treatment, for example, a treatment (desolvation treatment) for removing the solvent from the film-forming composition applied on the member may be performed. Such solvent removal treatment can be performed, for example, by heat treatment, reduced pressure treatment, or the like.

  For example, the baking treatment is preferably performed under the conditions of treatment temperature: 200 to 450 degrees, treatment time: 1 to 60 minutes, and treatment temperature: 250 to 400 degrees, treatment time: 5 to 30 minutes. More preferred. In the baking step, heat treatments with different conditions may be combined.

  Further, when such an insulating film is applied to, for example, an interlayer insulating film that insulates wiring layers formed on a semiconductor substrate, vias (conductor posts) that electrically connect the wiring layers included in the semiconductor substrate are provided between the layers. It is formed so as to penetrate in the thickness direction of the insulating film. Therefore, the interlayer insulating film needs to have a predetermined shape patterned corresponding to the shape of the via (conductor post).

  The interlayer insulating film having a predetermined shape as described above can be formed as follows, for example.

  First, the semiconductor substrate 1 on which the SiN film 2 is formed is prepared, and the interlayer insulating film 3, the hard mask layer 4 and the photoresist layer 8 are formed in this order on the SiN film 2 (see FIG. 1A). .)

  The interlayer insulating film 3 is formed by the above-described method using the film forming composition of the present invention.

  Next, by exposing and developing the photoresist layer 8 using a photomask, a photoresist layer 8 patterned into a shape having an opening at a position where a via (conductor post) is formed is obtained (FIG. 1B). )reference.).

Next, the hard mask layer 4 is formed using the photoresist layer 8 as a mask by a reactive ion etching method using a gas generally used for patterning a hard mask material such as a fluorine-based gas such as CF ₄ as a processing gas. By etching, a hard mask layer 4 having a predetermined shape is formed (see FIG. 1C).

  Next, an interlayer insulating film is formed using the photoresist layer 8 as a mask by a reactive ion etching method using a mixed gas of nitrogen and hydrogen or an ammonia gas generally used for etching an organic film or the like as a processing gas. 3 is etched to form an interlayer insulating film 3 having a predetermined shape (see FIG. 1D).

  The interlayer insulating film 3 having a predetermined shape is obtained as described above. In the present invention, since the interlayer insulating film 3 is formed using the film forming composition of the present invention as described above, the interlayer insulating film 3 is formed. It is possible to more accurately suppress or prevent the film 3 from having a high dielectric constant, and to maintain the characteristics of the film with certainty.

  Specifically, on the etching surface of the interlayer insulating film 3 etched by a reactive ion etching method using a mixed gas of nitrogen and hydrogen or an ammonia gas generally used for etching an organic film or the like as a processing gas. The rate of change of dielectric constant is preferably reduced to 10% or less (excluding 0%), more preferably to 6.5% or less.

  In addition, the etching rate in this etching process is lowered and the etching rate on the surface of the insulating film is lowered, so that the etching is relatively gentle, and the formation of a modified layer (etching damage layer) by etching extends to the inside of the insulating film. Therefore, from this point of view, it is possible to accurately suppress or prevent the properties of the film from being altered or deteriorated.

  Specifically, a mixed gas of nitrogen and hydrogen (nitrogen flow rate: 7.5 sccm, hydrogen flow rate: 2.5 sccm) or ammonia gas (ammonia gas flow rate: 10.0 sccm) is used as the processing gas, and the frequency is 13.56 MHz. The etching rate when etching the interlayer insulating film 3 by the reactive ion etching method under the conditions of the pressure of 12.5 Pa and the output of 100 W is preferably 10 Å / second or more and 90 Å / second or less, preferably 10 Å / second. As mentioned above, it is more preferable that it is 50 tons / second or less. Thereby, it is possible to more appropriately suppress or prevent the property of the interlayer insulating film 3 from being altered or deteriorated.

  Furthermore, the insulating film is preferably in contact with a member (for example, a semiconductor substrate, an intermediate film, etc.) made of SiOC, SiCN, or SiO. Thereby, the adhesiveness etc. of the insulating film with respect to the member can be made particularly excellent.

  The thickness of the insulating film is not particularly limited, but when the insulating film is used as an interlayer insulating film for a semiconductor, it is preferably 0.01 to 20 μm, more preferably 0.02 to 10 μm, More preferably, it is 0.05-0.7 micrometer.

  In the case where the insulating film is used as a protective film for a semiconductor, the thickness of the insulating film is preferably 0.01 to 70 μm, and more preferably 0.05 to 50 μm.

<Semiconductor device>
Next, the semiconductor device of the present invention will be described based on a preferred embodiment.

FIG. 2 is a longitudinal sectional view schematically showing an example of the semiconductor device of the present invention.
As shown in FIG. 2, the semiconductor device 100 is provided on the semiconductor substrate 1 on which elements are formed, the SiN film 2 provided on the upper side of the semiconductor substrate 1 (upper side in FIG. 2), and the SiN film 2. A copper wiring layer 7 covered with an interlayer insulating film 3 and a barrier layer 6 is provided. The semiconductor device 100 of this embodiment includes an interlayer insulating film 3 as an insulating film of the present invention.

  A recess corresponding to the pattern to be wired is formed in the interlayer insulating film 3, and a copper wiring layer 7 is provided in the recess.

In addition, a modified treatment layer 5 is provided between the interlayer insulating film 3 and the copper wiring layer 7.
A hard mask layer 4 is formed on the upper side of the interlayer insulating film 3 (on the side surface opposite to the SiN film 2).

The semiconductor device 100 as described above can be manufactured, for example, as follows.
First, by using the method described in the above insulating film, an insulating film having a predetermined shape in which a penetrating wiring groove is formed at a predetermined position of the insulating film composed of the interlayer insulating film 3 and the hard mask layer 4 is formed. Form.

  Next, a modified treatment layer 5 is formed on the inner surface of the wiring groove by plasma treatment or the like, and further a barrier composed of Ta, Ti, TaN, TiN, WN or the like by a method such as PVD method or CVD method. Layer 6 is formed.

  Further, a copper wiring layer 7 to be a wiring layer is formed by an electrolytic plating method or the like, and then the copper wiring layer and the barrier metal layer other than the wiring portion are polished and removed and planarized by a CMP method. Obtainable.

  The interlayer insulating film 3 can be formed by the method described in the above description of the insulating film of the present invention. However, a dry film of a resin film is prepared in advance, and this is formed on the SiN of the semiconductor substrate 1. It can also be formed so as to be laminated on the film 2. More specifically, a resin film is formed on a member in advance using a film-forming composition and dried to obtain a dry film. The dry film is peeled off from the member, and the semiconductor substrate is separated from the semiconductor substrate. The interlayer insulating film 3 may be formed by stacking on one SiN film 2 and irradiating with heat and / or radiation.

  Since the semiconductor device of the present invention described above uses the interlayer insulating film (insulating film of the present invention) as described above, it has excellent dimensional accuracy and can sufficiently exhibit insulation, thereby providing excellent connection reliability. Yes.

  In addition, since the interlayer insulating film (the insulating film of the present invention) as described above has excellent adhesion to the wiring layer, the connection reliability of the semiconductor device can be further improved.

  In addition, since the interlayer insulating film (the insulating film of the present invention) as described above has an excellent elastic modulus, it can be suitably adapted to a process for forming a wiring of a semiconductor device (for example, a baking process).

  In addition, as described above, the interlayer insulating film (the insulating film of the present invention) can suppress or prevent etching damage during wiring processing, thereby suppressing or preventing changes in the characteristics of the insulating film during semiconductor device fabrication. be able to.

  In addition, since the interlayer insulating film (the insulating film of the present invention) as described above is excellent in dielectric characteristics, signal loss of the semiconductor device can be reduced.

  In addition, the interlayer insulating film (the insulating film of the present invention) as described above is excellent in dielectric characteristics, so that the wiring delay can be reduced.

  As mentioned above, although this invention was demonstrated based on suitable embodiment, this invention is not limited to these.

  For example, in the above description, the example in which the interlayer insulating film 3 as the insulating film of the present invention is formed on the SiN film 2 is representatively described. However, the position where the insulating film is formed is not limited to this.

  In the above-described embodiments, the insulating film provided with the interlayer insulating film is representatively described. However, the insulating film of the present invention may be applied to other than the interlayer insulating film. .

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example and a comparative example, this invention is not limited to this.

[1] Synthesis of polymerizable compound (Synthesis Example 1)
First, 1,3-dimethyladamantane was prepared, and carbon tetrachloride: 700 mL and bromine: 35 g (0.22 mol) were placed in a 4-neck 2000 mL flask equipped with a thermometer, a stirrer, and a reflux tube, and stirred. However, the prepared 1,3-dimethyladamantane: 32.9 g (0.2 mol) was added little by little. During the addition, the internal temperature was kept at 20-30 ° C.

After the addition was completed, the reaction was continued for another hour after the temperature did not rise.
Then, it poured into about 2000 mL of cold water, and the crude product was separated by filtration, washed with pure water, and dried.

The crude product was recrystallized from hot ethanol. The obtained recrystallized product was dried under reduced pressure to obtain 37.4 g of a product. IR analysis shows bromo group absorption at 690-515 cm ⁻¹ , and mass analysis molecular weight of 322 indicates that the product is 3,5-dimethyl-1,7-dibromoadamantane. It was.

  Next, 3,5-dimethyl-1,7-dibromoadamantane: 33.2 g (103.2 mmol) and 1,3-dibromobenzene: 1217 g (5161.6 mmol) obtained above were stirred in the flask, At 25 ° C. under dry nitrogen, 24.8 g (93.0 mmol) of aluminum (III) bromide was added in small portions. This was heated to 60 ° C. and stirred for 8 hours, and then returned to room temperature to obtain a reaction solution. The reaction solution was added to 700 ml of 5% aqueous hydrochloric acid solution and stirred. The aqueous layer was removed, and the organic layer was put into 2000 ml of acetone. The precipitate was filtered and washed with acetone: 1000 ml three times to obtain 57 g of 3,5-dimethyl-1,7-bis (3,5-dibromophenyl) adamantane. From the result of the molecular weight by mass spectrometry being 632, it was shown that the product was 3,5-dimethyl-1,7-bis (3,5-dibromophenyl) adamantane.

  Next, 3,5,5-dimethyl-1,7-bis (3,5-dibromophenyl) adamantane obtained above: 39.8 g (62.9 mmol), dichlorobistriphenylphosphine palladium: 3.53 g (5 0.0 mmol), triphenylphosphine: 6.60 g (25.2 mmol), copper (II) iodide: 4.79 g (25.2 mmol), and triethylamine: 750 ml were added to the flask and stirred. After raising the temperature to 75 ° C., 37.1 g (377.7 mmol) of trimethylsilylacetylene was slowly added. This was stirred at 75 ° C. for 7 hours and then heated to 120 ° C. to distill off triethylamine. Then, it returned to room temperature and added dichloromethane: 1000ml to the reaction liquid, and stirred for 20 minutes. The precipitate was removed by filtration, and 5% aqueous hydrochloric acid solution (1000 ml) was added to the filtrate for liquid separation. The organic layer was washed three times with 1000 ml of water, and then the solvent of the organic layer was removed under reduced pressure. The obtained compound was dissolved in 1500 ml of hexane. Insoluble matter was removed by filtration, and hexane in the filtrate was removed under reduced pressure. Acetone: 1000 ml was added thereto, and the precipitate was washed with acetone three times to obtain 3,5-dimethyl-1,7-bis (3,5-ditrimethylsilylethynylphenyl) adamantane: 36.1 g. . From the result of the molecular weight of 701 by mass spectrometry, it was shown that the product was 3,5-dimethyl-1,7-bis (3,5-ditrimethylsilylethynylphenyl) adamantane.

  Furthermore, 3,5-dimethyl-1,7-bis (3,5-ditrimethylsilylethynylphenyl) adamantane obtained above: 32.3 g (46.1 mmol) and potassium carbonate: 1.46 g (10.6 mmol) Were stirred in a mixed solvent of tetrahydrofuran: 600 ml and methanol: 300 ml under a nitrogen atmosphere at room temperature for 4 hours. This was poured into 10% aqueous hydrochloric acid solution: 1000 ml, the precipitate was filtered, and the resulting precipitate was washed with water: 1000 ml, further washed with acetone: 1000 ml, and then dried to obtain polymerizable compound X. 3,5-dimethyl-1,7-bis (3,5-diethynylphenyl) adamantane: 15.0 g was obtained.

  The appearance of the product, the results of mass spectrometry and elemental analysis are shown below. These data indicate that the compound obtained above is 3,5-dimethyl-1,7-bis (3,5-diethynylphenyl) adamantane.

Appearance: White solid MS (FD) (m / z): 413 (M +)
Elemental analysis: Theoretical value (/%) C; 93.16, H; 6.84, Measured value (/%) C; 93.11, H; 6.82

(Synthesis Examples 2 to 6)
The polymerizable compound X was prepared in the same manner as in Synthesis Example 1 except that tetramethylbiadamantane, hexamethyltriadamantane, octamethyltetraadamantane, decamethylpentaadamantane, dodecamethylhexaadamantane were prepared instead of dimethyladamantane. Got.

  The structural formula of the polymerizable compound X obtained in Synthesis Examples 1 to 6 is shown in the following formula (1). In the following formula (1), n represents an integer of 1 to 6, and the number of n corresponds to the number of each synthesis example.

  In addition, the external appearance of n = 2 polymerizable compound X (Synthesis example 2) in the said Formula (1), the result of a mass analysis, and an elemental analysis are shown.

Appearance: White solid MS (FD) (m / z): 574 (M +)
Elemental analysis: Theoretical value (/%) C; 91.93, H; 8.07, Actual value (/%) C; 91.87, H; 8.00

  Moreover, the external appearance of the said compound (1) n = 3 polymeric compound X (synthesis example 3), the result of a mass analysis, and an elemental analysis are shown.

Appearance: White solid MS (FD) (m / z): 737 (M +)
Elemental analysis: Theoretical value (/%) C; 91.25, H; 8.75, Actual value (/%) C; 91.21, H; 8.77

  The external appearance of the said compound (1) n = 4 polymeric compound X (synthesis example 4), the result of a mass analysis, and an elemental analysis are shown.

Appearance: White solid MS (FD) (m / z): 899 (M +)
Elemental analysis: Theoretical value (/%) C; 90.81, H; 9.19, Measured value (/%) C; 90.75, H; 9.16

  The external appearance of the said compound (1) n = 5 polymeric compound X (Synthesis example 5), the result of mass spectrometry, and an elemental analysis are shown.

Appearance: White solid MS (FD) (m / z): 1062 (M +)
Elemental analysis: theoretical value (/%) C; 90.51, H; 9.49, actual measurement value (/%) C; 90.49, H; 9.47

  Furthermore, the external appearance of the said compound (1) n = 6 polymeric compound X (synthesis example 6), the result of a mass analysis, and an elemental analysis are shown.

Appearance: White solid MS (FD) (m / z): 1223 (M +)
Elemental analysis: Theoretical value (/%) C; 90.28, H; 9.72, Actual value (/%) C; 90.26, H; 9.70

(Synthesis Example 7)
First, 4,9-dibromodiamantane was synthesized according to the synthesis method described in Journal of Organic Chemistry., 39, 2987-3003 (1974). Absorption of bromo group was observed at 690 to 515 cm ⁻¹ by IR analysis, and the result of molecular weight 346 by mass spectrometry indicated that the product was 4,9-dibromodiamantane.

  Next, in the synthesis of 3,5-dimethyl-1,7-bis (3,5-dibromophenyl) adamantane as a synthesis intermediate in Synthesis Example 1, in the synthesis of 3,5-dimethyl-1,7-dibromoadamantane, Instead, 4,9-bis (3,5-dibromophenyl) was reacted in the same manner as in Synthesis Example 1 except that 3,5.7 g (103.1 mmol) of 4,9-dibromodiamantane was used. ) Diamantane: 56 g was obtained. From the result of the molecular weight of 656 by mass spectrometry, it was shown that the product was 4,9-bis (3,5-dibromophenyl) diamantane.

  Next, in the synthesis of 3,5-dimethyl-1,7-bis (3,5-ditrimethylsilylethynylphenyl) adamantane as a synthesis intermediate in Synthesis Example 1, 3,5, -dimethyl-1,7- Synthesis Example 1 except that 41.2 g (62.8 mmol) of 4,9-bis (3,5-dibromophenyl) diamantane obtained above was used instead of bis (3,5-dibromophenyl) adamantane By reacting in the same manner as above, 3,5.5 g of 4,9-bis (3,5-ditrimethylsilylethynylphenyl) diamantane was obtained. From the result of the molecular weight measured by mass spectrometry of 725, it was shown that the product was 4,9-bis (3,5-ditrimethylsilylethynylphenyl) diamantane.

  Further, in the synthesis of 3,5-dimethyl-1,7-bis (3,5-diethynylphenyl) adamantane as the final product in Synthesis Example 1, 3,5-dimethyl-1,7-bis (3, Synthetic Example 1 except that instead of 5-ditrimethylsilylethynylphenyl) adamantane, 38.8 g (53.5 mmol) of 4,9-bis (3,5-ditrimethylsilylethynylphenyl) diamantane obtained above was used. By reacting in the same manner, 14.3 g of 4,9-bis (3,5-diethynylphenyl) diamantane as the polymerizable compound X was obtained.

  The appearance of the product, the results of mass spectrometry and elemental analysis are shown below. These data indicate that the compound obtained above is 4,9-bis (3,5-diethynylphenyl) diamantane.

Appearance: White solid MS (FD) (m / z): 436 (M +)
Elemental analysis: Theoretical value (/%) C; 93.54, H; 6.46, Actual value (/%) C; 93.46, H; 6.38

(Synthesis Examples 8 to 11)
A polymerizable compound X was obtained in the same manner as in Synthesis Example 7 except that dibromodi (diamantane), dibromotri (diamantane), dibromotetra (diamantane), and dibromopenta (diamantane) were prepared instead of dibromodiamantane. .

  The structural formula of the polymerizable compound X obtained in Synthesis Examples 7 to 11 is shown in the following formula (4). In following formula (4), n represents the integer of 1-5 and the number of n respond | corresponds to (number-6 of each synthesis example).

  In addition, the external appearance of the said Formula (4) n = 2 polymerizable compound X (Synthesis example 8), the result of a mass analysis, and an elemental analysis are shown.

Appearance: White solid MS (FD) (m / z): 622 (M +)
Elemental analysis: Theoretical value (/%) C; 92.56, H; 7.44, Measured value (/%) C; 92.53, H; 7.41

  Moreover, the external appearance of the said compound (4) n = 3 polymeric compound X (synthesis example 9), the result of mass spectrometry, and an elemental analysis are shown.

Appearance: White solid MS (FD) (m / z): 809 (M +)
Elemental analysis: Theoretical value (/%) C; 92.03, H; 7.97, Actual value (/%) C; 92.01, H; 7.94

  The external appearance of the said compound (4) n = 4 polymeric compound X (Synthesis example 10), the result of mass spectrometry, and an elemental analysis are shown.

Appearance: White solid MS (FD) (m / z): 995 (M +)
Elemental analysis: theoretical value (/%) C; 91.70, H; 8.30, actual value (/%) C; 91.67, H; 8.28

  Furthermore, the external appearance of the said compound (4) n = 5 polymeric compound X (Synthesis example 11), the result of a mass analysis, and an elemental analysis are shown.

Appearance: White solid MS (FD) (m / z): 1181 (M +)
Elemental analysis: Theoretical value (/%) C; 91.47, H; 8.53, measured value (/%) C; 91.42, H; 8.50

(Synthesis Example 12)
First, in a 4-neck 2000 mL flask equipped with a thermometer, a stirrer and a reflux tube, 3,5-dimethyl-1-bromoadamantane: 45.5 g (187.1 mmol) and 1,3-dibromobenzene: 1217 g ( 5161.6 mmol) and stirred, and at 25 ° C. under dry nitrogen, aluminum bromide (III): 24.8 g (93.0 mmol) was added in small portions. This was heated to 60 ° C. and stirred for 8 hours, and then returned to room temperature to obtain a reaction solution.

  Next, the reaction solution was added to 700 mL of 5% hydrochloric acid aqueous solution and stirred. The aqueous layer was removed, and the organic layer was poured into 2000 mL of acetone. The precipitate was filtered and washed 3 times with acetone: 1000 mL to obtain 3,5,5-dimethyl-1- (3,5-dibromophenyl) adamantane: 51.4 g. From the result of the molecular weight of 398 by mass spectrometry, it was shown that the product was 3,5, -dimethyl-1- (3,5-dibromophenyl) adamantane.

  Next, 3,5, -dimethyl-1- (3,5-dibromophenyl) adamantane obtained above: 47.1 g (118.4 mmol), dichlorobistriphenylphosphine palladium: 6.66 g (9.5 mmol) , Triphenylphosphine: 179.5 g (47.3 mmol), copper (II) iodide: 248.7 g (47.3 mmol), and triethylamine: 750 mL were added to the flask and stirred. After raising the temperature to 75 ° C., 34.9 g (355.2 mmol) of trimethylsilylacetylene was slowly added. This was stirred at 75 ° C. for 7 hours and then heated to 120 ° C. to distill off triethylamine. Then, it returned to room temperature and added dichloromethane: 1000mL to the reaction liquid, and stirred for 20 minutes. The precipitate was removed by filtration, and 5% hydrochloric acid aqueous solution: 1000 mL was added to the filtrate for liquid separation. The organic layer was washed 3 times with 1000 mL of water, and then the solvent of the organic layer was removed under reduced pressure. The obtained compound was dissolved in hexane: 1500 mL. Impurities were removed by filtration, and hexane in the filtrate was removed under reduced pressure. Acetone: 1000 mL was added thereto, and the precipitate was washed with acetone three times to obtain 37 g of 3,5-dimethyl-1- (3,5-ditrimethylsilylethynylphenyl) adamantane. The result of the molecular weight measured by mass spectrometry was 432, indicating that the product was 3,5-dimethyl-1- (3,5-ditrimethylsilylethynylphenyl) adamantane.

  Further, the 3,5-dimethyl-1- (3,5-ditrimethylsilylethynylphenyl) adamantane obtained above (36 g, 83.1 mmol) and potassium carbonate: 2.7 g (19.3 mmol) were mixed with tetrahydrofuran: 600 mL. In a mixed solvent of methanol: 300 mL, the mixture was stirred at room temperature for 4 hours under a nitrogen atmosphere. This was poured into 10% aqueous hydrochloric acid solution: 1000 mL, the precipitate was filtered, and the resulting precipitate was washed with water: 1000 mL, further washed with acetone: 1000 mL, and then dried to obtain 3 as a polymerizable compound. , 5-Dimethyl-1- (3,5-diethynylphenyl) adamantane: 19 g was obtained.

  The appearance of the product, the results of mass spectrometry and elemental analysis are shown below. These data indicate that the compound obtained above is 3,5-dimethyl-1- (3,5-diethynylphenyl) adamantane.

Appearance: White solid MS (FD) (m / z): 288 (M +)
Elemental analysis: Theoretical value (/%) C; 91.61, H; 8.39, Actual value (/%) C; 91.59, H; 8.37

(Synthesis Examples 13 and 14)
A polymerizable compound X was obtained in the same manner as in Synthesis Example 12 except that tetramethylbromobiadamantane and hexamethylbromotriadamantane were prepared instead of dimethylbromoadamantane.

  The structural formula of the polymerizable compound X obtained in Synthesis Examples 13 and 14 is shown in the following formula (1 ′). In the following formula (1 '), n represents an integer of 1 to 3, and the number of n corresponds to (No. 11 of each synthesis example).

  The appearance, mass analysis, and elemental analysis results of the polymerizable compound X (Synthesis Example 13) having the formula (1 ′) n = 2 are shown.

Appearance: White solid MS (FD) (m / z): 450 (M +)
Elemental analysis: theoretical value (/%) C; 90.61, H; 9.39, actual value (/%) C; 90.59, H; 9.36

  Further, the appearance, mass analysis, and elemental analysis results of the polymerizable compound X (Synthesis Example 14) of the above formula (1 ′) n = 3 are shown.

Appearance: White solid MS (FD) (m / z): 612 (M +)
Elemental analysis: Theoretical value (/%) C; 90.13, H; 9.87, Actual value (/%) C; 90.10, H; 9.86

(Synthesis Example 15)
First, 4-bromodiamantane: 50 g (187.1 mmol) and 1,3-dibromobenzene: 1217 g (5161.6 mmol) were placed in a 4-neck 2000 mL flask equipped with a thermometer, a stirrer and a reflux tube. Then, 24.8 g (93.0 mmol) of aluminum bromide (III) was added little by little at 25 ° C. under dry nitrogen. This was heated to 60 ° C. and stirred for 8 hours, and then returned to room temperature to obtain a reaction solution.

  Next, the reaction solution was added to 700 mL of 5% hydrochloric acid aqueous solution and stirred. The aqueous layer was removed, and the organic layer was poured into 2000 mL of acetone. The precipitate was filtered and washed 3 times with acetone: 1000 mL to obtain 56 g of 4- (3,5-dibromophenyl) diamantane. The result of the molecular weight of 422 by mass spectrometry showed that the product was 4- (3,5-dibromophenyl) diamantane.

  Next, 4- (3,5-dibromophenyl) diamantane obtained above: 50 g (118.4 mmol), dichlorobistriphenylphosphine palladium: 6.66 g (9.5 mmol), triphenylphosphine: 179.5 g ( 47.3 mmol), copper (II) iodide: 248.7 g (47.3 mmol), and triethylamine: 750 mL were added to the flask and stirred. After raising the temperature to 75 ° C., 34.9 g (355.2 mmol) of trimethylsilylacetylene was slowly added. This was stirred at 75 ° C. for 7 hours and then heated to 120 ° C. to distill off triethylamine. Then, it returned to room temperature and added dichloromethane: 1000mL to the reaction liquid, and stirred for 20 minutes. The precipitate was removed by filtration, and 5% hydrochloric acid aqueous solution: 1000 mL was added to the filtrate for liquid separation. The organic layer was washed 3 times with 1000 mL of water, and then the solvent of the organic layer was removed under reduced pressure. The obtained compound was dissolved in hexane: 1500 mL. Impurities were removed by filtration, and hexane in the filtrate was removed under reduced pressure. Acetone: 1000 mL was added thereto, and the precipitate was washed with acetone three times to obtain 41 g of 4- (3,5-ditrimethylsilylethynylphenyl) diamantane. From the result of the molecular weight measured by mass spectrometry being 456, it was shown that the product was 4- (3,5-ditrimethylsilylethynylphenyl) diamantane.

  Furthermore, 4- (3,5-ditrimethylsilylethynylphenyl) diamantane obtained above (40 g, 87.6 mmol) and potassium carbonate: 2.7 g (19.3 mmol) were mixed with tetrahydrofuran: 600 mL and methanol: 300 mL. The mixture was stirred for 4 hours at room temperature in a nitrogen atmosphere. This was poured into 10% aqueous hydrochloric acid solution: 1000 mL, the precipitate was filtered, and the resulting precipitate was washed with water: 1000 mL, further washed with acetone: 1000 mL, and then dried to obtain 4 as a polymerizable compound. -(3,5-diethynylphenyl) diamantane: 23 g was obtained.

  The appearance of the product, the results of mass spectrometry and elemental analysis are shown below. These data indicate that the compound obtained above is 4- (3,5-diethynylphenyl) diamantane.

Appearance: White solid MS (FD) (m / z): 312 (M +)
Elemental analysis: Theoretical value (/%) C; 92.26, H; 7.74, Actual value (/%) C; 92.12, H; 7.70

(Synthesis Examples 16 and 17)
A polymerizable compound X was obtained in the same manner as in Synthesis Example 15 except that bromobi (diamantane) and bromotri (diamantane) were prepared instead of bromodiamantane.

  The structural formula of the polymerizable compound X obtained in Synthesis Examples 15 to 17 is represented by the following formula (4 ′). In the following formula (4 ′), n represents an integer of 1 to 3, and the number of n corresponds to (number -14 in each synthesis example).

  The appearance, mass analysis, and elemental analysis results of the polymerizable compound X (Synthesis Example 16) having the formula (4 ′) n = 2 are shown.

Appearance: White solid MS (FD) (m / z): 498 (M +)
Elemental analysis: Theoretical value (/%) C; 91.51, H; 8.94, Actual value (/%) C; 91.49, H; 8.46

  Moreover, the external appearance of the said compound (4 ') n = 3 polymeric compound X (Synthesis example 17), the result of a mass analysis, and an elemental analysis are shown.

Appearance: White solid MS (FD) (m / z): 685 (M +)
Elemental analysis: Theoretical value (/%) C; 91.17, H; 8.83, Actual value (/%) C; 91.15, H; 8.80

(Synthesis Example 18)
In a 5-L eggplant flask, 14.4 g (34.9 mmol) of 3,5-dimethyl-1,7-bis (3,5-diethynylphenyl) adamantane obtained in Synthesis Example 1 and 67.4 g (522 mmol) of quinoline were obtained. 5% palladium-calcium carbonate 0.37 g (0.174 mmol), tetrahydrofuran (1000 mL) and a stirrer were added, and stirring was started at room temperature under a hydrogen stream. When 3.35 L (139 mmol) of hydrogen was consumed, nitrogen was introduced to stop the reaction. After filtering the reaction solution, the filtrate was distilled off under reduced pressure, and the resulting solid was purified by silica gel column chromatography to obtain 3,5-dimethyl-1,7-bis (3,5- Divinylphenyl) adamantane 18.1 g was obtained.

  The appearance of the product, the results of mass spectrometry and elemental analysis are shown below. These data indicate that the compound obtained above is 3,5-dimethyl-1,7-bis (3,5-divinylphenyl) adamantane.

Appearance: White solid MS (FD) (m / z): 420 (M +)
Elemental analysis: Theoretical value (/%) C; 91.37, H; 8.63, Actual value (/%) C; 91.35, H; 8.60

(Synthesis Examples 19 to 28)
The same as Synthesis Example 18 except that the polymerizable compound obtained in Synthesis Examples 2 to 11 was prepared instead of 3,5-dimethyl-1,7-bis (3,5-diethynylphenyl) adamantane. Thus, a polymerizable compound X was obtained.

  The structural formula of the polymerizable compound X obtained in Synthesis Examples 18 to 23 is shown in the following formula (5), and the structural formula of the polymerizable compound X obtained in Synthesis Examples 24 to 28 is shown in the following formula (6). . Moreover, in Formula (5), n represents the integer of 1-6, the number of n respond | corresponds to (number-17 of each synthesis example), and in Formula (6), n represents the integer of 1-5. , N corresponds to (number -23 in each synthesis example).

  In addition, the external appearance of the said Formula (5) n = 2 polymerizable compound X (Synthesis example 19), the result of a mass analysis, and an elemental analysis are shown.

Appearance: White solid MS (FD) (m / z): 582 (M +)
Elemental analysis: theoretical value (/%) C; 90.66, H; 9.34, actual measurement value (/%) C; 90.63, H; 9.31

  Moreover, the external appearance of the said compound (5) n = 3 polymeric compound X (synthesis example 20), the mass analysis, and the result of an elemental analysis are shown.

Appearance: White solid MS (FD) (m / z): 745 (M +)
Elemental analysis: theoretical value (/%) C; 90.26, H; 9.74, actual measurement value (/%) C; 90.24, H; 9.70

  The external appearance of the said compound (5) n = 4 polymeric compound X (synthesis example 21), the result of mass spectrometry, and an elemental analysis are shown.

Appearance: White solid MS (FD) (m / z): 907 (M +)
Elemental analysis: Theoretical value (/%) C; 90.00, H; 10.00, Actual value (/%) C; 89.96, H; 9.97

  The external appearance of the said compound (5) n = 5 polymeric compound X (synthesis example 22), the result of mass spectrometry, and an elemental analysis are shown.

Appearance: White solid MS (FD) (m / z): 1069 (M +)
Elemental analysis: Theoretical value (/%) C; 89.82, H; 10.18, Actual value (/%) C; 89.80, H; 10.14

  The external appearance of the polymeric compound X (synthesis example 23) of said Formula (5) n = 6, the result of a mass analysis, and an elemental analysis are shown.

Appearance: White solid
MS (FD) (m / z): 1231 (M +)
Elemental analysis: theoretical value (/%) C; 89.69, H; 10.31, actual value (/%) C; 89.66, H; 10.29

  The external appearance of the said compound (6) n = 1 polymeric compound X (synthesis example 24), the result of mass spectrometry, and an elemental analysis are shown.

Appearance: White solid
MS (FD) (m / z): 444 (M +)
Elemental analysis: Theoretical value (/%) C; 91.84, H; 8.16, measured value (/%) C; 91.81, H; 8.13
The external appearance of the said compound (6) n = 2 polymerizable compound X (synthesis example 25), the result of a mass analysis, and an elemental analysis are shown.
Appearance: White solid
MS (FD) (m / z): 630 (M +)
Elemental analysis: Theoretical value (/%) C; 91.37, H; 8.63, Actual value (/%) C; 91.32, H; 8.61

  The external appearance of the said Formula (6) n = 3 polymeric compound X (Synthesis example 26), the mass analysis, and the result of an elemental analysis are shown.

Appearance: White solid
MS (FD) (m / z): 817 (M +)
Elemental analysis: Theoretical value (/%) C; 91.12, H; 8.88, measured value (/%) C; 91.10, H; 8.84

  The external appearance of the said Formula (6) n = 4 polymeric compound X (Synthesis example 27), the result of mass spectrometry, and an elemental analysis are shown.

Appearance: White solid MS (FD) (m / z): 1003 (M +)
Elemental analysis: Theoretical value (/%) C; 90.96, H; 9.04, measured value (/%) C; 90.93, H; 9.01

  Furthermore, the external appearance of the said compound (6) n = 5 polymeric compound X (synthesis example 28), the result of a mass analysis, and an elemental analysis are shown.

Appearance: White solid MS (FD) (m / z): 1189 (M +)
Elemental analysis: Theoretical value (/%) C; 90.85, H; 9.15, Measured value (/%) C; 90.82, H; 9.11

[2] Preparation of film-forming composition (Example 1)
3,5-dimethyl-1,7-bis (3,5-diethynylphenyl) adamantane: 5 g as a polymerizable compound synthesized in Synthesis Example 1 was dissolved in 45 g of 1,3-dimethoxybenzene and dried. The reaction was carried out at 170 ° C. for 3 hours under nitrogen, and the reaction solution was once cooled to room temperature. When the molecular weight was measured by GPC, the number average molecular weight was 46,000. The reaction solution was heated again and reacted at 150 ° C. for 6 hours. The reaction solution was added dropwise to a 10-fold volume of a mixed solvent of methanol / tetrahydrofuran = 3/1, and the precipitate was collected and dried. A prepolymer was obtained (yield: 56%). 2 g of the obtained prepolymer was dissolved in 18 g of cyclopentanone and filtered through a filter to obtain a film forming composition as a varnish for an organic insulating film.

(Examples 2 to 5)
As the polymerizable compound, except that each synthesized in Synthesis Examples 2 to 5 was used, a polymerization reaction was performed in the same manner as in Example 1 to obtain a prepolymer, and further, using the prepolymer: 2 g, By performing the same treatment as described in Example 1, a film forming composition as a varnish for an organic insulating film was obtained.

(Comparative Example 1)
As the polymerizable compound, except that the compound synthesized in Synthesis Example 6 was used, a polymerization reaction was performed in the same manner as in Example 1 to obtain a prepolymer. Further, using the prepolymer: 2 g, the above example was used. By performing the same treatment as described in 1, a film forming composition as a varnish for an organic insulating film was obtained.

(Examples 6 to 9)
Except for using each of the compounds synthesized in Synthesis Examples 7 to 10 as the polymerizable compound, a polymerization reaction was performed in the same manner as in Example 1 to obtain a prepolymer, and further using the prepolymer: 2 g, By performing the same treatment as described in Example 1, a film forming composition as a varnish for an organic insulating film was obtained.

(Comparative Example 2)
As the polymerizable compound, except that the compound synthesized in Synthesis Example 11 was used, a polymerization reaction was carried out in the same manner as in Example 1 to obtain a prepolymer, and further using the prepolymer: 2 g, the above Example By performing the same treatment as described in 1, a film forming composition as a varnish for an organic insulating film was obtained.

(Examples 10 and 11)
As the polymerizable compound, except that those synthesized in Synthesis Examples 12 and 13 were respectively used, a polymerization reaction was performed in the same manner as in Example 1 to obtain a prepolymer, and further using the prepolymer: 2 g, By performing the same treatment as described in Example 1, a film forming composition as a varnish for an organic insulating film was obtained.

(Comparative Example 3)
As the polymerizable compound, except that the compound synthesized in Synthesis Example 14 was used, a polymerization reaction was performed in the same manner as in Example 1 to obtain a prepolymer. Further, using the prepolymer: 2 g, the above Example was used. By performing the same treatment as described in 1, a film forming composition as a varnish for an organic insulating film was obtained.

(Examples 12 and 13)
As the polymerizable compound, except that those synthesized in Synthesis Examples 15 and 16 were used, a polymerization reaction was performed in the same manner as in Example 1 to obtain a prepolymer, and further, using the prepolymer: 2 g, By performing the same treatment as described in Example 1, a film forming composition as a varnish for an organic insulating film was obtained.

(Comparative Example 4)
As the polymerizable compound, except that the compound synthesized in Synthesis Example 17 was used, a polymerization reaction was carried out in the same manner as in Example 1 to obtain a prepolymer, and further using the prepolymer: 2 g, the above Example By performing the same treatment as described in 1, a film forming composition as a varnish for an organic insulating film was obtained.

(Examples 14 to 18)
As a polymerizable compound, except that each synthesized in Synthesis Examples 18 to 22 was used, a polymerization reaction was performed in the same manner as in Example 1 to obtain a prepolymer, and further, using the prepolymer: 2 g, By performing the same treatment as described in Example 1, a film forming composition as a varnish for an organic insulating film was obtained.

(Comparative Example 5)
As the polymerizable compound, except that the compound synthesized in Synthesis Example 23 was used, a polymerization reaction was carried out in the same manner as in Example 1 to obtain a prepolymer, and further using the prepolymer: 2 g, the above Example By performing the same treatment as described in 1, a film forming composition as a varnish for an organic insulating film was obtained.

(Examples 19 to 22)
Except for using each of the compounds synthesized in Synthesis Examples 24 to 27 as the polymerizable compound, a polymerization reaction was performed in the same manner as in Example 1 to obtain a prepolymer, and further using the prepolymer: 2 g, By performing the same treatment as described in Example 1, a film forming composition as a varnish for an organic insulating film was obtained.

(Comparative Example 6)
As the polymerizable compound, except that the compound synthesized in Synthesis Example 28 was used, a polymerization reaction was carried out in the same manner as in Example 1 to obtain a prepolymer, and further using the prepolymer: 2 g, the above Example By performing the same treatment as described in 1, a film forming composition as a varnish for an organic insulating film was obtained.

  In addition, about the polymerizable compound contained in the film forming composition in each example and each comparative example, the number of carbons derived from the aromatic ring, the number of carbons derived from the polymerizable reactive group, the number of carbons derived from the partial structure, and the aromatic ring, respectively. Table 1 shows the ratio of carbon derived from the carbon source.

[3] Formation of insulating film (production of substrate with film)
Using the film forming composition as the organic insulating film varnish obtained in each of the above Examples and Comparative Examples, an insulating film was formed as follows.

  First, a film forming composition as a varnish for an organic insulating film was applied on a silicon wafer by a spin coater. At this time, the rotation speed and time of the spin coater were set so that the thickness of the insulating film after the heat treatment was 100 nm. For the insulating film for etching treatment, the rotation speed and time of the spin coater were set so that the thickness of the insulating film after the heat treatment was 1000 nm.

  Next, the silicon wafer provided with the coating film as described above was placed on a hot plate at 200 ° C. for 1 minute to remove the solvent (cyclopentanone) contained in the coating film.

  Thereafter, the silicon wafer provided with the dried coating film is subjected to a heat treatment (baking treatment) for 30 minutes in a nitrogen atmosphere in a 400 ° C. oven to cure the prepolymer constituting the coating film, Thus, a substrate with a film (substrate with an insulating film) was obtained.

  The etching treatment was performed under the conditions shown in the section [4.4] on the evaluation of the etching rate shown below.

[4] Evaluation of insulating film (substrate with film) Before and after performing reactive ion etching of the insulating film (substrate with film) according to each of the examples and comparative examples, dielectric constant, breakdown voltage, leakage current, and heat resistance Each characteristic of the property was evaluated by the following evaluation method, and the etching rate of the insulating film when performing reactive ion etching was measured by the following method.

[4.1] Dielectric Constant The dielectric constant was evaluated using an automatic mercury probe CV measuring device SSM495 manufactured by Nippon SSM Co., Ltd. Note that the change rate of the dielectric constant was obtained by a calculation formula of ((value after etching) − (value before etching) / (value before etching)) × 100.

[4.2] Breakdown voltage and leakage current The breakdown voltage and leakage current were evaluated using an automatic mercury probe CV measuring device SSM495 manufactured by Nippon SSM Co., Ltd., in the same manner as the dielectric constant.

The breakdown voltage is a voltage applied when a current of 1 × 10 ⁻² A flows, and a breakdown voltage, and the electric field strength (voltage (MV) applied when a current of 1 × 10 ⁻² A flows) is expressed as a film thickness (cm The value divided by), expressed in units of MV / cm). Note that the change rate of the breakdown voltage was obtained by a calculation formula of ((value before etching) − (value after etching) / (value before etching)) × 100.

The leakage current is defined as a leakage current that flows when the electric field intensity is 1 MV / cm, and the current density (A) that flows when the electric field intensity is 1 MV / cm is the mercury electrode area of the automatic mercury probe CV measuring device ( the value obtained by dividing the cm ²⁾ unit:. shown in A / cm ^2). The change in leakage current was determined by dividing the value after etching by the value before etching to determine how many times it changed before etching.

[4.3] Heat resistance Heat resistance was evaluated based on the thermal decomposition temperature. The obtained insulating film was measured using a TG / DTA measuring device (Seiko Instruments Co., Ltd., TG / DTA220) under a nitrogen gas flow of 200 mL / min. Under a temperature rising rate of 10 ° C./min. The temperature at which the weight loss reached 5% was defined as the thermal decomposition temperature. The rate of change in heat resistance was determined by the formula ((value before etching) − (value after etching) / (value before etching)) × 100, similarly to the rate of change in breakdown voltage.

[4.4] Etching rate In accordance with the formation of the insulating film described in [3] above, an insulating film was formed on a silicon wafer having a diameter of 76 mm for each of the examples and the comparative examples. The insulating film was etched using this. Then, the rate of change in film thickness before and after etching was determined using n & k Technology, Inc. This was measured using an n & k Analyzer 1500. The measurement point is set to (0,0) for the center coordinates, (0, -38) for the orientation flat part coordinates, and 9 linear coordinates from the coordinates (-38,0) to the coordinates (38,0) at equal intervals. . The value obtained by dividing the rate of change of the 9-point film thickness average value before and after etching by the reactive ion etching processing time was taken as the etching rate.

  Reactive ion etching uses L-201D-L manufactured by Anelva Co., Ltd., frequency 13.56 MHz, pressure 12.5 Pa, output 100 W, flow rate (nitrogen: 7.5 sccm, hydrogen: 2.5 sccm), The treatment time was 1 minute.

Moreover, about the weight average molecular weight (Mw), number average molecular weight (Mn), and dispersion ratio (Mw / Mn) of the prepolymer which comprises the varnish for organic insulating films (composition for film formation) of each Example and each comparative example Uses a gel permeation chromatograph (GPC) apparatus (HLC-8220GPC, manufactured by Tosoh Corporation), and as columns, TSKgel GMHXL (polystyrene conversion exclusion limit 4 × 10 ² (estimated)) × 2 and TSKgel G2000HXL (polystyrene conversion exclusion limit 1 × 10 ⁴ ) × 2 are connected in series, and measurement is performed using a refractometer (RI) or an ultraviolet / visible detector (UV (254 nm)) as a detector. Or it calculated | required by analyzing the result obtained by UV. The measurement conditions were mobile phase: tetrahydrofuran, temperature: 40 ° C., flow rate: 1.00 mL / min, sample concentration: 0.1 wt% tetrahydrofuran solution. These results are shown in Tables 2 to 4.

  As apparent from Tables 2 to 3, in each Example, the rate of change from before etching to after etching is suppressed low for each evaluation item of dielectric constant, breakdown voltage, leakage current, and thermal decomposition temperature, Such a tendency was particularly noticeable in the dielectric constant, and the rate of change was suppressed to 10% or less.

  Moreover, in each Example shown in Table 4, the etching rate at the time of etching an insulating film was suppressed to 10 to / min and 90 to / sec.

  On the other hand, in each comparative example, the number of carbons derived from the aromatic ring is less than 15% with respect to the total number of carbons in the polymerizable compound, and as a result, for each of the evaluation items, before the etching, The rate of change from etching to post-etching was large, and this tendency was particularly noticeable in the dielectric constant. Moreover, in each comparative example, it was guessed that the etching rate at the time of etching an insulating film was fast, and it became the cause of quality change and deterioration of an insulating film.

DESCRIPTION OF SYMBOLS 1 Semiconductor substrate 2 SiN film 3 Interlayer insulating film 4 Hard mask layer 5 Modification process layer 6 Barrier layer 7 Copper wiring layer 8 Photoresist layer 100 Semiconductor device

Claims (15)

A film-forming composition comprising a polymerizable compound having a polymerizable functional group,
The polymerizable compound has in its molecule a partial structure containing an adamantane-type cage structure and a polymerizable reactive group contributing to the polymerization reaction,
The polymerizable reactive group has an aromatic ring and an ethynyl group or a vinyl group directly bonded to the aromatic ring;
In the polymerizable compound, the number of carbons derived from the aromatic ring is 15% or more and 38% or less with respect to the number of carbons in the entire polymerizable compound.   2. The film forming composition according to claim 1, wherein the composition has two polymerizable reactive groups and has a structure in which the polymerizable reactive groups are symmetrically bonded around the partial structure.   The film forming composition according to claim 1, wherein the aromatic ring is directly bonded to the cage structure.   2. The polymerizable reactive group has two ethynyl groups or vinyl groups, and the one ethynyl group or vinyl group is present at the meta position of the other ethynyl group or vinyl group. 4. The film forming composition as described in any one of 3 to 3.   The film forming composition according to claim 4, wherein each of the two ethynyl groups or the vinyl group is present at a meta position of a site where the aromatic ring is bonded to the cage structure.   Furthermore, the composition for film formation of Claim 4 or 5 in which the said polymeric compound contains the polymer which superposed | polymerized partially.   The film forming composition according to claim 1, wherein the partial structure has an adamantane structure.   The film-forming composition according to claim 7, wherein the adamantane structure has a methyl group as a substituent. The film-forming composition according to claim 8, wherein the polymerizable compound has a structure represented by the following formula (1).

[Wherein n represents an integer of 1 to 5. ]   The film forming composition according to claim 1, wherein the partial structure has a diamantane structure.   The film-forming composition according to any one of claims 1 to 10, which does not contain a pore-forming material having a function of forming pores in the film by thermal decomposition during film formation.   An insulating film formed using the film forming composition according to claim 1.   The insulating film according to claim 12, wherein a change rate of a dielectric constant on an etched surface is 10% or less etched by a reactive ion etching method using a mixed gas of nitrogen and hydrogen or an ammonia gas as a processing gas.   The insulating film according to claim 12 or 13, wherein an etching rate at the time of etching is 10 以上 / second or more and 90 Å / second or less by a reactive ion etching method using a mixed gas of nitrogen and hydrogen or ammonia gas.   A semiconductor device comprising the insulating film according to claim 12.

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