JP2019001961A - Semiconductor device and method for manufacturing the same - Google Patents

Abstract

To provide a semiconductor device comprising an insulation element excellent in heat resistance and to provide a method for manufacturing the semiconductor device.SOLUTION: The semiconductor device includes a cured product of a silsesquioxane derivative in an insulation element in the semiconductor device. The silsesquioxane derivative is a silsesquioxane derivative having a hydrosilyl group, a carbon-carbon unsaturated bond and an alkoxysilyl group and the cured product thereof is a cured product produced by subjecting the silsesquioxane derivative produced by polycondensation of the alkoxysilyl group and/or hydrosilylation of the carbon-carbon unsaturated bond to heat treatment.SELECTED DRAWING: None

Description

  The present specification relates to a semiconductor device and a manufacturing method thereof.

  In addition to insulation, various insulating materials are used for semiconductor devices for the purpose of surface protection, sealing, wiring coating, heat dissipation, etc., and as insulating base materials such as printed boards. Conventionally, resin materials such as polyimide and epoxy resin have been used as insulating materials for semiconductor devices.

  In recent years, an insulating resin material having excellent heat resistance and dielectric strength for operating a power semiconductor device using GaN, SiC or the like as a semiconductor at a high temperature of 200 ° C. or more has been demanded. Further, such resin materials are also required to realize good filling processability, strength, insulation, etc. over a long period of time.

Silsesquioxane is composed of Si—O bonds in the main chain skeleton, and [R (SiO _3/2 )] (R represents an organic group), 1.5 oxygen atoms per silicon atom. It is a polysiloxane consisting only of structural units having atoms (hereinafter also referred to as T units). Silsesquioxane is considered to have intermediate properties based on inorganic silica (SiO ₂ ) and silicone resin (R ₂ SiO _2/2 ).

  On the other hand, a curable resin composition containing silsesquioxane is used as a sealing resin material for an optical semiconductor device in order to suppress coloring by light (Patent Documents 1 to 3). Moreover, the curable resin composition containing silsesquioxane may be used as an interlayer insulation film material (patent document 4).

International Publication No. 2011/145638 Pamphlet JP 2014-31522 A JP 2017-75216 A JP 2012-9796 A

  Until now, silsesquioxane has been used after being cured by radical reaction, hydrosilylation reaction or polycondensation reaction of alkoxysilyl group in the presence or absence of a catalyst at 100 ° C. to 200 ° C. It wasn't too much.

On the other hand, according to the present inventors, a cured product of a silsesquioxane derivative having at least a T unit, that is, [R (SiO _3/2 )], and having an alkoxysilyl group and a group capable of hydrosilylation reaction. For example, it had extremely excellent heat resistance even at a high temperature of 400 ° C. or higher, and had almost no change in weight. For this reason, the present inventors have not been able to envisage changes in the composition and properties, improvements in properties, and the like in the cured product of the silsesquioxane derivative.

  The present specification provides a semiconductor device including an insulating element having excellent heat resistance and a method for manufacturing the semiconductor device.

  As a result of various investigations on the heat treatment temperature of the silsesquioxane derivative, the present inventors surprisingly found that the silsesquioxane derivative was cured at a high temperature accompanied by partial crosslinking of the alkoxysilyl group and / or hydrosilyl group of the silsesquioxane derivative. In addition to good heat resistance and dielectric strength, it has been found that the product has a good coefficient of linear expansion. Combining such characteristics with heat resistance and withstand voltage is more suitable for an insulating element in a semiconductor device. According to this specification, the following means are provided based on this knowledge.

〔式中、Ａは、ヒドロシリル化反応可能な、炭素−炭素不飽和結合を有する炭素原子数２〜１０の有機基であり、Ｒ¹は炭素原子数１〜２０のアルキレン基、炭素原子数６〜２０の２価の芳香族基、及び炭素原子数３〜２０の２価の脂環族基から選択される少なくとも１種であり、ｎは０又は１であり、Ｒ²は水素原子、炭素原子数１〜１０のアルキル基、及び、ヒドロシリル化反応可能な、炭素−炭素不飽和結合を有する炭素原子数２〜１０の有機基（１分子中のＲ²は同一でも異なっていてもよい。）から選択される少なくとも１種であり、Ｒ³は水素原子、炭素原子数１〜１０のアルキル基、及び、ヒドロシリル化反応可能な、炭素−炭素不飽和結合を有する炭素原子数２〜１０の有機基から選択される少なくとも１種であり、Ｒ⁴は水素原子、炭素原子数１〜１０のアルキル基、及び、ヒドロシリル化反応可能な、炭素−炭素不飽和結合を有する炭素原子数２〜１０の有機基（１分子中のＲ⁴は同一でも異なっていてもよい。）から選択される少なくとも１種であり、Ｒ⁵は水素原子又は炭素原子数１〜６のアルキル基であり、ｖ及びｚは正の数であり、ｕ、ｗ、ｘ及びｙは０又は正の数であり、ｗ、ｘ及びｙのうち少なくとも１つは正の数であり、０≦ｕ／（ｖ＋ｗ＋ｘ＋ｙ）≦２であり、０≦ｘ／（ｖ＋ｗ）≦２であり、０≦ｙ／（ｖ＋ｗ）≦２であり、０≦ｚ／（ｖ＋ｗ＋ｘ＋ｙ）≦１である。但し、ｗ＝０のとき、Ｒ²、Ｒ³及びＲ⁴のいずれか１つはヒドロシリル化反応可能な、炭素−炭素不飽和結合を有する炭素原子数２〜１０の有機基である。〕
［６］前記硬化物の比誘電率は、３．０以下である、［１］〜［５］のいずれかに記載の半導体装置。
［７］前記硬化物の絶縁破壊電圧は、１０ｋＶ／ｍｍ以上である、［１］〜［６］のいずれかに記載の半導体装置。
［８］前記硬化物の線膨張係数は、１００ｐｐｍ／℃（１００℃〜３００℃）以下である、［１］〜［７］のいずれかに記載の半導体装置。
［９］前記硬化物の線熱膨張係数は、５０ｐｐｍ／℃（１００℃〜３００℃）以下である、［１］〜［８］のいずれかに記載の半導体装置。
［１０］前記硬化物の熱拡散係数は、０．１ｍｍ²／ｓ以上である、［１］〜［９］のいずれかに記載の半導体装置。
［１１］半導体装置の製造方法であって、
前記半導体装置の絶縁要素となる部位に、ヒドロシリル基、炭素−炭素不飽和結合及びアルコキシシリル基を有するシルセスキオキサン誘導体を含む絶縁性材料を供給する供給工程と、
前記シルセスキオキサン誘導体を硬化させる硬化工程と、
を備える、製造方法。
［１２］前記硬化工程は、前記アルコキシシリル基の重縮合及び／又は炭素−炭素不飽和結合のヒドロシリル化によって一次硬化させて一次硬化物を得る一次硬化工程と、前記一次硬化物をさらなる熱処理によって硬化させて二次硬化物を得る二次硬化工程と、を含む、［１１］に記載の製造方法。
［１３］前記二次硬化工程は、前記一次硬化物を４００℃以上の温度で熱処理する工程である、［１２］に記載の製造方法。
［１４］半導体装置の製造方法であって、
前記半導体装置の絶縁要素となる部位に、ヒドロシリル基、炭素−炭素不飽和結合及びアルコキシシリル基を有するシルセスキオキサン誘導体の硬化物であって、前記アルコキシシリル基の重縮合及び／又は、炭素−炭素不飽和結合のヒドロシリル化による前記シルセスキオキサン誘導体の一次硬化物を含む絶縁性材料を供給する供給工程と、
前記一次硬化物をさらなる熱処理によって硬化させて二次硬化物を得る二次硬化工程と、
を備える、製造方法。 [1] A semiconductor device,
The insulating element in the semiconductor device includes a cured product of a silsesquioxane derivative,
The silsesquioxane derivative includes a silsesquioxane derivative having a hydrosilyl group, a carbon-carbon unsaturated bond, and an alkoxysilyl group.
[2] The cured product is obtained by heat-treating a primary cured product of the silsesquioxane derivative by polycondensation of the alkoxysilyl group and / or hydrosilylation of a carbon-carbon unsaturated bond at a temperature of 400 ° C. or higher. The semiconductor device according to [1], which is a secondary cured product.
[3] The semiconductor device according to [2], wherein the temperature of the heat treatment is 500 ° C. or higher.
[4] The semiconductor device according to [2] or [3], wherein the temperature of the heat treatment is 800 ° C. or lower.
[5] The semiconductor device according to any one of [1] to [4], wherein the silsesquioxane derivative is represented by the following formula (1).

[In the formula, A is an organic group having 2 to 10 carbon atoms having a carbon-carbon unsaturated bond capable of hydrosilylation reaction, R ¹ is an alkylene group having 1 to 20 carbon atoms, and 6 carbon atoms. At least one selected from a divalent aromatic group having 20 to 20 carbon atoms and a divalent alicyclic group having 3 to 20 carbon atoms, n is 0 or 1, R ² is a hydrogen atom, carbon An alkyl group having 1 to 10 atoms and an organic group having 2 to 10 carbon atoms having a carbon-carbon unsaturated bond capable of hydrosilylation reaction (R ^{2 in} one molecule may be the same or different. R ³ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, and a carbon atom having 2 to 10 carbon atoms having a carbon-carbon unsaturated bond that can be hydrosilylated. At least one selected from organic groups, R ⁴ is hydrogen An atom, an alkyl group having 1 to 10 carbon atoms, and an organic group having 2 to 10 carbon atoms having a carbon-carbon unsaturated bond capable of hydrosilylation reaction (R ^{4 in} one molecule is the same or different. R ⁵ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, v and z are positive numbers, and u, w, x and y are 0 or a positive number, at least one of w, x and y is a positive number, 0 ≦ u / (v + w + x + y) ≦ 2, 0 ≦ x / (v + w) ≦ 2, and 0 ≦ y / (v + w) ≦ 2 and 0 ≦ z / (v + w + x + y) ≦ 1. However, when w = 0, any one of R ² , R ³ and R ⁴ is an organic group having 2 to 10 carbon atoms having a carbon-carbon unsaturated bond capable of hydrosilylation reaction. ]
[6] The semiconductor device according to any one of [1] to [5], wherein the relative permittivity of the cured product is 3.0 or less.
[7] The semiconductor device according to any one of [1] to [6], wherein the dielectric breakdown voltage of the cured product is 10 kV / mm or more.
[8] The semiconductor device according to any one of [1] to [7], wherein the cured product has a linear expansion coefficient of 100 ppm / ° C. (100 ° C. to 300 ° C.) or less.
[9] The semiconductor device according to any one of [1] to [8], wherein the cured product has a linear thermal expansion coefficient of 50 ppm / ° C. (100 ° C. to 300 ° C.) or less.
[10] The semiconductor device according to any one of [1] to [9], wherein the cured product has a thermal diffusion coefficient of 0.1 mm ² / s or more.
[11] A method of manufacturing a semiconductor device,
A supply step of supplying an insulating material containing a silsesquioxane derivative having a hydrosilyl group, a carbon-carbon unsaturated bond, and an alkoxysilyl group to a portion to be an insulating element of the semiconductor device;
A curing step of curing the silsesquioxane derivative;
A manufacturing method comprising:
[12] The curing step includes a primary curing step of obtaining a primary cured product by primary curing by polycondensation of the alkoxysilyl group and / or hydrosilylation of a carbon-carbon unsaturated bond, and further heating the primary cured product. A secondary curing step of obtaining a secondary cured product by curing, the production method according to [11].
[13] The production method according to [12], wherein the secondary curing step is a step of heat-treating the primary cured product at a temperature of 400 ° C. or higher.
[14] A method of manufacturing a semiconductor device,
A cured product of a silsesquioxane derivative having a hydrosilyl group, a carbon-carbon unsaturated bond and an alkoxysilyl group at a site serving as an insulating element of the semiconductor device, wherein the polycondensation of the alkoxysilyl group and / or carbon A supply step of supplying an insulating material containing a primary cured product of the silsesquioxane derivative by hydrosilylation of a carbon unsaturated bond;
A secondary curing step of curing the primary cured product by further heat treatment to obtain a secondary cured product;
A manufacturing method comprising:

  The present specification discloses a semiconductor device including an insulating element including a cured product of a silsesquioxane derivative and a manufacturing method thereof. According to the semiconductor device disclosed in this specification, the insulating element includes a cured product of a silsesquioxane derivative obtained by curing under predetermined conditions (hereinafter, also simply referred to as a “cured product”). For example, a semiconductor device that can ensure stable operation even in a high temperature range can be provided. The cured product is suitable as an insulating element in a semiconductor device because it has excellent heat resistance, good insulation, dielectric breakdown voltage, thermal expansion, thermal diffusivity, and the like.

  In addition, since the silsesquioxane derivative as a precursor of the cured product can be controlled to have a low viscosity without using a solvent, it is suitable for application to a semiconductor device. Moreover, since the silsesquioxane derivative has a low viscosity, various components such as a filler can be blended in a large amount as required. Therefore, the properties can be easily modified by these components.

  In addition, the cured product can be easily formed into a film or sheet form by casting or the like, and may be useful for application to a semiconductor device.

  In this specification, a carbon-carbon unsaturated bond means a carbon-carbon double bond or a carbon-carbon triple bond. In the present specification, the semiconductor device is not particularly limited, and examples thereof include a so-called power semiconductor device used for power conversion, power control, and the like. The elements and control circuits used in the power semiconductor device are not particularly limited, and include various known elements and control circuits. Further, the semiconductor device in this specification includes not only an element and a control circuit but also a semiconductor module including a unit for heat dissipation and cooling.

  In addition, the insulating element in the semiconductor device includes a component in the semiconductor device that is required to have insulating properties, typically, current interruption. Further, the insulating element may be any component that is required to ensure at least insulation in the semiconductor device, and is a component for the purpose of surface protection, sealing, element separation, wiring covering, heat dissipation, cooling, etc. Also good. Such insulating elements are not particularly limited, and examples thereof include various forms of insulating layers, insulating films, insulating films, and insulating substrates. As the insulating layer, for example, an insulating layer, an insulating sheet, an insulating base (substrate), a power semiconductor interposed between a semiconductor device such as a power semiconductor device and a heat radiating element or a cooling element added to the semiconductor device. Examples thereof include a sealing layer or a sealing sheet or film of a semiconductor device such as a device.

  Hereinafter, embodiments of a semiconductor device and a manufacturing method disclosed in this specification will be described in detail. For the convenience of explanation, silsesquioxane and the cured product will be described first.

(Silsesquioxane derivatives)
Silsesquioxane refers to polysiloxane [R (SiO _3/2 )] (also referred to as T unit, where R represents an organic group) whose main chain skeleton is composed of Si—O bonds. The silsesquioxane derivative in this specification is a compound containing a polysiloxane having at least a T unit characterizing silsesquioxane and having a hydrosilyl group, a carbon-carbon unsaturated bond, and an alkoxysilyl group. Hereinafter, such silsesquioxane derivatives will be described.

  Examples of the silsesquioxane having a hydrosilyl group, a carbon-carbon unsaturated bond, and an alkoxysilyl group include the structural units (1-1), (1-2), (1-3), (1-4), ( It can be represented by the following formula (1) comprising 1-5) and (1-6). U, v, w, x, y, and z in Formula (1) represent the molar amount of each structural unit. In the formula (1), u, v, w, x, y and z mean the average value of the ratio of the number of moles of each structural unit contained in one molecule of silsesquioxane. The formula of each structural unit also shows the molar amount of the structural unit.

  About each of structural unit (1-3)-(1-6) in Formula (1), it may be only 1 type and 2 or more types may be sufficient as it. Further, the condensed form of the structural units in the actual silsesquioxane derivative molecule does not necessarily follow the arrangement order of the formula (1).

  The silsesquioxane derivative has six structural units in the formula (1), that is, the structural unit (1-1), the structural unit (1-2), the structural unit (1-3), and the structural unit (1-4). The structural unit selected from the structural unit (1-5) and the structural unit (1-6) can be provided in combination so as to include a hydrosilyl group, a carbon-carbon unsaturated bond, and an alkoxysilyl group. That is, as the structural unit containing a hydrosilyl group, one or more structural units selected from the group consisting of the structural unit (1-2), the structural unit (1-4), and the structural unit (1-5) are provided. 1 or 2 or more types selected from the group consisting of the structural unit (1-3), the structural unit (1-4) and the structural unit (1-5) as a structural unit containing a carbon-carbon unsaturated bond Furthermore, at least the structural unit (1-6) containing an alkoxy group can be provided.

  For example, in Formula (1), v and z are positive numbers, u, w, x, and y are 0 or positive numbers, and at least one of w, x, and y is a positive number. .

<Structural unit (1-1)>
The number of structural units (1-1) in the silsesquioxane derivative represented by the formula (1) is not particularly limited.

<Structural unit (1-2)>
The structural unit (1-2) includes a hydrosilyl group. The number of structural units (1-2) in an actual molecule of the silsesquioxane derivative represented by the formula (1) is not particularly limited, but is preferably 5 or more and 100 or less, more preferably, for example. It is 6 or more and 80 or less, more preferably 7 or more and 60 or less, and particularly preferably 8 or more and 40 or less.

<Structural unit (1-3)>
A contained in the structural unit (1-3) represents an organic group having 2 to 10 carbon atoms having a carbon-carbon unsaturated bond capable of hydrosilylation reaction. That is, the organic group A is a functional group having a carbon-carbon double bond or a carbon-carbon triple bond capable of hydrosilylation reaction. Specific examples of the organic group A include, but are not limited to, for example, vinyl group, orthostyryl group, methacrylyl group, parastyryl group, acryloyl group, methacryloyl group, acryloxy group, methacryloxy group, 1-propenyl group, 1-butenyl group, 1-pentenyl group, 3-methyl-1-butenyl group, phenylethenyl group, ethynyl group, 1-propynyl group, 1-butynyl group, 1-pentynyl group, 3-methyl-1-butynyl group And a phenylbutynyl group.

  The silsesquioxane derivative represented by the formula (1) can contain two or more organic groups A as a whole, but in this case, all the organic groups A may be the same or different. Also good. Further, the plurality of organic groups A may be the same and may include different organic groups A. As the organic group A, a vinyl monomer having a small number of carbon atoms and a parastyryl group having good reactivity are preferable because a raw material monomer for forming the structural unit (1-3) is easily obtained. When the number of carbon atoms is small, the ratio of the inorganic portion of the present cured product can be increased and the heat resistance can be improved. In addition, an inorganic part means a SiO (siloxane) part.

In the structural unit (1-3), R ¹ represents an alkylene group having 1 to 20 carbon atoms (a divalent aliphatic group), a divalent aromatic group having 6 to 20 carbon atoms, or 3 to 3 carbon atoms. It represents at least one selected from 20 divalent alicyclic groups. Examples of the alkylene group having 1 to 20 carbon atoms include methylene group, ethylene group, n-propylene group, i-propylene group, n-butylene group, i-butylene group and the like. Examples of the divalent aromatic group having 6 to 20 carbon atoms include a phenylene group and a naphthylene group. Examples of the divalent alicyclic group having 3 to 20 carbon atoms include a divalent hydrocarbon group having a norbornene skeleton, a tricyclodecane skeleton, or an adamantane skeleton.

  In the structural unit (1-3), n is 0 or 1. Since the heat resistance of the cured film is higher when the number of carbon atoms is smaller, n = 0 is preferable.

  The number of structural units (1-3) in an actual molecule of the silsesquioxane derivative represented by the formula (1) is not particularly limited, but is preferably 0 or more and 40 or less, more preferably It is 0 or more and 30 or less, more preferably 0 or more and 20 or less, and particularly preferably 0 or more and 10 or less.

<Structural unit (1-4)>
In the structural unit (1-4), R ² represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, and an organic compound having 2 to 10 carbon atoms having a carbon-carbon unsaturated bond that can be hydrosilylated. It represents at least one selected from the group.

The alkyl group for R ² may be either an aliphatic group or an alicyclic group, and may be either linear or branched. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group. The organic group having 2 to 10 carbon atoms having a carbon-carbon unsaturated bond capable of hydrosilylation reaction in R ² is synonymous with the organic group A described above, and various aspects included in the organic group A already described. Is included.

Several R < ² > contained in a structural unit (1-4) may be the same kind, and may differ. R ² is preferably a hydrogen atom, a methyl group, or a vinyl group since the number of carbon atoms is small and the cured product is excellent in heat resistance.

  The number of structural units (1-4) in an actual molecule of the silsesquioxane derivative represented by the formula (1) is not particularly limited, but is preferably 0 or more and 40 or less, more preferably It is 0 or more and 30 or less, more preferably 0 or more and 20 or less, and particularly preferably 0 or more and 10 or less.

<Structural unit (1-5)>
In the structural unit (1-5), R ³ represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, and an organic compound having 2 to 10 carbon atoms having a carbon-carbon unsaturated bond that can be hydrosilylated. It represents at least one selected from the group.

The alkyl group in R ³ has the same meaning as R ² in the structural unit (1-4), and can include the various specific examples described above. The organic group having 2 to 10 carbon atoms having a carbon-carbon unsaturated bond capable of hydrosilylation reaction in R ³ is synonymous with the organic group A described above, and various aspects included in the organic group A already described. Is included. R ³ is preferably a hydrogen atom or a vinyl group because it can participate in the curing reaction of the silsesquioxane derivative, has a small number of carbon atoms, and the cured product has excellent heat resistance.

In the structural unit (1-5), R ⁴ represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, and an organic compound having 2 to 10 carbon atoms having a carbon-carbon unsaturated bond that can be hydrosilylated. It is at least one selected from the group. The alkyl group in R ⁴ has the same meaning as R ² in the structural unit (1-4), and can include the various specific examples described above. Further, the organic group having 2 to 10 carbon atoms having a carbon-carbon unsaturated bond capable of hydrosilylation reaction in R ⁴ is synonymous with the organic group A described above, and is included in the organic group A already described. Various embodiments are included. The plurality of R ⁴ contained in the structural unit (1-5) may be the same or different. R ⁴ is preferably a hydrogen atom, a methyl group or a vinyl group because of good reactivity and a small number of carbon atoms, and a methyl group is particularly preferred from the viewpoint of easy handling of raw material monomers and intermediate products.

  The number of structural units (1-5) in the actual molecule of the silsesquioxane derivative represented by the formula (1) is not particularly limited, but is preferably 0.1 or more and 50 or less, for example. Preferably they are 0.5 or more and 30 or less, More preferably, they are 1 or more and 20 or less, Most preferably, they are 2 or more and 10 or less.

<Structural unit (1-6)>
In the structural unit (1-6), R ⁵ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and may be either an aliphatic group or an alicyclic group, and may be any of linear or branched But you can. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group.

  The structural unit (1-6) is an alkoxy group produced by substitution of an alkoxy group, which is a hydrolyzable group contained in a raw material monomer described later, or an alcohol contained in a reaction solvent, with the hydrolyzable group of the raw material monomer. A group which remains in the molecule without hydrolysis and polycondensation, or a hydroxyl group which remains in the molecule without hydrolysis and polycondensation after hydrolysis.

  The number of structural units (1-6) in an actual molecule of the silsesquioxane derivative represented by the formula (1) is not particularly limited, but is preferably 0.1 or more and 20 or less, for example. Preferably they are 0.2 or more and 10 or less, More preferably, they are 0.3 or more and 8 or less, Most preferably, they are 0.5 or more and 5 or less.

  The relationship between u, v, w, x, and y, which is the molar amount of each structural unit in formula (1), is that the silsesquioxane derivative represented by formula (1) is hydrosilyl group, carbon-carbon unsaturated. Although not particularly limited as long as it has a bond and an alkoxysilyl group, for example, 0 ≦ u / (v + w + x + y) ≦ 2, more preferably 0 ≦ u / (v + w + x + y) ≦ 1.5, and more preferably 0. ≦ u / (v + w + x + y) ≦ 1, particularly preferably 0 ≦ u / (v + w + x + y) ≦ 0.8. When u / (v + w + x + y) is too large, the silsesquioxane derivative tends to gel or storage stability tends to decrease.

  In the formula (1), the relationship between v, w and x is not particularly limited. For example, 0 ≦ x / (v + w) ≦ 2, more preferably 0 ≦ x / (v + w) ≦ 1, More preferably, 0 ≦ x / (v + w) ≦ 0.7, and particularly preferably 0 ≦ x / (v + w) ≦ 0.5. When x / (v + w) is too large, the heat resistance of the obtained cured product tends to decrease when heated in the absence of a catalyst.

  In the formula (1), the relationship between v, w and y is not particularly limited. For example, 0 ≦ y / (v + w) ≦ 2, more preferably 0 ≦ y / (v + w) ≦ 1, More preferably, 0 ≦ y / (v + w) ≦ 0.7, and particularly preferably 0 ≦ y / (v + w) ≦ 0.4. If y / (v + w) is too large, the heat resistance of the obtained cured product tends to decrease when heated in the absence of a catalyst.

  In the formula (1), the relationship between v, w, x, y and z is not particularly limited, but for example, 0.01 ≦ z / (v + w + x + y) ≦ 1, more preferably 0.02 ≦. z / (v + w + x + y) ≦ 0.5, particularly preferably 0.03 ≦ z / (v + w + x + y) ≦ 0.3. If z / (v + w + x + y) is too small, the curability tends to decrease when heated in the absence of a catalyst. On the other hand, if z / (v + w + x + y) is too large, the storage stability of the silsesquioxane derivative tends to decrease, or when heated, the heat resistance of the resulting cured product tends to decrease.

In formula (1), when w = 0, at least one of R ² , R ³ and R ⁴ is an organic group having 2 to 10 carbon atoms having a carbon-carbon unsaturated bond capable of hydrosilylation reaction. . The silsesquioxane derivative in which v, w, x, y and z in the above formula (1) satisfy the above conditions is a low-viscosity, excellent handling workability, uniform, smooth and excellent heat resistance. Can be formed.

<Molecular weight, etc.>
The number average molecular weight of the silsesquioxane derivative is preferably in the range of 300 to 30,000. Such silsesquioxane itself has a low viscosity, is easily soluble in an organic solvent, is easy to handle the viscosity of the solution, and is excellent in storage stability. The number average molecular weight is more preferably 500 to 15,000, still more preferably 700 to 10,000, and particularly preferably 1,000 to 5,000. The number average molecular weight can be determined by GPC (gel permeation chromatograph), for example, using polystyrene as a standard substance under the measurement conditions in [Example] described later.

  The silsesquioxane derivative is liquid and has a viscosity at 25 ° C. of preferably 30,000 mPa · s or less, more preferably 10,000 mPa · s or less, and 5,000 mPa · s or less. Is more preferably 3,000 mPa · s or less, particularly preferably 1,000 mPa · s or less. However, the lower limit of the viscosity is usually 1 mPa · s.

<Method for producing silsesquioxane derivative>
The silsesquioxane derivative can be produced by a known method. A method for producing a silsesquioxane derivative is disclosed in International Publication Nos. 2005/01007, 2009/0666608, 2013/0999909, JP2011-052170, and JP2013-147659. Are disclosed in detail as a method for producing polysiloxane.

  The silsesquioxane derivative can be produced, for example, by the following method. That is, the method for producing a silsesquioxane derivative includes a condensation step of performing a hydrolysis / polycondensation reaction of a raw material monomer that gives the structural unit in the above formula (1) by condensation in an appropriate reaction solvent. it can. In this condensation step, a silicon compound having four siloxane bond-forming groups (hereinafter referred to as “Q monomer”), which forms the structural unit (1-1), the structural units (1-2) and (1- 3) a silicon compound having three siloxane bond-forming groups (hereinafter referred to as “T monomer”) and a silicon compound having two siloxane bond-forming groups forming a structural unit (1-4) ( Hereinafter, a “D monomer”) and a silicon compound (hereinafter referred to as “M monomer”) that forms the structural unit (1-5) having one siloxane bond-forming group can be used.

  In this specification, specifically, a T monomer that forms the structural unit (1-2), a T monomer that forms the structural unit (1-3), a D monomer that forms the structural unit (1-4), And at least one of M monomers forming the structural unit (1-5). It is preferable to provide a distillation step of distilling off the reaction solvent, by-products, residual monomers, water, etc. in the reaction solution after subjecting the raw material monomer to hydrolysis / polycondensation reaction in the presence of the reaction solvent.

  The siloxane bond-forming group contained in the Q monomer, T monomer, D monomer or M monomer, which are raw material monomers, is a hydroxyl group or a hydrolyzable group. Among these, examples of the hydrolyzable group include a halogeno group and an alkoxy group. At least one of the Q monomer, T monomer, D monomer and M monomer preferably has a hydrolyzable group. In the condensation step, hydrolyzability is good, and since no acid is by-produced, the hydrolyzable group is preferably an alkoxy group, more preferably an alkoxy group having 1 to 3 carbon atoms.

  In the condensation step, the siloxane bond-forming group of the Q monomer, T monomer, or D monomer corresponding to each structural unit is preferably an alkoxy group, and the siloxane bond-forming group contained in the M monomer is preferably an alkoxy group or a siloxy group. . Moreover, the monomer corresponding to each structural unit may be used independently, and can be used in combination of 2 or more type.

  Examples of the Q monomer that gives the structural unit (1-1) include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane. Examples of the T monomer that gives the structural unit (1-2) include trimethoxysilane, triethoxysilane, tripropoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltriisopropoxysilane, and ethyltrimethoxy. Examples include silane, ethyltriethoxysilane, propyltriethoxysilane, butyltrimethoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, and trichlorosilane. Examples of the T monomer that gives the structural unit (1-3) include trimethoxyvinylsilane, triethoxyvinylsilane, (p-styryl) trimethoxysilane, (p-styryl) triethoxysilane, and (3-methacryloyloxypropyl) trimethoxysilane. , (3-methacryloyloxypropyl) triethoxysilane, (3-acryloyloxypropyl) trimethoxysilane, (3-acryloyloxypropyl) triethoxysilane, and the like. As the D monomer giving the structural unit (1-4), dimethoxydimethylsilane, dimethoxydiethylsilane, diethoxydimethylsilane, diethoxydiethylsilane, dipropoxydimethylsilane, dipropoxydiethylsilane, dimethoxybenzylmethylsilane, diethoxybenzyl Examples include methylsilane, dichlorodimethylsilane, dimethoxymethylsilane, dimethoxymethylvinylsilane, diethoxymethylsilane, and diethoxymethylvinylsilane. Examples of the M monomer that gives the structural unit (1-5) include hexaethyldisiloxane, hexapropyldisiloxane, 1,1, in addition to hexamethyldisiloxane that gives two structural units (1-5) by hydrolysis. 3,3-tetramethyldisiloxane, 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, methoxydimethylsilane, ethoxydimethylsilane, methoxydimethylvinylsilane, ethoxydimethylvinylsilane, methoxytrimethylsilane, ethoxytrimethyl Silane, methoxydimethylphenylsilane, ethoxydimethylphenylsilane, chlorodimethylsilane, chlorodimethylvinylsilane, chlorotrimethylsilane, dimethylsilanol, dimethylvinylsilanol, trimethylsilanol, triethylsilanol Tripropyl silanol, tributyl silanol and the like. Examples of the organic compound that gives the structural unit (1-6) include alcohols such as 2-propanol, 2-butanol, methanol, and ethanol.

  In the condensation step, alcohol can be used as a reaction solvent. Alcohol is a narrowly defined alcohol represented by the general formula R—OH, and is a compound having no functional group in addition to the alcoholic hydroxyl group. Specific examples include, but are not limited to, methanol, ethanol, n-propyl alcohol, isopropyl alcohol, 2-butanol, 2-pentanol, 3-pentanol, 2-methyl-2-butanol, 3- Methyl-2-butanol, cyclopentanol, 2-hexanol, 3-hexanol, 2-methyl-2-pentanol, 3-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-3 -Pentanol, 2-ethyl-2-butanol, 2,3-dimethyl-2-butanol, cyclohexanol and the like can be exemplified. Among these, isopropyl alcohol, 2-butanol, 2-pentanol, 3-pentanol, 3-methyl-2-butanol, cyclopentanol, 2-hexanol, 3-hexanol, 3-methyl-2-pentanol, Secondary alcohols such as cyclohexanol are used. In the condensation step, these alcohols can be used alone or in combination of two or more. More preferred alcohols are compounds that can dissolve water at the concentration required in the condensation step. The alcohol having such a property is a compound having a water solubility of 10 g or more per 100 g of alcohol at 20 ° C.

  The alcohol used in the condensation step is a silsesquioxane derivative produced by using 0.5% by mass or more based on the total amount of all the reaction solvents, including additional input during the hydrolysis / polycondensation reaction. Can be prevented from gelling. A preferable usage amount is 1% by mass or more and 60% by mass or less, and more preferably 3% by mass or more and 40% by mass or less.

  The reaction solvent used in the condensation step may be only alcohol, or may be a mixed solvent with at least one sub-solvent. The sub-solvent may be either a polar solvent or a nonpolar solvent, or a combination of both. Preferred as the polar solvent is a secondary or tertiary alcohol having 3 or 7 to 10 carbon atoms, a diol having 2 to 20 carbon atoms, or the like. In addition, when using primary alcohol as a subsolvent, it is preferable to use the usage-amount to 5 mass% or less of the whole reaction solvent. A preferred polar solvent is 2-propanol which can be obtained industrially at low cost. By using 2-propanol and the alcohol according to the present invention in combination, the alcohol according to the present invention has a concentration of water necessary for the hydrolysis step. Even if it is a thing which cannot melt | dissolve, a required amount of water can be melt | dissolved with a polar solvent, and the effect of this invention can be acquired. The amount of the preferred polar solvent is 20 parts by mass or less, more preferably 1 to 20 parts by mass, and particularly preferably 3 to 10 parts by mass with respect to 1 part by mass of the alcohol according to the present invention.

  Non-polar solvents include, but are not limited to, aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, chlorinated hydrocarbons, alcohols, ethers, amides, ketones, esters, cellosolves, and the like. . Among these, aliphatic hydrocarbons, alicyclic hydrocarbons, and aromatic hydrocarbons are preferable. Such a nonpolar solvent is not particularly limited, but for example, n-hexane, isohexane, cyclohexane, heptane, toluene, xylene, methylene chloride, and the like are preferable because they azeotrope with water. After the condensation step, water can be efficiently distilled off from the reaction mixture containing the silsesquioxane derivative when the reaction solvent is removed by distillation. As the nonpolar solvent, xylene which is an aromatic hydrocarbon is particularly preferable since it has a relatively high boiling point. The usage-amount of a nonpolar solvent is 50 mass parts or less with respect to 1 mass part of alcohol which concerns on this invention, More preferably, it is 1-30 mass parts, Most preferably, it is 5-20 mass parts.

  The hydrolysis / polycondensation reaction in the condensation step proceeds in the presence of water. The amount of water used for hydrolyzing the hydrolyzable group contained in the raw material monomer is preferably 0.5 to 5 times mol, more preferably 1 to 2 times mol for the hydrolyzable group. Further, the hydrolysis / polycondensation reaction of the raw material monomer may be performed without a catalyst or may be performed using a catalyst. In the case of using a catalyst, usually an acid catalyst exemplified by inorganic acids such as sulfuric acid, nitric acid, hydrochloric acid and phosphoric acid; and organic acids such as formic acid, acetic acid, oxalic acid and paratoluenesulfonic acid is preferably used. The amount of the acid catalyst used is preferably an amount corresponding to 0.01 to 20 mol%, and an amount corresponding to 0.1 to 10 mol%, based on the total amount of silicon atoms contained in the raw material monomer. More preferably.

  The completion of the hydrolysis / polycondensation reaction in the condensation step can be appropriately detected by the methods described in the various publications described above. In the condensation step for producing the silsesquioxane derivative, an auxiliary agent can be added to the reaction system. Examples thereof include an antifoaming agent that suppresses foaming of the reaction solution, a scale control agent that prevents the scale from adhering to the reaction tank and the stirring shaft, a polymerization inhibitor, and a hydrosilylation reaction inhibitor. Although the usage-amount of these adjuvants is arbitrary, Preferably it is about 1-100 mass% with respect to the silsesquioxane derivative density | concentration in a reaction mixture.

  After the condensation step in the production of the silsesquioxane derivative, it is provided with a distillation step for distilling off the reaction solvent and by-products, residual monomers, water, etc. contained in the reaction liquid obtained from the condensation step, thereby producing the produced silsesquioxane. The stability of the oxane derivative can be improved.

<Hardened product of silsesquioxane derivative and curing method of silsesquioxane derivative>
The silsesquioxane derivative is a hydrosilylation of an alkoxysilyl group in the silsesquioxane derivative and / or a hydrosilylation reaction between the hydrosilyl group in the silsesquioxane and a carbon-carbon unsaturated group capable of hydrosilylation. By the reaction, a cured product (main cured product) of the silsesquioxane derivative having a crosslinked structure can be obtained. The production of the cured product may be catalyst-free or may involve the use of a catalyst for the hydrosilylation reaction. The catalyst that can be used for curing will be described in detail later.

  Although this hardened | cured material is not specifically limited, For example, at the temperature of 400 degreeC or more, hydrolysis and polycondensation of the alkoxysilyl group in a silsesquioxane derivative, and / or the hydrosilyl group in a silsesquioxane derivative, and A crosslinked structure by a hydrosilylation reaction with a carbon-carbon unsaturated group capable of hydrosilylation reaction can be provided. This is because if it is lower than 400 ° C., unreacted alkoxysilyl groups and hydrosilyl groups tend to remain. Further, by providing such a crosslinked structure obtained in a heat treatment at a temperature of 400 ° C. or higher, in addition to heat resistance, it is possible to obtain a thermal expansion coefficient and a thermal diffusion coefficient suitable as an insulating element of a semiconductor device.

  From the viewpoint of heat resistance, thermal expansion coefficient and thermal diffusion coefficient, the heat treatment temperature is also, for example, 450 ° C. or higher, for example, 500 ° C. or higher, for example, 550 ° C. or higher, and for example, 600 ° C. or higher. . When the temperature is 550 ° C. or higher, the linear expansion coefficient and the thermal diffusion coefficient become more suitable as an insulating element of a semiconductor device. When it is 550 ° C. or higher, the linear expansion coefficient and the thermal diffusion coefficient are further improved. Also, the upper limit of the heat treatment temperature is not particularly limited, but is, for example, 800 ° C. or lower, for example, 750 ° C. or lower, for example, 700 ° C. or lower, and for example, 650 ° C. or lower. For example, it is 600 degrees C or less. Further, the preferable range of the heat treatment temperature can be a range appropriately combining the lower limit temperature and the upper limit temperature, for example, 500 ° C. or higher and 800 ° C. or lower, and for example, 550 ° C. or higher and 800 ° C. or lower. For example, 600 ° C. or more and 800 ° C. or less, and for example, 550 ° C. or more and 600 ° C. or less. In the range from 550 ° C. to 600 ° C., the linear expansion coefficient is good. In addition, the temperature increase rate to this heat processing temperature is not specifically limited, For example, it can be set as 5-20 degreeC / min. Further, the holding time at the heat treatment temperature is not particularly limited, but is, for example, 0.1 to 10 hours, and preferably 0.5 to 5 hours.

  The cured product may be a cured product obtained by causing a crosslinking reaction based on an alkoxysilyl group and / or a hydrosilyl group in the presence or absence of a catalyst with respect to the silsesquioxane derivative. The cured product may be obtained by a curing process in which the silsesquioxane derivative is heat-treated at the above temperature all at once, but from the viewpoint of obtaining the cured product that exhibits stable characteristics, as shown below, It can also be obtained by carrying out a two-stage curing process including a primary curing process and a secondary curing process.

<Primary cured product and primary curing method of silsesquioxane derivative>
The silsesquioxane derivative can obtain a primary cured product based on crosslinking by an alkoxysilyl group and / or a hydrosilyl group and a carbon-carbon unsaturated bond. Such a cured product is in a state in which at least partial cross-linking by hydrosilyl groups occurs.

  In order to obtain a primary cured product of the silsesquioxane derivative, a step of heating the silsesquioxane derivative at a temperature of 50 ° C. or more and 200 ° C. or less in the absence of the hydrosilylation reaction catalyst can be performed. For example, you may implement the process heated at the temperature of 100 to 150 degreeC. In the temperature range of 50 ° C. or more and 200 ° C. or less, the curing temperature may be constant or a combination of temperature increase and / or temperature decrease. At a temperature of 50 ° C. or higher and 200 ° C. or lower, a crosslinked structure is formed by partially curing mainly by a reaction of an alkoxysilyl group (hydrolysis / polycondensation reaction). Moreover, a part of the crosslinked structure may be formed by a hydrosilylation reaction. It can be mentioned that the thermal stability of the secondary cured product is further improved by the primary curing.

  The primary curing step for obtaining the primary cured product can be performed, for example, by the following method. That is, a coating film of a silsesquioxane derivative is formed on the surface of a base material having a desired shape such as a plate-like base material or a granular base material, and heated to a temperature of 50 ° C. or higher and 200 ° C. or lower as described above. The silsesquioxane derivative coating film is partially cured. This eliminates the fluidity of the silsesquioxane derivative and, if necessary, processes this laminate (a plate-like substrate or a granular substrate provided with a primary cured film of the silsesquioxane derivative) to obtain a desired Or shape.

  In the case of primary curing at a temperature of 50 ° C. or higher and 200 ° C. or lower, the previous curing time is usually 0.1 to 10 hours, preferably 0.5 to 5 hours.

  In addition, in order to obtain a primary cured product having a hydrosilyl group crosslinked, a catalyst for hydrosilylation reaction can also be used. In this case, it can be cured at a relatively low temperature (for example, room temperature to 200 ° C., preferably 50 ° C. to 150 ° C.). However, the cured product of the silsesquioxane derivative obtained tends to have an unreacted alkoxysilyl group. When using the catalyst for hydrosilylation reaction, the curing time is usually 0.05 to 24 hours, preferably 0.1 to 5 hours.

Examples of the catalyst for hydrosilylation reaction include simple substances of Group 8 to Group 10 metals such as cobalt, nickel, ruthenium, rhodium, palladium, iridium, and platinum, organometallic complexes, metal salts, and metal oxides. Usually, a platinum-based catalyst is used. Platinum catalysts include cis-PtCl ₂ (PhCN) ₂ , platinum carbon, platinum complex coordinated with 1,3-divinyltetramethyldisiloxane (Pt (dvs)), platinum vinylmethyl cyclic siloxane complex, platinum carbonyl Vinylmethyl cyclic siloxane complex, tris (dibenzylideneacetone) diplatinum, chloroplatinic acid, bis (ethylene) tetrachlorodiplatinum, cyclooctadienedichloroplatinum, bis (cyclooctadiene) platinum, bis (dimethylphenylphosphine) dichloroplatinum And tetrakis (triphenylphosphine) platinum. Of these, platinum complexes (Pt (dvs)) coordinated with 1,3-divinyltetramethyldisiloxane, platinum vinylmethyl cyclic siloxane complexes, and platinum carbonyl / vinylmethyl cyclic siloxane complexes are particularly preferable. Ph represents a phenyl group. The amount of the catalyst used is preferably 0.1 mass ppm to 1000 mass ppm, more preferably 0.5 to 100 mass ppm, and more preferably 1 to 50 mass based on the amount of the silsesquioxane derivative. More preferably, it is ppm.

  When using a catalyst for hydrosilylation reaction, a hydrosilylation reaction inhibitor may be added to suppress gelation and improve storage stability of the silsesquioxane derivative to which the catalyst is added. Examples of hydrosilylation reaction inhibitors include methylvinylcyclotetrasiloxane, acetylene alcohols, siloxane-modified acetylene alcohols, hydroperoxides, hydrosilylation reaction inhibitors containing nitrogen atoms, sulfur atoms, or phosphorus atoms. .

(Secondary cured product and secondary curing method of silsesquioxane derivative>
The secondary cured product of the silsesquioxane derivative can be obtained by applying further heat treatment to the primary cured product. As the temperature at which the primary cured product is heat-treated, various aspects relating to the temperature for the heat treatment for obtaining the main curing already described can be adopted. By curing at the temperature described above as the heat treatment temperature for obtaining the main cured product, a secondary cured product of the silsesquioxane derivative having excellent heat resistance can be obtained.

  Although the heat processing time for secondary curing is not specifically limited, For example, it is 0.1 to 10 hours normally, and 0.5 to 5 hours are preferable.

  The curing process of the silsesquioxane derivative including primary curing and secondary curing of the silsesquioxane derivative may be performed in air with or without a catalyst, or in an inert gas atmosphere such as nitrogen gas. Or may be carried out under reduced pressure. However, in order to promote the reaction of the alkoxysilyl group present in the silsesquioxane derivative, it is preferable that the atmosphere contains water to such an extent that the alkoxysilyl group can undergo a hydrolysis reaction. In the air, the hydrolysis reaction of the alkoxysilyl group proceeds due to moisture contained in the air, and the hydrosilyl group is oxidized by oxygen to form a hydroxysilyl group, so that sufficient curing can proceed. . On the other hand, in an inert gas atmosphere or under reduced pressure, it is less susceptible to volume changes due to oxidation, and a cured product with few cracks can be obtained. As another method for producing a cured product of a silsesquioxane derivative, a method in which primary curing is performed in air and secondary curing is performed in air, an inert gas atmosphere such as nitrogen gas, or under reduced pressure is preferable.

  The heat resistance of the cured product can be evaluated by a differential thermothermal gravimetric simultaneous measurement device (TG / DTA) or the like. The cured product of the silsesquioxane derivative obtained by curing the silsesquioxane derivative without using a catalyst for hydrosilylation reaction can have a weight reduction rate of about 5% at 1000 ° C. Showing gender. Moreover, even if the catalyst for hydrosilylation reaction is used, the weight reduction rate at 1000 degreeC of hardened | cured material can be about 10% by adjustment of the catalyst amount etc., and high heat resistance is shown.

In addition to such heat resistance, the cured product was found to have characteristics to be used as an insulating element of a semiconductor device. The relative dielectric constant of this hardened | cured material can be 3.0 or less, for example. In addition, More preferably, it is 2.5 or less. The relative dielectric constant is, for example, a 70 mm × 70 mm × 2 mm copper plate and a silsesquioxane derivative (which may or may not contain a catalyst. The same applies to the preparation of test samples hereinafter). Is applied by spin coating and cured to prepare a test sample (70 mm × 70 mm × 2 μm thickness), and the test sample can be measured by a bridge method. The dielectric constant is HP4284A LCR (manufactured by Agilent Technologies, Inc.) or an equivalent thereof as an impedance analyzer, and electrode: HP16451B (manufactured by Agilent Technologies, Inc.) or an equivalent thereof. Measurements can be made.
<Measurement conditions>
Pretreatment for measurement: In air (21 ± 1 ° C, 54 ± 4% RH, 96 hours)
Measurement atmosphere: In air (21 ° C, 51% RH)
Main electrode diameter: 38mm
Electrode material: Conductive silver paste Doutite D-500 (manufactured by Fujikura Kasei Co., Ltd.)
Applied voltage: 1.00V
Frequency: 1MHz
Integration count: 256 times

  Moreover, the dielectric breakdown voltage of this hardened | cured material can be 10 kV / mm or more. Preferably, it is 20 kV / mm or more, More preferably, it is 30 kV / mm or more, More preferably, it is 40 kV / mm or more, More preferably, it is 50 kV / mm or more. For the breakdown voltage, a silver paste is applied on a conductive plate such as a copper plate, and a test piece (mainly cured product (size 40 mm × 40 mm × thickness 450 μm) is placed thereon and left in the air for 24 hours. Then, the copper plate is covered with an insulator other than the test piece, and the current is increased from 0 V to 20 V / sec at 5 mA AC using a KIKUSUI Electronic Corp. TOS 8700, Withstanding Voltage Tester or equivalent. It can be obtained by reading the voltage at the time.

  The linear expansion coefficient of this hardened | cured material can be 100 ppm / degrees C (100 degreeC-300 degreeC) or less. Preferably, it is 50 ppm / ° C (100 ° C to 300 ° C) or less, more preferably 20 ppm / ° C (100 ° C to 300 ° C) or less, and further preferably 15 ppm / ° C (100 ° C to 300 ° C) or less. It is. The linear expansion coefficient of the cured product may be 50 ppm / ° C. (200 ° C. to 300 ° C.), 20 ppm / ° C. (200 ° C. to 300 ° C.), or 15 ppm / ° C. (200 ° C. to 300 ° C.). The cured product tends to have a good coefficient of linear expansion because mineralization proceeds at a higher temperature.

For example, the linear expansion coefficient is obtained by pouring a silsesquioxane derivative into a mold in which a size of 1 cm × 1 cm × 2 mm thickness is hollowed and curing the test sample (1 cm × 1 cm × 2 mm thickness). Using a thermomechanical analyzer (TMA Q400, manufactured by TA Instruments) or an equivalent thereof, the sample can be heated to 300 ° C. at 5 ° C./min and measured in a compressed mode in an N ₂ atmosphere.

The thermal diffusion coefficient of this hardened | cured material can be 0.1 mm < ² > / s or more. Preferably, it is 0.2 mm ² / s or more, more preferably 0.3 mm ² / s or more. The thermal diffusion coefficient is, for example, a test sample (13 mm × 13 mm × 1 mm thickness) prepared by pouring a silsesquioxane derivative into a mold hollowed out with a size of 13 mm × 13 mm × 1 mm thickness. The thermal diffusivity measuring device based on the laser flash method (for example, LFA467, manufactured by NETZSCH) or an equivalent thereof can be used. The cured product is subjected to heat treatment at a temperature of 400 ° C. or higher, more preferably 450 ° C. or higher, more preferably 500 ° C. or higher, still more preferably 550 ° C. or higher, more preferably 600 ° C. or higher. Since the inorganic structure is considered to increase due to the crosslinking reaction based on the group and / or the hydrosilyl group, it can have excellent thermal conductivity as compared with conventional polyimides and epoxy resins.

  The cured product preferably has all of these various characteristics.

  Curing of the silsesquioxane derivative including primary curing and secondary curing of the silsesquioxane derivative can be carried out in various forms. For example, since the silsesquioxane derivative is a liquid substance having a viscosity at 25 ° C. of 30000 mPa · s or less, it can be directly applied to the substrate in the primary curing, but diluted with a solvent as necessary. Can also be used. When the solvent is used, a solvent that dissolves the silsesquioxane derivative is preferable, and examples thereof include aliphatic hydrocarbon solvents, aromatic hydrocarbon solvents, chlorinated hydrocarbon solvents, alcohol solvents, ether solvents, amides. Examples include various organic solvents such as a solvent, a ketone solvent, an ester solvent, and a cellosolve solvent. When a solvent is used, it is preferable to volatilize the solvent contained in the applied film prior to heating for curing the silsesquioxane derivative. The solvent may be volatilized in the air, in an inert gas atmosphere, or under reduced pressure. Although heating may be performed for volatilization of the solvent, the heating temperature in that case is preferably less than 200 ° C, more preferably 50 ° C or more and 150 ° C or less. In another production method of the cured product, the silsesquioxane derivative may be partially cured by heating to 50 ° C. or more and less than 200 ° C. or 50 ° C. or more and 150 ° C. or less, and this may be used as a solvent volatilization step. is there.

  When the silsesquioxane derivative is subjected to curing, various additives may be added. Examples of the additive include reactive diluents such as tetraalkoxysilane and trialkoxysilanes (trialkoxysilane, trialkoxyvinylsilane, etc.). These additives are used as long as the obtained cured product does not impair the heat resistance.

<Semiconductor device and manufacturing method thereof>
The method for manufacturing a semiconductor device disclosed in the present specification includes an insulating material including a silsesquioxane derivative having a hydrosilyl group, a carbon-carbon unsaturated bond, and an alkoxysilyl group at a site serving as an insulating element of the semiconductor device. And a curing step of curing the composite. The present manufacturing method is a method in which a step of supplying a silsesquioxane derivative to a portion to be an insulating element of a semiconductor device and then curing the composite by heat treatment is performed during or after the manufacturing step of the semiconductor device. It is. According to this production method, since the silsesquioxane derivative can be supplied in a liquid form or the like, it can be applied to various shapes and fine locations.

  In the supply process, the supply form of the silsesquioxane derivative to the site serving as the insulating element is not particularly limited, but for example, a normal coating method such as a cast method, a spin coat method, a bar coat method, or the like is used. be able to.

  The heat treatment of the silsesquioxane derivative in the curing step can be carried out in various modes for obtaining the already-cured product. That is, the silsesquioxane derivative can be heat-treated at a temperature that is an excellent insulating element in a semiconductor device, and may be batch curing or two-stage curing. For example, by performing the curing step so as to include the primary curing step for obtaining the primary cured product described above and the secondary curing step for obtaining the secondary cured product by curing the primary cured product by further heat treatment, An insulating element having stable characteristics can be given to the semiconductor device.

  Another method for manufacturing a semiconductor device is a cured product of a silsesquioxane derivative having a hydrosilyl group, a carbon-carbon unsaturated bond, and an alkoxysilyl group at a site to be an insulating element of the semiconductor device, A supply step of supplying an insulating material containing a primary cured product of the silsesquioxane derivative by polycondensation of an alkoxysilyl group and / or hydrosilylation of a carbon-carbon unsaturated bond; and the primary cured product by further heat treatment A secondary curing step of curing to obtain a secondary cured product. According to this method, since the primary cured product is applied to a portion that becomes an insulating element of the semiconductor device, the primary curing step in the manufacturing process of the semiconductor device can be omitted. In this production method, both the primary curing step and the secondary curing step can be performed in the various aspects already described.

  The supply process, the curing process, the primary curing process, and the secondary curing process in the method for manufacturing a semiconductor device disclosed in this specification are appropriately performed according to the form in which the insulating element including the cured product is applied to the semiconductor device. Can be done at any time. The supply process and various curing processes of the silsesquioxane derivative and the primary cured product thereof are the purposes of the final cured product in the semiconductor device, for example, surface protection, sealing, element separation, wiring coating, heat dissipation, It is carried out by a method and timing suitable for realizing cooling or the like.

Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited to this embodiment. “Mn” and “Mw” mean a number average molecular weight and a weight average molecular weight, respectively, and are linked at 40 ° C. in a toluene solvent by gel permeation chromatography (hereinafter abbreviated as “GPC”). Are separated using the GPC columns “TSK gel G4000HX” and “TSK gel G2000HX” (model name, manufactured by Tosoh Corporation), and the molecular weight is calculated from the retention time using standard polystyrene. Further, in ¹ H-NMR analysis of the obtained silsesquioxane derivative, a sample was dissolved in deuterated chloroform, and measurement and analysis were performed. Furthermore, the viscosity of the obtained silsesquioxane derivative was measured at 25 ° C. using an E-type viscometer.

(Synthesis of Silsesquioxane Derivative 1)
A four-necked flask was equipped with a magnetic stirrer, a dropping funnel, a reflux condenser, and a thermometer, and the atmosphere in the flask was changed to a nitrogen gas atmosphere. Next, the magnetic stir bar, triethoxysilane 1,330.6 (8.1 mol), trimethoxyvinylsilane 400.2 g (2.7 mol), dimethyldimethoxysilane 162.2 g (1.35 mol), 1, Accommodates 362.6 g (2.7 mol) of 1,3,3-tetramethyldisiloxane, 173.4 g of 2-butanol, 562.6 g of 2-propanol and 1,951.2 g of xylene, and the contents at 25 ° C. While stirring the above, a mixture of 642.7 g of 1.59 mass% hydrochloric acid aqueous solution, 86.8 g of 2-butanol and 281.2 g of 2-propanol was dropped from the dropping funnel over 1 hour. A condensation reaction was performed. After completion of dropping, the reaction solution was allowed to stand at 25 ° C. for 18 hours.

  Thereafter, the pressure inside the flask was reduced to 100 Pa and heated to 60 ° C. to distill off volatile components including water. As a result, 1,014.4 g of an almost colorless liquid (hereinafter referred to as “silsesquioxane derivative (1)”) was obtained. With respect to this silsesquioxane derivative (1), Mn was measured by GPC to be 1,700. Moreover, Mw was 3,600. When the viscosity was measured with an E-type viscometer, it was 130 mPa · s (25 ° C.).

(Synthesis of Silsesquioxane Derivative 2)
A four-necked flask was equipped with a magnetic stirrer, a dropping funnel, a reflux condenser, and a thermometer, and the atmosphere in the flask was changed to a nitrogen gas atmosphere. Next, a magnetic stir bar, 1,478.4 g (9 mol) of triethoxysilane, 444.7 g (3 mol) of trimethoxyvinylsilane, 403.0 g (3 mol) of 1,1,3,3-tetramethyldisiloxane were added to the flask. 2-butanol 177.8 g, 2-propanol 577.00 g and xylene 2,000. Then, while stirring the contents at 25 ° C., a mixture of 659.2 g of 1.59 mass% hydrochloric acid aqueous solution, 89.0 g of 2-butanol and 288.4 g of 2-propanol was added from the dropping funnel over 1 hour. The solution was added dropwise to conduct hydrolysis / polycondensation reaction. After completion of dropping, the reaction solution was allowed to stand at 25 ° C. for 18 hours.

  Thereafter, the pressure inside the flask was reduced to 100 Pa and heated to 60 ° C. to distill off volatile components including water. As a result, 892.0 g of an almost colorless liquid (hereinafter referred to as “silsesquioxane derivative (2)”) was obtained. With respect to this silsesquioxane derivative (2), Mn was measured by GPC and found to be 1,900. Moreover, Mw was 4,500. Moreover, when the viscosity was measured with the E-type viscosity meter, it was 370 mPa * s (25 degreeC).

The composition ratio (molar ratio) of the obtained silsesquioxane derivative was measured by ¹ H-NMR measurement of the silsesquioxane derivative, and the signal with chemical shift δ (ppm) of −0.2 to 0.6 was Based on the structure of Si—CH ₃ , δ (ppm) of 0.8 to 1.5 is based on the structures of OCH (CH ₃ ) CH ₂ CH ₃ , OCH (CH ₃ ) ₂ and OCH ₂ CH ₃ , ppm) is from 3.5 to 3.9 based on the structure of OCH ₂ CH ₃ , and δ (ppm) is from 3.9 to 4.1 based on the structure of OCH (CH ₃ ) CH ₂ CH _3. , Δ (ppm) of 4.2 to 5.2 is based on the Si—H structure, and δ (ppm) of 5.7 to 6.3 is based on the CH═CH ₂ structure. Therefore, simultaneous equations for the side chain were determined from each signal intensity integrated value. Regarding the structural unit T, since it is known that the charged monomers (triethoxysilane, trimethoxyvinylsilane, etc.) are incorporated into the silsesquioxane derivative as they are, from the charged values of all the monomers and the NMR measurement values, The molar ratio of each structural unit contained in the silsesquioxane derivative was determined. These results are shown in Table 1.

In the silsesquioxane derivative (1), in the formula (1), the structural unit (1-2) is (H—SiO _3/2 ) and v = 3.0, and the structural unit (1-3) Is (Vi (vinyl group) SiO _3/2 ) and w = 1.0, the structural unit (1-4) is (Me ₂ SiO _2/2 ) and x = 0.5, The structural unit (1-5) is (H (Me) ₂ SiO _1/2 ), y = 1.2, the structural unit (1-6) is (SecBuO _1/2 ), and (iPrO _1/2 ). ) And (EtO _1/2 ), where z = 0.08, 0.05 and 0.050, respectively.

In the silsesquioxane derivative (2), in the formula (1), the structural unit (1-2) is (H—SiO _3/2 ) and v = 3.0, and the structural unit (1-3) Is (Vi (vinyl group) SiO _3/2 ), w = 1.0, the structural unit (1-5) is (H (Me) ₂ SiO _1/2 ), and y = 1.2. And the structural unit (1-6) is (SecBuO _1/2 ), (iPrO _1/2 ) and (EtO _1/2 ), and z = 0.08, 0.04 and 0.047, respectively. there were.

  10. 10 g of each silsesquioxane derivative obtained in Example 1 was added to a Pt catalyst (platinum carbonyl cyclovinylmethylsiloxane complex: 1.85-2.1% Pt / cyclomethylvinylsiloxane, Gelext, SIP 6829.2). 5 mg was added and heated at 100 ° C. for 1 hour to obtain a primary cured product (25 ppm as Pt concentration).

  Thereafter, this primary cured product was heated up to 400 ° C. at a rate of 10 ° C./min under nitrogen flow, and kept at 400 ° C. for 1 hour to be heated to obtain a secondary cured product. In addition, the primary cured product is heated to 450 ° C., 500 ° C., 550 ° C., and 600 ° C. at a similar temperature increase rate under nitrogen flow, and held at each temperature for 1 hour to obtain the secondary cured product. Obtained.

  In addition, the primary hardened | cured material (catalyst use) obtained in Example 2 has a crosslinked structure mainly by hydrosilylation reaction, and it turns out that the hydrolysis and polycondensation of an alkoxy silyl group are suppressed. In addition, it was found that the secondary cured product obtained by heat treatment at 400 ° C. obtained in Example 1 further progressed in the hydrosilylation reaction cross-linking structure, and the hydrolysis and polycondensation by the alkoxysilyl group was still suppressed. Yes. Furthermore, it is known that the secondary cured product heat-treated at 550 ° C. has a further increased cross-linked structure due to the hydrosilylation reaction, while hydrolysis and polycondensation with alkoxysilyl groups proceed.

  For the primary and secondary cured products of the silsesquioxane derivative (1) and silsesquioxane derivative (2), heat resistance, dielectric constant, dielectric breakdown voltage, linear expansion coefficient and thermal diffusion coefficient are as follows. Was measured. These results are shown in Table 2.

(1) Heat resistance (TGA)
The heat resistance was evaluated by increasing the temperature of the cured product of the silsesquioxane derivative from 30 ° C. to a predetermined temperature and decreasing the thermal weight during that time. Using a thermal analyzer (TGDTA6300 manufactured by Hitachi High-Tech Science Co., Ltd.), the cured product 5-6 mg was heated from 30 ° C. to 1000 ° C. at a rate of temperature increase of 20 ° C./min under a nitrogen gas flow of 200 ml / min. The weight change during that time was measured to determine the weight loss rate.

(2) Relative permittivity On a copper plate of 70 mm × 70 mm × 2 mm, the silsesquioxane derivative was primarily cured to obtain a test sample (70 mm × 70 mm × 2 μm thickness). The relative permittivity of this test sample can be measured by the bridge method. The relative dielectric constant was measured using HP4284A LCR (manufactured by Agilent Technologies) as an impedance analyzer and electrode: HP16451B (manufactured by Agilent Technologies) under the following conditions.
<Measurement conditions>
Pretreatment for measurement: In air (21 ± 1 ° C, 54 ± 4% RH, 96 hours)
Measurement atmosphere: In air (21 ° C, 51% RH)
Main electrode diameter: 38mm
Electrode material: Conductive silver paste Doutite D-500 (manufactured by Fujikura Kasei Co., Ltd.)
Applied voltage: 1.00V
Frequency: 1MHz
Integration count: 256 times

(3) Dielectric breakdown voltage A silver paste was applied on a copper plate, and a test piece (cured silsesquioxane (size 40 mm × 40 mm × thickness 450 μm) was placed thereon and left in the air for 24 hours. Then, the area other than the test piece on the copper plate was covered with an insulator, and the voltage was increased from 0 V to 20 V / sec at 5 mA AC using a KIKUSUI Electronic Corp. TOS 8700, Whisting Voltage Tester and energized. Was taken as the dielectric breakdown voltage.

(4) Linear expansion coefficient (100 ° C to 300 ° C)
A test sample (1 cm × 1 cm × 2 mm thickness) was prepared by pouring a silsesquioxane derivative into a mold in which a size of 1 cm × 1 cm × 2 mm thickness was hollowed and cured. The test sample was heated to 300 ° C. at 5 ° C./min using a thermomechanical analyzer (TMA Q400, manufactured by TA Instruments), and measured in a compression mode in an N ₂ atmosphere. In Table 1, the linear expansion coefficient is expressed by linear expansion coefficient (1) to linear expansion coefficient (2). A linear expansion coefficient (1) is a linear expansion coefficient in 200 to 300 degreeC, and a linear expansion coefficient (2) is a linear expansion coefficient in 100 to 200 degreeC.

(5) Thermal diffusion coefficient A test sample (13 mm × 13 mm × 1 mm thickness) was prepared by pouring a silsesquioxane derivative into a mold hollowed out with a size of 13 mm × 13 mm × 1 mm thickness. About this test sample, it measured using the thermal diffusivity measuring apparatus (LFA467, the product made from NETZSCH) based on the laser flash method.

  As shown in Table 2, the primary cured product and the secondary cured product of the silsesquioxane derivative (1) and the silsesquioxane derivative (2) both showed high heat resistance. Moreover, in addition to the excellent heat resistance of the secondary cured product having a curing temperature (heat treatment temperature) of 400 ° C., 450 ° C., 500 ° C., 550 ° C. and 600 ° C., the secondary cured product having a curing temperature of 550 ° C. is more excellent. It was found that it exhibits linear expansion coefficient and thermal diffusion coefficient.

  Moreover, the relative dielectric constant of the primary cured product of the silsesquioxane derivative is sufficiently low, and the dielectric breakdown voltage of the primary cured product and the secondary cured product of the silsesquioxane derivative is determined between the measuring device and the cured product. Although the maximum value is unknown for convenience, it was at least 10 kV / mm or more. From the above, it has been found that when the heat treatment temperature of the silsesquioxane derivative is 400 ° C. or higher, preferably 550 ° C. or higher, heat resistance and good insulating properties are exhibited.

  Furthermore, from the results of the linear expansion coefficient and thermal diffusion coefficient of the primary cured product and the secondary cured product of the silsesquioxane derivative, a temperature at which the hydrosilylation reaction is accelerated is 400 ° C. or higher, more preferably a temperature of 550 ° C. or higher. It was found that any cured product obtained by heat treatment at 1 stably exhibits a good linear expansion coefficient. It was also found that the linear expansion coefficient was further improved when the heat treatment temperature was high. It has been found by the present inventors that the thermal weight loss is maintained at 1000 ° C. or less, preferably 800 ° C. or less. From the above, the cured product obtained by heat-treating the silsesquioxane derivative at 400 ° C. or more and 1000 ° C. or less maintains a sufficient cross-linked structure, exhibits a good linear expansion coefficient regardless of the heat treatment temperature, and is 550 ° C. And a higher coefficient of linear expansion on the higher temperature side of 600 ° C.

  Furthermore, from the result of the thermal diffusion coefficient for the primary cured product and the secondary cured product of the silsesquioxane derivative, the silsesquioxane derivative is subjected to heat treatment at a high temperature of 400 ° C. or higher, for example, a temperature of 550 ° C. or higher. It was found that a cured product exhibits a good thermal diffusion coefficient stably. Further, from these results, the cured product is a material close to a resin when the heat treatment temperature is less than 400 ° C., but as the heat treatment temperature becomes higher, it becomes inorganic (ceramics), so that the thermal conductivity is improved, It was found that good thermal conductivity can be exhibited.

  From the above, the secondary cured product obtained by heat-treating a cured product or primary cured product of a silsesquioxane derivative having a hydrosilyl group, a carbon-carbon unsaturated bond and an alkoxysilyl group has a composition and structure. It was found that various characteristics required as an insulating element of a semiconductor device were extremely good with substantial changes.

Moreover, since the cured product of the silsesquioxane derivative is a cured product obtained by heat treatment at a temperature of 400 ° C. or higher, preferably 550 ° C. or higher, it exhibits stable and stable characteristics. It has been found that the semiconductor device is suitable as a material for an insulating element of a semiconductor device that requires high heat resistance, such as a semiconductor device that operates at a high temperature.

Claims (14)

A semiconductor device,
The insulating element in the semiconductor device includes a cured product of a silsesquioxane derivative,
The silsesquioxane derivative includes a silsesquioxane derivative having a hydrosilyl group, a carbon-carbon unsaturated bond, and an alkoxysilyl group.   The cured product is a secondary curing obtained by heat-treating a primary cured product of the silsesquioxane derivative by polycondensation of the alkoxysilyl group and / or hydrosilylation of a carbon-carbon unsaturated bond at a temperature of 400 ° C. or higher. The semiconductor device according to claim 1, wherein the semiconductor device is a product.   The semiconductor device according to claim 2, wherein a temperature of the heat treatment is 500 ° C. or higher.   The semiconductor device according to claim 2, wherein a temperature of the heat treatment is 800 ° C. or less. The semiconductor device according to claim 1, wherein the silsesquioxane derivative is represented by the following formula (1).

[In the formula, A is an organic group having 2 to 10 carbon atoms having a carbon-carbon unsaturated bond capable of hydrosilylation reaction, R ¹ is an alkylene group having 1 to 20 carbon atoms, and 6 carbon atoms. At least one selected from a divalent aromatic group having 20 to 20 carbon atoms and a divalent alicyclic group having 3 to 20 carbon atoms, n is 0 or 1, R ² is a hydrogen atom, carbon An alkyl group having 1 to 10 atoms and an organic group having 2 to 10 carbon atoms having a carbon-carbon unsaturated bond capable of hydrosilylation reaction (R ^{2 in} one molecule may be the same or different. R ³ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, and a carbon atom having 2 to 10 carbon atoms having a carbon-carbon unsaturated bond that can be hydrosilylated. At least one selected from organic groups, R ⁴ is hydrogen An atom, an alkyl group having 1 to 10 carbon atoms, and an organic group having 2 to 10 carbon atoms having a carbon-carbon unsaturated bond capable of hydrosilylation reaction (R ^{4 in} one molecule is the same or different. R ⁵ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, v and z are positive numbers, and u, w, x and y are 0 or a positive number, at least one of w, x and y is a positive number, 0 ≦ u / (v + w + x + y) ≦ 2, 0 ≦ x / (v + w) ≦ 2, and 0 ≦ y / (v + w) ≦ 2 and 0 ≦ z / (v + w + x + y) ≦ 1. However, when w = 0, any one of R ² , R ³ and R ⁴ is an organic group having 2 to 10 carbon atoms having a carbon-carbon unsaturated bond capable of hydrosilylation reaction. ]   The semiconductor device according to claim 1, wherein a relative dielectric constant of the cured product is 3.0 or less.   The semiconductor device according to claim 1, wherein a dielectric breakdown voltage of the cured product is 10 kV / mm or more.   The semiconductor device according to claim 1, wherein a linear expansion coefficient of the cured product is 100 ppm / ° C. (100 ° C. to 300 ° C.) or less.   The semiconductor device according to claim 1, wherein the cured product has a linear thermal expansion coefficient of 50 ppm / ° C. (100 ° C. to 300 ° C.) or less. The semiconductor device according to claim 1, wherein the cured product has a thermal diffusion coefficient of 0.1 mm ² / s or more. A method for manufacturing a semiconductor device, comprising:
A supply step of supplying an insulating material containing a silsesquioxane derivative having a hydrosilyl group, a carbon-carbon unsaturated bond, and an alkoxysilyl group to a portion to be an insulating element of the semiconductor device;
A curing step of curing the silsesquioxane derivative;
A manufacturing method comprising:   The curing step includes a primary curing step of obtaining a primary cured product by primary curing by polycondensation of the alkoxysilyl group and / or hydrosilylation of a carbon-carbon unsaturated bond, and curing the primary cured product by further heat treatment. The manufacturing method of Claim 11 including the secondary curing process of obtaining a secondary-cured material.   The said secondary hardening process is a manufacturing method of Claim 12 which is a process of heat-processing the said primary hardened | cured material at the temperature of 400 degreeC or more. A method for manufacturing a semiconductor device, comprising:
A cured product of a silsesquioxane derivative having a hydrosilyl group, a carbon-carbon unsaturated bond and an alkoxysilyl group at a site serving as an insulating element of the semiconductor device, wherein the polycondensation of the alkoxysilyl group and / or carbon A supply step of supplying an insulating material containing a primary cured product of the silsesquioxane derivative by hydrosilylation of a carbon unsaturated bond;
A secondary curing step of curing the primary cured product by further heat treatment to obtain a secondary cured product;
A manufacturing method comprising: