JP2003115482A - Insulation film forming composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insulation film forming coat composition which has a low dielectric constant, a high mechanical strength such as modulus of elasticity and a superior storage stability, will not cause defects such as cracks even in thick films and obtains a low dielectric constant material at low temperature little in quantity of produced gas. SOLUTION: The insulation film forming composition contains an organic polymer, components A, B, C, and/or a hydrolysate or condensate of these components. The contents of silicon atoms originating from the components A, B, C, and/or a hydrolysate or condensate of these components are within such a range in atomicity ratio that the content of silicon atoms originating from the component A and/or its hydrolysate or condensate is 20 to 45%, the content of silicon atoms originating from the component B is 30 to 60%, and the content of silicon atoms originating from the component B is 10 to 30%. The component A: R1 Si(OR2 )3 wherein R1 and R2 are monovalent organic groups, the component B: (R3 O)3 Si-R5 -Si(OR4 )3 wherein R3 and R4 are monovalent organic groups and R5 is a bivalent organic group, and the component C: Si(OR6 )4 wherein R6 is a monovalent organic group.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an insulating film forming composition for forming an interlayer insulating film material used for a semiconductor element or the like.

[0002]

2. Description of the Related Art In recent years, with the increase in speed and miniaturization of semiconductor devices, there is an increasing demand for reducing the delay of signal propagation due to the resistance of wiring and the capacitance between wirings. As a promising means for that purpose, a method of using a material having a relative dielectric constant lower than that of silicon oxide, which has been conventionally used, has been proposed as an interlayer insulating layer for insulating wires from each other. Examples of the material for the interlayer insulating layer having such a low relative dielectric constant (hereinafter simply referred to as “low dielectric constant material”) include, for example, a material in which fluorine or carbon is introduced into silicon oxide, an organic polymer, or voids in these materials. Materials having a reduced density by introducing (hereinafter referred to as “porous material”), and mixtures thereof are known. In particular, porous materials have attracted attention as low dielectric constant materials that can achieve a relative dielectric constant of 2.3 or less, which is significantly lower than that of silicon oxide.

A typical porous material is a material composed of a mixture containing a hydrolyzate of alkoxysilane and an organic polymer. Such a material itself is a solution and can be used as a coating solution as it is, or can be prepared as a coating solution by using an appropriate solvent. Taking advantage of this feature, if the coating solution is coated on a substrate and then heated and sintered under appropriate conditions, a siloxane bond is generated by condensation of a hydrolysis product of an alkoxysilane, and the organic polymer is evaporated or Since it is thermally decomposed to form pores, a low dielectric constant material made of a porous material can be easily obtained. Hereinafter, the coating liquid used for this purpose is referred to as "insulating film forming composition".

When a low dielectric constant material is obtained by using a composition for forming an insulating film, it is necessary not only to have a low relative dielectric constant but also to meet some performance requirements depending on the purpose. For example, since this method obtains a low dielectric constant material through the step of applying a solution, it requires uniform film thickness during application. Further, the composition for forming an insulating film is required to have storage stability, and it is not desirable that a specific component gels or a specific component separates from other components during storage. Further, since the obtained low dielectric constant material is a thin film, mechanical defects such as cracks should not occur within the required thickness range. Further, when a low dielectric constant material is processed, the generation of gas mainly from the inside of the material may impair the processing performance, so that the generation of gas must be suppressed as much as possible.

As a method, it is convenient to apply a sufficiently high temperature when firing the composition for forming an insulating film.
Generally, in the process of forming a semiconductor element, a temperature exceeding 400 ° C. cannot be applied for reasons such as ensuring the reliability of the element, so it is necessary to reduce the gas generated as the performance of the insulating film forming composition itself. Furthermore, in recent years, when it is applied to a semiconductor element, chemical mechanical polishing (CMP) may be applied for the purpose of flattening the element, but at that time, mechanical defects such as film destruction should not occur. I won't. In addition, since the obtained low dielectric constant material is used inside a semiconductor element, it is generally necessary to reduce the contamination by heavy metals and alkali metals.

To meet the above requirements, many compositions for forming an insulating film have been proposed so far. To give an example, Japanese Patent Laid-Open No. 2001-106914 discloses a composition comprising an alkoxysilane or the like and an aliphatic polyether or the like, wherein at least one of the terminal groups of the aliphatic polyether or the like is an alkyl ether or the like. Things are disclosed. A low dielectric constant material having a relative dielectric constant of 2.0 to 2.5 can be obtained by applying the composition for forming an insulating film and baking it at 400 ° C. In addition, JP 2001-4
Japanese Patent No. 9179 discloses a composition comprising an alkoxysilane or the like, an alkoxysilylalkane, and a polyether in which one of the terminal groups is a monovalent organic group having 5 to 30 carbon atoms. According to this insulating film forming composition, a low dielectric constant material having a relative dielectric constant of 2.4 or lower can be obtained, and its elastic modulus is 3.9 to 4.7 GP.
It is disclosed that a is obtained. In addition, it was evaluated by the change in film thickness when the composition left to stand at 40 ° C. was baked after coating.
It is also disclosed that the rate of change remains within 0%.

However, the conventionally known techniques do not meet all the requirements for the insulating film forming composition. For example, according to the technique described in JP 2001-106914 A mentioned above, a low dielectric constant material is fired at a firing temperature of 400.
Although it can be prepared at 0 ° C., its film thickness is described only up to 1.3 μm, and its storage stability is not described. Further, Japanese Patent Application Laid-Open No. 2001-49179 describes storage stability, film thickness uniformity, and CMP resistance, but storage stability is low when obtained using this insulating film forming composition. It is evaluated by the change in the film thickness of the dielectric constant material, and the change in the properties of the composition itself is not described. Further, the firing temperature for obtaining the low dielectric constant material is 425 ° C., which is required for manufacturing a semiconductor element.
There is no description about the characteristics when firing at 00 ° C. or lower.

[0008]

The present invention not only has a low dielectric constant, but also does not cause defects such as cracks even in a thick film, has a high mechanical strength such as an elastic modulus, and has a low gas generation amount. An object is to obtain a coating composition for forming an insulating film, which can obtain a dielectric constant material at a low temperature and is excellent in storage stability.

[0009]

The present invention provides an insulating film-forming composition containing an organic polymer and the following components A, B and C, or a hydrolyzate or condensate of these components. The composition ratio of B and C is 20% or more and 45% or less in terms of the number ratio of silicon atoms contained in each, 30
% To 60% and 10% to 30%. Here, component A and component B
The component C and the component C are represented by the following general formula. Component A: R ₁ Si (OR ₂ ) ₃ (wherein R ₁ and R ₂
A monovalent organic group) Component _{B: (R 3 O) 3 Si} -R 5 -Si (OR 4)
₃ (wherein R ₃ and R ₄ are monovalent organic groups, R ₅ is a divalent organic group) Component C: Si (OR ₆ ) ₄ (In the formula, R ₆ is a monovalent organic group)

Since the composition for forming an insulating film of the present invention may contain a hydrolyzate or a condensate of each of the above components, the component contained in the composition for forming an insulating film is not necessarily Component A. It is not always the only compound represented by the chemical structural formula of B, C or C. Therefore, the composition of each component will be defined by the atomic ratio of silicon atoms contained in each component. Component A, even if it is a hydrolyzate or a condensate thereof, is characterized in that only one of the tetravalent bonds of a silicon atom is a monovalent organic group and the other trivalent is bonded to an oxygen atom. Therefore, the composition ratio of the component A contained in the insulating film-forming composition can be analyzed by a known analysis method capable of identifying the chemical environment of silicon atoms, for example, ²⁹ Si-NMR. The same applies to the components B and C. Incidentally, the component B formula _{(R 3 O) 3 Si-} R 5
As can be seen from —Si (OR ₄ ) ₃ , it has two silicon atoms in one molecule. Therefore, when the insulating film-forming composition contains x mol of the compound represented by the general formula (R ₃ O) ₃ Si—R ₅ —Si (OR ₄ ) ₃ , it is 2 as a silicon atom.
x mol is included. Therefore, when the composition is calculated according to the above definition, the component B is calculated as 2x mol instead of x mol. Further, hereinafter, component AB, component and component C, and / or a hydrolyzate or condensate of these components and having a composition ratio of the present invention are referred to as “alkoxysilanes of the present invention”.

In the alkoxysilanes of the present invention, the composition ratio range to be satisfied by each component is as follows. First, when the composition ratio of the component A exceeds 45%, the mechanical strength of the obtained low dielectric constant material is lowered, and the CMP resistance is lowered. Further, when the composition ratio of the component A is less than 20%, the hygroscopicity becomes high, which may cause degassing when processing a semiconductor element and may not be able to maintain a low dielectric constant.
On the other hand, when the composition ratio of the component B exceeds 60% or when the composition ratio of the component C exceeds 30%, the insulating film forming composition is gelated and cannot be applied. On the contrary, when the composition ratio of the component B is less than 30% or the composition ratio of the component C is less than 10%, the mechanical strength of the obtained thin film made of the low dielectric constant material decreases. As I said,
It is conventionally known that it is possible to obtain a material having a low dielectric constant excellent in mechanical strength such as elastic modulus even if the composition ratio is out of this range. In order to achieve both stability of the composition for use, it is necessary that the composition ratio of the alkoxysilanes of the present invention is within the range.

As the organic polymer contained in the insulating film forming composition, polyethylene glycol dimeter ether is preferably used. This organic polymer is one of the aliphatic polyethers disclosed in the above-mentioned JP 2001-106914A, and the organic polymer in which the terminal of the aliphatic polyether is a methoxy group is the organic polymer of the present invention. Particularly preferred for alkoxysilanes. This organic polymer has a high compatibility with the alkoxysilanes of the present invention, and generates less stress when applied and baked to obtain a low dielectric constant material. Therefore, a thick film can be formed without causing defects such as cracks. Further, even when compared with the aliphatic polyether having a carbon number of 5 to 30 as disclosed in JP 2001-49179 A, the compatibility with the alkoxysilanes of the present invention is significantly improved, After all, it is possible to form a thick film.

The number average molecular weight of the polyethylene glycol dimeter ether used in the present invention is in the range of 400 to 1000, more preferably 500 to 800.
When the number average molecular weight is less than 400, the temperature at which the organic polymer is thermally decomposed or volatilized is low, and the temperature control during firing must be strictly performed in order to obtain a desired low dielectric constant material. On the other hand, when the number average molecular weight exceeds 1,000,
Phase separation tends to occur at low temperatures, and the temperature range in which storage stability can be secured becomes narrow. Number average molecular weight is 5
The range of 00 to 800 is more preferable because the above-mentioned problems do not occur, and it is less affected by factors related to thermal decomposition of the organic polymer during firing, such as oxygen concentration in the firing atmosphere.

Among the alkoxysilanes of the present invention, the general formula (R ₃ O) ₃ Si- (CH ₂ ) _m -Si (OR ₄ ) ₃
The component B represented by is preferably m = 1 or 2. When m> 2, the insulating film forming composition itself tends to gel, and the range of synthesis conditions for obtaining a composition suitable for coating becomes narrow. The most preferable in that sense is m = 2.

A solvent or an additive may be added to the composition for forming an insulating film of the present invention for the purpose of improving coating performance. When water is added as a solvent, the addition amount thereof is preferably 5% or more and 40% or less with respect to the total weight of the insulating film forming composition. If the ratio of water is less than 5%, a radial film thickness distribution (so-called striation) tends to occur depending on the coating conditions, so that it is necessary to precisely control the conditions of the coating device. On the contrary, the ratio of water is 4
If it exceeds 0%, the high heat of vaporization of water itself also tends to deteriorate the film thickness distribution. The particularly preferable ratio of water depends on the composition of the alkoxysilanes of the present invention, the ratio with the organic polymer, and other coexisting solvents. As an example, if propylene glycol methyl ether coexists as a solvent, 20%
To 35% is particularly preferred. Especially from 25% to 35
The range of% has an advantage that the range of storage temperature is wide because it becomes difficult to freeze even at low temperature storage.

As the other solvent used in the composition for forming an insulating film of the present invention, propylene glycol methyl ether or its ester or lactate ester is particularly preferable. The coexistence of this solvent increases the coexistence with the alkoxysilanes of the present invention and has the effect of improving the storage stability. The insulating film forming composition of the present invention can be obtained through various catalytic reactions. For example, if it is an acid catalyst, organic acids such as acetic acid, propionic acid, and maleic acid, and inorganic acids such as nitric acid, sulfuric acid, and phosphoric acid can be used.
A particularly preferable method is a method using an ion exchange resin, and the insulating film-forming composition thus obtained has an advantage that a very small amount of metal, which a semiconductor element dislikes, can be removed at the synthesis stage. It is also possible that the final composition does not contain acid or alkali.

The solvent used at that time is preferably an alcohol having a boiling point of 100 ° C. or lower. Since such an alcohol does not interact with the alkoxysilanes of the present invention during the synthetic reaction, it does not inhibit the thermal decomposition of the organic polymer when the obtained composition for forming an insulating film is coated and baked, and finally obtained. The size of the pores present in the low dielectric constant material obtained is small and uniform. Since such a low dielectric constant material is resistant to deformation by an external force, it has an advantage of improving CMP resistance. Although the present invention is intended for use in semiconductor devices, it can also be used in other applications such as optical devices and liquid crystal display devices.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Modes for carrying out the present invention will be described below. That is, after explaining about alkoxysilanes, organic polymers, solvents, types of catalysts that can be used in the present invention and a preparation method using these, a low dielectric constant material is prepared by using the obtained insulating film forming composition. A method of forming the film will also be described.

The alkoxysilanes of the present invention include, as constituent elements, a component A represented by alkyltrialkoxysilane, a component B represented by bis (trialkoxysilyl) alkane, and a component C represented by tetraalkoxysilane. It is a waste. In obtaining a low dielectric constant material using the insulating film forming composition of the present invention, these components are hydrolyzed and then finally condensed to form a siloxane bond. It is customary that these reactions have not completely proceeded at the stage. Therefore, the composition for forming an insulating film of the present invention includes not only a hydrolyzate of each of Component A, Component B and Component C alone, but also generally a single component or a condensate between a plurality of components.

Component A has the general formula R ₁ Si (OR ₂ ).
₃ (in the formula, R ₁ and R ₂ are monovalent organic groups). Here, R ₁ and R ₂ may be the same or different. Any of them may be a monovalent organic group, and R ₁ may be aliphatic or aromatic. R ₂ is the same, but more preferably a linear alkyl group having 1 to 3 carbon atoms. These have an advantage that they can be used as they are as a synthetic solvent as they are, since they become alcohols having a low boiling point during hydrolysis.

Specific examples of the component A include methyltrimethoxysilane, methyltriethoxysilane, methyltri-n-propoxysilane, methyltri-iso-propoxysilane, methyltri-n-butoxysilane and methyltri-sec-butoxysilane. , Methyl tri-ter
t-butoxysilane, methyltriphenoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane,
Ethyltri-n-propoxysilane, ethyltri-is
o-propoxysilane, ethyltri-n-butoxysilane, ethyltri-sec-butoxysilane, ethyltri-tert-butoxysilane, ethyltriphenoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-propyltri-silane n-Propoxysilane, n-propyltri-iso-propoxysilane, n-propyltri-n-butoxysilane, n-propyltri-sec-butoxysilane, n-propyltri-tert-butoxysilane, n-propyltriphenoxy Silane,

I-propyltrimethoxysilane, i-propyltriethoxysilane, i-propyltri-n-propoxysilane, i-propyltri-iso ^ propoxysilane, i-propyltri-n-butoxysilane, i
-Propyltri-sec-butoxysilane, i-propyltri-tert-butoxysilane, i-propyltriphenoxysilane, n-butyltrimethoxysilane, n
-Butyltriethoxysilane, n-butyltri-n-propoxysilane, n-butyltri-iso-propoxysilane, n-butyltri-n-butoxysilane, n-butyltri-sec-butoxysilane, n-butyltri-
tert-butoxysilane, n-butyltriphenoxysilane, sec-butyltrimethoxysilane, sec-
Butyl-triethoxysilane, sec-butyl-tri-
n-propoxysilane, sec-butyl-tri-iso
-Propoxysilane, sec-butyl-tri-n-butoxysilane, sec-butyl-tri-sec-butoxysilane, sec-butyl-tri-tert-butoxysilane, sec-butyl-triphenoxysilane,

T-Butyltrimethoxysilane, t-butyltriethoxysilane, t-butyltri-n-propoxysilane, t-butyltri-iso-propoxysilane, t-butyltri-n-butoxysilane, t-butyltri-sec- Butoxysilane, t-butyl tri-te
rt-Butoxysilane, t-butyltriphenoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltri-n-propoxysilane, phenyltri-iso-propoxysilane, phenyltri-
In addition to n-butoxysilane, phenyltri-sec-butoxysilane, phenyltri-tert-butoxysilane, phenyltriphenoxysilane, etc., vinyltrimethoxysilane, vinyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-amino Propyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-trifluoropropyltrimethoxysilane, γ-
Examples thereof include trifluoropropyltriethoxysilane.

The component B is represented by the general formula (R ₃ O) ₃ Si-R ₅
It is represented by —Si (OR ₄ ) ₃ (wherein R ₃ and R ₄ are monovalent organic groups, and R ₅ is a divalent organic group). R ₃ and R ₄ may be the same or different. Any of them may be a monovalent organic group, and may be aliphatic or aromatic. Further, as in the case of the component A, a straight chain alkyl group having 1 to 3 carbon atoms produces a low boiling point alcohol upon hydrolysis and can be used as a solvent as it is.

Specific examples of the component B include bis (trimethoxysilyl) methane and bis (triethoxysilyl).
Methane, bis (tri-n-propoxysilyl) methane,
Bis (tri-i-propoxysilyl) methane, bis (tri-n-butoxysilyl) methane, bis (tri-sec)
-Butoxysilyl) methane, bis (tri-t-butoxysilyl) methane and other bis (trialkoxysilyl) methanes; 1,2-bis (trimethoxysilyl) ethane,
1,2-bis (triethoxysilyl) ethane, 1,2-
Bis (tri-n-propoxysilyl) ethane, 1,2-
Bis (tri-i-propoxysilyl) ethane, 1,2-
Bis (tri-n-butoxysilyl) ethane, 1,2-bis (tri-sec-butoxysilyl) ethane, 1,2-
1,2 such as bis (tri-t-butoxysilyl) ethane
-Bis (trialkoxysilyl) ethanes;

1,1-bis (trimethoxysilyl) ethane, 1,1-bis (triethoxysilyl) ethane, 1,
1-bis (tri-n-propoxysilyl) ethane, 1,
1-bis (tri-i-propoxysilyl) ethane, 1,
1-bis (tri-n-butoxysilyl) ethane, 1,1
-Bis (tri-sec-butoxysilyl) ethane, 1,
1,1-bis (trialkoxysilyl) ethanes such as 1-bis (tri-t-butoxysilyl) ethane; 1,
3-bis (trimethoxysilyl) propane, 1,3-bis (triethoxysilyl) propane, 1,3-bis (tri-n-propoxysilyl) propane, 1,3-bis (tri-i-propoxysilyl) Propane, 1,3-bis (tri-n-butoxysilyl) propane, 1,3-bis (tri-sec-butoxysilyl) propane, 1,3
-1,3-bis (trialkoxysilyl) propanes such as bis (tri-t-butoxysilyl) propane;

1,2-bis (trimethoxysilyl) propane, 1,2-bis (triethoxysilyl) propane,
1,2-bis (tri-n-propoxysilyl) propane, 1,2-bis (tri-i-propoxysilyl) propane, 1,2-bis (tri-n-butoxysilyl) propane, 1,2-bis (Tri-sec-butoxysilyl)
Propane, 1,2-bis (tri-t-butoxysilyl)
1,2-bis (trialkoxysilyl) such as propane
Propanes; 2,2-bis (trimethoxysilyl) propane, 2,2-bis (triethoxysilyl) propane,
2,2-bis (tri-n-propoxysilyl) propane, 2,2-bis (tri-i-propoxysilyl) propane, 2,2-bis (tri-n-butoxysilyl) propane, 2,2-bis (Tri-sec-butoxysilyl)
Propane, 2,2-bis (tri-t-butoxysilyl)
2,2-bis (trialkoxysilyl) such as propane
Propanes; 1,1-bis (trimethoxysilyl) propane, 1,1-bis (triethoxysilyl) propane,
1,1-bis (tri-n-propoxysilyl) propane, 1,1-bis (tri-i-propoxysilyl) propane, 1,1-bis (tri-n-butoxysilyl) propane, 1,1-bis (Tri-sec-butoxysilyl)
Propane, 1,1-bis (tri-t-butoxysilyl)
1,1-bis (trialkoxysilyl) such as propane
Propanes;

1,2-bis (trimethoxysilyl) benzene, 1,2-bis (triethoxysilyl) benzene,
1,2-bis (tri-n-propoxysilyl) benzene, 1,2-bis (tri-i-propoxysilyl) benzene, 1,2-bis (tri-n-butoxysilyl) benzene, 1,2-bis (Tri-sec-butoxysilyl)
Benzene, 1,2-bis (tri-t-butoxysilyl)
Benzene, 1,3-bis (trimethoxysilyl) benzene, 1,3-bis (triethoxysilyl) benzene,
1,3-bis (tri-n-propoxysilyl) benzene, 1,3-bis (tri-i-propoxysilyl) benzene, 1,3-bis (tri-n-butoxysilyl) benzene, 1,3-bis (Tri-sec-butoxysilyl)
Benzene, 1,3-bis (tri-t-butoxysilyl)
Benzene, 1,4-bis (trimethoxysilyl) benzene, 1,4-bis (triethoxysilyl) benzene,
1,4-bis (tri-n-propoxysilyl) benzene, 1,4-bis (tri-i-propoxysilyl) benzene, 1,4-bis (tri-n-butoxysilyl) benzene, 1,4-bis (Tri-sec-butoxysilyl)
Benzene, 1,4-bis (tri-t-butoxysilyl)
Bis (trialkoxysilyl) benzenes such as benzene;

1,2-bis (trimethoxysilyl) ethylene, 1,2-bis (triethoxysilyl) ethylene,
1,2-bis (tri-n-propoxysilyl) ethylene, 1,2-bis (tri-i-propoxysilyl) ethylene, 1,2-bis (tri-n-butoxysilyl) ethylene, 1,2-bis (Tri-sec-butoxysilyl)
Ethylene, 1,2-bis (tri-t-butoxysilyl)
1,2-bis (trialkoxysilyl) such as ethylene
Examples include ethylenes.

The component C is represented by the general formula Si (OR ₆ ) ₄ (wherein R ₆ is a monovalent organic group). Typical ones are tetramethoxysilane and tetraethoxysilane,
Including these, when R ₆ is a linear alkyl group having 1 to 3 carbon atoms, the low boiling point alcohol generated by hydrolysis can be used as a solvent as in the case of the component A. Specific examples of the component C include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-
iso-propoxysilane, tetra-n-butoxylan, tetra-sec-butoxysilane, tetra-ter
Examples thereof include t-butoxysilane and tetraphenoxysilane. It should be noted that, if necessary, an alkoxysilane having a divalent monovalent organic group and a remaining divalent alkoxy group among the bonds of silicon atoms as represented by dialkyldialkoxysilane may be added. Is also good.

The insulating film forming composition of the present invention further contains an organic polymer as a constituent factor. This organic polymer is thermally decomposed or volatilized in the process of forming the low dielectric constant material. As an example of the organic polymer, one having an aliphatic polyether, an aliphatic polyester, an aliphatic polycarbonate, an aliphatic polyanhydride or the like as a main constituent component can be used. These organic polymers may be used alone, or two or more kinds may be used in combination, and the main chain of the organic polymer may have any repeating unit other than those described above as long as the effects of the present invention are not impaired. It may include a polymer chain having.

As a concrete example of the aliphatic polyether,
Polyethylene glycol, polypropylene glycol,
Binary block copolymers such as polyisobutylene glycol, polytrimethylene glycol, polytetramethylene glycol, polypentamethylene glycol, polyhexamethylene glycol, polydioxolane, polydioxepane, polyethylene glycol-polypropylene glycol, polyethylene glycol-polybutylene glycol, and Examples thereof include linear ternary block copolymers such as polyethylene glycol-polypropylene glycol-polyethylene glycol, polypropylene glycol-polyethylene glycol-polypropylene glycol, polyethylene glycol-polybutylene glycol-polyethylene glycol.

As the organic polymer of the composition of the present invention, glycerol, erythritol, pentaerythritol,
A structure in which at least three of hydroxyl groups contained in sugar chains typified by pentitol, pentose, hexitol, hexose, heptose, etc. are bound to an organic polymer chain, and / or hydroxyl groups and carboxyl groups contained in hydroxyl acid. At least three of them may have a structure in which block copolymer chains are bonded. The terminal group of the organic polymer used in the present invention is not particularly limited, but it is modified with a hydroxyl group, a linear or cyclic alkyl ether group, an alkyl ester group, an alkylamide group, an alkyl carbonate group, a urethane group or a trialkylsilyl group. Can be used. Examples of modifying the terminal group of the aliphatic polyether include those in which at least one terminal of the above alkylene glycols is etherified with, for example, methyl ether, ethyl ether, propyl ether, glycidyl ether or the like.

Specifically, polyethylene glycol monomethyl ether, polyethylene glycol dimethyl ether, polypropylene glycol dimethyl ether, polyisobutylene glycol dimethyl ether, polyethylene glycol diethyl ether, polyethylene glycol monoethyl ether, polyethylene glycol dibutyl ether, polyethylene glycol monobutyl ether, polyethylene glycol diether. Glycidyl ether,
Polyethylene polypropylene glycol dimethyl ether, glycerin polyethylene glycol trimethyl ether, pentaerythritol polyethylene glycol trimethyl ether, pentitol polyethylene glycol pentamethyl ether, sorbitol polyethylene glycol hexamethyl ether and the like are used. The organic polymer used in the present invention may be a partially or wholly cyclic polymer, such as cyclic polyether and cyclic polyester.

Examples of the solvent that can be added include alcohol solvents, ketone solvents, amide solvents and ester solvents. Here, as the alcohol solvent, methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, sec-butanol, t-butanol, n-pentanol, i-pentanol, 2-methyl are used. Butanol, s
ec-pentanol, t-pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, sec-hexanol, 2-ethylbutanol, s
ec-heptanol, heptanol-3, n-octanol, 2-ethylhexanol, sec-octanol, n-nonyl alcohol, 2,6-dimethylheptanol-4, n-decanol, sec-undecyl alcohol, trimethylnonyl alcohol, monoalcoholic solvents such as sec-tetradecyl alcohol, sec-heptadecyl alcohol, phenol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol and diacetone alcohol;

Ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, pentanediol-2,4,2-methylpentanediol-2,
4, hexanediol-2,5, heptanediol-
Polyhydric alcohol solvents such as 2,4,2-ethylhexanediol-1,3, diethylene glycol, dipropylene glycol, triethylene glycol and tripropylene glycol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl Ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monophenyl ether,
Ethylene glycol mono-2-ethylbutyl ether,
Diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether , Dipropylene glycol monoethyl ether,
Examples thereof include polyhydric alcohol partial ether solvents such as dipropylene glycol monopropyl ether. These alcohol solvents may be used alone or in combination.
More than one species may be used simultaneously.

As the ketone solvent, acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-
n-butyl ketone, diethyl ketone, methyl-i-butyl ketone, methyl-n-pentyl ketone, ethyl-n-
Butyl ketone, methyl-n-hexyl ketone, di-i-
Butyl ketone, trimethylnonanone, cyclohexanone, 2-hexanone, methylcyclohexanone, 2,4
-Pentanedione, acetonylacetone, acetophenone, fenchon, etc., acetylacetone, 2,
4-hexanedione, 2,4-heptanedione, 3,5
-Heptanedione, 2,4-octanedione, 3,5-
Octanedione, 2,4-nonanedione, 3,5-nonanedione, 5-methyl-2,4-hexanedione, 2,
2,6,6-tetramethyl-3,5-heptanedione,
Examples include β-diketones such as 1,1,1,5,5,5-hexafluoro-2,4-heptanone. These ketone solvents may be used either individually or in combination of two or more.

As the amide solvent, formamide, N
-Methylformamide, N, N-dimethylformamide, N-ethylformamide, N, N-diethylformamide, acetamide, N-methylacetamide, N,
N-dimethylacetamide, N-ethylacetamide,
Examples include N, N-diethylacetamide, N-methylpropionamide, N-methylpyrrolidone, N-formylmorpholine, N-formylpiperidine, N-formylpyrrolidine, N-acetylmorpholine, N-acetylpiperidine, N-acetylpyrrolidine and the like. To be These amide solvents may be used either individually or in combination of two or more.

Ester solvents include diethyl carbonate, ethylene carbonate, propylene carbonate, diethyl carbonate, methyl acetate, ethyl acetate, γ-butyrolactone, γ.
-Valerolactone, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, sec-butyl acetate, n-pentyl acetate, sec-pentyl acetate, 3-methoxybutyl acetate, methylpentyl acetate, acetic acid 2-ethylbutyl, 2-ethylhexyl acetate, benzyl acetate,
Cyclohexyl acetate, methyl cyclohexyl acetate, n-nonyl acetate, methyl acetoacetate, ethyl acetoacetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monoacetate
n-butyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, glycol diacetate, acetic acid Methoxytriglycol, ethyl propionate, n-butyl propionate, i-amyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate, n-butyl lactate, n-amyl lactate, malonic acid Examples thereof include diethyl, dimethyl phthalate, and diethyl phthalate. These ester solvents are 1
One kind or two or more kinds may be used at the same time.

Solvents such as alcohol solvents, ketone solvents, amide solvents and ester solvents can be used alone or in admixture of two or more. Ingredient A,
A catalyst may be used when the components B and C are hydrolyzed and condensed. Examples of the catalyst used at this time include ion exchange resins, organic acids, inorganic acids, organic bases and inorganic bases. As the organic acid, for example, acetic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, oxalic acid,
Maleic acid, methylmalonic acid, adipic acid, sebacic acid, gallic acid, butyric acid, meritic acid, arachidonic acid, shikimic acid, 2-ethylhexanoic acid, oleic acid, stearic acid, linoleic acid, linoleic acid, salicylic acid, benzoic acid, p-aminobenzoic acid, p-toluenesulfonic acid, benzenesulfonic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoroacetic acid, formic acid, lactic acid, malonic acid, sulfonic acid, phthalic acid, fumaric acid, citric acid, tartaric acid, etc. Can be mentioned. Examples of the inorganic acid include hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid, phosphoric acid, boric acid and the like.

Examples of the organic base include pyridine, pyrrole, piperazine, pyrrolidine, piperidine, picoline, trimethylamine, triethylamine, monoethanolamine, diethanolamine, dimethylmonoethanolamine, monomethyldiethanolamine, triethanolamine, diazabicyclooclan, Examples thereof include diazabicyclononane, diazabicycloundecene, tetramethylammonium hydroxide and the like. Examples of the inorganic base include ammonia, sodium hydroxide, potassium hydroxide, barium hydroxide, calcium hydroxide and the like. An acid, a base generator, etc. can also be added. A reaction in which two or more kinds of catalysts are used stepwise, a mixed reaction, and the like can also be used.

Next, a method for preparing the insulating film-forming composition of the present invention will be described. The method for adjusting the composition for forming an insulating film of the present invention to the required composition is usually a component A, a component B,
It comprises a synthesis step of reacting the component C, a removal step of removing a solvent, water and other excess or unnecessary components, a preparation step of adding an organic polymer, a solvent, water and other components, and a filtration step. As a typical example, a mixture of component A, component B and component C is added with water and a catalyst for hydrolysis / condensation in the first step, and an organic polymer and water are used in the second step. Is added, and water and the solvent are once removed in the third step, and then the solvent and water are added in the required amounts in the fourth step. This is a typical example, and it is also possible to add a necessary step such as a filtration step, omit an unnecessary step, or perform a specific step multiple times.

A particularly preferred method will be described in detail with reference to the case where an ion exchange resin is used as a catalyst.
First, as a first step, a mixture of water and an ion exchange resin is added dropwise to a mixture of component A, component B, and component C to cause a reaction. Then, only the ion exchange resin is removed by filtration. Next, as a second step, an organic polymer is added.
Next, as a third step, a predetermined amount of excess synthetic solvent, water, or both are removed. Next, in a fourth step, a solvent, water, or both are added to bring the composition to a predetermined value. According to this preparation method, a composition having excellent uniformity can be easily obtained.

The method for preparing the insulating film-forming composition of the present invention is not limited to the above method. If necessary, a suitable method can be selected from a plurality of methods in each step. The method is illustrated below. Examples of the method of adding water to the components A, B, and C include a method of adding water or a mixture of water at once, a method of continuously adding, and a method of intermittently adding. Conversely, component A, component B, and component C may be added to water. Also, it may be added by mixing with a solvent, an organic polymer or the like.

The hydrolysis / condensation reaction temperature of the components A, B and C can be usually 0 to 100 ° C., and the temperature can be changed continuously or intermittently. For example 3
A method of adding water while maintaining it at 0 ° C., stirring at 50 ° C. to carry out a hydrolysis / condensation reaction, a method of continuously dropping water in the process of heating from 30 ° C. to 50 ° C., etc. are used. .
As a method of adding a catalyst added as necessary, for example, a method of directly mixing the catalyst, water to which the catalyst is added,
There is a method of adding what is previously dispersed or dissolved in a solvent, an organic polymer or the like. Specifically, a method of wetting the ion exchange resin with water and adding it at the same time as water, a method of mixing the water-wet ion exchange resin with ethanol and adding it, a method of directly dropping an aqueous phosphoric acid solution, and the like can be mentioned.

When an ion exchange resin is used as the catalyst, either a cation exchange resin or an anion exchange resin can be used. For example, a strong acid cation exchange resin having a sulfonic acid group, a weak acid cation exchange resin having a carboxylic acid group, a basic anion exchange resin having an amino group and the like can be mentioned. Specifically, Organo Amberlite IR120B, A26, MB2, etc., Organo Amberlyst RCP-160M, 15DR
Y, 15WET, Mitsubishi Chemical's Diaion PK2
20, SK112, WK100, PA412 and the like, DOWEX50W-X2, 50W-X4, manufactured by Dow Chemical Co.,
50W-X6, 50W-X8, etc. can be used. The ion exchange resin can be used in a dry state, a wet state with water, a wet state with an organic solvent, or the like.

When the composition of the present invention was prepared, the components A, B and C were separately hydrolyzed and condensed,
You may mix. Specifically, a method in which the component A is hydrolyzed / condensed, the component B is hydrolyzed / condensed, and the component C is hydrolyzed / condensed, and the component A and the component A are mixed. A method in which a mixture obtained by subjecting a mixture of component B to hydrolysis / condensation reaction and a mixture obtained by subjecting component C to hydrolysis / condensation are mixed, and a mixture obtained by subjecting a mixture of component A and component C to hydrolysis / condensation reaction and component B are hydrolyzed Examples thereof include a method of mixing the decomposed / condensed reaction, and a method of mixing a mixture of the component B and the component C by a hydrolysis / condensation reaction and a mixture of the component A's a hydrolyzed / condensed reaction. If necessary, the separately reacted products may be mixed and then further hydrolyzed and condensed.

Mixture of component A, component B and component C, or a mixture of component A, component B and component C reacted separately, and mixing component A, component B and component C in one or more types. Is also good. If necessary, a mixture of Component A, Component B, and Component C, or a mixture of Component A, Component B, and Component C separately reacted with Component A, Component B, and Component C, and then further hydrolyzed and condensed. You may let me. Ingredient A, Ingredient B, Ingredient C
The hydrolysis / dehydration condensation may be performed in the presence of a solvent and an organic polymer in addition to the alcohol produced by hydrolysis. Usually, the weight average molecular weight of the hydrolyzed / dehydrated condensate of the component A, the component B and the component C in the composition of the present invention is 300 to 300 in terms of polyethylene glycol by GPC.
It is 1,000,000.

In order to obtain the desired composition of the composition of the present invention, water and a low boiling solvent can be removed. Specific examples thereof include a vacuum distillation method, a precision distillation method, an Arthur distillation method, a distillation method such as a thin film distillation method, an extraction method, and an ultrafiltration method. The distillation method can be carried out either under atmospheric pressure or under reduced pressure. However, under normal pressure, the distillation temperature generally rises, and the silica precursor may solidify during distillation. It is preferable to distill off with. If necessary, an organic polymer, a solvent and the like can be mixed as a gelation inhibitor and a viscosity reducing agent before and / or after the distillation. The distillation temperature is 0 to 100 ° C.

Water is essential for the hydrolysis / condensation of the components A, B, and C, but any organic polymer, solvent, water, etc. for making the composition of the present invention into a desired composition can be prepared. It can be added also at a stage, and can be added alone or in a mixture of two or more kinds. Further, it may be added at once or may be added twice or more.
If necessary, the composition of the present invention can be filtered in any step using a filter. For example, after performing a hydrolysis / condensation reaction using an ion exchange resin, vacuum filtration using a PTFE membrane filter having a pore size of 10 μm is performed, and a pore size of 0.
For example, pressure filtration using a polyethylene cartridge filter of 05 μm can be performed.

Next, a method for obtaining a low dielectric constant material by using the insulating film forming composition of the present invention will be described. An object of the present invention is to obtain a low dielectric constant material used for a semiconductor device, and a substrate usually used in a semiconductor device, such as a silicon substrate or a compound semiconductor substrate, on which an insulating film such as a silicon oxide film or a silicon nitride film is formed. It is preferably applied on a film, aluminum, copper, tungsten, titanium, tantalum, or a nitride thereof. The most commonly used coating method is the spin coating method (spin coating), but the method preferably used in the present invention is not necessarily limited to spin coating.

After applying the composition for forming an insulating film, baking is performed. Firing may be performed in one step or in multiple steps. Generally, after performing the first-stage heating at a temperature of about 70 ° C. to 150 ° C. using a hot plate, 1
Firing at about 50 ° C. to 400 ° C. is performed in one or multiple steps. In addition, the firing can be performed not only with a hot plate but also with an electric furnace or a lamp heating furnace. As a specific method, suitable conditions can be selected according to the composition of the insulating film forming composition and the like. For example, when polyethylene glycol dimethyl ether having a number average molecular weight of 700 or more is used as the organic polymer, once the heating plate is heated in two or more steps in the range of 150 ° C to 300 ° C, the organic polymer is heated to 400 ° C. Can be used.

[0053]

EXAMPLES The following examples are used to carry out the present invention.
The form will be described in more detail. Of the solid content and the organic polymer concentration in the composition
Regulation: Solid content concentration is the total amount of alkoxysilane charged
Was calculated from the weight of the case of conversion into silica. On silica
The weight when converted is, for example, alkoxysilane
Then, when 1 mol of tetramethoxysilane is used, this is
1 mol of SiO if completely oxidized₂Convert to silica
Therefore, its weight is 60.1 g. Multiple arcoki
When silane is used, it is calculated from each mole fraction.
The total weight of the silicas is the weight converted to silica.
The organic polymer concentration is calculated from the weight of the charged organic polymer.
It was calculated. Determination of the amount of water and ethanol in a composition: the present invention
As an internal standard in 1 ml of the coating composition of
Gas chromatography by Shimadzu
Water and ethanol in the coating composition using GC-7A
The amount of leu was measured. Gaskuropac as column
Using k56, the temperature program was introduced at 100 ° C, 2 mi
n holding, temperature rising rate 10 ° C / min, final 200 ° C, 16
It was kept at min. TCD is used for the detector, and it is made separately.
From the area ratio with the internal standard,
The amount of rucor was calculated. Weight of water relative to silica precursor
The ratio is based on the weight of the silica precursor, for convenience,
If the total amount of silane is converted to silica,
It was calculated from the weight of water obtained by the gas chromatography method. Siri
When converted to mosquito, the weight is, for example, alkoxysila.
If 1 mol of tetramethoxysilane is used as the amine, 1
Mole of SiO ₂Since it is converted to silica, its weight is 6
It is 0.1 g. When using multiple alkoxysilanes
Is the sum of silica calculated from the respective mole fractions.
The weight is the weight converted to silica.

Specific permittivity: low resistivity (0.01 to 0.1
Ω) A low dielectric constant film using the composition of the present invention was formed on a silicon wafer, and the relative dielectric constant (k) at 1 MHz was determined using an SSM 495 type automatic mercury CV measuring device. Chemical mechanical polishing (CMP) test: A thin film made of a low dielectric constant material formed by using a composition for forming an insulating film is used as a polishing slurry and a polishing pad while applying a pressure of 4.8 psi at a rotational speed of 150 rpm for 2 minutes. Polished for minutes. The surface of the low dielectric constant film after polishing was observed visually and with an optical microscope to examine the presence or absence of peeling and the extent of peeling. The polishing slurry is silica sol type (silica concentration 13%, primary particle size 30n
m, pH = 10.8 (ammoniacal)) was used. As the polishing pad, a polyurethane foam pad (thickness: about 1.8 mm) was used. ◯: No scratch or peeling on the polished surface ×: Peeling or scratch on the polished surface

Storage stability: The film-forming composition of the present invention was sealed in a glass bottle and left at 23 ° C. for 1 month. The sample before and after standing was applied under spin coating conditions of 2000 rpm for 60 seconds, and the film thickness when baked by the method described in Example 1 above was measured by a spectroscopic ellipsometer (UVISE manufactured by Jovin Yvon).
L) was measured using a SiO ₂ -void model, and the rate of change {[(thickness of sample after leaving-thickness of sample before leaving) / thickness of sample before leaving] × 100} It was calculated and evaluated according to the following criteria. ◯: Change rate of less than 5% ×: Change rate of 5% or more

Freezing stability: glass bottles were tightly stoppered, -20 ° C
After standing still for 7 days, the appearance of the contents was observed. ◯: Transparent and uniform solution Δ: Phase-separated solution ×: Solid Young's modulus: Measured with Nano Indenter DCM manufactured by MTS Systems Corporation. The measurement method was as follows: A Berkovich type diamond indenter was pressed into a sample, and after a certain load was applied, the load was removed and the load-displacement curve was obtained by monitoring the displacement. The surface was recognized under the condition that the contact stiffness was 200 N / m. The hardness is calculated by the following formula.

H = P / A Here, P is the applied load, and the contact area A is a function of the contact depth hc and is experimentally obtained by the following equation. A = 24.56 hc ² This contact depth has the following relationship with the displacement h of the indenter. hc = h-εP / S where ε is 0.75 and S is the initial slope of the unloading curve.
The Young's modulus was calculated by Sneddon's formula. Er = (√π · S) / 2√A Here, the composite elastic modulus Er is expressed by the following equation. Er = [(1-νs2) / Es + (1-νi2) / Ei]-
1 Here, ν represents Poisson's ratio, subscript S represents a sample, and i represents an indenter. In the present invention, ν i = 0.07, Ei = 1141 G
Pa, and the Poisson's ratio of this material is unknown, but νs =
The Young's modulus Es of the sample was calculated as 0.18. The Young's modulus in the present invention is 0.5
It was measured at a film thickness of μ to 1 μm.

Uniformity of film thickness: The low dielectric constant film prepared from the composition of the present invention was visually observed, and the results were evaluated as follows. ◯: A uniform film without interference fringes, radial fringes, etc. Δ: A film with in-plane interference fringes ×: Radial fringe heat resistance: A low dielectric constant film prepared by using the composition of the present invention is manufactured by Shimadzu Corporation. Using thermogravimetric analyzer TA-50, flow rate 40m
The weight reduction rate was measured after holding at 425 ° C. for 2 hours in an Ar atmosphere of 1 / min.

Film Thickness: Spectroscopic Ellipsometer (Jobin Yvon
Manufactured by UVISEL) using a SiO ₂ -void model. Trace metal analysis: About 10 g of the composition for forming an insulating film was put in a platinum crucible and precisely weighed. After evaporating the solvent with a heater, the composition was heated in an oxygen stream at 500 ° C. for 2 hours. The residue obtained by adding 48% hydrofluoric acid was dissolved in nitric acid. The amounts of sodium and iron in the test solution prepared by adjusting the volume of this to 20 cc with water were analyzed by a flameless atomic absorption spectrophotometer manufactured by Hitachi Ltd. and converted into the concentration in the composition for forming an insulating film.

[0060]

Example 1 As a first step, 71.3 g of methyltriethoxysilane, 70.9 g of 1,2-bistriethoxysilylethane and 41.7 g of tetraethoxysilane were mixed, and 57.6 g of water and wet with water were mixed in the mixture. Sulfonic acid type cation exchange resin (Amberlist RCP-1 manufactured by Organo Corporation)
A mixture of 60 ml of 12 ml (containing 9.2 g of water) was added dropwise at room temperature. After the dropping, the mixture was stirred at 50 ° C. for 4 hours to carry out hydrolysis and dehydration condensation reaction, and the ion exchange resin was filtered off.

Next, as a second step, the filtered solution 10
In 0 g, as an organic polymer, polyethylene glycol dimethyl ether (number average molecular weight Mn = 600: 80 w
t% aqueous solution) 33.8 g was added. As a third step, a reduced pressure treatment was carried out at 50 ° C. for 30 minutes with a rotary evaporator to distill off water and ethanol.
Then, as a fourth step, 83.6 g of propylene glycol monomethyl ether and 108.9 of water were added to the distillation residue.
g and ethanol 3.7g, solid content concentration 10wt%, organic polymer concentration 10wt%, water 30w
A composition of the present invention was made at t% and 4 wt% ethanol.

[0062]

Example 2 Compared to the procedure of Example 1, the amount added to the distillation residue was 174.6 g of propylene glycol monomethyl ether, 115.5 g of water and 1.9 of ethanol.
A solid content concentration of 5 was obtained by the same operation as in Example 1 except that g was changed to g.
A composition of the present invention was made having wt%, organic polymer concentration 5 wt%, water 30 wt% and ethanol 4 wt%.

Example 3 Compared to the operation of Example 1, except that the amount added to the distillation residue was changed to 4.9 g of propylene glycol monomethyl ether and 38.4 g of water, and ethanol was not added. 1 same operation, solid content concentration 14w
A composition of the present invention was prepared having t%, organic polymer concentration 14 wt%, water 30 wt% and ethanol 4 wt%.

[0063]

Example 4 Compared to the operation of Example 1, polyethylene glycol dimethyl ether (number average molecular weight Mn = 60
(0:80 wt% aqueous solution), except that the addition amount was changed to 20.3 g, the solid content concentration was 10 wt%,
A composition of the present invention having an organic polymer concentration of 6 wt%, water of 30 wt% and ethanol of 4 wt% was prepared.

Example 5 Compared to the procedure of Example 1, the procedure of Example 1 was repeated except that the additive added to the distillation residue was changed from propylene glycol monomethyl ether to ethyl lactate, and the solid content concentration was 10 wt%. , Organic polymer concentration 10wt
%, 30 wt% water and 4 wt% ethanol were made.

[0064]

Example 6 The same as Example 5 except that the amount added to the distillation residue was changed to 88.6 g of ethyl lactate, 9.5 g of water and 1.9 g of ethanol in comparison with the operation of Example 5. By operation, solid concentration 10wt%, organic polymer concentration 10wt
%, 7 wt% water and 4 wt% ethanol were prepared.

[Example 7] The same as Example 5 except that the amount added to the distillation residue was changed to 82.6 g of ethyl lactate, 15.5 g of water and 1.9 g of ethanol in comparison with the operation of Example 5. By operation, solid concentration 10t%, organic polymer concentration 10wt
%, Water 10 wt% and ethanol 4 wt% were prepared.

[0065]

Example 8 Compared to the procedure of Example 1, the amounts of methyltriethoxysilane and 1,2-bistriethoxysilylethane used were 53.5 g and 88.6 g, respectively.
A composition of the present invention was prepared in the same manner as in Example 1, except that

[Example 9] The same procedure as in Example 1 was carried out except that 51.3 g of bistrimethoxysilylmethane was used instead of 70.9 g of 1,2-bistriethoxysilylethane in comparison with the operation of Example 1. A composition of the invention was made.

The above-mentioned compositions for forming an insulating film obtained in Examples 1 to 9 were tested for storage stability, liquid uniformity, and freezing stability. In addition, a low dielectric constant material was prepared as follows using this insulating film forming composition.
After dropping 5 cc of the composition for forming an insulating film on the silicon substrate,
The coating was applied by a spin coating method by shaking off at 2000 rpm. Next, this was heated at 120 ° C. in air for 1 minute to remove the solvent. The processes up to this point were performed using a coating device Cleantrack ACT8 SOD manufactured by Tokyo Electron Limited. Next, this is placed in nitrogen at 1 atm from 150 ° C to 400 ° C.
After heating at a temperature rising rate of 10 ° C. per minute, the temperature was kept at 400 ° C. and baked for 30 minutes to obtain a thin film made of a low dielectric constant material. This treatment is performed using a vertical heat treatment furnace (VF-1 manufactured by Koyo Lindbergh Co., Ltd.
000 LP).

[0067]

Example 10 A thin film made of a low dielectric constant material was obtained by using the composition of the present invention prepared in Example 3 in the same manner as in Examples 1 to 9 except that the coating rotation speed was 1000 rpm. It was

Example 11 Example 3 was repeated except that propylene glycol methyl ether was changed to ethyl lactate in Example 3.
A composition of the present invention was prepared in the same manner as in. This composition was applied to Examples 1 to 9 except that the coating speed was 1000 rpm.
Using the same method as above, a thin film made of a low dielectric constant material was obtained. The low dielectric constant material thin film thus obtained was evaluated for film thickness, relative dielectric constant, Young's modulus, CMP resistance, heat resistance evaluation, and film thickness uniformity. The results are shown in Table 1.

[0068]

Comparative Example 1-1 Same as Example 1 except that the amounts of methyltriethoxysilane and 1,2-bistriethoxysilylethane used were 107.0 g and 35.5 g, respectively, as compared with the operation of Example 1. A composition for forming an insulating film was prepared by the operation of. Using this composition, a thin film made of a low dielectric constant material was obtained in the same manner as in Example 1. When the Young's modulus of this thin film was measured, it was 1.4 GPa.

[0069]

[Comparative Example 1-2] Compared with the operation of Example 1, the amounts of methyltriethoxysilane and 1,2-bistriethoxysilylethane used were 107.0 g and 70.9 g, respectively, and tetraethoxysilane was used. Example 1 except not
A composition for forming an insulating film was prepared by the same operation. Using this composition, a thin film made of a low dielectric constant material was obtained in the same manner as in Example 1. The Young's modulus of this thin film was measured and found to be 1.8 GPa.

[0070]

[Comparative Example 1-3] Compared with the operation of Example 1, the amounts of methyltriethoxysilane and 1,2-bistriethoxysilylethane used were changed to 71.3 g and 106.4 g, respectively, and tetraethoxysilane was used. Example 1 except not
A composition for forming an insulating film was prepared by the same operation. Using this composition, a thin film made of a low dielectric constant material was obtained in the same manner as in Example 1. The Young's modulus of this thin film was measured and found to be 1.8 GPa. Regarding the thin films of the low dielectric constant materials of Comparative Examples 1-1 to 1-3, the Young's modulus lower than those of Examples 1 to 11 was obtained.

[0071]

[Comparative Example 1-4] Compared with the operation of Example 1, the amounts of methyltriethoxysilane, 1,2-bistriethoxysilylethane and tetraethoxysilane used were each 1
Except for 7.8g, 124.1g and 41.7g,
A composition for forming an insulating film was prepared in the same manner as in Example 1. Since a part of the components of this composition for forming an insulating film gelled at the synthesis stage, it was not possible to obtain a thin film made of a low dielectric constant material by coating and baking.

[0072]

[Comparative Example 1-5] Compared to the operation of Example 1, the amounts of methyltriethoxysilane, 1,2-bistriethoxysilylethane and tetraethoxysilane used were each 1
An insulating film forming composition was prepared in the same manner as in Example 1 except that the amounts were changed to 7.8 g, 88.6 g and 83.4 g.
Since a part of the components of this composition for forming an insulating film gelled at the synthesis stage, it was not possible to obtain a thin film made of a low dielectric constant material by coating and baking.

[0073]

[Comparative Example 1-6] Compared to the operation of Example 1, the amounts of methyltriethoxysilane, 1,2-bistriethoxysilylethane and tetraethoxysilane used were each 7
Except for 1.3g, 141.8g and 83.4g,
A composition for forming an insulating film was prepared in the same manner as in Example 1. When the storage stability of this insulating film forming composition was evaluated, as shown in Table 1, Examples 1 to 1
The results were inferior to those of the insulating film-forming compositions obtained up to 1.

[0074]

Comparative Example 2-1 Compared to the procedure of Example 1, Example 1 was repeated except that the added organic polymer was changed to polyethylene glycol-α-methyl ether-ω-pentyl ether.
A composition for forming an insulating film was prepared by the same operation. Using this composition, a thin film made of a low dielectric constant material was obtained in the same manner as in Example 1. While the thin films made of the low dielectric constant materials obtained in Examples 1 to 11 did not generate cracks up to a thickness of 3.5 μm or more, the thin film of this comparative example had a thickness of 1.5 μm. A crack has occurred.

[0075]

[Comparative Example 2-2] Compared to the operation of Example 1, the amounts of methyltriethoxysilane, 1,2-bistriethoxysilylethane and tetraethoxysilane used were each 8
An insulating film-forming composition was prepared in the same manner as in Example 1, except that the amounts were changed to 9.1 g, 53.2 g, and 41.7 g.
Using this composition, a thin film made of a low dielectric constant material was obtained in the same manner as in Example 1. The thin films made of the low dielectric constant materials obtained in Examples 1 to 11 are all 3.5.
While no cracks were generated up to a film thickness of μm or more, the thin film of this comparative example was cracked at 1.4 μm.

[0076]

[Comparative Example 3-1] Compared with the operation of Example 1, the number average molecular weight of the added organic polymer was changed from Mn600 to Mn25.
A composition for forming an insulating film was prepared in the same manner as in Example 1 except that the composition was changed to 0. Using this composition, a thin film made of a low dielectric constant material was obtained in the same manner as in Example 1. When the relative dielectric constant of this thin film was measured, a value of 2.48, which was significantly higher than that of the thin films made of the low dielectric constant materials obtained in Examples 1 to 11, was obtained.

[0077]

[Comparative Example 3-2] An insulating film-forming composition was prepared in the same manner as in Example 1 except that the number average molecular weight of the added organic polymer was changed to Mn = 1200 as compared with the operation in Example 1. did. Using this composition, a thin film made of a low dielectric constant material was obtained in the same manner as in Example 1. When the heat resistance of this thin film was measured, a value of 1.2% was obtained.
This value is 2 to 3 times worse than the thin films made of the low dielectric constant materials obtained in Examples 1 to 11.

[0078]

[Comparative Example 4-1] Compared with the operation of Example 1, 1,2-
A composition for forming an insulating film was prepared in the same manner as in Example 1 except that 1,6-bistriethoxysilylhexane was used instead of bistriethoxysilylethane. When the storage stability of this composition was measured, the results were inferior to those of the insulating film forming compositions obtained in Examples 1 to 11.

[0079]

[Comparative Example 5-1] Compared with the operation of Example 1, the addition amount to the distillation residue was 94.6 g of propylene glycol monomethyl ether, 3.5 g of water and 1.9 g of ethanol.
With the same operation as in Example 1 except that the solid content concentration was changed to 10
A composition for forming an insulating film having a wt%, an organic polymer concentration of 10 wt%, water of 4 wt% and ethanol of 4 wt% was prepared. Using this composition, a thin film made of a low dielectric constant material was obtained in the same manner as in Example 1. Table 1 shows the results of measuring the film thickness uniformity of this thin film. Radial non-uniformity of film thickness (so-called striation) occurred in this thin film. As a result, the uniformity is significantly deteriorated as compared with the thin films made of the low dielectric constant materials obtained in Examples 1 to 11.

[0080]

[Comparative Example 5-2] Compared with the operation of Example 1, the addition amount to the distillation residue was 2.6 g of propylene glycol monomethyl ether, 95.5 g of water and 1.9 g of ethanol.
With the same operation as in Example 1 except that the solid content concentration was changed to 10
A composition for forming an insulating film having a wt%, an organic polymer concentration of 10 wt%, water of 50 wt% and ethanol of 4 wt% was prepared. Using this composition, a thin film made of a low dielectric constant material was obtained in the same manner as in Example 1. Table 1 shows the results of measuring the film thickness uniformity of this thin film. Striation did not occur in this thin film, but the uniformity was significantly deteriorated as compared with the thin films made of the low dielectric constant materials obtained in Examples 1 to 11. It is presumed that this is because the ratio of water having a large heat of vaporization is high, so that the temperature distribution on the substrate is likely to occur during coating, which causes nonuniformity of the film thickness.

[0081]

COMPARATIVE EXAMPLE 6-1 Compared with the procedure of Example 1, the procedure of Example 1 was repeated except that the additive added to the distillation residue was changed from propylene glycol monomethyl ether to propylene glycol methyl ether acetate. Solid content concentration 10wt%, organic polymer concentration 10wt%, water 30w
An insulating film forming composition containing t% and ethanol 4 wt% was prepared. When this composition was prepared, white turbidity was generated due to solidification of the composition, so that a thin film made of a low dielectric constant material could not be formed.

[0082]

[Comparative Example 6-2] Compared with the operation of Example 1, Example 1 was repeated except that the additive added to the distillation residue was changed from propylene glycol monomethyl ether to cyclopentanone.
By the same operation, solid content concentration 10 wt%, organic polymer concentration 10 wt%, water 30 wt% and ethanol 4 wt%
The following composition for forming an insulating film was prepared. The results of measuring the freeze stability of this composition are shown in Table 1. Only inferior results were obtained as compared with the insulating film forming compositions obtained in Examples 1 to 11. Therefore, when this solvent is used, the temperature range suitable for storing the insulating film forming composition is narrowed.

[0083]

Comparative Example 6-3 Compared to the operation of Example 1, the procedure of Example 1 was repeated, except that the additive added to the distillation residue was changed from propylene glycol monomethyl ether to ethanol. %, Organic polymer concentration 10
An insulating film forming composition containing wt%, water 30 wt% and ethanol 4 wt% was prepared. With this composition,
In the same manner as in Example 1, a thin film made of a low dielectric constant material was obtained. Significant striation occurred in this thin film. The film thickness uniformity was 21%, which was significantly worse than the thin films obtained in Examples 1 to 11.

[0084]

[Comparative Example 7-1] Methyltriethoxysilane 71.3
g, 1,2-bistriethoxysilylethane 70.9
g, and 41.7 g of tetraethoxysilane are mixed, and 66.8 g of water and 0.06 g of 0.01 mol / l sulfuric acid are mixed therein.
The mixture of was added dropwise at room temperature. After the dropping, the mixture was stirred at 50 ° C. for 4 hours to carry out hydrolysis and dehydration condensation reaction to obtain an insulating film forming composition. Table 1 shows the results of measuring the concentrations of trace metals contained in this composition by the same method as in Example 1. Compared with Example 1, sodium increased about 100 times and iron increased about 6 times.

[0085]

[Comparative Example 8-1] Methyltriethoxysilane 71.3
g, 1,2-bistriethoxysilylethane 70.9
g and 41.7 g of tetraethoxysilane are mixed, and propylene glycol monomethyl ether 200.
0 g was added, and a mixture of 57.6 g of water and 12 ml of a water-wet sulfonic acid type cation exchange resin (Amberlyst RCP-160M manufactured by Organo Corporation) (containing 9.2 g of water) was added dropwise at room temperature. After the dropping, the mixture was stirred at 50 ° C. for 4 hours to carry out hydrolysis and dehydration condensation reaction, and the ion exchange resin was filtered off. 18.8 g of polyethylene glycol dimethyl ether (number average molecular weight Mn = 600: 80 wt% aqueous solution) as an organic polymer in 100 g of the filtered solution
From the one with the addition of 50 on a rotary evaporator.
Water and ethanol were distilled off by performing a reduced pressure treatment at 30 ° C. for 30 minutes. Propylene glycol monomethyl ether (48.0 g) and water (42.2 g) and ethanol (4.6 g) were added to the distillation residue to give a solid concentration of 10 wt.
%, Organic polymer concentration 10 wt%, water 30 wt%, and ethanol 4 wt%, an insulating film forming composition was prepared.
Using this composition, a thin film made of a low dielectric constant material was obtained in the same manner as in Example 1. When the CMP resistance of this thin film was measured, it was significantly deteriorated as compared with the thin films obtained in Examples 1 to 11.

[0086]

[Table 1]

[0087]

According to the present invention, a composition for forming an insulating film, which is suitable for forming a low dielectric constant material having excellent mechanical properties such as CMP resistance and crack resistance and excellent coating properties, is provided. A composition for forming an insulating film having excellent storage stability can be obtained.

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Claims (8)

[Claims] 1. An insulating film forming composition comprising an organic polymer and the following components A, B and C, and / or a hydrolyzate or condensate of these components, wherein the components A, B and C, and / Or the silicon atom derived from the hydrolyzate or condensate of these components has a number of silicon atoms derived from the component A and / or its hydrolyzate or condensate in the atomic ratio of 2 respectively.
0% or more and 45% or less, the silicon atom of component B is 30% or more and 60% or less, and the silicon atom of component C is 10% or more and 30% or more
% Or less, the composition for forming an insulating film. Component A: R ₁ Si (OR ₂ ) ₃ (wherein R ₁ and R ₂
A monovalent organic group) Component _{B: (R 3 O) 3 Si} -R 5 -Si (OR 4)
₃ (In the formula, R ₃ and R ₄ are monovalent organic groups, R ₅ is a divalent organic group) Component C: Si (OR ₆ ) ₄ (In the formula, R ₆ is a monovalent organic group) 2. The insulating film-forming composition according to claim 1, wherein the organic polymer is polyethylene glycol dimethyl ether. 3. The insulating film-forming composition according to claim 2, wherein the number average molecular weight of polyethylene glycol dimethyl ether is 400 or more and 1000 or less. 4. The structure of component B is (R ₃ O) ₃ Si— (C
_{H 2) m -Si (OR 4} ) 3 ( where, m = 1 or 2)
The insulating film-forming composition according to claim 2 or 3, wherein 5. The insulating film-forming composition according to claim 1, which contains 5% or more and 40% or less by weight of water relative to the entire insulating film-forming composition. 6. The insulating film-forming composition according to claim 1, which contains at least one of propylene glycol methyl ether, its ester, and lactate ester. 7. The insulating film-forming composition according to claim 1, wherein the hydrolysis and condensation reactions of the components A, B and C are carried out in the presence of an ion exchange resin. . 8. The insulating film formation according to claim 1, wherein the hydrolysis and condensation reactions of the component A, the component B and the component C are carried out in an alcohol having a boiling point of 100 ° C. or lower. Composition.