JP2001035256A - Insulating material composition and insulating material using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insulating material composition showing an extremely low dielectric constant and satisfactory insulation performance, superior in heat resistance and useful for electric appliances, electronic apparatuses and semiconductor equipment, and provide an insulating material using it. SOLUTION: This insulating material composition has a high polymer (A) made to have a low molecular weight by optical irradiation and a heat resistant material or its precursor as essential components. After forming a film on a base with this insulating material composition, the component (A) is made to have a low molecular weight through photodecomposition, and a fine air gap is formed in the film by vaporizing it by heating or by extracting and removing it from a solvent. Thereby, a heat resistant insulating material which is lows in dielectric constant can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulating material, and more particularly to a composition for an insulating material having excellent characteristics for electric / electronic devices and semiconductor devices, and an insulating material using the same. Things.

[0002]

2. Description of the Related Art Among the characteristics required for materials for electric / electronic devices and semiconductor devices, electric characteristics and heat resistance are the most important characteristics. In particular, in recent years, with miniaturization of circuits and speeding up of signals, an insulating material having a low dielectric constant has been required.
An insulating material using a heat-resistant resin is expected as a material for achieving both of these characteristics. For example, conventionally used inorganic insulating materials such as silicon dioxide have high heat resistance, but have a high dielectric constant and the required characteristics are now sophisticated. It is getting. A heat-resistant resin represented by a polyimide resin has excellent electrical properties and heat resistance, and is compatible with both properties.
It is possible and actually used for a coverlay of a printed circuit or a passivation film of a semiconductor device.

[0003] However, in recent years, semiconductors have become more sophisticated,
With the increase in performance, remarkable improvements in electrical characteristics and heat resistance are required, so that a higher-performance insulating material is required. In particular, a low-dielectric material having a dielectric constant of less than 2.5 is expected, and a conventional insulating material does not reach required characteristics. On the other hand, to date, a liquid material having a precursor of a heat-resistant material and a heat-decomposable component has been applied, and this heat-decomposable component has been decomposed by a heating step to form voids. Attempts have been made to reduce the dielectric constant. However, in order to completely decompose and volatilize the thermally decomposable component, a heating step at a high temperature and for a long time is necessary. The problem is that it may not be possible to reduce it effectively.

[0004]

DISCLOSURE OF THE INVENTION The present invention relates to a composition for an insulating material which exhibits an extremely low dielectric constant and good insulating properties by an efficient processing method, and also has excellent heat resistance and an insulating material using the same. The purpose is to provide.

[0005]

Means for Solving the Problems The present inventors have made intensive studies in view of the above-mentioned conventional problems, and as a result, completed the present invention by the following means.

That is, the present invention provides: A composition for an insulating material comprising a polymer (A) whose molecular weight is reduced by light irradiation and a heat-resistant material or its precursor (B) as essential components;

[0007] 2. Heat-resistant material or its precursor (B)
Is a heat-resistant polymer or a heat-resistant polymer precursor,
The composition for an insulating material according to the item,

[0008] 3. Heat-resistant polymer or its precursor (B)
The composition for insulating material according to claim 2, which is a polybenzoxazole or a polybenzoxazole precursor,

4. The composition for an insulating material according to any one of Items 1 to 3, wherein the component (A) is produced by a method having a step of lowering the molecular weight by light irradiation and then volatilizing or extracting the component. An insulating material.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The insulating material composition of the present invention comprises, as essential components, a polymer (A) whose molecular weight is reduced by light irradiation and a heat-resistant material or its precursor (B). . As a component other than the component (A) and the component (B), a solvent can be used, but the component (A) is used as the component (B).
In the case of a liquid that dissolves, the component (A) can also serve as a solvent. In addition to these components, a photosensitizer, an adhesion-imparting agent, a leveling agent, and the like may be added.

The insulating material composition of the present invention can be made into an insulating material by the following steps. First, the component (A) of the composition for insulating material includes the component (A) and the component (B).
In the case where a photosensitizer is used as a component other than the above, the component (A) and the photosensitizer are applied to a substrate using a spin coater or the like under a light illumination at a wavelength having no sensitivity. , Heating and film formation. When the component (B) is a heat-resistant material precursor, the precursor is reacted in this step to form a heat-resistant material. The heating temperature in this step depends on the component (A)
Is in a temperature range in which is not volatilized by thermal decomposition.

Second, when the component (A) and a photosensitizer are used, the photosensitizer irradiates light having a wavelength having sensitivity with an exposure device to photodecompose the component (A). To reduce the molecular weight.

Third, by heating again, the low molecular weight component (A) is volatilized and removed. Alternatively, the low-molecular-weight component (A) is sprayed with a soluble solvent on a substrate using a spin coater, or the low-molecular-weight component (A) is extracted by immersing the substrate in a solvent bath. And remove it. Through the above steps, fine voids are formed, whereby an insulating material having a low dielectric constant can be obtained.

In order to remove the component (A) whose molecular weight has been reduced by volatilization, it is necessary to heat. In this case, the temperature is higher than the temperature at which the component (A) whose molecular weight has been reduced is volatilized, and fine particles are used. In order to avoid collapse of the voids, the heat treatment is performed at a melting point of the heat-resistant material or at a temperature lower than the glass transition temperature when the heat-resistant material is a polymer.

When extracting the low molecular weight component (A) with a solvent, it is necessary to use a solvent in which the heat-resistant material after heating does not dissolve. In the component (B), a heat-resistant material obtained by heating the precursor is generally more preferable because it has good solvent resistance.

Further, in addition to the component (A) and the photosensitizer in the present invention, it is necessary to use a heat-resistant material, a solvent and the like which do not absorb light.

Examples of the polymer (A) whose molecular weight is reduced by light irradiation used in the present invention include polymethyl methacrylate and poly (α-methylstyrene), but are not limited thereto. The molecular weight before lowering the molecular weight is preferably 5,000 or more, and the molecular weight after lowering the molecular weight is preferably 500 or less, but there is a significant difference in volatility or solvent solubility before and after the lowering of the molecular weight. If so, the change in molecular weight need not be limited to the above.

Examples of the heat-resistant material or its precursor (B) used in the present invention include polyimide, polyamic acid,
Examples include, but are not limited to, polyamic acid esters, polyisoimides, polyamideimides, polyamides, bismaleimides, polybenzoxazoles, polyhydroxyamides, polybenzothiazoles, polysiloxanes, polysilsesquioxanes, and polysilazanes. Among them, polybenzoxazole precursors such as polybenzoxazole and polyhydroxyamide are preferable because the resulting insulating material has a low dielectric constant and high heat resistance.

When a solvent is used as a component of the composition for insulating material of the present invention, examples of preferred solvents include N, N
-Dimethylacetamide, N-methyl-2-pyrrolidone, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether, γ-butyrolactone, xylene and the like, but are not limited thereto. Further, two or more of these may be used at the same time.

The resin composition for an insulating material of the present invention is obtained by uniformly mixing a polymer (A) whose molecular weight is reduced by light irradiation and a heat-resistant material or its precursor (B). Component (A) is preferably added in an amount of 5 to 90% by weight based on component (B). More preferably, it is added in the range of 10 to 70%. If it is lower than 5%, the porosity is small, and the dielectric constant does not decrease. If it is higher than 90%, the mechanical strength and adhesiveness are reduced, and the water absorption is increased.

The minute voids formed to reduce the dielectric constant of the insulating material of the present invention preferably have a diameter of 50 n.
m or less, and more preferably an average particle size of 10
nm or less. The ratio of the minute voids is preferably from 5 to 90 vol%, more preferably from 10 to 70 vol%, based on the whole formed material of the insulating material.

Using the insulating material composition of the present invention, the steps of heating and forming a film by the above-described methods, irradiating with light, and removing or removing by volatilizing or extracting the polymer whose molecular weight has been reduced by the irradiation of light. In addition, an insulating material having a low dielectric constant can be formed. Light irradiation can be performed using a deep ultraviolet exposure apparatus or the like using a low-pressure mercury lamp capable of emitting light having a wavelength of about 200 nm as a light source. The heating is preferably performed by a heating device capable of exhausting the volatilized components.

[0023]

EXAMPLES The present invention will be described below in more detail with reference to Examples, but it should not be construed that the invention is limited thereto.

Example 1 (1) Synthesis of polyimide 2,2′-bis (4- (4,4′-aminophenoxy)) was placed in a separable flask equipped with a stirrer, a nitrogen inlet tube, and a raw material inlet. Phenyl) hexafluoropropane 5.1
8 g (0.01 mol) and 9.60 g of 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl
(0.03 mol) was dissolved in 200 g of dried N-methyl-2-pyrrolidone (hereinafter abbreviated as NMP). The solution was cooled to 10 ° C under dry nitrogen, and 2.94 g (0.01 mol) of biphenyltetracarboxylic dianhydride and 13.32 g of hexafluoroisopropylidene-2,2-bis (phthalic anhydride) were added. .03 mol).
Five hours after the introduction, the temperature was returned to room temperature, and the mixture was stirred at room temperature for 2 hours to obtain a solution of polyamic acid as a polyimide precursor. After adding 50 g of pyridine to the polyamic acid solution, 0.05 mol of acetic anhydride was added dropwise, and the temperature of the system was reduced to 70%.
The imidation reaction was carried out for 7 hours while maintaining the temperature. This solution was added dropwise to 20 times the volume of water, and the precipitate was collected.
Vacuum drying was performed for 2 hours to obtain a solid material of polyimide which is a heat-resistant polymer material.

(2) Measurement of Glass Transition Temperature and Dielectric Constant of Heat-Resistant Polymer Material 5.0 g of the polyimide synthesized as above was added to NMP1
After dissolving in 5.0 g and applying it on a release-treated glass substrate, it was kept in an oven at 120 ° C. for 30 minutes, and then 230 ° C.
After holding the film for 90 minutes, peeling off the film from the substrate,
It was further heated at 400 ° C. for 90 minutes to obtain a polyimide film. The glass transition temperature of this polyimide was 335 ° C. as measured by a differential scanning calorimeter. Further, 5.0 g of the polyimide obtained above was added to NMP20.
After dissolving in 0 g, a 200 nm-thick tantalum film was spin-coated on a silicon wafer. 2 at 100 ° C
After pre-baking for 1 minute,
After heating at 50 ° C for 30 minutes, 250 ° C at a rate of 5 ° C / minute
The temperature was raised at 250 ° C. for 60 minutes, and then raised to 350 ° C. at a rate of 10 ° C./min.
C. for 5 minutes to obtain a 0.8 .mu.m thick polyimide film. An aluminum electrode having an area of 0.1 cm ² was formed on this film by vapor deposition, and the capacitance between the electrode and tantalum on the substrate was measured by an LCR meter. The dielectric constant of the polyimide calculated from the film thickness, the electrode area, and the capacitance was 2.9.

(3) Measurement of molecular weight of polymer whose molecular weight is reduced by light irradiation and temperature of volatilization after molecular weight reduction The molecular weight of polymethyl methacrylate to be used for preparing a composition for insulating material is measured by GPC. As a result, the number average molecular weight in terms of polystyrene was 2.5 × 10 ⁴ . 10 mg of this polymethyl methacrylate was placed in a sample pan for thermogravimetric analysis (TG / DTA),
Ultraviolet light was irradiated for 5 minutes by an ultraviolet exposure apparatus using a low-pressure mercury lamp of W. Thereafter, the TG was heated at a rate of 5 ° C./min.
The temperature at which volatilization after molecular weight reduction was measured by / DTA was 110 ° C.

(4) Preparation of Composition for Insulating Material and Production of Insulating Material 10.0 g of the polyimide obtained above was added to NMP50.
After dissolving in 0 g, the same polymethyl methacrylate (5.0 g) as above was added and stirred to obtain an insulating material composition. The composition for an insulating material was spin-coated on a silicon wafer on which a 200 nm-thick tantalum film was formed in an environment in which ultraviolet light having a wavelength of 400 nm or less was shielded from light. After pre-baking at 100 ° C. for 2 minutes, 150 ° C. in an oven under a nitrogen atmosphere.
After heating at 30 ° C. for 30 minutes, the temperature was raised to 300 ° C. at a rate of 5 ° C./minute, and the temperature was maintained at 300 ° C. for 30 minutes.
The temperature was lowered at a rate of 0 ° C. to room temperature. The wafer was taken out of the oven and irradiated with ultraviolet rays for 5 minutes by an ultraviolet exposure apparatus using a 200 W low-pressure mercury lamp. Then, using an oven with a ventilator, 200 ° C. in an air atmosphere
For 4 hours. Thus, a 0.8 μm-thick insulating film was obtained. An area of 0.1 on the insulation film
An aluminum electrode of cm ² was formed by vapor deposition, and the capacitance between the electrode and tantalum on the substrate was measured by an LCR meter. The dielectric constant of the insulating material calculated from the film thickness, the electrode area, and the capacitance was 2.4. As a result of calculating from the dielectric constant using the equation of the logarithmic mixing method, the porosity of the insulating film was about 18%. Also, as a result of observation by TEM,
The average diameter of the voids in the insulating material film was 5 nm.

Example 2 (1) Synthesis of Polyimide Precursor In the synthesis of the polyimide in Example 1, 2,2′-bis (4- (4,4′-aminophenoxy) used in the synthesis of the precursor was used. 5.18 g of phenyl) hexafluoropropane
(0.01 mol) and 9.60 g of 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl
(0.03 mol) to 4.01 g (0.04 mol) of 4,4′-diaminodiphenyl ether and 2.94 g (0.01 mol) of biphenyltetracarboxylic dianhydride
Example 1 except that 13.32 g (0.03 mol) of hexafluoroisopropylidene-2,2-bis (phthalic anhydride) was replaced with 8.72 (0.04 mol) of pyromellitic dianhydride. In the same manner as in the above, a solution of a polyamic acid as a polyimide precursor was obtained. This solution was dropped into a 20-fold amount of water to collect a precipitate, followed by vacuum drying at 25 ° C. for 72 hours to obtain a solid of polyamic acid, which is a precursor of polyimide as a heat-resistant polymer material.

(2) Measurement of Glass Transition Temperature and Dielectric Constant of Heat-Resistant Polymer Material 5.0 g of the polyamic acid synthesized as described above was added to NMP2
After dissolving it in 0.0 g and applying it on a release-treated glass substrate, it was kept in an oven at 120 ° C. for 30 minutes, and then 250 ° C.
After holding the film for 90 minutes, peeling off the film from the substrate,
It was further heated at 450 ° C. for 90 minutes to obtain a polyimide film. The glass transition temperature of this polyimide was 419 ° C. as measured by a differential scanning calorimeter. Further, 5.0 g of the polyamic acid synthesized above was added to NM
After dissolving in 20.0 g of P, a 200 nm thick tantalum film was spin-coated on a silicon wafer. 10
After pre-baking at 0 ° C. for 2 minutes, heating at 150 ° C. for 30 minutes in a nitrogen atmosphere oven, increasing the temperature to 250 ° C. at a rate of 5 ° C./min, and holding at 250 ° C. for 60 minutes,
Further, the temperature was raised to 350 ° C. at a rate of 10 ° C./min and maintained at 350 ° C. for 5 minutes to obtain a 0.8 μm-thick polyimide film. Thereafter, the dielectric constant of this polyimide was measured in the same manner as in Example 1, and it was 3.1.

(3) Preparation of Composition for Insulating Material and Production of Insulating Material 10.0 g of the polyamic acid synthesized as described above was added to NMP5
After dissolving in 0.0 g, the same polymethyl methacrylate as used in Example 1 (9.0 g) was added and stirred to obtain a composition for an insulating material. The composition for an insulating material was spin-coated on a silicon wafer on which a 200 nm-thick tantalum film was formed in an environment in which ultraviolet light having a wavelength of 400 nm or less was shielded from light. After pre-baking at 100 ° C. for 2 minutes, heating in a nitrogen atmosphere oven at 150 ° C. for 30 minutes, then increasing the temperature to 250 ° C. at a rate of 5 ° C./minute, holding at 250 ° C. for 60 minutes, and further every minute The temperature was raised to 350 ° C. at a temperature increasing rate of 10 ° C., and the temperature was maintained at 350 ° C. for 5 minutes.
The temperature was lowered to room temperature at a rate of ° C. The wafer was taken out of the oven and irradiated with ultraviolet rays for 5 minutes by an ultraviolet exposure apparatus using a 200 W low-pressure mercury lamp. Then 30
The wafer was immersed in tetrahydrofuran whose temperature was controlled at ° C for 24 hours, and then dried at 100 ° C for 1 hour. Thus, a 0.8 μm-thick insulating film was obtained. Thereafter, the dielectric constant of this insulating material was measured in the same manner as in Example 1, and it was 2.4. As a result of calculating from the dielectric constant using the logarithmic mixing method, the porosity of the insulating film was about 23%. As a result of observation with a TEM, the diameter of the voids in the insulating film was 5 nm on average.

Example 3 (1) Synthesis of polybenzoxazole 25 g of 4,4'-hexafluoroisopropylidenediphenyl-1,1'-dicarboxylic acid, 45 m of thionyl chloride
l and 0.5 ml of dry dimethylformamide were placed in a reaction vessel and reacted at 60 ° C. for 2 hours. After completion of the reaction, excess thionyl chloride was distilled off by heating and reduced pressure. The precipitate was recrystallized using hexane to obtain 4,4'-hexafluoroisopropylidenediphenyl-1,1'dicarboxylic acid chloride. In a separable flask equipped with a stirrer, a nitrogen introducing tube, and a dropping funnel, 7.32 g (0.02 mol) of 2,2′-bis (3-amino-4-hydroxyphenyl) hexafluoropropane was added to 100 g of dried dimethylacetamide. 3.96 g of pyridine
(0.05 mol), and then -15 under dry nitrogen introduction.
8.55 g of 4,4'-hexafluoroisopropylidenediphenyl-1,1'-dicarboxylic acid chloride synthesized above was added to 50 g of dimethylacetamide at 50 ° C (0.5 g).
02mol) was added dropwise over 30 minutes.
After completion of the dropwise addition, the mixture was returned to room temperature and stirred at room temperature for 5 hours. Thereafter, the reaction solution was dropped into 1000 ml of water, and the precipitate was collected and vacuum-dried at 40 ° C. for 48 hours to obtain a solid substance of polyhydroxyamide, a polybenzoxazole precursor. This polyhydroxyamide is converted to NMP200
After adding 50 g of pyridine to the solution dissolved in g, 0.03 mol of acetic anhydride was added dropwise, and the oxazolation reaction was carried out for 7 hours while maintaining the temperature of the system at 70 ° C. Add this solution to 20
The precipitate was collected by dropping it in double the volume of water, and vacuum-dried at 60 ° C. for 72 hours to obtain a solid substance of polybenzoxazole, which is a heat-resistant polymer material.

(2) Measurement of glass transition temperature and dielectric constant of heat-resistant polymer material 5.0 g of polyhydroxyamide synthesized as described above was
After dissolving in 20.0 g of NMP and applying it on a glass substrate subjected to mold release treatment, it was kept in an oven at 120 ° C. for 30 minutes,
A film was formed by holding the film at 240 ° C. for 90 minutes, and after peeling the film from the substrate, the film was further heated at 400 ° C. for 90 minutes to obtain a polybenzoxazole film. The glass transition temperature of this polybenzoxazole was 362 ° C. as measured by a differential scanning calorimeter. Further, 5.0 g of the polyhydroxyamide synthesized above was added to 20.0 g of NMP.
And then spin-coated on a 200 nm thick tantalum film-formed silicon wafer. After pre-baking at 100 ° C. for 2 minutes, 150 ° C. in an oven under a nitrogen atmosphere.
After heating at 30 ° C for 30 minutes, the temperature was raised to 300 ° C at a rate of 5 ° C / minute, and after holding at 300 ° C for 30 minutes, the thickness was 0.8 µm.
m of polybenzoxazole was obtained. Thereafter, the dielectric constant of this polybenzoxazole was measured in the same manner as in Example 1, and was 2.6.

(3) Preparation of Composition for Insulating Material and Production of Insulating Material 5.0 g of polybenzoxazole synthesized as described above
Was dissolved in 20.0 g of NMP, and 4.0 g of the same polymethyl methacrylate as used in Example 1 was added thereto and stirred to obtain a composition for an insulating material. The composition for an insulating material was spin-coated on a silicon wafer on which a 200 nm-thick tantalum film was formed in an environment in which ultraviolet light having a wavelength of 400 nm or less was shielded from light. After pre-baking at 100 ° C. for 2 minutes, heating at 150 ° C. for 30 minutes in an oven in a nitrogen atmosphere, then increasing the temperature to 300 ° C. at a rate of 5 ° C./min.
After holding at 00 ° C. for 30 minutes, the temperature was lowered at a rate of 10 ° C. per minute and returned to room temperature. The wafer was taken out of the oven and irradiated with ultraviolet rays for 5 minutes by an ultraviolet exposure apparatus using a 200 W low-pressure mercury lamp. Then, it heated at 200 degreeC for 4 hours in air atmosphere using the oven with a ventilation device. Thus, a 0.8 μm-thick insulating film was obtained. Thereafter, the dielectric constant of this insulating material was measured in the same manner as in Example 1 and found to be 2.1. As a result of calculating from the dielectric constant using the equation of the logarithmic mixing method, the porosity of the insulating film is about 22%.
Met. As a result of observation with a TEM, the diameter of the voids in the insulating film was 5 nm on average.

Example 4 (1) Synthesis of polyhydroxyamide 2,2'-bis (trifluoromethyl) biphenyl-
4,4'-dicarboxylic acid 22g, thionyl chloride 45ml
And 0.5 ml of dry dimethylformamide was put into a reaction vessel and reacted at 60 ° C. for 2 hours. After completion of the reaction, excess thionyl chloride was distilled off by heating and reduced pressure. The precipitate was recrystallized using hexane to obtain 2,2′-bis (trifluoromethyl) biphenyl-4,4′-dicarboxylic acid chloride. In a separable flask equipped with a stirrer, a nitrogen introducing tube, and a dropping funnel, 7.32 g (0.02 mol) of 2,2′-bis (3-amino-4-hydroxyphenyl) hexafluoropropane was added to 100 g of dried dimethylacetamide. 3.96 g of pyridine
(0.05 mol), and then -15 under dry nitrogen introduction.
At 50 ° C., 50 g of dimethylacetamide was added to 2,2′-bis (trifluoromethyl) biphenyl-
4,4'-dicarboxylic acid chloride 8.30 (0.02m
ol) was added dropwise over 30 minutes. After completion of the dropwise addition, the mixture was returned to room temperature and stirred at room temperature for 5 hours. afterwards,
The reaction solution was dropped into 1000 ml of water, and the precipitate was collected.
By vacuum drying at 0 ° C. for 48 hours, a solid substance of polyhydroxyamide, which is a precursor of polybenzoxazole, which is a heat-resistant polymer material, was obtained.

(2) Measurement of Glass Transition Temperature and Dielectric Constant of Heat-Resistant Polymer Material 5.0 g of polyhydroxyamide synthesized as described above was
After dissolving in 20.0 g of NMP and applying it on a glass substrate subjected to mold release treatment, it was kept in an oven at 120 ° C. for 30 minutes,
The film was formed by holding the film at 240 ° C. for 90 minutes, and after peeling off the film from the substrate, the film was further heated at 400 ° C. for 90 minutes to obtain a polybenzoxazole film as a heat-resistant polymer material. The glass transition temperature of this polybenzoxazole was measured by a differential scanning calorimeter, and was 410 ° C. Furthermore, after dissolving 5.0 g of the polyhydroxyamide synthesized as described above in 20.0 g of NMP,
Spin coating was performed on a silicon wafer on which a 0 nm tantalum film was formed. After prebaking at 100 ° C. for 2 minutes, heating at 150 ° C. for 30 minutes in an oven in a nitrogen atmosphere, raising the temperature to 350 ° C. at a rate of 5 ° C./minute, holding at 350 ° C. for 5 minutes, and then forming a layer having a thickness of 0.1 mm. An 8 μm polybenzoxazole coating was obtained. Thereafter, the dielectric constant of this polybenzoxazole was measured in the same manner as in Example 1, and it was 2.6.

(3) Preparation of Composition for Insulating Material and Production of Insulating Material After dissolving 10.0 g of the polyhydroxyamide synthesized above in 50.0 g of NMP, the same polymethyl methacrylate 9 as used in Example 1 was dissolved. 0.0g was added and stirred to obtain a composition for insulating material. In an environment in which ultraviolet light having a wavelength of 400 nm or less is shielded, this insulating material
Spin coating was performed on a silicon wafer on which tantalum of 00 nm was formed. After pre-baking at 100 ° C for 2 minutes,
After heating at 150 ° C. for 30 minutes in a nitrogen atmosphere oven, the temperature was raised to 350 ° C. at a rate of 5 ° C./min.
After holding for 5 minutes at, the temperature was lowered at a rate of 10 ° C. per minute and returned to room temperature. Remove the wafer from the oven,
Ultraviolet light was irradiated for 5 minutes by an ultraviolet exposure apparatus using a 0 W low-pressure mercury lamp. Then, it heated at 200 degreeC for 4 hours in air atmosphere using the oven with a ventilation device. Thus, a 0.8 μm-thick insulating film was obtained. Thereafter, the dielectric constant of this insulating material was measured in the same manner as in Example 1, and it was 2.1. As a result of calculation from the dielectric constant using the logarithmic mixing method, the porosity of the insulating film was about 22%. As a result of observation with a TEM, the diameter of the voids in the insulating film was 5 nm on average.

Example 5 (1) Measurement of Melting Point and Dielectric Constant of Heat-Resistant Material A 10% xylene solution of perhydroxypolysilazane was
After being applied on a release-treated glass substrate, it was dried in an oven at 80 ° C. for 30 minutes. Subsequently, the substrate was treated in a temperature / humidity bath at a temperature of 95 ° C. and a humidity of 80% for 3 hours, and then treated at 350 ° C. for 1 hour in an oven in an air atmosphere to obtain a heat-resistant material containing silica as a main component. When the melting point of this heat-resistant material was measured with a differential scanning calorimeter, the melting point was not confirmed in the range of 500 ° C. or less, and was found to be 500 ° C. or more. Further, a 10% xylene solution of perhydroxypolysilazane was spin-coated on a 200-nm-thick silicon wafer on which tantalum was formed. Then, it was dried in an oven at 80 ° C. for 30 minutes. Subsequently, after treating for 3 hours in a temperature / humidity bath at a temperature of 95 ° C. and a humidity of 80%, a treatment was carried out at 350 ° C. for 1 hour in an oven in an air atmosphere, and a thickness of 0.8 μm
m was obtained. Thereafter, the dielectric constant of this insulating material was measured in the same manner as in Example 1 and found to be 6.0.

(2) Measurement of the molecular weight of the polymer whose molecular weight is reduced by light irradiation and the temperature at which it volatilizes after the molecular weight reduction. The molecular weight of poly (α-methylstyrene) to be used for preparing the insulating material composition is as follows. As measured by GPC, the number average molecular weight in terms of polystyrene was 5.0 × 10 ⁴ . 10 mg of this polymethyl methacrylate was placed in a thermogravimetric analysis (TG / DTA) sample pan, and 200 W
UV light was applied for 5 minutes by an ultraviolet light exposure apparatus using a low-pressure mercury lamp. Thereafter, the TG / D was heated at a rate of 5 ° C./min.
It was 165 degreeC when the volatilization temperature after molecular weight reduction was measured by TA.

(3) Preparation of composition for insulating material and production of insulating material 10% xylene solution of perhydroxypolysilazane 50
Then, 7.0 g of the above-mentioned poly (α-methylstyrene) was added to the resulting mixture and stirred to obtain a composition for an insulating material. In an environment in which ultraviolet light having a wavelength of 400 nm or less is shielded, the composition for an insulating material is
Spin coating was performed on a silicon wafer having a thickness of 200 nm formed with tantalum. After pre-baking at 80 ° C for 2 minutes, it is treated in a temperature / humidity bath at a temperature of 95 ° C and a humidity of 80% for 3 hours, subsequently heated in an air atmosphere oven at 150 ° C for 30 minutes, and then heated at a rate of 5 ° C per minute. To raise the temperature to 250 ° C,
After holding at 250 ° C. for 180 minutes, the temperature was lowered at a rate of 10 ° C. per minute to room temperature. The wafer was taken out of the oven and irradiated with ultraviolet rays for 5 minutes by an ultraviolet exposure apparatus using a 200 W low-pressure mercury lamp. Then, it heated at 200 degreeC for 4 hours in air atmosphere using the oven with a ventilation device. Thus, a 0.8 μm-thick insulating film was obtained. Thereafter, the dielectric constant of this insulating material was measured in the same manner as in Example 1, and it was 2.3. As a result of calculation from the dielectric constant using the logarithmic mixing method, the porosity of the insulating material film was about 54%. As a result of observation with a TEM, the diameter of the voids in the insulating film was 5 nm on average.

Comparative Example 1 In the preparation of the insulating material composition of Example 2, the polymethyl methacrylate 9.0 used was used.
A coating was obtained in the same manner as in Example 2 except that g was not added. The dielectric constant of the obtained heat-resistant resin was 2.6. In addition, no porosity of the film was observed by TEM observation.

Comparative Example 2 In the preparation of the insulating material composition of Example 4, the polymethyl methacrylate 9.0 used was used.
The composition was adjusted in the same manner as in Example 4 except that 9.0 g of polypropylene glycol was added instead of g, and a film was obtained. The dielectric constant of the obtained heat-resistant resin is 2.
It was 6. In addition, no porosity of the film was observed by TEM observation.

In Examples 1 to 5, the dielectric constant was 2.1.
A very low heat-resistant resin of ~ 2.4 was obtained.

In Comparative Example 1, the dielectric constant was not able to be reduced because the component which did not contain a polymer whose molecular weight was reduced by light irradiation and did not form voids in the insulating film.

In Comparative Example 2, the dielectric constant could not be reduced because the added polypropylene glycol was not a polymer whose molecular weight was reduced by light irradiation and did not form voids in the insulating film.

[0045]

The resin composition for insulating material of the present invention and the insulating material using the same are excellent in electrical properties and heat resistance, and are used in various fields where these properties are required, for example, for semiconductors. It is an insulating material useful as an interlayer insulating film, an interlayer insulating film of a multilayer circuit, and the like.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // C08J 9/26 CFG C08J 9/26 CFG 5G305 102 102 C09D 5/25 C09D 5/25 179/04 179 / 04 BF term (reference) 4F070 AA18 AA32 AA55 AB11 HA02 HB14 4F074 AA32 AA48 AA74 CB03 CB04 CB17 CB28 CC30X CC50 DA03 DA47 4J002 BC092 BG062 CM041 GQ01 4J038 CC081 CC082 DJ001 DJ1 002 DJ01 002 DL002 DL031 DL032 KA03 KA06 NA14 NA21 PA17 PB09 5F058 AA10 AC02 AF04 AG01 AH01 AH02 5G305 AA06 AA07 AA11 AB10 AB24 BA09 BA14 CA20 CA21 CA26 CA32 CD12 CD20

Claims (4)

[Claims] 1. An insulating composition comprising a polymer (A) whose molecular weight is reduced by light irradiation and a heat-resistant material or its precursor (B) as essential components. 2. The heat-resistant material or a precursor (B) thereof,
2. A heat-resistant polymer or a heat-resistant polymer precursor.
The composition for an insulating material according to the above. 3. A heat-resistant polymer or its precursor (B)
3. The composition for an insulating material according to claim 2, wherein is a polybenzoxazole or a polybenzoxazole precursor. 4. A step of using the composition for an insulating material according to claim 1 to lower the molecular weight of the component (A) by light irradiation, and then volatilizing or extracting the component. An insulating material manufactured by a method having the above.