JP2012009796A - Semiconductor insulating film composition containing polyorganosilsesquioxane having methacryloxy group or acryloxy group - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor insulating film composition containing a polyorganosilsesquioxane having a methacryloxy group or an acryloxy group and a method for producing a thin film using the semiconductor insulating film composition, and an insulating film produced by the method and exhibiting resistance against an organic solvent.SOLUTION: A semiconductor insulating film composition is prepared by adding a vinyl monomer and a polymerization initiator to a polyorganosilsesquioxane having a methacryloxy group or an acryloxy group. After the semiconductor insulating film composition is coated by a spin coating method or the like, radical polymerization of a vinyl group is performed with heating or an ultraviolet irradiation. Subsequently, the semiconductor insulating film composition is compositely cured by condensation polymerization of an alkoxy group to produce a silicone insulating film (polysilsesquioxane film).

Description

The present invention relates to a composition for a semiconductor insulating film mainly composed of a polyorganosilsesquioxane having a methacryloxy group or an acryloxy group, and a method for producing a polyorganosilsesquioxane-based insulating film resistant to an organic solvent. It is.

Polyorganosilsesquioxane (hereinafter referred to as PSQ) is a general term for silicone resins in which the ratio of the number of oxygen atoms to the number of silicon atoms is 1.5. Since such PSQ compounds have both organic and inorganic characteristics, they are excellent in solubility in organic solvents and film-forming properties, and have heat resistance and electrical insulation properties. Therefore, they are used as insulating materials for optical and electronic device materials. ing.

With the recent increase in demand for electronic paper and flexible displays, there is a demand for an insulating film that can be produced on a plastic substrate by a wet process and that can be cured under relatively mild reaction conditions. PSQ is excellent in flexibility compared with inorganic solids such as silica, and is expected to be a promising insulating material because it can be dissolved in an organic solvent and a large-area coating film can be formed at once by a spin coating method or the like. Yes.

Various PSQs have been studied so far (for example, Patent Documents 1 and 2). In particular, polyphenylsilsesquioxane (hereinafter referred to as PPSQ) having a phenyl group in a side chain is an organic semiconductor. For example, it is considered that high transistor characteristics can be exhibited because of excellent adhesiveness with a compound such as pentacene. However, PPSQ cannot be applied on a plastic substrate because it requires a reaction temperature of 200 ° C. or higher in curing by condensation polymerization of an alkoxy group present at the terminal. On the other hand, in polymethylsilsesquioxane (hereinafter referred to as PMSQ) having a methyl group in the side chain, the curing temperature can be kept low, but since it does not have an aromatic ring in the side chain, the organic semiconductor It is thought that the adhesiveness with the is not good. Therefore, there is a demand for PSQ having a low curing temperature while containing an aryl group as a main component.

In the case of a compound having a plurality of methacryloxy groups or acryloxy groups in the molecule, the radical polymerization is generated by the irradiation of ultraviolet rays or heating in the presence of a polymerization initiator, whereby the vinyl group undergoes addition polymerization and becomes insoluble as a result of chemical crosslinking. . Therefore, PPSQ having a plurality of methacryloxy groups or acryloxy groups in one molecule can be cured at a low temperature and is considered to be excellent in adhesion to an organic semiconductor. However, the radical polymerization of the vinyl group alone is insufficient for curing, and insolubilization in an organic solvent cannot be achieved.

JP-A-2001-354771 JP 2009-59651 A JP 4-76059 JP-A-5-1124

An object of the present invention is to provide a PSQ having a methacryloxy group or an acryloxy group that can be cured at a low temperature, a method for producing a PSQ thin film, a radical polymerization of a vinyl group, and a condensation polymerization of an alkoxy group in view of the problems of the background art. It is to provide an insulating film that is insoluble in an organic solvent by being cured in a complex manner.

In order to achieve the above object, the present inventors have conducted intensive studies, and as a result, have been achieved by the following means.
That is, the composition for semiconductor insulation films which mixes a polymerization initiator with PSQ represented by General formula (1), and mix | blends the organic solvent. (Claim 1)
(However, l, m, and n are positive integers, R ₁ is an aryl group, R ₂ is an alkyl group, and R ₃ is a methacryloxy group or an acryloxy group represented by the general formula (2).
(Wherein R ₅ is a hydrogen atom or a methyl group, R ₆ is an unsubstituted or substituted alkyl group having 1 to 18 carbon atoms), and R ₄ is selected from hydrogen, a methyl group, and an ethyl group Shall be. )

The composition of claim 1 comprising a vinyl monomer. (Claim 2)

A film forming method comprising applying the composition according to claim 2 and performing a composite curing treatment by radical polymerization of vinyl groups and condensation polymerization of terminal alkoxy groups. (Claim 3)

A PSQ insulating film, which is insoluble in an organic solvent produced by the method of claim 3. (Claim 4)

A feature of the present invention is that a PSQ having a methacryloxy group or an acryloxy group, a vinyl monomer and a polymerization initiator are dissolved in an organic solvent to form a composition for a semiconductor insulating film. It is to produce a film that is insoluble in an organic solvent under relatively mild reaction conditions by performing chemical cross-linking in combination by polymerization and condensation polymerization of alkoxy groups.

According to the present invention, a PSQ film that is insoluble in an organic solvent under relatively mild reaction conditions can be produced by performing chemical cross-linking in combination by radical polymerization of vinyl groups and condensation polymerization of alkoxy groups. On the other hand, an insulating film exhibiting resistance to an organic solvent cannot be produced only by radical polymerization of vinyl groups or condensation polymerization of alkoxy groups. Moreover, the functionalization according to the kind of functional group is simultaneously possible by adding a vinyl monomer. In particular, the water repellency of the film can be adjusted by introducing a hydrophobic substituent such as a fluoroalkyl group.

According to the present invention, an insulating film that is insoluble in an organic solvent can be produced under relatively mild reaction conditions, so that it is possible to prevent deformation and distortion of a plastic substrate and the like, which is an extremely useful technique.

The voltage-resistance diagram of the PSQ film produced in Example 1 after ultrasonic treatment with acetone is shown (Example 5). The voltage-resistance diagram of the PSQ film produced in Example 3 after ultrasonic treatment with acetone is shown (Example 5). The voltage-resistance diagram of the PSQ film produced in Comparative Example 1 after ultrasonic treatment with acetone is shown (Example 5). The atomic force microscope measurement result (shape image) of the PSQ film produced in Example 3 is shown (Example 7). The structure of the organic transistor produced in Example 8 is shown. The output characteristic of the organic transistor produced in Example 8 is shown.

The present invention
Step (A) A method for preparing and applying a composition for a semiconductor insulating film containing PSQ, a vinyl monomer, and a polymerization initiator,
Step (B) a method of curing the film by radical polymerization of vinyl group,
Step (C) a method of curing the film by condensation polymerization of alkoxy groups,
Will be described in detail below. The present invention is not limited to these.
<Process A>

PSQ in process A
Regarding the PSQ represented by the general formula (1), the molar ratio of an organic group containing a methacryloxy group or an acryloxy group and other organic groups (aryl group and alkyl group) includes from 99: 1 to 1:99. 5: 95-50: 50 is preferable. When the organic group containing methacryloxy group or acryloxy group is less than 5 mol%, curing by radical polymerization of vinyl group is not sufficient, and when it is 50 mol% or more, PSQ mainly takes a random structure instead of a ladder structure. This is because the solubility in the solvent is lowered, and the production of the thin film is hindered.

About PSQ represented by General formula (1), although the molar ratio of an aryl group and an alkyl group contains from 99: 1 to 1:99, 90: 10-60: 40 is preferable. This is because an aryl group is used as a main component in order to improve the adhesion to an organic semiconductor, but if the alkyl group is not contained in an amount of 10% or more, the curing temperature becomes high and curing by condensation polymerization of the alkoxy group becomes insufficient.

The weight average molecular weight of PSQ is 1,000 to 100,000. When the molecular weight is 1,000 or less, the number of methacryloxy groups or acryloxy groups contained in one PSQ molecule is small, so that curing by radical polymerization of vinyl groups is not sufficient, and when the molecular weight is 100,000 or more, PSQ This is because the solubility in the organic solvent decreases.

R ₁ in the general formula (1) is selected from aryl groups. Examples of the aryl group include a phenyl group, a naphthyl group, or a phenyl group partially substituted with a halogen atom or an alkyl group.

R ₂ in the general formula (1) is selected from alkyl groups. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an octyl group, an octadecyl group, or an alkyl group partially substituted with a halogen atom, a cyano group, or the like.

R ₅ in the general formula (2) is a hydrogen atom or a methyl group. R ₆ is an unsubstituted or substituted hydrocarbon group having 1 to 18 carbon atoms. Examples of the unsubstituted hydrocarbon group for R ₆ include alkylene groups such as methylene, trimethylene, and tetramethylene. Examples of the substituted hydrocarbon group include an alkyl group, an alkenyl group, an aryl group, a cycloalkyl group, or a group obtained by substituting a part of hydrogen atoms bonded to carbon atoms of these groups with a halogen atom, a cyano group, or the like. It is done.

PSQ is known per se and can be obtained, for example, by the production methods described in Patent Documents 3 and 4.

The vinyl monomer to be mixed with the vinyl monomer PSQ in the step A can be any monofunctional, bifunctional or polyfunctional vinyl monomer. However, when applying by spin coating, a vinyl monomer having a relatively high viscosity is better. In addition, when a vinyl monomer having low compatibility with PSQ is used, phase separation may be caused in the membrane, so it is necessary to select it in consideration of compatibility with PSQ. Examples of the monofunctional methacrylate (acrylate) include methyl methacrylate (hereinafter referred to as MMA), butyl methacrylate (hereinafter referred to as BMA), stearyl methacrylate, methoxypolyethylene glycol acrylate, phenoxypolyethylene glycol acrylate, and the like. Examples of the bifunctional methacrylate (acrylate) include polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, tricyclodecane dimethanol diacrylate, 1,10-decanediol diacrylate, neopentyl glycol dimethacrylate, and the like. Examples of the polyfunctional methacrylate (acrylate) include trimethylolpropane triacrylate (hereinafter referred to as A-TMPT), trimethylolpropane trimethacrylate (hereinafter referred to as TMPT), ditrimethylolpropane tetraacrylate, and pentaerythritol tetra. Examples thereof include acrylate and dipentaerythritol hexaacrylate. About A-TMPT, it represents in General formula (3).
Examples of other types of vinyl monomers include styrene, divinylbenzene, acrylamide, N, N′-ethylenebisacrylamide, N-isopropylacrylamide (hereinafter referred to as NIPAM), and the like.

The vinyl monomer mixed with PSQ is not necessarily one kind. Two or more kinds of vinyl monomers can be mixed and used.

Polymerization initiator in step A As the initiator used for radical polymerization, various conventionally known initiators can be used, for example, acetophenone, propiophenone, benzophenone, 1-hydroxycyclohexyl. Examples include phenyl ketone, santol, fluorene, anthraquinone, benzaldehyde, benzoyl peroxide (hereinafter referred to as BPO), azobisisobutyronitrile (hereinafter referred to as AIBN), and the like. These polymerization initiators can be used alone or in combination of two or more. In the present invention, when the above polymerization initiator is used, it is possible to further enhance the photopolymerizability by using a so-called photosensitization accelerator such as a tertiary amine. As the tertiary amine, various aliphatic and aromatic tertiary amines can be used, and examples thereof include N-dimethanolamine, triethanolamine, N-methyldiethanolamine, triethylamine, and ethyl P-dimethylaminobenzoate.

Any solvent can be used as long as it dissolves the organic solvent PSQ, the vinyl monomer, and the polymerization initiator in Step A and does not inhibit the radical polymerization of the vinyl group. The boiling point is preferably 60 to 180 ° C. Examples of the solvent include dimethylformamide (hereinafter referred to as DMF), toluene, xylene, tetrahydrofuran (hereinafter referred to as THF), dimethyl sulfoxide (hereinafter referred to as DMSO), methyl ethyl ketone (hereinafter referred to as MEK), methyl isobutyl. Ketone (hereinafter referred to as MIBK), 1,4-dioxane, 1,2-dichloroethane, tert-butanol, propylene glycol 1-monomethyl ether 2-acetate (hereinafter referred to as PGMEA), propyl acetate, butyl acetate and the like It is done.

The concentration of PSQ used in step A The concentration of PSQ can be adjusted to any concentration as long as it dissolves in an organic solvent. In order to produce a film that is resistant to organic solvents and excellent in insulating properties, the PSQ concentration is preferably 20 to 50 wt% of the total weight including the solvent.

Concentration of vinyl monomer used in step A The concentration of vinyl monomer needs to be adjusted depending on its viscosity. For example, when a vinyl monomer having a viscosity of 100 mPa · s is used, the concentration of the vinyl monomer is preferably 10 to 20 wt% of the total weight including the solvent.

Concentration of polymerization initiator used in step A The concentration of the polymerization initiator is determined by the PSQ concentration and the component ratio of methacryloxy group or acryloxy group contained in PSQ. For example, when a molar ratio of an organic group containing a methacryloxy group or an acryloxy group to another organic group (aryl group and alkyl group) is 20:80 and the PSQ concentration is used at 30 wt% of the total weight including the solvent, polymerization is performed. The concentration of the initiator is preferably 0.5 to 5 wt% of the total weight including the solvent.

In step A, in addition to PSQ, a vinyl monomer, and a polymerization initiator, other additives can be mixed. For example, the effect of improving the smoothness of the film surface can be expected by mixing a polymer such as polystyrene or polymethyl methacrylate. Moreover, the effect of raising the dielectric constant of a film | membrane can be anticipated by mixing inorganic oxide particles, such as a titanium oxide particle and a zinc oxide particle.

Substrate used in step A Any substrate can be used as long as it is insoluble in the solvent used. Examples thereof include plastic substrates such as polyethylene terephthalate (hereinafter referred to as PET) and polyethylene naphthalate (hereinafter referred to as PEN), metals, mica, glass, silicon wafers, and the like. However, when an inorganic substrate is used, in order to improve the adhesiveness with PSQ, an operation may be necessary in which surface treatment is performed with a silylating agent to make the substrate hydrophobic.

Application method used in step A Examples of the application method on the substrate described above include spray coating, brush coating, dip coating, flow coating, spin coating, and the like.
<Process B>

Thermal polymerization reaction temperature and reaction time in step B The thermal polymerization reaction temperature and reaction time are determined according to the type and concentration of the polymerization initiator used. The reaction temperature may be adjusted to the radical generation temperature of the polymerization initiator, but it is preferable to perform the reaction at a temperature 10 to 20 ° C. higher than the radical generation temperature in the solution reaction in consideration of the heat permeability of the substrate. For example, when BPO is used as the polymerization initiator and the polymerization initiator is used at 2 wt% of the total weight including the solvent, the reaction temperature is preferably 60 to 90 ° C. and the reaction time is preferably 6 to 18 hours.

Photopolymerization reaction time in step B The photopolymerization reaction time is determined according to the type and concentration of the polymerization initiator used and the illuminance of the irradiated light. For example, when 1-hydroxycyclohexyl phenyl ketone is used as the polymerization initiator at 2 wt% of the total weight including the solvent, the illuminance is 170 mW / cm ² , and the ultraviolet light is irradiated, the reaction time is 3 ~ 5 minutes is preferred. However, since it may be heated suddenly by light irradiation, photopolymerization is performed on the cooling table so that the reaction temperature does not rise too much.

Ultraviolet source for photopolymerization in step B Examples of the ultraviolet source used in the photopolymerization include an ultraviolet fluorescent lamp, a mercury lamp, a xenon lamp, a halogen lamp, and a carbon arc lamp.
<Process C>

Reaction temperature and reaction time of the condensation polymerization of alkoxy groups in Step C The reaction temperature and reaction time of the condensation polymerization of alkoxy groups are determined according to the type and concentration of PSQ.
For example, when the molar ratio of the organic group containing methacryloxy group or acryloxy group, aryl group and alkyl group is 20:60:20 and the PSQ concentration is 30 wt% of the total weight including the solvent, the reaction temperature is 120 to 140 degreeC and reaction time have preferable 10 to 20 hours.

In Step C, the film surface can be chemically modified with a silylating agent before proceeding with the condensation polymerization of the alkoxy group. For example, in order to reduce the surface energy, the membrane surface may be modified with a hydrophobic molecule such as octadecyltrichlorosilane.

Thus, in the present invention, a semiconductor insulating film composition containing PSQ, a vinyl monomer, and a polymerization initiator is prepared in step A, applied to a substrate by a spin coat method, etc., and subsequently in steps B and C, The PSQ film obtained in A is cured in a complex manner by radical polymerization of vinyl groups and condensation polymerization of alkoxy groups to make it insoluble in organic solvents. In the manufacturing method of the present invention, the process is simple as described above, and an insulating film can be manufactured extremely easily with excellent reproducibility and efficiency.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto.

Synthesis of PSQ Synthesis Example 1
In a 500 mL four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser, 37.3 g (0.15 mol) of 3-methacryloxypropyltrimethoxysilane and 89.2 g (0.45 mol) of phenyltrimethoxysilane were added. ), 26.8 g (0.15 mol) of methyltriethoxysilane were added, and 1.13 × 10 ⁻³ mol of hydrochloric acid and 40.5 g (2.3 mol) of water were added in a water bath and reacted at room temperature for 40 minutes. Then, the temperature was raised to 65 ° C. and held for 1 hour. After cooling to 25 ° C., sodium hydroxide (1.73 × 10 ⁻³ mol) and ethanol (31.0 g, 0.68 mol) were added dropwise, and the mixture was stirred in a 25 ° C. water bath for 2.5 hours. After adding 225 g of MIBK, 1.2 g of 0.5N HCl water was added for neutralization to complete the reaction. Washing was performed 4 times with water using a separatory funnel. After washing, the MIBK layer was filtered, and MIBK was removed under reduced pressure to obtain a resin. The polystyrene equivalent weight average molecular weight (MW) of the obtained resin by gel permeation chromatography was 3,960, and the molecular weight distribution (MW / MN) was 1.81. The resin obtained here is hereinafter referred to as M-PMPSQ and is represented by the general formula (4).
Synthesis example 2
In a 500 mL four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser, 25.8 g (0.10 mol) of 3-methacryloxypropyltrimethoxysilane and 61.9 g (0.31 mol) of phenyltrimethoxysilane were added. ), 22.7 g (0.10 mol) of trifluorotrimethoxysilane were added, 0.78 × 10 ⁻⁴ mol of hydrochloric acid and 28.1 g (1.56 mol) of water were added in a water bath, and the reaction was carried out at room temperature for 40 minutes. Then, the temperature was raised to 65 ° C. and held for 1 hour. After cooling to 25 ° C., 1.09 × 10 ⁻⁴ mol of sodium hydroxide and 21.5 g (0.47 mol) of ethanol were added dropwise and stirred in a 25 ° C. water bath for 2.5 hours. After adding 150 g of MIBK, the reaction was terminated by adding 0.62 g of 0.5N HCl water to neutralize. Washing was performed 4 times with water using a separatory funnel. After washing, the MIBK layer was filtered, and MIBK was removed under reduced pressure to obtain a resin. The polystyrene equivalent weight average molecular weight (MW) of the obtained resin by gel permeation chromatography was 3,660, and the molecular weight distribution (MW / MN) was 1.89. The resin thus obtained is hereinafter referred to as M-PFPSQ and is represented by the general formula (5).

Production of thin film comprising M-PMPSQ, A-TMPT, BPO Using M-PMPSQ synthesized in Synthesis Example 1, A-TMPT as a vinyl monomer, and BPO as a polymerization initiator, a PSQ thin film was formed. Manufactured. Add 0.33 g of M-PMPSQ and 0.02 g of BPO to the sample tube, and add PGMEA containing 20% A-TMPT by volume to make the total amount to 1.00 g. Completely use M-PMPSQ and BPO in the solvent. Dissolved. Subsequently, the previous solution was cast on a glass substrate whose surface was coated with gold, and spin-coated (2.000 rpm, 30 s) (step A). In the chamber, the reaction temperature was heated to 80 ° C. for 12 hours (step B), and then the reaction temperature was heated to 120 ° C. for 12 hours (step C) to obtain a PSQ cured film.

Production of thin film comprising M-PMPSQ, A-TMPT, 1-hydroxycyclohexyl phenyl ketone M-PMPSQ synthesized in Synthesis Example 1, A-TMPT as vinyl monomer, and 1-hydroxycyclohexyl phenyl as polymerization initiator A thin film of PSQ was prepared using ketone. To the sample tube, 0.33 g of M-PMPSQ and 0.02 g of 1-hydroxycyclohexyl phenyl ketone were added, and PGMEA containing 20% by volume of A-TMPT was added to make a total amount of 1.00 g. -Hydroxycyclohexyl phenyl ketone was completely dissolved in the solvent. Subsequently, the above solution was cast on a glass substrate whose surface was coated with gold, and spin-coated (2,000 rpm, 30 s). Irradiance was set to 170 mW / cm ² and irradiation with ultraviolet rays was performed for 3 minutes, followed by heating in a chamber at a reaction temperature of 120 ° C. for 12 hours to obtain a cured PSQ film.

Production of thin film comprising M-PFPSQ, A-TMPT, BPO Using M-PFPSQ synthesized in Synthesis Example 2, A-TMPT as a vinyl monomer, and BPO as a polymerization initiator, a PSQ thin film was formed. Manufactured. To the sample tube, 0.33 g of M-PFPSQ synthesized in Synthesis Example 2 and 0.02 g of BPO were added, and PGMEA containing 20% by volume of A-TMPT was added to make the total amount to 1.00 g. And BPO were completely dissolved in the solvent. Subsequently, the above solution was cast on a glass substrate whose surface was coated with gold, and spin-coated (2,000 rpm, 30 s). In the chamber, the reaction temperature was set at 80 ° C. for 12 hours, and then the reaction temperature was set at 120 ° C. for 12 hours to obtain a PSQ cured film.

Comparative Example 1

Production of thin film comprising M-PMPSQ and BPO Production of PSQ thin film using M-PMPSQ synthesized in Synthesis Example 1 and BPO as a polymerization initiator in order to verify the necessity of vinyl monomer did. 0.33 g of M-PMPSQ and 0.02 g of BPO were added to the sample tube, and further PGMEA was added to make the total amount to 1.00 g, and M-PMPSQ and BPO were completely dissolved in the solvent. Subsequently, the above solution was cast on a glass substrate whose surface was coated with gold, and spin-coated (2,000 rpm, 30 s). In the chamber, the reaction temperature was set at 80 ° C. for 12 hours, and then the reaction temperature was set at 120 ° C. for 12 hours to obtain a cured PSQ film.

Comparative Example 2

Production of a thin film comprising M-PMPSQ (HMDS treatment), A-TMPT, BPO In order to verify the necessity of condensation polymerization of alkoxy groups, M-PMPSQ was changed to 1,1,1,3,3. All the alkoxy groups were capped with trimethylsilyl groups by treatment with 3-hexamethyldisilazane (hereinafter referred to as HMDS). Capping by the trimethylsilyl group was confirmed by ²⁹ Si NMR. Using this PSQ, A-TMPT as a vinyl monomer, and BPO as a polymerization initiator, a PSQ thin film was produced. Add 0.33 g of M-PMPSQ (HMDS treatment) and 0.02 g of BPO to the sample tube, and then add PGMEA containing 20% A-TMPT by volume to make the total amount 1.00 g. M-PMPSQ (HMDS treatment) ) And BPO were completely dissolved in the solvent. Subsequently, the above solution was cast on a glass substrate whose surface was coated with gold, and spin-coated (2,000 rpm, 30 s). In the chamber, the reaction temperature was set at 80 ° C. for 12 hours, and then the reaction temperature was set at 120 ° C. for 12 hours to obtain a PSQ cured film.

The degree of re-dissolution of the cured PSQ film in the organic solvent was compared. A PEN substrate cut to 3 × 3 cm was used as the substrate, 30 μL of the composition solution was cast, and spin-coated under the conditions of 2,000 rpm and 30 s. About the obtained PSQ coating substrate, the polymerization reaction was performed by the same operation as Examples 1-3 and Comparative Examples 1-2. Three PEN substrates were prepared for each, and evaluated with average values.

The substrate before coating with PSQ was previously weighed with a precision balance, and the cured PSQ-coated substrate was weighed with a precision balance. Subsequently, the sample was immersed in acetone, irradiated with ultrasonic waves for 1 minute, dried, and then weighed with a precision balance. The PSQ survival rate is calculated according to the following equation.
Weight of coated PSQ = (Weight of PSQ coated substrate after curing) − (Weight of substrate)
Remaining PSQ weight = (weight of PSQ coated substrate after acetone ultrasonic treatment)-(weight of substrate)
PSQ residual ratio = (weight of remaining PSQ) / (weight of coated PSQ) × 100
As a result, as shown in Table 1, the PSQ films produced in Examples 1 to 3 and Comparative Example 1 were insufficiently cured only by vinyl radical polymerization, but by combining with condensation polymerization of alkoxy groups. Organic solvent resistance was observed. In radical polymerization of vinyl groups, the reaction proceeded by generation of radicals by heating or ultraviolet irradiation, and in any case, resistance to organic solvents was realized by subsequent condensation polymerization of alkoxy groups. On the other hand, even after the same treatment was performed on the PSQ film produced in Comparative Example 2, a part of the PSQ was dissolved, and in order to achieve organic solvent resistance, condensation polymerization of alkoxy groups was performed on vinyl groups. It can be said that this is necessary in addition to the radical polymerization.

The PSQ films produced in Example 1, Example 3 and Comparative Example 1 were evaluated for electrical insulation after immersion in acetone. Before measurement, immerse the PSQ film in acetone and irradiate with ultrasonic waves for 1 minute, then ground the gold wire to the film surface and the underlying gold substrate, and change the voltage by the two-terminal method. A voltage-resistance diagram was created by measuring the current flowing in the direction perpendicular to the curve. As is clear from FIGS. 1, 2, and 3, the PSQ films manufactured in Example 1 and Example 3 showed high electrical resistance even when the applied voltage was increased, whereas in Comparative Example 1 In the manufactured PSQ film, the electric resistance was greatly reduced as compared with the films manufactured in Example 1 and Example 3. In the PSQ film produced in Comparative Example 1, no change in weight was observed even after the acetone treatment, but it is considered that a part of the film was dissolved at a micro level and as a result, the insulating property was destroyed. Therefore, it can be said that a vinyl monomer is necessary to realize organic solvent resistance.

The PSQ film produced in Example 1 and Example 3 was subjected to water contact angle measurement. The measurement was performed 5 times, and the average value was calculated. From Table 2, it can be considered that a PSQ film manufactured using M-PFPSQ has a smaller surface free energy and is advantageous for manufacturing a device of an organic transistor. In the following examples, the PSQ film produced in Example 3 was evaluated.

The PSQ film produced in Example 3 was measured with an atomic force microscope. As apparent from FIG. 4, a highly smooth film capable of stacking organic semiconductors such as pentacene has been manufactured. Moreover, even after sonicating with acetone for 1 minute, the shape was hardly changed, indicating high resistance to organic solvents.

The PSQ film was produced according to Example 3, and a transistor was produced on a glass substrate with the structure shown in FIG. 5, and the FET output characteristics were measured. The film thickness of PSQ was 50 nm, and the electric field strength was calculated with this film thickness. Pentacene on the PSQ film is deposited at room temperature at a deposition rate of 8 Å / s.
2.5 mm, and the carriers are holes. A voltage was applied up to 5 MV / cm as the electric field strength, but no leakage current was observed. FIG. 6 shows the FET output characteristics. The mobility was 1.80 × 10 ⁻³ [cm ² / Vs], and the on / off ratio was 868.

By applying the composition for semiconductor insulating film containing the polyorganosilsesquioxane having methacryloxy group or acryloxy group of the present invention and combining radical polymerization of vinyl group and condensation polymerization of alkoxy group, it becomes insoluble in organic solvent. A pentacene organic transistor formed using a silicone insulating film showed good device characteristics. Therefore, in the production of an electronic paper or flexible display electrical circuit using a substrate having low heat resistance, the composition for a semiconductor insulating film containing the polyorganosilsesquioxane having a methacryloxy group or an acryloxy group of the present invention is used. It is expected that

Claims (4)

The composition for semiconductor insulating films which mixes a polymerization initiator with polyorgano silsesquioxane represented by General formula (1), and mix | blends the organic solvent.
(However, l, m, and n are positive integers, R ₁ is an aryl group, R ₂ is an alkyl group, and R ₃ is a methacryloxy group or an acryloxy group represented by the general formula (2).
(Wherein R ₅ is a hydrogen atom or a methyl group, R ₆ is an unsubstituted or substituted alkyl group having 1 to 18 carbon atoms), and R ₄ is selected from hydrogen, a methyl group, and an ethyl group Shall be. ) The composition of claim 1 comprising a vinyl monomer. A film forming method comprising applying the composition according to claim 2 and performing a composite curing treatment by radical polymerization of vinyl groups and condensation polymerization of terminal alkoxy groups. A polyorganosilsesquioxane-based insulating film which is insoluble in an organic solvent produced by the method according to claim 3.