Positive photosensitive siloxane composition and cured film formed using same
阅读说明：本技术 正型感光性硅氧烷组合物以及使用其而形成的固化膜 (Positive photosensitive siloxane composition and cured film formed using same ) 是由 吉田尚史 高桥惠 谷口克人 于 2018-04-25 设计创作，主要内容包括：[目的]本发明提供一种可形成具有高的透射率的固化膜的正型感光性组合物。[手段]一种正型感光性硅氧烷组合物,其包含聚硅氧烷、重氮基萘醌衍生物、包含季铵结构并且可与前述聚硅氧烷相互作用的添加剂、以及溶剂。在添加剂与聚硅氧烷之间,在曝光之前存在有相互作用,但是利用曝光而使得该相互作用失去。([ problem ] to provide a positive photosensitive composition capable of forming a cured film having high transmittance. [ means ] A positive photosensitive siloxane composition comprising a polysiloxane, a diazonaphthoquinone derivative, an additive that contains a quaternary ammonium structure and can interact with the polysiloxane, and a solvent. There is an interaction between the additive and the polysiloxane prior to exposure, but this interaction is lost by exposure.)
1. A positive photosensitive siloxane composition comprising:
(I) a polysiloxane comprising a repeating unit represented by the following general formula (Ia):
in the formula (I), the compound is shown in the specification,
R1c represents hydrogen, 1 to 3 valency1～30A linear, branched or cyclic, saturated or unsaturated aliphatic hydrocarbon group, or a C having a valence of 1 to 36～30The aromatic hydrocarbon group of (a) is,
in the aliphatic hydrocarbon group and the aromatic hydrocarbon group, 1 or more methylene groups are substituted or unsubstituted with an oxy group, an imide group or a carbonyl group, 1 or more hydrogen groups are substituted or unsubstituted with a fluorine, a hydroxyl group or an alkoxy group, and 1 or more carbon groups are substituted or unsubstituted with silicon, and
R1in the case of a 2-or 3-valent radical, R1Si contained in the plurality of repeating units are connected to each other,
(II) diazonaphthoquinone derivatives,
(III) an additive selected from the group consisting of compounds containing quaternary ammonium structures, and
(IV) a solvent.
2. The composition of claim 1, wherein the polysiloxane further comprises a repeating unit represented by the following general formula (Ib):
3. the composition according to claim 1 or 2, wherein the film formed after pre-baking the polysiloxane has a dissolution rate of 2.38 wt% aqueous tetramethylammonium hydroxide solution
4. The composition according to any one of claims 1 to 3, wherein the content of the nitrogen cation in the additive (III) is from 0.0005 to 0.05 parts by weight relative to 100 parts by weight of the polysiloxane.
5. The composition according to any one of claims 1 to 4, wherein the additive (III) is represented by the following general formula (III-i):
in the formula, RaEach independently being linear, branched or cyclic, C1～20Alkyl of (C)6～20Aryl of, or C7～20Arylalkyl of 4RaAt least one of them is C1～3And is an alkyl group of
X-Is a halide, carboxylate, nitrate, sulfonate, or bisulfate ion.
6. A cured film comprising the positive photosensitive siloxane composition according to any one of claims 1 to 5.
7. The cured film according to claim 6, which has a transmittance of 90% or more with respect to light having a wavelength of 400 nm.
8. An electronic device comprising the cured film according to claim 6 or 7.
Technical Field
The present invention relates to a positive photosensitive siloxane composition. The present invention also relates to a cured film formed from the positive photosensitive siloxane composition, and an element having the cured film.
Background
In the field of displays and optics, a coating film having high transmittance is generally formed on the surface of a display or the like. For example, a planarizing film is generally formed on the surface of a Flat Panel Display (FPD) or the like. Regarding the material of such a planarizing film, attention has been paid to polysiloxane, and various photosensitive compositions obtained by combining a photosensitizer with this polysiloxane have been reported.
However, although there is a demand for a photosensitive composition having high sensitivity, when the content of the photosensitizer is increased, the following dilemma exists: the transmittance of the formed coating film is lowered by the photosensitizer present in the coating film. For this reason, a photosensitizer capable of achieving high transmittance is also being studied, but there is still room for improvement.
Disclosure of Invention
Problems to be solved by the invention
The present invention is intended to solve the problems to be solved by the prior art as described above, and to provide a positive photosensitive composition capable of forming a cured film having a high residual film ratio, high sensitivity, and high transmittance.
Means for solving the problems
The positive photosensitive siloxane composition of the present invention is characterized by comprising:
(I) a polysiloxane comprising a repeating unit represented by the following general formula (Ia):
in the formula (I), the compound is shown in the specification,
R1c represents hydrogen, 1 to 3 valency1～30A linear, branched or cyclic, saturated or unsaturated aliphatic hydrocarbon group, or a C having a valence of 1 to 36～30The aromatic hydrocarbon group of (a) is,
in the aliphatic hydrocarbon group and the aromatic hydrocarbon group, 1 or more methylene groups are substituted or unsubstituted with an oxy group, an imide group or a carbonyl group, 1 or more hydrogen groups are substituted or unsubstituted with a fluorine, a hydroxyl group or an alkoxy group, and 1 or more carbon groups are substituted or unsubstituted with silicon, and
R1in the case of a 2-or 3-valent radical, R1Si contained in the plurality of repeating units are connected to each other,
(II) diazonaphthoquinone derivatives,
(III) an additive selected from the group consisting of compounds containing quaternary ammonium structures, and
(IV) a solvent.
The cured film of the present invention is characterized by being formed from the positive photosensitive siloxane composition.
The electronic device (device) of the present invention is characterized by comprising the cured film.
ADVANTAGEOUS EFFECTS OF INVENTION
According to the positive photosensitive composition of the present invention, a cured film having a high residual film ratio, high sensitivity, and high transmittance can be formed, which is suitable for use as a protective film or the like of an electronic device.
Detailed Description
The embodiments of the present invention will be described in detail below.
In the present specification, when numerical ranges are expressed using "a to B", they include both endpoints a and B, and the units are common unless otherwise specified. For example, 5 to 25 mol% means 5 mol% or more and 25 mol% or less.
In the present specification, "C" or "C" is usedx～y”、“Cx～CyAnd CxThe expression "and the like" indicates the number of carbon atoms in a molecule or a substituent. For example, "C1～6The alkyl group "represents an alkyl group having 1 to 6 carbons (e.g., methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, etc.). The term "fluoroalkyl" as used herein refers to a fluoroalkyl group in which 1 or more hydrogens in an alkyl group are substituted with fluorine, and the term "fluoroaryl" refers to a fluoroaryl group in which 1 or more hydrogens in an aryl group are substituted with fluorine.
In the present specification, unless otherwise specified, the term "alkyl" refers to a linear or branched alkyl group, and the term "cycloalkyl" refers to an alkyl group having a cyclic structure. A group obtained by substituting a linear or branched alkyl group with a cyclic structure is also referred to as "cycloalkyl". Further, "hydrocarbon group" means a monovalent or divalent or higher group containing carbon and hydrogen, and if necessary, oxygen or nitrogen. The "aliphatic hydrocarbon group" means a straight-chain, branched-chain or cyclic aliphatic hydrocarbon group, and the "aromatic hydrocarbon group" includes an aromatic ring and has an aliphatic hydrocarbon group as a substituent as required. These aliphatic hydrocarbon groups and aromatic hydrocarbon groups contain fluorine, oxygen, hydroxyl groups, amino groups, carbonyl groups, silyl groups, or the like, as required.
In the present specification, in the case where the polymer has a plurality of kinds of repeating units, these repeating units are copolymerized. These copolymers may be any of alternating copolymers, random copolymers, block copolymers, graft copolymers, or mixtures thereof, as long as they are not particularly limited.
In this specification, the unit of temperature is in degrees centigrade unless otherwise specified. For example, "20 ℃ C" means 20 ℃ C.
< Positive photosensitive Silicone composition >
The positive photosensitive siloxane composition of the present invention comprises:
(I) polysiloxane, and,
(II) diazonaphthoquinone derivatives,
(III) specific additives,
(IV) a solvent, and
(V) optional ingredients.
These components are described below.
[ (I) polysiloxanes ]
"polysiloxane" refers to a polymer having a main chain of Si-O-Si bonds (siloxane bonds). In the present specification, the polysiloxane also includes a polysiloxane represented by the general formula (RSiO)1.5)nThe silsesquioxane polymer is shown.
The polysiloxane of the present invention has a repeating unit represented by the following general formula (Ia).
In the formula, R1C represents hydrogen, 1 to 3 valency1～30A linear, branched or cyclic, saturated or unsaturated aliphatic hydrocarbon group, or a C having a valence of 1 to 36～30In the aliphatic hydrocarbon group and the aromatic hydrocarbon group, 1 or more methylene groups are substituted or unsubstituted with an oxy group, an imide or a carbonyl group, 1 or more hydrogen groups are substituted or unsubstituted with a fluorine, a hydroxyl group or an alkoxy group, and 1 or more carbon groups are substituted or unsubstituted with silicon, R is1In the case of a 2-or 3-valent radical, R1Si contained in the plurality of repeating units are connected to each other.
R1In the case of monovalent radicals, as regards R1Examples thereof include (i) an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group, (ii) an aryl group such as a phenyl group, a tolyl group, and a benzyl group, (iii) a fluoroalkyl group such as a trifluoromethyl group, a 2,2, 2-trifluoroethyl group, and a 3,3, 3-trifluoropropyl group, (iv) a fluoroaryl group, (v) a cycloalkyl group such as a cyclohexyl group, (vi) a nitrogen-containing group having an amino group or an imide structure such as a glycidyl group, an isocyanate group, and an amino group, and (vii) an oxygen-containing group having an epoxy structure, an acryloyl structure. Preferably methyl, ethyl, propyl, butyl,Pentyl, hexyl, phenyl, tolyl, glycidyl, isocyanate groups. As the fluoroalkyl group, a perfluoroalkyl group is preferable, and a trifluoromethyl group and/or a pentafluoroethyl group is particularly preferable. With respect to R1The methyl group is preferable because it is easy to obtain a raw material, and the cured film has high hardness and high chemical resistance. The phenyl group is preferable because the solubility of the polysiloxane in a solvent is increased and the cured film is less likely to be cracked. R1Having a hydroxyl group, a glycidyl group, an isocyanate group, or an amino group is preferable because adhesiveness to a substrate is improved.
In addition, R1In the case of a divalent or trivalent radical, R1For example, a group containing an alkylene group, an arylene group, a cycloalkylene ring, a piperidine ring, a pyrrolidine ring, an isocyanurate ring, or the like is preferable.
The polysiloxane of the present invention may have a repeating unit represented by the following general formula (Ib) as needed.
The polymer contains silanol at the end.
Such a polysiloxane can be obtained by hydrolyzing and condensing a silane compound represented by the following formula (ia) in the presence of an acidic catalyst or a basic catalyst as necessary.
R1[Si(OR2)3]p(ia)
In the formula (I), the compound is shown in the specification,
p is 1 to 3,
R1c represents hydrogen, 1 to 3 valency1～30A linear, branched or cyclic, saturated or unsaturated aliphatic hydrocarbon group, or a C having a valence of 1 to 36～30In the aliphatic hydrocarbon group and the aromatic hydrocarbon group, 1 or more methylene groups are substituted or unsubstituted with an oxy group, an imide or a carbonyl group, and 1 or more hydrogen groups are substituted or unsubstituted with a fluorine, a hydroxyl group or an alkoxy group, andand more than 1 carbon is substituted or unsubstituted with silicon,
R2is represented by C1～10Alkyl group of (1).
In the case where the silane compound of the formula (Ia) is used as the silane compound, a polysiloxane containing only the repeating unit (Ia) can be obtained. It is to be noted that the polysiloxane can also be obtained by combining a silane compound represented by the following formula (ib) with a silane compound represented by the above formula (ia). When the formula (Ib) is used in this way, a polysiloxane comprising repeating units (Ia) and (Ib) can be obtained.
Si(OR2)4(ib)
Here, 2 or more silane compounds (ia) and (ib) may be used in combination.
Since precipitation of the silane compound or reduction in sensitivity of the formed coating occurs when the compounding ratio of the silane compound (ib) as a raw material of the polysiloxane is high, the compounding ratio of the silane compound (ib) as a raw material of the polysiloxane is preferably 40 mol% or less, and more preferably 20 mol% or less, relative to the number of moles of the silane compound.
The polysiloxane has a weight average molecular weight of usually 500 or more and 25000 or less, and is preferably 1000 or more and 20000 or less from the viewpoint of solubility in an organic solvent and solubility in an alkali developing solution. The weight average molecular weight herein means a polystyrene-equivalent weight average molecular weight, and can be measured by gel permeation chromatography on the basis of polystyrene.
The alkali dissolution rate of the polysiloxane used in the present invention (hereinafter, may be referred to as ADR. details) varies depending on the film thickness of the formed coating film, the developing conditions, the type and the amount of the photosensitizer contained in the composition, but if the film thickness is 0.1 to 10 μm, for example
In the present invention, in order to adjust the sensitivity, it is preferable to use a polysiloxane having a higher ADR than usual and to enlarge the difference in solubility between the exposed portion and the unexposed portion by a specific additive described later. In general, when a pattern is formed by using a polysiloxane having a high ADR, the sensitivity also becomes high in accordance with the high ADR, but the residual film ratio after development tends to be low. However, in the present invention, when a specific additive is combined with a polysiloxane having a high ADR, the residual film ratio can be improved while maintaining a high sensitivity derived from the polysiloxane. In the present invention, the use of a polysiloxane having a high ADR is preferable because the effects of the present invention can be sufficiently obtained. Specifically, the sensitivity can be improved by more than 10%.
The composition of the present invention can be used in combination with at least 2 kinds of polysiloxanes having different alkali dissolution rates, average molecular weights, or the like. With regard to the different polysiloxanes, they can be prepared by varying the catalyst, the reaction temperature, the reaction time or the polymer. In particular, by using a combination of polysiloxanes having different alkali dissolution rates, residual insoluble matters after development can be reduced, pattern collapse can be reduced, and pattern stability can be improved.
Examples of such polysiloxanes include:
(M) the pre-baked film was soluble in 2.38 wt% aqueous TMAH solution at a rate of
Further, the following components may be mixed as necessary:
polysiloxane (L), the pre-baked film of which is soluble in a 5% by weight aqueous TMAH solution at a rate of
Polysiloxane (H) whose pre-baked film has a dissolution rate of 2.38 wt% TMAH in water
thereby obtaining a composition having a desired dissolution rate.
The weight average molecular weights of the polysiloxanes (M), (H), and (L) are as described above.
In order to broaden the aforementioned solubility difference, the compounding ratio of 2 kinds of polysiloxanes having different alkali dissolution rates can be used for adjustment.
The polysiloxane used in the present invention has a branched structure by using the general formula (ia) or (ib) as a raw material. Here, the polysiloxane can be partially made into a linear structure by combining a 2-functional silane compound as a raw material of the polysiloxane, if necessary. However, in applications requiring high temperature resistance, the linear structural moiety is preferably small. Specifically, the linear structure derived from the 2-functional silane in the polysiloxane is preferably 30 mol% or less of the structure of the all-polysiloxane.
[ method for measuring and calculating Alkali Dissolution Rate (ADR) ]
The alkali dissolution rate of the polysiloxane or the mixture thereof was measured and calculated as follows using TMAH aqueous solution as an alkali solution.
The polysiloxane was diluted to 35 wt% in propylene glycol monomethyl ether acetate (hereinafter referred to as "PGMEA") and dissolved at room temperature while stirring with a stirrer for 1 hour. The prepared polysiloxane solution was dropped 1cc onto the center of a silicon wafer having a thickness of 525 μm using a pipette in a clean room at a temperature of 23.0. + -. 0.5 ℃ and a humidity of 50. + -. 5.0% in an atmosphere of 4 inches and a thickness of 525 μm, spin-coated to a thickness of 2. + -. 0.1 μm, and then heated on a hot plate at 100 ℃ for 90 seconds to remove the solvent. The thickness of the coating film was measured by a spectroscopic ellipsometer (manufactured by j.a. woollam).
Then, the silicon wafer having the film was statically immersed in a 6-inch diameter glass petri dish adjusted to 23.0 ± 0.1 ℃ and containing 100ml of a TMAH aqueous solution at a predetermined concentration, and then allowed to stand, and the time until the film disappeared was measured. The dissolution rate was determined by dividing the initial film thickness by the time until the film disappeared in a portion inside 10mm from the wafer edge. When the dissolution rate was significantly retarded, the wafer was immersed in a TMAH aqueous solution for a certain period of time, heated on a hot plate at 200 ℃ for 5 minutes to remove the water incorporated into the film during the dissolution rate measurement, and the film thickness was measured, and the amount of change in film thickness before and after immersion was divided by the immersion time to calculate the dissolution rate. The measurement was carried out 5 times, and the average value of the obtained values was defined as the dissolution rate of polysiloxane.
[ (II) diazonaphthoquinone derivative ]
The silicone composition of the present invention contains a diazonaphthoquinone derivative as a photosensitizer. By using the photosensitive agent in this manner, it is possible to process a cured film patterned by exposure and development and to pattern the cured film without using dry etching or the like, and thus there is an advantage that damage to a circuit and/or a component can be reduced in manufacturing a device or the like.
The positive photosensitive siloxane composition of the present invention contains a diazonaphthoquinone derivative as a sensitizer. Such a positive photosensitive siloxane composition can form a positive photosensitive layer in which an exposed portion is made soluble in an alkali developing solution and is removed by development.
In the present invention, the diazonaphthoquinone derivative used as the photosensitizer is a compound in which naphthoquinone diazide sulfonic acid is bonded to a compound having a phenolic hydroxyl group through an ester bond. The structure thereof is not particularly limited, and an ester compound with a compound having 1 or more phenolic hydroxyl groups is preferred. As the naphthoquinonediazidosulfonic acid, 4-naphthoquinonediazidosulfonic acid or 5-naphthoquinonediazidosulfonic acid can be used. The 4-naphthoquinonediazidosulfonate compound has absorption in the i-line (wavelength 365nm) region and is therefore suitable for i-line exposure. In addition, the 5-naphthoquinone diazide sulfonate compound absorbs in a wide wavelength range, and is therefore suitable for exposure in a wide wavelength range. The 4-naphthoquinonediazidosulfonate compound and the 5-naphthoquinonediazidosulfonate compound are preferably selected according to the wavelength of exposure. The 4-naphthoquinone diazide sulfonate compound and the 5-naphthoquinone diazide sulfonate compound may be mixed and used.
The compound having a phenolic hydroxyl group is not particularly limited, but examples thereof include bisphenol A, BiSP-AF, BisOTBP-A, Bis26B-A, BiSP-PR, BiSP-LV, BiSP-OP, BiSP-NO, BiSP-DE, BiSP-AP, BisOTBP-AP, TriSP-HAP, BiSP-DP, TriSP-PA, BisOTBP-Z, BiSP-FL, TekP-4HBP, TekP-4HBPA and TriSP-TC (trade name, manufactured by chemical industries, Ltd., Japan).
The amount of the diazonaphthoquinone derivative to be added is preferably 1 to 20 parts by weight, more preferably 3 to 15 parts by weight, based on 100 parts by weight of the polysiloxane, although the optimum amount varies depending on the esterification rate of naphthoquinone diazide sulfonic acid, the physical properties of the polysiloxane to be used, the sensitivity required, and the solubility contrast between the exposed portion and the unexposed portion. When the amount of the diazonaphthoquinone derivative added is 1 part by weight or more, the solubility contrast between the exposed portion and the unexposed portion becomes high, and good photosensitivity is obtained. Further, in order to obtain a better solubility contrast, it is preferably 5 parts by weight or more. On the other hand, the smaller the amount of the diazonaphthoquinone derivative added, the more the colorless transparency of the cured film is improved and the higher the transmittance is, which is preferable.
[ (III) specific additives ]
The compositions of the present invention comprise specific additives. With regard to this specific additive (III), compounds which reduce the ADR of the polysiloxane by interaction with the polysiloxane are contemplated. The term "interaction" as used herein refers to intermolecular force interaction such as hydrogen bond, ionic bond, dipole interaction, etc. Such intermolecular force interactions are brought about by specific nitrogen-containing structures. Such additives having a specific nitrogen-containing structure are compounds containing a quaternary ammonium structure. This additive has an effect of increasing the solubility of the polysiloxane in the exposed portion when a pattern is formed by photolithography, and as a result, a high contrast can be obtained without increasing the amount of the photosensitizer.
It is considered that when a coating film is formed using the composition of the present invention, nitrogen contained in the quaternary ammonium structure in the coating film interacts with oxygen constituting polysiloxane to form weak bonds. In general, with respect to a coating film formed from a positive photosensitive composition containing diazonaphthoquinone, diazonaphthoquinone functions as a dissolution inhibitor in an unexposed portion, but in the present invention, it is considered that a specific additive further compensates for this effect. That is, since the interaction between the specific additive and the polysiloxane is such an extent that it is lost by the action of an acid generated in the coating film by exposure, the difference between the dissolution rate of the polysiloxane in the unexposed portion and the dissolution rate of the polysiloxane in the exposed portion becomes large, and as a result, it is considered that the contrast of the obtained pattern becomes strong. According to the mechanism, the specific additive in the present invention can adjust the sensitivity by compensating the function of the sensitizer.
The interaction between the specific additives of the present invention and the polysiloxane, as described above, is preferably present in the absence of exposure to light and is lost by the acid generated upon exposure to light. In order to achieve such a proper interaction, the specific additive preferably has a specific structure. That is, in the case of the additive (III), it must first have a quaternary ammonium structure. The counter anion of the nitrogen cation of the additive having a quaternary ammonium structure is not particularly limited as long as the effect of the present invention is not impaired. However, since the nitrogen cation contained in the quaternary ammonium structure interacts with the polysiloxane, it is preferable to include a counter anion having an appropriate binding strength with the nitrogen cation. Wherein the counter anion is OH-In the case of the above, since there is a possibility that the counter anion may function as a catalyst for silanol condensation, it is preferable to select the counter anion.
In addition, the interaction between the additive (III) and the polysiloxane may be affected by a substituent bonded to the quaternary ammonium or the like. In addition, when all of the substituents bonded to the quaternary ammonium are bulky, the interaction of the nitrogen cation with the polysiloxane may be inhibited. Therefore, it is preferable to select the quaternary ammonium substituent in consideration of such an influence.
Since the additive remains in unexposed portions of the coating film during the formation of the cured film, both the cation and the anion are preferably decomposed or evaporated at a low temperature, for example, at room temperature or at a temperature lower than the curing temperature of the coating film.
Specifically, the additive in the present invention is preferably represented by the following general formula (III-i).
In the formula, RaEach independently is a linear, branched or cyclic C1～20Alkyl of (C)6～20Aryl of, or C7～20Arylalkyl of 4RaAt least one of them is C1～3And is an alkyl group of
X-Is a halide, carboxylate, nitrate, sulfonate, or bisulfate ion. As the carboxylate ion, for example, each ion of succinic acid, citric acid, and acetic acid is cited, and as the sulfonate ion, for example, each ion of trifluoromethanesulfonic acid and p-toluenesulfonic acid is cited. Here, X is-Preferably not OH-。
Here, RaPreferably C1～8Linear alkyl or phenyl of (2), X-Preferably a halide ion, more preferably Cl-。
More specifically, the additive (III) includes the following.
The preferable content of such an additive is determined by the content of nitrogen cations contained in the composition. Specifically, the nitrogen cation content in the additive (III) is preferably 0.0005 to 0.05 parts by weight, more preferably 0.002 to 0.02 parts by weight, based on 100 parts by weight of the polysiloxane.
In the present invention, 2 or more additives (III) may be used in combination.
[ (IV) organic solvent ]
The composition of the present invention comprises an organic solvent. The organic solvent is selected from organic solvents in which the components contained in the composition are uniformly dissolved or dispersed. Specifically, examples of the organic solvent include ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, and ethylene glycol monobutyl ether, diethylene glycol dialkyl ethers such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, and diethylene glycol dibutyl ether, ethylene glycol alkyl ether acetates such as methyl cellosolve acetate and ethyl cellosolve acetate, propylene glycol monoalkyl ethers such as Propylene Glycol Monomethyl Ether (PGME) and propylene glycol monoethyl ether, propylene glycol alkyl ether acetates such as Propylene Glycol Monomethyl Ether Acetate (PGMEA), propylene glycol monoethyl ether acetate, and propylene glycol monopropyl ether acetate, aromatic hydrocarbons such as benzene, toluene, and xylene, ketones such as methyl ethyl ketone, acetone, methyl amyl ketone, methyl isobutyl ketone, and cyclohexanone, and alcohols such as isopropyl alcohol and propylene glycol. These solvents are used alone or in combination of 2 or more. The mixing ratio of the solvent differs depending on the coating method and the film thickness after coating. For example, in the case of spray coating, the amount of the polysiloxane is 90 wt% or more based on the total weight of the optional components, but in the slot coating of a large glass substrate used for the production of a display, the amount is usually 50 wt% or more, preferably 60 wt% or more, usually 90 wt% or less, and preferably 85 wt% or less.
[ (V) optional ingredients ]
In addition, the compositions of the present invention may also contain other optional ingredients as desired. As such optional components, curing aids are listed. The curing assistant used is a compound which generates an acid or a base under the action of light or heat. Specifically, a photoacid generator, a photobase generator, a thermal acid generator, a thermal base generator, a photothermal acid generator, and a photothermal base generator are exemplified. Here, the photothermal acid generator and the photothermal alkali generator may be: a compound that is chemically changed by exposure to light without generating an acid or a base, and thereafter generates an acid or a base by causing bond cleavage under the action of heat. They are selected according to the polymerization or crosslinking reactions utilized in the cured film manufacturing process. Here, the light may be visible light, ultraviolet light, infrared light, or the like. In particular, it is preferable that an acid or an alkali is generated by ultraviolet rays used for manufacturing a thin film transistor.
The amount of the curing aid added varies depending on the kind of the active material generated by decomposition of the curing aid, the amount of the active material generated, the required sensitivity, and the solubility contrast between the exposed portion and the unexposed portion, but is preferably 0.001 to 10 parts by weight, more preferably 0.01 to 5 parts by weight, based on 100 parts by weight of the polysiloxane. When the amount is 0.001 parts by weight or more, the solubility contrast between the exposed portion and the unexposed portion becomes high, and the addition effect becomes good. On the other hand, if the amount of the curing aid added is 10 parts by weight or less, the resultant coating film is inhibited from cracking and from being colored due to decomposition of the curing aid, and the colorless transparency of the coating film is improved.
Examples of the photoacid generator include diazomethane compounds, triazine compounds, sulfonic acid esters, diphenyliodonium salts, triphenylsulfonium salts, sulfonium salts, ammonium salts, phosphonium salts, and sulfonimide compounds.
As the specifically usable photoacid generator including the above-mentioned photoacid generator, there can be mentioned 4-methoxyphenyl diphenylsulfonium hexafluorophosphate, 4-methoxyphenyl diphenylsulfonium hexafluoroarsenate, 4-methoxyphenyl diphenylsulfonium methanesulfonate, 4-methoxyphenyl diphenylsulfonium trifluoroacetate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium tetrakis (pentafluorophenyl) borate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroarsenate, 4-methoxyphenyl diphenylsulfonium-p-toluenesulfonate, 4-phenylthiophenyldiphenylsulfonium tetrafluoroborate, 4-phenylthiophenyldiphenylsulfinyldiphenylsulfonium hexafluorophosphate, triphenylsulfonium methanesulfonate, triphenylsulfonium trifluoroacetate, triphenylsulfonium-p-toluenesulfonate, 4-methoxyphenyl diphenylsulfonium tetrafluoroborate, triphenylsulfonium tetrafluorobor, 4-Phenylthiophenyldiphenylsulfonium hexafluoroarsenate, 4-phenylthiophenyldiphenylsulfonium-p-toluenesulfonate, N- (trifluoromethylsulfonyloxy) succinimide, N- (trifluoromethylsulfonyloxy) phthalimide, 5-norbornene-2, 3-dicarboximido (dicaroxylimido) trifluoromethanesulfonate, 5-norbornene-2, 3-dicarboximido-p-toluenesulfonate, 4-phenylthiophenyldiphenylsulfonium trifluoromethanesulfonate, 4-phenylthiophenyldiphenylsulfonium trifluoroacetate, N- (trifluoromethylsulfonyloxy) diphenylmaleimide, N- (trifluoromethylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2, 3-dicarboximide, N- (trifluoromethylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2, 3-dicarboximido, N- (trifluoromethylsulfonyloxy) bis (meth) imide, N- (trifluoromethylsulfonyloxy) bis (meth) phosphonium, N- (trifluoromethylsulfonyloxy) naphthylimide, and N- (nonafluorobutylsulfonyloxy) naphthylimide, and the like.
Examples of the photobase generator include a polysubstituted amide compound having an amide, a lactam, an imide compound, and a compound having such a structure. As the anion, an ionic photobase generator containing an amide anion, a methide anion (methide anion), a borate anion, a phosphate anion, a sulfonate anion, a carboxylate anion, or the like can also be used.
The photothermal alkali generating agent includes a compound represented by the following general formula (PBG).
Wherein x is an integer of 1 or more and 6 or less,
R1’～R6’each independently hydrogen, halogen, hydroxy, mercapto, thioether, silyl, silanol, nitro, nitroso, sulfino, sulfo, sulfono, phosphino, phosphinyl, phosphono, phosphonate, amino, ammonium, C which may also contain substituents1～20Aliphatic hydrocarbon group of (1), C which may contain a substituent6～22Optionally C1～20Or C which may also contain a substituent6～20An aryloxy group of (1).
Among them, R1’～R4’Particularly preferably hydrogen, hydroxy, C1～6Aliphatic hydrocarbon group of (2), or C1～6Alkoxy of R5’And R6’Hydrogen is particularly preferred.
Or R can also be1’～R4’Wherein 2 or more of them are bonded to form a ring structure. In this case, the cyclic structure may also contain heteroatoms.
In the above formula, N is a constituent atom of a nitrogen-containing heterocycle, the nitrogen-containing heterocycle is a 3-to 10-membered ring, and the nitrogen-containing heterocycle may contain 1 or more and C represented by the formula (PBG)xH2XA substituent different from OH, and may further have C1～20In particular C1～6An aliphatic hydrocarbon group of (1).
R1’～R4’It is preferable to select the exposure wavelength appropriately. For applications to displays, unsaturated hydrocarbon-binding functional groups such as vinyl groups and alkynyl groups, and alkoxy groups and nitro groups, which shift the absorption wavelength to g, h, and i lines, are used, and methoxy groups and ethoxy groups are particularly preferable.
Specifically, the following are listed.
The photothermal alkali generating agent represented by the formula (PBG) is preferably used in a hydrated or solvated state. When the photothermal alkali generating agent is used in an anhydrous state, a sufficient effect may not be obtained. Herein, "anhydrate" refers to a compound that is neither hydrated nor solvated. The method for hydrating or solvating the anhydride of the photothermokalite generator is not particularly limited, and a known method can be used. For example, 10 times or more moles of water is added to the photothermal alkali generator anhydrideOr the solvent is stirred at a temperature of room temperature or higher for about 1 hour. In the case of the solvate, the solvent is preferably soluble in the photothermal base generator and water and has a boiling point lower than that of water, and examples thereof include THF. In addition, C is also preferable6The following alcohols. As for the obtained mixture, excess solvent may be distilled off by using an evaporator, thereby obtaining a hydrate or a solvate. As regards the hydration or solvation of the compound obtained, it is possible to use the infrared absorption spectrum (IR),1H-NMR, differential thermal-thermogravimetric analysis (TG-DTA), etc.
The photothermal alkali generating agent may be mixed and stirred in water or a solvent in an anhydrous state, and the obtained hydrate or solvate may be used without being separated separately.
The composition ratio of water used for hydration or a solvent used for solvation to the photothermal alkali generating agent represented by the formula (PBG) is preferably 0.1 mol or more, and more preferably 1 mol or more, based on 1 mol of the compound of the formula (PBG).
In addition, as the curing aid, a thermal acid generator or a thermal base generator can be used. Examples of the thermal acid generator include salts and/or esters of various aliphatic sulfonic acids and salts thereof, various aliphatic carboxylic acids and salts thereof such as citric acid, acetic acid, and maleic acid, various aromatic carboxylic acids and salts thereof such as benzoic acid and phthalic acid, various amine salts thereof, aromatic diazonium salts, and salts and/or esters of phosphonic acid and salts thereof, which generate organic acids. Among the thermal acid generators, in particular, a salt of an organic acid and an organic base is preferable, and a salt of a sulfonic acid and an organic base is more preferable.
Preferable sulfonic acids include p-toluenesulfonic acid, benzenesulfonic acid, p-dodecylbenzenesulfonic acid, 1, 4-naphthalenedisulfonic acid, and methanesulfonic acid. These acid generators may be used alone or in combination.
Examples of the thermal base generator include compounds that generate bases such as imidazole, tertiary amine, and quaternary ammonium, and mixtures thereof. Examples of the liberated base include imidazole derivatives such as N- (2-nitrobenzyloxycarbonyl) imidazole, N- (3-nitrobenzyloxycarbonyl) imidazole, N- (4-nitrobenzyloxycarbonyl) imidazole, N- (5-methyl-2-nitrobenzyloxycarbonyl) imidazole and N- (4-chloro-2-nitrobenzyloxycarbonyl) imidazole, and 1, 8-diazabicyclo [5.4.0] undec-7-ene. These alkali generators may be used alone or in combination with an acid generator.
As other optional components, surfactants and the like are exemplified.
The surfactant is preferably used because it improves coatability. Examples of the surfactant that can be used in the silicone composition of the present invention include nonionic surfactants, anionic surfactants, and amphoteric surfactants.
Examples of the nonionic surfactant include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene oleyl ether and polyoxyethylene cetyl ether and/or polyoxyethylene fatty acid diesters, polyoxyethylene fatty acid monoesters, polyoxyethylene polyoxypropylene block polymers, acetylene alcohols (acetylene alcohols), acetylene glycols (acetylenic glycols), polyethoxylates of acetylene alcohols, and polyethoxylates of acetylene glycols, fluorine-containing surfactants, such as fluoro (product name, manufactured by sumitomo 3M co., ltd.), Megafac (product name, manufactured by DIC corporation), Surflon (product name, manufactured by asahi nitro corporation), and organosiloxane surfactants, such as KP341 (product name, manufactured by seiko chemical industries). Examples of the alkynediol include 3-methyl-1-butyn-3-ol, 3-methyl-1-pentyn-3-ol, 3, 6-dimethyl-4-octyn-3, 6-diol, 2,4,7, 9-tetramethyl-5-decyne-4, 7-diol, 3, 5-dimethyl-1-hexyn-3-ol, 2, 5-dimethyl-3-hexyn-2, 5-diol, and 2, 5-dimethyl-2, 5-hexynediol.
Further, examples of the anionic surfactant include ammonium salts or organic amine salts of alkyl diphenyl ether disulfonic acid, ammonium salts or organic amine salts of alkyl diphenyl ether sulfonic acid, ammonium salts or organic amine salts of alkylbenzene sulfonic acid, ammonium salts or organic amine salts of polyoxyethylene alkyl ether sulfate ester, ammonium salts or organic amine salts of alkyl sulfate ester, and the like.
Further, as the amphoteric surfactant, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolium betaine, lauramidopropyl hydroxysultaine, and the like are exemplified.
These surfactants may be used alone or in combination of 2 or more, and the compounding ratio thereof is usually 50 to 10,000ppm, preferably 100 to 5,000ppm, based on the total weight of the photosensitive silicone composition.
< cured film and electronic device having the same >
The cured film of the present invention can be produced by applying the positive photosensitive siloxane composition to a substrate and curing the composition.
The coating film of the composition of the present invention can be formed by any method known in the art as a method for coating a photosensitive siloxane composition, such as dip coating, roll coating, bar coating, brush coating, spray coating, blade coating, flow coating, spin coating, and slit coating. The base material may be formed on an appropriate substrate such as a silicon substrate, a glass substrate, or a resin film. In the case where the substrate is a film, gravure coating may also be performed. A drying step of the coating film may be separately provided as desired. The coating film can be formed to a desired film thickness by repeating coating once or twice or more as necessary.
After the coating film of the photosensitive siloxane composition of the present invention is formed, the coating film is preferably subjected to prebaking (heat treatment) in order to dry the coating film and reduce the residual amount of the solvent. The pre-baking step is generally performed at a temperature of 70 to 150 ℃, preferably 90 to 120 ℃, for 10 to 180 seconds, preferably 30 to 90 seconds, when performed on a hot plate, and for 1 to 30 minutes when performed on a clean oven.
Since the composition of the present invention is photosensitive, a patterned cured film can be formed. A method of forming this pattern will be explained. The desired pattern is formed by forming a coating film of the composition of the present invention, subjecting the coating film to a pre-baking treatment, and then irradiating the coating film with light in a pattern.
As such a light source, a lamp such as a high-pressure mercury lamp, a low-pressure mercury lamp, a metal halide, or xenon, a laser diode, or an LED may be used. For the irradiation light, ultraviolet rays such as g-ray, h-ray, and i-ray are generally used. In addition to ultra-fine processing such as semiconductor processing, light of 360 to 430nm (high-pressure mercury lamp) is generally used for patterning of several μm to several tens of μm. In the case of a liquid crystal display device, light of 430nm is often used. The energy of the irradiation light is generally 10 to 2000mJ/cm, although it is also related to the light source and the initial film thickness2Preferably 20 to 1000mJ/cm2. The energy of the irradiated light is less than 10mJ/cm2When the composition is not sufficiently decomposed, it is higher than 2000mJ/cm2In this case, the exposure may become excessive, which may cause halo (halo) to occur.
For the pattern-wise irradiation, a general photomask may be used, and such a photomask is known to those skilled in the art. The environment at the time of irradiation may be usually an ambient atmosphere (in the atmosphere) or a nitrogen atmosphere. In addition, when a film is formed over the entire surface, the entire surface may be exposed. In the present invention, the term "pattern film" also includes a case where a film is formed on the entire surface.
As the developer used for development, any developer conventionally used for development of photosensitive siloxane compositions can be used. Preferred developing solutions include aqueous solutions of basic compounds such as tetraalkylammonium hydroxide, choline, alkali metal hydroxide, alkali metal metasilicate (hydrate), alkali metal phosphate (hydrate), ammonia, alkylamine, alkanolamine, heterocyclic amine, and the like, that is, alkali developing solutions, and a particularly preferred alkali developing solution is an aqueous solution of tetramethylammonium hydroxide. These alkali developing solutions may further contain a water-soluble organic solvent such as methanol or ethanol, or a surfactant, as necessary. After development with an alkali developing solution, washing with water is generally performed. Thereafter, a flood exposure (flood exposure) is generally performed. The entire surface exposure is preferably performed when transparency is required because the unreacted diazonaphthoquinone derivative remaining in the film is photolyzed to further improve the light transparency of the film. In the case where a photoacid generator or a photobase generator is selected as the curing assistant, an acid or a base is generated by the light of radiation in this entire surface exposure step. When a photo-thermal acid generator or a photo-thermal alkali generator is selected as the curing aid, the chemical structures of the photo-thermal acid generator and the photo-thermal alkali generator are changed in the entire exposure step.
The whole exposure method uses an ultraviolet-visible exposure machine such as PLA with a thickness of 100-2,000 mJ/cm2The entire surface was exposed to light (converted into exposure of 365nm wavelength).
After the development, the pattern film is heated to cure the coating film. The heating conditions may be any temperature capable of curing the coating film, and are usually 150 to 400 ℃, preferably 200 to 350 ℃. Unreacted silanol tends to remain at 150 ℃ or lower. In general, the polarity of silanols tends to induce high dielectric constants. Therefore, in the case where it is desired to obtain a low dielectric constant, it is preferable to perform curing at 200 ℃ or higher.
The cured film of the present invention has high transmittance. Specifically, the transmittance with respect to light having a wavelength of 400nm is preferably 90% or more, and more preferably 95% or more.
The cured film thus formed can be suitably used in various fields, for example, as a planarizing film, an interlayer insulating film, a transparent protective film, or the like for various devices such as a Flat Panel Display (FPD), or as an interlayer insulating film for low-temperature polysilicon, a buffer coating film for IC chips, or the like. In addition, the cured film can also be used as an optical device material or the like.