JP2001151884A - Thermosetting polyether resin and production method, thereof and coating solution for forming insulation film layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyether resin that can be used as a layer insulation material having excellent chemical resistance and high layer strength, a method of manufacturing the same and a paint for forming insulating layer. SOLUTION: [I] A thermosetting polyether resin that is obtained by effecting polycondensation reaction between a dihalide and a bisphenol and introducing a functional group causing the crosslinking reaction with heat into the resultant polyether having the weight-average molecular weight of 1,000-50,000 calculated as polystyrene according to the resultant GPC; [II] A method of manufacturing a thermosetting polyether resin described in [I] wherein a dihalide and a bisphenol are polycondensed, metalating the resultant polyether resin, followed by effecting the substitution reaction with a halide bearing a functional group that can cause crosslinking reaction in the molecule; [III] A coating liquid for forming insulation layers including the thermosetting polyether resin described in [I].

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a thermosetting polyether resin used for insulation and coating in various electronic devices, a method for producing the same, and a coating liquid containing the same. More specifically, the present invention relates to a thermosetting polyether resin having low dielectric constant, high heat resistance, chemical resistance and high film strength, a method for producing the same, and formation of an insulating film containing the thermosetting polyether resin. Related to coating liquid.

[0002]

2. Description of the Related Art An increase in the speed of an LSI is achieved by miniaturization of transistors constituting the LSI. In recent years, due to the miniaturization, wiring intervals have been reduced, and delay of transmission signals (wiring delay) and crosstalk between adjacent wirings have become remarkable.
These are serious problems that hinder high performance of the LSI itself. As a solution to this problem, it has been studied to lower the relative permittivity of the insulating film filling the space between the wirings.
SOG (Spi) conventionally used as an insulating film
A non-glass film is an effective material because an insulating film can be easily formed on a device substrate by coating and baking, but its relative dielectric constant is 3.0 to 3.9, and the dielectric constant is sufficiently low. Not a rate. 0.25μm between wires
In the following, an insulating film having a relative permittivity of preferably less than 3.0 is required.

[0003] In order to increase the speed of an LSI, an insulating film having a low dielectric constant filling between wirings is indispensable. On the other hand, chemical resistance and mechanical strength of the insulating film are very important in the manufacturing process. In particular, when patterning by lithography after applying and baking an insulating film on the wafer,
Since there is a step of contacting with a developing solution (alkali aqueous solution, organic solvent) and a step of contacting with a stripping agent containing an organic amine when stripping the resist, it is essential that the insulating film can withstand these agents. . In addition, since there is a physical operation such as chemical mechanical polishing, the insulating film is required to have mechanical strength, and strong adhesion is required to the coating on which the insulating film is formed. However, when a known polyether resin for forming an insulating film, for example, a polyether polymer obtained by the Ullmann reaction is used, the problem is that the chemical resistance or the film strength is insufficient. And its improvement was required.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polyether resin which can be used as an interlayer insulating film material having excellent chemical resistance and film strength while maintaining a low dielectric constant.
An object of the present invention is to provide a coating method for forming an insulating film having excellent chemical resistance and film strength while maintaining a low dielectric constant.

[0005]

Means for Solving the Problems The present inventors have studied various resins, and as a result, by introducing a functional group which causes a cross-linking reaction by heating to a specific polyether resin, it has excellent chemical resistance, The inventors have found that the film strength is increased, and have completed the present invention.

That is, the present invention provides a polycondensation of [1] a dihalogenated compound and a bisphenol compound, and the resulting polystyrene-equivalent weight average molecular weight by GPC of 100
The present invention relates to a thermosetting polyether resin obtained by introducing a functional group which causes a cross-linking reaction by heating to a polyether of 0 to 50,000 or less. Here, heating generally refers to applying a temperature of room temperature or higher to the resin, and a cross-linking reaction refers to a reaction in which a chemical bond is generated within and / or between molecules to generate a three-dimensional structure. Furthermore,
The present invention relates to [2] the thermosetting polyether resin according to [1], wherein the polyether before introducing a functional group causing a crosslinking reaction is represented by the following formula (1). (In the formula, A is selected from one or more of the following groups.

B has a structure represented by the following formula (2). Q ^{1 to} Q ¹² each independently represent a hydrogen atom,
It represents an alkyl group of 10, a cycloalkyl group having 4 to 10 carbon atoms, and an arylene group which may be substituted. Q
¹³ represents an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 8 carbon atoms, or an arylene group which may be substituted. Z is selected from a hydrogen atom, a chlorine atom, a bromine atom, an iodine atom, a —OZ ¹ group, and a —N (Z ² ) (Z ³ ) group.
Z ^{1 to} Z ³ each independently represent a hydrogen atom, a carbon number of 1 to 1;
It is selected from an alkyl group having 0, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, and a group having an ether group having 1 to 10 carbon atoms. R ^{1 to} R ⁸ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms,
10 to 10 cycloalkyl groups, optionally substituted arylene groups, methoxy groups, and ethoxy groups. X
Is selected from the group consisting of a single bond, a hydrocarbon group having 1 to 20 carbon atoms, an ether group, a ketone group and a sulfone group. However, at least one of Q ^{1 to} Q ¹² and R ^{1 to} R ⁸ is a hydrogen atom. Further, the present invention provides a method for polycondensation of [III] a dihalogenated compound and a bisphenol compound, metallizing the obtained polyether resin, and subsequently using a halogenated compound having a functional group which causes a crosslinking reaction in the molecule. The present invention relates to the method for producing a thermosetting polyether resin according to [I] or [II], comprising a step of performing a substitution reaction. Further, the present invention relates to [IV] a coating liquid for forming an insulating film containing the thermosetting polyether resin described in the above [I] or [II].

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION As R ^{1 to} R ^{8 in} the above formula (2),
As the independently selected alkyl group having 1 to 10 carbon atoms, methyl group, ethyl group, n-propyl group, iso-
Examples thereof include a propyl group, a butyl group, a pentyl group, and a hexyl group (each including various isomers). Examples of the cycloalkyl group having 4 to 10 carbon atoms include a cyclopentyl group, a cyclohexyl group, a bicyclobutane group,
Examples include a spiropentane group, a bicyclo [3.1.0] hexane group, a cubane group, and a norbornene group. Among them, t-butyl group,
Iso-butyl, cyclopentyl and cyclohexyl are preferred.

The hydrocarbon group having 1 to 20 carbon atoms selected as X in the above formula (2) includes —CH ₂ —, —CH
(CH ₃ ) —, —C (CH ₃ ) ₂ —, —C (CH ₃ ) ₂ —C ₆
H ₆ —C (CH ₃ ) ₂ — (including various isomers), —CH
= CH-, And the like, but are not limited to these.

The functional group which causes a crosslinking reaction upon heating introduced into the above formula (1) includes a functional group containing an unsaturated hydrocarbon group such as an allyl group, a propenyl group, a propargyl group, a butenyl group, and a trimethoxysilyl group. And alkoxysilyl groups such as triethoxysilyl group, cyanate group, epoxy group and the like. In particular, an unsaturated hydrocarbon group and a silyl group having an unsaturated group hydrocarbon group are preferable because the electron polarizability after curing is small and the electrical characteristics after the cross-linking reaction does not deteriorate.

Among them, as the functional group that causes the crosslinking reaction, an allyl group, a propargyl group, and a functional group represented by the formula (3) are more preferable for the purpose of suppressing the deterioration of the electric characteristics. (Wherein, T ¹ is .T ² is 1 carbon atoms selected from an alkenyl group, an alkynyl group having 2 to 10 carbon atoms having 2 to 10 carbon atoms
Selected from an alkyl group of 10 to 10 and an arylene group which may be substituted. n is an integer of 1 or more and 3 or less. T ¹
May be the same or different from each other when T ²
May be the same or different. )

The thermosetting polyether resin of the present invention is obtained by polycondensing a dihalogenated compound and a bisphenol compound, and has a weight average molecular weight in terms of polystyrene of not less than 1,000 and not more than 50,000, preferably not more than 100,000 by GPC.
It is characterized by being obtained by introducing a functional group which causes a cross-linking reaction by heating to a polyether of 0 to 30,000. When the weight average molecular weight in terms of polystyrene is less than 1,000, heat resistance deteriorates, and when it exceeds 50,000, the viscosity becomes extremely high when dissolved in the organic solvent. May worsen. The thermosetting polyether resin of the present invention has a weight average molecular weight in terms of polystyrene by GPC of preferably 1,000 or more and 60,000 or less, more preferably 1,000 or more and 40,000 or less. In a preferred embodiment, the polyether of the repeating unit represented by the formula (1) is obtained by polymerizing a dihalogenated compound represented by the formula (4) and a bisphenol represented by the formula (5) under alkaline conditions. It is obtained by introducing a functional group which causes the above-mentioned cross-linking reaction into the polyether. MAM (4) (where M is any one of a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. A is the same as defined above.) (In the formula, R ^{1 to} R ⁸ and X are the same as defined in the formula (2), respectively.)

In order to introduce a functional group capable of causing a crosslinking reaction by heating into a polyether resin obtained by a polycondensation reaction between a dihalogenated compound and a bisphenol compound, the polyether resin is metallized, that is, the fragrance in the polyether resin is changed. A method in which a hydrogen atom bonded to an aromatic ring is subjected to a substitution reaction with a metal, followed by a substitution reaction using a halogenated compound containing a functional group that causes a crosslinking reaction. The solvent used in the metalation reaction is not particularly limited, but ether, tetrahydrofuran and the like are preferred from the viewpoint of solubility and reactivity of the polyether resin.

The reactant used in the metallization reaction is not particularly limited, and examples thereof include metallic lithium, metallic sodium, n-butyllithium, sec-butyllithium, tert-butyllithium and the like. Also, phenyllithium, sodium naphthalene and alkyl sodium can be used. Among them, n-butyllithium which is available as an n-hexane solution is preferable from the viewpoint of workability.

The reactant used in the reaction for introducing a functional group that causes a crosslinking reaction is achieved by using a halogenated compound corresponding to the functional group. For example, in the case of introducing an allyl group, allyl chloride, allyl bromide, allyl iodo, in the case of introducing a propagyl group, propargyl chloride, propagyl bromide, and in the case of a functional group represented by the formula (4), a compound represented by the formula (5) Is used as an industrially available raw material. (T1, T2, and n are the same as the definitions in the expression (3). M is the same as the definition in the expression (4).)

The polyether into which a functional group capable of causing a crosslinking reaction by heating is subjected to filtration, or washing of a solution dissolved in a water-insoluble solvent with water or the like to remove metal,
It is provided as a coating liquid for forming an insulating film dissolved in an organic solvent except for an inorganic substance such as a salt substance. The organic solvent at this time may be the solvent used for the metallization reaction or another solvent. Examples of the solvent include methanol, ethanol, isopropyl alcohol, alcohols such as 2-methoxyethanol, ethyl acetate, n-butyl acetate, isobutyl acetate, esters such as propylene glycol monomethyl ether acetate, 2-pentanone, 2-heptanone, Examples thereof include ketones such as acetylacetone, ethers such as diethyl ether and dibutyl ether, and phenol ethers such as anisole and phenetole.

The concentration at the time of dissolving the polyether is usually 5 to 4
It is adjusted to 0% by weight, more preferably 10 to 20% by weight. If the concentration is lower than this concentration range, the film thickness at the time of spin coating becomes too thin, and several coatings are required to obtain a desired film thickness. When the concentration is high, the viscosity increases, so that the liquid supply during coating becomes complicated.

The coating liquid for forming an insulating film according to the present invention is characterized by containing a thermosetting polyether resin, and has chemical resistance,
Additives such as a surfactant and an antioxidant can be used as long as the film strength is not impaired. It is also possible to add a catalyst such as a peroxide or an azo compound to lower the curing temperature of the thermosetting group having an unsaturated group.

The coating liquid for forming an insulating film of the present invention is applied to a semiconductor device on a substrate by spin coating or immersion, and is cured by heat treatment, light irradiation or the like as necessary to obtain a low dielectric constant insulating film. Can be formed.

[0020]

EXAMPLES The present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto. Synthesis Example 1 In a 500-ml four-necked flask, 21.6 g (0.05 mol) of 1,1-bis (4-hydroxy-cyclohexylphenyl) cyclohexylidene, 4.0 g of caustic soda,
70.0 g of benzophenone and 50.0 g of toluene were charged and subjected to reflux dehydration. After the dehydration was completed, 15.6 g (0.05 mol) of dibromobiphenyl was added. Further, a solution in which 0.05 g of cuprous chloride was dissolved in 5 g of pyridine was added, and the mixture was reacted at an internal temperature of 185 ° C. for 6 hours.
After cooling to room temperature, acetic acid 10
The reaction solution was added to the mixed solution of g, and the product was precipitated. The precipitated crystals were filtered and washed with a large amount of methanol to obtain polyether. The polyether had a weight average molecular weight in terms of polystyrene of 3000. Next, the obtained polyether resin was adjusted to a solid content of 15% by weight with anisole. This is designated as a resin solution A.

Synthesis Example 2 In a 300 ml four-necked flask purged with nitrogen, 4 g of the polyether resin obtained in Synthesis Example 1 as a raw material and 100 ml of THF as a solvent were added to dissolve the polyether resin. 21.5 ml of n-butyllithium (1.6 Mn-hexane solution) was added, and the mixture was stirred for 1 hour under a nitrogen stream. Then, 4.0 g of allyl bromide was added, and the stirring was further continued for about 1 hour. After completion of the reaction, 650 g of methanol and 20
g of the reaction solution was charged into the mixed solvent to precipitate a high molecular weight substance, which was filtered, washed with methanol and washed with water to obtain a white powdery product. The weight average molecular weight in terms of polystyrene by GPC was 4,000. ¹ H-N
The introduction of the allyl group was confirmed by MR and IR measurements. Next, the polymer was adjusted to a solid content of 15% by weight with anisole. This is designated as a resin solution B.

Example 1, Comparative Example 1 The resin solution obtained in the synthesis example was filtered through a 0.2 μm filter. This is transferred to a 4-inch silicon wafer at a rotation speed of 20.
After spin coating at 00 rpm and baking at 150 ° C. for 1 minute, heat treatment was performed at 350 ° C. for 30 minutes in a nitrogen atmosphere. The film thickness was observed with an optical film thickness meter (Nanometric 210, manufactured by Nanometrics Co., Ltd.), and the relative dielectric constant was measured by a mercury probe method at a CV measurement at an operating frequency of 1 MHz (manufactured by SSM, (SSM495 type). The mechanical strength of the insulating film is measured by a stud-pull test for adhesion to the silicon wafer (Sebastian V type manufactured by QuadGroup).
Was measured. As the chemical resistance, the resist developer is immersed in toluene (negative resist developer), 2.5% tetramethylammonium hydroxide (positive resist developer), and anisole (resin solution solvent) for 10 minutes at room temperature. Before and after the immersion in ALEG310 (manufactured by Marine Clot Baker) as a resist stripping solution at 70 ° C. for 10 minutes, the appearance was examined with a 25 × optical microscope. Table 1 shows the results.

[Table 1]

[0023]

The polyether resin of the present invention maintains a low dielectric constant, is excellent in chemical resistance and film strength, can be suitably used as an insulating film material, and contains the polyether resin. A suitable insulating film can be formed using the coating liquid for forming an insulating film, and a useful semiconductor device can be obtained.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Choi Hyun-chul 6 Kitahara, Tsukuba City, Ibaraki Prefecture Sumitomo Chemical Co., Ltd.

Claims (8)

[Claims] 1. A dihalogenated compound and a bisphenol compound are polycondensed, and a polyether having a weight average molecular weight in terms of polystyrene of 1,000 to 50,000 obtained by GPC is introduced with a functional group which causes a crosslinking reaction by heating. A thermosetting polyether resin. 2. The thermosetting polyether resin according to claim 1, wherein the polyether before introducing a functional group which causes a crosslinking reaction is represented by the following formula (1). (In the formula, A is selected from one or more of the following groups. B has a structure represented by the following formula (2). Q ^{1 to} Q ¹² each independently represent a hydrogen atom,
It represents an alkyl group of 10, a cycloalkyl group having 4 to 10 carbon atoms, and an arylene group which may be substituted. Q
¹³ represents an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 8 carbon atoms, or an arylene group which may be substituted. Z is selected from a hydrogen atom, a chlorine atom, a bromine atom, an iodine atom, a —OZ ¹ group, and a —N (Z ² ) (Z ³ ) group.
Z ^{1 to} Z ³ each independently represent a hydrogen atom, a carbon number of 1 to 1;
It is selected from an alkyl group having 0, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, and a group having an ether group having 1 to 10 carbon atoms. R ^{1 to} R ⁸ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms,
10 to 10 cycloalkyl groups, optionally substituted arylene groups, methoxy groups, and ethoxy groups. X
Is selected from the group consisting of a single bond, a hydrocarbon group having 1 to 20 carbon atoms, an ether group, a ketone group and a sulfone group. However, at least one of Q ^{1 to} Q ¹² and R ^{1 to} R ⁸ is a hydrogen atom. ) 3. The thermosetting composition according to claim 2, wherein at least one of R ^{1 to} R ⁸ is an alkyl group having 4 to 10 carbon atoms or a cycloalkyl group having 4 to 10 carbon atoms. Polyether resin. 4. The thermosetting polyether resin according to claim 1, wherein the functional group causing the crosslinking reaction is a functional group containing an unsaturated hydrocarbon group. 5. The thermosetting polymer according to claim 1, wherein the functional group causing the crosslinking reaction is selected from an allyl group, a propargyl group and a functional group represented by the formula (3). Ether resin. (In the formula, T ¹ is selected from an alkenyl group having 2 to 10 carbon atoms and an alkynyl group having 2 to 10 carbon atoms. T ² is an alkyl group having 1 to 10 carbon atoms and an optionally substituted arylene group. And n is an integer of 1 or more and 3 or less.
When T ¹ is plural, they may be the same or different from each other;
When there are a plurality of T ^{2 s} , they may be the same or different. ) 6. The thermosetting polyether resin has a weight average molecular weight in terms of polystyrene by GPC of 1,000 or more and 600 or more.
The thermosetting polyether resin according to any one of claims 1 to 5, which is not more than 00. 7. A step of polycondensing a dihalogenated compound and a bisphenol compound, metallizing the resulting polyether resin, and subsequently performing a substitution reaction using a halogenated compound having a functional group capable of causing a crosslinking reaction in the molecule. The method for producing a thermosetting polyether resin according to any one of claims 1 to 6, wherein the method comprises: 8. A coating liquid for forming an insulating film, comprising the thermosetting polyether resin according to claim 1.