JP2001226599A - Resin composition for forming multi-layered wiring with void and multi-layered wiring with void using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition capable of utilizing a conventional multi-layered wiring process and a unit used therefor in forming a multi-layered wiring having the least static capacity between the wires. SOLUTION: This resin composition for multi-layered wiring with void contains, as essential components, a heat vaporizable component (A) and a heat resistant resin or its precursor having a glass transition temperature higher than the heat vaporization temperature of a polymer of the component (A), and a multi-layered wiring with void is provided by using the same.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for forming a hollow multilayer wiring, and more particularly, to a method for forming a hollow multilayer wiring in a semiconductor device for electric / electronic equipment with high definition and a high void ratio. And a hollow multilayer wiring using the same.

[0002]

2. Description of the Related Art Among the characteristics required for materials for electric and electronic devices and semiconductor devices, the electric characteristics of insulating materials are the most important characteristics. In particular, in recent years, with miniaturization of circuits and speeding up of signals, an insulating material having a low dielectric constant has been required.
For example, conventionally used silicon dioxide has a high relative dielectric constant of 3.9, and a material having a relative dielectric constant of 3.0 or less is being developed by using a heat-resistant resin represented by a polyimide resin.

Attempts have also been made to reduce the relative dielectric constant to 2.0 or less by making the insulating material porous.
The lowest dielectric constant is achieved by replacing the insulating material with a vacuum. In this case, the relative dielectric constant becomes 1.0. In reality, a gas such as air is present by hollowing out an insulating material portion, but a hollowed-out multilayer wiring that obtains substantially the same relative dielectric constant has been proposed.

As a method of forming the hollow multilayer wiring, a method of setting up a conductor pillar on the wiring and passing an upper wiring thereon has been considered, but using a conventional multilayer wiring process and apparatus. In addition, it is easy in terms of technical development to use an insulating material halfway and remove it in a subsequent step while leaving only the wiring.

However, since the insulating material used in the conventional multilayer wiring forming process is required to be stable to heat, chemicals, plasma, and the like received during the process, it is difficult to remove the insulating material after forming the multilayer wiring. was difficult.

[0006]

SUMMARY OF THE INVENTION The present invention provides a hollow multi-layer wiring capable of obtaining the lowest dielectric constant as an insulator between wirings.
While using conventional multilayer wiring processes and equipment,
It is an object of the present invention to provide a resin composition suitable for using a resin material halfway, and removing the resin material while leaving only the wiring in a subsequent step, and a hollow multilayer wiring obtained by the method. .

[0007]

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

That is, 1. A heat-vaporizable component (A) and a heat-resistant resin or a precursor (B) having a glass transition temperature of the resin higher than the heat vaporization temperature of the component (A) and removable by chemical means. A resin composition for forming a hollow multilayer wiring as an essential component,

[0009] 2. The resin composition according to the above 1, wherein the thermally vaporizable component (A) is an oligomer or a polymer having a repeating unit selected from the group consisting of propylene oxide, ethylene oxide, methyl methacrylate, styrene and carbonate.

[0010] 3. Component (A) having a molecular weight of 1
The resin composition according to the above 1, which is an oligomer or a polymer having a molecular weight of from 00 to 10,000.

4. 2. The organic insulating film material according to the above 1, wherein the thermally vaporizable component (A) accounts for 25 to 85% of the volume of the resin composition at room temperature,

5. Heat resistant resin or its precursor (B)
Is a resin composition according to the above 1, which is a polyimide resin or a polyimide precursor,

6. Heat resistant resin or its precursor (B)
Is a polybenzoxazole resin or a polybenzoxazole precursor,

7. Heat resistant resin or its precursor (B)
Wherein the resin composition according to the above 1, which is composed of only elements selected from carbon, hydrogen, oxygen, nitrogen, and sulfur;

[8] 8. The glass transition of a resin obtained by using the resin composition for forming a hollow multilayer wiring according to any one of the above items 1 to 7 at a temperature higher than the thermal vaporization temperature of the component (A) and closing the heat-resistant resin or its precursor. By creating a porous heat-resistant resin structure by heat treatment at a temperature below the temperature, embedding or laminating a wiring made of metal in such a structure, by removing such porous heat-resistant resin structure by chemical means. Cavity multilayer wiring characterized by being obtained,

9. 9. The hollow multilayer arrangement according to the above 8, wherein the chemical means is dissolution by a solvent.

10. 9. The hollow multilayer wiring according to the above item 8, wherein the chemical means is decomposition by a gas activated by plasma under reduced pressure.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The resin composition for forming a hollow multilayer wiring according to the present invention comprises a thermally vaporizable component (A), a resin whose glass transition temperature is higher than the thermal vaporization temperature of the component (A), and It comprises a heat-resistant resin or its precursor (B) which can be removed by means as an essential component. Although it is possible to use a solvent as a component other than the component (A) and the heat-resistant resin or its precursor (B), the component (A) is a liquid that dissolves the heat-resistant resin or its precursor (B). In this case, the component (A) can also serve as a solvent. Further, a small amount of a surfactant, a surface treatment agent, or the like can be added to improve the adhesion to other members for forming a multilayer wiring or to improve the processability.

The resin composition for forming a hollow multilayer wiring of the present invention can be removed in a later step by applying it on a substrate or the like and heating and forming a film, or impregnating a glass cloth or the like and heating it. It can be a multilayer wiring component. In this heating step, the component (A) is thermally vaporized, and the heat-resistant resin forms a porous structure while maintaining a void corresponding to the volume occupied by the component (A). When component (B) is a precursor, it is converted into a heat-resistant resin in this heating step or in a curing step performed prior to thermal vaporization of component (A), and a high glass transition temperature is developed. In order to form the structure while the heat-resistant resin retains the voids, it is important to increase the heating temperature to a temperature higher than the thermal vaporization temperature of the component (A) and a temperature equal to or lower than the glass transition temperature of the heat-resistant resin. .

Examples of the thermally vaporizable component (A) used in the present invention include propylene oxide, ethylene oxide, methyl methacrylate, styrene, carbonate,
Vinyl acetate, methyl methacrylate, divinyl benzene, hydroxy methacrylate, methacrylamide, N,
N-dimethylacrylamide, dimethylaminoethyl methacrylate, glycerol dimethacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, vinyl cinnamate, N-vinyl pyrrolidone,
An oligomer or polymer having a repeating unit selected from phenylglycidyl ether, bisphenol F type epoxy, etc., but is not limited thereto. It is also possible to add a polymerization initiator. Desirable to completely vaporize by heat, propylene oxide, ethylene oxide, methyl methacrylate,
Oligomers or polymers having a repeating unit selected from the group consisting of styrene and carbonate are particularly preferred.

If the size of the voids in the porous structure formed after the heating step is larger than the fineness of the wiring embedded or laminated in the porous structure to be subsequently performed, There is a problem that the definition of the image is lost.
According to the road map of the Semiconductor Industry Association of America (SIA), the relative dielectric constant of a multilayer wiring of a semiconductor is 1.5 from the generation where the design rule is 0.1 μm or less.
They want to be: Design rule is 0.1
The width and interval of the multilayer wiring in the generation of μm are 0.1 to 5
μm, and the size of the voids of the porous structure according to the present invention for corresponding to that generation must be sufficiently smaller than 0.1 μm in diameter. The molecular weight of the thermally vaporizable component (A) that gives such a void size is 1
It needs to be an oligomer or polymer having a molecular weight of from 00 to 10,000.

If the ratio of the voids in the porous structure formed after the heating step is too large, the shape of the structure in the subsequent process of wiring embedded or laminated in the porous structure is performed. Insufficient strength to maintain the resin composition and destruction and peeling of the multilayer structure occur. Therefore, it is desirable that the content of the thermally vaporizable component (A) is 85% or less in the volume occupied at room temperature of the resin composition. It is preferable that the voids of the porous structure formed after the heating step are continuous in the removal of the porous structure performed after the formation of the multilayer wiring. As conditions for obtaining, the thermally vaporizable component (A)
The volume of the resin composition at room temperature is desirably 25% or more.

Examples of the heat-resistant resin or its precursor (B) which have a glass transition temperature higher than the thermal vaporization temperature of the component (A) and which can be removed by chemical means are given below. , Polyimide, polyamic acid, polyamic acid ester, polyisoimide, polyamideimide, polyamide, bismaleimide, polybenzoxazole, polyhydroxyamide, polybenzothiazole,
Examples include, but are not limited to, polyarylene ether, norbornene resin, and cyclopentadiene resin. It is also possible to introduce a crosslinkable functional group such as an acetylene group into the terminal or side chain of these polymers, and form a crosslinked structure by heating. Among them, polyimide resins and polyimide precursors such as polyamic acid, polyamic acid ester and polyisoimide, and polybenzoxazole resins and polybenzoxazole precursors such as polyhydroxyamide are preferable because of high heat resistance.

The resin used in the present invention has a glass transition temperature higher than the thermal vaporization temperature of the component (A) and can be removed by chemical means. Needless to say, it is a material that does not corrode the members used in the forming process, but in particular, a plasma atmosphere caused by resist ashing in the process of forming the multilayer wiring and a porous structure performed after the formation of the multilayer wiring. It is also required that a gas component generated in the case of using decomposition activated by plasma under reduced pressure in plasma removal or the like does not affect members specified in a process of forming a multilayer wiring. For that purpose, the heat-resistant resin or its precursor (B) is desirably composed of only an element selected from carbon, hydrogen, oxygen, nitrogen, and sulfur. The gas components composed of these elements do not substantially affect wiring materials such as aluminum and copper, glass, ceramics, silicon wafers, thermal oxide films, nitride films, and the like. Undesirable elements include halogen group elements, especially fluorine. A gas component composed of fluorine has a property of eroding a silicon-based material. In addition, it is not preferable to include a metal such as aluminum or copper, or a semiconductor element such as silicon, since the selectivity to the multilayer wiring forming member is lost in removing the porous structure after the formation of the multilayer wiring.

When a solvent is used as a component of the resin composition for forming a hollow multilayer wiring of the present invention, preferable examples include N, N-dimethylacetamide, N-methyl-2-pyrrolidone, tetrahydrofuran, propylene glycol monomethyl. Examples thereof include, but are not limited to, ether, propylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether, and γ-butyrolactone. Further, two or more of these may be used at the same time.

As an example of the method for producing a hollow multilayer wiring according to the present invention, the resin composition for forming a hollow multilayer wiring according to the present invention is used.
After dissolving in the above solvent to form a varnish, it is applied to a silicon wafer or the like on which a multilayer wiring is to be formed. Specific coating methods include spin coating using a spinner, spray coating using a spray coater, dipping, printing, roll coating, and the like. By forming a coating film in this manner and performing heat treatment at a temperature higher than the thermal vaporization temperature of the component (A) and at a temperature equal to or lower than the glass transition temperature of the resin in which the heat-resistant resin or its precursor is closed, a porous heat-resistant resin is obtained. After forming a conductive resin structure and forming a mask with an appropriate photo process,
A connection hole or a wiring groove is formed in the heat-resistant resin structure by the IE method or the like, copper is buried by plating or the like to form a wiring, and a porous heat-resistant resin structure is formed thereon again, and this operation is repeated. In this manner, a multilayer wiring is formed, and then the porous heat-resistant resin structure is removed by chemical means, whereby a hollow multilayer wiring can be obtained.

A feature of the present invention is that the heat-resistant resin structure to be removed after the formation of the multilayer wiring structure has a substantially open-cell structure, and the amount of the heat-resistant resin structure to be removed due to the high porosity. In that it can be removed in a short time. Until it is removed, it serves as a support for forming a multilayer wiring structure by a conventional process and apparatus.

The resin composition for forming a hollow multilayer wiring according to the present invention is heat-treated at a temperature higher than the thermal vaporization temperature of the component (A) and at a temperature not higher than the glass transition temperature of the resin in which the heat-resistant resin or its precursor is closed. By creating a porous heat-resistant resin structure and embedding or laminating a wiring made of metal in such a structure, as a chemical means for removing the porous heat-resistant resin structure, dissolution by a solvent or Decomposition by a gas activated by plasma under reduced pressure is preferred. Alternatively, heating to a high temperature at which the heat-resistant resin is vaporized may be considered, but it is not energetically reasonable to decompose the heat-resistant resin by heat. It is also conceivable to decompose the heat-resistant resin after decomposing it so that it decomposes at a low temperature, but this is not efficient because of additional steps.

As the solvent dissolution, an organic solvent that dissolves a heat-resistant resin can be used. If glass or silicon is the interface with the heat-resistant resin, sulfuric acid or the like can be used.

When decomposed by a gas activated by plasma under reduced pressure, the rate at which oxygen plasma decomposes the heat-resistant resin is high, and the difference from the rate at which metal and inorganic materials are decomposed is large. . When oxygen plasma degrades a metal or inorganic material, nitrogen plasma or mixed plasma of oxygen and nitrogen can be used.

[0031]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to the contents of the examples.

Example 1 (1) Synthesis of Polyimide Resin In a separable flask equipped with a stirrer, a nitrogen inlet tube and a raw material inlet, 2,2-bis (4- (4,4'-aminophenoxy)) was prepared. 4.10 g of phenyl) propane (0.01 m
ol) and 5.52 g of 4,4'-diaminobiphenyl
(0.03 mol) is dissolved in 200 g of dried N-methyl-2-pyrrolidone (hereinafter abbreviated as NMP). The solution was cooled to 10 ° C. under dry nitrogen, and biphenyltetracarboxylic dianhydride 2.94 (0.01 mol) and isopropylidene-3,3′-bis (phthalic anhydride) 10.
08 g (0.03 mol) was charged. Five hours after the introduction, the temperature was returned to room temperature, and the mixture was stirred at room temperature for 2 hours to obtain a solution of polyamic acid as a polyimide precursor. After adding 50 g of pyridine to this polyamic acid solution, 0.05% of acetic anhydride was added.
mol was added dropwise, and an imidization reaction was carried out for 7 hours while maintaining the temperature of the system at 70 ° C. This solution was dropped into 20 times the volume of water to collect the precipitate, and vacuum-dried at 60 ° C. for 72 hours to obtain 19.15 g of a polyimide resin solid as a heat-resistant resin.

(2) Measurement of Glass Transition Temperature of Heat-Resistant Resin 5.0 g of the polyimide resin synthesized as described above was added to NMP1
After dissolving in 5.0 g and applying it on a glass substrate that has been subjected to a mold release treatment, it is kept in an oven at 120 ° C. for 30 minutes and then 230 ° C.
After holding the film for 90 minutes, the film was peeled off from the substrate, and further heated at 400 ° C. for 90 minutes to obtain a polyimide resin film. The glass transition temperature of the polyimide resin measured by a dynamic viscoelasticity measuring apparatus was 350 ° C.

(3) Measurement of Thermal Vaporization Temperature of Thermally Vaporizable Component A commercially available propylene oxide-ethylene oxide block copolymer having an average molecular weight of 8,000 (Daiichi Kogyo Seiyaku Co., Ltd.)
And Epan 485) were measured in air by thermogravimetric analysis. The weight residue after heating at 250 ° C. for 2 hours was 1
% Or less.

(4) Preparation of Resin Composition for Forming Hollow Multilayer Wiring and Production of Hollow Multilayer Wiring 10.0 g of the polyimide resin synthesized as described above was subjected to NMP.
After dissolving in 50.0 g, a propylene oxide-ethylene oxide block copolymer having an average molecular weight of 8,000.
0 g (about 40% by volume of components other than NMP) was added and stirred to obtain a resin composition for forming a hollow multilayer wiring. On a silicon wafer on which a thermal oxide film with a thickness of 100 nm is formed,
After spin-coating this resin composition for forming a hollow multilayer wiring, it was heated at 300 ° C. for 2 hours in an oven in an air atmosphere. As a result, a film made of a porous heat-resistant resin having a thickness of 0.5 μm was obtained. A thickness of 40 on this porous heat-resistant resin film
A silicon oxide film having a thickness of 5 nm was formed by a CVD method, a pattern having a width of 1 μm, an interval of 1 μm, and a length of 5 mm was formed by a photolithography method, and etched by an RIE method using CF ₄ gas to obtain a hard mask having the same pattern. . By using this hard mask and etching by a RIE method using nitrogen gas, wiring grooves of the same pattern were formed in the film of the porous heat-resistant resin. A copper film having a thickness of 1 μm was formed by sputtering, and the surface of the porous heat-resistant resin was polished by CMP. The same operation was repeated on the polished surface, and a second copper wiring was overlapped so as to be orthogonal to the copper wiring. The silicon wafer thus formed on the surface of which the copper wiring of the two-layer structure was formed was placed in an oxygen plasma incinerator and treated at 200 W for 5 minutes. As a result, the porous heat-resistant resin was completely removed and combined in a lattice. Copper wiring appeared. The cross section was observed by SEM, and the lower portion of the upper copper wiring was also hollowed out without any residue.

Example 2 (1) Synthesis of Polyimide Precursor The 2,2-bis (4- (4,4'-aminophenoxy)) used in the synthesis of the polyimide precursor in the synthesis of the polyimide resin of Example 1 was used. 4.10 g of phenyl) propane (0.
01 mol) and 4,4'-diaminobiphenyl 5.52
g (0.03 mol) to 8.04 g (0.04 mol) of 4,4′-diaminodiphenyl ether and 2.94 g (0.01 mol) of biphenyltetracarboxylic dianhydride
l) and 10.08 g (0.03 mol) of isopropylidene-3,3'-bis (phthalic anhydride) were replaced by 8.72 g (0.04 mol) of pyromellitic dianhydride. In the same manner as in 1, a solution of a polyamic acid as a polyimide precursor was obtained. This solution was dropped into 20 times the volume of water, and the precipitate was collected and vacuum-dried at 25 ° C. for 72 hours to obtain 14.45 g of a solid of polyamic acid, which is a precursor of polyimide as a heat-resistant resin. .

(2) Measurement of Glass Transition Temperature of Heat-Resistant Resin 5.0 g of the polyamic acid synthesized as described above was added to NMP2
After dissolving it in 0.0 g and applying it on a release-treated glass substrate, it was kept in an oven at 120 ° C. for 30 minutes, then at 250 ° C.
After holding the film for 90 minutes, the film was peeled off from the substrate, and further heated at 450 ° C. for 90 minutes to obtain a polyimide resin film as a heat-resistant resin. The glass transition temperature of this polyimide resin was 419 ° C. as measured by a dynamic viscoelasticity measuring device.

(3) Measurement of Thermal Decomposition Temperature of Thermally Vaporizable Component 10 g of commercially available polypropylene oxide having an average molecular weight of 4000 (Uniol D-4000, manufactured by NOF Corporation)
Was measured by thermogravimetric analysis under a nitrogen atmosphere. As a result, the residual weight after 3 hours at 350 ° C. was 1% or less.

(4) Preparation of Resin Composition for Forming Cavity Multilayer Wiring and Production of Cavity Multilayer Wiring 10.0 g of the polyamic acid synthesized as described above was added to NMP5.
After dissolving in 0.0 g, 20.0 g of polypropylene oxide having an average molecular weight of 4000 (about 75% by volume in the components other than NMP) was added and stirred to obtain a resin composition for forming a hollow multilayer wiring. The resin composition for forming a hollow multilayer wiring was spin-coated on a silicon wafer on which a thermal oxide film having a thickness of 100 nm was formed, and then heated at 350 ° C. for 3 hours in an oven in a nitrogen atmosphere. As a result, the thickness 0.5
A coating made of a porous heat-resistant resin having a thickness of μm was obtained. Thereafter, when a hollow multilayer wiring was formed in the same manner as in Example 1, a grid-like copper wiring was obtained in the same manner. Observe the cross section by SEM,
The lower part of the upper copper wiring was also hollow without any residue.

Example 3 (1) Synthesis of polybenzoxazole resin 28.4 g (0.1 mol) of 4,4'-isopropylidenediphenyl-1,1'-dicarboxylic acid, 45 ml of thionyl chloride and 0 ml of dry dimethylformamide 0.5 ml was placed in a reaction vessel and reacted at 60 ° C. for 2 hours. After completion of the reaction, excess thionyl chloride was distilled off by heating and reduced pressure. The precipitate was recrystallized using hexane to obtain 4,4 ′
28.9 g of -isopropylidenediphenyl-1,1'-dicarboxylic acid chloride were obtained. Stirrer, nitrogen inlet tube,
4. In a separable flask equipped with a dropping funnel, 2,2-bis (3-amino-4-hydroxyphenyl) propane.
16 g (0.02 mol) was dissolved in 100 g of dried dimethylacetamide, and 3.96 g (0.0%) of pyridine was dissolved.
5 mol) was added thereto, and under dry nitrogen introduction, at -15 ° C, 50 g of dimethylacetamide was added to 4,5
A solution of 6.42 g (0.02 mol) of 4'-isopropylidenediphenyl-1,1'-dicarboxylic acid chloride was added dropwise over 30 minutes. After completion of the dropwise addition, the mixture was returned to room temperature and stirred at room temperature for 5 hours. Then, the reaction solution was added to water 1
The resulting precipitate was collected and dried under vacuum at 40 ° C. for 48 hours to obtain 9.41 g of a polyhydroxyamide as a polybenzoxazole precursor. After adding 50 g of pyridine to a solution of this polyhydroxyamide dissolved in 200 g of NMP, 0.03 mol of acetic anhydride was added dropwise, and the oxazolation reaction was carried out for 7 hours while maintaining the system temperature at 70 ° C. This solution was dropped into a 20-fold amount of water to collect a precipitate, followed by vacuum drying at 60 ° C. for 72 hours to obtain 8.30 g of a polybenzoxazole resin as a heat-resistant resin.

(2) Measurement of glass transition temperature of heat-resistant resin Polybenzoxazole resin 5.0 synthesized as described above
g, NMP 8.0 g and tetrahydrofuran 12.0 g
And then applied on a release-treated glass substrate, kept in an oven at 120 ° C. for 30 minutes, and then kept at 240 ° C. for 90 minutes to form a film. It heated at 90 degreeC for 90 minutes, and set it as the film of the polybenzoxazole resin which is a heat resistant resin. The glass transition temperature of this polybenzoxazole resin was 390 ° C. when measured with a dynamic viscoelasticity measuring device.

(3) Measurement of heat vaporization temperature of heat vaporizable component Ethylene glycol dimethacrylate (Nippon Oil & Fats Co., Ltd.)
Of azobisisobutyronitrile was added to 10 g of Blenmer PDE-50 (manufactured by Co., Ltd.).
Polymerization was carried out at ° C. The molecular weight of the obtained polymer is determined by GPC
Was 500 in terms of polystyrene, and the pyrolysis temperature under a nitrogen atmosphere was measured by thermogravimetric analysis.
The residual weight at 50 ° C. for 3 hours was 1% or less.

(4) Preparation of Resin Composition for Forming Hollow Multilayer Wiring and Production of Hollow Multilayer Wiring Polybenzoxazole resin 5.0 synthesized as described above.
g, NMP 8.0 g and tetrahydrofuran 12.0 g
, And 4.0 g of ethylene glycol dimethacrylate polymer having a molecular weight of 500 (approximately 40% by volume in the components excluding the solvent) is added and stirred to obtain a resin composition for forming a hollow multilayer wiring. Was. The resin composition for forming a hollow multilayer wiring was spin-coated on a silicon wafer on which a thermal oxide film having a thickness of 100 nm was formed, and then heated at 350 ° C. for 3 hours in an oven in a nitrogen atmosphere. as a result,
A film made of a porous heat-resistant resin having a thickness of 0.5 μm was obtained.
Thereafter, a copper wiring having a two-layer structure is formed in the same manner as in Example 1.
The silicon wafer was immersed in an ultrasonic cleaning tank at 80 ° C. for 10 minutes containing a mixed solvent consisting of NMP and tetrahydrofuran in a weight ratio of 2: 3, washed with pure water and dried. Completely removed, a grid of copper interconnects appeared. The cross section was observed by SEM, and the lower portion of the upper copper wiring was also hollowed out without any residue.

Example 4 (1) Synthesis of polyhydroxyamide 24.2 g of biphenyl-4,4'-dicarboxylic acid (0.
1 mol), 45 ml of thionyl chloride and 0.5 ml of dry dimethylformamide were placed in a reaction vessel and reacted at 60 ° C. for 2 hours. After completion of the reaction, excess thionyl chloride was distilled off by heating and reduced pressure. The precipitate was recrystallized using hexane to obtain 25.1 g of biphenyl-4,4'-dicarboxylic acid chloride. 5.16 g of 2,2-bis (3-amino-4-hydroxyphenyl) propane in a separable flask equipped with a stirrer, a nitrogen inlet tube, and a dropping funnel.
(0.02 mol) was dissolved in 100 g of dried dimethylacetamide, and 3.96 g (0.05 mol) of pyridine was dissolved.
After addition of l), the biphenyl-synthesized as above was added to 50 g of dimethylacetamide at -15 ° C under dry nitrogen introduction.
5.58 g of 4,4'-dicarboxylic acid chloride (0.02 g)
mol) was added dropwise over 30 minutes. After completion of the dropwise addition, the mixture was returned to room temperature and stirred at room temperature for 5 hours. Thereafter, the reaction solution was dropped into 1000 ml of water, and the precipitate was collected and vacuum-dried at 40 ° C. for 48 hours to obtain 8.63 g of a solid material of polyhydroxyamide, which is a precursor of polybenzoxazole, which is a heat-resistant resin. I got

(2) Measurement of Glass Transition Temperature of Heat-Resistant Resin
After dissolving in 20.0 g of MP and applying it on a glass substrate subjected to a mold release treatment, it was kept in an oven at 120 ° C. for 30 minutes, and then 24
A film was formed by holding the film at 0 ° C. for 90 minutes, and after peeling the film from the substrate, the film was further heated at 400 ° C. for 90 minutes to obtain a polybenzoxazole film as a heat-resistant resin. The glass transition temperature of this polybenzoxazole was measured using a dynamic viscoelasticity measurement device, and was 440 ° C.

(3) Measurement of Thermal Vaporization Temperature of Thermally Vaporizable Component To 10 g of glycerol dimethacrylate (manufactured by NOF CORPORATION, Blenmer GMR), 0.01 g of azobisisobutyronitrile was added, and the mixture was added under a nitrogen atmosphere. Polymerization was carried out at ° C. The molecular weight of the obtained polymer was 1500 in terms of polystyrene by GPC, and the pyrolysis temperature under a nitrogen atmosphere was measured by thermogravimetric analysis. The weight residue at 400 ° C. for 2 hours was 1% or less. Met.

(4) Preparation of Resin Composition for Forming Cavity Multilayer Wiring and Production of Cavity Multilayer Wiring 10.0 g of polyhydroxyamide synthesized as above was dissolved in 50.0 g of NMP, and then a glycerol dimethacrylate polymer 8 having a molecular weight of 1500 was prepared. 0.0 g (about 45% by volume of components other than NMP) was added and stirred to obtain a resin composition for forming a hollow multilayer wiring. The resin composition for forming a hollow multilayer wiring was spin-coated on a silicon wafer on which a thermal oxide film having a thickness of 100 nm was formed, and then heated at 400 ° C. for 2 hours in an oven in a nitrogen atmosphere. As a result, a film made of a porous heat-resistant resin having a thickness of 0.5 μm was obtained. Thereafter, when a hollow multilayer wiring was formed in the same manner as in Example 1, a grid-like copper wiring was obtained in the same manner. The cross section was observed by SEM, and the lower portion of the upper copper wiring was also hollowed out without any residue.

Comparative Example 1 A hollow multilayer wiring was produced in the same manner as in Example 4 except that 8.0 g of the glycerol dimethacrylate polymer used in the preparation of the resin composition for forming a hollow multilayer wiring of Example 4 was not added. Preparation of a resin composition for formation and production of a hollow multilayer wiring were performed. It took 30 minutes to remove the heat-resistant resin using an oxygen plasma incinerator, and the residue of the heat-resistant resin adhered to the lower part of the upper copper wiring of the obtained hollow multilayer wiring.

Comparative Example 2 A polypropylene glycol polyethylene glycol copolymer having a molecular weight of 13,000 (Daiichi Kogyo Seiyaku Co., Ltd.) was used instead of 8.0 g of glycerol dimethacrylate used in the preparation of the resin composition for forming a hollow multilayer wiring of Example 4. Except for the addition of 8.0 g of Epan 785) manufactured by K.K., adjustment of the resin composition for forming the hollow multilayer wiring and production of the hollow multilayer wiring were performed in the same manner as in Example 4. The porous heat-resistant resin film obtained after the thermal vaporization had voids having a diameter of 0.1 μm or more, and the pattern of the copper wiring was significantly damaged.

Comparative Example 3 In the preparation of the resin composition for forming a hollow multilayer wiring of Example 4, the polybenzoxazole of Example 3 was used instead of polyhydroxyamide, which is a precursor of polybenzoxazole, which is a heat-resistant resin. Preparation of a hollow multilayer wiring and production of a hollow multilayer wiring were performed in the same manner as in Example 4 except that polybenzoxazole having a glass transition temperature of 390 ° C. obtained by the synthesis of was used. After heat vaporization, a porous heat-resistant resin film was not obtained, and a film made of only the heat-resistant resin and having a thickness of 0.3 μm was obtained.

In Examples 1 to 4, a hollow multilayer wiring was formed by using a resin composition for forming a hollow multilayer wiring.

In Comparative Example 1, a porous heat-resistant resin film was not formed because it did not have a heat-vaporizable component, and as a result, removal after forming the multilayer wiring structure could not be performed well.

In Comparative Example 2, the molecular weight of the heat-vaporized component added was large, the size of the voids in the porous heat-resistant resin film after heat vaporization was large, and a 1 μm-wide copper wiring could not be formed. .

In Comparative Example 3, a porous heat-resistant resin film could not be formed because the glass transition temperature of the heat-resistant resin was lower than the thermal vaporization temperature of the component (A). It was difficult to remove the heat-resistant resin.

[0055]

According to the hollow multilayer wiring of the present invention, the dielectric constant between wirings is reduced to a level close to a theoretical limit of 1, and various characteristics where this characteristic is required, for example, for semiconductors Is useful as a multilayer wiring, a hybrid integrated circuit or a multilayer wiring circuit, and the resin composition for forming a hollow multilayer wiring of the present invention can form a hollow multilayer wiring using a conventional multilayer wiring forming process or apparatus. It is a useful resin composition that can be used.

Continued on the front page F-term (reference) 4J002 BC01W BC03W BF02W BG06W BG07W BG13W BH02X BJ00W CD05W CD19W CE00X CG00W CH02W CL00X CM04X CN06X EA046 EH006 EH076 EJ036 EL026 EP016 EU026 FD20W19A08 QAQ2A UA111 UA121 UA122 UA131 UA132 UA561 UB011 UB121 VA011 XA13 XA19 ZB47 ZB48 5F033 HH11 QQ09 QQ12 QQ48 RR30 SS21 XX24

Claims (10)

[Claims] 1. A heat-vaporizable component (A) and a heat-resistant resin or a precursor thereof which have a glass transition temperature higher than that of the component (A) and which can be removed by chemical means. And (B) as essential components. 2. The hollow multilayer wiring according to claim 1, wherein the heat-vaporizable component (A) is an oligomer or a polymer having a repeating unit selected from the group consisting of propylene oxide, ethylene oxide, methyl methacrylate, styrene and carbonate. Forming resin composition. 3. The heat-vaporizable component (A) having a molecular weight of 10
The resin composition according to claim 1, which is an oligomer or a polymer having a molecular weight of 0 to 10,000. 4. The resin composition according to claim 1, wherein the thermally vaporizable component (A) accounts for 25 to 85% of the volume of the resin composition at room temperature. 5. The heat-resistant resin or a precursor (B) thereof,
2. A polyimide resin or a polyimide precursor.
The resin composition for forming a hollow multilayer wiring according to the above. 6. The heat-resistant resin or a precursor (B) thereof,
The resin composition according to claim 1, which is a polybenzoxazole resin or a polybenzoxazole precursor. 7. The heat-resistant resin or a precursor (B) thereof,
The resin composition for forming a hollow multilayer wiring according to claim 1, wherein the resin composition is composed of only an element selected from carbon, hydrogen, oxygen, nitrogen, and sulfur. 8. A resin composition for forming a hollow multilayer wiring according to any one of claims 1 to 7, wherein a temperature higher than the thermal vaporization temperature of the component (A) and a heat-resistant resin or a precursor thereof are closed. A porous heat-resistant resin structure is created by heat-treating the resin at a temperature lower than the glass transition temperature of the resin, and after embedding or laminating wiring made of metal in the structure, the porous heat-resistant resin is formed by chemical means. A hollow multilayer wiring obtained by removing a structure. 9. The hollow multilayer wiring according to claim 8, wherein the chemical means is dissolution by a solvent. 10. The hollow multilayer wiring according to claim 8, wherein the chemical means is decomposition by a gas activated by plasma under reduced pressure.