KR20040095089A - low dielectric films of nanoporous norborenen copolymer and manufacturing methods therefor - Google Patents

Abstract

PURPOSE: Provided is a method for manufacturing a nanoporous thin film based on a polynorbornene copolymer having reinforced adhesive property and low dielectric constant suitable for use in advanced multi-chip packages and optical wiring materials. CONSTITUTION: The method for manufacturing a nanoporous thin film comprises the steps of: copolymerizing at least one norbornene monomer with a thermally degradable monomer having a thermal decomposition temperature lower than the glass transition temperature of polynorbornene; coating the copolymer to form a thin film; heat treating the thin film at a temperature lower than the glass transition temperature of polynorbornene and equal to or higher than the thermal decomposition temperature to decompose the thermally degradable monomer, thereby forming nanopores in the thin film.

Description

Low dielectric films of nanoporous norborenen copolymer and manufacturing methods therefor}

The present invention relates to a method for forming nanopores using a polynorbornene-based copolymer containing a nanopore generating material.

Recently, with the development of information and communication, a fast processing speed of massive data is required, and a switch from a single chip type to a parallel processing method connecting a plurality of chips is required. This requires the development of low dielectric materials with excellent properties for wiring in multichip packages connecting multiple microchips. In order to reduce the capacitance and signal delay that influence the performance of the electronic system, the development of a filler having a lower dielectric constant is required. In addition, low dielectric materials used in the interlayer dielectric materials of liquid crystal display thin film transistors are a key material that can lead to weight reduction of products by increasing the speed of devices and reducing energy consumption beyond the existing simple functions of protecting integrated circuits. According to the US semiconductor industry, low-k materials for multi-chip packages that need to be developed before 2005 should have properties such as dielectric constant of 2.0 or less, 300 ° C or higher, thermal stability and low moisture absorption. In addition, demand for materials required for the development of high-speed electronic systems through optical wiring as well as electrical wiring is expected after 2005. For this, organic thin film materials should have appropriate refractive index, high light transparency and low light loss.

Silicon oxide film (SiO ₂ ) has been used as a conventional semiconductor package and interlayer insulating material, but the dielectric constant is high as about 4.0.

Accordingly, various attempts have been made to develop low-k materials for next-generation packages, and polyimide, benzocyclobutene, polynorbornene, and the like are examples.

The polyimide has high dielectric constants of 2.9 to 3.5, high hygroscopicity and high electrical and optical anisotropy due to polymer structural problems. The benzocyclobutene developed by Dow has a high dielectric constant of about 2.7 and a thin film manufacturing process. There is a problem that the complexity and the adhesion to the metal is poor.

Polynorbornene has excellent properties such as thermal stability, low hygroscopicity and electrical and optical isotropy, so its application is expected as a low dielectric material for next generation packages, but this also has a problem of poor interfacial adhesion in thin film manufacturing. . In the case of polynorbornene developed by BF Goodrich, which has recently been in the spotlight, the silicone compound containing an alkoxy group as a polar group was introduced into the norbornene to overcome adhesion, but the dielectric constant increased due to the introduction of the polar group in the polymer (about 2.7). There was this.

SUMMARY OF THE INVENTION The present invention has been made to overcome the above disadvantages, and in order to enable the polynorbornene copolymer to be used as an optical wiring material for next-generation multichip packages and semiconductors, an improved polynovo having improved dielectric properties and low dielectric constant It is an object to provide a nene copolymer.

In addition, it is an object of the present invention to provide a method which can further simplify the manufacturing process of the above-described improved polynorbornene copolymer.

1 is a ¹ H-NMR spectrum of the polynorbornene copolymer according to an embodiment of the present invention.

2 is a thermal characteristic of the polynorbornene copolymer and the content of the comonomer according to an embodiment of the present invention.

3 is a ¹ H-NMR spectrum of the polynorbornene block copolymer according to an embodiment of the present invention.

4 is a structural analysis by incineration scattering experiment of the polynorbornene block copolymer according to an embodiment of the present invention

5 is a cross-sectional photograph of a porous polymer thin film prepared from a polynorbornene copolymer

In order to achieve the above object, the present invention provides a method for introducing a nanopore former into a polynorbornene copolymer and a polynorbornene copolymer containing a nanopore former.

In addition, the present invention is to convert the hydroxy group to another functional group by a chemical method so that the hydroxy group does not deactivate the catalyst during polymerization of the polynorbornene copolymer using the norbornene-based monomer, and after the synthesis of the copolymer is reduced to a hydroxy group again in the polynorbornene copolymer Provided is a method of introducing nanopore formers.

In addition, the present invention further provides a copolymer consisting of a norbornene-based monomer and a norbornene in which the nano-pore-forming agent is introduced after the nano-pore-forming agent is introduced into the norbornene monomer by a chemical reaction, and a method of preparing the same.

In addition, the present invention further provides a low dielectric insulating material and an antireflection film material for semiconductor exposure process, characterized in that the copolymer consisting of norbornene, norbornene-based monomers and nano-pore forming agent.

In addition, the present invention further provides a low dielectric insulating material and a semiconductor exposure process anti-reflection film material, characterized in that the ratio of the nano-pore forming agent in the copolymer is 0-70 mol%.

In addition, the present invention further provides a method of preparing a material containing nanopores by decomposing the nanopore formers with or without curing the copolymer containing the nanopore formers.

In addition, the present invention by mixing the nano-pore forming agent with a solvent to rotate the coating on a substrate to form a thin film of a predetermined thickness, and heat-treat the thin film, the temperature of the nano-pore forming agent is gradually reduced in nitrogen or vacuum A method of manufacturing a low dielectric insulating film and an antireflection film for a semiconductor exposure process and a low dielectric insulating film and a semiconductor produced by the method, characterized by rising above and decomposing the nanopore forming agent to form nanopores. It further provides an antireflection film for the exposure process.

Hereinafter, the present invention will be described in detail.

Nanopore formers of the present invention refers to any material capable of forming nanopores in a polymer insulating material by decomposition under appropriate conditions. Nanopores refer to spaces in insulating materials, which may contain gases or air and may be vacuum. Moreover, nanopores provide a round or oval shape.

As described above, the present invention relates to a low dielectric constant porous insulating material and antireflection film material. The porous material of the present invention consists of a combination of a thermally stable low dielectric material and a nanopore former that is removable by decomposition.

The porous material of the present invention is prepared by a method of forming nanopores by decomposing a nanopore forming agent that can be decomposed into a polynorbornene copolymer using a chemical method and then decomposing by an aqueous solution of methanol containing sodium hydroxide.

In particular, the copolymer provided by the present invention is characterized by thermally decomposing the nanopore former to make nanopores by treating at a temperature above the decomposition temperature of the nanopore former. The decomposition temperature of the nanopore former means a temperature at which the polynorbornene copolymer is thermally stable and can decompose only the nanopore former. Typically, the decomposition temperature of the nanopore formers does not exceed 450 ° C. More preferably, the decomposition temperature of the nanopore former means a temperature between 250 ° C and 450 ° C.

The thermally stable low dielectric insulating material for the porous material provided in the present invention is a cyclic polymer copolymer. More preferably, the cyclic polymer copolymer of the present invention is a norbornene cyclic olefin copolymer and a dicyclopentadiene cyclic olefin copolymer.

In addition, the nano-pore forming agent provided in the present invention is an ester (ester) polymer and ether (ether) polymer material. More preferably, it is a cyclic ester polymer and an ether type polymer. In addition, the nanopore former of the present invention may be a copolymer with a cyclic ester-based ether ether homopolymer.

Norbornene-based monomer

Monomers used as raw materials of the norbornene-based monomer containing a hydroxyl group provided by the present invention are 5-norbornene-2-methanol, cis-5-norbornene-endo-2,3-dica As cibol-5 anhydride (cis-5-norbornene-endo-2,3-dicarboxylic anhydride), DCPD (dicyclopentadiene), these materials are all available from Aldrich. In particular, the norbornene-based derivatives used in the present invention can be easily prepared by a simple liquid phase reaction rather than a high temperature and high pressure process, which is a process for producing norbornene-based derivatives. The structure of the norbornene derivatives provided by the present invention is as follows.

Norbornene Monomer I

Norbornene Monomer II

Norbornene Monomer III

In the norbornene-based monomers, R ₁ and R ₂ are each selected from hydrogen, a linear or branched alkyl group having 1 to 20 carbon atoms, and R ' ₃ and R' ₄ are each linked with carbon of R ' ₃ and R' ₄ . It forms an annular ring structure or a structure of. R ₃ and R ₄ also form a structure of formula (4).

-(CH ₂ ) _P- (O) _Q -R ₇

R ₇ is a hydrogen atom, a C ₁ -C ₂₀ linear or branched alkyl group, C ₁ -C ₄ dialkylaluminum, C ₁ -C ₄ trialkylsilane,

And a copolymer thereof, R is a linear or branched alkyl group of C ₁ to C ₁₀ , a and b are integers from 0 to 4, p is an integer from 0 to 10, q is 0 and M is an integer from 1 to 1,000.

Nano Pore Forming Agent

The nano-pore formers provided by the present invention include all materials pyrolyzed at temperatures between 250 ° C. and 400 ° C. below the glass transition temperature of the norbornene cyclic olefin copolymer. In particular, oligomers, homopolymers and their copolymers of cyclic esters such as lactide, glycolide, and caprolactone and linear esters such as lactic acid and glycolic acid Include coalescing. In addition, methyl methacrylate (hydroxy methacrylate), hydroxyethyl methacrylate (hydroxyethyl methacrylate), dimethylaminoeth- methacrylate (dimethylaminoeth-ylmethacrylate), ethylene oxide (ethylene oxide) and propylene oxide (propylene oxide) and oligomers using them , Homopolymers and copolymers.

Thermally stable low dielectric polymer

The thermally stable low dielectric polymer copolymer provided by the present invention is a norbornene cyclic olefin copolymer and a dicyclopentadiene cyclic olefin copolymer, and the copolymer of the present invention has a glass transition temperature of 250 ° C to 450 ° C, Refers to a copolymer of all compositions synthesized using norbornene, dicyclopentadiene, (bicyclo [2.2.1] hept-2-en-2-yl) alkyltrialkoxysilane and the norbornene derivatives (Formulas 1 to 3) as monomers. do.

In addition, the cyclic olefin copolymer provided by the present invention is a chain transfer of the olefin and cyclic olefin containing a hydroxy group and a trialkyloxysilyl group during the polymerization of the copolymer in order to introduce a nanopore former in the copolymer by post-reaction And copolymers prepared using zero. The structure of the thermally stable low dielectric copolymer provided by the present invention is as follows.

In the copolymer, R ₈ is

C ₁ -C ₁₀ is a linear or branched alkyl group, R ₁₁ (O) _q SiR ₁₂ or R ₁₁ (O) _q AlR _{12 It} is selected from R _11, R ₁₂ , R ₁₄ , R ₁₅ , R ₁₆ , R ₁₇ C ₁ ~ C ₅ is selected from linear or branched alkyl group and q is selected from 0 and 1. R ₉ and R ₁₀ are also selected from methyl, ethyl and propyl groups.

Porous polymer

The porous polymer provided in the present invention includes a block copolymer in which the nanopore-forming agent is bonded by a post reaction using the copolymer of Chemical Formulas 5-6.

* Description of the porous thin film manufacturing process using the above copolymer is as follows.

The copolymer solution of the concentration prepared on the surface-treated Si-wafer was immediately dropped while filtering with a filter (for example, 0.2 μm), and then the rotation speed (rpm) of the spin-coater was changed to form a thin film having a desired thickness. After heat-treating the prepared thin film in air at 90-200 ° C, the remaining solvent is blown, and then the temperature is gradually raised to 250-450 ° C in nitrogen or vacuum to pyrolyze the nano-meta-type nanopore former, thereby forming pores in place. It is to let.

More specifically, a feature of the present invention is to produce a porous material and a porous thin film material containing nanopores by pyrolysing organic components used as nanopore forming agents without crosslinking and curing the rotationally coated copolymer.

Example 1 norbornene monomer I (5-methoxymethyl-bicyclo [2.2.1] hept-2

-ene)

After dissolving 3.8 g of sodium hydride in 100 ml of THF, 2.5 g of 5-norbornene-2-methanol was added and reacted for 1 hour, followed by adding 20 g of methane iodide and reacting for 24 hours. Yield: 3.81 g (90%)

Example 2

Synthesis of norbornene monomer II (1,4-dihydro-1,4-methano-naphthalene-5,8-diol)

16 g of benzoquinone was added while refluxing 10 g of DCPD dissolved in a solvent of 100 ml of hexane at 160 ° C., and the temperature was decreased to 40 ° C. for 24 hours. 10 ml of pyridine and 25 g of (AcO) ₂ O were added to the product prepared from the reaction and reacted for 48 hours. The obtained product was dissolved in THF, cooled to 0 ° C., and 7 g of LiAlH ₄ was added and reacted for 24 hours. yield; 20 g (80%)

Example 3 Norbornene Monomer III (1,4,4a, 5,6,7,8,8a-octahydro-1,4-

methano-naphthalene-5-ol)

10 g of cyclopentadiene, 15 g of 2-cyclohexen-1-one, and 0.1 g of AlCl ₃ were dissolved in 100 ml of toluene, and then reacted at room temperature for 48 hours. After dissolving the product prepared in the reaction in THF, a small amount of LiAlH ₄ was added and reacted for 24 hours to synthesize monomer III. yield; 20g (79%)

Example 4-5 Modification of Norbornene-Based Derivatives

After dissolving 2.5 g of the norbornene derivatives obtained in Examples 2 and 3 in 100 ml of isopropanol, the mixture was stirred at 80 ° C. for 30 minutes, and then reacted for 3 hours by adding 2 g of KOH, followed by cooling to room temperature to modify the norbornene derivatives. .

Example 4

Example 5

Example 6-11 Introduction of Nanopore-forming Agent Polymer Chain to Norbornene-Based Derivatives

1 g of the norbornene derivatives obtained in Examples 4 and 5 were dissolved in a high-pressure reactor containing 30 ml of dimethylformamide, ethylene oxide or propylene oxide was added at room temperature, and the reactor was sealed and reacted at 80 ° C. for 3 hours. . After cooling to room temperature, the mixture was neutralized with acetic acid and the resulting solid was filtered and washed. The filtrate was removed under reduced pressure to yield a white solid. This was purified by column chromatography to give the desired product.

Example Norbornene derivatives Monomer yield 6 Example 4 Ethylene oxide (EO), (5 g) 78% 7 Example 4 Propylene Oxide (PO), (5 g) 70% 8 Example 4 EO + PO, (2g + 3g) 72% 9 Example 5 EO, (5 g) 75% 10 Example 5 PO, (5 g) 82% 11 Example 5 EO + PO, (2g + 3g) 75%

Example 12-15 Introduction of Nanopore-forming Agent Polymer Chain to Norbornene-Based Derivative II

5-norbornene-2-methanol, the norbornene-based monomers obtained in Examples 2 and 3, were added to a reactor containing 100 ml of toluene, the temperature was raised to 70 ° C, lactide and glycolide were added, and 0.05 g of Sn (Oct) ₂ was added. After the addition of the temperature was raised to 120 ℃ reacted for 8 hours. After cooling to room temperature, an excess of methanol was added to obtain a white solid.

Example Norbornene derivatives Monomer yield 12 5-norbornene-2-methanol D, L-lactide, (5g) 78% 13 Example 2 D, L-lactide, (5g) 70% 14 Example 3 D, L-lactide, (5g) 72% 15 5-norbornene-2-methanol glycolide, (5 g) 75% 16 Example 2 glycolide, (5 g) 82% 15 Example 3 glycolide, (5 g) 75%

Example 16-21 Synthesis of Macroinitiator Using Polynorbornene Copolymer

The following examples show the effect of the amount and structure of the norbornene-based monomer and the chain transfer agent used in the synthesis of the polynorbornene copolymer on the molecular weight of the copolymer. In a 500 ml reactor, 200 ml of chlorobenzene, 10 g of norbornene, norbornene-based monomers, chain transfer agent and catalyst [(η ³ -allyl) (cycloocta-1, 5-diene) nickel] tetrakis (3,5 -bis (trifluoromethyl)- The reaction was terminated by adding 67 mg of phenyl) borate and reacting at room temperature for 30 minutes. The prepared copolymer was stirred with excess methanol containing acid for 24 hours, washed with methanol again and dried in vacuo at 90 ° C. The results of the prepared copolymers are shown in Table 3. In addition, ¹ H-NMR measurement results of the copolymer prepared in Example 4 is shown in FIG. From the peak detected between 4-5 ppm, it can be seen that the chain transfer agent was well introduced into the copolymer. The copolymers obtained in Examples 4-9 can be used as initiators of ring-opening polymerization of cyclic esters such as lactide, glycolide, carprolactone and the like, and examples of these are illustrated in Examples 10-16.

Example Chain transfer agent Norbornene-based monomer Molecular Weight (x10 ³ ) (Mn / Mw) 16 - Monomer (18.7 mmol) (bicyclo [2.2.1] hept-2-en-2-yl) triethoxysilane (10 mmol) of Example 1 227/312 17 allyloxytrimethylsilane (1.25mmol) Monomer (18.7 mmol) (bicyclo [2.2.1] hept-2-en-2-yl) methyltriethoxysil ane (10 mmol) of Example 1 100/145 18 1-cyclohexenyloxytrimethylsilane (1.25mmol) Monomer of Example 1 (18.7 mmol) 117/281 19 1-cyclohexenyloxytrimethylsilane (1.25mmol) 5-ethoxymethyl-bicyclo [2.2.1] -hept-2-ene (18.7 mmol) 120/275 20 1-cyclohexenyloxytrimethylsilane (1.25mmol) 5-propoxymethyl-bicyclo [2.2.1] -hept-2-ene (18.7mmol) 106/223 21 1-cyclohexenyloxytrimethylsilane (1.25mmol) 5-octyloxymethyl-bicyclo [2.2.1] hept-2-ene (18.7 mmol) 98/189

Example 22-23 Synthesis of poly (norbornene-b-lactic acid) block copolymer I

10 g of the norbornene copolymer obtained in Example 17 was dissolved in 100 ml of toluene, and 0.01 ml of a 1M solution in which triethylaluminum was dissolved in toluene was added and reacted at room temperature for 4 hours. 2.5 g and 6.2 g of D, L-lactide were added to the reaction, and the reaction was completed at 120 ° C. for 24 hours, and then methanol was added to terminate the reaction. The prepared copolymer was washed with excess methanol and then dried at 90 ° C. in vacuo. Thermal properties of the prepared copolymers and the content of comonomers are shown in FIG. 2. The poly (lactic acid) block content was 13 and 45% by mass fraction, respectively. The results of ¹ H-NMR measurement and X-ray experiment of the copolymer having a mass fraction of 13% are shown in FIGS. 3 and 4.

Example 24-25 Synthesis of Poly (norbornene-b-lactic acid) Block Copolymer II

10 g of the norbornene copolymer obtained in Example 17 was dissolved in 100 ml of toluene, 10 g and 40 g of D and L-lactide were added thereto, and lactide was dissolved at 70 ° C., and then Sn (Oct) ₂ was 1 g and 4 g, respectively. It was added and the temperature was raised to 120 ℃ to react for 4 hours. After 4 hours, the reaction was terminated by adding methanol containing acid, washed with excess methanol, and dried at 90 ° C. in vacuo. The content of the poly (lactic acid) block introduced into the copolymer was 8 mol% and 35 mol%, respectively.

Example 26 Synthesis of Poly (norbornene-b-glycolic acid) Block Copolymer

10 g of the norbornene copolymer obtained in Example 17 was dissolved in 100 ml of toluene, 2 g of glycolide was dissolved, and glycolide was dissolved at 70 ° C., 0.02 g of Sn (Oct) ₂ was added, and the temperature was raised to 120 ° C. for 4 hours. Reacted for a while. After 4 hours, the reaction was terminated by adding methanol containing acid, washed with excess methanol, and dried at 90 ° C. in vacuo. The content of the poly (glycolic acid) block introduced into the prepared copolymer was 17% by volume and the number average molecular weight of the block copolymer was 119,000 (weight average molecular weight / number average molecular weight = 1.52).

Example 27 Synthesis of Poly (norbornene-b-lactic acid-r-glycolic acid) Block Copolymer

Example giant initiator obtained from Novo 17 was dissolved norbornene copolymer 10g in 100ml of toluene per each added 2g of lactide and glycolide and lactide and the glycolide was dissolved in 70 ℃ In the 0.04g of Sn (Oct) ₂ and 120 ℃ The temperature was raised to 4 hours for reaction. After 4 hours, the reaction was terminated by adding methanol containing acid, washed with excess methanol, and dried at 90 ° C. in vacuo. The content of poly (lactic acid-r-glycolic acid) block introduced in the prepared copolymer was 45% by volume fraction and the number average molecular weight of the block copolymer was 194,000 (weight average molecular weight / number average molecular weight = 1.71).

Example 28 Synthesis of Poly (norbornene-b-ε-caprolactone) Block Copolymer

10 g of the norbornene copolymer obtained in Example 17 was dissolved in 100 ml of toluene, and 5 g of ε-caprolactone was added and reacted at 0 ° C. for 4 hours. After 4 hours, the reaction was terminated by adding methanol containing acid, washed with excess methanol, and dried at 90 ° C. in vacuo. The content of the polycaprolactone block introduced into the prepared copolymer was 27% by volume and the number average molecular weight of the block copolymer was 137,000 (weight average molecular weight / number average molecular weight = 1.65).

Example 29 Synthesis of Poly (norbornene-b-ethylene oxide) Block Copolymer

Each of the norbornene-based copolymer obtained in Example 17 was dissolved in 100 ml of chlorobenzene, stirred at 80 ° C for 30 minutes, and then reacted for 3 hours by adding 1 g of KOH, followed by cooling to room temperature to modify the norbornene-based copolymer. . The modified copolymer was precipitated in methanol, dried in a vacuum oven, poured into a high-pressure reactor containing 30 ml of chlorobenzene, dissolved, ethylene oxide was added at room temperature, and the reactor was sealed and reacted at 80 ° C. for 1 hour. After cooling to room temperature, the mixture was neutralized with acetic acid and precipitated in methanol to obtain a white solid. The number average molecular weight of the block copolymer was 112,000 (weight average molecular weight / number average molecular weight = 1.55).

Example 30 Synthesis of Polynorbornene with Alkoxyamine at the Terminal

In a 500 ml reactor, 200 ml of chlorobenzene, 10 g of norbornene, 2.5 g of norbornene-based monomer (5-methoxymethyl-bicyclo [2.2.1] hept-2-ene), 0.35 g of chain transfer agent and a catalyst [(η ³ -allyl) ( cycloocta-1, 5-diene) nickel] tetrakis (3,5 -bis (trifluoromethyl) -phenyl) borate 95mg was added and reacted for 30 minutes.

Tanol was added to terminate the reaction. 1- (4'-oxa, a radical polymerization initiator, as a chain transfer agent

-2'-phenyl-11'-dodeceneoxy) -2,2,6,6-tetramethylpiperidine was used. The number average molecular weight was 63,000 (weight average molecular weight / number average molecular weight = 1.43).

Example 31 Synthesis of Poly (norbornene-b-hydroxyethyl methacrylate) Block Copolymer I

10 g of the norbornene copolymer introduced with alkoxyamine at the end obtained in Example 17 was dissolved in 50 ml of toluene, 5 g of hydroxyethyl methacrylate was added and reacted at 90 ° C. for 24 hours, and then the reaction was terminated by adding excess methanol. The molecular weight was measured by GPC. The number average molecular weight was 89,000 (weight average molecular weight / number average molecular weight = 1.59), and the volume fraction of poly (hydroxyethyl methacrylate) block was 27%.

Example 32 Synthesis of Poly (norbornene-b-hydroxyethyl methacrylate) Block Copolymer II

10 g of the norbornene copolymer obtained in Example 17 was dissolved in 100 ml of toluene, 1 g of 2-bromo-propionic acid-4- (chlorodimethylsilanyl) -butyl ester, 15 ml of pyridine, and 1 ml of triethylamine were reacted for 12 hours, followed by filtering. One solution was washed with saturated aqueous sodium bicarbonate solution. The organic layer was separated, dried over magnesium sulfate, and only the glass solution was separated to remove the solvent to synthesize a macroinitiator. 10 g of synthesized macroinitiator, 0.05 g of Cu (I) Br, 0.05 g of bipyridine, and 10 g of hydroxyethylmethacrylate were added, and the temperature was raised to 90 ° C. for 6 hours to synthesize a block copolymer. The number average molecular weight of the synthesized block copolymer was 150,000 (weight average molecular weight / number average molecular weight = 1.57).

Example 33-35 Synthesis of poly (norbornene-g-lactic acid) graft copolymer 1

100 ml of toluene in 500 ml reactor, (1,4-dihydro-1,4-methano-naphthalene-

5,8-diol) and 2g of toluene was added to dissolve the triethylaluminum a 1M solution 15ml was dissolved 9.5g norbornene was dissolved in 100ml of toluene was reacted for 4 hours with a catalyst solution [(η ³ -allyl a) (cycloocta - 1 , 5-diene) nickel] tetrakis (3,5-bis (trifluoromethyl)-phenyl) borate 67mg was added and reacted for 30 minutes, and excess methanol was added to terminate the reaction. The prepared copolymer was washed with excess methanol and then dried at 90 ° C. in vacuo. The number average molecular weight of the prepared copolymer was 65,000 (weight average molecular weight / number average molecular weight = 1.44). Dissolve 1 g of the well-coated copolymer in 200 ml of toluene, add 10 g, 20 g, and 50 g of lactide, respectively, and raise the temperature to 120 ° C. Then, add 0.1 g, 0.2 g, and 0.5 g of Sn (Oct) ₂ , respectively. The reaction was performed for a time to synthesize a graft copolymer. The number average molecular weights of the prepared graft copolymers were 81,000, 120,000, and 141,000, respectively.

Example 36 Synthesis of Poly (norbornene-g-lactic acid) Graft Copolymer

5 g of 5-norbornene-2-methanol, 200 g of lactide, and ₂ g of Sn (Oct) ₂ were added to a 500 ml reactor, and reacted for 24 hours while refluxing at 120 ° C. After 24 hours, the reaction was terminated by adding an excessive amount of methanol containing acid, and washed with excess methanol to prepare poly (lactic acid) in which norbornene was introduced at the end. 30g of poly (lactic acid) in which norbornene is introduced and 2.5g of norbornene and catalyst [(η ³ -allyl) (cycloocta-1,5-diene) nickel] tetrakis (3,5-bis (trifluoromethyl) -phenyl ) Borrate 63mg was dissolved in toluene and reacted for 18 hours to prepare a poly (norbornene-lactic acid) graft copolymer. The graft copolymer prepared was washed with excess methanol and then dried at 90 ° C. in vacuo. The number average molecular weight of poly (lactic acid) in the prepared copolymer was 4500, and the content of norbornene grafted with poly (norbornene-lactic acid) was 18 mol%.

Example 37 Synthesis of Poly (glycolic acid) Macroinitiator with Norbornene Introduced

After dissolving 0.5 g of 5-norbornene-2-methanol in 500 ml of toluene, 120 g of glycolide was added thereto, and the temperature was raised to 80 ° C. and stirred for 30 minutes. After 30 minutes, 1 g of Sn (Oct) 2 was added and the temperature was raised to 120 ° C. for 24 hours. After 24 hours, the reaction was terminated by adding an excess of methanol and dried at 90 ° C. in a vacuum for 24 hours. The number average molecular weight of the obtained polymer was 25,000 (weight average molecular weight / number average molecular weight = 1.15).

Example 38 Synthesis of Poly (norbornene-glycolic acid) Block Copolymer

100 ml of chlorobenzene in 500 ml reactor, (1,4-dihydro-1,4-methano-naphthalene-

5 g of 8, diol) and 1 g of poly (glycolic acid) obtained in Example 23 were added, followed by [(η ³ -allyl) (cycloocta-1,5-diene) nickel] tetrakis (3,5 -bis (trifluoromethyl 50 mg of) -phenyl) borate was added and reacted for 18 hours. The reaction was terminated by adding an excess of methanol. The molecular weight of the obtained poly (norbornene-glycolic acid) block copolymer was 34,000 (weight average molecular weight / number average molecular weight = 1.82), and the volume fraction of the poly (glycolic acid) block was 72%.

Example 39-41 Electro-optical characterization test of a thin film

After preparing a solution in which the copolymer prepared in the present invention was dissolved in 20 wt% in a mesitylene solvent, spin coating was performed at 2000 rpm for 30 seconds to prepare a thin film. An aluminum electrode was vacuum deposited on the thin film to investigate the electrical properties of the nanoporous copolymer thin film prepared by heat treatment up to 250-450 ° C. or by treatment with methanol containing a basic substance such as sodium hydroxide. The aluminum electrode was deposited under a condition of 5 mm in diameter, pressure of 10 ⁻⁵ torr or less, and evaporation rate of 0.5 nm / sec or less to obtain an electrode having a uniform thickness of about 100 nm.

In order to investigate the electrical properties of the copolymer, the dielectric constant was calculated from the maximum capacitance value of the C-V (Capacitance-Voltage) curve with a metal-insulator-semiconductor (MIS) structure.

This result shows that the dielectric constant and refractive index of the copolymers are markedly decreased as the molar ratio of the nanopore former is increased compared to that of the conventional polynorbornene homopolymer.

Example sample Thin film thickness (μm) Dielectric constant, k Refractive index (@ 632nm) 39 Example 17 1.5 2.6 1.508 40 Example 22 1.45 2.45 1.492 41 Example 23 0.8 2.51 1.498 42 Example 24 1.5 2.42 1.491 43 Example 26 1.41 2.28 1.32 44 Example 27 0.9 2.55 1.500 45 Example 28 1.45 2.12 1.27 46 Example 29 1.42 2.48 1.483 47 Example 31 1.33 2.21 1.30 48 Example 32 1.28 2.48 1.492 49 Example 33 1.51 2.25 1.31 50 Example 34 1.46 2.18 1.21 51 Example 35 1.48 2.02 1.13

Example 52 Preparation of Insulation Thin Film and Anti-Reflection Film Containing Nanopores

The copolymer produced by the above method is made into a thin film by spin coating. That is, the copolymer solution of the concentration prepared on the surface-treated Si wafer is immediately dropped while filtering with a filter (for example, 0.2 μm filter), and the rotation speed (rpm) of the spin coater is changed to form a thin film having a desired thickness. After heat-treating the prepared thin film in air at 90-220 ° C., the remaining solvent is blown, and then the temperature is raised to 250-450 ° C. in nitrogen or vacuum to decompose the nano-pore forming agent to form nano-pores. At this time, the heat treatment process must be performed at a temperature below the glass transition temperature of the prepared copolymer, because the heat treatment at a temperature above the glass transition temperature of the prepared copolymer, the nano-pore-forming agent decomposes and remains at the same time This is because the chain of the norbornene-based copolymer has fluidity, so that the structure of the formed nanopores is disrupted.

Example 53 Cross Section Analysis of a Thin Film

The cross section of the thin film was analyzed by FE-SEM and a cross-sectional photograph of a copolymer having a polylactide content of 13 wt% according to Example 10 is shown in FIG. 5. As a result of analyzing the image of FIG. 5, it could be seen that a pore having an average diameter of 22 nm and a dispersion degree of 5.6 nm was generated, and from this, a porous thin film was well prepared.

As described so far, the present invention is a polynorbornene copolymer containing a nano-pore forming agent and an insulating film prepared therefrom are easy to control the refractive index, has excellent thermal properties and low dielectric constant for the multi-chip package of the next-generation semiconductor industry There is an advantage having the characteristics required for the material and the material for the anti-reflection film used in the semiconductor exposure process. Particularly, if nanopores are introduced into the polymer thin film by pyrolysis using the pyrolysis temperature of the pyrolytic polymer which is lower than the glass transition temperature of the matrix polymer, there is no precedent in the world. It is thought that electricity will be provided for the development of various applications such as low dielectric materials for chip packages, optical wiring materials between chips, and anti-reflection films in optical microcircuit processing processes using 157nm.

Claims (5)

After copolymerizing at least one norbornene-based monomer with a pyrolytic monomer having a pyrolysis temperature lower than the glass transition temperature of polynorbornene, After coating the copolymer to prepare a thin film, The method of manufacturing a nanoporous thin film, characterized in that the nanopores are formed in the thin film by decomposing the thermally decomposable monomer by heat-treating the thin film at a temperature lower than the glass transition temperature of the polynorbornene and equal to or higher than the thermal decomposition temperature. The method of claim 1, wherein the heat treatment comprises thermally decomposing components excluding norbornene-type cyclic olefins in the thin film by heating the thin film to 250 to 400 ° C. 3. The method of claim 1, wherein the norbornene-based monomer is any one or more of the following Chemical Formulas 1 to 3. [Formula 1] In Formula 1, R ₁ and R ₂ are each selected from hydrogen, a linear or branched alkyl group having 1 to 20 carbon atoms, and R ' ₃ and R' ₄ are cyclic groups in which carbons of R ' ₃ and R' ₄ are linked together, respectively. A compound having the same structure as in the following Chemical Formula 1 or 2 is shown as a ring structure. [Formula 2] [Formula 3] R ₃ and R ₄ in Chemical Formulas 1 to 3 are the same as those of Chemical Formula 4, [Formula 4] -(CH ₂ ) _P- (O) _Q -R ₇ R ₇ is a hydrogen atom, a C ₁ -C ₂₀ linear or branched alkyl group, C ₁ -C ₄ dialkylaluminum, C ₁ -C ₄ trialkylsilane, And their copolymers, R is a C ₁ to C ₁₀ linear or branched alkyl group, a and b are integers from 0 to 4, p is an integer from 0 to 10, q is selected from 0 and 1, m is 1 It is an integer up to 1,000. 4. A process according to claim 3, wherein R ₁ and R ₂ are each hydrogen and R ' ₃ and R' ₄ have the structure of formula 4 as monomer. [Formula 4] -(CH ₂ ) _P- (O) _Q -R ₇ In the formula, R ₇ and R, a, p, q, and m are as defined above. The method of claim 3, wherein the copolymer is composed of norbornene-based monomers of any one or more of formulas 1 to 3 and / or (bicyclo [2.2.1] -hept-2-en-2-yl) alkyltrialkoxysilane, The content of the (bicyclo [2.2.1] hept-2-en-2-yl) alkyltrialkoxysilane in the copolymer is 1-50 mol%. In the following copolymers, R ₉ and R ₁₀ are selected from methyl, ethyl and propyl groups. [Formula 5]