JP2004140341A - Insulating film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an insulating film, etc., which can sufficiently enhance a mechanical strength and electric characteristics. <P>SOLUTION: Interlayer insulating films 5, 7 (insulating films) provided in a memory capacitor cell 8 are formed between a gate electrode 3 and an opposed electrode 8 provided on a silicon wafer 1. The films 5, 7 each contains an organic silicon borazine polymer in such a manner that a relative permittivity is 2.6 or less, a Young' modulus is 5 GPa or more and leakage current is 1×10<SP>-8</SP>A/cm<SP>2</SP>or less. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to an insulating coating containing a borazine-based compound, and an electronic component using the same.

With the recent miniaturization, high output, and high-speed signals of communication devices, the realization of film flattening by CMP has been combined with the insulation coating of electronic components (IMD: metal interlayer insulating film, ILD: metal lower layer). Insulation film, PMD: pre-metal insulation film, etc.) are required to have not only heat resistance, mechanical properties, hygroscopicity, adhesiveness, moldability, high etch selectivity, etc. but also particularly low dielectric constant.

In general, the propagation speed (v) of a signal on a wiring and the relative dielectric constant (ε) of an insulating material with which the wiring material contacts have a relationship represented by v = k / √ε (k is a constant). This is because, in order to increase the signal propagation speed and reduce the wiring delay, it is necessary to increase the frequency range to be used or to lower the relative dielectric constant of the insulating material as much as possible.

A low dielectric constant material which is currently put into practical use on a mass production basis as such an insulating coating material is a SiOF film (CVD method) having a relative dielectric constant of about 3.5. Studies on organic SOGs (Spin @ On @ Glass) of 0.6 to 3.0, organic polymers, and the like are in progress. Further, as an insulating coating material having a relative dielectric constant smaller than 2.6, a porous material having voids in the film has been proposed (for example, see Patent Documents 1 and 2), and is applied to an interlayer insulating coating of LSI. Studies are being actively conducted.

In addition, as another low dielectric constant material, borazine having a molecular structure in which carbon atoms of benzene are substituted with nitrogen atoms and boron atoms is known to have a calculated dielectric constant lower than that of benzene. (For example, see Patent Document 3). It is also known that a borazine-containing silicon polymer thin film has high heat resistance (for example, see Patent Document 4).
JP-A-11-310411 JP-A-11-322992 JP 2000-340689 A JP 2002-155143 A

However, the above-mentioned insulating film, which achieves a low dielectric constant by making it porous, tends to have a decrease in film strength as the low dielectric constant is promoted. For example, when the film is planarized by CMP or the like, In addition, problems such as peeling of a film are likely to occur, and there is a serious problem that process adaptability and reliability of a device using such an insulating film are reduced. In addition, since the conventional borazine-containing compound uses a metal catalyst such as platinum at the time of synthesis, when this is used as an insulating coating material, a metal component such as platinum is inevitably contained as an impurity in the obtained insulating coating. Will remain. For example, when a metallic impurity is present in the interlayer insulating film, a leak current is generated, which may be a factor of deteriorating or deteriorating the performance as the insulating film.

Therefore, the present invention has been made in view of such circumstances, and has an insulating film capable of sufficiently increasing mechanical strength and electrical characteristics, and has excellent mechanical strength and improved reliability which can effectively prevent wiring delay. It is intended to provide an electronic component that can be used.

In order to solve the above-mentioned problems, an insulating coating according to the present invention includes a component having a borazine skeleton in a molecular structure, has a relative dielectric constant of 2.6 or less, a Young's modulus of 5 GPa or more, In addition, the leakage current is 1 × 10 ⁻⁸ A / cm ² or less.

The insulating film thus configured has a relative dielectric constant of 2.6 or less, and does not require a porous structure for lowering the relative dielectric constant, which is applied to a conventional organic polymer. Therefore, a decrease in film strength due to the formation of a porous layer is prevented. On the other hand, if the Young's modulus is less than 5 GPa, the mechanical properties of the film are inferior, and when such an insulating film is used as an interlayer insulating film, there is a disadvantage that the film is not suitable for a planarization process. Further, when the leak current is 1 × 10 ⁻⁸ A / cm ² or less, device characteristics such as elements may be deteriorated when such an insulating film is used as, for example, an interlayer insulating film.

絶 縁 The insulating coating of the present invention is preferably formed of a borazine-based resin composition having a metal impurity content of 30 ppm or less. If the content of metal impurities in the borazine-based resin composition as a raw material exceeds 30 ppm, the low relative dielectric constant required when the insulating coating of the present invention is used, for example, as an interlayer insulating film of a multilayer wiring having an ultrafine structure May not be achieved, or the occurrence of leakage current may become significant.

Further, the electronic component according to the present invention constitutes an electronic device such as a semiconductor device or a liquid crystal device which is effectively formed by using the insulating coating of the present invention, that is, a base provided with a conductive layer, An interlayer insulating film provided on a base and comprising an insulating film according to the present invention.

According to the insulating coating of the present invention, since the dielectric constant is sufficiently reduced, the electrical characteristics are excellent, and the mechanical strength can be sufficiently increased because the dielectric constant does not need to be lowered by making the insulating layer porous. Further, according to the electronic component of the present invention, by providing the insulating coating of the present invention, wiring delay can be effectively prevented, mechanical strength is excellent, and reliability can be improved.

Hereinafter, preferred embodiments of the insulating film of the present invention will be described. The insulating coating of the present invention contains a component having a borazine skeleton in its molecular structure as an essential component. The component having a borazine skeleton may be a polymer having a substituted or unsubstituted borazine skeleton in the main chain or side chain. For example, Chemical {Review}, vol. 73-91 (1990). And CHEMTECH @, July 1994, pp. 29-37. And the like.

で表される繰り返し単位を有してなる有機ケイ素ボラジン系ポリマーが好ましい。 Further, from the viewpoints of film formability and chemical stability, the following formula (1):

An organosilicon borazine-based polymer having a repeating unit represented by

は、以下のいずれかを示し、

Note that in equation (1),

Indicates one of the following,

は、以下のいずれかを示す。

And

Indicates one of the following:

破 線 Further, the broken line in the formula (1) means that a bond is generated at the carbon derived from the alkynyl group in the borazine residue.

Here, in the formula (1), R ¹ represents an alkyl group, an aryl group, an aralkyl group or a hydrogen atom. In this case, the alkyl group has 1 to 24, preferably 1 to 12 carbon atoms. The aryl group has 6 to 20 carbon atoms, preferably 6 to 10 carbon atoms. Further, the aralkyl group has 7 to 24 carbon atoms, preferably 7 to 12 carbon atoms. More specifically, as the group R ¹ , an alkyl group such as a methyl group, an ethyl group, an isopropyl group, a t-butyl group, an octyl group, an aryl group such as a phenyl group, a naphthyl group, a biphenyl group, a benzyl group, and a phenethyl group And the like. Among them, a methyl group, an ethyl group, a phenyl group or a hydrogen atom is more preferable.

In the formula (1), R ² represents an alkyl group, an aryl group, an aralkyl group or a hydrogen atom, and the alkyl group has 1 to 24, preferably 1 to 12 carbon atoms. In this case, the aryl group has 6 to 20, preferably 6 to 10 carbon atoms. The aralkyl group has 7 to 24 carbon atoms, preferably 7 to 12 carbon atoms. More specifically, as the group R ² , an alkyl group such as a methyl group, an ethyl group, an isopropyl group, a t-butyl group, an octyl group, an aryl group such as a phenyl group, a naphthyl group, a biphenyl group and an anthracenyl group, and a benzyl group And an aralkyl group such as a phenethyl group and a fluorenyl group, and a hydrogen atom. Of these, a methyl group, a phenyl group and a hydrogen atom are more preferable.

Further, in the formula (1), R ³ and R ⁴ represent the same or different monovalent groups selected from an alkyl group, an aryl group, an aralkyl group and a hydrogen atom, and among these, an alkyl group, an aryl group Or a hydrogen atom is more preferred. In this case, the alkyl group has 1 to 24, preferably 1 to 12 carbon atoms. The aryl group has 6 to 20 carbon atoms, preferably 6 to 10 carbon atoms. Further, the aralkyl group has 7 to 24 carbon atoms, preferably 7 to 12 carbon atoms. More specifically, as groups R ³ and R ⁴ , alkyl groups such as methyl group, ethyl group, isopropyl group, t-butyl group, octyl group, aryl groups such as phenyl group, naphthyl group, biphenyl group, and benzyl group And an aralkyl group such as a phenethyl group, a hydrogen atom and the like. Among them, a methyl group, a phenyl group and a hydrogen atom are more preferable.

Further, in the formula (1), R ⁵ represents a substituted or unsubstituted aromatic divalent group, an oxypoly (dimethylsiloxy) group, or an oxygen atom. In this case, the aromatic divalent group has 6 to 24 carbon atoms, preferably 6 to 12 carbon atoms. The aromatic divalent group includes, in addition to a divalent aromatic hydrocarbon group (such as an arylene group), an arylene group containing a heteroatom such as oxygen as a linking group. Examples of the substituent that may be bonded to the aromatic divalent group include an alkyl group, an aryl group, and an aralkyl group. More specifically, as the base R ^5, a phenylene group, a naphthylene group, an arylene group such as biphenylene group, a substituted arylene group such as diphenyl ether group, such as an oxygen atom., A phenylene group, diphenyl ether group or oxygen among these Atoms are more preferred.

Furthermore, in the formula (1), R ⁶ represents an alkyl group, an aryl group or an aralkyl group. In this case, the alkyl group has 1 to 24, preferably 1 to 12 carbon atoms. The aryl group has 6 to 20 carbon atoms, preferably 6 to 10 carbon atoms. Further, the aralkyl group has 7 to 24 carbon atoms, preferably 7 to 12 carbon atoms. More specifically, as the group R ⁶ , an alkyl group such as a methyl group, an ethyl group, an isopropyl group, a t-butyl group, an octyl group, an aryl group such as a phenyl group, a naphthyl group, a biphenyl group, a benzyl group, a phenethyl group And the like.

In the formula (1), a and b each represent the number of repeating units, and a is a positive integer, preferably 1 to 20,000, more preferably 3 to 10,000, and particularly preferably 5 to 10,000. It is. B is 0 or a positive integer, preferably 0 to 1000, more preferably 0 to 100. However, a and b indicate their constituent ratios, and are not limited to any form of the bonding state (block copolymerization, random copolymerization, etc.).

In such a copolymer, the ratio (a: b) of the respective numbers of a and b is not particularly limited, and the a / b ratio is large, that is, the ratio of the chain structure in the polymer main chain is low. When the amount is relatively large, it is expected that the processability of the copolymer will be improved by increasing the solubility of the copolymer in the solvent and lowering the melting point. On the other hand, when the a / b ratio is small, that is, when the ratio of the crosslinked structure in the polymer main chain is relatively large, it is expected that the heat resistance and the combustion resistance of the copolymer will be improved. Therefore, depending on the use or the like, or the structure of each monomer unit of the copolymer and the combination thereof, the optimum a / b ratio of the copolymer that gives good processability, heat resistance, and combustion resistance is obtained. The range can be set as appropriate.

Furthermore, in the formula (1), p represents 0 or a positive integer, q represents 0 or a positive integer, and has a relationship of p + q + 2 = n with n described later. The preferable range of p is 0-10, more preferably 1-8. The preferable range of q is 0 to 10, more preferably 1 to 8.

又は下記式（３）；

で表される２価の基であり、同一分子鎖において、Ｚ¹が式（２）又は（３）のいずれか一方の構造で構成されていても、或いは、両方の構造が同一分子鎖内に含まれていても構わない。なお、式（２）及び（３）におけるＲ³、Ｒ⁴、Ｒ⁵、Ｒ⁶、ｐ及びｐは前述したものと同様である。 Further, in the formula (1), Z ¹ is the following formula (2);

Or the following formula (3);

In the same molecular chain, even if Z ¹ is constituted by either ^one of the formulas (2) and (3), or both structures are in the same molecular chain. May be included. Note that R ³ , R ⁴ , R ⁵ , R ⁶ , p and p in the formulas (2) and (3) are the same as those described above.

The molecular weight of the polymer having such a borazine skeleton (number-average molecular weight of a value measured by gel permeation chromatography (GPC) and converted using a standard polystyrene calibration curve) is preferably 500 to 5,000,000, Preferably it is 1000-1,000,000. When the molecular weight (Mn) is excessively low, for example, less than 500, heat resistance and mechanical properties of an insulating film described later tend to be inferior. For example, when such an insulating film is used as an interlayer insulating film, prebaking is difficult. There is a possibility that peeling or the like may easily occur when flattening after film formation is performed by CMP. On the other hand, if the molecular weight (Mn) is excessively high, for example, more than 5,000,000, the workability of the insulating film deteriorates. For example, a via hole for forming a metal plug such as W is formed in the insulating film in a desired shape. Control may be difficult.

The organosilicon borazine-based polymer represented by the formula (1) is obtained by polymerizing B, B ', B "-trialkynylborazines and hydrosilanes in a polymerization solvent in the presence of a metal-containing catalyst. Or by removing the metal-containing catalyst by hydroboration polymerization of B, B ', B "-trihydroborazines and bis (alkynylsilanes) in the absence of a catalyst. Can be manufactured.

Specific examples of B, B ', B "-trialkynyl borazines (x) include B, B', B" -triethynyl borazine, B, B ', B "-triethynyl-N, N', N" -Trimethylborazine, B, B ', B "-tri (1-propynyl) borazine, B, B', B" -triphenylethynylborazine, B, B ', B "-triphenylethynyl-N, N', N "-trimethylborazine, B, B ', B" -triethynyl-N, N', N "-triphenylborazine, B, B ', B" -triphenylethynyl-N, N', N "-triphenyl Borazine, B, B ', B "-ethynyl-N, N', N" -tribenzylborazine, B, B ', B "-tris (1-propynyl) -N, N', N" -trimethylborazine Is mentioned. However, it is not limited to these. In addition, one kind of B, B ', B "-trialkynylborazines can be used alone, but two or more kinds of B, B', B" -trialkynylborazines may be used in combination.

The hydrosilanes include bis (monohydrosilane) s, bis (dihydrosilane) s, bis (trihydrosilane) s, and poly (hydrosilane) s. Specific examples include m-bis (dimethylsilyl) benzene, p-bis (dimethylsilyl) benzene, 1,4-bis (dimethylsilyl) naphthalene, 1,5-bis (dimethylsilyl) naphthalene, m-bis (methyl) Ethylsilyl) benzene, m-bis (methylphenylsilyl) benzene, p-bis (methyloctylsilyl) benzene, 4,4′-bis (methylbenzylsilyl) biphenyl, 4,4′-bis (methylphenethylsilyl) diphenyl ether , M-bis (methylsilyl) benzene, m-disilylbenzene, 1,1,3,3-tetramethyl-1,3-disiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, 1,3 , 5,7,9-Pentamethylcyclopentasiloxane, 1,3,5,7-tetraethylcyclotetrasiloxy Emissions, 1,3,5 triphenyl cyclotrisiloxane, 1,3,5,7-tetraphenyl cyclotetrasiloxane, 1,3,5,7-tetra benzyl cyclotetrasiloxane and the like. However, it is not limited to these.

The metal-containing catalyst used in producing the organosilicon borazine-based polymer is not particularly limited, but is generally used for hydrosilylation of acetylenes and olefins, and contains a homogeneous metal-containing catalyst or a heterogeneous metal-containing catalyst. A catalyst can be used. Among them, a heterogeneous metal-containing catalyst is preferable. Particularly, it promotes the polymerization reaction of B, B ', B "-trialkynylborazines and hydrosilanes, and the metal component is eluted in the reaction substrate and a polymerization solvent described later. It is desirable that the polymer be not filtered and be removed by filtration after the polymerization.

Examples of such a heterogeneous metal-containing catalyst include elemental metals such as platinum powder, palladium powder, and nickel powder, platinum carbon, platinum alumina, platinum silica, palladium carbon, palladium alumina, palladium silica, rhodium carbon, rhodium alumina, and rhodium. Carrier metal alone such as silica, Raney nickel, or B.I. Marciniec ed., Comprehensive Handbook on Hydrosilylation, Pergamon Press (1992) and Polymer Journal, polymer-supported rhodium catalyst according to 34,97-102 (2002) (polym-PPh 2 · RhCl (PPh 3) 3, polym-PPh 2 RhCl ₃ , polym-CH ₂ Cl ₂ .RhCl (CO) (PPh ₃ ) _2, etc. and polymer-supported platinum catalyst (Polym-CH ₂ SH / H ₂ PtCl ₆ ) (where poly is poly (styrene- main-chain skeleton such as co-divinylbenzene), and surface-functionalized silica gel-supported platinum catalyst (Silica- (CH ₂ ) ₃ —SH / H ₂ PtCl ₆ ). These catalysts may be used alone or in combination of two or more.

The amount of the catalyst used is such that the molar ratio of the metal atom to the raw material compound having a smaller molar amount among the B, B ', B "-trialkynyl borazines or hydrosilanes is in the range of 0.000001 to 5. It is suitable.

In addition, when producing the organosilicon borazine-based polymer represented by the formula (1), a polymerization solvent is used to maintain the fluidity of the system and to facilitate removal of the metal-containing catalyst after polymerization. As the polymerization solvent, various solvents other than those that react with the raw materials can be used. Specific examples include aromatic hydrocarbon-based, saturated hydrocarbon-based, aliphatic ether-based, and aromatic ether-based solvents, and more specifically, toluene, benzene, xylene, ethylbenzene, propylbenzene, and hexyl. Examples include benzene, hexane, tetrahydrofuran, ethylene glycol dimethyl ether, diphenyl ether and the like. These polymerization solvents may be used alone or in combination of two or more.

は Further, the amount of the polymerization solvent used is desirably 50 to 100,000 parts by weight of the polymerization solvent (s) based on 100 parts by weight of the total amount of B, B ', B "-trialkynylborazines and hydrosilanes.

Further, when the organosilicon borazine-based polymer represented by the formula (4) is produced, the charged molar ratio of B, B ', B "-trialkynylborazines and hydrosilanes is B, B', B" -trialkyl. The amount of the hydrosilane is preferably in the range of 0.1 to 10 mol per mol of the alkynylborazine, and more preferably, the amount of the hydrosilane is preferably 1 mol per mol of B, B ', B "-trialkynylborazine. Are in the range of 0.2 to 5 moles.

Furthermore, the reaction temperature and the reaction time for producing the organosilicon borazine-based polymer represented by the formula (4) are as follows: B, B ', B "-trialkynylborazines and hydrosilanes are polymerized, There is no particular limitation as long as an organosilicon borazine-based polymer having a molecular weight can be obtained.Specifically, the reaction temperature depends on the reactivity of the raw materials and the activity of the catalyst, but the reaction temperature is within a range of -20 ° C to 200 ° C. The reaction temperature is more preferably in the range of 0 ° C. to 150 ° C., more preferably 0 ° C. to 100 ° C. On the other hand, the reaction time is preferably 1 minute to 10 days, more preferably The range is 1 hour to 10 days, particularly preferably 2 hours to 7 days.

The polymerization reaction is desirably performed in an inert atmosphere such as dry nitrogen or argon, and can be performed in the air from the viewpoint of simplifying the device configuration.

合成 After the synthesis of the organosilicon borazine-based polymer, the reaction solution is filtered to remove the metal-containing catalyst, whereby a filtrate containing the organosilicon borazine-based polymer can be obtained. As a filtration method, a commonly used filtration method such as natural filtration, suction filtration, and pressure filtration can be used. Further, as the filter medium, filter paper, filter cloth, resin membrane and the like can be used, and the removal of the catalyst by natural sedimentation or centrifugal separation is also included in the "filtration" aspect of the present invention.

Further, after the polymerization reaction, particles (metal scavenger) which are insoluble in the polymerization system and can adsorb the metal component derived from the metal catalyst are added to the polymerization system (polymerization solution), and thereafter, the metal components remaining in the polymerization solution are removed. The adsorbed metal scavenger may be filtered off. Such treatment is effective in reducing the metal content, particularly when a homogeneous metal-containing catalyst is used.

Then, the filtrate containing the organosilicon borazine-based polymer thus obtained is concentrated under reduced pressure or concentrated by heating to remove the solvent, and is used as a raw material of the borazine-based resin composition as an insulating coating material as a solid polymer. You can also. Further, a material obtained by reprecipitation, gel filtration column, GPC (gel permeation chromatogram) column, or the like can be used as a raw material of the borazine-based resin composition.

In addition, the borazine-based resin composition as the insulating coating material is obtained by adding a solvent having a higher boiling point than the polymerization solvent to the filtrate of the reaction solution obtained in the process of producing the organosilicon borazine-based polymer described above, and polymerizing the filtrate. The solvent is distilled off (therefore, a mixture of the high-boiling point solvent and the organosilicon borazine-based polymer is obtained), or the solid-state organosilicon borazine-based polymer is dissolved in the solvent. It can also be manufactured by using the method described above.

Examples of the solvent or diluting solvent capable of dissolving such a borazine-based resin composition include those having a polymer having a borazine skeleton in the main chain or side chain, that is, those capable of dissolving without reacting with an organosilicon borazine-based polymer. Specifically, hydrocarbon solvents such as toluene, benzene, xylene, mesitylene, ethylbenzene, propylbenzene, hexylbenzene, tetralin, pentane, hexane, heptane, cyclohexane, dimethylcyclohexane, ethylene glycol dimethyl ether, tetrahydrofuran, 1,4- Ether solvents such as dioxane and diphenyl ether; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclopentanone and cyclohexanone; ester solvents such as ethyl acetate, butyl acetate, pentyl acetate and γ-butyrolactone; , N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, quinoline Halogen-based solvents such as chloroform, dimethyl sulfoxide and the like.

These solvents or diluting solvents may be used alone or in combination of two or more. The amount of the solvent or the diluent used is preferably such that the solid content concentration of the organosilicon borazine-based polymer is 0.1 to 60% by mass.

Further, it is not preferable that a metal component is contained in the component having a borazine skeleton in the molecular structure and thus the insulating coating of the present invention containing the borazine skeleton, and a borazine-based resin composition having a metal impurity content of 30 ppm or less. And more preferably 10 ppm or less. If the metal impurity concentration exceeds 30 ppm, the occurrence of a leak current due to a metal component remaining in the insulating film becomes remarkable, or the relative dielectric constant of the insulating film may be excessively increased. The performance itself may be affected.

方法 The following can be exemplified as a method for forming an insulating film according to the present invention using such a borazine-based resin composition. First, a borazine-based resin composition is applied to a substrate such as a silicon wafer, a metal substrate, or a ceramic substrate by an immersion method, a spray method, a screen printing method, a spin coating method, or the like to form a coating film. Then, the coating is heated and dried in air or an inert gas such as nitrogen at 60 to 500 ° C. for about 10 seconds to 2 hours to remove the solvent. Thus, an insulating coating made of a thin film without stickiness can be obtained. The thickness of the insulating film is not particularly limited, but is preferably 0.05 to 50 μm, more preferably 0.1 to 10 μm, and particularly preferably 0.2 to 5 μm from the viewpoint of heat resistance and the like.

電子 Further, examples of the electronic component according to the present invention using the insulating film formed as described above include those having an insulating film such as a semiconductor element, a liquid crystal element, and a multilayer wiring board. The insulating film of the present invention is used as an insulating film such as a surface protective film, a buffer coat film, and an interlayer insulating film in a semiconductor device, as a surface protective film and an insulating film in a liquid crystal device, and as an interlayer insulating film in a multilayer wiring board. It can be preferably used as a film.

Specifically, the semiconductor element includes individual semiconductor elements such as a diode, a transistor, a capacitor, a compound semiconductor element, a thermistor, a varistor, and a thyristor, a DRAM (dynamic random access memory), and an SRAM (static random access memory). Memory (memory), EPROM (erasable programmable read only memory), mask ROM (mask read only memory), EEPROM (electrically erasable programmable read only memory), flash memory, etc. ) Devices, microprocessors, theoretical (circuit) devices such as DSP and ASIC, integrated circuit devices such as compound semiconductors represented by MMIC (monolithic microwave integrated circuit), hybrid integrated circuits (Hybrid IC), light emitting diode, a photoelectric conversion element such as a charge coupled device, the light emitting element, such as a semiconductor laser element and the like. Examples of the multilayer wiring board include a high-density wiring board such as an MCM.

Here, FIG. 1 is a schematic sectional view showing a preferred embodiment of an electronic component according to the present invention. The memory capacitor cell 8 (electronic component) functions as a gate electrode 3 (word line) provided on a silicon wafer 1 (base) on which diffusion regions 1A and 1B are formed via a gate insulating film 2B made of an oxide film. ) And an opposing electrode 8C provided thereabove. Interlayer insulating films 5 and 7 (insulating coatings) having a two-layer structure are formed. Side wall oxide films 4A and 4B are formed on the side wall of the gate electrode 3, and a field oxide film 2A is formed in the diffusion region 1B on the side of the gate electrode, thereby performing element isolation.

(4) The interlayer insulating film 5 is applied on the gate electrode 3 and the field oxide film 2A, and is formed by spin-coating the borazine-based resin composition described above. In the vicinity of the gate electrode 3 in the interlayer insulating film 5, a contact hole 5A in which an electrode 6 functioning as a bit line is embedded is formed. Further, a flattened interlayer insulating film 7 is applied on the flattened interlayer insulating film 5, and a storage electrode 8A is embedded in a contact hole 7A formed so as to penetrate both. . The interlayer insulating film 7 is formed by spin-coating a borazine-based resin composition similarly to the interlayer insulating film 5. The counter electrode 8C is provided on the storage electrode 8A via a capacitor insulating film 8B made of a high dielectric substance. The interlayer insulating films 5 and 7 may have the same composition or different compositions.

According to the electronic component such as the memory capacitor cell 8 having the insulating film of the present invention configured as described above, the relative permittivity of the insulating film is sufficiently reduced as compared with the related art, so that the wiring in the signal propagation is reduced. The delay time can be sufficiently reduced, and the generation of a leak current can be effectively prevented. As a result, high performance of the element can be achieved, and high reliability can be realized.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

<Production Example 1>
(Production of borazine-based resin composition 1)
B, B ', B "-triethynyl-N, N', N" -trimethylborazine (0.50 mmol) and p-bis (dimethylsilyl) benzene (0.50 mmol) are dissolved in ethylbenzene (4 ml), and 5% platinum alumina (in terms of platinum) 0.1 mmol) and stirred at 50 ° C. under nitrogen for 7 days. A part of the reaction solution was taken out and subjected to gas chromatography (GC) analysis. As a result, the monomers B, B ', B "-triethynyl-N, N', N" -trimethylborazine and p-bis (dimethylsilyl) ) It was confirmed that the benzene peak had disappeared. From GPC analysis, the molecular weight (based on standard polystyrene) of the product was Mn = 2500 (Mw / Mn = 2.0). The reaction solution containing the platinum-alumina catalyst was filtered with a disposable membrane filter unit manufactured by ADVANTEC to obtain a borazine-based resin composition 1.

<Production Example 2>
(Production of borazine-based resin composition 2)
B, B ', B "-triethynyl-N, N', N" -trimethylborazine (0.50 mmol) and 1,3,5,7-tetramethylcyclotetrasiloxane (0.50 mmol) were dissolved in ethylbenzene (4 ml), and 5% platinum was added. Alumina (0.1 mmol in terms of platinum) was added, and the mixture was stirred at 50 ° C. for 7 days under nitrogen. A part of the reaction solution was taken out and subjected to gas chromatography (GC) analysis. As a result, the peak of the monomer B, B ', B "-triethynyl-N, N', N" -trimethylborazine disappeared. It was confirmed. From GPC analysis, the molecular weight (based on standard polystyrene) of the product was Mn = 3000 (Mw / Mn = 2.2). The reaction solution containing the platinum-alumina catalyst was filtered with a disposable membrane filter unit manufactured by ADVANTEC to obtain a borazine-based resin composition 2.

<Production Example 3>
(Production of borazine-based resin composition 3)
B, B ', B "-triethynyl-N, N', N" -trimethylborazine (0.50 mmol) and p-bis (dimethylsilyl) benzene (0.50 mmol) were dissolved in ethylbenzene (4 ml). Polymer Journal, 34, 97-102. A polymer-supported platinum catalyst (Polym-CH2SH / H2PtCl6) described in (2002) (0.01 mmol in terms of platinum) was added, and the mixture was stirred at 50 ° C under nitrogen for 5 days. A part of the reaction solution was taken out and subjected to gas chromatography (GC) analysis. As a result, the monomers B, B ', B "-triethynyl-N, N', N" -trimethylborazine and p-bis (dimethylsilyl) ) It was confirmed that the benzene peak had disappeared. From GPC analysis, the molecular weight (based on standard polystyrene) of the product was Mn = 3800 (Mw / Mn = 2.5). The reaction solution containing the polymer-supported platinum catalyst was filtered through a disposable membrane filter unit manufactured by ADVANTEC to obtain a borazine-based resin composition 3.

<Production Example 4>
(Production of borazine-based resin composition 4)
B, B ', B "-tris (1'-propynyl) -N, N', N" -trimethylborazine 3.6 g (15 mmol), 1,3,5,7-tetramethylcyclotetrasiloxane 3.6 g ( 15 mmol) was dissolved in 150 ml of mesitylene, 30 μl of a xylene solution of platinum divinyltetramethyldisiloxane (containing 2% of platinum) was added, and the mixture was stirred at 40 ° C. for 1 day under nitrogen. Thereto was added 30 μl of a xylene solution of platinum divinyltetramethyldisiloxane (containing 2% of platinum), and the mixture was stirred at 40 ° C. for 1 day under nitrogen. Subsequently, 0.36 g (1.5 mmol) of 1,3,5,7-tetramethylcyclotetrasiloxane was added, and the mixture was stirred at 40 ° C. for 1 day under nitrogen. A part of the reaction solution was taken out, and subjected to gas chromatography (GC) analysis. As a result, the monomer B, B ′, B ″ -tris (1′-propynyl) -N, N ′, N ″ -trimethylborazine was removed. It was confirmed that the peak of 1,3,5,7-tetramethylcyclotetrasiloxane had disappeared. From GPC analysis, the molecular weight (based on standard polystyrene) of the product was Mn = 11000 (Mw / Mn = 29).

1.0 g of a metal scavenger of formula (4) (3-mercaptopropyl-functionalized silica gel, manufactured by Aldrich) was added to the reaction solution, and the mixture was stirred at room temperature for 2 hours. Thereafter, the metal scavenger on which platinum was adsorbed was filtered through a PTFE membrane filter manufactured by ADVANTEC to obtain a borazine-based resin composition 4 of the present invention.

<Production Example 5>
(Production of Platinum-Containing Borazine Resin Composition 5)
B, B ', B "-triethynyl-N, N', N" -trimethylborazine (0.50 mmol) and p-bis (dimethylsilyl) benzene (0.50 mmol) were dissolved in ethylbenzene (8 ml), and a homogeneous metal catalyst, platinum divinyltetrane, was dissolved. 15 μl of a xylene solution of methyldisiloxane (containing 2% of platinum) was added, and the mixture was stirred at room temperature under nitrogen for 3 days. A part of the reaction solution was taken out and subjected to gas chromatography (GC) analysis. As a result, the monomers B, B ', B "-triethynyl-N, N', N" -trimethylborazine and p-bis (dimethylsilyl) ) It was confirmed that the benzene peak had disappeared. From GPC analysis, the molecular weight (based on standard polystyrene) of the product was Mn = 4300 (Mw / Mn = 2.5). This reaction liquid was used as borazine-based resin composition 5.

<Example 1>
(Manufacture of insulating coating 1)
The borazine-based resin composition 1 obtained in Production Example 1 was filtered through a filter, and the filtrate was dropped on a low-resistivity silicon wafer (substrate; resistivity <10 Ωcm) and spin-coated. Next, the silicon wafer was heated on a hot plate at 200 ° C. for 1 hour in a nitrogen atmosphere, and then baked at 300 ° C. for 30 minutes and at 400 ° C. for 30 minutes to obtain an insulating film 1 of the present invention.

<Example 2>
(Manufacture of insulating film 2)
An insulating coating 2 of the present invention was obtained in the same manner as in Example 1 except that the borazine-based resin composition 2 obtained in Production Example 2 was used instead of the borazine-based resin composition 1.

<Example 3>
(Manufacture of insulating coating 3)
An insulating coating 3 of the present invention was obtained in the same manner as in Example 1, except that the borazine-based resin composition 3 obtained in Production Example 3 was used instead of the borazine-based resin composition 1.

<Example 4>
(Manufacture of insulating coating 4)
An insulating film 4 of the present invention was obtained in the same manner as in Example 1 except that the borazine-based resin composition 4 obtained in Production Example 4 was used instead of the borazine-based resin composition 1.

<Comparative Example 1>
(Manufacture of insulating coating 5)
An insulating coating 5 was obtained in the same manner as in Example 1 except that the borazine-based resin composition 5 obtained in Production Example 5 was used instead of the borazine-based resin composition 1.

<Metal content measurement>
The metal content of the borazine-based resin composition was measured by an atomic absorption method using AA-6650G manufactured by Shimadzu Corporation. Table 1 shows the concentration of platinum contained in the borazine-based resin compositions 1 to 5.

<Relative permittivity measurement>
The relative dielectric constant of each insulating film obtained in each of the examples and comparative examples was measured. Here, the “relative dielectric constant” of the insulating film in the present invention refers to a value measured in an atmosphere of 23 ° C. ± 2 ° C. and a humidity of 40 ± 10%, and is composed of an Al metal and an N-type low resistivity substrate (Si). It is determined from the measurement of the charge capacity between wafers.

Specifically, after forming an insulating film in each of the examples and comparative examples, Al metal is vacuum-deposited on the insulating film in a vacuum evaporation apparatus so as to have a thickness of about 0.1 μm in a circle having a diameter of 2 mm. . As a result, a structure in which the insulating coating is disposed between the Al metal and the low resistivity substrate is formed. Next, the charge capacity of this structure was measured at an operating frequency of 1 MHz using a device in which a dielectric test fixture (HP16451B, manufactured by Yokogawa Electric) was connected to an LF impedance analyzer (HP4192A, manufactured by Yokogawa Electric). It was measured.

Then, the measured value of the charge capacity is calculated by the following equation;
Relative dielectric constant of insulating film = 3.597 × 10 ⁻² × charge capacity (pF) × film thickness of insulating film (μm);
And the relative dielectric constant of the insulating film was calculated. As the thickness of the insulating film, a value measured by an ellipsometer L116B manufactured by Gartner was used.

<Leak current measurement>
Using each wafer for which the relative permittivity was measured, a leak current was measured using a leak current measuring device.

<Young's modulus measurement>
For each of the insulating coatings, the Young's modulus was measured as an index of the film strength using a nano indenter DCM manufactured by MTS.

Table 2 shows the measurement results of the relative dielectric constant, leak current, and Young's modulus of the insulating coatings 1 to 5.

FIG. 1 is a schematic sectional view showing a preferred embodiment of an electronic component according to the present invention.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 ... Silicon wafer (substrate), 1A, 1B ... Diffusion area, 2A ... Field oxide film, 2B ... Gate insulating film, 3 ... Gate electrode, 4A, 4B ... Side wall oxidation Film, 5,7 ... Interlayer insulating film (insulating film), 5A, 7A ... Contact hole, 6 ... Bit line, 8 ... Memory cell capacitor (electronic component), 8A ... Storage electrode , 8B ... capacitor insulating film, 8C ... counter electrode.

Claims (3)

It has a molecular structure containing a component having a borazine skeleton, has a relative dielectric constant of 2.6 or less, a Young's modulus of 5 GPa or more, and a leak current of 1 × 10 ⁻⁸ A / cm ² or less. An insulating coating characterized by the following. The insulating coating according to claim 1, wherein the insulating coating is formed from a borazine-based resin composition having a metal impurity content of 30 ppm or less. An electronic component comprising: a base provided with a conductive layer; and an interlayer insulating film formed on the base and comprising the insulating coating according to claim 1.

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