JP2003347290A - Metal diffusion barrier film and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metal diffusion barrier film which has both a low dielectric constant and a metal diffusion barrier property, can reduce wiring resistance, and has a superior filming property and a method for forming the film. <P>SOLUTION: Disclosed in the metal diffusion barrier film containing a silicon- containing resin containing a repetitive unit represented by a formula (1): -Si(R<SB>1</SB>R<SB>2</SB>)-R<SB>3</SB>- among repetitive units. In the formula (1), R<SB>1</SB>, R<SB>2</SB>are alkyl groups which may independently have hydrogen atoms and substituents whose carbon numbers are 1 to 30, alkenyl groups which may have substituents whose carbon numbers are 1 to 30, alkynyl groups which may have substituents whose carbon numbers are 1 to 30, or aromatic groups which may have substituents, and R<SB>3</SB>is -C≡C-, -CH<SB>2</SB>- which may have a substituent bonded to at least one -C≡C-, an alkylene group which may have a substituent which is bonded to at least one -C≡C- and whose carbon number is 2 to 30, an alkenylen group which may have a substituent which is bonded to at least one -C≡C- and whose carbon number is 2 to 30, an alkynylen group which may have a substituent which is bonded to at least one -C≡C- and whose carbon number is 2 to 30, or a bivalent aromatic group which may have a substituent which is bonded to at least -C≡C-. <P>COPYRIGHT: (C)2004,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal diffusion barrier film used for preventing diffusion of metal such as metal wiring, a method for forming the metal diffusion barrier film, and a semiconductor device using the same.

[0002]

2. Description of the Related Art Conventionally, a material mainly composed of aluminum has been used for wirings and contacts of a semiconductor device, and a material mainly composed of silicon oxide has been used for an interlayer insulating film.
However, if the semiconductor device is further miniaturized for higher integration of the semiconductor device, the speeding up of the semiconductor device will reach the limit due to RC delay. For this reason, the wiring material is changed from aluminum to copper having a small resistance in order to reduce the wiring resistance, or the interlayer insulating film is changed from silicon oxide (dielectric constant 4) to a dielectric material 4 in order to reduce the wiring capacitance.
It is being studied to change to a smaller, so-called low dielectric constant material. Low dielectric constant materials include, for example, methylsilsesquioxane (MS)
Q) are known.

[0003] Although copper wiring has lower resistance than aluminum wiring, there is a problem that when heat load is applied, Cu atoms and ions are easily diffused into the insulating film. When copper diffusion occurs,
A short circuit occurs between the wirings, and the performance of the semiconductor device deteriorates. Therefore, for example, when a copper wiring is formed by a dual damascene method, a metal diffusion barrier film for preventing copper diffusion is interposed between the copper wiring and the low dielectric constant interlayer insulating film.

There are two types of metal diffusion barrier films: conductive metal diffusion barrier films (Ta, TaN, TiN, WN, etc.) and insulating metal diffusion barrier films (silicon nitride, silicon carbide, etc.). In the case of forming a copper wiring by a dual damascene method, a conductive metal diffusion barrier film is formed on a side surface and a bottom surface of a portion where the copper wiring is buried, and the copper wiring after the copper wiring is buried and planarized by chemical mechanical polishing (CMP). An insulating metal diffusion barrier film was generally used on the upper surface.

Incidentally, the resistance of a conductive metal diffusion barrier film is higher than the resistance of copper. Therefore, in the wiring structure using the metal diffusion barrier film, the wiring resistance is increased as compared with the case where the wiring is formed only with copper, and the effect of increasing the speed of the semiconductor device is small even if the copper wiring is adopted. There is. The effect of the increase in resistance can be reduced by reducing the thickness of the conductive metal diffusion barrier film, but a certain thickness or more is required to maintain the copper diffusion barrier property of the metal diffusion barrier film. Had limitations.

The relative permittivity of the conventionally used insulating metal diffusion barrier film is about 7 for silicon nitride and about 4 to 4.5 for silicon carbide. However, the effective permittivity sometimes increased. In order to solve this problem, a metal diffusion barrier film that can prevent copper diffusion while being a low dielectric constant material has been studied.

For example, in the proceedings of the 62nd Annual Meeting of the Japan Society of Applied Physics, p.649 (lecture No. 13a-X-8), plasma polymerization (PE-MVP; Plasma Enhanced Monomer-Vapor Po
DVS-BCB (di
vinyl siloxane bisbenzocyclobutene) is a film having both a low dielectric constant and a metal diffusion barrier property.
It is reported that when S-BCB is used for an interlayer insulating film, a conductive metal diffusion barrier film is not required, so that the wiring resistance can be reduced as compared with the case where a conductive barrier film is used. However, since the DVS-BCB film is formed by the plasma polymerization method, there is a problem that the film forming speed is slow and the apparatus cost is high.

[0008]

An object of the present invention is to provide a film having both a low dielectric constant and a metal diffusion barrier property.
It is an object of the present invention to provide a metal diffusion barrier film excellent in film formability and a method for forming the film.

[0009]

SUMMARY OF THE INVENTION The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that a low dielectric constant film containing a silicon-containing resin having a specific repeating unit or a cured product thereof has a metal diffusion barrier property. Have been found to be able to form a film at low cost and in a short time, and have completed the present invention.

That is, the metal diffusion barrier film according to the present invention is characterized in that the repeating unit contains a silicon-containing resin containing the repeating unit represented by the general formula (1) or a cured product thereof.

[0011]

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(Wherein R ₁ and R ₂ each independently represent a hydrogen atom, an alkyl group which may have a substituent having 1 to 30 carbon atoms, or a substituent having 1 to 30 carbon atoms) Or an alkynyl group having 1 to 30 carbon atoms which may have a substituent, or an aromatic group which may have a substituent, wherein R ₃ is —C≡C—, at least one of -C≡C-
Linked may have a substituent -CH ₂ and - at least one -C≡C- and linked alkylene group which may have a substituent group having 2 to 30, at least one -C
An alkenylene group optionally having 2 to 30 carbon atoms connected to ≡C-, an alkynylene group optionally having 2 to 30 carbon atoms connected to at least one —C≡C— And a divalent aromatic group which may have a substituent linked to at least one -C≡C-. As the repeating unit represented by the general formula (1), phenylsilyleneethynylene represented by the following formula (2)
1,3-phenyleneethynylene units are preferred.

[0013]

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Such a metal diffusion barrier film is suitable as a copper diffusion barrier film. Further, in the method for forming a metal diffusion barrier film according to the present invention, a liquid composition containing a silicon-containing resin having a repeating unit represented by the general formula (1) in a repeating unit is applied to a substrate and heat-treated. It is characterized by: The repeating unit represented by the general formula (1) is phenylsilyleneethynylene-1,3-phenyleneethynylene represented by the general formula (2).

The heat treatment is preferably performed at a temperature of 20 ° C. or more and 600 ° C. or less in an inert gas atmosphere or under reduced pressure.
A semiconductor device according to the present invention has the metal diffusion barrier film formed thereon.

[0016]

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, a metal diffusion barrier film, a method of manufacturing the same, and a semiconductor device according to the present invention will be described. [Metal Diffusion Barrier Film and Production Method Thereof] The metal diffusion barrier film according to the present invention contains a silicon-containing resin containing a repeating unit represented by the following general formula (1) or a cured product thereof in a repeating unit. It is characterized by:

[0017]

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In the formula, R ₁ and R ₂ independently represent
A hydrogen atom, an alkyl group which may have a substituent having 1 to 30 carbon atoms, an alkenyl group which may have a substituent having 1 to 30 carbon atoms, and a substituent which has 1 to 30 carbon atoms A good alkynyl group or an aromatic group which may have a substituent. Specific examples of the alkyl group which may have a substituent having 1 to 30 carbon atoms include a methyl group, an ethyl group, a propyl group and a hexyl group. Group, cyclohexyl group, octyl group, dodecanyl group, trifluoromethyl group, 3,3,3-trifluoropropyl group, chloromethyl group, aminomethyl group, hydroxymethyl group, silylmethyl group, 2-methoxyethyl group and the like. And the alkenyl group which may have a substituent having 1 to 30 carbon atoms includes vinyl, 2-propenyl, isopropenyl, 3-butenyl, 5-hexenyl, and 1,3-butadiyl. Group, 3,3,3-trifluoro-1-propenyl group and the like, from 1 to 30 carbon atoms
Examples of the alkynyl group which may have a substituent include an ethynyl group, a 1-propynyl group, a 2-propynyl group, a butynyl group, a trimethylsilylethynyl group, a phenylethynyl group, and the like, or may have a substituent. Examples of the aromatic group include phenyl, naphthyl, pyrazinyl, 4-methylphenyl, 4-vinylphenyl, 4-ethynylphenyl, 4-aminophenyl, 4-chlorophenyl, 4-hydroxyphenyl, -Carboxyphenyl group, 4-methoxyphenyl group, 4-silylphenyl group and the like.

R ₃ is -C≡C-, at least 1
-CH optionally having a substituent linked to two -C≡C-
_2- , carbon number 2 linked to at least one -C≡C-
An alkylene group which may have a substituent of from 2 to 30, an alkenylene group which may have a substituent having 2 to 30 carbon atoms linked to at least one -C≡C-, and at least one -C≡C- An alkynylene group which may have a substituent having 2 to 30 carbon atoms and is linked to at least one -C≡C-
And a divalent aromatic group which may have a substituent linked to the above. At least one -C≡C- and linked substituent may have a -CH ₂ - as a methylene group, a fluoromethylene group -C≡C- can be mentioned one or two attached groups, Examples of the alkylene group optionally having a substituent having 2 to 30 carbon atoms linked to at least one —C≡C— include an ethylene group, a propylene group, a tetramethylene group,
-C≡C- is 1 or 2 in a tetrafluoroethylene group or the like.
And at least one -C−C-
Examples of the alkenylene group which may have a substituent having 2 to 30 carbon atoms and which are linked to a vinylene group, a propenylene group, a butadienylene group, and the like include one or two groups having -C≡C- bonded thereto. Examples of the alkynylene group which may have a substituent having 2 to 30 carbon atoms and which is connected to two —C≡C— groups include one or two —C≡C— bonded to an ethynylene group, a propynylene group, a butynylene group, or the like. Examples of the divalent aromatic group which may have a substituent linked to at least one —C≡C— include a phenylene group, a naphthylene group, a biphenylene group, an anthracenedil group, a pyridinedyl group, and a thiophenedyl group. Dilyl group, fluorophenylene group, chlorophenylene group, methylphenylene group,
One or two -C≡C- bonds to a silylphenylene group, a hydroxyphenylene group, an aminophenylene group, a phenylenemethylenephenylene group, a phenyleneoxyphenylene group, a phenylenepropylidenephenylene group, a phenylene (hexafluoropropylidene) phenylene group, or the like. The following groups are mentioned. Specific examples of the repeating unit represented by the general formula (1) include silyleneethynylene, methylsilyleneethynylene, phenylsilyleneethynylene, silyleneethynylene-1,3-phenyleneethynylene, phenylsilyleneethynylene-1, 3-phenyleneethynylene (general formula (2)), silyleneethynylene-1,4-phenyleneethynylene, silyleneethynylene-1,2-phenyleneethynylene, methylsilyleneethynylene-1,3
-Phenyleneethynylene (general formula (3)), methylsilyleneethynylene-1,4-phenyleneethynylene, methylsilyleneethynylene-1,2-phenyleneethynylene, dimethylsilyleneethynylene-1,3-phenyleneethynylene Dimethylsilyleneethynylene-1,4-phenyleneethynylene, dimethylsilyleneethynylene-
1,2-phenyleneethynylene, diethylsilyleneethynylene-1,3-phenyleneethynylene, phenylsilyleneethynylene-1,3-phenyleneethynylene (general formula (4)), phenylsilyleneethynylene-1,4- Phenyleneethynylene, phenylsilyleneethynylene-
1,2-phenyleneethynylene, diphenylsilyleneethynylene-1,3-phenyleneethynylene, hexylsilyleneethynylene-1,3-phenyleneethynylene, vinylsilyleneethynylene-1,3-phenyleneethynylene (general formula ( 5)), ethinylsilyleneethynylene-
1,3-phenyleneethynylene, 2-propenylsilyleneethynylene-1,3-phenyleneethynylene, 2-propynylsilyleneethynylene-1,3-phenyleneethynylene, trifluoromethylrosiryleneethynylene-1,
3-phenyleneethynylene, 3,3,3-trifluoropropylsilyleneethynylene-1,3-phenyleneethynylene, 4-methylphenylsilyleneethynylene-1,3
-Phenyleneethynylene, 4-vinylphenylsilyleneethynylene-1,3-phenyleneethynylene, 4-ethynylphenylsilyleneethynylene-1,3-phenyleneethynylene, phenylethynylsilyleneethynylene-
1,3-phenyleneethynylene, silyleneethynylene (5-methyl-1,3-phenylene) ethynylene, phenylsilyleneethynylene (5-methyl-1,3-phenylene) ethynylene, phenylsilyleneethynylene (5-
(Silyl-1,3-phenylene) ethynylene, phenylsilyleneethynylene (5-hydroxy-1,3-phenylene) ethynylene, phenylsilyleneethynylene-2,7
-Naphthyleneethynylene, silyleneethynylene-5,1
0-anthracenedilethynylene, phenylsilyleneethynylene-4,4'-biphenyleneethynylene (general formula (6)), phenylsilyleneethynylene-1,4-phenylenemethylene-1 ', 4'-phenyleneethynylene Phenylphenyleneethynylene-1,4-phenylene-2,2
-Propylidene-1 ', 4'-phenyleneethynylene, phenylsilyleneethynylene-1,4-phenylene-2,2
-(1,1,1,3,3,3-hexafluoropropylidene) -1 ′, 4′-phenyleneethynylene (general formula (7)), phenylsilyleneethynylene-1,4-phenyleneoxy-1 ', 4'-phenyleneethynylene (general formula (8)), phenylsilyleneethynylene-2,5-pyridinedylethynylene, phenylsilyleneethynylene-2,5-thiophenedyrylethynylene, methylsilyleneethylene Nylenemethyleneethynylene, phenylsilylene-1,4-phenylene (phenylsilylene) ethynylene-1 ′, 3′-phenyleneethynylene (general formula (9)),
Phenylsilyleneoxy (phenylsilylene) ethynylene-1 ′, 3′-phenyleneethynylene (general formula (1)
0)), phenylsilyleneoxy (phenylsilylene)
Ethynylene-1 ′, 4′-phenyleneethynylene, phenylsilyleneimino (phenylsilylene) ethynylene
1 ', 3'-phenyleneethynylene, phenylsilyleneimino (phenylsilylene) ethynylene-1', 4'-phenyleneethynylene, silylene-1,3-phenyleneethynylene, silylene-1,4-phenyleneethynylene, silylene -1,2-phenyleneethynylene, phenylsilylene-1,3-phenyleneethynylene, phenylsilylene-1,4-phenyleneethynylene, phenylsilylene-1,2-phenyleneethynylene, diphenylsilylene-1,3-phenylene Ethynylene, methylsilylene-1,
3-phenyleneethynylene, methylsilylene-1,4-
Phenyleneethynylene, methylsilylene-1,2-phenyleneethynylene, dimethylsilylene-1,3-phenyleneethynylene, diethylsilylene-1,3-phenyleneethynylene, phenylsilylene-1,3-butadiynylene, diphenylsilylene-1 , 3-butadiynylene,
Phenylsilylenemethyleneethynylene, diphenylsilylenemethyleneethynylenemethylene, phenylsilylenemethyleneethynylenemethylene, silylene-1,4-phenyleneethynylene-1 ′, 4′-phenylene, methylsilylene-1,4-phenyleneethynylene-1 A unit selected from ', 4'-phenylene, dimethylsilylene-1,4-phenyleneethynylene-1', 4'-phenylene, phenylsilylene-1,4-phenyleneethynylene-1 ', 4'-phenylene, etc. No. Among them, a silicon-containing resin containing a phenylsilyleneethynylene-1,3-phenyleneethynylene unit represented by the general formula (2) is preferable because of its excellent heat resistance.

[0020]

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The silicon-containing resin used in the present invention may contain at least one of the above-mentioned constituent units, and may contain two or more of the above-mentioned constituent units. Further, the silicon-containing resin may be an oligomer of about a dimer of the above structural unit. Furthermore, as long as the silicon-containing resin contains the above-mentioned constitutional unit, it may contain a constitutional unit other than the above-mentioned constitutional unit. The structural units other than those described above are not particularly limited as long as the object of the present invention is not impaired.

The weight average molecular weight of the silicon-containing resin is not particularly limited, but is preferably from 500 to 500,000. The form of these silicon-containing resins is solid or liquid at normal temperature. As a method for producing the silicon-containing resin used in the present invention as described above, a method of performing a dehydrogenation copolymerization of a diethynyl compound and a silane compound using a basic oxide, a metal hydride, or a metal compound as a catalyst (particularly, Kaihei 7-900
No. 85, JP-A-10-120689, JP-A-11-158187) and a method of performing dehydrogenation polymerization of an ethynylsilane compound using a basic oxide as a catalyst (JP-A-9-143271). A method of reacting a magnesium reagent with dichlorosilanes (JP-A-7-10
2069, JP-A-11-029579),
Dehydrogenation copolymerization of diethynyl and silane compounds using cuprous chloride and tertiary amine as catalysts (Hua Qin Li
u and John F. Harrod, The Canadian Journal of Chem
istry, Vol. 68, 1100-1105 (1990)) and the like, but are not particularly limited to these methods. The metal diffusion barrier film of the present invention is manufactured by applying a liquid composition containing the above-mentioned silicon-containing resin to a substrate and heat-treating the liquid composition. When the silicon-containing resin is in a liquid state, it can be applied as it is, but preferably, it is desirably dissolved in a solvent to form a liquid composition and applied.

In preparing the liquid composition, a solvent that dissolves the above silicon-containing resin is preferably used. As the solvent, for example, benzene, toluene, aromatic solvents such as xylene, tetrahydrofuran, dioxane, monoglyme, diglyme, ether solvents such as anisole,
Ketone solvents such as acetone and cyclohexanone; aliphatic alcohol solvents such as methanol, ethanol, propanol, and furfuryl alcohol; halogen-containing solvents such as dichloromethane, chloroform, and chlorofluorocarbon; N, N-dimethylimidazolidinone, dimethylformamide, and dimethylacetamide And organic polar solvents such as N-methylpyrrolidone. Further, various additives such as a dispersant, a solvent, a colorant, and an inorganic filler may be contained without departing from the scope of the present invention. The content of the silicon-containing resin in the liquid composition is appropriately selected depending on the film thickness, composition, and the like of the film to be formed.
The content is desirably 0% by weight or less, preferably 1 to 30% by weight. When the concentration is within the above range, the concentration is too low to cause a defect in the film, and since the concentration is too high, the viscosity of the liquid material is not too high, and a flat film can be easily formed.

As a method of applying the liquid composition, a known method such as a spin coating method or a dip coating method can be used, but is not limited thereto. In order to form the film smoothly and in a short time, it is preferable to form the film by a spin coating method. When a film is formed by spin coating, the number of rotations, the rotation time, the atmosphere during rotation, and the like are appropriately selected depending on the viscosity of the liquid composition, the target film thickness, and the like. The temperature and time of the heat treatment may be selected according to the type of metal used for the wiring and the thickness of the film to be formed, the type of the film, the contained components, and the like. The time is preferably from 1 second to 10 hours. If the temperature is lower than 20 ° C., it may take a long time to form a film. When the temperature is 600 ° C. or higher, the membrane is partially decomposed and easily adsorbs water and the like, which makes the handling complicated. The heat treatment can be performed not only at a constant temperature depending on the composition or the like, but also at a multi-stage heat treatment at a plurality of temperatures. The heat treatment is preferably performed in an atmosphere of an inert gas such as nitrogen, helium, or argon, or under reduced pressure. As a heat treatment method, various heat treatment methods such as a hot plate, an infrared furnace, and an electric furnace can be used.
Further, a plurality of heat treatment methods can be used in combination.

In the present invention, the silicon-containing resin may be cured by the heat treatment (particularly when the treatment temperature is high and the time is long). The curing is considered to be due to the formation of a crosslinked structure by a hydrosilylation reaction between Si—H and C≡C and a Diels-Alder reaction of C≡C. Further, the liquid composition containing the silicon-containing resin may contain a curing catalyst. The curing catalyst is not particularly limited as long as it promotes curing.

Examples of the catalyst include Group 8 and Group 9 of the periodic table.
Or a Group 10 transition metal such as iron, cobalt, nickel
Kel, ruthenium, rhodium, palladium, osmiu
Iridium, platinum and the like. Also, transition metals
Complexes include Group 8, Group 9 or Group 10 of the periodic table.
Transition metal complexes such as RhXL_Three(Where X is a halogen
Atom, L is phosphine, phosphinite, phosphona
Indicates phosphite or phosphite. The same applies hereinafter), Rh_Four(C
O)₁₂, Rh₆(CO)₁₆, [RhX (CO)_Two]_Two, RhX (CO) L_Two, RhH (CO)
L_Three, [RhX (CH_Two= CH_Two)_Two]_Two, [RhX (COD)]_Two(Where COD is shik
Shows looctadiene. The same applies hereinafter), [CpRhX_Two]_Two(formula
Where Cp is cyclopentadienyl group or pentamethyl
Represents a clopentadienyl group. The same applies hereinafter), CpRh (CH_Two= C
H_Two)_Two, RuX_TwoL_Three, Ru (CO)_Five, Ru (CO)_TwoL_Three, Ru (CO)_FourL, Ru_Three(C
O)₁₂, RuL_Five, [RuX_Two(CO)_Three]_Two, RuXH (CO) L_Three, RuH_TwoL_Four, RuH_Four
L_Three, RuX_Two(RCN) L_Two(Wherein R represents an alkyl group, an aryl group,
Or an aralkyl group. The same applies hereinafter), [CpRuX_Two]_Two, Ru
(COD) (COT) (where COT represents cyclooctatetraene
You. Hereinafter the same), Fe (CO)_Five, Fe (CO)_ThreeL_Two, Os_Three(CO)₁₂, OsH
_Two(CO) L_Three, Co_Two(CO) 8, Co_Two(CO)_FiveL_Two, Co_Four(CO)₁₂, HCo (C
O)_Four, CoXL_Three, Ir_Four(CO)₁₂, IrX (CO) L_Two, [IrX (CH_Two= C
H_Two)_Two]_Two, IrX (CH_Two= CH_Two) L_Two, [IrX (COD)]_Two, IrXL_Three, IrH
_FiveL_Two, Ni (CO)_Four, Ni (COD)_Two, Ni (CH_Two= CH_Two) L_Two, NiL_Four, NiX_TwoL
_Two, PdX_Two(RCN)_Two, PdX_TwoL_Two, PdX_Two(RNC) _Two, Pd (OCOCH_Three)_Two, Pd
L_Four, Pd (CO) L_Three, Pd (CH_Two= CH_Two) L_Two, Pd (COD)_Two, Pd (dba)
_Two(In the formula, dba represents dibenzylideneacetone. The same applies hereinafter.)
Like), PtX_Two(RCN)_Two, PtX_Two(COD), PtX_TwoL_Two, [PtX_Two(CH_Two= C
H_Two)]_Two, Pt (COD)_Two, PtL_Four, PtL_Three, Pt (CO) L_Three, PtHXL_Two, Pt
(dba)_TwoCan also be used as a catalyst. these
Is 1 to 10 equivalents of NEt_Three, PPh_Three
May also be used. For example, PtCl
_Two(PPh_Three)_TwoNEt_ThreePd (dba)_TwoTo PPh_Three
Is used by adding 2 equivalents. These complexes also
Can be used alone or as a mixture of two or more
it can. The amount of the transition metal or transition metal complex used is represented by the general formula
0.00 to 1 mol of the repeating unit represented by (1)
01-0.5 mol, preferably 0.001-0.1 mol
It is.

In the metal diffusion barrier film according to the present invention, a reinforcing agent, a filler, an antioxidant, a heat stabilizer, an ultraviolet absorber, a flame retardant, and a flame retardant aid are provided as long as the object of the present invention is not impaired. ,
It may contain an antistatic agent, a lubricant, and a colorant. The metal diffusion barrier film according to the present invention has an effect of preventing the diffusion of various metals, but has a characteristic of being excellent in barrier properties particularly when copper, which is easily diffused by a thermal load, is subjected to a thermal load.

[Semiconductor Device] The semiconductor device according to the present invention is characterized in that the metal diffusion barrier film described above is formed on a substrate. As a substrate, depending on its purpose,
Boron, phosphorus and the like are doped with p-type and n-type silicon substrates, quartz substrates, etc., and various insulating films, metal wirings, etc. are patterned or laminated to form semiconductor devices on those substrates. A substrate or the like is used.
Examples of the semiconductor device include memories such as an SRSM and a DRAM.

The metal diffusion barrier film may be provided on the side or bottom surface of the wiring buried portion to suppress the diffusion of the wiring metal to the substrate side when forming the metal wiring by, for example, a dual damascene method. desirable. The method for forming the metal diffusion barrier film is not particularly limited, and the above-described method is suitably employed. In the present invention, the metal diffusion barrier film can be used as an interlayer insulating film or an inter-wiring insulating film.

Further, in the present invention, two or more metal diffusion barrier films may be formed by lamination, and further, the metal diffusion barrier film according to the present invention may be laminated with a conventional insulating film or conductive metal barrier film. May be. This makes it possible to further enhance the metal diffusion barrier performance.

[0031]

The metal diffusion barrier film of the present invention has excellent metal diffusion barrier properties, particularly copper diffusion barrier properties, and can be used as a metal diffusion barrier film for copper wiring and the like. In the case where the wiring of the semiconductor device is formed by, for example, a dual damascene method, by using the film of the present invention for the interlayer insulating film,
Since it is not necessary to use a conductive metal diffusion barrier film on the side and bottom surfaces of the metal wiring, an increase in wiring resistance can be suppressed and the speed of the semiconductor device can be increased. Furthermore, the membranes of the present invention are not expensive devices such as plasma polymerization devices,
Since the film can be formed by an inexpensive device such as a spin coater, wiring can be formed at low cost.

[0032]

The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these examples and comparative examples.

[0033]

Synthesis Example 1 Poly (phenylsilyleneethynylene-1,3-phenyleneethynylene) was synthesized based on the methods described in JP-A-7-90085 and JP-A-10-204181. In a 50-liter stainless steel reaction vessel, 3.39 kg of MgO, 2.16 kg of phenylsilane, and 2.16 kg of m-diethynylbenzene were obtained by calcining Mg (OH) ₂ at 400 ° C. for 7 hours in a nitrogen stream.
82 kg and 27.4 liters of toluene as a solvent were charged. Next, at 30 ° C. for 1 hour in a nitrogen atmosphere,
The reaction was carried out at 0 ° C. for 1 hour, at 50 ° C. for 1 hour, at 60 ° C. for 1 hour, and further at 80 ° C. for 2 hours, for a total of 6 hours. The reaction solution was filtered to separate and remove MgO. The filtered reaction solution was concentrated under reduced pressure to 9.44 kg (polymer concentration: 43% by weight). The weight average molecular weight of the concentrate is 3400, and the number average molecular weight is 15
00. 9.45 kg of n-heptane was added to the concentrated solution, stirred at room temperature for 30 minutes, and allowed to stand for 2 hours. An upper phase containing a cloudy low molecular weight component and a lower phase containing a brown high molecular weight component were separated. From the bottom, 3.91 kg of the lower phase was taken out, and then 4.42 kg of the upper phase was taken out. The solvent in the upper phase was distilled off under reduced pressure to obtain 1.32 kg of an orange viscous liquid having a weight average molecular weight of 1460 and a number average molecular weight of 850 (yield 27%). Further, the lower phase was concentrated under reduced pressure and dried under reduced pressure at 60 ° C. for 23 hours, and the weight average molecular weight was 4890,
2.74 kg of 130 pale yellow powders were obtained (yield 56
%). The structure of liquid and powdery poly (phenylsilyleneethynylene-1,3-phenyleneethynylene) is I
R, confirmed by NMR spectrum.

[0034]

Example 1 "Measurement of Copper Diffusion Barrier Performance" (Preparation of Liquid Composition) 1.4 g of the powdery poly (phenylsilyleneethynylene-1,3-phenyleneethynylene) obtained in Synthesis Example 1 was added to N -Methylpyrrolidone (hereinafter referred to as NMP
To a total amount of 10 g to prepare a 14% by weight NMP solution. (Preparation of Coated Film) An n-type silicon substrate with a thermally oxidized film (one-sided mirror surface, thermally oxidized film thickness of 500 °) cut into a square of 50 mm was polished with an oxide film on the back surface, rinsed with ultrapure water, and spin-dried. . The liquid composition was fed onto the mirror surface of the silicon substrate and spin-coated so as to have a thickness of 300 nm. The conditions for forming the film are as follows: nitrogen atmosphere, rotation number: 2000
rpm, rotation start time 30 seconds, rotation hold time 360
Seconds and the rotation stop time is 10 seconds. The substrate on which the film was formed was placed in a quartz tube type infrared image furnace, and after purging with argon, heat-treated under argon gas flow to cure the film. The heat treatment conditions are: argon gas flow rate 5 cc / min, heat treatment temperature 42
0 ° C., temperature rise time 60 minutes, heat treatment temperature retention time 3
It is allowed to cool to room temperature after heat treatment for 0 minutes. (Formation of oxide film) SiO ₂ was formed on the substrate by sputtering.
A film was formed. For film formation, sputtering equipment S made by ULVAC, Inc.
BH2306RDE was used. Using an RF power source and a silicon target, reactive sputtering was performed while introducing argon and oxygen into the chamber, and a silicon oxide film was formed to a thickness of 50 nm on the wafer. The film formation conditions are as follows: ultimate vacuum degree 2 × 10 ^-7 Torr, argon gas flow rate 4 SCCM, oxygen gas flow rate 12 SCCM, sputtering vacuum degree 4 mmTorr, target output 0.6 kW, sample holder (revolving revolution) revolution speed 20 rpm, sputtering time 26.5 minutes. After film formation,
The substrate was introduced into a quartz tube type infrared image furnace, and the inside of the furnace was purged with nitrogen, and then heat-treated (annealed) under a flow of nitrogen. The heat treatment conditions are as follows: nitrogen gas flow rate 5 cc / min, heat treatment temperature 400 ° C., temperature rise time 60 minutes, heat treatment temperature hold time 2 hours, cooling to room temperature after heat treatment, temperature rise fall time 6
0 minutes. (Film Formation of Aluminum on Backside of Substrate) An aluminum film was formed on the backside of the substrate by sputtering to form ohmic contact. For the film formation, a sputtering apparatus SH450 manufactured by ULVAC, Inc. was used. Using a DC power supply and a copper target, sputtering was performed while introducing argon gas into the chamber, and aluminum was deposited on the back surface of the substrate to a thickness of 1 μm. The film formation conditions are as follows: ultimate vacuum 3 × 10
^-7 Torr, argon gas flow rate 10 SCCM, sputtering vacuum degree 3
mmTorr, DC power output 438 W, revolving speed of sample holder (self-revolution) 20 rpm, sputtering time 25 minutes. (Formation of Copper Electrode on Coating Film) On the SiO ₂ film of the substrate,
A Cu electrode was formed by sputtering. For film formation, a sputtering apparatus SBH2306RDE manufactured by ULVAC, Inc. was used.
Using a DC power supply and a copper target, sputtering was performed while introducing an argon gas into the chamber, and copper was deposited on the SiO ₂ film so as to have a thickness of 1 μm and a diameter of 1 mmφ. The film forming conditions are as follows: ultimate vacuum degree 2 × 10 ⁻⁷ Torr, argon gas flow rate 5.2 SCCM, sputtering vacuum degree 3 mmTorr, DC power output 483 W, sample holder (self-revolution) revolution speed 20 rpm, sputtering time 17.5 minutes It is. Such a structure composed of “metal-insulating film-semiconductor” is called an MIS structure. (Evaluation method of copper diffusion barrier property) Diffusion of metal ions into an insulating film is generally accelerated by applying a voltage (Biased Temperature Stress, hereinafter abbreviated as BTS treatment) under heating at about 100 to 300 ° C. . BTS impurity semiconductor substrate with MIS structure
When processed, the metal ions that make up the electrodes and the impurity metal ions in the insulating film diffuse, and when the change in capacitance with respect to the bias voltage is measured (CV measurement), the position of the flat band voltage V _FB shifts before and after the BTS process. I do. If impurity ions are not contained in the insulating film or at the interface, BTS
From the amount of change in the flat band voltage due to the processing (hereinafter abbreviated as ΔV _FB ), the ease of diffusion of Cu ions in the insulating film can be estimated. Using this method, the Cu barrier properties of some low dielectric constant insulating film materials have been evaluated (ALS L
oke, et al., Mat. Res. Soc. Symp. Proc., vol. 565,
173-187 (1999)). By this method, the Cu barrier property of the insulating film of the present invention was evaluated. (Measurement of Copper Diffusion Barrier Property) The above-mentioned substrate was mounted on a heating stage for electric measurement, and heated at 200 ° C. for 12 hours under flowing nitrogen to sufficiently remove adsorbed water. After allowing to cool to room temperature, CV measurement was performed in a nitrogen atmosphere, the temperature was raised again to 200 ° C. (heating rate 7 ° C./min), and BTS treatment was performed. CV measurement conditions are
Measurement interval 1V, measurement time 1 second, frequency 1MHz, measurement range -40V
~ + 40V. The BTS processing conditions are a heating temperature of 200 ° C., a bias voltage of +20 V, and holding for 1 hour. After allowing to cool to room temperature (temperature drop rate of 7 ° C./min), CV measurement was performed again, and ΔV _FB was calculated.

FIG. 1 shows CV curves before and after BTS processing.

[0036]

Embodiment 2 A coating solution was formed in the same manner as in Embodiment 1,
Thermal curing was performed at an argon gas flow rate of 1 L / min, a heat treatment temperature of 420 ° C., a temperature rise time of 60 minutes, and a heat treatment temperature holding time of 180 minutes. A sample having an MIS structure was formed under the same conditions as in Example 1, and electrical measurement was performed. Table 1 shows the results.

[0037]

Comparative Examples 1 to 3 As comparative examples, a BTS test was performed using a silicon oxide film and a silicon nitride film instead of the above-mentioned coating film. The silicon oxide film was formed by sputtering so as to have a thickness of 350 nm. The silicon nitride film is formed to a thickness of 300 nm by a low-temperature plasma CVD method, and then a silicon oxide film is formed by sputtering to a thickness of 50 nm.
The film was formed to have a thickness of nm. The Cu electrode and the aluminum film were formed by sputtering. The BTS conditions are the same as in Examples 1 and 2.

The results are shown in Table 1.

[0039]

[Table 1]

Table 1 shows ΔV _FB of the coating film of the present invention and, for comparison, the polyarylene ether, silicon nitride film and silicon oxide film before and after the BTS treatment. It has been found that the coating film of the present invention is an insulating barrier film superior to silicon oxide and has a copper barrier property comparable to that of silicon nitride currently used as an insulating barrier film having a dual damascene structure. did.

[Brief description of the drawings]

FIG. 1 is a CV curve (25 ° C.) of a sample of Example 2 before and after BTS treatment.
Is shown.

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Kiyotaka Shindo             580-32 Nagaura, Sodegaura-shi, Chiba Mitsui Chemicals, Inc.             In the formula company (72) Inventor Hiroko Wachi             580-32 Nagaura, Sodegaura-shi, Chiba Mitsui Chemicals, Inc.             In the formula company F term (reference) 4J035 JA00 JA04 LA00 LB20                 5F033 HH08 HH11 MM02 MM30 PP15                       QQ74 RR04 RR06 RR23 RR25                       SS08 SS15 SS22 VV10 XX24                       XX28                 5F058 AA10 AC03 AF04 AG01 AH02

Claims (8)

[Claims] 1. A metal diffusion barrier film comprising, in a repeating unit, a silicon-containing resin containing a repeating unit represented by the general formula (1) or a cured product thereof. Embedded image (Wherein, R ₁ and R ₂ are each independently a hydrogen atom, an alkyl group optionally having 1 to 30 carbon atoms, an alkenyl optionally having 1 to 30 carbon atoms, group, a alkynyl group which may have a substituent having 1 to 30 carbon atoms or a substituent, is also an aromatic group, R ₃ is -
C≡C-, -CH _2- optionally having a substituent linked to at least one -C≡C-, at least one -C≡
An alkylene group optionally having 2 to 30 carbon atoms connected to C-, an alkenylene group optionally having 2 to 30 carbon atoms connected to at least one -C≡C-, Carbon number 2 linked to at least one -C≡C-
An alkynylene group optionally having from 3 to 30 substituents, and a divalent aromatic group optionally having at least one substituent linked to -C≡C-. ) 2. The repeating unit represented by the general formula (1):
Phenylsilyleneethynylene represented by the following formula (2)
The metal diffusion barrier film according to claim 1, wherein the metal diffusion barrier film is a 1,3-phenyleneethynylene unit. Embedded image 3. The metal diffusion barrier film according to claim 1, wherein the metal diffusion barrier film is a copper diffusion barrier film. 4. A metal diffusion barrier film, comprising: applying a liquid composition containing a silicon-containing resin having a repeating unit represented by the general formula (1) in a repeating unit to a substrate, followed by heat treatment. Forming method. 5. The method according to claim 1, wherein the repeating unit represented by the general formula (1) is a phenylsilyleneethynylene-1,3-phenyleneethynylene unit represented by the general formula (2). Item 5. The method for forming a metal diffusion barrier film according to Item 4. 6. The method for forming a metal diffusion barrier film according to claim 4, wherein the heat treatment is performed at a temperature of 20 ° C. or more and 600 ° C. or less in an inert gas atmosphere or under reduced pressure. 7. The method according to claim 5, wherein the metal diffusion barrier film is a copper diffusion barrier film. 8. A semiconductor device comprising the metal diffusion barrier film according to claim 1.