JP2000103796A - Tantalum membrane-forming material, formation of tantalum membrane, and ulsi - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a Ta membrane-forming material that is useful as a chemical vapor deposition material for forming a Ta thin layer membrane of high quality by admixing a specific compound. SOLUTION: This Ta membrane-forming material includes a compound of the formula: RnTaX5-n.L (R is H, an alkyl, a halogenated alkyl or the like; (n) is 0-5; X is H, F, Cl or the like; L is an alkyl-substituted sulfur, a halogen- substituted sulfur, an alkyl-substituted phosphine or the like; (m) is 0-4 when (n) is 1-5, or 1-4 when (n) is 0) [preferably a compound of the formula: TaCl5.S (C2H5)2 or the like]. The material is applied to a base plate and decomposed by heating or the like to form the objective Ta membrane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a Ta-based film forming material, a Ta-based film forming method, and ULSI.

[0002]

At present, progress in the field of semiconductors is remarkable, and LSIs are moving to ULSIs. In order to improve the signal processing speed, miniaturization is progressing. In particular, a conductive portion (wiring) for transmitting an electric signal is required to be thin. However, when the wiring is made thinner, the electric resistance naturally becomes higher. Therefore, a wiring material having a lower resistance has been demanded. For example, it has moved from a W wiring film to an Al wiring film. And in the next generation,
Attention has been paid to Cu wiring films.

[0003] However, Cu diffuses strongly into a silicon substrate. Therefore, it is difficult to form a wiring film as it is. Therefore, a conceivable means is to provide a diffusion prevention film (barrier film) on a substrate and form a copper film thereon. Titanium nitride, tungsten nitride, tantalum nitride, and tantalum are candidates as materials for the barrier film. In particular, T such as tantalum nitride or tantalum
The a-based film has a high barrier property and is expected.

By the way, with the miniaturization of ULSI, it is required that the wiring width of copper be 0.18 μm or less. For this reason, a Ta-based film as a barrier film is required to be thin, and a chemical vapor deposition (CV)
It has become necessary to form a Ta-based film according to D). However, there are only a few reports on the formation of Ta-based films by CVD, and no satisfactory results have been obtained.

[0005] This is because there was no satisfactory CVD raw material for forming a Ta-based film. Therefore, a first problem to be solved by the present invention is to provide a Ta-based film forming material. A second problem to be solved by the present invention is:
An object of the present invention is to provide a method for forming a Ta-based film using the Ta-based film-forming material.

A third problem to be solved by the present invention is as follows.
An object of the present invention is to provide a ULSI in which a copper wiring film is formed on a Ta-based film as a barrier film formed by the above-mentioned Ta-based film forming method.

[0007]

Means for Solving the Problems The first object is solved by a Ta-based film forming material represented by the following general formula. R _n TaX _5-n · L _m [where R is H, an alkyl group, a halogenated alkyl group,
Alkene group, halogenated alkene group, alkyne group, halogenated alkyne group, aryl group, substituted aryl group, Si
Or an alkene group having Si, an alkyne group having Si, an aryl group having Si, or a substituted aryl group having Si.

[0008] n is an integer of 0-5. X is H, F, C
It is any one selected from the group of l, Br and I.
L is any one selected from the group consisting of alkyl-substituted sulfur, halogen-substituted sulfur, alkyl-substituted phosphine, and halogen-substituted phosphine. m is an integer of 0 to 4 when n is an integer of 1 to 5, and an integer of 1 to 4 when n is 0.

When n is 2 or more, all Rs in R _n may be the same or different. When n is 3 or less, all Xs in X _5-n may be the same or different. When m is 2 or more, all L in L _m
May be the same or different. ] In the present specification, the alkyl group (the n 1 or more integer) -C _n H _{2n + 1} is a group represented by. The halogenated alkyl group is a group in which one or more hydrogen atoms of the alkyl group have been substituted with a halogen atom.

[0010] alkene group is -C _n H _2n-1 group (n is an integer greater than or equal to 2) is represented by. The halogenated alkene group is a group in which one or more hydrogen atoms of the alkene group are substituted with a halogen atom. Alkyne group -C _n H
_2n-3 (n is an integer of 2 or more). The halogenated alkyne group is a group in which one or more hydrogen atoms of the alkyne group are substituted with a halogen atom.

An aryl group is an atomic group obtained by removing one hydrogen atom from an aromatic hydrocarbon. A substituted aryl group is
One or more hydrogen atoms of the aryl group may be substituted with another group (eg, an alkyl group, a halogenated alkyl group, an alkene group,
Halogenated alkene group, alkyne group, halogenated alkyne group, halogen atom, etc.). Si
, An alkene group having Si, an alkyne group having Si, an aryl group having Si, and a substituted aryl group having Si are each group (alkyl group, alkene group, alkyne group, aryl group, substituted aryl group ) Has Si.

The alkyl-substituted sulfur is, for example, R ₂ S or R
SH (R is any one selected from the group consisting of an alkyl group, an alkene group, an alkyne group, an aryl group, and a substituted aryl group). The halogen-substituted sulfur is, for example, SX ₂ or S ₂ X ₂ (X is any one selected from the group consisting of F, Cl, Br and I) or SF ₆ .

Alkyl-substituted phosphines include, for example, R
₃ P, R ₂ PH, RPH ₂ (R is any one selected from the group consisting of an alkyl group, an alkene group, an alkyne group, an aryl group, and a substituted aryl group). Halogen-substituted phosphines include, for example, PX ₃ , PX ₅ (X is F,
Cl, Br, or I).

The meaning of “when n is 2 or more, all Rs in R _n may be the same or different” means that, for example, when R ₂ , there are two Rs. However, it means that these two Rs may be the same alkyl group or different alkyl groups. The same applies to other cases. The alkyl group represented by R in the above general formula preferably has 1 to 10 carbon atoms. The alkene group represented by R preferably has 2 to 10 carbon atoms. The alkyne group represented by R preferably has 2 to 10 carbon atoms. The aryl group represented by R preferably has 6 to 20 carbon atoms. The substituted aryl group represented by R has 7 carbon atoms.
~ 20 are preferred. The alkyl group having Si represented by R preferably has 1 to 10 carbon atoms. The alkene group having Si represented by R preferably has 2 to 10 carbon atoms. The alkyne group having Si represented by R preferably has 2 to 10 carbon atoms. The aryl group having Si represented by R preferably has 6 to 20 carbon atoms. The substituted aryl group having Si represented by R has 7 to 20 carbon atoms.
Are preferred.

The Ta-based film forming material represented by the above general formula
Among them, R is -CH_Three, -CF_Three, -C_TwoH_Five, -C_Two
F_Five, -C_ThreeH₇, -C_ThreeF₇, -C_FourH₉, -C_FourF
₉, -CH = CH_TwoAnd -CH_TwoCH = CH_TwoIn the group of
Any of the Ta-based film forming materials selected from
It is. L is (CH_Three)_TwoS, (C_TwoH_Five)
_TwoS, (C_ThreeH₇)_TwoS and (C_FourH ₉)_TwoIn the group of S
Any of the Ta-based film forming materials selected from
It is.

Particularly, as a Ta-based film forming material, TaCl
_Five・ S (C_TwoH_Five)_Two, CH_ThreeTaCl_Four, (CH_Three)
_TwoTaCl_Three, (CH_Three)_ThreeTaCl_Two, CH_ThreeTaC
l_Four・ S (C_TwoH_Five)_Two, (CH_Three)_TwoTaCl_Three・ S
(C_TwoH_Five)_Two, (CH_Three) _ThreeTaCl_Two・ S (C_TwoH
_Five)_TwoIs preferred. The second problem is Ta
A method for forming a Ta-based film, comprising:
Attaching a Ta-based film on the substrate
Decomposing the forming material to form a Ta-based film.
And a method for forming a Ta-based film.
It is.

In particular, a method of forming a Ta-based film by CVD, comprising a step of decomposing the Ta-based film forming material to form a Ta-based film on a substrate. The problem is solved by a film forming method. The method for forming a Ta-based film preferably includes a step of heating the substrate on which the Ta-based film is formed.

Decomposition of the Ta-based film forming material is performed by heating.
This is performed by employing steps, light irradiation means, and plasma means.
The decomposition of the Ta-based film forming material is particularly performed in a reducing atmosphere.
Preferably. For example, hydrogen, nitrogen, ammonia,
Hydrazine, hydrazine derivative (for example, CH _ThreeNHN
H_Two, (CH_Three)_TwoNNH_Two, CH_ThreeNHNHCH_Three,
RNHNH_Two(R is a functional group such as an alkyl group)
Hydrazine derivative), silane, silane derivative (for example, R
_nSiY_4-n(R is a functional group such as an alkyl group, Y is H,
Silane derivatives such as F, Cl, Br or I)),
And borane derivatives (for example, R _nBY_3-n(R is a
A functional group such as an alkyl group, Y is H, F, Cl, Br or
One or more borane derivatives such as I)
Decomposing the Ta-based film-forming material under an airflow including
preferable.

The third problem is solved by a ULSI in which a copper wiring film is formed on a Ta-based film formed by using the above-mentioned Ta-based film forming method. In particular, the problem is solved by a ULSI in which a copper wiring film is formed on a Ta nitride-based film formed by using the above-described Ta-based film forming method.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION A Ta-based film forming material according to the present invention,
In particular, a material for forming a Ta-based film provided as a barrier film below a copper (including copper alloy) wiring film is R _n TaX
Consisting of _5-n · L _m. That is, R _n TaX _5-n · L _m
Is used to form a Ta-based film.

Here, R is H, an alkyl group, a halogenated alkyl group (an alkyl group is particularly an alkyl group having 1 to 10 carbon atoms), an alkene group, a halogenated alkene group (an alkene group is particularly a 2 to 10 alkene groups), alkyne groups, halogenated alkyne groups (alkyne groups are, in particular,
An alkyne group having 2 to 10 carbon atoms), an aryl group (particularly, an aryl group having 6 to 20 carbon atoms), a substituted aryl group (particularly,
A substituted aryl group having 7 to 20 carbon atoms, an alkyl group having Si (especially an alkyl group having 1 to 10 carbon atoms), an alkene group having Si (especially, an alkene having 2 to 10 carbon atoms) Alkyne group having Si (particularly, alkyne group having 2 to 10 carbon atoms), aryl group having Si (particularly, aryl group having 6 to 20 carbon atoms), and substituted aryl group having Si (Especially, carbon number 7
(Substituted aryl group having Si of 20 to 20).

In particular, R is -CH ₃ , -CF ₃ , -C _{2
H 5, -C 2 F 5,} -C 3 H 7, -C 3 F 7, -C 4 H
_{9, -C 4 F 9, -CH} = CH 2 and -CH ₂ CH = C
Is a group selected from the group of H _2. n is an integer of 0-5. X is any one selected from the group consisting of H, F, Cl, Br and I.

L is alkyl-substituted sulfur, halogen-substituted sulfur
Yellow, alkyl-substituted phosphines, and halogen-substituted phosphines
One of a group of dins. In particular, L
Is (CH_Three)_TwoS, (C_TwoH_Five)_TwoS, (C_ThreeH₇)
_TwoS and (C _FourH₉)_TwoA group selected from the group of S
You. m is an integer of 0 to 4 when n is an integer of 1 to 5
When n is 0, it is an integer of 1 to 4.

When n is 2 or more, all Rs in R _n may be the same or different. When n is 3 or less, all Xs in X _5-n may be the same or different. When m is 2 or more, all L in L _m
May be the same or different.

A particularly preferred Ta-based film forming material is TaC
l_Five・ S (C_TwoH_Five)_Two, CH_ThreeTaCl_Four, (C
H_Three)_TwoTaCl_Three, (CH_Three)_ThreeTaCl_Two, CH_Three
TaCl _Four・ S (C_TwoH_Five)_Two, (CH_Three)_TwoTaCl
_Three・ S (C_TwoH_Five)_Two, (CH_Three)_ThreeTaCl_Two・ S
(C_TwoH_Five)_TwoIs selected from the group of Departure
Ta-based film forming method, especially copper (including copper alloy) distribution
Forming a Ta-based film provided as a barrier film below the line film;
Is a method of forming a Ta-based film.
a process of applying an a-based film-forming material on a substrate;
The Ta-based film forming material is decomposed to form a Ta-based film.
Steps. In particular, the method of forming a Ta-based film
Heating the substrate on which the Ta-based film is formed;
Applying the Ta-based film-forming material on a substrate;
The Ta-based film-forming material attached thereon is decomposed to form a Ta-based film.
And forming a. Alternatively, T
A method for forming an a-based film, comprising:
Decomposing the material to form a Ta-based film on the substrate
I do. In particular, this is a method for forming a Ta-based film by CVD.
Heating the substrate on which the Ta-based film is formed;
The Ta-based film forming material described above is decomposed to form a Ta-based film on the substrate.
Forming step.

The decomposition of the Ta-based film forming material is performed by employing a heating means, a light irradiation means, and a plasma means. The decomposition of the Ta-based film forming material is particularly performed in a reducing atmosphere. For example, hydrogen, nitrogen, ammonia, hydrazine, hydrazine derivatives, silane, silane derivatives, borane, and under an airflow containing one or more selected from the group of borane derivatives,
The Ta-based film forming material is decomposed.

For example, a Ta-based thin film is formed on a substrate by using an apparatus as shown in FIG. That is, R _n TaX _5-n · L _m is put into the container 2 and gas is vaporized by bubbling. Vaporized raw material _{(R n TaX 5-n ·} L m) is the decomposition reactor 5 via pipe 4
Will be introduced. A silicon substrate 7 on which a film is formed is placed in the reaction furnace 5, and the silicon substrate 7 is heated by a heating unit 6. Then, the R _n TaX introduced into the reactor 5
_5-n · L _m is Ta layer is formed by decomposing near the silicon substrate 7.

The ULSI according to the present invention is a ULSI in which a copper wiring film is formed on a Ta-based film formed by using the Ta-based film forming method. Particularly, it is an ULSI in which a copper wiring film is formed on a Ta nitride-based film formed by using the above-described Ta-based film forming method. Hereinafter, some specific examples will be described, but the present invention is not limited thereto.

[0029]

[Embodiment 1] T using TaCl ₅ .S (C ₂ H ₅ ) ₂
a film was formed. That is, TaCl ₅ .S (C
₂ H ₅ ) ₂ was placed in the container 2, and He was vaporized by bubbling He as a carrier gas at a flow rate of 100 ml / min. At this time, the temperature of the container 2 was controlled at 40 ° C.

The vaporized TaCl ₅ .S (C ₂ H ₅ ) ₂ was introduced into the decomposition reactor 5 through the pipe 4. Decomposition reactor 5
Contains a silicon substrate 7, which is heated to 500 ° C. Also, hydrogen gas is flowing.

A thin film was formed on the silicon substrate 7 as described above. This thin film has a thickness of 0.1 μm,
As a result of elemental analysis, the main component was Ta.

[0032]

Example 2 A Ta film was formed using CH ₃ TaCl ₄ . That is, CH ₃ TaCl ₄ was placed in the container 2, and He was flowed as a carrier gas at a flow rate of 30 ml / min to sublime. At this time, the temperature of the container 2 was controlled at 25 ° C. The vaporized CH ₃ TaCl ₄ was introduced into a decomposition reaction furnace 5 through a pipe 4.

A silicon substrate 7 is placed in the decomposition reaction furnace 5, and the silicon substrate 7 is heated to 400.degree. Also, hydrogen gas is flowing. A thin film was formed on the silicon substrate 7 as described above. This thin film had a thickness of 0.1 μm, and as a result of elemental analysis, was mainly composed of Ta.

[0034]

Example 3 A Ta film was formed using CH ₃ TaCl ₄ .S (C ₂ H ₅ ) ₂ . That is, CH ₃ TaCl _4.
S (C ₂ H ₅ ) ₂ was put into the container 2, and He was vaporized by flowing He as a carrier gas at a flow rate of 30 ml / min. At this time, the temperature of the container 2 was controlled at 20 ° C.

The vaporized CH ₃ TaCl ₄ .S (C
₂ H ₅ ) ₂ was introduced into a decomposition reaction furnace 5 through a pipe 4.
A silicon substrate 7 is placed in the decomposition reaction furnace 5, and the silicon substrate 7 is heated to 400 ° C. Also, hydrogen gas is flowing.

A thin film was formed on the silicon substrate 7 as described above. This thin film has a thickness of 0.1 μm,
As a result of elemental analysis, the main component was Ta.

[0037]

Embodiment 4 Using TaCl ₅ .S (C ₂ H ₅ ) ₂ for T
An a-based film was formed. That is, TaCl ₅ .S (C ₂ H
₅ ) ₂ was placed in the container 2, and He was vaporized by bubbling He as a carrier gas at a flow rate of 100 ml / min. At this time, the temperature of the container 2 was controlled at 40 ° C.

The vaporized TaCl ₅ .S (C ₂ H ₅ ) ₂ was introduced into the decomposition reactor 5 through the pipe 4. Decomposition reactor 5
Contains a silicon substrate 7, which is heated to 500 ° C. A mixed gas of hydrogen, ammonia, and monomethylhydrazine is flowing.

A thin film was formed on the silicon substrate 7 as described above. This thin film had a thickness of 0.05 μm, and as a result of elemental analysis, was mainly composed of Ta and N.

[0040]

Fifth Embodiment A silicon substrate provided with a thin film containing Ta and N as main components prepared in a fourth embodiment was heated to 200.degree. Then, hexafluoroacetylacetone copper trimethylvinylsilane (HfacC) is added to the silicon substrate system.
u: TMVS) in a heptadecane solution (1 mol / l).

After heating for 1 minute, the solution was cooled, the solution was poured out, and the inside of the container was washed three times with normal hexane, and then the silicon substrate was taken out. The thin film mainly composed of Ta and N formed on the silicon substrate in Example 4 exhibited silver luster. However, after passing through this example, it was changed to copper red gold luster. .

When the cross section of the silicon substrate was observed with an electron microscope, a deposit was observed to a depth of 0.9 μm from the surface. Subsequently, the deposit was subjected to elemental analysis. As a result, the deposit up to a depth of 0.9 μm from the surface was a film mainly composed of copper, Ta and N, and pure silicon under the film mainly composed of Ta and N. This result indicates that copper has not diffused into the silicon substrate.

[0043]

Comparative Example 1 A silicon substrate was heated to 200.degree. Then, a heptadecane solution of hexafluoroacetylacetone copper trimethylvinylsilane (1 mol / l) was poured into the silicon substrate system. After heating for 1 minute, the solution was cooled, and the solution was poured out.
After washing twice, the silicon substrate was taken out.

The surface of the silicon substrate was changed to a copper-gold lustrous one. When the cross section of the silicon substrate was observed with an electron microscope, a deposit was observed to a depth of 0.9 μm from the surface. Subsequently, the deposit was subjected to elemental analysis. As a result, the deposit up to a depth of 0.9 μm from the surface was copper, but copper-silicon up to a depth of 2.2 μm therefrom was silicon, and the silicon under the deposit. This result indicates that copper is diffused into the silicon substrate.

[0045]

Example 6 A copper thin film was formed on the silicon substrate provided with a thin film containing Ta and N as main components prepared in Example 4 by using hexafluoroacetylacetone copper trimethylvinylsilane as a vaporizing material. When a cross section of the silicon substrate was observed with an electron microscope, a deposit was observed to a depth of 0.5 μm from the surface.

Subsequently, the deposit was subjected to elemental analysis. As a result, the deposit up to a depth of 0.5 μm from the surface was a film mainly composed of copper, Ta and N, and pure silicon under the film mainly composed of Ta and N. This result indicates that copper has not diffused into the silicon substrate.

[0047]

Comparative Example 2 A thin copper film was formed on a silicon substrate by CVD using hexafluoroacetylacetone copper trimethylvinylsilane as a vaporizing material. When a cross section of the silicon substrate was observed with an electron microscope, a deposit was observed to a depth of 0.5 μm from the surface.

Subsequently, the deposit was subjected to elemental analysis. As a result, the deposit up to a depth of 0.5 μm from the surface is copper, and the deposit up to a depth of 1.9 μm is copper-silicon,
Below that was silicon. This result indicates that copper is diffused into the silicon substrate.

[0049]

As described above, a high-quality Ta-based thin film can be formed. When the Ta-based thin film is provided, even if a copper film is provided thereon, copper does not diffuse into the substrate, and a high barrier function is achieved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a Ta-based film forming apparatus.

[Explanation of symbols]

_{1 R n TaX 5-n ·} L m (Ta -based film-forming material) 2 vessel 3 flow controller 4 pipe 5 decomposition reactor 6 the heating means 7 silicon substrate

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/285 301 H01L 21/285 301R 21/3205 21/88 M (72) Inventor Hiroshi Sudo Kitatsuru, Yamanashi 8154-217, Uenohara, Uenohara-gun, Gunma Tri-Chemical Research Institute, Inc. (72) Inventor Yoshie Suzuki 8154-217, Uenohara, Uenohara-cho, Kitatsuru-gun, Yamanashi Pref. 8154-217 Trichemical Laboratory Co., Ltd.F-term (reference) 5F033 HH11 HH21 HH32 PP06 PP10 PP12

Claims (16)

[Claims] 1. A Ta-based film forming material represented by the following general formula: R _n TaX _5-n · L _m [where R is H, an alkyl group, a halogenated alkyl group,
Alkene group, halogenated alkene group, alkyne group, halogenated alkyne group, aryl group, substituted aryl group, Si
Or an alkene group having Si, an alkyne group having Si, an aryl group having Si, or a substituted aryl group having Si. n
Is an integer of 0 to 5. X is H, F, Cl, Br and I
Is any one selected from the group of L is alkyl-substituted sulfur, halogen-substituted sulfur, alkyl-substituted phosphine,
And halogen-substituted phosphines. m is an integer of 0 to 4 when n is an integer of 1 to 5, and an integer of 1 to 4 when n is 0. When n is 2 or more, all R in R _n may be the same or different. When n is 3 or less, all Xs in X _5-n may be the same or different. When m is 2 or more, all L in L _m may be the same or different. ] 2. R is —CH ₃ , —CF ₃ , —C ₂ H ₅ ,
_{-C 2 F 5, -C 3 H} 7, -C 3 F 7, -C 4 H 9, -
C ₄ F _9, Ta-based film-forming material according to claim 1, characterized in that at any one selected from the group of -CH = CH ₂ and -CH ₂ CH = CH _2. 3. L is (CH ₃ ) ₂ S, (C ₂ H ₅ )
_{2. The} material according to claim 1, wherein the material is selected from the group consisting of ₂ S, (C ₃ H ₇ ) ₂ S and (C ₄ H ₉ ) ₂ S.
Or the Ta-based film forming material according to claim 2. 4. A Ta-based film forming material comprising TaCl ₅ .S (C ₂ H ₅ ) ₂ . 5. CH ₃ TaCl ₄ , (CH ₃ ) ₂ TaC
A Ta-based film forming material comprising l ₃ and / or (CH ₃ ) ₃ TaCl ₂ . 6. CH ₃ TaCl ₄ .S (C ₂ H ₅ ) ₂ ,
T composed of (CH ₃ ) ₂ TaCl ₃ .S (C ₂ H ₅ ) ₂ and / or (CH ₃ ) ₃ TaCl ₂ .S (C ₂ H ₅ ) ₂
a-based film forming material. 7. A method for forming a Ta-based film, comprising: applying the Ta-based film-forming material according to claim 1 on a substrate; and the Ta-based film-forming material attached to the substrate. Decomposing to form a Ta-based film. 8. T by chemical vapor deposition
A method for forming an a-based film, comprising the step of decomposing a Ta-based film forming material according to any one of claims 1 to 6 to form a Ta-based film on a substrate. -Based film forming method. 9. The method for forming a Ta-based film according to claim 7, further comprising a step of heating a substrate on which the Ta-based film is formed. 10. The method according to claim 7, wherein the decomposition of the Ta-based film forming material is performed by heating.
a-based film forming method. 11. The Ta-based film forming material according to claim 7, wherein the Ta-based film forming material is decomposed by light.
-Based film forming method. 12. The Ta-based film forming method according to claim 7, wherein the Ta-based film forming material is decomposed by plasma. 13. The Ta-based film forming method according to claim 7, wherein the decomposition of the Ta-based film forming material is performed in a reducing atmosphere. 14. A Ta-based film-forming material is decomposed under an air current containing at least one selected from the group consisting of hydrogen, nitrogen, ammonia, hydrazine, hydrazine derivatives, silane, silane derivatives, borane, and borane derivatives. 14. The method for forming a Ta-based film according to claim 7, wherein: 15. The Ta according to any one of claims 7 to 14,
ULSI in which a copper wiring film is formed on a Ta-based film formed by using a system film forming method. 16. Ta according to any one of claims 7 to 14,
ULSI in which a copper wiring film is formed on a Ta nitride-based film formed by using a base film forming method.