JP2001335530A - Organocopper complex - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organocopper complex having a melting point of <=30 deg.C, excellent in thermal stability when vaporized and suitable for depositing copper thin film by a CVD method. SOLUTION: This organocopper complex is shown by the general formula (I) (wherein, R1 and R2 are each a 1-8C alkyl or 1-8C perfluoroalkyl; R3 is H, F or a 1-8C perfluoroalkyl; and R4 to R7 are such that at least one of them is a 2-8C alkenyl, the other being H atom(s) or 1-8C alkyl group(s)).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic copper complex used as a copper source when a copper thin film such as a semiconductor wiring is formed by metal organic chemical vapor deposition (hereinafter referred to as CVD).

[0002]

2. Description of the Related Art As a raw material for forming a copper thin film by a CVD method, a (vinyltrimethylsilane) (hexafluoroacetylacetonato) copper (I) complex represented by the following formula (II) [hereinafter, Cu (hfac) (tmvs)] Is well known (Japanese Patent Laid-Open No. 5-59551).

[0003]

Embedded image Also, US Pat. No. 5,994,571 discloses the following formula (I
An organic copper complex having 2-methyl-1-butene of an ethylene derivative represented by II) as a ligand is shown.

[0004]

Embedded image

[0005]

The above formulas (II) and (II)
When the olefin ligand coordinated to copper is a monoolefin as in the organic copper complex represented by I), that is, when the group attached to the double bond is an H atom, an alkyl group, or a silyl group. When it is a group, the organic copper complex has a problem of low thermal stability. For example, the organocopper complex represented by the formula (III) has low thermal stability such that decomposition occurs gradually at room temperature even under reduced pressure. Formula (II) having a silyl group
Although the organic copper complex of the above improves the thermal stability, there is a problem that the decomposition reaction gradually occurs in the vaporization vessel with respect to the heating temperature at the time of vaporization.

On the other hand, as a ligand having two double bonds, that is, as a diene compound, a copper complex using a cyclic hydrocarbon diene compound such as 1,5-cyclooctadiene or norbornadiene is used. (Organometallics 1985, vol. 4, 830)
page). However, all of these diene copper complexes were solid at room temperature, and were not suitable as materials for CVD. An object of the present invention is to provide an organocopper complex having a melting point of 30 ° C. or less and having excellent thermal stability during vaporization and suitable for forming a copper thin film by a CVD method.

[0007]

Means for Solving the Problems The present inventors have conducted research to find an organic copper complex having better stability, and as a result,
The present inventors have found that a compound having a copper complex having a chain diene compound as a ligand is liquid at room temperature and has high thermal stability, and thus completed the present invention. That is, the present invention relates to an organic copper complex represented by the general formula (I) (wherein R ¹ and R ² are an alkyl group having 1 to 8 carbon atoms or a perfluoroalkyl group having 1 to 8 carbon atoms, R ³ Is a H, F atom or a perfluoroalkyl group having 1 to 8 carbon atoms, and R ^{4 to} R ⁷ are at least one of them is an alkenyl group having 2 to 8 carbon atoms, and the others are H atoms or carbon atoms. 1-8 atoms
Represents an alkyl group. ).

[0008]

Embedded image

The organocopper complex of the present invention is a compound wherein the olefin ligand coordinated to copper has at least one other double bond in addition to the double bond coordinated to copper. .
For example, in the general formula (I), R ¹ and R ² are CF ₃ groups, R ³ is an H atom, R ⁴ and R ⁵ are H atoms, and R ⁶ is CH ₃
An organic copper complex having 2-methyl-1,5-heptadiene (cis, trans mixture) in which R ⁷ is CH ₃ —CH ＝ CH—CH ₂ —CH ₂ — as one of the ligands [formula (IV)] is one example.

[0010]

Embedded image

A copper complex having this 2-methyl-1,5-heptadiene as a ligand, (2-methyl-1,5-heptadiene) (1,1,1,5,5,5-hexafluoro-
2,4-pentanedionato) copper (I) [hereinafter referred to as Cu (h
fac) (mhd)] is a yellow liquid near room temperature and exhibits excellent thermal stability. This organic copper complex is a novel substance.

As another example, R ¹ and R ² are CF ₃ groups, R ³ is H, R ⁴ , R ⁵ and R ⁶ are H atoms, and R ⁷
Is CH ₃ —CH ＝ CH—CH ₂ —CH ₂ —
An organic copper complex [formula (V)] having heptadiene (a mixture of cis and trans) as one of the ligands can be given.

[0013]

Embedded image

A copper complex having this 1,5-heptadiene as one of the ligands (1,5-heptadiene) (1,
1,1,5,5,5-hexafluoro-2,4-pentanedionato) copper (I) [hereinafter, Cu (hfac) (h
d) is a yellow liquid near room temperature and exhibits excellent thermal stability. This complex is a novel substance.

Since the organocopper complex of the present invention exists in a liquid state at around room temperature, a known CVD method using a liquid raw material is used.
Law is applicable. For example, a vaporization method using carrier gas bubbling can be used to supply the deposition material. At this time, heating at about 80 ° C. is also possible because of excellent thermal stability. Also, a known CVD method can be used for vapor deposition on the substrate, but it goes without saying that the vapor deposition conditions need to be appropriately changed according to changes in the substrate type, equipment, etc., as in the known method.

[0016]

The organocopper complex of the present invention can be synthesized by reacting copper (I) oxide, a diene compound and a β-diketone compound. The product can be easily purified by conventional column chromatography. Hereinafter, the present invention will be described in more detail with reference to specific examples.

Embodiment 1 In this embodiment, Cu (hfac) (mh) represented by the formula (IV)
d) That is, in the general formula (I), R ¹ and R ² are a CF ₃ group, R ³ is an H atom, and R ⁴ and R ⁵ are H atoms, R ⁶
Is a CH ₃ — group, and R ⁷ is CH ₃ —CH ＝ CH—CH ₂ —CH
An example of the synthesis of an organic copper complex of _2- will be described. All reactions are performed under an argon atmosphere. 100cc replaced with argon
40 ml of dry hexane was put into a two-necked flask, and 2.86 g (20.0 mmol) of copper (I) oxide was suspended therein. After adding 2.20 g (20.0 mmol) of 2-methyl-1,5-heptadiene to the suspension and stirring for 30 minutes at room temperature, 1,1,1,5,5,5-hexafluoro-2 was added. , 4-pentanedione 4.16 g (20.0 m
mol) was added dropwise. After completion of the dropwise addition, the mixture was reacted by stirring at room temperature for 2 hours, and unreacted copper oxide was filtered off under argon to obtain a yellow solution. By concentrating this solution,
The crude compound was obtained as a yellow liquid. The crude product is subjected to column chromatography using silica gel as a filler under an argon atmosphere to obtain the desired Cu (hfac) (mh
4.53 g (11.9 mmol, 60% yield) of d) were obtained. This compound is a yellow liquid at room temperature.

The identification of the organocopper compound was performed by NMR and elemental analysis. 1H-NMR (CDCl ₃ ): δ 1.60-1.62
(D 3H), 1.83 (s 3H), 2.28-2.3
0 (m4H), 4.51 (m2H), 5.36-
5.45 (m 2H), 5.95 ( br 1H) · Elemental _{analysis: C 13 H 15 F 6 O} 2 Cu measurement C: 40.0%, H: 3.70 %, Cu: 17% theory C: 41.0%, H: 3.97%, Cu: 16.7% Melting point: 25 ° C

This organocopper complex was sealed in a glass ampule tube under reduced pressure, and heated at 80 ° C. for 1 hour. As a result, it remained a yellow liquid, and no deterioration was visually observed.

Example 2 Here, Cu (hfac) (hd), that is, in the general formula (I), R ¹ and R ² are a CF ₃ group, R ³ is an H atom, and R ⁴ and R ⁵ , R ⁶ is an H atom and R ⁷ is CH ₃ —
An example of a copper complex is a _{- CH = CH-CH 2 -CH} 2.
1,5- instead of 2-methyl-1,5-heptadiene
Except that 1.92 g (20.0 mmol) of heptadiene was used, the same procedure as in Example 1 was carried out to obtain 4.62 g of the target compound.
(12.6 mmol, 63% yield) was obtained. This compound was a yellow liquid at room temperature.

The identification of the organocopper complex was performed by NMR and elemental analysis. 1 H-NMR (CDCl ₃ ): δ 1.68-1.75
(M3H), 2.28-2.35 (m4H), 4.4
2-4.52 (m2H), 5.18-5.41 (m3
H), 6.06 (br 1H) Elemental analysis: C ₁₂ H ₁₃ F ₆ O ₂ Cu Measurement C: 38.0%, H: 3.01%, Cu: 18% Theoretical C: 39.3 %, H: 3.57%, Cu: 17.3% Melting point: 25 ° C

This Cu (hfac) (hd) complex was also sealed in a glass ampule under reduced pressure, and
C. for 1 hour, the Cu (hfa
c) Like the (mhd) complex, it remained in a yellow liquid state, and no visual deterioration was confirmed.

Comparative Examples 1 to 3 Here are examples of copper complexes containing a monoolefin as one of the ligands. Instead of 2-methyl-1,5-heptadiene, vinyltrimethylsilane, 2-methyl-1-
A copper complex was synthesized in the same manner as in Example 1 except that butene and 2-methyl-1-heptene were used. 2-methyl-1-butene should give a conventionally known copper complex represented by the formula (III), and the copper complex containing 2-methyl-1-heptene as one of the ligands is described below. After the reaction, the solution obtained by column chromatography, which is a conventional method, was concentrated under reduced pressure at room temperature under an argon atmosphere, and in each case, the color changed from yellow to brown to black-brown, and decomposition had already occurred at room temperature. It is confirmed that.

Vinyl trimethylsilane is a compound of the formula (II), which is a well-known organic copper complex Cu (hfa
c) Give (tmvs). This complex is 2-methyl-1
-Butene, unlike a complex having 2-methyl-1-heptene as one of the ligands, is stable enough to be isolated,
When sealed in a glass ampule tube under reduced pressure and heated at 80 ° C, the color changes from yellow to black after 2 to 3 minutes, and copper deposition is observed on the glass wall, and decomposition has occurred. Is confirmed.

That is, any of the organocopper complexes of the present invention containing a diene as one of the ligands has the formula (II) or (III)
It has been confirmed that, compared to the conventionally known organocopper complex containing a monoene as one of the ligands, it shows better stability against heating during vaporization.

[0026]

Since the organocopper complex of the present invention has a sufficiently low melting point and excellent thermal stability, it is possible to supply a raw material with little change over time in the CVD method. That is, it can be effectively used for manufacturing a copper thin film requiring uniformity such as a semiconductor wiring material.

Claims (4)

[Claims] 1. A compound represented by the following general formula (I) (Wherein R ¹ and R ^{2 each} have 1 to 1 carbon atoms)
An alkyl group having 8 carbon atoms or a perfluoroalkyl group having 1 to 8 carbon atoms, R ³ represents an H, F atom or 1 carbon atom;
And at least one of R ^{4 to} R ⁷ represents an alkenyl group having 2 to 8 carbon atoms, and the other represents an H atom or an alkyl group having 1 to 8 carbon atoms. ). 2. R ¹ and R ² are a CF ₃ group, and
The organic copper complex according to claim 1, wherein R ³ is an H atom. 3. R ⁴ and R ⁵ are H atoms, R ⁶ is a CH ₃ group, and R ⁷ is CH ₃ —CH ＝ CH—CH ₂ —CH ₂ —,
The organic copper complex according to claim 1. 4. R ⁴ , R ⁵ and R ⁶ are H atoms, and
The organocopper complex according to claim 1, wherein R ⁷ is CH ₃ —CH ＝ CH—CH ₂ —CH ₂ —.