JP2003257889A - SOLUTION MATERIAL FOR METAL-ORGANIC CHEMICAL VAPOR DEPOSITION CONTAINING beta-DIKETONATE COMPLEX OF COPPER (II) AND COPPER THIN FILM FORMED USING THE SAME - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To supply a material stably at the time of film deposition and to obtain a high purity copper thin film exhibiting excellent thermal stability in which the lifetime is prolonged by retarding decomposition under preservation state, and to obtain an MOCVD process in which an MOCVD system is not corroded easily, treatment of exhaust gas is not complicated and adhesion to an underlying film is enhanced. <P>SOLUTION: In the solution material for metal-organic CVD produced by dissolving β-diketonate complex of copper (II) in an organic solvent, the organic solvent is one kind or more than one kind of compound selected from a group of n-methyl-2-pyrrolidone, dimethylaniline, di-t-butylaniline, di-n-butylaniline, diisopropylaniline, tri-t-butylaniline, and triisopropylaniline. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a copper (Cu) thin film used for wiring of a semiconductor device by metalorganic chemical vapor deposition (Meta
l Organic Chemical Vapor Deposition, MOC
It is called VD. And a copper (II) β-diketonate complex-containing solution raw material for the MOCVD method and a copper thin film produced using the same.

[0002]

2. Description of the Related Art Copper and copper-based alloys are used as wiring materials for LSIs because of their high conductivity and resistance to electromigration. Moreover, the composite metal oxide containing copper is applied as a functional ceramic material such as a high temperature superconductor. As a method for producing a copper-based thin film such as copper, an alloy containing copper, and a complex metal oxide containing copper, a sputtering method, an ion plating method, a coating pyrolysis method, or the like can be given; Accordingly, the CVD method and the MOCVD method using an organometallic compound have been studied as the optimum thin film manufacturing processes because of their excellent composition controllability, step coverage, step embedding properties, compatibility with LSI processes, and the like.

As the organic copper compound for imparting copper to the IC substrate and the surface by the MOCVD method, Cu has hitherto been used.
The (II) (hfac) ₂ complex or copper (II) hexafluoroacetylacetonate complex has been used. But this C
The u (II) (hfac) ₂ complex is not practical because it leaves contaminants in the deposited copper and requires the use of relatively high temperatures to decompose the complex to form copper. It did not have such characteristics.

Therefore, the use of a monovalent Cu (I) (hfac) complex has been studied. For example, Cu (I) which is liquid at room temperature is investigated.
A tmvs.hfac complex, a copper (I) hexafluoroacetylacetonate trimethylvinylsilane complex, has been disclosed (US Pat. No. 5,322,712). This C
The u (I) tmvs.hfac complex has a relatively low temperature of about 2
It is very useful because it can be used at 00 ° C.
However, this complex is very expensive, and is extremely unstable in the atmosphere, so that it lacks in stability, easily decomposes at room temperature, precipitates metallic copper and produces a by-product Cu (II) (hfac) ₂ Changes significantly and the deterioration is remarkable. Therefore, it is difficult to stably supply this copper complex during film formation, and the reproducibility of film formation is poor. Further, since the ligand hfac contains fluorine (F), the MOCVD apparatus is easily corroded, and the exhaust gas treatment in the MOCVD process is complicated. Further, when a copper film is formed by MOCVD using an organocopper compound containing fluorine such as hfac, when a desired copper thin film is formed, not only fluorine is taken into the copper thin film as an impurity, but also There is a problem that fluorine remains on the underlayer interface of the wafer and the adhesion with the underlayer is reduced.

In order to solve the above-mentioned problems, a raw material for chemical vapor deposition comprising a β-diketonate complex of copper (II) represented by the following formula (8) is disclosed (JP-A-200).
1-181840).

[0006]

[Chemical 8] (In the formula, R represents an isopropyl group or a tert-butyl group,
R ¹ represents a methyl group or an ethyl group, and R ² represents a propyl group or a butyl group. ) Since this copper raw material is a liquid at room temperature and does not contain elements such as halogen element and nitrogen element which are considered to have an influence on thin film production in the molecule, it is suitable for various CVD methods.
It has the same thermal and chemical stability as the existing copper raw material for CVD consisting of a solid copper (II) complex.

[0007]

However, Japanese Patent Laid-Open No. 2001-2001
The copper raw material represented by the above-mentioned formula (8) of 181840 gazette is a liquid at normal temperature, but its viscosity is very high, and it is necessary to supply this copper raw material at a high pressure to supply it to the MOCVD apparatus. There was a problem with the film properties. Even if this copper raw material is dissolved in a solution and supplied as a solution raw material to a MOCVD apparatus, the decomposition temperature of this copper raw material is about 450 ° C.,
Since the decomposition temperature of an organic copper compound which has been generally used conventionally is extremely high, there is a problem that it is difficult to form a film.
Further, since the copper raw material represented by the above formula (8) has an unbalanced structure in which the molecular structure is extremely biased, it is difficult to stably supply the raw material during film formation, and sufficient film formation stability is obtained. It could not be said that the sex was obtained.

The object of the present invention is to provide a stable supply of raw materials during film formation, and to obtain a high-purity copper thin film.
It is intended to provide a solution raw material for a metalorganic chemical vapor deposition method containing a diketonate complex. Another object of the present invention is excellent thermal stability, β (2) of copper (II) which is hard to decompose in storage and has a long life.
-To provide a solution raw material for a metalorganic chemical vapor deposition method containing a diketonate complex. Another object of the invention is the MOC.
It is an object of the present invention to provide a solution raw material for a metal organic chemical vapor deposition method containing a copper (II) β-diketonate complex which does not easily corrode a VD device and does not complicate exhaust gas treatment in a MOCVD process. Still another object of the present invention is to provide a high-purity copper thin film that firmly adheres to a base film.

[0009]

The invention according to claim 1 is
A solution raw material for a metal organic chemical vapor deposition method in which a β-diketonate complex of copper (II) is dissolved in an organic solvent, wherein the organic solvent is an amine solvent. In the invention according to claim 1, by using a solution raw material for MOCVD using an amine-based solvent as an organic solvent, a stable raw material can be supplied at the time of film formation. Due to the high reducibility of the system solvent, a high purity copper thin film can be obtained.

The invention according to claim 2 is the invention according to claim 1, wherein the amine solvent is n-methyl-2-pyrrolidone, dimethylaniline (hereinafter referred to as DMA), and di-.
t-butylaniline (hereinafter referred to as DTBA), di-n
-Butylaniline (hereinafter referred to as DNBA), diisopropylaniline (hereinafter referred to as DIPA), tri-
A solution raw material which is one or more compounds selected from the group consisting of t-butylaniline (hereinafter referred to as TTBA) and triisopropylaniline (hereinafter referred to as TIPA). The invention according to claim 3 is the invention according to claim 1, wherein the β-diketonate complex of copper (II) is a solution raw material represented by the following formula (1).

[0011]

[Chemical 9] However, R is an isopropyl group.

In the invention according to claim 3, a copper complex in which a ligand having an isopropyl group is coordinated to two atomic groups branched from the basic skeleton (hereinafter referred to as Cu (II) (DMH)
D) ₂ ) Has high structural stability, and a solution raw material obtained by dissolving this copper complex in an amine solvent is excellent in long-term storage.

The invention according to claim 4 is the invention according to claim 1, wherein the β-diketonate complex of copper (II) is a solution raw material represented by the following formula (2).

[0014]

[Chemical 10] Provided that R ₁ and R ′ ₁ are each an ethyl group, R ₂ and R ′ ₂ are each an isopropyl group, or R ′ ₁ and R ₂ are an isopropyl group, and R ₁ and R ′ ₂ Are each an ethyl group, or R ₁ and R ′ ₁ are each a methyl group, R ₂ and R ′ ₂ are each an n-butyl group, or R ′ ₁ and R ₂ are each an n- It is a butyl group, and R ₁ and R ′ ₂ are each a methyl group.

The invention according to claim 5 is the invention according to claim 4, wherein the β-diketonate complex of copper (II) is a compound represented by the following formula (3) and a compound represented by the following formula (4): It is a solution raw material which is a mixture of the compounds shown.

[0016]

[Chemical 11] However, R ₃ and R ′ ₃ are each an ethyl group, and R ₄ and R ′ ₄ are each an isopropyl group.

[0017]

[Chemical 12] However, R ′ ₅ and R ₆ are isopropyl groups, and R ₅ and R ′ ₆ are ethyl groups, respectively.

The invention according to claim 6 is the invention according to claim 4, wherein the β-diketonate complex of copper (II) is a compound represented by the following formula (5) and a compound represented by the following formula (6): It is a solution raw material which is a mixture of the compounds shown.

[0019]

[Chemical 13] However, R ₇ and R ′ ₇ are each a methyl group, and R ₈ and R ′ ₈ are each an n-butyl group.

[0020]

[Chemical 14] Provided that R ′ ₉ and R ₁₀ are each an n-butyl group,
₉ and R _'10 are each a methyl group.

In the invention according to any one of claims 4 to 6, a copper complex (hereinafter referred to as Cu (II) ) (EP) ₂ ) or a copper complex coordinated with a ligand forming a methyl group or an n-butyl group (hereinafter referred to as Cu (II) (OD) ₂ ) is an electron on a copper atom. Since the density is richly replenished and the multimerization due to the interaction of the internal structure with other compounds, which is basically a problem, is suppressed, the structural stability is high, and this copper complex is a solution raw material in which this copper complex is dissolved in an amine solvent. Is excellent for long-term storage.

The invention according to claim 7 is the invention according to claim 1, wherein the β-diketonate complex of copper (II) is a solution raw material represented by the following formula (7).

[0023]

[Chemical 15] However, R ₁ is an isopropyl group and R ₂ is an ethyl group.

In the invention according to claim 7, a copper complex in which a ligand having an ethyl group and a ligand having an isopropyl group are respectively coordinated to two atomic groups branched from the basic skeleton (hereinafter , Cu (II) (EIP) ₂ ) is richly replenished with electron density on the copper atom, and basically suppresses multimerization due to interaction between other compounds and internal structure, which is a problem. The structural stability is high, and the solution raw material in which this copper complex is dissolved in an organic solvent is excellent in long-term storage.

The invention according to claim 8 relates to claims 1 to 7.
It is a copper thin film produced by a metal organic chemical vapor deposition method using any of the solution raw materials. The copper thin film produced by using the solution raw material according to any one of claims 1 to 7 can firmly adhere to the base film due to the high reducing property of the amine solvent, and since the solution raw material does not contain fluorine. A high-purity film that is difficult to peel off.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described. The solution raw material of the present invention is an improvement of the solution raw material for MOCVD in which a β-diketonate complex of copper (II) is dissolved in an organic solvent, and a characteristic feature thereof is that the organic solvent is an amine solvent. The compounding ratio of the copper (II) β-diketonate complex and the amine solvent is arbitrary, and it is preferable to appropriately prepare the compound according to the intended use and the type of the amine solvent. The solution raw material of the present invention includes n-methyl-2-pyrrolidone, DMA, DTBA, DNBA, DIPA, TTB.
One or more compounds selected from the group consisting of A and TIPA are used as the amine solvent.

The β-diketonate complex of copper (II) is a Cu (II) (DMHD) ₂ complex represented by the above-mentioned formula (1), and Cu (II) (EP) having the above-mentioned formula (2) as a general formula. ₂ complex, Cu
(II) (OD) ₂ complex, Cu (I) represented by the above formula (7)
I) (EIP) ₂ complex. Among the complexes having the general formula (2), the Cu (II) (EP) ₂ complex has the following formula (9):
A complex represented by Formula (10), a complex represented by Formula (10),
A mixture of the complex represented by and the complex represented by the formula (10) can be mentioned. The Cu (II) (OD) ₂ complex has the following formula (1
Examples thereof include the complex represented by 1), the complex represented by the formula (12), and a mixture of the complex represented by the formula (11) and the complex represented by the formula (12). The Cu (II) (EP) ₂ complexes represented by the formulas (9) and (10) have a relationship of ligand isomerism, and Cu (II) represented by the formulas (11) and (12), respectively. ) (OD) ₂ complex also has a relationship of ligand isomerism.

[0028]

[Chemical 16]

[0029]

[Chemical 17]

[0030]

[Chemical 18]

[0031]

[Chemical 19]

The solution raw material of the present invention can be used as a solution raw material having higher storage stability by further containing a stabilizer. As the stabilizer, one or more compounds selected from the group consisting of ethylene glycol ethers, crown ethers, polyamines, cyclic polyamines, β-ketoesters and β-diketones are used. Specifically, the ethylene glycol ethers include one or two selected from the group consisting of glyme, diglyme, triglyme and tetraglyme.
One or more compounds may be mentioned. Crown ethers include 18-crown-6, dicyclohexyl-18-crown-6, 24-crown-8, dicyclohexyl-24-
One or more compounds selected from the group consisting of crown-8 and dibenzo-24-crown-8 can be mentioned.
Polyamines include ethylenediamine, N, N'-tetramethylmethylenediamine, diethylenetriamine,
Trimethylenetetramine, tetraethylenepentamine,
Pentaethylenehexamine, 1,1,4,7,7-pentamethyldiethylenetriamine and 1,1,4,7,10,10-
One or more compounds selected from the group consisting of hexamethyltriethylenetetramine may be mentioned. Examples of the cyclic polyamines include one or two compounds selected from the group consisting of cyclam and cyclen.
Examples of β-ketoesters or β-diketones include one or more compounds selected from the group consisting of methyl acetoacetate, ethyl acetoacetate and 2-methoxyethyl acetoacetate.

In the present embodiment, the MOCVD method uses a solution vaporization CVD method in which each solution is supplied to a heated vaporizer, where each solution raw material is instantly vaporized and sent to the film forming chamber. As shown in FIG. 1, the MOCVD apparatus includes a film forming chamber 10
And a steam generator 11. A heater 12 is provided inside the film forming chamber 10, and a substrate 13 is held on the heater 12. The inside of the film forming chamber 10 is evacuated by a pipe 17 including a pressure sensor 14, a cold trap 15 and a needle valve 16. The steam generator 11 includes a raw material container 18, and the raw material container 18 stores a solution raw material. A carrier gas introduction pipe 21 is connected to the raw material container 18 via a gas flow rate control device 19, and a supply pipe 22 is connected to the raw material container 18. The supply pipe 22 is provided with a needle valve 23 and a solution flow controller 24, and the supply pipe 22 is connected to a vaporizer 26. A carrier gas introducing pipe 29 is connected to the vaporizer 26 via a needle valve 31 and a gas flow rate adjusting device 28. The carburetor 26 is further provided with a pipe 2
It is connected to the film forming chamber 10 by 7. A gas drain 32 and a drain 33 are connected to the vaporizer 26, respectively. In this apparatus, a carrier gas composed of an inert gas such as N ₂ , He, Ar is introduced into the raw material container 18 from the carrier gas introduction pipe 21, and the solution raw material stored in the raw material container 18 is vaporized by the supply pipe 22. It is conveyed to the container 26. The copper complex vaporized in the vaporizer 26 to become vapor is further supplied into the film forming chamber 10 through the pipe 27 by the carrier gas introduced into the vaporizer 26 from the carrier gas introduction pipe 28. In the film forming chamber 10, the vapor of the copper complex is thermally decomposed, and the copper or copper alloy produced thereby is deposited on the heated substrate 13 to form a copper thin film.

The copper thin film produced by using the solution raw material of the present invention is characterized by being firmly adhered to the base film and having high purity. This copper thin film is, for example, SiO _{2 on the} surface of a silicon substrate.
The TiN film or the TaN film formed on the film by the sputtering method or the MOCVD method is formed by the MOCVD method. The type of the substrate of the present invention is not particularly limited.

[0035]

EXAMPLES Next, examples of the present invention will be described in detail together with comparative examples. Example 1 First, 150 g of copper (I) chloride was added to n-hexane 1
00cc was poured to make a suspension. 50 g of 2,6-dimethyl-3,5-heptanedione was slowly added dropwise to this suspension, and the mixture was stirred at room temperature for 30 minutes. Next, the reaction solution is heated to 70 ° C.
After heating to reflux with, the reaction solution was filtered. The solvent was distilled off by reducing the pressure of the obtained filtrate to 20 torr and holding it for 30 minutes. The residue remaining after the solvent was distilled off was recrystallized from 100 cc of n-hexane to obtain Cu (II) (DMHD).
Got ₂ Next, the obtained Cu (II) (DMHD) ₂ was dissolved in an organic solvent, n-methyl-2-pyrrolidone, to obtain MOCV.
A solution raw material for Method D was prepared.

Example 2 A MOCVD solution raw material was prepared in the same manner as in Example 1 except that the organic solvent was DMA. <Example 3> Example 1 except that DTBA was used as the organic solvent.
A solution raw material for MOCVD was prepared in the same manner as. <Example 4> Example 1 except that the organic solvent was DNBA.
A solution raw material for MOCVD was prepared in the same manner as.

<Example 5> A solution raw material for MOCVD was prepared in the same manner as in Example 1 except that TTBA was used as the organic solvent. <Example 6> Example 1 except that DIPA was used as the organic solvent.
A solution raw material for MOCVD was prepared in the same manner as. <Example 7> Example 1 except that TIPA was used as the organic solvent.
A solution raw material for MOCVD was prepared in the same manner as.

Example 8 First, 150 g of copper (I) chloride was added to n.
-Pour 100 cc of hexane into a suspension. 2-Methyl-heptanedione (50 g) was slowly added dropwise to this suspension, and the mixture was stirred at room temperature for 30 minutes. Next, the reaction solution is heated to 70 ° C.
After heating to reflux with, the reaction solution was filtered. The solvent was distilled off by reducing the pressure of the obtained filtrate to 20 torr and holding it for 30 minutes. The residue remaining after the solvent was distilled off was recrystallized from 100 cc of n-hexane to obtain Cu (II) (EP) ₂ . Next, the obtained Cu (II) (EP) ₂ was dissolved in n-methyl-2-pyrrolidone as an organic solvent to prepare a solution raw material for MOCVD method.

<Example 9> A solution raw material for MOCVD was prepared in the same manner as in Example 8 except that the organic solvent was DMA. <Example 10> A solution raw material for MOCVD was prepared in the same manner as in Example 8 except that DTBA was used as the organic solvent. <Example 11> A solution raw material for MOCVD was prepared in the same manner as in Example 8 except that DNBA was used as the organic solvent.

<Example 12> A solution raw material for MOCVD was prepared in the same manner as in Example 8 except that TTBA was used as the organic solvent. <Example 13> A solution raw material for MOCVD was prepared in the same manner as in Example 8 except that DIPA was used as the organic solvent. <Example 14> A solution raw material for MOCVD was prepared in the same manner as in Example 8 except that TIPA was used as the organic solvent.

Example 15 A copper complex was added to Cu (II) (OD) ₂
A solution raw material for MOCVD was prepared in the same manner as in Example 1 except that the above was used. <Example 16> Example 1 except that the organic solvent was DMA.
A solution raw material for MOCVD was prepared in the same manner as in 5. <Example 17> A solution raw material for MOCVD was prepared in the same manner as in Example 15 except that DTBA was used as the organic solvent. <Example 18> A solution raw material for MOCVD was prepared in the same manner as in Example 15 except that DNBA was used as the organic solvent.

<Example 19> A solution raw material for MOCVD was prepared in the same manner as in Example 15 except that TTBA was used as the organic solvent. <Example 20> A solution raw material for MOCVD was prepared in the same manner as in Example 15 except that DIPA was used as the organic solvent. <Example 21> A solution raw material for MOCVD was prepared in the same manner as in Example 15 except that TIPA was used as the organic solvent.

Example 22 First, 150 g of copper (I) chloride
N-hexane (100 cc) was poured to obtain a suspension. 25 g of 2,6-dimethyl-3,5-heptanedione was added to this suspension.
And 25 g of heptanedione were slowly added dropwise, and the mixture was stirred at room temperature for 30 minutes. Then, the reaction solution was heated to 70 ° C. under reflux, and then the reaction solution was filtered. The solvent was distilled off by reducing the pressure of the obtained filtrate to 20 torr and holding it for 30 minutes.
Cu (II) (EIP) ₂ was obtained by recrystallizing the residue remaining after distilling off the solvent with 100 cc of n-hexane. Next, the obtained Cu (II) (EIP) ₂ was dissolved in n-methyl-2-pyrrolidone which is an organic solvent to prepare a solution raw material for the MOCVD method.

<Example 23> A solution raw material for MOCVD was prepared in the same manner as in Example 22 except that DMA was used as the organic solvent. <Example 24> A solution raw material for MOCVD was prepared in the same manner as in Example 22 except that DTBA was used as the organic solvent. <Example 25> A solution raw material for MOCVD was prepared in the same manner as in Example 22 except that DNBA was used as the organic solvent.

<Example 26> A solution raw material for MOCVD was prepared in the same manner as in Example 22 except that TTBA was used as the organic solvent. <Example 27> A solution raw material for MOCVD was prepared in the same manner as in Example 22 except that DIPA was used as the organic solvent. <Example 28> A solution raw material for MOCVD was prepared in the same manner as in Example 23 except that TIPA was used as the organic solvent.

<Comparative Example 1> A copper complex was added to Cu (II) (hfac)
_A solution raw material for MOCVD was prepared in the same manner as in Example 1 except that ₂ was used and isopropyl alcohol was used as the organic solvent. <Comparative Example 2> A solution raw material for MOCVD was prepared in the same manner as in Comparative Example 1 except that ethanol was used as the organic solvent. <Comparative Example 3> A solution raw material for MOCVD was prepared in the same manner as in Comparative Example 1 except that butyl acetate was used as the organic solvent.

Comparative Example 4 A solution raw material for MOCVD was prepared in the same manner as in Comparative Example 1 except that ethyl acetate was used as the organic solvent. <Comparative Example 5> Cu (II) (DPM) ₂ was used as the copper complex, and this copper complex was directly used as a MOCVD solution raw material without using an organic solvent.

<Comparative Test> Examples 1 to 28 and Comparative Example 1
The concentration of the copper complex contained in each of the solution raw materials obtained in Examples 1 to 5 was adjusted to 0.1 molar, and 5 types were prepared. As a substrate, a SiO ₂ film (thickness 5000
Å) TiN film (thickness 30n
A silicon substrate having m) formed thereon was prepared. The prepared substrate was placed in the film forming chamber of the MOCVD apparatus shown in FIG. 1 and the substrate temperature was set to 180 ° C. Vaporization temperature 70 ℃, pressure 5to
rr, that is, about 665 Pa, respectively. Ar gas was used as a carrier gas and the flow rate was 100 ccm. Supply the solution raw material at a rate of 0.5 cc / min, and
At 5, 10, 20 and 30 minutes, each type was taken out from the film forming chamber and the copper thin film formed on the substrate was subjected to the following test.

Film Thickness Measurement The film thickness of the copper thin film on the substrate after film formation was measured from a cross-sectional SEM (scanning electron microscope) image. Peeling Test A peeling test (JIS K5600-5-6) was performed on the substrate on which the copper thin film was formed and taken out at each film forming time. Specifically, first, a lattice pattern was formed on the substrate by making 6 incisions in the copper thin film on the substrate so as to penetrate the film at equal intervals in the vertical and horizontal directions. Then brushed back and forth with a soft brush along both diagonals of the formed grid pattern.

Thermal Stability Evaluation Test The following test was conducted using the test apparatus shown in FIG. The apparatus shown in FIG. 2 has a structure in which the film forming chamber of the MOCVD apparatus shown in FIG. 1 is removed. First, the solution raw material is conveyed to the vaporizer 26 heated to 70 ° C. at room temperature, heated to 70 ° C. under a reduced pressure of 5 Torr to vaporize the solution raw material, and then the cold side provided on the pump side of the lower stage of the vaporizer 26. The compound after vaporization was captured by the trap 15. The trap recovery rate was calculated from the trapped amount of the raw material charged into the apparatus.
Further, the pressure sensor measured the pressure rise inside the vaporizer. For example, if the value in the table is 60% occlusion,
This means that a pressure of 1.60 times 5 Torr is generated in the vaporizer.

Examples 1 to 8 are shown in Table 1, Examples 9 to 16 are shown in Table 2, Examples 17 to 24 are shown in Table 3, and Examples 25 to 28 are shown.
Table 4 shows Comparative Examples 1 to 4 and Table 5 shows Comparative Example 5, respectively.

[0052]

[Table 1]

[0053]

[Table 2]

[0054]

[Table 3]

[0055]

[Table 4]

[0056]

[Table 5]

As is clear from Tables 1 to 5, Comparative Example 1
It can be seen that the copper thin films formed by using the solution raw materials Nos. 5 to 5 have variations in film thickness per film forming time, and the film forming reproducibility is poor. In addition, the film formation rate is also very slow. Moreover, in the adhesion evaluation test, the copper thin film was peeled from the substrate surface in most of the samples. In the thermal stability evaluation test, the trap recovery rate is low, and it is considered that most of the trap adhered to the inside of the device. Further, the pressure rise value inside the vaporizer also rises as the film forming time becomes longer, and it is considered that the decomposition product adhered to the inside of the vaporizer and the inside of the pipe to raise the pressure. On the other hand, the copper thin films produced using the solution raw materials of Examples 1 to 28 have a larger film thickness as the film forming time progresses, and it can be seen that the film forming stability is high. In the adhesion evaluation test, 95 to 99 times out of 100 times, most of the copper thin films did not peel off in any of the examples, and it was found that the adhesion was very high. In the thermal stability evaluation test, it showed a high trap recovery rate within the range of 58 to 68%, and the pressure rise value inside the vaporizer was also 1%.
There is almost no risk of blockage.

[0058]

As described above, the MOCV of the present invention in which the β-diketonate complex of copper (II) is dissolved in an amine solvent.
The solution raw material for D can be stably supplied during film formation, and when a copper thin film is prepared using this solution raw material, a high purity copper thin film can be obtained due to the high reducing property of the amine solvent.
It also has excellent thermal stability and is resistant to decomposition during storage and has a long life. Further, the ligand of the copper complex is composed of C, H and O, and hf
Since it does not contain F (fluorine) like ac, MOCVD
The equipment is not easily corroded, and the exhaust gas treatment in the MOCVD process is not complicated. MOCVD using the solution raw material of the present invention
The copper thin film produced by the method becomes a high-purity film that firmly adheres to the base film.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a MOCVD apparatus.

FIG. 2 is a schematic diagram showing an apparatus used in an embodiment of the present invention.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Katsumi Ogi             1002 Mukayama, Naka-machi, Naka-machi, Naka-gun, Ibaraki Prefecture 14 Mitsubishi             Materials Research Laboratories Naka Research Center             In the center F-term (reference) 4H006 AA03 AB78 AB80 AB91                 4H048 AA03 AB78 AB91 VA22 VA56                       VB10                 4K030 AA11 BA01 FA10                 4M104 BB04 DD45

Claims (8)

[Claims] 1. A solution raw material for a metal organic chemical vapor deposition method in which a β-diketonate complex of copper (II) is dissolved in an organic solvent, wherein the organic solvent is an amine solvent. Solution raw material. 2. The amine solvent is n-methyl-2-pyrrolidone, dimethylaniline, di-t-butylaniline, di-n-.
The compound is one or more compounds selected from the group consisting of butylaniline, diisopropylaniline, tri-t-butylaniline and triisopropylaniline.
The solution raw material described. 3. The solution raw material according to claim 1, wherein the β-diketonate complex of copper (II) is represented by the following formula (1). [Chemical 1] However, R is an isopropyl group. 4. The solution raw material according to claim 1, wherein the β-diketonate complex of copper (II) is represented by the following formula (2). [Chemical 2] Provided that R ₁ and R ′ ₁ are each an ethyl group, R ₂ and R ′ ₂ are each an isopropyl group, or R ′ ₁ and R ₂ are an isopropyl group, and R ₁ and R ′ ₂ Are each an ethyl group, or R ₁ and R ′ ₁ are each a methyl group, R ₂ and R ′ ₂ are each an n-butyl group, or R ′ ₁ and R ₂ are each an n- It is a butyl group, and R ₁ and R ′ ₂ are each a methyl group. 5. The solution raw material according to claim 4, wherein the β-diketonate complex of copper (II) is a mixture of a compound represented by the following formula (3) and a compound represented by the following formula (4). [Chemical 3] However, R ₃ and R ′ ₃ are each an ethyl group, and R ₄ and R ′ ₄ are each an isopropyl group. [Chemical 4] However, R ′ ₅ and R ₆ are isopropyl groups, and R ₅ and R ′ ₆ are ethyl groups, respectively. 6. The solution raw material according to claim 4, wherein the β-diketonate complex of copper (II) is a mixture of a compound represented by the following formula (5) and a compound represented by the following formula (6). [Chemical 5] However, R ₇ and R ′ ₇ are each a methyl group, and R ₈ and R ′ ₈ are each an n-butyl group. [Chemical 6] Provided that R ′ ₉ and R ₁₀ are each an n-butyl group,
₉ and R _'10 are each a methyl group. 7. The solution raw material according to claim 1, wherein the β-diketonate complex of copper (II) is represented by the following formula (7). [Chemical 7] However, R ₁ is an isopropyl group and R ₂ is an ethyl group. 8. A copper thin film produced by a metal organic chemical vapor deposition method using the solution raw material according to claim 1.