METHOD FOR FORMING COPPER-BASED FILM AND MATERIAL FOR FORMING COPPER-BASED FILM

- GAS-PHASE GROWTH LTD.

The present invention is directed to a method for forming a copper-based film on a substrate in supercritical fluid, wherein (N,N′-Diisopropylpropion amidinate) copper dimer is dissolved in supercritical fluid and copper is deposited on the substrate to form the copper-based film thereon.

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Description
TECHNICAL FIELD

The present invention relates to a technology for forming a copper-based film.

BACKGROUND ART

Films made of, for example, copper or copper alloy (hereinafter collectively referred to as copper) are employed in various kinds of fields. For example, the films are employed in a field of ULSI for the purpose of providing wiring films. An electrolytic plating method, a sputtering method, a CVD method, an ALD method, or a SCFD (Supercritical Fluid Deposition) method is proposed for producing copper wirings. The electrolytic plating method and the sputtering method are in practical use. However, it is said that it is hard to produce wiring films having a wiring width of a nano-scale by the electrolytic plating method and the sputtering method. The CVD method, the ALD method, and the SCFD method are expected for the formation of a film onto a deep groove (or hole) with an opening having a nano-scale width. In the CVD method and the ALD method, vaporization (gasification) of a starting material is essential. To the contrary, in the SCFD method, gasification is not required but only dissolving of the starting material in supercritical fluid is required. In this point, there is a difference in condition between the starting material to be used in the CVD method and the ALD method and the starting material to be used in the SCFD method.

The following Non-patent Literatures are known as the technology for forming the copper film by the SCFD method.

CITATION LIST Non-Patent Literature [NON-PATENT LITERATURE 1]

Journal of Jpn. J. Appl. Phys. 2005, 44, L1199-L1202. Takeshi Momose, Masakazu Sugiyama and Yukihiro Shimogaki “Precursor Evaluation for Cu-Supercritical Fluid Deposition Based on Adhesion Properties and Surface Morphology”

[NON-PATENT LITERATURE 2]

Journal of Electrochemical Society, 2009, 156, 6, H44341447. Masahiro Matsubaraa, Michiru Hirosea, Kakeru Tamaia, Yukihiro Shimogaki and Eiichi Kondoha“Kinetics of Deposition of Cu Thin Films in Supercritical Carbon Dioxide Solutions from a F-Free Copper(II)-Diketone Complex”

Patent Literature [PATENT LITERATURE] US7241912B2 SUMMARRY OF INVENTION Technical Problem

In the above Non-patent Literatures, β-diketone copper complexes such as a complex of (hexafluoroacetylacetonato)copper [Cu(hfac)2] and a complex of (diisobutylmethanato) copper [Cu(dibm)2] were used to perform deposition of copper (formation of a copper film) in supercritical fluid of CO2. As a result thereof, a copper film was formed by the SCFD method.

However, thus obtained copper film contained a large amount of impurities.

A cause thereof was searched.

As a result of the search, the inventors came to know that chemical compounds such as Cu(hfac)2 and Cu(dibm)2 require high temperature in order to be decomposed in the supercritical fluid. The inventors presumed that β-diketone of a ligand was decomposed therein and, therefore, C and O were contaminated in the copper film.

Further, in a case where the Cu(hfac)2 was used, F was detected in the copper film. Contamination of F in the copper film induced deterioration of adhesion between a base film and the copper film.

Accordingly, the inventors came to know that solution of starting material in the supercritical fluid is not the only requirement in the SCFD method.

However, it is still essential to dissolve the starting material in the supercritical fluid.

Under the circumstances, the present invention is made to solve the above problems. Specifically, the present invention is made to provide a technology for forming a high quality copper film with ease. With the technology, decomposition temperature in the supercritical fluid is low and degradation of quality of the copper film due to contamination of C and/or O can be improved.

Solution to Problem

The inventors have conducted intensive studies in order to solve the above problems.

As a result thereof, the inventors came to know that, in a case where a chemical compound (copper amidinate complex), being dissolved in the supercritical fluid, represented by the following General Formula [I] is used to perform a deposition reaction, the amount of contamination of the impurities (C, O) in the deposition film is small and, therefore, a high quality Cu-based film is stably formed in the groove (or the hole) of a nano-scale.

The above listed Patent Literature discloses a chemical compound (metal amidinate complex) represented by the following General Formula [I].

However, the above listed Patent Literature is silent on a technology of dissolving the chemical compound represented by the following General Formula [I] in the supercritical fluid and depositing copper on a substrate.

In addition to the above, the inventors of the present invention believe that a scientist (technical expert) having ordinary knowledge in this field had no idea to dissolve a Cu amidinate complex in the supercritical fluid (e.g., CO2) and deposit copper on the substrate.

The metal amidinate complex is known by its property of being decomposed immediately in the air. For example, a Li amidinate complex, an Na amidinate complex, a K amidinate complex, a Mg amidinate complex, a Ca amidinate complex, a Sr amidinate complex, a Ba amidinate complex, a Ti amidinate complex, a V amidinate complex, a Cr amidinate complex, a Mn amidinate complex, a Fe amidinate complex, a Co amidinate complex, an Ni amidinate complex, a Zn amidinate complex, a Cd amidinate complex, and a Sn amidinate complex are known as having the property of being immediately decomposed in the air. Further, the metal amidinate complex is known by a property of reacting with ketone (e.g., acetone and methyl isobutyl ketone) and CO2.

In view of the above, the inventors of the present invention believe that a scientist (technical expert) having ordinary knowledge in this field had no idea to dissolve a Cu amidinate complex in the supercritical fluid (e.g., CO2) and deposit copper on the substrate.

However, the inventors of the present invention found that the Cu amidinate complex represented by the following General Formula [I] dissolves in ketone and CO2 as well as that no reaction is produced therebetween.

The present invention was made based on the above knowledge.

The present invention proposes a material for forming a copper-based film on a substrate by decomposing a chemical compound dissolved in supercritical fluid, wherein the chemical compound is a chemical compound represented by the following General Formula [I].

The present invention proposes a method for forming a copper-based film on a substrate in supercritical fluid, wherein a chemical compound represented by the following General Formula [I] is dissolved in supercritical fluid and copper is deposited on the substrate to form a copper-based film thereon.

[Each of R1, R2, R3, R4, R5, and R6 is a hydrocarbon group having a carbon number of 1 to 10. The R1, R2, R3, R4, R5, and R6 maybe the same or may be different from one another.]

Advantageous Effect of Invention

According to the present invention, it is possible to stably form a high quality Cu-based film (e.g., a film containing little impurities such as C and O) in a groove (or a hole) of a nano-scale.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic drawing of a SCFD system.

FIG. 2 is an electron micrography.

FIG. 3 is another electron micrography.

 DESCRIPTION OF EMBODIMENTS

A first invention is directed to a method for forming a copper-based film. The method is a method in which a chemical compound represented by the following General Formula [I] is dissolved in supercritical fluid and copper is deposited on a substrate to form a copper-based film thereon.

A second invention is directed to a material for forming a copper-based film. The material is a material for forming a copper-based film on a substrate by decomposing a chemical compound dissolved in supercritical fluid. The chemical compound is a chemical compound represented by the following General Formula [I].

[Each of R1, R2, R3, R4, R5, and R6 is a hydrocarbon group having a carbon number of 1 to 10. The hydrocarbon group may be an aliphatic hydrocarbon group or may be an aromatic hydrocarbon group. The hydrocarbon group may have a substituent or may not have a substituent. The substituent may be a functional group having Si. The R1, R2, R3, R4, R5, and R6 may be the same or may be different from one another. Preferably, R1, R2, R4, and R5 differ from R3 and R6.

The chemical compound represented by the General Formula [I] is a solid in many cases. In a case where the chemical compound is a solid, it is more preferred to supply the chemical compound to the supercritical fluid, with the chemical compound being dissolved in a solvent (in a solution form), than to supply the chemical compound as it is to the supercritical fluid in order to well dissolve the chemical compound in the supercritical fluid. The solvent may be any solvent in so far as the solvent does not adversely effects on the chemical compound and the supercritical fluid. Preferable solvent is one or more selected from ketone (e.g., acetone, methylethyl ketone, methylpropyl ketone, methyl isobutyl ketone, methyl amyl ketone, diethyl ketone, and cyclohexanone), ether (e.g., diethyl ether, tetrahydrofuran, and dioxane), and hydrocarbon (e.g., pentane, hexane, heptanes, octane, nonane, and decane). The hydrocarbon may be any one of straightly chained aliphatic hydrocarbon, aliphatic hydrocarbon having branched chain, or cyclic hydrocarbon.

The most preferable chemical compound as the chemical compound that is represented by the General Formula [I] has such a structure that each of R1, R2, R4, and R5 is an iso-propyl group, and each of R3 and R6 is an ethyl group (i.e., (N,N′-Diisopropylpropionamidinate) copper dimer).

A preferable chemical compound as the chemical compound that is represented by the General Formula [I] has such a structure that each of R1, R2, R4, and R5 is an iso-propyl group, and each of R3 and R6 is a methyl group (i.e., (N,N′-Diisopropylacetoamidinate) copper dimer).

A preferable chemical compound as the chemical compound that is represented by the General Formula [I] has such a structure that each of R1, R2, R4, and R5 is an iso-propyl group, and each of R3 and R6 is an n-butyl group (i.e., amidinate copper).

A preferable chemical compound as the chemical compound that is represented by the General Formula [I] has such a structure that each of R1, R2, R4, and R5 is an n-propyl group, and each of R3 and R6 is a methyl group (i.e., amidinate copper).

A preferable chemical compound as the chemical compound that is represented by the General Formula [I] has such a structure that each of R1, R2, R4, and R5 is an n-propyl group, and each of R3 and R6 is an ethyl group (i.e., amidinate copper).

A preferable chemical compound as the chemical compound that is represented by the General Formula [I] has such a structure that each of R1, R2, R4, and R5 is an n-propyl group, and each of R3 and R6 is an n-butyl group (i.e., amidinate copper).

A preferable chemical compound as the chemical compound that is represented by the General Formula [I] has such a structure that each of R1, R2, R4, and R5 is an n-butyl group, and each of R3 and R6 is a methyl group (i.e., amidinate copper).

A preferable chemical compound as the chemical compound that is represented by the General Formula [I] has such a structure that each of R1, R2, R4, and R5 is an n-butyl group, and each of R3 and R6 is an ethyl group (i.e., amidinate copper).

A preferable chemical compound as the chemical compound that is represented by the General Formula [I] has such a structure that each of R1, R2, R4, and R5 is an iso-butyl group, and each of R3 and R6 is a methyl group (i.e., amidinate copper).

A preferable chemical compound as the chemical compound that is represented by the General Formula [I] has such a structure that each of R1, R2, R4, and R5 is an iso-butyl group, and each of R3 and R6 is an ethyl group (i.e., amidinate copper).

A preferable chemical compound as the chemical compound that is represented by the General Formula [I] has such a structure that each of R1, R2, R4, and R5 is an iso-butyl group, and each of R3 and R6 is an n-butyl group (i.e., amidinate copper).

A preferable chemical compound as the chemical compound that is represented by the General Formula [I] has such a structure that each of R1, R2, R4, and R5 is a sec-butyl group, and each of R3 and R6 is a methyl group (i.e., amidinate copper).

A preferable chemical compound as the chemical compound that is represented by the General Formula [I] has such a structure that each of R1, R2, R4, and R5 is a sec-butyl group, and each of R3 and R6 is an ethyl group (i.e., amidinate copper).

A preferable chemical compound as the chemical compound that is represented by the General Formula [I] has such a structure that each of R1, R2, R4, and R5 is a sec-butyl group, and each of R3 and R6 is an n-butyl group (i.e., amidinate copper).

A preferable chemical compound as the chemical compound that is represented by the General Formula [I] has such a structure that each of R1, R2, R4, and R5 is a phenyl group, and each of R3 and R6 is a methyl group (i.e., amidinate copper).

A preferable chemical compound as the chemical compound that is represented by the General Formula [I] has such a structure that each of R1, R2, R4, and R5 is a phenyl group, and each of R3 and R6 is an ethyl group (i.e., amidinate copper).

When a certain substance is placed under the temperature more than a critical point and the pressure more than a critical point, the phenomenon of supercritical fluid will appear. Supercritical fluid is fluid in a state where discrimination is not made between gas and a fluid. Supercritical fluid has both of the diffusibility of gas and the solubility of a fluid. CO2 becomes supercritical fluid under the conditions of a temperature of 304.1K or more and a pressure of 7.38 MPa or more. H2O becomes supercritical fluid under the conditions of a temperature of 647.3K or more and a pressure of 22.12 MPa or more. CH1 becomes supercritical fluid under the conditions of a temperature of 190.4K or more and a pressure of 4.60 MPa or more. C2H6 becomes supercritical fluid under the conditions of a temperature of 305.3K or more and a pressure of 4.87 MPa or more. C2H4 becomes supercritical fluid under the conditions of a temperature of 282.4K or more and a pressure of 5.04 MPa or more. CH3CH2OH becomes supercritical fluid under the conditions of a temperature of 513.9K or more and a pressure of 6.14 MPa or more. CH3COCH3 becomes supercritical fluid under the conditions of a temperature of 508.1K or more and a pressure of 4.70 MPa or more. In the present invention, any one of the above described supercritical fluids may be used. Here, preferable supercritical fluid contains CO2. More preferable supercritical fluid is a mixture of CO2 and H2.

Hereinafter, more specific examples will be described. However, the present invention will not be limited to the examples described below. All modifications and applications which do not depart from the spirit and scope of the present invention are deemed to be covered by the invention.

Example 1 Deposition of Copper in Supercritical Fluid of CO2 Using a (N,N′-Diisopropylpropion Amidinate) Copper Complex

FIG. 1 is a schematic drawing of a SCFD apparatus which performs a copper-based film forming method according to the present invention.

In FIG. 1, 1 denotes a CO2 high pressure cylinder, 2 denotes a H2 high pressure cylinder, 3 denotes a cooling device, 4 denotes pressure pumps (10 MPa), 5 denotes a mixer, 6 denotes a container, 7 denotes heaters, 8 denotes a preheating chamber, 9 denotes a reaction chamber, 10 denotes a substrate (a silicon substrate provided with a ruthenium thin film), and 11 denotes a back pressure governor.

An acetone solution (concentration of 3.34×10−5 mol) of the (N,N′-Diisopropylpropion amidinate) copper dimer (In the General Formula [I], R1═R2═R4=R5═—CH(CH3)2, R3═R6═—CH2CH3) is placed in the container 6.

The reaction chamber 9 is kept at a temperature of 140° C. by the heaters 7. The reaction chamber 9 is kept at 13 MPa by supercritical fluid (CO2+H2). A partial pressure of CO2 was 12 MPa, and a partial pressure of H2 was 1 MPa.

The acetone solution of the (N,N′-Diisopropylpropion amidinate) copper dimer was supplied to the reaction chamber 9 using the pumps 4. In other words, the (N,N′-Diisopropylpropion amidinate) copper dimer was supplied to the supercritical fluid. The supercritical fluid containing the chemical compound represented by the General Formula [I] was supplied to a surface of the substrate 10. The chemical compound of the General Formula [I] was decomposed. This achieved deposition of copper film on the surface. The substrate 10 was taken out after 15 minutes from the start of supply of the starting material. A film of a copper color was formed on the taken out substrate 10.

The substrate 10 was subjected to an EDS analysis (Energy dispersive X-ray spectrometry). As a result of the analysis, no C or O was observed in the film formed on a surface of the substrate 10. By an X-ray diffraction, it was found that the film was a copper thin film in which the copper is mainly oriented to (111). With the use of the electron microscope, it was found that an inside of the groove (having a width of 140 nm and a depth of 1.6 μm) formed in the substrate 10 was completely filled with copper (see, FIG. 2).

Example 2

A copper-based film forming method was carried out in a manner identical to that performed in Example 1 except that the heating temperature by the heaters 7 was changed from 140° C. to 160° C. A result similar to that of Example 1 was obtained (see, FIG. 3). Generally, as the temperature becomes higher, the embeddability becomes poorer. However, as the temperature becomes higher, the throughput becomes better. The present example shows that good embeddability was achieved even at a temperature of 160° C.

Example 3

The copper-based film forming method was carried out in a manner identical to that performed in Example 1 except that n-pentane was employed instead of acetone. A result similar to that of Example 1 was obtained. However, the (N,N′-Diisopropylpropion amidinate) copper dimer indicated solubility poorer than the case of Example 1. In other words, in the present example, a concentration of the chemical compound (General Formula [I]) in the solution was low. Therefore, it took about 20% longer time for the deposition of a copper film than the case of Example 1.

Example 4

The copper-based film forming method was carried out in a manner identical to that performed in Example 1 except that cyclohexane was employed instead of acetone. A result similar to that of Example 1 was obtained. However, the (N,N′-Diisopropylpropion amidinate) copper dimer indicated solubility poorer than the case of Example 1. In other words, in the present example, a concentration of the chemical compound (General Formula [I]) in the solution was low. Therefore, it took about 20% longer time for the deposition of a copper film than the case of Example 1.

Example 5

The copper-based film forming method was carried out in a manner identical to that performed in Example 1 except that n-heptane was employed instead of acetone. A result similar to that of Example 1 was obtained. However, the (N,N′-Diisopropylpropion amidinate) copper dimer indicated solubility poorer than the case of Example 1. In other words, in the present example, a concentration of the chemical compound (General Formula [I]) in the solution was low. Therefore, it took about 20% longer time for the deposition of a copper film than the case of Example 1.

Example 6

The copper-based film forming method was carried out in a manner identical to that performed in Example 1 except that n-octane was employed instead of acetone. A result similar to that of Example 1 was obtained. However, the (N,N′-Diisopropylpropion amidinate) copper dimer indicated solubility poorer than the case of Example 1. In other words, in the present example, a concentration of the chemical compound (General Formula [I]) in the solution was low. Therefore, it took about 20% longer time for the deposition of a copper film than the case of Example 1.

Example 7

The copper-based film forming method was carried out in a manner identical to that performed in Example 1 except that n-nonane was employed instead of acetone. A result similar to that of Example 1 was obtained. However, the (N,N′-Diisopropylpropion amidinate) copper dimer indicated solubility poorer than the case of Example 1. In other words, in the present example, a concentration of the chemical compound (General Formula [I]) in the solution was low. Therefore, it took about 20% longer time for the deposition of a copper film than the case of Example 1.

Example 8

The copper-based film forming method was carried out in a manner identical to that performed in Example 1 except that n-decane was employed instead of acetone. A result similar to that of Example 1 was obtained. However, the (N,N′-Diisopropylpropion amidinate) copper dimer indicated solubility poorer than the case of Example 1. In other words, in the present example, a concentration of the chemical compound (General Formula [I]) in the solution was low. Therefore, it took about 20% longer time for the deposition of a copper film than the case of Example 1.

Example 9

The copper-based film forming method was carried out in a manner identical to that performed in Example 1 except that methyl isobutyl ketone was employed instead of acetone. A result similar to that of Example 1 was obtained.

Example 10

The copper-based film forming method was carried out in a manner identical to that performed in Example 1 except that diethyl ether was employed instead of acetone. A result similar to that of Example 1 was obtained. However, 0 was slightly observed in a Cu-based film in the EDS analysis.

Example 11

The copper-based film forming method was carried out in a manner identical to that performed in Example 1 except that tetrahydrofuran was employed instead of acetone. A result similar to that of Example 1 was obtained. However, 0 was slightly observed in a Cu-based film in the EDS analysis.

Example 12

The copper-based film forming method was carried out in a manner identical to that performed in Example 1 except that dioxane was employed instead of acetone. A result similar to that of Example 1 was obtained. However, 0 was slightly observed in a Cu-based film in the EDS analysis.

Example 13

The copper-based film forming method was carried out in a manner identical to that performed in Example 1 except that (N,N′-Diisopropylaceto amidinate) copper dimer was employed instead of (N,N′-Diisopropylpropion amidinate) copper dimer. Thus obtained film was almost identical to that of Example 1. However, it took about 20% longer time in order to obtain the film thickness identical to that of Example 1.

Example 14

The copper-based film forming method was carried out in a manner identical to that performed in Example 1 using the chemical compound of the General Formula [I] (each of R1, R2, R4, and R5 was an iso-propyl group, and each of R3 and R6 was an n-butyl group). Thus obtained film was almost identical to that of Example 1. However, it took about 20% longer time in order to obtain the film thickness identical to that of Example 1.

Example 15

The copper-based film forming method was carried out in a manner identical to that performed in Example 1 using the chemical compound of the General Formula [I] (each of R1, R2, R4, and R5 was an n-propyl group, and each of R3 and R6 was a methyl group). Thus obtained film was almost identical to that of Example 1. However, it took about 20% longer time in order to obtain the film thickness identical to that of Example 1.

Example 16

The copper-based film forming method was carried out in a manner identical to that performed in Example 1 using the chemical compound of the General Formula [I] (each of R1, R2, R4, and R5 was an n-propyl group, and each of R3 and R6 was an ethyl group). Thus obtained film was almost identical to that of Example 1. However, it took about 20% longer time in order to obtain the film thickness identical to that of Example 1.

Example 17

The copper-based film forming method was carried out in a manner identical to that performed in Example 1 using the chemical compound of the General Formula [I] (each of R1, R2, R4, and R5 was an n-propyl group, and each of R3 and R6 was an n-butyl group). Thus obtained film was almost identical to that of Example 1. However, it took about 20% longer time in order to obtain the film thickness identical to that of Example 1.

Example 18

The copper-based film forming method was carried out in a manner identical to that performed in Example 1 using the chemical compound of the General Formula [I] (each of R1, R2, R4, and R5 was an n-butyl group, and each of R3 and R6 was a methyl group). Thus obtained film was almost identical to that of Example 1. However, it took about 20% longer time in order to obtain the film thickness identical to that of Example 1.

Example 19

The copper-based film forming method was carried out in a manner identical to that performed in Example 1 using the chemical compound of the General Formula [I] (each of R1, R2, R4, and R5 was an n-butyl group, and each of R3 and R6 was an ethyl group). Thus obtained film was almost identical to that of Example 1. However, it took about 20% longer time in order to obtain the film thickness identical to that of Example 1.

Example 20

The copper-based film forming method was carried out in a manner identical to that performed in Example 1 using the chemical compound of the General Formula [I] (each of R1, R2, R4, and R5 was an iso-butyl group, and each of R3 and R6 was a methyl group). Thus obtained film was almost identical to that of Example 1. However, it took about 20% longer time in order to obtain the film thickness identical to that of Example 1.

Example 21

The copper-based film forming method was carried out in a manner identical to that performed in Example 1 using the chemical compound of the General Formula [I] (each of R1, R2, R4, and R5 was an iso-butyl group, and each of R3 and R6 was an ethyl group). Thus obtained film was almost identical to that of Example 1. However, it took about 20% longer time in order to obtain the film thickness identical to that of Example 1.

Example 22

The copper-based film forming method was carried out in a manner identical to that performed in Example 1 using the chemical compound of the General Formula [I] (each of R1, R2, R4, and R5 was an iso-butyl group, and each of R3 and R6 was an n-butyl group). Thus obtained film was almost identical to that of Example 1. However, it took about 20% longer time in order to obtain the film thickness identical to that of Example 1.

Example 23

The copper-based film forming method was carried out in a manner identical to that performed in Example 1 using the chemical compound of the General Formula [I] (each of R1, R2, R4, and R5 was an sec-butyl group, and each of R3 and R6 was a methyl group). Thus obtained film was almost identical to that of Example 1. However, it took about 20% longer time in order to obtain the film thickness identical to that of Example 1.

Example 24

The copper-based film forming method was carried out in a manner identical to that performed in Example 1 using the chemical compound of the General Formula [I] (each of R1, R2, R4, and R5 was an sec-butyl group, and each of R3 and R6 was an ethyl group). Thus obtained film was almost identical to that of Example 1. However, it took about 20% longer time in order to obtain the film thickness identical to that of Example 1.

Example 25

The copper-based film forming method was carried out in a manner identical to that performed in Example 1 using the chemical compound of the General Formula [I] (each of R1, R2, R4, and R5 was an sec-butyl group, and each of R3 and R6 was an n-butyl group). Thus obtained film was almost identical to that of Example 1. However, it took about 20% longer time in order to obtain the film thickness identical to that of Example 1.

Example 26

The copper-based film forming method was carried out in a manner identical to that performed in Example 1 using the chemical compound of the General Formula [I] (each of R1, R2, R4, and R5 was a phenyl group, and each of R3 and R6 was a methyl group). Thus obtained film was almost identical to that of Example 1. However, it took about 30% longer time in order to obtain the film thickness identical to that of Example 1.

Example 27

The copper-based film forming method was carried out in a manner identical to that performed in Example 1 using the chemical compound of the General Formula [I] (each of R1, R2, R4, and R5 was a phenyl group, and each of R3 and R6 was an ethyl group). Thus obtained film was almost identical to that of Example 1. However, it took about 25% longer time in order to obtain the film thickness identical to that of Example 1.

Comparison Example 1

The copper-based film forming method was carried out in a manner identical to that performed in Example 1 except that bis(diisobutylmethanato) copper [Cu(dibm)2] was employed instead of the chemical compound of the General Formula [I] of Example 1. However, a Cu film was not formed.

Comparison Example 2

The copper-based film forming method was carried out in a manner identical to that performed in Comparison Example 1 except that a heating temperature by the heaters 7 was changed from 140° C. to 240° C. In this Comparison Example, a Cu film was formed. However, impurities of C and O were observed in thus obtained Cu film.

Comparison Example 3

The copper-based film forming method was carried out in a manner identical to that performed in Example 1 except that bis(hexafluoroacetylacetonato) copper [Cu(hfac)2] was employed instead of the chemical compound of the General Formula [I] of Example 1. However, a Cu film was not formed.

Comparison Example 4

The copper-based film forming method was carried out in a manner identical to that performed in Comparison Example 3 except that the heating temperature by the heaters 7 was changed from 140° C. to 240° C. In this Comparison Example, a Cu film was formed. However, impurities of C, 0, and F were observed in thus obtained Cu film.

REFERENCE SIGNS LIST

  • 1 CO2 high pressure cylinder
  • 2 H2 high pressure cylinder
  • 3 cooling device
  • 4 pressure pump
  • 5 mixer
  • 6 material container
  • 7 heater
  • 8 preheating chamber
  • 9 reaction chamber
  • 10 substrate
  • 11 back pressure governor

Claims

1. A method for forming a copper-based film on a substrate in supercritical fluid, wherein a chemical compound represented by the following Formula [I] is dissolved in the supercritical fluid and copper is deposited on the substrate to form the copper-based film thereon.

wherein each of R1, R2, R3, R4, R5, and R6 is a hydrocarbon group having a carbon number of 1 to 10, and wherein R1, R2, R3, R4, R5, and R6 may be the same or may be different from one another.

2. The method for forming a copper-based film according to claim 1, wherein the chemical compound represented by the Formula [I] is dissolved in a solvent and then supplied to the supercritical fluid to be dissolved therein.

3. The method for forming a copper-based film according to claim 2, wherein the solvent is one or more selected from a ketone, an ether, and a hydrocarbon.

4. The method for forming a copper-based film according to claim 3, wherein the solvent is a ketone.

5. The method for forming a copper-based film according to claim 4, wherein the solvent is one or more selected from acetone, methylethyl ketone, methylpropyl ketone, methyl isobutyl ketone, methyl amyl ketone, diethyl ketone, and cyclohexanone.

6. The method for forming a copper-based film according to claim 1, wherein each of R1, R2, R4, and R5 is an iso-propyl group, and each of R3 and R6 is independently selected from a methyl group, an ethyl group, and an n-butyl group.

7. The method for forming a copper-based film according to claim 1, wherein each of R1, R2, R4, and a R5 is an iso-propyl group, and each of R3 and R6 is an ethyl group.

8. The method for forming a copper-based film according to claim 1, wherein each of R1, R2, R4, and R5 is an n-propyl group, and each of R3 and R6 is independently selected from a methyl group, an ethyl group, and an n-butyl group.

9. The method for forming a copper-based film according to claim 1, wherein each of R1, R2, R4, and R5 is an n-butyl group, and each of R3 and R6 is independently selected from a methyl group and an ethyl group.

10. The method for forming a copper-based film according to claim 1, wherein each of R1, R2, R4, and R5 is an iso-butyl group, and each of R3 and R6 is independently selected from a methyl group, an ethyl group, and an n-butyl group.

11. The method for forming a copper-based film according to claim 1, wherein each of R1, R2, R4, and R5 is a sec-butyl group, and each of R3 and R6 is independently selected from a methyl group, an ethyl group, and an n-butyl group.

12. The method for forming a copper-based film according to claim 1, wherein each of R1, R2, R4, and R5 is a phenyl group, and each of R3 and R6 is independently selected from a methyl group and an ethyl group.

13. The method for forming a copper-based film according to claim 1, wherein the supercritical fluid is a supercritical fluid comprising CO2.

14. The method for forming a copper-based film according to claim 1, wherein the supercritical fluid is a mixture of CO2 and H2.

15. (canceled)

Patent History
Publication number: 20150211100
Type: Application
Filed: Nov 12, 2014
Publication Date: Jul 30, 2015
Applicant: GAS-PHASE GROWTH LTD. (Koganei-shi, Tokyo)
Inventors: Hideaki Machida (Kunitachi-shi), Masato Ishikawa (Nakano-ku), Hiroshi Sudoh (Koganei-shi), Eiichi Kondoh (Kofu-shi)
Application Number: 14/428,541
Classifications
International Classification: C23C 2/04 (20060101);