Heterogeneous polynuclear complex for use in the chemical deposition of composite metal or metal compound thin films

Abstract

A heterogeneous polynuclear complex for use as a raw material in the chemical deposition of composite metal or composite metal thin films with the below formula. In the formula, M.sub.1 and M.sub.2 are mutually different transition metals, x is an integer of 0 or more and 2 or less, y is in integer of 1 or more and 2 or less, z is an integer of 1 or more and 10 or less, R.sub.1 to R.sub.4 are each one of a hydrogen atom and an alkyl group with a carbon number of 1 or more and 5 or less, and R.sub.5 is a hydrogen atom, a carbonyl, an alkyl group with a carbon number of 1 or more and 7 or less, an allyl group or an allyl derivative. The heterogeneous polynuclear complex allows a composite metal thin film or a composite metal compound thin film containing a plurality of metals to be formed from a single raw material. ##STR00001##

Claims

1. A chemical deposition raw material for producing a composite metal thin film or a composite metal compound thin film by a chemical deposition method, comprising a heterogeneous polynuclear complex in which as ligands, at least a diimine (L) and a carbonyl are coordinated to a first transition metal (M.sub.1 ) and a second transition metal (M.sub.2) as central metals, the heterogeneous polynuclear complex being represented by the following formula: ##STR00014## wherein M.sub.1 and M.sub.2 are different transition metals; x is an integer of 0 or more and 2 or less, y is an integer of 1 or more and 2 or less, and z is an integer of 1 or more and 10 or less; R.sub.1 to R.sub.4 are each one of a hydrogen atom and an alkyl group with a carbon number of 1 or more and 5 or less; and R.sub.5 is a hydrogen atom, a carbonyl, an alkyl group with a carbon number of 1 or more and 7 or less, an allyl group or an allyl derivative.

2. The chemical deposition raw material according to claim 1, wherein x is 1, y is 1 and z is n +2, where n is the number of carbonyl groups bound to second transition metal M.sub.2, the chemical deposition raw material comprising a heterogeneous polynuclear complex represented by the following formula: ##STR00015## wherein M.sub.1 and M.sub.2 are different transition metals; n is 3 or more and 6 or less; Each of R.sub.1 and R.sub.4 is an alkyl group with a carbon number of 1 or more and 4 or less, and each of R.sub.2 and R.sub.3 is a hydrogen atom, or an alkyl group with a carbon number of 1 or more and 3 or less; and R.sub.5 is a carbonyl, or an alkyl group with a carbon number of 1 or more and 4 or less.

3. The chemical deposition raw material according to claim 2, wherein each of R.sub.1 and R.sub.4 is one of an ethyl group, a propyl group and a butyl group.

4. The chemical deposition raw material according to claim 2, wherein each of R.sub.2 and R.sub.3 is one of a hydrogen atom, a methyl group and an ethyl group.

5. The chemical deposition raw material according to claim 2, wherein R.sub.5 is a carbonyl group, methyl group, ethyl group or propyl group.

6. A chemical deposition method of a composite metal thin film or a composite metal compound thin film, comprising preparing a raw material gas by vaporizing a raw material defined in claim 2 including a heterogeneous polynuclear complex, and heating the raw material gas while introducing the raw material gas to a substrate surface to deposit a composite metal thin film or a composite metal compound thin film.

7. The chemical deposition raw material according to claim 1, wherein the transition metal is one of Mn, Fe, Co, Ni, Cu, Nb, Mo, Ru, Rh, Ta, W, Ir and Pt.

8. The chemical deposition raw material according to claim 7, wherein each of R.sub.1 and R.sub.4 is one of an ethyl group, a propyl group and a butyl group.

9. The chemical deposition raw material according to claim 7, wherein each of R.sub.2 and R.sub.3 is one of a hydrogen atom, a methyl group and an ethyl group.

10. The chemical deposition raw material according to claim 7, wherein R.sub.5 is a carbonyl group, methyl group, ethyl group or propyl group.

11. A chemical deposition method of a composite metal thin film or a composite metal compound thin film, comprising preparing a raw material gas by vaporizing a raw material defined in claim 7 including a heterogeneous polynuclear complex, and heating the raw material gas while introducing the raw material gas to a substrate surface to deposit a composite metal thin film or a composite metal compound thin film.

12. The chemical deposition raw material according to claim 1, wherein M.sub.1 is one of Ru, Mn and Fe, M.sub.2 is one of Mn, Fe, Co and Ni, and M.sub.1 and M.sub.2 are different.

13. The chemical deposition raw material according to claim 12, wherein each of R.sub.1 and R.sub.4 is one of an ethyl group, a propyl group and a butyl group.

14. The chemical deposition raw material according to claim 12, wherein each of R.sub.2 and R.sub.3 is one of a hydrogen atom, a methyl group and an ethyl group.

15. A chemical deposition method of a composite metal thin film or a composite metal compound thin film, comprising preparing a raw material gas by vaporizing a raw material defined in claim 12 including a heterogeneous polynuclear complex, and heating the raw material gas while introducing the raw material gas to a substrate surface to deposit a composite metal thin film or a composite metal compound thin film.

16. The chemical deposition raw material according to claim 1, wherein each of R.sub.1 and R.sub.4 is one of an ethyl group, a propyl group and a butyl group.

17. The chemical deposition raw material according to claim 16, wherein each of R.sub.2 and R.sub.3 is one of a hydrogen atom, a methyl group and an ethyl group.

18. The chemical deposition raw material according to claim 1, wherein each of R.sub.2 and R.sub.3 is one of a hydrogen atom, a methyl group and an ethyl group.

19. The chemical deposition raw material according to claim 1, wherein R.sub.5 is a carbonyl group, methyl group, ethyl group or propyl group.

20. A chemical deposition method of a composite metal thin film or a composite metal compound thin film, comprising preparing a raw material gas by vaporizing a raw material defined in claim 1 including a heterogeneous polynuclear complex, and heating the raw material gas while introducing the raw material gas to a substrate surface to deposit a composite metal thin film or a composite metal compound thin film.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 illustrates a TG curve of a metal complex produced in an embodiment.

(2) FIG. 2 shows a photograph of a cross-section of a metal thin film formed in an embodiment.

(3) FIG. 3 illustrates a Ru/Mn ratio in a metal thin film formed in an embodiment.

DESCRIPTION OF EMBODIMENT

(4) Hereinafter, the best embodiments in the present invention will be described.

(5) In the embodiments, the following four kinds of complexes were synthesized. Synthesized complexes were each evaluated for physical properties, and subjected to a film formation test as a chemical deposition raw material.

(6) ##STR00009##

EXAMPLE 1

(7) A heterogeneous polynuclear complex (pentacarbonyl[dicarbonyl(N,N-diisopropyl-1,4-diazabutadiene)methylruthenium]manganese (MnRu)) having ruthenium as a first transition metal and manganese as a second transition metal was produced. The synthesis reaction formula is as described below. Hereinafter, the production process will be described in detail.

(8) ##STR00010##

(9) 1.95 g (5 mmol) of decacarbonyldimanganese and 0.23 g (10 mmol) of metal sodium were added in a flask containing 250 ml of tetrahydrofuran. The solution was stirred at room temperature for 24 hours, a solution obtained by dissolving 4.39 g (10 mmol) of dicarbonyliodo(N,N-diisopropyl-1,4-diazabutadiene)methylruthenium in 250 ml of tetrahydrofuran was then added, and the mixture was stirred at room temperature for 4 hours. After completion of the reaction, the reaction product was concentrated to obtain a muddy reaction mixture. The reaction mixture was extracted with hexane, and purified by column chromatography with alumina as a carrier and hexane as an eluent. Sublimation purification was performed to obtain 3.30 g (6.5 mmol) of pentacarbonyl[dicarbonyl(N,N-diisopropyl-1,4-diazabutadiene)methylruthenium]manganese (MnRu) as a specified substance (yield: 65%).

EXAMPLE 2

(10) A heterogeneous polynuclear complex (tricarbonyl(N,N-diisopropyl-1,4-diazabutadiene)(tetracarbonylcobalt)manganes e (CoMn)) having manganese as a first transition metal and cobalt as a second transition metal was produced. The synthesis reaction formula is as described below. Hereinafter, the production process will be described in detail.

(11) ##STR00011##

(12) 1.71 g (5 mmol) of octacarbonyldicobalt and 0.23 g (10 mmol) of metal sodium were added in a flask containing 250 ml of tetrahydrofuran. The solution was stirred at room temperature for 24 hours, a solution obtained by dissolving 3.60 g (10 mmol) of bromotricarbonyl(N,N-diisopropyl-1,4-diazabutadiene)manganese in 250 ml of tetrahydrofuran was then added, and the mixture was stirred at room temperature for 4 hours. After completion of the reaction, the reaction product was concentrated, and then extracted with hexane. After recrystallization from hexane at 30 C., sublimation purification was performed to obtain 1.13 g (5.0 mmol) of tricarbonyl(N,N-diisopropyl-1,4-diazabutadiene)(tetracarbonylcobalt)manganes e (CoMn) as a specified substance (yield: 50%).

EXAMPLE 3

(13) A heterogeneous polynuclear complex (dicarbonyl(N,N-diisopropyl-1,4-diazabutadiene)(tetracarbonylcobalt)methylruthenium (CoRu)) having ruthenium as a first transition metal and cobalt as a second transition metal was produced. The synthesis reaction formula is as described below. Hereinafter, the production process will be described in detail.

(14) ##STR00012##

(15) 1.71 g (5 mmol) of octacarbonyldicobalt and 0.23 g (10 mmol) of metal sodium were added in a flask containing 250 ml of tetrahydrofuran. The solution was stirred at room temperature for 24 hours, a solution obtained by dissolving 4.39 g (10 mmol) of dicarbonyliodo(N,N-diisopropyl-1,4-diazabutadiene)methylruthenium in 250 ml of tetrahydrofuran was then added, and the mixture was stirred at room temperature for 4 hours. After completion of the reaction, the reaction product was concentrated to obtain a muddy reaction mixture. The reaction mixture was extracted with hexane, and purified by column chromatography with alumina as a carrier and hexane as an eluent. Sublimation purification was performed to obtain 2.42 g (5.0 mmol) of dicarbonyl(N,N-diisopropyl-1,4-diazabutadiene)(tetracarbonylcobalt)methylruthenium (CoRu) as a specified substance (yield: 50%).

EXAMPLE 4

(16) A heterogeneous polynuclear complex (pentacarbonyl[dicarbonyl(ethyl)(N, N-diisopropyl-1,4-diazabutadiene)ruthenium]manganese (MnRu)) having ruthenium as a first transition metal and manganese as a second transition metal was produced. The synthesis reaction formula is as described below. Hereinafter, the production process will be described in detail.

(17) ##STR00013##

(18) 1.95 g (5 mmol) of decacarbonyldimanganese and 0.23 g (10 mmol) of metal sodium were added in a flask containing 250 ml of tetrahydrofuran. The solution was stirred at room temperature for 24 hours, a solution obtained by dissolving 4.53 g (10 mmol) of dicarbonylethyliodo(N,N-diisopropyl-1,4-diazabutadiene)ruthenium in 250 ml of tetrahydrofuran was then added, and the mixture was stirred at room temperature for 4 hours. After completion of the reaction, the reaction product was concentrated to obtain a muddy reaction mixture. The reaction mixture was extracted with hexane, and purified by column chromatography with alumina as a carrier and hexane as an eluent. Sublimation purification was performed to obtain 2.98 g (5.7 mmol) of pentacarbonyl[dicarbonyl(ethyl)(N,N-diisopropyl-1,4-diazabutadiene)ruthenium]manganese (MnRu) as a specified substance (yield: 57%).

(19) Evaluation of physical properties of heterogeneous polynuclear complex: Physical properties were evaluated by TG for the heterogeneous polynuclear complexes produced in Examples 1 and 4. Analysis was performed by observing a change in weight of a complex sample (5 mg) in heating of the sample at a temperature elevation rate of 5 C./min over a measurement temperature range, i.e. from room temperature to 450 C., under a nitrogen atmosphere in TG-DTA2000SA manufactured by BRUKER Corporation. For Example 1, analysis (TG measurement under reduced pressure) with a complex sample heated at a pressure of 5 Torr was performed. The results are shown in FIG. 1.

(20) FIG. 1 shows that the complexes in Examples 1 and 4 were vaporized and decomposed by heating at about 130 C., and thus these complexes had a low decomposition temperature, and were capable of forming a film at low temperature. The results of the TG measurement under reduced pressure showed that the complex in Example 1 was totally vaporized without being decomposed at a pressure during film formation.

(21) Film formation test: Next, a film formation test was conducted in which a composite metal thin film was formed by a CVD method with the complex produced in Example 1 as a raw material compound.

(22) The metal thin film was formed on a substrate (15 mm15 mm) with a silicon oxide film deposited on a silicon substrate by use of tetraethoxysilane (TEOS). As a film formation apparatus, a hot wall type thermal CVD apparatus was used. A reaction gas (hydrogen) was fed at a constant flow rate by use of a mass flow controller. Film formation conditions are as described below. The result of observing a cross-section of the metal thin film with a SEM is shown in FIG. 2.

(23) Substrate: SiO.sub.2

(24) Film formation temperature: 250 C.

(25) Sample temperature: 100 C.

(26) Film formation pressure: 5 torr

(27) Reaction gas (hydrogen) flow rate: 10 sccm

(28) Film formation time: 60 minutes

(29) The metal thin film formed in this way was glossy pure white, and had a thickness of 47.2 nm. FIG. 2 shows that the metal thin film formed on SiO.sub.2 had a smooth and uniform surface.

(30) M.sub.1/M.sub.2 ratio: the Ru/Mn ratio was analyzed as an abundance of metal elements by an X-ray photoelectron spectroscopy (XPS) method for the metal thin film formed as described above. As a measurement apparatus, KRATOS Axis Nova manufactured by Shimadzu Corporation was used. In this measurement, the thin film (thickness: 47.2 nm) was analyzed in a depth direction from the vicinity of the surface to the upper side of the vicinity of the interface with the SiO.sub.2 film. In the vicinity of the interface with the SiO.sub.2 film, actions of Si and O made it difficult to correctly analyze the Ru/Mn ratio, and the analysis was performed over a range where the impact was low. The results are shown in FIG. 3. The horizontal axis in FIG. 3 is approximately consistent with a thickness (47.2 nm) from the thin film surface to the upper side of the vicinity of the interface with the SiO.sub.2 film.

(31) FIG. 3 shows that both Ru and Mn were deposited in the metal thin film. The Ru/Mn ratio was almost constant (around 0.45) although it tended to be slightly high in the vicinity of the surface of the thin film.

INDUSTRIAL APPLICABILITY

(32) According to the present invention, a composite metal thin film can be formed from a single raw material by a chemical deposition method, and it is easy to make the thin film homogeneous and control quality of raw materials. Thus, the present invention can be applied to uses which employ a structure in which a plurality of metal layers are deposited, such as copper diffusion layers in semiconductor devices.