JP2006328526A - Method for depositing metallic film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for easily depositing a metallic film made into a seed layer upon burying metal, particularly copper into a trench in a substrate as an insulator by a plating process, further playing a roll as a barrier layer for preventing the migration of metal atoms to an insulation film and also having excellent adhesion with the insulator. <P>SOLUTION: In the method, a metallic compound on a substrate in which a film of at least one metallic compound selected from a cobalt compound, a ruthenium compound and a tungsten compound is deposited, is sublimed, the sublimed gas is fed to a substrate for depositing a metallic film, so as to be decomposed, thus the metallic film is deposited on the surface of the substrate. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for forming a metal film made of cobalt, ruthenium or tungsten. More specifically, the present invention relates to a method for forming the metal film suitable as a seed layer when copper is buried in a trench by a plating method.

In recent years, in electronic devices such as DRAM (Dynamic Random Access Memory), the structure of wiring and electrodes has been miniaturized and complicated for the purpose of higher performance, and the accuracy of these shapes needs to be improved. It has become like this.
In order to form electrodes and wiring in electronic devices, a trench is formed in a portion to be a wiring or an electrode on a substrate, a metal material to be a wiring or an electrode is embedded in the trench, and a surplus portion is subjected to chemical mechanical polishing. The method of removing by etc. is common.

Conventionally, copper having the advantage of having high conductivity has been widely used as an electrode material and wiring material in trench filling. When copper is used as a material, a physical method such as an evaporation method or a sputtering method or a plating method has been conventionally used as a trench filling method.
If a physical method such as vapor deposition or sputtering is used as the copper filling method in the trench, the trench opening width becomes smaller, and the trench aspect ratio (the trench depth is the minimum of the trench surface opening). When the value (divided by the distance) increases, the copper deposited in the region close to the trench opening closes the trench opening, resulting in a void (depleted portion not filled with copper) inside the trench. There is.

  On the other hand, the plating method has an advantage that copper can be buried with a high filling rate even in a trench having a small opening width and a large aspect ratio (see Patent Documents 1 and 2). However, when the substrate having the trench is an insulator having no conductivity (for example, a substrate made of silicon oxide or the like), the substrate surface should be an undercoat film before plating. It is necessary to form a conductive film (seed layer) in advance. Conventionally, copper by sputtering or electroless plating has been frequently used for this conductive film.

By the way, when an insulator represented by silicon oxide and copper come into contact, a phenomenon in which copper atoms migrate from a copper layer to an insulator is known. When migration of copper atoms occurs at the interface between copper and insulators in electronic devices, the electrical characteristics of the devices are impaired. Therefore, copper is used as a trench filling material in electronic devices, and the seed for copper filling is used. When using copper by sputtering or electroless plating as the layer, it was necessary to provide a barrier layer between the insulator and the seed layer. As a material constituting the barrier layer, tantalum, titanium, tantalum nitride, titanium nitride and the like are often used. However, since the adhesion between the material constituting the barrier layer and copper is not sufficient, an electronic device having a laminated structure of an insulator, a barrier layer, and copper has a low manufacturing yield and lacks reliability. There was a problem.
JP 2000-80494 A JP 2003-318258 A

  The present invention has been made in view of the above circumstances, and its purpose is to become a seed layer for embedding a metal, for example, copper by a plating method, in particular, in a trench of a substrate that is an insulator, and the substrate has a barrier layer. If not, it also serves as a barrier layer that prevents migration of metal atoms to the insulating film and has excellent adhesion to the insulator. If the substrate has a barrier layer, the barrier layer An object of the present invention is to provide a method for easily forming a film having excellent adhesion to a layer.

  According to the present invention, the above object of the present invention is, firstly, on a first substrate for forming a film of at least one metal selected from the group consisting of cobalt, ruthenium and tungsten, a cobalt compound, ruthenium. And sublimating the metal compound from a second substrate on which at least one metal compound selected from the group consisting of a compound and a tungsten compound is placed, and supplying the sublimation gas to the first substrate for decomposition, thereby This is achieved by a method for forming a metal film, which comprises forming the metal film on the surface of one substrate.

  A second object of the present invention is to form a first substrate for forming a film of at least one metal selected from the group consisting of cobalt, ruthenium, and tungsten, in the group consisting of a cobalt compound, ruthenium compound, and tungsten compound. Disposed to face the second substrate on which at least one metal compound film is formed, sublimates the metal compound on the second substrate, and supplies the sublimation gas to the first substrate for decomposition. Thus, the metal film is formed on the surface of the first substrate, and this is achieved by the metal film forming method.

  According to the present invention, thirdly, the above-mentioned problem of the present invention is that a cobalt compound, a ruthenium compound and a tungsten compound are formed on a substrate for forming a film of at least one metal selected from the group consisting of cobalt, ruthenium and tungsten. Forming a film of at least one metal compound selected from the group consisting of, sublimating the metal compound, and supplying the sublimation gas to another part on the substrate different from the part where the metal compound is sublimated. This is achieved by a method for forming a metal film, which decomposes and thereby forms the metal film on the surface of the substrate.

  According to the present invention, it becomes a seed layer when a metal, particularly copper, is buried in a trench of a substrate which is an insulator by plating, and also serves as a barrier layer for preventing migration of metal atoms to the insulating film, And the method of forming easily the metal film excellent in adhesiveness with an insulator is provided.

  Among the methods of the present invention, the first method is a cobalt compound, a ruthenium compound and a tungsten compound on a first substrate for forming a film of at least one metal selected from the group consisting of cobalt, ruthenium and tungsten. The metal compound is sublimated from a second substrate on which at least one metal compound selected from the group consisting of the above is mounted, and the sublimation gas is supplied to the first substrate for decomposition, whereby the first substrate The metal film is formed on the surface.

  Of the methods of the present invention, the second method comprises a substrate for forming a film of at least one metal selected from the group consisting of cobalt, ruthenium and tungsten, comprising a cobalt compound, a ruthenium compound and a tungsten compound. A substrate for disposing a metal substrate on at least one metal compound selected from the group, facing the second substrate, sublimating the metal compound on the second substrate, and forming the metal film on the sublimation gas And is decomposed, thereby forming a metal film on the surface of the substrate.

Examples of the material constituting the substrate on which the metal film is formed include glass, metal, metal nitride, silicon, resin, and insulating film.
Examples of the glass include quartz glass, borate glass, soda glass, and lead glass.
Examples of the metal include gold, silver, copper, nickel, aluminum, and iron.
Examples of the metal nitride include titanium nitride, tantalum nitride, and tungsten nitride.
Examples of the resin include polyethylene terephthalate, polyimide, and polyethersulfone.
Examples of the insulating film include silicon oxide, titanium oxide, zirconium oxide, hafnium oxide, tantalum oxide, niobium oxide, an insulating film called “SOG”, and a low dielectric constant insulating film formed by a CVD method. it can.
Examples of the silicon oxide include a thermal oxide film, a PETEOS (Plasma Enhanced TEOS) film, an HDP (High Density Plasma Enhanced TEOS) film, a BPSG (Boron Phosphorus Silicate) film, an FSG (Fluorine Doped Silicon) film, and the like. it can.

  The thermal oxide film is formed by placing silicon in a high temperature oxidizing atmosphere. The PETEOS film is formed by chemical vapor deposition using tetraethylorthosilicate (TEOS) as a raw material and using plasma as a promotion condition. The HDP film is formed by chemical vapor deposition using tetraethylorthosilicate (TEOS) as a raw material and using high-density plasma as a promotion condition. The BPSG film can be obtained by, for example, an atmospheric pressure CVD method or a low pressure CVD method. The FSG film is formed by chemical vapor deposition using high-density plasma as a promotion condition.

The above “SOG” is an abbreviation of “Spin on Glass”. In general, a liquid composition in which a silicate compound as a precursor is dissolved or dispersed in an organic solvent is applied to a substrate by spin coating or the like, and then heated. A low dielectric constant insulating film obtained by processing. Examples of the silicic acid compound as a precursor include silsesquioxane. As a commercial product of an insulating film called “SOG”, for example, Coral (manufactured by Nuvelus System), Aurora (manufactured by Nippon ASM Co., Ltd.), Nanoglass (manufactured by Honeywell), LKD (manufactured by Honeywell), etc. Can be mentioned.
Of the above, the material constituting the substrate is preferably silicon oxide, an insulating film called “SOG” or a low dielectric constant insulating film formed by a CVD method, more preferably silicon oxide, PETEOS film, BPSG film or An FSG film is more preferable.
The substrate may have a barrier layer formed on the surface thereof. Here, examples of the material constituting the barrier layer include tantalum, titanium, tantalum nitride, and titanium nitride. Among these, tantalum or tantalum nitride is preferable.

When the substrate on which the metal film is formed has a trench, the advantageous effects of the present invention are more exhibited. The trench is formed in a base made of the above-described material by a known method such as photolithography.
The trench may have any shape and size, but the trench opening width (minimum distance of the portion opened on the substrate surface) is 10 to 300 nm and the trench aspect ratio (trench depth). When the value obtained by dividing the thickness by the opening width of the trench is 3 or more, the advantageous effects of the present invention are maximized. The opening width of the trench can be further 10 to 200 nm, in particular 10 to 100 nm, in particular 10 to 50 nm. The aspect ratio of the trench can further be 3-40, in particular 5-25.

The second substrate is not particularly limited as long as it can form a film of the metal compound by a coating method and can withstand heating to sublimate the metal compound, and is the same as the substrate on which the metal film is formed. The material can be used.
Although there is no restriction | limiting in particular in the shape of a 2nd base | substrate, The shape which has a surface which meshes with at least one part of the part (surface) in which the metal film of the base | substrate in which a metal film is formed is formed is preferable.
Forming the metal compound film on the surface of the second substrate as described above can be performed by applying a composition containing the metal compound and the solvent to the second substrate and then removing the solvent. .

As the cobalt compound used for forming the cobalt film as the metal film, any cobalt compound having a sublimation property can be used. A cobalt compound having at least one selected from ligands is preferred.
As such a cobalt compound, the compound represented by either of following formula (1) thru | or (5) can be mentioned, for example.
L ¹ _c Co (CO) _d Y _e (1)
(Here, L ¹ is the following formula (1) -1
(CH ₃ ) _n Cp (1) -1
(Where Cp is a η ⁵ -cyclopentadienyl group and n is an integer from 0 to 5).
Or a coordination selected from the group represented by: indenyl group or 1,3-cyclooctadiene, 1,4-cyclooctadiene, 1,5-cyclooctadiene, 1,3-butadiene, norbornadiene and allyl Y is a halogen atom, a hydrogen atom, a methyl group or an ethyl group, c is 1 or 2, d is 0, 1, 2 or 4, e is 0 or 2, and c + d + e is 2, 3, 4 or 5, provided that when c is 2, L ¹ of 2 may be the same or different from each other. )

L ² _f Co ₂ (CO) _g R _h (2)
(Wherein the definition of L ² is the same as in the above formula (1) -1 or a coordination selected from 1,3-cyclohexadiene, 1,4-cyclohexadiene, allyl, norbornadiene and cyclooctene) And R is a halogen atom, PhC ::: CPh (where ::: means a triple bond), CCH ₃ , CH ₃ , CH ₂ , CH or CPh, and f is 0, 1, 2 or 4, g is 1, 2, 4, 6 or 8, h is 0, 1 or 2, and f + g + h is 4, 6, 7 or 8.)

Co ₃ (CO) ₉ CZ (3)
(Here, Z is a halogen atom.)

Co ₃ (CO) ₁₂ (4)

Co ₄ (CO) ₁₂ (5)

Examples of the complex represented by the formula (1) include cyclopentadienyl dicarbonyl cobalt, cyclopentadienyl carbonyl cobalt difluoride, cyclopentadienyl carbonyl cobalt dichlorite, cyclopentadienyl carbonyl cobalt dibromide, cyclo Pentadienylcarbonylcobalt cobalt iodide, bis (cyclopentadienyl) cobalt, bis (cyclopentadienyl) carbonylcobalt, bis (cyclopentadienyl) dicarbonylcobalt, methylcyclopentadienyldicarbonylcobalt, methylcyclo Pentadienylcarbonylcobalt difluoride, methylcyclopentadienylcarbonylcobalt dichlorite, methylcyclopentadienylcarbonylcobalt dibromide, methylcyclopent Dienylcarbonylcobalt diiodide, bis (methylcyclopentadienyl) cobalt, bis (methylcyclopentadienyl) carbonylcobalt, bis (methylcyclopentadienyl) dicarbonylcobalt, tetramethylcyclopentadienyldicarbonylcobalt , Tetramethylcyclopentadienylcarbonylcobalt difluoride, tetramethylcyclopentadienylcarbonylcobalt dichlorite, tetramethylcyclopentadienylcarbonylcobalt dibromide, tetramethylcyclopentadienylcarbonylcobalt diiodide, bis (tetra Methylcyclopentadienyl) cobalt, bis (tetramethylcyclopentadienyl) carbonylcobalt, bis (tetramethylcyclopentadienyl) dicarbo Rucobalt, 1,5-cyclooctadiene dicarbonyl cobalt, 1,5-cyclooctadiene carbonyl cobalt difluoride, 1,5-cyclooctadiene carbonyl cobalt dichloride, 1,5-cyclooctadiene carbonyl cobalt dibromide, , 5-cyclooctadienecarbonylcobalt diiodite, bis (1,5-cyclooctadiene) cobalt, bis (1,5-cyclooctadiene) carbonylcobalt, 1,3-cyclooctadienedicarbonylcobalt, 1, 3-cyclooctadiene carbonyl cobalt difluoride, 1,3-cyclooctadiene carbonyl cobalt dichloride, 1,3-cyclooctadiene carbonyl cobalt dibromide, 1,3-cyclooctadiene carbonyl cobalt diiod Dite, bis (1,3-cyclooctadiene) cobalt, bis (1,3-cyclooctadiene) carbonylcobalt, indenyldicarbonylcobalt, indenylcarbonylcobalt difluoride, indenylcarbonylcobalt dichloride, indenylcarbonyl cobalt dibromide, indenyl carbonyl cobalt di iodide, bis (indenyl) cobalt, bis (indenyl) carbonyl cobalt, eta ³ - allyl tricarbonyl cobalt eta ³ - allylcarbonyl cobalt difluoride, eta ³ - allylcarbonyl cobalt dichloride , eta ³ - allylcarbonyl cobalt dibromide, eta ³ - allylcarbonyl cobalt di iodide, bis (eta ³ - allyl) carbonyl cobalt, cyclopentadienyl (1,5-Sik Octadiene) cobalt, cyclopentadienyl (tetramethylcyclopentadienyl) cobalt, tetramethylcyclopentadienyl (1,5-cyclooctadiene) cobalt, cyclopentadienyl (methylcyclopentadienyl) cobalt, methylcyclo Pentadienyl (tetramethylcyclopentadienyl) cobalt, methylcyclopentadienyl (1,5-cyclooctadiene) cobalt, cyclopentadienyl (1,3-cyclooctadiene) cobalt, tetramethylcyclopentadienyl (1,3-cyclooctadiene) cobalt, methylcyclopentadienyl (1,3-cyclooctadiene) cobalt, cyclopentadienyl (cyclooctatetraenyl) cobalt, cyclopentadienyl (1,3-butadiene) Koval , Cyclopentadienyl (norbornadiene) cobalt, tetracarbonylcobalt hydride, cyclopentadienylcarbonylcobalt dihydride, methylcyclopentadienylcarbonylcobalt dihydride, tetramethylcyclopentadienylcarbonylcobalt dihydride, methyltetracarbonylcobalt, Examples thereof include ethyltetracarbonylcobalt.

Examples of the complex represented by the above formula (2) include bis (cyclopentadienyl) dicarbonyl dicobalt, bis (tetramethylcyclopentadienyl) dicarbonyl dicobalt, octacarbonyl dicobalt, and (norbornene). Hexacarbonyl dicobalt, cyclooctynehexacarbonyl dicobalt, bis (cyclopentadienyl) dimethyldicarbonyl dicobalt, tetra (η ³ -allyl) dicobalt diiodide, bis (1,3-cyclohexadienyl) tetracarbonyl Examples include dicobalt, bis (norbornene) tetracarbonyl dicobalt, bis (cyclopentadienyl) dicarbonyl dicobalt, and complexes represented by the following formulas (i) to (v).

  Examples of the complex represented by the above formula (3) include a complex represented by the following formula (vi).

Of these, bis (cyclopentadienyl) cobalt, bis (tetracyclopentadienyl) cobalt, bis (1,3-cyclooctadiene) cobalt, bis (1,5-cyclooctadiene) cobalt, bis (indenyl) ) Cobalt, cyclopentadienyl dicarbonyl cobalt, methylcyclopentadienyl dicarbonyl cobalt, tetramethylcyclopentadienyl dicarbonyl cobalt, (1,3-cyclooctadiene) dicarbonyl cobalt, (1,5-cycloocta) Diene) dicarbonylcobalt, indenyldicarbonylcobalt, η ³ -allyltricarbonylcobalt, cyclopentadienyl (1,3-cyclooctadiene) cobalt, cyclopentadienyl (1,5-cyclooctadiene) cobalt, Cyclopentadieny Preference is given to using ru (indenyl) cobalt, indenyl (1,3-cyclooctadiene) cobalt, indenyl (1,5-cyclooctadiene) cobalt or octacarbonyldicobalt.

These cobalt compounds can be used alone or in combination of two or more.
As the ruthenium compound used for forming the ruthenium film as the metal film, any ruthenium compound having a sublimation property can be used, but the ligand CO and π-coordinated configuration can be used. A ruthenium compound having at least one selected from ligands is preferred.
Examples of such ruthenium compounds include compounds represented by the following formulas (6) to (10).

(Here, X ¹ and X ² are each independently a hydrogen atom, a hydrocarbon group having 1 to 8 carbon atoms, a fluorine atom, a trifluoromethyl group, a pentafluoroethyl group, or the following formula (6) -1

(Here, R ¹ , R ² and R ³ are each independently a hydrocarbon group having 1 to 10 carbon atoms.)
It is group represented by these. However, X ¹ and X ² are not both hydrogen atoms. )
Ru (OCOR ⁴ ) ₃ (7)
(Here, R ⁴ is a trifluoromethyl group or a hydrocarbon group having 1 to 10 carbon atoms, and three R ^{4 s} may be the same as or different from each other.)
YRu (CO) ₃ (8)
(Y is a cyclopentadienyl, cyclohexadienyl, cycloheptadienyl, cyclooctadienyl, butadienyl, or 2,3-dimethyl-1,3-butadienyl group.)
YRuH _n L _m (9)
(Here, the definition of Y is the same as in the above formula (8), L is a carbonyl group, a methyl group or an ethenyl group, n is an integer of 1 to 4, and m is an integer of 0 to 2.) (However, n + m = 3 or 4 and when m is 2, two Ls may be the same or different.)
Ru _l (CO) _o (10)
(Where l is an integer from 1 to 9 and o is an integer from 1 to 50)
In the above formula (6), it should be understood that the cyclopentadienyl group having X ¹ or X ² is η ⁵ -coordinated. X ¹ or X ² is preferably a hydrogen atom, a hydrocarbon group having 1 to 8 carbon atoms, a trifluoromethyl group, the following formula (6) -1

(R ¹ , R ² and R ³ are each independently a hydrocarbon group having 1 to 10 carbon atoms), preferably a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, or a t-butyl group. Trifluoromethyl group, trimethylsilyl group, triethylsilyl group, tri-n-butoxysilyl group.
In the above formula (7), R ⁴ is a hydrocarbon group having 1 to 10 carbon atoms or a trifluoromethyl group, preferably an alkyl group having 1 to 8 carbon atoms or a trifluoromethyl group, more preferably a methyl group. , Ethyl group, 2-ethylhexyl group or trifluoromethyl group.
In the above formulas (8) and (9), Y represents a cyclopentadienyl group, a cyclohexadienyl group, a cycloheptadienyl group, a cyclooctadienyl group, a butadienyl group, or 2,3-dimethyl-1,3-butadienyl. It is a group. It should be understood that the cyclopentadienyl group is in the η ⁵ -configuration and the other groups in Y are in non-conjugated four-electron coordination.

  Y is preferably a cyclopentadienyl group, a 1,3-cyclohexadienyl group, a 1,4-cyclohexadienyl group, a 1,3-cyclooctadienyl group, a 1,4-cyclooctadienyl group, or 2, 3-dimethyl-1,3-butadienyl group. Of these, a cyclopentadienyl group, a 1,3-cyclohexadienyl group, a 1,4-cyclohexadienyl group, or a 2,3-dimethyl-1,3-butadienyl group is more preferable. More preferably, it is an enyl group or a 2,3-dimethyl-1,3-butadienyl group. In the above formula (9), L is a carbonyl group, a methyl group or an ethenyl group, preferably a carbonyl group or a methyl group, and more preferably a carbonyl group.

  Of the ruthenium compounds represented by the above formula (6), (7), (8), (9) or (10), represented by the above formula (6), (8), (9) or (10) Are preferred. Such ruthenium compounds include bis (cyclopentadienyl) ruthenium, bis (ethylcyclopentadienyl) ruthenium, bis (methylcyclopentadienyl) ruthenium, bis (t-butylcyclopentadienyl) ruthenium, bis (trifluoro Methylcyclopentadienyl) ruthenium, 1.4-cyclooctadienyltricarbonylruthenium, 1.3-cyclooctadienyltricarbonylruthenium, 1.4-cyclohexadienyltricarbonylruthenium, 1.3-cyclohexadienyl Tricarbonyl ruthenium, bis (trimethylsilylcyclopentadienyl) ruthenium, cyclopentadienyl ruthenium tetrahydride, 2,3-dimethyl-1,3-butadienyl ruthenium tetrahydride, cyclopentadi Nylcarbonyl ruthenium dihydride or 2,3-dimethyl-1,3-butadienylcarbonyl ruthenium dihydride, triruthenium dodecacarbonyl, ruthenium hexacarbonyl, ruthenium tetracarbonyl, diruthenium decacarbonyl, tetraruthenium hexadecacarbonyl, etc. It is done.

These compounds can be used alone or as a mixture of two or more chemical vapor deposition materials.
As the tungsten compound used for forming the tungsten film as the metal film, any tungsten compound having a sublimation property can be used. Tungsten compounds having at least one selected from ligands are preferred.

An example of such a tungsten compound is a compound represented by the following formula (11).

W (RCN) _n (CO) _6-n (11)
(Wherein R is a hydrocarbon group having 1 to 10 carbon atoms or a halogenated hydrocarbon group having 1 to 10 carbon atoms, and n is an integer of 0 to 6, provided that n is an integer of 2 to 6) And the plurality of R may be the same or different from each other.)
R in the above formula (11) is a hydrocarbon group having 1 to 10 carbon atoms or a halogenated hydrocarbon group having 1 to 10 carbon atoms, preferably a hydrocarbon group having 1 to 8 carbon atoms or 1 to 6 carbon atoms. A halogenated hydrocarbon group, more preferably a linear or branched alkyl group having 1 to 8 carbon atoms and a haloalkyl group having 1 to 6 carbon atoms. Examples of the hydrocarbon group include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, t-butyl group, phenyl group, trifluoromethyl group, 1,1. , 1-trifluoroethyl group, trichloromethyl group, 1,1,1-trichloroethyl group.

Moreover, it is an integer of n = 0-6 in said formula (11), Preferably it is n = 0-4, Most preferably, it is n = 0-3.
The tungsten compound is a D.I. P. Tate, W.W. R. Knipple and J.M. M.M. Augl, Inorganic. Chem. , Vol. 1, No. 1 2 (1962) 433, W.W. Strohmeir and G.M. Schonauer, Chem. Ber. , Vol. 94, (1961) 1346.

  Examples of the tungsten compound represented by the above formula (11) include hexa (acetonitrile) tungsten, penta (acetonitrile) carbonyltungsten, tetra (acetonitrile) dicarbonyltungsten, tri (acetonitrile) tricarbonyltungsten, di (acetonitrile) tetracarbonyl. Tungsten, (acetonitrile) pentacarbonyltungsten, hexa (propionitrile) tungsten, penta (propionitrile) carbonyltungsten, tetra (propionitrile) dicarbonyltungsten, tri (propionitrile) tricarbonyltungsten, di (propio) Nitrile) tetracarbonyltungsten, (propionitrile) pentacarbonyltungsten, hexa (butyronitrile) tan Sten, penta (butyronitrile) carbonyltungsten, tetra (butyronitrile) dicarbonyltungsten, tri (butyronitrile) tricarbonyltungsten, di (butyronitrile) tetracarbonyltungsten, (butyronitrile) pentacarbonyltungsten, hexa (isobutyronitrile) tungsten, penta (Isobutyronitrile) carbonyltungsten, tetra (isobutyronitrile) dicarbonyltungsten, tri (isobutyronitrile) tricarbonyltungsten, di (isobutyronitrile) tetracarbonyltungsten, (isobutyronitrile) pentacarbonyl Tungsten, hexa (valeronitrile) tungsten, penta (valeronitrile) carbonyltungsten, tetra (valeroni) Ril) dicarbonyltungsten, tri (valeronitrile) tricarbonyltungsten, di (valeronitrile) tetracarbonyltungsten, (valeronitrile) pentacarbonyltungsten, hexa (valeronitrile) tungsten, penta (valeronitrile) carbonyltungsten, tetra (valero) Nitrile) dicarbonyltungsten, tri (valeronitrile) tricarbonyltungsten, di (valeronitrile) tetracarbonyltungsten, (valeronitrile) pentacarbonyltungsten, hexa (trimethylacetonitrile) tungsten, penta (trimethylacetonitrile) carbonyltungsten, tetra (trimethyl) Acetonitrile) dicarbonyltungsten, tri (trimethylacetonitrile) tri Carbonyl tungsten, di (trimethylacetonitrile) tetracarbonyltungsten, (trimethylacetonitrile) pentacarbonyltungsten, hexa (benzonitrile) tungsten, penta (benzonitrile) carbonyltungsten, tetra (benzonitrile) dicarbonyltungsten, tri (benzonitrile) tri Carbonyl tungsten, di (benzonitrile) tetracarbonyl tungsten, (benzonitrile) pentacarbonyl tungsten, hexa (trichloroacetonitrile) tungsten, penta (trichloroacetonitrile) carbonyl tungsten, tetra (trichloroacetonitrile) dicarbonyl tungsten, tri (trichloroacetonitrile) tri Carbonyl tungsten, di (trichloro Acetonitrile) tetracarbonyl tungsten, it may be mentioned (trichloroacetonitrile) pentacarbonyl tungsten, tungsten hexacarbonyl.

  Of these, tetra (acetonitrile) dicarbonyltungsten, tri (acetonitrile) tricarbonyltungsten, di (acetonitrile) tetracarbonyltungsten, tetra (propionitrile) dicarbonyltungsten, tri (propionitrile) tricarbonyltungsten, di ( Propionitrile) tetracarbonyltungsten, tetra (valeronitrile) dicarbonyltungsten, tri (valeronitrile) tricarbonyltungsten, di (valeronitrile) tetracarbonyltungsten, tetra (trimethylacetonitrile) dicarbonyltungsten, tri (trimethylacetonitrile) tri Carbonyl tungsten, di (trimethylacetonitrile) tetracarbonyl tungsten, hexacarbonyl Nungsten is preferred, tetra (acetonitrile) dicarbonyltungsten, tri (acetonitrile) tricarbonyltungsten, di (acetonitrile) tetracarbonyltungsten, tri (propionitrile) tricarbonyltungsten, tetra (valeronitrile) dicarbonyltungsten, tri (valero) Nitrile) tricarbonyltungsten, di (valeronitrile) tetracarbonyltungsten, hexacarbonyltungsten are more preferred, and tri (acetonitrile) tricarbonyltungsten, tri (propionitrile) tricarbonyltungsten, tetra (valeronitrile) dicarbonyltungsten, (Valeronitrile) tricarbonyltungsten and hexacarbonyltungsten are particularly preferred.

These compounds can be used alone or in admixture of two or more.
Examples of the solvent used when applying the cobalt compound include aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, alcohols, ethers, ketones, and halogenated hydrocarbons.

Examples of the aliphatic hydrocarbon include n-hexane, n-heptane, n-octane, n-nonane, n-decane and the like;
Examples of the alicyclic hydrocarbon include cyclohexane, cycloheptane, cyclooctane and the like;
Examples of the aromatic hydrocarbon include benzene, toluene, xylene and the like;
Examples of the alcohol include methanol, ethanol, propanol, butanol, isopropanol and the like;
Examples of the ether include diethyl ether, dipropyl ether, dibutyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, tetrahydrofuran, tetrahydropyran, p- Dioxane and the like;
Examples of the ketone include acetone, methyl ethyl ketone, cyclohexanone, and diethyl ketone.
Examples of the halogenated hydrocarbon include methylene chloride, tetrachloroethane, chloromethane, chlorobenzene, and the like.

  Among these, it is preferable to use an aliphatic hydrocarbon, an aromatic hydrocarbon or an alcohol, and it is more preferable to use hexane, heptane, cyclohexane, toluene or isopropanol.

Preferred solvents for the ruthenium compound are alcohols and ketones, among which methanol, ethanol, propyl alcohol, butanol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, acetone and methyl ethyl ketone can be mentioned.
Preferred solvents for tungsten compounds are alcohols and halogenated hydrocarbons, including methanol, ethanol, propyl alcohol, butanol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, methylene chloride, tetrachloroethane, chloromethane. be able to.

A solvent can use only 1 type and can also mix and use 2 or more types.
The composition containing these metal compounds and solvents may contain a surfactant, a silane coupling agent, a polymer, or the like, if necessary, in addition to the above metal compounds and solvents.
The concentration of the metal compound contained in the composition containing the metal compound and the solvent is preferably 0.1 to 50% by weight, more preferably 1 to 30% by weight.

A metal compound film is formed on the second substrate by applying a composition containing a metal compound and a solvent on the second substrate and then removing the solvent.
An appropriate method can be used when applying the composition to the second substrate. Specific examples of the coating method that can be employed here include spin coating, dip coating, curtain coating, roll coating, spray coating, ink jet, and printing.

After applying the composition, the solvent is then removed. In order to remove the solvent from the coating film, the second substrate after coating is preferably at a temperature of 0 to 100 ° C., more preferably 10 to 50 ° C., preferably 0.1 to 60 minutes, more preferably 1 It can be carried out by leaving for ~ 20 minutes.
As the atmosphere for the coating and solvent removal, an atmosphere of an inert gas such as nitrogen, argon, or helium is preferable.
The thickness of the metal compound film formed on the second substrate should be appropriately adjusted depending on the thickness of the metal film to be formed, but the value after removal of the solvent is preferably 10 nm to 10 μm. More preferably, it is 100 nm to 5 μm.

Next, the base on which the metal film is formed and the second base on which the metal compound film is formed are arranged, for example, to face each other. Here, the portion on which the metal film is to be formed in the substrate on which the metal film is to be formed and the portion on which the metal compound film is formed in the second substrate should be arranged to face each other. The distance between the two substrates is preferably 0.1 mm to 10 mm, more preferably 0.5 mm to 2 mm.
Next, the metal compound film on the second substrate is irradiated with heat rays to sublimate the metal compound.
As a heat source that can be used for irradiation with heat rays, for example, a heater, an infrared lamp, an infrared laser, a semiconductor laser, sunlight, and the like can be used, and radiant heat from a substrate that forms a heated metal film described later. Also good. In order to irradiate only a specific part of the film with heat rays, the heat rays may be irradiated through a mask having a pattern.

The temperature of the heat treatment should be a temperature at which the metal compound can be sublimated, and should be appropriately set according to the type of the metal compound to be used. As a guideline, the metal compound film on the second substrate is used. The surface temperature reached is preferably 50 ° C. or higher, more preferably 50 to 500 ° C., and still more preferably 100 to 300 ° C.
The metal compound sublimated from the second substrate is converted into metal by contacting the substrate on which the metal film is formed, and is deposited on the substrate to form a metal film. The substrate on which the metal film is formed is preferably heated in advance. Here, the temperature of the substrate on which the metal film is formed should be equal to or higher than the temperature at which the metal compound can be decomposed, and should be appropriately set depending on the type of metal compound to be used, but preferably 50 to 1000 ° C. It is.

When the metal compound is a cobalt compound, the temperature is preferably 100 to 300 ° C, more preferably 100 to 250 ° C, and still more preferably 120 to 220 ° C.
When the metal compound is a ruthenium compound, it is preferably 90 to 350 ° C, more preferably 100 to 300 ° C, and still more preferably 100 to 250 ° C.
When the metal compound is a tungsten compound, the temperature is preferably 100 to 350 ° C, more preferably 120 to 300 ° C, and still more preferably 120 to 250 ° C.
In addition, when the metal compound is a mixture of two or three compounds, the temperature range shown in Table 1 below is recommended as well.

The atmosphere when the sublimation of the metal compound by irradiating the second substrate with heat rays and the substrate on which the sublimate is formed as a metal film is decomposed by contact is to be an inert atmosphere or a vacuum. Is preferred. The inert atmosphere can be obtained with an inert gas. Examples of the inert gas include nitrogen, helium, and argon. When an inert atmosphere is adopted as the atmosphere for heat ray irradiation, the pressure is preferably normal pressure.
Thus, a metal film is formed on the substrate on which the metal film is formed. The film thickness of the metal film is preferably 1 nm to 1000 nm, more preferably 5 nm to 100 nm.

Of the methods of the present invention, the third method is a method of forming a metal compound film on a substrate on which a metal film is formed, sublimating the metal compound, and sublimating the sublimation gas into a sublimated gas portion. Is a method of forming a metal film on the surface of the substrate by supplying it to another part on the different substrate and decomposing it.
The substrate on which the metal film that can be used in the third method is formed is the same as in the first and second methods.
A composition containing a metal compound and a solvent used when forming a metal compound film on a substrate, a coating method and a solvent removing method are also the same as those in the first method, and the metal compound film is formed on the second substrate. It can be carried out in the same manner as in the case of forming.

  In the third method, the metal compound is sublimated from the metal compound film formed on the substrate, and the sublimation gas is supplied to another portion on the substrate different from the portion where the sublimation gas is sublimated for decomposition. Can be achieved by heating at 100 ° C. to 200 ° C. for 1 to 60 minutes with an infrared lamp or the like in an inert gas atmosphere.

Example 1
<Preparation of composition containing substrate and cobalt compound and solvent>
As a substrate on which a cobalt film is formed (first substrate), a silicon substrate having a diameter of 4 inches having a tantalum nitride film having a thickness of 10 nm on one surface was prepared.
A silicon substrate having a diameter of 4 inches was prepared as the second substrate.
As a composition containing a cobalt compound and a solvent, a solution prepared by dissolving 10 g of octacarbonyl dicobalt in 90 g of isopropyl alcohol was prepared.
In a nitrogen atmosphere, the isopropyl alcohol solution of octacarbonyl dicobalt is applied to one side of a silicon substrate, which is the second substrate, by spin coating, and then placed at 25 ° C. for 5 minutes to obtain a thickness of 10 μm. A film of the cobalt compound was formed.

<Formation of cobalt film>
Next, the surface of the first substrate having tantalum nitride and the surface of the second substrate having a cobalt compound film were arranged to face each other at a distance of 1.0 mm in a nitrogen atmosphere. The back surface of the first substrate was brought into contact with the hot plate surface, and the first substrate was heated to 200 ° C. The cobalt compound on the second substrate was heated and sublimated by the radiant heat from the heated first substrate, and a silver-white film was formed on the first substrate. When SIMS analysis was performed on this film, it was found that this film was cobalt metal. The cobalt film had a thickness of 20 nm and a specific resistance of 12 μΩcm.

<Performance test as seed layer>
Next, the substrate having the cobalt film formed as described above is subjected to copper plating using a copper sulfate electrolytic plating solution at a plating temperature of 18 ° C., a plating current of 2.83 A, and a plating time of 5 minutes. A copper layer having a thickness of 1.2 μm was formed on the cobalt film. When this copper layer was subjected to a cross-cut peel test in accordance with JIS-5400, there was no peel of 100 cross-cuts and the adhesion was very good.

Example 2
A silicon substrate having a diameter of 8 inches was prepared in which a tantalum nitride film having a thickness of 10 nm including the inside of the trench was formed on a surface having a linear trench (aspect ratio 5) having a width of 150 nm and a depth of 750 nm on one side.
As the substrate on which the cobalt film is formed (first substrate), except that the above silicon substrate is used, the same procedure as in <Cobalt film formation> in Example 1 is performed. A membrane was obtained. When SIMS analysis was performed on this film, it was found that this film was cobalt metal. The cobalt film had a thickness of 25 nm. However, this value is a value measured for a plane portion other than the trench. The substrate after the formation of the cobalt film was cut in a direction perpendicular to the length direction of the trench, and the cross section was observed with a scanning microscope. As a result, the cobalt film was uniformly formed even inside the trench. This electron micrograph is shown in FIG.
Further, for the substrate with trench in which a cobalt film was formed in the same manner as described above,

In the same manner as in <Performance test as seed layer>, a copper layer having a thickness of 1.2 μm was formed on the cobalt film. However, the thickness of the copper layer is a value measured for a planar portion other than the trench. The substrate was cut in a direction perpendicular to the length of the trench and the cross section was observed with a scanning electron microscope. As a result, no voids were found inside the trench and the embedding property was good.

Example 3
<Formation of ruthenium film>
As a substrate on which a ruthenium film is formed, a silicon substrate having a diameter of 4 inches having a tantalum nitride film having a thickness of 10 nm on one surface was prepared. In a nitrogen atmosphere, 3 g of triruthenium dodecacarbonyl was measured in a quartz boat-type container. The quartz container was then heated to 150 ° C. Ruthenium compound vapor was generated from the heated container, and this vapor was brought into contact with the substrate surface heated to 200 ° C., and a silver-white film was formed on the substrate. When this film was subjected to ESCA analysis, it was found that this film was metal ruthenium. The metal ruthenium film had a thickness of 25 nm and a specific resistance of 16 μΩcm.

<Performance test as seed layer>
Next, the base having the ruthenium film formed as described above is subjected to copper plating using a copper sulfate electrolytic plating solution at a plating temperature of 18 ° C., a plating current of 2.83 A, and a plating time of 5 minutes. A copper layer having a thickness of 1.2 μm was formed on the ruthenium film. When this copper layer was subjected to a cross-cut peel test in accordance with JIS-5400, there was no peel of 100 cross-cuts and the adhesion was very good.

<Formation of ruthenium film on trench substrate>
A silicon substrate having a diameter of 8 inches was prepared in which a tantalum nitride film having a thickness of 10 nm including the inside of the trench was formed on a surface having a linear trench (aspect ratio 5) having a width of 150 nm and a depth of 750 nm on one side.
As the substrate (first substrate) on which the ruthenium film is formed, the above-described <Ruthenium film formation> was carried out except that the above silicon substrate was used, and a silver white film was obtained on the substrate. When this film was subjected to ESCA analysis, it was found that this film was metal ruthenium. The thickness of the metal ruthenium film was 32 nm. However, this value is a value measured for a plane portion other than the trench. The base after the ruthenium film was formed was cut in a direction perpendicular to the length direction of the trench, and the cross section was observed with a scanning microscope. As a result, the ruthenium film was uniformly formed even inside the trench.
For the substrate with a trench on which a ruthenium film was formed in the same manner as described above, a copper layer having a thickness of 1.2 μm was formed on the ruthenium film in the same manner as in the above <performance test as seed layer>. However, the thickness of the copper layer is a value measured for a planar portion other than the trench. The substrate was cut in a direction perpendicular to the length of the trench and the cross section was observed with a scanning electron microscope. As a result, no voids were found inside the trench and the embedding property was good.

Example 4
<Preparation of composition containing substrate and ruthenium compound and solvent>
As a base (first base) on which a ruthenium film is formed, a silicon substrate having a diameter of 4 inches having a tantalum nitride film having a thickness of 10 nm on one surface was prepared.
A silicon substrate having a diameter of 4 inches was prepared as the second substrate.
As a composition containing a ruthenium compound and a solvent, a solution in which 10 g of triruthenium dodecacarbonyl was dissolved in 90 g of acetone was prepared.
In a nitrogen atmosphere, the acetone solution of triruthenium dodecacarbonyl was applied to one side of a silicon substrate as a second substrate by a spin coating method, and then placed at 25 ° C. for 5 minutes, whereby a thickness of 12 μm was obtained. A ruthenium compound film was formed.

<Formation of ruthenium film>
Next, the surface of the first substrate having tantalum nitride and the surface of the second substrate having a ruthenium compound film were arranged to face each other at a distance of 1.0 mm in a nitrogen atmosphere. The back surface of the first substrate was brought into contact with the hot plate surface, and the first substrate was heated to 150 ° C. The ruthenium compound on the second substrate was heated and sublimated by the radiant heat from the heated first substrate, and a silver-white film was formed on the first substrate. When this film was subjected to ESCA analysis, it was found that this film was metal ruthenium. The metal ruthenium film had a thickness of 30 nm and a specific resistance of 17 μΩcm.

<Performance test as seed layer>
Next, the base having the ruthenium film formed as described above is subjected to copper plating using a copper sulfate electrolytic plating solution at a plating temperature of 18 ° C., a plating current of 2.83 A, and a plating time of 5 minutes. A copper layer having a thickness of 1.2 μm was formed on the ruthenium film. When this copper layer was subjected to a cross-cut peel test in accordance with JIS-5400, there was no peel of 100 cross-cuts and the adhesion was very good.

<Formation of ruthenium film on trench substrate>
A silicon substrate having a diameter of 8 inches was prepared in which a tantalum nitride film having a thickness of 10 nm including the inside of the trench was formed on a surface having a linear trench (aspect ratio 5) having a width of 150 nm and a depth of 750 nm on one side.
As the substrate (first substrate) on which the ruthenium film is formed, the above-described <Ruthenium film formation> is performed except that the silicon substrate is used, and a silver white film is formed on the first substrate. Obtained. When this film was subjected to ESCA analysis, it was found that this film was metal ruthenium. The thickness of the metal ruthenium film was 32 nm. However, this value is a value measured for a plane portion other than the trench. The base after the ruthenium film was formed was cut in a direction perpendicular to the length direction of the trench, and the cross section was observed with a scanning microscope. As a result, the ruthenium film was uniformly formed even inside the trench.

  For the substrate with a trench on which a ruthenium film was formed in the same manner as described above, a copper layer having a thickness of 1.2 μm was formed on the ruthenium film in the same manner as in the above <performance test as seed layer>. However, the thickness of the copper layer is a value measured for a planar portion other than the trench. The substrate was cut in a direction perpendicular to the length of the trench and the cross section was observed with a scanning electron microscope. As a result, no voids were found inside the trench and the embedding property was good.

Example 5
<Formation of tungsten film>
A 4-inch diameter silicon substrate having a 10 nm thick tantalum nitride film on one surface was prepared as a substrate on which a tungsten film was formed. In a nitrogen atmosphere, 3 g of tungsten hexacarbonyl was weighed into a quartz boat-type container. The quartz container was then heated to 180 ° C. A tungsten compound vapor was generated from the heated container, and the vapor was brought into contact with the surface of the substrate heated to 250 ° C., and a silver white film was formed on the substrate. When this film was subjected to ESCA analysis, it was found that this film was metallic tungsten. The metal tungsten film had a thickness of 20 nm and a specific resistance of 18 μΩcm.

<Performance test as seed layer>
Next, the substrate having the tungsten film formed as described above is subjected to copper plating using a copper sulfate electrolytic plating solution at a plating temperature of 18 ° C., a plating current of 2.83 A, and a plating time of 5 minutes. A copper layer having a thickness of 1.2 μm was formed on the tungsten film. When this copper layer was subjected to a cross-cut peel test in accordance with JIS-5400, there was no peel of 100 cross-cuts and the adhesion was very good.

<Formation of tungsten film on trench substrate>
A silicon substrate having a diameter of 8 inches was prepared in which a tantalum nitride film having a thickness of 10 nm including the inside of the trench was formed on a surface having a linear trench (aspect ratio 5) having a width of 150 nm and a depth of 750 nm on one side.
The same procedure as in <Tungsten film formation> was performed except that the above silicon substrate was used as the substrate on which the tungsten film was formed, and a silver white film was obtained on the substrate. When this film was subjected to ESCA analysis, it was found that this film was tungsten metal. The thickness of the tungsten film was 15 nm (however, this value is a value measured for a planar portion other than the trench). The substrate after forming the tungsten film was cut in a direction perpendicular to the length direction of the trench, and the cross section was observed with a scanning microscope. As a result, the tungsten film was uniformly formed even inside the trench.

  For the substrate with a trench in which a tungsten film was formed in the same manner as described above, a copper layer having a thickness of 1.2 μm was formed on the tungsten film in the same manner as in the above <Performance test as seed layer>. However, the thickness of the copper layer is a value measured for a planar portion other than the trench. The substrate was cut in a direction perpendicular to the length of the trench and the cross section was observed with a scanning electron microscope. As a result, no voids were found inside the trench and the embedding property was good.

Example 6
<Preparation of composition containing substrate, tungsten compound and solvent>
As a substrate (first substrate) on which a tungsten film is formed, a silicon substrate having a diameter of 4 inches having a tantalum nitride film having a thickness of 10 nm on one surface was prepared.
A silicon substrate having a diameter of 4 inches was prepared as the second substrate.
As a composition containing a tungsten compound and a solvent, a solution in which 5 g of tungsten hexacarbonyl was dissolved in 90 g of methylene chloride was prepared.
In a nitrogen atmosphere, the tungsten hexacarbonyl methylene chloride solution was applied to one side of the silicon substrate as the second substrate by a spin coating method, and then placed at 25 ° C. for 5 minutes, whereby a thickness of 5 μm was obtained. A tungsten compound film was formed.

<Formation of tungsten film>
Next, the surface of the first substrate having tantalum nitride and the surface of the second substrate having a tungsten compound film were arranged to face each other at a distance of 1.0 mm in a nitrogen atmosphere. The back surface of the first substrate was brought into contact with the hot plate surface, and the first substrate was heated to 200 ° C. The tungsten compound on the second substrate was heated and sublimated by the radiant heat from the heated first substrate, and a silver-white film was formed on the first substrate. When this film was subjected to ESCA analysis, it was found that this film was tungsten metal. The tungsten film had a thickness of 12 nm and a specific resistance of 20 μΩcm.

<Performance test as seed layer>
Next, the substrate having the tungsten film formed as described above is subjected to copper plating using a copper sulfate electrolytic plating solution at a plating temperature of 18 ° C., a plating current of 2.83 A, and a plating time of 5 minutes. A copper layer having a thickness of 1.2 μm was formed on the tungsten film. When this copper layer was subjected to a cross-cut peel test in accordance with JIS-5600-5-6, no peeled eyes were found out of 100 cross-cuts, and the adhesion was extremely good.

<Formation of tungsten film on trench substrate>
A silicon substrate having a diameter of 8 inches was prepared in which a tantalum nitride film having a thickness of 10 nm including the inside of the trench was formed on a surface having a linear trench (aspect ratio 5) having a width of 150 nm and a depth of 750 nm on one side.
As the substrate (first substrate) on which the tungsten film is formed, the above-described <Sungsten film formation> is performed except that the silicon substrate is used, and a silver-white film is formed on the first substrate. Obtained. When this film was subjected to ESCA analysis, it was found that this film was tungsten metal. The thickness of this tungsten film was 15 nm. However, this value is a value measured for a plane portion other than the trench. The substrate after forming the tungsten film was cut in a direction perpendicular to the length direction of the trench, and the cross section was observed with a scanning microscope. As a result, the tungsten film was uniformly formed even inside the trench.

  For the substrate with a trench in which a tungsten film was formed in the same manner as described above, a copper layer having a thickness of 1.2 μm was formed on the tungsten film in the same manner as in the above <Performance test as seed layer>. However, the thickness of the copper layer is a value measured for a planar portion other than the trench. The substrate was cut in a direction perpendicular to the length of the trench and the cross section was observed with a scanning electron microscope. As a result, no voids were found inside the trench and the embedding property was good.

Example 7
<Formation of cobalt / tungsten alloy film>
A 4-inch diameter silicon substrate having a 10 nm thick tantalum nitride film on one surface was prepared as a substrate on which a cobalt / tungsten alloy film was formed. In a nitrogen atmosphere, 2 g of tungsten oxacarbonyl and 1.8 g of dicobalt octacarbonyl were weighed in a quartz boat-type container. The quartz container was then heated to 200 ° C. Cobalt / tungsten compound vapor was generated from the heated container, and the vapor was brought into contact with the surface of the substrate heated to 300 ° C. to form a silver-white film on the substrate. When this film was subjected to ESCA analysis, it was found that this film was a cobalt / tungsten alloy. The metal cobalt / tungsten alloy film had a thickness of 26 nm and a specific resistance of 18 μΩcm.

<Performance test as seed layer>
Next, for the substrate having the cobalt / tungsten alloy film formed as described above, a copper sulfate electrolytic plating solution was used, and the copper was plated under the conditions of a plating temperature of 18 ° C., a plating current of 2.83 A, and a plating time of 5 minutes. Plating was performed to form a copper layer having a thickness of 1.5 μm on the cobalt / tungsten alloy film. When this copper layer was subjected to a cross-cut peel test in accordance with JIS-5400, there was no peel of 100 cross-cuts and the adhesion was very good.

<Formation of cobalt / tungsten alloy film on trench substrate>
A silicon substrate having a diameter of 8 inches was prepared in which a tantalum nitride film having a thickness of 10 nm including the inside of the trench was formed on a surface having a linear trench (aspect ratio 5) having a width of 150 nm and a depth of 750 nm on one side.
The same procedure as in <Cobalt / tungsten alloy film formation> was performed except that the above silicon substrate was used as the substrate on which the cobalt / tungsten alloy film was formed, and a silver white film was obtained on the substrate. When this film was subjected to ESCA analysis, it was found that this film was a cobalt / tungsten alloy. The cobalt / tungsten alloy film had a thickness of 24 nm. However, this value is a value measured for a plane portion other than the trench. The substrate after the formation of the cobalt / tungsten alloy film was cut in a direction perpendicular to the length direction of the trench, and the cross section was observed with a scanning microscope. As a result, the cobalt / tungsten alloy film was uniformly formed even inside the trench. It was.

  Further, for the substrate with a trench in which a cobalt / tungsten alloy film was formed in the same manner as described above, a copper layer having a thickness of 1.2 μm was formed on the cobalt / tungsten alloy film in the same manner as in the above <performance test as seed layer>. Formed. However, the thickness of the copper layer is a value measured for a planar portion other than the trench. The substrate was cut in a direction perpendicular to the length of the trench and the cross section was observed with a scanning electron microscope. As a result, no voids were found inside the trench and the embedding property was good.

Example 8
<Preparation of composition containing substrate and cobalt / tungsten alloy compound and solvent>
As a substrate (first substrate) on which a cobalt / tungsten alloy film is formed, a silicon substrate having a diameter of 4 inches having a tantalum nitride film having a thickness of 10 nm on one surface was prepared.
A silicon substrate having a diameter of 4 inches was prepared as the second substrate.
As a composition containing a cobalt / tungsten compound and a solvent, a solution prepared by dissolving 2.5 g of tungsten oxacarbonyl and 2.0 g of dicobalt octacarbonyl in 100 g of isopropyl alcohol was prepared.
In a nitrogen atmosphere, the cobalt / tungsten compound isopropyl alcohol solution was applied to one side of a silicon substrate as a second substrate by a spin coating method, and then placed at 25 ° C. for 5 minutes to obtain a thickness of 5 μm. A cobalt / tungsten compound film was formed.

<Formation of cobalt / tungsten alloy film>
Next, the surface of the first substrate having tantalum nitride and the surface of the second substrate having a cobalt / tungsten alloy compound film were arranged to face each other at a distance of 1.0 mm in a nitrogen atmosphere. The back surface of the first substrate was brought into contact with the hot plate surface, and the first substrate was heated to 200 ° C. The cobalt / tungsten alloy compound on the second substrate was heated and sublimated by the radiant heat from the heated first substrate, and a silver-white film was formed on the first substrate. An ESCA analysis of this film revealed that this film was a cobalt / tungsten alloy metal. The cobalt / tungsten alloy film had a thickness of 32 nm and a specific resistance of 18 μΩcm.

<Performance test as seed layer>
Next, for the substrate having the cobalt / tungsten alloy film formed as described above, a copper sulfate electrolytic plating solution was used, and the copper was plated under the conditions of a plating temperature of 18 ° C., a plating current of 2.83 A, and a plating time of 5 minutes. Plating was performed to form a copper layer having a thickness of 1.2 μm on the cobalt / tungsten alloy film. When this copper layer was subjected to a cross-cut peel test in accordance with JIS-5400, there was no peel of 100 cross-cuts and the adhesion was very good.

<Formation of cobalt / tungsten alloy film on trench substrate>
A silicon substrate having a diameter of 8 inches was prepared in which a tantalum nitride film having a thickness of 10 nm including the inside of the trench was formed on a surface having a linear trench (aspect ratio 5) having a width of 150 nm and a depth of 750 nm on one side.
As the base (first base) on which the cobalt / tungsten alloy film is formed, the above-described <Cobalt / tungsten alloy film formation> is performed except that the above silicon substrate is used. A silvery white film was obtained. When this film was subjected to ESCA analysis, it was found that this film was a cobalt / tungsten alloy metal. The cobalt / tungsten alloy film had a thickness of 29 nm. However, this value is a value measured for a plane portion other than the trench. The substrate after the formation of the cobalt / tungsten alloy film was cut in a direction perpendicular to the length direction of the trench, and the cross section was observed with a scanning microscope. As a result, the cobalt / tungsten alloy film was uniformly formed even inside the trench. It was.

  Further, for the substrate with a trench in which a cobalt / tungsten alloy film is formed in the same manner as described above, a copper layer having a thickness of 1.5 μm is formed on the cobalt / tungsten alloy film in the same manner as in the above <performance test as seed layer>. Formed. However, the thickness of the copper layer is a value measured for a planar portion other than the trench. The substrate was cut in a direction perpendicular to the length of the trench and the cross section was observed with a scanning electron microscope. As a result, no voids were found inside the trench and the embedding property was good.

The electron micrograph of the base | substrate after cobalt film formation obtained in Example 2 which shows formation of the cobalt film to the base | substrate which has a trench.

Claims (8)

  At least one metal compound selected from the group consisting of a cobalt compound, ruthenium compound and tungsten compound is placed on the first substrate for forming a film of at least one metal selected from the group consisting of cobalt, ruthenium and tungsten. A metal, wherein the metal compound is sublimated from the second substrate, and the sublimation gas is supplied to the first substrate for decomposition, thereby forming the metal film on the surface of the first substrate. Method for forming a film.   Forming a first substrate for forming at least one metal film selected from the group consisting of cobalt, ruthenium and tungsten with a film of at least one metal compound selected from the group consisting of cobalt compounds, ruthenium compounds and tungsten compounds Disposed opposite the second substrate, sublimates the metal compound on the second substrate, supplies the sublimation gas to the first substrate, decomposes it, and thereby the surface of the first substrate A method for forming a metal film, comprising forming a metal film on the substrate.   A film of at least one metal compound selected from the group consisting of a cobalt compound, ruthenium compound and tungsten compound is formed on a substrate for forming a film of at least one metal selected from the group consisting of cobalt, ruthenium and tungsten. Sublimating the metal compound, and supplying the sublimation gas to another portion on the substrate different from the portion where the metal compound sublimated to decompose, thereby forming the metal film on the surface of the substrate. A method for forming a metal film.   The method according to any one of claims 1 to 3, wherein the substrate for forming a film of at least one metal selected from the group consisting of cobalt, ruthenium and tungsten has a trench.   The at least 1 metal compound chosen from the group which consists of a cobalt compound, a ruthenium compound, and a tungsten compound has at least 1 sort (s) selected from the ligand CO and the ligand of (pi) coordination. The method according to one item.   The method as described in any one of Claims 1-3 whose film thickness of the film of the at least 1 metal chosen from the group which consists of cobalt, ruthenium, and tungsten formed is 1-1000 nm.   The method according to claim 1, wherein the formed film of at least one metal selected from the group consisting of cobalt, ruthenium and tungsten is a seed layer for plating. The method according to any one of claims 1 to 3, wherein the film of at least one metal selected from the group consisting of cobalt, ruthenium and tungsten is an alloy of two or more kinds of the metals.