WO2012050058A1

WO2012050058A1 - Method for formation of aluminum film

Info

Publication number: WO2012050058A1
Application number: PCT/JP2011/073209
Authority: WO
Inventors: 雅浩山本; 秀樹西村; 英行青木; 酒井　達也
Original assignee: Jsr株式会社
Priority date: 2010-10-15
Filing date: 2011-10-07
Publication date: 2012-04-19
Also published as: JPWO2012050058A1; TW201224200A

Abstract

Provided is a method by which a homogeneous and dense aluminum film can be formed on a substrate more simply and more easily in comparison to a conventional method. A method for the formation of an aluminum film, which includes: an application step of applying a material which is for the formation of an aluminum film and which contains a complex composed of both an amine compound and aluminum hydride to the surface of a metal layer to form a coating, said metal layer consisting of at least one metal selected from among copper, cobalt, molybdenum, tungsten, aluminum, nickel and gold; and a curing step of subjecting the coating to heat treatment and/or photo-irradiation to form an aluminum film.

Description

Aluminum film forming method

The present invention relates to an aluminum film forming method.

The metal aluminum material is widely used for the application of the electrode wiring of the semiconductor device represented by DRAM, the application of the reflection film of the optical device, etc. because of its high conductivity and high optical characteristics. In general, sputtering methods, vapor deposition methods, and chemical vapor deposition methods have been the mainstream methods for forming aluminum films (Patent Document 1). However, these methods require an expensive apparatus such as a vacuum chamber and a high-voltage current apparatus, are expensive, and have a problem to be solved for industrialization that they are difficult to apply to a large-diameter substrate. . Furthermore, with the recent miniaturization of semiconductor devices and the complication of the shape of optical devices, these conventional methods also have the problem of generating defects in the film and reducing step coverage.
On the other hand, the film formation method by coating does not require an expensive apparatus, the film formation cost is relatively low, and good film formation on a narrow trench substrate is also expected using the penetration force of the liquid material. it can. So far, an aluminum film forming method using a coating type composition using an aluminum hydride compound has been reported (Patent Document 2). This document describes as an advantage of this film forming method that an aluminum film having a uniform thickness can be formed inside a trench having a small opening width and a large aspect ratio.

JP 2000-86673 A JP 2006-237392 A

However, the conventional aluminum film forming method is to form an aluminum film on the surface of the base film after forming the base film by a process with many steps using a liquid composition containing a titanium compound or the like. There is a problem that the number of processes is large.
In the case where the base film is not formed, there is a problem that a homogeneous aluminum film may not be obtained.
In view of the above problems, an object of the present invention is to provide a method for forming a homogeneous and dense aluminum film on a substrate more easily than a conventional method.

The present inventors apply an aluminum film-forming composition containing a complex of an amine compound and aluminum hydride and an organic solvent on the surface of a metal layer made of a specific metal such as copper, and form a coating film. After forming, if an aluminum film is formed by performing a treatment such as heat treatment on the coating film, a metal made of copper or the like that is easy to form without requiring many steps for forming a base film as in the prior art It has been found that by simply forming a layer (undercoat film), a uniform and dense aluminum film can be easily formed on the substrate while ensuring high adhesion (adhesion), and the present invention has been completed. .

That is, the present invention provides the following [1] to [6].
[1] A material for forming an aluminum film containing a complex of an amine compound and aluminum hydride is formed on the surface of a metal layer made of at least one metal selected from copper, cobalt, molybdenum, tungsten, aluminum, nickel, and gold. A coating step of coating and forming a coating film; and an aluminum film forming step of forming an aluminum film by performing at least one treatment selected from heat treatment and light irradiation treatment on the coating film. An aluminum film forming method.
[2] The aluminum film formation method according to [1], wherein the aluminum film formation material further contains a second amine compound.
[3] The aluminum film forming method according to [2], wherein the concentration of the second amine compound is 3 to 70% by mass with respect to the total of the complex and the second amine compound.
[4] The aluminum film forming method according to any one of [1] to [3], wherein the aluminum film forming material further contains a titanium compound.
[5] The method for forming an aluminum film according to [4], wherein the concentration of the titanium compound is 0.00001 to 1 mol% with respect to the total of the complex and the titanium compound.
[6] The aluminum film forming method according to any one of [1] to [5], further including a metal layer forming step of forming the metal layer on a substrate before the coating step.

According to the method for forming an aluminum film of the present invention, a uniform and dense aluminum film can be obtained on the substrate simply and with a smaller number of steps than the conventional method while ensuring high adhesion (adhesion). .
The aluminum film formed by the method of the present invention can be used for a structural part including an electrode wiring of a semiconductor device, a reflection film of an optical device, or the like.

In the aluminum film forming method of the present invention, (a) an aluminum film forming material containing a complex of an amine compound and aluminum hydride is at least one selected from copper, cobalt, molybdenum, tungsten, aluminum, nickel, and gold. A coating step of coating the surface of the metal layer made of the metal to form a coating film, and (b) performing at least one treatment selected from a heat treatment and a light irradiation treatment on the coating film, to form an aluminum film And an aluminum film forming step for forming the film.

First, the step (a) will be described. In the step (a), a metal layer formed of at least one metal selected from copper, cobalt, molybdenum, tungsten, aluminum, nickel, and gold is used as the aluminum film forming material containing a complex of an amine compound and aluminum hydride. It is the process of apply | coating to the surface of and forming a coating film.
The metal layer is a metal layer made of at least one metal selected from copper, cobalt, molybdenum, tungsten, aluminum, nickel, and gold, and may be a metal layer made of a kind of metal (pure metal), copper, It may be a metal layer made of an alloy containing two or more selected from cobalt, molybdenum, tungsten, aluminum, nickel and gold.
The metal layer itself may be a substrate, or may be formed on a substrate different from the metal layer.
The shape of the surface of the metal layer may be a flat surface or a non-planar surface having a step, and is not particularly limited.

When the metal layer is formed on the substrate, there is no particular limitation on the material, shape, etc. of the material (base material) constituting the substrate, but the material is preferably one that can withstand the heat treatment of the next step. Specific examples of the material of the base material in this case include glass, plastic, ceramics, a silicon substrate, and the like. Examples of the glass include quartz glass, borosilicate glass, soda glass, and lead glass. Examples of the plastic include polyimide and polyethersulfone. Moreover, examples of the shape of the substrate in this case include a bulk shape, a plate shape, and a film shape, and are not particularly limited.

When the metal layer is formed on a substrate different from the metal layer, the metal layer is formed on the substrate by chemical vapor deposition (CVD), physical vapor deposition ( Known methods such as the PVD method). Examples of the chemical vapor deposition method (CVD method) include a thermal CVD method, a photo CVD method, a plasma CVD method, and a metal organic chemical vapor deposition method. Examples of physical vapor deposition include vacuum deposition, molecular beam epitaxy, sputtering, ion plating, and laser deposition.

When applying the aluminum film forming composition to be described later on the surface of the metal layer, for example, spin coating, roll coating, curtain coating, dip coating, spraying, droplet discharge, etc. This method can be used. In the coating process, coating conditions are adopted such that the composition for forming an aluminum film extends to every corner of the surface of the metal layer depending on the shape and size of the metal layer to be coated. For example, when the spin coating method is adopted as the coating method, the rotation speed of the spinner can be preferably 300 to 2,500 rpm, more preferably 500 to 2,000 rpm.

The composition for forming an aluminum film used in the present invention contains a complex of the above (A) amine compound and an aluminum hydride compound as an essential component, and in addition, (B) an organic solvent, (C ) A second amine compound other than the amine compound contained in the complex, and (D) a titanium compound may also be contained.
(Called often conventionally "Alan".) (A) above aluminum hydride contained in the complex of an amine compound and aluminum hydride is a compound consisting of aluminum and hydrogen atoms, it is generally in the AlH ₃ expressed.

The complex of (A) an amine compound and aluminum hydride contained in the composition for forming an aluminum film used in the present invention is, for example, “JK Ruff et al., J. Amer. Chem. Soc., 82”. Vol., 2141, 1960 "," GW Fraser et al., J. Chem. Soc., 3742, 1963 ", and" JL Atwood et al., J. Amer. Chem. Soc., 113 ". Volume, page 8133, 1991 "etc. and can be synthesized.
The complex of (A) an amine compound and aluminum hydride contained in the aluminum film forming composition used in the present invention is, for example, a hydrochloride of an amine compound in a diethyl ether suspension of lithium aluminum hydride. Can be synthesized by, for example, reacting in N ₂ gas with stirring at room temperature. The reaction temperature, reaction solvent, and the like should be appropriately selected depending on the type of the complex of the desired amine compound and aluminum hydride.

The amine compound used in the present invention can be a monoamine compound or a polyamine compound. As said polyamine compound, a diamine compound, a triamine compound, a tetraamine compound etc. can be mentioned, for example.

Examples of the monoamine compound include the following formula (1):
R ¹ R ² R ³ N (1)
(Here, R ¹ , R ² and R ³ are each independently a hydrogen atom, alkyl group, alkenyl group, alkynyl group, aryl group or aralkyl group.)
And other monoamine compounds. The alkyl group, alkenyl group or alkynyl group as R ¹ , R ² and R ³ in the formula (1) may be linear, cyclic or branched.

Examples of the alkyl group include alkyl groups having 1 to 12 carbon atoms. Specific examples thereof include, for example, methyl group, ethyl group, propyl group, cyclopropyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, cyclohexyl group, Examples thereof include 2-methylbutyl group and 2-ethylhexyl group.
As said alkenyl group, the alkenyl group which has an unsaturated group can be mentioned, for example. Specific examples thereof include vinyl group, allyl group, crotyl group, ethynyl group and the like.
Examples of the alkynyl group include a phenylethynyl group.
Examples of the aryl group include a phenyl group.
Examples of the aralkyl group include a benzyl group.

Specific examples of the compound represented by the formula (1) include, for example, ammonia, trimethylamine, triethylamine, dimethylethylamine, methyldiethylamine, tri-n-propylamine, tri-isopropylamine, tricyclopropylamine, tri-n-butylamine, Triisobutylamine, tri-t-butylamine, tri-2-methylbutylamine, tri-n-hexylamine, tricyclohexylamine, tri (2-ethylhexyl) amine, trioctylamine, triphenylamine, tribenzylamine, dimethylphenyl Amine, diethylphenylamine, diisobutylphenylamine, methyldiphenylamine, ethyldiphenylamine, isobutyldiphenylamine, dimethylamine, diethylamine, di-n-propyl Min, diisopropylamine, dicyclopropylamine, di-n-butylamine, diisobutylamine, di-t-butylamine, methylethylamine, methylbutylamine, di-n-hexylamine, dicyclohexylamine, di (2-ethylhexyl) amine, dioctyl Amine, diphenylamine, dibenzylamine, methylphenylamine, ethylphenylamine, isobutylphenylamine, methylallylamine, methylvinylamine, methyl (phenylethynyl) amine, phenyl (phenylethynyl) amine, methylamine, ethylamine, n-propylamine , Isopropylamine, cyclopropylamine, n-butylamine, isobutylamine, t-butylamine, 2-methylbutylamine, n-hexylamine, cyclo Hexylamine, 2-ethylhexylamine, octylamine, phenylamine, and benzyl amine.

Examples of the diamine compound include ethylenediamine, N, N′-dimethylethylenediamine, N, N′-diethylethylenediamine, N, N′-diisopropylethylenediamine, N, N′-di-t-butylethylenediamine, and N, N′-. Examples thereof include diphenylethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetraethylethylenediamine, and phenylenediamine.
Examples of the triamine compound include diethylenetriamine, 1,7-dimethyl-1,4,7-triazaheptane, 1,7-diethyl-1,4,7-triazaheptane, N, N ′, N ″ — And trimethyl-1,3,5-triazacyclohexane.
Examples of the tetraamine compound include trimethylenetetraamine and triethylenetetraamine. These amine compounds can be used alone or in admixture of two or more compounds.

Of these amine compounds, it is preferable to use a monoamine compound represented by the formula (1). Trimethylamine, triethylamine, triisopropylamine, triisobutylamine, tri-t-butylamine, dimethylamine, diethylamine, diisopropylamine, diisobutylamine, di-t-butylamine, methylethylamine, methylbutylamine, methylphenylamine, ethylphenylamine, isobutyl More preferably, phenylamine, methylamine, ethylamine, isopropylamine, cyclopropylamine, n-butylamine, isobutylamine, t-butylamine, 2-methylbutylamine, n-hexylamine or phenylamine are used. Among them, it is more preferable to use trimethylamine, triethylamine, tri-isopropylamine, triisobutylamine or tri-t-butylamine.
These amine compounds can be used alone or in admixture of two or more.

The organic solvent (B) contained in the composition for forming an aluminum film used in the present invention dissolves the above-described complex of an amine compound and an aluminum hydride compound, and components to be optionally added as described later, And if it does not react with these, it will not specifically limit. For example, a hydrocarbon solvent, an ether solvent, other polar solvents, etc. can be used.

Examples of the hydrocarbon solvent include n-pentane, cyclopentane, n-hexane, cyclohexane, n-heptane, cycloheptane, n-octane, cyclooctane, decane, cyclodecane, dicyclopentadiene hydride, benzene, toluene, Xylene, durene, indene, tetrahydronaphthalene, decahydronaphthalene, squalane and the like can be mentioned.

Examples of the ether solvent 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, and bis. (2-methoxyethyl) ether, p-dioxane, anisole, 2-methylanisole, 3-methylanisole, 4-methylanisole, fentol, 2-methylfentol, 3-methylfentol, 4-methylfentol, Examples include veratrol, 2-ethoxyanisole, and 1,4-dimethoxybenzene.
Examples of the other polar solvent include methylene chloride and chloroform.
These organic solvents can be used alone or in admixture of two or more.

Among these, it is preferable to use a hydrocarbon solvent or a mixed solvent of a hydrocarbon solvent and an ether solvent in view of solubility and stability of the solution to be formed.
As the hydrocarbon solvent, for example, n-pentane, cyclopentane, n-hexane, cyclohexane, n-heptane, cycloheptane, n-octane, benzene, toluene or xylene is preferable.
Examples of the ether solvent include diethyl ether, dipropyl ether, dibutyl ether, ethylene glycol diethyl ether, ethylene glycol methyl ethyl ether, tetrahydrofuran, tetrahydropyran, anisole, 2-methylanisole, 3-methylanisole, 4-methylanisole, phen Tolu, veratrol, 2-ethoxyanisole and 1,4-dimethoxybenzene are preferred.

(C) Examples of the second amine compound other than the amine compound contained in the complex include a monoamine compound and a polyamine compound.
As said polyamine compound, a diamine compound, a triamine compound, a tetraamine compound etc. can be mentioned, for example.

Examples of the monoamine compound include the following formula (2):
R ⁴ R ⁵ R ⁶ N (2)
(Here, R ⁴ , R ⁵ and R ⁶ are each independently a hydrogen atom, alkyl group, alkenyl group, alkynyl group, aryl group or aralkyl group.)
And other monoamine compounds. The alkyl group, alkenyl group or alkynyl group as R ⁴ , R ⁵ and R ⁶ in the formula (2) may be linear, cyclic or branched.

Examples of the alkyl group include alkyl groups having 1 to 12 carbon atoms. Specific examples thereof include, for example, methyl group, ethyl group, propyl group, cyclopropyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, cyclohexyl group, Examples thereof include 2-methylbutyl group and 2-ethylhexyl group.
Examples of the alkenyl group include an alkenyl group having an unsaturated group. Specific examples thereof include vinyl group, allyl group, crotyl group, ethynyl group and the like.
Examples of the alkynyl group include a phenylethynyl group.
Examples of the aryl group include a phenyl group.
Examples of the aralkyl group include a benzyl group.

Specific examples of the compound represented by the formula (2) include, for example, ammonia, trimethylamine, triethylamine, dimethylethylamine, methyldiethylamine, tri-n-propylamine, tri-isopropylamine, tricyclopropylamine, tri-n-butylamine, Triisobutylamine, tri-t-butylamine, tri-2-methylbutylamine, tri-n-hexylamine, tricyclohexylamine, tri (2-ethylhexyl) amine, trioctylamine, triphenylamine, tribenzylamine, dimethylphenyl Amine, diethylphenylamine, diisobutylphenylamine, methyldiphenylamine, ethyldiphenylamine, isobutyldiphenylamine, dimethylamine, diethylamine, di-n-propyl Min, diisopropylamine, dicyclopropylamine, di-n-butylamine, diisobutylamine, di-t-butylamine, methylethylamine, methylbutylamine, di-n-hexylamine, dicyclohexylamine, di (2-ethylhexyl) amine, dioctyl Amine, diphenylamine, dibenzylamine, methylphenylamine, ethylphenylamine, isobutylphenylamine, methylallylamine, methylvinylamine, methyl (phenylethynyl) amine, phenyl (phenylethynyl) amine, methylamine, ethylamine, n-propylamine , Isopropylamine, cyclopropylamine, n-butylamine, isobutylamine, t-butylamine, 2-methylbutylamine, n-hexylamine, cyclo Hexylamine, 2-ethylhexylamine, octylamine, phenylamine, and benzyl amine.

Of these amine compounds, trimethylamine, triethylamine, methyldiethylamine, dimethylethylamine, dimethylamine, diethylamine, diisopropylamine, di-t-butylamine, methylethylamine, methylamine, ethylamine, ethylenediamine, and diethylenetriamine are more preferable. Of these, trimethylamine, triethylamine, methyldiethylamine, dimethylethylamine, dimethylamine, diethylamine, and ethylenediamine are more preferable.
These amine compounds can be used alone or in admixture of two or more compounds. By adding these amine compounds, the storage stability of the aluminum film-forming composition and the material stability at high temperatures are improved.

Examples of the (D) titanium compound include compounds represented by the following formulas (3) to (7).
Ti (OR ⁷ ) ₄ (3)
Here, R ⁷ is an alkyl group having 1 to 10 carbon atoms, a phenyl group, a halogenated alkyl group or a halogenated phenyl group.
Ti (OR ⁸ ) _x L _4-x (4)
Here, the definition of R ⁸ is the same as R ⁷ in the above formula (3), and L is the formula

It is group represented by these. Here, R ⁹ and R ¹⁰ are the same or different and are an alkyl group having 1 to 10 carbon atoms, a phenyl group, an alkoxy group, a halogenated alkyl group, or a halogenated phenyl group, and x is an integer of 0 to 3. .

Ti (OR ¹¹ ) _y (X) _4-y (5)
Here, R ¹¹ is an alkyl group or a phenyl group, X is a halogen atom, and y is an integer of 0 to 3.
Ti (NR ¹² ) ₄ (6)
Here, R ¹² is an alkyl group or a phenyl group.
Ti (Cp) _n (Y) _4-n (7)
Here, Cp is a group having a cyclopentadienyl skeleton, Y is a halogen atom or an alkyl group, and n is an integer of 1 to 4.

In the above formulas (3) and (4), R ⁷ and R ⁸ are preferably methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl, methoxy, ethoxy Group, n-propoxy group, i-propoxy group, n-butoxy group, t-butoxy group, hexyl group, cyclohexyl group, phenoxy group, methylphenoxy group, trifluoromethyl group, more preferably methyl group, ethyl group N-propyl group, i-propyl group, n-butyl group, t-butyl group, hexyl group, cyclohexyl group and phenyl group. In the above formula (4), R ⁹ and R ¹⁰ in L are preferably methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl, methoxy, ethoxy Group, n-propoxy group, i-propoxy group, n-butoxy group, t-butoxy group, phenoxy group, methylphenoxy group, trifluoromethyl group, particularly preferably methyl group, ethyl group, i-propyl group, a t-butyl group, a methoxy group, an ethoxy group, an i-propoxy group, a t-butoxy group, and a trifluoromethyl group.

Specific examples of the titanium compound represented by the above formula (3) include, for example, titanium methoxide, titanium ethoxide, titanium-n-propoxide, titanium-n-nonyl oxide, titanium stearyl oxide, titanium isopropoxide, and titanium. -N-butoxide, titanium isobutoxide, titanium-t-butoxide, titanium trimethylsiloxide, titanium-2-ethylhexoxide, titanium methoxypropoxide, titanium phenoxide, titanium methylphenoxide, titanium fluoromethoxide, titanium chlorophenoxide, etc. Can be mentioned.

Specific examples of the titanium compound represented by the above formula (4) include, for example, tetrakis (penta-2,4-diketo) titanium, tetrakis (2,2,6,6-tetramethylhepta-3,5-diketo). Titanium, tetrakis (1-ethoxybutane-1,3-diketo) titanium, tetrakis (1,1,1,5,5,5-hexafluoropenta-2,4-diketo) titanium, (2,2-dimethylhexa) -3,5-diketo) titanium, bis (penta-2,4-diketo) titanium dimethoxide, bis (2,2,6,6-tetramethylhepta-3,5-diketo) titanium dimethoxide, bis (1 -Ethoxybutane-1,3-diketo) titanium dimethoxide, bis (1,1,1,5,5,5-hexafluoropenta-2,4-diketo) titanium di Toxide, (2,2-dimethylhexa-3,5-diketo) titanium dimethoxide, bis (penta-2,4-diketo) titanium di-propoxide, bis (2,2,6,6-tetramethylhepta -3,5-diketo) titanium di i-propoxide, bis (1-ethoxybutane-1,3-diketo) titanium di i-propoxide, bis (1,1,1,5,5,5-hexafluoro Examples include penta-2,4-diketo) titanium dii-propoxide, (2,2-dimethylhexa-3,5-diketo) titanium dii-propoxide, and the like.

Specific examples of the titanium compound represented by the above formula (5) include, for example, trimethoxytitanium chloride, triethoxytitanium chloride, tri-n-propoxytitanium chloride, tri-i-propoxytitanium chloride, tri-n-butoxytitanium. Chloride, tri-t-butoxytitanium chloride, triisostearoyl titanium chloride, dimethoxytitanium dichloride, diethoxytitanium dichloride, di-n-propoxytitanium dichloride, di-i-propoxytitanium dichloride, di-n-butoxytitanium dichloride, di -T-butoxy titanium dichloride, diisostearoyl titanium dichloride, methoxy titanium trichloride, ethoxy titanium trichloride Ride, n- propoxytitanium trichloride, i- propoxytitanium trichloride, n- butoxytitanium trichloride, t-butoxy titanium trichloride, isostearoyl trichloride, can be mentioned titanium tetrachloride and the like.

Specific examples of the titanium compound represented by the above formula (6) include, for example, tetrakis (dimethylamino) titanium, tetrakis (diethylamino) titanium, tetrakis (di-t-butoxyamino) titanium, tetrakis (di-i-propoxyamino). ) Titanium, tetrakis (diphenylamino) titanium.

Specific examples of the titanium compound represented by the above formula (7) include, for example, dicyclopentadienyl titanium dichloride, dicyclopentadienyl titanium dibromide, cyclopentadienyl titanium trichloride, cyclopentadienyl titanium tribromide. Dicyclopentadienyldimethyltitanium, dicyclopentadienyldiethyltitanium, dicyclopentadienyldi-t-butyltitanium, dicyclopentadienylphenyltitanium chloride, dicyclopentadienylmethyltitanium chloride, bis (penta Methylcyclopentadienyl) titanium dichloride, bis (pentamethylcyclopentadienyl) titanium dibromide, pentamethylcyclopentadienyltitanium trichloride, Tamethylcyclopentadienyltitanium tribromide, bis (pentamethylcyclopentadienyl) dimethyltitanium, bis (pentamethylcyclopentadienyl) diethyltitanium, bis (pentamethylcyclopentadienyl) di-t-butyltitanium, Examples thereof include bis (pentamethylcyclopentadienyl) phenyl titanium chloride and bis (pentamethylcyclopentadienyl) methyl titanium chloride.

The concentration of the (C) amine compound contained in the composition for forming an aluminum film used in the present invention is based on the total of (A) a complex of an amine compound and an aluminum hydride compound and (C) the amine compound. 70% by mass or less, more preferably 50% by mass or less, and further preferably 3 to 50% by mass.

When the composition for forming an aluminum film used in the present invention contains (D) a titanium compound, the concentration of (D) the titanium compound is (A) a complex of an amine compound and an aluminum hydride compound, and (D ) It is preferably 1 mol% or less, more preferably 0.00001 to 1 mol%, still more preferably 0.00005 to 0.01 mol%, based on the total of the titanium compounds. By setting the concentration of the titanium compound within this range, both good embedding property and stability of the composition can be achieved.

The ratio of the mass excluding (B) solvent and (C) amine compound in the composition for forming an aluminum film in the total mass of the composition (hereinafter referred to as “nonvolatile component content”) is film formation. It is desirable to vary according to the film thickness of the aluminum film to be. For example, when the film thickness of the aluminum film is less than 200 nm, the non-volatile component content of the composition for forming an aluminum film is preferably less than 50% by mass, more preferably 30% by mass or less. When the film thickness of the aluminum film is 200 nm or more, the non-volatile component content of the composition for forming an aluminum film is preferably 50% by mass or more, more preferably 70% by mass or more.

The method for producing the aluminum film forming composition used in the present invention is not particularly limited. For example, a solution obtained by synthesizing a complex of an amine compound and an aluminum hydride compound as described above in the presence of a solvent and then removing insolubles such as by-products with a filter or the like can be used as it is as a composition for forming an aluminum film. it can. Alternatively, after adding a desired solvent to this solution, the solvent used for the reaction, for example, diethyl ether, may be removed under reduced pressure to obtain an aluminum film forming composition.

When the composition for forming an aluminum film used in the present invention contains a titanium compound, in the production thereof, for example, a solution containing a complex of an amine compound and an aluminum hydride compound produced as described above. In addition, a predetermined amount of a solution of a titanium-containing compound can be added while stirring. The temperature at the time of addition is preferably 0 to 150 ° C., more preferably 5 to 100 ° C. The stirring time is preferably 0.1 to 120 minutes, more preferably 0.2 to 60 minutes. By mixing under such conditions, a stable composition can be obtained.

After the step (a), heat treatment may be performed in order to remove low-boiling components such as a solvent contained in the applied composition for forming an aluminum film (coating film). The heating temperature and time vary depending on the type of solvent used and the boiling point (vapor pressure), but can be, for example, 100 to 350 ° C. and 1 to 90 minutes. At this time, the solvent can be removed at a lower temperature by reducing the pressure of the entire system. Preferably, it is 2 to 60 minutes at 100 to 250 ° C.

Next, step (b) will be described. In the step (b), the coating film (usually a liquid material) obtained in the step (a) is subjected to at least one treatment selected from a heat treatment and a light irradiation treatment to form an aluminum film (usually a cured product). It is a process of forming.

The temperature of the heat treatment is preferably 60 ° C. or higher, more preferably 70 ° C. to 600 ° C., and further preferably 200 ° C. to 500 ° C. The heating time is preferably 30 seconds to 120 minutes, more preferably 1 to 90 minutes, still more preferably 2 to 60 minutes.
Examples of the light source used for the light irradiation treatment include a mercury lamp, deuterium lamp, rare gas discharge light, YAG laser, argon laser, carbon dioxide gas laser, and rare gas halogen excimer laser. Examples of the mercury lamp include a low-pressure mercury lamp and a high-pressure mercury lamp. Examples of the rare gas used for the discharge light of the rare gas include argon, krypton, and xenon. Examples of the rare gas halogen used in the rare gas halogen excimer laser include XeF, XeCl, XeBr, KrF, KrCl, ArF, ArCl, and the like.

The output of these light sources is preferably 10 to 5,000 W, more preferably 100 to 1,000 W. The wavelength of these light sources is not particularly limited, but is preferably 170 nm to 600 nm. In addition, the use of laser light is particularly preferable from the viewpoint of the film quality of the formed aluminum film. In addition, plasma oxidation can be performed in an oxidizing gas atmosphere for the purpose of forming a better aluminum film. The oxidizing conditions for the plasma oxidation at this time are, for example, RF power of 20 to 100 W, oxygen gas of 90 to 100% and the remainder (10% or less) of argon gas as the introduced gas, and the introduction pressure of the introduced gas is 0. 0.05 to 0.2 Pa, and the plasma oxidation time can be 10 to 240 seconds.

The atmosphere for carrying out the application of the composition for forming an aluminum film, the optional removal of the solvent, and the heat treatment and / or the light irradiation treatment is an oxidizing condition from the viewpoint of promoting the formation of the aluminum film. It is preferable. Examples of the oxidizing gas that realizes the oxidizing conditions include water vapor, oxygen, ozone, carbon monoxide, peroxides having 1 to 3 carbon atoms, alcohol, and aldehyde. Of these, water vapor, oxygen, and ozone are preferable. It is also preferable to mix the oxidizing gas and the inert gas from the viewpoint of controlling the oxidizing conditions. Examples of the inert gas include nitrogen, helium, and argon. The ratio of the oxidizing gas to the total of the inert gas and the oxidizing gas is preferably 1 to 70 mol%, more preferably 3 to 40 mol%.

Only one or both of the heat treatment and the light irradiation treatment may be performed. When both heat treatment and light irradiation treatment are performed, the heat treatment and the light treatment may be performed at the same time regardless of the order. Of these, it is preferable to perform only heat treatment or perform both heat treatment and light treatment. Further, for the purpose of forming a better aluminum film, plasma oxidation may be performed separately from the heat treatment and / or light irradiation treatment step.
Further, as a method of forming an aluminum film, an uncured aluminum film is formed in an inert gas atmosphere containing no oxidizing gas by the above coating method, and then anodized to form a cured aluminum film. It can also be formed.

Hereinafter, the present invention will be specifically described with reference to examples. The following operations were all performed in a dry nitrogen atmosphere except where otherwise noted. All the solvents used were dehydrated in advance with Molecular Sieves 4A (Union Showa Co., Ltd.) and degassed by bubbling nitrogen gas. The specific resistance was measured with a probe resistivity meter (model: RT-80 / RG-80) manufactured by Napson. The film thickness and film density were measured with an oblique incidence X-ray analyzer (type: X'Pert MRD) manufactured by Philips. The ESCA spectrum was measured with a device manufactured by JEOL Ltd. (type: JPS80). The reflectance was measured with a spectrophotometer (model: U-4100) manufactured by Hitachi High-Technologies Corporation.

(Synthesis Example 1) Preparation of composition for forming aluminum film 1-1. Synthesis of complex of amine compound and aluminum hydride 3.80 g of lithium aluminum hydride was charged into a 200 mL three-necked flask containing a magnetic stirrer. The three connection ports of the three-neck flask were each connected with a 100 mL powder addition funnel, a suction stopper three-way cock connected to a nitrogen stream, and a glass stopper. After charging triethylamine hydrochloride hydrochloride (17.80 g) into a powder addition funnel, the three-necked flask was placed under a nitrogen seal through a suction stopper three-way cock.
100 mL of hexane was added to the three-necked flask using a glass syringe. While stirring with a magnetic stirrer at a rotational speed of 1,000 rpm, triethylamine hydrochloride was gradually dropped into the three-necked flask over 10 minutes, and stirring was further continued for 2 hours.
Then, using a polytetrafluoroethylene tube filled with absorbent cotton (Japanese Pharmacopoeia absorbent cotton), the reaction mixture was taken out into a separate container by feeding, and then a polytetrafluoroethylene membrane having a pore diameter of 0.1 μm. It filtered with the filter (made by Whatman Inc.). The filtrate was received in a 300 mL eggplant-shaped flask, and after completion of filtration, a magnetic stirrer was placed and a three-way suction cock was attached.
The suction stopper three-way cock was connected to a vacuum pump via a trap, and the solvent was removed under reduced pressure while stirring with a magnetic stirrer at a rotational speed of 300 rpm. After removing the solvent, the residue was filtered using a membrane filter (manufactured by Whatman Inc.) made of polytetrafluoroethylene having a pore size of 0.1 μm, whereby 10.25 g of a complex of triethylamine and aluminum hydride was colorless and transparent. Obtained as a liquid (yield 55%).

1-2. Preparation of mixture of amine compound and aluminum hydride, amine compound and solvent After adding 1.01 g of triethylamine to 4.00 g of the complex of triethylamine and aluminum hydride obtained in 1-1 above. 4-methylanisole was added to a total amount of 8.00 g to prepare a solution containing 50% by mass of a complex of triethylamine and aluminum hydride.

1-3. Preparation of a solution containing a titanium compound 0.11 g of cyclopentadienyl titanium trichloride was charged into a 30 mL glass container, and 4-methylanisole was added thereto to make a total amount of 25.00 g. After sufficiently stirring, the mixture is allowed to stand at room temperature for 4 hours, and then filtered using a membrane filter (manufactured by Whatman Inc.) made of polytetrafluoroethylene having a pore size of 0.1 μm, thereby obtaining cyclopentadienyl titanium trichloride. A solution containing 20 μmol / g of chloride was obtained.

1-4. Preparation of composition for forming aluminum film 1-2. To 0.50 mL of a solution containing 50% by mass of the complex of triethylamine and aluminum hydride prepared in the above 1-3. A composition for forming an aluminum film was prepared by adding 27 μL of a solution containing 20 μmol / g of cyclopentadienyltitanium trichloride prepared in step 1 at room temperature and then continuing stirring for 1 minute.

Example 1
A metal copper layer was formed on the silicon substrate by sputtering. The thickness of the metallic copper layer was 100 nm.
Next, the silicon substrate on which the metallic copper layer is formed is mounted again on the spin coater, and 4 mL of the aluminum film forming composition prepared in the above (Synthesis Example 1) is dropped on the surface of the metallic copper layer, and the rotational speed is 600 rpm for 10 seconds. Spinned. This substrate was heated on a hot plate at 150 ° C. for 10 minutes. Thereafter, when the substrate was further heated at 350 ° C. for 30 minutes, the surface of the substrate was covered with a film having a metallic luster.
When the ESCA spectrum of this film was observed, a peak attributed to Al _2p was observed at 73.5 eV, and it was found that this film was an aluminum film. The film thickness was 200 nm, the specific resistance value was 3.6 μΩ · cm, and the reflectance at a wavelength of 700 nm was 78%.
Further, when the adhesion was evaluated by a cross-cut tape method according to JIS K-5600-5-6, no peeling between the metal copper layer and the aluminum film was observed.

(Example 2)
A metal aluminum layer was formed on the silicon substrate by sputtering. The thickness of the metal aluminum layer was 200 nm.
Next, the silicon substrate on which the metal aluminum layer was formed was mounted again on the spin coater, and 4 mL of the aluminum film forming composition prepared in the above (Synthesis Example 1) was dropped on the surface of the metal aluminum layer, and the rotation speed was 600 rpm for 10 seconds. Spinned. This substrate was heated on a hot plate at 150 ° C. for 10 minutes. Thereafter, when the substrate was further heated at 350 ° C. for 30 minutes, the surface of the substrate was covered with a film having a metallic luster.
When the ESCA spectrum of this film was observed, a peak attributed to Al _2p was observed at 73.5 eV, and it was found that this film was an aluminum film. The film thickness was 200 nm, the specific resistance value was 4.0 μΩ · cm, and the reflectance at a wavelength of 700 nm was 64%.
The adhesion was evaluated by a cross-cut tape method in accordance with JIS K-5600-5-6, and no peeling between the metal aluminum layer and the aluminum film was observed.

(Example 3)
A metallic cobalt layer was formed on the silicon substrate by sputtering. The thickness of the metallic cobalt layer was 100 nm.
Next, the silicon substrate on which the metallic cobalt layer was formed was mounted again on the spin coater, and 4 mL of the aluminum film forming composition prepared in the above (Synthesis Example 1) was dropped on the surface of the metallic cobalt layer, and the rotation was performed at 600 rpm for 10 seconds. Spinned. This substrate was heated on a hot plate at 150 ° C. for 10 minutes. Thereafter, when the substrate was further heated at 350 ° C. for 30 minutes, the surface of the substrate was covered with a film having a metallic luster.
When the ESCA spectrum of this film was observed, a peak attributed to Al _2p was observed at 73.5 eV, and it was found that this film was an aluminum film. The film thickness was 100 nm, the specific resistance value was 6.2 μΩ · cm, and the reflectance at a wavelength of 700 nm was 52%.
The adhesion was evaluated by a cross-cut tape method in accordance with JIS K-5600-5-6. As a result, no peeling between the metal cobalt layer and the aluminum film was observed.

Example 4
A metal molybdenum layer was formed on the silicon substrate by sputtering. The thickness of the metal molybdenum layer was 80 nm.
Next, the silicon substrate on which the metal molybdenum layer was formed was mounted again on the spin coater, and 4 mL of the aluminum film forming composition prepared in the above (Synthesis Example 1) was dropped on the surface of the metal molybdenum layer, and the rotation was performed at 600 rpm for 10 seconds. Spinned. This substrate was heated on a hot plate at 150 ° C. for 10 minutes. Thereafter, when the substrate was further heated at 350 ° C. for 30 minutes, the surface of the substrate was covered with a film having a metallic luster.
When the ESCA spectrum of this film was observed, a peak attributed to Al _2p was observed at 73.5 eV, and it was found that this film was an aluminum film. The film thickness was 100 nm, the specific resistance was 6.8 μΩ · cm, and the reflectance at a wavelength of 700 nm was 46%.
Further, when the adhesion was evaluated by a cross-cut tape method according to JIS K-5600-5-6, no peeling between the metal molybdenum layer and the aluminum film was observed.

(Example 5)
A metal tungsten layer was formed on the silicon substrate by sputtering. The thickness of the metal tungsten layer was 100 nm.
Next, the silicon substrate on which the metal tungsten layer was formed was mounted again on the spin coater, and 4 mL of the aluminum film forming composition prepared in the above (Synthesis Example 1) was dropped onto the surface of the metal tungsten layer, and the rotation was performed at 600 rpm for 10 seconds. Spinned. This substrate was heated on a hot plate at 150 ° C. for 10 minutes. Thereafter, when the substrate was further heated at 350 ° C. for 30 minutes, the surface of the substrate was covered with a film having a metallic luster.
When the ESCA spectrum of this film was observed, a peak attributed to Al _2p was observed at 73.5 eV, and it was found that this film was an aluminum film. The film thickness was 100 nm, the specific resistance value was 5.8 μΩ · cm, and the reflectance at a wavelength of 700 nm was 52%.
Further, when the adhesion was evaluated by a cross-cut tape method according to JIS K-5600-5-6, no peeling between the metal tungsten layer and the aluminum film was observed.

Claims

An aluminum film-forming material containing a complex of an amine compound and aluminum hydride is applied to the surface of a metal layer made of at least one metal selected from copper, cobalt, molybdenum, tungsten, aluminum, nickel, and gold. A coating process for forming a coating film;
An aluminum film forming method, comprising: an aluminum film forming step of forming an aluminum film by performing at least one treatment selected from heat treatment and light irradiation treatment on the coating film.
The method for forming an aluminum film according to claim 1, wherein the material for forming an aluminum film further contains a second amine compound.
The method for forming an aluminum film according to claim 2, wherein the concentration of the second amine compound is 3 to 70 mass% with respect to the total of the complex and the second amine compound.
The method for forming an aluminum film according to any one of claims 1 to 3, wherein the material for forming an aluminum film further contains a titanium compound.
The method for forming an aluminum film according to claim 4, wherein the concentration of the titanium compound is 0.00001 to 1 mol% with respect to the total of the complex and the titanium compound.
The aluminum film forming method according to any one of claims 1 to 5, further comprising a metal layer forming step of forming the metal layer on a substrate before the coating step.