JP2003064475A - Raw material of chemical vapor deposition and method for manufacturing thin film using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a raw material for CVD which uses an inexpensive metal halide compound and has the excellent supply stability and the excellent composition controllability of a raw material, and to provide a method for manufacturing thin film using the same. SOLUTION: The raw material for chemical vapor deposition is a raw material for forming the thin film of a metallic nitride and/or metallic carbide on a base material by chemical vapor deposition process and contains the metal halide compound expressed by MXm and a compound containing cyano group expressed by R(CN)n (in the formula, M represents titanium, zirconium, hafnium, vanadium, niobium or tantalum, (m) represents 4 when M is titanium, zirconium or hafnium and 5 when M is vanadium, niobium or tantalum. X represents a halogen atom, R represents a 2-18C hydrocarbon group and (n) represents 1 or 2).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a raw material for chemical vapor deposition (hereinafter sometimes referred to as CVD) and a method for producing a thin film by the chemical vapor deposition method. More specifically, it is specified as a metal halide compound. To a chemical vapor deposition (CVD) raw material containing the compound having a cyano group, and a method for producing a metal nitride and / or metal carbide thin film using the same.

[0002]

2. Description of the Related Art Titanium, zirconium, hafnium, vanadium, niobium or tantalum nitrides and / or carbides have excellent strength such as wear resistance, and are therefore suitable for cutting tools. It is used as a ceramic coating material and is also used as a barrier layer for copper wiring materials in the field of semiconductors due to its excellent element diffusion preventing function.

Examples of methods for producing these metal nitride and / or metal carbide thin films include a CVD method, a flame deposition method, a sputtering method, an ion plating method, and a coating pyrolysis method. Among them, the CVD method has many advantages such as excellent productivity and fine processing, and particularly in the case of manufacturing a semiconductor barrier layer, it has excellent composition controllability, step coverage, and step embedding property. That is, it is considered as an optimum manufacturing process because it is compatible with the LSI process.

Regarding the production of a metal nitride and / or metal carbide thin film by the CVD method, for example, regarding the ceramic coating of cutting tools and coated cermets, Japanese Patent No. 2590139, Japanese Patent Publication No. 11-510.
Japanese Patent No. 856 and Japanese Patent No. 2775955 report a method in which a metal chloride compound is used as a metal source compound and acetonitrile is used as a nitrogen source and / or a carbon source. However, these methods have a problem in the supply stability of the raw material when the metal chloride compound is a solid. Further, the obtained thin film is only a mixture of metal nitride and metal carbide.

Regarding the semiconductor barrier layer, Japanese Unexamined Patent Publication No. 2000-204095 reports that a tantalum nitride thin film is produced by using a solution raw material composed of an aminotantalum compound and an organic solvent, and is also characterized. Kaihei 20
In Japanese Patent Laid-Open No. 00-265274, it is reported that a conductive tantalum thin film is produced using a solution raw material composed of a tantalum compound and a hydrocarbon-based and / or amine-based solvent. However, although these methods are excellent in composition controllability of the obtained thin film, they have a problem in productivity because the compound of the tantalum source is expensive and chemically unstable.

Accordingly, it is an object of the present invention to provide a CVD raw material which uses an inexpensive metal halide compound and is excellent in feed stability and composition controllability of the raw material, and a method for producing a thin film using the same. is there.

[0007]

As a result of repeated studies, the present inventors can solve the above problems by using a solution of a metal halide compound and a compound having a specific cyano group as a raw material for CVD. The inventors have found that and reached the present invention.

The present invention has been made based on the above findings, and is a raw material for forming a metal nitride and / or metal carbide thin film on a substrate by chemical vapor deposition, and has the following general formula (I): A chemical vapor deposition raw material containing a metal halide compound represented by and a compound having a cyano group represented by the following general formula (II), and a metal nitride by a chemical vapor deposition method using the same, And / or a method for producing a metal carbide thin film.

[0009]

[Chemical 2]

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below.

The chemical vapor deposition raw material of the present invention comprises a metal halide compound represented by the above general formula (I) and a compound having a cyano group represented by the above general formula (II). It is a solution raw material and may contain other compound components as an optional component.

In the above general formula (I) according to the present invention,
Examples of the halogen atom represented by X include fluorine, chlorine, bromine, iodine and astatine. As the halogen atom, chlorine and bromine are preferable because they are inexpensive, and chlorine is more preferable.

The compound having a cyano group represented by the above general formula (II) according to the present invention is used as a solvent for stably dissolving a metal halide compound at an arbitrary concentration. , A nitrogen source and / or a carbon source may be used as a reactant. As the hydrocarbon group having 2 to 18 carbon atoms represented by R in the compound, for example, when n is 1, ethyl, propyl,
Isopropyl, butyl, secondary butyl, tertiary butyl, isobutyl, amyl, isoamyl, tertiary amyl, hexyl,
Cyclohexyl, heptyl, isoheptyl, tertiary heptyl, n-octyl, isooctyl, tertiary octyl, 2-
Alkyl groups such as ethylhexyl, nonyl, isononyl, decyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, peptadecyl, octadecyl,
Cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, naphthyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 4-vinylphenyl, 3-isopropylphenyl, 4-isopropylphenyl, 4- Butylphenyl, 4-isobutylphenyl, 4-tert-butylphenyl, 4-hexylphenyl, 4-cyclohexylphenyl, 4-octylphenyl, 4- (2-ethylhexyl) phenyl, 2,3-dimethylphenyl, 2,4- Dimethylphenyl, 2,5-dimethylphenyl, 2,6-
Dimethylphenyl, 3,4-dimethylphenyl, 3,5
-Dimethylphenyl, 2,4-ditert-butylphenyl,
2,5-di-tert-butylphenyl, 2,6-di-tert-butylphenyl, 2,4-di-tert-pentylphenyl, 2,5-
Aryl groups such as ditertiary amylphenyl, 2,4-dicumylphenyl, cyclohexylphenyl, biphenyl, 2,4,5-trimethylphenyl, benzyl, phenethyl, 2-phenylpropan-2-yl, diphenylmethyl, styryl, Examples thereof include arylalkyl groups such as cinnamyl. When n is 2, ethylene, propylene, methylethylene, butylene, 1-methylpropylene, 1,
2-dimethylpropylene, 1,3-dimethylpropylene, 1-methylbutylene, 2-methylbutylene, 3-methylbutylene, 4-methylbutylene, 2,4-dimethylbutylene, 1,3-dimethylbutylene, pentylene, hexylene , Heptylene, octylene, decylene, octadecylene, ethane-1,1-diyl, propane-2,2
-Alkylene groups such as diyl, cyclopropane-1,1-
Diyl, cyclopropane-1,2-diyl, cyclobutane-1,1-diyl, cyclobutane-1,2-diyl,
Cyclobutane-1,3-diyl, cyclopentane-1,
1-diyl, cyclopentane-1,2-diyl, cyclopentane-1,3-diyl, cyclohexane-1,1-
Cycloalkanediyl groups such as diyl, cyclohexane-1,2-diyl, cyclohexane-1,3-diyl, cyclohexane-1,4-diyl, 1,2-phenylene,
1,3-phenylene, 1,4-phenylene, 2,5-dimethyl-1,4-phenylene, diphenylmethane-4,
4'-diyl, 2,2-diphenylpropane-4,4 '
-Arylene groups such as diyl and naphthylene.

As the above-mentioned compound having a cyano group,
It is preferable that the metal halide compound used has a high solubility, is easily available, and it is more preferable that there is no large difference in the volatilization temperature from the metal halide compound used. For example, in the case of tantalum pentachloride, compound No. in which R shown below is a hydrocarbon group having 3 to 6 carbon atoms. 1 to
11 is preferred.

[0015]

[Chemical 3]

The chemical vapor deposition raw material of the present invention is not particularly limited by its concentration, and any concentration may be used as long as it can provide a stable solution. It is appropriately selected depending on the film forming speed at that time. If the concentration is less than 0.05 mol / liter, the metal source supply stability may be reduced and the film forming rate may be reduced, and if it exceeds 0.5 mol / liter, the fluidity of the raw material may be deteriorated, and problems such as precipitation may occur. The concentration of the metal halide compound is 0.05 to
The range of 0.5 mol / liter is preferable.

The method for producing a thin film of the present invention means the above-mentioned C.
This is based on a chemical vapor deposition (CVD) method using a VD raw material. The CVD method is a method of introducing a vaporized raw material and a reactive gas used as needed onto a substrate, and then decomposing and / or reacting the raw material on the substrate to grow and deposit a thin film on the substrate. Refers to. In the method for producing a thin film of the present invention, as a raw material supply method, a liquid transportation method of introducing a solution raw material in a solution state to a vaporization chamber and vaporizing the solution in the vaporization chamber is selected, and a deposition method, manufacturing conditions, a manufacturing apparatus, etc. about,
There is no particular limitation, and well-known general conditions and methods can be used.

Examples of the reactive gas used according to the above need include a volatile nitrogen source compound and a volatile carbon source compound. As the nitrogen source compound, nitrogen, ammonia, hydrazine, methylhydrazine, dimethylhydrazine, ethylhydrazine, diethylhydrazine, butylhydrazine, hydrazine derivatives such as phenylhydrazine, ethyl azide, propyl azide, butyl azide,
Azide organic compounds such as phenyl azide, methylamine,
Examples thereof include mono-trialkylamines such as dimethylamine, trimethylamine, monoethylamine, diethylamine and triethylamine, mono-triarylamines such as phenylamine, diphenylamine and triphenylamine, polyamines such as ethylenediamine and acetonitrile. Further, as the carbon source compound, alkanes such as methane, ethane and propane, alkenes such as ethylene, propylene, butylene, isobutylene and allene, alkynes such as acetylene, unsaturated cycloalkanes such as cyclohexene and cyclopentadiene, and the like. Examples thereof include aromatic compounds such as benzene.

These can be arbitrarily selected according to the intended film composition. For example, in the case of producing a thin film of a metal nitride such as tantalum nitride with high purity, those containing no carbon atoms such as nitrogen, ammonia and hydrazine are preferable, and in the case of producing a thin film of metal carbide such as tantalum carbide in a high purity. , Alkanes, alkenes and alkynes are preferred.

As the above-described deposition method, thermal CVD for depositing a thin film by reacting the raw material gas or the raw material gas and the reactive gas only with heat, plasma CVD using heat and plasma, light using heat and light Optical plasma CVD using CVD, heat, light, and plasma. AL that divides the deposition reaction of CVD into elementary processes and performs stepwise deposition at the molecular level.
(Atomic layer) -CVD.

Further, as the above-mentioned manufacturing conditions, a reaction temperature (substrate temperature), a reaction pressure, a deposition rate and the like can be mentioned. The reaction temperature is preferably 160 ° C. or higher at which the metal halide compound according to the present invention sufficiently reacts,
250-800 degreeC is more preferable. Also, the reaction pressure is
In the case of thermal CVD or photo CVD, atmospheric pressure is preferably 10 Pa, and when plasma is used, it is preferably 10 to 2000 Pa. Moreover, the deposition rate can be controlled by the feed rate of the raw material, the reaction temperature, and the reaction pressure. Regarding the deposition rate, if it is large, the characteristics of the obtained thin film may be deteriorated, and if it is small, it may cause a problem in productivity, so 1 to 5000 nm / min is preferable, and 5 to 10 nm is preferable.
00 nm / min is more preferable.

Further, in the method of manufacturing a thin film of the present invention, after the thin film is deposited, an annealing treatment may be performed in order to obtain better electric characteristics and mechanical strength. The temperature in this case is 500 to 1200 ° C. and 600 to 1000.
C is preferred.

[0023]

EXAMPLES The present invention will be described in more detail with reference to Production Examples, Comparative Production Examples, Evaluation Examples, Examples and Comparative Examples. However, the present invention is not limited to the production examples below.

[Production Examples 1 to 5] The compounds having a cyano group shown in Table 1 were dried with calcium hydride, the calcium hydride was removed, phosphorus pentoxide was added, and the previous fraction 10 Cut mass% and residue of 10% by mass,
Distillation purification was performed. Using the solvent obtained, the metal halide compound was dissolved under an argon stream to a concentration of 0.2.
A mol / liter raw material for CVD was prepared.

[0025]

[Table 1]

[Comparative Production Examples 1 to 6] Each of the solvents shown in Table 2 was dried with a desiccant suitable for the solvent, and then 10% by mass of the front distillate and 10% by mass of the residue of the kettle were cut under an argon stream. Then, distillation purification was performed. Using this solvent, the metal halide compound was dissolved under an argon stream to a concentration of 0.
A 2 mol / liter raw material for CVD was prepared. At this time, the dissolution state of the metal halide compound in the solvent is also shown in Table 2. As a result, Comparative Production Examples 4 to 6 were insoluble.

[0027]

[Table 2]

[Evaluation Example] The CVD raw materials obtained in the above Production Examples 1 to 5 and Comparative Production Examples 1 to 3 were sealed and left to stand, and changes in the state of the solution were observed. The results are shown in Table 3. Incidentally, Comparative Production Examples 4 to 6 in which the metal halide compound was not dissolved in the solvent were not evaluated.

[0029]

[Table 3]

From the above evaluation examples, it was confirmed that the present invention can provide a stable raw material for CVD with a high concentration.

Example 1 (Production Example of Tantalum Nitride Thin Film) Using the CVD apparatus shown in FIG. 1, a tantalum nitride thin film was produced on a silicon wafer under the following conditions and raw materials. Regarding the manufactured thin film, the film composition was confirmed using X-ray diffraction. For tantalum nitride, the peaks of 2θ; 41.60, 60.41, and 72.22 are confirmed, and for tantalum carbide, 2θ; 40.46,
The peaks of 58.56 and 70.00 were confirmed.

(Raw Material) Raw material for CVD obtained in Production Example 3 (condition) Vaporization chamber temperature: 145 ° C., raw material flow rate: 0.15 ml / min,
Reaction gas: Ammonia gas, Reaction gas flow rate: 400sc
cm, reaction pressure: 600 to 1000 Pa, reaction time: 1
5 minutes, substrate temperature: 400 ° C. (result) X-ray diffraction: peak of tantalum nitride, no peak of tantalum carbide.

Comparative Example 1 (Production Example of Tantalum Nitride Thin Film) Using the CVD apparatus shown in FIG. 1, a tantalum nitride thin film was produced on a silicon wafer under the following conditions and raw materials. Regarding the manufactured thin film, the film composition was confirmed using X-ray diffraction in the same manner as in Example 1.

(Raw material) Raw material for CVD obtained in Comparative Production Example 1 (condition) Vaporization chamber temperature: 135 ° C., raw material flow rate: 0.15 ml / min,
Reaction gas: Ammonia gas, Reaction gas flow rate: 400sc
cm, reaction pressure: 600 to 1000 Pa, reaction time: 1
5 minutes, substrate temperature: 400 ° C. (result) X-ray diffraction: tantalum nitride peak, tantalum carbide peak.

In Comparative Example 1, the raw material flow rate decreased during the thin film production and could not be kept constant. Further, after the production, remarkable solid adhesion was observed on the vaporizer piping and the reaction film forming chamber. This is a phenomenon caused by the precipitation of tantalum pentachloride due to the large difference in volatilization temperature between acetonitrile and tantalum pentachloride. Further, the peak of tantalum carbide was observed because acetonitrile reacted with tantalum pentachloride together with ammonia to produce tantalum carbide.

From the comparison of Example 1 and Comparative Example 1 described above,
It was confirmed that the present invention can provide a method for producing a thin film by the CVD method, which is excellent in stability of raw material supply and composition controllability.

Example 2 (Production Example of Carbon-Tantalum Nitride Thin Film) CVD shown in FIG.
Using the apparatus, a tantalum carbonitride thin film was produced on a cemented carbide plate under the following conditions and raw materials. Regarding the manufactured thin film, the film composition was confirmed using X-ray diffraction in the same manner as in Example 1.

(Raw Material) Raw material for CVD obtained in Production Example 1 (condition) Vaporization chamber temperature: 140 ° C., raw material flow rate: 0.15 ml / min,
Reaction gas: none, reaction pressure: 600 to 1000 Pa, reaction time: 15 minutes, substrate temperature: 720 ° C. (result) X-ray diffraction: tantalum nitride peak, tantalum carbide peak.

[0039]

INDUSTRIAL APPLICABILITY The present invention uses an inexpensive metal halide compound and is excellent in the stability of supply of raw materials and the composition controllability.
A raw material for D and a method for producing a thin film using the same can be provided.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of a CVD apparatus used in the method for producing a thin film of the present invention.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Senji Wada             7-35 Higashiokyu, Arakawa-ku, Tokyo Asahiden             Chemical Industry Co., Ltd. F-term (reference) 4K030 AA11 BA17 BA36 BA38 LA22                 4M104 BB29 BB30 BB32 BB34 DD45

Claims (5)

[Claims] 1. A raw material for forming a metal nitride and / or metal carbide thin film on a substrate by chemical vapor deposition, which comprises a metal halide compound represented by the following general formula (I) and the following general formula (I): A chemical vapor deposition raw material containing a compound having a cyano group represented by II). [Chemical 1] 2. The chemical vapor deposition raw material according to claim 1, wherein in the general formula (I), M is tantalum. 3. The chemical vapor deposition raw material according to claim 1, wherein in the general formula (I), X is chlorine. 4. A method for producing a metal nitride and / or metal carbide thin film by a chemical vapor deposition method using the chemical vapor deposition raw material according to claim 1. 5. A method for producing a thin film of tantalum nitride and / or tantalum carbide by the chemical vapor deposition method using the chemical vapor deposition raw material according to claim 2.