JP5732962B2 - Method for producing zirconium amide compound - Google Patents

Description

  The present invention relates to a method for producing a zirconium amide compound that can be used, for example, as a compound semiconductor material or a polymerization catalyst, particularly when a zirconium-containing thin film is formed.

  In recent years, with the miniaturization of semiconductor memories and devices represented by DRAMs, zirconium-containing thin films, which are high dielectric materials, have attracted attention in the field of capacitors. In addition, active research and development is being conducted for applications of electronic materials such as ferroelectric capacitors and insulating films.

  As a method for producing a zirconium-containing thin film, for example, a sputtering method or a sol-gel method has been reported. However, due to excellent thin film uniformity and composition control, and mass production, chemical vapor deposition (Chemical Vapor Deposition method; hereinafter referred to as CVD method) and atomic layer deposition (Atomic Layer deposition method; hereinafter referred to as ALD method) It can be said that the manufacturing method is now mainstream.

  Conventionally, as a method for producing a zirconium amide compound used as a raw material for a CVD method or an ALD method, for example, zirconium tetrachloride and ethylcyclopentadienyl sodium are reacted to form an intermediate (ethylcyclopentadienyl) trichloro. Zirconium is produced, and then this intermediate is reacted with dimethylamidolithium to produce (ethylcyclopentadienyl) tris (dimethylamido) zirconium (see, for example, Patent Document 1). Tetrakis (dimethylamido) ) A method for producing (cyclopentadienyl) tris (dimethylamido) zirconium by heating and reacting zirconium and cyclopentadiene in a solvent (for example, see Non-Patent Documents 1 and 2).

Special table 2010-506378

Journal of the Chemical Society (A), 1940 (1968) Journal of Molecular Cat. A: Chemical, 170, 127 (2001)

  In the method of Patent Document 1, ethylcyclopentadiene and a sodium source are reacted to produce ethylcyclopentadienyl sodium (raw material), and alkyllithium and dimethylamine are reacted to obtain dimethylamidolithium (raw material). Next, there is a problem that the target product must be manufactured using two raw materials and the yield of the target product is as low as 35%.

  On the other hand, in the production methods of Non-Patent Documents 1 and 2, after alkyllithium and dimethylamine are reacted to produce dimethylamidolithium, this is then reacted with zirconium tetrachloride to produce tetrakis (dimethylamido) zirconium. Furthermore, a multi-step reaction such as reacting cyclopentadiene has become essential. for that reason. There was a problem as an industrially suitable production method.

  An object of the present invention is to provide an industrially suitable method for producing a zirconium amide compound, in which a zirconium amide compound is produced with a high yield and a high selectivity using a zirconium halide as a starting material.

The subject of this invention is general formula (1).

(In the formula, X represents a halogen atom. The four Xs may be the same or different from each other.)
Zirconium halide represented by the general formula (2)

(In the formula, R ¹ and R ² represent a linear or branched alkyl group having 1 to 6 carbon atoms. Note that R ¹ and R ² may be bonded to each other to form a ring. )
And then mixed with a dialkylamine represented by the general formula (3)

(In the formula, L represents a cyclopentadienyl group which may be substituted with an alkyl group having 1 to 5 carbon atoms.)
A cyclopentadiene which may have a substituent represented by the formula (4) is reacted with an alkyl alkali metal.

(In the formula, R ^1, R ² and L are as defined above.)
It solves by the manufacturing method of the zirconium amide compound shown by these.

  The present invention can provide an efficient method for producing a zirconium amide compound that can be used, for example, when forming a compound semiconductor material or a polymerization catalyst, particularly a zirconium-containing thin film.

  The zirconium halide used in the reaction of the present invention is represented by the general formula (1). In the general formula (2), X represents a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, and the four Xs may be the same or different from each other. In addition, you may use a metal halide individually or in mixture of 2 or more types.

The amine compound used in the present invention is represented by the general formula (2). In the general formula (2), R ¹ and R ² may be the same or different and each represents a linear or branched alkyl group having 1 to 6 carbon atoms. For example, a methyl group, an ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, pentyl group and hexyl group. R ¹ and R ² may be bonded to each other to form a ring.

  Specific examples of these amine compounds include, for example, dimethylamine, ethyl (methyl) amine, isopropyl (methyl) amine, n-propyl (methyl) amine, diethylamine, ethyl (isopropyl) amine, ethyl (n-propyl) amine, Examples include di (isopropyl) amine, di (n-propyl) amine, isopropyl (n-propyl) amine, di (n-butyl) amine, dipentylamine, dihexylamine, pyrrolidine, piperidine, 1-methylpyrrolidine, and pyrrole. Are preferably dimethylamine, ethylmethylamine, isopropyl (methyl) amine, n-propyl (methyl) amine, diethylamine, ethyl (isopropyl) amine, ethyl (n-propyl) amine, pyrrolidine, 1-methylpyrrolidine, and more preferably Better Dimethylamine, ethyl methylamine, isopropyl (methyl) amine, diethylamine, is used. In addition, you may use these amine compounds individually or in mixture of 2 or more types.

  The use form of the amine compound in the present invention may be any form of gas, liquid or solid, or a state in which they coexist. For example, in the case of dimethylamine, it may be introduced into the reaction system as a gas or pressurized. Alternatively, it may be used as a liquid after cooling or in a normal state dissolved in an organic solvent. If it is a solid amine, it may be pulverized and used as a powder, it may be used after being heated and melted, or it may be used after being dissolved in a solvent.

  The amount of the dialkylamine used is preferably 20.0 to 3.0 mol, more preferably 10.0 to 4.0 mol, per 1 mol of zirconium halide.

  The cyclopentadiene (LH) which may have a substituent used in the present invention is represented by the general formula (3). In the general formula (3), L represents a cyclopentadienyl group which may be substituted with an alkyl group having 1 to 5 carbon atoms. Examples of the substituent include a methyl group, an ethyl group, and n. -An alkyl group having 1 to 5 carbon atoms such as propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group and pentyl group. One or a plurality of substituents may be used, and the substitution position is not particularly limited.

  Examples of the cyclopentadiene which may have these substituents include, for example, cyclopentadiene; methylcyclopentadiene, ethylcyclopentadiene, n-propylcyclopentadiene, isopropylcyclopentadiene, n-butylcyclopentadiene, t-butylcyclopentadiene, monoalkylcyclopentadiene such as sec-butylcyclopentadiene; dimethylcyclopentadiene, methylethylcyclopentadiene, diethylcyclopentadiene, di-n-propylcyclopentadiene, diisopropylcyclopentadiene, di-n-butylcyclopentadiene, disec-butylcyclopentadiene, Dialkylcyclopentadiene such as di-t-butylcyclopentadiene; trimethylcyclopentadiene, dimethyl (ethyl) silane Examples include trialkylcyclopentadiene such as clopentadiene, diethyl (methyl) cyclopentadiene, tri-t-butylcyclopentadiene; tetraalkylcyclopentadiene such as tetramethylcyclopentadiene; pentaalkylcyclopentadiene such as pentamethylcyclopentadiene. In addition, these cyclopentadiene includes various positional isomers.

  The cyclopentadiene which may have a substituent can be obtained, for example, by a method such as thermal decomposition (cracking) of the dimer or the like.

  The amount of the cyclopentadiene which may have a substituent is preferably 0.8 to 2.0 mol, more preferably 1.0 to 1.5 mol, per 1 mol of zirconium halide. .

  Examples of the alkyl alkali metal used in the present invention include n-butyl lithium, n-hexyl lithium, t-butyl lithium, methyl lithium, di-n-butyl magnesium, n-butyl (ethyl) magnesium, ethyl magnesium chloride, t-chloride. -Butylmagnesium, benzylmagnesium chloride and the like can be mentioned, preferably n-butyllithium, n-hexyllithium, t-butyllithium, methyllithium, more preferably n-butyllithium. In addition, you may use these alkyl alkali metals individually or in mixture of 2 or more types.

  The amount of the alkyl alkali metal used is preferably 3.0 to 5.0 mol, more preferably 3.5 to 4.5 mol, per 1 mol of zirconium halide.

  In the reaction of the present invention, the reaction is preferably carried out in a solvent, and the solvent used is not particularly limited as long as it does not inhibit the reaction. For example, n-pentane, n-hexane, n-heptane, n -Aliphatic hydrocarbons such as octane, isooctane, cyclohexane, methylcyclohexane and ethylcyclohexane; aromatic hydrocarbons such as benzene, toluene and xylene; and ethers such as diethyl ether, tetrahydrofuran and dimethoxyethane are preferred, Is n-hexane, n-heptane, n-octane, isooctane, cyclohexane, methylcyclohexane, ethylcyclohexane, toluene, xylene, more preferably n-hexane, n-heptane, cyclohexane, methylcyclohexane, ethylcyclohexane. Toluene, xylene are used. In addition, you may use these solvents individually or in mixture of 2 or more types.

  The reaction of the present invention is carried out, for example, by mixing zirconium halide and dialkylamine, and then adding cyclopentadiene and alkyl alkali metal which may have a substituent, and reacting with stirring. .

More specifically, that is, it is performed by any of the following methods.
Method (1): After mixing a zirconium halide and a dialkylamine, a solution in which a cyclopentadiene which may have a substituent and an alkyl alkali metal is mixed is added and reacted.

(In the formula, X, R ^1, R ² and L are as defined above.)

Method (2): After mixing the zirconium halide and the dialkylamine, the alkyl alkali metal and the optionally substituted cyclopentadiene are then added and reacted in this order.

(In the formula, X, R ^1, R ² and L are as defined above.)

Method (3): After mixing the zirconium halide and the dialkylamine, the cyclopentadiene which may have a substituent and the alkyl alkali metal are added and reacted in this order.

(In the formula, X, R ^1, R ² and L are as defined above.)

  Among the above methods (1) to (3), the method (2) and the method (3) are preferably employed, and the method (3) is more preferably employed. By adopting these methods, L can be introduced smoothly.

  The reaction temperature during the reaction is preferably −200 to 200 ° C., more preferably −100 to 150 ° C., and the reaction pressure is not particularly limited.

  The method for producing a zirconium amide compound obtained by the reaction of the present invention is isolated and purified by a general method such as neutralization, extraction, filtration, concentration, distillation, sublimation, recrystallization, column chromatography after the reaction is completed. Is done.

  In addition, when the zirconium amide compound of the present invention is (cyclopentadienyl) tris (dimethylamide) zirconium, the synthesis is performed by the method (3), and the general formula (5)

(Wherein R ¹ and R ^{2 have} the same meanings as described above.)
The content of tetrakis (dialkylamido) zirconium represented by the formula is less than 1%, and the general formula (6)

(In the formula, R ^1, R ² and L are as defined above.)
The content of bis (cyclopentadienyl) bis (dialkylamido) zirconium represented by the formula is less than 1%.

  Next, the present invention will be specifically described with reference to examples, but the scope of the present invention is not limited thereto.

Example 1 (Method (3); Synthesis of (cyclopentadienyl) tris (dimethylamido) zirconium)

In a 200-ml flask equipped with a stirrer and a thermometer, 6.01 g (25.79 mmol) of zirconium tetrachloride and 60 ml of toluene were mixed in an argon atmosphere, and then the mixture was cooled. Next, 10.51 g (233.14 mmol) of liquid dimethylamine was slowly added dropwise so that the liquid temperature did not exceed -10 ° C. Thereafter, 66 ml (108.90 mmol) of a 1.65 mol / L n-butyllithium hexane solution was slowly added dropwise to the reaction mixture so that the liquid temperature did not exceed -10 ° C. Further, 2.21 g (33.43 mmol) of cyclopentadiene was slowly added dropwise and reacted for 1 hour.
After completion of the reaction, the reaction solution was filtered and then the filtrate was concentrated. The obtained concentrate was distilled under reduced pressure (90 ° C., 16 Pa) to obtain 5.35 g of (cyclopentadienyl) tris (dimethylamido) zirconium as a pale yellow liquid (isolated yield; 71.7%). .

  In the obtained (cyclopentadienyl) tris (dimethylamide) zirconium, the content of tetrakis (dialkylamido) zirconium is less than 1%, and bis (cyclopentadienyl) bis (dialkylamido) zirconium. The content of was less than 1%.

Example 2 (Method (3); Synthesis of (cyclopentadienyl) tris (dimethylamido) zirconium)

In a 3 L flask equipped with a stirrer and a thermometer, 92.48 g (0.397 mol) of zirconium tetrachloride and 1 L of toluene were mixed in an argon atmosphere, and then the mixture was cooled. Next, 127.88 g (2.837 mol) of gaseous dimethylamine was gently blown so that the liquid temperature did not exceed 10 ° C. Thereafter, 1.03 L (1.663 mol) of a 1.63 mol / L n-butyllithium hexane solution was slowly added dropwise to the reaction mixture so that the liquid temperature did not exceed 10 ° C. Furthermore, 31.10 g (0.471 mol) of cyclopentadiene was added dropwise and reacted for 2 hours.
After completion of the reaction, the reaction solution was filtered and then the filtrate was concentrated. The obtained concentrate was distilled under reduced pressure (90 to 100 ° C., 20 Pa) to obtain 89.89 g of (cyclopentadienyl) tris (dimethylamido) zirconium as a pale yellow liquid (isolation yield: 73.9). %).

  In the obtained (cyclopentadienyl) tris (dimethylamide) zirconium, the content of tetrakis (dialkylamido) zirconium is less than 1%, and bis (cyclopentadienyl) bis (dialkylamido) zirconium. The content of was less than 1%.

Comparative Example 2 (Method (2); Synthesis of (cyclopentadienyl) tris (dimethylamido) zirconium)

In a 200-ml flask equipped with a stirrer and a thermometer, 6.03 g (25.88 mmol) of zirconium tetrachloride and 60 ml of toluene were mixed in an argon atmosphere, and then the mixture was cooled. Next, 8.30 g (184.12 mmol) of liquid dimethylamine was slowly added dropwise so that the liquid temperature did not exceed −10 ° C. Thereafter, 2.21 g (33.43 mmol) of cyclopentadiene was gently added dropwise to the reaction mixture. Further, 64 ml (103.68 mmol) of a 1.62 mol / L n-butyllithium hexane solution was slowly added dropwise so that the liquid temperature did not exceed −10 ° C. and reacted for 1 hour.
After completion of the reaction, the reaction solution was filtered and then the filtrate was concentrated. The obtained concentrate was distilled under reduced pressure (60 to 130 ° C., 24 Pa), and (cyclopentadienyl) tris (dimethylamino) zirconium was obtained as a pale yellow liquid in a yield of 20% (analysis by ¹ H-NMR). value).
In addition, 15% of tetrakis (dimethylamido) zirconium was produced as a white solid, and 5% of bis (cyclopentadienyl) bis (dimethylamido) zirconium was produced as a yellow solid (analytical value by ¹ H-NMR).

Comparative Example 1 (Synthesis of (cyclopentadienyl) tris (dimethylamido) zirconium)

After mixing 6.80 g (29.18 mmol) of zirconium tetrachloride and 60 ml of toluene in an argon atmosphere in a 200 ml flask equipped with a stirrer and a thermometer, the reaction mixture was cooled. Next, 2.47 g (37.37 mmol) of cyclopentadiene was slowly added dropwise so that the liquid temperature did not exceed -10 ° C. Thereafter, 11.94 g (264.86 mmol) of liquid dimethylamine was slowly added dropwise to the reaction mixture so that the liquid temperature did not exceed -10 ° C. Furthermore, 74 ml (119.88 mmol) of a 1.62 mol / L n-butyllithium hexane solution was dropped slowly so that the liquid temperature did not exceed −10 ° C., and reacted for 1 hour.
After completion of the reaction, the reaction solution was filtered and then the filtrate was concentrated. When the obtained concentrate was distilled under reduced pressure (60 to 90 ° C., 16 Pa), only tetrakis (dimethylamido) zirconium was obtained as a white solid (3.02 g), and the desired (cyclopentadienyl) tris (dimethyl) was obtained. Amido) zirconium was not produced.

  The present invention can provide a zirconium amide compound zirconium that can be used, for example, when forming a compound semiconductor material or a polymerization catalyst, particularly a zirconium-containing thin film.

Claims (1)

General formula (1)
(In the formula, X represents a halogen atom. The four Xs may be the same or different from each other.)
Zirconium halide represented by the general formula (2)
(In the formula, R1 and R2 represent a linear or branched alkyl group having 1 to 6 carbon atoms.
R1 and R2 may be bonded to each other to form a ring. )
And then mixed with a dialkylamine represented by the general formula (3)
(In the formula, L represents a cyclopentadienyl group which may be substituted with an alkyl group having 1 to 5 carbon atoms.)
A cyclopentadiene which may have a substituent represented by and an alkyl alkali metal ,
Cyclopentadiene and alkyl which may have the above-mentioned substituent continuously after the reaction of the zirconium halide represented by the general formula (1) and the dialkylamine represented by the general formula (2). React with alkali metals,
When reacting cyclopentadiene which may have a substituent and alkylalkali metal, the reaction is performed by adding alkylalkali metal and cyclopentadiene which may have a substituent in this order. Formula (4)
(Wherein R1, R2, and L are as defined above.)
The manufacturing method of the zirconium amide compound shown by these.