Tetrakis(ethylmethylamino)hafnium synthesis method

Abstract

The invention relates to a tetrakis(ethylmethylamino)hafnium synthesis method, which comprises the following synthesis steps: (1) under an inert atmosphere, adding methylethylamine and an alkane solvent to a three-necked bottle, carrying out mechanical stirring, placing the reaction bottle into an environment with a temperature of -10 to -80 DEG C, adding a n-hexane solution of n-butyl lithium to the reaction bottle in a dropwise manner, and carrying out a stirring reaction after completing the addition; (2) adding hafnium tetrachloride to the reaction system, maintaining the temperature of the reaction system to not more than 60 DEG C, carrying out a stirring reaction on the reaction system under the protection of the inert gas after completing the addition; and (3) after completing the reaction, removing the reacting solvent under an atmospheric pressure, carrying out vacuum distillation after completely removing the solvent, and collecting the 110-115 DEG C / 4-5 mmHg fraction, wherein the fraction is the tetrakis(ethylmethylamino)hafnium compound. According to the present invention, the reaction adopts the simple and easily available materials such as methylethylamine, butyl lithium and hafnium tetrachloride as the raw materials, the operations are simple, and the cost is reduced.

Description

[0001] technical field [0002] The invention relates to a method for synthesizing a metal organic complex, specifically a method for synthesizing metal hafnium coordinated by an amine-based compound used for a high-k value precursor material. [0003] Background technique [0004] With the continuous development and progress of large-scale integrated circuits, the integration of integrated circuits has been continuously improved, which requires the size of the original device to be continuously reduced to meet its requirements. When the thickness of the gate dielectric is less than 2nm, the transconductance decreases as the thickness of the gate dielectric decreases, and the ultra-thin gate oxide will cause direct tunneling of electrons due to the thinning of the interface barrier with silicon. [0005] Currently, silicon dioxide is the commonly used dielectric despite its relatively low dielectric constant (k~4). Silicon dioxide also has a very good application on the ga...

AI Technical Summary

Problems solved by technology

The basic principles of these two methods are the same, and their common disadvantage is that they all need to add another auxiliary solvent

Toluene is used in the first method, which makes the reaction more toxic, and the reaction needs to be carried out under heating conditions, which increases the operational difficulty and cost of the reaction

In the second method, tetrahydrofuran is used as an auxiliary solvent, which increases the toxicity of the reaction, and it also makes it more difficult to filter and separate lithium chloride salt. At the same time, because of the addition of tetrahydrofuran, there is a certain coordination effect, which makes distillation purification The process of the target product requires higher temperature and lower vacuum, which further increases the cost of the reaction and makes the yield low

At the same time, the reaction takes several days to complete, which greatly reduces the reaction efficiency.

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